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Schuster M, Schweizer G, Reißmann S, Happel P, Aßmann D, Rössel N, Güldener U, Mannhaupt G, Ludwig N, Winterberg S, Pellegrin C, Tanaka S, Vincon V, Presti LL, Wang L, Bender L, Gonzalez C, Vranes M, Kämper J, Seong K, Krasileva K, Kahmann R. Novel Secreted Effectors Conserved Among Smut Fungi Contribute to the Virulence of Ustilago maydis. Mol Plant Microbe Interact 2024; 37:250-263. [PMID: 38416124 DOI: 10.1094/mpmi-09-23-0139-fi] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
Fungal pathogens deploy a set of molecules (proteins, specialized metabolites, and sRNAs), so-called effectors, to aid the infection process. In comparison to other plant pathogens, smut fungi have small genomes and secretomes of 20 Mb and around 500 proteins, respectively. Previous comparative genomic studies have shown that many secreted effector proteins without known domains, i.e., novel, are conserved only in the Ustilaginaceae family. By analyzing the secretomes of 11 species within Ustilaginaceae, we identified 53 core homologous groups commonly present in this lineage. By collecting existing mutants and generating additional ones, we gathered 44 Ustilago maydis strains lacking single core effectors as well as 9 strains containing multiple deletions of core effector gene families. Pathogenicity assays revealed that 20 of these 53 mutant strains were affected in virulence. Among the 33 mutants that had no obvious phenotypic changes, 13 carried additional, sequence-divergent, structurally similar paralogs. We report a virulence contribution of seven previously uncharacterized single core effectors and of one effector family. Our results help to prioritize effectors for understanding U. maydis virulence and provide genetic resources for further characterization. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Mariana Schuster
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
- Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120 Halle, Germany
| | - Gabriel Schweizer
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
- Independent Data Lab UG, 80937 Munich, Germany
| | - Stefanie Reißmann
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Petra Happel
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Daniela Aßmann
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Nicole Rössel
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Ulrich Güldener
- Deutsches Herzzentrum München, Technische Universität München, 80636 München, Germany
| | - Gertrud Mannhaupt
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Nicole Ludwig
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
- Research & Development, Weed Control Bayer AG, Crop Science Division, 65926 Frankfurt am Main, Germany
| | - Sarah Winterberg
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Clément Pellegrin
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Shigeyuki Tanaka
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Volker Vincon
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Libera Lo Presti
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Lei Wang
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Lena Bender
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
- Department of Pharmaceutics and Biopharmaceutics, Phillips-University Marburg, 35037 Marburg, Germany
| | - Carla Gonzalez
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Miroslav Vranes
- Karlsruhe Institute of Technology, Institute for Applied Biosciences, Department of Genetics, 76131 Karlsruhe, Germany
| | - Jörg Kämper
- Karlsruhe Institute of Technology, Institute for Applied Biosciences, Department of Genetics, 76131 Karlsruhe, Germany
| | - Kyungyong Seong
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, U.S.A
| | - Ksenia Krasileva
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, U.S.A
| | - Regine Kahmann
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
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Brefort T, Tanaka S, Neidig N, Doehlemann G, Vincon V, Kahmann R. Characterization of the largest effector gene cluster of Ustilago maydis. PLoS Pathog 2014; 10:e1003866. [PMID: 24992561 PMCID: PMC4081774 DOI: 10.1371/journal.ppat.1003866] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 11/20/2013] [Indexed: 12/21/2022] Open
Abstract
In the genome of the biotrophic plant pathogen Ustilago maydis, many of the genes coding for secreted protein effectors modulating virulence are arranged in gene clusters. The vast majority of these genes encode novel proteins whose expression is coupled to plant colonization. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results in severe attenuation of virulence. Here we present the functional analysis of this genomic region. We show that a 19A deletion mutant behaves like an endophyte, i.e. is still able to colonize plants and complete the infection cycle. However, tumors, the most conspicuous symptoms of maize smut disease, are only rarely formed and fungal biomass in infected tissue is significantly reduced. The generation and analysis of strains carrying sub-deletions identified several genes significantly contributing to tumor formation after seedling infection. Another of the effectors could be linked specifically to anthocyanin induction in the infected tissue. As the individual contributions of these genes to tumor formation were small, we studied the response of maize plants to the whole cluster mutant as well as to several individual mutants by array analysis. This revealed distinct plant responses, demonstrating that the respective effectors have discrete plant targets. We propose that the analysis of plant responses to effector mutant strains that lack a strong virulence phenotype may be a general way to visualize differences in effector function.
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Affiliation(s)
- Thomas Brefort
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
| | - Shigeyuki Tanaka
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
| | - Nina Neidig
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
| | - Gunther Doehlemann
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
| | - Volker Vincon
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
| | - Regine Kahmann
- Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Marburg, Germany
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Kämper J, Kahmann R, Bölker M, Ma LJ, Brefort T, Saville BJ, Banuett F, Kronstad JW, Gold SE, Müller O, Perlin MH, Wösten HAB, de Vries R, Ruiz-Herrera J, Reynaga-Peña CG, Snetselaar K, McCann M, Pérez-Martín J, Feldbrügge M, Basse CW, Steinberg G, Ibeas JI, Holloman W, Guzman P, Farman M, Stajich JE, Sentandreu R, González-Prieto JM, Kennell JC, Molina L, Schirawski J, Mendoza-Mendoza A, Greilinger D, Münch K, Rössel N, Scherer M, Vranes M, Ladendorf O, Vincon V, Fuchs U, Sandrock B, Meng S, Ho ECH, Cahill MJ, Boyce KJ, Klose J, Klosterman SJ, Deelstra HJ, Ortiz-Castellanos L, Li W, Sanchez-Alonso P, Schreier PH, Häuser-Hahn I, Vaupel M, Koopmann E, Friedrich G, Voss H, Schlüter T, Margolis J, Platt D, Swimmer C, Gnirke A, Chen F, Vysotskaia V, Mannhaupt G, Güldener U, Münsterkötter M, Haase D, Oesterheld M, Mewes HW, Mauceli EW, DeCaprio D, Wade CM, Butler J, Young S, Jaffe DB, Calvo S, Nusbaum C, Galagan J, Birren BW. Insights from the genome of the biotrophic fungal plant pathogen Ustilago maydis. Nature 2006; 444:97-101. [PMID: 17080091 DOI: 10.1038/nature05248] [Citation(s) in RCA: 907] [Impact Index Per Article: 50.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2006] [Accepted: 09/15/2006] [Indexed: 01/30/2023]
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.
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Affiliation(s)
- Jörg Kämper
- Department of Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Strasse, D-35043 Marburg, Germany.
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