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Demoor A, Lacaze I, Ferrari R, Lalanne C, Silar P, Brun S. GUN Mutants: New Weapons To Unravel Ascospore Germination Regulation in the Model Fungus Podospora anserina. Microbiol Spectr 2023; 11:e0146122. [PMID: 36786590 PMCID: PMC10100959 DOI: 10.1128/spectrum.01461-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 09/14/2022] [Indexed: 02/15/2023] Open
Abstract
In Podospora anserina as in many other Ascomycetes, ascospore germination is a regulated process that requires the breaking of dormancy. Despite its importance in survival and dispersal, ascospore germination in filamentous fungi has been poorly investigated, and little is known about its regulation and genetic control. We have designed a positive genetic screen that led to the isolation of mutants showing uncontrolled germination, the GUN (Germination UNcontrolled) mutants. Here, we report on the characterization of the gun1SG (Spontaneous Germination) mutant. We show that gun1SG is mutated in Pa_6_1340, the ortholog of Magnaporthe oryzae Pth2, which encodes a carnitine-acetyltransferase (CAT) involved in the shuttling of acetyl coenzyme A between peroxisomes and mitochondria and which is required for appressorium development. Bioinformatic analysis revealed that the mutated residue (I441) is highly conserved among Fungi and that the mutation has a deleterious impact on the protein function. We show that GUN1 is essential for ascospore germination and that the protein is localized both in mitochondria and in peroxisomes. Finally, epistasis studies allowed us to place GUN1 together with the PaMpk2 MAPK pathway upstream of the PaNox2/PaPls1 complex in the regulation of ascospore germination. In addition, we show that GUN1 plays a role in appressorium functioning. The pivotal role of GUN1, the ortholog of Pth2, in ascospore germination and in appressorium functioning reinforces the idea of a common genetic regulation governing both appressorium development and melanized ascospore germination. Furthermore, we characterize the second CAT encoded in P. anserina genome, Pa_3_7660/GUP1, and we show that the function of both CATs is conserved in P. anserina. IMPORTANCE The regulation of ascospore germination in filamentous fungi has been poorly investigated so far. To unravel new genes involved in this regulation pathway, we conducted a genetic screen in Podospora anserina, and we isolated 57 mutants affected in ascospore germination. Here, we describe the Germination UNcontrolled One (gun1SG) mutant, and we characterize the gene affected. GUN1 is a peroxisomal/mitochondrial carnitine-acetyltransferase required for acetyl coenzyme A shuttling between both organelles, and we show that GUN1 is a pleiotropic gene also involved in appressorium functioning similarly to its ortholog, the pathogenesis factor Pth2, in the plant pathogen Magnaporthe oryzae. Given the similarities in the regulation of appressorium development and ascospore germination, we speculate that discovering new genes controlling ascospore germination in P. anserina may lead to the discovery of new pathogenesis factors in pathogenic fungi. The characterization of GUN1, the ortholog of M. oryzae Pth2, represents a proof of concept.
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Affiliation(s)
- Alexander Demoor
- Université Paris Cité, Laboratoire Interdisciplinaire des Energies de Demain/UMR 8236, Paris, France
| | - Isabelle Lacaze
- Université Paris Cité, Laboratoire Interdisciplinaire des Energies de Demain/UMR 8236, Paris, France
| | - Roselyne Ferrari
- Université Paris Cité, Laboratoire Interdisciplinaire des Energies de Demain/UMR 8236, Paris, France
| | - Christophe Lalanne
- Université Paris Cité, Laboratoire Interdisciplinaire des Energies de Demain/UMR 8236, Paris, France
| | - Philippe Silar
- Université Paris Cité, Laboratoire Interdisciplinaire des Energies de Demain/UMR 8236, Paris, France
| | - Sylvain Brun
- Université Paris Cité, Laboratoire Interdisciplinaire des Energies de Demain/UMR 8236, Paris, France
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Chethana KWT, Jayawardena RS, Chen YJ, Konta S, Tibpromma S, Phukhamsakda C, Abeywickrama PD, Samarakoon MC, Senwanna C, Mapook A, Tang X, Gomdola D, Marasinghe DS, Padaruth OD, Balasuriya A, Xu J, Lumyong S, Hyde KD. Appressorial interactions with host and their evolution. FUNGAL DIVERS 2021. [DOI: 10.1007/s13225-021-00487-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Couturier M, Tangthirasunun N, Ning X, Brun S, Gautier V, Bennati-Granier C, Silar P, Berrin JG. Plant biomass degrading ability of the coprophilic ascomycete fungus Podospora anserina. Biotechnol Adv 2016; 34:976-983. [PMID: 27263000 DOI: 10.1016/j.biotechadv.2016.05.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 05/11/2016] [Accepted: 05/27/2016] [Indexed: 12/22/2022]
Abstract
The degradation of plant biomass is a major challenge towards the production of bio-based compounds and materials. As key lignocellulolytic enzyme producers, filamentous fungi represent a promising reservoir to tackle this challenge. Among them, the coprophilous ascomycete Podospora anserina has been used as a model organism to study various biological mechanisms because its genetics are well understood and controlled. In 2008, the sequencing of its genome revealed a great diversity of enzymes targeting plant carbohydrates and lignin. Since then, a large array of lignocellulose-acting enzymes has been characterized and genetic analyses have enabled the understanding of P. anserina metabolism and development on plant biomass. Overall, these research efforts shed light on P. anserina strategy to unlock recalcitrant lignocellulose deconstruction.
