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Santos-Pascual R, Campoy I, Sanz Mata D, Martínez MJ, Prieto A, Barriuso J. Deciphering the molecular components of the quorum sensing system in the fungus Ophiostoma piceae. Microbiol Spectr 2023; 11:e0029023. [PMID: 37796004 PMCID: PMC10715110 DOI: 10.1128/spectrum.00290-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 07/19/2023] [Indexed: 10/06/2023] Open
Abstract
IMPORTANCE This manuscript presents a comprehensive study on the molecular mechanisms triggered by the quorum sensing (QS) molecule farnesol in the biotechnologically relevant fungus Ophiostoma piceae. We present for the first time, using a multiomics approach, an in-depth analysis of the QS response in a saprotroph fungus, detailing the molecular components involved in the response and their possible mechanisms of action. We think that these results are particularly relevant in the knowledge of the functioning of the QS in eukaryotes, as well as for the exploitation of these mechanisms.
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Affiliation(s)
- Rodrigo Santos-Pascual
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CIB-CSIC), Madrid, Spain
| | - Iván Campoy
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CIB-CSIC), Madrid, Spain
| | - David Sanz Mata
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CIB-CSIC), Madrid, Spain
| | - María Jesús Martínez
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CIB-CSIC), Madrid, Spain
| | - Alicia Prieto
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CIB-CSIC), Madrid, Spain
| | - Jorge Barriuso
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CIB-CSIC), Madrid, Spain
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Kännaste A, Jürisoo L, Runno-Paurson E, Kask K, Talts E, Pärlist P, Drenkhan R, Niinemets Ü. Impacts of Dutch elm disease-causing fungi on foliage photosynthetic characteristics and volatiles in Ulmus species with different pathogen resistance. Tree Physiol 2023; 43:57-74. [PMID: 36106799 DOI: 10.1093/treephys/tpac108] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 09/01/2022] [Indexed: 06/15/2023]
Abstract
Global warming affects the abiotic and biotic growth environment of plants, including the spread of fungal diseases such as Dutch elm disease (DED). Dutch elm disease-resistance of different Ulmus species varies, but how this is reflected in leaf-level physiological pathogen responses has not been investigated. We studied the impacts of mechanical injury alone and mechanical injury plus inoculation with the DED-causing pathogens Ophiostoma novo-ulmi subsp. novo-ulmi and O. novo-ulmi subsp. americana on Ulmus glabra, a more vulnerable species, and U. laevis, a more resistant species. Plant stress responses were evaluated for 12 days after stress application by monitoring leaf net CO2 assimilation rate (A), stomatal conductance (gs), ratio of ambient to intercellular CO2 concentration (Ca/Ci) and intrinsic water-use efficiency (A/gs), and by measuring biogenic volatile (VOC) release by plant leaves. In U. glabra and U. laevis, A was not affected by time, stressors or their interaction. Only in U. glabra, gs and Ca/Ci decreased in time, yet recovered by the end of the experiment. Although the emission compositions were affected in both species, the stress treatments enhanced VOC emission rates only in U. laevis. In this species, mechanical injury especially when combined with the pathogens increased the emission of lipoxygenase pathway volatiles and dimethylallyl diphosphate and geranyl diphosphate pathway volatiles. In conclusion, the more resistant species U. laevis had a more stable photosynthesis, but stronger pathogen-elicited volatile response, especially after inoculation by O. novo-ulmi subsp. novo-ulmi. Thus, stronger activation of defenses might underlay higher DED-resistance in this species.
