Acta Entomologica Sinica ›› 2024, Vol. 67 ›› Issue (9): 1173-1181.doi: 10.16380/j.kcxb.2024.09.001

• RESEARCH PAPERS •     Next Articles

Metabolic and antioxidant activities of the glutathione S-transferase SlGSTS4 of Spodoptera litura (Lepidoptera: Noctuidae) against the pyrethroid and organophosphate insecticides

LIU Ze-Zheng1, WANG Jia-Yin1, YUAN Ying-Qiu1, XU Li1, LIU Run-Qiang1, XU Yong-Gui2,*, LI Dong-Zhi1,*   

  1. (1. School of Resources and Environment, Henan Institute of Science and Technology, Xinxiang 453003, China; 2. Henan Science and Technology Exchange Center, Zhengzhou 450008, China)
  • Online:2024-09-20 Published:2024-10-22

Abstract:  【Aim】To investigate the role of the glutathione S-transferase SlGSTS4 of Spodoptera litura in the resistance to the pyrethroid and organophosphate insecticides.【Methods】The expression vector pET-26b(+)/SlGSTs4 was constructed and heterologously expressed in Escherichia coli. The recombinant SlGSTS4 protein was obtained, and the Michaelis constant Km and maximum speed Vmax of SlGSTS4 against the model substrate 1-chlom-2, 4-dinitrobenzene (CDNB) were determined. The metabolic rate of the recombinant SlGSTS4 and SlGSTS4-expressed E. coli to pyrethroid insecticides (fenvalerate, beta-cypermethrin and cyhalothrin) and organophosphate insecticides (chlorpyrifos and phoxim) were determined using ultra-performance liquid chromatography (UPLC). The antioxidant activity of SlGSTS4 under the stress of cumene hydrogen peroxide was determined by inhibition zone test using filter paper. 【Results】 The Vmax and Km values of the recombinant SlGSTS4 against CDNB were (13.8±2.3) nmol/(min·mg) and (1.66±0.1) mmol/L, respectively. The UPLC result indicated that the recombinant SlGSTS4 showed certain metabolic rate (4.9%) only to cyhalothrin, while had no metabolic activity to fenvalerate, beta-cypermethrin, phoxim or chlorpyrifos compared with the control. E. coli transformed with SlGSTS4 showed no influence on the residual peak area of fenvalerate, beta-cypermethrin, cyhalothrin, chlorpyrifos and phoxim, and decreased the inhibition zone diameter significantly compared with the control.【Conclusion】 SlGSTS4 showed no direct metabolic activity to pyrethroid or organophosphate insecticides, and exhibited obvious antioxidant activity. This study result has enriched the functional understanding of the GSTs Sigma family genes in S. litura, being helpful to clarify the function of SlGSTS4 in the resistance of S. litura to pyrethroid and organophosphate insecticides.

Key words: Spodoptera litura, SlGSTS4, pyrethroid insecticides, organophosphate insecticides, metabolic activity, antioxidant activity