title: Overview of the functional virulent genome of the coffee leaf rust pathogen Hemileia vastatrix with an emphasis on early stages of infection.
abstract: Hemileia vastatrix is the causal agent of coffee leaf rust, the most important disease of coffee Arabica. In this work, a 454-pyrosequencing transcriptome analysis of H. vastatrix germinating urediniospores (gU) and appressoria (Ap) was performed and compared to previously published in planta haustoria-rich (H) data. A total of 9234 transcripts were identified and annotated. Ca. 50% of these transcripts showed no significant homology to international databases. Only 784 sequences were shared by the three conditions, and 75% were exclusive of either gU (2146), Ap (1479) or H (3270). Relative transcript abundance and RT-qPCR analyses for a selection of genes indicated a particularly active metabolism, translational activity and production of new structures in the appressoria and intense signaling, transport, secretory activity and cellular multiplication in the germinating urediniospores, suggesting the onset of a plant-fungus dialogue as early as at the germ tube stage. Gene expression related to the production of carbohydrate-active enzymes and accumulation of glycerol in germinating urediniospores and appressoria suggests that combined lytic and physical mechanisms are involved in appressoria-mediated penetration. Besides contributing to the characterization of molecular processes leading to appressoria-mediated infection by rust fungi, these results point toward the identification of new H. vastatrix candidate virulence factors, with 516 genes predicted to encode secreted proteins.
authors.affiliation: Centro de Investigação das Ferrugens do Cafeeiro/BioTrop/Instituto de Investigação Científica Tropical Oeiras, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Talhinhas
authors.affiliation: Centro de Investigação das Ferrugens do Cafeeiro/BioTrop/Instituto de Investigação Científica Tropical Oeiras, Portugal.
authors.forename: Helena G
authors.initials: HG
authors.lastname: Azinheira
authors.affiliation: Computational Biology and Population Genomics Group, Centro de Biologia Ambiental, Faculdade de Ciências da Universidade de Lisboa Lisboa, Portugal.
authors.forename: Bruno
authors.initials: B
authors.lastname: Vieira
authors.affiliation: Centro de Investigação das Ferrugens do Cafeeiro/BioTrop/Instituto de Investigação Científica Tropical Oeiras, Portugal.
authors.forename: Andreia
authors.initials: A
authors.lastname: Loureiro
authors.affiliation: Centro de Investigação das Ferrugens do Cafeeiro/BioTrop/Instituto de Investigação Científica Tropical Oeiras, Portugal.
authors.forename: Sílvia
authors.initials: S
authors.lastname: Tavares
authors.affiliation: Centro de Investigação das Ferrugens do Cafeeiro/BioTrop/Instituto de Investigação Científica Tropical Oeiras, Portugal.
authors.forename: Dora
authors.initials: D
authors.lastname: Batista
authors.affiliation: Institut National de la Recherche Agronomique, Centre INRA Nancy Lorraine, UMR 1136 INRA/Université de Lorraine Interactions Arbres/Micro-organismes Champenoux, France ; Université de Lorraine, UMR 1136 INRA/Université de Lorraine Interactions Arbres/Micro-organismes, Faculté des Sciences et Technologies Vandoeuvre-lès-Nancy, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Morin
authors.affiliation: Institut de Recherche pour le Développement, UMR 186 IRD-Cirad-UM2 Résistance des Plantes aux Bioagresseurs Montpellier, France.
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Petitot
authors.affiliation: Computational Biology and Population Genomics Group, Centro de Biologia Ambiental, Faculdade de Ciências da Universidade de Lisboa Lisboa, Portugal.
authors.forename: Octávio S
authors.initials: OS
authors.lastname: Paulo
authors.affiliation: Genoscope, Centre National de Séquençage, Commissariat à l'Energie Atomique, Institut de Génomique Evry, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Poulain
authors.affiliation: Genoscope, Centre National de Séquençage, Commissariat à l'Energie Atomique, Institut de Génomique Evry, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Da Silva
authors.affiliation: Institut National de la Recherche Agronomique, Centre INRA Nancy Lorraine, UMR 1136 INRA/Université de Lorraine Interactions Arbres/Micro-organismes Champenoux, France ; Université de Lorraine, UMR 1136 INRA/Université de Lorraine Interactions Arbres/Micro-organismes, Faculté des Sciences et Technologies Vandoeuvre-lès-Nancy, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Duplessis
authors.affiliation: Centro de Investigação das Ferrugens do Cafeeiro/BioTrop/Instituto de Investigação Científica Tropical Oeiras, Portugal.
authors.forename: Maria do Céu
authors.initials: Mdo C
authors.lastname: Silva
authors.affiliation: Institut de Recherche pour le Développement, UMR 186 IRD-Cirad-UM2 Résistance des Plantes aux Bioagresseurs Montpellier, France.
authors.forename: Diana
authors.initials: D
authors.lastname: Fernandez
keywords: appressorium; coffee leaf rust; germinating urediniospore; haustorium; pyrosequencing; transcriptome