Functional characterization of BoGL5 by an efficient CRISPR/Cas9 genome editing system in broccoli

Abstract

CRISPR/Cas9 has been widely used for precise and efficient genome editing in a number of organisms, notably in major crops, for gene function characterization and trait improvement. However, the application of this genome editing tool is very limited in Brassica oleracea, especially in broccoli (Brassica oleracea var. italica). Here, we report that the genome of broccoli, a worldwide important Brassicaceae vegetable, can also be precisely edited by a CRISPR/Cas9 system with multiple single-guide RNA-expressing cassettes. The gene BoGL5, previously identified as a candidate for the glossy green mutant, was chosen as the target gene. We generated 14 T0 transgenic plants, among which 14.3% and 50% produced mutations at the expected position in targeted regions 1 and 2, respectively. Two of them with a 100% mutation rate showed a glossy green phenotype and dramatically reduced cuticular wax load. These results indicate that CRISPR/Cas9 can be used as a promising technique for gene functional verification and trait improvement in broccoli.