RESUMO
Aiming to understand Nature´s strategies that inspire new composite materials, the hierarchical levels of organization of the Brazil nut (Bertholletia excelsa) mesocarp were investigated. Optical microscopy, scanning electron microscopy (SEM), microtomography (MicroCT) and small-angle X-ray scattering (SAXS) were used to deeply describe the cellular and fibrillary levels of organization. The mesocarp is the middle layer of the fruit which has developed several strategies to avoid its opening and protect its seed. Fibers have a different orientation in the three layers of the mesocarp, what reduces the anisotropy of the structure. Sclereids cells with thick cell walls fill the spaces between the fibers resembling a foam-filled structural composite. The mesocarp has several tubular channels and fractured surfaces which may work as sites for crack trapping and increase toughness. The thick and lignified cell wall of sclereids and fibers and the weak interface between cells can promote a longer and tortuous intercellular crack path. Additionally, fibers with high strength and stiffness due to microfibrils oriented along the main cell axis (µ = 0° to 17°) were identified in the innermost layer of the mesocarp. Such an understanding of each hierarchical level can inspire the development of new cellular composites with improved mechanical behavior.
Assuntos
Bertholletia/metabolismo , Parede Celular/metabolismo , Frutas/metabolismo , Microfibrilas/metabolismo , Sementes/metabolismo , Algoritmos , Bertholletia/anatomia & histologia , Bertholletia/ultraestrutura , Parede Celular/ultraestrutura , Frutas/anatomia & histologia , Frutas/ultraestrutura , Humanos , Microfibrilas/ultraestrutura , Microscopia Eletrônica de Varredura/métodos , Espalhamento a Baixo Ângulo , Sementes/anatomia & histologia , Sementes/ultraestrutura , Difração de Raios X/métodos , Microtomografia por Raio-X/métodosRESUMO
Secretory structures were little studied in Gentianaceae. Glandular areas on the calyx dorsal region are commonly reported for Helieae species, the main tribe of Gentianaceae. So, the elucidation of nature of glandular areas is particularly relevant. Trichomes secreting mucilage, interpreted as colleters, are reported only for the sepals of Gentianinae species. We aimed to anatomically characterize and identify the nature of the calycinal secretory structures in Calolisianthus pedunculatus. Samples from floral buds, flowers, and fruits were collected, fixed, and processed following usual procedures for light and scanning electron microscopies. Histochemical tests were performed to determine the nature of the secretion. Glucose, fructose, and sucrose were measured with an ELISA reader. Colleters occur on the sepal ventral region and are composed of a multicellular secretory head and a stalk. These structures secrete polysaccharides and proteins, and the secretion is probably released through cuticle microchannels. Nectaries, on the other hand, occur on the sepal dorsal region. They are formed by 3-5 cells arranged in rosettes circling a central cell or pore. These structures also secrete polysaccharides (mainly fructose), lipids, and proteins. The identification of the secretory structures in the sepals of Calolisianthus pedunculatus highlights the importance of anatomical studies in this family. The interpretation of the glandular areas on the calyx of the Helieae species as nectaries has been proven, as well as the confirmation of colleters as common structures in the sepals of Gentianaceae. Besides the taxonomic and phylogenetic importance of nectars and colleters, we highlight the importance of the secretion for the protection of floral buds against dehydration.
Assuntos
Flores/anatomia & histologia , Flores/citologia , Gentianaceae/anatomia & histologia , Gentianaceae/citologia , Histocitoquímica , Flores/ultraestrutura , Frutas/anatomia & histologia , Frutas/ultraestrutura , Gentianaceae/ultraestruturaRESUMO
Plastids are cell organelles that, beside other functions, have the capability to store carotenoids in specialized structures, which may vary among the different plant species, tissues or according to the carotenoid complement. Fruits are an important source of carotenoids, and during ripening, chloroplasts differentiate into chromoplasts that are able to accumulate large amounts of carotenoids, rendering then the characteristic fruit coloration. Whereas lycopene or ß-carotene may accumulate as crystal in the chromoplasts of some fruit, other xanthophyll-accumulating fruits differentiate plastoglobuli as a preferred system to enhance carotenoids stability and storage. Visualization of plastid ultrastructure and their transformation during ripening or in fruit of contrasting coloration are fundamental objectives within carotenoids research in fruits. Therefore, in this chapter, we describe a protocol for the visualization and analysis of plastid ultrastructure by transmission electron microscopy (TEM), specially designed and adapted to fruit tissues.
