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PubMed1993

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 turpentine as a solvent for the mobilization and deposition of rosin to seal the injury. Mature forest trees responded to stem wounding by the enhancement of monoterpene cyclization capacity in a manner similar to 2-year-old grand fir saplings raised in the greenhouse. Light and water stresses greatly reduced the constitutive level of monoterpene cyclase activity and abolished the wound-induced response. The diminution in monoterpene biosynthetic capacity was correlated with a dramatic decrease in cyclase protein as demonstrated by immunoblotting. Relief of stress conditions resulted in the restoration of cyclase activity (both constitutive and wound induced) to control levels. The results of these experiments indicate that grand fir saplings are a suitable model for studies of the regulation of defensive oleoresinosis in conifers.

Journal Article↗
PubMed1976

Indole-3-acetic Acid in Douglas Fir: Analysis by Gas-Liquid Chromatography and Mass Spectrometry.

We sought evidence for the occurrence and seasonal variation of indole-3-acetic acid (IAA) in shoots of Douglas fir (Pseudotsuga menziesii [Mirb.] Franco).Collections obtained in December and June were extracted with methanol and diethyl ether. Extracts were purified by solvent partitioning and with Sephadex LH-20. Qualitative and quantitative information was acquired by gas-liquid chromatography of methyl, trimethylsilyl, or both derivatives of plant extract components. Analysis was performed with polar (XE-60) and moderately polar (Hi-Eff-8-BP) stationary phases. Results from three collections demonstrated that IAA does occur in Douglas fir and that amounts vary seasonally. Mass analysis of the proposed endogenous IAA peak from two representative extracts supported gas-liquid chromatography data and established the presence of IAA in Douglas fir.

Journal Article↗
PubMed1987

Structure of Plant Cell Walls : XIX. Isolation and Characterization of Wall Polysaccharides from Suspension-Cultured Douglas Fir Cells.

The partial purification and characterization of cell wall polysaccharides isolated from suspension-cultured Douglas fir (Pseudotsuga menziesii) cells are described. Extraction of isolated cell walls with 1.0 m LiCl solubilized pectic polysaccharides with glycosyl-linkage compositions similar to those of rhamnogalacturonans I and II, pectic polysaccharides isolated from walls of suspension-cultured sycamore cells. Treatment of LiCl-extracted Douglas fir walls with an endo-alpha-1,4-polygalacturonase released only small, additional amounts of pectic polysaccharide, which had a glycosyl-linkage composition similar to that of rhamnogalacturonan I. Xyloglucan oligosaccharides were released from the endo-alpha-1,4-polygalacturonase-treated walls by treatment with an endo-beta-1,4-glucanase. These oligosaccharides included hepta- and nonasaccharides similar or identical to those released from sycamore cell walls by the same enzyme, and structurally related octa- and decasaccharides similar to those isolated from various angiosperms. Finally, additional xyloglucan and small amounts of xylan were extracted from the endo-beta-1,4-glucanase-treated walls by 0.5 n NaOH. The xylan resembled that extracted by NaOH from dicot cell walls in that it contained 2,4- but not 3,4-linked xylosyl residues. In this study, a total of 15% of the cell wall was isolated as pectic material, 10% as xyloglucan, and less than 1% as xylan. The noncellulosic polysaccharides accounted for 26% of the cell walls, cellulose for 23%, protein for 34%, and ash for 5%, for a total of 88% of the cell wall. The cell walls of Douglas fir were more similar to dicot (sycamore) cell walls than to those of graminaceous monocots, because they had a predominance of xyloglucan over xylan as the principle hemicellulose and because they possessed relatively large amounts of rhamnogalacturonan-like pectic polysaccharides.

Journal Article↗
PubMed1992

A repetitive proline-rich protein from the gymnosperm douglas fir is a hydroxyproline-rich glycoprotein.

