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Introducing Selective Agrochemical Manipulation Of Gibberellin Metabolism Into A Cereal Crop, Juan Zhang, Yushi Zhang, Jiapeng Xing, Haiyue Yu, Rui Zhang, Yiyao Chen, Delin Zhang, Ping Yin, Xiaoli Tian, Qiang Wang, Liusheng Duan, Mingcai Zhang, Reuben J. Peters, Zhaohu Li Feb 2020

Introducing Selective Agrochemical Manipulation Of Gibberellin Metabolism Into A Cereal Crop, Juan Zhang, Yushi Zhang, Jiapeng Xing, Haiyue Yu, Rui Zhang, Yiyao Chen, Delin Zhang, Ping Yin, Xiaoli Tian, Qiang Wang, Liusheng Duan, Mingcai Zhang, Reuben J. Peters, Zhaohu Li

Biochemistry, Biophysics and Molecular Biology Publications

Use of growth retardants enables post-planting optimization of vegetative growth, which is particularly important with the on-going climate change. Mepiquat chloride is an economical and safe retardant widely applied in cotton, but is not uniformly effective. Here identification of its molecular target as the ent-copalyl diphosphate synthase that initiates gibberellin biosynthesis enabled introduction of selective agrochemical inhibition, leaving intact more specialized metabolism important for resistance to biotic and abiotic stresses.


Induction Of Ethylene Inhibits Development Of Soybean Sudden Death Syndrome By Inducing Defense-Related Genes And Reducing Fusarium Virguliforme Growth, Noor A. Abdelsamad, Gustavo C. Macintosh, Leonor F.S. Leandro May 2019

Induction Of Ethylene Inhibits Development Of Soybean Sudden Death Syndrome By Inducing Defense-Related Genes And Reducing Fusarium Virguliforme Growth, Noor A. Abdelsamad, Gustavo C. Macintosh, Leonor F.S. Leandro

Biochemistry, Biophysics and Molecular Biology Publications

Ethylene is a gaseous hormone that regulates plant responses to biotic and abiotic stresses. To investigate the importance of ethylene in soybean resistance to Fusarium virguliforme (Fv), the causal agent of sudden death syndrome (SDS), soybean cultivars Williams 82 (SDS-susceptible) and MN1606 (SDS-resistant) were treated 24 h before and 24h after Fv inoculation with either ethephon (ethylene inducer), cobalt chloride (ethylene biosynthesis inhibitor), or 1-MCP (ethylene perception inhibitor). Inoculated plants were grown for 21 days at 24°C in the greenhouse and then evaluated for SDS severity and expression of soybean defense genes. In both cultivars, plants treated with ethephon ...


The Genome Of The Medicinal Plant Andrographis Paniculata Provides Insight Into The Biosynthesis Of The Bioactive Diterpenoid Neoandrographolide, Wei Sun, Liang Leng, Qinggang Yin, Meimei Xu, Mingkun Huang, Zhichao Xu, Yujun Zhang, Hui Yao, Caixia Wang, Chao Xiong, Sha Chen, Chunhong Jiang, Ning Xie, Xilong Zheng, Chi Song, Reuben J. Peters, Shilin Chen Mar 2019

The Genome Of The Medicinal Plant Andrographis Paniculata Provides Insight Into The Biosynthesis Of The Bioactive Diterpenoid Neoandrographolide, Wei Sun, Liang Leng, Qinggang Yin, Meimei Xu, Mingkun Huang, Zhichao Xu, Yujun Zhang, Hui Yao, Caixia Wang, Chao Xiong, Sha Chen, Chunhong Jiang, Ning Xie, Xilong Zheng, Chi Song, Reuben J. Peters, Shilin Chen

Biochemistry, Biophysics and Molecular Biology Publications

Andrographis paniculata is a herbaceous dicot plant widely used for its anti‐inflammatory and anti‐viral properties across its distribution in China, India and other Southeast Asian countries. A. paniculata was used as a crucial therapeutic treatment during the influenza epidemic of 1919 in India, and is still used for the treatment of infectious disease in China. A. paniculata produces large quantities of the anti‐inflammatory diterpenoid lactones andrographolide and neoandrographolide, and their analogs, which are touted to be the next generation of natural anti‐inflammatory medicines for lung diseases, hepatitis, neurodegenerative disorders, autoimmune disorders and inflammatory skin diseases. Here ...


