Phospholipase C 2 affects MAMP-Triggered Immunity by Modulating ROS Production

COUTO D; LAMATTINA L; ALVAREZ ME; FABRO G ; MUNNIK T; ZIPFEL C; D´AMBROSIO JM; SCUFFI D; ANDERSSON MX; LAXALT AM

PLANT PHYSIOLOGY.

AMER SOC PLANT BIOLOGISTS

Lugar: Rockville; Año: 2017 vol. 175 p. 970 - 981

0032-0889

The activation of phosphoinositide-specific phospholipase C (PI-PLC) is one84 of the earliest responses triggered by the recognition of several microbe85associated molecular patterns (MAMPs) in plants. The Arabidopsis PI-PLC86 gene family is composed of nine members. Previous studies suggested a role87 for PLC2 in MAMP-triggered immunity (MTI) as it is rapidly phosphorylated in88 vivo upon treatment with the bacterial MAMP flg22. Here we analyzed the role89 of PLC2 in plant immunity using an artificial microRNA to silence PLC290 expression in Arabidopsis. We found that PLC2-silenced plants are more91 susceptible to the type III secretion system-deficient bacterial strain92 Pseudomonas syringae pv. tomato (Pst) DC3000 hrcC- (Pst DC3000 hrcC-)93 and to the non-adapted pea powdery mildew Erysiphe pisi. However, PLC2-94 silenced plants display normal susceptibility to virulent (Pst DC3000) and95 avirulent P. syringae strains (Pst DC3000 AvrRPM1), conserving typical96 hypersensitive response (HR) features. In response to flg22, PLC2-silenced97 plants maintain wild-type MAPK activation and PHI1, WRKY33 and FRK198 immune marker gene expression, but have reduced reactive oxygen species99 (ROS)-dependent responses such as callose deposition and stomatal closure.100 Accordingly, the generation of ROS upon flg22 treatment is compromised in101 the PLC2-defficient plants suggesting an effect of PLC2 in a branch of MTI102 and non-host resistance that involves early ROS-regulated processes.103 Consistently, PLC2 associates with the NADPH oxidase RBOHD, suggesting104 its potential regulation by PLC2.