Využití autotrofních organismů k hodnocení znečištění nanočásticemi

Abstract

This dissertation presents a pilot study focused on the possibility of using higher plants to evaluate the effects of particles and nanoparticles on the environment. Corn salad (Valerianella locusta) was chosen for the experimental work. Dry and wet deposition was performed using two types of titanium dioxide particles, which differed in particle size distribution. Two different types of silver nanoparticles were used as representatives of nanoparticles, differing in size, method of preparation, and intended use. The experiments monitored the influence of the following factors: type of particles/nanoparticles applied, method of deposition (dry deposition, wet deposition by watering or spraying on leaves), concentration of particles/nanoparticles in suspension/solution during wet deposition, frequency of application, and age of plants at the start of deposition. Changes in chlorophyll concentration in the leaves and changes in the chemical composition of the above-ground biomass after the end of the experiment were evaluated. All results were compared with values obtained from control plants that were not affected by any form of deposition. In addition, changes in RNA expression were monitored using differential gene expression in selected experimental variants. Generalized linear models (GLM) were used to evaluate the relationships between individual factors and results, with the time component modeled using a B-spline function. The results showed that the effect of particles and nanoparticles was significantly influenced by the deposition method, particle type, and plant age. The most significant effect on chlorophyll concentration and Ti/Ag concentration in the above-ground part of the plants was shown by dry deposition of TiO₂ particles and wet deposition of silver nanoparticles in the form of spraying on leaves, compared to alternative methods of application of these materials. Changes in the accumulation of essential elements (Ca, Fe, K, Mg, Mn, Na) in biomass were also recorded. The conclusions of the study confirm that the selected model plant species is suitable for studying the effects of particles and nanoparticles on the environment. The study also provides new insights into the biological effects of these materials on higher plants and contributes to a deeper understanding of their potential toxicity and environmental impacts.