摘要
压力探针技术是一种用来测定微系统中压力大小和变化的新技术。其最初被设计用于直接测定巨型藻类的细胞膨压。随着操作装置的进一步微型化和精密化,后来被应用于测定普通高等植物细胞膨压及其它水分关系参数。该技术的发展建立在一系列相应的流体物理学理论基础上。通过这些物理学公式的计算,该技术能测定跨细胞膜或器官的水分运输速度以及它们的水力学导度;测定溶液中水分和溶质的相对运输速度以及它们之间的相互影响;还可以测定细胞壁的刚性等。目前压力探针技术已成为植物生理学和生态学领域研究中的多用途技术。它可以在细胞水平上原位测定水分及溶质跨膜运输及分布情况,这对于阐明水通道功能具有极其重要的意义。此外,木质部压力探针技术是目前唯一可以直接测定导管或管胞中负压的工具。该技术还可以用于单细胞汁液的样品采集,结合微电极技术测定导管或其它细胞中的pH值、离子浓度以及细胞膜电位。本文重点介绍该技术使用的基本原理和相应的理论基础,并详细地描述了操作过程中的技术和技巧。
Pressure probe techniques are basically employed to measure the size and changes in pressure in micro-systems. The pressure probe originally was designed to detect giant algal-cell turgor, then was adapted to measure turgor and other waterrelation parameters of higher plants after being improved by reducing magnitude and increasing accuracy. The techniques are based on theories of the thermodynamics of liquid. Through calculation with use of equations from liquid physics, the techniques can be used to measure water flow and hydraulic conductivity through individual cells and tissues of plants, determine the relative flow of water and solutes over membranes and organs and their interactions, and determine the rigidity of the cell wall. The techniques now have become a diverse tool for research into plant physiology and eco-physiology. This pressure-probe technique can measure in situ permeability of cell membranes to water and solutes at the resolution of single cells and hence is a useful tool to study function and regulation of water channels （aquaporins） of intact plant cells. The recently developed xylem-pressure probe technique is the only means to directly measure negative pressure in xylem conduits. Additionally, the technique is used to extract sap from an individual cell and detect pH and ion concentrations in xylem conduits. In this paper, we introduce the basic principles and the theoretical background underlying the pressure probe and detail the operational skills.
出处
《植物学通报》
CSCD
北大核心
2008年第4期497-506,共10页
Chinese Bulletin of Botany
基金
国家自然科学基金(No.30770183)
十一五国家科技支撑计划(No.2006BAD03A05
No.2006BAD03A11和No.2006BAD19B0201)
关键词
细胞水分关系
压力探针
反射系数
溶质运输.细胞膨压
cell water relations, pressure probe, reflection coefficient, solute transport, turgor
