| antigenic cross-reactivity among monoterpene cyclases from grand fir and induction of these enzymes upon stem wounding. | a major wound response in grand fir (abies grandis) sapling stems is the rapid increase in monoterpene production at the site of injury. monoterpene cyclases (synthases) catalyze the formation of monoterpenes from geranyl pyrophosphate, and total cyclase activity increases markedly on wounding. at least six distinct cyclases, producing different monoterpene products, have been isolated from wounded grand fir saplings and characterized. the predominant wound-inducible cyclase produces both alpha- ... | 1992 | 1567222 |
| contemporary use of bark for medicine by two salishan native elders of southeast vancouver island, canada. | elders of the saanich and cowichan coast salish people of southern vancouver island treat, or have treated in the recent past, many ailments with bark preparations. interviews with two elder salishan women revealed that: respiratory ailments were treated with bark of abies grandis, arbutus menziesii, cornus nuttallii, prunus emarginata, pseudotsuga menziesii and quercus garryana; digestive tract ailments with the bark of abies grandis, alnus rubra, arbutus menziesii, malus fusca. oemleria cerasi ... | 1990 | 2345461 |
| diterpenoid resin acid biosynthesis in conifers: enzymatic cyclization of geranylgeranyl pyrophosphate to abietadiene, the precursor of abietic acid. | abietic acid is a major component of the rosin fraction of oleoresin synthesized by conifer species, such as grand fir (abies grandis) and lodgepole pine (pinus contorta), as a defensive secretion against insect and pathogen attack. this diterpenoid resin acid is derived from geranylgeranyl pyrophosphate by conversion to abietadiene and sequential oxidation of the c18-methyl group of the precursor olefin to a carboxyl function. resin acid biosynthesis is constitutively expressed at high levels i ... | 1994 | 8053674 |
| monoterpene synthases of pinus contorta and related conifers. a new class of terpenoid cyclase. | a cell-free extract from the xylem of lodgepole pine (pinus contorta) catalyzes the conversion of [1-3h1]geranyl pyrophosphate to a variety of monoterpene olefins found in lodgepole pine oleoresin. this monoterpene synthase activity is similar to previously described terpenoid cyclases from grand fir (abies grandis) and other higher plants in molecular mass (67 +/- 2 kda as estimated by size-exclusion chromatography), km for geranyl pyrophosphate (7.8 +/- 1.9 microm), and isoelectric point (4.75 ... | 1994 | 8307957 |
| diterpenoid resin acid biosynthesis in conifers: characterization of two cytochrome p450-dependent monooxygenases and an aldehyde dehydrogenase involved in abietic acid biosynthesis. | abietic acid is a major component of the rosin fraction of oleoresin synthesized by grand fir (abies grandis), lodgepole pine (pinus contorta), and many other conifer species as a defensive secretion against insect and pathogen attack. the diterpenoid resin acid is derived from geranylgeranyl pyrophosphate via abietadiene, with subsequent oxidation of the c18-methyl of this olefin to abietadienol, abietadienal, and abietic acid. the pathway was confirmed by administering [1,2-14c]acetic acid to ... | 1994 | 8311462 |
| abietadiene synthase from grand fir (abies grandis). cdna isolation, characterization, and bacterial expression of a bifunctional diterpene cyclase involved in resin acid biosynthesis. | (-)-abietic acid, the principal diterpenoid resin acid of the wound-induced oleoresin secreted by grand fir (abies grandis), is synthesized by the cyclization of geranylgeranyl diphosphate to (-)-abieta-7(8),13(14)-diene, followed by sequential three-step oxidation of the c-18 methyl group of the olefin to a carboxyl function. the enzyme catalyzing the cyclization reaction, abietadiene synthase, was purified from stems of wounded grand fir saplings and was digested with trypsin. amino acid seque ... | 1996 | 8798524 |
| monoterpene synthases from grand fir (abies grandis). cdna isolation, characterization, and functional expression of myrcene synthase, (-)-(4s)-limonene synthase, and (-)-(1s,5s)-pinene synthase. | grand fir (abies grandis) has been developed as a model system for studying defensive oleoresin formation in conifers in response to insect attack or other injury. the turpentine fraction of the oleoresin is a complex mixture of monoterpene (c10) olefins in which (-)-limonene and (-)-alpha- and (-)-beta-pinene are prominent components; (-)-limonene and (-)-pinene synthase activities are also induced upon stem wounding. a similarity based cloning strategy yielded three new cdna species from a wou ... | 1997 | 9268308 |
| sesquiterpene synthases from grand fir (abies grandis). comparison of constitutive and wound-induced activities, and cdna isolation, characterization, and bacterial expression of delta-selinene synthase and gamma-humulene synthase. | grand fir (abies grandis) has been developed as a model system for the study of oleoresin production in response to stem wounding and insect attack. the turpentine fraction of the oleoresin was shown to contain at least 38 sesquiterpenes that represent 12.5% of the turpentine, with the monoterpenes comprising the remainder. assays of cell-free extracts from grand fir stem with farnesyl diphosphate as substrate indicated that the constitutive sesquiterpene synthases produced the same sesquiterpen ... | 1998 | 9442047 |