Assuntos
Carotenoides/metabolismo , Frutas/metabolismo , Frutas/ultraestrutura , Transporte Biológico , Microscopia Eletrônica de TransmissãoRESUMO
PREMISE OF THE STUDY: The fossil record is critical for testing biogeographic hypotheses. Menispermaceae (moonseeds) are a widespread family with a rich fossil record and alternative hypotheses related to their origin and diversification. The family is well-represented in Cenozoic deposits of the northern hemisphere, but the record in the southern hemisphere is sparse. Filling in the southern record of moonseeds will improve our ability to evaluate alternative biogeographic hypotheses. METHODS: Fossils were collected from the Salamanca (early Paleocene, Danian) and the Huitrera (early Eocene, Ypresian) formations in Chubut Province, Argentina. We photographed them using light microscopy, epifluorescence, and scanning electron microscopy and compared the fossils with similar extant and fossil Menispermaceae using herbarium specimens and published literature. KEY RESULTS: We describe fossil leaves and endocarps attributed to Menispermaceae from Argentinean Patagonia. The leaves are identified to the family, and the endocarps are further identified to the tribe Cissampelideae. The Salamancan endocarp is assigned to the extant genus Stephania. These fossils significantly expand the known range of Menispermaceae in South America, and they include the oldest (ca. 64 Ma) unequivocal evidence of the family worldwide. CONCLUSIONS: Our findings highlight the importance of West Gondwana in the evolution of Menispermaceae during the Paleogene. Currently, the fossil record does not discern between a Laurasian or Gondwanan origin; however, it does demonstrate that Menispermaceae grew well outside the tropics by the early Paleocene. The endocarps' affinity with Cissampelideae suggests that diversification of the family was well underway by the earliest Paleocene.
Assuntos
Fósseis/anatomia & histologia , Menispermaceae/anatomia & histologia , Menispermaceae/classificação , Argentina , Fósseis/ultraestrutura , Frutas/anatomia & histologia , Frutas/classificação , Frutas/ultraestrutura , Menispermaceae/ultraestrutura , Microscopia Eletrônica de Varredura , Dispersão Vegetal , Folhas de Planta/anatomia & histologia , Folhas de Planta/classificação , Folhas de Planta/ultraestruturaRESUMO
Due to its organoleptic and nutraceutical qualities, strawberry fruit (Fragaria x ananassa, Duch) is a worldwide important commodity. The role of ethylene in the regulation of strawberry cell wall metabolism was studied in fruit from Toyonoka cultivar harvested at white stage, when most changes associated with fruit ripening have begun. Fruit were treated with ethephon, an ethylene-releasing reagent, or with 1-methylcyclopropene (1-MCP), a competitive inhibitor of ethylene action, maintaining a set of non-treated fruit as controls for each condition. Ethephon treated-fruit showed higher contents of hemicelluloses, cellulose and neutral sugars regarding controls, while 1-MCP-treated fruit showed a lower amount of those fractions. On the other hand, ethephon-treated fruit presented a lower quantity of galacturonic acid from ionically and covalently bound pectins regarding controls, while 1-MCP-treated fruit showed higher contents of those components. We also explored the ethylene effect over the mRNA accumulation of genes related to pectins and hemicelluloses metabolism, and a relationship between gene expression patterns and cell wall polysaccharides contents was shown. Moreover, we detected that strawberry necrotrophic pathogens growth more easily on plates containing cell walls from ethephon-treated fruit regarding controls, while a lower growth rate was observed when cell walls from 1-MCP treated fruit were used as the only carbon source, suggesting an effect of ethylene on cell wall structure. Around 60% of strawberry cell wall is made up of pectins, which in turns is 70% made by homogalacturonans. Our findings support the idea of a central role for pectins on strawberry fruit softening and a participation of ethylene in the regulation of this process.
