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Zhang YD, Ji XB, Zong J, Dai XF, Klosterman SJ, Subbarao KV, Zhang DD, Chen JY. Functional analysis of the mating type genes in Verticillium dahliae. BMC Biol 2024; 22:108. [PMID: 38714997 PMCID: PMC11077750 DOI: 10.1186/s12915-024-01900-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 04/22/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND Populations of the plant pathogenic fungus Verticillium dahliae display a complex and rich genetic diversity, yet the existence of sexual reproduction in the fungus remains contested. As pivotal genes, MAT genes play a crucial role in regulating cell differentiation, morphological development, and mating of compatible cells. However, the functions of the two mating type genes in V. dahliae, VdMAT1-1-1, and VdMAT1-2-1, remain poorly understood. RESULTS In this study, we confirmed that the MAT loci in V. dahliae are highly conserved, including both VdMAT1-1-1 and VdMAT1-2-1 which share high collinearity. The conserved core transcription factor encoded by the two MAT loci may facilitate the regulation of pheromone precursor and pheromone receptor genes by directly binding to their promoter regions. Additionally, peptide activity assays demonstrated that the signal peptide of the pheromone VdPpg1 possessed secretory activity, while VdPpg2, lacked a predicted signal peptide. Chemotactic growth assays revealed that V. dahliae senses and grows towards the pheromones FO-a and FO-α of Fusarium oxysporum, as well as towards VdPpg2 of V. dahliae, but not in response to VdPpg1. The findings herein also revealed that VdMAT1-1-1 and VdMAT1-2-1 regulate vegetative growth, carbon source utilization, and resistance to stressors in V. dahliae, while negatively regulating virulence. CONCLUSIONS These findings underscore the potential roles of VdMAT1-1-1 and VdMAT1-2-1 in sexual reproduction and confirm their involvement in various asexual processes of V. dahliae, offering novel insights into the functions of mating type genes in this species.
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Affiliation(s)
- Ya-Duo Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Xiao-Bin Ji
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Juan Zong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Xiao-Feng Dai
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Steven J Klosterman
- United States Department of Agriculture, Agricultural Research Service, Salinas, CA, USA
| | - Krishna V Subbarao
- Department of Plant Pathology, University of California, Davis, c/o United States Agricultural Research Station, Salinas, CA, USA.
| | - Dan-Dan Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
- Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji, 831100, China.
| | - Jie-Yin Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
- Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji, 831100, China.
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Ding M, Cao S, Xu D, Xia A, Wang Z, Wang W, Duan K, Wu C, Wang Q, Liang J, Wang D, Liu H, Xu JR, Jiang C. A non-pheromone GPCR is essential for meiosis and ascosporogenesis in the wheat scab fungus. Proc Natl Acad Sci U S A 2023; 120:e2313034120. [PMID: 37812726 PMCID: PMC10589705 DOI: 10.1073/pnas.2313034120] [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: 07/30/2023] [Accepted: 09/08/2023] [Indexed: 10/11/2023] Open
Abstract
Meiosis is essential for generating genetic diversity and sexual spores, but the regulation of meiosis and ascosporogenesis is not clear in filamentous fungi, in which dikaryotic and diploid cells formed inside fruiting bodies are not free living and independent of pheromones or pheromone receptors. In this study, Gia1, a non-pheromone GPCR (G protein-coupled receptor) with sexual-specific expression in Fusarium graminearum, is found to be essential for ascosporogenesis. The gia1 mutant was normal in perithecium development, crozier formation, and karyogamy but failed to undergo meiosis, which could be partially rescued by a dominant active mutation in GPA1 and activation of the Gpmk1 pathway. GIA1 orthologs have conserved functions in regulating meiosis and ascosporogenesis in Sordariomycetes. GIA1 has a paralog, GIP1, in F. graminearum and other Hypocreales species which is essential for perithecium formation. GIP1 differed from GIA1 in expression profiles and downstream signaling during sexual reproduction. Whereas the C-terminal tail and IR3 were important for intracellular signaling, the N-terminal region and EL3 of Gia1 were responsible for recognizing its ligand, which is likely a protein enriched in developing perithecia, particularly in the gia1 mutant. Taken together, these results showed that GIA1 encodes a non-pheromone GPCR that regulates the entry into meiosis and ascosporogenesis via the downstream Gpmk1 MAP kinase pathway in F. graminearum and other filamentous ascomycetes.
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Affiliation(s)
- Mingyu Ding
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Shulin Cao
- Institute of Plant Protection, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu210014, China
| | - Daiying Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Aliang Xia
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Zeyi Wang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN47907
| | - Wanshan Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Kaili Duan
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Chenyu Wu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Qinhu Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Jie Liang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Diwen Wang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN47907
| | - Huiquan Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
| | - Jin-Rong Xu
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN47907
| | - Cong Jiang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang, Shaanxi712100, China
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3
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Yao L, Kong Y, Yang W, Tian H, Meng X, Zhao X, Zhang R, Sun G, Rollins JA, Liang X. Two Putative Pheromone Receptors, but Not Their Cognate Pheromones, Regulate Female Fertility in the Atypical Mating Fungus Colletotrichum fructicola. PHYTOPATHOLOGY 2023; 113:1934-1945. [PMID: 37141175 DOI: 10.1094/phyto-11-22-0436-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Colletotrichum fungi are a group of damaging phytopathogens with atypical mating type loci (harboring only MAT1-2-1 but not MAT1-1-1) and complex sexual behaviors. Sex pheromones and their cognate G-protein-coupled receptors are conserved regulators of fungal mating. These genes, however, lose function frequently among Colletotrichum species, indicating a possibility that pheromone signaling is dispensable for Colletotrichum sexual reproduction. We have identified two putative pheromone-receptor pairs (PPG1:PRE2, PPG2:PRE1) in C. fructicola, a species that exhibits plus-to-minus mating type switching and plus-minus-mediated mating line development. Here, we report the generation and characterization of gene-deletion mutants for all four genes in both plus and minus strain backgrounds. Single-gene deletion of pre1 or pre2 had no effect on sexual development, whereas their double deletion caused self-sterility in both the plus and minus strains. Moreover, double deletion of pre1 and pre2 caused female sterility in plus-minus outcrossing. Double deletion of pre1 and pre2, however, did not inhibit perithecial differentiation or plus-minus-mediated enhancement of perithecial differentiation. Contrary to the results with pre1 and pre2, double deletion of ppg1 and ppg2 had no effect on sexual compatibility, development, or fecundity. We concluded that pre1 and pre2 coordinately regulate C. fructicola mating by recognizing novel signal molecule(s) distinct from canonical Ascomycota pheromones. The contrasting importance between pheromone receptors and their cognate pheromones highlights the complicated nature of sex regulation in Colletotrichum fungi.
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Affiliation(s)
- Liqiang Yao
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Yuanyuan Kong
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Wenrui Yang
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Huanhuan Tian
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Xiangchen Meng
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Xuemei Zhao
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Rong Zhang
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Guangyu Sun
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Jeffrey A Rollins
- Department of Plant Pathology, University of Florida, Gainesville, FL, U.S.A
| | - Xiaofei Liang
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
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Cabrera IE, Oza Y, Carrillo AJ, Collier LA, Wright SJ, Li L, Borkovich KA. Regulator of G Protein Signaling Proteins Control Growth, Development and Cellulase Production in Neurospora crassa. J Fungi (Basel) 2022; 8:jof8101076. [PMID: 36294641 PMCID: PMC9604755 DOI: 10.3390/jof8101076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/05/2022] [Accepted: 10/11/2022] [Indexed: 11/30/2022] Open
Abstract
Heterotrimeric (αβγ) G protein signaling pathways are critical environmental sensing systems found in eukaryotic cells. Exchange of GDP for GTP on the Gα subunit leads to its activation. In contrast, GTP hydrolysis on the Gα is accelerated by Regulator of G protein Signaling (RGS) proteins, resulting in a return to the GDP-bound, inactive state. Here, we analyzed growth, development and extracellular cellulase production in strains with knockout mutations in the seven identified RGS genes (rgs-1 to rgs-7) in the filamentous fungus, Neurospora crassa. We compared phenotypes to those of strains with either knockout mutations or expressing predicted constitutively activated, GTPase-deficient alleles for each of the three Gα subunit genes (gna-1Q204L, gna-2Q205L or gna-3Q208L). Our data revealed that six RGS mutants have taller aerial hyphae than wild type and all seven mutants exhibit reduced asexual sporulation, phenotypes shared with strains expressing the gna-1Q204L or gna-3Q208L allele. In contrast, Δrgs-1 and Δrgs-3 were the only RGS mutants with a slower growth rate phenotype, a defect in common with gna-1Q204L strains. With respect to female sexual development, Δrgs-1 possessed defects most similar to gna-3Q208L strains, while those of Δrgs-2 mutants resembled strains expressing the gna-1Q204L allele. Finally, we observed that four of the seven RGS mutants had significantly different extracellular cellulase levels relative to wild type. Of interest, the Δrgs-2 mutant had no detectable activity, similar to the gna-3Q208L strain. In contrast, the Δrgs-1 and Δrgs-4 mutants and gna-1Q204L and gna-2Q205L strains exhibited significantly higher cellulase activity than wild type. With the exception of sexual development, our results demonstrate the greatest number of genetic interactions between rgs-1 and gna-1 and rgs-2 and gna-3 in N. crassa.
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5
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Schmoll M, Hinterdobler W. Tools for adapting to a complex habitat: G-protein coupled receptors in Trichoderma. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 193:65-97. [PMID: 36357080 DOI: 10.1016/bs.pmbts.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Sensing the environment and interpretation of the received signals are crucial competences of living organisms in order to properly adapt to their habitat, succeed in competition and to reproduce. G-protein coupled receptors (GPCRs) are members of a large family of sensors for extracellular signals and represent the starting point of complex signaling cascades regulating a plethora of intracellular physiological processes and output pathways in fungi. In Trichoderma spp. current research involves a wide range of topics from enzyme production, light response and secondary metabolism to sexual and asexual development as well as biocontrol, all of which require delicate balancing of resources in response to the environmental challenges or biotechnological needs at hand, which are crucially impacted by the surroundings of the fungi and their intercellular signaling cascades triggering a precisely tailored response. In this review we summarize recent findings on sensing by GPCRs in Trichoderma, including the function of pheromone receptors, glucose sensing by CSG1 and CSG2, regulation of secondary metabolism by GPR8 and impacts on mycoparasitism by GPR1. Additionally, we provide an overview on structural determinants, posttranslational modifications and interactions for regulation, activation and signal termination of GPCRs in order to inspire future in depth analyses of their function and to understand previous regulatory outcomes of natural and biotechnological processes modulated or enabled by GPCRs.
