Abstract
SPINDLY (SPY) is a negative regulator of gibberellin (GA) responses; however, spy mutants exhibit various phenotypic alterations not found in GA-treated plants. Assaying for additional roles for SPY revealed that spy mutants are resistant to exogenously applied cytokinin. GA also repressed the effects of cytokinin, suggesting that there is cross talk between the two hormone-response pathways, which may involve SPY function. Two spy alleles showing severe (spy-4) and mild (spy-3) GA-associated phenotypes exhibited similar resistance to cytokinin, suggesting that SPY enhances cytokinin responses and inhibits GA signaling through distinct mechanisms. GA and spy repressed numerous cytokinin responses, from seedling development to senescence, indicating that cross talk occurs early in the cytokinin-signaling pathway. Because GA3 and spy-4 inhibited induction of the cytokinin primary-response gene, type-A Arabidopsis response regulator 5, SPY may interact with and modify elements from the phosphorelay cascade of the cytokinin signal transduction pathway. Cytokinin, on the other hand, had no effect on GA biosynthesis or responses. Our results demonstrate that SPY acts as both a repressor of GA responses and a positive regulator of cytokinin signaling. Hence, SPY may play a central role in the regulation of GA/cytokinin cross talk during plant development.
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Claims 13
Claim · model-written summary
spy mutants were resistant to externally applied cytokinin.
- Taxon
- Arabidopsis
Arabidopsist0 - Material
- spy mutantse0
- Treatment
- exogenously applied cytokinine0
- Outcome
- resistante0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“spy mutants are resistant to exogenously applied cytokinin.”
t0“Arabidopsis”
Claim · model-written summary
GA repressed cytokinin effects, suggesting cross talk possibly involving SPY.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- GAe0
- Outcome
- effects of cytokinine0
- Direction
- repressede0
- Qualifier
- may involve SPY functione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GA also repressed the effects of cytokinin, suggesting that there is cross talk between the two hormone-response pathways, which may involve SPY function.”
t0“Arabidopsis”
Claim · model-written summary
spy-4 showed cytokinin resistance similar to spy-3 despite different severity of GA-associated phenotypes.
- Taxon
- ArabidopsisArabidopsist0
- Material
- spy-4e0
- Outcome
- resistance to cytokinine0
- Direction
- similare0
- Qualifier
- GA-associated phenotypese0
- Comparator
- spy-3e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Two spy alleles showing severe (spy-4) and mild (spy-3) GA-associated phenotypes exhibited similar resistance to cytokinin”
t0“Arabidopsis”
Claim · model-written summary
SPY appeared to enhance cytokinin responses and inhibit GA signaling by distinct mechanisms.
- Taxon
- ArabidopsisArabidopsist0
- Gene
- SPYe0
- Outcome
- cytokinin responsese0
- Direction
- enhancese0
- Qualifier
- distinct mechanismse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“suggesting that SPY enhances cytokinin responses and inhibits GA signaling through distinct mechanisms.”
t0“Arabidopsis”
Claim · model-written summary
SPY inhibited GA signaling through mechanisms distinct from enhancement of cytokinin responses.
- Taxon
- ArabidopsisArabidopsist0
- Gene
- SPYe0
- Outcome
- GA signalinge0
- Direction
- inhibitse0
- Qualifier
- distinct mechanismse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“suggesting that SPY enhances cytokinin responses and inhibits GA signaling through distinct mechanisms.”
t0“Arabidopsis”
Claim · model-written summary
GA repressed cytokinin responses from seedling development to senescence.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- GAe0
- Outcome
- cytokinin responsese0
- Direction
- repressede0
- Qualifier
- from seedling development to senescencee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GA and spy repressed numerous cytokinin responses, from seedling development to senescence, indicating that cross talk occurs early in the cytokinin-signaling pathway.”
t0“Arabidopsis”
Claim · model-written summary
spy repressed cytokinin responses from seedling development to senescence.
- Taxon
- ArabidopsisArabidopsist0
- Material
- spye0
- Outcome
- cytokinin responsese0
- Direction
- repressede0
- Qualifier
- from seedling development to senescencee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GA and spy repressed numerous cytokinin responses, from seedling development to senescence, indicating that cross talk occurs early in the cytokinin-signaling pathway.”
t0“Arabidopsis”
Claim · model-written summary
Cross talk appeared to occur early in cytokinin signaling.
- Taxon
- ArabidopsisArabidopsist0
- Outcome
- cross talke0
- Qualifier
- early in the cytokinin-signaling pathwaye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“indicating that cross talk occurs early in the cytokinin-signaling pathway.”
t0“Arabidopsis”
Claim · model-written summary
GA3 inhibited induction of type-A Arabidopsis response regulator 5.
- Taxon
- ArabidopsisArabidopsise0
- Treatment
- GA3e0
- Gene
- type-A Arabidopsis response regulator 5e0
- Outcome
- inductione0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Because GA3 and spy-4 inhibited induction of the cytokinin primary-response gene, type-A Arabidopsis response regulator 5”
Claim · model-written summary
spy-4 inhibited induction of type-A Arabidopsis response regulator 5.
- Taxon
- ArabidopsisArabidopsise0
- Material
- spy-4e0
- Gene
- type-A Arabidopsis response regulator 5e0
- Outcome
- inductione0
- Direction
- inhibitede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Because GA3 and spy-4 inhibited induction of the cytokinin primary-response gene, type-A Arabidopsis response regulator 5”
Claim · model-written summary
SPY may interact with and modify phosphorelay components in cytokinin signal transduction.
- Taxon
- ArabidopsisArabidopsist0
- Gene
- SPYe0
- Outcome
- interact with and modify elementse0
- Qualifier
- phosphorelay cascade of the cytokinin signal transduction pathwaye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“SPY may interact with and modify elements from the phosphorelay cascade of the cytokinin signal transduction pathway.”
t0“Arabidopsis”
Claim · model-written summary
Cytokinin did not affect GA biosynthesis or responses.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- Cytokinine0
- Outcome
- GA biosynthesis or responsese0
- Direction
- no effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cytokinin, on the other hand, had no effect on GA biosynthesis or responses.”
t0“Arabidopsis”
Claim · model-written summary
SPY may centrally regulate GA/cytokinin cross talk during development.
- Taxon
- ArabidopsisArabidopsist0
- Gene
- SPYe0
- Outcome
- regulation of GA/cytokinin cross talke0
- Qualifier
- during plant developmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“SPY may play a central role in the regulation of GA/cytokinin cross talk during plant development.”
t0“Arabidopsis”
The same questions in other papers
class · molecular: metabolites · ArabidopsisPositive and negative results
4 papers in the same direction as this paper · 7 in the opposite direction
- positive
- positive
- positive
8 papers more in this group
See all 12 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.