348 resultados para Circulation of seeds and propagules
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
(Morpho-anatomical studies of seeds and seedlings of wild indigo, ""anileira"", Indigofera-Leguminosae). The common name ""wild indigo"" specifies Indigofera will L., I. suffruticosa Mill. (legitimate name) and I. truxillensis Kunth (legitimate name) that are very similar due to their external morphology. This work analyzed diagnostic characteristics of seeds and seedlings of these species since such features are widely used in taxonomic approaches within Leguminosae. We studied surface features and morpho-anatomy of seeds and cotyledons with scanning electronic microscopy and light microscopy, and described seedling phases. Although seedlings are similar, seed characteristics (size, shape, surface ornamentation, shape of the hilum and embryo size) and cotyledon characteristics (shape, trichome ornamentation, organization of spongy parenchyma along central veins and metabolite distribution in the tissues) have diagnostic features for the species. I. anil differs from I. suffruticosa in its larger seeds and acuminate-margined cotyledons. I. truxillensis is recognized by its cylindrical seeds and kidney-shaped cotyledons with large oil drops. We assume that the characteristics examined, plus fruit morphology and foliar anatomy suggest that I. anil, I. suffruticosa and I. truxillensis should not be synonymized.
Resumo:
Considering the importance of water content for the conservation and storage of seeds, and the involvement of soluble carbohydrates and lipids for embryo development, a comparative study was carried out among the seeds of Inga vera (ingá), Eugenia uniflora (pitanga), both classified as recalcitrant, and Caesalpinia echinata (brazilwood) and Erythrina speciosa (mulungu), considered as orthodox seeds. Low concentrations of cyclitols (0.3-0.5%), raffinose family oligosaccharides (ca. 0.05%) and unsaturated fatty acids (0-19%) were found in the seeds of ingá and pitanga, while larger amounts of cyclitols (2-3%) and raffinose (4.6-13%) were found in brazilwood and mulungu, respectively. These results, in addition to higher proportions of unsaturated fatty acids (53-71%) in orthodox seeds, suggested that sugars and lipids played important role in water movement, protecting the embryo cell membranes against injuries during dehydration.
Resumo:
The diversity and beneficial characteristics of endophytic microorganisms have been studied in several host plants. However, information regal-ding naturally, occurring seed-associated endophytes and vertical transmission among different life-history stages of hosts is limited. Endophytic bacteria were isolated from seeds and seedlings of 10 Eucalyptus species and two hybrids. The results showed that endophytic bacteria, Such as Bacillus, Enterococcus, Paenibacillus and Methylobacterium, are vertically transferred from seeds to seedlings. In addition, the endophytic bacterium Pantoea agglomerans was tagged with the gfp gene, inoculated into seeds and further reisolated from seedlings. These results suggested it novel approach to change the profile of the plants, where the bacterium is a delivery vehicle for desired traits. This is the first report of an endophytic bacterial community residing in Eucalyptus seeds and the transmission of these bacteria from seeds to seedlings. The bacterial species reported ill this work have been described as providing benefits to host plants. Therefore, we Suggest that endophytic bacteria can be transmitted vertically from seeds to seedlings, assuring the support of the bacterial community in the host plant.
Resumo:
To study and characterize the in vivo effect of the lectin from Luetzelburgia auriculata seed on acute inflammation models. The lectin was purified from the crude saline extract by affinity chromatography on a guar-gum matrix. Native, heat-treated, and digested lectin was evaluated for anti-inflammatory activity by using peritonitis and paw edema models. The anti-inflammatory activity was characterized by intravital microscopy, nitric oxide production, and myeloperoxidase activity. The lectin exhibited anti-inflammatory activity (2 mg/kg) on both models, reducing local myeloperoxidase activity. Galactose or heat treatment (100A degrees C, 10 min) reduced anti-inflammatory action. Anti-inflammation involves the inhibition of adhesion and rolling of leukocytes along with augmentation of nitric oxide in serum. The lectin inhibited the edematogenic effect of histamine and prostaglandins (PGE2) but did not alter the chemoattractant effect of IL-8. The results indicate that this lectin is a potent anti-inflammatory molecule. Its effects engage diverse modulatory events.
