Table 1.
Bacterial strains, plasmids, and primers used in this study.
| Strains, plasmids | Characteristics* | Source |
|---|---|---|
| P. phytofirmans | ||
| LK545 | Wild type PsJN, originally isolated from onion roots. | Frommel et al. (1991) |
| LK583 | Spontaneous rifamycin-resistant mutant of the wild type PsJN (LK545), Rifr | This study |
| LK749 | Wild type PsJN (LK583) containing the empty vector pME6010 | This study |
| LK754 | ΔbceQ mutant of PsJN, made by introducing the deletion construct pEX18TC-ΔbceQ into wild type PsJN (LK583), Rifr | This study |
| LK750 | The ΔbceQ mutant (LK754) containing the empty vector pME6010, Rifr, Tcr | This study |
| LK751 | The ΔbceQ mutant (LK754) containing the complementation construct pME6010-bceQfull, Rifr, Tcr | This study |
| Plasmids | ||
| pEX18Tc | Gene replacement vector with molecular cloning sites from pUC18, sacB+, Tcr | Hoang et al. (1998) |
| pEX18TC-ΔbceQ | pEX18TC containing a deleted gene bceQ. Tcr | This study |
| pME6010 | pACYC177-pVS1 shuttle vector. Tcr | Heeb et al. (2000) |
| pME6010-bceQfull | pME6010 containing bceQ gene cloned from the wild type PsJN. Tcr | This study |
| Oligo DNA primers | DNA sequences (5′-3′) | |
| bceQ-up-F | GTAAAACGACGGCCAGTGTTCACGGAACTGCATCGC | This study |
| bceQ-up-R | GCAGTGAACGCGCAAGATCTACGTTCTTGAGAATGCC | This study |
| bceQ-down-F | GGCATTCTCAAGAACGTAGATCTTGCGCGTTCACTGC | This study |
| bceQ-down-R | CAGGAAACAGCTATGACCTTGGTCAGCTTCGACTGC | This study |
| 18Tc-bceQ-F | GCGATGCAGTTCCGTGAACACTGGCCGTCGTTTTAC | This study |
| 18Tc-bceQ-R | GCAGTCGAAGCTGACCAAGGTCATAGCTGTTTCCTG | This study |
| bceQ-Full-F | TATCCGCTCGAGGAAGCCTTGATGAACGAAGC | This study |
| bceQ-Full-R | TATCCCAAGCTTCATGCGCTTTTCCTCGGA | This study |
*Rifr: rifamycin resistance at 100 mg/ml; Tetr: tetracycline resistance at 20 mg/ml.