Document Type : Research Article
Authors
1
Department of Plant Science, Faculty of Science, Shahrekord University, Iran
2
Department of Plant Biology, Faculty of Basic Sciences, Shahrekord University, Shahrekord, Iran
3
Department of Genetics, Faculty of Basic Sciences, Shahrekord University, Shahrekord, Iran
4
Department of Plant Science, Agriculture Building, University of Manitoba, Winnipeg, Canada
Abstract
Secondary metabolites of fungi, particularly non-ribosomal peptides (NRPs), are key virulence and ecological adaptation factors. These compounds are primarily synthesized by giant non-ribosomal peptide synthetases (NRPSs), which can incorporate a wide range of amino acids, including non-proteinogenic and D-amino acids, to produce molecules with potent biological activities. In this study, the genome of the phytopathogenic fungus Colletotrichum lindemuthianum, the causal agent of common bean anthracnose (Phaseolus vulgaris), was analyzed for the first time for NRPS biosynthetic gene clusters. Using a combination of genomic analyses, 14 NRPS genes were identified, comprising 6 single-module and 8 multi-module genes. Domain analysis revealed that four multi-module NRPSs unusually terminate with a PP domain instead of the typical condensation domain, while one terminates with an epimerization domain, suggesting alternative peptide release mechanisms. Phylogenetic analysis of adenylation domains formed 14 distinct clades, several of which (NRPS1, NRPS4 and NRPS8) displayed high homology with known NRPSs involved in apicidin and siderophore production. These findings highlight the considerable diversity of secondary metabolite pathways in C. lindemuthianum, which likely contributes to host specificity, iron acquisition, and pathogenicity. The results provide a critical foundation for future functional studies (gene knockouts, metabolomics, and virulence assays) to elucidate the precise roles of these clusters in the pathogen–host interaction and to develop novel biological control strategies for bean anthracnose.
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