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Erlendson AA, Friedman S, Freitag M. A Matter of Scale and Dimensions: Chromatin of Chromosome Landmarks in the Fungi. Microbiol Spectr 2017; 5:10.1128/microbiolspec.FUNK-0054-2017. [PMID: 28752814 PMCID: PMC5536859 DOI: 10.1128/microbiolspec.funk-0054-2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Indexed: 02/06/2023] Open
Abstract
Chromatin and chromosomes of fungi are highly diverse and dynamic, even within species. Much of what we know about histone modification enzymes, RNA interference, DNA methylation, and cell cycle control was first addressed in Saccharomyces cerevisiae, Schizosaccharomyces pombe, Aspergillus nidulans, and Neurospora crassa. Here, we examine the three landmark regions that are required for maintenance of stable chromosomes and their faithful inheritance, namely, origins of DNA replication, telomeres and centromeres. We summarize the state of recent chromatin research that explains what is required for normal function of these specialized chromosomal regions in different fungi, with an emphasis on the silencing mechanism associated with subtelomeric regions, initiated by sirtuin histone deacetylases and histone H3 lysine 27 (H3K27) methyltransferases. We explore mechanisms for the appearance of "accessory" or "conditionally dispensable" chromosomes and contrast what has been learned from studies on genome-wide chromosome conformation capture in S. cerevisiae, S. pombe, N. crassa, and Trichoderma reesei. While most of the current knowledge is based on work in a handful of genetically and biochemically tractable model organisms, we suggest where major knowledge gaps remain to be closed. Fungi will continue to serve as facile organisms to uncover the basic processes of life because they make excellent model organisms for genetics, biochemistry, cell biology, and evolutionary biology.
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Affiliation(s)
- Allyson A. Erlendson
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331
| | - Steven Friedman
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331
| | - Michael Freitag
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331
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Sbaraini N, Andreis FC, Thompson CE, Guedes RLM, Junges Â, Campos T, Staats CC, Vainstein MH, Ribeiro de Vasconcelos AT, Schrank A. Genome-Wide Analysis of Secondary Metabolite Gene Clusters in O phiostoma ulmi and Ophiostoma novo-ulmi Reveals a Fujikurin-Like Gene Cluster with a Putative Role in Infection. Front Microbiol 2017; 8:1063. [PMID: 28659888 PMCID: PMC5468452 DOI: 10.3389/fmicb.2017.01063] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 05/29/2017] [Indexed: 01/08/2023] Open
Abstract
The emergence of new microbial pathogens can result in destructive outbreaks, since their hosts have limited resistance and pathogens may be excessively aggressive. Described as the major ecological incident of the twentieth century, Dutch elm disease, caused by ascomycete fungi from the Ophiostoma genus, has caused a significant decline in elm tree populations (Ulmus sp.) in North America and Europe. Genome sequencing of the two main causative agents of Dutch elm disease (Ophiostoma ulmi and Ophiostoma novo-ulmi), along with closely related species with different lifestyles, allows for unique comparisons to be made to identify how pathogens and virulence determinants have emerged. Among several established virulence determinants, secondary metabolites (SMs) have been suggested to play significant roles during phytopathogen infection. Interestingly, the secondary metabolism of Dutch elm pathogens remains almost unexplored, and little is known about how SM biosynthetic genes are organized in these species. To better understand the metabolic potential of O. ulmi and O. novo-ulmi, we performed a deep survey and description of SM biosynthetic gene clusters (BGCs) in these species and assessed their conservation among eight species from the Ophiostomataceae family. Among 19 identified BGCs, a fujikurin-like gene cluster (OpPKS8) was unique to Dutch elm pathogens. Phylogenetic analysis revealed that orthologs for this gene cluster are widespread among phytopathogens and plant-associated fungi, suggesting that OpPKS8 may have been horizontally acquired by the Ophiostoma genus. Moreover, the detailed identification of several BGCs paves the way for future in-depth research and supports the potential impact of secondary metabolism on Ophiostoma genus’ lifestyle.
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Affiliation(s)
- Nicolau Sbaraini
- Rede Avançada em Biologia ComputacionalPetrópolis, Brazil.,Centro de Biotecnologia, Programa de Pós-Graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil
| | - Fábio C Andreis
- Rede Avançada em Biologia ComputacionalPetrópolis, Brazil.,Centro de Biotecnologia, Programa de Pós-Graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil
| | - Claudia E Thompson
- Rede Avançada em Biologia ComputacionalPetrópolis, Brazil.,Centro de Biotecnologia, Programa de Pós-Graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil.,Laboratório Nacional de Computação CientíficaPetrópolis, Brazil
| | - Rafael L M Guedes
- Rede Avançada em Biologia ComputacionalPetrópolis, Brazil.,Laboratório Nacional de Computação CientíficaPetrópolis, Brazil
| | - Ângela Junges
- Centro de Biotecnologia, Programa de Pós-Graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil
| | - Thais Campos
- Centro de Biotecnologia, Programa de Pós-Graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil
| | - Charley C Staats
- Rede Avançada em Biologia ComputacionalPetrópolis, Brazil.,Centro de Biotecnologia, Programa de Pós-Graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil
| | - Marilene H Vainstein
- Rede Avançada em Biologia ComputacionalPetrópolis, Brazil.,Centro de Biotecnologia, Programa de Pós-Graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil
| | - Ana T Ribeiro de Vasconcelos
- Rede Avançada em Biologia ComputacionalPetrópolis, Brazil.,Laboratório Nacional de Computação CientíficaPetrópolis, Brazil
| | - Augusto Schrank
- Rede Avançada em Biologia ComputacionalPetrópolis, Brazil.,Centro de Biotecnologia, Programa de Pós-Graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil
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Rybak K, See PT, Phan HTT, Syme RA, Moffat CS, Oliver RP, Tan K. A functionally conserved Zn 2 Cys 6 binuclear cluster transcription factor class regulates necrotrophic effector gene expression and host-specific virulence of two major Pleosporales fungal pathogens of wheat. MOLECULAR PLANT PATHOLOGY 2017; 18:420-434. [PMID: 27860150 PMCID: PMC6638278 DOI: 10.1111/mpp.12511] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The fungus Parastagonospora nodorum is the causal agent of Septoria nodorum blotch of wheat (Triticum aestivum). The interaction is mediated by multiple fungal necrotrophic effector-dominant host sensitivity gene interactions. The three best-characterized effector-sensitivity gene systems are SnToxA-Tsn1, SnTox1-Snn1 and SnTox3-Snn3. These effector genes are highly expressed during early infection, but expression decreases as the infection progresses to tissue necrosis and sporulation. However, the mechanism of regulation is unknown. We have identified and functionally characterized a gene, referred to as PnPf2, which encodes a putative zinc finger transcription factor. PnPf2 deletion resulted in the down-regulation of SnToxA and SnTox3 expression. Virulence on Tsn1 and Snn3 wheat cultivars was strongly reduced. The SnTox1-Snn1 interaction remained unaffected. Furthermore, we have also identified and deleted an orthologous PtrPf2 from the tan spot fungus Pyrenophora tritici-repentis which possesses a near-identical ToxA that was acquired from P. nodorum via horizontal gene transfer. PtrPf2 deletion also resulted in the down-regulation of PtrToxA expression and a near-complete loss of virulence on Tsn1 wheat. We have demonstrated, for the first time, evidence for a functionally conserved signalling component that plays a role in the regulation of a common/horizontally transferred effector found in two major fungal pathogens of wheat.
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Affiliation(s)
- Kasia Rybak
- Department of Environment & Agriculture, Centre for Crop and Disease ManagementCurtin University, Bentley, 6102PerthAustralia
| | - Pao Theen See
- Department of Environment & Agriculture, Centre for Crop and Disease ManagementCurtin University, Bentley, 6102PerthAustralia
| | - Huyen T. T. Phan
- Department of Environment & Agriculture, Centre for Crop and Disease ManagementCurtin University, Bentley, 6102PerthAustralia
| | - Robert A. Syme
- Department of Environment & Agriculture, Centre for Crop and Disease ManagementCurtin University, Bentley, 6102PerthAustralia
| | - Caroline S. Moffat
- Department of Environment & Agriculture, Centre for Crop and Disease ManagementCurtin University, Bentley, 6102PerthAustralia
| | - Richard P. Oliver
- Department of Environment & Agriculture, Centre for Crop and Disease ManagementCurtin University, Bentley, 6102PerthAustralia
| | - Kar‐Chun Tan
- Department of Environment & Agriculture, Centre for Crop and Disease ManagementCurtin University, Bentley, 6102PerthAustralia
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Pan L, Li X, Jin H, Yang X, Qin B. Antifungal activity of umbelliferone derivatives: Synthesis and structure-activity relationships. Microb Pathog 2017; 104:110-115. [PMID: 28089948 DOI: 10.1016/j.micpath.2017.01.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 01/04/2017] [Accepted: 01/11/2017] [Indexed: 11/15/2022]
Abstract
Umbelliferone was an important allelochemical with a wide spectrum bioactivity. In our previous study, C7 hydroxy in the backbone of umbelliferone was identified to be responsible for its phytotoxicity and the targeted modification of the above site could lead to the phytotoxicity loss. In view of this, a series of hydroxycoumarins and C7 O-substituted umbelliferone derivatives were efficiently synthesized to evaluate their antifungal activity against four phytopathogenic fungi. Most of them, as we predicted, exhibited improved fungicidal activity. The phytotoxicity of effective compounds was also assayed by Lactuca sativa to investigate their side effects on plant growth. Compounds 9 and 17 were identified to show strong antifungal activity with low phytotoxicity. A brief investigation on structure-activity relationships revealed that the modification at the C7 hydroxy of umbelliferone could be a promising way to enhance the antifungal activity with decreasing the phytotoxicity.
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Affiliation(s)
- Le Pan
- Key Laboratory of Chemistry of Northwestern Plant Resources of CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China; Chemical Engineering College, Xinjiang Agricultural University, Urumqi 830052, People's Republic of China
| | - Xiuzhuang Li
- Key Laboratory of Chemistry of Northwestern Plant Resources of CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China.
| | - Hui Jin
- Key Laboratory of Chemistry of Northwestern Plant Resources of CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
| | - Xiaoyan Yang
- Key Laboratory of Chemistry of Northwestern Plant Resources of CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
| | - Bo Qin
- Key Laboratory of Chemistry of Northwestern Plant Resources of CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China.
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Crous PW, Groenewald JZ, Slippers B, Wingfield MJ. Global food and fibre security threatened by current inefficiencies in fungal identification. Philos Trans R Soc Lond B Biol Sci 2016; 371:20160024. [PMID: 28080994 PMCID: PMC5095547 DOI: 10.1098/rstb.2016.0024] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2016] [Indexed: 01/02/2023] Open
Abstract
Fungal pathogens severely impact global food and fibre crop security. Fungal species that cause plant diseases have mostly been recognized based on their morphology. In general, morphological descriptions remain disconnected from crucially important knowledge such as mating types, host specificity, life cycle stages and population structures. The majority of current fungal species descriptions lack even the most basic genetic data that could address at least some of these issues. Such information is essential for accurate fungal identifications, to link critical metadata and to understand the real and potential impact of fungal pathogens on production and natural ecosystems. Because international trade in plant products and introduction of pathogens to new areas is likely to continue, the manner in which fungal pathogens are identified should urgently be reconsidered. The technologies that would provide appropriate information for biosecurity and quarantine already exist, yet the scientific community and the regulatory authorities are slow to embrace them. International agreements are urgently needed to enforce new guidelines for describing plant pathogenic fungi (including key DNA information), to ensure availability of relevant data and to modernize the phytosanitary systems that must deal with the risks relating to trade-associated plant pathogens.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'.
