Table 5.
The influence of multiple exoR copies on pssA-lacZ expression in different Rhizobium leguminosarum bv. trifolii 24.2 derivatives under low- and high-ammonium conditions.
| Type of pssA-lacZ fusion | β-galactosidase activity at different NH4Cl concentration (Miller units) * | |||||
|---|---|---|---|---|---|---|
|
| ||||||
| Rt24.2 (wild-type) | Rt24.2pRR1 (exoR) | Rt24.2 (pBBR1MCS-5) | ||||
|
| ||||||
| 0.1 mM | 10 mM | 0.1 mM | 10 mM | 0.1 mM | 10 mM | |
| pPA1 | 4954 ± 389 a | 4804 ± 352 a | 1676 ± 148 c | 2286 ± 186 b | 4869 ± 363 a | 4617 ± 327 a |
| pPA2 | 3773 ± 293 a | 3034 ± 276 b | 2029 ± 178 c | 2318 ± 201 c | 3702 ± 311 a | 2966 ± 284 b |
| pPA3 | 1878 ± 143 a | 1545 ± 131 b | 944 ± 89 c | 1329 ± 124 b | 1821 ± 139 a | 1457 ± 126 b |
| pPA4 | 1540 ± 121 a | 1389 ± 120 a | 827 ± 76 c | 1103 ± 96 b | 1498 ± 132 a | 1317 ± 115 a |
*
Given values (±standard deviation) are averages of three independent experiments with three biological repetitions for each strain and treatment;
a,b,c
indicate statistically significant differences for an individual transcriptional fusion tested in different strains and growth conditions (p value <0.05; ANOVA, Tuckey’s test).