Extracellular ATP, nitric oxide and superoxide act co-ordinately to regulate hypocotyl growth in etiolated Arabidopsis seedlings

TONÓN CV, TERRILE MC, IGLESIAS MJ, LAMATTINA L AND CASALONGUÉ C

JOURNAL OF PLANT PHYSIOLOGY

ELSEVIER GMBH

Año: 2010 vol. 167 p. 540 - 546

0176-1617

Etiolated Arabidopsisthaliana seedlings germinated in the presence of reducing buffers Duch as reduced gluthathione (GSH) and dithiothreitol (DTT) have altered morphology. GSH and DTT inhibited hypocotyl elongation in a dose-dependent manner. The GSH-mediated effect was prevented by the simultaneous addition of extracellular ATP (eATP). NADPH oxidase (NOX) activity and endogenous nitric oxide (NO) generation were required to mediate eATP action on the hypocotyls elongation. A correlation was observed between hypocotyls length, eATP concentration and NO production. The action of eATP and NO on superoxide accumulation and peroxidase activity was investigated. The O2- distribution was regulated by eATP and NO during hypocotyls elongation. Our data suggest that a finely tuned balance of redox status and optimal levels of ATP and NO are essentiall to regulate the hypocotyls elongation in the dark.