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Kokkoris V, Stefani F, Dalpé Y, Dettman J, Corradi N. Nuclear Dynamics in the Arbuscular Mycorrhizal Fungi. TRENDS IN PLANT SCIENCE 2020; 25:765-778. [PMID: 32534868 DOI: 10.1016/j.tplants.2020.05.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 04/30/2020] [Accepted: 05/20/2020] [Indexed: 05/09/2023]
Abstract
Arbuscular mycorrhizal fungi (AMF) are plant root symbionts that continuously carry thousands of nuclei in their spores and hyphae. This unique cellular biology raises fundamental questions regarding their nuclear dynamics. This review aims to address these by synthesizing current knowledge of nuclear content and behavior in these ubiquitous soil fungi. Overall, we find that that nuclear counts, as well as the nuclei shape and organization, vary drastically both within and among species in this group. By comparing these features with those of other fungi, we highlight unique aspects of the AMF nuclear biology that require further attention. The potential implications of the observed nuclear variability for the biology and evolution of these widespread plant symbionts are discussed.
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Affiliation(s)
- Vasilis Kokkoris
- Department of Biology, University of Ottawa, ON, Ottawa, K1N 6N5, Canada; Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, ON, Ottawa, K1A 0C5, Canada.
| | - Franck Stefani
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, ON, Ottawa, K1A 0C5, Canada
| | - Yolande Dalpé
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, ON, Ottawa, K1A 0C5, Canada
| | - Jeremy Dettman
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, ON, Ottawa, K1A 0C5, Canada
| | - Nicolas Corradi
- Department of Biology, University of Ottawa, ON, Ottawa, K1N 6N5, Canada.
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Corradi N, Brachmann A. Fungal Mating in the Most Widespread Plant Symbionts? TRENDS IN PLANT SCIENCE 2017; 22:175-183. [PMID: 27876487 DOI: 10.1016/j.tplants.2016.10.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/26/2016] [Accepted: 10/28/2016] [Indexed: 06/06/2023]
Abstract
Arbuscular mycorrhizal fungi (AMF) are relevant plant symbionts whose hyphae and spores carry hundreds of coexisting nuclei with supposedly divergent genomes but no sign of sexual reproduction. This unusual biology suggested that conventional fungal mating is not amendable to optimize strains for plant growth, but recent evidence of sexual-related nuclear inheritance in these organisms is now challenging this widespread notion. Here, we outline our knowledge of AMF genetics within a historical context, and discuss how past and new information in this area changed our understanding of AMF biology. We also highlight the mating-related processes in AMF, and propose new research avenues and approaches that could lead to a better application of these organisms for agricultural and environmental practices.
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Affiliation(s)
- Nicolas Corradi
- Canadian Institute for Advanced Research, Department of Biology, University of Ottawa, Ottawa, ON, Canada.
