抗性和敏感小菜蛾谷胱甘肽-S-转移酶和谷胱甘肽的比较

Comparison of glutathione-S-transferase and glutathione in resistant and susceptible diamondback moth

研究了抗性和敏感小菜蛾谷胱甘肽 - S-转移酶 ( GSTs)在不同发育期的变化及有机磷类杀虫剂对虫体谷胱甘肽 ( GSH)质量摩尔浓度的影响 .结果表明 :抗性和敏感小菜蛾 GSTs比活力在各发育期中变化不大 ,但虫体 GSTs总活力随虫体生长发育而显著增加 ,在 4龄和蛹期达到最大值 .抗性小菜蛾 GSTs活力明显高于敏感小菜蛾 .甲胺磷和水胺硫磷对敏感小菜蛾幼虫 GSH影响不明显 ,但可导致抗性小菜蛾 GSH质量摩尔浓度的显著降低 .因此可以认为 ,GSTs活力增高和 GSH的结合作用应是小菜蛾对有机磷类杀虫剂抗性的重要机制 .

Changes of glutathione S transferase (GSTs) at various developmental stages of resistant and susceptible diamondback moth, Plutella xylostella (L.), were investigated, and the effect of organophosphorous insecticides on molality of the glutathione (GSH) was detected. There were no significant differences in the specific activities of GSTs among the various developmental stages of the diamondback moth, but the total activity of GSTs per insect increased sharply with the growth of the insect, and reached the peak at the fourth instar and pupal stage. The activity of GSTs in resistant diamondback moth was obviously higher than that in susceptible one. Methamidophos and isocarbophos had no significant effect on GSH in the larva of susceptible diamondback moth but caused sharp decrease in molality of GSH in resistant diamondback moth. Therefore, it was suggested that the enhancement of activity of GSTs and the conjugation of GSH should be important mechanisms of the organophosphorous resistance in diamondback moth.