Genome editing provides a valuable biological toolkit for soybean improvement

Soybean [Glycine max (L.) Merr.] is a major economic crop and is used as food, animal feed, and biofuel because of its high contents of oil and proteins. Improvements in soybean quality and yield have so far been achieved using traditional and molecular breeding, including hybridization, mutagenesis, and the insertion of transgenes. However, the breeding of new soybean varieties was unexpectedly prolonged by genetic limitations, such as genomic duplication and redundancy, and complicated social issues caused by the insertion of transgenes. The use of genome-editing technologies for the genetic manipulation of soybean has revolutionized the study of genetic variations, as well as soybean improvement, over the past few years. Here, we summarize the applications of genome editing technologies including zinc finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN), and clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein nuclease 9 (Cas9), in soybean. We discuss targeted gene mutagenesis using current genome-editing technologies, with a focus on the implementation and potential availability of new technical developments in soybean. The accurate, user-friendly approach afforded by CRISPR/Cas9 technology will not only facilitate functional studies of soybean genes but also accelerate soybean breeding for future soybean improvement.