Abstract
In shoots of the garden pea, the bioactive gibberellin (GA1) is synthesised from GA20, and the enzyme which catalyses this step (a GA 3-oxidase -- PsGA3ox1) is encoded by Mendel's LE gene. It has been reported previously that decapitation of the shoot (excision of the apical bud) dramatically reduces the conversion of [3H]GA20 to [3H]GA1 in stems, and here we show that endogenous GA1 and PsGA3ox1 transcript levels are similarly reduced. We show also that these effects of decapitation are completely reversed by application of the auxin indole-3-acetic acid (IAA) to the 'stump' of decapitated plants. Gibberellin A20 is also converted to an inactive product, GA29, and this step is catalysed by a GA 2-oxidase, PsGA2ox1. In contrast to PsGA3ox1, PsGA2ox1 transcript levels were increased by decapitation and reduced by IAA application. Decapitation and IAA treatment did not markedly affect the level of GA1 precursors. It is suggested that in intact pea plants, auxin from the apical bud moves into the elongating internodes where it (directly or indirectly) maintains PsGA3ox1 transcript levels and, consequently, GA1 biosynthesis.
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Claims 9
Claim · model-written summary
Decapitation reduced endogenous GA1 in pea stems.
- Taxon
- pea
Lathyrus oleraceust0 - Organ / stage
- stemse0
- Treatment
- decapitation of the shoote0
- Outcome
- endogenous GA1e0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“in pea”
e0“decapitation of the shoot (excision of the apical bud) dramatically reduces the conversion of [3H]GA20 to [3H]GA1 in stems, and here we show that endogenous GA1 and PsGA3ox1 transcript levels are similarly reduced.”
Claim · model-written summary
Decapitation reduced PsGA3ox1 transcript levels.
- Taxon
- peaLathyrus oleraceust0
- Treatment
- decapitatione1
- Gene
- PsGA3ox1e0
- Outcome
- PsGA3ox1 transcript levelse0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“in pea”
e0“endogenous GA1 and PsGA3ox1 transcript levels are similarly reduced.”
e1“decapitation of the shoot (excision of the apical bud) dramatically reduces the conversion of [3H]GA20 to [3H]GA1 in stems”
Claim · model-written summary
IAA application reversed the decapitation associated decline in GA1.
- Taxon
- peaLathyrus oleraceust0
- Organ / stage
- stumpe0
- Treatment
- application of the auxin indole-3-acetic acid (IAA)e0
- Outcome
- effects of decapitatione0
- Direction
- reversede0
- Comparator
- decapitatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“in pea”
e0“these effects of decapitation are completely reversed by application of the auxin indole-3-acetic acid (IAA) to the 'stump' of decapitated plants.”
Claim · model-written summary
IAA application reversed the decapitation associated decline in PsGA3ox1 transcripts.
- Taxon
- peaLathyrus oleraceust0
- Treatment
- application of the auxin indole-3-acetic acid (IAA)e0
- Gene
- PsGA3ox1e0
- Outcome
- PsGA3ox1 transcript levelse0
- Direction
- reversede0
- Comparator
- decapitatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“in pea”
e0“PsGA3ox1 transcript levels are similarly reduced. We show also that these effects of decapitation are completely reversed by application of the auxin indole-3-acetic acid (IAA)”
Claim · model-written summary
Decapitation increased PsGA2ox1 transcript levels.
- Taxon
- peaLathyrus oleraceust0
- Treatment
- decapitatione0
- Gene
- PsGA2ox1e0
- Outcome
- PsGA2ox1 transcript levelse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“in pea”
e0“PsGA2ox1 transcript levels were increased by decapitation and reduced by IAA application.”
Claim · model-written summary
IAA application reduced PsGA2ox1 transcript levels.
- Taxon
- peaLathyrus oleraceust0
- Treatment
- IAA applicatione0
- Gene
- PsGA2ox1e0
- Outcome
- PsGA2ox1 transcript levelse0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“in pea”
e0“PsGA2ox1 transcript levels were increased by decapitation and reduced by IAA application.”
Claim · model-written summary
Decapitation did not markedly affect GA1 precursor levels.
- Taxon
- peaLathyrus oleraceust0
- Treatment
- Decapitatione0
- Outcome
- level of GA1 precursorse0
- Direction
- did not markedly affecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“in pea”
e0“Decapitation and IAA treatment did not markedly affect the level of GA1 precursors.”
Claim · model-written summary
IAA treatment did not markedly affect GA1 precursor levels.
- Taxon
- peaLathyrus oleraceust0
- Treatment
- IAA treatmente0
- Outcome
- level of GA1 precursorse0
- Direction
- did not markedly affecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“in pea”
e0“Decapitation and IAA treatment did not markedly affect the level of GA1 precursors.”
Claim · model-written summary
The authors suggest that bud auxin maintains PsGA3ox1 transcripts and consequently GA1 biosynthesis in elongating internodes.
- Taxon
- peaLathyrus oleraceust0
- Organ / stage
- elongating internodese0
- Gene
- PsGA3ox1e0
- Compound
- auxine0
- Outcome
- GA1 biosynthesise0
- Qualifier
- directly or indirectlye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“in pea”
e0“auxin from the apical bud moves into the elongating internodes where it (directly or indirectly) maintains PsGA3ox1 transcript levels and, consequently, GA1 biosynthesis.”
The same questions in other papers
indole-3-acetic acid · molecular: expression · Lathyrus oleraceus (pea)Positive and negative results
1 paper in the same direction as this paper · 3 in the opposite direction · 1 reporting no difference from an alternative
- negative
- negative
- no effect
2 papers more in this group
See all 6 papers →pruning · molecular: expression · Lathyrus oleraceus (pea)Positive and negative results
2 in the opposite direction
- positive
- positive
class · molecular: expression · Lathyrus oleraceus (pea)Positive and negative results
4 papers in the same direction as this paper · 4 in the opposite direction
- no effect
- no effect
- no effect
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.