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Backor M.,University of P.J. Safarik | Peksa O.,The West Bohemian Museum in Pilsen | Peksa O.,Charles University | Skaloud P.,Charles University | Backorova M.,Safarik University
Ecotoxicology and Environmental Safety | Year: 2010

The photobiont is considered as the more sensitive partner of lichen symbiosis in metal pollution. For this reason the presence of a metal tolerant photobiont in lichens may be a key factor of ecological success of lichens growing on metal polluted substrata. The photobiont inventory was examined for terricolous lichen community growing in Cu mine-spoil heaps derived by historical mining.Sequences of internal transcribed spacer (ITS) were phylogenetically analyzed using maximum likelihood analyses. A total of 50 ITS algal sequences were obtained from 22 selected lichen taxa collected at three Cu mine-spoil heaps and two control localities. Algae associated with Cladonia and Stereocaulon were identified as members of several Asterochloris lineages, photobionts of cetrarioid lichens clustered with Trebouxia hypogymniae ined.We did not find close relationship between heavy metal content (in localities as well as lichen thalli) and photobiont diversity. Presence of multiple algal genotypes in single lichen thallus has been confirmed. © 2009 Elsevier Inc. Source


Svoboda D.,Charles University | Peksa O.,The West Bohemian Museum in Pilsen | Vesela J.,Charles University
Environmental Pollution | Year: 2010

We investigated lichen diversity in temperate oak forests using standardized protocols. Forty-eight sites were sampled in the Czech Republic, Slovakia and Hungary. The effects of natural environmental predictors and human influences on lichen diversity (lichen diversity value, species richness) were analysed by means of correlation tests. We found that lichen diversity responded differently to environmental predictors between two regions with different human impact. In the industrial region, air pollution was the strongest factor. In the agricultural to highly forested regions, lichen diversity was strongly influenced by forest age and forest fragmentation. We found that several natural factors can in some cases obscure the effect of human influences. Thus, factors of naturality gradient must be considered (both statistically and interpretively) when studying human impact on lichen diversity. © 2009 Elsevier Ltd. All rights reserved. Source


Petrzik K.,Academy of Sciences of the Czech Republic | Vondrak J.,Academy of Sciences of the Czech Republic | Bartak M.,Masaryk University | Peksa O.,The West Bohemian Museum in Pilsen | Kubesova O.,Academy of Sciences of the Czech Republic
European Journal of Plant Pathology | Year: 2014

Lichens are symbiotic associations of fungi with green algae or cyanobacteria. They have arisen independently several times within the Ascomycota and Basidiomycota. This symbiosis became with time one of the most successful life forms on Earth. Outside of the symbiotic algae and fungi, there are endophytic fungi, other algae, and lichen-associated bacteria present within lichen thalli. Till now, no lichen-specific pathogens have been reported among bacteria and viruses. Around 15 dsRNA viruses are known from Eurotiomycetes and another dsRNA and reverse transcribed ssRNA viruses from Dothideomycetes containing some lichenized fungal lineages. Algal viruses have been identified from less than 1 % of known eukaryotic algal species but no virus has been found in Trebouxia or in Trentepohlia (Chlorophyta, Pleurastrophyceae, Pleurastrales), the most common green lichen photobionts. On the other hand, dsDNA viruses infecting related Chlorella algae are well known from freshwater phytoplankton. However, high-molecular weight dsRNA isolated from different lichen thalli indicated to us presence of ss or dsRNA viruses. A PCR-based search for viruses with genus-specific and species-specific primers resulted in amplification of genome segments highly identical with those of plant cytorhabdoviruses and with Apple mosaic virus (ApMV). The nucleotide sequence of the putative lichen cytorhabdovirus showed high identity (98 %) with Ivy latent cytorhabdovirus. The nucleotide sequences of six Apple mosaic virus isolates from lichens showed high similarity with ApMV isolates from apple and pear hosts. The lichen ApMV isolates were mechanically transmitted to an herbaceous host and detected positive in ELISA 14 days thereafter, which support its infectivity on plants. We prepared axenic cultures of photobionts identified as Trebouxia sp. from this ApMV-positive lichen samples. All these cultures were positive for ApMV in RT-PCR test. We suggest that lichens as a whole (or their photobionts, more specifically) could serve as reservoirs for viruses, despite the fact that the way of transmission between different organisms is not clear. We showed that lichens could harbour several viruses simultaneously, as the plant cytorhabdovirus and ApMV were detected in the same host, also. © 2013 KNPV. Source


Vancurova L.,Charles University | Peksa O.,The West Bohemian Museum in Pilsen | Nemcova Y.,Charles University | Skaloud P.,Charles University
Phytotaxa | Year: 2015

This paper describes a new genus of lichen photobionts, Vulcanochloris, with three newly proposed species, V. canariensis, V. guanchorum and V. symbiotica. These algae have been discovered as photobionts of lichen Stereocaulon vesuvianum growing on slopes of volcanos and lava fields on La Palma, Canary Islands, Spain. Particular species, as well as the newly proposed genus, are delimited based on ITS rDNA, 18S rDNA and rbcL sequences, chloroplast morphology, and ultra structural features. Phylogenetic analyses infer the genus Vulcanochloris as a member of Trebouxiophycean order Trebouxiales, in a sister relationship with the genus Asterochloris. Our data point to the similar lifestyle and morphology of these two genera; however, Vulcanochloris can be well distinguished by a unique formation of spherical incisions within the pyrenoid. My cobiont specificity and geographical distribution of the newly proposed genus is further discussed. © 2015 Magnolia Press. Source


Skaloud P.,Charles University | Steinova J.,Charles University | Ridka T.,Charles University | Vancurova L.,Charles University | Peksa O.,The West Bohemian Museum in Pilsen
Journal of Phycology | Year: 2015

The genus Asterochloris represents one of the most common, widespread, and diverse taxa of lichen photobionts. In this report, we describe and characterize six new species (A. echinata, A. friedlii, A. gaertneri, A. leprarii, A. lobophora, and A. woessiae) that were identified during our recent investigation of photobiont diversity. We found that the species differed genetically, morphologically, ecologically, and with respect to their mycobiont partners. Statistical analyses revealed significant morphological differentiation of all six newly described species, as well as their separation from previously described Asterochloris species. Chloroplast morphology represented the best morphological marker for species delineation. In fact, each species can be recognized by the dominance and unique assemblage of particular chloroplast types. Although genetically well recognized by rapidly evolving internal transcribed spacer rDNA and actin intron markers, all 13 investigated Asterochloris species shared identical small subunit rDNA sequences. We therefore demonstrated that morphologically and ecologically diverse species can frequently be grouped into a single taxonomic unit in whole-transcriptome sequencing studies, considerably affecting the resulting estimates of species diversity. Finally, we demonstrated the presence of isogamous sexual reproduction in Asterochloris, disputing the current symbiotic dogma of the loss of sexual reproduction in algal symbionts. © 2015 Phycological Society of America. Source

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