Berberine Synergistically Enhances Iprodione’s Antifungal Activity Against Colletotrichum gloeosporioides

Abstract

Postharvest diseases, particularly anthracnose caused by Colletotrichum gloeosporioides, pose significant challenges to global fruit markets by reducing quality and marketability. Although traditional fungicides like Iprodione are commonly used for disease control, their effectiveness is increasingly limited by environmental concerns and the emergence of resistant fungal strains. This study investigated the potential of berberine, a natural alkaloid, to enhance the antifungal efficacy of Iprodione. In vitro assays showed that berberine significantly improved Iprodione’s inhibitory effects on fungal growth and conidia germ tube elongation. In vivo tests on apple fruit further validated these findings, showing significant reductions in lesion when berberine and Iprodione were applied together compared to either treatment alone. Western blot analysis revealed that the combined treatment significantly decreased protein phosphorylation in C. gloeosporioides, indicating enhanced dephosphorylation effects. Transcriptomic analysis revealed that berberine downregulates key detoxification and fungicide-resistance genes, such as cytochrome P450s, amidohydrolases, DyP-type peroxidase and membrane transporters, disrupting detoxification pathways and increasing Iprodione’s toxicity. Gene knockout studies indicated that ΔCgADH1 and ΔCgDyPOD1 mutants exhibited increased sensitivity to Iprodione, highlighting their roles in resistance mechanisms. These findings suggest that berberine can synergistically enhance Iprodione’s antifungal activity, providing a promising, eco-friendly strategy for controlling postharvest anthracnose while potentially reducing fungicide usage in the fruit industry.