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At least 199 records · Page 11Linked to original sources

PubMed2003

Effects of exogenous gibberellin and auxin on shoot elongation and vegetative bud development in seedlings of Pinus sylvestris and Picea glauca.

The hormonal control of stem unit (foliar appendage and axillary structure, if present, plus subtending internode) number and length was investigated in shoots of Scots pine (Pinus sylvestris L.) and white spruce (Picea glauca (Moench) Voss). Seedlings were treated with six gibberellins (GA1, GA3, GA4, GA5, GA9 and GA20) and two auxins (indole-3-acetic acid (IAA) and naphthaleneacetic acid (NAA)) when either neoformed growth was occurring or the terminal vegetative bud was developing. Hormones were applied by drenching the shoot tip, injecting the stem or spraying the foliage. Combined results for all three application methods indicated that shoot elongation in first-year seedlings (i.e., neoformed growth) was promoted in both species by GA1, GA3, GA4 and, less obviously, by GA9. This promotion was attributable to an increase in length, rather than number, of stem units. However, the number of stem units formed during terminal bud development, as reflected in the number of needles (white spruce) or cataphylls (Scots pine) present on the shoot resulting from the terminal bud, was stimulated by GA1, GA3 and GA4 in both species and by GA9 in Scots pine. The GA-induced increase in the number of preformed stem units was associated with increased bud width in white spruce and increased bud length and resulting shoot length in Scots pine. In contrast, application of IAA or NAA either did not affect or inhibited both neoformed growth and terminal bud stem unit number, depending on the application method and concentration. We conclude that, in the Pinaceae, (1) GA stimulates the activity of both the subapical meristem during neoformed growth and the apical meristem during vegetative bud development, and (2) the early non-hydroxylation pathway, via GA9, is the major route of GA biosynthesis. The role of auxin in the control of stem unit number and length remains to be resolved.

Gibberellins↗

PubMed2003

Biochemical acclimation patterns of Betula pendula and Pinus sylvestris seedlings to elevated carbon dioxide concentrations.

Acclimation of photosynthesis to increasing atmospheric carbon dioxide concentration ([CO2]; 350 to 2,000 micromol mol-1) was followed in silver birch (Betula pendula Roth.) and Scots pine (Pinus sylvestris L.) seedlings for two years. Chlorophyll fluorescence and concentrations of Rubisco, chlorophyll, total soluble protein and nitrogen were monitored together with steady-state gas exchange at three CO2 concentrations (ambient [CO2] (345 +/- 20 micromol mol-1), the growth [CO2] and 1950 +/- 55 micromol mol-1). Rubisco and chlorophyll concentrations decreased in birch and Scots pine with increasing growth [CO2]. A nonlinear response was recorded for Rubisco and chlorophyll concentrations in birch, which was correlated with a significant decrease in specific leaf area. Nitrogen concentration decreased in birch leaves, but was unchanged in Scots pine needles. The species differed substantially in their steady-state CO2 exchange response to increasing growth [CO2]. The principal effect in birch was a significant nonlinear decrease in the steady-state gas exchange rate at the ambient [CO2], whereas in Scots pine the main effect was a significant increase in the steady-state gas exchange rate at the growth [CO2].

Acclimatization↗

PubMed2003

Growth and nutrient uptake of ectomycorrhizal Pinus sylvestris seedlings in a natural substrate treated with elevated Al concentrations.

Models of the effects of elevated concentrations of aluminum (Al) on growth and nutrient uptake of forest trees frequently ignore the effects of mycorrhizal fungi. In this study, we present novel data indicating that ectomycorrhizal mycelia may prevent leaching of base cations and Al. Mycorrhizal and non-mycorrhizal Pinus sylvestris L. seedlings were grown in sand obtained from the B-horizon of a local forest. In Experiment 1, non-mycorrhizal seedlings and seedlings inoculated with Hebeloma cf. longicaudum (Pers.: Fr.) Kumm. ss. Lange or Laccaria bicolor (Maire) Orton were provided with nutrient solution containing 2.5 mM Al. Aluminum did not affect growth of non-mycorrhizal seedlings or seedlings inoculated with L. bicolor. Seedlings colonized by H. cf. longicaudum had the highest biomass production of all seedlings grown without added Al, but the fungus did not tolerate Al. Shoots of seedlings colonized by L. bicolor had the lowest nitrogen (N) concentrations but the highest phosphorus (P) concentrations of all seedlings. The treatments had small but significant effects on shoot and root Al concentrations. In Experiment 2, inoculation with L. bicolor was factorially combined with the addition of a complete nutrient solution, or a solution lacking the base cations K, Ca and Mg, and solutions containing 0 or 0.74 mM Al. Seedling growth decreased in response to 0.74 mM Al, but the effect was significant only for non-mycorrhizal seedlings. Mycorrhizal seedlings generally had higher P concentrations than non-mycorrhizal seedlings. Aluminum reduced P uptake in non-mycorrhizal plants but had no effect on P uptake in mycorrhizal plants. Mycorrhizal colonization increased the pH of the soil solution by about 0.5 units and addition of Al decreased the pH by the same amount. We conclude that the presence of ectomycorrhizal mycelia decreased leaching of base cations and Al from the soil.

