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First known fire scar on a fossil tree trunk provides evidence of Late Triassic wildfire

Byers, Bruce A.; Ash, Sidney R.; Chaney, Dan; DeSoto, Lucía
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
26.03%
Fire scars are well known to fire ecologists and dendrochronologists worldwide, and are used in dating fires and reconstructing the fire histories of modern forests. Evidence of fires in ancient forests, such as fossil charcoal (fusain), is well known to paleontologists and has been reported in geologic formations dating back to the Late Devonian. We describe what we conclude is a fire scar on a fossil tree trunk from the Late Triassic Chinle Formation of southeastern Utah (~ 200–225 Ma). The external features of the prehistoric scar match those of modern fire scars better than those of scars created by other kinds of wounding events. The fossil specimen also exhibits a number of changes in wood anatomy similar to those reported in modern fire-scarred trees, including a band of very small tracheids that indicate growth suppression immediately associated with the scarring event; an area with a tangential row of probable traumatic resin ducts; and a significant increase in tracheid size following the scarring event that indicates a growth release. No fire scar resembling those in modern trees has previously been described in petrified wood as far as we can determine. The presence of a fire scar not only provides further evidence of ancient fires...

The oleoresin secretory system in seedlings and adult plants of copaiba (Copaifera langsdorffii Desf., Leguminosae-Caesalpinioideae)

RODRIGUES, Tatiane Maria; TEIXEIRA, Simone de Padua; MACHADO, Silvia Rodrigues
Fonte: ELSEVIER GMBH, URBAN & FISCHER VERLAG Publicador: ELSEVIER GMBH, URBAN & FISCHER VERLAG
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.21%
The ecological and economic importance of oleoresin produced by Copaifera langsdorffii is well established. This study aims to investigate the ontogeny, anatomy and ultrastructure of the internal glands of C. langsdorffii during plant development. Samples were processed for light and electron microscopy and a specific technique was applied to impregnate endomembranes. Internal secretory glands were observed in the hypocotyl, epicotyl and eophylls of seedlings, and in the primary stem, pulvinus, petiole, rachis and leaf blade of adult plants. Canals and cavities show differential distribution. They arise from ground meristem cells, and the lumen is first formed by schizogenesis followed by later schizolysigenous development. The dense cytoplasm of epithelial cells shows mitochondria, plastids without thylakoids, polyribosomes and endoplasmic reticulum. A periplastidial reticulum was also observed. Secretion is released by eccrine, granulocrine and holocrine processes. Lipophilic and hydrophilic compounds were histochemically detected in both canals and cavities, whereas resin was detected only in canals. The presence of these substances has been associated with plants` defences against dehydration, as well as against attacks from herbivores and pathogens...

Oleoresin glands in copaiba (Copaifera trapezifolia Hayne: Leguminosae), a Brazilian rainforest tree

Milani, Juliana Foresti; Rocha, Joecildo Francisco; Teixeira, Simone de Pádua
Fonte: SPRINGER; NEW YORK Publicador: SPRINGER; NEW YORK
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
26.03%
Although studies have addressed the chemical analysis and the biological activity of oleoresin in species of Copaifera, the cellular mechanisms of oleoresin production, storage, and release have rarely been investigated. This study detailed the distribution, ontogeny, and ultrastructure of secretory cavities and canals distributed in leaf and stem, respectively, of Copaifera trapezifolia, a Brazilian species included in a plant group of great economic interest. Axillary vegetative buds, leaflets, and portions of stem in primary and secondary growth were collected and processed in order to study the anatomy, histolocalization of substances, and ultrastructure. Secretory cavities are observed in the foliar blade and secretory canals in the petiolule and stem. They are made up of a uniseriate epithelium delimiting an isodiametric or elongated lumen. Biseriate epithelium is rarely observed and is a novelty for Leguminosae. Cavities and canals originate from ground meristem cells and the lumen is formed by schizogenesis. The content of the cavities and canals of both stem and leaf is oily and resinous, which suggests that the oleoresin could be extracted from the leaf instead of the stem. Phenolic compounds are also detected in the epithelial cell cytoplasm. Cavities and canals in the beginning of developmental stages have polarized epithelial cells. The cytoplasm is rich in smooth and rough endoplasmic reticula connected to vesicles or plastids. Smooth and rough endoplasmic reticulum and plastids were found to be predominant in the epithelial cells of the secretory cavities and canals of C. trapezifolia. Such features testify the quantities of oleoresin found in the lumen and phenolic compounds in the epithelial cell cytoplasm of these glands. Other studies employing techniques such as correlative light electron microscopy could show the vesicle traffic and the compartmentalization of the produced substances in such glands.; FAPESP [2008/55434-7]; CAPES; CNPq [301960/2009-7]

