Redundant or unique? Discovering phosphatidylinositol-phospholipases C enzymes that play distinct roles in plant stress

D'AMBROSIO JM; GONORAZKY, AG; DI FINO L; SCUFFI D; GUARDIA A; LAMATTINA L; PAGNUSSAT, G.; GARCIA-MATA, C.; LAXALT AM

Corrientes

Conferencia; XXXI RAFV; 2016

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 and diacylglycerol 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.