Email updates

Keep up to date with the latest news and content from BMC Plant Biology and BioMed Central.

Open Access Research article

Dynamic compartment specific changes in glutathione and ascorbate levels in Arabidopsis plants exposed to different light intensities

Elmien Heyneke1, Nora Luschin-Ebengreuth23, Iztok Krajcer3, Volker Wolkinger3, Maria Müller3 and Bernd Zechmann3*

Author Affiliations

1 Department of Lothar Willmitzer, Max-Planck-Institute of Molecular Plant Physiology, Golm, 14476, Germany

2 Institute for Electron Microscopy and Fine Structure Research, Graz University of Technology, Steyrergasse 17, Graz, 8010, Austria

3 Institute of Plant Sciences, University of Graz, Schubertstrasse 51, Graz, 8010, Austria

For all author emails, please log on.

BMC Plant Biology 2013, 13:104  doi:10.1186/1471-2229-13-104

Published: 17 July 2013

Abstract

Background

Excess light conditions induce the generation of reactive oxygen species (ROS) directly in the chloroplasts but also cause an accumulation and production of ROS in peroxisomes, cytosol and vacuoles. Antioxidants such as ascorbate and glutathione occur in all cell compartments where they detoxify ROS. In this study compartment specific changes in antioxidant levels and related enzymes were monitored among Arabidopsis wildtype plants and ascorbate and glutathione deficient mutants (vtc2-1 and pad2-1, respectively) exposed to different light intensities (50, 150 which was considered as control condition, 300, 700 and 1,500 μmol m-2 s-1) for 4 h and 14 d.

Results

The results revealed that wildtype plants reacted to short term exposure to excess light conditions with the accumulation of ascorbate and glutathione in chloroplasts, peroxisomes and the cytosol and an increased activity of catalase in the leaves. Long term exposure led to an accumulation of ascorbate and glutathione mainly in chloroplasts. In wildtype plants an accumulation of ascorbate and hydrogen peroxide (H2O2) could be observed in vacuoles when exposed to high light conditions. The pad2-1 mutant reacted to long term excess light exposure with an accumulation of ascorbate in peroxisomes whereas the vtc2-1 mutant reacted with an accumulation of glutathione in the chloroplasts (relative to the wildtype) and nuclei during long term high light conditions indicating an important role of these antioxidants in these cell compartments for the protection of the mutants against high light stress.

Conclusion

The results obtained in this study demonstrate that the accumulation of ascorbate and glutathione in chloroplasts, peroxisomes and the cytosol is an important reaction of plants to short term high light stress. The accumulation of ascorbate and H2O2 along the tonoplast and in vacuoles during these conditions indicates an important route for H2O2 detoxification under these conditions.

Keywords:
Arabidopsis; Ascorbate; Chloroplast; Glutathione; High light; Reactive oxygen species