Non-invasive microelectrode cadmium flux measurements reveal the spatial characteristics and real-time kinetics of cadmium transport in hyperaccumulator and nonhyperaccumulator ecotypes of Sedum alfredii
Non-invasive microelectrode cadmium flux measurements reveal the spatial characteristics and real-time kinetics of cadmium transport in hyperaccumulator and nonhyperaccumulator ecotypes of Sedum alfredii
复制标题
非侵入性微电极镉通量测量揭示了景天超富集和非超富集生态型中镉转运的空间特征和实时动力学。
DOI：
10.1016/j.jplph.2012.10.014
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发表时间：
2013-02-15
影响因子：
4.3
通讯作者：
Li, Tingqiang
中科院分区：
文献类型：
--
作者：
Sun, Jian;Wang, Ruigang;Li, Tingqiang
本研究旨在利用非侵入性cd选择微电极，研究景天（Sedum alfredii）超富集（HE）和非超富集（NHE）生态型镉的空间特征和实时动力学。与NHE紫荆相比，经氯化镉（CdCl2）预处理后，紫荆的根尖区和根毛细胞内Cd流入量更高，叶柄内Cd流出量也显著高于NHE紫荆。因此，紫荆对吸收的镉具有较高的向茎部转运能力。此外，叶肉组织、分离的叶肉原生质体和完整的液泡在CdCl2处理下表现出Cd的瞬时内流，平均速率明显高于NHE叶肉原生质体。因此，苜蓿的超积累特性表现为在特定的根区（包括根尖区和根毛细胞）快速吸收Cd，以及在质膜和叶肉细胞的质质体中快速的根到茎的转运和高效的Cd透性运输系统。我们认为，非侵入性Cd选择微电极是研究植物组织、细胞和亚细胞水平Cd转运的一种极好的方法，具有高度的空间分辨率。(C) 2012 Elsevier GmbH版权所有。
This study aims to determine the spatial characteristics and real-time kinetics of cadmium transport in hyperaccumulator (HE) and nonhyperaccumulator (NHE) ecotypes of Sedum alfredii using a non-invasive Cd-selective microelectrode. Compared with the NHE S. alfredii, the HE S. alfredii showed a higher Cd influx in the root apical region and root hair cells, as well as a significantly higher Cd efflux in the leaf petiole after root pre-treatment with cadmium chloride (CdCl2). Thus, HE S. alfredii has a higher capability for the translocation of absorbed Cd to the shoot. Moreover, the mesophyll tissues, isolated mesophyll protoplasts, and intact vacuoles from HE S. alfredii exhibited an instantaneous influx of Cd in response to CdCl2 treatment with mean rates that are markedly higher than those from NHE S. alfredii. Therefore, the hyper-accumulating trait of HE S. alfredii is characterized by the rapid Cd uptake in specific root regions, including the apical region and root hair cells, as well as by the rapid root-to-shoot translocation and the highly efficient Cd-permeable transport system in the plasma membrane and mesophyll cell tonoplast. We suggest that the non-invasive Cd-selective microelectrode is an excellent method with a high degree of spatial resolution for the study of Cd transport at the tissue, cellular, and sub-cellular levels in plants. (C) 2012 Elsevier GmbH. All rights reserved.