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Jolanta Miadlikowska - One of the best experts on this subject based on the ideXlab platform.
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species diversification and phylogenetically constrained symbiont switching generated high modularity in the lichen genus Peltigera
Journal of Ecology, 2019Co-Authors: Pierreluc Chagnon, Jolanta Miadlikowska, Nicolas Magain, Francois LutzoniAbstract:Ecological interactions range from purely specialized to extremely generalized in nature. Recent research has showed very high levels of specialization in the cyanolichens involving Peltigera (mycobionts) and their Nostoc photosynthetic partners (cyanobionts). Yet, little is known about the mechanisms contributing to the establishment and maintenance of such high specialization levels. Here, we characterized interactions between Peltigera and Nostoc partners at a global scale, using more than one thousand thalli. We used tools from network theory, community phylogenetics and biogeographical history reconstruction to evaluate how these symbiotic interactions may have evolved. After splitting the interaction matrix into modules of preferentially interacting partners, we evaluated how module membership might have evolved along the mycobionts’ phylogeny. We also teased apart the contributions of geographical overlap vs phylogeny in driving interaction establishment between Peltigera and Nostoc taxa. Module affiliation rarely evolves through the splitting of large ancestral modules. Instead, new modules appear to emerge independently, which is often associated with a fungal speciation event. We also found strong phylogenetic signal in these interactions, which suggests that partner switching is constrained by conserved traits. Therefore, it seems that a high rate of fungal diversification following a switch to a new cyanobiont can lead to the formation of large modules, with cyanobionts associating with multiple closely retated Peltigera species. Finally, when restricting our analyses to Peltigera sister species, the latter differed more through partner acquisition/loss than replacement (i.e., switching). This pattern vanishes as we look at sister species that have diverged longer ago. This suggests that fungal speciation may be accompanied by a stepwise process of (a) novel partner acquisition and (b) loss of the ancestral partner. This could explain the maintenance of high specialization levels in this symbiotic system where the transmission of the cyanobiont to the next generation is assumed to be predominantly horizontal. Synthesis. Overall, our study suggests that oscillation between generalization and ancestral partner loss may maintain high specialization within the lichen genus Peltigera, and that partner selection is not only driven by partners’ geographical overlap, but also by their phylogenetically conserved traits.
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bioclimatic factors at an intrabiome scale are more limiting than cyanobiont availability for the lichen forming genus Peltigera
American Journal of Botany, 2018Co-Authors: Jade Lu, Jolanta Miadlikowska, Nicolas Magain, Jessica R Coyle, Camille Truong, Francois LutzoniAbstract:PREMISE OF THE STUDY: Factors shaping spatiotemporal patterns of associations in mutualistic systems are poorly understood. We used the lichen-forming fungi Peltigera and their cyanobacterial partners Nostoc to investigate the spatial structure of this symbiosis at an intrabiome scale and to identify potential factors shaping these associations. METHODS: Ninety-three thalli were sampled in Quebec, Canada, along a south-north and an east-west transect of ~1300 km each. We identified the two main partners (Peltigera species and Nostoc phylogroups) using molecular markers and modeled the effects of environmental variables and partner occurrence on Peltigera-Nostoc distributions. KEY RESULTS: Peltigera species showed a high degree of specialization toward cyanobionts, whereas two Nostoc phylogroups dominated both transects by associating with several Peltigera species. Peltigera species had narrower ranges than these two main cyanobionts. Distributions of three Peltigera species were highly associated with precipitation and temperature variables, which was not detected for Nostoc phylogroups at this spatial scale. CONCLUSIONS: For these cyanolichens, factors driving patterns of symbiotic associations are scale dependent. Contrary to global-scale findings, generalist Peltigera species were not more widespread within the boreal biome than specialists. Nostoc availability was not the only driver of Peltigera species' geographic ranges; environmental factors also contributed to their intrabiome distributions. Climatic conditions (especially precipitation) limited the range of some Peltigera species more than the range of their cyanobacterial partners at an intrabiome (boreal) scale.
