Table 1.

Bacterial strains and plasmids used in this study

Strain or plasmidRelevant characteristicsReference or source
Strains
S. melilotiRm5000SU47rif-5 13
A. tumefaciens
  GMI9023C58 cured of pAtC58 and pTiC58 44
  At125GMI9023 pRmeSU47b 14
  At128GMI9023 pRMeSU47a 14
E. coli
  DH5αF supE44 ΔlacU169(φ180dlacZΔM15)hsdR17(rK mK +) recA1 endA1 gyrA96 thi-1 relA1 Laboratory stock
  QC1799FΔ(argF-lac)U169 rpsL ΔsodA3Φ(sodB-kan)Δ2 57
  QC2375QC1799 ΔrecA306 srl::Tn10 57
  QC2461MG1655 ΔlacIZ This laboratory
Plasmids
 pUC18Cloning vector, ColE1 origin, Apr Laboratory stock
 pRS41pUC18, 2.7-kbS. meliloti library plasmid with sodA gene, Apr This study
 pRS41.1pRS41 with 1.2 kbEcoRI-EcoRI deletion,sodA + Apr This study
 pJF119EHExpression vector with tac promoter, Apr 16
 pRS51pJF119EH withsodA structural gene on a 760-bpEcoRI-HindIII fragment under tacpromoter control, Apr Tcr This study
 pDT1-19pBR322 with E. coli sodA structural gene under tac promoter control 57
 pKOK5pSUP202 derivative, source of lacZ-Km cassette, Apr Kmr 28
 pJQ200skCloning vector, p15A origin,sacB + Gmr 42
 pRS58pJQ200sk with sodA-lacZ-Km transcriptional fusion, Gmr Kmr This study