THRESHOLDS FOR GEORESPONSE TO ACCELERATION IN GRAVITY-COMPENSATED AVENA SEEDLINGS
THRESHOLDS FOR GEORESPONSE TO ACCELERATION IN GRAVITY-COMPENSATED AVENA SEEDLINGS
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DOI：
10.1104/pp.43.3.338
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发表时间：
1968-01-01
期刊：
影响因子：
7.4
通讯作者：
GORDON, SA
中科院分区：
文献类型：
--
作者：
SHENMILLER, J;HINCHMAN, R;GORDON, SA
本文研究了在对地球重力无回归反应的情况下，引起豌豆幼苗生长反应所需的加速度的大小。为此，人们开发了回转器，它对秧苗施加约10 - 9 g至3 g的加速度;同时，它通过使秧苗在水平轴上旋转来抵消或补偿对重力矢量的方向分量的响应。当在向顶或向基的方向上施加小于10 - 3g的加速度时，各种器官的长度和重量的生长与没有施加纵向力的补偿幼苗的生长没有实质性的不同。在10 - 3和10 - 2g之间的加速度下，生长差异变得非常显著。当离心力在补偿过程中横向于秧苗时，地感知的阈值加速度范围（如枝条重定向所示）也在10 - 3和10 - 2g之间。在10− 4和10− 3 g之间的暴露后，根部的向地重定向变得明显。
The magnitude of acceleration required to induce growth responses inAvenaseedlings 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 10−9g 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 10−3g 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 10−3and 10−2g, 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 10−3and 10−2g. Geotropic reorientation of the root becomes apparent after exposures between 10−4and 10−3g.