title: Ion allocation in two different salt-tolerant Mediterranean Medicago species.
abstract: The relationship between Na+, major cation concentrations and salt tolerance under long-term saline conditions of Medicago arborea and Medicago citrina was studied. Plants were grown in solution culture in 1, 50, 100, or 200 mmol/L NaCl for 30 days in a climate-controlled greenhouse. Stem and petiole growth was the most affected by salt in both species. Leaf growth was inhibited in M. arborea, with increased salt, while only the 200 mmol/L NaCl-treated M. citrina plants were significantly affected. Both species had the highest Na+ concentrations in the shoots, however, the allocation pattern was different; M. arborea showed the highest concentrations in the leaf blades, whereas M. citrina distributed the salt into the petioles. K+/Na+ ratio decreased with salt in both species; however, leaf K+ use efficiency (g leaf DW mg-1 leaf K+) was higher in M. citrina. The difference in Na+ allocation and cation concentrations found in these medic species and their importance is discussed in relation to their response to NaCl salinity.
authors.affiliation: Department of Biology, Universitat de les Illes Balears, Cra. Valldemossa km. 7,5, 07071 Palma de Mallorca, Balears, Spain. dbsjsi4@clust.uib.es
authors.forename: John V
authors.initials: JV
authors.lastname: Sibole
authors.forename: Catalina
authors.initials: C
authors.lastname: Cabot
authors.forename: Charlotte
authors.initials: C
authors.lastname: Poschenrieder
authors.forename: Juan
authors.initials: J
authors.lastname: Barceló
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects / Q000502:physiology*; D008274:Magnesium / Q000378:metabolism; D029902:Medicago / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D019083:Mediterranean Region; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D013045:Species Specificity
chemical_list: D012965:Sodium Chloride; D012964:Sodium; D008274:Magnesium; D011188:Potassium