Author Correction: Precision genome engineering through adenine base editing in plants.

In Supplementary Fig. 1b originally published with this Brief Communication, the DNA sequence of nickase Cas9 was incorrect; this has now been amended.

Precision genome engineering through adenine base editing in plants.

The recent development of adenine base editors (ABEs) has enabled efficient and precise A-to-G base conversions in higher eukaryotic cells. Here, we show that plant-compatible ABE systems can be successfully applied to protoplasts of Arabidopsis thaliana and Brassica napus through transient transfection, and to individual plants through Agrobacterium-mediated transformation to obtain organisms with desired phenotypes. Targeted, precise A-to-G substitutions generated a single amino acid change in the FT protein or mis-splicing of the PDS3 RNA transcript, and we could thereby obtain transgenic plants with late-flowering and albino phenotypes, respectively. Our results provide 'proof of concept' for in planta ABE applications that can lead to induced neo-functionalization or altered mRNA splicing, opening up new avenues for plant genome engineering and biotechnology.

DNA-free genome editing in plants with preassembled CRISPR-Cas9 ribonucleoproteins.

Editing plant genomes without introducing foreign DNA into cells may alleviate regulatory concerns related to genetically modified plants. We transfected preassembled complexes of purified Cas9 protein and guide RNA into plant protoplasts of Arabidopsis thaliana, tobacco, lettuce and rice and achieved targeted mutagenesis in regenerated plants at frequencies of up to 46%. The targeted sites contained germline-transmissible small insertions or deletions that are indistinguishable from naturally occurring genetic variation.