An epsilon class glutathione S-transferase gene contributes to the phytochemical susceptibility of Tribolium castaneum

Abstract Evidence is accumulating that insect epsilon class glutathione S-transferases (GSTes) play an important role in the resistance of xenobiotics such as insecticide. A Tribolium castaneum epsilon class GST gene, TcGSTe17 , could be significantly induced following exposure to plant derivative eucalyptol. However, whether TcGSTe17 involved in resistance to eucalyptol is still unclear. In this study, the TcGSTe17 was cloned from the T. castaneum genome, which exhibited the characteristic structural domain of epsilon class GSTs. In addition, molecular docking analysis showed that TcGSTe17 possibly could interact with eucalyptol. The expression profiling of stage showed that TcGSTe17 expressed at all development stages, of which highly expressed at late larvae. The expression profiling of tissue showed that TcGSTe17 highly expressed in gut of larvae and fat body of adults, respectively, and exhibited gender-different expression patterns as well. In addition, the transcripts of TcGSTe17 were significantly increased following exposure to eucalyptol, and RNAi heightened the susceptibility of beetles to eucalyptol. Overall, these results suggest that TcGSTe17 is required for the susceptibility of T. castaneum to eucalyptol. This study will contribute to the development of molecular targets, and provide scientific basis for developing eucalyptol as an insecticide.