We have made substantial progress this year, advancing our research on soybean's response to AMF and rhizobium under field conditions. Agronomic data has been collected, with yield and nutrient uptake measurements to follow at the end of the season. A major milestone was the completion of single-cell RNA sequencing from key samples (four nodulations and four AMF-infected roots), which allowed us to identify significant genes associated with AMF/rhizobium infection, colonization, nodule development, arbuscule maturation, and nutrient uptake. Notably, we discovered novel genes involved in these processes, and functional validation is currently in progress. Furthermore, we identified large-effect variants in the natural soybean germplasm, and these accessions, procured from USDA-GRIN, are now being evaluated in both greenhouse and field conditions under various fertilizer and microbial treatments.

The advancements made through this research offer significant potential benefits to U.S. soybean farmers. By identifying key genes and natural variants that enhance soybean responses to AMF and rhizobium, we are paving the way for the development of soybean lines with improved nutrient uptake and resilience. This could lead to higher yields with reduced reliance on chemical fertilizers, lowering input costs and promoting sustainable farming practices. Additionally, understanding the role of beneficial microbes and incorporating them into agricultural practices will help farmers increase productivity while enhancing soil health, making U.S. soybean farming more efficient and environmentally friendly.