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Affiliation(s)
- Astrid Kännaste
- Chair of Crop Science and Plant Biology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51006, Estonia
| | - Liina Jürisoo
- Chair of Silviculture and Forest Ecology, Institute of Forestry and Engineering, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51006, Estonia
| | - Eve Runno-Paurson
- Chair of Crop Science and Plant Biology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51006, Estonia
| | - Kaia Kask
- Chair of Crop Science and Plant Biology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51006, Estonia
| | - Eero Talts
- Chair of Crop Science and Plant Biology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51006, Estonia
| | - Piret Pärlist
- Chair of Crop Science and Plant Biology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51006, Estonia
| | - Rein Drenkhan
- Chair of Silviculture and Forest Ecology, Institute of Forestry and Engineering, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51006, Estonia
| | - Ülo Niinemets
- Chair of Crop Science and Plant Biology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51006, Estonia
- Estonian Academy of Sciences, Kohtu 6, Tallinn 10130, Estonia
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Jankowiak R, Bilański P, Strzałka B, Linnakoski R, Bosak A, Hausner G. Four new Ophiostoma species associated with conifer- and hardwood-infesting bark and ambrosia beetles from the Czech Republic and Poland. Antonie Van Leeuwenhoek 2019; 112:1501-1521. [PMID: 31140027 PMCID: PMC6748885 DOI: 10.1007/s10482-019-01277-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 05/14/2019] [Indexed: 12/24/2022]
Abstract
Fungi under the order Ophiostomatales (Ascomycota) are known to associate with various species of bark beetles (Coleoptera: Curculionidae: Scolytinae). In addition this group of fungi contains many taxa that can impart blue-stain on sapwood and some are important tree pathogens. A recent survey that focussed on the diversity of the Ophiostomatales in the forest ecosystems of the Czech Republic and Poland uncovered four putative new species. Phylogenetic analyses of four gene regions (ITS1-5.8S-ITS2 region, ß-tubulin, calmodulin, and translation elongation factor 1-α) indicated that these four species are members of the genus Ophiostoma. All four newly described species can be distinguished from each other and from closely related species based on DNA sequence comparisons, morphological characters, growth rates, and their insect associations. Based on this study four new taxa can be circumscribed and the following names are provided: Ophiostoma pityokteinis sp. nov., Ophiostoma rufum sp. nov., Ophiostoma solheimii sp. nov., and Ophiostoma taphrorychi sp. nov. O. rufum sp. nov. is a member of the Ophiostoma piceae species complex, while O. pityokteinis sp. nov. resides in a discrete lineage within Ophiostoma s. stricto. O. taphrorychi sp. nov. together with O. distortum formed a well-supported clade in Ophiostoma s. stricto close to O. pityokteinis sp. nov. O. solheimii sp. nov. groups within a currently undefined lineage A, which also includes Ophiostoma grandicarpum and Ophiostoma microsporum. This study highlights the need for more intensive surveys that should include additional countries of Central Europe, insect vectors and host tree species in order to elucidate Ophiostoma species diversity in this region.
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Affiliation(s)
- Robert Jankowiak
- Department of Forest Pathology, Mycology and Tree Physiology, Institute of Forest Ecosystem Protection, University of Agriculture in Krakow, Al. 29 Listopada 46, 31-425, Kraków, Poland.
| | - Piotr Bilański
- Department of Forest Protection, Entomology and Forest Climatology, Institute of Forest Ecosystem Protection, University of Agriculture in Krakow, Al. 29 Listopada 46, 31-425, Kraków, Poland
| | - Beata Strzałka
- Department of Forest Pathology, Mycology and Tree Physiology, Institute of Forest Ecosystem Protection, University of Agriculture in Krakow, Al. 29 Listopada 46, 31-425, Kraków, Poland
| | - Riikka Linnakoski
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790, Helsinki, Finland
| | - Agnieszka Bosak
- Department of Forest Pathology, Mycology and Tree Physiology, Institute of Forest Ecosystem Protection, University of Agriculture in Krakow, Al. 29 Listopada 46, 31-425, Kraków, Poland
| | - Georg Hausner
- Department of Microbiology, Buller Building 213, University of Manitoba, Winnipeg, R3T 2N2, Canada
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Pepori AL, Bettini PP, Comparini C, Sarrocco S, Bonini A, Frascella A, Ghelardini L, Scala A, Vannacci G, Santini A. Geosmithia-Ophiostoma: a New Fungus-Fungus Association. Microb Ecol 2018; 75:632-646. [PMID: 28875260 PMCID: PMC5856884 DOI: 10.1007/s00248-017-1062-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/22/2017] [Indexed: 06/07/2023]
Abstract
In Europe as in North America, elms are devastated by Dutch elm disease (DED), caused by the alien ascomycete Ophiostoma novo-ulmi. Pathogen dispersal and transmission are ensured by local species of bark beetles, which established a novel association with the fungus. Elm bark beetles also transport the Geosmithia fungi genus that is found in scolytids' galleries colonized by O. novo-ulmi. Widespread horizontal gene transfer between O. novo-ulmi and Geosmithia was recently observed. In order to define the relation between these two fungi in the DED pathosystem, O. novo-ulmi and Geosmithia species from elm, including a GFP-tagged strain, were grown in dual culture and mycelial interactions were observed by light and fluorescence microscopy. Growth and sporulation of O. novo-ulmi in the absence or presence of Geosmithia were compared. The impact of Geosmithia on DED severity was tested in vivo by co-inoculating Geosmithia and O. novo-ulmi in elms. A close and stable relation was observed between the two fungi, which may be classified as mycoparasitism by Geosmithia on O. novo-ulmi. These results prove the existence of a new component in the complex of organisms involved in DED, which might be capable of reducing the disease impact.
