Showing papers on "Bark published in 1992"
TL;DR: Seasonal patterns of proteins and of cold hardiness were characterized in bark and xylem tissues of genetically related (sibling) deciduous and evergreen peach (Prunus persica [L.] Batsch).
Abstract: Seasonal patterns of proteins and of cold hardiness were characterized in bark and xylem tissues of genetically related (sibling) deciduous and evergreen peach (Prunus persica [L.] Batsch). In contrast with deciduous trees, which entered endodormancy and abscised leaves in the fall, evergreen trees retained their leaves and exhibited shoot elongation under favorable environmental conditions. A successive increase in the cold hardiness of bark and xylem was observed during the fall in both genotypes. This was followed by a subsequent decrease from midwinter to spring. Xylem tissue in both genotypes exhibited deep supercooling and a significant correlation (r = 0.99) between the midpoint of the low-temperature exotherm and the subzero temperature at which 50% injury occurred (assessed by electrolyte leakage) was noted. The maximum hardiness level attained in deciduous trees was more than twofold that of evergreens. Seasonal pattern of proteins from bark and xylem of the sibling genotypes was characterized by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Among other qualitative and quantitative changes, accumulation of a 19-kilodalton polypeptide in the bark of both genotypes was observed during fall followed by a decrease in spring. This polypeptide accumulated to higher levels in the deciduous peach compared with the evergreen. Additionally, a 16-kilodalton protein exhibited the same pattern in deciduous trees but not in the evergreen trees. Both the 19- and a 16-kilodalton bark proteins conform to the criteria of a bark storage protein. The relationship of seasonal changes in protein to cold hardiness and dormancy in these genetically related peach genotypes is discussed.
225 citations
TL;DR: DNA gel blot analysis suggests that poplar bark storage protein is encoded by a multigene family of about five genes, which will provide a useful system for investigating photoperiodism in woody plants.
Abstract: Bark storage proteins accumulate in the bark of many woody plants during autumn and winter. In poplar (Populus deltoides Bartr. ex Marsh), the accumulation of the 32-kilodalton bark storage protein is controlled by photoperiod. We have isolated a full-length cDNA encoding for the poplar 32-kilodalton bark storage protein and determined its nucleotide sequence. The derived amino acid sequence shows that poplar bark storage protein is rich in serine, leucine, phenylalanine, and lysine. Poplar bark storage protein is similar to the poplar wound-induced cDNA clone 4 and clone 16 (TJ Parsons, HD Bradshaw, MP Gordon [1989] Proc Natl Acad Sci USA 86: 7895-7899). DNA gel blot analysis suggests that poplar bark storage protein is encoded by a multigene family of about five genes. Poplar plants grown in long days contained low levels of mRNA for the bark storage protein. Exposure to short days resulted in an increase in bark storage protein mRNA within 7 days. After 21 days of short day exposure, high levels of mRNA were detected. The accumulation of bark storage protein mRNA in response to short days was also observed in plants exposed to natural shortening daylengths. Our results indicate that the accumulation of poplar bark storage protein mRNA is controlled by photoperiod. This finding will provide a useful system for investigating photoperiodism in woody plants.
78 citations
TL;DR: Extracts of 54 plant species were tested for ability to inhibit bacteria and fungi, especially Candida albicans, Trichophyton rubrum and Streptococcus mutans, and Lindera benzoin, a common temperate zone shrub, showed evidence of selective toxicity.
Abstract: Extracts of 54 plant species were tested for ability to inhibit bacteria and fungi, especially Candida albicans, Trichophyton rubrum and Streptococcus mutans. The latter three species cause common dermal, mucosal, or oral infections in humans that are difficult to control effectively. Fifteen plant extracts produced detectable antimicrobial activity. The most active included Celastrus scandens root bark, Juglans nigra fruit husks, Kalmia latifolia leaves, Pelargonium xhortorum leaves, and Rhus glabra root bark. Five plant species inhibited Strep. mutans, four inhibited T. rubrum, and two inhibited C. albicans. Lindera benzoin, a common temperate zone shrub, showed evidence of selective toxicity. Extract of L. benzoin bark strongly inhibited C. albicans and T. rubrum, but did not affect any of the other microorganisms tested.
76 citations
TL;DR: In this paper, sesquiterpene-neolignans, eudesobovatos A (1) and B (2), eudesmagnololol (3), eudeshonokiols A (4), B (5), clovanediol (6), and caryolanemagnolols (7), have been isolated from the bark of Magnolia obovata.
73 citations
TL;DR: Attraction of scolytids and other bark- and wood-dwelling beetles to volatile constituents of Norway spruce was studied in field experiments in central Sweden.
