Source:http://linkedlifedata.com/resource/pubmed/id/16659909
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
4
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| pubmed:dateCreated |
2010-6-29
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| pubmed:abstractText |
A centrifuge was used to provide sustained acceleration in order to study the hypocotyl nutation of 6-day-old Helianthus annuus L. over a range of g-forces, up to 20 times normal g. At the upper end of this g-range, nutation was impeded and at times was erratic evidently because the weight of the cotyledons exceeded the supportive abilities of the hypocotyls.Over the range 1 to 9 g, the period of nutation was independent of the resultant force vector. Over the same g-range, the amplitude of nutation was nearly independent of the chronic g-force.If nutation in sunflower seedlings is an oscillation caused by a succession of geotropic responses which continue to overshoot the equilibrium position (plumb line), we might expect its amplitude to be more sensitive to changes in magnitude of the sustained g-force. In order to preserve the geotropic model of nutation-viz. that it is a sustained oscillation driven by geotropic reactions, it is necessary to assume that geotropic response must increase with increasing g most rapidly in the region of the g-parameter below the terrestrial value of 1 g.
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| pubmed:commentsCorrections | |
| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:status |
PubMed-not-MEDLINE
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| pubmed:month |
Apr
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| pubmed:issn |
0032-0889
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:volume |
59
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
636-40
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| pubmed:dateRevised |
2010-9-14
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| pubmed:year |
1977
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| pubmed:articleTitle |
Effects of increased gravity force on nutations of sunflower hypocotyls.
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| pubmed:affiliation |
Plant Centrifuge Laboratory, University City Science Center and Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19174.
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| pubmed:publicationType |
Journal Article
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