NMR 13C-isotopic enrichment experiments to study carbon-partitioning into organic solutes in the red alga Grateloupia doryphora
The red alga Grateloupia doryphora Montagne (Howe) (Cryptonemiales, Halymeniaceae) was used as a model to investigate the effects of changes in seawater salinity on the intracellular low-molecular-weight organic compounds. Carbon-partitioning into major organic solutes was followed by 13C nuclear ma...
| Publié dans: | Plant physiology and biochemistry : PPB. - 1991. - 42(2004), 1 vom: 22. Jan., Seite 21-6 |
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| Auteur principal: | |
| Autres auteurs: | , , |
| Format: | Article |
| Langue: | English |
| Publié: |
2004
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| Accès à la collection: | Plant physiology and biochemistry : PPB |
| Sujets: | Journal Article 2-galactopyranosylglycerol Amino Acids Carbon Isotopes Sulfoxides Lactic Acid 33X04XA5AT Sodium Chloride 451W47IQ8X Sodium Bicarbonate plus... |
| Résumé: | The red alga Grateloupia doryphora Montagne (Howe) (Cryptonemiales, Halymeniaceae) was used as a model to investigate the effects of changes in seawater salinity on the intracellular low-molecular-weight organic compounds. Carbon-partitioning into major organic solutes was followed by 13C nuclear magnetic resonance (NMR) spectroscopy on living algae incubated in NaH13CO3-enriched seawater, and by high resolution 1H and 13C NMR experiments performed on 13C-enriched algal extracts. NMR and high performance liquid chromatography (HPLC) analyses both demonstrated that floridoside level was the most affected by changes in salinity: it rose under the hypersaline treatment and decreased under hyposaline one. Moreover, at low salinity, the high labeling of floridoside (45.3% 13C-enrichment for C1) together with its low concentrations both provided evidence of great increase in the de novo biosynthesis and turnover rate. Our experiments also demonstrated a high incorporation of photosynthetic carbon into amino acids, especially glutamate, under hypoosmotic conditions. On the other hand, isethionic acid and N-methyl-methionine sulfoxide were only partly labeled, which indicates they do not directly derive from carbon photoassimilation. In algae exposed to high salinity, elevated concentrations of floridoside coupled to a low labeling (9.4%) were observed. These results suggest that hyperosmotic conditions stimulated floridoside biosynthesis from endogen storage products rather than from carbon assimilation through photosynthesis |
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| Description: | Date Completed 05.05.2004 Date Revised 30.09.2020 published: Print Citation Status MEDLINE |
| ISSN: | 1873-2690 |