LANDA, Přemysl, PŘEROSTOVÁ, Sylva, PETROVÁ, Šárka, KNIRSCH, Vojtěch, VAŇKOVÁ, Radomíra, VANĚK, Tomáš. The Transcriptomic Response of Arabidopsis thaliana to Zinc Oxide: A Comparison of the Impact of Nanoparticle, Bulk, and Ionic Zinc. Environmental Science & Technology. 2015, 49(24), 14537-14545. ISSN 0013-936X. E-ISSN 1520-5851

The impact of nanosize was evaluated by comparing of the transcriptomic response of Arabidopsis thaliana roots to ZnO nanopartides (nZnO), bulk ZnO, and ionic Zn2+. Microarray analyses revealed 416 up- and 961 down-regulated transcripts (expression difference >2-fold, p [FDR] < 0.01) after a seven-day treatment with nZnO (average particle size 20 nm, concentration 4 mg L-1). Exposure to bulk ZnO resulted in 816 up- and 2179 down-regulated transcripts. The most dramatic changes (1711 transcripts up- and 3242 down-regulated) were caused by the presence of ionic Zn2+ (applied as ZnSO4 center dot 7H(2)0 at a concentration of 14.14 mg L-1, corresponding to the amount of Zn contained in 4 mg L-1 ZnO). Genes involved in stress response (e.g., to salt, osmotic stress or water deprivation) were the most relatively abundant group of gene transcripts up-regulated by all three Zn treatments while genes involved in cell organization and biogenesis (e.g., tubulins, arabinogalactan proteins) and DNA or RNA metabolism (e.g., histones) were the most relatively abundant groups of down-regulated transcripts. The similarity of the transcription profiles and the increasing number of changed transcripts correlating with the increased concentration of Zn2+ in cultivation medium indicated that released Zn2+ may substantially contribute to the toxic effect of nZnO because particle size has not demonstrated a decisive role.