Determinants of phenotypic heterogeneity in the broad host range and symbiotic α-proteobacterium Sinorhizobium sp. NGR234 and its close relatives

Within this project we will analyze the basics of phenotypic heterogeneity in the plant root bacterium Sinorhizobium sp. NGR234 and its close relatives S. fredii USDA257 and S. meliloti 1021 with respect to the heterogeneous expression of identified autoinducer synthases and quorum quenching proteins. Therefore, various reporter fusions will be investigated in defined cultures as well as in plant rhizospheres. Lastly, we will evaluate if phenotypic heterogeneity is of importance for the ‘broad host’ phenomenon and for plant infection and root nodule formation.