Compostos ativos de folhas de Eugenia uniflora e seus efeitos contra mofo branco causado por Sclerotinia sclerotiorum em plantas de feijoeiro

• Autor(a) principal: Marques, Jacqueline Santos
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/5566
• topic: Flavonoides; Elicitores de defesa; Phaseolus vulgaris; Mofo branco; Flavonoids; Elicitors of defense; Phaseolus vulgaris; White mold; CIENCIAS BIOLOGICAS

The extracts and essential oils from plants are bioactive molecules of interest to resistance induction in plants and the control of plant pathogens. The aim this study was to evaluate the effect of the ethanol extract and essential oil from leaves of Eugenia uniflora and two commercial flavonoid fractions, quercetin and rutin, as bioactive compounds for the control of white mold, caused by the fungus Sclerotinia sclerotiorum in common bean (Phaseolus vulgaris L.). The compounds were tested against pathogen through the mycelial growth, cell viability, sclerotia formation, cell morphology and biochemical aspects. And on the pathossystem Phaseolus vulgaris-Sclerotinia sclerotiorum was evaluated biochemical and molecular aspects (RT-qPCR) involved in the mechanism of plant defense, into a kinetic treatment and infection (12, 24 e 48 hours). The data show that the tested compounds were significantly relevant (P<0.01) to growth inhibition pathogen’s mycelium and cell viability in vitro and in the formation of sclerotia of the pathogen a positive correlation between percent inhibition and the concentration of active compounds applied was observed. The minimum inhibitory concentration (MIC) for S. sclerotiorum was 0.6% (v/v) ethanol extract of leaves from E. uniflora and the 100 ppm of the essential oil. In Bioassays in plants, the treatment with ethanol extract or essential oil from Eugenia uniflora and rutin inhibited the formation of necrotic area in common bean leaves 48 hours after inoculation. Biochemical analysis showed that the compounds induced 12 hours after treatment the activation of key proteins related to plant defense, chitinases, β-1,3- glucanase, phenylalanine ammonia lyase, peroxidases and polyphenoloxidases. Molecular analysis showed that treatment with ethanolic extract, quercetin and rutin in healthy plants activated pathogenesis-related genes (PRs) at different times into the kinetic treatment, and that these genes are highly expressed in plants infected compared to the pretreated and infected plants. The results of this research suggest that the effects of the ethanol extract, flavonoids and oil from Eugenia uniflora are potential bioactive molecules to reduce the severity of disease white mold in bean leaves.