Papers by Ivana Cernajova
Scientific Reports, Apr 22, 2021
We studied the biodiversity of Asterochloris photobionts found in Bolivian lichens to better unde... more We studied the biodiversity of Asterochloris photobionts found in Bolivian lichens to better understand their global spatial distribution and adaptation strategies in the context of a worldwide phylogeny of the genus. Based on nuclear ITS rDNA, the chloroplast rbcL gene and the actin type I gene we reconstructed a phylogenetic tree that recovered nine new Asterochloris lineages, while 32 Bolivian photobiont samples were assigned to 12 previously recognized Asterochloris lineages. We also show that some previously discovered Asterochloris photobiont species and lineages may occur in a broader spectrum of climatic conditions, and mycobiont species and photobionts may show different preferences along an altitude gradient. To reveal general patterns of of mycobiont specificity towards the photobiont in Asterochloris, we tested the influence of climate, altitude, geographical distance and effects of symbiotic partner (mycobiont) at the species level of three genera of lichen forming fungi: Stereocaulon, Cladonia and Lepraria. Further, we compared the specificity of mycobionts towards Asterochloris photobionts in cosmopolitan, Neotropical, and Pantropical lichen forming fungi. Interestingly, cosmopolitan species showed the lowest specificity to their photobionts, but also the lowest haplotype diversity. Neotropical and Paleotropical mycobionts, however, were more specific. Lichens are a marvelous example of ubiquitous, symbiotic fungi. Their thalli contain eukaryotic green algae and/ or cyanobacteria, which represent the photosynthetic partners and are called photobionts; however, numerous bacteria and fungi also occur in the lichen symbiosis 1-3. Many lichens are widely distributed, but it seems that photobionts in lichen symbioses may show their own habitat preferences independent of the lichenized fungus itself 4-6. Since the organisms' environmental preferences may be closely related to their distribution, the geographical patterns of the photobionts may be different from their fungal partners 5. Some phylogenetic lineages, species or OTUs (operational taxonomic units), of photobionts are globally distributed, but many photobionts have only been recorded in a specific region or habitat 5,7-9. In many cases, due to the uneven sampling of the lichen symbionts tested, it is too early to precisely define biogeographic patterns for lichenized algae; this especially applies to photobionts from the tropics 5,7. Asterochloris is one of the most common photobionts in lichen symbioses, but it is mostly restricted to certain phylogenetic lichen groups, of which undoubtedly the best sampled and studied are these associated with members of Cladonia, Lepraria and Stereocaulon 4,5,9-18. So far, eighteen species have been identified within Asterochloris 13,14,19-22. Nevertheless, recent research 5,9,14,22,23 demonstrates there are many phylogenetic Asterochloris lineages that represent still unrecognized species, which, apart from differences in the molecular markers, also differ in climate and substrate preferences. Moreover, Škaloud et al. 14 indicated that genetic diversity, ecology, biogeography and specificity to mycobiont partners should all be taken into account in species delimitation. In addition, it has been revealed that some lichens usually associated with Asterochloris spp. may have additional photobionts in their thalli, e.g., Chloroidium 9 or Vulcanochloris 9,16 .
Frontiers in Microbiology, Jan 31, 2022
Climatic factors, soil chemistry and geography are considered as major factors affecting lichen d... more Climatic factors, soil chemistry and geography are considered as major factors affecting lichen distribution and diversity. To determine how these factors limit or support the associations between the symbiotic partners, we revise the lichen symbiosis as a network of relationships here. More than one thousand thalli of terricolous Cladonia lichens were collected at sites with a wide range of soil chemical properties from seven biogeographical regions of Europe. A total of 18 OTUs of the algal genus Asterochloris and 181 OTUs of Cladonia mycobiont were identified. We displayed all realized pairwise mycobiont-photobiont relationships and performed modularity analysis. It revealed four virtually separated modules of cooperating OTUs. The modules differed in mean annual temperature, isothermality, precipitation, evapotranspiration, soil pH, nitrogen, and carbon contents. Photobiont switching was strictly limited to algae from one module, i.e., algae of similar ecological preferences, and only few mycobionts were able to cooperate with photobionts from different modules. Thus, Cladonia mycobionts generally cannot widen their ecological niches through photobiont switching. The modules also differed in the functional traits of the mycobionts, e.g., sexual reproduction rate, presence of soredia, and thallus type. These traits may represent adaptations to the environmental conditions that drive the differentiation of the modules. In conclusion, the promiscuity in Cladonia mycobionts is strictly limited by climatic factors and soil chemistry.
