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Menocal O, Cruz LF, Kendra PE, Crane JH, Cooperband MF, Ploetz RC, Carrillo D. Xyleborus bispinatus Reared on Artificial Media in the Presence or Absence of the Laurel Wilt Pathogen (Raffaelea lauricola). INSECTS 2018; 9:E30. [PMID: 29495585 PMCID: PMC5872295 DOI: 10.3390/insects9010030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 02/12/2018] [Accepted: 02/24/2018] [Indexed: 11/16/2022]
Abstract
Like other members of the tribe Xyleborini, Xyleborus bispinatus Eichhoff can cause economic damage in the Neotropics. X. bispinatus has been found to acquire the laurel wilt pathogen Raffaelea lauricola (T. C. Harr., Fraedrich & Aghayeva) when breeding in a host affected by the pathogen. Its role as a potential vector of R. lauricola is under investigation. The main objective of this study was to evaluate three artificial media, containing sawdust of avocado (Persea americana Mill.) and silkbay (Persea humilis Nash.), for rearing X. bispinatus under laboratory conditions. In addition, the media were inoculated with R. lauricola to evaluate its effect on the biology of X. bispinatus. There was a significant interaction between sawdust species and R. lauricola for all media. Two of the media supported the prolific reproduction of X. bispinatus, but the avocado-based medium was generally more effective than the silkbay-based medium, regardless whether or not it was inoculated with R. lauricola. R. lauricola had a neutral or positive effect on beetle reproduction. The pathogen was frequently recovered from beetle galleries, but only from a few individuals which were reared on inoculated media, and showed limited colonization of the beetle's mycangia. Two media with lower water content were most effective for rearing X. bispinatus.
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Affiliation(s)
- Octavio Menocal
- Tropical Research & Education Center, University of Florida 18905 SW 280th St, Homestead, FL 33031, USA.
| | - Luisa F Cruz
- Tropical Research & Education Center, University of Florida 18905 SW 280th St, Homestead, FL 33031, USA.
| | - Paul E Kendra
- Subtropical Horticulture Research Station, USDA-ARS, 13601 Old Cutler Rd., Miami, FL 33158, USA.
| | - Jonathan H Crane
- Tropical Research & Education Center, University of Florida 18905 SW 280th St, Homestead, FL 33031, USA.
| | - Miriam F Cooperband
- Otis Laboratory, USDA-APHIS-PPQ-CPHST, 1398 W. Truck Road, Buzzards Bay, MA 02542, USA.
| | - Randy C Ploetz
- Tropical Research & Education Center, University of Florida 18905 SW 280th St, Homestead, FL 33031, USA.
| | - Daniel Carrillo
- Tropical Research & Education Center, University of Florida 18905 SW 280th St, Homestead, FL 33031, USA.
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Pouzoulet J, Scudiero E, Schiavon M, Rolshausen PE. Xylem Vessel Diameter Affects the Compartmentalization of the Vascular Pathogen Phaeomoniella chlamydospora in Grapevine. FRONTIERS IN PLANT SCIENCE 2017; 8:1442. [PMID: 28871268 PMCID: PMC5566965 DOI: 10.3389/fpls.2017.01442] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/03/2017] [Indexed: 05/23/2023]
Abstract
Fungal wilt diseases are a threat to global food safety. Previous studies in perennial crops showed that xylem vessel diameter affects disease susceptibility. We tested the hypothesis that xylem vessel diameter impacts occlusion processes and pathogen compartmentalization in Vitis vinifera L. We studied the interaction between four grape commercial cultivars with the vascular wilt pathogen Phaeomoniella chlamydospora. We used qPCR and wood necrotic lesion length to measure fungal colonization coupled with histological studies to assess differences in xylem morphology, pathogen compartmentalization, and fungal colonization strategy. We provided evidence that grape cultivar with wide xylem vessel diameter showed increased susceptibility to P. chlamydospora. The host response to pathogen included vessel occlusion with tyloses and gels, deposition of non-structural phenolic compounds and suberin in vessel walls and depletion of starch in parenchyma cells. Pathogen compartmentalization was less efficient in wide xylem vessels than in narrow diameter vessels. Large vessels displayed higher number of tyloses and gel pockets, which provided substrate for P. chlamydospora growth and routes to escape occluded vessels. We discuss in which capacity xylem vessel diameter is a key determinant of the compartmentalization process and in turn grape cultivar resistance to disease caused by P. chlamydospora.
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Affiliation(s)
- Jérôme Pouzoulet
- Department of Botany and Plant Sciences, University of California, Riverside, RiversideCA, United States
| | - Elia Scudiero
- United States Salinity Laboratory, United States Department of Agriculture–Agricultural Research Service, RiversideCA, United States
| | - Marco Schiavon
- Department of Botany and Plant Sciences, University of California, Riverside, RiversideCA, United States
| | - Philippe E. Rolshausen
- Department of Botany and Plant Sciences, University of California, Riverside, RiversideCA, United States
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53
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Sherif SM, Erland LA, Shukla MR, Saxena PK. Bark and wood tissues of American elm exhibit distinct responses to Dutch elm disease. Sci Rep 2017; 7:7114. [PMID: 28769110 PMCID: PMC5540924 DOI: 10.1038/s41598-017-07779-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 07/04/2017] [Indexed: 01/08/2023] Open
Abstract
Tolerance to Dutch elm disease (DED) has been linked to the rapid and/or high induction of disease-responsive genes after infection with the fungus Ophiostoma novo-ulmi. Although the fungal infection by O. novo-ulmi primarily takes places in xylem vessels, it is still unclear how xylem contributes to the defense against DED. Taking advantage of the easy separation of wood and bark tissues in young American elm saplings, here we show that most disease-responsive genes exhibited higher expression in wood compared to bark tissues after fungal infection. On the other hand, the stress-related phytohormones were generally more abundant in the bark compared to wood tissues. However, only endogenous levels of jasmonates (JAs), but not salicylic acid (SA) and abscisic acid (ABA) increased in the inoculated tissues. This, along with the upregulation of JA-biosynthesis genes in inoculated bark and core tissues further suggest that phloem and xylem might contribute to the de novo biosynthesis of JA after fungal infection. The comparison between two tolerant elm varieties, 'Valley Forge' and 'Princeton,' also indicated that tolerance against DED might be mediated by different mechanisms in the xylem. The present study sheds some light on the amplitude and kinetics of defense responses produced in the xylem and phloem in response to DED.
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Affiliation(s)
- S M Sherif
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada
- Virginia Tech, Alson H. Smith, Jr. Agricultural Research and Extension Center, Winchester, VA, USA
| | - L A Erland
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada
| | - M R Shukla
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada
| | - P K Saxena
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada.
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Abstract
While fungi can make positive contributions to ecosystems and agro-ecosystems, for example, in mycorrhizal associations, they can also have devastating impacts as pathogens of plants and animals. In undisturbed ecosystems, most such negative interactions will be limited through the coevolution of fungi with their hosts. In this article, we explore what happens when pathogenic fungi spread beyond their natural ecological range and become invasive on naïve hosts in new ecosystems. We will see that such invasive pathogens have been problematic to humans and their domesticated plant and animal species throughout history, and we will discuss some of the most pressing fungal threats of today.
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Abstract
Emerging pathogens of crops threaten food security and are increasingly problematic due to intensive agriculture and high volumes of trade and transport in plants and plant products. The ability to predict pathogen risk to agricultural regions would therefore be valuable. However, predictions are complicated by multi-faceted relationships between crops, their pathogens, and climate change. Climate change is related to industrialization, which has brought not only a rise in greenhouse gas emissions but also an increase in other atmospheric pollutants. Here, we consider the implications of rising levels of reactive nitrogen gases and their manifold interactions with crops and crop diseases.
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Affiliation(s)
- Helen N Fones
- Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK.
| | - Sarah J Gurr
- Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Rothamsted Research, North Wyke, Okehampton, EX20 2SB, UK
- Donder's Hon Chair, University of Utrecht, Padualaan 8, 3584 CH, Utrecht, The Netherlands
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Saremba BM, Tymm FJM, Baethke K, Rheault MR, Sherif SM, Saxena PK, Murch SJ. Plant signals during beetle (Scolytus multistriatus) feeding in American elm (Ulmus americana Planch). PLANT SIGNALING & BEHAVIOR 2017; 12:e1296997. [PMID: 28448744 PMCID: PMC5501226 DOI: 10.1080/15592324.2017.1296997] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 02/11/2017] [Accepted: 02/13/2017] [Indexed: 05/23/2023]
Abstract
American Elms were devastated by an outbreak of Dutch Elm Disease is caused by the fungus Ophiostoma novo-ulmi Brasier that originated in Asia and arrived in the early 1900s. In spite of decades of study, the specific mechanisms and disease resistance in some trees is not well understood. the fungus is spread by several species of bark beetles in the genus Scolytus, during their dispersal and feeding. Our objective was to understand elm responses to beetle feeding in the absence of the fungus to identify potential resistance mechanisms. A colony of Scolytus multistriatus was established from wild-caught beetles and beetles were co-incubated with susceptible or resistant American elm varieties in a controlled environment chamber. Beetles burrowed into the auxillary meristems of the young elm shoots. The trees responded to the beetle damage by a series of spikes in the concentration of plant growth regulating compounds, melatonin, serotonin, and jasmonic acid. Spikes in melatonin and serotonin represented a 7,000-fold increase over resting levels. Spikes in jasmonic acid were about 10-fold higher than resting levels with one very large spike observed. Differences were noted between susceptible and resistant elms that provide new understanding of plant defenses.
