Dr Tom Roberts

Summary

I have a passion for understanding the properties and functions of plant proteins. While the genomes of an ever increasing number of plant species have been fully sequenced, the functions of most of the proteins encoded by these genes have not be determined experimentally and many are completely unknown. The more we understand about the properties and functions of plant proteins, the easier it will be to breed crops that yield high-quality products under a range of biotic and abiotic stresses and to understand how plant proteins affect the properties of foods and other plant products.

Research interests

I am interested in a variety of plant proteins, their properties and their functions. My major interest for many years has been the structure, properties and functions of a family of proteins called serpins in plants and green algae. Most serpins are potent, irreversible inhibitors of specific serine or cysteine proteases. Serpins are fascinating proteins from many perspectives and have a remarkable variety of functions in animals. The structures and functions of plant and algal serpins are largely unknown but some breakthroughs have been made in recent years - see Ahn et al. (2009) and Lampl et al. (2010) listed below. Collaborators in my serpins research iinclude Jørn Hejgaard (Denmark), Robert Fluhr (Israel), Joon-Woo Ahn (Korea), Paul Curmi (University of New South Wales), Brian Atwell (Macquarie University) and Peter Sharp (University of Sydney).

One of my more recent research interests is in the allergenicity of peanuts. Peanut allergy is a major problem in Australia and many other countries; indeed some people (including children) can suffer life-threatening anaphylactic shock upon ingestion of peanuts, even extremely small amounts. The allergens in peanut kernels are seed storage proteins but what determines their absolute and relative abundance in the mature peanut? Collaborators are Nicole Walczyk (Macquarie University), Penny Smith (University of Sydney) and Euan Tovey (University of Sydney).

Another of my recent interests is the response of plants to an energy crisis. The model system for this work is the rice coleoptile, the sheath that protects the growing shoot from a germinated rice grain. The energy crisis we induce is through oxygen deprivation, either hypoxia (low oxygen) or anoxia (no oxygen). Responses studied include growth, energy allocation, transcription (microarrays) and translation (proteomics). Collaborators are PhD student Joshua Edwards (Macquarie University), Brian Atwell (project leader, Macquarie University) and Jim Whelan (University of Western Australia).

To pursue these interests my research involves a broad range of techniques in plant physiology, cell biology, molecular biology and biochemistry. Techniques employed recently include radiolabelling, confocal microscopy, microarray analysis, RT-PCR and 2D-DIGE. Bioinformatics analysis underpins many aspects of my projects.

Please contact me if you are interested in pursuing a PhD in one of the above topics.

Background

After studying at James Ruse Agricultural High School in Sydney, I completed a BScAgr Honours degree at the University of Sydney in 1988, in which I majored in agricultural chemistry. I then received an Alexander Hugh Thurburn PhD scholarship and completed a PhD in plant biochemistry (ureide catabolism and glyoxylate aminotransferases) in 1994.

After my PhD research I worked as a Postdoc at Lund University, Sweden (1994-5) on the properties and functions of the multiple NAD(P)H dehydrogenases in plant mitochondria. Back in Sydney I then worked in food chemistry, developing novel methods for the purification of pharmaceutical-grade lactose from cheese whey at the University of Western Sydney/CSIRO North Ryde (1995-6). I returned to Scandinavia and worked as a technical editor at Lund University and at the Royal Agricultural and Veterinary University in Denmark, as well as a Research Scientist at Novartis Seeds in Sweden. I then secured a 3-year Research Fellowship (1997-2000) at the Risø National Laboratory and the Technical University of Denmark on the properties and functions of serpins in barley and wheat.

Returning to Sydney in late 2000, I worked as a Research Fellow in the Macquarie University Centre for Analytical Biotechnology and conducted research on the mechanism, structure and regulation of magnesium chelatase, a key enzyme in (bacterio)chlorophyll biosynthesis. I also gained experience in university teaching at Macquarie University and at the University of Sydney. In 2004 I secured an ongoing lectureship in the Department of Biological Sciences and then in the Department of Chemistry and Biomolecular Sciences at Macquarie University. I was a Key Researcher in the Grain Foods CRC, which ended in 2009. I became Senior Lecturer at Macquarie University in 2009. I have taught a range of units there including 200-level plant structure and function, 300-level cell and developmental biology and 300-level molecular plant biology.

I moved to the University of Sydney in January 2012. I continue to supervise a Macquarie University PhD student (Nicole Walczyk) working on peanut allergens and an Honours student (Julian May) working on the serpins in rice coleoptile senesence. I am Associate Supervisor for a PhD student (Joshua Edwards) working on energy metabolism in rice coleoptiles.

Recent publications

• Vella NG, Joss TV and Roberts TH (in press). Chilling-induced ultrastructural changes to mesophyll cells of Arabidopsis grown under short days are almost completely reversible by plant re-warming. Protoplasma
• Fluhr R, Lampl N and Roberts TH (in press). Serpin protease inhibitors in plant biology. Physiologia Plantarum
• Roberts TH, Lampl N and Fluhr R (2011). Plants and the Study of Serpin Biology. Chapter 17 in Whisstock JC and Bird PI: Methods in Enzymology 499, 347–366
• Lampl N, Budai-Hadrian O, Davydov O, Joss TV, Harrop SJ, Curmi PMG, Roberts TH and Fluhr R (2010). Arabidopsis AtSerpin1: crystal structure and in vivo interaction with its target protease RESPONSIVE TO DESICCATION-21 (RD21). Journal of Biological Chemistry 285, 13550–13560
• Jerkovic A, Kriegel AM, Bradner JR, Atwell BJ, Roberts TH and Willows RD (2010). Strategic distribution of protective proteins within bran layers of wheat (Triticum aestivum L.) protects the nutrient-rich endosperm. Plant Physiology 152, 1459-1470
• Ahn J-W, Atwell BJ and Roberts TH (2009). Serpin genes AtSRP2 and AtSRP3 are required for normal growth sensitivity to a DNA alkylating agent in Arabidopsis. BMC Plant Biology 9, Article 52 (11 pp)
• Mak Y, Willows RD, Roberts TH, Wrigley CW, Sharp PJ and Copeland L (2009). Germination of wheat: a functional proteomics analysis of the embryo. Cereal Chemistry 86, 281–289
• Peterson RA, Bradner JR, Roberts TH and Nevalainen KMH (2009). Fungi from koala (Phascolartos cinerus) faeces produce enzymes with activities against a range of recalcitrant substrates. Letters in Applied Microbiology 48, 218–225
• Roberts TH and Hejgaard J (2008). Serpins in plants and green algae. Functional and Integrative Genomics 8, 1–27
• Haynes PA and Roberts TH (2007). Subcellular shotgun proteomics in plants: looking beyond the usual suspects. Proteomics 7, 2963–2975

Contact

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