title: Expression of terpene synthase genes associated with the formation of volatiles in different organs of Vitis vinifera.
abstract: Plants produce a plethora of volatile organic compounds (VOCs) which are important in determining the quality and nutraceutical properties of horticultural food products, including the taste and aroma of wine. Given that some of the most prevalent grape aroma constituents are terpenoids, we investigated the possible variations in the relative expression of terpene synthase (TPS) genes that depend on the organ. We thus analysed mature leaves, young leaves, stems, young stems, roots, rachis, tendrils, peduncles, bud flowers, flowers and berries of cv Moscato bianco in terms of their VOC content and the expression of 23 TPS genes. In terms of the volatile characterization of the organs by SPME/GC-MS analysis, flower buds and open flowers appeared to be clearly distinct from all the other organs analysed in terms of their high VOC concentration. Qualitatively detected VOCs clearly separated all the vegetative organs from flowers and berries, then the roots and rachis from other vegetative organs and flowers from berries, which confirms the specialization in volatile production among different organs. Our real-time RT-PCR results revealed that the majority of TPS genes analysed exhibited detectable transcripts in all the organs investigated, while only some were found to be expressed specifically in one or just a few organs. In most cases, we found that the known products of the in vitro assay of VvTPS enzymes corresponded well to the terpenes found in the organs in which the encoding gene was expressed, as in the case of (E)-β-caryophyllene synthases, α-terpineol synthase and α-farnesene synthase. In addition, we found groups of homologous TPS genes, such as (E)-β-caryophyllene and β-ocimene synthases, expressed distinctively in the various tissues. This thus confirmed the subfunctionalization events and a specialization on the basis of the organs in which they are mostly expressed.
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, I-56124 Pisa, Italy.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Matarese
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, I-56124 Pisa, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Cuzzola
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, I-56124 Pisa, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Scalabrelli
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, I-56124 Pisa, Italy; Nutraceuticals and Food for Health - Nutrafood, University of Pisa, Via del Borghetto 80, I-56124 Pisa, Italy. Electronic address: claudio.donofrio@unipi.it.
authors.forename: Claudio
authors.initials: C
authors.lastname: D'Onofrio
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics* / Q000378:metabolism; D035264:Flowers / Q000378:metabolism; D013729:Terpenes / Q000378:metabolism; D027843:Vitis / Q000201:enzymology*; D055549:Volatile Organic Compounds / Q000032:analysis / Q000378:metabolism
chemical_list: D013729:Terpenes; D055549:Volatile Organic Compounds; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase
keywords: Gene expression; Grapevine; Monoterpenes; Sesquiterpenes; Terpene synthase genes; VOCs; Vitis vinifera