Complex regulation of an R gene SNC1 revealed by autoimmune mutants

Abstract

Plants have evolved resistance (R) proteins to detect pathogen effectors and trigger plant defense responses in the so named effector-triggered immunity (ETI). R proteins are under negative regulation in plants as upregulated activation of R protein is detrimental to plant growth. Autoimmune mutants have been instrumental in understanding the fine tuning of plant defense responses. Recently, a number of such mutants have been molecularly characterized, and some of them result from over-activation of SNC1, a TIR-NBS-LRR type of R protein. Studies of these mutants revealed a complex negative regulation of SNC1 activity from transcriptional to posttranslational regulation. Here, we summarize studies on these SNC1-dependent autoimmune mutants and discuss the fine regulation of R proteins in plant immunity. © 2012 Landes Bioscience.