Professor Phil Poole
Nitrogen fixation, Chemotaxis and motility, Bacteria
Investigating the role of chemotaxis and motility in the legume-rhizobia symbiosis.
I am studying symbiotic nitrogen-fixing bacteria. These rhizobia form symbioses with peas and other legumes, providing the plant with nitrogen. In return, the plant provides carbon and a niche in which the bacteria grow and divide. I am focussing on the chemotaxis (movement towards chemicals) and motility aspects of the symbiosis.
While in the soil, the bacteria have to locate and transport itself to the location of the pea plant. This requires the bacteria to be able to distinguish symbiotic plants from non-symbiotic, a poorly understood process that I am aiming to elucidate. This year, my research has involved the use of microscopy to visualise bacteria swimming and colonising pea roots and marking bacteria with fluorescent proteins for better visualisation. In addition, I have done extensive cloning work in bacteria in order to delete genes particularly important to chemotaxis and motility. This will allow me to determine the importance of each aspect of these pathways in the rhizobium-legume symbiosis. The knowledge drawn from these experiments will hopefully reveal important details in the initial stages of the rhizobium-legume symbiosis that have previously been poorly studied.