The role of the parenchyma sheath and PCD during the development of oil cavities in Pterodon pubescens (Leguminosae-Papilionoideae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

OIL GLANDS IN PTERODON PUBESCENS BENTH. (LEGUMINOSAE-PAPILIONOIDEAE): DISTRIBUTION, STRUCTURE, and SECRETION MECHANISMS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Differential effect of plant lectins on mast cells of different origins

Histamine release induced by plant lectins was studied with emphasis on the carbohydrate specificity, external calcium requirement, metal binding sites, and mast cell heterogeneity and on the importance of antibodies bound to the mast cell membrane to the lectin effect. Peritoneal mast cells were obtained by direct lavage of the rat peritoneal cavity and guinea pig intestine and hamster cheek pouch mast cells were obtained by dispersion with collagenase type IA. Histamine release was induced with concanavalin A (Con A), lectins from Canavalia brasiliensis, mannose-specific Cymbosema roseum, Maackia amurensis, Parkia platycephala, Triticum vulgaris (WGA), and demetallized Con A and C. brasiliensis, using 1-300 µg/ml lectin concentrations applied to Wistar rat peritoneal mast cells, peaking on 26.9, 21.0, 29.1, 24.9, 17.2, 10.7, 19.9, and 41.5%, respectively. This effect was inhibited in the absence of extracellular calcium. The lectins were also active on hamster cheek pouch mast cells (except demetallized Con A) and on Rowett nude rat (animal free of immunoglobulins) peritoneal mast cells (except for mannose-specific C. roseum, P. platycephala and WGA). No effect was observed in guinea pig intestine mast cells. Glucose-saturated Con A and C. brasiliensis also released histamine from Wistar rat peritoneal mast cells. These results suggest that histamine release induced by lectins is influenced by the heterogeneity of mast cells and depends on extracellular calcium. The results also suggest that this histamine release might occur by alternative mechanisms, because the usual mechanism of lectins is related to their binding properties to metals from which depend the binding to sugars, which would be their sites to bind to immunoglobulins. In the present study, we show that the histamine release by lectins was also induced by demetallized lectins and by sugar-saturated lectins (which would avoid their binding to other sugars). Additionally, the lectins also released histamine from Rowett nude mast cells that are free of immunoglobulins.

The use of biodiversity as source of new chemical entities against defined molecular targets for treatment of malaria, tuberculosis, and T-cell mediated diseases: a review

The modern approach to the development of new chemical entities against complex diseases, especially the neglected endemic diseases such as tuberculosis and malaria, is based on the use of defined molecular targets. Among the advantages, this approach allows (i) the search and identification of lead compounds with defined molecular mechanisms against a defined target (e.g. enzymes from defined pathways), (ii) the analysis of a great number of compounds with a favorable cost/benefit ratio, (iii) the development even in the initial stages of compounds with selective toxicity (the fundamental principle of chemotherapy), (iv) the evaluation of plant extracts as well as of pure substances. The current use of such technology, unfortunately, is concentrated in developed countries, especially in the big pharma. This fact contributes in a significant way to hamper the development of innovative new compounds to treat neglected diseases. The large biodiversity within the territory of Brazil puts the country in a strategic position to develop the rational and sustained exploration of new metabolites of therapeutic value. The extension of the country covers a wide range of climates, soil types, and altitudes, providing a unique set of selective pressures for the adaptation of plant life in these scenarios. Chemical diversity is also driven by these forces, in an attempt to best fit the plant communities to the particular abiotic stresses, fauna, and microbes that co-exist with them. Certain areas of vegetation (Amazonian Forest, Atlantic Forest, Araucaria Forest, Cerrado-Brazilian Savanna, and Caatinga) are rich in species and types of environments to be used to search for natural compounds active against tuberculosis, malaria, and chronic-degenerative diseases. The present review describes some strategies to search for natural compounds, whose choice can be based on ethnobotanical and chemotaxonomical studies, and screen for their ability to bind to immobilized drug targets and to inhibit their activities. Molecular cloning, gene knockout, protein expression and purification, N-terminal sequencing, and mass spectrometry are the methods of choice to provide homogeneous drug targets for immobilization by optimized chemical reactions. Plant extract preparations, fractionation of promising plant extracts, propagation protocols and definition of in planta studies to maximize product yield of plant species producing active compounds have to be performed to provide a continuing supply of bioactive materials. Chemical characterization of natural compounds, determination of mode of action by kinetics and other spectroscopic methods (MS, X-ray, NMR), as well as in vitro and in vivo biological assays, chemical derivatization, and structure-activity relationships have to be carried out to provide a thorough knowledge on which to base the search for natural compounds or their derivatives with biological activity.

