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PubMed1998

Gene structure, expression in Escherichia coli and biochemical properties of the NAD+ -dependent glyceraldehyde-3-phosphate dehydrogenase from Pinus sylvestris chloroplasts.

Photosynthetic eukaryotes typically possess two distinct glyceraldehyde-3-phosphate dehydrogenases, an NAD+ -specific enzyme in the cytosol (GapC: EC 1.2.1.12) and an NADP+ -dependent enzyme in the chloroplast (GapAB: EC 1.2.1.13). The gymnosperm Pinus sylvestris is an exception in that it is known to express a gene encoding a transit peptide-bearing GapC-like subunit that is imported into chloroplasts (GapCp), but the enzymatic properties of this novel GAPDH have not been described from any source. We have expressed the mature GapCp unit from Pinus in Escherichia coli and have characterized the active enzyme. GapCp has a specific activity of 89 units per milligram and is strictly NAD+ -dependent, showing no detectable activity with NADP+. Values of the apparent Km for NAD+ and glyceraldehyde-3-phosphate were determined as 62 and 344 microM, respectively. The Pinus GapCpl gene possesses 12 introns, two in the region encoding the transit peptide and ten in the region encoding the mature subunit, all of which are found at positions strictly conserved across genes for higher plant GapC. A cDNA encoding a homologue of GapCp was isolated from the heterosporous fern Marsilea quadrifolia, indicating that NAD+ -dependent chloroplast GAPDH also occurs in other higher plants.

Amino Acid Sequence↗
PubMed1999

Isolation and characterization of a cDNA clone encoding a putative white spruce glycine-rich RNA binding protein.

A presumably full-length cDNA encoding a putative glycine-rich RNA binding protein was isolated from a lambdaZAP cDNA library prepared from mRNAs extracted from needles of 2year old white spruce seedlings, which had been either wounded or jasmonate-treated. The cDNA, designated PgRNP (Picea glauca RNP protein), presents a 468bp open reading frame encoding a 155 amino acid protein. This polypeptide possesses an RNA binding domain (RNP-CS) and a glycine-rich domain. Comparative alignment reveals extensive homologies to glycine-rich RNA binding proteins containing an RNP-CS found in other angiosperm species. Genomic hybridization experiments suggest that the PgRNP gene is part of a small multigene family with at least four members. RNA blot analysis revealed that the PgRNP transcript is expressed in all tissues from non-stressed plants. Constitutive mRNA level was found in needle tissue from control as well as methyl-jasmonate treated plants. Wounding had no clear induction effect. Jasmonic acid treatment and systemic wound response had a positive effect on transcript accumulation. Transcript accumulation was slightly induced by cold in needles, and repressed by drought stress in both needle and root tissues of 2year old plants. Finally, the level of PgRNP accumulation was induced by wounding and repressed in 2week old dark-grown seedlings upon jasmonate treatments.

Acetates↗
PubMed2000

Pharmacological activity of Abies pindrow.

The widely known tree Abies pindrow (Talisapatra) (family: Pinaceae), famous for its diverse clinical uses in Ayurvedic medicines, was investigated to rationalise some of the ancient claims. The petroleum ether (PE), benzene (BE), chloroform (CE), acetone (AE) and ethanol (EE) extracts of A. pindrow leaf were found to have mast cell stabilizing action in rats. The EE, AE and BE extracts offered bronchoprotection against histamine challenge in guinea-pigs. The BE, CE and PE extracts had protective role in aspirin-induced ulcer in rats. The results suggest that while terpenoids, flavonoids, glycosides and steroids are involved in mast cell protection, terpenoids and flavonoids are brochoprotective against histamine-induced bronchospasm. The ulcer protective action of PE, BE and CE fractions of A. pindrow may be attributable to steroids contents only because though all the extracts tested positive for glycosides, the extracts EE and AE did not have any ulcer protective role.

Animals↗
PubMed2001

Effects of Sclerocarya birrea (A. rich) hochst (anacardiaceae) leaf extracts on calcium signalling in cultured rat skeletal muscle cells.

Sclerocarya birrea is a plant used widely to treat many diseases in Burkina Faso, although no scientific data has been reported about its mechanism of action. In the present study the effects of its leaf extracts were investigated on calcium signalling in rat cultured skeletal muscle cells. The results show that the different extracts (crude decoction, aqueous, ethanolic and chloroformic extracts) have significant antagonistic effect on caffeine-induced calcium release from sarcoplasmic reticulum. Crude decoction is the most active followed by ethanolic, aqueous and chloroformic extracts in dose-dependent manner and can partly justify the use of the plant in traditional medicine.

