Peng Lihua, Liu Yangyan, Yang Hongli, Guo Wei, Hao Qingnan, Chen Shuilian, Yuan Songli, Zhang Chanjuan, Yang Zhonglu, Han Bei, Huang Yi, Shan Zhihui, Chen Limiao, Chen Haifeng
Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China.
College of Agriculture, Yangtze University, Jingzhou 434000, China.
Int J Mol Sci. 2025 Aug 11;26(16):7763. doi: 10.3390/ijms26167763.
In a previous study, overexpressing () transgenic soybean plants displayed a semi-dwarfism and compact phenotype, which was regulated by the brassinosteroid (BR) pathway. However, the phenotype of plants could be partly rescued after spraying them with exogenous BR. This indicates that other hormones, in addition to BR, also play a role in regulating the architecture of plants. We observed a significant decrease in the content of endogenous indole-3-acetic acid (IAA) in transgenic soybean lines (OX9 and OX12) compared to wild type (WT) plants. The plant height, leaf area, leaf petiole length, and leaf petiole angle of plants could also be partly rescued after applying exogenous IAA for two weeks. Transcriptome sequencing analysis revealed that the expression of many genes within the Aux/IAA gene family underwent alterations in the transgenic soybean plants. Among them, () showed the highest expression in plants. Furthermore, the results of electrophoretic mobility shift assay and dual-luciferase reporter indicate that GmMYB14 protein could bind to the promoter of . In summary, a decrease in endogenous IAA content may be one of the factors contributing to the compact and dwarfed architecture of plants. GmMYB14 also acts as a transcriptional activator of to potentially block IAA effects. Our findings provide a theoretical basis for further investigation of the regulatory mechanism of GmMYB14 on soybean plant architecture.
在先前的一项研究中，过表达（）的转基因大豆植株表现出半矮化和紧凑的表型，这是由油菜素内酯（BR）途径调控的。然而，在用外源BR喷洒这些植株后，其表型可得到部分恢复。这表明除BR外，其他激素在调控植株的株型方面也发挥作用。我们观察到，与野生型（WT）植株相比，转基因大豆品系（OX9和OX12）中内源吲哚 - 3 - 乙酸（IAA）的含量显著降低。在施加外源IAA两周后，植株的株高、叶面积、叶柄长度和叶柄角度也可得到部分恢复。转录组测序分析表明，Aux/IAA基因家族中的许多基因在转基因大豆植株中的表达发生了改变。其中，（）在植株中的表达最高。此外，电泳迁移率变动分析和双荧光素酶报告基因检测结果表明，GmMYB14蛋白可与的启动子结合。综上所述，内源IAA含量的降低可能是导致植株紧凑和矮化株型的因素之一。GmMYB14还作为的转录激活因子，可能会阻断IAA的作用。我们的研究结果为进一步研究GmMYB14对大豆植株株型的调控机制提供了理论依据。
