Apoplastic Class-III Peroxidases COLD1 and COLD2 regulate ROS-homeostasis linked to root hair growth at low-temperature in Arabidopsis thaliana

PHILIPPE RANOCHA; LUCAS SERVI; JUAN MANUEL PERALTA; DIANA R. RODRIGUEZ GARCIA; MARCELO JAVIER YANOVSKY; FEDERICO ARIEL; JOSE ESTEVEZ; LUCIANA KASULIN; PATRICIO TAPIA; CECILIA BORASSI; YOSSMAYER DEL CARMEN RONDON GUERRERO; JAVIER BOTTO; EZEQUIEL PETRILLO; JAVIER MARTINEZ-PACHECO; CORINA M. FUSARI; VICTORIA BERDION GABARAIN; ELIANA MARZOL; MARIANA CARIGNANI SARDOY; CLAUDIO MENESES; CHRISTOPHE DUNAND

Congreso; XXXIII Argentinian meeting of Plant Physiology (RAFV2021); 2021

Root hairs (RH) growth is under the control of endogenous and external environmental signals that regulate its final cell size. RHs are part of the active surface root area crucial for nutrient uptake and water absorption. Previously, we have determined that the low-temperature treatment at 10°C is able to trigger, unexpectedly, an exacerbated RH growth compared to the room-temperature. This conditional RH growth at low-temperature was linked to a reduced nutrient availability in the media. Here, we explore the molecular basis of this strong RH growth response by using the Genome Wide Association Studies (GWAS) approach on Arabidopsis thaliana accessions. We identified an uncharacterized PEROXIDASE COLD1 as a key protein triggering the end of conditional growth under a moderate temperature stress. In addition, we also identified a related PEROXIDASE COLD2 to be associated to this growth condition. Double cold1/cold2 mutant and the overexpressor COLD1 and COLD2 lines showed contrasting RH phenotypes, peroxidase activities and cyt/apoROS levels. Collectively, both COLD1 and COLD2 are key apoplastic PRXs that modulates ROS-homeostasis linked RH elongation at low-temperature.