*Article* **Genome-Wide Characterization and Identification of Trihelix Transcription Factor and Expression Profiling in Response to Abiotic Stresses in Rice (***Oryza sativa* **L.)**

#### **Jiaming Li <sup>1</sup> , Minghui Zhang <sup>2</sup> , Jian Sun <sup>1</sup> , Xinrui Mao <sup>1</sup> , Jing Wang <sup>3</sup> , Jingguo Wang <sup>1</sup> , Hualong Liu <sup>1</sup> , Hongliang Zheng <sup>1</sup> , Zhen Zhen <sup>2</sup> , Hongwei Zhao <sup>1</sup> and Detang Zou 1,\***


Received: 29 October 2018; Accepted: 6 January 2019; Published: 10 January 2019

**Abstract:** Trihelix transcription factors play a role in plant growth, development and various stress responses. Here, we identified 41 trihelix family genes in the rice genome. These *OsMSL*s (Myb/SANT-LIKE) were located on twelve chromosomes. Synteny analysis indicated only six duplicated gene pairs in the rice trihelix family. Phylogenetic analysis of these *OsMSL*s and the trihelix genes from other species divided them into five clusters. *OsMSL*s from different groups significantly diverged in terms of gene structure and conserved functional domains. However, all *OsMSL*s contained the same five *cis*-elements. Some of these were responsive to light and dehydration stress. All *OsMSL*s expressed in four tissues and six developmental stages of rice but with different expression patterns. Quantitative real-time PCR analysis revealed that the *OsMSL*s responded to abiotic stresses including drought and high salt stress and stress signal molecule including ABA (abscisic acid), hydrogen peroxide. *OsMSL39* were simultaneously expressed under all treatments, while *OsMSL28* showed high expression under hydrogen peroxide, drought, and high salt treatments. Moreover, *OsMSL16/27/33* displayed significant expression under ABA and drought treatments. Nevertheless, their responses were regulated by light. The expression levels of the 12 chosen *OsMSL*s differed between light and dark conditions. In conclusion, our results helped elucidate the biological functions of rice trihelix genes and provided a theoretical basis for further characterizing their biological roles in responding to abiotic stresses.

**Keywords:** rice; trihelix transcription factor; phylogenetic analysis; stress response; light
