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Hennen, Joe Fleetwood - One of the best experts on this subject based on the ideXlab platform.
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Uredinales on Blechnaceae, Thelypteridaceae, Schizaeaceae, Myrtaceae, Oxalidaceae, Rhamnaceae, Rubiaceae, Sapindaceae, Smilacaceae e Vitaceae of the Forest Reserve Armando de Salles Oliveira, São Paulo, SP, Brazil
Instituto de Botânica, 2007Co-Authors: Anibal Alves De ,carvalho Júnior, Figueiredo, Mário Barreto, Furtado, Edson Luiz [unesp], Hennen, Joe FleetwoodAbstract:O objetivo do presente trabalho é apresentar as espécies de Uredinales sobre membros de Blechnaceae, Thelypteridaceae, Schizaeaceae, Myrtaceae, Oxalidaceae, Rhamnaceae, Rubiaceae, Sapindaceae, Smilacaceae e Vitaceae da Reserva Florestal da Cidade Universitária Armando de Salles Oliveira São Paulo, SP, Brasil. As espécies descritas e ilustradas bem como seus respectivos hospedeiros são: Desmella anemiae Syd. & P. Syd. sobre Blechnum occidentale L. (Blechnaceae) e Thelypteris dentata (Forssk.) E. St. John (Thelypteridaceae), Endophyllum circumscriptum (Schwein.) Whetzel & Olive sobre Cissus selloana Planch. (Vitaceae), Hemileia vastatrix Berk. & Broome sobre Coffea arabica L. (Rubiaceae), Phakopsora colubrinae Viégas sobre Hovenia dulcis Thunb. (Rhamnaceae), Puccinia arechavaletae Speg. sobre Serjania caracasana (Jacq.) Willd. e Serjania communis Cambess. (Sapindaceae), Puccinia lygodii Arthur sobre Lygodium volubile Sw. (Schizaeaceae), Puccinia oxalidis Dietel & Ellis sobre Oxalis latifolia Kunth (Oxalidaceae), Puccinia psidii G. Winter sobre Psidium guajava L. e Syzygium jambos (L.) Alston (Myrtaceae) e Sphenospora smilacina Syd. sobre Smilax quinquenervia Vell. (Smilacaceae).The aim of this paper is to report the Uredinales collected on members of Blechnaceae, Thelypteridaceae, Schizaeaceae, Myrtaceae, Oxalidaceae, Rhamnaceae, Rubiaceae, Sapindaceae, Smilacaceae and Vitaceae in the Forest Reserve Armando de Salles Oliveira at the campus of São Paulo University, São Paulo, SP, Brazil. The rust fungi collected, described and illustrated, as well as their respectives hosts were: Desmella anemiae Syd. & P. Syd. on Blechnum occidentale L. (Blechnaceae) and Thelypteris dentata (Forssk.) E. St. John (Thelypteridaceae), Endophyllum circumscriptum (Schwein.) Whetzel & Olive on Cissus selloana Planch. (Vitaceae), Hemileia vastatrix Berk. & Broome on Coffea arabica L. (Rubiaceae), Phakopsora colubrinae Viégas on Hovenia dulcis Thunb. (Rhamnaceae), Puccinia arechavaletae Speg. on Serjania caracasana Willd. and Serjania communis Cambess. (Sapindaceae), Puccinia lygodii Arthur on Lygodium volubile Sw. (Schizaeaceae), Puccinia oxalidis Dietel & Ellis on Oxalis latifolia Kunth (Oxalidaceae), Puccinia psidii G. Winter on Psidium guajava L. and Syzygium jambos (L.) Alston (Myrtaceae) and Sphenospora smilacina Syd. on Smilax quinquenervia Vell. (Smilacaceae)
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Uredinales sobre Blechnaceae, Thelypteridaceae, Schizaeaceae, Myrtaceae, Oxalidaceae, Rhamnaceae, Rubiaceae, Sapindaceae, Smilacaceae e Vitaceae da Reserva Florestal Armando de Salles Oliveira, São Paulo, SP, Brasil
Instituto de Botânica, 2007Co-Authors: Anibal Alves De ,carvalho Júnior, Figueiredo, Mário Barreto, Furtado, Edson Luiz, Hennen, Joe FleetwoodAbstract:O objetivo do presente trabalho é apresentar as espécies de Uredinales sobre membros de Blechnaceae, Thelypteridaceae, Schizaeaceae, Myrtaceae, Oxalidaceae, Rhamnaceae, Rubiaceae, Sapindaceae, Smilacaceae e Vitaceae da Reserva Florestal da Cidade Universitária Armando de Salles Oliveira São Paulo, SP, Brasil. As espécies descritas e ilustradas bem como seus respectivos hospedeiros são: Desmella anemiae Syd. & P. Syd. sobre