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March 4, 2021
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https://www.sciencedaily.com/releases/2021/03/210304112407.htm
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Researchers discover how to control zinc in plants: Could help the world's malnourished
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Over 2 billion people worldwide are malnourished due to zinc deficiency. Led by the University of Copenhagen, an international team of researchers has discovered how plants sense zinc and use this knowledge to enhance plant zinc uptake, leading to an increase in seed zinc content by 50 percent. The new knowledge might one day be applied towards the cultivation of more nutritious crops.
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A deficiency of zinc and other essential dietary nutrients is one of the greatest causes of malnutrition worldwide. More than two billion people are estimated to suffer from zinc deficiency, a problem that can lead to impaired immune systems, mental disorders and stunting. Among other things, malnutrition can be caused by infertile agricultural land, which affects the nutritional content of staple crops such as rice, wheat and maize.But imagine that it was possible to flip a switch in crops, at the seed stage, that prompted them to turbocharge their intake of zinc, iron or other nutrients, and cause them to absorb more nutrients than they would otherwise. Researchers at the University of Copenhagen's Department of Plant and Environmental Sciences have done just that using the thale cress plant (Arabidopsis thaliana)."For the first time ever, we have demonstrated that, by using a molecular 'switch' in the plant, we can cause the plant to absorb more zinc than it would otherwise, without apparent negative impact on the plant," states the study's lead author, Associate Professor Ana Assunção of the University of Copenhagen's Department of Plant and Environmental Sciences.Zinc benefits humans by helping to maintain a wide array of chemical processes and proteins running within our bodies. Should these processes cease to function properly, we become prone to illness. For plants, the absence of zinc primarily impacts growth, which is adversely affected in the absence of zinc.Researchers have long attempted to understand how plants increase and decrease their zinc uptake. Ana Assunção and her colleagues have become the first to identify two specific proteins from thale cress that act as zinc sensors and determine the plant's ability to absorb and transport zinc throughout plant tissue.By changing the properties of these sensors, or molecular "switch," that control a tightly connected network of zinc transporters, the researchers succeeded in getting them to absorb more zinc."Simply put, by making a small change in the sensor, we've led the plant to believe that it was in a permanent state of zinc deficiency. This kept the plant's zinc uptake machinery swiched-on and resulted in an increase of zinc content in the seeds by as much as 50 percent compared to a normal plant," explains Grmay Lilay, the study's first author, Postdoc at Assunção's Lab .The researchers have demonstrated that it is possible to increase zinc-absorption in their experimental plant, but the next step is to reproduce the results in real crops. And the researchers are already well on the way to doing so."We're currently working to recreate our results in bean, rice and also tomato plants. Should we succeed, we'll realize some interesting opportunities to develop more nutritious and biofortified crops. Biofortification is a sustainable solution to improve micronutrient content in human diet," says Associate Professor Assuncao.In the long term, the researchers' results could be applied by using CRISPR gene editing or by selecting naturally occurring crop varieties with a particularly good ability to absorb nutrients like zinc. "The availability of enormous genomic resources will assist our efforts in finding crop varieties that are likely to display higher zinc accumulation, " concludes Grmay Lilay.The result was achieved in collaboration with Wageningen University and the University of Porto and has just been published in the renowned journal * Zinc is a key structural and catalytic component of a large number of proteins. For all proteins to function properly, an optimal zinc supply needs to be maintained, avoiding deficiency or toxicity.* In humans, the risk of zinc deficiency alone can lead to different degrees of growth retardation, immune dysfunction, and cognitive impairment.
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Agriculture & Food
| 2,021 |
March 2, 2021
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https://www.sciencedaily.com/releases/2021/03/210302150045.htm
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Ultrasonic cleaning of salad could reduce instances of food poisoning
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A new study has shown that gentle streams of water carrying sound and microscopic air bubbles can clean bacteria from salad leaves more effectively than current washing methods used by suppliers and consumers. As well as reducing food poisoning, the findings could reduce food waste and have implications for the growing threat of anti-microbial resistance.
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Salad and leafy green vegetables may be contaminated with harmful bacteria during growing, harvesting, preparation and retail leading to outbreaks of food poisoning which may be fatal in vulnerable groups.Because there is no cooking process to reduce the microbial load in fresh salads, washing is vital by the supplier and the consumer.Washing with soap, detergent bleach or other disinfectants is not recommended and the crevices in the leaf surface means washing with plain water may leave an infectious dose on the leaf. Even if chemicals are used, they may not penetrate the crevices.In this new study, published in the journal Professor Timothy Leighton of the University of Southampton, who invented the technology and led this research, explains: "Our streams of water carry microscopic bubbles and acoustic waves down to the leaf. There the sound field sets up echoes at the surface of the leaves, and within the leaf crevices, that attract the bubbles towards the leaf and into the crevices. The sound field also causes the walls of the bubbles to ripple very quickly, turning each bubble into a microscopic 'scrubbing' machine. The rippling bubble wall causes strong currents to move in the water around the bubble, and sweep the microbes off the leaf. The bacteria, biofilms, and the bubbles themselves, are then rinsed off the leaf, leaving it clean and free of residues."The results showed that the microbial load on samples cleaned with the acoustic streams for two minutes was significantly lower six days after cleaning than on those treated without the added sound and bubbles. The acoustic cleaning also caused no further damage to the leaves and demonstrated the potential to extend food shelf life, which has important economic and sustainability implications.Improving how food providers clean fresh produce could have a major role to play in combating the threat of anti-microbial resistance. In 2018 and 2019, there were fatal outbreaks of different strains of E. coli on romaine lettuce in the USA and Canada and samples from humans infected showed strains that are resistant to antibiotics.University of Southampton PhD student Weng Yee (Beverly) Chong, who was part of the research team added: "I am very grateful to Vitacress and EPSRC for funding my PhD. I came from an engineering background, and took Professor Leighton's classes, but he told me that I could be a trans-disciplinary PhD student, and become a microbiologist whilst increasingmy engineering skills. I am also very grateful to Sloan Water Technology Ltd.: They opened up their laboratories for use by students like me, so that I can keep working on my experiments. It is an exciting environment to work in because they are doing so much inventive work to combat the pandemic and infections as a whole."Previously as part of her PhD Beverly has studied how the technology could reduce the infection risk to horses and other livestock through hay cleaning.The work was sponsored by Vitacress, whose Group Technical Director Helen Brierley said: "Ensuring food safety for our products is an essential requirement. At Vitacress, we wash our produce in natural spring water, and this type of ground-breaking new technology helps to enhance our process whilst ensuring our commitment to protect the environment is maintained. We are always interested in new developments and are excited to see the results of this research."
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Agriculture & Food
| 2,021 |
March 2, 2021
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https://www.sciencedaily.com/releases/2021/03/210302075407.htm
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Meeting the meat needs of the future
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Humans are largely omnivores, and meat in various forms has always featured in the diet of most cultures. However, with the increasing population and pressure on the environment, traditional methods of meeting this fundamental food requirement are likely to fall short. Now, researchers at the University of Tokyo report innovative biofabrication of bovine muscle tissue in the laboratory that may help meet escalating future demands for dietary meat.
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With global urbanization, the economics of animal husbandry are becoming unsustainable. From an environmental viewpoint, the land and water costs of modern mega-scale livestock farming are untenable, as are the greenhouse gas emissions and the overall toll on the planet. Additionally, ethical concerns against inhuman exploitation of lower species for food are increasingly being voiced.To address future requirements, tissue engineering of cultured meat is under development at several centers worldwide. However, most biosynthetic meat products are amorphous or granular-like minced meat, lacking the grain and texture of real animal flesh. Mai Furuhashi, lead author, explains their novel process. "Using techniques developed for regenerative medicine, we succeeded in culturing millimeter-sized chunks of meat wherein alignment of the myotubes help mimic the texture and mouthfeel of steak. For this, myoblasts drawn from commercial beef were cultured in hydrogel modules that could be stacked allowing fusion into larger chunks. We determined the optimal scaffolding and electrical stimulation to promote contractility and anatomical alignment of the muscle tissue to best simulate steak meat."Lead author, Yuya Morimoto, describes the synthesized product. "Our morphological, functional and food feature analyses showed that the cultured muscle tissue holds promise as a credible steak substitute. Breaking force measurements showed that toughness approached that of natural beef over time. Significantly, microbial contamination was undetectable; this has implications for cleanliness, consumer acceptability and shelf-life.""Our method paves the way for further development of larger portions of realistic cultured meat that can supplement or replace animal sources," claims Shoji Takeuchi, senior and corresponding author. "However, there is a long way to go before lab-grown meat is indistinguishable from the real thing and hurdles concerning consumer acceptance and cultural sensibilities are overcome. Nevertheless, this innovation promises to be a green and ethical alternative to animal slaughter in meeting our need for dietary meat."
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Agriculture & Food
| 2,021 |
March 2, 2021
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https://www.sciencedaily.com/releases/2021/03/210302094108.htm
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Detective work inside plant cells finds a key piece of the C4 photosynthesis puzzle
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An impressive body of evidence published this week reveals the answer to a mystery that has puzzled plant scientists for more than 30 years: the role of the molecule suberin in the leaves of some of our most productive crops. This discovery could be the key to engineering better crops and ensuring future food security.
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Highly productive crops such as sugarcane, sorghum and maize belong to the type of plants that use the more efficient C4 photosynthetic pathway to transform water, sunlight and carbon dioxide (COScientists have known for a long time that one of key factors that makes C4 photosynthesis more efficient is that they have the capacity to enclose CO"Our research provides several pieces of evidence about the responsibility of suberin on making the leaf cells of C4 plants, gas tight. Suberin forms a layer that keeps COThis discovery is the result of many years of work, a bit of serendipity and access to modern techniques that were not available until recently, including faster and cheaper genome mapping, high throughput phenotyping, electron microscopy and gas exchange measures."We have known for a long time that suberin is in the bundle sheath cells of the C4 plants leaves. However, we didn't have the experimental evidence to prove its essential role for C4 photosynthesis. Now, for the first time, we have been able to see clearly under the microscope, the anatomical differences between plants with and without suberin. The key element in this discovery is that we found a mutant population of green foxtail millet (Setaria viridis) that didn't have the gene that produces suberin," says CoETP's Deputy Director Professor Susanne von Caemmerer, one of the co-authors of this study.This elusive mutant population was generated in the International Rice Research Institute (IRRI) by screening hundreds of plants under low CO"Using high throughput screening, we identified only three mutants with impaired photosynthetic capacity. We sent the seeds to ANU in Canberra and they grew and analysed them using the electron microscope and gas exchange techniques. To our surprise, one of these mutants was the one that lacked suberin, says Dr Rob Coe, who was in charge of the screening process at IRRI.Centre Director and co-author of the paper Bob Furbank says that "this is a very exciting discovery, one of the last mechanistic pieces of the C4 photosynthesis puzzle, as Hal Hatch, the discoverer of the C4 pathway noted some time ago.""It shows that science discoveries can take a long time to be solved and that the recipe for eureka moments like this are the collaborative work of several experts combined with modern technologies, plus a pinch of serendipity. It seems that all the stars were aligned this time for us, but it was certainly a hard nut to crack," he says.Dr Danila says that the team's next steps involve applying their discovery and new developed methodologies to projects like the C4 rice project that aims to convert rice (a C3 photosynthesis crop) into the more productive C4 path."We will also focus on another unsolved mystery: the case of a group of grasses which use C4 photosynthesis but don't have suberin," she says.This research has been funded by the ARC Centre of Excellence for Translational Photosynthesis, which aims to improve the process of photosynthesis to increase the production of major food crops such as sorghum, wheat and rice.The research started as part of the C4 Rice Project consortium, which comprises the Academia Sinica, Australian National University, Max Planck Institute of Molecular Plant Physiology, Leibniz Institute of Biochemistry, University of Cambridge, University of Oxford and Washington State University and is funded by a grant from the Bill & Melinda Gates Foundation to the University of Oxford.
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Agriculture & Food
| 2,021 |
March 1, 2021
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https://www.sciencedaily.com/releases/2021/03/210301211622.htm
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Greenhouse gas emissions associated with dietary guidelines vary between countries
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Greenhouse gas emissions associated with national dietary guidelines advocating a healthy diet vary greatly between countries, with US guidelines having the largest carbon footprint and India having the smallest, according to a study involving seven countries published in the open access
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Diego Rose, the corresponding author said: "Many countries provide recommendations about foods that people should eat for a healthy diet and previous simulations have shown that if the public were to eat according to their government's recommendations, their diets would be both healthier and have a lower carbon footprint. However, for the US the opposite has been shown; greenhouse gas emissions were simulated to go up, if people followed dietary guidelines. This anomaly prompted us to investigate how dietary guidelines vary between countries and the consequent implications for greenhouse gas emissions."To investigate differences in greenhouse gas emissions associated with different dietary guidelines, a team of researchers at Tulane University compared the dietary guidelines and food consumption patterns of seven countries: Germany, India, the Netherlands, Oman, Thailand, Uruguay, and the United States.The authors found that the carbon footprint of India's dietary guidelines was comparatively low, with the recommended diet associated with the equivalent of 0.86 kg COThe authors also found that the principal difference between the dietary guidelines of the various countries was the wide range of daily recommended amounts for each food group, particularly protein and dairy foods. Daily recommended amounts of dairy foods ranged from 118ml per day for Oman to 710ml per day for the US. The greenhouse gas emissions associated with these two recommendations were equivalent to 0.17 and 1.10 kg COGuidelines also varied in terms of which foods were included in each food group. Protein food recommendations in Germany and Uruguay only included animal proteins, the US and Thailand recommended a full spectrum of plant and animal protein foods, whereas India recommended just plant proteins. The US vegetarian guideline recommended plant proteins, as well as dairy and eggs.Brittany Kovacs, the lead author said: "As there is great variation in the global warming impacts of these individual foods, which foods people consume and how much of them has an impact on the carbon footprint of dietary guidelines. For example, consumption of beef, mutton, and lamb in Uruguay accounts for 31% of protein foods, whereas in Germany it is only 16%. Thus, our calculated greenhouse gas emissions for Uruguay's protein food recommendation is 53% higher than Germany's, despite the fact that both countries' quantity recommendations for protein foods as a food group are about the same."Diego Rose added: "The US Vegetarian guideline is almost identical in recommendations to the main US guideline, except for the protein group -- which recommends legumes, soy, nuts, and seeds, as well as eggs -- resulting in an overall carbon footprint that is less than half."The authors caution that the study only considers a single environmental impact of diets, greenhouse gas emissions. Other environmental impacts, such as land and water use, should be considered when evaluating the overall impact of a diet. The study is restricted to the daily quantitative recommendations of seven countries' dietary guidelines, which may limit its generalizability to other countries.Brittany Kovacs said: "These findings hold insights for future development of dietary guidelines and highlight the importance of including sustainability considerations, such as reductions of protein food and dairy recommendations and/or the inclusion of more plant-based substitutions for animal-based products. By including more sustainable, yet still health-based, considerations into dietary recommendations, it is possible to influence the environmental impacts of the larger food and agriculture sector in various countries and worldwide.
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Agriculture & Food
| 2,021 |
March 1, 2021
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https://www.sciencedaily.com/releases/2021/03/210301151547.htm
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Optimally promoting biodiversity in agricultural landscapes
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Due to modern agriculture, biodiversity across many species groups is in decline. Over the last three decades, attempts have been made to counteract this with agri-environmental schemes at various levels -- from the national federal state to EU-wide programmes. Not only out of appreciation of nature, but also because many species fulfil important functions for agriculture itself: some pollinate crops, others regulate pest populations.
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One of the measures promoted in the schemes is the creation of flowering fields. "However, it is currently not conclusively known whether and to what extent these habitats achieve the desired effect on biodiversity," says Professor Ingolf Steffan-Dewenter. In order to provide more clarity, the head of the Chair for Animal Ecology and Tropical Biology at Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany, launched a large-scale field study in 2016. The results have now been published in the scientific journal The biologists investigated the species composition of different types of flowering fields in agricultural landscapes in northern Lower Franconia. As a benchmark, they used the semi-natural calcareous grasslands that can be found in this region. These usually protected flowering habitats are known for their high species diversity."Our approach differs from previous scientific studies in this field in some essential respects," explains Fabian Bötzl, the lead author of the Würzburg study. First, there is the extent of the species groups considered: A total of twelve taxonomic groups were studied -- from vascular plants to cicadas, bees, flies, butterflies and beetles to birds. In three years of data collection in the field and about another year of laboratory analyses, the researchers identified almost 55,000 specimens that could be assigned to 3187 taxa.Secondly, they included the temporal continuity of the diverse flowering fields. "This means that we -- unlike many previous studies -- took into account the respective age of the flowering fields and their history of use," explains JMU professor Jochen Krauss, co-author of the study.The results underpin that diversity increases in most taxonomic groups with the temporal continuity of the habitats. For example, there are only five to six species of grasshoppers on newly established flowering fields in the first year, which then increase over time to the approximately 15 species of the calcareous grasslands used as a reference.As a consequence, should -- in terms of species conservation -- the rule be 'the older the better'? "It is not that simple, as with flowering fields getting older, the composition and the respective number of species also change," Bötzl explains. "For some species, such as ground beetles, which play an important role in pest control in adjacent agricultural areas, young habitats are more advantageous. Their species number decreases over time."Another result of the study: the size of the flowering fields and their surrounding landscape -- whether rather monotonous or diverse -- have only minor effects on the development of species diversity.In addition to the scientific community, the planning authorities responsible for agri-environmental programmes can also be potential addressees of the Würzburg research results. The following messages can be derived for them: There is no ideal type of flowering field that supports all species equally well. For the aim of protecting as many animal and plant species as possible, well-distributed flowering fields of different ages are recommended in the agricultural landscape.
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Agriculture & Food
| 2,021 |
March 1, 2021
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https://www.sciencedaily.com/releases/2021/03/210301133840.htm
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Scientists describe 'hidden biodiversity crisis' as variation within species is lost
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The rapid loss of variation within species is a hidden biodiversity crisis, according to the authors of a new study looking at how this variation supports essential ecological functions and the benefits nature provides for people.
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Published March 1 in "Biodiversity means more than the number of species, and when we focus on species-level extinctions we are missing part of the story," said corresponding author Eric Palkovacs, professor of ecology and evolutionary biology at UC Santa Cruz. "Intraspecific variation is a neglected aspect of biodiversity, but it has value for people, and we need to start recognizing that and protecting this form of biodiversity."An earlier study led by first author Simone Des Roches, a postdoctoral researcher at UC Santa Cruz now at the University of Washington, showed that the loss of variation within species can have serious ecological consequences. This got Des Roches and Palkovacs thinking about the broader implications of their findings for the values and services nature provides to people, from forest materials and clean water to commercial fisheries and medicines derived from natural products.For the new study, they surveyed the scientific literature for studies showing how intraspecific variation supports ecosystem services and other aspects of nature's contributions to people. They found well documented connections across a wide variety of species, including fish and commercial fisheries, insects and crop pollination, woody plants and forestry products, many different crops and their wild ancestors, and more."There is a whole suite of documented cases, including several examples of what happens when we lose intraspecific variation," Palkovacs said. "One of the best examples is commercial fisheries, where diverse fish stocks help to stabilize the overall population."Subpopulations of salmon, for example, are locally adapted to the conditions of different watersheds, allowing the overall population to remain stable even as environmental fluctuations cause declines in some subpopulations and increases in others. These "portfolio effects" in salmon are undermined by dams, which block subpopulations from critical spawning habitat, and by hatchery production, which can reduce genetic variation. The loss of intraspecific variation in salmon can lead to boom-bust population cycles that are detrimental to the long-term value of the fishery.Des Roches noted that people have long depended on variation within domesticated and agriculturally important species. "Our coevolutionary history with hundreds of domesticated species is characterized by our continued selection for unusual and beneficial variants within species," she said. "We've often taken this too far and have thus lost critical genetic diversity in domesticated species. We depend on outbreeding with more genetically variable wild type or ancestral populations (when they exist) to restore this diversity."Plants with medicinal value provide other well documented examples of the value of intraspecific variation, Palkovacs said. "Different varieties of the same plant species may have different compounds with different medicinal properties, such as different antimalarial drugs that depend on the genetic diversity of the plants they are derived from."The authors emphasized the importance of collaborating with local and indigenous groups who have deep knowledge of the relationships between intraspecific variation and the natural products and services they use. "We need to take advantage of the local knowledge systems to inform our understanding of these connections," Palkovacs said.He noted that Western science has focused overwhelmingly on species-level extinctions, and only the most well-studied groups of organisms have been characterized from the standpoint of intraspecific variation. Of all the species evaluated by the International Union for Conservation of Nature (IUCN), for example, only about 1 percent have been evaluated below the species level, and many of those show precipitous declines in diversity."There is strong evidence that the loss of intraspecific variation may be a very widespread problem, but we don't even know what is being lost," Palkovacs said.There are practical steps that can be taken now, he said, to better document this variation, preserve biodiversity, and protect its contributions to the wellbeing of people. New genomic tools, for example, are available to quickly and systematically characterize the variation within species. This intraspecific variation can be directly incorporated into biodiversity assessments, such as those done by the IUCN and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).Addressing this aspect of biodiversity should be a major goal of global conservation efforts, the authors said. "The available evidence strongly suggests that the benefits of studying and conserving intraspecific variation will far outweigh the costs," Palkovacs said.He noted that variation within species is the raw material of adaptive evolution. In a rapidly changing world, this variation is critically important to enable species to adapt to the conditions of an unpredictable future.
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Agriculture & Food
| 2,021 |
March 1, 2021
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https://www.sciencedaily.com/releases/2021/03/210301112323.htm
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Identified: A mechanism that protects plant fertility from stress
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As Temperatures rise due to global warming the need to protect plants from stressful conditions has increased, as stress can cause a loss in yield and cause further impact economically. A consortium led by the University of Warwick have successfully identified two proteins that protect crops from stress, which is key in safeguarding food production.
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Plant fertility is dramatically affected by spikes in temperature, directly resulting in yield reduction and economic loss. Understanding the molecular mechanisms that underpin plant fertility under environmental constraints is critical to safeguarding food production.In the paper, 'A transposon surveillance mechanism that safeguards plant male fertility during stress', published in the journal By subjecting maize plants with non-functional AGO proteins to different growth conditions, researchers discovered that a 5?C increase in ambient temperature dramatically decreased male fertility.Using a multidisciplinary approach, the team found that higher temperatures activated small pieces of ribonucleic acid (or small RNAs) in wild-type plants, which bind to these AGO proteins to control the activity of stress-activated jumping genes -- pieces of DNA that can copy themselves into different parts of the genome. Therefore, these AGO proteins control the activity of jumping-genes, thereby protect plant fertility.Professor Jose Gutierrez-Marcos, from the School of Life Sciences at the University of Warwick explains:"We have essentially found that when plants are stressed by high temperatures they activate an RNA-guided surveillance mechanism in the form of small RNAs and Argonaute proteins, in reproductive cells which are critical to sustain male fertility and ultimately plant survival."Understanding the molecular mechanism implicated in safeguarding plant fertility is critical to safeguard future crop production under unpredictable and stressful climatic conditions."Dr Charo del Genio, from the School of Computing, Electronics and Mathematics at Coventry University adds:"Modelling the structure of the Argonaute proteins and simulating them at the level of the single atoms revealed how they change their electric charge when subject to thermal stress, initiating the process that brings the jumping genes back under control."
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Agriculture & Food
| 2,021 |
February 26, 2021
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https://www.sciencedaily.com/releases/2021/02/210226121245.htm
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Pesticide imidacloprid threatens future for key pollinator
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An insecticide used to control pest infestations on squash and pumpkins significantly hinders the reproduction of ground-nesting bees -- valuable pollinators for many food crops, a new University of Guelph study has revealed.
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This first-ever study of pesticide impacts on a ground-nesting bee in a real-world context found female hoary squash bees exposed to imidacloprid dug 85 per cent fewer nests, collected less pollen from crop flowers and produced 89 per cent fewer offspring than unexposed bees."Because they're not making nests and not collecting pollen, they cannot raise offspring," said Dr. Susan Willis Chan, a post-doc in the School of Environmental Sciences (SES), who conducted the study with Dr. Nigel Raine, holder of the Rebanks Family Chair in Pollinator Conservation in SES. "That means imidacloprid-exposed populations are going to decline."Neonicotinoids (or neonics) are neurotoxic insecticides that kill insects by attacking their nervous systems, affecting learning, foraging and navigation in many kinds of bees. Farmers use the neonic imidacloprid to control cucumber beetles, the most damaging crop pest for squash and pumpkins.Many species of ground-nesting bees, including the hoary squash bee, are responsible for pollination of numerous fruits, vegetables and oilseed crops in North America, said Chan."Solitary ground-nesting bees make up about 70 per cent of bee species. It's a really important ecological group and is also really important in crop pollination," she said.However, these ground-dwellers are often overlooked when it comes to evaluating the impacts of pesticides on pollinators, she added.Published recently in To mimic field conditions, Chan held the bees in mesh-covered enclosures that still allowed exposure to sun and rain and other environmental factors. She applied pesticides in ways that mirror actual use in farmers' fields.Chan tested three insecticide treatments: the neonic imidacloprid applied to soil at planting time; the neonic thiamethoxam applied as a seed treatment; and an anthranilic diamide (an emerging non-neonic insecticide) sprayed onto growing plants. A fourth group without insecticides served as a control.Studying the bees for three years allowed the team to show longer-term impacts of imidacloprid exposure on reduced nest-building, foraging and offspring reduction.Bees visiting squash plants treated with anthranilic diamide collected significantly less pollen than those in the control group but had no fewer nests or offspring. Chan saw no measurable effects from the thiamethoxam seed treatment on pollen harvesting, nest construction or offspring production."Farmers and regulators need to look at alternatives to applying imidacloprid to soil for controlling pests on squash and pumpkins," she said."My recommendation to pumpkin and squash farmers is to stay away from imidacloprid applied to soil to keep their squash bees healthy."Raine said it's likely other solitary, ground-nesting species are also being affected.Noting that other ground-nesters live in farm fields, he said, "The sort of impacts from soil-applied pesticide exposure we've seen in this study could affect many other species of wild bees."He said current regulatory assessments for insect pollinators fail to consider risks associated with soil pesticide residues. "Our results highlight why this should be changed to better characterize risk for the many bee species that spend a large proportion of their life in soil."Given the importance of pollinating insects to crop production, Chan said, "Farmers need to protect their crops from pests, but they also absolutely need to protect pollinators from the unintended effects of pesticides."Referring to imidacloprid, she said, "The data on this particular product are so clear that there's really no question about what has to happen. We have to find something else."This research was funded by the Ontario Ministry of Agriculture, Food and Rural Affairs; the Ontario Ministry of the Environment, Conservation and Parks; the Ontario Fresh Vegetable Growers' Association; the Natural Sciences and Engineering Research Council; and the Weston Family Foundation.
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Agriculture & Food
| 2,021 |
February 26, 2021
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https://www.sciencedaily.com/releases/2021/02/210226121242.htm
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Maternal instincts lead to social life of bees
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The maternal care of offspring is one of the behavioural drivers that has led some bee species to have an ever-expanding social life over the history of evolution, new research out of York University has found.
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By virtue of being in a social group, the genome itself may respond by selecting more social rather than non-social genes. The behaviour and social environment come first, setting the stage for future molecular evolution.In addition, the researchers have found that a similar genetic evolution happened independently in different species at different times, suggesting there is a unifying principle leading to the same social trait."There seems to be something about sociality specifically that is driving the genome to evolve in this way. It's a very interesting finding previously reported only in ants and honeybees," says lead researcher Associate Professor Sandra Rehan of the Faculty of Science.Rehan and her team looked at 16 different bee species across three different independent origins of eusociality -- the transition from solitary to social life where bees or other species live in a multigenerational group cooperatively caring for offspring in which there is a reproductive division of labour.They also sequenced the genome of six of the carpenter bee species -- one from North America, three from Australia, one from Japan and another from Kenya -- to find out how sociability effects genome evolution. They found that caring for the species' young in a group has in many cases led to the selection of social rather than non-social gene regulation."When we see the rise of queens and workers in complex sociality, we tend to see a rise of more complex genomic signatures, rates of evolution in the genome, but also the complexity of the structure of the genomes," says Rehan. "We know so little about how sociality evolves." Most bees are solitary, but some, like honeybees and carpenter bees, have transitioned to being social. Overall, though, sociality is relatively rare in the animal kingdom, and in bees."We are trying to understand how life evolved from simple to complex. We're mostly interested in how they got there. By studying these kinds of intermediatory groups and simple societies, we really can ask that question empirically," says Rehan."It gives us a window into the evolution of complexity and behaviour broadly. We can study it very practically in insects and bees because they show remarkable diversity in behaviour, but it gives us insights into all animals, including ourselves."
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Agriculture & Food
| 2,021 |
February 24, 2021
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https://www.sciencedaily.com/releases/2021/02/210224090704.htm
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New tool to study stress in root-colonizing bacteria
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One solution to agriculture's many challenges -- climate change-induced drought, less arable land, and decreased water quality, to name a few -- is to develop smarter fertilizers. Such fertilizers would aim not only to nourish the plant but also to maximize soil bacteria's positive effects on the plant. Tapping into a plant's microbiome may be the extra layer of defense crops need to thrive.
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In their study published on Dec. 4 in Key to this study is understanding that bacteria is not always bad."There's a lot more emphasis into what's called the 'microbiome revolution,' you know, the fact that you carry four pounds of bacteria on your body right now, and it's not all bad; in fact, it's mainly all good," said David Britt, full professor of biological engineering at Utah State. "Plants also have a microbiome, or 'second genome', and trying to understand how that microbiome interacts with the environment, and its plant host, is very important."Also key to this study is understanding that stress can be good. The bacterium studied here, for example, protects wheat from drought by forming a film around its roots. But by introducing tiny particles of micronutrients, those benefits could be fortified."A little bit of stress is necessary," said Britt. "You can actually prime the whole system to do better under drought."Equally important to the findings are the instrument and algorithms used in the study. This is the first time that researchers have used Raman spectroscopy to study OMVs from root-colonizing bacteria. "We could have done a lot of expensive assays to figure out all these different things that we were interested in looking at," said Elizabeth Vargis, associate professor of biological engineering at USU.Instead, Vargis explained, using Raman spectroscopy coupled with a machine learning algorithm enabled them to identify the type of stress the bacteria were experiencing when releasing these OMVs and the stress-dependent compositional changes therein. These observed changes have implications for cell-to-cell communication and bacteria-plant communication, which are essential to better understanding the microbiome.The study was supported in part by the National Science Foundation, the Utah State University Agriculture Experiment Station and the USDA National Institute of Food and Agriculture, but its implications extend beyond agriculture. Raman spectroscopy supported by the machine learning algorithms is a powerful tool that can be used in any biological study. "A cancer cell in your body will release extracellular vesicles before we can often detect the cancer through other methods," said Britt. "This is a very sensitive technique."
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Agriculture & Food
| 2,021 |
February 23, 2021
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https://www.sciencedaily.com/releases/2021/02/210223121629.htm
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Like wine, environmental conditions impact flavor of whiskey, study finds
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Flavor differences in whiskey can be discerned based solely on the environment in which the barley used to make the whiskey is grown, a new study co-authored by an Oregon State University researcher found.
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This is first scientific study that found the environmental conditions, or terroir, of where the barley is grown impacts the flavor of whiskey, said Dustin Herb, an author of the study and a courtesy faculty member in the Department of Crop and Soil Science at Oregon State University."Terroir is increasingly being used to differentiate and market agricultural products, most commonly wine, as consumers grow more interested in the origins of their food," Herb said. "Understanding terroir is something that involves a lot of research, a lot of time and a lot of dedication. Our research shows that environmental conditions in which the barley is grown have a significant impact."Herb, who is originally from Lebanon, Oregon, and earned his undergraduate and doctoral degrees from Oregon State, is the only American author of the study, which was published in the journal Herb's doctoral research at Oregon State with Pat Hayes, a barley breeder in the College of Agricultural Sciences, focused on the contributions of barley to beer flavor. Their research found notable differences in the taste of beers malted from barley varieties reputed to have flavor qualities.That research caught the attention of Waterford Distillery. The Irish distillery reached out to Herb, flew him to Ireland and asked him if he could design a study that would attempt to answer the question of whether terroir exists in whiskey. They dubbed it The Whisky Terroir Project. (Whiskey can be spelled with and without an "e.")Herb designed a study that involved planting two common commercial varieties of barley in Ireland -- Olympus and Laureate -- in two distinct environments: Athy, Co. Kildare and Buncloudy, Co. Wexford in 2017 and 2018. Athy is an inland site and Buncloudy is a coastal site. They were selected in part because they have different soil types and different temperature ranges and rainfall levels during the barley growing season.The crops of each barley variety at each site in each year were harvested, stored, malted and distilled in a standardized way. Once distilled, the product is called "new make spirit." (It isn't called whiskey until it is matured in a wooden cask for at least three years.)The researchers used gas chromatography mass spectrometry and the noses of a six-person trained sensory panel to determine which compounds in the barley most contributed to the aroma of the new make spirit.That analysis, along with further mathematical and statistical analysis, found that the environment in which the barley was grown had a greater contribution to the aroma of the whiskey than the variety of the barley. That was the clear indication of the impact terroir has on the new make spirit.Furthermore, the sensory analysis found distinct differences in the aroma characteristics of the new make spirit from the barley grown in each location. In Athy, it was more positively associated with sweet, cereal/grainy, feinty/earthy, oily finish, soapy, sour, stale and mouldy sensory attributes and in Bunclody it was more associated with dried fruit and solventy attributes."What this does is actually make the farmer and the producer come to the forefront of the product," Herb said. "It gets to the point where we might have more choices and it might provide an opportunity for a smaller brewer or a smaller distiller or a smaller baker to capitalize on their terroir, like we see in the wine industry with a Napa Valley wine, or Willamette Valley wine or a French Bordeaux."The sensory analysis also found differences in the aromatic profiles between the 2017 and 2018 seasons that were studied."This makes us think there might be a vintage aspect to the whiskey like wine, where you buy a 2019 or a 2020 or a 2016," Herb said. "Could the whiskey industry operate in a similar way, where someone is going to seek out a certain vintage of a certain year?"To answer that question, more research needs to be done, Herb said. That is a project the Whisky Terroir Project plans to tackle: examining flavor changes in the spirits as they mature in casks and to see what happens with the terroir impact.The team is also scaling up the research to study terroir in commercial-scale barley fields over a five-year period.In addition to Herb, who also works full-time as a plant breeder at Albany, Oregon-based OreGro, which develops turf and forage products, other authors of the paper are: Maria Kyraleou and Kieran Kilcawley of the Teagasc Food Research Park; Grace O'Reilly and Neil Conway of Waterford Distillery; and Tom Bryan of Boormalt.The research was funded by Enterprise Ireland Commercialization Fund in collaboration with Waterford Distillery.
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Agriculture & Food
| 2,021 |
February 23, 2021
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https://www.sciencedaily.com/releases/2021/02/210223113324.htm
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Parasitic plants conspire to keep hosts alive
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The plant that encourages kissing at Christmas is in fact a parasite, and new research reveals mistletoe has an unusual feeding strategy.
