Can plants drive succession in bacterial communities?

Title: Can plants drive succession in bacterial communities?

Speaker: Associate Professor Rebecca Case, Nanyang Technological University Singapore

Abstract: Succession is an ecosystem level process in which the community and habitat interact predictably by increasing diversity, altering the habitat, and ultimately reaching a climax community. Key to succession is the establishment of habitat forming species, providing for niche differentiation leading to increased diversity. Here, we use the primary colonizing and habitat forming seagrass, H. ovalis, to investigate if it drives succession in its microbiome and the ecosystems sediment bacterial communities. H. ovalis is a rapidly growing species that forms expanding patches at the edges of Singapore’s 201 hectares of coastal meadows. However, many of the characteristics attributed to plants for habitat modification are microbial processes such as nitrogen fixation and sulfide detoxification. We have used cronosequences (as a proxy for succession) of seagrass patches to sample bacterial communities within the meadow ecosystem and the microbiomes of H. ovalis. Molecular bacterial community analysis was performed on genes encoding habitat modifying processes and a core gene used as a proxy for diversity. We demonstrate the plant microbiome and ecosystem communities undo distinct ecological processes within the cronosequence. Building on this foundation, we have started a new seagrass project to harness seagrass microbiomes to enhance seagrass resilience under climate-driven stressors, particularly ocean warming. Notably, our ongoing experiments show that the seagrass microbiome confers thermal tolerance up to 37 °C, highlighting the untapped potential of microbial communities to buffer habitat-forming plants against future environmental change.