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Affiliation(s)
- Marie Couturier
- INRA, Aix Marseille Université, Polytech Marseille, UMR 1163, Biodiversité et Biotechnologie Fongiques, F-13288 Marseille, France
| | - Narumon Tangthirasunun
- Laboratoire Interdisciplinaire des Energies de Demain, Université Paris Diderot, 35, rue Hélène Brion, F-75205 Paris, France
| | - Xie Ning
- Laboratoire Interdisciplinaire des Energies de Demain, Université Paris Diderot, 35, rue Hélène Brion, F-75205 Paris, France
| | - Sylvain Brun
- Laboratoire Interdisciplinaire des Energies de Demain, Université Paris Diderot, 35, rue Hélène Brion, F-75205 Paris, France
| | - Valérie Gautier
- Laboratoire Interdisciplinaire des Energies de Demain, Université Paris Diderot, 35, rue Hélène Brion, F-75205 Paris, France
| | - Chloé Bennati-Granier
- INRA, Aix Marseille Université, Polytech Marseille, UMR 1163, Biodiversité et Biotechnologie Fongiques, F-13288 Marseille, France
| | - Philippe Silar
- Laboratoire Interdisciplinaire des Energies de Demain, Université Paris Diderot, 35, rue Hélène Brion, F-75205 Paris, France.
| | - Jean-Guy Berrin
- INRA, Aix Marseille Université, Polytech Marseille, UMR 1163, Biodiversité et Biotechnologie Fongiques, F-13288 Marseille, France.
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Lacaze I, Lalucque H, Siegmund U, Silar P, Brun S. Identification of NoxD/Pro41 as the homologue of the p22phox NADPH oxidase subunit in fungi. Mol Microbiol 2014; 95:1006-24. [PMID: 25424886 DOI: 10.1111/mmi.12876] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2014] [Indexed: 11/28/2022]
Abstract
NADPH oxidases (Nox) are membrane complexes that produce O2(-). Researches in mammals, plants and fungi highlight the involvement of Nox-generated ROS in cell proliferation, differentiation and defense. In mammals, the core enzyme gp91(phox)/Nox2 is associated with p22(phox) forming the flavocytochrome b558 ready for activation by a cytosolic complex. Intriguingly, no homologue of the p22(phox) gene has been found in fungal genomes, questioning how the flavoenzyme forms. Using whole genome sequencing combined with phylogenetic analysis and structural studies, we identify the fungal p22(phox) homologue as being mutated in the Podospora anserina mutant IDC(509). Functional studies show that the fungal p22(phox), PaNoxD, acts along PaNox1, but not PaNox2, a second fungal gp91(phox) homologue. Finally, cytological analysis of functional tagged versions of PaNox1, PaNoxD and PaNoxR shows clear co-localization of PaNoxD and PaNox1 and unravel a dynamic assembly of the complex in the endoplasmic reticulum and in the vacuolar system.
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Affiliation(s)
- Isabelle Lacaze
- Univ Paris Diderot, Sorbonne Paris Cité, Institut des Energies de Demain, case courrier 7040 Lamarck, 75205, Paris Cedex 13, France; Univ Paris Sud, Institut de Génétique et Microbiologie, UMR8621, 91405, Orsay Cedex, France
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Kowalczyk JE, Benoit I, de Vries RP. Regulation of plant biomass utilization in Aspergillus. ADVANCES IN APPLIED MICROBIOLOGY 2014; 88:31-56. [PMID: 24767425 DOI: 10.1016/b978-0-12-800260-5.00002-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The ability of fungi to survive in every known biotope, both natural and man-made, relies in part on their ability to use a wide range of carbon sources. Fungi degrade polymeric carbon sources present in the environment (polysaccharides, proteins, and lignins) to use the monomeric components as nutrients. However, the available carbon sources vary strongly in nature, both between biotopes and in time. The degradation of polymeric carbon sources is mediated through the production of a broad range of enzymes, the production of which is tightly controlled by a network of regulators and linked to the activation of catabolic pathways to convert the released monomers. This review summarizes the knowledge of Aspergillus regulators involved in plant biomass utilization.
