Hydrogen peroxide contributes to the ultraviolet-B (280-315 nm) induced oxidative stress of plant leaves through multiple pathways.
Solar UV-B (280-315 nm) radiation is a developmental signal in plants but may also cause oxidative stress when combined with other environmental factors. Using computer modeling and in solution experiments we show that UV-B is capable of photosensitizing hydroxyl radical production from hydrogen peroxide. We present evidence that the oxidative effect of UV-B in leaves is at least twofold: (i) it increases cellular hydrogen peroxide concentrations, to a larger extent in pyridoxine antioxidant mutant pdx1.3-1 Arabidopsis and; (ii) is capable of a partial photo-conversion of both 'natural' and 'extra' hydrogen peroxide to hydroxyl radicals. As stress conditions other than UV can increase cellular hydrogen peroxide levels, synergistic deleterious effects of various stresses may be expected already under ambient solar UV-B.
Institute of Biology, University of Pécs, Pécs, Hungary; Institute of Plant Biology, Biological Research Centre, Szeged, Hungary.
Gyula
G
Czégény
Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden.
Min
M
Wu
Institute of Biophysics, Biological Research Centre, Szeged, Hungary.
András
A
Dér
Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden.
Leif A
LA
Eriksson
Örebro Life Science Centre, School of Science & Technology, Örebro University, Örebro, Sweden.
Åke
Å
Strid
Institute of Biology, University of Pécs, Pécs, Hungary. Electronic address: ehideg@gamma.ttk.pte.hu.
Éva
É
Hideg
D017360:Arabidopsis / Q000378:metabolism* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D019759:Carbon-Nitrogen Lyases; D006861:Hydrogen Peroxide / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D019884:Nitrogenous Group Transferases / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress; D018515:Plant Leaves / Q000378:metabolism* / Q000528:radiation effects; D014466:Ultraviolet Rays
D029681:Arabidopsis Proteins; D006861:Hydrogen Peroxide; D019884:Nitrogenous Group Transferases; D019759:Carbon-Nitrogen Lyases; C505161:At2g38230 protein, Arabidopsis
Arabidopsis; Computer modeling; Hydrogen peroxide; Hydroxyl radical; Leaf; Oxygen radicals; Photosynthesis; Plant; Terephthalic acid; UV photobiology