Alkaloid biosynthesis, regulation developmental

DE LUCA, V., FERNANDEZ, J.A., CAMPBELL, D., KURZ, W.G.W., Developmental regulation of enzymes of indole alkaloid biosynthesis in Catharanthus roseus. Plant Physiol, 1988, 86,447-450. 

FACCHINI, P.J., BIRD, D.A., Developmental regulation of benzylisoquinoline alkaloid biosynthesis in opium poppy plants and tissue cultures. In Vitro Cell. Dev. Biol.- Plant, 1998,34, 69-79. 

In some cases, however, the regulation of the in vivo activity of secondary metabolic enzymes is more complicated. In the hyphae of Penicillium cyclopium the activities of the enzymes of benzodiazepine alkaloid biosynthesis (D 8.4.2) are measurable at a relatively early stage of the mold s development, whereas alkaloid formation is expressed later (Fig. 8). The increase of the rate of biosynthesis is immediately stopped by inhibitors of gene expression, e.g., 5-fluorouracil or cycloheximide (D 3.3.7), even at developmental stages at which the in vitro measurable enzyme activities have already their maximum levels. This indicates the existence of a protein limiting the rate of alkaloid formation, which is synthesized much later than the investigated enzymes. 

DeLuca, V., J. Balsevich, R. T. Tyler, U. Eblert, B. D. Panchuk, and W. G. W. Kurz, Biosynthesis of indole alkaloids Developmental regulation of the biosynthetic pathway from tabersonine to vindoline in Catharanthus roseus, J. Plant Physiol., 12S, 147-156 (1986). 

Information on cellular metabolic organization of caffeine biosynthesis and catabolism links to purine nucleotide metabolism, intercellular translocation, and accumulation mechanisms at specific cellular sites, such as chloroplasts and vacuoles, have yet to be fully revealed. Cell-, tissue-, and organ-specific synthesis and possibly catabolism of purine alkaloids may be regulated by unique and unknown developmental- and environmental-specific control mechanisms. A great deal of fascinating purine alkaloid biology in plants still remained to be discovered. 

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