Picea: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are evergreen, pyramidal trees with whorled branches and thin, scaly bark. Each of the linear, spirally arranged leaves is jointed near the stem on a separate woody base.Gymnosperms: Gymnosperms are a group of vascular plants whose seeds are not enclosed by a ripened ovary (fruit), in contrast to ANGIOSPERMS whose seeds are surrounded by an ovary wall. The seeds of many gymnosperms (literally, "naked seed") are borne in cones and are not visible. Taxonomists now recognize four distinct divisions of extant gymnospermous plants (CONIFEROPHYTA; CYCADOPHYTA; GINKGOPHYTA; and GNETOPHYTA).Abies: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. Balm of Gilead is a common name more often referring to POPULUS and sometimes to COMMIPHORA.Coniferophyta: A plant division of GYMNOSPERMS consisting of cone-bearing trees and shrubs.Pinus: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are evergreen trees mainly in temperate climates.Trees: Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.Wood: A product of hard secondary xylem composed of CELLULOSE, hemicellulose, and LIGNANS, that is under the bark of trees and shrubs. It is used in construction and as a source of CHARCOAL and many other products.Plant Stems: Parts of plants that usually grow vertically upwards towards the light and support the leaves, buds, and reproductive structures. (From Concise Dictionary of Biology, 1990)Botany: The study of the origin, structure, development, growth, function, genetics, and reproduction of plants.Pinaceae: A plant family of the order Pinales, class Pinopsida, division Coniferophyta, known for the various conifers.Weevils: BEETLES in the family Curculionidae and the largest family in the order COLEOPTERA. They have a markedly convex shape and many are considered pests.Pseudotsuga: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are coniferous evergreen trees with long, flat, spirally arranged needles that grow directly from the branch.
AstringinBennettites: Bennettites refers to an extinct genus of the order Bennettitales.List of Copper Country minesBert (horse): Bert}}Pinus pinasterPeat swamp forest: Peat swamp forests are tropical moist forests where waterlogged soil prevents dead leaves and wood from fully decomposing. Over time, this creates a thick layer of acidic peat.Wood fibre: Wood fibers are usually cellulosic elements that are extracted from trees and used to make materials including paper.Pith: 250px|right|thumb|[[Elderberry shoot cut longitudinally to show the broad, solid pith (rough-textured, white) inside the wood (smooth, yellow-tinged). Scale in mm.Hardening (botany): Hardening in botany is the process by which an individual plant becomes tolerant to the effects of freezing during a period of weeks to months. It is a three-stage process.Pinus lambertiana: Pinus lambertiana (commonly known as the sugar pine or sugar cone pine) is the tallest and most massive pine tree, and has the longest cones of any conifer. The species name lambertiana was given by the British botanist David Douglas, who named the tree in honour of the English botanist, Aylmer Bourke Lambert.Rice weevilPseudotsuga lindleyana: Pseudotsuga lindleyana, commonly known as the Mexican Douglas-fir, is a conifer in the genus Pseudotsuga that is endemic to Mexico. DNA sequence and morphological evidence suggests it is most closely related to Rocky Mountain Douglas-fir (P.
(1/229) Xylem water content and wood density in spruce and oak trees detected by high-resolution computed tomography.
Elucidation of the mechanisms involved in long-distance water transport in trees requires knowledge of the water distribution within the sapwood and heartwood of the stem as well as of the earlywood and latewood of an annual ring. X-ray computed tomography is a powerful tool for measuring density distributions and water contents in the xylem with high spatial resolution. Ten- to 20-year-old spruce (Picea abies L. KARST.) and oak (Quercus robur) trees grown in the field were used throughout the experiments. Stem and branch discs were collected from different tree heights, immediately deep frozen, and used for the tomographic determinations of spatial water distributions. Results are presented for single-tree individuals, demonstrating heartwood and sapwood distribution throughout their entire length as well as the water relations in single annual rings of both types of wood. Tree rings of the sapwood show steep water gradients from latewood to earlywood, whereas those of the heartwood reflect water deficiency in both species. Although only the latest two annual rings of the ringporous species are generally assumed to transport water, we found similar amounts of water and no tyloses in all rings of the oak sapwood, which indicates that at least water storage is important in the whole sapwood. (+info)
(2/229) An improved procedure for production of white spruce (Picea glauca) transgenic plants using Agrobacterium tumefaciens.
