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Wang J, Quan R, He X, Fu Q, Tian S, Zhao L, Li S, Shi L, Li R, Chen B. Hypovirus infection induces proliferation and perturbs functions of mitochondria in the chestnut blight fungus. Front Microbiol 2023; 14:1206603. [PMID: 37448575 PMCID: PMC10336323 DOI: 10.3389/fmicb.2023.1206603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 05/26/2023] [Indexed: 07/15/2023] Open
Abstract
Introduction The chestnut blight fungus, Cryphonectria parasitica, and hypovirus have been used as a model to probe the mechanism of virulence and regulation of traits important to the host fungus. Previous studies have indicated that mitochondria could be the primary target of the hypovirus. Methods In this study, we report a comprehensive and comparative study comprising mitochondrion quantification, reactive oxygen species (ROS) and respiratory efficiency, and quantitative mitochondrial proteomics of the wild-type and virus-infected strains of the chestnut blight fungus. Results and discussion Our data show that hypovirus infection increases the total number of mitochondria, lowers the general ROS level, and increases mitochondrial respiratory efficiency. Quantification of mitochondrial proteomes revealed that a set of proteins functioning in energy metabolism and mitochondrial morphogenesis, as well as virulence, were regulated by the virus. In addition, two viral proteins, p29 and p48, were found to co-fractionate with the mitochondrial membrane and matrix. These results suggest that hypovirus perturbs the host mitochondrial functions to result in hypovirulence.
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Affiliation(s)
- Jinzi Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and College of Life Science and Technology, Guangxi University, Nanning, China
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, Key Laboratory of Protection and Utilization of Marine Resources, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, China
| | - Rui Quan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and College of Life Science and Technology, Guangxi University, Nanning, China
| | - Xipu He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and College of Life Science and Technology, Guangxi University, Nanning, China
| | - Qiang Fu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and College of Life Science and Technology, Guangxi University, Nanning, China
| | - Shigen Tian
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and College of Life Science and Technology, Guangxi University, Nanning, China
| | - Lijiu Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and College of Life Science and Technology, Guangxi University, Nanning, China
| | - Shuangcai Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and College of Life Science and Technology, Guangxi University, Nanning, China
| | - Liming Shi
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and College of Life Science and Technology, Guangxi University, Nanning, China
| | - Ru Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and College of Life Science and Technology, Guangxi University, Nanning, China
| | - Baoshan Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and College of Life Science and Technology, Guangxi University, Nanning, China
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Crouch JA, Dawe A, Aerts A, Barry K, Churchill ACL, Grimwood J, Hillman BI, Milgroom MG, Pangilinan J, Smith M, Salamov A, Schmutz J, Yadav JS, Grigoriev IV, Nuss DL. Genome Sequence of the Chestnut Blight Fungus Cryphonectria parasitica EP155: A Fundamental Resource for an Archetypical Invasive Plant Pathogen. PHYTOPATHOLOGY 2020; 110:1180-1188. [PMID: 32207662 DOI: 10.1094/phyto-12-19-0478-a] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Cryphonectria parasitica is the causal agent of chestnut blight, a fungal disease that almost entirely eliminated mature American chestnut from North America over a 50-year period. Here, we formally report the genome of C. parasitica EP155 using a Sanger shotgun sequencing approach. After finishing and integration with simple-sequence repeat markers, the assembly was 43.8 Mb in 26 scaffolds (L50 = 5; N50 = 4.0Mb). Eight chromosomes are predicted: five scaffolds have two telomeres and six scaffolds have one telomere sequence. In total, 11,609 gene models were predicted, of which 85% show similarities to other proteins. This genome resource has already increased the utility of a fundamental plant pathogen experimental system through new understanding of the fungal vegetative incompatibility system, with significant implications for enhancing mycovirus-based biological control.
