title: Study of the spatial distribution of mercury in roots of vetiver grass (Chrysopogon zizanioides) by micro-pixe spectrometry.
abstract: Localization of Hg in root tissues of vetivergrass (Chrysopogon zizanioides) was investigated by micro-Proton Induced X-ray Emission (PIXE) spectrometry to gain a better understanding of Hg uptake and its translocation to the aerial plant parts. Tillers of C. zizanioides were grown in a hydroponic culture for 3 weeks under controlled conditions and then exposed to Hg for 10 days with or without the addition of the chelators (NH(4))(2)S(2)O(3) or KI. These treatments were used to study the effects of these chelators on localization of Hg in the root tissues to allow better understanding of Hg uptake during its assisted-phytoextraction. Qualitative elemental micro-PIXE analysis revealed that Hg was mainly localized in the root epidermis and exodermis, tissues containing suberin in all Hg treatments. Hg at trace levels was localized in the vascular bundle when plants were treated with a mercury solution only. However, higher Hg concentrations were found when the solution also contained (NH(4))(2)S(2)O(3) or KI. This finding is consistent with the observed increase in Hg translocation to the aerial parts of the plants in the case of chemically induced Hg phytoextraction.
authors.forename: Cristina
authors.initials: C
authors.lastname: Lomonte
authors.forename: Yaodong
authors.initials: Y
authors.lastname: Wang
authors.forename: Augustine
authors.initials: A
authors.lastname: Doronila
authors.forename: David
authors.initials: D
authors.lastname: Gregory
authors.forename: Alan J M
authors.initials: AJ
authors.lastname: Baker
authors.forename: Rainer
authors.initials: R
authors.lastname: Siegele
authors.forename: Spas D
authors.initials: SD
authors.lastname: Kolev
mesh_terms: D001673:Biodegradation, Environmental; D001692:Biological Transport; D002614:Chelating Agents; D049930:Chrysopogon / Q000166:cytology / Q000378:metabolism*; D018527:Hydroponics; D008628:Mercury / Q000032:analysis / Q000378:metabolism*; D035261:Plant Components, Aerial / Q000166:cytology / Q000378:metabolism; D018515:Plant Leaves / Q000166:cytology / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000378:metabolism; D058526:Plant Vascular Bundle / Q000166:cytology / Q000378:metabolism; D013052:Spectrometry, X-Ray Emission / Q000379:methods*
chemical_list: D002614:Chelating Agents; D008628:Mercury