Liliane Evangelista Visôtto
Universidade Federal de Viçosa
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Featured researches published by Liliane Evangelista Visôtto.
Journal of Insect Physiology | 2009
Liliane Evangelista Visôtto; Maria Goreti de Almeida Oliveira; R.N.C. Guedes; A.O.B. Ribon; P.I.V. Good-God
Bacteria colonies from gut homogenates of fifth instar velvetbean caterpillars (Lepidoptera: Noctuidae) were subjected to antibiotic sensitivity experiments using discs containing 22 antibiotics. The antibiotic tetracycline provided the best results, followed by chloramphenicol. Tetracycline also provided higher inhibition of colony forming units than chloramphenicol and was therefore provided to the caterpillars in increasing diet concentrations to assess the contribution of gut bacteria to their digestion and development. The activity of proteases (general), serine-proteinases and lipases were significantly suppressed by tetracycline. Concentration-inhibition curves were successfully established for tetracycline and this antibiotic was effective in suppressing them, particularly serine-proteinases, suggesting that gut bacteria may significantly contribute with lipid- and mainly protein-digestion in velvetbean caterpillars. Increased diet concentrations of tetracycline led only to mild increase in insect mortality (ca. 20%), with the surviving insects showing faster development (< or =4 days) and higher pupa weight (<0.04 mg) with increased concentrations of tetracycline. Therefore, the gut bacteria inhibited by tetracycline does not seem to play a crucial role in the survival and development of the velvetbean caterpillar, but may be important in the adaptation of this pest species to hosts rich in protease inhibitors, such as soybean.
Journal of Comparative Physiology B-biochemical Systemic and Environmental Physiology | 2013
Franciny Martins Pilon; Liliane Evangelista Visôtto; Raul Narciso C. Guedes; Maria Goreti de Almeida Oliveira
The development of proteinase inhibitors as potential insect control agents has been constrained by insect adaptation to these compounds. The velvet bean caterpillar (Anticarsia gemmatalis) is a key soybean pest species that is well-adapted to proteinase inhibitors, particularly serine-proteinase inhibitors, which are abundant in the caterpillar host. The expression of diverse proteolytic enzymes by gut symbionts may allow the velvet bean caterpillar to circumvent proteinase inhibitors produced by the host plant. In this study, we characterized the proteolytic activity of the four nonpathogenic species of gut bacteria isolated from the velvet bean caterpillar—Bacillus cereus, Enterococcus gallinarum, Enterococcus mundtii and Staphylococcus xylosus. Two proteinase substrates, N-α-benzoyl-l-Arg-p-nitroanilide (l-BApNA) and N-α-p-tosyl-l-Arg methyl ester (l-TAME) and five proteinase inhibitors [aprotinin, E-64, ethylenediamine tetraacetic acid (EDTA), pepstatin and N-α-tosyl-l-lysine chloromethyl ketone (TLCK)] as well as CaCl2, pH and temperature profiles were used to characterize the expressed proteolytic activity of these bacterial strains in vitro. Kinetic parameters for proteolytic activity were also estimated. The results of these experiments indicated that serine- and cysteine-proteinase activities were expressed by all four gut bacteria symbionts of the velvet bean caterpillar. The cysteine- and serine-proteinase activities of these gut symbionts were distinct and different from that of gut proteinases of the caterpillar itself. This finding provides support for the potential involvement of gut symbionts in the mitigation of the negative effects of serine-proteinase inhibitors in the velvet bean caterpillar.