Animals↗
PubMed2001

Studies on pharmaceutical ethnobotany in the region of Pallars (Pyrenees, Catalonia, Iberian Peninsula). Part I. General results and new or very rare medicinal plants.

An ethnobotanical survey was carried out in the region called Pallars--constituted by two districts, Pallars Sobirà and Pallars Jussà--situated in the Central Pyrenees, in North West Catalonia (Iberian Peninsula), with an approximate area of 2530 km(2) and a population of 19000. We obtained data on 437 plant species used for health care through interviews with 264 people. We detected 867 unreported or uncommon uses corresponding to 272 plant species, 52 of which had never or very rarely been cited as medicinal. To present the most important findings concerning the ethnopharmacology of the area studied, this first part includes the general results and the new or very scarcely reported medicinal vascular plants. Further papers will deal with unreported or very uncommon uses for known medicinal plant species and with medicinal non-vascular plants.

Chemistry, Pharmaceutical↗
PubMed2000

The computation of forest leaf area index on slope using fish-eye sensors.

Leaf area index (LAI) measured with fish-eye sensors is inevitably affected by slope. In order to quantify this effect, LAIs measured in contrasted forests were corrected for slope. Digitised hemispherical photographs were analysed to compute LAI according to azimuth and as a function of slope. The topographic mask (part of hemisphere obstructed by slope) and the path length of a ray of light at a given zenith angle (longer upslope and shorter downslope) were taken into account. Results indicate a strong slope effect, both in temperate conifer forest plantation and in tropical rain forest. On regular slope, this effect is easily corrected, although the topographic mask affects data. On irregular topography, corrected and uncorrected LAIs strongly differ, suggesting a need for reference measurements; corrected figures appear nevertheless realistic and normality is reached only for corrected values. LAIs should systematically be corrected for slope above 15-20 degrees, more so if topography is irregular or the forest cover heterogeneous.

Cycadopsida↗
PubMed2001

Dioecy in Fitzroya cupressoides (Molina) I.M. Johnst. and Pilgerodendron uviferum (D. Don.) Florin (Cupressaceae).

The aim of this study was to determine the dioecious or monoecious condition of Fitzroya cupressoides and Pilgerodendron uviferum. The study area lies west of the Nahuel Huapi National Park in northern Patagonia (Argentina), where these species form mixed stands. One hundred individuals of each species were studied over three successive years. The nature and position in the crown of their reproductive organs were recorded. Results showed that both species are dioecious. This feature has been confirmed on trees of these species growing in other sites within their natural distribution area in Argentina and Chile.

Argentina↗
PubMed2000

Pine bark extract pycnogenol downregulates IFN-gamma-induced adhesion of T cells to human keratinocytes by inhibiting inducible ICAM-1 expression.

Expression of intercellular adhesion molecule-1 (ICAM-1) is necessary for leukocyte/keratinocyte interactions. Upregulation of ICAM-1 expression in keratinocytes has been observed in several inflammatory dermatoses, such as psoriasis, atopic dermatitis, and lupus erythematosus. Inflammatory cytokines, such as interferon-gamma (IFN-gamma), upregulate ICAM-1 expression in keratinocytes. Because of potent antioxidant and anti-inflammatory properties of the French maritime pine bark extract, Pycnogenol (Horphag Research, Geneva, Switzerland), its effects were investigated on the interaction of T cells with keratinocytes after activation with IFN-gamma and the molecular mechanisms involved in such interactions. Studies were performed using a human keratinocyte cell line, HaCaT. Cell adhesion in the presence of IFN-gamma was studied using a coculture assay. Treatment of HaCaT cells with 20 U/ml IFN-gamma for 24 h markedly induced adherence of Jurkat T cells to HaCaT cells. PYC pretreatment (50 microg/ml, 12 h) significantly inhibited IFN-gamma induced adherence of T cells to HaCaT cells (p < .01). ICAM-1 plays a major role in the IFN-gamma-induced adherence of T cells to keratinocytes. Thus, the effect of PYC on IFN-gamma-induced ICAM-1 expression was investigated as well. Pretreatment of HaCaT cells with PYC significantly inhibited IFN-gamma-induced expression of ICAM-1 expression in HaCaT cells. The downregulation of inducible ICAM-1 expression by PYC was both dose and time dependent. A 50 microg/ml dose of PYC and a 12 h pretreatment time (i.e., before activation with IFN-gamma) provided maximal (approximately 70%) inhibition of inducible ICAM-1 expression in HaCaT cells. Gamma-activated sequence present on the ICAM-1 gene confers IFN-gamma responsiveness in selected cells of epithelial origin (e.g., keratinocytes) that are known to express ICAM-1 on activation with IFN-gamma. Gel-shift assays revealed that PYC inhibits IFN-gamma-mediated activation of Stat1, thus suggesting a transcriptional regulation of inducible ICAM-1 expression by PYC. These results indicate the therapeutic potential of PYC in patients with inflammatory skin disorders.