Blechnum occidentale L. (Blechnaceae) e Thelypteris dentata (Forssk.) E. St. John (Thelypteridaceae), Endophyllum circumscriptum (Schwein.) Whetzel & Olive sobre Cissus selloana Planch. (Vitaceae), Hemileia vastatrix Berk. & Broome sobre Coffea arabica L. (Rubiaceae), Phakopsora colubrinae Viégas sobre Hovenia dulcis Thunb. (Rhamnaceae), Puccinia arechavaletae Speg. sobre Serjania caracasana (Jacq.) Willd. e Serjania communis Cambess. (Sapindaceae), Puccinia lygodii Arthur sobre Lygodium volubile Sw. (Schizaeaceae), Puccinia oxalidis Dietel & Ellis sobre Oxalis latifolia Kunth (Oxalidaceae), Puccinia psidii G. Winter sobre Psidium guajava L. e Syzygium jambos (L.) Alston (Myrtaceae) e Sphenospora smilacina Syd. sobre Smilax quinquenervia Vell. (Smilacaceae).The aim of this paper is to report the Uredinales collected on members of Blechnaceae, Thelypteridaceae, Schizaeaceae, Myrtaceae, Oxalidaceae, Rhamnaceae, Rubiaceae, Sapindaceae, Smilacaceae and Vitaceae in the Forest Reserve Armando de Salles Oliveira at the campus of São Paulo University, São Paulo, SP, Brazil. The rust fungi collected, described and illustrated, as well as their respectives hosts were: Desmella anemiae Syd. & P. Syd. on Blechnum occidentale L. (Blechnaceae) and Thelypteris dentata (Forssk.) E. St. John (Thelypteridaceae), Endophyllum circumscriptum (Schwein.) Whetzel & Olive on Cissus selloana Planch. (Vitaceae), Hemileia vastatrix Berk. & Broome on Coffea arabica L. (Rubiaceae), Phakopsora colubrinae Viégas on Hovenia dulcis Thunb. (Rhamnaceae), Puccinia arechavaletae Speg. on Serjania caracasana Willd. and Serjania communis Cambess. (Sapindaceae), Puccinia lygodii Arthur on Lygodium volubile Sw. (Schizaeaceae), Puccinia oxalidis Dietel & Ellis on Oxalis latifolia Kunth (Oxalidaceae), Puccinia psidii G. Winter on Psidium guajava L. and Syzygium jambos (L.) Alston (Myrtaceae) and Sphenospora smilacina Syd. on Smilax quinquenervia Vell. (Smilacaceae).Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Maria Do Céu Silva - One of the best experts on this subject based on the ideXlab platform.
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A method for obtaining RNA from Hemileia vastatrix appressoria produced in planta, suitable for transcriptomic analyses.
Fungal Biology, 2015Co-Authors: Andreia Loureiro, Helena Gil Azinheira, Maria Do Céu Silva, Pedro TalhinhasAbstract:Appressoria are the first infection structures developed by rust fungi and require specific topographic signals from the host for their differentiation. The ease in obtaining appressoria in vitro for these biotrophic fungi led to studies concerning gene expression and gene discovery at appressorial level, avoiding the need to distinguish plant and fungal transcripts. However, in some pathosystems, it was observed that gene expression in appressoria seems to be influenced by host-derived signals, suggesting that transcriptomic analyses performed from in planta differentiated appressoria would be potentially more informative than those from in vitro differentiated appressoria. Nevertheless analysing appressorial RNA obtained from in planta samples is often hampered by an excessive dilution of fungal RNA within plant RNA, besides uncertainty regarding the fungal or plant origin of RNA from highly conserved genes. To circumvent these difficulties, we have recovered Hemileia vastatrix appressoria from Arabica coffee leaf surface using a film of nitrocellulose dissolved in butyl and ethyl acetates (nail polish), and extracted fungal RNA from the polish peel. RNA thus obtained is of good quality and usable for cDNA synthesis and transcriptomic (quantitative PCR) studies. This method could provide the means to investigate specific host-induced appressoria-related fungal pathogenicity factors.
