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Ma L, Ma J, Tian Y, Li X, Tai B, Xing F. Fus3 Interacts with Gal83, Revealing the MAPK Crosstalk to Snf1/AMPK to Regulate Secondary Metabolic Substrates in Aspergillus flavus. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:10065-10075. [PMID: 38634532 DOI: 10.1021/acs.jafc.4c01229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
Aflatoxins (AFs), highly carcinogenic natural products, are produced by the secondary metabolism of fungi such as Aspergillus flavus. Essential for the fungi to respond to environmental changes and aflatoxin synthesis, the pheromone mitogen-activated protein kinase (MAPK) is a potential regulator of aflatoxin biosynthesis. However, the mechanism by which pheromone MAPK regulates aflatoxin biosynthesis is not clear. Here, we showed Gal83, a new target of Fus3, and identified the pheromone Fus3-MAPK signaling pathway as a regulator of the Snf1/AMPK energy-sensing pathway modulating aflatoxins synthesis substrates. The screening for Fus3 target proteins identified the β subunit of Snf1/AMPK complexes using tandem affinity purification and multiomics. This subunit physically interacted with Fus3 both in vivo and in vitro and received phosphorylation from Fus3. Although the transcript levels of aflatoxin synthesis genes were not noticeably downregulated in both gal83 and fus3 deletion mutant strains, the levels of aflatoxin B1 and its synthesis substrates and gene expression levels of primary metabolizing enzymes were significantly reduced. This suggests that both the Fus3-MAPK and Snf1/AMPK pathways respond to energy signals. In conclusion, all the evidence unlocks a novel pathway of Fus3-MAPK to regulate AFs synthesis substrates by cross-talking with the Snf1/AMPK complexes.
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Affiliation(s)
- Longxue Ma
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences / Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, P. R. China
| | - Junning Ma
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences / Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, P. R. China
| | - Yuanyuan Tian
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences / Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, P. R. China
| | - Xu Li
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences / Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, P. R. China
| | - Bowen Tai
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences / Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, P. R. China
| | - Fuguo Xing
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences / Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, P. R. China
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2
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Schalamun M, Hinterdobler W, Schinnerl J, Brecker L, Schmoll M. The transcription factor STE12 influences growth on several carbon sources and production of dehydroacetic acid (DHAA) in Trichoderma reesei. Sci Rep 2024; 14:9625. [PMID: 38671155 PMCID: PMC11053031 DOI: 10.1038/s41598-024-59511-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
The filamentous ascomycete Trichoderma reesei, known for its prolific cellulolytic enzyme production, recently also gained attention for its secondary metabolite synthesis. Both processes are intricately influenced by environmental factors like carbon source availability and light exposure. Here, we explore the role of the transcription factor STE12 in regulating metabolic pathways in T. reesei in terms of gene regulation, carbon source utilization and biosynthesis of secondary metabolites. We show that STE12 is involved in regulating cellulase gene expression and growth on carbon sources associated with iron homeostasis. STE12 impacts gene regulation in a light dependent manner on cellulose with modulation of several CAZyme encoding genes as well as genes involved in secondary metabolism. STE12 selectively influences the biosynthesis of the sorbicillinoid trichodimerol, while not affecting the biosynthesis of bisorbibutenolide, which was recently shown to be regulated by the MAPkinase pathway upstream of STE12 in the signaling cascade. We further report on the biosynthesis of dehydroacetic acid (DHAA) in T. reesei, a compound known for its antimicrobial properties, which is subject to regulation by STE12. We conclude, that STE12 exerts functions beyond development and hence contributes to balance the energy distribution between substrate consumption, reproduction and defense.
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Affiliation(s)
- Miriam Schalamun
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430, Tulln, Austria
| | - Wolfgang Hinterdobler
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430, Tulln, Austria
- MyPilz GmbH, Wienerbergstrasse 55/13-15, 1120, Vienna, Austria
| | - Johann Schinnerl
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030, Vienna, Austria
| | - Lothar Brecker
- Department of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Monika Schmoll
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430, Tulln, Austria.
- Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, University of Vienna, Djerassiplatz 1, 1030, Vienna, Austria.
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Calvo AM, Dabholkar A, Wyman EM, Lohmar JM, Cary JW. Regulatory functions of homeobox domain transcription factors in fungi. Appl Environ Microbiol 2024; 90:e0220823. [PMID: 38421174 PMCID: PMC10952592 DOI: 10.1128/aem.02208-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024] Open
Abstract
Homeobox domain (HD) proteins present a crucial involvement in morphological differentiation and other functions in eukaryotes. Most HD genes encode transcription factors (TFs) that orchestrate a regulatory role in cellular and developmental decisions. In fungi, multiple studies have increased our understanding of these important HD regulators in recent years. These reports have revealed their role in fungal development, both sexual and asexual, as well as their importance in governing other biological processes in these organisms, including secondary metabolism, pathogenicity, and sensitivity to environmental stresses. Here, we provide a comprehensive review of the current knowledge on the regulatory roles of HD-TFs in fungi, with a special focus on Aspergillus species.
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Affiliation(s)
- A. M. Calvo
- Department of Biological Sciences, Northern Illinois University, Dekalb, Illinois, USA
| | - A. Dabholkar
- Department of Biological Sciences, Northern Illinois University, Dekalb, Illinois, USA
| | - E. M. Wyman
- Department of Biological Sciences, Northern Illinois University, Dekalb, Illinois, USA
| | - J. M. Lohmar
- Food and Feed Safety Research Unit, USDA/ARS, Southern Regional Research Center, New Orleans, Louisiana, USA
| | - J. W. Cary
- Food and Feed Safety Research Unit, USDA/ARS, Southern Regional Research Center, New Orleans, Louisiana, USA
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4
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Essadik I, Boucher C, Bobée C, Cabet É, Gautier V, Lalucque H, Silar P, Chapeland-Leclerc F, Ruprich-Robert G. Mutations in Podospora anserina MCM1 and VelC Trigger Spontaneous Development of Barren Fruiting Bodies. J Fungi (Basel) 2024; 10:79. [PMID: 38276025 PMCID: PMC10819945 DOI: 10.3390/jof10010079] [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: 12/05/2023] [Revised: 01/12/2024] [Accepted: 01/17/2024] [Indexed: 01/27/2024] Open
Abstract
The ascomycete Podospora anserina is a heterothallic filamentous fungus found mainly on herbivore dung. It is commonly used in laboratories as a model system, and its complete life cycle lasting eight days is well mastered in vitro. The main objective of our team is to understand better the global process of fruiting body development, named perithecia, induced normally in this species by fertilization. Three allelic mutants, named pfd3, pfd9, and pfd23 (for "promoting fruiting body development") obtained by UV mutagenesis, were selected in view of their abilities to promote barren perithecium development without fertilization. By complete genome sequencing of pfd3 and pfd9, and mutant complementation, we identified point mutations in the mcm1 gene as responsible for spontaneous perithecium development. MCM1 proteins are MADS box transcription factors that control diverse developmental processes in plants, metazoans, and fungi. We also identified using the same methods a mutation in the VelC gene as responsible for spontaneous perithecium development in the vacua mutant. The VelC protein belongs to the velvet family of regulators involved in the control of development and secondary metabolite production. A key role of MCM1 and VelC in coordinating the development of P. anserina perithecia with gamete formation and fertilization is highlighted.
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Affiliation(s)
| | | | | | | | | | | | - Philippe Silar
- Université Paris Cité, CNRS, UMR 8236—LIED, F-75013 Paris, France (C.B.); (É.C.); (V.G.); (H.L.); (F.C.-L.)
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Xie M, Bai N, Yang X, Liu Y, Zhang KQ, Yang J. Fus3 regulates asexual development and trap morphogenesis in the nematode-trapping fungus Arthrobotrys oligospora. iScience 2023; 26:107404. [PMID: 37609635 PMCID: PMC10440713 DOI: 10.1016/j.isci.2023.107404] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 04/07/2023] [Accepted: 07/12/2023] [Indexed: 08/24/2023] Open
Abstract
Mitogen-activated protein kinase (MAPK) Fus3 is an essential regulator of cell differentiation and virulence in fungal pathogens of plants and animals. However, the function and regulatory mechanism of MAPK signaling in nematode-trapping (NT) fungi remain largely unknown. NT fungi can specialize in the formation of "traps", an important indicator of transition from a saprophytic to a predatory lifestyle. Here, we characterized an orthologous Fus3 in a typical NT fungus Arthrobotrys oligospora using multi-phenotypic analysis and multi-omics approaches. Our results showed that Fus3 plays an important role in asexual growth and development, conidiation, stress response, DNA damage, autophagy, and secondary metabolism. Importantly, Fus3 plays an indispensable role in hyphal fusion, trap morphogenesis, and nematode predation. Moreover, we constructed the regulatory networks of Fus3 by means of transcriptomic and yeast two-hybrid techniques. This study provides insights into the mechanism of MAPK signaling in asexual development and pathogenicity of NT fungi.
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Affiliation(s)
- Meihua Xie
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, P.R. China
- School of Resource, Environment and Chemistry, Chuxiong Normal University, Chuxiong 675000, P.R. China
| | - Na Bai
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, P.R. China
| | - Xuewei Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, P.R. China
| | - Yankun Liu
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, P.R. China
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, P.R. China
| | - Jinkui Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, P.R. China
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6
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Bai N, Xie M, Liu Q, Wang W, Liu Y, Yang J. AoSte12 Is Required for Mycelial Development, Conidiation, Trap Morphogenesis, and Secondary Metabolism by Regulating Hyphal Fusion in Nematode-Trapping Fungus Arthrobotrys oligospora. Microbiol Spectr 2023; 11:e0395722. [PMID: 36786575 PMCID: PMC10101105 DOI: 10.1128/spectrum.03957-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 01/23/2023] [Indexed: 02/15/2023] Open
Abstract
Nematode-trapping (NT) fungi are a unique group of carnivorous microorganisms that can capture and digest nematodes by producing ingenious trapping devices (traps). Arthrobotrys oligospora, a representative NT fungus, can develop adhesive three-dimensional networks for nematode predation. Hyphal fusion is indispensable for the trap formation of A. oligospora. Here, we characterized an orthologous Ste12 protein (AoSte12) in A. oligospora via gene disruption, DNA affinity purification sequencing (DAP-Seq), and multi-omics approaches. The disruption of the Aoste12 gene caused an increase in hyphal fusion and resulted in defects in mycelial growth, conidiation, trap morphology, and stress resistance, as well as reducing the number of nuclei and lipid droplet accumulation. Moreover, transcriptome and DAP-Seq analysis revealed that AoSte12 was involved in cellular processes associated with growth, cell fusion, the tricarboxylic acid cycle, vesicles, actin filaments, and lipid metabolism. In addition, combining metabolome with transcriptome and DAP-Seq analysis indicated that AoSte12 was involved in the mitogen-activated protein kinase signaling pathway, lipid metabolism, and secondary metabolites. A yeast two-hybrid assay revealed that AoSte12 can interact with diverse proteins, such as the MAK-2 orthologue protein Fus3, the vacuolar sorting protein Pep3, and UDP-glycosyltransferase. Our results suggest that AoSte12 plays an indispensable role in hyphal fusion and thus regulates sporulation and trap morphogenesis. These results provide deep insights into the connection between hyphal fusion and trap formation in NT fungi. IMPORTANCE Nematode-trapping (NT) fungi are an important natural enemy of nematodes and can capture their prey by producing traps. Hyphal anastomosis and fusion are important for mycelial growth and the colony morphological development of filamentous fungi and are also crucial for the trap morphogenesis of NT fungi. Arthrobotrys oligospora can form complex three-dimensional networks (traps) when sensing the presence of nematodes. This study revealed that AoSte12 is indispensable for hyphal fusion and that it regulates mycelial growth, conidiation, trap morphogenesis, stress resistance, the number of nuclei, and lipid droplet accumulation in A. oligospora. In addition, DNA affinity purification sequencing, transcriptome, and metabolome analyses further revealed that AoSte12 is involved in the mitogen-activated protein kinase pathway, lipid metabolism, and secondary metabolism. Overall, these findings expand the important role of AoSte12 in NT fungus A. oligospora and provide a broad foundation for elucidating the regulatory mechanism of trap development and the lifestyle transitions of pathogenic fungi.
