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PubMed2002

Severe leaching of calcium ions from fir needles caused by acid fog.

We have measured the components of the throughfall under fir trees (Abies firma) in the field around Mt. Oyama, where the forest appears to be declining, for the period 1994-1998. Exposure experiments of a simulated acid fog to fir twigs were performed under field conditions. There was a similarity between the acid response in the field and that in the laboratory. In both studies, the severe leaching of calcium ions from the needle surface was caused by exposure to acid fog. We also applied acid fog to fir seedlings over 1 year and observed a decrease in the growth of the seedlings due to this application in the dormant season. These results suggest that the severe leaching of calcium ions due to acid fog may cause the deficiency of calcium and be responsible for the decline of the fir trees.

Acid Rain↗

PubMed1998

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 sesquiterpenes found in the oleoresin and that, in response to wounding, only two new products were synthesized, delta-cadinene and (E)-alpha-bisabolene. A similarity based cloning strategy yielded two new cDNA species from a stem cDNA library that, when expressed in Escherichia coli and the gene products subsequently assayed, yielded a remarkable number of sesquiterpene products. The encoded enzymes have been named delta-selinene synthase and gamma-humulene synthase based on the principal products formed; however, each enzyme synthesizes three major products and produces 34 and 52 total sesquiterpenes, respectively, thereby accounting for many of the sesquiterpenes of the oleoresin. The deduced amino acid sequence of the delta-selinene synthase cDNA open reading frame encodes a protein of 581 residues (at 67.6 kDa), whereas that of the gamma-humulene synthase cDNA encodes a protein of 593 residues (at 67.9 kDa). The two amino acid sequences are 83% similar and 65% identical to each other and range in similarity from 65 to 67% and in identity from 43 to 46% when compared with the known sequences of monoterpene and diterpene synthases from grand fir. Although the two sesquiterpene synthases from this gymnosperm do not very closely resemble terpene synthases from angiosperm species (52-56% similarity and 26-30% identity, there are clustered regions of significant apparent homology between the enzymes of these two plant classes. The multi-step, multi-product reactions catalyzed by the sesquiterpene synthases from grand fir are among the most complex of any terpenoid cyclase thus far described.

Alkyl and Aryl Transferases↗

PubMed1993

Neutralization and buffering capacity of leaves of sugar maple, largetooth aspen, paper birch and balsam fir.

We compared the acidity, the external acid neutralizing capacity and the buffering capacity of leaves of four commercially important tree species, largetooth aspen (Populus grandidentata Michx.), sugar maple (Acer saccharum Marsh.), paper birch (Betula papyrifera Marsh.) and balsam fir (Abies balsamea (L.) Mill), at two sites of contrasting soil fertility in southern Quebec. External acid neutralizing capacity (ENC) of leaves was determined by measuring the change in pH induced by soaking fresh leaves in an acidic solution (pH 4.0) for two hours. The ENC was highest for largetooth aspen (14.3 micro equiv H(+) g(-1)), and lowest for sugar maple and balsam fir (< 5 micro equiv H(+) g(-1)). The buffering capacity index (BCI) was determined by measuring the amount of acid necessary to produce a change of 5 micro equiv H(+) in the leaf homogenate. The BCI ranged from 883 micro equiv H(+) g(-1) for largetooth aspen to less than 105 micro equiv H(+) g(-1) for sugar maple and balsam fir. Leaves of sugar maple and balsam fir had a lower internal pH and a higher percentage of ENC over BCI than paper birch and largetooth aspen. Overall, ENC was correlated with the concentration of all leaf nutrients except Ca, and BCI was correlated with Mg, N and Ca. The site effect was relatively unimportant for all variables.

Journal Article↗

PubMed2006

Aminocyclopropane carboxylic acid synthase is a regulated step in ethylene-dependent induced conifer defense. Full-length cDNA cloning of a multigene family, differential constitutive, and wound- and insect-induced expression, and cellular and subcellular localization in spruce and Douglas fir.

