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Towards Understanding the Function of Aegerolysins. Toxins (Basel) 2022; 14:toxins14090629. [PMID: 36136567 PMCID: PMC9505663 DOI: 10.3390/toxins14090629] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/04/2022] [Accepted: 09/09/2022] [Indexed: 11/17/2022] Open
Abstract
Aegerolysins are remarkable proteins. They are distributed over the tree of life, being relatively widespread in bacteria and fungi, but also present in some insects, plants, protozoa, and viruses. Despite their abundance in cells of certain developmental stages and their presence in secretomes, only a few aegerolysins have been studied in detail. Their function, in particular, is intriguing. Here, we summarize previously published findings on the distribution, molecular interactions, and function of these versatile aegerolysins. They have very diverse protein sequences but a common fold. The machine learning approach of the AlphaFold2 algorithm, which incorporates physical and biological knowledge of protein structures and multisequence alignments, provides us new insights into the aegerolysins and their pore-forming partners, complemented by additional genomic support. We hypothesize that aegerolysins are involved in the mechanisms of competitive exclusion in the niche.
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Vicente CSL, Soares M, Faria JMS, Espada M, Mota M, Nóbrega F, Ramos AP, Inácio ML. Fungal Communities of the Pine Wilt Disease Complex: Studying the Interaction of Ophiostomatales With Bursaphelenchus xylophilus. FRONTIERS IN PLANT SCIENCE 2022; 13:908308. [PMID: 35812912 PMCID: PMC9257700 DOI: 10.3389/fpls.2022.908308] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 05/02/2022] [Indexed: 06/15/2023]
Abstract
Considered one of the most devastating plant-parasitic nematodes worldwide, Bursaphelenchus xylophilus (commonly known as pinewood nematode, PWN) is the causal agent of the pine wilt disease in the Eurasian coniferous forests. This migratory parasitic nematode is carried by an insect vector (Monochamus spp.) into the host tree (Pinus species), where it can feed on parenchymal cells and reproduce massively, resulting in the tree wilting. In declining trees, PWN populations are strongly dependent on fungal communities colonizing the host (predominantly ophiostomatoid fungi known to cause sapwood blue-staining, the blue-stain fungi), which not only influence their development and life cycle but also the number of individuals carried by the insect vector into a new host. Our main aim is to understand if PWN-associated mycobiota plays a key role in the development of PWD, in interaction with the PWN and the insect vector, and to what extent it can be targeted to disrupt the disease cycle. For this purpose, we characterized the fungal communities of Pinus pinaster trees infected and non-infected with PWN in three collection sites in Continental Portugal with different PWD temporal incidences. Our results showed that non-infected P. pinaster mycoflora is more diverse (in terms of abundance and fungal richness) than PWN-infected pine trees in the most recent PWD foci, as opposed to the fungal communities of long-term PWD history sites. Then, due to their ecological importance for PWN survival, representatives of the main ophiostomatoid fungi isolated (Ophiostoma, Leptographium, and Graphilbum) were characterized for their adaptative response to temperature, competition in-between taxa, and as food source for PWN. Under the conditions studied, Leptographium isolates showed promising results for PWN control. They could outcompete the other species, especially O. ips, and significantly reduce the development of PWN populations when compared to Botrytis cinerea (routinely used for PWN lab culturing), suggesting this to be a natural antagonist not only for the other blue-stain species but also for the PWN.
