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Using spontaneous photon emission to image lipid oxidation patterns in plant tissues
Article first published online: 1 JUL 2011
© 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd
The Plant Journal
Volume 67, Issue 6, pages 1103–1115, September 2011
How to Cite
Birtic, S., Ksas, B., Genty, B., Mueller, M. J., Triantaphylidès, C. and Havaux, M. (2011), Using spontaneous photon emission to image lipid oxidation patterns in plant tissues. The Plant Journal, 67: 1103–1115. doi: 10.1111/j.1365-313X.2011.04646.x
- Issue published online: 5 SEP 2011
- Article first published online: 1 JUL 2011
- Accepted manuscript online: 19 MAY 2011 10:47AM EST
- Received 7 April 2011; revised 15 May 2011; accepted 18 May 2011; published online 1 July 2011.
- lipid peroxidation;
- spontaneous photon emission;
- oxidative stress
Plants, like almost all living organisms, spontaneously emit photons of visible light. We used a highly sensitive, low-noise cooled charge coupled device camera to image spontaneous photon emission (autoluminescence) of plants. Oxidative stress and wounding induced a long-lasting enhancement of plant autoluminescence, the origin of which is investigated here. This long-lived phenomenon can be distinguished from the short-lived chlorophyll luminescence resulting from charge recombinations within the photosystems by pre-adapting the plant to darkness for about 2 h. Lipids in solvent were found to emit a persistent luminescence after oxidation in vitro, which exhibited the same time and temperature dependence as plant autoluminescence. Other biological molecules, such as DNA or proteins, either did not produce measurable light upon oxidation or they did produce a chemiluminescence that decayed rapidly, which excludes their significant contribution to the in vivo light emission signal. Selective manipulation of the lipid oxidation levels in Arabidopsis mutants affected in lipid hydroperoxide metabolism revealed a causal link between leaf autoluminescence and lipid oxidation. Addition of chlorophyll to oxidized lipids enhanced light emission. Both oxidized lipids and plants predominantly emit light at wavelengths higher than 600 nm; the emission spectrum of plant autoluminescence was shifted towards even higher wavelengths, a phenomenon ascribable to chlorophyll molecules acting as luminescence enhancers in vivo. Taken together, the presented results show that spontaneous photon emission imaged in plants mainly emanates from oxidized lipids. Imaging of this signal thus provides a simple and sensitive non-invasive method to selectively visualize and map patterns of lipid oxidation in plants.