The oxidative deamination of N-methylputrescine is an essential step in both pyridine and tropane alkaloid biosynthesis. Reverse genetic approaches have not resulted in the cloning of a methylputrescine oxidase gene (MPO). However, we have used a homology-based approach to clone a full-length tobacco MPO1 cDNA. The MPO1 gene is part of a small multigene family comprised of approximately six members. MPO1-like transcript levels increased in roots that were either deprived of auxin or treated with methyl jasmonic acid. Similar to other known nicotine biosynthetic genes in domesticated tobacco, MPO1-like mRNA levels were lower in roots with the mutant a and b alleles. The MPO1 protein was expressed in bacteria as a recombinant Thioredoxin-His(6)-MPO1 fusion protein. The recombinant MPO1 protein utilized N-methylputrescine more efficiently than other diamines. Therefore, the kinetic properties of the MPO1 enzyme may play an important role in determining the pyridine alkaloid profiles observed in tobacco roots.
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http://dx.doi.org/10.1016/j.phytochem.2006.11.003 | DOI Listing |
BMC Genomics
September 2023
Philip Morris International R&D, Philip Morris Products S.A, Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland.
Background: Anatabine, although being one of four major tobacco alkaloids, is never accumulated in high quantity in any of the naturally occurring species from the Nicotiana genus. Previous studies therefore focused on transgenic approaches to synthetize anatabine, most notably by generating transgenic lines with suppressed putrescine methyltransferase (PMT) activity. This led to promising results, but the global gene expression of plants with such distinct metabolism has not been analyzed.
View Article and Find Full Text PDFPlant Sci
January 2020
Department of Bioengineering, Huainan Normal University, Huainan, Anhui Province, 232038, China; Key Laboratory of Bioresource and Environmental Biotechnology of Anhui Higher Education Institutes, Huainan Normal University, Huainan, Anhui Province, 232038, China. Electronic address:
Class I TGA transcription factors (TFs) are known to participate in plant resistance responses, however, their regulatory functions in the biosynthesis of secondary metabolites were rarely revealed. In this study, a class I TGA TF, TwTGA1, from Tripterygium wilfordii Hook.f.
View Article and Find Full Text PDFMethods Mol Biol
June 2018
Graduate School of Biological Sciences, Nara Institute of Science and Technology, Takayama, 8916-5, Ikoma, Japan.
The intracellular localization of enzymes provides key information for understanding complex metabolic pathways. Based on enzyme localization data, the involvement of multiple organelles and the movement of metabolites between cellular compartments have been suggested for a number of pathways. Transient expression of fluorescently tagged proteins in the leaves of Nicotiana benthamiana through Agrobacterium infiltration is a simple and versatile way to examine the intracellular localization of proteins of interest.
View Article and Find Full Text PDFPlanta
February 2017
Department of Pharmaceutical Biology, Martin-Luther University Halle-Wittenberg, Hoher Weg 8, 06120, Halle (Saale), Germany.
Solanum tuberosum tropinone reductase I reduced tropinone in vivo. Suppression of tropinone reductase II strongly reduced calystegines in sprouts. Overexpression of putrescine N -methyltransferase did not alter calystegine accumulation.
View Article and Find Full Text PDFPlant Cell Physiol
February 2014
Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192 Japan.
Biosynthesis of nicotine in tobacco requires N-methylputrescine oxidase (MPO), which belongs to the copper-containing amine oxidase superfamily. Previous studies identified tobacco MPO1 and its close homolog NtDAO1 (formerly called MPO2), of which MPO1 has been shown preferentially to oxidize N-methylated amines. We show here that NtDAO1, as well as a homologous Arabidopsis diamine oxidase (DAO), accept non-N-methylated amines more efficiently than their corresponding N-methylated amines.
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