Water content and GA(3)-induced embryonic cell expansion explain Euterpe edulis seed germination, rather than seed reserve mobilisation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Handicrafts from Jalapao (TO), Brazil, and their relationship to plant anatomy

EICHEMBERG, M. T. and V. L. SCATENA (Universidade Estadual Paulista, Departamento de Botanica, Rio Claro, São Paulo, Brazil). J. Torrey Bot. Soc. 138:34-40. 2011.-Handicrafts from Jalapao (TO), Brazil, and their Relationship to Plant Anatomy. In the state of Tocantins, midwestern Brazil, communities from the region of Jalapao use scapes of "capim dourado" (golden grass - Syngonanthus nitens- Eriocaulaceae) and leaves of "buriti" (Mauritia flexuosa - Arecaceae) to make handicrafts (baskets and ornaments). The predominant biome of this area is cerrado (savanna), with a notable presence of buriti in the "veredas" (swampy forest-like vegetation), and of golden grass, which is one of the most common plants in humid grasslands. These traditional handicrafts represent a significant source of income for local communities. The whole scapes of Syngonanthus nitens are used due to their golden color, which is a reflection of such internal structures as thick walled cells and lignin in the epidermis and cortex. The strips called "seda" (silk) used to sew the scapes in the making of handicrafts come from young leaves of Mauritia,flexuosa. They are constituted by the adaxial epidermis and bundles of subepidermic fibers, both showing thick-walled cells. Since the cells of the bundles of sclerenchymatic fibers from the abaxial surface of buriti leaves present stegmata containing silica bodies, their mechanical properties are less adapted to the production of "silk", justifying the use of the leaf adaxial surface. Anatomical characteristics such as the thickening and composition of the cell walls of both species together with sociocultural factors, allow a better knowledge of the use of plant structures in the making of handicrafts.

In vitro cytotoxic activity of Brazilian Middle West plant extracts

Cytotoxic activity of eight plant extracts, native from the Mid-West of Brazil comprising Cerrado, Pantanal and semideciduous forest, was evaluated for MDA-MB-435, SF-295, and HCT-8 cancer cell strains. A single 100 µg.mL-1 dose of each extract was employed with 72 h of incubation for all tests. Doxorubicin (1 µg.mL-1) was used as the positive control and the MTT method was used to detect the activity. Cytotoxicity of distinct polarities was observed in thirty extracts (46%), from different parts of the following species: Tabebuia heptaphylla (Vell.) Toledo, Bignoniaceae, Tapirira guianensis Aubl., Anacardiaceae, Myracrodruon urundeuva Allemão, Anacardiaceae, Schinus terebinthifolius Raddi, Anacardiaceae, Gomphrena elegans Mart., Amaranthaceae, Attalea phalerata Mart. ex Spreng., Arecaceae, Eugenia uniflora L., Myrtaceae, and Annona dioica A. St.-Hil., Annonaceae. Extracts of at least two tested cell strains were considered to be highly active since their inhibition rate was over 75%.