| terpenoid-based defenses in conifers: cdna cloning, characterization, and functional expression of wound-inducible (e)-alpha-bisabolene synthase from grand fir (abies grandis). | (e)-alpha-bisabolene synthase is one of two wound-inducible sesquiterpene synthases of grand fir (abies grandis), and the olefin product of this cyclization reaction is considered to be the precursor in abies species of todomatuic acid, juvabione, and related insect juvenile hormone mimics. a cdna encoding (e)-alpha-bisabolene synthase was isolated from a wound-induced grand fir stem library by a pcr-based strategy and was functionally expressed in escherichia coli and shown to produce (e)-alpha ... | 1998 | 9618485 |
| cdna cloning, characterization, and functional expression of four new monoterpene synthase members of the tpsd gene family from grand fir (abies grandis). | grand fir (abies grandis) is a useful model system for studying the biochemistry, molecular genetics, and regulation of defensive oleoresin formation in conifers, a process involving both the constitutive accumulation of resin (pitch) in specialized secretory structures and the induced biosynthesis of monoterpenes and sesquiterpenes (turpentine) and diterpene resin acids (rosin) by nonspecialized cells at the site of injury. a similarity-based cloning strategy, employing primers designed to cons ... | 1999 | 10441373 |
| diversity and variability of terpenoid defences in conifers: molecular genetics, biochemistry and evolution of the terpene synthase gene family in grand fir (abies grandis). | this review focuses on the molecular genetics, biochemistry and evolution of terpenoid synthases relevant to terpenoid defences in conifers. in grand fir (abies grandis) biosynthesis of terpenoids of the three classes of monoterpenes, sesquiterpenes and diterpenes is inducible by stem wounding at the level of gene activation and increase of enzyme activity of the respective terpene synthases. the monoterpene, sesquiterpene and diterpene synthases utilize prenyl diphosphates of appropriate size a ... | 1999 | 10549552 |
| abietadiene synthase from grand fir (abies grandis): characterization and mechanism of action of the "pseudomature" recombinant enzyme. | the oleoresin secreted by grand fir (abies grandis) is composed of resin acids derived largely from the abietane family of diterpene olefins as precursors which undergo subsequent oxidation of the c18-methyl group to a carboxyl function, for example, in the conversion of abieta-7,13-diene to abietic acid. a cdna encoding abietadiene synthase has been isolated from grand fir and the heterologously expressed bifunctional enzyme shown to catalyze both the protonation-initiated cyclization of gerany ... | 2000 | 11112547 |
| carbon stocks and soil respiration rates during deforestation, grassland use and subsequent norway spruce afforestation in the southern alps, italy. | changes in carbon stocks during deforestation, reforestation and afforestation play an important role in the global carbon cycle. cultivation of forest lands leads to substantial losses in both biomass and soil carbon, whereas forest regrowth is considered to be a significant carbon sink. we examined below- and aboveground carbon stocks along a chronosequence of norway spruce (picea abies (l.) karst.) stands (0-62 years old) regenerating on abandoned meadows in the southern alps. a 130-year-old ... | 2000 | 11303575 |
| sugar recovery and fermentability of hemicellulose hydrolysates from steam-exploded softwoods containing bark. | the hemicellulose sugar recovery and ethanol production obtained from so2-catalyzed steam explosion of a mixed white fir (70%) and ponderosa pine (30%) feedstock containing bark (9% dry weight/dry weight) was assessed. more than 90% of the available hemicellulose sugars could be recovered in the hydrolysate obtained after steam explosion at 195 degrees c, 2.38 min, and 3.91% so2, with 59% of the original hemicellulose sugars detected in a monomeric form. despite this high sugar recovery, this hy ... | 2001 | 11587580 |
| interaction with the small subunit of geranyl diphosphate synthase modifies the chain length specificity of geranylgeranyl diphosphate synthase to produce geranyl diphosphate. | geranyl diphosphate synthase belongs to a subgroup of prenyltransferases, including farnesyl diphosphate synthase and geranylgeranyl diphosphate synthase, that catalyzes the specific formation, from c(5) units, of the respective c(10), c(15), and c(20) precursors of monoterpenes, sesquiterpenes, and diterpenes. unlike farnesyl diphosphate synthase and geranylgeranyl diphosphate synthase, which are homodimers, geranyl diphosphate synthase from mentha is a heterotetramer in which the large subunit ... | 2002 | 11733504 |
| geranyl diphosphate synthase from abies grandis: cdna isolation, functional expression, and characterization. | geranyl diphosphate synthase catalyzes the condensation of dimethylallyl diphosphate and isopentenyl diphosphate to generate geranyl diphosphate, the essential precursor of monoterpene biosynthesis. using geranylgeranyl diphosphate synthase from taxus canadensis as a hybridization probe, four full length cdna clones, sharing high sequence identity to each other (>69%) and to the taxus geranylgeranyl diphosphate synthase (>66%), were isolated from a grand fir (abies grandis) cdna library. when ex ... | 2002 | 12176066 |
| decreased needle longevity of fertilized douglas-fir and grand fir in the northern rockies. | changes in nutrient availability significantly affect canopy dynamics in conifers. to elucidate these effects, we experimentally fertilized mixed conifer stands at several sites across the northern rocky mountains. we measured needle longevity, total branch length and foliated length along the main branch axis, and determined mean retained cohort length on mid-canopy branches of shade-intolerant douglas-fir (pseudotsuga menziesii var. glauca (beissn.) franco) and shade-tolerant grand fir (abies ... | 2000 | 12651495 |
