Variation in tropane alkaloid accumulation within the solanaceae and strategies for its exploitation

Abstract

Petioles from over 1000 individual plants of the genera Datura, Scopolia and Hyoscyamus were analysed to establish the variation in the levels and patterns of tropane alkaloids which occur between plants. Transformed root cultures were initiated from plants of which analyses suggested extremely high or low alkaloid biosynthetic capacities, or favourable alkaloid patterns. These root cultures were then studied in detail by HPLC, GC and GC-MS. Root cultures showed substantial differences in alkaloid patterns between different species, but the quantitative differences in tropoyl esters of α-tropine (hyoscyamine plus scopolamine) observed between different lines were less than those seen between plants. This difference is interpreted as to some extent reflecting the influence of transport and storage effects, as well as biosynthetic capacity, in determining alkaloid levels in plant petioles. In addition, there is some indication that the full biosynthetic capacity may not always be expressed in culture. Despite these limitations, the identification of plants showing favourable characteristics still, however, proved a useful first step in the development of scientifically and potentially biotechnologically interesting root cultures.