Department of Biological Sciences, Texas Tech University, P.O. Box 4149, 79409, Lubbock, TX, USA.
Planta. 1990 Mar;180(4):502-9. doi: 10.1007/BF02411447.
Tracheary-element (TE) differentiation in suspension cultures ofZinnia elegans L. mesophyll cells was inhibited by blocking calcium uptake in three ways: 1) reducing the [Ca(2+)] of the culture medium, 2) blocking calcium channels with the non-permeant cation La(3+), and 3) blocking calcium channels with permeant dihydropyridine calcium-channel blockers. Calcium-channel blockers were effective when added at any time between 0 and 48 h after culture initiation; after 48h, calcium sequestration and secondary cell-wall deposition began. In contrast, calmodulin antagonists inhibited TE differentiation when added at the beginning of culture, but not when added after 24h. These results indicate that TE differentiation involves at least two calcium-regulated events: one calmodulin-dependent and occurring shortly after exposure to inductive conditions, and the other calmodulin-independent and occurring just prior to secondary cell-wall deposition.
悬浮培养的百日草叶片细胞中木质部细胞（TE）的分化可以通过以下三种方式抑制钙的摄取：1）降低培养基中的[Ca(2+)]，2）用非通透的阳离子 La(3+)阻断钙通道，3）用通透的二氢吡啶钙通道阻断剂阻断钙通道。钙通道阻断剂在培养起始后 0 至 48 小时的任何时间添加都是有效的；48 小时后，钙螯合和次生细胞壁沉积开始。相比之下，钙调蛋白拮抗剂在培养开始时添加可以抑制 TE 分化，但在 24 小时后添加则没有效果。这些结果表明，TE 分化至少涉及两个钙调节事件：一个是钙调蛋白依赖性的，发生在接触诱导条件后不久，另一个是钙调蛋白非依赖性的，发生在次生细胞壁沉积之前。
