Email: memes@uoguelph.ca
Office: SCIE 4482
Ext: 56102
Lab: SCIE 4409-10
Ext: 58852
Profile
Having graduated with a degree in Biochemistry from the University of Sheffield (the department in which Krebs delineated the citric acid cycle) my interests in plants really began during my PhD studies. In the same Biochemistry Department I became interested in the regulation of plant metabolism, where I focused on carbon-nitrogen interactions in roots. These interests led me to a post-doctoral period as a research fellow in the Institute of Plant Physiology , at the University of Bern, Switzerland where I followed the same theme, but in relation to photorespiration in leaves. In 1981, I was fortunate to be appointed to a Faculty position in the Department of Botany at the University of Manchester UK . The next 21 years saw a period of great change as we established the largest unified School of Biological Sciences in the UK , where I became Dean of Research. I moved to Guelph in the Summer of 2002 as Dean of the College of Biological Science and have re-established my research laboratories here where our main focus is the regulation of plant carbohydrate metabolism.
I an currently President of the Canadian Council of Deans of Science (CCDS) and serve on the Provincial Early Researchers Awards panel and the ORF-Research Excellence panel. I am Associate Editor of the Journal of Experimental Botany.
Prior to moving to Canada , I served on several grant-awarding committees of the UK Biotechnology and Biological Sciences Research Council (BBSRC) and was the national coordinator of a 5 year programme involving 20 laboratories studying the Regulation of Plant Metabolism. I was also the coordinator for a major EU project studying starch synthesis in wheat, which involved laboratories in five countries. I was also a member of the Boards of Governors for two of the premier UK plant science research institutes, The John Innes Centre and the Scottish Crops Research Institute.
Education
PhD -- University of Sheffield
Postdoctoral Research Fellow, Institute of Plant Physiology, at the University of Bern, Switzerland
Research
Research in the laboratory is focused on understanding how plant metabolism is regulated, particularly in relation to carbohydrate metabolism. Much of our current effort is focused on understanding the regulation of starch synthesis in storage issues such as the developing seeds of cereals and also in tubers. Starch is the major determinant of yield in such crops, and has wide application in both the food and non-food industries, yet there remain a huge number of unknowns in what limits the production of this glucan polymer. Many of our studies have emanated from the investigation of amyloplasts, the organelles in which starch is made. The type of questions we are addressing include: what form of carbohydrate enters the amyloplast to support starch synthesis? How does this transport contribute to the regulation of starch production and whether amylose or amylopectin (the glucan polymers which form starch) are synthesized? What biochemical mechanisms serve to regulate the enzymes of starch synthesis within amyloplasts? We are actively investigating the role of post-translational modification (protein phosphorylation) in relation to the latter question, and have recently discovered the existence of multi-enzyme complexes comprising different enzymes involved in making starch. The techniques we use to address these questions include proteomic technologies such as mass spectrometry, and bioinformatics as well as protein isolation and organelle purification coupled with genetic modification. Our research covers cereals such as maize and wheat as well as model organisms like Arabidopsis thaliana.
We also study the role of the oxidative pentose phosphate pathway which contributes intermediates to a number of primary and secondary metabolic pathways in plants including nitrogen assimilation, oxidative stress, fatty acid synthesis and phenolic metabolism. Recently, using transgenic plants we have found that altering the flux of carbon through this pathway has significant effects on the ability of leaves to withstand oxidative stress as well as changing the pattern of carbon partitioning into end products.
During my career I have been fortunate to have had more than 20 research students and 15 post-doctoral research assistants work with me, and we have had a regular stream of international visitors with whom we collaborate actively. Many of the students and post-docs have gone on to establish outstanding scientific careers in universities, industry and commerce and been recognized through the awards of prestigious fellowships and by learned societies.
Our aim is to understand the fundamental processes involved in regulating key aspects of plant metabolism, and integrate the biochemistry, molecular biology and physiology into a whole plant context. We have an extensive network of ongoing collaborations, involving laboratories in Australia , Egypt, Germany , France , Italy , Spain , the United Kingdom and the United States as well as within Canada .
