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Hai D, Li J, Jiang D, Cheng J, Fu Y, Xiao X, Yin H, Lin Y, Chen T, Li B, Yu X, Cai Q, Chen W, Kotta-Loizou I, Xie J. Plants interfere with non-self recognition of a phytopathogenic fungus via proline accumulation to facilitate mycovirus transmission. Nat Commun 2024; 15:4748. [PMID: 38834585 DOI: 10.1038/s41467-024-49110-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 05/17/2024] [Indexed: 06/06/2024] Open
Abstract
Non-self recognition is a fundamental aspect of life, serving as a crucial mechanism for mitigating proliferation of molecular parasites within fungal populations. However, studies investigating the potential interference of plants with fungal non-self recognition mechanisms are limited. Here, we demonstrate a pronounced increase in the efficiency of horizontal mycovirus transmission between vegetatively incompatible Sclerotinia sclerotiorum strains in planta as compared to in vitro. This increased efficiency is associated with elevated proline concentration in plants following S. sclerotiorum infection. This surge in proline levels attenuates the non-self recognition reaction among fungi by inhibition of cell death, thereby facilitating mycovirus transmission. Furthermore, our field experiments reveal that the combined deployment of hypovirulent S. sclerotiorum strains harboring hypovirulence-associated mycoviruses (HAVs) together with exogenous proline confers substantial protection to oilseed rape plants against virulent S. sclerotiorum. This unprecedented discovery illuminates a novel pathway by which plants can counteract S. sclerotiorum infection, leveraging the weakening of fungal non-self recognition and promotion of HAVs spread. These promising insights provide an avenue to explore for developing innovative biological control strategies aimed at mitigating fungal diseases in plants by enhancing the efficacy of horizontal HAV transmission.
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Affiliation(s)
- Du Hai
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Jincang Li
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Daohong Jiang
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Jiasen Cheng
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yanping Fu
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Xueqiong Xiao
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Huanran Yin
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, China
| | - Yang Lin
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Tao Chen
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Bo Li
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Xiao Yu
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Qing Cai
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Wei Chen
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, China
| | - Ioly Kotta-Loizou
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield, UK
- Department of Life Sciences, Imperial College London, London, UK
| | - Jiatao Xie
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China.
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China.
- Hubei Hongshan Laboratory, Wuhan, Hubei, China.
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2
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Kerkaert JD, Huberman LB. Regulation of nutrient utilization in filamentous fungi. Appl Microbiol Biotechnol 2023; 107:5873-5898. [PMID: 37540250 PMCID: PMC10983054 DOI: 10.1007/s00253-023-12680-4] [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: 04/19/2023] [Revised: 06/29/2023] [Accepted: 07/04/2023] [Indexed: 08/05/2023]
Abstract
Organisms must accurately sense and respond to nutrients to survive. In filamentous fungi, accurate nutrient sensing is important in the establishment of fungal colonies and in continued, rapid growth for the exploitation of environmental resources. To ensure efficient nutrient utilization, fungi have evolved a combination of activating and repressing genetic networks to tightly regulate metabolic pathways and distinguish between preferred nutrients, which require minimal energy and resources to utilize, and nonpreferred nutrients, which have more energy-intensive catabolic requirements. Genes necessary for the utilization of nonpreferred carbon sources are activated by transcription factors that respond to the presence of the specific nutrient and repressed by transcription factors that respond to the presence of preferred carbohydrates. Utilization of nonpreferred nitrogen sources generally requires two transcription factors. Pathway-specific transcription factors respond to the presence of a specific nonpreferred nitrogen source, while another transcription factor activates genes in the absence of preferred nitrogen sources. In this review, we discuss the roles of transcription factors and upstream regulatory genes that respond to preferred and nonpreferred carbon and nitrogen sources and their roles in regulating carbon and nitrogen catabolism. KEY POINTS: • Interplay of activating and repressing transcriptional networks regulates catabolism. • Nutrient-specific activating transcriptional pathways provide metabolic specificity. • Repressing regulatory systems differentiate nutrients in mixed nutrient environments.
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Affiliation(s)
- Joshua D Kerkaert
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | - Lori B Huberman
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA.
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3
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Cea-Sánchez S, Corrochano-Luque M, Gutiérrez G, Glass NL, Cánovas D, Corrochano LM. Transcriptional Regulation by the Velvet Protein VE-1 during Asexual Development in the Fungus Neurospora crassa. mBio 2022; 13:e0150522. [PMID: 35913159 PMCID: PMC9426599 DOI: 10.1128/mbio.01505-22] [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: 05/24/2022] [Accepted: 07/13/2022] [Indexed: 11/23/2022] Open
Abstract
Asexual reproduction in fungi facilitates the dispersal and colonization of new substrates and, in pathogenic fungi, allows infection of plants and animals. The velvet complex is a fungus-specific protein complex that participates in the regulation of gene expression in response to environmental signals like light, as well as developmental processes, pathogenesis, and secondary metabolism. The velvet complex in the fungus Neurospora crassa is composed of three proteins, VE-1, VE-2, and LAE-1. Mutations in ve-1 or ve-2, but not in lae-1, led to shorter heights of aerial tissue, a mixture of aerial hyphae and developing macroconidia, and increased microconidiation when they were combined with mutations in the transcription factor gene fl. VE-2 and LAE-1 were detected during vegetative growth and conidiation, unlike VE-1, which was mostly observed in samples obtained from submerged vegetative hyphae. We propose that VE-1 is the limiting component of the velvet complex during conidiation and has a major role in the transcriptional regulation of conidiation. Characterization of the role of VE-1 during mycelial growth and asexual development (conidiation) by transcriptome sequencing (RNA-seq) experiments allowed the identification of a set of genes regulated by VE-1 that participate in the regulation of conidiation, most notably the transcription factor genes vib-1 and fl. We propose that VE-1 and VE-2 regulate the development of aerial tissue and the balance between macro- and microconidiation in coordination with FL and VIB-1. IMPORTANCE Most fungi disperse in nature and infect new hosts by producing vegetative spores or conidia during asexual development. This is a process that is regulated by environmental signals like light and the availability of nutrients. A protein complex, the velvet complex, participates in the integration of environmental signals to regulate conidiation. We have found that a key component of this complex in the fungus Neurospora crassa, VE-1, has a major role in the regulation of transcription during conidiation. VE-1 regulates a large number of genes, including the genes for the transcription factors FL and VIB-1. Our results will help to understand how environmental signals are integrated in the fungal cell to regulate development.
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Affiliation(s)
- Sara Cea-Sánchez
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | | | - Gabriel Gutiérrez
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - N. Louise Glass
- Plant and Microbial Biology Department, University of California, Berkeley, Berkeley, California, USA
| | - David Cánovas
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Luis M. Corrochano
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
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4
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Transcription Factor Mavib-1 Negatively Regulates Conidiation by Affecting Utilization of Carbon and Nitrogen Source in Metarhizium acridum. J Fungi (Basel) 2022; 8:jof8060594. [PMID: 35736077 PMCID: PMC9224900 DOI: 10.3390/jof8060594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/22/2022] [Accepted: 05/29/2022] [Indexed: 11/17/2022] Open
Abstract
Conidium is the main infection unit and reproductive unit of pathogenic fungi. Exploring the mechanism of conidiation and its regulation contributes to understanding the pathogenicity of pathogenic fungi. Vib-1, a transcription factor, was reported to participate in the conidiation process. However, the regulation mechanism of Vib-1 in conidiation is still unclear. In this study, we analyzed the function of Vib-1 and its regulation mechanism in conidiation through knocking out and overexpression of Vib-1 in entomopathogenic fungus Metarhizium acridum. Results showed that the colonial growth of Mavib-1 disruption mutant (ΔMavib-1) was significantly decreased, and conidiation was earlier compared to wild type (WT), while overexpression of Mavib-1 led to a delayed conidiation especially when carbon or nitrogen sources were insufficient. Overexpression of Mavib-1 resulted in a conidiation pattern shift from microcycle conidiation to normal conidiation on nutrient-limited medium. These results indicated that Mavib-1 acted as a positive regulator in vegetative growth and a negative regulator in conidiation by affecting utilization of carbon and nitrogen sources in M. acridum. Transcription profile analysis demonstrated that many genes related to carbon and nitrogen source metabolisms were differentially expressed in ΔMavib-1 and OE strains compared to WT. Moreover, Mavib-1 affects the conidial germination, tolerance to UV-B and heat stresses, cell wall integrity, conidial surface morphology and conidial hydrophobicity in M. acridum. These findings unravel the regulatory mechanism of Mavib-1 in fungal growth and conidiation, and enrich the knowledge to conidiation pattern shift of filamentous fungi.
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Yang X, Huang X, Zhang L, Du L, Liu Y. The
NDT80
‐like transcription factor
CmNdt80a
affects the conidial formation and germination, mycoparasitism, and cell wall integrity of
Coniothyrium minitans. J Appl Microbiol 2022; 133:808-818. [DOI: 10.1111/jam.15575] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 03/06/2022] [Accepted: 04/11/2022] [Indexed: 11/27/2022]
Affiliation(s)
- Xiaoxiang Yang
- Institute of Plant Protection Academy of Agricultural Sciences Sichuan Chengdu China
- Key Laboratory of Integrated Pest Management on Crops in Southwest, Ministry of Agriculture and Rural Affairs Chengdu China
| | - Xiaoqin Huang
- Institute of Plant Protection Academy of Agricultural Sciences Sichuan Chengdu China
- Key Laboratory of Integrated Pest Management on Crops in Southwest, Ministry of Agriculture and Rural Affairs Chengdu China
| | - Lei Zhang
- Institute of Plant Protection Academy of Agricultural Sciences Sichuan Chengdu China
- Key Laboratory of Integrated Pest Management on Crops in Southwest, Ministry of Agriculture and Rural Affairs Chengdu China
| | - Lei Du
- Institute of Plant Protection Academy of Agricultural Sciences Sichuan Chengdu China
| | - Yong Liu
- Institute of Plant Protection Academy of Agricultural Sciences Sichuan Chengdu China
- Key Laboratory of Integrated Pest Management on Crops in Southwest, Ministry of Agriculture and Rural Affairs Chengdu China
- Sichuan Academy of Agricultural Sciences, 20 # Jingjusi Rd Chengdu Sichuan P.R. China
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6
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Song D, Cao Y, Xia Y. MaNsdD regulates conidiation negatively by inhibiting the AbaA expression required for normal conidiation in Metarhizium acridum. Environ Microbiol 2022; 24:2951-2961. [PMID: 35384250 DOI: 10.1111/1462-2920.16000] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 04/04/2022] [Indexed: 11/29/2022]
Abstract
Conidiation necessary for filamentous fungal survival and dispersal, proceeds in two fashions, namely normal conidiation through conidiophores differentiated from hyphae, and microcycle conidiation through conidial budding. Normal conidiation has been well studied whereas mechanisms underlying microcycle conidiation are still largely unknown. Here, we report that a gene (MaNsdD) homologous to NsdD in Aspergillus nidulans serves as a suppressor of normal conidiation but a positive regulator of hyphal development in Metarhizium acridum. Disruption of MaNsdD (ΔMaNsdD) resulted in microcycle conidiation and significantly descended in conidial resistance to heat while improved to UV irradiation. Transcriptomic analysis revealed that many genes involved in conidiation, cell division and cell wall formation were differentially expressed in ΔMaNsdD, and likely associated with the conidiation process. We found that a gene (MaAbaA) homologous to the core asexual development regulator AbaA in A. nidulans, was negatively controlled by MaNsdD. Disruption of MaAbaA led to the abolition of the conidiation process of M. acridum. These findings unravel a novel regulatory mechanism of microcycle conidiation, and add a knowledge to the asexual conidiation pathway of filamentous fungi.
