Transcriptional regulation of PIN genes by FOUR LIPS and MYB88 during Arabidopsis root gravitropism

Abstract

PIN proteins are auxin export carriers that direct intercellular auxin flow and in turn regulate many aspects of plant growth and development including responses to environmental changes. The Arabidopsis R2R3-MYB transcription factor FOUR LIPS (FLP) and its paralogue MYB88 regulate terminal divisions during stomatal development, as well as female reproductive development and stress responses. Here we show that FLP and MYB88 act redundantly but differentially in regulating the transcription of PIN3 and PIN7 in gravity-sensing cells of primary and lateral roots. On the one hand, FLP is involved in responses to gravity stimulation in primary roots, whereas on the other, FLP and MYB88 function complementarily in establishing the gravitropic set-point angles of lateral roots. Our results support a model in which FLP and MYB88 expression specifically determines the temporal-spatial patterns of PIN3 and PIN7 transcription that are closely associated with their preferential functions during root responses to gravity.

Flavonols Mediate Root Phototropism and Growth through Regulation of Proliferation-to-Differentiation Transition

“…In roots, PHOT1 is mainly expressed in the transition zone (Sakamoto and Briggs, 2002;Wan et al, 2012), where dividing cells lose the mitotic potential and start to elongate and mature. Tropic responses, which involve organ curvature, occur due to asymmetric growth between sides of the root and normally correlate with an asymmetric distribution of the plant hormone auxin (Mähönen et al, 2014;Wang et al, 2015). Reorientation of root growth during the light avoidance response might require a local response in the transition zone mediated by PHOT1 (Zhang et al, 2014).…”

PIN7 auxin carrier is a terminator of radial root expansion inArabidopsis thaliana

“…Currently, little is known about transcription factors that may differentially impact on columella PIN expression in LRs. Notably, transcription factors MYB88 and FOUR LIPS were suggested to regulate both PIN3 and PIN7 expression in LRs [13]. It accordingly remains to be seen how the preferential and developmentally defined expression of PIN7 is molecularly achieved.…”

A Genome-Scale Analysis of the PIN Gene Family Reveals Its Functions in Cotton Fiber Development

“…The plant phytohormone, auxin, plays a crucial role in various developmental processes, such as root development, apical dominance, embryo formation, vascular differentiation, tropism, and plant response to internal and external stimuli (Dubrovsky et al, 2008; Mashiguchi et al, 2011; Rakusova et al, 2015; Wang H.Z. et al, 2015; Xi et al, 2016).…”

“…Both PIN types have been reported to participate in various developmental processes (Petrásek et al, 2006; Habets and Offringa, 2014; Wang H.Z. et al, 2015; Omelyanchuk et al, 2016).…”