Publications
87 results found
Pennington HG, Gheorghe DM, Damerum A, et al., 2016, Interactions between the Powdery Mildew Effector BEC1054 and Barley Proteins Identify Candidate Host Targets, Journal of Proteome Research, Vol: 15, Pages: 826-839, ISSN: 1535-3907
There are over 500 candidate secreted effector proteins (CSEPs) or Blumeria effector candidates (BECs) specific to the barley powdery mildew pathogen Blumeria graminis f.sp. hordei. The CSEP/BEC proteins are expressed and predicted to be secreted by biotrophic feeding structures called haustoria. Eight BECs are required for the formation of functional haustoria. These include the RNase-like effector BEC1054 (synonym CSEP0064). In order to identify host proteins targeted by BEC1054, recombinant BEC1054 was expressed in E. coli, solubilized, and used in pull-down assays from barley protein extracts. Many putative interactors were identified by LC-MS/MS after subtraction of unspecific binders in negative controls. Therefore, a directed yeast-2-hybrid assay, developed to measure the effectiveness of the interactions in yeast, was used to validate putative interactors. We conclude that BEC1054 may target several host proteins, including a glutathione-S-transferase, a malate dehydrogenase, and a pathogen-related-5 protein isoform, indicating a possible role for BEC1054 in compromising well-known key players of defense and response to pathogens. In addition, BEC1054 interacts with an elongation factor 1 gamma. This study already suggests that BEC1054 plays a central role in barley powdery mildew virulence by acting at several levels.
Amselem J, Vigouroux M, Oberhaensli S, et al., 2015, Evolution of the EKA family of powdery mildew avirulence-effector genes from the ORF 1 of a LINE retrotransposon, BMC Genomics, Vol: 16, ISSN: 1471-2164
BackgroundThe Avrk1 and Avra10 avirulence (AVR) genes encode effectors that increase the pathogenicity of the fungus Blumeria graminis f.sp. hordei (Bgh), the powdery mildew pathogen, in susceptible barley plants. In resistant barley, MLK1 and MLA10 resistance proteins recognize the presence of AVRK1 and AVRA10, eliciting the hypersensitive response typical of gene for gene interactions. Avrk1 and Avra10 have more than 1350 homologues in Bgh genome, forming the EKA (Effectors homologous to Avr k 1 and Avr a 10) gene family.ResultsWe tested the hypothesis that the EKA family originated from degenerate copies of Class I LINE retrotransposons by analysing the EKA family in the genome of Bgh isolate DH14 with bioinformatic tools specially developed for the analysis of Transposable Elements (TE) in genomes. The Class I LINE retrotransposon copies homologous to Avrk1 and Avra10 represent 6.5 % of the Bgh annotated genome and, among them, we identified 293 AVR/effector candidate genes. We also experimentally identified peptides that indicated the translation of several predicted proteins from EKA family members, which had higher relative abundance in haustoria than in hyphae.ConclusionsOur analyses indicate that Avrk1 and Avra10 have evolved from part of the ORF1 gene of Class I LINE retrotransposons. The co-option of Avra10 and Avrk1 as effectors from truncated copies of retrotransposons explains the huge number of homologues in Bgh genome that could act as dynamic reservoirs from which new effector genes may evolve. These data provide further evidence for recruitment of retrotransposons in the evolution of new biological functions.
Pennington HG, Li L, Spanu PD, 2015, Identification and selection of normalization controls for quantitative transcript analysis in Blumeria graminis, Molecular Plant Pathology, Vol: 17, Pages: 625-633, ISSN: 1464-6722
The investigation of obligate biotrophic pathogens, for example Blumeria graminis, presents a number of challenges. The sensitivity of many assays is reduced because of the presence of host material. Furthermore, the fungal structures inside and outside of the plant possess very different characteristics. Normalization genes are used in quantitative real-time polymerase chain reaction (qPCR) to compensate for changes as a result of the quantity and quality of template material. Such genes are used as references against which genes of interest are compared, enabling true quantification. Here, we identified six potential B. graminis and five barley genes for qPCR normalization. The relative changes in abundance of the transcripts were assayed across an infection time course in barley epidermis, in B. graminis epiphytic structures and haustoria. The B. graminis glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT) and histone 3 (H3) genes and the barley GAPDH, ubiquitin (UBI) and α-tubulin 2B (TUBA2B) genes were optimal normalization controls for qPCR during the infection cycle. These genes were then used for normalization in the quantification of the members of a Candidate Secreted Effector Protein (CSEP) family 21, a conidia-specific gene and barley genes encoding putative interactors of CSEP0064. The analysis demonstrates the importance of identifying which reference genes are appropriate for each investigation.
