The Characteristics of Atropine Transport in Seedlings and Regenerated Plantlets of Duboisia myoporoides

Summary [Carbonyl- 14 C]atropine sulfate solution was fed to regenerated plantlets or seedlings of Duboisia myoporoides at various stages of development via either the root or the leaves and the subsequent distribution of radioactivity in various organs compared. Four-week-old regenerated plantlets did not transport atropine from the roots to the leaves but did from the leaves to the roots, whereas the seedlings were able to transport in both directions at all ages examined. The regenerated plantlets gradually acquired an ability to transport atropine from the roots to the leaves during development and eventually, when they were 12 weeks old, they had a transport capacity comparable with that of the seedlings. Furthermore, it was found that regenerated shoots transported labelled atropine from the stem to the leaves at any stage of growth, and that 4-week-old regenerated plantlets transported radioactive NaH 2 12 PO 4 and Na 2 35 SO 4 from the root to the leaf, in contrast to their inability to transport atropine. These results indicate that the development of the root of regenerated plantlets of D. myoporoides was incomplete in relation to the transport mechanism specific to the alkaloid, atropine, and that there must be different mechanisms operating with respect to atropine transport from root to leaf or from leaf to root.