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Affiliation(s)
- Na Bai
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, People’s Republic of China
- School of Life Sciences, Yunnan University, Kunming, People’s Republic of China
| | - Meihua Xie
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, People’s Republic of China
- School of Life Sciences, Yunnan University, Kunming, People’s Republic of China
| | - Qianqian Liu
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, People’s Republic of China
- School of Life Sciences, Yunnan University, Kunming, People’s Republic of China
| | - Wenjie Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, People’s Republic of China
- School of Life Sciences, Yunnan University, Kunming, People’s Republic of China
| | - Yankun Liu
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, People’s Republic of China
- School of Life Sciences, Yunnan University, Kunming, People’s Republic of China
| | - Jinkui Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, People’s Republic of China
- School of Life Sciences, Yunnan University, Kunming, People’s Republic of China
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7
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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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Nowrousian M. The Role of Chromatin and Transcriptional Control in the Formation of Sexual Fruiting Bodies in Fungi. Microbiol Mol Biol Rev 2022; 86:e0010422. [PMID: 36409109 PMCID: PMC9769939 DOI: 10.1128/mmbr.00104-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Fungal fruiting bodies are complex, three-dimensional structures that arise from a less complex vegetative mycelium. Their formation requires the coordinated action of many genes and their gene products, and fruiting body formation is accompanied by major changes in the transcriptome. In recent years, numerous transcription factor genes as well as chromatin modifier genes that play a role in fruiting body morphogenesis were identified, and through research on several model organisms, the underlying regulatory networks that integrate chromatin structure, gene expression, and cell differentiation are becoming clearer. This review gives a summary of the current state of research on the role of transcriptional control and chromatin structure in fruiting body development. In the first part, insights from transcriptomics analyses are described, with a focus on comparative transcriptomics. In the second part, examples of more detailed functional characterizations of the role of chromatin modifiers and/or transcription factors in several model organisms (Neurospora crassa, Aspergillus nidulans, Sordaria macrospora, Coprinopsis cinerea, and Schizophyllum commune) that have led to a better understanding of regulatory networks at the level of chromatin structure and transcription are discussed.
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Affiliation(s)
- Minou Nowrousian
- Department of Molecular and Cellular Botany, Ruhr University Bochum, Bochum, Germany
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9
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Wilson AM, Wingfield MJ, Wingfield BD. Truncation of MAT1-2-7 Deregulates Developmental Pathways Associated with Sexual Reproduction in Huntiella omanensis. Microbiol Spectr 2022; 10:e0142522. [PMID: 36154282 PMCID: PMC9602353 DOI: 10.1128/spectrum.01425-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 09/07/2022] [Indexed: 12/30/2022] Open
Abstract
The MAT1-1-1 and MAT1-2-1 genes are thought to be the master regulators of sexual development in most ascomycete fungi, and they are often essential for this process. In contrast, it has been suggested that the secondary mating-type genes act to calibrate the sexual cycle and can be dispensable. Recent functional characterization of genes such as Aspergillus fumigatus MAT1-2-4, Huntiella omanensis MAT1-2-7, and Botrytis cinerea MAT1-1-5 has, however, shown that these secondary genes may play more central roles in the sexual pathway and are essential for the production of mature fruiting structures. We used a comparative transcriptome sequencing (RNA-seq) experiment to show that the truncation of MAT1-2-7 in the wood inhabiting H. omanensis residing in the Ceratocystidaceae is associated with the differential expression of approximately 25% of all the genes present in the genome, including the transcriptional regulators ste12, wc-2, sub1, VeA, HMG8, and pro1. This suggests that MAT1-2-7 may act as a transcription factor and that ΔMAT1-2-7 mutant sterility is the result of layered deregulation of a variety of signaling and developmental pathways. This study is one of only a few that details the functional characterization of a secondary MAT gene in a nonmodel species. Given that this gene is present in other Ceratocystidaceae species and that there are diverse secondary MAT genes present throughout the Pezizomycotina, further investigation into this gene and others like it will provide a clearer understanding of sexual development in these eukaryotes. IMPORTANCE Secondary mating-type genes are being described almost as quickly as new fungal genomes are being sequenced. Understanding the functions of these genes has lagged behind their description, in part due to limited taxonomic distribution, lack of conserved functional domains, and difficulties with regard to genetic manipulation protocols. This study aimed to address this by investigating a novel mating-type gene, MAT1-2-7, for which two independent mutant strains were generated in a previous study. We characterized the molecular response to the truncation of this gene in a nonmodel, wood-infecting fungus and showed that it resulted in widespread differential expression throughout the transcriptome of this fungus. This suggests that secondary MAT genes may play a more important role than previously thought. This study also emphasizes the need for further research into the life cycles of nonmodel fungi, which often exhibit unique features that are very different from the systems understood from model species.
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Affiliation(s)
- A. M. Wilson
- Forestry & Agricultural Biotechnology Institute (FABI), Department of Biochemistry, Genetics & Microbiology, University of Pretoria, Pretoria, South Africa
| | - M. J. Wingfield
- Forestry & Agricultural Biotechnology Institute (FABI), Department of Biochemistry, Genetics & Microbiology, University of Pretoria, Pretoria, South Africa
| | - B. D. Wingfield
- Forestry & Agricultural Biotechnology Institute (FABI), Department of Biochemistry, Genetics & Microbiology, University of Pretoria, Pretoria, South Africa
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10
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Yu L, Yang Y, Xiong D, Tian C. Phosphoproteomic and Metabolomic Profiling Uncovers the Roles of CcPmk1 in the Pathogenicity of Cytospora chrysosperma. Microbiol Spectr 2022; 10:e0017622. [PMID: 35735975 PMCID: PMC9430611 DOI: 10.1128/spectrum.00176-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 04/23/2022] [Indexed: 11/20/2022] Open
Abstract
Pmk1, a highly conserved pathogenicity-related mitogen-activated protein kinase (MAPK) in pathogenic fungi, is phosphorylated and activated by MAP2K and acts as a global regulator of fungal infection and invasive growth by modulating downstream targets. However, the hierarchical CcPmk1 regulatory network in Cytospora chrysosperma, the main causal agent of canker disease in many woody plant species, is still unclear. In this study, we analyzed and compared the phosphoproteomes and metabolomes of ΔCcPmk1 and wild-type strains and identified pathogenicity-related downstream targets of CcPmk1. We found that CcPmk1 could interact with the downstream homeobox transcription factor CcSte12 and affect its phosphorylation. In addition, the ΔCcSte12 displayed defective phenotypes that were similar to yet not identical to that of the ΔCcPmk1 and included significantly reduced fungal growth, conidiation, and virulence. Remarkably, CcPmk1 could phosphorylate proteins translated from a putative secondary metabolism-related gene cluster, which is specific to C. chrysosperma, and the phosphorylation of several peptides was completely abolished in the ΔCcPmk1. Functional analysis of the core gene (CcPpns1) in this gene cluster revealed its essential roles in fungal growth and virulence. Metabolomic analysis showed that amino acid metabolism and biosynthesis of secondary metabolites, lipids, and lipid-like molecules significantly differed between wild type and ΔCcPmk1. Importantly, most of the annotated lipids and lipid-like molecules were significantly downregulated in the ΔCcPmk1 compared to the wild type. Collectively, these findings suggest that CcPmk1 may regulate a small number of downstream master regulators to control fungal growth, conidiation, and virulence in C. chrysosperma. IMPORTANCE Understanding the pathogenic mechanisms of plant pathogens is a prerequisite to developing effective disease-control methods. The Pmk1 MAPK is highly conserved among phytopathogenic fungi and acts as a global regulator of fungal pathogenicity by modulating downstream transcription factors or other components. However, the regulatory network of CcPmk1 from C. chrysosperma remains enigmatic. The present data provide evidence that the core pathogenicity regulator CcPmk1 modulates a few downstream master regulators to control fungal virulence in C. chrysosperma through transcription or phosphorylation and that CcPmk1 may be a potential target for disease control.
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Affiliation(s)
- Lu Yu
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Yuchen Yang
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Dianguang Xiong
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing, China
| | - Chengming Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing, China
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11
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The Gβ-like Protein AfCpcB Affects Sexual Development, Response to Oxidative Stress and Phagocytosis by Alveolar Macrophages in Aspergillus fumigatus. J Fungi (Basel) 2022; 8:jof8010056. [PMID: 35049996 PMCID: PMC8777951 DOI: 10.3390/jof8010056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 12/26/2021] [Accepted: 01/04/2022] [Indexed: 12/17/2022] Open
Abstract
G-protein signaling is important for signal transduction, allowing various stimuli that are external to a cell to affect its internal molecules. In Aspergillus fumigatus, the roles of Gβ-like protein CpcB on growth, asexual development, drug sensitivity, and virulence in a mouse model have been previously reported. To gain a deeper insight into Aspergillus fumigatus sexual development, the ΔAfcpcB strain was generated using the supermater AFB62 strain and crossed with AFIR928. This cross yields a decreased number of cleistothecia, including few ascospores. The sexual reproductive organ-specific transcriptional analysis using RNAs from the cleistothecia (sexual fruiting bodies) indicated that the CpcB is essential for the completion of sexual development by regulating the transcription of sexual genes, such as veA, steA, and vosA. The ΔAfcpcB strain revealed increased resistance to oxidative stress by regulating genes for catalase, peroxiredoxin, and ergosterol biosynthesis. The ΔAfcpcB strain showed decreased uptake by alveolar macrophages in vitro, decreased sensitivity to Congo red, decreased expression of cell wall genes, and increased expression of the hydrophobin genes. Taken together, these findings indicate that AfCpcB plays important roles in sexual development, phagocytosis by alveolar macrophages, biosynthesis of the cell wall, and oxidative stress response.
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12
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Wilson AM, Wilken PM, Wingfield MJ, Wingfield BD. Genetic Networks That Govern Sexual Reproduction in the Pezizomycotina. Microbiol Mol Biol Rev 2021; 85:e0002021. [PMID: 34585983 PMCID: PMC8485983 DOI: 10.1128/mmbr.00020-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Sexual development in filamentous fungi is a complex process that relies on the precise control of and interaction between a variety of genetic networks and pathways. The mating-type (MAT) genes are the master regulators of this process and typically act as transcription factors, which control the expression of genes involved at all stages of the sexual cycle. In many fungi, the sexual cycle typically begins when the mating pheromones of one mating type are recognized by a compatible partner, followed by physical interaction and fertilization. Subsequently, highly specialized sexual structures are formed, within which the sexual spores develop after rounds of meiosis and mitosis. These spores are then released and germinate, forming new individuals that initiate new cycles of growth. This review provides an overview of the known genetic networks and pathways that are involved in each major stage of the sexual cycle in filamentous ascomycete fungi.
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Affiliation(s)
- Andi M. Wilson
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - P. Markus Wilken
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Michael J. Wingfield
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Brenda D. Wingfield
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
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13
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Lan N, Ye S, Hu C, Chen Z, Huang J, Xue W, Li S, Sun X. Coordinated Regulation of Protoperithecium Development by MAP Kinases MAK-1 and MAK-2 in Neurospora crassa. Front Microbiol 2021; 12:769615. [PMID: 34899653 PMCID: PMC8662359 DOI: 10.3389/fmicb.2021.769615] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 10/25/2021] [Indexed: 11/18/2022] Open
Abstract
Mitogen-activated protein (MAP) kinase pathways function as signaling hubs that are integral for many essential cellular processes, including sexual development. The molecular mechanisms and cross-talk between PR and CWI MAP kinase pathways have been extensively studied during asexual development. However, if these can be extended to sexual development remains elusive. By analyzing genome-wide transcriptional responses to deletion of each of two MAP kinase coding genes mak-2 (PR-MAP kinase pathway) and mak-1 (CWI-MAP kinase pathway) in Neurospora crassa during protoperithecium formation, 430 genes co-regulated by the MAK-1 and MAK-2 proteins were found, functionally enriched at integral components of membrane and oxidoreductase. These genes include 13 functionally known genes participating in sexual development (app, poi-2, stk-17, fsd-1, vsd-8, and NCU03863) and melanin synthesis (per-1, pkh-1, pkh-2, mld-1, scy-1, trn-2, and trn-1), as well as a set of functionally unknown genes. Phenotypic analysis of deletion mutants for the functionally unknown genes revealed that 12 genes were essential for female fertility. Among them, single-gene deletion mutants for NCU07743 (named as pfd-1), NCU02250 (oli), and NCU05948 (named as pfd-2) displayed similar protoperithecium development defects as the Δmak-1 and Δmak-2 mutants, failing to form protoperithecium. Western blotting analysis showed that both phosphorylated and total MAK-1 proteins were virtually abolished in the Δnrc-1, Δmek-2, and Δmak-2 mutants, suggesting that the posttranscriptional regulation of MAK-1 is dependent on the PR-MAP kinase pathway during the protoperithecium development. Taken together, this study revealed the regulatory roles and cross-talk between PR and CWI-MAP kinase pathways during protoperithecium development.
