Cell biology of plant natural products

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A gas chromatograph (GC) will be used to analyze the chemical composition of complex mixtures of plant natural products. This instrument offers superior resolution and greater sensitivity and precision than most other chemical separation methods.  A complex mixture of chemicals in solution is heated to sufficiently high temperature to vaporize the entire solution.  This vapour is then forced through a porous matrix at high pressure.  The different chemical components will pass through the matrix at different rates, depending on their physical size and properties, allowing for precise separation of literally hundreds of different chemicals, sometimes differing only by a single atom.  This GC will be used for studying natural products in two systems:  plant cuticle secretion and artemisinin biosynthesis and transport.   The plant cuticle consists of secreted lipids, which protect the plant from insects, uv light, and non-stomatal water loss.  Understanding of how plant epidermal cells synthesize and secrete this protective layer is rudimentary, despite the importance of the cuticle in agriculture and plant ecology.  We are studying how these lipids exported from the epidermal cells to the surface,   the mechanism of which is completely unknown. Artemisinin is used as part of an effective anti-malarial treatment known as artemisinin-based combination therapy (ACT).  Artemisinin been shown to be very effective, but the rising cost of production is making this drug difficult to obtain for many in the developing world, where it is needed the most.  Currently, the only economical source of this drug is from the secretory glands of the plant, Artemisia annua.  Only a fraction of the essential oils in the glands of Artemisia contains artemisinin.  Understanding how these compounds are synthesized and secreted into the glands will be essential to improving artemisinin production for medical use.