| | - Andreas Brachmann
- LMU Munich, Faculty of Biology, Genetics, D-82152 Planegg-Martinsried, Germany
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Tavares S, Ramos AP, Pires AS, Azinheira HG, Caldeirinha P, Link T, Abranches R, Silva MDC, Voegele RT, Loureiro J, Talhinhas P. Genome size analyses of Pucciniales reveal the largest fungal genomes. FRONTIERS IN PLANT SCIENCE 2014; 5:422. [PMID: 25206357 PMCID: PMC4143883 DOI: 10.3389/fpls.2014.00422] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 08/07/2014] [Indexed: 05/09/2023]
Abstract
Rust fungi (Basidiomycota, Pucciniales) are biotrophic plant pathogens which exhibit diverse complexities in their life cycles and host ranges. The completion of genome sequencing of a few rust fungi has revealed the occurrence of large genomes. Sequencing efforts for other rust fungi have been hampered by uncertainty concerning their genome sizes. Flow cytometry was recently applied to estimate the genome size of a few rust fungi, and confirmed the occurrence of large genomes in this order (averaging 225.3 Mbp, while the average for Basidiomycota was 49.9 Mbp and was 37.7 Mbp for all fungi). In this work, we have used an innovative and simple approach to simultaneously isolate nuclei from the rust and its host plant in order to estimate the genome size of 30 rust species by flow cytometry. Genome sizes varied over 10-fold, from 70 to 893 Mbp, with an average genome size value of 380.2 Mbp. Compared to the genome sizes of over 1800 fungi, Gymnosporangium confusum possesses the largest fungal genome ever reported (893.2 Mbp). Moreover, even the smallest rust genome determined in this study is larger than the vast majority of fungal genomes (94%). The average genome size of the Pucciniales is now of 305.5 Mbp, while the average Basidiomycota genome size has shifted to 70.4 Mbp and the average for all fungi reached 44.2 Mbp. Despite the fact that no correlation could be drawn between the genome sizes, the phylogenomics or the life cycle of rust fungi, it is interesting to note that rusts with Fabaceae hosts present genomes clearly larger than those with Poaceae hosts. Although this study comprises only a small fraction of the more than 7000 rust species described, it seems already evident that the Pucciniales represent a group where genome size expansion could be a common characteristic. This is in sharp contrast to sister taxa, placing this order in a relevant position in fungal genomics research.
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Affiliation(s)
- Sílvia Tavares
- Centro de Investigação das Ferrugens do Cafeeiro, BioTrop, Instituto de Investigação Científica TropicalOeiras, Portugal
- Plant Cell Biology Laboratory, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de LisboaOeiras, Portugal
| | - Ana Paula Ramos
- CEER-Biosystems Engeneering, Instituto Superior de Agronomia, Universidade de LisboaLisbon, Portugal
| | - Ana Sofia Pires
- Centro de Investigação das Ferrugens do Cafeeiro, BioTrop, Instituto de Investigação Científica TropicalOeiras, Portugal
- Plant Cell Biology Laboratory, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de LisboaOeiras, Portugal
| | - Helena G. Azinheira
- Centro de Investigação das Ferrugens do Cafeeiro, BioTrop, Instituto de Investigação Científica TropicalOeiras, Portugal
- CEER-Biosystems Engeneering, Instituto Superior de Agronomia, Universidade de LisboaLisbon, Portugal
| | - Patrícia Caldeirinha
- Department of Life Sciences, Centre for Functional Ecology, University of CoimbraCoimbra, Portugal
| | - Tobias Link
- Institut für Phytomedizin, Universität HohenheimStuttgart, Germany
| | - Rita Abranches
- Plant Cell Biology Laboratory, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de LisboaOeiras, Portugal
| | - Maria do Céu Silva
- Centro de Investigação das Ferrugens do Cafeeiro, BioTrop, Instituto de Investigação Científica TropicalOeiras, Portugal
- CEER-Biosystems Engeneering, Instituto Superior de Agronomia, Universidade de LisboaLisbon, Portugal
| | - Ralf T. Voegele
- Institut für Phytomedizin, Universität HohenheimStuttgart, Germany
| | - João Loureiro
- Department of Life Sciences, Centre for Functional Ecology, University of CoimbraCoimbra, Portugal
| | - Pedro Talhinhas
- Centro de Investigação das Ferrugens do Cafeeiro, BioTrop, Instituto de Investigação Científica TropicalOeiras, Portugal
- Plant Cell Biology Laboratory, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de LisboaOeiras, Portugal
- CEER-Biosystems Engeneering, Instituto Superior de Agronomia, Universidade de LisboaLisbon, Portugal
- *Correspondence: Pedro Talhinhas, Centro de Investigação das Ferrugens do Cafeeiro, BioTrop, Instituto de Investigação Científica Tropical, Quinta do Marquês, 2784-505 Oeiras, Portugal e-mail:
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Zeze A, Sulistyowati E, Ophel-Keller K, Barker S, Smith S. Intersporal Genetic Variation of Gigaspora margarita, a Vesicular Arbuscular Mycorrhizal Fungus, Revealed by M13 Minisatellite-Primed PCR. Appl Environ Microbiol 2010; 63:676-8. [PMID: 16535520 PMCID: PMC1389526 DOI: 10.1128/aem.63.2.676-678.1997] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spores of vesicular arbuscular mycorrhizal (VAM) fungi contain thousands of nuclei. In order to understand the karyotic structure of a VAM fungus spore, the genetic variation of the first generation of spores from a VAM fungus (Gigaspora margarita) was examined. Spores originating from both single- and multispore inoculations of the species G. margarita were analyzed by M13 minisatellite-primed PCR. In both cases, different fingerprints were obtained from individual spores with few spores exhibiting similar fingerprints. These results can be explained only by a heterokaryotic status of the nuclear population within a spore.
