SUPEROXIDE RADICALS, SUPEROXIDE DISMUTASES and OXYGEN TOXICITY IN PLANTS

作者：Haim D. Rabinowitch, Irwin Fridovich · 发表于：Photochemistry and Photobiology · 年份：1983 · DOI：10.1111/j.1751-1097.1983.tb04540.x · 被引用次数：218 · 研究领域：Paraquat toxicity studies and treatments、Photosynthetic Processes and Mechanisms、Pesticide and Herbicide Environmental Studies

Abstract In plants, as in other aerobic organisms, O2− is a commonly encountered intermediate of oxygen reduction and superoxide dismutases provide a defense against the potential cytotoxicity of this radical. The superoxide dismutases found in plants resemble those encountered in other organisms. Within chloroplasts one finds the CuZn enzyme, while mitochondria contain the Mn enzyme. Nymphaceae, ginkoaceae and cruciferae are unusual among plants, indeed among eukaryotes, in that they contain an iron superoxide dismutase. Bipyridylium herbicides, such as paraquat, exert their effect by diverting electron flow from photosystem I and thus increasing 02– production. Paraquat‐resistant genotypes of horseweed, tobacco and rye grass were found to contain elevated superoxide dismutase. This enzyme also appears to provide a defense against sulfur dioxide, sunscald and photooxidative death. The evidence supporting these statements and possible explanations are discussed.