Intact cell elution of suspension cultures derived from Douglas fir, Pseudotsuga menziesii (Mirbel) Franco, yielded two extensin monomers, the first hydroxyproline-rich glycoproteins (HRGPs) to be isolated from a gymnosperm. These HRGPs resolved on Superose-6 gel filtration. The smaller monomer was compositionally similar to angiosperm extensins like tomato P1. The larger monomer had a simple composition reminiscent of repetitive proline-rich proteins (RPRPs) from soybean cell walls and contained proline, hydroxyproline, and sugar; hence designated a proline-hydroxyproline-rich glycoprotein (PHRGP). The simple composition of the PHRGP implied a periodic structure which was confirmed by the simple chymotryptic map and 45-residue partial sequence of the major proline-hydroxyproline-rich glycoprotein chymotryptide 5: Lys-Pro-Hyp-Val-Hyp-Val-Ile-Pro-Pro-Hyp-Val-Val-Lys-Pro-Hyp-Hyp-Val- Tyr-Lys-Pro-Hyp-Val-Hyp-Val-Ile-Pro-Pro-Hyp-Val-Val-Lys-Pro-Hyp-Hyp- Val-Tyr-Lys-Ile-Pro-Pro(Hyp)-Val-Ile-Lys-Pro. Proline-hydroxyproline-rich glycoprotein chymotryptide 5 contained an 18-residue tandem repeat devoid of tetra(hydroxy)-proline or serine; it also contained two instances of the five-residue motif Hyp-Hyp-Val-Tyr-Lys and five of the general Pro-Pro-X-X-Lys motif, thereby establishing its homology with typical angiosperm RPRPs and extensins from tomato, petunia, carrot, tobacco, sugar beet, and Phaseolus. Unlike the nonglycosylated soybean RPRP, the highly purified Douglas fir PHRGP was lightly glycosylated, confirmed by a quantitative hydroxyproline glycoside profile, indicating that extensins can range from highly glycosylated hydroxyproline to little or no glycosylated hydroxyproline. Comparison of extensin sequence data strongly indicates that a major determinant of hydroxyproline glycosylation specificity is hydroxyproline contiguity: extensins with tetrahydroxyproline blocks are very highly arabinosylated (>90% hydroxyproline glycosylated), tri- and dihydroxyproline are less so, and single hydroxyproline residues perhaps not at all. Despite high yields of extensins eluted from intact cells, the Douglas fir cell wall itself was hydroxyproline poor yet remarkably rich in protein (>20%), again emphasizing the existence of other structural cell wall proteins that are neither HRGPs nor glycine-rich proteins.

Journal Article↗
PubMed1980

Action of douglas fir tussock moth larvae and their microflora on dietary terpenes.

A single type of bacterium, tentatively identified as a member of the genus Bacillus, was isolated from 2 of 20 midguts of Douglas fir tussock moth larvae being fed a diet of fir needles. No bacteria could be isolated from most midguts. Although spherically shaped bodies were present in the food bolus, these bodies, if microorganisms, could not be distinguished from spherical bodies associated with the plant tissue. The Douglas fir tussock moth dietary terpenes were altered during their passage through the insects, with two new terpenes being detected in the feces. One of these was identified as isoborneol. The relative significance of the insect and gut microflora with respect to terpene modification is unresolved. The well-established toxicity of terpenes may account for the near absence of common gut microflora in the insects.

Journal Article↗
PubMed1997

Location and Survival of Mycorrhiza Helper Pseudomonas fluorescens during Establishment of Ectomycorrhizal Symbiosis between Laccaria bicolor and Douglas Fir.

The mycorrhiza helper bacterium Pseudomonas fluorescens BBc6, isolated from a Laccaria bicolor sporocarp, consistently promotes L. bicolor-Douglas fir (Pseudotsuga menziesii) ectomycorrhizal formation, even with low doses of bacterial inoculum. In order to describe this phenomenon more accurately, we have looked at the location and survival of the introduced bacterial strain in the soil and in the rhizosphere during the establishment of mycorrhizal symbiosis in glasshouse and nursery experiments. Bacterial populations were quantified with a spontaneous, stable, rifampin-resistant mutant, BBc6R8, which phenotypically conformed to the parental strain. BBc6R8 populations declined rapidly, reaching the detection limit after 19 weeks, and did not increase either when L. bicolor sporocarps were forming in autumn or when Douglas fir roots resumed growing in spring. BBc6R8 was neither an endophyte nor a rhizobacterium. Furthermore, it was not particularly associated with either mycorrhizas of Douglas fir-L. bicolor or L. bicolor sporocarps. Surprisingly, a significant mycorrhiza helper effect was observed when the inoculated BBc6R8 population had dropped as low as 30 CFU g of dry matter(sup-1) in the soil. This study raises questions concerning the bacterial concentration in the soil which is effective for promotion of mycorrhizal establishment and the timing of the bacterial effect. It allows us to develop working hypotheses, which can be tested experimentally, to identify the mechanisms of the mycorrhiza helper effect.

Journal Article↗
PubMed1999

Analysis of nifH gene pool complexity in soil and litter at a Douglas fir forest site in the Oregon cascade mountain range.

