不同地理种群甘薯茎线虫乙酰胆碱酯酶对抑制剂的敏感性

Susceptibility of acetylcholinesterase of different populations of Ditylenchus destructor to inhibitors

用改进的Ellman方法测定了河北省昌黎、涿州、卢龙和抚宁四个不同地理种群甘薯茎线虫Ditylenchus destructor的乙酰胆碱酯酶（AChE）的生化特性及其对抑制剂涕灭威和毒扁豆碱的敏感性差异。结果表明：甘薯茎线虫AChE至少存在两种类型，一种类型对毒扁豆碱的IC50值小于10^-6mol／L，另一种类型大于10^-4mol／L。当抑制剂毒扁豆碱浓度为10^-6～10^10mol／L、涕灭威浓度为10^-5～10^10mol／L时，甘薯茎线虫昌黎种群AChE的敏感性抑制率明显高于涿州、抚宁、卢龙三地的甘薯茎线虫种群AChE的抑制率。各地种群AChE对抑制剂敏感性差异是由于甘薯茎线虫AChE的多态性和各分子型综合性改变的结果。

The acetylcholinesterase （ACHE） properties of four populations of Ditylenchus destructor and susceptibilities to inhibitors were investigated. AChE was extracted in a direct method and ultracentrifugetion in sucrose gradients. AChE activities were determined by the amended spectrophotometric method of Ellman. Effect of inhibitors on AChE hydrolysis was analyzed. The results showed that there are two major class AChEs in acetylcholine hydrolysis at least. One class of AChE is highly sensitive to eserine （IC50 〈 10^-6 mol/L） and other class is less sensitive to eserine （IC50 〉 106-4 mol/L）. Inhibition of AChE activity of Changli population was higher than that of Zhuozhou, Lulong and Funing populations at the concentration 10^-6-10^-10 mol/L of eserine and at 10^-5-10^-10 mol/L of aldicarb. This susceptibilities difference of AChE of different populations to inhibitors may be due to the polymorphism of AChE and the multiple changes of different molecular polymorphism.