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Affiliation(s)
- Dongxu Song
- School of Life Sciences, Chongqing University, Chongqing, 401331, China.,Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 401331, China.,Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing, China
| | - Yueqing Cao
- School of Life Sciences, Chongqing University, Chongqing, 401331, China.,Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 401331, China.,Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing, China
| | - Yuxian Xia
- School of Life Sciences, Chongqing University, Chongqing, 401331, China.,Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 401331, China.,Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing, China
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7
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Mattam AJ, Chaudhari YB, Velankar HR. Factors regulating cellulolytic gene expression in filamentous fungi: an overview. Microb Cell Fact 2022; 21:44. [PMID: 35317826 PMCID: PMC8939176 DOI: 10.1186/s12934-022-01764-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 02/27/2022] [Indexed: 12/19/2022] Open
Abstract
The growing demand for biofuels such as bioethanol has led to the need for identifying alternative feedstock instead of conventional substrates like molasses, etc. Lignocellulosic biomass is a relatively inexpensive feedstock that is available in abundance, however, its conversion to bioethanol involves a multistep process with different unit operations such as size reduction, pretreatment, saccharification, fermentation, distillation, etc. The saccharification or enzymatic hydrolysis of cellulose to glucose involves a complex family of enzymes called cellulases that are usually fungal in origin. Cellulose hydrolysis requires the synergistic action of several classes of enzymes, and achieving the optimum secretion of these simultaneously remains a challenge. The expression of fungal cellulases is controlled by an intricate network of transcription factors and sugar transporters. Several genetic engineering efforts have been undertaken to modulate the expression of cellulolytic genes, as well as their regulators. This review, therefore, focuses on the molecular mechanism of action of these transcription factors and their effect on the expression of cellulases and hemicellulases.
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Affiliation(s)
- Anu Jose Mattam
- Hindustan Petroleum Green R and D Centre (HPGRDC), KIADB Industrial Area, Tarabanahalli, Devanagundi, Hoskote, Bangalore, 560067, India
| | - Yogesh Babasaheb Chaudhari
- Hindustan Petroleum Green R and D Centre (HPGRDC), KIADB Industrial Area, Tarabanahalli, Devanagundi, Hoskote, Bangalore, 560067, India
| | - Harshad Ravindra Velankar
- Hindustan Petroleum Green R and D Centre (HPGRDC), KIADB Industrial Area, Tarabanahalli, Devanagundi, Hoskote, Bangalore, 560067, India.
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8
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Rico-Ramírez AM, Pedro Gonçalves A, Louise Glass N. Fungal Cell Death: The Beginning of the End. Fungal Genet Biol 2022; 159:103671. [PMID: 35150840 DOI: 10.1016/j.fgb.2022.103671] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 01/04/2022] [Accepted: 01/29/2022] [Indexed: 11/04/2022]
Abstract
Death is an important part of an organism's existence and also marks the end of life. On a cellular level, death involves the execution of complex processes, which can be classified into different types depending on their characteristics. Despite their "simple" lifestyle, fungi carry out highly specialized and sophisticated mechanisms to regulate the way their cells die, and the pathways underlying these mechanisms are comparable with those of plants and metazoans. This review focuses on regulated cell death in fungi and discusses the evidence for the occurrence of apoptotic-like, necroptosis-like, pyroptosis-like death, and the role of the NLR proteins in fungal cell death. We also describe recent data on meiotic drive elements involved in "spore killing" and the molecular basis of allorecognition-related cell death during cell fusion of genetically dissimilar cells. Finally, we discuss how fungal regulated cell death can be relevant in developing strategies to avoid resistance and tolerance to antifungal agents.
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Affiliation(s)
- Adriana M Rico-Ramírez
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720
| | - A Pedro Gonçalves
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan City, 701, Taiwan
| | - N Louise Glass
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720.
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9
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Sun Y, Qian Y, Zhang J, Yao C, Wang Y, Liu H, Zhong Y. Development of a novel expression platform for heterologous protein production via deleting the p53-like regulator Vib1 in Trichoderma reesei. Enzyme Microb Technol 2022; 155:109993. [DOI: 10.1016/j.enzmictec.2022.109993] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 01/03/2022] [Accepted: 01/11/2022] [Indexed: 02/06/2023]
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10
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Atriztán-Hernández K, Herrera-Estrella A. Drosophila attack inhibits hyphal regeneration and defense mechanisms activation for the fungus Trichoderma atroviride. THE ISME JOURNAL 2022; 16:149-158. [PMID: 34282283 PMCID: PMC8692604 DOI: 10.1038/s41396-021-01068-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 06/30/2021] [Accepted: 07/09/2021] [Indexed: 02/07/2023]
Abstract
The capability to respond to wounding is a process shared by organisms of different kingdoms that can result in the regeneration of whole-body parts or lost structures or organs. Filamentous fungi constitute a rich food source that ensures survival and reproduction of their predators and are therefore continuously exposed to mechanical damage. Nevertheless, our understanding of how fungi respond to wounding and predators is scarce. Fungi like plants and animals respond to injury recognizing Damage- and Microbe-Associated Molecular Patterns (DAMPs/MAMPs) that activate Ca2+ and Mitogen-Activated Protein Kinase dependent signaling for the activation of defense mechanisms. During herbivory, plants, in addition to activating pathways related to injury, activate specific responses to combat their predators. Using a transcriptional approach, we studied the capacity of the filamentous fungus Trichoderma atroviride to activate specific responses to injury and attack by different arthropods. Attack by Drosophila melanogaster inhibited the transcriptional activation of genes required for hyphal regeneration, and the fungal innate immune and chemical defense responses. We also provide mechanistic insight of this inhibition involving components of the D. melanogaster salivary glands that repress the expression of a set of genes and block hyphal regeneration.
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11
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Pang AP, Zhang F, Hu X, Luo Y, Wang H, Durrani S, Wu FG, Li BZ, Zhou Z, Lu Z, Lin F. Glutamine involvement in nitrogen regulation of cellulase production in fungi. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:199. [PMID: 34645509 PMCID: PMC8513308 DOI: 10.1186/s13068-021-02046-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/23/2021] [Indexed: 05/27/2023]
Abstract
BACKGROUND Cellulase synthesized by fungi can environment-friendly and sustainably degrades cellulose to fermentable sugars for producing cellulosic biofuels, biobased medicine and fine chemicals. Great efforts have been made to study the regulation mechanism of cellulase biosynthesis in fungi with the focus on the carbon sources, while little attention has been paid to the impact and regulation mechanism of nitrogen sources on cellulase production. RESULTS Glutamine displayed the strongest inhibition effect on cellulase biosynthesis in Trichoderma reesei, followed by yeast extract, urea, tryptone, ammonium sulfate and L-glutamate. Cellulase production, cell growth and sporulation in T. reesei RUT-C30 grown on cellulose were all inhibited with the addition of glutamine (a preferred nitrogen source) with no change for mycelium morphology. This inhibition effect was attributed to both L-glutamine itself and the nitrogen excess induced by its presence. In agreement with the reduced cellulase production, the mRNA levels of 44 genes related to the cellulase production were decreased severely in the presence of glutamine. The transcriptional levels of genes involved in other nitrogen transport, ribosomal biogenesis and glutamine biosynthesis were decreased notably by glutamine, while the expression of genes relevant to glutamate biosynthesis, amino acid catabolism, and glutamine catabolism were increased noticeably. Moreover, the transcriptional level of cellulose signaling related proteins ooc1 and ooc2, and the cellular receptor of rapamycin trFKBP12 was increased remarkably, whose deletion exacerbated the cellulase depression influence of glutamine. CONCLUSION Glutamine may well be the metabolite effector in nitrogen repression of cellulase synthesis, like the role of glucose plays in carbon catabolite repression. Glutamine under excess nitrogen condition repressed cellulase biosynthesis significantly as well as cell growth and sporulation in T. reesei RUT-C30. More importantly, the presence of glutamine notably impacted the transport and metabolism of nitrogen. Genes ooc1, ooc2, and trFKBP12 are associated with the cellulase repression impact of glutamine. These findings advance our understanding of nitrogen regulation of cellulase production in filamentous fungi, which would aid in the rational design of strains and fermentation strategies for cellulase production in industry.
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Affiliation(s)
- Ai-Ping Pang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Funing Zhang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Xin Hu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Yongsheng Luo
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Haiyan Wang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Samran Durrani
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Fu-Gen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Bing-Zhi Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Zhihua Zhou
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
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12
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Role of AcndtA in cleistothecium formation, osmotic stress response, pigmentation and carbon metabolism of Aspergillus cristatus. Fungal Biol 2021; 125:749-763. [PMID: 34537171 DOI: 10.1016/j.funbio.2021.04.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/05/2021] [Accepted: 04/27/2021] [Indexed: 11/22/2022]
Abstract
As the dominant fungus during the fermentation of Fuzhuan brick tea, Aspergillus cristatus is easily induced to undergo a sexual cycle under low-salt stress. However, the underlying regulatory mechanism of sexual reproduction is unclear. Here, we report a P53-like transcription factor AcndtA, which encodes an NDT80 DNA binding protein and regulates fungal reproduction, pigmentation and the stress response. Both insertion and deletion mutants of AcndtA exhibited a complete blockade of cleistothecium formation, and overexpressing AcndtA strains (OE: AcndtA) exhibited significantly reduced cleistothecium production, indicating that AcndtA plays a vital role in sexual development. Osmotic stress tests showed that overexpression of AcndtA had a negative impact on growth and conidia production. Additionally, AcndtA insertion, deletion and overexpression mutants exhibited reduced pigment formation. All the above developmental defects were reversed by the re-introduction of the AcndtA gene in ΔAcndtA. Moreover, the growth of AcndtA mutants in carbon-limited medium was better than that of the WT and OE: AcndtA strains, indicating that AcndtA is involved in carbon metabolism. Transcriptional profiling data showed that AcndtA regulated the expression of several genes related to development, osmotic stress and carbon metabolism.
