Department of Biotechnology, School of Life Sciences and Technology, Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu, 610054, China.
Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing, 400715, China.
Nat Commun. 2024 Jun 14;15(1):5103. doi: 10.1038/s41467-024-49473-w.
Cytosine base editors (CBEs) and adenine base editors (ABEs) enable precise C-to-T and A-to-G edits. Recently, ABE8e, derived from TadA-8e, enhances A-to-G edits in mammalian cells and plants. Interestingly, TadA-8e can also be evolved to confer C-to-T editing. This study compares engineered CBEs derived from TadA-8e in rice and tomato cells, identifying TadCBEa, TadCBEd, and TadCBEd_V106W as efficient CBEs with high purity and a narrow editing window. A dual base editor, TadDE, promotes simultaneous C-to-T and A-to-G editing. Multiplexed base editing with TadCBEa and TadDE is demonstrated in transgenic rice, with no off-target effects detected by whole genome and transcriptome sequencing, indicating high specificity. Finally, two crop engineering applications using TadDE are shown: introducing herbicide resistance alleles in OsALS and creating synonymous mutations in OsSPL14 to resist OsMIR156-mediated degradation. Together, this study presents TadA-8e derived CBEs and a dual base editor as valuable additions to the plant editing toolbox.
胞嘧啶碱基编辑器（CBEs）和腺嘌呤碱基编辑器（ABEs）可实现精确的 C 到 T 和 A 到 G 编辑。最近，源自 TadA-8e 的 ABE8e 增强了哺乳动物细胞和植物中的 A 到 G 编辑。有趣的是，TadA-8e 也可以进化为 C 到 T 编辑。本研究比较了源自 TadA-8e 的工程化 CBE 在水稻和番茄细胞中的活性，鉴定出 TadCBEa、TadCBEd 和 TadCBEd_V106W 是高效的 CBE，具有高纯度和狭窄的编辑窗口。双碱基编辑器 TadDE 可促进 C 到 T 和 A 到 G 的同时编辑。在转基因水稻中证明了 TadCBEa 和 TadDE 的多重碱基编辑，全基因组和转录组测序未检测到脱靶效应，表明其具有高度特异性。最后，展示了两个使用 TadDE 的作物工程应用：在 OsALS 中引入除草剂抗性等位基因和在 OsSPL14 中创建同义突变以抵抗 OsMIR156 介导的降解。总之，本研究提供了源自 TadA-8e 的 CBE 和双碱基编辑器，为植物编辑工具箱增添了有价值的工具。