Caracterização da estrutura anatômica do lenho, dos anéis de crescimento e dos canais de resina de árvores de Pinus caribaea var. hondurensis Barr. et Golf.; Characterization of the anatomical structure of the wood, the growth rings and the resin ducts in Pinus caribaea var. hondurensis Barr. et Golf.

Ferreira, Angel Thiane Boschiero
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 16/04/2009 PT
Relevância na Pesquisa
56.85%
As pesquisas com resinagem de árvores de espécies de pinus têm mostrado o efeito de fatores que afetam a produção e a qualidade da resina, relacionado com as espécies, variabilidade genética, taxa de crescimento, idade, manejo florestal, etc. As práticas de extração da goma-resina, a concentração, freqüência da aplicação de estimulantes químicos, época de abertura dos painéis, etc., têm sido, da mesma forma, analisadas. No entanto, há necessidade do desenvolvimento de pesquisas direcionadas ao estudo da formação e da estrutura do lenho e dos canais de resina das árvores de pinus. Pelo exposto, o presente trabalho teve como objetivos a caracterização da estrutura anatômica do lenho, dos anéis de crescimento e dos canais de resina, através de metodologias de histologia e de densitometria de raios X, de amostras de árvores de Pinus caribaea var. hondurensis resinadas e não resinadas, de três classes de diâmetro. Árvores de pinus, de plantação florestal instalada em 1969, na Estação Ecológica Experimental de Itirapina, do Instituto Florestal do Estado de São Paulo, foram mensuradas e estratificadas em três classes de diâmetro do tronco. As árvores de pinus têm sido resinadas desde 2004, com a abertura de dois painéis simultâneos e opostos. Sessenta amostras do lenho das árvores de pinus foram extraídas do tronco das árvores através de método não destrutivo e...

Anatomy and ontogeny of the pericarp of Pterodon emarginatus Vogel (Fabaceae, Faboideae), with emphasis on secretory ducts

Paiva, Élder A.S.; Oliveira, Denise M.T.; Machado, Silvia R.
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: 455-465
ENG
Relevância na Pesquisa
36.41%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Processo FAPESP: 00/12469-3; Interpretações discrepantes e incompletas têm sido conferidas ao fruto de Pterodon, especialmente no que tange à determinação estrutural da porção pericárpica que acompanha a semente na dispersão. Assim, com o objetivo de dirimir tais dúvidas e analisar a organização ultra-estrutural das estruturas secretoras presentes no diásporo de Pterodon emarginatus, realizaram-se estudos convencionais aos microscópios de luz e eletrônico de transmissão. Nas fases iniciais de desenvolvimento do fruto, prevalecem divisões celulares; pela ação do meristema subadaxial e do adaxial, formam-se, respectivamente, o mesocarpo interno fibroso e o endocarpo composto por epiderme multisseriada. No mesocarpo mediano, entre os feixes vasculares laterais, diferenciam-se numerosos ductos secretores lisígenos. Após a lise das células centrais e formação do lume, os ductos apresentam epitélio secretor uniestratificado, com células densas; gotas de óleo são observadas no epitélio secretor e tecido subjacente. Na maturidade, o exocarpo unisseriado e o mesocarpo externo...

