石墨烯对高等植物幼苗的毒性及机理探究

随着石墨烯产品的广泛应用和潜在的环境释放,其对生态环境的影响已引起广泛关注。为探讨石墨烯对高等植物生长的影响,探究了其对黄瓜幼苗和玉米幼苗生长的影响及其致毒机理。结果表明,水培条件下,不同浓度的石墨烯(10、50、100、500、1 000和2 000 mg·L~(-1))处理植物幼苗15 d后,对植物幼苗的生长具有抑制作用。且随着处理时间和石墨烯浓度的增加,植物幼苗生长的所有指标,包括根/地上部鲜重和干重、根长、根尖数、株高和叶面积均相应降低。另外,黄瓜幼苗比玉米幼苗对石墨烯更加的敏感。进一步研究发现,石墨烯与黄瓜幼苗根部直接接触导致的物理损伤、氧化损伤,以及营养耗竭是其致毒机理。而石墨烯对玉米幼苗的致毒机理包括物理损伤和营养耗竭。本研究为石墨烯的环境风险评价提供了基础数据。

Phytotoxicity of Graphene to Higher Plants' Seedlings and Its Mechanisms

With the extensive application and potential release of graphene materials, the negative effects of graphene have attracted great attention. To investigate the effects of graphene on the growth of higher plants, toxicity and related mechanisms of graphene on cucumber and maize seedlings were studied. After exposure to graphene (10, 50, 100, 500, 1 000 and 2 000 mg L^-1) for 15 days under hydroponic conditions, the growth of the seedlings was inhibited. In addition, all the growth indexes, including root/shoot fresh weight and dry weight, root length, number of root tips, plant height and leaf area were also inhibited, and the negative effects were concentration and time-dependent. It was noted that cucumber seedlings were more sensitive to graphene than maize seedlings. Furthermore, physical damage, nutrient depletion, and oxidative stress were the main toxic mechanisms for graphene on cucumber seedlings. While, the toxicity mechanisms of graphene on maize seedlings were physical damage, and nutrient depletion. This study provided useful information for risk assessment of graphene in environment.