I work very closely with Dr Ian Tetlow, a faculty member in the same department. We are currently actively searching for graduate students and postdoctoral assistants to join us on grants awarded by NSERC and OMAFRA.
Selected Publications (2003-2009)
Chapters and Reviews
I.J. Tetlow, S. Rawsthorne, C. Raines and M.J. Emes (2004) Plastid Metabolic Pathways. (Editor, S. Moller) Annual Plant Reviews 60 – 125
I.J. Tetlow, M.K. Morrell and M.J. Emes (2004) Recent developments in understanding the regulation of starch metabolism in higher plants. J. Exp. Bot. 55, 2131-2145 [NSERC]
Research Papers
- F. Liu, A. Makhmoudova, E.A.Lee, R. Wait, M.J.Emes and I.J. Tetlow (2009) The amylose extender mutant of maize conditions novel protein-protein interactions between starch biosynthetic enzymes in amyloplasts.
J. Exp. Bot 60, 4423-4440
[This paper demonstrates that in a high amylose mutant of maize, lacking Branching Enzyme IIb, novel stromal protein complexes are formed between starch biosynthetic enzymes which become incorporated into starch granules and contribute to the altered starch phenotype]. - I.J. Tetlow, K.G. Beisel, S. Cameron, A. Makhmoudova, F. Liu, N.S. Bresolin, R. Wait, M.K. Morell, and M.J. Emes (2008) Analysis of Protein Complexes in Wheat Amyloplasts Reveals Functional Interactions among Starch Biosynthetic Enzymes.
Plant Physiology 146, 1878-1891
[This paper is the first to demonstrate that soluble starch synthases and branching enzymes found in the stroma of amyloplasts form functional protein complexes. The association of SSI, SSII and BEIIa was shown to be phosphorylation dependent. These complexes of soluble proteins are reflected in their subsequent entrapment within the starch granule]. - T.A. Hennen-Bierwagen, F. Liu, R.S. Marsh, S. Kim, Q. Gan, I.J. Tetlow, M.J. Emes, M.G. James and A.M. Myers (2008) Multiple Starch Biosynthetic Enzymes from Developing Zea mays Endosperm Associate in Multisubunit Complexes. Plant Physiology 146, 1892-1908
[This paper was published back-to-back with that above and represents an extension of the work on wheat into maize, thus establishing that the novel regulatory mechanisms discovered are common with cereal endosperm. It also represents an important collaboration with colleagues at Iowa State University]. - C.G. Bowsher, E.F.A.L. Scrase-Field, S. Esposito, M.J. Emes and I.J. Tetlow (2007) Characterisation of ADP-glucose transport across the cereal endosperm amyloplast envelope. J. Exp. Bot 58, 1321-1332
[Unlike dicots and all other monocot tissues, in the endosperm of cereals the primary synthesis of ADPglucose – the soluble precursor of starch synthesis – occurs in the cytosol. This necessitates the transport of ADPglucose into the amyloplast and this paper provides a comprehensive kinetic characterisation of the transporter which is located in the amyloplast inner envelope]. - I.J. Tetlow, R. Wait, Z. Lu, R. Akkasaeng, C.G. Bowsher, S. Esposito, B. Kosar- Hashemi, M.K. Morell and M.J.Emes (2004) Protein Phosphorylation in Amyloplasts Regulates Starch Branching Enzyme Activity and Protein-Protein Interactions. The Plant Cell 16, 694-708
[This paper is the first to demonstrate that protein phosphorylation plays a key role in the regulation of starch biosynthesis and leads to changes in protein-protein interactions. We show that protein phosphorylation regulates the activities of Branching Enzymes IIa and IIb, but not BEI, and catalyses the reversible formation of a protein complex involving BEIIb, BEI and Starch Phosphorylase. This paper led to a huge surge of interest in this area and several groups across the world are now following this discovery and looking for other interactions. Our own group is now involved in three-way international collaboration involving the University of Guelph; CSIRO, Australia; and Iowa State University in this area.
Other refereed journal publications (2003-2009):
P. Tickle, M.M. Burrell, S. Coates, M.J. Emes, I.J. Tetlow and C.G. Bowsher (2009) Characterisation of plastidial starch phosphorylase in Triticum aestivum L. J. Plant Physiol 166, 1465-1478 (NSERC, BBSRC).