Isoprenyl Diphosphate Synthases: The Chain Length Determining Step In Terpene Biosynthesis, Raimund Nagel, Axel Schmidt, Reuben J. Peters Jan 2019

Isoprenyl Diphosphate Synthases: The Chain Length Determining Step In Terpene Biosynthesis, Raimund Nagel, Axel Schmidt, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

Main Conclusion

This review summarizes the recent developments in the study of isoprenyl diphosphate synthases with an emphasis on analytical techniques, product length determination, and the physiological consequences of manipulating expression in planta.

The highly diverse structures of all terpenes are synthesized from the five carbon precursors dimethylallyl diphosphate and a varying number of isopentenyl diphosphate units through 1’-4 alkylation reactions. These elongation reactions are catalyzed by isoprenyl diphosphate synthases (IDS). IDS are classified depending on the configuration of the ensuing double bond as trans- and cis-IDS. In addition, IDS are further stratified by the length of their ...


A Third Class: Functional Gibberellin Biosynthetic Operon In Beta-Proteobacteria, Raimund Nagel, John E. Bieber, Mark G. Schmidt-Dannert, Ryan S. Nett, Reuben J. Peters Nov 2018

A Third Class: Functional Gibberellin Biosynthetic Operon In Beta-Proteobacteria, Raimund Nagel, John E. Bieber, Mark G. Schmidt-Dannert, Ryan S. Nett, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

The ability of plant-associated microbes to produce gibberellin A (GA) phytohormones was first described for the fungal rice pathogen Gibberella fujikuroi in the 1930s. Recently the capacity to produce GAs was shown for several bacteria, including symbiotic alpha-proteobacteria (α-rhizobia) and gamma-proteobacteria phytopathogens. All necessary enzymes for GA production are encoded by a conserved operon, which appears to have undergone horizontal transfer between and within these two phylogenetic classes of bacteria. Here the operon was shown to be present and functional in a third class, the beta-proteobacteria, where it is found in several symbionts (β-rhizobia). Conservation of function was examined by ...


Direct Determination Of The Site Of Addition Of Glucosyl Units To Maltooligosaccharide Acceptors Catalyzed By Maize Starch Synthase I, Ying Xie, Adam W. Barb, Tracie A. Hennen-Bierwagen, Alan M. Myers Aug 2018

Direct Determination Of The Site Of Addition Of Glucosyl Units To Maltooligosaccharide Acceptors Catalyzed By Maize Starch Synthase I, Ying Xie, Adam W. Barb, Tracie A. Hennen-Bierwagen, Alan M. Myers

Biochemistry, Biophysics and Molecular Biology Publications

Starch synthase (SS) (ADP-glucose:1,4-α-D-glucan 4-α-D-glucosyltransferase) elongates α-(1→4)-linked linear glucans within plastids to generate the storage polymers that constitute starch granules. Multiple SS classes are conserved throughout the plant kingdom, indicating that each provides a unique function responsible for evolutionary selection. Evidence has been presented arguing for addition of glucosyl units from the ADPglucose donor to either the reducing end or the non-reducing end of the acceptor substrate, although until recently direct evidence addressing this question was not available. Characterization of newly incorporated glucosyl units determined that recombinant maize (Zea mays L.) SSIIa elongates its substrates ...


Direct Production Of Dihydroxylated Sesquiterpenoids By A Maize Terpene Synthase, Jin Liang, Jiang Liu, Reid Brown, Meirong Jia, Ke Zhou, Reuben J. Peters, Qiang Wang Jun 2018

Direct Production Of Dihydroxylated Sesquiterpenoids By A Maize Terpene Synthase, Jin Liang, Jiang Liu, Reid Brown, Meirong Jia, Ke Zhou, Reuben J. Peters, Qiang Wang

Biochemistry, Biophysics and Molecular Biology Publications

The astounding structural and biological diversity of the large class of terpenoid natural products are imparted by both their complex hydrocarbon backbones and further elaboration by the addition of multiple hydroxyl groups, which provide both solubility and specific binding properties. While the role of terpene synthases in generating hydrocarbons with complex backbones is well known, these also are known to generate (singly) hydroxylated products by the addition of water prior to terminating deprotonation. Here a maize sesquiterpene synthase was unexpectedly found to generate dually hydroxylated products directly from (E,E)-farnesyl diphosphate, primarily eudesmane-2,11-diol, along with two closely related ...


