DataSheet_1_Genome-wide identification of the auxin response factor (ARF) gene family in Magnolia sieboldii and functional analysis of MsARF5.pdf

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、种子休眠及萌发等过程中发挥着至关重要的作用。生长素反应因子（ARFs）作为植物特有的关键转录因子，在介导生长素信号通路的基因表达网络中扮演着核心角色。尽管在拟南芥等模式植物中，ARFs已得到充分研究，但其身份及其在非模式植物中的潜在作用尚待深入探讨。本研究中，我们对具有高分类学重要性及药用价值的原始物种辛夷（Magnolia sieboldii K. Koch）进行了全基因组ARFs的鉴定。在辛夷中，我们发现了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，编码的蛋白可能为转录抑制因子或激活因子。基因表达分析表明，包括MsARF5在内的许多ARFs在种子萌发过程中表现出动态表达模式。此外，MsARF5的过表达实验表明，它能够恢复拟南芥突变体中的许多发育缺陷。进一步地，我们获得了两种表型上明显不同的转基因拟南芥株系，这表明基因表达水平与发育表型之间存在联系。综合以上研究，我们对辛夷中的ARF基因家族进行了系统性的研究，并揭示了MsARF5在介导生长素信号通路中的重要作用。