title: Plant catalases: peroxisomal redox guardians.
abstract: While genomics and post-genomics studies have revealed that plant cell redox state is controlled by a complex genetic network, available data mean that catalase must continue to be counted among the most important of antioxidative enzymes. Plants species analyzed to date contain three catalase genes, and comparison of expression patterns and information from studies on mutants suggests that the encoded proteins have relatively specific roles in determining accumulation of H(2)O(2) produced through various metabolic pathways. This review provides an update on the different catalases and discusses their established or likely physiological functions. Particular attention is paid to regulation of catalase expression and activity, intracellular trafficking of the protein from cytosol to peroxisome, and the integration of catalase function into the peroxisomal antioxidative network. We discuss how plants deficient in catalase are not only key tools to identify catalase functions, but are also generating new insight into H(2)O(2) signalling in plants and the potential importance of peroxisomal and other intracellular processes in this signalling.
authors.affiliation: Institut de Biologie des Plantes, UMR CNRS 8618, Université de Paris sud 11, 91405 Orsay Cedex, France. amna.mhamdi@u-psud.fr
authors.forename: Amna
authors.initials: A
authors.lastname: Mhamdi
authors.forename: Graham
authors.initials: G
authors.lastname: Noctor
authors.forename: Alison
authors.initials: A
authors.lastname: Baker
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D002374:Catalase / Q000737:chemistry*; D003600:Cytosol / Q000378:metabolism; D005227:Fatty Acids / Q000737:chemistry; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D023281:Genomics; D006861:Hydrogen Peroxide / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D008954:Models, Biological; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010101:Oxygen Consumption; D020675:Peroxisomes / Q000378:metabolism; D010788:Photosynthesis; D010802:Phylogeny; D018521:Plant Physiological Phenomena; D010944:Plants / Q000201:enzymology* / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D005227:Fatty Acids; D008055:Lipids; D006861:Hydrogen Peroxide; D002374:Catalase; D010100:Oxygen