Lichen Species Research Articles

Freeze Substitution Accelerated via Agitation: New Prospects for Ultrastructural Studies of Lichen Symbionts and Their Extracellular Matrix

(1) Background: Lichens, as an important part of the terrestrial ecosystem, attract the attention of various research disciplines. To elucidate their ultrastructure, transmission electron microscopy of resin-embedded samples is indispensable. Since most observations of lichen samples are generated via chemical fixation and processing at room temperature, they lack the rapid immobilization of live processes and are prone to preparation artefacts. To improve their preservation, cryoprocessing was tested in the past, but never widely implemented, not least because of an extremely lengthy protocol. (2) Methods: Here, we introduce an accelerated automated freeze substitution protocol with continuous agitation. Using the example of three lichen species, we demonstrate the preservation of the native state of algal photobionts and mycobionts in association with their extracellular matrix. (3) Results: We bring to attention the extent and the structural variability of the hyphae, the extracellular matrix and numerous crystallized metabolites. Our findings will encourage studies on transformation processes related to the compartmentation of lichen thalli. They include cryopreserved aspects of algal photobionts and observations of putative physiological relevance, such as the arrangement of numerous mitochondria within chloroplast pockets. (4) Conclusions: In summary, we present accelerated freeze substitution as a very useful tool for systematic studies of lichen ultrastructures.

Global trends in biodiversity with tree plantation age

Tree plantations are expanding globally to satisfy demands for wood, food, energy, oil and other ecosystem services, often replacing primary vegetation. Plantations are generally less biodiverse than primary vegetation, yet the effects of plantation age on biodiversity are not well understood. More accurate estimations of biodiversity within plantations over time could improve predictions of the ecological effects of tree planting, guiding more sustainable land use and management decisions. Here, we assess the effects of plantation age on the abundance and number of species of invertebrates, birds, plants, mammals, amphibians, reptiles and lichens, and on compositional similarity to minimally-used primary vegetation. We find that plantations usually support fewer species than both minimally-used primary vegetation and mature secondary vegetation, fewer individuals, and some novel species (i.e. species not also found in primary vegetation). We also find that, on a global scale, plantation age has positive effects on species richness, the abundance of individuals, and compositional similarity to primary vegetation. However, geographic realm, biome, management intensity and plantation type influence the biodiversity trends. We also include a case study for oil palm, showing that species richness increases with oil palm plantation age. Nevertheless, plantations typically remain less biodiverse than natural vegetation even thirty years after planting, especially in the tropics, where compositional similarity between plantations and minimally-used primary vegetation remains approximately 20% lower than the non-tropics. Our results highlight the negative ecological consequences of establishing new plantations in place of primary vegetation or restoration, yet we also reveal spatio-temporal differences in plantation biodiversity.

Mercury content and elemental composition of fruticose lichens from Nahuel Huapi National park (Patagonia, Argentina): Time trends in transplanted and in situ grown thalli

Lichens have a unique structure involving the symbiosis of fungus and algae and can grow on almost any type of substrate. They absorb gases, water, nutrients and pollutants through their cortex, and thus are good indicators of environmental processes, enabling the biomonitoring of environmental pollutants. These organisms are widely distributed; however, as certain species do not occur in some areas, transplants are commonly used to monitor air pollution. In this study, transplants of the fruticose species Protousnea magellanica were set up at the EMMA Station (Global Mercury Observation System, GMOS) located at a suburban site of San Carlos de Bariloche city within Nahuel Huapi National Park (North Patagonia, Argentina). The transplants were used to assess the uptake of certain elements, particularly the accumulation of mercury. Periodic samplings of the transplanted species P. magellanica and the naturally occurring Usnea pusilla were performed concurrently at the experimental site over 483 days of experimental exposure. The elemental composition and concentration of the thalli of these species were determined by Neutron Activation Analysis in a nuclear reactor. Atmospheric mercury concentration (Gaseous Elemental Mercury, GEM) was monitored at the EMMA Station by an automated cold vapor atomic fluorescence system (Tekran 2537B). Mercury concentrations in the lichens were at least three orders of magnitude higher than atmospheric mercury levels (0.80–0.94 ng/m3, ppt), highlighting the accumulation capacity of these organisms. Concentrations found in P. magellanica thalli (0.080–0.327 μg/g dry weight, ppm) lay within the range of values reported previously in lichens from the Nahuel Huapi National Park with low anthropogenic impact. During experimental exposure both lichen species displayed the same trend in Hg content. Total Hg increased from T0 to T1 (day 25) and then decreased up to approximately T4 (day 385). In U. pusilla, the positive relationship between Hg content and lithophilic elements such as La, suggested preferential Hg uptake from airborne particles (deposited dust).

