Phytotoxic effects of silver nanoparticles in tobacco plants

Abstract

The small size of nanoparticles (NPs), with dimensions between 1 and 100 nm, results in unique chemical and physical characteristics, which is why they are implemented in various consumer products. Therefore, an important concern is the potential detrimental impact of NPs on the environment. As plants are a vital part of ecosystem, investigation of the phytotoxic effects of NPs is particularly interesting. This study investigated the potential phytotoxicity of silver nanoparticles (AgNPs) on tobacco (Nicotiana tabacum) plants and compared it with the effects of the same AgNO concentrations. Accumulation of silver in roots and leaves was equally efficient after both AgNP and AgNO treatment, with predominant Ag levels found in the roots. Exposure to AgNPs did not result in elevated values of oxidative stress parameters either in roots or in leaves, while AgNO induced oxidative stress in both plant tissues. In the presence of both AgNPs and AgNO, root meristem cells became highly vacuolated, which indicates that vacuoles might be the primary storage target for accumulated Ag. Direct AgNP uptake by root cells was confirmed. Leaf ultrastructural studies revealed changes mainly in the size of chloroplasts of AgNP-treated and AgNO-treated plants. All of these findings indicate that nano form of silver is less toxic to tobacco plants than silver ions.

Biochemical changes in sunflower plant exposed to silver nanoparticles / silver ions

“…Exposure of the aquatic plant Spirodela polyrhiza to 5 mg L -1 AgNPs in 10% Hoagland solution resulted in a significant increase in LPO compared to the control [62]. MDA was also significantly increased in leaves of the tobacco plant exposed to 500 µM AgNPs and to 100 µM Ag + [45]. Thus, the changes in MDA observed in the leaves when the tobacco plant is exposed to AgNPs/Ag + are similar to the ones observed in our study with sunflower leaves.…”

“…(30-nm in my study, and from 9 to 10 nm in [44]). Exposure of tobacco plants to 25-, 50-, 75-, 100-or 500-µM doses of AgNPs and Ag + in milli Q water in an Erlenmeyer flask resulted in toxicity by Ag + > AgNPs [45], which is consistent with our observations in sunflowers grown in TSL soil, except for CAT activity which declined on ex- --------------------------------------------------…”

The Effects of Copper and Silver Nanoparticles on Container-Grown Scots Pine (Pinus sylvestris L.) and Pedunculate Oak (Quercus robur L.) Seedlings

“…Our work thus shows that, in woody plants, the cellular organelles most prone to the action of NPs are indeed chloroplasts. Changes of a similar nature have been observed in herbaceous plants as a result of the action of different kinds of NP [7,25,[27][28][29]. Some of the observed changes do not represent a specific reaction to the action of NPs on the part of plants.…”

“…While changes in the ultrastructure of leaves reflecting the application of NPs have already been documented in quite a large number of studies [7,25,[27][28][29], work involving the ultrastructure of stems and roots has been rare. AgNPs taken in via cells of tobacco-plant roots were most often accumulated in vacuoles.…”

The study of toxicity effects of biosynthesized silver nanoparticles using Veronica officinalis extract

“…Silver nanoparticles are applied in numerous products, such as food packaging, cosmetics or medical devices (Saqib and Rahim 2016). The growing production and exploitation of metal nanoparticles raise concerns about their release to the atmosphere, as such release may have a negative impact on the environment, and thus also on human health (Cvjetko et al 2018). The current world literature shows that plants can absorb metal nanoparticles, which leads to their accumulation in the food chain.…”