title: Observation of yttrium oxide nanoparticles in cabbage (Brassica oleracea) through dual energy K-edge subtraction imaging.
abstract: BACKGROUND
  The potential transfer of engineered nanoparticles (ENPs) from plants into the food chain has raised widespread concerns. In order to investigate the effects of ENPs on plants, young cabbage plants (Brassica oleracea) were exposed to a hydroponic system containing yttrium oxide (yttria) ENPs. The objective of this study was to reveal the impacts of NPs on plants by using K-edge subtraction imaging technique.
  
  
  RESULTS
  Using synchrotron dual-energy X-ray micro-tomography with K-edge subtraction technique, we studied the uptake, accumulation, distribution and concentration mapping of yttria ENPs in cabbage plants. It was found that yttria ENPs were uptaken by the cabbage roots but did not effectively transferred and mobilized through the cabbage stem and leaves. This could be due to the accumulation of yttria ENPs blocked at primary-lateral-root junction. Instead, non-yttria minerals were found in the xylem vessels of roots and stem.
  
  
  CONCLUSIONS
  Synchrotron dual-energy X-ray micro-tomography is an effective method to observe yttria NPs inside the cabbage plants in both whole body and microscale level. Furthermore, the blockage of a plant's roots by nanoparticles is likely the first and potentially fatal environmental effect of such type of nanoparticles.
authors.affiliation: Materials Science and Engineering, Texas A&M University, College Station, TX, 77843-3123, USA.
authors.forename: Yunyun
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Mechanical Engineering, Texas A&M University, College Station, TX, 77843-3123, USA.
authors.forename: Carlos
authors.initials: C
authors.lastname: Sanchez
authors.affiliation: Materials Science and Engineering, Texas A&M University, College Station, TX, 77843-3123, USA.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yue
authors.affiliation: Department of Plant Science, California State University, Fresno, CA, 93740, USA.
authors.forename: Mauricio
authors.initials: M
authors.lastname: de Almeida
authors.affiliation: Department of Plant Science, California State University, Fresno, CA, 93740, USA.
authors.forename: Jorge M
authors.initials: JM
authors.lastname: González
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
authors.forename: Dilworth Y
authors.initials: DY
authors.lastname: Parkinson
authors.affiliation: Materials Science and Engineering, Texas A&M University, College Station, TX, 77843-3123, USA. hliang@tamu.edu.|Mechanical Engineering, Texas A&M University, College Station, TX, 77843-3123, USA. hliang@tamu.edu.
authors.forename: Hong
authors.initials: H
authors.lastname: Liang
mesh_terms: D001937:Brassica / Q000378:metabolism*; D053758:Nanoparticles / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D018547:Plant Stems / Q000378:metabolism; D055114:X-Ray Microtomography / Q000379:methods; D015019:Yttrium / Q000378:metabolism*
chemical_list: D015019:Yttrium; C091417:yttria
keywords: Accumulation; Cabbage; K-edge subtraction imaging; Synchrotron X-ray micro-tomography; Yttria nanoparticles