Rico Cyren M, Johnson Mark G, Marcus Matthew A, Andersen Christian P
National Research Council, Research Associateship Program, 500 Fifth Street, NW, Washington, DC 20001, USA.
US Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Western Ecology Division, 200 SW 35th St., Corvallis, OR 97333, USA.
NanoImpact. 2018 Jul;11:156-163. doi: 10.1016/j.impact.2018.08.003.
The effects of cerium oxide nanoparticles (CeO-NPs) on N/N ratio (δN) in wheat and barley were investigated. Seedlings were exposed to 0 and 500 mg CeO-NPs/L (Ce-0 and Ce-500, respectively) in hydroponic suspension supplied with NHNO, NH , or NO . N uptake and δN discrimination (i.e. differences in δN of plant and δN of N source) were measured. Results showed that N content and N abundance decreased in wheat but increased in barley. Ce-500 only induced whole-plant δN discrimination (-1.48‰, P ≤ 0.10) with a simultaneous decrease (P ≤ 0.05) in whole-plant δN (-3.24‰) compared to Ce-0 (-2.74‰) in wheat in NH . Ce-500 decreased (P ≤ 0.01) root δN of wheat in NHNO and NH (3.23 and -2.25‰, respectively) compared to Ce-0 (4.96 and -1.27‰, respectively), but increased (P ≤ 0.05) root δN of wheat in NO (3.27‰) compared to Ce-0 (2.60‰). Synchrotron micro-XRF revealed the presence of CeO-NPs in shoots of wheat and barley regardless of N source. Although the longer-term consequences of CeO-NP exposure on N uptake and metabolism are unknown, the results clearly show the potential for ENMs to interfere with plant metabolism of critical plant nutrients such as N even when toxicity is not observed.
研究了氧化铈纳米颗粒（CeO-NPs）对小麦和大麦氮/氮比（δN）的影响。将幼苗暴露于分别添加0和500 mg CeO-NPs/L（分别为Ce-0和Ce-500）的水培悬浮液中，该悬浮液供应NHNO、NH 或NO 。测量了氮吸收和δN辨别（即植物δN与氮源δN的差异）。结果表明，小麦中的氮含量和氮丰度降低，而大麦中的则增加。与NH 中Ce-0（-2.74‰）相比，Ce-500仅诱导全株δN辨别（-1.48‰，P≤0.10），同时全株δN下降（P≤0.05）（-3.24‰）。与Ce-0（分别为4.96和-1.27‰）相比，Ce-500使NHNO和NH 中小麦的根δN降低（P≤0.01）（分别为3.23和-2.25‰），但与Ce-0（2.60‰）相比，使NO 中麦根δN增加（P≤0.05）（3.27‰）。同步加速器微X射线荧光分析表明，无论氮源如何，小麦和大麦的地上部分均存在CeO-NPs。尽管CeO-NP暴露对氮吸收和代谢的长期影响尚不清楚，但结果清楚地表明，即使未观察到毒性，环境纳米材料也有可能干扰植物对关键植物养分（如氮）的代谢。
