title: Evolutionary history of trihelix family and their functional diversification.
abstract: In this study, we carried out an evolutionary, transcriptional, and functional analyses of the trihelix transcription factor family. A total of 319 trihelix members, identified from 11 land plant species, were classified into five clades. The results of phylogeny indicate the binding domains of GT1 and GT2 diverged early in the existence of land plants. Genomic localization revealed that the trihelix family members were highly conserved among cereal species, even though some homeologs generated during the tetraploidy of maize were lost. Three-dimensional structural analyses and an examination of subcellular localization of this family supported the involvement of all five clades in transcriptional regulation. Furthermore, the family members from all clades in sorghum and rice showed a broad and dynamic expression pattern in response to abiotic stresses, indicating regulatory subfunctionalization of their original functions. This finding is further supported by the phenotypes of enhanced tolerance to cold, salt, and drought in transgenic plants overexpressing Sb06g023980 and Sb06g024110. In contrast, few Arobidopsis genes showed inducible expression under abiotic stress conditions, which may indicate a functional shift. Finally, our co-expression analysis points to the involvement of this family in various metabolic processes, implying their further functional divergence.
authors.affiliation: State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, 61 Daizong Street, Tai'an, Shandong 271018, People's Republic of China Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713, Republic of Korea.
authors.forename: Yao
authors.initials: Y
authors.lastname: Qin
authors.affiliation: State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, 61 Daizong Street, Tai'an, Shandong 271018, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, 61 Daizong Street, Tai'an, Shandong 271018, People's Republic of China.
authors.forename: Guanghui
authors.initials: G
authors.lastname: Yu
authors.affiliation: Agronomy College, Sichuan Agricultural University, No. 211, Huiming Road, Wenjiang Region, Chengdu 611130, PR China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, 61 Daizong Street, Tai'an, Shandong 271018, People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, 61 Daizong Street, Tai'an, Shandong 271018, People's Republic of China lkong@sdau.edu.cn kwook@korea.ac.kr wanghongwei@sdau.edu.cn.
authors.forename: Lingrang
authors.initials: L
authors.lastname: Kong
authors.affiliation: Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713, Republic of Korea lkong@sdau.edu.cn kwook@korea.ac.kr wanghongwei@sdau.edu.cn.
authors.forename: Wook
authors.initials: W
authors.lastname: Kim
authors.affiliation: State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, 61 Daizong Street, Tai'an, Shandong 271018, People's Republic of China lkong@sdau.edu.cn kwook@korea.ac.kr wanghongwei@sdau.edu.cn.
authors.forename: Hong Wei
authors.initials: HW
authors.lastname: Wang
mesh_terms: D019143:Evolution, Molecular; D056426:Genetic Loci; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D010944:Plants / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors
keywords: abiotic stress; sorghum; subfunctionalization; trihelix