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Phylogenetic analysis of Hemileia vastatrix and related taxa using a genome-scale approach
2012Co-Authors: Diogo N. Silva, Pedro Talhinhas, Ana Vieira, Helena Gil Azinheira, Maria Do Céu Silva, Diana Fernandez, Octávio S Paulo, Sébastien Duplessis, Dora BatistaAbstract:For more than a century, Coffee Leaf Rust caused by the biotrophic fungus Hemileia vastatrix, has increasingly stood out as one of the major factors hampering Arabica coffee production. Since its first historical outburst in the 19th century in Sri Lanka, this disease has rapidly spread worldwide and currently occurs in nearly all the regions of the world where coffee is grown. Despite its widespread distribution and negative economic impact, little is known about its evolutionary origin and phylogenetic placement in the fungal tree of life. Attaining this knowledge, however, would provide fundamental insights on the evolutionary context in which H. vastatrix emerged, which in turn could have important implications to understand the evolution of pathogenicity in this pathogen and in other rusts as well. With this in mind, we are undertaking a genomescale approach that will allow H. vastatrix and other rust fungi to be placed in the fungal tree of life with unprecedented detail by using complete proteomes of five Pucciniomycotina species, approximately 250 000 publicly available EST sequences from several Pucciniomycotina species and H. vastatrix’s recently obtained transcriptome. A high quality matrix that includes orthologs, co-orthologs and recent paralogs is currently being prepared with a sophisticated orthology detection strategy. On a first approach, we have been able to indentify at least 1040 single-copy orthologs that will be used for the phylogenetic analyses. Providing robust and resolved phylogenetic relationships will lay the ground for the identification of genes or gene families that are exclusive to H. vastatrix as well as genes of rapid evolution and/or subject of positive selection, which would be prime targets for functional studies aiming at disease control and prevention. This information will ultimately contribute significantly to advance our knowledge on H. vastatrix’s pathogenicity.
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Expression profiling of genes involved in the biotrophic colonisation of [i]Coffea arabica[/i] leaves by [i]Hemileia vastatrix[/i]
European Journal of Plant Pathology, 2012Co-Authors: Ana Vieira, Pedro Talhinhas, Andreia Loureiro, Maria Do Céu Silva, Diana Fernandez, Octávio S Paulo, Sébastien Duplessis, Johannes Thürich, Helena Gil AzinheiraAbstract:Coffee Leaf Rust, caused by Hemileia vastatrix, is the most important disease of Arabica coffee (Coffea arabica), which prompts studies aimed at understanding the genetic basis of this pathogen as well as its complex interaction with the host. In this work, 11 genes, putatively involved in signalling, establishment and maintenance of biotrophy (transport and metabolism), were characterised, and their expression profiles during host infection were assessed by RT-qPCR in three compatible coffee-rust interactions comprising two different rust races. The profiles of two chitin deacetylases (CD) and a heterotrimeric G-protein alpha subunit transcripts suggest that these enzymes are involved in host-pathogen recognition and establishment of biotrophy at early stages of infection, and the late expression of the CD1 gene was also recorded. Different expression profiles were observed for a MAP kinase gene between the two rust races, suggesting that this gene may be involved in the differentiation of infection structures in a race-specific pattern. Two amino acid transporters, an invertase, a hexose transporter and a mannitol dehydrogenase presented expression profiles similar to those reported in other rust fungi, indicating a fairly conserved genetic programme related to host infection in rust fungi. The strong upregulation of a Uromyces fabae rust transferred protein 1 orthologous gene was observed in H. vastatrix in planta structures, suggesting that this gene may also play a role during the establishment and the maintenance of biotrophy in coffee leaves. Overall, our results provide valuable insights to the current understanding of the biotrophic interaction between H. vastatrix - C. arabica at the molecular level and will contribute to a reasoned and sustainable use of resistant genotypes.
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454 pyrosequencing of coffea arabica leaves infected by the rust fungus Hemileia vastatrix reveals in planta expressed pathogen secreted proteins and plant functions in a late compatible plant rust interaction
Molecular Plant Pathology, 2012Co-Authors: Diana Fernandez, Anne-sophie Petitot, Emilie Tisserant, Julie Poulain, Corinne Da Silva, Pedro Talhinhas, Ana Vieira, Andreia Loureiro, Helena Gil Azinheira, Maria Do Céu SilvaAbstract:Coffee (Coffea arabica L.), one of the key export and cash crops in tropical and subtropical countries, suffers severe losses from the rust fungus Hemileia vastatrix. The transcriptome of H. vastatrix was analysed during a compatible interaction with coffee to obtain an exhaustive repertoire of the genes expressed during infection and to identify potential effector genes. Large-scale sequencing (454-GS-FLEX Titanium) of mixed coffee and rust cDNAs obtained from 21-day rust-infected leaves generated 352 146 sequences which assembled into 22 774 contigs. In the absence of any reference genomic sequences for Coffea or Hemileia, specific trinucleotide frequencies within expressed sequence tags (ESTs) and blast homology against a set of dicots and basidiomycete genomes were used to distinguish pathogen from plant sequences. About 30% (6763) of the contigs were assigned to H. vastatrix and 61% (13 951) to C. arabica. The majority (60%) of the rust sequences did not show homology to any genomic database, indicating that they were potential novel fungal genes. In silico analyses of the 6763 H. vastatrix contigs predicted 382 secreted proteins and identified homologues of the flax rust haustorially expressed secreted proteins (HESPs) and bean rust transferred protein 1 (RTP1). These rust candidate effectors showed conserved amino-acid domains and conserved patterns of cysteine positions suggestive of conserved functions during infection of host plants. Quantitative reverse transcription-polymerase chain reaction profiling of selected rust genes revealed dynamic expression patterns during the time course of infection of coffee leaves. This study provides the first valuable genomic resource for the agriculturally important plant pathogen H. vastatrix and the first comprehensive C. arabica EST dataset.