| sources of variation in ecophysiological parameters in douglas-fir and grand fir canopies. | forest process models predict ecosystem responses from climate variables and physiological parameters. the parameters describe key ecosystem attributes, often as lumped averages. however, the sources and magnitude of variation in these physiological parameters are unknown, which complicates sampling if models are to be parameterized with field measurements. we measured several key parameters, which had been identified by sensitivity analyses of three models, in abies grandis (dougl.) lindl. and ... | 2003 | 12750052 |
| xylem cavitation in roots and stems of douglas-fir and white fir. | roots of hardwoods have been shown to be more vulnerable to xylem cavitation than stems. this study examined whether this pattern is also observed in a conifer species. vulnerability to cavitation was determined from the pressure required to inject air into the vascular system of hydrated roots and stems, and reduce hydraulic conductance of the xylem. according to the air-seeding hypothesis for the cavitation mechanism, these air pressures predict the negative xylem pressure causing cavitation i ... | 1997 | 14759867 |
| effects of acidic fog on seedlings of pinus ponderosa and abies concolor: foliar injury, physiological and biochemical responses. | seedlings of pinus ponderosa (ponderosa pine) and abies concolor (white fir) were exposed to acidic fog (ph 2.0, 3.0 or 4.0) in open-field plots for six weeks. the two species exhibited dissimilar injury responses; neither current year nor previous year needles of ponderosa pine were injured by ph 2.0 fog, but current year needles exhibited higher membrane permeability responses (i.e. needle extract conductivity, k+ concentration). in comparison, both needle age classes in white fir were signifi ... | 1993 | 15091884 |
| diterpene resin acid biosynthesis in loblolly pine (pinus taeda): functional characterization of abietadiene/levopimaradiene synthase (pttps-las) cdna and subcellular targeting of pttps-las and abietadienol/abietadienal oxidase (ptao, cyp720b1). | diterpene resin acids are prominent defense compounds against insect pests and pathogens in conifers. biochemical and molecular analyses in grand fir (abies grandis), norway spruce (picea abies), and loblolly pine (pinus taeda) have identified two classes of genes and enzymes that generate much of the structural diversity of terpenoid defense compounds: the terpenoid synthases (tps) and cytochrome p450 monooxgenases (p450). using a single substrate, geranylgeranyl diphosphate, families of single ... | 2006 | 16497345 |
| defense mechanisms of conifers : differences in constitutive and wound-induced monoterpene biosynthesis among species. | levels of monoterpene cyclase activity were determined in extracts from wounded and unwounded saplings of 10 conifer species to assess whether oleoresin biosynthesis is induced by stem wounding. species of abies and picea, with low to moderate levels of constitutive monoterpene cyclase activity, exhibited a five- to 15-fold increase in cyclase activity 7 days after wounding relative to unwounded controls. in contrast, species of genera such as pinus, with high levels of constitutive cyclase acti ... | 1991 | 16668184 |
| demography of northern flying squirrels informs ecosystem management of western interior forests. | we studied northern flying squirrel (glaucomys sabrinus) demography in the eastern washington cascade range to test hypotheses about regional and local abundance patterns and to inform managers of the possible effects of fire and fuels management on flying squirrels. we quantified habitat characteristics and squirrel density, population trends, and demography in three typical forest cover types over a four-year period. we had 2034 captures of flying squirrels over 41 000 trap nights from 1997 th ... | 2006 | 16711046 |
| gene expression profiles of different breast cancer cells compared with their responsiveness to fermented mistletoe (viscum album l.) extracts iscador from oak (quercus), pine (pinus), white fir (abies) and apple tree (malus) in vitro. | cytotoxicity assays in vitro (mtt test) showed that the different breast cancer cell lines kpl-1, mcf-7 and mfm-223 respond differently to the mistletoe (viscum album l.) preparations iscador. quercus (qu), abies (a), malus (m) and pinus (p). in order to determine the differences in the responsiveness of the cells more exactly, the gene expression profiles were determined by cells, which were treated with mistletoe extracts, compared with untreated control cells. such differences can be analysed ... | 2006 | 16927530 |
| mistletoe lectin is not the only cytotoxic component in fermented preparations of viscum album from white fir (abies pectinata). | preparations of mistletoe (viscum album) are the form of cancer treatment that is most frequently used in the complementary medicine. previous work has shown that these preparations are able to exert cytotoxic effects on carcinoma cells, the extent of which might be influenced by the host tree species and by the content of mistletoe lectin. | 2007 | 17493268 |
| late pleistocene history of coniferous woodland in the mohave desert. | seventeen ancient wood-rat middens, ranging in radiocarbon age from 7400 to 19,500 years and to older than 40,000 years, have been uncovered in the northeastern, north-central, southeastern, and southwestern sectors of the mohave desert. excellent preservation of macroscopic plant materials (including stems, buds, leaves, fruits, and seeds) enables identification of many plant species growing within the limited foraging range of the sedentary wood rat. an approximately synchronous zonal differen ... | 1967 | 17759528 |