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Affiliation(s)
- Monika Schmoll
- Department of Microbiology and Ecosystem Science, Division of Terrestrial Ecosystem Research, University of Vienna, Vienna, Austria.
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6
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Liu KX, Jia JQ, Chen N, Fu DD, Sun JY, Zhao JM, Li JY, Xiao SQ, Xue CS. Mating-Type Genes Control Sexual Reproduction, Conidial Germination, and Virulence in Cochliobolus lunatus. PHYTOPATHOLOGY 2022; 112:1055-1062. [PMID: 34738831 DOI: 10.1094/phyto-02-21-0063-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Cochliobolus lunatus (anamorph: Curvularia lunata) is a major pathogenic fungus that causes the Curvularia leaf spot of maize. ClMAT1-1-1 and ClMAT1-2-1, the C. lunatus orthologs of C. heterostrophus ChMAT1-1-1 and ChMAT1-2-1, were investigated in the present study to uncover their functions in C. lunatus. Southern blot analysis showed that these mating-type MAT genes exist in the C. lunatus genome as a single copy. ClMAT1-1-1 and ClMAT1-2-1 were knocked out and complemented to generate ΔClmat1-1-1 and ΔClmat1-2-1 and ΔClmat1-1-1-C and ΔClmat1-2-1-C, respectively. The mutant strains had defective sexual development and failed to produce pseudothecia. There were no significant differences in growth rate or conidia production between the mutant and wild-type strains. However, the aerial mycelia and mycelial dry weight of ΔClmat1-1-1 and ΔClmat1-2-1 were lower than those of wild type, suggesting that MAT genes affect asexual development. ClMAT genes were involved in the responses to cell wall integrity and osmotic adaptation. ΔClmat1-2-1 had a lower conidial germination rate than the wild-type strain CX-3. The virulence of ΔClmat1-2-1 and ΔClmat1-1-1 was also reduced compared with the wild-type. Complementary strains could restore all the phenotypes.
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Affiliation(s)
- K X Liu
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, P.R. China
| | - J Q Jia
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, P.R. China
| | - N Chen
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, P.R. China
| | - D D Fu
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, P.R. China
| | - J Y Sun
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, P.R. China
| | - J M Zhao
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, P.R. China
| | - J Y Li
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, P.R. China
| | - S Q Xiao
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, P.R. China
| | - C S Xue
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, P.R. China
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7
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Abstract
Fungi exhibit an enormous variety of morphologies, including yeast colonies, hyphal mycelia, and elaborate fruiting bodies. This diversity arises through a combination of polar growth, cell division, and cell fusion. Because fungal cells are nonmotile and surrounded by a protective cell wall that is essential for cell integrity, potential fusion partners must grow toward each other until they touch and then degrade the intervening cell walls without impacting cell integrity. Here, we review recent progress on understanding how fungi overcome these challenges. Extracellular chemoattractants, including small peptide pheromones, mediate communication between potential fusion partners, promoting the local activation of core cell polarity regulators to orient polar growth and cell wall degradation. However, in crowded environments, pheromone gradients can be complex and potentially confusing, raising the question of how cells can effectively find their partners. Recent findings suggest that the cell polarity circuit exhibits searching behavior that can respond to pheromone cues through a remarkably flexible and effective strategy called exploratory polarization.
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8
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Wilson AM, Wilken PM, Wingfield MJ, Wingfield BD. Genetic Networks That Govern Sexual Reproduction in the Pezizomycotina. Microbiol Mol Biol Rev 2021; 85:e0002021. [PMID: 34585983 PMCID: PMC8485983 DOI: 10.1128/mmbr.00020-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Sexual development in filamentous fungi is a complex process that relies on the precise control of and interaction between a variety of genetic networks and pathways. The mating-type (MAT) genes are the master regulators of this process and typically act as transcription factors, which control the expression of genes involved at all stages of the sexual cycle. In many fungi, the sexual cycle typically begins when the mating pheromones of one mating type are recognized by a compatible partner, followed by physical interaction and fertilization. Subsequently, highly specialized sexual structures are formed, within which the sexual spores develop after rounds of meiosis and mitosis. These spores are then released and germinate, forming new individuals that initiate new cycles of growth. This review provides an overview of the known genetic networks and pathways that are involved in each major stage of the sexual cycle in filamentous ascomycete fungi.
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Affiliation(s)
- Andi M. Wilson
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - P. Markus Wilken
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Michael J. Wingfield
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Brenda D. Wingfield
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
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Brun S, Kuo HC, Jeffree CE, Thomson DD, Read N. Courtship Ritual of Male and Female Nuclei during Fertilization in Neurospora crassa. Microbiol Spectr 2021; 9:e0033521. [PMID: 34612669 PMCID: PMC8509652 DOI: 10.1128/spectrum.00335-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/25/2021] [Indexed: 11/20/2022] Open
Abstract
Sexual reproduction is a key process influencing the evolution and adaptation of animals, plants, and many eukaryotic microorganisms, such as fungi. However, the sequential cell biology of fertilization and the associated nuclear dynamics after plasmogamy are poorly understood in filamentous fungi. Using histone-fluorescent parental isolates, we tracked male and female nuclei during fertilization in the model ascomycete Neurospora crassa using live-cell imaging. This study unravels the behavior of trichogyne resident female nuclei and the extraordinary manner in which male nuclei migrate up the trichogyne to the protoperithecium. Our observations raise new fundamental questions about the modus operandi of nucleus movements during sexual reproduction, male and female nuclear identity, guidance of nuclei within the trichogyne and, unexpectedly, the avoidance of "polyspermy" in fungi. The spatiotemporal dynamics of male nuclei within the trichogyne following plasmogamy are also described, where the speed and the deformation of male nuclei are of the most dramatic observed to date in a living organism. IMPORTANCE Using live-cell fluorescence imaging, for the first time we have observed live male and female nuclei during sexual reproduction in the model fungus Neurospora crassa. This study reveals the specific behavior of resident female nuclei within the trichogyne (the female organ) after fertilization and the extraordinary manner in which male nuclei migrate across the trichogyne toward their final destination, the protoperithecium, where karyogamy takes place. Importantly, the speed and deformation of male nuclei were found to be among the most dramatic ever observed in a living organism. Furthermore, we observed that entry of male nuclei into protoperithecia may block the entry of other male nuclei, suggesting that a process analogous to polyspermy avoidance could exist in fungi. Our live-cell imaging approach opens new opportunities for novel research on cell-signaling during sexual reproduction in fungi and, on a broader scale, nuclear dynamics in eukaryotes.
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Affiliation(s)
- Sylvain Brun
- Laboratoire Interdisciplinaire des Energies de Demain, CNRS UMR 8236, Université de Paris, Paris, France
| | - Hsiao-Che Kuo
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Chris E. Jeffree
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Darren D. Thomson
- Manchester Fungal Infection Group, Division of Infection, Immunity, and Respiratory Medicine, University of Manchester, Manchester, United Kingdom
| | - Nick Read
- Manchester Fungal Infection Group, Division of Infection, Immunity, and Respiratory Medicine, University of Manchester, Manchester, United Kingdom
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
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11
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Vangalis V, Knop M, Typas MA, Papaioannou IA. Establishment of conidial fusion in the asexual fungus Verticillium dahliae as a useful system for the study of non-sexual genetic interactions. Curr Genet 2021; 67:471-485. [PMID: 33582843 PMCID: PMC8139932 DOI: 10.1007/s00294-021-01157-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/11/2021] [Accepted: 01/22/2021] [Indexed: 02/07/2023]
Abstract
Cell-to-cell fusion is a fundamental biological process across the tree of life. In filamentous fungi, somatic fusion (or anastomosis) is required for the normal development of their syncytial hyphal networks, and it can initiate non-sexual genetic exchange processes, such as horizontal genetic transfer and the parasexual cycle. Although these could be important drivers of the evolution of asexual fungi, this remains a largely unexplored possibility due to the lack of suitable resources for their study in these puzzling organisms. We thus aimed at the characterization of cell fusion in the important asexual fungus Verticillium dahliae via Conidial Anastomosis Tubes (CATs), which can be useful for the analysis of parasexuality. We optimized appropriate procedures for their highly reproducible quantification and live-cell imaging, which were used to characterize their physiology and cell biology, and to start elucidating their underlying genetic machinery. Formation of CATs was shown to depend on growth conditions and require functional Fus3 and Slt2 MAP kinases, as well as the NADPH oxidase NoxA, whereas the GPCR Ste2 and the mating-type protein MAT1-2-1 were dispensable. We show that nuclei and other organelles can migrate through CATs, which often leads to the formation of transient dikaryons. Their nuclei have possible windows of opportunity for genetic interaction before degradation of one by a presumably homeostatic mechanism. We establish here CAT-mediated fusion in V. dahliae as an experimentally convenient system for the cytological analysis of fungal non-sexual genetic interactions. We expect that it will facilitate the dissection of sexual alternatives in asexual fungi.
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Affiliation(s)
- Vasileios Vangalis
- Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Michael Knop
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany.,German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Milton A Typas
- Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
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12
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Gao J, Xu X, Huang K, Liang Z. Fungal G-Protein-Coupled Receptors: A Promising Mediator of the Impact of Extracellular Signals on Biosynthesis of Ochratoxin A. Front Microbiol 2021; 12:631392. [PMID: 33643259 PMCID: PMC7907439 DOI: 10.3389/fmicb.2021.631392] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/21/2021] [Indexed: 01/17/2023] Open
Abstract
G-protein-coupled receptors (GPCRs) are transmembrane receptors involved in transducing signals from the external environment inside the cell, which enables fungi to coordinate cell transport, metabolism, and growth to promote their survival, reproduction, and virulence. There are 14 classes of GPCRs in fungi involved in sensing various ligands. In this paper, the synthesis of mycotoxins that are GPCR-mediated is discussed with respect to ligands, environmental stimuli, and intra-/interspecific communication. Despite their apparent importance in fungal biology, very little is known about the role of ochratoxin A (OTA) biosynthesis by Aspergillus ochraceus and the ligands that are involved. Fortunately, increasing evidence shows that the GPCR that involves the AF/ST (sterigmatocystin) pathway in fungi belongs to the same genus. Therefore, we speculate that GPCRs play an important role in a variety of environmental signals and downstream pathways in OTA biosynthesis. The verification of this inference will result in a more controllable GPCR target for control of fungal contamination in the future.
