Plant Molecular Biology

, Volume 54, Issue 6, pp 881–893

Tissue-specific expression and functional complementation of a yeastpotassium-uptake mutant by a salt-induced ice plant gene mcSKD1

  • Yingtzy Jou
  • Pin Chou
  • Mengchun He
  • Yuhui Hung
  • Hungchen Emilie Yen
Article

DOI: 10.1007/s11103-004-0335-7

Cite this article as:
Jou, Y., Chou, P., He, M. et al. Plant Mol Biol (2004) 54: 881. doi:10.1007/s11103-004-0335-7

Abstract

A full-length salt-induced transcript homologous to SKD1 (suppressor of K+ transport growth defect) of the AAA (ATPase associated with a variety of cellular activities)-type ATPase family has been identified from the halophyte Mesembryanthemum crystallinum (ice plant). The expression of mcSKD1 was induced by 200 mM NaCl or higher in cultured ice plant cells. When cultured ice plant cells were grown in a high K+ (42.6 mM) medium, the level of mcSKD1 expression decreased. At the whole plant level, constitutive expression of mcSKD1 was observed in roots, stems, leaves and floral organs. Addition of 400 mM NaCl increased the transcript level in roots and stems. The expression of atSKD1, a homologue gene in Arabidopsis, was down regulated by salt stress. Under salt stress, mcSKD1 was preferentially expressed in the outer cortex of roots and stems and in the epidermal bladder cells of leaves. The mcSKD1 transcript was constitutively expressed in placenta and integuments of the developing floral buds. Expression of the full-length or C-terminal deletion of mcSKD1 was able to complement the K+ uptake-defect phenotype in mutant Saccharomyces cerevisiae, which is defective in high- and low-affinity K+ uptake. Deletion of the N-terminal coiled-coil motif of mcSKD1, a structure required for membrane association, resulted in greatly reduced K+ transport. Expression of mcSKD1 also increased the salt-tolerant ability of yeast mutants and either N- or C-terminal deletion decreased the efficiency. The physiological relevancies of mcSKD1 for K+ uptake under high salinity environments are discussed.

: AAA-type ATPasehalophyteice plantsalt-induced gene mcSKD1yeast complementation

Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • Yingtzy Jou
    • 1
  • Pin Chou
    • 1
  • Mengchun He
    • 1
  • Yuhui Hung
    • 1
  • Hungchen Emilie Yen
    • 1
  1. 1.Department of Life SciencesNational Chung-Hsing UniversityTaiwan