VdNPS, a nonribosomal peptide synthetase, is involved in regulating virulence in verticillium dahliae

Abstract

Nonribosomal peptide synthetases (NPS) are known for the biosynthesis of antibiotics, toxins, and siderophore production. They are also a virulence determinant in different phytopathogens. However, until now, the functional characterization of NPS in Verticillium dahliae has not been reported. Deletion of the NPS gene in V. dahliae led to the decrease of conidia, microsclerotia, and pathogenicity. DVdNPS strains were tolerant to H2O2, and the genes involved in H2O2 detoxification, iron/copper transport, and cytoskeleton were differentially expressed in DVdNPS. Interestingly, DVdNPS strains exhibited hypersensitivity to salicylic acid (SA), and the genes involved in SA hydroxylation were up-regulated in DVdNPS compared with wild-type V. dahliae under SA stress. Additionally, during infection, DVdNPS induced more pathogenesis-related gene expression, higher reactive oxygen species production, and stronger SA-mediated signaling transduction in host to overcome pathogen. Uncovering the function of VdNPS in pathogenicity could provide a reliable theoretical basis for the development of cultivars with durable resistance against V. dahliae-associated diseases.