In conifer stems, formation of chemical defenses against insects or pathogens involves specialized anatomical structures of the phloem and xylem. Oleoresin terpenoids are formed in resin duct epithelial cells and phenolics accumulate in polyphenolic parenchyma cells. Ethylene signaling has been implicated in the induction of these chemical defenses. Recently, we reported the cloning of 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) from spruce (Picea spp.) and Douglas fir (Pseudotsuga menziesii). ACO protein was constitutively expressed in Douglas fir and only weakly induced upon wounding. We now cloned seven full-length and one near full-length cDNA representing four distinct 1-aminocyclopropane-1-carboxylic acid synthases (ACS; ACS1, ACS2, ACS3, and ACS4) from spruce and Douglas fir. Cloning of ACS has not previously been reported for any gymnosperm. Using gene-specific, quantitative real-time polymerase chain reaction, we measured constitutive expression for the four ACS genes and the single-copy ACO gene in various tissues of Sitka spruce (Picea sitchensis) and in white spruce (Picea glauca) somatic embryos. ACO and ACS4 were ubiquitously expressed at high levels; ACS1 was predominantly expressed in developing embryos and ACS2 and ACS3 were expressed only at very low levels. Insect attack or mechanical wounding caused strong induction of ACS2 and ACS3 in Sitka spruce bark, a moderate increase in ACO transcripts, but had no effect on ACS1 and ACS4. ACS protein was also strongly induced following mechanical wounding in Douglas fir and was highly abundant in resin duct epithelial cells and polyphenolic parenchyma cells. These results suggest that ACS, but not ACO, is a regulated step in ethylene-induced conifer defense.

Amino Acid Oxidoreductases↗

PubMed2006

An unbiased FIR filter for TIE model of a local clock in applications to GPS-based timekeeping.

An unbiased finite impulse response (FIR) filter is proposed to estimate the time-interval error (TIE) K-degree polynomial model of a local clock in global positioning system (GPS)-based timekeeping in the presence of noise that is not obligatory Gaussian. Generic coefficients for the unbiased FIRs are derived. The low-degree FIRs and noise power gains are given. An estimation algorithm is proposed and examined for the TIE measurements of a crystal clock in the presence of the uniformly distributed sawtooth noise induced by the multichannel GPS timing receiver. Based upon this algorithm, we show that the unbiased FIR estimates are consistent with the reference (rubidium) measurements and fit them better than the standard Kalman filter.

Journal Article↗

PubMed2003

Variation in budburst phenology of Douglas-fir related to western spruce budworm (Lepidoptera: Tortricidae) fitness.

Variation in budburst phenology among individual trees of interior Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) may influence their susceptibility to western spruce budworm (Choristoneura occidentalis Freeman) defoliation. We tested the hypothesis that phenological asynchrony between Douglas-fir and the western spruce budworm is a mechanism of resistance using clones derived from parent trees that showed resistance versus susceptibility to C. occidentalis defoliation in the field. Susceptible clones had earlier budburst phenology compared with resistant clones when they were grown in a common greenhouse environment, demonstrating a genetic basis for parallel phenological differences exhibited by the parent trees. We tested the importance of phenological asynchrony as a factor influencing fitness of C. occidentalis using two different greenhouse bioassay experiments. One experiment compared western spruce budworm performance on equivalent phenological stages of susceptible and resistant clones by matching larval feeding to the columnar (fourth) bud development stage of each clone. Larvae reared on resistant clones had greater realized fitness (i.e., number of F1 offspring produced) than those reared on susceptible clones when the influence of variation in budburst phenology was minimized. In the other experiment, western spruce budworm larvae were placed on all trees on the same date when approximately 50% of all terminal buds in the population were in the yellow (second) budburst stage. Larvae reared on susceptible clones had greater realized fitness than those reared on resistant clones when the influence of phenological asynchrony was expressed. Our results suggest that resistant phenotypes of Douglas-fir have negative effects on survival and reproduction of C. occidentalis under the natural conditions that insects and trees experience in the field. Genetic variation among trees in budburst phenology has an important influence on interactions between the western spruce budworm and Douglas-fir.

Animals↗

PubMed2000

[A comparative study on nutrient accumulation and distribution of different generations of Chinese fir plantations].

The nutrient accumulations and distribution of different generation of Chinese fir plantations in central production areas of China were studied through the investigation of plantation with different generation(first, second and third), ages (5, 10, 15, 20 years old) and sites(site index 14, 16 and 18). The nutrient accumulations and distribution of Chinese fir plantations were greatly influenced by the number of planting generation. Nutrient accumulation and utilization efficiency in tree layer of Chinese fir plantations declined with the increasing planting generation number, with the first generation > the second > the third; while the nutrient accumulation of understory vegetation was increased with the increasing of planting generation number. Compared with the first generation plantations, nutrient accumulation of tree layer of the second and the third generations decreased by 17.56% and 36.24% respectively, and the third generation platation decreased by 22.65% than the second generation. Meanwhile, successive planting resulted in a decreasing nutrient utilization efficiency of Chinese fir plantation, and an increasing nutrient necessary for dry matter production per unit, which is disadvantageous to the maintaining of soil fertility, but beneficial to the nutrient accumulation of understory vegetation.