An efficient and reproducible procedure for the transformation of white spruce (Picea glauca [Moench] Voss) embryogenic tissues was developed using A. tumefaciens-mediated gene transfer. Rapidly dividing white spruce embryogenic tissues were co-cultivated with disarmed A. tumefaciens strains containing additional copies of the virulence regions from plasmid PToK47. The plasmid pBi121, containing the neomycin phosphotransferase II (nptII) gene providing kanamycin resistance as a selectable marker and the beta-glucuronidase (uidA) reporter gene, was used as binary vector. The highest frequency of transformation (15 transformed tissues g(-1) FW of treated embryogenic tissue) was obtained with 5-d-old tissues grown in liquid medium and co-cultivated with Agrobacterium for 2 d in the same medium but containing 50 microM acetosyringone. Recovery of kanamycin-resistant tissues was improved when tissues were first grown for 10 d on a timentin-containing medium (400 mg l(-1)), to prevent bacterial overgrowth, before application of the selection pressure. After 6 weeks on kanamycin-selection medium, resistant tissues were obtained and showed stable uidA expression. The presence of the transgenes was demonstrated by PCR analysis and their integration into the genome was confirmed by Southern hybridization. Transgenic plants were regenerated from transformed tissues within 4 months after co-culture. (+info)
(3/229) Analysis of carbohydrate metabolism enzymes and cellular contents of sugars and proteins during spruce somatic embryogenesis suggests a regulatory role of exogenous sucrose in embryo development.
Carbohydrate metabolism was investigated during spruce somatic embryogenesis. During the period of maintenance corresponding to the active phase of embryogenic tissue growth, activities of soluble acid invertase and alkaline invertase increased together with cellular glucose and fructose levels. During the same time, sucrose phosphate synthase (SPS) activity increased while sucrose synthase (SuSy) activity stayed constant together with the cellular sucrose level. Therefore, during maintenance, invertases were thought to generate the hexoses necessary for embryogenic tissue growth while SuSy and SPS would allow cellular sucrose to be kept at a constant level. During maturation on sucrose-containing medium, SuSy and SPS activities stayed constant whereas invertase activities were high during the early stage of maturation before declining markedly from the second to the fifth week. This decrease of invertase activities resulted in a decreased hexose:sucrose ratio accompanied by starch and protein deposition. Additionally, carbohydrate metabolism was strongly modified when sucrose in the maturation medium was replaced by equimolar concentrations of glucose and fructose. Essentially, during the first 2 weeks, invertase activities were low in tissues growing on hexose-containing medium while cellular glucose and fructose levels increased. During the same period, SuSy activity increased while the SPS activity stayed constant together with the cellular sucrose level. This metabolism reorganization on hexose-containing medium affected cellular protein and starch levels resulting in a decrease of embryo number and quality. These results provide new knowledge on carbohydrate metabolism during spruce somatic embryogenesis and suggest a regulatory role of exogenous sucrose in embryo development. (+info)
(4/229) Endogenous Nod-factor-like signal molecules promote early somatic embryo development in Norway spruce.
Embryogenic cultures of Norway spruce (Picea abies) are composed of pro-embryogenic masses (PEMs) and somatic embryos of various developmental stages. Auxin is important for PEM formation and proliferation. In this report we show that depletion of auxin blocks PEM development and causes large-scale cell death. Extracts of the media conditioned by embryogenic cultures stimulate development of PEM aggregates in auxin-deficient cultures. Partial characterization of the conditioning factor shows that it is a lipophilic, low-molecular-weight molecule, which is sensitive to chitinase and contains GlcNAc residues. On the basis of this information, we propose that the factor is a lipophilic chitin oligosaccharide (LCO). The amount of LCO correlates to the developmental stages of PEMs and embryos, with the highest level in the media conditioned by developmentally blocked cultures. LCO is not present in nonembryogenic cultures. Cell death, induced by withdrawal of auxin, is suppressed by extra supply of endogenous LCO or Nod factor from Rhizobium sp. NGR234. The effect can be mimicked by a chitotetraose or chitinase from Streptomyces griseus. Taken together, our data suggest that endogenous LCO acts as a signal molecule stimulating PEM and early embryo development in Norway spruce. (+info)
(5/229) Identification of a hydrophobin gene that is developmentally regulated in the ectomycorrhizal fungus Tricholoma terreum.
