Abstract
A two‐week salt treatment (NaCl, 100 m M ) induced a 50% inhibition of acetylene reduction activity (ARA) of faba bean ( Vicia faba L. var. minor cv. Soravi) nodules, associated with a large increase in the nodule pool of amino acids. The concentration of proline in the different nodule compartments was determined after calculating their respective volumes from their areas on electron micrographs. The proline concentration exhibited a large increase, especially in the cytosol where its amount was 8‐fold enhanced under salt stress, whereas the low proline content of bacteroids was less affected. Increase of proline concentration in faba bean nodules subjected to salt stress was correlated with an enhancement of the cytosolic Δ 1 ‐pyrroline‐5‐carboxylate synthetase (EC 2.7.2.11 + EC 1.2.1.41; P5CS) activity. Experiments with purified symbiosome preparations showed that the greatest proline content occurred in the peribacteroid space (PBS), where proline was the most abundant amino acid, with a concentration reaching 15.3 m M under salt stress. Proline accumulation in the PBS resulted both from a diffusive transport from the host cell to the symbiosomes through the peribacteroid membrane (PBM) and from the very low rate of uptake by faba bean bacteroids. This accumulation could be partly responsible for the 1.7‐fold enlargement of the symbiosome volume observed in salt‐stressed nodules. In incubations of bacteroids, isolated from salt‐stressed or unstressed plants and supplied with O 2 by purified oxyleghemoglobin, addition of proline stimulated neither O 2 consumption nor ARA. These results were consistent with proline playing a role as osmoticum, rather than energy source for bacteroid N 2 fixation in amide‐exporting legumes such as faba bean.
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Claims 11
Claim · model-written summary
Two-week 100 m M NaCl inhibited nodule acetylene reduction by 50%.
- Taxon
- faba bean
Vicia fabae0 - Organ / stage
- nodulese0
- Treatment
- two‐week salt treatment (NaCl, 100 m M )e0
- Outcome
- acetylene reduction activity (ARA)e0
- Direction
- inhibitione0
- Value
- 50%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A two‐week salt treatment (NaCl, 100 m M ) induced a 50% inhibition of acetylene reduction activity (ARA) of faba bean ( Vicia faba L. var. minor cv. Soravi) nodules, associated with a large increase in the nodule pool of amino acids.”
Claim · model-written summary
Salt treatment increased the nodule amino acid pool.
- Taxon
- faba beanVicia fabae0
- Treatment
- two‐week salt treatment (NaCl, 100 m M )e0
- Outcome
- nodule pool of amino acidse0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A two‐week salt treatment (NaCl, 100 m M ) induced a 50% inhibition of acetylene reduction activity (ARA) of faba bean ( Vicia faba L. var. minor cv. Soravi) nodules, associated with a large increase in the nodule pool of amino acids.”
Claim · model-written summary
Salt stress increased cytosolic nodule proline eightfold.
- Taxon
- faba beanVicia fabat0
- Organ / stage
- cytosole0
- Treatment
- salt stresse0
- Outcome
- proline concentratione0
- Direction
- increasee0
- Value
- 8‐folde0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The proline concentration exhibited a large increase, especially in the cytosol where its amount was 8‐fold enhanced under salt stress, whereas the low proline content of bacteroids was less affected.”
t0“Proline accumulation inside symbiosomes of faba bean nodules under salt stress”
Claim · model-written summary
Bacteroid proline content was less affected by salt stress.
- Taxon
- faba beanVicia fabat0
- Treatment
- salt stresse0
- Outcome
- proline content of bacteroidse0
- Direction
- less affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The proline concentration exhibited a large increase, especially in the cytosol where its amount was 8‐fold enhanced under salt stress, whereas the low proline content of bacteroids was less affected.”
t0“Proline accumulation inside symbiosomes of faba bean nodules under salt stress”
Claim · model-written summary
Salt-induced nodule proline increase correlated with enhanced cytosolic P5CS activity.
