REDUNDANT OR UNIQUE? DISCOVERING PHOSPHATIDYLINOSITOL-PHOSPHOLIPASES C ENZYMES THAT PLAY DISTINCT ROLES IN PLANT STRESS.

D'AMBROSSIO, JUAN MARTÍN; GONORAZKY, GABRIELA; DI FINO, LUCIANO; SCUFFI, DENISE; GUARDIA, AISHA; LAMATTINA, LORENZO; PAGNUSSAT, GABRIELA; GARCÍA-MATA, CARLOS; LAXALT, ANA MARÍA

Corrientes

Congreso; XXI Reunión Anual de Fisiología Vegetal; 2016

Sociedad Argentina de Fisiología Vegetal

In plants, the phosphoinositide-specific phospholipases C (PI-PLCs) have a role in signal transduction during development and (a) biotic responses. PI-PLC catalyzes the hydrolysis of the signal molecule PI(4,5)P2 to generate IP3 anddiacylglycerol which is further phosphorylated to phosphatidic acid (PA).Plant genomes contain numerous genes coding for PI-PLCs: Arabidopsis has 9 members (AtPLC1 - AtPLC9) and tomato 6 (SlPLC1 ?SlPLC6). Our main goal is to decipher the role of each gene in the different physiological responses.The activation of PI-PLC is one of the earliest plant defence responses. We showed that tomato SlPLC2 is required for xylanase-induced basal defence and for susceptibility to the necrotrophic fungus Botrytis cinerea. In Arabidopsis, AtPLC2 is required for flagellin-induced basal defence and resistance against low virulent Pseudomonas and non-adapted powdery mildew fungi.Serendipitously, we found out that AtPLC2 is also involved in both reproductive- and embryo development.ABA is the master hormone governing the complex network of molecules that determine the stomatal aperture. PI-PLC activity is required for ABA-dependent stomatal closure. We find out that AtPLC3 and AtPLC7 were required for ABA induction of stomatal closure.All together our results suggest that PLCs are unique and play distinct roles in different physiological responses.