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coffee coffea arabica l genes early expressed during infection by the rust fungus Hemileia vastatrix
Molecular Plant Pathology, 2004Co-Authors: Diana Fernandez, Anne-sophie Petitot, Leonor Guerraguimaraes, Maria Do Céu Silva, Patricia Santos, Caroline Agostini, Marieclaude Bon, A Ribeiro, Xavier Argout, Michel NicoleAbstract:SUMMARY The beverage cash crop coffee (Coffea arabica L.) is subject to severe losses caused by the rust fungus Hemileia vastatrix. In naturally resistant coffee plants, a specific hypersensitive reaction (HR) may be elicited early to stop fungal infection. To isolate host genes involved in HR, we undertook an expressed sequence tags (ESTs) analysis. Two cDNA libraries were constructed using suppression subtractive hybridization (SSH) and 527 non-redundant ESTs were generated from 784 randomly picked clones. Classification of the ESTs into several functional categories showed that more than one-quarter of the predicted proteins might encode disease resistance (R) proteins, stress- and defence-proteins, and components of signal transduction pathways. Twenty-eight differentially screened sequences (DSSs) were selected after differential hybridization of 1000 cDNA clones from each library. Investigation of the expression patterns of a subset of 13 DSSs showed higher levels of gene expression in inoculated plants compared with control plants. HR-up-regulation of transcript accumulation occurred for 9 out of the 13 genes 24 and 48 h after H. vastatrix challenge. Two genes encoded homologues of the Arabidopsis DND1 and NDR1 proteins, suggesting conservation of resistance signalling pathways in perennial plants. Other HR-regulated sequences matched receptor kinases, AP2 domain- and WRKY transcription factors, cytochromes P450, heat shock 70 proteins, glucosyltransferases and proteins of unknown function. The ESTs reported here provide a useful resource for studying coffee resistance responses and for improving C. arabica for durable disease resistance.
Leonor Guerraguimaraes - One of the best experts on this subject based on the ideXlab platform.
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the coffee leaf rust pathogen Hemileia vastatrix one and a half centuries around the tropics
Molecular Plant Pathology, 2017Co-Authors: Pedro Talhinhas, Diogo N. Silva, Dora Batista, Ines Diniz, Ana Vieira, Andreia Loureiro, Silvia Tavares, A P Pereira, Helena Gil Azinheira, Leonor GuerraguimaraesAbstract:SummaryTaxonomy and History Hemileia vastatrix Berk. and Broome (Basidiomycota, Pucciniales) was described in 1869 in eastern Africa and Ceylon as the agent of coffee leaf rust and has spread to all coffee cultivation areas worldwide. Major disease outbreaks in Asia, Africa and America caused and continue to cause severe yield losses, making this the most important disease of Arabica coffee, a cash crop for many tropical and sub-tropical countries. Life cycle and Disease symptoms Hemileia vastatrix is a hemicyclic fungus with the urediniosporic life cycle as its most important (if not only) source of inoculum. Chlorotic spots are the first macroscopic symptoms, preceding the differentiation of suprastomatal, bouquet-shaped, orange-coloured uredinia. The disease can cause yield losses of up to 35% and have a polyetic epidemiological impact on subsequent years. Disease control Although the use of fungicides is one of the preferred immediate control measures, the use of resistant cultivars is considered to be the most effective and durable disease control strategy. The discovery of ‘Hibrido de Timor’ provided sources of resistance that have been used in several breeding programmes and that have been proven to be effective and durable, as some have been in use for more than 30 years. Genetic diversity and Molecular pathogenicity Although exhibiting limited genetic polymorphism, the very large genome of H. vastatrix (c. 797 Mbp) conceals great pathological diversity, with more than 50 physiological races. Gene expression studies have revealed a very precocious activation of signalling pathways and production of putative effectors, suggesting that the plant–fungus dialogue starts as early as at the germ tube stage, and have provided clues for the identification of avr genes.
