Distribution of elements on tobacco trichomes and leaves under cadmium and sodium stresses
Distribution of elements on tobacco trichomes and leaves under cadmium and sodium stresses
复制标题
DOI：
10.1007/bf03030635
复制
发表时间：
2004-06-30
影响因子：
2.9
通讯作者：
Sano, H
中科院分区：
文献类型：
--
作者：
Choi, YE;Harada, E;Sano, H
当烟草（Nicotiana tabacum）植物暴露于镉中毒水平（0.2 mM Cd）时，它们的毛状体会主动分泌晶体（Choi等人，2001年）。在本研究中，我们研究了Cd和NaCl在毛状体和叶片表面的分布。能量色散x射线（EDX）分析显示，在有毒Cd胁迫下，从毛状体渗出的晶体含有大量的Ca， Mg和Cd，以及低水平的P， S和Mn。毛状体和附着晶体的电子能谱成像（ESI）表明，这些晶体对Ca和Cd的辐射能量比毛状体的头细胞更密集。而毛状体表面和叶表皮内均未检测到Cd。相反，盐（NaCl）处理没有促进晶体形成；相反，它诱导了毛状细胞的异常扩张。虽然Na没有在晶体中积累，但相当数量的Na和Cl都被隔离在长毛的茎细胞中。因此，我们认为烟草毛状体在镉结晶析出过程中发挥了重要作用，但在NaCl胁迫下，长毛状体将这些元素隔离在茎杆内。
When tobacco (Nicotiana tabacum) plants are exposed to toxic level of cadmium (0.2 mM Cd), their trichomes actively excrete crystals (Choi et al., 2001). In this study, we investigated the distribution of Cd and NaCl on trichomes and leaf surfaces. Energy dispersive x-ray (EDX) analysis revealed that, under toxic Cd stress, crystals exudated from the trichomes contained high amounts of Ca, Mg, and Cd, as well as low levels of P, S, and Mn. Electron spectroscopic imaging (ESI) from trichomes and attached crystals showed that these crystals emitted denser radiation energy for Ca and Cd than did the head cells of the trichomes. However, no Cd was detected on the trichome surface itself or within the leaf epidermis. In contrast, treatment with salt (NaCl) did not stimulate crystal formation; instead, it induced the abnormal expansion of trichome cells. Although Na was not accumulated within the crystals, a considerable amount of both Na and Cl was sequestered within the stalk cells of the long trichomes. Therefore, we believe that tobacco trichomes play an important role in Cd crystal exudation through crystallization, but that, under NaCl stress, the long trichomes sequester those elements within their stalks.