FIGURE 4.

EnvC likely functions in the same pathway as AmiC to help dictate proper polar patterning in A. tumefaciens. (A) DIC images of exponentially growing WT cells containing empty plasmid (PT7med-Empty), ΔamiC containing empty plasmid (PT7med-Empty), or ΔamiC constitutively expressing amiC via the T7 medium promoter [PT7med-AmiC (complementing plasmid)]. Scale bar = 2 μm. (B) Cell viability of WT cells containing empty plasmid (PT7med-Empty), ΔamiC containing empty plasmid (PT7med-Empty), or ΔamiC constitutively expressing amiC via the T7 medium promoter [PT7med-AmiC (complementing plasmid)] is shown by spotting serial dilutions. (C) SDS and salt sensitivity of WT and ΔamiC as described in Figure 3. (D) Cell morphology and microcolony formation are shown for WT, ΔenvC, ΔamiC, and ΔenvCΔamiC at 0 and 5 h. Scale bar = 2 μm. (E) Scatter plot depicting shape mode 2 (curvature) from PCA of cell shape for WT, ΔenvC, ΔamiC, and ΔenvCΔamiC. (F) Quantification of sites of growth initiation following cell division events captured during time-lapse imaging in WT, ΔenvC, ΔamiC, and ΔenvCΔamiC. Daughter cells are defined as cells that inherit the former growth pole. (G) Schematic representation of cell growth polarity inheritance. In WT cells, most mother and daughter cells resume polar elongation at the new pole after completing cell division. However, in the absence of envC, amiC, or both, about 50% of the daughter cells initiate polar growth at the old pole. All data collected for this figure was obtained from cells grown in LB. **P < 0.01; ****P < 0.0001; ns, not signficant.