Whigham E, Qi S, Mistry D, et al., 2015, Broadly Conserved Fungal Effector BEC1019 Suppresses Host Cell Death and Enhances Pathogen Virulence in Powdery Mildew of Barley (Hordeum vulgare L.), Molecular Plant-Microbe Interactions, Vol: 28, Pages: 968-983, ISSN: 1943-7706
The interaction of barley, Hordeum vulgare L., with the powdery mildew fungus Blumeria graminis f. sp. hordei is a well-developed model to investigate resistance and susceptibility to obligate biotrophic pathogens. The 130-Mb Blumeria genome encodes approximately 540 predicted effectors that are hypothesized to suppress or induce host processes to promote colonization. Blumeria effector candidate (BEC)1019, a single-copy gene encoding a putative, secreted metalloprotease, is expressed in haustorial feeding structures, and host-induced gene silencing of BEC1019 restricts haustorial development in compatible interactions. Here, we show that Barley stripe mosaic virus–induced gene silencing of BEC1019 significantly reduces fungal colonization of barley epidermal cells, demonstrating that BEC1019 plays a central role in virulence. In addition, delivery of BEC1019 to the host cytoplasm via Xanthomonas type III secretion suppresses cultivar nonspecific hypersensitive reaction (HR) induced by Xanthomonas oryzae pv. oryzicola, as well as cultivar-specific HR induced by AvrPphB from Pseudomonas syringae pv. phaseolicola. BEC1019 homologs are present in 96 of 241 sequenced fungal genomes, including plant pathogens, human pathogens, and free-living nonpathogens. Comparative analysis revealed variation at several amino acid positions that correlate with fungal lifestyle and several highly conserved, noncorrelated motifs. Site-directed mutagenesis of one of these, ETVIC, compromises the HR-suppressing activity of BEC1019. We postulate that BEC1019 represents an ancient, broadly important fungal protein family, members of which have evolved to function as effectors in plant and animal hosts.
Spanu PD, 2015, RNA-protein interactions in plant disease: hackers at the dinner table, NEW PHYTOLOGIST, Vol: 207, Pages: 991-995, ISSN: 0028-646X
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- Citations: 14
Kanhayuwa L, Coutts R, Spanu P, 2014, A novel mycovirus in the human pathogenic fungus <i>Aspergillus fumigatus</i> and its application as a virus-induced gene silencing (VIGS) vector, FEBS EMBO 2014 Conference, Publisher: WILEY-BLACKWELL, Pages: 649-649, ISSN: 1742-464X
Panstruga R, Spanu PD, 2014, Powdery mildew genomes reloaded., New Phytol, Vol: 202, Pages: 13-14
Spanu PD, 2014, Messages from Powdery Mildew DNA: How the Interplay with a Host Moulds Pathogen Genomes, JOURNAL OF INTEGRATIVE AGRICULTURE, Vol: 13, Pages: 233-236, ISSN: 2095-3119
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- Citations: 2
Wicker T, Oberhaensli S, Parlange F, et al., 2013, The wheat powdery mildew genome shows the unique evolution of an obligate biotroph, NATURE GENETICS, Vol: 45, Pages: 1092-+, ISSN: 1061-4036
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- Citations: 164
Pliego C, Nowara D, Bonciani G, et al., 2013, Host-Induced Gene Silencing in Barley Powdery Mildew Reveals a Class of Ribonuclease-Like Effectors, MOLECULAR PLANT-MICROBE INTERACTIONS, Vol: 26, Pages: 633-642, ISSN: 0894-0282
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- Citations: 132
Pedersen C, van Themaat E, McGuffin L, et al., 2012, Structure and evolution of barley powdery mildew effector candidates, BMC Genomics, Vol: 13, ISSN: 1471-2164
BACKGROUND:Protein effectors of pathogenicity are instrumental in modulating host immunity and disease resistance. The powdery mildew pathogen of grasses, Blumeria graminis, causes one of the most important diseases of cereal crops. B. graminis is an obligate biotrophic pathogen and as such has an absolute requirement to suppress or avoid host immunity to survive and cause disease.RESULTS:Here we characterise a superfamily predicted to be the full complement of Candidates for Secreted Effector Proteins (CSEPs) in the fungal barley powdery mildew parasite, B. graminis f.sp. hordei. The 491 genes encoding these proteins constitute over 7% of this pathogen’s annotated genes and most were grouped into 72 families of up to 59 members. They were predominantly expressed in the intracellular feeding structures, called haustoria, and proteins specifically associated with haustoria were identified by large-scale mass spectrometry-based proteomics. There are two major types of effector families: one comprises shorter proteins (100–150 amino acids), with a high relative expression level in the haustoria and evidence of extensive diversifying selection between paralogs; the second