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Affiliation(s)
| | - Isabelle Benoit
- CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands
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Moribe H, Mekada E. Co-occurrence of tetraspanin and ROS generators: Conservation in protein cross-linking and other developmental processes. WORM 2013; 2:e23415. [PMID: 24058871 PMCID: PMC3704445 DOI: 10.4161/worm.23415] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Accepted: 12/21/2012] [Indexed: 11/19/2022]
Abstract
The nematode exoskeleton, commonly called the cuticle, is a highly structured extracellular matrix mainly composed of collagen. Secreted collagen molecules from the underlying epidermal cells are cross-linked via their tyrosyl residues. Reactive oxygen species (ROS) are required for the cross-linking reaction to produce tyrosyl radicals. The conserved ROS generator enzyme in C. elegans, BLI-3/CeDUOX1, a homolog of dual oxidases (DUOXs), is responsible for production of hydrogen peroxide. The ROS generation system must be properly controlled since ROS are highly reactive molecules that irreversibly inhibit the functions of cellular components such as nucleic acids and proteins. We recently reported that the ROS generation system directed by BLI-3 requires the tetraspanin protein, TSP-15. Herein we outline the process of cuticle development with a focus on the molecular roles of TSP-15 in the BLI-3 system. We also propose the co-occurrence of tetraspanin and ROS generators by convergent evolution.
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Affiliation(s)
- Hiroki Moribe
- Department of Biology; Kurume University School of Medicine; Fukuoka, Japan
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NADPH oxidases regulate septin-mediated cytoskeletal remodeling during plant infection by the rice blast fungus. Proc Natl Acad Sci U S A 2013; 110:3179-84. [PMID: 23382235 DOI: 10.1073/pnas.1217470110] [Citation(s) in RCA: 136] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The rice blast fungus Magnaporthe oryzae infects plants with a specialized cell called an appressorium, which uses turgor to drive a rigid penetration peg through the rice leaf cuticle. Here, we show that NADPH oxidases (Nox) are necessary for septin-mediated reorientation of the F-actin cytoskeleton to facilitate cuticle rupture and plant cell invasion. We report that the Nox2-NoxR complex spatially organizes a heteroligomeric septin ring at the appressorium pore, required for assembly of a toroidal F-actin network at the point of penetration peg emergence. Maintenance of the cortical F-actin network during plant infection independently requires Nox1, a second NADPH oxidase, which is necessary for penetration hypha elongation. Organization of F-actin in appressoria is disrupted by application of antioxidants, whereas latrunculin-mediated depolymerization of appressorial F-actin is competitively inhibited by reactive oxygen species, providing evidence that regulated synthesis of reactive oxygen species by fungal NADPH oxidases directly controls septin and F-actin dynamics.
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Bourdais A, Bidard F, Zickler D, Berteaux-Lecellier V, Silar P, Espagne E. Wood utilization is dependent on catalase activities in the filamentous fungus Podospora anserina. PLoS One 2012; 7:e29820. [PMID: 22558065 PMCID: PMC3338752 DOI: 10.1371/journal.pone.0029820] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 12/06/2011] [Indexed: 01/24/2023] Open
Abstract
Catalases are enzymes that play critical roles in protecting cells against the toxic effects of hydrogen peroxide. They are implicated in various physiological and pathological conditions but some of their functions remain unclear. In order to decipher the role(s) of catalases during the life cycle of Podospora anserina, we analyzed the role of the four monofunctional catalases and one bifunctional catalase-peroxidase genes present in its genome. The five genes were deleted and the phenotypes of each single and all multiple mutants were investigated. Intriguingly, although the genes are differently expressed during the life cycle, catalase activity is dispensable during both vegetative growth and sexual reproduction in laboratory conditions. Catalases are also not essential for cellulose or fatty acid assimilation. In contrast, they are strictly required for efficient utilization of more complex biomass like wood shavings by allowing growth in the presence of lignin. The secreted CATB and cytosolic CAT2 are the major catalases implicated in peroxide resistance, while CAT2 is the major player during complex biomass assimilation. Our results suggest that P. anserina produces external H2O2 to assimilate complex biomass and that catalases are necessary to protect the cells during this process. In addition, the phenotypes of strains lacking only one catalase gene suggest that a decrease of catalase activity improves the capacity of the fungus to degrade complex biomass.
