Pb uptake, accumulation, subcellular distribution in a Pb－accumulating ecotype of Sedum alfredii （Hance）

• Published in: Journal of Zhejiang University. Science Vol. 4; no. 4; pp. 474 - 479
• Main Author: 何冰 杨肖娥 倪吾钟 魏幼璋 叶海波
• Format: Journal Article
• Language: English
• Published: 2003
• Subjects: 亚细胞分布; 景天属植物; 生态型; 积聚浓度; 重金属污染
• ISSN: 1009-3095

Lead concentrations in roots, stems and leaves of accumulating and non-accumulating ecotypes of Sedum alfredii (Hance) were studied through a hydroponic experiment with different Pb concentrations sup-plied as Pb( NO3 )2 .Lead concentrations in leaves and stems of the accumulating ecotype were 4-9 times and 3-5 times those of the non-accumulating ecotype, and Pb-accumulated amounts in stems and leaves of theaccumulating ecotype were 4-9 times and 8-1l times higher than those of the non-accumulating ecotype,respectively. The results indicated that the accumulating ecotype had better ability to transport Pb from roots toshoots. The subeellular distributions of Pb in the root, stem and leaf tissues were studied using sucrose differ-ential centrifugation. Approximately 50% of Pb contents was found to be associated with the cell wall fractionin stems of the accumulating ecotype and the percentage increased to 80％ both in roots and leaves, no matter when plants were grown with different levels of Pb. The results indicated that the distribution of Pb on cell walls of the accumulating ecotype could mainly account for the high tolerance to Pb.