962 resultados para Anatomy of plants
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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In this article we present the plants used for the treatment of malaria and associated symptoms in Santa Isabel do Rio Negro in the Brazilian Amazon. The region has important biological and cultural diversities including more than twenty indigenous ethnic groups and a strong history in traditional medicine. The aims of this study are to survey information in the Baniwa, Baré, Desana, Piratapuia, Tariana, Tukano, Tuyuca, Yanomami ethnic communities and among caboclos (mixed-ethnicity) on: a) plant species used for the treatment of malaria and associated symptoms; b) dosage forms and c) distribution of these anti-malarial plants in the Amazon. Information was obtained through classical ethnobotanical and ethnopharmacological methods from interviews with 146 informants in Santa Isabel municipality on the upper Negro River, Brazil. Fifty-five mainly native neotropical plant species from 34 families were in use. The detailed uses of these plants were documented. The result was 187 records (64.4%) of plants for the specific treatment of malaria, 51 records (17.5%) of plants used in the treatment of liver problems and 28 records (9.6%) of plants used in the control of fevers associated with malaria. Other uses described were blood fortification ('dar sangue'), headache and prophylaxis. Most of the therapeutic preparations were decoctions and infusions based on stem bark, root bark and leaves. These were administered by mouth. In some cases, remedies were prepared with up to three different plant species. Also, plants were used together with other ingredients such as insects, mammals, gunpowder and milk. This is the first study on the anti-malarial plants from this region of the Amazon. Aspidosperma spp. and Ampelozizyphus amazonicus Ducke were the most cited species in the communities surveyed. These species have experimental proof supporting their anti-malarial efficacy. The dosage of the therapeutic preparations depends on the kind of plant, quantity of plant material available, the patient's age (children and adults) and the local expert. The treatment time varies from a single dose to up to several weeks. Most anti-malarial plants are domesticated or grow spontaneously. They are grown in home gardens, open areas near the communities, clearings and secondary forests, and wild species grow in areas of seasonally flooded wetlands and terra firme (solid ground) forest, in some cases in locations that are hard to access. Traditional knowledge of plants was found to be falling into disuse presumably as a consequence of the local official health services that treat malaria in the communities using commercial drugs. Despite this, some species are used in the prevention of this disease and also in the recovery after using conventional anti-malarial drugs.
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The greenhouse production associated with the fertigation management, have established in Brazil as economical alternative for several horticultural species. With this strategy this study had as aim to evaluate possible impacts in the metabolism of plants of bell pepper (Capsicum annuum L.; cv Elisa) in response to the increase of mineral concentration in the soil. During the experiments, the some nutrient concentrations were altered, to obtain high values of electric conductivity (EC) in the soil solution. The EC values commonly observed in the traditional fertigation system were adopted, as control. It was also verified the possibility of reduction of the mineral stress impact by the application of organic matter in the soil. Parameters of the antioxidative response system, as the superoxide dismutase (SOD) and catalase enzyme activities besides the proline content were evaluated to measure the extension of the saline stress and their effects on the plants. The increase of EC of the soil induced to the increase of the proline concentration and the SOD activity. Unexpectedly, it was verified that the saline stress inhibited the activity of the enzyme catalase. It was also concluded that the monitoring of EC of the soil is an indispensable tool to reach success in the fertigation system and that the study of the activity of the enzymes of the antioxidative response system, and the proline contents can be assumed as indicators in of the levels of stress in bell pepper plants (Capsicum annuum L.; cv Elisa).
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Recently, molecular analysis caused the South American Viguiera Kunth species to be transferred to Aldama La Llave. However, the circumscription has not been established for certain of the South American species, including Aldama filifolia (Sch. Bip. ex Baker) E. E. Schill. & Panero, A. linearifolia (Chodat) E. E. Schill. & Panero and A. trichophylla (Dusen) Magenta (comb. nov.), which had previously been treated as synonyms because of their high similarity. Therefore, the present study aimed to evaluate the anatomy of the aerial organs, and the yield and chemical composition of the essential oils from these three species, to determine the differences among them and thereby assist in species distinction. The anatomical analysis identified characteristics unique to each species, which are primarily related to the position and occurrence of secretory structures. Histochemical analysis demonstrated that the glandular trichomes and the canals secrete lipophilic substances, which are characterised by the presence of essential oils. The analysis of these essential oils identified monoterpenes as their major constituent and allowed for the recognition of chemical markers for each species. The anatomical and chemical characteristics identified by the present study confirmed that the studied samples belong to three distinct taxa.