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Affiliation(s)
- Alessia L Pepori
- Institute for Sustainable Plant Protection (IPSP-CNR), via Madonna del Piano 10, 50019, Sesto Fiorentino, FI, Italy
| | - Priscilla P Bettini
- Department of Biology, University of Florence, via Madonna del Piano 6, 50019, Sesto Fiorentino, FI, Italy
| | - Cecilia Comparini
- Institute for Sustainable Plant Protection (IPSP-CNR), via Madonna del Piano 10, 50019, Sesto Fiorentino, FI, Italy
- Department of Agri-Food Production and Environmental Science (DiSPAA), University of Florence, Piazzale delle Cascine 28, 50144, Florence, Italy
| | - Sabrina Sarrocco
- Department of Agriculture, Food and Environment (DAFE), University of Pisa, via del Borghetto 80, 56124, Pisa, Italy
| | - Anna Bonini
- Department of Agri-Food Production and Environmental Science (DiSPAA), University of Florence, Piazzale delle Cascine 28, 50144, Florence, Italy
| | - Arcangela Frascella
- Department of Biology, University of Florence, via Madonna del Piano 6, 50019, Sesto Fiorentino, FI, Italy
| | - Luisa Ghelardini
- Institute for Sustainable Plant Protection (IPSP-CNR), via Madonna del Piano 10, 50019, Sesto Fiorentino, FI, Italy
- Department of Agri-Food Production and Environmental Science (DiSPAA), University of Florence, Piazzale delle Cascine 28, 50144, Florence, Italy
| | - Aniello Scala
- Department of Agri-Food Production and Environmental Science (DiSPAA), University of Florence, Piazzale delle Cascine 28, 50144, Florence, Italy
| | - Giovanni Vannacci
- Department of Agriculture, Food and Environment (DAFE), University of Pisa, via del Borghetto 80, 56124, Pisa, Italy
| | - Alberto Santini
- Institute for Sustainable Plant Protection (IPSP-CNR), via Madonna del Piano 10, 50019, Sesto Fiorentino, FI, Italy.
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Pita P, Rodríguez-Calcerrada J, Medel D, Gil L. Further insights into the components of resistance to Ophiostoma novo-ulmi in Ulmus minor: hydraulic conductance, stomatal sensitivity and bark dehydration. Tree Physiol 2018; 38:252-262. [PMID: 29040781 DOI: 10.1093/treephys/tpx123] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 09/14/2017] [Indexed: 06/07/2023]
Abstract
Dutch elm disease (DED) is a vascular disease that has killed over 1 billion elm trees. The pathogen spreads throughout the xylem network triggering vessel blockage, which results in water stress, tissue dehydration and extensive leaf wilting in susceptible genotypes. We investigated the differences between four Ulmus minor Mill. clones of contrasting susceptibility to Ophiostoma novo-ulmi Brasier regarding morphological, anatomical and physiological traits affecting water transport, in order to gain a better understanding of the mechanisms underlying DED susceptibility. We analyzed the differential response to water shortage and increased air vapor pressure deficit (VPD) to investigate whether resistance to water stress might be related to DED tolerance. Sixteen plants per clone, aged 2 years, were grown inside a greenhouse under differential watering. Stomatal conductance was measured under ambient and increased VPD. Growth, bark water content and stem hydraulic and anatomical parameters were measured 22 days after starting differential watering. Vessel lumen area, lumen fraction and hydraulic conductance were highest in susceptible clones. Stomatal conductance was lowest under low VPD and decreased faster under increased VPD in resistant clones. We found a negative relationship between the decrease in stomatal conductance at increased VPD and specific hydraulic conductance, revealing a narrower hydraulic margin for sustaining transpiration in resistant clones. The effect of water shortage was greater on radial stem growth than on leaf area, which could be explained through an extensive use of capacitance water to buffer xylem water potential. Water shortage reduced stomatal conductance and vessel lumen area. Bark water content under conditions of water shortage only decreased in susceptible clones. Higher hydraulic constraints to sap flow in resistant clones may determine higher stomatal sensitivity to VPD and so contribute to DED resistance by limiting pathogen expansion and reducing water loss and metabolic impairment in cells involved in fighting against infection.