Abies↗

PubMed2002

[Effects of plant foliar litter diversity on the growth of Chinese fir seedling and the absorption of (15NH4)2SO4].

Effects of plant foliar litter species composition on the growth of the potted Chinese fir seedling and the absorption of (15NH4)2SO4 was studied. The result showed that there were significant growth responses to foliar litter treatments. A very noticeable trend was that as the tree species of foliar litter placed on pots increases, the growth of Chinese fir seedlings increases steadily. Seedling growth in four-species mixed foliar litter were the largest and that in Cunninghamia lanceolata + Michelia macclurei + Kalooanax septemlobus foliar litter mixture were the second. The others were in order of seedlings in C. lanceolata + M. macclurei + Castanopsis carlesii foliar litter mixture > C. lanceolata + K. septemlobus foliar litter mixture > C. lanceolata + C. carlesii > control (no foliar litter) > C. lanceolata + M. macclurei foliar litter mixture > Chinese fir foliar litter treatment. The recovery of (15NH4)2SO4 by Chinese fir seedlings in no foliar litter treatment was maximum, and seedlings grown in four foliar litter mixture was the second, then it was in order of C. lanceolata + C. carlesii + K. septemlobus = C. lanceolata + C. carlesii + M. macclurei > C. lanceolata + K. septemlobus > C. lanceolata + C. carlesii > C. lanceolata + M. macclurei > C. lanceolata foliar litter treatment. In addition, the residue of (15NH4)2SO4 was greater in soil with foliar litter treatment than in no foliar litter soil. Both of the residual amount of (15NH4)2SO4 in soil and the total recovery of (15NH4)2SO4 increased with the increasing tree species of applied foliar litter.

Absorption↗

PubMed2004

[Constructing genetic linkage maps in Chinese Fir using F1 progeny].

A new strategy was proposed for constructing linkage maps for 1:1 segregation molecular markers in Chinese fir. Linkage phase and recombination ratio for any two loci can be inferred and estimated. For the best order in a linkage group, the Hidden Markov Chain Model was used for multilocus linkage analysis. The mapping method proposed here was more effective than the 'pseudo-testcross' method commonly used in forest trees. In this paper,with the AFLP marker data obtained from the F1 progeny of 'Jurong 0' (female) x 'Rouye' (male), the genetic linkage maps of the Chinese fir clones, 'Jurong' and 'Rouye', were reconstructed based on the new mapping method. In the genetic linkage map of "Jurong 0", 101 markers were distributed in 11 linkage groups with an average distance of 22.6 cM and a total length of 2 282.6 cM. There were as many as 17 markers and as few as 5 markers in single linkage groups of the map. In the genetic linkage map of 'Rouye', 94 markers were distributed in the 11 linkage groups with an average distance of 27.3 cM and a total length of 2 565.8 cM. There were as many as 16 markers and as few as 4 markers in single linkage groups of the map. Compared with the 'pseudo- testcross' method, the two maps increased 26 markers and 28 markers, respectively, and totally 54 markers were added. The two maps contained 195 AFLP markers and each spanned more than 2 000 cM, almost covering the whole genome of Chinese fir. Therefore, the resolutions of linkage maps of Chinese fir 'Jurong 0' and 'Rouye' were improved with the new mapping method, and the maps provide the framework for further genetic analysis.

Chromosome Mapping↗

PubMed2005

[Alleviation effect of exogenous Ca, P and N on the growth of Chinese fir seedlings under Al stress].

In this study, three month-old seedlings of Chinese fir (Cunninghamia laceolata) were grown in solution culture with 1 mmol x L(-1) Al at pH 4.0 for 80 days to evaluate the effects of varying concentrations of Ca, P, and NH4+-N or NO3(-)-N in solution on their growth. The morphological indexes (fresh weight, dry weight, shoot length, root length and relative elongation ratio) and physiological indexes (MDA content and POD activity) were submitted to statistical analysis and compared. The results indicated that the seedlings weight or shoot length had a significantly positive correlation with the molar ratio of solution Ca/Al. The MDA content and POD activity decreased with the increasing molar ratio of Ca/Al, and Ca/Al > or = 2.8 was the critical ratio. Similar to Ca/Al, high P/Al molar ratio also had an obvious effect on the growth of Chinese fir seedlings under Al stress, and P/Al > or = 4.5 was the critical ratio. The growth of Chinese fir seedlings was improved by increased NH4+-N supply, but the effect was less obvious than Ca and P. Solution NH4+-N/Al > or = 4.7 was the critical molar ratio. Solution NO3(-)-N could mitigate some adverse effects of Al on Chinese fir seedlings growth, but no regular effects were found with the change of solution NO3(-)-N/Al molar ratio.

