Citrus Research Institute, Southwest University, National Engineering Research Center for Citrus, Chongqing 400712, China.
Chongqing Institute for Food and Drug Control, Key Laboratory of Condiment Supervision Technology for State Market Regulation, Chongqing 401121, China.
Int J Biol Macromol. 2024 Jun;270(Pt 2):132228. doi: 10.1016/j.ijbiomac.2024.132228. Epub 2024 May 10.
Panonychus citri (McGregor) strains have developed a high level of resistance to abamectin, but the underlying molecular mechanism is unknown. Uridine diphosphate (UDP)-glycosyltransferases (UGTs) are critical for the removal of a variety of exogenous and endogenous substances. In this study, an enzyme activity assay revealed that UGTs potentially contribute to P. citri abamectin resistance. Spatiotemporal expression profiles showed that only PcUGT202A9 was significantly overexpressed in the abamectin-resistant strain (AbR) at all developmental stages. Moreover, UGT activity decreased significantly, whereas abamectin susceptibility increased significantly, in AbR after PcUGT202A9 was silenced. Three-dimensional modeling and molecular docking analyses revealed that PcUGT202A9 can bind stably to abamectin. Recombinant PcUGT202A9 activity was detected when α-naphthol was used, but the enzymatic activity was inhibited by abamectin (50 % inhibitory concentration: 803.3 ± 14.20 μmol/L). High-performance liquid chromatography and mass spectrometry analyses indicated that recombinant PcUGT202A9 can effectively degrade abamectin and catalyze the conjugation of UDP-glucose to abamectin. These results imply PcUGT202A9 contributes to P. citri abamectin resistance.
柑橘全爪螨（Panonychus citri）品系对阿维菌素产生了高水平的抗性，但潜在的分子机制尚不清楚。尿苷二磷酸（UDP）-糖基转移酶（UGTs）对于去除各种外源性和内源性物质至关重要。在本研究中，酶活性测定表明 UGTs 可能有助于柑橘全爪螨对阿维菌素的抗性。时空表达谱显示，在所有发育阶段，只有 PcUGT202A9 在阿维菌素抗性品系（AbR）中显著过表达。此外，沉默 PcUGT202A9 后，AbR 中的 UGT 活性显著降低，而对阿维菌素的敏感性显著增加。三维建模和分子对接分析表明，PcUGT202A9 可以与阿维菌素稳定结合。当使用α-萘酚时检测到重组 PcUGT202A9 的活性，但阿维菌素抑制了酶活性（50%抑制浓度：803.3±14.20μmol/L）。高效液相色谱和质谱分析表明，重组 PcUGT202A9 可以有效降解阿维菌素并催化 UDP-葡萄糖与阿维菌素的结合。这些结果表明 PcUGT202A9 有助于柑橘全爪螨对阿维菌素的抗性。
