磺化石墨烯对小麦幼苗生长及生理生化指标的影响

Effect of Sulfonated Graphene on Seedling Growth and Physiological and Biochemical Indices of Wheat

随着石墨烯生产量和使用量的不断增大,其对生态环境的风险逐渐引起了环境学家的关注。采用水培试验,探究了磺化石墨烯(SGO)对小麦幼苗的生长、抗氧化酶活性及脂质过氧化的影响。结果表明:在培养10 d后,低浓度磺化石墨烯对小麦根系的生长有显著促进作用(P<0.05),200 mg·L-1浓度处理与对照处理相比提高了84.3%,随着浓度增加促进作用逐渐减弱,1 000 mg·L-1时与对照相比提高了19.9%。但对小麦地上部的生长没有影响。磺化石墨烯处理的小麦幼苗根系和叶片组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)及丙二醛(MDA)都呈现先下降后上升的趋势。当磺化石墨烯浓度低于200 mg·L-1时,处理组小麦抗氧化酶的活性及MDA含量相对于对照处理大都有所降低,说明低浓度时磺化石墨烯没有对小麦的生长产生氧化胁迫,这与磺化石墨烯可能具有一定的抗氧化能力有关,而高浓度时由于产生氧化胁迫使各项生理生化指标逐渐上升。本实验结果为石墨烯材料对植物的毒理学研究提供了基础数据。

With the increasing consumption and production amount of graphene, its risk to ecological environment attracts growing concern of environmentalists. The effect of sulfonated graphene （SGO） on seedling growth, antiox- idant enzyme activities and lipid peroxidation content of wheat was investigated based on hydroponic experiments. The results showed that sulfonated graphene at low concentrations significantly promoted wheat root length （P〈0.05） after culturing for 10 d. Compared to the control treatment, the root length was increased by 84.3% at a concentration of 200 mg-L-1. However, the promotion effect gradually decreased as the concentration increased, and the root length was increased by 19.9% at a concentration of 1 000 mg-L-1. No obvious effect was observed on wheat shoot length. The activities of superoxide-dismutase （SOD）, catalase （CAT）, peroxidase （POD） and the content of malondialdehyde （MDA） in roots and leaves were decreased at first and then increased after 10 d. These indices at graphene concentrations below 200 mg-L~ were higher than those of the control treatment, indicating that sulfonated graphene did not generate oxidative stress at low concentrations, which may be due to the antioxi- dant capacity of sulfonated graphene. Sulfonated graphene generated oxidative stress at high concentrations, resul- ting in the increasing physiological and biochemical indices. These results have provided basic data for plant toxi- cology of graphene.