Biosynthetic and metabolic activities of some organelles in Papaver somniferum latex

Abstract

The biosynthesis of the five major alkaloids of the opium poppy (Papaver somniferum L. from radioactive dihydroxyphenylalanine has been studied in the 1000 g, 10 000 g, 100 000 g pellets and the 100 000 g supernatant fractions of the capsule latex. A normal poppy variety as well as one which produces only traces of alkaloids were used. Definite evidence of biosynthesis was obtained for both varieties but only in the 1 000 g pellet (as previously reported . None was found in the other fractions although electron microscopy showed that organelles, including vesicles, were present. The amounts of alkaloid biosynthesized however were very small relative to the amounts involved in the rapid changes already reported for the developing capsules. In contrast, all fractions of the latex were able to metabolize T-morphine in vitro, with the 100 000 g supernatant showing the highest activity and the amounts involved were also consistent with the changes found in the living plant.