Nitrogen-fixing microbial populations in a Douglas fir forest on the western slope of the Oregon Cascade Mountain Range were analyzed. The complexity of the nifH gene pool (nifH is the marker gene which encodes nitrogenase reductase) was assessed by performing nested PCR with bulk DNA extracted from plant litter and soil. The restriction fragment length polymorphisms (RFLPs) of PCR products obtained from litter were reproducibly different than the RFLPs of PCR products obtained from the underlying soil. The characteristic differences were found during the entire sampling period between May and September. RFLP analyses of cloned nifH PCR products also revealed characteristic patterns for each sample type. Among 42 nifH clones obtained from a forest litter library nine different RFLP patterns were found, and among 64 nifH clones obtained from forest soil libraries 13 different patterns were found. Only two of the patterns were found in both the litter and the soil, indicating that there were major differences between the nitrogen-fixing microbial populations. A sequence analysis of clones representing the 20 distinct patterns revealed that 19 of the patterns had a proteobacterial origin. All of the nifH sequences obtained from the Douglas fir forest litter localized in a distinct phylogenetic cluster characterized by the nifH sequences of members of the genera Rhizobium, Sinorhizobium, and Azospirillum. The nifH sequences obtained from soil were found in two additional clusters, one characterized by sequences of members of the genera Bradyrhizobium, Azorhizobium, Herbaspirillum, and Thiobacillus and the other, represented by a single nifH clone, located between the gram-positive bacteria and the cyanobacteria. Our results revealed the distinctness of the nitrogen-fixing microbial populations in litter and soil in a Douglas fir forest; the differences may be related to special requirements for degradation and mineralization processes in the plant litter.

Bacteria↗
PubMed2002

Effects of artificial and western spruce budworm (Lepidoptera: Tortricidae) defoliation on growth and biomass allocation of Douglas-fir seedlings.

Artificial defoliation has been used commonly to simulate defoliation by insect herbivores in experiments, in spite of the fact that obvious differences exist between clipping foliage and natural defoliation due to insect feeding. We used a greenhouse experiment to compare the effects of artificial and western spruce budworm (Choristoneura occidentalis Freeman) defoliation on the growth and biomass allocation of 3-yr old half-sib seedlings from mature Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco variety glauca] trees that showed phenotypic resistance versus susceptibility to budworm defoliation in the forest. Artificial clipping of buds mimicked the effects of budworm feeding on total seedling biomass when 50% of the terminal buds were damaged. However, artificial defoliation decreased seedling height, relative growth rate of height, and shoot: root ratio more than budworm defoliation, whereas budworm defoliation decreased stem diameter relative growth rate more than artificial defoliation. Half-sib seedling progeny from resistant maternal tree phenotypes had greater height, diameter, biomass, and shoot: root ratio than seedlings from susceptible phenotypes. We concluded that careful artificial defoliation could generally simulate effects of budworm defoliation on total biomass of Douglas-fir seedlings, but that the two defoliation types did not have equal effects on biomass allocation between shoot and root. Further, an inherently higher growth rate and a greater allocation of biomass to shoot versus root are associated with resistance of Douglas-fir trees to western spruce budworm defoliation.

Animals↗
PubMed2003

The potential role of ectomycorrhizal fungi in determining Douglas-fir resistance to defoliation by the western spruce budworm (Lepidoptera: Tortricidae).

There is phenotypic variation among individual trees of interior Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) in their resistance to defoliation by the western spruce budworm (Choristoneura occidentalis Freeman). We evaluated the potential role of ectomycorrhizal fungi in determining this resistance using half-sib seedlings derived from parent trees that are resistant versus susceptible to budworm defoliation in the field. The seedlings were inoculated with Laccaria bicolor ectomycorrhizal fungi, fertilized, or untreated. Approximately 48 d after treatment, late-instar larvae from a nondiapausing laboratory colony of C. occidentalis were allowed to feed on pairs of resistant versus susceptible seedlings for 1 wk. Chemical analyses of current-year shoots for nitrogen (N), phosphorus (P), magnesium (Mg), and zinc (Zn) indicated that the fungus increased foliar concentrations of P and Mg in resistant seedlings, but it did not increase their growth rate. However, L. bicolor had no effect on foliar concentrations of P or Mg in susceptible seedlings, even though seedling growth rates increased slightly in response to the inoculation. L. bicolor had no effect on foliar levels of N or Zn in any of the seedlings. As expected, fertilization increased levels of N and P in the foliage of both resistant and susceptible seedlings, but it did not affect levels of Mg and Zn. Surprisingly, the fertilizer treatment had no effect on seedling growth rates. Despite these differences, late-instar budworms showed no feeding preference among untreated, mycorrhizal, or fertilized seedlings. The fact that seedlings from resistant versus susceptible Douglas-firs responded differently to the L. bicolor treatment lends preliminary support to the hypothesis that ecotmycorrhizae might play a role in Douglas-fir resistance to damage from the western spruce budworm. Finally, differences in foliar concentrations of N and P among untreated seedlings from different maternal trees suggested that foliar nutritional chemistry is influenced by the tree's genotype.

