Transport and partitioning of CO/sub 2/ fixed by root nodules of ureide and amide producing legumes. [Vigna angularis; Glycine max; Medicago sativa]

Journal Article · Tue Jan 01 00:00:00 EST 1985 · Plant Physiol.; (United States)

OSTI ID:6830979

Vance, C P; Boylan, K L.M.; Maxwell, C A; Heichel, G H; Hardman, L L

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), Vol. 78
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CARBON DIOXIDE
UPTAKE
LEGUMINOSAE
CARBON DIOXIDE FIXATION
PLANT SAP
CHEMICAL COMPOSITION
ALFALFA
BEANS
CARBON 14 COMPOUNDS
EXPERIMENTAL DATA
PHOTOSYNTHESIS
ROOTS
SOYBEANS
TRACER TECHNIQUES
BACTERIA
BIOLOGICAL MATERIALS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
DATA
FOOD
INFORMATION
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MATERIALS
MICROORGANISMS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PLANTS
RHIZOBIUM
SYNTHESIS
VEGETABLES
550501* - Metabolism- Tracer Techniques