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Like other plants, mistletoe is capable of using sunlight to create its own food, a process called photosynthesis. However, it prefers to siphon water and nutrients from other trees and shrubs, using "false roots" to invade its hosts."Plants are autotrophic, they make their own food. Humans are heterotrophic, we eat it," explained UC Riverside plant-insect ecologist Paul Nabity. "Mistletoe are mostly heterotrophic, but they can switch if they want to."Nabity's team found when two mistletoes invade the same tree, they increase photosynthesis to get the nutrients they need, essentially sharing the tree and causing it less harm."They seem to know when they're attacking the same host, and can reduce the virulence of their attack," Nabity said.A new paper describing this finding was published today in the journal The Christmas mistletoe is a European species that tends to attack apple and other hardwood trees in central California. For this experiment, the researchers examined a native species of mistletoe found throughout the Sonoran and Mojave deserts that often grows on acacia, palo verde or mesquite trees.When researchers removed one of two mistletoes from a branch, they saw the plant left behind did not increase its photosynthesis, and in some cases reduced its water intake."It appears that the remaining mistletoe recognized it was no longer competing for resources," Nabity said.Often times, birds feed from and guard a fruiting mistletoe and in the process, defecate seeds into the same tree from which they came. A tree full of related mistletoes increases the parasite load for the host, though the infection may not be as severe as it otherwise would be if infected with unrelated plants.Nabity, who studies interactions between plants and insects, explained that communication among mistletoes is possible through a variety of methods. They are connected to a host's xylem, the tissue that trees use to move water and nutrients from the roots. It's possible the mistletoes send messages using the xylem. It's also possible they may "smell" one another.Plants produce chemical compounds and release them through their pores. These compounds evaporate quickly into the air, sending signals that can be received down wind.However it is that mistletoes communicate, Nabity says they doesn't necessarily need to be removed from infected trees.Forest managers have long maintained that removal will increase tree health. Though this may be true for an individual tree, mistletoe has an important role ecologically, benefitting birds and pollinators. It tends to flower in winter when nectar or pollen from many other plants is not yet available.Not only does mistletoe help other species, it may not hurt trees or shrubs as much as once feared."Don't remove mistletoe because you think they're all bad," he said.
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Agriculture & Food
| 2,021 |
February 22, 2021
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https://www.sciencedaily.com/releases/2021/02/210222124706.htm
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Tweaking corn kernels with CRISPR
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Corn -- or maize -- has changed over thousands of years from weedy plants that make ears with less than a dozen kernels to the cobs packed with hundreds of juicy kernels that we see on farms today. Powerful DNA-editing techniques such as CRISPR can speed up that process. Cold Spring Harbor Laboratory (CSHL) Professor David Jackson and his postdoctoral fellow Lei Liu collaborated with University of Massachusetts Amherst Associate Professor Madelaine Bartlett to use this highly specific technique to tinker with corn kernel numbers. Jackson's lab is one of the first to apply CRISPR to corn's very complex genome.
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DNA is divided into two parts: the gene and the regulatory regions that promote or suppress gene activity. Jackson says:"A lot of people were using CRISPR in a very simple sense just to disrupt genes completely, to knock out the gene. But we came up with this new idea to CRISPR the promoter regions that turn the gene on. And that is what gives this very interesting result where we can get the variation in traits that we need in agriculture."Jackson wanted to increase the number of kernels per cob. The corn kernel development pathway includes genes that promote stem cell growth and differentiation into distinct plant organs. Jackson and Liu focused on CLEs, a family of genes that act as a brake to stop stem cell growth. But the corn genome is complex. The CLE family contains almost 50 related genes, with promoter regions that vary from gene to gene. What parts are most important for kernel production? Liu says:"So we basically randomly targeted the promoter region: we have no idea which part of the promoter is important. So probably the next step, we will focus more on figuring out which part of the promoter is critical. And, then we probably will make our promoter CRISPR more efficient. We can get a better allele which can produce more grain yield or ear size."Cereal crops like maize are a major source of food for humans and feed for livestock. Jackson and Liu hope their new CRISPR strategy will increase crop yield per acre and make agriculture more sustainable.
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Agriculture & Food
| 2,021 |
February 22, 2021
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https://www.sciencedaily.com/releases/2021/02/210222092258.htm
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Advancing understanding of hop genome to aid brewers, medical researchers
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Oregon State University and U.S. Department of Agriculture researchers have significantly expanded the understanding of the hop genome, a development with important implications for the brewing industry and scientists who study the potential medical benefits of hops.
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"This research has the unique ability to impact several different fields," said David Hendrix, an associate professor in the Department of Biochemistry and Biophysics and the School of Electrical Engineering and Computer Science at Oregon State. "If you're talking to beer drinkers, they will be excited about the brewing side. If you are talking to the medical field, they are going to be excited about the pharmaceutical potential."The findings are outlined in a paper just published in the journal Demand for hops has surged in recent years as the craft beer industry has grown, fueled by beers, such as India pale ales, that are brewed with a lot of hops. This has led brewers to seek out new varieties of hops. With a better understanding of the hop genome, scientists will have an easier time developing new varieties, which may have qualities such as different flavor profiles or resistance to diseases that infect and damage hop plants."This really opens the door wide for breeding hops at the molecular level," Henning said. "We now have a much better understanding of how traits are being controlled and what genes are involved."Compounds founds in hops are also increasingly of interest to medical researchers. For example, scientists at Oregon State have shown that xanthohumol, a natural flavonoid found in hops, may aid in combating cancer and metabolic syndrome. Knowing more about hop genes and how they are regulated creates potential for better understanding how compounds are produced and finding other hop compounds that could improve people's health.Hops are part of the Cannabaceae family of plants, which also includes hemp and marijuana. In the just-published paper, the Oregon State researchers found gene structures in the hop genome that were similar to cannabidolic acid synthase, or CBDAS, which produces the precursor structure to CBD, the compound in cannabis plants that has surged in popularity in recent years because of its potential health benefits.The Oregon State researchers stressed that their finding doesn't necessarily mean that hops produce CBDA, but it raises questions about the potential to identify new genes involved in the production of different compounds associated with flavoring or therapeutic benefit, and the potential to uncover new compounds in hops.The researchers sequenced the genome of Cascade, a hop cultivar developed by USDA Agricultural Research Service in the 1960s and credited with helping to launch the craft beer movement. It is the second most widely grown hop variety in the United States today.The United States is the top hop producing country in the world and Washington, Oregon and Idaho account for nearly all the hop acreage in the United States. In 2019, production of hops in the United States was worth more than $600 million.Other scientists have attempted to sequence the hop genome, but they have had limited success because it is large -- similar in size to the human genome -- and complex, Hendrix said. The current research was made possible in part by new genome sequencing and assembly technology developed by Pacific Biosciences of California."The previous genomes were basically broken up," Hendrix said. "They were sequencing a lot of the genes, but they were isolated islands of the genome and they were not really getting the full context of what was going on in those islands. We were able to reveal a more complete and continuous genomic sequence."In addition to Hendrix and Henning, the lead author on this paper was Lillian K. Padgitt-Cobb and co-authors of the paper are: Jackson Wells, Brent Kronmiller, Justin Elser and Pankaj Jaiswal, all of Oregon State; Daniel Moore of USDA Agricultural Research Service; Sarah B. Kingan, Gregory Concepcion, Paul Peluso and David Rank, all of Pacific Biosciences of California.Funding for the sequencing was provided by Pacific Biosciences of California and Sierra Nevada Brewing Company. The research was also supported by funding from the U.S. Department of Agriculture.
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Agriculture & Food
| 2,021 |
February 17, 2021
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https://www.sciencedaily.com/releases/2021/02/210217151100.htm
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Changing livestock in ancient Europe reflect political shifts
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In ancient European settlements, livestock use was likely primarily determined by political structure and market demands, according to a study published February 17, 2021 in the open-access journal
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Zooarchaeology -- the study of animal remains from archaeological sites -- has great potential to provide information on past human communities. Livestock preferences are known to have changed over time in Europe, but little is known about how much these changes are influenced by environmental, economic, or political conditions of ancient settlements.In this study, Nieto-Espinet and colleagues gathered data from 101 archaeological sites across the northeastern Iberian Peninsula, ranging from the Late Bronze Age to Late Antiquity, a span of around 1700 years during which European cultural and agricultural practices underwent significant changes. At each site, they compared livestock remains with data on the local environment (including plant and climate data) and the economic and political conditions of the settlement.These data show that political and economic factors were most important in determining the species distribution and body size of ancient livestock. During the Late Bronze Age and Late Antiquity, when political systems were more fragmented and food production was focused more on local markets, livestock choice was more dependent upon local environmental conditions. But during the later Iron Age and the time of the Roman Empire, the demands of a pan-Mediterranean market economy favored more changes in livestock use independent of environmental factors. Zooarchaeology is thus a vital source of information for understanding political and economic changes through time.The authors add: "Archaeology reveals the influence of political systems on livestock practices over time."
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Agriculture & Food
| 2,021 |
February 17, 2021
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https://www.sciencedaily.com/releases/2021/02/210217151011.htm
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Insects silencing the alarm
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Like a scene from a horror movie, tomato fruitworm caterpillars silence their food plants' cries for help as they devour their leaves. That is the finding of a multidisciplinary team of researchers, who said the results may yield insights into the abilities of crop plants -- such as tomato and soybean -- to withstand additional stressors, like climate change.
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"We have discovered a new strategy whereby an insect uses saliva to inhibit the release of airborne plant defenses through direct manipulation of plant stomata," said Gary Felton, professor and head of the Department of Entomology at Penn State, noting that stomata are tiny pores on plant leaves that regulate gas exchange, including plant defensive emissions and carbon dioxide, between the plant and the environment.Specifically, the researchers studied the effects of a particular enzyme -- glucose oxidase (GOX) -- that occurs in the saliva of tomato fruitworm caterpillars (Helicoverpa zea) on plant stomata and plant defensive emissions, called herbivore-induced plant volatiles (HIPV)."HIPVs are thought to help protect plants from insect herbivores by attracting natural enemies of those herbivores and by alerting neighboring plants to the presence of herbivores nearby," Felton said. "Consequently, stomatal closure has the potential to alter interactions across the entire plant community."In their experiments, the researchers used CRISPR/Cas9, a technique for editing genomes, to produce caterpillars that lack the GOX enzyme. In separate glass chambers fitted with filter traps to collect HIPVs, they allowed the caterpillars with the non-functional enzyme, along with unmanipulated caterpillars, to feed on tomato, soybean and cotton plants for three hours. To examine the stomatal response to GOX, the team examined the plant leaves under a microscope and measured the size of the stomatal openings. Next, they extracted the volatile compounds from the filter traps and used gas chromatography, coupled with mass spectrometry, to identify and quantify the HIPVs."This study is the first to use CRISPR/Cas9-mediated gene editing to study the function of an insect salivary enzyme," said Po-An Lin, a graduate student in entomology at Penn State and the lead author of the paper. "Using pharmacological, molecular, and physiological approaches, we were able to show that this salivary enzyme plays a key role in insect-induced stomatal closure and likely the reduction of several important defensive emissions."Indeed, the team -- comprising experts in molecular biology, chemical ecology, plant physiology and entomology -- found that GOX, secreted by the caterpillar onto leaves, causes stomatal closure in tomato plants within five minutes, and in both tomato and soybean plants for at least 48 hours. They also found that GOX inhibits the emission of several HIPVs during feeding, including (Z)-3-hexenol, (Z)-jasmone and (Z)-3-hexenyl acetate, which are important airborne signals in plant defenses. Interestingly, they did not find an effect of GOX on the cotton plants, which, the team said, suggests that the impacts of GOX on stomatal conductance is species dependent.The team's results appeared in the Jan. 18 issue of Lin noted that the fact that tomato fruitworm caterpillars evolved a salivary enzyme that inhibits emissions of defensive volatiles in certain species suggests the importance of plant airborne defenses in the evolution of insect herbivores."Given the ubiquity of HIPVs in plants, it is likely that traits which influence HIPVs have evolved broadly among insect herbivores," he said.Not only do these insects damage individual plants, but they also may render them less able to withstand climate change."Stomata are important organs of plants that not only detect and respond to environmental stressors, but also play a central role in plant growth," said Felton. "Because stomata play an important role in regulating leaf temperature and leaf water content, our findings suggest that the control of stomatal opening by an insect could impact the plant's response to elevated temperatures occurring with climate change and response to water deficiency."Other Penn State authors on the paper include Yintong Chen, graduate student in molecular, cellular and integrative biosciences; Chan Chin Heu, a former postdoctoral researcher; Nursyafiqi Bin Zainuddin, graduate student in entomology; Jagdeep Singh Sidhu, graduate student in horticulture; Michelle Peiffer, research support assistant in entomology; Ching-Wen Tan, postdoctoral scholar in entomology; Jared Ali, assistant professor of entomology; Jason L. Rasgon, professor of entomology and disease epidemiology; Jonathan Lynch, Distinguished Professor of Plant Science; and Charles T. Anderson, associate professor of biology. Also on the paper are Duverney Chaverra-Rodriguez, postdoctoral scholar, University of California, San Diego; Anjel Helms, assistant professor of chemical ecology, Texas A&M University; and Donghun Kim, assistant professor, Kyungpook National University.The National Science Foundation, Agricultural and Food Research Initiative Program of the United States Department of Agriculture and a Hatch Project Grant supported this research.
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Agriculture & Food
| 2,021 |
February 17, 2021
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https://www.sciencedaily.com/releases/2021/02/210217175205.htm
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Researchers solve riddle of plant immune system
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How do plants build resilience? An international research team led by the University of Göttingen studied the molecular mechanisms of the plant immune system. They were able to show a connection between a relatively unknown gene and resistance to pathogens. The results of the study were published in the journal
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Scientists from "PRoTECT" -- Plant Responses To Eliminate Critical Threats -- investigated the molecular mechanisms of the immune system of a small flowering plant known as thale cress (Arabidopsis thaliana). PRoTECT is an International Research Training Group (IRTG) founded in 2016 with the University of Göttingen and the University of British Columbia in Vancouver. The aim of the study was to identify and describe a specific gene of a particularly disease-resistant plant. The team observed that plants that do not possess this previously little known gene strongly accumulate active acids. In addition, these plants show a significantly increased resistance to pathogens. However, this resistance is accompanied by extremely reduced growth."We have succeeded in deciphering the molecular connection between the gene product and the inactivation of the acids during normal plant growth," says Professor Ivo Feußner from the Göttingen Centre for Molecular Biosciences (GZMB). Understanding this interaction provides scientists with a promising approach to improving the natural resistance of crops. "The basic results can be used to help breeders isolate less susceptible plants," says Lennart Mohnike, first author of the study. "This offers scientists an important way to increase food security and could lead to reduced pesticide use."
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Agriculture & Food
| 2,021 |
February 16, 2021
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https://www.sciencedaily.com/releases/2021/02/210216185910.htm
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Common weed killers favor antibiotic resistant bacteria
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The use of weed killers can increase the prevalence of antibiotic resistant bacteria in soil, a new study from the University of York shows.
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Herbicides are one of the most widely used chemicals in agriculture and while these compounds are used to target weeds, they can cause damage to soil microbes, such as bacteria and fungi, potentially changing the ecological properties of microbial communities.Scientists from China and the UK studied the effect of three widely used herbicides called glyphosate, glufosinate and dicamba on soil bacterial communities.Using soil microcosms, researchers discovered that herbicides increased the relative abundance of bacterial species that carried antibiotic resistance genes. This was because mutations that improved growth in the presence of herbicides also increased bacterial tolerance to antibiotics. Herbicide exposure also led to more frequent movement of antibiotic resistance genes between bacteria.Similar patterns were found in agricultural fields across 11 Chinese provinces where herbicide application history, and the levels of herbicide residues in soils, were linked to increased levels of antibiotic resistance genes.Dr Ville Friman from the Department of Biology said: "Our results suggest that the use of herbicides could indirectly drive antibiotic resistance evolution in agricultural soil microbiomes, which are repeatedly exposed to herbicides during weed control."Interestingly, antibiotic resistance genes were favoured at herbicide concentrations that were not lethal to bacteria. This shows that already very low levels of herbicides could significantly change the genetic composition of soil bacterial populations. Such effects are currently missed by ecotoxicological risk assessments, which do not consider evolutionary consequences of prolonged chemical application at the level of microbial communities."While antibiotic resistance genes are not harmful per se, they will reduce the efficiency of antibiotics during clinical treatments. Keeping the frequency of resistance genes low will hence prolong the long-efficiency of antibiotics. As resistance genes can easily move between environments, agricultural fields could be globally important source for resistance genes"The study concludes that the effects of these herbicide concentrations on microbial communities should be re-evaluated to fully understand the associated risks for the prevalence of antibiotic resistance genes.
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Agriculture & Food
| 2,021 |
February 16, 2021
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https://www.sciencedaily.com/releases/2021/02/210216133437.htm
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Perceiving predators: Understanding how plants 'sense' herbivore attack
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Nature has its way of maintaining balance. This statement rightly holds true for plants that are eaten by herbivores -- insects or even mammals. Interestingly, these plants do not just silently allow themselves to be consumed and destroyed; in fact, they have evolved a defense system to warn them of predator attacks and potentially even ward them off. The defense systems arise as a result of inner and outer cellular signaling in the plants, as well as ecological cues. Plants have developed several ways of sensing damage; a lot of these involve the sensing of various "elicitor" molecules produced by either the predator or the plants themselves and initiation of an "SOS signal" of sorts.
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In a recently published review in the journal When the same herbivorous animal comes to eat the plant multiple times, the plant learns to recognize its feeding behavior and records the "molecular pattern" associated with it. This is termed "herbivore-associated molecular patterns" or HAMPs. HAMPs are innate elicitors. Other plant elicitors include plant products present inside cells that leak out because of the damage caused by herbivory. Interestingly, when an herbivorous insect eats the plant, the digestion products of the plant cell walls and other cellular components become part of the oral secretions (OS) of the insect, which can also function as an elicitor!Prof. Arimura highlights the fact that with the advancement of high-throughput gene- and protein-detecting systems, the characterization of elicitors of even specific and peculiar types of herbivores, such as those that suck cell sap and do not produce sufficient amounts of OS, has become possible. The proteins present in the salivary glands of such insects could be potential elicitors as they enter the plant during feeding. He explains, "RNA-seq and proteomic analyses of the salivary glands of sucking herbivores have led to the recent characterization of several elicitor proteins, including a mucin-like salivary protein and mite elicitor proteins, which serve as elicitors in the leaves of the host plants upon their secretion into plants during feeding."The review also highlights some peculiar elicitors like the eggs and pheromones of insects that plants can detect and initiate a defense response against. In some special cases, the symbiotic bacteria living inside the insect's gut can also regulate the defense systems of the plants.And now that we have understood different types of elicitors, the question remains -- what signaling mechanisms do the plants use to communicate the SOS signal?So far, it has been hypothesized that the signaling is made possible by proteins transported through the vascular tissue of plants. Interestingly, there is evidence of airborne signaling across plants, by a phenomenon called "talking plants." Upon damage, plants release volatile chemicals into the air, which can be perceived by neighboring plants. There is also evidence of epigenetic regulation of defense systems wherein plants maintain a sort of "genetic memory" of the insects that have attacked them and can fine-tune the defense response accordingly for future attacks.Given the improvement in knowledge of the mechanisms of plant defense systems, we can embrace the possibility of a "genetic" form of pest control that can help us circumvent the use of chemical pesticides, which, with all their risks, have become a sort of "necessary evil" for farmers. This could usher in modern, scientifically sound ways of organic farming that would free agricultural practices from harmful chemicals.
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Agriculture & Food
| 2,021 |
February 16, 2021
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https://www.sciencedaily.com/releases/2021/02/210216114920.htm
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Integrating maths and plant science to explain how plant roots generate a hormone gradient
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The research team that developed a biosensor that first recorded that a distinct gradient of the plant growth hormone gibberellin correlated with plant cell size has now revealed how this distribution pattern is created in roots.
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Starting when a plant embryo forms within a seed and continuing throughout the plant lifecycle, undifferentiated stem cells undergo radical transformations into specialised root, stem, leaf and reproductive organ cells. This transformation relies on a suite of molecules called phytohormones that, much like human hormones, can move between cells and tissues and trigger distinct biological processes across the bodyplan. While it was not known at the time, mutations involving the gibberellin class of phytohormones were behind the development of many of the high-yielding semi-dwarf wheat and rice varieties that helped drive the Green Revolution in the 1950s and 60s.The mutations resulted in shorter stems, enabling the crop plants to redirect energy into growing grain rather than stems and leaves and also prevented lodging caused when tall spindly plants fall over before harvest. We now know through advances in molecular and genetic tools that gibberellins (GA) regulate growth and development throughout the plant lifecycle -- from germinating seeds, elongating stems and roots, to the formation of flowers. It is therefore not surprising that GA continues to attract the interest of plant scientists investigating how hormones control plant growth and as a possible target for future crop improvements.A collaboration between the research teams of Alexander Jones, Sainsbury Laboratory at the University of Cambridge, and Leah Band and Markus Owen at the University of Nottingham, explain the biochemical steps responsible for a distinctive GA distribution seen in plant growth in "As key regulators of plant growth and development, understanding plant hormones is crucial for understanding plant growth dynamics, how they respond to their environment, and to help identify future targets for improved food security," said first-author Dr Annalisa Rizza."GA is known to regulate cell multiplication and cell expansion to increase the growth root rate , but we as yet don't have a full picture of how. We had previously observed there was a distinct longitudinal gradient of GA from root tip to root elongation zone that correlated with cell size in growing roots of the model plant Arabidopsis thaliana. We also observed an exogenous-GA-generated gradient with faster accumulation of GA in larger cells, but we did not know how these patterns were being created."To help find the answer, the researchers combined mathematical models with experimental observations to take a deep dive into the cells to see what biochemical and/or transport activities might be responsible.Mathematicians from the University of Nottingham, Dr Leah Band and Professor Markus Owen, developed a computational model to simulate the hormone GA dynamics in the plant root, which enabled them to test how different processes contribute to the GA gradient. They compared the output of their computer simulations to the experimental observations from the GA biosensor developed by the Jones research group."Having considered various scenarios, we found that the model predictions could only agree with the GA biosensor data provided the elongation-zone cells have high GA synthesis and increased permeability" added Dr Band.The next step was to test these predictions through experiments. Using the GA biosensor, the team examined the key steps involved in GA biosynthesis and pinpointed key rate limiting steps associated with enzymes involved in GA biosynthesis and that differential permeability in cell membranes were also playing a key role in creating GA gradients.They showed that each region in the root has a different combination of important regulatory steps, a level of information that was previously not accessible to researchers. Even more surprising, an important step that was generally thought to be rate limiting was the least important for setting the position and slope of the root GA gradient.In addition to local synthesis of GA, the ability of GA to move between cells is also considered an important factor. The team looked at the permeability of cell membranes to GA and found differences in cell permeability were contributing to the creation of the exogenous-GA-generated-gradient."Tiny amounts of these chemical hormones can reprogramme a plant cell and completely change its growth and physiology. Which plant cells produce these chemicals? Where and when do these chemical hormones go? These are the core questions that we are trying to answer," explained Dr Jones."These findings help explain which components are playing the important roles contributing to how plants control the distribution of a mobile hormone. There are multiple components involved in this -- processes that make more GA, take it away and transport it from and into the cell all play a part. These can then be targets for engineering nuanced changes. The Green Revolution was great, but there are negative side effects that could be eliminated with more fine scale perturbations in the future."This detailed understanding of how GA distribution relates to root growth and how these gradients are controlled provides a valuable model for progressing our understanding of how hormone distributions influence how plants grow."
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Agriculture & Food
| 2,021 |
February 16, 2021
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https://www.sciencedaily.com/releases/2021/02/210216114914.htm
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Campylobacter strains exchange genes, can become more virulent and antibiotic resistant
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New research from North Carolina State University has found that Campylobacter bacteria persist throughout poultry production -- from farm to grocery shelves -- and that two of the most common strains are exchanging genetic material, which could result in more antibiotic-resistant and infectious Campylobacter strains.
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Campylobacter is a well-known group of foodborne bacteria, spread primarily through consumption of contaminated food products. In humans it causes symptoms commonly associated with food poisoning, such as diarrhea, fever and cramps. However, Campylobacter infections also constitute one of the leading precursors of Guillain-Barré syndrome, a serious complication that can cause permanent disability and paralysis. Poultry is a known reservoir of the bacteria."There are two strains of Campylobacter that we're concerned with: C. coli and C. jejuni," says Maj. Dawn Hull, Army veterinarian, current Ph.D. student at NC State and lead author of the study. "C. jejuni causes up to 90% of human Campylobacter infections, but the good news is that this strain is less likely to carry multidrug-resistant genes. C. coli is twice as likely to contain multidrug-resistant genes, but it's a less effective human pathogen. Multidrug resistant means that the bacteria have genes that are resistant to three or more antimicrobial classes."Both strains are commonly found throughout the poultry production process in North Carolina, according to corresponding author Sid Thakur, professor of population health and pathobiology and director of global health programs at NC State and the College of Veterinary Medicine."Since Campylobacter has a fairly 'plastic' genome, the strains can exchange genetic material," Thakur says. "If C. coli starts to take in a lot of C. jejuni's genetic material and increases its virulence, then it will cause larger numbers of infections that are antibiotic resistant, which could become a big public health issue. Likewise, if C. jejuni takes up antibiotic-resistant genes from C. coli, the same thing happens."The team sampled chicken and turkey from retail grocery stores across North Carolina during 2018-2019. They compared Campylobacter isolates from the meat to USDA samples taken from poultry farms and production facilities in North Carolina. C. coli was most prevalent on farms and production facilities, at 54% and 60% for chicken isolates respectively, while C. jejuni was found in 69% of retail chicken meat.They then tested the isolates from food animals and meat for antimicrobial-resistant (AMR) genes and found that 90% of both C. coli and C. jejuni contained at least one AMR gene while 43% contained resistance genes to three or more antibiotic drug classes. Twenty-four percent of C. jejuni included resistance genes to fluoroquinolones, the "last line of defense" against Campylobacter.Finally, the team noted the appearance of a significantly higher number of new Campylobacter strains -- 21 -- in 2019 compared to only two in 2018. This indicates extensive changes occurring in the Campylobacter genome that have the potential to increase its virulence and drug resistance profile."If you go to a supermarket and pick 10 different chicken breasts, four will have Campylobacter, and of those four at least one will have a fluoroquinolone-resistant Campylobacter," Thakur says. "This trend has been pretty consistent over the last 10 years. Seeing a sudden jump in resistant sequence types is concerning.""This study shows that genomic exchange is happening between C. coli and C. jejuni, and that there is increasing antimicrobial resistance in Campylobacter found in N.C. poultry production," Hull says. "Campylobacter is the worldwide leading cause for foodborne illness, so tracking this exchange is crucial to preventing transmission and providing future treatments."The research appears in
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Agriculture & Food
| 2,021 |
February 15, 2021
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https://www.sciencedaily.com/releases/2021/02/210215092424.htm
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Invasive flies prefer untouched territory when laying eggs
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A recent study finds that the invasive spotted wing drosophila (
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To avoid consumer rejection, there are extensive measures in place to avoid infestation, and to prevent infested fruit from reaching the marketplace."Ultimately, we're talking about hundreds of millions of dollars in potential crop losses and increases in pest-management costs each year in the United States," says Hannah Burrack, co-author of a paper on the study and a professor of entomology at North Carolina State University. "These costs have driven some small growers out of business."The first step toward addressing an invasive pest species is understanding it. And two fundamental questions that we had are: Which plants will this species attack? And why does it pick those plants?"One of the things that researchers noticed when observing infestations on farms was that the species' egg-laying behavior was different, depending on the size of the infestation.When To better understand the egg-laying behavior of Specifically, the researchers found that, given a choice, female "It doesn't matter if the other flies lay eggs," Burrack says. "It doesn't even matter if the other flies are male or female. It only matters if other flies have touched a piece of fruit. If untouched fruit is available, "We're not sure if the flies leave behind a chemical or bacterial marker, or something else entirely -- but the flies can tell where other flies have been."The researchers say that the next step is to determine what, exactly, the "If we can get a better understanding of what drives the behavior of this species, that could inform the development of new pest-control techniques," Burrack says. "We're not making any promises, but this is a significant crop pest -- and the more we know, the better."The work was done with support from: the U.S. Department of Agriculture National Institute of Food and Agriculture's Organic Agriculture Research and Extension Initiative, under grants 2018-02859 and 2015-07403; USDA's Animal and Plant Health Inspection Service, under cooperative agreement 17-8130-0194-CA; National Science Foundation Integrated Graduate Education and Research Training grant number 1068676; and an Egyptian government scholarship to Aly.
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Agriculture & Food
| 2,021 |
February 12, 2021
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https://www.sciencedaily.com/releases/2021/02/210212113929.htm
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Biodiversity protects bee communities from disease
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A new analysis of thousands of native and nonnative Michigan bees shows that the most diverse bee communities have the lowest levels of three common viral pathogens.
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University of Michigan researchers netted and trapped more than 4,000 bees from 60 species. The bees were collected at winter squash farms across Michigan, where both managed honeybee colonies and wild native bees pollinate the squash flowers.All but one species -- Apis mellifera, the common European honeybee -- are native bees. The number of bee species found at each farm ranged from seven to 49.Consistently, lower virus levels were strongly linked to greater species richness among the local bee communities. The study was published online Feb. 11 in the journal "This result is exciting because it suggests that promoting diverse bee communities may be a win-win strategy to simultaneously reduce viral infections in managed honeybee colonies while helping to maintain native bee biodiversity," said study lead author Michelle Fearon, a postdoctoral researcher in the University of Michigan Department of Ecology and Evolutionary Biology."In light of recent global pollinator population declines that are due in part to the spread of pathogens, these results offer hope that conservation efforts could also broadly benefit pollinator health," said Fearon, who conducted the study for her doctoral dissertation. She is now pursuing a follow-up study that explores how natural areas keep pollinator communities healthy.The Ecology study is the first to show that high levels of biodiversity within bee communities can help dilute the harmful effects of viral pathogens. Support for this "dilution effect" has been reported in other host -- pathogen systems -- such as tick-borne Lyme disease -- but this is the first time it's been seen with pollinator viruses. The idea of a dilution effect remains controversial among ecologists, however.Fearon and her colleagues collected 4,349 bees at 14 Michigan winter squash farms over two summers. Michigan winter squashes include acorn squash, butternut squash, spaghetti squash and pumpkins.Honeybees were found at all of the sites, and a diverse array of native bees were also present in the squash fields and along field edges. In fact, native pollinators were much more common visitors to the squash flowers than honeybees at most locations.Four types of bees -- the European honeybee, the eastern bumblebee (Bombus impatiens), the squash bee (Eucera pruinosa) and several species of sweat bee (genus Lasioglossum) -- were the most consistently abundant species among the bee communities that were sampled.Those four groups were tested for the presence of three viruses that commonly infect managed honeybee colonies: deformed wing virus, black queen cell virus and sacbrood virus.These pathogens contribute to high rates of colony loss among honeybees, and there are no widely available treatments that beekeepers can use to control them. Previous studies suggested that native bees are less commonly infected and may be less likely to transmit the pathogens to other bees.The viruses spread as bees move from flower to flower, gathering pollen and nectar and pollinating the plants in the process. Consumption of virus-contaminated pollen is believed to be a primary mode of transmission.For each of the four target bee groups in the U-M study, researchers found that lower viral prevalence was strongly linked to greater biodiversity of the local bee community: the more bee species present, the lower the percentage of bees infected.Species-rich communities included many native bee species, which apparently helped to dilute the impact of the pathogens."Native bees likely reduce the viral prevalence in pollinator communities because they are poorer viral hosts than honeybees. This means that some native bees don't get as sick as honeybees and are less likely to spread the virus to other bees," said study co-author Elizabeth Tibbetts, a professor in the U-M Department of Ecology and Evolutionary Biology who was Fearon's dissertation adviser."So, bees from pollinator communities with lots of species are less likely to get sick because they are sharing flowers with many bee species that are less likely to spread the virus, while bees from communities dominated by honeybees are more likely to share flowers with honeybees that are good at spreading the virus," Tibbetts said.Bees are indispensable pollinators, supporting both agricultural productivity and the diversity of flowering plants worldwide. In recent decades, both native bees and managed honeybee colonies have seen population declines blamed on multiple interacting factors including habitat loss, parasites and disease, and pesticide use."We found encouraging evidence that pollinator conservation efforts can broadly benefit the health of both managed honeybee colonies and native bees," Fearon said. "This management strategy could be especially crucial in agricultural areas where crop flowers are visited by both honeybees and native bees -- places that may be hot spots for viral transmission among bee species."Funding for the work was provided by the National Science Foundation, the North American Pollinator Protection Campaign, the Pollinator Partnership, The Garden Club of America, U-M's Rackham Graduate School, and the U-M Department of Ecology and Evolutionary Biology.
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Agriculture & Food
| 2,021 |
February 11, 2021
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https://www.sciencedaily.com/releases/2021/02/210211090120.htm
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Biosensors monitor plant well-being in real time
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Researchers at Linköping University, Sweden, have developed biosensors that make it possible to monitor sugar levels in real time deep in the plant tissues -- something that has previously been impossible. The information from the sensors may help agriculture to adapt production as the world faces climate change. The results have been published in the scientific journal
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The primary source of nutrition for most of the Earth's population is mainly plants, which are also the foundation of the complete ecosystem on which we all depend. Global population is rising, and rapid climate change is at the same time changing the conditions for crop cultivation and agriculture."We will have to secure our food supply in the coming decades. And we must do this using the same, or even fewer, resources as today. This is why it is important to understand how plants react to changes in the environment and how they adapt," says Eleni Stavrinidou, associate professor in the Laboratory of Organic Electronics, Department of Science and Technology at Linköping University.The research group at Linköping University led by Eleni Stavrinidou, together with Totte Niittylä and his group from Umeå Plant Science Centre, has developed sugar sensors based on organic electrochemical transistors that can be implanted in plants. The biosensors can monitor the sugar levels of trees in real time, continuously for up to two days. The information from the sensors can be related to growth and other biological processes. Plants use sugars for energy, and sugars are also important signal substances that influence the development of the plant and its response to changes in the surrounding environment.While biosensors for monitoring sugar levels in humans are widely available, in particular the glucometer used by people who have diabetes, this technology has not previously been applied to plants."The sensors now are used for basic plant science research but in the future they can be used in agriculture to optimise the conditions for growth or to monitor the quality of the product, for example. In the long term, the sensors can also be used to guide the production of new types of plant that can grow in non-optimal conditions," says Eleni Stavrinidou.The mechanisms by which plant metabolism is regulated and how changes in sugar levels affect growth are still relatively unknown. Previous experiments have typically used methods that rely on detaching parts of the plant. However, the sensor developed by the research group gives information without damaging the plant and may provide further pieces of the puzzle of how plant metabolism works."We found a variation in sugar levels in the trees that had not been previously observed. Future studies will focus on understanding how plants sugar levels change when plants are under stress," says Eleni Stavrinidou.The research is mainly funded by the European Union's Horizon 2020 research and innovation programme. Additional funding comes from: the Wallenberg Wood Science Center, the Swedish Foundation for Strategic Research, the Knut and Alice Wallenberg Foundation, the Swedish Research Council, and the Swedish Strategic Research Area in New Functional Materials (AFM) at Linköping University.Note: The plants used in the experiments are hybrid aspen, Populus tremula.