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Affiliation(s)
- Jo Anne Crouch
- Mycology and Nematology Genetic Diversity and Biology Laboratory, United States Department of Agriculture-Agricultural Research Service, 10300 Baltimore Avenue, Building 010A, Beltsville, MD, U.S.A
| | - Angus Dawe
- Department of Biological Sciences, Mississippi State University, 295 Lee Boulevard, Mississippi State, MS, U.S.A
| | - Andrea Aerts
- United States Department of Energy Joint Genome Institute, Walnut Creek, CA, U.S.A
| | - Kerrie Barry
- United States Department of Energy Joint Genome Institute, Walnut Creek, CA, U.S.A
| | - Alice C L Churchill
- School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, Ithaca, NY, U.S.A
| | - Jane Grimwood
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, U.S.A
| | - Bradley I Hillman
- Department of Plant Biology, Rutgers University, 59 Dudley Road, New Brunswick, NJ, U.S.A
| | - Michael G Milgroom
- School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, Ithaca, NY, U.S.A
| | - Jasmyn Pangilinan
- United States Department of Energy Joint Genome Institute, Walnut Creek, CA, U.S.A
| | - Myron Smith
- Department of Biology, Carleton University, 1125 Colonel by Drive, Ottawa, ON, Canada
| | - Asaf Salamov
- United States Department of Energy Joint Genome Institute, Walnut Creek, CA, U.S.A
| | - Jeremy Schmutz
- United States Department of Energy Joint Genome Institute, Walnut Creek, CA, U.S.A
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, U.S.A
| | - Jagjit S Yadav
- Environmental Genetics and Molecular Toxicology Division, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, U.S.A
| | - Igor V Grigoriev
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, U.S.A
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, U.S.A
| | - Donald L Nuss
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, U.S.A
- Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV, U.S.A
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3
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Nerva L, Chitarra W, Siciliano I, Gaiotti F, Ciuffo M, Forgia M, Varese GC, Turina M. Mycoviruses mediate mycotoxin regulation in Aspergillus ochraceus. Environ Microbiol 2018; 21:1957-1968. [PMID: 30289193 DOI: 10.1111/1462-2920.14436] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 09/24/2018] [Accepted: 09/27/2018] [Indexed: 12/30/2022]
Abstract
To date, no demonstration of a direct correlation between the presence of mycoviruses and the quantitative or qualitative modulation of mycotoxins has been shown. In our study, we transfected a virus-free ochratoxin A (OTA)-producing isolate of Aspergillus ochraceus with purified mycoviruses from a different A. ochraceus isolate and from Penicillium aurantiogriseum. Among the mycoviruses tested, only Aspergillus ochraceus virus (AoV), a partitivirus widespread in A. ochraceus, caused a specific interaction that led to an overproduction of OTA, which is regulated by the European Commission and is the second most important contaminant of food and feed commodities. Gene expression analysis failed to reveal a specific viral upregulation of the mRNA of genes considered to play a role in the OTA biosynthetic pathway. Furthermore, AoOTApks1, a polyketide synthase gene considered essential for OTA production, is surprisingly absent in the genome of our OTA-producing isolate. The possible biological and evolutionary implications of the mycoviral regulation of mycotoxin production are discussed.
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Affiliation(s)
- L Nerva
- Council for Agricultural Research and Economics - Research Centre for Viticulture and Enology CREA-VE, Via XXVIII Aprile 26, 31015, Conegliano (TV), Italy.,Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135, Torino, Italy
| | - W Chitarra
- Council for Agricultural Research and Economics - Research Centre for Viticulture and Enology CREA-VE, Via XXVIII Aprile 26, 31015, Conegliano (TV), Italy.,Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135, Torino, Italy
| | - I Siciliano
- Council for Agricultural Research and Economics - Research Centre for Viticulture and Enology CREA-VE, Via XXVIII Aprile 26, 31015, Conegliano (TV), Italy
| | - F Gaiotti
- Council for Agricultural Research and Economics - Research Centre for Viticulture and Enology CREA-VE, Via XXVIII Aprile 26, 31015, Conegliano (TV), Italy
| | - M Ciuffo
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135, Torino, Italy
| | - M Forgia
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135, Torino, Italy.,Mycotheca Universitatis Taurinensis (MUT), Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125, Torino, Italy
| | - G C Varese
- Mycotheca Universitatis Taurinensis (MUT), Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125, Torino, Italy
