Effect of salicylic acid treatment on antioxidant capacity and endogenous hormones in winter jujube during shelf life

• Salicylic acid treatment better maintains the quality of winter jujube during storage. • Salicylic acid treatment promoted antioxidant enzyme activity. • Salicylic acid treatment stimulated the ascorbic acid-glutathione cycle. • Salicylic acid treatment regulates endogenous hormones to delay fruit senescence. This study investigated the effects of exogenous salicylic acid (SA) treatment (0, control; 3 mmol L -1 ) on the antioxidant and hormone levels of winter jujube during shelf life (20 d) at 4 °C. The results showed that 3 mmol L -1 SA treatment preferably maintained firmness, color, titratable acidity, and total soluble solids, and effectively reduced the respiratory intensity and TSS/TA value (13.08%) of the fruit. Compared with the control group, the SA group had a higher content of sucrose (14.03%) and malic acid (29.13%). Meanwhile, SA reduced the accumulation of H 2 O 2 (27.73%) and O 2 ·- (45.44%) by enhancing the activity of antioxidant enzymes (superoxide dismutase, peroxidase, catalase, ascorbate peroxidase) and the content of antioxidant substances (ascorbic acid, total phenols, total flavonoids, and glutathione) in the fruit. In addition, 3 mmol L -1 SA treatment led to higher levels of endogenous abscisic acid (18.49%) and SA (20.47%) in fruit, and lower concentration of jasmonic acid (42.68%), but had a weak effect on indole acetic acid levels.