Transcriptome and Metabolome Analysis Reveals the Importance of Amino-Acid Metabolism in Spodoptera Frugiperda Exposed to Spinetoram

SIMPLE SUMMARY: The spinetoram was high toxicity toward Spodoptera frugiperda larvae in, and was recommended to control Spodoptera frugiperda in China. In order to explore the effect of spinetoram on S. frugiperda, we studied the effect of spinetoram on amino acid metabolism of S. frugiperda by transcriptome analysis and LC-MS/MS analysis. The results showed this pesticide induced the change of arginine, glutamic acid, aspartic acid, and lysine cause in larvae of S. frugiperda, which was one of the factors of larval death. And, the down-regulation of phenylalanine may retard the tricarboxylic acid cycle to produce GTP. The decrease in citric acid is associated with an increase in leucine. However, enhancement of glucose metabolism and tryptophan provides the basis for the restoration of normal physiological functions of S. frugiperda larvae. ABSTRACT: Pests are inevitably exposed to sublethal and lethal doses in the agroecosystem following the application of pesticides indispensable to protect food sources. The effect of spinetoram on amino-acid metabolism of fall armyworm, Spodoptera frugiperda (J.E. Smith), was investigated, at the dose of LC(10) and LC(90), by transcriptome and LC-MS/MS analysis. Using statistics-based analysis of both POS and NEG mode, a total of 715,501 metabolites in S. frugiperda were significantly changed after spinetoram treatment. The enhancement of glucose metabolism provides energy support for detoxification in larvae. The decrease in valine and isoleucine is associated with an increase in leucine, without maintaining the conservation of citric acid in the larvae. The down-regulation of phenylalanine may retard the tricarboxylic acid cycle to produce GTP. The abundance of lysine was decreased in response to spinetoram exposure, which damages the nervous system of the larvae. The abundance of arginine increases and causes non-functional contraction of the insect’s muscles, causing the larva to expend excess energy. Tryptophan provides an important substrate for eliminating ROS. The changes in glutamic acid, aspartic acid, and lysine cause damage to the nerve centers of the larvae. The results of transcriptome and LC-MS/MS analysis revealed the effects of pesticide exposure on amino-acid metabolism of S. frugiperda successfully and provide a new overview of the response of insect physio-biochemistry against pesticides.