Assuntos
Parede Celular/metabolismo , Etilenos/farmacologia , Fragaria/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Metabolismo dos Carboidratos/efeitos dos fármacos , Celulose/metabolismo , Etilenos/metabolismo , Fragaria/microbiologia , Fragaria/ultraestrutura , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/ultraestrutura , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Pectinas/genética , Pectinas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Polissacarídeos/metabolismo , RNA Mensageiro/metabolismoRESUMO
The arils of Bixa orellana L. seeds contain carotenoid storage cells (CSCs). The main compounds in these cells include bixin and norbixin, which are important pigments in the food and pharmaceutical industries. Although many studies have been conducted on these chemical constituents, the cellular events that occur during the development of the carotenoid-accumulating cells in the arils and their relationship with the final carotenoid accumulation in the vacuoles remain unknown. In this study, the development of the CSCs in B. orellana arils was analyzed by light and transmission electron microscopy. Carotenoids formed in specialized cells, whose number and size increased during aril development. At various stages of development, the cytoplasm of the CSCs contained chromoplasts that held an extensive network of tubules and plastoglobules. Next to the chromoplasts, lipid droplets may fuse one another to form osmiophilic bodies. In addition, vesicles were observed next to the tonoplast. At the final stages of development, both the osmiophilic bodies and vesicles, which became quadrangular or rectangular, were stored in the vacuoles of the CSCs. This study reported for the first time the occurrence of different storage unit types within the vacuole of carotenoid storage cells.
Assuntos
Bixaceae/embriologia , Carotenoides/metabolismo , Células Vegetais/metabolismo , Sementes/metabolismo , Bixaceae/citologia , Bixaceae/ultraestrutura , Cotilédone/citologia , Cotilédone/metabolismo , Cotilédone/ultraestrutura , Frutas/citologia , Frutas/crescimento & desenvolvimento , Frutas/ultraestrutura , Células Vegetais/ultraestrutura , Sementes/citologia , Sementes/crescimento & desenvolvimento , Sementes/ultraestruturaRESUMO
Lignin is an important raw material for the sustainable biorefineries and also the forerunner of high-value added products, such as biocomposite for chemical, pharmaceutical and cement industries. Oil palm empty fruit bunches (OPEFB) were used for lignin preparation by successive treatment with 1% (w/w) H2SO4 at 121°C for 60 min and 2.5% NaOH at 121°C for 80 min resulting in the high lignin yield of 28.89%, corresponding to 68.82% of the original lignin. The lignin obtained was characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The results indicated a lignin with molecular masses ramping from 4500 kDa to 12,580 kDa. FTIR and NMR of these lignins showed more syringyl and p-hydroxyphenyl than guaiacyl units. Moderate acid/alkaline treatment provided lignin with high industrial potential and acid hydrolyzates rich in fermentable sugars and highly porous cellulosic fibers.
Assuntos
Arecaceae/metabolismo , Biotecnologia/métodos , Frutas/metabolismo , Lignina/metabolismo , Óleos de Plantas/metabolismo , Hidróxido de Sódio/farmacologia , Ácidos Sulfúricos/farmacologia , Arecaceae/efeitos dos fármacos , Arecaceae/ultraestrutura , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Frutas/efeitos dos fármacos , Frutas/ultraestrutura , Peso Molecular , Óleo de Palmeira , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
The genus Desmodium is represented in Santa Catarina State, Brazil, by 13 species, all with lomentaceous fruits. Shape, size and isthmus margin of loments vary, while the surface is glabrous, or covered by trichomes of different types. Morphological diversity of trichomes becomes particularly relevant to taxonomic description. The trichome types present on the surface of Desmodium fruits provide data for the identification and classification of species in the State. To assess this, three fruits of each species were collected and deposited at two herbaria, HBR and FLOR, in Santa Catarina, Brazil. Some rehydrated samples were examined using light microscopy (LM); and some sections were exposed to the following histochemical reagents: Sudan III for oils and Thionine for mucilage. The structural aspects of trichomes can be classified into uni- or multicel- lular and may still be simple, i.e., nonglandular or glandular. Using scanning electron microscopy (SEM), five types of trichomes were identified and analyzed among the Desmodium species studied: uncinate, uniseriate, globose multicellular, globose unicellular and subulate. Characteristics, such as loment margin and article form, glabrescent or pillous indument, trichome type, with or without papillous epidermal cells and epicuticular striations, showed relevant diagnostic value. An identification key was developed for Desmodium species from Santa Catarina State, Brazil, based on macro and micromorphological characters of the fruit.
