Postharvest BTH treatment induced disease resistance and enhanced reactive oxygen species metabolism in muskmelon (Cucumis melo L.) fruit

Benzo (1, 2, 3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) is a novel synthetic elicitor capable of inducing disease resistance in many plants. Fruits were dipped in BTH at 100?mg/L for 10?min, and then stored at room temperature (22?±?2?°C, relative humidity 55–60?%). The results showed that BTH significantly (P?<?0.05) reduced the lesion area of fruits inoculated with Trichothecium roseum and the natural disease incidence of fruits during storage at room temperature. The treatment effectively maintained cell membrane integrity and decreased the production of lipid peroxidation and malondialdehyde. BTH treatment markedly enhanced the accumulation of hydrogen peroxide, (H₂O₂) while decreased the rate of superoxide anion (O ₂ ^·? ) production. Furthermore, BTH observably increased the activities of NADPH oxidase (NOX, EC1.6.3.1), superoxide dismutase (SOD, EC1.15.1.1), peroxidase (POD, EC1.11.1.7), ascorbate peroxidase (APX, EC1.11.1.11), and glutathione reductase (GR, EC1.6.4.2), while inhibited the catalase (CAT, EC1.11.1.6) activity. These results indicated that BTH treatment increased the disease resistance of muskmelon fruits by enhancing their antioxidant system activity after harvest, and suggested that postharvest treatment with BTH could be promising in reducing decay and reducing or/and substituting chemical fungicides to control postharvest diseases in fruits.