Combining cryo-scanning electron microscopy, ìX-ray fluorescence spectroscopy and X-ray absorption spectroscopy to probe copper speciation in a bamboo
2011
Collin, Blanche | Doelsch, Emmanuel | Meunier, Jean-Dominique | Keller, Catherine | Panfili, Frédéric
Copper uptake, localization and speciation were studied in hydroponically-grown Phyllostachys fastuosa plants at different increasing concentrations of Cu (0.2, 1.5 and 100 ?M). The spatial distribution and speciation of Cu in tissues of the bamboos were investigated using cryo-scanning electron microscopy, coupled with an energy dispersive spectrometer (SEM-EDS), ?X-ray fluorescence spectroscopy (?XRF) and X-ray absorption spectroscopy (XAS). Inhibitory effects of Cu on plant growth were observed only at higher Cu concentration. Copper concentration in roots and shoots increased with increasing Cu concentration in the growth solution. Copper accumulation followed the pattern roots>stems>leaves. Analysis by SEM and ?XRF studies revealed the presence of Cu mainly in the epidermis of the root. A significant amount of Cu seems to be adsorbed and/or precipitated at the surface of the roots i.e. into apoplast material. Cu K Edge X-ray absorption near edge structure (XANES) showed that the Cu speciation depends on the part of the plant: in roots most Cu is divalent, whereas in stems and leaves Cu is monovalant. (Résumé d'auteur)
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