Abstract
Addition of micromolar concentrations of quercetin or rutin to suspension cell cultures
of Sanguinaria canadensis L. (bloodroot) induced the biosynthesis of sanguinarine and chelerythrine in a dose-dependent
manner. In contrast, related compounds: baicalein, naringin, naringenin, catechin,
caffeic acid and benzoic acid displayed very weak inductive activity. Of the two active
flavonoids, quercetin was the most effective for inducing benzophenanthridine alkaloid
biosynthesis, with doses of 100 µM increasing alkaloid production over 375% as compared
to negative controls. Quercetin's inductive effects were similar to that of an elicitor
derived from fungus Penicillium expansum (PE-elicitor). Suppression of quercetin and PE-induced alkaloid biosynthesis by low
doses of actinomycin D (5 µg/ml), α-amanitin (20 µg/ml), or cycloheximide (1 µg/ml)
demonstrate a requirement for both RNA and de novo cytoplasmic protein synthesis and suggest that alterations in gene expression are
involved in the inductive mechanism. Furthermore, quercetin-induced alkaloid biosynthesis
was significantly reduced by pretreatment of the cells with the calcium chelator,
EGTA (3 mM), or the calcium channel inhibitor, verapamil (100 µM), suggesting that
this process was calcium dependent.
Key words
Sanguinaria canadensis
- Papaveraceae - sanguinarine - chelerythrine - quercetin - elicitor - calcium