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strong specificity and network modularity at a very fine phylogenetic scale in the lichen genus Peltigera
Oecologia, 2018Co-Authors: Pierreluc Chagnon, Jolanta Miadlikowska, Nicolas Magain, Francois LutzoniAbstract:Identifying the drivers and evolutionary consequences of species interactions is a major goal of community ecology. Network-based analyses can provide mathematical tools to detect non-random patterns of interactions, and potentially help predicting the consequences of such patterns on evolutionary dynamics of symbiotic systems. Here, we characterize the structure of a lichen network at a very fine phylogenetic scale, by identifying the photosynthetic partners (i.e., cyanobacteria of the genus Nostoc) of lichenized fungi belonging to a monophyletic section of a single genus (i.e., section Polydactylon of the genus Peltigera), worldwide. Even at such a fine phylogenetic scale, we found that interactions were highly modular and anti-nested, indicating strong preferences in interactions. When considering local Peltigera communities, i.e., datasets at small spatial scales with only a slightly broader phylogenetic range, interactions remained modular but were asymmetric, with generalist Nostoc partners interacting with specialized Peltigera species. This asymmetry was not detected with our global spatial scale dataset. We discuss these results in the light of lichen community assembly, and explore how such interaction patterns may influence coevolution in lichens and the evolutionary stability of the mutualism in general.
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contrasting symbiotic patterns in two closely related lineages of trimembered lichens of the genus Peltigera
Frontiers in Microbiology, 2018Co-Authors: Nicolas Magain, Trevor Goward, Francois Lutzoni, Silvia Restrepo, Jolanta MiadlikowskaAbstract:Species circumscription is key to the characterization of patterns of specificity in symbiotic systems at a macroevolutionary scale. Here, a worldwide phylogenetic framework was used to assess the biodiversity and symbiotic patterns of association among partners in trimembered lichens from the genus Peltigera, section ChloroPeltigera. We sequenced six loci of the main fungal partner and performed species discovery and validation analyses to establish putative species boundaries. Single locus phylogenies were used to establish the identity of both photobionts, Nostoc (cyanobacterium) and Coccomyxa (green alga). Distribution and specificity patterns were compared to the closely related clade, section Peltidea, which includes mainly Peltigera species with trimembered thalli. For section ChloroPeltigera, eight fungal species (including five newly delimited putative species) were found in association with nine Nostoc phylogroups and two Coccomyxa species. In contrast, eight fungal species (including three newly delimited putative species) in section Peltidea were found in association with only four Nostoc phylogroups and the same two Coccomyxa species as for section ChloroPeltigera. This difference in cyanobiont biodiversity between these two sections can potentially be explained by a significantly higher frequency of sexual reproductive structures in species from section ChloroPeltigera compared to section Peltidea. Therefore, horizontal transmission of the cyanobiont might be more prevalent in ChloroPeltigera species, while vertical transmission might be more common in Peltidea species. All Peltigera species in section ChloroPeltigera are generalists in their association with Nostoc compared to more specialized Peltigera species in section Peltidea. Constrained distributions of Peltigera species that associate strictly with one species of green algae (Coccomyxa subellipsoidea) indicate that the availability of the green alga and the specificity of the interaction might be important factors limiting geographic ranges of trimembered Peltigera, in addition to constraints imposed by their interaction with Nostoc partners and by climatic factors.
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disentangling the Peltigera polydactylon species complex by recognizing two new taxa p polydactylon subsp udeghe and p seneca
Herzogia, 2016Co-Authors: Nicolas Magain, Mikhail P Zhurbenko, Francois Lutzoni, Emmanuel Serusiaux, Jolanta MiadlikowskaAbstract:Magain, N., Serusiaux, E., Zhurbenko, M. P., Lutzoni, F. & Miadlikowska, J. 2016. Disentangling the Peltigera polydactylon species complex by recognizing two new taxa, P. polydactylon subsp. udeghe and P. seneca. — Herzogia 29: 514–528.A new species, Peltigera seneca, and two subspecies within P. polydactylon (s.str.), P. polydactylon subsp. udeghe and P. polydactylon subsp. polydactylon, were segregated from a broadly defined P. polydactylon s.lat., based mostly on molecular data and distinct geographical ranges. Peltigera polydactylon s.str. and P. seneca form well-supported monophyletic lineages that share a most recent common ancestor and were recognized as two distinct species by multiple species delimitation and validation methods. Peltigera polydactylon s. str. has a broad intercontinental distribution whereas the new species P. seneca is restricted to eastern North America where it seems to be rare. Peltigera polydactylon subsp. udeghe and P. polydactylon subsp. polydactylon, were defined to accommodate two monophyletic and strongly supported clades separated geographically (North America, eastern Northern Asia and Australasia versus Europe, Middle East and central Northern Asia, respectively). Despite the low genetic distance, especially for the ITS, between these two subspecies, they are well segregated genetically throughout their allopatric ranges. However, there seems to be an intermediary pattern of variation in the geographical area where both taxa are likely to co-occur (e.g., central and eastern Northern Asia). Phenotypic traits have limited value in distinguishing these three taxa. They are chemically (secondary metabolites) similar and share the same Nostoc (cyanobiont) phylogroup. Nevertheless, there are helpful phenotypic trends in addition to their diagnostic genotypes.