Resumo:
The objective of the present study was to evaluate the effects of different gamma radiation doses on the growth of Alternaria alternata and on the production of toxins alternariol (AOH), and alternariol monomethyl ether (AME) in sunflower seed samples. After irradiation with 2, 5 and 7 kGy, the spore mass was resuspended in sterile distilled water and the suspension was inoculated into sunflower seeds. The number of colony-forming units per gram (CFU/g) was determined after culture on Dichloran Rose Bengal Chloramphenicol and Dichloran Chloramphenicol Malt Extract Agar. The presence of AOH and AME was investigated by liquid chromatography coupled to mass spectrometry. The radiation doses used resulted in a reduction of the number of A. alternata CFU/g and of AOH and AME levels when compared to the nonirradiated control group. Maximum reduction of the fungus (98.5%) and toxins (99.9%) was observed at a dose of 7 and 5 kGy, respectively. Under the present conditions, gamma radiation was found to be an alternative for the control of A. alternata and, consequently, of AOH and AME production in sunflower seeds. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
A method for the multi-elemental determination of metals (Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Sr and Zn), metalloids (B and Si), and non-metals (Cl, P and 5) in the babassu nut and mesocarp, sapucaia nut, coconut pulp, cupuassu pulp and seed, and cashew nut by axially viewed inductively coupled plasma optical emission spectrometry is presented. A diluted oxidant mixture (2 ml HNO(3) + 1 ml H(2)O(2) + 3 ml H(2)O) was used to achieve the complete decomposition of the organic matrix in a closed-vessel microwave oven. The accuracy of the entire proposed method was confirmed by standard reference material analysis (peach leaves-NIST SRM1547). The certified values showed a good agreement at a 95% confidence limit (Student`s t-test). The average RSD for repeatability of calibration solutions measurements were in the range of 1.1-6.7%. Limits of quantification (LOQ = 10 x LOD) were in the level of 0.00072-0.0532 mg/l. The macro and micronutrient ranges in the different nuts and seeds did not exceed the dietary reference intake (DRI), except for Mn in the babassu nut. (C) 2010 Published by Elsevier Ltd.
Resumo:
The objective of the present study was to evaluate the effects of light and temperature on germination of Cereus pernambucensis seeds, a species of columnar cactus native to Brazil and naturally incident in the restinga. Cereus pernambucensis seeds were incubated under different temperatures, from 5 to 45 °C, with 5 °C intervals, and under alternating temperatures of 15-20 °C, 15-30 °C, 20-25 °C, 20-30 °C, 20-35 °C, 25-30 °C, 25-35 °C, and 30-35 °C, both under continuous white light and dark. The seeds were also incubated in a gradient of phytochrome photoequilibrium at 25 °C. The highest percentage germination in this species was between 25 and 30 °C. The minimum temperature was between 15 and 20 °C and the maximum between 35 and 40 °C. Alternating temperatures did not affect the percentage of seed germination, but it did alter the rate and synchronization indexes. Seeds incubated in the dark did not germinate under any of the conditions tested, indicating that this species when cultivated present light sensitive seeds controlled by phytochrome. The seeds can tolerate a lot of shade conditions, germinating under very low fluence response of phytochrome.
Resumo:
Yellow fever (YF) is an acute viral infectious disease transmitted by mosquitoes which occurs in two distinct epidemiological cycles: sylvatic and urban. In the sylvatic cycle, the virus is maintained by monkey's infection and transovarian transmission in vectors. Surveillance of non-human primates is required for the detection of viral circulation during epizootics, and for the identification of unaffected or transition areas. An ELISA (enzyme-linked immunosorbent assay) was standardized for estimation of the prevalence of IgG antibodies against yellow fever virus in monkey sera (Alouatta caraya) from the reservoir area of Porto Primavera Hydroelectric Plant, in the state of São Paulo, Brazil. A total of 570 monkey sera samples were tested and none was reactive to antibodies against yellow fever virus. The results corroborate the epidemiology of yellow fever in the area. Even though it is considered a transition area, there were no reports to date of epizootics or yellow fever outbreaks in humans. Also, entomological investigations did not detect the presence of vectors of this arbovirus infection. ELISA proved to be fast, sensitive, an adequate assay, and an instrument for active search in the epidemiological surveillance of yellow fever allowing the implementation of prevention actions, even before the occurrence of epizootics.