| suitability of pines and other conifers as hosts for the invasive mediterranean pine engraver (coleoptera: scolytidae) in north america. | the invasive mediterranean pine engraver, orthotomicus erosus (wollaston) (coleoptera: scolytidae), was detected in north america in 2004, and it is currently distributed in the southern central valley of california. it originates from the mediterranean region, the middle east, and asia, and it reproduces on pines (pinus spp.). to identify potentially vulnerable native and adventive hosts in north america, no-choice host range tests were conducted in the laboratory on 22 conifer species. the bee ... | 2008 | 18613584 |
| dwarf mistletoe-host interactions in mixed-conifer forests in the sierra nevada. | abstract we determined the spatial pattern of dwarf mistletoe (arceuthobium spp.) associated with two different conifer hosts, white fir (abies concolor) and jeffrey pine (pinus jeffreyi), in forests around the lake tahoe basin and at the teakettle experimental forest, both located in the sierra nevada. we also examined a number of host variables and bark beetle incidence to determine how these factors might be involved in the arceuthobium-conifer interaction. there was no significant relationsh ... | 2002 | 18944255 |
| defining how aging pseudotsuga and abies compensate for multiple stresses through multi-criteria assessment of a functional-structural model. | many hypotheses have been advanced about factors that control tree longevity. we use a simulation model with multi-criteria optimization and pareto optimality to determine branch morphologies in the pinaceae that minimize the effect of growth limitations due to water stress while simultaneously maximizing carbohydrate gain. two distinct branch morphologies in the pareto optimal space resemble pseudotsuga menziesii (mirb.) franco and abies grandis (dougl. ex d. don) lindl., respectively. these mo ... | 2010 | 19945994 |
| plasticity in physiological traits in conifers: implications for response to climate change in the western u.s. | population variation in ecophysiological traits of four co-occurring montane conifers was measured on a large latitudinal gradient to quantitatively assess their potential for response to environmental change. white fir (abies concolor) had the highest variability, gross photosynthetic rate (pg), and foliar carbon (c) and nitrogen (n) content. despite low water use efficiency (wue), stomatal conductance (gs) of fir was the most responsive to unfavorable environmental conditions. pinus lambertian ... | 2010 | 20056301 |
| vertical and seasonal variation in the {delta}13c of leaf-respired co2 in a mixed conifer forest. | the c-isotopic composition (δ(13)c) of leaf respiration (δ(lr)) has previously been shown to vary among functional groups, plant organs and times of day. we here investigated vertical and seasonal variation in δ(lr) through deep (∼35 m) forest canopies. we measured δ(lr), δ(13)c of leaf bulk organic matter (δ(lb)), specific leaf area, net photosynthesis (a) and dark respiration in shade, middle and sun foliage in four conifer species from may to august. we used keeling plots to estimate δ(lr); w ... | 2011 | 21551356 |
| the effects of α-cellulose extraction and blue-stain fungus on retrospective studies of carbon and oxygen isotope variation in live and dead trees. | tree-ring carbon and oxygen isotope ratios from live and recently dead trees may reveal important mechanisms of tree mortality. however, wood decay in dead trees may alter the δ(13)c and δ(18)o values of whole wood obscuring the isotopic signal associated with factors leading up to and including physiological death. we examined whole sapwood and α-cellulose from live and dead specimens of ponderosa pine (pinus ponderosa), one-seed juniper (juniperous monosperma), piñon pine (pinus edulis) and wh ... | 2011 | 21953963 |
| biosynthesis of β-carotene in engineered e. coli using the mep and mva pathways. | β-carotene is a carotenoid compound that has been widely used not only in the industrial production of pharmaceuticals but also as nutraceuticals, animal feed additives, functional cosmetics, and food colorants. currently, more than 90% of commercial β-carotene is produced by chemical synthesis. due to the growing public concern over food safety, the use of chemically synthesized β-carotene as food additives or functional cosmetic agents has been severely controlled in recent years. this has rei ... | 2014 | 25403509 |
| engineering escherichia coli for high-yield geraniol production with biotransformation of geranyl acetate to geraniol under fed-batch culture. | geraniol is an acyclic monoterpene alcohol, which exhibits good prospect as a gasoline alternative. geraniol is naturally encountered in plants at low concentrations and an attractive target for microbial engineering. geraniol has been heterologously produced in escherichia coli, but the low titer hinders its industrial applications. moreover, bioconversion of geraniol by e. coli remains largely unknown. | 2016 | 26973712 |
| utilization of alkaline phosphatase phoa in the bioproduction of geraniol by metabolically engineered escherichia coli. | geraniol is a valuable acyclic monoterpene alcohol and has many applications in the perfume industries, pharmacy and others. it has been hypothesized that phosphatases can convert geranyl diphosphate (gpp) into geraniol. however, whether and which phosphatases can transform gpp to geraniol has remained unanswered up till now. in this paper, the catalysis abilities of 4 different types of phosphatases were studied with gpp as substrate in vitro. they are bifunctional diacylglycerol diphosphate ph ... | 2015 | 26091008 |
