About me
My research focuses on understanding the interaction between soil bacteria (rhizobia) and their legume hosts. Rhizobia are unique in their ability to “fix” atmospheric nitrogen into plant-available nitrogen via their symbiotic association with legumes. In agriculture, when legumes are inoculated with elite rhizobial strains in crop rotations, all the nitrogen demands of the legume and subsequent cereal crops can be met, without the need for energy-expensive and CO2-producing industrially synthesised fertilisers. In Australia, nitrogen fixation is worth in excess of $4 billion pa to Australian agriculture and is critical to ensuring food security and maintaining productive farming systems.
However, an unplanned consequence of inoculation is that DNA carrying symbiosis genes (symbiosis islands) may horizontally transfer to native soil bacteria, producing hybrid rhizobia that fix nitrogen poorly on the legume host. These suboptimal hybrid rhizobia compete with the inoculant strain to nodulate the target legume, resulting in reduced benefits to the agricultural system. My research seeks to understand and manage suboptimal nitrogen fixation and competition by unraveling the genetic and metabolic determinants of highly efficient symbiotic interactions, using a combination of cutting edge ‘omics technologies along with traditional microbial and physiological approaches.