Resumo:
A febre amarela (FA) é doença infecciosa aguda de origem viral transmitida por mosquitos. No ciclo silvestre, o vírus é mantido por meio da infecção de macacos e da transmissão transovariana nos vetores. A vigilância sobre populações de primatas não humanos torna-se necessária para detectar a circulação viral, quando ainda está restrito a epizootias, e para determinar sua presença em regiões indenes ou de transição para a doença. Padronizou-se a técnica ELISA (Enzyme Linked Immunosorbent Assay) para determinar a prevalência de anticorpos da classe IgG contra o vírus da FA em soros de bugios (Alouatta caraya) da região do reservatório da Usina Hidrelétrica de Porto Primavera, SP. Foram testados soros de 570 macacos sendo que nenhuma amostra mostrou-se reativa para a presença de anticorpos contra o vírus da FA. Os resultados são coerentes com a epidemiologia da FA na região. Mesmo sendo área de transição, não se conhece, até o momento, ocorrência de epizootia ou surto de FA em humanos e investigações entomológicas não apontaram a presença de vetores para esta arbovirose. A técnica mostrou-se sensível, rápida e útil à vigilância epidemiológica como instrumento de busca ativa permitindo desencadear ações preventivas, como vacinação, antes mesmo do surgimento de epizootias
Resumo:
Toxic principles from seeds of Aeschynomene indica collected in Brazil were analyzed. Dalpanol, 12 alpha-hydroxydalpanol and 11-hydroxydalpanol were identified using (1)H NMR in A. indica for the first time. 11-hydroxydalpanol has not been previously reported in the existing literature. Furthermore these rotenoids are likely the toxic principles that cause neurological signs in mice.
Resumo:
We investigated the inhibitory potential of aqueous extracts of bark and leaves of Esenbeckia leiocarpa Engl. on lettuce germination and early seedling growth. We compared the effects of four concentrations (100, 75, 50 and 25%) of each extract to water and polyethylene glycol (PEG 6000) solution controls for four replicates of 50 seeds tor germination and four replicates of ten seedlings for seedling growth. The inhibitory effects of E. leiocarpa extracts on the percentage of germination and on the germination speed seemed to be inure than simply an osmotic effect, except for the percentage of seeds germinated in bark extracts. When compared to water control. both bark and leaf extracts delayed germination, and leaf extracts also affected the percentage of germinated seeds. Leaf ex tracts of all concentrations strongly inhibited the development of seedlings and caused them some degree of abnormality; bark extracts also caused abnormalities and reduced seedling growth. Root development was more sensitive to the extracts than hypocotyl growth. The negative effects of leaf extracts on germination and seedling growth were more pronounced than those of bark extracts, and the overall effects of both extracts were positively correlated with extract concentrations.
Resumo:
Aspartate kinase (AK, EC 2.7.2.4), homoserine dehydrogenase (HSDH, EC 1.1.1.3) and dihydrodipicolinate synthase (DHDPS, EC 4.2.1.52) were isolated and partially purified from immature Chenopodium quinoa Willd seeds. Enzyme activities were studied in the presence of the aspartate-derived amino acids lysine, threonine and methionine and also the lysine analogue S-2-aminoethyl-L-cysteine (AEC), at 1 mM and 5 mM. The results confirmed the existence of, at least, two AK isoenzymes, one inhibited by lysine and the other inhibited by threonine, the latter being predominant in quinoa seeds. HSDH activity was also shown to be partially inhibited by threonine, whereas some of the activity was resistant to the inhibitory effect, indicating the presence of two isoenzymes, one resistant and another sensitive to threonine inhibition. Only one DHDPS isoenzyme highly sensitive to lysine inhibition was detected. The results suggest that the high concentration of lysine observed in quinoa seeds is possibly due to a combined effect of increased lysine, synthesis and accumulation in the soluble form and/or as protein lysine. Nitrogen assimilation was also investigated and based on nitrate content, nitrate reductase activity, amino acid distribution and ureide content, the leaves were identified as the predominant site of nitrate reduction in this plant species. The amino acid profile analysis in leaves and roots also indicated an important role of soluble glutamine as a nitrogen transporting compound. (c) 2007 Elsevier Masson SAS. All rights reserved.
