Mutation, Transfer and Location of Symbiotic Genes of Rhizobium leguminosarum biovar phaseoli by Insertion of Tn5-Mob

Effective transfer of indigenous plasmids from R.leguminosarum biovar phaseoli strain RCR3622 was accomplished by transposon Tn5-Mob accompanied by the mobilizing plasmid RP4-4 Transfer of two of the four plasmids of RCR3622 into R.leguminosarum biovar viceae B151 occurred at frequence of 10-3.One of them,Psym3622 (Ca.285kb) was provd to be the symbiotic plasmid.It carries both nod and mel genes spanned in a region about 70 kb.Introduction of nod genes into the nodulation defective strain R.leguminosarum biovar viceae B151 and R.leguminosarum biovar phaseoli JIS400 caused the mutants being able to nodulate Phaseolus vulgaris cv.Jamapa.Nodules formed by B151 transconjugants were non-effective,while those formed by JI8400 transconjugants were fully effective.