PLC2 Regulates MAMP-Triggered Immunity by Modulating ROS Production in Arabidopsis

D'AMBROSIO, JUAN MARTÍN; COUTO, DANIEL; FABRO, GEORGINA; SCUFFI, DENISE; LAMATTINA, LORENZO; MUNNIK, TEUN; ANDERSSON, MATS X.; ALVAREZ, MARIA ELENA; ZIPFEL, CYRIL; LAXALT, ANA M

PLANT PHYSIOLOGY.

AMER SOC PLANT BIOLOGISTS

Año: 2017 p. 970 - 981

0032-0889

The activation of phosphoinositide-specific phospholipase C (PI-PLC) is one of the earliest responses triggered by the recognition of several microbe-associated molecular patterns (MAMPs) in plants. The Arabidopsis PI-PLC gene family is composed of nine members. Previous studies suggested a role for PLC2 in MAMP-triggered immunity (MTI) as it is rapidly phosphorylated in vivo upon treatment with the bacterial MAMP flg22. Here we analyzed the role of PLC2 in plant immunity using an artificial microRNA to silence PLC2 expression in Arabidopsis. We found that PLC2-silenced plants are more susceptible to the type III secretion system-deficient bacterial strain Pseudomonas syringae pv. tomato (Pst) DC3000 hrcC- (Pst DC3000 hrcC-) and to the non-adapted pea powdery mildew Erysiphe pisi. However, PLC2-silenced plants display normal susceptibility to virulent (Pst DC3000) and avirulent P. syringae strains (Pst DC3000 AvrRPM1), conserving typical hypersensitive response (HR) features. In response to flg22, PLC2-silenced plants maintain wild-type MAPK activation and PHI1, WRKY33 and FRK1 immune marker gene expression, but have reduced reactive oxygen species (ROS)-dependent responses such as callose deposition and stomatal closure. Accordingly, the generation of ROS upon flg22 treatment is compromised in the PLC2-defficient plants suggesting an effect of PLC2 in a branch of MTI and non-host resistance that involves early ROS-regulated processes. Consistently, PLC2 associates with the NADPH oxidase RBOHD, suggesting its potential regulation by PLC2.