| microbial synthesis of pinene. | the volumetric heating values of today's biofuels are too low to power energy-intensive aircraft, rockets, and missiles. recently, pinene dimers were shown to have a volumetric heating value similar to that of the tactical fuel jp-10. to provide a sustainable source of pinene, we engineered escherichia coli for pinene production. we combinatorially expressed three pinene synthases (ps) and three geranyl diphosphate synthases (gpps), with the best combination achieving ~28 mg/l of pinene. we spec ... | 2014 | 24679043 |
| chemical and morphological characteristics of key tree species of the carpathian mountains. | concentrations of al, b, ca, cu, fe, k, mg, mn, n, na, p, s and zn in the foliage of white fir (abies alba), norway spruce (picea abies) and common beech (fagus sylvatica) from 25 sites of the carpathian mts. forests (czech republic, poland, romania, slovakia and ukraine) are discussed in a context of their limit values. s/n ratio was different from optimum in 90% of localities when compared with the european limit values. likewise we found increase of fe and cu concentrations compared with thei ... | 2004 | 15046839 |
| a montane mediterranean climate supports year-round photosynthesis and high forest biomass. | the mid-elevation forest of california's sierra nevada poses a bioclimatic paradox. mid-elevation trees experience a montane mediterranean climate, with near-freezing winter days and rain-free summers. the asynchrony between warmth and water input suggests low primary production, limited by photosynthetic dormancy in winter cold, and again in summer and early autumn with drought, yet this forest is characterized by tall trees and high biomass. we used eddy covariance in a mid-elevation sierra st ... | 2016 | 26764269 |
| long-term effects of fire severity on oak-conifer dynamics in the southern cascades. | we studied vegetation composition and structure in a mixed conifer-oak ecosystem across a range of fire severity 10 years following wildfire. sample plots centered on focal california black oaks (quercus kelloggii) were established to evaluate oak and neighboring tree and shrub recovery across a gradient of fire severity in the southern cascade range, usa. shrub and oak resprouting was strongest around focal oaks where conifer mortality was greatest. linear modeling revealed negative relationshi ... | 2014 | 24640537 |
| estimating tree growth from complex forest monitoring data. | understanding tree growth as a function of tree size is important for a multitude of ecological and management applications. determining what limits growth is of central interest, and forest inventory permanent plots are an abundant source of long-term information but are highly complex. observation error and multiple sources of shared variation (spatial plot effects, temporal repeated measures, and a mosaic of sampling intervals) make these data challenging to use for growth estimation. we acco ... | 2013 | 24147402 |
| use of a single-tree simulation model to predict effects of ozone and drought on growth of a white fir tree. | a physiologically based, single-tree simulation model, tregro, was parameterized with existing phenological, allometric, and growth data and used to predict effects of ozone and drought on growth of a 53-year-old white fir (abies concolor (gord. & glend.) lindl. ex hildebr.) tree following a 3-year model simulation. multiple experimental simulations were conducted to assess the individual and interactive effects of ozone (o(3)) exposure and drought on growth of white fir. the effects of o(3) wer ... | 2000 | 12651472 |
| patterns of induced and constitutive monoterpene production in conifer needles in relation to insect herbivory. | studies were conducted to determine whether herbivore-induced synthesis of monoterpenes occurs in the needles of ponderosa pine (pinus ponderosa lawson), lodgepole pine (p. contorta douglas var. latifolia engelmann), white fir (abies concolor lindl. and gordon) and engelmann spruce [picea engelmanii (parry) engelm.]. in the needles of all species except engelmann spruce, simulated herbivory significantly induced the activity of monoterpene cyclases 4-8 days after wounding. in ponderosa pine, rea ... | 1998 | 28307902 |
| comparative studies of delignification caused by ganoderma species. | isolates of six species of ganoderma in the g. lucidum complex were evaluated for their ability to decay wood of quercus hypoleucoides a. camus and abies concolor (gord. and glend.) lindl. ex. hildebr. by using in vitro agar block decay tests. morphological, ultrastructural, and chemical studies of decayed wood were used to determine the extent of delignification or simultaneous decay caused by each species of ganoderma. all species decayed both white fir and oak wood; however, less percent weig ... | 1990 | 16348229 |
| interactions among phytophagous insect species colonizing cones of white fir (abies concolor). | the insect complex colonizing white fir (abies concolor [gord. and glend.] lindl.) cones is composed of eleven species that can be separated into three feeding guilds: the seed-mining guild, megastigmus pinus parfitt, m. rafni hoffmeyer, earomyia abietum mcalpine; the cone-and seed-mining guild, dioryctria abietivorella grote, eucosma prob. siskiyouana (kearfoot), cydia prob. bracteatana (fernald), barbara sp.; the scale-and bract-feeding guild, asynapta hokinsi (felt), dasineura prob. abiesemia ... | 1989 | 28312165 |
| variation and selection in western montane species ii. variation within and between populations of white firon an elevational transect. | four populations of abies concolor, white fir, were sampled along an elevational transect in the central sierra nevada mountains of california. this paper is based on data taken during the first two years' growth in a nearby nursery at placerville, california. ten of the thirteen growth, size, and needle morphological characteristics had significant differences between population samples, while eleven characteristics had significant differences between open-pollinated families within the populat ... | 1976 | 24414316 |
