Interaction between engineered nanoparticles and vascular plant: Ocimum basilicum as plant model

Nanotechnology is the new frontier of research and nowadays many nanoproducts are utilized in common goods, in medical supplies and in agricultural products. However, little is known about the impact of these new materials on humans and environment. Several studies assert that the soil could be the environmental compartment designed to be the major recipient of engineered nanoparticles (NPs). To investigate the impact of commercially relevant NPs on soil-plant continuum we compared the effect of Ag, CeO2, Co, Fe3O4, Ni, SnO2, TiO2 NPs on Ocimum basilicum. Basil is a culinary herb normally used fresh in Mediterranean cuisine and could constitute one of the means to accumulate NPs through the food chain. The seedlings were spiked once per week with 50mL of NP solutions at 100mg metal L-1 concentration, to simulate a chronic dose. For the control test only water was supplied. At the end of the experiment (28 days) the following analysis were performed in plant and soil: biomass production, total elements concentrations, plant pigments concentrations, lipid peroxidation, pH, metals availability, total metals concentrations. Results showed that Ag NPs treatment reduced significantly root and leaf dry matter of basil plant with respect to the control. The larger amount of metal-NPs was accumulated in basil roots and the concentration in leaves was significantly higher compared to the control for Ag, CeO2, Co and Ni. Notably, also in the relative short exposure there was an accumulation of Ca in roots, suggesting that the metabolic alteration in plants could be aimed at counteracting the membrane damage generated directly or indirectly by NPs. The physiological parameters did not show significant differences; probably tissues involved in the photosynthesis are not damaged by NPs. Nevertheless, further studies are required to evaluate the impact of these NPs over several generation and their fate in food chain.