In Vitro and in Silico Studies of Lichen Compounds Atranorin and Salazinic Acid as Potential Antioxidant, Antibacterial and Anticancer Agents.

Lichens are symbiotic organisms made up of alga/cyanobacterium and fungus. We investigated antioxidant, antibacterial and anticancer properties of two lichen compounds, atranorin and salazinic acid, and five lichen species: Heterodermia boryi, Heterodermia diademata, Heterodermia hypocaesia, Parmotrema reticulatum, and Stereocaulon foliolosum. Free radical scavenging, Ferric reducing potential, Nitric oxide scavenging, and Trolox equivalent capacity were used to measure antioxidant activity. Strong radical scavenging action was demonstrated by atranorin and salazinic acid, with IC50 values of 39.31 μM and 12.14 μM, respectively. The Minimum Inhibitory Concentration (MIC) assay based on resazurin, was used to measure antibacterial activity. Parmotrema reticulatum demonstrated significant antibacterial activity against Raoultella planticola with MIC of 7.8 μg/mL. Cytotoxicity assay on breast cancer cell line was used to assess anticancer activity. To further understand the binding locations on the target proteins Er (Estrogen Receptor alpha), EGFR (Epidermal Growth Factor Receptor), mTOR (Mammalian Target of Rapamycin), and PgR (Progesterone Receptor), molecular docking experiments were conducted. Docking study showed that the binding energies of atranorin and salazinic acid with mTOR were -5.31 kcal/mol and -3.43 kcal/mol, respectively. The results suggest that atranorin has the potential to be a multitargeted molecule with natural antioxidant, antibacterial, and anticancer properties.

Reinventory of permanent plots show that kelo lichens face an extinction debt

Intensive forestry has led to landscape level deficits of important substrates such as deadwood and its associated biodiversity. Several taxa face extinction debts due to continuous declines and lack of regeneration of important habitats. Deadwood-dependent lichens are of great conservation concern due to a general lack of deadwood and due to their slow establishment, especially of rare species. In a field restoration experiment in central Sweden, we studied deadwood-dependent lichens for eight years, their association to different types of deadwood and their response to environmental change caused by variable retention forestry, deadwood enrichment and prescribed burning. Prescribed burning and site preparation caused depauperate lichen species assemblages throughout the study period but retention felling did not majorly affect lichen species assemblages. We found that lichen species were nested along deadwood qualities and deadwood created in the experiment only hosted a subset of lichen species found on kelo wood. Despite large reductions of kelo wood with lichen occurrences over the study period, overall species richness did not decrease. The fact that a large part of the lichen community occur only on kelo wood and that kelo wood is not regenerated implies that lichens associated with kelo wood face an extinction debt. In order to avoid local extinctions of deadwood-dependent lichens, site preparation and prescribed burning should be avoided in areas rich in high quality deadwood. There is urgent need to start creating new kelo wood through reoccurring fires in order to halt the impending extinction debt.

Four Species of Rhizocarpon Subg. Phaeothallus in China

Three lichen species are reported from China for the first time: Rhizocarpon cinereovirens, R. rittokense, and R. roridulum. A revision of the Chinese material determined as R. infernulum f. infernulum shows that it belongs to R. infernulum f. sylvaticum. The morphology, secondary chemistry, ecology, and distribution ranges of the species are investigated and discussed. An identification key is given to the species of Rhizocarpon subg. Phaeothallus in China.

Warming decreases desert ecosystem functioning by altering biocrusts in drylands

Abstract Warming and precipitation fluctuations are changing desert ecosystems in global drylands. However, the effects of climate change on keystone species such as cryptogamic biocrust in drylands remain relatively under‐investigated, even though biocrusts play a vital role in desert ecosystems. We conducted a long‐term experiment (14 years) to simulate the responses of two main types of biocrusts to warming coupled with reduction in precipitation that was achieved by open‐top chambers (OTCs) to simulate the predicted warming and precipitation decreasing under climate change scenario. We also conduct a structural analysis to evaluate the resulting changes in desert ecosystem functioning (carbon and nitrogen cycling). Neither warming and corresponding rainfall reduction treatments had a negative effect on lichen species richness, but both treatments reduced lichen cover and biomass. The negative effects of warming on moss‐dominated crusts were much greater than those on lichen‐dominated crusts. Although mosses and lichens had varying degree responses to warming, the loss of mosses and decreased lichen cover and biomass, as well as the shortening of the wet time, resulted in a reduction in carbon and nitrogen fixation, soil enzyme activity and water‐holding capacity of biocrusts and topsoil. These impacts collectively change the water balance of drylands and weaken the hydrological and biogeochemical function of biocrusts. Synthesis and applications: Results from this long‐term experiment suggest that the ecosystem C and N cycling and water balance of global drylands may be highly impacted by climate change, in part because of the response of biocrusts, which contribute an important implication for both dryland restoration and earth system dynamics.

