Drought conditioning of rhizosphere microbiome influences maize water use traits

Authors: CARTER, KELSEY - Los Alamos National Research Laboratory; NACHTSHEIM, AGIGAEL - Los Alamos National Research Laboratory; DICKMAN, L - Los Alamos National Research Laboratory; MOORE, ERIC - Los Alamos National Research Laboratory; NEGI, SANGEETA - Los Alamos National Research Laboratory; HENEGHAN, JOHN - Los Alamos National Research Laboratory; SABELLA, ANTHONY - Los Alamos National Research Laboratory; STEADMAN, CHRISTINA - Los Alamos National Research Laboratory; ALBRIGHT, MICHAELINE - Los Alamos National Research Laboratory; ANDERSON-COOK, CHRISTINE - Los Alamos National Research Laboratory; Comas, Louise; HARRIS, ROSE - Los Alamos National Research Laboratory; HEIKOOP, JEFFREY - Los Alamos National Research Laboratory; LUBBERS, NICK - Los Alamos National Research Laboratory; MARINA, OANA - Los Alamos National Research Laboratory; MUSA, DEA - Los Alamos National Research Laboratory; NEWMAN, BRENT - Los Alamos National Research Laboratory; PERKINS, GEORGE - Los Alamos National Research Laboratory; TWARY, SCOTT - Los Alamos National Research Laboratory; YEAGER, CHRIS - Los Alamos National Research Laboratory; DUNBAR, JOHN - Los Alamos National Research Laboratory; SEVANTO, SANNA - Los Alamos National Research Laboratory

Submitted to: Plant and Soil
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2023
Publication Date: 8/12/2023
Citation: Carter, K.R., Nachtsheim, A.C., Dickman, L.T., Moore, E.R., Negi, S., Heneghan, J.P., Sabella, A.J., Steadman, C.R., Albright, M.B., Anderson-Cook, C.M., Comas, L.H., Harris, R.J., Heikoop, J.M., Lubbers, N.E., Marina, O.C., Musa, D., Newman, B.D., Perkins, G.B., Twary, S., Yeager, C.M., Dunbar, J.M., Sevanto, S. 2023. Drought conditioning of rhizosphere microbiome influences maize water use traits. Plant and Soil. 492:587-604. https://doi.org/10.1007/s11104-023-06204-2.
DOI: https://doi.org/10.1007/s11104-023-06204-2

Interpretive Summary: Soil microbes can improve plant growth and productivity under drought but we know little about how this occurs. Water-limited treatments caused clear drought legacy effects, producing plants that used water more conservatively through quicker stomatal responses to prevent water loss, and larger root systems and more dissolved organic carbon in the pots to mine for soil resources and support soil microbes. These results demonstrate that plant-associated microbiomes can be developed to alter plant drought functioning under drought after just one generation of plant growth.

Technical Abstract: Beneficial plant-microbe interactions can improve plant performance under drought; however, we know less about how rapid, drought-induced shifts in microbial communities will affect plant traits. We grew two generations of Zea mays in artificial soil inoculated with soil microbiomes originating from contrasting environments (agriculture and forest) under two irrigation treatments (well-watered and water limited; 65% and 45% relative water content, respectively). We conditioned microbial communities to a short-term drought and quantified their influence on a new generation of plants. This allowed us to investigate whether water conditioning legacies are carried forward through the microbiome to alter plants in the subsequent generation. No matter the microbiome-origin, plants grown in the microbiome with a water limited legacy produced water conservative traits, including longer roots, higher soil dissolved organic carbon, and slower volumetric water content loss during drought. A well-watered legacy produced plants that delayed permanent stomatal closure and had higher photosynthetic nitrogen use efficiency. In plants with a microbiome originating from the forest soil, a well-watered legacy and water treatment also resulted in higher rates of photosynthesis and stomatal conductance. These results demonstrate that plant-associated microbiomes can be developed to influence plant drought performance after just eight weeks of plant growth.