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Affiliation(s)
- Brett M. Saremba
- Biology, University of British Columbia, Kelowna, British Columbia, Canada
| | - Fiona J. M. Tymm
- Chemistry, University of British Columbia, Kelowna, British Columbia, Canada
| | - Kathy Baethke
- Chemistry, University of British Columbia, Kelowna, British Columbia, Canada
| | - Mark R. Rheault
- Biology, University of British Columbia, Kelowna, British Columbia, Canada
| | - Sherif M. Sherif
- Department of Plant Agriculture, University of Guelph, Guelph, Ontario, Canada
- Alson H. Smith Jr. Agricultural Research and Extension Center, Virginia Tech, Winchester, Virginia, USA
| | - Praveen K. Saxena
- Department of Plant Agriculture, University of Guelph, Guelph, Ontario, Canada
| | - Susan J. Murch
- Chemistry, University of British Columbia, Kelowna, British Columbia, Canada
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57
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Hoegger PJ, Rigling D, Holdenrieder O, Heiniger U. Cryphonectria radicalis: rediscovery of a lost fungus. Mycologia 2017. [DOI: 10.1080/15572536.2003.11833253] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | - Daniel Rigling
- WSL Swiss Federal Research Institute, CH-8903 Birmensdorf, Switzerland
| | | | - Ursula Heiniger
- WSL Swiss Federal Research Institute, CH-8903 Birmensdorf, Switzerland
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58
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Zhou X, de Beer ZW, Harrington TC, McNew D, Kirisits T, Wingfield MJ. Epitypification of Ophiostoma galeiforme and phylogeny of species in the O. galeiforme complex. Mycologia 2017. [DOI: 10.1080/15572536.2005.11832880] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- XuDong Zhou
- Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0002, South Africa
| | - Z. Wilhelm de Beer
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0002, South Africa
| | | | - Doug McNew
- Department of Plant Pathology, Iowa State University, Ames, Iowa 50011
| | - Thomas Kirisits
- Institute of Forest Entomology, Forest Pathology and Forest Protection (IFFF), Department of Forest and Soil Sciences, BOKU—University of Natural Resources and Applied Life Sciences, Hasenauerstrasse 38, A-1190 Vienna, Austria
| | - Michael J. Wingfield
- Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0002, South Africa
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59
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Landis FC, Gargas A. Using ITS2 secondary structure to create species-specific oligonucleotide probes for fungi. Mycologia 2017. [DOI: 10.1080/15572536.2007.11832532] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Frank C. Landis
- Botany Department, University of Wisconsin-Madison, Madison, Wisconsin 53706
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60
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Burgess TI, Crous CJ, Slippers B, Hantula J, Wingfield MJ. Tree invasions and biosecurity: eco-evolutionary dynamics of hitchhiking fungi. AOB PLANTS 2017; 8:plw076. [PMID: 27821517 PMCID: PMC5206332 DOI: 10.1093/aobpla/plw076] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 10/26/2016] [Indexed: 05/28/2023]
Abstract
When non-native plants reach novel environments, they typically arrive with hidden microbiomes. In general, most of these hitchhikers remain on their co-evolved hosts, some contribute to the invasiveness of their hosts, and a small number can undergo host shifts and move onto native hosts. Invasion success can vary depending upon the different categories of fungal associates. When an invader tree relies on a fungal mutualism to survive in the new environment, there is a fundamentally lower likelihood of either the tree, or the fungus, establishing novel associations. In contrast, parasitic hitchhikers could merely use their host plants to move through the landscape and to become established on new hosts (host shifts). Evidence suggests the frequency of these host shifts is low and depends upon the fungal functional group. However, epidemics caused by invasive pathogens in native ecosystems have occurred globally. Thus, elucidating the potential for hidden non-native fungi to form novel host associations in a new environment is important for biodiversity conservation.
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Affiliation(s)
- Treena I Burgess
- Centre of Phytophthora Science and Management, School of Veterinary and Life Science, Murdoch University, Murdoch 6150, Australia
- Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South Africa
| | - Casparus J Crous
- Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South Africa
- Present address: Centre for Ecology, Evolution and Environmental Changes, Faculty of Sciences, University of Lisbon, Campo Grande, Lisbon 1749-016, Portugal
| | - Bernard Slippers
- Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South Africa
| | - Jarkko Hantula
- Natural Resources Institute Finland, Natural Resources and Bioproduction Unit, Vantaa 01300, Finland
| | - Michael J Wingfield
- Centre of Phytophthora Science and Management, School of Veterinary and Life Science, Murdoch University, Murdoch 6150, Australia
- Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South Africa
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61
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Nigg M, Bernier L. From yeast to hypha: defining transcriptomic signatures of the morphological switch in the dimorphic fungal pathogen Ophiostoma novo-ulmi. BMC Genomics 2016; 17:920. [PMID: 27846799 PMCID: PMC5111228 DOI: 10.1186/s12864-016-3251-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 11/03/2016] [Indexed: 12/19/2022] Open
Abstract
Background Yeast-to-hypha transition is a major morphological change in fungi. Molecular regulators and pathways that are involved in this process have been extensively studied in model species, including Saccharomyces cerevisiae. The Mitogen-Actived Protein Kinase (MAPK) cascade, for example, is known to be involved in the yeast-to-pseudohypha switch. Yet the conservation of mechanisms regulating such morphological changes in non-model fungi is still poorly understood. Here, we investigate cell remodeling and transcriptomic modifications that occur during this morphological switch in the highly aggressive ascomycete fungus Ophiostoma novo-ulmi, the causal agent of Dutch elm disease. Results Using a combination of light microscopy, scanning electron microscopy and flow cytometry, we demonstrate that the morphological switch occurs in less than 27 h, with phenotypic cell modifications being detected within the first 4 h. Using RNAseq, we found that over 22% of the genome of O. novo-ulmi is differentially expressed during the transition. By performing clustering analyses of time series gene expression data, we identified several sets of genes that are differentially expressed according to distinct and representative temporal profiles. Further, we found that several genes that are homologous to S. cerevisiae MAPK genes are regulated during the yeast-to-hypha transition in O. novo-ulmi and mostly over-expressed, suggesting convergence in gene expression regulation. Conclusions Our results are the first report of a time-course experiment monitoring the morphological transition in a non-model Sordariomycota species and reveal many genes of interest for further functional investigations of fungal dimorphism. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3251-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- M Nigg
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Room 2255, Pavillon Charles-Eugène-Marchand, 1030, Avenue de la Médecine, Québec, Québec, G1V 0A6, Canada. .,Département des sciences du bois et de la forêt, Centre d'Étude de la Forêt (CEF), Université Laval, Québec, G1V 0A6, Canada.
| | - L Bernier
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Room 2255, Pavillon Charles-Eugène-Marchand, 1030, Avenue de la Médecine, Québec, Québec, G1V 0A6, Canada.,Département des sciences du bois et de la forêt, Centre d'Étude de la Forêt (CEF), Université Laval, Québec, G1V 0A6, Canada
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62
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Thousand Cankers Disease Complex: A Forest Health Issue that Threatens Juglans Species across the U.S. FORESTS 2016. [DOI: 10.3390/f7110260] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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63
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Ophiostomatoid fungi associated with mangroves in South Africa, including Ophiostoma palustre sp. nov. Antonie van Leeuwenhoek 2016; 109:1555-1571. [PMID: 27562287 DOI: 10.1007/s10482-016-0757-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 08/17/2016] [Indexed: 10/21/2022]
Abstract
Mangrove trees are continuously under stress due to environmental and/or anthropogenic pressures, which expose them to attack by pathogens, compromising their survival. Ophiostomatoid fungi cause sap stain and diseases of a wide spectrum of tree species globally. These fungi infect trees through natural, insect, animal and/or human made wounds. During routine surveys of mangrove trees in South Africa, wounds on branches and stems of Avicennia marina were regularly monitored for the presence of ophiostomatoid fungi at ten study sites in the country. The stems of four mangrove species, A. marina, Bruguiera gymnorrhiza, Rhizophora mucronata and Barringtonia racemosa were also wounded and evaluated for the appearance of these fungi. Ophiostomatoid fungi were obtained from the mangrove associate B. racemosa, but not from any of the true mangroves. Analyses of DNA sequence data for the internal transcribed spacer, β-tubulin, calmodulin and translation elongation factor gene regions revealed that the fungi isolated from the wounds on B. racemosa belong to three species in the Ophiostomataceae, including a new taxon described here as Ophiostoma palustre sp. nov. These results suggest that the mangrove associate B. racemosa is more prone to colonization by ophiostomatoid fungi than the true mangroves.
