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1.
Masaya Ishkawa Akira Kaneko Tsukasa Kashiwa Hiroyasu Watanabe 《Bioscience, biotechnology, and biochemistry》2013,77(12):3187-3191
The relationship of the β-myrcene content with the susceptibility and/or resistance of Pin us species against the pine wood nematode was investigated. For this purpose, the β-myrcene content of the wood of one-year-old shoots was determined. The resistant trees were found to contain a very small amount of β-myrcene. On the other hand, the β-myrcene content of susceptible trees was comparatively high. This relationship was observed in both inter- and intraspecies and also between young and older trees of the same species, i.e., Pinus densiflora or P. thunbergii. The β-myrcene content can feasibly be used as an indicator for screening resistant Japanese red and black pine trees. 相似文献
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Pine wilt disease (PWD) is a devastating disease to pine trees, which was caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus, and causes major losses in coniferous forests in many countries and regions in the world. In order to screen actinomycete strains with high nematicidal activity against PWN, marine actinomycetes were isolated from the marine environment and their nematicidal activity were tested.The marine actinomycetes were isolated from the samples collected from the subtidal zones near Qingdao coast using the dilution and streak plate method and their culture supernatant were assayed in vitro for nematicidal activity against PWN using immersion test. The strain with high nematicidal activity was identified on the basis of morphology, cultural characteristics and 16S rDNA sequence analysis, and its optimal culture conditions for the production of nematicidal substances were investigated through the single-factor experiments.A total of 28 marine actinomycete strains were isolated from the samples. One of these strains, designated as strain HT-8 and isolated from sea sand, exhibited stronger nematicidal activity with a 88.30% corrected mortality of PWN treated with the culture supernatant for 30 h. The strain HT-8 was identified as Streptomyces termitum on the basis of morphology, cultural characteristics, 16S rDNA sequence and phylogenetic analysis. The results of the single factor experiment demonstrated that the optimal cultivation conditions of HT-8 for the production of nematicidal substances were inoculum age was 48 h, inoculum concentration was 6%, concentration of seawater was 100%, initial pH was 7.5 and incubating at 25 ℃ for 7 days.This study provides a theoretical basis for the development of marine microorganism resources and the utilization of natural nematicidal substances. 相似文献
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Recycle,Bury, or Burn Wood Waste Biomass?: LCA Answer Depends on Carbon Accounting,Emissions Controls,Displaced Fuels,and Impact Costs
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Jeffrey Morris 《Journal of Industrial Ecology》2017,21(4):844-856
This study extends existing life cycle assessment (LCA) literature by assessing seven environmental burdens and an overall monetized environmental score for eight recycle, bury, or burn options to manage clean wood wastes generated at construction and demolition activity sites. The study assesses direct environmental impacts along with substitution effects from displacing fossil fuels and managed forest wood sourcing activities. Follow‐on effects on forest carbon stocks, land use, and fuel markets are not assessed. Sensitivity analysis addresses landfill carbon storage and biodegradation rates, atmospheric emissions controls, displaced fuel types, and two alternative carbon accounting methods commonly used for waste management LCAs. Base‐case carbon accounting considers emissions and uptakes of all biogenic and fossil carbon compounds, including biogenic carbon dioxide. Base‐case results show that recycling options (recycling into reconstituted wood products or into wood pulp for papermaking) rank better than all burning or burying options for overall monetized score as well as for climate impacts, except that wood substitution for coal in industrial boilers is slightly better than recycling for the climate. Wood substitution for natural gas boiler fuel has the highest environmental impacts. Sensitivity analysis shows the overall monetized score rankings for recycling options to be robust except for the carbon accounting method, for which all options are highly sensitive. Under one of the alternative methods, wood substitution for coal boiler fuel and landfill options with high methane capture efficiency are the best for the overall score; recycling options are next to the worst. Under the other accounting alternative, wood substitution for coal and waste‐to‐energy are the best, followed by recycling options. 相似文献
