Biotech Updates

ISU Researchers Retarget Bt Toxin Against Hemipteran Insect Pests

May 29, 2013

Bacillus thuringiensis (Bt) genes have been successfully expressed in biotech crops to fight lepidopteran and coleopteran pest species. However, sap-sucking insects (hemipterans) are not susceptible to Bt proteins. To address this concern, Nanasaheb Chougule of Iowa State University and colleagues added a short peptide sequence for Bt protein to bind in the gut of target pest species and increase the efficacy of the protein.

The researchers inserted a 12-amino acid pea aphid gut-binding peptide by adding to or replacing amino acids in one of the three loops of the Bt cytolytic toxin (Cyt2Aa). This led to improved binding and toxicity against hemipterans called pea aphid (Acyrthosiphon pisum) and green peach aphid (Myzus persicae).

Based on the results, the technique used in the study may be used to develop transgenic plant-mediated suppression of hemipteran pests, especially those that threaten global agriculture.

Read the research article at