Biosynthesis of Cyclic Diterpene Hydrocarbons in Rice Cell Suspensions: Conversion of 9,10-syn-Labda-8(17),13-dienyl Diphosphate to 9β-Pimara-7,15-diene and Stemar-13-ene

Mohan, Ram S.; Yee, Nathan K.; Coates, Robert M.; Ren, Yaoyao; Stamenković, Predrag; Mendez, Irena; West, Charles A.

doi:10.1006/abbi.1996.0223

Cited by 47 publications

(25 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Early work with cell‐free extracts demonstrated the production of numerous expected diterpene olefins (Wickham and West, ). KS(L) enzymes act on either stereochemically differentiated syn ‐CDP as the intermediate in formation of momilactones and oryzalexin S, or the ent ‐CDP stereoisomer, which is required for biosynthesis of GAs, oryzalexins A–F, phytocassanes and oryzalide‐related diterpenoids (Figure ) (Mohan et al ., ; Peters, ; Toyomasu, ).…”

Section: Discovery and Biosynthesis Of Rice Diterpenoid Phytoalexinsmentioning

confidence: 99%

Biosynthesis, elicitation and roles of monocot terpenoid phytoalexins

et al. 2014

View full text Add to dashboard Cite

SUMMARYA 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 b-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.

show abstract

Section: Discovery and Biosynthesis Of Rice Diterpenoid Phytoalexinsmentioning

confidence: 99%

Biosynthesis, elicitation and roles of monocot terpenoid phytoalexins

et al. 2014

View full text Add to dashboard Cite

show abstract

“…In particular, because rice was known to make a number of labdane-related diterpenoid natural products, the corresponding multiple diterpene synthase activities had been demonstrated, 38 and the agronomic importance of this staple cereal crop plant had led to early sequencing of its genome. 39–41 This led to parallel investigations by our own group and a consortium in Japan.…”

Section: A Single Residue Switch For Diterpene Synthase Product Outcomementioning

confidence: 99%

Electrostatic effects on (di)terpene synthase product outcome

Zhou

Peters

2011

Chem. Commun.

View full text Add to dashboard Cite

Terpene synthases catalyze complex reactions, often forming multiple chiral centers in cyclized olefin products from acyclic allylic diphosphate precursors, yet have been suggested to exert little control over the actual reaction, instead largely serving as inert templates. However, recent results highlight stereoelectronic effects exerted by these enzymes. Perhaps not surprisingly, the pyrophosphate co-product released in the initiating and rate-limiting chemical step provides an obvious counter-ion that may drive carbocation migration towards itself. This is emphasized by the striking effects of a recently uncovered single residue switch for diterpene synthase product outcome, whereby substitution of hydroxyl residues for particular aliphatic residues has been shown to be sufficient to “short-circuit” complex cyclization and/or rearrangement reactions, with the converse change further found to be sufficient to increase reaction complexity. The mechanistic hypothesis for the observed effects is hydroxyl dipole stabilization of the specific carbocation formed by initial cyclization, enabling deprotonation of this early intermediate, whereas the lack of such stabilization (i.e. with an aliphatic side chain) leads to carbocation migration towards the pyrophosphate co-product, resulting in a more complex reaction. This is further consistent with the greater synergy exhibited between pyrophosphate and aza-analogs of late, relative to early, stage carbocation intermediates, and crystallographic analysis of the monoterpene cyclase bornyl diphosphate synthase wherein mechanistically non-relevant counter-ion pairing between aza-analogs of early stage carbocation intermediates and pyrophosphate is observed. Thus, (di)terpene synthases seem to mediate specific reaction outcomes, at least in part, by providing stereoelectronic effects to counteract those exerted by the pyrophosphate co-product.

show abstract

“…However, since rice produces only ent - and syn -CPP, as first suggested by substrate studies with cell-free enzyme assays [7, 8], and then more conclusively demonstrated by functional genomics based investigations of the rice CPS family [9-11], the rice KSL (OsKSL) were only assayed with these two stereoisomers [12-18]. This OsKSL family, with eight functional members (Scheme 2), provided an opportunity to comprehensively explore diterpene synthase substrate stereospecificity not only for individual enzymes, but also across an entire organism/genome, providing insight into the encoded metabolic plasticity.…”

Section: Introductionmentioning

confidence: 99%

Evident and latent plasticity across the rice diterpene synthase family with potential implications for the evolution of diterpenoid metabolism in the cereals

Morrone

Hillwig

Mead

et al. 2011

Biochemical Journal

View full text Add to dashboard Cite

SYNOPSIS The evolution of natural products biosynthetic pathways can be envisioned to occur via a number of mechanisms. Here we provide evidence that latent plasticity plays a role in such metabolic evolution. In particular, rice (Oryza sativa) produces both ent- and syn-copalyl diphosphate (CPP), which are substrates for downstream diterpene synthases. Here we report that several members of this enzymatic family exhibit dual reactivity with some pairing of ent-, syn-, or normal CPP stereochemistry. Evident plasticity was observed, as a previously reported ent-sandaracopimaradiene synthase also converts syn-CPP to syn-labda-8(17),12E,14-triene, which can be found in planta. Notably, normal CPP is not naturally found in rice. Thus, the presence of diterpene synthases that react with this non-native metabolite reveals latent enzymatic/metabolic plasticity, providing biochemical capacity for utilization of such a novel substrate (i.e., normal CPP) that may arise during evolution, the implications of which are discussed.

show abstract

Biosynthesis of Cyclic Diterpene Hydrocarbons in Rice Cell Suspensions: Conversion of 9,10-syn-Labda-8(17),13-dienyl Diphosphate to 9β-Pimara-7,15-diene and Stemar-13-ene

Cited by 47 publications

References 0 publications

Biosynthesis, elicitation and roles of monocot terpenoid phytoalexins

Biosynthesis, elicitation and roles of monocot terpenoid phytoalexins

Electrostatic effects on (di)terpene synthase product outcome

Evident and latent plasticity across the rice diterpene synthase family with potential implications for the evolution of diterpenoid metabolism in the cereals

Contact Info

Product

Resources

About