Title: ENVIRONMENTAL IMPACTS ON SECONDARY METABOLITES IN MEDICINAL PLANTS
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: December 29, 2004
Publication Date: July 3, 2005
Citation: Foster, J.G. 2005. Environmental impacts on secondary metabolites in medicinal plants. In: Morales, M., Foster, J.G., editors. Proceedings of the Third Appalachian Symposium on Medicinal and Aromatic Plants. Technology Transfer for Growers, Healthcare Providers, and Entrepreneurs, September 22-25, 2004, Beckley, WV. p. 36-41.
Once considered waste products of plant metabolism, secondary metabolites are natural products that are now known to facilitate plant survival. These compounds, numbering in excess of 45,000 and exhibiting diverse chemical structures, do not participate directly in plant growth and development, but influence ecological interactions between plants and their environment. They promote the persistence of a plant by attracting supportive organisms, protecting sensitive cellular components during times of stress, and deterring competitors and predators. The types and concentrations of secondary metabolites vary with plant species, tissue type, physiological development, and conditions to which the plant is exposed. In general, stressed plants produce more secondary metabolites than non-stressed plants, but the protection that is achieved occurs at the expense of plant growth. Manipulating plants to optimize secondary metabolite concentration and dry matter production is important to the economics of medicinal plant cultivation. Forage chicory (Cichorium intybus L.) is a plant that has potential as a medicinal plant for livestock. Research with this plant provides excellent examples of environmental impacts on secondary metabolite composition. Application of management practices that promote low or high concentrations of specific secondary metabolites in chicory herbage could result in palatable forage or an herbal supplement for controlling gastrointestinal parasites in small ruminants, respectively.