Engineered nanoparticles effects in soil-plant system: Basil (Ocimum basilicum L.) study case

The aim of this study was to examine the effects of selected metal (Ag, Co, Ni) and metal oxide (CeO2, Fe3O4, SnO2, TiO2) engineered nanoparticles on basil (Ocimum basilicum L.). Seedlings, grown in soil mixture (20% sandy soil, 80% peat), were exposed to nanoparticles once per week, for 4 weeks with solutions at 100 μg mL−1 of nanoparticle component metal, to simulate a chronic exposure to NPs supplied with irrigation. At the end of the experiment (4 weeks), (i) morphological and physiological parameters of basil (e.g. dry weight, gaseous exchange), (ii) nanoparticle component metal taken up by the basil plant (namely, Ag, Ce, Co, Fe, Ni, Sn and Ti) and (iii) the content of nutrients (Ca, Mg, K, Na, P and S) in different basil organs were evaluated. The results indicated that the nanoparticle component metal was mainly accumulated in the basil roots. However, despite the capability of plant to exclude potentially toxic elements, Ag, CeO2, Co and Ni NPs component metal translocate from the root to the shoot reaching the leaves, the edible part of the plant. Notably, also in the relative short exposure there was an accumulation of Ca in roots, suggesting that the modification of metabolic pathway in plants could be aimed at counteracting the membrane damage generated directly or indirectly by nanoparticles.