| | - M Turina
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135, Torino, Italy
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4
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Δ(1)-pyrroline-5-carboxylate/glutamate biogenesis is required for fungal virulence and sporulation. PLoS One 2013; 8:e73483. [PMID: 24039956 PMCID: PMC3767830 DOI: 10.1371/journal.pone.0073483] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 07/22/2013] [Indexed: 11/19/2022] Open
Abstract
Proline dehydrogenase (Prodh) and Δ1-pyrroline-5-carboxylate dehydrogenase (P5Cdh) are two key enzymes in the cellular biogenesis of glutamate. Recombinant Prodh and P5Cdh proteins of the chestnut blight fungus Cryphonectria parasitica were investigated and showed activity in in vitro assays. Additionally, the C. parasitica Prodh and P5Cdh genes were able to complement the Saccharomyces cerevisiae put1 and put2 null mutants, respectively, to allow these proline auxotrophic yeast mutants to grow on media with proline as the sole source of nitrogen. Deletion of the Prodh gene in C. parasitica resulted in hypovirulence and a lower level of sporulation, whereas deletion of P5Cdh resulted in hypovirulence though no effect on sporulation; both Δprodh and Δp5cdh mutants were unable to grow on minimal medium with proline as the sole nitrogen source. In a wild-type strain, the intracellular level of proline and the activity of Prodh and P5Cdh increased after supplementation of exogenous proline, though the intracellular Δ1-pyrroline-5-carboxylate (P5C) content remained unchanged. Prodh and P5Cdh were both transcriptionally down-regulated in cells infected with hypovirus. The disruption of other genes with products involved in the conversion of arginine to ornithine, ornithine and glutamate to P5C, and P5C to proline in the cytosol did not appear to affect virulence; however, asexual sporulation was reduced in the Δpro1 and Δpro2 mutants. Taken together, our results showed that Prodh, P5Cdh and related mitochondrial functions are essential for virulence and that proline/glutamate pathway components may represent down-stream targets of hypovirus regulation in C. parasitica.
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5
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Dawe AL, Nuss DL. Hypovirus molecular biology: from Koch's postulates to host self-recognition genes that restrict virus transmission. Adv Virus Res 2013; 86:109-47. [PMID: 23498905 DOI: 10.1016/b978-0-12-394315-6.00005-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The idea that viruses can be used to control fungal diseases has been a driving force in mycovirus research since the earliest days. Viruses in the family Hypoviridae associated with reduced virulence (hypovirulence) of the chestnut blight fungus, Cryphonectria parasitica, have held a prominent place in this research. This has been due in part to the severity of the chestnut blight epidemics in North America and Europe and early reports of hypovirulence-mediated mitigation of disease in European forests and successful application for control of chestnut blight in chestnut orchards. A more recent contributing factor has been the development of a hypovirus/C. parasitica experimental system that has overcome many of the challenges associated with mycovirus research, stemming primarily from the exclusive intracellular lifestyle shared by all mycoviruses. This chapter will focus on hypovirus molecular biology with an emphasis on the development of the hypovirus/C. parasitica experimental system and its contributions to fundamental and practical advances in mycovirology and the broader understanding of virus-host interactions and fungal pathogenesis.
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Affiliation(s)
- Angus L Dawe
- Department of Biology, New Mexico State University, Las Cruces, NM, USA
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6
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Abstract
All life must survive their corresponding viruses. Thus antiviral systems are essential in all living organisms. Remnants of virus derived information are also found in all life forms but have historically been considered mostly as junk DNA. However, such virus derived information can strongly affect host susceptibility to viruses. In this review, I evaluate the role viruses have had in the origin and evolution of host antiviral systems. From Archaea through bacteria and from simple to complex eukaryotes I trace the viral components that became essential elements of antiviral immunity. I conclude with a reexamination of the 'Big Bang' theory for the emergence of the adaptive immune system in vertebrates by horizontal transfer and note how viruses could have and did provide crucial and coordinated features.
