Allicin derivative (DETS) treatment reduced post-harvest decay in strawberries by inhibiting Botrytis cinerea viability and increasing antioxidant capacity

Abstract

Botrytis cinerea is a fungal pathogen causing severe post-harvest decay in strawberries. The diethylthiosulfinate showed greater stability and antibacterial activity than allicin. This research investigated the inhibiting efficacy of diethylthiosulfinate on Botrytis cinerea in vitro and in vivo, and the resistance mechanisms for fungal control of strawberries were explored. The minimum inhibitory concentration of diethylthiosulfinate against Botrytis cinerea is 0.2 g L⁻¹ in vitro. Diethylthiosulfinate impeded the formation of spores and mycelium with overproduction of reactive oxygen species, which disrupted the structural and functional identity of the cell plasma membrane in Botrytis cinerea, leading leaking of cellular contents. Moreover, the application of diethylthiosulfinate significantly reduced the incidence and disease severity of gray mold on strawberry fruits inoculated with Botrytis cinerea. On the 4th day following inoculation, the disease index and disease rate of the 0.2 g L⁻¹ diethylthiosulfinate group were 25% and 8% lower than the control group, respectively. Furthermore, diethylthiosulfinate treatment has the potential to regulate reactive oxygen species metabolism of strawberry fruits, enhancing their resistance to Botrytis cinerea. This may be achieved by maintaining the contents of ascorbic acid, total phenolics and total flavonoids, and by boosting the activities of superoxide dismutase, catalase, ascorbate peroxidase and phenylalanine ammonia-lyase. Consequently, diethylthiosulfinate suppresses the growth of Botrytis cinerea, increases the tolerance of strawberries to disease, and is a potentially agent in the development of effective control and preservation measures to delay decay.