Factors Influencing Secondary Metabolite Synthesis in Medicinal and Aromatic Plants

摘要

Secondary metabolites are organic compounds produced by plants in smaller amounts which are not concerned with the growth, photosynthesis, reproduction or any other primary functions. These molecules are known to play a vital role in the adaptation ofplants to their environment, serve as defense and signal compounds and indirectly help in pollination. Secondary metabolites include alkaloids, terpenes, phenols, glycosides, saponins, gums, oleoresins, etc. which are potential sources of pharmaceuticals, agrochemicals, flavours, fragrances, colours, botanicals, food additives etc. They are considered as active principles of medicinal and aromatic plants.The global market for traditional medicines was estimated at US$ S3 billion annually in 2008 and increasing at the rate of5-15 per cent annually. This is an indication of possible growing demand for herbal drugs in coming years. Several factors like stress factors, geneticfactors, developmental stages of plant, dates of sowing, nutrient levels, growthregulators, mutagens etc. influence on the secondary metabolites in plants.Stress conditions resulted in the higher secondary metabolite accumulation which play a major role as defense mechanism in plants. Seasonal variations alter the secondary metabolite content in plants. Planting at the right time with optimum fertilizer dose resulted in highest yield of these compounds. Hence, to meet the increasing demand, all the factors have to be considered to enhance the production of the secondary metabolites prior to commercial cultivation of these crops.