title: Ascorbate Peroxidase and Catalase Activities and Their Genetic Regulation in Plants Subjected to Drought and Salinity Stresses.
abstract: Hydrogen peroxide (H2O2), an important relatively stable non-radical reactive oxygen species (ROS) is produced by normal aerobic metabolism in plants. At low concentrations, H2O2 acts as a signal molecule involved in the regulation of specific biological/physiological processes (photosynthetic functions, cell cycle, growth and development, plant responses to biotic and abiotic stresses). Oxidative stress and eventual cell death in plants can be caused by excess H2O2 accumulation. Since stress factors provoke enhanced production of H2O2 in plants, severe damage to biomolecules can be possible due to elevated and non-metabolized cellular H2O2. Plants are endowed with H2O2-metabolizing enzymes such as catalases (CAT), ascorbate peroxidases (APX), some peroxiredoxins, glutathione/thioredoxin peroxidases, and glutathione sulfo-transferases. However, the most notably distinguished enzymes are CAT and APX since the former mainly occurs in peroxisomes and does not require a reductant for catalyzing a dismutation reaction. In particular, APX has a higher affinity for H2O2 and reduces it to H2O in chloroplasts, cytosol, mitochondria and peroxisomes, as well as in the apoplastic space, utilizing ascorbate as specific electron donor. Based on recent reports, this review highlights the role of H2O2 in plants experiencing water deficit and salinity and synthesizes major outcomes of studies on CAT and APX activity and genetic regulation in drought- and salt-stressed plants.
authors.affiliation: School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, 85100 Potenza, Italy. adriano.sofo@unibas.it.
authors.forename: Adriano
authors.initials: A
authors.lastname: Sofo
authors.affiliation: School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, 85100 Potenza, Italy. antonio.scopa@unibas.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Scopa
authors.affiliation: School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, 85100 Potenza, Italy. maria.nuzzaci@unibas.it.
authors.forename: Maria
authors.initials: M
authors.lastname: Nuzzaci
authors.affiliation: School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, 85100 Potenza, Italy. antonella.vitti@unibas.it.
authors.forename: Antonella
authors.initials: A
authors.lastname: Vitti
mesh_terms: D060387:Ascorbate Peroxidases / Q000235:genetics / Q000378:metabolism*; D002374:Catalase / Q000235:genetics / Q000378:metabolism*; D055864:Droughts; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D010944:Plants / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D054712:Salinity; D013312:Stress, Physiological
chemical_list: D010940:Plant Proteins; D060387:Ascorbate Peroxidases; D002374:Catalase
keywords: abiotic stress; ascorbate peroxidase (APX); catalase (CAT); hydrogen peroxide (H2O2); reactive oxygen species (ROS)