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Banerjee A, Hamberger B. P450s controlling metabolic bifurcations in plant terpene specialized metabolism. PHYTOCHEMISTRY REVIEWS : PROCEEDINGS OF THE PHYTOCHEMICAL SOCIETY OF EUROPE 2018; 17:81-111. [PMID: 29563859 PMCID: PMC5842272 DOI: 10.1007/s11101-017-9530-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 08/20/2017] [Indexed: 05/18/2023]
Abstract
ABSTRACT Catalyzing stereo- and regio-specific oxidation of inert hydrocarbon backbones, and a range of more exotic reactions inherently difficult in formal chemical synthesis, cytochromes P450 (P450s) offer outstanding potential for biotechnological engineering. Plants and their dazzling diversity of specialized metabolites have emerged as rich repository for functional P450s with the advances of deep transcriptomics and genome wide discovery. P450s are of outstanding interest for understanding chemical diversification throughout evolution, for gaining mechanistic insights through the study of their structure-function relationship, and for exploitation in Synthetic Biology. In this review, we highlight recent developments and examples in the discovery of plant P450s involved in the biosynthesis of industrially relevant monoterpenoids, sesquiterpenoids, diterpenoids and triterpenoids, throughout 2016 and early 2017. Examples were selected to illustrate the spectrum of value from commodity chemicals, flavor and fragrance compounds to pharmacologically active terpenoids. We focus on a recently emerging theme, where P450s control metabolic bifurcations and chemical diversity of the final product profile, either within a pathway, or through neo-functionalization in related species. The implications may inform approaches for rational assembly of recombinant pathways, biotechnological production of high value terpenoids and generation of novel chemical entities.
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Affiliation(s)
- Aparajita Banerjee
- Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI 48824 USA
| | - Björn Hamberger
- Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI 48824 USA
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Meyer J, Berger DK, Christensen SA, Murray SL. RNA-Seq analysis of resistant and susceptible sub-tropical maize lines reveals a role for kauralexins in resistance to grey leaf spot disease, caused by Cercospora zeina. BMC PLANT BIOLOGY 2017; 17:197. [PMID: 29132306 PMCID: PMC5683525 DOI: 10.1186/s12870-017-1137-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 10/18/2017] [Indexed: 05/20/2023]
Abstract
BACKGROUND Cercospora zeina is a foliar pathogen responsible for maize grey leaf spot in southern Africa that negatively impacts maize production. Plants use a variety of chemical and structural mechanisms to defend themselves against invading pathogens such as C. zeina, including the production of secondary metabolites with antimicrobial properties. In maize, a variety of biotic and abiotic stressors induce the accumulation of the terpenoid phytoalexins, zealexins and kauralexins. RESULTS C. zeina-susceptible line displayed pervasive rectangular grey leaf spot lesions, running parallel with the leaf veins in contrast to C. zeina-resistant line that had restricted disease symptoms. Analysis of the transcriptome of both lines indicated that genes involved in primary and secondary metabolism were up-regualted, and although different pathways were prioritized in each line, production of terpenoid compounds were common to both. Targeted phytoalexin analysis revealed that C. zeina-inoculated leaves accumulated zealexins and kauralexins. The resistant line shows a propensity toward accumulation of the kauralexin B series metabolites in response to infection, which contrasts with the susceptible line that preferentially accumulates the kauralexin A series. Kauralexin accumulation was correlated to expression of the kauralexin biosynthetic gene, ZmAn2 and a candidate biosynthetic gene, ZmKSL2. We report the expression of a putative copalyl diphosphate synthase gene that is induced by C. zeina in the resistant line exclusively. DISCUSSION This study shows that zealexins and kauralexins, and expression of their biosynthetic genes, are induced by C. zeina in both resistant and susceptible germplasm adapted to the southern African climate. The data presented here indicates that different forms of kauralexins accumulate in the resistant and susceptible maize lines in response to C. zeina, with the accumulation of kauralexin B compounds in a resistant maize line and kauralexin A compounds accumulating in the susceptible line.
