157 research outputs found

    Curcuma alismatifolia vase life

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    Cut curcuma stem has a reported vase life of 7 to 21 days and this difference in vase life is probably due to a combination of different factors such as growing conditions and postharvest treatments. However, the cut flower industry needs key postharvest information for new species and cultivars to be able to effectively market the flowers. The objectives of this study was to evaluate the effect of commercial hydrator and holding solutions, commercial growth regulator formulation, floral foam, ethylene and silver thiosulfate (STS) on the postharvest handling of C. alismatifolia cultivars. Control treatment (deionized water) had better vase life than the combinations of the commercial hydrator for 4h and commercial holding solution for 44h. Floral foam reduced vase life to 17 days from 23 days for the control treatment. The growth regulators gibberellin plus benzyladenine (GA4+7 + BA) had a positive effect on the fresh weight keeping parameter, but further studies are necessary. STS did not improve vase life, nor did ethylene at 1 µL L-1 reduce it. The curcuma cultivars tested were not positively affected by vase solution composition and had an average vase life in deionized water of 21 days

    Cádmio e a atividade de peroxidase durante a germinação de sementes de feijoeiro

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    Seeds of common bean seeds cv. Carioca were germinated in the dark in different concentrations of cadmium (1, 2, 5 and 10 mumol L-1) and collected after 24, 48, 72 and 96 hours with the objective of verifying if theperoxidase activity could be used as a biochemical marker of stress induced by cadmium. Alterations in the peroxidase activity (EC 1.11.1.7) were oberved in the cotyledons as well as in roots, as a function of the exhibition time of seeds in different cadmium concentrations. This enzyme can be used as a stress marker caused by cadmium during bean seed germination as an indicative of possible injure of the seeds by this metal.Sementes de feijoeiro cv. Carioca, foram germinadas no escuro em diferentes concentrações de cádmio (1, 2, 5 e 10 mimol L-1) e coletadas após 24, 48 , 72 e 96 horas com o objetivo de verificar se a atividade da peroxidase, poderia ser utilizada como marcador bioquímico de estresse promovido pelo cádmio. Observaram-se alterações na atividade específica da peroxidase (EC 1.11.1.7) tanto nos cotilédones como nas raízes, em função do tempo de exposição das sementes nas diferentes concentrações de cádmio. A enzima peroxidase (EC 1.11.1.7) pode ser usada como um indicador de estresse causado pelo cádmio durante a germinação de sementes de feijão, indicando possíveis injúrias causadas nas sementes pelo metal

    POLIAMINAS COMO MARCADORES BIOQUÍMICOS DE SALINIDADE EM CALOS DE Eucalyptus urograndis

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    Marcadores bioquímicos têm sido usados na análise de plantas submetidas a vários tipos de estresse, entre eles a salinidade. Este trabalho teve como objetivo analisar o estresse salino em calos de Eucalyptus urograndis em relação ao conteúdo de poliaminas. Explantes (hipocótilos) obtidos de sementes foram inoculados em meio indutivo de calos e foram submetidos a diferentes níveis de NaCl e analisados aos 10, 20 e 30 dias de inoculação. As poliaminas livres foram extraídas, isoladas e quantificadas usando TLC (Cromatografia de Camada Delgada). O conteúdo de putrescina foi maior, enquanto que o conteúdo de espermidina apresentou decréscimo, em calos submetidos a condições salinas. Os resultados mostram que o acúmulo de putrescina está relacionado com a exposição a NaCl em calos de Eucalyptus urograndis. A diminuição do conteúdo de espermina pode ser usada como marcador bioquímico de calos de Eucalyptus sujeitos à salinidade

    Agronomic Factors Influencing Brassica Productivity and Phytochemical Quality

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    Agronomic practices and climatic factors affect the content and profile of phytochemicals. The effects of the environment, such as salinity, climate, and other abiotic factors, promote biochemical responses, inducing changes in the quantity and quality of polyphenol compounds, carotenoids, vitamins, glucosinolates, and polyamines, which are bioactive compounds. In plants, among the various functions, some phytochemicals can protect against biotic factors. Brassica vegetables are a source of several primary and secondary metabolism compounds, and they might be responsible for disease prevention. In addition, the increase of bioactive compounds in plant-based foods is important to the diet and consequently for the improvement of public health. In this chapter, we will point out the abiotic factors that affect the productive performance, quality, and chemical composition of different Brassica species and cultivars. We will also discuss its implications on plant protection and human health

