Expressão gênica da resposta de defesa de plantas de Eucalyptus grandis à infecção por Puccinia psidii

• Ano de defesa: 2013
• Autor(a) principal: Rosado, Carla Cristina Gonçalves
• Orientador(a): Alfenas, Acelino Couto
• Banca de defesa: Cruz, Cosme Damião , Zerbini, Poliane Alfenas , Alves, Alexandre Alonso
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Ferrugem do eucalipto; Microarranjo; Genes de resistência; Patologia florestal
• Palavras-chave em Inglês: Eucalyptus rust; Microarray; Resistance genes; Forest Pathology
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/1384

In recent years, there has been great expansion in eucalyptus plantations to meet the growing world demand for raw material for forest-based industries. Concurrently, the expansion of planted areas has concomitantly increased the incidence and severity of diseases in plantations. Among these, eucalyptus rust, caused by Puccinia psidii, is one of the most frequent and has the greatest potential losses. The best option for disease control is planting of resistant genotypes, but little is known about the genetic basis of resistance. This work aimed to obtain information about the genetic architecture of the defense response of eucalyptus plants to eucalyptus rust in order to obtain resistant genotypes and minimize the risk of loss to disease. Utilized were rooted cuttings of two clones, G21 and G33, one resistant and the other susceptible to eucalyptus rust, respectively. The identity of the cuttings of each clone was confirmed by microsatellite markers. The experiment was in completely randomized design (CRD) in the Split-Plots layout, containing inoculated and not inoculated cuttings of both clones. The single pustule isolate UFV-2 (race 1) of P.psidii was used. Three apical branches (~6) were collected at 0 h, 6 h, 12 h, 18 h, 24 h, and 48 h after inoculations. For each of the six times eight plants from each genotype were inoculated. Six microarray slides were produced for a total of 48 chambers. In each chamber 46.274 genes were represented. The cRNA was marked with the fluorochromes Cy3 and Cy5. The RNA extracted and the incorporation of the fluorochromes showed themselves to be of good quality. Forty three genes differentially expressed with the ratio G21/G33 of foldchange greater than 1.5 and corrected probability greater than 0.01 were found. Of these, 22 were up-regulated and 21 were down-regulated. Both clones possessed genes directly related to biotic and abiotic stress response, whereas G21 possesses genes called LRR, protein MLO, sulfotransferase 2A, U3 ubiquitin able to intermediate the recognition of the P. psidii infection and efficiently activate the mechanisms that restrict the colonization of the pathogen in the plant material. The results obtained serve to direct future investigations about the pathosystem Eucalyptus-Puccina and aid in the identification of targets for the control of the disease in the field.