Aluminum↗

PubMed2025

Time-course transcriptome and proteomic dynamics during the de novo shoot organogenesis in Chinese fir (Cunninghamia lanceolata).

De novo shoot organogenesis (DNSO) enables plants to regenerate shoots from various explants, offering valuable opportunities for research and plant biotechnology applications. While significant progress has been made in understanding regeneration in angiosperms, the regulatory mechanisms in gymnosperms, particularly Chinese fir (Cunninghamia lanceolata), remain poorly understood, despite its importance as a key timber species in China. This study successfully established an efficient DNSO protocol for Chinese fir, identifying six distinct stages in the process through cellular-level analysis. Time-course transcriptome and proteomics analyses revealed dynamic changes in mRNA and protein levels during regeneration. Notably, proteins showed more significant alterations across a broad range of biological processes, often independent of corresponding mRNA changes. Key pathways associated with ethylene metabolism and abiotic stress responses were enriched, highlighting their critical roles in regeneration. Further experiments confirmed that moderate osmotic stress treatments (150 mm mannitol) and ethylene treatment (100 μm ACC and 5 μm AgNO3) substantially enhanced DNSO efficiency. In summary, this study uncovers the molecular mechanisms underlying Chinese fir DNSO, providing valuable insights into improving plant regeneration efficiency in this economically important species. These findings contribute to advancements in plant biotechnology and sustainable forestry practices.

Cunninghamia↗

PubMed1993

Molecular cloning and characterization of a legumin-like storage protein cDNA of Douglas fir seeds.

A cDNA library was made from poly(A)+ RNA isolated from developing Douglas fir (Pseudotsuga menziesii) embryo and megagametophytic tissue, and the cDNA clones were identified by immunoscreening with polyclonal antiserum against the crystalloid storage protein complex of Douglas fir. The nucleotide sequence of the longest cDNA insert (DF1) was analysed. The amino acid sequence derived from the DNA sequence verified its identity as a legumin-like storage protein (pseudotsugin) and confirmed that the protein is synthesized as a precursor similar to the 11-12S storage globulins. The transcripts corresponding to cDNA insert DF1 were abundant in the early- to mid-stages of embryogenesis in the diploid embryonic axes as well as in the haploid megagametophytic tissue. The deduced amino acid sequence of pseudotsugin consists of a 29 amino acid N-terminal signal peptide preceding the acidic polypeptide region (286 amino acids) and the subsequent basic polypeptide region (212 amino acids). The site for post-transcriptional cleavage of the precursor polypeptide to make the A and B polypeptides is localized between asparagine -315 and glycine -316 and is highly conserved between angiosperms and gymnosperms. The deduced amino acid sequence for the DF1 cDNA clone reveals that pseudotsugin is rich in arginine, glutamic acid and serine and is low in cysteine, methionine and lysine. Comparison of the deduced amino acid sequence of Douglas fir pseudotsugin shows between 29-38.5% identity with angiosperm species, 63% identity with interior spruce, and 60% identity with eastern white pine.

Amino Acid Sequence↗

PubMed1996

Post-termination-induced and hormonally dependent expression of low-molecular-weight heat shock protein genes in Douglas fir.

We have isolated and sequenced two cDNA clones (PM 18.2A; PM 18.2B) from Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) which encode for the low-molecular-weight heat shock proteins (LMW HSPs) of 18.2 kDa. The predicted amino acid sequences of the two Douglas fir proteins are 97.5% identical. A phylogenetic tree of class I LMW HSPs showed that the PM LMW HSPs are found within a subgroup consisting exclusively of dicot species indicating that class I LMW HSPs evolved from a common ancestor predating the divergence of gymnosperms and angiosperms. Northern blots of RNA from dry, imbibed, stratified and germinated seeds revealed a notable induction of LMW HSP transcripts during post-germination and early seedling growth. Unlike previous reports, the expression of these HSPs appears to be primarily restricted to seedlings as mRNA transcripts were detected at very low levels during seed development and desiccation. Maximum induction of LMW HSPs in seedlings occurred during heat shock treatment at 38-40 degrees C, whereas cold shock or wounding failed to induce HSP transcripts. The transcription of HSP genes is up regulated by GA, MeJA and auxin and is down regulated by ABA. Methyl jasmonate treatment induced expression of these genes in dormant seeds of Douglas fir. The expression of class I cytoplasmic LMW HSPs in seedlings and their regulation by plant growth regulators suggests specific roles in plant development other than desiccation tolerance.

Amino Acid Sequence↗

PubMed1989

Dispersed repetitive sequences in the chloroplast genome of Douglas-fir.