type consists of longer proteins (300–400 amino acids), with lower levels of differential expression and evidence of purifying selection between paralogs. An analysis of the predicted protein structures reveals polypeptide features that are similar to those of known fungal effectors, but also highlights unexpected structural affinities to ribonucleases throughout the entire effector superfamily. Candidate effector genes belonging to the same family are loosely clustered in the genome and are associated with repetitive DNA derived from retro-transposons.CONCLUSIONS:We employed the full complement of genomic, transcriptomic and proteomic analyses as well as structural prediction methods to identify and characterise the members of the CSEP superfamily in B. graminis f.sp. hordei. Based o
Dean R, Van Kan JAL, Pretorius ZA, et al., 2012, The Top 10 fungal pathogens in molecular plant pathology (vol 13, pg 414, 2012), MOLECULAR PLANT PATHOLOGY, Vol: 13, Pages: 804-804, ISSN: 1464-6722
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- Citations: 40
Spanu PD, Panstruga R, 2012, Powdery mildew genomes in the crosshairs, NEW PHYTOLOGIST, Vol: 195, Pages: 20-22, ISSN: 0028-646X
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- Citations: 11
Dean R, Van Kan JAL, Pretorius ZA, et al., 2012, The Top 10 fungal pathogens in molecular plant pathology, MOLECULAR PLANT PATHOLOGY, Vol: 13, Pages: 414-430, ISSN: 1464-6722
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- Citations: 2413
Spanu PD, 2012, The Genomics of Obligate (and Nonobligate) Biotrophs, ANNUAL REVIEW OF PHYTOPATHOLOGY, VOL 50, Vol: 50, Pages: 91-109, ISSN: 0066-4286
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- Citations: 112
Brewer MT, Cadle-Davidson L, Cortesi P, et al., 2011, Identification and structure of the mating-type locus and development of PCR-based markers for mating type in powdery mildew fungi, FUNGAL GENETICS AND BIOLOGY, Vol: 48, Pages: 704-713, ISSN: 1087-1845
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- Citations: 40
Spanu PD, Abbott JC, Amselem J, et al., 2010, Genome expansion and gene loss in powdery mildew fungi reveal functional tradeoffs in extreme parasitism, Science, Vol: 330, Pages: 1543-1546
Powdery mildews are phytopathogens whose growth and reproduction are entirely dependent on living plant cells. The molecular basis of this life-style, obligate biotrophy, remains unknown. We present the genome analysis of barley powdery mildew, Blumeria graminis f.sp. hordei (Blumeria), as well as a comparison with the analysis of two powdery mildews pathogenic on dicotyledonous plants. These genomes display massive retrotransposon proliferation, genome-size expansion, and gene losses. The missing genes encode enzymes of primary and secondary metabolism, carbohydrate-active enzymes, and transporters, probably reflecting their redundancy in an exclusively biotrophic life-style. Among the 248 candidate effectors of pathogenesis identified in the Blumeria genome, very few (less than 10) define a core set conserved in all three mildews, suggesting that most effectors represent species-specific adaptations.
Oberhaensli S, Parlange F, Buchmann JP, et al., 2010, Comparative sequence analysis of wheat and barley powdery mildew fungi reveals gene colinearity, dates divergence and indicates host pathogen co-evolution, Fugal Genetics and Biology, Vol: 48, Pages: 327-334
The two fungal pathogens Blumeria graminis f. sp. tritici (B.g. tritici) and hordei (B.g. hordei) cause powdery mildew specifically in wheat or barley. They have the same life cycle, but their growth is restricted to the respective host. Here, we compared the sequences of two loci in both cereal mildews to determine their divergence time and their relationship with the evolution of their hosts. We sequenced a total of 273.3 kb derived from B.g. tritici BAC sequences and compared them with the orthologous regions in the B.g. hordei genome. Protein-coding genes were colinear and well conserved. In contrast, the intergenic regions showed very low conservation mostly due to different integration patterns of transposable elements. To estimate the divergence time of B.g. tritici and B.g. hordei, we used conserved intergenic sequences including orthologous transposable elements. This revealed that B.g. tritici and B.g. hordei have diverged about 10 million years ago (MYA), two million years after wheat and barley (12 MYA). These data suggest that B.g. tritici and B.g. hordei have co-evolved with their hosts during most of their evolutionary history after host divergence, possibly after a short phase of host expansion when the same pathogen could still grow on the two diverged hosts.
