Mutation of storage protein gene using CRISPR/Cas9 removed α′-subunit of β-conglycinin in soybean seeds

β-Conglycinin (7S) and glycinin (11S) are the two major storage proteins in soybean seeds. Storage proteins occupy a large portion of soybean seeds, which is the main obstacle to accumulating additional foreign proteins. Thus, we produced 7S-edited soybean plants using CRISPR/Cas9 via Agrobacterium-mediated transformation. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis confirmed that the α′-subunit (76 kDa) of β-conglycinin protein disappeared from the 7S-edited T2 line (#19–8). The removal of the band was caused by the early termination of the CG-1 gene by insertion/deletion (in/del) mutations with an efficiency of 78.5% generated by genome editing. Soybeans with low-storage proteins could be used for improved foreign protein production in seed.