Antioxidants↗
PubMed2000

Bacterial endobionts in the big non-mycorrhizal roots of Scots pine (Pinus sylvestris L.).

Subsurface bacterial growth occurred in an N-free medium inoculated with interior tissues of big non-mycorrhizal roots (7 to 8 mm diameter) of 15-20 years-old Scots pine (Pinus sylvestris L.) growing on sand dunes at the Baltic Sea of Poland. The bacteria were not N2 fixers as determined by the acetylene reduction method. Light microscopic and scanning electron microscopic observations revealed massive bacterial clusters residing in the cortical cells underlying epidermis and parenchyma. The bacteria produced yellow-green pigments on King's medium, which fluoresced under ultraviolet (UV) irradiation at 366 nm wavelength, and could be a siderophore-producing Pseudomonas.

Cycadopsida↗
PubMed2001

Molecular weight distribution of Pinus radiata kraft mill wastewater treated by anaerobic digestion.

Kraft mill is responsible for massive discharge of highly polluted effluents. The main characteristics of this effluent are high toxicity and low biodegradability due to tannin, lignin and chlorophenol compounds. The composition may vary dramatically depending, for instance, on the utilised feedstock and process. The purpose of this work was to investigate the molecular weight distribution of Pinus radiata kraft pulping wastewater treated by anaerobic digestion by using two types of anaerobic reactors: fixed bed and sludge blanket. Anaerobic sludge blanket (UASB) and anaerobic filter (AF) were operated. In both reactors, the total alkalinity ranged between 1.0 and 1.5 g CaCO3/l, while the organic load rate (OLR) was increasing during operation from 1.2 to 3.3 gCOD/l d. COD and total phenolic compounds (UV215) removal ranged between 30-50% and 13-20%, respectively, while the BOD5 removal ranged 60-90%. However only a partial biodegradation (10-43%) of tannin and lignin was observed. Results from ultrafiltration analyses indicated that the fraction with a molecular weight (MW) < 1000, COD and colour decreased after anaerobic treatment, but the total phenolic compounds increased. In the 1000 < MW < 10,000 fraction, there was no change in COD, UV215 and colour. In the > 10,000 MW fraction, colour and COD fraction increased by 14% and 5%, respectively, after anaerobic treatment. It can be concluded from this study, that treatment with UASB or AF reactors is not enough, under the conditions tested, for a large COD removal from Pinus radiata wastewater.

Anaerobiosis↗
PubMed2001

Allometry and biomass of Korean pine (Pinus koraiensis) in central Korea.

Aboveground tree biomass of Korean pine (Pinus koraiensis Sieb. et Zucc.) was determined for a natural forest of Korean pine and mixed deciduous trees and seven age classes of plantation forests in central Korea. Regression analyses of the dry weights of stem wood, stem bark, branches, and needles versus diameter at breast height were used to calculate regression equations of the form of log Y = a + b log X. Biomass of Korean pine in the mixed forest was 118 Mg ha(-1), and biomass in the plantations was linearly related to stand age, ranging from 52.3 Mg ha(-1) in 11 to 20-year-old stands to 317.9 Mg ha(-1) in 71 to 80-year-old stands. The proportions of stem wood and stem bark in the total aboveground biomass decreased with stand age while those of branch and needle increased. Specific leaf area of Korean pine ranging from 35.2 to 52.1 cm2 g(-1) was significantly different among crown positions and needle ages; in general, lower crown position and current needles had the greatest surface area per unit dry weight.

Biomass↗
PubMed2000

Seed plant phylogeny: Demise of the anthophyte hypothesis?