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Stummer BE, Zanker T, Harvey PR, Scott ES. Detection and quantification of Erysiphe necator DNA in wine grapes and resultant must and juice. MYCOLOGICAL RESEARCH 2006; 110:1184-92. [PMID: 17010594 DOI: 10.1016/j.mycres.2006.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2005] [Revised: 05/31/2006] [Accepted: 07/07/2006] [Indexed: 05/12/2023]
Abstract
Powdery mildew of grapevines is difficult to assess visually at the weighbridge, particularly in large consignments of machine-harvested fruit. To facilitate accurate methods for the detection and quantification of the disease in grape samples obtained from both the vineyard and winery, we developed a DNA probe for the pathogen Erysiphe necator. The E. necator-specific 450 bp DNA fragment pEnA1, targets highly repetitive sequences and was isolated from a partial genomic library. In screening for species specificity, clone pEnA1 was used in slot-blot hybridization and detected E. necator DNA from grapes and resultant must and juice, but not from clarified juice and wine. The detection threshold was approximately 50 pg of E. necator DNA per 100 ng total DNA of grape sample and was equivalent to 1-5% of a grape bunch visually affected by powdery mildew. Disease severity, expressed as the percentage of surface area of a bunch with powdery mildew, and E. necator DNA content were highly correlated, r2=0.955, P<0.001. The DNA-based hybridization assay has the potential to predict the severity of powdery mildew in grape samples from the vineyard and in must and juice samples at the winery. The DNA sequence of clone pEnA1 was used to design species-specific primers, the results maintaining the same specificity patterns observed in the initial hybridization assays. The PCR-based assay was sensitive enough to detect approximately 1 pg DNA, being equivalent to 1 conidium per sample. This is the first report to date of the detection of all known phenetic groups of E. necator DNA and of the quantification of DNA from grape samples at the winery. Accurate information on the extent of powdery mildew contamination of grape lots would enable wineries to make more informed decisions about the use of fruit and must.
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Affiliation(s)
- Belinda E Stummer
- Cooperative Research Centre for Viticulture, Glen Osmond, 5064, South Australia.
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Neppelenbroek KH, Campanha NH, Spolidorio DMP, Spolidorio LC, Seó RS, Pavarina AC. Molecular fingerprinting methods for the discrimination between C. albicans and C. dubliniensis. Oral Dis 2006; 12:242-53. [PMID: 16700733 DOI: 10.1111/j.1601-0825.2005.01189.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Opportunistic fungal pathogens are becoming increasingly important causes of both community-acquired and nosocomial infections. The most important fungal pathogens are yeast species belonging to the genus Candida. These species show differences in levels of resistance to antifungal agents and mortality. Consequently, it is important to correctly identify the causative organism to the species level. Identification of Candida dubliniensis in particular remains problematic because of the high degree of phenotypic similarity between this species and Candida albicans. However, as the differences between both are most pronounced at the genetic level, several studies have been conducted in order to provide a specific and rapid identification fingerprinting molecular test. In most candidal infectious, no single DNA fingerprinting technique has evolved as a dominant method, and each method has its advantages, disadvantages and limitations. Moreover, the current challenge of these techniques is to compile standardized patterns in a database for interlaboratory use and future reference. This review provides an overview of most common molecular fingerprinting techniques currently available for discrimination of C. albicans and C. dubliniensis.
