PIN1 auxin efflux carriers localization studies in Zea mays

摘要

Polar auxin transport is a unique process mediating a wide variety of plant developmental processes. Specific trans-membrane carriers (AUX1/LAX, PGP and PIN protein families) mediate the auxin transport between cells, creating auxin gradients that, inturn, control gene expression. The direction of auxin flow within tissues is mainly determined by the asymmetric subcellular localization of PIN auxin efflux carriers in each transporting cell. For this reason, the mechanisms controlling the subcellulardynamics of auxin transport machinery, in response to developmental and environmental stimuli, are instrumental in the regulation of whole plant development, from embryogenesis to organogenesis, vascular tissue differentiation and tropisms. Here we report the first evidence of differential regulation mechanisms controlling the subcellular dynamics of PINl efflux carriers in maize. The coordination of cell differentiation is an essential prerequisite for the development of multicellular organisms, plants and animals in primis. In addition, plants require a greater developmental plasticity to provide for their sessile lifestyle, shaping their body and optimizing their metabolism for specific environmental demands. This flexibility is based on the stablepresence of stem cell populations (meristems) and involves de novo organogenesis, and directional growth responses to external stimuli.