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64
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Maharachchikumbura SSN, Hyde KD, Jones EBG, McKenzie EHC, Bhat JD, Dayarathne MC, Huang SK, Norphanphoun C, Senanayake IC, Perera RH, Shang QJ, Xiao Y, D’souza MJ, Hongsanan S, Jayawardena RS, Daranagama DA, Konta S, Goonasekara ID, Zhuang WY, Jeewon R, Phillips AJL, Abdel-Wahab MA, Al-Sadi AM, Bahkali AH, Boonmee S, Boonyuen N, Cheewangkoon R, Dissanayake AJ, Kang J, Li QR, Liu JK, Liu XZ, Liu ZY, Luangsa-ard JJ, Pang KL, Phookamsak R, Promputtha I, Suetrong S, Stadler M, Wen T, Wijayawardene NN. Families of Sordariomycetes. FUNGAL DIVERS 2016. [DOI: 10.1007/s13225-016-0369-6] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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65
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Máliš F, Kopecký M, Petřík P, Vladovič J, Merganič J, Vida T. Life stage, not climate change, explains observed tree range shifts. GLOBAL CHANGE BIOLOGY 2016; 22:1904-1914. [PMID: 26725258 PMCID: PMC5424071 DOI: 10.1111/gcb.13210] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 10/14/2015] [Accepted: 11/25/2015] [Indexed: 06/05/2023]
Abstract
Ongoing climate change is expected to shift tree species distribution and therefore affect forest biodiversity and ecosystem services. To assess and project tree distributional shifts, researchers may compare the distribution of juvenile and adult trees under the assumption that differences between tree life stages reflect distributional shifts triggered by climate change. However, the distribution of tree life stages could differ within the lifespan of trees, therefore, we hypothesize that currently observed distributional differences could represent shifts over ontogeny as opposed to climatically driven changes. Here, we test this hypothesis with data from 1435 plots resurveyed after more than three decades across the Western Carpathians. We compared seedling, sapling and adult distribution of 12 tree species along elevation, temperature and precipitation gradients. We analyzed (i) temporal shifts between the surveys and (ii) distributional differences between tree life stages within both surveys. Despite climate warming, tree species distribution of any life stage did not shift directionally upward along elevation between the surveys. Temporal elevational shifts were species specific and an order of magnitude lower than differences among tree life stages within the surveys. Our results show that the observed range shifts among tree life stages are more consistent with ontogenetic differences in the species' environmental requirements than with responses to recent climate change. The distribution of seedlings substantially differed from saplings and adults, while the distribution of saplings did not differ from adults, indicating a critical transition between seedling and sapling tree life stages. Future research has to take ontogenetic differences among life stages into account as we found that distributional differences recently observed worldwide may not reflect climate change but rather the different environmental requirements of tree life stages.
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Affiliation(s)
- František Máliš
- Faculty of Forestry, Technical University in Zvolen, T.G. Masaryka 24, SK-960 53, Zvolen, Slovak Republic
- Forest Research Institute Zvolen, National Forest Centre, T.G. Masaryka 22, SK-960 52, Zvolen, Slovak Republic
| | - Martin Kopecký
- Department of Vegetation Ecology, Institute of Botany, The Czech Academy of Sciences, Lidická 25/27, CZ-602 00, Brno, Czech Republic
| | - Petr Petřík
- Department of GIS and Remote Sensing, Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
| | - Jozef Vladovič
- Forest Research Institute Zvolen, National Forest Centre, T.G. Masaryka 22, SK-960 52, Zvolen, Slovak Republic
| | - Ján Merganič
- Faculty of Forestry, Technical University in Zvolen, T.G. Masaryka 24, SK-960 53, Zvolen, Slovak Republic
| | - Tomáš Vida
- Faculty of Forestry, Technical University in Zvolen, T.G. Masaryka 24, SK-960 53, Zvolen, Slovak Republic
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66
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Aylward J, Steenkamp ET, Dreyer LL, Roets F, Wingfield BD, Wingfield MJ. Genome sequences of Knoxdaviesia capensis and K. proteae (Fungi: Ascomycota) from Protea trees in South Africa. Stand Genomic Sci 2016; 11:22. [PMID: 26933475 PMCID: PMC4772463 DOI: 10.1186/s40793-016-0139-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 02/18/2016] [Indexed: 11/10/2022] Open
Abstract
Two closely related ophiostomatoid fungi, Knoxdaviesia capensis and K. proteae, inhabit the fruiting structures of certain Protea species indigenous to southern Africa. Although K. capensis occurs in several Protea hosts, K. proteae is confined to P. repens. In this study, the genomes of K. capensis CBS139037 and K. proteae CBS140089 are determined. The genome of K. capensis consists of 35,537,816 bp assembled into 29 scaffolds and 7940 predicted protein-coding genes of which 6192 (77.98 %) could be functionally classified. K. proteae has a similar genome size of 35,489,142 bp that is comprised of 133 scaffolds. A total of 8173 protein-coding genes were predicted for K. proteae and 6093 (74.55 %) of these have functional annotations. The GC-content of both genomes is 52.8 %.
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Affiliation(s)
- Janneke Aylward
- Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland, 7602 South Africa
| | - Emma T Steenkamp
- Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, 0002 South Africa
| | - Léanne L Dreyer
- Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland, 7602 South Africa
| | - Francois Roets
- Department of Conservation Ecology and Entomology, Stellenbosch University, Private Bag X1, Matieland, 7602 South Africa
| | - Brenda D Wingfield
- Department of Genetics, University of Pretoria, Pretoria, 0002 South Africa
| | - Michael J Wingfield
- Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, 0002 South Africa
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Sherif SM, Shukla MR, Murch SJ, Bernier L, Saxena PK. Simultaneous induction of jasmonic acid and disease-responsive genes signifies tolerance of American elm to Dutch elm disease. Sci Rep 2016; 6:21934. [PMID: 26902398 PMCID: PMC4763294 DOI: 10.1038/srep21934] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 02/03/2016] [Indexed: 01/07/2023] Open
Abstract
Dutch elm disease (DED), caused by three fungal species in the genus Ophiostoma, is the most devastating disease of both native European and North American elm trees. Although many tolerant cultivars have been identified and released, the tolerance mechanisms are not well understood and true resistance has not yet been achieved. Here we show that the expression of disease-responsive genes in reactions leading to tolerance or susceptibility is significantly differentiated within the first 144 hours post-inoculation (hpi). Analysis of the levels of endogenous plant defense molecules such as jasmonic acid (JA) and salicylic acid (SA) in tolerant and susceptible American elm saplings suggested SA and methyl-jasmonate as potential defense response elicitors, which was further confirmed by field observations. However, the tolerant phenotype can be best characterized by a concurrent induction of JA and disease-responsive genes at 96 hpi. Molecular investigations indicated that the expression of fungal genes (i.e. cerato ulmin) was also modulated by endogenous SA and JA and this response was unique among aggressive and non-aggressive fungal strains. The present study not only provides better understanding of tolerance mechanisms to DED, but also represents a first, verified template for examining simultaneous transcriptomic changes during American elm-fungus interactions.
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Affiliation(s)
- S. M. Sherif
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada,Department of Horticulture, Faculty of Agriculture, Damanhour University, Al-Gomhuria St., PO Box 22516, Damanhour, Al-Behira, Egypt
| | - M. R. Shukla
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada
| | - S. J. Murch
- Chemistry Department, University of British Columbia, Kelowna, BC, Canada
| | - L. Bernier
- Centre d’étude de la forêt (CEF) and Institut de biologie intégrative et des systèmes (IBIS), Université Laval, Québec City, QC, Canada
| | - P. K. Saxena
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada,
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68
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Wedge MÈ, Naruzawa ES, Nigg M, Bernier L. Diversity in yeast-mycelium dimorphism response of the Dutch elm disease pathogens: the inoculum size effect. Can J Microbiol 2016; 62:525-9. [PMID: 27068623 DOI: 10.1139/cjm-2015-0795] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dutch elm disease (DED) is caused by the dimorphic fungi Ophiostoma ulmi, Ophiostoma novo-ulmi, and Ophiostoma himal-ulmi. A cell population density-dependent phenomenon related to quorum sensing was previously shown to affect the reversible transition from yeast-like to mycelial growth in liquid shake cultures of O. novo-ulmi NRRL 6404. Since the response to external stimuli often varies among DED fungal strains, we evaluated the effect of inoculum size on 8 strains of the 3 species of DED agents by determining the proportion of yeast and mycelium produced at different spore inoculum concentrations in defined liquid shake medium. The results show that not all DED fungi strains respond similarly to inoculum size effect, since variations were observed among strains. It is thus possible that the different strains belonging to phylogenetically close species use different signalling molecules or molecular signalling pathways to regulate their growth mode via quorum-sensing mechanisms.