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7
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Villarreal LP. Viral ancestors of antiviral systems. Viruses 2011; 3:1933-58. [PMID: 22069523 PMCID: PMC3205389 DOI: 10.3390/v3101933] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 10/01/2011] [Accepted: 10/10/2011] [Indexed: 02/06/2023] Open
Abstract
All life must survive their corresponding viruses. Thus antiviral systems are essential in all living organisms. Remnants of virus derived information are also found in all life forms but have historically been considered mostly as junk DNA. However, such virus derived information can strongly affect host susceptibility to viruses. In this review, I evaluate the role viruses have had in the origin and evolution of host antiviral systems. From Archaea through bacteria and from simple to complex eukaryotes I trace the viral components that became essential elements of antiviral immunity. I conclude with a reexamination of the 'Big Bang' theory for the emergence of the adaptive immune system in vertebrates by horizontal transfer and note how viruses could have and did provide crucial and coordinated features.
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Affiliation(s)
- Luis P Villarreal
- Center for Virus Research, University of California, Irvine, CA 92697, USA.
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8
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Baidyaroy D, Hausner G, Hafez M, Michel F, Fulbright DW, Bertrand H. A 971-bp insertion in the rns gene is associated with mitochondrial hypovirulence in a strain of Cryphonectria parasitica isolated from nature. Fungal Genet Biol 2011; 48:775-83. [DOI: 10.1016/j.fgb.2011.05.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 03/18/2011] [Accepted: 05/08/2011] [Indexed: 01/16/2023]
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9
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Baidyaroy D, Hausner G, Fulbright DW, Bertrand H. Mitochondrial plasmid-like elements in some hypovirulent strains of Cryphonectria parasitica. Fungal Genet Biol 2011; 48:764-74. [DOI: 10.1016/j.fgb.2011.05.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 03/17/2011] [Accepted: 05/08/2011] [Indexed: 10/18/2022]
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10
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Monteiro-Vitorello CB, Hausner G, Searles DB, Gibb EA, Fulbright DW, Bertrand H. The Cryphonectria parasitica mitochondrial rns gene: plasmid-like elements, introns and homing endonucleases. Fungal Genet Biol 2009; 46:837-48. [PMID: 19607930 DOI: 10.1016/j.fgb.2009.07.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2009] [Revised: 06/24/2009] [Accepted: 07/08/2009] [Indexed: 10/20/2022]
Abstract
The mt-rns gene of Cryphonectria parasitica is 9872bp long and includes two group I and two group II introns. An analysis of intronic protein-encoding sequences revealed that LAGLIDADG ORFs, which usually are associated with group I introns, were transferred at least twice into group II introns. A plasmid-like mitochondrial element (plME) that appears in high amounts in previously mutagen-induced mit1 and mit2 hypovirulent mutants of the Ep155 standard virulent strain of C. parasitica was found to be derived from a short region of the mt-rns gene, including the exon 1 and most of the first intron. The plME is a 4.2-kb circular, multimeric DNA and an autonomously-replicating mtDNA fragment. Although sexual transmission experiments indicate that the plME does not directly cause hypovirulence, its emergence is one manifestation of the many complex molecular and genetic events that appear to underlie this phenotype.
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11
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Dawe AL, Van Voorhies WA, Lau TA, Ulanov AV, Li Z. Major impacts on the primary metabolism of the plant pathogen Cryphonectria parasitica by the virulence-attenuating virus CHV1-EP713. MICROBIOLOGY-SGM 2009; 155:3913-3921. [PMID: 19589830 DOI: 10.1099/mic.0.029033-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cryphonectria parasitica, the chestnut blight fungus, can be infected by virulence-attenuating mycoviruses of the family Hypoviridae. Previous studies have led to the hypothesis that the hypovirus-infected phenotype is partly due to metabolic changes induced by the viral infection. To investigate this, we measured the metabolic rate and respiration of C. parasitica colonies grown on solid medium. These experiments supported historical observations of other fungal species done in liquid cultures that the metabolic rate steadily declines with age and differentiation of the mycelium. Hypovirus infection increased metabolic rate in the youngest mycelium, but a subsequent decline was also observed as the mycelium aged. By measuring both CO(2) production and O(2) consumption, we also observed that changes occur in carbohydrate metabolism as a result of ageing in both infected and uninfected mycelium. Mycelium on the periphery of the colony exploited fermentation pathways extensively, before transitioning to aerobic carbohydrate metabolism and finally lipid metabolism in the interior regions, despite abundant remaining glucose. However, the hypovirus affected the extent of these changes, with infected mycelium apparently unable to utilize lipid-related metabolic pathways, leading to an increased depletion of glucose. Finally, we used metabolic profi fi ling to determine the changes in accumulation of primary metabolites in wild-type and hypovirus-infected mycelium and found that approximately one-third of the 164 detected metabolites were affected. These results are consistent with those expected from the physiological measurements, with significant alterations noted for compounds related to lipid and carbohydrate metabolism. Additionally, we observed an increase in the accumulation of the polyamine spermidine in the presence of hypovirus. Polyamines have been implicated in antiviral responses of mammalian systems; therefore this may suggest a novel antiviral response mechanism in fungi.
