Physical map of R. leguminosarum bv. trifolii rosR gene and genomic organization of rosR mutants. Physical and genetic map of pB31 plasmid carrying the rosR gene of Rhizobium leguminosarum bv. trifolii 24.2 (A). (B) The genomic organisation of the Rt2440, Rt2441, and Rt2472 mutants. The heavy line indicates the vector part in the Rt2441 integration mutant. B- Bam HI, H- Hin dIII, S- Sal I, P- Pst I, N- Not I. P1 and P2 are promoter sequences of the rosR gene, and the RosR-box sequence is the target site recognized and bound by RosR protein.