Anti-oxidative enzyme activity and virus acquisition in Bemisia tabaci (Hemiptera: Aleyrodidae) under stress conditions

In most eukaryotic systems, antioxidants provide protection when cells are exposed to stressful environmental conditions. Antioxidants, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase, function in a stepwise series with SOD initially preventing oxidative damage by converting O2– free radicals to hydrogen peroxides. GPx then reduces free hydrogen peroxide to water, preventing damage to the proteins, DNA, and lipids of the cell. We hypothesize that the activities of SOD, GPx and catalase provide mechanisms that contribute to the survival of whiteflies during times of stress. Using whiteflies fed on uninfected plants and plants infected with two begomoviruses, tomato mottle virus (ToMoV) and tomato yellow leaf curl virus (TYLCV), we quantified the catalase activity. Previously, we tested the activity of SOD and GPx in uninfected and viruliferous whiteflies. We used commercially available spectrophotometric assays to establish a correlation between SOD, GPx and catalase activity in whiteflies under heat stress fed on begomovirus–infected plants versus those fed on healthy tomato plants.