Auxin gradient is crucial for the maintenance of root distal stem cell identity in Arabidopsis

Abstract

The plant hormone auxin plays a critical role in the maintenance of root stem cell niches in Arabidopsis. We have recently reported that WUSCHEL-RELAT ED HOM EOBOX 5 (WOX5) transcription factor modulates free auxin production in the quiescent center (QC) of the root and its expression is inhibited in a feedback-dependent manner by canonical auxin signaling that involves indole-3-acetic acid 17 (IAA 17) auxin response repressor. WOX5-IAA 17 feedback circuit assures the maintenance of auxin response maximum in the root tip and thereby contributes to the maintenance of distal stem cell (DSC) populations. Here, we provide evidence to show that an optimal auxin maximum in QC guided auxin signaling gradient in root tips is crucial for maintaining root DSC identity. © 2013 Landes Bioscience.