The volatile organic compounds produced by plants and microorganisms have been widely used for postharvest disease control due to their high antifungal capacity. In this research, a volatile product of citrate metabolism, 2,3-butanedione, was assayed against gray mold caused by Botrytis cinerea on postharvest fruit. 2,3-Butanedione treatment exhibited a distinct inhibitory effect on colony growth, conidial germination rate and germ tube length of B. cinerea in vitro and efficiently mitigated the disease prevalence of inoculated fruit under both artificial and natural inoculation conditions. Transcriptome analysis displayed that 2,3-butanedione treatment led to down-regulated expression of genes associated with arginine biosynthesis, ribosome biogenesis and several pathogenicity-related genes, including Bcpg1–3, BcNEP1, Bcboa2 and Bmp1. Furthermore, treatment led to increased genes expression related to proteolysis, peroxisome and autophagy. Among them, the autophagy pathway was most prominent, and key genes in this pathway (BcATGs and BcVPS45) were activated by 2,3-butanedione treatment. Moreover, numerous autophagic vacuoles containing cytoplasmic components were observed in the 2,3-butanedione-treated fungal cells. These results suggest that 2,3-butanedione inhibits gray mold on postharvest fruit by not only interfering the gene expression of fungal growth and pathogenicity in B. cinerea, but also inducing autophagic activity. Collectively, these results provide a theoretical basis for elucidating the underlying antifungal mechanism of 2,3-butanedione against B. cinerea.

植物和微生物产生的挥发性有机化合物因其高抗真菌能力而被广泛用于采后病害防治。在这项研究中，柠檬酸盐代谢的挥发性产物 2,3-丁二酮对采后果实上由灰霉病菌引起的灰霉病进行了测定。2,3-丁二酮处理对B. cinerea 的菌落生长、分生孢子萌发率和胚管长度表现出明显的抑制作用在人工和自然接种条件下有效减轻接种果实的病害流行。转录组分析显示，2,3-丁二酮处理导致与精氨酸生物合成、核糖体生物发生和几种致病性相关基因（包括Bcpg1-3、BcNEP1、Bcboa2和Bmp1 ）相关的基因表达下调。此外，治疗导致与蛋白水解、过氧化物酶体和自噬相关的基因表达增加。其中以自噬途径最为突出，该途径中的关键基因（BcATGs和BcVPS45) 被 2,3-丁二酮处理激活。此外，在 2,3-丁二酮处理的真菌细胞中观察到许多含有细胞质成分的自噬泡。这些结果表明，2,3-丁二酮不仅通过干扰灰霉病菌中真菌生长和致病性的基因表达，而且通过诱导自噬活性来抑制采后果实上的灰霉病。总的来说，这些结果为阐明 2,3-丁二酮对灰霉病菌的潜在抗真菌机制提供了理论基础。