Engineered xCas9 and SpCas9-NG variants broaden PAM recognition sites to generate mutations in Arabidopsis plants.

The clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9) system has been widely used for genome modification in various species, including plants (Hsu et al., 2013; Wang et al., 2015). This customized endonuclease system includes two components: a single guide RNA (sgRNA) consisting of an artificial fusion of a crRNA and a tracrRNA for target recognition and the Cas9 endonuclease for targeted DNA cleavage. A specific protospacer adjacent motif (PAM) near the target site is essential for endonuclease recognition. This article is protected by copyright. All rights reserved.