Abstract
Growing barley ( Hordeum vulgare L.) plants for 7 days on NaCl solutions (20–200 mM) decreased chlorophyll (Chl) a and b content with respect to that in untreated control plants. The content of free proline and the plant ability to synthesize 5-aminolevulinic acid (ALA) started to increase in parallel at salt concentrations of 20–50 mM. The maximum amount of ALA accumulated in plants grown at 100 mM NaCl was twofold higher than in control plants grown on fresh water. In this case the proline content increased 2.8-fold. On further increase in salt concentration, the rate of ALA accumulation decreased, approaching control values at 150 mM NaCl; even lower rates were observed at 200 mM NaCl. The reduced ability to synthesize ALA was accompanied by an increase in proline content. The albino tissue of plants treated at the seed stage with the antibiotic streptomycin lost its ability to synthesize ALA needed for Chl formation. The proline content in the albino tissue was tenfold higher than in control green plants and was 30-fold higher when the plants were grown on solutions with 100 mM NaCl. No effect of NaCl on ALA-dehydratase activity was noted. As NaCl concentration was raised, there occurred the decrease in magnesium chelatase activity, accumulation of reactive oxygen species (ROS), the increase in ascorbate peroxidase activity, and a slight decrease in lipid peroxidation level. Growing plants in the presence of 150 mM NaCl and 10 or 60 mg/l exogenous ALA led to the increase in proline content (by a factor of 1.8 and 4.2, respectively) and to the decrease in ROS content, in comparison with plants grown on salt solutions without ALA. Furthermore, in the presence of exogenous ALA, the parameters of seedling growth became similar to those of NaCl-untreated plants. The role of ALA in plants as an antistress agent is considered. ALA is supposed to confer tolerance to salt stress by taking part in Chl and heme biosynthesis and also through functioning as a plant growth regulator. A hypothesis is put forward that the impairment of ALA-synthesizing ability may redirect metabolic conversions of glutamic acid from Chl and heme synthesis to the proline synthesis pathway, which would stimulate proline biosynthesis and improve salt tolerance.
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Claims 20
Claim · model-written summary
NaCl at 20–200 mM decreased chlorophyll a and b content in barley relative to untreated control plants.
- Taxon
- barley
.jpg?width=60)
Hordeum vulgaret0 - Treatment
- NaCl solutions (20–200 mM)e0
- Outcome
- chlorophyll (Chl) a and b contente0
- Direction
- decreasede0
- Comparator
- untreated control plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
t0“barley plants”
e0“on NaCl solutions (20–200 mM) decreased chlorophyll (Chl) a and b content with respect to that in untreated control plants”
Claim · model-written summary
Free proline content and ALA synthesis ability in barley started to increase in parallel at 20–50 mM NaCl.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- salt concentrations of 20–50 mMe0
- Outcome
- content of free proline and the plant ability to synthesize 5-aminolevulinic acid (ALA)e0
- Direction
- increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“The content of free proline and the plant ability to synthesize 5-aminolevulinic acid (ALA) started to increase in parallel at salt concentrations of 20–50 mM”
Claim · model-written summary
ALA accumulation in barley grown at 100 mM NaCl was twofold higher than in control plants grown on fresh water.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- 100 mM NaCle0
- Outcome
- maximum amount of ALA accumulatede0
- Direction
- highere0
- Value
- twofolde0
- Comparator
- control plants grown on fresh watere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“The maximum amount of ALA accumulated in plants grown at 100 mM NaCl was twofold higher than in control plants grown on fresh water”
Claim · model-written summary
Reduced ALA synthesis ability in barley was accompanied by higher proline content.