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Affiliation(s)
- Pilar Pita
- ETSI Montes, Forestal y del Medio Natural, Dep. Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Jesús Rodríguez-Calcerrada
- ETSI Montes, Forestal y del Medio Natural, Dep. Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - David Medel
- ETSI Montes, Forestal y del Medio Natural, Dep. Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Luis Gil
- ETSI Montes, Forestal y del Medio Natural, Dep. Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
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Perdiguero P, Sobrino-Plata J, Venturas M, Martín JA, Gil L, Collada C. Gene expression trade-offs between defence and growth in English elm induced by Ophiostoma novo-ulmi. Plant Cell Environ 2018; 41:198-214. [PMID: 29034465 DOI: 10.1111/pce.13085] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 09/12/2017] [Accepted: 09/21/2017] [Indexed: 06/07/2023]
Abstract
Wilt diseases caused by vascular pathogens include some of the most damaging stresses affecting trees. Dutch elm disease (DED), caused by the fungus Ophiostoma novo-ulmi, destroyed most of North American and European elm populations in the 20th century. The highly susceptible English elm, also known as Atinian clone, suffered the highest mortality rates during the last pandemic event, probably due to its lack of genetic diversity. To study the DED pathosystem, we inoculated English elm ramets with O. novo-ulmi and evaluated xylem anatomy, molecular response, and disease symptoms. The high DED susceptibility of the clone was linked to xylem structure. The transcript levels changed significantly for 1,696 genes during O. novo-ulmi invasion. Genes covering different steps of the plant immune system were identified, many of which showed homology with Arabidopsis thaliana genes involved in systemic acquired resistance. Induction of several pathogenesis-related proteins and repression of fasciclin-like arabinogalactan proteins and other cell wall biosynthesis pathways evidence unbalanced costs between growth and defence mechanisms far from the inoculation point. This study sheds light on elm molecular defence mechanisms against DED.
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Affiliation(s)
- Pedro Perdiguero
- GENFOR, Grupo de Investigación en Genética, Fisiología e Historia Forestal, Universidad Politécnica de Madrid (UPM), 28040, Madrid, Spain
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - Juan Sobrino-Plata
- GENFOR, Grupo de Investigación en Genética, Fisiología e Historia Forestal, Universidad Politécnica de Madrid (UPM), 28040, Madrid, Spain
| | - Martin Venturas
- GENFOR, Grupo de Investigación en Genética, Fisiología e Historia Forestal, Universidad Politécnica de Madrid (UPM), 28040, Madrid, Spain
- Biology Department, University of Utah, Salt Lake City, UT, 84112, USA
| | - Juan Antonio Martín
- GENFOR, Grupo de Investigación en Genética, Fisiología e Historia Forestal, Universidad Politécnica de Madrid (UPM), 28040, Madrid, Spain
| | - Luis Gil
- GENFOR, Grupo de Investigación en Genética, Fisiología e Historia Forestal, Universidad Politécnica de Madrid (UPM), 28040, Madrid, Spain
| | - Carmen Collada
- GENFOR, Grupo de Investigación en Genética, Fisiología e Historia Forestal, Universidad Politécnica de Madrid (UPM), 28040, Madrid, Spain
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Kandasamy D, Gershenzon J, Hammerbacher A. Volatile Organic Compounds Emitted by Fungal Associates of Conifer Bark Beetles and their Potential in Bark Beetle Control. J Chem Ecol 2016; 42:952-969. [PMID: 27687998 PMCID: PMC5101256 DOI: 10.1007/s10886-016-0768-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 08/14/2016] [Accepted: 09/07/2016] [Indexed: 11/06/2022]
