The Control of the Differentiation of Vascular Networks
The Control of the Differentiation of Vascular Networks
复制标题
血管网络分化的控制
DOI：
10.1093/oxfordjournals.aob.a084930
复制
发表时间：
1975
期刊：
影响因子：
4.2
通讯作者：
T. Sachs
中科院分区：
文献类型：
--
作者：
T. Sachs
极性控制的维管分化的刺激从地上部移动到根已被证明了很多次，并占维管束的模式的一些特点。这里要解决的问题是，这种极性机制是否控制着叶片中常见的维管网络的形成。网络通常（尽管并非总是如此）包括不将芽连接到根的链，因此不能被认为是极性的。菜豆茎中有一条小的横向维管束，它包括相邻的导管，这些导管具有相反的茎根方向。一项发育研究表明，具有相反极性的血管不会同时成熟，并表明控制血管形成的极性刺激的流动方向存在重复变化。Pisum的实验表明，当生长素来源的位置和生长素流动的方向反复改变时，生长素可以诱导木质部形成非极性链。得出的结论是，在血管分化的第一阶段，分化诱导刺激的运动轴是确定的，而不是方向。当整个器官的发育速度和刺激产生的速度不同步时，这种运动轴的早期确定导致血管网络的分化。
A polar control of vascular differentiation by stimuli moving from the shoot to the root has been demonstrated many times and accounts for some traits of the pattern of vascular strands. The problem dealt with here is whether this polar mechanism controls the formation of the vascular networks which are common in leaves. Networks generally, though not invariably, include strands which do not connect the shoot to the root, and therefore cannot be considered as polar. A small transverse vascular strand inPhaseolusstems includes neighbouring vessels which have opposite shoot to root directions. A developmental study indicated that vessels with opposite polarities do not mature at the same time, and suggested that there are repeated changes in the direction of the flow of the polar stimuli which control vessel formation. Experiments withPisumshow that auxin can induce the formation of a non-polar strand of xylem when the location of the source of auxin, and the resulting direction of auxin flow, are changed repeatedly. It is concluded that in the first stages of vascular differentiation there is a determination of the axis, but not of the direction, of the movement of differentiation-inducing stimuli. When the rate of development and of the production of stimuli is not synchronous throughout the organ, this early determination of an axis of movement leads to the differentiation of vascular networks.