| the natural phytochemical dehydroabietic acid is an anti-aging reagent that mediates the direct activation of sirt1. | dehydroabietic acid (daa) is a naturally occurring diterpene resin acid of confers, such as pinus species (p. densiflora, p. sylvestris) and grand fir (abies grandis), and it induces various biological actions including antimicrobial, antiulcer, and cardiovascular activities. the cellular targets that mediate these actions are largely unknown yet. in this report, we suggest that daa is an anti-aging reagent. daa has lifespan extension effects in caenorhabditis elegans, prevents lipofuscin accumu ... | 2015 | 25976661 |
| engineering limonene and bisabolene production in wild type and a glycogen-deficient mutant of synechococcus sp. pcc 7002. | the plant terpenoids limonene (c10h16) and α-bisabolene (c15h24) are hydrocarbon precursors to a range of industrially relevant chemicals. high-titer microbial synthesis of limonene and α-bisabolene could pave the way for advances in in vivo engineering of tailor-made hydrocarbons, and production at commercial scale. we have engineered the fast-growing unicellular euryhaline cyanobacterium synechococcus sp. pcc 7002 to produce yields of 4 mg l(-1) limonene and 0.6 mg l(-1) α-bisabolene through h ... | 2014 | 25152894 |
| biosynthesis of pinene from glucose using metabolically-engineered corynebacterium glutamicum. | pinene is a monoterpenes (c10) that is produced in a genetically-engineered microbial host for its industrial applications in fragrances, flavoring agents, pharmaceuticals, and biofuels. herein, we have metabolically-engineered corynebacterium glutamicum, to produce pinene and studied its toxicity in c. glutamicum. geranyl diphosphate synthases (gpps) and pinene synthases (ps), obtained from pinus taeda and abies grandis, were co-expressed with over-expressed native 1-deoxy-d-xylulose-5-phosphat ... | 2014 | 24930112 |
| sensitivity of whole wood stable carbon and oxygen isotope values to milling procedures. | milling of wood samples is a widely applied preparation method for pooling tree-rings from different trees or periods of several years for determination of δ(13)c and δ(18)o values. in this study, whole wood samples were milled using different procedures in order to evaluate potential effects of this preparation method on δ(13)c and δ(18)o values. | 2014 | 24797948 |
| constraining 3-pg with a new δ13c submodel: a test using the δ13c of tree rings. | a semi-mechanistic forest growth model, 3-pg (physiological principles predicting growth), was extended to calculate δ(13)c in tree rings. the δ(13)c estimates were based on the model's existing description of carbon assimilation and canopy conductance. the model was tested in two ~80-year-old natural stands of abies grandis (grand fir) in northern idaho. we used as many independent measurements as possible to parameterize the model. measured parameters included quantum yield, specific leaf area ... | 2014 | 23663114 |
| grassland restoration with and without fire: evidence from a tree-removal experiment. | forest encroachment threatens the biological diversity of grasslands globally. positive feedbacks can reinforce the process, affecting soils and ground vegetation, ultimately leading to replacement of grassland by forest species. we tested whether restoration treatments (tree removal, with or without fire) reversed effects of nearly two centuries of encroachment by abies grandis and pinus contorta into dry, montane meadows in the cascade range, oregon, usa. in nine, 1-ha plots containing a patch ... | 2012 | 22611845 |
| insights into diterpene cyclization from structure of bifunctional abietadiene synthase from abies grandis. | abietadiene synthase from abies grandis (agas) is a model system for diterpene synthase activity, catalyzing class i (ionization-initiated) and class ii (protonation-initiated) cyclization reactions. reported here is the crystal structure of agas at 2.3 å resolution and molecular dynamics simulations of that structure with and without active site ligands. agas has three domains (α, β, and γ). the class i active site is within the c-terminal α domain, and the class ii active site is between the n ... | 2012 | 22219188 |
| structure of a three-domain sesquiterpene synthase: a prospective target for advanced biofuels production. | the sesquiterpene bisabolene was recently identified as a biosynthetic precursor to bisabolane, an advanced biofuel with physicochemical properties similar to those of d2 diesel. high-titer microbial bisabolene production was achieved using abies grandis α-bisabolene synthase (agbis). here, we report the structure of agbis, a three-domain plant sesquiterpene synthase, crystallized in its apo form and bound to five different inhibitors. structural and biochemical characterization of the agbis ter ... | 2011 | 22153510 |
| investigating the conservation pattern of a putative second terpene synthase divalent metal binding motif in plants. | terpene synthases (tps) require divalent metal ion co-factors, typically magnesium, that are bound by a canonical ddxxd motif, as well as a putative second, seemingly less well conserved and understood (n/d)dxx(s/t)xxxe motif. given the role of the ser/thr side chain hydroxyl group in ligating one of the three catalytically requisite divalent metal ions and the loss of catalytic activity upon substitution with ala, it is surprising that gly is frequently found in this 'middle' position of the pu ... | 2009 | 19201430 |