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Affiliation(s)
- Jing Gao
- Beijing Laboratory for Food Quality and Safety, Beijing, China
| | - Xinge Xu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Kunlun Huang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Zhihong Liang
- Beijing Laboratory for Food Quality and Safety, Beijing, China.,College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
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Luis JM, Carbone I, Payne GA, Bhatnagar D, Cary JW, Moore GG, Lebar MD, Wei Q, Mack B, Ojiambo PS. Characterization of morphological changes within stromata during sexual reproduction in Aspergillus flavus. Mycologia 2020; 112:908-920. [PMID: 32821029 DOI: 10.1080/00275514.2020.1800361] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Aspergillus flavus contaminates agricultural products worldwide with carcinogenic aflatoxins that pose a serious health risk to humans and animals. The fungus survives adverse environmental conditions through production of sclerotia. When fertilized by a compatible conidium of an opposite mating type, a sclerotium transforms into a stroma within which ascocarps, asci, and ascospores are formed. However, the transition from a sclerotium to a stroma during sexual reproduction in A. flavus is not well understood. Early events during the interaction between sexually compatible strains of A. flavus were visualized using conidia of a green fluorescent protein (GFP)-labeled MAT1-1 strain and sclerotia of an mCherry-labeled MAT1-2 strain. Both conidia and sclerotia of transformed strains germinated to produce hyphae within 24 h of incubation. Hyphal growth of these two strains produced what appeared to be a network of interlocking hyphal strands that were observed at the base of the mCherry-labeled sclerotia (i.e., region in contact with agar surface) after 72 h of incubation. At 5 wk following incubation, intracellular green-fluorescent hyphal strands were observed within the stromatal matrix of the mCherry-labeled strain. Scanning electron microscopy of stromata from a high- and low-fertility cross and unmated sclerotia was used to visualize the formation and development of sexual structures within the stromatal and sclerotial matrices, starting at the time of crossing and thereafter every 2 wk until 8 wk of incubation. Morphological differences between sclerotia and stromata became apparent at 4 wk of incubation. Internal hyphae and croziers were detected inside multiple ascocarps that developed within the stromatal matrix of the high-fertility cross but were not detected in the matrix of the low-fertility cross or the unmated sclerotia. At 6 to 8 wk of incubation, hyphal tips produced numerous asci, each containing one to eight ascospores that emerged out of an ascus following the breakdown of the ascus wall. These observations broaden our knowledge of early events during sexual reproduction and suggest that hyphae from the conidium-producing strain may be involved in the early stages of sexual reproduction in A. flavus. When combined with omics data, these findings could be useful in further exploration of the molecular and biochemical mechanisms underlying sexual reproduction in A. flavus.
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Affiliation(s)
- Jane Marian Luis
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University , Raleigh, NC 27695
| | - Ignazio Carbone
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University , Raleigh, NC 27695
| | - Gary A Payne
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University , Raleigh, NC 27695
| | - Deepak Bhatnagar
- Southern Regional Research Center, Agricultural Research Service , United States Department of Agriculture, New Orleans, Louisiana 70124
| | - Jeffrey W Cary
- Southern Regional Research Center, Agricultural Research Service , United States Department of Agriculture, New Orleans, Louisiana 70124
| | - Geromy G Moore
- Southern Regional Research Center, Agricultural Research Service , United States Department of Agriculture, New Orleans, Louisiana 70124
| | - Matthew D Lebar
- Southern Regional Research Center, Agricultural Research Service , United States Department of Agriculture, New Orleans, Louisiana 70124
| | - Qijian Wei
- Southern Regional Research Center, Agricultural Research Service , United States Department of Agriculture, New Orleans, Louisiana 70124
| | - Brian Mack
- Southern Regional Research Center, Agricultural Research Service , United States Department of Agriculture, New Orleans, Louisiana 70124
| | - Peter S Ojiambo
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University , Raleigh, NC 27695
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Genomic Analysis of Diverse Members of the Fungal Genus Monosporascus Reveals Novel Lineages, Unique Genome Content and a Potential Bacterial Associate. G3-GENES GENOMES GENETICS 2020; 10:2573-2583. [PMID: 32580939 PMCID: PMC7407469 DOI: 10.1534/g3.120.401489] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The genus Monosporascus represents an enigmatic group of fungi important in agriculture and widely distributed in natural arid ecosystems. Of the nine described species, two (M. cannonballus and M. eutypoides) are important pathogens on the roots of members of Cucurbitaceae in agricultural settings. The remaining seven species are capable of colonizing roots from a diverse host range without causing obvious disease symptoms. Recent molecular and culture studies have shown that members of the genus are nearly ubiquitous as root endophytes in arid environments of the Southwestern United States. Isolates have been obtained from apparently healthy roots of grasses, shrubs and herbaceous plants located in central New Mexico and other regions of the Southwest. Phylogenetic and genomic analyses reveal substantial diversity in these isolates. The New Mexico isolates include close relatives of M. cannonballus and M. ibericus, as well as isolates that represent previously unrecognized lineages. To explore evolutionary relationships within the genus and gain insights into potential ecological functions, we sequenced and assembled the genomes of three M. cannonballus isolates, one M. ibericus isolate, and six diverse New Mexico isolates. The assembled genomes were significantly larger than what is typical for the Sordariomycetes despite having predicted gene numbers similar to other members of the class. Differences in predicted genome content and organization were observed between endophytic and pathogenic lineages of Monosporascus. Several Monosporascus isolates appear to form associations with members of the bacterial genus Ralstonia (Burkholdariaceae).
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Tsai AYL, Oota M, Sawa S. Chemotactic Host-Finding Strategies of Plant Endoparasites and Endophytes. FRONTIERS IN PLANT SCIENCE 2020; 11:1167. [PMID: 32849722 PMCID: PMC7411241 DOI: 10.3389/fpls.2020.01167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 07/20/2020] [Indexed: 05/04/2023]
Abstract
Plants interact with microorganisms in the environment during all stages of their development and in most of their organs. These interactions can be either beneficial or detrimental for the plant and may be transient or long-term. In extreme cases, microorganisms become endoparastic or endophytic and permanently reside within a plant, while the host plant undergoes developmental reprogramming and produces new tissues or organs as a response to the invasion. Events at the cellular and molecular level following infection have been extensively described, however the mechanisms of how these microorganisms locate their plant hosts via chemotaxis remain largely unknown. In this review, we summarize recent findings concerning the signalling molecules that regulate chemotaxis of endoparasitic/endophytic bacteria, fungi, and nematodes. In particular, we will focus on the molecules secreted by plants that are most likely to act as guidance cues for microorganisms. These compounds are found in a wide range of plant species and show a variety of secondary effects. Interestingly, these compounds show different attraction potencies depending on the species of the invading organism, suggesting that cues perceived in the soil may be more complex than anticipated. However, what the cognate receptors are for these attractants, as well as the mechanism of how these attractants influence these organisms, remain important outstanding questions. Host-targeting marks the first step of plant-microorganism interactions, therefore understanding the signalling molecules involved in this step plays a key role in understanding these interactions as a whole.
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Sridhar PS, Trofimova D, Subramaniam R, González-Peña Fundora D, Foroud NA, Allingham JS, Loewen MC. Ste2 receptor-mediated chemotropism of Fusarium graminearum contributes to its pathogenicity against wheat. Sci Rep 2020; 10:10770. [PMID: 32612109 PMCID: PMC7329813 DOI: 10.1038/s41598-020-67597-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 06/08/2020] [Indexed: 01/14/2023] Open
Abstract
Fusarium Head Blight of wheat, caused by the filamentous fungus Fusarium graminearum, leads to devastating global food shortages and economic losses. While many studies have addressed the responses of both wheat and F. graminearum during their interaction, the possibility of fungal chemotropic sensing enabling pathogenicity remains unexplored. Based on recent findings linking the pheromone-sensing G-protein-coupled receptor Ste2 to host-directed chemotropism in Fusarium oxysporum, we investigated the role of the Ste2 receptor and its downstream signaling pathways in mediating chemotropism of F. graminearum. Interestingly, a chemotropic response of growing hyphae towards catalytically active Triticum aestivum ‘Roblin’ cultivar secreted peroxidases was detected, with deletion of STE2 in F. graminearum leading to loss of the observed response. At the same time, deletion of STE2 significantly decreased infection on germinating wheat coleoptiles, highlighting an association between Ste2, chemotropism and infection by F. graminearum. Further characterization revealed that the peroxidase-directed chemotropism is associated with stimulation of the fungal cell wall integrity mitogen-activated protein kinase signaling cascade. Altogether, this study demonstrates conservation of Ste2-mediated chemotropism by Fusarium species, and its important role in mediating pathogenicity.
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Affiliation(s)
- Pooja S Sridhar
- Department of Biomedical and Molecular Sciences, Queen's University, 18 Stuart St., Kingston, ON, K7L 3N6, Canada
| | - Daria Trofimova
- Department of Biomedical and Molecular Sciences, Queen's University, 18 Stuart St., Kingston, ON, K7L 3N6, Canada
| | | | | | - Nora A Foroud
- Agriculture and Agri-Food Canada, 5403, 1st Avenue South, Lethbridge, AB, T1J 4B1, Canada
| | - John S Allingham
- Department of Biomedical and Molecular Sciences, Queen's University, 18 Stuart St., Kingston, ON, K7L 3N6, Canada
| | - Michele C Loewen
- Department of Biomedical and Molecular Sciences, Queen's University, 18 Stuart St., Kingston, ON, K7L 3N6, Canada. .,National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada.
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17
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Garud A, Carrillo AJ, Collier LA, Ghosh A, Kim JD, Lopez-Lopez B, Ouyang S, Borkovich KA. Genetic relationships between the RACK1 homolog cpc-2 and heterotrimeric G protein subunit genes in Neurospora crassa. PLoS One 2019; 14:e0223334. [PMID: 31581262 PMCID: PMC6776386 DOI: 10.1371/journal.pone.0223334] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 09/18/2019] [Indexed: 11/19/2022] Open
Abstract
Receptor for Activated CKinase-1 (RACK1) is a multifunctional eukaryotic scaffolding protein with a seven WD repeat structure. Among their many cellular roles, RACK1 homologs have been shown to serve as alternative Gβ subunits during heterotrimeric G protein signaling in many systems. We investigated genetic interactions between the RACK1 homolog cpc-2, the previously characterized Gβ subunit gnb-1 and other G protein signaling components in the multicellular filamentous fungus Neurospora crassa. Results from cell fractionation studies and from fluorescent microscopy of a strain expressing a CPC-2-GFP fusion protein revealed that CPC-2 is a cytoplasmic protein. Genetic epistasis experiments between cpc-2, the three Gα genes (gna-1, gna-2 and gna-3) and gnb-1 demonstrated that cpc-2 is epistatic to gna-2 with regards to basal hyphae growth rate and aerial hyphae height, while deletion of cpc-2 mitigates the increased macroconidiation on solid medium observed in Δgnb-1 mutants. Δcpc-2 mutants inappropriately produce conidiophores during growth in submerged culture and mutational activation of gna-3 alleviates this defect. Δcpc-2 mutants are female-sterile and fertility could not be restored by mutational activation of any of the three Gα genes. With the exception of macroconidiation on solid medium, double mutants lacking cpc-2 and gnb-1 exhibited more severe defects for all phenotypic traits, supporting a largely synergistic relationship between GNB-1 and CPC-2 in N. crassa.
