Huang Yong, Han Zhongmin, Cheng Niannian, Luo Meifang, Bai Xufeng, Xing Yongzhong
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.
Front Plant Sci. 2020 Jan 24;10:1739. doi: 10.3389/fpls.2019.01739. eCollection 2019.
DNA binding with one finger (Dof) proteins are plant-specific transcription factors with important and diverse functions in seed germination, flowering time, and biotic and abiotic stresses. In this study, haplotype-based association analysis was conducted between heading date and 30 family genes in a worldwide germplasm collection. Of these, 22 genes were associated with heading date. Multiple comparisons among haplotypes revealed their diverse functions in promoting and suppressing heading date under short-day (SD) and long-day (LD) conditions. They cumulatively made a considerable contribution to the missing heritability of heading date. A set of knockout mutants of 30 genes generated by CRISPR/Cas9-mediated genome editing technology showed that 11 and 9 genes regulated heading date under LD and SD, respectively. Phenotype measurement of mutants showed that these 11 and 9 genes slightly regulated heading with effects of 2-5 days under LD and SD, respectively. Both mutant and natural variation assays indicated functional redundancy in regulating heading date among family genes. Nucleotide diversity analysis suggested that most genes have been subjected to selection during domestication and improvement. Beyond heading date, this set of mutants is also a good resource for evaluating the function of genes in regulating stress tolerance and seed germination.
单指DNA结合（Dof）蛋白是植物特有的转录因子，在种子萌发、开花时间以及生物和非生物胁迫方面具有重要且多样的功能。在本研究中，对全球种质资源库中的抽穗期与30个家族基因进行了基于单倍型的关联分析。其中，22个基因与抽穗期相关。单倍型之间的多重比较揭示了它们在短日（SD）和长日（LD）条件下对促进和抑制抽穗期的不同功能。它们累计对抽穗期缺失的遗传力做出了相当大的贡献。通过CRISPR/Cas9介导的基因组编辑技术产生的一组30个基因的敲除突变体表明，分别有11个和9个基因在长日和短日条件下调控抽穗期。突变体表型测量表明，这11个和9个基因分别在长日和短日条件下对抽穗期有轻微调控作用，影响为2 - 5天。突变体和自然变异分析均表明家族基因在调控抽穗期方面存在功能冗余。核苷酸多样性分析表明，大多数基因在驯化和改良过程中受到了选择。除了抽穗期，这组突变体也是评估基因在调控胁迫耐受性和种子萌发功能方面的良好资源。
