Stephan Declerck

Stéphane Declerck is a Full Professor at the Faculty of Bioengineering of the Université catholique de Louvain (UCLouvain). He heads the Mycology Laboratory at the Earth and Life Institute and oversees the university’s Mycotheque, an internationally recognized collection within the Belgian Coordinated Collections of Microorganisms (BCCM). This collection houses approximately 30,000 strains of filamentous fungi, yeasts, and arbuscular mycorrhizal fungi, including the Glomeromycota In Vitro Collection (GINCO), the world’s largest collection of arbuscular mycorrhizal fungi. Professor Declerck leads a multidisciplinary research team of approximately 35 scientists and staff members. The laboratory’s research focuses on:

• First bullet point
• Second bullet point
• Third bullet point
• Role of symbiotic organisms in agriculture, particularly their contributions to agroecological processes, ecosystem services, and resistance to abiotic and biotic stresses in major crops such as wheat, maize, and potato.

Plants require essential nutrients such as nitrogen and phosphorus for growth, development, and biomass production. However, these nutrients are often present in forms that are not readily available or are located in soil microsites that are inaccessible to roots and root hairs. To overcome these limitations, plants establish beneficial interactions with soil microorganisms in an environment called the rhizosphere. This environment has long been considered the primary interface for interactions between plants and soil microorganisms. However, a growing body of research suggests that the soil surrounding the hyphae of the root symbiont arbuscular mycorrhizal fungi (AMF), called the hypho-sphere, is an equally important compartment, although it remains largely unexplored. The hypho-sphere hosts diverse microbial communities that interact with both AMF and plants. Inter-Kingdom social interactions as well as chemical exchanges between AMF and hypho-sphere-associated bacteria play key roles in plant nutrition and protection against pathogens. At broader spatial scale, these hyphae interconnect multiple plants through common mycorrhizal networks (CMNs), integrating plants and their associated microbial communities into complex belowground ecological networks. In this context, the hypho-sphere appears as an integrative functional niche, structured by both top-down and bottom-up regulatory processes, resulting from multiple interactions between plants, AMF and bacteria.

This presentation will highlight the AMF hypho-sphere as a key microbial hub that supports plant nutrition, health, and pathogen control. Understanding these interactions provides new opportunities for developing sustainable agricultural practices that reduce dependence on chemical fertilizers and pesticides.