水稻籽实中Pb的分布及其结合形态  

The Distribution and Binding Forms of Lead in Rice Seed

作　　者：杨居荣[1] 何孟常[1] 查燕[1] 刘虹[1] 

机构地区：[1]北京师范大学环境科学研究所

出　　处：《农业环境保护》2001年第3期129-132,共4页Agro-Environmental Protection

基　　金：国家自然科学基金资助项目 (49771069)

摘　　要：采用组织化学及生物化学分析方法，研究了重金属污染区水稻籽实中 Pb的分布及其结合形态。结果表明， Pb在籽实各形态结构中的浓度分布不均匀，胚和种皮中的浓度显著高于胚乳和颖壳。就 Pb总量而言，胚乳中的比例最高； Pb在籽实的主要营养成分中，以蛋白质中的分布比例最高，可达 83％，脂肪中甚微；在 4种主要类型蛋白质中，以谷蛋白和球蛋白中的比例较高。凝胶层析的结果表明，蛋白质－ Pb结合体的表观分子量为 54.5KD,蒸煮及体外消化酶的处理下，前者易分解，出现分子量较小的结合物。The distribution and binding forms of Pb in polluted rice seeds were studied using both methods of histochemistry and biochemistry. The results indicated that the distribution of Pb in rice grains was very uneven. The concentrations of Pb in either embryo or seed capsule was higher than that in endosperm and chaff, respectively. However, the accumulated contents of lead was chiefly in the endosperm. The percentage of protein－ binding forms in total contents of rice grains for Pb was the highest and reached to 83％ , while the percentage of fat－ binding forms for Pb was lower. In terms of fractionation of albumin, globulin, prolamin and glutein, it was shown that Pb was mainly bound with glutelin and globulin. Separation of proteins by Sephadex chromatography and subsequent analysis by atomic absorption spectroscopy revealed that apparent molecular weights of protein－ bound Pb were 54.5KD and 5.50 KD, respectively. After treatment of cooking and enzyme digestion, high molecular weight protein－ binding Pb was broken down into low molecular weight complex (5.50KD).

关 键 词：水稻籽实 铅 结合形态 稳定性 分布 作物监测 

分 类 号：X835[环境科学与工程—环境工程] S511[农业科学—作物学]