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Affiliation(s)
- K H Neppelenbroek
- Department of Dental Materials and Prosthodontics, Araraquara Dental School, São Paulo State University, São Paulo, Brazil
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Bergero R. AT-rich sequences from the arbuscular mycorrhizal fungus Gigaspora rosea exhibit ARS function in the yeast Saccharomyces cerevisiae. Fungal Genet Biol 2006; 43:337-42. [PMID: 16504551 DOI: 10.1016/j.fgb.2006.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2005] [Revised: 12/24/2005] [Accepted: 01/09/2006] [Indexed: 11/22/2022]
Abstract
Autonomous replicating sequences are DNA elements that trigger DNA replication and are widely used in the development of episomal transformation vectors for fungi. In this paper, a genomic library from the mycorrhizal fungus Gigaspora rosea was constructed in the integrative plasmid YIp5 and screened in the budding yeast Saccharomyces cerevisiae for sequences that act as ARS and trigger plasmid replication. Two genetic elements (GrARS2, GrARS6) promoted high-rates of yeast transformation. Sequence analysis of these elements shows them to be AT-rich (72-80%) and to contain multiple near-matches to the yeast autonomous consensus sequences ACS and EACS. GrARS2 contained a putative miniature inverted-repeat transposable element (MITE) delimited by 28-bp terminal inverted repeats (TIRs). Disruption of this element and removal of one TIR increased plasmid stability several fold. The potential for palindromes to affect DNA replication is discussed.
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Affiliation(s)
- Roberta Bergero
- Crop and Soil Research Group, Scottish Agricultural College, King's Buildings, West Mains Road, Edinburgh EH9 3JG, UK.
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8
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Isayenkov S, Fester T, Hause B. Rapid determination of fungal colonization and arbuscule formation in roots of Medicago truncatula using real-time (RT) PCR. JOURNAL OF PLANT PHYSIOLOGY 2004; 161:1379-1383. [PMID: 15658808 DOI: 10.1016/j.jplph.2004.04.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The quantifications of root colonization and symbiotic activity in the arbuscular mycorrhizal (AM) association of Medicago truncatula and Glomus intraradices were performed by quantitative polymerase chain reaction (real-time PCR). A strong correlation between fungal colonization of the root system and the amounts of fungal rDNA and rRNA were shown. In contrast, the transcript levels of the AM-specific phosphate transporter 4 from M. truncatula (MtPT4) correlate with arbuscule formation rather than with fungal colonization. These results suggest (i) that real-time PCR assay is a rapid, useful, and accurate method for the determination of arbuscular mycorrhizal features, (ii) that the amount of fungal rDNA or rRNA is a good parameter to estimate fungal colonization, and (iii) that it is necessary to evaluate the amount of other transcripts-like the MtPT4 transcript-to obtain additional information about the symbiotic state of the colonized root system.
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Affiliation(s)
- Stanislav Isayenkov
- Institute of Plant Biochemistry, Department of Secondary Metabolism, Weinberg 3, 06120 Halle (Saale), Germany.
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9
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Kirk JL, Beaudette LA, Hart M, Moutoglis P, Klironomos JN, Lee H, Trevors JT. Methods of studying soil microbial diversity. J Microbiol Methods 2004; 58:169-88. [PMID: 15234515 DOI: 10.1016/j.mimet.2004.04.006] [Citation(s) in RCA: 552] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Accepted: 04/07/2004] [Indexed: 11/25/2022]
Abstract
Soil microorganisms, such as bacteria and fungi, play central roles in soil fertility and promoting plant health. This review examines and compares the various methods used to study microbial diversity in soil.
