Studies on Innate Immunity in Rice

Plants have developed a precisely regulated innate immune machinery to defend themselves against potential microbial attack, through two innate immune systems: the first layer of immunity is activated on detection of conserved pathogen-associated molecular patterns(PAMP) by cell surface pattern-recognition receptors, resulting in PAMP-triggered immunity(PTI); the second layer of immunity is dependent on recognition of pathogen-secreted effectors by host specific disease resistance(R) gene-encoding proteins, leading to race-specific effector-triggered immunity(ETI). With increasing information of isolation of R genes, key defense regulators and pathogen effectors, mechanisms involved in rice immunity have been largely revealed. This review focuses on PTI, ETI and respective downstream signals and key components, which have been revealed recently, and provides an emerging vision of the immunity network in rice.