RT Journal Article
SR Electronic
T1 The molecular link between auxin and ROS-Mediated polar root hair growth
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 116517
DO 10.1101/116517
A1 Silvina Mangano
A1 Silvina Paola Denita-Juarez
A1 Hee-Seung Choi
A1 Eliana Marzol
A1 Youra Hwang
A1 Philippe Ranocha
A1 Silvia Melina Velasquez
A1 Cecilia Borassi
A1 María Laura Barberini
A1 Ariel Alejandro Aptekmann
A1 Jorge Prometeo Muschietti
A1 Alejandro Daniel Nadra
A1 Christophe Dunand
A1 Hyung-Taeg Cho
A1 José Manuel Estevez
YR 2017
UL http://biorxiv.org/content/early/2017/03/14/116517.abstract
AB Root hair polar growth is endogenously controlled by auxin and sustained by oscillating levels of reactive oxygen species (ROS). These cells extend several hundred-fold their original size toward signals important for plant survival. Although their final cell size is of fundamental importance, the molecular mechanisms that control it remain largely unknown. Here, we show that ROS production is controlled by the transcription factors RSL4, which in turn is transcriptionally regulated by auxin through several Auxin Responsive Factors (ARFs). In this manner, auxin controls ROS-mediated polar growth by activating RSL4, which then upregulates the expression of genes encoding NADPH oxidases (also known as RBOHs, RESPIRATORY BURST OXIDASE HOMOLOG proteins) and Class-III Peroxidases (PER), which catalyse ROS production. Chemical or genetic interference with the ROS balance or peroxidase activity affect root hair final cell size. Overall, our findings establish a molecular link between auxin regulated ARFs-RSL4 and ROS-mediated polar root hair growth.Significance Statement Tip-growing root hairs are excellent model systems to decipher the molecular mechanism underlying reactive oxygen species (ROS)-mediated cell elongation. Root hairs are able to expand in response to external signals, increasing several hundred-fold their original size, which is important for survival of the plant. Although their final cell size is of fundamental importance, the molecular mechanisms that control it remain largely unknown. In this study, we propose a molecular mechanism that links the auxin-Auxin Response Factors (ARFs) module to activation of RSL4, which directly targets genes encoding ROS-producing enzymes, such as NADPH oxidases (or RBOHs) and secreted type-III peroxidases (PERs). Activation of these genes impacts apoplastic ROS homeostasis, thereby stimulating root hair cell elongation.