Changes in Physiological and Agronomical Parameters of Barley (Hordeum vulgare) Exposed to Cerium and Titanium Dioxide Nanoparticles

The aims of our experiment were to evaluate the uptake and translocation of cerium and titanium oxide nanoparticles and to verify their effects on the growth cycle of barley (Hordeum vulgare L.). Barley plants were grown to physiological maturity in soil enriched with either 0, 500 or 1000 mg center dot kg(-1) cerium oxide nanoparticles (nCeO(2)) or titanium oxide nanoparticles (nTiO(2)) and their combination. The growth cycle of nCeO(2) and nTiO(2) treated plants was about 10 days longer than the controls. In nCeO(2) treated plants the number of tillers, leaf area and the number of spikes per plant were reduced respectively by 35.5%, 28.3% and 30% (p <= 0.05). nTiO(2) stimulated plant growth and compensated for the adverse effects of nCeO(2). Concentrations of Ce and Ti in aboveground plant fractions were minute. The fate of nanomaterials within the plant tissues was different. Crystalline nTiO(2) aggregates were detected within the leaf tissues of barley, whereas nCeO(2) was not present in the form of nanoclusters.