Assessing the Applicability of Singlet Oxygen Photosensitizers in Leaf Studies.
Singlet oxygen ((1) O2 ) is of special interest in plant stress physiology. Studies focused on internal, chlorophyll-mediated production are often complemented with the use of artificial (1) O2 photosensitizers. Here, we report a comparative study on the effects of Rose Bengal (RB), Methylene Violet (MVI), Neutral Red (NR) and Indigo Carmine (IC). These were infiltrated into tobacco leaves at concentrations generating the same fluxes of (1) O2 in solution. Following green light-induced (1) O2 production from these dyes, leaf photosynthesis was characterized by Photosystem (PS) II and PSI electron transport and oxidative damage was monitored as degradation of D1, a PSII core protein. Cellular localizations were identified on the basis of the dyes' fluorescence using confocal laser scanning microscopy. We found that RB and NR were both localized in chloroplasts but the latter had very little effect, probably due to its pH-dependent photosensitizing. Both RB and intracellular, nonplastid MVI decreased PSII electron transport, but the effect of RB was stronger than that of MVI and only RB was capable of damaging the D1 protein. Intercellularly localized IC had no significant effect. Our results also suggest caution when using RB as photosensitizer because it affects PSII electron transport.
Institute of Plant Biology, Biological Research Center, Szeged, Hungary.
László
L
Kovács
Cellular Imaging Laboratory, Biological Research Center, Szeged, Hungary.
Ferhan
F
Ayaydin
Department of Organic and Medicinal Chemistry, University of Pécs, Pécs, Hungary.
Tamás
T
Kálai
Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary.
Júlia
J
Tandori
Institute of Plant Biology, Biological Research Center, Szeged, Hungary.
Péter B
PB
Kós
Institute of Plant Biology, Biological Research Center, Szeged, Hungary.|Institute of Biology, University of Pécs, Pécs, Hungary.
Éva
É
Hideg
D002736:Chloroplasts / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport / Q000187:drug effects; D015394:Molecular Structure; D018384:Oxidative Stress / Q000187:drug effects; D017319:Photosensitizing Agents / Q000737:chemistry* / Q000494:pharmacology*; D018515:Plant Leaves / Q000187:drug effects*; D026082:Singlet Oxygen / Q000737:chemistry* / Q000494:pharmacology*; D014026:Nicotiana / Q000187:drug effects*
D017319:Photosensitizing Agents; D026082:Singlet Oxygen