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Ground-dwelling invertebrates were sampled by pitfall traps over a 14 week period in parent eucalypt forest and three stages of exotic Pinus radiata plantations established after forest clearance in central Victoria. The four treatments each yielded numerous beetle morphospecies, and the assemblages corresponded only partially with the understorey vegetation. More than 200 beetle morphospecies were captured during this short survey, with 30 found in all four treatments; few morphospecies were abundant (only five with >100 individuals in a total of 3382 beetles). Each treatment had unique morphospecies, but all were rich, with the lowest diversity being 91 morphospecies (young pines). These data confirm that beetle diversity can remain substantial in exotic softwood plantations, but considerable care is needed to interpret this apparent diversity in relation to forest management and the effect of replacement of native forests by exotic taxa. 相似文献
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Foliage of Scots pine (Pinus sylvestris L.) and pedunculate oak (Quercus robur L.) was collected in a mixed pine/oak forest at canopy positions differing in radiation environment. In both species, chlorophyll (Chl) a/b ratios were higher in foliage of canopy positions exposed to higher irradiance as compared to more shaded crown layers. Throughout the growing season, pine needles exhibited significantly lower Chl a/b ratios than oak leaves acclimated to a similar photon availability. Hence, pine needles showed shade-type pigment characteristics relative to foliage of oak. At a given radiation environment, pine needles tended to contain more neoxanthin and lutein per unit of Chl than oak leaves. The differences in pigment composition between foliage of pine and oak can be explained by a higher ratio of outer antennae Chl to core complex Chl in needles of P. sylvestris which enhances the efficiency of photon capture under limiting irradiance. The shade-type pigment composition of pine relative to oak foliage could have been due to a reduced mesophyll internal photon exposure of chloroplasts in needles of Scots pine, resulting from their xeromorphic anatomy. Hence, the higher drought tolerance of pine needles could be achieved at the expense of shade tolerance. 相似文献
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With an increasing demand for forest-based products, there is a growing interest in introducing fast-growing non-native tree species in forest management. Such introductions often have unknown consequences for native forest biodiversity. In this study, we examine epiphytic lichen species richness and species composition on the trunks of non-native Pinus contorta and compare these to the native Pinus sylvestris and Picea abies in managed boreal forests in northern Sweden across a chronosequence of age classes. Overall, we recorded a total of 66,209 lichen occurrences belonging to 57 species in the 96 studied forest stands. We found no difference in species richness of lichens between stands of P. contorta and P. sylvestris, but stands of P. abies had higher total species richness. However, species richness of lichens in stands of P. abies decreased with increasing stand age, while no such age effect was detected for P. contorta and P. sylvestris. Lichen species composition progressively diverged with increasing stand age, and in 30-year-old stands all three tree species showed species-specific assemblages. Epiphytic lichen assemblages in stands of 30-year-old P. contorta were influenced by greater basal area, canopy closure, and average diameter at breast height, P. abies stands by higher branch density and canopy closure, and stands of P. sylvestris by greater bark crevice depth. Differences in lichen species richness and composition were mainly explained by canopy closure and habitat availability, and the greater canopy closure in mature P. abies stands promoted the colonization and growth of calicioid lichen species. Our results indicate that the non-native P. contorta have similar species richness as the native P. sylvestris. The main difference in lichen species richness and composition is between P. abies and Pinus spp. in managed forests of boreal Sweden. 相似文献
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The present research aims to utilize the acrylic Core-Shell Rubber (CSR) particles to reduce the brittleness in Wood Plastic Composites (WPC) prepared from poly(lactic acid) (PLA) and rubber wood sawdust (Hevea brasiliensis). Experimental works consisted of two major parts. The first part concentrated on toughening PLA by using CSR particles. Mechanical tests revealed that PLA had become tougher with a more than five times increment in the impact strength when the CSR was added at only 5 wt%. The modified PLA was less stiff with the significant reductions of both elastic and flexural moduli and strengths. The second part focused on producing WPC from the toughened PLA and rubber wood sawdust. The tensile moduli and the strengths of the PLA composites increased with rubber wood content. The composites turned out to be more brittle with reductions of both the impact strength and the tensile elongation at break at all the sawdust contents. Toughening PLA/wood flour with 5 wt% CSR improved both the impact strength and the tensile elongation at break. The toughness enhancement was also depicted by the plastic deformation observed on the surfaces of fractured PLA/CSR/wood sawdust composites. 相似文献
10.