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Affiliation(s)
- Pedro W Crous
- CBS-KNAW Fungal Biodiversity Centre, PO Box 85167, 3508 AD Utrecht, The Netherlands
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P. Bag X20, Pretoria 0028, South Africa
- Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | | | - Bernard Slippers
- Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P. Bag X20, Pretoria 0028, South Africa
| | - Michael J Wingfield
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P. Bag X20, Pretoria 0028, South Africa
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56
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De Wit PJGM. Apoplastic fungal effectors in historic perspective; a personal view. THE NEW PHYTOLOGIST 2016; 212:805-813. [PMID: 27523582 DOI: 10.1111/nph.14144] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Affiliation(s)
- Pierre J G M De Wit
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
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57
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Abstract
Lateral gene transfer (LGT) is the transmission of genes, sometimes across species barriers, outwith the classic vertical inheritance from parent to offspring. LGT is recognized as an important phenomenon that has shaped the genomes and biology of prokaryotes. Whether LGT in eukaryotes is important and widespread remains controversial. A study in BMC Biology concludes that LGT in eukaryotes is neither continuous nor prevalent and suggests a rule of thumb for judging when apparent LGT may reflect contamination.See research article: http://bmcbiol.biomedcentral.com/articles/10.1186/s12915-016-0315-9 .
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Affiliation(s)
- Etienne G J Danchin
- Institut Sophia Agrobiotech, INRA, University of Nice Sophia Antipolis, CNRS, 06903, Sophia Antipolis, France.
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58
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Vanheule A, Audenaert K, Warris S, van de Geest H, Schijlen E, Höfte M, De Saeger S, Haesaert G, Waalwijk C, van der Lee T. Living apart together: crosstalk between the core and supernumerary genomes in a fungal plant pathogen. BMC Genomics 2016; 17:670. [PMID: 27552804 PMCID: PMC4994206 DOI: 10.1186/s12864-016-2941-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 07/14/2016] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Eukaryotes display remarkable genome plasticity, which can include supernumerary chromosomes that differ markedly from the core chromosomes. Despite the widespread occurrence of supernumerary chromosomes in fungi, their origin, relation to the core genome and the reason for their divergent characteristics are still largely unknown. The complexity of genome assembly due to the presence of repetitive DNA partially accounts for this. RESULTS Here we use single-molecule real-time (SMRT) sequencing to assemble the genome of a prominent fungal wheat pathogen, Fusarium poae, including at least one supernumerary chromosome. The core genome contains limited transposable elements (TEs) and no gene duplications, while the supernumerary genome holds up to 25 % TEs and multiple gene duplications. The core genome shows all hallmarks of repeat-induced point mutation (RIP), a defense mechanism against TEs, specific for fungi. The absence of RIP on the supernumerary genome accounts for the differences between the two (sub)genomes, and results in a functional crosstalk between them. The supernumerary genome is a reservoir for TEs that migrate to the core genome, and even large blocks of supernumerary sequence (>200 kb) have recently translocated to the core. Vice versa, the supernumerary genome acts as a refuge for genes that are duplicated from the core genome. CONCLUSIONS For the first time, a mechanism was determined that explains the differences that exist between the core and supernumerary genome in fungi. Different biology rather than origin was shown to be responsible. A "living apart together" crosstalk exists between the core and supernumerary genome, accelerating chromosomal and organismal evolution.
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Affiliation(s)
- Adriaan Vanheule
- Department of Applied Biosciences, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- Wageningen UR, Wageningen, The Netherlands
| | - Kris Audenaert
- Department of Applied Biosciences, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | | | | | | | - Monica Höfte
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Sarah De Saeger
- Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Geert Haesaert
- Department of Applied Biosciences, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Vlaardingerbroek I, Beerens B, Rose L, Fokkens L, Cornelissen BJC, Rep M. Exchange of core chromosomes and horizontal transfer of lineage-specific chromosomes in Fusarium oxysporum. Environ Microbiol 2016; 18:3702-3713. [PMID: 26941045 DOI: 10.1111/1462-2920.13281] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 02/22/2016] [Indexed: 01/09/2023]
Abstract
Horizontal transfer of supernumerary or lineage-specific (LS) chromosomes has been described in a number of plant pathogenic filamentous fungi. So far it was not known whether transfer is restricted to chromosomes of certain size or properties, or whether 'core' chromosomes can also undergo horizontal transfer. We combined a directed and a non-biased approach to determine whether such restrictions exist. Selection genes were integrated into the genome of a strain of Fusarium oxysporum pathogenic on tomato, either targeted to specific chromosomes by homologous recombination or integrated randomly into the genome. By testing these strains for transfer of the marker to another strain we could confirm transfer of a previously described mobile pathogenicity chromosome. Surprisingly, we also identified strains in which (parts of) core chromosomes were transferred. Whole genome sequencing revealed that this was accompanied by the loss of the homologous region from the recipient strain. Remarkably, transfer of the mobile pathogenicity chromosome always accompanied this exchange of core chromosomes.
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Affiliation(s)
| | - Bas Beerens
- Molecular Plant Pathology, University of Amsterdam, Amsterdam, The Netherlands
| | - Laura Rose
- Molecular Plant Pathology, University of Amsterdam, Amsterdam, The Netherlands
| | - Like Fokkens
- Molecular Plant Pathology, University of Amsterdam, Amsterdam, The Netherlands
| | - Ben J C Cornelissen
- Molecular Plant Pathology, University of Amsterdam, Amsterdam, The Netherlands
| | - Martijn Rep
- Molecular Plant Pathology, University of Amsterdam, Amsterdam, The Netherlands
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Nuclear dynamics and genetic rearrangement in heterokaryotic colonies of Fusarium oxysporum. Fungal Genet Biol 2016; 91:20-31. [PMID: 27013267 DOI: 10.1016/j.fgb.2016.03.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 01/31/2016] [Accepted: 03/15/2016] [Indexed: 10/22/2022]
Abstract
Recent studies have shown horizontal transfer of chromosomes to be a potential key contributor to genome plasticity in asexual fungal pathogens. However, the mechanisms behind horizontal chromosome transfer in eukaryotes are not well understood. Here we investigated the role of conidial anastomosis in heterokaryon formation between incompatible strains of Fusarium oxysporum and determined the importance of heterokaryons for horizontal chromosome transfer. Using live-cell imaging we demonstrate that conidial pairing of incompatible strains under carbon starvation can result in the formation of viable heterokaryotic hyphae in F. oxysporum. Nuclei of the parental lines presumably fuse at some stage as conidia with a single nucleus harboring both marker histones (GFP- and RFP-tagged) are produced. Upon colony formation, this hybrid offspring is subject to progressive and gradual genome rearrangement. The parental genomes appear to become spatially separated and RFP-tagged histones, deriving from one of the strains, Fol4287, are eventually lost. With a PCR-based method we showed that markers for most of the chromosomes of this strain are lost, indicating a lack of Fol4287 chromosomes. This leaves offspring with the genomic background of the other strain (Fo47), but in some cases together with one or two chromosomes from Fol4287, including the chromosome that confers pathogenicity towards tomato.
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Williams AH, Sharma M, Thatcher LF, Azam S, Hane JK, Sperschneider J, Kidd BN, Anderson JP, Ghosh R, Garg G, Lichtenzveig J, Kistler HC, Shea T, Young S, Buck SAG, Kamphuis LG, Saxena R, Pande S, Ma LJ, Varshney RK, Singh KB. Comparative genomics and prediction of conditionally dispensable sequences in legume-infecting Fusarium oxysporum formae speciales facilitates identification of candidate effectors. BMC Genomics 2016; 17:191. [PMID: 26945779 PMCID: PMC4779268 DOI: 10.1186/s12864-016-2486-8] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 02/17/2016] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Soil-borne fungi of the Fusarium oxysporum species complex cause devastating wilt disease on many crops including legumes that supply human dietary protein needs across many parts of the globe. We present and compare draft genome assemblies for three legume-infecting formae speciales (ff. spp.): F. oxysporum f. sp. ciceris (Foc-38-1) and f. sp. pisi (Fop-37622), significant pathogens of chickpea and pea respectively, the world's second and third most important grain legumes, and lastly f. sp. medicaginis (Fom-5190a) for which we developed a model legume pathosystem utilising Medicago truncatula. RESULTS Focusing on the identification of pathogenicity gene content, we leveraged the reference genomes of Fusarium pathogens F. oxysporum f. sp. lycopersici (tomato-infecting) and F. solani (pea-infecting) and their well-characterised core and dispensable chromosomes to predict genomic organisation in the newly sequenced legume-infecting isolates. Dispensable chromosomes are not essential for growth and in Fusarium species are known to be enriched in host-specificity and pathogenicity-associated genes. Comparative genomics of the publicly available Fusarium species revealed differential patterns of sequence conservation across F. oxysporum formae speciales, with legume-pathogenic formae speciales not exhibiting greater sequence conservation between them relative to non-legume-infecting formae speciales, possibly indicating the lack of a common ancestral source for legume pathogenicity. Combining predicted dispensable gene content with in planta expression in the model legume-infecting isolate, we identified small conserved regions and candidate effectors, four of which shared greatest similarity to proteins from another legume-infecting ff. spp. CONCLUSIONS We demonstrate that distinction of core and potential dispensable genomic regions of novel F. oxysporum genomes is an effective tool to facilitate effector discovery and the identification of gene content possibly linked to host specificity. While the legume-infecting isolates didn't share large genomic regions of pathogenicity-related content, smaller regions and candidate effector proteins were highly conserved, suggesting that they may play specific roles in inducing disease on legume hosts.
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Affiliation(s)
- Angela H Williams
- The Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
- CSIRO Agriculture, Centre for Environment and Life Sciences, Wembley, WA, 6913, Australia.
| | - Mamta Sharma
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Greater Hyderabad, 502324, Telangana, India.
| | - Louise F Thatcher
- CSIRO Agriculture, Centre for Environment and Life Sciences, Wembley, WA, 6913, Australia.
| | - Sarwar Azam
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Greater Hyderabad, 502324, Telangana, India.
| | - James K Hane
- CSIRO Agriculture, Centre for Environment and Life Sciences, Wembley, WA, 6913, Australia.
- Department of Environment and Agriculture, Curtin Institute for Computation, and CCDM Bioinformatics, Centre for Crop and Disease Management, Curtin University, Perth, WA, 6102, Australia.
| | - Jana Sperschneider
- CSIRO Agriculture, Centre for Environment and Life Sciences, Wembley, WA, 6913, Australia.
| | - Brendan N Kidd
- CSIRO Agriculture, Centre for Environment and Life Sciences, Wembley, WA, 6913, Australia.
| | - Jonathan P Anderson
- The Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
- CSIRO Agriculture, Centre for Environment and Life Sciences, Wembley, WA, 6913, Australia.
| | - Raju Ghosh
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Greater Hyderabad, 502324, Telangana, India.
| | - Gagan Garg
- CSIRO Agriculture, Centre for Environment and Life Sciences, Wembley, WA, 6913, Australia.
| | - Judith Lichtenzveig
- Department of Environment and Agriculture, Pulse Pathology and Genetics, Centre for Crop and Disease Management and Curtin Institute for Computation, Curtin University, Perth, WA, 6102, Australia.
| | - H Corby Kistler
- USDA-ARS, Cereal Disease Laboratory, University of Minnesota, St Paul, MN, 55108, USA.
| | | | - Sarah Young
- The Broad Institute, Cambridge, MA, 02141, USA.
| | - Sally-Anne G Buck
- CSIRO Agriculture, Centre for Environment and Life Sciences, Wembley, WA, 6913, Australia.
| | - Lars G Kamphuis
- The Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
- CSIRO Agriculture, Centre for Environment and Life Sciences, Wembley, WA, 6913, Australia.
| | - Rachit Saxena
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Greater Hyderabad, 502324, Telangana, India.
| | - Suresh Pande
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Greater Hyderabad, 502324, Telangana, India.
| | - Li-Jun Ma
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA, 01003, USA.
| | - Rajeev K Varshney
- The Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Greater Hyderabad, 502324, Telangana, India.
| | - Karam B Singh
- The Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
- CSIRO Agriculture, Centre for Environment and Life Sciences, Wembley, WA, 6913, Australia.