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Affiliation(s)
- Marie-Ève Wedge
- Centre d'Étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6, Canada.,Centre d'Étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6, Canada
| | - Erika Sayuri Naruzawa
- Centre d'Étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6, Canada.,Centre d'Étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6, Canada
| | - Martha Nigg
- Centre d'Étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6, Canada.,Centre d'Étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6, Canada
| | - Louis Bernier
- Centre d'Étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6, Canada.,Centre d'Étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), Pavillon Charles-Eugène-Marchand, 1030 avenue de la Médecine, Québec, QC G1V 0A6, Canada
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69
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Ratti C, Iotti M, Zambonelli A, Terlizzi F. Mycoviruses Infecting True Truffles. SOIL BIOLOGY 2016. [DOI: 10.1007/978-3-319-31436-5_20] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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70
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Yin M, Wingfield MJ, Zhou X, de Beer ZW. Multigene phylogenies and morphological characterization of five new Ophiostoma spp. associated with spruce-infesting bark beetles in China. Fungal Biol 2015; 120:454-470. [PMID: 27020148 DOI: 10.1016/j.funbio.2015.12.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 12/18/2015] [Accepted: 12/19/2015] [Indexed: 10/22/2022]
Abstract
Ophiostoma spp. (Ophiostomatales, Ascomycota) are well-known fungi associated with bark beetles (Coleoptera: Scolytinae). Some of these are serious tree pathogens, while the majority is blue-stain agents of timber. In recent years, various bark beetle species have been attacking spruce forests in Qinghai province, China, causing significant damage. A preliminary survey was done to explore the diversity of the ophiostomatoid fungal associates of these beetles. The aims of the present study were to identify and characterize new Ophiostoma spp. associated with spruce-infesting bark beetles in Qinghai Province, and to resolve phylogenetic relationships of Ophiostoma spp. related to the Chinese isolates, using multigene phylogenetic analyses. Results obtained from four gene regions (ribosomal internal transcribed spacer regions, β-tubulin, calmodulin, translation elongation factor-1α) revealed five new Ophiostoma spp. from Qinghai. These included O. nitidus sp. nov., O. micans sp. nov., and O. qinghaiense sp. nov. in a newly defined O. piceae complex. The other two new species, O. poligraphi sp. nov. and O. shangrilae sp. nov., grouped in the O. brunneo-ciliatum complex. Based on DNA sequence and morphological comparisons, we also show that O. arduennense and O. torulosum are synonyms of O. distortum, while O. setosum is a synonym of O. cupulatum.
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Affiliation(s)
- Mingliang Yin
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, Gauteng Province, South Africa; China Eucalypt Research Centre (CERC), Chinese Academy of Forestry (CAF), Zhanjiang 524022, Guangdong Province, China
| | - Michael J Wingfield
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, Gauteng Province, South Africa
| | - Xudong Zhou
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, Gauteng Province, South Africa; China Eucalypt Research Centre (CERC), Chinese Academy of Forestry (CAF), Zhanjiang 524022, Guangdong Province, China
| | - Z Wilhelm de Beer
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, Gauteng Province, South Africa.
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71
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de Sain M, Rep M. The Role of Pathogen-Secreted Proteins in Fungal Vascular Wilt Diseases. Int J Mol Sci 2015; 16:23970-93. [PMID: 26473835 PMCID: PMC4632733 DOI: 10.3390/ijms161023970] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 09/10/2015] [Accepted: 09/11/2015] [Indexed: 01/07/2023] Open
Abstract
A limited number of fungi can cause wilting disease in plants through colonization of the vascular system, the most well-known being Verticillium dahliae and Fusarium oxysporum. Like all pathogenic microorganisms, vascular wilt fungi secrete proteins during host colonization. Whole-genome sequencing and proteomics screens have identified many of these proteins, including small, usually cysteine-rich proteins, necrosis-inducing proteins and enzymes. Gene deletion experiments have provided evidence that some of these proteins are required for pathogenicity, while the role of other secreted proteins remains enigmatic. On the other hand, the plant immune system can recognize some secreted proteins or their actions, resulting in disease resistance. We give an overview of proteins currently known to be secreted by vascular wilt fungi and discuss their role in pathogenicity and plant immunity.
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Affiliation(s)
- Mara de Sain
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam 1098XH, The Netherlands.
| | - Martijn Rep
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam 1098XH, The Netherlands.
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RNAseq Analysis Highlights Specific Transcriptome Signatures of Yeast and Mycelial Growth Phases in the Dutch Elm Disease Fungus Ophiostoma novo-ulmi. G3-GENES GENOMES GENETICS 2015; 5:2487-95. [PMID: 26384770 PMCID: PMC4632067 DOI: 10.1534/g3.115.021022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Fungal dimorphism is a complex trait and our understanding of the ability of fungi to display different growth morphologies is limited to a small number of model species. Here we study a highly aggressive dimorphic fungus, the ascomycete Ophiostoma novo-ulmi, which is a model in plant pathology and the causal agent of Dutch elm disease. The two growth phases that this fungus displays, i.e., a yeast phase and mycelial phase, are thought to be involved in key steps of disease development. We used RNAseq to investigate the genome-wide gene expression profiles that are associated with yeast and mycelial growth phases in vitro. Our results show a clear molecular distinction between yeast and mycelial phase gene expression profiles. Almost 12% of the gene content is differentially expressed between the two phases, which reveals specific functions related to each growth phase. We compared O. novo-ulmi transcriptome profiles with those of two model dimorphic fungi, Candida albicans and Histoplasma capsulatum. Few orthologs showed similar expression regulation between the two growth phases, which suggests that, globally, the genes associated with these two life forms are poorly conserved. This poor conservation underscores the importance of developing specific tools for emerging model species that are distantly related to the classical ones. Taken together, our results provide insights into transcriptome regulation and molecular specificity in O. novo-ulmi and offer a new perspective for understanding fungal dimorphism.
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73
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Migliorini D, Ghelardini L, Tondini E, Luchi N, Santini A. The potential of symptomless potted plants for carrying invasive soilborne plant pathogens. DIVERS DISTRIB 2015. [DOI: 10.1111/ddi.12347] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Duccio Migliorini
- Dipartimento di Scienze delle Produzioni Agroalimentari e dell'Ambiente DiSPAA; Università di Firenze; Piazzale delle Cascine 28 50144 Firenze Italy
| | - Luisa Ghelardini
- Institute for Sustainable Plant Protection IPSP; National Research Council C.N.R.; Via Madonna del Piano 10 50019 Sesto Fiorentino Italy
| | - Elena Tondini
- Institute for Sustainable Plant Protection IPSP; National Research Council C.N.R.; Via Madonna del Piano 10 50019 Sesto Fiorentino Italy
| | - Nicola Luchi
- Institute for Sustainable Plant Protection IPSP; National Research Council C.N.R.; Via Madonna del Piano 10 50019 Sesto Fiorentino Italy
| | - Alberto Santini
- Institute for Sustainable Plant Protection IPSP; National Research Council C.N.R.; Via Madonna del Piano 10 50019 Sesto Fiorentino Italy
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74
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Bertolasi B, Leonarduzzi C, Piotti A, Leonardi S, Zago L, Gui L, Gorian F, Vanetti I, Binelli G. A last stand in the Po valley: genetic structure and gene flow patterns in Ulmus minor and U. pumila. ANNALS OF BOTANY 2015; 115:683-92. [PMID: 25725008 PMCID: PMC4343291 DOI: 10.1093/aob/mcu256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Ulmus minor has been severely affected by Dutch elm disease (DED). The introduction into Europe of the exotic Ulmus pumila, highly tolerant to DED, has resulted in it widely replacing native U. minor populations. Morphological and genetic evidence of hybridization has been reported, and thus there is a need for assessment of interspecific gene flow patterns in natural populations. This work therefore aimed at studying pollen gene flow in a remnant U. minor stand surrounded by trees of both species scattered across an agricultural landscape. METHODS All trees from a small natural stand (350 in number) and the surrounding agricultural area within a 5-km radius (89) were genotyped at six microsatellite loci. Trees were morphologically characterized as U. minor, U. pumila or intermediate phenotypes, and morphological identification was compared with Bayesian clustering of genotypes. For paternity analysis, seeds were collected in two consecutive years from 20 and 28 mother trees. Maximum likelihood paternity assignment was used to elucidate intra- and interspecific gene flow patterns. KEY RESULTS Genetic structure analyses indicated the presence of two genetic clusters only partially matching the morphological identification. The paternity analysis results were consistent between the two consecutive years of sampling and showed high pollen immigration rates (∼0·80) and mean pollination distances (∼3 km), and a skewed distribution of reproductive success. Few intercluster pollinations and putative hybrid individuals were found. CONCLUSIONS Pollen gene flow is not impeded in the fragmented agricultural landscape investigated. High pollen immigration and extensive pollen dispersal distances are probably counteracting the potential loss of genetic variation caused by isolation. Some evidence was also found that U. minor and U. pumila can hybridize when in sympatry. Although hybridization might have beneficial effects on both species, remnant U. minor populations represent a valuable source of genetic diversity that needs to be preserved.
