| Autor: |
Renata Rybová, Karel Janáček, Marie Kleinová-Slavíková |
| Rok vydání: |
1980 |
| Předmět: |
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| Zdroj: |
Zeitschrift für Pflanzenphysiologie. 97:5-12 |
| ISSN: |
0044-328X |
| DOI: |
10.1016/s0044-328x(80)80060-2 |
| Popis: |
Summary Light brings about a considerable alkalization (over pH 9) in suspensions of the alga Hydrodictyon reticulatum . The exponential time course of pH at later stages of the pH change shows that the process then obeys the simple differential equation dpH/dt = k(pH final pH). The dependence of the apparent light-induced proton inflow measured using pH-stat equipment differs considerably from that inferred from pH time courses under the assumption of an unbuffered medium. The process of alkalization is reversed in the -dark and can be completely inhibited by DCMU (3'-(3,4-dichlorphenyl)-1',1'-dimethylurea). Since the same is true about the unidirectional influx of chloride ions, it is postulated that the uptake of protons (or extrusion of hydroxyl ions) in the light is coupled with an inflow of Cl. When the alkalization system is not energized (in the dark or in the presence of DCMU) the steady distribution of protons appears to be far from the Gibbs-Donnan equilibrium, this suggesting that protons are transported predominantly in an undissociated, uncharged form. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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