Author
Michael Bölker
Other affiliations: University of Colorado Boulder, Ludwig Maximilian University of Munich
Bio: Michael Bölker is an academic researcher from University of Marburg. The author has contributed to research in topics: Ustilago & Cytokinesis. The author has an hindex of 39, co-authored 87 publications receiving 6378 citations. Previous affiliations of Michael Bölker include University of Colorado Boulder & Ludwig Maximilian University of Munich.
Topics: Ustilago, Cytokinesis, Gene, Peroxisome, Fungal protein
Papers published on a yearly basis
Papers
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Max Planck Society1, University of Marburg2, Broad Institute3, Trent University4, University of Toronto5, California State University, Long Beach6, University of British Columbia7, University of Georgia8, University of Louisville9, Utrecht University10, Saint Joseph's University11, Spanish National Research Council12, Cornell University13, CINVESTAV14, University of Kentucky15, Duke University16, University of Valencia17, Saint Louis University18, Bayer19, Exelixis20, Technische Universität München21
TL;DR: The discovery of the secreted protein gene clusters and the functional demonstration of their decisive role in the infection process illuminate previously unknown mechanisms of pathogenicity operating in biotrophic fungi.
Abstract: Ustilago maydis is a ubiquitous pathogen of maize and a well-established model organism for the study of plant-microbe interactions. This basidiomycete fungus does not use aggressive virulence strategies to kill its host. U. maydis belongs to the group of biotrophic parasites (the smuts) that depend on living tissue for proliferation and development. Here we report the genome sequence for a member of this economically important group of biotrophic fungi. The 20.5-million-base U. maydis genome assembly contains 6,902 predicted protein-encoding genes and lacks pathogenicity signatures found in the genomes of aggressive pathogenic fungi, for example a battery of cell-wall-degrading enzymes. However, we detected unexpected genomic features responsible for the pathogenicity of this organism. Specifically, we found 12 clusters of genes encoding small secreted proteins with unknown function. A significant fraction of these genes exists in small gene families. Expression analysis showed that most of the genes contained in these clusters are regulated together and induced in infected tissue. Deletion of individual clusters altered the virulence of U. maydis in five cases, ranging from a complete lack of symptoms to hypervirulence. Despite years of research into the mechanism of pathogenicity in U. maydis, no 'true' virulence factors had been previously identified. Thus, the discovery of the secreted protein gene clusters and the functional demonstration of their decisive role in the infection process illuminate previously unknown mechanisms of pathogenicity operating in biotrophic fungi. Genomic analysis is, similarly, likely to open up new avenues for the discovery of virulence determinants in other pathogens.
1,120 citations
TL;DR: It is demonstrated that the mating type in each allele is determined by a set of two genes, one encodes a precursor for a lipopeptide mating factor, and the other specifies the receptor for the pheromone secreted by cells of opposite mating type.
386 citations
TL;DR: Genetic evidence is provided to show that the pair of bE and bW polypeptides encoded by different b alleles is the key regulatory species.
322 citations
TL;DR: The results suggest a model for self/nonself recognition in which variable cohesive contacts direct dimerization, which is supported with a biochemical interaction assay with immobilized proteins.
253 citations
TL;DR: Haploid strains harbouring gpa3Q206L were able to mate without pheromone stimulation, indicating that Gpa3 plays an active role in transmission of the phersomone signal.
Abstract: In the phytopathogenic fungus Ustilago maydis, cell fusion is governed by a pheromone signalling system. The pheromone receptors belong to the seven transmembrane class that are coupled to heterotrimeric G proteins. We have isolated four genes (gpa1 to gpa4) encoding alpha subunits of G proteins. Gpa1, Gpa2 and Gpa3 have homologues in other fungal species, while Gpa4 is novel. Null mutants in individual genes were viable and only disruption of gpa3 caused a discernible phenotype. gpa3 mutant strains were unable to respond to pheromone and thus were mating-deficient. A constitutively active allele of gpa3 (gpa3(Q206L)) was generated by site-directed mutagenesis. Haploid strains harbouring gpa3(Q206L) were able to mate without pheromone stimulation, indicating that Gpa3 plays an active role in transmission of the pheromone signal. Surprisingly, Gpa3 is also required for pathogenic development, although pheromone signalling is not essential for this process.
248 citations
Cited by
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North Carolina State University1, Wageningen University and Research Centre2, University of the Free State3, Rothamsted Research4, University of Córdoba (Spain)5, Imperial College London6, Texas A&M University7, Max Planck Society8, Commonwealth Scientific and Industrial Research Organisation9, University of Bristol10
TL;DR: A short resumé of each fungus in the Top 10 list and its importance is presented, with the intent of initiating discussion and debate amongst the plant mycology community, as well as laying down a bench-mark.
Abstract: The aim of this review was to survey all fungal pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate which fungal pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 495 votes from the international community, and resulted in the generation of a Top 10 fungal plant pathogen list for Molecular Plant Pathology. The Top 10 list includes, in rank order, (1) Magnaporthe oryzae; (2) Botrytis cinerea; (3) Puccinia spp.; (4) Fusarium graminearum; (5) Fusarium oxysporum; (6) Blumeria graminis; (7) Mycosphaerella graminicola; (8) Colletotrichum spp.; (9) Ustilago maydis; (10) Melampsora lini, with honourable mentions for fungi just missing out on the Top 10, including Phakopsora pachyrhizi and Rhizoctonia solani. This article presents a short resume of each fungus in the Top 10 list and its importance, with the intent of initiating discussion and debate amongst the plant mycology community, as well as laying down a bench-mark. It will be interesting to see in future years how perceptions change and what fungi will comprise any future Top 10.
2,807 citations
TL;DR: The recent convergence of molecular studies of plant immunity and pathogen infection strategies is revealing an integrated picture of the plant–pathogen interaction from the perspective of both organisms, suggesting novel biotechnological approaches to crop protection.
Abstract: Plants are engaged in a continuous co-evolutionary struggle for dominance with their pathogens. The outcomes of these interactions are of particular importance to human activities, as they can have dramatic effects on agricultural systems. The recent convergence of molecular studies of plant immunity and pathogen infection strategies is revealing an integrated picture of the plant-pathogen interaction from the perspective of both organisms. Plants have an amazing capacity to recognize pathogens through strategies involving both conserved and variable pathogen elicitors, and pathogens manipulate the defence response through secretion of virulence effector molecules. These insights suggest novel biotechnological approaches to crop protection.
2,666 citations
TL;DR: Remarkably, fungi, parasites, plants, and animals have distinct subsets of Toolbox motors in their genomes, suggesting an underlying diversity of strategies for intracellular transport.
1,890 citations