The PP2A-like phosphatase SsPpe1 regulates Ssrot1 to modulate sexual mating and virulence in Sporisorium scitamineum

Abstract Protein phosphatase 2A (PP2A) is a heterotrimer enzyme composed of a catalytic subunit (C), a scaffolding subunit (A), and a regulatory subunit (B). PP2A phosphatases play crucial roles in many biological processes, including protein synthesis, cellular signaling, cell cycle regulation, apoptosis, virulence, and stress responses. However, the roles of PP2A in the pathogenic fungi Sporisorium scitamineum remain unclear. In this study, we report the identification of a homologue of PP2A-like phosphatase designated as SsPpe1. We found that Ssppe1 is required for sexual mating/filamentation and virulence in S. scitamineum . Reintroducing the wild-type Ssppe1 allele with its native promoter into the mutant strain restored the wild-type phenotypes. Additionally, the deletion of Ssppe1 resulted in a significant decrease in the transcript levels of the pheromone pathway-related genes. Global transcriptome analysis revealed that SsPpe1 was involved in the intrinsic component of the membrane, oxidoreductase activity, sulfur amino acid biosynthetic process, carbon–carbon lyase activity, and glutamine family amino acid metabolic process. Moreover, Ssppe1 modulated the transcriptional expression of the cell wall integrity-related gene Ssrot1 . Deletion of Ssrot1 resulted in defects in sexual mating and filamentation, as well as reduced virulence. Our results provide insight into the regulatory roles of SsPpe1 in S. scitamineum and contribute to our understanding of the function of the PP2A-like in plant-pathogenic fungi.