Idesia (arica) | 2016
Gilson Petrônio Paixão; André Luiz Lourenção; Camila Rocha Silva; Gláucia Cordeiro; Rafael de Almeida Barros; Joel Antônio de Oliveira; Liliane Evangelista Visôtto; Maria Goreti de Almeida Oliveira
Los mecanismos de resistencia endogenos de las plantas contra insectos herbivoros pueden permitir el desarrollo de estrategias alternativas para el control de plagas. La activacion de la via de las lipoxigenasas con la produccion de acido jasmonico, hormona responsable por la activacion de los genes inhibidores de proteasa, es una de las principales formas de defensa directa de las plantas contra los insectos. En el presente estudio, cultivares de soya en estadio V3, susceptibles y resistentes a insectos herbivoros fueron utilizadas para investigar las alteraciones en la actividad de LOX y la concentracion de PIs, en respuesta al ataque de orugas en cuarto y quinto instar de Anticarsia gemmatalis (Lepidoptera: Noctuidae) por 24 y 48 horas. La actividad de LOX (0,00 a 0,007 nm s-1/mg) y la concentracion de inhibidores de proteasa (60 a 125 mg de inhibidor de tripsina/ mg de proteina y 90 a 120 mg de inhibidor de tripsina/mg de proteina despues de 24 y 48 horas del ataque respectivamente) aumenta en respuesta a los danos ocasionados por A. gemmatalis. La actividad proteolitica disminuyo aproximadamente en 50% en los cultivares con diferentes grados de resistencia. El aumento del perfil enzimatico del intestino medio de A. gemmatalis puede estar relacionado al aumento de las enzimas tripticas para compensar la inhibicion de proteasas por sustancias entomotoxicas de los cultivares de soya.
Archives of Insect Biochemistry and Physiology | 2017
Franciny Martins Pilon; Camila Rocha Silva; Liliane Evangelista Visôtto; Rafael de Almeida Barros; Neilier Rodrigues da Silva Júnior; Wellington G. Campos; Maria Goreti de Almeida Oliveira
Purification of active trypsin in the digestive process of insects is essential for the development of potent protease inhibitors (PIs) as an emerging pest control technology and research into insect adaptations to dietary PIs. An important aspect is the presence of proteolytic microorganisms, which contribute to host nutrition. Here, we purified trypsins produced by bacteria Bacillus cereus, Enterococcus mundtii, Enterococcus gallinarum, and Staphylococcus xylosus isolated from the midgut of Anticarsia gemmatalis. The trypsins had a molecular mass of approximately 25 kDa. The enzymes showed increased activity at 40°C, and they were active at pH values 7.5-10. Aprotinin, bis-benzamidine, and soybean Kunitz inhibitor (SKTI) significantly inhibited trypsin activity. The l-1-tosyl-amido-2-phenylethylchloromethyl ketone (TPCK), pepstatin A, E-64, ethylenediamine tetraacetic acid, and calcium ions did not affect the enzyme activity at the concentrations tested. We infer the purified trypsins do not require calcium ions, by which they differ from the trypsins of other microorganisms and the soluble and insoluble trypsins characterized from A. gemmatalis. These data suggest the existence of different isoforms of trypsin in the velvetbean caterpillar midguts.
Journal of Pest Science | 2012
Eduardo Gomes de Mendonça; Maria Goreti de Almeida Oliveira; Liliane Evangelista Visôtto; Raul Narciso C. Guedes
The Journal of Engineering and Exact Sciences | 2018
Vinícius Guimarães Nasser; Samarina Gabriele de Fátima Pereira; Liliane Evangelista Visôtto; Manuela Pereira Souto; Regiane Victória de Barros Fernandes; Márcio Santos Soares; Fernanda Santiago Chaves Soares; Mariana Rocha Roswell; Camila Miwa Hanzawa; Inêz De Fátima Martins Oliveira
Crop Protection | 2018
Darlan Ferreira Borges; Everaldo Antônio Lopes; Allan Robledo Fialho e Moraes; Márcio Santos Soares; Liliane Evangelista Visôtto; Cassiano Rodrigues de Oliveira; Vânia Maria Moreira Valente
Ciencia Rural | 2018
Tiago Garcia da Cunha; Liliane Evangelista Visôtto; Everaldo Antônio Lopes; Claudio Marcelo Gonçalves de Oliveira; Pedro Ivo Vieira Good God
The Journal of Engineering and Exact Sciences | 2017
Samara Aparecida Cardoso Alves de Sá; Simão Pedro de Oliveira Júnior; Milene Therezinha das Dores; Liliane Evangelista Visôtto; Camila Rocha da Silva
Archive | 2016
Anderson Martins Pilon; Liliane Evangelista Visôtto; Camila Rocha Silva; Maria Goreti de Almeida Oliveira