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Affiliation(s)
- B Bertolasi
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - C Leonarduzzi
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - A Piotti
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - S Leonardi
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - L Zago
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - L Gui
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - F Gorian
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - I Vanetti
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - G Binelli
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
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Barnes I, Wingfield MJ, Carbone I, Kirisits T, Wingfield BD. Population structure and diversity of an invasive pine needle pathogen reflects anthropogenic activity. Ecol Evol 2014; 4:3642-61. [PMID: 25478155 PMCID: PMC4224538 DOI: 10.1002/ece3.1200] [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: 06/30/2014] [Accepted: 07/02/2014] [Indexed: 11/09/2022] Open
Abstract
Dothistroma septosporum is a haploid fungal pathogen that causes a serious needle blight disease of pines, particularly as an invasive alien species on Pinus radiata in the Southern Hemisphere. During the course of the last two decades, the pathogen has also incited unexpected epidemics on native and non-native pine hosts in the Northern Hemisphere. Although the biology and ecology of the pathogen has been well documented, there is a distinct lack of knowledge regarding its movement or genetic diversity in many of the countries where it is found. In this study we determined the global population diversity and structure of 458 isolates of D. septosporum from 14 countries on six continents using microsatellite markers. Populations of the pathogen in the Northern Hemisphere, where pines are native, displayed high genetic diversities and included both mating types. Most of the populations from Europe showed evidence for random mating, little population differentiation and gene flow between countries. Populations in North America (USA) and Asia (Bhutan) were genetically distinct but migration between these continents and Europe was evident. In the Southern Hemisphere, the population structure and diversity of D. septosporum reflected the anthropogenic history of the introduction and establishment of plantation forestry, particularly with Pinus radiata. Three introductory lineages in the Southern Hemisphere were observed. Countries in Africa, that have had the longest history of pine introductions, displayed the greatest diversity in the pathogen population, indicating multiple introductions. More recent introductions have occurred separately in South America and Australasia where the pathogen population is currently reproducing clonally due to the presence of only one mating type.
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Affiliation(s)
- Irene Barnes
- Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria Pretoria, 0002, South Africa
| | - Michael J Wingfield
- Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria Pretoria, 0002, South Africa
| | - Ignazio Carbone
- Department of Plant Pathology, Center for Integrated Fungal Research, North Carolina State University Raleigh, North Carolina, 27695
| | - Thomas Kirisits
- Department of Forest and Soil Sciences (DFS), Institute of Forest Entomology, Forest Pathology and Forest Protection (IFFF), University of Natural Resources and Life Sciences, Vienna (BOKU) Vienna, Austria
| | - Brenda D Wingfield
- Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria Pretoria, 0002, South Africa
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76
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Sherif S, Jones AMP, Shukla MR, Saxena PK. Establishment of invasive and non-invasive reporter systems to investigate American elm-Ophiostoma novo-ulmi interactions. Fungal Genet Biol 2014; 71:32-41. [PMID: 25139300 DOI: 10.1016/j.fgb.2014.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 08/06/2014] [Accepted: 08/08/2014] [Indexed: 11/18/2022]
Abstract
Dutch elm disease (DED), caused by ascomycete fungi in the Ophiostoma genus, is the most devastating disease of American elm (Ulmus americana) trees. Cerato ulmin (CU), a hydrophobin secreted by the fungus, has been implicated in the development of DED, but its role in fungal pathogenicity and virulence remains uncertain and controversial. Here, we describe reporter systems based on the CU promoter and three reporter proteins (GFP, GUS and LUC), developed as research tools for quantitative and qualitative studies of DED in vitro, in vivo and in planta. A strain of the aggressive species Ophiostoma novo-ulmi was transformed with the reporter constructs using Agrobacterium-mediated transformation and the fungal transformants, namely M75-GFP, M75-GUS and M75-LUC, were examined for mitotic stability after repeated subcultures. The intensity of GFP fluorescence was strong in M75-GFP spores and hyphae, allowing microscopic investigations of spore structure, fungal morphogenesis and fungal development. The interaction of M75-GFP and U. americana callus cells was explored with scanning laser confocal microscopy facilitating qualitative studies on fungal strategies for the invasion and penetration of elm cells. M75-GUS was generated to provide an invasive, yet quantitative approach to study fungal-plant interactions in vitro and in planta. The generation of M75-LUC transformants was aimed at providing a non-destructive quantitative approach to study the role of CU in vivo. The sensitivity, low background signal and linearity of LUC assays all predict a very reliable approach to investigate and re-test previously claimed roles of this CU in fungal pathogenicity. These reporter systems provide new tools to investigate plant-pathogen interactions in this complex pathosystem and may aid in better understanding the development of DED.
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Affiliation(s)
- S Sherif
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada; Department of Horticulture, Faculty of Agriculture, Damanhour University, Al-Gomhuria St., PO Box 22516, Damanhour, Al-Behira, Egypt
| | - A M P Jones
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - M R Shukla
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - P K Saxena
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada.
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77
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Naruzawa ES, Bernier L. Control of yeast-mycelium dimorphism in vitro in Dutch elm disease fungi by manipulation of specific external stimuli. Fungal Biol 2014; 118:872-84. [PMID: 25442291 DOI: 10.1016/j.funbio.2014.07.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 07/18/2014] [Accepted: 07/30/2014] [Indexed: 10/24/2022]
Abstract
Dutch elm disease (DED) fungi exhibit yeast-mycelium dimorphism both in planta and in vitro. However, previously published data on the transition between these two growth forms in vitro were mostly obtained from a single strain. We examined the effect of six factors on yeast-mycelium dimorphism in vitro in ten strains of Ophiostoma ulmi, Ophiostoma novo-ulmi and Ophiostoma himal-ulmi. Nitrogen sources, calcium, and yeast extract, altogether with inhibitors of phosphodiesterase (caffeine) and dioxygenases (propyl gallate and salicylic acid) were tested in defined culture media. Morphological response to manipulation of several of these factors varied according to the strain of Ophiostoma being analysed. Responses ranged from no statistical differences in morphological transitions to stimulation or reversion of yeast-mycelium dimorphism with the treatments that were tested. These results suggest that different mechanisms and pathways operate in the control of the yeast-mycelium transition in DED pathogens. Oxylipins could be involved in the yeast-to-mycelium transition, since the addition of a dioxygenase inhibitor, salicylic acid, reduced mycelium production in all strains that were tested.
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Affiliation(s)
- Erika Sayuri Naruzawa
- Centre d'Étude de la Forêt (CEF) and Institut de Biologie intégrative et des Systèmes (IBIS), Canada
| | - Louis Bernier
- Centre d'Étude de la Forêt (CEF) and Institut de Biologie intégrative et des Systèmes (IBIS), Canada.
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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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79
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Uchendu EE, Shukla MR, Reed BM, Saxena PK. Melatonin enhances the recovery of cryopreserved shoot tips of American elm (Ulmus americana L.). J Pineal Res 2013; 55:435-42. [PMID: 24117864 DOI: 10.1111/jpi.12094] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 09/06/2013] [Indexed: 01/13/2023]
Abstract
Climate change and global migrations of people and goods have exposed trees to new diseases and abiotic challenges that threaten the survival of species. In vitro germplasm storage via cryopreservation is an effective tool to ensure conservation of tree species, but plant cells and tissues are exposed to multiple stresses during the cryopreservation process. The current study was designed to evaluate the potential of melatonin to improve survival through the process of cryopreservation. Shoot tips of in vitro-grown plantlets and dormant winter buds of American elm were successfully cryopreserved in liquid nitrogen (LN) at -196°C under controlled environmental conditions following melatonin treatment and cold acclimation with either vitrification or encapsulation–vitrification protocols. Explants had optimal regrowth following cryopreservation when treated with the plant vitrification solution#2 (PVS2) for 10 min. Supplementation of both preculture and regrowth media with melatonin significantly enhanced regrowth of frozen shoots compared with the untreated control (P < 0.05). Approximately 80–100% of shoot explants grew under optimized conditions using melatonin-enriched media. Shoot tips of dormant winter buds consistently produced nearly 100% regrowth with both techniques. The main steps of the optimized protocol are14-day cold-acclimated cultures exposed to preculture medium with 0.1–0.5 lM melatonin for 24 hr, application of PVS2 for 10 min, rapid cooling in LN, rapid rewarming, removal of cryoprotectants, and recovery on a medium supplemented with 0.1–0.5 lM melatonin. Our results demonstrate the usefulness of the antioxidant melatonin for long-term storage of naturally resistant elm germplasm.