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coffee coffea arabica l genes early expressed during infection by the rust fungus Hemileia vastatrix
Molecular Plant Pathology, 2004Co-Authors: Diana Fernandez, Anne-sophie Petitot, Leonor Guerraguimaraes, Maria Do Céu Silva, Patricia Santos, Caroline Agostini, Marieclaude Bon, A Ribeiro, Xavier Argout, Michel NicoleAbstract:SUMMARY The beverage cash crop coffee (Coffea arabica L.) is subject to severe losses caused by the rust fungus Hemileia vastatrix. In naturally resistant coffee plants, a specific hypersensitive reaction (HR) may be elicited early to stop fungal infection. To isolate host genes involved in HR, we undertook an expressed sequence tags (ESTs) analysis. Two cDNA libraries were constructed using suppression subtractive hybridization (SSH) and 527 non-redundant ESTs were generated from 784 randomly picked clones. Classification of the ESTs into several functional categories showed that more than one-quarter of the predicted proteins might encode disease resistance (R) proteins, stress- and defence-proteins, and components of signal transduction pathways. Twenty-eight differentially screened sequences (DSSs) were selected after differential hybridization of 1000 cDNA clones from each library. Investigation of the expression patterns of a subset of 13 DSSs showed higher levels of gene expression in inoculated plants compared with control plants. HR-up-regulation of transcript accumulation occurred for 9 out of the 13 genes 24 and 48 h after H. vastatrix challenge. Two genes encoded homologues of the Arabidopsis DND1 and NDR1 proteins, suggesting conservation of resistance signalling pathways in perennial plants. Other HR-regulated sequences matched receptor kinases, AP2 domain- and WRKY transcription factors, cytochromes P450, heat shock 70 proteins, glucosyltransferases and proteins of unknown function. The ESTs reported here provide a useful resource for studying coffee resistance responses and for improving C. arabica for durable disease resistance.
Pedro Talhinhas - One of the best experts on this subject based on the ideXlab platform.
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the coffee leaf rust pathogen Hemileia vastatrix one and a half centuries around the tropics
Molecular Plant Pathology, 2017Co-Authors: Pedro Talhinhas, Diogo N. Silva, Dora Batista, Ines Diniz, Ana Vieira, Andreia Loureiro, Silvia Tavares, A P Pereira, Helena Gil Azinheira, Leonor GuerraguimaraesAbstract:SummaryTaxonomy and History Hemileia vastatrix Berk. and Broome (Basidiomycota, Pucciniales) was described in 1869 in eastern Africa and Ceylon as the agent of coffee leaf rust and has spread to all coffee cultivation areas worldwide. Major disease outbreaks in Asia, Africa and America caused and continue to cause severe yield losses, making this the most important disease of Arabica coffee, a cash crop for many tropical and sub-tropical countries. Life cycle and Disease symptoms Hemileia vastatrix is a hemicyclic fungus with the urediniosporic life cycle as its most important (if not only) source of inoculum. Chlorotic spots are the first macroscopic symptoms, preceding the differentiation of suprastomatal, bouquet-shaped, orange-coloured uredinia. The disease can cause yield losses of up to 35% and have a polyetic epidemiological impact on subsequent years. Disease control Although the use of fungicides is one of the preferred immediate control measures, the use of resistant cultivars is considered to be the most effective and durable disease control strategy. The discovery of ‘Hibrido de Timor’ provided sources of resistance that have been used in several breeding programmes and that have been proven to be effective and durable, as some have been in use for more than 30 years. Genetic diversity and Molecular pathogenicity Although exhibiting limited genetic polymorphism, the very large genome of H. vastatrix (c. 797 Mbp) conceals great pathological diversity, with more than 50 physiological races. Gene expression studies have revealed a very precocious activation of signalling pathways and production of putative effectors, suggesting that the plant–fungus dialogue starts as early as at the germ tube stage, and have provided clues for the identification of avr genes.
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A method for obtaining RNA from Hemileia vastatrix appressoria produced in planta, suitable for transcriptomic analyses.
Fungal Biology, 2015Co-Authors: Andreia Loureiro, Helena Gil Azinheira, Maria Do Céu Silva, Pedro TalhinhasAbstract:Appressoria are the first infection structures developed by rust fungi and require specific topographic signals from the host for their differentiation. The ease in obtaining appressoria in vitro for these biotrophic fungi led to studies concerning gene expression and gene discovery at appressorial level, avoiding the need to distinguish plant and fungal transcripts. However, in some pathosystems, it was observed that gene expression in appressoria seems to be influenced by host-derived signals, suggesting that transcriptomic analyses performed from in planta differentiated appressoria would be potentially more informative than those from in vitro differentiated appressoria. Nevertheless analysing appressorial RNA obtained from in planta samples is often hampered by an excessive dilution of fungal RNA within plant RNA, besides uncertainty regarding the fungal or plant origin of RNA from highly conserved genes. To circumvent these difficulties, we have recovered Hemileia vastatrix appressoria from Arabica coffee leaf surface using a film of nitrocellulose dissolved in butyl and ethyl acetates (nail polish), and extracted fungal RNA from the polish peel. RNA thus obtained is of good quality and usable for cDNA synthesis and transcriptomic (quantitative PCR) studies. This method could provide the means to investigate specific host-induced appressoria-related fungal pathogenicity factors.
