Root plasma membrane transporters controlling K+/Na+ homeostasis in salt-stressed barley

Zhonghua Chen, Igor I. Pottosin, Tracey A. Cuin, Anja T. Fuglsang, Mark Tester, Deepa Jha, Isaac Zepeda-Jazo, Meixue Zhou, Michael G. Palmgren, Ian A. Newman, Sergey Shabala*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

340 Scopus citations

Abstract

Plant salinity tolerance is a polygenic trait with contributions from genetic, developmental, and physiological interactions, in addition to interactions between the plant and its environment. In this study, we show that in salt-tolerant genotypes of barley (Hordeum vulgare), multiple mechanisms are well combined to withstand saline conditions. These mechanisms include: (1) better control of membrane voltage so retaining a more negative membrane potential; (2) intrinsically higher H+ pump activity; (3) better ability of root cells to pump Na+ from the cytosol to the external medium; and (4) higher sensitivity to supplemental Ca2+. At the same time, no significant difference was found between contrasting cultivars in their unidirectional 22Na+ influx or in the density and voltage dependence of depolarization-activated outward-rectifying K+ channels. Overall, our results are consistent with the idea of the cytosolic K+-to-Na+ ratio being a key determinant of plant salinity tolerance, and suggest multiple pathways of controlling that important feature in salt-tolerant plants.

Original languageEnglish (US)
Pages (from-to)1714-1725
Number of pages12
JournalPlant physiology
Volume145
Issue number4
DOIs
StatePublished - Dec 1 2007

ASJC Scopus subject areas

  • Physiology
  • Genetics
  • Plant Science

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