Distribution of morphinan and benzo[c]phenanthridine alkaloid gene transcript accumulation in Papaver somniferum

The opium poppy Papaver somniferum L. produces the antimicrobial benzo[c]ph enanthridine alkaloid sanguinarine and the narcotic analgesic morphinan alk aloid morphine. Transcripts of three genes of alkaloid biosynthesis in P. s omniferum in developing seedlings, mature plants and plant cell suspension culture were monitored for temporal/spatial or for methyl jasmonate-induced accumulation by RNA gel blot analysis. These gents encoded (S)-N-methylcoc laurine 3'-hydroxylase (CYP80B1) that is common to morphine and sanguinarin e biosynthesis, the berberine bridge enzyme (BBE) that lies on the pathway to sanguinarine, and codeinone reductase (COR) the penultimate enzyme of mo rphine biosynthesis. In developing P. somniferum seedlings, the morphine pr ecursor thebaine was present throughout the first twenty days of germinatio n. In contrast, sanguinarine was present in detectable quantities only afte r day five after germination and continued to increase at least until day t wenty. Accumulation of cyp80b1 bbe1 and cor1 gene transcripts paralleled th ese differences. In the mature poppy plant, cyp80b1, bbe1 and cor1 gene tra nscripts were detected in the root, the stem, the leaf lamina and the leaf mid rib. Only cup80b1 and cor1, however, were found in the flower bud and t he capsule. Consistent with the fact that sanguinarine accumulation, but no t that of morphine, can be induced in opium poppy cell suspension culture b y addition of methyl jasmonate to the culture medium, cyp80b1 and bbe1, but not cor1 transcript accumulated in response to elicitor treatment. (C) 200 0 Elsevier Science Ltd. All rights reserved.