CaWRKY27通过调控CaPR1和CaPR1L的表达介导辣椒对青枯菌的免疫OA

The WRKY transcription factors,which are specific to plants,play a crucial role in regulating salicylic acid(SA)-mediated immune response.CaWRKY27,a member of the CaWRKYⅡe subfamily,is implicated in modulating the resistance of pepper plants to bacterial wilt.To further elucidate the mechanism of action of CaWRKY27 gene in pepper's resistance to bacterial wilt,five members of the CaWRKYⅡe subfamily were identified within the pepper genome.Phylogenetic analysis and multiple amino acid sequence alignment revealed that CaWRKY27 exhibits a high degree of homology with SlWRKY79 from tomato and AtWRKY65 from Arabidopsis.Real-time quantitative PCR(RT-qPCR)analysis demonstrated that the expression levels of the pathogenesis-related genes CaPR1 and CaPR1L were significantly reduced in pTRV2-CaWRKY27(CaWRKY27 silencing)plants compared to at both 24 and 48 hours post-inoculation with Ralstonia solanacearum in pepper.Furthermore,both dual-luciferase reporter(DLR)assays and electrophoretic mobility shift assays(EMSA)revealed that CaWRKY27 can directly bind to the W-box in the promoters of the CaPR1 and CaPR1L genes,thereby activating their expression.These findings indicate that CaWRKY27 plays a crucial role in the resistance to bacterial wilt by directly regulating the expression of SA signaling pathway-related genes CaPR1 and CaPR1L in pepper.