Auxin and cellular elongation

SILVIAMELINA VELASQUEZ, ELKE BARBEZ, JÜRGEN KLEINE-VEHN & JOSÉ M. ESTEVEZ

PLANT PHYSIOLOGY.

AMER SOC PLANT BIOLOGISTS

Lugar: Rockville; Año: 2016

0032-0889

Auxinis a crucial growth regulator in plants. However, a comprehensive understandingof how auxin induces cell expansion is perplexing, because auxin acts in aconcentration- and cell-type dependent manner. Consequently, itis desirable to focus on certain cell types to exemplify the underlying growthmechanisms. On the other hand, plant tissues displaysupracellular growth (beyond the level of single cells) and, hence, other celltypes might compromise the growth of a certain tissue. Tip-growing cells do notdisplay neighbour-induced growth constrains and, therefore, are a valuablesource of information for growth controlling mechanisms. Here we focus on auxin-inducedcellular elongation in root hairs, exposing a mechanistic view of plant growthregulation. We highlight a complex interplay between auxin metabolism andtransport, steering root hair development in response to internal and externaltriggers. Auxin signalling modules and downstream cascades of transcriptionfactors define a developmental program, which appears rate-limiting forcellular growth. With this knowledge in mind, the root hair cell is a verysuitable model system to dissect cellular effectors required for cellularexpansion.