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Sequence-function relationships of the Vitis vinifera L. terpene synthase (VviTPS) family towards understanding the grapevine flower volatilome
Thesis (PhDAgric)--Stellenbosch University, 2020.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2020
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| _version_ | 1867613745256071168 |
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| access_status_str | Open Access |
| author | Smit, Jacobus Samuel |
| author2 | Young, Philip R. |
| author_browse | Smit, Jacobus Samuel Young, Philip R. |
| author_facet | Young, Philip R. Smit, Jacobus Samuel |
| author_sort | Smit, Jacobus Samuel |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhDAgric)--Stellenbosch University, 2020. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/108486 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:41:01.634Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2020 |
| publishDateRange | 2020 |
| publishDateSort | 2020 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/108486 Sequence-function relationships of the Vitis vinifera L. terpene synthase (VviTPS) family towards understanding the grapevine flower volatilome Smit, Jacobus Samuel Young, Philip R. Vivier, Melane A. Stellenbosch University. Faculty of Agrisciences. Dept. of Viticulture and Oenology. Institute for Wine Biotechnology. Terpenes -- Synthesis Grapevine (Vitis vinifera L. Vitaceae) -- Genetics Genomics -- Analysis Grapevine -- Flowers UCTD Thesis (PhDAgric)--Stellenbosch University, 2020. ENGLISH ABSTRACT: Terpenes are ubiquitous to plants and represent the most diverse class of natural products. More than 50 000 terpenes have been described in nature with the enzymes involved in their biosynthesis, namely terpene synthases (TPS), facilitating some of the most complex catalytic activities observed in nature. Terpenes are hydrocarbons that are made of five carbon building blocks. The coupling and prenylation of these building blocks result in different substrates that are characteristic to the biochemical properties of the synthesised terpene. The C10 monoterpene and C15 sesquiterpene compounds are extensively studied due to their volatility. These terpene classes are often associated with the pleasant aromas emitted by flowers, fulfilling important roles as volatile attractants. Terpenes are also known to have strong antimicrobial and insecticidal activities. These metabolites are important defence compounds and are therefore also considered to be specialised metabolites due to the fitness advantage associated with their ecophysiological activities. Grapevine, Vitis vinifera L. (Vitaceae), has one of the largest TPS families, with the majority of these genes involved in mono- and sesquiterpene biosynthesis. These terpene classes are extensively studied for their organoleptic properties in grapes and wine, most often associated with aromatic wines that have floral, Muscat or pepper aromas. The genetic potential of grapevine TPS genes is largely underappreciated seeing that most studies focus on a select few terpene classes that are relevant to wine flavour and aroma. Limited studies have provided some insight into the in planta emission of grapevine terpenes. Grapevine flowers have been identified is a promising organ for terpene biosynthesis due to extensive upregulation of the TPS genes and a concomitant emission of volatile terpenes. Grapevine flowers were therefore characterised for their volatile profiles to identify chemotypic differences. This resulted in the identification of unique chemotypes, with cultivar-specific major sesquiterpene volatiles observed. The genetic factors that contribute to the volatile differences were analysed through functional and computational characterisation. This resulted in functional characterisation of numerous sesquiterpene synthases with aberrant mutations rendering more than half of the isolated genes non-functional. Furthermore, a novel sesquiterpene synthase involved in the unique chemotype of the cultivar Muscat of Alexandria was characterised. This enzyme showed a unique enzyme active site that was linked to the biosynthesis of (E)-β-farnesene. In addition to functional characterisation of genes was the annotation and computational characterisation of the TPS gene families for three diploid grapevine genomes. This allowed for new and fundamentally important insight into how this gene family differs between genotypes. The TPS gene family of grapevine is of great importance from an ecophysiological and economic perspective. By studying the genetic and chemotypic variations in multiple genotypes it was possible to characterise the grapevine TPS landscape. The insights gained from this study provided important fundamental knowledge that furthers our understanding of the complex biochemical and genetic processes involved in grapevine terpene biosynthesis. AFRIKAANSE OPSOMMING: Terpene is alomteenwoordig in plante en word beskou as die