The structure, function, and molecular mechanisms of lichen survival in harsh habitats like Antarctica and Alpine localities, where environmental extremes change frequently, are highly interesting yet largely underexplored. We used high resolution microscopy, Raman spectroscopy, and chlorophyll a fluorescence to investigate the basic structure and function, i.e., intrathalline distribution and allocation of photobionts, as well as the heat dissipation process in three Antarctic lichens: Dermatocarpon polyphyllizum (DP), Umbilicaria antarctica (UA), and Leptogium puberulum (LP). Microscopic images of their transverse slices revealed visual insights into the heterogeneous distribution of photobionts within their structurally distinct thalli. Raman spectra showed shifts in the carotenoid Raman ν1(CC) band between lichens with algal (DP and UA) and cyanobacterial (LP) photobionts, and interestingly, they revealed biosynthesis of scytonemin, a UV-screening pigment, in cyanolichen LP. We found that increasing actinic irradiance has a nearly equal effect on the shape of chlorophyll fluorescence transients also during dark relaxation in lichens with algal photobionts, but it differed greatly for cyanolichen LP. The dark relaxation kinetics of non-photochemical quenching (NPQ) in experimental lichens differed significantly between lichens with algal photobionts DP and UA; however, this parameter could not be calculated in cyanolichen LP. The components of NPQ revealed that rapidly relaxing energy dependent quenching, ΦqE, is active and protects the thallus of DP predominantly; however, in UA state transition quenching, ΦqT, predominates. The diversity in NPQ across the three examined lichens revealed intriguing aspects of heat dissipation in their photobionts as a mechanism for survival under Antarctica conditions.
- Klíčová slova
- Carotenoids, Chlorophyll a fluorescence transient, High resolution microscopy, Optical signal, Raman spectra, Scytonemin,
- MeSH
- chlorofyl a * metabolismus MeSH
- chlorofyl * metabolismus analýza MeSH
- lišejníky * metabolismus chemie fyziologie MeSH
- Ramanova spektroskopie * MeSH
- sinice metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Antarktida MeSH
- Názvy látek
- chlorofyl a * MeSH
- chlorofyl * MeSH
The analysis of the interaction between main bionts (mycobiont and photobiont) in the lichen symbiosis delivers substantial information about their preferences in the selection of symbiotic partners, and their ecological preferences. The selectivity in the Parmelia genus has been defined as strong so far. However, data on this lichen genus, which includes several widely distributed species, are biogeographically limited. Therefore, using specialization indicators and extended sampling, in this study, we estimated the interactions between the main bionts of selected Parmelia spp., using two levels of estimation (species/OTU and haplotype). A comparison of mycobiont-photobiont interactions at different levels showed that considering only mycobiont species and Trebouxia OTUs, greater specialization is found, while Parmelia species studied in this work present a more generalistic strategy in photobiont choice when haplotypes are considered. Despite the uneven sampling of Parmelia species, the interpretation of specialization within species and individuals of the genus leads to a more precise and accurate interpretation of their adaptation strategies. Furthermore, the data from P. sulcata indicate the existence of a different pool of compatible haplotypes in some geographical regions compared to neighboring areas. This observation suggests the potential influence of climatic factors.
- Klíčová slova
- Adaptation strategies, Lichen symbiosis, Mycobiont, Photobiont, Specialization,
- MeSH
- fylogeneze MeSH
- haplotypy * MeSH
- lišejníky * genetika mikrobiologie fyziologie MeSH
- symbióza * genetika MeSH
- terčovkovité genetika MeSH
- Publikační typ
- časopisecké články MeSH
Mutualistic symbioses have contributed to major transitions in the evolution of life. Here, we investigate the evolutionary history and the molecular innovations at the origin of lichens, which are a symbiosis established between fungi and green algae or cyanobacteria. We de novo sequence the genomes or transcriptomes of 12 lichen algal symbiont (LAS) and closely related non-symbiotic algae (NSA) to improve the genomic coverage of Chlorophyte algae. We then perform ancestral state reconstruction and comparative phylogenomics. We identify at least three independent gains of the ability to engage in the lichen symbiosis, one in Trebouxiophyceae and two in Ulvophyceae, confirming the convergent evolution of the lichen symbioses. A carbohydrate-active enzyme from the glycoside hydrolase 8 (GH8) family was identified as a top candidate for the molecular-mechanism underlying lichen symbiosis in Trebouxiophyceae. This GH8 was acquired in lichenizing Trebouxiophyceae by horizontal gene transfer, concomitantly with the ability to associate with lichens fungal symbionts (LFS) and is able to degrade polysaccharides found in the cell wall of LFS. These findings indicate that a combination of gene family expansion and horizontal gene transfer provided the basis for lichenization to evolve in chlorophyte algae.
