Intein-mediated split SaCas9 for genome editing in plants

Virus-induced genome editing (VIGE) technologies have been developed to address the limitations of plant genome editing, which heavily relies on genetic transformation and regeneration. However, the application of VIGE in plants is hampered by the challenge posed by the size of the commonly used gene-editing nucleases, Cas9 and Cas12a. To address this challenge, our study explores the potential application of inteins in VIGE, internal protein elements known for mediating post-translational protein splicing by self-excising from precursor proteins and ligating adjacent protein sequences. We demonstrate that an intein-mediated split SaCas9 system not only functions effectively in plant genome editing but also achieves efficiency comparable to that of the wild-type SaCas9. Importantly, we have successfully implemented VIGE using this intein-mediated split SaCas9 system in sheepgrass, a Gramineae forage that is notoriously difficult to genetically transform.