Restriction mapping and DNA sequencing were used to characterize dispersed repetitive DNA in the chloroplast genome of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco]. To map repeat families, chloroplast DNA (cpDNA) clones were hybridized at high stringency to one another and to cpDNA cut with restriction enzymes. Repeats are clustered in four regions of the genome and comprise at least six families. Sequence analysis of one repeat family shared among three XbaI fragments indicated the presence of a 633 bp inverted repeat which contains a complete tRNA-Serine (GCU) gene and a highly conserved open reading frame (ORF 3.6). Both ends of this 633 bp dispersed repeat have a transposon-like combination of short direct and inverted repeats. One copy of the repeat flanks one of the endpoints of a major inversion which differentiates Douglas-fir from tobacco cpDNA. Dispersion of repetitive DNA by transposition, coupled with loss of the large inverted repeat, appears to have predisposed conifer cpDNA to a number of inversions. An 8 bp (CATCTTTT) direct repeat in tobacco is located between two inverted sections in Douglas-fir; it may be a target sequence for homologous recombination.

Base Sequence↗

PubMed2003

Highly variable SSR markers in Douglas-fir: Mendelian inheritance and map locations.

Twenty-two highly variable SSR markers were developed in Douglas-fir [ Pseudotsuga menziesii (Mirb.) Franco] from five SSR-enriched genomic libraries. Fifteen PCR primer pairs amplified a single codominant locus, while seven primer pairs occasionally amplified two loci. The Mendelian inheritance of all 22 SSRs was confirmed via segregation analyses in several Douglas-fir families. The mean observed heterozygosity and the mean number of alleles per locus were 0.855 (SE=0.020) and 23 (SE=1.6), respectively. Twenty markers were used in genetic linkage analysis and mapped to ten known linkage groups. Because of their high polymorphism and unambiguous phenotypes, 15 single-locus markers were selected as the most suitable for DNA fingerprinting and parentage analysis. Only three SSRs were sufficient to achieve an average probability of exclusion from paternity of 0.998 in a Douglas-fir seed orchard block consisting of 59 parents.

Base Sequence↗

PubMed2002

The Douglas-fir BiP promoter is functional in Arabidopsis and responds to wounding.

A DNA sequence representing the promoter region of the Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) luminal binding protein PmBiP (PmBiPPro1) was isolated using inverse polymerase chain reaction (iPCR). Transient expression analysis of PmBiPPro1 fused to the beta-glucuronidase (GUS) reporter gene demonstrated that this promoter is functional in germinating Douglas-fir embryos. Transgenic Arabidopsis plants containing PmBiPPro1:GUS reporter gene constructs revealed strong staining associated with actively dividing/expanding cells and secretory tissues in developing seedlings. Wounding of cotyledons resulted in an increase in local staining associated with cells surrounding the wound site. Deletion analysis showed that elements necessary for basal-level expression reside within a -261 to +16 bp region, although upstream elements are necessary for higher-level expression in germinating Douglas-fir embryos, developing Arabidopsis seedlings and wounded cotyledons. Correlation of the observed expression pattern with the known function of BiP suggests that pathways controlling expression are highly conserved between angiosperms and gymnosperms.

Arabidopsis↗

PubMed1992

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- and beta-pinene. This pinene cyclase was purified, and polyclonal antibodies were generated in rabbits against the sodium dodecyl sulfate-denatured protein. The antibody preparation was found to cross-react by Western blotting with other grand fir monoterpene cyclases that produce different olefinic products, but not with monoterpene cyclases from related conifer species (Pinus contorta and P. ponderosa) or from angiosperms (Mentha piperita and M. spicata). The increase in monoterpene cyclase activity after wounding was closely correlated with the appearance of new cyclase protein as determined by immunoblotting. These results indicate that the wound-dependent increase in monoterpene cyclase activity is a consequence of de novo synthesis of cyclase protein.

Antibodies↗

PubMed1988

Air pollution and the decline of the fir forest in Parnis National Park, near Athens, Greece.

The Greek fir Abies cephalonica Loud. dominates the higher elevations of Mount Parnis, located 30 km north of Athens. The fir forest is showing signs of stress and dieback commonly attributed to past mismanagement, periodic drought, and to disease. Tree cores, lichens, and needle samples were collected from a southeast site facing Athens and from a north-facing site. Fir trees from the southeast site exhibited growth reduction since the early sixties. Trees from the north site did not show growth reduction but they showed growth deceleration since 1970. Lichen samples from the southeast site had significantly higher levels of Pb, Zn, Cd, Cu, Al, Mo, Mn and N than samples from the north site. We suggest that air pollution could be contributing to the decline of the forest.

Journal Article↗