Targeted Gene Mutation in Rice Using a CRISPR-Cas9 System

Abstract

RNA-guided genome editing (RGE) using bacterial type II cluster regularly interspaced short palindromic repeats (CRISPR)–associated nuclease (Cas) has emerged as a simple and versatile tool for genome editing in many organisms including plant and crop species. In RGE based on the Streptococcus pyogenes CRISPR-Cas9 system, the Cas9 nuclease is directed by a short single guide RNA (gRNA or sgRNA) to generate double-strand breaks (DSB) at the specific sites of chromosomal DNA, thereby introducing mutations at the DSB by error-prone non-homologous end joining repairing. Cas9-gRNA recognizes targeted DNA based on complementarity between a gRNA spacer (~ 20 nt long leading sequence of gRNA) and its targeted DNA which precedes a protospacer-adjacent motif (PAM, Figure 1). In this protocol, we describe the general procedures for plant RGE using CRISPR-Cas9 system and Agrobacterium-mediated transformation. The protocol includes gRNA design, Cas9-gRNA plasmid construction and mutation detection (genotyping) for rice RGE and could be adapted for other plant species.