Mechanistic Framework for Establishment, Maintenance, and Alteration of Cell Polarity in Plants

Figure 1

Polar-localized auxin efflux carrier PIN proteins direct auxin flow. Note that apical PINs guide upward auxin flow and the basal PINs guide downward auxin flow. Generation of directional auxin flux creates auxin accumulation zones that are required for proper progression of embryogenesis and for postembryonic organ functioning such as the root growth.