Induction of the activities of antioxidative enzymes and the levels of malondialdehyde in cucumber seedlings as a consequence of Bemisia tabaci (Hemiptera: Aleyrodidae) infestation

The activities of antioxidative enzymes and the concentration of malondialdehyde were assayed in cucumber leaves (Cucumis sativus L.) 0, 6, 12, 24, 48, 72, and 96 h after the cucumber seedlings were infested by Bemisia tabaci (Gennadius). The results indicated that the activities of antioxidative enzymes were increased after herbivore infestation, including superoxide dismutase (SOD), and peroxidase (POD), and the levels of malondialdehyde (MDA), which is a product of membrane lipid peroxidation in the leaves. The enzymes and MDA showed peaks of different activity levels at 24 and 48 h after the infestation. SOD activity reached the highest peak, 10.4% higher than control, at 24 h, POD activity reached the highest peak, 213.2% higher than control, at 6 h, catalase (CAT) activity was not statistically significant compared with the control, and MDA content reached the highest peak, 59.9% higher than control, at 48 h. The results suggested that the enhanced activities of antioxidative enzymes and MDA content may contribute to bioprotection of cucumber plants against B. tabaci infestation. Handling editor: Henryk Czosnek