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Affiliation(s)
- Amruta Garud
- Department of Microbiology and Plant Pathology, University of California, Riverside, California, United States of America
| | - Alexander J. Carrillo
- Department of Microbiology and Plant Pathology, University of California, Riverside, California, United States of America
| | - Logan A. Collier
- Department of Microbiology and Plant Pathology, University of California, Riverside, California, United States of America
| | - Arit Ghosh
- Department of Microbiology and Plant Pathology, University of California, Riverside, California, United States of America
| | - James D. Kim
- Department of Microbiology and Plant Pathology, University of California, Riverside, California, United States of America
| | - Berenise Lopez-Lopez
- Department of Microbiology and Plant Pathology, University of California, Riverside, California, United States of America
| | - Shouqiang Ouyang
- Department of Microbiology and Plant Pathology, University of California, Riverside, California, United States of America
| | - Katherine A. Borkovich
- Department of Microbiology and Plant Pathology, University of California, Riverside, California, United States of America
- * E-mail:
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18
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Autocrine pheromone signalling regulates community behaviour in the fungal pathogen Fusarium oxysporum. Nat Microbiol 2019; 4:1443-1449. [PMID: 31133754 DOI: 10.1038/s41564-019-0456-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 04/12/2019] [Indexed: 11/09/2022]
Abstract
Autocrine self-signalling via secreted peptides and cognate receptors regulates cell development in eukaryotes and is conserved from protozoans to mammals1,2. In contrast, secreted peptides from higher fungi have been traditionally associated with paracrine non-self-signalling during sexual reproduction3. For example, cells of the model fungus Saccharomyces cerevisiae fall into two distinct mating types (MAT), which produce either a- or α-pheromone and the cognate receptors Ste2 or Ste3, respectively4. Inappropriate autocrine pheromone signalling (APS) during mating is prevented by downregulation of the self-pheromone receptor4,5 and by a-type cell-specific cleavage of α-pheromone through the protease Bar1 (refs. 6-8). While APS can be artificially induced by manipulation of the pheromone secrete-and-sense circuit7,9-11, its natural occurrence in ascomycete fungi has not been described. Here, we show that Fusarium oxysporum-a devastating plant pathogen that lacks a known sexual cycle12-co-expresses both pheromone-receptor pairs, resulting in autocrine regulation of developmental programmes other than mating. We found that unisexual populations of MAT1-1 cells (α-type idiomorphs13) secrete and sense both a- and α-pheromone, and that their perception requires the cognate receptors and conserved elements of the cell wall integrity mitogen-activated protein kinase cascade. We further show that F. oxysporum uses APS to regulate spore germination in a cell-density-dependent manner, whereby the α-Ste2 interaction leads to repression of conidial germination while the a-Ste3 interaction relieves repression. Our results reveal the existence of a regulatory function for peptide pheromones in the quorum-sensing-mediated control of fungal development.
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Lim JY, Park HM. Expression of sexual genes in Aspergillus fumigatus homogeneous culture produced by vegetative mass mating. J Microbiol 2019; 57:688-693. [PMID: 31079330 DOI: 10.1007/s12275-019-9094-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 03/15/2019] [Accepted: 03/15/2019] [Indexed: 12/19/2022]
Abstract
There are presently no studies on the genes for sexual development of Aspergillus fumigatus in situ using mating culture, primarily because of challenging experimental conditions that require a significantly long period of induction and produce developmentally heterogenous culture, harboring very few sexual organs. In order to overcome these challenges, we developed an efficient and convenient procedure called 'vegetative mass mating (VeM)' for study at a molecular level. The VeM method enabled production of a developmentally homogenous A. fumigatus culture, harboring many sexual organs in a plate within a short period of two weeks. Feasibility of the use of VeM for functional study of genes during A. fumigatus sexual development was evaluated by analyzing the transcription pattern of genes involved in pheromone signal transduction and regulation of sexual development. Here, we present for the first time, an in situ expression pattern of sexual genes during the mating process, induced by the VeM method, which will enable and promote the sexual development study of A. fumigatus at the molecular level.
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Affiliation(s)
- Joo-Yeon Lim
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Hee-Moon Park
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea.
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It's All in the Genes: The Regulatory Pathways of Sexual Reproduction in Filamentous Ascomycetes. Genes (Basel) 2019; 10:genes10050330. [PMID: 31052334 PMCID: PMC6562746 DOI: 10.3390/genes10050330] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/17/2019] [Accepted: 04/24/2019] [Indexed: 12/23/2022] Open
Abstract
Sexual reproduction in filamentous ascomycete fungi results in the production of highly specialized sexual tissues, which arise from relatively simple, vegetative mycelia. This conversion takes place after the recognition of and response to a variety of exogenous and endogenous cues, and relies on very strictly regulated gene, protein, and metabolite pathways. This makes studying sexual development in fungi an interesting tool in which to study gene-gene, gene-protein, and protein-metabolite interactions. This review provides an overview of some of the most important genes involved in this process; from those involved in the conversion of mycelia into sexually-competent tissue, to those involved in the development of the ascomata, the asci, and ultimately, the ascospores.
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Sensing and transduction of nutritional and chemical signals in filamentous fungi: Impact on cell development and secondary metabolites biosynthesis. Biotechnol Adv 2019; 37:107392. [PMID: 31034961 DOI: 10.1016/j.biotechadv.2019.04.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 04/22/2019] [Accepted: 04/25/2019] [Indexed: 11/23/2022]
Abstract
Filamentous fungi respond to hundreds of nutritional, chemical and environmental signals that affect expression of primary metabolism and biosynthesis of secondary metabolites. These signals are sensed at the membrane level by G protein coupled receptors (GPCRs). GPCRs contain usually seven transmembrane domains, an external amino terminal fragment that interacts with the ligand, and an internal carboxy terminal end interacting with the intracellular G protein. There is a great variety of GPCRs in filamentous fungi involved in sensing of sugars, amino acids, cellulose, cell-wall components, sex pheromones, oxylipins, calcium ions and other ligands. Mechanisms of signal transduction at the membrane level by GPCRs are discussed, including the internalization and compartmentalisation of these sensor proteins. We have identified and analysed the GPCRs in the genome of Penicillium chrysogenum and compared them with GPCRs of several other filamentous fungi. We have found 66 GPCRs classified into 14 classes, depending on the ligand recognized by these proteins, including most previously proposed classes of GPCRs. We have found 66 putative GPCRs, representatives of twelve of the fourteen previously proposed classes of GPCRs, depending on the ligand recognized by these proteins. A staggering fortytwo putative members of the new GPCR class XIV, the so-called Pth11 sensors of cellulosic material as reported for Neurospora crassa and some other fungi, were identified. Several GPCRs sensing sex pheromones, known in yeast and in several fungi, were also identified in P. chrysogenum, confirming the recent unravelling of the hidden sexual capacity of this species. Other sensing mechanisms do not involve GPCRs, including the two-component systems (HKRR), the HOG signalling system and the PalH mediated pH transduction sensor. GPCR sensor proteins transmit their signals by interacting with intracellular heterotrimeric G proteins, that are well known in several fungi, including P. chrysogenum. These G proteins are inactive in the GDP containing heterotrimeric state, and become active by nucleotide exchange, allowing the separation of the heterotrimeric protein in active Gα and Gβγ dimer subunits. The conversion of GTP in GDP is mediated by the endogenous GTPase activity of the G proteins. Downstream of the ligand interaction, the activated Gα protein and also the Gβ/Gγ dimer, transduce the signals through at least three different cascades: adenylate cyclase/cAMP, MAPK kinase, and phospholipase C mediated pathways.
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Fischer MS, Glass NL. Communicate and Fuse: How Filamentous Fungi Establish and Maintain an Interconnected Mycelial Network. Front Microbiol 2019; 10:619. [PMID: 31001214 PMCID: PMC6455062 DOI: 10.3389/fmicb.2019.00619] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 03/12/2019] [Indexed: 12/22/2022] Open
Abstract
Cell-to-cell communication and cell fusion are fundamental biological processes across the tree of life. Survival is often dependent upon being able to identify nearby individuals and respond appropriately. Communication between genetically different individuals allows for the identification of potential mating partners, symbionts, prey, or predators. In contrast, communication between genetically similar (or identical) individuals is important for mediating the development of multicellular organisms or for coordinating density-dependent behaviors (i.e., quorum sensing). This review describes the molecular and genetic mechanisms that mediate cell-to-cell communication and cell fusion between cells of Ascomycete filamentous fungi, with a focus on Neurospora crassa. Filamentous fungi exist as a multicellular, multinuclear network of hyphae, and communication-mediated cell fusion is an important aspect of colony development at each stage of the life cycle. Asexual spore germination occurs in a density-dependent manner. Germinated spores (germlings) avoid cells that are genetically different at specific loci, while chemotropically engaging with cells that share identity at these recognition loci. Germlings with genetic identity at recognition loci undergo cell fusion when in close proximity, a fitness attribute that contributes to more rapid colony establishment. Communication and cell fusion also occur between hyphae in a colony, which are important for reinforcing colony architecture and supporting the development of complex structures such as aerial hyphae and sexual reproductive structures. Over 70 genes have been identified in filamentous fungi (primarily N. crassa) that are involved in kind recognition, chemotropic interactions, and cell fusion. While the hypothetical signal(s) and receptor(s) remain to be described, a dynamic molecular signaling network that regulates cell-cell interactions has been revealed, including two conserved MAP-Kinase cascades, a conserved STRIPAK complex, transcription factors, a NOX complex involved in the generation of reactive oxygen species, cell-integrity sensors, actin, components of the secretory pathway, and several other proteins. Together these pathways facilitate the integration of extracellular signals, direct polarized growth, and initiate a transcriptional program that reinforces signaling and prepares cells for downstream processes, such as membrane merger, cell fusion and adaptation to heterokaryon formation.