Características morfológicas y micromorfológicos de frutos Desmodium (Leguminosae: Papilionoideae). El género Desmodium está representado en Santa Catarina, Brasil, por 13 especies, todas con frutos lomentaceos. Los lomentos han tenido variación en forma, tamaño y características del margen del istmo, y la superficie es glabra o cubierta por tricomas de diferentes tipos. La diversidad morfológica de los tricomas se vuelve particularmente relevante para la descripción taxonómica. Los tipos de tri- comas presentes en la superficie de los frutos Desmodium, proporcionan datos para la identificación y clasificación de las especies en el Estado de Santa Catarina, Brasil. Tres frutos de cada especie fueron recogidos y depositados en el Herbario (HBR y FLOR, Santa Catarina, Brasil). Algu- nas muestras fueron rehidratadas y examinadas usando microscopía de luz (LM), las secciones fueron expuestas a los siguientes reactivos histoquímicos: Sudan III para los aceites y Tionina para mucílago. Los aspectos estructurales de los tricomas se pueden clasificar en uni o multicelulares y pueden todavía ser simples, es decir, no glandular o glandular. Por medio del uso de la microscopía elec- trónica de barrido (SEM), cinco tipos de tricomas se han identificado y analizado entre las especies de Desmodium estudiadas: uncinado, uniseriado, globoso multicelular, globoso unicelular y subulado. Características como el margen del lomento y la forma del artículo, indumento glabrescente o piloso, tipo de tricomas con o sin células epidérmicas papilosas, y estrías epicuticulares mostraron valor de diagnóstico relevante. La clave de identificación fue desarrollada para especies de Desmodium del Estado de Santa Catarina, Brasil, basado en caracteres macro y micromorfológicos del fruto.
Assuntos
Fabaceae/anatomia & histologia , Frutas/anatomia & histologia , Tricomas/anatomia & histologia , Brasil , Fabaceae/classificação , Fabaceae/ultraestrutura , Frutas/ultraestrutura , Microscopia Eletrônica de Varredura , Tricomas/ultraestruturaRESUMO
This study aimed to establish calibration models to assess soluble solids contents and flesh firmness in a non destructive way in peaches from Chimarrita, Maciel, Eldorado and Jubileu varieties, watching the harvest season effect on these models. Thereunto, in the first year of execution it was used the spectrophotometer Nir-Case (SACMI) in order to determine the calibrations equations for each cultivar from the non destructive and destructive evaluations. After that the performance of these models were evaluated through the procedure of validation with the remark of the results of determination coefficient (R2) and standard error of the predicted values (SEP). In the second year of experiment, using the same equipment and methodology, harvest dates along the peach maturation period were stipulated and calibrations models were developed for each cultivar studied. According to the results it can be concluded that the proposed models for evaluation of quality of fruit were satisfactory and the same result was not observed in the flesh firmness in the first year. In the second year it was observed that the statistics parameters values relative to the validation of the established models change along different periods during harvest seasons. However, the R2 and SEP values were considered acceptable to estimate the content of soluble solids in all cultivars. The parameter of flesh firmness was only satisfactory for the cultivars Eldorado and Jubileu.(AU)
O objetivo deste estudo foi estabelecer modelos de calibração para estimar sólidos solúveis e firmeza da polpa de forma não destrutiva em pêssegos Chimarrita, Maciel, Eldorado e Jubileu observando o efeito da época da colheita das frutas sobre estes modelos. Para isto, no primeiro ano de execução foi utilizado o espectrofotômetro NIR-Case (SACMI) no qual foram estabelecidas as equações de calibração para cada cultivar a partir das avaliações por métodos não destrutivos e destrutivos e, posteriormente, testou-se o desempenho destes modelos através do procedimento da validação com a observação dos resultados coeficiente de determinação (R2) e erro padrão dos valores previstos (SEP). No segundo ano de experimento utilizando o mesmo equipamento e metodologia, datas de colheitas ao longo da maturação dos pêssegos foram estipuladas e nestas foram desenvolvidos modelos de calibração para cada cultivar estudada. De acordo com os resultados obtidos, conclui-se que os modelos propostos para avaliação da qualidade das frutas foram satisfatórios para predizer o teor de sólidos solúveis nas cultivares em estudo, e o mesmo resultado não foi observado em relação à firmeza de polpa no primeiro ano de avaliação. No segundo ano observou-se que os valores dos parâmetros estatísticos referentes a validação dos modelos estabelecidos se alteram ao longo das diferentes épocas de colheita, mas comvalores de R2 e SEP aceitáveis para estimar os teores de sólidos solúveis em todas as cultivares e para oparâmetro firmeza de polpa apenas para as cultivares Eldorado e Jubileu os valores foram consideradossatisfatórios.(AU)
Assuntos
Prunus persica/crescimento & desenvolvimento , Prunus persica/ultraestrutura , Frutas/ultraestrutura , Qualidade dos Alimentos , Análise Espectral , Espectroscopia de Luz Próxima ao InfravermelhoRESUMO
The genus Desmodium is represented in Santa Catarina State, Brazil, by 13 species, all with lomen- taceous fruits. Shape, size and isthmus margin of loments vary, while the surface is glabrous, or covered by trichomes of different types. Morphological diversity of trichomes becomes particularly relevant to taxonomic description. The trichome types present on the surface of Desmodium fruits provide data for the identification and classification of species in the State. To assess this, three fruits of each species were collected and deposited at two herbaria, HBR and FLOR, in Santa Catarina, Brazil. Some rehydrated samples were examined using light microscopy (LM); and some sections were exposed to the following histochemical reagents: Sudan III for oils and Thionine for mucilage. The structural aspects of trichomes can be classified into uni- or multicellular and may still be simple, i.e., nonglandular or glandular. Using scanning electron microscopy (SEM), five types of trichomes were identified and analyzed among the Desmodium species studied: uncinate, uniseriate, globose multicellular, globose unicellular and subulate. Characteristics, such as loment margin and article form, glabrescent or pillous indument, trichome type, with or without papillous epidermal cells and epicuticular striations, showed relevant diagnostic value. An identification key was developed for Desmodium species from Santa Catarina State, Brazil, based on macro and micromorphological characters of the fruit.
