Planta

, Volume 214, Issue 1, pp 126–134

Activation of the oxidative burst in aequorin-transformed Nicotiana tabacum cells is mediated by protein kinase- and anion channel-dependent release of Ca2+ from internal stores

  • Stephen G. Cessna
  • Philip S. Low
Original Article

DOI: 10.1007/s004250100596

Cite this article as:
Cessna, S.G. & Low, P.S. Planta (2001) 214: 126. doi:10.1007/s004250100596
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Abstract.

The source of Ca2+ involved in transducing an oxidative-burst defense signal was examined in aequorin-transformed tobacco (Nicotiana tabacum L.) cells using modulators of Ca2+ entry. Treatments that either increased or decreased the influx of Ca2+ from external stores were found to have little effect on the magnitude or kinetics of an osmotically stimulated oxidative burst. In contrast, treatments that reduced the discharge of Ca2+ from internal stores inhibited dilution-activated H2O2 production. Curiously, most of the modulators commonly employed in animal studies as internal Ca2+-release inhibitors were neither effective in blocking discharge of intracellular Ca2+ nor in preventing the oxidative burst. When three different biochemical elicitors of the oxidative burst were similarly examined, both the H2O2 production and Ca2+ fluxes stimulated were found to be sensitive to modulators of internal Ca2+ release, but neither was impacted by alterations in externally derived Ca2+ influx. We hypothesize, therefore, that the oxidative burst does not depend on the influx of external Ca2+, but instead may generally be mediated by the release of internal Ca2+ in a manner that depends on the proper function of kinases and anion channels. These Ca2+ pulses trigger downstream signaling events that include the activation of Ca2+-regulated protein kinases, which are required for stimulation of the oxidative burst.

Calcium Nicotiana (oxidative burst) Oxidative burst Signal transduction 

Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  • Stephen G. Cessna
    • 1
  • Philip S. Low
    • 1
  1. 1.Biochemistry and Molecular Biology Program and the Department of Chemistry, Purdue University, 1393 Brown Bldg., W. Lafayette, IN 47904, USA
  2. 2.Present address: Eastern Mennonite University 1200 Park Rd., Harrisonburg, VA 22802, USA

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