Abstract The DNA-binding one Zinc Finger (Dof) protein is an important transcription factor unique in plants, which plays important roles in regulating plant biological rhythm, flowering and nitrogenium storage. In this study, the MtDof32 gene was isolated from Medicago truncatula and the gene function was characterized in trangenic plants. The expression pattern exhibited that MtDof32 gene might be involved in stress responses and tolerances. Transgenic Arabidopsis thaliana plants were obtained by agrobacterium tumefaciens-mediated transformation. Compared with wild-type plants, the MtDof32 transgenic Arabidopsis showed reduced total branch number by 40% on average, and increased rosettes number, the number gap was growing with plant growth. These phenotypes have never been found in previous studies. In addition, transgenic plants also showed delayed flowering, enlarged flower and leaf organs, and enhanced tolerances to osmotic and salt stresses. The expression level of some branching and flowering regulation genes in transgenic plants changed significantly, compared to those of wild-type plants. Taken together, these results demonstrated novel functions of MtDof32 in reducing branch number and increasing rosettes number, which is beneficial for further studies about the plant growth and development regulation network mediated by Dof protein family.

中文翻译：

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蒺藜苜蓿 MtDof32 转录因子的表达调控植物生长并增强转基因拟南芥的非生物胁迫耐受性

摘要 DNA结合锌指(Dof)蛋白是植物特有的一种重要转录因子，在调节植物生物节律、开花和氮素储存等方面具有重要作用。在这项研究中，MtDof32 基因是从蒺藜苜蓿中分离出来的，并在转基因植物中表征了该基因的功能。表达模式表明 MtDof32 基因可能参与应激反应和耐受性。通过根癌农杆菌介导的转化获得转基因拟南芥植物。与野生型植物相比，MtDof32转基因拟南芥的总分枝数平均减少了40%，玫瑰花结数增加，数量差距随着植株的生长而增大。这些表型在以前的研究中从未发现过。此外，转基因植物还表现出开花延迟、花和叶器官增大以及对渗透和盐胁迫的耐受性增强。与野生型植物相比，转基因植物中一些分枝和开花调控基因的表达水平发生了显着变化。综上所述，这些结果证明了 MtDof32 在减少分枝数和增加莲座丛数方面的新功能，有利于进一步研究由 Dof 蛋白家族介导的植物生长发育调控网络。