title: ROS Generation in Peroxisomes and its Role in Cell Signaling.
abstract: In plant cells, as in most eukaryotic organisms, peroxisomes are probably the major sites of intracellular H2O2production, as a result of their essentially oxidative type of metabolism. In recent years, it has become increasingly clear that peroxisomes carry out essential functions in eukaryotic cells. The generation of the important messenger molecule hydrogen peroxide (H2O2) by animal and plant peroxisomes and the presence of catalase in these organelles has been known for many years, but the generation of superoxide radicals (O2·-) and the occurrence of the metalloenzyme superoxide dismutase was reported for the first time in peroxisomes from plant origin. Further research showed the presence in plant peroxisomes of a complex battery of antioxidant systems apart from catalase. The evidence available of reactive oxygen species (ROS) production in peroxisomes is presented, and the different antioxidant systems characterized in these organelles and their possible functions are described. Peroxisomes appear to have a ROS-mediated role in abiotic stress situations induced by the heavy metal cadmium (Cd) and the xenobiotic 2,4-D, and also in the oxidative reactions of leaf senescence. The toxicity of Cd and 2,4-D has an effect on the ROS metabolism and speed of movement (dynamics) of peroxisomes. The regulation of ROS production in peroxisomes can take place by post-translational modifications of those proteins involved in their production and/or scavenging. In recent years, different studies have been carried out on the proteome of ROS metabolism in peroxisomes. Diverse evidence obtained indicates that peroxisomes are an important cellular source of different signaling molecules, including ROS, involved in distinct processes of high physiological importance, and might play an important role in the maintenance of cellular redox homeostasis.
authors.affiliation: Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry and Cell & Molecular Biology of Plants, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Apartado 419, E-18080 Granada, Spain luisalfonso.delrio@eez.csic.es.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Del Río
authors.affiliation: Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry and Cell & Molecular Biology of Plants, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Apartado 419, E-18080 Granada, Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: López-Huertas
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D020675:Peroxisomes / Q000378:metabolism* / Q000648:ultrastructure; D059828:Plant Cells / Q000378:metabolism*; D040901:Proteomics; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction; D013312:Stress, Physiological
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species
keywords: Cell metabolism; Hydrogen peroxide (H2O2); Peroxisomes; ROS generation; ROS signaling; Superoxide radicals (O2·–)