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Chen X, Song B, Liu M, Qin L, Dong Z. Understanding the Role of Trichoderma reesei Vib1 in Gene Expression during Cellulose Degradation. J Fungi (Basel) 2021; 7:jof7080613. [PMID: 34436152 PMCID: PMC8397228 DOI: 10.3390/jof7080613] [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: 07/07/2021] [Revised: 07/26/2021] [Accepted: 07/26/2021] [Indexed: 11/17/2022] Open
Abstract
Vib1, a member of the Ndt80/PhoG-like transcription factor family, has been shown to be essential for cellulase production of Trichoderma reesei. Here, we combined transcriptomic and genetic analyses to gain mechanistic insights into the roles of Vib1 during cellulose degradation. Our transcriptome analysis showed that the vib1 deletion caused 586 genes with decreased expression and 431 genes with increased expression on cellulose. The downregulated genes were enriched for Gene Ontology terms associated with carbohydrate metabolism, transmembrane transport, oxidoreductase activity, and transcription factor activity. Of the 258 genes induced by cellulose, 229 showed no or decreased expression in Δvib1 on cellulose, including almost all (hemi)cellulase genes, crucial sugar transporter genes (IDs:69957, 3405), and the genes encoding main transcriptional activators Xyr1 and Ace3. Additionally, Vib1 also regulated the expression of genes involved in secondary metabolism. Further comparison of the transcriptomes of Δvib1 and Δxyr1 in cellulose revealed that the genes regulated by Vib1 had much overlap with Xyr1 targets especially for the gene set induced by cellulose, presumably whose expression requires the cooperativity between Vib1 and Xyr1. Genetic evidence indicated that Vib1 regulates cellulase gene expression partially via Xyr1. Our results will provide new clues for strain improvement.
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Affiliation(s)
- Xiuzhen Chen
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.C.); (B.S.); (M.L.)
| | - Bingran Song
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.C.); (B.S.); (M.L.)
| | - Minglu Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.C.); (B.S.); (M.L.)
| | - Lina Qin
- National and Local Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou 350117, China;
| | - Zhiyang Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.C.); (B.S.); (M.L.)
- Correspondence:
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14
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Yow AG, Zhang Y, Bansal K, Eacker SM, Sullivan S, Liachko I, Cubeta MA, Rollins JA, Ashrafi H. Genome sequence of Monilinia vaccinii-corymbosi sheds light on mummy berry disease infection of blueberry and mating type. G3-GENES GENOMES GENETICS 2021; 11:6062400. [PMID: 33598705 PMCID: PMC8022979 DOI: 10.1093/g3journal/jkaa052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 10/29/2020] [Indexed: 11/22/2022]
Abstract
Mummy berry disease, caused by the fungal pathogen Monilinia vaccinii-corymbosi (Mvc), is one of the most economically important diseases of blueberries in North America. Mvc is capable of inducing two separate blighting stages during its life cycle. Infected fruits are rendered mummified and unmarketable. Genomic data for this pathogen is lacking, but could be useful in understanding the reproductive biology of Mvc and the mechanisms it deploys to facilitate host infection. In this study, PacBio sequencing and Hi-C interaction data were utilized to create a chromosome-scale reference genome for Mvc. The genome comprises nine chromosomes with a total length of 30 Mb, an N50 length of 4.06 Mb, and an average 413X sequence coverage. A total of 9399 gene models were predicted and annotated, and BUSCO analysis revealed that 98% of 1,438 searched conserved eukaryotic genes were present in the predicted gene set. Potential effectors were identified, and the mating-type (MAT) locus was characterized. Biotrophic effectors allow the pathogen to avoid recognition by the host plant and evade or mitigate host defense responses during the early stages of fruit infection. Following locule colonization, necrotizing effectors promote the mummification of host tissues. Potential biotrophic effectors utilized by Mvc include chorismate mutase for reducing host salicylate and necrotrophic effectors include necrosis-inducing proteins and hydrolytic enzymes for macerating host tissue. The MAT locus sequences indicate the potential for homothallism in the reference genome, but a deletion allele of the MAT locus, characterized in a second isolate, indicates heterothallism. Further research is needed to verify the roles of individual effectors in virulence and to determine the role of the MAT locus in outcrossing and population genotypic diversity.
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Affiliation(s)
- Ashley G Yow
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695, USA
| | - Yucheng Zhang
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | - Kamaldeep Bansal
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | | | | | | | - Marc A Cubeta
- Department of Entomology and Plant Pathology, Center for Integrated Fungal Research, North Carolina State University, Raleigh, NC 27606, USA
| | - Jeffrey A Rollins
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | - Hamid Ashrafi
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695, USA
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15
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Wang JJ, Yin YP, Song JZ, Hu SJ, Cheng W, Qiu L. A p53-like transcription factor, BbTFO1, contributes to virulence and oxidative and thermal stress tolerances in the insect pathogenic fungus, Beauveria bassiana. PLoS One 2021; 16:e0249350. [PMID: 33788872 PMCID: PMC8011754 DOI: 10.1371/journal.pone.0249350] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 03/16/2021] [Indexed: 11/19/2022] Open
Abstract
The p53-like transcription factor (TF) NDT80 plays a vital role in the regulation of pathogenic mechanisms and meiosis in certain fungi. However, the effects of NDT80 on entomopathogenic fungi are still unknown. In this paper, the NDT80 orthologue BbTFO1 was examined in Beauveria bassiana, a filamentous entomopathogenic fungus, to explore the role of an NDT80-like protein for fungal pest control potential. Disruption of BbTFO1 resulted in impaired resistance to oxidative stress (OS) in a growth assay under OS and a 50% minimum inhibitory concentration experiment. Intriguingly, the oxidation resistance changes were accompanied by transcriptional repression of the two key antioxidant enzyme genes cat2 and cat5. ΔBbTFO1 also displayed defective conidial germination, virulence and heat resistance. The specific supplementation of BbTFO1 reversed these phenotypic changes. As revealed by this work, BbTFO1 can affect the transcription of catalase genes and play vital roles in the maintenance of phenotypes associated with the biological control ability of B. bassiana.
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Affiliation(s)
- Juan-Juan Wang
- School of Biological Science and Technology, University of Jinan, Jinan, China
- * E-mail: (JJW); (LQ)
| | - Ya-Ping Yin
- School of Biological Science and Technology, University of Jinan, Jinan, China
| | - Ji-Zheng Song
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
- Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Shun-Juan Hu
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Wen Cheng
- Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Lei Qiu
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
- * E-mail: (JJW); (LQ)
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16
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Belov AA, Witte TE, Overy DP, Smith ML. Transcriptome analysis implicates secondary metabolite production, redox reactions, and programmed cell death during allorecognition in Cryphonectria parasitica. G3-GENES GENOMES GENETICS 2021; 11:6025178. [PMID: 33561228 PMCID: PMC7849911 DOI: 10.1093/g3journal/jkaa021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/16/2020] [Indexed: 02/04/2023]
Abstract
The underlying molecular mechanisms of programmed cell death associated with fungal allorecognition, a form of innate immunity, remain largely unknown. In this study, transcriptome analysis was used to infer mechanisms activated during barrage formation in vic3-incompatible strains of Cryphonectria parasitica, the chestnut blight fungus. Pronounced differential expression occurred in barraging strains of genes involved in mating pheromone (mf2-1, mf2-2), secondary metabolite production, detoxification (including oxidative stress), apoptosis-related, RNA interference, and HET-domain genes. Evidence for secondary metabolite production and reactive oxygen species (ROS) accumulation is supported through UPLC-HRMS analysis and cytological staining, respectively. Differential expression of mating-related genes and HET-domain genes was further examined by RT-qPCR of incompatible interactions involving each of the six vegetative incompatibility (vic) loci in C. parasitica and revealed distinct recognition process networks. We infer that vegetative incompatibility in C. parasitica activates defence reactions that involve secondary metabolism, resulting in increased toxicity of the extra- and intracellular environment. Accumulation of ROS (and other potential toxins) may result in detoxification failure and activation of apoptosis, sporulation, and the expression of associated pheromone genes. The incompatible reaction leaves abundant traces of a process-specific metabolome as conidiation is initiated.
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Affiliation(s)
- Anatoly A Belov
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Thomas E Witte
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - David P Overy
- Agriculture and Agri-Food Canada, Ottawa, ON, K1Y 4X2, Canada
| | - Myron L Smith
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
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17
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Fu FF, Hao Z, Wang P, Lu Y, Xue LJ, Wei G, Tian Y, Hu B, Xu H, Shi J, Cheng T, Wang G, Yi Y, Chen J. Genome Sequence and Comparative Analysis of Colletotrichum gloeosporioides Isolated from Liriodendron Leaves. PHYTOPATHOLOGY 2020; 110:1260-1269. [PMID: 32202483 DOI: 10.1094/phyto-12-19-0452-r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Colletotrichum gloeosporioides is a hemibiotrophic pathogen causing significant losses to economically important crops and forest trees, including Liriodendron. To explore the interaction between C. gloeosporioides and Liriodendron and to identify the candidate genes determining the pathogenesis, we sequenced and assembled the whole genome of C. gloeosporioides Lc1 (CgLc1) using PacBio and Illumina next generation sequencing and performed a comparative genomic analysis between CgLc1 and Cg01, the latter being a described endophytic species of the C. gloeosporioides complex. Gene structure prediction identified 15,744 protein-coding genes and 837 noncoding RNAs. Species-specific genes were characterized using an ortholog analysis followed by a pathway enrichment analysis, which showed that genes specific to CgLc1 were enriched for the arginine biosynthetic process. Furthermore, genome synteny analysis revealed that most of the protein-coding genes fell into collinear blocks. However, two clusters of polyketide synthase genes were identified to be specific for CgLc1, suggesting that they might have an important role in virulence control. Transcriptional regulators coexpressed with polyketide synthase genes were detected through a Weighted Correlation Network Analysis. Taken together, this work provides new insight into the virulence- and pathogenesis-associated genes present in C. gloeosporioides and its possible lifestyle.
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Affiliation(s)
- Fang-Fang Fu
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Zhaodong Hao
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Pengkai Wang
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Ye Lu
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Liang-Jiao Xue
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Guoyu Wei
- Shanghai Municipal Agricultural and Rural Affairs Commission, Shanghai, China
| | - Yanli Tian
- College of Plant Protection and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Baishi Hu
- College of Plant Protection and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Haibin Xu
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, China
| | - Jisen Shi
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Tielong Cheng
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, China
| | - Guibin Wang
- College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Yin Yi
- State Forestry Administration Key Laboratory of Biodiversity Conservation in Karst Mountainous Areas of Southwestern China, Guizhou Normal University, Guiyang, China
- Guizhou Provincial Key Laboratory of Plant Physiology and Developmental Regulation, Guizhou Normal University, Guiyang, China
| | - Jinhui Chen
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- College of Forestry, Nanjing Forestry University, Nanjing, China
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18
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Martins MP, Martinez-Rossi NM, Sanches PR, Rossi A. The PAC-3 transcription factor critically regulates phenotype-associated genes in Neurospora crassa. Genet Mol Biol 2020; 43:e20190374. [PMID: 32584919 PMCID: PMC7355564 DOI: 10.1590/1678-4685-gmb-2019-0374] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 05/08/2020] [Indexed: 12/17/2022] Open
Abstract
Transcription factors play an important role in fungal environmental adaptive process by promoting adjustment to challenging stimuli via gene modulation and activation of signaling networks. The transcription factor encoded by the pac-3/rim101/pacC gene is involved in pH regulation and is associated with a wide variety of cellular functions. The deletion of pac-3 affects fungal development. In Neurospora crassa, the Δpac-3 strain presents diminished aerial growth and reduced conidiation. However, the PAC-3-regulated genes associated with this altered phenotype have not been elucidated. In this study, we used RNA-seq to analyze the phenotypic plasticity induced after pac-3 deletion in the filamentous fungus N. crassa cultivated in media supplemented with sufficient or limited inorganic phosphate. Genes related to morphology, hyphal development, and conidiation were of particular interest in this study. Our results suggest a pac-3 dependency in gene regulation in a Pi-dependent manner. Furthermore, our analysis suggested that the fungus attempts to overcome the deletion effects in a Δpac-3 mutant through a complex combined regulatory mechanism. Finally, the modulatory responses observed in the Δpac-3 strain, a double mutant generated based on the Δmus-52 mutant strain, is strain-specific, highlighting that the phenotypic impact may be attributed to pac-3 absence despite the combined mus-52 deletion.