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Agriculture & Food
| 2,021 |
February 8, 2021
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https://www.sciencedaily.com/releases/2021/02/210208100531.htm
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Richness of plant species reduces the number of viral infections in meadows
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A study carried out at the University of Helsinki indicates that agricultural activity confuses the mechanisms that regulate the occurrence of plant diseases in nature. A wider variety of virus species was found in meadows close to agricultural fields compared to those located in natural surroundings, with the richness of plant species having no effect on the number of virus species. However, maintaining biodiversity is worthwhile, as plant richness did reduce the number of viral infections in the meadows.
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An increasing share of the global land area is used for agricultural purposes, with more and more of the remaining area located at the boundary between agricultural and natural land, also known as the agro-ecological interface. At the same time, biodiversity is narrowing and epidemics are threatening humans, animals and plants. In the wild, species interact with one another, making the richness and distribution of host species in a given area impact the occurrence of pathogens as well.The Research Centre for Ecological Change headed by Professor Anna-Liisa Laine at the University of Helsinki surveyed the effects of the proximity of cultivated land to viral distribution in ribwort plantain (Plantago lanceolata) meadows in the Åland Islands."The meadow network on the Åland Islands is favourable for research, as we have previously identified five new plant viruses in the area. It was the distribution of these viruses we were now able to investigate, thanks to the techniques we have developed for the purpose. We chose for our study meadows located either on the edges of fields or far away from agricultural land," says researcher Hanna Susi from the University of Helsinki's Faculty of Biological and Environmental Sciences, who headed the study.At the agro-ecological interface, many factors that affect the spread of plant diseases, including soil nutrients as well as the diversity and density of plant species, change suddenly. The researchers observed that the effect of agriculture extends, however, to the areas surrounding fields."Surprisingly enough, we observed no differences in species richness or community composition between plant communities situated on field edges and wild populations further away," Susi notes.The researchers found that the meadows on the edges of fields had a higher number of virus species whose numbers were not reduced by plant richness, contrary to what was seen in meadows surrounded by natural environments. At the same time, the richness of plants reduced viral infections in both meadow types. The study conducted by Laine's group indicates that agricultural activity confuses the mechanisms that regulate the occurrence of diseases in the wild."However, maintaining biodiversity is worthwhile, as the richness of plant species did reduce the number of viral infections in the meadows -- regardless of location," Susi says.
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Agriculture & Food
| 2,021 |
February 4, 2021
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https://www.sciencedaily.com/releases/2021/02/210204192528.htm
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In symbiosis: Plants control the genetics of microbes
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Researchers from the University of Ottawa have discovered that plants may be able to control the genetics of their intimate root symbionts -- the organism with which they live in symbiosis -- thereby providing a better understanding of their growth.
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In addition to having a significant impact on all terrestrial ecosystems, their discovery may lead to improved eco-friendly agricultural applications.We talked to research lead Nicolas Corradi, Associate Professor in the Department of Biology and Research Chair in Microbial Genomics at the University of Ottawa, and lead author Vasilis Kokkoris, Postdoctoral Fellow in the Corradi Lab, to learn more about their recent study published in the journal Can you tell us more about your findings?Nicolas Corradi: "We have uncovered a fascinating genetic regulation between plants and their microbial symbionts, known as Arbuscular Mycorrhizal Fungi (AMF).AMF are plant obligate symbionts that grow within the plant roots and help their hosts to grow better and be more resistant to environmental stressors.AMF genetics have long been mysterious; while typical cells carry one nucleus, the cells of AMF carry thousands of nuclei that can be genetically diverse. How these nuclei communicate with each other and whether the plants can control their relative abundance, has been a total mystery.Our work provides insights into this unique genetic condition:1- We demonstrate that the host plant symbiont influences the relative abundance of thousands of co-existing nuclei carried by their fungal symbionts.2- We find evidence that co-existing nuclei of different genetic backgrounds cooperate, rather than compete with one another thus potentially maximizing growth benefits for both the fungi and their plant partners."How did you come to these conclusions?Vasilis Kokkoris: "We implemented a novel molecular approach accompanied by advanced microscopy and mathematical modelling. Every single AMF spore carries hundreds of nuclei (see image).By analyzing single spores, we were able to quantify the genetics of thousands of nuclei and define their relative abundance in different fungal strains and across plant species.To ensure that we accurately analyze single nuclei, we used advanced microscopy to visualize and count the nuclei in the spores.Lastly, we used mathematical modelling to prove that the observed abundance of nuclear genotypes we identified cannot be a product of luck but instead is the result of a driven cooperation between them.To better understand what is regulating the AMF nuclei we grew different AMF strains with different hosts and found that plants have control of the relative abundance of the fungal nuclei."What are the impacts of your discovery?Nicolas Corradi: "For many years, AMF have been considered to be genetic peculiarities and far away from model organisms. Inconsistencies are commonly observed in plant-AMF experiments. For example, growing the same fungal strain with different plants can lead to drastically different plant yields. For a long time, this variance in plant growth was blamed on the AMF mysterious genetics.Our research provides an answer as we demonstrate that the genetics of these fungi, and their effect on plant growth, can be manipulated by plants thus explaining the reason for the observed variability on plant growth.From an environmental standpoint, this new knowledge allows for better understanding how plants can influence the genetics of their symbiotic partners, thus influencing entire terrestrial ecosystems.From an economic standpoint, it opens doors to improved sustainable agricultural applications."
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Agriculture & Food
| 2,021 |
February 3, 2021
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https://www.sciencedaily.com/releases/2021/02/210203162252.htm
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Kangaroo overgrazing could be jeopardizing land conservation, study finds
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As a native animal, kangaroos aren't typically considered a threat to Australian vegetation.
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While seen as a pest on farmland -- for example, when competing with livestock for resources -- they usually aren't widely seen as a pest in conservation areas.But a new collaborative study led by UNSW Sydney found that conservation reserves are showing signs of kangaroo overgrazing -- that is, intensive grazing that negatively impacts the health and biodiversity of the land.Surprisingly, the kangaroos' grazing impacts appeared to be more damaging to the land than rabbits, an introduced species."The kangaroos had severe impacts on soils and vegetation that were symptomatic of overgrazing," says Professor Michael Letnic, senior author of the paper and professor in conservation biology and ecosystem restoration at UNSW Science."Not only did the areas grazed by overabundant kangaroos have fewer species of plants, but the soils were depleted in nutrients and were compacted -- which means that less water can be absorbed by the soil when it rains."The findings, published late last year in While kangaroos and rabbits can roam freely in these areas, each reserve has several small 'exclosures' -- fenced sections designed to keep unwanted animals out -- to help native vegetation regenerate. These areas excluded either rabbits, kangaroos, or both.The team compared the health of the soil and vegetation inside the exclosures with the areas outside. They looked for signs of land degradation specific to each species and monitored animal populations in the area.Kangaroos were the most populous herbivore across all reserves."We tend to think of kangaroo grazing as a natural process because they're a native species, but there are now too many kangaroos in conservation reserves," says Prof. Letnic. "Their grazing can be detrimental for biodiversity conservation."We need to start thinking about developing strategies to restore the balance and reduce the adverse impacts of overgrazing -- particularly during times of drought."Dr Graeme Finlayson, SA Arid Rangeland ecologist for Bush Heritage, says overgrazing had dire implications for other native species who rely on vegetation cover and associated food resources to survive. Bush Heritage owns and manages Boolcoomatta Reserve, one of the conservation sites included in this study."One of the key species that is likely to be impacted by overgrazing is the critically endangered Plains Wanderer ("Overgrazing and then a two-year drought which have greatly reduced cover and food resources are likely to be key drivers behind this."Ecosystems are fragile and can be thrown off-balance by an overabundance of one species.For example, kangaroo overgrazing leads to a lower plant diversity -- and fewer plants means less food and shelter for other animals.Dr Charlotte Mills, lead author of the study and visiting fellow at UNSW Science, hopes that this study paves the way for future research into how threatened species might be affected by kangaroo overgrazing."There isn't a lot of research about how kangaroos differentially affect different parts of the ecosystem," she says. "A lot of past research has focused on rabbits."The team found that rabbits still had negative impacts on the land -- for example, there were more woody plants in exclosures that rabbits couldn't get to -- but not to the same degree as kangaroos."Rabbits and other introduced herbivores like goats are often considered the main contributor to overgrazing in Australia," says Dr Mills."But we found kangaroos had a greater impact on the land -- and on the grass in particular."Human intervention is a key contributing factor to the growth of kangaroo populations."Humans have been culling dingoes -- kangaroos natural predators," says Prof. Letnic."We've been making it easier for kangaroos to thrive."Conservation reserves help protect native vegetation from threats like grazing from livestock or introduced species like rabbits or goats.The findings suggest native species might need to be kept in check, too."If we aren't managing threats that have been exacerbated by human activities -- such as overabundant kangaroo populations -- then we're not using conservation areas in the best way that we can," says Dr Mills.Prof. Letnic says that while kangaroo populations on farms have been managed for 100 years, they have generally been unmanaged on conservation reserves."This research changes thinking by suggesting it's time to ask some questions," he says. "We need to ask whether there are too many kangaroos and if they're having unacceptable impacts on our conservation reserves."Dr Finlayson says it's a difficult balance to get right, but a humane and science-led approach is best for the entire ecosystem."Reducing total grazing pressure clearly has great conservation benefit but can be a challenging issue when this requires the management of native species, such as kangaroos," he says."We need to make sure we have a landscape-wide strategy, working across government, conservation and agriculture, to ensure we tackle this problem together, and in the most humane way possible."
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Agriculture & Food
| 2,021 |
February 3, 2021
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https://www.sciencedaily.com/releases/2021/02/210203144555.htm
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The business of bees
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The economic value of insect pollinators was $34 billion in the U.S. in 2012, much higher than previously thought, according to researchers at the University of Pittsburgh and Penn State University. The team also found that areas that are economically most reliant on insect pollinators are the same areas where pollinator habitat and forage quality are poor.
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"Pollinators like bees play an extremely important role in agriculture," explained senior author Vikas Khanna, Wellington C. Carl Faculty Fellow and associate professor of civil and environmental engineering at Pitt's Swanson School of Engineering. "The insects that pollinate farmers' crops underpin our ecosystem biodiversity and function, human nutrition, and even economic welfare."But some of those busy little bees are headed for crisis -- one-third of managed honey bee colonies die each winter in the U.S., and populations of many wild pollinator species are showing declines as well.Using publicly available price and production data and existing pollination field studies, the team determined economic dependence of U.S. crops on insect pollination services at the county level, as well as areas where the habitat for wild pollinators has been reduced. One key finding is that the economic value that is dependent on insect pollination totaled $34 billion in 2012, much higher than previously thought. The team looked at 2012 because it was the most recent year for which data were available."The value of insects as part of our economy is apparent when you look at the well-established connection between farming and beekeeping. Farmers sometimes will buy or rent bee colonies to help pollinate their crops when there aren't enough wild bees in the area," said Khanna. "We've found that some of the areas that are economically most reliant on insect pollinators are the same areas where pollinator habitat and forage quality are poor."The researchers found that 20 percent of U.S. counties produce 80 percent of total economic value that can be attributed to wild and managed pollinators. Their findings will inform conservation efforts and ensure sustainable production of key crops.They also identified the key areas that produce economically and nutritionally valuable crops and are highly dependent on pollinators -- areas that are at risk if wild pollinator populations continue to decline. By overlaying maps of predicted wild bee abundance, the researchers could identify areas where there was high economic dependence on pollinators but low predicted abundance of pollinators.The research suggests a need for farmers to mitigate the shrinking bee populations by providing a more suitable habitat for the insects to thrive."Our study showcases the increasing importance of pollinators to supporting U.S. agricultural systems, particularly for the foods that are vital for healthy diets, like fruits, vegetables and nuts," says Christina Grozinger, Publius Vergilius Maro Professor of Entomology and director of the Center for Pollinator Research at Penn State."This detailed map of pollination needs and pollinator deficits helps identify regions where resources could be provided to improve pollinator habitat, as well as other regions where local land use practices are supporting both agriculture and healthy pollinator populations. Those places could serve as models for sustainable agriculture and pollinator conservation practices."The research was funded by the National Science Foundation.
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Agriculture & Food
| 2,021 |
February 3, 2021
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https://www.sciencedaily.com/releases/2021/02/210203144537.htm
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Fungus that eats fungus could help coffee farmers
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Coffee rust is a parasitic fungus and a big problem for coffee growers around the world. A study in the birthplace of coffee -- Ethiopia -- shows that another fungus seems to have the capacity to supress the rust outbreaks in this landscape.
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"Coffee leaf rust is a fungal disease that is a problem for coffee growers around the world, especially on Arabica coffee, which accounts for three quarters of global coffee production and has the finest cup quality. There is a need to learn more about natural solutions instead of just applying pesticides," says Kristoffer Hylander, professor at the Department of Ecology, Environment and Plant Sciences (DEEP) at Stockholm University.Coffee leaf rust is caused by a parasitic fungus that attacks the leaves of the coffee shrub. In some areas it has previously been known to have a potential natural enemy -- a hyperparasitic fungus that grows on top of the rust. However, very little is known about its biology and to what extent it could suppress the rust. This is the first study on the interaction between the rust and its hyperparasite in Ethiopia, the birthplace of Arabica coffee. The coffee plant, the rust and its hyperparasite may have coevolved in Ethiopia for a long time.Coffee leaf rust generally increases in abundance from the rainy to the dry season. However, it seems like this increase is reduced in places where the hyperparasite is common:"This is an indication that the hyperparasite may have the potential to reduce outbreaks of the rust in areas where both the rust and the hyperparasite exist together," says Ayco Tack, associate professor at the Department of Ecology, Environment and Plant Sciences (DEEP) at Stockholm University.It seems like the rust and the hyperparasite thrive in slightly different environments, with the rust adapting well in less humid places and the hyperparasite favouring slightly more humid places such as coffee farms with more shade trees."This could be a win-win situation. By increasing the tree cover in coffee plantations with native shade tree species that maintain their leaves during the dry season, we could perhaps benefit both biodiversity and the hyperparasite," says Kristoffer Hylander, professor at the Department of Ecology, Environment and Plant Sciences (DEEP) at Stockholm University.The authors did not investigate whether the presence of the hyperparasite could lead to better coffee yields, via its effect on rust. The hyperparasite might reduce leaf drop associated with severe rust infection, thus reducing the expected indirect negative effect of the rust on coffee yields."This would be one of the next important steps in this research, since yield of coffee (or revenue) matters most for the smallholder coffee farmers. Interestingly, Ethiopia does not seem to have as big a problem with coffee leaf rust as other coffee-producing countries -- and it would be interesting to find out if the hyperparasite may be an explanation for this difference. It is also important to note that the effect of coffee leaf rust in this landscape might change with the current global climate change," says Beyene Zewdie, who recently defended his thesis on the ecology of coffee diseases in Ethiopia at the Department of Ecology, Environment and Plant Sciences (DEEP) at Stockholm University.More detailed experimental studies are needed to explore the relationships between the rust and the hyperparasite. This could enable coffee growers to utilize the hyperparasite as a biological control for the coffee leaf rust in more intensively managed plantations where the rust epidemics are highly problematic.
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Agriculture & Food
| 2,021 |
February 3, 2021
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https://www.sciencedaily.com/releases/2021/02/210203123415.htm
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Flower diversity may mitigate insecticide effects on wild bees
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A higher diversity of flowering plants increases the breeding success of wild bees and may help compensate for the negative effects of insecticides. This is what researchers from the Universities of Göttingen and Hohenheim, as well as the Julius Kühn Institute, have found in a large-scale experimental study. The results have been published in the scientific journal
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In their experiment, the researchers investigated how successfully the wild bee Osmia bicornis (red mason bee) reproduced. Red mason bees are important for both ecological and economic reasons. The wild bees were experimentally kept in more than 50 large enclosure cages with flower mixtures of varying wild plant diversity and insecticide-treated oilseed rape. Subsequently, the reproductive success of the wild bees, as measured by the number of their brood cells and emerged offspring, was investigated over several months.The research team found that the number of cells that the wild bees created for their offspring where species-rich flowering mixtures were available was twice that of wild bees where only oilseed rape was available. The reproductive success of the wild bees, which have to supply their offspring with pollen and nectar, increased both in cages with a large diversity of flowering plants and where there were particularly important plant species. In contrast, if oilseed rape treated with clothianidin (from the neonicotinoid class of insecticides), was available to the bees, this had a negative effect on their reproductive success. However, this negative effect of the insecticide only occurred in cages with oilseed rape monocultures, which suggests that such effects can be mitigated by alternative food resources from species-rich flowering mixtures.The study shows that both the diversity of flowering plants and exposure to insecticides significantly influence the reproductive success of wild bees, and shows that a high diversity of flowering plants could compensate for the negative effects of insecticides. "One possible explanation is that bee larvae benefit from additional nutrients, and are exposed to fewer insecticides, when the pollen of other plant species besides oilseed rape is available to them," explains Felix Klaus, first author of the study and PhD student in the Agroecology Group at Göttingen University. "Our results emphasise the important role of species-rich resources of flowers for wild bees," adds Professor Ingo Grass, head of the Department of Ecology of Tropical Agricultural Systems at the University of Hohenheim. "If sufficiently diverse flowers are available in the agricultural landscape, this could counteract the negative effects of monocultures and insecticides," says Professor Teja Tscharntke, Head of the Agroecology Group at Göttingen University.
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Agriculture & Food
| 2,021 |
February 2, 2021
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https://www.sciencedaily.com/releases/2021/02/210202164522.htm
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Study challenges ecology's 'Field of Dreams' hypothesis
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If you build it, they might not come. That's the key finding of a new study on habitat restoration practices that challenges a commonly accepted principle in ecology.
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The study tested the "Field of Dreams" hypothesis, which predicts that restoring plant biodiversity will lead to recovery of animal biodiversity. The prediction, which often guides restoration practices, is infrequently tested because restoration studies typically measure plant or animal biodiversity, but rarely both, said lead author Pete Guiden, a post-doctoral researcher at Northern Illinois University.Guiden and NIU colleagues studied 17 research plots of restored tallgrass prairie, measuring biodiversity in four animal communities -- snakes, small mammals and ground and dung beetles. "We wanted to know if the most diverse animal communities were found in the most diverse plant communities, or if something else is responsible for patterns of animal biodiversity," he said.While the scientists did find some positive connections between plant and animal biodiversity, the gains weren't nearly as strong as benefits derived from implementation of restoration management strategies."We found that the effects of management strategies like controlled burns and bison reintroduction on animal communities were six times stronger on average than the effects of plant biodiversity," Guiden said."The most important effects of restoration on animal biodiversity had little to do with plant community biodiversity," he added. "So management practices focused on restoring plants might be insufficient to also restore animals."The study is published in the Co-authors include NIU professors Holly Jones (biology, environmental studies) and Richard King (biology); NIU post-doctoral fellow John Vanek; NIU graduate student Erin Rowland; former NIU students Ryan Blackburn, Anna Farrell, Jessica Fliginger, Sheryl C. Hosler, Melissa Nelson and Kirstie Savage; and former NIU professor Nicholas Barber of San Diego State University.This is an important study," said Jones, whose Evidence-based Restoration Laboratory at NIU carried out the research. "With Earth's biodiversity rapidly disappearing, ecological restoration has emerged as an important strategy to slow or reverse biodiversity losses. Critical tests of the Field of Dreams and other hypotheses are needed to improve restoration science and ensure we get the most bang for our buck."The study results were a surprise to the authors, who had predicted that plant biodiversity would have stronger effects on animal biodiversity than management strategies."We expected plant biodiversity to be important because having more plant species allows animals to split up food resources or habitat," Guiden said. "However, the strong effects of land management on animal biodiversity highlight the important role of people in shaping the quantity or quality of habitat, especially through disturbance regimes used in restoration."The scientists' work was conducted at Nachusa Grasslands, a 3,800-acre nature preserve in Franklin Grove, Illinois, managed by The Nature Conservancy. Since 1986, Nachusa crew members and volunteers have been reconnecting remnant prairie, woodlands and wetlands through habitat restoration to create one of the largest and most biologically diverse grasslands in Illinois. Tallgrass prairie is one of the most globally imperiled ecosystems."While Illinois is known as the Prairie State, 99.9 percent of its prairie has been lost to agriculture and development," Jones said. "Nachusa Grasslands is an incredible success story. What The Nature Conservancy has done is show us we can restore ecosystems. What was once rows of corn is now a really high-functioning prairie that also serves as a living laboratory for restoration scientists."The 17 research sites studied measured 60-by-60 meters and had restoration ages spanning three to 32 years. Each site experienced a unique controlled-burn history, and bison had been reintroduced to eight of the sites between 2014 and 2015. For Nachusa Grasslands, fire and bison-grazing are key management practices that are components of healthy prairies and together can increase plant and animal biodiversity.By simultaneously measuring plant and animal responses to restoration disturbances, the scientists were able to tease out and compare management-driven and plant-driven effects.Guiden said each animal community studied differed considerably in its specific responses to restoration. In fact, the study found that restoration can simultaneously have positive and negative effects on biodiversity through different pathways, which may help reconcile why there can be variation in restoration outcomes.For example, in older restorations, high diversity among plants resulted in a decrease in a specific diversity measure for dung beetles, likely because key resources became more difficult to find. On the other hand, older restorations also had soil conditions that provided high quality habitat for a wide range of other species.Guiden also noted that the animals studied in this research project are decomposers (dung beetles), omnivores (small mammals) or carnivores (snakes, ground beetles). "Animal communities composed of herbivores, particularly species highly specialized on specific prairie plants, may show stronger relationships to plant diversity," he said.Ecosystems are difficult to restore because they represent such highly intricate webs of species' interactions with each other and their environments, Jones said."Our study shows that it's critical to define restoration goals before projects get off the ground and to measure progress," she said. "This will help ensure the restoration is eliciting the desired responses."Perhaps more importantly, our study shows these active restoration techniques of introducing megaherbivores like bison, which were near extinction last century, and fire regimes that Indigenous people used to set to prairies, are absolutely critical components to recreating those complex webs of species and interactions. Seeding alone gets us started, but extra management super charges the animal communities that are critical to maintaining healthy prairies."
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Agriculture & Food
| 2,021 |
February 1, 2021
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https://www.sciencedaily.com/releases/2021/02/210201113602.htm
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Human activity forces animals to move 70% further to survive
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For the first time, scientists have calculated the global impact of human activity on animal movement, revealing widespread impacts that threaten species survival and biodiversity.
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While it has been shown that activities such as logging and urbanisation can have big impacts on wildlife, the study by scientists at the University of Sydney and Deakin University in Australia shows that episodic events such as hunting, military activity and recreation can trigger even bigger changes in animal behaviour."It is vital we understand the scale of impact that humans have on other animal species," said lead author Dr Tim Doherty, a wildlife ecologist at the University of Sydney. "The consequences of changed animal movement can be profound and lead to reduced animal fitness, lower chances of survival, reduced reproductive rates, genetic isolation and even local extinction."The study is published today in Key findings include:- Episodic human activities such as hunting, aircraft use, military activity and recreation can cause much greater increases in movement distances than habitat modification such as logging or agriculture- Episodic disturbances force a 35 percent overall change in movement (increase and decrease); habitat modifications force a 12 percent change- Increases in animal movement averaged 70 percent- Decreases in animal movement averaged 37 percentThe study points to a global restructuring of animal movements caused by human disturbance, with potentially profound impacts on animal populations, species and ecosystem processes."Movement is critical to animal survival, but it can be disrupted by human disturbances," Dr Doherty said. "Animals adopt behavioural mechanisms to adjust to human activity, such as by fleeing or avoiding humans, travelling further to find food or mates; or finding new shelter to avoid humans or predators."In some cases, human activity forced a reduction in animal movement, the study found, because of increased access to food in human locations, reduced ability to move from modified habitat or restrictions to movement by physical barriers."As well as the direct impact on animal species, there are knock-on effects," Dr Doherty said. "Animal movement is linked to important ecological processes such as pollination, seed dispersal and soil turnover, so disrupted animal movement can have negative impacts throughout ecosystems."Dr Doherty, who started this research at Deakin University before moving to the University of Sydney, has said the findings have important policy implications for managing animal biodiversity."In marine environments and landscapes relatively untouched by human impact, it is important that habitat modification is avoided," said Dr Doherty from the School of Life and Environmental Sciences in the Faculty of Science."This could involve strengthening and supporting existing protected areas and securing more areas of wilderness for legal protection."The study says it might be easier to reduce the impacts of episodic disturbances by carefully managing certain activities, such as hunting and tourism, in wilderness areas, especially during animal breeding periods."Where habitat modification is unavoidable, we recommend that knowledge of animal movement behaviour informs landscape design and management to ensure animal movement is secured," Dr Doherty said.He said that reducing negative impacts of human activity on animal movement will be vital for securing biodiversity in an increasingly human-dominated world."Further research is needed to better understand the impact of habitat modification on animal movement in rapidly developing parts of the world," Dr Doherty said.The research compiled and analysed 208 separate studies on 167 animal species over 39 years to assess how human disturbance influences animal movement. In more than one-third of cases, animals were forced into changes that saw movement increase by more than 50 percent.Species covered in the study range from the 0.05 gram sleepy orange butterfly to the more than 2000 kilogram great white shark. There were 37 bird species, 77 mammal species, 17 reptile species, 11 amphibian species, 13 fish species and 12 arthropod (insect) species covered.
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Agriculture & Food
| 2,021 |
February 1, 2021
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https://www.sciencedaily.com/releases/2021/02/210201101534.htm
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Improved model estimates impact of ozone on soy crops
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The impact of ozone on soybean production can be predicted more accurately thanks to improvements to a computer modelling system.
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Surface ozone is a pollutant that affects plant growth by entering leaves and reducing the rate of photosynthesis, and rising ozone levels could severely limit production of crops including soy.Being able to estimate this damage on soybean production using a "climate-vegetation model" is vital for predicting global and regional soy yields in the future.This study uses results from a field experiment in the USA, which found that a normal ozone level of 10ppm/h (AOT40) could reduce soybean yield by 10%.At extreme ozone levels -- comparable to those observed on very polluted days in some parts of the world -- soybean production fell to less than half the amount grown in unpolluted air."Currently, ozone concentrations are projected to increase globally, which could have a significant impact on agriculture and food security," said Dr Felix Leung, of the University of Exeter."Economic loss from ozone damage to crops is already estimated at $14 billion to $26 billion USD."Policy decisions -- such as the promotion of electric vehicles over diesel and petrol cars -- are urgently required to limit surface ozone levels."Ozone in the stratosphere protect us from harmful ultra violet radiation, but in the lower atmosphere, the troposphere, it is toxic to humans and plants.As well as limiting photosynthesis -- and therefore reducing carbon storage by plants -- it is also a greenhouse gas, and is toxic to humans and animals.Ozone is caused by a combination of pollutants including nitrogen oxide, which mostly comes from vehicle and factory emissions.The climate-vegetation computer model used in this study is called JULES.It was developed by a wide community of UK researchers, coordinated by the Met Office and Centre for Ecology and Hydrology."The newly calibrated version of JULES will be applied regionally and globally in future JULES simulations," said Dr Leung."This study helps to build a state-of-the-art impact assessment model and contribute to a more complete understanding of the impacts of climate change on food production."The research team included Dr Karina Williams and Dr Andy Wiltshire, who were both among Met Office staff who took joint positions at the Global Systems Institute at the University of Exeter last year.The study was funded by the Natural Environment Research Council (NERC).
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Agriculture & Food
| 2,021 |
January 27, 2021
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https://www.sciencedaily.com/releases/2021/01/210127171854.htm
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Putting bugs on the menu, safely
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The thought of eating insects is stomach turning for many, but new Edith Cowan University (ECU) research is shedding light on allergy causing proteins which could pose serious health risks for those suffering from shellfish allergy.
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The research, published in the journal The project was led by Professor Michelle Colgrave from ECU's School of Science and the CSIRO.Professor Colgrave said crickets and other insects could be the key to feeding for the estimated 9.7 billion people on Earth in 2050."More than 2 billion people around the world already eat insects on a daily basis and they could be a sustainable solution, providing protein that complements traditional animal-based protein sources," she said."Crickets are high in protein, nutrient dense and considered environmentally friendly."Numerous studies have shown eating insects provide benefits to gut health, lowering blood pressure while being high in antioxidants."While insects show promise as an alternative protein source, and are identified by Agrifutures as a high potential emerging industry, their allergenic properties are a concern.As the world searches for novel and more sustainable forms of food, consideration must also be paid to those with allergenic properties and that is where Professor Colgrave's research fits in."This research showed a significant overlap in allergenic proteins found in cricket food products and those found in shellfish like crabs and prawns," she said."That's because crickets, mealworms and other insects are closely related to crustaceans."Shellfish allergies affect up to two per cent of people globally, but varies according to age and region, and there's a good chance that people allergic to shellfish will also react to insects."Being an allergen does not prevent insects being used as a food source, however it does mean that insect-based foods need to be tested and labelled correctly to ensure people with allergies don't unwittingly eat them.The research team from ECU, CSIRO, James Cook University and Singapore's National Agency for Science Technology and Research compared proteins from roasted whole crickets and cricket powder products to known allergens.Their results can now be used to detect cricket-derived allergens in food products that can support allergen labelling and safe food manufacture.'Protein extraction protocols for optimal proteome measurement and arginine kinase quantitation from cricket Acheta domesticus for food safety assessment' was published in
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Agriculture & Food
| 2,021 |
January 27, 2021
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https://www.sciencedaily.com/releases/2021/01/210127085245.htm
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Detecting trace amounts of multiple classes of antibiotics in foods
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Widespread use of antibiotics in human healthcare and livestock husbandry has led to trace amounts of the drugs ending up in food products. Long-term consumption could cause health problems, but it's been difficult to analyze more than a few antibiotics at a time because they have different chemical properties. Now, researchers reporting in ACS'
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Antibiotics can be present at trace amounts in meat, eggs and milk if the animals aren't withdrawn from the drugs for a sufficient period of time before the products are collected. Also, antibiotics can accumulate in cereals, vegetables and fruits from manure fertilizer or treated wastewater applied to crops. Consuming these foods over a long period of time could lead to increased antibiotic resistance of bacterial pathogens or to an imbalance in the gut microbiome. However, most previous monitoring methods for antibiotics in foods have been limited to a few compounds at a time, usually within a single class of antibiotics with similar structures and chemical properties. Other methods have analyzed multiple antibiotics in only a single food type, such as eggs or milk. Yujie Ben and colleagues wanted to develop a time- and cost-effective method that could detect a wide range of antibiotics in different types of foods.The researchers added trace amounts of 81 antibiotics from seven categories to vegetable samples and tested 20 different methods for extracting the drugs from the food. Only one extraction process, which involved treating freeze-dried, homogenized food samples with an acidified acetonitrile solution and a mixture of magnesium sulfate and sodium acetate, allowed the researchers to isolate 77 of the antibiotics. After establishing that their method was sensitive and accurate with spiked antibiotics in several foods, the team applied it to store-bought samples of wheat flour, mutton, eggs, milk, cabbage and bananas, detecting a total of 10 antibiotics. One of them, roxithromycin, was detected at trace amounts in all six food types. The new method should help with understanding, monitoring and regulating antibiotic levels in foods, the researchers say.
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Agriculture & Food
| 2,021 |
January 27, 2021
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https://www.sciencedaily.com/releases/2021/01/210127085239.htm
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Making wheat and peanuts less allergenic
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The United States Department of Agriculture identifies a group of "big eight" foods that causes 90% of food allergies. Among these foods are wheat and peanuts.
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Sachin Rustgi, a member of the Crop Science Society of America, studies how we can use breeding to develop less allergenic varieties of these foods. Rustgi recently presented his research at the virtual 2020 ASA-CSSA-SSSA Annual Meeting.Allergic reactions caused by wheat and peanuts can be prevented by avoiding these foods, of course. "While that sounds simple, it is difficult in practice," says Rustgi.Avoiding wheat and peanuts means losing out on healthy food options. These two foods are nutritional powerhouses.Wheat is a great source of energy, fiber, and vitamins. Peanuts provide proteins, good fats, vitamins and minerals."People with food allergies can try hard to avoid the foods, but accidental exposure to an allergen is also possible," says Rustgi. Allergen exposure can lead to hospitalization, especially for people with peanut allergies."For others, avoiding wheat and peanuts is not easy due to geographical, cultural, or economic reasons," explains Rustgi.Rustgi and his colleagues are using plant breeding and genetic engineering to develop less allergenic varieties of wheat and peanuts. Their goal is to increase food options for people with allergies.For wheat, researchers focus on a group of proteins, called gluten.The gluten in bread flour makes dough elastic. Gluten also contributes to the chewy texture of bread.But gluten can cause an immune reaction for individuals with Celiac disease. In addition, others experience non-celiac gluten sensitivity, leading to a variety of adverse symptoms.Researchers have been trying to breed varieties of wheat with lower gluten content. The challenge, in part, lies in the complicated nature of gluten genetics. The information needed to make gluten is embedded in the DNA in wheat cells.But gluten isn't a single protein -- it's a group of many different proteins. The instructions cells needed to make the individual gluten proteins are contained within different genes.In wheat, these gluten genes are distributed all over a cell's DNA. Since so many portions of the DNA play a role in creating gluten, it is difficult for plant breeders to breed wheat varieties with lower gluten levels."When we started this research, a major question was whether it would be possible to work on a characteristic controlled by so many genes," says Rustgi.For peanuts, the situation is similar. Peanuts contain 16 different proteins recognized as allergens."Not all peanut proteins are equally allergenic," says Rustgi. Four proteins trigger an allergic reaction in more than half of peanut sensitive individuals.Like the gluten genes in wheat, the peanut allergen genes are spread throughout the peanut DNA."Affecting this many targets is not an easy task, even with current technology," says Rustgi.Rustgi and the research team are testing many varieties of wheat and peanuts to find ones that are naturally less allergenic than others.These low-allergenic varieties can be bred with crop varieties that have desirable traits, such as high yields or pest resistance. The goal is to develop low-allergenic wheat that can be grown commercially.In addition to traditional breeding efforts, Rustgi is also using genetic engineering to reduce allergenic proteins in wheat and peanuts.For example, a technology called CRISPR allows scientists to make very precise changes to a cell's DNA.Rustgi is using CRISPR to target gluten genes in wheat. Recent improvements in CRISPR technology allow researchers to target many genes at once.Genes targeted by CRISPR are changed or mutated. This means that cells can no longer 'read' these genes to make the specific proteins."Disrupting the gluten genes in wheat could yield wheat with significantly lower levels of gluten. A similar approach would work in peanuts," says Rustgi.Other approaches include understanding how gluten production is regulated in wheat cells. As it turns out, one protein serves as a 'master regulator' for many gluten genes.That's important because disrupting this master regulator could lead to reduced amounts of gluten in wheat. Targeting a single gene is much easier than trying to disrupt the several gluten genes."Wheat and peanuts are the major sources of proteins to many, especially those living in resource-deprived conditions," says Rustgi. "Finding affordable ways to make wheat and peanuts available for all is very important."Developing wheat and peanuts with reduced allergen levels is a key step toward this goal."These crops will also reduce accidental exposure to allergens," says Rustgi. "Also, they would limit the severity of reactions if exposure did happen."
