Antifungal mechanism and mycotoxin control of Ligusticum jeholense essential oil against Alternaria alternata in postharvest tomato

Alternaria alternata causes serious postharvest diseases in tomatoes, threatening shelf life and food safety. In this study, a natural and eco-friendly strategy was developed using Ligusticum jeholense essential oil (LEO), extracted via optimized enzymatic–deep eutectic solvent microwave-assisted method (EDP–MAHD), which achieved a 3.38-fold higher yield than conventional extraction. GC–MS analysis confirmed consistent chemical composition across production batches. In vitro , LEO exhibited potent antifungal activity against A. alternata (IC₅₀, 0.0718 μL/mL), while in vivo experiments on tomato fruit showed it significantly inhibited lesion expansion and suppressed the accumulation of mycotoxins, alternariol (AOH) and tenuazonic acid (TeA). SEM, TEM, proteomic, and physiological analyses revealed that LEO disrupted membrane integrity, interfered with energy metabolism, and induced oxidative stress, suggesting multi-target antifungal mechanisms. Acute toxicity in mice confirmed its safety. These findings support the application of LEO as a promising natural preservative for postharvest disease and toxin control in tomatoes.