Genome-wide identification of a novel Na transporter from and overexpression of improved salt tolerance in .

Salt stress is an ever-increasing stressor that affects both plants and humans. Therefore, developing strategies to limit the undesirable effects of salt stress is essential. Sodium ion exclusion is well known for its efficient salt-tolerance mechanism. The High-affinity K Transporter (HKT) excludes excess Na from the transpiration stream. This study identified and characterized the HKT protein family in , a single-cell C plant. The and expression levels were examined in and leaves under four different salt stress conditions: 0, 100, 200, and 300 mM NaCl. Furthermore, was cloned, thereby producing stable transgenic . Our results showed that, compared to as a glycophyte, the HKT family is expanded in as a halophyte with three paralogs. The phylogenetic analysis revealed three paralogs belonging to the HKT subfamily I. Out of three copies, the expression of was higher in under control and salt stress conditions than in . Stable transgenic plants overexpressing showed higher salt tolerance than non-transgenic plants. Higher biomass and longer roots were observed in the transgenic plants under salt stress than in non-transgenic plants. This study demonstrates the evolutionary and functional differences in HKT proteins between glycophytes and halophytes and associates the role of in imparting salt tolerance and productivity.