Anatomy and ontogeny of the pericarp of Pterodon emarginatus Vogel (Fabaceae, Faboideae), with emphasis on secretory ducts

Paiva,Élder A.S.; Oliveira,Denise M.T.; Machado,Silvia R.
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2008 EN
Relevância na Pesquisa
36.41%
Discrepant and incomplete interpretations of fruits of Pterodon have been published, especially on the structural interpretation of the pericarp portion that remain attached to the seed upon dispersal. The present work clarified these doubts and analyzed ultrastructural aspects of the Pterodon emarginatus diaspores using light and transmission electron microscopes. Cell divisions are prevalent among the initial phases of development, and the subadaxial and adaxial meristems form the fibrous inner mesocarp and the endocarp composed of multi-seriate epidermis, respectively. At the median mesocarp, numerous secretory ducts differentiate between the lateral bundles, by lytic process. After lysis of the central cells and the formation of the lumen, the ducts show unistratified secretory epithelium with dense cells; oil droplets are observed on the secretory epithelium and the subadjacent tissues. At maturity, the uniseriate exocarp and the outer mesocarp slough off in an irregular fashion, leaving the diaspore composed of a papery and brittle wing linked to a seed chamber that includes the median mesocarp composed of lignified cells, bordering vascular bundles and many secretory ducts whose epithelial cells develop large vacuoles that accumulate oleoresins. The Pterodon emarginatus fruit is a cryptosamara.

Seasonality and chemical elicitation of defense oleoresin production in field-grown slash pine under subtropical climate

Rodrigues-Corrêa,Kelly Cristine da Silva; Fett-Neto,Arthur Germano
Fonte: Sociedade Brasileira de Fisiologia Vegetal Publicador: Sociedade Brasileira de Fisiologia Vegetal
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
36.21%
Oleoresin is a key defense strategy of advanced gymnosperms, based on the combination of a complex anatomical structure of resin ducts and elaborate terpene biochemistry. Given the vast array of oleoresin economic applications in the chemical, pharmaceutical, agrochemical, and biofuel industries, translating factors that regulate terpene biosynthesis into higher oleoresin yield is a challenge for the forestry industry. Field tests with approximately 3,500 28-year-old slash pine (Pinus elliottii Engelm. var. elliottii) trees were carried out from 2005 to 2008, under the subtropical climate of Southern Brazil, in order to examine the seasonal profile of oleoresin production stimulation in response to different chemical adjuvants, after mechanical injury. Yields of trees treated with oleoresin-inducing pastes containing alternative adjuvants were compared to the standard commercial one used on an industrial scale (based on the ethylene-releasing compound - 2-chloroethylphosphonic acid - CEPA). Significant increases in pine oleoresin yield were observed by modulating its biosynthesis and using chemical stimulants affecting defense responses (benzoic acid, used in addition to CEPA) and biosynthetic enzymes (metal cofactors of terpene synthases...

Methyl Jasmonate Induces Traumatic Resin Ducts, Terpenoid Resin Biosynthesis, and Terpenoid Accumulation in Developing Xylem of Norway Spruce Stems1

Martin, Diane; Tholl, Dorothea; Gershenzon, Jonathan; Bohlmann, Jörg
Fonte: American Society of Plant Physiologists Publicador: American Society of Plant Physiologists
Tipo: Artigo de Revista Científica
Publicado em /07/2002 EN
Relevância na Pesquisa
46.85%
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.

Insect Attack and Wounding Induce Traumatic Resin Duct Development and Gene Expression of (—)-Pinene Synthase in Sitka Spruce1

McKay, S. Ashley Byun; Hunter, William L.; Godard, Kimberley-Ann; Wang, Shawn X.; Martin, Diane M.; Bohlmann, Jörg; Plant, Aine L.
Fonte: The American Society for Plant Biologists Publicador: The American Society for Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /09/2003 EN
Relevância na Pesquisa
36.21%
Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka spruce after insect attack.

