Initial organic products of fixation of (/sup 13/N)dinitrogen by root nodules of soybean (Glycine max)
When detached soybean Glycine max (L.) Merr. cv. Hark, nodules assimilate (/sup 13/N)N/sub 2/, the initial organic product of fixation is glutamine; glutamate becomes more highly radioactive than glutamine within 1 minute; /sup 13/N in alanine becomes detectable at 1 minute of fixation and increases rapidly between 1 and 2 minutes. After 15 minutes of fixation, the major /sup 13/N-labeled organic products in both detached and attached nodules are glutamate and alanine, plus, in the case of attached nodules, an unidentified substance, whereas (/sup 13/N)glutamine comprises only a small fraction of organic /sup 13/N, and very little /sup 13/N is detected in asparagine. The fixation of (/sup 13/N)N/sub 2/ into organic products was inhibited more than 99 percent by C/sub 2/H/sub 2/ (10 percent, v/v). The results support the idea that the glutamine synthetase-glutamate synthase pathway is the primary route for assimilation of fixed nitrogen in soybean nodules.
- Research Organization:
- Michigan State Univ., East Lansing
- OSTI ID:
- 7053719
- Journal Information:
- Plant Physiol.; (United States), Vol. 61:6
- Country of Publication:
- United States
- Language:
- English
Similar Records
Free amino acid content and metabolic activities of setting and aborting soybean ovaries. [Glycine max (L. ) Merr]
Dark CO/sub 2/ fixation and amino acid metabolism in symbiotic N/sub 2/-fixing systems. Labeling studies with /sup 14/C and /sup 13/N-labeled tracers. [Roots of soybean plants and alders]
Related Subjects
NITROGEN 13
BIOLOGICAL ACCUMULATION
SOYBEANS
NITROGEN FIXATION
ALANINES
ASPARAGINE
BIOCHEMISTRY
GLUTAMINE
LABELLED COMPOUNDS
NITROGEN
ROOTS
AMIDES
AMINO ACIDS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
CHEMISTRY
CRYOGENIC FLUIDS
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
FLUIDS
FOOD
ISOTOPES
LIGHT NUCLEI
MINUTES LIVING RADIOISOTOPES
NITROGEN ISOTOPES
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADIOISOTOPES
VEGETABLES
550500* - Metabolism
550501 - Metabolism- Tracer Techniques
550200 - Biochemistry