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PubMed1967

Effect of various essential oils isolated from Douglas fir needles upon sheep and deer rumen microbial activity.

The effects of essential oils isolated from Douglas fir needles on sheep and deer rumen microbial activity were tested by use of an anaerobic manometric technique. Rumen microorganisms were obtained from a sheep which had been fed mainly on alfalfa hay and dried range grass. One deer used in this study had access to Douglas fir trees the year around, whereas the other deer had no access to Douglas fir. All of the monoterpene hydrocarbons isolated from Douglas fir needles-alpha-pinene, beta-pinene, limonene, myrcene, camphene, Delta(3)-carene, and terpinolene-promoted only slightly or had no effect on deer rumen microbial activity, whereas all of them promoted activity in sheep rumen microbes, except Delta(3)-carene and terpinolene, which inhibited activity. Of the oxygenated monoterpenes, all monoterpene alcohols-alpha-terpineol, terpinen-4-ol, linalool, citronellol, and fenchyl alcohol-strongly inhibited the rumen microbial activity of both sheep and deer. Monoterpene esters (bornyl acetate) produced mild inhibition for both sheep and deer microbes, and citronellyl acetate inhibited rumen microbial activity in sheep, whereas it promoted activity in both deer. Monoterpene aldehyde (citronellal) inhibited the activity of rumen microbes from both sheep and deer having no access to Douglas fir from the Hopland Field Station, whereas they produced no effect upon the deer having access to Douglas fir from the Masonite forest. Rumen microbial activity for sheep and deer was promoted slightly with aliphatic ester (ethyl-n-caproate). There was a marked difference between sheep and deer rumen microbes as affected by addition of the various essential oils. The monoterpene hydrocarbons promoted activity more on sheep rumen microbes than on deer, and the monoterpene alcohols inhibited sheep rumen microbial activity more than that of deer. Furthermore, the deer rumen microbes from Hopland Field Station were affected more than the deer from Masonite forest.

Animals↗
PubMed2000

[Dynamics of phenolics content of Chinese fir stump-roots and the rhizosphere soil and it's allelopathy].

Studies on the releasing pattern of phenolics during the decomposition of Chinese fir stump-root and on its allelopathy show that the phenolics contents in stump-roots decreased with their decomposition. Roots had a higher content of phenolics than heart stumps, and edge stumps had the least. The phenolics was released during decomposition, and accumulated in the soils around stump-roots. Pot culture experiment showed that phenolics affected the germination of Chinese fir seeds. The correlation analysis between the density of Chinese fir stump-root and the tree height and base diameter (BD) of its saplings proved that Chinese fir stump-roots had a negative impact on the growth of the next generation of Chinese fir plantations. It is suggested that the traditional operation of Chinese fir plantations should be reformed, and the stump-roots should be cleared from woodland before reforestation.

Phenols↗
PubMed2005

[Dynamics of soil active organic matter in Chinese fir plantations].

Soil active organic matter is the main source of soil nutrients, and plays an important role in the formation and stabilization of soil aggregate. Chinese fir (Cunninghamia lanceolata) is the most important fast-growing timber tree species in southern China, but its continuous plantation has caused soil deterioration. The study on the active fractions of soil organic matter under the first and second generation plantations of Chinese fir and the native broad-leaved forest at Huitong Experimental Station of Forest Ecology, Chinese Academy of Sciences, in Hunan Province showed that their contents were higher under native broad-leaved forest than under Chinese fir plantations, and higher under the first than under the second generation plantation. The content of soil active organic carbon (SAOC), microbial biomass carbon (MBC), water-soluble organic carbon (WSOC) and water-soluble carbohydrate (WSC) was 18.79 g x kg(-1), 421.7 mg x kg(-1), 252.2 mg x kg(-1) and 136.3 mg x kg(-1) under the first generation plantation of Chinese fir, and 22.31 g x kg(-1), 800.5 mg x kg(-1), 361.1 mg x kg(-1) and 220.1 mg x kg(-1) under the native broad-leaved forest, respectively. The corresponding values under the second generation plantation of Chinese fir were 73.6%, 87.9%, 66.3% and 53.2% of those under the first generation plantation of Chinese fir. The results also indicated that there existed some extent correlations among the active fractions of soil organic matter, and higher correlations between soil microbial biomass carbon and other active fractions of soil organic matter.

