单碱基编辑可通过创制优异单核苷酸突变加快作物遗传改良，是备受关注的生物育种技术。要实现其育种生产应用，必须提升技术的安全性。为解决常规单碱基编辑方式易脱靶且带来外源DNA整合及组织培养出现未知突变潜在风险的难题，研究拟以递送系统为重心，研发高效、精准新型A3A-CBE和ABE单碱基编辑器，建立其核糖核蛋白复合体RNP递送系统，进而与优化出的顶端分生组织SAM原位转化系统结合，整合成新型A3A-CBE和ABE的RNP-SAM递送转化系统。通过对RNP-SAM递送转化系统在SAM及整株植物中编辑效应的系统分析，综合建立安全、精准、高效的小麦无组织培养DNA-free单碱基编辑技术，实现技术安全性的提升。同时利用新技术创制TaCslF6的优异单核苷酸突变，培育生物安全的高可溶性β-葡聚糖小麦新种质。研究将为单碱基编辑育种提供创新技术和和优异种质，对推进基因组编辑育种产业化进程具有重要意义。

Base editing technology, improved crop improvements by introducing expected single nucleotide variation in modern varieties, is a highly expected innovative crop breeding method. However, current applications of base editing in plants rely on delivering plasmid DNAs of base editors into plant cell and then obtaining the mutants through tissue-culture. These possibilities of foreign DNA integration, off-target effects and unknown mutations in tissue culture procedure have limits in adopting base editing technology in precision crop breeding. Therefore, the reduction of off-target mutations, avoidance of transgene integration and tissue-culture dependence are the most important targets for optimization. In this project, we plan to solve these problems through the innovation of delivery system. We will develop novel efficient and precise base editors of A3A-CBE and ABE. These novel base editors will be optimized to establish their ribonucleoprotein complexes (RNPs) delivery systems. Then these RNP delivery systems will be combined with the Shoot apical meristems (SAMs) mediated in planta transformation procedure. The RNP-SAM delivery-in planta editing system will be tested in edited SAM and in mutant plants. We will establish in planta DNA-free base editing technologies which can efficiently realize precise single nucleotide substitution in wheat. We will further apply these optimized technologies to generate nucleotide mutation of valuable targets in a highly expressing TaCslF6 wheat material for high soluble beta-glucan breeding in wheat. Through this study, we expect to not only establish in planta DNA-free base editing technologies but also obtain some elite germplasm with high soluble beta-glucan for wheat breeding. Our works are helpful for the application of base editing technology in precision breeding and make the commercialization of genome edited crops more accessible over the globe.