| genetic structure of heterobasidion annosum in white fir mortality centers in california. | abstract the structure of heterobasidion annosum populations was studied in 15 mixed-conifer sites in central and northern california. study sites displayed mortality of white fir trees in enlarging discrete patches (mortality centers). at each site, fungal genotypes were defined by somatic compatibility tests. in two sites, further genetic and molecular analyses were performed on field genotypes and on homokaryons obtained by dedikaryotization of field heterokaryons. isolates were found to be c ... | 1999 | 18944689 |
| wound-induced terpene synthase gene expression in sitka spruce that exhibit resistance or susceptibility to attack by the white pine weevil. | we analyzed the expression pattern of various terpene synthase (tps) genes in response to a wounding injury applied to the apical leader of sitka spruce (picea sitchensis bong. carr.) genotypes known to be resistant (r) or susceptible (s) to white pine weevil (pissodes strobi peck.) attack. the purpose was to test if differences in constitutive or wound-induced tps expression can be associated with established weevil resistance. all wounding treatments were conducted on 9-year-old r and s trees ... | 2006 | 16415217 |
| mutational analysis of a monoterpene synthase reaction: altered catalysis through directed mutagenesis of (-)-pinene synthase from abies grandis. | two monoterpene synthases, (-)-pinene synthase and (-)-camphene synthase, from grand fir (abies grandis) produce different product mixtures despite having highly homologous amino acid sequences and, presumably, very similar three-dimensional structures. the major product of (-)-camphene synthase, (-)-camphene, and the major products of (-)-pinene synthase, (-)-alpha-pinene, and (-)-beta-pinene, arise through distinct mechanistic variations of the electrophilic reaction cascade that is common to ... | 2005 | 15978541 |
| altering product outcome in abies grandis (-)-limonene synthase and (-)-limonene/(-)-alpha-pinene synthase by domain swapping and directed mutagenesis. | (-)-(4s)-limonene synthase (ls) and (-)-(4s)-limonene/(-)-(1s, 5s)-alpha-pinene synthase (lps) from grand fir (abies grandis) exhibit nearly 91% sequence identity (93% similarity) at the amino acid level, yet produce very different mixtures of monoterpene olefins. to elucidate critical amino acids involved in determining monoterpene product distribution, a combination of domain swapping and reciprocal site-directed mutagenesis was carried out between these two enzymes. exchange of the predicted ... | 2004 | 15081895 |
| bifunctional abietadiene synthase: free diffusive transfer of the (+)-copalyl diphosphate intermediate between two distinct active sites. | abietadiene synthase (as) catalyzes two sequential, mechanistically distinct cyclizations in the conversion of geranylgeranyl diphosphate to a mixture of abietadiene double bond isomers as the initial step of resin acid biosynthesis in grand fir (abies grandis). the first reaction converts geranylgeranyl diphosphate to the stable bicyclic intermediate (+)-copalyl diphosphate via protonation-initiated cyclization. in the second reaction, diphosphate ester ionization-initiated cyclization generate ... | 2001 | 11552804 |
| genomic organization of plant terpene synthases and molecular evolutionary implications. | terpenoids are the largest, most diverse class of plant natural products and they play numerous functional roles in primary metabolism and in ecological interactions. the first committed step in the formation of the various terpenoid classes is the transformation of the prenyl diphosphate precursors, geranyl diphosphate, farnesyl diphosphate, and geranylgeranyl diphosphate, to the parent structures of each type catalyzed by the respective monoterpene (c(10)), sesquiterpene (c(15)), and diterpene ... | 2001 | 11404343 |
| partial purification and characterization of the short-chain prenyltransferases, gernayl diphospate synthase and farnesyl diphosphate synthase, from abies grandis (grand fir). | in the conifer abies grandis (grand fir), a secreted oleoresin rich in mono-, sesqui-, and diterpenes serves as a constitutive and induced defense against insects and pathogenic fungi. geranyl diphosphate (gpp) and farnesyl diphosphate (fpp) synthase, two enzymes which form the principal precursors of the oleoresin mono- and sesquiterpenes, were isolated from the stems of 2-year-old grand fir saplings. these enzymes were partially purified by sequential chromatography on deae-sepharose, mono-q, ... | 2001 | 11368347 |
| stereochemistry of the cyclization-rearrangement of (+)-copalyl diphosphate to (-)-abietadiene catalyzed by recombinant abietadiene synthase from abies grandis. | [reaction: see text] syntheses and enzymatic cyclizations of 8alpha-hydroxy-17-nor copalyl diphosphate (8a), (15r)-[15-2h1] 8b, and (15r,17e)-[15-3h1,17-2h1] copalyl diphosphate ([2h,3h] 2) catalyzed by recombinant abietadiene synthase (ras) gave 17-nor manoyl oxide (9a), (16e)-[16-2h1] 9b, and (15s,16r)-[16-2h1,16-3h1] abietadiene ([2h1,3h1] 4), respectively. these and other results indicate that conversion of cpp (2) to abietadiene (4) occurs by anti s(n)' cyclization to a sandaracopimar-15-en ... | 2000 | 10814381 |
| resin-based defenses in conifers. | bark beetle infestation and associated fungal infection are a serious disease problem in conifer species. conifers have evolved elaborate, constitutive and inducible, terpene-based defense mechanisms to deter insect pests and their symbiotic fungal pathogens. this process involves the secretion of oleoresin, a complex mixture of monoterpenes, sesquiterpenes and diterpenoid acids. induced oleoresinosis in grand fir (abies grandis) provides a model system for studying the regulation of defensive t ... | 1999 | 10322558 |
