Improved salt tolerance in canola (Brasica napus) plants by overexpression of Arabidopsis Na+/H+ antiporter gene AtNHX1

A significant portion of the world’s cultivated land is affected by salinity that reduces crop productivity in these areas. Breeding for salt tolerance is one of the important strategies to overcome this problem. Recently, genetic engineering is becoming a promising approach to improving salt tolerance. In order to improve the yield performance of canola in saline soils, we transformed canola with Arabidopsis vacuolar Na+/H+ antiporter gene AtNHX1 which enhances the plant capacity for reducing cytosolic Na+ by transporting Na+ into the vacuole. Southern analysis of putative transgenic plants indicated that only one copy of the gene integrated into the plant genome. Overexpression of the AtNHX1 gene was shown in T1 transgenic plants. Under salinity conditions,  stem and root length and overall biomass of transgenic plants were significantly higher compared to those of nontransgenic plants. Moreover, salt treated transgenic plants contained high proline and K+, but less Na+ compared to wild type.