Fig. 1 Phylogenetic analysis of WRKYⅡe subfamily members from Arabidopsis，tomato，and pepper A：Phylogenetic analysis of WRKYⅡe subfamily members in pepper（Ca），tomato（Sl），and Arabidopsis（At）；B：Phylogenetic analysis of WRKYⅡe subfamily members in pepper（Ca）and tomato（Sl）. The tree was constructed using the maximum likelihood method

Fig. 2 Multiple sequence comparison of WRKY domains in pepper CaWRKY27，tomato SlWRKY79，and Arabidopsis AtWRKY65 The amino acids highlighted in the red box represent the conserved residues found in WRKYⅡe subfamily members. At：Arabidopsis thaliana；Ca：Capsicum annuum；Sl：Solanum lycopersicum

Fig. 3 The distribution of main cis-elements in the promoter region of the pepper CaWRKY27

Fig. 4 The expression pattern of the SA signaling pathway-related defence genes CaPR1，CaPR1L，and CaPR5 in CaWRKY27-silenced and control pepper plants ** P < 0.01

Fig. 5 EMSA for the binding of the pepper CaWRKY27 to the promoters of target genes CaPR1 and CaPR1L A：Schematic diagram of the oligonucleotide probes used in the EMSA experiments；B：EMSA detection of binding of CaWRKY27 to CaPR1 and CaPR1L promoters in vitro. MBP protein and no protein were used as control，respectively，and all experimental groups were added with MBP-CaWRKY27 protein. The underlined nucleotide sequences represents the cis-acting element W-box. The symbols“+”and“-”represent presence or absence of the probe

Fig. 6 Dual-luciferase reporter assay to detect for the effect of CaWRKY27 on the promoter activity of target genes CaPR1 and CaPR1L A：Schematic diagram of the reporter vector and effector vector；B：Relative activity of the CaPR1 and CaPR1L promoters. ** P < 0.01

Fig. 7 Transient expression assay to analyze the effect of CaWRKY27 on the expression of LUC reporter gene driven by the promoters of target genes CaPR1 and CaPR1L

Fig. 8 Proposed working model of the CaWRKY27 in regulating pepper resistance to bacterial wilt SA induces the expression of the transcription factor CaWRKY27，which subsequently directly activates the expression of SA signaling pathway-related defence genes CaPR1 and CaPR1L，thereby enhancing pepper resistance to bacterial wilt