Francois Lutzoni - One of the best experts on this subject based on the ideXlab platform.
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species diversification and phylogenetically constrained symbiont switching generated high modularity in the lichen genus Peltigera
Journal of Ecology, 2019Co-Authors: Pierreluc Chagnon, Jolanta Miadlikowska, Nicolas Magain, Francois LutzoniAbstract:Ecological interactions range from purely specialized to extremely generalized in nature. Recent research has showed very high levels of specialization in the cyanolichens involving Peltigera (mycobionts) and their Nostoc photosynthetic partners (cyanobionts). Yet, little is known about the mechanisms contributing to the establishment and maintenance of such high specialization levels. Here, we characterized interactions between Peltigera and Nostoc partners at a global scale, using more than one thousand thalli. We used tools from network theory, community phylogenetics and biogeographical history reconstruction to evaluate how these symbiotic interactions may have evolved. After splitting the interaction matrix into modules of preferentially interacting partners, we evaluated how module membership might have evolved along the mycobionts’ phylogeny. We also teased apart the contributions of geographical overlap vs phylogeny in driving interaction establishment between Peltigera and Nostoc taxa. Module affiliation rarely evolves through the splitting of large ancestral modules. Instead, new modules appear to emerge independently, which is often associated with a fungal speciation event. We also found strong phylogenetic signal in these interactions, which suggests that partner switching is constrained by conserved traits. Therefore, it seems that a high rate of fungal diversification following a switch to a new cyanobiont can lead to the formation of large modules, with cyanobionts associating with multiple closely retated Peltigera species. Finally, when restricting our analyses to Peltigera sister species, the latter differed more through partner acquisition/loss than replacement (i.e., switching). This pattern vanishes as we look at sister species that have diverged longer ago. This suggests that fungal speciation may be accompanied by a stepwise process of (a) novel partner acquisition and (b) loss of the ancestral partner. This could explain the maintenance of high specialization levels in this symbiotic system where the transmission of the cyanobiont to the next generation is assumed to be predominantly horizontal. Synthesis. Overall, our study suggests that oscillation between generalization and ancestral partner loss may maintain high specialization within the lichen genus Peltigera, and that partner selection is not only driven by partners’ geographical overlap, but also by their phylogenetically conserved traits.
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bioclimatic factors at an intrabiome scale are more limiting than cyanobiont availability for the lichen forming genus Peltigera
American Journal of Botany, 2018Co-Authors: Jade Lu, Jolanta Miadlikowska, Nicolas Magain, Jessica R Coyle, Camille Truong, Francois LutzoniAbstract:PREMISE OF THE STUDY: Factors shaping spatiotemporal patterns of associations in mutualistic systems are poorly understood. We used the lichen-forming fungi Peltigera and their cyanobacterial partners Nostoc to investigate the spatial structure of this symbiosis at an intrabiome scale and to identify potential factors shaping these associations. METHODS: Ninety-three thalli were sampled in Quebec, Canada, along a south-north and an east-west transect of ~1300 km each. We identified the two main partners (Peltigera species and Nostoc phylogroups) using molecular markers and modeled the effects of environmental variables and partner occurrence on Peltigera-Nostoc distributions. KEY RESULTS: Peltigera species showed a high degree of specialization toward cyanobionts, whereas two Nostoc phylogroups dominated both transects by associating with several Peltigera species. Peltigera species had narrower ranges than these two main cyanobionts. Distributions of three Peltigera species were highly associated with precipitation and temperature variables, which was not detected for Nostoc phylogroups at this spatial scale. CONCLUSIONS: For these cyanolichens, factors driving patterns of symbiotic associations are scale dependent. Contrary to global-scale findings, generalist Peltigera species were not more widespread within the boreal biome than specialists. Nostoc availability was not the only driver of Peltigera species' geographic ranges; environmental factors also contributed to their intrabiome distributions. Climatic conditions (especially precipitation) limited the range of some Peltigera species more than the range of their cyanobacterial partners at an intrabiome (boreal) scale.
