Engineering insect resistance using plant specialized metabolites

Plants in nature are protected against insect herbivory by a wide variety of specialized metabolites. Although insect herbivores generally tolerate the defensive metabolites of their preferred host plants, the presence of additional chemical defenses in otherwise closely related plant species can nevertheless provide resistance. This chemical resistance to insect herbivory can be enhanced by genetic engineering to increase the production of endogenous defensive metabolites, modify existing biochemical pathways, or move the biosynthesis of entirely new classes of specialized metabolites into recipient plants. However, current plant genetic engineering strategies are limited by insufficient knowledge of the biosynthetic pathways of plant specialized metabolism, unintended side-effects that result from redirecting plant metabolism, inadequate transgene construction and delivery methods, and requirements for tissue-specific production of defensive metabolites to enhance herbivore resistance.