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Affiliation(s)
- Jacqueline Meyer
- Department of Plant and Soil Sciences, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P/Bag X20, Hatfield, Gauteng, 0028, South Africa
- Centre for Proteomic and Genomic Research, Upper Level, St Peter's Mall, Cnr Anzio and Main Road, Observatory, Cape Town, 7925, South Africa
| | - Dave K Berger
- Department of Plant and Soil Sciences, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P/Bag X20, Hatfield, Gauteng, 0028, South Africa
| | - Shawn A Christensen
- Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, Chemistry Research Unit, Gainesville, Florida, 32608, USA
| | - Shane L Murray
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch, Cape Town, 7701, South Africa.
- Centre for Proteomic and Genomic Research, Upper Level, St Peter's Mall, Cnr Anzio and Main Road, Observatory, Cape Town, 7925, South Africa.
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Horie K, Inoue Y, Sakai M, Yao Q, Tanimoto Y, Koga J, Toshima H, Hasegawa M. Identification of UV-Induced Diterpenes Including a New Diterpene Phytoalexin, Phytocassane F, from Rice Leaves by Complementary GC/MS and LC/MS Approaches. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:4050-4059. [PMID: 25865436 DOI: 10.1021/acs.jafc.5b00785] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Rice phytoalexins are regarded as one of the most important weapons against pathogenic microorganisms. We attempted to identify novel phytoalexins and their derivatives using GC/MS and LC/MS analyses. Diterpene derivatives, 9β-pimara-7,15-diene-3β,6β,19-triol, 1, stemar-13-en-2α-ol, 2, and 1α,2α-dihydroxy-ent-12,15-cassadiene-3,11-dione, 3, were isolated from UV-irradiated rice leaves by chromatographic methods. These structures were confirmed by 1D- and 2D-NMR and MS analyses. Interestingly, all three compounds were accumulated following an infection by the rice blast pathogen Magnaporthe oryzae. Compounds 1 and 2 exhibited weak antifungal activity and may be the biosynthetic intermediates of rice phytoalexins momilactones and oryzalexin S, respectively. Compound 3 exhibited relatively high inhibitory activity against the fungal mycelial growth of M. oryzae to the same extent as the known phytoalexin phytocassane A. We conclude that 3 is a member of the cassane-type phytoalexin family and propose the name phytocassane F.
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Affiliation(s)
- Kiyotaka Horie
- †United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Yasuno Inoue
- ‡College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Inashiki, Ibaraki 300-0393, Japan
| | - Miki Sakai
- ‡College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Inashiki, Ibaraki 300-0393, Japan
| | - Qun Yao
- ‡College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Inashiki, Ibaraki 300-0393, Japan
| | - Yosuke Tanimoto
- ‡College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Inashiki, Ibaraki 300-0393, Japan
| | - Jinichiro Koga
- §Department of Biosciences, Teikyo University, 1-1 Toyosatodai, Utsunomiya, Tochigi 320-8551, Japan
| | - Hiroaki Toshima
- †United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
- ‡College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Inashiki, Ibaraki 300-0393, Japan
| | - Morifumi Hasegawa
- †United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
- ‡College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Inashiki, Ibaraki 300-0393, Japan
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Schmelz EA, Huffaker A, Sims JW, Christensen SA, Lu X, Okada K, Peters RJ. Biosynthesis, elicitation and roles of monocot terpenoid phytoalexins. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 79:659-78. [PMID: 24450747 DOI: 10.1111/tpj.12436] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Revised: 12/22/2013] [Accepted: 01/10/2014] [Indexed: 05/07/2023]
Abstract