Christopher Amutabi Kefa Andrew Gregory Anton Espira Mark Lung 《Human ecology: an interdisciplinary journal》2018,46(4):473-484
Successful management of forests, especially in the context of subsistence wood fuel use, can be improved by the application of theoretic models that predict patterns of use. A first step in this approach is understanding the decision rules of people using forests. While optimal foraging theory is normally applied to foraging for food, it also makes sense to apply it in the context of “foraging” for wood fuel. In this study, we applied a time allocation model of optimal foraging theory to wood gathering decisions in communities around Kakamega Forest, a mid-altitude seasonal tropical rain forest. The model predicts that the amount of wood gathered should increase with the distance to the wood source. We found that the predictions of OFT are supported, but only for adults and more strongly on a weekly scale. Based upon the results, we then discuss future improvements of the model to better understand and predict human use. 相似文献
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Reproductive success in the mountain pine beetle, Dendroctonus ponderosae Hopkins, is determined by the production of aggregation and antiaggregation pheromones, as well as body size. In a laboratory experiment with beetles that emerged from naturally attacked hosts, there was no relationship between body size and the production of aggregation pheromones in either sex. In contrast, there were significant relationships between body size and the production of antiaggregation pheromones in males that were paired with females. Pheromone amounts decreased in paired females and antiaggregation pheromones correspondingly increased in paired males, suggesting that after pairing, males take over the role of pheromone production. Although males could potentially select large females by evaluating gallery size, and females could select large males on the basis of their strength in stridulation or physical courtship, we propose that mate choice occurs primarily by olfaction. Small individuals that produce large amounts of pheromone during initial attack could sabotage mate choice based on size-related criteria. This hypothesis is consistent with a lack of evidence for size assortative mating in 92 pairs of beetles. The production of antiaggregants by large male D. ponderosae after pairing with females appears to be an important factor in intraspecific resource partitioning, population regulation, and reproductive success. 相似文献
14.
The objectives of the present work were (a) to quantify the effects of wood ash on forest ecosystems through a meta-analysis
approach associated with a detailed review of the literature (mainly composed of work carried out in Nordic countries) and
(b) to extrapolate the effects on forest growth to other contexts (i.e. warm temperate countries) by identifying the cases
for which wood ash applications can be beneficial to forest production. Three databases were built regarding the effects of
wood ash on soil (151 observations; 33 experimental field trials), on nutrient concentrations of tree foliage (68 observations;
28 trials) and on annual stem biomass growth rate (70 observations; 27 trials). We obtained information on the wide variability
of ash properties due to differences in burnt compounds, combustion processes and ash conditioning. Two important properties
of wood ash are its high pH value and neutralizing capacity. These properties result in biochemical modifications of forest
soils limed with ash. In the short term, soil solution composition was dramatically modified. Intense peaks of the K, Na or
SO4 concentrations were observed, resulting from the dissolution of salts contained in ash. At the same time, Ca and Mg concentrations
increased as the carbonate pool of wood ash started to dissolve. The consequence of this dissolution process was an increase
in the pH in all the soil phases. These modifications increased the activity of the soil microflora and some isolated peaks
in the mineralization of soil organic matter may be observed in mineral soils. In the longer term, that is to say after the
first year following ash application, only the effect on the acidity status of the soil remained significant. The effects
of ash addition on forest ecosystems usually increased with the dose and were more pronounced with loose ash compared to aggregated
ash. The addition of wood ash into forest ecosystems increased the foliar Ca status of trees. Some modifications of other
nutrients, like P or K, were also observed but only for a few years after treatment. For most stands growing on mineral soils
of Nordic countries, this treatment did not result in an increase in tree growth, probably because of the absence of N in
the ash. For stands growing on organic soils of the same area, this input, associated with a long-lasting increase of soil
organic matter mineralization, was sufficient to improve tree growth significantly (median = +59% compared to the control).
For soils located in warm temperate regions, similar responses are expected for organic soils. For mineral soils, the wood
ash application is expected to be suitable for stands showing deficiencies in K, Ca or Mg. Ash may contain high amounts of
toxic heavy metals such as Cd. The bioavailability of most of these elements appeared to be very low in a forest context.
