Use of micro-PIXE to determine spatial distributions of copper in Brassica carinata plants exposed to CuSO4 or CuEDDS

• Published in: The Science of the total environment Vol. 427-428; pp. 339 - 346
• Main Authors: Cestone, Benedetta, Vogel-Mikuš, Katarina, Quartacci, Mike Frank, Rascio, Nicoletta, Pongrac, Paula, Pelicon, Primož, Vavpetič, Primož, Grlj, Nataša, Jeromel, Luka, Kump, Peter, Nečemer, Marijan, Regvar, Marjana, Navari-Izzo, Flavia
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.06.2012; Elsevier
• Subjects: Applied sciences; Biodegradation, Environmental; Biological and medical sciences; Biotechnology; Brassica - metabolism; Brassica carinata; Copper; Copper - metabolism; Copper Sulfate - metabolism; Decontamination. Miscellaneous; Earth sciences; Earth, ocean, space; EDDS; Engineering and environment geology. Geothermics; Environment and pollution; Ethylenediamines - metabolism; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Inactivation, Metabolic; Industrial applications and implications. Economical aspects; Micro-PIXE; Miscellaneous; Plant Leaves; Plant Roots - metabolism; Plant Shoots - metabolism; Pollution; Pollution, environment geology; Soil and sediments pollution; Soil Pollutants; Spatial distribution; Spectrometry, X-Ray Emission; Succinates - metabolism; Vanadates - metabolism; XRF; Spatial distribution; Micro-PIXE; Brassica carinata; Copper; XRF; EDDS; PIXE; EDTA; Soil pollution; Phytoextraction; Heavy metal; Phytoremediation; Trace element; Decontamination; Cruciferae; Carboxylic acid; Dicotyledones; Aminoacid; Angiospermae; Chelating agent; X ray fluorescence spectrometry; Spermatophyta; Bioremediation
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2012.03.065

A better understanding of the mechanisms that govern copper (Cu) uptake, distribution and tolerance in Brassica carinata plants in the presence of chelators is needed before significant progress in chelate-assisted Cu phytoextraction can be made. The aims of this study were therefore to characterise (S,S)-N,N′-ethylenediamine disuccinic acid (EDDS)-assisted Cu uptake, and to compare the spatial distribution patterns of Cu in the roots and leaves of B. carinata plants. The plants were treated with 30μM or 150μM CuSO4 or CuEDDS in hydroponic solution. Quantitative Cu distribution maps and concentration profiles across root and leaf cross-sections of the desorbed plants were obtained by micro-proton induced X-ray emission. In roots, the 30μM treatments with both CuSO4 and CuEDDS resulted in higher Cu concentrations in epidermal/cortical regions. At 150μM CuSO4, Cu was mainly accumulated in root vascular bundles, whereas with 150μM CuEDDS, Cu was detected in endodermis and the adjacent inner cortical cell layer. Under all treatments, except with a H+-ATP-ase inhibitor, the Cu in leaves was localised mainly in vascular tissues. The incubation of plants with 150μM CuEDDS enhanced metal translocation to shoots, in comparison to the corresponding CuSO4 treatment. Inhibition of H+-ATPase activity resulted in reduced Cu accumulation in 30μM CuEDDS-treated roots and 150μM CuEDDS-treated leaves, and induced changes in Cu distribution in the leaves. This indicates that active mechanisms are involved in retaining Cu in the leaf vascular tissues, which prevent its transport to photosynthetically active tissues. The physiological significance of EDDS-assisted Cu uptake is discussed. ► We localised Cu in Brassica carinata treated with CuSO4 or CuEDDS by micro-PIXE. ► EDDS-assisted Cu uptake and transport resulted in preserved root endodermis. ► EDDS enhanced Cu transport from roots to shoots. ► Cu sequestration within leaf veins prevented its mobilisation into the mesophyll. ► EDDS presence conferred tolerance of B. carinata to Cu.