权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Dynamics of cytoskeleton myosin during the differentiation of xylem cells in trees

树木木质部细胞分化过程中细胞骨架肌球蛋白的动态

基本信息

批准号：
14560127
负责人：
FUNADA Ryo
金额：
$ 2.3万
依托单位：
Tokyo University of Agriculture and Technology (2003)Hokkaido University (2002)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

项目摘要

Cambial cells in tress differentiate into secondary xylem cells through a process of cell expansion, cell wall thickenings, lignification and cell death. During the differentiation, xylem, cells develop modifications of the cell wall such as pits and helical thickenings by the localized deposition of cell wall materials. Our previous results indicated that the localization of cell wall formation was related to the localized appearance and disappearance of components of the cytoskeleton, namely cortical microtubules and actin filaments, indicating that components of the cytoskeleton control the localized deposition of cell wall materials. However, we have only a few papers showing how the localization of components of the cytoskeleton is controlled. We analyzed here the role of myosins, so called motor-proteins, in the differentiation of xylem cells in tress because myosins utilize ATP to generate mechanical force along actin filaments. Firstly, we established the method of visualization of myosin in xylem cells. Myosins were immuno-stained with a monoclonal antibody against myosins and then FITC-conjugated secondary antibody. They were observed by confocal laser scanning microscopy. Fluorescence derived from myosins was observed in differentiating xylem cells. Myosins were aggregated at the sites of apertures of intertracheal bordered pits. As xylem cells differentiated, the aggregation of myosins decreased in diameter. The reduction in diameter of myosins was associated with the development of bordered pits. Such a localization of myosins was a similar to that of actin filaments in differentiating xylem cells. Our results indicate that an acto-myosin contractile system, being a similar manner to the contraction of mammalian muscle, might be present at the site of pit formation. We conclude that myosins play an important role in the formation of modified structure, therefore controlling the morphogenesis of secondary xylem cells.

树木形成层细胞经过细胞膨胀、细胞壁增厚、木质化和细胞死亡的过程，分化为次生木质部细胞。在木质部细胞的分化过程中，细胞壁发生了变化，如细胞壁物质的局部沉积引起的纹孔和螺旋状加厚。我们以前的研究结果表明，细胞壁形成的本地化有关的局部出现和消失的组件的细胞骨架，即皮层微管和肌动蛋白丝，表明组件的细胞骨架控制的局部沉积的细胞壁材料。然而，我们只有几篇论文显示细胞骨架的成分的定位是如何控制的。我们分析了肌球蛋白（也称马达蛋白）在树木木质部细胞分化中的作用，因为肌球蛋白利用ATP沿沿着肌动蛋白丝产生机械力。首先，我们建立了木质部细胞肌球蛋白的可视化方法。肌球蛋白用针对肌球蛋白的单克隆抗体免疫染色，然后用FITC缀合的二抗免疫染色。共聚焦激光扫描显微镜观察细胞形态。在分化的木质部细胞中观察到来自肌球蛋白的荧光。肌球蛋白聚集在气管间窝的开口处。随着木质部细胞的分化，肌球蛋白聚集体的直径减小。肌球蛋白直径的减少与有界小凹的形成有关。肌球蛋白的这种定位与木质部细胞分化过程中肌动蛋白丝的定位相似。我们的研究结果表明，肌动蛋白-肌球蛋白收缩系统，是一个类似的方式，哺乳动物肌肉的收缩，可能存在于网站的坑形成。我们的结论是，肌球蛋白在修饰结构的形成中起着重要作用，因此控制着次生木质部细胞的形态发生。