Identificação e caracterização de genes órfãos ('NO HITS') de café (Coffea spp.).

Coffee is one of the most important agricultural commodities worldwide. Breeding programs aimed at introducing new characters to produce novel varieties with superior agronomic traits, such as, uniform flowering, yield, grain size, beverage quality, lower caffeine content, as well as, disease and drought resistance have been ongoing for several decades. However, with a large number of gene sequences available in Coffea spp. databases, the identification and characterization of novel genes with unknown function (no hits) are feasible and necessary. The aim of this study was to identify and functionally characterize no hits found in coffee databases, using in silico analysis and qPCR gene expression. For in silico analyses, no hits were identified by similarity search in NCBI databases. Coffea arabica and Coffea canephora libraries from different tissues were generated by sequencing data using the Sanger and 454 methods. We performed an electronic Northern search of the no hits in the coffee libraries. Plant material, for qPCR assays, was obtained from different tissues (leaves, roots, fruits and meristems) of the species C. arabica and C. canephora subjected to different biological conditions (biotic and abiotic stresses) and fruits at early, intermediate and late development stages. As a result, in silico analyzes identified and characterized 1.568 orphan genes in accordance with the libraries in which they were expressed. Therefore, we selected and performed qPCR of 17 orphan genes potentially involved in tolerance to biotic and abiotic stresses, as well as, orphan genes involved in coffee fruit development. These genes responded differentially in tissues and with biological conditions, confirming in silico analyzes previously obtained and providing evidences for their probable involvement in specific biological processes in coffee plants.Dissertação (mestrado em Biotecnologia Vegetal) - Universidade Federal de Lavras, Lavras, MG. Orientador: Alan Carvalho de Andrade, Embrapa Recursos Genéticos e Biotecnologia. Coorientador: Pierre Marraccini