PcWRKY33 enhances Fusarium oxysporum resistance in Polygonatum Cyrtonema Hua via salicylic acid-mediated defense activation

The production of Polygonatum cyrtonema Hua is currently encountering substantial challenges due to root rot disease, primarily caused by the pathogen Fusarium oxysporum. The WRKY transcription factors play crucial roles in mediating disease resistance across a wide range of plant species; however, it is unclear whether members of this family improve resistance to F. oxysporum infection in P. cyrtonema Hua. To putatively determine the F. oxysporum responsive PcWRKY members, we analyzed full-length transcriptome sequencing data obtained after F. oxysporum infection in this study, 271 WRKY transcription factors were detected and PcWRKY33 was found to be responsive to F. oxysporum infection. Furthermore, overexpression of PcWRKY33 in both P. cyrtonema Hua and Nicotiana benthamiana increased tolerance to F. oxysporum infection, and the expression level of 20 disease-resistance genes containing the TGAC motif were regulated using transcriptome sequencing analysis post-inoculation with F. oxysporum in PcWRKY33 overexpression seedlings. We also determined that F. oxysporum infection increased both the endogenous salicylic acid (SA) content and the expression of disease-resistant genes in PcWRKY33-overexpressing plants. Our results demonstrated that PcWRKY33 plays an important role in the resistance of P. cyrtonema Hua to F. oxysporum by influencing SA signaling.