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Phylogenetic analysis of Hemileia vastatrix and related taxa using a genome-scale approach
2012Co-Authors: Diogo N. Silva, Pedro Talhinhas, Ana Vieira, Helena Gil Azinheira, Maria Do Céu Silva, Diana Fernandez, Octávio S Paulo, Sébastien Duplessis, Dora BatistaAbstract:For more than a century, Coffee Leaf Rust caused by the biotrophic fungus Hemileia vastatrix, has increasingly stood out as one of the major factors hampering Arabica coffee production. Since its first historical outburst in the 19th century in Sri Lanka, this disease has rapidly spread worldwide and currently occurs in nearly all the regions of the world where coffee is grown. Despite its widespread distribution and negative economic impact, little is known about its evolutionary origin and phylogenetic placement in the fungal tree of life. Attaining this knowledge, however, would provide fundamental insights on the evolutionary context in which H. vastatrix emerged, which in turn could have important implications to understand the evolution of pathogenicity in this pathogen and in other rusts as well. With this in mind, we are undertaking a genomescale approach that will allow H. vastatrix and other rust fungi to be placed in the fungal tree of life with unprecedented detail by using complete proteomes of five Pucciniomycotina species, approximately 250 000 publicly available EST sequences from several Pucciniomycotina species and H. vastatrix’s recently obtained transcriptome. A high quality matrix that includes orthologs, co-orthologs and recent paralogs is currently being prepared with a sophisticated orthology detection strategy. On a first approach, we have been able to indentify at least 1040 single-copy orthologs that will be used for the phylogenetic analyses. Providing robust and resolved phylogenetic relationships will lay the ground for the identification of genes or gene families that are exclusive to H. vastatrix as well as genes of rapid evolution and/or subject of positive selection, which would be prime targets for functional studies aiming at disease control and prevention. This information will ultimately contribute significantly to advance our knowledge on H. vastatrix’s pathogenicity.
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Cellular and molecular analyses of coffee resistance to Hemileia vastatrix and nonhost resistance to Uromyces vignae in the resistance-donor genotype HDT832/2
European Journal of Plant Pathology, 2012Co-Authors: Ines Diniz, Anne-sophie Petitot, Pedro Talhinhas, Helena Gil Azinheira, Diana Fernandez, Michel Nicole, Vítor Várzea, Clara Medeira, Isabel Maia, Maria Do Céu SilvaAbstract:In Arabica coffee breeding, some of the most used sources of resistance to leaf rust ( Hemileia vastatrix ) are natural Coffea arabica x canephora hybrids (“Híbrido de Timor”). To decipher the cellular and molecular nature of that resistance, leaves of genotype HDT832/2, were challenged with H. vastatrix race II, and monitored using light microscopy and RT-qPCR expression analysis of genes involved in plant immunity mechanisms ( receptor-like kinase , WRKY transcription factor 1 , phenylalanine ammonia-lyase , chalcone synthase , 13-lipoxygenase , glycosyltransferase , pathogenesis related PR1b and PR10 ). These were compared to the nonhost resistance responses of HDT832/2 to the infection by the cowpea rust fungus ( Uromyces vignae ). H. vastatrix ceased growth more frequently after stomata penetration, forming few haustoria, inducing a hypersensitive-like response, phenol accumulation and haustorium encasement with callose. U. vignae could enter stomata but failed to form haustoria, while inducing hypersensitive-like responses and phenol accumulation. In host and nonhost interactions, activation of genes involved in signalling coincided with the differentiation of appressoria, and cellular responses (hypersensitive-like responses and accumulation of phenolic compounds) were recorded from the full appressorium or penetration hypha stages onwards. Similarly, a gene related to the JA pathway was first activated at the penetration hypha stage for both interactions, while genes related to the SA pathway were only activated in the host interaction, the latter being the single clear difference between host and nonhost interactions. The cellular and molecular resistance responses of HDT832/2 to these rust fungi suggest that common immunity components are shared between host and nonhost resistance, which may explain the longer durability of this resistance.
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Expression profiling of genes involved in the biotrophic colonisation of [i]Coffea arabica[/i] leaves by [i]Hemileia vastatrix[/i]
European Journal of Plant Pathology, 2012Co-Authors: Ana Vieira, Pedro Talhinhas, Andreia Loureiro, Maria Do Céu Silva, Diana Fernandez, Octávio S Paulo, Sébastien Duplessis, Johannes Thürich, Helena Gil AzinheiraAbstract:Coffee Leaf Rust, caused by Hemileia vastatrix, is the most important disease of Arabica coffee (Coffea arabica), which prompts studies aimed at understanding the genetic basis of this pathogen as well as its complex interaction with the host. In this work, 11 genes, putatively involved in signalling, establishment and maintenance of biotrophy (transport and metabolism), were characterised, and their expression profiles during host infection were assessed by RT-qPCR in three compatible coffee-rust interactions comprising two different rust races. The profiles of two chitin deacetylases (CD) and a heterotrimeric G-protein alpha subunit transcripts suggest that these enzymes are involved in host-pathogen recognition and establishment of biotrophy at early stages of infection, and the late expression of the CD1 gene was also recorded. Different expression profiles were observed for a MAP kinase gene between the two rust races, suggesting that this gene may be involved in the differentiation of infection structures in a race-specific pattern. Two amino acid transporters, an invertase, a hexose transporter and a mannitol dehydrogenase presented expression profiles similar to those reported in other rust fungi, indicating a fairly conserved genetic programme related to host infection in rust fungi. The strong upregulation of a Uromyces fabae rust transferred protein 1 orthologous gene was observed in H. vastatrix in planta structures, suggesting that this gene may also play a role during the establishment and the maintenance of biotrophy in coffee leaves. Overall, our results provide valuable insights to the current understanding of the biotrophic interaction between H. vastatrix - C. arabica at the molecular level and will contribute to a reasoned and sustainable use of resistant genotypes.
