Identificação e caracterização de genes que codificam proteínas secretadas por Hemileia vastatrix na interação com o cafeeiro

• Autor(a) principal: Fernandes, Michelle Bayerl
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4390
• topic: Ferrugem do cafeeiro; Hemileia vastatrix; Efetores; Coffee rust; Hemileia vastatrix; Effectors; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOSSANIDADE::FITOPATOLOGIA

The coffee leaf rust caused by the biotrophic fungus Hemileia vastatrix, it is the most important fungal disease of coffee, causing productivity losses and its control increases the costs of coffee production. This study aimed to identify genes of H. vastatrix that encode secreted proteins that may function as effectors needed for the establishment of the biotrophic interaction and / or as triggers of resistance responses, by analyzing a database consisting of 9828 expressed sequence tags (ESTs) from an susceptible interaction. These ESTs were generated by sequencing the 5' end of cDNA clones from a library constructed from mRNA isolated from coffee leaves collected 12 days after inoculation with single pustule isolation HV-01. It was obtained 1004 contigs and 3301 singlets after clustering the sequences using the CAP3 program. From 890 unique transcripts that encode proteins without similarity to sequences of non-redundant database of GenBank / NCBI, which had no identity to sequences of Coffea spp., also deposited in this database, were identified 46 ORFs that encode peptides over 60 amino acids with positive prediction from five or more parameters of algorithms used to predict secretion signal sequences. We selected five genes which were amplified from the H. vastatrix genome, generating fragments equal or higher than those amplified from cDNAs. These genes, unique to H. vastatrix showed no identity with cDNA sequences derived from germination spores, demonstrating that their expression may occur within the infected tissue. The secretion of proteins encoded by four genes was demonstrated using the Yeast Secretion System. Functional studies should be conducted to confirm the effector activity of the genes characterized, as well as from other genes identified in this study, whose origin and secretion of fungal the predicted proteins in yeast has been demonstrated.