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Affiliation(s)
- Angus L Dawe
- Molecular Biology Program, New Mexico State University, Las Cruces, NM 88003, USA.,Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
| | - Wayne A Van Voorhies
- Molecular Biology Program, New Mexico State University, Las Cruces, NM 88003, USA
| | - Tannia A Lau
- Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
| | - Alexander V Ulanov
- Roy J. Carver Biotechnology Center, University of Illinois, Urbana, IL 61801, USA
| | - Zhong Li
- Roy J. Carver Biotechnology Center, University of Illinois, Urbana, IL 61801, USA
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12
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Kim JS, Sagaram US, Burns JK, Li JL, Wang N. Response of sweet orange (Citrus sinensis) to 'Candidatus Liberibacter asiaticus' infection: microscopy and microarray analyses. PHYTOPATHOLOGY 2009; 99:50-7. [PMID: 19055434 DOI: 10.1094/phyto-99-1-0050] [Citation(s) in RCA: 167] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Citrus greening or huanglongbing (HLB) is a devastating disease of citrus. HLB is associated with the phloem-limited fastidious prokaryotic alpha-proteobacterium 'Candidatus Liberibacter spp.' In this report, we used sweet orange (Citrus sinensis) leaf tissue infected with 'Ca. Liberibacter asiaticus' and compared this with healthy controls. Investigation of the host response was examined with citrus microarray hybridization based on 33,879 expressed sequence tag sequences from several citrus species and hybrids. The microarray analysis indicated that HLB infection significantly affected expression of 624 genes whose encoded proteins were categorized according to function. The categories included genes associated with sugar metabolism, plant defense, phytohormone, and cell wall metabolism, as well as 14 other gene categories. The anatomical analyses indicated that HLB bacterium infection caused phloem disruption, sucrose accumulation, and plugged sieve pores. The up-regulation of three key starch biosynthetic genes including ADP-glucose pyrophosphorylase, starch synthase, granule-bound starch synthase and starch debranching enzyme likely contributed to accumulation of starch in HLB-affected leaves. The HLB-associated phloem blockage resulted from the plugged sieve pores rather than the HLB bacterial aggregates since 'Ca. Liberibacter asiaticus' does not form aggregate in citrus. The up-regulation of pp2 gene is related to callose deposition to plug the sieve pores in HLB-affected plants.
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Affiliation(s)
- Jeong-Soon Kim
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850, USA
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13
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Deletion of the cpku80 gene in the chestnut blight fungus, Cryphonectria parasitica, enhances gene disruption efficiency. Curr Genet 2007; 53:59-66. [PMID: 17972079 DOI: 10.1007/s00294-007-0162-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2007] [Revised: 10/10/2007] [Accepted: 10/11/2007] [Indexed: 10/22/2022]
Abstract
The chestnut blight fungus, Cryphonectria parasitica, and associated virulence-attenuating hypoviruses have emerged as an important model system for studying molecular mechanisms underlying fungal-plant pathogenic interactions. As more gene sequence information becomes available as a result of C. parasitica express sequence tags (ESTs) and ongoing whole genome sequencing projects, the development of an efficient gene disruption system has become an urgent need for functional genomics studies of this important forestry pathogen. Here, we report the cloning of the C. parasitica gene cpku80 that encodes a key component of the nonhomologous end joining DNA repair pathway and the construction of a corresponding deletion mutant strain. The cpku80 mutant was indistinguishable from the parental wild-type strain EP155 in colony morphology, ability to support hypovirus replication, conidiation and virulence. As predicted, the Deltacpku80 strain did exhibit an increased sensitivity to the mutagen methyl methanesulfonate. A test with three selected genes resulted in a gene disruption efficiency of about 80% for the Deltacpku80 strain, a significant increase over the 2-5% levels of homologous recombination generally observed for the wild-type strain EP155. This efficient homologous recombination system provides a powerful tool for large-scale analysis of gene functions in C. parasitica.
