氧化石墨烯暴露对水稻和小麦发芽及幼苗生长的影响

Effects of Graphene Oxide Exposure on Germination and Seedling Growth of Rice and Wheat

摘要: 氧化石墨烯(GO)作为新兴材料，随着其在工业、医学、商业等领域的广泛应用，在生产和应用的过程中将不可避免地进入环境，对植物及生态环境产生一系列影响。为明确GO的植物效应及潜在的生态风险与其作用机制，本实验以我国两种主要粮食作物——水稻、小麦为研究对象，观察种子和幼苗在不同浓度(0、100、200、300、400、500 mg∙L⁻¹) GO胁迫下的生长生理变化。结果表明，胁迫处理5 d后，低浓度(100、200 mg∙L⁻¹) GO胁迫对水稻和小麦发芽无显著影响，高浓度GO胁迫抑制水稻和小麦发芽，且表现出剂量效应关系；在幼苗生长阶段，胁迫处理15 d后，对于水稻，低浓度(100 mg∙L⁻¹) GO胁迫促进根茎伸长，高浓度对根茎伸长起到抑制作用，不同浓度GO胁迫则均抑制小麦根茎伸长，但二者电解质泄漏率均随GO浓度提高而增加；经检测抗氧化系统酶(CAT、POD、SOD)和丙二醛(MDA)后发现两种植物均出现了氧化应激现象，推测GO对水稻和小麦的影响可能主要通过调节植物体内水分含量以及氧化应激作用来实现，该结果为GO的植物效应与作用机制提供了实验数据与实践参考。

Abstract: Graphene oxide (GO), as an emerging material, will inevitably enter the environment during pro-duction and use with its wide application in the fields of industry, medicine and commerce, and has a series of effects on plants and ecological environment. In order to clarify the plant effect and potential ecological risk of GO and its mechanism of action, this experiment takes two main food crops in China, rice and wheat, as research objects, and observes the growth and physiological changes of seeds and seedlings under GO stress at different concentrations (100, 200, 300, 400, 500 mg/L⁻¹). The results showed that low concentration (100, 200 mg∙L⁻¹) GO stress had no significant effect on rice and wheat germination after 5 days of stress treatment. High concentration of GO stress inhibited rice and wheat germination, and showed dose-effect relationship. At the stage of stress treatment for 15 days, for rice, low concentration (100 mg∙L⁻¹) GO stress promoted rhizome elongation; high concentration inhibited rhizome elongation, and different concentrations of GO stress inhibited wheat rhizome elongation. But both electrolyte leakage rates increase with increasing GO concentration. Oxidative stress was observed in both plants after detection of antioxidant enzymes (CAT, POD, SOD) and malondialdehyde (MDA). It is speculated that the effects of GO on rice and wheat is achieved mainly through regulating the water content of plants and ox-idative stress, and the results provide experimental data and practical reference for the plant effect and mechanism of GO.