Wang S, Ouyang K
Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang, China.
Key Laboratory of Genetics, Breeding, and Multiple Utilization of Crops, Ministry of Education, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China.
Plant Biol (Stuttg). 2023 Jan;25(1):226-230. doi: 10.1111/plb.13482. Epub 2022 Nov 10.
Haploid induction (HI) can create true-breeding lines in a single generation, which can significantly accelerates the breeding process. In recent years, scientists have developed a variety of new techniques to induce haploids through manipulation of CENH3, a variant of the centromere-specific histone H3. One alternative approach is based on CENH3 point mutations derived from EMS/TILLING, which is not lethal and yet is responsible for inducing haploids. However, most residues have been obtained by EMS mutagenesis over a long period of time. Recently, a new approach called 'base editing' was developed for plants. Here, we report a new method that uses a cytosine base editor (CBE) to create a point mutation of CENH3 as a haploid induction line, which substitutes adenine (A) for guanine (G). As proof of the extreme simplicity of this approach to create haploid-induced lines, we identified an L130F substitution within the histone fold domain in Arabidopsis thaliana. Subsequently, we tested the haploid-inducing potential of homozygous L130F plants by pollinating them with Col-0, and obtained 2.9% paternal haploid plants. In brief, our innovative technology provides a new perspective for the promotion of CENH3-mediated haploid induction in crops, and also provides a variety of options for breeders. Such conserved point mutations as L130F could be developed into a general instrument for haploid induction in a wide range of plant species. Extending these systems would represent a major advance over haploid production.
单倍体诱导（HI）能够在一代内创建纯合品系，这可显著加速育种进程。近年来，科学家们已开发出多种新技术，通过操纵着丝粒特异性组蛋白H3的变体CENH3来诱导单倍体。一种替代方法基于源自EMS/TILLING的CENH3点突变，该突变不具有致死性但可诱导单倍体。然而，大多数残基是通过长时间的EMS诱变获得的。最近，一种名为“碱基编辑”的新方法被开发用于植物。在此，我们报告一种新方法，该方法使用胞嘧啶碱基编辑器（CBE）创建作为单倍体诱导系的CENH3点突变，即将腺嘌呤（A）替换为鸟嘌呤（G）。为证明这种创建单倍体诱导系方法的极端简易性，我们在拟南芥的组蛋白折叠域内鉴定出一个L130F替换。随后，我们通过用Col-0给纯合L130F植株授粉来测试其单倍体诱导潜力，并获得了2.9%的父本单倍体植株。简而言之，我们的创新技术为促进作物中CENH3介导的单倍体诱导提供了新视角，也为育种者提供了多种选择。诸如L130F这样的保守点突变可被开发成广泛植物物种单倍体诱导的通用工具。扩展这些系统将代表单倍体生产方面的一项重大进展。