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Brown NA, Urban M, Hammond-Kosack KE. The trans-kingdom identification of negative regulators of pathogen hypervirulence. FEMS Microbiol Rev 2016; 40:19-40. [PMID: 26468211 PMCID: PMC4703069 DOI: 10.1093/femsre/fuv042] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/30/2015] [Accepted: 09/03/2015] [Indexed: 01/08/2023] Open
Abstract
Modern society and global ecosystems are increasingly under threat from pathogens, which cause a plethora of human, animal, invertebrate and plant diseases. Of increasing concern is the trans-kingdom tendency for increased pathogen virulence that is beginning to emerge in natural, clinical and agricultural settings. The study of pathogenicity has revealed multiple examples of convergently evolved virulence mechanisms. Originally described as rare, but increasingly common, are interactions where a single gene deletion in a pathogenic species causes hypervirulence. This review utilised the pathogen-host interaction database (www.PHI-base.org) to identify 112 hypervirulent mutations from 37 pathogen species, and subsequently interrogates the trans-kingdom, conserved, molecular, biochemical and cellular themes that cause hypervirulence. This study investigates 22 animal and 15 plant pathogens including 17 bacterial and 17 fungal species. Finally, the evolutionary significance and trans-kingdom requirement for negative regulators of hypervirulence and the implication of pathogen hypervirulence and emerging infectious diseases on society are discussed.
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Affiliation(s)
- Neil A Brown
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK
| | - Martin Urban
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK
| | - Kim E Hammond-Kosack
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK
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Evolutionary formation of gene clusters by reorganization: the meleagrin/roquefortine paradigm in different fungi. Appl Microbiol Biotechnol 2015; 100:1579-1587. [PMID: 26668029 DOI: 10.1007/s00253-015-7192-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 11/18/2015] [Accepted: 11/20/2015] [Indexed: 10/22/2022]
Abstract
The biosynthesis of secondary metabolites in fungi is catalyzed by enzymes encoded by genes linked in clusters that are frequently co-regulated at the transcriptional level. Formation of gene clusters may take place by de novo assembly of genes recruited from other cellular functions, but also novel gene clusters are formed by reorganization of progenitor clusters and are distributed by horizontal gene transfer. This article reviews (i) the published information on the roquefortine/meleagrin/neoxaline gene clusters of Penicillium chrysogenum (Penicillium rubens) and the short roquefortine cluster of Penicillium roqueforti, and (ii) the correlation of the genes present in those clusters with the enzymes and metabolites derived from these pathways. The P. chrysogenum roq/mel cluster consists of seven genes and includes a gene (roqT) encoding a 12-TMS transporter protein of the MFS family. Interestingly, the orthologous P. roquefortine gene cluster has only four genes and the roqT gene is present as a residual pseudogene that encodes only small peptides. Two of the genes present in the central region of the P. chrysogenum roq/mel cluster have been lost during the evolutionary formation of the short cluster and the order of the structural genes in the cluster has been rearranged. The two lost genes encode a N1 atom hydroxylase (nox) and a roquefortine scaffold-reorganizing oxygenase (sro). As a consequence P. roqueforti has lost the ability to convert the roquefortine-type carbon skeleton to the glandicoline/meleagrin-type scaffold and is unable to produce glandicoline B, meleagrin and neoxaline. The loss of this genetic information is not recent and occurred probably millions of years ago when a progenitor Penicillium strain got adapted to life in a few rich habitats such as cheese, fermented cereal grains or silage. P. roqueforti may be considered as a "domesticated" variant of a progenitor common to contemporary P. chrysogenum and related Penicillia.
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A Novel Type Pathway-Specific Regulator and Dynamic Genome Environments of a Solanapyrone Biosynthesis Gene Cluster in the Fungus Ascochyta rabiei. EUKARYOTIC CELL 2015; 14:1102-13. [PMID: 26342019 PMCID: PMC4621316 DOI: 10.1128/ec.00084-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 08/31/2015] [Indexed: 01/07/2023]
Abstract
Secondary metabolite genes are often clustered together and situated in particular genomic regions, like the subtelomere, that can facilitate niche adaptation in fungi. Solanapyrones are toxic secondary metabolites produced by fungi occupying different ecological niches. Full-genome sequencing of the ascomycete Ascochyta rabiei revealed a solanapyrone biosynthesis gene cluster embedded in an AT-rich region proximal to a telomere end and surrounded by Tc1/Mariner-type transposable elements. The highly AT-rich environment of the solanapyrone cluster is likely the product of repeat-induced point mutations. Several secondary metabolism-related genes were found in the flanking regions of the solanapyrone cluster. Although the solanapyrone cluster appears to be resistant to repeat-induced point mutations, a P450 monooxygenase gene adjacent to the cluster has been degraded by such mutations. Among the six solanapyrone cluster genes (sol1 to sol6), sol4 encodes a novel type of Zn(II)2Cys6 zinc cluster transcription factor. Deletion of sol4 resulted in the complete loss of solanapyrone production but did not compromise growth, sporulation, or virulence. Gene expression studies with the sol4 deletion and sol4-overexpressing mutants delimited the boundaries of the solanapyrone gene cluster and revealed that sol4 is likely a specific regulator of solanapyrone biosynthesis and appears to be necessary and sufficient for induction of the solanapyrone cluster genes. Despite the dynamic surrounding genomic regions, the solanapyrone gene cluster has maintained its integrity, suggesting important roles of solanapyrones in fungal biology.
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Cheeseman K, Ropars J, Renault P, Dupont J, Gouzy J, Branca A, Abraham AL, Ceppi M, Conseiller E, Debuchy R, Malagnac F, Goarin A, Silar P, Lacoste S, Sallet E, Bensimon A, Giraud T, Brygoo Y. Multiple recent horizontal transfers of a large genomic region in cheese making fungi. Nat Commun 2015; 5:2876. [PMID: 24407037 PMCID: PMC3896755 DOI: 10.1038/ncomms3876] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 11/06/2013] [Indexed: 02/01/2023] Open
Abstract
While the extent and impact of horizontal transfers in prokaryotes are widely acknowledged, their importance to the eukaryotic kingdom is unclear and thought by many to be anecdotal. Here we report multiple recent transfers of a huge genomic island between Penicillium spp. found in the food environment. Sequencing of the two leading filamentous fungi used in cheese making, P. roqueforti and P. camemberti, and comparison with the penicillin producer P. rubens reveals a 575 kb long genomic island in P. roqueforti—called Wallaby—present as identical fragments at non-homologous loci in P. camemberti and P. rubens. Wallaby is detected in Penicillium collections exclusively in strains from food environments. Wallaby encompasses about 250 predicted genes, some of which are probably involved in competition with microorganisms. The occurrence of multiple recent eukaryotic transfers in the food environment provides strong evidence for the importance of this understudied and probably underestimated phenomenon in eukaryotes. Horizontal gene transfers are known to play an important role in prokaryote evolution but their impact and prevalence in eukaryotes is less clear. Here, the authors sequence the genomes of cheese making fungi P. roqueforti and P. camemberti, and provide evidence for recent horizontal transfers of a large genomic region.
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Affiliation(s)
- Kevin Cheeseman
- INRA, UMR1319 Micalis, F-78352 Jouy-en-Josas, France; Genomic Vision, 80-84 rue des Meuniers, 92220 Bagneux, France; AgroParisTech, UMR Micalis, F-78352 Jouy-en-Josas, France
| | - Jeanne Ropars
- Origine, Structure, Evolution de la Biodiversité, UMR 7205 CNRS-MNHN, Muséum National d'Histoire Naturelle, CP39, 57 rue Cuvier, 75231 Paris Cedex 05, France; Univ Paris-Sud, Ecologie, Systématique et Evolution, UMR8079, 91405 Orsay, France; CNRS, Ecologie, Systématique et Evolution, UMR8079, 91405 Orsay, France
| | - Pierre Renault
- INRA, UMR1319 Micalis, F-78352 Jouy-en-Josas, France; AgroParisTech, UMR Micalis, F-78352 Jouy-en-Josas, France
| | - Joëlle Dupont
- Origine, Structure, Evolution de la Biodiversité, UMR 7205 CNRS-MNHN, Muséum National d'Histoire Naturelle, CP39, 57 rue Cuvier, 75231 Paris Cedex 05, France
| | - Jérôme Gouzy
- LIMP Toulouse, INRA/CNRS, INRA, 24 Chemin de Borde Rouge-Auzeville, CS 52627, 31326 Castanet-Tolosan Cedex, France; INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR441, F-31326 Castanet-Tolosan, France; CNRS, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR2594, F-31326 Castanet-Tolosan, France
| | - Antoine Branca
- Univ Paris-Sud, Ecologie, Systématique et Evolution, UMR8079, 91405 Orsay, France; CNRS, Ecologie, Systématique et Evolution, UMR8079, 91405 Orsay, France
| | - Anne-Laure Abraham
- INRA, UMR1319 Micalis, F-78352 Jouy-en-Josas, France; AgroParisTech, UMR Micalis, F-78352 Jouy-en-Josas, France
| | - Maurizio Ceppi
- Genomic Vision, 80-84 rue des Meuniers, 92220 Bagneux, France
| | | | - Robert Debuchy
- Univ Paris-Sud, Institut de Génétique et Microbiologie, UMR8621, 91405 Orsay, France; CNRS, Institut de Génétique et Microbiologie UMR8621, 91405 Orsay, France
| | - Fabienne Malagnac
- Univ Paris-Sud, Institut de Génétique et Microbiologie, UMR8621, 91405 Orsay, France; Univ Paris Diderot, Sorbonne Paris Cité, Institut des Energies de Demain (IED), 75205 Paris, France
| | - Anne Goarin
- Univ Paris-Sud, Institut de Génétique et Microbiologie, UMR8621, 91405 Orsay, France
| | - Philippe Silar
- Univ Paris-Sud, Institut de Génétique et Microbiologie, UMR8621, 91405 Orsay, France; Univ Paris Diderot, Sorbonne Paris Cité, Institut des Energies de Demain (IED), 75205 Paris, France
| | - Sandrine Lacoste
- Origine, Structure, Evolution de la Biodiversité, UMR 7205 CNRS-MNHN, Muséum National d'Histoire Naturelle, CP39, 57 rue Cuvier, 75231 Paris Cedex 05, France
| | - Erika Sallet
- LIMP Toulouse, INRA/CNRS, INRA, 24 Chemin de Borde Rouge-Auzeville, CS 52627, 31326 Castanet-Tolosan Cedex, France; INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR441, F-31326 Castanet-Tolosan, France; CNRS, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR2594, F-31326 Castanet-Tolosan, France
| | - Aaron Bensimon
- Genomic Vision, 80-84 rue des Meuniers, 92220 Bagneux, France
| | - Tatiana Giraud
- Univ Paris-Sud, Ecologie, Systématique et Evolution, UMR8079, 91405 Orsay, France; CNRS, Ecologie, Systématique et Evolution, UMR8079, 91405 Orsay, France
| | - Yves Brygoo
- 13 ruelle d'Aigrefoin 78470 St Rémy-lès-Chevreuse
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Pusztahelyi T, Holb IJ, Pócsi I. Secondary metabolites in fungus-plant interactions. FRONTIERS IN PLANT SCIENCE 2015; 6:573. [PMID: 26300892 PMCID: PMC4527079 DOI: 10.3389/fpls.2015.00573] [Citation(s) in RCA: 254] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Accepted: 07/13/2015] [Indexed: 05/18/2023]
Abstract
Fungi and plants are rich sources of thousands of secondary metabolites. The genetically coded possibilities for secondary metabolite production, the stimuli of the production, and the special phytotoxins basically determine the microscopic fungi-host plant interactions and the pathogenic lifestyle of fungi. The review introduces plant secondary metabolites usually with antifungal effect as well as the importance of signaling molecules in induced systemic resistance and systemic acquired resistance processes. The review also concerns the mimicking of plant effector molecules like auxins, gibberellins and abscisic acid by fungal secondary metabolites that modulate plant growth or even can subvert the plant defense responses such as programmed cell death to gain nutrients for fungal growth and colonization. It also looks through the special secondary metabolite production and host selective toxins of some significant fungal pathogens and the plant response in form of phytoalexin production. New results coming from genome and transcriptional analyses in context of selected fungal pathogens and their hosts are also discussed.
