Shoot sodium exclusion in salt stressed barley (Hordeum vulgare L.) is determined by allele specific increased expression of HKT1;5

Roel F.H.M. van Bezouw*, Elly M. Janssen, Md Ashrafuzzaman, Robab Ghahramanzadeh, Benjamin Kilian, Andreas Graner, Richard G.F. Visser, Gerard van der Linden

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

High affinity potassium transporters (HKT) are recognized as important genes for crop salt tolerance improvement. In this study, we investigated HvHKT1;5 as a candidate gene for a previously discovered quantitative trait locus that controls shoot Na+ and Na+/K+ ratio in salt-stressed barley lines on a hydroponic system. Two major haplotype groups could be distinguished for this gene in a barley collection of 95 genotypes based on the presence of three intronic insertions; a designated haplotype group A (HGA, same as reference sequence) and haplotype group B (HGB, with insertions). HGB was associated with a much stronger root expression of HKT1;5 compared to HGA, and consequently higher K+ and lower Na+ and Cl concentrations and a lower Na+/K+ ratio in the shoots three weeks after exposure to 200 mM NaCl. Our experimental results suggest that allelic variation in the promoter region of the HGB gene is linked to the three insertions may be responsible for the observed increase in expression of HvHKT1;5 alleles after one week of salt stress induction. This study shows that in barley - similar to wheat and rice - HKT1;5 is an important contributor to natural variation in shoot Na+ exclusion.

Original languageEnglish
Article number153029
JournalJournal of Plant Physiology
Volume241
DOIs
Publication statusPublished - Oct 2019

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Keywords

  • Barley
  • Gene expression
  • HKT1;5
  • Naexclusion
  • Salt tolerance

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