FIG 3 .

Enzymatic activity of PruA required for control of attachment. (A) Biofilms grown on PVC coverslips for 48 h were quantified as described in the legend to Fig. 1C. A wild-type strain with no plasmid inserted (-) and the pruA mutant strain with no plasmid inserted (-) are indicated. The error bars show 1 SD. (B) Congo red colony phenotypes of the indicated A. tumefaciens strains. The bacteria were grown for 48 h at 28°C. (C) Unipolar polysaccharide (UPP) production (red) visualized by staining with Alexa Fluor 594-labeled wheat germ agglutinin (afWGA). Exponential-phase planktonic cultures were incubated with afWGA (10 µg/ml) and spotted (1 µl) onto 1% agarose pad. Bacteria were viewed at a magnification of ×100 on a Nikon E800 epifluorescence microscope (excitation, 510 to 560 nm; emission, >610 nm). The images shown are overlays of phase-contrast and fluorescence microscopy images. The images were exposed for 40 and 400 ms for phase-contrast and fluorescence microscopy, respectively. IPTG (400 µM) was added to each culture. Bars, 5 µm.