Jasmonate Induction of Putrescine N-Methyltransferase Genes in the Root of Nicotiana sylvestris

Shoji, Tsubasa; Yamada, Yasuyuki; Hashimoto, Takashi

doi:10.1093/pcp/pcd001

Cited by 174 publications

(138 citation statements)

References 55 publications

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“…First, we analysed ORC1 expression in whole organs of hydroponically grown plants. Consistent with nicotine biosynthesis taking place in the roots of tobacco plants, the key biosynthetic genes PMT and QPRT are preferentially transcribed in root tissues (Shoji et al, 2000;Sinclair et al, 2000;Cane et al, 2005). In mock conditions, ORC1 transcript levels were lower in the leaves than in the roots (Figure 2).…”

Section: Orc1 Stimulates Nicotine Biosynthesis In Nicotiana Speciesmentioning

confidence: 70%

APETALA2/ETHYLENE RESPONSE FACTOR and basic helix–loop–helix tobacco transcription factors cooperatively mediate jasmonate‐elicited nicotine biosynthesis

et al. 2011

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SUMMARYTranscription factors of the plant-specific apetala2/ethylene response factor (AP2/ERF) family control plant secondary metabolism, often as part of signalling cascades induced by jasmonate (JA) or other elicitors. Here, we functionally characterized the JA-inducible tobacco (Nicotiana tabacum) AP2/ERF factor ORC1, one of the members of the NIC2-locus ERFs that control nicotine biosynthesis and a close homologue of ORCA3, a transcriptional activator of alkaloid biosynthesis in Catharanthus roseus. ORC1 positively regulated the transcription of several structural genes coding for the enzymes involved in nicotine biosynthesis. Accordingly, overexpression of ORC1 was sufficient to stimulate alkaloid biosynthesis in tobacco plants and tree tobacco (Nicotiana glauca) root cultures. In contrast to ORCA3 in C. roseus, which needs only the GCC motif in the promoters of the alkaloid synthesis genes to induce their expression, ORC1 required the presence of both GCC-motif and G-box elements in the promoters of the tobacco nicotine biosynthesis genes for maximum transactivation. Correspondingly, combined application with the JA-inducible Nicotiana basic helix-loop-helix (bHLH) factors that bind the G-box element in these promoters enhanced ORC1 action. Conversely, overaccumulation of JAZ repressor proteins that block bHLH activity reduced ORC1 functionality. Finally, the activity of both ORC1 and bHLH proteins was post-translationally upregulated by a JA-modulated phosphorylation cascade, in which a specific mitogen-activated protein kinase kinase, JA-factor stimulating MAPKK1 (JAM1), was identified. This study highlights the complexity of the molecular machinery involved in the regulation of tobacco alkaloid biosynthesis and provides mechanistic insights about its transcriptional regulators.

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Section: Orc1 Stimulates Nicotine Biosynthesis In Nicotiana Speciesmentioning

confidence: 70%

APETALA2/ETHYLENE RESPONSE FACTOR and basic helix–loop–helix tobacco transcription factors cooperatively mediate jasmonate‐elicited nicotine biosynthesis

et al. 2011

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“…As much as 60 mM of nicotine accumulates in the vacuoles of the leaf epidermal cells at the tip (Lochmann et al, 2001). Putrescine N-methyltransferase (PMT) catalyzes the first committed step in the nicotine-specific pathway, and a PIP-family reductase, called A622, was also suggested to function in a late step in nicotine biosynthesis (Hibi et al, 1994;Shoji et al, 2000aShoji et al, , 2000bDeBoer et al, 2009;Kajikawa et al, 2009). PMT and A622 proteins are specifically expressed in the same cell types in the root (Shoji et al, 2000a(Shoji et al, , 2002.…”

mentioning

confidence: 99%

Multidrug and Toxic Compound Extrusion-Type Transporters Implicated in Vacuolar Sequestration of Nicotine in Tobacco Roots

et al. 2008

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Nicotine is a major alkaloid accumulating in the vacuole of tobacco (Nicotiana tabacum), but the transporters involved in the vacuolar sequestration are not known. We here report that tobacco genes (NtMATE1 and NtMATE2) encoding transporters of the multidrug and toxic compound extrusion (MATE) family are coordinately regulated with structural genes for nicotine biosynthesis in the root, with respect to spatial expression patterns, regulation by NIC regulatory loci, and induction by methyl jasmonate. Subcellular fractionation, immunogold electron microscopy, and expression of a green fluorescent protein fusion protein all suggested that these transporters are localized to the vacuolar membrane. Reduced expression of the transporters rendered tobacco plants more sensitive to the application of nicotine. In contrast, overexpression of NtMATE1 in cultured tobacco cells induced strong acidification of the cytoplasm after jasmonate elicitation or after the addition of nicotine under nonelicited conditions. Expression of NtMATE1 in yeast (Saccharomyces cerevisiae) cells compromised the accumulation of exogenously supplied nicotine into the yeast cells. The results imply that these MATE-type proteins transport tobacco alkaloids from the cytosol into the vacuole in exchange for protons in alkaloid-synthesizing root cells.

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“…Low but substantial expression of NUP1 was also observed in the leaf and stem of tobacco plants, although NUP1-expressing cell types were not identified in the aerial organs in this study. These spatial expression patterns of NUP1 in tobacco roots are distinct from those of known enzyme genes involved in nicotine biosynthesis, which are strongly expressed in the root cortex and not in the aerial parts (Shoji et al, 2000(Shoji et al, , 2002Kajikawa et al, 2011;Shoji and Hashimoto, 2011b). Tobacco MATE1/MATE2 genes, whose products sequester nicotine into the vacuole during active alkaloid biosynthesis, are also expressed in the root cortex, in a similar pattern as nicotine enzyme genes (Shoji et al, 2009).…”

Section: Nup1 Is Expressed In Root Epidermal Cellsmentioning

confidence: 96%

“…GUS activity was detected histochemically and cross sections of roots were prepared as described previously (Shoji et al, 2000). GUS-stained cultured roots were rinsed with 20 mM phosphate buffer, pH 7.0, embedded in 5% (w/v) agar containing 1 mM dithiothreitol and 20 mM phosphate buffer (pH 7.0), and sliced into 75-to 100-mm-thick cross sections using a microslicer (DTK-1500; Dohan EM).…”

Section: Histochemical Gus Assaymentioning

confidence: 99%

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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Jasmonate Induction of Putrescine N-Methyltransferase Genes in the Root of Nicotiana sylvestris

Cited by 174 publications

References 55 publications

APETALA2/ETHYLENE RESPONSE FACTOR and basic helix–loop–helix tobacco transcription factors cooperatively mediate jasmonate‐elicited nicotine biosynthesis

APETALA2/ETHYLENE RESPONSE FACTOR and basic helix–loop–helix tobacco transcription factors cooperatively mediate jasmonate‐elicited nicotine biosynthesis

Multidrug and Toxic Compound Extrusion-Type Transporters Implicated in Vacuolar Sequestration of Nicotine in Tobacco Roots

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

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