Agaricales↗

PubMed2002

Insect egg deposition induces Pinus sylvestris to attract egg parasitoids.

Plant volatiles released in response to feeding insects are known to attract enemies of the feeding herbivores. In this study, egg deposition by a herbivorous insect was shown to induce a gymnosperm plant to emit volatiles that attract egg parasitoids. Odour from twigs of Pinus sylvestris laden with egg masses of the pine sawfly Diprion pini attracts the eulophid egg parasitoid Chrysonotomyia ruforum. Volatiles released from pine twigs without diprionid eggs are not attractive. Oviposition by the sawfly onto pine needles induces not only a local response in pine needles laden with eggs but also a systemic reaction. Needles without eggs but adjacent to those bearing diprionid eggs also release the volatiles that attract the egg parasitoid. The elicitor of the attractive volatiles was shown to be present in the oviduct secretion coating the eggs of D. pini. When pine twigs are treated with jasmonic acid, a well-known plant wound signal, they emit volatiles that attract the egg parasitoid. These results show, for the first time, that a gymnosperm plant is able to attract parasitoids as soon as a herbivore has deposited its eggs on it. Thus, the plant appears to defend itself against herbivores prior to being damaged by feeding larvae.

Animals↗

PubMedDate not supplied

Three highly oxygenated caryophyllene sesquiterpenes from Pestalotiopsis sp., a fungus isolated from bark of Pinus taeda.

A Pestalotiopis sp. was isolated from the trunk bark of Pinus taeda. The fungus was cultivated in liquid medium and produced three highly oxygenated caryophyllene sequiterpene derivatives, named pestalotiopsolide A, taedolidol and 6-epitaedolidol, respectively. The sesquiterpenes were isolated by silica gel based chromatographic procedures and their structures were elucidated by NMR spectroscopic data.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2001

[Relationship between decline disease of exotic pines(Pinus taeda and P. eliottii) and forest stand and environmental factors].

The relationship between decline disease of exotic pines(Pinus taeda and P. eliottii) plantations in Anhui Province and forest stand status and environmental factors was quantitatively analyzed. Among 18 variable factors from 4 types of factors(climate, soil, stand status, and other diseases and insect pests), 10 factors contributed greatly to the state of illness. These were tree age, stand density, resin-tapping, rainfall, temperature, clay soil, stone soil, soil depth, water-logging, and other diseases and insect pests. Of them soil depth and rainfall negatively, and others positively related with the severity of disease. Accordingly, a linear multiple regression model was derived, which might predict the developmental level of decline disease at any given conditions of exotic pine plantation. In addition, the spiral chart of decline disease was mapped based on the action size and time order of various nosogenetic factors during the incidence of decline disease, which was used to visually describe and quantitatively analyze the disease with complicated causes.

Causality↗

PubMedDate not supplied

[Genetic structure, variability and differentiation of Pinus sylvestris L. populations in the Ukrainian Carpathian Mountains and Rastoch'e].

On the basis of electrophoretic analysis of 9 enzymous systems encoded by 20 gene loci the level of intra- and inter-population variation of two relict populations of Pinus sylvestris L. in the Ukrainian Carpathians and two ones in Rastochiye was studied. The less allele representation and the lower level of heterozygosity are typical for the Carpathian populations. Fst and Gst, parameters of populations subdivision, were not high--0.020 and 0.022 correspondingly and the coefficient DN was 0.008 in average. The results of the cluster analysis showed that only the populations of Rastochiye were united in one group indicating their genetic affinity.

Alleles↗

PubMed2002

[Skewness and inequality of height distribution of young Pinus sylvestris var. mongolica stands introduced on sandy soil with lower limited precipitation for tree survival and normal growth].

Based on the investigation of a transect (20 m wide and 80 m long) along a gradient (bottom, middle, and top) of a dune, whose height was about 5-10 m, the population dynamics in young Pinus sylvestis var. mongolica stands was studied. The results showed that both skewness and height inequality declined before the self-thinning process occurred. Age, initial growth status, density of the population, and neighborhood competition were the main factors affected height inequality. The location at sand dune was also an important factor, and its effect was more obvious than that of density.

Chemical Precipitation↗

PubMed2002

[Reproductive development of initial sporophytes in Pinus sylvestris L].