Assuntos
Fabaceae/anatomia & histologia , Frutas/anatomia & histologia , Tricomas/anatomia & histologia , Brasil , Fabaceae/classificação , Fabaceae/ultraestrutura , Frutas/ultraestrutura , Microscopia Eletrônica de Varredura , Tricomas/ultraestruturaRESUMO
This study aimed to establish calibration models to assess soluble solids contents and flesh firmness in a non destructive way in peaches from Chimarrita, Maciel, Eldorado and Jubileu varieties, watching the harvest season effect on these models. Thereunto, in the first year of execution it was used the spectrophotometer Nir-Case (SACMI) in order to determine the calibrations equations for each cultivar from the non destructive and destructive evaluations. After that the performance of these models were evaluated through the procedure of validation with the remark of the results of determination coefficient (R2) and standard error of the predicted values (SEP). In the second year of experiment, using the same equipment and methodology, harvest dates along the peach maturation period were stipulated and calibrations models were developed for each cultivar studied. According to the results it can be concluded that the proposed models for evaluation of quality of fruit were satisfactory and the same result was not observed in the flesh firmness in the first year. In the second year it was observed that the statistics parameters values relative to the validation of the established models change along different periods during harvest seasons. However, the R2 and SEP values were considered acceptable to estimate the content of soluble solids in all cultivars. The parameter of flesh firmness was only satisfactory for the cultivars Eldorado and Jubileu.
O objetivo deste estudo foi estabelecer modelos de calibração para estimar sólidos solúveis e firmeza da polpa de forma não destrutiva em pêssegos Chimarrita, Maciel, Eldorado e Jubileu observando o efeito da época da colheita das frutas sobre estes modelos. Para isto, no primeiro ano de execução foi utilizado o espectrofotômetro NIR-Case (SACMI) no qual foram estabelecidas as equações de calibração para cada cultivar a partir das avaliações por métodos não destrutivos e destrutivos e, posteriormente, testou-se o desempenho destes modelos através do procedimento da validação com a observação dos resultados coeficiente de determinação (R2) e erro padrão dos valores previstos (SEP). No segundo ano de experimento utilizando o mesmo equipamento e metodologia, datas de colheitas ao longo da maturação dos pêssegos foram estipuladas e nestas foram desenvolvidos modelos de calibração para cada cultivar estudada. De acordo com os resultados obtidos, conclui-se que os modelos propostos para avaliação da qualidade das frutas foram satisfatórios para predizer o teor de sólidos solúveis nas cultivares em estudo, e o mesmo resultado não foi observado em relação à firmeza de polpa no primeiro ano de avaliação. No segundo ano observou-se que os valores dos parâmetros estatísticos referentes a validação dos modelos estabelecidos se alteram ao longo das diferentes épocas de colheita, mas comvalores de R2 e SEP aceitáveis para estimar os teores de sólidos solúveis em todas as cultivares e para oparâmetro firmeza de polpa apenas para as cultivares Eldorado e Jubileu os valores foram consideradossatisfatórios.