Carbon↗
PubMed1995

A mutation hotspot in the chloroplast genome of a conifer (Douglas-fir: Pseudotsuga) is caused by variability in the number of direct repeats derived from a partially duplicated tRNA gene.

We determined the DNA sequence of a 2.7-kb cpDNA XbaI fragment from douglas-fir [Pseudotsuga menziesii (Mirb.) Franco]. RFLPs revealed by the 2.7-kb XbaI clone were observed to vary up to 1 kb among species within the genus Pseudotsuga and up to 200 bp among trees of P. menziesii. The polymerase chain reaction (PCR) allowed the locus of polymorphism to be identified, and the variable region was then sequenced in a second Douglas-fir tree, a single tree of a related species, Japanese Douglas-fir (P. japonica), and in a species lacking a mutation hotspot in the region, Pinus radiata (Monterey pine). The locus of polymorphism is characterized by hundreds of base pairs of imperfect, tandem direct repeats flanked by a partially duplicated and an intact trn Y-GUA gene. The duplication is direct in orientation and consists of 43 bp of the 3' end of trnY and 25 bp of its 3' flanking sequence. Tandem repeats show high sequence similarity to a 27-bp region of the trnY gene that overlaps one end of the duplication. The two trees of Douglas-fir sequenced differed by a single tandem repeat unit, whereas these trees differed from the Japanese Douglas-fir sequenced by approximately 34 repeat units. Repetitive DNA in the Pseudotsuga cpDNA hotspot was most likely generated at the time of the partial trnY gene duplication and these sequences expanded by slipped-strand mispairing and unequal crossing-over.

Base Sequence↗
PubMed2004

Functional analysis of a Douglas-fir metallothionein-like gene promoter: transient assays in zygotic and somatic embryos and stable transformation in transgenic tobacco.

Douglas-fir (Pseudotsuga menziesii [Mirb] Franco) metallothionein (PmMT) cDNA encodes a novel cysteine- and serine-rich MT, indicating a new subtype or prototype MT from which other plant MTs may have evolved. A genomic library of Douglas-fir was screened using MT cDNA probes, and genomic sequences that mediate tissue-specific, temporal as well as inducible expression of the embryo-specific MT-gene were analyzed. The promoter region of the PmMT genomic clone (gPmMT) contained a hexameric G-box, two putative ethylene-responsive elements and an inverted repeat of a motif similar to the core metal regulatory element. Interestingly, comparison of the upstream region of Douglas-fir gPm2S1 and gPmMTa genes revealed a conserved motif, CATTATTGA, not found in any known angiosperm gene promoter. Chimeric gene constructs containing a series of deletions in the gPmMTa promoter fused to the uidA reporter gene were assayed in Douglas-fir and transgenic tobacco (Nicotiana tabacum L.). Transient-expression assays in Douglas-fir megagametophyte and zygotic embryos indicated that the sequence -190 to +88 of gPmMTa was sufficient to drive the expression of the reporter gene and that the 225-bp fragment (-677 to -453) contained sequences necessary for high-level expression. In transgenic tobacco seedlings the beta-glucuronidase activity was localized in the vacuolar tissue and proliferating tissue of the auxiliary buds and stem elongation zone. The gPmMTa promoter was not active in the seeds of transgenic tobacco or in the roots of seedlings up to 3 weeks old. Detailed studies of transient expression and stable transformation provided important information on evolutionary conservation as well as novel features found in the conifer promoter. This is the first report of an MT-like gene promoter from conifers.

Amino Acid Sequence↗
PubMed1994

Applications of least-squares FIR filters to virtual acoustic space.

