两种杀虫剂亚致死浓度对大豆蚜三种解毒酶和蛋白含量的影响

Effects of Sublethal Concentration of Two Insecticides on Three Detoxification Enzymes and Protein Content of Aphis glycines

为明确吡虫啉和印楝素对大豆蚜的亚致死效应,用带虫浸叶法处理大豆蚜成蚜,计算杀虫剂的毒力回归方程及LC10、LC20和LC40浓度,并测定不同亚致死浓度处理不同时间3种主要解毒酶的活性及蛋白含量。结果表明:吡虫啉的毒力方程为y=1.1784x+10.7023,印楝素的毒力方程为y=1.6323x+10.8815。吡虫啉处理后,对多功能氧化酶(MFO)活性先抑制、后诱导,其中LC20处理的诱导作用最强;对羧酸酯酶(CES)主要为抑制作用;LC10处理对谷胱甘肽S-转移酶(GST)活性诱导作用最强。印楝素对3种酶主要为抑制作用,仅在24 h后对MFO和CES表现为诱导作用。吡虫啉处理1 h后,大豆蚜可溶性蛋白含量显著高于CK。印楝素处理的蛋白含量在1 h时均显著高于CK,LC20处理的蛋白含量最高,表现为随药剂浓度升高而先升后降。结果表明,大豆蚜代谢吡虫啉过程中,MFO和GST可能发挥主要作用,CES作用不明显;大豆蚜代谢印楝素时,MFO和CES可能对低浓度(LC10)处理有一定作用,GST的作用不大。2种药剂处理的大豆蚜可溶性蛋白含量均在处理1 h时较高。

In order to make clear the sublethal effect of imidacloprid and azadirachtin on soybean aphids,the adult soybean aphids(Aphis glycines),were treated by leaf dipping method.The toxicity regression equations of the two insecticides and the concentration of LC10,LC20and LC40 were calculated.Soybean aphids were treated with the sublethal concentrations for 1,12,24 and 48 h.The activity of three main detoxifying enzymes and the soluble protein content were measured.The toxicity equation of imidacloprid was y=1.1784x+10.7023,and the equation of azadirachtin was y=1.6323x+10.8815.After treated by imidacloprid,the activity of MFO was firstly inhibited and then induced,among which LC20 treatment had the strongest induction effect.Imidacloprid was mainly inhibitory to CES.The induction effect of imidacloprid LC10 treatment on GST activity was the strongest.Azadirachtin mainly inhibited the activity of the three enzymes,and only induced the activity of MFO and CES at 24 h.After treated with imidacloprid for 1 h,the soluble protein content of soybean aphid was significantly higher than that of CK.After treated by azadirachtin,the protein content was significantly higher than that of CK at 1 h,and the protein content of LC20 treatment was still significantly higher than that of CK at 12 h,with the concentration effect of increasing protein content first and then decreasing with the increasing of insecticide concentration.The results indicated that MFO and GST played key roles during the metabolism of imidacloprid by soybean aphid,but CES had no significant effect.In azadirachtin metabolism,MFO and CES only played a certain role in low concentration(LC10)treatment,GST was weak at all treatments.The soluble protein content of soybean aphid treated by the two insecticides was higher at 1 h.