Resistance toward Triflumezopyrim Related to Overexpression of SfUGT35A1 and SfGSTd2 in Sogatella furcifera (Hemiptera: Delphacidae)

Abstract

Sogatella furcifera is a migratory pest that harms rice cultivation. Triflumezopyrim (TFM), a novel insecticide, effectively controls S. furcifera. To guide its scientific application, we studied the TFM resistance mechanisms in resistant strains. Through cross-resistance determination, we found that the strain had cross-resistance to clothianidin. Synergistic and enzyme activities also demonstrated that the TFM resistance was related to the enhancement of glutathione S-transferases and UDPglycosyltransferases. Meanwhile, Sf GSTd2, Sf UGT2, and Sf UGT35A1 were invariably upregulated in the TFM-resistant strain. RNAi revealed that Sf GSTd2 (mortality increasing 33.3−53.3%) and Sf UGT35A1 (increasing 33.3−46.7%) significantly increased sensitivity on TFM, while Sf UGT35A1 (increasing 40.0−46.7%) also clearly promoted sensitivity toward clothianidin in S. furcifera. The GAL4/UAS system further verified that the overexpression of Sf UGT35A1 is involved in the formation of TFM (mortality descending 2.8−52.8%) and clothianidin resistance (mortality descending 11.1−41.7%). Therefore, all results showed that the overexpression of Sf GSTd2-and Sf UGT35A1-mediated resistance to TFM in S. furcifera.