Abstract: Precise replacement of an allele with an elite allele controlling an important agronomic trait in a predefined manner by gene editing technologies is highly desirable in crop improvement. Base editing and prime editing are two newly developed precision gene editing systems which can introduce the substitution of a single base and install the desired short indels to the target loci in the absence of double-strand breaks and donor repair templates, respectively. Since their discoveries, various strategies have been attempted to optimize both base editor (BE) and prime editor (PE) in order to improve the precise editing efficacy, specificity, and expand the targeting scopes. Here, we summarize the latest development of various BEs and PEs, as well as their applications in plants. Based on these progresses, we recommend the appropriate BEs and PEs for both basic plant research and crop improvement. Moreover, we propose the perspectives for further optimization of these two editors. We envision that both BEs and PEs will become the routine and customized precise gene editing tools for both plant biological research and crop improvement in the near future.

Key words: base editing, CRISPR/Cas, plants, precision genome editing, prime editing