Table 1.
Bacterial strains and plasmids
| Strain or plasmid | Relevant characteristicsa | Source or reference |
|---|---|---|
| E. coli strains | ||
| TOP10 | F−mcrAΔ(mrr hsdRMS mcrBC) Φ80lacZΔM15 ΔlacX74 recA1 araΔ139Δ(ara-leu)7697 galU galK rpsL (Smr) endA1 nupG | Invitrogen |
| S17-1 | RP4 tra region, mobilizer strain recA derivative of MM294A with RP4-2 (Tc::Mu, Km::Tn7) integrated into the chromosome | 33 |
| DH5α | endA1 hsdR17 supE44 thi-1 recA1 gyrA96 relA1 Δ(argF-lacZYA) ΔlacU169 Φ80lacZ ΔM15 | Invitrogen |
| R. leguminosarum strains | ||
| VF39 | Biovar viciae, Smr | 29 |
| DF20 | VF39SM, chvGΩKm mutant, unable to grow on complex media, Smr Nmr | 10 |
| DF20pDF38 | VF39SM, chvGΩKm mutant complemented in trans with a functional copy of chvG cloned downstream of the constitutive trp promoter in the broad-host-range plasmid, pDG71, Smr Nmr Tcr | 10 |
| DF20pEV91 | VF39SM, chvGΩKm mutant, complemented in trans with a functional copy of ropB cloned downstream of the constitutive trp promoter in the broad-host-range plasmid, pDG71, Smr Nmr Tcr | This study |
| Plasmids | ||
| pCR2.1 Topo | TOPO TA cloning vector, 4.0 kb, Kmr Apr | Invitrogen |
| pFUS1par | Broad-host-range vector with promoterless gusA for transcriptional fusions, par stabilized, Tcr | 46 |
| pDG71 | Broad-host-range derivative of pHC41, constitutively expressed tryptophan promoter and gfp(mut3), Tcr | 11 |
| pNdvB | pFUS1par, ndvB::gusA, Tcr | 39 |
| pDF38 | Broad-host-range vector pDG71 containing a functional copy of chvG downstream of tryptophan promoter, Tcr | 10 |
| pEV91 | Broad-host-range vector pDG71 containing a functional copy of ropB downstream of tryptophan promoter, Tcr | 40 |
| pEV109 | pFus1par with pssA::gusA transcriptional fusion, Tcr | This study |
| pEV117 | pFus1par with phbC::gusA transcriptional fusion, Tcr | This study |
| pEV118 | pFus1par with phaZ::gusA transcriptional fusion, Tcr | This study |
a
Ap, ampicillin; Km, kanamycin; Nm, neomycin, Sm, streptomycin; Tc, tetracycline.