Abstract: Attraction of scolytids and other bark- and wood-dwelling beetles to volatile constituents of Norway spruce (Piceaabies (L.) Karst.) was studied in field experiments in central Sweden. The volatile...
67 citations
01 Jan 1992
TL;DR: Studies of the defense systems of trees have focused mostly on xylem tissues because of their direct economic importance to the forest industry, but responses of periderm and other bark tissues to injury and infection are inadequately defined.
Abstract: Studies of the defense systems of trees have focused mostly on xylem tissues because of their direct economic importance to the forest industry. Because bark tissues shield the xylem from the environment, containment of mechanical injuries and infectious microorganisms by bark tissues is of primary importance. The integrity of normal periderm and the ability of plants to form new periderms at wounds or injuries are essential characteristics for normal plant growth and development. However, in comparison with xylem tissues, responses of periderm and other bark tissues to injury and infection are inadequately defined.
65 citations
65 citations
TL;DR: In this paper, two indole alkaloids were obtained from Kopsia lapidilecta Van der Sleesen, and they were elucidated especially by 2D NMR analysis.
64 citations
TL;DR: It is suggested that many of the microorganisms bringing about pine bark composting are thermotolerant, and may not only be able to survive a wide range of temperatures, but also to grow actively at temperatures between 25 and 60°C.
55 citations
TL;DR: Pacific yew trees growing in the shade of a forest canopy and at a site nearby where trees had been exposed to full sunlight for 6 years showed significantly greater quantities of taxol and cephalomannine than in the bark of shaded trees.
Abstract: Taxol and cephalomannine concentrations were measured in the bark and foliage of Pacific yew trees growing in the shade of a forest canopy and at a site nearby where trees had been exposed to full sunlight for 6 years. Bark was the only tissue showing concentration differences due to light, with significantly greater quantities of both compounds in the bark of shaded trees than in the bark of sun-exposed trees. In either light regimen taxol concentrations were greater in the bark than in the needles or twigs
51 citations
TL;DR: The main stilbene, isorhapontin, showed antileukaemic activity and the approximate relative percentage of five major stilbenes in the bark of Picea abies was determined by reversed phase HPLC.
01 Jan 1992
TL;DR: The importance of the bark as a barrier to pests and diseases has become more widely recognized, and significant advances have been made in the understanding of the nature of responses to infection in these tissues.
Abstract: Although the bark of trees provides the initial barrier to agents with the potential to damage the economically important internal woody tissues, it has received comparatively little attention in terms of responses to wounding and infection when compared with the wood itself. Until relatively recently, the majority of studies on bark concentrated on taxonomic comparisons (Eremin 1976) and the relationship between physical properties and commercial uses in consolidated board or reinforced plastic (e.g. Krahmer and Wellons 1973, Wellons and Krahmer 1973, Miller et al. 1974). Examination of bark extractives was based on their potential industrial and pharmaceutical uses (Hergert 1960, Rogers 1967) and little attention was paid to the role of these compounds in the tree itself, despite the fact that, from investigations on other plants, many were known to possess antimicrobial activity. During the past 15 years, however, the importance of the bark as a barrier to pests and diseases has become more widely recognized, and significant advances have been made in our understanding of the nature of responses to infection in these tissues (Mullick 1977, Biggs et al. 1984, Biggs 1985, Pearce 1987, 1989).
TL;DR: Use of the bark of twenty one species of woody plants is documented for the Gitksan, Wet’suwet’en and Haisla peoples of Northwest British Columbia.
Abstract: In the coniferous forest dominated landscape of northwestern British Columbia, bark products were used to fill many needs which in less heavily forested environments were filled by herbaceous plants. Bark from woody shrubs and trees was used for carbohydrate food, medicine, fiber, and structural material. Use of the bark of twenty one species of woody plants is documented for the Gitksan, Wet’suwet’en and Haisla peoples of Northwest British Columbia. Approximately half of the woody species named by these peoples were used for bark resources. Today, most bark derived products have been replaced with manufactured and agricultural products.
TL;DR: Different fresh shoot parts of male and female plants of Taxus cuspidata were extracted and analysed for taxol concentration by high performance liquid chromatography (HPLC), indicating that the bark accounted for almost all the taxol present in stems devoid of needles.
