title: Genome-wide identification and evolutionary analyses of bZIP transcription factors in wheat and its relatives and expression profiles of anther development related TabZIP genes.
abstract: BACKGROUND
  Among the largest and most diverse transcription factor families in plants, basic leucine zipper (bZIP) family participate in regulating various processes, including floral induction and development, stress and hormone signaling, photomorphogenesis, seed maturation and germination, and pathogen defense. Although common wheat (Triticum aestivum L.) is one of the most widely cultivated and consumed food crops in the world, there is no comprehensive analysis of bZIPs in wheat, especially those involved in anther development. Previous studies have demonstrated wheat, T. urartu, Ae. tauschii, barley and Brachypodium are evolutionarily close in Gramineae family, however, the real evolutionary relationship still remains mysterious.
  
  
  RESULTS
  In this study, 187 bZIP family genes were comprehensively identified from current wheat genome. 98, 96 and 107 members of bZIP family were also identified from the genomes of T.urartu, Ae.tauschii and barley, respectively. Orthology analyses suggested 69.4 % of TubZIPs were orthologous to 68.8 % of AetbZIPs and wheat had many more in-paralogs in the bZIP family than its relatives. It was deduced wheat had a closer phylogenetic relationship with barley and Brachypodium than T.urartu and Ae.tauschii. bZIP proteins in wheat, T.urartu and Ae.tauschii were divided into 14 subgroups based on phylogenetic analyses. Using Affymetrix microarray data, 48 differentially expressed TabZIP genes were identified to be related to anther development from comparison between the male sterility line and the restorer line. Genes with close evolutionary relationship tended to share similar gene structures. 15 of 23 selected TabZIP genes contained LTR elements in their promoter regions. Expression of 21 among these 23 TabZIP genes were obviously responsive to low temperature. These 23 TabZIP genes all exhibited distinct tissue-specific expression pattern. Among them, 11 TabZIP genes were predominantly expressed in anther and most of them showed over-dominance expression mode in the cross combination TY806 × BS366.
  
  
  CONCLUSIONS
  The genome-wide identification provided an overall insight of bZIP gene family in wheat and its relatives. The evolutionary relationship of wheat and its relatives was proposed based on orthology analyses. Microarray and expression analyses suggested the potential involvement of bZIP genes in anther development and facilitated selection of anther development related gene for further functional characterization.
authors.affiliation: Beijing Engineering Research Center for Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China. lixueyin2010@163.com.|College of Agronomy, Northwest A & F University, Yangling, 712100, China. lixueyin2010@163.com.
authors.forename: Xueyin
authors.initials: X
authors.lastname: Li
authors.affiliation: Beijing Engineering Research Center for Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China. gshiq@126.com.
authors.forename: Shiqing
authors.initials: S
authors.lastname: Gao
authors.affiliation: Beijing Engineering Research Center for Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China. 744351266@qq.com.
authors.forename: Yimiao
authors.initials: Y
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, College of Life Sciences, Peking University, Beijing, 100871, China. lei.li@pku.edu.cn.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.affiliation: Beijing Engineering Research Center for Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China. zhangfengjieli@163.com.|College of Agriculture, Shanxi Agricultural University, Taigu, 030800, China. zhangfengjieli@163.com.
authors.forename: Fengjie
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Beijing Engineering Research Center for Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China. 641570538@qq.com.|College of Agriculture, Shanxi Agricultural University, Taigu, 030800, China. 641570538@qq.com.
authors.forename: Biane
authors.initials: B
authors.lastname: Feng
authors.affiliation: Beijing Engineering Research Center for Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China. 415599418@qq.com.
authors.forename: Zhaofeng
authors.initials: Z
authors.lastname: Fang
authors.affiliation: College of Agronomy, Northwest A & F University, Yangling, 712100, China. malingjian@nwsuaf.edu.cn.
authors.forename: Lingjian
authors.initials: L
authors.lastname: Ma
authors.affiliation: Beijing Engineering Research Center for Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China. cp_zhao@vip.sohu.com.
authors.forename: Changping
authors.initials: C
authors.lastname: Zhao
mesh_terms: D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics*; D019143:Evolution, Molecular; D035264:Flowers / Q000254:growth & development*; D020869:Gene Expression Profiling; D018745:Genome, Plant / Q000235:genetics; D023281:Genomics; D006823:Hybrid Vigor / Q000235:genetics; D009928:Organ Specificity; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics; D012098:Reproduction; D012689:Sequence Homology, Nucleic Acid; D014908:Triticum / Q000235:genetics* / Q000254:growth & development* / Q000502:physiology
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D010940:Plant Proteins