Application of quantitative fluorescence and absorption-edge computed microtomography to image metal compartmentalization in Alyssum murale
Application of quantitative fluorescence and absorption-edge computed microtomography to image metal compartmentalization in Alyssum murale
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DOI：
10.1021/es0492034
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发表时间：
2005-04-01
影响因子：
11.4
通讯作者：
Sparks, DL
中科院分区：
文献类型：
--
作者：
McNear, DH;Peltier, E;Sparks, DL
本文表明，基于同步辐射的荧光和吸收边缘计算机断层扫描（CMT）是非常适合于确定超积累植物组织中的金属的区室化和浓度。荧光CMT的完整的叶，茎，根样品显示，镍集中在茎和叶的真皮组织，并与锰，在不同的区域与富钙的毛状体上的镍超富集植物Alyssum murale“Kotodesh”的叶表面。金属富集也观察到较细的根，茎，叶的维管系统，但没有从粗根，其中有一个良好的相关金属涂层。吸收边缘CMT显示的三维分布的最高金属浓度和验证，表皮本地化和Ni和Mn共定位在毛状体基地的现象，发生在整个叶片，并可能有助于显着的金属解毒和存储。镍也观察到在叶尖，可能是由于释放过量的镍与guttation流体。这些结果是一致的运输模型，其中镍是从土壤中去除的细根，通过茎木质部进行到叶，并分布在整个叶的静脉真皮组织，毛状体基地，在某些情况下，叶尖。
This paper shows that synchrotron-based fluorescence and absorption-edge computed microtomographies (CMT) are well-suited for determining the compartmentalization and concentration of metals in hyperaccumulating plant tissues. Fluorescence CMT of intact leaf, stem, and root samples revealed that Ni concentrated in stem and leaf dermal tissues and, together with Mn, in distinct regions associated with the Ca-rich trichomes on the leaf surface of the nickel hyperaccumulator Alyssum murale "Kotodesh". Metal enrichment was also observed within the vascular system of the finer roots, stem, and leaves but absent from the coarser root, which had a well-correlated metal coating. Absorption-edge CMT showed the three-dimensional distribution of the highest metal concentrations and verified that epidermal localization and Ni and Mn colocalization at the trichome base are phenomena that occurred throughout the entire leaf and may contribute significantly to metal detoxification and storage. Ni was also observed in the leaf tips, possibly resulting from release of excess Ni with guttation fluids. These results are consistent with a transport model where Ni is removed from the soil by the finer roots, carried to the leaves through the stem xylem, and distributed throughout the leaf by the veins to the dermal tissues, trichome bases, and in some cases the leaf tips.