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Rosmarie Honegger - One of the best experts on this subject based on the ideXlab platform.
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Green-algal photobiont diversity (Trebouxia spp.) in representatives of Teloschistaceae (Lecanoromycetes, lichen-forming ascomycetes)
Lichenologist, 2014Co-Authors: Shyam Nyati, Sandra Scherrer, Silke Werth, Rosmarie HoneggerAbstract:The green algal photobionts of 12 Xanthoria, seven Xanthomendoza, two Teloschistes species and Josefpoeltia parva (all Teloschistaceae) were analyzed. Xanthoria parietina was sampled on four continents. More than 300 photobiont isolates were brought into sterile culture. The nuclear ribosomal internal transcribed spacer region (nrITS; 101 sequences) and the large subunit of the RuBiSco gene (rbcL; 54 sequences) of either whole lichen DNA or photobiont isolates were phylogenetically analyzed. ITS and rbcL phylogenies were congruent, although some subclades had low bootstrap support. Trebouxia arboricola, T. decolorans and closely related, unnamed Trebouxia species, all belonging to clade A, were found as photobionts of Xanthoria species. Xanthomendoza species associated with either T. decolorans (clade A), T. impressa, T. gelatinosa (clade I) or with an unnamed Trebouxia species. Trebouxia gelatinosa genotypes (clade I) were the photobionts of Teloschistes chrysophthalmus, T. hosseusianus and Josefpoeltia parva. Only weak correlations between distribution patterns of algal genotypes and environmental conditions or geographical location were observed.
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Phylogenetic analysis of LSU and SSU rDNA group I introns of lichen photobionts associated with the genera Xanthoria and Xanthomendoza (Teloschistaceae, lichenized Ascomycetes)
Journal of phycology, 2013Co-Authors: Shyam Nyati, Silke Werth, Debashish Bhattacharya, Rosmarie HoneggerAbstract:We studied group I introns in sterile cultures of selected groups of lichen photobionts, focusing on Trebouxia species associated with Xanthoria s. lat. (including Xanthomendoza spp.; lichen-forming ascomycetes). Group I introns were found inserted after position 798 (Escherichia coli numbering) in the large subunit (LSU) rRNA in representatives of the green algal genera Trebouxia and Asterochloris. The 798 intron was found in about 25% of Xanthoria photobionts including several reference strains obtained from algal culture collections. An alignment of LSU-encoded rDNA intron sequences revealed high similarity of these sequences allowing their phylogenetic analysis. The 798 group I intron phylogeny was largely congruent with a phylogeny of the Internal Transcribed Spacer Region (ITS), indicating that the insertion of the intron most likely occurred in the common ancestor of the genera Trebouxia and Asterochloris. The intron was vertically inherited in some taxa, but lost in others. The high sequence similarity of this intron to one found in Chlorella angustoellipsoidea suggests that the 798 intron was either present in the common ancestor of Trebouxiophyceae, or that its present distribution results from more recent horizontal transfers, followed by vertical inheritance and loss. Analysis of another group I intron shared by these photobionts at small subunit (SSU) position 1512 supports the hypothesis of repeated lateral transfers of this intron among some taxa, but loss among others. Our data confirm that the history of group I introns is characterized by repeated horizontal transfers, and suggests that some of these introns have ancient origins within Chlorophyta.
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Three new Xanthoria species from South Africa: X. hirsuta, X. inflata and X. doidgeae
The Lichenologist, 2007Co-Authors: Christof Eichenberger, André Aptroot, Rosmarie HoneggerAbstract:Abstract:Three new Xanthoria species are described from South Africa. Xanthoria hirsuta sp. nov. has hairs on the surface of the thallus and apothecia, best visible in young, growing parts. Dust particles and sand granules stick to this hairy surface, giving the thallus a somewhat dirty appearance. Xanthoria inflata sp. nov. has inflated lobes similar to a Menegazzia. It carries numerous crystals on its medullary hyphae, which are ivory-coloured in young, but intensely orange coloured in old lobes. Xanthoria doidgeae sp. nov. has relatively small lobes with pruinose margins. All three species are fertile, none of them forms symbiotic propagules.
