Foliar exposure of the crop Lactuca sativa to silver nanoparticles: evidence for internalization and changes in Ag speciation

Abstract : The impact of engineered nanomaterials on plants, which act as a major point of entry of contaminants into trophic chains, is little documented. The foliar pathway is even less known than the soil-root pathway. However, significant inputs of nanoparticles (NPs) on plant foliage may be expected due to deposition of atmospheric particles or application of NP-containing pesticides. The uptake of Ag-NPs in the crop species Lactuca sativa after foliar exposure and their possible biotransformation and phytotoxic effects were studied. In addition to chemical analyses and ecotoxicological tests, micro X-ray fluorescence, micro X-ray absorption spectroscopy, time of flight secondary ion mass spectrometry and electron microscopy were used to localize and determine the speciation of Ag at sub-micrometer resolution. Although no sign of phytotoxicity was observed, Ag was effectively trapped on lettuce leaves and a thorough washing did not decrease Ag content significantly. We provide first evidence for the entrapment of Ag-NPs by the cuticle and penetration in the leaf tissue through stomata, for the diffusion of Ag in leaf tissues, and oxidation of Ag-NPs and complexation of Ag+ by thiol-containing molecules. Such type of information is crucial for better assessing the risk associated to Ag-NP containing products.
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Article dans une revue
Journal of Hazardous Materials, Elsevier, 2014, 264, pp.98-106. 〈10.1016/j.jhazmat.2013.10.053〉
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https://hal.archives-ouvertes.fr/hal-00913942
Contributeur : Hervé Vezin <>
Soumis le : mercredi 4 décembre 2013 - 15:43:21
Dernière modification le : mardi 3 juillet 2018 - 11:37:28

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C. Larue, H. Castillo-Michel, S. Sobanska, L. Cécillon, S. Bureau, et al.. Foliar exposure of the crop Lactuca sativa to silver nanoparticles: evidence for internalization and changes in Ag speciation. Journal of Hazardous Materials, Elsevier, 2014, 264, pp.98-106. 〈10.1016/j.jhazmat.2013.10.053〉. 〈hal-00913942〉

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