No contamination of food chains has been observed, except possibly via some species of fungi, and heavy metals remain in the
forest litter or in the topsoil. Based on all the reviewed results, several guidelines for wood ash application into forest
ecosystems are proposed. Wood ash application should be restricted to acidic soils. Applications should consist of low doses
of a stabilized ash form. Wood ash should be applied to adult stands rather than onto seedlings. 相似文献
15.
Raphael Trischler Jennifer Roth Matthew T. Sorbara Xenia Schlegel Volker Müller 《Environmental microbiology》2022,24(7):3111-3123
Species of the genus Blautia are typical inhabitants of the human gut and considered as beneficial gut microbes. However, their role in the gut microbiome and their metabolic features are poorly understood. Blautia schinkii was described as an acetogenic bacterium, characterized by a functional Wood–Ljungdahl pathway (WLP) of acetogenesis from H2 + CO2. Here we report that two relatives, Blautia luti and Blautia wexlerae do not grow on H2 + CO2. Inspection of the genome sequence revealed all genes of the WLP except genes encoding a formate dehydrogenase and an electron-bifurcating hydrogenase. Enzyme assays confirmed this prediction. Accordingly, resting cells neither converted H2 + CO2 nor H2 + HCOOH + CO2 to acetate. Carbon monoxide is an intermediate of the WLP and substrate for many acetogens. Blautia luti and B. wexlerae had an active CO dehydrogenase and resting cells performed acetogenesis from HCOOH + CO2 + CO, demonstrating a functional WLP. Bioinformatic analyses revealed that many Blautia strains as well as other gut acetogens lack formate dehydrogenases and hydrogenases. Thus, the use of formate instead of H2 + CO2 as an interspecies hydrogen and electron carrier seems to be more common in the gut microbiome. 相似文献
16.
Ricardo A. Gonzalez-Garcia Timothy McCubbin Mark S. Turner Lars K. Nielsen Esteban Marcellin 《Biotechnology and bioengineering》2020,117(1):167-183
Native to propionibacteria, the Wood–Werkman cycle enables propionate production via succinate decarboxylation. Current limitations in engineering propionibacteria strains have redirected attention toward the heterologous production in model organisms. Here, we report the functional expression of the Wood–Werkman cycle in Escherichia coli to enable propionate and 1-propanol production. The initial proof-of-concept attempt showed that the cycle can be used for production. However, production levels were low (0.17 mM). In silico optimization of the expression system by operon rearrangement and ribosomal-binding site tuning improved performance by fivefold. Adaptive laboratory evolution further improved performance redirecting almost 30% of total carbon through the Wood–Werkman cycle, achieving propionate and propanol titers of 9 and 5 mM, respectively. Rational engineering to reduce the generation of byproducts showed that lactate (∆ldhA) and formate (∆pflB) knockout strains exhibit an improved propionate and 1-propanol production, while the ethanol (∆adhE) knockout strain only showed improved propionate production. 相似文献
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《化学与生物多样性》2018,15(1)
Pinus armandii is suspicious to be responsible for the Pine Nut Syndrome, a long lasting bitter and metallic taste after the consumption of pine nuts. To find chemical characteristic features for the differentiation of P. armandii from other Pinus species, 41 seed samples of the genus Pinus from 22 plant species were investigated regarding the content and the composition of fatty acids, tocopherols, and amino acids. The predominant fatty acids in the seed oils were linoleic acid (35.2 – 58.2 g/100 g), oleic acid (14.6 – 48.5 g/100 g), and pinolenic acid (0.2 – 22.4 g/100 g), while the vitamin‐E‐active compounds were dominated by γ‐tocopherol. The amino acid composition was mainly characterized by arginine and glutamic acid with amounts between 0.9 and 8.9 g/100 g as well as 2.1 g/100 g and 8.3 g/100 mg. On the basis of this investigation, a Principle Component Analysis has been used to identify the most important components for the differentiation of P. armandii from other Pinus species. Using the data for glutamic acid, 20:2Δ5,11, 18:3Δ5,9,12, 18:1Δ9, and oil content, a classification of the 41 samples into four different groups by cluster analysis was possible, but the characteristic features of P. armandii were too close to some other members of the genus Pinus, making a clear differentiation of this species difficult. Nevertheless, the investigation showed the similarities of different members of the genus Pinus with regard to fatty acids, vitamin‐E‐active compounds, and amino acids. 相似文献
