Abstract
Stem segments excised from light‐grown Pisum sativum L. (cv. Little Marvel) plants elongated in the presence of indole‐3‐acetic acid and its precursors, except for L‐tryptophan, which required the addition of gibberellin A, for induction of growth. Segment elongation was promoted by D‐tryptophan without a requirement for gibberellin, and growth in the presence of both D‐tryptophan and L‐tryptophan with gibberellin A3, was inhibited by the D‐aminotransferase inhibitor D‐cycloserine. Tryp‐tophan racemase activity was detected in apices and promoted conversion of L‐tryptophan to the D isomer; this activity was enhanced by gibberellin A3. When applied to apices of intact untreated plants, radiolabeled D‐tryptophan was converted to indole‐3‐acetic acid and indoleacetylaspartic acid much more readily than L‐tryptophan. Treatment of plants with gibberellin A3, 3 days prior to application of labeled tryptophan increased conversion of L‐tryptophan to the free auxin and its conjugate by more than 3‐fold, and led to labeling of N‐malonyl‐D‐tryptophan. It is proposed that gibberellin increases the biosynthesis of indole‐3‐acetic acid by regulating the conversion of L‐tryptophan to D‐tryptophan, which is then converted to the auxin.
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Claims 9
Claim · model-written summary
Stem segments elongated with indole acetic acid and its precursors except L-tryptophan.
- Taxon
- Pisum sativum L.
Lathyrus oleraceuse0 - Treatment
- indole‐3‐acetic acid and its precursorse0
- Outcome
- elongatede0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Stem segments excised from light‐grown Pisum sativum L. (cv. Little Marvel) plants elongated in the presence of indole‐3‐acetic acid and its precursors, except for L‐tryptophan”
Claim · model-written summary
Gibberellin enabled L-tryptophan-induced growth.
- Taxon
- Pisum sativum L.Lathyrus oleraceuse1
- Treatment
- addition of gibberellin Ae0
- Outcome
- induction of growthe0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“L‐tryptophan, which required the addition of gibberellin A, for induction of growth”
t0“Gibberellin‐enhanced indole‐3‐acetic acid biosynthesis”
e1“Pisum sativum L.”
Claim · model-written summary
D-tryptophan promoted stem elongation without gibberellin.
- Taxon
- Pisum sativum L.Lathyrus oleraceuse1
- Treatment
- D‐tryptophane0
- Outcome
- Segment elongatione0
- Direction
- promotede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Segment elongation was promoted by D‐tryptophan without a requirement for gibberellin”
t0“Gibberellin‐enhanced indole‐3‐acetic acid biosynthesis”
e1“Pisum sativum L.”
Claim · model-written summary
D-cycloserine inhibited growth with tryptophan and gibberellin.
- Taxon
- Pisum sativum L.Lathyrus oleraceuse1
- Treatment
- D‐cycloserinee0
- Gene
- D‐aminotransferasee0
- Outcome
- growthe0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growth in the presence of both D‐tryptophan and L‐tryptophan with gibberellin A3, was inhibited by the D‐aminotransferase inhibitor D‐cycloserine”
t0“Gibberellin‐enhanced indole‐3‐acetic acid biosynthesis”
e1“Pisum sativum L.”
Claim · model-written summary
Tryptophan racemase activity in apices converted L-tryptophan to D-tryptophan.
- Taxon
- Pisum sativum L.Lathyrus oleraceuse1
- Organ / stage
- apicese0
- Gene
- Tryp‐tophan racemasee0
- Outcome
- conversion of L‐tryptophan to the D isomere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Tryp‐tophan racemase activity was detected in apices and promoted conversion of L‐tryptophan to the D isomer”
t0“Gibberellin‐enhanced indole‐3‐acetic acid biosynthesis”
e1“Pisum sativum L.”
Claim · model-written summary
Gibberellin enhanced racemase activity.
- Taxon
- Pisum sativum L.Lathyrus oleraceuse1
- Treatment
- gibberellin A3e0
- Outcome
- activitye0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“this activity was enhanced by gibberellin A3”
t0“Gibberellin‐enhanced indole‐3‐acetic acid biosynthesis”
e1“Pisum sativum L.”
Claim · model-written summary
D-tryptophan was converted to auxin and its conjugate more readily than L-tryptophan.
- Taxon
- Pisum sativum L.Lathyrus oleraceuse1
- Outcome
- converted to indole‐3‐acetic acid and indoleacetylaspartic acide0
- Direction
- much more readilye0
- Comparator
- L‐tryptophane0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“radiolabeled D‐tryptophan was converted to indole‐3‐acetic acid and indoleacetylaspartic acid much more readily than L‐tryptophan”
t0“Gibberellin‐enhanced indole‐3‐acetic acid biosynthesis”
e1“Pisum sativum L.”
Claim · model-written summary
Gibberellin pretreatment raised conversion of L-tryptophan to auxin and conjugate over threefold.
- Taxon
- Pisum sativum L.Lathyrus oleraceuse1
- Treatment
- gibberellin A3e0
- Outcome
- conversion of L‐tryptophan to the free auxin and its conjugatee0
- Direction
- increasede0
- Value
- more than 3‐folde0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatment of plants with gibberellin A3, 3 days prior to application of labeled tryptophan increased conversion of L‐tryptophan to the free auxin and its conjugate by more than 3‐fold”
t0“Gibberellin‐enhanced indole‐3‐acetic acid biosynthesis”
e1“Pisum sativum L.”
Claim · model-written summary
Gibberellin pretreatment yielded labeled N-malonyl-D-tryptophan.
- Taxon
- Pisum sativum L.Lathyrus oleraceuse1
- Outcome
- labeling of N‐malonyl‐D‐tryptophane0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“and led to labeling of N‐malonyl‐D‐tryptophan”
t0“Gibberellin‐enhanced indole‐3‐acetic acid biosynthesis”
e1“Pisum sativum L.”
The same questions in other papers
gibberellin A3 · physiology: hormones · Lathyrus oleraceus (pea)Results agree
2 papers in the same direction as this paper
- 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.