- MeSH
- biologická evoluce MeSH
- Chlorophyta * genetika MeSH
- fylogeneze * MeSH
- genomika MeSH
- glykosidhydrolasy genetika metabolismus MeSH
- lišejníky * genetika mikrobiologie MeSH
- molekulární evoluce MeSH
- přenos genů horizontální MeSH
- symbióza * genetika MeSH
- transkriptom MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- glykosidhydrolasy MeSH
This study explores and compares the limits for photosynthesis in subzero temperatures of six Antarctic lichens: Sphaerophorus globosus, Caloplaca regalis, Umbilicaria antarctica, Pseudephebe minuscula, Parmelia saxatilis and Lecania brialmontii combining linear cooling and chlorophyll fluorescence methods. The results revealed triphasic S-curves in the temperature response of the maximum quantum yield (FV/FM) and effective quantum yield of photosystem II (ΦPSII) for all species. All investigated species showed a high level of cryoresistance with critical temperatures (Tc) below -20 °C. However, record low Tc temperatures have been discovered for L. brialmotii (-54 °C for FV/FM and -40 °C for ΦPSII) and C. regalis (-52 °C for FV/FM and -38 °C for ΦPSII). Additionally, the yield differentials (FV/FM - ΦPSII) in functions of temperature revealed one or two peaks, with the larger one occurring for temperatures below -20 °C for the above-mentioned species. Finally, Kautsky kinetics were measured and compared at different temperatures (20 °C, 10 °C, 0 °C and -10 °C and then -10 °C after 1 h of incubation). This research serves as a foundation for further developing investigations into the biophysical mechanisms by which photosynthesis is carried out at subzero temperatures.
- Klíčová slova
- Antarctic lichens, Chlorophyll fluorescence, Freezing tolerance, Kautsky kinetic, Linear cooling, Photosynthesis,
- MeSH
- chlorofyl * MeSH
- fluorescence MeSH
- fotosyntéza MeSH
- fotosystém II - proteinový komplex MeSH
- lišejníky * fyziologie MeSH
- teplota MeSH
- zmrazování MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- chlorofyl * MeSH
- fotosystém II - proteinový komplex MeSH
The accumulation of 55 elements in lichens under the heap of a former nickel smelter (village Dolná Streda, Slovakia) and at eight sites at different distances from the heap plus six sites throughout Slovakia was studied to determine the elemental profile. The major metals in the heap sludge and in the lichens below the heap (Ni, Cr, Fe, Mn, and Co) were surprisingly low in lichens from both the near and far vicinity of the heap (4-25 km), indicating limited airborne spread. However, two different sites with metallurgical activity (another site near the ferroalloy producer in Orava) typically contained the highest amount of individual elements, including rare earth elements, Th, U, Ag, Pd, Bi and Be, and their separation from other sites was confirmed by PCA and HCA analyses. In addition, the amounts of Cd, Ba and Re were highest at sites without a clear source of pollution and further monitoring is needed. It was also an unexpected finding that the enrichment factor calculated using UCC values was increased (often considerably >10) for 12 elements at all 15 sites, indicating eventual anthropogenic contamination with P, Zn, B, As, Sb, Cd, Ag, Bi, Pd, Pt, Te and Re (and other EF values were locally increased). Metabolic analyses showed a negative correlation between some metals and metabolites (ascorbic acid, thiols, phenols and allantoin), but slightly positive (amino acids) or highly positive correlation with purine derivatives hypoxanthine and xanthine. The data suggest that lichens adapt their metabolism to excessive metal loading and that epiphytic lichens are suitable for identifying metal contamination even at apparently clean sites.
- Klíčová slova
- Air pollution, Antioxidants, Lichens, PM10 particles, Purine, Toxic metals,
- MeSH
- Ascomycota MeSH
- kadmium metabolismus MeSH
- kovy analýza MeSH
- látky znečišťující vzduch * analýza MeSH
- lišejníky * chemie MeSH
- monitorování životního prostředí MeSH
- těžké kovy * analýza MeSH
- xanthin * metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- kadmium MeSH
- kovy MeSH
- látky znečišťující vzduch * MeSH
- těžké kovy * MeSH
- xanthin * MeSH
Marine organisms have gained considerable biotechnological interest in recent years due to their wide variety of bioactive compounds with potential applications. Mycosporine-like amino acids (MAAs) are UV-absorbing secondary metabolites with antioxidant and photoprotective capacity, mainly found in organisms living under stress conditions (e.g., cyanobacteria, red algae, or lichens). In this work, five MAAs were isolated from two red macroalgae (Pyropia columbina and Gelidium corneum) and one marine lichen (Lichina pygmaea) by high-performance countercurrent chromatography (HPCCC). The selected biphasic solvent system consisted of ethanol, acetonitrile, saturated ammonium sulphate solution, and water (1:1:0.5:1; v:v:v:v). The HPCCC process for P. columbina and G. corneum consisted of eight separation cycles (1 g and 200 mg of extract per cycle, respectively), whereas three cycles were performed for of L. pygmaea (1.2 g extract per cycle). The separation process resulted in fractions enriched with palythine (2.3 mg), asterina-330 (3.3 mg), shinorine (14.8 mg), porphyra-334 (203.5 mg) and mycosporine-serinol (46.6 mg), which were subsequently desalted by using precipitation with methanol and permeation on a Sephadex G-10 column. Target molecules were identified by HPLC, MS, and NMR.
