Relative abundances of the operational taxonomic units (OTUs) that occurred in the 16S rRNA gene clone libraries of soybean leaf-associated bacteria and responded to nodulation phenotype and nitrogen fertilization conditions. The abundance of each OTU (defined by ≥97% identity) corresponds to the data in Fig. 5. E, Enrei; 12, En 1282; 13, En 1314; 65, En 6500; S4, Sakukei 4.