Li Di, Miao Tianle, Liao Hong, Zhong Yongjia
Root Biology Center, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Int J Mol Sci. 2025 May 9;26(10):4547. doi: 10.3390/ijms26104547.
Auxin is the most important phytohormone, regulating root growth and development in plants. ARFs function as central regulators in auxin signaling in model plants, and the functions of ARF activators have been widely investigated, while the functions of ARF repressors remain elusive. In this study, we investigated the family of in soybean through a genome-wide expression pattern and functional study of roots highly expressing . In total, we identified 59 members in the soybean genome. GmARFs harbor canonical B3 DNA-binding (B3), ARF (Aux rep), and PB1 functional protein domains. We identified two potential repressor genes, () and (), which are specifically or highly expressed in the roots. Histochemical staining suggested that both genes are primarily expressed in the stele, root tips, and lateral root primordia. Subcellular localization analysis showed they were mainly localized in the nucleus. Overexpression of and significantly inhibited root growth using a transgenic hairy root assay. Root section analysis further suggested that and negatively regulated cortical cell layers and the longitudinal cell length of roots, thereby modulating root growth. Overall, this study has preliminarily identified two that inhibit root growth in soybean. This discovery has deepened our understanding of the functions of ARFs in root development and has provided guidance for breeding crop roots with improved nutrient use efficiency.
生长素是最重要的植物激素，调控植物根系的生长发育。在模式植物中，生长素响应因子（ARFs）作为生长素信号传导的核心调节因子，ARF激活因子的功能已得到广泛研究，而ARF抑制因子的功能仍不清楚。在本研究中，我们通过对高表达[具体基因名称未给出]的根系进行全基因组表达模式和功能研究，对大豆中的[该基因家族名称未给出]家族进行了研究。我们总共在大豆基因组中鉴定出59个[该基因家族名称未给出]成员。大豆ARFs含有典型的B3 DNA结合结构域（B3）、ARF结构域（Aux rep）和PB1功能蛋白结构域。我们鉴定出两个潜在的抑制因子基因，[基因1名称未给出]（[基因1缩写未给出]）和[基因2名称未给出]（[基因2缩写未给出]），它们在根中特异性表达或高表达。组织化学染色表明，这两个基因主要在中柱、根尖和侧根原基中表达。亚细胞定位分析表明它们主要定位于细胞核。利用转基因毛状根试验，[基因1名称未给出]和[基因2名称未给出]的过表达显著抑制了根的生长。根段分析进一步表明，[基因1名称未给出]和[基因2名称未给出]负调控根的皮层细胞层数和纵向细胞长度，从而调节根的生长。总体而言，本研究初步鉴定出两个抑制大豆根生长的[该基因家族名称未给出]。这一发现加深了我们对ARFs在根发育中功能的理解，并为培育养分利用效率提高的作物根系提供了指导。
