JXB Advance Access originally published online on July 24, 2008
Journal of Experimental Botany 2008 59(12):3407-3414; doi:10.1093/jxb/ern189
© 2008 The Author(s).
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RESEARCH PAPER |
Real-time electrochemical detection of extracellular nitric oxide in tobacco cells exposed to cryptogein, an elicitor of defence responses


1UMR INRA 1088/CNRS 5184/Université de Bourgogne, Plante-Microbe-Environnement, BP 86510, 17 rue Sully, 21000 Dijon, France
2CNRS, UMR 8151, Ecole Nationale Supérieure de Chimie de Paris, INSERM, U640, University Paris Descartes. ENSCP, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05, France
To whom correspondence should be addressed. E-mail: fethi-bedioui{at}enscp.fr
To whom correspondence should be addressed. E-mail: wendehen{at}dijon.inra.fr
It was previously reported that cryptogein, an elicitor of defence responses, induces an intracellular production of nitric oxide (NO) in tobacco. Here, the possibility was explored that cryptogein might also trigger an increase of NO extracellular content through two distinct approaches, an indirect method using the NO probe 4,5-diaminofluorescein (DAF-2) and an electrochemical method involving a chemically modified microelectrode probing free NO in biological media. While the chemical nature of DAF-2-reactive compound(s) is still uncertain, the electrochemical modified microelectrodes provide real-time evidence that cryptogein induces an increase of extracellular NO. Direct measurement of free extracellular NO might offer important new insights into its role in plants challenged by biotic stresses.
Key words: Diaminofluorescein, diethylamine NONOate, electrochemical sensor, nitric oxide, plant defence responses
* These authors contributed equally to this work.
Received 22 April 2008; Accepted 25 June 2008