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Affiliation(s)
- Nan Lan
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Shuting Ye
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Chengcheng Hu
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Zhiling Chen
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Jun Huang
- Shandong Jinniu Group Company, Ltd., Jinan, China
| | - Wei Xue
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Shaojie Li
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xianyun Sun
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
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14
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Fan Y, Zhang W, Chen Y, Xiang M, Liu X. DdaSTE12 is involved in trap formation, ring inflation, conidiation, and vegetative growth in the nematode-trapping fungus Drechslerella dactyloides. Appl Microbiol Biotechnol 2021; 105:7379-7393. [PMID: 34536100 DOI: 10.1007/s00253-021-11455-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 07/06/2021] [Accepted: 07/09/2021] [Indexed: 11/28/2022]
Abstract
Ste12 transcription factors, downstream of mitogen-activated protein kinase (MAPK) signalling pathways, are exclusively found in the fungal kingdom and regulate fungal mating, development, and pathogenicity. The nematode-trapping fungus Drechslerella dactyloides can capture free-living nematodes using constricting rings by cell inflation within 1 s when stimulated by nematodes entering the rings. The MAPK signalling pathways are involved in the trap formation of nematode-trapping fungi, but their downstream regulation is not clearly understood. In this study, disruption of the DdaSTE12 gene in D. dactyloides disabled cell inflation of constricting rings and led to an inability to capture nematodes. The number of septa of constricting rings and the ring cell vacuoles were changed in ΔDdaSTE12. Compared with the wild type, ΔDdaSTE12 reduced trap formation, conidiation, and vegetative growth by 79.3%, 80.3%, and 21.5%, respectively. The transcriptomes of ΔDdaSTE12-3, compared with those of the wild type, indicated that the expression of genes participating in trap formation processes, including signal transduction (Gpa2 and a 7-transmembrane receptor), vesicular transport and cell fusion (MARVEL domain-containing proteins), and nematode infection (PEX11 and CFEM domain-containing proteins), is regulated by DdaSTE12. The results suggest that DdaSTE12 is involved in trap formation and ring cell inflation, as well as conidiation and vegetative growth, by regulating a wide range of downstream functions. Our findings expanded the roles of Ste12 homologous transcription factors in the development of constricting rings and provided new insights into the downstream regulation of the MAPK signalling pathway involved in nematode predation. KEY POINTS: • DdaSTE12 was the first gene disrupted in D. dactyloides. • DdaSTE12 is related to ring cell inflation, vegetative growth, and conidiation. • DdaSTE12 deletion resulted in defects in trap formation and ring development.
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Affiliation(s)
- Yani Fan
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, No. 3 Park 1, Beichen West Rd., Chaoyang District, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Weiwei Zhang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, No. 3 Park 1, Beichen West Rd., Chaoyang District, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yue Chen
- Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Meichun Xiang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, No. 3 Park 1, Beichen West Rd., Chaoyang District, Beijing, 100101, China.
| | - Xingzhong Liu
- Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, China.
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15
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Chen SA, Lin HC, Schroeder FC, Hsueh YP. Prey sensing and response in a nematode-trapping fungus is governed by the MAPK pheromone response pathway. Genetics 2021; 217:5995318. [PMID: 33724405 DOI: 10.1093/genetics/iyaa008] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 11/02/2020] [Indexed: 12/19/2022] Open
Abstract
Detection of surrounding organisms in the environment plays a major role in the evolution of interspecies interactions, such as predator-prey relationships. Nematode-trapping fungi (NTF) are predators that develop specialized trap structures to capture, kill, and consume nematodes when food sources are limited. Despite the identification of various factors that induce trap morphogenesis, the mechanisms underlying the differentiation process have remained largely unclear. Here, we demonstrate that the highly conserved pheromone-response MAPK pathway is essential for sensing ascarosides, a conserved molecular signature of nemaotdes, and is required for the predatory lifestyle switch in the NTF Arthrobotrys oligospora. Gene deletion of STE7 (MAPKK) and FUS3 (MAPK) abolished nematode-induced trap morphogenesis and conidiation and impaired the growth of hyphae. The conserved transcription factor Ste12 acting downstream of the pheromone-response pathway also plays a vital role in the predation of A. oligospora. Transcriptional profiling of a ste12 mutant identified a small subset of genes with diverse functions that are Ste12 dependent and could trigger trap differentiation. Our work has revealed that A. oligospora perceives and interprets the ascarosides produced by nematodes via the conserved pheromone signaling pathway in fungi, providing molecular insights into the mechanisms of communication between a fungal predator and its nematode prey.
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Affiliation(s)
- Sheng-An Chen
- Institute of Molecular Biology, Academia Sinica, Nangang, Taipei 11529, Taiwan
| | - Hung-Che Lin
- Institute of Molecular Biology, Academia Sinica, Nangang, Taipei 11529, Taiwan
| | - Frank C Schroeder
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA.,Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Yen-Ping Hsueh
- Institute of Molecular Biology, Academia Sinica, Nangang, Taipei 11529, Taiwan
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16
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Zuriegat Q, Zheng Y, Liu H, Wang Z, Yun Y. Current progress on pathogenicity-related transcription factors in Fusarium oxysporum. MOLECULAR PLANT PATHOLOGY 2021; 22:882-895. [PMID: 33969616 PMCID: PMC8232035 DOI: 10.1111/mpp.13068] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 05/03/2023]
Abstract
Fusarium oxysporum is a well-known soilborne plant pathogen that causes severe vascular wilt in economically important crops worldwide. During the infection process, F. oxysporum not only secretes various virulence factors, such as cell wall-degrading enzymes (CWDEs), effectors, and mycotoxins, that potentially play important roles in fungal pathogenicity but it must also respond to extrinsic abiotic stresses from the environment and the host. Over 700 transcription factors (TFs) have been predicted in the genome of F. oxysporum, but only 26 TFs have been functionally characterized in various formae speciales of F. oxysporum. Among these TFs, a total of 23 belonging to 10 families are required for pathogenesis through various mechanisms and pathways, and the zinc finger TF family is the largest family among these 10 families, which consists of 15 TFs that have been functionally characterized in F. oxysporum. In this review, we report current research progress on the 26 functionally analysed TFs in F. oxysporum and sort them into four groups based on their roles in F. oxysporum pathogenicity. Furthermore, we summarize and compare the biofunctions, involved pathways, putative targets, and homologs of these TFs and analyse the relationships among them. This review provides a systematic analysis of the regulation of virulence-related genes and facilitates further mechanistic analysis of TFs important in F. oxysporum virulence.
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Affiliation(s)
- Qussai Zuriegat
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Life SciencesFujian Agriculture and Forestry UniversityFuzhouChina
| | - Yuru Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Life SciencesFujian Agriculture and Forestry UniversityFuzhouChina
- Fujian Institute for Food and Drug Quality ControlFuzhouChina
| | - Hong Liu
- College of Resources and EnvironmentFujian Agriculture and Forestry UniversityFuzhouChina
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Life SciencesFujian Agriculture and Forestry UniversityFuzhouChina
- Institute of OceanographyMinjiang UniversityFuzhouChina
| | - Yingzi Yun
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Life SciencesFujian Agriculture and Forestry UniversityFuzhouChina
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17
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Liang X, Yao L, Hao X, Li B, Kong Y, Lin Y, Cao M, Dong Q, Zhang R, Rollins JA, Sun G. Molecular Dissection of Perithecial Mating Line Development in Colletotrichum fructicola, a Species with a Nontypical Mating System Featuring Plus-to-Minus Switch and Plus-Minus-Mediated Sexual Enhancement. Appl Environ Microbiol 2021; 87:e0047421. [PMID: 33863706 PMCID: PMC8284469 DOI: 10.1128/aem.00474-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/06/2021] [Indexed: 01/27/2023] Open
Abstract
The genetic regulation of Colletotrichum (Glomerella) sexual reproduction does not strictly adhere to the Ascomycota paradigm and remains poorly understood. Morphologically different but sexually compatible strain types, termed plus and minus, have been recognized, but the biological and molecular distinctions between these strain types remain elusive. In this study, we characterized the sexual behaviors of a pair of plus and minus strains of C. fructicola with the aid of live-cell nucleus-localized fluorescent protein labeling, gene expression, and gene mutation analyses. We confirmed a genetically stable plus-to-minus switching phenomenon and demonstrated the presence of both cross-fertilized and self-fertilized perithecia within the mating line (perithecia cluster at the line of colony contact) between plus and minus strains. We demonstrated that pheromone signaling genes (a-factor-like and α-factor-like pheromones and their corresponding GPCR receptors) were differently expressed between vegetative hyphae of the two strains. Moreover, deletion of pmk1 (a FUS/KSS1 mitogen-activate protein kinase) in the minus strain severely limited mating line formation, whereas deletion of a GPCR (FGSG_05239 homolog) and two histone modification factors (hos2, snt2) in the minus strain did not affect mating line development but altered the ratio between cross-fertilization and self-fertilization within the mating line. We propose a model in which mating line formation in C. fructicola involves enhanced protoperithecium differentiation and enhanced perithecium maturation of the minus strain mediated by both cross-fertilization and diffusive effectors. This study provides insights into mechanisms underlying the mysterious phenomenon of plus-minus-mediated sexual enhancement being unique to Colletotrichum fungi. IMPORTANCE Plus-minus regulation of Colletotrichum sexual differentiation was reported in the early 1900s. Both plus and minus strains produce fertile perithecia in a homothallic but inefficient manner. However, when the two strain types encounter each other, efficient differentiation of fertile perithecia is triggered. The plus strain, by itself, can also generate minus ascospore progeny at high frequency. This nontypical mating system facilitates sexual reproduction and is Colletotrichum specific; the underlying molecular mechanisms, however, remain elusive. The current study revisits this longstanding mystery using C. fructicola as an experimental system. The presence of both cross-fertilized and self-fertilized perithecia within the mating line was directly evidenced by live-cell imaging with fluorescent markers. Based on further gene expression and gene mutation analysis, a model explaining mating line development (plus-minus-mediated sexual enhancement) is proposed. Data reported here have the potential to allow us to better understand Colletotrichum mating and filamentous ascomycete sexual regulation.
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Affiliation(s)
- Xiaofei Liang
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Liqiang Yao
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Xiaojuan Hao
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Bingxuan Li
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Yuanyuan Kong
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Yuyi Lin
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Mengyu Cao
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Qiuyue Dong
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Rong Zhang
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Jeffrey A. Rollins
- Department of Plant Pathology, University of Florida, Gainesville, Florida, USA
| | - Guangyu Sun
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
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18
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Starke J, Harting R, Maurus I, Leonard M, Bremenkamp R, Heimel K, Kronstad JW, Braus GH. Unfolded Protein Response and Scaffold Independent Pheromone MAP Kinase Signaling Control Verticillium dahliae Growth, Development, and Plant Pathogenesis. J Fungi (Basel) 2021; 7:jof7040305. [PMID: 33921172 PMCID: PMC8071499 DOI: 10.3390/jof7040305] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/12/2021] [Accepted: 04/12/2021] [Indexed: 12/13/2022] Open
Abstract
Differentiation, growth, and virulence of the vascular plant pathogen Verticillium dahliae depend on a network of interconnected cellular signaling cascades. The transcription factor Hac1 of the endoplasmic reticulum-associated unfolded protein response (UPR) is required for initial root colonization, fungal growth, and vascular propagation by conidiation. Hac1 is essential for the formation of microsclerotia as long-time survival resting structures in the field. Single endoplasmic reticulum-associated enzymes for linoleic acid production as precursors for oxylipin signal molecules support fungal growth but not pathogenicity. Microsclerotia development, growth, and virulence further require the pheromone response mitogen-activated protein kinase (MAPK) pathway, but without the Ham5 scaffold function. The MAPK phosphatase Rok1 limits resting structure development of V.dahliae, but promotes growth, conidiation, and virulence. The interplay between UPR and MAPK signaling cascades includes several potential targets for fungal growth control for supporting disease management of the vascular pathogen V.dahliae.
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Affiliation(s)
- Jessica Starke
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, 37077 Göttingen, Germany; (J.S.); (R.H.); (I.M.); (M.L.); (R.B.); (K.H.)
| | - Rebekka Harting
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, 37077 Göttingen, Germany; (J.S.); (R.H.); (I.M.); (M.L.); (R.B.); (K.H.)
| | - Isabel Maurus
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, 37077 Göttingen, Germany; (J.S.); (R.H.); (I.M.); (M.L.); (R.B.); (K.H.)
| | - Miriam Leonard
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, 37077 Göttingen, Germany; (J.S.); (R.H.); (I.M.); (M.L.); (R.B.); (K.H.)
| | - Rica Bremenkamp
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, 37077 Göttingen, Germany; (J.S.); (R.H.); (I.M.); (M.L.); (R.B.); (K.H.)
| | - Kai Heimel
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, 37077 Göttingen, Germany; (J.S.); (R.H.); (I.M.); (M.L.); (R.B.); (K.H.)
| | - James W. Kronstad
- Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada;
| | - Gerhard H. Braus
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, 37077 Göttingen, Germany; (J.S.); (R.H.); (I.M.); (M.L.); (R.B.); (K.H.)