Inferring Roles In Defense From Metabolic Allocation Of Rice Diterpenoids, Xuan Lu, Juan Zhang, Benjamin Brown, Riqing Li, Julio Rodríguez-Romero, Aileen Berasategui, Bo Liu, Meimei Xu, Dangping Luo, Zhiqiang Pan, Scott R. Baerson, Jonathan Gershenzon, Zhaohu Li, Ane Sesma, Bing Yang, Reuben J. Peters May 2018

Inferring Roles In Defense From Metabolic Allocation Of Rice Diterpenoids, Xuan Lu, Juan Zhang, Benjamin Brown, Riqing Li, Julio Rodríguez-Romero, Aileen Berasategui, Bo Liu, Meimei Xu, Dangping Luo, Zhiqiang Pan, Scott R. Baerson, Jonathan Gershenzon, Zhaohu Li, Ane Sesma, Bing Yang, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

Among their responses to microbial infection, plants deploy an arsenal of natural antibiotic products. Historically these have been identified on the basis of their antibiotic activity in vitro, which leaves open the question of their relevance to defense in planta. The vast majority of such natural products from the important crop plant rice (Oryza sativa) are diterpenoids whose biosynthesis proceeds via either ent- or syn-copalyl diphosphate (CPP) intermediates, which were isolated on the basis of their antibiotic activity against the fungal blast pathogen Magnaporthe oryzae. However, rice plants in which the gene for the syn-CPP synthase Os-CPS4 is ...


Characterization Of Cyp71z18 Indicates A Role In Maize Zealexin Biosynthesis, Hongjie Mao, Jiang Liu, Fei Ren, Reuben J. Peters, Qiang Wang Jan 2016

Characterization Of Cyp71z18 Indicates A Role In Maize Zealexin Biosynthesis, Hongjie Mao, Jiang Liu, Fei Ren, Reuben J. Peters, Qiang Wang

Biochemistry, Biophysics and Molecular Biology Publications

Maize (Zea mays) produces zealexins as phytoalexins, with the inducible production of these antibiotics providing biochemical protection against fungal infection. However, the biosynthesis of these sesquiterpenoids has remained unclear. In particular, it is unclear how the olefinic precursor, (S)-β-macrocarpene produced by the characterized maize sesquiterpene synthases TPS6/11, is further elaborated to form the bioactive zealexins. The first step is likely to be conversion of carbon-15 (C15) from a methyl group to a carboxylic acid by a cytochrome P450 mono-oxygenase (CYP). In this study, CYP71Z18, whose transcription is strongly induced by fungal infection, was found to catalyze oxidation ...


Optimization Of Recombinant Expression Enables Discovery Of Novel Cytochrome P450 Activity In Rice Diterpenoid Biosynthesis, Naoki Kitaoka, Yisheng Wu, Meimei Xu, Reuben J. Peters Sep 2015

Optimization Of Recombinant Expression Enables Discovery Of Novel Cytochrome P450 Activity In Rice Diterpenoid Biosynthesis, Naoki Kitaoka, Yisheng Wu, Meimei Xu, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

The oxygenation reactions catalyzed by cytochromes P450 (CYPs) play critical roles in plant natural products biosynthesis. At the same time, CYPs are one of most challenging enzymes to functionally characterize due to the difficulty of recombinantly expressing these membrane-associated monooxygenases. In the course of investigating rice diterpenoid biosynthesis we have developed a synthetic biology approach for functional expression of relevant CYPs in Escherichia coli. In certain cases activity was observed for only one of two closely related paralogs although it seems clear that related reactions are required for production of the known diterpenoids. Here we report that optimization of the ...