Abstract: Different fresh shoot parts of male and female plants of Taxus cuspidata were extracted and analysed for taxol concentration by high performance liquid chromatography (HPLC). Extracted parts included: young needles (first 10 top needle pairs of 30 cm long branches), old needles (last 10 needle pairs of 30 cm long branches), green bark, dark bark (with intense secondary growth), young wood (originally surrounded by green bark), wood (originally surrounded by dark bark), young stems (surrounded by green bark and devoid of needles), and mature male cones. Dichloromethane extracts were analysed by HPLC and diode array spectroscopy. Taxol identification was done by retention time, U.V. spectra, and spiking with an authentic taxol standard; 1H-NMR analysis was done for needle extracts. All parts except male cones had measurable amounts of taxol; no effect of plant sex on taxol levels of the plant parts analysed was observed. Results indicated that the bark accounted for almost all the taxol present in stems devoid of needles. Needles showed the highest levels of taxol (overall average of 0.035 +/- 0.006% of the extracted dry weight), significantly higher than those displayed by dark bark samples (0.012 +/- 0.001% of the extracted dry weight). Different needle post-harvesting procedures were evaluated in relation to taxol yields, 96 h dark incubation at -12 degrees C and 96 h dark incubation at 25 degrees C under vacuum gave taxol yields equivalent to those of freshly extracted samples. However, results obtained for 96 h dark incubation at 60 degrees C indicated some extent of taxol degradation.
TL;DR: By pollarding the trees, the entire twigs and small branches of paw paw could be processed to produce a potent acetogenin mixture and this biomass could be made available in quantities needed for commercialization of the pesticidal product and could be renewable through regrowth from the parent trunk and larger branches.
Abstract: Various plant parts of the paw paw tree (Asimina triloba Dunal, Annonaceae) were extracted and partitioned to concentrate the mixture of acetogenins into a standardized pesticidal extract (F005). A bioassay with brine shrimp larvae (Artemia salina Leach) was used to determine the relative potencies of the various extracts. The small twigs (0-0.5 cm diameter) yielded the most potent extract (LC50 = 0.04 ppm); the stem wood (LC50 = 4.9 ppm) and leaves (LC50 = 53.7 ppm) yielded the poorest activities. The unripe fruits, seeds, root wood, root bark, and stem bark were notably potent and, generally, yielded > 2% of their dry weight as F005. The smaller diameter stems were more potent than the larger stems. We conclude that, by pollarding the trees, the entire twigs and small branches of paw paw could be processed to produce a potent acetogenin mixture; this biomass could be made available in quantities needed for commercialization of the pesticidal product and could be renewable through regrowth from the parent trunk and larger branches.
TL;DR: Two new lignan glycosides, named hazaleanin A (1) and hazaleinin B (2), and two new apioglucosides were isolated from the bark of Fagara rhetza (Rutaceae), an Indonesian medicinal plant from Flores Island, Indonesia as mentioned in this paper.
Abstract: Two new lignan glycosides, named hazaleanin A (1) and hazaleanin B (2), and two new apioglucosides, named isopropyl apioglucoside (3) and 4-hydroxyguaiacol apioglucoside (4), were isolated from the bark of Fagara rhetza (Rutaceae), an Indonesian medicinal plant from Flores Island, Indonesia. The chemical structures of 1, 2, 3, and 4 have been elucidated on the basis of chemical and physicochemical evidence, including a chiral synthesis of an aglycone derivative of 1.
TL;DR: The chemical composition of the leaf, bark and wood oils of seven Malaysian Cinnamomum species (C. pubescens, C. javanicum and C. camphora) was examined by co-chromatography with authentic samples on three columns of different polarity, capillary GC/MS and selective proton NMR as mentioned in this paper.
Abstract: The chemical composition of the leaf, bark and wood oils of seven Malaysian Cinnamomum species (C. pubescens, C. javanicum, C. iners, C. impressicostatum, C. mollissimum, C. porrectum and C. camphora) was examined by co-chromatography with authentic samples on three columns of different polarity, capillary GC/MS and selective proton NMR. The major components of the leaf, bark and wood oils were identified. These species could be useful new natural sources for safrole, eugenol, linalool, camphor and benzyl benzoate, which are commercially important chemicals in the flavor, fragrance and pharmaceutical industries. The distribution and accumulation of the compounds in different parts of the plant within the same species or among different species may be used for taxonomic purposes and for future use in the identification of possible varieties of Cinnamomum species.
TL;DR: From the root bark of Artocarpus communis, a known compound, cyclomulberrin, and three new pyranoflavonoids, named cyclocomunol, cyclocommunin and dihydroisocycloartomunin are isolated and characterized.
TL;DR: It was found using scanning electron microscopy that bacteria, actinomycetes and fungi were present in relatively low numbers on the bark surface before composting was initiated, but after addition of urea and water to bark heaps, microbial numbers rose, particularly the bacterial fraction.
