Respiratory carbon metabolism in the high mountain plant species Ranunculus glacialis
Very little is known about the primary carbon metabolism of the high mountain plant Ranunculus glacialis. It is a species with C3 photosynthesis, but with exceptionally high malate content in its leaves, the biological significance of which remains unclear. 13C/12C-isotope ratio mass spectrometry (I...
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 57(2006), 14 vom: 08., Seite 3837-45 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , |
| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2006
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Malates Carbon Dioxide 142M471B3J Carbon 7440-44-0 malic acid 817L1N4CKP |
| Zusammenfassung: | Very little is known about the primary carbon metabolism of the high mountain plant Ranunculus glacialis. It is a species with C3 photosynthesis, but with exceptionally high malate content in its leaves, the biological significance of which remains unclear. 13C/12C-isotope ratio mass spectrometry (IRMS) and 13C-nuclear magnetic resonance (NMR) labelling were used to study the carbon metabolism of R. glacialis, paying special attention to respiration. Although leaf dark respiration was high, the temperature response had a Q10 of 2, and the respiratory quotient (CO2 produced divided by O2 consumed) was nearly 1, indicating that the respiratory pool is comprised of carbohydrates. Malate, which may be a large carbon substrate, was not respired. However, when CO2 fixed by photosynthesis was labelled, little labelling of the CO2 subsequently respired in the dark was detected, indicating that: (i) most of the carbon recently assimilated during photosynthesis is not respired in the dark; and (ii) the carbon used for respiration originates from (unlabelled) reserves. This is the first demonstration of such a low metabolic coupling of assimilated and respired carbon in leaves. The biological significance of the uncoupling between assimilation and respiration is discussed |
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| Beschreibung: | Date Completed 27.02.2007 Date Revised 24.11.2016 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1460-2431 |