3-Methyl-1-butanol inhibited gray mold of red grape by damaging cell membrane integrity and the antioxidant capacity of Botrytis cinerea under oxidative stress

Gray mold, caused by Botrytis cinerea , is a serious postharvest disease, causing huge economic losses of crops. In this study, we explored the resistance of 3-Methyl-1-butanol, a volatile substance produced by yeast, on B. cinerea . The results indicated that 3-Methyl-1-butanol had an inhibitory effect on the growth and development of B. cinerea , both in vitro and in vivo . In vitro , 2 μL mL −1 3-Methyl-1-butanol treatment decreased the cell survival rate of B. cinerea and inhibited spore germination. Scanning and transmission electron microscopy analysis revealed that 3-Methyl-1-butanol disrupted the microstructure of the mycelium, compromised membrane integrity, and triggered programmed cell death. Furthermore, a reduced function of B. cinerea antioxidant enzymes was observed after treatment with 3-Methyl-1-butanol. In addition, genes related to spore germination, virulence, and ergosterol synthesis were downregulated. In vivo , 3-Methyl-1-butanol treatment inhibited the growth of B. cinerea , as revealed by a decreased lesion diameter, on red grapes. In conclusion, 3-Methyl-1-butanol could modulate the growth and development of B. cinerea by diminishing cell viability and antioxidant capacity, compromising cellular membrane integrity, and impeding conidia germination. Our study highlights the potential role of 3-Methyl-1-butanol in controlling postharvest botrytis and provides a theoretical basis for its antifungal activity against B. cinerea . • 3-Methyl-1-butanol inhibited spore germination of Botrytis cinerea. • 3-Methyl-1-butanol decreased the cell viability of Botrytis cinerea. • 3-Methyl-1-butanol decreased antioxidant enzyme activity of Botrytis cinerea. • 3-Methyl-1-butanol damaged the membrane integrity of Botrytis cinerea. • 3-Methyl-1-butanol could effectively regulate Botrytis cinerea in vitro and in vivo.