Figure 3
From: CRISPR interference to interrogate genes that control biofilm formation in Pseudomonas fluorescens
Swarming motility phenotypes in P. fluorescens SBW25. Swarming phenotypes were compared for CRISPRi-mediated silencing and deletion mutants. CRISPRi silencing used gRNANT targeting the start of the ORF (denoted g-gene name). Target genes include gacS (PFLU3777) encoding the kinase sensor protein GacS and several genes encoding c-di-GMP binding proteins such as RimA (PFLU0263, PDE), DipA (PFLU0458, PDE), the alginate co-polymerase Alg44 (PFLU0988), GcbA (PFL0621, DGC) and BifA (PFLU4858, PDE) (see also Supplementary Fig. S6). The control corresponds to the pPFL-gRNA plasmid with no guide RNA inserted. Note that SBW25 cells deleted for the same genes also carried the non-active CRISPRi system (i.e., no gRNA expressed) to treat all the strains under identical conditions. (A) Typical swarming morphotypes observed at the surface of soft-agar plates incubated 48 hrs at 25 °C. Plates are circled in purple for CRISPRi silencing (gRNA) and in brown for deletion mutants (Δ). (B) Box plot representing the swarm areas of cells with silenced (gRNA) or deleted (Δ) gene relative to the control strain (n ≥ 4). Statistical significance is indicated (T test, *p <  = 0.05 **p <  = 0.01 ***p <  = 0.001).