Fungal Biology, Sep 1, 2019
The first survey of Cystobasidiomycete yeasts in the lichen genus Cladonia; with the description ... more The first survey of Cystobasidiomycete yeasts in the lichen genus Cladonia; with the description of Lichenozyma pisutiana gen. nov., sp. nov.
We studied biodiversity of Asterochloris photobionts found in lichen symbioses in Bolivian Andean... more We studied biodiversity of Asterochloris photobionts found in lichen symbioses in Bolivian Andean vegetation and, to better understand global spatial distribution and adaptation strategies of this algae, in relation to worldwide phylogeny of the genus. Based on nuclear ITS rDNA, chloroplast rbcL gene and actin type I gene we constructed a phylogenetic tree that recovered 12 new Asterochloris lineages; and 29 Bolivian photobiont samples were assigned to 11 previously recognized Asterochloris lineages. We showed that some Asterochloris photobiont species and lineages known to date may occur in a broader spectrum of climatic conditions and mycobiont species and photobionts may show different preferences in the altitude gradient. To reveal general patterns of speci city of the mycobionts towards the photobiont in Asterochloris dependent symbiosis on global range, we tested the in uence of climate, altitude, geographical distance and effects of symbiotic partner (mycobiont) at the species level of three genera of lichen forming fungi, i.e. Stereocaulon, Cladonia and Lepraria. Also, we compared speci city of mycobionts towards Asterochloris photobionts in cosmopolitan, Neotropical, and Pantropical lichen forming fungi. Interestingly, cosmopolitan species showed the lowest speci city to their photobionts', but also the lowest haplotype diversity. While, Neotropical and Paleotropical mycobionts were more speci c.
Journal of Phycology, Feb 20, 2022
Crustose Verrucariaceae lichens form a distinctive black belt on seashores all over the world. Th... more Crustose Verrucariaceae lichens form a distinctive black belt on seashores all over the world. This lifestyle is apparently enabled by a specific set of photobionts. However, their diversity is understudied. We sampled these lichens from the northern Patagonian Pacific coast of Chile. Using molecular markers, we identified both mycobionts and photobionts. The lichens, belonging to the genus Hydropunctaria and to the Wahlenbergiella group, hosted solely Ulvophycean photobionts. Pseudendoclonium submarinum (Kornmanniaceae, Ulvales) was the most common, but representatives of other closely related, yet undescribed, lineages were also found. Undulifilum symbioticum gen. et sp. nov. is described within Kornmanniaceae based on culture morphology and DNA sequence data. Furthermore, the free‐living macroscopic genus Urospora (Acrosiphoniaceae, Ulotrichales) is reported as a lichen photobiont for the first time and is the first of its kind in the order. These results indicate that undescribed algal diversity is waiting to be uncovered in seashore lichens.
Symbiosis, Oct 22, 2020
Vegetative propagules play various important roles in lichen biology. We cultured soredia of Clad... more Vegetative propagules play various important roles in lichen biology. We cultured soredia of Cladonia lichens in vitro and obtained three noteworthy results. Firstly, soredia are a beneficial source for the isolation of lichen symbionts. The mycobiont was obtained from 66% and the photobiont from 67% of the cultured soredia that were not contaminated. Secondly, the development of soredia followed a previously recognized pattern, arachnoid stagesoredium fieldprimordium, but a thalline structure was not achieved. We suggest that thallus formation in vitro is a question of favourable environmental factors, not partners compatibility. Finally, we discovered that fungi, other than the mycobiont, as well as airborne contaminants are dispersed together with lichen soredia. This is the first-ever report of such a phenomenon. The possible ecological consequences are discussed. Cystobasidiomycete yeasts were found among these fungi. We isolated representatives of three different lineages from a single thallus suggesting a low specificity for this association.