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Agriculture & Food
| 2,021 |
January 26, 2021
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https://www.sciencedaily.com/releases/2021/01/210126140052.htm
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Building a corn cob; cell by cell, gene by gene
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Corn hasn't always been the sweet, juicy delight that we know today. And, without adapting to a rapidly changing climate, it is at risk of losing its place as a food staple. Putting together a plant is a genetic puzzle, with hundreds of genes working together as it grows. Cold Spring Harbor Laboratory (CSHL) Professor David Jackson worked with Associate Professor Jesse Gillis to study genes involved in corn development. Their teams analyzed thousands of individual cells that make up the developing corn ear. They created the first anatomical map that shows where and when important genes turn on and off during key steps in development. This map is an important tool for growing better crops.
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Humans have been breeding corn to make it more useful for thousands of years. Jackson says:"Ten thousand years ago, corn did not exist, right? There was a wild plant called teosinte. Teosinte itself only makes about 10 seeds. It makes these really tiny ears that don't give much nutrition. In fact, the seeds they make are so tough that they would break your teeth if you try to eat them anyway."The secret to more and bigger kernels is found by looking at baby ears of corn 1-10 mm long. The scientists used a technique that allowed them to track every cell. They gave each cell a genetic ID tag, called a barcode. Xiaosa Xu, the lead author of the study, compares it to building a building. Xu says:"We are able to use this single-cell RNA-seq technology to identify which block is what kind of identity: if this block is from our kitchen room or that block is from our bedroom."The scientists took corn plants at early stages of development, broke them into individual cells, barcoded them, and then saw what genes were turned on in each one. Jackson notes, "in the past we haven't been able to separate the cells and figure out the genetic information that's specific to each cell. So that's really, what's new and exciting." They could then reconstruct an anatomical map to pinpoint where genes important for corn development were used.Crops are still evolving. Jackson looks forward to developing different kinds of corn plants to fill new ecological niches. He also hopes this new technique will help other plant geneticists in their efforts to sustainably improve crop yields.
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Agriculture & Food
| 2,021 |
January 25, 2021
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https://www.sciencedaily.com/releases/2021/01/210125144542.htm
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The surprises of color evolution
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Nature is full of colour. For flowers, displaying colour is primarily a means to attract pollinators. Insects use their colour vision not only to locate the right flowers to feed on but also to find mates. The evolutionary interaction between insects and plants has created complex dependencies that can have surprising outcomes. Casper van der Kooi, a biologist at the University of Groningen, uses an interdisciplinary approach to analyse the interaction between pollinators and flowers. In January, he was the first author of two review articles on this topic.
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Bees and other insects visit flowers to feed on nectar and pollen. In exchange for these goodies, they assist the reproduction of these plants by pollinating their flowers. That is the simple and slightly romantic view of pollination. The reality, however, is full of deception, chemical warfare and biomechanical trickery. 'The combination of chemistry and physics with evolutionary biology has broadened our view of pollination,' says Van der Kooi.He is the first author of a review article on the evolution of colour vision in insects, which was published in the January 2021 volume of Annual Review of Entomology, and of a second review on the 'arms race' between plants and pollinators, which appeared on 25 January in 'For many insect families, we know very little about how they see colours,' says Van der Kooi. Bees have been studied in great detail but much less is known about colour vision in flies, even though many of their families, such as hoverflies, are very important pollinators. 'They are difficult to study and to keep in the lab and the anatomy of their eyes is more complicated,' explains Van der Kooi. 'Furthermore, some long-standing ideas on fly vision have recently been overturned.'Van der Kooi and his co-authors tabulated which wavelengths can be seen by different insect species. 'Basically, insect colour vision occurs at wavelengths between 300 and 700 nanometres. Most photoreceptors in insect eyes detect ultraviolet, blue and green light but there is great diversity.' Insects evolved colour vision before the first flowers appeared. 'The pigments in flowers appear to be fine-tuned to be visible to pollinators. But of course, insects have subsequently co-evolved.'Apart from colour, plants use scent to attract insects to the food that they provide. As production of nectar and pollen is costly, plants need to protect themselves from robbers, which eat the food but do not pollinate the flowers. This is the topic of the second review paper. 'This paper shows a huge diversity in the relationship between plants and pollinators, from real mutualism to outright abuse.' Some plants do not provide any food at all. 'Others have pollen or nectar that is toxic to most bee species. Only specific species can actually digest this food.'Pollinators also have their own agenda. 'One particular plant is pollinated by moths in early spring. The moth also lays eggs on the plant and later in the year, the caterpillars will eat parts of it. Around that time, the main pollinators for this plant are flies.' This is one example of the complex relationship between plants and pollinators. 'There can be seasonal differences but the relationship can also be different in different locations -- there is variation in time and space and through different biological interactions,' says Van der Kooi.The review focuses on different aspects of the complex relationship using views from chemical biology (e.g. the nutrient content of nectar or pollen), biomechanics (e.g. the barriers that flowers use to ward off unwanted insects or to make sure that pollen are dispersed by them) and sensory biology (e.g. the ways in which insects detect and recognize flowers).Some plants, for example, many species in the potato family, have evolved the method of 'buzz-pollination', where the pollen are stored in tubes and insects need to vibrate on the flowers to release them. 'Honeybees, flies and butterflies cannot get to them but other bees such as bumblebees can shake the pollen free using their strong flight muscles.' The stiffness of the tubes, the stickiness of the pollen and the vibration frequency of the buzzing bees all play a part in this process. 'You really need tools from physics to understand their relationship.' The interdisciplinary study of insect-plant interactions is what Van der Kooi loves. He started his career using optics techniques. 'That is in part because I really like physics. But every new approach will show us new aspects of this complex relationship.'A recent development in the field is the realization that plants are different in different geographic locations. 'A cornflower in the Netherlands is not necessarily the same as a cornflower in Italy. For example, the chemical composition of the pollen or the nectar may be different, which affects the interaction with insects.'This has serious ramifications for attempts to boost insect numbers by creating insect havens, explains Van der Kooi: 'Sometimes, the seed mixtures for flowering strips are not sourced locally but from other countries. In that case, there may be a mismatch with the local insects, which may even harm insect numbers.' Insect havens are therefore best created using local seeds.Both review articles stress how complicated the relationship between plants and pollinators can be. So why do plants bother? Why are they not all using wind dispersal of their pollen? 'Those are good questions,' says Van der Kooi. 'The efficiency of wind pollination is low but that is also true for animal pollination. Yet, roughly 90 per cent of plant species use the latter method, so it is a huge success.' But even this is complicated: 'Grasses use wind pollination, and in some ways, they are successful groups too. Like nearly everything in biology, the answer so often is "it depends..."'
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Agriculture & Food
| 2,021 |
January 22, 2021
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https://www.sciencedaily.com/releases/2021/01/210122112320.htm
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Plant genome editing expanded with newly engineered variant of CRISPR-Cas9
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Alongside Dennis vanEngelsdorp, associate professor at the University of Maryland (UMD) in Entomology named for the fifth year in a row for his work in honey bee and pollinator health, Yiping Qi, associate professor in Plant Science, represented the College of Agriculture & Natural Resources on the Web of Science 2020 list of Highly Cited Researchers for the first time. This list includes influential scientists based on the impact of their academic publications over the course of the year. In addition to this honor, Qi is already making waves in 2021 with a new high-profile publication in
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"It is an honor, an encouragement, and a recognition of my contribution to the science community," says Qi of his distinction as a 2020 Web of Science Highly Cited Researcher. "But we are not just making contributions to the academic literature. In my lab, we are constantly pushing new tools for improved gene editing out to scientists to make an impact."With SpRY, Qi is especially excited for the limitless possibilities it opens up for genome editing in plants and crops. "We have largely overcome the major bottleneck in plant genome editing, which is the targeting scope restrictions associated with CRISPR-Cas9. With this new toolbox, we pretty much removed this restriction, and we can target almost anywhere in the plant genome."The original CRISPR-Cas9 tool that kicked off the gene editing craze was tied to targeting a specific short sequence of DNA known as a PAM sequence. The short sequence is what the CRISPR systems typically use to identify where to make their molecular cuts in DNA. However, the new SpRY variant introduced by Qi can move beyond these traditional PAM sequences in ways that was never possible before."This unleashes the full potential of CRISPR-Cas9 genome editing for plant genetics and crop improvement," says an excited Qi. "Researchers will now be able to edit anywhere within their favorable genes, without questioning whether the sites are editable or not. The new tools make genome editing more powerful, more accessible, and more versatile so that many of the editing outcomes which were previously hard to achieve can now be all realized."According to Qi, this will have a major impact on translational research in the gene editing field, as well as on crop breeding as a whole. "This new CRISPR-Cas9 technology will play an important role in food security, nutrition, and safety. CRISPR tools are already widely used for introducing tailored mutations into crops for enhanced yield, nutrition, biotic and abiotic stress resistance, and more. With this new tool in the toolbox, we can speed up evolution and the agricultural revolution. I expect many plant biologists and breeders will use the toolbox in different crops. The list of potential applications of this new toolbox is endless."
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Agriculture & Food
| 2,021 |
January 22, 2021
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https://www.sciencedaily.com/releases/2021/01/210122112254.htm
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Flowery diets help predatory insects help farmers keep pests in check
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Good news for the green transition: Flowery diets help predatory insects help farmers keep pests in check Predatory insects have been shown to live longer when they have access to nectar and pollen, according to a new study by researchers at the University of Copenhagen. Thus, flowers don't just benefit insects, they help farmers farm sustainably. Predatory insects are skilled pest controllers whose hunting reduces the need for agricultural pesticides.
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Until now, it was believed that predatory insects needed prey to survive. But in a systematic review conducted at the University of Copenhagen's Department of Plant and Environmental Sciences, researchers collected, compared and analyzed data from studies around the world to conclude that most predators benefit greatly from flowers, and can even survive for extended periods of time on nectar and pollen alone. Thus, farmers can promote a consistent production of natural enemies to defeat pests by incorporating flowering strips and flowering margins in their fields:"By planting flowering margins and strips alongside fields, one can ensure an ever-abundant supply of predatory insects such as hoverflies, lacewings, minute pirate bugs, phytoseiid mites and two-spot ladybugs. Pollen and nectar are supplements that beneficial insects can survive on when pests aren't around. And, the plants in margins and strips provide many other types of insects for to prey on as well. By planting a wide variety of flowers that bloom both early and late in the season, one can ensure for an optimal effect that ensures the survival of predators throughout the growing season," says Associate Professor Lene Sigsgaard of the Department of Plant and Environmental Sciences. She adds:"This is good news for the green transition, as effective pest control can help reduce the use of agricultural pesticides. On top of the that, the presence of more flowers imroves pollination and biodiversity, as they attract more insects and pollinators into fields."The researchers underscore that in order for predatory insects to access flower nectar, easily accessible open flowers need to be planted, as predatory insects aren't equipped with the long feeding tubes that bees have. Examples of open and beneficial flowers are wild carrot, ox eye daisy, dill and dandelion.Food from flowers boosts energy for predators. Specifically, the researchers found that across all predatory insects, females survive 2.2 times longer with access to flowers, and males 1.7 times longer, compared to insects that only have access to water, but no flowers.Still, not all predatory insects and flowers are the same. Some predators manage to lay eggs with access to flowers alone. Of the 17 predatory insect species tested with more than one species of flowers, nine -- including lacewings, two-spot ladybugs and minute pirate bugs -- lived significantly longer with flowers. The lifespans of the remaining 8 species, including a predatory mite, were not significantly longer.There are differences among flowers as well. With buckwheat, which has open flowers and is a cultivated crop, predator insects lived an average of 8.6 times longer than on water alone. Mallow, yarrow and ox eye daisy are also highly valuable flowers for predatory insects, while lotus and viper's bugloss, due to their deeper tubes, are less helpful.'It's quite an elixir of life. Wisely planted flowers can contribute to robust crop production because predatory insects will live longer and better," says Lene Sigsgaard, who continues:"It pays to design tomorrow's agriculture so as to accommodate wild flowering plants alongside fields. For the greatest impact, this needs to be done on an informed basis, which is why we are looking at how to design mixed flowering strips and flowering margins that benefit both predatory insects and pollinators. This will reduce the need for other forms of pest control while supporting biodiversity," says Lene Sigsgaard.The researchers recommend native, perennial flowers to create permanent habitats for predatory insects, places where they can winter as well. It is also important to have a wide variety of species that bloom during different seasons and benefit different insects. The researchers work with 30-40 different native species in the field, including grasses, which help make flower strips more robust.The researchers are continuing to generate more knowledge about which flowers and flower combinations are particularly beneficial for insect life in general, and more specifically, for beneficial insects and their contribution to biological pest control and pollination.
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Agriculture & Food
| 2,021 |
January 22, 2021
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https://www.sciencedaily.com/releases/2021/01/210122112252.htm
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Fungi strengthen plants to fend off aphids
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Researchers at the University of Copenhagen have demonstrated that unique fungi strengthen the "immune systems" of wheat and bean plants against aphids. Fungi enter and influence the amount of a plant's own defences, resulting in fewer aphids. The results could serve to reduce agricultural insecticide use and bring Denmark a step further along the path towards its green transition.
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Certain fungi are able to establish a close rapport with plants that results in fewer insect infestations and thereby less damage to crops. Until now, it was unclear how these fungi could be used to reduce insect infestations."In order for us to really use fungi to control agricultural pests in the future, we need to understand the mechanisms and processes behind their activity. So, it's very exciting that we have managed to advance a step closer," says Associate Professor Nicolai Vitt Meyling of UCPH's Department of Plant and Environmental Sciences.The researchers studied three types of fungi to compare their effects against aphid infestations on wheat and bean plants:"It turned out that two of these fungi were able to effectively reduce aphid infestations by establishing themselves in plant roots and tissues. By combining greenhouse-based experiments with advanced chemical analyses, we can see that the fungi cause plants to increase production of their own natural defences, thus strengthening plant "immune systems." This translates into fewer aphids, which would otherwise weaken a plant," says Nicolai Vitt Meyling, who explains:"When aphids suck up plant sap, plants lose energy, to the detriment of their root networks and overall growth. However, when fungi-treated plants were attacked by aphids, they were able to compensate by increasing root growth, so that they didn't lose growth potential. Plants left untreated with the fungi couldn't compensate for the attack," says Nicolai Vitt Meyling.The researchers "treated" wheat and bean plants by applying fungal spores to seed, from which the plants were then germinated and cultivated. They then added a few aphids and observed how many more aphids developed over two weeks in the greenhouse. Thereafter, plant leaves underwent chemical analysis in collaboration with researchers from Aarhus University's Department of Agroecology."We see a clear correlation between an increased amount of defence substances in and fewer aphids on the plants treated with two of the fungi. Those plants left untreated with the fungi had lesser amounts of defence substances and more aphids. There is simply a marked upregulation of defence substances in a plant under aphid attack when these specific fungi are present. And, the same treatment produces the same result in both wheat and bean plants," says Nicolai Vitt Meyling.Thus, the researchers could see that the effect is related to the fungi and not the plant species. The same fungi had the same effect in both the wheat and bean plants, despite the two types of plants not being related and expressing different kinds of defence substances.The fungi also have an effect on insects that attack the root systems of plants. And, in combination with other environmentally-friendly cultivation methods, could help to reduce insecticide use in agriculture."The fungi has the potential to reduce the need for insecticides because treated seeds result in fewer aphids in the field. If we can develop a large-scale method of pre-treating seed with Danish seed producers, to coat plant seeds with these fungi before planting, we may hardly need to spray with insecticides," says Nicolai Vitt Meyling, who concludes:"Limiting pesticide use is an important aspect of the green transition. This can be an effective and sustainable contribution towards such a reduction."The next step is to engage in longer term field trials of treated plants. This will allow researchers to gauge the longevity of effects under realistic growing conditions.
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Agriculture & Food
| 2,021 |
January 22, 2021
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https://www.sciencedaily.com/releases/2021/01/210122101950.htm
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New variety of paintbrush lily developed by a novel plant tissue culture technique
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Scientists at Hokkaido University and Chiba University have developed simultaneous triploid and hexaploid varieties of
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In plants, the number of chromosome sets in cells (ploidy) affects a large number of desirable characteristics. In general, the greater the number of chromosome sets, the more like the plant is to have larger flowers, larger fruits, be more disease resistant, and so on. Hence, particularly in agriculture and horticulture, the development of polyploid plants continues to receive much attention.Scientists from Hokkaido University and Chiba University have successfully developed triploid (3 chromosome sets) and hexaploid (6 chromosome sets) plants of the ornamental plant Triploid plants are quite unique among polyploid plants. Their most significant advantage is also their most significant disadvantage: due to the odd number of chromosome sets, the fruits are seedless, which boosts market value but also means that the plants can only be propagated by cuttings, instead of seeds. This disadvantage can be overcome by generating hexaploid plants from triploid plants.Triploid plants are found naturally, albeit in very small numbers. They can be produced by cross-breeding diploid (2 chromosome sets) and tetraploid (4 chromosome sets) plants, or by PTC techniques. The advantage of PTC over cross-breeding is that a wider variety of plants can potentially be generated over a shorter period of time. Additionally, it is far easier to convert triploid plants to hexaploid plants by PTC techniques.The scientists isolated the endosperm of The scientists chose Yoichiro Hoshino is a Professor at the Field Science Center, Hokkaido University. His research focuses on plant breeding of horticultural crops by using biotechnology, and on analysis of the fertilization process in higher plants. He is interested in utilization of plant genetic resources in the Hokkaido area and in developing novel breeding methods.
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Agriculture & Food
| 2,021 |
January 22, 2021
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https://www.sciencedaily.com/releases/2021/01/210122102028.htm
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Making protein 'superfood' from marine algae
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Marine microalgae-based cellular agriculture is a promising new way to sustainably produce plant-based 'meat' and healthy 'superfoods' for the future.
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Researchers at Flinders University's Centre for Marine Bioproducts Development (CMBD) in Australia are responding to growing interest from consumers looking for healthier, more environmentally friendly, sustainable and ethical alternatives to animal proteins.Marine microalgae, single-cell photosynthetic organisms from the ocean could be the solution to the world's meat protein shortage, says CMBD director Flinders University Professor Wei Zhang, who is also co-leading a bid to establish a national Marine Bioproducts Cooperative Research Centre (MB-CRC) in Australia.The CRC's mission is to find ways to develop the third-generation of Australian high-value marine bioindustry (as opposed to the first-generation of fisheries and the second-generation of aquaculture) and transform Australia's emerging marine bioproducts sector into a globally competitive industry.The Centre's focus will be on industry and market-driven innovations to improve both the supply chain and value chain to deliver costs savings, improved production and competitive capacity for Australia to access high value marine bioproducts markets across the globe."Our research spans the entire value chain, from microalgae cultivation and circular advanced biomanufacturing to the development of high-value functional food," Professor Zhang says."Microalgae come in a diverse range of nutritional profiles and advanced cultivation strategies can be developed for tuning microalgae to produce protein-, oil- and carbohydrate-dominant types that can be processed into a broad range of functional foods, including healthy cell patties, chips, pastes, jams and even caviar."Two freshwater microalgal products currently on the market are the high protein Chlorella and Spirulina varieties used in the production of foods such as green pasta, drinks and beverages.Marine species are of significant interest as they do not require scarce freshwater and crop land. Their unique nutritional profiles such as their high DHA and EPA content (long chain omega 3 fatty acids) are essential for infant and brain development and cardiac health.Bioreactors for upscaling upscaled aquatic production of photosynthetic microalgae can also help to combat greenhouse gas emissions and climate change. One 90 x 90 x 210 cm (3 x 3 x 7 ft) bioreactor unit can absorb up to 400 times more carbon dioxide than the same footprint of trees.Using sunlight, certain varieties of microalgae create oxygen and convert carbon dioxide into organic carbon (protein, carbohydrates, pigments, fats and fibres), just like plants, but do not require valuable arable land for their production."They are therefore often called the rainforests of the oceans," says Associate Professor Kirsten Heimann, senior lecturer in biotechnology at Flinders University."Using sunlight, photosynthetic microalgae create oxygen and convert carbon dioxide into organic carbon (protein, carbohydrates, pigments, fats, fibres, and micronutrients), just like plants, but do not require valuable arable land for their production.This means microalgae can be sustainably harvested and converted into eco-friendly superfoods," she says. "Putting one and one together, microalgae and innovative production and processing could help to service the world's booming population and growing demand for sustainable protein production," she says.Along with research into processing techniques, the CMBD team is also investigating the use of waste or harvested seaweed for biodegradable plastics production, another sustainable solution to non-degradable petroleum-based plastics.
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Agriculture & Food
| 2,021 |
January 21, 2021
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https://www.sciencedaily.com/releases/2021/01/210121131851.htm
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Study compares low-fat, plant-based diet to low-carb, animal-based diet
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People on a low-fat, plant-based diet ate fewer daily calories but had higher insulin and blood glucose levels, compared to when they ate a low-carbohydrate, animal-based diet, according to a small but highly controlled study at the National Institutes of Health. Led by researchers at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), the study compared the effects of the two diets on calorie intake, hormone levels, body weight, and more. The findings, published in
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"High-fat foods have been thought to result in excess calorie intake because they have many calories per bite. Alternatively, high-carb foods can cause large swings in blood glucose and insulin that may increase hunger and lead to overeating," said NIDDK Senior Investigator Kevin Hall, Ph.D., the study's lead author. "Our study was designed to determine whether high-carb or high-fat diets result in greater calorie intake."The researchers housed 20 adults without diabetes for four continuous weeks in the NIH Clinical Center's Metabolic Clinical Research Unit. The participants, 11 men and nine women, received either a plant-based, low-fat diet or an animal-based, low-carbohydrate diet for two weeks, immediately followed by two weeks on the alternate diet. The low-fat diet was high in carbohydrates. The low-carbohydrate diet was high in fats. Both diets were minimally processed and had equivalent amounts of non-starchy vegetables. The participants were given three meals a day, plus snacks, and could eat as much as desired.The main results showed that people on the low-fat diet ate 550 to 700 fewer calories per day than when they ate the low-carb diet. Despite the large differences in calorie intake, participants reported no differences in hunger, enjoyment of meals, or fullness between the two diets. Participants lost weight on both diets, but only the low-fat diet led to a significant loss of body fat."Despite eating food with an abundance of high glycemic carbohydrates that resulted in pronounced swings in blood glucose and insulin, people eating the plant-based, low-fat diet showed a significant reduction in calorie intake and loss of body fat, which challenges the idea that high-carb diets per se lead people to overeat. On the other hand, the animal-based, low-carb diet did not result in weight gain despite being high in fat," said Hall.These findings suggest that the factors that result in overeating and weight gain are more complex than the amount of carbs or fat in one's diet. For example, Hall's laboratory showed last year that a diet high in ultra-processed food led to overeating and weight gain in comparison to a minimally processed diet matched for carbs and fat.The plant-based, low-fat diet contained 10.3% fat and 75.2% carbohydrate, while the animal-based, low-carb diet was 10% carbohydrate and 75.8% fat. Both diets contained about 14% protein and were matched for total calories presented to the subjects, although the low-carb diet had twice as many calories per gram of food than the low-fat diet. On the low-fat menu, dinner might consist of a baked sweet potato, chickpeas, broccoli and oranges, while a low-carb dinner might be beef stir fry with cauliflower rice. Subjects could eat what and however much they chose of the meals they were given."Interestingly, our findings suggest benefits to both diets, at least in the short-term. While the low-fat, plant-based diet helps curb appetite, the animal-based, low-carb diet resulted in lower and more steady insulin and glucose levels," Hall said. "We don't yet know if these differences would be sustained over the long term."The researchers note that the study was not designed to make diet recommendations for weight loss, and results may have been different if participants were actively trying to lose weight. Further, all meals were prepared and provided for participants in an inpatient setting, which may make results difficult to repeat outside the lab, where factors such as food costs, food availability, and meal preparation constraints can make adherence to diets challenging. The tightly controlled clinical environment, however, ensured objective measurement of food intake and accuracy of data."To help us achieve good nutrition, rigorous science is critical ? and of particular importance now, in light of the COVID-19 pandemic, as we aim to identify strategies to help us stay healthy," said NIDDK Director Griffin P. Rodgers, M.D. "This study brings us closer to answering long-sought questions about how what we eat affects our health."The research was supported by the NIDDK Intramural Research Program. Additional NIH support came from the National Institute of Nursing Research under grant 1Z1ANR000035-01.
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Agriculture & Food
| 2,021 |
January 21, 2021
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https://www.sciencedaily.com/releases/2021/01/210121131809.htm
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Feral colonies provide clues for enhancing honey bee tolerance to pathogens
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Understanding the genetic and environmental factors that enable some feral honey bee colonies to tolerate pathogens and survive the winter in the absence of beekeeping management may help lead to breeding stocks that would enhance survival of managed colonies, according to a study led by researchers in Penn State's College of Agricultural Sciences.
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Feralization occurs when previously domesticated organisms escape to the wild and establish populations in the absence of human influence, explained lead researcher Chauncy Hinshaw, doctoral candidate in plant pathology and environmental microbiology."In the case of honey bees, colonies that escape domestication and establish in the wild provide an opportunity to study how environmental and genetic factors affect the fitness of feral organisms compared to their domesticated counterparts," Hinshaw said. "Some have suggested that the artificial selection associated with domestication of honey bees has decreased their fitness and has made managed colonies vulnerable to pests and pathogens."Feral honey bees frequently interact with both managed and wild bee species, playing a critical role in the dynamics of pathogens that are shared among these closely related groups, noted study co-author Margarita López-Uribe, assistant professor of entomology and Lorenzo L. Langstroth Early Career Professor."Both domesticated and feral honey bees face serious challenges from a large number of pests and pathogens, but feral honey bees must deal with diseases by themselves since they don't have beekeepers helping them control pest problems in the colony," she said. "This makes honey bees an ideal model to investigate the hypothesis that host-pathogen dynamics during feralization can result in higher disease pressure and pathogen tolerance in feral organisms."The research team set out to answer three questions: Are feral colonies reservoirs of pathogens, with high pathogen levels compared to managed colonies? Do increased pathogen levels lead to higher expression of immune genes in feral colonies than in managed colonies? Is immune gene expression correlated with survival of honey bee colonies?To address these questions, the researchers partnered with beekeepers to locate 25 feral honey bee colonies across Pennsylvania and paired each of those colonies with a managed colony within a seven-mile radius to control for climate and landscape variation. The team surveyed these colonies over a two-year period to measure winter survival, levels of three pathogens -- deformed wing virus, black queen cell virus and Nosema ceranae -- and expression of six genes that regulate immunity.Deformed wing virus, or DWV, is considered the most serious honey bee viral pathogen because of its prevalence worldwide and its role in winter losses of colonies. DWV and other viruses often are spread by parasitic Varroa mites, requiring beekeepers to implement management strategies to minimize mite infestations among their bees.The team's findings, recently published in "We also found that differential expression of the immune genes hymenoptaecin and vago increased the odds of overwintering survival in both managed and feral colonies," Hinshaw said. "As a result, these two genes could be considered biomarkers of honey bee health that can be used to predict the ability of a colony to survive the winter."López-Uribe said the results provide evidence for the role of feralization in altering pathogen landscapes and host immune responses."Our study was the first to show the association of host-pathogen dynamics with survival of feral colonies," she said. "Further research to identify the genetic mechanisms of virus tolerance and biomarkers of bee health can help breeding efforts to enhance these traits in selected honey bee stocks, with the goal of decreasing colony losses for the beekeeping industry."
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Agriculture & Food
| 2,021 |
January 21, 2021
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https://www.sciencedaily.com/releases/2021/01/210121092825.htm
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Could lab-grown plant tissue ease the environmental toll of logging and agriculture?
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It takes a lot to make a wooden table. Grow a tree, cut it down, transport it, mill it ... you get the point. It's a decades-long process. Luis Fernando Velásquez-García suggests a simpler solution: "If you want a table, then you should just grow a table."
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Researchers in Velásquez-García's group have proposed a way to grow certain plant tissues, such as wood and fiber, in a lab. Still in its early stages, the idea is akin in some ways to cultured meat -- an opportunity to streamline the production of biomaterials. The team demonstrated the concept by growing structures made of wood-like cells from an initial sample of cells extracted from zinnia leaves.While that's still a long way from growing a table, the work provides a possible starting point for novel approaches to biomaterials production that ease the environmental burden of forestry and agriculture. "The way we get these materials hasn't changed in centuries and is very inefficient," says Velásquez-García. "This is a real chance to bypass all that inefficiency."The paper will be published in the Beckwith says she's always been fascinated by plants, and inspiration for this project struck when she recently spent time on a farm. She observed a number of inefficiencies inherent to agriculture -- some can be managed, like fertilizer draining off fields, while others are completely out of the farmer's control, like weather and seasonality. Plus, only a fraction of the harvested plant is actually used for food or materials production."That got me thinking: Can we be more strategic about what we're getting out of our process? Can we get more yield for our inputs?" Beckwith says. "I wanted to find a more efficient way to use land and resources so that we could let more arable areas remain wild, or to remain lower production but allow for greater biodiversity." So, she brought plant production into the lab.The researchers grew wood-like plant tissue indoors, without soil or sunlight. They started with a zinnia plant, extracting live cells from its leaves. The team cultured the cells in a liquid growth medium, allowing them to metabolize and proliferate. Next, they transferred the cells into a gel and "tuned" them, explains Velásquez-García. "Plant cells are similar to stem cells in the sense that they can become anything if they are induced to."The researchers coaxed the cells to grow a rigid, wood-like structure using a mix of two plant hormones called auxin and cytokinin. By varying the levels of these hormones in the gel, they controlled the cells' production of lignin, an organic polymer that lends wood its firmness. Beckwith says she assessed the cellular composition and structure of the final product using fluorescence microscopy. "You can visually evaluate which cells are becoming lignified, and you can measure enlargement and elongation of cells." This procedure demonstrated that plant cells can be used in a controlled production process, resulting in a material optimized for a particular purpose.Velásquez-García sees this work as an extension of his lab's focus on microfabrication and additive manufacturing techniques like 3D printing. In this case, the plant cells themselves do the printing with the aid of the gel growth medium. Unlike an unstructured liquid medium, the gel acts as a scaffold for the cells to grow in a particular shape. "The idea is not only to tailor the properties of the material, but also to tailor the shape from conception," says Velásquez-García. Thus, he envisions the possibility of one day growing a table, no two-by-fours or wood glue necessary.The technology is far from market-ready. "The question is whether the technology can scale and be competitive on an economic or lifecycle basis," says David Stern, a plant biologist at Cornell University who was not involved with the research. He adds that scaling up this approach "would take significant financial and intellectual investment," likely from both government and private sources. Stern also points to tradeoffs in bringing pieces of forestry and agriculture into the lab. "Agriculture uses the sun's energy through photosynthesis, and -- except in irrigated lands -- natural rainfall. It does not require buildings, heat, or artificial light."The researchers acknowledge it's still early days for these lab-grown plant tissues -- the team will keep fine-tuning the controls, like hormone levels and pH of the gel, that give rise to the final material's properties. "It is really uncharted territory," says Velásquez-García. "One pending question is: How do we translate this success to other plant species? It would be naïve to think we can do the same thing for each species. Maybe they have different control knobs."Beckwith also anticipates challenges in growing plant tissues at large scales, such as facilitating gas exchange to the cells. The team hopes to overcome these barriers through further experimentation and eventually build production blueprints for lab-grown products, from wood to fibers.It's a radical yet elegant vision -- "a new paradigm," according to Borenstein. "There's an opportunity here to take advances in microfabrication and additive manufacturing technologies, and apply them to solve some really significant problems in the agriculture arena."This research was funded, in part, by the Draper Fellow Program.
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Agriculture & Food
| 2,021 |
January 21, 2021
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https://www.sciencedaily.com/releases/2021/01/210121084626.htm
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Common pesticides stop bees and flies from getting a good night's sleep
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Just like us, many insects need a decent night's sleep to function properly, but this might not be possible if they have been exposed to neonicotinoid insecticides, the most common form of insecticide used worldwide, suggests research by academics at the University of Bristol.
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Two studies by scientists at Bristol's Schools of Physiology, Pharmacology and Neuroscience and Biological Sciences have shown these insecticides affect the amount of sleep taken by both bumblebees and fruit flies, which may help us understand why insect pollinators are vanishing from the wild.Dr Kiah Tasman, Teaching Associate in the School of Physiology, Pharmacology and Neuroscience and lead author of the studies, said: "The neonicotinoids we tested had a big effect on the amount of sleep taken by both flies and bees. If an insect was exposed to a similar amount as it might experience on a farm where the pesticide had been applied, it slept less, and its daily behavioural rhythms were knocked out of synch with the normal 24-hour cycle of day and night."The fruit fly study published today [21 January] in As well as finding that typical agricultural concentrations of neonicotinoids ruined the flies' ability to remember, the researchers also saw changes in the clock in the fly brain which controls its 24-hour cycle of day and night.Dr James Hodge, Associate Professor in Neuroscience in the School of Physiology, Pharmacology and Neuroscience and senior author for the study, added: "Being able to tell time is important for knowing when to be awake and forage, and it looked like these drugged insects were unable to sleep. We know quality sleep is important for insects, just as it is for humans, for their health and forming lasting memories."Dr Sean Rands, Senior Lecturer in the School of Biological Sciences and co-author, explained: "Bees and flies have similar structures in their brains, and this suggests one reason why these drugs are so bad for bees is they stop the bees from sleeping properly and then being able to learn where food is in their environment."Neonicotinoids are currently banned in the EU, and we hope that this continues in the UK as we leave EU legislation."
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Agriculture & Food
| 2,021 |
January 21, 2021
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https://www.sciencedaily.com/releases/2021/01/210121131932.htm
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Early breeding reduced harmful mutations in sorghum
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When humans first domesticated maize some 9,000 years ago, those early breeding efforts led to an increase in harmful mutations to the crop's genome compared to their wild relatives, which more recent modern breeding has helped to correct.
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A new comparative study investigates whether the same patterns found in maize occurred in sorghum, a gluten-free grain grown for both livestock and human consumption. The researchers were surprised to find the opposite is true: Harmful mutations in sorghum landraces (early domesticated crops) actually decreased compared to their wild relatives.The study, "Comparative Evolutionary Genetics of Deleterious Load in Sorghum and Maize," published Jan. 15 in The research may inform future breeding efforts in both sorghum and maize."We assumed that maize and sorghum would have complementary patterns of deleterious mutations, because all the work that has been done in crops up to this point has shown an increase in deleterious burden in domesticates compared to wild relatives from which crops originate," Gore said. "But sorghum does not follow this pattern and it's very surprising."These "deleterious mutations," which potentially have a negative effect on the fitness of an organism, result from random genetic errors that occur every generation, and from ancient mutations that may be linked to beneficial genetic variants selected during crop domestication and improvement.In the study, the researchers ran population genetics simulations to help explain why sorghum failed to follow the same pattern found in maize.One major difference between maize and sorghum is that maize (wild and domesticated) is an "outcrosser," meaning its female flowers (ear shoots) are predominantly pollinated by other maize plants; domesticated sorghum is a "selfer," meaning the flowers of its panicles (heads) are mostly fertilized by each plant's own pollen.It turns out that sorghum's wild relatives have more open seed heads that facilitate outcrossing. But in the process of sorghum domestication, the panicles that hold these clusters of flowers became more compact, which increased "selfing" rates."We posit that the alteration of panicle morphology impacted deleterious mutation patterns in sorghum," Gore said. "The resultant increase in selfing likely contributed to the purging of deleterious mutations after domestication."By understanding the historical patterns of harmful mutations, breeders may use that knowledge to better purge deleterious mutations from sorghum crops. "What we're learning in sorghum could also be applied to maize and vice versa," Gore said.The study was funded by the U.S. Department of Energy.
