Uptake and Distribution of Ultrasmall Anatase TiO₂Alizarin Red S Nanoconjugates inArabidopsis thaliana

Abstract

While few publications have documented the uptake of nanoparticles in plants, this is the first study describing uptake and distribution of the ultra-small anatase TiO 2 in the plant model system Arabidopsis. We modified the nanoparticle surface with Alizarin red S and sucrose, and demonstrated that nanoconjugates traversed cell walls, entered into plant cells, and accumulated in specific subcellular locations. Optical and X-ray fluorescence microscopy co-registered the nanoconjugates in cell vacuoles and nuclei. KeywordsAnatase TiO 2 nanoparticles; TiO 2 nanoconjugates; Arabidopsis thaliana; X-ray fluorescence microscopy (XFM)The application of nanotechnology to plant systems has lagged behind nanomedicine and nanopharmacology in spite of its potential to generate new tools for the delivery of fertilizers, herbicides and insecticides 1 , new ways to manipulate plant genomes 2 and new methods to capture and isolate plant natural products. Compared to the thousands of studies describing the uptake and trafficking of nanoparticles (NPs) in biological systems other than plants, less than twenty reports discussed NP uptake by plant species. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] These studies involved different plant species and different types of NPs which were delivered to intact plants, dissected plant organs or protoplasts using a wide range of application methods. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Despite the absence of systematic analyses, it has been determined that plants can take up NPs from the environment and transport them through the vascular system to various shoot organs. 4,9,15 However, little is known about the uptake mechanisms involved or the subcellular localization and distribution of the internalized NPs. 16 Uptake efficiency has also Figure S1), and show additional data describing NC distribution and localization in roots, hypotocyls and cotyledons (Figures S2, S3 and S4). This material is available free of charge via the Internet at http://pubs.acs.org. Here, we report on the uptake and localization of anatase titanium dioxide (TiO 2 ) NPs smaller than 5 nm in the plant model system Arabidopsis thaliana. We chose to study the Col-0 accession because this is the most commonly used ecotype within the Arabidopsis research community. 22 The numerous resources developed for this genetic background 23,24 will not only facilitate future analyses of the molecular mechanisms of uptake, intracellular localization and trafficking of NPs, but will also provide opportunities for NP-mediated manipulations of the Arabidopsis genome. In addition, the well-characterized Arabidopsis null mutants and overexpression lines for enzymes of various biochemical pathways offer the possibility for the targeted in planta chemical modification of NP surface with pathway intermediates. TiO 2 NPs with average diameters of 2.8 ± 1.4 nm and NP dispersity of 43% (see Supporting information) were synthesized by a low-temperature alkaline hydrolysis route as described previously 2...

Soybean susceptibility to manufactured nanomaterials with evidence for food quality and soil fertility interruption

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Phytotoxicity of ZnO nanoparticles and the released Zn(II) ion to corn (Zea mays L.) and cucumber (Cucumis sativus L.) during germination

“…Pollutants may not affect germination if they cannot pass through seed coats. This is the explanation that seed germination was not greatly affected by nanoparticles in many previous studies (Kurepa et al 2010;Lin and Xing 2007;Wang et al 2012). Therefore, it is necessary to investigate whether and to what extent seed coats can alleviate the phytotoxic effects of nanoparticles on germination and root elongation.…”

“…Seed coats with selective permeability and secrete seed mucilage are considered to play a very important role in protecting the embryo from harmful external factors (Kurepa et al 2010;Lin and Xing 2007). Pollutants may not affect germination if they cannot pass through seed coats.…”

Highly efficient uptake of ultrafine mesoporous silica nanoparticles with excellent biocompatibility by Liriodendron hybrid suspension cells

“…Our results indicate that ultrafine MSNs hold considerable potential as nano-carriers of extracellular molecules, and can be used to investigate in vitro gene-delivery in plant cells. Along with developments in the application of nanotechnology from animal science and medical research to plant science research, the impact of engineered nanomaterials on plant systems has attracted increasing attention, the areas including (i) the delivery of fertilizers, herbicides, pesticides and exogenous genes, (ii) the improvement of the growth of plants, and (iii) nanotoxicity research for plant cells [1][2][3][4][5][6][7][8][9][10]. However, compared with mammalian cells, the plant cell wall which is composed of cross-linked polysaccharides (cellulose, hemicelluloses, and pectin) represents an extra barrier surrounding the cell membrane that hinders the passage of nanoparticles into plant cells.…”