Abstract
Soybean plants (Glycine max [L.] Merr) were grown in sand culture with 2 millimolar nitrate for 37 days and then supplied with 15 millimolar nitrate for 7 days. Control plants received 2 millimolar nitrate and 13 millimolar chloride and, after the 7-day treatment period, all plants were supplied with nil nitrate. The temporary treatment with high nitrate inhibited nitrogenase (acetylene reduction) activity by 80% whether or not Rhizobium japonicum bacteroids had nitrate reductase (NR) activity. The pattern of nitrite accumulation in nodules formed by NR(+) rhizobia was inversely related to the decrease and recovery of nitrogenase activity. However, nitrite concentration in nodules formed by NR(-) rhizobia appeared to be too low to explain the inhibition of nitrogenase. Carbohydrate composition was similar in control nodules and nodules receiving 15 millimolar nitrate suggesting that the inhibition of nitrogenase by nitrate was not related to the availability of carbohydrate.Nodules on plants treated with 15 millimolar nitrate contained higher concentrations of amino N and, especially, ureide N than control nodules and, after withdrawal of nitrate, reduced N content of treated and control nodules returned to similar levels. The accumulation of N(2) fixation products in nodules in response to high nitrate treatment was observed with three R. japonicum strains, two NR(+) and one NR(-). The high nitrate treatment did not affect the allantoate/allantoin ratio or the proportion of amino N or ureide N in bacteroids (4%) and cytosol (96%).
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Claims 11
Claim · model-written summary
High nitrate inhibited soybean nodule nitrogenase activity by 80% regardless of rhizobial nitrate reductase activity.
- Taxon
- Soybean
Glycine maxe0 - Treatment
- 15 millimolar nitratee0
- Interactor
- Rhizobium japonicume2symbiont
- Outcome
- nitrogenase (acetylene reduction) activitye2
- Direction
- inhibitede2
- Value
- 80%e2
- Comparator
- 2 millimolar nitrate and 13 millimolar chloridee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean plants (Glycine max [L.] Merr) were grown in sand culture with 2 millimolar nitrate for 37 days and then supplied with 15 millimolar nitrate for 7 days”
e1“Control plants received 2 millimolar nitrate and 13 millimolar chloride”
e2“temporary treatment with high nitrate inhibited nitrogenase (acetylene reduction) activity by 80% whether or not Rhizobium japonicum bacteroids had nitrate reductase (NR) activity”
Claim · model-written summary
Nitrite accumulation in nodules with NR-positive rhizobia was inversely related to nitrogenase decrease and recovery.
- Taxon
- SoybeanGlycine maxe1
- Organ / stage
- nodulese0
- Interactor
- NR(+) rhizobiae0symbiont
- Outcome
- nitrite accumulation in nodulese0
- Direction
- inversely relatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“pattern of nitrite accumulation in nodules formed by NR(+) rhizobia was inversely related to the decrease and recovery of nitrogenase activity”
e1“Soybean plants (Glycine max [L.] Merr)”
Claim · model-written summary
Nitrite in nodules with NR-negative rhizobia appeared too low to explain nitrogenase inhibition.
- Taxon
- SoybeanGlycine maxe1
- Organ / stage
- nodulese0
- Interactor
- NR(-) rhizobiae0symbiont
- Outcome
- inhibition of nitrogenasee0
- Qualifier
- nitrite concentratione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“nitrite concentration in nodules formed by NR(-) rhizobia appeared to be too low to explain the inhibition of nitrogenase”
e1“Soybean plants (Glycine max [L.] Merr)”
Claim · model-written summary
Carbohydrate composition was similar in control and high-nitrate soybean nodules.
- Taxon
- SoybeanGlycine maxe1
- Treatment
- 15 millimolar nitratee0
- Outcome
- Carbohydrate compositione0
- Direction
- similare0
- Comparator
- control nodulese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Carbohydrate composition was similar in control nodules and nodules receiving 15 millimolar nitrate”
e1“Soybean plants (Glycine max [L.] Merr)”
Claim · model-written summary
The similar carbohydrate composition suggests nitrate inhibition was unrelated to carbohydrate availability.
- Taxon
- SoybeanGlycine maxe1
- Outcome
- inhibition of nitrogenasee0
- Qualifier
- availability of carbohydratee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“inhibition of nitrogenase by nitrate was not related to the availability of carbohydrate”
e1“Soybean plants (Glycine max [L.] Merr)”
Claim · model-written summary
High nitrate increased amino N in soybean nodules.
- Taxon
- SoybeanGlycine maxe1
- Organ / stage
- Nodulese0
- Treatment
- 15 millimolar nitratee0
- Outcome
- concentrations of amino Ne0
- Direction
- highere0
- Comparator
- control nodulese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nodules on plants treated with 15 millimolar nitrate contained higher concentrations of amino N and, especially, ureide N than control nodules”
e1“Soybean plants (Glycine max [L.] Merr)”
Claim · model-written summary
High nitrate increased ureide N especially in soybean nodules.
- Taxon
- SoybeanGlycine maxe1
- Organ / stage
- Nodulese0
- Treatment
- 15 millimolar nitratee0
- Outcome
- ureide Ne0
- Direction
- highere0
- Comparator
- control nodulese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nodules on plants treated with 15 millimolar nitrate contained higher concentrations of amino N and, especially, ureide N than control nodules”
e1“Soybean plants (Glycine max [L.] Merr)”
Claim · model-written summary
After nitrate withdrawal, reduced N in treated and control soybean nodules returned to similar levels.
- Taxon
- SoybeanGlycine maxe1
- Organ / stage
- nodulese0
- Outcome
- reduced N contente0
- Direction
- returned to similar levelse0
- Comparator
- control nodulese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“after withdrawal of nitrate, reduced N content of treated and control nodules returned to similar levels”
e1“Soybean plants (Glycine max [L.] Merr)”
Claim · model-written summary
High nitrate caused accumulation of N2 fixation products in nodules with three R. japonicum strains.
- Taxon
- SoybeanGlycine maxe1
- Treatment
- high nitrate treatmente0
- Interactor
- R. japonicume0symbiont
- Outcome
- accumulation of N(2) fixation products in nodulese0
- Direction
- accumulatione0
- Value
- threee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“accumulation of N(2) fixation products in nodules in response to high nitrate treatment was observed with three R. japonicum strains”
e1“Soybean plants (Glycine max [L.] Merr)”
Claim · model-written summary
High nitrate did not alter the nodule allantoate/allantoin ratio.
- Taxon
- SoybeanGlycine maxe1
- Treatment
- high nitrate treatmente0
- Outcome
- allantoate/allantoin ratioe0
- Direction
- did not affecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high nitrate treatment did not affect the allantoate/allantoin ratio”
e1“Soybean plants (Glycine max [L.] Merr)”
Claim · model-written summary
High nitrate did not alter the proportions of amino or ureide N in bacteroids and cytosol.
- Taxon
- SoybeanGlycine maxe1
- Organ / stage
- bacteroidse0
- Treatment
- high nitrate treatmente0
- Outcome
- proportion of amino N or ureide Ne0
- Direction
- did not affecte0
- Qualifier
- cytosol (96%)e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high nitrate treatment did not affect the allantoate/allantoin ratio or the proportion of amino N or ureide N in bacteroids (4%) and cytosol (96%)”
e1“Soybean plants (Glycine max [L.] Merr)”
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