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strong specificity and network modularity at a very fine phylogenetic scale in the lichen genus Peltigera
Oecologia, 2018Co-Authors: Pierreluc Chagnon, Jolanta Miadlikowska, Nicolas Magain, Francois LutzoniAbstract:Identifying the drivers and evolutionary consequences of species interactions is a major goal of community ecology. Network-based analyses can provide mathematical tools to detect non-random patterns of interactions, and potentially help predicting the consequences of such patterns on evolutionary dynamics of symbiotic systems. Here, we characterize the structure of a lichen network at a very fine phylogenetic scale, by identifying the photosynthetic partners (i.e., cyanobacteria of the genus Nostoc) of lichenized fungi belonging to a monophyletic section of a single genus (i.e., section Polydactylon of the genus Peltigera), worldwide. Even at such a fine phylogenetic scale, we found that interactions were highly modular and anti-nested, indicating strong preferences in interactions. When considering local Peltigera communities, i.e., datasets at small spatial scales with only a slightly broader phylogenetic range, interactions remained modular but were asymmetric, with generalist Nostoc partners interacting with specialized Peltigera species. This asymmetry was not detected with our global spatial scale dataset. We discuss these results in the light of lichen community assembly, and explore how such interaction patterns may influence coevolution in lichens and the evolutionary stability of the mutualism in general.
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contrasting symbiotic patterns in two closely related lineages of trimembered lichens of the genus Peltigera
Frontiers in Microbiology, 2018Co-Authors: Nicolas Magain, Trevor Goward, Francois Lutzoni, Silvia Restrepo, Jolanta MiadlikowskaAbstract:Species circumscription is key to the characterization of patterns of specificity in symbiotic systems at a macroevolutionary scale. Here, a worldwide phylogenetic framework was used to assess the biodiversity and symbiotic patterns of association among partners in trimembered lichens from the genus Peltigera, section ChloroPeltigera. We sequenced six loci of the main fungal partner and performed species discovery and validation analyses to establish putative species boundaries. Single locus phylogenies were used to establish the identity of both photobionts, Nostoc (cyanobacterium) and Coccomyxa (green alga). Distribution and specificity patterns were compared to the closely related clade, section Peltidea, which includes mainly Peltigera species with trimembered thalli. For section ChloroPeltigera, eight fungal species (including five newly delimited putative species) were found in association with nine Nostoc phylogroups and two Coccomyxa species. In contrast, eight fungal species (including three newly delimited putative species) in section Peltidea were found in association with only four Nostoc phylogroups and the same two Coccomyxa species as for section ChloroPeltigera. This difference in cyanobiont biodiversity between these two sections can potentially be explained by a significantly higher frequency of sexual reproductive structures in species from section ChloroPeltigera compared to section Peltidea. Therefore, horizontal transmission of the cyanobiont might be more prevalent in ChloroPeltigera species, while vertical transmission might be more common in Peltidea species. All Peltigera species in section ChloroPeltigera are generalists in their association with Nostoc compared to more specialized Peltigera species in section Peltidea. Constrained distributions of Peltigera species that associate strictly with one species of green algae (Coccomyxa subellipsoidea) indicate that the availability of the green alga and the specificity of the interaction might be important factors limiting geographic ranges of trimembered Peltigera, in addition to constraints imposed by their interaction with Nostoc partners and by climatic factors.
