Changes in plant growth processes under microgravity conditions simulated by a three-dimensional clinostat
Changes in plant growth processes under microgravity conditions simulated by a three-dimensional clinostat
复制标题
三维回转器模拟微重力条件下植物生长过程的变化
DOI：
--
复制
发表时间：
1992
期刊：
影响因子：
--
通讯作者：
M. Yamashita
中科院分区：
文献类型：
--
作者：
T. Hoson;S. Kamisaka;Y. Masuda;M. Yamashita
我们开发了一个三维回转器来模拟微重力环境，并研究了在这种条件下植物生长过程的变化。水芹（独行菜），玉米（玉米），水稻（水稻），豌豆（豌豆），或赤豆（豇豆）的发芽率不受回转器。回转器的旋转并不影响其根或芽的生长速率，除了在Azuki根和上胚轴的生长略有促进。相反，植物器官的生长方向在三维回转器上明显改变。在地球表面，根向下生长，而芽则平行于重力矢量向上生长。在三维回转器上，水芹根系在不断改变方向后，沿根原基顶端方向沿着伸长。水稻根也平行于根原基顶端方向生长。另一方面，玉米、豌豆和红豆的根以随机方式生长。即使在3-D回转器上，芽的生长方向也更受控制。从胚的正面看，新梢主要沿着原基顶端方向生长。从侧面观察，水稻的胚芽鞘向颖果方向弯曲，而玉米的胚芽鞘、豌豆和红豆的上胚轴向远轴方向弯曲。枝条的弯曲度随生长而增大。这种自向性可能在微重力环境下高等植物生活史的调节中起重要作用。
We developed a three-dimensional (3-D) clinostat to simulate a microgravity environment and studied the changes in plant growth processes under this condition. The rate of germination of cress (Lepidium sativum), maize (Zea mays), rice (Oryza sativa), pea (Pisum sativum), or azuki bean (Vigna angularis) was not affected on the clinostat. The clinostat rotation did not influence the growth rate of their roots or shoots, except for a slight promotion of growth in azuki roots and epicotyls. On the contrary, the direction of growth of plant organs clearly changed on the 3-D clinostat. On the surface of the earth, roots grow downward while shoots upward in parallel to the gravity vector. On the 3-D clinostat, roots of cress elongated along the direction of the tip of root primordia after having changed the direction continuously. Rice roots also grew parallel to the direction of the tip of root primordia. On the other hand, roots of maize, pea, and azuki bean grew in a random fashion. The direction of growth of shoots was more controlled even on the 3-D clinostat. In a front view of embryos, shoots grew mostly along the direction of the tip of primordia. In a side view, rice coleoptiles showed an adaxial (toward the caryopsis) while coleoptiles of maize and epicotyls of pea and azuki bean an abaxial curvature. The curvature of shoots became larger with their growth. Such an autotropism may have an important role in regulation of life cycle of higher plants under a microgravity environment.