FIGURE 4.

Clustered regularly interspaced short palindromic repeat/Cas9-targeted mutagenesis of brassinosteroid-insensitive 1(EgBRI1) gene in in vitro oil palm plantlets. (A) Schema of gRNA targeting intronless EgBRI1 gene in oil palm. (B) Cleavage efficiency of Cas9/gRNA targeting EgBRI1 gene in oil palm protoplast. Data are average values ± SE from four independent experiments. (C) CRISPR/Cas9-induced EgBRI1 mutations at different gRNA target sites showing stunted growth and leaf apex necrosis phenotypes (boxed in blue) in transgenic oil palm shootlets and controls transformed with either Cas9 or gRNA alone. (D) Mutation frequencies of CRISPR/Cas9 mutagenesis based on the occurrence of stunted or necrotic leaf apex phenotypes in transgenic oil palm.