title: Phytotoxicity, uptake and transformation of nano-CeO2in sand cultured romaine lettuce.
abstract: 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), nCeO2diminished 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 nCeO2and CePO4in the roots while as nCeO2and 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.
authors.affiliation: Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Yuhui
authors.initials: Y
authors.lastname: Ma
authors.affiliation: College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100093, China.
authors.forename: Shutong
authors.initials: S
authors.lastname: Liu
authors.affiliation: Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Wang
authors.affiliation: Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Junzhe
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: He
authors.affiliation: Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100093, China. Electronic address: ruiyukui@163.com.
authors.forename: Yukui
authors.initials: Y
authors.lastname: Rui
authors.affiliation: Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China. Electronic address: zhangzhy@ihep.ac.cn.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D018533:Biomass; D001711:Biotransformation; D002563:Cerium / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D002734:Chlorophyll / Q000032:analysis / Q000378:metabolism; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry; D009566:Nitrates / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D056928:X-Ray Absorption Spectroscopy
chemical_list: D000975:Antioxidants; D009566:Nitrates; D002734:Chlorophyll; D002563:Cerium; D008315:Malondialdehyde
keywords: CeO(2); Lettuce; Nanomaterials; Toxicity; Transformation