Effect of cadmium on the chemical composition of xylem exudate from oilseed rape plants (Brassica napus L.)
Effect of cadmium on the chemical composition of xylem exudate from oilseed rape plants (Brassica napus L.)
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DOI：
10.1111/j.1747-0765.2007.00214.x
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发表时间：
2008-02-01
影响因子：
2
通讯作者：
Chino, Mitsuo
中科院分区：
文献类型：
--
作者：
Nakamura, Shin-ichi;Akiyama, Chieko;Chino, Mitsuo
植物修复是去除农田土壤中镉的一种很好的技术。为了有效地从这些土壤中去除Cd，Cd离子必须被输送到地上部以便以后收获。然而，Cd通过木质部导管转运到茎器官的机制尚未阐明。我们选择了油菜(Brassica napus L.)并建立了一种收集这些植物木质部分泌物的方法。Cd处理3d后，木质部分泌物中Cd的浓度分别为6.5mU/L和16mU/L，其中10mU/L的L和30mU/L的L处理后，木质部分泌物中的Cd浓度分别为6.5mU/L和16mU/L。在木质部分泌物中检测到Cd，表明Cd通过木质部导管向器官移动。研究了不同镉处理对油菜木质部分泌物中氨基酸、有机酸和蛋白质组成的影响。检测到的氨基酸和有机酸水平足以结合通过木质部运输的Cd。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法分析表明，镉处理后渗出液中相对分子质量为36 kDa和45 kDa的蛋白质明显增多。讨论了这些化合物与木质部分泌物中Cd结合的可能性。
Phytoremediation is a good technique for removing cadmium (Cd) from farmland soils. To remove Cd from these soils effectively, it is necessary for Cd ions to be transported to the shoot organs for later harvest. However, the mechanism of Cd translocation to shoot organs via xylem vessels has not yet been elucidated. We selected oilseed rape plants (Brassica napus L.) and established a method to collect xylem exudates from these plants. After 3 days of Cd treatment (10 mu mol L-1 and 30 mu mol L-1) the Cd concentrations in the xylem exudates were approximately 6.5 mu mol L-1 and 16 mu mol L-1, respectively. The detection of Cd in the xylem exudate indicated that Cd was moving to shoot organs via xylem vessels. The effect of these Cd treatments on the amino acid, organic acid and protein composition of xylem exudates from oilseed rape plants was investigated. The level of amino acids and organic acids detected was enough to bind Cd transported via the xylem. Sodium dodecylsulfate-polyacrylamide gel electrophoresis analysis revealed that proteins with molecular weights of 36 kDa and 45 kDa clearly increased in the exudates with Cd treatment. The possibility that these compounds are binding Cd in the xylem exudates was discussed.