Abstract：
Prime editing is a versatile CRISPR/Cas-based precise genome-editing technique for crop breeding. Four new types of prime editors (PEs) named PE6a-d were recently generated using evolved and engineered reverse transcriptase (RT) variants from three different sources. In this study, we tested the editing efficiencies of four PE6 variants and two additional PE6 constructs with double-RT modules in transgenic rice (Oryza sativa) plants. PE6c, with an evolved and engineered RT variant from the yeast Tf1 retrotransposon, yielded the highest prime-editing efficiency. The average fold change in the editing efficiency of PE6c compared with PEmax exceeded 3.5 across 18 agronomically important target sites from 15 genes. We also demonstrated the feasibility of using two RT modules to improve prime-editing efficiency. Our results suggest that PE6c or its derivatives would be an excellent choice for prime editing in monocot plants. In addition, our findings have laid a foundation for prime-editing-based breeding of rice varieties with enhanced agronomically important traits.
摘要：
Prime编辑是一种通用的基于CRISPR/Cas的精确基因组编辑技术，用于作物育种。最近使用来自三种不同来源的进化和工程化逆转录酶（RT）变体产生了四种新类型的名为PE6a-d的主编辑（PE）。在这项研究中,我们在转基因水稻（Oryzasativa）植物中测试了四种PE6变体和另外两种具有双RT模块的PE6构建体的编辑效率。PE6c,具有来自酵母Tf1逆转录转座子的进化和工程改造的RT变体，产生了最高的主编辑效率。与PEmax相比，PE6c编辑效率的平均倍数变化超过3.5，来自15个基因的18个农学上重要的靶位点。我们还证明了使用两个RT模块来提高原始编辑效率的可行性。我们的结果表明，PE6c或其衍生物将是单子叶植物初等编辑的绝佳选择。此外,我们的发现为基于主要编辑的具有增强的农艺重要性状的水稻品种育种奠定了基础。
