高浓度U胁迫下植物物质成分的FTIR研究

FTIR Study of Plant Material Compositions Under U Stress of High Concentration

用FTIR对500 mg U·kg-1土壤胁迫下空心莲子草、落葵和菊苣茎叶和根系的物质成分进行测定,用半定量法分析3种植物茎叶和根系红外光谱的差异,探讨高浓度U胁迫对植物物质成分的影响.结果表明:(1)3种植物茎叶和根系吸收峰峰形未发生较大改变,但吸光度变化明显,说明该浓度U对这3种植物的物质成分改变较小,含量改变较大.(2)羟基、羧基和酰胺基吸收峰发生明显位移,说明U胁迫对这些基团有明显影响,它们可能与U的吸收、络合、运输密切相关.(3)半定量分析表明,该浓度U使3种植物羟基、羧基等基团及蛋白质和糖类物质有明显的数量变化,不同植物变化不同,这可能由植物耐受U能力不同所致.因此,FTIR能快速、灵敏地检测植物在高浓度U胁迫下物质成分的变化,能解释植物吸收积累U的影响机理,可作为一种有效手段应用于U等核素对植物效应的研究.

Material compositions of shoots and roots of Alternanthera philoxeroides, Basella rubra and C/chorium intybus L. under stress of 500 mg U ·kg^-1 soil were measured by FTIR and the differences of infrared spectroscopy of the material compositions were analyzed with half-quantitative analysis method in order to probe into the effects of high concentration U on plant material compositions. The results show that the absorption peak shapes of the various parts of the three kinds of plants basically have not great change, but the absorbance have obvious change, indicating that the U concentration does not change the material composition, but change the content; Significant displacements of the absorption peak of hydroxyl group, carboxyl group and amide group have occurred, indicating that the stress of U has a significant effect on these groups which may be closely related to the absorption,complexation, transportation of U ; The half-quantitative analysis show that there are obvious changes in the number of hydroxyl, carboxyl groups, protein and carbohydrate of the three plants, but the changes of different plants are varied, which may be caused by the U tolerance of different plants. Therefore, FTIR can be fast and sensitive detection of changes in the materil compositions under the stress of high concentration of U. It can be used to explain the effect mechanism of plant uptake and accumulation of U, and can be applied as an effective means to the study of effects of U and other radionuclides on plants.