Abstract
The regulation by phytochrome of stem elongation in light‐grown plants depends on gibberellins (GAs). To investigate whether this is mediated by a change in GA metabolism, the effect of the GA biosynthesis inhibitor LAB 198 999 (an acylcyclohexadione derivative) on the end‐of‐day far‐red (FR) response in cowpea ( Vigna sinensis L.) epicotyl explants has been investigated. Growth of epicotyl explants of light‐grown seedlings was enhanced when treated with far‐red light before incubation in the dark (end‐of‐day FR effect). Low doses of LAB 198 999 (0.05 and 0.5 μg explant −1 ) reduced the effect of FR, whereas 5 to 50 μg explant −1 stimulated elongation of both red light (R)‐ and FR‐treated epicotyl explants while nullifying the differences between R and FR treatments. In paclobutrazol‐treated epicotyl explants, FR enhanced the response to applied GA 1 and GA 20 , whereas LAB 198 999 increased the activity of GA 1 and decreased that of GA 20 , [ 3 H]Gibberellin A 1 , injected into the basal part of the epicotyl, was transported and metabolized mainly to [ 3 H]GA 8 in the apical 20 mm of the epicotyl. The conversion of [ 3 H]GA 1 to [ 3 H]GA 8 was dramatically reduced by both end‐of‐day FR treatments and LAB 198 999 applications. In addition, both treatments enhanced epicotyl elongation. It is proposed that the regulation of cowpea epicotyl growth by phytocrome is mediated, at least partially, by modifying GA 1 degradation.
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Claims 11
Claim · model-written summary
End-of-day far-red light enhanced epicotyl explant growth.
- Taxon
- cowpea
Vigna unguiculatae1 - Organ / stage
- epicotyl explantse0
- Treatment
- far‐red lighte0
- Outcome
- Growth of epicotyl explantse0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Growth of epicotyl explants of light‐grown seedlings was enhanced when treated with far‐red light before incubation in the dark (end‐of‐day FR effect).”
e1“cowpea ( Vigna sinensis L.)”
Claim · model-written summary
Low doses of LAB 198 999 reduced the far-red effect.
- Taxon
- cowpeaVigna unguiculatae1
- Treatment
- LAB 198 999 (0.05 and 0.5 μg explant −1 )e0
- Outcome
- effect of FRe0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Low doses of LAB 198 999 (0.05 and 0.5 μg explant −1 ) reduced the effect of FR”
e1“cowpea ( Vigna sinensis L.)”
Claim · model-written summary
Higher LAB 198 999 doses stimulated elongation under red and far-red light.
- Taxon
- cowpeaVigna unguiculatae2
- Treatment
- LAB 198 999e1
- Outcome
- elongation of both red light (R)‐ and FR‐treated epicotyl explantse0
- Direction
- stimulatede0
- Value
- 5 to 50 μg explant −1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“5 to 50 μg explant −1 stimulated elongation of both red light (R)‐ and FR‐treated epicotyl explants”
e1“GA biosynthesis inhibitor LAB 198 999”
e2“cowpea ( Vigna sinensis L.)”
Claim · model-written summary
Higher LAB 198 999 doses eliminated elongation differences between red and far-red treatments.
- Taxon
- cowpeaVigna unguiculatae3
- Treatment
- LAB 198 999e2
- Outcome
- differences between R and FR treatmentse0
- Direction
- nullifyinge0
- Comparator
- R and FR treatmentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“nullifying the differences between R and FR treatments”
e1“5 to 50 μg explant −1 stimulated elongation”
e2“GA biosynthesis inhibitor LAB 198 999”
e3“cowpea ( Vigna sinensis L.)”
Claim · model-written summary
Far-red light enhanced response to applied GA 1 and GA 20 in paclobutrazol-treated explants.
- Taxon
- cowpeaVigna unguiculatae1
- Treatment
- FRe0
- Outcome
- response to applied GA 1 and GA 20e0
- Direction
- enhancede0
- Qualifier
- paclobutrazol‐treated epicotyl explantse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In paclobutrazol‐treated epicotyl explants, FR enhanced the response to applied GA 1 and GA 20”
e1“cowpea ( Vigna sinensis L.)”
Claim · model-written summary
LAB 198 999 increased GA 1 activity.
- Taxon
- cowpeaVigna unguiculatae1
- Treatment
- LAB 198 999e0
- Outcome
- activity of GA 1e0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“LAB 198 999 increased the activity of GA 1 and decreased that of GA 20”
e1“cowpea ( Vigna sinensis L.)”
Claim · model-written summary
LAB 198 999 decreased GA 20 activity.
- Taxon
- cowpeaVigna unguiculatae1
- Treatment
- LAB 198 999e0
- Outcome
- GA 20e0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“LAB 198 999 increased the activity of GA 1 and decreased that of GA 20”
e1“cowpea ( Vigna sinensis L.)”
Claim · model-written summary
Injected gibberellin A 1 was transported and chiefly converted to GA 8 in the apical 20 mm.
- Taxon
- cowpeaVigna unguiculatae1
- Organ / stage
- epicotyle0
- Outcome
- transported and metabolized mainly to [ 3 H]GA 8e0
- Qualifier
- apical 20 mme0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“[ 3 H]Gibberellin A 1 , injected into the basal part of the epicotyl, was transported and metabolized mainly to [ 3 H]GA 8 in the apical 20 mm of the epicotyl.”
e1“cowpea ( Vigna sinensis L.)”
Claim · model-written summary
End-of-day far-red light dramatically reduced GA 1 to GA 8 conversion.
- Taxon
- cowpeaVigna unguiculatae1
- Treatment
- end‐of‐day FR treatmentse0
- Outcome
- conversion of [ 3 H]GA 1 to [ 3 H]GA 8e0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The conversion of [ 3 H]GA 1 to [ 3 H]GA 8 was dramatically reduced by both end‐of‐day FR treatments and LAB 198 999 applications.”
e1“cowpea ( Vigna sinensis L.)”
Claim · model-written summary
LAB 198 999 dramatically reduced GA 1 to GA 8 conversion.
- Taxon
- cowpeaVigna unguiculatae1
- Treatment
- LAB 198 999 applicationse0
- Outcome
- conversion of [ 3 H]GA 1 to [ 3 H]GA 8e0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The conversion of [ 3 H]GA 1 to [ 3 H]GA 8 was dramatically reduced by both end‐of‐day FR treatments and LAB 198 999 applications.”
e1“cowpea ( Vigna sinensis L.)”
Claim · model-written summary
Phytochrome regulation of cowpea epicotyl growth may partly act through GA 1 degradation.
- Taxon
- cowpeaVigna unguiculatae0
- Outcome
- cowpea epicotyl growthe0
- Qualifier
- modifying GA 1 degradatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It is proposed that the regulation of cowpea epicotyl growth by phytocrome is mediated, at least partially, by modifying GA 1 degradation.”
The same questions in other papers
light · growth · Vigna unguiculata (cowpea)Positive and negative results
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- positive
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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.