Grant: Discovery Grants Program - Individual

The evolution of the land plant habit has culminated in the vast array of vascular plant species that now dominate terrestrial ecosystems and are essential in providing food, fibre, and energy for human activities. Key evolutionary innovations were likely required for the adaptation of land plants to the terrestrial environment, including evolution of metabolic pathways for defense, communication, and structural purposes. Furthermore, development of cellulose and lignin-rich secondary cell walls in xylem and secondary xylem (wood) was required in vascular land plants for structural support and nutrient/water transport. The focus of this proposal is on the nature and regulation of key processes such as natural product biosynthesis and fibre/secondary cell wall/wood differentiation and formation in model plants (Arabidopsis, moss, poplar) and commercially valuable (poplar, spruce) trees. Specifically, our experiments will investigate newly discovered genes encoding enzymes for a potentially novel class of natural products required for pollen viability and genes encoding enzymes for the biosynthesis of the signaling compound jasmonic acid, required for response to environmental stresses such as insect attack. We will also study regulatory genes such as transcription factors and receptor kinases involved in programming cells to differentiate into xylem and fibre cells rich in cellulose and lignin, and study a class of cell wall localized chitinase-like proteins that appear to facilitate cellulose deposition into cell walls. This research will provide basic information about these unique aspects of plant function and suggest how these processes might be modified, with potential practical spin-offs in plant fertility control and resistance to insect pests. The work on regulation of secondary cell wall formation and fibre/xylem differentiation has important implications for understanding the formation of biomaterials (fibre and wood) that will be increasingly important as energy and carbon sources in the coming decades and may suggest new ways to manipulate and/or select for plant and tree genetic variants that will be more amenable for biomass and/or biofuels applications.