NaCl-induced changes in cytosolic free Ca2+ in Arabidopsis thaliana are heterogeneous and modified by external ionic composition

Frances E. Tracy, Matthew Gilliham, Antony N. Dodd, Alex A.R. Webb, Mark Tester*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

111 Scopus citations


Increases in cytosolic free Ca2+ ([Ca2+] cyt) are common to many stress-activated signalling pathways, including the response to saline environments. We have investigated the nature of NaCl-induced [Ca2+]cyt signals in whole Arabidopsis thaliana seedlings using aequorin. We found that NaCl-induced increases in [Ca2+]cyt are heterogeneous and mainly restricted to the root. Both the concentration of NaCl and the composition of the solution bathing the root have profound effects on the magnitude and dynamics of NaCl-induced increases in [Ca2+]cyt. Alteration of external K + concentration caused changes in the temporal and spatial pattern of [Ca2+]cyt increase, providing evidence for Na +-induced Ca2+ influx across the plasma membrane. The effects of various pharmacological agents on NaCl-induced increases in [Ca 2+]cyt indicate that NaCl may induce influx of Ca 2+ through both plasma membrane and intracellular Ca 2+-permeable channels. Analysis of spatiotemporal [Ca 2+]cyt dynamics using photon-counting imaging revealed additional levels of complexity in the [Ca2+]cyt signal that may reflect the oscillatory nature of NaCl-induced changes in single cells.

Original languageEnglish (US)
Pages (from-to)1063-1073
Number of pages11
JournalPlant, Cell and Environment
Issue number8
StatePublished - Aug 2008


  • Aequorin
  • Ca imaging
  • Ca oscillations
  • Ca signalling
  • Membrane potential
  • Osmotic stress
  • Salinity tolerance

ASJC Scopus subject areas

  • Physiology
  • Plant Science

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