Pseudomonas syringae Lipopolysaccharide Synthesis Gene wbpL Displays Heterogeneous Expression Within In Vitro and In...

Area of Science:

• Microbiology
• Bacterial Pathogenesis
• Genetics

Background:

• Phenotypic heterogeneity describes variations in traits not linked to genetic or environmental changes.
• Studying bacterial populations is shifting from population averages to single-cell analyses.
• Lipopolysaccharide (LPS) structure variation is crucial for Gram-negative bacterial virulence.

Purpose of the Study:

• To investigate the phenotypic heterogeneity of wbpL gene expression in Pseudomonas syringae.
• To analyze the distribution and implications of wbpL heterogeneity in different growth conditions and environments.

Main Methods:

• Single-cell expression analysis of the wbpL gene in Pseudomonas syringae pv. phaseolicola.
• Comparison of wbpL expression in rich medium, minimal medium, and during in planta infection.
• Spatial analysis of wbpL expression within bacterial microcolonies.

Main Results:

• wbpL expression exhibited phenotypic heterogeneity in rich medium.
• Bistable wbpL expression (WbpL^ON/WbpL^OFF subpopulations) was observed in minimal medium.
• Heterogeneous wbpL expression and comparable viability were found during in planta infection.
• Smaller apoplastic microcolonies showed higher wbpL expression levels.

Conclusions:

• The wbpL gene displays significant phenotypic heterogeneity across various conditions.
• This heterogeneity is spatially organized within microcolonies and correlates with microcolony size.
• Understanding wbpL heterogeneity is critical for bacterial virulence and pathogenesis research.