title: NADPH oxidase-dependent H2O2 production is required for salt-induced antioxidant defense in Arabidopsis thaliana.
abstract: The involvement of hydrogen peroxide (H2O2) generated by nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase) in the antioxidant defense system was assessed in salt-challenged Arabidopsis thaliana seedlings. In the wild-type, short-term salt exposure led to a transient and significant increase of H2O2 concentration, followed by a marked increase in catalase (CAT, EC 1.11.16), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) activities. Pre-treatment with either a chemical trap for H2O2 (dimethylthiourea) or two widely used NADPH oxidase inhibitors (imidazol and diphenylene iodonium) significantly decreased the above-mentioned enzyme activities under salinity. Double mutant atrbohd/f plants failed to induce the antioxidant response under the culture conditions. Under long-term salinity, the wild-type was more salt-tolerant than the mutant based on the plant biomass production. The better performance of the wild-type was related to a significantly higher photosynthetic activity, a more efficient K(+) selective uptake, and to the plants' ability to deal with the salt-induced oxidative stress as compared to atrbohd/f. Altogether, these data suggest that the early H2O2 generation by NADPH oxidase under salt stress could be the beginning of a reaction cascade that triggers the antioxidant response in A. thaliana in order to overcome the subsequent reactive oxygen species (ROS) production, thereby mitigating the salt stress-derived injuries.
authors.affiliation: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cedria (CBBC), BP 901, Hammam-Lif 2050, Tunisia; Adaptation des plantes aux contraintes environnementales, UR5, Université Pierre et Marie Curie (UPMC), Case 156, 4 Place Jussieu, 75252 Paris cedex 05, France. Electronic address: kilanib@yahoo.com.
authors.forename: Kilani
authors.initials: K
authors.lastname: Ben Rejeb
authors.affiliation: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cedria (CBBC), BP 901, Hammam-Lif 2050, Tunisia.
authors.forename: Maâli
authors.initials: M
authors.lastname: Benzarti
authors.affiliation: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cedria (CBBC), BP 901, Hammam-Lif 2050, Tunisia.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Debez
authors.affiliation: UMR 7622, UPMC Univ. Paris 06, CNRS, Bat C 2ème étage, 4, place Jussieu, 75005 Paris, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Bailly
authors.affiliation: Adaptation des plantes aux contraintes environnementales, UR5, Université Pierre et Marie Curie (UPMC), Case 156, 4 Place Jussieu, 75252 Paris cedex 05, France.
authors.forename: Arnould
authors.initials: A
authors.lastname: Savouré
authors.affiliation: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cedria (CBBC), BP 901, Hammam-Lif 2050, Tunisia.
authors.forename: Chedly
authors.initials: C
authors.lastname: Abdelly
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D060387:Ascorbate Peroxidases / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D005452:Fluoresceins / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005980:Glutathione Reductase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007093:Imidazoles / Q000494:pharmacology; D008315:Malondialdehyde / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism*; D009861:Onium Compounds / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological / Q000187:drug effects; D013890:Thiourea / Q000031:analogs & derivatives / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000975:Antioxidants; D029681:Arabidopsis Proteins; D060387:Ascorbate Peroxidases; D002374:Catalase; D005452:Fluoresceins; D005980:Glutathione Reductase; D006861:Hydrogen Peroxide; D007093:Imidazoles; D008315:Malondialdehyde; D019255:NADPH Oxidases; D009861:Onium Compounds; D012965:Sodium Chloride; D013890:Thiourea; C029569:diacetyldichlorofluorescein; C007517:diphenyleneiodonium; C029899:imidazole; C038983:1,3-dimethylthiourea; C000589475:RBOH F protein, Arabidopsis
keywords: Antioxidant defense system; Arabidopsis thaliana; Atrboh; H(2)O(2); Salinity