Phytotoxicity, uptake and transformation of nano-CeO₂ in sand cultured romaine lettuce

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• 作者：Peng Zhang^a ; Yuhui Ma^a ; Shutong Liu^b ; Guohua Wang^a ; Junzhe Zhang^a ; Xiao He^a ; Jing Zhang^c ; Yukui Rui^b ; ^{ruiyukui@163.com} ; Zhiyong Zhang^a ; ^{zhangzhy@ihep.ac.cn}
• 关键词：CeO2 ; Nanomaterials ; Lettuce ; Toxicity ; Transformation
• 刊名：Environmental Pollution
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：220
• 期：part_PB
• 页码：1400-1408
• 全文大小：1982 K
• 卷排序：220

文摘

Toxicity and uptake of nano-CeO2 (nCeO2) in edible vegetables are not yet fully understood. In the present study, we grew romaine lettuce in sand amended with nCeO2. At high concentrations (1000 and 2000 mg/kg), nCeO2 diminished the chlorophyll content by 16.5% and 25.8%, respectively, and significantly inhibited the biomass production. nCeO2 (≥100 mg/kg) altered antioxidant enzymatic activities and malondialdehyde levels in the plants. nCeO2 (≥500 mg/kg) triggered a remarkable increase of nitrate-N level in the shoots, which can be converted to toxic nitrite in humans thereby posed risk to human health. Concentration dependent accumulation of Ce in the plant tissues was observed. X ray absorption near edge spectroscopy (XANES) results indicate that Ce presented as nCeO2 and CePO4 in the roots while as nCeO2 and Ce carboxylates in the shoots. Chelation of Ce3+ by citric acid or precipitation of Ce3+ by PO43− reduced the translocation and toxicity of nCeO2, indicating that release of Ce3+ played a critical role in the toxicity nCeO2.