德国小蠊抗性及敏感品系羧酸酯酶生化特征比较研究

Comparison of Biochemical Characterization of Carboxylesterase in Susceptible and Resistant Strains of German Cockroach, Blattella germanica

目的 研究德国小蠊敏感品系和抗性品系羧酸酯酶 (CarE)生化性质上的差异 ,旨在从生化水平上确定CarE在德国小蠊抗性中的作用 ,初步揭示德国小蠊抗性机制。方法 参照Asperen(1962 )和高希武 (1991)方法测定CarE活性。结果 德国小蠊抗性品系中的CarE活性要高于敏感品系中的CarE活性。抗性品系与敏感品系对α 乙酸萘酯 (α NA)的亲和力要大于对 β 乙酸萘酯 (β NA)的亲和力 ,而敏感品系CarE对α NA的亲和力要大于抗性品系CarE。时间进程曲线显示 ,在以α NA为底物时 ,抗性品系与敏感品系CarE时间进程曲线趋势不一致。对 9种德国小蠊野外品系CarE活性的测定结果表明 ,除 1种品系外 ,其余品系均使CarE活性提高 ,幅度在 1.2 3～ 2 .83倍之间。结论德国小蠊抗性品系和敏感品系在CarE生化特征上的差异 ,显示出德国小蠊抗性品系对几种拟除虫菊酯类杀虫剂产生的高度抗性 ,与其体内CarE活性的提高有密切关系 ,表明CarE活性的提高是北京地区野外德国小蠊品系普遍存在的一种抗性机制。

Objective To preliminarily identify biochemical mechanism of insecticide resistance by comparing the activities of CarE in susceptible and 9 field resistant populations of German cockroach, Blattella germanica in Beijing. Methods Activity of CarE was tested by methods of Asperen and GAO Xi-wu. Results The activity of carboxylesterase in resistance strains was higher than that in the susceptible strain. The affinity of CarE was much higher toward α-naphthyl acetate( α-NA) than toward β-naphthyl acetate( β-NA) in both susceptible and resistant strains, but the affinity of CarE was much higher toward α-NA in susceptible strain than that in resistance strains. Activity of CarE was increased in 8 of 9 field populations collected from Beijing, relative resistance ratio ranged from 1.23 to 2.83 fold. Conclusion The results suggested that insecticide resistance in German cockroach field populations may be correlated with elevated activity of CarE.