Effects of Drought Stress on Accumulation of Proline and Antioxidant Enzymes in the Different Varieties of Yardlong Beans

The effect of drought stress on biochemical activities included changes in the concentrations of proline and the activity of antioxidant. This study aimed to determine the effect of drought stress on proline activity and antioxidant enzymes catalase (CAT), peroxidase (POX), and superoxide dismutase (SOD) on varieties of yardlong beans. The first factor was the variety of yardlong beans, including Brawijaya Ungu-1 (BU-1), Brawijaya Ungu-2 (BU-2), Brawijaya Ungu-3 (BU-3), Brawijaya Ungu-4 (BU-4), Brawijaya Ungu-5 (BU-5), Brawijaya Ungu-6 (BU-6), Brawijaya-4 (Br-4), and Bagong-2 (Bg-2). The second factor was drought stress level consisting of 50% and 100% field capacity (FC) as a control. The results showed that the concentrations of proline and activity of antioxidant enzymes increased drought stress. BU-4 variety experienced the highest enhancement of proline, and BU-2 variety experienced the highest enhancement of catalase and superoxide dismutase while Br-4 variety experienced the highest enhancement of peroxidase. So BU-4, BU-2, and Br-4 varieties were said to be more tolerant to drought stress, based on proline and antioxidant enzymes accumulation.