Chinese Academy of Sciences and partner institutions used CRISPR-Cas9 to develop a simple and highly efficient approach for mild reduction of rice amylose content, by which the rice eating and cooking quality might be improved. This is the first report about moderately decreasing rice amylose content through base editing of the Wx gene.

Compared with previous studies, the new approach induced amino acid substitution mutation to slightly reduce Wx function without affecting grain appearance. Furthermore, the appearance, quality, and yield-related traits of edited lines were not affected. All these transgene-free and homozygous lines were generated in less than one year, which indicates significant time and labor savings compared to conventional breeding. This study also shows that it is possible to develop beneficial mutations by editing amino acids close to the critical domain of the product of a target gene.

[www.isaaa.org]165