title: Uptake, distribution and toxicity of gold nanoparticles in tobacco (Nicotiana xanthi) seedlings.
abstract: Understanding plant interactions with nanoparticles is of increasing importance for assessing their toxicity and trophic transport. The primary objective of this study was to assess uptake, biodistribution and toxicity associated with exposure of tobacco plants (Nicotiana xanthi) to gold nanoparticles (AuNPs). We employed synchrotron-based X-ray microanalysis with X-ray absorption near-edge microspectroscopy and high resolution electron microscopy to localize AuNPs within plants. Results from these experiments reveal that AuNPs entered plants through the roots and moved into the vasculature. Aggregate bodies were also detected within root cell cytoplasm. Furthermore, AuNP uptake was size selective as 3.5 nm AuNP spheres were detected in plants but 18 nm AuNPs remained agglomerated on the root outer surfaces. Finally, leaf necrosis was observed after 14 days of exposure to 3.5 nm AuNPs. Overall, results of this work show the potential for AuNPs to enter plants through size-dependent mechanisms, translocate to cells and tissues and cause biotoxicity.
authors.affiliation: Department of Environmental Health Sciences and NanoCenter, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina, USA.
authors.forename: Tara
authors.initials: T
authors.lastname: Sabo-Attwood
authors.forename: Jason M
authors.initials: JM
authors.lastname: Unrine
authors.forename: John W
authors.initials: JW
authors.lastname: Stone
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Murphy
authors.forename: Soumitra
authors.initials: S
authors.lastname: Ghoshroy
authors.forename: Doug
authors.initials: D
authors.lastname: Blom
authors.forename: Paul M
authors.initials: PM
authors.lastname: Bertsch
authors.forename: Lee A
authors.initials: LA
authors.lastname: Newman
mesh_terms: D006046:Gold / Q000493:pharmacokinetics* / Q000633:toxicity*; D053768:Metal Nanoparticles / Q000633:toxicity*; D010316:Particle Size; D018517:Plant Roots / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D036226:Seedlings / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism*; D014018:Tissue Distribution; D014026:Nicotiana / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism*; D056928:X-Ray Absorption Spectroscopy
chemical_list: D006046:Gold