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Mine tailings can be rich in sulphide minerals and may form acid mine drainage (AMD) through reaction with atmospheric oxygen and water. AMD contains elevated levels of metals and arsenic (As) that could be harmful to animals and plants. An oxygen-consuming layer of organic material and plants on top of water-covered tailings would probably reduce oxygen penetration into the tailings and thus reduce the formation of AMD. However, wetland plants have the ability to release oxygen through the roots and could thereby increase the solubility of metals and As. These elements are released into the drainage water, taken up and accumulated in the plant roots, or translocated to the shoots. The aim was to examine the effects of plant establishment on water-covered mine tailings by answering following questions: A) Is plant establishment on water-covered mine tailings possible? B) What are the metal and As uptake and translocation properties of these plants? C) How do plants affect metal and As release from mine tailings, and which are the mechanisms involved? Carex rostrata Stokes, Eriophorum angustifolium Honck., E. scheuchzeri Hoppe, Phragmites australis (Cav.) Steud., Salix phylicifolia L. and S. borealis Fr. were used as test plants. Influences of plants on the release of As, Cd, Cu, Pb, Zn and in some cases Fe in the drainage water, and plant element uptake were studied in greenhouse experiments and in the field. The results obtained demonstrate that plant establishment are possible on water-covered unweathered mine tailings, and a suitable amendment was found to be sewage sludge. On acidic, weathered tailings, a pH increasing substance such as ashes should be added to improve plant establishment. The metal and As concentrations of the plant tissue were found to be generally higher in roots than in shoots. The uptake was dependent on the metal and As concentrations of the tailings and the release of organic acids from plant roots may have influenced the uptake. The metal release from tailings into the drainage water caused by E. angustifolium was found to depend greatly on the age and chemical properties of the tailings. However, no effects of E. angustifolium on As release was found. Water from old sulphide-, metal- and As-rich tailings with low buffering capacity were positively affected by E. angustifolium by causing higher pH and lower metal concentrations. In tailings with relatively low sulphide, metal and As contents combined with a low buffering capacity, plants had the opposite impact, i.e. a reduction in pH and elevated metal levels of the drainage water. The total release of metal and As from the tailings, i.e. drainage water together with the contents in shoots and roots, was found to be similar for C. rostrata, E. angustifolium and P. australis, except for Fe and As, where the release was highest for P. australis. The differences in metal and As release from mine tailings were mainly found to be due to the release of O2 from the roots, which changes the redox potential. Release of organic acids from the roots slightly decreased the pH, although did not have any particular influence on the release of metal and As. In conclusion, as shown here, phytostabilisation may be a successful technique for remediation of mine tailings with high element and sulphide levels, and low buffering capacity.
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Mercury (Hg) pollution is a global environmental problem. Numerous Hg-contaminated sites exist in the world and new techniques for remediation are urgently needed. Phytoremediation, use of plants to remove pollutants from the environment or to render them harmless, is considered as an environment-friendly method to remediate contaminated soil in-situ and has been applied for some other heavy metals. Whether this approach is suitable for remediation of Hg-contaminated soil is, however, an open question. The aim of this thesis was to study the fate of Hg in terrestrial plants (particularly the high biomass producing willow, Salix spp.) and thus to clarify the potential use of plants to remediate Hg-contaminated soils. Plants used for phytoremediation of Hg must tolerate Hg. A large variation (up to 30-fold difference) was detected among the six investigated clones of willow in their sensitivity to Hg as reflected in their empirical toxicity threshold (TT95b), the maximum unit toxicity (UTmax) and EC50 levels. This gives us a possibility to select Hg-tolerant willow clones to successfully grow in Hgcontaminated soils for phytoremediation. Release of Hg into air by plants is a concern when using phytoremediation in practice. No evidence was found in this study that Hg was released to the air via shoots of willow, garden pea (Pisum sativum L. cv Faenomen), spring wheat (Triticum aestivum L. cv Dragon), sugar beet (Beta vulgaris L. cv Monohill), oil-seed rape (Brassica napus L. cv Paroll) and white clover (Trifolium repens L.). Thus, we conclude that the Hg burden to the atmosphere via phytoremediation is not increased. Phytoremediation processes are based on the ability of plant roots to accumulate Hg and to translocate it to the shoots. Willow roots were shown to be able to efficiently accumulate Hg in hydroponics, however, no variation in the ability to accumulate was found among the eight willow clones using CVAAS to analyze Hg content in plants. The majority of the Hg accumulated remained