Abstract: In order to explore the function of glutathione S-transferases (GSTs) in olfactory recognition of insects, the full-length cDNA of a novel glutathione S-transferase gene was cloned from the antennae of Helicoverpa assulta by using RT-PCR and RACE methods (GenBank accession no. EU289223). Based on the sequence identity and the phylogenetic tree of the amino acids of GSTs in H. assulta and other species， the sequence obtained was found to belong to the Epsilon family， hence named as HaGSTe1. Genomic structure analysis of HaGSTe1 revealed that HaGSTe1 contained five introns with the length of 415, 513, 296, 333 and 269 bp, respectively. The qualitative and quantitative analyses of the expression of HaGSTe1 in male and female moths were conducted using semi-quantitative RT-PCR and real-time PCR. The results showed that HaGSTe1 transcript was clearly detected in the head (with antennae and proboscis removed), antenna, proboscis, thorax, legs, and wings of both male and female and abdomen of the female. HaGSTe1 transcript was significantly more highly expressed in male antennae than in female antennae, suggesting that it may be involved with the decomposition of pheromones and other xenobiotics in the antenna.

Key words: Helicoverpa assulta, glutathione S-transferase, gene cloning, semi-quantitative PCR, real-time PCR