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disentangling the Peltigera polydactylon species complex by recognizing two new taxa p polydactylon subsp udeghe and p seneca
Herzogia, 2016Co-Authors: Nicolas Magain, Mikhail P Zhurbenko, Francois Lutzoni, Emmanuel Serusiaux, Jolanta MiadlikowskaAbstract:Magain, N., Serusiaux, E., Zhurbenko, M. P., Lutzoni, F. & Miadlikowska, J. 2016. Disentangling the Peltigera polydactylon species complex by recognizing two new taxa, P. polydactylon subsp. udeghe and P. seneca. — Herzogia 29: 514–528.A new species, Peltigera seneca, and two subspecies within P. polydactylon (s.str.), P. polydactylon subsp. udeghe and P. polydactylon subsp. polydactylon, were segregated from a broadly defined P. polydactylon s.lat., based mostly on molecular data and distinct geographical ranges. Peltigera polydactylon s.str. and P. seneca form well-supported monophyletic lineages that share a most recent common ancestor and were recognized as two distinct species by multiple species delimitation and validation methods. Peltigera polydactylon s. str. has a broad intercontinental distribution whereas the new species P. seneca is restricted to eastern North America where it seems to be rare. Peltigera polydactylon subsp. udeghe and P. polydactylon subsp. polydactylon, were defined to accommodate two monophyletic and strongly supported clades separated geographically (North America, eastern Northern Asia and Australasia versus Europe, Middle East and central Northern Asia, respectively). Despite the low genetic distance, especially for the ITS, between these two subspecies, they are well segregated genetically throughout their allopatric ranges. However, there seems to be an intermediary pattern of variation in the geographical area where both taxa are likely to co-occur (e.g., central and eastern Northern Asia). Phenotypic traits have limited value in distinguishing these three taxa. They are chemically (secondary metabolites) similar and share the same Nostoc (cyanobiont) phylogroup. Nevertheless, there are helpful phenotypic trends in addition to their diagnostic genotypes.
Stefano Loppi - One of the best experts on this subject based on the ideXlab platform.
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antiproliferative activity of three lichen species belonging to the genus Peltigera
Plant Biosystems, 2014Co-Authors: Silvana Munzi, Doriana Triggiani, Donatella Ceccarelli, Elisa Climati, A Tiezzi, Tommaso Pisani, Luca Paoli, Stefano LoppiAbstract:The results of antiproliferative activity against murine myeloma cells (line P3X63-Ag8.653) of water, ethanol, and methanol crude extracts of three lichen species belonging to the genus Peltigera (P. canina, P. elisabethae, and P. praetextata) are reported. Cell proliferation was evaluated by means of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test, which is commonly used to assess the activity of living cells through mitochondrial dehydrogenases. The results showed that water extracts were the most effective in reducing cell proliferation; however, 40 μl of all Peltigera extracts, irrespective of water, ethanol, or methanol, induced a consistent reduction in cell proliferation. It is suggested that this important biological activity is due to antioxidant properties, possibly linked with phenolic compounds. A possible role of quaternary ammonium compounds is also discussed.
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physiological effects of mercury in the lichens cladonia arbuscula subsp mitis sandst ruoss and Peltigera rufescens weiss humb
Chemosphere, 2011Co-Authors: Tommaso Pisani, Martin Backor, Jozef Kovacik, Silvana Munzi, Luca Paoli, Juraj Piovar, Stefano LoppiAbstract:This study aimed at investigating the cellular distribution of Hg in the lichens Cladonia arbuscula subsp. mitis and Peltigera rufescens treated with Hg2+ and at testing if Hg treatment affects selected physiological parameters. In both species, increasing Hg accumulation under increasing Hg supply in the treatment solutions was found. P. rufescens showed a higher intracellular accumulation. Photosynthetic parameters were negatively affected in both species, as indicated by the decrease in photosynthetic pigments content, photosynthetic efficiency and chlorophyll integrity. Cell membranes of both species endured damage as indicated by the increase in the concentration of products of lipid peroxidation and decrease in ergosterol content. Nevertheless, differences between the two species were found, suggesting a differential sensitivity to Hg.
Nicolas Magain - One of the best experts on this subject based on the ideXlab platform.