Animals↗
PubMed2004

[An overview on studies of soil organic matter in Chinese fir plantation].

Soil organic matter (SOM) is an important component of soil and an important carbon pool of terrestrial ecosystems, which plays an important role in soil nutrient cycling and in the balance of global carbon cycle. This paper discussed the SOM quality in Chinese fir plantation, the influence of rotation on SOM content, the change of SOM during Chinese fir growth, and the effect of human activities such as burning, site preparations and fertilization on SOM. Human activities changed soil environment including soil moisture, temperature, total porosity and nutrient contents, and hence, made the turnover of SOM slower or quicker. The content and quality of SOM in mixed forests were higher than those in pure Chinese fir plantations, and decreased with rotation. In the last part of this paper, some issues to be further researched were put forward, including the turnover model of SOM, its components, and its relationship with global carbon cycle.

Carbon↗
PubMed2005

[Utilization of compressed Chinese fir thinning wood].

With Chinese fir thinnings as raw material, and through measuring the physical-mechanical indices of its compressed wood, observing the variation of its microstructure and using IR analysis, an optimized technique of compressing Chinese fir thinnings was established. The technique was: compression ratio 50%-60%, thickness after compression 20 mm, moisture content before compression 50%, compressing time 20-30 minutes, and hot compressing temperature 180-200 degrees C. CH, an environmentally friendly cooking additive, had positive effects on softening the wood. During compressing, only the cells of fast-growing Chinese fir were extruded, their cavity became smaller, while the cell wall was not destroyed. The thickness reversion ratio of compressed wood was 2.68%, and its size stability and mechanical quality were as good as hardwoods (Betula lumninifera).

Cunninghamia↗
PubMed2006

[Genetic variation and population differentiation in Siberian fir Abies sibirica lebed. Inferred from allozyme markers].

Genetic variation in 24 populations of Siberian fir Abies sibirica Lebed. from the Urals, West Siberia, East Siberia, South Siberia, and the Baikal region were examined using allozyme markers. Three out of fifteen allozyme loci proved to be polymorphic. Heterozygosity He was 6.6-9.6%, which is substantially lower than that in other widely spread boreal conifers. Our results suggest that the Siberian fir populations are subdivided into four geographic groups: (1) the Baikal Lake group, (2) the Sayan and the Altai group, (3) the Middle and Southern Urals group, and (4) Subpolar and Northern Urals group. This pattern of geographic differentiation may be explained by the preservation of the Siberian fir during the last glacial maximum (18 000-22000 years B.P.) in isolated refugia with subsequent recolonization of the present area. FST in the populations examined was 10.16%, which is comparable to the estimate for Larix sibirica (7.9%), a conifer species having a similar range and pattern of geographic population differentiation.

Abies↗
PubMedDate not supplied

Douglas-fir: a third wood-drying condensate found to exhibit in vitro cytotoxicity and genotoxicity.

The present study applies the approach described in Mark et al. for the testing of toxic chemicals produced during the drying of Douglas-fir. The genotoxic potential of Douglas-fir condensate has been previously unexplored and is thus an area of appropriate concern to the forest products industry, regulatory, agencies, and the general public. Previous research conducted in this laboratory has identified two wood-drying condensates that yield positive cytotoxic and genotoxic effects. The results of testing Southern yellow pine and Eastern white pine condensates have been reported elsewhere. Douglas-fir condensate, a third wood-drying condensate, was added in vitro in concentrations ranging from 0.1 to 100 microliters/ml to cultures of Chinese Hamster Ovary (CHO-WBL) cells. A dose response curve was observed with this condensate for both cytotoxicity and genotoxicity. The number of viable cells as well as the mitotic index (MI) and proliferative rate index (PRI) varied inversely with dosage. The result of chromosome aberration (Abs) analysis and sister chromatid exchange (SCE) analysis, both cytogenetic measures of genotoxicity, also gave statistically significant results.

