title: Growth responses and ion accumulation in the halophytic legume Prosopis strombulifera are determined by Na2SO4 and NaCl.
abstract: Halophytes are potential gene sources for genetic manipulation of economically important crop species. This study addresses the physiological responses of a widespread halophyte, Prosopis strombulifera (Lam.) Benth to salinity. We hypothesised that increasing concentrations of the two major salts present in soils of central Argentina (Na2SO4, NaCl, or their iso-osmotic mixture) would produce distinct physiological responses. We used hydroponically grown P. strombulifera to test this hypothesis, analysing growth parameters, water relations, photosynthetic pigments, cations and anions. These plants showed a halophytic response to NaCl, but strong general inhibition of growth in response to iso-osmotic solutions containing Na2SO4. The explanation for the adaptive success of P. strombulifera in high NaCl conditions seems to be related to a delicate balance between Na(+) accumulation (and its use for osmotic adjustment) and efficient compartmentalisation in vacuoles, the ability of the whole plant to ensure sufficient K(+) supply by maintaining high K(+)/Na(+) discrimination, and maintenance of normal Ca(2+) levels in leaves. The three salt treatments had different effects on the accumulation of ions. Findings in bi-saline-treated plants were of particular interest, where most of the physiological parameters studied showed partial alleviation of SO4(2-)-induced toxicity by Cl(-). Thus, discussions on physiological responses to salinity could be further expanded in a way that more closely mimics natural salt environments.
authors.affiliation: Laboratorio de Fisiología Vegetal, Departamento de Ciencias Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Argentina.
authors.forename: M
authors.initials: M
authors.lastname: Reginato
authors.affiliation: Laboratorio de Fisiología Vegetal, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina.
authors.forename: L
authors.initials: L
authors.lastname: Sosa
authors.affiliation: Laboratorio de Fisiología Vegetal, Departamento de Ciencias Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Argentina.
authors.forename: A
authors.initials: A
authors.lastname: Llanes
authors.affiliation: Laboratorio de Suelos, Facultad de Agronomía y Veterinaria, Universidad Nacional de Río Cuarto, Río Cuarto, Argentina.
authors.forename: E
authors.initials: E
authors.lastname: Hampp
authors.affiliation: Laboratorio de Química Analítica, Departamento de Química, Universidad Nacional de Río Cuarto, Río Cuarto, Argentina.
authors.forename: N
authors.initials: N
authors.lastname: Vettorazzi
authors.affiliation: Laboratorio de Morfología Vegetal, Departamento de Ciencias Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Argentina.
authors.forename: H
authors.initials: H
authors.lastname: Reinoso
authors.affiliation: Laboratorio de Fisiología Vegetal, Departamento de Ciencias Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Argentina.
authors.forename: V
authors.initials: V
authors.lastname: Luna
mesh_terms: D007477:Ions; D029862:Prosopis / Q000254:growth & development* / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism*
chemical_list: D007477:Ions; D013431:Sulfates; C012036:sodium sulfate; D012965:Sodium Chloride
keywords: Chloride; halophytes; salt mixture; sulphate; toxicity alleviation