Use of gut binding peptides as artificial anchors for bacterial pesticidal proteins

Despite the successful use of bacterial pesticidal proteins (BPP) for suppression of lepidopteran and coleopteran pests, hemipteran pests formerly of secondary importance have emerged as primary pests in response to declining insecticide application. However, there are relatively few BPP with sufficient toxicity against hemipteran pest species for deployment at the high dose warranted for effective resistance management. To address these limitations, BPP from diverse structural classes can be screened for high toxicity against each pest species within a given cropping system. In addition, BPP with limited toxicity can be modified for improved efficacy. Here we provide an overview of the use of gut binding peptides as artificial anchors to increase binding of the BPP to the surface of the gut epithelium in the target insect. We describe methods for the selection of gut binding peptides, considerations for the selection of sites and strategies for BPP modification, and examples where gut binding peptides have been used to enhance BPP toxicity or in an attempt to overcome BPP resistance. We also discuss the importance of knowledge of insect gut physiology and BPP mode of action for successful outcomes from gut binding peptide modification.