Dissection of the ozone-induced calcium signature

Authors

  • Helen Clayton,

    1. Department of Biological Sciences, Institute of Environmental and Biological Sciences, University of Lancaster, Lancaster LA1 4YQ, UK, and
    Search for more papers by this author
  • Marc R. Knight,

    1. Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
    Search for more papers by this author
  • Heather Knight,

    1. Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
    Search for more papers by this author
  • Martin R. McAinsh,

    1. Department of Biological Sciences, Institute of Environmental and Biological Sciences, University of Lancaster, Lancaster LA1 4YQ, UK, and
    Search for more papers by this author
  • Alistair M. Hetherington

    1. Department of Biological Sciences, Institute of Environmental and Biological Sciences, University of Lancaster, Lancaster LA1 4YQ, UK, and
    2. Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
    Search for more papers by this author

*For correspondence (fax +44 1524 843854; e-mail A.Hetherington@lancaster.ac.uk).

Summary

The cellular responses of plants to numerous extracellular stimuli are mediated by transient elevations in the concentration of cytosolic free calcium ([Ca2+]cyt). We have addressed the question of how cells can use this apparently ubiquitous system to initiate so many specific and appropriate end responses. We show that the pollutant gas ozone elicits a biphasic Ca2+ response in intact Arabidopsis plants and a subsequent increase in expression of the gene encoding the antioxidant defence enzyme glutathione-S-transferase (GST). The second of the two [Ca2+]cyt peaks, but not the first, could be eliminated either by pre-treatment of plants with lanthanum chloride, or by reducing the duration of ozone fumigation. Under these conditions, ozone-inducedGSTexpression was abolished. These data provide a functional dissection of the ozone Ca2+ signalling pathway and indicate that the second ozone-induced [Ca2+]cyt peak provides the necessary information to direct expression ofGST.

Ancillary