Abstract：Abstract WRKY transcription factors are one of the largest families of transcription regulators in plants, and it can bind W-box in promoters of the target genes to regulate many specific transcriptional programs. This article summarized the recent advances on WRKY transcription factor functions and regulation mechanisms on biotic and abiotic stress responses in Arabidopsis and rice (Oryza sativa). The expressions of WRKY genes can be rapidly induced by many environmental signals. Many WRKY genes exhibit extensive autoregulation and cross-regulation. A single WRKY transcription factor can regulate several seemingly disparate processes, and several WRKY proteins can also work together in the same process to make the signal transduction pathway to be exactly regulated. WRKY proteins via cooperation with a diverse array of protein partners realize their functions, and they are usually phosphorylated by mitogen-activated protein kinase to modulate their activities in the nucleus. WRKY transcription factors in Group Ⅰ and Ⅱc can interact with VQ proteins that contain a short VQ motif and act as cofactors, and those in group Ⅱd contain C motif that can bind with calmodulin. In addition, the WRKY domain in RRS1-R represents an effector target 'decoy' which betrays the defense-suppressing abilities of PopP2 and AvrRps4 on their operational virulence targets, the defensive WRKY transcription factors. WRKY transcription factors play pivotal roles in regulating many stress reactions, but only a few mechanisms on signaling and transcriptional regulations are characterized more clearly. This article has revealed a corner of the complex regulatory network, and may help researchers to further understand the regulatory mechanisms of WRKY transcription factors.
