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Phototropism and Local Adaptation in Phycomyces Sporangiophores
Phototropic responses to unilateral ultraviolet stimuli were studied to determine whether the response of one side of the cell is affected by the previous exposure of the opposite side to ultraviolet. It has been found that the direction of bending is not parallel to the stimulus direction, but is a...
Autores principales: | , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
1973
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2226114/ https://www.ncbi.nlm.nih.gov/pubmed/4722566 |
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author | Dennison, David S. Bozof, Richard P. |
author_facet | Dennison, David S. Bozof, Richard P. |
author_sort | Dennison, David S. |
collection | PubMed |
description | Phototropic responses to unilateral ultraviolet stimuli were studied to determine whether the response of one side of the cell is affected by the previous exposure of the opposite side to ultraviolet. It has been found that the direction of bending is not parallel to the stimulus direction, but is along a straight line rotated 17° clockwise from the stimulus direction. This deviation indicates that the photoreceptors may be in a state of continual clockwise rotation. If before the stimulus the cell is exposed briefly to ultraviolet and rotated through 90°, the response is not along the 17° line, but is deviated a greater or lesser amount, depending on whether the 90° rotation is clockwise or counterclockwise. This difference is evidence that the first ultraviolet exposure leaves a persistent patch of light-adapted receptors and the shaded part of the cell remains dark adapted. The phototropic stimulus straddles the edge between light- and dark-adapted regions, and the differing responses of the two regions affects the direction of phototropic bending. A phototropic mechanism is proposed which combines the features of local adaptation and photoreceptor rotation. |
format | Text |
id | pubmed-2226114 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1973 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-22261142008-04-23 Phototropism and Local Adaptation in Phycomyces Sporangiophores Dennison, David S. Bozof, Richard P. J Gen Physiol Article Phototropic responses to unilateral ultraviolet stimuli were studied to determine whether the response of one side of the cell is affected by the previous exposure of the opposite side to ultraviolet. It has been found that the direction of bending is not parallel to the stimulus direction, but is along a straight line rotated 17° clockwise from the stimulus direction. This deviation indicates that the photoreceptors may be in a state of continual clockwise rotation. If before the stimulus the cell is exposed briefly to ultraviolet and rotated through 90°, the response is not along the 17° line, but is deviated a greater or lesser amount, depending on whether the 90° rotation is clockwise or counterclockwise. This difference is evidence that the first ultraviolet exposure leaves a persistent patch of light-adapted receptors and the shaded part of the cell remains dark adapted. The phototropic stimulus straddles the edge between light- and dark-adapted regions, and the differing responses of the two regions affects the direction of phototropic bending. A phototropic mechanism is proposed which combines the features of local adaptation and photoreceptor rotation. The Rockefeller University Press 1973-08-01 /pmc/articles/PMC2226114/ /pubmed/4722566 Text en Copyright © 1973 by The Rockefeller University Press This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Article Dennison, David S. Bozof, Richard P. Phototropism and Local Adaptation in Phycomyces Sporangiophores |
title | Phototropism and Local Adaptation in Phycomyces Sporangiophores |
title_full | Phototropism and Local Adaptation in Phycomyces Sporangiophores |
title_fullStr | Phototropism and Local Adaptation in Phycomyces Sporangiophores |
title_full_unstemmed | Phototropism and Local Adaptation in Phycomyces Sporangiophores |
title_short | Phototropism and Local Adaptation in Phycomyces Sporangiophores |
title_sort | phototropism and local adaptation in phycomyces sporangiophores |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2226114/ https://www.ncbi.nlm.nih.gov/pubmed/4722566 |
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