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Affiliation(s)
- Maíra Pompeu Martins
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Genética, Ribeirão Preto, SP, Brazil
| | - Nilce Maria Martinez-Rossi
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Genética, Ribeirão Preto, SP, Brazil
| | - Pablo Rodrigo Sanches
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Genética, Ribeirão Preto, SP, Brazil
| | - Antonio Rossi
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Genética, Ribeirão Preto, SP, Brazil
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19
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Wu VW, Thieme N, Huberman LB, Dietschmann A, Kowbel DJ, Lee J, Calhoun S, Singan VR, Lipzen A, Xiong Y, Monti R, Blow MJ, O'Malley RC, Grigoriev IV, Benz JP, Glass NL. The regulatory and transcriptional landscape associated with carbon utilization in a filamentous fungus. Proc Natl Acad Sci U S A 2020; 117:6003-6013. [PMID: 32111691 PMCID: PMC7084071 DOI: 10.1073/pnas.1915611117] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Filamentous fungi, such as Neurospora crassa, are very efficient in deconstructing plant biomass by the secretion of an arsenal of plant cell wall-degrading enzymes, by remodeling metabolism to accommodate production of secreted enzymes, and by enabling transport and intracellular utilization of plant biomass components. Although a number of enzymes and transcriptional regulators involved in plant biomass utilization have been identified, how filamentous fungi sense and integrate nutritional information encoded in the plant cell wall into a regulatory hierarchy for optimal utilization of complex carbon sources is not understood. Here, we performed transcriptional profiling of N. crassa on 40 different carbon sources, including plant biomass, to provide data on how fungi sense simple to complex carbohydrates. From these data, we identified regulatory factors in N. crassa and characterized one (PDR-2) associated with pectin utilization and one with pectin/hemicellulose utilization (ARA-1). Using in vitro DNA affinity purification sequencing (DAP-seq), we identified direct targets of transcription factors involved in regulating genes encoding plant cell wall-degrading enzymes. In particular, our data clarified the role of the transcription factor VIB-1 in the regulation of genes encoding plant cell wall-degrading enzymes and nutrient scavenging and revealed a major role of the carbon catabolite repressor CRE-1 in regulating the expression of major facilitator transporter genes. These data contribute to a more complete understanding of cross talk between transcription factors and their target genes, which are involved in regulating nutrient sensing and plant biomass utilization on a global level.
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Affiliation(s)
- Vincent W Wu
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720
- Energy Biosciences Institute, University of California, Berkeley, CA 94704
| | - Nils Thieme
- Holzforschung München, Technical University of Munich School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany
| | - Lori B Huberman
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720
- Energy Biosciences Institute, University of California, Berkeley, CA 94704
| | - Axel Dietschmann
- Holzforschung München, Technical University of Munich School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany
| | - David J Kowbel
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720
| | - Juna Lee
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Sara Calhoun
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Vasanth R Singan
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Anna Lipzen
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Yi Xiong
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720
- Energy Biosciences Institute, University of California, Berkeley, CA 94704
| | - Remo Monti
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Matthew J Blow
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Ronan C O'Malley
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Igor V Grigoriev
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - J Philipp Benz
- Holzforschung München, Technical University of Munich School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany
| | - N Louise Glass
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720;
- Energy Biosciences Institute, University of California, Berkeley, CA 94704
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
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20
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Purev E, Kondo T, Takemoto D, Niones JT, Ojika M. Identification of ε-Poly-L-lysine as an Antimicrobial Product from an Epichloë Endophyte and Isolation of Fungal ε-PL Synthetase Gene. Molecules 2020; 25:molecules25051032. [PMID: 32106587 PMCID: PMC7179176 DOI: 10.3390/molecules25051032] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/20/2020] [Accepted: 02/23/2020] [Indexed: 12/18/2022] Open
Abstract
The endophytic fungus Epichloë festucae is known to produce bioactive metabolites, which consequently protect the host plants from biotic and abiotic stresses. We previously found that the overexpression of vibA (a gene for transcription factor) in E. festucae strain E437 resulted in the secretion of an unknown fungicide. In the present study, the active substance was purified and chemically identified as ε-poly-L-lysine (ε-PL), which consisted of 28–34 lysine units. The productivity was 3.7-fold compared with that of the wild type strain E437. The isolated ε-PL showed inhibitory activity against the spore germination of the plant pathogens Drechslera erythrospila, Botrytis cinerea, and Phytophthora infestans at 1–10 μg/mL. We also isolated the fungal gene “epls” encoding ε-PL synthetase Epls. Overexpression of epls in the wild type strain E437 resulted in the enhanced production of ε-PL by 6.7-fold. Interestingly, overexpression of epls in the different strain E. festucae Fl1 resulted in the production of shorter ε-PL with 8–20 lysine, which exhibited a comparable antifungal activity to the longer one. The results demonstrate the first example of ε-PL synthetase gene from the eukaryotic genomes and suggest the potential of enhanced expression of vibA or/and epls genes in the Epichloë endophyte for constructing pest-tolerant plants.
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Affiliation(s)
- Enkhee Purev
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan; (E.P.); (T.K.)
| | - Tatsuhiko Kondo
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan; (E.P.); (T.K.)
| | - Daigo Takemoto
- Department of Plant Production Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan; (D.T.); (J.T.N.)
| | - Jennifer T. Niones
- Department of Plant Production Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan; (D.T.); (J.T.N.)
- Philippine Rice Research Institute, Science City of Munoz, Nueva Ecija 3119, Philippines
| | - Makoto Ojika
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan; (E.P.); (T.K.)
- Correspondence: ; Tel.: +81-52-789-4116; Fax: +81-52-789-4118
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21
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Novy V, Nielsen F, Seiboth B, Nidetzky B. The influence of feedstock characteristics on enzyme production in Trichoderma reesei: a review on productivity, gene regulation and secretion profiles. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:238. [PMID: 31624500 PMCID: PMC6781402 DOI: 10.1186/s13068-019-1571-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/20/2019] [Indexed: 05/21/2023]
Abstract
Biorefineries, designed for the production of lignocellulose-based chemicals and fuels, are receiving increasing attention from the public, governments, and industries. A major obstacle for biorefineries to advance to commercial scale is the high cost of the enzymes required to derive the fermentable sugars from the feedstock used. As summarized in this review, techno-economic studies suggest co-localization and integration of enzyme manufacturing with the cellulosic biorefinery as the most promising alternative to alleviate this problem. Thus, cultivation of Trichoderma reesei, the principal producer of lignocellulolytic enzymes, on the lignocellulosic biomass processed on-site can reduce the cost of enzyme manufacturing. Further, due to a complex gene regulation machinery, the fungus can adjust the gene expression of the lignocellulolytic enzymes towards the characteristics of the feedstock, increasing the hydrolytic efficiency of the produced enzyme cocktail. Despite extensive research over decades, the underlying regulatory mechanisms are not fully elucidated. One aspect that has received relatively little attention in literature is the influence the characteristics of a lignocellulosic substrate, i.e., its chemical and physical composition, has on the produced enzyme mixture. Considering that the fungus is dependent on efficient enzymatic degradation of the lignocellulose for continuous supply of carbon and energy, a relationship between feedstock characteristics and secretome composition can be expected. The aim of this review was to systematically collect, appraise, and aggregate data and integrate results from studies analyzing enzyme production by T. reesei on insoluble cellulosic model substrates and lignocellulosic biomass. The results show that there is a direct effect of the substrate's complexity (rated by structure, composition of the lignin-carbohydrate complex, and recalcitrance in enzymatic saccharification) on enzyme titers and the composition of specific activities in the secretome. It further shows that process-related factors, such as substrate loading and cultivation set-up, are direct targets for increasing enzyme yields. The literature on transcriptome and secretome composition further supports the proposed influence of substrate-related factors on the expression of lignocellulolytic enzymes. This review provides insights into the interrelation between the characteristics of the substrate and the enzyme production by T. reesei, which may help to advance integrated enzyme manufacturing of substrate-specific enzymes cocktails at scale.
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Affiliation(s)
- Vera Novy
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Graz, Austria
- Present Address: Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, Canada
| | - Fredrik Nielsen
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Graz, Austria
- Present Address: Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, Canada
| | - Bernhard Seiboth
- Institute of Chemical, Environmental and Bioscience Engineering, Vienna University of Technology, Vienna, Austria
- Austrian Centre of Industrial Biotechnology (acib) GmbH, Graz, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Graz, Austria
- Austrian Centre of Industrial Biotechnology (acib) GmbH, Graz, Austria
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Snyman C, Theron LW, Divol B. Understanding the regulation of extracellular protease gene expression in fungi: a key step towards their biotechnological applications. Appl Microbiol Biotechnol 2019; 103:5517-5532. [PMID: 31129742 DOI: 10.1007/s00253-019-09902-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/07/2019] [Accepted: 05/07/2019] [Indexed: 12/20/2022]
Abstract
The secretion of proteases by certain species of yeast and filamentous fungi is of importance not only for their biological function and survival, but also for their biotechnological application to various processes in the food, beverage, and bioprocessing industries. A key step towards understanding the role that these organisms play in their environment, and how their protease-secreting ability may be optimally utilised through industrial applications, involves an evaluation of those factors which influence protease production. The objective of this review is to provide an overview of the findings from investigations directed at elucidating the regulatory mechanisms underlying extracellular protease secretion in yeast and filamentous fungi, and the environmental stimuli that elicit these responses. The influence of nitrogen-, carbon-, and sulphur-containing compounds, as well as proteins, temperature, and pH, on extracellular protease regulation, which is frequently exerted at the transcriptional level, is discussed in particular depth. Protease-secreting organisms of biotechnological interest are also presented in this context, in an effort to explore the areas of industrial significance that could possibly benefit from such knowledge. In this way, the establishment of a platform of existing knowledge regarding fungal protease regulation is attempted, with the particular goal of aiding in the practical application of these organisms to processes that require secretion of this enzyme.
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Affiliation(s)
- C Snyman
- Department of Viticulture and Oenology, Institute for Wine Biotechnology, Private Bag X1, Matieland, 7602, South Africa
| | - L W Theron
- Department of Viticulture and Oenology, Institute for Wine Biotechnology, Private Bag X1, Matieland, 7602, South Africa
| | - B Divol
- Department of Viticulture and Oenology, Institute for Wine Biotechnology, Private Bag X1, Matieland, 7602, South Africa.
