The nutritional niche – A crucial factor in bee fitness and pathogen virulence

• Applicant: Professorin Dr. Sara Diana Leonhardt
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 550184494

The decline of bee populations and subsequent reduction in pollination services pose significant threats to ecosystems and agricultural productivity. Various factors, including intensified land use, habitat loss, pesticide use, climate change, and pathogens, contribute to this decline. Most of these factors are directly or indirectly linked to floral resources and thus bee nutrition. In this WEAVE project, we want to joint our complementary expertise to elucidate the critical link between bee health and nutrition at a molecular scale, focusing on pollen as major nutritional source for developing bees. We will investigate the effect of different pollen molecules on bee health and their role in mediating interactions with pathogens. Our objectives include (1) identifying key pollen molecules defining the nutritional niche of different bee species, (2) understanding changes in nutritional niches in relation to pathogen infection, and (3) identifying resilience molecules associated with bee tolerance and/or resistance to pathogen pressure. Our mechanistic approach involves field surveys to collect bee and pollen samples, chemical analysis of pollen to identify key molecules, and lab assays to validate field observations. Here, we can also make use of and expand already existing datasets on (i) pollen plant-bee interactions and (ii) pollen chemistry. Additionally, we will conduct novel metabolomics analyses to understand the metabolic pathways involved in bee-pathogen interactions and use genomic-scale metabolic modeling to categorize different bee species based on their metabolic similarities. We will first focus on two model bee species (Bombus and Osmia) and then expand our approach to other wild bee species. We hypothesize that specific nutrients and other pollen molecules as well as their ratios define the nutritional niche of different bee species, are linked to specific metabolic pathways responding to pathogen stress, and play crucial roles in driving bee health and resilience to pathogens across bee species. Furthermore, we hypothesize that pathogens exert greater pressure on bee populations experiencing nutritional stress and that shared nutrients among bee species lead to exploitative resource competition. By synthesizing our findings, we aim to enhance our understanding of the mechanisms underlying plant-pollinator networks and promoting network stability.

• DFG Programme: Research Grants
• International Connection: Belgium
• Partner Organisation: Fonds Wetenschappelijk Onderzoek - Vlaanderen ; Research Foundation Flanders (FWO)
• Cooperation Partner: Professor Dr. Ivan Meeus