Efficacy of Ginkgo biloba extract in controlling patulin production by Penicillium expansum in sweet cherries.

Abstract

Fungal toxin contamination presents significant hazards to agroecosystems and food safety. Penicillium expansum (P. expansum) emerges as a primary threat, damaging sweet cherries through spoilage and generating the hazardous mycotoxin patulin (PAT). Although Ginkgo biloba extract (GBE) is known for its antioxidant and antibacterial properties, its antifungal mechanisms against P. expansum remain unclear. In this study, we investigated the antifungal activity of GBE harvested at different phenological periods against postharvest P. expansum in sweet cherries and elucidated its underlying mechanisms. Non-targeted metabolomics identified flavonoids and ginkgolides may be as key bioactive compounds contributing to the differential antimicrobial potency of GBE. Notably, GBE-G3 (0.24 % GBE from green leaves) exhibited the strongest inhibitory effects, reducing spore germination by 81 % and mycelial growth by 91.43 %, accompanied by morphological alterations such as spore shrinkage and hyphal collapse. Sweet cherry experiments showed that 0.2 4 % GBE treatment reduced morbidity to 27.78 % and PAT content to 0.08 μg/g. Transcriptomic analysis further demonstrated that GBE-G3 disrupted cellular integrity by up-regulating organelle-related genes and down-regulating cell membrane/wall biosynthesis genes, which was validated by extracellular leakage of nucleic acids (1.61-fold), proteins (1.93-fold), and alkaline phosphatase (4.96-fold). Additionally, GBE-G3 suppressed the expression of PAT biosynthetic enzymes (PePatB, PePatH, and PePatK), transcriptional regulators (PePatL), and virulence-associated transporters, indicating a dual inhibitory effect on both fungal growth and toxin production. Finding revealed that GBE exerted antifungal activity through membrane disruption and transcriptional modulation of PAT-related pathways, providing a novel strategy for controlling P. expansum contamination in agro-food systems.