TL;DR: A rapid and reproducible method for testing the virulence of Cryptonectria parasitica using American chestnut (Castanea dentata) was developed, and virulence was assessed as the area of bark and wood tissue having brown, necrotic cells.
Abstract: A rapid and reproducible method for testing the virulence of Cryptonectria parasitica using American chestnut (Castanea dentata) was developed. Bark- and wood-tissue samples excised from American chestnut tree stems were inoculated with virulent and hypovirulent C. parasitica strains. Samples were incubated at 25 C for 4 days, and virulence was assessed as the area of bark and wood tissue having brown, necrotic cells. Hypovirulent strains damaged an area 2.16 cm 2 or less of each tissue sample, while virulent strains consistently damaged a greater area (3.62-3.67 cm 2 ) []
TL;DR: Two new phenylpropanoids and a new acid amide isolated from the bark of Fagara rhetza, an Indonesian medicinal plant from Flores Island, Indonesia, were found to show a pungent taste and to exert a moderate antimalarial activity in an in vitro test system.
Abstract: Two new phenylpropanoids, named O-geranylsinapyl alcohol (1) and O-geranylconiferyl alcohol (2), and a new acid amide, named hazaleamide (3), were isolated from the bark of Fagara vhetza (Rutaceae), an Indonesian medicinal plant from Flores Island, Indonesia. The chemical structures of 1, 2, and 3 have been plucidated on the basis of their chemical and physicochemical properties. Among the three new compounds, hazaleamide (3) was found to show a pungent taste and to exert a moderate antimalarial activity in a in vitro test system.
Journal Article•
TL;DR: Bark storage proteins accumulate in the inner bark parenchyma of Populus α euramericna cv «I214» and were purified to homogeneity by anion-exchange chromatography and polyacrylamide gel electrophoresis.
TL;DR: Comparisons of the quality of food supply between herbaceous plants and bark of coniferous species during the winter periods of 1987-88 and 1988-89 indicate that voles do not attack conifers because of their high nutritional quality suggesting that other factors such as a good quality alternative food supply (herbaceous plants) are involved.
Abstract: 1. Meadow voles (Microtus pennsylvanicus) are known to inflict severe winter damage on young tree plantations by gnawing the bark. This is often attributed to a lack of quality and quantity of food supply, although no direct evidence has ever been found. A first step in this direction was initiated by comparing the quality of food supply between herbaceous plants and bark of coniferous species during the winter periods of 1987-88 and 1988-89. 2. Food quality was assessed by measuring the content of protein, total nonstructural carbohydrates (TNC) and total phenolics using standard methods. 3. The nutritional value of herbaceous plants was overall much greater than that of the bark of conifers for both winters analysed. Ratios involving protein/phenolics and TNC/phenolics were up to 50 times higher in herbaceous species than bark of conifers. 4. Nutritional components from herbaceous plants did not vary much between winter months unlike the bark tissues of conifers. 5. These results indicate that voles do not attack conifers because of their high nutritional quality suggesting that other factors such as a lack of a good quality alternative food supply (herbaceous plants) are involved.
TL;DR: A new triterpene and its glycosides were isolated from the bark of Schefflera octophylla together with asiatic acid andAsiaticoside, and for the first time asiaticsoside was isolated from a plant other than Centella asoatica.
TL;DR: The sequence of events leading to the restoration of an intact periderm surface in the stem bark of Pinus sylvestris following wounding and challenge with Armillaria ostoyae was determined and a sub-erized impervious tissue (SIT) was produced outside the necrophylactic peridersm (NP).
Abstract: The sequence of events leading to the restoration of an intact periderm surface in the stem bark of Pinus sylvestris following wounding and challenge with Armillaria ostoyae was determined. A sub-erized impervious tissue (SIT) was produced outside the necrophylactic periderm (NP). Al-though A. ostoyae initially infected wounded bark with intracelfularly growing hyphae, these died before penetrating deeply into the bark. Later, intercellularly growing rhizomorphs, which had also developed from the inoculum, penetrated the NP and infected the functional phloem/ cambial zone. Compared to the reactions in uninfected wounded bark, the A. ostoyae infection delayed the formation of NP and reduced the frequency of cells involved in lignification and in SIT, but increased the number of lignified cell layers. The rhizomorph infection reached deeper and lignification was more pronounced in defoliated seedlings than in non-defoliated ones. The importance of structural responses in defence against A. ostoyae is discussed.
TL;DR: The stem bark of Caloncoba glauca has yielded three friedelane triterpenes of which two are characterized by the loss of C-30 and the presence of a C-27, C-15 lactone as discussed by the authors.
