Uptake, translocation and ligand of silver in Lactuca sativa exposed to silver nanoparticles of different size, coatings and concentration

• Published in: Journal of hazardous materials 2020-02, Vol.384, p.121201, Article 121201
• Main Authors: Torrent, Laura, Iglesias, Mònica, Marguí, Eva, Hidalgo, Manuela, Verdaguer, Dolors, Llorens, Laura, Kodre, Alojz, Kavčič, Anja, Vogel-Mikuš, Katarina
• Format: Article
• Language: English
• Subjects: Biological Transport; Carotenoids - metabolism; Chlorophyll - metabolism; Inductively coupled plasma optical emission spectrometry; Lactuca - drug effects; Lactuca - metabolism; Lactuca sativa; Ligands; Metal Nanoparticles - chemistry; Metal Nanoparticles - toxicity; Particle Size; Plant Roots - drug effects; Plant Roots - metabolism; Plant Shoots - drug effects; Plant Shoots - metabolism; Silver - chemistry; Silver - toxicity; Silver nanoparticles; Single particle inductively coupled plasma mass spectrometry; Surface Properties; X-ray absorption spectroscopy
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2019.121201

[Display omitted] •Lactuca sativa were exposed to different AgNPs at different concentrations.•Accumulation of AgNPs depends on their size and concentration.•NP characteristics and concentration has an influence on their transport to shoots.•Appearance of Ag-O/Ag-S bonds indicated the dissolution of some NPs in roots.•Transpiration and stomatal conductance were affected after being exposed to AgNPs. The broad use of silver nanoparticles (AgNPs) in daily life products enhances their possibilities to reach the environment. Therefore, it is important to understand the uptake, translocation and biotransformation in plants and the toxicological impacts derived from these biological processes. In this work, Lactuca sativa (lettuce) was exposed during 9 days to different coated (citrate, polyvinylpyrrolidone, polyethylene glycol) and sized (60, 75, 100 nm) AgNPs at different concentrations (1, 3, 5, 7, 10, 15 mg L−1). Total silver measurements in lettuce roots indicated that accumulation of AgNPs is influenced by size and concentration, but not by nanoparticle coating. On the other hand, nanosilver translocation to shoots was more pronounced for neutral charged and large sized NPs at higher NP concentrations. Single particle inductively coupled plasma mass spectrometry analysis, after an enzymatic digestion of lettuce tissues indicated the dissolution of some NPs. Ag K-edge X-ray absorption spectroscopy analysis corroborated the AgNPs dissolution due to the presence of less Ag-Ag bonds and appearance of Ag-O and/or Ag-S bonds in lettuce roots. Toxicological effects on lettuces were observed after exposure to nanosilver, especially for transpiration and stomatal conductance. These findings indicated that AgNPs can enter to edible plants, exerting toxicological effects on them.