design: At the soybean vegetative stage, endosphere soil samples from three plants in each treatment were collected for DNA extraction. Genomic DNA of root endosphere fraction was extracted using a PowerSoil kit (Qiagen, Valencia, CA, USA) . The V4  V5 region of the 16S rRNA gene was amplified with the  515F/926R primer pair (Parada, Needham, and Fuhrman 2016; Quince et al. 2011). The PCR product was diluted 1:100 with molecular-grade water. The diluted amplicons were indexed using barcoded PCR primers (Gohl, et al., 2016). Barcoded amplicons were normalized using SequalPrep kits (Invitrogen).