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Affiliation(s)
- Anne Bourdais
- Institut de Génétique et Microbiologie, Univ Paris-Sud, UMR 8621, Orsay, France
- CNRS, Orsay, France
- Institut Génétique et Développement de Rennes, CNRS, UMR 6061, Rennes, France
- UEB Université Rennes 1, IFR 140, Faculté de Médecine, Rennes, France
| | - Frederique Bidard
- Institut de Génétique et Microbiologie, Univ Paris-Sud, UMR 8621, Orsay, France
- CNRS, Orsay, France
| | - Denise Zickler
- Institut de Génétique et Microbiologie, Univ Paris-Sud, UMR 8621, Orsay, France
- CNRS, Orsay, France
| | - Veronique Berteaux-Lecellier
- Institut de Génétique et Microbiologie, Univ Paris-Sud, UMR 8621, Orsay, France
- CNRS, Orsay, France
- Laboratoire d’Excellence « CORAIL », USR 3278 CNRS-EPHE, CRIOBE, BP 1013, Moorea, French Polynesia
| | - Philippe Silar
- Institut de Génétique et Microbiologie, Univ Paris-Sud, UMR 8621, Orsay, France
- CNRS, Orsay, France
- Univ Paris Diderot, Sorbonne Paris Cité, UFR des Sciences du Vivant, Paris, France
| | - Eric Espagne
- Institut de Génétique et Microbiologie, Univ Paris-Sud, UMR 8621, Orsay, France
- * E-mail:
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Requirement of a Tsp2-type tetraspanin for laccase repression and stress resistance in the basidiomycete Cryptococcus neoformans. Appl Environ Microbiol 2011; 78:21-7. [PMID: 22020508 DOI: 10.1128/aem.06072-11] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Fungal laccases have been widely used in industry. The expression of laccase often is repressible by the primary carbon source glucose in many fungi. The underlying basis is largely unclear. We demonstrate here that a gene, TSP2-1, was required for laccase repression by glucose in the basidiomycete Cryptococcus neoformans. TSP2-1 encodes a Tsp2-type tetraspanin. The disruption of TSP2-1 resulted in constant melanin formation and the expression of the laccase gene LAC1. This derepression phenotype was restorable by 10 mM exogenous cyclic AMP (cAMP). A capsule defect in the mutant tsp2-1Δ also was restored by cAMP. The results indicate an interaction of Tsp2-1 with the cAMP-dependent protein kinase A (PKA) pathway that has been shown to modulate laccase repression and capsule biosynthesis in this fungus. Other roles of TSP2-1, e.g., in maintaining cell membrane integrity and stress resistance, also were defined. This work reveals a Tsp2-1-dependent glucose repression in C. neoformans. The function of Tsp2-type tetraspanin Tsp2-1 is described for the first time.
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Bidard F, Aït Benkhali J, Coppin E, Imbeaud S, Grognet P, Delacroix H, Debuchy R. Genome-wide gene expression profiling of fertilization competent mycelium in opposite mating types in the heterothallic fungus Podospora anserina. PLoS One 2011; 6:e21476. [PMID: 21738678 PMCID: PMC3125171 DOI: 10.1371/journal.pone.0021476] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 05/29/2011] [Indexed: 12/15/2022] Open
Abstract
Background Mating-type loci in yeasts and ascomycotan filamentous fungi (Pezizomycotina) encode master transcriptional factors that play a critical role in sexual development. Genome-wide analyses of mating-type-specification circuits and mating-type target genes are available in Saccharomyces cerevisiae and Schizosaccharomyces pombe; however, no such analyses have been performed in heterothallic (self-incompatible) Pezizomycotina. The heterothallic fungus Podospora anserina serves as a model for understanding the basic features of mating-type control. Its mat+ and mat− mating types are determined by dissimilar allelic sequences. The mat− sequence contains three genes, designated FMR1, SMR1 and SMR2, while the mat+ sequence contains one gene, FPR1. FMR1 and FPR1 are the major regulators of fertilization, and this study presents a genome-wide view of their target genes and analyzes their target gene regulation. Methodology/Principal Findings The transcriptomic profiles of the mat+ and mat− strains revealed 157 differentially transcribed genes, and transcriptomic analysis of fmr1− and fpr1− mutant strains was used to determine the regulatory actions exerted by FMR1 and FPR1 on these differentially transcribed genes. All possible combinations of transcription repression and/or activation by FMR1 and/or FPR1 were observed. Furthermore, 10 additional mating-type target genes were identified that were up- or down-regulated to the same level in mat+ and mat− strains. Of the 167 genes identified, 32 genes were selected for deletion, which resulted in the identification of two genes essential for the sexual cycle. Interspecies comparisons of mating-type target genes revealed significant numbers of orthologous pairs, although transcriptional profiles were not conserved between species. Conclusions/Significance This study represents the first comprehensive genome-wide analysis of mating-type direct and indirect target genes in a heterothallic filamentous fungus. Mating-type transcription factors have many more target genes than are found in yeasts and exert a much greater diversity of regulatory actions on target genes, most of which are not directly related to mating.
