Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.630117
Title: Investigation of glycosyltransferases from oat
Author: Louveau, Thomas
Awarding Body: University of East Anglia
Current Institution: University of East Anglia
Date of Award: 2013
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Abstract:
Plants produce a diversity of secondary metabolites crucial for their survival into specific ecological niches. Many of these compounds are glycosides generated by the action of family one UDP-dependant glycosyltransferases (UGTs). Glycosylated products of UGTs are known to be essential for reproductive fitness, defence against pathogens, and signalling; UGTs also have a role in the detoxification of xenobiotics. To date, little is known about monocot UGTs compare to their dicot counterparts, despite their potential role in defence and modification of health-promoting component of cereals essential to human diet. This thesis focuses on identification and functional investigation of UGTs expressed in in the diploid oat species Avena strigosa. Chapters 1 and 2 consist of the General Introduction and Material and Methods, respectively. In chapter 3, a systematic analysis of root-expressed UGTs was carried out using transcriptomic and proteomic approaches. A subset of UGTs was then selected for biochemical analysis. Of particular interest were candidates for glycosylation of avenacin, an antimicrobial triterpenoid glycoside that protects oat against fungi infection. In chapter 4, the sugar donor specificity of the recombinant UGTs and their activity towards different triterpenoid acceptors was investigated. In chapter 5, a transient expression system was established in Nicotiana benthamiana in order to investigate UGT activity. Heterologous co-expression of UGTs with early avenacin biosynthetic pathway enzymes leads to biosynthesis of new-to-nature triterpenoid glycosides, so providing a powerful system for functional analysis of terpene glycosylation in planta. In chapter 6, the catalytic properties of the UGT collection towards different plant natural products was investigated, leading to the production of glycosides of interest. The contribution of this study to the understanding of the evolution and function of monocot UGTs and to their potential commercial exploitation is discussed in the chapter 7.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.630117  DOI: Not available
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