Two-way microscale interactions between immigrant bacteria and plant leaf microbiota as revealed by live imaging

Area of Science:

• Microbiology
• Plant Science
• Ecology

Background:

• The phyllosphere, or plant aerial surfaces, hosts diverse microbial communities.
• Bacterial cell arrangement on leaves is non-random and linked to leaf topography.
• Microscale interactions between bacteria on leaf surfaces are poorly understood.

Purpose of the Study:

• To investigate how interactions between immigrant bacteria and resident microbiota impact community spatial organization.
• To analyze the microscale spatial dynamics of Pseudomonas fluorescens A506 and Pseudomonas syringae B728a with native leaf microbiota.

Main Methods:

• Utilized a simplified in vitro system for live imaging.
• Studied spatial organization at the micrometer scale.
• Introduced specific bacterial strains to their corresponding native plant leaf microbiota.

Main Results:

• Observed significant co-localization between immigrant and resident microbial cells at micrometer distances.
• Found that resident microbiota cells preferentially attached near newly formed P. fluorescens aggregates.
• Demonstrated two-way interactions influencing microscale spatial organization.

Conclusions:

• Immigrant-resident bacterial interactions significantly affect the microscale spatial organization of leaf microbiota.
• These findings may extend to other surface-associated microbial communities.
• Understanding these interactions is crucial for phyllosphere ecology and biocontrol strategies.