Unravelling the ‘omics’ of plant-fungal mineral weathering under a changing CO2 regime

Supervisors: Professor David  Beerling, Professor Jonathan Leake, Professor Julie Scholes and Dr Steve Rolfe

 Biological weathering of minerals by tree roots and their mycorrhizal fungal partners drives the release of calcium and magnesium ions from soils and ultimately their export into the oceans leading to CO2 sequestration via carbonate sedimentation on the sea-floor. This long-term CO2 sequestration in marine sediments is a major pathway by which plants and fungi regulate global climate over millions of years. However, genomic control of the physiological processes of the fungi, and responses of gene expression patterns to changes in atmospheric CO2 experienced by host trees, are not understood. The current PhD project addresses this major research area by exploiting our recent discovery of key molecular mechanisms of fungal weathering and combines it with our expertise in ectomycorrhizal fungal genomics. The project will involve axenic culturing of pine and birch seedlings in partnership with the ectomycorrhizal fungus Paxillus involutus for which there are extensive genomic resources. These will allow us to determine changes in expression of key functional genes controlling fungal exudation of protons and organic chelators involved in mineral weathering, and genes involved in selective ion uptake by the fungus during weathering. These genomic approaches will be linked to proteomic and the metabolomic responses of the fungus as it contacts target minerals of interest under a range of CO2 treatments.
The project offers outstanding opportunities for the student to gain research experience in a range of metabolomic and functional genomic techniques (e.g., transcriptomics, qT-PCR and bioinformatics) together with a broad appreciation of past global change. It will be the first of its kind to establish molecular-scale controls on major biogeochemical processes that exert global-scale effects on CO2 and climate.
Key Words: biological weathering, ectomycorrhiza, genes, carbon dioxide, past global change

Applications should be made via the university admissions system at http://www.sheffield.ac.uk/postgraduate/research/apply
Applications from UK or European who have or expect to gain at least an Upper Second Class degree  should be made by 30 June 2013.