An oomycete avirulence effector stabilizes a plant RNA binding protein to subvert host immunity
J. HUANG (1), J. Huang (2) (1) Nanjing Agricultural University, China; (2) Nanjing Agricultural University, Nanjing, China, China

Avirulence (AVR) effectors, recognized by host resistant protein, are a group of key players in plant-microbe interactions. However, how AVR effectors manipulate plant immunity remains poorly characterized. The AVR effector PsAvr3c from soybean (Glycine max) root rot pathogen Phytophthora sojae is recognized by the soybean Rps3c receptor in a nuclear dependent manner. PsAvr3c also functions as a virulence protein to enhance Phytophthora colonization. Recently, we identified two soybean serine/arginine rich proteins GmASF1 and GmASF2 as interactors of PsAvr3c. We demonstrate that PsAvr3c physically interacts with GmASF1/2 and stabilizes GmASFs proteins in vivo. The GmASFs are conserved proteins in plants without any predicted functional domains other than three serine/arginine/lysine rich repeat regions and a nuclear localization signal. Transient gene silencing and over-expression of GmASF1/2 in soybean hairy roots indicates that GmASF1/2 are susceptibility factors. Furthermore, biochemical assays suggest that GmASFs possesses RNA binding activity in vitro, and this ability is enhanced in the presence of PsAvr3c. In summary, these findings provide evidence that a pathogen AVR effector targets a previously unidentified RNA binding protein to subvert plant immunity.

Abstract Number: P9-261
Session Type: Poster