Key Laboratory of Entomology and Pest Control Engineering of Chongqing, Southwest University, Chongqing 400716, China.
J Insect Physiol. 2010 Dec;56(12):1895-900. doi: 10.1016/j.jinsphys.2010.08.011. Epub 2010 Aug 24.
An abamectin-resistant strain of Tetranychus cinnabarinus (Boisduval) (Rf=25.3) was selected in laboratory. We compared the γ-aminobutyric acid (GABA) content in abamectin-susceptible T. cinnabarinus individuals with that in resistant individuals and investigated its relationship to abamectin resistance. High performance liquid chromatography (HPLC) was used to ascertain GABA content in abamectin-susceptible (SS) and resistant (AR) strains of T. cinnabarinus. The results indicate that GABA content in the AR was significantly higher than that in the SS (1.39-fold). AR individuals treated with a sublethal dose of abamectin did not show significant differences in GABA levels compared with AR individuals that were not treated with abamectin. However in the SS, abamectin treated individuals had a significantly higher GABA content than those that were untreated (1.52-fold). Individuals in the SS that survived from selection with LC(95) of abamectin (SS-AR) showed significantly higher GABA levels compared to SS (1.41-fold). Similarly, progenies of the SS-AR parental generation (SS-ARF(1)) also showed increased GABA levels (1.51-fold) compared to SS. In addition, behavioral observations have shown that all individuals from the AR, SS-AR and SS-ARF(1), which had more GABA content than the SS, demonstrated a significant decrease in crawling speed compared with SS individuals. This observation is consistent with excessive GABA levels had inhibitory effect on the central nervous system. Thus, we postulate that increasing GABA content in T. cinnabarinus is associated with resistance against abamectin.
已选育出对阿维菌素具有抗性的朱砂叶螨（Tetranychus cinnabarinus）（Rf=25.3）品系。我们比较了对阿维菌素敏感的朱砂叶螨个体与抗性个体的γ-氨基丁酸（GABA）含量，并研究了其与阿维菌素抗性的关系。采用高效液相色谱法（HPLC）测定对阿维菌素敏感（SS）和抗性（AR）品系朱砂叶螨的GABA 含量。结果表明，AR 中 GABA 含量明显高于 SS（1.39 倍）。用亚致死剂量阿维菌素处理的 AR 个体与未用阿维菌素处理的 AR 个体的 GABA 水平没有显著差异。然而，在 SS 中，用阿维菌素处理的个体的 GABA 含量明显高于未处理的个体（1.52 倍）。用阿维菌素 LC（95）进行选择后存活下来的 SS 个体（SS-AR）的 GABA 含量明显高于 SS（1.41 倍）。同样，SS-AR 亲本代（SS-ARF（1））的后代也表现出 GABA 水平的升高（1.51 倍），高于 SS。此外，行为观察表明，与 SS 个体相比，AR、SS-AR 和 SS-ARF（1）个体中所有 GABA 含量高于 SS 的个体的爬行速度均显著降低。这一观察结果与 GABA 水平过高对中枢神经系统产生抑制作用的假设一致。因此，我们推测朱砂叶螨中 GABA 含量的增加与对阿维菌素的抗性有关。