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Affiliation(s)
- Tünde Pusztahelyi
- Central Laboratory, Faculty of Agricultural and Food Sciences and Environmental Management, University of DebrecenDebrecen, Hungary
| | - Imre J. Holb
- Faculty of Agricultural and Food Sciences and Environmental Management, Institute of Horticulture, University of DebrecenDebrecen, Hungary
- Department of Plant Pathology, Centre for Agricultural Research, Plant Protection Institute, Hungarian Academy of SciencesDebrecen, Hungary
| | - István Pócsi
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of DebrecenDebrecen, Hungary
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Zhang H, Feng J, Manolii VP, Strelkov SE, Hwang SF. Characterization of a Gene Identified in Pathotype 5 of the Clubroot Pathogen Plasmodiophora brassicae. PHYTOPATHOLOGY 2015; 105:764-70. [PMID: 25689519 DOI: 10.1094/phyto-10-14-0270-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Clubroot caused by Plasmodiophora brassicae is an important disease of crucifers worldwide. Isolates of the pathogen can be classified into pathotypes according to their pathogenicity on differential hosts. In this study, the presence or absence of all database-available nonhousekeeping P. brassicae genes (118 in total) were assessed by polymerase chain reaction (PCR) analysis in isolates belonging to five P. brassicae pathotypes (2, 3, 5, 6, and 8 according to Williams' differential set). One gene, designated Cr811, was present exclusively in the isolate of pathotype 5. This was further confirmed by dot blot hybridization and by PCR using alternative DNA preparations and primers. Reverse transcription quantitative PCR analysis indicated that in planta expression of Cr811 was up-regulated during canola infection, especially in the stage of secondary plasmodia. Primers specific to Cr811 could distinguish a field isolate of P. brassicae belonging to pathotype 5 from two other field isolates representing pathotypes 3 and 8. These findings suggest that Cr811 is a gene that is potentially involved in clubroot pathogenesis and that it also might serve as a molecular marker for differentiation of pathotype 5 from other pathotypes.
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Affiliation(s)
- H Zhang
- First author: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China; first, second, and fifth authors: Crop Diversification Centre North, Alberta Agriculture and Rural Development, Edmonton, AB, T5Y 6H3, Canada; and first, third, and fourth authors: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - J Feng
- First author: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China; first, second, and fifth authors: Crop Diversification Centre North, Alberta Agriculture and Rural Development, Edmonton, AB, T5Y 6H3, Canada; and first, third, and fourth authors: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - V P Manolii
- First author: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China; first, second, and fifth authors: Crop Diversification Centre North, Alberta Agriculture and Rural Development, Edmonton, AB, T5Y 6H3, Canada; and first, third, and fourth authors: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - S E Strelkov
- First author: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China; first, second, and fifth authors: Crop Diversification Centre North, Alberta Agriculture and Rural Development, Edmonton, AB, T5Y 6H3, Canada; and first, third, and fourth authors: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - S-F Hwang
- First author: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China; first, second, and fifth authors: Crop Diversification Centre North, Alberta Agriculture and Rural Development, Edmonton, AB, T5Y 6H3, Canada; and first, third, and fourth authors: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
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Wu B, Buljic A, Hao W. Extensive Horizontal Transfer and Homologous Recombination Generate Highly Chimeric Mitochondrial Genomes in Yeast. Mol Biol Evol 2015; 32:2559-70. [PMID: 26018571 DOI: 10.1093/molbev/msv127] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The frequency of horizontal gene transfer (HGT) in mitochondrial DNA varies substantially. In plants, HGT is relatively common, whereas in animals it appears to be quite rare. It is of considerable importance to understand mitochondrial HGT across the major groups of eukaryotes at a genome-wide level, but so far this has been well studied only in plants. In this study, we generated ten new mitochondrial genome sequences and analyzed 40 mitochondrial genomes from the Saccharomycetaceae to assess the magnitude and nature of mitochondrial HGT in yeasts. We provide evidence for extensive, homologous-recombination-mediated, mitochondrial-to-mitochondrial HGT occurring throughout yeast mitochondrial genomes, leading to genomes that are highly chimeric evolutionarily. This HGT has led to substantial intraspecific polymorphism in both sequence content and sequence divergence, which to our knowledge has not been previously documented in any mitochondrial genome. The unexpectedly high frequency of mitochondrial HGT in yeast may be driven by frequent mitochondrial fusion, relatively low mitochondrial substitution rates and pseudohyphal fusion to produce heterokaryons. These findings suggest that mitochondrial HGT may play an important role in genome evolution of a much broader spectrum of eukaryotes than previously appreciated and that there is a critical need to systematically study the frequency, extent, and importance of mitochondrial HGT across eukaryotes.
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Affiliation(s)
- Baojun Wu
- Department of Biological Sciences, Wayne State University
| | - Adnan Buljic
- Department of Biological Sciences, Wayne State University
| | - Weilong Hao
- Department of Biological Sciences, Wayne State University
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Shoji JY, Charlton ND, Yi M, Young CA, Craven KD. Vegetative hyphal fusion and subsequent nuclear behavior in Epichloë grass endophytes. PLoS One 2015; 10:e0121875. [PMID: 25837972 PMCID: PMC4383479 DOI: 10.1371/journal.pone.0121875] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 02/18/2015] [Indexed: 01/18/2023] Open
Abstract
Epichloë species (including the former genus Neotyphodium) are fungal symbionts of many agronomically important forage grasses, and provide their grass hosts with protection from a wide range of biotic and abiotic stresses. Epichloë species include many interspecific hybrids with allodiploid-like genomes, which may provide the potential for combined traits or recombination to generate new traits. Though circumstantial evidence suggests that such interspecific hybrids might have arisen from nuclear fusion events following vegetative hyphal fusion between different Epichloë strains, this hypothesis has not been addressed empirically. Here, we investigated vegetative hyphal fusion and subsequent nuclear behavior in Epichloë species. A majority of Epichloë strains, especially those having a sexual stage, underwent self vegetative hyphal fusion. Vegetative fusion also occurred between two hyphae from different Epichloë strains. Though Epichloë spp. are uninucleate fungi, hyphal fusion resulted in two nuclei stably sharing the same cytoplasm, which might ultimately lead to nuclear fusion. In addition, protoplast fusion experiments gave rise to uninucleate putative hybrids, which apparently had two markers, one from each parent within the same nucleus. These results are consistent with the notion that interspecific hybrids arise from vegetative hyphal fusion. However, we also discuss additional factors, such as post-hybridization selection, that may be important to explain the recognized prevalence of hybrids in Epichloë species.
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Affiliation(s)
- Jun-ya Shoji
- The Samuel Roberts Noble Foundation, Plant Biology Division, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401, United States of America
| | - Nikki D. Charlton
- The Samuel Roberts Noble Foundation, Forage Improvement Division, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401, United States of America
| | - Mihwa Yi
- The Samuel Roberts Noble Foundation, Forage Improvement Division, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401, United States of America
| | - Carolyn A. Young
- The Samuel Roberts Noble Foundation, Forage Improvement Division, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401, United States of America
| | - Kelly D. Craven
- The Samuel Roberts Noble Foundation, Plant Biology Division, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401, United States of America
- * E-mail:
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Chaib De Mares M, Hess J, Floudas D, Lipzen A, Choi C, Kennedy M, Grigoriev IV, Pringle A. Horizontal transfer of carbohydrate metabolism genes into ectomycorrhizal Amanita. THE NEW PHYTOLOGIST 2015; 205:1552-1564. [PMID: 25407899 DOI: 10.1111/nph.13140] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 09/24/2014] [Indexed: 06/04/2023]
Abstract
The genus Amanita encompasses both symbiotic, ectomycorrhizal fungi and asymbiotic litter decomposers; all species are derived from asymbiotic ancestors. Symbiotic species are no longer able to degrade plant cell walls. The carbohydrate esterases family 1 (CE1s) is a diverse group of enzymes involved in carbon metabolism, including decomposition and carbon storage. CE1 genes of the ectomycorrhizal A. muscaria appear diverged from all other fungal homologues, and more similar to CE1s of bacteria, suggesting a horizontal gene transfer (HGT) event. In order to test whether AmanitaCE1s were acquired horizontally, we built a phylogeny of CE1s collected from across the tree of life, and describe the evolution of CE1 genes among Amanita and relevant lineages of bacteria. CE1s of symbiotic Amanita were very different from CE1s of asymbiotic Amanita, and are more similar to bacterial CE1s. The protein structure of one CE1 gene of A. muscaria matched a depolymerase that degrades the carbon storage molecule poly((R)-3-hydroxybutyrate) (PHB). Asymbiotic Amanita do not carry sequence or structural homologues of these genes. The CE1s acquired through HGT may enable novel metabolisms, or play roles in signaling or defense. This is the first evidence for the horizontal transfer of carbohydrate metabolism genes into ectomycorrhizal fungi.
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Affiliation(s)
- Maryam Chaib De Mares
- Department of Microbial Ecology, University of Groningen, 9747 AG, Groningen, the Netherlands
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Jaqueline Hess
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
- Department of Biosciences, University of Oslo, 0371, Oslo, Norway
| | | | - Anna Lipzen
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Cindy Choi
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Megan Kennedy
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Igor V Grigoriev
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Anne Pringle
- Harvard Forest, 324 North Main Street, Petersham, MA, 01366, USA
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McMullan M, Gardiner A, Bailey K, Kemen E, Ward BJ, Cevik V, Robert-Seilaniantz A, Schultz-Larsen T, Balmuth A, Holub E, van Oosterhout C, Jones JDG. Evidence for suppression of immunity as a driver for genomic introgressions and host range expansion in races of Albugo candida, a generalist parasite. eLife 2015; 4. [PMID: 25723966 PMCID: PMC4384639 DOI: 10.7554/elife.04550] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 02/26/2015] [Indexed: 12/13/2022] Open
Abstract
How generalist parasites with wide host ranges can evolve is a central question in parasite evolution. Albugo candida is an obligate biotrophic parasite that consists of many physiological races that each specialize on distinct Brassicaceae host species. By analyzing genome sequence assemblies of five isolates, we show they represent three races that are genetically diverged by ∼1%. Despite this divergence, their genomes are mosaic-like, with ∼25% being introgressed from other races. Sequential infection experiments show that infection by adapted races enables subsequent infection of hosts by normally non-infecting races. This facilitates introgression and the exchange of effector repertoires, and may enable the evolution of novel races that can undergo clonal population expansion on new hosts. We discuss recent studies on hybridization in other eukaryotes such as yeast, Heliconius butterflies, Darwin's finches, sunflowers and cichlid fishes, and the implications of introgression for pathogen evolution in an agro-ecological environment.
