Abstract
During ethylene-promoted leaflet abscission in Sambucus nigra a 7-fold increase in expansin activity was detected specifically in tissues undergoing cell separation, whilst only low levels of activity were seen in adjacent non-abscising tissues. An RT-PCR strategy was used to amplify expansin fragments from a cDNA library generated from mRNA extracted from ethylene-treated leaflet abscission-zone tissue. Two different full-length expansin-encoding cDNAs were isolated with sizes of 1190 bp and 1169 bp and named SniExp2 and SniExp4, respectively. The deduced protein sequences of SniExp2 and SniExp4 exhibited 67% homology and comprised 256 and 249 amino acids, respectively. Both putative proteins contained signal sequences at their N terminal ends, suggesting that they were likely to encode secreted or transmembrane proteins. Northern analyses with probes specific for each gene revealed that transcripts for both of these cDNAs accumulated specifically in abscission zone tissues in response to ethylene treatment, with no expression being apparent in either freshly excised material or non-separating tissues. These data support a role for expansins in ethylene-stimulated abscission and provide evidence that specific family members contribute to the cell separation process that takes place during organ shedding.
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Claims 7
Claim · model-written summary
Expansin activity increased sevenfold in separating tissue during ethylene-promoted abscission.
- Taxon
- Sambucus nigra
.jpg?width=60)
Sambucus nigrae0 - Organ / stage
- tissues undergoing cell separatione0
- Treatment
- ethylene-promotede0
- Outcome
- expansin activitye0
- Direction
- increasee0
- Value
- 7-folde0
- Comparator
- adjacent non-abscising tissuese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“During ethylene-promoted leaflet abscission in Sambucus nigra a 7-fold increase in expansin activity was detected specifically in tissues undergoing cell separation, whilst only low levels of activity were seen in adjacent non-abscising tissues”
Claim · model-written summary
Two full-length expansin cDNAs, SniExp2 and SniExp4, were isolated at 1190 and 1169 bp.
- Taxon
- Sambucus nigraSambucus nigrat0
- Gene
- SniExp2 and SniExp4e0
- Outcome
- full-length expansin-encoding cDNAse0
- Value
- 1190 bp and 1169 bpe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Two different full-length expansin-encoding cDNAs were isolated with sizes of 1190 bp and 1169 bp and named SniExp2 and SniExp4, respectively”
t0“Sambucus nigra”
Claim · model-written summary
The deduced SniExp2 and SniExp4 proteins had 67% homology.
- Taxon
- Sambucus nigraSambucus nigrat0
- Gene
- SniExp2 and SniExp4e0
- Outcome
- homologye0
- Value
- 67%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The deduced protein sequences of SniExp2 and SniExp4 exhibited 67% homology”
t0“Sambucus nigra”
Claim · model-written summary
The deduced SniExp2 and SniExp4 proteins contained 256 and 249 amino acids respectively.
- Taxon
- Sambucus nigraSambucus nigrat0
- Gene
- SniExp2 and SniExp4e1
- Outcome
- amino acidse0
- Value
- 256 and 249 amino acidse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“comprised 256 and 249 amino acids, respectively”
e1“protein sequences of SniExp2 and SniExp4”
t0“Sambucus nigra”
Claim · model-written summary
Both putative proteins contained N-terminal signal sequences.
- Taxon
- Sambucus nigraSambucus nigrat0
- Outcome
- signal sequences at their N terminal endse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both putative proteins contained signal sequences at their N terminal ends”
t0“Sambucus nigra”
Claim · model-written summary
SniExp2 and SniExp4 transcripts accumulated specifically in abscission zones after ethylene treatment, with no apparent expression in fresh or non-separating tissues.
- Taxon
- Sambucus nigraSambucus nigrat0
- Organ / stage
- abscission zone tissuese0
- Treatment
- ethylene treatmente0
- Gene
- SniExp2 and SniExp4e1
- Outcome
- transcriptse0
- Direction
- accumulatede0
- Comparator
- freshly excised material or non-separating tissuese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“transcripts for both of these cDNAs accumulated specifically in abscission zone tissues in response to ethylene treatment, with no expression being apparent in either freshly excised material or non-separating tissues”
e1“The deduced protein sequences of SniExp2 and SniExp4”
t0“Sambucus nigra”
Claim · model-written summary
The authors infer a role for expansins in ethylene-stimulated cell separation during abscission.
- Taxon
- Sambucus nigraSambucus nigrat0
- Gene
- expansinse0
- Outcome
- cell separation processe0
- Qualifier
- during organ sheddinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These data support a role for expansins in ethylene-stimulated abscission and provide evidence that specific family members contribute to the cell separation process that takes place during organ shedding”
t0“Sambucus nigra”
The same questions in other papers
ethene · molecular: expression · Sambucus nigra (European elder)Results agree
1 paper in the same direction as this paper
- positive
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.