Effects of nano-TiO2 and vancomycin on seed germination.

Plant nanoecotoxicology is an emerging area of research. The understanding of interaction mechanisms among nanoparticles (NPs), pharmaceutically active compounds (PhACs) and biological systems is still lacking. Seed germination and seedling growth can be either inhibited or enhanced by NPs, whereas the effects of PhACs are primarily dependent on their chemical characteristics and on the biological system. Therefore, the release of NPs and PhACs into the environment and the agricultural reuse of contaminated sludge from wastewater treatment plants is a critical issue. For this reason, the potential bioaccumulation and transfer of these pollutants through the food chains must be investigated. The present study aimed at assessing the phytotoxic effects of nano-TiO2 (0-5000 mg/L) and vancomycin (0-22 mg/L), both alone and as a mixture, on seed germination of four different crops (Lycopersicon esculentum cv. Crovarese, Lycopersicon esculentum cv. San Marzano, Eruca sativa, Diplotaxis tenuifolia). Root and shoot emergence and final length, root elongation rate and total biomass were employed as descriptors of seed germination. Nano-TiO2 did not affect crops, neither alone, nor in mixture. conversely, vancomycin inhibited seed germination of L. esculentum and D. tenuifolia only at low concentrations, whereas germination of E. sativa. was enhanced by vancomycin.