Graduate Research Assistant Michigan State University Okemos, Michigan
Body of Abstract: As the global climate continues to change, drought conditions are increasingly prevalent worldwide, impacting regions important for soybean production. Soybeans are an economically relevant crop in many countries, including the United States, and drought negatively impacts soybean health, yield, and root microbiome composition. In an effort to combat the effects of drought, many companies have begun developing biostimulant products containing microorganisms, often promoted for their beneficial properties, including increased plant growth and resistance to abiotic stressors. However, the influence on soybean microbiome assembly is unknown. Two microbial seed treatment biostimulants of interest due to their varied composition include a small community of approximately twenty bacterial strains, BioBuild Soy BioST + R, and a fungal monoculture of Trichoderma virens, SabrEx for Soybeans PB. Sterile Golden Harvest soybean seeds were inoculated with Bio ST+R or SabrEx prior to planting. These soybeans were grown in a greenhouse setting until plants reached developmental stage V2, then were subjected to drought and water withholding conditions. Relative water content (RWC) and stomatal conductance were measured, and qRT-PCR was conducted as indicators of plant health and overall plant stress. To connect these data to changes in soybean microbiome, 16S rRNA amplicon sequencing and ITS amplicon sequencing of the rhizosphere will be done to determine the composition of the microbial community surrounding the root systems. Combating increasing drought conditions is important to maintaining soybean crops, opening a door to these potential biological aids. More testing and analysis must be done to determine the exact influence of these biostimulants on soybean health and microbiome composition under drought conditions, but the potential benefits warrant further investigation.