Abstract
Emamectin benzoate (EB), a derivative of avermectin, is the primary insecticide used to control the fall armyworm (FAW) in China. However, the specific molecular targets of EB against FAW remain unclear. In this study, we cloned the glutamate-gated chloride channel (GluCl) gene, which is known to be a primary molecular target for avermectin. We first investigated the transcript levels of SfGluCl in FAW and found that the expression level of SfGluCl in the head and nerve cord was significantly higher than that in other tissues. Furthermore, we found that the expression level of SfGluCl was significantly higher in eggs than that in other developmental stages, including larvae, pupae, and adults. Additionally, we identified three variable splice forms of SfGluCl in exons 3 and 9 and found that their splice frequencies remained unaffected by treatment with the LC50 of EB. RNAi mediated knockdown of SfGluCl showed a significant reduction of 42% and 65% after 48 and 72 h of dsRNA feeding, respectively. Importantly, knockdown of SfGluCl sifgnificantly reduced LC50 and LC90 EB treatment induced mortality of FAW larvae by 15% and 44%, respectively, compared to the control group feeding by dsEGFP. In contrast, there were no significant changes in the mortality of FAW larvae treated with the control insecticides chlorantraniliprole and spinetoram. Finally, molecular docking simulations revealed that EB bound to the large amino-terminal extracellular domain of SfGluCl by forming five hydrogen bonds, two alkyl hydrophobic interactions and one salt bridge. These findings strongly suggest that GluCl may serve as one of the molecular targets of EB in FAW, shedding light on the mode of action of this important insecticide.
Original language | English |
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Article number | 105636 |
Journal | Pesticide Biochemistry and Physiology |
Volume | 196 |
DOIs | |
State | Published - Nov 2023 |
Bibliographical note
Funding Information:We thank Prof. Zengxia Wang from Anhui Science and Technology University for presenting the sensitive strain of fall armyworm (FAW), Spodoptera frugiperda. This work was supported by National Natural Science Foundation of China (grant No. 32001931 ), Anhui Provincial Natural Science Foundation, China (grant No. 2308085MC89 and 2008085QC159 ) and the Scientific Research Foundation of Higher Education of Anhui Province, China (grant No. 2023AH051014 ).
Funding Information:
We thank Prof. Zengxia Wang from Anhui Science and Technology University for presenting the sensitive strain of fall armyworm (FAW), Spodoptera frugiperda. This work was supported by National Natural Science Foundation of China (grant No. 32001931), Anhui Provincial Natural Science Foundation, China (grant No. 2308085MC89 and 2008085QC159) and the Scientific Research Foundation of Higher Education of Anhui Province, China (grant No. 2023AH051014).
Publisher Copyright:
© 2023 Elsevier Inc.
Keywords
- Alternative splicing
- Emamectin benzoate
- Glutamate-gated chloride channel
- Molecular docking
- RNA interference
- Spodoptera frugiperda
ASJC Scopus subject areas
- Agronomy and Crop Science
- Health, Toxicology and Mutagenesis