The molecular link between auxin and ROS-mediated polar growth

SILVINA MANGANO, SILVINA PAOLA DENITA-JUAREZ, HEE-SEUNG CHOI, ELIANA MARZOL,ET. AL. & JOSÉ MANUEL ESTEVEZ

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

NATL ACAD SCIENCES

Lugar: Washington DC, USA; Año: 2017

0027-8424

Roothair polar growth is endogenously controlled by auxin and sustained byoscillating levels of reactive oxygen species (ROS). These cells extend severalhundred-fold their original size toward signals important for plant survival. Althoughtheir final cell size is of fundamental importance, the molecular mechanismsthat control it remain largely unknown. Here, we show that ROSproduction is controlled by the transcription factors RSL4, which in turn is transcriptionallyregulated by auxin through several Auxin Responsive Factors (ARFs). In thismanner, auxin controls ROS-mediated polar growth by activating RSL4, which thenupregulates the expression of genes encoding NADPH oxidases (also known as RBOHs, RESPIRATORYBURST OXIDASE HOMOLOG proteins) and Class-III Peroxidases (PER), which catalyse ROSproduction. Chemical or genetic interference with the ROS balance or peroxidaseactivity affect root hair final cell size. Overall, our findings establish a molecularlink between auxin regulated ARFs-RSL4 and ROS-mediated polar root hair growth.