Journal Article

Agricultural intensification reduces microbial network complexity and the abundance of keystone taxa in roots

van der Heijden, Marcel G. A., Walder, Florian, Keller, Thomas, Büchi, Lucie, Held, Alain Y., Meyer, Marcel, Banerjee, Samiran, Charles, Raphael, Gattinger, Andreas

2019

Overview

Root-associated microbes play a key role in plant performance and productivity, making them important players in agroecosystems. So far, very few studies have assessed the impact of different farming systems on the root microbiota and it is still unclear whether agricultural intensification influences the structure and complexity of microbial communities. We investigated the impact of conventional, no-till, and organic farming on wheat root fungal communities using PacBio SMRT sequencing on samples collected from 60 farmlands in Switzerland. Organic farming harbored a much more complex fungal network with significantly higher connectivity than conventional and no-till farming systems. The abundance of keystone taxa was the highest under organic farming where agricultural intensification was the lowest. We also found a strong negative association ( R 2  = 0.366; P  < 0.0001) between agricultural intensification and root fungal network connectivity. The occurrence of keystone taxa was best explained by soil phosphorus levels, bulk density, pH, and mycorrhizal colonization. The majority of keystone taxa are known to form arbuscular mycorrhizal associations with plants and belong to the orders Glomerales , Paraglomerales , and Diversisporales . Supporting this, the abundance of mycorrhizal fungi in roots and soils was also significantly higher under organic farming. To our knowledge, this is the first study to report mycorrhizal keystone taxa for agroecosystems, and we demonstrate that agricultural intensification reduces network complexity and the abundance of keystone taxa in the root microbiome.

• Publisher: Nature Publishing Group UK,Oxford University Press
• Subject: 631/326/2565/855 / 704/158 / Abundance / Agricultural and Veterinary Sciences / Agricultural ecosystems / Agricultural land / Agriculture / Agriculture, Forestry and Fisheries / Arbuscular mycorrhizas / Biological Sciences / Biologiska vetenskaper / Biomedical and Life Sciences / Bulk density / Colonization / Complexity / Deforestation / DNA sequencing / Ecology / Ekologi / Evolutionary Biology / Farming / Farming systems / Fungi / Glomeromycota - classification / Glomeromycota - genetics / Glomeromycota - isolation & purification / Intensive farming / Jordbruk, skogsbruk och fiske / Lantbruksvetenskap och veterinärmedicin / Life Sciences / Markvetenskap / Microbial activity / Microbial Consortia / Microbial Ecology / Microbial Genetics and Genomics / Microbiology / Microbiomes / Microbiota / Microorganisms / Mycorrhizae - classification / Mycorrhizae - genetics / Mycorrhizae - isolation & purification / Natural Sciences / Naturvetenskap / No-till cropping / Organic farming / Phosphorus / Phosphorus - metabolism / Plant Roots - microbiology / Roots / Soil - chemistry / Soil Microbiology / Soil microorganisms / Soil Science / Switzerland / Triticum - microbiology / Wheat