Methyl Jasmonate-Induced Ethylene Production Is Responsible for Conifer Phloem Defense Responses and Reprogramming of Stem Cambial Zone for Traumatic Resin Duct Formation

Hudgins, J.W.; Franceschi, Vincent R.
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /08/2004 EN
Relevância na Pesquisa
36.43%
Conifer stem pest resistance includes constitutive defenses that discourage invasion and inducible defenses, including phenolic and terpenoid resin synthesis. Recently, methyl jasmonate (MJ) was shown to induce conifer resin and phenolic defenses; however, it is not known if MJ is the direct effector or if there is a downstream signal. Exogenous applications of MJ, methyl salicylate, and ethylene were used to assess inducible defense signaling mechanisms in conifer stems. MJ and ethylene but not methyl salicylate caused enhanced phenolic synthesis in polyphenolic parenchyma cells, early sclereid lignification, and reprogramming of the cambial zone to form traumatic resin ducts in Pseudotsuga menziesii and Sequoiadendron giganteum. Similar responses in internodes above and below treated internodes indicate transport of a signal giving a systemic response. Studies focusing on P. menziesii showed MJ induced ethylene production earlier and 77-fold higher than wounding. Ethylene production was also induced in internodes above the MJ-treated internode. Pretreatment of P. menziesii stems with the ethylene response inhibitor 1-methylcyclopropene inhibited MJ and wound responses. Wounding increased 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase protein...

Wound-Induced Terpene Synthase Gene Expression in Sitka Spruce That Exhibit Resistance or Susceptibility to Attack by the White Pine Weevil1[W]

Byun-McKay, Ashley; Godard, Kimberley-Ann; Toudefallah, Morteza; Martin, Diane M.; Alfaro, Rene; King, John; Bohlmann, Joerg; Plant, Aine L.
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /03/2006 EN
Relevância na Pesquisa
26.21%
We analyzed the expression pattern of various terpene synthase (TPS) genes in response to a wounding injury applied to the apical leader of Sitka spruce (Picea sitchensis Bong. Carr.) genotypes known to be resistant (R) or susceptible (S) to white pine weevil (Pissodes strobi Peck.) attack. The purpose was to test if differences in constitutive or wound-induced TPS expression can be associated with established weevil resistance. All wounding treatments were conducted on 9-year-old R and S trees growing under natural field conditions within the range of variation for weevil R and S genotypes. Representative cDNAs of the monoterpene synthase (mono-TPS), sesquiterpene synthase (sesqui-TPS), and diterpene synthase (di-TPS) classes were isolated from Sitka spruce to assess TPS transcript levels. Based on amino acid sequence similarity, the cDNAs resemble Norway spruce (Picea abies) (−)-linalool synthase (mono-TPS; PsTPS-Linl) and levopimaradiene/abietadiene synthase (di-TPS; PsTPS-LASl), and grand fir (Abies grandis) δ-selinene synthase (sesqui-TPS; PsTPS-Sell). One other mono-TPS was functionally identified as (−)-limonene synthase (PsTPS-Lim). No significant difference in constitutive expression levels for these TPSs was detected between R and S trees. However...

A Bifunctional Geranyl and Geranylgeranyl Diphosphate Synthase Is Involved in Terpene Oleoresin Formation in Picea abies1[W][OA]

Schmidt, Axel; Wächtler, Betty; Temp, Ulrike; Krekling, Trygve; Séguin, Armand; Gershenzon, Jonathan
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /02/2010 EN
Relevância na Pesquisa
26.41%
The conifer Picea abies (Norway spruce) defends itself against herbivores and pathogens with a terpenoid-based oleoresin composed chiefly of monoterpenes (C10) and diterpenes (C20). An important group of enzymes in oleoresin biosynthesis are the short-chain isoprenyl diphosphate synthases that produce geranyl diphosphate (C10), farnesyl diphosphate (C15), and geranylgeranyl diphosphate (C20) as precursors of different terpenoid classes. We isolated a gene from P. abies via a homology-based polymerase chain reaction approach that encodes a short-chain isoprenyl diphosphate synthase making an unusual mixture of two products, geranyl diphosphate (C10) and geranylgeranyl diphosphate (C20). This bifunctionality was confirmed by expression in both prokaryotic (Escherichia coli) and eukaryotic (P. abies embryogenic tissue) hosts. Thus, this isoprenyl diphosphate synthase, designated PaIDS1, could contribute to the biosynthesis of both major terpene types in P. abies oleoresin. In saplings, PaIDS1 transcript was restricted to wood and bark, and transcript level increased dramatically after methyl jasmonate treatment, which induces the formation of new (traumatic) resin ducts. Polyclonal antibodies localized the PaIDS1 protein to the epithelial cells surrounding the traumatic resin ducts. PaIDS1 has a close phylogenetic relationship to single-product conifer geranyl diphosphate and geranylgeranyl diphosphate synthases. Its catalytic properties and reaction mechanism resemble those of conifer geranylgeranyl diphosphate synthases...

