Singlet oxygen scavenging activity of tocopherol and plastochromanol in Arabidopsis thaliana: relevance to photooxidative stress |
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Authors: | RENATA SZYMAŃSKA JERZY KRUK MICHAELA SEDLÁŘOVÁ PAVEL POSPÍŠIL |
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Institution: | 1. Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, , Kraków, 30‐387 Poland;2. Department of Botany, Faculty of Science, Palacky University, , Olomouc, 783 71 Czech Republic;3. Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacky University, , Olomouc, 783 71 Czech Republic |
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Abstract: | In the present study, singlet oxygen (1O2) scavenging activity of tocopherol and plastochromanol was examined in tocopherol cyclase‐deficient mutant (vte1) of Arabidopsis thaliana lacking both tocopherol and plastochromanol. It is demonstrated here that suppression of tocopherol and plastochromanol synthesis in chloroplasts isolated from vte1 Arabidopsis plants enhanced 1O2 formation under high light illumination as monitored by electron paramagnetic resonance spin‐trapping spectroscopy. The exposure of vte1 Arabidopsis plants to high light resulted in the formation of secondary lipid peroxidation product malondialdehyde as determined by high‐pressure liquid chromatography. Furthermore, it is shown here that the imaging of ultra‐weak photon emission known to reflect oxidation of lipids was unambiguously higher in vte1 Arabidopsis plants. Our results indicate that tocopherol and plastochromanol act as efficient 1O2 scavengers and protect effectively lipids against photooxidative damage in Arabidopsis plants. |
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Keywords: | chloroplast EPR spin‐trapping |
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