Assuntos
Frutas/ultraestrutura , Prunus persica/crescimento & desenvolvimento , Prunus persica/ultraestrutura , Qualidade dos Alimentos , Análise Espectral , Espectroscopia de Luz Próxima ao InfravermelhoRESUMO
BACKGROUND: The micromorphology and anatomy of nutlets, myxocarpy (mucilage exudation) and mucilage structure of Argentinean chia were described using scanning electron microscopy (SEM). The proximal composition of nutlets and mucilage was also studied. RESULTS: Chia nutlets are made up of a true seed and a pericarp enclosing the seed; they are small, glabrous, elliptic and apically rounded. The pericarp has cuticle, exocarp, mesocarp and bone cells vertically arranged and endocarp. The myxocarpy was carefully recorded by SEM. After 5 min in contact with water, the cuticle of nutlets is broken and the exocarp cell content gradually surrounds the rest of the nutlet. The proximal composition of chia nutlets was studied; fat is the major component (327 ± 8.0 g kg(-1)) followed by protein (293 ± 4.0 g kg(-1)) and fiber (276 ± 1.0 g kg(-1)). Extractions of chia nutlets with water at room temperature yielded 38 ± 1.0 g kg(-1) (dry basis) of mucilage. The fresh mucilage structure was similar to a network of open pores. The freeze-dried crude mucilage contained more ash, residual fat and protein than commercial guar and locust bean gum. The solubility of 10.0 g L(-1) w/v solution of chia freeze-dried crude mucilage in water increased with temperature, being maximal at 60 °C (870 g kg(-1)). CONCLUSION: The results obtained show a fast exudation of chia mucilage when nutlets are in contact with water. The freeze-dried crude mucilage hydrates easily in water, even at low temperatures. Chia nutlets have mucilaginous substances, with interesting functional properties from a technological and physiological point of view.
Assuntos
Fibras na Dieta/análise , Frutas/química , Exsudatos de Plantas/química , Salvia/química , Sementes/química , Argentina , Dieta , Liofilização , Frutas/metabolismo , Frutas/ultraestrutura , Humanos , Salvia/ultraestrutura , Sementes/ultraestrutura , Solubilidade , Temperatura , ÁguaRESUMO
BACKGROUND AND AIMS: The pollination biology of very few Chloraeinae orchids has been studied to date, and most of these studies have focused on breeding systems and fruiting success. Chloraea membranacea Lindl. is one of the few non-Andean species in this group, and the aim of the present contribution is to elucidate the pollination biology, functional floral morphology and breeding system in native populations of this species from Argentina (Buenos Aires) and Brazil (Rio Grande do Sul State). METHODS: Floral features were examined using light microscopy, and scanning and transmission electron microscopy. The breeding system was studied by means of controlled pollinations applied to plants, either bagged in the field or cultivated in a glasshouse. Pollination observations were made on natural populations, and pollinator behaviour was recorded by means of photography and video. KEY RESULTS: Both Argentinean and Brazilian plants were very consistent regarding all studied features. Flowers are nectarless but scented and anatomical analysis indicates that the dark, clavate projections on the adaxial labellar surface are osmophores (scent-producing glands). The plants are self-compatible but pollinator-dependent. The fruit-set obtained through cross-pollination and manual self-pollination was almost identical. The main pollinators are male and female Halictidae bees that withdraw the pollinarium when leaving the flower. Remarkably, the bees tend to visit more than one flower per inflorescence, thus promoting self-pollination (geitonogamy). Fruiting success in Brazilian plants reached 60·78 % in 2010 and 46 % in 2011. Some pollinarium-laden female bees were observed transferring pollen from the carried pollinarium to their hind legs. The use of pollen by pollinators is a rare record for Orchidaceae in general. CONCLUSIONS: Chloraea membrancea is pollinated by deceit. Together, self-compatibility, pollinarium texture, pollinator abundance and behaviour may account for the observed high fruiting success. It is suggested that a reappraisal and re-analysis of important flower features in Chloraeinae orchids is necessary.
Assuntos
Abelhas/fisiologia , Inflorescência/fisiologia , Orchidaceae/fisiologia , Polinização , Animais , Argentina , Brasil , Cruzamento , Feminino , Frutas/genética , Frutas/fisiologia , Frutas/ultraestrutura , Inflorescência/genética , Inflorescência/ultraestrutura , Masculino , Orchidaceae/genética , Orchidaceae/ultraestrutura , Pólen/genética , Pólen/fisiologia , Pólen/ultraestrutura , Reprodução , Sementes/genética , Sementes/fisiologia , Sementes/ultraestrutura , AutofertilizaçãoRESUMO
UNLABELLED: The use of biosorbents to remove metals and metalloids from contaminated water systems has gained great usage in various parts of the world. The objective of the current study was to test lemon peels as biosorbents for As (V). Lemon peels were chemically characterized and arsenic contact experiments were performed to determine the adsorption capacity of the peels using different empirical models. The model that fit the experimental data was the Lagergren empirical model with a correlation coefficient of R= 0.8841. The results show that lemon peels were able to retain 474.8 µg of As (V)/g of biosorbent. PRACTICAL APPLICATION: Lemon agro-industrial waste can be useful in the removal of heavy metals, such as arsenic, from aqueous media.
