engleski

Protective effects of cysteine against silver nanoparticles-induced phytotoxicity

Nanoparticles (NPs), with three dimensions between 1 and 100 nm, exhibit new characteristics compared to the same material without nanoscale features and are applied in the wide range of commercial products. Therefore, they are likely to be released into the environment and affect plants. Since plants play a significant role in accumulation and biodistribution of environmentally released substances, they can serve as a route for NPs transportation and bioaccumulation into food chains. In this study we have examined the effects of silver nanoparticles (AgNPs) with two different coatings [polyvinylpyrrolidone (AgNP-PVP) and cetyltrimethylammonium bromide (AgNP-CTAB)] on photosynthesis and oxidative stress parameters of tobacco (Nicotiana tabacum) seedlings. Three AgNP- PVP and AgNP-CTAB concentrations (25, 50 and 100 μM) were tested. In order to estimate the contribution of dissolved Ag+ to the effects of AgNP, 125, 250 and 500 μM cysteine, a strong silver ligand, has been applied to complex Ag+. Results of chlorophyll fluorescence showed that photosynthesis efficiency was decreased in AgNP treatments, indicating a negative impact on photosynthetic apparatus, which was, however, alleviated when cysteine was added to the medium. Moreover, malondialdehyde and protein carbonyl content increased in AgNP-exposed seedlings, while combined treatments with cysteine mitigated oxidative stress. Obtained results suggest that AgNP toxicity at least partially originates from dissociated Ag+.

Nicotiana tabacum ; nanoparticles , ; chlorophyll fluorescence ; photosynthesis ; oxidative stress

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