The symbiosis between ectomycorrhizal fungi and trees is an essential part of forest ecology and depends entirely on the communication between the two partners for establishing and maintaining the relationship. The identification and characterization of differentially expressed genes is a step to identifying such signals and to understanding the regulation of this process. We determined the role of hydrophobins produced by Tricholoma terreum in mycorrhiza formation and hyphal development. A hydrophobin was purified from culture supernatant, and the corresponding gene was identified. The gene is expressed in aerial mycelium and in mycorrhiza. By using a heterologous antiserum directed against a hydrophobin found in the aerial mycelium of Schizophyllum commune, we detected a hydrophobin in the symbiosis between T. terreum and its native pine host Pinus sylvestris. The hydrophobin was found in aerial mycelium of the hyphal mantle and also in the Hartig net hyphae, which form the interface between both partners. Interestingly, this was not the case in the interaction of T. terreum with a host of low compatibility, the spruce Picea abies. The differential expression with respect to host was verified at the transcriptional level by competitive PCR. The differential protein accumulation pattern with respect to host compatibility seen by immunofluorescence staining can thus be attributed at least in part to transcriptional control of the hyd1 gene. (+info)
(6/229) High expression of putative aquaporin genes in cells with transporting and nutritive functions during seed development in Norway spruce (Picea abies).
Aquaporins mediate the bidirectional passage of water over membranes and are present in tonoplasts (TIPs) and in plasma membranes (PIPs) of plant cells. Knowing their expression in different tissues is valuable when assessing their contribution to plant water relations. A TIP-gene has been cloned from developing female gametophytes of Picea abies, a conifer displaying an embryology different from the angiosperms. Probes were made from conserved regions of the TIP gene and used for in situ hybridization to examine the gene expression pattern in developing female reproductive structures. Early during development high transcript expression was found in the spongy tissue encasing the developing female gametophyte, in cells of the future seed coat of young ovules and in vascular tissue of the ovuliferous scale. At later stages a strong signal was seen in archegonia jacket cells surrounding egg cells and, still later, at the time of storage protein accumulation, in storage parenchyma cells of the gametophyte as well. These aquaporin-homologues probably participate in regulating water balance in the cells although they could also be permeable to other molecules than water. (+info)
(7/229) Methyl jasmonate induces traumatic resin ducts, terpenoid resin biosynthesis, and terpenoid accumulation in developing xylem of Norway spruce stems.
Norway spruce (Picea abies L. Karst) produces an oleoresin characterized by a diverse array of terpenoids, monoterpenoids, sesquiterpenoids, and diterpene resin acids that can protect conifers against potential herbivores and pathogens. Oleoresin accumulates constitutively in resin ducts in the cortex and phloem (bark) of Norway spruce stems. De novo formation of traumatic resin ducts (TDs) is observed in the developing secondary xylem (wood) after insect attack, fungal elicitation, and mechanical wounding. Here, we characterize the methyl jasmonate-induced formation of TDs in Norway spruce by microscopy, chemical analyses of resin composition, and assays of terpenoid biosynthetic enzymes. The response involves tissue-specific differentiation of TDs, terpenoid accumulation, and induction of enzyme activities of both prenyltransferases and terpene synthases in the developing xylem, a tissue that constitutively lacks axial resin ducts in spruce. The induction of a complex defense response in Norway spruce by methyl jasmonate application provides new avenues to evaluate the role of resin defenses for protection of conifers against destructive pests such as white pine weevils (Pissodes strobi), bark beetles (Coleoptera, Scolytidae), and insect-associated tree pathogens. (+info)
(8/229) Molecular identification of ectomycorrhizal mycelium in soil horizons.
Molecular identification techniques based on total DNA extraction provide a unique tool for identification of mycelium in soil. Using molecular identification techniques, the ectomycorrhizal (EM) fungal community under coniferous vegetation was analyzed. Soil samples were taken at different depths from four horizons of a podzol profile. A basidiomycete-specific primer pair (ITS1F-ITS4B) was used to amplify fungal internal transcribed spacer (ITS) sequences from total DNA extracts of the soil horizons. Amplified basidiomycete DNA was cloned and sequenced, and a selection of the obtained clones was analyzed phylogenetically. Based on sequence similarity, the fungal clone sequences were sorted into 25 different fungal groups, or operational taxonomic units (OTUs). Out of 25 basidiomycete OTUs, 7 OTUs showed high nucleotide homology (> or = 99%) with known EM fungal sequences and 16 were found exclusively in the mineral soil. The taxonomic positions of six OTUs remained unclear. OTU sequences were compared to sequences from morphotyped EM root tips collected from the same sites. Of the 25 OTUs, 10 OTUs had > or = 98% sequence similarity with these EM root tip sequences. The present study demonstrates the use of molecular techniques to identify EM hyphae in various soil types. This approach differs from the conventional method of EM root tip identification and provides a novel approach to examine EM fungal communities in soil. (+info)