Oxygen is necessary for life on earth because it drives crucial aerobic life processes. Ostensibly, oxygen also imposes universal toxicity as its reactions in living cells generate hydrogen peroxide and highly reactive free radicals of oxygen. These toxic by-products of oxygen metabolism are responsible for many deleterious processes such as peroxidation of essential lipids, alterations in genes, impaired protein synthesis and enzyme inactivation, aging and decrease in energy productions. Mammalian toxicologists have shown that several antioxidant enzymes are crucial for cell viability and organismal health, because they efficiently remove toxic oxygen products. Herbivorous insects constitute about half of the three- quarters of a million described species, and they are subject to both endogenous and exogenous sources of oxygen toxicity. The sources for exogenous oxygen toxicity are the pro-oxidant plant- defensive compounds called allelochemicals. A unique pattern of antioxidant enzymes has been discovered in recent years in insects. The proposed studies are designed to elucidate the role of these enzymes in protecting insects against oxygen toxicity derived from pro-oxidant allelochemicals. The long-term goal of this research is to gain the necessary basic information on the interaction of insects with plants, such that environmentally compatible insect pest control techniques can be developed.
