We congratulate Stéphane Hacquard on the ERC Starting Grant “MICRORULES” that was awarded to him for the next five years (September 2017 - August 2022): Structural and Functional Architectures of Multi-Kingdom Microbial Consortia Colonizing Plant Roots
In nature, the roots of healthy and asymptomatic plants associate with a variety of microbes, including bacteria, fungi and oomycetes (i.e. the root microbiota) that form complex microbial consortia that impact plant growth and productivity. In such multitrophic complexes microbes coexist and interact, forming physically and metabolically interdependent consortia that harbour properties that are distinct when compared to those of the constituent pars. Paradoxically, while microbiome studies investigating the complexity of microbial communities are abundant, systematic research capturing the diversity of microbes across individual classes is sparse. It is likely that both plant-microbe and microbe-microbe interactions are equally important in sculpting root-associated microbial assemblages in nature. However, it remains unclear whether cooperative or competitive interactions within or between microbial classes are important organizational determinants governing microbial colonization on plants and to which extent microbe-microbe interactions along the soil-root continuum can benefit the host. Understanding the organizational principles underlying the establishment of complex microbial consortia on plant roots as well as their functional impact on host health in nature remains challenging.
The ERC-funded “MICRORULES” project aims at addressing these important ecological concepts through the combination of high-throughput microbial profiling methods, large-scale microbial species isolation, and microbiota reconstitution experiments with germ-free plants. This project will contribute to the transition from a descriptive to a mechanistic understanding of the plant root microbiota. Elucidating assembly rules and functional capabilities of complex root-associated microbial consortia represent the basis of further predictions regarding how the plant microbiota respond to biotic or abiotic perturbations and to anticipate repercussions on plant growth and health.