Mechanism of antimicrobial peptide AMP-17 for inhibition of Aspergillus flavus

Abstract

Aspergillus flavus is a pathogenic fungus with a broad host range, and its secondary metabolite, aflatoxin, recognized as the world’s first naturally occurring carcinogen. Nonetheless, the current control measures for A. flavus are inadequate, thus, it is imperative to seek alternative control methods for this species. In the present study, we identified an antimicrobial peptide AMP-17, which was found to effectively inhibit the conidial germination, growth, conidiation, and aflatoxin production of A. flavus. Additionally, our investigation revealed that the inhibition of A. flavus by AMP-17 is primarily attributed to increase cell membrane permeability, modify cell surface morphology, and compromise cellular integrity, as observed through flow cytometry and scanning electron microscopy. Transcriptome analysis indicated significant transcriptional changes in several genes associated with cell wall, cell membrane, cell cycle, detoxification, and aflatoxin biosynthesis in response to AMP-17 treatment, suggesting disruption of these cellular processes and pathways in A. flavus. Furthermore, AMP-17 exhibited a broad-spectrum antifungal activity against Aspergillus spp. These findings provide a strong theoretical basis for the potential use of AMP-17 as an effective antifungal agent against A. flavus.