title: Effects of an oxidizing agent (hydrogen peroxide) on the glutathione system in epidermal cells of Allium cepa L. investigated by histochemical staining.
abstract: The glutathione system in epidermal cells of Allium cepa L. was measured by a quantitative image analysis method, using histochemical staining by monochlorobimane. Blockage of thiol groups with N-ethylmaleimide decreased fluorescence to a small rest fluorescence of maximum 5%. Pre-treatment with dithiothreitol increased fluorescence yield in all cells compared to the monochlorobimane treatment alone. These results correspond to the blockage or the reduction of the total pool of glutathione in the cells. After treatment with N-ethylmaleimide and subsequent incubation with dithiothreitol followed by labelling with bimane a low fluorescence yield was observed which correspond to the proportion of GSSG. Specimens that were incubated in H2O2 prior to the treatments described above exhibited a decrease in total glutathione and in reduced glutathione and an increase in the proportion of GSSG compared to the control.
authors.affiliation: Institute of Plant Physiology, University of Graz, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Müller
authors.forename: M
authors.initials: M
authors.lastname: Tausz
authors.forename: A
authors.initials: A
authors.lastname: Wonisch
authors.forename: D
authors.initials: D
authors.lastname: Grill
mesh_terms: D000490:Allium / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism*; D006651:Histocytochemistry; D006861:Hydrogen Peroxide / Q000633:toxicity*; D007091:Image Processing, Computer-Assisted; D016877:Oxidants / Q000633:toxicity*; D011720:Pyrazoles; D013194:Staining and Labeling
chemical_list: D016877:Oxidants; D011720:Pyrazoles; C059597:monochlorobimane; D006861:Hydrogen Peroxide; D005978:Glutathione