The regulation and plasticity of root hair patterning and morphogenesis

Abstract

Root hairs are highly specialized cells found in the epidermis of plant roots that play a key role in providing the plant with water and mineral nutrients. Root hairs have been used as a model system for understanding both cell fate determination and the morphogenetic plasticity of cell differentiation. Indeed, many studies have shown that the fate of root epidermal cells, which differentiate into either root hair or non-hair cells, is determined by a complex interplay of intrinsic and extrinsic cues that results in a predictable but highly plastic pattern of epidermal cells that can vary in shape, size and function. Here, we review these studies and discuss recent evidence suggesting that environmental information can be integrated at multiple points in the root hair morphogenetic pathway and affects multifaceted processes at the chromatin, transcriptional and post-transcriptional levels.

Diversification of Root Hair Development Genes in Vascular Plants

“…Arabidopsis is unique among the plants analyzed in this study because its root hair pattern is position dependent, with root hair cells limited to longitudinal cell files in particular locations (type 3), whereas the other six species produce root hair and nonhair epidermal cells in a random distribution (type 1; Fig. 4B; Clowes, 2000;Pemberton et al, 2001;Balcerowicz et al, 2015;Salazar-Henao et al, 2016). We generated maximum likelihood trees and analyzed root gene expression for relatives of 12 Arabidopsis patterning genes (present in seven gene families; Supplemental Table S7; Supplemental Fig.…”

“…In particular, molecular genetic analyses have led to the identification of numerous root hair genes, which provide insight into the mechanisms of Arabidopsis root hair development (Bruex et al, 2012;Gu and Nielsen, 2013;Grierson et al, 2014;Balcerowicz et al, 2015;Salazar-Henao et al, 2016). Root hair-bearing cells in Arabidopsis are specified by a set of early-acting patterning genes that generate a cell position-dependent distribution of root hair cells and nonhair cells via a complex transcriptional regulatory network (Grierson et al, 2014;Salazar-Henao et al, 2016).…”

“…In particular, molecular genetic analyses have led to the identification of numerous root hair genes, which provide insight into the mechanisms of Arabidopsis root hair development (Bruex et al, 2012;Gu and Nielsen, 2013;Grierson et al, 2014;Balcerowicz et al, 2015;Salazar-Henao et al, 2016). Root hair-bearing cells in Arabidopsis are specified by a set of early-acting patterning genes that generate a cell position-dependent distribution of root hair cells and nonhair cells via a complex transcriptional regulatory network (Grierson et al, 2014;Salazar-Henao et al, 2016). Once specified, the presumptive root hair cells initiate the outgrowth of the root hair through the action of the ROOT HAIR DEFECTIVE6 (RHD6) gene, which encodes a basic helix-loop-helix (bHLH) transcription factor that induces an extensive root hair gene expression program through the activation of additional regulatory genes Menand et al, 2007;Yi et al, 2010;Bruex et al, 2012).…”

“…This suite of downstream root hair morphogenesis genes generates the unidirectional expansion (tip growth) of the root hair (Datta et al, 2011;Balcerowicz et al, 2015). These genes encode proteins involved in secretory activities, cell wall synthesis, ion transport, reactive oxygen species regulation, and many other processes (Balcerowicz et al, 2015;Salazar-Henao et al, 2016). The expression profiles of the patterning genes, initiation genes, and morphogenesis genes differ along the longitudinal length of the root tip, which reflects their temporal importance in root hair development (Datta et al, 2011;Grierson et al, 2014).…”

Volatile organic compounds stimulate plant growing and seed germination of Lactuca sativa

“…In the last decade, Ryu et al (2003) so many studies have focused on these parameters (Salazar-henao et al, 2016). Until now, mycorrhiza associations have been studied intensively for decades by its role to tolerate biotic and abiotic stress, plant productivity, nutrients acquisition and plant productivity ( Van der Heijden et al, 2015).…”