A virtual acoustic space (VAS) employs the localization cues specified by the direction-dependent 'free-field to eardrum transfer function' (FETF) to synthesize sound-pressure waveforms present near the tympanum. The combination of a VAS and the earphone delivery of synthesized waveforms is useful to study parametrically the neural mechanisms of directional hearing. The VAS-earphone procedure requires accurate FETF estimation from free-field measurements and appropriate compensation for the undesirable spectral characteristics of the closed-field earphone sound delivery and measurement systems. Here we describe how specially designed finite-impulse-response (FIR) filters improve these two operations. The coefficients of an FIR filter are determined using a least-squares error criterion. The least-squares FIR filter is implemented entirely in the time domain and avoids the usual problems with division inherent in a frequency domain approach. The estimation of an FETF by a least-squares FIR filter is veracious since its impulse response can recover signals that were recorded near the eardrum in the free field with a very high fidelity. The correlation coefficient between recorded and recovered time waveforms typically exceeds 0.999. Similarly, least-squares FIR filters prove excellent in compensating closed-field sound systems since comparisons of waveforms delivered by a compensated earphone to their corresponding predistorted signals yield correlation coefficients that exceed 0.99 on average.

Acoustic Stimulation↗
PubMed2004

2S storage protein gene of Douglas-fir: characterization and activity of promoter in transgenic tobacco seeds.

To date a few sequences regulating expression of conifer seed-specific genes have been reported. To characterize Douglas-fir (Pseudotsuga menziesii [Mirb] Franco) 2S albumin storage protein genes, a genomic DNA sequence containing upstream promoter sequences was isolated by screening a Douglas-fir genomic library. Sequence analysis of the Douglas-fir gPm2S1 promoter revealed the presence of RY-repeated elements (GCATGC), and multiple E-box motifs (CANNTG) and ACGT-core elements, features characteristic of 2S storage protein genes in angiosperms. When fused to the GUS reporter gene, the 1.16 kb Douglas-fir 2S promoter sequence was sufficient to direct transient expression in both developing Douglas-fir embryos and maternally derived haploid megagametophytes. Analysis of this promoter construct in transgenic tobacco showed that expression was restricted to embryo and endosperm in developing seeds and was not detected in vegetative tissues of two-week-old seedlings. These results strongly suggest that both structural and regulatory elements as well as upstream signaling components controlling the expression of 2S albumin genes are highly conserved during evolution.

2S Albumins, Plant↗
PubMed1993

A comparison of red spruce and balsam fir shoot structures.

I compared the shoot structures of high-elevation red spruce (Picea rubens Sarg.) and balsam fir (Abies balsamea (L.) Mill.). Needle widths, thicknesses and perimeters were measured to estimate total leaf areas from measured projected leaf areas. Measured needle perimeter/needle width ratios differed significantly from estimated ratios that assumed needles were either rhomboidal or elliptical in cross section. The vertical and horizontal silhouette shoot area to total leaf area ratios (STAR(v) and STAR(h)) of the two species were negatively correlated with needle packing and canopy height. Red spruce had higher values of STAR(v) than balsam fir at each canopy height, but STAR(v) declined with canopy height at a similar rate in the two species. The STAR(h) values of the two species did not differ significantly at a given canopy height. Needle packing increased with canopy height at the same rate in the two species. Needle weight increased in red spruce and decreased in balsam fir with increased needle packing, but showed no significant dependence on canopy height. Red spruce had higher values of STAR(h) than balsam fir at low values of needle packing, but STAR(h) values converged at high values of needle packing. The generally comparable values of STAR, along with similar needle diameters, may imply that red spruce and balsam fir have similar collection efficiencies of wet and dry particles. Measurements of STAR may be used to estimate leaf area indices (LAI) more accurately when using indirect techniques.

Journal Article↗
PubMed2000

Vertical gradients in photosynthetic light response within an old-growth Douglas-fir and western hemlock canopy.

