*Article* **Genome-Wide Screening and Characterization of the** *Dof* **Gene Family in Physic Nut (***Jatropha curcas* **L.)**

#### **Peipei Wang 1,2, Jing Li <sup>1</sup> , Xiaoyang Gao <sup>1</sup> , Di Zhang 1,2, Anlin Li 1,2 and Changning Liu 1,\***


Received: 12 April 2018; Accepted: 23 May 2018; Published: 29 May 2018

**Abstract:** Physic nut (*Jatropha curcas* L.) is a species of flowering plant with great potential for biofuel production and as an emerging model organism for functional genomic analysis, particularly in the Euphorbiaceae family. DNA binding with one finger (Dof) transcription factors play critical roles in numerous biological processes in plants. Nevertheless, the knowledge about members, and the evolutionary and functional characteristics of the *Dof* gene family in physic nut is insufficient. Therefore, we performed a genome-wide screening and characterization of the *Dof* gene family within the physic nut draft genome. In total, 24 *JcDof* genes (encoding 33 JcDof proteins) were identified. All the *JcDof* genes were divided into three major groups based on phylogenetic inference, which was further validated by the subsequent gene structure and motif analysis. Genome comparison revealed that segmental duplication may have played crucial roles in the expansion of the *JcDof* gene family, and gene expansion was mainly subjected to positive selection. The expression profile demonstrated the broad involvement of *JcDof* genes in response to various abiotic stresses, hormonal treatments and functional divergence. This study provides valuable information for better understanding the evolution of *JcDof* genes, and lays a foundation for future functional exploration of *JcDof* genes.

**Keywords:** *Jatropha curcas*;*Dof* gene family; transcription factor; phylogenetic analysis; gene expression analysis
