Molecular characterization of glutathione-S-transferase (AiGSTs1) in Agrotis ipsilon subject to insecticide stress
Author of the article:LI Mao-Ye HUANG Yan JIANG Xiu-Yun HE Ji-Xian LIU Su
Author's Workplace：Anhui Province Key Laboratory of Integrated Pest Management on Crops, Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China; Sichuan Guangyuan Tobacco Company, Guangyuan 628017, China
Key Words：Agrotis ipsilon; GST; expression; chlorpyrifos; lambda-cyhalothrin; metabolic detoxification
Abstract：
[Objectives] To provide a theoretical basis for exploring
the role of GSTs in insecticide detoxification in Agrotis ipsilon by identifying the sigma class glutathione-S-transferase (GST) gene in A. ipsilon,
determining the catalytic activity of the protein encoded by this gene, and
elucidating its expression patterns in different developmental stages, tissues,
and in response to the stress induced by chlorpyrifos and lambda-cyhalothrin. [Methods] The A.
ipsilon GST gene was identified
from transcriptome data using a homological search method. Recombinant protein
was expressed in a prokaryotic expression system and its activity detected with
commercial kits. The expression pattern of the gene was analyzed using reverse
transcription quantitative PCR. [Results] A cDNA (designated AiGSTs1) sequence encoding a putative
sigma class GST was identified in the A.
ipsilon transcriptome. Protein encoded by AiGSTs1 contain glutathione-binding and substrate-binding sites,
which are typical characteristics of GSTs. Recombinant AiGSTs1 protein was
expressed in Escherichia coli, and
this protein displayed not only GST activity but also peroxidase activity. In
addition, the activity of AiGSTs1 was significantly inhibited by chlorpyrifos
and lambda-cyhalothrin. AiGSTs1 mRNA
was detectable in different developmental stages and tissues. Highest
expression was in the pupal stage and the larval fat body. Furthermore, AiGSTs1 transcription levels were
significantly upregulated in larvae exposed to LD50 doses of
chlorpyrifos and lambda-cyhalothrin. [Conclusion]
Transcription of AiGSTs1 can be induced by chlorpyrifos
and lambda-cyhalothrin, which suggests that the AiGSTs1 gene may play essential roles in the metabolic detoxification
of these insecticides.