Effects of exogenous melatonin and abscisic acid on the antioxidant enzyme activities and photosynthetic pigment in 'Summer Black' grape under drought stress

In this study, 'Summer Black' grape seedlings were used as the experimental materials, to be applied with 100 mu mol/L melatonin (MT) and 50 mu mol/L abscisic acid (ABA) solutions to investigate the effects on antioxidant enzyme activities and photosynthetic pigment under drought stress. The results showed that the increase of chlorophyll content in grape leaves due to drought was reduced by the function of MT and ABA, while the content of carotenoid showed the opposite trend. The antioxidant capacity was measured with SOD, POD and CAT, and showed that MT, ABA treatment significantly increased the activity of SOD, but reduced activity of POD and CAT in the leaves. ABA had the greater effect, but MT seems impaired the influence of ABA. The results provided a theoretical basis for improving the yield and quality of grape.