PLDalpha1 And PLDbeta; are involved in NO induced stomatal closure

DISTÉFANO, A.; GARCIA-MATA, C.; LAMATTINA, L.; ANA MARIA LAXALT

Mar del Plata

Congreso; SAIB; 2007

PL-P34. PLD alpha1 AND PLD delta ARE INVOLVED IN NO INDUCEDSTOMATALCLOSURE DistéfanoAM, García-Mata C, Lamattina L, LaxaltAM. IIB-UNMdP, CC 1245 Mar del Plata, Argentina. E-mail: adistefa@mdp.edu.ar Vicia faba pld 1 in vivo Supported by ANPCyT, CONICET, Fundación Antorchas TWAS, UNMdP. Previously we showed, in 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.Twoisoforms (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 show 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 LFWin and mutants, which indicates that NO fail to induce stomatal closure in these plants. These results suggest that during stomatal closureNOcould be activating PA accumulation via PLD 1 and PLD . Futures studies will be done to directly measure stomatal closure and PLDactivity uponNOtreatments inArabidopsis.