水环境中三氯生残留对轮叶黑藻的生态毒性效应

Ecotoxicological effects of triclosan on Hydrilla verticillata in water

随着三氯生(TCS)在水体环境样品中不断被检出,其对水生生态系统的毒害效应引起了日益广泛关注。采用毒理学实验方法,研究了TCS低浓度长期暴露对轮叶黑藻的生态毒性效应。结果表明,0.05~0.5 mg·L^-1TCS暴露下,轮叶黑藻体内均有不同程度的TCS残留,其中0.1 mg·L^-1TCS处理组中植株体内TCS含量最大。与对照相比,轮叶黑藻叶片中叶绿素含量在整个暴露周期内呈现出抑制-促进-抑制的变化趋势,茎部叶绿素含量在暴露初期被显著抑制随后逐渐回升。植株叶片内可溶性蛋白含量呈现促进-抑制-促进的趋势,而茎部可溶性蛋白含量的影响则呈现出先促进后抑制的趋势。此外,TCS暴露对植株体内抗氧化防御系统具有破坏作用,且TCS对植株叶片和茎部抗氧化酶活性的影响具有差异性。上述结果为有效评估水体环境中TCS的生态风险提供了毒理学数据和理论依据。

As triclosan(TCS)is detected continuously in water samples recently,more and more attentions focus on its toxic effects in aquatic ecosystems.Toxicology experiment methods were used to investigate the ecotoxicological effects of low concentration TCS on Hydrilla verticillata,a typical submerged plant,during a long-term exposure time.The results showed that TCS was detected in H.verticillata with the exposure of 0.05-0.5 mg·L^-1 TCS in 28 d.The highest concentration of TCS in H.verticillata was detected in the 0.1 mg·L^-1 TCS treatment.Compared with that in the control,foliar chlorophyll content of H.verticillata showed a trend of inhibitionpromotion-inhibition during the whole exposure period,while the chlorophyll content of stems was significantly inhibited at the early stage and increased gradually at the end of exposure stage.The content of soluble protein in the leaves showed a promotion-inhibition-promotion trend,while that in stems showed a trend of promotion and then inhibition.The antioxidant defense system of H.verticillata was disturbed by TCS,with the destructive effect of TCS on the antioxidant enzymes in leaves and stems of plants being significantly different.Our results provide toxicological data and theoretical basis for effective assessment of the ecological risk of TCS in water environment.