TABLE 1.
Strains and plasmids
| Strain or plasmid | Relevant characteristic(s) | Source or reference |
|---|---|---|
| Strains | ||
| R. meliloti | ||
| Rm1021 | Str | 31 |
| Rm8002 | Str Pho− | 28 |
| SG1001 | agpA::TnphoA; derived from Rm8002 | This laboratory |
| E. coli | ||
| XL1 Blue | Used for cloning and sequencing | Stratagene |
| MM294a | pro28 thi-1 endA1 hsdR17; used to deliver pRK609 to R. meliloti | 28 |
| Plasmids | ||
| pLAFR1 | Tcr; broad-host-range cloning vector | 11 |
| pTE3 | Tcr; pLAFR1 with constitutively active S. typhimurium trp promoter | 7 |
| pRK609 | Nmr Smr; TnphoA | 28 |
| pRmJT5 | Tcr; carries 20-kb region of R. meliloti pSymA including the genes nodD3, syrM, and syrA in pLAFR1 | 44 |
| pMB89 | Derivative of pTE3 with syrA driven by ptrp | 2 |
| pRmE63 | Derivative of pTE3 with nodD3 driven by ptrp | 45 |
| pRmS73 | Derivative of pTE3 with syrM driven by ptrp | 45 |