Insights into Plant Interactions and the Biogeochemical Role of the Globally Widespread Acidobacteriota Phylum

The prevalence and abundance of Acidobacteriota raise concerns about their ecological function and metabolic activity in the environment. Studies have reported the potential of some members of Acidobacteriota to interact with plants and play a significant role in biogeochemical cycles. However, their role in this context has not been extensively studied. Here, we performed a comprehensive genomic analysis of 758 metagenome-assembled genomes (MAGs) and 121 RefSeq genomes of Acidobacteriota. Our analysis revealed a high frequency of plant growth-promoting traits (PGPTs) genes in the Acidobacteriaceae, Bryobacteraceae, Koribacteraceae, and Pyrinomonadaceae families. These PGPTs include genes involved in nitrogen fixation, phosphorus solubilization, exopolysaccharide production, siderophore production, and plant growth hormone production. Expression of such genes was found to be transcriptionally active in different environments. In addition, we identified numerous carbohydrate-active enzymes and peptidases involved in plant polymer degradation. By applying an in-depth insight into the diversity of the phylum, we expanded previous role in carbon, nitrogen, sulfur, and trace metal cycling. This study underscores the distinct potential ecological roles of each of these taxonomic groups, providing valuable insights for future research.