Ray MJ, Leak DJ, Spanu PD, et al., 2010, Brown rot fungal early stage decay mechanism as a biological pretreatment for softwood biomass in biofuel production, BIOMASS & BIOENERGY, Vol: 34, Pages: 1257-1262, ISSN: 0961-9534
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- Citations: 66
Jayasena AS, Meng Y, Bindschedler L, et al., 2010, <i>Xanthomonas</i> type III secretion system based analysis of candidate effectors from <i>Blumeria graminis</i> f. sp <i>hordei</i>, Annual Meeting of the American-Phytopathological-Society (APS), Publisher: AMER PHYTOPATHOLOGICAL SOC, Pages: S56-S56, ISSN: 0031-949X
Spanu PD, Kämper J, 2010, Genomics of biotrophy in fungi and oomycetes -- emerging patterns, Current Opinion in Plant Biology, Vol: 13, Pages: 409-414
Walton JD, Avis TJ, Alfano JR, et al., 2009, Effectors, Effectors <i>et encore des</i> Effectors: The XIV International Congress on Molecular-Plant Microbe Interactions, Quebec, MOLECULAR PLANT-MICROBE INTERACTIONS, Vol: 22, Pages: 1479-1483, ISSN: 0894-0282
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- Citations: 6
Bindschedler LV, Burgis TA, Mills DJS, et al., 2009, <i>In Planta</i> Proteomics and Proteogenomics of the Biotrophic Barley Fungal Pathogen <i>Blumeria graminis</i> f. sp <i>hordei</i>, MOLECULAR & CELLULAR PROTEOMICS, Vol: 8, Pages: 2368-2381, ISSN: 1535-9476
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- Citations: 65
Lacroix H, Spanu PD, 2009, Silencing of Six Hydrophobins in <i>Cladosporium fulvum</i>: Complexities of Simultaneously Targeting Multiple Genes, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Vol: 75, Pages: 542-546, ISSN: 0099-2240
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- Citations: 13
Lacroix H, Whiteford JR, Spanu PD, 2008, Localization of <i>Cladosporium fulvum</i> hydrophobins reveals a role for HCf-6 in adhesion, FEMS MICROBIOLOGY LETTERS, Vol: 286, Pages: 136-144, ISSN: 0378-1097
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- Citations: 14
Spanu PD, 2008, The genome of <i>Blumeria graminis</i>:: A systems approach to the biology of powdery mildews, 100th Annual Meeting of the American-Phytopathological-Society, Publisher: AMER PHYTOPATHOLOGICAL SOC, Pages: S193-S193, ISSN: 0031-949X
Martino E, Murat C, Vallino M, et al., 2007, Imaging mycorrhizal fungal transformants that express EGFP during ericoid endosymbiosis, CURRENT GENETICS, Vol: 52, Pages: 65-75, ISSN: 0172-8083
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- Citations: 26
Andres-Enguix I, Caley A, Yustos R, et al., 2007, Determinants of the anesthetic sensitivity of two-pore domain acid-sensitive potassium channels: molecular cloning of an anesthetic-activated potassium channelfrom Lymnaea stagnalis, Journal of Biological Chemistry, Vol: 282, Pages: 20977-20990, ISSN: 0021-9258
Bonfante P, Genre A, Spanu PD, 2006, Plant-microbe interactions in Yucatan: hurricanes didn't curb the whirlwind of discovery, NEW PHYTOLOGIST, Vol: 170, Pages: 653-655, ISSN: 0028-646X
Spanu PD, 2006, Why do some fungi give up their freedom and become obligate dependants on their host?, NEW PHYTOLOGIST, Vol: 171, Pages: 447-450, ISSN: 0028-646X
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- Citations: 11
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