FIG. 6.

Visualization of infection threads elicited by wild-type and lps-212 mutant strains. Plasmid pXLGD4 containing a hemA::lacZ transcriptional fusion was mobilized into strain Rm1021 (wild type) and DKR1 (lps-212) by conjugation. The transconjugants were inoculated onto plants, and the progress of infection was examined at either 7 days or 28 days postinoculation by fixing and staining the plants for β-galactosidase activity as described in Materials and Methods. The arrows point to infection threads.