Molecular genetics of alkaloid biosynthesis in Nicotiana tabacum

• Published in: Phytochemistry (Oxford) Vol. 94; pp. 10 - 27
• Main Authors: Dewey, Ralph E., Xie, Jiahua
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2013
• Subjects: Alkaloid biosynthetic genes; Alkaloids; Alkaloids - biosynthesis; Alkaloids - chemistry; anabasine; biochemical pathways; biosynthesis; Biosynthetic Pathways; Biosynthetic Pathways - genetics; chemistry; enzymes; enzymology; Gene Expression Regulation, Plant; genes; genetics; leaves; metabolism; Methyltransferases; Methyltransferases - genetics; Methyltransferases - metabolism; molecular biology; Molecular Structure; Nicotiana - enzymology; Nicotiana - genetics; Nicotiana - metabolism; Nicotiana tabacum; Nicotine; Nicotine - biosynthesis; Nicotine - chemistry; Nitrosamines; Nitrosamines - metabolism; Nornicotine; Plant Proteins; Plant Proteins - genetics; Plant Proteins - metabolism; Pyridines; Pyridines - chemistry; secondary metabolites; Solanaceae; tobacco; Tobacco-specific nitrosamines; transcription (genetics); ADC; NAT; JAZ; NND; NS; MAPKK; NNK; MeJA; Nicotiana tabacum; BBL; MPO; bHLH; NNN; ODC; QPT; TSNA; Solanaceae; RNAi; DMN; MATE; NaNG; NUP; MTHFR; NAB; PON; NAMN; Alkaloid biosynthetic genes; Nornicotine; PMT; Tobacco-specific nitrosamines; JA; ERF; Nicotine; nicotinic acid ß-N-glucoside; putrescine methyltransferase; methyl jasmonate; ornithine decarboxylase; tobacco-specific nitrosamine; arginine decarboxylase; N-nitrosoanabasine; nicotine uptake permease; methylenetetrahydrofolate reductase; N-methylputrescine oxidase; jasmonate ZIM-domain; nicotinic acid mononucleotide; mitogen-activated protein kinase kinase; N-nitrosoanatabine; multidrug and toxic compound extrusion; basic helix–loop–helix; RNA interference; dihydrometanicotine; ethylene response factor; N-nitrosonornicotine; jasmonic acid; pseudooxynicotine; berberine bridge enzyme-like; 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone; quinolinate phosphoribosyltransferase; nicotine N-demethylase; nicotine synthase
• ISSN: 0031-9422; 1873-3700; 1873-3700
• DOI: 10.1016/j.phytochem.2013.06.002

Recent advances in the molecular genetics of pyridine alkaloid production and regulation in Nicotiana tabacum are reviewed. •The pyridine alkaloids of tobacco have been the subject of intensive investigation.•Nature and function of tobacco alkaloid biosynthetic pathway genes are reviewed.•Model for the transcriptional regulation of nicotine biosynthesis is described.•Rationales for altering the alkaloid composition of tobacco are discussed. Alkaloids represent an extensive group of nitrogen-containing secondary metabolites that are widely distributed throughout the plant kingdom. The pyridine alkaloids of tobacco (Nicotiana tabacum L.) have been the subject of particularly intensive investigation, driven largely due to the widespread use of tobacco products by society and the role that nicotine (16) (see Fig. 1) plays as the primary compound responsible for making the consumption of these products both pleasurable and addictive. In a typical commercial tobacco plant, nicotine (16) comprises about 90% of the total alkaloid pool, with the alkaloids nornicotine (17) (a demethylated derivative of nicotine), anatabine (15) and anabasine (5) making up most of the remainder. Advances in molecular biology have led to the characterization of the majority of the genes encoding the enzymes directly responsible the biosynthesis of nicotine (16) and nornicotine (17), while notable gaps remain within the anatabine (15) and anabasine (5) biosynthetic pathways. Several of the genes involved in the transcriptional regulation and transport of nicotine (16) have also been elucidated. Investigations of the molecular genetics of tobacco alkaloids have not only provided plant biologists with insights into the mechanisms underlying the synthesis and accumulation of this important class of plant alkaloids, they have also yielded tools and strategies for modifying the tobacco alkaloid composition in a manner that can result in changing the levels of nicotine (16) within the leaf, or reducing the levels of a potent carcinogenic tobacco-specific nitrosamine (TSNA). This review summarizes recent advances in our understanding of the molecular genetics of alkaloid biosynthesis in tobacco, and discusses the potential for applying information accrued from these studies toward efforts designed to help mitigate some of the negative health consequences associated with the use of tobacco products.