On the Biosynthesis of Carotenoids.

Abstract

The petals of two variants of Viola tricolor[long dash]the common yellow and an "apricot"-colored variety[long dash]have been examined for carotenoid pigments. The former has almost exclusively xanthophyll components, the latter has predominantly lycopene. The ionone-effect on Phycomyces surpasses the effect of light, though the two are complementary. With radioactive fructose in the medium, it is shown that Phycomyces draws selectively on the non-sugar carbon. More than 60 percent of the carotene carbon is drawn from the non-sugar fraction which comprises only 9 percent of the carbon in the medium.