NITRIC OXIDE MEDIATES VESICLE TRAFFICKING OF PIN2 AUXIN TRANSPORTER IN Arabidopsis

MARÍA MAGDALENA, VAZQUEZ; SILVANA LORENA, COLMAN; MARÍA CECILIA, TERRILE; MARISA, OTEGUI; CLAUDIA A, CASALONGUÉ; RAMIRO PARIS

Mar del Plata

Congreso; 51 Annual Meeting Argentine Society for Biochemistry and Molecular Biology. LI Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2015

SAIB

The plant hormone auxin is transported from cell to cell with strict directionality by influx and efflux carrier proteins.PIN efflux transporters exhibit polar plasma membrane localization. They determine the direction and rate ofintracellular auxin flow. The subcellular localization of PIN2 protein is driven by endocytosis and recycling throughvesicle trafficking in a process termed constitutive cycling. Auxin signaling trough SCF TIR1/AFBs complex hasbeen also involved in PIN2 endocytosis and plasma membrane localization. Recently, it has been described that TIR1auxin receptor is regulated by S-nitrosylation. In order to study the TIR1/AFB-mediated auxin signaling pathway andits regulation by S-nitrosylation in the control of PIN2 localization, pharmacological and functional approaches arebeing carried out. We found that the scavenging of endogenous nitric oxide (NO) by cPTIO impairs the auxinmediatedPIN2 plasma membrane localization. As well, we demonstrated that the physiological NO donor, GSNO,mimics the auxin action on PIN2 localization. In order to present a functional-genomic approach we crossedArabidopsis TIR1 S-nitrosylation mutants with PIN2-GFP reporter plants. Finally, the mechanisms underlying thisregulation will be discussed.