- Correspondence: ; Tel.: +49-(0)551-39-33771
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19
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Transcription Factor CfSte12 of Colletotrichum fructicola Is a Key Regulator of Early Apple Glomerella Leaf Spot Pathogenesis. Appl Environ Microbiol 2020; 87:AEM.02212-20. [PMID: 33067192 DOI: 10.1128/aem.02212-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 10/13/2020] [Indexed: 02/07/2023] Open
Abstract
Glomerella leaf spot (GLS), caused by Colletotrichum fructicola, is a rapidly emerging disease leading to defoliation, fruit spot, and storage fruit rot on apple in China. Little is known about the mechanisms of GLS pathogenesis. Early transcriptome analysis revealed that expression of the zinc finger transcription factor Ste12 gene in C. fructicola (CfSte12) was upregulated in appressoria and leaf infection. To investigate functions of CfSte12 during pathogenesis, we constructed gene deletion mutants (ΔCfSte12) by homologous recombination. Phenotypic analysis revealed that CfSte12 was involved in pathogenesis of nonwounded apple fruit and leaf, as well as wounded apple fruit. Subsequent histological studies revealed that loss of pathogenicity by ΔCfSte12 on apple leaf was expressed as defects of conidium germination, appressorium development, and appressorium-mediated penetration. Further RNA sequencing-based transcriptome comparison revealed that CfSte12 modulates the expression of genes related to appressorium function (e.g., genes for the tetraspanin PLS1, Gas1-like proteins, cutinases, and melanin biosynthesis) and candidate effectors likely involved in plant interaction. In sum, our results demonstrated that CfSte12 is a key regulator of early apple GLS pathogenesis in C. fructicola In addition, CfSte12 is also needed for sexual development of perithecia and ascospores.IMPORTANCE Glomerella leaf spot (GLS) is an emerging fungal disease of apple that causes huge economic losses in Asia, North America, and South America. The damage inflicted by GLS manifests in rapid necrosis of leaves, severe defoliation, and necrotic spot on the fruit surface. However, few studies have addressed mechanisms of GLS pathogenesis. In this study, we identified and characterized a key pathogenicity-related transcription factor, CfSte12, of Colletotrichum fructicola that contributes to GLS pathogenesis. We provide evidence that the CfSte12 protein regulates many important pathogenic processes of GLS, including conidium germination, appressorium formation, appressorium-mediated penetration, and colonization. CfSte12 also impacts development of structures needed for sexual reproduction which are vital for the GLS disease cycle. These results reveal a key pathogenicity-related transcription factor, CfSte12, in C. fructicola that causes GLS.
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20
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Katayama T, Bayram Ö, Mo T, Karahoda B, Valerius O, Takemoto D, Braus GH, Kitamoto K, Maruyama JI. Novel Fus3- and Ste12-interacting protein FsiA activates cell fusion-related genes in both Ste12-dependent and -independent manners in Ascomycete filamentous fungi. Mol Microbiol 2020; 115:723-738. [PMID: 33155715 DOI: 10.1111/mmi.14639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 10/28/2020] [Accepted: 11/02/2020] [Indexed: 01/01/2023]
Abstract
Filamentous fungal cells, unlike yeasts, fuse during vegetative growth. The orthologs of mitogen-activated protein (MAP) kinase Fus3 and transcription factor Ste12 are commonly involved in the regulation of cell fusion. However, the specific regulatory mechanisms underlying cell fusion in filamentous fungi have not been revealed. In the present study, we identified the novel protein FsiA as an AoFus3- and AoSte12-interacting protein in the filamentous fungus Aspergillus oryzae. The expression of AonosA and cell fusion-related genes decreased upon fsiA deletion and increased with fsiA overexpression, indicating that FsiA is a positive regulator of cell fusion. In addition, the induction of cell fusion-related genes by fsiA overexpression was also observed in the Aoste12 deletion mutant, indicating that FsiA can induce the cell fusion-related genes in an AoSte12-independent manner. Surprisingly, the fsiA and Aoste12 double deletion mutant exhibited higher cell fusion efficiency and increased mRNA levels of the cell fusion-related genes as compared to the fsiA single deletion mutant, which revealed that AoSte12 represses the cell fusion-related genes in the fsiA deletion mutant. Taken together, our data demonstrate that FsiA activates the cell fusion-related genes by suppressing the negative function of AoSte12 as well as by an AoSte12-independent mechanism.
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Affiliation(s)
- Takuya Katayama
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
| | - Özgür Bayram
- Biology Department, Maynooth University, Maynooth, Ireland
| | - Taoning Mo
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan
| | - Betim Karahoda
- Biology Department, Maynooth University, Maynooth, Ireland
| | - Oliver Valerius
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, and Göttingen Center for Molecular Biosciences (GZMB), Georg-August University, Göttingen, Germany
| | - Daigo Takemoto
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Gerhard H Braus
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, and Göttingen Center for Molecular Biosciences (GZMB), Georg-August University, Göttingen, Germany
| | - Katsuhiko Kitamoto
- Pharmaceutical Medical Business Sciences, Nihon Pharmaceutical University, Tokyo, Japan
| | - Jun-Ichi Maruyama
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
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21
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Carrillo AJ, Cabrera IE, Spasojevic MJ, Schacht P, Stajich JE, Borkovich KA. Clustering analysis of large-scale phenotypic data in the model filamentous fungus Neurospora crassa. BMC Genomics 2020; 21:755. [PMID: 33138786 PMCID: PMC7607824 DOI: 10.1186/s12864-020-07131-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 10/09/2020] [Indexed: 11/28/2022] Open
Abstract
Background With 9730 protein-coding genes and a nearly complete gene knockout strain collection, Neurospora crassa is a major model organism for filamentous fungi. Despite this abundance of information, the phenotypes of these gene knockout mutants have not been categorized to determine whether there are broad correlations between phenotype and any genetic features. Results Here, we analyze data for 10 different growth or developmental phenotypes that have been obtained for 1168 N. crassa knockout mutants. Of these mutants, 265 (23%) are in the normal range, while 903 (77%) possess at least one mutant phenotype. With the exception of unclassified functions, the distribution of functional categories for genes in the mutant dataset mirrors that of the N. crassa genome. In contrast, most genes do not possess a yeast ortholog, suggesting that our analysis will reveal functions that are not conserved in Saccharomyces cerevisiae. To leverage the phenotypic data to identify pathways, we used weighted Partitioning Around Medoids (PAM) approach with 40 clusters. We found that genes encoding metabolic, transmembrane and protein phosphorylation-related genes are concentrated in subsets of clusters. Results from K-Means clustering of transcriptomic datasets showed that most phenotypic clusters contain multiple expression profiles, suggesting that co-expression is not generally observed for genes with shared phenotypes. Analysis of yeast orthologs of genes that co-clustered in MAPK signaling cascades revealed potential networks of interacting proteins in N. crassa. Conclusions Our results demonstrate that clustering analysis of phenotypes is a promising tool for generating new hypotheses regarding involvement of genes in cellular pathways in N. crassa. Furthermore, information about gene clusters identified in N. crassa should be applicable to other filamentous fungi, including saprobes and pathogens.
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Affiliation(s)
- Alexander J Carrillo
- Department of Microbiology and Plant Pathology, University of California, 900 University Avenue, Riverside, CA, 92521, USA
| | - Ilva E Cabrera
- Department of Microbiology and Plant Pathology, University of California, 900 University Avenue, Riverside, CA, 92521, USA
| | - Marko J Spasojevic
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, California, 92521, USA
| | - Patrick Schacht
- Department of Microbiology and Plant Pathology, University of California, 900 University Avenue, Riverside, CA, 92521, USA
| | - Jason E Stajich
- Department of Microbiology and Plant Pathology, University of California, 900 University Avenue, Riverside, CA, 92521, USA
| | - Katherine A Borkovich
- Department of Microbiology and Plant Pathology, University of California, 900 University Avenue, Riverside, CA, 92521, USA.
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22
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Frawley D, Bayram Ö. The pheromone response module, a mitogen-activated protein kinase pathway implicated in the regulation of fungal development, secondary metabolism and pathogenicity. Fungal Genet Biol 2020; 144:103469. [PMID: 32950720 DOI: 10.1016/j.fgb.2020.103469] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/05/2020] [Accepted: 08/10/2020] [Indexed: 12/15/2022]
Abstract
Mitogen-activated protein kinase (MAPK) pathways are highly conserved from yeast to human and are required for the regulation of a multitude of biological processes in eukaryotes. A pentameric MAPK pathway known as the Fus3 pheromone module was initially characterised in Saccharomyces cerevisiae and was shown to regulate cell fusion and sexual development. Individual orthologous pheromone module genes have since been found to be highly conserved in fungal genomes and have been shown to regulate a diverse array of cellular responses, such as cell growth, asexual and sexual development, secondary metabolite production and pathogenicity. However, information regarding the assembly and structure of orthologous pheromone modules, as well as the mechanisms of signalling and their biological significance is limited, specifically in filamentous fungal species. Recent studies have provided insight on the utilization of the pheromone module as a central signalling hub for the co-ordinated regulation of fungal development and secondary metabolite production. Various proteins of this pathway are also known to regulate reproduction and virulence in a range of plant pathogenic fungi. In this review, we discuss recent findings that help elucidate the structure of the pheromone module pathway in a myriad of fungal species and its implications in the control of fungal growth, development, secondary metabolism and pathogenicity.
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Affiliation(s)
- Dean Frawley
- Biology Department, Callan Building, Maynooth University, Maynooth, Co. Kildare, Ireland.
| | - Özgür Bayram
- Biology Department, Callan Building, Maynooth University, Maynooth, Co. Kildare, Ireland.
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23
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Tanaka A, Kamiya S, Ozaki Y, Kameoka S, Kayano Y, Saikia S, Akano F, Uemura A, Takagi H, Terauchi R, Maruyama J, Hammadeh HH, Fleissner A, Scott B, Takemoto D. A nuclear protein NsiA from
Epichloë festucae
interacts with a MAP kinase MpkB and regulates the expression of genes required for symbiotic infection and hyphal cell fusion. Mol Microbiol 2020; 114:626-640. [DOI: 10.1111/mmi.14568] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 06/20/2020] [Accepted: 06/29/2020] [Indexed: 12/29/2022]
Affiliation(s)
- Aiko Tanaka
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
- School of Fundamental Sciences Massey University Palmerston North New Zealand
| | - Shota Kamiya
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
| | - Yoshino Ozaki
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
| | - Shinichi Kameoka
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
| | - Yuka Kayano
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
| | - Sanjay Saikia
- School of Fundamental Sciences Massey University Palmerston North New Zealand
| | - Fumitake Akano
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
| | - Aiko Uemura
- Iwate Biotechnology Research Center Kitakami Japan
| | | | | | | | - Hamzeh Haj Hammadeh
- Institut für Genetik Technische Universität Braunschweig Braunschweig Germany
| | - André Fleissner
- Institut für Genetik Technische Universität Braunschweig Braunschweig Germany
| | - Barry Scott
- School of Fundamental Sciences Massey University Palmerston North New Zealand
| | - Daigo Takemoto
- Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan
- School of Fundamental Sciences Massey University Palmerston North New Zealand
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24
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Frawley D, Stroe MC, Oakley BR, Heinekamp T, Straßburger M, Fleming AB, Brakhage AA, Bayram Ö. The Pheromone Module SteC-MkkB-MpkB-SteD-HamE Regulates Development, Stress Responses and Secondary Metabolism in Aspergillus fumigatus. Front Microbiol 2020; 11:811. [PMID: 32457716 PMCID: PMC7223695 DOI: 10.3389/fmicb.2020.00811] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/06/2020] [Indexed: 11/13/2022] Open
Abstract
In order for eukaryotes to efficiently detect and respond to environmental stimuli, a myriad of protein signaling pathways are utilized. An example of highly conserved signaling pathways in eukaryotes are the mitogen-activated protein kinase (MAPK) pathways. In fungi, MAPK pathways have been shown to regulate a diverse array of biological processes, such as asexual and sexual development, stress responses and the production of secondary metabolites (SMs). In the model fungus Aspergillus nidulans, a MAPK pathway known as the pheromone module is utilized to regulate both development and SM production. This signaling cascade consists of the three kinases SteC, MkkB, and MpkB, as well as the SteD adaptor protein and the HamE scaffold. In this study, homologs of each of these proteins have been identified in the opportunistic human pathogen A. fumigatus. By performing epitope tagging and mass spectrometry experiments, we have shown that these proteins form a pentameric complex, similar to what is observed in A. nidulans. This complex has been shown to assemble in the cytoplasm and MpkB enters the nucleus, where it would presumably interact with various transcription factors. Pheromone module mutant strains exhibit drastic reductions in asexual sporulation, vegetative growth rate and production of SMs, such as gliotoxin. Mutants also display increased sensitivity to cell wall and oxidative stress agents. Overall, these data provide evidence of the existence of a conserved MAP kinase signaling pathway in Aspergillus species and suggest that this pathway is critical for the regulation of fungal development and secondary metabolism.
