Strong pairwise interactions do not drive interactions in a plant leaf associated microbial community

Area of Science:

• Plant-microbe interactions
• Microbiome research
• Synthetic microbial communities

Background:

• Microbial communities can enhance plant growth and resilience to climate change.
• Understanding microbe-microbe interactions is crucial for designing effective microbial consortia.
• Previous studies often focused on pairwise interactions, potentially missing community-level dynamics.

Purpose of the Study:

• To investigate the dynamics of a synthetic microbial community (SynCom) from Arabidopsis thaliana leaves.
• To elucidate factors shaping SynCom composition and stability.
• To compare in vitro pairwise interactions with in planta community interactions.

Main Methods:

• Assembly of a synthetic microbial community (SynCom) from Arabidopsis thaliana.
• In vitro pairwise interaction assays.
• In planta correlation network analysis using co-abundance data.
• Co-cultivation experiments to identify specific interaction drivers.

Main Results:

• Discrepancies were observed between in vitro pairwise interactions and in planta correlation networks.
• Secondary metabolites like pseudobactin showed in vitro antimicrobial activity but negligible in planta impact.
• Dominant SynCom members showed positive correlations, suggesting synergistic interactions driven by factors like exopolysaccharides and biotransformation.
• Only two in planta correlations matched in vitro pairwise interactions.

Conclusions:

• Microbe-microbe interactions in plant microbiomes are complex and context-dependent.
• Synergistic interactions, rather than competition, may dominate in stable synthetic microbial communities.
• Microbiome-wide interaction studies and synthetic communities are essential for understanding and manipulating plant microbiomes for enhanced plant health and resilience.