engleski

Effects of three different organo-coated silver nanoparticles in Allium cepa roots

In the last decade, nanoparticles became a subject of intensive scientific research giving rise to the expansion of variety of nano-scale technologies. The production of engineered nanoparticles offering beneficial improvements has led to incorporation of nanoparticles into a wide range of every day products from cosmetics to electronics. Since plants play a significant role in accumulation and biodistribution of many environmentally released substances, they are also very likely to be influenced by nanoparticles. Until today, our understanding of nanoparticle toxicity in plants still remains challenging. Hence, in this study Allium cepa roots were exposed to three different organo-coated silver nanoparticles (AgNPs): citrate-coated (Citrate- AgNP), polyvinylpyrrolidone-coated (PVP-AgNP) and cetyltrimethylammonium bromidecoated (CTAB- AgNP) as well as to ionic form of silver (Ag NO3). Parameters of oxidative stress (lipid peroxidation, carbonyl content) and activity of antioxidant enzymes (peroxidase, catalase, ascorbate peroxidase) were tested at different silver concentrations (25, 50, 75, 100 and 500 μM) after 72h of exposure. The silver in the form of nitrate exhibited very extensive phytotoxicty effects even at lower concentrations, leading to the root cell death at 500 μM. On the other hand, all three types of AgNPs had moderate effects on root growth, with significant inhibition of root length only at the highest concentrations in treatment with CTAB-AgNP. In general, our results confirmed the higher extent of the oxidative stress in response to silver nitrate in comparison to silver nanoparticles, although type of coating of particular nanoparticles seems to be responsible for modulating antioxidative response in root cells.

nanoparticles; silver; coatings; Allium cepa

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