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Article Addendum

Biphasic ethylene production during the hypersensitive response in Arabidopsis: A window into defence priming mechanisms?

Luis A.J. Mur, Amanda J. Lloyd, Simona M. Cristescu, Frans J.M. Harren, Michael Hall and Aileen Smith

The hypersensitive response (HR) is a cell death phenomenon associated with localised resistance to pathogens. Biphasic patterns in the generation of H₂O₂, salicylic acid and ethylene have been observed in tobacco during the early stages of the HR. These biphasic models reflect an initial elicitation by pathogen-associated molecular patterns followed by a second phase, induced by pathogen-encoded avirulence gene products. The first phase has been proposed to potentiate the second, to increase the efficacy of plant resistance to disease. This potentiation is comparable to the “priming” of plant defences which is seen when plants display systemic resistance to disease. The events regulating the generation of the biphasic wave, or priming, remains obscure, however recently we demonstrated a key role for nitric oxide in this process in a HR occurring in tobacco. Here we use laser photoacoustic detection to demonstrate that biphasic ethylene production also occurs during a HR occurring in Arabidopsis. We suggest that ethylene emanation during the HR represents a ready means of visualising biphasic events during the HR and that exploiting the genomic resources offered by this model species will facilitate the development of a mechanistic understanding of potentiating / priming processes.

Addendum to: Mur LAJ, Laarhoven LJJ, Harren FJM, Hall MA, Smith AR. Nitric oxide interacts with salicylate to regulate biphasic ethylene production during the hypersensitive response. Plant Physiol 2008; 148:1537-46; PMID: 18799663; DOI: 10.1104/pp.108.124404.

Authors

Luis A.J. Mur Corresponding author: lum@aber.ac.uk

Univerisity of Wales; Aberystwyth, Institute of Biological Sciences; Aberystwyth, Wales UK

Amanda J. Lloyd

Univerisity of Wales; Aberystwyth, Institute of Biological Sciences; Aberystwyth, Wales UK

Simona M. Cristescu

Department of Molecular and Laser Physics; Institute for Molecules and Materials; Radboud University; Nijmegen, The Netherlands

Frans J.M. Harren

Department of Molecular and Laser Physics; Institute for Molecules and Materials; Radboud University; Nijmegen, The Netherlands

Michael Hall

Univerisity of Wales; Aberystwyth, Institute of Biological Sciences; Aberystwyth, Wales UK

Aileen Smith

Univerisity of Wales; Aberystwyth, Institute of Biological Sciences; Aberystwyth, Wales UK