string: …Northwest A&F University, Yangling, Shaanxi, China
  (Bonilla et al. 2004), cell division (Hepler 1994), root tip growth (Bibikova et al. 1997), fertilization in flowering plants (Digonnet et al. 1997), pollen germination, pollen tube growth (Li et al. 1999), and plant senescence (Ferguson 1984).