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Kulkarni M, Stolp ZD, Hardwick JM. Targeting intrinsic cell death pathways to control fungal pathogens. Biochem Pharmacol 2019; 162:71-78. [PMID: 30660496 DOI: 10.1016/j.bcp.2019.01.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 01/11/2019] [Indexed: 02/07/2023]
Abstract
Fungal pathogens pose an increasing threat to public health. Limited clinical drug regimens and emerging drug-resistant isolates challenge infection control. The global burden of human fungal pathogens is estimated at 1 billion infections and 1.5 million deaths annually. In addition, plant fungal pathogens increasingly threaten global food resources. Novel strategies are needed to combat emerging fungal diseases and pan-resistant fungi. An untapped mechanistically novel approach is to pharmacologically activate the intrinsic cell death pathways encoded by pathogenic fungi. This strategy is analogous to new anti-cancer therapeutics now entering the clinic. Here we summarize the best understood examples of cell death mechanisms encoded by pathogenic fungi, contrast these to mammalian cell death pathways, and highlight the gaps in knowledge towards identifying potential death effectors as druggable targets.
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Affiliation(s)
- Madhura Kulkarni
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, USA
| | - Zachary D Stolp
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, USA
| | - J Marie Hardwick
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, USA; Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, USA.
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Katz ME. Nutrient sensing-the key to fungal p53-like transcription factors? Fungal Genet Biol 2018; 124:8-16. [PMID: 30579885 DOI: 10.1016/j.fgb.2018.12.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/12/2018] [Accepted: 12/18/2018] [Indexed: 02/02/2023]
Abstract
The mammalian tumour suppressor protein, p53, plays an important role in cell cycle control, DNA repair and apoptotic cell death. Transcription factors belonging to the "p53-like" superfamily are found exclusively in the Amorphea branch of eukaryotes, which includes animals, fungi and slime molds. Many members of the p53-like superfamily (proteins containing p53, Rel/Dorsal, T-box, STAT, Runt, Ndt80, and the CSL DNA-binding domains) are involved in development. Two families of p53-like proteins (Ndt80 and CSL) are widespread in fungi as well as animals. The Basidiomycetes and the Ascomycetes have undergone reciprocal loss of the Ndt80 and CSL classes of transcription factors, with the CSL class preserved in only one branch of Ascomycetes and the Ndt80 class found in only one branch of Basidiomycetes. Recent studies have greatly expanded the known functions of fungal Ndt80-like proteins and shown that they play important roles in sexual reproduction, cell death, N-acetylglucosamine sensing and catabolism, secondary metabolism, and production of extracellular hydrolases such as proteases, chitinases and cellulases. In the opportunistic pathogen, Candida albicans, Ndt80-like proteins are essential for hyphal growth and virulence and also play a role in antifungal resistance. These recent studies have confirmed that nutrient sensing is a common feature of fungal Ndt80-like proteins and is also found in fungal CSL-like transcription factors, which in animals is the mediator of Notch signalling. Thus, nutrient sensing may represent the ancestral role of the p53-like superfamily.
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Affiliation(s)
- Margaret E Katz
- Molecular and Cellular Biology, University of New England, Armidale, NSW 2351, Australia.
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Genetic Analysis of NDT80 Family Transcription Factors in Candida albicans Using New CRISPR-Cas9 Approaches. mSphere 2018; 3:3/6/e00545-18. [PMID: 30463924 PMCID: PMC6249646 DOI: 10.1128/msphere.00545-18] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Ndt80 family transcription factors are highly conserved in fungi, where they regulate diverse processes. The human fungal pathogen Candida albicans contains three genes (NDT80, REP1, and RON1) that encode proteins with similarity to Saccharomyces cerevisiae Ndt80, although the homology is restricted to the DNA binding domain. To better understand their role in virulence functions, we used clustered regularly interspaced short palindromic repeat/CRISPR-associated gene 9 (CRISPR/Cas9) to delete the three NDT80-family genes. An ndt80Δ mutant showed strong defects in forming hyphae in response to serum or N-acetylglucosamine (GlcNAc), which was linked to the ability of Ndt80 to regulate the expression of RAS1, an upstream regulator of hyphal signaling. Conversely, the ndt80Δ mutant formed hyphal cells on glycerol medium, indicating that Ndt80 is not required for hyphal growth under all conditions. In contrast to our previously published data, a ron1Δ single mutant could grow and form hyphae in response to GlcNAc. However, deleting RON1 partially restored the ability of an ndt80Δ mutant to form hyphae in response to GlcNAc, indicating a link to GlcNAc signaling. REP1 was required for growth on GlcNAc, as expected, but not for GlcNAc or serum to induce hyphae. The ndt80Δ mutant was defective in growing under stressful conditions, such as elevated temperature, but not the ron1Δ mutant or rep1Δ mutant. Quantitative assays did not reveal any significant differences in the fluconazole susceptibility of the NDT80-family mutants. Interestingly, double and triple mutant analysis did not identify significant genetic interactions for these NDT80 family genes, indicating that they mainly function independently, in spite of their conserved DNA binding domain.IMPORTANCE Transcription factors play key roles in regulating virulence of the human fungal pathogen C. albicans In addition to regulating the expression of virulence factors, they also control the ability of C. albicans to switch to filamentous hyphal growth, which facilitates biofilm formation on medical devices and invasion into tissues. We therefore used new CRISPR/Cas9 methods to examine the effects of deleting three C. albicans genes (NDT80, REP1, and RON1) that encode transcription factors with similar DNA binding domains. Interestingly, double and triple mutant strains mostly showed the combined properties of the single mutants; there was only very limited evidence of synergistic interactions in regulating morphogenesis, stress resistance, and ability to metabolize different sugars. These results demonstrate that NDT80, REP1, and RON1 have distinct functions in regulating C. albicans virulence functions.
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Kurian SM, Di Pietro A, Read ND. Live-cell imaging of conidial anastomosis tube fusion during colony initiation in Fusarium oxysporum. PLoS One 2018; 13:e0195634. [PMID: 29734342 PMCID: PMC5937734 DOI: 10.1371/journal.pone.0195634] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 03/26/2018] [Indexed: 01/07/2023] Open
Abstract
Fusarium oxysporum exhibits conidial anastomosis tube (CAT) fusion during colony initiation to form networks of conidial germlings. Here we determined the optimal culture conditions for this fungus to undergo CAT fusion between microconidia in liquid medium. Extensive high resolution, confocal live-cell imaging was performed to characterise the different stages of CAT fusion, using genetically encoded fluorescent labelling and vital fluorescent organelle stains. CAT homing and fusion were found to be dependent on adhesion to the surface, in contrast to germ tube development which occurs in the absence of adhesion. Staining with fluorescently labelled concanavalin A indicated that the cell wall composition of CATs differs from that of microconidia and germ tubes. The movement of nuclei, mitochondria, vacuoles and lipid droplets through fused germlings was observed by live-cell imaging.
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Affiliation(s)
- Smija M. Kurian
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
| | - Antonio Di Pietro
- Departamento de Genetica, Universidad de Cordoba, Campus Rabanales C5, Cordoba, Spain
| | - Nick D. Read
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
- * E-mail:
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Zhang F, Zhao X, Bai F. Improvement of cellulase production in Trichoderma reesei Rut-C30 by overexpression of a novel regulatory gene Trvib-1. BIORESOURCE TECHNOLOGY 2018; 247:676-683. [PMID: 30060399 DOI: 10.1016/j.biortech.2017.09.126] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/17/2017] [Accepted: 09/18/2017] [Indexed: 05/05/2023]
Abstract
Trichoderma reesei is a widely used cellulase producer, and development of robust strains for improved cellulase production is of great interest. In this study, the gene Trvib-1 encoding a putative transcription factor was overexpressed in T. reesei Rut-C30, and effects on cellulase production by the manipulation as well as corn stover degradation by the crude enzyme were investigated. Cellulase production and protein secretion were significantly improved in the culture of the recombinant T. reesei Vib-1, which were 200% and 219%, respectively, higher than that produced by the parent strain. Cellulase induction was enhanced in the presence of pure cellulose as well as various soluble inducers. Glucose released from the pretreated corn stover hydrolyzed by the crude enzyme in the recombinant strain was improved 40%. These results indicate that the overexpression of Trvib-1 is a feasible strategy for producing cellulase to enhance bioconversion efficiency of lignocellulosic biomass.
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Affiliation(s)
- Fei Zhang
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xinqing Zhao
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Fengwu Bai
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
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28
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Gonçalves AP, Heller J, Daskalov A, Videira A, Glass NL. Regulated Forms of Cell Death in Fungi. Front Microbiol 2017; 8:1837. [PMID: 28983298 PMCID: PMC5613156 DOI: 10.3389/fmicb.2017.01837] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 09/07/2017] [Indexed: 12/15/2022] Open
Abstract
Cell death occurs in all domains of life. While some cells die in an uncontrolled way due to exposure to external cues, other cells die in a regulated manner as part of a genetically encoded developmental program. Like other eukaryotic species, fungi undergo programmed cell death (PCD) in response to various triggers. For example, exposure to external stress conditions can activate PCD pathways in fungi. Calcium redistribution between the extracellular space, the cytoplasm and intracellular storage organelles appears to be pivotal for this kind of cell death. PCD is also part of the fungal life cycle, in which it occurs during sexual and asexual reproduction, aging, and as part of development associated with infection in phytopathogenic fungi. Additionally, a fungal non-self-recognition mechanism termed heterokaryon incompatibility (HI) also involves PCD. Some of the molecular players mediating PCD during HI show remarkable similarities to major constituents involved in innate immunity in metazoans and plants. In this review we discuss recent research on fungal PCD mechanisms in comparison to more characterized mechanisms in metazoans. We highlight the role of PCD in fungi in response to exogenic compounds, fungal development and non-self-recognition processes and discuss identified intracellular signaling pathways and molecules that regulate fungal PCD.