    Effect of spermidine on ornamental bromeliad cultured in vitro

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    Plants of the ornamental bromeliad, Aechmea blanchetiana (Baker) L.B. Smith obtained from seeds germinated in vitro, were treated with spermidine (Spd) at various concentrations (0, 10, 50 and 250 μM) or in the presence of 1.07 mM α-naphthaleneacetic acid (NAA) + 22.20 mM 6-benzyladenine (BA) or 0 mM NAA + 0 mM 6-BA for shoot induction and 0, 1.07 and 5.37 mM of NAA for root induction. The number of shoots, fresh and dry weight of shoots on shoot induction and fresh and dry weight of shoots and roots on root induction, and activity of peroxidases were evaluated. Polyamine Spd was not effective on shooting induction, rooting, mass accumulation of fresh and dry weight and had no influence on the activity of the enzyme peroxidase, and had a deleterious effect on dry matter accumulation in the treatment for shooting induction. Spd improved the qualitative and quantitative responses of in vitro rhizogenesis of A. blanchetiana as compared to the free polyamine medium. Peroxidase activity was higher in leaves of plants subjected to shoot induction, with 6-BA+NAA. The exogenous spermidine did not have effect on peroxidase activity.Keywords: Bromeliad, micropropagation, peroxidase activity, polyamin

    Polyamine, peroxidase activity and total protein content during storage of bird-of-paradise

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    The present study was aimed to the determination of the effect of storage on some biochemical characteristics (PAs content, POX activity and total protein content) of flower tissue of bird-of-paradise. Flowers were selected and labeled, avoiding any mechanical damage, and randomly distributed in recipients for two postharvest trials. In the first experiment, flowers were placed in recipients containing tap water and stored in a cold room, at 7.5 \ubaC and 90 % RH, for a period of 12 days. In experiment 2, flowers were stored in room temperature for a period of 6 days. For biochemical characteristics, samples (sepals, petals, stems and bracts) from experiment 1 were collected at 0, 4, 8 and 12 days, and at 0, 2, 4 and 6 days for experiment 2. Results showed that flower bracts, stored at 7.5 \ub0C, presented a lower content of PAs (Put and Spd), when compared to samples stored at room temperature. In both experiments, a high content of PAs (Spm) was observed in flower tissues in relation to Put and Spd. An increase of POX activity was observed in sepals stored in the cold, and was related to PAs degradation during senescence. No differences in total protein content were observed between the two treatments. The present study provides numeric results on changes in level of PAs, POX activity and total protein during postharvest of bird-of-paradise

    Polyamines, Gelling Agents in Tissue Culture, Micropropagation of Medicinal Plants and Bioreactors

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    Currently, tissue cultures of species of agricultural importance have wide applicability in industrial production processes. Tissue culture is a name given to a set of techniques that allow the regeneration of cells, tissues and organs of plants, from segments of plant organs or tissues, using nutrient solutions in aseptic and controlled environment. This regeneration is based on the totipotency of plant cells. Totipotency is a capability indicating that plant cells, in different times, may express the potential to form a new multicellular individual. Tissue culture appears to be a good alternative to conventional propagation, requiring less physical space, with high multiplication rate, without incidence of pests and diseases during cultivation, and enabling higher control of the variables involved. Thus, in the in vitro environment, with the required stimuli and appropriate conditions, different cell types express different behaviors, possibly leading to cell multiplication and differentiation into a specific tissue, characterized by a form and a function, which may lead to the regeneration of a new individual

    Polyamines as salinity biochemical marker in callus of Eucalyptus urograndis.

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    Biochemical markers have been used for the analysis of plant cells submitted to several types of stress, among them salinity. This work aimed at analyzing the effect of saline stress in callus of Eucalyptus urograndis on polyamine contents. Explants (hypocotyls) obtained from seeds were inoculated in callus inductive medium, submitted to different levels of NaCl and analyzed at 10, 20 and 30 days after the inoculation. The free polyamines were extracted, isolated and quantified using TLC (Thin-Layer Chromatography). Putrescine content was higher and a fall in the spermidine content was observed in callus submitted to salinity condition. The results showed that polyamine accumulation is related to NaCl exposure in callus of Eucalyptus urograndis. The decrease in spermine content could be used as a biochemical marker for Eucalyptus callus subjected to salinity.Biochemical markers have been used for the analysis of plant cells submitted to several types of stress, among them salinity. This work aimed at analyzing the effect of saline stress in callus of Eucalyptus urograndis on polyamine contents. Explants (hypocotyls) obtained from seeds were inoculated in callus inductive medium, submitted to different levels of NaCl and analyzed at 10, 20 and 30 days after the inoculation. The free polyamines were extracted, isolated and quantified using TLC (Thin-Layer Chromatography). Putrescine content was higher and a fall in the spermidine content was observed in callus submitted to salinity condition. The results showed that polyamine accumulation is related to NaCl exposure in callus of Eucalyptus urograndis. The decrease in spermine content could be used as a biochemical marker for Eucalyptus callus subjected to salinity

