SummaryDwarf plant architecture facilitates dense planting, and increased planting densities boost the maize yield. However, breeding applications of dwarfing materials for maize are currently limited. There is an urgent need remove the obstacles to applying dwarf resources. Here, we innovated a new method to add a novel maize dwarf germplasm through the distant hybridization of Maize–Tripsacum–Teosinte allopolyploid (MTP) with maize. We identified ten independent dwarf families with unique characteristics. Five germplasms in our library were controlled by their respective dwarf genes. However, no allele was controlled by Br2. Subsequently, d024 in the library was successfully fine mapped, revealing its linkage to indel‐4 in ZmCYP90D1. The indel‐4 polymorphism regulates the expression of ZmCYP90D1 and is controlled by an upstream transcription factor (ZmBES1/BZR1‐5). The indel‐4 of ZmCYP90D1 allele, which reduces plant height, originated from Tripsacum, a wild variety of maize. However, d024 exhibits sensitivity to brassinosteroids (BRs), with lower castasterone levels in the internodes than that in the wild type. Furthermore, ZmCYP90D1 interacted with ZmFDXs and ZmNAD(P)H to positively regulate the downstream BR synthesis pathway. Additionally, we showed that introgressing the indel‐4 of the Tripsacum allele into modern hybrids ensures yield potential and improves the harvest index under high‐density conditions. Overall, as we begin to manufacture highly engineered dwarf materials using the MTP, this approach will solve the problems faced by corn dwarfs.

中文翻译：

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玉米-Tripsacum-Teosinte异源多倍体（MTP），一种新型玉米矮化突变诱导工具


摘要矮化植物结构有利于密集种植，增加种植密度可提高玉米产量。然而，目前玉米矮化材料的育种应用有限。迫切需要消除矮人资源利用的障碍。在这里，我们创新了一种新方法，通过玉米-Tripsacum-Teosinte异源多倍体（MTP）与玉米的远缘杂交来添加新的玉米矮化种质。我们确定了十个具有独特特征的独立矮人家族。我们文库中的五个种质由各自的矮化基因控制。然而，没有等位基因受 Br2 控制。随后，文库中的 d024 被成功精细定位，揭示了其与 ZmCYP90D1 中 indel-4 的连接。 indel-4 多态性调节 ZmCYP90D1 的表达，并受上游转录因子 (ZmBES1/BZR1-5) 控制。 ZmCYP90D1 等位基因的 indel-4 会降低株高，源自 Tripsacum（一种野生玉米）。然而，d024 对油菜素类固醇 (BR) 表现出敏感性，节间的卡斯特酮水平低于野生型。此外，ZmCYP90D1 与 ZmFDX 和 ZmNAD(P)H 相互作用，正向调节下游 BR 合成途径。此外，我们还表明，将 Tripsacum 等位基因的 indel-4 渗入现代杂交品种可确保产量潜力并提高高密度条件下的收获指数。总的来说，当我们开始使用 MTP 制造高度工程化的矮化材料时，这种方法将解决玉米矮化所面临的问题。