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Affiliation(s)
- Cláudia S. L. Vicente
- MED - Mediterranean Institute for Agriculture, Environment and Development & CHANGE - Global Change and Sustainability Institute, Institute for Advanced Studies and Research, Universidade de Évora - Pólo da Mitra, Évora, Portugal
- Instituto Nacional de Investigação Agrária e Veterinária (INIAV, I.P.), Quinta do Marquês, Oeiras, Portugal
| | - Miguel Soares
- Laboratório de Patologia Vegetal “Veríssimo de Almeida” (LPVVA), Instituto Superior de Agronomia (ISA), University of Lisbon, Lisboa, Portugal
| | - Jorge M. S. Faria
- Instituto Nacional de Investigação Agrária e Veterinária (INIAV, I.P.), Quinta do Marquês, Oeiras, Portugal
| | - Margarida Espada
- MED - Mediterranean Institute for Agriculture, Environment and Development & CHANGE - Global Change and Sustainability Institute, Institute for Advanced Studies and Research, Universidade de Évora - Pólo da Mitra, Évora, Portugal
| | - Manuel Mota
- MED - Mediterranean Institute for Agriculture, Environment and Development & CHANGE - Global Change and Sustainability Institute, Department of Biology, Universidade de Évora - Pólo da Mitra, Évora, Portugal
| | - Filomena Nóbrega
- Instituto Nacional de Investigação Agrária e Veterinária (INIAV, I.P.), Quinta do Marquês, Oeiras, Portugal
| | - Ana P. Ramos
- Laboratório de Patologia Vegetal “Veríssimo de Almeida” (LPVVA), Instituto Superior de Agronomia (ISA), University of Lisbon, Lisboa, Portugal
| | - Maria L. Inácio
- Instituto Nacional de Investigação Agrária e Veterinária (INIAV, I.P.), Quinta do Marquês, Oeiras, Portugal
- GREEN-IT Bioresources for Sustainability, ITQB NOVA, Oeiras, Portugal
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Persistence of ecologically similar fungi in a restricted floral niche. Antonie van Leeuwenhoek 2022; 115:761-771. [PMID: 35389142 DOI: 10.1007/s10482-022-01732-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 03/19/2022] [Indexed: 10/18/2022]
Abstract
Fungi in the genera Knoxdaviesia and Sporothrix dominate fungal communities within Protea flowerheads and seed cones (infructescences). Despite apparently similar ecologies, they show strong host recurrence and often occupy the same individual infructescence. Differences in host chemistry explain their host consistency, but the factors that allow co-occupancy of multiple species within individual infructescences are unknown. Sporothrix splendens and K. proteae often grow on different senescent tissue types within infructescences of their P. repens host, indicating that substrate-related differences aid their co-occupancy. Sporothrix phasma and K. capensis grow on the same tissues of P. neriifolia suggesting neutral competitive abilities. Here we test the hypothesis that differences in host-tissues dictate competitive abilities of these fungi and explain their co-occupancy of this spatially restricted niche. Media were prepared from infructescence bases, bracts, seeds, or pollen presenters of P. neriifolia and P. repens. As expected, K. capensis was unable to grow on seeds whilst S. phasma could. As hypothesised, K. capensis and S. phasma had equal competitive abilities on pollen presenters, appearing to explain their co-occupancy of this resource. Growth of K. proteae was significantly enhanced on pollen presenters while that of S. splendens was the same as the control. Knoxdavesia proteae grew significantly faster than S. splendens on all tissue types. Despite this, S. splendens was a superior competitor on all tissue types. For K. proteae to co-occupy infructescences with S. splendens for extended periods, it likely needs to colonize pollen presenters before the arrival of S. splendens.
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Mukwevho VO, Dreyer LL, Roets F. Early colonization of Protea flowers enable dominance of competitively weak saprobic fungi in seed cones, benefitting their hosts. Fungal Biol 2021; 126:122-131. [DOI: 10.1016/j.funbio.2021.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/05/2021] [Accepted: 11/11/2021] [Indexed: 11/04/2022]
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Zubaer A, Wai A, Patel N, Perillo J, Hausner G. The Mitogenomes of Ophiostoma minus and Ophiostoma piliferum and Comparisons With Other Members of the Ophiostomatales. Front Microbiol 2021; 12:618649. [PMID: 33643245 PMCID: PMC7902536 DOI: 10.3389/fmicb.2021.618649] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 01/04/2021] [Indexed: 12/23/2022] Open
Abstract
Fungi assigned to the Ophiostomatales are of economic concern as many are blue-stain fungi and some are plant pathogens. The mitogenomes of two blue-stain fungi, Ophiostoma minus and Ophiostoma piliferum, were sequenced and compared with currently available mitogenomes for other members of the Ophiostomatales. Species representing various genera within the Ophiostomatales have been examined for gene content, gene order, phylogenetic relationships, and the distribution of mobile elements. Gene synteny is conserved among the Ophiostomatales but some members were missing the atp9 gene. A genome wide intron landscape has been prepared to demonstrate the distribution of the mobile genetic elements (group I and II introns and homing endonucleases) and to provide insight into the evolutionary dynamics of introns among members of this group of fungi. Examples of complex introns or nested introns composed of two or three intron modules have been observed in some species. The size variation among the mitogenomes (from 23.7 kb to about 150 kb) is mostly due to the presence and absence of introns. Members of the genus Sporothrix sensu stricto appear to have the smallest mitogenomes due to loss of introns. The taxonomy of the Ophiostomatales has recently undergone considerable revisions; however, some lineages remain unresolved. The data showed that genera such as Raffaelea appear to be polyphyletic and the separation of Sporothrix sensu stricto from Ophiostoma is justified.
