Characterisation, immunolocalisation and antifungal activity of a lipid transfer protein from chili pepper (Capsicum annuum) seeds with novel alpha-amylase inhibitory properties

Lipid transfer proteins (LTPs) were thus named because they facilitate the transfer of lipids between membranes in vitro. This study was triggered by the characterization of a 9-kDa LTP from Capsicum annuum seeds that we call Ca-LTP(1). Ca-LTP(1) was repurified, and in the last chromatographic purification step, propanol was used as the solvent in place of acetonitrile to maintain the protein`s biological activity. Bidimensional electrophoresis of the 9-kDa band, which corresponds to the purified Ca-LTP(1), showed the presence of three isoforms with isoelectric points (pIs) of 6.0, 8.5 and 9.5. Circular dichroism (CD) analysis suggested a predominance of alpha-helices, as expected for the structure of an LTP family member. LTPs immunorelated to Ca-LTP(1) from C. annuum were also detected by western blotting in exudates released from C. annuum seeds and also in other Capsicum species. The tissue and subcellular localization of Ca-LTP(1) indicated that it was mainly localized within dense vesicles. In addition, isolated Ca-LTP(1) exhibited antifungal activity against Colletotrichum lindemunthianum, and especially against Candida tropicalis, causing several morphological changes to the cells including the formation of pseudohyphae. Ca-LTP(1) also caused the yeast plasma membrane to be permeable to the dye SYTOX green, as verified by fluorescence microscopy. We also found that Ca-LTP(1) is able to inhibit mammalian alpha-amylase activity in vitro.

Growth analysis of sweet pepper cultivated in coconut fiber in a greenhouse

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

Macronutrient accumulation and partioning in fertigated sweet pepper plants

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

A classification of Pepper yellow mosaic virus isolates into pathotypes

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

Dehydration of dedo de moça pepper: kinetics and phytochemical concentration

A pimenta vermelha é rica em vitamina C e outros fitoquímicos e pode ser consumida como produto desidratado. A avaliação das melhores condições de secagem pode garantir melhor qualidade do produto. Assim, o objetivo deste trabalho foi estudar o efeito da temperatura do ar de secagem (55, 65, 75 ºC) sobre a cinética de secagem, conteúdos de vitamina C e fenólicos totais e cor do produto desidratado, comparando-os à pimenta in natura. A desidratação foi feita por convecção forçada em estufa. A cinética de secagem foi determinada por pesagens periódicas até peso constante. A umidade da pimenta in natura foi de aproximadamente 86%. As curvas de secagem foram ajustadas por três modelos diferentes, avaliados na literatura. O modelo de Page apresentou o melhor ajuste para este processo. A análise de variância mostrou que a temperatura de secagem influenciou significativamente (p < 0,05) os parâmetros de qualidade (conteúdo de vitamina C, conteúdo de fenólicos totais, cor) da pimenta desidratada quando comparados aos da pimenta in natura. Após a secagem, a retenção de vitamina C aumentou com a redução da temperatura de secagem. de maneira geral, a qualidade do produto foi favorecida na secagem com menor temperatura, devido à redução nas perdas de compostos bioativos.

Breakdown of resistance in sweet pepper against Pepper yellow mosaic virus in Brazil

Plantas de Capsicum annuum cv. Magali R, resistentes ao Pepper yellow mosaic virus (PepYMV), exibindo sintomas severos de mosaico amarelo, malformação foliar e subdesenvolvimento foram encontradas em plantios na região de Lins, SP, Brasil, em 2003/04. Partículas semelhantes àquelas do gênero Potyvirus foram observadas em extrato foliar de planta infectada examinado em microscópio eletrônico de transmissão. O extrato foliar também reagiu com anti-soro contra o PepYMV em PTA-ELISA. Além de C. annuum cv. Magali R, esse potyvirus também infectou sistemicamente C. annuum cv. Rubia R, que é resistente ao PepYMV. A seqüência de nucleotídeos de parte do gene da proteína capsidial (CP) desse potyvirus apresentou 96-98% de identidade com a de outros isolados do PepYMV. A seqüência parcial de nucleotídeos da região 3' não traduzida (3' NTR) apresentou 94-96% de identidade com a do PepYMV. Esses resultados são indicativos de que o potyvirus que quebrou a resistência em pimentão é um isolado do PepYMV.

Damages occurrence and determination of dasineura Sp. (Díptera: Cecidomyiidae) in the pepper cultivars (Capsicum annuum L.) in piracicaba Sp.

The purpose of this study was to evaluate the damage potential of Dasineura sp. (Diptera: Cecidomyiidae) in the pepper cultivars and show its occurrence in Piracicaba, SP. This experiment was carried out from July to November 1998. The occurrence and damages pest in the fruits were determined by weekly evaluations of pepper hybrids, 'Magali R.' larvals were collected from floral buttons and adults were collected from the incubation of buttons in humidity chamber. Healthy and infested fruits were evaluated for damages caused by pest insects. The results indicated that the damages can reach 100% in some periods of evaluation and that the production losses are significantly high with no application of insecticides. The taxonomy study was performed at National Museum of Federal University of Rio de Janeiro (UFRJ). The insect species classification will be the object of study since there is a possibility of observing a specie not described yet.

