Abstract
SUMMARY Distribution of radioactivity from [3H] GA1 and [14C] IAA within the tissues of isolated 2.5 or 3 cm long segments cut from the first internodes of sunflower seedlings was unaffected by displacement from a vertical to horizontal position. This was true whether the agar donor blocks were applied uniformly across the apical cut end of the segments, or where asymmetric donors were used. Neither downward nor upward lateral transport of gibberellin or auxin was influenced. Similarly, use of a lateral donor technique failed to reveal any effect of gravity upon transport across the stem segment to a lateral agar receiver block on the opposite flank. Experiments on etiolated Zea mays coleoptile segments confirmed the existence in this organ of gravity-induced lateral transport of [14C] IAA. No growth curvatures occurred in upright sunflower stem segments incubated with GA1 or GA3 apical donor blocks applied uniformly or asymmetrically, although elongation growth was enhanced. Horizontally positioned segments exhibited only very weak negative geotropic curvatures when in contact with plain agar blocks, but [3H] GA1 (Z X 1O-6M) donors induced marked curvatures when applied either uniformly or asymmetrically to the apical ends. Asymmetric donor blocks containing IAA induced growth curvatures in both upright and horizontal stem segments. It is concluded that the mechanism of geotropic response in sunflower stems is likely to involve the participation of both auxin and gibberellin, but that these experiments do not suggest that lateral displacement of these hormones is part of such a mechanism. Differences in levels of endogenous gibberellins that are correlated with direction of geotropic curvature may be a consequence of preferential hormone synthesis or transport in the lower or upper sides of horizontally positioned orthogeotropic organs.
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Claims 12
Claim · model-written summary
Displacement from vertical to horizontal did not change the distribution of radioactivity from [3H] GA1 and [14C] IAA within the stem segments.
- Taxon
- HELIANTHUS ANNUUS
Helianthus annuust0 - Organ / stage
- first internodese1
- Treatment
- displacement from a vertical to horizontal positione1
- Outcome
- Distribution of radioactivity from [3H] GA1 and [14C] IAA within the tissuese1
- Direction
- unaffectede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“FROM HELIANTHUS ANNUUS”
e1“Distribution of radioactivity from [3H] GA1 and [14C] IAA within the tissues of isolated 2.5 or 3 cm long segments cut from the first internodes of sunflower seedlings was unaffected by displacement from a vertical to horizontal position”
Claim · model-written summary
Downward and upward lateral transport of gibberellin or auxin was not influenced by horizontal displacement.
- Taxon
- HELIANTHUS ANNUUSHelianthus annuust0
- Treatment
- displacement from a vertical to horizontal positione1
- Outcome
- lateral transport of gibberellin or auxine2
- Direction
- no_changeinferrede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“FROM HELIANTHUS ANNUUS”
e1“was unaffected by displacement from a vertical to horizontal position”
e2“Neither downward nor upward lateral transport of gibberellin or auxin was influenced”
Claim · model-written summary
Use of a lateral donor technique revealed no effect of gravity on transport across the stem segment.
- Taxon
- HELIANTHUS ANNUUSHelianthus annuust0
- Treatment
- gravitye3
- Outcome
- transport across the stem segmente3
- Direction
- no_changeinferrede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“FROM HELIANTHUS ANNUUS”
e3“use of a lateral donor technique failed to reveal any effect of gravity upon transport across the stem segment”
Claim · model-written summary
Gravity-induced lateral transport of [14C] IAA was confirmed in etiolated Zea mays coleoptile segments.
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Experiments on etiolated Zea mays coleoptile segments confirmed the existence in this organ of gravity-induced lateral transport of [14C] IAA”
Claim · model-written summary
No growth curvatures occurred in upright sunflower stem segments incubated with GA1 or GA3 apical donor blocks.