Http://jeb.co.in./journal_issues/202311_nov23/paper_12.pdf

Aim: The aim of this research was to identify a suitable lichen species as a bio-indicator for heavy metals in the Himalayan habitats. Methodology: The study was conducted in a sacred grove located in Western Nepal. The grove was situated alongside the busy Mahakali National highway. Lichen samples were collected from different areas of the grove, ranging from the edge adjacent to the highway to the center. Standard protocols were employed to identify the collected lichen species. The heavy metal content in the samples were analyzed by subjecting them to acid digestion followed by AAS estimation. Results: Three lichen species were discovered: Bulbothrix meizospora, Parmotrema tinctorum, and Pyxine berteriana. Pyxine berteriana was collected near the highway, while Bulbothrix meizospora and Parmotrema tinctorum were collected away from it. The heavy metal bioaccumulation pattern observed was as follows: Fe>Al>Mg>Zn>Cu>Pb>Mn>Ni>Cd>Cr. Notably, Pyxine berteriana exhibited the highest metal concentrations among the three species. Interpretation: Based on the findings, it can be concluded that the Physcioid lichen Pyxine berteriana is the most resilient species in the region and can serve as an appropriate bio-indicator for studying the deposition of heavy metals in the ambient air. Key words: Physcioid lichens, Pyxine berteriana, Parmotrema tinctorum, Lichens, Sacred Grove

New species and new records of genus Buellia (lichenized Ascomycota, Caliciaceae) from Pakistan using electron microscopy and DNA barcoding techniques.

Three new species Buellia darelensis, B. densitheca, B. kashmirensis and two new records B. elegans and B. taishanensis are added to the lichen biota of Pakistan. Buellia darelensis and B. kashmirensis share the same habitats found on the rock while B. densitheca colonized on bark of Pinus hardwoods in the Himalayan forest, Pakistan. Morphological, chemical, and phylogenetic analyses were carried out to elucidate the placement of these species and to support the delimitation of the new taxa. Detailed descriptions and figures for the species are given, and a key to all known buellioid species from Pakistan is provided. RESEARCH HIGHLIGHTS: During recent explorations of lichens from different regions of Pakistan, we observed specimens that could not be readily assigned to any known species. A phylogenetic analysis of the internal transcribed spacer nrDNA region confirms their position within the genus Buellia, and morphological data showed distinctiveness of three species from other known species of the genus. We therefore describe these specimens as new species to science, and two species are as new records for the country. Pakistan exhibits a large altitudinal variation, with climatic conditions and a diverse vegetation that supports a diverse and conspicuous lichen biota. The nature reserves have abundant biological resources, and it is expected that more new species of lichen may be discovered in the future.

Effect of the Extracts from Lichens and Lichenophilic Fungi on <i>in vitro</i> Growth of Clinically Significant Microorganisms

Abstract—Activity of the ethanol extracts from lichens (LE), of the cultures of lichenophilic (endobiotic) fungi (LFE), and of ethanol extracts from these cultures was tested using the following test organisms: Escherichia coli, Salmonella typhimurium, Pseudomonas fluorescens, Staphylococcus aureus, Micrococcus luteus, Enterococcus faecium, Paenibacillus sp., and Candida parapsilosis. Selective activity of LE and LFE against yeasts and gram-positive and gram-negative bacteria was revealed. The extracts from Cladonia rangiferina exhibited no activity against any of the tested cultures. The previously reported locus effect on activity of metabolites of one lichen species was confirmed. Agar block technique was used to detect selective activity of 23 out of 61 analyzed fungal strains against gram-positive and gram-negative bacteria, and of 8 strains, against yeasts. Ethanol extracts of six cultures were shown to suppress growth of St. aureus, M. luteus, Paenibacillus sp., and E. coli. Strain NM10F28209 from the lichen Stereocaulon paschale, which exhibited inhibitory activity against Ca. parapsilosis was selected for priority development of an antifungal preparation.

