Abstract
Nitrate supplied to legume plants inhibits the activity of nitrogenase in Rhizobium bacteroids in root nodules. The accumulation of amino N which is known to occur in Glycine max (L.) Merr. nodules as nitrogenase activity declines was studied in more detail by analysis of changes in free amino acid composition in response to high nitrate supply. A 6-fold increase in asparagine concentration in Bradyrhizobium japonicum bacteroids was found about the time of maximum nitrogenase inhibition. However, the accumulation of amino acids in soybean nodules lagged behind the inhibition of nitrogenase. Furthermore, in studies of a second legume, Phaseolus vulgaris (L.) inoculated with two different strains of Rhizobium phaseoli, a high nitrate treatment inhibited nitrogenase but had no significant effect on amino acid composition of nodules. The possibility that nitrate may interfere with the supply of carbon substrates to bacteroids was examined by the analysis of organic acids in legume nodules supplied with nitrate. Nitrate had a small (10-20%) negative effect on the concentration of tricarboxylic acid cycle acids in P. vulgaris nodules. However, in G. max nodules, high nitrate treatment resulted in significant increases in the concentration of malate, succinate, fumarate, and citrate. Thus, carbon deprivation of bacteroids also seems unlikely as a cause of the inhibition of nitrogenase by nitrate. There was a transient increase in ammonium concentration in P. vulgaris nodules in response to high nitrate treatment. This effect was rapid relative to other effects of nitrate on nodule composition and was roughly coincident with the rapid decline in acetylene reduction activity.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
High nitrate inhibited nitrogenase activity in Phaseolus vulgaris nodules.
- Taxon
- Phaseolus vulgaris
Phaseolus vulgarise0 - Treatment
- high nitrate treatmente0
- Interactor
- Rhizobium phaseoliRhizobium phaseolie0symbiont
- Outcome
- nitrogenasee0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phaseolus vulgaris (L.) inoculated with two different strains of Rhizobium phaseoli, a high nitrate treatment inhibited nitrogenase”
Claim · model-written summary
High nitrate did not significantly alter amino acid composition of Phaseolus vulgaris nodules.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarise0
- Treatment
- high nitrate treatmente0
- Interactor
- Rhizobium phaseoliRhizobium phaseolie0symbiont
- Outcome
- amino acid composition of nodulese0
- Direction
- no significant effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phaseolus vulgaris (L.) inoculated with two different strains of Rhizobium phaseoli, a high nitrate treatment inhibited nitrogenase but had no significant effect on amino acid composition of nodules”
Claim · model-written summary
Asparagine concentration in Bradyrhizobium japonicum bacteroids increased sixfold near maximum nitrogenase inhibition in Glycine max nodules.
- Taxon
- Glycine max
Glycine maxe0 - Interactor
- Bradyrhizobium japonicum
Bradyrhizobium japonicume1symbiont - Outcome
- asparagine concentration in Bradyrhizobium japonicum bacteroidse1
- Direction
- increasee1
- Value
- 6-folde1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Glycine max (L.) Merr. nodules”
e1“A 6-fold increase in asparagine concentration in Bradyrhizobium japonicum bacteroids was found about the time of maximum nitrogenase inhibition.”
Claim · model-written summary
Amino acid accumulation in soybean nodules lagged behind nitrogenase inhibition.
- Taxon
- soybeanGlycine maxe0
- Organ / stage
- nodulese0
- Outcome
- accumulation of amino acids in soybean nodulese0
- Direction
- lagged behinde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“accumulation of amino acids in soybean nodules lagged behind the inhibition of nitrogenase”
Claim · model-written summary
Nitrate reduced tricarboxylic acid cycle acid concentration in Phaseolus vulgaris nodules by 10-20%.
- Taxon
- P. vulgarisPhaseolus vulgarise0
- Treatment
- Nitratee0
- Outcome
- concentration of tricarboxylic acid cycle acidse0
- Direction
- negative effecte0
- Value
- 10-20%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrate had a small (10-20%) negative effect on the concentration of tricarboxylic acid cycle acids in P. vulgaris nodules.”
Claim · model-written summary
High nitrate significantly increased malate, succinate, fumarate, and citrate concentrations in Glycine max nodules.
- Taxon
- G. maxGlycine maxe0
- Treatment
- high nitrate treatmente0
- Outcome
- concentration of malate, succinate, fumarate, and citratee0
- Direction
- increasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in G. max nodules, high nitrate treatment resulted in significant increases in the concentration of malate, succinate, fumarate, and citrate”
Claim · model-written summary
High nitrate transiently increased ammonium concentration in Phaseolus vulgaris nodules.
- Taxon
- P. vulgarisPhaseolus vulgarise0
- Treatment
- high nitrate treatmente0
- Outcome
- ammonium concentratione0
- Direction
- increasee0
- Qualifier
- transiente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“transient increase in ammonium concentration in P. vulgaris nodules in response to high nitrate treatment”
Claim · model-written summary
The ammonium increase coincided roughly with declining acetylene reduction activity in Phaseolus vulgaris nodules.
- Taxon
- P. vulgarisPhaseolus vulgarise1
- Organ / stage
- nodulese1
- Outcome
- acetylene reduction activitye0
- Direction
- declinee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This effect was rapid relative to other effects of nitrate on nodule composition and was roughly coincident with the rapid decline in acetylene reduction activity.”
e1“transient increase in ammonium concentration in P. vulgaris nodules”
The same questions in other papers
nitrogen · molecular: metabolites · Phaseolus vulgaris (common bean)Results differ
7 papers in the same direction as this paper · 3 in the opposite direction
- positive
- positive
- positive
7 papers more in this group
See all 11 papers →nitrogen · molecular: metabolites · Glycine max (soybean)Results differ
43 papers in the same direction as this paper · 37 in the opposite direction
- positive
- positive
- positive
77 papers more in this group
See all 81 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.