Interaction Between Glycoside Hydrolase FsGH28c from and PnPUB35 Confers Resistance in .

Pathogens deploy various molecular mechanisms to overcome host defenses, among which glycoside hydrolases (GHs) play a critical role as virulence factors. Understanding the functional roles of these enzymes is essential for uncovering pathogen-host interactions and developing strategies for disease management. wilt has occurred in the main cultivation regions, which seriously affects the yield and quality of . Here, we identified and characterized FsGH28c, a GH28 family member in . Its expression was significantly upregulated during the infection of black pepper (Piper nigrum) roots by cv. WN-1, indicating its potential role in pathogenicity. elicited cell death in and modulated the expression of genes related to pathogenesis. exerts a positive influence on the pathogenicity of . The knockout of mutant strains markedly attenuated 's virulence in black pepper plants. The knockout mutant strains decrease the ability of to utilize carbon sources. The deletion did not affect mycelial growth on PDA but did impact spore development. We identified a U-box protein, PnPUB35, interacting with FsGH28c using yeast two-hybrid and bimolecular fluorescence complementation assays. PnPUB35 conferred enhanced resistance to in black pepper through positive regulation. These findings suggest that FsGH28c may function as a virulence factor by modulating host immune responses through its interaction with PnPUB35.