title: Ultra-small TiO(2) nanoparticles disrupt microtubular networks in Arabidopsis thaliana.
abstract: In spite of the mounting concerns, current understanding of the extent and mechanisms of phytotoxicity of manufactured nanomaterials remains limited. Here we show that in Arabidopsis thaliana, ultra-small anatase TiO(2) nanoparticles cause reorganization and elimination of microtubules followed by the accelerated and 26S proteasome-dependent degradation of tubulin monomers. Similar to other microtubule-disrupting agents, TiO(2) nanoparticles induce isotropic growth of root cells. Because microtubules are essential for the normal function of all eukaryotic cells, these results reveal a potentially important consequence of environmental pollution by this widely used nanomaterial.
authors.affiliation: Plant Physiology, Biochemistry, Molecular Biology Program, Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky 40546, USA.
authors.forename: Songhu
authors.initials: S
authors.lastname: Wang
authors.forename: Jasmina
authors.initials: J
authors.lastname: Kurepa
authors.forename: Jan A
authors.initials: JA
authors.lastname: Smalle
mesh_terms: D017360:Arabidopsis / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D008870:Microtubules / Q000187:drug effects*; D053758:Nanoparticles; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D014025:Titanium / Q000494:pharmacology*; D014404:Tubulin / Q000378:metabolism
chemical_list: D014404:Tubulin; C009495:titanium dioxide; D014025:Titanium; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease