Related Experiment Video
Updated: Aug 8, 2026

13C6-Glucose Labeling Associated with LC-MS: Identification of Plant Primary Organs in Secondary Metabolite Synthesis
Published on: March 22, 2024
Isotope ratios of cellulose from plants having different photosynthetic pathways
L O Sternberg1, M J Deniro, H B Johnson
1Department of Earth and Space Sciences, University of California, Los Angeles, California 90024.
Abstract:
Hydrogen and carbon isotope ratios of cellulose nitrate and oxygen isotope ratios of cellulose from C(3), C(4), and Crassulacean acid metabolism (CAM) plants were determined for plants growing within a small area in Val Verde County, Texas. Plants having CAM had distinctly higher deuterium/hydrogen (D/H) ratios than plants having C(3) and C(4) metabolism. When hydrogen isotope ratios are plotted against carbon isotope ratios, each photosynthetic mode separates into a distinct cluster of points. C(4) plants had many D/H ratios similar to those of C(3) plants, so that hydrogen isotope ratios cannot be used to distinguish between these two photosynthetic modes. Portulaca mundula, which may have a modified photosynthetic mode between C(4) and CAM, had a hydrogen isotope ratio between those of the C(4) and CAM plants. When oxygen isotope ratios are plotted against carbon isotope ratios, no distinct clustering of the C(4) and CAM plants occurs. Thus, oxygen isotope ratios are not useful in distinguishing between these metabolic modes. A plot of hydrogen isotope ratios versus oxygen isotope ratios for this sample set shows considerable overlap between oxygen isotope ratios of the different photosynthetic modes without a concomitant overlap in the hydrogen isotope ratios of CAM and the other two photosynthetic modes. This observation is consistent with the hypothesis that higher D/H ratios in CAM plants relative to C(3) and C(4) plants are due to isotopic fractionations occurring during biochemical reactions.
More Related Videos
07:26Metabolic Pathway Confirmation and Discovery Through 13C-labeling of Proteinogenic Amino Acids
Published on: January 26, 2012
06:04Assessing Structural Traits in Triticum aestivum and Zea mays for C3 and C4 Photosynthetic Differentiation Using Free-hand and Semi-thin Sections
Published on: July 12, 2024
Related Concept Videos
C4 Pathway and CAM
C4 Pathway
The C4 pathway is used by plants such as...
Cellulose and Pectic Polysaccharides
As a cell matures, its cell wall specializes according to its type. For example, the parenchyma cells of...
The Calvin Benson Cycle
Mass Spectrometry: Isotope Effect
The Calvin Cycle
Chemistry of Carbohydrates