Assuntos
Arsênio/química , Quelantes/química , Citrus/química , Frutas/química , Resíduos Industriais , Poluentes Químicos da Água/química , Adsorção , Arsênio/análise , Quelantes/análise , Cloretos/química , Citrus/ultraestrutura , Recuperação e Remediação Ambiental/economia , Recuperação e Remediação Ambiental/métodos , Compostos Férricos/química , Indústria de Processamento de Alimentos/economia , Frutas/ultraestrutura , Indicadores e Reagentes/química , Resíduos Industriais/análise , Resíduos Industriais/economia , Cinética , México , Microscopia Eletrônica de Varredura , Modelos Químicos , Oxirredução , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Poluentes Químicos da Água/análiseRESUMO
Activity and expression of polygalacturonase (PG), a hydrolytic enzyme involved in ultrastructural changes in the pericarp of sweet pepper (Capsicum annaum), were investigated at different ripening stages of the pepper cultivars Mandi and Talanduo. Molecular cloning of CaPG was carried out by constructing a cDNA library from three stages of fruit ripening. Morphological determination, PG assay, RT-PCR, and ultrastructural studies were used to quantify changes in CaPG gene expression in the pericarp from green, color change and fully ripened stages. We found that CaPG gene expression, PG activity and striking changes in the structure of the cell wall occurred with the transition of ripening stages. CaPG gene expression was high (obvious PCR products) in mature and ripened stages of both cultivars; however, the CaPG gene was not expressed in preclimacteric fruits or vegetative tissues. We conclude that developmental regulation of CaPG gene expression is instrumental for sweet pepper fruit ripening; its expression during development leads to dissolution of middle lamella and eventually disruption of the fully ripened cell wall.
Assuntos
Capsicum/enzimologia , Frutas/enzimologia , Poligalacturonase/genética , Capsicum/genética , Capsicum/crescimento & desenvolvimento , Capsicum/ultraestrutura , Parede Celular/enzimologia , Parede Celular/genética , Parede Celular/ultraestrutura , Clonagem Molecular , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/ultraestrutura , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Biblioteca Gênica , Microscopia Eletrônica de Transmissão , Poligalacturonase/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Virus infections in grapevine cause important economic losses and affect fruit quality worldwide. Although the phenotypic symptoms associated to viral infections have been described, the molecular plant response triggered by virus infection is still poorly understood in Vitis vinifera. As a first step to understand the fruit changes and mechanisms involved in the compatible grapevine-virus interaction, we analyzed the berry transcriptome in two stages of development in the red wine cultivar Cabernet Sauvignon infected with Grapevine leaf-roll-associated virus-3 (GLRaV-3). Analysis of global gene expression patterns indicate incomplete berry maturation in infected berries as compared to uninfected fruit suggesting viral infection interrupts the normal berry maturation process. Genes with altered expression in berries harvested from GLRaV-3-infected vines as compared to uninfected tissue include anthocyanin biosynthesis and sugar metabolism genes. The reduction in transcript accumulation for sugar and anthocyanin metabolism during fruit development is consistent with a dramatic reduction in anthocyanin biosynthesis as well as reduced sugar levels in berries, a hallmark phenotypic change observed in virus infected grapevines. Analysis of key regulatory factors provides a mechanism for the observed gene expression changes. Our results provide insight into commonly observed phenotypic alterations in virus infected vines and the molecular mechanisms associated with the plant response to the virus during berry ripening.