A long-standing goal in plant research is to optimize the protective function of biochemical agents that impede pest and pathogen attack. Nearly 40 years ago, pathogen-inducible diterpenoid production was described in rice, and these compounds were shown to function as antimicrobial phytoalexins. Using rice and maize as examples, we discuss recent advances in the discovery, biosynthesis, elicitation and functional characterization of monocot terpenoid phytoalexins. The recent expansion of known terpenoid phytoalexins now includes not only the labdane-related diterpenoid superfamily but also casbane-type diterpenoids and β-macrocarpene-derived sequiterpenoids. Biochemical approaches have been used to pair pathway precursors and end products with cognate biosynthetic genes. The number of predicted terpenoid phytoalexins is expanding through advances in cereal genome annotation and terpene synthase characterization that likewise enable discoveries outside the Poaceae. At the cellular level, conclusive evidence now exists for multiple plant receptors of fungal-derived chitin elicitors, phosphorylation of membrane-associated signaling complexes, activation of mitogen-activated protein kinase, involvement of phytohormone signals, and the existence of transcription factors that mediate the expression of phytoalexin biosynthetic genes and subsequent accumulation of pathway end products. Elicited production of terpenoid phytoalexins exhibit additional biological functions, including root exudate-mediated allelopathy and insect antifeedant activity. Such findings have encouraged consideration of additional interactions that blur traditionally discrete phytoalexin classifications. The establishment of mutant collections and increasing ease of genetic transformation assists critical examination of further biological roles. Future research directions include examination of terpenoid phytoalexin precursors and end products as potential signals mediating plant physiological processes.
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Affiliation(s)
- Eric A Schmelz
- Center for Medical, Agricultural, and Veterinary Entomology, US Department of Agriculture, Agricultural Research Service, Chemistry Research Unit, Gainesville, FL, 32608, USA
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Biosynthesis of Phytoalexins and Regulatory Mechanisms of It in Rice. Biosci Biotechnol Biochem 2014; 77:1141-8. [DOI: 10.1271/bbb.130109] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Park HL, Lee SW, Jung KH, Hahn TR, Cho MH. Transcriptomic analysis of UV-treated rice leaves reveals UV-induced phytoalexin biosynthetic pathways and their regulatory networks in rice. PHYTOCHEMISTRY 2013; 96:57-71. [PMID: 24035516 DOI: 10.1016/j.phytochem.2013.08.012] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 08/08/2013] [Accepted: 08/20/2013] [Indexed: 05/13/2023]
Abstract
Rice produces diterpenoid and flavonoid phytoalexins for defense against pathogen attack. The production of phytoalexins in rice is also induced by UV-irradiation. To understand the metabolic networks involved in UV-induced phytoalexin biosynthesis and their regulation, phytochemical and transcriptomic analyses of UV-treated rice leaves were performed. In response to UV treatment, the accumulation of flavonoids was observed in rice leaves, which may serve as antioxidants against UV-induced oxidative stress. The phytochemical analysis confirmed sakuranetin accumulation and also demonstrated the induction of phenylamide synthesis in rice leaves by UV-irradiation. Transcriptomic analysis established that aromatic amino acid biosynthetic genes were immediately up-regulated after UV treatment. The genes involved in the phenylpropanoid pathway and flavonoid biosynthesis were also up-regulated. These findings suggest that the aromatic amino acid and flavonoid biosynthetic pathways are coordinately activated for the production of flavonoids and phenolic phytoalexins such as sakuranetin and phenylamides. An in silico analysis of UV-induced O-methyltransferase and acyltransferase genes suggested that these genes may be implicated in sakuranetin and phenylamide synthesis, respectively. The transcriptomic analysis also showed up-regulation of both methylerythritol phosphate pathway and the diterpenoid phytoalexin biosynthetic genes in response to UV treatment. A functional gene network analysis of phytoalexin biosynthetic and UV-induced genes for signaling components and transcription factors using RiceNet suggested that regulatory networks comprising signal perceiving receptor kinases, G-proteins, signal transducing mitogen-activated protein kinases and calcium signaling components, and transcription factors control flavonoid and phytoalexin biosynthesis in rice leaves under UV-C stress conditions.
