CRISPR-Cas9-Mediated Knockout of Detoxification Genes in Helicoverpa armigera
DOI::
https://doi.org/10.70102/AEJ.2026.18.1.4کلمات کلیدی:
CRISPR-Cas9, Detoxification genes, Helicoverpa armigera, Insecticide resistance, Gene knockout.چکیده
Cotton bollworm, Helicoverpa armigera, is a devastating cotton and crop insect that causes over US$5 billion in losses in most parts of the world. The process of resistance against pyrethroid and organophosphate insecticides is largely contributed to by a transcription increase of detoxification genes that contain cytochrome P450 CYP6AE14, the glutathione S-transferase GSTe1, and carboxylesterase COE5 genes. To explore the effect of the three detoxification genes on the survival of a laboratory strain of H. armigera, the survival of a laboratory strain of H. armigera was attempted by silencing the three detoxification genes of H. armigera using CRISPR-Cas9 gene editing. GRNAs were also targeted at conserved exotic sites, and 52% hatch rate was achieved when 450 pre-blastoderm embryos were microinjected. Molecular screening was found to be more efficient, 61.3% in CYP6AE14, 58.7 in GSTe1, and 55.8 in COE5, with 72% frameshift mutations. Bioassays have found a high level of susceptibility to cypermethrin (RR is reduced to 3.1), chlorpyrifos (RR is reduced to 2.4), and methomyl (RR is reduced to 1.8) in 2022-2023. Enzyme activities were assessed to show that the activity of the enzyme P450, GST activity, and esterase activity were decreased by 78, 65, and 71% in triple knockout lines, respectively. However, there were fitness costs, which included 23% loss of larval survival, 18% loss of pupal weight, and 15% loss of fecundity. The research can be applied in understanding the action of some detoxification genes in insecticide resistance, and it is a platform for developing weak pest lines with the assistance of gene editing that can be incorporated as a component of an integrated pest management programme.