BARLEY INTERACTION WITH POWDERY MILDEW FUNGUS: HOW PROTEIN KINASES REGULATE DEFENSE TRANSCRIPTIONS

Qian-Hua Shen

Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China

Abstract

Upon recognition of pathogens, plant immune receptors trigger immune responses that usually involve massive defense transcription reprogramming. Although numerous transcription factors (TFs) were identified to regulate plant defense responses, the upstream components that regulate these TFs are largely unknown. We have identified different types of TFs that are involved in barley disease resistance against powdery mildew fungus, including WRKY1, WRKY2 and WRKY3 of the same subfamily, and MYB6. We report here that different TFs are targeted by different upstream protein kinases for phosphorylation, and thus regulation of their activity and/or stability. We found that WRKY3 is specifically phosphorylated by SnRK1 at both conserved and non-conserved motifs, while WRKY1 can be phosphorylated by MPK4a that, interestingly, can also phosphorylates MYB6. MYB6 and WRKY1 were previously shown to interact with each other. Functional analyses and potential crosstalk between different protein kinase cascades will be further addressed.