title: Xylem and Phloem Based Transport of CeO2Nanoparticles in Hydroponic Cucumber Plants.
abstract: Uptake and translocation of manufactured nanoparticles (NPs) in plants have drawn much attention due to their potential toxicity to the environment, including food webs. In this paper, the xylem and phloem based transport of CeO2NPs in hydroponic cucumber plants was investigated using a split-root system. One half of the root system was treated with 200 or 2000 mg/L of CeO2NPs for 3 days, whereas the other half remained untreated, with both halves sharing the same aerial part. The quantitative distribution and speciation of Ce in different plant tissues and xylem sap were analyzed by inductively coupled plasma-mass spectrometry, transmission electron microscope, X-ray absorption near edge structure, and X-ray fluorescence. Results show that about 15% of Ce was reduced from Ce(IV) to Ce(III) in the roots of the treated-side (TS), while almost all of Ce remained Ce(IV) in the blank-side (BS). The detection of CeO2or its transformation products in the xylem sap, shoots, and BS roots indicates that Ce was transported as a mixture of Ce(IV) and Ce(III) from roots to shoots through xylem, while it was transported almost only in the form of CeO2from shoots back to roots through phloem. To our knowledge, this is the first report of root-to-shoot-to-root redistribution after transformation of CeO2NPs in plants, which has significant implications for food safety and human health.
authors.affiliation: Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Yuhui
authors.identifier: http://orcid.org/0000-0002-7031-4596
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Key Laboratory for Biomedical 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: Key Laboratory for Biomedical 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 Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, China.|School of Physical Sciences, University of the Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Yayun
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Key Laboratory for Biomedical 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 Biomedical 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 Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Changjian
authors.initials: C
authors.lastname: Xie
authors.affiliation: Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Wenhe
authors.initials: W
authors.lastname: Luo
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: Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Lirong
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Chai
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai 201204, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Yang
mesh_terms: D001692:Biological Transport; D002563:Cerium / Q000737:chemistry; D018553:Cucumis sativus; D018527:Hydroponics; D053758:Nanoparticles / Q000737:chemistry; D052585:Phloem; D018517:Plant Roots / Q000737:chemistry; D052584:Xylem
chemical_list: D002563:Cerium