柑橘全爪螨Na^＋-K^＋-ATPase的生化毒理学特性研究

Biochemical and toxicological characterizations of Na^+-K^+-ATPase in citrus red mite,Panonychus citri McGregor (Acari: Tetranychidae)

为明确柑橘全爪螨Na+-K+-ATPase与其抗药性之间的关系,采用微量滴度酶标板法对柑橘全爪螨敏感品系(SS)、甲氰菊酯抗性品系(FeR)和阿维菌素抗性品系(AvR)的Na+-K+-ATPase的生化毒理学特性进行了比较研究。结果表明,柑橘全爪螨Na+-K+-ATPase比活力从高到低依次为AvR、SS和FeR;柑橘全爪螨FeR的Na+-K+-ATPase的动力学参数Km和Vmax值均显著高于AvR和SS,AvR的Na+-K+-ATPase的Vmax值也显著高于SS。离体抑制作用测定结果表明,柑橘全爪螨3个品系Na+-K+-ATPase的活力均受到甲氰菊酯不同程度的抑制,其中对SS的抑制作用最强,其次为AvR,而对FeR的抑制作用显著弱于前2个品系;阿维菌素对柑橘全爪螨3个品系Na+-K+-ATPase的活力也有一定的抑制作用,在供试浓度范围(0.0229~2290.7146μmol.L-1)内抑制率仅为3.60%~12.76%。结果表明,柑橘全爪螨Na+-K+-ATPase活力降低及其对药剂敏感性下降是其对甲氰菊酯产生抗性的重要原因,Na+-K+-ATPase活性的提高可能与阿维菌素抗性形成有一定的关系。

In order to clarify the relationship between Na＋-K＋-ATPase and resistance of Panonychus citri,the biochemical and toxicological characterizations of Na＋-K＋-ATPase from three strains（Susceptible strain,SS;Fenpropathrin resistance strain,FeR;Avermectin resistance strain,AvR） of P.citri were studied using microplate reader method.The results showed that the specific activity of Na＋-K＋-ATPase from the highest to the lowest was AvR,SS,and FeR.The kinetic analysis showed that Km and Vmax values of Na＋-K＋-ATPase from FeR were significantly higher than those from the other two strains,and Vmax value from AvR was also higher than that from SS strain.In vitro inhibition of insecticides on Na＋-K＋-ATPase of P.citri showed that fenpropathrin expressed significant inhibitory effects under six tested concentrations.Na＋-K＋-ATPase of SS was the most sensitive to fenpropathrin,while Na＋-K＋-ATPase of FeR was the least.In addition,avermectin also exhibited some in vitro inhibition effect,and the inhibition rate on Na＋-K＋-ATPase of the three strains of P.citri ranged from 3.60 % to 12.76% at the avermectin concentration of 0.022 9 to 229 0.716 4 μmol·L-1.The above results indicated that Na＋-K＋-ATPase played a major role in fenpropathrin resistance of P.citri by its significantly lower activity and insensitivity to fenpropathrin inhibition,and the enhancement of Na＋-K＋-ATPase activity may play some roles in avermectin resistance of P.citri.