Characterization of a sigma class GST (GSTS6) required for cellular detoxification and embryogenesis in Tribolium castaneum

• Published in: Insect science 2022-02, Vol.29 (1), p.215-229
• Main Authors: Song, Xiao‐Wen, Zhong, Qi‐Sheng, Ji, Yan‐Hao, Zhang, Yue‐Mei, Tang, Jing, Feng, Fan, Bi, Jing‐Xiu, Xie, Jia, Li, Bin
• Format: Article
• Language: English
• Subjects: Animals; antioxidant enzyme; Antioxidants; Carbofuran; Cumene; Cumene hydroperoxide; Cyhalothrin; Detoxification; Dichlorvos; Dinitrobenzene; Embryogenesis; Embryonic Development; Embryonic growth stage; Gene expression; Glutathione; glutathione S‐transferase; Glutathione Transferase - genetics; Glutathione Transferase - metabolism; Homology; Inactivation, Metabolic; insecticide resistance; Insecticides; Insects; Oxidative stress; Pesticides; Phoxim; Phylogeny; RNA-mediated interference; RNAi; Substrates; Tribolium - genetics; Tribolium - metabolism; Tribolium castaneum
• ISSN: 1672-9609; 1744-7917
• DOI: 10.1111/1744-7917.12930

The sigma glutathione S‐transferases (GSTSs) are a class of cytosolic glutathione S transferases (GSTs) that play important roles in antioxidant defense in insects, but the mechanisms by which GSTSs contribute to antioxidant activity remain unclear. Here, we isolated a GSTS (GSTS6) from Tribolium castaneum and explored its function. Homology and phylogenetic analysis revealed that TcGSTS6 shared high identity with other evolutionarily conserved GSTSs. The recombinant TcGSTS6 protein had strong activity toward cumene hydroperoxide and 4‐hydroxynonenal but low activity toward the universal substrate 1‐chloro‐2,4‐dinitrobenzene. Exposure to various types of oxidative stress, including heat, cold, UV and pathogenic microbes, significantly induced TcGSTs6 expression, which indicates that it is involved in antioxidant defense. Knockdown TcGSTs6 by using RNA interference (RNAi) caused reduced antioxidant capacity, which was accomplished by cooperating with other antioxidant genes. Moreover, treatment with various insecticides such as phoxim, lambda‐cyhalothrin, dichlorvos and carbofuran revealed that TcGSTS6 plays an important role in insecticide detoxification. The RNAi results showed that TcGSTS6 is essential for embryogenesis in T. castaneum. Our study elucidates the mechanism by which a GSTS contributes to antioxidant activity and enhances our understanding of the functional diversity of GSTSs in insects. TcGSTS6 plays important roles in cellular detoxification including insecticide resistance and antioxidant defense. The latter has been accomplished by cooperating with other antioxidant enzymes, which may be essential for the embryogenesis in Tribolium castaneum.