An enhancer–promoter-transcription factor module orchestrates plant immune homeostasis by constraining camalexin biosynthesis
During immune activation in Arabidopsis thaliana, the enhancer CORE PATTERN-INDUCED ENHANCER 35 (CPIE35) activates the transcription of WRKY15 by forming chromatin loops with the promoter of WRKY15 in a WRKY18/40/60-, WRKY33-, and MYC2-dependent manner. WRKY15, in turn, suppresses the expression of PAD3 and GSTU4, inhibiting camalexin synthesis and therefore decreasing plant resistance to pathogenic fungi. Notably, the CPIE35 region is evolutionarily conserved among Brassicaceae plants, and the CPIE35-WRKY15 module exerts similar functions in Brassica napus to negatively regulate antifungal resistance.
