Interaction effects of salicylic acid and methyl jasmonate on total antioxidant content, catalase and peroxidase enzymes activity in “Sabrosa” strawberry fruit during storage

Strawberry is very susceptible to postharvest losses and more than 50% of harvested fruit is lost in Iran. For many years synthetic chemicals have been used to increase fruit storage life but, because of food safety issues, the use of chemicals in postharvest technology is highly restricted. Extending the storage life of harvested products by enhancing natural resistance and antioxidative systems of the crop is an alternative strategy to chemicals in postharvest technology. Effect of postharvest treatment with salicylic acid (at 0, 1 and 2 mmol/L) and methyl jasmonate (at 0, 8 and 16 μmol/L) on antioxidant content and some defense enzymes activity of Sabrosa strawberry fruit during storage at 1 ± 0.5 °C with 90-95% RH. for 14 days followed by 24 h at 20 °C was studied. Both phytochemicals, separately or in combination, enhanced fruit total antioxidant content, catalase and peroxidase enzymes activity. Catalase enzyme activity was decreased after treatment with methyl jasmonate but the effect of methyl jasmonate in decreasing catalase activity was prevented by salicylic acid. It seems that in order to stablish a strong resistance network and extend fruit postharvest life a positive crosstalk between the two phytochemicals is necessary in “Sabrosa” strawberry fruit.