Enhanced codeine and morphine production in suspended Papaver somniferum cultures after removal of exogenous hormones

Summary Morphine and codeine accumulation in Papaver somniferum suspension cultures increased markedly after removal of hormones from the medium. Cultures developed hormone self-sufficiency without organogenesis or development of meristemoids; enhanced synthesis of morphinan alkaloids was not dependent on formation of shoots, roots or embryos. Without exogenous hormones, maximum codeine and morphine concentrations were 3.0 mg g^–1 dry weight and 2.5 mg g^–1 dry weight respectively, up to three times higher than in cultures supplied with hormones. Hormone-deprived cells produced a higher ratio of codeine:morphine than cultures supplied with auxin and cytokinin. Improved alkaloid production was correlated with slower overall growth rate.