RNA interference technologies to protect crop plants

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Insects are often considered our most serious competitors for food and fiber, reducing crop yields by inflicting damage to plants, propagating plant pathogens, and causing decay in stored food, fiber, and wood products. It has been estimated that insects consume or damage between 10 and 20% of the gross national products of most nations, despite our efforts to control the most noxious pests. Most control measures rely upon the use of broad-spectrum synthetic pesticides to control the pests. Unfortunately, these chemicals not only kill pests, but also kill non-target beneficial insects, and can adversely affect other invertebrate and vertebrate species. The primary objective of this research is to evaluate new species-specific pesticides for use in agriculture that may reduce negative impacts on non-target species. Two technologies in particular will be examined: RNA interference (RNAi) and insecticidal proteins derived from the soil bacterium Bacillus thuringiensis ("Bt" proteins). RNAi is a new technology that could revolutionize pest insect control, as it can selectively silence specific genes within the pests, but without affecting other species that do not share the exact gene sequences. As each species is defined by the uniqueness of its genetic code, this technology could be adapted to control many different pests in different cropping systems. Bt technology has been used effectively and safely for decades through the identification of bacterially-derived, natural insecticidal proteins with narrow host-specificities (obtained from Bacillus thuringiensis). Bt products were first used as foliar applications, but more recently during the past 20 years, select proteins have been identified and used in transgenic crops to selectively kill key insect pests. Plant protection from insect pests afforded by these technologies is expected to increase crop yields and reduce losses during storage, and consequently, increase profitability for Canada farmers and the agricultural industry. The development of environmentally-safer methods to controlling agricultural pests would also place Canada among the leaders in the agricultural biotechnology sector.