Biosynthesis Of The Diterpenoid Lycosantalonol Via Nerylneryl Diphosphate In Solanum Lycopersicum, Yuki Matsuba, Jiachen Zi, A. Daniel Jones, Reuben J. Peters, Eran Pichersky Mar 2015

Biosynthesis Of The Diterpenoid Lycosantalonol Via Nerylneryl Diphosphate In Solanum Lycopersicum, Yuki Matsuba, Jiachen Zi, A. Daniel Jones, Reuben J. Peters, Eran Pichersky

Biochemistry, Biophysics and Molecular Biology Publications

We recently reported that three genes involved in the biosynthesis of monoterpenes in trichomes, a cis-prenyltransferase named neryl diphosphate synthase 1 (NDPS1) and two terpene synthases (TPS19 and TPS20), are present in close proximity to each other at the tip of chromosome 8 in the genome of the cultivated tomato (Solanum lycopersicum). This terpene gene “cluster” also contains a second cis-prenyltransferase gene (CPT2), three other TPS genes, including TPS21, and the cytochrome P450-oxidoreductase gene CYP71BN1. CPT2encodes a neryneryl diphosphate synthase. Co-expression in E. coli of CPT2 and TPS21 led to the formation of the diterpene lycosantalene, and ...


Cell Wall Traits As Potential Resources To Improve Resistance Of Durum Wheat Against Fusarium Graminearum, Vincenzo Lionetti, Angelica Giancaspro, Eleonora Fabri, Stefania L. Giove, Nathan Reem, Olga A. Zabotina, Antonio Blanco, Agata Gadaleta, Daniela Bellincampi Jan 2015

Cell Wall Traits As Potential Resources To Improve Resistance Of Durum Wheat Against Fusarium Graminearum, Vincenzo Lionetti, Angelica Giancaspro, Eleonora Fabri, Stefania L. Giove, Nathan Reem, Olga A. Zabotina, Antonio Blanco, Agata Gadaleta, Daniela Bellincampi

Biochemistry, Biophysics and Molecular Biology Publications

Background

Fusarium graminearum, one of the causal agents of Fusarium Head Blight (FHB, scab), leads to severe losses in grain yield and quality due to the production of mycotoxins which are harmful to human and livestock. Different traits for FHB resistance in wheat were identified for common wheat (Triticum aestivum L.) while the sources of FHB resistance in durum wheat (Triticum turgidum ssp. Durum), one of the cereals most susceptible to F. graminearum infection, have not been found. New lines of evidence indicate that content and composition of cell wall polymers affect the susceptibility of the wall to degrading enzymes ...


Functional Divergence Of Diterpene Syntheses In The Medicinal Plant Salvia Miltiorrhiza, Guanghong Cui, Lixin Duan, Baolong Jin, Jun Qian, Zheyong Xue, Guoan Shen, John Hugh Snyder, Jingyuan Song, Shilin Chen, Luqi Huang, Reuben J. Peters, Xiaoquan Qi Jan 2015

Functional Divergence Of Diterpene Syntheses In The Medicinal Plant Salvia Miltiorrhiza, Guanghong Cui, Lixin Duan, Baolong Jin, Jun Qian, Zheyong Xue, Guoan Shen, John Hugh Snyder, Jingyuan Song, Shilin Chen, Luqi Huang, Reuben J. Peters, Xiaoquan Qi

Biochemistry, Biophysics and Molecular Biology Publications

The medicinal plant Salvia miltiorrhiza produces various tanshinone diterpenoids that have pharmacological activities such as vasorelaxation, against ischemia-reperfusion injury, and antiarrhythmic effects. Their biosynthesis is initiated from the general diterpenoid precursor (E,E,E)-geranylgeranyl diphosphate by sequential reactions catalyzed by copalyl diphosphate synthase (CPS) and kaurene synthase-like (KSL) cyclases. Here is reported characterization of these enzymatic families from S. miltiorrhiza, which has led to the identification of novel pathways, including roles for separate CPSs in tanshinone production in roots versus aerial tissues (SmCPS1 and SmCPS2, respectively), as well as the novel production of ent-13-epi-manoyl oxide by SmCPS4 and SmKSL2 ...


