Factors affecting morphogenesis and secondary metabolite production in Echinacea purpurea L

Investigations were conducted to develop a better understanding of factors that affect morphogenesis and secondary metabolite production in Echinacea purpurea L. Thidiazuron effectively induced morphogenesis in explants cultured in solid and liquid media. The observed morphogenic responses required balanced levels of endogenous cytokinin, auxin, melatonin, calcium and sodium. Regenerated plants grown in a temporary immersion bioreactor system contained concentrations of caffeic acid derivatives similar to those found in field grown plants. The endogenous level of these compounds was affected by the exogenous application of various plant growth regulators. Taken together, these investigations provide new insight into the mode of action of thidiazuron and provide a framework for efficient in vitro micropropagation and growth systems for the production of high quality herbal medicine.