in the roots and only 0.5-0.6% of the Hg accumulation was translocated to the shoots. Similar results were found for the five common cultivated plant species mentioned above. Moreover, the accumulation of Hg in willow was higher when being cultivated in methyl-Hg solution than in inorganic Hg solution, whereas the translocation of Hg to the shoots did not differ. The low bioavailability of Hg in contaminated soil is a restricting factor for the phytoextraction of Hg. A selected tolerant willow clone was used to study whether iodide addition could increase the plant-accumulation of Hg from contaminated soil. Both pot tests and field trials were carried out. Potassium iodide (KI) addition was found to mobilize Hg in contaminated soil and thus increase the bioavailability of Hg in soils. Addition of KI (0.2–1 mM) increased the Hg concentrations up to about 5, 3 and 8 times in the leaves, branches and roots, respectively. However, too high concentrations of KI were toxic to plants. As the majority of the Hg accumulated in the roots, it might be unrealistic to use willow for phytoextraction of Hg in practice, even though iodide could enhance the phytoextraction efficiency. In order to study the effect of willow on various soil fractions of Hg-contaminated soil, a 5-step sequential soil extraction method was used. Both the largest Hg-contaminated fractions, i.e. the Hg bound to residual organic matter (53%) and sulphides (43%), and the residual fraction (2.5%), were found to remain stable during cultivations of willow. The exchangeable Hg (0.1%) and the Hg bound to humic and fulvic acids (1.1%) decreased in the rhizospheric soil, whereas the plant accumulation of Hg increased with the cultivation time. The sum of the decrease of the two Hg fractions in soils was approximately equal to the amount of the Hg accumulated in plants. Consequently, plants may be suitable for phytostabilization of aged Hg-contaminated soil, in which root systems trap the bioavailable Hg and reduce the leakage of Hg from contaminated soils.
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The development and the growth of plants is strongly affected by the interactions between roots, rootrnassociated organisms and rhizosphere communities. Methods to assess such interactions are hardly torndevelop particularly in perennial and woody plants, due to their complex root system structure and theirrntemporal change in physiology patterns. In this respect, grape root systems are not investigated veryrnwell. The aim of the present work was the development of a method to assess and predict interactionsrnat the root system of rootstocks (Vitis berlandieri x Vitis riparia) in field. To achieve this aim, grapernphylloxera (Daktulosphaira vitifoliae Fitch, Hemiptera, Aphidoidea) was used as a graperoot parasitizingrnmodel.rnTo develop the methodical approach, a longt-term trial (2006-2009) was arranged on a commercial usedrnvineyard in Geisenheim/Rheingau. All 2 to 8 weeks the top most 20 cm of soil under the foliage wallrnwere investigated and root material was extracted (n=8-10). To include temporal, spatial and cultivarrnspecific root system dynamics, the extracted root material was analyzed digitally on the morphologicalrnproperties. The grape phylloxera population was quantified and characterized visually on base of theirrnlarvalstages (oviparous, non oviparous and winged preliminary stages). Infection patches (nodosities)rnwere characterized visually as well, partly supported by digital root color analyses. Due to the knownrneffects of fungal endophytes on the vitality of grape phylloxera infested grapevines, fungal endophytesrnwere isolated from nodosity and root tissue and characterized (morphotypes) afterwards. Further abioticrnand biotic soil conditions of the vineyards were assessed. The temporal, spatial and cultivar specificrnsensitivity of single parameters were analyzed by omnibus tests (ANOVAs) and adjacent post-hoc tests.rnThe relations between different parameters were analyzed by multiple regression models.rnQuantitative parameters to assess the degeneration of nodosity, the development nodosity attachedrnroots and to differentiate between nodosities and other root swellings in field were developed. Significantrndifferences were shown between root dynamic including parameters and root dynamic ignoringrnparameters. Regarding the description of grape phylloxera population and root system dynamic, thernmethod showed a high temporal, spatial and cultivar specific sensitivity. Further, specific differencesrncould be shown in the frequency of endophyte morphotypes between root and nodosity tissue as wellrnas between cultivars. Degeneration of nodosities as well as nodosity occupation rates could be relatedrnto the calculated abundances of grape phylloxera population. Further ecological questions consideringrngrape root development (e.g. relation between moisture and root development) and grape phylloxerarnpopulation development (e.g. relation between temperature and population structure) could be answeredrnfor field conditions.rnGenerally, the presented work provides an approach to evaluate vitality of grape root systems. Thisrnapproach can be useful, considering the development of control strategies against soilborne pests inrnviticulture (e.g. grape phylloxera, Sorospheara viticola, Roesleria subterranea (Weinm.) Redhaed) as well as considering the evaluation of integrated management systems in viticulture.
