Elevated CO2 induces phyllosphere community changes in soybean

Abstract

Plant-associated microbiomes play significant roles in determining their hosts responses to stress, which is increasingly common in a rapidly changing world. For example, foliar endophytes can increase tolerance to drought and decrease herbivory. Global atmospheric changes, such as increased atmospheric carbon dioxide concentration ([CO2]), have the potential to directly and indirectly alter microbiome community structure in ways that affect host plants underscoring our need to understand how microbial communities in planta will change under global change. Here, we used a metabarcoding approach to assess community composition and network structure of bacterial and fungal phyllosphere microbiomes within soybean (Glycine max) exposed to ambient and elevated [CO2] in the field. We found that fungal community composition differed between soybean grown in elevated and ambient [CO2], while bacterial communities did not. Additionally, co-occurrence networks for both fungi and bacteria in elevated [CO2] exhibited marked changes compared to the ambient networks including the composition of hub taxa. Overall, our findings suggest that anthropogenic change, such as elevated [CO2], can cause profound shifts in community assembly of microbes within their plant hosts. Our findings may aid those developing agro-ecological strategies using microbes to improve crop traits, which necessitates understanding the drivers of microbiome community structure. HighlightLeaf-associated microbes benefit plants, but how climate change affects these communities remains unclear. We found that elevated CO2 shifted fungal and bacterial community composition and network structure within soybean leaves.