title: EOBII, a gene encoding a flower-specific regulator of phenylpropanoid volatiles' biosynthesis in petunia.
abstract: Floral scent, which is determined by a complex mixture of low molecular weight volatile molecules, plays a major role in the plant's life cycle. Phenylpropanoid volatiles are the main determinants of floral scent in petunia (Petunia hybrida). A screen using virus-induced gene silencing for regulators of scent production in petunia flowers yielded a novel R2R3-MYB-like regulatory factor of phenylpropanoid volatile biosynthesis, EMISSION OF BENZENOIDS II (EOBII). This factor was localized to the nucleus and its expression was found to be flower specific and temporally and spatially associated with scent production/emission. Suppression of EOBII expression led to significant reduction in the levels of volatiles accumulating in and emitted by flowers, such as benzaldehyde, phenylethyl alcohol, benzylbenzoate, and isoeugenol. Up/downregulation of EOBII affected transcript levels of several biosynthetic floral scent-related genes encoding enzymes from the phenylpropanoid pathway that are directly involved in the production of these volatiles and enzymes from the shikimate pathway that determine substrate availability. Due to its coordinated wide-ranging effect on the production of floral volatiles, and its lack of effect on anthocyanin production, a central regulatory role is proposed for EOBII in the biosynthesis of phenylpropanoid volatiles.
authors.affiliation: The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
authors.forename: Ben
authors.initials: B
authors.lastname: Spitzer-Rimon
authors.forename: Elena
authors.initials: E
authors.lastname: Marhevka
authors.forename: Oren
authors.initials: O
authors.lastname: Barkai
authors.forename: Ira
authors.initials: I
authors.lastname: Marton
authors.forename: Orit
authors.initials: O
authors.lastname: Edelbaum
authors.forename: Tania
authors.initials: T
authors.lastname: Masci
authors.forename: Naveen-Kumar
authors.initials: NK
authors.lastname: Prathapani
authors.forename: Elena
authors.initials: E
authors.lastname: Shklarman
authors.forename: Marianna
authors.initials: M
authors.lastname: Ovadis
authors.forename: Alexander
authors.initials: A
authors.lastname: Vainstein
mesh_terms: D000595:Amino Acid Sequence; D001547:Benzaldehydes / Q000378:metabolism; D001565:Benzoates / Q000378:metabolism; D003001:Cloning, Molecular; D005054:Eugenol / Q000031:analogs & derivatives / Q000378:metabolism; D035264:Flowers / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009812:Odorants; D032306:Petunia / Q000235:genetics* / Q000378:metabolism; D010626:Phenylethyl Alcohol / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018749:RNA, Plant / Q000235:genetics; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014835:Volatilization
chemical_list: D001547:Benzaldehydes; D001565:Benzoates; D010940:Plant Proteins; D018749:RNA, Plant; D014157:Transcription Factors; D005054:Eugenol; C036643:isoeugenol; D010626:Phenylethyl Alcohol; C006723:benzyl benzoate; C032175:benzaldehyde