| regulation of oleoresinosis in grand fir (abies grandis). differential transcriptional control of monoterpene, sesquiterpene, and diterpene synthase genes in response to wounding | grand fir (abies grandis lindl.) has been developed as a model system for the study of wound-induced oleoresinosis in conifers as a response to insect attack. oleoresin is a roughly equal mixture of turpentine (85% monoterpenes [c10] and 15% sesquiterpenes [c15]) and rosin (diterpene [c20] resin acids) that acts to seal wounds and is toxic to both invading insects and their pathogenic fungal symbionts. the dynamic regulation of wound-induced oleoresin formation was studied over 29 d at the enzym ... | 1998 | 9536068 |
| induced oleoresin biosynthesis in grand fir as a defense against bark beetles. | grand fir (abies grandis) saplings and derived cell cultures are useful systems for studying the regulation of defensive oleoresinosis in conifers, a process involving both the constitutive accumulation of resin (pitch) in specialized secretory structures and the induced production of monoterpene olefins (turpentine) and diterpene resin acids (rosin) by nonspecialized cells at the site of injury. the pathways and enzymes involved in monoterpene and diterpene resin acid biosynthesis are described ... | 1995 | 7753778 |
| regulation of oleoresinosis in grand fir (abies grandis) (coordinate induction of monoterpene and diterpene cyclases and two cytochrome p450-dependent diterpenoid hydroxylases by stem wounding). | oleoresin (pitch) is a defensive secretion composed of monoterpene olefins (turpentine) and diterpene resin acids (rosin) that is produced in grand fir (abies grandis lindl.) stems in response to wounding. monoterpene and diterpene biosynthesis are coordinately induced in wounded stems as determined by monitoring the activity of monoterpene and diterpene cyclases, as well as two cytochrome p450-dependent diterpenoid hydroxylases involved in the formation of ([mdash])-abietic acid, the principal ... | 1994 | 12232380 |
| oleoresinosis in grand fir (abies grandis) saplings and mature trees (modulation of this wound response by light and water stresses). | the stem content of diterpene resin acids (rosin) increases dramatically following wounding of grand fir (abies grandis) saplings, but the level of monoterpene olefins (turpentine) in the stem decreases following injury, in spite of a significant increase in monoterpene cyclase (synthase) activity. however, this observation was explained when rapid evaporative losses of the volatile monoterpenes from the wound site was demonstrated by trapping experiments, a finding consistent with a role of tur ... | 1993 | 12231755 |
| wound-inducible pinene cyclase from grand fir: purification, characterization, and renaturation after sds-page. | the major wound-inducible monoterpene synthase (cyclase) of grand fir (abies grandis) stems transforms geranyl pyrophosphate to both (-)-alpha-pinene (40%) and (-)-beta-pinene (60%). the enzyme was purified to apparent homogeneity by anion-exchange and hydrophobic interaction chromatography, coupled to discontinuous native polyacrylamide gel electrophoresis at neutral ph and polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (also at neutral ph) followed by renaturation ... | 1992 | 1731633 |
| characterization of the constitutive and wound-inducible monoterpene cyclases of grand fir (abies grandis). | monoterpene cyclase activity is greatly increased in grand fir (abies grandis) sapling stems in response to wounding and the composition of the cyclic olefin mixture generated differs from that produced constitutively as determined by radio gas-liquid chromatography. cell-free extracts from wounded stems and from non-wounded controls were systematically compared for monoterpene cyclase activities following partial purification and separation of these enzymes by anion-exchange chromatography (mon ... | 1991 | 1898071 |
| the population biology of bromus tectorum in forests: distinguishing the opportunity for dispersal from environmental restriction. | with increasing elevation and corresponding changes in the macroclimate, forest zones in the intermountain region of western north america are often dominated in turn by pinus ponderosa, pseudotsuga menziesii, abies grandis, an thuja plicata. bromus tectorum (cheatgrass), and introduced annual grass now abundant in the region's steppe, is uncommon in mature stands representative of these forest zones. in order to determine whether b. tectorum is largely excluded from these forests by insufficien ... | 1990 | 28312969 |
| changes in terpene production following nitrogen fertilization of grand fir (abies grandis (dougl.) lindl.) seedlings. | of ten terpenes that comprise most of the volatiles of grand fir foliage only four were affected by addition of nitrogen. levels of beta-phellandrene, camphene and bornyl acetate and terpinolene were significantly reduced with nitrogen added to the equivalent amount of 44.8 g/m(2). a quantity of 22.4 g/m(2) did not affect terpene production. several populations were examined and these did not respond consistently on a regional basis, yet a significant interaction effect was apparent between trea ... | 1989 | 28312832 |
| thermochemical pretreatment of lignocellulose to enhance methane fermentation: ii. evaluation and application of pretreatment model. | a model was developed and evaluated as a tool for predicting the formation of soluble products from staged thermochemical treatment of lignocellulosic materials under acidic conditions typical of autohydrolysis. the model was used to predict the general trend of hemi-cellulose and cellulose hydrolysis between ph 2 and 4 and temperatures of 170-230 degrees c, and results were compared with experimental data. when the model was evaluated for this range of temperatures and ph values, results indica ... | 1988 | 18581564 |