Foliar fungal communities in agroecosystems depend on crop identity and neighboring vegetation

Authors: Whitaker, Briana; HEINIGER, RYAN - North Carolina State University; HAWKES, CHRISTINE - North Carolina State University

Submitted to: Frontiers in Microbiomes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2023
Publication Date: 7/13/2023
Citation: Whitaker, B.K., Heiniger, R.W., Hawkes, C.V. 2023. Foliar fungal communities in agroecosystems depend on crop identity and neighboring vegetation. Frontiers in Microbiomes. 2. Article 1216462. https://doi.org/10.3389/frmbi.2023.1216462.
DOI: https://doi.org/10.3389/frmbi.2023.1216462

Interpretive Summary: The microbial communities living on crops can greatly contribute to overall plant health and productivity, but it remains unclear how intensive agricultural practices have shaped the crop microbiome. Researchers in North Carolina, in collaboration with ARS researchers in Peoria, Illinois, discovered that the dominance of crops, at the cost of natural vegetation, across the landscape can lead to reduced fungal biodiversity in leaves on corn, soy, switchgrass, and wheat crops. Additionally, researchers identified major differences in the composition of the microbiome according to crop type, largely due to the differences among crops in their growth yield traits and growing season. This knowledge can be applied to understand how microbes disperse between natural and agricultural plants and indicates that intensive agricultural practices may have broad consequences for the role of microbiomes in crop health.

Technical Abstract: Agricultural intensification causes loss of plant diversity and homogenization of environmental conditions, which may result in changes to plant-microbiome interactions that can mediate plant growth and stress tolerance. Here, we hypothesized that foliar fungal microbiomes would depend on local biotic (crop) and abiotic (environmental) filters, constrained by neighboring natural vegetation that we expected to serve as a fungal source. To test these ideas, we sampled foliar fungi from four crops, nine varieties, and 16 sites across a 500-km expanse in North Carolina, USA and tested the role of climate, soil, plant performance, and vegetative landcover characteristics on the microbiome. Our results indicated that reduced natural vegetative cover in the surrounding landscape decreases fungal richness and leads to more homogeneous microbiome assembly within sites. Additionally, crop species and site acted as major drivers of community structure, primarily due to differences in crop productivity traits and growing season. Based on these results, crossover between natural and agricultural ecosystems plays an important role in crop microbiome development, meaning that any attempts at agricultural microbiome management must also consider landscape management to maintain diversity. Future work should address the specific mechanisms behind landcover differences driving these exchanges and how they impact crop microbiome function.