title: Singlet oxygen scavenging activity of tocopherol and plastochromanol in Arabidopsis thaliana: relevance to photooxidative stress.
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.
authors.affiliation: Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, 783 71, Czech Republic.
authors.forename: Anshu
authors.initials: A
authors.lastname: Rastogi
authors.forename: Deepak Kumar
authors.initials: DK
authors.lastname: Yadav
authors.forename: Renata
authors.initials: R
authors.lastname: Szymańska
authors.forename: Jerzy
authors.initials: J
authors.lastname: Kruk
authors.forename: Michaela
authors.initials: M
authors.lastname: Sedlářová
authors.forename: Pavel
authors.initials: P
authors.lastname: Pospíšil
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D002736:Chloroplasts / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D016166:Free Radical Scavengers / Q000378:metabolism*; D019751:Intramolecular Transferases / Q000235:genetics; D018384:Oxidative Stress; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D026082:Singlet Oxygen / Q000378:metabolism*; D019097:Spin Trapping; D024505:Tocopherols / Q000378:metabolism*
chemical_list: D016166:Free Radical Scavengers; D026082:Singlet Oxygen; D019751:Intramolecular Transferases; C103397:tocopherol cyclase; D024505:Tocopherols
keywords: EPR spin-trapping; chloroplast