Transcriptome Analysis of the Response of Aphis glycines Feeding on Ambrosia artemisiifolia

Common ragweed, Ambrosia artemisiifolia L., a noxious invasive plant, produces novel secondary metabolites. However, it attracts soybean aphid, Aphis glycines, a significant pest of soybean, to feed on it. Elucidating the molecular mechanisms of A. glycines adaptation to A. artemisiifolia may help identify target genes useful for pest management. High-throughput transcriptome sequencing identified 4250 differentially expressed genes (DEGs), with 2399 upregulated and 1851 downregulated. KEGG pathway enrichment analysis suggested that these DEGs were significantly involved in core detoxification-related pathways, including metabolism of xenobiotics by cytochrome P450, drug metabolism, ascorbate and aldarate metabolism, and pentose and glucuronate interconversions. Further analysis revealed significant upregulation of 17 UDP-glycosyltransferase (UGT) genes, with AgUGT342B2, AgUGT343B2, AgUGT344J2, AgUGT344L2, and AgUGT344N2 showing 6.34-, 6.22-, 2.14-, 3.98-, and 7.49-fold higher expression, respectively, than in A. glycines fed on soybean. Bioassays demonstrated that A. glycines reared on A. artemisiifolia exhibited significantly reduced sensitivity to three common insecticides, imidacloprid, thiamethoxam, and lambda-cyhalothrin, with LC50 values increasing by 5.8-fold, 2.8-fold, and 3.6-foldhigher, respectively, than those reared on soybean. These findings indicate that feeding on A. artemisiifolia induces UGT gene family upregulation in A. glycines, conferring cross-resistance to multiple insecticide classes. This study reveals a molecular mechanism linking host adaptation to insecticide resistance, highlighting the ecological and evolutionary consequences of invasive plant-herbivore interactions.