Thresholds for georesponse to acceleration in gravity-compensated Avena seedlings.
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The magnitude of acceleration required to induce growth responses in Avena seedlings grown in the absence of tropic response to earth gravity has been investigated and a clinostat was developed that imposes accelerations from about 10(-9) g to 3 g upon the seedling; simultaneously, it nullifies, or compensates for, response to the directional component of the gravitational-force vector by rotating the seedlings on a horizontal axis.Abstract:
The magnitude of acceleration required to induce growth responses in Avena seedlings grown in the absence of tropic response to earth gravity has been investigated. For this purpose, a clinostat was developed that imposes accelerations from about 10−9 g to 3 g upon the seedling; simultaneously, it nullifies, or compensates for, response to the directional component of the gravitational-force vector by rotating the seedling on a horizontal axis. When accelerations less than 10−3 g are applied in either the acropetal or the basipetal direction, the growth in length and weight of the various organs is not materially different from that of compensated seedlings to which no longitudinal force is applied. At accelerations between 10−3 and 10−2 g, differences in growth become highly significant. When the centrifugal forces are transverse to the seedling during compensation, the threshold acceleration range for geoperception, as manifest by shoot reorientation, is again between 10−3 and 10−2 g. Geotropic reorientation of the root becomes apparent after exposures between 10−4 and 10−3 g.read more
Citations
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Evaluation of the three-dimensional clinostat as a simulator of weightlessness
TL;DR: The parameters analyzed up to now demonstrate that the 3-D clinostat is a valuable device for simulating weightlessness, and some of the vegetative growth phases of plants dependent on the gravity vector, such as morphogenesis, are shown to be influenced by rotation on the3-D Clinostat.
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Perception of Gravity by Plants
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Changes in Plant Growth Processes under Microgravity Conditions Simulated by a Three - Dimensional Clinostat
TL;DR: A three-dimensional (3-D) clinostat was developed to simulate a microgravity environment and the changes in plant growth processes under this condition showed that autotropism may have an important role in regulation of life cycle of higher plants under a micro gravity environment.
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Biology of Plant Cells in Microgravity and under Clinostating
TL;DR: Ideas on the acceleration of differentiation and aging of cells in microgravity and clinostating and the organism's adaptive possibilities for carrying out its own functions are discussed.
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The physical basis of gravity stimulus nullification by clinostat rotation.
R. R. Dedolph,M. H. Dipert +1 more
TL;DR: It is shown that most low gravity biological responses can be studied using clinostats with only occasional satellite free fall experiments for verification and it is inferred that most of these responds can be effectively and economically studied by computer simulation.
References
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Influence of Gravity on Rate of Elongation and on Geotropic and Autotropic Reactions in Roots
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