We examined needle-level light response of photosynthesis across a vertical light gradient within 45-55-m-tall western hemlock (Tsuga heterophylla (Raf.) Sarg.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees growing in a 400-500-year-old mixed species stand. We determined: (1) whether light-saturated photosynthetic rates, light compensation points, and respiration rates varied from the upper to the lower canopy, and (2) if light-saturated photosynthetic rates, light compensation points, and respiration rates varied between Douglas-fir and western hemlock. Over a 25-m gradient from the canopy top to the lower canopy, mean light-saturated photosynthetic rates, light compensation points, and respiration rates declined in overstory Douglas-fir and western hemlock needles, paralleling a 65% decline in the mean daily photosynthetic photon flux density (PPFD). At the canopy top, increasing light-saturated photosynthetic rates relative to lower canopy needles increased carbon uptake at high PPFD. In the lower canopy, reduced respiration rates relative to upper canopy needles increased carbon uptake at low PPFD by reducing the light compensation point. At all canopy positions, western hemlock had lower mean light-saturated photosynthetic rates, light compensation points and respiration rates than Douglas-fir. As a result, western hemlock had higher net photosynthetic rates at low PPFD, but lower net photosynthetic rates at high PPFD compared with Douglas-fir.

Journal Article↗
PubMed1980

Some effects of douglas fir terpenes on certain microorganisms.

The Douglas fir terpene alpha-pinene was shown to inhibit the growth of a variety of bacteria and a yeast. Other terpenes of the Douglas fir, including limonene, camphene, and isobornyl acetate, were also inhibitory to Bacillus thuringiensis. All terpenes were inhibitory at concentrations normally present in the fir needle diet of Douglas fir tussock moth larvae. The presence of such terpenes in the diet of these insects was found to strongly influence the infectivity of B. thuringiensis spores for the Douglas fir tussock moth larvae. The terpene alpha-pinene destroyed the cellular integrity and modified mitochondrial activity in certain microorganisms.

Journal Article↗
PubMed2001

[Decomposition interaction of mixed litter between Chinese fir and various accompanying plant species].

Studies on the decomposition of mixed litter between Chinese fir and 8 accompanying plant species showed that the decomposition of Chinese fir litter was promoted to different degrees by 8 mixed plant species, in which Angiopteris fokiensis had the greatest effect, while Schima superba had certain promotion first, but then, weak inhibition. The order of promotion was Angiopteris fokiensis > Maesa japonica > Ficus simplicissima > Woodwardia japonica > Boehmeria nivea > Castanopsis fargesii > Castanopsis fissa > Dicranopteris dicotoma. Chinese fir litter had a certain inhibition to litter decomposition of Schima superba and Castanopsis fissa, and certain promotion to litter decomposition of Castanopsis fargesii, but the interactions were not significant. There existed an interaction between Chinese fir and some plant species in the course of mixed decomposition. Therefore, rational protection and restoration of understory plant was important to fasten nutrient cycling of Chinese fir plantation ecosystem and to maintain soil fertility.

Abies↗
PubMed2002

[Effect of vanillin and P-hydroxybenzoic acid on physiological characteristics of Chinese fir seedlings].

Effects of vanillin and P-hydroxybenzoic acid at different concentrations on physiological characteristic of Chinese fir seedlings were studied by potted experiment. The results showed that 10 mmol.L-1 and 1 mmol.L-1 of two kinds of phenolics significantly reduced the content of chlorophyll, rate of photosynthesis and root activity, and that the higher the concentration of vanillin and P-hydroxybenzoic acid, the more the physiological activities was inhibited. By treatment with 1 and 10 mmol.L-1 vanillin, Chinese fir seedlings reduced its photosynthesis rate 25.1% and 37.0%, transpiration rate 20.3% and 37.0%, stomata conductance 33.7% and 46.8% and root activity 51.6% and 78.8%, respectively. The results suggested that vanillin and P-hydroxybenzoic acid accumulated in the soil by continuous cropping of Chinese fir may have some allelopathic effect on the seedlings of Chinese fir and the effect is one of the factors leading to the low productivity of continuously cropped Chinese fir forest.

