垂序商陆叶细胞壁结合锰机制研究 |
摘要点击 2110 全文点击 1419 投稿时间:2014-06-09 修订日期:2014-09-03 |
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中文关键词 垂序商陆 锰 细胞壁 吸附 红外光谱 X-射线吸收光谱 |
英文关键词 Phytolacca americana L. manganese cell wall adsorption infrared spectroscopy X-ray absorption fine structure spectroscopy |
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中文摘要 |
垂序商陆是一种典型的锰超积累植物,细胞壁在其累积解毒锰的过程中起了一定的作用. 通过细胞壁吸附实验,研究不同pH和不同锰浓度对细胞壁吸附锰的影响,并采用傅立叶红外光谱及同步辐射X-射线吸收光谱技术探讨了其吸附机制. 结果表明,垂序商陆叶细胞壁吸附锰的最适pH值为5~6; 其吸附行为可用Langmuir模型较好地描述(R2=0.9785),并计算得其最大吸附量为62.50 μmol·g-1. 细胞壁上的羟基(—OH)和羰基(—C=O)是结合锰的主要位点; 锰周围第一配层为氧原子,其配位数为6.3, Mn—O键长为0.216 nm,细胞壁与锰主要以内配层模式相结合. |
英文摘要 |
Phytolacca americana L. (P. americana) is a manganese (Mn) hyperaccumulator and cell wall plays an important role in the accumulation and detoxicity of Mn. We studied the impact of pH and Mn initial concentration on the binding of Mn by the leaf cell wall of P. americana, and explored the binding mechanisms by Fourier Transform Infrared Spectroscopy (FTIR) and synchrotron-based X-ray Absorption Fine Structure (XAFS) Spectroscopy. The results show that the optimum pH of Mn bingding for the leaf cell wall is between 5 and 6. The adsorption behavior of leaf cell wall can be described by Langmuir equation (R2=0.9785) and the maximum adsorption of Mn on the leaf cell wall is 62.50 μmol·g-1. Hydronyl and carbonyl groups are involved in the binding of Mn on the leaf cell wall. The Mn absorbed on the leaf cell wall is bonded by 6.3 oxygen around, and the bond length of Mn—O is 0.216 nm, which indicates the binding mechasnism of Mn to cell wall was inner-sphere complexation. |
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