Plasmodesmata
Plasmodesmata
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DOI：
10.1016/j.cub.2008.01.046
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发表时间：
2008-04
期刊：
影响因子：
9.2
通讯作者：
P. Zambryski
中科院分区：
文献类型：
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作者：
P. Zambryski
plasmodesma这个词来源于拉丁语plasmo，意思是流体，希腊语desma，意思是债券。这个词的起源正好揭示了胞间连丝的功能。植物细胞被包裹在形成植物骨架的细胞壁中，使三维生长成为可能并保持稳定。试想一下，如果没有植物细胞壁，芹菜会是什么？然而，丰富的细胞外细胞壁物质的存在意味着植物细胞物理上不接触。为了实现细胞间的通讯，植物进化出了细胞质桥，称为胞间连丝，它跨越细胞壁，连接相邻细胞之间的流体细胞质。一个普通的胞间连丝有两个主要组成部分：膜和间隙（图1）。膜形成胞间连丝通道的边界，通过该通道可以发生运输。相邻细胞之间的质膜限定了胞间连丝的外部界限。胞间连丝的轴向中心是连丝小管，它来源于并置的内质网（ER），内质网在细胞间是连续的。桥小管和质膜之间的区域是细胞质套管，是分子通过的主要通道。胞质袖包含的成分（图1，圆圈），桥接质膜和桥小管之间的孔，以调节和促进胞间连丝的结构和运输。例如，沿胞间连丝长度方向存在的肌动蛋白和肌球蛋白沿着提供了调节胞间连丝孔径的可能的收缩机制。
The word plasmodesma derives from the Latin ‘plasmo’meaning fluid and the Greek ‘desma’meaning bond. The origin of the word exactly exposes the function of plasmodesmata. Plant cells are encased in cell walls that form the plant skeleton, enabling and stabilizing three-dimensional growth. Just think what would celery be without plant cells walls? However, the presence of abundant extracellular cell wall material means that plant cells physically do not touch. To enable intercellular communication, plants have evolved cytoplasmic bridges, called plasmodesmata, which span cell walls, linking the fluid cytoplasm between adjacent cells. A generic plasmodesma has two major components: membranes and spaces (Figure 1). Membranes form the boundaries of the plasmodesmata channel through which transport may occur. The plasma membrane between adjacent cells defines the outer limit of plasmodesmata. The axial center of the plasmodesmata, the desmotubule, is derived from juxtaposed endoplasmic reticulum (ER) which is continuous between cells. The region between the desmotubule and the plasma membrane is the cytoplasmic sleeve, the major conduit for molecular passage. The cytoplasmic sleeve contains components (Figure 1, circles) that bridge the aperture between the plasma membrane and desmotubule to regulate and facilitate plasmodesmata structure and transport. For example, the presence of actin and myosin along the length of plasmodesmata provides for a possible contractile mechanism to regulate plasmodesmata aperture.