Notch signaling regulates formation of the three-dimensional architecture of intrahepatic bile ducts in mice

Sparks, Erin E.; Huppert, Kari A.; Brown, Melanie A.; Washington, M. Kay; Huppert, Stacey S.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/2010 EN
Relevância na Pesquisa
26.23%
Alagille syndrome, a chronic hepatobiliary disease, is characterized by paucity of intrahepatic bile ducts (IHBDs). To determine the impact of Notch signaling specifically on IHBD arborization we studied the influence of both chronic gain and loss of Notch function on the intact three-dimensional IHBD structure using a series of mutant mouse models and a resin casting method. Impaired Notch signaling in bi-potential hepatoblast progenitor cells (BHPCs) dose-dependently decreased the density of peripheral IHBDs, whereas activation of Notch1 results in an increased density of peripheral IHBDs. While Notch2 has a dominant role in IHBD formation there is also a redundant role for other Notch receptors in determining the density of peripheral IHBDs. Since changes in IHBD density do not appear to be due to changes in cellular proliferation of bile duct progenitors, we suggest that Notch plays a permissive role in cooperation with other factors to influence lineage decisions of BHPCs and sustain peripheral IHBDs.

Induction of isoprenyl diphosphate synthases, plant hormones and defense signalling genes correlates with traumatic resin duct formation in Norway spruce (Picea abies)

Schmidt, Axel; Nagel, Raimund; Krekling, Trygve; Christiansen, Erik; Gershenzon, Jonathan; Krokene, Paal
Fonte: Springer Netherlands Publicador: Springer Netherlands
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.87%
Norway spruce (Picea abies) defends itself against herbivores and pathogens by formation of traumatic resin ducts filled with terpenoid-based oleoresin. An important group of enzymes in terpenoid biosynthesis are the short-chain isoprenyl diphosphate synthases which produce geranyl diphosphate (C10), farnesyl diphosphate (C15), and geranylgeranyl diphosphate (C20) as precursors of monoterpenes, sesquiterpenes, and diterpene resin acids, respectively. After treatment with methyl jasmonate (MJ) we investigated the expression of all isoprenyl diphosphate synthase genes characterized to date from Norway spruce and correlated this with formation of traumatic resin ducts and terpene accumulation. Formation of traumatic resin ducts correlated with higher amounts of monoterpenes, sesquiterpenes and diterpene resin acids and an upregulation of isoprenyl diphosphate synthase genes producing geranyl diphosphate or geranylgeranyl diphosphate. Among defense hormones, jasmonate and jasmonate-isoleucine conjugate accumulated to higher levels in trees with extensive traumatic resin duct formation, whereas salicylate did not. Jasmonate and ethylene are likely to both be involved in formation of traumatic resin ducts based on elevated transcripts of genes encoding lipoxygenase and 1-aminocyclopropane-1-carboxylic acid oxidase associated with resin duct formation. Other genes involved in defense signalling in other systems...

