Rapid creation of CENH3‐mediated haploid induction lines using a cytosine base editor (CBE)

• Published in: Plant biology (Stuttgart, Germany) Germany), 2023-01, Vol.25 (1), p.226-230
• Main Authors: Wang, S., Ouyang, K.
• Format: Article
• Language: English
• Subjects: Adenine; Arabidopsis - genetics; Base editor; Breeding; CBE; CENH3; Centromere; Crops, Agricultural - genetics; Cytosine; haploid induction; Haploidy; Histone H3; Histones; Mutagenesis; Mutation; Plant Breeding - methods; Plant species; Plants (botany); Point mutation
• ISSN: 1435-8603; 1438-8677
• DOI: 10.1111/plb.13482

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. Haploid plants can be created by mutating the conserved domain of CENH3 in a cytosine base editor (CBE). This method is less time and effort than the traditional method of obtaining point mutants by EMS.