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Abstract
The interactions among insects, mites, and fungi are diverse and complex but poorly understood in most cases. Associations among insects, mites, and fungi span an almost incomprehensible array of ecological interactions and evolutionary histories. Insects and mites often share habitats and resources and thus interact within communities. Many mites and insects rely on fungi for nutrients, and fungi benefit from them with regard to spore dispersal, habitat provision, or nutrient resources. Mites have important impacts on community dynamics, ecosystem processes, and biodiversity within many insect-fungus systems. Given that mites are understudied but highly abundant, they likely have bigger, more important, and more widespread impacts on communities than previously recognized. We describe mutualistic and antagonistic effects of mites on insect-fungus associations, explore the processes that underpin ecological and evolutionary patterns of these multipartite communities, review well-researched examples of the effects of mites on insect-fungus associations, and discuss approaches for studying mites within insect-fungus communities.
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Affiliation(s)
- R W Hofstetter
- College of Engineering, Forestry, and Natural Sciences, Northern Arizona University, Flagstaff, Arizona 86011;
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81
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Kolařík M, Jankowiak R. Vector affinity and diversity of Geosmithia fungi living on subcortical insects inhabiting Pinaceae species in central and northeastern Europe. MICROBIAL ECOLOGY 2013; 66:682-700. [PMID: 23624540 DOI: 10.1007/s00248-013-0228-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 04/08/2013] [Indexed: 06/02/2023]
Abstract
Fungi from the genus Geosmithia (Ascomycota: Hypocreales) are associated with bark beetles (Coleoptera: Scolytinae), though little is known about ecology, diversity, and distribution of these fungi across beetle and its host tree species. This study surveyed the diversity, distribution and vector affinity of Geosmithia isolated from subcortical insects that colonized trees from the family Pinaceae in Central and Northeastern Europe. Twelve Geosmithia species were isolated from 85 plant samples associated with 23 subcortical insect species (including 14 bark beetle species). Geosmithia community composition was similar across different localities and vector species; although the fungal communities associated with insects that colonized Pinus differed from that colonizing other tree species (Abies, Larix, and Picea). Ten Geosmithia species from four independent phylogenetic lineages were not reported previously from vectors feeding on other plant families and seem to be restricted to the vectors from Pinaceae only. We conclude that presence of such substrate specificity suggests a long and stable association between Geosmithia and bark beetles.
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Affiliation(s)
- Miroslav Kolařík
- Institute of Microbiology of the ASCR, v. v. i., Vídeňská 1083, 142 20, Prague 4, Czech Republic,
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82
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Hintz WE, Carneiro JS, Kassatenko I, Varga A, James D. Two novel mitoviruses from a Canadian isolate of the Dutch elm pathogen Ophiostoma novo-ulmi (93-1224). Virol J 2013; 10:252. [PMID: 23924036 PMCID: PMC3750502 DOI: 10.1186/1743-422x-10-252] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 08/07/2013] [Indexed: 11/10/2022] Open
Abstract
Background Ophiostoma novo-ulmi is the causative agent of Dutch elm disease (DED). It is an ascomycetous filamentous fungus that ranks as the third most devastating fungal pathogen in Canada. The disease front has spread eastward and westward from the epicentre in Ontario and Quebec and is threatening elm populations across the country. Numerous mitigation strategies have been tried to eradicate this pathogen, but success has thus far been limited. An alternative approach might utilize double-stranded RNA (dsRNA) mycoviruses which have been reported to induce hypovirulence in other fungi. Methods Using a modified single primer amplification technique (SPAT) in combination with chromosomal walking, we have determined the genome sequence of two RdRp encoding dsRNA viruses from an O. novo-ulmi isolate (93–1224) collected from the disease front in Winnipeg. Results We propose that these viruses, which we have named OnuMV1c and OnuMV7 based on sequence similarity to other Ophiostoma mitoviruses, are two new members of the genus Mitovirus in the family Narnaviridae. Conclusions The discovery of such dsRNA elements raises the potential for engineering these viruses to include other genetic elements, such as anti-sense or interfering RNAs, to create novel and highly specific biological controls. Naïve fungal hosts could be infected with both the engineered molecule and a helper mitovirus encoding an RdRp which would provide replication capacity for both molecules.
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Affiliation(s)
- William E Hintz
- Department of Biology, University of Victoria, P.O. Box 3020 STN CSC, Victoria, BC V8W 3N5, Canada.
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83
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McCarthy JK, Didham RK, Brockerhoff EG, van Bysterveldt KA, Varsani A. High-resolution DNA melt-curve analysis for cost-effective mass screening of pairwise species interactions. Mol Ecol Resour 2013; 13:908-17. [PMID: 23875939 DOI: 10.1111/1755-0998.12143] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 06/05/2013] [Indexed: 11/28/2022]
Abstract
Ecological studies of pairwise interactions are constrained by the methods available for rapid species identification of the interacting organisms. The resolution of data required to characterize species interaction networks at multiple spatio-temporal scales can be intensive, and therefore laborious and costly to collect. We explore the utility of high-resolution DNA melt-curve analysis (HRM) as a rapid species identification method. An approach was developed to identify organisms at the pairwise interaction level, with particular application to cryptic species interactions that are traditionally difficult to study. Here, we selected a challenging application; to identify the presence/absence of pathogenic fungi (Sporothrix inflata, Ophiostoma nigrocarpum and Ophiostoma galeiforme) transported by bark beetle vectors (Hylastes ater and Hylurgus ligniperda). The technique was able to distinguish between different species of DNA within a single, pooled sample. In test applications, HRM was effective in the mass screening and identification of pathogenic fungal species carried by many individual bark beetle vectors (n = 455 beetles screened) across large geographic scales. For two of the fungal species, there was no difference in the frequency of association with either of their vectors, but for the third fungal species there was a shift in vector-pathogen associations across locations. This technique allows rapid, mass screening and characterization of species interactions at a fraction of the time and cost of traditional methods. It is anticipated that this method can be readily applied to explore other cryptic species interactions, or other studies requiring rapid generation of large data sets and/or high-throughput efficiency.
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Affiliation(s)
- James K McCarthy
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
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84
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Hybridization and introgression between the exotic Siberian elm, Ulmus pumila, and the native Field elm, U. minor, in Italy. Biol Invasions 2013. [DOI: 10.1007/s10530-013-0486-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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85
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Fontaine MC, Gladieux P, Hood ME, Giraud T. History of the invasion of the anther smut pathogen on Silene latifolia in North America. THE NEW PHYTOLOGIST 2013; 198:946-956. [PMID: 23406496 DOI: 10.1111/nph.12177] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 01/09/2013] [Indexed: 06/01/2023]
Abstract
Understanding the routes of pathogen introduction contributes greatly to efforts to protect against future disease emergence. Here, we investigated the history of the invasion in North America by the fungal pathogen Microbotryum lychnidis-dioicae, which causes the anther smut disease on the white campion Silene latifolia. This system is a well-studied model in evolutionary biology and ecology of infectious disease in natural systems. Analyses based on microsatellite markers show that the introduced American M. lychnidis-dioicae probably came from Scotland, from a single population, and thus suffered from a drastic bottleneck compared with genetic diversity in the native European range. The pattern in M. lychnidis-dioicae contrasts with that found by previous studies in its host plant species S. latifolia, also introduced in North America. In the plant, several European lineages have been introduced from across Europe. The smaller number of introductions for M. lychnidis-dioicae probably relates to its life history traits, as it is an obligate, specialized pathogen that is neither transmitted by the seeds nor persistent in the environment. The results show that even a nonagricultural, biotrophic, and insect-vectored pathogen suffering from a very strong bottleneck can successfully establish populations on its introduced host.