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Background
Aside from the ecological impacts, invasive species fascinate ecologists because of the unique opportunities that invasives offer in the study of community ecology. Some hypotheses have been proposed to illustrate the mechanisms that allow exotics to become invasive. However, positive interactions between exotic and native insects are rarely utilized to explain invasiveness of pests.Methodology/Principal Findings
Here, we present information on a recently formed association between a native and an exotic bark beetle on their shared host, Pinus tabuliformis, in China. In field examinations, we found that 35–40% of P. tabuliformis attacked by an exotic bark beetle, Dendroctonus valens, were also attacked by a native pine bark beetle, Hylastes parallelus. In the laboratory, we found that the antennal and walking responses of H. parallelus to host- and beetle-produced compounds were similar to those of the exotic D. valens in China. In addition, D. valens was attracted to volatiles produced by the native H. parallelus.Conclusions/Significance
We report, for the first time, facilitation between an exotic and a native bark beetle seems to involve overlap in the use of host attractants and pheromones, which is cross-attraction. The concept of this interspecific facilitation could be explored as a novel invasive mechanism which helps explain invasiveness of not only exotic bark beetles but also other introduced pests in principle. The results reported here also have particularly important implications for risk assessments and management strategies for invasive species. 相似文献20.
Two Pine Endo-β-1,4-Glucanases Are Associated with Rapidly
Growing Reproductive Structures
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Carol A. Loopstra Aidyn Mouradov Adam Vivian-Smith Tina V. Glassick Beth V. Gale Simon G. Southerton Heidi Marshall Robert D. Teasdale 《Plant physiology》1998,116(3):959-967
Two cDNA clones encoding
endo-β-1,4-glucanases (EGases) were isolated from a radiata pine
(Pinus radiata) cDNA library prepared from immature
female strobili. The cDNAs PrCel1 (Pinus
radiata cellulase 1) and PrCel2 encode
proteins 509 and 515 amino acids in length, respectively, including
putative signal peptides. Both proteins contain domains conserved in
plant and bacterial EGases. The proteins PRCEL1 and PRCEL2 showed
strong similarity to each other (76% amino acid identity), and higher
similarity to TPP18 (73 and 67%, respectively), an EGase cloned from
tomato (Lycopersicon esculentum) pistils, than to any
other reported EGases. Northern-blot analyses indicated that both genes
displayed a similar pattern of expression. The only significant
difference was in the level of expression. In situ
hybridizations were used to demonstrate that, within
differentiating pine reproductive structures, PrCel1 expression was
greatest in microsporangia in pollen strobili and near the developing
ovule in the seed strobili. Expression was also found in vegetative
tissues, especially in regions experiencing cell elongation, such as
the elongating region of root tips. Both proteins have an ability to
degrade carboxymethylcellulose in vitro. Genomic-blot analysis
indicated the presence of a family of EGase genes in the radiata pine
genome, and that PrCel1 and PrCel2 are transcribed from
distinct one-copy genes.The growth and development of floral organs involves many
physiological processes, including modifications to the cell wall.
