Whole-Genome Sequencing of Pathogenic Nigrospora musae ST1 Causing Leaf Spot Disease in Idesia polycarpa

Nigrospora musae ST1 is a newly identified pathogen responsible for leaf spot disease in Idesia polycarpa. In order to further advance our understanding of this strain and improve management strategies for the leaf spot disease, the PacBio Sequel II platform was used to perform whole-genome sequencing of N. musae ST1. The assembled genome comprised 42 contigs, with a total length of 49,259,803 bp and an average GC content of 56.23%. Functional annotation identified 12,063 protein-coding genes, including 125 Transporter Classification Database (TCDB)-related genes, 3600 pathogen host interaction (PHI) genes, 2503 Virulence Factor Database (DFVF)-related genes, and 722 genes encoding carbohydrate-active enzymes (CAZymes). Integrated analyses of the secretome, PHI, and DFVF databases revealed six secreted carbohydrate-active enzymes implicated in plant pathogenicity, including three glycoside hydrolases, two pectinate lyases, and one cutinase, potentially playing important roles in pathogenicity. A total of 77 secondary metabolite gene clusters were predicted. Comparative genomic analysis between N. musae ST1 and other Nigrospora species revealed differences in genome rearrangements in Nigrospora fungi. In conclusion, this study has clarified the whole-genome structural characteristics and evolutionary relationships of the newly reported pathogenic fungus, N. musae ST1. It provides a theoretical foundation for future investigations into the pathogenic mechanisms of N. musae ST1 infection in I. polycarpa, as well as potential targets for disease control.