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Affiliation(s)
- Hye Lin Park
- Graduate School of Biotechnology, Kyung Hee University, Yongin 446-701, Republic of Korea
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Picking sides: distinct roles for CYP76M6 and CYP76M8 in rice oryzalexin biosynthesis. Biochem J 2013; 454:209-16. [PMID: 23795884 DOI: 10.1042/bj20130574] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 06/24/2013] [Accepted: 06/25/2013] [Indexed: 11/17/2022]
Abstract
Natural products biosynthesis often requires the action of multiple CYPs (cytochromes P450), whose ability to introduce oxygen, increasing solubility, is critical for imparting biological activity. In previous investigations of rice diterpenoid biosynthesis, we characterized CYPs that catalyse alternative hydroxylation of ent-sandaracopimaradiene, the precursor to the rice oryzalexin antibiotic phytoalexins. In particular, CYP76M5, CYP76M6 and CYP76M8 were all shown to carry out C-7β hydroxylation, whereas CYP701A8 catalyses C-3α hydroxylation, with oxy groups found at both positions in oryzalexins A-D, suggesting that these may act consecutively in oryzalexin biosynthesis. In the present paper, we report that, although CYP701A8 only poorly reacts with 7β-hydroxy-ent-sandaracopimaradiene, CYP76M6 and CYP76M8 readily react with 3α-hydroxy-ent-sandaracopimaradiene. Notably, their activity yields distinct products, resulting from hydroxylation at C-9β by CYP76M6 or C-7β by CYP76M8, on different sides of the core tricyclic ring structure. Thus CYP76M6 and CYP76M8 have distinct non-redundant roles in orzyalexin biosynthesis. Moreover, the resulting 3α,7β- and 3α,9β-diols correspond to oryzalexins D and E respectively. Accordingly, the results of the present study complete the functional identification of the biosynthetic pathway underlying the production of these bioactive phytoalexins. In addition, the altered regiochemistry catalysed by CYP76M6 following C-3α hydroxylation has some implications for its active-site configuration, offering further molecular insight.
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9
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Wang Q, Hillwig ML, Wu Y, Peters RJ. CYP701A8: a rice ent-kaurene oxidase paralog diverted to more specialized diterpenoid metabolism. PLANT PHYSIOLOGY 2012; 158:1418-25. [PMID: 22247270 PMCID: PMC3291257 DOI: 10.1104/pp.111.187518] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 01/10/2012] [Indexed: 05/20/2023]
Abstract
All higher plants contain an ent-kaurene oxidase (KO), as such a cytochrome P450 (CYP) 701 family member is required for gibberellin (GA) phytohormone biosynthesis. While gene expansion and functional diversification of GA-biosynthesis-derived diterpene synthases into more specialized metabolism has been demonstrated, no functionally divergent KO/CYP701 homologs have been previously identified. Rice (Oryza sativa) contains five CYP701A subfamily members in its genome, despite the fact that only one (OsKO2/CYP701A6) is required for GA biosynthesis. Here we demonstrate that one of the other rice CYP701A subfamily members, OsKOL4/CYP701A8, does not catalyze the prototypical conversion of the ent-kaurene C4α-methyl to a carboxylic acid, but instead carries out hydroxylation at the nearby C3α position in a number of related diterpenes. In particular, under conditions where OsKO2 catalyzes the expected conversion of ent-kaurene to ent-kaurenoic acid required for GA biosynthesis, OsKOL4 instead efficiently reacts with ent-sandaracopimaradiene and ent-cassadiene to produce the corresponding C3α-hydroxylated diterpenoids. These compounds are expected intermediates in biosynthesis of the oryzalexin and phytocassane families of rice antifungal phytoalexins, respectively, and can be detected in rice plants under the appropriate conditions. Thus, it appears that OsKOL4 plays a role in the more specialized diterpenoid metabolism of rice, and our results provide evidence for divergence of a KO/CYP701 family member from GA biosynthesis. This further expands the range of enzymes recruited from the ancestral GA primary pathway to the more complex and specialized labdane-related diterpenoid metabolic network found in rice.
