Vacuolar chloride transport in Mesembryanthemum crystallinum L. measured using the fluorescent dye lucigenin.
To study vacuolar chloride (Cl(-)) transport in the halophilic plant Mesembryanthemum crystallinum L., Cl(-) uptake into isolated tonoplast vesicles was measured using the Cl(-)-sensitive fluorescent dye lucigenin (N,N'-dimethyl-9,9'-bisacridinium dinitrate). Lucigenin was used at excitati...
| 主要な著者: | , |
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| フォーマット: | Journal article |
| 言語: | English |
| 出版事項: |
2000
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| _version_ | 1826283924334051328 |
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| author | Wissing, F Smith, J |
| author_facet | Wissing, F Smith, J |
| author_sort | Wissing, F |
| collection | OXFORD |
| description | To study vacuolar chloride (Cl(-)) transport in the halophilic plant Mesembryanthemum crystallinum L., Cl(-) uptake into isolated tonoplast vesicles was measured using the Cl(-)-sensitive fluorescent dye lucigenin (N,N'-dimethyl-9,9'-bisacridinium dinitrate). Lucigenin was used at excitation and emission wavelengths of 433 nm and 506 nm, respectively, and showed a high sensitivity towards Cl(-), with a Stern-Volmer constant of 173 m(-1) in standard assay buffer. While lucigenin fluorescence was strongly quenched by all halides, it was only weakly quenched, if at all, by other anions. However, the fluorescence intensity and Cl(-)-sensitivity of lucigenin was shown to be strongly affected by alkaline pH and was dependent on the conjugate base used as the buffering ion. Chloride transport into tonoplast vesicles of M. crystallinum loaded with 10 mm lucigenin showed saturation-type kinetics with an apparent K(m) of 17.2 mm and a V(max) of 4.8 mm min(-1). Vacuolar Cl(-) transport was not affected by sulfate, malate, or nitrate. In the presence of 250 microm p-chloromercuribenzene sulfonate, a known anion-transport inhibitor, vacuolar Cl(-) transport was actually significantly increased by 24%. To determine absolute fluxes of Cl(-) using this method, the average surface to volume ratio of the tonoplast vesicles was measured by electron microscopy to be 1.13 x 10(7) m(-1). After correcting for a 4.4-fold lower apparent Stern-Volmer constant for intravesicular lucigenin, a maximum rate of Cl(-) transport of 31 nmol m(-2) sec(-1) was calculated, in good agreement with values obtained for the plant vacuolar membrane using other techniques. |
| first_indexed | 2024-03-07T01:06:08Z |
| format | Journal article |
| id | oxford-uuid:8b6938a4-0cab-4d70-8b84-db0fa5188d84 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T01:06:08Z |
| publishDate | 2000 |
| record_format | dspace |
| spelling | oxford-uuid:8b6938a4-0cab-4d70-8b84-db0fa5188d842022-03-26T22:37:53ZVacuolar chloride transport in Mesembryanthemum crystallinum L. measured using the fluorescent dye lucigenin.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:8b6938a4-0cab-4d70-8b84-db0fa5188d84EnglishSymplectic Elements at Oxford2000Wissing, FSmith, JTo study vacuolar chloride (Cl(-)) transport in the halophilic plant Mesembryanthemum crystallinum L., Cl(-) uptake into isolated tonoplast vesicles was measured using the Cl(-)-sensitive fluorescent dye lucigenin (N,N'-dimethyl-9,9'-bisacridinium dinitrate). Lucigenin was used at excitation and emission wavelengths of 433 nm and 506 nm, respectively, and showed a high sensitivity towards Cl(-), with a Stern-Volmer constant of 173 m(-1) in standard assay buffer. While lucigenin fluorescence was strongly quenched by all halides, it was only weakly quenched, if at all, by other anions. However, the fluorescence intensity and Cl(-)-sensitivity of lucigenin was shown to be strongly affected by alkaline pH and was dependent on the conjugate base used as the buffering ion. Chloride transport into tonoplast vesicles of M. crystallinum loaded with 10 mm lucigenin showed saturation-type kinetics with an apparent K(m) of 17.2 mm and a V(max) of 4.8 mm min(-1). Vacuolar Cl(-) transport was not affected by sulfate, malate, or nitrate. In the presence of 250 microm p-chloromercuribenzene sulfonate, a known anion-transport inhibitor, vacuolar Cl(-) transport was actually significantly increased by 24%. To determine absolute fluxes of Cl(-) using this method, the average surface to volume ratio of the tonoplast vesicles was measured by electron microscopy to be 1.13 x 10(7) m(-1). After correcting for a 4.4-fold lower apparent Stern-Volmer constant for intravesicular lucigenin, a maximum rate of Cl(-) transport of 31 nmol m(-2) sec(-1) was calculated, in good agreement with values obtained for the plant vacuolar membrane using other techniques. |
| spellingShingle | Wissing, F Smith, J Vacuolar chloride transport in Mesembryanthemum crystallinum L. measured using the fluorescent dye lucigenin. |
| title | Vacuolar chloride transport in Mesembryanthemum crystallinum L. measured using the fluorescent dye lucigenin. |
| title_full | Vacuolar chloride transport in Mesembryanthemum crystallinum L. measured using the fluorescent dye lucigenin. |
| title_fullStr | Vacuolar chloride transport in Mesembryanthemum crystallinum L. measured using the fluorescent dye lucigenin. |
| title_full_unstemmed | Vacuolar chloride transport in Mesembryanthemum crystallinum L. measured using the fluorescent dye lucigenin. |
| title_short | Vacuolar chloride transport in Mesembryanthemum crystallinum L. measured using the fluorescent dye lucigenin. |
| title_sort | vacuolar chloride transport in mesembryanthemum crystallinum l measured using the fluorescent dye lucigenin |
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