Nicotine Biosynthesis

Shoji, Tsubasa; Hashimoto, Takashi

doi:10.1002/9781119991311.ch7

Cited by 30 publications

(25 citation statements)

References 135 publications

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“…e ERF189-binding sites in the promoters of PMT2 and QPT2 have been extensively characterized previously (Shoji et al 2010;Shoji and Hashimoto 2011b), and this study identified new ERF189-binding sites, two elements of the identical core sequences (O3/O5) in ODC1 and ODC2, and two element (M1 and M2) in MATE1. Absence of the ERF189-binding sites in the available ADC promoter sequences is consistent with the fact that ADC is not regulated by the NIC2-locus ERF genes (Shoji et al 2010;Shoji and Hashimoto 2011a). On the other hand, it is puzzling that we did not nd any ERF189-binding sites in the jasmonate-regulated promoter region of the ERF189-regulated A622 gene (Figure 2A).…”

Section: Discussionmentioning

confidence: 54%

“…Jasmonate-or herbivoryinduced tobacco genes include structural genes encoding enzymes and transporters involved in nicotine biosynthesis and accumulation, such as ornithine decarboxylase (ODC; Imanishi et al 1998), putrescine N-methyltransferase (PMT; Hibi et al 1994), qunolinate phosphoribosyltransferase (QPT; Sinclair et al 2000), a PIP-family oxidoreductase A622 (De Boer et al 2009;Hibi et al 1994;Kajikawa et al 2009) and tonoplastlocalized multidrug and toxic compound extrusion (MATE)-type transporters MATE1 and MATE2 (Shoji et al 2009) (Figure 1). ese tobacco genes are expressed in restricted cell types in the roots, and are coordinately elicited in space and time by jasmonate (Shoji and Hashimoto 2011a).…”

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confidence: 99%

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DNA-binding and transcriptional activation properties of tobacco <i>NIC2</i>-locus ERF189 and related transcription factors

Shoji

Hashimoto

2012

Plant Biotechnology

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In tobacco (Nicotiana tabacum), several transcription factors belonging to the IXa group of APETALA2/ ETHYLENE RESPONSE FACTOR (AP2/ERF) cluster at the regulatory NIC2 locus for the leaf nicotine level, and directly activate structural genes required for nicotine biosynthesis and transport. Solanaceous Atropa and Hyoscyamus plants synthesize medicinal tropane alkaloids by utilizing enzymes that partially overlap with the nicotine pathway. We tested whether the tobacco NIC2-locus ERF189 binds to potential ERF binding sites in the promoters of various structural genes involved in biosynthesis of nicotine and tropane alkaloids by an electrophoresis mobility shi assay. ERF189 bound four new GCC-box-like sequences in three nicotine structural genes, but did not recognize other candidate binding sites. is binding preference was used to optimize the consensus binding sequence of ERF189 as 5′-(A/C)GC(A/C)NNCC(A/T)-3′. Five group IXa ERFs (tobacco ERF189, tobacco ERF163, Catharanthus ORCA3, Arabidopsis AtERF13, and Arabidopsis AtERF1) were examined whether they bind to the ERF189-recognition site in the promoter of the tobacco putrescine Nmethyltransferase gene in vitro, and transactivate the promoter in a transient expression assay using cultured tobacco cells.e more the protein sequences were similar to ERF189, the more e ective these ERFs were in these functional assays. e transient expression assay also identi ed transactivation domains in an N-terminal acidic region of ERF189, and in a C-terminal Ser-rich region of AtERF13.

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Section: Discussionmentioning

confidence: 54%

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confidence: 99%

DNA-binding and transcriptional activation properties of tobacco <i>NIC2</i>-locus ERF189 and related transcription factors

Shoji

Hashimoto

2012

Plant Biotechnology

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“…First, we measured their relative expression levels in flowers, leaves, stems, and roots of 10-week-old wild-type tobacco plants. Most structural genes for nicotine biosynthesis, including PMT ( Figure 10A), are expressed specifically in the root (Shoji and Hashimoto, 2010). All the ERF genes of clade 2 analyzed were substantially expressed in the root ( Figure 10A; see Supplemental Figure 3 online) but were also expressed in other organs, especially in the leaf.…”