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Affiliation(s)
- Dean Frawley
- Department of Biology, Fungal Genetics and Secondary Metabolism Laboratory, Maynooth University, Maynooth, Ireland
| | - Maria C Stroe
- Department of Molecular and Applied Microbiology, Hans Knöll Institute (HKI), Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Berl R Oakley
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, United States
| | - Thorsten Heinekamp
- Department of Molecular and Applied Microbiology, Hans Knöll Institute (HKI), Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Maria Straßburger
- Transfer Group Antiinfectives, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany
| | - Alastair B Fleming
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Hans Knöll Institute (HKI), Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany.,Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Özgür Bayram
- Department of Biology, Fungal Genetics and Secondary Metabolism Laboratory, Maynooth University, Maynooth, Ireland
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25
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Frawley D, Greco C, Oakley B, Alhussain MM, Fleming AB, Keller NP, Bayram Ö. The tetrameric pheromone module SteC-MkkB-MpkB-SteD regulates asexual sporulation, sclerotia formation and aflatoxin production in Aspergillus flavus. Cell Microbiol 2020; 22:e13192. [PMID: 32068947 PMCID: PMC7202998 DOI: 10.1111/cmi.13192] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/07/2020] [Accepted: 01/26/2020] [Indexed: 11/29/2022]
Abstract
For eukaryotes like fungi to regulate biological responses to environmental stimuli, various signalling cascades are utilized, like the highly conserved mitogen‐activated protein kinase (MAPK) pathways. In the model fungus Aspergillus nidulans, a MAPK pathway known as the pheromone module regulates development and the production of secondary metabolites (SMs). This pathway consists five proteins, the three kinases SteC, MkkB and MpkB, the adaptor SteD and the scaffold HamE. In this study, homologs of these five pheromone module proteins have been identified in the plant and human pathogenic fungus Aspergillus flavus. We have shown that a tetrameric complex consisting of the three kinases and the SteD adaptor is assembled in this species. It was observed that this complex assembles in the cytoplasm and that MpkB translocates into the nucleus. Deletion of steC, mkkB, mpkB or steD results in abolishment of both asexual sporulation and sclerotia production. This complex is required for the positive regulation of aflatoxin production and negative regulation of various SMs, including leporin B and cyclopiazonic acid (CPA), likely via MpkB interactions in the nucleus. These data highlight the conservation of the pheromone module in Aspergillus species, signifying the importance of this pathway in regulating fungal development and secondary metabolism.
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Affiliation(s)
- Dean Frawley
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Claudio Greco
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Berl Oakley
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
| | - Mohamed M Alhussain
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
| | - Alastair B Fleming
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Özgür Bayram
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
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26
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Ma H, Zhang B, Gai Y, Sun X, Chung KR, Li H. Cell-Wall-Degrading Enzymes Required for Virulence in the Host Selective Toxin-Producing Necrotroph Alternaria alternata of Citrus. Front Microbiol 2019; 10:2514. [PMID: 31824437 PMCID: PMC6883767 DOI: 10.3389/fmicb.2019.02514] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 10/18/2019] [Indexed: 12/12/2022] Open
Abstract
The necrotrophic fungal pathogen Alternaria alternata attacks many citrus species, causing brown spot disease. Its pathogenic capability depends primarily on the production of host-selective ACT toxin. In the current study a Ste12 transcription factor was characterized to be required for conidial formation and the production of cell-wall-degrading enzymes (CWDEs) in the tangerine pathotype of A. alternata. The Ste12 deficiency strain (ΔSte12) retained wild-type growth, ACT toxin production, and sensitivity to oxidative and osmotic stress. However, pathogenicity tests assayed on detached Dancy leaves revealed a marked reduction in virulence of ΔSte12. Transcriptome and quantitative RT-PCR analyses revealed that many genes associated with Carbohydrate-Active Enzymes (CAZymes) were downregulated in ΔSte12. Two cutinase-coding genes (AaCut3 and AaCut7) regulated by Ste12 were individually and simultaneously inactivated. The AaCut3 or AaCut7 deficiency strain unchanged in cutinase activities and incited wild-type lesions on Dancy leaves. However, the strain carrying an AaCut3 AaCut7 double mutation produced and secreted significantly fewer cutinases and incited smaller necrotic lesions than wild type. Not only is the host-selective toxin (HST) produced by A. alternata required for fungal penetration and lesion formation, but so too are CWDEs required for full virulence. Overall, this study expands our understanding of how A. alternata overcomes citrus physical barriers to carry out successful penetration and colonization.
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Affiliation(s)
- Haijie Ma
- Key Lab of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Bin Zhang
- Key Lab of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Yunpeng Gai
- Key Lab of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Xuepeng Sun
- Key Lab of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Kuang-Ren Chung
- Department of Plant Pathology, College of Agriculture and Natural Resources, National Chung-Hsing University, Taichung, Taiwan
| | - Hongye Li
- Key Lab of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Biotechnology, Zhejiang University, Hangzhou, China
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27
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Grognet P, Timpano H, Carlier F, Aït-Benkhali J, Berteaux-Lecellier V, Debuchy R, Bidard F, Malagnac F. A RID-like putative cytosine methyltransferase homologue controls sexual development in the fungus Podospora anserina. PLoS Genet 2019; 15:e1008086. [PMID: 31412020 PMCID: PMC6709928 DOI: 10.1371/journal.pgen.1008086] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 08/26/2019] [Accepted: 07/15/2019] [Indexed: 11/18/2022] Open
Abstract
DNA methyltransferases are ubiquitous enzymes conserved in bacteria, plants and opisthokonta. These enzymes, which methylate cytosines, are involved in numerous biological processes, notably development. In mammals and higher plants, methylation patterns established and maintained by the cytosine DNA methyltransferases (DMTs) are essential to zygotic development. In fungi, some members of an extensively conserved fungal-specific DNA methyltransferase class are both mediators of the Repeat Induced Point mutation (RIP) genome defense system and key players of sexual reproduction. Yet, no DNA methyltransferase activity of these purified RID (RIP deficient) proteins could be detected in vitro. These observations led us to explore how RID-like DNA methyltransferase encoding genes would play a role during sexual development of fungi showing very little genomic DNA methylation, if any. To do so, we used the model ascomycete fungus Podospora anserina. We identified the PaRid gene, encoding a RID-like DNA methyltransferase and constructed knocked-out ΔPaRid defective mutants. Crosses involving P. anserina ΔPaRid mutants are sterile. Our results show that, although gametes are readily formed and fertilization occurs in a ΔPaRid background, sexual development is blocked just before the individualization of the dikaryotic cells leading to meiocytes. Complementation of ΔPaRid mutants with ectopic alleles of PaRid, including GFP-tagged, point-mutated and chimeric alleles, demonstrated that the catalytic motif of the putative PaRid methyltransferase is essential to ensure proper sexual development and that the expression of PaRid is spatially and temporally restricted. A transcriptomic analysis performed on mutant crosses revealed an overlap of the PaRid-controlled genetic network with the well-known mating-types gene developmental pathway common to an important group of fungi, the Pezizomycotina.
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Affiliation(s)
- Pierre Grognet
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris‐Saclay, France
| | - Hélène Timpano
- Université Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France, CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
| | - Florian Carlier
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris‐Saclay, France
| | - Jinane Aït-Benkhali
- Université Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France, CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
| | | | - Robert Debuchy
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris‐Saclay, France
| | - Frédérique Bidard
- Université Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France, CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
| | - Fabienne Malagnac
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris‐Saclay, France
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28
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Hatamoto M, Aizawa R, Kobayashi Y, Fujimura M. A novel fungicide aminopyrifen inhibits GWT-1 protein in glycosylphosphatidylinositol-anchor biosynthesis in Neurospora crassa. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2019; 156:1-8. [PMID: 31027568 DOI: 10.1016/j.pestbp.2019.02.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 02/19/2019] [Accepted: 02/19/2019] [Indexed: 06/09/2023]
Abstract
Aminopyrifen, 4-phenoxybenzyl 2-amino-6-methylnicotinate, strongly inhibited the mycelial growth of a wild-type Neurospora crassa strain on Vogel's minimal medium containing 1.2% sucrose, with a 0.001 mg/L concentration required for 50% growth inhibition. Similar to micafungin, an inhibitor of beta-1, 3-glucan synthetase, aminopyrifen further inhibited the growth of N. crassa deletion mutants of MAP kinase cascade genes, such as mak-1 and mak-2, than the wild-type strain, suggesting that aminopyrifen perturbs cell wall-related processes. Furthermore, we found that three chitin synthase gene mutants (chs-1, chs-5, and chs-7) were highly sensitive to both chemicals; however, aminopyrifen, but not micafungin, induced a swollen germ tube from the conidia of chs-5 and chs-7 mutants on Vogel's medium containing 1.2% sucrose. To elucidate the target protein of aminopyrifen, we isolated mutants resistant to aminopyrifen after UV treatment of conidia of the wild-type strain or the chs-5 strain. The resistance mutations were localized to the gwt-1 gene that encodes an acyltransferase, GWT-1, which participates in the biosynthesis of the glycosylphosphatidylinositol (GPI) precursor, and were found to result in S180F and V178A alterations in the protein. These results strongly suggest that aminopyrifen works as an inhibitor targeting GWT-1, a protein involved in GPI-anchor biosynthesis.
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Affiliation(s)
- Masahiro Hatamoto
- Biological Section Research Department, Agro-Kanesho Co., Ltd., 9511-4 Yuki, Yuki-City, Ibaraki 307-0001, Japan
| | - Ryo Aizawa
- Chemical Synthesis Section Research Department, Agro-Kanesho Co., Ltd., 852, Shimoyasumatsu, Tokorozawa-City, Saitama 359-0024, Japan
| | - Yuta Kobayashi
- Faculty of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura-machi, Ora-gun, Gunma 374-0193, Japan
| | - Makoto Fujimura
- Faculty of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura-machi, Ora-gun, Gunma 374-0193, Japan.
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29
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Fischer MS, Glass NL. Communicate and Fuse: How Filamentous Fungi Establish and Maintain an Interconnected Mycelial Network. Front Microbiol 2019; 10:619. [PMID: 31001214 PMCID: PMC6455062 DOI: 10.3389/fmicb.2019.00619] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 03/12/2019] [Indexed: 12/22/2022] Open
Abstract
Cell-to-cell communication and cell fusion are fundamental biological processes across the tree of life. Survival is often dependent upon being able to identify nearby individuals and respond appropriately. Communication between genetically different individuals allows for the identification of potential mating partners, symbionts, prey, or predators. In contrast, communication between genetically similar (or identical) individuals is important for mediating the development of multicellular organisms or for coordinating density-dependent behaviors (i.e., quorum sensing). This review describes the molecular and genetic mechanisms that mediate cell-to-cell communication and cell fusion between cells of Ascomycete filamentous fungi, with a focus on Neurospora crassa. Filamentous fungi exist as a multicellular, multinuclear network of hyphae, and communication-mediated cell fusion is an important aspect of colony development at each stage of the life cycle. Asexual spore germination occurs in a density-dependent manner. Germinated spores (germlings) avoid cells that are genetically different at specific loci, while chemotropically engaging with cells that share identity at these recognition loci. Germlings with genetic identity at recognition loci undergo cell fusion when in close proximity, a fitness attribute that contributes to more rapid colony establishment. Communication and cell fusion also occur between hyphae in a colony, which are important for reinforcing colony architecture and supporting the development of complex structures such as aerial hyphae and sexual reproductive structures. Over 70 genes have been identified in filamentous fungi (primarily N. crassa) that are involved in kind recognition, chemotropic interactions, and cell fusion. While the hypothetical signal(s) and receptor(s) remain to be described, a dynamic molecular signaling network that regulates cell-cell interactions has been revealed, including two conserved MAP-Kinase cascades, a conserved STRIPAK complex, transcription factors, a NOX complex involved in the generation of reactive oxygen species, cell-integrity sensors, actin, components of the secretory pathway, and several other proteins. Together these pathways facilitate the integration of extracellular signals, direct polarized growth, and initiate a transcriptional program that reinforces signaling and prepares cells for downstream processes, such as membrane merger, cell fusion and adaptation to heterokaryon formation.
