Plant base editing: a decade of progress and future applications

Base editors derived from clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) systems are widely used for genomic studies in both plants and animals. The broad applicability and safety of base-editing approaches have garnered considerable attention from the research community, and there could be ways to further enhance targeting efficiency and target window range. However, the complex classification and diverse functionalities of base editors pose challenges to their effective utilization and improvement. In this review, we discuss technical principles characterizing various types of base editors, including cytosine base editors (CBEs), adenine base editors (ABEs), dual base editors (DBEs), thymine base editors (TBEs), and guanine base editors (GBEs), among others, which employ distinct mechanisms and DNA repair pathways. We also describe current optimization strategies to assist researchers in improving the deployment of these tools under specific conditions. Finally, we comprehensively analyze the practical applications and advantages of base editors, offering a clear view of their development, their previous and potential applications, and how to select the appropriate tools for specific purposes.