Phytotoxic peptides released by the phytopathogenic fungus Botrytis cinerea as a potential novel mechanism of fungal infection

Botrytis cinerea , the causal agent of grey mould and noble rot, is a phytopathogenic fungus of scientific and economic relevance due to its effects on agriculture. This fungus employs various molecular tools, such as the secretion of lytic enzymes and secondary metabolites, to infect and colonize plant tissues. Pathogenicity and virulence factors are identified, highlighting their roles in the infectious cycle. Here, we report on a potentially novel infection mechanism of B. cinerea based on the production of bioactive peptides. These peptides were isolated from cultures with glucose (constitutive stage) and tomato extract (virulence inducer) and showed significant toxicity when assayed in plant tissue, suggesting a crucial function in the fungus-plant interaction. Molecular analysis methods were employed to determine the expression of genes involved in peptide production, highlighting the potential for de novo peptide synthesis and degradation of parental proteins. The results indicate that B. cinerea has significant biotechnological potential, as it can generate peptides of interest for both industrial and pharmaceutical applications, which might also play an important role in infection. This work is pioneering in describing the peptidome of a phytopathogenic fungus and suggests new strategies for controlling microbial infections. • B. cinerea forms bioactive peptides via proteolysis/de novo synthesis for virulence. • Phytotoxic and bacteriostatic peptides have been identified by LC–MS/MS. • RT-qPCR confirm the expression of these genes under infection conditions. • Transcriptomic data shows that Bcap8 and NRPS participates in their biosynthesis. • These results reveal new fungal virulence mechanisms and new antimicrobial targets.