Biotechnological Interventions of Hairy Roots of Tropane Alkaloid-Bearing Plants

Abstract

As one large group of plant secondary metabolites, tropane alkaloids (TAs) can be produced by a few genera of the family Solanaceae including Anisodus, Atropa, Datura, Hyoscyamus, and Scopolia. Due to their anti-cholinergic activity, tropane alkaloids including hyoscyamine and scopolamine are widely used as antispasmodics and mydriatics. Because of low contents in tropane alkaloid-bearing plants, it is urgent to elevate the production of tropane alkaloids by means of biotechnology approaches to meet the increasing clinical demand. Hairy roots, with the characters of fast-growing, auxin-independent, and genetically stable, were considered as a promising system to produce active plant-origin compounds including tropane alkaloids. Recently, hairy root systems of some tropane alkaloid-producing plants such as Anisodus acutangulus have been successfully established. Meanwhile, several key enzymes involved in the TAs biosynthetic pathway have been cloned and introduced into related genetic engineered hairy root systems, which lay the foundation for production of tropane alkaloids in hairy roots by large-scale bioreactors in the future. Here, the recent advances of pharmacological activity, hairy root, biosynthesis pathway, and genetic engineering were summarized, and problems along with prospects were also discussed.