The effects of short-term heat stress on the activity of protective enzymes and total antioxidant capacity in Tetranychus urticae (Acari: Tetranychidae)

Abstract

Abstract Tetranychus urticae Koch is a worldwide pest mite which can cause continuous damage to multiple plants even in hot environment such as greenhouse due to its strong endurance to high temperature. In order to clarify the physiological mechanisms of T. urticae in response to short-term heat stress, four high temperatures (36, 39, 42, and 45°C), three short-term heat durations (2, 4, and 6 h) were conducted to test the effects on the protein content of T. urticae and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and total antioxidant capacity (T-AOC), respectively. The results showed that protein content, antioxidant enzymes activity, and T-AOC in T. urticae were significantly affected by both the high temperature and duration after treatment, meanwhile, they showed same trends of increased at 25–39℃, then decreased at 39–42℃ except for CAT activity. The highest values of SOD activity, POD activity and T-AOC were all obtained at 39℃-4h, and that of CAT activity was obtained at 39℃-2h. The higher levels of T-AOC serve an important signal demonstrating that T. urticae has other antioxidant mechanisms except for antioxidant enzymes. Those results suggested that heat stress induces oxidative stress, and antioxidant enzymes played important role in reducing oxidative damage in T. urticae. which provided a basis for further research on the molecular mechanisms of thermostability and ecological adaptability of T. urticae.