Investigating imidacloprid resistance in Amrasca biguttula biguttula (Ishida) (Hemiptera: Cicadellidae): Insights from RNA-Seq and functional validation using RT-qPCR

The increasing challenge in agricultural insect pest management is the rapid development of insecticide resistance. Amrasca biguttula biguttula, a significant sap-sucking pest of cotton and other crops, causes severe damage through feeding and toxin injection while exhibiting resistance to multiple insecticides, including Imidacloprid. Understanding the genetic factors and mechanisms driving resistance in A. biguttula biguttula is crucial for effective pest control. This study utilized Illumina HiSeq sequencing to generate a transcriptome assembly and analyze differential gene expression in response to Imidacloprid. Differential expression analysis using DESeq2 identified 177 significantly expressed transcripts, with 67 upregulated and 110 downregulated. To validate these findings, the gene expression of selected genes in response to Imidacloprid exposure at LC₅₀ concentration (24.91 ppm) was tested at different time points (6 h, 12 h, and 24 h) relative to 0 h (control). The significant upregulation of detoxification-related genes such as cytochrome P450 monooxygenase (CYP303A1, CYP4DE1, CYP3184-fragment1 and CYP3939A2), three carboxylesterases (CE-1, CE-2, and CE-3), and one ABC transporter (ABC), highlights its potential role in Imidacloprid resistance. This study is the first to explore the molecular mechanisms underlying Imidacloprid resistance in A. biguttula biguttula and offers valuable insights for improving current pest management strategies.