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Affiliation(s)
- Frédérique Bidard
- Univ Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France
- CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
| | - Jinane Aït Benkhali
- Univ Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France
- CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
| | - Evelyne Coppin
- Univ Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France
- CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
| | - Sandrine Imbeaud
- CNRS, Centre de Génétique Moléculaire FRE3144, GODMAP, Gif sur Yvette, France
| | - Pierre Grognet
- Univ Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France
- UFR des Sciences du Vivant, Université Paris 7-Denis Diderot, Paris, France
| | - Hervé Delacroix
- CNRS, Centre de Génétique Moléculaire FRE3144, GODMAP, Gif sur Yvette, France
- Univ Paris-Sud, Orsay, France
| | - Robert Debuchy
- Univ Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France
- CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
- * E-mail:
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Heller J, Tudzynski P. Reactive oxygen species in phytopathogenic fungi: signaling, development, and disease. ANNUAL REVIEW OF PHYTOPATHOLOGY 2011; 49:369-90. [PMID: 21568704 DOI: 10.1146/annurev-phyto-072910-095355] [Citation(s) in RCA: 304] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Reactive oxygen species (ROS) play a major role in pathogen-plant interactions: recognition of a pathogen by the plant rapidly triggers the oxidative burst, which is necessary for further defense reactions. The specific role of ROS in pathogen defense is still unclear. Studies on the pathogen so far have focused on the importance of the oxidative stress response (OSR) systems to overcome the oxidative burst or of its avoidance by effectors. This review focuses on the role of ROS for fungal virulence and development. In the recent years, it has become obvious that (a) fungal OSR systems might not have the predicted crucial role in pathogenicity, (b) fungal pathogens, especially necrotrophs, can actively contribute to the ROS level in planta and even take advantage of the host's response, (c) fungi possess superoxide-generating NADPH oxidases similar to mammalian Nox complexes that are important for pathogenicity; however, recent data indicate that they are not directly involved in pathogen-host communication but in fungal differentiation processes that are necessary for virulence.
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Affiliation(s)
- Jens Heller
- Molecular Biology and Biotechnology of Fungi, Institute of Biology and Biotechnology of Plants, Westfälische Wilhelms-Universität Münster, Germany.
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Brun S, Malagnac F, Bidard F, Lalucque H, Silar P. Functions and regulation of the Nox family in the filamentous fungus Podospora anserina: a new role in cellulose degradation. Mol Microbiol 2009; 74:480-96. [PMID: 19775249 DOI: 10.1111/j.1365-2958.2009.06878.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
NADPH oxidases are enzymes that produce reactive oxygen species. Studies in mammals, plants and fungi have shown that they play important roles in differentiation, defence, host/pathogen interaction and mutualistic symbiosis. In this paper, we have identified a Podospora anserina mutant strain impaired for processes controlled by PaNox1 and PaNox2, the two Nox isoforms characterized in this model ascomycete. We show that the gene mutated is PaNoxR, the homologue of the gene encoding the regulatory subunit p67(phox), conserved in mammals and fungi, and that PaNoxR regulates both PaNox1 and PaNox2. Genome sequence analysis of P. anserina reveals that this fungus posses a third Nox isoform, PaNox3, related to human Nox5/Duox and plant Rboh. We have generated a knock-out mutant of PaNox3 and report that PaNox3 plays a minor role in P. anserina, if any. We show that PaNox1 and PaNox2 play antagonist roles in cellulose degradation. Finally, we report for the first time that a saprobic fungus, P. anserina, develops special cell structures dedicated to breach and to exploit a solid cellulosic substrate, cellophane. Importantly, as for similar structures present in some plant pathogens, their proper differentiation requires PaNox1, PaNox2, PaNoxR and the tetraspanin PaPls1.
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Affiliation(s)
- Sylvain Brun
- UFR des Sciences du Vivant, Univ Paris 7 Denis Diderot, 75013 Paris, France
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