Soil microbial networks: what is the relationship with plants?

Abstract

International audienceSince a long time, the interactions between soil microbes and plant roots are intensively investigated to decipher the role of microorganisms in the growth and the maintenance of plants in a multitude of environmental conditions as climatic stress, agricultural practices or pathogenic/parasitic invasions. Beyond their intimate relationships, the soil microbial communities influence and are influenced by the aboveground vegetation. The interaction/co-occurrence networks are a relatively new look on the soil microbial communities. This look integrates the most comprehensively the community complexity, provides a more complete information on the community and seems to be more sensitive to biotic and abiotic changes than classical microbial indicators (diversity level, community composition, …). Due to the methodological approach used to study them, it is difficult to break through the biological underlying mechanisms. Nevertheless, the collection of empirical results in the literature evidenced an obvious interplay between the state of soil microbial networks and the aboveground plant communities and the edaphic conditions. From the scale of plot to the scale of a whole territory, I will illustrate how the soil microbial networks are related to the plant cover, to the plant phenology and to the soil resistance to plant-pathogens