- Klíčová slova
- countercurrent chromatography, isolation, marine lichen, mycosporine-like amino acids, photoprotection, red macroalgae,
- MeSH
- aminokyseliny chemie MeSH
- lišejníky * chemie MeSH
- mořské řasy * chemie MeSH
- protiproudá chromatografie MeSH
- Rhodophyta * chemie MeSH
- rostlinné extrakty metabolismus MeSH
- ultrafialové záření MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- aminokyseliny MeSH
- rostlinné extrakty MeSH
Alcobiosis, the symbiosis of algae and corticioid fungi, frequently occurs on bark and wood. Algae form a layer in or below fungal basidiomata reminiscent of the photobiont layer in lichens. Identities of algal and fungal partners were confirmed by DNA barcoding. Algal activity was examined using gas exchange and chlorophyll fluorescence techniques. Carbon transfer from algae to fungi was detected as 13C, assimilated by algae, transferred to the fungal polyol. Nine fungal partners scattered across Agaricomycetes are associated with three algae from Trebouxiophycae: Coccomyxa sp. with seven fungal species on damp wood, Desmococcus olivaceus and Tritostichococcus coniocybes, both with a single species on bark and rain-sheltered wood, respectively. The fungal partner does not cause any obvious harm to the algae. Algae enclosed in fungal tissue exhibited a substantial CO2 uptake, but carbon transfer to fungal tissues was only detected in the Lyomyces-Desmococcus alcobiosis where some algal cells are tightly enclosed by hyphae in goniocyst-like structures. Unlike lichen mycobionts, fungi in alcobioses are not nutritionally dependent on the algal partner as all of them can live without algae. We consider alcobioses to be symbioses in various stages of co-evolution, but still quite different from true lichens.
- MeSH
- alarminy MeSH
- biologický transport MeSH
- ekzém * MeSH
- hyfy MeSH
- keratóza * MeSH
- lišejníky * MeSH
- uhlík MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- alarminy MeSH
- uhlík MeSH
Since the floristic study of lichens at the Barton and Weaver Peninsulas of King George Island in 2006, there have been intense investigations of the lichen flora of the two peninsulas as well as that of Fildes Peninsula and Ardley Island in Maxwell Bay, King George Island, South Shetland Islands, maritime Antarctic. In this study, a total of 104 species belonging to 53 genera, are identified from investigations of lichens that were collected in austral summer seasons from 2008 to 2016. Phenotypic and molecular analyses were incorporated for taxonomic identification. In particular, 31 species are found to be endemic to the Antarctic and 22 species are newly recorded to the Maxwell Bay region. Lepra dactylina, Stereocaulon caespitosum, and Wahlenbergiella striatula are newly recorded in the Antarctic, and the previously reported taxon Cladonia furcata is excluded from the formerly recorded list due to misidentification. We also provide ecological and geographical information about lichen associations and habitat preferences.
- Klíčová slova
- Antarctic lichen diversity, Ecological traits, Lichen, Lichen taxonomy,
- MeSH
- ekosystém MeSH
- lišejníky * MeSH
- monitorování životního prostředí MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Antarktida MeSH
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.
- Klíčová slova
- Hydropunctaria, Pseudendoclonium, Urospora, Verrucaria, Chile, Undulifilum symbioticum gen. et sp. nov., intertidal rocks, symbiosis,
- MeSH
- Ascomycota * MeSH
- Chlorophyta * genetika MeSH
- fylogeneze MeSH
- lišejníky * genetika MeSH
- symbióza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Lichenized algae and cyanobacteria are known to be shared and selected by unrelated lichen-forming fungi coexisting in so-called photobiont-mediated guilds. Life in such a guild could be crucial for the survival of a large group of lichen fungi dependent on horizontal transmission of photobionts. Here, we investigate frequent lichen phycobionts of the genus Trebouxia in rock-dwelling lichen communities. We found intensive and repeated sharing of specific Trebouxia assemblages by co-occurring lichens across distant localities. Rock chemistry, expressed as pH, determined the composition of photobiont pools and separated three saxicolous lichen guilds, sharing environmentally specific photobiont groups. Moreover, unlike the majority of lichen fungi, many Trebouxia photobionts represented opportunists in the choice of general substrate form (soil-rock-tree bark/wood), maintaining their pH preferences. Thus, saxicolous communities form just a part of a complex guild system that is in principle mediated by environmentally conditioned groups of naturally co-occurring photobionts. The complexity of the system is influenced by diverse photobiont life strategies, including also dispersal style. The findings of photobionts strictly or predominantly associated with sexually reproducing fungi stimulated us to emphasize the role of free-dispersing photobionts in the establishment and maintenance of lichen guilds.
- Klíčová slova
- communities, dispersal, lichen guilds, pH, photobiont, rock chemistry,
- MeSH
- Chlorophyta * MeSH
- fylogeneze MeSH
- houby genetika MeSH
- lišejníky * mikrobiologie MeSH
- symbióza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
