title: Hydrogen peroxide produced by NADPH oxidases increases proline accumulation during salt or mannitol stress in Arabidopsis thaliana.
abstract: Many plants accumulate proline, a compatible osmolyte, in response to various environmental stresses such as water deficit and salinity. In some stress responses, plants generate hydrogen peroxide (H2 O2 ) that mediates numerous physiological and biochemical processes. The aim was to study the relationship between stress-induced proline accumulation and H2 O2 production. Using pharmacological and reverse genetic approaches in Arabidopsis thaliana, we investigated the role of NADPH oxidases, Respiratory burst oxidase homologues (Rboh), in the induction of proline accumulation was investigated in response to stress induced by either 200 mM NaCl or 400 mM mannitol. Stress from NaCl or mannitol resulted in a transient increase in H2 O2 content accompanied by accumulation of proline. Dimethylthiourea, a scavenger of H2 O2 , and diphenylene iodonium (DPI), an inhibitor of H2 O2 production by NADPH oxidase, were found to significantly inhibit proline accumulation in these stress conditions. DPI also reduced the expression level of Δ(1) -pyrroline-5-carboxylate synthetase, the key enzyme involved in the biosynthesis of proline. Similarly, less proline accumulated in knockout mutants lacking either AtRbohD or AtRbohF than in wild-type plants in response to the same stresses. Our data demonstrate that AtRbohs (A. thaliana Rbohs) contribute to H2 O2 production in response to NaCl or mannitol stress to increase proline accumulation in this plant.
authors.affiliation: Adaptation des Plantes aux Contraintes Environnementales, Case 156, Sorbonne Universités, UPMC Univ Paris 06, 4 place Jussieu, F-75005, Paris, France.|Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cedria (CBBC), BP 901, Hammam-Lif, 2050, Tunisia.
authors.forename: Kilani
authors.initials: K
authors.lastname: Ben Rejeb
authors.affiliation: Adaptation des Plantes aux Contraintes Environnementales, Case 156, Sorbonne Universités, UPMC Univ Paris 06, 4 place Jussieu, F-75005, Paris, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Lefebvre-De Vos
authors.affiliation: Adaptation des Plantes aux Contraintes Environnementales, Case 156, Sorbonne Universités, UPMC Univ Paris 06, 4 place Jussieu, F-75005, Paris, France.
authors.forename: Isabel
authors.initials: I
authors.lastname: Le Disquet
authors.affiliation: Adaptation des Plantes aux Contraintes Environnementales, Case 156, Sorbonne Universités, UPMC Univ Paris 06, 4 place Jussieu, F-75005, Paris, France.
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Leprince
authors.affiliation: Adaptation des Plantes aux Contraintes Environnementales, Case 156, Sorbonne Universités, UPMC Univ Paris 06, 4 place Jussieu, F-75005, Paris, France.
authors.forename: Marianne
authors.initials: M
authors.lastname: Bordenave
authors.affiliation: Adaptation des Plantes aux Contraintes Environnementales, Case 156, Sorbonne Universités, UPMC Univ Paris 06, 4 place Jussieu, F-75005, Paris, France.
authors.forename: Régis
authors.initials: R
authors.lastname: Maldiney
authors.affiliation: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cedria (CBBC), BP 901, Hammam-Lif, 2050, Tunisia.
authors.forename: Asma
authors.initials: A
authors.lastname: Jdey
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
authors.affiliation: Adaptation des Plantes aux Contraintes Environnementales, Case 156, Sorbonne Universités, UPMC Univ Paris 06, 4 place Jussieu, F-75005, Paris, France.
authors.forename: Arnould
authors.initials: A
authors.lastname: Savouré
mesh_terms: D000222:Adaptation, Physiological; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008353:Mannitol / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D019255:NADPH Oxidases / Q000378:metabolism; D011392:Proline / Q000378:metabolism*; D012965:Sodium Chloride / Q000378:metabolism*; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; D008353:Mannitol; D012965:Sodium Chloride; D011392:Proline; D006861:Hydrogen Peroxide; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; C022709:superoxide-forming enzyme
keywords: Arabidopsis thaliana; NADPH-oxidases (Rboh); abiotic stresses; cell signalling; hydrogen peroxide (H2O2); proline metabolism