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Quorum-quenching limits quorum-sensing exploitation by signal-negative invaders.
Mélanie Tannières1, Julien Lang1, Claudie Barnier1
1Institute for Integrative Biology of the Cell (I2BC), CNRS CEA Univ. Paris-Sud, Université Paris-Saclay, Avenue de la Terrasse, Gif-sur-Yvette 91198, France.
Scientific Reports
|January 6, 2017
Summary
Quorum-sensing (QS) signal-altered bacteria evolved improved growth. Enzymatic QS signal inactivation by Agrobacterium tumefaciens limits QS exploitation by QS signal-negative mutants.
Area of Science:
- Microbiology
- Bacterial genetics
- Evolutionary biology
Background:
- Bacteria use quorum-sensing (QS) signals to coordinate behaviors like plasmid transfer.
- QS signal-altered mutants can emerge, but their policing and QS exploitation are poorly understood.
- Agrobacterium tumefaciens uses its Ti-plasmid for QS signal synthesis and sensing to promote transfer.
Purpose of the Study:
- Investigate the emergence and characteristics of QS-altered Agrobacterium tumefaciens mutants.
- Explore mechanisms that limit QS exploitation by QS signal-negative mutants.
- Determine the role of QS signal inactivation in controlling QS exploitation.
Main Methods:
- Experimental evolution of Agrobacterium tumefaciens.
- Genome sequencing of evolved mutants.
- Analysis of Ti-plasmid conjugation and QS signal synthesis/sensing.
- Investigation of QS signal inactivation by enzymatic degradation.
Main Results:
- QS-altered A. tumefaciens mutants with improved growth emerged during experimental evolution.
- Mutants displayed defects in QS signal synthesis, Ti-plasmid conjugation (traR mutations), or QS signal exploitation.
- Agrobacterium tumefaciens' capacity to enzymatically inactivate QS signals attenuated the dissemination of QS signal-negative Ti-plasmids.
Conclusions:
- Enzymatic QS signal disruption, whether encoded by the Ti-plasmid, a companion plasmid, or a recipient plasmid, can control QS exploitation by QS signal-negative mutants.
- This enzymatic QS disruption serves as a policing mechanism against QS signal-negative invaders.
- Understanding these mechanisms is crucial for managing bacterial communication and plasmid transfer.
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