The North American tallgrass prairie is a relatively understudied ecosystem that is increasingly threatened as global climate change increases average temperatures and drought frequency. Fire suppression, plowing under of native grasses, and the replacement of native plants with monoculture has altered the native soil and plant microbial communities. Associated microbial communities assist in the ability to adapt to extreme environmental conditions for many grasses. Tripsacum dactyloides (Eastern gamagrass) is a perennial grass native that has a large range across central North America, and has shown both drought tolerance properties and the ability to withstand periodic flooding. We obtained plant-conditioned soil from 70 diverse, native genotypes of T. dacyloides, each originating from a unique site across an east-west precipitation gradient present in Texas. These were generation 1 plants. We inoculated 8 replicate pots of sterile soil with each "genotype" of conditioned soil, and grew a cultivar (nonnative) of T. dacyloides from seed in this innoculated soil. These were Generation 2 plants. When then subjected 4 replicate Generation 2 plants to either a drought treatment or a well-watered treatment each. We hypothesized that microbes conditioned by first generation, drought adapted plants would help generation 2 plants tolerate stress better under drought conditions.
Results/Conclusions
Preliminary results have shown that drought adapted microbes help plants that are not adapted to drought tolerate stress better, regardless of watering treatment. There was increased root growth in generation 2 plants that were grown in conditioned soil from generation 1 plants that were drought adapted (p=0.002). The use of drought adapted microbes can help ensure healthy tall grass prairie function and findings from this research can be applied to conservation work in this fragile ecosystem. A greater understanding of the symbiosis between plants and their microbial communities is essential for developing more tolerant crops as agricultural systems are impacted by global shifts in climate patterns.
