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| Titel |
Biochemical hydrogen isotope fractionation during biosynthesis in higher plants reflects carbon metabolism of the plant |
| VerfasserIn |
Marc-André Cormier, Ansgar Kahmen |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250111641
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| Publikation (Nr.) |
 EGU/EGU2015-11781.pdf |
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| Zusammenfassung |
| Compound-specific isotope analyses of plant material are frequently applied to understand
the response of plants to the environmental changes. As it is generally assume that the main
factors controlling δ2H values in plants are the plant’s source water and evaporative
deuterium enrichment of leaf water, hydrogen isotope analyses of plant material are mainly
applied regarding hydrological conditions at different time scales. However, only
few studies have directly addressed the variability of the biochemical hydrogen
isotope fractionation occurring during biosynthesis of organic compounds (Ébio),
accounting also for a large part in the δ2H values of plants but generally assumed to be
constant.
Here we present the results from a climate-controlled growth chambers experiment where
tested the sensitivity of Ébio to different light treatments. The different light treatments were
applied to induce different metabolic status (autotrophic vs. heterotrophic) in 9 different plant
species that we grew from large storage organs (e.g. tubers or roots). The results show a
systematic Ébio shift (up to 80 ) between the different light treatments for different
compounds (i.e. long chain n-alkanes and cellulose).
We suggest that this shift is due to the different NADPH pools used by the
plants to build up the compounds from stored carbohydrates in heterotrophic or
autotrophic conditions. Our results have important implications for the calibration and
interpretation of sedimentary and tree rings records in geological studies. In addition, as the
δ2H values reflect also strongly the carbon metabolism of the plant, our findings
support the idea of δ2H values as an interesting proxy for plant physiological studies. |
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