Comparison of Assays for the Quantitation of Superoxide Dismustase in Apple and Potato Tissues

in HortScience
View More View Less
  • 1 USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Peoria, IL 61604.

The enzyme superoxide dismutase (SOD; EC catalyzes the conversion of the superoxide radical (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{O}_{2}^{-}\) \end{document}) to O2 and H2O2. SOD is thought to be critical in delaying aging and senescence in plant tissues such as apple fruit and potato tubers. A variety of assays have been reported for the quantitation of SOD based on the inhibition of O2-driven reactions. Four assays were examined, including 1) the reduction of nitro blue tetrazolium (NBT) by \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{O}_{2}^{-}\) \end{document}generated by the reaction of cysteine and FeCl3; 2) the reduction of NBT by \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{O}_{2}^{-}\) \end{document}generated by photochemical activation of riboflavin; 3) the inhibition of nitrite formation from hydroxylammonium chloride (nitrite subsequently converts sulfanilic acid to a diazonium compound, which reacts with α-naphthylamine to form a red azo compound); and 4) the autoxidation of hematoxylin to hematein by \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{O}_{2}^{-}\) \end{document}. In all cases, the production of colored compounds was inversely proportional to SOD activity. Although all of the assays were successful in quantitating SOD activity, assays 1 and 4 appeared simplest to use and had the fewest drawbacks.

If the inline PDF is not rendering correctly, you can download the PDF file here.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 34 3 0
PDF Downloads 49 14 0