earticle

영어

Papaver somniferum produces a variety of benzylisoquinoline alkaloids (BIAs) and has been known as the major plant source producing morphinan alkaloids including thebaine, codeine and morphine. Since the earliest stage of in vitro cultures of P. somniferum, the production of morphinan alkaloids in tissue culture has been attempted. Undifferentiated callus cultures of P. somniferum have been reported to lose their ability to synthesize morphine, but the reasons has not been clearly understood. Somatic embryogenesis from undifferentiated callus of Papaver somniferum contributed to differential expression of gene transcripts and proteins involved in the benzylisoquinoline biosynthesis accompanying in vitro morphine production. After initiation of differentiation of callus, overall gene transcripts on the BIA biosynthetic pathway of .somniferumaccumulateinsomaticembryos; and 37.5 μg of morphine from 1 gram of dried somatic embryos was measured using LC tandem mass spectrometer. Among genes on the morphinan alkaloids biosynthetic pathway, salutaridine reductase (SR) which is stereo-specific cytosolic enzyme reducing salutaridine into salutaridinol before thebaine, doesn’t accumulate in undifferentiated callus at all; whereas both SR gene transcript and protein are detected in somatic embryos. Major latex protein, the most abundant protein in plants’ laticifer where morphinan alkaloids accumulate, was expressed during somatic embryogenesis and could be adopted as an index of differentiation of callus according to somatic embryogenesis. This study represents that differentiation during indirect somatic embryogenesis of P.somniferum activates morphinan alkaloids biosynthesis, which is confirmed by comparative profiling of metabolites, gene transcripts and proteins involved in BIA biosynthesis.