biostudies-literatureHong SNational Natural Science Foundation of China1-11https://www.ebi.ac.uk/biostudies/studies/S-EPMC9751272biostudies-literatureUnknown17(1)Insects can assemble defensive microbiomes on their body surfaces to defend against fungal parasitic infections. The strategies employed by fungal pathogens to combat host cuticular microbiotas remains unclear. Here, we report the identification and functional characterization of the defensin-like antimicrobial gene BbAMP1 encoded by the entomopathogenic fungus Beauveria bassiana. The mature peptide of BbAMP1 can coat fungal spores and can be secreted by the fungus to target and damage Gram-positive bacterial cells. Significant differences in insect survival were observed between the wild-type and BbAMP1 mutant strains during topical infection but not during injection assays that bypassed insect cuticles. Thus, BbAMP1 deletion considerably reduced fungal virulence while gene overexpressionThe ISME journalSuppression of the insect cuticular microbiomes by a fungal defensin to facilitate parasite infection.PMC975127232021001Wang CChen HSun YHong SfalseSuppression of the insect cuticular microbiomes by a fungal defensin to facilitate parasite infection.Insects can assemble defensive microbiomes on their body surfaces to defend against fungal parasitic infections. The strategies employed by fungal pathogens to combat host cuticular microbiotas remains unclear. Here, we report the identification and functional characterization of the defensin-like antimicrobial gene BbAMP1 encoded by the entomopathogenic fungus Beauveria bassiana. The mature peptide of BbAMP1 can coat fungal spores and can be secreted by the fungus to target and damage Gram-positive bacterial cells. Significant differences in insect survival were observed between the wild-type and BbAMP1 mutant strains during topical infection but not during injection assays that bypassed insect cuticles. Thus, BbAMP1 deletion considerably reduced fungal virulence while gene overexpression2023-01-01T00:00:00Z2023 Jan2025-04-26T07:46:29.184Z2025-04-06T12:29:21.286ZS-EPMC97512723612743210.1038/s41396-022-01323-7