Updated project metadata. acylation also called S-palmitoylation is an important reversible protein post-translational modification in organisms. However, its function remains unknown in pathogenic fungi. Here, we found treatment of rice false fungus Ustilaginoidea virens with S-palmitoylation inhibitor 2-BP resulted in a significant decrease in fungal virulence and growth rate. Deletion of the S-acyltransferase proteins from U. virens indicated that two S-acyltransferases UvPfa3 and UvPfa4 were required for fungal virulence. Comprehensive identification of S-palmitoylation sites and proteins in U. virens revealed a total of 4089 S-palmitoylation sites were identified within 2192 proteins and S-palmitoylation proteins were involved in diverse biological processes. Interestingly, S-palmitoylation proteins were significantly enriched in mitogen-activated protein kinase (MAPK) pathway and MAP kinase UvSlt2 was confirmed to be a S-palmitoylation protein which was palmitoylated by UvPfa4. Mutations of S-palmitoylation sites in UvSlt2 resulted in significantly reduced fungal virulence and decreased kinase enzymatic activity and phosphorylation level. Molecular dynamics simulations demonstrated mutation of S-palmitoylation sites in UvSlt2 caused decreased hydrophobic solvent-accessible surface area, and thereby affected binding between the UvSlt2 enzyme and substrates. Taken together, S-palmitoylation promotes U. virens virulence through palmitoylating MAP kinase UvSlt2 by palmitoyltransferase UvPfa4 and enhancing enzymatic activity and phosphorylation level of the kinase, thereby increasing hydrophobic solvent-accessible surface area and binding activity between the UvSlt2 enzyme and its substrates. Our studies provide a framework for dissecting the biological functions of S-palmitoylation, and reveal an important role for S-palmitoylation in regulating virulence of pathogen.