Cryopreparation and Subcellular Localization of Diffusible Substances in Plant Tissues

在电子显微镜水平上了解亚细胞可扩散物质的定位对于理解细胞生理学是非常重要的。到目前为止，获取这些信息所需的技术方法主要应用于动物细胞系统。缺乏对植物组织的这种研究主要是由于标本制备的困难，这些标本与植物细胞和组织中存在的细胞壁、细胞间隙和大液泡等特征有关。对于微量分析，重要的是样品制备过程不能以任何方式改变感兴趣的亚细胞成分(加、减、移、掩蔽)。因此，开发应用于植物系统的必要技术需要大量的时间和精力投入。拟议的研究将采用现有的动物细胞方法，并在必要时开发其他技术，用于冷冻固定、超薄切片和分析冷冻水合植物标本。如果成功，这些技术的发展将使植物细胞中具有重要生理意义的元素的分析和定位成为可能。这些基本信息将对理解植物细胞生物学非常重要。

Knowledge of the localization of subcellular, diffusible substances at the electron microscope level is very important for understanding of cellular physiology. The technical approaches required to obtain this information, have thus far been applied chiefly to animal cell systems. The lack of such studies of plant tissues is due primarily to difficulties in specimen preparation related to the presence in plant cells and tissues of features such as cell walls, intercellular air spaces, and large vacuoles. For microanalysis it is critical that subcellular elements of interest not be altered in any way (addition, subtraction, movement, masking) by the specimen preparation procedures. Thus, a substantial investment of time and effort is required to develop the necessary technology for application to plant systems. The proposed research will adapt existing animal cell methods and, as necessary, develop additional techniques for the cryofixation, ultrathin sectioning, and analysis of frozen- hydrated plant specimens. If successful, the development of these techniques will permit analysis of elemental composition and localization of elements of physiological importance in plant cells. This fundamental information will be of great importance to the understanding of plant cell biology.