Speaker
Description
Silver nanoparticles (AgNPs) and microplastics (MPs) are among the most prevalent emerging contaminants in freshwater ecosystems, yet the role of nanoparticle surface coating in modulating phytotoxicity, particularly under co-exposure conditions, remains poorly understood. To address this, we examined the individual and combined effects of two surface-coated AgNPs, cetyltrimethylammonium bromide (AgCTAB) and polyvinylpyrrolidone (AgPVP), and two MPs, polystyrene (PS) and polymethylmethacrylate (PMMA), on the duckweed Lemna minor over a 7-day exposure period. Control plants were grown without the addition of AgNPs or MPs. Relative growth rate, chlorophyll a fluorescence (JIP-test), pigment content, and expression of photosynthesis-related genes were assessed on days 1, 3, and 7. AgPVP-based combinations with MPs (AgPVP+PS, AgPVP+PMMA) induced the most pronounced physiological stress from the earliest timepoint, while AgCTAB and AgPVP alone caused moderate effects on day 1. By day 3, stress in AgPVP-treated plants intensified, whereas AgCTAB-exposed plants showed signs of recovery towards control values. On day 7, AgPVP+PS remained the most severely affected treatment, while plants treated with AgPVP and AgPVP+PMMA displayed partial recovery, though with persistently reduced growth suggesting lasting physiological consequences. The observed physiological responses in the most affected treatments indicate a decline in photosynthetic efficiency, ultimately resulting in reduced plant growth. These results highlight the coating-dependent nature of AgNP phytotoxicity and suggest that microplastic co-exposure may modulate, but not eliminate, the adverse effects of AgNPs on aquatic macrophytes.
Keywords
duckweed; AgNPs; MPs; co-exposure toxicity
References
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| Corresponding author email | sandra.vitko@biol.pmf.unizg.hr |
|---|---|
| Scientific Session | Cell Biology, Physiology, Metabolisms |