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Affiliation(s)
- Monika S. Fischer
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley CA, United States
| | - N. Louise Glass
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley CA, United States
- Environmental Genomics and Systems Biology Division, The Lawrence Berkeley National Laboratory, Berkeley, CA, United States
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23
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The mating system of the Eucalyptus canker pathogen Chrysoporthe austroafricana and closely related species. Fungal Genet Biol 2019; 123:41-52. [DOI: 10.1016/j.fgb.2018.12.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 11/29/2018] [Accepted: 12/03/2018] [Indexed: 11/18/2022]
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Regulation of Cell-to-Cell Communication and Cell Wall Integrity by a Network of MAP Kinase Pathways and Transcription Factors in Neurospora crassa. Genetics 2018; 209:489-506. [PMID: 29678830 DOI: 10.1534/genetics.118.300904] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 04/18/2018] [Indexed: 11/18/2022] Open
Abstract
Maintenance of cell integrity and cell-to-cell communication are fundamental biological processes. Filamentous fungi, such as Neurospora crassa, depend on communication to locate compatible cells, coordinate cell fusion, and establish a robust hyphal network. Two MAP kinase (MAPK) pathways are essential for communication and cell fusion in N. crassa: the cell wall integrity/MAK-1 pathway and the MAK-2 (signal response) pathway. Previous studies have demonstrated several points of cross-talk between the MAK-1 and MAK-2 pathways, which is likely necessary for coordinating chemotropic growth toward an extracellular signal, and then mediating cell fusion. Canonical MAPK pathways begin with signal reception and end with a transcriptional response. Two transcription factors, ADV-1 and PP-1, are essential for communication and cell fusion. PP-1 is the conserved target of MAK-2, but it is unclear what targets ADV-1. We did RNA sequencing on Δadv-1, Δpp-1, and wild-type cells and found that ADV-1 and PP-1 have a shared regulon including many genes required for communication, cell fusion, growth, development, and stress response. We identified ADV-1 and PP-1 binding sites across the genome by adapting the in vitro method of DNA-affinity purification sequencing for N. crassa To elucidate the regulatory network, we misexpressed each transcription factor in each upstream MAPK deletion mutant. Misexpression of adv-1 was sufficient to fully suppress the phenotype of the Δpp-1 mutant and partially suppress the phenotype of the Δmak-1 mutant. Collectively, our data demonstrate that the MAK-1/ADV-1 and MAK-2/PP-1 pathways form a tight regulatory network that maintains cell integrity and mediates communication and cell fusion.
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25
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Wallen RM, Perlin MH. An Overview of the Function and Maintenance of Sexual Reproduction in Dikaryotic Fungi. Front Microbiol 2018; 9:503. [PMID: 29619017 PMCID: PMC5871698 DOI: 10.3389/fmicb.2018.00503] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 03/05/2018] [Indexed: 12/11/2022] Open
Abstract
Sexual reproduction likely evolved as protection from environmental stresses, specifically, to repair DNA damage, often via homologous recombination. In higher eukaryotes, meiosis and the production of gametes with allelic combinations different from parental type provides the side effect of increased genetic variation. In fungi it appears that while the maintenance of meiosis is paramount for success, outcrossing is not a driving force. In the subkingdom Dikarya, fungal members are characterized by existence of a dikaryon for extended stages within the life cycle. Such fungi possess functional or, in some cases, relictual, loci that govern sexual reproduction between members of their own species. All mating systems identified so far in the Dikarya employ a pheromone/receptor system for haploid organisms to recognize a compatible mating partner, although the paradigm in the Ascomycota, e.g., Saccharomyces cerevisiae, is that genes for the pheromone precursor and receptor are not found in the mating-type locus but rather are regulated by its products. Similarly, the mating systems in the Ascomycota are bipolar, with two non-allelic idiomorphs expressed in cells of opposite mating type. In contrast, for the Basidiomycota, both bipolar and tetrapolar mating systems have been well characterized; further, at least one locus directly encodes the pheromone precursor and the receptor for the pheromone of a different mating type, while a separate locus encodes proteins that may regulate the first locus and/or additional genes required for downstream events. Heterozygosity at both of two unlinked loci is required for cells to productively mate in tetrapolar systems, whereas in bipolar systems the two loci are tightly linked. Finally, a trade-off exists in wild fungal populations between sexual reproduction and the associated costs, with adverse conditions leading to mating. For fungal mammal pathogens, the products of sexual reproduction can be targets for the host immune system. The opposite appears true for phytopathogenic fungi, where mating and pathogenicity are inextricably linked. Here, we explore, compare, and contrast different strategies used among the Dikarya, both saprophytic and pathogenic fungi, and highlight differences between pathogens of mammals and pathogens of plants, providing context for selective pressures acting on this interesting group of fungi.
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Affiliation(s)
| | - Michael H. Perlin
- Department of Biology, University of Louisville, Louisville, KY, United States
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26
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Hadjivasiliou Z, Pomiankowski A. Gamete signalling underlies the evolution of mating types and their number. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0531. [PMID: 27619695 PMCID: PMC5031616 DOI: 10.1098/rstb.2015.0531] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2016] [Indexed: 01/02/2023] Open
Abstract
The gametes of unicellular eukaryotes are morphologically identical, but are nonetheless divided into distinct mating types. The number of mating types varies enormously and can reach several thousand, yet most species have only two. Why do morphologically identical gametes need to be differentiated into self-incompatible mating types, and why is two the most common number of mating types? In this work, we explore a neglected hypothesis that there is a need for asymmetric signalling interactions between mating partners. Our review shows that isogamous gametes always interact asymmetrically throughout sex and argue that this asymmetry is favoured because it enhances the efficiency of the mating process. We further develop a simple mathematical model that allows us to study the evolution of the number of mating types based on the strength of signalling interactions between gametes. Novel mating types have an advantage as they are compatible with all others and rarely meet their own type. But if existing mating types coevolve to have strong mutual interactions, this restricts the spread of novel types. Similarly, coevolution is likely to drive out less attractive mating types. These countervailing forces specify the number of mating types that are evolutionarily stable. This article is part of the themed issue ‘Weird sex: the underappreciated diversity of sexual reproduction’.
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Affiliation(s)
- Zena Hadjivasiliou
- Centre for Mathematics and Physics in the Life Sciences and Experimental Biology, University College London, Gower Street, London WC1E 6BT, UK Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Andrew Pomiankowski
- Centre for Mathematics and Physics in the Life Sciences and Experimental Biology, University College London, Gower Street, London WC1E 6BT, UK Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
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Mating-type genes of the anamorphic fungus Ulocladium botrytis affect both asexual sporulation and sexual reproduction. Sci Rep 2017; 7:7932. [PMID: 28801599 PMCID: PMC5554195 DOI: 10.1038/s41598-017-08471-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 07/13/2017] [Indexed: 11/23/2022] Open
Abstract
Ulocladium was thought to be a strictly asexual genus of filamentous fungi. However, Ulocladium strains were shown to possess both MAT1-1-1 and MAT1-2-1 genes as observed in homothallic filamentous Ascomycetes. Here, we demonstrate that the U. botrytis MAT genes play essential roles for controlling asexual traits (conidial size and number). Using reciprocal genetic transformation, we demonstrate that MAT genes from the related heterothallic species Cochliobolus heterostrophus can also influence U. botrytis colony growth, conidial number and size, and have a strong effect on the range of the number of septa/conidium. Moreover, U. botrytis MAT genes can also affect similar aspects of asexual reproduction when expressed in C. heterostrophus. Heterologous complementation using C. heterostrophus MAT genes shows that they have lost the ability to regulate sexual reproduction in U. botrytis, under the conditions we employed, while the reciprocal heterologous complementation demonstrates that U. botrytis MAT genes have the ability to partially induce sexual reproduction in C. heterostrophus. Thus, the genetic backgrounds of C. heterostrophus and U. botrytis play significant roles in determining the function of MAT genes on sexual reproduction in these two fungi species. These data further support the role of MAT genes in controlling asexual growth in filamentous Ascomycetes but also confirm that heterothallic and homothallic Dothideomycete fungi can be interconverted by the exchange of MAT genes.
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Sabnam N, Roy Barman S. WISH, a novel CFEM GPCR is indispensable for surface sensing, asexual and pathogenic differentiation in rice blast fungus. Fungal Genet Biol 2017; 105:37-51. [PMID: 28576657 DOI: 10.1016/j.fgb.2017.05.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 05/27/2017] [Accepted: 05/29/2017] [Indexed: 11/26/2022]
Abstract
We have selected and characterized a unique Conserved Fungal-specific Extra-cellular Membrane-spanning (CFEM) domain containing PTH11 like G-protein coupled receptor (GPCR), which is responsible for Water wettability, Infection, Surface sensing and Hyper-conidiation (WISH). The pathogenicity gene WISH is predicted to encode a novel seven transmembrane protein in the rice blast fungus, Magnaporthe oryzae, one of the deadliest pathogens of rice. We generated knockout mutants through a homologous recombination-based method to understand the function of the gene. These mutants are nonpathogenic due to a defect in sensing hydrophobic surface and appressorium differentiation. The mutant failed to undergo early events of pathogenesis, and appressorium development is diminished on inductive hydrophobic surface and was unable to penetrate susceptible rice leaves. The Δwish mutant did not develop any appressorium, suggesting that WISH protein is required for appressorium morphogenesis and is also involved in host surface recognition. We examined various aspects of pathogenesis and the results indicated involvement of WISH in preventing autolysis of vegetative hyphae, determining surface hydrophobicity and maintenance of cell-wall integrity. WISH gene from M. oryzae strain B157 complemented the Δwish mutant, indicating functional authenticity. Exogenous activation of cellular signaling failed to suppress the defects in Δwish mutants. These findings suggest that WISH GPCR senses diverse extracellular signals to play multiple roles and might have effects on PTH11 and MPG1 genes especially as an upstream effector of appressorium differentiation. It is for the first time that a typical GPCR containing seven transmembrane helices involved in the early events of plant pathogenesis of M. oryzae has been functionally characterized.