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Gross dissection for demonstrating anatomy of the human pelvis has traditionally involved one of two approaches, each with advantages and disadvantages. Classic hemisection in the median plane through the pelvic ring transects the visceral organs but maintains two symmetric pelvic halves. An alternative paramedial transection compromises one side of the bony pelvis but leaves the internal organs intact. The authors propose a modified technique that combines advantages of both classical dissections. This novel approach involves dividing the pubic symphysis and sacrum in the median plane after shifting all internal organs to one side. The hemipelvis without internal organs is immediately available for further dissection of the lower limb. The hemipelvis with intact internal organs is ideal for showing the complex spatial relationships of the pelvic organs and vessels relative to the intact pelvic floor.
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BACKGROUND: Current concepts of catheter ablation for atrial fibrillation (AF) commonly use three-dimensional (3D) reconstructions of the left atrium (LA) for orientation, catheter navigation, and ablation line placement. OBJECTIVES: The purpose of this study was to compare the 3D electroanatomic reconstruction (Carto) of the LA, pulmonary veins (PVs), and esophagus with the true anatomy displayed on multislice computed tomography (CT). METHODS: In this prospective study, 100 patients undergoing AF catheter ablation underwent contrast-enhanced spiral CT scan with barium swallow and subsequent multiplanar and 3D reconstructions. Using Carto, circumferential plus linear LA lesions were placed. The esophagus was tagged and integrated into the Carto map. RESULTS: Compared with the true anatomy on CT, the electroanatomic reconstruction accurately displayed the true distance between the lower PVs; the distances between left upper PV, left lower PV, right lower PV, and center of the esophagus; the longitudinal diameter of the encircling line around the funnel of the left PVs; and the length of the mitral isthmus line. Only the distances between the upper PVs, the distance between the right upper PV and esophagus, and the diameter of the right encircling line were significantly shorter on the electroanatomic reconstructions. Furthermore, electroanatomic tagging of the esophagus reliably visualized the true anatomic relationship to the LA. On multiple tagging and repeated CT scans, the LA and esophagus showed a stable anatomic relationship, without relevant sideward shifting of the esophagus. CONCLUSION: Electroanatomic reconstruction can display with high accuracy the true 3D anatomy of the LA and PVs in most of the regions of interest for AF catheter ablation. In addition, Carto was able to visualize the true anatomic relationship between the esophagus and LA. Both structures showed a stable anatomic relationship on Carto and CT without relevant sideward shifting of the esophagus.
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The oxygen isotopic composition of precipitation (δ18Oprec) is well known to be a valuable (paleo-)climate proxy. Paleosols and sediments and hemicelluloses therein have the potential to serve as archives recording the isotopic composition of paleoprecipitation. In a companion paper (Zech et al., 2014) we investigated δ18Ohemicellulose values of plants grown under different climatic conditions in a climate chamber experiment. Here we present results of compound-specific δ18O analyses of arabinose, fucose and xylose extracted from modern topsoils (n = 56) along a large humid-arid climate transect in Argentina in order to answer the question whether hemicellulose biomarkers in soils reflect δ18Oprec. The results from the field replications indicate that the homogeneity of topsoils with regard to δ18Ohemicellulose is very high for most of the 20 sampling sites. Standard deviations for the field replications are 1.5‰, 2.2‰ and 1.7‰, for arabinose, fucose and xylose, respectively. Furthermore, all three hemicellulose biomarkers reveal systematic and similar trends along the climate gradient. However, the δ18Ohemicellulose values (mean of the three sugars) do not correlate positively with δ18Oprec (r = −0.54, p < 0.014, n = 20). By using a Péclet-modified Craig-Gordon (PMCG) model it can be shown that the δ18Ohemicellulose values correlate highly significantly with modeled δ18Oleaf water values (r = 0.81, p < 0.001, n = 20). This finding suggests that hemicellulose biomarkers in (paleo-)soils do not simply reflect δ18Oprec but rather δ18Oprec altered by evaporative 18O enrichment of leaf water due to evapotranspiration. According to the modeling results, evaporative 18O enrichment of leaf water is relatively low (∼10‰) in the humid northern part of the Argentinian transect and much higher (up to 19‰) in the arid middle and southern part of the transect. Model sensitivity tests corroborate that changes in relative air humidity exert a dominant control on evaporative 18O enrichment of leaf water and thus δ18Ohemicellulose, whereas the effect of temperature changes is of minor importance. While oxygen exchange and degradation effects seem to be negligible, further factors needing consideration when interpreting δ18Ohemicellulose values obtained from (paleo-)soils are evaporative 18O enrichment of soil water, seasonality effects, wind effects and in case of abundant stem/root-derived organic matter input a partial loss of the evaporative 18O enrichment of leaf water. Overall, our results prove that compound-specific δ18O analyses of hemicellulose biomarkers in soils and sediments are a promising tool for paleoclimate research. However, disentangling the two major factors influencing δ18Ohemicellulose, namely δ18Oprec and relative air humidity controlled evaporative 18O enrichment of leaf water, is challenging based on δ18O analyses alone.