    The Increase of Amines Content in the Intake of a Vegan Diet

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    Vegetarian and vegan consumers have increased in the last years. However, the food industry is facing problems responding to this growing market, since the food safety of several plant-based products is not well established. Fruits, vegetables and fermented products, such as nut and grains milks and cheeses, may be rich sources of biogenic amines; whereas, the levels of these compounds should be considered before the inclusion on a daily diet. Biogenic amines are a class of compounds with wide physiological activities as antioxidant properties, inductors of cell division and allergic processes, and sleep, sexual and behavioral disorders. In addition to the levels of biogenic amines, the levels of some of its precursors as tryptophan, 5-hydroxytryptophan and tryptamine will be presented. The foods eaten by vegans are consumed raw, cooked, fried, fermented and mainly through homemade processing methods, which have influence on the levels of bioactive compounds from the food matrix. Exposure to processing conditions such as handling, sanitary conditions, high temperatures, preparing methods (cooking in water or oil) influencing the levels of amines, will be discussed in this chapter to enrich the knowledge on food safety associated to vegan diets

    Inhibition of ethylene action delay chilling injury development in tangor 'Murcott'

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    O bloqueio de eventos dependentes da sinalização do etileno pode afetar de maneira positiva ou negativa a qualidade de frutos tropicais após o armazenamento refrigerado. Dessa forma, os objetivos do presente trabalho foram estudar o envolvimento do etileno no desenvolvimento de injúrias de frio em tangor 'Murcott' e avaliar as respostas envolvidas no processo de resistência às injúrias. Os frutos foram expostos a 500nL L-1 de 1-metilciclopropeno (1-MCP) durante 12 horas ou imersos em soluções contendo 2000nL L-1 de ethephon ou ácido salicílico durante cinco minutos antes de serem armazenados a 1°C, por 90 dias. Como controle, parte dos frutos foi armazenada a 1°C. O tratamento de frutos com ethephon ou ácido salicílico antecipou e intensificou as injúrias de frio. Por outro lado, a inibição do etileno pelo 1-MCP retardou o surgimento dos sintomas e resultou em menor índice de injúrias e percentual de frutos podres ao final do armazenamento. A atividade da superóxido dismutase (SOD) foi intensificada aos 45 dias, contudo em menor intensidade nos frutos tratados com ácido salicílico. Nas avaliações subsequentes, houve decréscimo na atividade da SOD em todos os tratamentos, porém aos 90 dias a intensidade manteve-se levemente superior à observada nos primeiros 30 dias de armazenamento. Os teores de putrescina (Put) e espermina (Spm), no flavedo dos frutos, não sofreram significativa alteração durante o armazenamento. Em contrapartida, os teores de espermidina (Spd) foram mais afetados pelo estresse ocasionado pelo frio.The blockage of ethylene-dependent signaling may affect the quality of tropical fruit in a positive or negative way after cold storage. Hence, the role of ethylene on chilling injury in tangor 'Murcott' and the responses related to injuries resistance were the aims of this study. Fruit were treated for 12h with 500nL L-1 of 1 methylcyclopropene (1-MCP) or immersed into solutions containing 2000nL L-1 ethephon or salicylic acid for 5min before storage at 1°C for 90 days. As a control fruit were stored at 1°C. Chilling injury symptoms were anticipated and intensified when fruit were treated with ethephon or salicylic acid. On the other hand, the ethylene inhibition by 1-MCP delayed symptoms and resulted in the lowest injury index and percentage of fruit decay at the end of storage. At 45 days the superoxide dismutase (SOD) activity was intensified, however, in lower intensity in salicylic acid treated fruit. Afterwards, SOD activity decrease in all the treatments, though at 90 days the intensity was slightly superior to that at the initial 30 days of storage. During storage period it were not observed significantly alterations in putrescine (Put) and spermine (Spm) levels in flavedo tissues. In contrast, spermidine (Spm) levels were more affected by chilling stress
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