Influence of sugars on the reddening of triturated florets of dyer's saffron flowers

Pentoses, hexoses and disaccharides were administered to the triturated florets of dyer's saffon (Carthamus tinctorius) and their effects on enzyme-catalyzed floret reddening examined spectrophotometically. Among the sugars tested, hexoses promoted reddening most prominently. On average, a 4.2-fold increase in the certhamin content was observed when hexoses were added to the crushed materials. Disaccharides followed these. Upon incubation of the triturated tissues with 10 mM sugars, the pigment producing activity was raised to 3.4-fold or more. Pentoses were also potent stimulators, although their efficiencies were somewhat lower (3.2-fold). On the whole, D-forms were more stimulative than L-forms (D-forms - 3.6-fold, L-form -2.8-fold). Based on these comparisons, we concluded that sugars play a role in floret reddening through interaction with endogenous precarthamin-oxidizing enzyme(s) in the floral tissues of the garden plant.