Escherichia coli growing anaerobically respond to NO, with a 3-fold induction of the iron-containing superoxide dismutase. Mutants lacking nitrate reductase do not show this response. Anaerobically grown cells also contain an inactive form of the manganesecontaining superoxide dismutase (MnSOD) which can be activated by addition of Mn(I1) salts in the presence of acidic guanidinium chloride, fo...

Shoots, roots, and seeds of corn (Zea mays L., cv. Michigan 500), oats (Avena sativa L., cv. Au Sable), and peas (Pisum sativum L., cv. Wando) were analyzed for their superoxide dismutase content using a photochemical assay system consisting of methionine, riboflavin, and p-nitro blue tetrazolium. The enzyme is present in the shoots, roots, and seeds of the three species. On a dry weight basis,...

Superoxide dismutases (SODs) catalyze the dismutation of superoxide radicals in a broad range of organisms, including plants. Quantification of SOD activity in crude plant extracts has been problematic due to the presence of compounds that interfere with the dose-response of the assay. Although strategies exist to partially purify SODs from plant extracts, the requirement for purification limit...