Gene-targeting technologies using sequence specific nucleases have been widely adopted to induce genetic modifications in plant genome, of which generating targeted point mutation for gain-of-function phenotype is of great value. Although tremendous efforts have been made in developing gene insertion or replacement approaches by harnessing DNA repair pathways through either homologous recombination or non-homologous end joining mechanisms, introducing specific DNA sequence changes into genome at the desired site remains challenging. Recently, researchers at State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection of CAAS have reported A CRISPR/Cas9 toolkit for efficient targeted base editing to induce genetic variations in rice.

Targeted base editing in rice using the rBE3 and rBE4 system

This study presents an engineered Cas9 amino deaminase, rBE3, in generating gain-of-function rice mutants of OsSERK1(D428N), OsSERK2(D433N) and ipa1(S918F) genes though C > T (G > A) conversions at the target sites in rice genome with high efficiency. Furthermore, to expand the application of base editing in rice, rBE4 which recognizes different PAM sequences was also constructed and used to induce genetic variations at the key locus of rice blast susceptible gene pi-ta. Those data imply that the rBE3/rBE4 system would be a promising toolkit for generating gain-of-function mutants for fundamental molecular biology researches and materials with genetic variation for rice breeding in future.

More details are available at the bellow link:
http://engine.scichina.com/publisher/scp/journal/SCLS/doi/10.1007/s11427-016-0406-x?slug=abstract

By Huanbin Zhou
hbzhou@ippcaas.cn