Table 1. Bacterial strains and plasmids.
| Strain or plasmid (synonym) | Relevant characteristic(s) | Source or reference |
| Agrobacterium tumefaciens | ||
| A. tumefaciens NT1 | NT1 derivative of strain C58, carrying pZLR4; Biosensor usedfor NAHSL detection; GmR | [38] |
| Escherichia coli | ||
| S17-1 | recA pro hsdR RP4-2-Tc::Mu-Km::Tn7 | [49] |
| DH5α | Host for cloning; SupE44 ΔlacU169 (Φ80lacZΔM15) hsdR17recA1 endA1 gyrA96 thi-1 relA1 | Lab collection |
| DH5α(pUC19) (Ec) | Strain DH5α carrying pUC19; ApR | This study |
| DH5α(pUC19-qsdA) (Ec-qsdA) | QsdA-expressing DH5α; ApR | This study |
| Pectobacterium atrosepticum | ||
| CFBP 6276 | Potato soft-rot pathogen; NAHSL producer | [25] |
| 6276(pME6000) (Pa-QS+) | Strain 6276 carrying pME6000, a broad-host-range cloningvector; TcR | [40] |
| 6276(pME6000-aiiA) (Pa-QS–) | Strain 6276 carrying pME6000 containing the aiiA genefrom Bacillus sp. A24 under the constitutive Plac promoter; TcR | [40] |
| Rhodococcus erythropolis | ||
| R138 (BCA) | NAHSL-degrading isolate obtained from hydroponic cultureof potato plants | [50] |
| R138(pEPR1-qsdA::gfp) (BCA-qsdA::gfp) | R138 transformed with pEPR1 qsdA-gfp | This study |
| R138 ΔqsdA (BCA-ΔqsdA) | R138 with a 813 bp fragment deleted from the qsdA gene | This study |
| Plasmids | ||
| pZLR4 | traG::lacZ/traR reporter system | [38] |
| pME6000 | Broad-host-range cloning vector, TcR | [51] |
| pME6000-aiiA (pME6863) | pME6000 carrying the aiiA gene from Bacillus sp. A24 underthe constitutive Plac promoter | [52] |
| pAKE604 | Conjugative suicide vector for qsdA gene deletion; KmR | [26] |
| pAKE604 ΔqsdA | pAKE604 containing the qsdA upstream and downstreamregions; KmR | This study |
| pEPR1 | Shuttle promoter-probe vector carrying the promoterlessgfpuv reporter gene; KmR | [28] |
| pEPR1-qsdA::gfp | pEPR1 with a qsdA::gfp uv transcriptional fusion; KmR | This study |
| pUC19 | Cloning vector for E. coli; ApR | Lab. collection |
| pUC19-qsdA | pUC19 with a 1376 bp PCR fragment containing the qsdAgene; ApR | This study |
KmR, ApR, GmR and TcR indicate resistance to kanamycin, ampicillin, gentamicin and tetracycline, respectively. NAHSL, N-acyl homoserine lactone; CFBP, Collection Française de Bactéries associées aux Plantes, Institut National de la Recherche Agronomique (INRA), Angers, France.