title: Genome-wide identification and characterisation of R2R3-MYB genes in sugar beet (Beta vulgaris).
abstract: BACKGROUND
  The R2R3-MYB genes comprise one of the largest transcription factor gene families in plants, playing regulatory roles in plant-specific developmental processes, metabolite accumulation and defense responses. Although genome-wide analysis of this gene family has been carried out in some species, the R2R3-MYB genes in Beta vulgaris ssp. vulgaris (sugar beet) as the first sequenced member of the order Caryophyllales, have not been analysed heretofore.
  
  
  RESULTS
  We present a comprehensive, genome-wide analysis of the MYB genes from Beta vulgaris ssp. vulgaris (sugar beet) which is the first species of the order Caryophyllales with a sequenced genome. A total of 70 R2R3-MYB genes as well as genes encoding three other classes of MYB proteins containing multiple MYB repeats were identified and characterised with respect to structure and chromosomal organisation. Also, organ specific expression patterns were determined from RNA-seq data. The R2R3-MYB genes were functionally categorised which led to the identification of a sugar beet-specific clade with an atypical amino acid composition in the R3 domain, putatively encoding betalain regulators. The functional classification was verified by experimental confirmation of the prediction that the R2R3-MYB gene Bv_iogq encodes a flavonol regulator.
  
  
  CONCLUSIONS
  This study provides the first step towards cloning and functional dissection of the role of MYB transcription factor genes in the nutritionally and evolutionarily interesting species B. vulgaris. In addition, it describes the flavonol regulator BvMYB12, being the first sugar beet R2R3-MYB with an experimentally proven function.
authors.forename: Ralf
authors.initials: R
authors.lastname: Stracke
authors.forename: Daniela
authors.initials: D
authors.lastname: Holtgräwe
authors.forename: Jessica
authors.initials: J
authors.lastname: Schneider
authors.forename: Boas
authors.initials: B
authors.lastname: Pucker
authors.forename: Thomas Rosleff
authors.initials: TR
authors.lastname: Sörensen
authors.forename: Bernd
authors.initials: B
authors.lastname: Weisshaar
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D027461:Beta vulgaris / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D044948:Flavonols / Q000378:metabolism; D018745:Genome, Plant / Q000235:genetics*; D008969:Molecular Sequence Data; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D044948:Flavonols; D010940:Plant Proteins; D014157:Transcription Factors