CASTLE E S
J Gen Physiol. 1962 Mar;45(4):743-56. doi: 10.1085/jgp.45.4.743.
The distribution of curvature and of bending speed along the cell's growing region are studied during steady state phototropic bending. At the start, elemental bending speed parallels the known axial distribution of growth rate. Hence regional phototropic sensitivity is initially determined by the local growth rate, and unilateral visible light acts proportionally at all levels of the growth zone. In the later course of bending, the bending speed distribution shifts downward instead of progressing upward in step with the cell's elongation. Furthermore, during phototropic inversion reversed bending begins high in the growth zone and progresses downward while normal bending continues below. These spatial and temporal changes in the distribution of differential growth are considered to be due to a fixed rate of supply of material used in growth that is transported from lower regions of the cell and asymmetrically distributed within the growth zone.
在稳态向光弯曲过程中，研究了曲率分布以及沿细胞生长区域的弯曲速度。一开始，基本弯曲速度与已知的生长速率轴向分布平行。因此，区域向光敏感性最初由局部生长速率决定，单侧可见光在生长区的所有水平上按比例起作用。在弯曲的后期，弯曲速度分布向下移动，而不是随着细胞伸长同步向上推进。此外，在向光反转过程中，反向弯曲在生长区较高位置开始并向下推进，而正常弯曲在下方继续。生长差异分布的这些空间和时间变化被认为是由于从细胞较低区域运输来的用于生长的物质供应速率固定，且在生长区内不对称分布所致。
