Characterization of UDP‐glycosyltranferase genes and their roles in chlorfenapyr tolerance in Glyphodes pyloalis Walker (Lepidoptera: Pyralidae)

Abstract

AbstractGlyphodes pyloalis Walker (Lepidoptera: Pyralidae) is the main pest of mulberry leaves and causes great losses to the sericultural industry in China. Chlorfenapyr is a new type of arylpyrrole insecticide in mulberry fields. Uridine diphosphate–glycosyltransferase (UGT) is the major phase II metabolizing enzymes that play important roles in detoxifying the toxic substances in insects. However, the roles of UGT genes against chemical insecticides in lepidopteran pests still receive less attention. To better understand the mechanism of insecticide tolerance in G. pyloalis, a LC50 of chlorfenapyr to the fourth‐instar larvae was firstly determined. Subsequently, 24 UGT genes were identified from the previous constructed larvae transcriptome of G. pyloalis. Among these, 23 contained full‐length ORFs and shared high homology with Ostrinia furnacalis and Chilo suppressalis. qRT‐PCR validation revealed that four GpylUGTs (GpUGT33AQ1, GpUGT33AS1, GpUGT50A14, and GpUGT40AV1) were significantly upregulated after 24 h of chlorfenapyr treatment. Three GpylUGTs (GpUGT33AS1, GpUGT40AM4, and GpUGT40AK7) were upregulated after 48 h of chlorfenapyr treatment compared to the control groups. To further explore the functions of UGT genes, GpUGT33AS1 was selected and knocked down, which resulted in the decline of UGT expression and significantly increased the mortality of G. pyloalis larvae under LC30 chlorfenapyr exposure. This study revealed that UGTs in G. pyloalis contributed to the tolerance towards chlorfenapyr and provided basic insight into the insecticide detoxification mechanism in lepidopteran pests.