Grant: Discovery Grants Program - Individual

Eriophorum vaginatum is a tussock forming sedge that grows abundantly in the northern wetlands. We localized extensive populations of this species growing in metal-contaminated sites near Sudbury, ON. One hundred years resource exploitation and mineral processing in this part of Canada has given a rise to metal and acid contaminated soils, sadly creating an ideal study site in search of innate plant species resistant to heavy metals. E. vaginatum is an excellent model to study metal tolerance in a search for native bioremediator of polluted wetland sites in the northern hemisphere. It is hardy, deep rooted perennial and forms long lasting, dense tussocks and it is early succession dominant species. My earlier work described structure of the corm, where atypical vascular ring aided to xylem and phloem transport. The origin of vascular ring is unknown. Using LCSM and serial sectioning, I propose to determine whether vascular ring is formed by activity of apical meristem or it is formed by diverging leaf traces at the nodes. I also identified sclerenchyma cells associated with vascular bundles, only present in E. vaginatum. A systematic study will reveal sclerid development and lignification to determine whether those add to the metal tolerance. Using ICP-MS, I will determine the concentration of metals in the all parts of the E. vaginatum to demonstrate whether E. vaginatum is a hyperaccumulator or biostabilizator of the pollutants from Sudbury region. Furthermore, with the aid of LCSM and Al-specific fluorescent probes, I will localize accumulated Al at the tissue, cellular and subcellular levels to reveal the mechanism of Al tolerance in this species. Pattern of branching and roots formation will be determined by CT scans. These 3- D imaged might reveal that roots are sheltered from external pollutants by microsite of the tussock, which could contribute to E. vaginatum resistance to contaminants. Lastly, microarray analysis of genes involved in metal tolerance in E. vaginatum will be performed to identify genes that are up- and down-regulated in response to metals. This research may lead to the use of E. vaginatum in biostabilization and revegetation of the contaminated wetlands in the northern hemisphere.