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the impact of different long term storage conditions on the viability of lichen forming ascomycetes and their green algal photobiont trebouxia spp
Plant Biology, 2003Co-Authors: Rosmarie HoneggerAbstract:: Lichen-forming ascomycetes and their green algal photobionts completely die off within approximately 3 years of storage at room temperature. Macroscopically this is recognizable as a colour change, the green shades of the chlorophylls being lost. In fluorescent light microscopy preparations an increase in fungal autofluorescence and a significant decrease in chlorophyll autofluorescence in the Trebouxia cells was observed. In transmission electron microscopy preparations of Xanthoria parietina and its green algal photobiont, Trebouxia arboricola, the fungal membrane systems were found to be largely broken down whereas the shrivelled algal protoplast failed to rehydrate after storage at room temperature. When stored in the desiccated state at - 20 °C, both partners of the symbiosis stayed fully viable for up to 13 years, their colouration and chlorophyll fluorescence being unchanged. Viability was measured as ascospore ejection and germination rates in Xanthoria parietina, soredium germination rates in Xanthoria fallax, Hypogymnia physodes and Parmelia sulcata, and autospore formation rate in Trebouxia cells (green algal photobiont), which had been isolated from the thalli after rehydration. Thallus fragments of Xanthoria parietina were shown to grow normally after one week of storage in LN2 without any cryoprotectant. In the desiccated state deep-frozen samples can be repeatedly brought to room temperature and back to - 20 °C without any loss of viability. Cryopreservation is therefore a suitable mode of long-term storage of viable lichen thalli for experimental studies or transplant experiments.
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inter and intraspecific variation of homologous hydrophobin h1 gene sequences among Xanthoria spp lichen forming ascomycetes
New Phytologist, 2003Co-Authors: Sandra Scherrer, Rosmarie HoneggerAbstract:Summary • Inter- and intra-specific variability of the hydrophobin gene H1 was investigated in a range of Xanthoria species collected in their natural habitat. • On Southern blots the XEH1 probe (from Xanthoria ectaneoides) hybridized under standard conditions to the genomic DNA of Xanthoria calcicola, Xanthoria parietina and Xanthoria flammea. The corresponding H1 genes in these and additional species (Xanthoria turbinata, Xanthoria spp.), and ribosomal gene regions (ITS 1 and 2, 5.8S rDNA) were amplified with polymerase chain reaction, sequenced and similarities calculated. Restriction fragment length polymorphism and cleaved amplified polymorphic sequence analyses provided molecular tools for species delimitation. • Ribosomal gene data were largely in parallel with the hydrophobin H1 sequence data, the protein-coding H1 sequence being even more variable as the noncoding rDNA regions. • Very low intraspecific variation was detected in the H1 gene of X. parietina samples collected on four continents, with the highest variability occurring among Mediterranean samples. Xanthoria ectaneoides from Brittany, France, and X. calcicola appear to be coastal and inland forms of the same fungal species but differ from Sicilian X. ectaneoides. The African X. flammea and X. turbinata are related to the X. parietina cluster.
Sandra Scherrer - One of the best experts on this subject based on the ideXlab platform.
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Green-algal photobiont diversity (Trebouxia spp.) in representatives of Teloschistaceae (Lecanoromycetes, lichen-forming ascomycetes)
Lichenologist, 2014Co-Authors: Shyam Nyati, Sandra Scherrer, Silke Werth, Rosmarie HoneggerAbstract:The green algal photobionts of 12 Xanthoria, seven Xanthomendoza, two Teloschistes species and Josefpoeltia parva (all Teloschistaceae) were analyzed. Xanthoria parietina was sampled on four continents. More than 300 photobiont isolates were brought into sterile culture. The nuclear ribosomal internal transcribed spacer region (nrITS; 101 sequences) and the large subunit of the RuBiSco gene (rbcL; 54 sequences) of either whole lichen DNA or photobiont isolates were phylogenetically analyzed. ITS and rbcL phylogenies were congruent, although some subclades had low bootstrap support. Trebouxia arboricola, T. decolorans and closely related, unnamed Trebouxia species, all belonging to clade A, were found as photobionts of Xanthoria species. Xanthomendoza species associated with either T. decolorans (clade A), T. impressa, T. gelatinosa (clade I) or with an unnamed Trebouxia species. Trebouxia gelatinosa genotypes (clade I) were the photobionts of Teloschistes chrysophthalmus, T. hosseusianus and Josefpoeltia parva. Only weak correlations between distribution patterns of algal genotypes and environmental conditions or geographical location were observed.
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inter and intraspecific variation of homologous hydrophobin h1 gene sequences among Xanthoria spp lichen forming ascomycetes
New Phytologist, 2003Co-Authors: Sandra Scherrer, Rosmarie HoneggerAbstract:Summary • Inter- and intra-specific variability of the hydrophobin gene H1 was investigated in a range of Xanthoria species collected in their natural habitat. • On Southern blots the XEH1 probe (from Xanthoria ectaneoides) hybridized under standard conditions to the genomic DNA of Xanthoria calcicola, Xanthoria parietina and Xanthoria flammea. The corresponding H1 genes in these and additional species (Xanthoria turbinata, Xanthoria spp.), and ribosomal gene regions (ITS 1 and 2, 5.8S rDNA) were amplified with polymerase chain reaction, sequenced and similarities calculated. Restriction fragment length polymorphism and cleaved amplified polymorphic sequence analyses provided molecular tools for species delimitation. • Ribosomal gene data were largely in parallel with the hydrophobin H1 sequence data, the protein-coding H1 sequence being even more variable as the noncoding rDNA regions. • Very low intraspecific variation was detected in the H1 gene of X. parietina samples collected on four continents, with the highest variability occurring among Mediterranean samples. Xanthoria ectaneoides from Brittany, France, and X. calcicola appear to be coastal and inland forms of the same fungal species but differ from Sicilian X. ectaneoides. The African X. flammea and X. turbinata are related to the X. parietina cluster.
