PLD alpha 1 and PLD delta are involved in NO induced stomatal closure

AYELEN DISTÉFANO; CARLOS GARCIA-MATA; LORENZO LAMATTINA; ANA MARÍA LAXALT

Mar del Plata, Argentina

Congreso; XLIII Reunión Anual; 2007

SAIB

Previously we showed, in Vicia faba guard cells, that nitric oxide (NO) induces stomatal closure via activation of phospholipase D (PLD) with the consequent production of phosphatidic acid (PA). Since these evidences are biochemical and pharmacological, our current goal is to unravel the signaling players by means of genetics. Multiple PLD isozymes exist, Arabidopsis has 12 with distinguishable biochemical and regulatory properties, and also with little functional redundancy. Two isoforms (PLD1 and ) had been related to stomatal closure and drought response upon ABA treatments. Thus, our aim is to determine whether PLD1 and PLD are required for NO induced stomatal closure. As a measure of stomatal closure the relative water content (RWC) and the loss of fresh weight (LFW) were determinate. NO treated wild type plants shows an increase in RWC and less LFW than non-treated plants, reflecting the fact that NO induces stomatal closure. The same NO treatment has no effects on RWC and LFW in pld1 and pld mutants, which indicates that NO fail to induce stomatal closure in these plant. These results suggest that during stomatal closure NO could be activating PA accumulation via PLD1 and PLD. Futures studies will be done to directly measure stomatal closure and in vivo PLD activity upon NO treatments in Arabidopsis.