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Metasequoia glyptostroboides is a useful nearest living relative (NLR) of the Eocene fossil Metasequoia. Research on modern Metasequoia might give us some clues about its fossil counterpart. During this study the leaf anatomy of Metasequoia, Glyptostrobus, Sequoia and Taxodium was investigated with light microscopy and transmission electron microscopy. Metasequoia exhibits several characteristics of typical sciaphilic plants, such as slightly arched outer cell walls in the adaxial epidermal cells, strongly arched outer cell walls in the abaxial epidermal cells, mesophyll composed of spongy cells, chloroplasts with well-developed grana not only in mesophyll cells but in both the adaxial and abaxial epidermis. Based on comparison of leaf morphology and anatomy, we conclude that Metasequoia is best adapted to low light intensities, Sequoia and Taxodium are intermediate, and Glyptostrobus is adapted to higher light intensities. The effects of light intensity on mesophyll plastids of Metasequoia leaves were studied with trees grown under different light intensities. Metasequoia had the ability to synthesize chlorophyll under complete darkness and was stressed under high light. These characteristics would provide adaptive advantages for Metasequoia to adapt to low intensity, low angle, polar light at their Eocene high latitude paleoenvironments, particularly during the polar spring when light levels are exceedingly low. It provides evidence to explain why Metasequoia was the dominant tree species in Eocene high latitudes. The thesis is written as an article to be submitted to the American Journal of Botany.
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The development of reliable clonal propagation technologies is a requisite for performing Multi-Varietal Forestry (MVF). Somatic embryogenesis is considered the tissue culture based method more suitable for operational breeding of forest trees. Vegetative propagation is very difficult when tissues are taken from mature donors, making clonal propagation of selected trees almost impossible. We have been able to induce somatic embryogenesis in leaves taken from mature oak trees, including cork oak (Quercus suber). This important species of the Mediterranean ecosystem produces cork regularly, conferring to this species a significant economic value. In a previous paper we reported the establishment of a field trial to compare the growth of plants of somatic origin vs zygotic origin, and somatic plants from mature trees vs somatic plants from juvenile seedlings. For that purpose somatic seedlings were regenerated from five selected cork oak trees and from young plants of their half-sib progenies by somatic embryogenesis. They were planted in the field together with acorn-derived plants of the same families. After the first growth period, seedlings of zygotic origin doubled the height of somatic seedlings, showing somatic plants of adult and juvenile origin similar growth. Here we provide data on height and diameter increases after two additional growth periods. In the second one, growth parameters of zygotic seedlings were also significantly higher than those of somatic ones, but there were not significant differences in height increase between seedlings and somatic plants of mature origin. In the third growth period, height and diameter increases of somatic seedlings cloned from the selected trees did not differ from those of zygotic seedlings, which were still higher than data from plants obtained from somatic embryos from the sexual progeny. Therefore, somatic seedlings from mature origin seem not to be influenced by a possible ageing effect, and plants from somatic embryos tend to minimize the initial advantage of plants from acorns
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In spite of much effort, no one has succeeded in isolating and characterizing the enzyme(s) responsible for synthesis of cellulose, the major cell wall polymer of plants. We have characterized two cotton (Gossypium hirsutum) cDNA clones and identified one rice (Oryza sativa) cDNA that are homologs of the bacterial celA genes that encode the catalytic subunit of cellulose synthase. Three regions in the deduced amino acid sequences of the plant celA gene products are conserved with respect to the proteins encoded by bacterial celA genes. Within these conserved regions, there are four highly conserved subdomains previously suggested to be critical for catalysis and/or binding of the substrate UDP-glucose (UDP-Glc). An overexpressed DNA segment of the cotton celA1 gene encodes a polypeptide fragment that spans these domains and binds UDP-Glc, while a similar fragment having one of these domains deleted does not. The plant celA genes show little homology at the N- and C-terminal regions and also contain two internal insertions of sequence, one conserved and one hypervariable, that are not found in the bacterial gene sequences. Cotton celA1 and celA2 genes are expressed at high levels during active secondary wall cellulose synthesis in developing cotton fibers. Genomic Southern blot analyses in cotton demonstrate that celA forms a small gene family.