Seasonal dynamics alter taxonomical and functional microbial profiles in Pampa biome soils under natural grasslands

PeerJ. 2018 Jun 13:6:e4991. doi: 10.7717/peerj.4991. eCollection 2018.

Abstract

Soil microbial communities' assembly is strongly tied to changes in temperature and moisture. Although microbial functional redundancy seems to overcome taxonomical composition changes, the sensitivity and resilience of soil microbial communities from subtropical regions in response to seasonal variations are still poorly understood. Thus, the development of new strategies for biodiversity conservation and sustainable management require a complete understanding of the soil abiotic process involved in the selection of microbial taxa and functions. In this work, we used state of the art molecular methodologies (Next Generation Sequencing) to compare the taxonomic (metataxonomics) and functional (metatranscriptomics) profiles among soil samples from two subtropical natural grasslands located in the Pampa biome, Brazil, in response to short-term seasonal variations. Our data suggest that grasslands maintained a stable microbial community membership along the year with oscillation in abundance. Apparently soil microbial taxa are more susceptible to natural climatic disturbances while functions are more stable and change with less intensity along the year. Finally, our data allow us to conclude that the most abundant microbial groups and functions were shared between seasons and locations reflecting the existence of a stable taxonomical and functional core microbiota.

Keywords: 16S rRNA gene; Abiotic factors; Ion Torrent PGM; Metataxonomics; Metatranscriptomics; NGS; Seasons; Soil microbial core; Subtropical ecosystems.

Grants and funding

This study was funded by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Amparo à Pesquisa do Rio Grande do Sul (FAPERGS) and by the Brazilian Microbiome Project (http://www.brmicrobiome.org). Victor S. Pylro received a fellowship from FAPESP (Process number 2016/02219-8). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.