Apoplastic Ascorbate Does not Prevent the Oxidation of Fluorescent Amphiphilic Dyes by Ambient and Elevated Concentrations of Ozone in Leaves
スポンサーリンク
概要
- 論文の詳細を見る
Cut leaves of spinach were infiltrated with soultions containing oxidation-sensitive fluorescent dyes. Excess solution was removed from the intercellular space by centrifugation. Fluorescence of the dyes D494 and D283 started to decrease immediately after the onset of fumigation with ozone at concentrations similar to or not much higher than ambient concentrations in air on sunny days. Only part of ozone entering the leaves was intercepted by the dye. The major part was degraded by unspecified reactions. Photosynthesis was not inhibited while the introduced dye was oxidized by ozone, showing that open stomata facilitated gas exchange after the introduction of dye into the leaf interior. Feeding of ascorbate to the leaves via the petiole failed to affect the ozone-dependent decrease in fluorescence imission from the dye. Likewise, infiltration of leaves by solutions containing dye and 10 mM ascorbate did not produce significant protection of the dye against oxidation by ozone. However, such protection was observed in vitro, when solutions of dye and ascorbate were bubbled with air containing ozone. Although there is little doubt that apoplastic ascobate occupies a central position in the antioxidative defense of leaf tissue, we are surprised to find that it is much less effective than expected to decrease the oxidation of fluorescent lipophilic probes which had been introduced into the leaf interior. The data suggest that ascorbate is not a primary reductant of ozone in the apoplast. With a microscope-mounted CCD-camera connected to the gas exchange equipment we obtained spatial information on the fluorescence signal and present first results on an heterogeneous distribution of ozone action.
- 日本植物生理学会の論文
著者
-
Heber Ulrich
Julius-von-sachs-institute Fur Biowissenschaften Universitat Wurzburg
-
Heber Ulrich
Julius-von-sachs Institut Fiir Bio Wissenschaften Universitat Wtirzburg
-
Jakob Burkhard
Julius-von-Sachs Institut fiir Bio wissenschaften, Universitat Wtirzburg
-
Jakob Burkhard
Julius-von-sachs-institut Fur Biowissenschaften Universitat Wurzburg
関連論文
- DETECTION OF PHOTOOXIDATIVE STRESS BY MONODEHYDROASCORBATE IN LEAVES
- Photoproduction and Detoxification of Hydroxyl radicals in Chloroplasts and Leaves and Relation to Photoinactivation of Photosystems I and II
- Maximum H^+/hv_ Stoichiometry of Proton Transport during Cyclic Electron Flow in Intact Chloroplasts Is at Least Two, but Probably Higher than Two : MEMBRANES AND BIOENERGETICS
- Coupling Ratios H^+/e=3 versus H^+/e=2 in Chloroplasts and Quantum Requirements of Net Oxygen Exchange during the Reduction of Nitrite, Ferricyanide or Methylviologen : MEMBRANES AND BIOENERGETICS
- Photooxidative Damage in Young Leaves of Declining Grapevine: Does It Result from a New and Possibly Viroid-Related Disease?
- Fast Cytoplasmic pH Regulation in Acid-Stressed Leaves : ENVIRONMENTAL AND STRESS RESPONSES : MEMBRANES AND BIOENERGETICS
- Apoplastic Ascorbate Does not Prevent the Oxidation of Fluorescent Amphiphilic Dyes by Ambient and Elevated Concentrations of Ozone in Leaves
- Bioenergetics of Carbon Assimilation in Intact Chloroplasts : Coupling of Proton to Electron Transport at the Ratio H^+/e=3 Is Incompatible with H^+/ATP=3 in ATP Synthesis : MEMBRANES AND BIOENERGETICS