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Inter‐ and intraspecific variation of homologous hydrophobin (H1) gene sequences among Xanthoria spp. (lichen‐forming ascomycetes)
New Phytologist, 2003Co-Authors: Sandra Scherrer, Rosmarie HoneggerAbstract:Summary • Inter- and intra-specific variability of the hydrophobin gene H1 was investigated in a range of Xanthoria species collected in their natural habitat. • On Southern blots the XEH1 probe (from Xanthoria ectaneoides) hybridized under standard conditions to the genomic DNA of Xanthoria calcicola, Xanthoria parietina and Xanthoria flammea. The corresponding H1 genes in these and additional species (Xanthoria turbinata, Xanthoria spp.), and ribosomal gene regions (ITS 1 and 2, 5.8S rDNA) were amplified with polymerase chain reaction, sequenced and similarities calculated. Restriction fragment length polymorphism and cleaved amplified polymorphic sequence analyses provided molecular tools for species delimitation. • Ribosomal gene data were largely in parallel with the hydrophobin H1 sequence data, the protein-coding H1 sequence being even more variable as the noncoding rDNA regions. • Very low intraspecific variation was detected in the H1 gene of X. parietina samples collected on four continents, with the highest variability occurring among Mediterranean samples. Xanthoria ectaneoides from Brittany, France, and X. calcicola appear to be coastal and inland forms of the same fungal species but differ from Sicilian X. ectaneoides. The African X. flammea and X. turbinata are related to the X. parietina cluster.
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Characterization and expression of XPH1, the hydrophobin gene of the lichen-forming ascomycete Xanthoria parietina
New Phytologist, 2002Co-Authors: Sandra Scherrer, Annette Haisch, Rosmarie HoneggerAbstract:Summary • Molecular genetics of wall surface hydrophobicity of the lichen-forming ascomycete Xanthoria parietina was explored. In a previous study XPH11, a class 1 hydrophobin, was isolated from the symbiotic phenotype collected in nature. • A genomic library of aposymbiotically cultured Xanthoria parietina was constructed and screened for the hydrophobin gene XPH1. Gene expression was explored with in situ hybridization techniques. • The encoded protein contained 110 amino acids, including a secretion signal; the open reading frame was interrupted by two introns. XPH1 was differentially expressed in the symbiotic phenotype, high expression being evident in medullary hyphae of the vegetative thallus and of the thalline margin of apothecia; these are in contact with the algal layer and prevent the thalline interior from becoming waterlogged, a prerequisite for gas exchange of the photobiont. No signal was detected in either the hydrophilic cortex, the conidiomata, the hymenial and subhymenial layers of apothecia, or in the aposymbiotically cultured mycobiont. The data for Northern blot analyses correlated with those of in situ hybridization studies. • XPH1 may fulfil important roles for the functioning of the symbiotic relationship.
Francois Lutzoni - One of the best experts on this subject based on the ideXlab platform.
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molecular phylogenetic study at the generic boundary between the lichen forming fungi caloplaca and Xanthoria ascomycota teloschistaceae
Fungal Biology, 2003Co-Authors: Ulrik Søchting, Francois LutzoniAbstract:A molecular phylogenetic analysis of rDNA was performed for seven Caloplaca, seven Xanthoria, one Fulgensia and five outgroup species. Phylogenetic hypotheses are constructed based on nuclear small and large subunit rDNA, separately and in combination. Three strongly supported major monophyletic groups were revealed within the Teloschistaceae. One group represents the Xanthoria fallax-group. The second group includes three subgroups: (1) X. parietina and X. elegans; (2) basal placodioid Caloplaca species followed by speciations leading to X. polycarpa and X. candelaria; and (3) a mixture of placodioid and endolithic Caloplaca species. The third main monophyletic group represents a heterogeneous assemblage of Caloplaca and Fulgensia species with a drastically different metabolite content. We report here that the two genera Caloplaca and Xanthoria, as well as the subgenus Gasparrinia, are all polyphyletic. The taxonomic significance of thallus morphology in Teloschistaceae and the current delimitation of the genus Xanthoria is discussed in light of these results.