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Affiliation(s)
- Abdullah Zubaer
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Alvan Wai
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Nikita Patel
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Jordan Perillo
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
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Min Wang H, Wang Z, Liu F, Xu Wu C, Fang Zhang S, Kong XB, Decock C, Lu Q, Zhang Z. Differential patterns of ophiostomatoid fungal communities associated with three sympatric Tomicus species infesting pines in south-western China, with a description of four new species. MycoKeys 2019; 50:93-133. [PMID: 31043857 PMCID: PMC6477840 DOI: 10.3897/mycokeys.50.32653] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 03/09/2019] [Indexed: 12/03/2022] Open
Abstract
Bark beetles and their associated fungi, which cause forest decline and sometimes high mortality in large areas around the world, are of increasing concern in terms of forest health. Three Tomicus spp. (T.brevipilosus, T.minor and T.yunnanensis) infect branches and trunks of Pinusyunnanensis and P.kesiya in Yunnan Province, in south-western China. Tomicus spp. are well known as vectors of ophiostomatoid fungi and their co-occurrence could result in serious ecological and economic impact on local forest ecosystems. Nonetheless, knowledge about their diversity, ecology, including pathogenicity and potential economic importance is still quite rudimentary. Therefore, an extensive survey of ophiostomatoid fungi associated with these Tomicus species infesting P.yunnanensis and P.kesiya was carried out in Yunnan. Seven hundred and seventy-two strains of ophiostomatoid fungi were isolated from the adult beetles and their galleries. The strains were identified based on comparisons of multiple DNA sequences, including the nuclear ribosomal large subunit (LSU) region, the internal transcribed spacer regions 1 and 2, together with the intervening 5.8S gene (ITS) and the partial genes of β-tubulin (TUB2), elongation factor 1α (TEF1-α) and calmodulin (CAL). Phylogenetic analyses were performed using maximum parsimony (MP) as well as maximum likelihood (ML). Combinations of culture features, morphological characters and temperature-dependent growth rates were also employed for species identification. Eleven species belonging to five genera were identified. These included six known species, Esteyavermicola, Leptographiumyunnanense, Ophiostomabrevipilosi, O.canum, O.minus and O.tingens and four novel taxa, described as Graphilbumanningense, O.aggregatum, Sporothrixpseudoabietina and S.macroconidia. A residual strain was left unidentified as Ophiostoma sp. 1. The overall ophiostomatoid community was by far dominated by three species, representing 87.3% of the total isolates; in decreasing order, these were O.canum, O.brevipilosi and O.minus. Furthermore, the ophiostomatoid community of each beetle, although harbouring a diversity of ophiostomatoid species, was differentially dominated by a single fungal species; Ophiostomacanum was preferentially associated with and dominated the ophiostomatoid community of T.minor, whereas O.brevipilosi and O.minus were exclusively associated with and dominated the ophiostomatoid communities of T.brevipilosus and T.yunnanensis, respectively. Eight additional species, representing the remaining 12.7% of the total isolates, were marginal or sporadic. These results suggested that sympatric Tomicus populations are dominated by distinct species showing some level of specificity or even exclusivity.
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Affiliation(s)
- Hui Min Wang
- Key Laboratory of Forest Protection, National Forestry and Grassland Administration; Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry Beijing China
| | - Zheng Wang
- Key Laboratory of Forest Protection, National Forestry and Grassland Administration; Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry Beijing China
| | - Fu Liu
- Key Laboratory of Forest Protection, National Forestry and Grassland Administration; Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry Beijing China
| | - Cheng Xu Wu
- Key Laboratory of Forest Protection, National Forestry and Grassland Administration; Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry Beijing China
| | - Su Fang Zhang
- Key Laboratory of Forest Protection, National Forestry and Grassland Administration; Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry Beijing China
| | - Xiang Bo Kong
- Key Laboratory of Forest Protection, National Forestry and Grassland Administration; Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry Beijing China
| | - Cony Decock
- Mycothèque de l'Université Catholique de Louvain (BCCM/MUCL), Earth and Life Institute, Microbiology, B-1348 Louvain-la-Neuve, Belgium Mycothèque de l'Université Catholique de Louvain Louvain-la-Neuve Belgium
| | - Quan Lu
- Key Laboratory of Forest Protection, National Forestry and Grassland Administration; Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry Beijing China
| | - Zhen Zhang
- Key Laboratory of Forest Protection, National Forestry and Grassland Administration; Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry Beijing China