Antioxidants↗
PubMed2004

[A comparative study on soil fauna in native secondary evergreen broad-leaved forest and Chinese fir plantation forests in subtropics].

In this study, we investigated the response of soil animal communities to the replacement of native secondary forest by Chinese fir plantation forest and successive rotation of Chinese fir in subtropics. Three adjacent forest stands, i.e., native secondary evergreen broad-leaved forest stand (control) and Chinese fir plantation stands of first (20 yr) and second (20 yr) rotations were selected for the comparison of soil fauna. All animals were extracted from the floor litter and 0-15 cm soil layer of the stands in Summer, 2003 by using Tullgren method, wet funnel method and hand-sorting method. Compared to two Chinese fir plantation forests, the native secondary evergreen broad-leaved forest had a higher abundance and a higher taxonomic diversity of animals in soil and litter, but there were no significant differences in the biomass and productivity of soil fauna between all study stands. The abundance or diversity did not differ significantly between the first rotation and second rotation stands, too. The results supported that vegetation cover might be one of the main forces driving the development of soil animal communities, and the effect of successive rotation of Chinese fir on the development of soil fauna was a slow-running process.

Animals↗
PubMed1999

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 as substrates to generate the large diversity of carbon skeletons characteristic of the terpenoid resin of conifers. A large and diverse gene family of grand fir terpene synthases has been cloned and cDNAs are actively expressed in Escherichia coli for enzyme characterization. The monophyletic group of grand fir monoterpene, sesquiterpene and diterpene synthases represents both constitutively expressed and inducible genes encoding single product and multiple product enzymes. Several events of gene duplication and functional specialization of new synthases occurred during the evolution of terpenoid biosynthesis in grand fir, and gave rise to the enormous diversity and variability of this ancient and successful plant defence against herbivores and pathogens. The review concludes with a perspective of the biotechnological applications of terpenoid synthases for the genetic engineering of agricultural crops and forest trees.

Alkyl and Aryl Transferases↗
PubMed1999

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 conserved regions of existing monoterpene synthases and anticipated to amplify a 1000-bp fragment, unexpectedly yielded a 300-bp fragment with sequence reminiscent of a terpenoid synthase. Utilization of this amplicon as a hybridization probe afforded four new, full-length cDNA species from a wounded fir stem cDNA library that appeared to encode four distinct monoterpene synthases. Expression in Escherichia coli, followed by enzyme assay with geranyl diphosphate (C(10)), farnesyl diphosphate (C(15)) and geranylgeranyl diphosphate (C(20)), and analysis of the terpene products by chiral phase gas chromatography and mass spectrometry confirmed that these sequences encoded four new monoterpene synthases, including (-)-camphene synthase, (-)-beta-phellandrene synthase, terpinolene synthase, and an enzyme that produces both (-)-limonene and (-)-alpha-pinene. The deduced amino acid sequences indicated these enzymes to be 618 to 637 residues in length (71 to 73 kDa) and to be translated as preproteins bearing an amino-terminal plastid targeting sequence of 50-60 residues. cDNA truncation to delete the transit peptide allowed functional expression of the "pseudomature" forms of these enzymes, which exhibited no change in product outcome as a result of truncation. Sequence comparison revealed that these new monoterpene synthases from grand fir are members of the Tpsd gene subfamily and resemble sesquiterpene (C(15)) synthases and diterpene (C(20)) synthases from conifers more closely than mechanistically related monoterpene synthases from angiosperm species. The availability of a nearly complete set of constitutive and inducible monoterpene synthases from grand fir (now numbering seven) will allow molecular dissection of the resin-based defense response in this conifer species, and detailed study of structure-function relationships among this large and diverse family of catalysts, all of which exploit the same stereochemistry in the coupled isomerization-cyclization reaction.

Amino Acid Sequence↗
PubMed2003

Genetic evaluation of alternative silvicultural systems in coastal montane forests: western hemlock and amabilis fir.