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10
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Wang Q, Hillwig ML, Okada K, Yamazaki K, Wu Y, Swaminathan S, Yamane H, Peters RJ. Characterization of CYP76M5-8 indicates metabolic plasticity within a plant biosynthetic gene cluster. J Biol Chem 2012; 287:6159-68. [PMID: 22215681 DOI: 10.1074/jbc.m111.305599] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Recent reports have revealed genomic clustering of enzymatic genes for particular biosynthetic pathways in plant specialized/secondary metabolism. Rice (Oryza sativa) carries two such clusters for production of antimicrobial diterpenoid phytoalexins, with the cluster on chromosome 2 containing four closely related/homologous members of the cytochrome P450 CYP76M subfamily (CYP76M5-8). Notably, the underlying evolutionary expansion of these CYP appears to have occurred after assembly of the ancestral biosynthetic gene cluster, suggesting separate roles. It has been demonstrated that CYP76M7 catalyzes C11α-hydroxylation of ent-cassadiene, and presumably mediates an early step in biosynthesis of the derived phytocassane class of phytoalexins. Here we report biochemical characterization of CYP76M5, -6, and -8. Our results indicate that CYP76M8 is a multifunctional/promiscuous hydroxylase, with CYP76M5 and -7 seeming to provide only redundant activity, while CYP76M6 seems to provide both redundant and novel activity, relative to CYP76M8. RNAi-mediated double knockdown of CYP76M7 and -8 suppresses elicitor inducible phytocassane production, indicating a role for these monooxygenases in phytocassane biosynthesis. In addition, our data suggests that CYP76M5, -6, and -8 may play redundant roles in production of the oryzalexin class of phytoalexins as well. Intriguingly, the preceding diterpene synthase for oryzalexin biosynthesis, unlike that for the phytocassanes, is not found in the chromosome 2 diterpenoid biosynthetic gene cluster. Accordingly, our results not only uncover a complex evolutionary history, but also further suggest some intriguing differences between plant biosynthetic gene clusters and the seemingly similar microbial operons. The implications for the underlying metabolic evolution of plants are then discussed.
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Affiliation(s)
- Qiang Wang
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
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Swaminathan S, Morrone D, Wang Q, Fulton DB, Peters RJ. CYP76M7 is an ent-cassadiene C11alpha-hydroxylase defining a second multifunctional diterpenoid biosynthetic gene cluster in rice. THE PLANT CELL 2009; 21:3315-25. [PMID: 19825834 PMCID: PMC2782285 DOI: 10.1105/tpc.108.063677] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 09/01/2009] [Accepted: 09/30/2009] [Indexed: 05/18/2023]
Abstract
Biosynthetic gene clusters are common in microbial organisms, but rare in plants, raising questions regarding the evolutionary forces that drive their assembly in multicellular eukaryotes. Here, we characterize the biochemical function of a rice (Oryza sativa) cytochrome P450 monooxygenase, CYP76M7, which seems to act in the production of antifungal phytocassanes and defines a second diterpenoid biosynthetic gene cluster in rice. This cluster is uniquely multifunctional, containing enzymatic genes involved in the production of two distinct sets of phytoalexins, the antifungal phytocassanes and antibacterial oryzalides/oryzadiones, with the corresponding genes being subject to distinct transcriptional regulation. The lack of uniform coregulation of the genes within this multifunctional cluster suggests that this was not a primary driving force in its assembly. However, the cluster is dedicated to specialized metabolism, as all genes in the cluster are involved in phytoalexin metabolism. We hypothesize that this dedication to specialized metabolism led to the assembly of the corresponding biosynthetic gene cluster. Consistent with this hypothesis, molecular phylogenetic comparison demonstrates that the two rice diterpenoid biosynthetic gene clusters have undergone independent elaboration to their present-day forms, indicating continued evolutionary pressure for coclustering of enzymatic genes encoding components of related biosynthetic pathways.