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Affiliation(s)
- A Pedro Gonçalves
- Plant and Microbial Biology Department, University of California, BerkeleyBerkeley, CA, United States
| | - Jens Heller
- Plant and Microbial Biology Department, University of California, BerkeleyBerkeley, CA, United States
| | - Asen Daskalov
- Plant and Microbial Biology Department, University of California, BerkeleyBerkeley, CA, United States
| | - Arnaldo Videira
- Instituto de Ciências Biomédicas de Abel Salazar, Universidade do PortoPorto, Portugal.,I3S - Instituto de Investigação e Inovação em SaúdePorto, Portugal
| | - N Louise Glass
- Plant and Microbial Biology Department, University of California, BerkeleyBerkeley, CA, United States
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Havlik D, Brandt U, Bohle K, Fleißner A. Establishment of Neurospora crassa as a host for heterologous protein production using a human antibody fragment as a model product. Microb Cell Fact 2017; 16:128. [PMID: 28743272 PMCID: PMC5526295 DOI: 10.1186/s12934-017-0734-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/05/2017] [Indexed: 12/16/2022] Open
Abstract
Background Filamentous fungi are commonly used as production hosts for bulk enzymes in biotechnological applications. Their robust and quick growth combined with their ability to secrete large amounts of protein directly into the culture medium makes fungi appealing organisms for the generation of novel production systems. The red bread mold Neurospora crassa has long been established as a model system in basic research. It can be very easily genetically manipulated and a wealth of molecular tools and mutants are available. In addition, N. crassa is very fast growing and non-toxic. All of these features point to a high but so far untapped potential of this fungus for biotechnological applications. In this study, we used genetic engineering and bioprocess development in a design-build-test-cycle process to establish N. crassa as a production host for heterologous proteins. Results The human antibody fragment HT186-D11 was fused to a truncated version of the endogenous enzyme glucoamylase (GLA-1), which served as a carrier protein to achieve secretion into the culture medium. A modular expression cassette was constructed and tested under the control of different promoters. Protease activity was identified as a major limitation of the production strain, and the effects of different mutations causing protease deficiencies were compared. Furthermore, a parallel bioreactor system (1 L) was employed to develop and optimize a production process, including the comparison of different culture media and cultivation parameters. After successful optimization of the production strain and the cultivation conditions an exemplary scale up to a 10 L stirred tank reactor was performed. Conclusions The data of this study indicate that N. crassa is suited for the production and secretion of heterologous proteins. Controlling expression by the optimized promoter Pccg1nr in a fourfold protease deletion strain resulted in the successful secretion of the heterologous product with estimated yields of 3 mg/L of the fusion protein. The fungus could easily be cultivated in bioreactors and a first scale-up was successful. The system holds therefore much potential, warranting further efforts in optimization. Electronic supplementary material The online version of this article (doi:10.1186/s12934-017-0734-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- David Havlik
- Division of Pharmaceutical Biotechnology, Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM), Inhoffenstr. 7, Braunschweig, 38124, Germany.,Institut für Genetik, Technische Universität Braunschweig, Spielmannstr. 7, 38106, Braunschweig, Germany.,Navigo Proteins GmbH, Heinrich-Damerow-Str. 1, 06120, Halle (Saale), Germany
| | - Ulrike Brandt
- Institut für Genetik, Technische Universität Braunschweig, Spielmannstr. 7, 38106, Braunschweig, Germany
| | - Kathrin Bohle
- Division of Pharmaceutical Biotechnology, Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM), Inhoffenstr. 7, Braunschweig, 38124, Germany
| | - André Fleißner
- Institut für Genetik, Technische Universität Braunschweig, Spielmannstr. 7, 38106, Braunschweig, Germany.
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30
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A fungal transcription factor essential for starch degradation affects integration of carbon and nitrogen metabolism. PLoS Genet 2017; 13:e1006737. [PMID: 28467421 PMCID: PMC5435353 DOI: 10.1371/journal.pgen.1006737] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 05/17/2017] [Accepted: 04/05/2017] [Indexed: 12/19/2022] Open
Abstract
In Neurospora crassa, the transcription factor COL-26 functions as a regulator of glucose signaling and metabolism. Its loss leads to resistance to carbon catabolite repression. Here, we report that COL-26 is necessary for the expression of amylolytic genes in N. crassa and is required for the utilization of maltose and starch. Additionally, the Δcol-26 mutant shows growth defects on preferred carbon sources, such as glucose, an effect that was alleviated if glutamine replaced ammonium as the primary nitrogen source. This rescue did not occur when maltose was used as a sole carbon source. Transcriptome and metabolic analyses of the Δcol-26 mutant relative to its wild type parental strain revealed that amino acid and nitrogen metabolism, the TCA cycle and GABA shunt were adversely affected. Phylogenetic analysis showed a single col-26 homolog in Sordariales, Ophilostomatales, and the Magnaporthales, but an expanded number of col-26 homologs in other filamentous fungal species. Deletion of the closest homolog of col-26 in Trichoderma reesei, bglR, resulted in a mutant with similar preferred carbon source growth deficiency, and which was alleviated if glutamine was the sole nitrogen source, suggesting conservation of COL-26 and BglR function. Our finding provides novel insight into the role of COL-26 for utilization of starch and in integrating carbon and nitrogen metabolism for balanced metabolic activities for optimal carbon and nitrogen distribution. In nature, filamentous fungi sense nutrient availability in the surrounding environment and adjust their metabolism for optimal utilization, growth and reproduction. Carbon and nitrogen are two of major elements required for life. Within cells, signals from carbon and nitrogen catabolism are integrated, resulting in balanced metabolic activities for optimal carbon and nitrogen distribution. However, coordination of carbon and nitrogen metabolism is often missed in studies that are based on comparisons between single carbon or nitrogen sources. In this study, we performed systematic transcriptional profiling of Neurospora crassa on different components of starch and identified the transcription factor COL-26 to be an essential regulator for starch utilization and needed for coordinating carbon and nitrogen regulation and metabolism. Proteins with sequence similar to COL-26 widely exist among ascomycete fungi. Here we provide experimental evidence for shared function of a col-26 ortholog in Trichoderma reesei. Our finding provides novel insight into how the regulation of carbon and nitrogen metabolism can be integrated in filamentous fungi by the function of COL-26 and which may aid in the rational design of fungal strains for industrial purposes.
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Abstract
ABSTRACT
For the majority of fungal species, the somatic body of an individual is a network of interconnected cells sharing a common cytoplasm and organelles. This syncytial organization contributes to an efficient distribution of resources, energy, and biochemical signals. Cell fusion is a fundamental process for fungal development, colony establishment, and habitat exploitation and can occur between hyphal cells of an individual colony or between colonies of genetically distinct individuals. One outcome of cell fusion is the establishment of a stable heterokaryon, culminating in benefits for each individual via shared resources or being of critical importance for the sexual or parasexual cycle of many fungal species. However, a second outcome of cell fusion between genetically distinct strains is formation of unstable heterokaryons and the induction of a programmed cell death reaction in the heterokaryotic cells. This reaction of nonself rejection, which is termed heterokaryon (or vegetative) incompatibility, is widespread in the fungal kingdom and acts as a defense mechanism against genome exploitation and mycoparasitism. Here, we review the currently identified molecular players involved in the process of somatic cell fusion and its regulation in filamentous fungi. Thereafter, we summarize the knowledge of the molecular determinants and mechanism of heterokaryon incompatibility and place this phenomenon in the broader context of biotropic interactions and immunity.
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Ivanova C, Ramoni J, Aouam T, Frischmann A, Seiboth B, Baker SE, Le Crom S, Lemoine S, Margeot A, Bidard F. Genome sequencing and transcriptome analysis of Trichoderma reesei QM9978 strain reveals a distal chromosome translocation to be responsible for loss of vib1 expression and loss of cellulase induction. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:209. [PMID: 28912831 PMCID: PMC5588705 DOI: 10.1186/s13068-017-0897-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 08/29/2017] [Indexed: 05/05/2023]
Abstract
BACKGROUND The hydrolysis of biomass to simple sugars used for the production of biofuels in biorefineries requires the action of cellulolytic enzyme mixtures. During the last 50 years, the ascomycete Trichoderma reesei, the main source of industrial cellulase and hemicellulase cocktails, has been subjected to several rounds of classical mutagenesis with the aim to obtain higher production levels. During these random genetic events, strains unable to produce cellulases were generated. Here, whole genome sequencing and transcriptomic analyses of the cellulase-negative strain QM9978 were used for the identification of mutations underlying this cellulase-negative phenotype. RESULTS Sequence comparison of the cellulase-negative strain QM9978 to the reference strain QM6a identified a total of 43 mutations, of which 33 were located either close to or in coding regions. From those, we identified 23 single-nucleotide variants, nine InDels, and one translocation. The translocation occurred between chromosomes V and VII, is located upstream of the putative transcription factor vib1, and abolishes its expression in QM9978 as detected during the transcriptomic analyses. Ectopic expression of vib1 under the control of its native promoter as well as overexpression of vib1 under the control of a strong constitutive promoter restored cellulase expression in QM9978, thus confirming that the translocation event is the reason for the cellulase-negative phenotype. Gene deletion of vib1 in the moderate producer strain QM9414 and in the high producer strain Rut-C30 reduced cellulase expression in both cases. Overexpression of vib1 in QM9414 and Rut-C30 had no effect on cellulase production, most likely because vib1 is already expressed at an optimal level under normal conditions. CONCLUSION We were able to establish a link between a chromosomal translocation in QM9978 and the cellulase-negative phenotype of the strain. We identified the transcription factor vib1 as a key regulator of cellulases in T. reesei whose expression is absent in QM9978. We propose that in T. reesei, as in Neurospora crassa, vib1 is involved in cellulase induction, although the exact mechanism remains to be elucidated. The data presented here show an example of a combined genome sequencing and transcriptomic approach to explain a specific trait, in this case the QM9978 cellulase-negative phenotype, and how it helps to better understand the mechanisms during cellulase gene regulation. When focusing on mutations on the single base-pair level, changes on the chromosome level can be easily overlooked and through this work we provide an example that stresses the importance of the big picture of the genomic landscape during analysis of sequencing data.
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Affiliation(s)
- Christa Ivanova
- IFP Energies Nouvelles, 1-4 Avenue de Bois-Préau, 92852 Rueil-Malmaison, France
- Present Address: Genetics of Biofilms Unit, Department of Microbiology, Institut Pasteur, 25-28 Rue du Dr Roux, 75015 Paris, France
| | - Jonas Ramoni
- Molecular Biotechnology, Research Division Biochemical Technology, Institute of Chemical Engineering, TU-Wien, 1060 Vienna, Austria
| | - Thiziri Aouam
- IFP Energies Nouvelles, 1-4 Avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Alexa Frischmann
- Molecular Biotechnology, Research Division Biochemical Technology, Institute of Chemical Engineering, TU-Wien, 1060 Vienna, Austria
| | - Bernhard Seiboth
- Molecular Biotechnology, Research Division Biochemical Technology, Institute of Chemical Engineering, TU-Wien, 1060 Vienna, Austria
| | - Scott E. Baker
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99354 USA
| | - Stéphane Le Crom
- Evolution Paris Seine-Institut de Biologie Paris Seine (EPS-IBPS), Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, 75005 Paris, France
| | - Sophie Lemoine
- École normale supérieure, PSL Research University, CNRS, Inserm, Institut de Biologie de l’École normale supérieure (IBENS), Plateforme Génomique, 75005 Paris, France
| | - Antoine Margeot
- IFP Energies Nouvelles, 1-4 Avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Frédérique Bidard
- IFP Energies Nouvelles, 1-4 Avenue de Bois-Préau, 92852 Rueil-Malmaison, France
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Role of HxkC, a mitochondrial hexokinase-like protein, in fungal programmed cell death. Fungal Genet Biol 2016; 97:36-45. [DOI: 10.1016/j.fgb.2016.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 11/03/2016] [Accepted: 11/05/2016] [Indexed: 11/21/2022]
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Shalaby S, Larkov O, Lamdan NL, Goldshmidt-Tran O, Horwitz BA. Plant phenolic acids induce programmed cell death of a fungal pathogen: MAPK signaling and survival of Cochliobolus heterostrophus. Environ Microbiol 2016; 18:4188-4199. [PMID: 27631532 DOI: 10.1111/1462-2920.13528] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 09/09/2016] [Indexed: 11/29/2022]
Abstract
Plant aromatic compounds provide signals and a nutrient source to pathogens, and also act as stressors. Structure-activity relationships suggest two pathways sensing these compounds in the maize pathogen Cochliobolus heterostrophus, one triggering a stress response, and one inducing enzymes for their degradation. Focusing on the stress pathway, we found that ferulic acid causes rapid appearance of TUNEL-positive nuclei, dispersion of histone H1:GFP, hyphal shrinkage, and eventually membrane damage. These hallmarks of programmed cell death (PCD) were not seen upon exposure to caffeic acid, a very similar compound. Exposure to ferulic acid dephosphorylated two MAP kinases: Hog1 (stress activated) and Chk1 (pathogenicity related), while increasing phosphorylation of Mps1 (cell integrity related). Mutants lacking Hog1 or Chk1 are hypersensitive to ferulic acid while Mps1 mutants are not. These results implicate three MAPK pathways in the stress response. Ferulic acid and the antifungal fludioxonil have opposite additive effects on survival and on dephosphorylation of Hog1, which is thus implicated in survival. The results may explain why some fungal pathogens of plants undergo cell death early in host invasion, when phenolics are released from plant tissue.