The reproductive development of Pinus sylvestris from generative primordia to sporophyte initial (embryo tier of 16-celled proembryo) was studied. In the reproductive cycle, three types of stages are distinguished and described in association with: 1) hereditary program formation; 2) a new reproductive initial origin, and 3) increase in propogative energy. The layout of disposition of these stages in the reproductive cycle is given.

Pinus↗

PubMed2002

[Activity of nucleoli in cells of different type in early embryogenesis of Pinus sylvestris L].

Early embryogeny of Pinus silvestris L. is characterized by suspensory system formation consisting of several cell generation formed by apical cell fissions. A comparative analysis was made of quantitative characteristics of nucleoli of two functionally different cell types: the apical cells of meristematic nature, and specialized cells resulting from mitotic cycle of suspensory cells. We determined the number of nucleoli and their diameters, the character of distribution and variability of these indices for cells of different types. It has been shown that in the cell cycle, changes of qualitative parameters of nucleoli in cells of secondary suspensors are most dynamic. A conclusion is made that in P. sylvestris L. early embryogeny differences in nucleolar activity and mechanisms of its regulation occur in suspensory cells of different generations. On the basis of differences in nucleolar activity observed in suspensory cells of the same generation, certain mechanisms of competition between cleavage polyembryos of this species are suggested.

Cell Differentiation↗

PubMed2006

[Cold hardiness of Pinus ponderosa, P. banksian and P. tabulaeformis].

By the method of artificial freezing, this paper made a comparative study on the cold hardiness of Pinus ponderosa, P. banksiana and P. tabulaeformis, with their inherent mechanisms approached. The results showed that the cold hardiness of these three species was in the sequence of P. banksiana > P. tabulaeformis > P. ponderosa. P. banksiana had high bound water/free water ratio (7.0) and ABA content (164.3 microg x g(-1) FW) but low K+ (2450 microg x g(-1) DW) and soluble sugar (12.0%) , P. tabulaeformis had higher contents of ABA (95.8 microg x g(-1) FW), K+ (4538 microg x g(-1) DW) and soluble sugar (18.68%) but low bound water/free water ratio (2.58), while P. ponderosa had high soluble sugar content (18.05%) but low bound water/free water ratio (2.18) and K+ (2275 microg x g(-1) DW) and ABA (63.3 microg x g(-1) FW) contents. These differences might be the reasons resulting in the different cold hardiness of these three species. Low chlorophyll content and high carotenoid/chlorophyll ratio might also contribute to the cold hardiness of P. banksiana. Therefore, though the test species are all of cold hardiness, their inherent mechanisms may be different.

Adaptation, Physiological↗

PubMed2006

[Soil respiration of Pinus koraiensis and P. sylvestriformis trees growing at elevated CO2 concentration].

The study with open-top chamber showed that at 500 micromol CO2 x mol(-1), the soil respiration rate under Pinus koraiensis and P. sylvestriformis decreased significantly, probably due to the slow diffusion of increased soil surface CO2 concentration. The soil surface CO2 concentration at 500 micromol CO2 x mol(-1) was significant higher than that in the control chamber and un-chambered field, with an increment of 40-150 micromol CO2 x mol(-1). The soil surface CO2 concentration of P. sylvestriformis in the control chamber was higher than that on unchambered field, but the difference was not significant, while a significant difference was observed in P. koraiensis. The total nitrogen and total organic carbon contents in P. sylvestriformis soil at 500 micromol CO2 x mol(-1) had no significant difference with those in the control chamber and on unchambered field, while their contents in P. koraiensis soil were significantly lower on unchambered field than those in the control chamber and at 500 micromol CO2 x mol(-1). Elevated CO2 and the microenvironment of open-top chamber had little effect on the soil temperature at 3 cm depth.

Carbon Dioxide↗

PubMed2005

A new dihydroflavonol from Pinus sylvestris L.

A novel dihydroflavonol, C-6,O-7-dimethylaromadendrin, was isolated from a 70% aqueous acetone extract of pine (Pinus sylvestris L.) bark. Its structure was determined by high-resolution negative fast atom bombardment mass spectrometry and NMR spectroscopy. The complete assignment of proton and carbon signals was achieved by 2D NMR experiments: HSQC, HMBC, DQF-COSY and NOESY.

Carbon Isotopes↗

PubMed2006

Lignans from the bark extract of Pinus sylvestris L.

Three lignans were isolated from a bioactive fraction of the 70% aqueous acetone extract of the pine (Pinus sylvestris L.) bark. Their structures were identified by high-resolution positive ion EI mass spectrometry and NMR spectroscopy. The complete assignment of proton and carbon signals was achieved by 2D NMR experiments: HSQC, HMBC, DQF-COSY and NOESY.

4-Butyrolactone↗

PubMed2005

Characterization of pollen tube development in Pinus strobus (Eastern white pine) through proteomic analysis of differentially expressed proteins.

