A diverse and distinct microbiome inside living trees.

Area of Science:

• Environmental microbiology
• Forest ecology
• Plant science

Background:

• Microbiome research has advanced significantly across diverse environments.
• The microbiome within living tree wood, Earth's largest biomass reservoir, remains largely unexplored.
• Understanding these internal microbial communities is crucial for comprehending tree health and ecosystem functions.

Purpose of the Study:

• To characterize the composition, structure, and function of the tree wood microbiome.
• To investigate the specialization of these microbiomes to host tree species.
• To explore the implications of tree-associated microbes for tree holobionts and ecosystem processes.

Main Methods:

• Metagenomic sequencing and analysis of microbial communities within tree woody tissues.
• Comparative analysis of microbiomes between heartwood and sapwood.
• Investigation of microbial community partitioning and specialization across different tree species.

Main Results:

• A single tree hosts approximately one trillion bacteria within its woody tissues.
• Distinct microbial communities are partitioned between heartwood and sapwood, with minimal overlap with other plant tissues.
• The heartwood microbiome represents a unique niche for specialized archaea and anaerobic bacteria involved in biogeochemical processes.

Conclusions:

• Wood is a rich reservoir of biodiversity, harboring specialized microbial communities.
• Trees function as holobionts, with internal microbiomes playing vital roles in host health and ecosystem functions.
• This research establishes a new frontier in environmental microbiology, impacting our understanding of tree physiology and forest ecology.