FIG. 2.

The hrpX mutant WPP67 formed a pellicle that was distorted and fragile compared to the wild-type pellicles (left column). The pigment visible in some of the pellicles is indigoidine, a blue pigment produced by E. chrysanthemi. WPP67 pellicles were much more fragile than those produced in wild-type cultures; when the pellicles were removed from the culture medium by pouring the culture into petri plates, the WPP67 pellicle, but not the wild-type pellicle, fragmented (right). Expression of hrpXY from a plasmid in WPP67 restored the wild-type phenotype.