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species diversification and phylogenetically constrained symbiont switching generated high modularity in the lichen genus Peltigera
Journal of Ecology, 2019Co-Authors: Pierreluc Chagnon, Jolanta Miadlikowska, Nicolas Magain, Francois LutzoniAbstract:Ecological interactions range from purely specialized to extremely generalized in nature. Recent research has showed very high levels of specialization in the cyanolichens involving Peltigera (mycobionts) and their Nostoc photosynthetic partners (cyanobionts). Yet, little is known about the mechanisms contributing to the establishment and maintenance of such high specialization levels. Here, we characterized interactions between Peltigera and Nostoc partners at a global scale, using more than one thousand thalli. We used tools from network theory, community phylogenetics and biogeographical history reconstruction to evaluate how these symbiotic interactions may have evolved. After splitting the interaction matrix into modules of preferentially interacting partners, we evaluated how module membership might have evolved along the mycobionts’ phylogeny. We also teased apart the contributions of geographical overlap vs phylogeny in driving interaction establishment between Peltigera and Nostoc taxa. Module affiliation rarely evolves through the splitting of large ancestral modules. Instead, new modules appear to emerge independently, which is often associated with a fungal speciation event. We also found strong phylogenetic signal in these interactions, which suggests that partner switching is constrained by conserved traits. Therefore, it seems that a high rate of fungal diversification following a switch to a new cyanobiont can lead to the formation of large modules, with cyanobionts associating with multiple closely retated Peltigera species. Finally, when restricting our analyses to Peltigera sister species, the latter differed more through partner acquisition/loss than replacement (i.e., switching). This pattern vanishes as we look at sister species that have diverged longer ago. This suggests that fungal speciation may be accompanied by a stepwise process of (a) novel partner acquisition and (b) loss of the ancestral partner. This could explain the maintenance of high specialization levels in this symbiotic system where the transmission of the cyanobiont to the next generation is assumed to be predominantly horizontal. Synthesis. Overall, our study suggests that oscillation between generalization and ancestral partner loss may maintain high specialization within the lichen genus Peltigera, and that partner selection is not only driven by partners’ geographical overlap, but also by their phylogenetically conserved traits.
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bioclimatic factors at an intrabiome scale are more limiting than cyanobiont availability for the lichen forming genus Peltigera
American Journal of Botany, 2018Co-Authors: Jade Lu, Jolanta Miadlikowska, Nicolas Magain, Jessica R Coyle, Camille Truong, Francois LutzoniAbstract:PREMISE OF THE STUDY: Factors shaping spatiotemporal patterns of associations in mutualistic systems are poorly understood. We used the lichen-forming fungi Peltigera and their cyanobacterial partners Nostoc to investigate the spatial structure of this symbiosis at an intrabiome scale and to identify potential factors shaping these associations. METHODS: Ninety-three thalli were sampled in Quebec, Canada, along a south-north and an east-west transect of ~1300 km each. We identified the two main partners (Peltigera species and Nostoc phylogroups) using molecular markers and modeled the effects of environmental variables and partner occurrence on Peltigera-Nostoc distributions. KEY RESULTS: Peltigera species showed a high degree of specialization toward cyanobionts, whereas two Nostoc phylogroups dominated both transects by associating with several Peltigera species. Peltigera species had narrower ranges than these two main cyanobionts. Distributions of three Peltigera species were highly associated with precipitation and temperature variables, which was not detected for Nostoc phylogroups at this spatial scale. CONCLUSIONS: For these cyanolichens, factors driving patterns of symbiotic associations are scale dependent. Contrary to global-scale findings, generalist Peltigera species were not more widespread within the boreal biome than specialists. Nostoc availability was not the only driver of Peltigera species' geographic ranges; environmental factors also contributed to their intrabiome distributions. Climatic conditions (especially precipitation) limited the range of some Peltigera species more than the range of their cyanobacterial partners at an intrabiome (boreal) scale.
