The major themes of our lab are plant metabolism, plant-environment interactions, and metabolic engineering of plants and microbes. Our research group is currently focused on understanding the biosynthesis and functions of plant surface barriers that are composed mostly of polymerized lipids and associated waxes. These barriers protect plants against various environmental stresses, such as drought and pathogen attack. Our ultimate aim is to provide information and tools for the development of stress-tolerant crop plants. We are also part of an international consortium of researchers working on a project titled ‘Industrial Crops Producing Added Value Oils for Novel Chemicals’ (ICON). Our aim is to develop high value plant oils to replace some of the fossil oils currently used in the global chemicals industry.
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Plants have three major extracellular lipid-and phenolic-based biopolymers that protect them from uncontrolled water loss and pathogens: cuticle, suberin, and sporopollenin. Cuticle coats the aerial surfaces of land plants. It consists of waxes embedded within and overlaying an esterified polymer of C16 and C18 chain-length fatty acids (cutin). Suberin is a polymer similar to cutin that is present in the cell walls of various external and internal tissue layers, including root endodermis and peridermis. Sporopollenin is a lipid- and phenolic-based polymer present in the outer layer of pollen walls (exine). These three chemically-related barriers form key protective interfaces between the plant and its environment. Major goals of our research program are to understand the enzymatic synthesis, physiological functions, and regulated deposition of these plant extracellular barriers.
Figure 1. Three types of extracellular biopolymers in plants.
We are using a combination of molecular genetics, biochemical, cell biology, and genomic approaches to carry out our research objectives. Most of our studies use Arabidopsis thaliana, as mutants affecting the production of these barriers are relatively easy to obtain with this model plant. We are translating the fundamental knowledge gained from our Arabidopsis research to crop plants, such as the emerging oilseed crop Camelina sativa that is being developed as a source of biofuels and high-value bioproducts. We are also taking advantage of microbes heterologously expressing plant enzymes for biochemical and engineering studies.
A detailed understanding of protective plant surface lipid barriers will assist plant breeders and biotechnologists in generating crops that are more stress resistant. The improvement of crop tolerance to drought is particularly attractive considering changing climate conditions are currently limiting crop production in large areas of the world, including Canada, and will likely get worse over the next few decades. In addition, plant surface lipids are composed of renewable hydrocarbons that are chemically suitable for replacement of petroleum products as sources of energy and chemical feedstocks. Fundamental knowledge of plant surface lipid biosynthesis at the molecular level is critical for harnessing this renewable chemical resource to its full potential.
Funding
Our lab is currently funded by grants from the Natural Sciences and Engineering Research Council of Canada (NSERC Discovery and Accelerator Grants), the Canadian Foundation for Innovation, the Ontario Research Fund, and The Embassy of France in Canada (France-Canada Research Fund).