The differentially expressed proteins in pollen tubes indicate their specific roles in this stage of male gametophyte development. To isolate these proteins, 2-DE was done using ungerminated pollen and 2-day-old pollen tubes of Pinus strobus. Results show that 645 and 647 protein spots were clearly resolved from pollen grains and pollen tubes, respectively. Thirty-eight protein spots were expressed only in pollen tubes, while 19 increased in intensity. MALDI-TOF MS was used to generate tryptic peptide masses that were submitted to Mascot for identification. Of the differentially expressed proteins, 12% matched with hypothetical proteins, 33% did not hit any protein, and for the 55%, a putative function was assigned based on similarity of sequences with previously characterized proteins. Therefore, pollen tube development can be characterized by the cellular activities that involve metabolism, stress/defense response, gene regulation, signal transduction, and cell wall formation. This study expands our understanding of the changes in protein expression associated with pollen tube development and provides insights into the molecular programs that separate the development of the pollen tubes from pollen grains. This is the first report that describes a global analysis of differentially expressed proteins from the pollen tube of any seed plant.

Cell Wall↗

PubMed2003

Antioxidant principles from the needles of red pine, Pinus densi fl ora.

Antioxidant activity of Pinus densiflora Sieb. et Zucc. (Pinaceae) was evaluated for potential to inhibit hydroxyl radicals, inhibit total reactive oxygen species generation in kidney homogenates using 2',7'-dichlorodihydro fluorescein diacetate (DCHF-DA) and scavenge authentic peroxynitrites. The methanolic extract of P. densiflora showed strong antioxidant activity in the tested model systems and thus fractionated with several solvents. The antioxidant activity potential of the individual fraction was in the order of ethyl acetate > n-butanol > water > dichloromethane fraction. The ethyl acetate soluble fraction exhibiting strong antioxidant activity was further puri fi ed by repeated silica gel and Sephadex LH-20 column chromatographies. An active lignan (+)-isolarisiresinol xylopyranoside, as well as two active flavonoids [kaempferol 3-O-beta-galactopyranoside and its 6"-acetyl derivative], were isolated.

Antioxidants↗

PubMed2005

Potential biomedical properties of Pinus massoniana bark extract.

This study examined the potential biomedical properties of a bark extract from Pinus massoniana Lamb (PMBE). Its antioxidant activity, superoxide anion radical scavenging and free radical scavenging activities were examined. The antioxidant activity in a linoleic acid emulsion increased with increasing amounts of PMBE, with 100, 300 and 500 microg PMBE inhibiting 64.7%, 68.6% and 76.6% of peroxidation, respectively. Similarly, the radical scavenging activity by PMBE increased in a dose-dependent manner, suggesting that there may be a correlation between the antioxidant and scavenging activities. In addition, the effect of PMBE on human hepatocellular carcinoma BEL-7402 cells and normal liver L-02 cells was investigated in vitro. PMBE appeared to inhibit selectively the growth of BEL-7402 and slightly promoted the growth of L-02. Taken together, the results indicate that PMBE is a natural antioxidant that could potentially be used as a food supplement or as a candidate precursor substance for new anticancer therapeutics.

Antineoplastic Agents, Phytogenic↗

PubMed2005

Isopimaric acid from Pinus nigra shows activity against multidrug-resistant and EMRSA strains of Staphylococcus aureus.

The diterpene isopimaric acid was extracted from the immature cones of Pinus nigra (Arnold) using bioassay-guided fractionation of a crude hexane extract. Isopimaric acid was assayed against multidrug-resistant (MDR) and methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentrations (MIC) were 32-64 microg/mL and compared with a commercially obtained resin acid, abietic acid, with MICs of 64 microg/mL. Resin acids are known to have antibacterial activity and are valued in traditional medicine for their antiseptic properties. These results show that isopimaric acid is active against MDR and MRSA strains of S. aureus which are becoming increasingly resistant to antibiotics. Both compounds were evaluated for modulation activity in combination with antibiotics, but did not potentiate the activity of the antibiotics tested. However, the compounds were also assayed in combination with the efflux pump inhibitor reserpine, to see if inhibition of the TetK or NorA efflux pump increased their activity. Interestingly, rather than a potentiation of activity by a reduction in MIC, a two to four-fold increase in MIC was seen. It may be that isopimaric acid and abietic acid are not substrates for these efflux pumps, but it is also possible that an antagonistic interaction with reserpine may render the antibiotics inactive. 1H-NMR of abietic acid and reserpine taken individually and in combination, revealed a shift in resonance of some peaks for both compounds when mixed together compared with the spectra of the compounds on their own. It is proposed that this may be due to complex formation between abietic acid and reserpine and that this complex formation is responsible for a reduction in activity and elevation of MIC.

Abietanes↗