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.
Phylogenetic analyses using mtSSU and nuITS sequences of Buellia violaceofusca (previously placed in Lecanoromycetes), a sterile, sorediate lichen having a trebouxioid photobiont, surprisingly prove ...that the species is conspecific with Lecanographa amylacea (Arthoniomycetes), a fertile, esorediate species with a trentepohlioid photobiont. These results suggest that L. amylacea and B. violaceofusca are photomorphs of the same mycobiont species, which, depending on the photobiont type, changes the morphology and the reproduction strategy. This is the first example of a lichenized fungus that can select between Trebouxia (Trebouxiophyceae) and trentepohlioid (Ulvophyceae) photobionts. Trebouxia photobionts from the sorediate morphotype belong to at least three different phylogenetic clades, and the results suggest that Lecanographa amylacea can capture the photobiont of other lichens such as Chrysothrix candelaris to form the sorediate morphotype. Phylogenetic analyses based on rbcL DNA data suggest that the trentepohlioid photobiont of L. amylacea is closely related to Trentepohlia isolated from fruticose lichens. The flexibility in the photobiont choice enables L. amylacea to use a larger range of tree hosts. This strategy helps the lichen to withstand changes of environmental conditions, to widen its distribution range and to increase its population size, which is particularly important for the survival of this rare species.
Derivatives of usnic acid (UA), a secondary metabolite from lichens, were synthesized to improve its anticancer activity and selectivity. Recently we reported the synthesis and activity of an UA ...isoxazole derivative, named
, against cancer cells of different origins. Herein, the molecular mechanisms underlying its activity and efficacy in vivo were tested. The viability of breast cancer or normal cells has been tested using an MTT assay. Cell and organelle morphology was analyzed using light, electron and fluorescence microscopy. Gene expression was evaluated by RNAseq and protein levels were evaluated by Western blotting. In vivo anticancer activity was evaluated in a mice xenograft model. We found that
induced massive vacuolization which originated from the endoplasmic reticulum (ER). ER stress markers were upregulated both at the mRNA and protein levels. ER stress was caused by the release of Ca
ions from the ER by IP3R channels which was mediated, at least partly, by phospholipase C (PLC)-synthetized 1,4,5-inositol triphosphate (IP3). ER stress led to cell death with features of apoptosis and paraptosis. When applied to nude mice with xenografted breast cancer cells,
stopped tumour growth. In mice treated with
, vacuolization was observed in tumour cells, but not in other organs. This study shows that the antiproliferative activity of
relates to the induction of ER stress in cancer, not in healthy, cells and it leads to breast cancer cell death in vitro and in vivo.
In the past few years, new phylogenetic lineages in
were detected as a result of molecular approaches. These studies included symbiont selectivity in lichen communities, transects along altitudinal ...gradients at local and global scales and the photobiont diversity in local populations of lichen-forming fungal species. In most of these studies, phylogenetic and haplotype analyses based on the internal transcribed spacer (ITS) locus have continuously allowed the recognition of new monophyletic lineages, which suggests that still numerous undiscovered
lineages can be hidden in lichens from unexplored areas, especially in the tropics. Here, we estimated the biodiversity of photobionts in Bolivian Andean vegetation and assessed their specificity. About 403 lichen samples representing 42 genera, e.g.,
,
,
,
,
,
,
,
,
, and
, containing
photobionts, were analyzed. ITS ribosomal DNA (rDNA) and
L markers were used. We obtained
sequences from Bolivian samples belonging to already described clades A, C, I, and S. Thirty-nine
lineages were distinguished within these clades, while 16 were new. To reveal the structure of the community of Bolivian photobionts and their relationships with mycobionts, the comparative effects of climate, altitude, geographical distances, substrate, and habitat type, as well as functional traits of lichens such as growth forms, propagation mode and secondary metabolites, were analyzed. Furthermore, new Bolivian records were included in analysis on a global scale. In our study, the mycobiont genus or even species are the most important factors correlated with photobiont identity. Moreover, we revealed that the community of Bolivian photobionts is shaped by altitude.
Infraspecific variation of the ITS rDNA region of some brown
occurring in Poland is studied and compared with non-molecular characters. Haplotype networks are used to illustrate the variability ...within the species. Both newly-produced sequences from Central Europe and from all over the world, downloaded from the GenBank, are used. The number of haplotypes found for each taxon ranged from five in
to 12 in
and
; however, their numbers correlate with the number of specimens tested. New haplotypes for
,
and
are found. Based on our 169-sample dataset, we could not infer any geographical correlation, either locally or world-wide. Many of the analysed haplotypes were widely distributed and the same haplotype was often shared between temperate and polar populations. A comparison of molecular, morphological, anatomical and chemical characters also shows no correlation.