To Gibberellins And Beyond! Surveying The Evolution Of (Di)Terpenoid Metabolism, Jiachen Zi, Sibongile Mafu, Reuben J. Peters Apr 2014

To Gibberellins And Beyond! Surveying The Evolution Of (Di)Terpenoid Metabolism, Jiachen Zi, Sibongile Mafu, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

The diterpenoids are classically defined by their composition, four isoprenyl units (20 carbons), and are generally derived from [E,E,E]-geranylgeranyl diphosphate (GGPP). Such metabolism seems to be ancient and has been extensively diversified, with ~12,000 diterpenoid natural products known. Particularly notable are the gibberellin phytohormones, whose requisite biosynthesis has provided a genetic reservoir giving rise to not only a large super-family of ~7,000 diterpenoids, but to some degree all plant terpenoid natural products. This review focuses on the diterpenoids, particularly the defining biosynthetic characteristics of the major superfamilies defined by the cyclization and/or rearrangement of ...


Functional Conservation Of The Capacity For Ent-Kaurene Biosynthesis And An Associated Operon In Certain Rhizobia, David M. Hershey, Xuan Lu, Jiachen Zi, Reuben J. Peters Jan 2014

Functional Conservation Of The Capacity For Ent-Kaurene Biosynthesis And An Associated Operon In Certain Rhizobia, David M. Hershey, Xuan Lu, Jiachen Zi, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

Bacterial interactions with plants are accompanied by complex signal exchange processes. Previously, the nitrogen-fixing symbiotic (rhizo)bacterium Bradyrhizobium japonicum was found to carry adjacent genes encoding two sequentially acting diterpene cyclases that together transform geranylgeranyl diphosphate to ent-kaurene, the olefin precursor to the gibberellin plant hormones. Species from the three other major genera of rhizobia were found to have homologous terpene synthase genes. Cloning and functional characterization of a representative set of these enzymes confirmed the capacity of each genus to produce ent-kaurene. Moreover, comparison of their genomic context revealed that these diterpene synthases are found in a conserved operon ...


Functional Characterization Of Wheat Ent-Kaurene(-Like) Synthases Indicates Continuing Evolution Of Labdane-Related Diterpenoid Metabolism In The Cereals, Ke Zhou, Meimei Xu, Mollie Tiernan, Qian Xie, Tomonobu Toyomasu, Chizu Sugawara, Madoka Oku, Masami Usui, Wataru Mitsuhashi, Makiko Chono, Peter M. Chandler, Reuben J. Peters Dec 2012

Functional Characterization Of Wheat Ent-Kaurene(-Like) Synthases Indicates Continuing Evolution Of Labdane-Related Diterpenoid Metabolism In The Cereals, Ke Zhou, Meimei Xu, Mollie Tiernan, Qian Xie, Tomonobu Toyomasu, Chizu Sugawara, Madoka Oku, Masami Usui, Wataru Mitsuhashi, Makiko Chono, Peter M. Chandler, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

Wheat (Triticum aestivum) and rice (Oryza sativa) are two of the most agriculturally important cereal crop plants. Rice is known to produce numerous diterpenoid natural products that serve as phytoalexins and/or allelochemicals. Specifically, these are labdane-related diterpenoids, derived from a characteristic labdadienyl/copalyl diphosphate (CPP), whose biosynthetic relationship to gibberellin biosynthesis is evident from the relevant expanded and functionally diverse family of ent-kaurene synthase-like (KSL) genes found in rice the (OsKSLs). Herein reported is the biochemical characterization of a similarly expansive family of KSL from wheat (the TaKSLs). In particular, beyond ent-kaurene synthases (KS), wheat also contains ...


Cyp701a8: A Rice Ent-Kaurene Oxidase Paralog Diverted To More Specialized Diterpenoid Metabolism, Qiang Wang, Matthew L. Hillwig, Yisheng Wu, Reuben J. Peters Mar 2012

Cyp701a8: A Rice Ent-Kaurene Oxidase Paralog Diverted To More Specialized Diterpenoid Metabolism, Qiang Wang, Matthew L. Hillwig, Yisheng Wu, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

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 ...


