title: Effect of sulphur deprivation on osmotic potential components and nitrogen metabolism in oilseed rape leaves: identification of a new early indicator.
abstract: Identification of early sulphur (S) deficiency indicators is important for species such as Brassica napus, an S-demanding crop in which yield and the nutritional quality of seeds are negatively affected by S deficiency. Because S is mostly stored as SO4 (2-) in leaf cell vacuoles and can be mobilized during S deficiency, this study investigated the impact of S deprivation on leaf osmotic potential in order to identify compensation processes. Plants were exposed for 28 days to S or to chlorine deprivation in order to differentiate osmotic and metabolic responses. While chlorine deprivation had no significant effects on growth, osmotic potential and nitrogen metabolism, Brassica napus revealed two response periods to S deprivation. The first one occurred during the first 13 days during which plant growth was maintained as a result of vacuolar SO4 (2-) mobilization. In the meantime, leaf osmotic potential of S-deprived plants remained similar to control plants despite a reduction in the SO4 (2-) osmotic contribution, which was fully compensated by an increase in NO3 (-), PO4 (3-) and Cl(-) accumulation. The second response occurred after 13 days of S deprivation with a significant reduction in growth, leaf osmotic potential, NO3 (-) uptake and NO3 (-) reductase activity, whereas amino acids and NO3 (-) were accumulated. This kinetic analysis of S deprivation suggested that a ([Cl(-)]+[NO3 (-)]+[PO4 (3-)]):[SO4 (2-)] ratio could provide a relevant indicator of S deficiency, modified nearly as early as the over-expression of genes encoding SO4 (2-) tonoplastic or plasmalemmal transporters, with the added advantage that it can be easily quantified under field conditions.
authors.affiliation: Normandie Université, 14032 Caen, France UNICAEN, UMR 950 Ecophysiologie Végétale, Agronomie et nutritions N, C, S, Esplanade de la Paix, CS14032, 14032 Caen Cedex 5, France INRA, UMR 950 Ecophysiologie Végétale, Agronomie et nutritions N, C, S, Esplanade de la Paix, CS14032, 14032 Caen Cedex 5, France Centre de Recherche International en Agroscience, CRIAS-TAI, Groupe Roullier, 55 Boulevard Jules Verger, 35800 Dinard, France.
authors.forename: Elise
authors.initials: E
authors.lastname: Sorin
authors.affiliation: Normandie Université, 14032 Caen, France UNICAEN, UMR 950 Ecophysiologie Végétale, Agronomie et nutritions N, C, S, Esplanade de la Paix, CS14032, 14032 Caen Cedex 5, France INRA, UMR 950 Ecophysiologie Végétale, Agronomie et nutritions N, C, S, Esplanade de la Paix, CS14032, 14032 Caen Cedex 5, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Etienne
authors.affiliation: Normandie Université, 14032 Caen, France UNICAEN, UMR 950 Ecophysiologie Végétale, Agronomie et nutritions N, C, S, Esplanade de la Paix, CS14032, 14032 Caen Cedex 5, France INRA, UMR 950 Ecophysiologie Végétale, Agronomie et nutritions N, C, S, Esplanade de la Paix, CS14032, 14032 Caen Cedex 5, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Maillard
authors.affiliation: Timac Agro Spain, Poligono de Arazuri-Orcoyen Calle C No. 32, 31160 Orcoyen, Spain.
authors.forename: Angel-Mari
authors.initials: AM
authors.lastname: Zamarreño
authors.affiliation: Timac Agro Spain, Poligono de Arazuri-Orcoyen Calle C No. 32, 31160 Orcoyen, Spain.
authors.forename: José-Maria
authors.initials: JM
authors.lastname: Garcia-Mina
authors.affiliation: Centre de Recherche International en Agroscience, CRIAS-TAI, Groupe Roullier, 55 Boulevard Jules Verger, 35800 Dinard, France.
authors.forename: Mustapha
authors.initials: M
authors.lastname: Arkoun
authors.affiliation: Centre de Recherche International en Agroscience, CRIAS-TAI, Groupe Roullier, 55 Boulevard Jules Verger, 35800 Dinard, France.
authors.forename: Frank
authors.initials: F
authors.lastname: Jamois
authors.affiliation: Centre de Recherche International en Agroscience, CRIAS-TAI, Groupe Roullier, 55 Boulevard Jules Verger, 35800 Dinard, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Cruz
authors.affiliation: Centre de Recherche International en Agroscience, CRIAS-TAI, Groupe Roullier, 55 Boulevard Jules Verger, 35800 Dinard, France.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Yvin
authors.affiliation: Normandie Université, 14032 Caen, France UNICAEN, UMR 950 Ecophysiologie Végétale, Agronomie et nutritions N, C, S, Esplanade de la Paix, CS14032, 14032 Caen Cedex 5, France INRA, UMR 950 Ecophysiologie Végétale, Agronomie et nutritions N, C, S, Esplanade de la Paix, CS14032, 14032 Caen Cedex 5, France alain.ourry@unicaen.fr.
authors.forename: Alain
authors.initials: A
authors.lastname: Ourry
mesh_terms: D029688:Brassica napus / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism*; D009995:Osmosis / Q000502:physiology*; D018515:Plant Leaves / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism*; D013455:Sulfur / Q000172:deficiency*
chemical_list: D009566:Nitrates; D013431:Sulfates; D013455:Sulfur
keywords: Brassica napus; chlorine deprivation; indicator of S deficiency; nitrogen metabolism; osmotic potential; sulphur deprivation.