THE MOLECULAR BASIS OF HOST SPECIFICITY IN THE RHIZOBIUM LEGUMINOSARUM-PLANT INTERACTION

Rhizobia, bacterial symbionts of leguminous plants, produce lipo-chitin oligosaccharide (LCO) signal molecules after induction of their nodulation(nod)genes by flavonoids secreted by the plant host. These LCOs have various effects on the roots of the host plants. One of these is the dedifferentiation of groups of cells located in the cortex of the root which leads to the formation of a nodule primordium. Host specificity of nodulation is mediated by the LCOs. In this paper we present an overview of the results of our recent studies on LCOs, mainly focusing on the molecular basis of theRhizobium leguminosarum -plant interaction.