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Affiliation(s)
- Michael C Fontaine
- Université Paris-Sud, Laboratoire Ecologie, Systématique et Evolution, UMR8079, Orsay Cedex, F-91405, France
- CNRS, UMR 8079, Orsay Cedex, F-91405, France
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Pierre Gladieux
- Université Paris-Sud, Laboratoire Ecologie, Systématique et Evolution, UMR8079, Orsay Cedex, F-91405, France
- CNRS, UMR 8079, Orsay Cedex, F-91405, France
- Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Michael E Hood
- Department of Biology, Amherst College, Amherst, MA, USA
| | - Tatiana Giraud
- Université Paris-Sud, Laboratoire Ecologie, Systématique et Evolution, UMR8079, Orsay Cedex, F-91405, France
- CNRS, UMR 8079, Orsay Cedex, F-91405, France
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86
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Fontaine MC, Austerlitz F, Giraud T, Labbé F, Papura D, Richard-Cervera S, Delmotte F. Genetic signature of a range expansion and leap-frog event after the recent invasion of Europe by the grapevine downy mildew pathogenPlasmopara viticola. Mol Ecol 2013; 22:2771-86. [DOI: 10.1111/mec.12293] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 02/11/2013] [Accepted: 02/14/2013] [Indexed: 01/26/2023]
Affiliation(s)
- Michael C. Fontaine
- Ecologie, Systématique et Evolution; UMR 8079 Université Paris Sud Laboratoire Ecologie; Systematique et Evolution; UMR8079 Orsay Cedex F-91405 France
- Eco-Anthropologie et Ethnobiologie; UMR 7206 CNRS; MNHN; Univ Paris Diderot; Sorbonne Paris Cité F-75231 Paris Cedex 5 France
| | - Fréderic Austerlitz
- Ecologie, Systématique et Evolution; UMR 8079 Université Paris Sud Laboratoire Ecologie; Systematique et Evolution; UMR8079 Orsay Cedex F-91405 France
- Eco-Anthropologie et Ethnobiologie; UMR 7206 CNRS; MNHN; Univ Paris Diderot; Sorbonne Paris Cité F-75231 Paris Cedex 5 France
| | - Tatiana Giraud
- Ecologie, Systématique et Evolution; UMR 8079 Université Paris Sud Laboratoire Ecologie; Systematique et Evolution; UMR8079 Orsay Cedex F-91405 France
| | - Frédéric Labbé
- Ecologie, Systématique et Evolution; UMR 8079 Université Paris Sud Laboratoire Ecologie; Systematique et Evolution; UMR8079 Orsay Cedex F-91405 France
| | - Daciana Papura
- INRA; UMR1065 Santé et Agroécologie du Vignoble; ISVV; F-33883 Villenave d'Ornon Cedex France
| | - Sylvie Richard-Cervera
- INRA; UMR1065 Santé et Agroécologie du Vignoble; ISVV; F-33883 Villenave d'Ornon Cedex France
| | - François Delmotte
- INRA; UMR1065 Santé et Agroécologie du Vignoble; ISVV; F-33883 Villenave d'Ornon Cedex France
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87
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Sequencing and annotation of the Ophiostoma ulmi genome. BMC Genomics 2013; 14:162. [PMID: 23496816 PMCID: PMC3618308 DOI: 10.1186/1471-2164-14-162] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 02/28/2013] [Indexed: 02/02/2023] Open
Abstract
Background The ascomycete fungus Ophiostoma ulmi was responsible for the initial pandemic of the massively destructive Dutch elm disease in Europe and North America in early 1910. Dutch elm disease has ravaged the elm tree population globally and is a major threat to the remaining elm population. O. ulmi is also associated with valuable biomaterials applications. It was recently discovered that proteins from O. ulmi can be used for efficient transformation of amylose in the production of bioplastics. Results We have sequenced the 31.5 Mb genome of O.ulmi using Illumina next generation sequencing. Applying both de novo and comparative genome annotation methods, we predict a total of 8639 gene models. The quality of the predicted genes was validated using a variety of data sources consisting of EST data, mRNA-seq data and orthologs from related fungal species. Sequence-based computational methods were used to identify candidate virulence-related genes. Metabolic pathways were reconstructed and highlight specific enzymes that may play a role in virulence. Conclusions This genome sequence will be a useful resource for further research aimed at understanding the molecular mechanisms of pathogenicity by O. ulmi. It will also facilitate the identification of enzymes necessary for industrial biotransformation applications.
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88
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McKinney L, Thomsen I, Kjær E, Bengtsson S, Nielsen L. Rapid invasion by an aggressive pathogenic fungus (Hymenoscyphus pseudoalbidus) replaces a native decomposer (Hymenoscyphus albidus): a case of local cryptic extinction? FUNGAL ECOL 2012. [DOI: 10.1016/j.funeco.2012.05.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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89
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Impacts of the emerald ash borer (Agrilus planipennis Fairmaire) induced ash (Fraxinus spp.) mortality on forest carbon cycling and successional dynamics in the eastern United States. Biol Invasions 2012. [DOI: 10.1007/s10530-012-0341-7] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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90
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Associations of Conifer-Infesting Bark Beetles and Fungi in Fennoscandia. INSECTS 2012; 3:200-27. [PMID: 26467956 PMCID: PMC4553624 DOI: 10.3390/insects3010200] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 01/10/2012] [Accepted: 01/17/2012] [Indexed: 11/17/2022]
Abstract
Bark beetles (Coleoptera, Scolytinae) have a widespread association with fungi, especially with ophiostomatoid fungi (Ascomycota) that cause blue staining of wood, and in some cases, serious tree diseases. In Fennoscandia, most studies of these fungi have focused on economically important bark beetle species and this is likely to have led to a biased view of the fungal biodiversity in the region. Recently, the associations between fungi and bark beetles in Fennoscandia have been shown to be more diverse than previously thought. Furthermore, they form complex and dynamic associations that are only now beginning to emerge. This review examines the current knowledge of the rather poorly known interactions between bark beetles, fungi and their conifer host trees in Fennoscandia. The diversity of ophiostomatoid species is discussed and the possible factors that influence the assemblages of fungal associates are considered for all species that are known to occur in the region. For many ophiostomatoid species found in Fennoscandia, little or nothing is known regarding their pathogenicity, particularly if they were to be transferred to new environments. We, therefore, draw attention to the possible threats of timber trade and climate change-induced invasions of new habitats by bark beetles and the fungi that can be moved along with them.
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91
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Filipe JAN, Cobb RC, Meentemeyer RK, Lee CA, Valachovic YS, Cook AR, Rizzo DM, Gilligan CA. Landscape epidemiology and control of pathogens with cryptic and long-distance dispersal: sudden oak death in northern Californian forests. PLoS Comput Biol 2012; 8:e1002328. [PMID: 22241973 PMCID: PMC3252276 DOI: 10.1371/journal.pcbi.1002328] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 11/11/2011] [Indexed: 11/19/2022] Open
Abstract
Exotic pathogens and pests threaten ecosystem service, biodiversity, and crop security globally. If an invasive agent can disperse asymptomatically over long distances, multiple spatial and temporal scales interplay, making identification of effective strategies to regulate, monitor, and control disease extremely difficult. The management of outbreaks is also challenged by limited data on the actual area infested and the dynamics of spatial spread, due to financial, technological, or social constraints. We examine principles of landscape epidemiology important in designing policy to prevent or slow invasion by such organisms, and use Phytophthora ramorum, the cause of sudden oak death, to illustrate how shortfalls in their understanding can render management applications inappropriate. This pathogen has invaded forests in coastal California, USA, and an isolated but fast-growing epidemic focus in northern California (Humboldt County) has the potential for extensive spread. The risk of spread is enhanced by the pathogen's generalist nature and survival. Additionally, the extent of cryptic infection is unknown due to limited surveying resources and access to private land. Here, we use an epidemiological model for transmission in heterogeneous landscapes and Bayesian Markov-chain-Monte-Carlo inference to estimate dispersal and life-cycle parameters of P. ramorum and forecast the distribution of infection and speed of the epidemic front in Humboldt County. We assess the viability of management options for containing the pathogen's northern spread and local impacts. Implementing a stand-alone host-free "barrier" had limited efficacy due to long-distance dispersal, but combining curative with preventive treatments ahead of the front reduced local damage and contained spread. While the large size of this focus makes effective control expensive, early synchronous treatment in newly-identified disease foci should be more cost-effective. We show how the successful management of forest ecosystems depends on estimating the spatial scales of invasion and treatment of pathogens and pests with cryptic long-distance dispersal.
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Affiliation(s)
- João A N Filipe
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom.
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92
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Tellenbach C, Grünig CR, Sieber TN. Negative effects on survival and performance of Norway spruce seedlings colonized by dark septate root endophytes are primarily isolate-dependent. Environ Microbiol 2011; 13:2508-17. [PMID: 21812887 DOI: 10.1111/j.1462-2920.2011.02523.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Root endophytes are common and genetically highly diverse suggesting important ecological roles. Yet, relative to above-ground endophytes, little is known about them. Dark septate endophytic fungi of the Phialocephala fortinii s.l.-Acephala applanata species complex (PAC) are ubiquitous root colonizers of conifers and Ericaceae, but their ecological function is largely unknown. Responses of Norway spruce seedlings of two seed provenances to inoculations with isolates of four PAC species were studied in vitro. In addition, isolates of Phialocephala subalpina from two populations within and one outside the natural range of Norway spruce were also included to study the effect of the geographic origin of P. subalpina on host response. The interaction of PAC with Norway spruce ranged from neutral to highly virulent and was primarily isolate-dependent. Variation in virulence was much higher within than among species, nonetheless only isolates of P. subalpina were highly virulent. Disease caused by P. subalpina genotypes from the native range of Norway spruce was more severe than that induced by genotypes from outside the natural distribution of Norway spruce. Virulence was not correlated with the phylogenetic relatedness of the isolates but was positively correlated with the extent of fungal colonization as measured by quantitative real-time PCR.
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Affiliation(s)
- Christoph Tellenbach
- ETH Zürich, Institute of Integrative Biology, Forest Pathology and Dendrology, Universitätstr. 16, CH-8092 Zürich, Switzerland.
