title: Salicylic acid improves root antioxidant defense system and total antioxidant capacities of flax subjected to cadmium.
abstract: Cadmium (Cd) disrupts the normal growth and development of plants, depending on their tolerance to this toxic element. The present study was focused on the impacts of exogenous salicylic acid (SA) on the response and regulation of the antioxidant defense system and membrane lipids to 16-day-old flax plantlets under Cd stress. Exposure of flax to high Cd concentrations led to strong inhibition of root growth and enhanced lipid peroxides, membrane permeability, protein oxidation, and hydrogen peroxide (H2O2) production to varying degrees. Concomitantly, activities of the antioxidant enzymes catalase (CAT, EC 1.11.1.6), guaïcol peroxydase (GPX, EC 1.11.1.7), ascorbate peroxydase (APX, EC 1.11.1.11), and superoxide dismutase (SOD, EC 1.15.1.1), and the total antioxidant capacities (2,2'-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and ferric reducing antioxidant power (FRAP)) were significantly altered by Cd. In contrast, exogenous SA greatly reduced the toxic effects of Cd on the root growth, antioxidant system, and membrane lipid content. The Cd-treated plantlets pre-soaked with SA exhibited less lipid and protein oxidation and membrane alteration, as well as a high level of total antioxidant capacities and increased activities of antioxidant enzymes except of CAT. These results may suggest that SA plays an important role in triggering the root antioxidant system, thereby preventing membrane damage as well as the denaturation of its components.
authors.affiliation: Département de Biologie, Unité de Recherche de Physiologie et Biochimie de la tolérance des plantes aux contraintes abiotiques, Faculté des Sciences de Tunis, Campus Universitaire, Tunis, Tunisia. aicha585@yahoo.ca
authors.forename: Aïcha
authors.initials: A
authors.lastname: Belkadhi
authors.forename: Antonio
authors.initials: A
authors.lastname: De Haro
authors.forename: Pilar
authors.initials: P
authors.lastname: Soengas
authors.forename: Sara
authors.initials: S
authors.lastname: Obregon
authors.forename: Maria Elena
authors.initials: ME
authors.lastname: Cartea
authors.forename: Wahbi
authors.initials: W
authors.lastname: Djebali
authors.forename: Wided
authors.initials: W
authors.lastname: Chaïbi
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D002104:Cadmium / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects; D019597:Flax / Q000187:drug effects* / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects; D008054:Lipid Peroxides / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D010544:Peroxidases / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D008054:Lipid Peroxides; D002104:Cadmium; D006861:Hydrogen Peroxide; D010544:Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase; D020156:Salicylic Acid