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Affiliation(s)
- Jennifer L Kirk
- Department of Environmental Biology, University of Guelph, Ontario Agricultural College, Guelph, Ontario, Canada
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10
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Ferrol N, Azcón-Aguilar C, Bago B, Franken P, Gollotte A, González-Guerrero M, Harrier LA, Lanfranco L, van Tuinen D, Gianinazzi-Pearson V. Genomics of Arbuscular Mycorrhizal Fungi. FUNGAL GENOMICS 2004. [DOI: 10.1016/s1874-5334(04)80019-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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11
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Genetic Studies of the Structure and Diversity of Arbuscular Mycorrhizal Fungal Communities. ACTA ACUST UNITED AC 2003. [DOI: 10.1007/978-3-540-38364-2_8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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Yokoyama K, Tateishi T, Marumoto T, Saito M. A molecular marker diagnostic of a specific isolate of an arbuscular mycorrhizal fungus, Gigaspora margarita. FEMS Microbiol Lett 2002; 212:171-5. [PMID: 12113930 DOI: 10.1111/j.1574-6968.2002.tb11262.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
To investigate the auto-ecology of a strain of Gigaspora margarita in a commercial inoculum, we found a pair of PCR primers amplifying a sequence of 235 bp diagnostic of the isolate. We designed an oligonucleotide probe based on the DNA sequence. The combination of PCR and the probing successfully detected the diagnostic sequence from both DNA preparations of single spores and colonized roots. This protocol enabled us to distinguish the isolate among several isolates from Japan, Nepal and the USA.
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Affiliation(s)
- Kazuhira Yokoyama
- Department of Biological Science, Faculty of Agriculture, Yamaguchi University, 1677-1, Yoshida, Japan.
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13
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Giovannetti M, Avio L. Biotechnology of arbuscular mycorrhizas. AGRICULTURE AND FOOD PRODUCTION 2002. [DOI: 10.1016/s1874-5334(02)80014-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Kjøller R, Rosendahl S. Molecular diversity of glomalean (arbuscular mycorrhizal) fungi determined as distinct Glomus specific DNA sequences from roots of field grown peas fungi. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0953-7562(08)61964-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Vandenkoornhuyse P, Leyval C, Bonnin I. High genetic diversity in arbuscular mycorrhizal fungi: evidence for recombination events. Heredity (Edinb) 2001; 87:243-53. [PMID: 11703516 DOI: 10.1046/j.1365-2540.2001.00941.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The genetic diversity of spores of two indigenous species of Glomus isolated from three soils of a long-term field experiment amended by different quantities of sewage sludges has been evaluated. Three populations of spores of Glomus claroideum (W2537) and three populations of spores of Glomus DAOM 225952 (W2538) were analysed using a microsatellite primer and aliquots of genomic DNA were obtained from single spores (Inter Simple Sequence Repeat (ISSR) fingerprints). 39 polymorphic bands were found for G. claroideum, and 43 in Glomus DAOM 225952. The intraspecific diversity was high, ranging from 22 to 33 different electrophoretic types for G. claroideum, and 15-27 for Glomus DAOM 225952 depending on the population. Resampling experiments showed that the number of polymorphic bands was sufficient to score all multilocus profiles in the populations and to describe the clonality structure within populations. On average, one multilocus profile was represented by about four spores whatever the population and the species. Partitioning of the within-species phenotypic variance showed that more than 92% of the variation was found within populations, while the among-population variance component accounted for less than 8%, even though it was statistically different from 0. This result is confirmed by the fact that only few multilocus profiles were shared by two populations of G. claroideum, and none by populations of Glomus DAOM 225952. In addition to the high level of diversity observed within populations, linkage disequilibria analyses and association indices calculated across loci indicates that reproduction cannot be solely clonal. Recombination or recombination-like events are likely to occur in these arbuscular mycorrhizal fungi. An 'epidemic' population structure was found for both fungal species in the soil that had received high amounts of sewage sludge.
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Affiliation(s)
- P Vandenkoornhuyse
- Centre de Pédologie Biologique, CNRS UPR 6831, 17 rue Notre-Dame des Pauvres, BP5, F-54501 Vandoeuvre les Nancy cedex, France.
