State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.
Hainan Yazhou Bay Seed Lab, Sanya, 572024, Hainan, China.
Theor Appl Genet. 2024 May 11;137(6):128. doi: 10.1007/s00122-024-04636-7.
Discovery of Rht27, a dwarf gene in wheat, showed potential in enhancing grain yield by reducing plant height. Plant height plays a crucial role in crop architecture and grain yield, and semi-dwarf Reduced Height (Rht) alleles contribute to lodging resistance and were important in "Green Revolution." However, the use of these alleles is associated with some negative side effects in some environments, such as reduced coleoptile length, low nitrogen use efficiency, and reduced yield. Therefore, novel dwarf gene resources are needed to pave an alternative route to overcome these side effects. In this study, a super-dwarf mutant rht27 was obtained by the mutagenesis of G1812 (Triticum urartu, the progenitor of the A sub-genome of common wheat). Genetic analysis revealed that the dwarf phenotype was regulated by a single recessive genetic factor. The candidate region for Rht27 was narrowed to a 1.55 Mb region on chromosome 3, within which we found two potential candidate genes that showed polymorphisms between the mutant and non-mutagenized G1812. Furthermore, the natural variants and elite haplotypes of the two candidates were investigated in a natural population of common wheat. The results showed that the natural variants affect grain yield components, and the dwarf haplotypes show the potential in improving agronomic traits and grain yield. Although the mutation in Rht27 results in severe dwarf phenotype in T. urartu, the natural variants in common wheat showed desirable phenotype, which suggests that Rht27 has the potential to improve wheat yield by utilizing its weak allelic mutation or fine-tuning its expression level.
矮秆基因 Rht27 的发现为降低株高、提高小麦产量提供了可能。株高在作物结构和产量形成中起着关键作用，半矮秆 Reduced Height (Rht) 等位基因有助于抗倒伏，在“绿色革命”中发挥了重要作用。然而，这些等位基因的应用在某些环境中存在一些负面影响，如降低胚芽鞘长度、降低氮素利用效率和降低产量。因此，需要新的矮秆基因资源来开辟一条克服这些副作用的替代途径。本研究通过对 G1812（普通小麦 A 基因组的祖先）的诱变获得了一个超矮秆突变体 rht27。遗传分析表明，矮秆表型受单个隐性遗传因子调控。Rht27 的候选区域被缩小到 3 号染色体上的 1.55 Mb 区域，在该区域内我们发现了两个潜在的候选基因，它们在突变体和未诱变的 G1812 之间表现出多态性。此外，还在普通小麦自然群体中研究了这两个候选基因的自然变异和优良单倍型。结果表明，自然变异影响粒重组成，矮秆单倍型在提高农艺性状和粒重方面具有潜力。虽然 Rht27 突变在 T. urartu 中导致严重的矮秆表型，但普通小麦中的自然变异表现出理想的表型，这表明 Rht27 具有通过利用其弱等位基因突变或精细调节其表达水平来提高小麦产量的潜力。
