Nanosilver phytotoxicity: mechanisms of action and interaction in tobacco cells – NanoPhytoTox

Head: Biljana Balen, Faculty of Science, University of Zagreb

Duration: 1 May 2016-30 Apr 2020

Summary

The small size of nanoparticles (NPs) results in unique chemical and physical characteristics, which is why they are produced in large quantities for implementation in various products. Due to widespread use of silver nanoparticles (AgNPs), the dominating nanomaterial with antibacterial and antifungal properties, there is a concern regarding its potential detrimental impacts on the environment. Although there have been a lot of toxicological studies published on AgNPs, it is still difficult to draw conclusions about their toxicity. AgNPs are prone to (bio)transformation, which modifies their properties and it is not clear whether toxicity results from the nanoparticles or from Ag+ dissociation. Besides being the vital part of healthy ecosystems, plants play a significant role in transport and bioaccumulation of toxic substances in food chains, but toxicological studies of AgNPs conducted on plants are scare and inconclusive. Moreover, there is a lack of information about effects of AgNPs on important cellular processes. Therefore, in this project we aim to reveal and explain the toxicity of a set of diverse AgNPs to plants in order to contribute to the environmental hazard assessment of AgNP. As the model organism we propose tobacco, an economically interesting plant, frequently used in stress research. We will investigate AgNPs with different coatings, used to enhance NP stability, to reveal whether those characteristics are determinants of toxicity. Stability and biotransformation of AgNPs as well as their uptake in the cells will be studied and correlated with AgNPs-induced effects to distinguish between particle and Ag+ toxicity. We will establish the involvement of oxidative stress in the mechanism of toxicity as well as possible proteomic changes. The results will be used to define biomarkers of AgNP-induced phytotoxicity, which could be useful for environmental biomonitoring. Also, results can be applied to estimate the possibility of use and safety of AgNPs.