Post-translational regulation of WRKY transcription factors in plant immunity

Plants have evolved immune system to protect themselves against invading pathogens. Recent research has illustrated that signaling networks, after perception of diverse pathogen-derived signals, facilitate transcriptional reprogramming through mitogen-activated protein kinase (MAPK) cascades. WRKY proteins, which comprise a large family of plant transcription factors, are key players in plant immune responses. WRKY transcription factors participate in the control of defense-related genes either as positive or as negative regulators, and essentially are regulated at the transcriptional level. Emerging evidence emphasizes that group I WRKY transcription factors, which contain a conserved motif in the N-terminal region, are also activated by MAPK-dependent phosphorylation, underlining their importance in plant immunity.

► R protein–WRKY association interferes with the WRKY repressor function, resulting in effector-triggered immunity.
► Group I WRKY transcription factors, which contain a conserved motif in the N-terminal region, are activated by MAPK-dependent phosphorylation.
► MAPK substrates employ D-domain sequences to determinate the range of MAPKs and to promote MAPK-mediated phosphorylation.