Barley sodium content is regulated by natural variants of the Na+ transporter HvHKT1;5

Commun Biol. 2020 May 22;3(1):258. doi: 10.1038/s42003-020-0990-5.


During plant growth, sodium (Na+) in the soil is transported via the xylem from the root to the shoot. While excess Na+ is toxic to most plants, non-toxic concentrations have been shown to improve crop yields under certain conditions, such as when soil K+ is low. We quantified grain Na+ across a barley genome-wide association study panel grown under non-saline conditions and identified variants of a Class 1 HIGH-AFFINITY-POTASSIUM-TRANSPORTER (HvHKT1;5)-encoding gene responsible for Na+ content variation under these conditions. A leucine to proline substitution at position 189 (L189P) in HvHKT1;5 disturbs its characteristic plasma membrane localisation and disrupts Na+ transport. Under low and moderate soil Na+, genotypes containing HvHKT1:5P189 accumulate high concentrations of Na+ but exhibit no evidence of toxicity. As the frequency of HvHKT1:5P189 increases significantly in cultivated European germplasm, we cautiously speculate that this non-functional variant may enhance yield potential in non-saline environments, possibly by offsetting limitations of low available K+.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cation Transport Proteins / genetics
  • Cation Transport Proteins / metabolism*
  • Gene Expression Regulation, Plant*
  • Genome-Wide Association Study
  • Hordeum / genetics
  • Hordeum / growth & development
  • Hordeum / metabolism*
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plant Roots / genetics
  • Plant Roots / growth & development
  • Plant Roots / metabolism*
  • Plant Shoots / genetics
  • Plant Shoots / growth & development
  • Plant Shoots / metabolism*
  • Sodium / metabolism*


  • Cation Transport Proteins
  • Plant Proteins
  • Sodium