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Acta Prataculturae Sinica ›› 2016, Vol. 25 ›› Issue (2): 114-123.DOI: 10.11686/cyxb2015182

• Orginal Article • Previous Articles     Next Articles

Cloning and expression analysis of a high-affinity K+ transporter gene SsHAK2 in Suaeda salsa

DUAN Hui-Rong, WANG Suo-Min*   

  1. State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
  • Received:2015-04-08 Online:2016-02-20 Published:2016-02-20

Abstract: Suaeda salsa, a typical salt-accumulating halophyte, is capable of absorbing K+ with high efficiency, and thus maintains a relatively stable K+ level in cells, and grows well, even in highly saline soil. Members of the KT/HAK/KUP gene family have an important role in K+ uptake in plants. In this study, we cloned SsHAK2 in S. salsa and analyzed the expression patterns of SsHAK2 when the plants were exposed to different concentrations of KCl and NaCl. Results revealed that SsHAK2 coded for 788 amino acid residues and shared a high homology (80%-92%) with the identified members of KT/HAK/KUP family from other plants. Phylogenetic analysis showed that SsHAK2 belonged to a sub-group of the family known as group II, and formed a clade with AtKUP2 of Arabidopsis thaliana, indicating close relationship. SsHAK2 was highly expressed in roots and leaves, and was induced by widely differing K+ concentrations (2.5 and 0.01 mmol/L). Under 2.5 mmol/L K+ conditions, the expression of SsHAK2 in roots and leaves was induced by 25 mmol/L Na+ application. However, in the medium containing 0.01 mmol/L K+, the expression of SsHAK2 in roots was down-regulated by Na+ (25 and 150 mmol/L) application, but up-regulated in leaves. The results therefore indicate that SsHAK2 might mediate K+ uptake and transport in S. salsa, and functioned differently in roots and leaves.