title: Ascorbate is the natural substrate for plant peroxidases.
abstract: Ascorbate-dependent detoxification of hydrogen peroxide by guaiacol-type peroxidases is increased considerably in the presence of 3,4-dihydroxyphenolic compounds, suggesting that ascorbate is the natural substrate for many types of peroxidase in situ and not just the ascorbate-specific peroxidases. The ascorbate-dependent destruction of hydrogen peroxide in the more acidic cellular compartments such as the vacuole may be an important function of such non-specific peroxidases. The stress-induced production of phenolic compounds would render the guaiacol peroxidases in other less acidic-cellular sites effective as ascorbate-dependent H2O2-detoxifying enzymes.
authors.affiliation: Institut für Angewandte Botanik, Universität-GH-Essen, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Mehlhorn
authors.forename: M
authors.initials: M
authors.lastname: Lelandais
authors.forename: H G
authors.initials: HG
authors.lastname: Korth
authors.forename: C H
authors.initials: CH
authors.lastname: Foyer
mesh_terms: D000906:Antibodies; D060387:Ascorbate Peroxidases; D001205:Ascorbic Acid / Q000378:metabolism*; D002109:Caffeic Acids / Q000378:metabolism / Q000494:pharmacology; D002726:Chlorogenic Acid / Q000378:metabolism / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D004591:Electrophoresis, Polyacrylamide Gel; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D007525:Isoelectric Focusing; D007700:Kinetics; D010544:Peroxidases / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D010636:Phenols / Q000378:metabolism / Q000494:pharmacology; D010944:Plants / Q000201:enzymology*; D013379:Substrate Specificity; D013662:Tea / Q000201:enzymology
chemical_list: D000906:Antibodies; D002109:Caffeic Acids; D010636:Phenols; D013662:Tea; D002726:Chlorogenic Acid; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D010544:Peroxidases; D060387:Ascorbate Peroxidases; D001205:Ascorbic Acid; C040048:caffeic acid