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Cell-free extracts of UV-irradiated rice (Oryza sativa L.) leaves have a much greater capacity for the synthesis from geranylgeranyl pyrophosphate of diterpene hydrocarbons, including the putative precursors of rice phytoalexins, than extracts of unstressed leaves (KA Wickham, CA West [1992] Arch
Two new pimarane diterpenoids, momilactone D (3) and momilactone E (5), along with three known diterpenoids, momilactone A (1), sandaracopimaradien-3-one (2), and oryzalexin A (4) were isolated from Oryza sativa roots. The chemical structures of the compounds were determined by spectroscopic data
Rice (Oryza sativa L.) produces a variety of diterpene phytoalexins, such as momilactones, phytocassanes, and oryzalexins. Momilactone B was previously identified as an allelopathic substance exuded from the roots of rice. We identified in this present study momilactone A and phytocassanes A-E in
Rice (Oryza sativa L.) produces diterpene phytoalexins, such as momilactones, oryzalexins, and phytocassanes. Using rice genome information and in vitro assay with recombinant enzymes, we identified genes (OsKS4 and OsKS10) encoding the type-A diterpene cyclases 9beta-pimara-7,15-diene synthase and
Cultivated rice (Oryza sativa; Os) produces a variety of labdane-related diterpenoids; not only phytohormone gibberellins (GAs) but also phytoalexins for defense including phytocassanes, momilactones and oryzalexins. Their carbon skeleton diterpenes are constructed from geranylgeranyl diphosphate
Gibberellins (GAs) are labdane-related diterpenoid phytohormones that regulate various aspects of higher plant growth. A biosynthetic intermediate of GAs is ent-kaurene, a tetra-cyclic diterpene that is produced through successive cyclization of geranylgeranyl diphosphate catalyzed by the two
Diterpenoids constitute a diverse class of metabolites with critical functions in plant development, defense, and ecological adaptation. Major monocot crops, such as maize (Zea mays) and rice (Oryza sativa), deploy diverse blends of specialized diterpenoids as core components of biotic and abiotic
• There is controversy as to whether specific natural products play a role in directly mediating antagonistic plant-plant interactions - that is, allelopathy. If proved to exist, such phenomena would hold considerable promise for agronomic improvement of staple food crops such as rice (Oryza
Ent-isopimara-8(14),15-dien-3 beta-ol (1) was isolated from uv-irradiated rice (Oryza sativa L.) leaves. Since 1 was converted to the rice diterpene phytoalexins and oryzalexins D (ent-isopimara-8(14),15-diene-3 beta,7 alpha-diol) and E (ent-isopimara-8(14),15-diene-3 beta,9 alpha-diol) in
We have previously isolated and characterized the rice (Oryza sativa) cDNAs, OsCyc1/OsCPS4, OsCyc2/OsCPS2, OsKS4, OsDTC1/OsKS7, OsDTC2/OsKS8 and OsKS10, which encode cyclases that are responsible for diterpene phytoalexin biosynthesis. Among the other members of this gene family, OsCPS1 and OsKS1
The evolution of natural product biosynthetic pathways can be envisioned to occur via a number of mechanisms. In the present study we provide evidence that latent plasticity plays a role in such metabolic evolution. In particular, rice (Oryza sativa) produces both ent- and syn-CPP (copalyl
The formation of body axes is the basis of morphogenesis during plant embryogenesis. We identified embryo-lethal mutants of rice (Oryza sativa) in which T-DNAs were inserted in OsMPK6 Embryonic organs were absent because their development was arrested at the globular stage. Similar to observations
Rice (Oryza sativa) produces momilactone diterpenoids as both phytoalexins and allelochemicals. Strikingly, the rice genome contains a biosynthetic gene cluster for momilactone production, located on rice chromosome 4, which contains two cytochrome P450 (CYP) mono-oxygenases, CYP99A2 and CYP99A3,
Durable resistance to blast, the most significant fungal disease of rice, represents an agronomically relevant character. Gigante Vercelli (GV) and Vialone Nano (VN) are two old temperate japonica Italian rice cultivars with contrasting response to blast infection: GV displays durable and broad
Cultivated rice (Oryza sativa) possesses various labdane-related diterpene synthase genes, homologs of ent-copalyl diphosphate synthase (CPS) and ent-kaurene synthase (KS) that are responsible for the biosynthesis of phytohormone gibberellins. The CPS homologs and KS like (KSL) homologs successively