The CRISPR–Cas9 genome-editing system has been used to alter the genomes of two crop plants: barley (Hordeum vulgare; pictured) and Brassica oleracea, a species that includes broccoli and cabbage.

Credit: Hagen Zapf/Imagebroker/Corbis

CRISPR–Cas9 allows researchers to easily engineer mutations in genomes and has been tested in some crops, including rice and wheat. Cristobal Uauy and Wendy Harwood at the John Innes Centre in Colney, UK, used the system in barley and the brassica species to knock out the function of genes encoding certain plant hormones that are involved in growth and seed development — both important agronomic traits.

The team generated heritable mutations and the modified plants contained no foreign genes. However, the editing system occasionally introduced unwanted, off-target genetic changes.

Genome Biol. 16, 258 (2015)