Abstract
Conifer bark beetles attack and kill mature spruce and pine trees, especially during hot and dry conditions. These beetles are closely associated with ophiostomatoid fungi of the Ascomycetes, including the genera Ophiostoma, Grosmannia, and Endoconidiophora, which enhance beetle success by improving nutrition and modifying their substrate, but also have negative impacts on beetles by attracting predators and parasites. A survey of the literature and our own data revealed that ophiostomatoid fungi emit a variety of volatile organic compounds under laboratory conditions including fusel alcohols, terpenoids, aromatic compounds, and aliphatic alcohols. Many of these compounds already have been shown to elicit behavioral responses from bark beetles, functioning as attractants or repellents, often as synergists to compounds currently used in bark beetle control. Thus, these compounds could serve as valuable new agents for bark beetle management. However, bark beetle associations with fungi are very complex. Beetle behavior varies with the species of fungus, the stage of the beetle life cycle, the host tree quality, and probably with changes in the emission rate of fungal volatiles. Additional research on bark beetles and their symbiotic associates is necessary before the basic significance of ophiostomatoid fungal volatiles can be understood and their applied potential realized.
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Affiliation(s)
- Dineshkumar Kandasamy
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745, Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745, Jena, Germany.
| | - Almuth Hammerbacher
- Department of Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa
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Plichta R, Urban J, Gebauer R, Dvořák M, Ďurkovič J. Long-term impact of Ophiostoma novo-ulmi on leaf traits and transpiration of branches in the Dutch elm hybrid 'Dodoens'. Tree Physiol 2016; 36:335-44. [PMID: 26843210 PMCID: PMC4885949 DOI: 10.1093/treephys/tpv144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 12/21/2015] [Indexed: 05/07/2023]
Abstract
To better understand the long-term impact of Ophiostoma novo-ulmi Brasier on leaf physiology in 'Dodoens', a Dutch elm disease-tolerant hybrid, measurements of leaf area, leaf dry mass, petiole anatomy, petiole hydraulic conductivity, leaf and branch water potential, and branch sap flow were performed 3 years following an initial artificial inoculation. Although fungal hyphae were detected in fully expanded leaves, neither anatomical nor morphological traits were affected, indicating that there was no impact from the fungal hyphae on the leaves during leaf expansion. In contrast, however, infected trees showed both a lower transpiration rate of branches and a lower sap flow density. The long-term persistence of fungal hyphae inside vessels decreased the xylem hydraulic conductivity, but stomatal regulation of transpiration appeared to be unaffected as the leaf water potential in both infected and non-infected trees was similarly driven by the transpirational demands. Regardless of the fungal infection, leaves with a higher leaf mass per area ratio tended to have a higher leaf area-specific conductivity. Smaller leaves had an increased number of conduits with smaller diameters and thicker cell walls. Such a pattern could increase tolerance towards hydraulic dysfunction. Measurements of water potential and theoretical xylem conductivity revealed that petiole anatomy could predict the maximal transpiration rate. Three years following fungal inoculation, phenotypic expressions for the majority of the examined traits revealed a constitutive nature for their possible role in Dutch elm disease tolerance of 'Dodoens' trees.
