Research Activities

Localization and speciation of metals at the cellular level

Collaborators

Current summary: The uptake and accumulation of metals in a number of crop species will be investigated using soils collected from contaminated field sites. Because biological influences in the rhizosphere are expected to determine metal bioaccessibility, the influences of both the plant root and soil microbes on the chemical speciation of a number of potentially toxic elements will be investigated using synchrotron x-ray fluorescence (XRF) and x-ray absorption near edge structure (XANES) analyses. These techniques are capable of detecting differences in elemental chemistry over very short distances (a few microns); thus, the soil, the plant root and the root/soil interface can be examined simultaneously in intact samples. The results of this project will be combined with those of other projects within the Soils and Plants Theme to gain a better understanding of the impact of biological activity on the movement of metals from the soil into plants.

Summary Archive: Current | 2007 | 2006

 

Project Metadata

Study/Sampling Design

This study will be based on plants grown under controlled conditions. Some plants will be grown locally in soils provided by the S4 group. Other plants will be provided by members of the S4 group will provide other plants, which will be grown under controlled conditions in soil collected from the field, and which will have varying levels of microbial activity. For the plants grown locally, measurements will include concentrations of a number of metals of interest (Cd, Cu, Ni, Pb and Zn) in roots and shoots; the main goal being to investigate differential accumulation of metals in different species grown in the same soil. Similar measurements are being taken by the S4 group on their plants. For each set of plants, roots and the nearby rhizosphere will be further analyzed using two synchrotron-based techniques: XRF mapping (provides micron scale localization of metals) and XANES (provides information on the solid-phase speciation of metals).

Number of projects providing material for study: 0

Location of Field Site(s)

Collection of soil from a number of field sites will be performed by the S4 group, and subsamples of these will be forwarded to this project. To date two field soils, one from an abandoned agricultural site and the other from an adjacent forested area, have been provided from:

• Valleyfield, Québec, Canada (45° 15’N, 74° 08’W)

Human Studies

Outcome or Process Studied
--- none provided ---

Exposure Medium, and Metals/Substances Quantified
--- none provided ---

Biological Endpoint(s) Monitored
--- none provided ---

Biota Studied

Species
Triticum aestivum cv Perigree, Glycine max cv Hoyt, Daucus carota ssp. sativus, Raphanus sativus, Lactuca sativa

Metals, etc. Quantified
Al, Cd, Cu, Mn, Ni, Pb and Zn

Biological Endpoint(s)
--- none provided ---

Physical Material(s) Studied

Medium/Media
Rhizosphere (thin layer of soil/microbes surrounding each root)

Metals, etc. Quantified
Al, Cd, Cu, Mn, Ni, Pb and Zn

Bibliographic References on-file with Secretariat: No

Data Available: No

Data Archived with MITHE-SN: No