Expression and RNA Interference-Induced Silencing of the Dammarenediol Synthase Gene in Panax ginseng

Han, Jung Yeon; Kwon, Yong Soo; Yang, Deok Chun; Jung, Young Rim; Choi, Yong Eui

doi:10.1093/pcp/pcl032

Cited by 156 publications

(122 citation statements)

References 34 publications

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“…It also shows the complex and divergent adaptation characteristics of oScs in response to fungal elicitation. Similar results have also been found in other research about oScs in response to external stress (9,10,11,12,15). For example, hayashi et al (11,12) investigated the differential regulation of three oSc mRnAs by MeJA and Gibberellin A3 (GA3) in cultured Glycyrrhiza glabra cells and pointed out that MeJA upregulated β-AS mRnA and soyasaponin biosynthesis but downregulated LUS mRnA expression, and GA3 downregulated β-AS mRnA but not LUS mRnA in the cultured cells.…”

Section: Resultssupporting

confidence: 80%

Compounds ofBetula PlatyphyllaCell Suspension Cultures in Response to Fungal Elicitor

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Zhai

et al. 2013

Biotechnology & Biotechnological Equipment

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Section: Resultssupporting

confidence: 80%

Compounds ofBetula PlatyphyllaCell Suspension Cultures in Response to Fungal Elicitor

Fan

Zhai

et al. 2013

Biotechnology & Biotechnological Equipment

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“…The in planta overexpression of SlTTS1 and SlTTS2 led to increased accumulation of cuticular triterpenoids, in both cases of the same products that had also been found in yeast. This finding is very important, since most previous reports on biochemical characterizations of OSCs had relied entirely on yeast expression systems, and it had only rarely been tested whether the heterologous environment might alter the enzyme specificity (Han et al, 2006). The match between yeast and in planta expression results in this study confirms the validity of the yeast expression system, at least for the two tomato OSCs studied.…”

Section: Discussionsupporting

confidence: 73%

“…For a few plant species, more than one OSC has been characterized, so that the suite of OSCs accounted for at least part of the triterpenoid profile in those species (Morita et al, 1997Hayashi et al, 2000Hayashi et al, , 2001Iturbe-Ormaetxe et al, 2003;Sawai et al, 2006aSawai et al, , 2006b. It is generally assumed that the OSC product specificities determined in vivo in yeast would accurately reflect the true enzyme activities; however, in planta data to corroborate the specificities have only rarely been reported (Han et al, 2006) and in vitro results are missing, probably due to problems with handling the lipophilic substrate and the membrane-associated enzymes.…”

mentioning

confidence: 99%

Two Oxidosqualene Cyclases Responsible for Biosynthesis of Tomato Fruit Cuticular Triterpenoids

et al. 2010

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The first committed step in triterpenoid biosynthesis is the cyclization of epoxysqualene into various triterpene alcohol isomers, a reaction catalyzed by oxidosqualene cyclases (OSCs). The different OSCs have characteristic product specificities, which are mainly due to differences in the numbers of high-energy intermediates the enzymes can stabilize. The goal of this investigation was to clone and characterize OSCs from tomato (Solanum lycopersicum), a species known to accumulate d-amyrin in its fruit cuticular wax, in order to gain insights into the enzymatic formation of this particular triterpenoid. We used a homology-based approach to isolate two tomato OSCs and tested their biochemical properties by heterologous expression in yeast as well as overexpression in tomato. One of the enzymes was found to be a product-specific b-amyrin synthase, while the other one was a multifunctional OSC synthesizing 48% d-amyrin and six other products. The product spectra of both OSCs together account for both the range and the relative amounts of the triterpenoids found in the fruit cuticle. Both enzymes were expressed exclusively in the epidermis of the tomato fruit, indicating that their major function is to form the cuticular triterpenoids. The relative expression levels of both OSC genes, determined by quantitative reverse transcription-polymerase chain reaction, were consistent with product profiles in fruit and leaves of the tomato cultivar MicroTom. However, the transcript ratios were only partially consistent with the differences in amounts of product triterpenoids between the tomato cultivars MicroTom, M82, and Ailsa Craig; thus, transcriptional control of the two OSCs alone cannot explain the fruit triterpenoid profiles of the cultivars.

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“…Two ginsenosides Rb1 of protopanaxadiol and Rg1 of protopanaxatriol accurately weighed, were dissolved in methanol and diluted to volume with methanol, which was taken as the sample solution. Analysis of ginsenosides by HPLC was carried out as described in Han et al (2006). Quantitative analysis was performed on a one-point curve method using external standards of authentic ginsenosides.…”

Section: Rt-pcr Analysis and Ginsenoside Analysesmentioning

confidence: 99%

Regulation and differential expression of protopanaxadiol synthase in Asian and American ginseng ginsenoside biosynthesis by RNA interferences

2013

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Asian ginseng (Panax ginseng) and American ginseng (Panax quinquefolium), are thought to be representative plant of Panax species, have important commercial value and are used in worldwide. Panax species produces triterpene saponins called ginsenosides, which are classified into two groups by the skeleton of aglycones, namely dammarane-type and oleanane-type. Dammaranetype ginsenosides dominate over oleanane-type not only in amount but also in structural varieties. Researches shows that the saponins content in American ginseng is higher than that in Asian ginseng, the higher part of ginsenosides is from dammarane-type biosynthesis. It has been proposed that protopanaxadiol derived from dammarenediol-II, is a key hydroxylation by cytochrome P450 for the biosynthesis of ginsenosides, and the gene number of protopanaxadiol synthase has been published independent in Asian ginseng (PgCYP716A47). However, little is known about genes involved in hydroxylation and glycosylation in American ginseng ginsenoside biosynthesis. Here, we first cloned and identified a P450 gene named PqD12H encoding enzymes catalyzed dammarenediol-II to protopanaxadiol by RT-PCR using degenerate primers designed based on sequence homology. In vitro, the ectopic expression of PqD12H in recombinant WAT21 yeast resulted in protopanaxadiol production after dammarenediol-II was added to the culture medium. In vivo, we established both PgCYP716A47 and PqD12H RNAi transgenic. The RT-PCR and HPLC analysis of the final products of protopanaxadiol and protopanaxatriol showed a result that declined level of protopanaxadiol-type and protopanaxatriol-type ginsenosides. It suggested that the P450 synthase content or expression in American ginseng exceed than in Asian ginseng. The result elucidated the evolution relationship of P450s and the reason of different saponins content among Panax species.

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Expression and RNA Interference-Induced Silencing of the Dammarenediol Synthase Gene in Panax ginseng

Cited by 156 publications

References 34 publications

Compounds ofBetula PlatyphyllaCell Suspension Cultures in Response to Fungal Elicitor

Compounds ofBetula PlatyphyllaCell Suspension Cultures in Response to Fungal Elicitor

Two Oxidosqualene Cyclases Responsible for Biosynthesis of Tomato Fruit Cuticular Triterpenoids

Regulation and differential expression of protopanaxadiol synthase in Asian and American ginseng ginsenoside biosynthesis by RNA interferences

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