TABLE 2.
Comparison of induction of virB::lacZ in A. tumefaciens strains with different sugars and phenolic compoundsa
| Inducing compounds | β-Galactosidase (U) obtained with A. tumefaciens strain:
|
|||
|---|---|---|---|---|
| C58 (pSM243cd) | A6 (pSM243cd) | C58ΔvirA (pSM402) | C58ΔvirA (pGP159) | |
| HAP | 3.5 ± 0.1 | 4.4 ± 0.6 | 3.4 ± 0.1 | 5.1 ± 0.5 |
| + Glucose | 15 ± 2.7 | 3.6 ± 1.0 | 9.6 ± 0.4 | 106 ± 3 |
| + Arabinose | 59 ± 2.8 | 7.0 ± 0.2 | 44 ± 0.2 | 376 ± 25 |
| p-Coumaric acid | 2.6 ± 0.6 | 11 ± 2.1 | 3.8 ± 0.4 | 4.8 ± 0.2 |
| + Glucose | 5.7 ± 1.6 | 4.7 ± 1.2 | 5.4 ± 0.5 | 11.6 ± 1.0 |
| + Arabinose | 53 ± 13 | 3.5 ± 0.1 | 17.3 ± 2.8 | 164 ± 11 |
| Phenol | 2.8 ± 0.1 | 6.1 ± 0.4 | 5.1 ± 0.3 | 5.4 ± 0.9 |
| + Glucose | 5 ± 0.5 | 3 ± 0.2 | 5.5 ± 0.1 | 12.7 ± 1.4 |
| + Arabinose | 30 ± 1.8 | 2 ± 0.1 | 10.6 ± 0.3 | 94 ± 16 |
a All strains were grown for 20 to 24 h in GIB induction medium containing phenolic compounds with or without monosaccharides at the indicated concentrations. The cultures were then assayed for β-galactosidase activity as described in the text. The data are means ± standard errors of the means for three samples. pSM243cd contains a virB::lacZ fusion. pSM402 contains pTiA6 virA, virG, and a virB::lacZ translational fusion in pVK102, a low-copy-number cosmid (1 to 2 copies/cell) (18a). pGP159 also contains pTiA6 virA, virG, and a virB::lacZ translation fusion in IncP vector pTJS75 (10 to 15 copies/cell) (8). β-Galactosidase activities of cultures lacking phenolic compounds were less than 2 U. HAP was used at 250 μM, while p-coumaric acid and phenol were used at 100 μM. Arabinose and glucose were used at 10 mM.