Genome-wide and transcriptome analyses reveal RcCDPK5 as a positive regulator mediating resistance to Botrytis cinerea in Rosa chinensis

CDPKs serve as essential signaling components in a plant's response to both biotic and abiotic stress. While the CDPK gene family's role in Rosaceae is recognized, its function in rose remains unclear. In this study, we identified and classified 297 CDPK genes from ten Rosaceae species into five subfamilies. Gene duplication analyses revealed WGD/segmental duplication and dispersed duplication as key drivers for the CDPK gene family in rose, with Ka/Ks ratios suggesting strong purifying selection. Promoter analysis revealed an enrichment of cis -elements related to hormone and stress responses. WGCNA of B. cinerea -treated samples suggested strong correlations with WRKY , ERF , and NAC transcription factors. Expression analysis showed that six RcCDPK genes were induced by B. cinerea infection, suggesting their potential role in rose resistance. Functional validation via VIGS demonstrated that RcCDPK5 is required for rose resistance against B. cinerea . Furthermore, Y1H and Dual-LUC experiments showed that RcNAC51, as a transcriptional activator, binds to the promoter of RcCDPK5 and activates the expression of RcCDPK5 , thereby enhancing the defense of rose against B. cinerea . Our finding elucidates a transcriptional regulatory cascade involving RcNAC51 and RcCDPK5 , providing a foundation for understanding CDPK-mediated defense in Rosaceae. • Gray mold is the most serious disease of rose during cultivation and post-harvest. • We studied the CDPK gene family evolution and expression in ten Rosaceae species and rose. • We demonstrated that RcCDPK5 is essential for resistance to B. cinerea . • Furthermore, RcNAC51 activates RcCDPK5 expression, enhancing resistance to B. cinerea . • Our work provides resources for rose CDPK and ornamental crop improvement.