Plant Cell Reports

, Volume 33, Issue 2, pp 277–288 | Cite as

A constitutively active form of a durum wheat Na+/H+ antiporter SOS1 confers high salt tolerance to transgenic Arabidopsis

  • Kaouthar Feki
  • Francisco J. Quintero
  • Habib Khoudi
  • Eduardo O. Leidi
  • Khaled Masmoudi
  • Jose M. PardoEmail author
  • Faiçal BriniEmail author
Original Paper


Key message

Expression of a truncated form of wheat TdSOS1 in Arabidopsis exhibited an improved salt tolerance. This finding provides new hints about this protein that can be considered as a salt tolerance determinant.


The SOS signaling pathway has emerged as a key mechanism in preserving the homeostasis of Na+ and K+ under saline conditions. We have recently identified and functionally characterized, by complementation studies in yeast, the gene encoding the durum wheat plasma membrane Na+/H+ antiporter (TdSOS1). To extend these functional studies to the whole plant level, we complemented Arabidopsis sos1-1 mutant with wild-type TdSOS1 or with the hyperactive form TdSOS1∆972 and compared them to the Arabidopsis AtSOS1 protein. The Arabidopsis sos1-1 mutant is hypersensitive to both Na+ and Li+ ions. Compared with sos1-1 mutant transformed with the empty binary vector, seeds from TdSOS1 or TdSOS1∆972 transgenic plants had better germination under salt stress and more robust seedling growth in agar plates as well as in nutritive solution containing Na+ or Li+ salts. The root elongation of TdSOS1∆972 transgenic lines was higher than that of Arabidopsis sos1-1 mutant transformed with TdSOS1 or with the endogenous AtSOS1 gene. Under salt stress, TdSOS1∆972 transgenic lines showed greater water retention capacity and retained low Na+ and high K+ in their shoots and roots. Our data showed that the hyperactive form TdSOS1∆972 conferred a significant ionic stress tolerance to Arabidopsis plants and suggest that selection of hyperactive alleles of the SOS1 transport protein may pave the way for obtaining salt-tolerant crops.


Durum wheat Arabidopsis Na+/H+ antiporter SOS1 Hyperactive form Ionic stress tolerance 



This study was supported by a grant from the Ministry of Higher Education and Scientific Research of Tunisia and the grants A/8077/07 from the Spanish Agency for International Development Cooperation (AECID), BIO2009-08641 from the Ministry of Science and Innovation (MICINN) and BIO2012-36533 from the Ministry of Economy and Competitiveness (MINECO), with the co-finance of the European Regional Development Fund.

Conflict of interest

The authors declare that they have no conflict of interest.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Kaouthar Feki
    • 1
  • Francisco J. Quintero
    • 2
  • Habib Khoudi
    • 1
  • Eduardo O. Leidi
    • 2
  • Khaled Masmoudi
    • 1
    • 3
  • Jose M. Pardo
    • 2
    Email author
  • Faiçal Brini
    • 1
    Email author
  1. 1.Plant Protection and Improvement LaboratoryCentre of Biotechnology of Sfax (CBS)SfaxTunisia
  2. 2.Consejo Superior de Investigaciones CientíficasInstituto de Recursos Naturales y AgrobiologiaSevillaSpain
  3. 3.International Center for Biosaline Agriculture (ICBA)DubaiUnited Arab Emirates

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