The Role of the Rhizobium Meliloti Exopolysaccharides EPS I and EPS II in the Infection Process of Alfalfa Nodules

摘要: Rhizobium meliloti is able to produce two different exopolysaccharides, the succinoglucan EPS I and alternative II. R. mutants deficient in production are unable form infection threads. They induce alfalfa nodules which lack bacteroids. Six exo genes were found be involved as well nodule localized on megaplasmid 2. The regulatory gene rexA effects conversion from II production, was identified. proved substitute process. biosynthesis elicit plant defence mechanisms at contact zone between microsymbiont surface of nodule. We suggest that a signal molecule biosynthetic pathway necessary for invading strain recognized symbiont.