Synthesis of Benzylisoquinoline Alkaloids and Other Tyrosine-Derived Metabolites in Hairy Root Cultures

Abstract

Tyrosine is the starting unit of a wide range of specialized metabolites in plants, including the pharmaceutically important benzylisoquinoline alkaloids (BIAs). Although in vitro cell suspension cultures from some BIA-producing species have been obtained, there are only a few documented cases for the establishment of hairy root cultures, even though this system has been intensively used in other alkaloid-producing plants. Hairy root cultures have been generated from three members of Papaver genus, including P. somniferum, P. orientale, and P. bracteatum. Morphine- and morphinan-type alkaloids have been identified in all of them, suggesting that the biosynthetic capacity is maintained in all cases. Sanguinarine and other benzophenanthridine-type alkaloids were also identified in these cultures, as well as in hairy roots from Eschscholzia californica (Papaveraceae). Only one report of berberine-producing hairy root was found in an extensive literature search, although attempts on probable transformation of recalcitrant species were detected. The use of Beta vulgaris hairy root cultures for the synthesis of betalains, pigments derived from tyrosine, was also included.