Mechanisms of sodium uptake by roots of higher plants

The negative impact of soil salinity on agricultural yields is significant. For agricultural plants, sensitivity to salinity is commonly (but not exclusively) due to the abundance of Na(+) in the soil as excess Na(+) is toxic to plants. We consider reducing Na(+) uptake to be the key, as well as the most efficient approach, to control Na(+) accumulation in crop plants and hence to improve their salt resistance. Understanding the mechanism of Na(+) uptake by the roots of higher plants is crucial for manipulating salt resistance. Hence, the aim of this review is to highlight and discuss recent advances in our understanding of the mechanisms of Na(+) uptake by plant roots at both physiological and molecular levels. We conclude that continued efforts to investigate the mechanisms of root Na(+) uptake in higher plants are necessary, especially that of low-affinity Na(+) uptake, as it is the means by which sodium enters into plants growing in saline soils.