Improved accumulation of ajmalicine and tetrahydroalstonine in Catharanthus cells expressing an ABC transporter
ABSTRACT The biosynthetic pathway of monoterpenoid indole alkaloids in Catharanthus roseus is located throughout various membranes at both the cellular and intercellular levels. ATP-binding cassette (ABC) transporters are known to export vincristine and vinblastine from human cancer cells. It has recently been shown that ABC transporters are also involved in the transport of various monoterpenoid alkaloids in Catharanthus roseus cells. Over-expression of an ABC transporter in this plant might therefore affect the regulation of the alkaloid biosynthetic pathway. CjMDR1, an ABC transporter gene originally isolated from Coptis japonica, was expressed in Catharanthus roseus cell cultures. Cells showing a positive PCR signal of the transgene in both cDNA and genomic DNA samples were subject to transport studies using selected substrates. Unexpectedly, transport of the isoquinoline alkaloid berberine, the main substrate of CjMDR1 transporter in Coptis japonica, was not affected as compared with control and wild-type Catharanthus cells. On the other hand, the endogenous alkaloids ajmalicine and tetrahydroalstonine were accumulated significantly more in Catharanthus roseus cells expressing CjMDR1 in comparison with control lines after feeding these alkaloids.
SourceAvailable from: Tsubasa Shoji
Article: Alkaloid transporters in plants[Show abstract] [Hide abstract]
ABSTRACT: Plants produce a multitude of secondary metabolites, including alkaloids with biological activities, and many alkaloids have been used for medicinal purposes. The biosynthetic enzymes and genes involved in alkaloid metabolic pathways exhibit divergent localizations, implying that alkaloid metabolites, including pathway products and intermediates, travel from organelle to organelle, cell to cell, and organ to organ. Biochemical studies have indicated that specific transporters move these metabolites. Indeed, molecular and cellular approaches have identified alkaloid transporters of the ATP-binding cassette (ABC) protein, multidrug and toxic compound extrusion (MATE), and purine permease (PUP) families. Interestingly, some of these transporters were found to be required for the efficient biosynthesis of alkaloids in plants. Here, we provide an updated inventory of alkaloid transporters and discuss the possibility of genetically manipulating the expression of these transporters to increase the accumulation of valuable alkaloid compounds.Plant Biotechnology 01/2014; 31(5):453-463. DOI:10.5511/plantbiotechnology.14.1002a · 1.06 Impact Factor
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ABSTRACT: Catharanthus roseus (L.) G. Don. is a well known medicinal plant. It produces several phyto-compounds many of which show anticancerous properties. The yields of these compounds are however, very low. In this present article, the current development of secondary metabolite synthesis in C. roseus involving biotechnology has been reviewed keeping in mind the various basic fac-tors that influence yield. The importance of cell culture, the role of culturing conditions and other approaches aiming at higher production of alkaloids have been discussed. The genes encoding important enzymes, proteomics, expressed sequence tag and transcription factors in relation to alka-loid yield have also been summarized in order to under-stand the regulatory mechanisms of C. roseus.
OMICS Applications in Crop Science, Edited by Debmalya Barh, 12/2013: chapter 10: pages 325–384; CRC Press (Taylor & Francis Group), Boca Raton., ISBN: Print ISBN: 978-1-4665-8525-6; eBook ISBN: 978-1-4665-8531-7