Supportive role of the Na ⁺ transporter CmHKT1;1 from Cucumis melo in transgenic Arabidopsis salt tolerance through improved K ⁺ /Na ⁺ balance.

Publisher: Kluwer Academic Country of Publication: Netherlands NLM ID: 9106343 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1573-5028 (Electronic) Linking ISSN: 01674412 NLM ISO Abbreviation: Plant Mol Biol Subsets: MEDLINE

Publication: Dordrecht : Kluwer Academic
Original Publication: The Hague ; Boston : Martinus Nijhoff/Dr. W. Junk, 1981-

Arabidopsis/*metabolism ; Cucumis melo/*metabolism ; Membrane Transport Proteins/*metabolism ; Plants, Genetically Modified/*metabolism ; Potassium/*metabolism ; Sodium/*metabolism; Arabidopsis/genetics ; Cation Transport Proteins/genetics ; Cation Transport Proteins/metabolism ; Chlorophyll/analysis ; Cloning, Molecular ; Cucumis melo/genetics ; Gene Expression Regulation, Plant ; Membrane Transport Proteins/genetics ; Plant Leaves/metabolism ; Plant Proteins/genetics ; Plant Roots/metabolism ; Plant Shoots/genetics ; Saccharomyces cerevisiae/genetics ; Salt Tolerance ; Seedlings/genetics ; Seedlings/metabolism ; Sequence Alignment ; Sequence Analysis, Protein ; Sodium Chloride/metabolism ; Stress, Physiological/genetics ; Stress, Physiological/physiology ; Symporters/genetics ; Symporters/metabolism ; Nicotiana/genetics ; Nicotiana/metabolism

Key Message: CmHKT1;1 selectively exports Na ⁺ from plant cells. Upon NaCl stress, its expression increased in a salt-tolerant melon cultivar. Overexpression of CmHKT1;1 increased transgenic Arabidopsis salt tolerance through improved K ⁺ /Na ⁺ balance. High-affinity K ⁺ transporters (HKTs) are thought to be involved in reducing Na ⁺ in plant shoots under salt stress and modulating salt tolerance, but their function in a moderately salt-tolerant species of melon (Cucumis melo L.) remains unclear. In this study, a Na ⁺ transporter gene, CmHKT1;1 (GenBank accession number: MK986658), was isolated from melons based on genome data. The transcript of CmHKT1;1 was relatively more abundant in roots than in stems or leaves from melon seedlings. The tobacco transient expression system showed that CmHKT1;1 was plasma-membrane localized. Upon salt stress, CmHKT1;1 expression was more strongly upregulated in a salt-tolerant melon cultivar, 'Bingxuecui' (BXC) compared with a salt-sensitive cultivar, 'Yulu' (YL). Electrophysiological evidence demonstrated that CmHKT1;1 only transported Na ⁺ , rather than K ⁺ , when expressed in Xenopus laevis oocytes. Overexpression of CmHKT1;1 increased salt sensitivity in Saccharomyces cerevisiae and salt tolerance in Arabidopsis thaliana. Under NaCl treatments, transgenic Arabidopsis plants accumulated significantly lower concentrations of Na ⁺ in shoots than wild type plants and showed a better K ⁺ /Na ⁺ balance, leading to better F v /F m , root length, biomass, and enhanced plant growth. The CmHKT1;1 gene may serve as a useful candidate for improving crop salt tolerance.

31372079 National Natural Science Foundation of China

Keywords: CmHKT1;1; Electrophysiology; Melon (Cucumis melo L); Na+ transporter; Salt tolerance; Transgenic Arabidopsis plants

0 (Cation Transport Proteins)
0 (HKT1 protein, plant)
0 (Membrane Transport Proteins)
0 (Plant Proteins)
0 (Symporters)
1406-65-1 (Chlorophyll)
451W47IQ8X (Sodium Chloride)
9NEZ333N27 (Sodium)
RWP5GA015D (Potassium)

Date Created: 20200515 Date Completed: 20200706 Latest Revision: 20231213

20231215

10.1007/s11103-020-01011-0

32405802