Abstract
A mathematical model is developed which can be used to predict in vivo carbon isotope fractionations associated with carbon fixation in plants in terms of diffusion, CO(2) hydration, and carboxylation components. This model also permits calculation of internal CO(2) concentration for comparison with results of gas-exchange experiments. The isotope fractionations associated with carbon fixation in Kalanchoë daigremontiana and Bryophyllum tubiflorum have been measured by isolation of malic acid following dark fixation and enzymic determination of the isotopic composition of carbon-4 of this material. Corrections are made for residual malic acid, fumarase activity, and respiration. Comparison of these data with calculations from the model indicates that the rate of carbon fixation is limited principally by diffusion, rather than by carboxylation. Processes subsequent to the initial carboxylation also contribute to the over-all isotopic composition of the plant.
Keywords
Isotopes of carbonFractionationCarbon fixationIsotopeFixation (population genetics)ChemistryCarbon fibersIsotope fractionationEnvironmental chemistryRadiochemistryAnalytical Chemistry (journal)Materials sciencePhotosynthesisChromatographyBiochemistryTotal organic carbonPhysicsGeneNuclear physics
Affiliated Institutions
Related Publications
Effect of Varying CO<sub>2</sub> Partial Pressure on Photosynthesis and on Carbon Isotope Composition of Carbon-4 of Malate from the Crassulacean Acid Metabolism Plant <i>Kalanchoë daigremontiana</i> Hamet et Perr.
Intact leaves of Kalanchoë daigremontiana were exposed to CO(2) partial pressures of 100, 300, and 1000 microbars. Malic acid was extracted, purified, and degraded in order to o...
Carbon Isotope Discrimination measured Concurrently with Gas Exchange to Investigate CO2 Diffusion in Leaves of Higher Plants
Conventional gas-exchange techniques that measure the stomatal conductance and rate of CO2 assimilation of leaves were combined with measurements of the carbon isotope compositi...
On the Nature of Carbon Isotope Discrimination in C4 Species
Theory is developed to explain the carbon isotopic composition of plants with the dicarboxylic acid (C4) pathway of carbon fixation. It is shown how leakage of inorganic carbon ...
Solubility of gases and the temperature dependency of whole leaf affinities for carbon dioxide and oxygen: an alternative perspective.
An analysis of the kinetics of simultaneous photosynthesis and photorespiration at the end of a diffusion path is applied to observed net photosynthetic rate as a function of O(...
Diffusion of CO<sub>2</sub>and other gases inside leaves
SUMMARY Diffusion of CO 2 in the intercellular airspaces of the leaf mesophyll is one of the many processes that can limit photosynthetic carbon assimilation there. This limitat...
Publication Info
- Year
- 1980
- Type
- article
- Volume
- 66
- Issue
- 5
- Pages
- 931-934
- Citations
- 75
- Access
- Closed
External Links
Social Impact
Altmetric
PlumX Metrics
Social media, news, blog, policy document mentions
Citation Metrics
75
OpenAlex
Cite This
Marion H. O’Leary,
C. B. Osmond
(1980).
Diffusional Contribution to Carbon Isotope Fractionation during Dark CO<sub>2</sub> Fixation in CAM Plants.
PLANT PHYSIOLOGY
, 66
(5)
, 931-934.
https://doi.org/10.1104/pp.66.5.931
Identifiers
- DOI
- 10.1104/pp.66.5.931