A Tale of Three Cell Types: Alkaloid Biosynthesis Is Localized to Sieve Elements in Opium Poppy
AUTOR(ES)
Bird, David A.
FONTE
American Society of Plant Biologists
RESUMO
Opium poppy produces a diverse array of pharmaceutical alkaloids, including the narcotic analgesics morphine and codeine. The benzylisoquinoline alkaloids of opium poppy accumulate in the cytoplasm, or latex, of specialized laticifers that accompany vascular tissues throughout the plant. However, immunofluorescence labeling using affinity-purified antibodies showed that three key enzymes, (S)-N-methylcoclaurine 3′-hydroxylase (CYP80B1), berberine bridge enzyme (BBE), and codeinone reductase (COR), involved in the biosynthesis of morphine and the related antimicrobial alkaloid sanguinarine, are restricted to the parietal region of sieve elements adjacent or proximal to laticifers. The localization of laticifers was demonstrated using antibodies specific to the major latex protein (MLP), which is characteristic of the cell type. In situ hybridization showed that CYP80B1, BBE, and COR gene transcripts were found in the companion cell paired with each sieve element, whereas MLP transcripts were restricted to laticifers. The biosynthesis and accumulation of alkaloids in opium poppy involves cell types not implicated previously in plant secondary metabolism and dramatically extends the function of sieve elements beyond the transport of solutes and information macromolecules in plants.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=280566Documentos Relacionados
- Uncoupled defense gene expression and antimicrobial alkaloid accumulation in elicited opium poppy cell cultures.
- Antisense RNA-Mediated Suppression of Benzophenanthridine Alkaloid Biosynthesis in Transgenic Cell Cultures of California Poppy1
- Sanguinarine Biosynthesis Is Associated with the Endoplasmic Reticulum in Cultured Opium Poppy Cells after Elicitor Treatment1
- CYP719B1 Is Salutaridine Synthase, the C-C Phenol-coupling Enzyme of Morphine Biosynthesis in Opium Poppy*
- Papaver somniferum (opium poppy).