Evolution of Diterpene Metabolism: Sitka Spruce CYP720B4 Catalyzes Multiple Oxidations in Resin Acid Biosynthesis of Conifer Defense against Insects1[C][W][OA]

Hamberger, Björn; Ohnishi, Toshiyuki; Hamberger, Britta; Séguin, Armand; Bohlmann, Jörg
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.3%
Diterpene resin acids (DRAs) are specialized (secondary) metabolites of the oleoresin defense of conifers produced by diterpene synthases and cytochrome P450s of the CYP720B family. The evolution of DRA metabolism shares common origins with the biosynthesis of ent-kaurenoic acid, which is highly conserved in general (primary) metabolism of gibberellin biosynthesis. Transcriptome mining in species of spruce (Picea) and pine (Pinus) revealed CYP720Bs of four distinct clades. We cloned a comprehensive set of 12 different Sitka spruce (Picea sitchensis) CYP720Bs as full-length cDNAs. Spatial expression profiles, methyl jasmonate induction, and transcript enrichment in terpenoid-producing resin ducts suggested a role of CYP720B4 in DRA biosynthesis. CYP720B4 was characterized as a multisubstrate, multifunctional enzyme by the formation of oxygenated diterpenoids in metabolically engineered yeast, yeast in vivo transformation of diterpene substrates, in vitro assays with CYP720B4 protein produced in Escherichia coli, and alteration of DRA profiles in RNA interference-suppressed spruce seedlings. CYP720B4 was active with 24 different diterpenoid substrates, catalyzing consecutive C-18 oxidations in the biosynthesis of an array of diterpene alcohols...

Pharmacognostic Studies of Thuja Occidentalis Linn. – A Good remedy for warts & tumours, used in Homeopathy

Rajatrashmi, ; Sarkar, Manisha; Vikramaditya,
Fonte: Medknow Publications & Media Pvt Ltd Publicador: Medknow Publications & Media Pvt Ltd
Tipo: Artigo de Revista Científica
Publicado em //1999 EN
Relevância na Pesquisa
26.23%
Thuja occidentalis Linn. (Family cupressaceae), commonly known as American Arbore Vitae, is an evergreen tree and native of North America. Leaves & twigs, which contains essential oil, condylomatous growth, spongy tumours, warts, ill effects of vaccination etc. Twigs fan-shaped; leaves ovate, obtuse, having resin ducts & parenchymatous mesophyll; stem shows resins ducts in parenchymatous cortex and alternate bands of phloem parenchyma & phloem fibres. TLC of alcoholic extract in chloroform: Methanol (9:1) shows 8 spots under UV light, and UV absorbance shows peak at 260nm.

Comparative morpho-anatomical studies of the lesions caused by citrus leprosis virus on sweet orange

MARQUES, J. P. R.; KITAJIMA, E. W.; FREITAS-ASTUA, J.; APPEZZATO-DA-GLORIA, B.
Fonte: Anais da Academia Brasileira de Ciências, v.82, n. 2, p. 501-511, 2010. Publicador: Anais da Academia Brasileira de Ciências, v.82, n. 2, p. 501-511, 2010.
Tipo: Artigo em periódico indexado (ALICE)
PT_BR
Relevância na Pesquisa
26.41%
The leprosis disease shows a viral etiology and the citrus leprosis virus is considered its etiologic agent. The disease may show two types of cytopatologic symptom caused by two virus: nuclear (CiLV-N) and cytoplasmic (CiLV-C) types. The aim of this study was to compare the morpho-anatomical differences in the lesions caused by leprosis virus-cytoplasmic and nuclear types in Citrus sinensis (L.) Osbeck ?Pêra?. Leaf and fruit lesions were collected in Piracicaba/São Paulo (cytoplasmic type) and Monte Alegre do Sul/São Paulo and Amparo/São Paulo (nuclear type). The lesions were photographed and then fixed in Karnovsky solution, dehydrated in a graded ethylic series, embedded in hydroxy-ethyl methacrylate resin (Leica Historesin), sectioned (5?m thick), stained and mounted in synthetic resin. The digital images were acquired in a microscope with digital video camera. Leaf and fruit lesions caused by the two viruses were morphologically distinct. Only the lesion caused by CiLV-N virus presented three well-defined regions. In both lesions there was the accumulation of lipidic substances in necrotic areas that were surrounded by cells with amorphous or droplets protein. Only leaf and fruit lesions caused by CiLV-N virus exhibited traumatic gum ducts in the vascular bundles.; 2010; Disponivel em: .Acesso em: 18 out. 2010.

