Dissection of the ozone-induced calcium signature.

Clayton, Helen and Knight, Marc R. and Knight, Heather and McAinsh, Martin and Hetherington, Alistair M. (1999) Dissection of the ozone-induced calcium signature. Plant Journal, 17 (5). pp. 575-579. ISSN 0960-7412

Abstract

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 of GST.