Anoxia tolerance in the aquatic monocot Potamogeton pectinatus absence of oxygen stimulates elongation in association with an unusually large pasteur effect
Elongation by stems of overwintered tubers of Potamogeton pectinatus (L.) is strongly promoted over several days by oxygen-free conditions. Characteristics of the respiration underpinning this unusual response were examined. Anaerobic plants produced ethanol and CO(2) in approximately equimolar amou...
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 51(2000), 349 vom: 15. Aug., Seite 1413-22 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , |
| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2000
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Carbon Dioxide 142M471B3J Lactic Acid 33X04XA5AT Ethanol 3K9958V90M Sucrose 57-50-1 mehr... |
| Zusammenfassung: | Elongation by stems of overwintered tubers of Potamogeton pectinatus (L.) is strongly promoted over several days by oxygen-free conditions. Characteristics of the respiration underpinning this unusual response were examined. Anaerobic plants produced ethanol and CO(2) in approximately equimolar amounts, indicating that glycolysis coupled to alcoholic fermentation was the principal CO(2)-producing respiratory pathway. Rates of CO(2) evolution by aerobic and anaerobic whole plants (shoot and tuber) were similar, suggesting a rate of glycolysis three times that of aerobic plants, i.e. a strong Pasteur effect. In the shoot alone, anaerobic CO(2) production was twice the aerobic rate indicating a 6-fold increase in the rate of glycolysis in this tissue. Anoxic stems contained more sucrose at a stronger concentration than slower-growing aerobic stems or anaerobic leaves, demonstrating that sugar supply to the site of most rapid growth exceeded demand in the absence of oxygen. Concentrations of potentially toxic acetaldehyde in the external medium were small (approximately 0.2 mol m(-3)) during anoxia and on return to aerated conditions. Lactic acid was undetectable under anaerobic conditions and in vivo (31)P-NMR analysis of shoots revealed a cytoplasmic acidification of only </=0.2 pH units. In contrast, shoots of Pisum sativum, an anoxia-intolerant species, showed much stronger cytoplasmic acidification when transferred to oxygen-free conditions |
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| Beschreibung: | Date Completed 20.09.2000 Date Revised 21.11.2013 published: Print Citation Status MEDLINE |
| ISSN: | 1460-2431 |