Decoding virulence in Penicillium italicum: A functional link between NRPS-derived cyclic peptides and citrus infection
Penicillium italicum is a postharvest pathogen responsible for the blue mold disease in citrus fruit, particularly under cold and dry storage conditions. Although the disease poses significant economic losses in global citrus production, the molecular basis of P. italicum virulence remains largely u...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/408644 |
| Acceso en línea: | http://hdl.handle.net/10261/408644 |
| Access Level: | acceso embargado |
| Palabra clave: | Blue mold disease Postharvest pathology Secondary metabolites Fungal virulence factors HcpA gene Cyclic tetrapeptides postharvest diseases Penicillium italicum virulence |
| Sumario: | Penicillium italicum is a postharvest pathogen responsible for the blue mold disease in citrus fruit, particularly under cold and dry storage conditions. Although the disease poses significant economic losses in global citrus production, the molecular basis of P. italicum virulence remains largely unexplored. In this study, we uncover a direct link between the fungus’s secondary metabolism and its pathogenicity by integrating untargeted metabolomics, gene deletion, and functional assays. LC-HRMS analysis of extracts of infected citrus tissues revealed the active production of cyclic peptides, including fungisporin and structurally related tetrapeptides, during host colonization. These compounds are functionally characterized for the first time as secondary metabolites of P. italicum. Targeted deletion of hcpA, encoding a multimodular nonribosomal peptide synthetase (NRPS), abolished the production of these metabolites, confirming its essential role in their biosynthesis. Although the ΔhcpA mutant exhibited normal growth and sporulation, it was more susceptible to osmotic stress and caused smaller lesions on orange fruit, indicating impaired virulence. Taken together, our findings reveal that HcpA-dependent cyclic peptides function as time-regulated virulence factors and offer novel insights into the infection strategy of P. italicum. This study identifies a promising molecular target for the development of innovative approaches to postharvest disease control in citrus. |
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