Table_1_Genome-wide identification of the auxin response factor (ARF) gene family in Magnolia sieboldii and functional analysis of MsARF5.docx

Auxin plays an essential role in flowering, embryonic development, seed dormancy, and germination. Auxin response factors (ARFs) are plant-specific key transcriptional factors in mediating the gene expression network of auxin signaling. Although ARFs in model plants such as Arabidopsis had been well characterized, their identities and potential roles in non-model plants are less studied. Here, we performed genome-wide identification of ARFs in Magnolia sieboldii K. Koch, a primitive species with high taxonomic importance and medicinal values. We found 25 ARF genes in M. sieboldii, which were widely distributed across multiple chromosomes. Based on sequence similarity, the encoded proteins could be either transcriptional repressors or activators. Gene expression analysis showed a dynamic pattern for many ARFs including MsARF5 during seed germination. In addition, overexpressing of MsARF5 showed that it restores many developmental defects in the Arabidopsis mutant. Moreover, two phenotypically distinct transgenic Arabidopsis lines were obtained, indicating a link between gene expression levels and developmental phenotypes. Taken together, we provided a systematic investigation of the ARF gene family in M. sieboldii and revealed an important role of MsARF5 in mediating auxin signaling.

生长素在开花、胚胎发育、种子休眠和萌发过程中扮演着至关重要的角色。生长素响应因子（ARFs）作为植物特异性的关键转录因子，在调节生长素信号通路中的基因表达网络中发挥着中介作用。尽管在拟南芥等模式植物中，ARFs 已得到充分表征，但其在非模式植物中的身份及其潜在作用的研究尚显不足。在本研究中，我们对具有高度分类学重要性和药用价值的原始物种辛夷（Magnolia sieboldii K. Koch）的全基因组进行了 ARFs 的鉴定。我们发现了 M. sieboldii 中的 25 个 ARF 基因，这些基因广泛分布于多个染色体上。基于序列相似性分析，编码的蛋白质可能是转录抑制因子或激活因子。基因表达分析显示，在种子萌发过程中，包括 MsARF5 在内的许多 ARFs 表现出动态的表达模式。此外，MsARF5 的过表达恢复了拟南芥突变体中的许多发育缺陷。此外，我们还获得了两种表型上不同的转基因拟南芥品系，这表明了基因表达水平与发育表型之间的联系。综上所述，我们对 M. sieboldii 中的 ARF 基因家族进行了系统研究，并揭示了 MsARF5 在调节生长素信号通路中的重要作用。