Ontogênese de caneluras em pedúnculo de flores de laranjeira doce infectados pelo vírus da tristeza dos citros estirpe Capão Bonito

Um estudo da ontogênese das caneluras induzidas em ramos de laranjeiras doces suscetíveis por isolados severos do vírus da tristeza dos citros (Citrus tristeza vírus - CTV) foi feito usando-se como modelo pedúnculos florais e de frutos. O menor calibre destes órgãos permite um melhor acompanhamento do processo. As observações foram feitas em laranjeira cv. Pêra infetada pelo isolado severo Capão Bonito do CTV. Cinco fases do processo de formação de caneluras puderam ser deduzidas pelas análises anatômicas. As primeiras alterações são representadas pelo aparecimento de células adensadas, hipertrofia e hiperplasia no parênquima e câmbio do floema e uma desorganização generalizada desta área. Segue-se uma atividade intensa do câmbio do floema adjacente e sua expansão em direção ao xilema. Esta invasão do xilema resulta na ruptura do anel do xilema pela massa celular do floema constituída de células recém formadas de parede celular delgada. Esta invasão do floema em direção ao xilema inicia um processo de degeneração dos vasos e parênquima do xilema. Finalmente há um colapso completo da região do xilema invadida, que é substituída pela massa do floema, resultando na canelura, notada ao se remover a casca.

Comparative genomic analysis of plant-associated bacteria

This review deals with a comparative analysis of seven genome sequences from plant-associated bacteria. These are the genomes of Agrobacterium tumefaciens, Mesorhizobium loti, Sinorhizobium meliloti, Xanthomonas campestris pv campestris, Xanthomonas axonopodis pv citri, Xylella fastidiosa, and Ralstonia solanacearum. Genome structure and the metabolism pathways available highlight the compromise between the genome size and lifestyle. Despite the recognized importance of the type III secretion system in controlling host compatibility, its presence is not universal in all necrogenic pathogens. Hemolysins, hemagglutinins, and some adhesins, previously reported only for mammalian pathogens, are present in most organisms discussed. Different numbers and combinations of cell wall degrading enzymes and genes to overcome the oxidative burst generally induced by the plant host are characterized in these genomes. A total of 19 genes not involved in housekeeping functions were found common to all these bacteria.

Effect of salt stress on polyamine metabolism in bean cell culture

The adaptive capacity of bean (Phaseolus vulgaris L.) calluses (cultivars IAC-carioca, JALO EEP-558, BAT-93 and IAPAR-14) to salt stress (0-80 mM) was verified to determine the existence of biochemical markers such as organic and inorganic compounds, and metabolism of polyamines. The results obtained demonstrate that salt (NaCl) interfered with all the parameters analyzed and its intensity ranged due to the salt concentration and the cultivars used.

Study of fuel cell co-generation systems applied to a dairy industry

This paper presents a methodology for the study of a molten carbonate fuel cell co-generation system. This system is applied to a dairy industry of medium size that typically demands 2100 kW of electricity, 8500 kg/h of saturated steam (P = 1.08 MPa) and 2725 kW of cold water production. Depending on the associated recuperation equipment, the co-generation system permits the recovery of waste heat, which can be used for the production of steam, hot and cold water, hot and cold air. In this study, a comparison is made between two configurations of fuel cell co-generation systems (FCCS). The plant performance has been evaluated on the basis of fuel utilisation efficiency and each system component evaluated on the basis of second law efficiency. The energy analysis presented shows a fuel utilisation efficiency of about 87% and exergy analysis shows that the irreversibilities in the combustion chamber of the plant are significant. Further, the payback period estimated for the fuel cell investment between US$ 1000 and US$ 1500/k-W is about 3 and 6 years, respectively. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Behavior of plant tissue in osmotic solutions

The effect of the concentration of sucrose solutions on the cellular structure of potato tissue in equilibrium at 27 degreesC was Studied. Two different methods of investigation were used to determine the volume of the different phases composing the cellular tissue of the potato when in equilibrium with the solutions. one based on data of the concentration itself and the overall volume of 2 mm slices after 48 h at equilibrium, and the other on microscopic images of cells in thin slices of fresh tissue stained with neutral red after an hour in equilibrium to show protoplasts, vacuoles and plasmolysis spaces. The results of these methods were compared with those obtained by a predictive thermodynamic approach considering the semipermeability of cell membranes. Phase volume data obtained from microscopic analysis were more similar to what was predicted by the theoretical model than those obtained by means of composition measurement. where the long equilibrium time apparently led to the loss of semi permeability of the cell membranes, since total volumes calculated without consideration of the cell membranes were similar to those measured. This suggests that the length of time of osmotic dehydration brings about a change in cell structure and the consequent involvement of a different mechanism in mass transfer. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Boron deficiency inhibits petiole and peduncle cell development and reduces growth of cotton

