Transport and partitioning of CO/sub 2/ fixed by root nodules of ureide and amide producing legumes. [Vigna angularis; Glycine max; Medicago sativa]
Nodulated and denodulated roots of adzuki bean (Vigna angularis), soybean (Glycine max), and alfalfa (Medicago sativa) were exposed to /sup 14/CO/sub 2/ to investigate the contribution of nodule CO/sub 2/ fixation to assimilation and transport of fixed nitrogen. The distribution of radioactivity in xylem sap and partitioning of carbon fixed by nodules to the whole plant were measured. Radioactivity in the xylem sap of nodulated soybean and adzuki bean was located primarily (70 to 87%) in the acid fraction while the basic (amino acid) fraction contained 10 to 22%. In contrast radioactivity in the xylem sap of nodulated alfalfa was primarily in amino acids with about 20% in organic acids. Total ureide concentration was 8.1, 4.7, and 0.0 micromoles per milliliter xylem sap for soybean, adzuki bean, and alfalfa, respectively. While the major nitrogen transport products in soybeans and adzuki beans are ureides, this class of metabolites contained less than 20% of the the total radioactivity. When nodules of plants were removed, radioactivity in xylem sap decreased by 90% or more. Pulse-chase experiments indicated that CO/sub 2/ fixed by nodules was rapidly transported to shoots and incorporated into acid stable constituents. The data are consistent with a role for nodule CO/sub 2/ fixation providing carbon for the assimilation and transport of fixed nitrogen in amide-based legumes. In contrast, CO/sub 2/ fixation by nodules of ureide transporting legumes appears to contribute little to assimilation and transport of fixed nitrogen. 19 references, 2 figures, 5 tables.
- Research Organization:
- Univ. of Minnesota, St. Paul
- OSTI ID:
- 6830979
- Journal Information:
- Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 78; ISSN PLPHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ALFALFA
BACTERIA
BEANS
BIOLOGICAL MATERIALS
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON DIOXIDE FIXATION
CARBON OXIDES
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
DATA
EXPERIMENTAL DATA
FOOD
INFORMATION
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEGUMINOSAE
MATERIALS
MICROORGANISMS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANT SAP
PLANTS
RHIZOBIUM
ROOTS
SOYBEANS
SYNTHESIS
TRACER TECHNIQUES
UPTAKE
VEGETABLES