Subtilases represent the second largest subfamily of serine proteases, and are important for various biological processes. However, the biological function of subtilases has not been systematically characterized in plant pathogens. In present study, 32 subtilases were identified in the genome of wheat scab fungus Fusarium graminearum, a devastating cereal plant pathogen. Deletion mutants of each subtilase were obtained and functionally characterized. Among them, the deletion of FgPrb1 resulted in greatly reduced virulence of F. graminearum. The regulatory mechanisms of FgPrb1 in virulence were investigated in details. Our results showed that the loss of FgPrb1 led to defects in deoxynivalenol (DON) production, responses to environmental stimuli, and lipid metabolism. Additionally, we found that FgPrb1 was involved in autophagy regulation. Taken together, the systematic functional characterization of subtilases showed that the FgPrb1 of F. graminearum is critical for plant infection by regulating multiple different cellular processes.

枯草杆菌酶代表丝氨酸蛋白酶的第二大亚科，对各种生物过程很重要。然而，枯草杆菌酶的生物学功能尚未在植物病原体中系统地表征。在本研究中，在小麦赤霉病真菌Fusarium graminearum（一种破坏性的谷物植物病原体）的基因组中鉴定出 32 种枯草杆菌酶。获得每种枯草杆菌酶的缺失突变体并对其进行功能表征。其中，FgPrb1的缺失导致禾谷镰刀菌毒力大大降低. 详细研究了FgPrb1的毒力调控机制。我们的结果表明，FgPrb1 的缺失导致脱氧雪腐镰刀菌烯醇 (DON) 的产生、对环境刺激的反应和脂质代谢的缺陷。此外，我们发现 FgPrb1 参与自噬调节。总之，枯草杆菌酶的系统功能表征表明，禾谷镰刀菌的 FgPrb1通过调节多种不同的细胞过程对植物感染至关重要。