- Taxon
- barleyHordeum vulgaret0
- Compound
- ALAe0
- Outcome
- proline contente0
- Direction
- increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“The reduced ability to synthesize ALA was accompanied by an increase in proline content”
Claim · model-written summary
Albino tissue of barley treated with streptomycin at the seed stage lost its ability to synthesize ALA.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- albino tissuee0
- Treatment
- treated at the seed stage with the antibiotic streptomycine0
- Outcome
- ability to synthesize ALAe0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“The albino tissue of plants treated at the seed stage with the antibiotic streptomycin lost its ability to synthesize ALA needed for Chl formation”
Claim · model-written summary
Proline content in albino barley tissue was tenfold higher than in control green plants.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- albino tissuee0
- Outcome
- proline contente0
- Direction
- highere0
- Value
- tenfolde0
- Comparator
- control green plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“The proline content in the albino tissue was tenfold higher than in control green plants”
Claim · model-written summary
Proline content in albino barley tissue was 30-fold higher when plants were grown on 100 mM NaCl.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- albino tissuee0
- Treatment
- solutions with 100 mM NaCle0
- Outcome
- proline contente0
- Direction
- highere0
- Value
- 30-folde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“The proline content in the albino tissue was tenfold higher than in control green plants and was 30-fold higher when the plants were grown on solutions with 100 mM NaCl”
Claim · model-written summary
NaCl had no effect on ALA-dehydratase activity in barley.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- NaCle0
- Outcome
- ALA-dehydratase activitye0
- Direction
- No effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“No effect of NaCl on ALA-dehydratase activity was noted”
Claim · model-written summary
Magnesium chelatase activity in barley decreased as NaCl concentration was raised.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- NaCl concentration was raisede0
- Outcome
- magnesium chelatase activitye0
- Direction
- decreasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“As NaCl concentration was raised, there occurred the decrease in magnesium chelatase activity”
Claim · model-written summary
Reactive oxygen species accumulated in barley as NaCl concentration was raised.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- NaCl concentration was raisede0
- Outcome
- accumulation of reactive oxygen species (ROS)e1
- Direction
- increaseinferrede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“As NaCl concentration was raised”
e1“accumulation of reactive oxygen species (ROS)”
Claim · model-written summary
Ascorbate peroxidase activity in barley increased as NaCl concentration was raised.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- NaCl concentration was raisede1
- Outcome
- ascorbate peroxidase activitye0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“the increase in ascorbate peroxidase activity”
e1“As NaCl concentration was raised”
Claim · model-written summary
Lipid peroxidation level in barley decreased slightly as NaCl concentration was raised.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- NaCl concentration was raisede1
- Outcome
- lipid peroxidation levele0
- Direction
- decreasee0
- Qualifier
- slighte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“a slight decrease in lipid peroxidation level”
e1“As NaCl concentration was raised”
Claim · model-written summary
At 10 mg/l exogenous ALA with 150 mM NaCl, proline content in barley rose 1.8-fold relative to salt-only plants.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- exogenous ALAe0
- Outcome
- proline contente0
- Direction
- increasee0
- Value
- 1.8e0
- Qualifier
- 150 mM NaCle0
- Comparator
- plants grown on salt solutions without ALAe1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“in the presence of 150 mM NaCl and 10 or 60 mg/l exogenous ALA led to the increase in proline content (by a factor of 1.8 and 4.2, respectively)”
e1“in comparison with plants grown on salt solutions without ALA”
Claim · model-written summary
At 60 mg/l exogenous ALA with 150 mM NaCl, proline content in barley rose 4.2-fold relative to salt-only plants.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- exogenous ALAe0
- Outcome
- proline contente0
- Direction
- increasee0
- Value
- 4.2e0
- Qualifier
- 150 mM NaCle0
- Comparator
- plants grown on salt solutions without ALAe1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“in the presence of 150 mM NaCl and 10 or 60 mg/l exogenous ALA led to the increase in proline content (by a factor of 1.8 and 4.2, respectively)”
e1“in comparison with plants grown on salt solutions without ALA”
Claim · model-written summary
Exogenous ALA with 150 mM NaCl decreased ROS content in barley relative to salt-only plants.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- exogenous ALAe0
- Outcome
- ROS contente2
- Direction
- decreasee2
- Qualifier
- 150 mM NaCle0
- Comparator
- plants grown on salt solutions without ALAe1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“in the presence of 150 mM NaCl and 10 or 60 mg/l exogenous ALA”
e1“in comparison with plants grown on salt solutions without ALA”
e2“the decrease in ROS content”
Claim · model-written summary
Exogenous ALA made seedling growth parameters of barley similar to those of NaCl-untreated plants.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- exogenous ALAe0
- Outcome
- parameters of seedling growthe0
- Direction
- no_changeinferrede0
- Comparator
- NaCl-untreated plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“in the presence of exogenous ALA, the parameters of seedling growth became similar to those of NaCl-untreated plants”
Claim · model-written summary
The authors consider ALA to confer salt tolerance by taking part in chlorophyll and heme biosynthesis.
- Taxon
- barleyHordeum vulgaret0
- Compound
- ALAe0
- Outcome
- tolerance to salt stresse0
- Qualifier
- taking part in Chl and heme biosynthesise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“ALA is supposed to confer tolerance to salt stress by taking part in Chl and heme biosynthesis”
Claim · model-written summary
The authors hypothesise that impaired ALA synthesis may shift glutamic acid metabolism toward proline synthesis in barley.
- Taxon
- barleyHordeum vulgaret0
- Compound
- glutamic acide0
- Outcome
- proline synthesis pathwaye0
- Qualifier
- impairment of ALA-synthesizing abilitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“the impairment of ALA-synthesizing ability may redirect metabolic conversions of glutamic acid from Chl and heme synthesis to the proline synthesis pathway”
Claim · model-written summary
The rate of ALA accumulation in barley decreased at 150 mM NaCl, approaching control values.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- 150 mM NaCle0
- Outcome
- rate of ALA accumulatione0
- Direction
- decreasede0
- Comparator
- control valuese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“the rate of ALA accumulation decreased, approaching control values at 150 mM NaCl”
Claim · model-written summary
The rate of ALA accumulation in barley was even lower at 200 mM NaCl.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- 200 mM NaCle0
- Outcome
- rate of ALA accumulatione1
- Direction
- lowere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley plants”
e0“even lower rates were observed at 200 mM NaCl”
e1“the rate of ALA accumulation”
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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.