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Browsing CIMO by Author "Abdellaziz, Omar"
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- Characterization of ligninolytic enzymes and metabolic profile of Cryphonectria parasitica and the isogenic converted strains by CHV1 hypovirusPublication . Abdellaziz, Omar; Jorge, Lurdes; Moura, Luísa; Coelho, Valentim; Gouveia, Maria EugéniaCryphonectria parasitica, the causal agent of chestnut blight, causes necrotic lesions (so-called cankers) on the bark of stems and branches of susceptible host trees. Cryphonectria Hypovirus 1 (CHV1) infects C. parasitica and reduces the fungus virulence (hypovirulence) and alters the fungus morphology in culture (pigmentation and sporulation capacity). By this characteristics the mycovirus CHV1 is used in Europe as a biological control agent of Chestnut Blight.The aim of this project is to better understand the effect of the mycovirus on the fungi pathogenicity by comparing the production of some lignin degrading enzymes and the metabolic profiles of some virulent and hypovirulent (converted and original) strains. For qualitative evaluation, several different compounds have been used as indicators for ligninolytic enzymes production. For quantitative evaluation, among 9 strains 5 were chosen for biological tests and cultivation in minimal liquid media and the amount of enzyme produced were analysed. Virulent strains were found to cause more damage in chestnut branches and to produce more lignin degrading enzymes. In apple fruits, some CHV1 strains produced bigger rot lesions than wild type strains did. In parallel, Biolog FF MicroPlates have been used for the first time with Cryphonectria parasitica to assess their metabolic profiles by the utilization of 95 different carbon sources. Carbohydrates, amino acids, amines/amides, miscellaneous and polymers were found to be more consumed by hypovirulent strains; therefore, this may suggest. an adaptation in this fungal strains ecology and field fitness.
- Characterization of ligninolytic enzymes and metabolic profile of cryphonectria parasitica and the isogenic converted strains by CHV1 hypovirusPublication . Abdellaziz, Omar; Jorge, Lurdes; Moura, Luísa; Coelho, Valentim; Gouveia, Maria EugéniaCryphonectria parasitica, the causal agent of chestnut blight, causes necrotic lesions (so-called cankers) on the bark of stems and branches of susceptible host trees. Cryphonectria Hypovirus 1 (CHV1) infects C. parasitica and reduces the fungus virulence (hypovirulence) and alters the fungus morphology in culture (pigmentation and sporulation capacity). By this characteristics the mycovirus CHV1 is used in Europe as a biological control agent of Chestnut Blight.The aim of this project is to better understand the effect of the mycovirus on the fungi pathogenicity by comparing the production of some lignin degrading enzymes and the metabolic profiles of some virulent and hypovirulent (converted and original) strains. For qualitative evaluation, several different compounds have been used as indicators for ligninolytic enzymes production. For quantitative evaluation, among 9 strains 5 were chosen for biological tests and cultivation in minimal liquid media and the amount of enzyme produced were analysed. Virulent strains were found to cause more damage in chestnut branches and to produce more lignin degrading enzymes. In apple fruits, some CHV1 strains produced bigger rot lesions than wild type strains did. In parallel, Biolog FF MicroPlates have been used for the first time with Cryphonectria parasitica to assess their metabolic profiles by the utilization of 95 different carbon sources. Carbohydrates, amino acids, amines/amides, miscellaneous and polymers were found to be more consumed by hypovirulent strains; therefore, this may suggest. an adaptation in this fungal strains ecology and field fitness.
- Virulência, enzimas lenhinolíticas e perfil metabólico de cryphonectria parasitica em estirpes virulentas e hipovirulentas convertidas por CHV1 hipovirusPublication . Abdellaziz, Omar; Jorge, Lurdes; Moura, Luísa; Coelho, Valentim; Gouveia, Maria EugéniaCryphonectria parasitica, fungo responsável pelo cancro do castanheiro, causa lesões necróticas (cancros corticais) no tronco e ramos das árvores hospedeiras. O hipovírus, Cryphonectria hypovirus 1 (CHV1) reduz a virulência (hipovirulência) e altera a morfologia do fungo em cultura (redução da pigmentação e esporulação). As estirpes hipovirulentas CHV1 são utilizadas com sucesso na Europa como agentes de controlo biológico do Cancro do castanheiro. Objetivos: O objetivo deste trabalho foi compreender o efeito do hipovírus na virulência e metabolismo do fungo, comparando a produção de algumas enzimas lenhinolíticas e os perfis metabólicos de estirpes virulentas e estirpes isogénicas de C. parasitica convertidas (com CHV1). Métodos: A virulência de cada isolado foi avaliada por inoculação de micélio do fungo em maçãs (cv. Golden Delicious) e em ramos destacados de castanheiro com um ano de crescimento. Para a deteção da atividade de enzimas lenhinolíticas (lacases, peroxidases e celulases) foram usados vários substratos e compostos indicadores. O perfil metabólico de C. parasitica foi avaliado pelo sistema Biolog FF microplates pela utilização de 95 fontes diferentes de carbono. Resultados: A utilização de MicroPlacas FF (Biolog, Inc.) indicaram que a utilização de 95 fontes de carbono pelos cinco isolados de C. parasitica, foram significativamente diferentes (p <0,001), quando os substratos foram agrupados em seis tipos de compostos químicos. Os maiores valores de AWCD foram obtidos para os hidratos de carbono, ácidos carboxílicos e polímeros, e os menores valores para os grupos aminas / amidas, aminoácidos e compostos diversos. Conclusões: A avaliação da virulência de isolados de C. parasitica é importante para o estudo dos processos de hipovirulência mediados pelo hipovírus CHV1. Os ramos destacados de castanheiro foram, em nosso estudo, mais adequados que o teste em maçã para diferenciar as estirpes hipovirulentas das virulentas de C. parasitica. Os isolados virulentos evidenciaram sempre uma maior atividade de lacase induzida por ácido tânico (Lac3) e de outras enzimas lenhinolíticas (LiP, MnP e celulase) quando comparadas com os hipovirulentos. Os resultados da análise dos perfis metabólicos mostram que alguns grupos de substratos foram mais consumidos por isolados hipovirulentos. Estes estudos abrem novas perspetivas para entender o processo biológico usado pelo hipovírus, e sugerem que este é um método para discriminar estirpes hipovirulentas, e estudar a ecologia e a aptidão em campo destes isolados do fungo.