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Affiliation(s)
- Monika S. Fischer
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley CA, United States
| | - N. Louise Glass
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley CA, United States
- Environmental Genomics and Systems Biology Division, The Lawrence Berkeley National Laboratory, Berkeley, CA, United States
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30
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Metabolism and Development during Conidial Germination in Response to a Carbon-Nitrogen-Rich Synthetic or a Natural Source of Nutrition in Neurospora crassa. mBio 2019; 10:mBio.00192-19. [PMID: 30914504 PMCID: PMC6437048 DOI: 10.1128/mbio.00192-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Fungal spores germinate and undergo vegetative growth, leading to either asexual or sexual reproductive dispersal. Previous research has indicated that among developmental regulatory genes, expression is conserved across nutritional environments, whereas pathways for carbon and nitrogen metabolism appear highly responsive-perhaps to accommodate differential nutritive processing. To comprehensively investigate conidial germination and the adaptive life history decision-making underlying these two modes of reproduction, we profiled transcription of Neurospora crassa germinating on two media: synthetic Bird medium, designed to promote asexual reproduction; and a natural maple sap medium, on which both asexual reproduction and sexual reproduction manifest. A later start to germination but faster development was observed on synthetic medium. Metabolic genes exhibited altered expression in response to nutrients-at least 34% of the genes in the genome were significantly downregulated during the first two stages of conidial germination on synthetic medium. Knockouts of genes exhibiting differential expression across development altered germination and growth rates, as well as in one case causing abnormal germination. A consensus Bayesian network of these genes indicated especially tight integration of environmental sensing, asexual and sexual development, and nitrogen metabolism on a natural medium, suggesting that in natural environments, a more dynamic and tentative balance of asexual and sexual development may be typical of N. crassa colonies.IMPORTANCE One of the most remarkable successes of life is its ability to flourish in response to temporally and spatially varying environments. Fungi occupy diverse ecosystems, and their sensitivity to these environmental changes often drives major fungal life history decisions, including the major switch from vegetative growth to asexual or sexual reproduction. Spore germination comprises the first and simplest stage of vegetative growth. We examined the dependence of this early life history on the nutritional environment using genome-wide transcriptomics. We demonstrated that for developmental regulatory genes, expression was generally conserved across nutritional environments, whereas metabolic gene expression was highly labile. The level of activation of developmental genes did depend on current nutrient conditions, as did the modularity of metabolic and developmental response network interactions. This knowledge is critical to the development of future technologies that could manipulate fungal growth for medical, agricultural, or industrial purposes.
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31
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Frawley D, Karahoda B, Sarikaya Bayram Ö, Bayram Ö. The HamE scaffold positively regulates MpkB phosphorylation to promote development and secondary metabolism in Aspergillus nidulans. Sci Rep 2018; 8:16588. [PMID: 30410052 PMCID: PMC6224500 DOI: 10.1038/s41598-018-34895-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 10/24/2018] [Indexed: 11/09/2022] Open
Abstract
Mitogen-activated protein kinase (MAPK) pathways are conserved signalling cascades in eukaryotes which regulate a myriad of processes in fungi from sexual reproduction to stress responses. These pathways rely on recruitment of three kinases on a scaffold protein to facilitate efficient kinase phosphorylation and subsequent downstream signalling to the nucleus. The model filamentous fungus Aspergillus nidulans utilises a MAPK pathway termed the pheromone module to regulate both development and secondary metabolism. This complex consists of the MAP3K (SteC), MAP2K (MkkB), MAPK (MpkB) and adaptor protein SteD. To date, there has been no scaffold protein identified for this MAPK pathway. In this study, we characterised a protein termed HamE, which we propose as a scaffold that regulates kinase phosphorylation and signalling in the pheromone module. Mass spectrometry analysis and BIFC experiments revealed that HamE physically interacts with both MkkB and MpkB and transiently interacts with SteC. Deletion of hamE or any of the pheromone module kinases results in reduced sporulation and complete abolishment of cleistothecia production. Mutants also exhibited reductions in expression of secondary metabolite gene clusters, including the velvet complex and sterigmatocystin genes. HamE acts as a positive regulator of MpkB phosphorylation, allowing for HamE to subsequently regulate development and secondary metabolism.
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Affiliation(s)
- Dean Frawley
- Biology Department, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Betim Karahoda
- Biology Department, Maynooth University, Maynooth, Co. Kildare, Ireland
| | | | - Özgür Bayram
- Biology Department, Maynooth University, Maynooth, Co. Kildare, Ireland. .,Maynooth University Human Health Research Institute, Kildare, Ireland.
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Xu T, Li J, Yu B, Liu L, Zhang X, Liu J, Pan H, Zhang Y. Transcription Factor SsSte12 Was Involved in Mycelium Growth and Development in Sclerotinia sclerotiorum. Front Microbiol 2018; 9:2476. [PMID: 30386319 PMCID: PMC6200020 DOI: 10.3389/fmicb.2018.02476] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 09/28/2018] [Indexed: 01/08/2023] Open
Abstract
Sclerotinia sclerotiorum is a challenging agricultural pathogen for management, causing large global economic losses annually. The sclerotia and infection cushions are critical for its long-term survival and successful penetration on a wide spectrum of hosts. The mitogen-activated protein kinase (MAPK) cascades serve as central signaling complexes that are involved in various aspects of sclerotia development and infection. In this study, the putative downstream transcription factor of MAPK pathway, SsSte12, was analyzed in S. sclerotiorum. Silencing SsSte12 in S. sclerotiorum resulted in phenotypes of delayed vegetative growth, reduced size of sclerotia, and fewer appressoria formation. Consequently, the SsSte12 RNAi mutants showed attenuated pathogenicity on the host plants due to the defect compound appressorium. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation assays demonstrated that the SsSte12 interacts with SsMcm1. However, the SsMcm1 expression is independent of the regulation of SsSte12 as revealed by qRT-PCR analysis in SsSte12 RNAi mutants. Together with high accumulation of SsSte12 transcripts in the early development of S. sclerotiorum, our results demonstrated that SsSte12 function was essential in the vegetative mycelial growth, sclerotia development, appressoria formation and penetration-dependent pathogenicity. Moreover, the SsSte12-SsMcm1 interaction might play a critical role in the regulation of the genes encoding these traits in S. sclerotiorum.
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Affiliation(s)
- Tingtao Xu
- College of Plant Sciences, Jilin University, Changchun, China
| | - Jingtao Li
- College of Plant Sciences, Jilin University, Changchun, China
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Baodong Yu
- Department of Emergency of Xinmin, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Ling Liu
- College of Plant Sciences, Jilin University, Changchun, China
| | - Xianghui Zhang
- College of Plant Sciences, Jilin University, Changchun, China
| | - Jinliang Liu
- College of Plant Sciences, Jilin University, Changchun, China
| | - Hongyu Pan
- College of Plant Sciences, Jilin University, Changchun, China
| | - Yanhua Zhang
- College of Plant Sciences, Jilin University, Changchun, China
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Serrano A, Illgen J, Brandt U, Thieme N, Letz A, Lichius A, Read ND, Fleißner A. Spatio-temporal MAPK dynamics mediate cell behavior coordination during fungal somatic cell fusion. J Cell Sci 2018; 131:jcs.213462. [PMID: 29592970 DOI: 10.1242/jcs.213462] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 03/20/2018] [Indexed: 01/17/2023] Open
Abstract
Mitogen-activated protein kinases (MAPKs) are conserved regulators of proliferation, differentiation and adaptation in eukaryotic cells. Their activity often involves changes in their subcellular localization, indicating an important role for these spatio-temporal dynamics in signal transmission. A striking model illustrating these dynamics is somatic cell fusion in Neurospora crassa Germinating spores of this fungus rapidly alternate between signal sending and receiving, thereby establishing a cell-cell dialog, which involves the alternating membrane recruitment of the MAPK MAK-2 in both fusion partners. Here, we show that the dynamic translocation of MAK-2 is essential for coordinating the behavior of the fusion partners before physical contact. The activation and function of the kinase strongly correlate with its subcellular localization, indicating a crucial contribution of the MAPK dynamics in establishing regulatory feedback loops, which establish the oscillatory signaling mode. In addition, we provide evidence that MAK-2 not only contributes to cell-cell communication, but also mediates cell-cell fusion. The MAK-2 dynamics significantly differ between these two processes, suggesting a role for the MAPK in switching of the cellular program between communication and fusion.
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Affiliation(s)
- Antonio Serrano
- Institut für Genetik, Technische Universität Braunschweig, Spielmannstraße 7, 38106 Braunschweig, Germany
| | - Julia Illgen
- Institut für Genetik, Technische Universität Braunschweig, Spielmannstraße 7, 38106 Braunschweig, Germany
| | - Ulrike Brandt
- Institut für Genetik, Technische Universität Braunschweig, Spielmannstraße 7, 38106 Braunschweig, Germany
| | - Nils Thieme
- Institut für Genetik, Technische Universität Braunschweig, Spielmannstraße 7, 38106 Braunschweig, Germany
| | - Anja Letz
- Institut für Genetik, Technische Universität Braunschweig, Spielmannstraße 7, 38106 Braunschweig, Germany
| | - Alexander Lichius
- Institute of Microbiology, University of Innsbruck, 6020 Innsbruck, Austria
| | - Nick D Read
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, University of Manchester, Manchester M13 9NT, UK
| | - André Fleißner
- Institut für Genetik, Technische Universität Braunschweig, Spielmannstraße 7, 38106 Braunschweig, Germany
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Regulation of Cell-to-Cell Communication and Cell Wall Integrity by a Network of MAP Kinase Pathways and Transcription Factors in Neurospora crassa. Genetics 2018; 209:489-506. [PMID: 29678830 DOI: 10.1534/genetics.118.300904] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 04/18/2018] [Indexed: 11/18/2022] Open
Abstract
Maintenance of cell integrity and cell-to-cell communication are fundamental biological processes. Filamentous fungi, such as Neurospora crassa, depend on communication to locate compatible cells, coordinate cell fusion, and establish a robust hyphal network. Two MAP kinase (MAPK) pathways are essential for communication and cell fusion in N. crassa: the cell wall integrity/MAK-1 pathway and the MAK-2 (signal response) pathway. Previous studies have demonstrated several points of cross-talk between the MAK-1 and MAK-2 pathways, which is likely necessary for coordinating chemotropic growth toward an extracellular signal, and then mediating cell fusion. Canonical MAPK pathways begin with signal reception and end with a transcriptional response. Two transcription factors, ADV-1 and PP-1, are essential for communication and cell fusion. PP-1 is the conserved target of MAK-2, but it is unclear what targets ADV-1. We did RNA sequencing on Δadv-1, Δpp-1, and wild-type cells and found that ADV-1 and PP-1 have a shared regulon including many genes required for communication, cell fusion, growth, development, and stress response. We identified ADV-1 and PP-1 binding sites across the genome by adapting the in vitro method of DNA-affinity purification sequencing for N. crassa To elucidate the regulatory network, we misexpressed each transcription factor in each upstream MAPK deletion mutant. Misexpression of adv-1 was sufficient to fully suppress the phenotype of the Δpp-1 mutant and partially suppress the phenotype of the Δmak-1 mutant. Collectively, our data demonstrate that the MAK-1/ADV-1 and MAK-2/PP-1 pathways form a tight regulatory network that maintains cell integrity and mediates communication and cell fusion.
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Zhu X, Liu W, Chu X, Sun Q, Tan C, Yang Q, Jiao M, Guo J, Kang Z. The transcription factor PstSTE12 is required for virulence of Puccinia striiformis f. sp. tritici. MOLECULAR PLANT PATHOLOGY 2018; 19:961-974. [PMID: 28710879 PMCID: PMC6638054 DOI: 10.1111/mpp.12582] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 07/11/2017] [Accepted: 07/11/2017] [Indexed: 05/21/2023]
Abstract
Puccinia striiformis f. sp. tritici (Pst) is an obligate biotrophic fungus that causes extensive damage in wheat. The pathogen is now known to be a heteroecious fungus with an intricate life cycle containing sexual and asexual stages. Orthologues of the STE12 transcription factor that regulate mating and filamentation in Saccharomyces cerevisiae, as well as virulence in other fungi, have been extensively described. Because reliable transformation and gene disruption methods are lacking for Pst, knowledge about the function of its STE12 orthologue is limited. In this study, we identified a putative orthologue of STE12 from Pst in haustoria-enriched transcripts and designated it as PstSTE12. The gene encodes a protein of 879 amino acids containing three helices in the homeodomain, conserved phenylalanine and tryptophan sites, and two C2 /H2 -Zn2+ finger domains. Real-time reverse transcription-polymerase chain reaction (RT-PCR) analyses revealed that the expression of PstSTE12 was highly induced during the early infection stages and peaked during haustorium formation and the pycniospore stage in the aecial host barberry. Subcellular localization assays indicated that PstSTE12 is localized in the nucleus and functions as a transcriptional activator. Yeast one-hybrid assays revealed that PstSTE12 exhibits transcriptional activity, and that its C-terminus is necessary for the activation of transcription. PstSTE12 complemented the mating defect in an α ste12 mutant of S. cerevisiae. In addition, it partially complemented the defects of the Magnaporthe oryzae mst12 mutant in plant infection. Knocking down PstSTE12 via host-induced gene silencing (HIGS) mediated by Barley stripe mosaic virus (BSMV) resulted in a substantial reduction in the growth and spread of hyphae in Pst and weakened the virulence of Pst on wheat. Our results suggest that PstSTE12 probably acts at an intersection participating in the invasion and mating processes of Pst, and provide new insights into the comprehension of the variation of virulence in cereal rust fungi.