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Boehm EW, Ma Z, Michailides TJ. Species-Specific Detection of Monilinia fructicola from California Stone Fruits and Flowers. PHYTOPATHOLOGY 2001; 91:428-439. [PMID: 18943587 DOI: 10.1094/phyto.2001.91.5.428] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
ABSTRACT A set of molecular diagnostics was developed for Monilinia fructicola, causal agent of brown rot of stone fruits, capable of sensitive detection of the pathogen in planta. Species-specific repetitive sequences were identified from a partial library of 312 recombinant clones hybridized with total DNA, followed by subsequent screening for specificity. One hundred isolates, comprising 12 fungal species common to California stone fruits, were surveyed for specificity. Three clones hybridized to 60 geographically diverse M. fructicola isolates (California, Michigan, Georgia, Oregon, and Australia) to the exclusion of all other fungi surveyed, including the closely related M. laxa (n = 12). Two clones were identical and of extrachromosomal origin (pMF73 and pMF150), whereas the third (pMF210) migrated with uncut DNA. The sensitivity of all three was comparable and capable of detecting 50 pg of fungal DNA in dot blot hybridizations. Six species-specific primer pair sets were designed. They maintained the same specificity patterns observed in the initial hybridization surveys and were sensitive enough to detect 50 fg of fungal DNA template, approximately equivalent to 10 spores. The species-specific clones were capable of detecting the pathogen in planta, specifically from infected plum flowers and nectarine fruit tissue, using both hybridization- and polymerase chain reaction-based methodologies.
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Harrier LA, Millam S. Biolistic transformation of arbuscular mycorrhizal fungi. Progress and perspectives. Mol Biotechnol 2001; 18:25-33. [PMID: 11439697 DOI: 10.1385/mb:18:1:25] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Gene transfer systems have proved effective for the transformation of a range of organisms for both fundamental and applied studies. Biolistic transformation is a powerful method for the gene transfer into various organisms and tissues that have proved recalcitrant to more conventional means. For fungi, the biolistic approach is particularly effective where protoplasts are difficult to obtain and/or the organisms are difficult to culture. This is particularly applicable to arbuscular mycorrhizal (AM) fungi, being as they are obligate symbionts that can only be propagated in association with intact plants or root explants. Furthermore, these fungi are aseptate and protoplasts cannot be released. Recent advancements in gene transformation systems have enabled the use of biolistic technology to introduce foreign DNA linked to molecular markers into these fungi. In this review we discuss the development of transformation strategies for AM fungi by biolistics and highlight the areas of this technology which require further development for the stable transformation of these elusive organisms.
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Affiliation(s)
- L A Harrier
- Plant and Crop Science Division, Scottish Agricultural College, West Mains Road, Edinburgh, West Lothian, Scotland, UK.
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Harrier LA. The arbuscular mycorrhizal symbiosis: a molecular review of the fungal dimension. JOURNAL OF EXPERIMENTAL BOTANY 2001; 52:469-478. [PMID: 11326053 DOI: 10.1093/jexbot/52.suppl_1.469] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Mycorrhizal associations vary widely in structure and function, but the most common interaction is the arbuscular mycorrhizal (AM) symbiosis. This interaction is formed between the roots of over 80% of all terrestrial plant species and Zygomycete fungi from the Order Glomales. These fungi are termed AM fungi and are obligate symbionts which form endomycorrhizal symbioses. This symbiosis confers benefits directly to the host plant's growth and development through the acquisition of P and other mineral nutrients from the soil by the fungus. In addition, they may also enhance the plant's resistance to biotic and abiotic stresses. These beneficial effects of the AM symbiosis occur as a result of a complex molecular dialogue between the two symbiotic partners. Identifying the molecules involved in the dialogue is a prerequisite for a greater understanding of the symbiosis. Ongoing research attempts to understand the underlying dialogue and concomitant molecular changes occurring in the plant and the fungus during the establishment of a functioning AM symbiosis. This paper focuses on the molecular approaches being used to study AM fungal genes being expressed in the symbiotic and asymbiotic stages of its lifecycle. In addition, the importance of studying these fungi, in relation to understanding plant processes, is discussed briefly.
