摘要
Multicellular organisms maintain their growth and development in a dynamic and coordinated fashion.Cell polarity plays a key role in regulating cellular differentiation and proliferation during growth and development.In plants,several developmental processes such as embryogenesis,leaf venation,stomatal patterning,and phyllotaxy depend on establishment of cellular polarity.One of the best understood plant polarity proteins is the family of PINFORMED(PIN)auxin efflux carriers.PIN-mediated auxin transport has been central to a canalization hypothesis whereby auxin transport actively promotes vasculature formation and influences leaf venation patterns,but its exclusive role in the latter has been recently challenged(Verna et al.,2019).In the canalization hypothesis,positive feedback of auxin transport occurs in cells with increased auxin flux and leads to the establishment of auxin sinks within an organ(Sachs,1991).