Lichens are fungi (mycobionts) that form symbiotic associations with photoautotrophic prokaryotes or eukaryotes (photobionts); however, some species can exchange photosynthetic partners during their ...lifecycles. This phenomenon modifies the morphology of lichens and consequently influences the taxonomy of lichenized fungi. Here, a few such cases in which the photobionts influenced the taxonomy and systematics of lichenized fungi are reviewed. Two different morphotypes of the same species – known as photomorphs – were classified as different species and sometimes different genera. Moreover, different types of photobionts and the absence or presence (optional lichenization) of an alga in the thallus were believed to be diagnostic characters for discriminating genera. However, the taxonomy and systematics of lichens are based always, according to Article F.1.1. of the International Code of Nomenclature for Algae, Fungi, and Plants, on the fungal partner and only one name is applied.
is a genus of crustose lichens containing 13 accepted species that can be separated into two groups, based on differences in secondary chemistry that correlate with differences in characters of the ...sexual reproductive structures (asci and ascospores). Molecular phylogenetic analyses recovered these groups as monophyletic and support their recognition as distinct genera that differ in phenotypic characters. Species containing 2'-
-methylperlatolic acid are transferred to the new genus,
Guzow-Krzem., Kukwa & Lendemer and four new combinations are proposed:
(Lendemer) Guzow-Krzem., Kukwa & Lendemer,
(Lendemer) Guzow-Krzem., Kukwa & Lendemer,
(Guzow-Krzem., Łubek, Kubiak & Kukwa) Guzow-Krzem., Kukwa & Lendemer and
(Lumbsch, A.W. Archer & Elix) Guzow-Krzem., Kukwa & Lendemer. The remaining species produce thamnolic acid and represent
s.str. Haplotype analyses recovered sequences of
in two distinct groups, one corresponding to
s.str. and one to
, the latter being resurrected from synonymy of
and, thus, requiring the combination,
(Erichsen) Ptach-Styn, Guzow-Krzem., Tønsberg & Kukwa. Sequences of
were found to be intermixed within the otherwise monophyletic
s.str. These two taxa, which differ in contrasting reproductive mode and overall geographic distributions, are maintained as distinct, pending further studies with additional molecular loci. Lectotypes are selected for
,
and P.chloropoliaf.cana. The latter is a synonym of
. New primers for the amplification of mtSSU are also presented.
The new genus
Pseudolepraria
Kukwa, Jabłońska, Kosecka & Guzow-Krzemińska is introduced to accommodate
Lepraria stephaniana
Elix, Flakus & Kukwa. Phylogenetic analyses of nucITS, nucLSU, mtSSU and ...RPB2 markers recovered the new genus in the family Ramalinaceae with strong support. The genus is characterised by its thick, unstratified thallus composed entirely of soredia-like granules, the presence of 4-
O
-methylleprolomin, salazinic acid, zeorin and unknown terpenoid, and its phylogenetic position. The new combination,
P. stephaniana
(Elix, Flakus & Kukwa) Kukwa, Jabłońska, Kosecka & Guzow-Krzemińska, is proposed.
The main aims of this work were to assess phylogenetic relationships of the trentepohlialean photobionts in tropical, mainly sterile, lichens collected in Bolivia, to examine their genetic diversity, ...host specificity, and the impact of habitat factors on the occurrence of Trentepohliales. Based on rbcL marker analysis, we constructed a phylogenetic tree with eight major clades of Trentepohliales, of which seven free‐living species are intermingled with lichenized ones. Our analyses show that the studied photobionts are scattered across the phylogenetic tree and algae from temperate and tropical regions do not form monophyletic groups, except within one clade that seems to be restricted to the tropics. There is no significant occurrence pattern of lichenized Trentepohliaceae on a specific substratum, except Cephaleuros spp. and Phycopeltis spp., which are restricted to leaves, while some clades with lichenized algae may be specialized to tree bark and wood. Moreover, we found two patterns of associations: first, closely related algae can associate with distantly related mycobionts; second, some other trentepohlioid algae associate with selected lineages of fungi (e.g., Arthoniaceae or Graphidaceae). We also found that some lineages of photobionts are even more selective and associate exclusively with one species (e.g., Dichosporidium nigrocinctum, Diorygma antillarum) or closely related lichen‐forming fungi (Herpothallon spp.). Concluding, we found that occurrence of some trentepohlialean photobionts may correlate with the particular type of the mycobiont.
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