New molecular components that regulate the transcriptional hub in root hairs: coupling environmental signals with endogenous hormones to coordinate growth

Abstract

Root hairs have become an important model system for studying plant growth, and in particular how plants modulate their growth in response to cell-intrinsic and environmental stimuli. In this review, we discuss recent advances in our understanding of the molecular mechanisms underlying the growth of Arabidopsis root hairs in the interface between responses to environmental cues (e.g. nutrients such as nitrates and phosphate, and microorganisms) and hormonal stimuli (e.g. auxin). Growth of root hairs is under the control of several transcription factors that are also under strong regulation at different levels. We highlight recent new discoveries along these transcriptional pathways that might have the potential to increase our capacity to enhance nutrient uptake by the roots in the context of abiotic stresses. We use the text-mining capacities of the PlantConnectome database to generate an up-to-date view of root hairs growth within these complex biological contexts.

Keywords: ABA; Auxin Response Factor (ARF); PlantConnecome; RHD6-Like 4 (RSL4); Root Hair Defective 6 (RHD6); Root Hairless-Like 3 (LRL3); cytokinin; ethylene; nitrates; nutrition; phosphate; root hairs; transcription factor.