title: Distribution and Translocation of 141Ce (III) in Horseradish.
abstract: OBJECTIVE
  Rare earth elements (REEs) are used in agriculture and a large amount of them contaminate the environment and enter foods. The distribution and translocation of (141)Ce (III) in horseradish was investigated in order to help understand the biochemical behaviour and toxic mechanism of REEs in plants.
  
  
  METHODS
  The distribution and translocation of (141)Ce (III) in horseradish were investigated using autoradiography, liquid scintillation counting (LSC) and electron microscopic autoradiography (EMARG) techniques. The contents of (141)Ce (III) and nutrient elements were analysed using an inductively coupled plasma-atomic emission spectrometer (ICP-AES).
  
  
  RESULTS
  The results from autoradiography and LSC indicated that (141)Ce (III) could be absorbed by horseradish and transferred from the leaf to the leaf-stalk and then to the root. The content of (141)Ce (III) in different parts of horseradish was as follows: root > leaf-stalk > leaf. The uptake rates of (141)Ce (III) in horseradish changed with the different organs and time. The content of (141)Ce (III) in developing leaves was greater than that in mature leaves. The results from EMARG indicated that (141)Ce (III) could penetrate through the cell membrane and enter the mesophyll cells, being present in both extra- and intra-cellular deposits. The contents of macronutrients in horseradish were decreased by (141)Ce (III) treatment.
  
  
  CONCLUSIONS
  (141)Ce (III) can be absorbed and transferred between organs of horseradish with time, and the distribution was found to be different at different growth stages. (141)Ce (III) can enter the mesophyll cells via apoplast and symplast channels or via plasmodesmata. (141)Ce (III) can disturb the metabolism of macronutrients in horseradish.
authors.affiliation: College of Chemistry and Environmental Science, Nanjing Normal University, Nanjing 210097, PR China.
authors.forename: Xiaoshan
authors.initials: X
authors.lastname: Guo
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhou
authors.forename: Tianhong
authors.initials: T
authors.lastname: Lu
authors.forename: Min
authors.initials: M
authors.lastname: Fang
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Huang
mesh_terms: D031215:Armoracia / Q000378:metabolism* / Q000648:ultrastructure; D001345:Autoradiography; D002118:Calcium / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism / Q000648:ultrastructure; D002563:Cerium / Q000378:metabolism*; D002565:Cerium Radioisotopes; D008274:Magnesium / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D011188:Potassium / Q000378:metabolism
chemical_list: D002565:Cerium Radioisotopes; D002563:Cerium; D008274:Magnesium; D011188:Potassium; D002118:Calcium