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phylogenetic study of fulgensia and allied caloplaca and Xanthoria species teloschistaceae lichen forming ascomycota
American Journal of Botany, 2003Co-Authors: Ester Gaya, Stefan Zoller, Francois Lutzoni, P NavarrorosinesAbstract:Fulgensia Massal. & De Not. is a widespread genus with considerable morphological and ecological heterogeneity across species. For this reason, the taxonomic delimitation of this genus has been controversial. Relationships among species of Fulgensia, Caloplaca Th. Fr., and Xanthoria (Fr.) Th. Fr. (Lecanorales) were investigated based on a comprehensive phylogenetic analysis of 62 DNA sequences from the nuclear ribosomal internal transcribed spacer (ITS) region using maximum parsimony (MP) and likelihood (ML). Ambiguously aligned (INAASE coded characters) and unambiguous regions were analyzed separately and combined when using MP as the optimization criterion. All our analyses confirm the polyphyly of this genus as three distinct lineages: Fulgensia sensu stricto, F. australis, and F. schistidii. We report here that Caloplaca, Fulgensia, and Xanthoria together form two main sister lineages. One lineage includes Fulgensia schistidii (part of the C. saxicola group), Xanthoria, and most of the lobed Caloplaca species belonging to the Gasparrinia group. A second main lineage comprises the remaining Caloplaca species, Fulgensia sensu stricto, and F. australis. Therefore, the traditional generic level classification schemes for the family Teloschistaceae appear to be highly artificial. All three genera were found to be nonmonophyletic. We demonstrate here that the ITS is appropriate to resolve relationships across the Teloschistaceae. However, a combination of an MP analysis, in which ambiguously aligned regions are accommodated using INAASE, with an ML analysis, in which phylogenetic confidence is estimated using a Bayesian approach, is needed.
P Navarrorosines - One of the best experts on this subject based on the ideXlab platform.
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phylogenetic study of fulgensia and allied caloplaca and Xanthoria species teloschistaceae lichen forming ascomycota
American Journal of Botany, 2003Co-Authors: Ester Gaya, Stefan Zoller, Francois Lutzoni, P NavarrorosinesAbstract:Fulgensia Massal. & De Not. is a widespread genus with considerable morphological and ecological heterogeneity across species. For this reason, the taxonomic delimitation of this genus has been controversial. Relationships among species of Fulgensia, Caloplaca Th. Fr., and Xanthoria (Fr.) Th. Fr. (Lecanorales) were investigated based on a comprehensive phylogenetic analysis of 62 DNA sequences from the nuclear ribosomal internal transcribed spacer (ITS) region using maximum parsimony (MP) and likelihood (ML). Ambiguously aligned (INAASE coded characters) and unambiguous regions were analyzed separately and combined when using MP as the optimization criterion. All our analyses confirm the polyphyly of this genus as three distinct lineages: Fulgensia sensu stricto, F. australis, and F. schistidii. We report here that Caloplaca, Fulgensia, and Xanthoria together form two main sister lineages. One lineage includes Fulgensia schistidii (part of the C. saxicola group), Xanthoria, and most of the lobed Caloplaca species belonging to the Gasparrinia group. A second main lineage comprises the remaining Caloplaca species, Fulgensia sensu stricto, and F. australis. Therefore, the traditional generic level classification schemes for the family Teloschistaceae appear to be highly artificial. All three genera were found to be nonmonophyletic. We demonstrate here that the ITS is appropriate to resolve relationships across the Teloschistaceae. However, a combination of an MP analysis, in which ambiguously aligned regions are accommodated using INAASE, with an ML analysis, in which phylogenetic confidence is estimated using a Bayesian approach, is needed.
Josef Hafellner - One of the best experts on this subject based on the ideXlab platform.
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arthonia parietinaria a common but frequently misunderstood lichenicolous fungus on species of the Xanthoria parietina group
Fungal Biology, 2016Co-Authors: Antonia Fleischhacker, Andreas Frisch, Walter Obermayer, Martin Grube, Josef HafellnerAbstract:Arthonia parietinaria is described as new to science. Host of the type and at the same time the only confirmed host species is the foliose macrolichen Xanthoria parietina. Sequence data of nucLSU rRNA genes reveal a close relationship to Arthonia molendoi. A. parietinaria is recorded for many countries in Europe, western Asia, and northern Africa.
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Arthonia parietinaria – A common but frequently misunderstood lichenicolous fungus on species of the Xanthoria parietina-group
Fungal Biology, 2016Co-Authors: Antonia Fleischhacker, Andreas Frisch, Walter Obermayer, Martin Grube, Josef HafellnerAbstract:Arthonia parietinaria is described as new to science. Host of the type and at the same time the only confirmed host species is the foliose macrolichen Xanthoria parietina. Sequence data of nucLSU rRNA genes reveal a close relationship to Arthonia molendoi. A. parietinaria is recorded for many countries in Europe, western Asia, and northern Africa.
