Regulation of cytoplasmic pH under extreme acid conditions in suspension cultured cells of Catharanthus roseus: A possible role of inorganic phosphate
Changes in cytoplasmic pH of suspension-cultured cells of Catharanthus roseus under extreme acid conditions were measured with the pH-dependent fluorescence dye; 2′,7′-bis-(2-carboxyethyl)-5 (and-6) carboxyfluorescein (-acetoxymethylester) (BCECF). When cells were treated with 1 mM HC1 (pH 3 solutio...
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Published in | Plant and cell physiology Vol. 41; no. 4; pp. 424 - 431 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Japan
Plant and Cell Physiology
01.04.2000
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Subjects | |
Online Access | Get full text |
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Summary: | Changes in cytoplasmic pH of suspension-cultured cells of Catharanthus roseus under extreme acid conditions were measured with the pH-dependent fluorescence dye; 2′,7′-bis-(2-carboxyethyl)-5 (and-6) carboxyfluorescein (-acetoxymethylester) (BCECF). When cells were treated with 1 mM HC1 (pH 3 solution), the cytoplasmic pH first decreased then returned to the original level. Treatment with 10 mM HC1 (pH 2 solution) acidified the cytoplasm to a greater extent, and the acidification continued at a constant level throughout the measurement. Treatment with a pH 2 solution resulted in a gradual decrease of the malate content, indicating the operation of biochemical pH regulation mechanism. The pH 2 treatment also caused a sudden decrease of the intracellular level of Pi. The cellular content of total phosphorus did not change during the acidification. The Pi was converted to the organic phosphate form. The ATP level was not increased by the pH 2 treatment, but slightly decreased. The role of Pi, which might be functioning as a regulatory factor of cytoplasmic pH, a non-competitive inhibitor of the H+-pumps of both the plasma membrane and tonoplast is discussed. |
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Bibliography: | 2000006435 F60 ark:/67375/HXZ-XZ3NPST6-5 istex:A8B0BCA4A77AD322A5C575FE4774E4C59A4DE6EC ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0032-0781 1471-9053 |
DOI: | 10.1093/pcp/41.4.424 |