Table 1.
Bacterial strains, plasmids, and primers used in this study
| Strain, plasmid, or primer | Genotype, phenotype, or sequence (5′–3′)a | Source or reference |
|---|---|---|
| Strains | ||
| P. aeruginosa strain | ||
| PAO1 | Wild type | 17 |
| Pseudomonas sp. strains | ||
| DF41 | Rifr; wild type (canola root tip isolate) | 32 |
| DF41 relA | DF41 with a Gmr cassette inserted into the relA gene | This study |
| DF41 relA spoT | DF41 relA mutant with a Tetr cassette inserted into the spoT gene | This study |
| DF41-469 | Rifr; gacS::Tn5-1063 genomic insertion | 2 |
| DF41-1278 | Rifr; lp::Tn5-1063 genomic insertion | 2 |
| 1278 relA | DF41-1278 with Gmr cassette inserted into the relA gene | This study |
| 1278 relA spoT | 1278 relA mutant with Tetr cassette inserted into the spoT gene | This study |
| E. coli strain | ||
| DH5α | supE44 ΔlacU169 φ80dlacZΔM15 hsdR17 recA1 endA1 gyrA96 thi-1 relA1 | Gibco |
| Plasmids | ||
| pLP170 | Promoterless lacZ transcriptional fusion | 26 |
| pRPOS-lacZ | rpoS promoter in pLP170 | This study |
| pSW205 | Promoterless lacZ translational fusion | 9 |
| pSWrelA | relA promoter and first 21 codons of the open reading frame cloned into pSW205 | This study |
| pCR2.1 | TA cloning vector Ampr | Invitrogen |
| pCRrelA-41 | relA in pCR2.1 | This study |
| pCRspoT | spoT in pCR2.1 | This study |
| pEX18Ap | Suicide plasmid Ampr | 16 |
| pEXrelA | relA in pEX18Ap | This study |
| pEXrelA-800 | pEX18Ap with an 800-bp deletion in relA | This study |
| pEXrelA-Gent | pEXrelA-800 Gmr | This study |
| pEXspoT | spoT in pEX18Ap | This study |
| pEXspoT-Tet | pEXspoT with Tetr cassette inserted into spoT | This study |
| pUCP22 | Broad-host-range vector Ampr Gmr | 36 |
| pUCPrelA | relA in pUCP22 | This study |
| pUCPspoT | spoT in pUCP22 | This study |
| pUCP22-rpoS | rpoS in pUCP22 | 26 |
| pUCP23-gacS | gacS in pUCP23 | 26 |
| pME-rpoS | rpoS in pME6010 | This study |
| pME6010 | pVS1-p15A shuttle cloning vector; Tetr | 14 |
| pME3219 | pME6010 containing an hcnA-lacZ translational fusion | 22 |
| pRK600 | Contains tra genes for mobilization; Chlr | 8 |
| pUCGm | Source of Gmr cassette | 33 |
| pFTC1 | Source of Tetr cassette | 5 |
| Primers | ||
| relA-FOR | ACCGTGGTAAAGGGTAGGCAAG | This study |
| relA-REV | GGGAAATCCCCCTGCTCTATG | This study |
| relAtransl-FRW | GGAATTCCCGCTTTTTTCAAGCCGAT | This study |
| relAtransl-REV | GAGGATCTCGGCGATCTCCA | This study |
| spoT-FOR | GCGTCACCGTTGAAGACTG | This study |
| spoT-REV | TTACTCGAGGACGACGATGG | This study |
| rpoSF | TACGTCAGTGCTTACGGCCA | This study |
| rsmZR | TATGACCCGCCCACATTTTT | This study |
| P170fecorpoS | TGTGAATTCGGGAGGGACA | This study |
| P170rxbarpoS | AGTCTAGAATCACCACTTCCCATTGCTT | This study |
a
Amp, ampicillin; Chl, chloramphenicol; Gm, gentamicin; Rif, rifampin; Tet, tetracycline.