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Agriculture & Food
| 2,021 |
January 20, 2021
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https://www.sciencedaily.com/releases/2021/01/210120085055.htm
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New antifungal compound from ant farms
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Attine ants are farmers, and they grow fungus as food.
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Attine ants originated as one species at a single location in the Amazon 50 million years ago. They have evolved to 200 species that have spread their farming practices throughout South and Central America. In exchange for food, bacteria at these farms produce small molecules that hold pathogenic fungi such as In a study of bacteria from ant nests at multiple sites in Brazil, the team discovered that nearly two thirds of
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Agriculture & Food
| 2,021 |
January 19, 2021
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https://www.sciencedaily.com/releases/2021/01/210119122111.htm
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Scientists reveal structure of plants' energy generators
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Researchers have revealed the first atomic structures of the respiratory apparatus that plants use to generate energy, according to a study published today in
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The 3D structures of these large protein assemblies -- the first described for any plant species -- are a step towards being able to develop improved herbicides that target plant respiration. They could also aid the development of more effective pesticides, which target the pest's metabolism while avoiding harm to crops.Most organisms use respiration to harvest energy from food. Plants use photosynthesis to convert sunlight into sugars, and then respiration to break down the sugars into energy. This involves tiny cell components called mitochondria and a set of five protein assemblies that arrange themselves in an 'electron transport train'."Knowing how plants convert energy through respiration is a crucial part of understanding how plants grow, how they adapt to changes in the environment and what strategies we can use to improve crop yields," explains first author Maria Maldonado, a postdoctoral fellow at the Department of Molecular and Cellular Biology, University of California, Davis (UC Davis), US. "Yet although the 3D structures of respiration components are well understood in mammals, fungi and bacteria, the technical challenges of gathering pure samples of mitochondrial complexes in plants mean these structures remain largely unknown."The team set out to obtain 3D structures of three components in the electron transport chain -- complex III, complex IV and supercomplex III-IV. They extracted mitochondria complexes from mung bean sprouts treated with a gentle detergent and then stabilised them before using cryo-electron microscopy to generate high-resolution structures. Based on these structures, the team then built atomic models showing how the complexes interact with other molecules, such as other proteins, ions and lipids. For each of the three complexes, they were able to determine the number and structure of subunits, and the likely molecules that bind to them and how flexible the structures are.Their models showed that several aspects of the complexes are shared between plants, mammals, fungi and bacteria, including several components that were originally thought to exist only in plants. However, the team also found several features of the complexes that are unique to plants, including the way the supercomplex III-IV assembles. This is important, because many agricultural herbicides and pesticides are designed to interfere with the respiratory complexes, and this finding could help to make them more selective for the pests they are intended to kill."Our work provides high-resolution structures of plant respiratory complexes that reveal plant-specific features, allowing for the development of more selective inhibitors as herbicides and pesticides," concludes senior author James Letts, Assistant Professor at the Department of Molecular and Cellular Biology, UC Davis, US. "Further comparative analyses of these structures with the growing number of respiratory complexes will allow us to understand the fundamental principles of respiration across the tree of life."
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Agriculture & Food
| 2,021 |
January 19, 2021
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https://www.sciencedaily.com/releases/2021/01/210119122051.htm
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Scientists to global policymakers: Treat fish as food to help solve world hunger
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Scientists are urging global policymakers and funders to think of fish as a solution to food insecurity and malnutrition, and not just as a natural resource that provides income and livelihoods, in a newly-published paper in the peer-reviewed journal
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The "Fish as Food" paper, authored by scientists and policy experts from Michigan State University, Duke University, Harvard University, World Bank and Environmental Defense Fund, among others, notes the global development community is not on track to meet goals for alleviating malnutrition. According to the U.N. Food and Agriculture Organization, the number of malnourished people in the world will increase from 678 million in 2018 to 841 million in 2030 if current trends continue -- an estimate not accounting for effects of the COVID-19 pandemic. Fish provide 17% of the animal protein consumed globally and are rich in micronutrients, essential fatty acids and protein essential for cognitive development and maternal and childhood health, especially for communities in developing countries where fish may be the only source of key nutrients. Yet fish is largely missing from key global food policy discussions and decision-making."Fish has always been food. But in this paper, we lay out an agenda for enhancing the role of fish in addressing hunger and malnutrition," says Abigail Bennett, assistant professor in the Center for Systems Integration and Sustainability in the Department of Fisheries and Wildlife at Michigan State University. "We are urging the international development community not only to see fish as food but to recognize fish as a nutrient-rich food that can make a difference for the well-being of the world's poor and vulnerable. What kinds of new knowledge, policies and interventions will be required to support that role for fish?" she adds.The United Nations' Sustainable Development Goal 2, Zero Hunger, does not mention fisheries or aquaculture by name, nor does it offer specific guidance on fish production systems. Fish also appear underrepresented in international development funding priorities, such as by the World Bank, the paper finds."Fish -- and aquatic foods in general -- are largely ignored in the food policy dialogue," says Kristin Kleisner, lead senior scientist for Environmental Defense Fund Oceans program and a co-author of the paper. "This is a huge oversight, as fish offer a critical source of nutrition unparalleled by any other type of food, and it is often the only source of key nutrients for vulnerable populations around the world."By refocusing on nutrition, in addition to the many other benefits fisheries provide, we're amplifying a call to action for governments, international development organizations and society more broadly to invest in the sustainability of capture fisheries and aquaculture," adds Kleisner."Fisheries will be ever more important as the world faces mounting challenges to feed itself," says Kelly Brownell, director of the World Food Policy Center at Duke University.Global policymakers and funders framing fish as food, the authors state, can encourage innovative policies and actions to support the role of fish in global food and nutrition security.The paper identifies four pillars of suggested action to begin framing fish as food, not just a natural resource. These pillars are:Sustainable fisheries and aquaculture are key to feeding the world and alleviating malnutrition and already provide valuable nutrition and livelihood contributions. Including a nutrition lens when illustrating the multiple benefits of sustainable fisheries production can help to elevate the importance and impact of fish as a key component of the global food system and to ensure that we do not fall behind in global food security targets.
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Agriculture & Food
| 2,021 |
January 15, 2021
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https://www.sciencedaily.com/releases/2021/01/210115110325.htm
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Filling a crucial gap in aquafarming: Ion beam breeding to the rescue
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A research team led by scientists at the RIKEN Nishina Center for Accelerator-Based Science (RNC) has successfully created larger-than-usual strains of zooplankton -- which are used in fish nurseries -- by creating mutations with a heavy ion beam. The new strains of zooplankton could contribute to improving the survival rate and optimizing the growth of juvenile fish in aquaculture.
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Economically important fish species, such as bluefin tuna, yellowtail, flatfish and groupers, are fed live bait until they are large enough to be fed with artificial foods. Rotifers, a type of animal plankton, are commonly used as the initial live food. However, fish need progressively larger bait as they grow, but rotifers are generally small and often not large enough to satisfy the growing fish, leading to cannibalism or growth abnormalities and eventually lowering the survival rate. "We decided to try to do something to improve the survival rate of fish larvae, as this would help to increase aquaculture productivity. We thought that if we could create a large rotifer strain using our expertise, it would contribute to stabilizing the income for aquafarmers," says Tomoko Abe from RIKEN RNC, who led the study, published in In collaboration with the Japan Fisheries Research and Education Agency and Nagasaki University, the research team began experimenting using a technique known as heavy ion beam irradiation in an attempt to create larger rotifers. Heavy ion breeding is a technique where cells are exposed to a beam of heavy atomic nuclei, creating mutations much more effectively than natural processes such as UV light. By adjusting the type of ion and dose, the beam is used to induce random mutations in the genome, and strains with desirable phenotypes can be selected. The team has already succeeded in developing highly effective mutant lines of oil-producing microalgae, high-yielding rice, and a commercialized sake yeast, using similar techniques.Using the RIKEN RI Beam Factory (RIBF) the team irradiated proliferating rotifers with beams of argon and carbon ions. They then selected larger individuals and cultured the plankton for several generations to create a large mutant line. The bred rotifers were approximately 1.2 times larger than other strains, which the group judged would be an ideal size for growing juvenile fish. They also found that some of the strains were not only larger, but also grew more quickly than the parent strains. "In general, larger mutants grow more slowly than normal rotifers, but we were lucky to discover a line that grows not only larger but faster as well," Abe recalls. "However, picking a large mutant among live rotifers that are moving quickly around under a microscope was far more difficult than we had anticipated and actually was the hardest part of this study."Food shortages due to population growth and increased consumption are a major global concern, and countries around the world are looking for ways to increase food production. Resources from the ocean, which occupies 70 percent of the Earth's surface area, can be an effective and promising solution to the problem. For Japan in particular, as an island nation with a large exclusive economic zone, increasing the production of marine resources is an attractive goal. The enlarged rotifers obtained in this study could potentially provide a stable supply of larger rotifers at low cost, enhancing aquaculture. Moving forward, the group now plans to use the larger rotifers in field tests to see if they can demonstrate improved survival.
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Agriculture & Food
| 2,021 |
January 14, 2021
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https://www.sciencedaily.com/releases/2021/01/210114163917.htm
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Hard to crack research reveals how crop roots penetrate hard soils
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Scientists have discovered a signal that causes roots to stop growing in hard soils which can be 'switched off' to allow them to punch through compacted soil -- a discovery that could help plants to grow in even the most damaged soils.
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An international research team, led by scientists from the University of Nottingham's Future Food Beacon and Shanghai Jiao Tong University has discovered how the plant signal 'ethylene' causes roots to stop growing in hard soils, but after this signal is disabled, roots are able to push through compacted soil. The research has been published in Hard (compacted) soils represent a major challenge facing modern agriculture that can reduce crop yields over 50% by reducing root growth, causing significant losses annually. Europe has over 33-million-hectares of soil prone to compaction which represents the highest in the world. Soil compaction triggers a reduction in root penetration and uptake of water and nutrients. Despite its clear importance for agriculture and global food security, the mechanism underpinning root compaction responses has been unclear until now.Professor Malcolm Bennett from the University of Nottingham School of Biosciences, said: "Understanding how roots penetrate hard soils has huge implications for agriculture, as this knowledge will be crucial for breeding crops more resilient to soil compaction. Our team's identification that the plant signal ethylene controls root responses to hard soil opens up new opportunities to select novel compaction resistant crops."The research utilised X-ray Computed Tomography scanners available at the Hounsfield Facility at the University of Nottingham to visualise in situ how plant roots responded to compacted soil. Professor Sacha Mooney from the University of Nottingham and Director of the Hounsfield Facility explained: "Prior to this research we assumed that the hardness of the soil prevented roots growing deeper. By using our imaging approach, we were able to see that roots continued growing in very hard soils when the ethylene signal was switched off. The potential for new crops that can now go deeper in soils and capture previously unavailable resources is really exciting!"The international team involved in this new Science paper includes researchers drawn from nine universities based in Europe, China and USA, integrating expertise spanning plant and soil sciences, bioimaging and mathematics. The team involves several early career researchers including Dr. Bipin Pandey and Dr. Rahul Bhosale who are funded by Royal Society Challenge Grant, BBSRC Discovery Fellowship and University of Nottingham Future Food Beacon awards.
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Agriculture & Food
| 2,021 |
January 13, 2021
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https://www.sciencedaily.com/releases/2021/01/210113161216.htm
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Shedding light on the secret reproductive lives of honey bees
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Honey bee health has been on the decline for two decades, with U.S. and Canadian beekeepers now losing about 25 to 40% of their colonies annually. And queen bees are failing faster than they have in the past in their ability to reproduce. The reason has been a mystery, but researchers at North Carolina State University and the University of British Columbia are finding answers.
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Their latest research, published Jan. 8 in the journal David Tarpy, a University Faculty Scholar and professor in NC State's Department of Entomology and Plant Pathology, says the study has important implications for beekeepers and their customers, the farmers who rely on honey bees to pollinate their crops."Beekeepers have identified problem queens as a top management concern, but what's causing the problem is largely invisible. Queens go bad, and we don't know why," Tarpy said.Alison McAfee, a postdoctoral scientist at NC State and UBC, was the study's lead author. She explained that to have a healthy hive, honey bees depend on a healthy queen, the only female bee in a colony that can reproduce.The queen mates with many males, but only early in life, storing all the sperm that she'll use in her lifetime in her spermatheca, an abdominal organ that looks like a tiny pearl. When the sperm begin to die, the queen can't produce as many fertilized eggs. That causes the colony's population to decline."Queens have the potential to live for five years, but these days, half the time queens (in managed honey bee colonies) are replaced within their first six months because they are failing," McAfee said. "If a beekeeper is really lucky, a queen might live two years. Beekeepers need answers about why their queens are failing."The more we can find out about what is actually happening within these failed queens, the closer we can get to understanding why this queen failure is happening in the first place."In their research, McAfee, Tarpy and their colleagues found that queens that were failing reproductively had significantly fewer sperm than ones that were reproductively thriving. And a higher percentage of the sperm they did have were dead. The researchers also discovered that compared to reproductively healthy queen bees, the failed queens were more likely to have higher levels of two viruses -- sacbrood virus and black queen cell virus."The high levels of these viruses and poor sperm viability made us interested in seeing if there was a trade-off happening in the honey bee queen," McAfee said. "There's a classical hypothesis in reproductive biology that you can't do everything well, so there's a trade-off between immunity and being able to reproduce. It's been found in quite a few other organisms, including insects, that there are such trade-offs."To find out if the same would be true with the honeybee queen, the researchers used a tool known as a mass spectrometer to gain a better picture of what was going on in the spermatheca of the healthy and failed queens. They identified 2,000 different proteins and determined which ones were linked to sperm viability.One of the most significant proteins linked to sperm viability, McAfee said, was lysozyme. Lysozyme is an enzyme that's part of animals' immune systems."The queens with the highest sperm viability had the lowest abundance of lysozyme, indicating that they weren't investing resources in this kind of immune response," McAfee added. "That supports this idea that there's a trade-off between the queens being able to fight off infections and being able to maintain their stored sperm."Tarpy said that the research could begin allowing researchers to find the cause of queen failure and find molecular tools that could "help identify bad queens upstream in the process before beekeepers use them and before they realize they're bad."Right now, the cause of queen failure isn't clear. "The underlying mechanisms could be disease. They could be pesticides. They could be improper nutrition," he said. "We don't know, so we are working our way backward to identify the causes."Once the causes are clearly understood, Tarpy added, scientists can then work forward "to help beekeepers keep mortality levels down to sustainable levels and thus keep their colonies thriving."
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Agriculture & Food
| 2,021 |
January 13, 2021
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https://www.sciencedaily.com/releases/2021/01/210113120702.htm
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Spilling the beans on coffee's true identity
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People worldwide want their coffee to be both satisfying and reasonably priced. To meet these standards, roasters typically use a blend of two types of beans, arabica and robusta. But, some use more of the cheaper robusta than they acknowledge, as the bean composition is difficult to determine after roasting. Now, researchers reporting in ACS'
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Coffee blends can have good quality and flavor. However, arabica beans are more desirable than other types, resulting in a higher market value for blends containing a higher proportion of this variety. In some cases, producers dilute their blends with the less expensive robusta beans, yet that is hard for consumers to discern. Recently, methods involving chromatography or spectroscopy were developed for coffee authentication, but most of these are labor- and time-intensive, or use chloroform for the extraction, which limits the types of compounds that can be detected. In some studies, researchers used nuclear magnetic resonance (NMR) spectroscopy to monitor the amount of 16-The researchers extracted compounds from a test set of pure coffee and known blends with methanol and identified the compounds with NMR. The team found 12 compounds with measurable concentrations, and two had significantly different amounts between the coffee varieties. Elevated concentrations of 16-OMC were unique to robusta, while high concentrations of kahewol -- a compound previously found in coffee beans by other researchers -- were distinct in arabica. There was a direct, reproducible relationship between 16-OMC and kahewol concentrations found in the blends of the two varieties. The team then measured 16-OMC and kahewol levels, in addition to other flavor molecules, in 292 samples from producers around the world. They could successfully authenticate pure coffee, even with relatively low concentrations of the two indicator compounds. For samples in which the composition of blends was known, the team's predictions were within 15% of the actual ratio. The new method results in a more robust and reliable way to verify unadulterated coffee and predict blends than previously reported approaches, the researchers say.
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Agriculture & Food
| 2,021 |
January 12, 2021
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https://www.sciencedaily.com/releases/2021/01/210112160142.htm
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Beating the 'billion-dollar bug' is a shared burden
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A lurking threat that has stymied US corn growers for decades is now returning to the forefront: western corn rootworm. Sometimes referred to as the "billion-dollar bug," the species' tiny larvae chew through the roots of corn plants, causing devastating yield losses. In 2003, farmers began planting a genetically engineered variety of corn known as "Bt," which produces a protein toxic to the pest species -- but by 2009, the billion-dollar bug had already evolved adaptations for resistance to the toxin.
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A new study suggests that slowing the resurgence of western corn rootworm may require a larger-scale strategy than previously thought. The findings, which were published in the Ecological Society of America's journal Primary author Coy St. Clair and his colleague Aaron Gassmann pinpointed 64 "problem fields" across Iowa, where western corn rootworm had caused greater-than-expected levels of injury to corn between 2009 and 2013 in two varieties of Bt maize: Cry3Bb1 and mCry3A. Compared to fields where rootworm had not damaged Bt maize, the problem fields had higher levels of continuous maize cultivation in surrounding buffer areas.Corn rows as far as the eye can see in Buchanan County, Iowa. Original image from Carol M. Highsmith's America, Library of Congress collection. Digitally enhanced by rawpixel.Regular crop rotation is a key strategy for interfering with rootworm's life cycle: when rootworm eggs hatch in a field without corn, the larvae starve before they have a chance to mature and lay eggs. However, continuous planting of corn tends to be more profitable in the short term, leaving corn growers with difficult decisions about how to manage risks.St. Clair, now a research entomologist for Genective (Champaign, Ill.) who conducted the research as a Ph.D. student at Iowa State University, says that the story of western corn rootworm resistance to Bt illustrates that pest mitigation is a shared responsibility. "If the pest remains susceptible, everyone benefits. If resistance develops, everyone suffers."Continuous maize cultivation gives nascent rootworm populations a chance to evolve resistance to the Bt toxin -- and for those newly resistant offspring to travel to other fields."The takeaway here is that a farmer who is employing best management practices -- such as frequent crop rotation, or planting of non-Bt maize -- will effectively manage rootworm and delay resistance in their own field firstly, while simultaneously helping to delay resistance development in surrounding populations secondly," explained St. Clair. "Conversely, a farmer who is planting multiple years of the same trait will risk resistance in their own field, while contributing to the depletion of the shared resource of trait susceptibility."As of 2020, agronomists have confirmed that populations of western corn rootworm resistant to the two Bt traits examined in the study are present across the US corn belt, along with two additional Bt traits.
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Agriculture & Food
| 2,021 |
January 12, 2021
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https://www.sciencedaily.com/releases/2021/01/210112125219.htm
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Immune response biomarkers, novel pathways in four marine mollusk species
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Understanding the immune systems of oysters and clams is important in monitoring the effects of pollution and climate change on the health of molluscan species and the potential impacts on the aquaculture industry. Their immune responses also can serve as indicators of changes in ocean environments.
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A new study involving the University of Maine assessed immune responses in four economically important marine mollusc species -- the blue mussel, soft-shell clam, Eastern oyster, and Atlantic jackknife clam -- and identified new biomarkers relating to changes in protein function involved in novel regulatory mechanisms of important metabolic and immunological pathways.The discovery will aid further biomarker identification to benefit the aquaculture industry and provides new understanding of how these pathways function in diverse ways in different animal species."These biomarkers reveal how several different physiological functions can be generated from a single protein sequence. This gives added value to an organism's physiology," says Tim Bowden, UMaine associate professor of aquaculture and co-author of the study published as the cover article in the December 2020 issue of the journal Bowden, a researcher in UMaine's School of Food and Agriculture and Aquaculture Research Institute, conducted the study with United Kingdom colleagues Igor Kraev of the Open University and Sigrun Lange of the University of Westminster.Oysters and clams play a critical role in the food chain, representing more than 7% of global marine capture fisheries products in 2018, according to the Food and Agriculture Organization of the United Nations. In the U.S., more than 82% of the 2018 total value for marine aquaculture was derived from clams, mussels and oysters. Understanding molluscan metabolism is a priority based on the role of marine mollusks in global ecosystems and their burgeoning commercial value.In their study of post-translational protein modification, the researchers found that deimination, or conversion of the amino acid arginine into the nonstandard amino acid citrulline, affects multiple pathways involved in immunity, metabolism and gene regulation.Deimination is known to play a role in human diseases such as Alzheimer's and Parkinson's.Study findings suggest that the enzymes that regulate deimination in mammals, birds and reptiles, and bacteria, parasites and fungi also are active in molluscan pathways. Peptidylarginine deiminases, or PADs, which had not previously been reported in Mollusca, may in fact serve as a control switch for varied immune and metabolic pathways in Mollusca and across the phylogenetic tree, according to the research team.The researchers documented species-specific variations in the size and distribution of extracellular vesicles (EVs) in the bivalves studied. EVs have multiple functions including transporting proteins, genetic cargoes and biomarkers into cells and mediating host-pathogen interactions, among others.Further investigation of the physiological and immune-related roles of EVs and characterization of the biomarkers they transport is warranted to enhance understanding of regulatory mechanisms and pathways in Mollusca and to support the global aquaculture industry.
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Agriculture & Food
| 2,021 |
January 12, 2021
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https://www.sciencedaily.com/releases/2021/01/210112125210.htm
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Study of flowers with two types of anthers solves mystery that baffled Darwin
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Most flowering plants depend on pollinators such as bees to transfer pollen from the male anthers of one flower to the female stigma of another flower, enabling fertilization and the production of fruits and seeds. Bee pollination, however, involves an inherent conflict of interest, because bees are only interested in pollen as a food source.
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"The bee and the plant have different goals, so plants have evolved ways to optimize the behavior of bees to maximize the transfer of pollen between flowers," explained Kathleen Kay, associate professor of ecology and evolutionary biology at UC Santa Cruz.In a study published December 23 in For years, the only explanation put forth for this phenomenon, called heteranthery, was that one set of anthers is specialized for attracting and feeding bees, while a less conspicuous set of anthers surreptitiously dusts them with pollen for transfer to another flower. This "division of labor" hypothesis has been tested in various species, and although it does seem to apply in a few cases, many studies have failed to confirm it.The new study proposes a different explanation and shows how it works in species of wildflowers in the genus "What's happening is the anthers open at different times, so the plant is doling out pollen to the bees gradually," Kay said.This "pollen dosing" strategy is a way of getting the bees to move on to another flower without stopping to groom the pollen off their bodies and pack it away for delivery to their nest. Bees are highly specialized for pollen feeding, with hairs on their bodies that attract pollen electrostatically, stiff hairs on their legs for grooming, and structures for storing pollen on their legs or bodies."If a flower doses a bee with a ton of pollen, the bee is in pollen heaven and it will start grooming and then go off to feed its offspring without visiting another flower," Kay said. "So plants have different mechanisms for doling out pollen gradually. In this case, the flower is hiding some anthers and gradually revealing them to pollinators, and that limits how much pollen a bee can remove in each visit."There are about 41 species of In these and other heterantherous clarkias, an inner whorl of anthers stands erect in the center of the flower, is visually conspicuous, and matures early, releasing its pollen first. An inconspicuous outer whorl lies back against the petals until after the inner anthers have opened. The outer anthers then move toward the center of the flower and begin to release their pollen gradually. A few days later, the stigma becomes erect and sticky, ready to receive pollen from another flower."In the field, you can see flowers in different stages, and using time-lapse photography we could see the whole sequence of events in individual flowers," Kay said.The division of labor hypothesis requires both sets of anthers to be producing pollen at the same time. Kay said she decided to investigate heteranthery after observing clarkia flowers at a field site and realizing that explanation didn't fit. "I could see some flowers where one set was active, and some where the other set was active, but no flowers where both were active at the same time," she said.In "The color difference was convenient, because otherwise it's very hard to track pollen," Kay said. "We showed that bees are collecting and transporting pollen from both kinds of anthers, so they are not specialized for different functions."Kay said she didn't realize how much time Darwin had spent puzzling over heteranthery until she started studying it herself. "He figured out so many things, it's hard to find a case where he didn't figure it out," she said. Darwin might have been on the right track, though. Shortly before his death, he requested seeds of In addition to Kay, the coauthors of the paper include postdoctoral scholar Tania Jogesh and two UCSC undergraduates, Diana Tataru and Sami Akiba. Both students completed senior theses on their work and were supported by UCSC's Norris Center for Natural History.
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Agriculture & Food
| 2,021 |
January 11, 2021
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https://www.sciencedaily.com/releases/2021/01/210111112220.htm
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Bacterium protects rice plants from diseases
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Rice is the staple food of about half the world's population. The cultivation of the rice plant is very water-intensive and, according to the German aid organization Welthungerhilfe, around 15 per cent of rice is grown in areas with a high risk of drought. Global warming is therefore becoming increasingly problematic for rice cultivation, leading more and more often to small harvests and hunger crises. Crop failures caused by plant pathogens further aggravate the situation. Here, conventional agriculture is trying to counteract this with pesticides, which are mostly used as a precautionary measure in rice cultivation. The breeding of resistant plants is the only alternative to these environmentally harmful agents -- and currently only moderately successful. If the plants are resistant to one pathogen thanks to their breeding, they are usually more susceptible to other pathogens or are less robust under adverse environmental conditions.
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For this reason, an international research group which includes the Institute of Environmental Biotechnology at Graz University of Technology has been studying the microbiome of rice plant seeds for some time now in order to establish correlations between plant health and the occurrence of certain microorganisms. The group has now achieved a major breakthrough. They identified a bacterium inside the seed that can lead to complete resistance to a particular pathogen and is naturally transmitted from one plant generation to another. The findings published in the scientific journal In conventional rice cultivation in the Chinese province of Zhejiang, it was observed that one genotype of rice plants (cultivar Zhongzao 39) sometimes develops resistance to the plant pathogen Burkholderia plantarii. This pathogen leads to crop failures and also produces a biotoxin that can cause organ damage and tumours in persistently exposed humans and animals. "Up to now, the sporadic resistance of rice plants to this pathogen could not be explained," says Tomislav Cernava from the Institute of Environmental Biotechnology at Graz University of Technology. Together with the luminary of microbiome research and Institute head, Gabriele Berg, and his institute colleague Peter Kusstatscher, Cernava has been investigating the microbiome of rice seeds from different cultivation regions in detail in the context of a collaboration with Zhejiang University (Hangzhou) and Nanjing Agricultural University in China as well as with the Japanese Hokkaido University in Sapporo.The scientists found that the resistant plants have a different bacterial composition inside the seeds than the disease-susceptible plants. The bacterial genus Sphingomonas in particular was found significantly more often in resistant seeds. The researchers therefore isolated bacteria of this genus from the seeds and identified the bacterium Sphingomonas melonis as the responsible agent for disease resistance. This bacterium produces an organic acid (anthranilic acid), which inhibits the pathogen and thereby renders it harmless. "This also works when the isolated Sphingomonas melonis is applied to non-resistant rice plants. This automatically makes them resistant to the plant pathogen Burkholderia plantarii," explains Tomislav Cernava. In addition, the bacterium establishes itself in certain rice genotypes and is then passed on naturally from one plant generation to the next. "The potential of this finding is enormous. In the future, we will be able to use this strategy to reduce pesticides in agriculture and at the same time achieve good crop yields," emphasizes Cernava.
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Agriculture & Food
| 2,021 |
January 6, 2021
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https://www.sciencedaily.com/releases/2021/01/210106142642.htm
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Shiga toxin's not supposed to kill you
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E. coli food poisoning is one of the worst food poisonings, causing bloody diarrhea and kidney damage. But all the carnage might be just an unintended side effect, researchers from UConn Health report in the 27 November issue of
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Escherichia coli are a diverse group of bacteria that often live in animal guts. Many types of E. coli never make us sick; other varieties can cause traveler's diarrhea. But swallowing even a few cells of the type of E. coli that makes Shiga toxin can make us very, very ill. Shiga toxin damages blood vessels in the intestines, causing bloody diarrhea. If Shiga toxin gets into the bloodstream it can cause kidney failure."This is especially common in children; about 15% of kids with Shiga toxin-producing E. coli infections get kidney disease, and some can suffer long term kidney damage," says UConn Health immunologist Sivapriya Vanaja.A group of Shiga toxin-producing E. coli called enterohemorrhagic E. coli, or EHEC, are especially common in the United States. When you hear that a batch of romaine lettuce is being recalled because of a dangerous outbreak of food poisoning, it's almost certainly due to EHEC.EHEC normally live in cattle without making them sick. It used to be relatively common to have EHEC outbreaks coming from unhygienically prepared ground meat, but stringent regulations on slaughterhouses have made this less common. Now it's more likely for EHEC to appear on vegetables grown in fields adjacent to cattle or manure runoff.But no matter where it comes from, once EHEC bacteria get inside a human, the infection is hard to treat. Antibiotics tend to make it worse -- when the bacteria feel themselves dying, they make more Shiga toxin. And EHEC are very good at inhibiting the part of the immune system that normally responds early to this kind of infection, allowing them to grow unchecked in the human gut.In a study led by Morena Havira, a postdoctoral fellow in Vanaja's lab, the team wanted to know how EHEC suppresses the immune system. The body normally responds to early stages of E. coli infections by activating an enzyme that kicks off an alarm inside cells. The cell bursts open to release a cloud of warning molecules that call other parts of the immune system to come and fight the bacteria.But EHEC squashes that early response. To figure out how it does that, Vanaja and her colleagues decided to see which individual gene in EHEC was responsible. They took many different varieties of EHEC from a bacterial mutant library, and infected immune cells with them.The team found that cells infected with EHEC that was missing the gene for Shiga toxin mustered a higher immune response compared to normal EHEC."It was surprising. Shiga toxin is very well-studied for its toxic activity; it wasn't known that it had another function," Dr. Vanaja says. So Shiga toxin's stealthy suppression of the immune system may have a link to all the bloody drama that ensues. Spurred on by this exciting observation, they conducted a series of detailed molecular studies, which revealed that Shiga toxin blocks a protein from bursting open the infected cell and alerting the body of infection.Now that Vanaja and her colleagues know the specific molecular step Shiga toxin interferes with inside the immune cells, they are trying to figure out how, exactly, it blocks it. Once they know that, they may be able to find medicines that prevent toxin from interfering with immune responses.
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Agriculture & Food
| 2,021 |
December 28, 2020
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https://www.sciencedaily.com/releases/2020/12/201228114601.htm
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Big bumblebees learn locations of best flowers
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Big bumblebees take time to learn the locations of the best flowers, new research shows.
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Meanwhile smaller bumblebees -- which have a shorter flight range and less carrying capacity -- don't pay special attention to flowers with the richest nectar.University of Exeter scientists examined the "learning flights" which most bees perform after leaving flowers.Honeybees are known to perform such flights -- and the study shows bumblebees do the same, repeatedly looking back to memorise a flower's location."It might not be widely known that pollinating insects learn and develop individual flower preferences, but in fact bumblebees are selective," said Natalie Hempel de Ibarra, Associate Professor at Exeter's Centre for Research in Animal Behaviour."On leaving a flower, they can actively decide how much effort to put into remembering its location."The surprising finding of our study is that a bee's size determines this decision making and the learning behaviour."In the study, captive bees visited artificial flowers containing sucrose (sugar) solution of varying concentrations.The larger the bee, the more its learning behaviour varied depending on the richness of the sucrose solution.Smaller bees invested the same amount of effort in learning the locations of the artificial flowers, regardless of whether sucrose concentration was high or low."The differences we found reflect the different roles of bees in their colonies," said Professor Hempel de Ibarra."Large bumblebees can carry larger loads and explore further from the nest than smaller ones."Small ones with a smaller flight range and carrying capacity cannot afford to be as selective, so they accept a wider range of flowers."These small bees tend to be involved more with tasks inside the nest -- only going out to forage if food supplies in the colony are running low."The study was conducted in collaboration with scientists from the University of Sussex.The bees were observed in greenhouses at the University of Exeter's award-winning Streatham Campus, and Professor Hempel de Ibarra thanked the university's Grounds and Gardens team for their continued support.The study was funded by the Leverhulme Trust.
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Agriculture & Food
| 2,020 |
December 23, 2020
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https://www.sciencedaily.com/releases/2020/12/201223091538.htm
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Genetic engineering without unwanted side effects helps fight parasites
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Around a third of the world's population carries
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The parasite has a complex life cycle and infests virtually all warm-blooded creatures, including wild rodents and birds. It is introduced into livestock, and thus into humans, exclusively via cats. Only in this main host infectious stages form that are shed with the feces into the environment as encapsulated oocysts and from there enter the food chain."If we succeed in preventing the production of these oocysts, we can reduce the occurrence of toxoplasmosis among humans and animals," says Adrian Hehl, professor of parasitology and Vice Dean of Research and Academic Career Development at the University of Zurich's Vetsuisse Faculty. He and his research group have developed methods making an intervention of this sort possible.In earlier research, the team already identified various genes that are responsible for the formation of oocysts. This has enabled them to develop a live vaccine for toxoplasmosis: the researchers can use the CRISPR-Cas9 gene editing scissors to switch off these essential genes and infect or inoculate cats with the modified parasites. These pathogens do not produce infectious oocysts, but still protect cats from natural infection with To make the sterile parasites, the researchers used the CRISPR-Cas9 gene editing scissors. While this enables precise modifications to the genetic material, depending on the protocol the method generally used can also have disadvantages. Errors and unintended genetic alterations can creep in. Now the research group around Hehl reports that in For CRISPR-Cas9 gene editing, scientists usually insert a ring-shaped piece of DNA, a so-called plasmid, into the cell. This contains all the information necessary to create the gene scissors and the elements that recognize the desired place in the genetic material. The cell thus produces all the components of the gene scissors itself. Afterwards, however, the plasmid remains in the cell and can trigger additional, unplanned genetic changes.The method used by the Zurich team works differently. The researchers assemble the preprogrammed gene scissors outside the cell and then implant them directly into the parasites. After the genetic material has been manipulated, the components are very rapidly broken down completely, with only the desired edit remaining."Our approach isn't just quicker, cheaper and more efficient than conventional methods. It also enables the genomic sequence to be altered without leaving traces in the cell," explains Hehl. "This means we can now manufacture experimental live vaccines without plasmids or building in resistance genes."Given these results, Hehl questions the federal government's plans to make CRISPR-Cas9 genome editing subject to the existing law on genetic engineering (and the moratorium, which has been extended to 2025): "Our method is good example of how this new technology differs from conventional approaches to genetic engineering." He says that it is now possible to inactivate a gene without leaving unwanted traces in the genetic material, in a way which is indistinguishable from naturally occurring mutations. Unlike many other controversial applications of genetic engineering, this procedure does not affect the production of food either, and thus does not constitute a direct intervention in the food chain.