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Affiliation(s)
- Xiaoguo Zhu
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant Protection, Northwest A&F UniversityYanglingShaanxi 712100China
| | - Wei Liu
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant Protection, Northwest A&F UniversityYanglingShaanxi 712100China
| | - Xiuling Chu
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant Protection, Northwest A&F UniversityYanglingShaanxi 712100China
| | - Qixiong Sun
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant Protection, Northwest A&F UniversityYanglingShaanxi 712100China
| | - Chenglong Tan
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant Protection, Northwest A&F UniversityYanglingShaanxi 712100China
| | - Qian Yang
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant Protection, Northwest A&F UniversityYanglingShaanxi 712100China
| | - Min Jiao
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant Protection, Northwest A&F UniversityYanglingShaanxi 712100China
| | - Jun Guo
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant Protection, Northwest A&F UniversityYanglingShaanxi 712100China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant Protection, Northwest A&F UniversityYanglingShaanxi 712100China
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Wei Q, Du Y, Jin K, Xia Y. The Ste12-like transcription factor MaSte12 is involved in pathogenicity by regulating the appressorium formation in the entomopathogenic fungus, Metarhizium acridum. Appl Microbiol Biotechnol 2017; 101:8571-8584. [PMID: 29079863 DOI: 10.1007/s00253-017-8569-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 09/17/2017] [Accepted: 09/26/2017] [Indexed: 12/29/2022]
Abstract
Homeodomain transcription factor Ste12 is a key target activated by the pathogenic mitogen-activated-protein kinase pathway, and the activated Ste12p protein regulates downstream gene expression levels to modulate phenotypes. However, the functions of Ste12-like genes in entomopathogenic fungi remain poorly understood and little is known about the downstream genes regulated by Ste12. In this study, we characterized the functions of a Ste12 orthologue in Metarhizium acridum, MaSte12, and identified its downstream target genes. The deletion mutant (ΔMaSte12) is defective in conidial germination but not in hyphal growth, conidiation, or stress tolerance. Bioassays showed that ΔMaSte12 had a dramatically decreased virulence in topical inoculations, but no significant difference was found in intrahemolymph injections when the penetration process was bypassed. The mature appressorium formation rate of ΔMaSte12 was less than 10% on locust wings, with the majority hyphae forming appressorium-like, curved but no swollen structures. Digital gene expression profiling revealed that some genes involved in cell wall synthesis and remodeling, appressorium development, and insect cuticle penetration were downregulated in ΔMaSte12. Thus, MaSte12 has critical roles in the pathogenicity of the entomopathogenic fungus M. acridum, and our study provides some explanations for the impairment of fungal virulence in ΔMaSte12. In addition, virulence is very important for fungal biocontrol agents to control insect pests effectively. This study demonstrated that MaSte12 is involved in fungal virulence but not conidial yield or fungal stress tolerance in M. acridum. Thus, MaSte12 and its downstream genes may be candidates for enhancing fungal virulence to improve mycoinsecticides.
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Affiliation(s)
- Qinglv Wei
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, 401331, People's Republic of China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, 401331, People's Republic of China
| | - Yanru Du
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, 401331, People's Republic of China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, 401331, People's Republic of China
| | - Kai Jin
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, 401331, People's Republic of China.
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, 401331, People's Republic of China.
| | - Yuxian Xia
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, 401331, People's Republic of China.
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, 401331, People's Republic of China.
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Abstract
Regulation of gene expression by DNA-binding transcription factors is essential for proper control of growth and development in all organisms. In this study, we annotate and characterize growth and developmental phenotypes for transcription factor genes in the model filamentous fungus Neurospora crassa. We identified 312 transcription factor genes, corresponding to 3.2% of the protein coding genes in the genome. The largest class was the fungal-specific Zn2Cys6 (C6) binuclear cluster, with 135 members, followed by the highly conserved C2H2 zinc finger group, with 61 genes. Viable knockout mutants were produced for 273 genes, and complete growth and developmental phenotypic data are available for 242 strains, with 64% possessing at least one defect. The most prominent defect observed was in growth of basal hyphae (43% of mutants analyzed), followed by asexual sporulation (38%), and the various stages of sexual development (19%). Two growth or developmental defects were observed for 21% of the mutants, while 8% were defective in all three major phenotypes tested. Analysis of available mRNA expression data for a time course of sexual development revealed mutants with sexual phenotypes that correlate with transcription factor transcript abundance in wild type. Inspection of this data also implicated cryptic roles in sexual development for several cotranscribed transcription factor genes that do not produce a phenotype when mutated.
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Vilanova L, Teixidó N, Torres R, Usall J, Viñas I, Sánchez-Torres P. Relevance of the transcription factor PdSte12 in Penicillium digitatum conidiation and virulence during citrus fruit infection. Int J Food Microbiol 2016; 235:93-102. [DOI: 10.1016/j.ijfoodmicro.2016.07.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 11/26/2022]
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Steffens EK, Becker K, Krevet S, Teichert I, Kück U. Transcription factor PRO1 targets genes encoding conserved components of fungal developmental signaling pathways. Mol Microbiol 2016; 102:792-809. [PMID: 27560538 DOI: 10.1111/mmi.13491] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2016] [Indexed: 01/05/2023]
Abstract
The filamentous fungus Sordaria macrospora is a model system to study multicellular development during fruiting body formation. Previously, we demonstrated that this major process in the sexual life cycle is controlled by the Zn(II)2 Cys6 zinc cluster transcription factor PRO1. Here, we further investigated the genome-wide regulatory network controlled by PRO1 by employing chromatin immunoprecipitation combined with next-generation sequencing (ChIP-seq) to identify binding sites for PRO1. We identified several target regions that occur in the promoter regions of genes encoding components of diverse signaling pathways. Furthermore, we identified a conserved DNA-binding motif that is bound specifically by PRO1 in vitro. In addition, PRO1 controls in vivo the expression of a DsRed reporter gene under the control of the esdC target gene promoter. Our ChIP-seq data suggest that PRO1 also controls target genes previously shown to be involved in regulating the pathways controlling cell wall integrity, NADPH oxidase and pheromone signaling. Our data point to PRO1 acting as a master regulator of genes for signaling components that comprise a developmental cascade controlling fruiting body formation.
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Affiliation(s)
- Eva Katharina Steffens
- Lehrstuhl für Allgemeine und Molekulare Botanik Ruhr-University Bochum, Universitätsstraße 150, Bochum, 44780, Germany
| | - Kordula Becker
- Lehrstuhl für Allgemeine und Molekulare Botanik Ruhr-University Bochum, Universitätsstraße 150, Bochum, 44780, Germany
| | - Sabine Krevet
- Lehrstuhl für Allgemeine und Molekulare Botanik Ruhr-University Bochum, Universitätsstraße 150, Bochum, 44780, Germany
| | - Ines Teichert
- Lehrstuhl für Allgemeine und Molekulare Botanik Ruhr-University Bochum, Universitätsstraße 150, Bochum, 44780, Germany
| | - Ulrich Kück
- Lehrstuhl für Allgemeine und Molekulare Botanik Ruhr-University Bochum, Universitätsstraße 150, Bochum, 44780, Germany
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Kamei M, Yamashita K, Takahashi M, Fukumori F, Ichiishi A, Fujimura M. Involvement of MAK-1 and MAK-2 MAP kinases in cell wall integrity in Neurospora crassa. Biosci Biotechnol Biochem 2016; 80:1843-52. [DOI: 10.1080/09168451.2016.1189321] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Abstract
Among three MAPK disruptants of Neurospora crassa, Δmak-1 was sensitive and Δmak-2 was hypersensitive to micafungin, a beta-1,3-glucan synthase inhibitor, than the wild-type or Δos-2 strains. We identified six micafungin-inducible genes that are involved in cell wall integrity (CWI) and found that MAK-1 regulated the transcription of non-anchored cell wall protein gene, ncw-1, and the beta-1,3-endoglucanase gene, bgt-2, whereas MAK-2 controlled the expression of the glycosylhydrolase-like protein gene, gh76-5, and the C4-dicarboxylate transporter gene, tdt-1. Western blotting analysis revealed that, in the wild-type strain, MAK-1 was constitutively phosphorylated from conidial germination to hyphal development. In contrast, the phosphorylation of MAK-2 was growth phase-dependent, and micafungin induced the phosphorylation of unphosphorylated MAK-2. It should be noted that the phosphorylation of MAK-1 was virtually abolished in the Δmak-2 strain, but was significantly induced by micafungin, suggesting functional cross talk between MAK-1 and MAK-2 signalling pathway in CWI.
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Affiliation(s)
- Masayuki Kamei
- Faculty of Life Sciences, Toyo University, Oura-gun, Japan
- Department of Microbiology, University of Georgia, Athens, GA, USA
| | | | | | - Fumiyasu Fukumori
- Faculty of Food and Nutritional Sciences, Toyo University, Oura-gun, Japan
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Fleißner A, Herzog S. Signal exchange and integration during self-fusion in filamentous fungi. Semin Cell Dev Biol 2016; 57:76-83. [DOI: 10.1016/j.semcdb.2016.03.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/06/2016] [Accepted: 03/22/2016] [Indexed: 11/16/2022]
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43
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Wang CL, Shim WB, Shaw BD. The Colletotrichum graminicola striatin orthologue Str1 is necessary for anastomosis and is a virulence factor. MOLECULAR PLANT PATHOLOGY 2016; 17:931-42. [PMID: 26576029 PMCID: PMC6638439 DOI: 10.1111/mpp.12339] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/19/2015] [Accepted: 10/20/2015] [Indexed: 05/24/2023]
Abstract
Striatin family proteins are key regulators in signalling pathways in fungi and animals. These scaffold proteins contain four conserved domains: a caveolin-binding domain, a coiled-coil motif and a calmodulin-binding domain at the N-terminus, and a WD-repeat domain at the C-terminus. Fungal striatin orthologues are associated with sexual development, hyphal growth and plant pathogenesis. In Fusarium verticillioides, the striatin orthologue Fsr1 promotes virulence in the maize stalk. The relationship between fungal striatins and pathogenicity remains largely unexplored. In this study, we demonstrate that the Colletotrichum graminicola striatin orthologue Str1 is required for full stalk rot and leaf blight virulence in maize. Pathogenicity assays show that the striatin mutant strain (Δstr1) produces functional appressoria, but infection and colonization are attenuated. Additional phenotypes of the Δstr1 mutant include reduced radial growth and compromised hyphal fusion. In comparison with the wild-type, Δstr1 also shows a defect in sexual development and produces fewer and shorter conidia. Together with the fact that F. verticillioides fsr1 can complement Δstr1, our results indicate that C. graminicola Str1 shares five phenotypes with striatin orthologues in other fungal species: hyphal growth, hyphal fusion, conidiation, sexual development and virulence. We propose that fungal striatins, like mammalian striatins, act as scaffolding molecules that cross-link multiple signal transduction pathways.