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Affiliation(s)
| | | | - Kate Bailey
- The Sainsbury Laboratory, Norwich, United Kingdom
| | - Eric Kemen
- Max Planck Research Group Fungal Biodiversity, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Ben J Ward
- School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
| | - Volkan Cevik
- The Sainsbury Laboratory, Norwich, United Kingdom
| | | | - Torsten Schultz-Larsen
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Eric Holub
- Warwick Crop Centre, University of Warwick, School of Life Sciences, Warwick, United Kingdom
| | - Cock van Oosterhout
- School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
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Identification of horizontally transferred genes in the genus Colletotrichum reveals a steady tempo of bacterial to fungal gene transfer. BMC Genomics 2015; 16:2. [PMID: 25555398 PMCID: PMC4320630 DOI: 10.1186/1471-2164-16-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 12/08/2014] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Horizontal gene transfer (HGT) is the stable transmission of genetic material between organisms by means other than vertical inheritance. HGT has an important role in the evolution of prokaryotes but is relatively rare in eukaryotes. HGT has been shown to contribute to virulence in eukaryotic pathogens. We studied the importance of HGT in plant pathogenic fungi by identifying horizontally transferred genes in the genomes of three members of the genus Colletotrichum. RESULTS We identified eleven HGT events from bacteria into members of the genus Colletotrichum or their ancestors. The HGT events include genes involved in amino acid, lipid and sugar metabolism as well as lytic enzymes. Additionally, the putative minimal dates of transference were calculated using a time calibrated phylogenetic tree. This analysis reveals a constant flux of genes from bacteria to fungi throughout the evolution of subphylum Pezizomycotina. CONCLUSIONS Genes that are typically transferred by HGT are those that are constantly subject to gene duplication and gene loss. The functions of some of these genes suggest roles in niche adaptation and virulence. We found no evidence of a burst of HGT events coinciding with major geological events. In contrast, HGT appears to be a constant, albeit rare phenomenon in the Pezizomycotina, occurring at a steady rate during their evolution.
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Chooi YH, Solomon PS. A chemical ecogenomics approach to understand the roles of secondary metabolites in fungal cereal pathogens. Front Microbiol 2014; 5:640. [PMID: 25477876 PMCID: PMC4237128 DOI: 10.3389/fmicb.2014.00640] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 11/06/2014] [Indexed: 11/19/2022] Open
Abstract
Secondary metabolites (SMs) are known to play important roles in the virulence and lifestyle of fungal plant pathogens. The increasing availability of fungal pathogen genome sequences and next-generation genomic tools have allowed us to survey the SM gene cluster inventory in individual fungi. Thus, there is immense opportunity for SM discovery in these plant pathogens. Comparative genomics and transcriptomics have been employed to obtain insights on the genetic features that enable fungal pathogens to adapt in individual ecological niches and to adopt the different pathogenic lifestyles. Here, we will discuss how we can use these tools to search for ecologically important SM gene clusters in fungi, using cereal pathogens as models. This ecological genomics approach, combined with genome mining and chemical ecology tools, is likely to advance our understanding of the natural functions of SMs and accelerate bioactive molecule discovery.
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Affiliation(s)
- Yit-Heng Chooi
- Plant Sciences Division, Research School of Biology, The Australian National University Canberra, ACT, Australia
| | - Peter S Solomon
- Plant Sciences Division, Research School of Biology, The Australian National University Canberra, ACT, Australia
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75
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Trajectory and genomic determinants of fungal-pathogen speciation and host adaptation. Proc Natl Acad Sci U S A 2014; 111:16796-801. [PMID: 25368161 DOI: 10.1073/pnas.1412662111] [Citation(s) in RCA: 198] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Much remains unknown regarding speciation. Host-pathogen interactions are a major driving force for diversification, but the genomic basis for speciation and host shifting remains unclear. The fungal genus Metarhizium contains species ranging from specialists with very narrow host ranges to generalists that attack a wide range of insects. By genomic analyses of seven species, we demonstrated that generalists evolved from specialists via transitional species with intermediate host ranges and that this shift paralleled insect evolution. We found that specialization was associated with retention of sexuality and rapid evolution of existing protein sequences whereas generalization was associated with protein-family expansion, loss of genome-defense mechanisms, genome restructuring, horizontal gene transfer, and positive selection that accelerated after reinforcement of reproductive isolation. These results advance understanding of speciation and genomic signatures that underlie pathogen adaptation to hosts.
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76
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Widespread horizontal transfer of the cerato-ulmin gene between Ophiostoma novo-ulmi and Geosmithia species. Fungal Biol 2014; 118:663-74. [DOI: 10.1016/j.funbio.2014.04.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 04/02/2014] [Accepted: 04/13/2014] [Indexed: 01/23/2023]
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77
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Kusaba M, Mochida T, Naridomi T, Fujita Y, Chuma I, Tosa Y. Loss of a 1.6 Mb chromosome in Pyricularia oryzae harboring two alleles of AvrPik leads to acquisition of virulence to rice cultivars containing resistance alleles at the Pik locus. Curr Genet 2014; 60:315-25. [PMID: 25056242 DOI: 10.1007/s00294-014-0437-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 07/01/2014] [Accepted: 07/07/2014] [Indexed: 11/28/2022]
Abstract
A small and extra chromosome of 1.6 Mb was previously identified in a Pyricularia oryzae strain, 84R-62B. To understand a role of the 1.6 Mb chromosome in the pathogenic changeability of P. oryzae, we performed experiments designed to characterize the 1.6 Mb chromosome in the present study. A gene family encoding secreted protein Pex31s in P. oryzae consists of five homologs, Pex31-A to -E. Among them, Pex31-A and -D are known to be recognized by Pik-m and Pik/Pik-m/Pik-p, respectively. In the present study, we identified Pex31-A and -D in the genome of 84R-62B. Segregation analyses using an F1 population between 84R-62B and another rice blast strain, Y93-245c-2, revealed a strong linkage between the two homologs and the 1.6 Mb chromosome of 84R-62B. A CHEF-Southern analysis revealed an association between the 1.6 Mb chromosome and the homologs, indicating that both homologs are located on the 1.6 Mb chromosome of 84R-62B. The loss of the 1.6 Mb chromosome was observed in subcultures of a F1 progeny, F1-327. These subcultures concomitantly acquired virulence on Pik, Pik-m, and Pik-p. The present study is the first report showing that loss of a small and extra chromosome leads to pathogenic mutation of P. oryzae and may provide a new insight into the mechanisms generating pathogenic variation of this fungus.
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Affiliation(s)
- Motoaki Kusaba
- Laboratory of Plant Pathology, Faculty of Agriculture, Saga University, Saga, Saga, 840-8502, Japan,
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78
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Schuck S, Weinhold A, Luu VT, Baldwin IT. Isolating fungal pathogens from a dynamic disease outbreak in a native plant population to establish plant-pathogen bioassays for the ecological model plant Nicotiana attenuata. PLoS One 2014; 9:e102915. [PMID: 25036191 PMCID: PMC4103856 DOI: 10.1371/journal.pone.0102915] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 06/25/2014] [Indexed: 11/19/2022] Open
Abstract
The wild tobacco species Nicotiana attenuata has been intensively used as a model plant to study its interaction with insect herbivores and pollinators in nature, however very little is known about its native pathogen community. We describe a fungal disease outbreak in a native N. attenuata population comprising 873 plants growing in an area of about 1500 m2. The population was divided into 14 subpopulations and disease symptom development in the subpopulations was monitored for 16 days, revealing a waxing and waning of visible disease symptoms with some diseased plants recovering fully. Native fungal N. attenuata pathogens were isolated from diseased plants, characterized genetically, chemotaxonomically and morphologically, revealing several isolates of the ascomycete genera Fusarium and Alternaria, that differed in the type and strength of the disease symptoms they caused in bioassays on either detached leaves or intact soil-grown plants. These isolates and the bioassays will empower the study of N. attenuata-pathogen interactions in a realistic ecological context.
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Affiliation(s)
- Stefan Schuck
- Max Planck Institute for Chemical Ecology, Department of Molecular Ecology, Jena, Germany
| | - Arne Weinhold
- Max Planck Institute for Chemical Ecology, Department of Molecular Ecology, Jena, Germany
| | - Van Thi Luu
- Max Planck Institute for Chemical Ecology, Department of Molecular Ecology, Jena, Germany
| | - Ian T. Baldwin
- Max Planck Institute for Chemical Ecology, Department of Molecular Ecology, Jena, Germany
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79
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Chagnon PL. Ecological and evolutionary implications of hyphal anastomosis in arbuscular mycorrhizal fungi. FEMS Microbiol Ecol 2014; 88:437-44. [DOI: 10.1111/1574-6941.12321] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 03/05/2014] [Accepted: 03/06/2014] [Indexed: 01/10/2023] Open
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80
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Barcelos QL, Pinto JMA, Vaillancourt LJ, Souza EA. Characterization of Glomerella strains recovered from anthracnose lesions on common bean plants in Brazil. PLoS One 2014; 9:e90910. [PMID: 24633173 PMCID: PMC3954623 DOI: 10.1371/journal.pone.0090910] [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: 11/24/2013] [Accepted: 02/04/2014] [Indexed: 11/19/2022] Open
Abstract
Anthracnose caused by Colletotrichum lindemuthianum is an important disease of common bean, resulting in major economic losses worldwide. Genetic diversity of the C. lindemuthianum population contributes to its ability to adapt rapidly to new sources of host resistance. The origin of this diversity is unknown, but sexual recombination, via the Glomerella teleomorph, is one possibility. This study tested the hypothesis that Glomerella strains that are frequently recovered from bean anthracnose lesions represent the teleomorph of C. lindemuthianum. A large collection of Glomerella isolates could be separated into two groups based on phylogenetic analysis, morphology, and pathogenicity to beans. Both groups were unrelated to C. lindemuthianum. One group clustered with the C. gloeosporioides species complex and produced mild symptoms on bean tissues. The other group, which belonged to a clade that included the cucurbit anthracnose pathogen C. magna, caused no symptoms. Individual ascospores recovered from Glomerella perithecia gave rise to either fertile (perithecial) or infertile (conidial) colonies. Some pairings of perithecial and conidial strains resulted in induced homothallism in the conidial partner, while others led to apparent heterothallic matings. Pairings involving two perithecial, or two conidial, colonies produced neither outcome. Conidia efficiently formed conidial anastomosis tubes (CATs), but ascospores never formed CATs. The Glomerella strains formed appressoria and hyphae on the plant surface, but did not penetrate or form infection structures within the tissues. Their behavior was similar whether the beans were susceptible or resistant to anthracnose. These same Glomerella strains produced thick intracellular hyphae, and eventually acervuli, if host cell death was induced. When Glomerella was co-inoculated with C. lindemuthianum, it readily invaded anthracnose lesions. Thus, the hypothesis was not supported: Glomerella strains from anthracnose lesions do not represent the teleomorphic phase of C. lindemuthianum, and instead appear to be bean epiphytes that opportunistically invade and sporulate in the lesions.