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Agriculture & Food
| 2,020 |
December 22, 2020
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https://www.sciencedaily.com/releases/2020/12/201222101500.htm
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Bumblebees lacking high-quality habitat have higher pathogen loads
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Bumble bees found in low-quality landscapes -- characterized by a relative lack of spring flowers and quality nesting habitat -- had higher levels of disease pathogens, as did bumble bees in areas with higher numbers of managed honey bee hives, according to research led by Penn State scientists.
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The results of the study, which examined how a variety of environmental and landscape characteristics influence infectious disease prevalence and bee health, can be used to inform management practices to support the conservation of bee species that provide essential pollination services in natural and agricultural ecosystems, the researchers said."Recent worldwide declines in wild and managed bee populations have been attributed to several factors," said the study's lead author, D.J. McNeil, postdoctoral fellow in the Insect Biodiversity Center in Penn State's College of Agricultural Sciences. "For example, extensive habitat loss and degradation has led to a lack of flowers and nest sites, which in turn has contributed to the loss of wild bee abundance and diversity."He pointed out that more recently, some bee losses -- especially among honey bees and bumble bees -- have been blamed on rising levels of novel bee pathogens, perhaps exacerbated by other factors that weaken bee immunity or resistance."Many of the factors known to undermine bee health, such as poor nutrition or exposure to pesticides, can increase susceptibility to disease," McNeil said. "Bees are more likely to be nutritionally deprived in landscapes with fewer and less diverse flowering plants, and poor nutrition can reduce the immune response and increase pathogen and parasite loads."The incidence and loads of a particular pathogen or parasite in bee populations likely are influenced by the composition of bee communities as well, noted study co-author Heather Hines, associate professor of biology and entomology, Penn State. She explained that the incidence of viruses and parasites in wild bumble bees was higher in the presence of honey bee colonies, which often harbor higher loads of pathogens that are transmissible to native bees."Given all these interacting factors, disease prevalence and virulence can be challenging to predict in wild bee populations," Hines said. "Our study is among the first to use data from a large geographic scale to evaluate the relative role of landscape features on the distribution and loads of key pathogens and parasites in wild bees."To measure pathogen loads, the researchers analyzed specimens of the common eastern bumble bee -- Bombus impatiens, the most abundant bumble bee species in the region. The team collected bumble bee workers from sites across Pennsylvania during peak bumble bee abundance from late June to mid-July in 2018 and 2019. These sites, which included 38 of Pennsylvania's 67 counties, were selected to represent evenly the span of the state and to include a diversity of habitat types and land use patterns.The researchers then screened for three pathogens known to infect bees -- deformed wing virus, black queen cell virus and Vairimorpha, a microsporidian parasite -- as well as for expression of a gene that regulates immunity. Using statistical analysis techniques, they correlated pathogen presence and loads with several recognized landscape-scale stressors, such as floral abundance, nesting habitat quality, insecticide loading, climatic conditions and interactions with managed honey bees.Their findings, reported in McNeil said results of the study highlight the need to maintain and create high-quality landscapes, such as those with abundant floral and nesting resources, to support healthy wild bee populations. The findings also draw particular focus to the value of spring floral resources, which often are less emphasized in pollinator garden plantings than mid-summer forage."Our results suggest that it may be possible to predict potential risks from pathogens and parasites based on these landscape indices, which can help inform decisions as to where habitat restoration and conservation practices should be applied," he said. "This is particularly timely in light of widespread population declines in many insect groups, especially pollinators like bumble bees."The researchers said they hope to incorporate this information into Beescape, an online tool that allows people across the United States to evaluate their landscape quality. They encourage Pennsylvania homeowners, growers and conservationists to read the Pennsylvania Pollinator Protection Plan, which contains a chapter on best practices for creating forage and habitat for bees in urban, agricultural and natural landscapes.
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Agriculture & Food
| 2,020 |
December 22, 2020
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https://www.sciencedaily.com/releases/2020/12/201222101450.htm
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New flower from 100 million years ago
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Oregon State University researchers have identified a spectacular new genus and species of flower from the mid-Cretaceous period, a male specimen whose sunburst-like reach for the heavens was frozen in time by Burmese amber.
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"This isn't quite a Christmas flower but it is a beauty, especially considering it was part of a forest that existed 100 million years ago," said George Poinar Jr., professor emeritus in the OSU College of Science.Findings were published in the "The male flower is tiny, about 2 millimeters across, but it has some 50 stamens arranged like a spiral, with anthers pointing toward the sky," said Poinar, an international expert in using plant and animal life forms preserved in amber to learn more about the biology and ecology of the distant past.A stamen consists of an anther -- the pollen-producing head -- and a filament, the stalk that connects the anther to the flower."Despite being so small, the detail still remaining is amazing," Poinar said. "Our specimen was probably part of a cluster on the plant that contained many similar flowers, some possibly female."The new discovery has an egg-shaped, hollow floral cup -- the part of the flower from which the stamens emanate; an outer layer consisting of six petal-like components known as tepals; and two-chamber anthers, with pollen sacs that split open via laterally hinged valves.Poinar and collaborators at OSU and the U.S. Department of Agriculture named the new flower The flower became encased in amber on the ancient supercontinent of Gondwana and rafted on a continental plate some 4,000 miles across the ocean from Australia to Southeast Asia, Poinar said.Geologists have been debating just when this chunk of land -- known as the West Burma Block -- broke away from Gondwana. Some believe it was 200 million years ago; others claim it was more like 500 million years ago.Numerous angiosperm flowers have been discovered in Burmese amber, the majority of which have been described by Poinar and a colleague at Oregon State, Kenton Chambers, who also collaborated on this research.Angiosperms are vascular plants with stems, roots and leaves, with eggs that are fertilized and develop inside the flower.Since angiosperms only evolved and diversified about 100 million years ago, the West Burma Block could not have broken off from Gondwana before then, Poinar said, which is much later than dates that have been suggested by geologists.Joining Poinar and Chambers, a botany and plant pathology researcher in the OSU College of Agricultural Sciences, on the paper were Oregon State's Urszula Iwaniec and the USDA's Fernando Vega. Iwaniec is a researcher in the Skeletal Biology Laboratory in the College of Public Health and Human Sciences and Vega works in the Sustainable Perennial Crops Laboratory in Beltsville, Maryland.
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Agriculture & Food
| 2,020 |
December 21, 2020
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https://www.sciencedaily.com/releases/2020/12/201221173140.htm
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Biotech cotton key to eliminating devastating pest from US and Mexico
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For much of the past century, the invasive pink bollworm wreaked havoc in the southwestern United States and northern Mexico -- inflicting tens of millions of dollars in damage annually to cotton on both sides of the border.
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A multifaceted strategy combining genetically engineered cotton with classical pest control tactics eradicated the pink bollworm from cotton-producing areas of the continental U.S. and Mexico, according to a new study to be published in "Although pink bollworm remains a daunting pest in over 100 countries, our strategic coalition rid the U.S. and Mexico of this invasive insect," said lead study author Bruce Tabashnik, a Regents Professor in the University of Arizona Department of Entomology."By analyzing computer simulations and 21 years of field data from Arizona, we discovered that genetically engineered cotton and the release of billions of sterile pink bollworm moths acted synergistically to suppress this pest," said Jeffrey Fabrick, a co-author of the study and a research entomologist with the U.S. Department of Agriculture's Agricultural Research Service.According to the study, the eradication program saved U.S. cotton growers $192 million from 2014 to 2019. It also helped to reduce insecticides sprayed against all cotton pests by 82%, preventing the application of over a million pounds of insecticides per year in Arizona.Native to Australasia -- a region that comprises Australia, New Zealand and some neighboring islands -- the pink bollworm is one of the world's most invasive insects. After female moths lay their eggs on cotton plants, the caterpillars hatch, bore into cotton bolls and devour the seeds within. Their feasting disrupts production of cotton lint.This voracious pest was first detected in the U.S. in 1917. Using field data from 1969, the new study estimates that over 200 billion pink bollworm caterpillars infested cotton fields in Arizona that year. In 1990, the pest cost Arizona cotton growers $32 million in damages, despite $16 million invested in insecticides to control it.The tide began to turn in 1996, with the introduction of cotton genetically engineered to produce proteins from the bacterium Bacillus thuringiensis. The proteins in Bt cotton kill pink bollworm and other caterpillar pests but are harmless to people and most beneficial insects.Although Bt cotton kills essentially 100% of susceptible pink bollworm caterpillars, the pest rapidly evolved resistance to Bt proteins in laboratory experiments at the University of Arizona and in Bt cotton fields in India.To delay pest resistance, UArizona scientists worked with farmers to develop and implement a strategy of planting non-Bt cotton refuges to allow survival of susceptible insects. Tabashnik's team also determined the mutations that cause resistance in the lab and used DNA screening to monitor for those adaptations in the field.Within 10 years, the use of Bt cotton reduced pink bollworm populations by 90%. For the first time since the pest's arrival, eradication seemed within grasp."In contrast with the rapid evolution of pest resistance to genetically engineered crops elsewhere, Bt cotton was suppressing this pest in Arizona for 10 years," Tabashnik explained. "We said, 'Let's take this a step further. Let's throw everything but the kitchen sink at it and get rid of it. If not forever, for as long as we can sustain it.'"In a concerted, binational effort, University of Arizona Cooperative Extension and research scientists joined forces with cotton growers, the biotech industry and government partners to devise the first program of its kind to eradicate the invasive pest.In addition to traditional pest control tactics, such as plowing cotton fields after harvest to reduce the pest's overwintering survival, a novel strategy largely replacing refuges of non-Bt cotton with mass releases of sterile pink bollworm moths was initiated in Arizona in 2006.The sterile moths were released from airplanes by the billions to overwhelm field populations of the pest. In concert, the U.S. Environmental Protection Agency waived the requirement for planting refuges, allowing farmers in Arizona to plant up to 100% Bt cotton.To test the success of this multipronged attack, scientists with the University of Arizona College of Agriculture and Life Sciences conducted computer simulations and analyzed field data collected in Arizona from 1998 to 2018. Their results show neither of the two tactics would have worked alone."In this era plagued by invasive organisms, as well as doubts about the power of science and controversy about genetic engineering, the study exemplifies the tremendous benefits of collaboration and synergy between biotechnology and classical tactics," Tabashnik said. "We hope the concepts illustrated here will inspire integrated approaches to combat other invasive life forms."
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Agriculture & Food
| 2,020 |
December 21, 2020
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https://www.sciencedaily.com/releases/2020/12/201221134205.htm
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Variety: Spice of life for bumble bees
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The yield and quality of many crops benefit from pollination, but it isn't just honey bees that do this work: bumble bees also have a role. However, placing honey bee or bumble bee colonies next to the field does not guarantee that they will visit the desired plants since there may be other plant species flowering at the same time that prove more attractive. A team from the University of Göttingen, together with researchers from the University of Applied Sciences Mittweida and the Julius Kühn Institute, used innovative molecular biological methods and traditional microscopy to investigate the pollen collecting behaviour of honey bees and bumble bees in agricultural landscapes. They show that bumble bees take much more pollen from dif-ferent plant species than honey bees to satisfy their need for protein. Furthermore, less pollen from the target -- in this case strawberry plants -- is collected when there are fields of flowering oilseed rape in the surrounding landscape. The results have been published in the journal
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The researchers placed honey bee and bumble bee colonies next to strawberry fields in the Göttingen and Kassel region and collected pollen from returning honey bees and bumble bees. The bees collect the pro-tein-rich pollen mainly for feeding their offspring. The pollen DNA was investigated working closely with the Division of Molecular Biology of Livestock and molecular Diagnostics at the University of Göttingen, and the Department of Biochemistry/Molecular Biology of the Mittweida University of Applied Sciences. "DNA analysis tells us which plant species the bees have visited and how diverse their foraging behaviour is. To do this, we sequenced the DNA of the pollen and compared the sequences using a database of regional plant species," says Dr Svenja Bänsch, post-doctoral researcher in Functional Agrobiodiversity at the Uni-versity of Göttingen."Our study shows that honey bees and bumble bees use very different plants to source their pollen in the landscape. In particular, the wide range of bumble bee nutrition, which they find mainly in flower-rich habi-tats, should be taken into account when taking steps to improve nature conservation. Both honey bees and bumble bees, whose colonies can be purchased or rented, are suitable pollinators in strawberry cultivation. However, naturally occurring wild bees should be encouraged as a priority," concludes Professor Catrin Westphal, Head of Functional Agrobiodiversity at the University of Göttingen.
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Agriculture & Food
| 2,020 |
December 20, 2020
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https://www.sciencedaily.com/releases/2020/12/201220103944.htm
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Plants can be larks or night owls just like us
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Plants have the same variation in body clocks as that found in humans, according to new research that explores the genes governing circadian rhythms in plants.
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The research shows a single letter change in their DNA code can potentially decide whether a plant is a lark or a night owl. The findings may help farmers and crop breeders to select plants with clocks that are best suited to their location, helping to boost yield and even the ability to withstand climate change.The circadian clock is the molecular metronome which guides organisms through day and night -- cockadoodledooing the arrival of morning and drawing the curtains closed at night. In plants, it regulates a wide range of processes, from priming photosynthesis at dawn through to regulating flowering time.These rhythmic patterns can vary depending on geography, latitude, climate and seasons -- with plant clocks having to adapt to cope best with the local conditions.Researchers at the Earlham Institute and John Innes Centre in Norwich wanted to better understand how much circadian variation exists naturally, with the ultimate goal of breeding crops that are more resilient to local changes in the environment -- a pressing threat with climate change.To investigate the genetic basis of these local differences, the team examined varying circadian rhythms in Swedish Arabidopsis plants to identify and validate genes linked to the changing tick of the clock.Dr Hannah Rees, a postdoctoral researcher at the Earlham Institute and author of the paper, said: "A plant's overall health is heavily influenced by how closely its circadian clock is synchronised to the length of each day and the passing of seasons. An accurate body clock can give it an edge over competitors, predators and pathogens."We were interested to see how plant circadian clocks would be affected in Sweden; a country that experiences extreme variations in daylight hours and climate. Understanding the genetics behind body clock variation and adaptation could help us breed more climate-resilient crops in other regions."The team studied the genes in 191 different varieties of Arabidopsis obtained from across the whole of Sweden. They were looking for tiny differences in genes between these plants which might explain the differences in circadian function.Their analysis revealed that a single DNA base-pair change in a specific gene -- COR28 -- was more likely to be found in plants that flowered late and had a longer period length. COR28 is a known coordinator of flowering time, freezing tolerance and the circadian clock; all of which may influence local adaptation in Sweden."It's amazing that just one base-pair change within the sequence of a single gene can influence how quickly the clock ticks," explained Dr Rees.The scientists also used a pioneering delayed fluorescence imaging method to screen plants with differently-tuned circadian clocks. They showed there was over 10 hours difference between the clocks of the earliest risers and latest phased plants -- akin to the plants working opposite shift patterns. Both geography and the genetic ancestry of the plant appeared to have an influence."Arabidopsis thaliana is a model plant system," said Dr Rees. "It was the first plant to have its genome sequenced and it's been extensively studied in circadian biology, but this is the first time anyone has performed this type of association study to find the genes responsible for different clock types."Our findings highlight some interesting genes that might present targets for crop breeders, and provide a platform for future research. Our delayed fluorescence imaging system can be used on any green photosynthetic material, making it applicable to a wide range of plants. The next step will be to apply these findings to key agricultural crops, including brassicas and wheat."The results of the study have been published in the journal
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Agriculture & Food
| 2,020 |
December 17, 2020
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https://www.sciencedaily.com/releases/2020/12/201217135258.htm
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What's up, Skip? Kangaroos really can 'talk' to us, study finds
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Animals that have never been domesticated, such as kangaroos, can intentionally communicate with humans, challenging the notion that this behaviour is usually restricted to domesticated animals like dogs, horses or goats, a first of its kind study from the University of Roehampton and the University of Sydney has found.
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The research which involved kangaroos, marsupials that were never domesticated, at three locations across Australia*, revealed that kangaroos gazed at a human when trying to access food which had been put in a closed box. The kangaroos used gazes to communicate with the human instead of attempting to open the box themselves, a behaviour that is usually expected for domesticated animals.Ten out of 11 kangaroos tested actively looked at the person who had put the food in a box to get it (this type of experiment is known as "the unsolvable problem task"). Nine of the 11 kangaroos additionally showed gaze alternations between the box and the person present, a heightened form of communication where they look between the box and human.The research builds on previous work in the field which has looked at the communication of domesticated animals, such as dogs and goats, and whether intentional communication in animals is a result of domestication. Lead author Dr Alan McElligott, University of Roehampton (now based at City University of Hong Kong), previously led a study which found goats can understand human cues, including pointing, to gather information about their environment. Like dogs and goats, kangaroos are social animals and Dr McElligott's new research suggests they may be able to adapt their usual social behaviours for interacting with humans.Dr Alan McElligott said: "Through this study, we were able to see that communication between animals can be learnt and that the behaviour of gazing at humans to access food is not related to domestication. Indeed, kangaroos showed a very similar pattern of behaviour we have seen in dogs, horses and even goats when put to the same test."Our research shows that the potential for referential intentional communication towards humans by animals has been underestimated, which signals an exciting development in this area. Kangaroos are the first marsupials to be studied in this manner and the positive results should lead to more cognitive research beyond the usual domestic species."Dr Alexandra Green, School of Life and Environmental Sciences at the University of Sydney, said: "Kangaroos are iconic Australian endemic fauna, adored by many worldwide but also considered as a pest. We hope that this research draws attention to the cognitive abilities of kangaroos and helps foster more positive attitudes towards them."*The study involved kangaroos at three locations in Australia: Australian Reptile Park, Wildlife Sydney Zoo and Kangaroo Protection Co-Operative. The research was funded by a grant from the Association for the Study of Animal Behaviour (ASAB).
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Agriculture & Food
| 2,020 |
December 17, 2020
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https://www.sciencedaily.com/releases/2020/12/201217135235.htm
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Boosting vegetable oil production in plant leaves
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Since antiquity, cultures around the world have been extracting vegetable oil from plants to use as food and fuel. Some vegetable oils have important health benefits, including lowering cholesterol levels and decreasing the risk of cardiovascular disease.
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But there's a problem: Vegetable oils are traditionally extracted from fruits or seeds, and the extraction process often leads to the rest of the plant being discarded in the process. Now, Jay Thelen, a professor of biochemistry at the University of Missouri, has found a way to boost the production of triacylglycerol -- the main component of vegetable oil -- in plant leaves, a technique that could allow producers to harvest oil from large, leafy plants that also have other uses. Sorghum, for example -- a global source of grain prized for its drought-resistant qualities -- could serve a dual role as a source of vegetable oil, creating a more efficient and valuable crop.Thelen and Yajin Ye, a postdoctoral fellow in Thelen's lab at MU, used the gene editing tool CRISPR to "knock out" a family of genes they have found to be responsible for regulating fatty acid production in the leaves of Arabidopsis, a plant regularly used by researchers to study plant biochemistry. The results were recently published in the journal "We know that plants synthesize fatty acids when provided light," said Thelen, who has dual appointments in the College of Agriculture, Food and Natural Resources and the Bond Life Sciences Center. "This study taught us that there are three proteins that restrain this process in leaves, and that we can turn off their cognate genes using CRISPR. That frees up the plant to produce higher amounts of triacylglycerol in the leaves rather than just the seed."Thelen said this method could lead to greater and cheaper production of vegetable oils, and the possibility of dual uses for leafy crops like sorghum and soybeans could place less of a burden on making a higher-oil seed. That burden often has undesirable consequences -- including a decrease in protein, which is the principal commodity in soybean seeds. His lab is now in the process of further testing the method on crops to confirm its viability.If anyone seemed prepared to make this discovery, it was Jay Thelen. Hailing from the small town of Seward, Nebraska, Thelen has been seriously pursuing science research since high school more than three decades ago, when he found himself in the classroom of Jim Landon, a nationally renowned science teacher with an unorthodox style."We got out of the classroom and did ecological experiments on nature reserves," Thelen said. "We went hiking, assisted with invasive species studies and even helped out on prehistoric digs. We uncovered mastodon bones. It was really impactful stuff."Landon took Thelen under his wing, arranging for him to participate in university-caliber research at the University of Nebraska during the summer and -- once in a while -- on weekends during the school year. Landon, now in his seventies and enjoying retirement in the state of Washington, remembers his former student clearly."Jay was a great kid; very inquisitive," Landon said. "I remember when he was chosen to present his research at the 40th International Science and Engineering Fair in Pittsburgh in 1989. Only a handful of students from Nebraska, Kansas and Oklahoma were selected, and I can still see him standing up there and doing his presentation. In high school, when the athletes sometimes get all the glory, it was great to see Jay take the initiative to do research and even better to see that initiative rewarded."Teacher and student have gone on to separate career paths, but they still talk once in a while, reflecting the impact each had on the other. Thelen credits Landon for sparking his fascination with science, while Landon speaks lavishly of how students like Thelen have fueled his passion for teaching throughout his career."It just amazes me what the kids I've taught have gone on to accomplish," Landon said. "For Jay's research to be published in a journal as prestigious as Despite his success, Thelen has no plans to slow down when it comes to the research that drives his love of science."For me, understanding how plant metabolism is regulated is an itch that needs to be scratched," Thelen said. "Plants are the original 'green' factories for food, chemical feedstock and fuel production. Discovering new metabolic constraints and leveraging these findings to help us adapt to a warming planet -- that's something that motivates me, and there's still much more to be done."
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Agriculture & Food
| 2,020 |
December 14, 2020
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https://www.sciencedaily.com/releases/2020/12/201214164339.htm
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Ancient DNA continues to rewrite corn's 9,000-year society-shaping history
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Some 9,000 years ago, corn as it is known today did not exist. Ancient peoples in southwestern Mexico encountered a wild grass called teosinte that offered ears smaller than a pinky finger with just a handful of stony kernels. But by stroke of genius or necessity, these Indigenous cultivators saw potential in the grain, adding it to their diets and putting it on a path to become a domesticated crop that now feeds billions.
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Despite how vital corn, or maize, is to modern life, holes remain in the understanding of its journey through space and time. Now, a team co-led by Smithsonian researchers have used ancient DNA to fill in a few of those gaps.A new study, which reveals details of corn's 9,000-year history, is a prime example of the ways that basic research into ancient DNA can yield insights into human history that would otherwise be inaccessible, said co-lead author Logan Kistler, curator of archaeogenomics and archaeobotany at the Smithsonian's National Museum of Natural History."Domestication -- the evolution of wild plants over thousands of years into the crops that feed us today -- is arguably the most significant process in human history, and maize is one of the most important crops currently grown on the planet," Kistler said. "Understanding more about the evolutionary and cultural context of domestication can give us valuable information about this food we rely on so completely and its role in shaping civilization as we know it."In the Dec. 14 issue of the journal the "We show that humans were carrying maize from South America back towards the domestication center in Mexico," Kistler said. "This would have provided an infusion of genetic diversity that may have added resilience or increased productivity. It also underscores that the process of domestication and crop improvement doesn't just travel in a straight line."Humans first started selectively breeding corn's wild ancestor teosinte around 9,000 years ago in Mexico, but partially domesticated varieties of the crop did not reach the rest of Central and South America for another 1,500 and 2,000 years, respectively.For many years, conventional thinking among scholars had been that corn was first fully domesticated in Mexico and then spread elsewhere. However, after 5,000-year-old cobs found in Mexico turned out to only be partially domesticated, scholars began to reconsider whether this thinking captured the full story of corn's domestication.Then, in a landmark 2018 study led by Kistler, scientists used ancient DNA to show that while teosinte's first steps toward domestication occurred in Mexico, the process had not yet been completed when people first began carrying it south to Central and South America. In each of these three regions, the process of domestication and crop improvement moved in parallel but at different speeds.In an earlier effort to home in on the details of this richer and more complex domestication story, a team of scientists including Kistler found that 4,300-year-old corn remnants from the Central American El Gigante rock shelter site had come from a fully domesticated and highly productive variety.Surprised to find fully domesticated corn at El Gigante coexisting in a region not far from where partially domesticated corn had been discovered in Mexico, Kistler and project co-lead Douglas Kennett, an anthropologist at the University of California, Santa Barbara, teamed up to genetically determine where the El Gigante corn originated."El Gigante rock shelter is remarkable because it contains well-preserved plant remains spanning the last 11,000 years," Kennett said. "Over 10,000 maize remains, from whole cobs to fragmentary stalks and leaves, have been identified. Many of these remains date late in time, but through an extensive radiocarbon study, we were able to identify some remains dating to as early as 4,300 years ago."They searched the archaeological strata surrounding the El Gigante rock shelter for cobs, kernels or anything else that might yield genetic material, and the team started working toward sequencing some of the site's 4,300-year-old corn samples -- the oldest traces of the crop at El Gigante.Over two years, the team attempted to sequence 30 samples, but only three were of suitable quality to sequence a full genome. The three viable samples all came from the more recent layer of the rock shelter's occupation -- carbon dated between 2,300 and 1,900 years ago.With the three sequenced genomes of corn from El Gigante, the researchers analyzed them against a panel of 121 published genomes of various corn varieties, including 12 derived from ancient corn cobs and seeds. The comparison revealed snippets of genetic overlap between the three samples from the Honduran rock shelter and corn varieties from South America."The genetic link to South America was subtle but consistent," Kistler said. "We repeated the analysis many times using different methods and sample compositions but kept getting the same result."Kistler, Kennett and their co-authors at collaborating institutions, including Texas A&M University, Pennsylvania State University as well as the Francis Crick Institute and the University of Warwick in the United Kingdom, hypothesize that the reintroduction of these South American varieties to Central America may have jump-started the development of more productive hybrid varieties in the region.Though the results only cover the El Gigante corn samples dated to around 2,000 years ago, Kistler said the shape and structure of the cobs from the roughly 4,000-year-old layer suggests they were nearly as productive as those he and his co-authors were able to sequence. To Kistler, this means the blockbuster crop improvement likely occurred before rather than during the intervening 2,000 years or so separating these archaeological layers at El Gigante. The team further hypothesizes that it was the introduction of the South American varieties of corn and their genes, likely at least 4,300 years ago, which may have increased the productivity of the region's corn and the prevalence of corn in the diet of the people who lived in the broader region, as discovered in a recent study led by Kennett."We are starting to see a confluence of data from multiple studies in Central America indicating that maize was becoming a more productive staple crop of increasing dietary importance between 4,700 and 4,000 years ago," Kennett said.Taken together with Kennett's recent study, these latest findings suggest that something momentous may have occurred in the domestication of corn about 4,000 years ago in Central America, and that an injection of genetic diversity from South America may have had something to do with it. This proposed timing also lines up with the appearance of the first settled agricultural communities in Mesoamerica that ultimately gave rise to great civilizations in the Americas, the Olmec, Maya, Teotihuacan and the Aztec, though Kistler hastened to point out this idea is still relegated to speculation."We can't wait to dig into the details of what exactly happened around the 4,000-year mark," Kistler said. "There are so many archaeological samples of maize which haven't been analyzed genetically. If we started testing more of these samples, we could start to answer these lingering questions about how important this reintroduction of South American varieties was."Funding and support for this research were provided by the Smithsonian, National Science Foundation, Pennsylvania State University and the Francis Crick Institute.
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Agriculture & Food
| 2,020 |
December 14, 2020
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https://www.sciencedaily.com/releases/2020/12/201214104719.htm
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What makes peppers blush?
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Visually, this transformation is clearly visible in the colour change from green to orange or red. The team documented the process in detail and globally at the protein level and published the results in
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Because of their aromatic taste and high concentrations of health-promoting ingredients such as vitamin C and antioxidant provitamin A (carotenoids), bell peppers, scientifically Capsicum annuum, belong to the most popular vegetables. The ripening process in peppers proceeds from photosynthetically active fruits with high chlorophyll and starch content to non-photosynthetic fruits that are rich in carotenoids. Essential steps of this transformation take place in typical plant cell organelles, the so-called plastids.Progenitor organelles, the so-called proplastids, are the first step. They are not yet differentiated and transform into different plastids depending on tissue type and environmental signals. In many fruit and vegetable varieties, the chromoplasts develop from them. "They got their name because of their frequently bright colours," explains Sacha Baginsky. In pepper fruits, proplastids initially turn into photosynthetically active chloroplasts, from which the carotenoid-rich chromoplasts develop through the breakdown of chlorophyll and the photosynthesis machinery as the fruit ripens.The same applies to tomatoes, although there is a crucial difference to peppers: tomatoes belong to the climacteric fruits that continue to ripen after harvesting. Biochemically, this process is characterised by an enormous increase in respiratory activity with high oxygen consumption, the so-called climacteric. This is not the case with peppers. "The green peppers frequently available in supermarkets are unripe," says Sacha Baginsky. They still carry chlorophyll-rich chloroplasts and, when the pepper is fresh, also contain a large amount of the photosynthetic storage substance starch. "Our data now show several differences in chromoplast differentiation between peppers and tomatoes at the molecular level, which provides insights into the different metabolism of climacteric and non-climacteric fruits," says the biologist.One example is energy metabolism: the protein PTOX -- acronym of plastid terminal oxidase -- that generates water by transferring electrons to oxygen during carotenoid production is only present in small quantities in peppers. This might result in lower oxygen consumption and could be associated with increased ATP synthesis. Chromoplasts use modules of photosynthetic electron transport for ATP synthesis, which in peppers is at least partially carried out via the so-called cytochrome b6/f complex and plastocyanin that in peppers is present in large quantities -- in contrast to tomatoes. Small amounts of PTOX in peppers could mean that more ATP can be produced as more electrons from carotenoid production flow via this pathway to a previously unknown oxidase."This is just one example of several, sometimes subtle differences in the metabolism of tomato and pepper chromoplasts," explains Sacha Baginsky. "Our data provide a new approach to understanding chromoplast differentiation, which we now intend to explore in more depth." For example, the Bochum-based team will use a system described by a Spanish group in which chromoplast differentiation in leaves is induced by the production of a single enzyme. This could indicate ways to produce carotenoids more effectively and sustainably in plants. The data collected so far are publicly available through the Pride database.
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Agriculture & Food
| 2,020 |
December 11, 2020
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https://www.sciencedaily.com/releases/2020/12/201211115452.htm
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Male weeds may hold key to their own demise
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Scientists are getting closer to finding the genes for maleness in waterhemp and Palmer amaranth, two of the most troublesome agricultural weeds in the U.S.
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Finding the genes could enable new "genetic control" methods for the weeds, which, in many places, no longer respond to herbicides."If we knew which genes control maleness and we could make those genes proliferate within the population, every plant in the field would be a male after a few generations, and theoretically, the population would crash," says Pat Tranel, professor and associate head in the Department of Crop Sciences at the University of Illinois and lead author on a study in Tranel and his colleagues had previously identified molecular markers associated with the male genomic region. After sequencing male genomes for both species, the researchers were able to use those markers to zero in on the male-specific region. Now, they are within 120 to 150 genes of finding their target."We're confident most of those 120 or so genes are probably doing nothing. It's just stuff that's accumulated in that region of the genome," Tranel says. "If I had to guess, I'd say maybe 10 of them are actually doing something relevant."Narrowing down the genes related to gender in these weeds could have practical value for control, but the study also sheds light on the phenomenon of dioecy -- male and female sexual organs on separate individuals -- more generally. The vast majority of animals are dioecious, but it's rare in plants. More than 90% of flowering plants have both sexual organs on the same individual, and often within the same flower.Waterhemp and Palmer amaranth, however, are dioecious.Dioecy means it's impossible for a plant to self-pollinate; instead, female gametes must be fertilized by male pollen from another plant. That's a good thing for ensuring genetic diversity in a population. And it's likely what has made waterhemp and Palmer amaranth so successful at evading the detrimental effects of multiple herbicides."To date, waterhemp and Palmer amaranth have evolved resistance to herbicides spanning seven and eight modes of action, respectively. Dioecious reproduction results in all these resistance traits being mixed and matched within individuals. This mixing has allowed populations of both species to combine multiple herbicide resistances, leaving producers with few effective herbicide choices," Tranel says.Understanding the rare phenomenon of dioecy in plants can help scientists piece together how traits are inherited from each parent, and to understand how the phenomenon evolves.Unlike in animals, in which dioecy is thought to have evolved just once, scientists believe dioecy in plants has evolved numerous times. And, according to Tranel's study, it appears to have evolved independently in waterhemp and Palmer amaranth, two very closely related species."I'm not ready to say we absolutely know they evolved separately, but all the information we found supports that idea. Only two of the 120-150 genes were similar to each other across the two species," Tranel says.One of those shared genes, Florigen, helps plants respond to day length by initiating flowering. Tranel doesn't know yet whether it determines the gender of flowers, but he's intrigued that it showed up in the male-specific Y region for both species."We don't know for sure, but maybe it's involved with males flowering earlier than females. That could be advantageous to males because then they'd be shedding pollen when the first females become receptive. So if, in fact, Palmer and waterhemp really did evolve dioecy separately, but both acquired this Florigen gene for a fitness advantage, that would be a cool example of parallel evolution."Tranel hopes to narrow down the male-specific Y region in both species even further to isolate the genes that determine maleness. There's no guarantee a genetic control solution will be developed once those genes are identified -- Tranel would likely need to attract industry partners for that -- but having such a tool is not as far off as it once was.
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Agriculture & Food
| 2,020 |
December 9, 2020
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https://www.sciencedaily.com/releases/2020/12/201209094221.htm
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Tomatoes offer affordable source of Parkinson's disease drug
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Scientists have produced a tomato enriched in the Parkinson's disease drug L-DOPA in what could become a new, affordable source of one of the world's essential medicines.
