Abstract
A method of growing Avena seedlings is described, which allows them to be handled individually in darkness. Mesocotyls of seedlinge from which the tip of the coleoptile is repeatedly removed are as long as those of control plants not so decapitated. Mesocotyls of seedlings which are deseeded on the 3rd day of growth, followed by decapitation of the cleoptile tip on the 4th day, are, at 7 days old, as long as those of controls not so decapitated. When deseeded plants are decapitated, regeneration of auxin production occurs at the tip of the coleoptile stump. Where a reduction in the length of the mesocotyl results from decapitation, a wound reaction is probably concerned in addition to any auxin changes. Removal of the coleoptilar node causes a sharp decrease in the final length of the mesocotyl. Heating intact seedlings at 40° C. for 3 hours causes a reduction in the length of the mesocotyl but not of the coleoptile. The effect of heating is not reversed by subsequent treatment at low temperature, which instead appears to augment these effects. When seedlings are exposed to the action of KCN, iodoacetate, or anaerobic conditions, and illuminated while so exposed, perception of light takes place, resulting in a reduction in the length of the mesocotyl. Perception of light takes place in seedlings germinated at normal temperatures, but maintained at low temprature during illumination and also in seedlings grown for 6 weeks at 2° C. without any previous growth at normal temperature. Light perception takes place in embryos excised from dry grain and grown on a culture medium. No difference in free amino-acid content is apparent between dark grown and illuminated seedlings. The effects of illumination survive a period of drying down and become apparent upon subsequent germination of the grain in darkness. The drying process itself causes an additional reduction in mesocotyl length. It is concluded that auxin itself is not the primary reactant in the perception process, and that the growth of the mesocotyl is probably controlled by the coleoptilar node and plumular growing point, rather than by auxin diffusing downward from the tip of the coleoptile.
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Claims 17
Claim · model-written summary
Mesocotyls of seedlings whose coleoptile tips were repeatedly removed were as long as those of undecapitated controls.
- Taxon
- Avena sativa
Avena sativat0 - Treatment
- the tip of the coleoptile is repeatedly removede0
- Outcome
- Mesocotylse0
- Direction
- no_changeinferrede0
- Comparator
- control plants not so decapitatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“Mesocotyls of seedlinge from which the tip of the coleoptile is repeatedly removed are as long as those of control plants not so decapitated”
Claim · model-written summary
Mesocotyls of seedlings deseeded on day 3 and decapitated on day 4 were as long at 7 days old as those of undecapitated controls.
- Taxon
- Avena sativaAvena sativat0
- Treatment
- decapitation of the cleoptile tip on the 4th daye0
- Outcome
- Mesocotylse0
- Direction
- no_changeinferrede0
- Qualifier
- at 7 days olde0
- Comparator
- controls not so decapitatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“Mesocotyls of seedlings which are deseeded on the 3rd day of growth, followed by decapitation of the cleoptile tip on the 4th day, are, at 7 days old, as long as those of controls not so decapitated”
Claim · model-written summary
When deseeded plants are decapitated, regeneration of auxin production occurs at the tip of the coleoptile stump.
- Taxon
- Avena sativaAvena sativat0
- Organ / stage
- the tip of the coleoptile stumpe0
- Treatment
- decapitatede0
- Outcome
- regeneration of auxin productione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“When deseeded plants are decapitated, regeneration of auxin production occurs at the tip of the coleoptile stump”
Claim · model-written summary
A wound reaction is probably involved, in addition to any auxin changes, in the mesocotyl length reduction caused by decapitation.
- Taxon
- Avena sativaAvena sativat0
- Treatment
- decapitatione0
- Outcome
- reduction in the length of the mesocotyle0
- Qualifier
- a wound reaction is probably concerned in addition to any auxin changese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“Where a reduction in the length of the mesocotyl results from decapitation, a wound reaction is probably concerned in addition to any auxin changes”
Claim · model-written summary
Removal of the coleoptilar node causes a sharp decrease in the final mesocotyl length.
- Taxon
- Avena sativaAvena sativat0
- Treatment
- Removal of the coleoptilar nodee0
- Outcome
- final length of the mesocotyle0
- Direction
- decreasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“Removal of the coleoptilar node causes a sharp decrease in the final length of the mesocotyl”
Claim · model-written summary
Heating intact seedlings at 40° C. for 3 hours reduced mesocotyl length.
- Taxon
- Avena sativaAvena sativat0
- Treatment
- Heating intact seedlings at 40° C. for 3 hourse0
- Outcome
- the length of the mesocotyle0
- Direction
- reductione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“Heating intact seedlings at 40° C. for 3 hours causes a reduction in the length of the mesocotyl but not of the coleoptile”
Claim · model-written summary
Heating intact seedlings at 40° C. for 3 hours did not reduce coleoptile length.
