Quantitative X-ray Elemental Imaging in Plant Materials at the Subcellular Level with a Transmission Electron Microscope: Applications and Limitations.
Quantitative X-ray Elemental Imaging in Plant Materials at the Subcellular Level with a Transmission Electron Microscope: Applications and Limitations.
复制标题
使用透射电子显微镜在亚细胞水平上对植物材料进行定量 X 射线元素成像：应用和局限性
DOI：
10.3390/ma7043160
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发表时间：
2014-04-21
期刊：
影响因子：
--
通讯作者：
Polle A
中科院分区：
文献类型：
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作者：
Chen S;Diekmann H;Janz D;Polle A
能量色散X射线显微分析（EDX）是一种用于确定各种材料中元素分布的技术。在这里，我们报告了一个协议，高空间分辨率的X射线元素成像和定量在植物组织中的亚细胞水平与扫描透射电子显微镜（STEM）。校准标准品通过生产加载有增加的KCl或NaCl浓度的琼脂块来建立。TEM-EDX图像显示盐均匀地分布在琼脂基质中，但在高浓度下倾向于聚集。在整个测试浓度范围内，来自元素图像的K+、Cl −和Na+的平均强度与琼脂中这些元素的浓度呈线性相关（R> 0.916）。我们将这种方法应用于植物根组织。以50 nm × 50 nm至100 nm × 100 nm的实际分辨率获取X射线图像。我们发现，细胞壁表现出较高的元素浓度比液泡。暴露于盐胁迫的植物表现出Na+和Cl −在运输组织中的急剧积累，并达到与外部溶液（300 mM）中所应用的水平相似的水平。TEM-EDX绘图的优点是实现了对特定区域中的元素分布进行成像的高空间分辨率，同时对多个目标元素进行定量分析。
Energy-dispersive X-ray microanalysis (EDX) is a technique for determining the distribution of elements in various materials. Here, we report a protocol for high-spatial-resolution X-ray elemental imaging and quantification in plant tissues at subcellular levels with a scanning transmission electron microscope (STEM). Calibration standards were established by producing agar blocks loaded with increasing KCl or NaCl concentrations. TEM-EDX images showed that the salts were evenly distributed in the agar matrix, but tended to aggregate at high concentrations. The mean intensities of K+, Cl−, and Na+ derived from elemental images were linearly correlated to the concentrations of these elements in the agar, over the entire concentration range tested (R > 0.916). We applied this method to plant root tissues. X-ray images were acquired at an actual resolution of 50 nm × 50 nm to 100 nm × 100 nm. We found that cell walls exhibited higher elemental concentrations than vacuoles. Plants exposed to salt stress showed dramatic accumulation of Na+ and Cl− in the transport tissues, and reached levels similar to those applied in the external solution (300 mM). The advantage of TEM-EDX mapping was the high-spatial-resolution achieved for imaging elemental distributions in a particular area with simultaneous quantitative analyses of multiple target elements.