Two carboxyl/choline esterase (CCE) genes, TuCCE11 and TuCCE34, are related to abamectin resistance in Tetranychus urticae Koch.

Tetranychus urticae is a widespread agricultural pest that exhibits highly intractable resistance to multiple acaricides, particularly abamectin. The rapid and complex evolution of insecticide resistance, along with the molecular mechanisms of abamectin resistance in T. urticae, are not fully elucidated, representing a significant impediment to the effective management of pest resistance. Carboxyl/choline esterase (CCE) is a member of the serine hydrolases involved in the initial phase of pesticide detoxification metabolism. In this study, 51 T. urticae CCE genes were identified based on the transcriptome and genome data of T. urticae strains from China. The transcript expressions of some CCE genes were significantly upregulated in resistant populations in comparison to the susceptible strain. Moreover, transcript levels were observed to increase in T. urticae following exposure to abamectin. Additionally, RNA interference (RNAi)-mediated silencing of TuCCE11 and TuCCE34 increased susceptibility to abamectin in T. urticae. The molecular docking analysis revealed that the higher binding energy of abamectin to TuCCE11 and TuCCE34 was -9.01 and -9.00 kcal/mol, respectively. In conclusion, the results of the present study indicate that TuCCE11 and TuCCE34 may play a role in the development of abamectin resistance in T. urticae.