Fig. 3
Effect of the heat shock on superoxide (O2·−), hydrogen peroxide (H2O2) content and antioxidant ability in four water spinach cultivars cultured at 25 °C and 42 °C for 15 days, respectively. a-d The generation of O2·− in water spinach leaves measured by nitro blue tetrazolium (NBT) reduction method in four cultivars, respectively. e-h The H2O2 content of water spinach measured by 3, 3′-diaminobenzidine (DAB) method in four cultivars, respectively. i The polyphenol content of leaves in four water spinach cultivars cultured at 25 °C and 42 °C, respectively. j The total antioxidant capacity measured by 2, 2-azobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) in four water spinach cultivars cultured at 25 °C and 42 °C, respectively. The statistical analyses were conducted in the same variety under different temperature conditions and the significant one was labelled with asterisks (*)