Polarized cytokinesis in vacuolate cells of Arabidopsis
Polarized cytokinesis in vacuolate cells of Arabidopsis
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DOI：
10.1073/pnas.052712299
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发表时间：
2002-03-05
影响因子：
11.1
通讯作者：
Ehrhardt, DW
中科院分区：
文献类型：
--
作者：
Cutler, SR;Ehrhardt, DW
教科书上通常描述的植物细胞胞质分裂的观点是一个对称过程，成膜体在细胞中心开始，向外生长到亲本细胞膜。与这张图片相反，我们观察到拟南芥茎细胞的细胞板发育沿着分裂平面高度极化。三维活细胞成像显示有丝分裂纺锤体和成膜体横向移位，并且生长的细胞板在胞质分裂的早期锚定在细胞的一侧。成膜体在细胞中的生长在其尾迹中形成了一个新的分区，给人一种窗帘被拉过细胞的视觉效果。在整个过程中，成膜体的前进前端与亲本壁密切接触，这表明成膜体和质膜之间的短程相互作用可能在引导细胞板的整个发育过程中发挥重要作用。在多种液泡芽细胞和一些小根细胞中观察到极化胞质分裂，这意味着它不仅仅是细胞大小的函数。这种胞质分裂模式可能为大细胞中细胞板的形成提供机械上稳健的机制，并为在药物处理或细胞分裂突变体中观察到的细胞壁残端的出现提供简单的解释。
The view of plant-cell cytokinesis commonly depicted in textbooks is of a symmetrical process, with the phragmoplast initiating in the center of the cell and growing outward to the parental cell membrane. In contrast to this picture, we observe that cell-plate development in Arabidopsis shoot cells is highly polarized along the plane of division. Three-dimensional live-cell imaging reveals that the mitotic spindle and phragmoplast are laterally displaced, and that the growing cell plate anchors on one side of the cell at an early stage of cytokinesis. Growth of phragmoplast across the cell creates a new partition in its wake, giving the visual effect of a curtain being pulled across the cell. Throughout this process, the advancing front of the phragmoplast is in intimate contact with the parental wall, suggesting that short-range interactions between the phragmoplast and plasma membrane may play important roles in guiding the cell plate throughout much of its development. Polarized cytokinesis was observed in a wide variety of vacuolate shoot cells and in some small root cells, implying that it is not solely a function of cell size. This mode of cytokinesis may provide a mechanically robust mechanism for cell-plate formation in large cells and suggests a simple explanation for the occurrence of cell wall stubs observed upon drug treatment or in cytokinetic mutants.