稀土超量积累植物铁芒萁中稀土元素的赋存状态

Chemical Species of Rare Earth Elements in RE Hyperaccumulator Dicranopteris Dichotoma

从稀土矿区和非矿区采集的稀土超量积累植物铁芒萁的叶片分离成醚溶物、水溶物、碱溶物和残余物四个组分。用中子活化分析测定了其中稀土元素的含量 ,发现稀土元素主要存在于残余物 (果胶、半纤维素、纤维素 )中 ,而主要成份为蛋白的碱溶物中稀土含量维持较低水平 ,从而避免了大量稀土对植物正常生理功能造成影响。矿区幼叶醚溶物 (脂肪、色素、蜡等 )和碱溶物中稀土含量明显高于矿区和非矿区的成熟叶片 ,表明稀土元素很可能参与了植物的生理活动。

Leaves of Dicranopteris dichotoma collected from a rare earth ore area and two control areas were separated into ether fractions,water fractions,base fractions and residues.The contents of REEs were determined by instrumental neutron activation analysis (INAA) and found most of RE remained in the residues (pectin,hemicellulose and cellulose).The base fractions which main components were proteins kept relatively low RE contents.So the normal physiological functions were not interfered by the high RE concentrations.The ether fraction (lipids,pigments and wax)and the base fraction of young leaves from rare earth ore area contained more RE than the mature leaves collected from the same site and control areas.This means that REEs probally participate in the physiological movements of the plant.