NSF PRFB FY23: Host-pathogen dynamics in response to resource pulses: nutrients, immunity and disease transmission

Davis, Julie, Ithaca Ny NY

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment, and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. Globally, disease and habitat loss lead to biodiversity loss. In agricultural landscapes, bees sometimes have less food from flowering plants and can be exposed to more disease. However, mass blooming cover crops that produce large amounts of flowers could improve conditions for bees. For example, increased food supply from mass blooming crops may improve bee nutrition and disease resistance. Additionally, mass blooms could either reduce or increase chances for bees to spread diseases at shared flowers, likely depending on the amount of other, non-crop flowers in the surrounding landscape. Identifying the contexts in which different farming practices can support pollinators improves conservation efforts. This project asks how non-crop flower abundance affects the extent to which mass blooming cover crops affect bee disease resistance and spread. This research will use an agriculturally important native bee, Osmia lignaria, and its associated pathogens to evaluate how resource pulses from a cover crop (vetch, Vicia villosa) interact with the surrounding landscape (abundance of non-mass bloom floral resources, NMBR) to affect bee immunity, pathogen infection, and pathogen transmission. The fellow will place Osmia lignaria nests at sites manipulated to either have or not have mass blooming vetch. Sites in the mass bloom and control treatments will each exist along a gradient of NMBR. To assess how mass bloom affects pathogen infection, adult bees will be sampled throughout bloom, and larvae and pollen provisions will be sampled at the end of bloom to quantify pathogens and nutrients. To assess how mass bloom affects opportunities for disease transmission, total and infected bee and flower density will be quantified in vetch and NMBR patches. To assess whether mass bloom and NMBR affect immunity, the fellow will conduct an immune challenge and measure immune gene expression in bees fed pollen from diets that mimic the quality and quantity of floral resources at each site, in laboratory experiments. By disentangling landscape- versus molecular-scale drivers of host-pathogen dynamics, this work will improve predictive power of when pathogens affect populations and communities. The fellow will extend the impact of their work by 1) training two undergraduate students, 2) conducting trainings on inclusive teaching in Biology, and 3) communicating results and investigating applications with conservation and agricultural professionals. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.