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Affiliation(s)
- Roman Plichta
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Josef Urban
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Roman Gebauer
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Miloň Dvořák
- Department of Forest Protection and Wildlife Management, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Jaroslav Ďurkovič
- Department of Phytology, Technical University in Zvolen, T. G. Masaryka 24, 960 53 Zvolen, Slovak Republic
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Durkovič J, Kačík F, Olčák D, Kučerová V, Krajňáková J. Host responses and metabolic profiles of wood components in Dutch elm hybrids with a contrasting tolerance to Dutch elm disease. Ann Bot 2014; 114:47-59. [PMID: 24854167 PMCID: PMC4071097 DOI: 10.1093/aob/mcu076] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 03/24/2014] [Indexed: 05/23/2023]
Abstract
BACKGROUND AND AIMS Changes occurring in the macromolecular traits of cell wall components in elm wood following attack by Ophiostoma novo-ulmi, the causative agent of Dutch elm disease (DED), are poorly understood. The purpose of this study was to compare host responses and the metabolic profiles of wood components for two Dutch elm (Ulmus) hybrids, 'Groeneveld' (a susceptible clone) and 'Dodoens' (a tolerant clone), that have contrasting survival strategies upon infection with the current prevalent strain of DED. METHODS Ten-year-old plants of the hybrid elms were inoculated with O. novo-ulmi ssp. americana × novo-ulmi. Measurements were made of the content of main cell wall components and extractives, lignin monomer composition, macromolecular traits of cellulose and neutral saccharide composition. KEY RESULTS Upon infection, medium molecular weight macromolecules of cellulose were degraded in both the susceptible and tolerant elm hybrids, resulting in the occurrence of secondary cell wall ruptures and cracks in the vessels, but rarely in the fibres. The (13)C nuclear magnetic resonance spectra revealed that loss of crystalline and non-crystalline cellulose regions occurred in parallel. The rate of cellulose degradation was influenced by the syringyl:guaiacyl ratio in lignin. Both hybrids commonly responded to the medium molecular weight cellulose degradation with the biosynthesis of high molecular weight macromolecules of cellulose, resulting in a significant increase in values for the degree of polymerization and polydispersity. Other responses of the hybrids included an increase in lignin content, a decrease in relative proportions of d-glucose, and an increase in proportions of d-xylose. Differential responses between the hybrids were found in the syringyl:guaiacyl ratio in lignin. CONCLUSIONS In susceptible 'Groeneveld' plants, syringyl-rich lignin provided a far greater degree of protection from cellulose degradation than in 'Dodoens', but only guaiacyl-rich lignin in 'Dodoens' plants was involved in successful defence against the fungus. This finding was confirmed by the associations of vanillin and vanillic acid with the DED-tolerant 'Dodoens' plants in a multivariate analysis of wood traits.
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Affiliation(s)
- Jaroslav Durkovič
- Department of Phytology, Technical University, 96053 Zvolen, Slovakia
| | - František Kačík
- Department of Chemistry and Chemical Technologies, Technical University, 96053 Zvolen, Slovakia
| | - Dušan Olčák
- Department of Physics, Technical University of Košice, 04200 Košice, Slovakia
| | - Veronika Kučerová
- Department of Forest Protection and Game Management, Technical University, 96053 Zvolen, Slovakia
| | - Jana Krajňáková
- Department of Agricultural and Environmental Science, University of Udine, 33100 Udine, Italy Department of Biology, University of Oulu, 90014 Oulu, Finland
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Durkovic J, Canová I, Lagana R, Kucerová V, Moravcík M, Priwitzer T, Urban J, Dvorák M, Krajnáková J. Leaf trait dissimilarities between Dutch elm hybrids with a contrasting tolerance to Dutch elm disease. Ann Bot 2013; 111:215-27. [PMID: 23264236 PMCID: PMC3555532 DOI: 10.1093/aob/mcs274] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 11/13/2012] [Indexed: 05/15/2023]
Abstract
BACKGROUND AND AIMS Previous studies have shown that Ophiostoma novo-ulmi, the causative agent of Dutch elm disease (DED), is able to colonize remote areas in infected plants of Ulmus such as the leaf midrib and secondary veins. The objective of this study was to compare the performances in leaf traits between two Dutch elm hybrids 'Groeneveld' and 'Dodoens' which possess a contrasting tolerance to DED. Trait linkages were also tested with leaf mass per area (LMA) and with the reduced Young's modulus of elasticity (MOE) as a result of structural, developmental or functional linkages. METHODS Measurements and comparisons were made of leaf growth traits, primary xylem density components, gas exchange variables and chlorophyll a fluorescence yields between mature plants of 'Groeneveld' and 'Dodoens' grown under field conditions. A recently developed atomic force microscopy technique, PeakForce quantitative nanomechanical mapping, was used to reveal nanomechanical properties of the cell walls of tracheary elements such as MOE, adhesion and dissipation. KEY RESULTS 'Dodoens' had significantly higher values for LMA, leaf tissue thickness variables, tracheary element lumen area (A), relative hydraulic conductivity (RC), gas exchange variables and chlorophyll a fluorescence yields. 'Groeneveld' had stiffer cell walls of tracheary elements, and higher values for water-use efficiency and leaf water potential. Leaves with a large carbon and nutrient investment in LMA tended to have a greater leaf thickness and a higher net photosynthetic rate, but LMA was independent of RC. Significant linkages were also found between the MOE and some vascular traits such as RC, A and the number of tracheary elements per unit area. CONCLUSIONS Strong dissimilarities in leaf trait performances were observed between the examined Dutch elm hybrids. Both hybrids were clearly separated from each other in the multivariate leaf trait space. Leaf growth, vascular and gas exchange traits in the infected plants of 'Dodoens' were unaffected by the DED fungus. 'Dodoens' proved to be a valuable elm germplasm for further breeding strategies.
