Abstract
Nitric oxide (NO) is an important signaling molecule involved in many physiological processes in plants. We evaluated the role of NO in cold acclimation and freezing tolerance using Arabidopsis (Arabidopsis thaliana) wild type and mutants nia1nia2 (for nitrate reductase [NR]-defective double mutant) and Atnoa1/rif1 (for nitric oxide associated1/resistant to inhibition by fosmidomycin1) that exhibit defects in NR and reduced NO production, respectively. Cold acclimation induced an increase in endogenous NO production in wild-type and Atnoa1/rif1 leaves, while endogenous NO level in nia1nia2 leaves was lower than in wild-type ones and was little changed during cold acclimation. Cold acclimation stimulated NR activity and induced up-regulation of NIA1 gene expression. In contrast, cold acclimation reduced the quantity of NOA1/RIF1 protein and inhibited NO synthase (NOS) activity. These results indicate that up-regulation of NR-dependent NO synthesis underpins cold acclimation-induced NO production. Seedlings of nia1nia2 were less tolerant to freezing than wild-type plants. Pharmacological studies using NR inhibitor, NO scavenger, and NO donor showed that NR-dependent NO level was positively correlated with freezing tolerance. Furthermore, cold acclimation up- and down-regulated expression of P5CS1 and ProDH genes, respectively, resulting in enhanced accumulation of proline (Pro) in wild-type plants. The stimulation of Pro accumulation by cold acclimation was reduced by NR inhibitor and NO scavenger, while Pro accumulation by cold acclimation was not affected by the NOS inhibitor. In contrast to wild-type plants, cold acclimation up-regulated ProDH gene expression in nia1nia2 plants, leading to less accumulation in nia1nia2 plants than in wild-type plants. These findings demonstrate that NR-dependent NO production plays an important role in cold acclimation-induced increase in freezing tolerance by modulating Pro accumulation in Arabidopsis.
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Claims 18
Claim · model-written summary
Cold acclimation increased endogenous NO production in wild-type and Atnoa1/rif1 Arabidopsis leaves.
- Taxon
- Arabidopsis
Arabidopsist0 - Material
- wild-type and Atnoa1/rif1e1
- Organ / stage
- leavese1
- Treatment
- Cold acclimatione1
- Outcome
- endogenous NO productione1
- Direction
- increasee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“Cold acclimation induced an increase in endogenous NO production in wild-type and Atnoa1/rif1 leaves”
Claim · model-written summary
Endogenous NO level in nia1nia2 leaves was lower than in wild-type Arabidopsis.
- Taxon
- ArabidopsisArabidopsist0
- Material
- nia1nia2e2
- Organ / stage
- leavese2
- Outcome
- endogenous NO levele2
- Direction
- lowere2
- Comparator
- wild-type onese2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e2“endogenous NO level in nia1nia2 leaves was lower than in wild-type ones”
Claim · model-written summary
Endogenous NO level in nia1nia2 leaves was little changed during cold acclimation.
- Taxon
- ArabidopsisArabidopsist0
- Material
- nia1nia2e2
- Treatment
- cold acclimatione3
- Outcome
- endogenous NO levele2
- Direction
- little changede3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e2“endogenous NO level in nia1nia2 leaves was lower than in wild-type ones”
e3“was little changed during cold acclimation”
Claim · model-written summary
Cold acclimation stimulated nitrate reductase (NR) activity in Arabidopsis.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- Cold acclimatione1
- Outcome
- NR activitye1
- Direction
- stimulatede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“Cold acclimation stimulated NR activity”
Claim · model-written summary
Cold acclimation up-regulated NIA1 gene expression in Arabidopsis.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- Cold acclimatione1
- Gene
- NIA1e2
- Outcome
- gene expressione2
- Direction
- up-regulatione2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“Cold acclimation stimulated NR activity”
e2“induced up-regulation of NIA1 gene expression”
Claim · model-written summary
Cold acclimation reduced the quantity of NOA1/RIF1 protein in Arabidopsis.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- cold acclimatione1
- Gene
- NOA1/RIF1e1
- Outcome
- quantity of NOA1/RIF1 proteine1
- Direction
- reducede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“In contrast, cold acclimation reduced the quantity of NOA1/RIF1 protein and inhibited NO synthase (NOS) activity”
Claim · model-written summary
Cold acclimation inhibited NO synthase (NOS) activity in Arabidopsis.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- cold acclimatione1
- Gene
- NO synthase (NOS)e2
- Outcome
- NO synthase (NOS) activitye2
- Direction
- inhibitede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“In contrast, cold acclimation reduced the quantity of NOA1/RIF1 protein and inhibited NO synthase (NOS) activity”
e2“inhibited NO synthase (NOS) activity”
Claim · model-written summary
Up-regulation of NR-dependent NO synthesis is asserted to underpin cold acclimation-induced NO production in Arabidopsis.
