Insecticidal protein protects against western corn rootworms

Genetically modified (GM) crops often require fewer pesticides compared with their conventional counterparts, thanks to their engineered ability to produce their own insecticides, a trait derived from the bacterium Bacillus thuringiensis (Bt). But insects such as the western corn rootworm are developing resistance to commonly used Bt insecticides, allowing them to happily munch their way through crop roots. Eager for a fresh combat strategy against corn rootworm, scientists at DuPont Pioneer began digging through the dirt to discover potent new insecticides produced by soil bacteria. They found IPD072Aa, a previously unknown protein produced by Pseudomonas chloroaphis (Science 2016, DOI: 10.1126/science.aaf6056). After inserting the gene for IPD072Aa into corn, the researchers found that their plants were effective at killing corn rootworm larvae, even if those larvae were resistant to Bt corn. Tom Greene, a research director who oversaw the work, says this “opens the door to new insecticidal proteins that potentially represent new modes of action.” Greene anticipates IPD072Aa working synergistically with Bt insecticides in future seed products.