587 / 2019-05-01 20:25:43

NRG1 proteins stabilize R proteins to regulate immunity in Arabidopsis

R protein,NRG1,Defense response,Autoimmunity

全体主题 > Plant Microbe Interactions & Microbiomes

Plants have developed complex defense mechanisms to adapt to different biotic stresses. Plant cell surface receptors recognize conserved molecules produced by the pathogens, triggering the first layer of defense response. The second layer of defense is mediated by resistance (R) protein, which recognizes effector proteins secreted by pathogens to activate a strong defense response, that often leads to programmed cell death of the infected cells. Previously we identified NUDT6 and 7 as negative regulators of defense responses. Here, by using the Arabidopsis autoimmunity mutant, nudt6/7, we carried out a suppressor screen to identify genes that regulate plant immunity, leading to the identification of two homologs of the tobacco NRG1 gene (N requirement Gene1). The atnrg1.1/1.2 double mutations also suppressed the phenotype of several autoimmunity mutants. However, the double mutant didn't show obvious defect in disease resistance toward several avirulent bacterial strains. Overexpression of either of the AtNRG1 genes led to EDS1-dependent autoimmunity phenotype. AtNRG1s are required for several R proteins' accumulation. Coimmunoprecipitation assay shows that NRG1s didn't directly interact with EDS1. We propose that as the helper R proteins, NRG1s stabilize R proteins to regulate plant immunity in Arabidopsis.