Influence of ZrO2, SiO2, Al2 O3 and TiO2 nanoparticles on maize seed germination under different growth conditions

The focus of this investigation is to evaluate the phytotoxicity of selected metal oxide nanoparticles and microparticles as a function of maize seed germination and root elongation under different growth conditions (Petri plate, cotton and soil). The results of seed germination and root elongation experiments reveal that all the growth conditions show almost similar results. Alumina (Al₂ O₃) and titania (TiO₂) nanoparticles significantly reduce the germination percentage, whereas silica (SiO₂) nanoparticles and microparticles enhance the same. The results of nanoparticles and microparticles of zirconia (ZrO₂) are found to be same as those of controls. Root elongation is enhanced by SiO₂ nanoparticles and microparticles treatment, whereas inhibition is observed with Al₂ O₃ and TiO₂ nanoparticles and microparticles. The X‐ray fluorescence spectrometry data of the treated and control seed samples show that seeds uptake SiO₂ particles to a greater extent followed by TiO₂, Al₂ O₃ and ZrO₂. In addition, the uptake of nanoparticles is found to be greater than that of microparticles. Thus, the tested metal oxides penetrated seeds at the nanoscale as compared with the microscale. This study clarifies phytotoxicity of nanoparticles treated in different growth substrates and highlights the impact of nanoparticles on environment and agricultural systems.Inspec keywords: zirconium compounds, silicon compounds, aluminium compounds, titanium compounds, nanoparticles, nanobiotechnology, botany, toxicologyOther keywords: metal oxide nanoparticles, maize seed germination, phytotoxicity, microparticles, root elongation, growth conditions, Petri plate, cotton, soil, X‐ray fluorescence spectrometry, environment systems, agricultural systems, ZrO₂ , SiO₂ , Al₂ O₃ , TiO₂