Assuntos
Antocianinas/biossíntese , Metabolismo dos Carboidratos , Closteroviridae/fisiologia , Frutas/virologia , Vitis/virologia , Vias Biossintéticas/genética , Análise por Conglomerados , Flavonoides/biossíntese , Frutas/crescimento & desenvolvimento , Frutas/ultraestrutura , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno , Microscopia Eletrônica de Transmissão , Análise de Sequência com Séries de Oligonucleotídeos , Doenças das Plantas/genética , Doenças das Plantas/virologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Vitis/genética , Vitis/metabolismoRESUMO
Advanced food processing methods that accomplish inactivation of microorganisms but minimize adverse thermal exposure are of great interest to the food industry. High pressure (HP) and pulsed electric field (PEF) processing are commercially applied to produce high quality fruit and vegetable products in the United States, Europe, and Japan. Both microbial and plant cell membranes are significantly altered following exposure to heat, HP, or PEF. Our research group sought to quantify the degree of damage to plant cell membranes that occurs as a result of exposure to heat, HP, or PEF, using the same analytical methods. In order to evaluate whether new advanced processing methods are superior to traditional thermal processing methods, it is necessary to compare them. In this review, we describe the existing state of knowledge related to effects of heat, HP, and PEF on both microbial and plant cells. The importance and relevance of compartmentalization in plant cells as it relates to fruit and vegetable quality is described and various methods for quantification of plant cell membrane integrity are discussed. These include electrolyte leakage, cell viability, and proton nuclear magnetic resonance (¹H-NMR).
Assuntos
Membrana Celular/metabolismo , Conservação de Alimentos/métodos , Frutas , Verduras , Membrana Celular/ultraestrutura , Técnicas Eletroquímicas , Frutas/química , Frutas/metabolismo , Frutas/microbiologia , Frutas/ultraestrutura , Temperatura Alta/efeitos adversos , Pressão Hidrostática/efeitos adversos , Viabilidade Microbiana , Controle de Qualidade , Verduras/química , Verduras/metabolismo , Verduras/microbiologia , Verduras/ultraestruturaRESUMO
BACKGROUND AND AIMS: The occurrence of nectaries in fruits is restricted to a minority of plant families and consistent reports of their occurrence are not found associated with Fabaceae, mainly showing cellular details. The present study aims to describe the anatomical organization and ultrastructure of the pericarpial nectaries (PNs) in Erythrina speciosa, a bird-pollinated species, discussing functional aspects of these unusual structures. METHODS: Samples of floral buds, ovaries of flowers at anthesis and fruits at several developmental stages were fixed and processed by the usual methods for studies using light, and scanning and transmission electron microscopy. Nectar samples collected by filter paper wicks were subjected to chemical analysis using thin-layer chromatography. KEY RESULTS: The PNs are distributed in isolation on the exocarp. Each PN is represented by a single hyaline trichome that consists of a basal cell at epidermal level, stalk cell(s) and a small secretory multicellular head. The apical stalk cell shows inner periclinal and anticlinal walls impregnated by lipids and lignin and has dense cytoplasm with a prevalence of mitochondria and endoplasmic reticulum. The secretory cells show voluminous nuclei and dense cytoplasm, which predominantly has dictyosomes, rough endoplasmic reticulum, plastids, mitochondria and free ribosomes. At the secretory stage the periplasmic space is prominent and contains secretion residues. Tests for sugar indicate the presence of non-reducing sugars in the secretory cells. Nectar samples from PNs contained sucrose, glucose and fructose. CONCLUSIONS: The secretory stage of these PNs extends until fruit maturation and evidence suggests that the energetic source of nectar production is based on pericarp photosynthesis. Patrolling ants were seen foraging on fruits during all stages of fruit development, which suggests that the PNs mediate a symbiotic relationship between ants and plant, similar to the common role of many extrafloral nectaries.
Assuntos
Erythrina/ultraestrutura , Flores/ultraestrutura , Animais , Erythrina/fisiologia , Flores/fisiologia , Frutas/crescimento & desenvolvimento , Frutas/ultraestrutura , Insetos/fisiologia , Microscopia Eletrônica de Transmissão , Polinização/fisiologiaRESUMO
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.
Assuntos
Fabaceae/ultraestrutura , Fabaceae/anatomia & histologia , Flores/anatomia & histologia , Flores/ultraestrutura , Frutas/anatomia & histologia , Frutas/ultraestrutura , Microscopia Eletrônica de VarreduraRESUMO
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.
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, ambos fenólicos, descamam irregularmente, sendo o diásporo constituído pela ala papirácea e quebradiça, ligada ao núcleo seminífero que abrange o mesocarpo mediano de células lignificadas, margeando feixes vasculares e muitos ductos secretores, que apresentam acúmulo de oleorresina e cujas células epiteliais tornam-se vacuoladas. O fruto de Pterodon emarginatus é, portanto, uma criptossâmara.