Abstract
Rhizobium bacteria interact with leguminous plants to form symbiotic nitrogen-fixing root nodules. Rhizobia present a mosaic of surface polysaccharides, each of which specifically involved in plant root colonisation, attachment and infection. This review describes the situation for R. leguminosarum biovar viciae, a symbiote of pea and vetch, for which seven surface polysaccharides have now been characterized. Special attention is given to interactions with specific legume lectins at the root surface, in relation to host-plant-specificity of the root nodule symbiosis.
