Prime editing in plants: prospects and challenges

Prime editors are reverse transcriptase (RT)-based genome-editing tools that utilize double-strand break (DSB)-free mechanisms to decrease off-target editing in genomes and enhance the efficiency of targeted insertions. The multiple prime editors that have been developed within a short span of time are a testament to the potential of this technique for targeted insertions. This is mainly because of the possibility of generation of all types of mutations including deletions, insertions, transitions, and transversions. Prime editing reverses several bottlenecks of gene editing technologies that limit the biotechnological applicability to produce designer crops. This review evaluates the status and evolution of the prime editing technique in terms of the types of editors available up to prime editor 5 and twin prime editors, and considers the developments in plants in a systematic manner. The various factors affecting prime editing efficiency in plants are discussed in detail, including the effects of temperature, the prime editing guide (peg)RNA, and RT template amongst others. We discuss the current obstructions, key challenges, and available resolutions associated with the technique, and consider future directions and further improvements that are feasible to elevate the efficiency in plants.