Diana Fernandez - One of the best experts on this subject based on the ideXlab platform.
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Identification and characterization of the Non- race specific Disease Resistance 1 (NDR1) orthologous protein in coffee
2020Co-Authors: Jean-luc Cacas, Anne-sophie Petitot, Louis Bernier, Joan Estevan, Geneviève Conejero, Sébastien Mongrand, Diana FernandezAbstract:Abstract Background: Leaf rust, which is caused by the fungus Hemileia vastatrix (Pucciniales), is a devastating disease that affects coffee plants (Coffea arabica L.). Disadvantages that are associated with currently developed phytoprotection approaches have recently led to the search for alternative strategies. These include genetic manipulations that constitutively activate disease resistance signaling pathways. However, molecular actors of such pathways still remain unknown in C. arabica. In this study, we have isolated and characterized the coffee NDR1 gene, whose Arabidopsis ortholog is a well-known master regulator of the hypersensitive response that is dependent on coiledcoil type R-proteins
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Phylogenetic analysis of Hemileia vastatrix and related taxa using a genome-scale approach
2012Co-Authors: Diogo N. Silva, Pedro Talhinhas, Ana Vieira, Helena Gil Azinheira, Maria Do Céu Silva, Diana Fernandez, Octávio S Paulo, Sébastien Duplessis, Dora BatistaAbstract:For more than a century, Coffee Leaf Rust caused by the biotrophic fungus Hemileia vastatrix, has increasingly stood out as one of the major factors hampering Arabica coffee production. Since its first historical outburst in the 19th century in Sri Lanka, this disease has rapidly spread worldwide and currently occurs in nearly all the regions of the world where coffee is grown. Despite its widespread distribution and negative economic impact, little is known about its evolutionary origin and phylogenetic placement in the fungal tree of life. Attaining this knowledge, however, would provide fundamental insights on the evolutionary context in which H. vastatrix emerged, which in turn could have important implications to understand the evolution of pathogenicity in this pathogen and in other rusts as well. With this in mind, we are undertaking a genomescale approach that will allow H. vastatrix and other rust fungi to be placed in the fungal tree of life with unprecedented detail by using complete proteomes of five Pucciniomycotina species, approximately 250 000 publicly available EST sequences from several Pucciniomycotina species and H. vastatrix’s recently obtained transcriptome. A high quality matrix that includes orthologs, co-orthologs and recent paralogs is currently being prepared with a sophisticated orthology detection strategy. On a first approach, we have been able to indentify at least 1040 single-copy orthologs that will be used for the phylogenetic analyses. Providing robust and resolved phylogenetic relationships will lay the ground for the identification of genes or gene families that are exclusive to H. vastatrix as well as genes of rapid evolution and/or subject of positive selection, which would be prime targets for functional studies aiming at disease control and prevention. This information will ultimately contribute significantly to advance our knowledge on H. vastatrix’s pathogenicity.
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Cellular and molecular analyses of coffee resistance to Hemileia vastatrix and nonhost resistance to Uromyces vignae in the resistance-donor genotype HDT832/2
European Journal of Plant Pathology, 2012Co-Authors: Ines Diniz, Anne-sophie Petitot, Pedro Talhinhas, Helena Gil Azinheira, Diana Fernandez, Michel Nicole, Vítor Várzea, Clara Medeira, Isabel Maia, Maria Do Céu SilvaAbstract:In Arabica coffee breeding, some of the most used sources of resistance to leaf rust ( Hemileia vastatrix ) are natural Coffea arabica x canephora hybrids (“Híbrido de Timor”). To decipher the cellular and molecular nature of that resistance, leaves of genotype HDT832/2, were challenged with H. vastatrix race II, and monitored using light microscopy and RT-qPCR expression analysis of genes involved in plant immunity mechanisms ( receptor-like kinase , WRKY transcription factor 1 , phenylalanine ammonia-lyase , chalcone synthase , 13-lipoxygenase , glycosyltransferase , pathogenesis related PR1b and PR10 ). These were compared to the nonhost resistance responses of HDT832/2 to the infection by the cowpea rust fungus ( Uromyces vignae ). H. vastatrix ceased growth more frequently after stomata penetration, forming few haustoria, inducing a hypersensitive-like response, phenol accumulation and haustorium encasement with callose. U. vignae could enter stomata but failed to form haustoria, while inducing hypersensitive-like responses and phenol accumulation. In host and nonhost interactions, activation of genes involved in signalling coincided with the differentiation of appressoria, and cellular responses (hypersensitive-like responses and accumulation of phenolic compounds) were recorded from the full appressorium or penetration hypha stages onwards. Similarly, a gene related to the JA pathway was first activated at the penetration hypha stage for both interactions, while genes related to the SA pathway were only activated in the host interaction, the latter being the single clear difference between host and nonhost interactions. The cellular and molecular resistance responses of HDT832/2 to these rust fungi suggest that common immunity components are shared between host and nonhost resistance, which may explain the longer durability of this resistance.
