FIGURE 3.
A scar- and marker-less in-frame deletion of pvdN in P. fluorescens A506 does not abolish formation of fluorescent pyoverdines. A, scheme for the scar- and marker-less in-frame gene deletion in P. fluorescens A506 (see “Results” for details). LF, left fragment; RF, right fragment; left fragment and right fragment are derived from the upstream or downstream sequences of the region to be deleted. B–E, droplet assays of 1) P. fluorescens A506 ΔpvdP, 2) P. fluorescens A506, 3) P. fluorescens A506 ΔpvdN, 4) P. fluorescens A506 ΔpvdN + pME6010-pvdN-strep, and 5) P. fluorescens A506 ΔpvdN + pME6010-pvdNK261A-strep. Strains were incubated either in the absence (B and C) or in the presence of EDDHA (D and E). The plates were imaged (B and D), and fluorescence was detected on a UV table (C and E).