| Autor: |
G. Grunwaldt, Rudolf Ehwald, W. Pietzsch, H. Göring |
| Rok vydání: |
1979 |
| Předmět: |
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| Zdroj: |
Biochemie und Physiologie der Pflanzen. 174:831-837 |
| ISSN: |
0015-3796 |
| Popis: |
Summary Using the possibility of selective killing the rhizodermis by means of osmotic shock further evidence is produced for the hypothesis of a restricted diffusion into the free space of a higher plants root cortex and of a special role of the rhizodermis in uptake processes of plant roots. Osmotic shock causes a strong decrease of phosphate uptake from low-concentrated solutions due to an osmotic rupture of rhizodermal cells. Phosphate uptake from higher concentrated solutions is only slightly influenced. It is concluded that phosphate uptake from low-concentrated solutions takes place at the shock-sensitive tissue surface only whereas higher concentrations permit the diffusion of the solute into the free space and, therefore, allow the shock-insensitive cortical cells to take part in the uptake process. This view is supported by a second line of evidence coming from the investigation of the time course and the temperature dependence of phosphate uptake and from measurements of the trans-membrane potential difference. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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