iTRAQ-Based Quantitative Proteomics Reveals as a Novel Virulence Factor in .

is an important hemibiotrophic fungal pathogen that causes anthracnose disease on various cruciferous plants. Discovery of new virulence factors could lead to strategies for effectively controlling anthracnose. Acyl-CoA binding proteins (ACBPs) are mainly involved in binding and trafficking acyl-CoA esters in eukaryotic cells. However, the functions of this important class of proteins in plant fungal pathogens remain unclear. In this study, we performed an isobaric tags for relative and absolute quantification (iTRAQ)-based quantitative proteomic analysis to identify differentially expressed proteins (DEPs) between a nonpathogenic mutant Δ and the wild type. Based on iTRAQ data, DEPs in the Δ mutant were mainly associated with melanin biosynthesis, carbohydrate and energy metabolism, lipid metabolism, redox processes, and amino acid metabolism. Proteomic analysis revealed that many DEPs might be involved in growth and pathogenesis of Among them, an acyl-CoA binding protein, ChAcb1, was selected for further functional studies. Deletion of caused defects in vegetative growth and conidiation. is also required for response to hyperosmotic and oxidative stresses, and maintenance of cell wall integrity. Importantly, the Δ mutant exhibited reduced virulence, and microscopic examination revealed that it was defective in appressorial penetration and infectious growth. Furthermore, the Δ mutant was impaired in fatty acid and lipid metabolism. Taken together, was identified as a new virulence gene in this plant pathogenic fungus.