1. Compartmentalization and ultrastructural alterations induced by chromium in aquatic macrophytes.
- Author
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Mangabeira PA, Ferreira AS, de Almeida AA, Fernandes VF, Lucena E, Souza VL, dos Santos Júnior AJ, Oliveira AH, Grenier-Loustalot MF, Barbier F, and Silva DC
- Subjects
- Chromium analysis, Microscopy, Electron, Transmission, Plant Leaves chemistry, Plant Leaves ultrastructure, Plant Roots chemistry, Plant Roots ultrastructure, Plant Stems chemistry, Plant Stems ultrastructure, Rivers, Spectrometry, Mass, Secondary Ion, Water Pollutants, Chemical analysis, Amaranthaceae anatomy & histology, Amaranthaceae drug effects, Chromium pharmacology, Eichhornia anatomy & histology, Eichhornia drug effects, Polygonum anatomy & histology, Polygonum drug effects, Rubiaceae anatomy & histology, Rubiaceae drug effects, Water Pollutants, Chemical pharmacology
- Abstract
The aim of the present study was to identify the sites of accumulation of Cr in the species of macrophytes that are abundant in the Cachoeira river, namely, Alternanthera philoxeroides, Borreria scabiosoides, Polygonum ferrugineum and Eichhornia crassipes. Plants were grown in nutritive solution supplemented with 0.25 and 50 mg l(-1) of CrCl(3)·6H(2)O. Samples of plant tissues were digested with HNO(3)/HCl in a closed-vessel microwave system and the concentrations of Cr determined using inductively-coupled plasma mass spectrometry (ICP-MS). The ultrastructure of root, stem and leaf tissue was examined using transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS) in order to determine the sites of accumulation of Cr and to detect possible alterations in cell organelles induced by the presence of the metal. Chromium accumulated principally in the roots of the four macrophytes (8.6-30 mg kg(-1) dw), with much lower concentrations present in the stems and leaves (3.8-8.6 and 0.01-9.0 mg kg(-1) dw, respectively). Within root tissue, Cr was present mainly in the vacuoles of parenchyma cells and cell walls of xylem and parenchyma. Alterations in the shape of the chloroplasts and nuclei were detected in A. philoxeroides and B. scabiosoides, suggesting a possible application of these aquatic plants as biomarkers from Cr contamination.
- Published
- 2011
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