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Affiliation(s)
- Quélen L. Barcelos
- Departamento de Biologia, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
| | - Joyce M. A. Pinto
- Empresa Brasileira de Pesquisa Agropecuária (Embrapa), Sinop, Mato Grosso, Brazil
| | - Lisa J. Vaillancourt
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Elaine A. Souza
- Departamento de Biologia, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
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81
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Abstract
Gene transfer has been identified as a prevalent and pervasive phenomenon and an important source of genomic innovation in bacteria. The role of gene transfer in microbial eukaryotes seems to be of a reduced magnitude but in some cases can drive important evolutionary innovations, such as new functions that underpin the colonization of different niches. The aim of this review is to summarize published cases that support the hypothesis that horizontal gene transfer (HGT) has played a role in the evolution of phytopathogenic traits in fungi and oomycetes. Our survey of the literature identifies 46 proposed cases of transfer of genes that have a putative or experimentally demonstrable phytopathogenic function. When considering the life-cycle steps through which a pathogen must progress, the majority of the HGTs identified are associated with invading, degrading, and manipulating the host. Taken together, these data suggest HGT has played a role in shaping how fungi and oomycetes colonize plant hosts.
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Affiliation(s)
- Darren Soanes
- Biosciences, University of Exeter, Exeter, EX4 4QD, United Kingdom;
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82
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Genetic structure of Pyrenophora teres net and spot populations as revealed by microsatellite analysis. Fungal Biol 2013; 118:180-92. [PMID: 24528640 DOI: 10.1016/j.funbio.2013.11.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 11/08/2013] [Accepted: 11/18/2013] [Indexed: 11/22/2022]
Abstract
The population structure of the fungal pathogen Pyrenophora teres, collected mainly from different regions of the Czech and Slovak Republics, was examined using a microsatellite analyses (SSR). Among 305 P. teres f. teres (PTT) and 82 P. teres f. maculata (PTM) isolates that were collected, the overall gene diversity was similar (ĥ = 0.12 and ĥ = 0.13, respectively). A high level of genetic differentiation (FST = 0.46; P < 0.001) indicated the existence of population structure. Nine clusters that were found using a Bayesian approach represent the genetic structure of the studied P. teres populations. Two clusters consisted of PTM populations; PTT populations formed another seven clusters. An exact test of population differentiation confirmed the results that were generated by Structure. There was no difference between naturally infected populations over time, and genetic distance did not correlate with geographical distance. The facts that all individuals had unique multilocus genotypes and that the hypothesis of random mating could not be rejected in several populations or subpopulations serve as evidence that a mixed mating system plays a role in the P. teres life cycle. Despite the fact that the genetic differentiation value between PTT and PTM (FST = 0.30; P < 0.001) is lower than it is between the populations within each form (FST = 0.40 (PTT); FST = 0.35 (PTM); P < 0.001) and that individuals with mixed PTT and PTM genomes were found, the two forms of P. teres form genetically separate populations. Therefore, it can be assumed that these populations have most likely undergone speciation.
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83
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Gao C, Ren X, Mason AS, Liu H, Xiao M, Li J, Fu D. Horizontal gene transfer in plants. Funct Integr Genomics 2013; 14:23-9. [PMID: 24132513 DOI: 10.1007/s10142-013-0345-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2013] [Revised: 10/03/2013] [Accepted: 10/07/2013] [Indexed: 01/12/2023]
Abstract
Horizontal gene transfer (HGT) describes the transmission of genetic material across species boundaries. HGT often occurs in microbic and eukaryotic genomes. However, the pathways by which HGTs occur in multicellular eukaryotes, especially in plants, are not well understood. We systematically summarized more than ten possible pathways for HGT. The intimate contact which frequently occurs in parasitism, symbiosis, pathogen, epiphyte, entophyte, and grafting interactions could promote HGTs between two species. Besides these direct transfer methods, genes can be exchanged with a vector as a bridge: possible vectors include pollen, fungi, bacteria, viruses, viroids, plasmids, transposons, and insects. HGT, especially when involving horizontal transfer of transposable elements, is recognized as a significant force propelling genomic variation and biological innovation, playing an important functional and evolutionary role in both eukaryotic and prokaryotic genomes. We proposed possible mechanisms by which HGTs can occur, which is useful in understanding the genetic information exchange among distant species or distant cellular components.
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Affiliation(s)
- Caihua Gao
- Engineering Research Center of South Upland Agriculture, Ministry of Education, Southwest University, Chongqing, People's Republic of China
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84
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Gardiner DM, Kazan K, Manners JM. Cross-kingdom gene transfer facilitates the evolution of virulence in fungal pathogens. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2013; 210:151-158. [PMID: 23849122 DOI: 10.1016/j.plantsci.2013.06.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 06/03/2013] [Accepted: 06/06/2013] [Indexed: 06/02/2023]
Abstract
The constant interaction between plants and their pathogens has resulted in the evolution of a diverse array of microbial infection strategies. It is increasingly evident that horizontal acquisition of new virulence functions in fungi is one of the evolutionary processes that maintain pathogens' competitive edge over host plants. Genome analyses of fungi are pointing towards this phenomenon being particularly prevalent in the subphylum Pezizomycota. While the extent of cross-kingdom gene transfer can be determined with existing genomic tools and databases, so far very few horizontally transmitted genes have been functionally characterised, and an understanding of their physiological roles in virulence has been determined for even fewer genes. Understanding the evolutionary selection pressures that drive the retention of acquired genes in particular fungal lineages is important, as it will undoubtedly reveal new insights into both fungal virulence mechanisms and corresponding plant defence processes in the future.
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Affiliation(s)
- Donald M Gardiner
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Plant Industry, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, Brisbane, Queensland 4067, Australia.
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85
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Proctor RH, Van Hove F, Susca A, Stea G, Busman M, van der Lee T, Waalwijk C, Moretti A, Ward TJ. Birth, death and horizontal transfer of the fumonisin biosynthetic gene cluster during the evolutionary diversification of Fusarium. Mol Microbiol 2013; 90:290-306. [PMID: 23937442 DOI: 10.1111/mmi.12362] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2013] [Indexed: 01/15/2023]
Abstract
Fumonisins are a family of carcinogenic secondary metabolites produced by members of the Fusarium fujikuroi species complex (FFSC) and rare strains of Fusarium oxysporum. In Fusarium, fumonisin biosynthetic genes (FUM) are clustered, and the cluster is uniform in gene organization. Here, sequence analyses indicated that the cluster exists in five different genomic contexts, defining five cluster types. In FUM gene genealogies, evolutionary relationships between fusaria with different cluster types were largely incongruent with species relationships inferred from primary-metabolism (PM) gene genealogies, and FUM cluster types are not trans-specific. In addition, synonymous site divergence analyses indicated that three FUM cluster types predate diversification of FFSC. The data are not consistent with balancing selection or interspecific hybridization, but they are consistent with two competing hypotheses: (i) multiple horizontal transfers of the cluster from unknown donors to FFSC recipients and (ii) cluster duplication and loss (birth and death). Furthermore, low levels of FUM gene divergence in F. bulbicola, an FFSC species, and F. oxysporum provide evidence for horizontal transfer of the cluster from the former, or a closely related species, to the latter. Thus, uniform gene organization within the FUM cluster belies a complex evolutionary history that has not always paralleled the evolution of Fusarium.
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Affiliation(s)
- Robert H Proctor
- United States Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, Peoria, IL, USA
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86
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Burmester A, Karimi S, Wetzel J, Wöstemeyer J. Complementation of a stable Met2-1 mutant of the zygomycete Absidia glauca by the corresponding wild-type allele of the mycoparasite Parasitella parasitica, transferred during infection. Microbiology (Reading) 2013; 159:1639-1648. [DOI: 10.1099/mic.0.066910-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Anke Burmester
- General Microbiology and Microbe Genetics, Friedrich-Schiller University Jena, Neugasse 24, D-07743 Jena, Germany
| | - Sedighe Karimi
- General Microbiology and Microbe Genetics, Friedrich-Schiller University Jena, Neugasse 24, D-07743 Jena, Germany
| | - Jana Wetzel
- General Microbiology and Microbe Genetics, Friedrich-Schiller University Jena, Neugasse 24, D-07743 Jena, Germany
| | - Johannes Wöstemeyer
- General Microbiology and Microbe Genetics, Friedrich-Schiller University Jena, Neugasse 24, D-07743 Jena, Germany
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87
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Wight WD, Labuda R, Walton JD. Conservation of the genes for HC-toxin biosynthesis in Alternaria jesenskae. BMC Microbiol 2013; 13:165. [PMID: 23865912 PMCID: PMC3729494 DOI: 10.1186/1471-2180-13-165] [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: 04/18/2013] [Accepted: 07/12/2013] [Indexed: 11/23/2022] Open
Abstract
Background HC-toxin, a cyclic tetrapeptide, is a virulence determinant for the plant pathogenic fungus Cochliobolus carbonum. It was recently discovered that another fungus, Alternaria jesenskae, also produces HC-toxin. Results The major genes (collectively known as AjTOX2) involved in the biosynthesis of HC-toxin were identified from A. jesenskae by genomic sequencing. The encoded orthologous proteins share 75-85% amino acid identity, and the genes for HC-toxin biosynthesis are duplicated in both fungi. The genomic organization of the genes in the two fungi show a similar but not identical partial clustering arrangement. A set of representative housekeeping proteins show a similar high level of amino acid identity between C. carbonum and A. jesenskae, which is consistent with the close relatedness of these two genera within the family Pleosporaceae (Dothideomycetes). Conclusions This is the first report that the plant virulence factor HC-toxin is made by an organism other than C. carbonum. The genes may have moved by horizontal transfer between the two species, but it cannot be excluded that they were present in a common ancestor and lost from other species of Alternaria and Cochliobolus.
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Affiliation(s)
- Wanessa D Wight
- Department of Energy Plant Research Laboratory, Michigan State University, 612 Wilson Road, Room 210, East Lansing, MI 48824, USA
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88
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Balesdent MH, Fudal I, Ollivier B, Bally P, Grandaubert J, Eber F, Chèvre AM, Leflon M, Rouxel T. The dispensable chromosome of Leptosphaeria maculans shelters an effector gene conferring avirulence towards Brassica rapa. THE NEW PHYTOLOGIST 2013; 198:887-898. [PMID: 23406519 DOI: 10.1111/nph.12178] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 01/10/2013] [Indexed: 05/02/2023]
Abstract
Phytopathogenic fungi frequently contain dispensable chromosomes, some of which contribute to host range or pathogenicity. In Leptosphaeria maculans, the stem canker agent of oilseed rape (Brassica napus), the minichromosome was previously suggested to be dispensable, without evidence for any role in pathogenicity. Using genetic and genomic approaches, we investigated the inheritance and molecular determinant of an L. maculans-Brassica rapa incompatible interaction. Single gene control of the resistance was found, while all markers located on the L. maculans minichromosome, absent in the virulent parental isolate, co-segregated with the avirulent phenotype. Only one candidate avirulence gene was identified on the minichromosome, validated by complementation experiments and termed AvrLm11. The minichromosome was frequently lost following meiosis, but the frequency of isolates lacking it remained stable in field populations sampled at a 10-yr time interval, despite a yearly sexual stage in the L. maculans life cycle. This work led to the cloning of a new 'lost in the middle of nowhere' avirulence gene of L. maculans, interacting with a B. rapa resistance gene termed Rlm11 and introgressed into B. napus. It demonstrated the dispensability of the L. maculans minichromosome and suggested that its loss generates a fitness deficit.