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Affiliation(s)
- L A Harrier
- Biotechnology Department, Plant Science Division, Scottish Agricultural College, Kings Buildings, Mains Road, Edinburgh, Scotland, UK.
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Paolocci F, Rubini A, Riccioni C, Granetti B, Arcioni S. Cloning and characterization of two repeated sequences in the symbiotic fungus Tuber melanosporum Vitt. FEMS Microbiol Ecol 2000; 34:139-146. [PMID: 11102691 DOI: 10.1111/j.1574-6941.2000.tb00763.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Two repeated DNA sequences of European strains of the symbiotic fungus Tuber melanosporum were isolated and characterized. One of these, SS14, representing about 0.05% of the fungal genome, was shown to be a T. melanosporum-specific sequence by Southern and dot-blot hybridization. The second one, named SS15, is about 0.0025% of the entire genome, and it is specific not only to T. melanosporum but also to the Asian black truffle Tuber indicum. Neither of these two fragments hybridizes with any of the other European truffle species tested. By sequence analysis of these two fragments, PCR primers were designed and used to selectively amplify DNA from T. melanosporum ascocarps and ectomycorrhizae by simple and multiplex PCR. No amplification products were obtained with DNA from either mycorrhizal roots or fruit bodies of other ectosymbiotic fungi. The two identified genomic traits also provided useful information for a better understanding of the phylogenetic relationships among black truffle species and for testing T. melanosporum intraspecific variability.
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Abstract
Arbuscular mycorrhizae are symbiotic associations formed between a wide range of plant species including angiosperms, gymnosperms, pteridophytes, and some bryophytes, and a limited range of fungi belonging to a single order, the Glomales. The symbiosis develops in the plant roots where the fungus colonizes the apoplast and cells of the cortex to access carbon supplied by the plant. The fungal contribution to the symbiosis is complex, but a major aspect includes the transfer of mineral nutrients, particularly phosphate from the soil to the plant. Development of this highly compatible association requires the coordinate molecular and cellular differentiation of both symbionts to form specialized interfaces over which bi-directional nutrient transfer occurs. Recent insights into the molecular events underlying these aspects of the symbiosis are discussed.
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Affiliation(s)
- Maria J. Harrison
- The Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73402; e-mail:
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Hosny M, Hijri M, Passerieux E, Dulieu H. rDNA units are highly polymorphic in Scutellospora castanea (glomales, zygomycetes). Gene 1999; 226:61-71. [PMID: 9889322 DOI: 10.1016/s0378-1119(98)00562-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ribosomal DNA (rDNA) units in the glomalean zygomycete fungus Scutellospora castanea were analyzed. Dot-blot assays allowed an estimation of 75 copies per genome. After constructing a genomic library in a phage lambdaEMBL3 vector, 13 rDNA clones were screened and explored. PCR experiments confirmed their nature and allowed homologous probes to be obtained. Restriction-fragment length polymorphism (RFLP) analysis and hybridizations with 18 s and 25 s probes allowed their grouping into nine families. The 18 s gene from these 13 clones was partially sequenced. The resulting 550 bases sequences were analyzed, and a phylogenetic tree was inferred. This revealed that two clones contain one highly divergent rDNA family (rUSc1) by comparison with other known 18 s sequences from the database. A phylogenetic tree was constructed with the entire 18 s sequences of rUSc1, rUSc3 and those of seven species representative of the glomalean fungi, Glomus, Entrophospora, Acaulospora, Scutellospora and Gigaspora. This tree confirmed that the rUSc1 sequence is the neighbor of 18 s sequences from Glomus (Glomineae), while rUSc3 remained in the group of the Gigaspora and Scutellospora (Gigasporineae). A specific primer, rUSc1-1, was generated from the ITS region of rUSc1, and used for PCR amplification from single spores, depicting the presence of rUSc1 in the genome of S. castanea at a lower frequency than other units.
