Sheng Huangjun, Zhang Han, Deng Hua, Zhang Zuxin, Qiu Fazhan, Yang Fang
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China.
Yazhouwan National Laboratory, Sanya 572024, China.
Plant Cell. 2025 Feb 13;37(2). doi: 10.1093/plcell/koaf029.
Compact plant architecture allows more efficient light capture under higher planting density. Thus, it is a crucial strategy for improving crop yield, particularly in maize (Zea mays L.). Here, we isolated a maize gene, COMPACT PLANT 3 (CT3), regulating plant architecture, using map-based cloning. CT3, encoding a GRAS protein, interacts with an AP2 transcription factor (TF), DWARF AND IRREGULAR LEAF 1 (DIL1). The genetic analysis showed that CT3 and DIL1 regulate leaf angle and plant height via the same pathway, supporting the biological role of their interaction by forming a complex. Transcriptome and DNA profiling analyses revealed that these 2 TFs share many common target genes. We further observed that CT3 functions as a co-regulator to enhance the DNA affinity and transcriptional activity of DIL1. This finding was further supported by the direct binding of DIL1 to 2 cell wall-related genes, ZmEXO1 and ZmXTH14, which were downregulated in the ct3 mutant. Furthermore, ZmEXO1 regulated plant architecture in a manner similar to CT3- and DIL1-mediated regulation. Zmexo1, ct3, and dil1 mutants showed defective cell wall integrity and had reduced cell wall-related components. The introduction of the ct3 or dil1 mutant allele into elite maize hybrids led to a more compact architecture and increased yield under high planting density. Our findings reveal a regulatory pathway of maize plant architecture and provide targets to increase yield under high planting density.
紧凑型株型结构能够在更高种植密度下更高效地捕获光照。因此，这是提高作物产量的关键策略，在玉米（Zea mays L.）中尤为如此。在此，我们利用图位克隆技术分离出一个调控玉米株型结构的基因——紧凑型植株3（CT3）。CT3编码一种GRAS蛋白，它与一个AP2转录因子（TF）——矮化与不规则叶1（DIL1）相互作用。遗传分析表明，CT3和DIL1通过相同途径调控叶角和株高，这支持了它们通过形成复合物相互作用的生物学功能。转录组和DNA谱分析显示，这两个转录因子共享许多共同的靶基因。我们进一步观察到，CT3作为一个共调节因子增强了DIL1的DNA亲和力和转录活性。DIL1直接结合到两个细胞壁相关基因ZmEXO1和ZmXTH14上，这一发现进一步支持了上述结论，且这两个基因在ct3突变体中表达下调。此外，ZmEXO1以类似于CT3和DIL1介导的调控方式调控株型结构。Zmexo1、ct3和dil1突变体表现出细胞壁完整性缺陷，且细胞壁相关成分减少。将ct3或dil1突变等位基因导入优良玉米杂交种中，可使其在高种植密度下具有更紧凑的株型结构并提高产量。我们的研究结果揭示了玉米株型结构的调控途径，并为提高高种植密度下的产量提供了靶点。
