ena-STUDY-INRA-CMSE-12-05-2014-13:47:40:902-79
Improving Soil Bacterial Taxa-Area Relationships Assessment Using DNA Meta-Barcoding
The evaluation of the Taxa-Area Relationship (TAR) with molecular fingerprinting data has demonstrated the spatial structuration of soil microorganisms and raised insights into the processes shaping their diversity. Today, the increasing use of massive sequencing technologies in biodiversity investigations raises the question of its gain compared to fingerprinting approach for broad-scale biogeography studies to better understand the determinism of soil microbial community assembly. The objectives of this study were to compare DNA fingerprinting and Meta-Barcoding approaches for the evaluation of soil bacterial TAR and the determinism of soil bacterial community assembly on a broad scale. This comparison was performed on 392 soil samples distributed into four French geographic regions with different levels of environmental heterogeneity. Both molecular approaches demonstrated a TAR with a significant slope, but turnover rates estimated were significantly higher and more robust with Meta-Barcoding due to its better sensitivity for soil bacterial community richness description. These two approaches were also useful in evidencing processes shaping bacterial diversity variations on a broad scale. Different taxonomic resolutions together with Sorensen or Unweighted UniFrac indexes were considered for Meta-Barcoding data. These significantly influence the estimation of the turnover rates but did not affect the relative importance of each process. Altogether, DNA Meta-Barcoding provides a more sensitive and robust evaluation of the TAR and may lead to reexamine the processes shaping soil bacterial community assembly, particularly in the context of up-scaling studies. This would raise new insights for soil microbial ecology in a context of sustainable use of soil resources.
The evaluation of the Taxa-Area Relationship (TAR) with molecular fingerprinting data has demonstrated the spatial structuration of soil microorganisms and raised insights into the processes shaping their diversity. Today, the increasing use of massive sequencing technologies in biodiversity investigations raises the question of its gain compared to fingerprinting approach for broad-scale biogeography studies to better understand the determinism of soil microbial community assembly. The objectives of this study were to compare DNA fingerprinting and Meta-Barcoding approaches for the evaluation of soil bacterial TAR and the determinism of soil bacterial community assembly on a broad scale. This comparison was performed on 392 soil samples distributed into four French geographic regions with different levels of environmental heterogeneity. Both molecular approaches demonstrated a TAR with a significant slope, but turnover rates estimated were significantly higher and more robust with Meta-Barcoding due to its better sensitivity for soil bacterial community richness description. These two approaches were also useful in evidencing processes shaping bacterial diversity variations on a broad scale. Different taxonomic resolutions together with Sorensen or Unweighted UniFrac indexes were considered for Meta-Barcoding data. These significantly influence the estimation of the turnover rates but did not affect the relative importance of each process. Altogether, DNA Meta-Barcoding provides a more sensitive and robust evaluation of the TAR and may lead to reexamine the processes shaping soil bacterial community assembly, particularly in the context of up-scaling studies. This would raise new insights for soil microbial ecology in a context of sustainable use of soil resources.