Volkmann D, Sievers A
Botanisches Institut der Universität Bonn, Venusbergweg 22, D-5300, Bonn, Federal Republic of Germany.
Planta. 1975 Jan;127(1):11-9. doi: 10.1007/BF00388858.
Primary roots of Lepidium sativum (L.s.) grew upwards in glass capillaries in order to prevent mechanically the geotropic curvature. The central cap cells (statocytes) were investigated with regard to the polar arrangement of their organelles. After 20 minutes of inversion, which correspond to the latent period of L.s., only the amyloplasts have left their original position and sedimented at the proximal cell pole. All the other organelles, particularly the ER-complex located near the distal periclinal cell wall, remain stationary. After 2 hours of forced inversion, which correspond to the reaction time of L.s., a second ER-complex is visible in the proximal cell pole in addition to the distal ER-complex. The new proximal ER-complex originates underneath the sedimented amyloplasts. The number of stacked cisternae in the proximal ER-complex is still smaller than in the distal one. After 18 hours of forced inversion the number of proximal cisternae has increased and is almost equal to the number of cisternae in the distal ER-complex.The proximal ER-complex seems to be formed by the nuclear envelope. The new synthesis is induced by a long-time inversion. This supports the postulation that the contact between amyloplasts and an ER-complex is a condition of geoperception.
为了机械性地防止向地性弯曲，独行菜（L.s.）的初生根在玻璃毛细管中向上生长。对中央帽细胞（平衡石细胞）细胞器的极性排列进行了研究。在倒置20分钟后，这与独行菜的潜伏期相对应，只有淀粉体离开了它们原来的位置并沉积在细胞近端极。所有其他细胞器，特别是位于细胞远端周缘细胞壁附近的内质网复合体，保持静止。在强制倒置2小时后，这与独行菜的反应时间相对应，除了远端内质网复合体外，在细胞近端极还可见第二个内质网复合体。新的近端内质网复合体起源于沉积的淀粉体下方。近端内质网复合体中堆叠的潴泡数量仍然比远端的少。在强制倒置18小时后，近端潴泡的数量增加，几乎与远端内质网复合体中的潴泡数量相等。近端内质网复合体似乎由核膜形成。长时间倒置诱导了新的合成。这支持了淀粉体与内质网复合体之间的接触是地球感知条件的假设。