- Taxon
- Avena sativaAvena sativat0
- Treatment
- Heating intact seedlings at 40° C. for 3 hourse0
- Outcome
- coleoptilee0
- Direction
- no_changeinferrede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“Heating intact seedlings at 40° C. for 3 hours causes a reduction in the length of the mesocotyl but not of the coleoptile”
Claim · model-written summary
Subsequent low-temperature treatment did not reverse the effect of heating and appeared to augment it.
- Taxon
- Avena sativaAvena sativat0
- Treatment
- subsequent treatment at low temperaturee0
- Outcome
- The effect of heatinge0
- Direction
- augmente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“The effect of heating is not reversed by subsequent treatment at low temperature, which instead appears to augment these effects”
Claim · model-written summary
Seedlings exposed to KCN, iodoacetate or anaerobic conditions while illuminated showed a reduction in mesocotyl length.
- Taxon
- Avena sativaAvena sativat0
- Treatment
- exposed to the action of KCN, iodoacetate, or anaerobic conditionse0
- Outcome
- length of the mesocotyle0
- Direction
- reductione0
- Qualifier
- illuminated while so exposede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“When seedlings are exposed to the action of KCN, iodoacetate, or anaerobic conditions, and illuminated while so exposed, perception of light takes place, resulting in a reduction in the length of the mesocotyl”
Claim · model-written summary
Light perception took place in seedlings germinated at normal temperatures and maintained at low temperature during illumination.
- Taxon
- Avena sativaAvena sativat0
- Organ / stage
- seedlings germinated at normal temperaturese0
- Treatment
- maintained at low temprature during illuminatione0
- Outcome
- Perception of lighte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“Perception of light takes place in seedlings germinated at normal temperatures, but maintained at low temprature during illumination and also in seedlings grown for 6 weeks at 2° C. without any previous growth at normal temperature”
Claim · model-written summary
Light perception took place in seedlings grown for 6 weeks at 2° C. without any previous growth at normal temperature.
- Taxon
- Avena sativaAvena sativat0
- Organ / stage
- seedlings grown for 6 weeks at 2° C.e0
- Treatment
- without any previous growth at normal temperaturee0
- Outcome
- Perception of lighte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“Perception of light takes place in seedlings germinated at normal temperatures, but maintained at low temprature during illumination and also in seedlings grown for 6 weeks at 2° C. without any previous growth at normal temperature”
Claim · model-written summary
Light perception took place in embryos excised from dry grain and grown on culture medium.
- Taxon
- Avena sativaAvena sativat0
- Organ / stage
- embryos excised from dry graine0
- Treatment
- grown on a culture mediume0
- Outcome
- Light perceptione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“Light perception takes place in embryos excised from dry grain and grown on a culture medium”
Claim · model-written summary
Free amino-acid content did not differ between dark-grown and illuminated seedlings.
- Taxon
- Avena sativaAvena sativat0
- Treatment
- illuminated seedlingse0
- Outcome
- free amino-acid contente0
- Direction
- No differencee0
- Comparator
- dark growne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“No difference in free amino-acid content is apparent between dark grown and illuminated seedlings”
Claim · model-written summary
Effects of illumination survived drying down and became apparent after germination of the grain in darkness.
- Taxon
- Avena sativaAvena sativat0
- Treatment
- illuminatione0
- Outcome
- effects of illuminatione0
- Qualifier
- survive a period of drying downe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“The effects of illumination survive a period of drying down and become apparent upon subsequent germination of the grain in darkness”
Claim · model-written summary
The drying process itself caused an additional reduction in mesocotyl length.
- Taxon
- Avena sativaAvena sativat0
- Treatment
- The drying process itselfe0
- Outcome
- mesocotyl lengthe0
- Direction
- reductione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“The drying process itself causes an additional reduction in mesocotyl length”
Claim · model-written summary
Auxin itself is not the primary reactant in the light perception process.
- Taxon
- Avena sativaAvena sativat0
- Compound
- auxine0
- Outcome
- perception processe0
- Qualifier
- not the primary reactante0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“It is concluded that auxin itself is not the primary reactant in the perception process”
Claim · model-written summary
Mesocotyl growth is probably controlled by the coleoptilar node and plumular growing point rather than by auxin diffusing down from the coleoptile tip.
- Taxon
- Avena sativaAvena sativat0
- Compound
- auxine0
- Outcome
- growth of the mesocotyle0
- Qualifier
- coleoptilar node and plumular growing pointe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesocotyl of Avena sativa”
e0“the growth of the mesocotyl is probably controlled by the coleoptilar node and plumular growing point, rather than by auxin diffusing downward from the tip of the coleoptile”