*Article* **Genome-Wide Identification and Expression Analysis of Dof Transcription Factors in Lotus (***Nelumbo nucifera* **Gaertn.)**

**Xiaohan Cao 1,†, Wenyang Wan 1,†, Huimin Mao 1, Dandan Yin 1, Xianhui Deng 1, Huan Yan <sup>1</sup> and Liping Ren 1,2,\***


**Abstract:** Lotus (*Nelumbo nucifera* Gaertn.) is a traditional Chinese aquatic flower with high ornamental and economic value, but water salinity seriously affects lotus cultivation and distribution. The Dof transcription factors (TFs) play a crucial function in the regulatory network of growth and defense in plants. However, no systematic investigations of the Dof TFs in lotus have been performed. In this study, comprehensive searches of the lotus genome yielded 29 potential *NnDofs*. We carried out a series of standardized analyses, which include physical properties, multiple sequence alignment, phylogenetic analysis, gene structure, motif composition, cis-acting element prediction, chromosome distribution, and synteny analysis. The results showed that segment duplication probably caused the *NnDofs* gene family expansion. The potential functions of *NnDofs* in lotus development and stress conditions are speculated by promoter analysis. Furthermore, a complete expression investigation of *NnDofs* utilizing an RNA-seq atlas and quantitative real-time polymerase chain reaction (qRT-PCR) was performed. The majority of the *NnDofs* exhibit tissue-specific expression patterns, and many genes have been identified as being extremely sensitive to salt stressors. Overall, this study is the first to report a genome-wide assessment of the Dof family in lotus, and the findings offer vital insights for prospective functional studies on lotus salinity stress.

**Keywords:** *Nelumbo nucifera*; Dof transcription factor; salinity stress