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Shimura K, Okada A, Okada K, Jikumaru Y, Ko KW, Toyomasu T, Sassa T, Hasegawa M, Kodama O, Shibuya N, Koga J, Nojiri H, Yamane H. Identification of a biosynthetic gene cluster in rice for momilactones. J Biol Chem 2007; 282:34013-8. [PMID: 17872948 DOI: 10.1074/jbc.m703344200] [Citation(s) in RCA: 192] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rice diterpenoid phytoalexins such as momilactones and phytocassanes are produced in suspension-cultured rice cells treated with a chitin oligosaccharide elicitor and in rice leaves irradiated with UV light. The common substrate geranylgeranyl diphosphate is converted into diterpene hydrocarbon precursors via a two-step sequential cyclization and then into the bioactive phytoalexins via several oxidation steps. It has been suggested that microsomal cytochrome P-450 monooxygenases (P-450s) are involved in the downstream oxidation of the diterpene hydrocarbons leading to the phytoalexins and that a dehydrogenase is involved in momilactone biosynthesis. However, none of the enzymes involved in the downstream oxidation of the diterpene hydrocarbons have been identified. In this study, we found that a putative dehydrogenase gene (AK103462) and two functionally unknown P-450 genes (CYP99A2 and CYP99A3) form a chitin oligosaccharide elicitor- and UV-inducible gene cluster, together with OsKS4 and OsCyc1, the diterpene cyclase genes involved in momilactone biosynthesis. Functional analysis by heterologous expression in Escherichia coli followed by enzyme assays demonstrated that the AK103462 protein catalyzes the conversion of 3beta-hydroxy-9betaH-pimara-7,15-dien-19,6beta-olide into momilactone A. The double knockdown of CYP99A2 and CYP99A3 specifically suppressed the elicitor-inducible production of momilactones, strongly suggesting that CYP99A2, CYP99A3, or both are involved in momilactone biosynthesis. These results provide strong evidence for the presence on chromosome 4 of a gene cluster involved in momilactone biosynthesis.
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Affiliation(s)
- Kazuhiro Shimura
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
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Okada A, Shimizu T, Okada K, Kuzuyama T, Koga J, Shibuya N, Nojiri H, Yamane H. Elicitor induced activation of the methylerythritol phosphate pathway toward phytoalexins biosynthesis in rice. PLANT MOLECULAR BIOLOGY 2007; 65:177-87. [PMID: 17634747 DOI: 10.1007/s11103-007-9207-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Accepted: 06/30/2007] [Indexed: 05/16/2023]
Abstract
Diterpenoid phytoalexins such as momilactones and phytocassanes are produced via geranylgeranyl diphosphate in suspension-cultured rice cells after treatment with a chitin elicitor. We have previously shown that the production of diterpene hydrocarbons leading to phytoalexins and the expression of related biosynthetic genes are activated in suspension-cultured rice cells upon elicitor treatment. To better understand the elicitor-induced activation of phytoalexin biosynthesis, we conducted microarray analysis using suspension-cultured rice cells collected at various times after treatment with chitin elicitor. Hierarchical cluster analysis revealed two types of early-induced expression (EIE-1, EIE-2) nodes and a late-induced expression (LIE) node that includes genes involved in phytoalexins biosynthesis. The LIE node contains genes that may be responsible for the methylerythritol phosphate (MEP) pathway, a plastidic biosynthetic pathway for isopentenyl diphosphate, an early precursor of phytoalexins. The elicitor-induced expression of these putative MEP pathway genes was confirmed by quantitative reverse-transcription PCR. 1-Deoxy-D: -xylulose 5-phosphate synthase (DXS), 1-deoxy-D: -xylulose 5-phosphate reductoisomerase (DXR), and 4-(cytidine 5'-diphospho)-2-C-methyl-D: -erythritol synthase (CMS), which catalyze the first three committed steps in the MEP pathway, were further shown to have enzymatic activities that complement the growth of E. coli mutants disrupted in the corresponding genes. Application of ketoclomazone and fosmidomycin, inhibitors of DXS and DXR, respectively, repressed the accumulation of diterpene-type phytoalexins in suspension cells treated with chitin elicitor. These results suggest that activation of the MEP pathway is required to supply sufficient terpenoid precursors for the production of phytoalexins in infected rice plants.
