Subcellular distribution of metals within Brassica chinensis L. in response to elevated lead and Chromium Stress.
Subcellular distribution of metals within Brassica chinensis L. in response to elevated lead and Chromium Stress.
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DOI：
10.1021/jf4005725
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发表时间：
2013-05
影响因子：
6.1
通讯作者：
Zhipeng Wu;K. Mcgrouther;Dongliang Chen;Wei-dong Wu;Hailong Wang
中科院分区：
文献类型：
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作者：
Zhipeng Wu;K. Mcgrouther;Dongliang Chen;Wei-dong Wu;Hailong Wang
采用差速离心法和同步辐射X射线荧光显微探针技术研究了小白菜（Brassica chinensis L.）在高铅和高铬的胁迫下。在含200 mg L（-1）Pb或5 mg L（-1）Cr的营养液中生长的不同组织的亚细胞分级表明，积累在根和芽中的Pb分别有86.7%和76.3%包含在这些区域的细胞壁和液泡中。在根中积累的铬有75.0%分布在细胞壁中，而在地上部中积累的铬有63.1%分布在液泡和细胞壁中。SRXRF分析结果表明，过量Pb胁迫下，Pb、Ca、Cu、Zn在小白菜根皮层和维管束中富集，根表面出现铁锰混合斑块。在铬处理组中，铬，钙，锰，锌主要位于根的皮层，而在茎，只有钙，铜，锌检测到较高水平的皮层区。因此，本研究提供的证据表明，在响应铅和铬胁迫，小白菜使用细胞壁和液泡，以减少这些重金属通过植物的运输，以及限制运输从根到茎。
Differential centrifugation and synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) microprobe were used to study the distribution of the elements in tissue cross sections of pakchoi ( Brassica chinensis L.) under stress of elevated Pb and Cr. Subcellular fractionation of the different tissues grown in a nutrient solution containing 200 mg L(-1) Pb or 5 mg L(-1) Cr showed that 86.7 and 76.3% of the Pb that accumulated in the roots and shoots, respectively, was contained in the cell wall and vacuoles in those areas. Whereas 75.0% of the Cr that accumulated in the root was contained in the cell wall, 63.1% of the Cr that accumulated in the shoot was found in the vacuoles and cell wall. SRXRF analysis revealed that, when pakchoi seedlings were placed under excess Pb stress, the Pb, Ca, Cu, and Zn were concentrated in the cortex and vascular bundle of the root and mixed Fe-Mn plaques were seen on the surface of the pakchoi root. In the Cr treatment group, Cr, Ca, Mn, and Zn were mainly located in the cortex of the root, whereas in the stem, only Ca, Cu, and Zn were detected at higher levels in the cortex area. Thus, this study provides evidence that, in response to Pb and Cr stress, pakchoi uses cell walls and vacuoles to reduce the transport of these heavy metals through the plant, as well as restrict transport from the root to the stem.