氧化石墨烯对浮萍生长的抑制作用

Growth Inhibition Effect Graphene Oxide on Duckweed Lemna minor L.

以浮萍作为受试生物,分别以质量浓度为1、5、10 mg/L的氧化石墨烯碎片悬浮液,对浮萍进行96 h暴露处理,以分析氧化石墨烯对浮萍生长的影响。结果显示,10 mg/L的氧化石墨烯对浮萍叶片数和湿重的抑制率分别约为35.3%和26.1%,显著(P<0.05)抑制了浮萍的生长;低浓度的氧化石墨烯对浮萍抗氧化酶无明显影响,当其浓度达10 mg/L时,浮萍内超氧化物歧化酶(SOD)过氧化氢酶(CAT)水平明显(P<0.05)升高;过氧化物酶(POD)的活性则随着氧化石墨烯浓度的增加出现"低促高抑"的趋势。研究结果说明,氧化石墨烯在具有环境意义的低浓度下对浮萍无明显抑制作用,但在较高浓度(10 mg/L)下对浮萍具有显著的胁迫效应。

In this study, duckweed Lemna minor L. was selected as a test organism and exposed to graphene oxide with concentrations of 1,5 and 10 mg/L for 96 hours to determine the effects of graphene oxide on the growth and antioxidant enzymes. The results showed that the inhibition ratios of 10 mg/L of gra- phene oxide on fronds number and fresh weight were approximately 35.3 and 26. 1, respectively, suggesting a significant （P 〈 0. 05 ） inhibition. Low level graphene oxide had no obvious influence on antioxidant en- zyme activity, while the activities of SOD and CAT in duckweed increased significantly at 10 mg/L of gra- phene oxide. POD activity showed a trend of ＂promote weakly and inhibited strongly＂ and inhibited severely with 10 mg/L of graphene oxide. Our work indicated that graphene oxide has no remarkable adverse effects on duckweed with an environmental relevant concentration, but exerted stresses at a high concentration （10 mg/L）.