- Taxon
- ArabidopsisArabidopsist0
- Outcome
- cold acclimation-induced NO productione1
- Qualifier
- up-regulation of NR-dependent NO synthesise1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“up-regulation of NR-dependent NO synthesis underpins cold acclimation-induced NO production”
Claim · model-written summary
Seedlings of nia1nia2 were less tolerant to freezing than wild-type Arabidopsis plants.
- Taxon
- ArabidopsisArabidopsist0
- Material
- nia1nia2e1
- Organ / stage
- Seedlingse1
- Outcome
- tolerant to freezinge1
- Direction
- lesse1
- Comparator
- wild-type plantse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“Seedlings of nia1nia2 were less tolerant to freezing than wild-type plants”
Claim · model-written summary
NR-dependent NO level was positively correlated with freezing tolerance in Arabidopsis.
- Taxon
- ArabidopsisArabidopsist0
- Compound
- NR-dependent NO levele1
- Outcome
- freezing tolerancee1
- Direction
- positively correlatede1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“NR-dependent NO level was positively correlated with freezing tolerance”
Claim · model-written summary
Cold acclimation increased P5CS1 gene expression in Arabidopsis.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- cold acclimatione1
- Gene
- P5CS1e1
- Outcome
- expressione1
- Direction
- increaseinferrede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“cold acclimation up- and down-regulated expression of P5CS1 and ProDH genes, respectively”
Claim · model-written summary
Cold acclimation decreased ProDH gene expression in Arabidopsis.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- cold acclimatione1
- Gene
- ProDHe1
- Outcome
- expressione1
- Direction
- decreaseinferrede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“cold acclimation up- and down-regulated expression of P5CS1 and ProDH genes, respectively”
Claim · model-written summary
Cold acclimation enhanced proline (Pro) accumulation in wild-type Arabidopsis plants.
- Taxon
- ArabidopsisArabidopsist0
- Material
- wild-type plantse2
- Treatment
- cold acclimatione1
- Compound
- proline (Pro)e2
- Outcome
- accumulatione2
- Direction
- enhancede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“cold acclimation up- and down-regulated expression of P5CS1 and ProDH genes, respectively”
e2“resulting in enhanced accumulation of proline (Pro) in wild-type plants”
Claim · model-written summary
NR inhibitor and NO scavenger reduced the stimulation of Pro accumulation by cold acclimation in Arabidopsis.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- NR inhibitor and NO scavengere1
- Compound
- Proe1
- Outcome
- stimulation of Pro accumulation by cold acclimatione1
- Direction
- reducede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“The stimulation of Pro accumulation by cold acclimation was reduced by NR inhibitor and NO scavenger”
Claim · model-written summary
The NOS inhibitor did not affect Pro accumulation by cold acclimation in Arabidopsis.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- NOS inhibitore1
- Compound
- Proe1
- Outcome
- Pro accumulation by cold acclimatione1
- Direction
- not affectede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“Pro accumulation by cold acclimation was not affected by the NOS inhibitor”
Claim · model-written summary
Cold acclimation increased ProDH gene expression in nia1nia2 plants.
- Taxon
- ArabidopsisArabidopsist0
- Material
- nia1nia2e1
- Treatment
- cold acclimatione1
- Gene
- ProDHe1
- Outcome
- gene expressione1
- Direction
- increaseinferrede1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“cold acclimation up-regulated ProDH gene expression in nia1nia2 plants”
Claim · model-written summary
nia1nia2 plants accumulated less proline (Pro) than wild-type plants after cold acclimation.
- Taxon
- ArabidopsisArabidopsist0
- Material
- nia1nia2e1
- Outcome
- accumulatione1
- Direction
- lesse1
- Comparator
- wild-type plantse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“leading to less accumulation in nia1nia2 plants than in wild-type plants”
Claim · model-written summary
NR-dependent NO production is asserted to play an important role in the cold acclimation-induced increase in freezing tolerance by modulating Pro accumulation in Arabidopsis.
- Taxon
- ArabidopsisArabidopsist0
- Compound
- NR-dependent NOe1
- Outcome
- freezing tolerancee1
- Qualifier
- modulating Pro accumulatione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Freezing Tolerance in Arabidopsis”
e1“NR-dependent NO production plays an important role in cold acclimation-induced increase in freezing tolerance by modulating Pro accumulation”
The same questions in other papers
nitric oxide · molecular: metabolites · ArabidopsisPositive and negative results
3 papers in the same direction as this paper · 5 in the opposite direction
- positive
- positive
- positive
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.