RESUMEN
Saline soil is a serious problem worldwide, and it is necessary to improve the salt tolerance of plants to avoid the progressive deterioration of saline soil. Agrobacterium based system was employed to transfer a vacuolar Na[+]/H[+] antiporter [AtNHX1] gene into tobacco leaf discs. Hundred thirty putative transgenic tobacco plants were obtained. The leaf painting assay was applied to select the transformants containing the bar gene [basta herbicide resistance]. In addition, the stable integration of the AtNHX1 gene was confirmed by PCR analysis. The expression of encoding sequence AtNHX1 gene was detected by the accumulation of salt in the transgenic tobacco plants under the salt stress conditions. Transgenic tobacco plants expressing the AtNHX1gene were able to grow in the presence of 150 to 300 mM NaCl and accumulated significantly at high concentrations of sodium ions in the leaves. However, the wild type plants could not tolerate a concentration up to 150 mM NaCl. This remarkable high salt tolerance in transgenic tobacco plants can be helpful in the future for applying important phytoremdiation plants in high saline lands