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The development of the genetically modified (GM) tomato has implications for developing nations where access to pharmaceutical drugs is restricted.This novel use of tomato plants as a natural source of L-DOPA also offers benefits for people who suffer adverse effects -- including nausea and behavioral complications -- of chemically synthesised L-DOPA .Tomato -- was chosen as a widely cultivated crop that can be used for scaled up production and potentially offering a standardised and controlled natural source of L-DOPA .The John Innes Centre led team modified the tomato fruit by introducing a gene responsible for the synthesis of L-DOPA in beetroot where it functions in the production of the pigments betalains.L-DOPA is produced from tyrosine, an amino acid found in many foods. The research team inserted a gene encoding a tyrosinase, an enzyme that uses tyrosine to build molecules such as L-DOPA . This elevated the level of L-DOPA specifically in the fruit part of the plant and led to higher yields than those associated with L-DOPA production in the whole plant.The levels achieved in the tomato fruit -- 150mg of L-DOPA per kg of tomatoes -- were comparable those observed in other L-DOPA accumulating plants -- without some of the known drawbacks that have hampered plant metabolic production of the drug previously.The aim now is to create a production pipeline where L-DOPA is extracted from the tomatoes and purified into the pharmaceutical product.Professor Cathie Martin (FRS), corresponding author of the study explains: "The idea is that you can grow tomatoes with relatively little infrastructure. As GMOs (genetically modified organisms) you could grow them in screen houses, controlled environments with very narrow meshes, so you would not have pollen escape through insects."Then you could scale up at relatively low cost. A local industry could prepare L-DOPA from tomatoes because it's soluble and you can do extractions. Then you could make a purified product relatively low tech which could be dispensed locally."Parkinson's disease is a growing problem in developing countries where many people cannot afford the daily $2 price of synthetic L-DOPA .L-DOPA is an amino acid precursor of the neuro-chemical dopamine and is used to compensate for the depleted supply of dopamine in Parkinson's disease patients.Also known as Levodopa, L-DOPA has been the gold standard therapy for Parkinson's disease since its establishment as a drug in 1967. It is one of the essential medicines declared by the World Health Organisation (WHO) and its market value is in the hundreds of billions of dollars.The most common form of the drug is produced by chemical synthesis, but natural sources are also available. Only a few plants have been reported to contain measurable quantities of the molecule, mainly in seeds.The most studied is the velvet bean, Mucuna pruriens, which contains up to 10% L-DOPA in its seeds. But this is problematic because the plant is covered in urticating hairs that contain mucunian that can cause irritation and allergic reactions in field workers who harvest the crop. The beans themselves cause elevated levels of tryptamines that can cause hallucinations in Parkinsons disease patients."We have demonstrated that the use of the tyrosinase-expressing tomatoes as a source of L-DOPA is possible. It's a further demonstration of tomato as a strong option for synthetic biology. Additionally, there were surprising beneficial effects including improvement in shelf-life and raised levels of amino-acids that we can investigate," says first author Dr Dario Breitel.
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Agriculture & Food
| 2,020 |
December 4, 2020
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https://www.sciencedaily.com/releases/2020/12/201204110239.htm
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How bean plants fend off famished foes
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For a caterpillar, a green leaf can make a nice meal. But to the plant itself, it's an attack. And very hungry caterpillars can do a lot of damage as they eat their way through life.
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Plants can fight back, unleashing an array of chemical defenses to discourage wayward foragers -- from releasing chemicals that attract caterpillar predators to secreting compounds that make the plant taste so foul that desperate caterpillars resort to cannibalism. But scientists know little about how plants detect these attacks and marshal defenses.In a paper published Nov. 23 in the "Despite chemical controls, crop yield losses to pests and disease generally range from 20-30% worldwide. Yet many varieties are naturally resistant or immune to specific pests," said lead author Adam Steinbrenner, a UW assistant professor of biology. "Our findings are the first to identify an immune recognition mechanism that sounds the alarm against chewing insects."The receptor is a protein known by the acronym INR. The team showed that, in response to both leaf wounds and the presence of a protein fragment specific to caterpillar saliva, the cowpea's INR protein boosts the production of ethylene, a hormone that plants often produce in response to munching by herbivores and other types of environmental stress. The protein fragment in caterpillar spit that elicited this response, Vu-IN, is actually a fragment of a cowpea protein, which gets broken down by the caterpillar as it dines on cowpea leaves.Researchers have fewer methods to study cowpeas compared to other plants. So to learn more cellular details about INR's function, they popped the gene for INR into tobacco plants. These tobacco plants, when exposed to Vu-IN, increased production of ethylene as well as reactive oxygen species, another anti-herbivore defense that consists of chemically reactive forms of oxygen. In addition, the team's experiments showed that a tobacco-eating caterpillar -- the beet armyworm -- munched less on INR-harboring tobacco plants than plants without INR.The research shows that plants like the cowpea sound the alarm only after their cells detect specific molecules associated with herbivory. Vu-IN is a trigger for cowpea defenses. Other plants likely have different molecular triggers for their own defensive systems, the researchers believe.Understanding how plants activate their immune systems could help scientists develop more effective strategies to defend crop plants against hungry insects.
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Agriculture & Food
| 2,020 |
December 3, 2020
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https://www.sciencedaily.com/releases/2020/12/201203200559.htm
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Household-grown food leads to improved health for children
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Children grow taller in rural households where their mothers are supported to grow their own food -- according to new research from the University of East Anglia (UEA).
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The research, which looked at households in low- and middle-income countries, showed growing their own food helped mothers to prevent stunting, wasting and underweight in their children. Their children's food was more varied, meaning they had access to different classes of food nutrients.The study, 'Impact of home food production on nutritional blindness, stunting, wasting, underweight and mortality in children: a systematic review and meta-analysis of controlled trials', is published today in the journal The team from the Norwich Medical School and the School of International Development at UEA analysed studies that introduced women to home farming in African and Asian countries including Nigeria, Ghana, India, Cambodia, Mozambique, Uganda, Kenya and Burkina Faso. The home farming included growing brightly coloured Vitamin A-rich fruit and vegetables such as sweet potatoes, and sometimes also included chicken farming.The health of these women's children was assessed over the next year or more. The children of the women who were introduced to home farming did better than children of other women, in that they were less likely to suffer from wasting, stunting and underweight.No studies, however, reported on children's eye health. The researchers concluded that high-quality trials are needed to assess the impact of home food production on nutritional blindness in children, especially in rural areas.Xerophthalmia is abnormal dryness and inflammation of the eye, leading to irreversible blindness, and is predominantly caused by an insufficient intake of Vitamin A. Vitamin A supplementation prevents children from dying and improves their health in other ways, such as reducing the risk from measles. Many countries run Vitamin A supplementation programmes for children, but these often leave out children in rural areas.Approximately 250 million preschool children are still Vitamin A deficient, according to the World Health Organization. Vitamin A deficiency is the main global cause of preventable childhood blindness with about 2.8 million preschool-age children at risk of blindness. Vitamin A deficiency also increases the risk of mortality from other childhood diseases, such as diarrhea and measles, and plays a significant role in normal immune function. It remains one of the most prevalent micronutrient deficiencies globally.Mrs Chizoba Bassey, a postgraduate researcher in UEA's Norwich Medical School, led the team conducting the systematic review.Mrs Bassey said: "Well-evidenced interventions such as Vitamin A supplementation programmes should be adopted and expanded to children at greatest risk to prevent nutritional blindness."Currently there is not enough evidence of the effects of home gardening on xerophthalmia, night blindness or mortality in children, but the evidence from our research shows that if women take up home gardening the risk of stunting, wasting and underweight in their children is reduced."The introduction of home food production may be appropriate in areas where nutritional blindness, underweight, stunting and wasting are prevalent and where more intensive nutritional support, such as Vitamin A supplementation programmes, are not available."Home farming may help to achieve sustainability in controlling Vitamin A deficiency and can complement Vitamin A supplementation programmes where they are available.The research was carried out in conjunction with colleagues from the Nutrition and Dietetics department at the Norfolk & Norwich University Hospital.'Impact of home food production on nutritional blindness, stunting, wasting, underweight and mortality in children: a systematic review and meta-analysis of controlled trials', is published December 4, 2020 in the journal
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Agriculture & Food
| 2,020 |
December 2, 2020
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https://www.sciencedaily.com/releases/2020/12/201202192758.htm
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Replacing red meat with plant foods may reduce the risk of heart disease
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Replacing red meat with high quality plant foods such as beans, nuts, or soy may be associated with a modestly reduced risk of coronary heart disease (CHD), suggests a study published by
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Substituting whole grains and dairy products for total red meat, and eggs for processed red meat, might also reduce this risk.Substantial evidence suggests that high consumption of red meat, especially processed red meat, such as bacon, hot dogs, sausages and salami, is associated with an increased risk of death and major chronic diseases, including coronary heart disease.Studies that show inconsistent results often fail to compare red meat with similar protein and energy sources.To address these problems in study design and analysis, a team of US researchers examined the relation between total, processed, and unprocessed red meat and risk of CHD and estimate the effects of substituting other protein sources for red meat with CHD risk.Their findings are based on data from 43,272 US men (average age 53) from the Health Professionals Follow-Up Study who were free from cardiovascular disease and cancer when they enrolled.Participants filled in a detailed diet questionnaire in 1986 and every four years thereafter, up to 2016, and provided information on their medical history and lifestyle.Medical records were used to track CHD events (fatal and non-fatal) over this 30-year period. During this time, 4,456 CHD events were documented of which 1,860 were fatal.After taking account of other cardiovascular disease risk factors, the researchers found that for every one serving per day, total red meat was associated with a modest (12%) higher risk of CHD. Similar associations were seen for unprocessed (11% higher risk) and processed red meat (15% higher risk).However, compared with red meat, intake of one serving per day of combined plant protein sources, including nuts, legumes (such as peas, beans and lentils), and soy was associated with a 14% lower risk of CHD.This risk was lower still (18%) among men over the age of 65, and when compared with processed red meat (17%).Substituting whole grains and dairy products (such as milk, cheese and yoghurt) for total red meat and eggs for processed red meat were also associated with lower CHD risk. This association was particularly strong among younger men, in whom the replacement of red meat with egg was associated with a 20% lower risk of CHD.Replacing red meat with total fish was not associated with CHD risk. But the researchers say this could be due to cooking method (ie. deep frying) and the fact that this food group also included processed fish products.This is an observational study, so can't establish cause, and despite adjusting for important personal and lifestyle factors, the researchers can't rule out the possibility that other unmeasured factors might have influenced their results.What's more, study participants were mainly white health professionals so the findings may not be more widely applicable.Nevertheless, this was a large study with repeated measures of diet during 30 years of follow-up, suggesting that the findings withstand scrutiny.As such, they say their study shows that greater intakes of total, unprocessed, and processed red meat were associated with a higher risk of CHD, independent of other dietary and non-dietary cardiovascular disease risk factors.Substituting whole grains or dairy products for total red meat and substituting eggs for processed red meat were also associated with a lower CHD risk, they add."These findings are consistent with the effects of these foods on low density lipoprotein cholesterol levels and support a health benefit of limiting red meat consumption and replacement with plant protein sources," they explain.This would also have important environmental benefits, they conclude.
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Agriculture & Food
| 2,020 |
December 2, 2020
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https://www.sciencedaily.com/releases/2020/12/201202114455.htm
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Plant-inspired alkaloids protect rice, kiwi and citrus from harmful bacteria
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Plants get bacterial infections, just as humans do. When food crops and trees are infected, their yield and quality can suffer. Although some compounds have been developed to protect plants, few of them work on a wide variety of crops, and bacteria are developing resistance. Now, researchers reporting in ACS'
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Currently, no effective prevention or treatment exists for some plant bacterial diseases, including rice leaf blight, kiwifruit canker and citrus canker, which result in substantial agricultural losses every year. Scientists are trying to find new compounds that attack bacteria in different ways, reducing the chances that the microbes will develop resistance. Plant compounds called tetrahydro-β-carboline (THC) alkaloids are known to have antitumor, anti-inflammatory, antifungal, antioxidant and antiviral activities. So, Pei-Yi Wang, Song Yang and colleagues wondered whether derivatives of THC alkaloids could help fight plant bacterial diseases.The researchers used a THC alkaloid called eleagnine, which is produced by Russian olive trees and some other plants, as a scaffold. To this framework, they added different chemical groups to make a series of new compounds, two of which efficiently killed three strains of plant pathogenic bacteria in liquid cultures. The team then tested the two compounds on rice, kiwi and citrus plant twigs and leaves and found that the new alkaloids could both prevent and treat bacterial infections. The researchers determined that the compounds worked by increasing levels of reactive oxygen species in the bacteria, which caused the bacterial cells to die.
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Agriculture & Food
| 2,020 |
December 1, 2020
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https://www.sciencedaily.com/releases/2020/12/201201124152.htm
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Tweaking carotenoid genes helps tomatoes bring their A-game
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Cooked, fresh, sun-dried, or juiced, whichever way you prefer them, tomatoes are arguably one of the most versatile fruits on the planet -- and yes, despite mainly being used in savory dishes, tomatoes really are a fruit.
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The popularity of tomatoes has led to the development of more than 10,000 cultivars of various sizes, shapes, and hues. Interestingly though, there is little genetic diversity among modern tomato varieties. This lack of diversity, coupled with the fact that many traits are controlled by multiple genes, makes improving plant yield and quality a major challenge for tomato breeders.But in a study published this week in "The tomato was the first genetically modified food to be approved for human consumption," says senior author of the study Professor Hiroshi Ezura. "However, many early transgenic varieties contained genes derived from other species, raising safety concerns among consumers. Therefore, coupled with the fact that most transgenic varieties showed only moderate improvements in quality, tomato breeding has, for the most part, moved away from transgenics."Unlike traditional genetic modification, modern gene editing techniques leave no trace in the genome and can introduce small changes within a native gene, mimicking natural variation.Tomatoes contain relatively high levels of carotenoids, the yellow, red, and orange pigments found in many plants. Carotenoids are precursors to vitamin A and demonstrate antioxidant and anti-cancer properties, making them hugely important to human nutrition. Several natural mutations that enhance carotenoid accumulation in tomatoes have been documented, but their introduction into commercial varieties is a complicated and time-consuming prospect.The University of Tsukuba-led team therefore set about reproducing carotenoid accumulation mutations in tomatoes using gene editing technology."Single nucleotide changes in individual tomato genes had previously been achieved using Target-AID gene editing technology," explains Professor Ezura. "However, we designed a system whereby changes were simultaneously introduced into three genes associated with carotenoid accumulation."Among 12 resulting tomato lines, 10 contained mutations in all three target genes. Further examination of two lines with the dark green fruit and purple roots of natural carotenoid accumulation mutants revealed high levels of carotenoids, particularly lycopene, in the gene-edited plants.Professor Ezura explains, "This shows that it is possible to improve multigenic plant quality traits using gene editing technology, and opens up a whole range of options for improving the yield, shelf-life, nutrient content, and disease resistance of different crop plants, which has obvious benefits for both human health and the environment."
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Agriculture & Food
| 2,020 |
November 25, 2020
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https://www.sciencedaily.com/releases/2020/11/201125135131.htm
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Ancient blanket made with 11,500 turkey feathers
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The ancient inhabitants of the American Southwest used around 11,500 feathers to make a turkey feather blanket, according to a new paper in the
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A team led by Washington State University archaeologists analyzed an approximately 800-year-old, 99 x 108 cm (about 39 x 42.5 inches) turkey feather blanket from southeastern Utah to get a better idea of how it was made. Their work revealed thousands of downy body feathers were wrapped around 180 meters (nearly 200 yards) of yucca fiber cord to make the blanket, which is currently on display at the Edge of the Cedars State Park Museum in Blanding, Utah.The researchers also counted body feathers from the pelts of wild turkeys purchased from ethically and legally compliant dealers in Idaho to get an estimate of how many turkeys would have been needed to provide feathers for the blanket. Their efforts show it would have taken feathers from between four to 10 turkeys to make the blanket, depending on the length of feathers selected."Blankets or robes made with turkey feathers as the insulating medium were widely used by Ancestral Pueblo people in what is now the Upland Southwest, but little is known about how they were made because so few such textiles have survived due to their perishable nature," said Bill Lipe, emeritus professor of anthropology at WSU and lead author of the paper. "The goal of this study was to shed new light on the production of turkey feather blankets and explore the economic and cultural aspects of raising turkeys to supply the feathers."Clothing and blankets made of animal hides, furs or feathers are widely assumed to have been innovations critical to the expansion of humans into cold, higher latitude and higher elevation environments, such as the Upland Southwest of the United States where most of the early settlements were at elevations above 5,000 feet.Previous work by Lipe and others shows turkey feathers began to replace strips of rabbit skin in construction of twined blankets in the region during the first two centuries C.E. Ethnographic data suggest the blankets were made by women and were used as cloaks in cold weather, blankets for sleeping and ultimately as funerary wrappings."As ancestral Pueblo farming populations flourished, many thousands of feather blankets would likely have been in circulation at any one time," said Shannon Tushingham, a co-author on the study and assistant professor of anthropology at WSU. "It is likely that every member of an ancestral Pueblo community, from infants to adults, possessed one."Another interesting finding of the study was the turkey feathers used by the ancestral Pueblo people to make garments were most likely painlessly harvested from live birds during natural molting periods. This would have allowed sustainable collection of feathers several times a year over a bird's lifetime, which could have exceeded 10 years. Archeological evidence indicates turkeys were generally not used as a food source from the time of their domestication in the early centuries C.E. until the 1100s and 1200s C.E., when the supply of wild game in the region had become depleted by over-hunting.Prior to this period, most turkey bones reported from archaeological sites are whole skeletons from mature birds that were intentionally buried, indicating ritual or cultural significance. Such burials continued to occur even after more turkeys began to be raised for food."When the blanket we analyzed for our study was made, we think in the early 1200s C.E., the birds that supplied the feathers were likely being treated as individuals important to the household and would have been buried complete," Lipe said. "This reverence for turkeys and their feathers is still evident today in Pueblo dances and rituals. They are right up there with eagle feathers as being symbolically and culturally important."In the long run, the researchers said their hope is the study will help people appreciate the importance of turkeys to Native American cultures across the Southwest."Turkeys were one of the very few domesticated animals in North America until Europeans arrived in the 1500s and 1600s," Tushingham said. "They had and continue to have a very culturally significant role in the lives of Pueblo people, and our hope is this research helps shed light on this important relationship."
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Agriculture & Food
| 2,020 |
November 25, 2020
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https://www.sciencedaily.com/releases/2020/11/201125122323.htm
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Novel haplotype-led approach to increase the precision of wheat breeding
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Wheat researchers at the John Innes Centre are pioneering a new technique that promises to improve gene discovery for the globally important crop.
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Crop breeding involves assembling desired combinations of traits that are defined by underlying genetic variation. Part of this genetic variation often stays the same between generations, with certain genes being inherited together. These blocks of genes -- very rarely broken up in genetic recombination -- are called haplotype blocks. These haplotypes are the units that breeders switch and select between plants to create new crop lines.In the new study which appears in They defined shared haplotype-blocks across the 15 bread wheat cultivars assembled in the 10+ Wheat Genome Project a major international collaboration published today in To illustrate the application of this haplotype-led approach to support crop improvement, they focused on a specific region of the wheat genome on chromosome 6A.Through detailed genetic studies and extensive field experiments, they showed that UK breeders are maintaining multiple genes as an intact chromosome 6A haplotype to maximise the expression of desirable traits including flowering time and yield.Given the low diversity on chromosome 6A, they tested the haplotype approach to discover and introduce novel haplotypes from wheat landraces not subjected to modern breeding.Combining haplotype knowledge, genetics and field studies, they identified three novel haplotypes in the landraces associated with improved productivity traits in UK environments.As these haplotypes are not present in modern germplasm, they represent novel variations that could be targeted for yield improvement in elite cultivars, using modern genomic tools.Lead author Dr Jemima Brinton says: "We used strict criteria to distinguish these shared haplotype blocks from near-identical sequences. We argue that this stringency is essential for crop improvement. The breeding process is poised to undergo an improvement in precision and efficiency through haplotype-led breeding."The knowledge generated in the study directly affect the breeding and discovery process by allowing scientists to:To make the work more accessible to readers, scientists and breeders, the group developed a new haplotype visualisation interface at
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Agriculture & Food
| 2,020 |
November 25, 2020
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https://www.sciencedaily.com/releases/2020/11/201125114401.htm
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Landmark study generates first genomic atlas for global wheat improvement
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In a landmark discovery for global wheat production, a University of Saskatchewan-led international team has sequenced the genomes for 15 wheat varieties representing breeding programs around the world, enabling scientists and breeders to much more quickly identify influential genes for improved yield, pest resistance and other important crop traits.
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The research results, just published in "It's like finding the missing pieces for your favorite puzzle that you have been working on for decades," said project leader Curtis Pozniak, wheat breeder and director of the USask Crop Development Centre (CDC). "By having many complete gene assemblies available, we can now help solve the huge puzzle that is the massive wheat pan-genome and usher in a new era for wheat discovery and breeding."Scientific groups across the global wheat community are expected to use the new resource to identify genes linked to in-demand traits, which will accelerate breeding efficiency."This resource enables us to more precisely control breeding to increase the rate of wheat improvement for the benefit of farmers and consumers, and meet future food demands," Pozniak said.One of the world's most cultivated cereal crops, wheat plays an important role in global food security, providing about 20 per cent of human caloric intake globally. It's estimated wheat production must increase by more than 50 per cent by 2050 to meet an increasing global demand.In 2018 as part of another international consortium, USask researchers played a key role in decoding the genome for the bread wheat variety Chinese Spring, the first complete wheat genome reference and a significant technical milestone. The findings were published in the journal "Now we have increased the number of wheat genome sequences more than 10-fold, enabling us to identify genetic differences between wheat lines that are important for breeding," Pozniak said. "We can now compare and contrast the full complement of the genetic differences that make each variety unique."Nils Stein of the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) and project co-leader from Germany said, "Given the significant impact of the Chinese Spring reference genome on research and application, it is a major achievement that just two years later we are providing additional sequence resources that are relevant to wheat improvement programs in many different parts of the world."The 10+ Genome study represents the start of a larger effort to generate thousands of genome sequences of wheat, including genetic material brought in from wheat's wild relatives.The research team was able to track the unique DNA signatures of genetic material incorporated into modern cultivars from several of wheat's undomesticated relatives by breeders over the century."These wheat relatives have been used by breeders to improve disease resistance and stress resistance of wheat," said Pozniak. "One of these relatives contributed a DNA segment to modern wheat that contains disease-resistant genes and provides protection against a number of fungal diseases. Our collaborators from Kansas State University and CIMMYT (Mexico) showed that this segment can improve yields by as much as 10 per cent. Since breeding is a continual improvement process, we can continue to cross plants to select for this valuable trait."Pozniak's team, in collaboration with scientists from Agriculture and Agri-Food Canada and National Research Council of Canada, also used the genome sequences to isolate an insect-resistant gene (called Sm1) that enables wheat plants to withstand the orange wheat blossom midge, a pest which can cause more than $60 million in annual losses to Western Canadian producers."Understanding a causal gene like this is a game-changer for breeding because you can select for pest resistance more efficiently by using a simple DNA test than by manual field testing," Pozniak said.The USask team also included the paper's first author Sean Walkowiak (formerly with Pozniak's team and now with the Canadian Grain Commission), computer scientist Carl Gutwin who developed visualization software and a user-friendly database to compare the genome sequences, and Andrew Sharpe, director of genomics and bioinformatics at the USask Global Institute for Food Security, who did sequencing work through the Omics and Precision Agriculture Laboratory (OPAL), a state-of-the-art laboratory that provides genomics, phenomics and bioinformatics services.The 10+ Genome Project was sanctioned as a top priority by the Wheat Initiative, a co-ordinating body of international wheat researchers."This project is an excellent example of co-ordination across leading research groups around the globe. Essentially every group working in wheat gene discovery, gene analysis and deployment of molecular breeding technologies will use the resource," said Wheat Initiative Scientific Co-ordinator Peter Langridge.Canadian funding came from the Canadian Triticum Applied Genomics (CTAG2) research project funded by Genome Canada, Genome Prairie, the Western Grains Research Foundation, Government of Saskatchewan, Saskatchewan Wheat Development Commission, Alberta Wheat Commission, Viterra, Manitoba Wheat and Barley Growers Association, and the Canada First Research Excellence Fund through USask's Plant Phenotyping and Imaging Research Centre (P2IRC) initiative."This project is a prime example of how genomics can support increased resilience in food production and strengthen Canada's export leadership," said Genome Canada President and CEO Rob Annan."Deploying genomics to adapt agricultural production to climate change, address food and nutritional insecurity, and improve crop health is good for farmers and consumers, and our economy will see tangible returns from this research. Genome Canada is immensely proud of the exceptional work by the Canadian researchers and their international collaborators, which underscores the potential of genomics to make a positive impact on the lives of Canadians and others around the world."
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Agriculture & Food
| 2,020 |
November 25, 2020
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https://www.sciencedaily.com/releases/2020/11/201125114358.htm
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New wheat and barley genomes will help feed the world
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An international research collaboration, including scientists from the University of Adelaide's Waite Research Institute, has unlocked new genetic variation in wheat and barley -- a major boost for the global effort in breeding higher-yielding wheat and barley varieties.
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Researchers from the 10+ Wheat Genomes Project, led by Professor Curtis Pozniak (University of Saskatchewan, Canada), and the International Barley Pan Genome Sequencing Consortium, led by Professor Nils Stein (Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Germany), have sequenced a suite of genomes of both cereals, published today in the journal "Wheat and barley are staple food crops around the world but their production needs to increase dramatically to meet future food demands," says the University of Adelaide's Associate Professor Ken Chalmers who, together with his School of Agriculture, Food & Wine colleague Professor Emeritus Peter Langridge, led the Adelaide research. "It is estimated that wheat production alone must increase by more than 50% over current levels by 2050 to feed the growing global population." Professor Chengdao Li at Murdoch University also played a key role in the Australian component of the barley sequencing.Today's published research brings scientists closer to unlocking the entire gene set -- or pan genomes -- of wheat and barley. Through understanding the full extent of genetic variation in these cereals, researchers and plant breeders will have the necessary tools to realise the required increased global production."Advances in genomics have accelerated breeding and the improvement of yield and quality in crops including rice and maize, but similar efforts in wheat and barley have been more challenging," says Professor Langridge. "This is largely due to the size and complexity of their genomes, our limited knowledge of the key genes controlling yield, and the lack of genome assembly data for multiple lines of interest to breeders."Modern wheat and barley cultivars carry a wide range of gene variants and diverse genomic structures that are associated with important traits, such as increased yield, drought tolerance and disease resistance."This variation cannot be captured with a single genome sequence. Only by sequencing multiple and diverse genomes can we begin to understand the full extent of genetic variation, the pan genome." The two international projects have sequenced multiple wheat and barley varieties from around the world. The Adelaide component was supported by the Grains Research and Development Corporation (GRDC)."The information generated through these collaborative projects has revealed the dynamics of the genome structure and previously hidden genetic variation of these important crops, and shown how breeders have achieved major improvements in productivity. This work will support the delivery of the next generations of modern varieties," Associate Professor Chalmers says.The inclusion of two Australian varieties of wheat, AGT-Mace (PBR) and Longreach-Lancer (PBR) reflecting both the southern and northern growing areas, means that potential genetic variation for adaptation to our different production environments can be identified.The University of Adelaide also sequenced three barley varieties with desirable traits such as high-yield and potential for tolerance to heat, frost, salinity and drought, and novel disease resistance."These genome assemblies will drive functional gene discovery and equip researchers and breeders with the tools required to bring the next generation of modern wheat and barley cultivars that will help meet future food demands," says Associate Professor Ken Chalmers.
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Agriculture & Food
| 2,020 |
November 25, 2020
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https://www.sciencedaily.com/releases/2020/11/201125114353.htm
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New modified wheat could help tackle global food shortage
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Researchers at the University of York have created a new modified wheat variety that increases grain production by up to 12%.
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Wheat is one of the most important food crops in the world, providing 20% of human calories; with ever increasing global food demand, increasing crop yield is critically important.Wheat breeders work hard to increase yield to meet global demand, but since the 'green revolution' of the 1960s, the rate of yield increase has been slowing and is currently less than 1% per year.Most improvements have been made by breeding varieties that produce higher numbers of grain, but it should also be possible to increase yield by producing plants with bigger grains. When this has been achieved, however, it is accompanied by a decrease in grain numbers.Researchers at the University of York have now resolved this issue by directly modifying the growth of the young developing grain by increasing the amount of a protein that controls growth rates in plants.This resulted in plants that produced grain that are up to 12% bigger than in the conventional variety. In field experiments conducted by their collaborators in Chile, they found that there was no decrease in grain number, resulting in an increase in yield.Professor Simon McQueen-Mason, from the University of York's Centre for Novel Agricultural Products (CNAP) at the Department of Biology, said: "Experts predict that we need to increase global food production by 50% by 2030 in order to meet demand from population growth. The negative impacts of climate change on crop yields are making this even more challenging. While researchers are working hard to meet this challenge, there remains a lot to do.""Attempts to increase the yield of wheat have been thwarted by the apparent trade-off between grain size and grain number. We decided to side-step this complex control system by giving a boost to the natural growth system that controls the size of plant tissues."We did this by increasing the levels of a protein called expansin, which is a major determinant of growth in plants. We targeted this modification so that it was confined to developing wheat grain, and are delighted by the results."Research partners at the Universidad Austral de Chile conducted field experiments that demonstrated the effectiveness of the plants under agricultural conditions.The team are now looking at ways to make this research accessible to farmers and the wider industry to help inform their decisions on crop production.
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Agriculture & Food
| 2,020 |
November 25, 2020
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https://www.sciencedaily.com/releases/2020/11/201125100300.htm
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New discovery by SMART allows early detection of shade avoidance syndrome in plants
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Researchers from the Disruptive & Sustainable Technologies for Agricultural Precision (DiSTAP) Interdisciplinary Research Group (IRG) of Singapore-MIT Alliance for Research and Technology (SMART), MIT's research enterprise in Singapore and Temasek Life Sciences Laboratory (TLL) have discovered a way to use Raman spectroscopy for early detection of shade avoidance syndrome (SAS) in plants. The discovery can help farmers with timely intervention against SAS, leading to better plant health and crop yield.
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SAS is an adaptive response and an irreversible phenomenon, where plants reach for more light to overcome shaded conditions. It is commonly seen in plants experiencing vegetative shade which is detrimental to plant health, as it leads to a number of issues including hindrance of leaf development, early flowering and weakening of the plant's structure and immune system.Thus, early detection of SAS is key for sustainable agriculture and improved crop yield. However, existing methods for detection of SAS in plants are restricted to observing structural changes, making it difficult to detect SAS early.In a paper titled "Rapid metabolite response in leaf blade and petiole as a marker for shade avoidance syndrome" published in the journal "Our experiments with Raman spectroscopy detected a decrease in the carotenoid contents of plants that have SAS," said Dr Gajendra Pratap Singh, co-first author of the paper and Scientific Director and Principal Investigator at DiSTAP. "While plants with longer exposure to shade developed more severe SAS, these morphological changes were only seen after one to three days. However, changes in the carotenoid peak intensities were detected much earlier, from just four hours of shade treatment."Using Raman spectroscopy, the scientists are able to non-destructively measure carotenoid content in the plant leaves, and have discovered its correlation to the severity of SAS and as a peak biomarker for early diagnosis. This cuts down the time taken to detect SAS from days to a matter of hours. The method can also be used to detect SAS in plants due to high-density planting and can be particularly useful to improve urban farming practices."We conducted our experiments on a number of edible plants, including frequently consumed Asian vegetables like Kai Lan and Choy Sum," said Mr Benny Jian Rong Sng, the paper's co-first author and PhD student from Dr In-Cheol Jang's group at TLL and Department of Biological Sciences, National University of Singapore. "Our results showed that Raman spectroscopy can be used to detect SAS, induced by shade as well as high-density planting. Regardless of the food crop, this technology can be applied to improve agriculture and to meet the nutritional demands of today's growing populations."Dr In-Cheol Jang, Principal Investigator at TLL and DiSTAP, who led the project said the novel discovery can go a long way in assisting farmers to improve urban farming practices. "We look forward to helping urban farmers achieve higher crop yields by detecting SAS within shorter time periods. By adopting scalable, precision agri-technologies like Raman spectroscopy-enabled sensors, we can better position cities like Singapore to grow more produce with less resources, while achieving desirable nutritional profiles for global food security."
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Agriculture & Food
| 2,020 |
November 24, 2020
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https://www.sciencedaily.com/releases/2020/11/201124190536.htm
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Microbes help unlock phosphorus for plant growth
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Phosphorus is a necessary nutrient for plants to grow. But when it's applied to plants as part of a chemical fertilizer, phosphorus can react strongly with minerals in the soil, forming complexes with iron, aluminum and calcium. This locks up the phosphorus, preventing plants from being able to access this crucial nutrient.
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To overcome this, farmers often apply an excess of chemical fertilizers to agricultural crops, leading to phosphorus buildup in soils. The application of these fertilizers, which contain chemicals other than just phosphorus, also leads to harmful agricultural runoff that can pollute nearby aquatic ecosystems.Now a research team led by the University of Washington and Pacific Northwest National Laboratory has shown that microbes taken from trees growing beside pristine mountain-fed streams in Western Washington could make phosphorus trapped in soils more accessible to agricultural crops. The findings were published in October in the journal Endophytes, which are bacteria or fungi that live inside a plant for at least some of their lifecycle, can be thought of as "probiotics" for plants, said senior author Sharon Doty, a professor in the UW School of Environmental and Forest Sciences. Doty's lab has shown in previous studies that microbes can help plants survive and even thrive in nutrient-poor environments -- and help clean up pollutants.In this new study, Doty and collaborators found that endophytic microbes isolated from wild-growing plants helped unlock valuable phosphorus from the environment, breaking apart the chemical complexes that had rendered the phosphorus unavailable to plants."We're harnessing a natural plant-microbe partnership," Doty said. "This can be a tool to advance agriculture because it's providing this essential nutrient without damaging the environment."Doty's research scientist, Andrew Sher, and UW undergraduate researcher Jackson Hall demonstrated in lab experiments that the microbes could dissolve the phosphate complexes. Poplar plants inoculated with the bacteria in Doty's lab were sent to collaborator Tamas Varga, a materials scientist at the Environmental Molecular Sciences Laboratory at Pacific Northwest National Laboratory in Richland, Washington. There researchers used advanced imaging technologies at their lab and at other U.S. Department of Energy national laboratories to provide clear evidence that the phosphorus made available by the microbes did make it up into the plant's roots.The imaging also revealed that the phosphorus gets bound up in mineral complexes within the plant. Endophytes, living inside plants, are uniquely positioned to re-dissolve those complexes, potentially maintaining the supply of this essential nutrient.While previous work in Doty's lab demonstrated that endophytes can supply nitrogen, obtained from the air, to plants, such direct evidence of plants using phosphorus dissolved by endophytes was previously unavailable.The bacteria used in these experiments came from wild poplar trees growing along the Snoqualmie River in Western Washington. In this natural environment, poplars are able to thrive on rocky riverbanks, despite low availability of nutrients like phosphorus in their natural habitat. Microbes help these trees capture and use the nutrients they need for growth.These findings can be applied to agriculture crops, which often sit, unused, on an abundance of "legacy" phosphorus that has accumulated in the soil, unused, from years of fertilizer applications. Microbes could be applied in the soil among young crop plants, or as a coating on seeds, helping to unlock phosphorus held captive and making it available for use by plants to grow. Reducing the use of fertilizers and employing endophytes -- such as those studied by Doty and Varga -- opens the door for more sustainable food production."This is something that can easily be scaled up and used in agriculture," Doty said.UW has already licensed the endophyte strains used in this study to Intrinsyx Bio, a California-based company working to commercialize a collection of endophyte microbes. The direct evidence provided by Doty and Varga's research of endophyte-promoted phosphorus uptake is "game-changing for our research on crops," said John Freeman, chief science officer of Intrinsyx Bio.
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Agriculture & Food
| 2,020 |
November 24, 2020
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https://www.sciencedaily.com/releases/2020/11/201124152822.htm
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Can we harness a plant's ability to synthesize medicinal compounds?
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Anthraquinones are a class of naturally occurring compounds prized for their medicinal properties, as well as for other applications, including ecologically friendly dyes. Despite wide interest, the mechanism by which plants produce them has remained shrouded in mystery until now.
