Induction and suppression of rice innate immunity

Abstract

The rice plant is infected by a number of pathogens which cause significant losses of yield. Plants possess inducible innate immunity by which they can perceive danger and mount defense responses. Recognition of the pathogen is a crucial step in induction of plant immune responses. Plants can recognise a wide category of molecules related either to conserved components of pathogen structures, pathogen secreted molecules or plant damage-associated molecules. Recognition of these molecules/elicitors by receptors initiates a signal transduction cascade which includes phosphorylation of various intermediate proteins, influx of calcium ions, production of reactive oxygen species and synthesis of phytohormones. The signaling intermediates also activate transcription factors leading to enhanced expression of genes related to defense associated functions. As immune responses are energy intensive processes, they are tightly regulated through phosphorylation/dephosphorylation events or through degradation of signalling intermediates. The activation of plant innate immunity suppresses multiplication and spread of pathogen within the host tissues. In this review we discuss about key molecular players involved in rice immune responses.