Contrasting Rhizosphere Nitrogen Dynamics in Andropogoneae Grasses: Implications for Sustainable Agriculture

Hsu, S.-K.; Emmett, B. D.; Haffke, A. J.; Costa-Neto, G.; Schulz, A. J.; Lepak, N.; La, T.; AuBuchon-Elder, T. M.; Hale, C. O.; Raglin, S. S.; Ojeda-Rivera, J. O.; Kent, A. D.; Kellogg, E. A.; Romay, M. C.; Buckler, E. S.

doi:10.1101/2024.06.03.597142

bioRxiv · 10.1101/2024.06.03.597142

Contrasting Rhizosphere Nitrogen Dynamics in Andropogoneae Grasses: Implications for Sustainable Agriculture

Hsu, S.-K.·Emmett, B. D.·Haffke, A. J.·Costa-Neto, G.·Schulz, A. J.·Lepak, N.·La, T.·AuBuchon-Elder, T. M.·Hale, C. O.·Raglin, S. S.·Ojeda-Rivera, J. O.·Kent, A. D.·Kellogg, E. A.·Romay, M. C.·Buckler, E. S.

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Abstract

Background: Nitrogen (N) fertilization in crop production significantly impacts ecosystems, often disrupting natural plant-microbe-soil interactions and causing environmental pollution. Our research tested the hypothesis that phylogenetically related perennial grasses might preserve rhizosphere management strategies conducive to a sustainable N economy for crops. Method: We analyzed the N cycle in the rhizospheres of 36 Andropogoneae grass species related to maize and sorghum, investigating their impacts on N availability and losses. This assay is supplemented with the collection and comparison of native habitat environment data for ecological inference as well as cross-species genomic and transcriptomic association analyses for candidate gene discovery. Result: Contrary to our hypothesis, all examined annual species, including sorghum and maize, functioned as N "Conservationists," reducing soil nitrification potential and conserving N. In contrast, some perennial species enhanced nitrification and leaching ("Leachers"). Yet a few other species exhibited similar nitrification stimulation effects but limited NO3- losses ("Nitrate Keepers"). We identified significant soil characteristics as influential factors in the eco- evolutionary dynamics of plant rhizospheres, and highlighted the crucial roles of a few transporter genes in soil N management and utilization. Conclusion: These findings serve as valuable guidelines for future breeding efforts for global sustainability.

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Hsu, S.-K., Emmett, B. D., Haffke, A. J., Costa-Neto, G., Schulz, A. J., Lepak, N., La, T., AuBuchon-Elder, T. M., Hale, C. O., Raglin, S. S., Ojeda-Rivera, J. O., Kent, A. D., Kellogg, E. A., Romay, M. C., Buckler, E. S.. 2024-06-03. Contrasting Rhizosphere Nitrogen Dynamics in Andropogoneae Grasses: Implications for Sustainable Agriculture. https://doi.org/10.1101/2024.06.03.597142

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