Photosynthesis of widespread lichen species in pine forests of Central Siberia

Lichens and other terrestrial photosynthetic unicellular organisms of the planet consume nearly 14.3 billion tons of atmospheric CO2. Due to climate change, such important components of the forest ground cover as lichens are very vulnerable. This study evaluates the photosynthetic activity in widespread lichens by measuring the indices of net photosynthesis, dark respiration, and prompt fluorescence. Hence, cryptogams of pine forests in Central Siberia near the Zotino tall tower observatory (ZOTTO) are characterized as highly active. Cladonia stellaris (Opiz.) Brodo and Cladonia rangiferina (L.) are the main representatives of ground cover species. The purpose of this study was to determine the photosynthetic activity in dominant species of ground cover lichens during a growing season. We found the seasonal dynamics of photosynthesis with the lowest values being observed in June, and the highest ones in August. Dark respiration peaks in June and is the lowest in September. Fluorescence values are within the range of 6.7 ± 0.3. The species under study that grow on podzol soils in pine forests show fast kinetic activation.

Pyxine tiinae (Caliciaceae, Ascomycota), a new lichen species from high elevation in Peru


 
 
 Pyxine tiinae, a new foliose lichen species, is described from an alpine locality in Peru. The new species is character- ized by convex and radiating, grey lobes, a K– cortex and K– epihymenium, the presence of terpenes, and by comparatively long pycnoconidia. A phylogenetic analysis places P. tiinae as sibling to the genus Culbersonia, although the morphological characters do not fit with either this genus or with Pyxine as currently circumscribed.
 
 

Antioxidant and antidiabetic activity and phytoconstituents of lichen extracts with temperate and polar distribution.

The objective of this research was to characterize the chemical composition of ethanolic extracts of the lichen species Placopsis contortuplicata, Ochrolechia frigida, and Umbilicaria antarctica, their antioxidant activity, and enzymatic inhibition through in vitro and molecular docking analysis. In total phenol content, FRAP, ORAC, and DPPH assays, the extracts showed significant antioxidant activity, and in in vitro assays for the inhibition of pancreatic lipase, α-glucosidase, and α-amylase enzymes, together with in silico studies for the prediction of pharmacokinetic properties, toxicity risks, and intermolecular interactions of compounds, the extracts evidenced inhibitory potential. A total of 13 compounds were identified by UHPLC-ESI-QTOF-MS in P. contortuplicata, 18 compounds in O. frigida, and 12 compounds in U. antarctica. This study contributes to the knowledge of the pool of bioactive compounds present in lichens of temperate and polar distribution and biological characteristics that increase interest in the discovery of natural products that offer alternatives for treatment studies of diseases related to oxidative stress and metabolic syndrome.

Acarospora americana (Acarosporaceae), a new species for Eurasia from the European part of Russia

A lichen species Acarospora americana H. Magn., new to Russia and Eurasia, was discovered on the territory of the Pavlovsk granite quarry in the Voronezh Region. A detailed description of morphological and anatomical features is given, chemotaxonomic analysis is carried out. A comparison is made with closely related species: A. fuscata (Ach.) Arnold and A. veronensis A. Massal. ITS nrDNA sequence is obtained.

Новые находки лишайников и лихенофильных грибов с архипелага Земля Франца-Иосифа (Российская Арктика)

The study presents data on 24 species of lichens and seven species of lichenicolous fungi that are newly recorded in the Franz Josef Land Archipelago. Among these, Amandinea pelidna, Didymocyrtis bryonthae, and Sclerococcum parasiticum are new discoveries for European Russia, and another 12 species are newly documented for the Arkhangelsk Region. Thus, 301 species of lichens and 50 species of lichenicolous fungi are currently known for the Franz Josef Land Archipelago.

Lichen Biodiversity and Near-Infrared Metabolomic Fingerprint as Diagnostic and Prognostic Complementary Tools for Biomonitoring: A Case Study in the Eastern Iberian Peninsula.

In the 1990s, a sampling network for the biomonitoring of forests using epiphytic lichen diversity was established in the eastern Iberian Peninsula. This area registered air pollution impacts by winds from the Andorra thermal power plant, as well as from photo-oxidants and nitrogen depositions from local and long-distance transport. In 1997, an assessment of the state of lichen communities was carried out by calculating the Index of Atmospheric Purity. In addition, visible symptoms of morphological injury were recorded in nine macrolichens pre-selected by the speed of symptom evolution and their wide distribution in the territory. The thermal power plant has been closed and inactive since 2020. During 2022, almost 25 years later, seven stations of this previously established biomonitoring were revaluated. To compare the results obtained in 1997 and 2022, the same methodology was used, and data from air quality stations were included. We tested if, by integrating innovative methodologies (NIRS) into biomonitoring tools, it is possible to render an integrated response. The results displayed a general decrease in biodiversity in several of the sampling plots and a generalised increase in damage symptoms in the target lichen species studied in 1997, which seem to be the consequence of a multifactorial response.