EGases (cellulases) may play roles in cell wall loosening, which is
required for expansion or major cell wall disruption. Cell expansion
has been reviewed by Cosgrove (1993), who demonstrated that
acid-induced extension of cell walls appears to require the activity of
expansins. Wall-modifying enzymes such as endoxyloglucan transferase,
and wall-degrading enzymes such as glucanases, are also likely to be
involved, but there is no evidence that they can cause extension of
isolated walls. Major cell wall disruption also occurs at several steps
in the development of flower reproductive organs (del Campillo and
Lewis, 1992). The callose wall that protects the meiotic cells is
broken down during early pollen differentiation, releasing the
microspores into the anther locule. Later, the tapetum begins to break
down and the cytoplasm is released into the locule. Finally, the
release of the mature pollen grains from the anthers is facilitated by
the formation of a fissure, the stomium. Similarly, during
pollen-stigma interactions, cell wall loosening of the papillary cells
at the surface of the stigma has been reported. EGases have been shown
to accumulate in anthers of beans and sweet peas in a developmentally
regulated manner and may be involved in the cell wall disruption
required for pollen differentiation.Plant EGases typically lack the ability to degrade microcrystalline
cellulose in vitro. Bacterial EGases, however, are able to degrade
cellulose. Therefore, all EGases are sometimes referred to as
cellulases. Genes encoding EGases have been isolated from many
different plant species, including tomato (Lycopersicon
esculentum) (Lashbrook et al., 1994; Milligan and Gasser, 1995),
elder (Sambucus nigra) (Taylor et al., 1994), pea
(Pisum sativum) (Wu et al., 1996), soybean (Glycine
max) (Kemmerer and Tucker, 1994), Arabidopsis (Ferl, 1995), poplar
(Populus alba) (Nakamura et al., 1995), kidney bean
(Phaeseolus vulgaris) (Tucker and Milligan, 1991), and
avocado (Persea americana) (Tucker et al., 1987). Some of
these enzymes, including TomCel2 (Lashbrook et al., 1994), EGL1 (Wu et
al., 1996), and AvoCel1 (Tucker et al., 1987), are
primarily associated with fruit ripening. Another group, including BAC
(Tucker and Milligan, 1991), SAC1 (Kemmerer and Tucker, 1994), TomCel1
(Lashbrook et al., 1994), and JET1 (Taylor et al., 1994), are
associated with abscission. Yet another group of enzymes appears to be
expressed predominantly in rapidly expanding tissues. Expression of
TPP18 (Milligan and Gasser, 1995), which is identical to Cel4 (Brummell
et al., 1997), occurs in growing pistils of tomato flowers, and to a
lesser extent in stamens, but not in fully expanded flower parts.
Expression is also high in the growing zones of etiolated hypocotyls
and in expanding leaves. Here we report on the expression of two EGases
cloned from reproductive structures of radiata (Monterey) pine
(Pinus radiata).As in angiosperms, the “flowering” of radiata pine starts with the
transition of an undetermined axillary apex into a determinant
reproductive apex, which develops into the strobili (cones).
Reproductive buds are simple because they normally contain a single
strobilus and no leaves. Mature male (pollen) cones are small (1–2 cm
in length) and are made up of spirally arranged microsporophylls, each
bearing two microsporangia (pollen sacs). The microspores develop into
four-celled pollen grains. Female (seed) cones consist of an axis,
which bears a specially arranged series of small appendages termed
bracts. In the axil of each bract is a thick scale upon which two
ovules are borne, attached to the adaxial surface of the cone scale
near the base. Because the ovuliferous scales are lateral structures
subtended by a bract, the entire cone is a “compound” strobilus,
and may be compared in this respect with an inflorescence. Such female
axes generally are located at the top of the adult tree, whereas male
cones are located farther down the stem and contain only
microsporophylls.A few genes have previously been cloned from various parts or stages of
developing radiata pine cones, including the cDNAs encoding
genes preferentially expressed in immature female and male cone buds.
Homologs of the angiosperm late-flowering, meristem-identity, and
organ-identity genes regulate development of unisexual cones in the
conifer radiata pine (Mouradov et al., 1996, 1997a, 1997b). MADS box
genes have also been cloned from another conifer, Norway spruce
(Picea abies) (Tandre et al., 1995). Two different cDNAs
with homology to legumins have been isolated from fertilized ovules of
white pine (Pinus strobus), but are not expressed in
unfertilized ovules (Baker et al., 1996). Several cDNA clones encoding
seed-storage proteins have also been isolated from Douglas fir and
interior spruce megagametophytes (Newton et al., 1992; Leal and Misra,
1993). Mature megagametophytes have been used for many years to study
isozyme variation, and are commonly used as sources of DNA for genome
mapping because of their haploid condition.To gain a greater understanding of the genes involved in the formation
of pine reproductive structures, we constructed a cDNA library from
immature female cones and differentially screened against vegetative
buds. Here we report on the cloning, sequencing, and characterization
of two of those genes, PrCel1 and PrCel2, that have very high homology
to each other and to previously cloned EGases. 相似文献