mees diverse klas natuurlike produkte. Meer as 50 000 terpene is al beskryf; hul biosintese word gedryf deur terpeen sintases (TPS), 'n groep ensieme wat van die mees komplekse reaksies in die natuur kataliseer. Terpene bestaan uit saamgestelde 5-koolstof (C5) eenhede. Hierdie eenhede word eerstens deur preniel transferases verbind, wat aanleiding gee tot die verlengde kenmerkende substrate vir TPS ensieme. Die 10-koolstof (C10) monoterpene en 15-koolstof (C15) sesquiterpene is baie vlugtig en word dus wyd bestudeer vir hul chemiese rol in plant kommunikasie. Terpene is ook belangrike metaboliete in plant verdediging weens sterk antimikrobiese en insekwerende kenmerke. As gevolg van die funksies word terpene beskou as gespesialiseerde metaboliete weens die natuurlike voordele wat dit tot die plant toevoeg. Druifplante (Vitis vinifera L.) het een van die grootste TPS families (hierna as VviTPS verwys) met die oorhoofse meerderheid betrokke in die vorming van mono- en sesquiterpene. Hierdie klasse van terpene dra by tot die unieke kultivar-spesifieke aromas van sekere wyne, soos bv. blom-, muskaat- of peper aromas wat aanleiding gee dat terpene uit hierdie oogpunt goed bestudeer is. Die volle genetiese potensiaal van VviTPS gene is egter nog grootliks onbekend, aangesien die fokus sover so sterk geval het op slegs die koppelinge met wyn aroma en reuk. Die beperkte hoeveelheid studies wat wel die rolle van terpene in die plantliggaam bestudeer het, sluit die analise van terpeen produksie vanaf wingerd blomme in. Geenuitdrukking en die produksie van vlugtige terpene vanaf die blomme van 'n paar kultivars gee 'n aanduiding dat blom terpeenprofiele kenmerkend kan wees van 'n kultivar. Die meerderheid van terpene wat in wingerdblomme gemeet is val in die sesquiterpeen groep. In hierdie studie was die genetiese en metaboliet verskille in wingerd blomme bestudeer om terpeen biosintese beter te verstaan. VviTPS gene was ge"soleer vanaf menige kultivars en bestudeer om hul funksie te bepaal. Meer as die helfte van die gene was nie funksioneel nie weens mutasies uniek tot 'n kultivar. Verder was 'n unieke geen ge"soleer wat betrokke is by die vorming van (E)-β-farneseen, 'n terpeen wat betrokke is by die unieke blomprofiel van die kultivar Muskat van Aleksandrie. Isolasie en karakterisering van gene was opgevolg met die toepassing van bioinformatika om die VviTPS geen families van drie diplo"ede kultivars te annoteer. Hierdie annotasies was uiters insiggewend en het gelei tot nuwe kennis rakende die VviTPS genetiese verskille tussen kultivar soorte. Die VviTPS familie is van groot belang uit die oogpunt van ekofisiologiese aanpassings van druifplante en ook vir die ekonomiese belang van die terpene ten opsigte van wynaroma. Deur die genetiese en metaboliese verskille in 'n verskeidenheid van kultivars te bestudeer kon die kompleksiteit van die VviTPS familie verder ontrafel word. Hierdie studie voeg dus nuwe kennis tot die wingerd terpeen veld, veral rakende die genetiese, metaboliese en biochemiese prosesse betrokke by terpeen biosintese. Doctoral 2020-02-26T14:18:58Z 2020-04-28T15:15:55Z 2020-02-26T14:18:58Z 2020-04-28T15:15:55Z 2020-04 Thesis http://hdl.handle.net/10019.1/108486 en_ZA Stellenbosch University xii, 99 pages (10 unnumbered pages) : illustrations (some color) application/pdf application/octet-stream Stellenbosch : Stellenbosch University |
| spellingShingle | Terpenes -- Synthesis Grapevine (Vitis vinifera L. Vitaceae) -- Genetics Genomics -- Analysis Grapevine -- Flowers UCTD Smit, Jacobus Samuel Sequence-function relationships of the Vitis vinifera L. terpene synthase (VviTPS) family towards understanding the grapevine flower volatilome |
| title | Sequence-function relationships of the Vitis vinifera L. terpene synthase (VviTPS) family towards understanding the grapevine flower volatilome |
| title_full | Sequence-function relationships of the Vitis vinifera L. terpene synthase (VviTPS) family towards understanding the grapevine flower volatilome |
| title_fullStr | Sequence-function relationships of the Vitis vinifera L. terpene synthase (VviTPS) family towards understanding the grapevine flower volatilome |
| title_full_unstemmed | Sequence-function relationships of the Vitis vinifera L. terpene synthase (VviTPS) family towards understanding the grapevine flower volatilome |
| title_short | Sequence-function relationships of the Vitis vinifera L. terpene synthase (VviTPS) family towards understanding the grapevine flower volatilome |
| title_sort | sequence function relationships of the vitis vinifera l terpene synthase vvitps family towards understanding the grapevine flower volatilome |
| topic | Terpenes -- Synthesis Grapevine (Vitis vinifera L. Vitaceae) -- Genetics Genomics -- Analysis Grapevine -- Flowers UCTD |
| url | http://hdl.handle.net/10019.1/108486 |
| work_keys_str_mv | AT smitjacobussamuel sequencefunctionrelationshipsofthevitisviniferalterpenesynthasevvitpsfamilytowardsunderstandingthegrapevineflowervolatilome |