A method of controlling corn rootworm feeding using a Bacillus thuringiensis protein expressed in transgenic maize

The corn rootworm (CRW: Diabrotica spp.) is one of the most serious pests of corn in the USA. Chemical insecticides and crop rotation have been the only two options available to growers for managing CRW. Unfortunately, both of these tactics can be ineffective as a result of either resistance or behavioral modifications. In this paper, we describe transgenic maize (Zea mays L.) hybrids that control CRW. These hybrids were created with a Cry3Bb1 Bacillus thuringiensis (Bt) variant that is approximately eight times more lethal to corn rootworm larvae than the wild-type protein. A DNA vector containing the modified crv3Bb1 gene was placed under control of a root-enhanced promoter (4-AS1) and was introduced into embryonic maize cells by microprojectile bombardment. Described here is the molecular genetic characterization, protein expression levels, and field performance of the recently commercialized MON863 hybrids.