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Affiliation(s)
- Marie-Hélène Balesdent
- INRA, UR1290 BIOGER, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France
| | - Isabelle Fudal
- INRA, UR1290 BIOGER, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France
| | - Bénédicte Ollivier
- INRA, UR1290 BIOGER, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France
| | - Pascal Bally
- INRA, UR1290 BIOGER, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France
| | - Jonathan Grandaubert
- INRA, UR1290 BIOGER, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France
| | - Frédérique Eber
- INRA, UMR1349 IGEPP, BP35327, F-35653, Le Rheu Cedex, France
| | | | - Martine Leflon
- CETIOM, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France
| | - Thierry Rouxel
- INRA, UR1290 BIOGER, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France
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89
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Sun BF, Xiao JH, He S, Liu L, Murphy RW, Huang DW. Multiple interkingdom horizontal gene transfers in Pyrenophora and closely related species and their contributions to phytopathogenic lifestyles. PLoS One 2013; 8:e60029. [PMID: 23555871 PMCID: PMC3612039 DOI: 10.1371/journal.pone.0060029] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 02/20/2013] [Indexed: 12/13/2022] Open
Abstract
Many studies have reported horizontal gene transfer (HGT) events from eukaryotes, especially fungi. However, only a few investigations summarized multiple interkingdom HGTs involving important phytopathogenic species of Pyrenophora and few have investigated the genetic contributions of HGTs to fungi. We investigated HGT events in P. teres and P. tritici-repentis and discovered that both species harbored 14 HGT genes derived from bacteria and plants, including 12 HGT genes that occurred in both species. One gene coding a leucine-rich repeat protein was present in both species of Pyrenophora and it may have been transferred from a host plant. The transfer of genes from a host plant to pathogenic fungi has been reported rarely and we discovered the first evidence for this transfer in phytopathogenic Pyrenophora. Two HGTs in Pyrenophora underwent subsequent duplications. Some HGT genes had homologs in a few other fungi, indicating relatively ancient transfer events. Functional analyses indicated that half of the HGT genes encoded extracellular proteins and these may have facilitated the infection of plants by Pyrenophora via interference with plant defense-response and the degradation of plant cell walls. Some other HGT genes appeared to participate in carbohydrate metabolism. Together, these functions implied that HGTs may have led to highly efficient mechanisms of infection as well as the utilization of host carbohydrates. Evolutionary analyses indicated that HGT genes experienced amelioration, purifying selection, and accelerated evolution. These appeared to constitute adaptations to the background genome of the recipient. The discovery of multiple interkingdom HGTs in Pyrenophora, their significance to infection, and their adaptive evolution, provided valuable insights into the evolutionary significance of interkingdom HGTs from multiple donors.
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Affiliation(s)
- Bao-Fa Sun
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Jin-Hua Xiao
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Shunmin He
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Li Liu
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Robert W. Murphy
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Centre for Biodiversity and Conservation Biology, Royal Ontario Museum, Toronto, Canada
| | - Da-Wei Huang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong, China
- * E-mail:
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90
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Schmidt SM, Houterman PM, Schreiver I, Ma L, Amyotte S, Chellappan B, Boeren S, Takken FLW, Rep M. MITEs in the promoters of effector genes allow prediction of novel virulence genes in Fusarium oxysporum. BMC Genomics 2013; 14:119. [PMID: 23432788 PMCID: PMC3599309 DOI: 10.1186/1471-2164-14-119] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 02/11/2013] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND The plant-pathogenic fungus Fusarium oxysporum f.sp.lycopersici (Fol) has accessory, lineage-specific (LS) chromosomes that can be transferred horizontally between strains. A single LS chromosome in the Fol4287 reference strain harbors all known Fol effector genes. Transfer of this pathogenicity chromosome confers virulence to a previously non-pathogenic recipient strain. We hypothesize that expression and evolution of effector genes is influenced by their genomic context. RESULTS To gain a better understanding of the genomic context of the effector genes, we manually curated the annotated genes on the pathogenicity chromosome and identified and classified transposable elements. Both retro- and DNA transposons are present with no particular overrepresented class. Retrotransposons appear evenly distributed over the chromosome, while DNA transposons tend to concentrate in large chromosomal subregions. In general, genes on the pathogenicity chromosome are dispersed within the repeat landscape. Effector genes are present within subregions enriched for DNA transposons. A miniature Impala (mimp) is always present in their promoters. Although promoter deletion studies of two effector gene loci did not reveal a direct function of the mimp for gene expression, we were able to use proximity to a mimp as a criterion to identify new effector gene candidates. Through xylem sap proteomics we confirmed that several of these candidates encode proteins secreted during plant infection. CONCLUSIONS Effector genes in Fol reside in characteristic subregions on a pathogenicity chromosome. Their genomic context allowed us to develop a method for the successful identification of novel effector genes. Since our approach is not based on effector gene similarity, but on unique genomic features, it can easily be extended to identify effector genes in Fo strains with different host specificities.
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Affiliation(s)
- Sarah M Schmidt
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands
| | - Petra M Houterman
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands
| | - Ines Schreiver
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands
- Current address: Fachgebiet Medizinische Biotechnologie, Institut für Biotechnologie, Technische Universität Berlin, Gustav-Meyer-Allee 25, Berlin, Germany
| | - Lisong Ma
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands
| | - Stefan Amyotte
- Department of Plant Pathology, University of Kentucky, 201F Plant Science Building, 1405 Veterans Drive, 40546-0312, Lexington, KY, USA
| | - Biju Chellappan
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands
| | - Sjef Boeren
- Laboratory for Biochemistry, Wageningen University, Dreijenlaan 3, 6703HA, Wageningen, the Netherlands
| | - Frank L W Takken
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands
| | - Martijn Rep
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands
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91
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Condon BJ, Leng Y, Wu D, Bushley KE, Ohm RA, Otillar R, Martin J, Schackwitz W, Grimwood J, MohdZainudin N, Xue C, Wang R, Manning VA, Dhillon B, Tu ZJ, Steffenson BJ, Salamov A, Sun H, Lowry S, LaButti K, Han J, Copeland A, Lindquist E, Barry K, Schmutz J, Baker SE, Ciuffetti LM, Grigoriev IV, Zhong S, Turgeon BG. Comparative genome structure, secondary metabolite, and effector coding capacity across Cochliobolus pathogens. PLoS Genet 2013; 9:e1003233. [PMID: 23357949 PMCID: PMC3554632 DOI: 10.1371/journal.pgen.1003233] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 11/14/2012] [Indexed: 11/17/2022] Open
Abstract
The genomes of five Cochliobolus heterostrophus strains, two Cochliobolus sativus strains, three additional Cochliobolus species (Cochliobolus victoriae, Cochliobolus carbonum, Cochliobolus miyabeanus), and closely related Setosphaeria turcica were sequenced at the Joint Genome Institute (JGI). The datasets were used to identify SNPs between strains and species, unique genomic regions, core secondary metabolism genes, and small secreted protein (SSP) candidate effector encoding genes with a view towards pinpointing structural elements and gene content associated with specificity of these closely related fungi to different cereal hosts. Whole-genome alignment shows that three to five percent of each genome differs between strains of the same species, while a quarter of each genome differs between species. On average, SNP counts among field isolates of the same C. heterostrophus species are more than 25× higher than those between inbred lines and 50× lower than SNPs between Cochliobolus species. The suites of nonribosomal peptide synthetase (NRPS), polyketide synthase (PKS), and SSP-encoding genes are astoundingly diverse among species but remarkably conserved among isolates of the same species, whether inbred or field strains, except for defining examples that map to unique genomic regions. Functional analysis of several strain-unique PKSs and NRPSs reveal a strong correlation with a role in virulence.
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Affiliation(s)
- Bradford J. Condon
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
| | - Yueqiang Leng
- Department of Plant Pathology, North Dakota State University, Fargo, North Dakota, United States of America
| | - Dongliang Wu
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
| | - Kathryn E. Bushley
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Robin A. Ohm
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Robert Otillar
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Joel Martin
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Wendy Schackwitz
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Jane Grimwood
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, United States of America
| | - NurAinIzzati MohdZainudin
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
- Department of Biology, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Chunsheng Xue
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Rui Wang
- Department of Plant Pathology, North Dakota State University, Fargo, North Dakota, United States of America
| | - Viola A. Manning
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Braham Dhillon
- Department of Forest Sciences, University of British Columbia, Vancouver, Canada
| | - Zheng Jin Tu
- Supercomputing Institute for Advanced Computational Research, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Brian J. Steffenson
- Department of Plant Pathology, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Asaf Salamov
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Hui Sun
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Steve Lowry
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Kurt LaButti
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - James Han
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Alex Copeland
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Erika Lindquist
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Kerrie Barry
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Jeremy Schmutz
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, United States of America
| | - Scott E. Baker
- Pacific Northwest National Laboratory, Richland, Washington, United States of America
| | - Lynda M. Ciuffetti
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Igor V. Grigoriev
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Shaobin Zhong
- Department of Plant Pathology, North Dakota State University, Fargo, North Dakota, United States of America
| | - B. Gillian Turgeon
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
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92
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Tsuge T, Harimoto Y, Akimitsu K, Ohtani K, Kodama M, Akagi Y, Egusa M, Yamamoto M, Otani H. Host-selective toxins produced by the plant pathogenic fungusAlternaria alternata. FEMS Microbiol Rev 2013; 37:44-66. [DOI: 10.1111/j.1574-6976.2012.00350.x] [Citation(s) in RCA: 247] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 06/14/2012] [Accepted: 07/19/2012] [Indexed: 12/19/2022] Open
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93
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Horizontal transfer and the evolution of host-pathogen interactions. INTERNATIONAL JOURNAL OF EVOLUTIONARY BIOLOGY 2012; 2012:679045. [PMID: 23227424 PMCID: PMC3513734 DOI: 10.1155/2012/679045] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 10/26/2012] [Indexed: 12/16/2022]
Abstract
Horizontal gene transfer has been long known in viruses and prokaryotes, but its importance in eukaryotes has been only acknowledged recently. Close contact between organisms, as it occurs between pathogens and their hosts, facilitates the occurrence of DNA transfer events. Once inserted in a foreign genome, DNA sequences have sometimes been coopted by pathogens to improve their survival or infectivity, or by hosts to protect themselves against the harm of pathogens. Hence, horizontal transfer constitutes a source of novel sequences that can be adopted to change the host-pathogen interactions. Therefore, horizontal transfer can have an important impact on the coevolution of pathogens and their hosts.
