PHOTOTROPISM AND THE LIGHT-SENSITIVE SYSTEM OF PHYCOMYCES
نویسندگان
چکیده
منابع مشابه
Phototropism and the Light-sensitive System of Phycomyces
1. The reaction time of the direct growth response of the sporangiophore of Phycomyces to light consists of a series of at least three major identifiable components: (a) an exposure period during which photochemical change occurs; (b) a latent period involving products directly consequent upon the photochemical action; and (c) an action-time occupying a further interval before the growth accele...
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Light and dark adaptation of the phototropism of Phycomyces sporangiophores were analyzed in the intensity range of 10(-7)-6 W X m-2. The experiments were designed to test the validity of the Delbrück-Reichardt model of adaptation (Delbrück, M., and W. Reichardt, 1956, Cellular Mechanisms in Differentiation and Growth, 3-44), and the kinetics were measured by the phototropic delay method. We fo...
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Phototropic bending can be initiated without the transient changes in growth speed that characterize a light-growth response. The conditions required are a change from a symmetric to an asymmetric illumination pattern while the cell receives a constant radiant flux. Phototropism is thus basically a steady state process. It cannot be founded on differential light-growth responses as in Blaauw's ...
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Normally, the dioptrics in air of the cylindrical sporangiophore of Phycomyces blakesleeanus confer on the distal side a focusing advantage of about 30 per cent for unilateral stimuli of parallel light. This advantage can be nullified or reversed to produce negative curvatures by means of diverging light stimuli. A thin cylindrical glass lens was positioned 0.15 mm from the light-adapted growin...
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The steady-state phototropic bending of Phycomyces sporangiophores was studied using apparatus designed to keep the growing zone vertical and the angle of illumination constant over long periods of time. The bending speed is quite constant if the intensity and angle of illumination are fixed. A phototropic inversion occurs in response to a sudden change in intensity, either an increase or a dec...
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ژورنال
عنوان ژورنال: Journal of General Physiology
سال: 1930
ISSN: 1540-7748,0022-1295
DOI: 10.1085/jgp.13.4.421