Genetic diversity and mating system were quantified for shelterwood, patch cut and green tree-retention silvicultural systems, and compared to adjacent old-growth. This is a component of a larger study conducted in montane old-growth forests of coastal British Columbia to evaluate the feasibility and ecological consequences of alternative silvicultural systems. The experiment includes replicated treatments representing a range of overstory removal adjacent to old-growth and clearcut areas. Based on 22 electrophoretically assayed loci, the effects of silvicultural systems on genetic parameters of amabilis fir (Abies amabilis and western hemlock (Tsuga heterophylla were assessed by comparing an average number of alleles per locus, the percent polymorphic loci, and observed and expected heterozygosity between parental populations and naturally regenerated progeny as well as among treatments. Genetic variation in natural regeneration was greater than in parental populations, especially for low-frequency alleles. Silvicultural treatments caused no significant differences in amabilis fir genetic-diversity parameters, while the shelterwood system resulted in lower observed and expected heterozygosity in western hemlock. Nei's genetic distance revealed that all parental populations were extremely similar. The two species had contrasting mating system dynamics with amabilis fir producing higher levels of correlated paternity and inbreeding with wider variation among individual tree outcrossing-rate estimates. Western hemlock had significant levels of correlated paternity only for the green tree and shelterwood treatments demonstrating family structuring inversely related to stand density. Inbreeding in western hemlock was significant but lower than that observed for amabilis fir with a J-shaped distribution for individual tree multilocus outcrossing-rate estimates. The pollination and dispersal mechanisms of the two species represent the most-likely factors causing these differences. Artificial regeneration may be utilized to augment the genetic resources of natural ingress.

Abies↗
PubMed2004

Native root xylem embolism and stomatal closure in stands of Douglas-fir and ponderosa pine: mitigation by hydraulic redistribution.

Hydraulic redistribution (HR), the passive movement of water via roots from moist to drier portions of the soil, occurs in many ecosystems, influencing both plant and ecosystem-water use. We examined the effects of HR on root hydraulic functioning during drought in young and old-growth Douglas-fir [ Pseudotsuga menziesii (Mirb.) Franco] and ponderosa pine ( Pinus ponderosa Dougl. Ex Laws) trees growing in four sites. During the 2002 growing season, in situ xylem embolism, water deficit and xylem vulnerability to embolism were measured on medium roots (2-4-mm diameter) collected at 20-30 cm depth. Soil water content and water potentials were monitored concurrently to determine the extent of HR. Additionally, the water potential and stomatal conductance ( g(s)) of upper canopy leaves were measured throughout the growing season. In the site with young Douglas-fir trees, root embolism increased from 20 to 55 percent loss of conductivity (PLC) as the dry season progressed. In young ponderosa pine, root embolism increased from 45 to 75 PLC. In contrast, roots of old-growth Douglas-fir and ponderosa pine trees never experienced more than 30 and 40 PLC, respectively. HR kept soil water potential at 20-30 cm depth above -0.5 MPa in the old-growth Douglas-fir site and -1.8 MPa in the old-growth ponderosa pine site, which significantly reduced loss of shallow root function. In the young ponderosa pine stand, where little HR occurred, the water potential in the upper soil layers fell to about -2.8 MPa, which severely impaired root functioning and limited recovery when the fall rains returned. In both species, daily maximum g(s) decreased linearly with increasing root PLC, suggesting that root xylem embolism acted in concert with stomata to limit water loss, thereby maintaining minimum leaf water potential above critical values. HR appears to be an important mechanism for maintaining shallow root function during drought and preventing total stomatal closure.

Disasters↗
PubMed1983

A small animal model study of perlite and fir bark dust on guinea pig lungs.

Fir bark (Abies) and perlite (noncrystalline silicate) dusts have been reported to cause pulmonary disease in humans. Guinea pigs were exposed to either fir bark or perlite dust in a special chamber. Severe pathologic changes occurred in the lungs, consisting of lymphoid aggregated and a perivascular inflammatory response. Both dusts caused similar changes although one was vegetable (fir bark) and the other mineral (perlite). Fir bark and perlite dust appeared to be more than just nuisance dusts.

Aluminum Oxide↗