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Affiliation(s)
- Samer Shalaby
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, 3200000, Israel
| | - Olga Larkov
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, 3200000, Israel
| | - Netta-Li Lamdan
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, 3200000, Israel
| | - Orit Goldshmidt-Tran
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, 3200000, Israel
| | - Benjamin A Horwitz
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, 3200000, Israel
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35
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Vegetative incompatibility in fungi: From recognition to cell death, whatever does the trick. FUNGAL BIOL REV 2016. [DOI: 10.1016/j.fbr.2016.08.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Majeská Čudejková M, Vojta P, Valík J, Galuszka P. Quantitative and qualitative transcriptome analysis of four industrial strains of Claviceps purpurea with respect to ergot alkaloid production. N Biotechnol 2016; 33:743-754. [PMID: 26827914 DOI: 10.1016/j.nbt.2016.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 12/22/2015] [Accepted: 01/05/2016] [Indexed: 01/14/2023]
Abstract
The fungus Claviceps purpurea is a biotrophic phytopathogen widely used in the pharmaceutical industry for its ability to produce ergot alkaloids (EAs). The fungus attacks unfertilized ovaries of grasses and forms sclerotia, which represent the only type of tissue where the synthesis of EAs occurs. The biosynthetic pathway of EAs has been extensively studied; however, little is known concerning its regulation. Here, we present the quantitative transcriptome analysis of the sclerotial and mycelial tissues providing a comprehensive view of transcriptional differences between the tissues that produce EAs and those that do not produce EAs and the pathogenic and non-pathogenic lifestyle. The results indicate metabolic changes coupled with sclerotial differentiation, which are likely needed as initiation factors for EA biosynthesis. One of the promising factors seems to be oxidative stress. Here, we focus on the identification of putative transcription factors and regulators involved in sclerotial differentiation, which might be involved in EA biosynthesis. To shed more light on the regulation of EA composition, whole transcriptome analysis of four industrial strains differing in their alkaloid spectra was performed. The results support the hypothesis proposing the composition of the amino acid pool in sclerotia to be an important factor regulating the final structure of the ergopeptines produced by Claviceps purpurea.
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Affiliation(s)
- Mária Majeská Čudejková
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic.
| | - Petr Vojta
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic; Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, Hněvotínská 1333/5, 779 00 Olomouc, Czech Republic
| | - Josef Valík
- Teva Czech Industries s.r.o., Ostravská 305/29, 747 70 Opava-Komárov, Czech Republic
| | - Petr Galuszka
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
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Doyle CE, Kitty Cheung H, Spence KL, Saville BJ. Unh1, an Ustilago maydis Ndt80-like protein, controls completion of tumor maturation, teliospore development, and meiosis. Fungal Genet Biol 2016; 94:54-68. [DOI: 10.1016/j.fgb.2016.07.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 07/04/2016] [Accepted: 07/06/2016] [Indexed: 10/21/2022]
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Shahi S, Fokkens L, Houterman PM, Rep M. Suppressor of fusion, a Fusarium oxysporum homolog of Ndt80, is required for nutrient-dependent regulation of anastomosis. Fungal Genet Biol 2016; 95:49-57. [PMID: 27531696 DOI: 10.1016/j.fgb.2016.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 08/10/2016] [Accepted: 08/12/2016] [Indexed: 11/25/2022]
Abstract
Heterokaryon formation is an essential step in asexual recombination in Fusarium oxysporum. Filamentous fungi have an elaborate nonself recognition machinery to prevent formation and proliferation of heterokaryotic cells, called heterokaryon incompatibility (HI). In F. oxysporum the regulation of this machinery is not well understood. In Neurospora crassa, Vib-1, a putative transcription factor of the p53-like Ndt80 family of transcription factors, has been identified as global regulator of HI. In this study we investigated the role of the F. oxysporum homolog of Vib-1, called Suf, in vegetative hyphal and conidial anastomosis tube (CAT) fusion and HI. We identified a novel function for an Ndt80 homolog as a nutrient-dependent regulator of anastomosis. Strains carrying the SUF deletion mutation display a hyper-fusion phenotype during vegetative growth as well as germling development. In addition, conidial paring of incompatible SUF deletion strains led to more heterokaryon formation, which is independent of suppression of HI. Our data provides further proof for the divergence in the functions of different members Ndt80 family. We propose that Ndt80 homologs mediate responses to nutrient quality and quantity, with specific responses varying between species.
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Affiliation(s)
- Shermineh Shahi
- Molecular Plant Pathology, University of Amsterdam, Amsterdam, The Netherlands
| | - Like Fokkens
- Molecular Plant Pathology, University of Amsterdam, Amsterdam, The Netherlands
| | - Petra M Houterman
- Molecular Plant Pathology, University of Amsterdam, Amsterdam, The Netherlands
| | - Martijn Rep
- Molecular Plant Pathology, University of Amsterdam, Amsterdam, The Netherlands.
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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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Kappel L, Gaderer R, Flipphi M, Seidl-Seiboth V. The N-acetylglucosamine catabolic gene cluster in Trichoderma reesei is controlled by the Ndt80-like transcription factor RON1. Mol Microbiol 2016; 99:640-57. [PMID: 26481444 PMCID: PMC4950302 DOI: 10.1111/mmi.13256] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2015] [Indexed: 11/28/2022]
Abstract
Chitin is an important structural constituent of fungal cell walls composed of N-acetylglucosamine (GlcNAc) monosaccharides, but catabolism of GlcNAc has not been studied in filamentous fungi so far. In the yeast Candida albicans, the genes encoding the three enzymes responsible for stepwise conversion of GlcNAc to fructose-6-phosphate are clustered. In this work, we analysed GlcNAc catabolism in ascomycete filamentous fungi and found that the respective genes are also clustered in these fungi. In contrast to C. albicans, the cluster often contains a gene for an Ndt80-like transcription factor, which we named RON1 (regulator of N-acetylglucosamine catabolism 1). Further, a gene for a glycoside hydrolase 3 protein related to bacterial N-acetylglucosaminidases can be found in the GlcNAc gene cluster in filamentous fungi. Functional analysis in Trichoderma reesei showed that the transcription factor RON1 is a key activator of the GlcNAc gene cluster and essential for GlcNAc catabolism. Furthermore, we present an evolutionary analysis of Ndt80-like proteins in Ascomycota. All GlcNAc cluster genes, as well as the GlcNAc transporter gene ngt1, and an additional transcriptional regulator gene, csp2, encoding the homolog of Neurospora crassa CSP2/GRHL, were functionally characterised by gene expression analysis and phenotypic characterisation of knockout strains in T. reesei.
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Affiliation(s)
- Lisa Kappel
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | - Romana Gaderer
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | - Michel Flipphi
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Verena Seidl-Seiboth
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
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42
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The Renaissance of Neurospora crassa: How a Classical Model System is Used for Applied Research. Fungal Biol 2016. [DOI: 10.1007/978-3-319-27951-0_3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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43
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Extreme Diversity in the Regulation of Ndt80-Like Transcription Factors in Fungi. G3-GENES GENOMES GENETICS 2015; 5:2783-92. [PMID: 26497142 PMCID: PMC4683649 DOI: 10.1534/g3.115.021378] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Saccharomyces cerevisiaeNdt80 protein is the founding member of a class of p53-like transcription factors that is known as the NDT80/PhoG-like DNA-binding family. The number of NDT80-like genes in different fungi is highly variable and their roles, which have been examined in only a few species, include regulation of meiosis, sexual development, biofilm formation, drug resistance, virulence, the response to nutrient stress and programmed cell death. The protein kinase Ime2 regulates the single NDT80 gene present in S. cerevisiae. In this study we used a genetic approach to investigate whether the Aspergillus nidulansIme2 homolog, ImeB, and/or protein kinases MpkC, PhoA and PhoB regulate the two NDT80-like genes (xprG and ndtA) in A. nidulans. Disruption of imeB, but not mpkC, phoA or phoB, led to increased extracellular protease activity and a defect in mycotoxin production similar to the xprG1 gain-of-function mutation. Quantitative RT-PCR showed that ImeB is a negative regulator of xprG expression and XprG is a negative regulator of xprG and ndtA expression. Thus, in contrast to Ime2, which is a positive regulator of NDT80 in S. cerevisiae, ImeB is a negative regulator as in Neurospora crassa. However, the ability of Ndt80 to autoregulate NDT80 is conserved in A. nidulans though the autoregulatory effect is negative rather than positive. Unlike N. crassa, a null mutation in imeB does not circumvent the requirement for XprG or NdtA. These results show that the regulatory activities of Ime2 and Ndt80-like proteins display an extraordinarily level of evolutionary flexibility.
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45
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Katz ME, Buckland R, Hunter CC, Todd RB. Distinct roles for the p53-like transcription factor XprG and autophagy genes in the response to starvation. Fungal Genet Biol 2015; 83:10-18. [DOI: 10.1016/j.fgb.2015.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 08/13/2015] [Accepted: 08/17/2015] [Indexed: 12/21/2022]
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46
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Montenegro-Montero A, Goity A, Larrondo LF. The bZIP Transcription Factor HAC-1 Is Involved in the Unfolded Protein Response and Is Necessary for Growth on Cellulose in Neurospora crassa. PLoS One 2015; 10:e0131415. [PMID: 26132395 PMCID: PMC4488935 DOI: 10.1371/journal.pone.0131415] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 06/02/2015] [Indexed: 12/15/2022] Open
Abstract
High protein secretion capacity in filamentous fungi requires an extremely efficient system for protein synthesis, folding and transport. When the folding capacity of the endoplasmic reticulum (ER) is exceeded, a pathway known as the unfolded protein response (UPR) is triggered, allowing cells to mitigate and cope with this stress. In yeast, this pathway relies on the transcription factor Hac1, which mediates the up-regulation of several genes required under these stressful conditions. In this work, we identified and characterized the ortholog of the yeast HAC1 gene in the filamentous fungus Neurospora crassa. We show that its mRNA undergoes an ER stress-dependent splicing reaction, which in N. crassa removes a 23 nt intron and leads to a change in the open reading frame. By disrupting the N. crassa hac-1 gene, we determined it to be crucial for activating UPR and for proper growth in the presence of ER stress-inducing chemical agents. Neurospora is naturally found growing on dead plant material, composed primarily by lignocellulose, and is a model organism for the study of plant cell wall deconstruction. Notably, we found that growth on cellulose, a substrate that requires secretion of numerous enzymes, imposes major demands on ER function and is dramatically impaired in the absence of hac-1, thus broadening the range of physiological functions of the UPR in filamentous fungi. Growth on hemicellulose however, another carbon source that necessitates the secretion of various enzymes for its deconstruction, is not impaired in the mutant nor is the amount of proteins secreted on this substrate, suggesting that secretion, as a whole, is unaltered in the absence of hac-1. The characterization of this signaling pathway in N. crassa will help in the study of plant cell wall deconstruction by fungi and its manipulation may result in important industrial biotechnological applications.
