Abstract
The sensitivity of N2 fixation to drought stress in soybean (Glycine max Merr.) has been shown to be associated with high ureide accumulation in the shoots, which has led to the hypothesis that N2 fixation during drought is decreased by a feedback mechanism. The ureide feedback hypothesis was tested directly by measuring the effect of 10 mM ureide applied by stem infusion or in the nutrient solution of hydroponically grown plants on acetylene reduction activity (ARA). An almost complete inhibition of ARA was observed within 4 to 7 d after treatment, accompanied by an increase in ureide concentration in the shoot but not in the nodules. The inhibition of ARA resulting from ureide treatments was dependent on the concentration of applied ureide. Urea also inhibited ARA but asparagine resulted in the greatest inhibition of nodule activity. Because ureides did not accumulate in the nodule upon ureide treatment, it was concluded that they were not directly inhibitory to the nodules but that their influence mediated through a derivative compound, with asparagine being a potential candidate. Ureide treatment resulted in a continual decrease in nodule permeability to O2 simultaneous with the inhibition of nitrogenase activity during a 5-d treatment period, although it was not clear whether the latter phenomenon was a consequence or a cause of the decrease in the nodule permeability to O2.
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Claims 9
Claim · model-written summary
Ureide treatment almost completely inhibited acetylene reduction activity within 4 to 7 days.
- Taxon
- Soybean
Glycine maxt0 - Treatment
- 10 mM ureidee1
- Outcome
- ARAe0
- Direction
- inhibitione0
- Qualifier
- within 4 to 7 de0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“An almost complete inhibition of ARA was observed within 4 to 7 d after treatment”
e1“10 mM ureide applied by stem infusion or in the nutrient solution”
t0“Soybean”
Claim · model-written summary
Ureide treatment increased shoot ureide concentration.
- Taxon
- SoybeanGlycine maxt0
- Organ / stage
- shoote0
- Treatment
- 10 mM ureidee1
- Outcome
- ureide concentratione0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“accompanied by an increase in ureide concentration in the shoot but not in the nodules”
e1“10 mM ureide applied by stem infusion or in the nutrient solution”
t0“Soybean”
Claim · model-written summary
Ureide concentration did not increase in nodules following treatment.
- Taxon
- SoybeanGlycine maxt0
- Organ / stage
- nodulese0
- Treatment
- 10 mM ureidee1
- Outcome
- ureide concentratione0
- Direction
- note0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increase in ureide concentration in the shoot but not in the nodules”
e1“10 mM ureide applied by stem infusion or in the nutrient solution”
t0“Soybean”
Claim · model-written summary
Inhibition of acetylene reduction depended on applied ureide concentration.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- ureide treatmentse0
- Outcome
- inhibition of ARAe0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The inhibition of ARA resulting from ureide treatments was dependent on the concentration of applied ureide”
t0“Soybean”
Claim · model-written summary
Urea inhibited acetylene reduction activity.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- Ureae0
- Outcome
- ARAe0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Urea also inhibited ARA”
t0“Soybean”
Claim · model-written summary
Asparagine caused the greatest inhibition of nodule activity.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- asparaginee0
- Outcome
- nodule activitye0
- Direction
- inhibitione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“asparagine resulted in the greatest inhibition of nodule activity”
t0“Soybean”
Claim · model-written summary
Authors infer ureides act through a derivative rather than directly on nodules, with asparagine a candidate.
- Taxon
- SoybeanGlycine maxt0
- Compound
- asparaginee0
- Outcome
- inhibitory to the nodulese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“they were not directly inhibitory to the nodules but that their influence mediated through a derivative compound, with asparagine being a potential candidate”
t0“Soybean”
Claim · model-written summary
Ureide treatment continually decreased nodule oxygen permeability over five days.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- Ureide treatmente0
- Outcome
- nodule permeability to O2e0
- Direction
- decreasee0
- Qualifier
- 5-d treatment periode0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ureide treatment resulted in a continual decrease in nodule permeability to O2 simultaneous with the inhibition of nitrogenase activity during a 5-d treatment period”
t0“Soybean”
Claim · model-written summary
Ureide treatment inhibited nitrogenase activity during the five-day period.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- Ureide treatmente0
- Outcome
- nitrogenase activitye0
- Direction
- inhibitione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ureide treatment resulted in a continual decrease in nodule permeability to O2 simultaneous with the inhibition of nitrogenase activity during a 5-d treatment period”
t0“Soybean”
The same questions in other papers
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1 paper in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- no effect
N-acylurea · symbiosis · Glycine max (soybean)Results agree
2 papers in the same direction as this paper
- negative
- negative
nitrogen · symbiosis · Glycine max (soybean)Positive and negative results
86 papers in the same direction as this paper · 59 in the opposite direction
- positive
- positive
- negative
142 papers more in this group
See all 146 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.