Bacteria Mediating Higher Heavy Metal Accumulation in Plants used for Phytoextraction

Abstract

Phytoremediation is an emerging cleanup technology for the restoration of soils and is based on the use of plants. Phytoextraction is the application of higher plants to remove inorganic contaminants, primarily metals, from polluted soil. Willow (Salix caprea L.) is a suitable candidate for phytoremediation applications due to its rapid growth and high biomass production and highly accumulating clones have been identified in a previous project. In addition, a high number of bacterial strains (346) have been isolated from the rhizo- and endosphere of Salix caprea L. growing in heavy metal contaminated sites and characterized. Some studies and results obtained by the project consortium indicate that the plant-associated microflora plays an essential role in the metal accumulating capacity of the plant. Bacteria are known to interact synergistically with roots to enhance the potential for metal uptake by diverse mechanisms such as secreting organic compounds which increase the bio-availability and facilitate root absorption of metals by influencing metal solubility. They may further alter root exudation as well as plant gene expression. Plant growth promoting bacteria with a highly beneficial effect on phytoextraction efficiency have been identified by the project consortium. Within this project isolated strains will be tested for their effect on plant gene expression as well as their colonization efficiency. Compounds responsible for mobilizing effects will be identified. Subsequently, selected strains will be thoroughly tested in plant experiments regarding their application potential. A detailed population analysis of bacteria associated with highly and poorly accumulating Salix caprea L. clones will reveal, which bacterial groups correlate with a good accumulation potential. The results of this project will identify promising inoculant strains and will as well provide the basis for the further development of improved phytoextraction technologies.

Project coordinator: Dr. Angela Sessitsch

Project information

> Contact: Markus Puschenreiter, e-mail: markus.puschenreiter@boku.ac.at, Phone: +43 1 47654 3126

Author: Markus Puschenreiter · last modified: 21.05.2010 09:18:09