title: Molecular cloning and expression analysis of WRKY transcription factor genes in Salvia miltiorrhiza.
abstract: BACKGROUND
  WRKY proteins comprise a large family of transcription factors and play important regulatory roles in plant development and defense response. The WRKY gene family in Salvia miltiorrhiza has not been characterized.
  
  
  RESULTS
  A total of 61 SmWRKYs were cloned from S. miltiorrhiza. Multiple sequence alignment showed that SmWRKYs could be classified into 3 groups and 8 subgroups. Sequence features, the WRKY domain and other motifs of SmWRKYs are largely conserved with Arabidopsis AtWRKYs. Each group of WRKY domains contains characteristic conserved sequences, and group-specific motifs might attribute to functional divergence of WRKYs. A total of 17 pairs of orthologous SmWRKY and AtWRKY genes and 21 pairs of paralogous SmWRKY genes were identified. Maximum likelihood analysis showed that SmWRKYs had undergone strong selective pressure for adaptive evolution. Functional divergence analysis suggested that the SmWRKY subgroup genes and many paralogous SmWRKY gene pairs were divergent in functions. Various critical amino acids contributed to functional divergence among subgroups were detected. Of the 61 SmWRKYs, 22, 13, 4 and 1 were predominantly expressed in roots, stems, leaves, and flowers, respectively. The other 21 were mainly expressed in at least two tissues analyzed. In S. miltiorrhiza roots treated with MeJA, significant changes of gene expression were observed for 49 SmWRKYs, of which 26 were up-regulated, 18 were down-regulated, while the other 5 were either up-regulated or down-regulated at different time-points of treatment. Analysis of published RNA-seq data showed that 42 of the 61 identified SmWRKYs were yeast extract and Ag(+)-responsive. Through a systematic analysis, SmWRKYs potentially involved in tanshinone biosynthesis were predicted.
  
  
  CONCLUSIONS
  These results provide insights into functional conservation and diversification of SmWRKYs and are useful information for further elucidating SmWRKY functions.
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, No.151, Malianwa North Road, Haidian District, Beijing, 100193, China. licaili390@163.com.
authors.forename: Caili
authors.initials: C
authors.lastname: Li
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, No.151, Malianwa North Road, Haidian District, Beijing, 100193, China. butterfly_qiao@163.com.
authors.forename: Dongqiao
authors.initials: D
authors.lastname: Li
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, No.151, Malianwa North Road, Haidian District, Beijing, 100193, China. sfjstar@126.com.
authors.forename: Fenjuan
authors.initials: F
authors.lastname: Shao
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, No.151, Malianwa North Road, Haidian District, Beijing, 100193, China. sflu@implad.ac.cn.
authors.forename: Shanfa
authors.initials: S
authors.lastname: Lu
mesh_terms: D000085:Acetates / Q000494:pharmacology; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000145:classification / Q000378:metabolism*; D003001:Cloning, Molecular; D003517:Cyclopentanes / Q000494:pharmacology; D035264:Flowers / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D008969:Molecular Sequence Data; D054883:Oxylipins / Q000494:pharmacology; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D027561:Salvia miltiorrhiza / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D012834:Silver / Q000494:pharmacology; D014157:Transcription Factors / Q000737:chemistry / Q000145:classification / Q000378:metabolism*
chemical_list: D000085:Acetates; D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; D014157:Transcription Factors; D012834:Silver; C072239:methyl jasmonate