Prosopis strombulifera, a halophytic legume as potential biotechnological tool

LUNA, MARÍA VIRGINIA; REGINATO , MARIANA ANDREA; LLANES, ANALÍA SUSANA; SGROY, VERÓNICA; CASSÁN, FABRICIO

Buenos Aires

Simposio; Non Traditional Genetic Resources, V International Legumes Conference; 2010

Sociedad Argentina de Botánica

Breeding of salt resistant crops varieties will require a clear understanding of the complex mechanism of salt-stress tolerance, an understanding which is still incomplete despite intensive research during the last decade. As most studies have only used NaCl as the salinizing agent, the aim of this work was to evaluate the growth responses of Prosopis strombulifera (Lam.) Benth. seedlings to increasing concentrations of the two main salts present in central Argentina soils. Na2SO4, NaCl, and their iso-osmotic solution were used to study growth parameters, photosynthetic pigments, and ion content in comparison to non-treated plants. Prosopis strombulifera showed a halophytic response to NaCl but strong general growth inhibition with iso-osmotic solutions of Na2SO4. Both salts differentially affected ion accumulation, causing a different Na+/K+ ratio which depended on the salinizing agent used. Na2SO4-treated plants failed in osmotic adjustment. Photosynthetic pigment synthesis also changed according to the salt used. An important contribution of this study is given by the results obtained with salt mixtures; in bisaline-treated plants, almost all physiological parameters studied showed intermediate values within those measured when monosaline solutions were used, showing a partial alleviation of SO42- toxicity. Consequently, taking into consideration the realistic ion composition of most salinized soils, we demonstrate that ionic interactions between different salts can greatly modify the physiological responses of a given species to salinity. We propose this species as an excellent new model to increase our knowledge on extreme NaCl-tolerance mechanisms, as well as a biotechnological tool for improvement of economically important species.