The Subtilisin-Like Protease Bcser2 Affects the Sclerotial Formation, Conidiation and Virulence of .

, a ubiquitous necrotrophic plant-pathogenic fungus, is responsible for grey mold and rot disease in a very wide range of plant species. Subtilisin-like proteases (or subtilases) are a very diverse family of serine proteases present in many organisms and are reported to have a broad spectrum of biological functions. Here, we identified two genes encoding subtilisin-like proteases ( and ) in the genome of both of which contain an inhibitor I9 domain and a peptidase S8 domain. The expression levels of and increased during the sclerotial forming stage, as well as during a later stage of hyphal infection on leaves, but the up-regulation of was significantly higher than that of . Interestingly, deletion of had no effect on the fungal development or virulence of However, deletion of or double deletion of and severely impaired the hyphal growth, sclerotial formation and conidiation of . We also found that and / could not form complete infection cushions and then lost the ability to infect intact plant leaves of and tomato but could infect wounded plant tissues. Taken together, our results indicate that the subtilisin-like protease is crucial for the sclerotial formation, conidiation, and virulence of .