Abstract
Experiments were carried out to investigate if drought stress affects the ability of bacteroids from soybean (Glycine max L.) root nodules to utilize proline and malate to support nitrogenase activity. The bacteroids were isolated in sub-ambient oxygen and nitrogenase activity was measured by acetylene reduction. Nitrogenase activity supported by proline was 8-fold higher in bacteroids from drought-stressed nodules than in bacteroids from control nodules. In contrast to the results with proline there was no significant response to drought stress in the rate of bacteroid nitrogenase activity supported by malate. The effect of drought stress on transport of proline and malate across the symbiosome membrane was investigated by incubation of symbiosomes isolated in sub-ambient oxygen with radioactive tracers. Drought stress tended to increase the rate of proline uptake relative to a minor decrease in malate uptake into symbiosomes in response to drought. There was no indication of a saturable camer in the symbiosome membrane for either substrate at concentrations in the range 0.1-2 mM. The rate of malate uptake into symbiosomes was twice as high as the rate of proline uptake at all substrate levels tested. The protein composition of the symbiosome membrane was altered in response to drought stress and these changes may relate .to the permeability of the symbiosome membrane.
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 7
Claim · model-written summary
Nitrogenase activity supported by proline was 8-fold higher in bacteroids from drought-stressed nodules than in control nodules.
- Taxon
- soybean
Glycine maxt0 - Treatment
- drought-stressed nodulese2
- Interactor
- bacteroidse2symbiont
- Outcome
- Nitrogenase activity supported by prolinee2
- Direction
- highere2
- Value
- 8-folde2
- Comparator
- control nodulese2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“root nodules of soybean”
e2“Nitrogenase activity supported by proline was 8-fold higher in bacteroids from drought-stressed nodules than in bacteroids from control nodules”
Claim · model-written summary
Drought stress caused no significant change in bacteroid nitrogenase activity supported by malate.
- Taxon
- soybeanGlycine maxt0
- Treatment
- drought stresse3
- Interactor
- bacteroide3symbiont
- Outcome
- rate of bacteroid nitrogenase activity supported by malatee3
- Direction
- no_changeinferrede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“root nodules of soybean”
e3“In contrast to the results with proline there was no significant response to drought stress in the rate of bacteroid nitrogenase activity supported by malate”
Claim · model-written summary
Drought stress tended to increase the rate of proline uptake into symbiosomes.
- Taxon
- soybeanGlycine maxt0
- Treatment
- Drought stresse5
- Outcome
- rate of proline uptakee5
- Direction
- increasee5
- Qualifier
- tended toe5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“root nodules of soybean”
e5“Drought stress tended to increase the rate of proline uptake relative to a minor decrease in malate uptake into symbiosomes”
Claim · model-written summary
Drought stress caused a minor decrease in malate uptake into symbiosomes.
- Taxon
- soybeanGlycine maxt0
- Treatment
- droughte5
- Outcome
- malate uptake into symbiosomese5
- Direction
- decreasee5
- Qualifier
- minore5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“root nodules of soybean”
e5“a minor decrease in malate uptake into symbiosomes in response to drought”
Claim · model-written summary
No saturable carrier for either substrate was indicated in the symbiosome membrane at 0.1-2 mM.
- Taxon
- soybeanGlycine maxt0
- Outcome
- saturable camer in the symbiosome membranee6
- Value
- 0.1-2 mMe6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“root nodules of soybean”
e6“There was no indication of a saturable camer in the symbiosome membrane for either substrate at concentrations in the range 0.1-2 mM”
Claim · model-written summary
Malate uptake into symbiosomes was twice as high as proline uptake at all substrate levels tested.
- Taxon
- soybeanGlycine maxt0
- Outcome
- rate of malate uptake into symbiosomese7
- Value
- twice as highe7
- Qualifier
- at all substrate levels testede7
- Comparator
- rate of proline uptakee7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“root nodules of soybean”
e7“The rate of malate uptake into symbiosomes was twice as high as the rate of proline uptake at all substrate levels tested”
Claim · model-written summary
The protein composition of the symbiosome membrane was altered by drought stress.
- Taxon
- soybeanGlycine maxt0
- Treatment
- drought stresse7
- Outcome
- The protein composition of the symbiosome membranee7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“root nodules of soybean”
e7“The protein composition of the symbiosome membrane was altered in response to drought stress”
The same questions in other papers
drought · physiology: osmolytes · Glycine max (soybean)Results differ
9 papers in the same direction as this paper · 11 in the opposite direction
- positive
- negative
- negative
17 papers more in this group
See all 21 papers →drought · physiology: enzyme activity · Glycine max (soybean)Results differ
17 papers in the same direction as this paper · 6 in the opposite direction
- no effect
- no effect
- negative
20 papers more in this group
See all 24 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.