Recent molecular phylogenetic studies indicate, surprisingly, that Gnetales are related to conifers, or even derived from them, and that no other extant seed plants are closely related to angiosperms. Are these results believable? Is this a clash between molecules and morphology?

Cycadopsida↗
PubMed2000

The distribution of 137Cs and 90Sr in the biomass of pine trees planted in 1987-1988 in the near zone of the Chernobyl nuclear power plant.

This paper presents the results of a study, carried out in 1996, of the distributions of 137Cs and 90Sr in the biomass of a new pine plantation, planted in 1987-1988, in the near field of the Chernobyl nuclear power plant. The maximum observed concentrations were 4.2 MBq kg(-1) for 137Cs in the youngest needles and 1.1 MBq kg(-1) for 90Sr in the oldest needles. The estimation of the total absorbed doses in the different organs of the pine was also carried out, the observed doses were in the range 2 Gy yr(-1) to 16.8 Gy yr(-1); the lifetime dose for the needles (4 yr) was 44 Gy.

Biomass↗
PubMed2002

Missing links: the genetic architecture of flowers [correction of flower] and floral diversification.

To understand the genetic architecture of floral development, including the origin and subsequent diversification of the flower, data are needed not only for a few model organisms but also for gymnosperms, basal angiosperm lineages and early-diverging eudicots. We must link what is known about derived model plants such as Arabidopsis, snapdragon and maize with other angiosperms. To this end, we suggest a massive evolutionary genomics effort focused on the identification and expression patterns of floral genes and elucidation of their expression patterns in 'missing-link' taxa differing in the arrangement, number and organization of floral parts.

Cycadopsida↗
PubMed2002

Pleiotropy, redundancy and the evolution of flowers.

Most angiosperm flowers are tightly integrated, functionally bisexual shoots that have carpels with enclosed ovules. Flowering plants evolved from within the gymnosperms, which lack this combination of innovations. Paradoxically, phylogenetic reconstructions suggest that the flowering plant lineage substantially pre-dates the evolution of flowers themselves. We provide a model based on known gene regulatory networks whereby positive selection on a single, partially redundant gene duplicate 'trapped' the ancestors of flower-bearing plants into the condensed, bisexual state approximately 130 million years ago. The LEAFY (LFY) gene of Arabidopsis encodes a master regulator that functions as the main conduit of environmental signals to the reproductive developmental program. We directly link the elimination of one LFY paralog, pleiotropically maintained in gymnosperms, to the sudden appearance of flowers in the fossil record.

Arabidopsis↗
PubMed2002

Deciding among green plants for whole genome studies.

Recent comparative DNA-sequencing studies of chloroplast, mitochondrial and ribosomal genes have produced an evolutionary tree relating the diversity of green-plant lineages. By coupling this phylogenetic framework to the explosion of information on genome content, plant-genomic efforts can and should be extended beyond angiosperm crop and model systems. Including plant species representative of other crucial evolutionary nodes would produce the comparative information necessary to understand fully the organization, function and evolution of plant genomes. The simultaneous development of genomic tools for green algae, bryophytes, 'seed-free' vascular plants and gymnosperms should provide insights into the bases of the complex morphological, physiological, reproductive and biochemical innovations that have characterized the successful transition of green plants to land.

Bryopsida↗
PubMed2003

Cycads: evolutionary innovations and the role of plant-derived neurotoxins.

Cycads are an important relic from the past and represent the oldest living seed plants. Cycads have been instrumental in our understanding the evolution of angiosperms and gymnosperms because they have recognizable morphological characteristics intermediate between less-recently evolved plants such as ferns and more-derived (advanced) plants including the angiosperms. Cycads also produce several compounds that are carcinogenic and neurotoxic. Because of their unique placement in terrestrial plant evolution, molecular studies should help to define the origins of structures that led to the rise of seed plants and the role of neurotoxic compounds that are found in cycads.

Biological Evolution↗
PubMed2002

The genetics of plant morphological evolution.

Considerable progress has been made in identifying genes that are involved in the evolution of plant morphologies. Elements of the ABC model of flower development are conserved throughout angiosperms, and homologous MADS-box genes function in gymnosperm reproduction. Candidate gene and mapping analyses of floral symmetry, sex determination, inflorescence architecture, and compound leaves provide intriguing glimpses into the evolution of morphological adaptations.

ATP-Binding Cassette Transporters↗