镉对圆锥南芥锌的吸收、亚细胞分布和化学形态影响

Effects of Cadmium on Uptake,Subcellular Distribution and Chemical Form of Zinc in Arabis paniculata Franch.

通过营养液培养并采用差速离心技术和化学试剂逐步提取法,分析了Cd对圆锥南芥Arabis paniculata Franch.叶片和根系中Zn的吸收、亚细胞分布和化学形态的影响。结果表明,Cd的添加不会抑制圆锥南芥的生长及对Zn的吸收。Zn在圆锥南芥中以多种化学形态存在;叶片中乙醇、水、NaCl、HAc提取态Zn分配比例较均匀;根系中主要以乙醇提取态和NaCl提取态为主,HAc与HCl提取态Zn的绝对含量与所占的百分比均较低,表明圆锥南芥中的Zn主要以无机酸盐以及氨基酸盐存在。对圆锥南芥Zn的亚细胞分布结果表明,叶片和根系中的Zn主要贮存于细胞壁中其次为细胞核,两者所占的比例分别为65%～83.5%和42.7%～87.3%,且Cd的添加提高了细胞壁中Zn的比例,促进了Zn向细胞壁中的转移。但Cd的添加对Zn的化学形态变化不明显。

Using the differential centrifugation technique and sequential chemical extraction method,effects of Cd on subcellular distribution and chemical form of Zn in multi-metal hyperaccumulator Arabis paniculata Franch under nutrient solution culture were analyzed.Results show that the biomass of A.paniculata has no significant variance increased between before transplant and with Zn/Cd treated 21 days（p0.05）.The cadmium in the nutrient solution has no obvious influence on Zn absorption.NaCl-,ethanol-,water-,HAc-extractable Zn are the predominant fractions in leaves of the plant,NaCl-,ethanol-extractable Zn are predominat fractions in root.Other chemical forms are very low in content.Zn is mainly distributed in cell wall and in karyon which suggests that cell wall and karyon in the plant are major storage for Zn.The cadmium in the nutrient solution has heightened the percentage of Zn in the cell wall and promoted the transportation of Zn to the cell wall,but it has no obvious influence on subcellular distribution and chemical form of Zn in A.paniculata Franch.