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| 曼陀罗对镉的吸收及其亚细胞分布研究 |
| Uptake and subcellular distribution of cadmium in Datura stramonium L. |
| 投稿时间：2018-11-12 |
| DOI：10.13254/j.jare.2018.0314 |
| 中文关键词: 曼陀罗，Cd累积，Cd2+流速，亚细胞分布，迁移系数 |
| 英文关键词: Datura stramonium L, Cd accumulation, Cd2+ flux, subcellular distribution, transfer factor |
| 基金项目:河南省科技攻关计划项目（162102110127）；国家自然科学基金项目（41571320） |
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| 中文摘要: |
| 为研究曼陀罗对重金属镉的耐性机制，以前期筛选的曼陀罗（Datura stramonium L.）为试验材料，通过水培方式探究镉（Cd）胁迫下曼陀罗对Cd的吸收累积特性及其在植株体内的亚细胞分布特征。结果表明：介质中Cd无论低浓度还是高浓度，曼陀罗各部位的Cd含量都表现为根 > 茎 > 叶，但迁移系数差异不显著。曼陀罗根系Cd2+流速在不同位置具有显著差异，其中分生区和伸长区的Cd2+流速显著大于根冠区和成熟区。当介质中Cd浓度由0.1 mg·L-1增至2.5 mg·L-1时，细胞壁和细胞液中Cd含量之和所占比例显著增大。研究表明，曼陀罗根系对Cd2+的吸收主要集中在分生区和伸长区，当介质中Cd浓度较低时，根系中细胞壁对Cd向上运输的限制及茎叶中细胞液对Cd的区室化起重要的作用；当Cd浓度较高时，根部细胞各组分中细胞液所占比重增加，Cd由根系向上迁移，此时茎叶中细胞壁对Cd的固定作用增强，其可能是曼陀罗耐受高Cd胁迫的机制之一。 |
| 英文摘要: |
| To study the tolerance of Datura stramonium L. to Cd, previously selected D.stramonium was used to evaluate Cd uptake and subcellular distribution under Cd stress using ahydroponic experiment. The results showed that the Cd concentration among different parts of D.stramonium decreased in the following order at both low and high Cd concentrations in medium:Root > stem > leaf. Nevertheless, there was no significant difference in the transfer factor. Cd2+ flux was significantly different in different zones of the root surface; the flux of Cd2+ in the meristematic and elongation zones was significantly higher than that in the root cap and maturity zone. When the Cd concentration increased from 0.1 mg·L-1 to 2.5 mg·L-1, the proportion of Cd in cell walls and the soluble fraction increased. Thus, the uptake of Cd by the roots of D.stramonium occurred mainly within the meristematic and elongation zones. When the Cd concentration in medium was low, restriction of Cd transport by cell walls in the roots and compartmentalization by the soluble fraction of cells in the shoots played a vital role in Cd detoxification. When the Cd concentration was high, the proportion of Cd in the soluble fraction of root cells increased, and Cd could migrate to the leaves and stems. Therefore, enhanced Cd immobilization by cell walls in the shoots might serve as a mechanism of Cd tolerance in D.stramonium. |
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