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Affiliation(s)
- Chih-Li Wang
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station 77843-2132, TX, USA
- Department of Plant Pathology, National Chung Hsing University, Taichung 40227, Taiwan
| | - Won-Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station 77843-2132, TX, USA
| | - Brian D Shaw
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station 77843-2132, TX, USA
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Kröber A, Etzrodt S, Bach M, Monod M, Kniemeyer O, Staib P, Brakhage AA. The transcriptional regulators SteA and StuA contribute to keratin degradation and sexual reproduction of the dermatophyte Arthroderma benhamiae. Curr Genet 2016; 63:103-116. [PMID: 27170358 DOI: 10.1007/s00294-016-0608-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/11/2016] [Accepted: 04/26/2016] [Indexed: 01/08/2023]
Abstract
Most superficial fungal infections are caused by dermatophytes, a specialized group of filamentous fungi which exclusively infect keratinized host structures such as hair, skin and nails. Since little is known about the molecular basis of pathogenicity and sexual reproduction in dermatophytes, here we functionally addressed two central transcriptional regulators, SteA and StuA. In the zoophilic species Arthroderma benhamiae a strategy for targeted genetic manipulation was recently established, and moreover, the species is teleomorphic and thus allows performing assays based on mating. By comparative genome analysis homologs of the developmental regulators SteA and StuA were identified in A. benhamiae. Knock-out mutants of the corresponding genes as well as complemented strains were generated and phenotypically characterized. In contrast to A. benhamiae wild type and complemented strains, both mutants failed to produce sexual reproductive structures in mating experiments. Analysis of growth on keratin substrates indicated that loss of steA resulted in the inability of ΔsteA mutants to produce hair perforation organs, but did not affect mycelia formation during growth on hair and nails. By contrast, ΔstuA mutants displayed a severe growth defect on these substrates, but were still able to produce hair perforations. Hence, formation of hair perforation organs and fungal growth on hair per se are differentially regulated processes. Our findings on the major role of SteA and StuA during sexual development and keratin degradation in A. benhamiae provide insights into their role in dermatophytes and further enhance our knowledge of basic biology and pathogenicity of these fungi.
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Affiliation(s)
- Antje Kröber
- Junior Research Group Fundamental Molecular Biology of Pathogenic Fungi, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany.,Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany
| | - Sandra Etzrodt
- Junior Research Group Fundamental Molecular Biology of Pathogenic Fungi, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany.,Study and Examination Office, Faculty of Biology and Pharmacy, Friedrich Schiller University, Jena, Germany
| | - Maria Bach
- Junior Research Group Fundamental Molecular Biology of Pathogenic Fungi, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany.,Zentrum für Diagnostik GmbH am Klinikum Chemnitz, Chemnitz, Germany
| | - Michel Monod
- Department of Dermatology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Olaf Kniemeyer
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany.,Department Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Peter Staib
- Junior Research Group Fundamental Molecular Biology of Pathogenic Fungi, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany. .,Department of Research and Development, Kneipp GmbH, Würzburg, Germany.
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany. .,Department Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University, Jena, Germany.
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Assessing the relevance of light for fungi: Implications and insights into the network of signal transmission. ADVANCES IN APPLIED MICROBIOLOGY 2016; 76:27-78. [PMID: 21924971 DOI: 10.1016/b978-0-12-387048-3.00002-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Light represents an important environmental cue, which provides information enabling fungi to prepare and react to the different ambient conditions between day and night. This adaptation requires both anticipation of the changing conditions, which is accomplished by daily rhythmicity of gene expression brought about by the circadian clock, and reaction to sudden illumination. Besides perception of the light signal, also integration of this signal with other environmental cues, most importantly nutrient availability, necessitates light-dependent regulation of signal transduction pathways and metabolic pathways. An influence of light and/or the circadian clock is known for the cAMP pathway, heterotrimeric G-protein signaling, mitogen-activated protein kinases, two-component phosphorelays, and Ca(2+) signaling. Moreover, also the target of rapamycin signaling pathway and reactive oxygen species as signal transducing elements are assumed to be connected to the light-response pathway. The interplay of the light-response pathway with signaling cascades results in light-dependent regulation of primary and secondary metabolism, morphology, development, biocontrol activity, and virulence. The frequent use of fungi in biotechnology as well as analysis of fungi in the artificial environment of a laboratory therefore requires careful consideration of still operative evolutionary heritage of these organisms. This review summarizes the diverse effects of light on fungi and the mechanisms they apply to deal both with the information content and with the harmful properties of light. Additionally, the implications of the reaction of fungi to light in a laboratory environment for experimental work and industrial applications are discussed.
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The Fast-Evolving phy-2 Gene Modulates Sexual Development in Response to Light in the Model Fungus Neurospora crassa. mBio 2016; 7:e02148. [PMID: 26956589 PMCID: PMC4810495 DOI: 10.1128/mbio.02148-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Rapid responses to changes in incident light are critical to the guidance of behavior and development in most species. Phytochrome light receptors in particular play key roles in bacterial physiology and plant development, but their functions and regulation are less well understood in fungi. Nevertheless, genome-wide expression measurements provide key information that can guide experiments that reveal how genes respond to environmental signals and clarify their role in development. We performed functional genomic and phenotypic analyses of the two phytochromes in Neurospora crassa, a fungal model adapted to a postfire environment that experiences dramatically variable light conditions. Expression of phy-1 and phy-2 was low in early sexual development and in the case of phy-2 increased in late sexual development. Under light stimulation, strains with the phytochromes deleted exhibited increased expression of sexual development-related genes. Moreover, under red light, the phy-2 knockout strain commenced sexual development early. In the evolution of phytochromes within ascomycetes, at least two duplications have occurred, and the faster-evolving phy-2 gene has frequently been lost. Additionally, the three key cysteine sites that are critical for bacterial and plant phytochrome function are not conserved within fungal phy-2 homologs. Through the action of phytochromes, transitions between asexual and sexual reproduction are modulated by light level and light quality, presumably as an adaptation for fast asexual growth and initiation of sexual reproduction of N. crassa in exposed postfire ecosystems. Environmental signals, including light, play critical roles in regulating fungal growth and pathogenicity, and balance of asexual and sexual reproduction is critical in fungal pathogens’ incidence, virulence, and distribution. Red light sensing by phytochromes is well known to play critical roles in bacterial physiology and plant development. Homologs of phytochromes were first discovered in the fungal model Neurospora crassa and then subsequently in diverse other fungi, including many plant pathogens. Our study investigated the evolution of red light sensors in ascomycetes and confirmed—using the model fungus Neurospora crassa—their roles in modulating the asexual-sexual reproduction balance in fungi. Our findings also provide a key insight into one of the most poorly understood aspects of fungal biology, suggesting that further study of the function of phytochromes in fungi is critical to reveal the genetic basis of the asexual-sexual switch responsible for fungal growth and distribution, including diverse and destructive plant pathogens.
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Schmoll M, Dattenböck C, Carreras-Villaseñor N, Mendoza-Mendoza A, Tisch D, Alemán MI, Baker SE, Brown C, Cervantes-Badillo MG, Cetz-Chel J, Cristobal-Mondragon GR, Delaye L, Esquivel-Naranjo EU, Frischmann A, Gallardo-Negrete JDJ, García-Esquivel M, Gomez-Rodriguez EY, Greenwood DR, Hernández-Oñate M, Kruszewska JS, Lawry R, Mora-Montes HM, Muñoz-Centeno T, Nieto-Jacobo MF, Nogueira Lopez G, Olmedo-Monfil V, Osorio-Concepcion M, Piłsyk S, Pomraning KR, Rodriguez-Iglesias A, Rosales-Saavedra MT, Sánchez-Arreguín JA, Seidl-Seiboth V, Stewart A, Uresti-Rivera EE, Wang CL, Wang TF, Zeilinger S, Casas-Flores S, Herrera-Estrella A. The Genomes of Three Uneven Siblings: Footprints of the Lifestyles of Three Trichoderma Species. Microbiol Mol Biol Rev 2016; 80:205-327. [PMID: 26864432 PMCID: PMC4771370 DOI: 10.1128/mmbr.00040-15] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The genus Trichoderma contains fungi with high relevance for humans, with applications in enzyme production for plant cell wall degradation and use in biocontrol. Here, we provide a broad, comprehensive overview of the genomic content of these species for "hot topic" research aspects, including CAZymes, transport, transcription factors, and development, along with a detailed analysis and annotation of less-studied topics, such as signal transduction, genome integrity, chromatin, photobiology, or lipid, sulfur, and nitrogen metabolism in T. reesei, T. atroviride, and T. virens, and we open up new perspectives to those topics discussed previously. In total, we covered more than 2,000 of the predicted 9,000 to 11,000 genes of each Trichoderma species discussed, which is >20% of the respective gene content. Additionally, we considered available transcriptome data for the annotated genes. Highlights of our analyses include overall carbohydrate cleavage preferences due to the different genomic contents and regulation of the respective genes. We found light regulation of many sulfur metabolic genes. Additionally, a new Golgi 1,2-mannosidase likely involved in N-linked glycosylation was detected, as were indications for the ability of Trichoderma spp. to generate hybrid galactose-containing N-linked glycans. The genomic inventory of effector proteins revealed numerous compounds unique to Trichoderma, and these warrant further investigation. We found interesting expansions in the Trichoderma genus in several signaling pathways, such as G-protein-coupled receptors, RAS GTPases, and casein kinases. A particularly interesting feature absolutely unique to T. atroviride is the duplication of the alternative sulfur amino acid synthesis pathway.
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Affiliation(s)
- Monika Schmoll
- Austrian Institute of Technology, Department Health and Environment, Bioresources Unit, Tulln, Austria
| | - Christoph Dattenböck
- Austrian Institute of Technology, Department Health and Environment, Bioresources Unit, Tulln, Austria
| | | | | | - Doris Tisch
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | - Mario Ivan Alemán
- Cinvestav, Department of Genetic Engineering, Irapuato, Guanajuato, Mexico
| | - Scott E Baker
- Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Christopher Brown
- University of Otago, Department of Biochemistry and Genetics, Dunedin, New Zealand
| | | | - José Cetz-Chel
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
| | | | - Luis Delaye
- Cinvestav, Department of Genetic Engineering, Irapuato, Guanajuato, Mexico
| | | | - Alexa Frischmann
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | | | - Monica García-Esquivel
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
| | | | - David R Greenwood
- The University of Auckland, School of Biological Sciences, Auckland, New Zealand
| | - Miguel Hernández-Oñate
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
| | - Joanna S Kruszewska
- Polish Academy of Sciences, Institute of Biochemistry and Biophysics, Laboratory of Fungal Glycobiology, Warsaw, Poland
| | - Robert Lawry
- Lincoln University, Bio-Protection Research Centre, Lincoln, Canterbury, New Zealand
| | | | | | | | | | | | | | - Sebastian Piłsyk
- Polish Academy of Sciences, Institute of Biochemistry and Biophysics, Laboratory of Fungal Glycobiology, Warsaw, Poland
| | - Kyle R Pomraning
- Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Aroa Rodriguez-Iglesias
- Austrian Institute of Technology, Department Health and Environment, Bioresources Unit, Tulln, Austria
| | | | | | - Verena Seidl-Seiboth
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | | | | | - Chih-Li Wang
- National Chung-Hsing University, Department of Plant Pathology, Taichung, Taiwan
| | - Ting-Fang Wang
- Academia Sinica, Institute of Molecular Biology, Taipei, Taiwan
| | - Susanne Zeilinger
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria University of Innsbruck, Institute of Microbiology, Innsbruck, Austria
| | | | - Alfredo Herrera-Estrella
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
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Cell fusion in Neurospora crassa. Curr Opin Microbiol 2015; 28:53-9. [DOI: 10.1016/j.mib.2015.08.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 08/10/2015] [Accepted: 08/11/2015] [Indexed: 12/22/2022]
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Wang CL, Shaw BD. F-actin localization dynamics during appressorium formation in Colletotrichum graminicola. Mycologia 2015; 108:506-14. [PMID: 26297784 DOI: 10.3852/15-068] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 07/17/2015] [Indexed: 11/10/2022]
Abstract
Appressoria are essential penetration structures for many phytopathogenic fungi. Here F-actin localization dynamics were documented during appressorium formation in vitro and in planta in Colletotrichum graminicola Four discernible stages of dynamic F-actin distribution occurring in a programmed order were documented from differentiation of appressoria to formation of penetration pores: (stage A) from germ tube enlargement to complete expansion of the appressorium; (stage S) septation occurs; (stage L) a long period of low F-actin activity; (stage P) the penetration pore forms. The F-actin subcellular localization corresponded to each stage. A distinct redistribution of actin cables occurred at the transition from stage A to stage S. The in planta assays revealed that F-actin also assembled in invasive hyphae and that actin cables might play an essential role for penetration-peg development. The F-actin localization distribution may be used as a subcellular marker to define the developmental stages during appressorium formation.
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Affiliation(s)
- Chih-Li Wang
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, and Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan
| | - Brian D Shaw
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas
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Chen F, Chen XZ, Su XY, Qin LN, Huang ZB, Tao Y, Dong ZY. An Ime2-like mitogen-activated protein kinase is involved in cellulase expression in the filamentous fungus Trichoderma reesei. Biotechnol Lett 2015; 37:2055-62. [DOI: 10.1007/s10529-015-1888-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 06/10/2015] [Indexed: 11/28/2022]
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