Abstract

Gray mold disease caused by Botrytis cinerea is a major challenge to postharvest fruit quality. Volatile organic compounds (VOCs) offer an effective and eco-friendly biocontrol strategy. This study investigates the antifungal efficacy and mechanism of 2-nonanone (2-NN), a Generally Recognized as Safe (GRAS) ketone, against B. cinerea and its potential for fruit preservation. Complete inhibition of B. cinerea colony growth was achieved by 2-NN at 0.5 mL L −1 in vitro , and gray mold development in inoculated kiwifruit and cherry tomato fruit was effectively suppressed at 12 mL L −1 . Under simulated storage conditions, 2-NN significantly mitigated the natural incidence and preserved cherry tomato fruit quality by slowing senescence (reducing respiration rate and ethylene release) and enhancing the antioxidant defense system. Mechanistically, 2-NN induced severe oxidative stress in B. cinerea by causing rapid cell membrane disruption and simultaneously impairing key fungal antioxidant enzyme activities. Transcriptome analysis revealed that 2-NN exerts its antifungal effect by broadly downregulating genes associated with pathogenicity and disrupting critical metabolic pathways, including thiamine metabolism, pentose and glucuronate interconversions, and arginine/proline metabolism. The results collectively indicate that 2-NN, due to its dual action in directly controlling the pathogen and preserving host quality, holds considerable promise as a sustainable and eco-friendly antifungal agent for the management of postharvest gray mold.