Abstract

Biotech crops, including those that are genetically modified (GM) with Bacillus thuringiensis (Bt) endotoxins for insect resistance, have been cultivated commercially and adopted in steadily increasing numbers of countries over the past 14 years. This review discusses the current status of insect resistant transgenic crops and the often raised concern that its resilience is limited and that its efficacy will be compromised by insect resistance. We consider this trait as it is currently deployed in fields across the world as well as potential candidates that are at various stages of development along the pathway between the laboratory and deregulation. Future trends and prospects for biotechnological applications to mediate crop protection against insects are also considered. These include strategies employing stacked genes, modified Bt toxins, vegetative insecticidal proteins, lectins, endogenous resistance mechanisms as well as novel approaches. In addition, the benefits and risks associated with the adoption of GM insect resistant crops, especially for developing countries and resource-poor smallholder farmers are also discussed.

Key words: Bacillus thuringiensis (Bt), endotoxins, Cry proteins, transgenic crops, insect resistance.

Abbreviation

GM, Genetically modified; Bt, Bacillus thuringiensis; Cry, crystal;Cyt, cytolitic; Vips, vegetative insecticidal proteins.