Arabidopsis thaliana methylated cytosine editing

Cytosine base editors (CBEs) can generate C-to-T editing, but presently used CBEs in plants are inefficient in editing methylated cytosines (mCs) and several cytosines can be simultaneously edited when multiple cytosines exist. By screening a series of cytidine deaminases, we show that a fusion protein composed of xCas9 nickase and human APOBEC3B C-terminal domain (A3Bctd-CBE) can perform efficient mC- and C-to-T conversions at a single cytosine level in Arabidopsis thaliana.