高温与饥饿胁迫对十斑大瓢虫生长及抗氧化酶的影响OA

To clarify the effects of high-temperature and starvation stress on the growth,development,and antioxidant enzyme activities of the aphid predator Megalocaria dilatata,heat stress treatments(32℃,36℃,40℃)and a 24 h starvation treatment were applied to determine heat knockdown time and survival rate.In addition,relative reactive oxygen species(ROS)levels and the activities of superoxide dismutase(SOD),catalase(CAT),and total antioxidant capacity(TAC)were determined under these stress conditions.Results showed that increasing temperature significantly prolonged heat knockdown time.Larvae of different instars exhibited varying tolerance to stress,and a significant interaction effect between starvation stress and high-temperature stress on larval survival rate was observed.Both high-temperature and starvation stress significantly induced the upregulation of ROS level.High-temperature stress significantly upregulated the activities of CAT and TAC whereas starvation stress significantly enhanced the activities of SOD and CAT and markedly increased TAC levels.These results contribute to a better understanding of the mechanisms underlying stress tolerance in M.dilatata under adverse environmental conditions.