FIG. 2.

Response of a tfdK mutant to 2,4-D. (A) Chemotactic swarms formed by wild-type cells, the tfdK mutant, and the tfdK mutant expressing the tfdK gene in trans on swarm plates containing 0.25 mM 2,4-D. (B) Modified capillary assays showing the response of tfdK mutant cells and complemented tfdK mutant cells to 2,4-D. Both strains were grown on 3 mM 2,4-D. Results are shown in photographic form (top) and illustrative form (bottom).