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Abstract
Microarray studies have examined global gene expression in over 20 species of filamentous fungi encompassing a wide variety of research areas. The majority have addressed aspects of metabolism or pathogenicity. Metabolic studies have revealed important differences in the transcriptional regulation of genes for primary metabolic pathways between filamentous fungi and yeast. Transcriptional profiles for genes involved in secondary metabolism have also been established. Genes required for the biosynthesis of both useful and detrimental secondary metabolites have been identified. Due to the economic, ecological and medical implications, it is not surprising that many studies have used microarray analysis to examine gene expression in pathogenic filamentous fungi. Genes involved in various stages of pathogenicity have been identified, including those thought to be important for adaptation to the host environment. While most of the studies have simulated pathogenic conditions in vitro, a small number have also reported fungal gene expression within their plant hosts. This review summarizes the first 50 microarray studies in filamentous fungi and highlights areas for future investigation.
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Affiliation(s)
- Andrew Breakspear
- Department of Plant Biology, The University of Georgia, 1505 Miller Plant Sciences, Athens, GA 30602, USA
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15
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Abstract
Whereas most mycoviruses lead 'secret lives', some reduce the ability of their fungal hosts to cause disease in plants. This property, known as hypovirulence, has attracted attention owing to the importance of fungal diseases in agriculture and the limited strategies that are available for the control of these diseases. Using one pathogen to control another is appealing, both intellectually and ecologically. The recent development of an infectious cDNA-based reverse genetics system for members of the Hypoviridae mycovirus family has enabled the analysis of basic aspects of this fascinating virus-fungus-plant interaction, including virus-host interactions, the mechanisms underlying fungal pathogenesis, fungal signalling pathways and the evolution of RNA silencing. Such systems also provide a means for engineering mycoviruses for enhanced biocontrol potential.
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Affiliation(s)
- Donald L Nuss
- Center for Biosystems Research, 5115 Plant Sciences Building, University of Maryland Biotechnology Institute, College Park, Maryland 20742, USA.
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Nowrousian M, Ringelberg C, Dunlap JC, Loros JJ, Kück U. Cross-species microarray hybridization to identify developmentally regulated genes in the filamentous fungus Sordaria macrospora. Mol Genet Genomics 2005; 273:137-49. [PMID: 15778868 DOI: 10.1007/s00438-005-1118-9] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2004] [Accepted: 01/10/2005] [Indexed: 11/28/2022]
Abstract
The filamentous fungus Sordaria macrospora forms complex three-dimensional fruiting bodies that protect the developing ascospores and ensure their proper discharge. Several regulatory genes essential for fruiting body development were previously isolated by complementation of the sterile mutants pro1, pro11 and pro22. To establish the genetic relationships between these genes and to identify downstream targets, we have conducted cross-species microarray hybridizations using cDNA arrays derived from the closely related fungus Neurospora crassa and RNA probes prepared from wild-type S. macrospora and the three developmental mutants. Of the 1,420 genes which gave a signal with the probes from all the strains used, 172 (12%) were regulated differently in at least one of the three mutants compared to the wild type, and 17 (1.2%) were regulated differently in all three mutant strains. Microarray data were verified by Northern analysis or quantitative real time PCR. Among the genes that are up- or down-regulated in the mutant strains are genes encoding the pheromone precursors, enzymes involved in melanin biosynthesis and a lectin-like protein. Analysis of gene expression in double mutants revealed a complex network of interaction between the pro gene products.
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Affiliation(s)
- Minou Nowrousian
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum ND 7/131, Universitätsstr. 150, 44801, Bochum, Germany
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17
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Current Awareness on Comparative and Functional Genomics. Comp Funct Genomics 2005. [PMCID: PMC2447519 DOI: 10.1002/cfg.420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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