Resumo:
The phenolic compounds content and antioxidant activity of seed and skin of pomace from the vinification of grape varieties widely produced in Brazil were investigated with a view to their exploitation as a potential source of natural antioxidants. There was a greater concentration of phenolic compounds in the seeds (2128 to 16,518 mg of catechin equivalents (CE)/100 g) than in the skins (660 to 1839 mg CE/100 g). The highest antioxidant activity values determined as DPPH radical-scavenging ability and ferric reducing-antioxidant power (FRAP) were found for the seeds of the Pinot Noir variety (16,925 mu mol Trolox equivalents (TE)/100 g and 21,492 mu mol Fe(2+)/100 g, respectively) and in the skin extracts of the Isabel variety (3640 mu mol TE/100 g and 4362 mu mol Fe(2+)/100 g, respectively). The skin of Cabernet Sauvignon and Primitivo varieties had the highest contents of anthocyanins (935 and 832 mg/100 g, respectively). The grape seed extracts were rich in oligomeric and polymeric flavanols. The data suggested that grape seed and skin extracts may be exploited as antioxidant agents. (C) 2011 Elsevier Ltd. All rights reserved.
Resumo:
Seed coats, cotyledons and hypocotyls from six Peruvian (Lupinus mutabilis Sweet) and two Brazilian (Lupinus albus and Lupinus angustifolius) lupin cultivars were assessed regarding their content of isoflavones and antioxidant capacity. Genistein and a genistein derivative were detected in seed coats and cotyledons from Peruvian cultivars. Total isoflavones ranged from 9.8 to 87, 16.1 to 30.8 and 1.3 to 6.1 mg/100 g of sample in fresh weight (expressed as genistein) in seed coat, cotyledon and hypocotyl fractions, respectively, from mutabilis species, whereas no isoflavones were detected in L. angustifolius and L. albus. A significant correlation (r = 0.99) was found between the total isoflavone levels and the antioxidant capacity measured by the 2,2-diphenyl-1-picrylhydrazyl radical-scavenging method in all fractions of Peruvian samples. No condensed tannins were detected in any of the lupin cultivars. The H-6 Andean cultivar is promising for its high isoflavone content and antioxidant capacity. Insights from this study indicate that lupin cultivars of the mutabilis species have similar isoflavone profiles and that isoflavones are more concentrated in the cotyledon seed fraction than in the seed coat or hypocotyl fractions. (C) 2008 Elsevier Inc. All rights reserved.
Resumo:
We determined the prophylactic effect of both the d-mannose-binding lectin ArtinM extracted from the seeds of Artocarpus integrifolia (jackfruit) and its recombinant counterpart during the course of experimental paracoccidioidomycosis induced in BALB/c mice. Four experimental protocols of prophylaxis were employed to evaluate the most protective regimen of ArtinM administration. It was demonstrated that the best effect was obtained by administration of two ArtinM doses on days 10 and 3 before the challenge with Paracoccidioides brasiliensis. By following this protocol, the lungs of mice that received native or recombinant ArtinM exhibited reduced fungal burden and granuloma incidence. In addition, the protocol augmented contents of IL-12, IFN-gamma, TNF-alpha and NO. On the other hand, the control group consisting of untreated infected mice had higher pulmonary levels of IL-4 and IL-10. In conclusion, prophylaxis with ArtinM significantly reproduces the effect of its therapeutic administration, i.e, it confers resistance to P. brasiliensis infection in mouse models by promoting IL-12 production and favours Th1-immunity.