Identificação de genes expressos na interação compatível Hemileia vastatrix - cafeeiro por meio de sequenciamento de cDNAs.

• Autor(a) principal: Rocha, Cynthia de Melo
• Data de Publicação: 2010
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1028
• topic: Café; Hermileia vastatrix; Genética molecular; Cofee; Hemileia vastatrix; Molecular Genetics; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOSSANIDADE::FITOPATOLOGIA

Changes in the expression pattern of genes in the pathogen and host plant factors are determinates of the phenotype of plant-pathogen interaction. Thus, the objective was to identify and characterize genes and coffee Hemileia vastatrix expressed in a compatible interaction through the sequencing of clones from a cDNA library of infected tissue. The cDNA library was constructed from mRNA isolated from coffee leaves infected with H. vastatrix to 25 days after inoculation. We performed single pass sequencing of 8274 clones from the cDNA library of H. vastatrix and Coffea arabica interaction and 6479 expressed sequence tags (ESTs) were obtained. Among them, 5 091 (78.6%) sequences represent plant genes deposited in GenBank / NCBI and 562 (8.7%) sequences represent genes of fungi and 826 (12.7%) represent genes not yet characterized characterized (e- value ≤ 10-5). The alignment achieved with the 5091 sequences that showed similarity to plant genes resulted in 1891 unique sequences, comprised of 887 contiguous and 1004 singlets. Most of these sequences represent genes with unknown function. Among the sequences similar to genes that encode proteins with known functions, there was a larger number of genes that encode ribosomal proteins, followed by the group of genes that encode proteins involved in primary metabolism and energy production, and 27 sequences showed similarity to genes that encode proteins related to defense process such as WRKY transcription factors, protein kinases, phosphatases, metallothionein, PRs, chitinases, beta-1 ,3-glucanase, enzymes such as phenylalanine ammonia-lyase, glutathione S-transferase. Of the 562 sequences that showed similarity to genes of fungi, 254 were unique sequences, represented by 79 and 175 contiguous singlets. Most sequences represented genes encoding proteins of known function. The biggest group of genes with known function encodes ribosomal protein, followed by the group of genes that encode proteins involved in primary metabolism and energy production, while 13 sequences showed similarity to genes related to the process of infection such as PIG1, and PIG4 PIG8 (plant-induced genes), RTP1 (Rust Transferred Protein 1), protein kinases and MRP (Multidrug resistance-associated protein 1 transporter). Elsewhere it is noted that ESTs representing genes not characterized and not deposited totaled 52% of the total. These genes may include plant genes and genes of the fungus, in this case possible effectors have not yet characterized. Construction of cDNA library from infected tissues of H. vastatrix - coffee interaction was effective for identifying potential genes of the plant and the pathogen expressed in this interaction, but functional studies should be conducted to confirm and quantify the role of each of these genes in interaction.