Plant microbiomes harbor potential to promote nutrient turnover in impoverished substrates of a Brazilian biodiversity hotspot

The Brazilian campos rupestres, a grassland ecosystem with extremely low phosphorus and nitrogen concentrations, harbors a significant portion of Brazilian plant diversity. This study investigates the taxonomic profile, compositional and functional differences, and nutrient turnover potential of microbial communities associated with two Velloziaceae plant species growing on distinct substrates (soil and rock). Amplicon sequencing and metagenomic analysis revealed that despite compositional differences, a core microbiome exists, enriched in genes involved in organic compound intake and phosphorus and nitrogen turnover. The potential for phosphorus transport, mineralization, and solubilization is mainly found in bacterial families like Xanthobacteraceae and Bryobacteraceae. A lineage of Isosphaeraceae acquired nitrogen-fixing potential via horizontal gene transfer and might be involved in nitrification. Plant-associated microbial populations in the campos rupestres possess a genetic repertoire with the potential to increase nutrient availability.

Antonio P. Camargo, Rafael S. C. de Souza, Juliana Jose, Isabel R. Gerhardt, Ricardo A. Dante, Supratim Mukherjee, Marcel Huntemann, Nikos C. Kyrpides, Marcelo F. Carazzolle, Paulo Arruda