TL;DR: An attempt was made to mechanistically explain the apparent link between drought and infestations, through studying after‐effects of drought on the induced defence in stressed trees.
Abstract: The defence of Norway spruce against a combined attack of the bark beetle Ips typographus and its associated blue‐stain fungi is based upon a) constitutive resin stored in ducts of the bark and sapwood, and b) induced resinosis in reaction zones surrounding the point of infection. Empirically, beetle epidemics are associated with external stresses, drought being a particularly prominent factor. An attempt was made to mechanistically explain the apparent link between drought and infestations, through studying after‐effects of drought on the induced defence in stressed trees. In the field, 3–5.5 m tall trees were exposed to artificial drought over three growth seasons to investigate whether this treatment would predispose them to fungal infection in a fourth season when drought was absent. Pre‐dawn xylem water potentials down to ‐1.85 MPa and a considerable foliage depletion were recorded. In the fourth season, the trees were inoculated with Ophiostoma polonicum, a pathogenic associate of Ips typographus. N...
TL;DR: The present study had three objectives: to study the effect of root age on the diversity of endophytic aquatic hyphomycetes in P. glauca, to compare recovery of fungal species by aeration and plating techniques, and to estimate total fungal biomass of aquatic roots by determining their ergosterol content.
Abstract: Aquatic hyphomycetes have been reported from terrestrial root surfaces (Parkinson and Thomas, 1969; Taylor and Parkinson, 1965; Waid, 1954; Watanabe, 1975), bark (Fisher and Petrini, 1989, 1990; Fisher et al., 1991) and xylem (Fisher et al., 1991). Recent studies on aquatic root bark and xylem of Alnus glutinosa (L.) Gaertner (Fisher et al., 1991; Marvanovf and Fisher, 1991), Acer spicatum Lam., Betula papyrifera Marsh. and Picea glauca (Moench) Voss (Sridhar and Biirlocher, 1992) revealed about 20 species of endophytic aquatic hyphomycetes. Somewhat surprisingly in view of the scarcity of aquatic hyphomycetes on conifer needles, roots of white spruce yielded more species than maple or birch (Sridhar and Barlocher, 1992). Fungi were recovered both by plating and by aeration of surface sterilized bark and xylem segments. The present study had three objectives: 1) to study the effect of root age on the diversity of endophytic aquatic hyphomycetes in P. glauca; 2) to compare recovery of fungal species by aeration and plating techniques; and, 3) to estimate total fungal biomass of aquatic roots by determining their ergosterol content. All roots were collected from white spruce (Picea glauca (Moench) Voss) lining Boss Brook, a softwater stream in Fenwick, Nova Scotia, Canada (Barlocher, 1987). Root material submerged in flowing water was procured from five trees during June and July 1991. It was transported to the laboratory in polyethylene bags and processed within 4 h of recovery. Water temperature during the sampling period ranged between 11-13.5 C. The age of the root segments was estimated by counting annual rings of transverse sections under a low power microscope. Four age groups, viz. 2, 4-5, 9-10 and 14-15 yr, were selected for the study. Root diameters were
01 Jan 1992
TL;DR: The results indicate that the microflora of the timber that apparently was undecayed may reach high levels and may contain allergenic and/or toxic species which pose a potential risk for sawmill workers as discussed by the authors.
Abstract: Four series of wood samples were taken from the heartwood, sapwood and bark of six species of timber logs (American basswood, black cherry, black locust, red oak, soft maple and white poplar) in the summer, fall, winter and spring. The samples were examined by dilution plating for total aerobic bacteria, gram-negative bacteria and fungi. The chromogenic modification of the Limulus amebocyte lysate test was also used for bacterial endotoxin. The numbers of the micro-organisms and endotoxin in the wood were significantly higher during warm periods (spring and summer) than during cold periods (fall and winter). They were highest in the wood of American basswood and black locust, exceeding the levels of 107 cfu g−1 and 105 endotoxin units g−1, respectively. Gram-negative bacteria and Corynbacterium spp. prevailed among aerobic bacteria recovered from heartwood and sapwood, while Bacilli spp. were the most common in the bark. Enterobacter agglomerans (synonym: Erwinia herbicola). Agrobacterium radiobacter, Pseudomonas fluorescens, Pseudomonas maltophilia & Acinetobacter calcoaceticus were most common among gram-negative bacteria. Yeasts dominated the fungal flora of heartwood and sapwood, whereas filamentous fungi constituted a prevailing fraction in the bark. The results indicate that the microflora of the timber that apparently was undecayed may reach high levels and may contain allergenic and/or toxic species which pose a potential risk for sawmill workers.