- Taxon
- faba beanVicia fabae0
- Treatment
- salt stresse0
- Gene
- cytosolic Δ 1 ‐pyrroline‐5‐carboxylate synthetasee0
- Outcome
- proline concentratione0
- Direction
- Increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increase of proline concentration in faba bean nodules subjected to salt stress was correlated with an enhancement of the cytosolic Δ 1 ‐pyrroline‐5‐carboxylate synthetase (EC 2.7.2.11 + EC 1.2.1.41; P5CS) activity.”
Claim · model-written summary
The peribacteroid space had the greatest proline content, reaching 15.3 m M under salt stress.
- Taxon
- faba beanVicia fabat0
- Organ / stage
- peribacteroid space (PBS)e0
- Treatment
- salt stresse0
- Outcome
- greatest proline contente0
- Value
- 15.3 m Me0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Experiments with purified symbiosome preparations showed that the greatest proline content occurred in the peribacteroid space (PBS), where proline was the most abundant amino acid, with a concentration reaching 15.3 m M under salt stress.”
t0“Proline accumulation inside symbiosomes of faba bean nodules under salt stress”
Claim · model-written summary
Proline was the most abundant amino acid in the peribacteroid space.
- Taxon
- faba beanVicia fabat0
- Outcome
- proline was the most abundant amino acide0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“proline was the most abundant amino acid, with a concentration reaching 15.3 m M under salt stress”
t0“Proline accumulation inside symbiosomes of faba bean nodules under salt stress”
Claim · model-written summary
Peribacteroid proline accumulation was attributed to host-cell diffusion and low bacteroid uptake.
- Taxon
- faba beanVicia fabae0
- Outcome
- Proline accumulation in the PBSe0
- Qualifier
- diffusive transport from the host cell to the symbiosomes through the peribacteroid membrane (PBM) and from the very low rate of uptake by faba bean bacteroidse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Proline accumulation in the PBS resulted both from a diffusive transport from the host cell to the symbiosomes through the peribacteroid membrane (PBM) and from the very low rate of uptake by faba bean bacteroids.”
Claim · model-written summary
Proline accumulation may partly explain 1.7-fold symbiosome enlargement in salt-stressed nodules.
- Taxon
- faba beanVicia fabat0
- Outcome
- enlargement of the symbiosome volumee0
- Value
- 1.7‐folde0
- Qualifier
- This accumulatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This accumulation could be partly responsible for the 1.7‐fold enlargement of the symbiosome volume observed in salt‐stressed nodules.”
t0“Proline accumulation inside symbiosomes of faba bean nodules under salt stress”
Claim · model-written summary
Added proline stimulated neither bacteroid oxygen consumption nor acetylene reduction.
- Taxon
- faba beanVicia fabat0
- Treatment
- addition of prolinee0
- Outcome
- O 2 consumption nor ARAe0
- Direction
- stimulated neithere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In incubations of bacteroids, isolated from salt‐stressed or unstressed plants and supplied with O 2 by purified oxyleghemoglobin, addition of proline stimulated neither O 2 consumption nor ARA.”
t0“Proline accumulation inside symbiosomes of faba bean nodules under salt stress”
Claim · model-written summary
The authors interpreted proline as an osmoticum rather than an energy source for bacteroid nitrogen fixation.
- Taxon
- faba beanVicia fabae0
- Outcome
- proline playing a role as osmoticume0
- Qualifier
- rather than energy source for bacteroid N 2 fixatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These results were consistent with proline playing a role as osmoticum, rather than energy source for bacteroid N 2 fixation in amide‐exporting legumes such as faba bean.”
The same questions in other papers
sodium chloride · symbiosis · Vicia faba (faba bean)Results agree
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- negative
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6 papers in the same direction as this paper · 2 in the opposite direction
- positive
- positive
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5 papers more in this group
See all 9 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.