Abstract
A two-week salt treatment (NaCl, 100 mM) 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 Delta(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 mM 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 rats 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 12
Claim · model-written summary
Salt treatment inhibited nodule acetylene reduction activity by 50%.
- Taxon
- faba bean
Vicia fabae0 - Material
- Soravie0
- Organ / stage
- nodulese0
- Treatment
- salt treatment (NaCl, 100 mM)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 mM) induced a 50% inhibition of acetylene reduction activity (ARA) of faba bean (Vicia faba L. var. minor cv. Soravi) nodules”
Claim · model-written summary
Salt treatment increased the nodule amino acid pool.
- Taxon
- faba beanVicia fabae1
- Treatment
- salt treatment (NaCl, 100 mM)e1
- 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“associated with a large increase in the nodule pool of amino acids”
e1“A two-week salt treatment (NaCl, 100 mM) induced a 50% inhibition of acetylene reduction activity (ARA) of faba bean”
Claim · model-written summary
Salt stress increased cytosolic proline eightfold.
- Taxon
- faba beanVicia fabae2
- Organ / stage
- cytosole0
- Treatment
- salt stresse0
- Outcome
- proline concentratione1
- Direction
- enhancede0
- Value
- 8-folde0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“especially in the cytosol where its amount was 8-fold enhanced under salt stress”
e1“The proline concentration exhibited a large increase, especially in the cytosol”
e2“A two-week salt treatment (NaCl, 100 mM) induced a 50% inhibition of acetylene reduction activity (ARA) of faba bean (Vicia faba L. var. minor cv. Soravi) nodules”
Claim · model-written summary
Bacteroid proline content was less affected by salt stress.
- Taxon
- faba beanVicia fabae1
- Treatment
- salt stresse1
- 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 low proline content of bacteroids was less affected”
e1“under salt stress, whereas the low proline content of bacteroids was less affected. Increase of proline concentration in faba bean”
Claim · model-written summary
Nodule proline concentration correlated with cytosolic P5CS activity under salt stress.
- Taxon
- faba beanVicia fabae0
- Gene
- Delta(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 Delta(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 mM under salt stress.
- Taxon
- faba beanVicia fabae1
- Organ / stage
- peribacteroid space (PBS)e0
- Outcome
- proline contente0
- Direction
- greateste0
- Value
- 15.3 mMe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the greatest proline content occurred in the peribacteroid space (PBS), where proline was the most abundant amino acid, with a concentration reaching 15.3 mM under salt stress”
e1“faba bean nodules subjected to salt stress”
Claim · model-written summary
Proline was the most abundant amino acid in the peribacteroid space.
- Taxon
- faba beanVicia fabae1
- Organ / stage
- peribacteroid space (PBS)e1
- Outcome
- proline was the most abundant amino acide0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“where proline was the most abundant amino acid”
e1“faba bean nodules subjected to salt stress was correlated with an enhancement of the cytosolic Delta(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)”
Claim · model-written summary
Proline accumulation in the peribacteroid space was attributed to diffusion from the host cell 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)e0
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 rats of uptake by faba bean bacteroids”
Claim · model-written summary
Proline accumulation may partly account for 1.7-fold symbiosome enlargement under salt stress.
- Taxon
- faba beanVicia fabae1
- Outcome
- enlargement of the symbiosome volumee0
- Value
- 1.7-folde0
- Qualifier
- This accumulation could be partly responsiblee0
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”
e1“faba bean bacteroids”
Claim · model-written summary
Added proline did not stimulate bacteroid oxygen consumption.
- Taxon
- faba beanVicia fabae1
- Treatment
- addition of prolinee0
- Outcome
- O-2 consumptione0
- Direction
- stimulated neithere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“addition of proline stimulated neither O-2 consumption nor ARA”
e1“faba bean bacteroids”
Claim · model-written summary
Added proline did not stimulate bacteroid acetylene reduction activity.
- Taxon
- faba beanVicia fabae1
- Treatment
- addition of prolinee0
- Outcome
- ARAe0
- Direction
- stimulated neithere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“addition of proline stimulated neither O-2 consumption nor ARA”
e1“faba bean bacteroids”
Claim · model-written summary
The authors interpret proline as a bacteroid osmoticum.
- Taxon
- faba beanVicia fabae0
- Outcome
- osmoticume0
- Qualifier
- proline playing a rolee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“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
1 paper in the same direction as this paper
- negative
salinity · symbiosis · Vicia faba (faba bean)Positive and negative results
6 papers in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- negative
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.