Gene Editing in Chrysanthemum Using Multicopy Transgenes as Targets

The CRISPR-Cas9 system has emerged as the main technique for generating targeted mutations in genomes. However, introducing mutations into higher polyploid plant species, especially those without genome information, has been difficult. Mitsuko Kishi-Kaboshi from the National Agriculture and Food Research Organization In Japan attempted to perform gene editing using the CRISPR-Cas9 system to introduce mutations into chrysanthemum (Chrysanthemum morifolium), a hexaploid plant.

Their team constructed transgenic chrysanthemum plants expressing the yellowish-green fluorescent protein gene from Chiridius poppei (CpYGFP). The team then targeted CpYGFP for gene editing, selecting two sgRNAs to target different positions in the CpYGFP gene. The team then obtained the transgenic calli containing mutated CpYGFP genes (CRISPR−CpYGFP-chrysanthemum).

Analysis, as well as fluorescence observations, indicated that cells containing the mutated CpYGFP gene grew independently of cells containing the original CpYGFP gene in one callus. From here they obtained the CRISPR−CpYGFP-chrysanthemum shoot containing a mutation in the CpYGFP sequence.

This study is the first report of gene editing using the CRISPR-Cas9 system in chrysanthemum.

For more information, read the article in Plant & Cell Physiology.