Animals↗
PubMed1999

Fermentability of the hemicellulose-derived sugars from steam-exploded softwood (douglas fir)

Steam explosion ofDouglas fir wood chips under low-severity conditions (log Ro = 3.08 corresponding to 175 degrees C, 7.5 min, and 4.5% SO2) resulted in the recovery of around 87% of the original hemicellulose component in the water-soluble stream. More than 80% of the recovered hemicellulose was in a monomeric form. As the pretreatment severity increased from 3.08 to 3.76, hemicellulose recovery dropped to 43% of the original hemicellulose found in Douglas fir chips while the concentration of glucose originating from cellulose hydrolysis increased along with the concentration of sugar degradation products such as furfural and hydroxymethylfurfural. Despite containing a higher concentration of hexose monomers (mainly glucose originating from cellulose degradation), the water-soluble fraction prepared under high-severity conditions (log Ro = 3.73 corresponding to 215 degrees C, 2.38 min, and 2.38% SO2) was not readily fermented. Only the two hydrolyzates obtained at low and medium (195 degrees C, 4.5 min, and 4.5% SO2) severities were fermented to ethanol using a spent sulfur liquor adapted strain of Saccharomyces cerevisiae. High ethanol yields were obtained for these two hydrolyzates with 0.44 g of ethanol produced per gram of hexose utilized (86% of theoretical). However, the best results of hemicellulose recovery and fermentability were obtained for the low-severity water-soluble fraction which was fermented significantly faster than the fraction obtained after medium-severity treatment probably because it contained higher amounts of fermentation inhibitors. Copyright 1999 John Wiley & Sons, Inc.

Journal Article↗
PubMed2001

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, and phenyl-Sepharose to remove competing phosphohydrolase and isopentenyl diphosphate (IPP) isomerase activities. GPP and FPP synthase formed GPP and E,E-FPP, respectively, as the sole products of the enzymatic condensation of IPP and dimethylallyl diphosphate (DMAPP). The properties of both enzymes are broadly similar to those of other prenyltransferases. The apparent native molecular masses are 54 +/- 3 kDa for GPP synthase and 110 +/- 6 kDa fo

Alkyl and Aryl Transferases↗
PubMed1999

Optically Pumped FIR Laser Lines from CH3OH: New Laser Lines, Frequency Measurements, and Assignments.

We report the identification and characterization of eight new FIR laser lines from methanol (CH3OH) in the range 48.4 to 453.7 µm pumped by sequence and hot bands of a cw CO2 laser. Frequency measurements for most of the new FIR laser lines and from previously reported ones were obtained in the range 0.6-6.8 THz with a one-sigma reproducibility of two parts in 10(7). We propose an assignment of energy levels for two of the new laser lines and for five pumped by 10R(46) previously reported. The high frequency lines with absorption centers outside of the tuning range of the CO2 laser pump showed doublets. These were used to evaluate the offsets of the CO2 absorption transitions.

Journal Article↗
PubMed2002

Parameterizing a model of Douglas fir water flow using a tracheid-level model.

The theory of tree water flow proposed in Aumann & Ford (submitted) is assessed by numerically solving the model developed from this theory under a variety of functional parameterizations. The unknown functions in this nonlinear partial differential equation model are determined using a tracheid-level model of water flow in a block of Douglas fir tracheids. The processes of flow, cavitation, pit aspiration/deaspiration, flow through the cell wall and ray exudation in a block of approximately 79 000 tracheids are modeled. Output from the tracheid model facilitates determination of the hydraulic conductivities in the sapwood as a function of saturation and interfacial area between liquid and gaseous phases of water, the function governing the rate of change in saturation, and the function governing the rate of change in interfacial area. The models show complementary things. The tracheid model shows that capacitance, or the change in saturation per change in pressure, is not constant. When all refilling is stopped, it takes over 180 days for the hydraulic conductivity in the vertical direction to reach 1/4 of its maximal value, showing the robustness of the transpiration stream for conducting water. The shape of the functions determined with the tracheid model change with different tracheid-level assumptions. When these functions are used in the differential equation model, it is shown that cell-wall conductivity plays an important part in the lag in flow observed in many conifers. The flow velocities and rates of change in saturation predicted by the differential equation model agree with those measured in Douglas fir. Both models support the theory of tree water flow presented in Aumann & Ford (submitted) and undermine the theory that water flow in trees is analogous to the flow of current in electric circuits.

Cell Wall↗
PubMed1985

Two-dimensional gel electrophoresis of proteins for genetic studies in Douglas fir (Pseudotsuga menziesii).

A method of two-dimensional gel electrophoresis of proteins from Douglas fir needles is described. Extraction in the presence of sodium dodecyl sulfate (SDS) and 2-mercaptoethanol followed by heating at 100 degrees C produces reliable two-dimensional gels which are convenient for genetic studies. Three genotypes from different geographical origins have been compared: among 225 loci expressed, 22 display regulatory variations and 7 show allelic variations. Thus it is now possible to undertake the genetic study of Douglas fir using this powerful technique.

Genetic Variation↗