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

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 <i>OsMSL</i>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 <i>OsMSL</i>s and the trihelix genes from other species divided them into five clusters. <i>OsMSL</i>s from different groups significantly diverged in terms of gene structure and conserved functional domains. However, all <i>OsMSL</i>s contained the same five <i>cis</i>-elements. Some of these were responsive to light and dehydration stress. All <i>OsMSL</i>s expressed in four tissues and six developmental stages of rice but with different expression patterns. Quantitative real-time PCR analysis revealed that the <i>OsMSL</i>s responded to abiotic stresses including drought and high salt stress and stress signal molecule including ABA (abscisic acid), hydrogen peroxide. <i>OsMSL39</i> were simultaneously expressed under all treatments, while <i>OsMSL28</i> showed high expression under hydrogen peroxide, drought, and high salt treatments. Moreover, <i>OsMSL16/27/33</i> displayed significant expression under ABA and drought treatments. Nevertheless, their responses were regulated by light. The expression levels of the 12 chosen <i>OsMSL</i>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.