Comparative leaf anatomy of some species of Abies and Picea (Pinaceae)

Ghimire,Balkrishna; Lee,Chunghee; Yang,Jongcheol; Heo,Kweon
Fonte: Sociedade Botânica do Brasil Publicador: Sociedade Botânica do Brasil
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2015 EN
Relevância na Pesquisa
26.41%
ABSTRACTA number of conifer species are still lacking anatomical data, which is significant because morphological and anatomical data are essential for systematic study. Leaf anatomy was studied in selected species of Abiesand Piceausing light and scanning electron microscopy. Both genera were found to have typical coniferous and highly xerophytic leaves with sunken stomata and an epidermis covered by a thick cuticle. In the genus Abies, species can be differentiated by the nature of the lignified hypodermis and the number and position of resin ducts. Abies firma and A. holophylla have a continuous hypodermis whereas in A. koreana and A. nephrolepis the hypodermis is discontinuous and represented by isolated cells or groups of four or five cells. On the other hand, in Picea leaf shape, stomata arrangement, and number, position, and nature of resin ducts are the key features for species differentiation. Picea jezoensis has a flattened leaf with stomata distributed on the adaxial surface whereas P. abies and P. koraiensis have a rectangular leaf with stomata found on surfaces.

Comparative morpho-anatomical studies of the lesions caused by citrus leprosis virus on sweet orange

Marques,João P.R.; Kitajima,Elliot W.; Freitas-Astúa,Juliana; Appezzato-da-Glória,Beatriz
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2010 EN
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26.41%
The leprosis disease shows a viral etiology and the citrus leprosis virus is considered its etiologic agent. The disease may show two types of cytopatologic symptom caused by two virus: nuclear (CiLV-N) and cytoplasmic (CiLV-C) types. The aim of this study was to compare the morpho-anatomical differences in the lesions caused by leprosis virus-cytoplasmic and nuclear types in Citrus sinensis (L.) Osbeck 'Pêra'. Leaf and fruit lesions were collected in Piracicaba/São Paulo (cytoplasmic type) and Monte Alegre do Sul/São Paulo and Amparo/São Paulo (nuclear type). The lesions were photographed and then fixed in Karnovsky solution, dehydrated in a graded ethylic series, embedded in hydroxy-ethyl methacrylate resin (Leica Historesin), sectioned (5 μm thick), stained and mounted in synthetic resin. The digital images were acquired in a microscope with digital video camera. Leaf and fruit lesions caused by the two viruses were morphologically distinct. Only the lesion caused by CiLV-N virus presented three well-defined regions. In both lesions there was the accumulation of lipidic substances in necrotic areas that were surrounded by cells with amorphous or droplets protein. Only leaf and fruit lesions caused by CiLV-N virus exhibited traumatic gum ducts in the vascular bundles.

Resin duct density and size predicts mortality in ponderosa pine trees of Northern Arizona

Jeffrey M. Kane; Thomas E. Kolb
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
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In the presence of herbivores, plants must allocate a portion of their accumulated carbon towards defense to survive. For example, trees susceptible to bark beetle attack are primarily reliant on resin production for protection. Tree mortality may be reflected by individual differences in the ability of plants to produce defensive structures and compounds. We compared the radial growth rates, resin duct production, density, and size between living and dead ponderosa pine trees in northern Arizona using standard dendrochronology techniques. As a result, we found four main findings: 1) living ponderosa pines had 33% more resin ducts than dead pines (t = 2.97, P < 0.003); 2) resin duct size was 13% larger in living than in dead pines (t = 3.00, P < 0.003); 3) both resin duct density and size were predictive of mortality (Wald’s Z = 1.9, P < 0.05); and 4) resin duct production was positively correlated with growth rate. Our results suggest dendrochronology can quantify defense structure production and predict tree mortality in ponderosa pine forests in northern Arizona.