MAPPING OF COMPLEMENTATION GROUPS WITHIN A RHIZOBIUM-LEGUMINOSARUM CFN42 CHROMOSOMAL REGION REQUIRED FOR LIPOPOLYSACCHARIDE SYNTHESIS

A major genetic region specifying portions of the carbohydrate structure of Rhizobium leguminosarum CFN42 lipopolysaccharide was analyzed by Tn5 mutagenesis, constructing deletions in cloned DNA, restriction mapping, and complementation analysis. Mutations affecting lipopolysaccharide synthesis were arranged in nine complementation groups spanning 18 kb of DNA. One mutation resulted in O-polysaccharide-containing lipopolysaccharide having a slightly increased mobility in gel electrophoresis. This mutation did not affect the symbiosis with bean plants. The other mutations eliminated the 0-polysaccharide-containing lipopolysaccharide and resulted in strains defective in eliciting bean nodule development. © 1990 Springer-Verlag.