Deficiency Of Maize Starch-Branching Enzyme I Results In Altered Starch Fine Structure, Decreased Digestibility And Reduced Coleoptile Growth During Germination, Huan Xia, Marna Yandeau-Nelson, Donald B. Thompson, Mark J. Guiltinan May 2011

Deficiency Of Maize Starch-Branching Enzyme I Results In Altered Starch Fine Structure, Decreased Digestibility And Reduced Coleoptile Growth During Germination, Huan Xia, Marna Yandeau-Nelson, Donald B. Thompson, Mark J. Guiltinan

Biochemistry, Biophysics and Molecular Biology Publications

Background: Two distinct starch branching enzyme (SBE) isoforms predate the divergence of monocots and dicots and have been conserved in plants since then. This strongly suggests that both SBEI and SBEII provide unique selective advantages to plants. However, no phenotype for the SBEI mutation, sbe1a, had been previously observed. To explore this incongruity the objective of the present work was to characterize functional and molecular phenotypes of both sbe1a and wild-type (Wt) in the W64A maize inbred line.

Results: Endosperm starch granules from the sbe1a mutant were more resistant to digestion by pancreatic aamylase, and the sbe1a mutant starch had ...


Synergistic Substrate Inhibition Of Ent-Copalyl Diphosphate Synthase: A Potential Feed-Forward Inhibition Mechanism Limiting Gibberellin Metabolism, Sladjana Prisic, Reuben J. Peters May 2007

Synergistic Substrate Inhibition Of Ent-Copalyl Diphosphate Synthase: A Potential Feed-Forward Inhibition Mechanism Limiting Gibberellin Metabolism, Sladjana Prisic, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

Gibberellins (GAs) or gibberellic acids are ubiquitous diterpenoid phytohormones required for many aspects of plant growth and development, including repression of photosynthetic pigment production (i.e. deetiolation) in the absence of light. The committed step in GA biosynthesis is catalyzed in plastids by ent-copalyl diphosphate synthase (CPS), whose substrate, (E,E,E,)-geranylgeranyl diphosphate (GGPP), is also a direct precursor of carotenoids and the phytol side chain of chlorophyll. Accordingly, during deetiolation, GA production is repressed, whereas flux toward these photosynthetic pigments through their common GGPP precursor is dramatically increased. How this is accomplished has been unclear because no ...


Rice Contains Two Disparate Ent-Copalyl Diphosphate Synthases With Distinct Metabolic Functions, Sladjana Prisic, Meimei Xu, P. Ross Wilderman, Reuben J. Peters Dec 2004

Rice Contains Two Disparate Ent-Copalyl Diphosphate Synthases With Distinct Metabolic Functions, Sladjana Prisic, Meimei Xu, P. Ross Wilderman, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

Rice (Oryza sativa) produces ent-copalyl diphosphate for both gibberellin (GA) phytohormone and defensive phytoalexin biosynthesis, raising the question of how this initial biosynthetic step is carried out for these distinct metabolic processes. Here, a functional genomics approach has been utilized to identify two disparate ent-copalyl diphosphate synthases from rice (OsCPS1ent and OsCPS2ent). Notably, it was very recently demonstrated that only one of these (OsCPS1ent) normally operates in GA biosynthesis as mutations in this gene result in severely impaired growth. Evidence is presented here strongly indicating that the other (OsCPS2ent) is involved in related secondary ...


Identification Of Syn-Pimara-7,15-Diene Synthase Reveals Functional Clustering Of Terpene Synthases Involved In Rice Phytoalexin/Allelochemical Biosynthesis, P. Ross Wilderman, Meimei Xu, Yinghua Jin, Robert M. Coates, Reuben J. Peters Aug 2004

Identification Of Syn-Pimara-7,15-Diene Synthase Reveals Functional Clustering Of Terpene Synthases Involved In Rice Phytoalexin/Allelochemical Biosynthesis, P. Ross Wilderman, Meimei Xu, Yinghua Jin, Robert M. Coates, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

Rice (Oryza sativa) produces momilactone diterpenoids as both phytoalexins and allelochemicals. Accordingly, the committed step in biosynthesis of these natural products is catalyzed by the class I terpene synthase that converts syn-copalyl diphosphate to the corresponding polycyclic hydrocarbon intermediate syn-pimara-7,15-diene. Here, a functional genomics approach was utilized to identify a syn-copalyl diphosphate specific 9β-pimara-7,15-diene synthase (OsDTS2). To our knowledge, this is the first identified terpene synthase with this particular substrate stereoselectivity and, by comparison with the previously described and closely related ent-copalyl diphosphate specific cassa-12,15-diene synthase (OsDTC1), provides a model system ...