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strong specificity and network modularity at a very fine phylogenetic scale in the lichen genus Peltigera
Oecologia, 2018Co-Authors: Pierreluc Chagnon, Jolanta Miadlikowska, Nicolas Magain, Francois LutzoniAbstract:Identifying the drivers and evolutionary consequences of species interactions is a major goal of community ecology. Network-based analyses can provide mathematical tools to detect non-random patterns of interactions, and potentially help predicting the consequences of such patterns on evolutionary dynamics of symbiotic systems. Here, we characterize the structure of a lichen network at a very fine phylogenetic scale, by identifying the photosynthetic partners (i.e., cyanobacteria of the genus Nostoc) of lichenized fungi belonging to a monophyletic section of a single genus (i.e., section Polydactylon of the genus Peltigera), worldwide. Even at such a fine phylogenetic scale, we found that interactions were highly modular and anti-nested, indicating strong preferences in interactions. When considering local Peltigera communities, i.e., datasets at small spatial scales with only a slightly broader phylogenetic range, interactions remained modular but were asymmetric, with generalist Nostoc partners interacting with specialized Peltigera species. This asymmetry was not detected with our global spatial scale dataset. We discuss these results in the light of lichen community assembly, and explore how such interaction patterns may influence coevolution in lichens and the evolutionary stability of the mutualism in general.
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contrasting symbiotic patterns in two closely related lineages of trimembered lichens of the genus Peltigera
Frontiers in Microbiology, 2018Co-Authors: Nicolas Magain, Trevor Goward, Francois Lutzoni, Silvia Restrepo, Jolanta MiadlikowskaAbstract:Species circumscription is key to the characterization of patterns of specificity in symbiotic systems at a macroevolutionary scale. Here, a worldwide phylogenetic framework was used to assess the biodiversity and symbiotic patterns of association among partners in trimembered lichens from the genus Peltigera, section ChloroPeltigera. We sequenced six loci of the main fungal partner and performed species discovery and validation analyses to establish putative species boundaries. Single locus phylogenies were used to establish the identity of both photobionts, Nostoc (cyanobacterium) and Coccomyxa (green alga). Distribution and specificity patterns were compared to the closely related clade, section Peltidea, which includes mainly Peltigera species with trimembered thalli. For section ChloroPeltigera, eight fungal species (including five newly delimited putative species) were found in association with nine Nostoc phylogroups and two Coccomyxa species. In contrast, eight fungal species (including three newly delimited putative species) in section Peltidea were found in association with only four Nostoc phylogroups and the same two Coccomyxa species as for section ChloroPeltigera. This difference in cyanobiont biodiversity between these two sections can potentially be explained by a significantly higher frequency of sexual reproductive structures in species from section ChloroPeltigera compared to section Peltidea. Therefore, horizontal transmission of the cyanobiont might be more prevalent in ChloroPeltigera species, while vertical transmission might be more common in Peltidea species. All Peltigera species in section ChloroPeltigera are generalists in their association with Nostoc compared to more specialized Peltigera species in section Peltidea. Constrained distributions of Peltigera species that associate strictly with one species of green algae (Coccomyxa subellipsoidea) indicate that the availability of the green alga and the specificity of the interaction might be important factors limiting geographic ranges of trimembered Peltigera, in addition to constraints imposed by their interaction with Nostoc partners and by climatic factors.
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disentangling the Peltigera polydactylon species complex by recognizing two new taxa p polydactylon subsp udeghe and p seneca
Herzogia, 2016Co-Authors: Nicolas Magain, Mikhail P Zhurbenko, Francois Lutzoni, Emmanuel Serusiaux, Jolanta MiadlikowskaAbstract:Magain, N., Serusiaux, E., Zhurbenko, M. P., Lutzoni, F. & Miadlikowska, J. 2016. Disentangling the Peltigera polydactylon species complex by recognizing two new taxa, P. polydactylon subsp. udeghe and P. seneca. — Herzogia 29: 514–528.A new species, Peltigera seneca, and two subspecies within P. polydactylon (s.str.), P. polydactylon subsp. udeghe and P. polydactylon subsp. polydactylon, were segregated from a broadly defined P. polydactylon s.lat., based mostly on molecular data and distinct geographical ranges. Peltigera polydactylon s.str. and P. seneca form well-supported monophyletic lineages that share a most recent common ancestor and were recognized as two distinct species by multiple species delimitation and validation methods. Peltigera polydactylon s. str. has a broad intercontinental distribution whereas the new species P. seneca is restricted to eastern North America where it seems to be rare. Peltigera polydactylon subsp. udeghe and P. polydactylon subsp. polydactylon, were defined to accommodate two monophyletic and strongly supported clades separated geographically (North America, eastern Northern Asia and Australasia versus Europe, Middle East and central Northern Asia, respectively). Despite the low genetic distance, especially for the ITS, between these two subspecies, they are well segregated genetically throughout their allopatric ranges. However, there seems to be an intermediary pattern of variation in the geographical area where both taxa are likely to co-occur (e.g., central and eastern Northern Asia). Phenotypic traits have limited value in distinguishing these three taxa. They are chemically (secondary metabolites) similar and share the same Nostoc (cyanobiont) phylogroup. Nevertheless, there are helpful phenotypic trends in addition to their diagnostic genotypes.
