在27~29℃温度下,用1.5 mL/L的正己烷蒸气处理菜蛾盘绒茧蜂滞育蛹10~15 min后可以解除其滞育。为探讨解除滞育的机制,测定了正己烷处理后菜蛾盘绒茧蜂滞育预蛹体内的过氧化氢含量(H2O2)和3种抗氧化酶(SOD、POD和CAT)活性。结果表明正己烷处理后,滞育预蛹体内H2O2含量、SOD和POD活性均迅速上升,CAT活性则下降。就5个取样点的平均值而言,H2O2含量和SOD活性显著高于非滞育预蛹和未经处理的滞育预蛹,POD活性低于非滞育预蛹而高于未经处理的滞育预蛹,CAT活性则低于未经处理的滞育预蛹而高于非滞育预蛹。3种抗氧化酶活性的变化与体内H2O2含量的平衡有关,而H2O2含量的变化可能与体内激素水平的调节有关。
Exposure of the diapause individuals to 27-29 ℃ and 1.5 mL/L n-hexane for 10-15 min can effectively terminate diapause in Cotesia vestalis (Haliday). To unravel the mechanism of diapause termination, hydrogen peroxide content and activities of three antioxidant enzymes, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), were quantified in diapause prepupae of C. vestalis. Results showed that, in the n-hexane-exposed diapause individuals, hydrogen peroxide content and activities of SOD and POD increased sharply, while activity of CAT declined. On average, hydrogen peroxide content and SOD activity were significantly higher in the exposed diapause prepupae than those in unexposed both diapause and non-diapause prepupae;POD activity was significantly lower than that in non-diapause prepupae but significantly higher than that in unexposed diapause prepupae; CAT activity was significantly lower than that in the unexposed diapause prepupae but significantly higher than that in non-diapause prepupae. Hydrogen peroxide content depends on activities of the three antioxidant enzymes, while the former can regulate hormone level in diapause prepupae, which may be the reasons for diapause termination by n-hexane.