Section: Nic2-locus Erf Genes Are Expressed In the Root And Induced Bmentioning

confidence: 99%

“…Nicotine is the predominant alkaloid accumulating in the leaf of most commercial tobacco varieties, whereas other related pyridine alkaloids are also present at substantial levels in tobacco roots, in elicited cultured tobacco cells, or in wild Nicotiana species (Saito et al, 1985;Shoji and Hashimoto, 2010). Nicotine is composed of a pyridine ring and a pyrrolidine ring (see Supplemental Figure 1 online); ornithine decarboxylase (ODC; Imanishi et al, 1998), putrescine N-methyltransferase (PMT; Hibi et al, 1994), and N-methylputrescine oxidase (MPO; Heim et al, 2007;Katoh et al, 2007) are involved in the formation of the pyrrolidine ring, whereas the pyridine ring uses enzymes involved in the early steps of NAD biosynthesis, such as aspartate oxidase (AO), quinolinic acid synthase (QS), and quinolinic acid phosphoribosyl transferase (QPT) (Sinclair et al, 2000;Katoh et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Clustered Transcription Factor Genes Regulate Nicotine Biosynthesis in Tobacco

2010

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Tobacco (Nicotiana tabacum) synthesizes nicotine and related pyridine alkaloids in the root, and their synthesis increases upon herbivory on the leaf via a jasmonate-mediated signaling cascade. Regulatory NIC loci that positively regulate nicotine biosynthesis have been genetically identified, and their mutant alleles have been used to breed low-nicotine tobacco varieties. Here, we report that the NIC2 locus, originally called locus B, comprises clustered transcription factor genes of an ethylene response factor (ERF) subfamily; in the nic2 mutant, at least seven ERF genes are deleted altogether. Overexpression, suppression, and dominant repression experiments using transgenic tobacco roots showed both functional redundancy and divergence among the NIC2-locus ERF genes. These transcription factors recognized a GCC-box element in the promoter of a nicotine pathway gene and specifically activated all known structural genes in the pathway. The NIC2-locus ERF genes are expressed in the root and upregulated by jasmonate with kinetics that are distinct among the members. Thus, gene duplication events generated a cluster of highly homologous transcription factor genes with transcriptional and functional diversity. The NIC2-locus ERFs are close homologs of ORCA3, a jasmonate-responsive transcriptional activator of indole alkaloid biosynthesis in Catharanthus roseus, indicating that the NIC2/ORCA3 ERF subfamily was recruited independently to regulate jasmonate-inducible secondary metabolism in distinct plant lineages.

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“…Nicotine is synthesized from the amino acids Asp and Orn (Shoji and Hashimoto, 2011a;Dewey and Xie, 2013). Early in the NAD biosynthetic pathway, Asp is metabolized to nicotinate mononucleotide, which is incorporated into the pyridine ring of nicotine by unknown enzyme reactions.…”

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Tobacco Nicotine Uptake Permease Regulates the Expression of a Key Transcription Factor Gene in the Nicotine Biosynthesis Pathway

2014

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The down-regulation of a tobacco (Nicotiana tabacum) plasma membrane-localized nicotine uptake permease, NUP1, was previously reported to reduce total alkaloid levels in tobacco plants. However, it was unclear how this nicotine transporter affected the biosynthesis of the alkaloid nicotine. When NUP1 expression was suppressed in cultured tobacco cells treated with jasmonate, which induces nicotine biosynthesis, the NICOTINE2-locus transcription factor gene ETHYLENE RESPONSE FACTOR189 (ERF189) and its target structural genes, which function in nicotine biosynthesis and transport, were strongly suppressed, resulting in decreased total alkaloid levels. Conversely, NUP1 overexpression had the opposite effect. In these experiments, the expression levels of the MYC2 transcription factor gene and its jasmonate-inducible target gene were not altered. Inhibiting tobacco alkaloid biosynthesis by suppressing the expression of genes encoding enzymes in the nicotine pathway did not affect the expression of ERF189 and other nicotine pathway genes, indicating that ERF189 is not regulated by cellular alkaloid levels. Suppressing the expression of jasmonate signaling components in cultured tobacco cells showed that NUP1 acts downstream of the CORONATINE INSENSITIVE1 receptor and MYC2, but upstream of ERF189. These results suggest that although jasmonate-activated expression of MYC2 induces the expression of both NUP1 and ERF189, expression of ERF189 may actually be mediated by NUP1. Furthermore, NUP1 overexpression in tobacco plants inhibited the long-range transport of nicotine from the roots to the aerial parts. Thus, NUP1 not only mediates the uptake of tobacco alkaloids into root cells, but also positively controls the expression of ERF189, a key gene in the biosynthesis of these alkaloids.

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Nicotine Biosynthesis

Cited by 30 publications

References 135 publications

DNA-binding and transcriptional activation properties of tobacco <i>NIC2</i>-locus ERF189 and related transcription factors

DNA-binding and transcriptional activation properties of tobacco <i>NIC2</i>-locus ERF189 and related transcription factors

Clustered Transcription Factor Genes Regulate Nicotine Biosynthesis in Tobacco

Tobacco Nicotine Uptake Permease Regulates the Expression of a Key Transcription Factor Gene in the Nicotine Biosynthesis Pathway

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