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Expression profiling of genes involved in the biotrophic colonisation of [i]Coffea arabica[/i] leaves by [i]Hemileia vastatrix[/i]
European Journal of Plant Pathology, 2012Co-Authors: Ana Vieira, Pedro Talhinhas, Andreia Loureiro, Maria Do Céu Silva, Diana Fernandez, Octávio S Paulo, Sébastien Duplessis, Johannes Thürich, Helena Gil AzinheiraAbstract:Coffee Leaf Rust, caused by Hemileia vastatrix, is the most important disease of Arabica coffee (Coffea arabica), which prompts studies aimed at understanding the genetic basis of this pathogen as well as its complex interaction with the host. In this work, 11 genes, putatively involved in signalling, establishment and maintenance of biotrophy (transport and metabolism), were characterised, and their expression profiles during host infection were assessed by RT-qPCR in three compatible coffee-rust interactions comprising two different rust races. The profiles of two chitin deacetylases (CD) and a heterotrimeric G-protein alpha subunit transcripts suggest that these enzymes are involved in host-pathogen recognition and establishment of biotrophy at early stages of infection, and the late expression of the CD1 gene was also recorded. Different expression profiles were observed for a MAP kinase gene between the two rust races, suggesting that this gene may be involved in the differentiation of infection structures in a race-specific pattern. Two amino acid transporters, an invertase, a hexose transporter and a mannitol dehydrogenase presented expression profiles similar to those reported in other rust fungi, indicating a fairly conserved genetic programme related to host infection in rust fungi. The strong upregulation of a Uromyces fabae rust transferred protein 1 orthologous gene was observed in H. vastatrix in planta structures, suggesting that this gene may also play a role during the establishment and the maintenance of biotrophy in coffee leaves. Overall, our results provide valuable insights to the current understanding of the biotrophic interaction between H. vastatrix - C. arabica at the molecular level and will contribute to a reasoned and sustainable use of resistant genotypes.
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454 pyrosequencing of coffea arabica leaves infected by the rust fungus Hemileia vastatrix reveals in planta expressed pathogen secreted proteins and plant functions in a late compatible plant rust interaction
Molecular Plant Pathology, 2012Co-Authors: Diana Fernandez, Anne-sophie Petitot, Emilie Tisserant, Julie Poulain, Corinne Da Silva, Pedro Talhinhas, Ana Vieira, Andreia Loureiro, Helena Gil Azinheira, Maria Do Céu SilvaAbstract:Coffee (Coffea arabica L.), one of the key export and cash crops in tropical and subtropical countries, suffers severe losses from the rust fungus Hemileia vastatrix. The transcriptome of H. vastatrix was analysed during a compatible interaction with coffee to obtain an exhaustive repertoire of the genes expressed during infection and to identify potential effector genes. Large-scale sequencing (454-GS-FLEX Titanium) of mixed coffee and rust cDNAs obtained from 21-day rust-infected leaves generated 352 146 sequences which assembled into 22 774 contigs. In the absence of any reference genomic sequences for Coffea or Hemileia, specific trinucleotide frequencies within expressed sequence tags (ESTs) and blast homology against a set of dicots and basidiomycete genomes were used to distinguish pathogen from plant sequences. About 30% (6763) of the contigs were assigned to H. vastatrix and 61% (13 951) to C. arabica. The majority (60%) of the rust sequences did not show homology to any genomic database, indicating that they were potential novel fungal genes. In silico analyses of the 6763 H. vastatrix contigs predicted 382 secreted proteins and identified homologues of the flax rust haustorially expressed secreted proteins (HESPs) and bean rust transferred protein 1 (RTP1). These rust candidate effectors showed conserved amino-acid domains and conserved patterns of cysteine positions suggestive of conserved functions during infection of host plants. Quantitative reverse transcription-polymerase chain reaction profiling of selected rust genes revealed dynamic expression patterns during the time course of infection of coffee leaves. This study provides the first valuable genomic resource for the agriculturally important plant pathogen H. vastatrix and the first comprehensive C. arabica EST dataset.