摘要
纳米颗粒的大量生产和应用增加了其环境释放风险,为此以不同浓度的纳米ZnO(0、1、10mg·L-1和50mg·L-1)处理浮萍(LemnaminorL.)7d,分析了纳米颗粒对植物D665/D665a值(叶绿素与脱镁叶绿素的比率)以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和Na+K+-ATP酶(Na+K+-ATPase)活性的影响,并对纳米ZnO的聚集性与溶解性进行了测试。研究结果显示,浓度为50mg·L-1的纳米颗粒显著抑制D665/D665a值和Na+K+-ATPase活性,而抗氧化酶活性则显著升高;纳米颗粒在培养液中易发生聚集作用而沉积,12h后基本上完全沉积到底部。结果说明,50mg·L-1的纳米ZnO对浮萍产生了显著的胁迫作用,其对浮萍的毒性作用主要来源于其溶出的Zn2+。
The extensive production and application of nanoparticles increase the risk of their environmental release. In this study, duckweed （Lemna minor L.）was exposed to ZnO nanoparticles at different doses（0, 1, 10 mg·L-1 and 50 mg·L-1）for 7 d. The influences of the nanoparticles on D665/D665a（ratio of chlorophyll and phoeophytin）and activities of SOD, CAT, POD and Na＋K＋-ATPase were investigated. In addition, aggregation and dissolution of ZnO nanoparticles were tested. The results showed that the activities of SOD, CAT and POD were significantly increased at 50 mg·L-1 nanoparticle concentration and decreased when treated with ZnSO4 （Zn2＋ 10 mg·L-1）, indicative of an antioxidant stress from the nanoparticles. Whereas, D665/D665a and the activity of Na＋K＋-ATPase were significantly suppressed. ZnO nanoparticles were inclined to aggregate and precipitate in the culture media, and all nanoparticles settled within 12 h. The concentrations of Zn2＋ dissolved from the nanoparticles in the 1 mg·L-1, 10 mg·L-1 and 50 mg·L-1 groups were 0.62 mg·L-1, 1.86 mg·L-1 and 2.76 mg·L-1, re- spectively, and they were not in proportion to the nanoparticles added to the culture media. The results indicated that 50 mg·L-1 nanoparticles could bring an evident stress to duckweed（Lemna minor L.）. The source of toxicity may mainly be the Zn2＋ released by the ZnO nanoparticles.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2012年第9期1690-1695,共6页
Journal of Agro-Environment Science
基金
山东省优秀中青年科学家科研奖励基金(BS2010SF005)
教育部新世纪优秀人才支持计划(NCET-08-0877)
