Prime editing efficiently generates W542L and S621I double mutations in two ALS genes in maize

A novel and universal CRISPR/Cas-derived precision genome-editing technology named prime editing was developed. However, low efficiency of prime editing was shown in transgenic rice lines. We reasoned that enhancing pegRNA expression would improve prime-editing efficiency. In this report, we describe two strategies for enhancing pegRNA expression. We constructed a prime-editing vector harboring two pegRNA variants for W542L and S621I double mutations in ZmALS1 and ZmALS2. Compared with previous reports in rice, we achieved much higher prime-editing efficiency in maize. Our results are inspiring and provide a direction for the optimization of plant prime editors.