Abstract
Soybean (Glycine max L.) plants were subjected to a number of treatments (drought, 10 mM nitrate, 150 mM NaCl, shoot meristem removal, and removal of approximately 50% of the nodules) to test the hypothesis that metabolic responses contribute to the regulation of N2 fixation. Nitrogenase activity was correlated with the activity of nodule sucrose synthase (SS), but not with that of glutamine oxoglutarate amino transferase. Leghemoglobin levels and other enzyme activities were not significantly or consistently affected by the treatments. SS mRNA was greatly reduced in nodules of drought-, salt-, and nitrate-treated plants; however, this was not correlated with changes in soluble carbohydrate, starch, amino acids, or ureides. Leghemoglobin mRNA was only slightly affected by the treatments. The time course of drought stress showed a decline in the SS transcript level by 1 d, but levels of leghemoglobin, glutamine synthetase, and ascorbate peroxidase mRNA were not markedly affected by 4 d. SS activity at 4 d was reduced by 46%. We propose that N2 fixation in soybean nodules is mediated by both the oxygen-diffusion barrier and the potential to metabolize sucrose via SS. The response to environmental perturbation may involve down-regulation of the nodule SS gene.
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Claims 13
Claim · model-written summary
Nitrogenase activity correlated with nodule sucrose synthase activity.
- Taxon
- Soybean
Glycine maxt0 - Gene
- nodule sucrose synthasee0
- Outcome
- Nitrogenase activitye0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Soybean”
e0“Nitrogenase activity was correlated with the activity of nodule sucrose synthase (SS)”
Claim · model-written summary
Nitrogenase activity did not correlate with glutamine oxoglutarate amino transferase activity.
- Taxon
- SoybeanGlycine maxt0
- Gene
- glutamine oxoglutarate amino transferasee0
- Outcome
- Nitrogenase activitye0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Soybean”
e0“Nitrogenase activity was correlated with the activity of nodule sucrose synthase (SS), but not with that of glutamine oxoglutarate amino transferase”
Claim · model-written summary
Leghemoglobin levels and other enzyme activities lacked significant or consistent treatment responses.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- treatmentse0
- Outcome
- Leghemoglobin levels and other enzyme activitiese0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Soybean”
e0“Leghemoglobin levels and other enzyme activities were not significantly or consistently affected by the treatments”
Claim · model-written summary
Drought greatly reduced nodule SS mRNA.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Soybean”
e0“SS mRNA was greatly reduced in nodules of drought-, salt-, and nitrate-treated plants”
Claim · model-written summary
Salt greatly reduced nodule SS mRNA.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Soybean”
e0“SS mRNA was greatly reduced in nodules of drought-, salt-, and nitrate-treated plants”
Claim · model-written summary
Nitrate greatly reduced nodule SS mRNA.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Soybean”
e0“SS mRNA was greatly reduced in nodules of drought-, salt-, and nitrate-treated plants”
Claim · model-written summary
SS mRNA changes did not correlate with carbohydrates, starch, amino acids or ureides.
- Taxon
- SoybeanGlycine maxt0
- Outcome
- changes in soluble carbohydrate, starch, amino acids, or ureidese0
Not reportedGeneOrgan / stageDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Soybean”
e0“this was not correlated with changes in soluble carbohydrate, starch, amino acids, or ureides”
Claim · model-written summary
Leghemoglobin mRNA was only slightly affected by treatments.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- treatmentse0
- Outcome
- Leghemoglobin mRNAe0
- Direction
- slightly affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Soybean”
e0“Leghemoglobin mRNA was only slightly affected by the treatments”
Claim · model-written summary
Drought lowered SS transcript level by one day.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- drought stresse0
- Outcome
- SS transcript levele0
- Direction
- declinee0
- Qualifier
- 1 de0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Soybean”
e0“The time course of drought stress showed a decline in the SS transcript level by 1 d”
Claim · model-written summary
Leghemoglobin, glutamine synthetase and ascorbate peroxidase mRNA were not markedly affected by four days.
- Taxon
- SoybeanGlycine maxt0
- Outcome
- levels of leghemoglobin, glutamine synthetase, and ascorbate peroxidase mRNAe0
- Direction
- not markedly affectede0
- Qualifier
- 4 de0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Soybean”
e0“levels of leghemoglobin, glutamine synthetase, and ascorbate peroxidase mRNA were not markedly affected by 4 d”
Claim · model-written summary
SS activity was reduced 46% at four days.
- Taxon
- SoybeanGlycine maxt0
- Outcome
- SS activitye0
- Direction
- reducede0
- Value
- 46%e0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Soybean”
e0“SS activity at 4 d was reduced by 46%”
Claim · model-written summary
Authors propose that oxygen diffusion and sucrose metabolism via SS mediate nodule nitrogen fixation.
- Taxon
- soybeanGlycine maxe0
- Gene
- SSe0
- Outcome
- N2 fixatione0
- Qualifier
- oxygen-diffusion barriere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Soybean”
e0“N2 fixation in soybean nodules is mediated by both the oxygen-diffusion barrier and the potential to metabolize sucrose via SS”
Claim · model-written summary
Authors propose environmental perturbation downregulates the nodule SS gene.
- Taxon
- SoybeanGlycine maxt0
- Gene
- nodule SS genee0
- Outcome
- response to environmental perturbatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Soybean”
e0“The response to environmental perturbation may involve down-regulation of the nodule SS gene”
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See all 57 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.