M.J. Emes(2009) Oxidation of methionine residues: the missing link between stress and signalling responses in plants. Biochem. J. 422, e1-e2.
Q. Liu, Z. Gu, E. Donner, I. Tetlow and M. Emes (2007) Investigation of digestibility in vitro and physiocochemical and properties of A- and B-type starch granules from soft and hard wheat flour. Cereal Chemistry 84, 15-21 [NSERC]
C.G. Bowsher, A.E. Lacey, G.T. Hanke, D.T. Clarkson, L.R. Saker, I. Stulen and M.J. Emes (2007) The effect of G1c6P uptake and its subsequent oxidation within pea root plastids on nitrite reduction and glutamate synthesis. J. Exp. Bot 58, 1109-1118 [BBSRC].
X. Yan, S. Khan, T. Hase, M.J. Emes and C.G. Bowsher (2006) Differential uptake of photosynthetic and non-photosynthetic proteins by pea root plastids. FEBS Letters 580, 6509-6512 [BBSRC].
D. Hutchings, S. Rawsthorne and M.J. Emes (2005) Fatty acid synthesis and the oxidative pentose phosphate pathway in developing embryos of oilseed rape (Brassica napus). J. Exp. Bot. (56, 577-585) [BBSRC]
Debnam, A.R. Fernie, A. Leisse, A. Golding, C.G. Bowsher, C. Grimshaw, J.S. Knight and M.J. Emes (2004) Altered activity of the P2 isoform of plastidic glucose 6-phosphate dehydrogenase in tobacco (Nicotiana tabaccum cv Samsun) causes changes in carbohydrate metabolism and response to oxidative stress in leaves. Plant Journal 38, 49-59
I.J. Tetlow, C.G. Bowsher and M.J Emes (2003) Biochemical properties and enzymic capacities of chromoplasts isolated from wild buttercup. Plant Science 165, 383-394 [BBSRC]
I.J. Tetlow, C.G. Bowsher, E. Scrase-Field, E. Davies and M.J. Emes (2003) The synthesis and transport of ADPglucose in cereal endosperms. J. App. Glycoscience 50, 231-236 [BBSRC]
E.J. Davies, I.J. Tetlow, C.G. Bowsher and M.J. Emes (2003) Molecular and biochemical characterisation of cytosolic phosphoglucomutase in wheat endosperm (Trticum aestivum L. cv. Axona). J. Exp. Bot. 54, 1351-1360 [BBSRC]
M.J. Emes, C.G.Bowsher, C. Hedley, M.M. Burrell, E.S.F. Scrase-Field and I.J. Tetlow (2003) Starch synthesis and carbon partitioning in developing endosperm. J. Exp. Bot. 54, 569-575 [BBSRC, Advanced Technologies, UK]
I.J. Tetlow, E.J. Davies, K.A. Vardy, C.G. Bowsher, M.M. Burrell and M.J. Emes (2003) Sub-cellular localisation of ADPglucose pyrophosphorylase in developing wheat endosperm and analysis of the properties of a plastidial isoform. J. Exp. Bot 54, 715-725
Teaching
My primary aim in teaching has always been to engage students in the process of discovery and not merely to be a conduit for information. Throughout my career I have taught at all levels across the undergraduate curriculum as well as having supervised over 20 graduate students. My approach is to encourage students to ask questions and form hypotheses, and not accept everything as 'given' - this, after all, is the basis of the scientific method. At present I teach a first year course on “Science, Society and the Media” which involves students from across the disciplines, examining methods of communication and the way that language, image and metaphor can be used to convey a set of ideas, as well as influence decision-making and public policy.
Laboratory Members
Burrell, Mark (PhD)
Liu, Fushan (PhD)
Ahmed, Zaheer (PhD)
Subasinghe, Renuka (PhD)
Rayirath, Usha (PhD)
Makhmoudova, Amina (technician)
Hollingshead, John (MSc)
Allan, Wendy (Postdoctoral Fellow)
Romanova, Nadya (Postdoctoral Fellow)