Biodiversity and Conservation, 2016
The forest management practices used in central Europe in the last several centuries have led to ... more The forest management practices used in central Europe in the last several centuries have led to loss of lichen diversity that may be largely attributed to a loss of substrate variability and quantity. In an attempt to obtain information enabling us to mitigate this process, we surveyed affinity of lichen species to the substrates they currently occupy in six forest areas in the Czech Republic, located between 200 and 1000 m a.s.l. Tree bases and stems represented the most important substrate for lichen species, and especially so for threatened (i.e. red-listed) species. Lichen species richness per individual tree generally increased with stem diameter, especially for beech. Stems and tree bases of large-diameter beeches provide habitats that have enabled the survival of a crucial component of the red-listed lichen species in central Europe, far outweighing other tree species. The deciduous tree species that are commonly considered as favourable for lichen diversity (e.g. maples, ash, elms) were inhabited by only a few other lichen species additional to those associated with beech. This may be due to the low frequency of these tree species in most managed forests, and also some forest reserves, at the present time. Similarly, low incidence of dead wood in managed forests has likely limited its contribution to the lichen diversity, despite the high potential for lichen diversity associated with such substrates. It is Communicated by Francis Brearley.
Ecological Indicators, 2015
The Lichenologist
Cladonia luteoalba shows a specific pattern in chemical variability. Its chemotype coincides with... more Cladonia luteoalba shows a specific pattern in chemical variability. Its chemotype coincides with that of the associated Cladonia thalli. This has led to the formation of various hypotheses, but its true nature has never been clarified. We collected C. luteoalba in Central Europe and Norway. The chemotypes were detected by TLC and the mycobionts and photobionts were identified by Sanger sequencing of ITS rDNA. Mycobiont cultures were obtained and Illumina metabarcoding of the fungal ITS1 rDNA region was performed targeting minor mycobionts within the thalli. None of the methods supported C. luteoalba as a distinct Cladonia species. In phylogenetic analyses, it was placed in C. straminea and the C. coccifera agg., following the pattern in chemistry. No minor Cladonia were detected by metabarcoding or cultivation. Thus, C. luteoalba remains enigmatic as our data did not support its distinction as a separate Cladonia species.
River gravel bars are dynamic and heterogeneous habitats standing on transition between aquatic a... more River gravel bars are dynamic and heterogeneous habitats standing on transition between aquatic and terrestrial environment. Periodical flooding, low nutrient content, frost, missing safe sites, drought, and heat on the ground surface significantly influence life in these habitats. Mutualistic symbiosis may be a successful strategy for organisms to survive and to proliferate under harsh conditions. The lichen genus Stereocaulon was selected as a model symbiotic system among the organisms living on river gravel bars. The aim of our work was to determine effect of this dynamic environment on a phycobiont (i.e., green eukaryotic photobiont) community structure. We analysed 147 Stereocaulon specimens collected in the Swiss Alps using Sanger sequencing (fungal ITS rDNA, algal ITS rDNA, algal actin type I gene) and 8 selected thalli and 12 soil samples using Illumina metabarcoding (ITS2 rDNA). We performed phytosociological sampling on each study plot (n=13). Our analyses of communities o...
Fungal Ecology, 2014
Epiphytic lichens are commonly found with various grazing marks. These are however unequally dist... more Epiphytic lichens are commonly found with various grazing marks. These are however unequally distributed among species. The extent of the damage caused might be related to lichen secondary metabolites. In the present study we demonstrate that the secondary metabolites of six common epiphytic Parmeliaceae species deter grazing of tree-climbing gastropods in a series of laboratory experiments. We also show that the acetone-rinsing method itself does not affect the palatability of lichens. Subsequently, in a transplantation choice experiment, we show that the genus Melanohalea, which does not contain any lichen substances, is strongly preferred. No significant preferences between Parmelia sulcata and Melanelixia glabratula, species containing different secondary compounds, were found in the experiment. Furthermore, the grazing pressure was shown to be intensive in beech forests of the Central Europe for the first time. Thus, ecological and evolutionary consequences of lichenivory should be considered.
Frontiers in Microbiology, 2022
Climatic factors, soil chemistry and geography are considered as major factors affecting lichen d... more Climatic factors, soil chemistry and geography are considered as major factors affecting lichen distribution and diversity. To determine how these factors limit or support the associations between the symbiotic partners, we revise the lichen symbiosis as a network of relationships here. More than one thousand thalli of terricolous Cladonia lichens were collected at sites with a wide range of soil chemical properties from seven biogeographical regions of Europe. A total of 18 OTUs of the algal genus Asterochloris and 181 OTUs of Cladonia mycobiont were identified. We displayed all realized pairwise mycobiont–photobiont relationships and performed modularity analysis. It revealed four virtually separated modules of cooperating OTUs. The modules differed in mean annual temperature, isothermality, precipitation, evapotranspiration, soil pH, nitrogen, and carbon contents. Photobiont switching was strictly limited to algae from one module, i.e., algae of similar ecological preferences, an...
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Papers by Ivana Cernajova