Abstract
Plants possess defense mechanisms to protect themselves from pathogen attack. Previously, we showed that OsRac1, a small GTPase Rac homolog of rice, plays a general role in disease resistance of rice. In this study, to identify effectors that interact with OsRac1 during defense responses, we carried out affinity chromatography of OsRac1. The identified proteins included RWD which has been identified as a rice homolog of a receptor for activated C-kinase 1 (RACK1). RWD/OsRACK1 RNAi transgenic plants were lethal. The plants overexpressing RWD/OsRACK1 showed constitutive expression of PBZ1 and HR-like response when they were inoculated with a compatible rice blast race 007. Production of hydrogen peroxide induced by sphingolipid elicitor was suppressed in both RWD/OsRACK1 overexpressing and RNAi transgenic cultured cells. Taken together, the results suggest that RWD/OsRACK1 is involved in plant immunity through G protein pathway.
