| 摘要: |
| 【目的】探讨吡虫啉亚致死浓度对苹果蠹蛾体内解毒酶的影响，为深入研究苹果蠹蛾的抗药性机制及吡虫啉的合理使用提供理论依据。【方法】采用胃毒法测定吡虫啉对苹果蠹蛾敏感种群3龄幼虫的毒力，通过毒力回归方程计算苹果蠹蛾死亡率为10%和20%时吡虫啉的亚致死质量浓度LC10和LC20。用LC10和LC20质量浓度吡虫啉处理苹果蠹蛾，以丙酮水作对照，分析其体内多功能氧化酶(MFOs)、谷胱甘肽S 转移酶(GSTs)和羧酸酯酶(CarEs)的比活力及其米氏常数(Km)和最大反应速率(Vmax)的变化。【结果】与对照相比，LC10和LC20质量浓度吡虫啉处理后苹果蠹蛾CarEs比活力在48 h以前均高于对照，48 h时LC10处理低于对照，LC10和LC20处理CarEs比活力分别在12和36 h达到最大值。GSTs比活力LC20处理6～60 h均高于对照，36 h时达到最大；LC10处理除在6，12和60 h低于对照外，其他时间点均高于对照，48 h时达到最大。MFOs比活力LC10和LC20处理在12，24和36 h高于对照，而48 h时LC20处理低于对照，LC10处理与对照基本相同。CarEs和MFOs的Km值在各时间点均高于对照，Vmax均低于对照；GSTs的Km均低于对照，Vmax均高与对照。【结论】CarEs、MFOs和GSTs在苹果蠹蛾对吡虫啉的解毒代谢中均起作用，其中GSTs起主导作用。 |
| 关键词: 苹果蠹蛾 吡虫啉 亚致死浓度 解毒酶 酶动力学常数 |
| DOI： |
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| 基金项目:国家自然科学基金项目(31270691,31170609) |
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| Effect of sublethal concentrations of imidacloprid on activities of detoxifying enzymes in Cydia pomonella |
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SHANG Suqin,LIU Yonghua,LIU Long,et al
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| Abstract: |
| 【Objective】This paper discussed the effect of sublethal concentrations of imidacloprid on activities of detoxifying enzymes in Cydia pomonella to provide theoretical basis for further study of resistance mechanism of Cydia pomonella and rational use of imidacloprid.【Method】Virulence of imidacloprid against sensitive generation of third instar larvae of Cydia pomonella was tested by stomach toxicity method.Sublethal concentrations of imidacloprid at 10% and 20% mortality (LC10 and LC20) of Cydia pomonella were calculated by virulence regression equation.MFOs,GSTs and CarEs,and their Km and Vmax values were analyzed after treatment with imidacloprid at LC10 and LC20 concentrations.【Result】Compared with control,the specific activity of CarEs was higher than the control before 48 h after treatment with imidacloprid at LC10 and LC20 concentrations,and it was lower than the control at 48 h after treatment with LC10 concentration.The maximum specific activity of CarEs peaked at 12 h and 36 h after treatment with LC10 and LC20 concentrations,respectively.The specific activity of GSTs was higher than the control 6-60 h after treatment with LC20 concentration,and it was higher than the control all the time points except at 6 h,12 h and 60 h after treatment with LC10 concentration.The maximum for LC10 and LC20 concentrations were obtained at 36 h and 48 h,respectively.The specific activity of MFOs was higher than the control at 12 h,24 h and 36 h except 48 h after treatment with LC20 concentration,but it was same as the control after treatment with LC10 concentration.The Km values of CarEs and MFOs were higher than control after treatment at all time, but Vmax values were lower than control.The Km value of GSTs was lower than control,and Vmax of GSTs was higher than control.【Conclusion】CarEs,MFOs and GSTs played role in imidacloprid detoxification of Cydia pomonella,among which GSTs was the key one. |
| Key words: Cydia pomonella imidacloprid sublethal concentration detoxifying enzymes kinetic parameters of enzymology |