- Taxon
- HELIANTHUS ANNUUSHelianthus annuust0
- Treatment
- GA1 or GA3 apical donor blockse5
- Outcome
- growth curvaturese5
- Qualifier
- upright sunflower stem segmentse5
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“FROM HELIANTHUS ANNUUS”
e5“No growth curvatures occurred in upright sunflower stem segments incubated with GA1 or GA3 apical donor blocks applied uniformly or asymmetrically”
Claim · model-written summary
GA1 or GA3 apical donor blocks enhanced elongation growth of upright stem segments.
- Taxon
- HELIANTHUS ANNUUSHelianthus annuust0
- Treatment
- GA1 or GA3 apical donor blockse5
- Outcome
- elongation growthe6
- Direction
- enhancede6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“FROM HELIANTHUS ANNUUS”
e5“No growth curvatures occurred in upright sunflower stem segments incubated with GA1 or GA3 apical donor blocks applied uniformly or asymmetrically”
e6“although elongation growth was enhanced”
Claim · model-written summary
Horizontally positioned segments in contact with plain agar blocks showed only very weak negative geotropic curvatures.
- Taxon
- HELIANTHUS ANNUUSHelianthus annuust0
- Treatment
- plain agar blockse7
- Outcome
- geotropic curvaturese7
- Qualifier
- very weak negativee7
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“FROM HELIANTHUS ANNUUS”
e7“Horizontally positioned segments exhibited only very weak negative geotropic curvatures when in contact with plain agar blocks”
Claim · model-written summary
GA1 donor blocks induced marked curvatures in horizontal segments, compared with plain agar blocks.
- Taxon
- HELIANTHUS ANNUUSHelianthus annuust0
- Treatment
- [3H] GA1 (Z X 1O-6M) donorse6
- Outcome
- curvaturese6
- Direction
- inducede6
- Qualifier
- markede6
- Comparator
- plain agar blockse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“FROM HELIANTHUS ANNUUS”
e7“Horizontally positioned segments exhibited only very weak negative geotropic curvatures when in contact with plain agar blocks”
e6“[3H] GA1 (Z X 1O-6M) donors induced marked curvatures when applied either uniformly or asymmetrically to the apical ends”
Claim · model-written summary
Asymmetric donor blocks containing IAA induced growth curvatures in both upright and horizontal stem segments.
- Taxon
- HELIANTHUS ANNUUSHelianthus annuust0
- Treatment
- Asymmetric donor blocks containing IAAe1
- Outcome
- growth curvaturese1
- Direction
- inducede1
- Qualifier
- in both upright and horizontal stem segmentse1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“FROM HELIANTHUS ANNUUS”
e1“Asymmetric donor blocks containing IAA induced growth curvatures in both upright and horizontal stem segments”
Claim · model-written summary
The geotropic response of sunflower stems is likely to involve both auxin and gibberellin.
- Taxon
- HELIANTHUS ANNUUSHelianthus annuust0
- Compound
- auxin and gibberelline1
- Outcome
- mechanism of geotropic response in sunflower stemse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“FROM HELIANTHUS ANNUUS”
e1“It is concluded that the mechanism of geotropic response in sunflower stems is likely to involve the participation of both auxin and gibberellin”
Claim · model-written summary
These experiments do not suggest that lateral displacement of these hormones is part of the geotropic mechanism.
- Taxon
- HELIANTHUS ANNUUSHelianthus annuust0
- Outcome
- lateral displacement of these hormonese1
- Qualifier
- these experiments do not suggeste1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“FROM HELIANTHUS ANNUUS”
e1“these experiments do not suggest that lateral displacement of these hormones is part of such a mechanism”
Claim · model-written summary
Differences in endogenous gibberellin levels are correlated with the direction of geotropic curvature.
- Taxon
- HELIANTHUS ANNUUSHelianthus annuust0
- Compound
- gibberellinse1
- Outcome
- levels of endogenous gibberellinse1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“FROM HELIANTHUS ANNUUS”
e1“Differences in levels of endogenous gibberellins that are correlated with direction of geotropic curvature”
The same questions in other papers
Gibberellic acid · growth · Helianthus annuus (common sunflower)Positive and negative results
1 paper in the same direction as this paper · 13 in the opposite direction
- positive
- positive
- positive
11 papers more in this group
See all 15 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.