Calystegines in root cultures of Atropa belladonna respond to sucrose, notto elicitation

Calystegines are norpseudotropine alkaloids accumulating in root cultures o f Atropa belladonna, together with tropine derivatives, e.g. hyoscyamine. B oth alkaloid groups are derived from the tropane alkaloid pathway. For the investigation of the regulation and individual steps of tropane biosynthesi s, methods for the induction of the pathway were tested. Elicitation by chi tosan, or defence responses to ABA and methyl jasmonate did not enhance cal ystegine accumulation, but led to a more or less pronounced decrease. By bl ocking one aim of the diverged tropane pathway, calystegine accumulation ca n be increased, but total tropane alkaloid formation does not increase cons iderably. By elevation of sucrose supply, both, total alkaloids and calyste gines in particular were increased approximately threefold. The mechanism o f the induction of the biosynthesis by sucrose is not known and needs furth er experiments. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.