Peroxidase enzyme (EC.1.11.1.7) activity as an indicator of water stress in sweet pepper plants

The present work was carried out at the Faculdade de Ciências Agronômicas - UNESP, Botucatu, SP. The purpose of the study was to evaluate the physiological and biochemical behavior of sweet pepper (Capsicum annuum L.) plants under different soil water availability conditions and the efficiency of the peroxidase (EC. 1.11.1.7) activity as an indicator of water stress in plants. Sweet pepper plants were grown for 230 days after transplanting of seedlings. The experiment was arranged in a completely randomized experimental design with 4 treatments, two irrigation managements (50 and 1500 kPa) and two soil surface managements (presence or absence of black polyethylene covering), and six replications. Physiological activities, such as stomatal transpiration and resistance to water vapor diffusion, were evaluated, as well as biochemical activities, such as peroxidase activity and total soluble protein in foliar tissues. It was observed that soil water availability may lead to physiological and biochemical alterations in plants. Successive water stress cycles may promote the development of characteristics responsible for improving the plant tolerance to periods of low water availability. The peroxidase enzyme activity showed to be an efficient indicator of water stress in sweet pepper plants.

Peroxidase activity as an indicator of water stress in sweet pepper plants

The purpose of the study was to evaluate the physiological and biochemical behavior of sweet pepper (Capsicum annuum L.) plants under different soil water availability conditions and the efficiency of the peroxidase (EC. 1.11. 1.7) activity as an indicator of water stress in plants. The experiment was carried out at the Faculdade de Ciências Agronômicas UNESP, Botucatu, SP. Sweet pepper plants were grown for 230 days after transplanting of seedlings and arranged in a completely randomized experimental design with 4 treatments, two irrigation managements (50 and 1500 kPa) and two soil surface managements (presence or absence of black polyethylene covering), and six replications. Physiological activities, such as stomatal transpiration and resistance to water vapor diffusion, were evaluated as well as biochemical activities, such as peroxidase activity and total soluble protein in foliar tissues. It was observed that soil water availability may lead to physiological and biochemical alterations in plants. Successive water stress cycles may promote the development of characteristics responsible for improving plant tolerance to periods of low water availability. The peroxidase enzyme activity showed to be an efficient indicator of water stress in sweet pepper plants.

Determination of tetradifon in brazilian green bell pepper by differential pulse voltammetry

Tetradifon, a potentially carcinogenic and mutagenic pesticide, can contribute to environmental and human contamination when applied to green bell pepper crops. In this context, in this work, a reliable and sensitive method for determination of tetradifon in Brazilian green bell pepper samples involving a differential pulse voltammetry (DPV) technique on a glassy carbon electrode is proposed. The electrochemical behavior of tetradifon as followed by cyclic voltammetry (CV) suggests that its reduction occurs via an irreversible five–electron transfer vs. Ag|AgCl, KCl 3 M reference electrode. Very well–resolved diffusion controlled voltammetric peaks have been obtained in a supporting electrolyte solution composed of a mixture of 40% dimethylformamide (DMF), 30% methanol, and 30% NaOH 0.3 mol L−1 at −1.43, −1.57, −1.73, −1.88, and −2.05 V. The proposed DPV method has a good linear response in the 3.00 – 10.0 μmol L−1 range, with a limit of detection (L.O.D) of 0.756 μmol L−1 and 0.831 μmol L−1 in the absence and in the presence of the matrix, respectively. Moreover, improved L.O.D results (0.607 μmol L−1) have been achieved in the absence of DMF from the supporting electrolyte solution. Recovery has been evaluated in five commercial green bell pepper samples, and recovery percentages ranging from 91.0 to 109 have been obtained for tetradifon determinations. The proposed voltammetric method has also been tested for reproducibility, repeatability, and potential interferents, and the results obtained for these three analytical parameters are satisfactory for electroanalytical purposes.

Morphologic characterization of spiked pepper's germplasm

Pimenta-de-macaco é uma espécie que possui propriedades que permitem o desenvolvimento de defensivos agrícolas naturais e medicamentos, apresentando, portanto, grande potencial de uso pela humanidade. Com o objetivo de determinar a variabilidade fenotípica, foram estudadas 41 matrizes amostradas nos Estados do Pará e Amazonas. Utilizou-se análises de componentes principais e critério de Jolliffe para descarte de variáveis, subsidiado pela correlação de Pearson. Foram necessários sete componentes para explicar 80% da variação. O rendimento de óleo essencial e o número de folhas por ramo foram sugeridos para descarte por serem as características que menos contribuíram para a variação total. A dispersão gráfica 3D formou um grupo relativamente homogêneo e contínuo, permitindo identificar um par divergente: PA-020 (Marabá-PA) e PA-035 (Santa Isabel-PA). Concluiu-se que os caracteres analisados possuem variabilidade potencialmente capaz de discriminar as matrizes, com 83,3% de tais caracteres podendo ser utilizados para este objetivo. Os genótipos divergentes, identificados na análise gráfica 3D, podem ser usados em programas de melhoramento para obtenção de genótipos superiores. A comparação com os dados moleculares, previamente existentes, de alguns desses genótipos permite concluir, também, que a caracterização molecular, apesar de apresentar certo grau de concordância com a caracterização morfológica, teve maior poder discriminatório, utilizando um menor número de genótipos e procedências, identificando grupos dissimilares e genótipos divergentes, embora analisado por método estatístico multivariado diferente.