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Villari C, Battisti A, Chakraborty S, Michelozzi M, Bonello P, Faccoli M. Nutritional and pathogenic fungi associated with the pine engraver beetle trigger comparable defenses in Scots pine. Tree Physiol 2012; 32:867-879. [PMID: 22718525 DOI: 10.1093/treephys/tps056] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Conifer bark beetles are often associated with fungal complexes whose components have different ecological roles. Some associated species are nutritionally obligate fungi, serving as nourishment to the larvae, whereas others are pathogenic blue-stain fungi known to be involved in the interaction with host defenses. In this study we characterized the local and systemic defense responses of Scots pine (Pinus sylvestris L.) against Ophiostoma brunneo-ciliatum Math. (a blue-stain pathogen) and Hyalorhinocladiella macrospora (Franke-Grosm.) Harr. (a nutritional fungus). These fungi are the principal associates of the pine engraver beetle, Ips acuminatus (Gyll.). Host responses were studied following inoculation with the fungi, singly and as a fungal complex, and by identifying and quantifying terpenoids, phenolic compounds and lignin. Although the length of the necrotic lesions differed between control (wound) and fungal treatments, only two compounds (pinosylvin monomethyl ether and (+)-α-pinene) were significantly affected by the presence of the fungi, indicating that Scots pine has a generic, rather than specific, induced response. The fact that both nutritional and blue-stain fungi triggered comparable induced defense responses suggests that even a non-pathogenic fungus may participate in exhausting host plant defenses, indirectly assisting in the beetle establishment process. Our findings contribute to the further development of current theory on the role of associated fungal complexes in bark beetle ecology.
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Affiliation(s)
- Caterina Villari
- Università degli Studi di Padova, DAFNAE - Entomologia, Agripolis, Legnaro PD 35020, Italy.
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Roets F, Crous PW, Wingfield MJ, Dreyer LL. Mite-mediated hyperphoretic dispersal of Ophiostoma spp. from the infructescences of South African Protea spp. Environ Entomol 2009; 38:143-152. [PMID: 19791608 DOI: 10.1603/022.038.0118] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Ophiostomatoid fungi are well known as economically important pathogens and agents of timber degradation. A unique assemblage of these arthropod-associated organisms including species of Gondwanamyces G. J. Marais and M. J. Wingf., and Ophiostoma Syd. and P. Syd. occur in the floral heads (infructescences) of Protea L. species in South Africa. It has recently been discovered that Ophiostoma found in Protea flower-heads are vectored by mites (Acarina) including species of: Tarsonemus Canestrini and Fonzago, Proctolaelaps Berlese, and Trichouropoda Berlese. It is, however, not known how the mites carry the fungi between host plants. In this study, we consider two possible modes of mite dispersal. These include self-dispersal between infructescences and dispersal through insect vectors. Results showed that, as infructescences desiccate, mites self-disperse to fresh moist infructescences. Long-range dispersal is achieved through a phoretic association with three beetle species: Genuchus hottentottus (F.), Trichostetha fascicularis L., and T. capensis L. The long-range, hyperphoretic dispersal of O. splendens G. J. Marais and M. J. Wingf. and O. phasma Roets et al. seemed effective, because their hosts were colonized during the first flowering season 3-4 yr after fire.
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Affiliation(s)
- F Roets
- Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa.
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