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93
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Zipfel RD, de Beer ZW, Jacobs K, Wingfield BD, Wingfield MJ. Multi-gene phylogenies define Ceratocystiopsis and Grosmannia distinct from Ophiostoma. Stud Mycol 2011; 55:75-97. [PMID: 18490973 PMCID: PMC2104718 DOI: 10.3114/sim.55.1.75] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Ophiostoma species have diverse morphological features and are
found in a large variety of ecological niches. Many different classification
schemes have been applied to these fungi in the past based on teleomorph and
anamorph features. More recently, studies based on DNA sequence comparisions
have shown that Ophiostoma consists of different phylogenetic groups,
but the data have not been sufficient to define clear monophyletic lineages
represented by practical taxonomic units. We used DNA sequence data from
combined partial nuclear LSU and β-tubulin genes to consider the
phylogenetic relationships of 50 Ophiostoma species, representing all
the major morphological groups in the genus. Our data showed three
well-supported, monophyletic lineages in Ophiostoma. Species with
Leptographium anamorphs grouped together and to accommodate these
species the teleomorph-genus Grosmannia (type species G.
penicillata), including 27 species and 24 new combinations, is
re-instated. Another well-defined lineage includes species that are
cycloheximide-sensitive with short perithecial necks, falcate ascospores and
Hyalorhinocladiella anamorphs. For these species, the
teleomorph-genus Ceratocystiopsis (type species O. minuta),
including 11 species and three new combinations, is re-instated. A third group
of species with either Sporothrix or Pesotum anamorphs
includes species from various ecological niches such as Protea
infructescences in South Africa. This group also includes O.
piliferum, the type species of Ophiostoma, and these species are
retained in that genus. Ophiostoma is redefined to reflect the
changes resulting from new combinations in Grosmannia and
Ceratocystiopsis. Our data have revealed additional lineages in
Ophiostoma linked to morphological characters. However, these species
are retained in Ophiostoma until further data for a larger number of
species can be obtained to confirm monophyly of the apparent lineages.
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Affiliation(s)
- Renate D Zipfel
- Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0002, South Africa
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Endoh R, Suzuki M, Okada G, Takeuchi Y, Futai K. Fungus symbionts colonizing the galleries of the ambrosia beetle Platypus quercivorus. MICROBIAL ECOLOGY 2011; 62:106-120. [PMID: 21384214 DOI: 10.1007/s00248-011-9838-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Accepted: 02/21/2011] [Indexed: 05/30/2023]
Abstract
Isolations were made to determine the fungal symbionts colonizing Platypus quercivorus beetle galleries of dead or dying Quercus laurifolia, Castanopsis cuspidata, Quercus serrata, Quercus crispula, and Quercus robur. For these studies, logs from oak wilt-killed trees were collected from Kyoto Prefecture, Japan. Fungi were isolated from the: (1) entrances of beetle galleries, (2) vertical galleries, (3) lateral galleries, and (4) the larval cradle of P. quercivorus in each host tree. Among the fungus colonies which appeared on YM agar plates, 1,219 were isolated as the representative isolates for fungus species inhabiting in the galleries based on their cultural characteristics. The validity of the visual classification of the fungus colonies was checked and if necessary properly corrected using microsatellite-primed PCR fingerprints. The nucleotide sequence of the D1/D2 region of the large subunit nuclear rRNA gene detected 38 fungus species (104 strains) of which three species, i.e., Candida sp. 3, Candida kashinagacola (both yeasts), and the filamentous fungus Raffaelea quercivora were isolated from all the tree species. The two yeasts were most prevalent in the interior of galleries, regardless of host tree species, suggesting their close association with the beetle. A culture-independent method, terminal restriction fragment length polymorphism (T-RFLP) analysis was also used to characterize the fungus flora of beetle galleries. T-RFLP patterns showed that yeast species belonging to the genus Ambrosiozyma frequently occurred on the gallery walls along with the two Candida species. Ours is the first report showing the specific fungi inhabiting the galleries of a platypodid ambrosia beetle.
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Affiliation(s)
- Rikiya Endoh
- Laboratory of Environmental Mycoscience, Division of Environmental Science and Technology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan.
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Oghiakhe S, Holliday NJ. Evaluation of insecticides for control of overwintering Hylurgopinus rufipes (Coleoptera: Curculionidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2011; 104:889-894. [PMID: 21735908 DOI: 10.1603/ec10336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A bark disk bioassay was used to assess the effectiveness of different insecticides for control of overwintering adult native elm bark beetles, Hylurgopinus rufipes (Eichoff) (Coleoptera: Curculionidae). Insecticides were applied to the base of the trunks of living American elm trees, Ulmus americana L., and bark disk samples were removed at intervals with a hole saw. Adult H. rufipes were exposed in bioassay chambers for which the bark disks formed the floor of the chamber. In September 2005, chlorpyrifos, permethrin, and a water control were applied to trees in five replicated blocks, and bark disk samples were taken at intervals over the following 725 d. In September 2006, chlorpyrifos, permethrin, carbaryl, bifenthrin, and a water control were applied to trees in six replicated blocks, and disk samples were removed at intervals up to 1,163 d after application. In both experiments, beetle mortality was 100% on chlorpyrifos-treated disks removed up to 725 d after treatment and, in the 2006 trial, declined thereafter. The pattern of mortality in the bifenthrin treatment did not differ significantly from that in the chlorpyrifos treatment in the 2006 experiment. Average corrected mortality on disks treated with permethrin or carbaryl declined below 100% by 11 d after application. On disks removed in the May following treatment, 248 d after application, average corrected mortality was 42-44% on permethrin-treated disks and 26% on carbaryl-treated disks.
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Affiliation(s)
- S Oghiakhe
- Department of Entomology, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
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96
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Whittemore AT, Olsen RT. Ulmus americana (Ulmaceae) is a polyploid complex. AMERICAN JOURNAL OF BOTANY 2011; 98:754-60. [PMID: 21613171 DOI: 10.3732/ajb.1000372] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
PREMISE OF THE STUDY Exotic diseases are threatening many North American tree species, and management of diseases requires understanding the biology of the host as well as the pathogen. Ulmus americana is a widespread dominant tree of eastern North America that has been widely planted as an ornamental and shade tree. Populations of the species have suffered heavy mortality from Dutch elm disease, caused by an introduced fungus. Ulmus americana is generally reported to be tetraploid, but the discovery of triploid trees in cultivation suggested that lower ploidy levels may exist in the wild, so the species was surveyed for nuclear DNA content. METHODS Ploidy level was estimated by flow cytometry for 81 individuals from wild populations of U. americana from throughout the range of the species and for four cultivated trees of interest. KEY RESULTS Most specimens were tetraploid, as previously reported for the species, but 21% of the wild trees sampled were diploid, a ploidy level not previously confirmed for the species. Tetraploids are found throughout the range of the species. Diploids are most common on the Atlantic coastal plain, Cumberland Plateau, and in southern Ohio, but isolated diploids were also found in central Texas, Oklahoma, and eastern Missouri. Diploids and tetraploids grew in proximity in several areas, but no wild triploids were found in the course of this survey. CONCLUSIONS The species is genetically heterogeneous, but further research is needed to understand the origin and relations of the different ploidy levels. Understanding the ploidy situation in U. americana will be important in the search for further genotypes that are resistant to Dutch elm disease.
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Affiliation(s)
- Alan T Whittemore
- U.S. National Arboretum, 3501 New York Ave NE, Washington, DC 20002-1958, USA.
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98
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Grobbelaar JW, de Beer ZW, Bloomer P, Wingfield MJ, Wingfield BD. Ophiostoma tsotsi sp. nov., a wound-infesting fungus of hardwood trees in Africa. Mycopathologia 2010; 169:413-23. [PMID: 20054655 DOI: 10.1007/s11046-009-9267-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Accepted: 12/04/2009] [Indexed: 11/29/2022]
Abstract
Polymorphic sequence-characterised marker assays from a recent diversity study on the Ascomycete fungus Ophiostoma quercus reported that some isolates from Africa were genetically distinct from O. quercus. In the present study, these African isolates were compared with authentic O. quercus isolates by evaluating morphological characters, growth in culture, mating compatibility and DNA sequence data. The isolates from Africa were morphologically similar to O. quercus, presenting Pesotum and Sporothrix synanamorphs in culture. Phylogenetic analyses of the ribosomal internal transcribed spacer regions 1 and 2, beta-tubulin and translation elongation factor 1-alpha gene regions confirmed that the African group represents a distinct species within the hardwood lineage of the O. piceae complex, closely related to O. ulmi and O. himal-ulmi. Mating studies between O. quercus and the African isolates showed that isolates mated predominantly with those of their own group, although there were rare cases of fertile crosses between the groups. Isolates residing in the African lineage are described here as a new species, O. tsotsi sp. nov.
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Affiliation(s)
- Joha W Grobbelaar
- Department of Genetics, University of Pretoria, Pretoria 0002, South Africa
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Do mites phoretic on elm bark beetles contribute to the transmission of Dutch elm disease? Naturwissenschaften 2009; 97:219-27. [DOI: 10.1007/s00114-009-0630-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 10/01/2009] [Accepted: 11/19/2009] [Indexed: 11/26/2022]
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100
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Ligninolytic Fungal Laccases and Their Biotechnological Applications. Appl Biochem Biotechnol 2009; 160:1760-88. [DOI: 10.1007/s12010-009-8676-y] [Citation(s) in RCA: 192] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Accepted: 05/18/2009] [Indexed: 10/20/2022]
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