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Affiliation(s)
- M Hosny
- Laboratoire de Phytoparasitologie, INRA/CNRS, CMSE-INRA, BV 1540, 21034, Dijon, France
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The protein pattern of spores of arbuscular mycorrhizal fungi: comparison of species, isolates and physiological stages. ACTA ACUST UNITED AC 1998. [DOI: 10.1017/s095375629700587x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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van Tuinen D, Jacquot E, Zhao B, Gollotte A, Gianinazzi-Pearson V. Characterization of root colonization profiles by a microcosm community of arbuscular mycorrhizal fungi using 25S rDNA-targeted nested PCR. Mol Ecol 1998; 7:879-87. [PMID: 9691489 DOI: 10.1046/j.1365-294x.1998.00410.x] [Citation(s) in RCA: 316] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The aim of the present work was to study colonization patterns in roots by different arbuscular mycorrhizal fungi developing from a mixed community in soil. As different fungi cannot be distinguished with certainty in planta on the basis of fungal structures, taxon-discriminating molecular probes were developed. The 5' end of the large ribosomal subunit containing the variable domains D1 and D2 was amplified by PCR from Glomus mosseae (BEG12), G. intraradices (LPA8), Gigaspora rosea (BEG9) and Scutellospora castanea (BEG1) using newly designed eukaryote-specific primers. Sequences of the amplification products showed high interspecies variability and PCR taxon-discriminating primers were designed to distinguish between each of these four fungi. A nested PCR, using universal eukaryotic primers for the first amplification and taxon-discriminating primers for the second, was performed on individual trypan blue-stained mycorrhizal root fragments of onion and leek, and root colonization by four fungi inoculated together in a microcosm experiment was estimated. More than one fungus was detected in the majority of root fragments and all four fungi frequently co-existed within the same root fragment. Root colonization by G. mosseae and G. intraradices was similar from individual mixed inoculum, whilst the frequency of S. castanea and Gig. rosea increased in the presence of the two Glomus species, suggesting that synergistic interactions may exist between some arbuscular mycorrhizal fungi.
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Affiliation(s)
- D van Tuinen
- Laboratoire de Phytoparasitologie INRA/CNRS, Centre de Microbiologie du Sol l'Environnement, Dijon, France.
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Quantification of an arbuscular mycorrhizal fungus, Glomus mosseae, within plant roots by competitive polymerase chain reaction. ACTA ACUST UNITED AC 1997. [DOI: 10.1017/s0953756297004218] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Hosny M, Païs de Barros JP, Gianinazzi-Pearson V, Dulieu H. Base composition of DNA from glomalean fungi: high amounts of methylated cytosine. Fungal Genet Biol 1997; 22:103-11. [PMID: 9367657 DOI: 10.1006/fgbi.1997.1008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Glomales (Zygomycetes) are obligate fungal symbionts of roots of land plants and form arbuscular mycorrhiza. Sporal DNA of 10 isolates belonging to nine species was purified and the base composition was determined by RP-HPLC. Base composition fell in a narrow range between 30 and 35% G + C. A high amount of methylated cytosine (mC) accounting for 2-4% of the total nucleotides was found in all taxa. The DNA melting profile was defined for Scutellospora castanea. It corresponded to 32% G + C, and the shape of the denaturation curve suggested a heterogeneity in the GC content within the fungal genome. Knowledge of GC contents and variations between taxa are essential for evaluating nuclear DNA content using fluorimetric methods, and high proportions of mC/C + mC in the genomes of glomalean fungi could reflect the existence of repeated DNA families. Results are discussed in relation to data for other fungi and eukaryotes.
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Affiliation(s)
- M Hosny
- Laboratoire de Phytoparasitologie, INRA/CNRS, CMSE-INRA, Dijon Cédex, 21034, France
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