Table 5. Effect of GTP or (p)ppGpp levels in toxin induced PI staining and dormancy.
| Conditions of toxin expression | Tf | % PI stained cellsg | CFUs ml−1, h , i |
| xylR-P XylA+Deca | - | 3.4±0.2 (530) | 2.8 108 |
| xylR-P XylAζY83C | No | 1.8±0.2 (800) | 1.8 108 |
| xylR-P XylAζY83C+Deca | No | 5.3±0.4 (478) | 1.8 108 |
| xylR-P XylAζY83C+Xyla | Yes | 17±1.3 (937) | 1.5 103 |
| xylR-P XylAζY83C+Dec+Xylb | Yes | 19±1.6 (1041) | 5.0 103 |
| xylR-P XylA (ΔrelA)+Deca | - | 3.2±0.2 (700) | 3.0 108 |
| xylR-P XylAζY83C (ΔrelA) | No | 4.3±0.5 (800) | 2.7 108 |
| xylR-P XylAζY83C (ΔrelA)+Deca | No | 4.8±0.3 (350) | 2.6 108 |
| xylR-P XylAζY83C (ΔrelA)+Xyla | Yes | 23.9±1.9 (350) | 4.6 105 |
| xylR-P XylAζY83C (ΔrelA)+Dec+Xylb | Yes | 22.7±2.1 (450) | 3.0 105 |
xylR-P XylA or xylR-P XylA ΔrelA or xylR-P XylAζY83C or xylR-P XylAζY83C ΔrelA were grown in MMS7. At ∼5×107 cells/ml−1 0.5% Xyla (to induce ζY83C expression) or 0.5 mg ml−1 Deca (to reduce GTP synthesis) or bothb, Xyl and Dec, were added and the culture was incubated for 120 min.
f
The presence of ζY83C toxin is indicated by yes or no.
g
Number of cells analyzed are shown in parentheses.
h
Due to poor growth of the ΔrelA strains CFUs were measured after two days of incubation.
i
The CFUs were measured after 120 min of toxin induction by plating appropriate dilutions on LB plates. The results are the average of at least three independent experiments and are within a 10% standard error.