Transformation and Expression of Na+/H+ Antiporter Vacuolar (AgNHX1) Gene in Potato (Solanum Tuberosum L.) Plants Under Salt Stress

Abstract Salinity is the main influencing factor in the productivity of most agricultural crops. Salinity has a negative effect on potato plants and yield. Previous research work shows that the transfer of the Na+/H+ antiporter gene to field crops improves the tolerance of plants to high salt concentrations. In this study, a vacuolar-type Na+/H+ antiporter gene from a halophytic plant, Atriplex gmelinii (AgNHX1) was transferred into potato via Agrobacterium. Leaf explants induced callus on Murashige & Skoog's (MS) medium accompanied by NAA (2.00 mg l-1) and BAP (0.25 mg l-1). The in-vitro leaf generated the callus which was transferred to the regeneration medium containing ZR (2.00 mg l-1) and NAA (0.25 mg l-1). The stable integration of the AgNHX1 gene in genetically modified potato plants was confirmed by PCR analysis. RT-PCR and northern blot hybridization indicated that AgNHX1expressed highly in transgenic potato plants. Our results indicated that the expression of AgNHX1 enhanced the salt tolerance in transgenic potato plants with good growth. This happened because, under salt stress, the accumulation of Na+ content and proline was more in shoots as compared to control. It showed that the expression of AgNHX1 activity in genetically modified potato plants was four-fold higher than in unmodified potato plants. Thus, it can be said that AgNHX1 gene expression could increase salt tolerance in potato plants.