Table 4. Symbiotic expression of various genes in wild-type, ΔnifA1 and ΔnifA2 backgrounds.
| Gene fusion | a ß-galactosidase activity (Miller units) in: | ||
| R7A | JS01 (ΔnifA1) | JS02 (ΔnifA2) | |
| No lacZ fusion | 6.4±1.5 | 5.0±0.7 | 10.0±3.2 |
| nifA genes | |||
| nifA1::lacZ | 297.9±191.2 | ND | 10.6±1.6* |
| nifA2CMD::lacZ | 307.5±96.3 | 293.1±134.2 | ND |
| Genes with NifA/RpoN promoters | |||
| acdS::lacZ | 369.4±167.7 | 547.2±111.9 | 7.5±4.4*+ |
| ccpR::lacZ | 347.7±70.6 | 268.8±73.3 | 7.6±1.8**++ |
| fixACMD::lacZ | 527.8±145.4 | 355.5±74.8 | 7.8±2.4**+ |
| msi036::lacZ | 275.8±39.9 | 76.5±16.6•• | 4.3±1.6*+ |
| msi071::lacZ | 618.4±59.6 | 646.0±157.9 | 6.3±1.2*+ |
| msi158::lacZ | 1281.7±251.8 | 1150.0±211.1 | 5.5±0.9**++ |
| msi260::lacZ | 1339.3±72.5 | 685.9±374.5• | 5.1±2.1**+ |
| msi262CMD::lacZ | 613.2±120.7 | 424.5±139.3 | 7.4±1.3*+ |
| msi276CMD::lacZ | 552.9±108.0 | 301.7±106.8 | 14.2±7.8*+ |
| msi280::lacZ | 371.6±125.7 | 268.9±101.4 | 7.3±1.3*+ |
| msi321::lacZ | 319.8±84.7 | 205.4±63.8 | 11.7±2.1*+ |
| msi332::lacZ | 446.6±71.4 | 273.5±89.9 | 14.6±10.2**+ |
| nifB::lacZ | 684.9±79.7 | 535.7±89.8 | 28.6±23.8**+ |
| nifH::lacZ | 854.8±126.1 | 610.6±86.6 | 9.4±7.2**++ |
| nifS::lacZ | 492.5±144.3 | 413.0±125.7 | 5.9±3.7*+ |
| prxS::lacZ | 204.1±31.1 | 188.8±36.1 | 17.5±12.9*+ |
| prxSCMD::lacZ | 779.8±183.1 | 707.3±174.8 | 6.1±3.4*+ |
| rpoN2::lacZ | 138.7±50.8 | 118.0±25.1 | 19.4±2.0*+ |
| Genes without NifA/RpoN promoters | |||
| aatA::lacZ | 2455.8±110.6 | 2289.8±314.0 | 16.2±7.4**++ |
| asnB::lacZ | 861.7±107.8 | 809.2±174.9 | 22.0±6.7**+ |
| exsA::lacZ | 495.5±223.2 | 524.0±166.5 | 8.7±0.7*+ |
| metE::lacZ | 223.6±91.9 | 171.5±43.4 | 28.1±17.3*+ |
| metK::lacZ | 730.2±227.2 | 467.1±157.2 | 11.1±7.3**+ |
| msi083::lacZ | 280.0±85.4 | 259.6±117.0 | 217.8±98.9 |
| nifQ::lacZ | 200.6±112.2 | 149.3±108.3 | 9.7±10.0*+ |
| pepM::lacZ | 827.1±107.4 | 625.1±168.8 | 7.7±2.0**+ |
| rpoN1::lacZ | 29.7±6.0 | 25.1±7.2 | 24.9±8.5 |
a
ß-galactosidase assays were performed on bacteroid suspensions from nodules harvested 14 days post-inoculation. All activity values are the average of at least two assays ± Standard Deviation. Significant differences in expression observed between R7A and R7AΔnifA1:: Ωkan ** = P<0.005, between R7A and R7AΔnifA2:: Ωkan ++ = P<0.005, between R7AΔnifA2:: Ωkan and R7AΔnifA1:: Ωkan• = P<0.05 (as determined by unpaired t test).