Determination of tobacco alkaloids in single plant cells by capillary electrophoresis
Determination of tobacco alkaloids in single plant cells by capillary electrophoresis
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DOI：
10.1016/s0021-9673(01)00627-6
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发表时间：
2001-05-11
影响因子：
4.1
通讯作者：
Bächmann, K
中科院分区：
文献类型：
--
作者：
Lochmann, H;Bazzanella, A;Bächmann, K
建立了一种毛细管电泳直接紫外检测法测定植物样品中烟碱、去甲烟碱和假木贼碱的新方法。发现在灵敏度和分离效率方面，含有高浓度柠檬酸以在pH 3.6下提供良好缓冲能力的电解质是最合适的。在此低pH下，烟草生物碱以阳离子形式存在，显示出高迁移率和增加的UV吸收。该系统已用于烟草单表皮叶细胞中烟碱的分析。仅测定了尼古丁的空泡浓度，因为空泡占表皮细胞总体积的95%以上。示出了用于在pi范围内的液泡样品的尼古丁分析的样品采集和制备的程序。结果表明，尼古丁从叶基部到叶尖呈梯度分布，叶尖细胞中的尼古丁浓度较高。与同时测量的含有所有类型细胞、组织和隔室的散装叶样品相比，表皮细胞中的浓度要高得多。由于尼古丁是烟草中抵抗昆虫的主要防御物质，并且表皮是暴露最多的叶组织，因此该结果在生理学上是合理的。(C)2001爱思唯尔科技有限公司。保留所有权利。
A new capillary electrophoresis system with direct UV detection for the analysis of the tobacco alkaloids nicotine, nornicotine and anabasine in plant microsamples was developed. An electrolyte containing a high concentration of citric acid to provide good buffer capacity at pH 3.6 was found to be most suitable in terms of sensitivity and separation efficiency. At this low pH the tobacco alkaloids are present in cationic form, showing high mobility and increased UV absorption. This system was used for the analysis of nicotine in single epidermal leaf cells of tobacco plants. Only vacuolar concentrations of nicotine were determined, as the vacuole occupies >95% of the entire volume in epidermal cells. The procedure of sample acquisition and preparation for nicotine analysis of vacuolar samples in the pi range is shown. The results indicate a gradient of nicotine from the leaf base to the tip with higher concentrations present in the cells at the tip. Compared to simultaneously measured bulk leaf samples containing all types of cells, tissues and compartments, the concentrations in epidermal cells are much higher. As nicotine is the major defence substance against insects in tobacco and the epidermis is the most exposed leaf tissue this result is physiologically plausible. (C) 2001 Elsevier Science B.V. All rights reserved.