Jozef Kovacik - One of the best experts on this subject based on the ideXlab platform.
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physiological effects of mercury in the lichens cladonia arbuscula subsp mitis sandst ruoss and Peltigera rufescens weiss humb
Chemosphere, 2011Co-Authors: Tommaso Pisani, Martin Backor, Jozef Kovacik, Silvana Munzi, Luca Paoli, Juraj Piovar, Stefano LoppiAbstract:This study aimed at investigating the cellular distribution of Hg in the lichens Cladonia arbuscula subsp. mitis and Peltigera rufescens treated with Hg2+ and at testing if Hg treatment affects selected physiological parameters. In both species, increasing Hg accumulation under increasing Hg supply in the treatment solutions was found. P. rufescens showed a higher intracellular accumulation. Photosynthetic parameters were negatively affected in both species, as indicated by the decrease in photosynthetic pigments content, photosynthetic efficiency and chlorophyll integrity. Cell membranes of both species endured damage as indicated by the increase in the concentration of products of lipid peroxidation and decrease in ergosterol content. Nevertheless, differences between the two species were found, suggesting a differential sensitivity to Hg.
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physiological adaptations in the lichens Peltigera rufescens and cladina arbuscula var mitis and the moss racomitrium lanuginosum to copper rich substrate
Chemosphere, 2009Co-Authors: Martin Backor, Bořivoj Klejdus, Ivana Vantova, Jozef KovacikAbstract:Abstract Two lichen species ( Peltigera rufescens and Cladina arbuscula subsp. mitis ) and one moss species ( Racomitrium lanuginosum ) growing on a copper mine heaps (probably 200–300 yr old) in the village of Spania dolina (Slovak Republic) were assessed for selected physiological parameters, including composition of assimilation pigments, chlorophyll a fluorescence, soluble proteins and free amino acid content. The lichen C. arbuscula subsp. mitis was collected also at a control locality where total copper concentration in the soil was approximately 3% that of the waste heaps. Concentrations of Al, Co, Cu, Ni, Sb and Zn were highest in thalli of Peltigera , while the moss Racomitrium contained the highest content of Fe and Pb. Thalli of Cladina contained less metals than the cyanolichen Peltigera , and except for Zn metal concentrations in Cladina from the control locality were lower than in thalli of the same species from copper mine heaps. Regardless of the species or locality, the composition of assimilation pigments and chlorophyll a fluorescence showed that the tested lichens and moss were in good physiological condition and adapted to increased copper levels in the soil. There were significantly different amounts of total free amino acids in Peltigera , Cladina and Racomitrium from the Cu-polluted field. However, differences in amount of free amino acids in control, as well as Cu-polluted thalli of Cladina were less pronounced.
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physiological comparison of copper toxicity in the lichens Peltigera rufescens weis humb and cladina arbuscula subsp mitis sandst ruoss
Plant Growth Regulation, 2009Co-Authors: Martin Backor, Jozef Kovacik, Alexander Dzubaj, Miriam BackorovaAbstract:Peltigera rufescens (Weis) Humb. with a prokaryotic photobiont Nostoc sp. and Cladina arbuscula subsp. mitis (Sandst.) Ruoss with a eukaryotic photobiont Trebouxia sp. were studied to determine the copper sensitivity of lichens with different algal symbionts. Samples growing on historic copper mine-spoil heaps at Ľubietova–Podlipa, Slovakia were assessed for physiological parameters, including total and intracellular uptake of copper, assimilation pigmentation, activity of photosystem II, ergosterol levels, thiobarbituric acid reactive substances and water-soluble protein content. Our results indicate that P. rufescens was more sensitive to copper exposure than C. arbuscula subsp. mitis.