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New work from an international team of scientists including Carnegie's Sue Rhee reveals a gene responsible for anthraquinone synthesis in plants. Their findings could help scientists cultivate a plant-based mechanism for harvesting these useful compounds in bulk quantities."Despite its extensive practical applications, genomic studies of "Now that we've established the first step of the ladder, we can move quickly to elucidate the full suite of genes involved in the synthesis of anthraquinone," said lead author Kang.Once the process by which plants make these important compounds is fully known, this knowledge can be used to engineer a plant to produce high concentrations of anthraquinones that can be used medicinally."The same techniques that we use to help improve the yields of agricultural or biofuel crops can also be applied to developing sustainable production methods for plant-based medicines," Rhee concluded.This work was funded by the National Institute of Agricultural
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Agriculture & Food
| 2,020 |
November 24, 2020
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https://www.sciencedaily.com/releases/2020/11/201124152820.htm
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Pesticide deadly to bees now easily detected in honey
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A common insecticide that is a major hazard for honeybees is now effectively detected in honey thanks to a simple new method.
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Researchers at the University of Waterloo developed an environmentally friendly, fully automated technique that extracts pyrethroids from the honey. Pyrethroids are one of two main groups of pesticides that contribute to colony collapse disorder in bees, a phenomenon where worker honeybees disappear, leaving the queen and other members of the hive to die. Agricultural producers worldwide rely on honeybees to pollinate hundreds of billions of dollars worth of crops.Extracting the pyrethroids with the solid phase microextraction (SPME) method makes it easier to measure whether their levels in the honey are above those considered safe for human consumption. It can also help identify locations where farmers use the pesticide and in what amounts. The substance has traditionally been difficult to extract because of its chemical properties."Pyrethroids are poorly soluble in water and are actually suspended in honey," said Janusz Pawliszyn, a professor of chemistry at Waterloo. "We add a small amount of alcohol to dissolve them prior to extraction by the automated SPME system."Farmers spray the pesticides on crops. They are neurotoxins, which affect the way the brain and nerves work, causing paralysis and death in insects."It is our hope that this very simple method will help authorities determine where these pesticides are in use at unsafe levels to ultimately help protect the honeybee population," said Pawliszyn.The Canadian Food Inspection Agency tests for chemical residues in food in Canada. Maximum residue limits are regulated under the Pest Control Products Act. The research team found that of the honey products they tested that contained the pesticide, all were at allowable levels.
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Agriculture & Food
| 2,020 |
November 24, 2020
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https://www.sciencedaily.com/releases/2020/11/201124123646.htm
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Secrets of the 'lost crops' revealed where bison roam
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Blame it on the bison.
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If not for the wooly, boulder-sized beasts that once roamed North America in vast herds, ancient people might have looked past the little barley that grew under those thundering hooves. But the people soon came to rely on little barley and other small-seeded native plants as staple food.New research from Washington University in St. Louis helps flesh out the origin story for the so-called "lost crops." These plants may have fed as many Indigenous people as maize, but until the 1930s had been lost to history.As early as 6,000 years ago, people in the American Northeast and Midwest were using fire to maintain the prairies where bison thrived. When Europeans slaughtered the bison to near-extinction, the plants that relied on these animals to disperse their seeds began to diminish as well."Prairies have been ignored as possible sites for plant domestication, largely because the disturbed, biodiverse tallgrass prairies created by bison have only been recreated in the past three decades after a century of extinction," said Natalie Mueller, assistant professor of archaeology in Arts & Sciences.In a new publication in Mueller waded into the bison wallows after years of attempting to grow the lost crops from wild-collected seed in her own experimental gardens."One of the great unsolved mysteries about the origins of agriculture is why people chose to spend so much time and energy cultivating plants with tiny, unappetizing seeds in a world full of juicy fruits, savory nuts and plump roots," Mueller said.They may have gotten their ideas from following bison.Anthropologists have struggled to understand why ancient foragers chose to harvest plants that seemingly offer such a low return on labor."Before any mutualistic relationship could begin, people had to encounter stands of seed-bearing annual plants dense and homogeneous enough to spark the idea of harvesting seed for food," Mueller said.Recent reintroductions of bison to tallgrass prairies offer some clues.For the first time, scientists like Mueller are able to study the effects of grazing on prairie ecosystems. Turns out that munching bison create the kind of disturbance that opens up ideal habitats for annual forbs and grasses -- including the crop progenitors that Mueller studies.These plants include: goosefoot (At the Tallgrass Prairie Preserve, Mueller and her team members got some tips from local expert Mike Palmer."Mike let us know roughly where on the prairie to look," Mueller said. "His occurrence data were at the resolution of roughly a square mile, but that helps when you're on a 60-square-mile grassland."I thought it would be hard to find trails to follow before I went out there, but it's not," she said. "They are super easy to find and easy to follow, so much so that I can't imagine humans moving through a prairie any other way!"So-called 'little barley' is one of the small-seeded crop progenitors that Mueller has identified in stands around a bison pathsTelltale signs of grazing and trampling marked the "traces" that bison make through shoulder-high grasses. By following recently trodden paths through the prairie, the scientists were able to harvest seeds from continuous stands of little barley and maygrass during their June visit, and sumpweed in October."While much more limited in distribution, we also observed a species of Polygonum closely related to the crop progenitor and wild sunflowers in bison wallows and did not encounter either of these species in the ungrazed areas," Mueller said.It was easier to move through the prairie on the bison paths than to venture off them."The ungrazed prairie felt treacherous because of the risk of stepping into burrows or onto snakes," she said.With few landscape features for miles in any direction, the parts of the prairie that were not touched by bison could seem disorienting."These observations support a scenario in which ancient people would have moved through the prairie along traces, where they existed," Mueller said. "If they did so, they certainly would have encountered dense stands of the same plant species they eventually domesticated."Mueller encourages others to consider the role of bison as 'co-creators' -- along with Indigenous peoples -- of landscapes of disturbance that gave rise to greater diversity and more agricultural opportunities."Indigenous people in the Midcontinent created resilient and biodiverse landscapes rich in foods for people," she said. "They managed floodplain ecosystems rather than using levees and dams to convert them to monocultures. They used fire and multispecies interactions to create mosaic prairie-savanna-woodland landscapes that provided a variety of resources on a local scale."Mueller is now growing seeds that she harvested from plants at the Tallgrass Prairie Preserve and also seeds that she separated from bison dung from the preserve. In future years, Mueller plans to return to the preserve and also to visit other prairies in order to quantify the distribution and abundance of crop progenitors under different management regimes."These huge prairies would not have existed if the native Americans were not maintaining them," using fire and other means, Mueller said. But to what end? Archaeologists have not found caches of bones or other evidence to indicate that Indigenous people were eating lots of prairie animals. Perhaps the ecosystems created by bison and anthropogenic fire benefited the lost crops."We don't think of the plants they were eating as prairie plants," she said. "However, this research suggests that they actually are prairie plants -- but they only occur on prairies if there are bison."I think we're just beginning to understand what the botanical record was telling us," Mueller said. "People were getting a lot more food from the prairie than we thought."
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Agriculture & Food
| 2,020 |
November 24, 2020
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https://www.sciencedaily.com/releases/2020/11/201124101026.htm
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Researchers reveal switch used in plant defense against animal attack
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For decades, scientists have known that plants protect themselves from the devastation of hungry caterpillars and other plant-munching animals through sophisticated response systems, the product of millions of years of evolution.
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The biological mechanisms underlying this attack-counter defense paradigm have been vigorously pursued by plant biologists given that such details will help unlock a trove of new strategies for improved plant health. From countering crop pest damage to engineering more robust global food webs, such information is valuable for ensuring sustainable and reliable yields.Now, researchers at the University of California San Diego and their colleagues have identified the first key biological switch, or receptor, that sounds an alarm in plants specifically when herbivores attack. The discovery is described in the online publication of the Animals such as humans, cows and insects are heterotrophs that derive their energy either directly or indirectly through the consumption of autotrophs, such as photosynthetic plants. This basic foundation shapes biological interactions across planet Earth. More than 30 years ago plant biologists came to understand that plants can sense an attack from herbivorous animals in a way that is distinct from damage caused by hail storms or falling tree branches.Similar to how human immune defenses counter an attack from viruses, plants have been shown to respond to danger from plant-eating animals through an intricate immune system of receptors. Using a method of pinpointing genetic variants, called forward genetics, research led by Adam Steinbrenner, Alisa Huffaker and Eric Schmelz of UC San Diego's Division of Biological Sciences enabled discovery the inceptin receptor, termed INR, in bean plants. The receptor detects conserved plant protein fragments accidently released as digestive products during caterpillar munching, thereby enabling plant recognition of attack."INR represents the first documented mechanism of a plant cell surface receptor responsible for perceiving animals," said Schmelz, whose work was accomplished by deconstructing and leveraging the active evolutionary arms race between plants and herbivores. "Our work provides some of the earliest defined mechanistic insights into the question of how plants recognize different attacking herbivores and activate immunity to animals. It is a fundamental question in biology that has been pursued for 30 years."Beyond beans, the finding raises interest in using INR, and potentially other receptors that remain to be discovered, as a way to boost defenses in essential agricultural crops."A key lesson is that plant perception mechanisms for herbivores can be precisely defined and moved into crops to afford enhanced protection," said Schmelz. "We have shown one example but it's clear that hundreds if not thousands of opportunities exist to identify and stack key traits to enhance crop plant immunity to herbivores."The complete list of the study's authors: Adam Steinbrenner, Maria Muñoz-Amatriaín, Antonio Chaparro, Jessica Montserrat Aguilar Venegas, Sassoum Lo, Satohiro Okuda, Gaetan Glauser, Julien Dongiovanni, Da Shi, Marlo Hall, Daniel Crubaugh, Nicholas Holton, Cyril Zipfel, Ruben Abagyan, Ted Turlings, Timothy Close, Alisa Huffaker and Eric Schmelz.
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Agriculture & Food
| 2,020 |
November 23, 2020
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https://www.sciencedaily.com/releases/2020/11/201123173442.htm
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Genetics behind deadly oat blight
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A multi-institution team co-led by a Cornell University researcher has identified the genetic mechanisms that enable the production of a deadly toxin called Victorin -- the causal agent for Victoria blight of oats, a disease that wiped out oat crops in the U.S. in the 1940s.
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Victoria blight is caused by the fungus Cochliobolus victoriae, which produces the Victorin toxin, but until now no one has uncovered the genes and mechanisms involved."The oat varieties favored by farmers in the 1940s were resistant to Crown Rust disease, but scientists later discovered this was the very trait that made those oat varieties susceptible to Victoria blight because the Victorin toxin was targeting that specific plant protein," said co-senior author Gillian Turgeon, professor and chair of the Plant Pathology and Plant-Microbe Biology Section of the School of Integrative Plant Science, in Cornell's College of Agriculture and Life Sciences (CALS). "Unearthing the molecules involved in this fungus-plant interaction is fundamental to our understanding of how plants respond to attack by diverse microbes."Most fungal toxins are synthesized by large, multi-functional enzymes, and the small peptides created by these enzymes include both toxins and medicines, such as the antibiotic penicillin. But Turgeon and co-author Heng Chooi, a researcher at the University of Western Australia, discovered the Victorin toxin is actually synthesized directly in the ribosome, which is an organelle in cells that makes most proteins. These small molecules produced in ribosomes are known as ribosomally synthesized and post-translationally modified peptides, or RiPPs.This alternate mechanism for producing small peptides like Victorin -- coupled with the fact that fungal genomes likely contain many RiPP-associated genes -- could lead to the discovery of additional small molecules, including both new toxins and beneficial compounds.Further, first author Simon Kessler, a doctoral student at the University of Western Australia, confirmed the enzymatic function of several Victorin genes, including a novel enzyme that converts the Victorin peptide to its active form. Surprisingly, the research team found that the Victorin genes encoding these enzymes are scattered across repetitive regions in the pathogen genome -- a stark contrast to genes for most known small molecules which are typically found in compact clusters on the fungal chromosomes.The finding could help researchers better understand the evolutionary origins of molecules like the Victorin peptides, what determines the virulence of emerging crop diseases and how to better prevent them in the future.Turgeon notes that Victorin peptides have also been shown to interact with targets in plant cells called thioredoxins, which are also found in humans, and have potential as a site for cancer therapies."The discovery that these genes are not found in closely related fungi gives us insight into how virulence factors are acquired and transmitted," Turgeon said. "Our findings from this study vastly expand the potential for small molecule discovery in fungal organisms, which will increase our repertoire of knowledge about both their beneficial and harmful activities."
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Agriculture & Food
| 2,020 |
November 23, 2020
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https://www.sciencedaily.com/releases/2020/11/201123161009.htm
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Making sense of a universe of corn genetics
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Seed banks across the globe store and preserve the genetic diversity of millions of varieties of crops. This massive collection of genetic material ensures crop breeders access to a wealth of genetics with which to breed crops that yield better or resist stress and disease.
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But, with a world of corn genetics at their disposal, how do plant breeders know which varieties are worth studying and which ones aren't? For most of history, that required growing the varieties and studying their performance in the real world. But innovative data analytics and genomics could help plant breeders predict the performance of new varieties without having to go to the effort of growing them.Jianming Yu, a professor of agronomy at Iowa State University and the Pioneer Distinguished Chair in Maize Breeding, has devoted much of his research to "turbo charging" the seemingly endless amount of genetic stocks contained in the world's seed banks. Yu and his colleagues have published an article in the Plant breeders searching for varieties to test might feel lost in a sea of genomic material. Yu said applying advanced data analytics to all those genomes can help breeders narrow down the number of varieties they're interested in much faster and more efficiently."We're always searching for the best genetic combinations, and we search the various combinations to see what varieties we want to test," said Xiaoqing Yu (no relation), a former postdoctoral research associate in Yu's lab and the first author of the study. "Having these predictions can guide our searching process."The study focused on predicting eight corn traits based on the shoot apical meristem (SAM), a microscopic stem cell niche that generates all the above-ground organs of the plant. The researchers used their analytical approach to predict traits in 2,687 diverse maize inbred varieties based on a model they developed from studying 369 inbred varieties that had been grown and had their shoot apical meristems pictured and measured under the microscope.The researchers then validated their predictions with data obtained from 488 inbreds to determine their prediction accuracy ranged from 37% to 57% across the eight traits they studied."We wanted to connect the research in foundational biological mechanisms of cell growth and differentiation with agronomic improvement of corn," said Mike Scanlon, a professor of developmental biology at Cornell University and the lead investigator of the multi-institutional team behind the study. "SAM morphometric measurements in corn seedlings allow a quick completion of the study cycle. It not only enables that connection, but also extends the practice of genomic prediction into the microphenotypic space."Jianming Yu said plant breeders can bump up the accuracy of those genomic predictions by increasing the number of plants per inbred for measurement and findings-improved prediction algorithms. More importantly, plant breeders can finetune their selection process for which inbreds to study closely by leveraging the "U values," a statistical concept that accounts for the reliability of estimates. Yu said the study shows that implementing a selection process that accounts for prediction and statistical reliability can help plant breeders zero in on desirable crop genetics faster.For instance, analytical models might predict a particular inbred to have modest potential for a given trait, but the U value, or the upper bound for reliability, might indicate a high degree of unreliability in those predictions. So plant breeders might elect to test inbreds that don't do as well in the predictive model simply because of their genetic uniqueness, being less related to those used in building the prediction models."We found that there can be a balance between selecting for optimizing short-term gain and mining diversity," Yu said. "It's a tricky balance for plant breeders. Those considerations sometimes go in different directions. Genetic improvement can be viewed as space exploration, either of the vast amount of existing genetic materials in seed banks or of the innumerable breeding progenies constantly being generated. We want to develop better tools to guide those decisions in the process."
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Agriculture & Food
| 2,020 |
November 20, 2020
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https://www.sciencedaily.com/releases/2020/11/201120095858.htm
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Glyphosate may affect human gut microbiota
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Glyphosate is the most commonly used broad-spectrum herbicide. Researchers from the University of Turku in Finland have developed a new bioinformatics tool to predict if a microbe, e.g. a human gut bacterium, is sensitive to glyphosate.
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"Glyphosate targets an enzyme called EPSPS in the shikimate pathway. This enzyme is crucial to synthesizing three essential amino acids. Based on the structure of the EPSPS enzyme, we are able to classify 80-90% of microbial species into sensitive or resistant to glyphosate," says Docent Pere Puigbò, developer of the new bioinformatics tool.Based on the analyses using the new bioinformatics tool, 54% of the human core gut bacterial species are potentially sensitive to glyphosate."This groundbreaking study provides tools for further studies to determine the actual impact of glyphosate on human and animal gut microbiota and thus to their health," explains Docent Marjo Helander.Glyphosate is thought to be safe to use because shikimate pathway is found only in plants, fungi and bacteria. However, glyphosate may have a strong impact on bacterial species in the human microbiome, and several recent studies have shown that perturbations in the human gut microbiome are connected to many diseases. Therefore, the widespread use of glyphosate may have a strong effect on gut microbiomes as well as on human health.The dominance of this herbicide in the pesticide market is mainly attributed to the use of transgenic crops, such as soy, corn and canola, which are often grown as glyphosate-resistant varieties outside Europe. In Europe, glyphosate is commonly used to desiccate cereal, bean and seed crops before harvest. It is also used to eradicate weeds prior to sowing in no-till cropping systems.The risk to come across glyphosate residue in food that has been grown in Finland is small, because desiccation of the cereal fields by glyphosate is not allowed in Finland.A rich and diverse microbial community is living in soil, on plant surfaces, and in animal guts. It is possible that even low glyphosate residue may indirectly affect pest and pathogen occurrence in these communities."In addition to bioinformatics, we need experimental research to study the effects of glyphosate on microbial communities in variable environments," Helander adds.
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Agriculture & Food
| 2,020 |
November 19, 2020
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https://www.sciencedaily.com/releases/2020/11/201119141714.htm
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Researchers recommend more transparency for gene-edited crops
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Researchers at North Carolina State University call for a coalition of biotech industry, government and non-government organizations, trade organizations, and academic experts to work together to provide basic information about gene-edited crops to lift the veil on how plants or plant products are modified and provide greater transparency on the presence and use of gene editing in food supplies.
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At issue is a May 2020 U.S. Dept. of Agriculture rule called SECURE (sustainable, ecological, consistent, uniform, responsible, efficient) that governs genetically engineered organisms. The rule is expected to exempt most genetically modified plants to pre-market field testing and data-based risk assessment. In fact, the USDA estimates that 99% of biotech crops would receive this exemption.NC State researchers Jennifer Kuzma and Khara Grieger, in a policy forum paper published in the journal "It's pretty clear that consumers want to know which products are genetically modified and which are not, and we suspect that these desires will not be different for gene-edited crops," said Kuzma, the Goodnight-NC GSK Foundation Distinguished Professor in the Social Sciences and co-director of the Genetic Engineering and Society Center at NC State. "Crop developers, including companies, have signaled that they want to do better with gene editing to improve public trust. We present a model for them to improve transparency and obtain certification based on providing information about their gene-edited and other GM crops in a public repository."To provide more transparency, the NC State researchers recommend the creation of CLEAR-GOV, or a "Community-Led and Responsive Governance" coalition, that would provide access to basic information on biotech crops in accessible language. That would include the species and variety of plant, type of trait modified, improved quality provided by the trait modification, general areas where the crop is grown, and downstream uses of the crop. CLEAR-GOV would be operated through a non-profit organization staffed by experts from a variety of academic fields."If leadership at a non-profit, independent research organization decided that this is something that they are passionate about, they could see a market value in housing this coalition and hosting this depository," said Grieger, a paper co-author and assistant professor and extension specialist in NC State's Department of Applied Ecology.Kuzma adds that CLEAR-GOV would fill an important gap for consumers and other stakeholder groups who want to know more about gene-edited products in the marketplace."Because many gene-edited crops would be exempt under SECURE and new GM food-labeling rules may also not apply to them, there needs to be some information repository for companies that want to do the right thing and be more transparent," Kuzma said. "Our recommendations would provide a mechanism for that."
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Agriculture & Food
| 2,020 |
November 18, 2020
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https://www.sciencedaily.com/releases/2020/11/201118080800.htm
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Tackling food allergies at the source
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Food allergies are a big problem. About 7% of children and 2% of adults in the U.S. suffer from some kind of food allergy. These allergies cost a whopping $25 billion in health care each year. Then there's the time lost at school or work. And there's the risk of serious complications, even death.
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It's critical to find ways to reduce the suffering caused by food allergies. Food processing companies already spend a lot of effort to label products so people can avoid items they're allergic to. But what if we could do better? What if we could enjoy the foods we like without worrying they might trigger a health crisis?That's the focus of Eliot Herman's work. Herman has spent his career studying why plants trigger allergic reactions and how to reduce the chance of them being triggered. Herman is a member of the Crop Science Society of America and recently presented his work at the virtual 2020 ASA-CSSA-SSSA Annual Meeting."Food allergies are an important societal issue. By altering food and by treating sensitive individuals, this can be mitigated, improving their lives and impacting the total medical expenditure in the U.S.," says Herman.Herman focuses particularly on soybeans. Soybean allergies especially affect children and infants. And because soybean products like oil and protein are used in countless food products, it's hard to avoid.Earlier in his career, Herman found the protein made by soybeans that is responsible for most soybean allergies. Now, he has dedicated his work to understanding why this protein is so aggravating and how we can reduce it in the crop.To do so, he's turning to animal models. Pigs sometimes have a soybean allergy very similar to that of humans. Herman worked with a research team that bred pigs that are extra sensitive to soybeans. Testing new crops on allergic children wouldn't be possible. But these pigs can be used to see how well plant breeders have done at removing allergenic proteins from soybean seeds.That's a feat that Herman has done not once, but twice. Previously, Herman partnered with the company DuPont to produce a line of soybeans that couldn't make the most allergenic protein.They made this soybean line using genetic engineering. This new soybean was a genetically modified organism (GMO), and there was also demand for a non-GMO soybean without the allergenic protein.So Herman went back to the drawing board. He worked with his colleagues to find a line from the United States Department of Agriculture's (USDA) national soybean collection that naturally didn't make the allergenic protein. That means no genetic engineering would be necessary. They then crossed that line of soybeans with a more commonly grown soybeans to create a new, productive soybean with reduced allergic sensitivity."This new soybean is intended to be a low-allergen prototype to be tested as a conventional, non-GMO line to mitigate the allergic response for consumers," says Herman.The hypersensitive pigs can now be used to test if these low-allergen soybeans are safe enough for allergic individuals. That wouldn't only be good for allergic people who want to safely eat more items from the grocery store. It would also be good news for animals.Since pigs are often fed soybeans, a low-allergen soybean could reduce their own allergic response. Dogs also have a high prevalence of allergic reactions to soybean, which is used in some dog foods. So reducing the crop's allergenicity would be good for man's best friend, too."Food has been recognized as medicine since ancient times. By reducing soybean's allergens, we hope to produce positive a medical outcome for humans and animals," says Herman.Eliot Herman is a professor of plant sciences and Bio5 Institute at the University of Arizona. This work was funded by United Soybean Board and the United States Department of Agriculture National Institute of Food and Agriculture.
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Agriculture & Food
| 2,020 |
November 17, 2020
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https://www.sciencedaily.com/releases/2020/11/201117133918.htm
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COVID-19 highlights risks of wildlife trade
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Many diseases, such as COVID-19, have made the jump from animals to people with serious consequences for the human host. An international research team, including researchers from the University of Göttingen, says that more epidemics resulting from animal hosts are inevitable unless urgent action is taken. In order to protect against future pandemics which might be even more serious, they call for governments to establish effective legislation addressing wildlife trade, protection of habitats and reduction of interaction between people, wildlife and livestock. Their review was published in
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An infectious disease caused by a pathogen -- such as a bacterium, virus or parasite -- that has jumped from an animal to a human is known as "zoonosis." In the last thirty years, the majority of human pathogens which have caused substantial damage to human health and economies have originated from wildlife or livestock. Such diseases include Ebola, AIDS and SARS. COVID-19 is among the latest of these zoonotic diseases and is currently a pandemic that has resulted in more than a million deaths worldwide.Two primary factors that facilitate such outbreaks are wildlife trade and fragmentation of natural habitat, both of which increase the frequency and potential for direct contact between humans and wildlife. Animals in wildlife markets are often housed in overcrowded and unsanitary conditions that create the perfect environment for pathogens to jump to humans. In addition, natural habitats are being cleared to meet the growing demands of an increasing human population, which puts livestock and people in closer contact with the wild hosts of potential zoonotic pathogens. Addressing these two factors could help prevent future zoonotic diseases.Recognising that COVID-19 may have emerged from wildlife markets, the governments of China, Vietnam and Korea have all introduced some form of regulation to control wildlife trade since the outbreak, each of which goes some way to supporting wildlife conservation. These actions provide examples for other countries to consider. The authors, however, advise against a sudden blanket ban on wildlife markets as this will have a disproportionately high negative impact on disadvantaged, migrant and rural populations that depend on such markets for their subsistence. Rather, a range of measures should be considered, including governments working with local communities to create and maintain alternative means of subsistence before appropriate bans -- specifically on live animals and non-food wildlife products -- are considered."The coronavirus pandemic has inevitably focussed our energy on managing the disease. But in order to prevent the next outbreak -- whatever form that might take -- there needs to be recognition that people's relationship with the natural world must change," explains co-author Dr Trishna Dutta, University of Göttingen, Department of Wildlife Sciences. She goes on to say, "There needs to be urgent action to regulate the trade of wildlife and reduce consumer demand for wildlife parts and products. This should be done in tandem with protecting native ecosystems and reducing the wildlife-livestock-human interface which originally sparked this pandemic."
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Agriculture & Food
| 2,020 |
November 13, 2020
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https://www.sciencedaily.com/releases/2020/11/201113141806.htm
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Gut check: Teff grain boosts stomach microbiome health
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The seeds of a teff plant -- which look similar to wheat -- are tiny in stature, but they pack a nutritional wallop.
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Relatively new to the U.S., teff has long been a superfood in East African -- specifically Ethiopia -- as a staple food crop rich in fiber.Cornell University food scientists, led by Elad Tako, associate professor of food science, now confirm this grain greatly helps the stomach and enhances the nutritional value of iron and zinc, according to a new modeling method. Their findings were reported Oct. 2 in the journal Teff was tested in Cornell food science labs to understand how its seed extracts would affect the gastrointestinal tract and other systems in living organisms, via the utilization of a unique in vivo approach."The grain teff is extremely valuable," said Tako, the paper's senior author. "For the first time, we were able to associate teff-seed extracts and teff consumption with positive effects on the intestinal microbiome composition and function, potentially explaining why the prevalence of dietary iron and zinc deficiencies in Ethiopia -- although still significant -- are lower in comparison to other neighboring African nations."Tako and his group conducted experiments while developing and using fertile eggs from the standard domesticated chicken (Gallus gallus). The embryonic phase of Gallus gallus lasts for 21 days, during which time the embryo is surrounded by amniotic fluid (egg whites), which is naturally and orally consumed by the embryo prior to hatch on day 21.In the experiment, the teff seed fiber extract was injected into the fertile Gallus gallus eggs' amniotic fluid, which consists mostly of water and short peptides, on day 17 of embryonic development. The amniotic fluid and the added nutritional solution are then consumed by the embryo by day 19 of embryonic incubation."By utilizing this unique in vivo model and research approach, we are able to test how a candidate compound -- in this case the teff grain extract -- or solution affects the gastrointestinal tract, but also other systems or other tissues," Tako said. "We were able to confirm positive effects on the intestinal microbiome and duodenal (small intestine) functionality and tissue morphology."Several important bacterial metabolic pathways were enriched by the teff extract, likely due to the grain's high relative fiber concentration, demonstrating an important bacterial-host interaction that contributes to improvements in the physiological status of iron and zinc, and the functionality of the intestinal digestive and absorptive surface."We're taking advantage of the embryonic phase, as a unique in vivo model to assess the potential nutritional benefits of plant origin bioactive compounds," said Tako, who is guest editor for an upcoming special issue of
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Agriculture & Food
| 2,020 |
November 13, 2020
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https://www.sciencedaily.com/releases/2020/11/201113124047.htm
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What does the fox say to a puma?
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In the high plains of the central Chilean Andes, an ecosystem consisting of only a few animal species is providing researchers with new insights into how predators coexist in the wild.
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"The puma and the culpeo fox are the only top predators on the landscape in the Chilean Andes," said Professor Marcella Kelly, of the College of Natural Resources and Environment. "And there isn't a wide range of prey species, in part because the guanacos [closely related to llamas] aren't typically found in these areas anymore due to over-hunting. With such a simplified ecosystem, we thought we could really nail down how two rival predators interact."Kelly worked with Christian Osorio, a doctoral student in the Department of Fish and Wildlife Conservation, and researchers from the Pontifical Catholic University of Chile to chart the locations of and potential interactions between pumas and foxes in central Chile. They focused on three axes of interaction: spatial (where the animals are on the landscape), temporal (the timing of specific activities on a given landscape), and dietary (what each species is eating).To understand the interplay between pumas and foxes, researchers deployed 50 camera stations across two sites in central Chile, one in the Rio Los Cipreses National Reserve and another on private land where cattle and horses are raised. They also collected scat samples at both locations to analyze the diets of pumas and foxes.The team's findings, published in the journal "It is likely that foxes have realized that when they try to hunt hares, they might run into trouble with pumas," Osorio explained. "If they are hunting smaller mammals, the pumas don't care, but if the foxes start targeting larger prey, the pumas will react."How predator species interact is a crucial question for ecologists trying to understand the dynamics that inform ecosystem balances. And while the puma has been designated a species of least concern, the animal's populations are declining and continue to be monitored by conservationists."Least concern does not mean no concern," Osorio noted. "We have laws in Chile that protect the species, but the data we have to make a conservation designation are very scattered. As we accumulate more consistent and reliable data, the puma may be reclassified as vulnerable or even endangered."The hares that comprise approximately 70 percent of the biomass in the puma's diet are a nonnative species, introduced to the area by European settlers. With guanacos absent from the landscape, the puma has had to adapt its diet to survive.With some land managers and conservationists campaigning for the removal of the introduced hare species as a way to restore the area's native ecosystem, Kelly and Osorio note that it is important to understand that pumas would be significantly impacted by a reduction in their primary food source.A further concern, which the two are currently researching, is the interplay between wildlife and humans. The national reserve increasingly sees visitors eager to witness big cats and foxes in their natural environment, while the sheep and cattle industries are increasingly using remote terrain for livestock cultivation."Pumas do occasionally kill livestock, which is a challenge we're looking into right now," said Kelly, an affiliate of Virginia Tech's Fralin Life Sciences Institute. "The government would like to preserve the puma, but there are competing challenges of what kind of threat they pose to livestock and what kind of threat cattle or sheep farming poses to them."Understanding how two predatory species can come to coexist has the potential to provide conservationists and ecologists with better ideas for how humans and wild animals can share a landscape.
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Agriculture & Food
| 2,020 |
November 11, 2020
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https://www.sciencedaily.com/releases/2020/11/201111095636.htm
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Rice has many fathers but only two mothers
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Researchers investigating the heritage of thousands of rice varieties have identified just two distinct maternal lineages, a discovery which could help address the issue of global food security.
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University of Queensland scientists studied more than 3000 rice genotypes and found diversity was inherited through two maternal genomes identified in all rice varieties.Lead researcher UQ's Professor Robert Henry said the finding was important in understanding how rice adapted to its environment."We think there were two separate domestications of virgin wild plants that diverged around a million years ago in the wild, and then in the last 7000 thousand years human domestication of rice has occurred," Professor Henry said.The two domesticated varieties interbred with the local wild rices throughout Asia."The wild rice has pollinated the domesticated rices planted nearby and the seed of the domesticated variety has then incorporated the genetics of the local wild varieties," he said."The maternal lineage is preserved via the seed, and we've identified that because rice farmers have and still continue to collect the seed from the field, the local varieties become very much like the local wild rices."Professor Henry said the finding had implications for domestication of rice and breeding for adaptation to climate change to address food security."It gives us clues as to how we might try to capture more of the diversity in the wild and bring it into the domesticated gene pool to improve rice crops," he said."It also points to the need to understand the significance of the maternal genotype in terms of performance of rice because we did not previously understand there are two very distinct maternal functional types."Rice is the staple food of more than half of the world's population and is the third-largest worldwide agricultural crop, with more than 630 million tonnes produced annually."Now we've got an ongoing collaboration with mathematicians to try and find a way of analysing the rice data in more detail, we want to look at relationships between lots of different subgroups," Professor Henry said."This would include examining how the Basmatis and the Japonicas really relate and the various types of Indica rices."
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Agriculture & Food
| 2,020 |
November 10, 2020
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https://www.sciencedaily.com/releases/2020/11/201110133217.htm
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Crop diversification can improve environmental outcomes without sacrificing yields
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A new study shows diversifying agricultural systems beyond a narrow selection of crops leads to a range of ecosystem improvements while also maintaining or improving yields. But a professor of agronomy at Iowa State University who co-authored the study said some marketing and agricultural policy considerations will have to change for farmers to adopt diversification practices more widely.
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The study, published last week in the academic journal "The overall conclusion is there's a lot to be gained from diversifying cropping practices," said Matt Liebman, a professor of agronomy at Iowa State and co-author. "Across many different countries in many different climates and soils, with many different crops, the general pattern is that with diversification, you maintain or increase crop yields while gaining environmental benefits."Agriculture in the Midwest is dominated by just a few crops, mainly corn and soybeans. But the study looked at a range of farming practices aimed at introducing more diversity to cropland. Those diversification practices include crop rotations, planting prairie strips within and along fields, establishing wildlife habitat near fields, reducing tillage and enriching soil with organic matter. Such measures improve water quality, pollination, pest regulation by natural enemies, nutrient turnover and reduced negative climate impacts by sequestering carbon in the soil."My colleagues and I wanted to test if diversification is beneficial for both agricultural production and ecosystem services. The current trend is that we simplify major cropping systems worldwide. We grow monocultures on enlarged fields in homogenized landscapes. The results of our study indicate that diversification can reverse the negative impacts that we observe in simplified forms of cropping on the environment and on production itself," said lead author Giovanni Tamburini at the Swedish University of Agricultural Sciences and University of Bari.Liebman said barriers related to government ag policy, market considerations and the dissemination of data discourage farmers from adopting many of the diversification practices examined in the study. But showing that such practices do not depress yields, and in some cases increase them, might encourage farmers to consider the practices.Many current policies and market conditions incentivize farmers to focus on a few highly productive and profitable crops. In Iowa, that means corn and soybeans are grown on the majority of cropland. But Liebman said rethinking those considerations, as well as working with farmers to transfer knowledge that allows them to gain confidence with diversification, could lead to wider use of the practices.The meta-analysis approach allowed the research team to combine data from thousands of other studies that tested how crop diversification affects yields. The researchers used innovative data analytics to find patterns in those results, Liebman said. The approach allowed the research team to gain a new level of insight that isn't possible with individual experiments."What our study suggests is that if we want improved water quality and enhanced wildlife habitat and if we want to continue to work on the soil erosion problem, diversification offers a lot of options to us," Liebman said.
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Agriculture & Food
| 2,020 |
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