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Affiliation(s)
- Nazmiara Sabnam
- Department of Biotechnology, National Institute of Technology, Durgapur, India
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Bazafkan H, Dattenböck C, Stappler E, Beier S, Schmoll M. Interrelationships of VEL1 and ENV1 in light response and development in Trichoderma reesei. PLoS One 2017; 12:e0175946. [PMID: 28423024 PMCID: PMC5397039 DOI: 10.1371/journal.pone.0175946] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 04/03/2017] [Indexed: 12/25/2022] Open
Abstract
Sexual development is regulated by a complex regulatory mechanism in fungi. For Trichoderma reesei, the light response pathway was shown to impact sexual development, particularly through the photoreceptor ENVOY. Moreover, T. reesei communicates chemically with a potential mating partner in its vicinity, a response which is mediated by the velvet family protein VEL1 and its impact on secondary metabolism. We therefore studied the regulatory interactions of ENV1 and VEL1 with a focus on sexual development. Although individual mutants in both genes are female sterile under standard crossing conditions (light—dark cycles), an altered light regime enabled sexual development, which we found to be due to conditional female sterility of Δenv1, but not Δvel1. Phenotypes of growth and asexual sporulation as well as regulation of the peptide pheromone precursors of double mutants suggested that ENV1 and VEL1 balance positive and negative regulators of these functions. Additionally, VEL1 contributed to the strong deregulation of the pheromone system observed in env1 mutants. Female sterility of Δvel1 was rescued by deletion of env1 in darkness in MAT1-1, indicating a block of sexual development by ENV1 in darkness that is balanced by VEL1 in the wild-type. We conclude that ENV1 and VEL1 exert complementing functions in development of T. reesei. Our results further showed that the different developmental phenotypes of vel1/veA mutants in T. reesei and Aspergillus nidulans are not due to the presence or function of ENV1 in the VELVET regulatory pathway in T. reesei.
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Affiliation(s)
- Hoda Bazafkan
- AIT Austrian Institute of Technology GmbH, Department Health and Environment, Bioresources, Tulln, Austria
| | - Christoph Dattenböck
- AIT Austrian Institute of Technology GmbH, Department Health and Environment, Bioresources, Tulln, Austria
| | - Eva Stappler
- AIT Austrian Institute of Technology GmbH, Department Health and Environment, Bioresources, Tulln, Austria
| | - Sabrina Beier
- AIT Austrian Institute of Technology GmbH, Department Health and Environment, Bioresources, Tulln, Austria
| | - Monika Schmoll
- AIT Austrian Institute of Technology GmbH, Department Health and Environment, Bioresources, Tulln, Austria
- * E-mail:
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Barman A, Tamuli R. The pleiotropic vegetative and sexual development phenotypes of Neurospora crassa arise from double mutants of the calcium signaling genes plc-1, splA2, and cpe-1. Curr Genet 2017; 63:861-875. [PMID: 28265741 DOI: 10.1007/s00294-017-0682-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 01/30/2017] [Accepted: 02/07/2017] [Indexed: 11/25/2022]
Abstract
We investigated phenotypes of the double mutants of the calcium (Ca2+) signaling genes plc-1, splA2, and cpe-1 encoding for a phospholipase C1 (PLC-1), a secretory phospholipase A2 (sPLA2), and a Ca2+/H+ exchanger (CPE-1), respectively, to understand the cell functions regulated by their genetic interactions. Mutants lacking plc-1 and either splA2 or cpe-1 exhibited numerous defects including reduced colonial growth, stunted aerial hyphae, premature conidiation on plates with delayed germination, inappropriate conidiation in submerged culture, and lesser mycelial pigmentation. Moreover, the ∆plc-1; ∆splA2 and ∆plc-1; ∆cpe-1 double mutants were female-sterile when crossed with wild type as the male parent. In addition, ∆plc-1, ∆splA2, and ∆cpe-1 single mutants displayed higher carotenoid accumulation and an increased level of intracellular reactive oxygen species (ROS). Therefore, the pleiotropic phenotype of the double mutants of plc-1, splA2, and cpe-1 suggested that the genetic interaction of these genes plays a critical role for normal vegetative and sexual development in N. crassa.
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Affiliation(s)
- Ananya Barman
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781 039, India
| | - Ranjan Tamuli
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781 039, India.
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Fleißner A, Herzog S. Signal exchange and integration during self-fusion in filamentous fungi. Semin Cell Dev Biol 2016; 57:76-83. [DOI: 10.1016/j.semcdb.2016.03.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/06/2016] [Accepted: 03/22/2016] [Indexed: 11/16/2022]
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Braunsdorf C, Mailänder-Sánchez D, Schaller M. Fungal sensing of host environment. Cell Microbiol 2016; 18:1188-200. [DOI: 10.1111/cmi.12610] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/02/2016] [Accepted: 05/05/2016] [Indexed: 12/13/2022]
Affiliation(s)
- C. Braunsdorf
- Department of Dermatology; University Hospital Tübingen; Liebermeisterstr. 25 Tübingen Germany
| | - D. Mailänder-Sánchez
- Department of Internal Medicine I; University Hospital Tübingen; Otfried-Müller-Straße 10 72076 Tübingen
| | - M. Schaller
- Department of Dermatology; University Hospital Tübingen; Liebermeisterstr. 25 Tübingen Germany
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Turrà D, Nordzieke D, Vitale S, El Ghalid M, Di Pietro A. Hyphal chemotropism in fungal pathogenicity. Semin Cell Dev Biol 2016; 57:69-75. [PMID: 27150623 DOI: 10.1016/j.semcdb.2016.04.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/29/2016] [Accepted: 04/29/2016] [Indexed: 10/21/2022]
Abstract
The ability to grow as filamentous hyphae defines the lifestyle of fungi. Hyphae are exposed to a variety of chemical stimuli such as nutrients or signal molecules from mating partners and host organisms. How fungi sense and process this chemical information to steer hyphal growth is poorly understood. Saccharomyces cerevisiae and Neurospora crassa have served as genetic models for the identification of cellular components functioning in chemotropism. A recent study in the pathogen Fusarium oxysporum revealed distinct MAPK pathways governing hyphal growth towards nutrient sources and sex pheromones or plant signals, suggesting an unanticipated complexity of chemosensing during fungus-host interactions.
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Affiliation(s)
- David Turrà
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Daniela Nordzieke
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Stefania Vitale
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Mennat El Ghalid
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Antonio Di Pietro
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain.
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Lu Y, Xia Y, Luo F, Dong C, Wang C. Functional convergence and divergence of mating-type genes fulfilling in Cordyceps militaris. Fungal Genet Biol 2016; 88:35-43. [DOI: 10.1016/j.fgb.2016.01.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 01/20/2016] [Accepted: 01/22/2016] [Indexed: 10/22/2022]
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Turrà D, El Ghalid M, Rossi F, Di Pietro A. Fungal pathogen uses sex pheromone receptor for chemotropic sensing of host plant signals. Nature 2015; 527:521-4. [PMID: 26503056 DOI: 10.1038/nature15516] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 08/21/2015] [Indexed: 01/01/2023]
Abstract
For more than a century, fungal pathogens and symbionts have been known to orient hyphal growth towards chemical stimuli from the host plant. However, the nature of the plant signals as well as the mechanisms underlying the chemotropic response have remained elusive. Here we show that directed growth of the soil-inhabiting plant pathogen Fusarium oxysporum towards the roots of the host tomato (Solanum lycopersicum) is triggered by the catalytic activity of secreted class III peroxidases, a family of haem-containing enzymes present in all land plants. The chemotropic response requires conserved elements of the fungal cell integrity mitogen-activated protein kinase (MAPK) cascade and the seven-pass transmembrane protein Ste2, a functional homologue of the Saccharomyces cerevisiae sex pheromone α receptor. We further show that directed hyphal growth of F. oxysporum towards nutrient sources such as sugars and amino acids is governed by a functionally distinct MAPK cascade. These results reveal a potentially conserved chemotropic mechanism in root-colonizing fungi, and suggest a new function for the fungal pheromone-sensing machinery in locating plant hosts in a complex environment such as the soil.
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Affiliation(s)
- David Turrà
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Mennat El Ghalid
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Federico Rossi
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Antonio Di Pietro
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071 Córdoba, Spain
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Global Analysis of Predicted G Protein-Coupled Receptor Genes in the Filamentous Fungus, Neurospora crassa. G3-GENES GENOMES GENETICS 2015; 5:2729-43. [PMID: 26464358 PMCID: PMC4683645 DOI: 10.1534/g3.115.020974] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
G protein−coupled receptors (GPCRs) regulate facets of growth, development, and environmental sensing in eukaryotes, including filamentous fungi. The largest predicted GPCR class in these organisms is the Pth11-related, with members similar to a protein required for disease in the plant pathogen Magnaporthe oryzae. However, the Pth11-related class has not been functionally studied in any filamentous fungal species. Here, we analyze phenotypes in available mutants for 36 GPCR genes, including 20 Pth11-related, in the model filamentous fungus Neurospora crassa. We also investigate patterns of gene expression for all 43 predicted GPCR genes in available datasets. A total of 17 mutants (47%) possessed at least one growth or developmental phenotype. We identified 18 mutants (56%) with chemical sensitivity or nutritional phenotypes (11 uniquely), bringing the total number of mutants with at least one defect to 28 (78%), including 15 mutants (75%) in the Pth11-related class. Gene expression trends for GPCR genes correlated with the phenotypes observed for many mutants and also suggested overlapping functions for several groups of co-transcribed genes. Several members of the Pth11-related class have phenotypes and/or are differentially expressed on cellulose, suggesting a possible role for this gene family in plant cell wall sensing or utilization.
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Brown NA, Dos Reis TF, Ries LNA, Caldana C, Mah JH, Yu JH, Macdonald JM, Goldman GH. G-protein coupled receptor-mediated nutrient sensing and developmental control in Aspergillus nidulans. Mol Microbiol 2015; 98:420-39. [PMID: 26179439 DOI: 10.1111/mmi.13135] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2015] [Indexed: 12/31/2022]
Abstract
Nutrient sensing and utilisation are fundamental for all life forms. As heterotrophs, fungi have evolved a diverse range of mechanisms for sensing and taking up various nutrients. Despite its importance, only a limited number of nutrient receptors and their corresponding ligands have been identified in fungi. G-protein coupled receptors (GPCRs) are the largest family of transmembrane receptors. The Aspergillus nidulans genome encodes 16 putative GPCRs, but only a few have been functionally characterised. Our previous study showed the increased expression of an uncharacterised putative GPCR, gprH, during carbon starvation. GprH appears conserved throughout numerous filamentous fungi. Here, we reveal that GprH is a putative receptor involved in glucose and tryptophan sensing. The absence of GprH results in a reduction in cAMP levels and PKA activity upon adding glucose or tryptophan to starved cells. GprH is pre-formed in conidia and is increasingly active during carbon starvation, where it plays a role in glucose uptake and the recovery of hyphal growth. GprH also represses sexual development under conditions favouring sexual fruiting and during carbon starvation in submerged cultures. In summary, the GprH nutrient-sensing system functions upstream of the cAMP-PKA pathway, influences primary metabolism and hyphal growth, while represses sexual development in A. nidulans.