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van de Peppel L, Aanen D, Biedermann P. Low intraspecific genetic diversity indicates asexuality and vertical transmission in the fungal cultivars of ambrosia beetles. FUNGAL ECOL 2018. [DOI: 10.1016/j.funeco.2017.11.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Adams AS, Six DL, Adams SM, Holben WE. In vitro interactions between yeasts and bacteria and the fungal symbionts of the mountain pine beetle (Dendroctonus ponderosae). MICROBIAL ECOLOGY 2008; 56:460-466. [PMID: 18322728 DOI: 10.1007/s00248-008-9364-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Revised: 12/27/2007] [Accepted: 01/12/2008] [Indexed: 05/26/2023]
Abstract
Multi-trophic interactions between prokaryotes, unicellular eukaryotes, and ecologically intertwined metazoans are presumably common in nature, yet rarely described. The mountain pine beetle, Dendroctonus ponderosae, is associated with two filamentous fungi, Grosmannia clavigera and Ophiostoma montium. Other microbes, including yeasts and bacteria, are also present in the phloem, but it is not known whether they interact with the symbiotic fungi or the host beetle. To test whether such interactions occur, we performed a suite of in vitro assays. Overall, relative yield of O. montium grown with microbes isolated from larval galleries was significantly greater than when the fungus was grown alone. Conversely, the yield of G. clavigera grown with these same microbes was less than or equal to when it was grown alone, suggesting that O. montium, and at least some microbes in larval galleries, have a mutualistic or commensal relationship, while G. clavigera and those same microbes have an antagonistic relationship. A bacterium isolated from phloem not colonized by beetles was found to inhibit growth of both G. clavigera and O. montium and appears to be an antagonist to both fungi. Our results suggest that bacteria and yeasts likely influence the distribution of mycangial fungi in the host tree, which, in turn, may affect the fitness of D. ponderosae.
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MESH Headings
- Animals
- Base Sequence
- Basidiomycota/genetics
- Basidiomycota/growth & development
- Coleoptera/microbiology
- Fungi/genetics
- Fungi/growth & development
- Molecular Sequence Data
- Phloem
- Pinus
- Polymerase Chain Reaction
- RNA, Fungal/chemistry
- RNA, Fungal/genetics
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 18S/chemistry
- RNA, Ribosomal, 18S/genetics
- Sequence Analysis, DNA
- Symbiosis/physiology
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Affiliation(s)
- Aaron S Adams
- Department of Ecosystem and Conservation Sciences, The University of Montana, Missoula, MT 59812, USA.
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Hofstetter RW, Cronin JT, Klepzig KD, Moser JC, Ayres MP. Antagonisms, mutualisms and commensalisms affect outbreak dynamics of the southern pine beetle. Oecologia 2005; 147:679-91. [PMID: 16323015 DOI: 10.1007/s00442-005-0312-0] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2005] [Accepted: 11/04/2005] [Indexed: 11/25/2022]
Abstract
Feedback from community interactions involving mutualisms are a rarely explored mechanism for generating complex population dynamics. We examined the effects of two linked mutualisms on the population dynamics of a beetle that exhibits outbreak dynamics. One mutualism involves an obligate association between the bark beetle, Dendroctonus frontalis and two mycangial fungi. The second mutualism involves Tarsonemus mites that are phoretic on D. frontalis ("commensal"), and a blue-staining fungus, Ophiostoma minus. The presence of O. minus reduces beetle larval survival ("antagonistic") by outcompeting beetle-mutualistic fungi within trees yet supports mite populations by acting as a nutritional mutualist. These linked interactions potentially create an interaction system with the form of an endogenous negative feedback loop. We address four hypotheses: (1) Direct negative feedback: Beetles directly increase the abundance of O. minus, which reduces per capita reproduction of beetles. (2) Indirect negative feedback: Beetles indirectly increase mite abundance, which increases O. minus, which decreases beetle reproduction. (3) The effect of O. minus on beetles depends on mites, but mite abundance is independent of beetle abundance. (4) The effect of O. minus on beetles is independent of beetle and mite abundance. High Tarsonemus and O. minus abundances were strongly correlated with the decline and eventual local extinction of beetle populations. Manipulation experiments revealed strong negative effects of O. minus on beetles, but falsified the hypothesis that horizontal transmission of O. minus generates negative feedback. Surveys of beetle populations revealed that reproductive rates of Tarsonemus, O. minus, and beetles covaried in a manner consistent with strong indirect interactions between organisms. Co-occurrence of mutualisms embedded within a community may have stabilizing effects if both mutualisms limit each other. However, delays and/or non-linearities in the interaction systems may result in large population fluctuations.
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