Synthesis of Atropine by Isolated Roots and Root-Callus Cultures of Belladonna

Abstract

1. Isolated roots, root callus, and stem and leaf callus of Atropa belladonna L. were grown in vitro to determine the site of synthesis of atropine. Gautheret's medium plus various supplements were used. 2. The root callus possessed the capacity for unlimited growth in vitro and for development of an entire plant in that roots, stems, and leaves were formed. 3. Atropine in measurable amounts was obtained from the isolated roots and root callus grown in darkness, in absence of stems and leaves. The nutrient material in the medium apparently contained the necessary precursors of atropine. 4. Atropine was not detected in excised stem-and-leaf-callus tissues which had been grown in vitro for at least 4 months and which had not produced macroscopic adventitious roots. 5. The medium in which the isolated roots were grown contained 25-50 mg. of atropine which was detected chromatographically. 6. It appears that the root is the primary if not the sole site of atropine synthesis, when synthesis of atropine is considered on an organismal level, and that at least the final and most important rate-limiting steps of atropine synthesis occur in the root.