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Affiliation(s)
- Alejandro Montenegro-Montero
- Millennium Nucleus for Fungal Integrative and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alejandra Goity
- Millennium Nucleus for Fungal Integrative and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Luis F. Larrondo
- Millennium Nucleus for Fungal Integrative and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- * E-mail:
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Zhao J, Gladieux P, Hutchison E, Bueche J, Hall C, Perraudeau F, Glass NL. Identification of Allorecognition Loci in Neurospora crassa by Genomics and Evolutionary Approaches. Mol Biol Evol 2015; 32:2417-32. [PMID: 26025978 PMCID: PMC4540973 DOI: 10.1093/molbev/msv125] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Understanding the genetic and molecular bases of the ability to distinguish self from nonself (allorecognition) and mechanisms underlying evolution of allorecognition systems is an important endeavor for understanding cases where it becomes dysfunctional, such as in autoimmune disorders. In filamentous fungi, allorecognition can result in vegetative or heterokaryon incompatibility, which is a type of programmed cell death that occurs following fusion of genetically different cells. Allorecognition is genetically controlled by het loci, with coexpression of any combination of incompatible alleles triggering vegetative incompatibility. Herein, we identified, characterized, and inferred the evolutionary history of candidate het loci in the filamentous fungus Neurospora crassa. As characterized het loci encode proteins carrying an HET domain, we annotated HET domain genes in 25 isolates from a natural population along with the N. crassa reference genome using resequencing data. Because allorecognition systems can be affected by frequency-dependent selection favoring rare alleles (i.e., balancing selection), we mined resequencing data for HET domain loci whose alleles displayed elevated levels of variability, excess of intermediate frequency alleles, and deep gene genealogies. From these analyses, 34 HET domain loci were identified as likely to be under balancing selection. Using transformation, incompatibility assays and genetic analyses, we determined that one of these candidates functioned as a het locus (het-e). The het-e locus has three divergent allelic groups that showed signatures of positive selection, intra- and intergroup recombination, and trans-species polymorphism. Our findings represent a compelling case of balancing selection functioning on multiple alleles across multiple loci potentially involved in allorecognition.
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Affiliation(s)
- Jiuhai Zhao
- Plant and Microbial Biology Department, University of California, Berkeley
| | - Pierre Gladieux
- Plant and Microbial Biology Department, University of California, Berkeley INRA, UMR BGPI, TA A54/K, Montpellier, France; CIRAD, Montpellier, France
| | - Elizabeth Hutchison
- Plant and Microbial Biology Department, University of California, Berkeley Biology Department, 1 College Circle SUNY Geneseo, Geneseo, NY
| | - Joanna Bueche
- Plant and Microbial Biology Department, University of California, Berkeley
| | - Charles Hall
- Plant and Microbial Biology Department, University of California, Berkeley
| | - Fanny Perraudeau
- Plant and Microbial Biology Department, University of California, Berkeley Ecole Polytechnique, Palaiseau, France
| | - N Louise Glass
- Plant and Microbial Biology Department, University of California, Berkeley
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Niones JT, Takemoto D. VibA, a homologue of a transcription factor for fungal heterokaryon incompatibility, is involved in antifungal compound production in the plant-symbiotic fungus Epichloë festucae. EUKARYOTIC CELL 2015; 14:13-24. [PMID: 24906411 PMCID: PMC4279024 DOI: 10.1128/ec.00034-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 05/30/2014] [Indexed: 01/12/2023]
Abstract
Symbiotic association of epichloae endophytes (Epichloë/Neotyphodium species) with cool-season grasses of the subfamily Pooideae confers bioprotective benefits to the host plants against abiotic and biotic stresses. While the production of fungal bioprotective metabolites is a well-studied mechanism of host protection from insect herbivory, little is known about the antibiosis mechanism against grass pathogens by the mutualistic endophyte. In this study, an Epichloë festucae mutant defective in antimicrobial substance production was isolated by a mutagenesis approach. In an isolated mutant that had lost antifungal activity, the exogenous DNA fragment was integrated into the promoter region of the vibA gene, encoding a homologue of the transcription factor VIB-1. VIB-1 in Neurospora crassa is a regulator of genes essential in vegetative incompatibility and promotion of cell death. Here we show that deletion of the vibA gene severely affected the antifungal activity of the mutant against the test pathogen Drechslera erythrospila. Further analyses showed that overexpressing vibA enhanced the antifungal activity of the wild-type isolate against test pathogens. Transformants overexpressing vibA showed an inhibitory activity on test pathogens that the wild-type isolate could not. Moreover, overexpressing vibA in a nonantifungal E. festucae wild-type Fl1 isolate enabled the transformant to inhibit the mycelial and spore germination of D. erythrospila. These results demonstrate that enhanced expression of vibA is sufficient for a nonantifungal isolate to obtain antifungal activity, implicating the critical role of VibA in antifungal compound production by epichloae endophytes.
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Affiliation(s)
- Jennifer T Niones
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Daigo Takemoto
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
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Comeau AM, Dufour J, Bouvet GF, Jacobi V, Nigg M, Henrissat B, Laroche J, Levesque RC, Bernier L. Functional annotation of the Ophiostoma novo-ulmi genome: insights into the phytopathogenicity of the fungal agent of Dutch elm disease. Genome Biol Evol 2014; 7:410-30. [PMID: 25539722 PMCID: PMC4350166 DOI: 10.1093/gbe/evu281] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2014] [Indexed: 12/18/2022] Open
Abstract
The ascomycete fungus Ophiostoma novo-ulmi is responsible for the pandemic of Dutch elm disease that has been ravaging Europe and North America for 50 years. We proceeded to annotate the genome of the O. novo-ulmi strain H327 that was sequenced in 2012. The 31.784-Mb nuclear genome (50.1% GC) is organized into 8 chromosomes containing a total of 8,640 protein-coding genes that we validated with RNA sequencing analysis. Approximately 53% of these genes have their closest match to Grosmannia clavigera kw1407, followed by 36% in other close Sordariomycetes, 5% in other Pezizomycotina, and surprisingly few (5%) orphans. A relatively small portion (∼3.4%) of the genome is occupied by repeat sequences; however, the mechanism of repeat-induced point mutation appears active in this genome. Approximately 76% of the proteins could be assigned functions using Gene Ontology analysis; we identified 311 carbohydrate-active enzymes, 48 cytochrome P450s, and 1,731 proteins potentially involved in pathogen-host interaction, along with 7 clusters of fungal secondary metabolites. Complementary mating-type locus sequencing, mating tests, and culturing in the presence of elm terpenes were conducted. Our analysis identified a specific genetic arsenal impacting the sexual and vegetative growth, phytopathogenicity, and signaling/plant-defense-degradation relationship between O. novo-ulmi and its elm host and insect vectors.
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Affiliation(s)
- André M Comeau
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec, Canada Centre d'Étude de la Forêt (CEF), Université Laval, Québec, Québec, Canada Present address: Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Josée Dufour
- Centre d'Étude de la Forêt (CEF), Université Laval, Québec, Québec, Canada
| | - Guillaume F Bouvet
- Institut de Recherches Cliniques de Montréal (IRCM), Montréal, Québec, Canada
| | - Volker Jacobi
- Centre d'Étude de la Forêt (CEF), Université Laval, Québec, Québec, Canada
| | - Martha Nigg
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec, Canada Centre d'Étude de la Forêt (CEF), Université Laval, Québec, Québec, Canada
| | - Bernard Henrissat
- Centre National de la Recherche Scientifique (CNRS), UMR7257, Université Aix-Marseille, France Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Jérôme Laroche
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec, Canada
| | - Roger C Levesque
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec, Canada Département de Microbiologie-Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, Québec, Canada
| | - Louis Bernier
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec, Canada Centre d'Étude de la Forêt (CEF), Université Laval, Québec, Québec, Canada
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50
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Xiong Y, Sun J, Glass NL. VIB1, a link between glucose signaling and carbon catabolite repression, is essential for plant cell wall degradation by Neurospora crassa. PLoS Genet 2014; 10:e1004500. [PMID: 25144221 PMCID: PMC4140635 DOI: 10.1371/journal.pgen.1004500] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Accepted: 05/27/2014] [Indexed: 11/18/2022] Open
Abstract
Filamentous fungi that thrive on plant biomass are the major producers of hydrolytic enzymes used to decompose lignocellulose for biofuel production. Although induction of cellulases is regulated at the transcriptional level, how filamentous fungi sense and signal carbon-limited conditions to coordinate cell metabolism and regulate cellulolytic enzyme production is not well characterized. By screening a transcription factor deletion set in the filamentous fungus Neurospora crassa for mutants unable to grow on cellulosic materials, we identified a role for the transcription factor, VIB1, as essential for cellulose utilization. VIB1 does not directly regulate hydrolytic enzyme gene expression or function in cellulosic inducer signaling/processing, but affects the expression level of an essential regulator of hydrolytic enzyme genes, CLR2. Transcriptional profiling of a Δvib-1 mutant suggests that it has an improper expression of genes functioning in metabolism and energy and a deregulation of carbon catabolite repression (CCR). By characterizing new genes, we demonstrate that the transcription factor, COL26, is critical for intracellular glucose sensing/metabolism and plays a role in CCR by negatively regulating cre-1 expression. Deletion of the major player in CCR, cre-1, or a deletion of col-26, did not rescue the growth of Δvib-1 on cellulose. However, the synergistic effect of the Δcre-1; Δcol-26 mutations circumvented the requirement of VIB1 for cellulase gene expression, enzyme secretion and cellulose deconstruction. Our findings support a function of VIB1 in repressing both glucose signaling and CCR under carbon-limited conditions, thus enabling a proper cellular response for plant biomass deconstruction and utilization.
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Affiliation(s)
- Yi Xiong
- Plant and Microbial Biology Department and The Energy Biosciences Institute, The University of California, Berkeley, Berkeley, California, United States of America
| | - Jianping Sun
- Plant and Microbial Biology Department and The Energy Biosciences Institute, The University of California, Berkeley, Berkeley, California, United States of America
| | - N. Louise Glass
- Plant and Microbial Biology Department and The Energy Biosciences Institute, The University of California, Berkeley, Berkeley, California, United States of America
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