Fig. 6.

Biofilm formation of the ΔsagS strain is restored by BfiR and correlates with reduced rsmYZ levels. (A) Expression of bfiR, but not bfiS, restores biofilm formation by the ΔsagS strain. Confocal images showing the biofilm architecture of ΔbfiS mutants harboring an empty plasmid or overexpressing bfiS and sagS and the biofilm architecture of ΔsagS mutants overexpressing bfiS and bfiR. (B) rsmAYZ RNA levels in ΔsagS biofilms complemented with or overexpressing sagS or bfiR, relative to the levels in P. aeruginosa PAO1 and PAO1/pJN105 (PAO1±pJN105), as determined by qRT-PCR. (C) The biofilm architecture of the ΔsagS strain is not restored to wild-type levels upon inactivation of rsmYZ, as revealed by confocal microscopy. White bars = 100 μm.