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Affiliation(s)
- Neil Andrew Brown
- Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
| | - Thaila Fernanda Dos Reis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | | | - Camila Caldana
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol - CTBE, Campinas, São Paulo, Brazil.,Max Planck Partnergroup at CTBE/CNPEM, Campinas, São Paulo, Brazil
| | - Jae-Hyung Mah
- Department of Food and Biotechnology, Korea University, Sejong, South Korea
| | - Jae-Hyuk Yu
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | - Jeffrey M Macdonald
- UNC Metabolomic Facility, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Gustavo Henrique Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil.,Laboratório Nacional de Ciência e Tecnologia do Bioetanol - CTBE, Campinas, São Paulo, Brazil
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Metabolic Impacts of Using Nitrogen and Copper-Regulated Promoters to Regulate Gene Expression in Neurospora crassa. G3-GENES GENOMES GENETICS 2015; 5:1899-908. [PMID: 26194204 PMCID: PMC4555226 DOI: 10.1534/g3.115.020073] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The filamentous fungus Neurospora crassa is a long-studied eukaryotic microbial system amenable to heterologous expression of native and foreign proteins. However, relatively few highly tunable promoters have been developed for this species. In this study, we compare the tcu-1 and nit-6 promoters for controlled expression of a GFP reporter gene in N. crassa. Although the copper-regulated tcu-1 has been previously characterized, this is the first investigation exploring nitrogen-controlled nit-6 for expression of heterologous genes in N. crassa. We determined that fragments corresponding to 1.5-kb fragments upstream of the tcu-1 and nit-6 open reading frames are needed for optimal repression and expression of GFP mRNA and protein. nit-6 was repressed using concentrations of glutamine from 2 to 20 mM and induced in medium containing 0.5–20 mM nitrate as the nitrogen source. Highest levels of expression were achieved within 3 hr of induction for each promoter and GFP mRNA could not be detected within 1 hr after transfer to repressing conditions using the nit-6 promoter. We also performed metabolic profiling experiments using proton NMR to identify changes in metabolite levels under inducing and repressing conditions for each promoter. The results demonstrate that conditions used to regulate tcu-1 do not significantly change the primary metabolome and that the differences between inducing and repressing conditions for nit-6 can be accounted for by growth under nitrate or glutamine as a nitrogen source. Our findings demonstrate that nit-6 is a tunable promoter that joins tcu-1 as a choice for regulation of gene expression in N. crassa.
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Bazafkan H, Dattenböck C, Böhmdorfer S, Tisch D, Stappler E, Schmoll M. Mating type-dependent partner sensing as mediated by VEL1 in Trichoderma reesei. Mol Microbiol 2015; 96:1103-18. [PMID: 25757597 PMCID: PMC4949666 DOI: 10.1111/mmi.12993] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2015] [Indexed: 12/21/2022]
Abstract
Sexual development in the filamentous model ascomycete Trichoderma reesei (syn. Hypocrea jecorina) was described only a few years ago. In this study, we show a novel role for VELVET in fungi, which links light response, development and secondary metabolism. Vel1 is required for mating in darkness, normal growth and conidiation. In light, vel1 was dispensable for male fertility but essential for female fertility in both mating types. VEL1 impacted regulation of the pheromone system (hpr1, hpr2, hpp1, ppg1) in a mating type‐dependent manner and depending on the mating partner of a given strain. These partner effects only occurred for hpp1 and hpr2, the pheromone precursor and receptor genes associated with the MAT1‐2 mating type and for the mating type gene mat1‐2‐1. Analysis of secondary metabolite patterns secreted by wild type and mutants under asexual and sexual conditions revealed that even in the wild type, the patterns change upon encounter of a mating partner, with again distinct differences for wild type and vel1 mutants. Hence, T. reesei applies a language of pheromones and secondary metabolites to communicate with mating partners and that this communication is at least in part mediated by VEL1.
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Affiliation(s)
- Hoda Bazafkan
- Department Health and Environment, AIT Austrian Institute of Technology GmbH, Bioresources, Konrad-Lorenz Strasse 24, Tulln, 3430, Austria
| | - Christoph Dattenböck
- Department Health and Environment, AIT Austrian Institute of Technology GmbH, Bioresources, Konrad-Lorenz Strasse 24, Tulln, 3430, Austria
| | - Stefan Böhmdorfer
- University of Natural Resources and Life Sciences Vienna, Department of Chemistry, Division of Chemistry of Renewable Resources, Konrad-Lorenz-Straße 24, Tulln, 3430, Austria
| | - Doris Tisch
- Research Area Molecular Biotechnology, Vienna University of Technology, Gumpendorfer Straße 1a, Wien, 1060, Austria
| | - Eva Stappler
- Department Health and Environment, AIT Austrian Institute of Technology GmbH, Bioresources, Konrad-Lorenz Strasse 24, Tulln, 3430, Austria
| | - Monika Schmoll
- Department Health and Environment, AIT Austrian Institute of Technology GmbH, Bioresources, Konrad-Lorenz Strasse 24, Tulln, 3430, Austria
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Chinnici JL, Fu C, Caccamise LM, Arnold JW, Free SJ. Neurospora crassa female development requires the PACC and other signal transduction pathways, transcription factors, chromatin remodeling, cell-to-cell fusion, and autophagy. PLoS One 2014; 9:e110603. [PMID: 25333968 PMCID: PMC4204872 DOI: 10.1371/journal.pone.0110603] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 09/16/2014] [Indexed: 01/01/2023] Open
Abstract
Using a screening protocol we have identified 68 genes that are required for female development in the filamentous fungus Neurospora crassa. We find that we can divide these genes into five general groups: 1) Genes encoding components of the PACC signal transduction pathway, 2) Other signal transduction pathway genes, including genes from the three N. crassa MAP kinase pathways, 3) Transcriptional factor genes, 4) Autophagy genes, and 5) Other miscellaneous genes. Complementation and RIP studies verified that these genes are needed for the formation of the female mating structure, the protoperithecium, and for the maturation of a fertilized protoperithecium into a perithecium. Perithecia grafting experiments demonstrate that the autophagy genes and the cell-to-cell fusion genes (the MAK-1 and MAK-2 pathway genes) are needed for the mobilization and movement of nutrients from an established vegetative hyphal network into the developing protoperithecium. Deletion mutants for the PACC pathway genes palA, palB, palC, palF, palH, and pacC were found to be defective in two aspects of female development. First, they were unable to initiate female development on synthetic crossing medium. However, they could form protoperithecia when grown on cellophane, on corn meal agar, or in response to the presence of nearby perithecia. Second, fertilized perithecia from PACC pathway mutants were unable to produce asci and complete female development. Protein localization experiments with a GFP-tagged PALA construct showed that PALA was localized in a peripheral punctate pattern, consistent with a signaling center associated with the ESCRT complex. The N. crassa PACC signal transduction pathway appears to be similar to the PacC/Rim101 pathway previously characterized in Aspergillus nidulans and Saccharomyces cerevisiae. In N. crassa the pathway plays a key role in regulating female development.
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Affiliation(s)
- Jennifer L. Chinnici
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
| | - Ci Fu
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
| | - Lauren M. Caccamise
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
| | - Jason W. Arnold
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
| | - Stephen J. Free
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
- * E-mail:
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Kim KH, Kang YM, Im CH, Ali A, Kim SY, Je HJ, Kim MK, Rho HS, Lee HS, Kong WS, Ryu JS. Identification and functional analysis of pheromone and receptor genes in the B3 mating locus of Pleurotus eryngii. PLoS One 2014; 9:e104693. [PMID: 25133513 PMCID: PMC4136793 DOI: 10.1371/journal.pone.0104693] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 07/10/2014] [Indexed: 11/19/2022] Open
Abstract
Pleurotus eryngii has recently become a major cultivated mushroom; it uses tetrapolar heterothallism as a part of its reproductive process. Sexual development progresses only when the A and B mating types are compatible. Such mating incompatibility occasionally limits the efficiency of breeding programs in which crossing within loci-shared strains or backcrossing strategies are employed. Therefore, understanding the mating system in edible mushroom fungi will help provide a short cut in the development of new strains. We isolated and identified pheromone and receptor genes in the B3 locus of P. eryngii and performed a functional analysis of the genes in the mating process by transformation. A genomic DNA library was constructed to map the entire mating-type locus. The B3 locus was found to contain four pheromone precursor genes and four receptor genes. Remarkably, receptor PESTE3.3.1 has just 34 amino acid residues in its C-terminal cytoplasmic region; therefore, it seems likely to be a receptor-like gene. Real-time quantitative RT-PCR (real-time qRT-PCR) revealed that most pheromone and receptor genes showed significantly higher expression in monokaryotic cells than dikaryotic cells. The pheromone genes PEphb3.1 and PEphb3.3 and the receptor gene PESTE3.3.1 were transformed into P5 (A3B4). The transformants were mated with a tester strain (A4B4), and the progeny showed clamp connections and a normal fruiting body, which indicates the proposed role of these genes in mating and fruiting processes. This result also confirms that PESTE3.3.1 is a receptor gene. In this study, we identified pheromone and receptor genes in the B3 locus of P. eryngii and found that some of those genes appear to play a role in the mating and fruiting processes. These results might help elucidate the mechanism of fruiting differentiation and improve breeding efficiency.
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Affiliation(s)
- Kyung-Hee Kim
- Environment-friendly Research Division, Gyeongsangnam-do Agricultural Research and Extension Services, Jinju, Republic of Korea
| | - Young Min Kang
- Environment-friendly Research Division, Gyeongsangnam-do Agricultural Research and Extension Services, Jinju, Republic of Korea
- Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon, Republic of Korea
| | - Chak Han Im
- Environment-friendly Research Division, Gyeongsangnam-do Agricultural Research and Extension Services, Jinju, Republic of Korea
| | - Asjad Ali
- Environment-friendly Research Division, Gyeongsangnam-do Agricultural Research and Extension Services, Jinju, Republic of Korea
| | - Sun Young Kim
- Environment-friendly Research Division, Gyeongsangnam-do Agricultural Research and Extension Services, Jinju, Republic of Korea
| | - Hee-Jeong Je
- Environment-friendly Research Division, Gyeongsangnam-do Agricultural Research and Extension Services, Jinju, Republic of Korea
| | - Min-Keun Kim
- Environment-friendly Research Division, Gyeongsangnam-do Agricultural Research and Extension Services, Jinju, Republic of Korea
| | - Hyun Su Rho
- Department of Microbiology, Gyeongsang National University, Jinju, Republic of Korea
| | - Hyun Sook Lee
- Department of Microbiology, Gyeongsang National University, Jinju, Republic of Korea
| | - Won-Sik Kong
- Mushroom Research Division, National Institute of Horticultural and Herbal Science, Rural Development Administration, Eumsung, Republic of Korea
| | - Jae-San Ryu
- Environment-friendly Research Division, Gyeongsangnam-do Agricultural Research and Extension Services, Jinju, Republic of Korea
- * E-mail:
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Strandberg R, Tzelepis G, Johannesson H, Karlsson M. Coexistence and expression profiles of two alternative splice variants of the pheromone receptor gene pre‑1 in Neurospora crassa. Arch Microbiol 2013; 195:773-80. [PMID: 24022114 DOI: 10.1007/s00203-013-0923-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/22/2013] [Accepted: 08/29/2013] [Indexed: 10/26/2022]
Abstract
In this study, we show that two splice variants of the pheromone receptor gene (pre-1) transcript coexist in vegetative and reproductive tissues of the filamentous ascomycete fungus Neurospora crassa. The two splice variants differ by intron retention of the last intron, which is predicted to result in a premature stop codon and loss of 322 amino acids in the C-terminal cytosolic region of PRE-1. Using quantitative PCR, we show that expression of the variants is influenced by mating type (mat), with a higher proportion of intron-spliced transcripts in a mat A strain and a higher proportion of the intron-retained variant in a mat a strain. The intron-retained PRE-1 variant is predicted to lack 6 ubiquitination sites that may influence receptor function. In conclusion, N. crassa produce two pre-1 splice variants that display different transcription profiles.
