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Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2004. / Härtill 5 uppsatser.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.

Lic.-avh. Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 2 uppsatser. Felaktigt institutionsnamn i publikationen. Rätt namn: Department of Entomology.

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniversitet, 2006. / Härtill 3 uppsatser.

Orientador: Edson Luis Maistro / Resumo: A Salix alba L. (SA), popularmente conhecida como Salgueiro Branco, é uma planta utilizada na medicina popular para o tratamento de inflamações crônicas e agudas, infecções, dores, febre, entre outros. A caracterização fitoquímica do extrato da casca desta planta revelou que seu principal componente é a salicina, com uma concentração de 4,94 mg/mL, um precursor do anti-inflamatório ácido acetilsalicílico. Considerando que existem poucos estudos que avaliam a ação tóxica e citotóxica do extrato da SA, o presente estudo foi elaborado visando investigar o potencial citotóxico, genotóxico e mutagênico da SA em células mononucleares do sangue periférico humano e de hepatocarcinoma humano HepG2 in vitro, e em diferentes células de camundongos in vivo, utilizando alguns dos testes tradicionais na área de mutagênese, como o teste do MTT, o Ensaio do Cometa e o Teste do Micronúcleo, bem como a verificação de potencial citotoxicidade por meio de análises histológicas e histoquímicas. Os testes de viabilidade celular e citotoxicidade (azul de tripan e MTT) permitiram a escolha de 3 concentrações do extrato da SA para serem analisadas nos ensaios de genotoxicidade in vitro: 5, 50 e 100 µg/mL. Pelo ensaio cometa com as células mononucleares de sangue periférico, pôde-se observar que as concentrações de 50 e 100 µg/mL acarretaram um aumento estatisticamente significativo de danos no DNA, em comparação ao controle negativo. Já no teste do micronúcleo, as 3 concentrações avaliadas (5, 50 e 1... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Salix alba L. (SA), popularly known as White Willow, is a plant used in folk medicine for the treatment of chronic and acute inflammations, infections, pains, fever, among others. The phytochemical characterization of the bark extract of this plant revealed that its main component is salicin, with a concentration of 4.94 mg/mL, a precursor of the antiinflammatory acetylsalicylic acid. Considering that there are few studies evaluating the toxic and cytotoxic action of SA extract, the present study was designed to investigate the cytotoxic, genotoxic and mutagenic potential of SA bark wood extract in human peripheral blood mononuclear cells and human hepatoma cell line HepG2 in vitro and in different mouse cells in vivo using some of the traditional mutagenesis tests such as the MTT test, the Comet assay and the Micronucleus test, and cytotoxicity in the liver of mice also by histological and histochemical analysis. Cell viability and cytotoxicity tests (trypan blue and MTT) allowed the choice of 3 concentrations of the SA extract to be analyzed in the in vitro genotoxicity assays: 5, 50 and 100 μg/mL. By the comet assay with the peripheral blood mononuclear cells, it was observed that concentrations of 50 and 100 μg/ml resulted in a statistically significant increase in DNA damage, as compared to the negative control. In the micronucleus test, the 3 concentrations evaluated (5, 50 and 100 μg/mL) did not produce significant increases of micronucleated binucleate cells, as well ... (Complete abstract click electronic access below) / Doutor

The aim of this dissertation is to investigate what role insect-plant interactions play in the formation of host-plant defenses and in the diversification of both groups. We show that various groups of herbivore respond differently to host-plant defenses. Therefore plant defenses diversify into suites of complementary traits, as individual traits fail to provide protection against specialized herbivores. Further, we identify what levels of host-phylogeny shape the food-web structure of insect herbivores. We show that specialized herbivores are affected mainly by the terminal parts of the host-phylogeny. In contrast, more polyphagous guilds are affected mainly by the mid-levels of the host phylogeny because the effects of terminal or deeper phylogeny seem to be surpassed by other factors in more generalist insect species. In the last chapter, we show how specialized insect-plant interactions generated by tight insect-plant coevolution can influence the speciation in plants over environmental gradients.

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Mon projet de maîtrise avait pour but d’évaluer la faisabilité d’une solution de phytoremédiation par phyto-extraction d’un sol modérément contaminé en zinc et en arsenic. Cette évaluation s’est basée sur les résultats d’une expérience en pots réalisée dans un tunnel de croissance de l’Institut de recherche en biologie végétale (IRBV) durant l’été 2015. Le sol utilisé provenait directement du site contaminé. Les plantes choisies pour cette expérience étaient deux cultivars de saule, Salix purpurea ‘Fish Creek’ et Salix miyabeana ‘SX67’ ainsi que trois herbacées Medicago sativa, Festuca arundinacea et un mélange de plantes utilisé pour la stabilisation de sol. L’impact d’un agent chélateur (acide nitrilotriacétique, NTA) sur la phytoremédiation et le développement des espèces a également été étudié. Les saules ont extrait deux à trois fois plus de zinc que les herbacées. La tendance était inversée pour l’arsenic avec une extraction deux à trois fois plus grande chez les herbacées. Le chélateur NTA a eu un effet positif sur la biomasse aérienne des plantes et sur la phyto-extraction du zinc, mais pas sur la phyto-extraction de l’arsenic. Une diminution importante de la quantité de zinc et d’arsenic a été observée dans les sols. Cette diminution provient des effets combinés de la phyto-extraction et d’autres facteurs, comme la variabilité intrinsèque du sol ainsi que son lessivage. La phyto-extraction de l’arsenic a donné des résultats médiocres, quels que soient les traitements et les plantes utilisés. Les résultats obtenus démontrent l’efficacité des saules et le potentiel du chélateur NTA pour la phyto-extraction du zinc. / My master project aimed to evaluate if phytoremediation by phytoextraction was a viable solution in cleaning up a moderately contaminated soil in zinc and arsenic. This evaluation was based on the results of a potted experiment done within Montreal Botanical Garden, in a growth tunnel set up by Institut de recherche en biologie végétale (IRBV). The soil was collected from a contaminated site. We chose the following plants species: two willow cultivars, Salix purpurea ‘Fish Creek’ and Salix miyabeana ‘SX67’, two grasses Medicago sativa L., Festuca arundinacea and a mix of grasses used for soil stabilization. The impact of a chelating agent (nitrilotriacetic acid, NTA) on phytoextraction and plant growth was also assessed. Salix extracted two to three time more zinc than the grasses. For arsenic, the opposite trend was observed, with two to three times more arsenic extracted by grasses. Chelator NTA had a positive effect on above ground biomass and overall phytoextraction of zinc, but not for arsenic phytoextraction. A significant diminution of zinc and arsenic was observed in soil after the experiment. This diminution comes from the combined effects of phytoextraction and other factors, such as intrinsic soil variability and its leaching. Arsenic phytoextraction was overall mediocre regardless of the species and treatments used. These results show the effectiveness of willows and potential from chelator NTA for zinc phytoextraction.