The effect of boron (B) on cotton growth and fruit shedding may be due not only to physiological or biochemical effects, but also to vascular tissue malformation. This experiment investigated petiole and floral peduncle anatomical alterations and growth of cotton supplied with deficient and sufficient B in nutrient solution. Cotton (Gossypium hirsutum cv. 'Delta Opal') plants were grown in solutions containing 0, 1.5, 3.0, 4.5, and 6.0 mu mol L-1 of B from 22 to 36 d after plant emergence (DAPE). From 36 to 51 DAPE, B was omitted from the nutrient solution. Petioles from young leaves and floral bud peduncles (first position of the first sympodial) were sampled and the cross-section anatomy observed under an optical microscope. The number of vascular bundles of the petiole was decreased in B-deficient plants and the xylem was disorganized. Phloem elements in the peduncle vascular cylinder of B-deficient plants did not show clear differentiation. The few xylem elements that were formed were also disorganized. Modifications caused by B deficiency may have impaired B and photosynthate translocation into new cotton growth. Boron accumulation in the shoot of B-deficient plants suggested that there was some B translocation within the plant. It could be inferred that cotton growth would be impaired by the decrease in carbohydrate translocation rather than by B deficiency in the tissue alone.

Cholangiocarcinoma and Squamous Cell Carcinoma of the Stratified Epithelial Portion of the Stomach in a Horse: A Case Report

Both cholangiocarcinoma and squamous cell carcinoma of the stomach stratified squamous epithelial portion are rarely found in equine medicine despite being more common in human beings, dogs, and cats. The objective of the present article was to report the simultaneous occurrences of these two types of neoplasias in an 11-year-old mare. Numerous firm, whitish nodules were distributed throughout the liver parenchyma and those protruding over its surface were umbilicated in their appearance. It was verified that the nodules adhered to the peritoneum and omentum, diaphragm, spleen, and stomach serosa compressed the adjacent structures. The stomach stratified squamous epithelial portion, particularly originating in the margo plicatus toward the cardia, was covered by numerous smooth, whitish spherules. Microscopic examination allowed the liver, tumor, and the abdominal implants to be identified as a cholangiocarcinoma, and the stomach neoplasia as a carcinoma of its stratified squamous epithelial portion. Considering this as an uncommon finding, although when considered individually, the presence of a cholangiocarcinoma and a squamous cell carcinoma of the stratified squamous epithelial portion of the equine stomach in the same specimen is worthy of reporting. (C) 2011 Elsevier B.V. All rights reserved.

In Vitro Evaluation of the Genotoxic Activity and Apoptosis Induction of the Extracts of Roots and Leaves from the Medicinal Plant Coccoloba mollis (Polygonaceae)

Coccoloba mollis (Family Polygonaceae) is a medicinal plant popularly used in cases of memory loss, stress, insomnia, anemia, impaired vision, and sexual impotence, but the scientific literature, to date, lacks studies on the biological effects of this species, particularly with regard to cytotoxicity and induction of DNA damage. The aim of the present study was to assess in vitro (in hepatic HTC cells) ethanolic extracts of the roots and leaves of C. mollis for cytotoxicity, genotoxicity, and induction of apoptosis. For these evaluations the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay, comet assay, micronucleus test with cytokinesis block, and an in situ test for detection of apoptotic cells with acridine orange staining were used. The results showed that the extract obtained from the roots of C. mollis is more cytotoxic than that obtained from the leaves and that the reduction in cell viability observed in the MTT assay was a result, at least in part, from the induction of apoptosis. Both extracts induced DNA damage at a concentration of 20 mu g/mL in the comet assay, but no genotoxicity was detected with any of the treatments carried out in the micronucleus test.