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Affiliation(s)
- Atsushi Okada
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Tokyo, Japan
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14
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Sakamoto T, Miura K, Itoh H, Tatsumi T, Ueguchi-Tanaka M, Ishiyama K, Kobayashi M, Agrawal GK, Takeda S, Abe K, Miyao A, Hirochika H, Kitano H, Ashikari M, Matsuoka M. An overview of gibberellin metabolism enzyme genes and their related mutants in rice. PLANT PHYSIOLOGY 2004; 134:1642-53. [PMID: 15075394 PMCID: PMC419838 DOI: 10.1104/pp.103.033696] [Citation(s) in RCA: 447] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2003] [Revised: 12/23/2003] [Accepted: 01/09/2004] [Indexed: 05/18/2023]
Abstract
To enhance our understanding of GA metabolism in rice (Oryza sativa), we intensively screened and identified 29 candidate genes encoding the following GA metabolic enzymes using all available rice DNA databases: ent-copalyl diphosphate synthase (CPS), ent-kaurene synthase (KS), ent-kaurene oxidase (KO), ent-kaurenoic acid oxidase (KAO), GA 20-oxidase (GA20ox), GA 3-oxidase (GA3ox), and GA 2-oxidase (GA2ox). In contrast to the Arabidopsis genome, multiple CPS-like, KS-like, and KO-like genes were identified in the rice genome, most of which are contiguously arranged. We also identified 18 GA-deficient rice mutants at six different loci from rice mutant collections. Based on the mutant and expression analyses, we demonstrated that the enzymes catalyzing the early steps in the GA biosynthetic pathway (i.e. CPS, KS, KO, and KAO) are mainly encoded by single genes, while those for later steps (i.e. GA20ox, GA3ox, and GA2ox) are encoded by gene families. The remaining CPS-like, KS-like, and KO-like genes were likely to be involved in the biosynthesis of diterpene phytoalexins rather than GAs because the expression of two CPS-like and three KS-like genes (OsCPS2, OsCPS4, OsKS4, OsKS7, and OsKS8) were increased by UV irradiation, and four of these genes (OsCPS2, OsCPS4, OsKS4, and OsKS7) were also induced by an elicitor treatment.
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Affiliation(s)
- Tomoaki Sakamoto
- Field Production Science Center, University of Tokyo, Nishi-Tokyo, Tokyo 188-0002, Japan
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15
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Affiliation(s)
- P M Dewick
- Department of Pharmaceutical Sciences, University of Nottingham, UK
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Salaün JP, Helvig C. Cytochrome P450-dependent oxidation of fatty acids. DRUG METABOLISM AND DRUG INTERACTIONS 1995; 12:261-83. [PMID: 8820856 DOI: 10.1515/dmdi.1995.12.3-4.261] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Cytochrome P450-dependent monooxygenases from plants catalyse in-chain and omega hydroxylation as well as epoxidation of medium- and long-chain fatty acids. Recent research efforts have clarified that there are multiple forms of cytochrome P450 involved in these reactions, each of which possesses distinguishable substrate specificity. The biological roles of these distinct P450 forms are poorly understood. However, evidence suggests that some may play an important role in the biosynthesis of plant cuticles. We review current knowledge on the induction and inhibition of activities as well as the regio- and stereo-specificity of the distinct forms so far characterised.
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Affiliation(s)
- J P Salaün
- Département d'Enzymologie Cellulaire et Moléculaire, Institut de Biologie Moléculaire des Plantes, CNRS-UPR 406, Strasbourg, France
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