Molecular characterization of a typical 2‐Cys thioredoxin peroxidase from the Asiatic rice borer Chilo suppressalis and its role in oxidative stress

• Published in: Archives of insect biochemistry and physiology Vol. 99; no. 1; pp. e21476 - n/a
• Main Authors: Cao, Ye, Yang, Qing, Tu, Xiao‐Hui, Li, Shi‐Guang, Liu, Su
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01-09-2018
• Subjects: Abamectin; Amino acid sequence; antioxidant defense; Antioxidants; Borers; Chilo suppressalis; Chlorpyrifos; Conserved sequence; Cyhalothrin; Deoxyribonucleic acid; DNA; DNA damage; E coli; Exposure; Hydrogen peroxide; Insecticide resistance; Insecticides; Insects; Midgut; Next-generation sequencing; Oxidation resistance; Oxidative stress; Pesticides; Proteins; Species classification; Thioredoxin peroxidase; Transcription; thioredoxin peroxidase; Chilo suppressalis; antioxidant defense; oxidative stress
• ISSN: 0739-4462; 1520-6327
• DOI: 10.1002/arch.21476

In insects, thioredoxin peroxidase (TPX) plays an important role in protecting against oxidative damage. However, studies on the molecular characteristics of TPXs in the Asiatic rice borer, Chilo suppressalis, are limited. In this work, a cDNA sequence (CsTpx3) encoding a TPX was identified from C. suppressalis. The deduced CsTPX3 protein shares high sequence identity and two positionally conserved cysteines with orthologs from other insect species, and was classified as a typical 2‐Cys TPX. CsTpx3 was expressed most highly during the fifth‐instar larval stage, and transcripts were most abundant in the midgut. Recombinant CsTPX3 protein expressed in Escherichia coli displayed the expected peroxidase activity by removing H2O2. Furthermore, CsTPX3 protected DNA from oxidative damage, and E. coli cells overexpressing CsTPX3 exhibited long‐term resistance to oxidative stress. Exposure to various oxidative stressors, such as cold (8°C), heat (35°C), bacteria (E. coli), and two insecticides (chlorpyrifos and lambda‐cyhalothrin), significantly upregulated transcription of CsTpx3. However, exposure to abamectin had no such effect. Our results provide valuable information for future studies on the antioxidant mechanism in this insect species.