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Global gene expression and focused knockout analysis reveals genes associated with fungal fruiting body development in Neurospora crassa. EUKARYOTIC CELL 2013; 13:154-69. [PMID: 24243796 DOI: 10.1128/ec.00248-13] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Fungi can serve as highly tractable models for understanding genetic basis of sexual development in multicellular organisms. Applying a reverse-genetic approach to advance such a model, we used random and multitargeted primers to assay gene expression across perithecial development in Neurospora crassa. We found that functionally unclassified proteins accounted for most upregulated genes, whereas downregulated genes were enriched for diverse functions. Moreover, genes associated with developmental traits exhibited stage-specific peaks of expression. Expression increased significantly across sexual development for mating type gene mat a-1 and for mat A-1 specific pheromone precursor ccg-4. In addition, expression of a gene encoding a protein similar to zinc finger, stc1, was highly upregulated early in perithecial development, and a strain with a knockout of this gene exhibited arrest at the same developmental stage. A similar expression pattern was observed for genes in RNA silencing and signaling pathways, and strains with knockouts of these genes were also arrested at stages of perithecial development that paralleled their peak in expression. The observed stage specificity allowed us to correlate expression upregulation and developmental progression and to identify regulators of sexual development. Bayesian networks inferred from our expression data revealed previously known and new putative interactions between RNA silencing genes and pathways. Overall, our analysis provides a fine-scale transcriptomic landscape and novel inferences regarding the control of the multistage development process of sexual crossing and fruiting body development in N. crassa.
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Mating type genes and cryptic sexuality as tools for genetically manipulating industrial molds. Appl Microbiol Biotechnol 2013; 97:9609-20. [DOI: 10.1007/s00253-013-5268-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 09/12/2013] [Accepted: 09/14/2013] [Indexed: 01/11/2023]
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Abstract
Vegetative fusion is essential for the development of an interconnected colony in many filamentous fungi. In the ascomycete fungus Neurospora crassa, vegetative fusion occurs between germinated conidia (germlings) via specialized structures termed "conidial anastomosis tubes" (CATs) and between hyphae within a mature colony. In N. crassa, both CAT and hyphal fusion are under the regulation of a conserved MAP kinase cascade (NRC1, MEK2, and MAK2). Here we show that the predicted downstream target of the MAK2 kinase pathway, a Ste12-like transcription factor known as PP1, regulates elements required for CAT and hyphal fusion. The PP1 regulatory network was revealed by expression profiling of wild type and the Δpp-1 mutant during conidial germination and colony establishment. To identify targets required for cell fusion more specifically, expression-profiling differences were assessed via inhibition of MAK2 kinase activity during chemotropic interactions and cell fusion. These approaches led to the identification of new targets of the cell fusion pathway that, when mutated, showed alterations in chemotropic signaling and cell fusion. In particular, conidial germlings carrying a deletion of NCU04732 (Δham-11) failed to show chemotropic interactions and cell fusion. However, signaling (as shown by oscillation of MAK2 and SO to CAT tips), chemotropism, and cell fusion were restored in Δham-11 germlings when matched with wild-type partner germlings. These data reveal novel insights into the complex process of self-signaling, germling fusion, and colony establishment in filamentous fungi.
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Ying SH, Feng MG, Keyhani NO. A carbon responsive G-protein coupled receptor modulates broad developmental and genetic networks in the entomopathogenic fungus,Beauveria bassiana. Environ Microbiol 2013; 15:2902-21. [DOI: 10.1111/1462-2920.12169] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 05/23/2013] [Accepted: 05/25/2013] [Indexed: 11/27/2022]
Affiliation(s)
| | - Ming-Guang Feng
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou; 310058; China
| | - Nemat O. Keyhani
- Department of Microbiology and Cell Science; University of Florida; Gainesville; FL; 32611; USA
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Gruber S, Omann M, Zeilinger S. Comparative analysis of the repertoire of G protein-coupled receptors of three species of the fungal genus Trichoderma. BMC Microbiol 2013; 13:108. [PMID: 23679152 PMCID: PMC3664084 DOI: 10.1186/1471-2180-13-108] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 05/07/2013] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Eukaryotic organisms employ cell surface receptors such as the seven-transmembrane G protein-coupled receptors (GPCRs) as sensors to connect to the environment. GPCRs react to a variety of extracellular cues and are considered to play central roles in the signal transduction in fungi. Several species of the filamentous ascomycete Trichoderma are potent mycoparasites, i.e. can attack and parasitize other fungi, which turns them into successful bio-fungicides for the protection of plants against fungal phytopathogens. The identification and characterization of GPCRs will provide insights into how Trichoderma communicates with its environment and senses the presence of host fungi. RESULTS We mined the recently published genomes of the two mycoparasitic biocontrol agents Trichoderma atroviride and Trichoderma virens and compared the identified GPCR-like proteins to those of the saprophyte Trichoderma reesei. Phylogenetic analyses resulted in 14 classes and revealed differences not only among the three Trichoderma species but also between Trichoderma and other fungi. The class comprising proteins of the PAQR family was significantly expanded both in Trichoderma compared to other fungi as well as in the two mycoparasites compared to T. reesei. Expression analysis of the PAQR-encoding genes of the three Trichoderma species revealed that all except one were actually transcribed. Furthermore, the class of receptors with a DUF300 domain was expanded in T. atroviride, and T. virens showed an expansion of PTH11-like receptors compared to T. atroviride and T. reesei. CONCLUSIONS Comparative genome analyses of three Trichoderma species revealed a great diversity of putative GPCRs with genus- and species- specific differences. The expansion of certain classes in the mycoparasites T. atroviride and T. virens is likely to reflect the capability of these fungi to establish various ecological niches and interactions with other organisms such as fungi and plants. These GPCRs consequently represent interesting candidates for future research on the mechanisms underlying mycoparasitism and biocontrol.
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Affiliation(s)
- Sabine Gruber
- Research Area Molecular Biotechnology and Microbiology, Institute of Chemical Engineering, Vienna University of Technology, Gumpendorferstrasse 1a, Wien, Austria
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Nieuwenhuis BPS, Aanen DK. Sexual selection in fungi. J Evol Biol 2013; 25:2397-411. [PMID: 23163326 DOI: 10.1111/jeb.12017] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Revised: 09/07/2012] [Accepted: 09/07/2012] [Indexed: 12/14/2022]
Abstract
The significance of sexual selection, the component of natural selection associated with variation in mating success, is well established for the evolution of animals and plants, but not for the evolution of fungi. Even though fungi do not have separate sexes, most filamentous fungi mate in a hermaphroditic fashion, with distinct sex roles, that is, investment in large gametes (female role) and fertilization by other small gametes (male role). Fungi compete to fertilize, analogous to 'male-male' competition, whereas they can be selective when being fertilized, analogous to female choice. Mating types, which determine genetic compatibility among fungal gametes, are important for sexual selection in two respects. First, genes at the mating-type loci regulate different aspects of mating and thus can be subject to sexual selection. Second, for sexual selection, not only the two sexes (or sex roles) but also the mating types can form the classes, the members of which compete for access to members of the other class. This is significant if mating-type gene products are costly, thus signalling genetic quality according to Zahavi's handicap principle. We propose that sexual selection explains various fungal characteristics such as the observed high redundancy of pheromones at the B mating-type locus of Agaricomycotina, the occurrence of multiple types of spores in Ascomycotina or the strong pheromone signalling in yeasts. Furthermore, we argue that fungi are good model systems to experimentally study fundamental aspects of sexual selection, due to their fast generation times and high diversity of life cycles and mating systems.
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Affiliation(s)
- B P S Nieuwenhuis
- Laboratory of Genetics, Wageningen University, Wageningen, The Netherlands.
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Nygren K, Wallberg A, Samils N, Stajich JE, Townsend JP, Karlsson M, Johannesson H. Analyses of expressed sequence tags in Neurospora reveal rapid evolution of genes associated with the early stages of sexual reproduction in fungi. BMC Evol Biol 2012. [PMID: 23186325 PMCID: PMC3571971 DOI: 10.1186/1471-2148-12-229] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Background The broadly accepted pattern of rapid evolution of reproductive genes is primarily based on studies of animal systems, although several examples of rapidly evolving genes involved in reproduction are found in diverse additional taxa. In fungi, genes involved in mate recognition have been found to evolve rapidly. However, the examples are too few to draw conclusions on a genome scale. Results In this study, we performed microarray hybridizations between RNA from sexual and vegetative tissues of two strains of the heterothallic (self-sterile) filamentous ascomycete Neurospora intermedia, to identify a set of sex-associated genes in this species. We aligned Expressed Sequence Tags (ESTs) from sexual and vegetative tissue of N. intermedia to orthologs from three closely related species: N. crassa, N. discreta and N. tetrasperma. The resulting four-species alignments provided a dataset for molecular evolutionary analyses. Our results confirm a general pattern of rapid evolution of fungal sex-associated genes, compared to control genes with constitutive expression or a high relative expression during vegetative growth. Among the rapidly evolving sex-associated genes, we identified candidates that could be of importance for mating or fruiting-body development. Analyses of five of these candidate genes from additional species of heterothallic Neurospora revealed that three of them evolve under positive selection. Conclusions Taken together, our study represents a novel finding of a genome-wide pattern of rapid evolution of sex-associated genes in the fungal kingdom, and provides a list of candidate genes important for reproductive isolation in Neurospora.
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Affiliation(s)
- Kristiina Nygren
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18 D, SE-752 36, Uppsala, Sweden
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