Key Enzymes of Triterpenoid Saponin Biosynthesis and the Induction of Their Activities and Gene Expressions in Plants

Zhao, Chang Ling; Cui, Xiu Ming; Chen, Yan Ping; Liang, Qi

doi:10.1177/1934578x1000500736

Cited by 36 publications

(32 citation statements)

References 75 publications

(165 reference statements)

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“…β-Amyrin synthase (β-AS) is a key enzyme that catalyzes the cyclization of epoxysqualene into a common aglycon, the first committed step in the biosynthesis of triterpenoid saponins [73], [74]. Both SE and β-AS were significantly up-regulated by DBM herbivory (Figure 9), consistent with the finding that triterpenoid saponins respond to and defend against DBM herbivory [3].…”

Section: Resultssupporting

confidence: 80%

Transcriptome Analysis of Barbarea vulgaris Infested with Diamondback Moth (Plutella xylostella) Larvae

et al. 2013

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BackgroundThe diamondback moth (DBM, Plutella xylostella) is a crucifer-specific pest that causes significant crop losses worldwide. Barbarea vulgaris (Brassicaceae) can resist DBM and other herbivorous insects by producing feeding-deterrent triterpenoid saponins. Plant breeders have long aimed to transfer this insect resistance to other crops. However, a lack of knowledge on the biosynthetic pathways and regulatory networks of these insecticidal saponins has hindered their practical application. A pyrosequencing-based transcriptome analysis of B. vulgaris during DBM larval feeding was performed to identify genes and gene networks responsible for saponin biosynthesis and its regulation at the genome level.Principal FindingsApproximately 1.22, 1.19, 1.16, 1.23, 1.16, 1.20, and 2.39 giga base pairs of clean nucleotides were generated from B. vulgaris transcriptomes sampled 1, 4, 8, 12, 24, and 48 h after onset of P. xylostella feeding and from non-inoculated controls, respectively. De novo assembly using all data of the seven transcriptomes generated 39,531 unigenes. A total of 37,780 (95.57%) unigenes were annotated, 14,399 of which were assigned to one or more gene ontology terms and 19,620 of which were assigned to 126 known pathways. Expression profiles revealed 2,016–4,685 up-regulated and 557–5188 down-regulated transcripts. Secondary metabolic pathways, such as those of terpenoids, glucosinolates, and phenylpropanoids, and its related regulators were elevated. Candidate genes for the triterpene saponin pathway were found in the transcriptome. Orthological analysis of the transcriptome with four other crucifer transcriptomes identified 592 B. vulgaris-specific gene families with a P-value cutoff of 1e−5.ConclusionThis study presents the first comprehensive transcriptome analysis of B. vulgaris subjected to a series of DBM feedings. The biosynthetic and regulatory pathways of triterpenoid saponins and other DBM deterrent metabolites in this plant were classified. The results of this study will provide useful data for future investigations on pest-resistance phytochemistry and plant breeding.

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Section: Resultssupporting

confidence: 80%

Transcriptome Analysis of Barbarea vulgaris Infested with Diamondback Moth (Plutella xylostella) Larvae

et al. 2013

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“…The pentacyclic triterpenoid SSs are considered to be synthesized using β-amyrin as a substrate via a series of reactions thought to be catalyzed by P450 s and UGT s. MeJA is known to induce the biosynthesis of many secondary metabolites, such as ginsenoside [ 47 , 48 ] and SSs [ 17 , 49 ]. MeJA also up-regulates metabolite-related enzyme genes [ 50 ]. The expression of genes involved in SS skeleton biosynthesis has not been studied in MeJA treatment experiments.…”

Section: Resultsmentioning

confidence: 99%

Transcriptome analysis of Bupleurum chinense focusing on genes involved in the biosynthesis of saikosaponins

et al. 2011

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BackgroundBupleurum chinense DC. is a widely used traditional Chinese medicinal plant. Saikosaponins are the major bioactive constituents of B. chinense, but relatively little is known about saikosaponin biosynthesis. The 454 pyrosequencing technology provides a promising opportunity for finding novel genes that participate in plant metabolism. Consequently, this technology may help to identify the candidate genes involved in the saikosaponin biosynthetic pathway.ResultsOne-quarter of the 454 pyrosequencing runs produced a total of 195, 088 high-quality reads, with an average read length of 356 bases (NCBI SRA accession SRA039388). A de novo assembly generated 24, 037 unique sequences (22, 748 contigs and 1, 289 singletons), 12, 649 (52.6%) of which were annotated against three public protein databases using a basic local alignment search tool (E-value ≤1e-10). All unique sequences were compared with NCBI expressed sequence tags (ESTs) (237) and encoding sequences (44) from the Bupleurum genus, and with a Sanger-sequenced EST dataset (3, 111). The 23, 173 (96.4%) unique sequences obtained in the present study represent novel Bupleurum genes. The ESTs of genes related to saikosaponin biosynthesis were found to encode known enzymes that catalyze the formation of the saikosaponin backbone; 246 cytochrome P450 (P450s) and 102 glycosyltransferases (GTs) unique sequences were also found in the 454 dataset. Full length cDNAs of 7 P450s and 7 uridine diphosphate GTs (UGTs) were verified by reverse transcriptase polymerase chain reaction or by cloning using 5' and/or 3' rapid amplification of cDNA ends. Two P450s and three UGTs were identified as the most likely candidates involved in saikosaponin biosynthesis. This finding was based on the coordinate up-regulation of their expression with β-AS in methyl jasmonate-treated adventitious roots and on their similar expression patterns with β-AS in various B. chinense tissues.ConclusionsA collection of high-quality ESTs for B. chinense obtained by 454 pyrosequencing is provided here for the first time. These data should aid further research on the functional genomics of B. chinense and other Bupleurum species. The candidate genes for enzymes involved in saikosaponin biosynthesis, especially the P450s and UGTs, that were revealed provide a substantial foundation for follow-up research on the metabolism and regulation of the saikosaponins.

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“…Triterpenoid saponins branch from the phytosterol pathway by alternative cyclization of the common precursor 2,3-oxidosqualene mediated by oxidosqualene cyclases (OSCs) (reviewed in Haralampidis et al, 2002;Zhao et al, 2010;Yendo et al, 2010). The A. thaliana genome contains 13 OSCs (Phillips et al, 2006;Abe, 2007).…”

Section: Resistance and Saponin Biosynthesismentioning

confidence: 99%

Barbarea vulgaris linkage map and quantitative trait loci for saponins, glucosinolates, hairiness and resistance to the herbivore Phyllotreta nemorum

et al. 2011

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Key Enzymes of Triterpenoid Saponin Biosynthesis and the Induction of Their Activities and Gene Expressions in Plants

Cited by 36 publications

References 75 publications

Transcriptome Analysis of Barbarea vulgaris Infested with Diamondback Moth (Plutella xylostella) Larvae

Transcriptome Analysis of Barbarea vulgaris Infested with Diamondback Moth (Plutella xylostella) Larvae

Transcriptome analysis of Bupleurum chinense focusing on genes involved in the biosynthesis of saikosaponins

Barbarea vulgaris linkage map and quantitative trait loci for saponins, glucosinolates, hairiness and resistance to the herbivore Phyllotreta nemorum

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