title: Transcriptome and proteome data reveal candidate genes for pollinator attraction in sexually deceptive orchids.
abstract: BACKGROUND
  Sexually deceptive orchids of the genus Ophrys mimic the mating signals of their pollinator females to attract males as pollinators. This mode of pollination is highly specific and leads to strong reproductive isolation between species. This study aims to identify candidate genes responsible for pollinator attraction and reproductive isolation between three closely related species, O. exaltata, O. sphegodes and O. garganica. Floral traits such as odour, colour and morphology are necessary for successful pollinator attraction. In particular, different odour hydrocarbon profiles have been linked to differences in specific pollinator attraction among these species. Therefore, the identification of genes involved in these traits is important for understanding the molecular basis of pollinator attraction by sexually deceptive orchids.
  
  
  RESULTS
  We have created floral reference transcriptomes and proteomes for these three Ophrys species using a combination of next-generation sequencing (454 and Solexa), Sanger sequencing, and shotgun proteomics (tandem mass spectrometry). In total, 121 917 unique transcripts and 3531 proteins were identified. This represents the first orchid proteome and transcriptome from the orchid subfamily Orchidoideae. Proteome data revealed proteins corresponding to 2644 transcripts and 887 proteins not observed in the transcriptome. Candidate genes for hydrocarbon and anthocyanin biosynthesis were represented by 156 and 61 unique transcripts in 20 and 7 genes classes, respectively. Moreover, transcription factors putatively involved in the regulation of flower odour, colour and morphology were annotated, including Myb, MADS and TCP factors.
  
  
  CONCLUSIONS
  Our comprehensive data set generated by combining transcriptome and proteome technologies allowed identification of candidate genes for pollinator attraction and reproductive isolation among sexually deceptive orchids. This includes genes for hydrocarbon and anthocyanin biosynthesis and regulation, and the development of floral morphology. These data will serve as an invaluable resource for research in orchid floral biology, enabling studies into the molecular mechanisms of pollinator attraction and speciation.
authors.affiliation: Institute of Systematic Botany & Zürich-Basel Plant Science Centre, University of Zurich, Zürich, Switzerland.
authors.forename: Khalid E M
authors.initials: KE
authors.lastname: Sedeek
authors.forename: Weihong
authors.initials: W
authors.lastname: Qi
authors.forename: Monica A
authors.initials: MA
authors.lastname: Schauer
authors.forename: Alok K
authors.initials: AK
authors.lastname: Gupta
authors.forename: Lucy
authors.initials: L
authors.lastname: Poveda
authors.forename: Shuqing
authors.initials: S
authors.lastname: Xu
authors.forename: Zhong-Jian
authors.initials: ZJ
authors.lastname: Liu
authors.forename: Ueli
authors.initials: U
authors.lastname: Grossniklaus
authors.forename: Florian P
authors.initials: FP
authors.lastname: Schiestl
authors.forename: Philipp M
authors.initials: PM
authors.lastname: Schlüter
mesh_terms: D000818:Animals; D000872:Anthocyanins / Q000096:biosynthesis; D053898:Biosynthetic Pathways / Q000235:genetics; D005260:Female; D035264:Flowers / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D009812:Odorants; D029595:Orchidaceae / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D054817:Pollination / Q000235:genetics*; D020543:Proteome / Q000032:analysis*; D040901:Proteomics / Q000379:methods; D060047:Reproductive Isolation; D017422:Sequence Analysis, DNA / Q000379:methods; D012726:Sexual Behavior, Animal; D013045:Species Specificity; D059467:Transcriptome
chemical_list: D000872:Anthocyanins; D010940:Plant Proteins; D020543:Proteome