Anti-obesity effects of olivetol in adult zebrafish model induced by short-term high-fat diet

Obesity is a complex disease caused by various factors, and synthetic drugs used to treat it can have side effects. Natural compounds, such as olivetol, could be a promising alternative. Olivetol is a substance found in certain lichen species and has anti-inflammatory and anti-cancer properties. In this study, researchers conducted in-silico molecular docking studies and found that olivetol had significant binding affinity with receptors involved in obesity. They also investigated the effects of olivetol on a diet-induced obese zebrafish model and found that high doses of olivetol reduced excessive fat accumulation and triglyceride and lipid accumulation. The low dose of olivetol showed a significant reduction in liver enzymes' levels. However, the high dose of olivetol resulted in a significant increase in HMG-CoA levels. These results suggest that olivetol may be a promising anti-obesity agent for the treatment of hyperlipidemia-related disorders, but further research is necessary to understand its full effects on the body.

Новые сведения о лихенобиоте Корякии (Северная Камчатка, Россия)

Based on collections of Koryak geobotanical expeditions of the Komarov Botanical Institute, 23 species of lichens and four lichenicolous fungi are reported as new to Koryakia, nine of them are also new to Kamchatka. Ephebe hispidula, Lambiella impavida, Rhizocarpon simillimum, Rhizoplaca opiniconensis, and Vestergrenopsis isidiata are new to the Russian Far East. Altogether 529 species of lichens and allied fungi are currently known for Koryakia.

Lichens of Larsemann Hills and adjacent oases in the area of Prydz Bay (Princess Elizabeth Land and MacRobertson Land, Antarctica)

The lichen flora of coastal (Larsemann Hills, Landing Bluff, Rouer Islands) and internal (Clemence Massif, Radok Lake, Luff Nunatak, Stinear, Rymill and Bloomfield Mountains and others) oases (Princess Elizabeth Land and Mac Robertson Land, Antarctica) was investigated. 72 lichen species (incl. 48 species known for the Larsemann Hills) belonging to 34 genera and 14 families were recorded. Investigated species are listed and data on localities, habitats and frequency of occurrence are provided. The most common lichens in the area are Candelariella flava, Lecidea cancriformis, Lecanora fuscobrunnea, Buellia frigida, Rinodina olivaceobrunnea and Acarospora gwynnii.

The non-native Quercus rubra does not substitute the native Quercus robur and Q. petraea as substrate for epiphytic lichens and bryophytes

Climate change will cause alterations in tree species ranges. Non-native tree species are likely to be increasingly used in production forests, due to their often better adaptation to a warmer climate and their lower susceptibility to pests and pathogens. Trees form an important habitat for numerous species, many of which are more or less specialised regarding tree species. Thus, the tree-associated flora and fauna may be heavily impacted if non-native trees replace native ones. Risk assessments from the introduction of non-native trees must rest on a solid knowledge base, including insights into the potential of such trees to function as biodiversity substitutes, i.e. to host similar biodiversity as closely related native tree species. In a study in temperate Sweden, we inventoried epiphytic lichens and bryophytes on ten random trees in each of 28 stands (14 stands of North American red oak Quercus rubra and 14 stands of native oak Q. robur/petraea), to compare species richness and composition. Overall, 101 lichen taxa and 35 bryophyte taxa were identified, and we found a generally higher diversity for native oak. The regional species richness (gamma diversity) for both lichens and bryophytes was higher in native oak than in red oak, and the lichen species richness at stand level (alpha diversity) was nearly significantly higher. Lichen composition differed between the two oak species, while there was no difference for bryophytes. More lichens were strongly associated with native oak than red oak, while most bryophyte species were generalists with no specific preference for either oak taxa. Bark structure was an important explanatory variable separating the lichen epiphytes, with species preferring smooth bark largely confined to red oak. In conclusion, our study suggests that substituting native oak with red oak could have adverse consequences for epiphytic lichen populations associated with native oak, resulting in a decline of several species. However, certain lichen and bryophyte species were exclusively found on Q. rubra, implying that incorporating a proportion of red oak stands in southern Swedish landscapes may enhance diversity. Further research is needed to explore the overlap between species associated with Q. rubra and other deciduous tree species that possess similar smooth bark. Our findings indicate that red oak may not be an appropriate alternative host tree for epiphytic lichens typically found on native oak, while the implications for bryophytes remain less clear.