Ramsay lab

Elena Colombi 

Elena completed her Bsc and Msc at the University of Florence and spent six months at the University of Reading. Her research in Paul Rainey's lab at Massey University was centred around the kiwifruit pathogen Pseudomonas syringae pv. actinidiae. During her PhD, she studied the evolution of this pathogen through the acquisition of mobile DNA elements, with particular interest in defining and characterising a novel family of these elements present in plant associated Pseudomonas. Her interest in horizontal gene transfer has brought her to the Ramsay Lab, where she now studies the diversity, structure and evolution of mobile DNA elements in Mesorhizobia.

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Elena's ARC-funded Postdoctoral research “Harnessing horizontal gene transfer for sustainable agriculture” is in collaboration with the Centre of Rhizobium Studies GRDC-funded project "Increasing the effectiveness of nitrogen fixation in pulses through improved rhizobial strains in the GRDC western region". Mesorhizobium species can form a nitrogen-fixing symbiosis with legumes such as chickpea and biserrula. Non-native Australian legumes often lack the right symbiotic partner in Australian soils, thus farmers use foreign Mesorhizobium inocula for the cultivation of chickpea and biserrula. Since these inocula are isolated from overseas, they are not adapted to Australian soils and die over time. Genes coding for symbiosis are encoded on horizontally transmissible elements called ICEs that transfer from the foreign inocula to native mesorhizobia, producing new hybrid strains, often with inferior N-fixation capabilities. This collaboration aims to describe the ecology of the WA native mesorhizobia population and understand if all the Mesorhizobium spp. are able to acquire symbiosis ICEs and become symbionts of introduced legumes. We also want to understand to what extent these evolved symbionts can fix nitrogen in root nodules and what the molecular bases is for poor N-fixing symbionts.