Understanding soil-to-plant uranium transfer and plant adaptation to radionuclide stress

Environmental contamination by inorganic pollutants is a major challenge to biodiversity and can be a cause of significant organism toxicity. Radionuclides, such as uranium and radium, can be a potential risk to ecosystem health because of radioactivity and chemotoxic effects. Understanding the behaviour, mobility and transfer of radionuclides is critical for the development of management strategies for contaminated sites, and is relevant to applications such as nuclear site remediation and disposal of radioactive waste. It is also unclear whether plants can tolerate radionuclide contaminated environments and if so, whether they have adapted tolerance or have constitutive tolerance. This project will build upon data from recent NERC-funded field surveys of two radionuclide contaminated sites in the UK, which identified dominant plant species that were mediating radionuclide bioaccumulation, and which were all associated with arbuscular mycorrhizal (AM) fungi. The first aim of the project is to investigate the role of specific soil chemistry parameters in influencing uranium and radium uptake into plant roots under controlled conditions. The second aim is to investigate radionuclide tolerance in selected plant species to evaluate adaptation traits, with the hypothesis that tolerant plant species that can grow in radionuclide environments will have evolved adaptation. A key outcome will be improved understanding of the mechanisms underlying the ecological distribution of plant communities in environments contaminated by uranium and radium.