Profile

Career

2010-	Professor of Crop Protection	Department of Biology, University of York
2010-	Chief Scientist	The Food and Environment Research Agency
2008-2010	Head of Biological Sciences	Durham University
2003-2008	Professor	Durham University
1998-2003	Reader	Durham University
1991-1998	Lecturer	Durham University
1988-1991	Section Head	Noble Foundation, Ardmore, OK
1986-1988	Group Leader	Schering Agrochemicals, Cambridge
1984-1986	Postdoctoral Research Associate	Royal Holloway
1981-1984	PhD	St. Mary's Hospital Medical School
1977-1981	BSc Biochemistry	Bath University

Research

Overview

The major themes of our research programme are based around the enzymes responsible for the biotransformation of xenobiotics and secondary metabolites in plants to yield products with modified biological activities.  Through the identification and functional characterization of these proteins, our research goals are to understand the integrated biosystem involved in xenobiotic detoxification in plants (the xenome) and establish its associated functions in endogenous metabolism and physiology.  Areas of specialization include determining the role of the xenome in herbicide metabolism and selectivity in crops and weeds and using these enzyme systems for the metabolic engineering of plant and microbial secondary metabolism.

Discoveries

Our group is best known for our classification and functional genomic work with the plant glutathione transferases, which included the discovery of two new classes and the identification of their roles in the metabolism of herbicides in soybean, wheat, maize and of natural products in Arabidopsis.  Most recently we have defined a new role for GSTs in mediating herbicide resistance in black-grass, a major weed of wheat.  Other firsts for our group include the identification and structural elucidation of an N-glucosyltransferase which conjugates aniline pollutants and the isolation of herbicide bioactivating esterase’s in grass weeds and Arabidopsis.  Collectively, these studies have advanced our understanding of the plant xenome and its role in controlling the biological activity of crop protection agents and natural products in both crops and weeds.

Current projects

• The molecular basis of multiple herbicide resistance in grass weeds (Funding bodies: BBSRC and Syngenta - a collaboration with the Chemistry Dept at Durham )
  
• Biosynthesis of high impact flavour and fragrance compounds (Funding bodies: BBSRC, Frutarom)
  
• The C-glycosylation of flavonoids in cereals (Funding body: BBSRC)
  
• Understanding the mode of action of herbicide safeners (Funding body: Syngenta)
  
• Biotransforming phenylpropanoids derived from biorefining: a toolkit approach (Funding body: BBSRC)

Research group(s)

Status	Name	Project
Postdoctoral  Fellow	Melissa Brazier-Hicks	Understanding the mode of action of herbicide safeners
Postdoctoral  Fellow	Hazel Housden	Biotransforming phenylpropanoids derived from biorefining: a toolkit approach
Postdoctoral  Fellow	Federico Sabbadin	The molecular basis of multiple herbicide resistance in grass weeds
Research Student	David Wortley	The role of glutathione transferases in multiple herbicide resistance in grass weeds

Available PhD research projects

Acylation of Natural Products Derived from Biorefining

BBSRC IBTI studentship, Department of Biology, University of York
Available from 2012 for 4 years.
Supervisor : Professor Robert Edwards

The acylation of phytochemicals through esterification is widely encountered in plants and leads to natural products with modified chemical properties and enhanced biological activities.  For example, hydrolysable tannins (natural preservatives), antioxidants such as epigallocatechin gallate (present in tea), acyl-anthocyanins (natural colourants) and drugs such as taxol all bear aromatic acyl groups.  The route of synthesis of these compounds utilises a group of enzymes known as BAHD acyltransferases each of which use CoA esterified donors to acylate acceptor molecules.  As part of a long term study of these reactions, we have recently cloned and expressed acyltransferases which acylate anthocyanins and demonstrated that we can biologically couple this activity with the biological generation of the acyl donors in a ‘one pot’ in vitro synthesis.  Building on these studies, we now propose to construct the acylating pathway in yeast such that we can feed in low value precursors and convert them to higher value specialty acylated products.  Such an approach builds on the approach we have adopted in a related BBSRC biorefining grant of feeding simple aromatics to engineered yeast expressing arabidopsis CoA ligases to generate intermediates for dihydrochalcone synthesis.  We now propose to use the CoA intermediates generated in the core pathway to provide donors for the acylation of anthocyanins and sugars to produce a range of high value preservatives, natural dyes and antioxidants from lower value natural product acceptors. 

The project will be suitable for graduates with a background in biochemistry, microbiology or synthetic chemistry.  A full training in research and related skills will be delivered in the state of the art facilities at York, with the student also engaged in the National IBTI programme in Biorefining.

For further details please contact Robert Edwards at robert.edwards@york.ac.uk or by phone on 07787 266519

Publications

Selected publications

Dixon, D.P. and Edwards, R. (2010) Roles for stress-inducible lambda glutathione transferases in flavonoid metabolism in plants as identified by ligand fishing J. Biol. Chem. doi:10.1074/jbc.M110.164806

Brazier-Hicks, M., Evans, K.M., Gershater, M.C., Puschmann, H., Steel, P.G. and Edwards, R.  (2009) The C-glycosylation of flavonoids in cereals. J. Biol. Chem.  284, 17926-17934.

Brazier-Hicks, M., Evans, K.M. , Cunningham, O.D., Hodgson, D.R.W., Steel, P.G. and Edwards, R . (2008) Catabolism of glutathione conjugates in Arabidopsis thaliana; role in metabolic reactivation of the herbicide safener fenclorim.  J. Biol. Chem.  283, 21102-21112.

Brazier-Hicks, M, Offen, W., Gershater, M.C., Revett, T., Lim, E-K., Bowles, D., Davies, G.J. and Edwards, R (2007) Characterization and engineering of the bifunctional N- and O-glucosyltransferase involved in xenobiotic metabolism in plants.  Proc. Natl. Acad. Sci. (USA).  104, 20238-20243.