凤眼蓝生理生化特性对盐酸四环素的响应特征

Effect of tetracycline hydrochloride on physio-biochemical characteristics of Eichhornia crassipes

为了研究凤眼蓝(Eichhornia crassipes)生理生化特性对盐酸四环素(tetracycline hydrochloride, TC·HCl)的响应特征,通过在玻璃温室中进行静态耗竭试验,评价了不同浓度梯度的TC·HCl对凤眼蓝叶片的三种抗氧化酶活性、生长状况以及叶绿素含量的潜在影响,并对凤眼蓝体内TC·HCl的积累进行了研究。结果表明, TC·HCl一次性投加量为10μg·L-1时,对凤眼蓝的生理生化指标性无明显影响;当TC·HCl浓度大于100μg·L-1时,随着TC·HCl在叶片中的累积,组织细胞受到胁迫,抗氧化酶活性升高,敏感度由强到弱依次为过氧化氢酶(CAT)>过氧化物酶(POD)>超氧化物歧化酶(SOD);此外,当TC·HCl浓度大于100μg·L-1时,进入叶片中的TC·HCl提高了凤眼蓝叶片中的生物量以及叶绿素含量,促进了光合作用。与无植物组相比, 10、100、1 000μg·L-1植物组抗生素去除率分别提高了64.16%、72.49%和54.80%。TC·HCl在凤眼蓝各个器官的分布也存在较大差异,根部的TC·HCl含量明显高于叶柄及叶片。综上,凤眼蓝对短时间TC·HCl暴露具有较强的耐受能力,且对TC·HCl也具有较强的去除效果,是一种对TC·HCl污染水体具有较大修复潜力的植物。

This study was to address the potential effect of tetracycline hydrochloride(TC·HCl) on a common wetland plant, Eichhornia crassipes, through monitoring dynamics of antioxidant enzymes, biomass and chlorophyll in leaves, and a study of the accumulation of antibiotics in plants was also included. No apparent effect on leaves were observed under low TC·HCl concentration(<10 μg·L-1), while hormesis occurred at high TC·HCl concentrations(100 and 1 000 μg·L-1) with evidences of physio-biochemical changes in plants. When the concentration of TC·HCl was greater than 100 μg·L-1, the accumulation of TC·HCl in leaves was probably occurred;the tissue cells were under stress. The resulting increases of antioxidant enzyme activities were observed, and the susceptibility ranging from strong to weak is catalase, peroxidase and superoxide dismutase. In addition, when TC·HCl concentration reached 100 μg·L-1, contents of chlorophylls in leaves were enhanced by TC·HCl, promoting photosynthesis of plants. Compared to the control group, the removal rates of TC·HCl in treatment groups(10, 100 and 1 000 μg·L-1 TC·HCl) increased by 64.16%, 72.49% and 54.80%, respectively. The cumulants in different parts of plant varied apparently, and the cumulants in roots were much higher than in stems and leaves. In conclusion, E. crassipes has strong tolerance to short time exposure of TC·HCl in polluted water, and could contribute to the removal of TC·HCl as well, indicating its great remediation potential of TC·HCl-polluted water.