SRM1 phosphorylation coordinates plant immunity and growth in Arabidopsis
Plants mount an array of immune response to combat pathogen invasion, which, however, often accompanied by growth inhibition. How plants coordinate immunity and growth is intriguing and of great significance in agriculture. Here, we reported a MYB-related transcription factor SRM1 positive regulates plant immunity and meanwhile, also promotes plant growth in Arabidopsis thaliana. SRM1 can directly bind the promoters of core immune factor EDS1 and anthocyanin synthesis gene DFR to activate their expression for disease resistance. Notably, SRM1 can also promote plant growth by directly activating the expression of PORA for chlorophyll synthesis. Under normal conditions, SRM1 undergo ubiquitination and be degraded by 26S proteasome to maintain at lower level. Upon pathogens infection, SRM1 interacts with and be phosphorylated by MPK3/6. Phosphorylated SRM1 is more stable and accumulated at higher level to enhance plant resistance. In conclusion, SRM1 can coordinate plant growth and defense through post-translational modifications. The evolutionarily conservation of SRM1 in plants provides clue for breeding crops with balanced disease resistance and yield.