空心莲子草对铀的吸附及抗氧化酶活性的动态变化

Absorption of Alternanthera philoxeroides to Uranium and the Dynamic Changes of its Antioxidant Enzyme Activity

以空心莲子草为研究对象,在不同浓度铀(0、40、80、100、120、250μmol/L)水培处理条件下,研究空心莲子草对铀的动态积累以及120μmol/L铀处理条件下,空心莲子草根部、茎叶的超氧化物歧化酶(Su-peroxide dismutase,SOD)、过氧化物酶(Peroxidase,POD)、过氧化氢酶(Catalase,CAT)活性的动态变化。结果表明,铀在空心莲子草不同部位的累积量和吸附平衡点不同。空心莲子草对铀的积累主要在根部,在茎叶部的累积量极少。在铀处理5 d时根部铀的积累量达到高峰,而在茎叶部铀的积累量在处理2 d时达到高峰。在120μmol/L铀处理条件下,空心莲子草根部和茎叶部的SOD、POD、CAT活性随铀处理时间延长,其变化不同。铀在根部和茎叶部积累量最高时,其SOD活性均比未处理的对照低;POD活性均出现在其动态变化中的第二个峰值;而CAT在根部和茎叶部的变化不同。

Dynamic accumulation of Alternanthera philoxeroides to uranium at different concentrations（0,40,80,100,120,250 μmol/L） and dynamic changes of SOD,POD,CAT of root,stem and leaves at the uranium concentration of 120 μmol/L were studied under water culture condition.The results showed that the accumulation and adsorption equilibrium point of the different part of Alternanthera philoxeroides to uranium varied.A majority of uranium accumulated in root of Alternanthera philoxeroide whereas only few accumulated in stem and leaves.The peak of uranium accumulation in root was found on the fifth day of uranium treatment.While the peak of uranium accumulation in stem and leaves were found on about the second day.The dynamic changes of SOD,POD and CAT activities were different under the uranium treatment of 120 μmol/L.SOD activities were lower than that of control when the accumulation of uranium in roots,stem and leaves were largest;POD activities all appeared at the second peak of its dynamic changes,but the changes of CAT activities in roots and leaves were different.