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94
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Milani NA, Lawrence DP, Arnold AE, VanEtten HD. Origin of pisatin demethylase (PDA) in the genus Fusarium. Fungal Genet Biol 2012; 49:933-42. [PMID: 22985693 DOI: 10.1016/j.fgb.2012.08.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Revised: 08/21/2012] [Accepted: 08/22/2012] [Indexed: 11/25/2022]
Abstract
Host specificity of plant pathogens can be dictated by genes that enable pathogens to circumvent host defenses. Upon recognition of a pathogen, plants initiate defense responses that can include the production of antimicrobial compounds such as phytoalexins. The pea pathogen Nectria haematococca mating population VI (MPVI) is a filamentous ascomycete that contains a cluster of genes known as the pea pathogenicity (PEP) cluster in which the pisatin demethylase (PDA) gene resides. The PDA gene product is responsible for the detoxification of the phytoalexin pisatin, which is produced by the pea plant (Pisum sativum L.). This detoxification activity allows the pathogen to evade the phytoalexin defense mechanism. It has been proposed that the evolution of PDA and the PEP cluster reflects horizontal gene transfer (HGT). Previous observations consistent with this hypothesis include the location of the PEP cluster and PDA gene on a dispensable portion of the genome (a supernumerary chromosome), a phylogenetically discontinuous distribution of the cluster among closely related species, and a bias in G+C content and codon usage compared to other regions of the genome. In this study we compared the phylogenetic history of PDA, beta-tubulin, and translation elongation factor 1-alpha in three closely related fungi (Nectria haematococca, Fusarium oxysporum, and Neocosmospora species) to formally evaluate hypotheses regarding the origin and evolution of PDA. Our results, coupled with previous work, robustly demonstrate discordance between the gene genealogy of PDA and the organismal phylogeny of these species, and illustrate how HGT of pathogenicity genes can contribute to the expansion of host specificity in plant-pathogenic fungi.
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Affiliation(s)
- Nicholas A Milani
- School of Plant Sciences, College of Agriculture, University of Arizona, Tucson, AZ 85721, USA
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95
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Izumi Y, Ohtani K, Miyamoto Y, Masunaka A, Fukumoto T, Gomi K, Tada Y, Ichimura K, Peever TL, Akimitsu K. A polyketide synthase gene, ACRTS2, is responsible for biosynthesis of host-selective ACR-toxin in the rough lemon pathotype of Alternaria alternata. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2012; 25:1419-1429. [PMID: 22835272 DOI: 10.1094/mpmi-06-12-0155-r] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The rough lemon pathotype of Alternaria alternata produces host-selective ACR-toxin and causes Alternaria leaf spot disease of rough lemon (Citrus jambhiri). The structure of ACR-toxin I (MW = 496) consists of a polyketide with an α-dihydropyrone ring in a 19-carbon polyalcohol. Genes responsible for toxin production were localized to a 1.5-Mb chromosome in the genome of the rough lemon pathotype. Sequence analysis of this chromosome revealed an 8,338-bp open reading frame, ACRTS2, that was present only in the genomes of ACR-toxin-producing isolates. ACRTS2 is predicted to encode a putative polyketide synthase of 2,513 amino acids and belongs to the fungal reducing type I polyketide synthases. Typical polyketide functional domains were identified in the predicted amino acid sequence, including β-ketoacyl synthase, acyl transferase, methyl transferase, dehydratase, β-ketoreductase, and phosphopantetheine attachment site domains. Combined use of homologous recombination-mediated gene disruption and RNA silencing allowed examination of the functional role of multiple paralogs in ACR-toxin production. ACRTS2 was found to be essential for ACR-toxin production and pathogenicity of the rough lemon pathotype of A. alternata.
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Affiliation(s)
- Y Izumi
- Kagawa University, Kagawa, Japan
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96
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Zuther K, Kahnt J, Utermark J, Imkampe J, Uhse S, Schirawski J. Host specificity of Sporisorium reilianum is tightly linked to generation of the phytoalexin luteolinidin by Sorghum bicolor. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2012; 25:1230-7. [PMID: 22670753 DOI: 10.1094/mpmi-12-11-0314] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The smut fungus Sporisorium reilianum occurs in two varieties (S. reilianum f. sp. reilianum and S. reilianum f. sp. zeae) that cause head smut disease on sorghum and maize, respectively. Prior to plant infection, compatible haploid sporidia of S. reilianum fuse to form infectious dikaryotic hyphae that penetrate the leaf surface, spread throughout the plant, and reach the inflorescences, in which spore formation occurs. To elucidate the basis of host specificity of the two S. reilianum varieties, we compared disease etiology of S. reilianum f. sp. reilianum and S. reilianum f. sp. zeae on sorghum and maize. Both varieties could penetrate and multiply in both hosts. However, red spots appeared on inoculated leaves after sorghum infection with S. reilianum f. sp. zeae. Using matrix-assisted laser desorption-ionization time of flight analysis of leaf extracts, we show that sorghum reacts with the production of the red and orange phytoalexins luteolinidin and apigeninidin upon colonization by S. reilianum f. sp. zeae but not by S. reilianum f. sp. reilianum. Using in vitro growth assays, we demonstrate that luteolinidin but not apigeninidin slows vegetative growth of both S. reilianum f. sp. zeae and S. reilianum f. sp. reilianum. However, the phytoalexin biosynthesis gene SbDFR3 is only induced in sorghum after infection with S. reilianum f. sp. zeae, as shown by quantitative real-time polymerase chain reaction. This suggests that regulation of luteolinidin biosynthesis determines infection success of S. reilianum on sorghum.
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Affiliation(s)
- Katja Zuther
- Georg-August-Universitat Gottingen, Gottingen, Germany
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97
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Raffaele S, Kamoun S. Genome evolution in filamentous plant pathogens: why bigger can be better. Nat Rev Microbiol 2012; 10:417-30. [PMID: 22565130 DOI: 10.1038/nrmicro2790] [Citation(s) in RCA: 458] [Impact Index Per Article: 38.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Many species of fungi and oomycetes are plant pathogens of great economic importance. Over the past 7 years, the genomes of more than 30 of these filamentous plant pathogens have been sequenced, revealing remarkable diversity in genome size and architecture. Whereas the genomes of many parasites and bacterial symbionts have been reduced over time, the genomes of several lineages of filamentous plant pathogens have been shaped by repeat-driven expansions. In these lineages, the genes encoding proteins involved in host interactions are frequently polymorphic and reside within repeat-rich regions of the genome. Here, we review the properties of these adaptable genome regions and the mechanisms underlying their plasticity, and we illustrate cases in which genome plasticity has contributed to the emergence of new virulence traits. We also discuss how genome expansions may have had an impact on the co-evolutionary conflict between these filamentous plant pathogens and their hosts.
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Affiliation(s)
- Sylvain Raffaele
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK
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98
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Sequence and analysis of the genome of the pathogenic yeast Candida orthopsilosis. PLoS One 2012; 7:e35750. [PMID: 22563396 PMCID: PMC3338533 DOI: 10.1371/journal.pone.0035750] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 03/24/2012] [Indexed: 01/09/2023] Open
Abstract
Candida orthopsilosis is closely related to the fungal pathogen Candida parapsilosis. However, whereas C. parapsilosis is a major cause of disease in immunosuppressed individuals and in premature neonates, C. orthopsilosis is more rarely associated with infection. We sequenced the C. orthopsilosis genome to facilitate the identification of genes associated with virulence. Here, we report the de novo assembly and annotation of the genome of a Type 2 isolate of C. orthopsilosis. The sequence was obtained by combining data from next generation sequencing (454 Life Sciences and Illumina) with paired-end Sanger reads from a fosmid library. The final assembly contains 12.6 Mb on 8 chromosomes. The genome was annotated using an automated pipeline based on comparative analysis of genomes of Candida species, together with manual identification of introns. We identified 5700 protein-coding genes in C. orthopsilosis, of which 5570 have an ortholog in C. parapsilosis. The time of divergence between C. orthopsilosis and C. parapsilosis is estimated to be twice as great as that between Candida albicans and Candida dubliniensis. There has been an expansion of the Hyr/Iff family of cell wall genes and the JEN family of monocarboxylic transporters in C. parapsilosis relative to C. orthopsilosis. We identified one gene from a Maltose/Galactoside O-acetyltransferase family that originated by horizontal gene transfer from a bacterium to the common ancestor of C. orthopsilosis and C. parapsilosis. We report that TFB3, a component of the general transcription factor TFIIH, undergoes alternative splicing by intron retention in multiple Candida species. We also show that an intein in the vacuolar ATPase gene VMA1 is present in C. orthopsilosis but not C. parapsilosis, and has a patchy distribution in Candida species. Our results suggest that the difference in virulence between C. parapsilosis and C. orthopsilosis may be associated with expansion of gene families.
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99
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Ishikawa FH, Souza EA, Shoji JY, Connolly L, Freitag M, Read ND, Roca MG. Heterokaryon incompatibility is suppressed following conidial anastomosis tube fusion in a fungal plant pathogen. PLoS One 2012; 7:e31175. [PMID: 22319613 PMCID: PMC3271119 DOI: 10.1371/journal.pone.0031175] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 01/03/2012] [Indexed: 01/25/2023] Open
Abstract
It has been hypothesized that horizontal gene/chromosome transfer and parasexual recombination following hyphal fusion between different strains may contribute to the emergence of wide genetic variability in plant pathogenic and other fungi. However, the significance of vegetative (heterokaryon) incompatibility responses, which commonly result in cell death, in preventing these processes is not known. In this study, we have assessed this issue following different types of hyphal fusion during colony initiation and in the mature colony. We used vegetatively compatible and incompatible strains of the common bean pathogen Colletotrichum lindemuthianum in which nuclei were labelled with either a green or red fluorescent protein in order to microscopically monitor the fates of nuclei and heterokaryotic cells following hyphal fusion. As opposed to fusion of hyphae in mature colonies that resulted in cell death within 3 h, fusions by conidial anastomosis tubes (CAT) between two incompatible strains during colony initiation did not induce the vegetative incompatibility response. Instead, fused conidia and germlings survived and formed heterokaryotic colonies that in turn produced uninucleate conidia that germinated to form colonies with phenotypic features different to those of either parental strain. Our results demonstrate that the vegetative incompatibility response is suppressed during colony initiation in C. lindemuthianum. Thus, CAT fusion may allow asexual fungi to increase their genetic diversity, and to acquire new pathogenic traits.
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Affiliation(s)
- Francine H. Ishikawa
- Departamento de Biologia, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Elaine A. Souza
- Departamento de Biologia, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
- * E-mail:
| | - Jun-ya Shoji
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Lanelle Connolly
- Department of Biochemistry and Biophysics, Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
| | - Michael Freitag
- Department of Biochemistry and Biophysics, Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
| | - Nick D. Read
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - M. Gabriela Roca
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
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100
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Zhu B, Zhou Q, Xie G, Zhang G, Zhang X, Wang Y, Sun G, Li B, Jin G. Interkingdom gene transfer may contribute to the evolution of phytopathogenicity in botrytis cinerea. Evol Bioinform Online 2012; 8:105-17. [PMID: 22346340 PMCID: PMC3273930 DOI: 10.4137/ebo.s8486] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The ascomycete Botrytis cinerea is a phytopathogenic fungus infecting and causing significant yield losses in a number of crops. The genome of B. cinerea has been fully sequenced while the importance of horizontal gene transfer (HGT) to extend the host range in plant pathogenic fungi has been recently appreciated. However, recent data confirm that the B. cinerea fungus shares conserved virulence factors with other fungal plant pathogens with narrow host range. Therefore, interkingdom HGT may contribute to the evolution of phytopathogenicity in B. cinerea. In this study, a stringent genome comparison pipeline was used to identify potential genes that have been obtained by B. cinerea but not by other fungi through interkingdom HGT. This search led to the identification of four genes: a UDP-glucosyltransferase (UGT), a lipoprotein and two alpha/beta hydrolase fold proteins. Phylogenetic analysis of the four genes suggests that B. cinerea acquired UGT from plants and the other 3 genes from bacteria. Based on the known gene functions and literature searching, a correlation between gene acquision and the evolution of pathogenicity in B. cinerea can be postulated.
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Affiliation(s)
- Bo Zhu
- State Key Laboratory of Rice Biology and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Biotechnology, Zhejiang University, Hangzhou 310029, China
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