Cadmium in bean roots
Cadmium in bean roots
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DOI：
10.1111/j.1469-8137.1992.tb05657.x
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发表时间：
1992-02
期刊：
影响因子：
9.4
通讯作者：
M. D. Vázquez;C. Poschenrieder;Y. Barceld
中科院分区：
文献类型：
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作者：
M. D. Vázquez;C. Poschenrieder;Y. Barceld
研究了低浓度（0.5 μM）对菜豆（Phaseolus vulgaris L.）根进行了分析，在24小时的间隔为144小时后开始的镉供应。暴露于镉144小时后，镉的细胞和亚细胞的位置进行了测定两个组织化学的银硫化物法和能量色散X射线显微分析。暴露48 h后，根伸长显著下降，这是由于镉抑制了根细胞分裂所致。在皮下组织中观察到类似于传递细胞的细胞壁向内生长的形成，表明Cd诱导的离子转运改变。我们的结果上的位置镉的银硫化物法，在光学显微镜水平上，表明，镉主要积累在外皮层细胞，很少在内皮。在亚细胞水平上，指示镉存在的银沉积物主要存在于液泡和细胞核中，在较小程度上存在于细胞质和质体中，但不在细胞壁中。X-射线微区分析证实存在镉的液泡和细胞核，但未能检测到镉在任何其他细胞室。讨论了组织化学和X射线微量分析方法在植物中微量镉定位中的优缺点。
The influence of a low concentration (0.5 μM) on the growth and ultrastructure of bean (Phaseolus vulgaris L.) roots was analysed at 24 h intervals for 144 h following the start of Cd supply. After 144 h exposure to Cd the cellular and subcellular location of Cd was determined both histochemically by the silver sulphide method and by energy dispersive X-ray microanalysis. A significant decrease in root elongation was observed after 48 h exposure, due to the inhibition of root cell division by Cd. Formation of cell wall ingrowths similar to those of transfer cells were observed in the hypodermis, suggesting a Cd-induced alteration of ion transport. Our results on the location of Cd by the silver sulphide method, at the light microscope level, suggest that Cd principally accumulates in the outer cortex cells, with very little in the endodermis. At the subcellular level, silver deposits indicating the presence of Cd were mainly found in vacuoles and nuclei and, to lesser extent, in the cytoplasm and plastids, but not in cell walls. X-ray microanalysis confirmed the presence of Cd in vacuoles and nuclei, but failed to detect Cd in any other cell compartment. The advantages and disadvantages of the histochemical and X-ray microanalytical methods for the localization of small amounts of Cd in plants are discussed.