Search Results (159)

Lichens, complex symbiotic associations between fungi and photosynthetic partners, are widespread in terrestrial ecosystems but remain poorly studied in tropical dry forests (TDFs). This review synthesizes current knowledge on the diversity, ecological roles, adaptive traits, and ethnobotanical uses of lichens in TDFs, with a focus on the Neotropics. As most lichens discussed here are crustose species that inhabit tree bark, this paper also provides a thoughtful review of the origin, distribution, and highly heterogeneous floristic composition of TDFs, which directly shape lichen habitats. It discusses how lichens have evolved to cope with seasonal water stress, emphasizing desiccation tolerance as a key feature of the symbiosis. This review also explores lichen community composition, interactions with host trees, microclimatic conditions, herbivory, and soil crust formation. Despite evidence of high species richness, functional diversity, and ecological importance, lichens in TDFs are largely overlooked in conservation strategies. Moreover, several regions remain vastly understudied, and many species likely remain undescribed. Ethnolichenological practices, though scarce, underscore the cultural and medicinal value of these organisms. Given the high rates of habitat loss and endemism in TDFs, there is a pressing need to expand research on lichen diversity and to investigate the evolutionary origins of their survival strategies. The conservation of these lichens is inseparable from the conservation of TDFs themselves. Understanding how lichens adapt to the harsh and variable conditions of TDFs is essential for integrating them into biodiversity conservation and ecosystem restoration frameworks. Full article

The advent of next-generation sequencing technologies has given rise to considerably diverse techniques. However, integrating data from these technologies to generate high-quality genomes remains challenging, particularly when starting from metagenomic data. To provide further insight into this process, the genome of the lichenized fungus Solorina crocea was sequenced using DNA extracted from the thallus, which contains the genome of the mycobiont, along with those of the photobionts (a green alga and a cyanobacterium), and other associated microorganisms. Three different strategies were assessed for the assembly of a de novo genome, employing data obtained from Illumina and PacBio HiFi technologies: (1) hybrid assembly based on metagenomic data; (2) assembly based on metagenomic long reads and scaffolded with filtered mycobiont long and short reads; (3) hybrid assembly based on filtered mycobiont short and long reads. Assemblies were compared according to contiguity and completeness criteria. Strategy 2 achieved the most continuous and complete genome, with a size of 55.5 Mb, an N50 of 148.5 kb, and 519 scaffolds. Genome annotation and functional prediction were performed, including identification of secondary metabolite biosynthetic gene clusters. Genome annotation predicted 6151 genes, revealing a high number of genes associated with transport, carbohydrate metabolism, and stress response. Full article

Ochrolechia is a diverse and charismatic lineage of both sexually and asexually reproducing lichens, with centers of species richness in northern temperate areas of the world, including North America. As part of recent work to comprehensively inventory the lichens of the Indian Peaks Wilderness (Arapaho–Roosevelt National Forest, Front Range Mountains, Colorado), we discovered material of a sorediate member of the genus to which no existing names could be applied. This material was collected in very remote, extremely difficult-to-access mid-montane forests of the west slope of the Indian Peaks Wilderness, in a steep and jagged off-trail drainage (Hell Canyon). Subsequent study of this material along with review of pre-existing collections at the COLO Herbarium revealed it to represent a new scientific species. We here formally describe Ochrolechia raynori, in honor of Seth Raynor who led the Indian Peaks Wilderness lichen inventory. We additionally document the occurrence of Dactylospora parasitica on this new lichen species. Ochrolechia raynori is distinctive for its continuous, smooth, shiny thallus that bears discrete soralia and coarse soredia, its occurrence on mosses and other lichens that overgrow rocks, and its chemistry. We generated a molecular phylogeny of this and other members of Ochrolechia using the nrITS locus and show O. raynori to be sister to the widespread, sexually reproducing species O. upsaliensis. This occurrence of an asexual species that is sister to a sexual species is consistent with the “species pair” hypothesis in lichenology, which suggests an intimate role of reproductive mode divergence in the process of speciation. Examination of the phylogeny yielded evidence of four additional pairs in Ochrolechia, for a total of five species pairs, which indicates that this phenomenon may be a common occurrence in this lineage. IUCN Conservation Assessment of Ochrolechia raynori revealed the species to be best considered as Critically Endangered. However, we expect that continued efforts to inventory the lichens of the southern Rocky Mountains, especially in some of its wildest, most remote regions in similar habitats, will likely result in the discovery of additional populations of this remarkable new species. Full article

Lichens, symbiotic organisms with a high tolerance to harsh environments, possess a greater diversity of sterols than other organisms. Sterols are involved in maintaining membrane integrity, hormone biosynthesis, and signal transduction. (1) Background: A characteristic feature of lichen sterols is a high degree of unsaturation, which influences membrane properties. Desaturases play an important role in the synthesis of unsaturated sterols, in particular, sterol C-5 desaturase (ERG3), which controls the conversion of episterol to ergosterol. Earlier, we demonstrated that the treatment of the lichen Peltigera canina with low and elevated temperatures results in changes in the levels of episterol and ergosterol. (2) Methods: Here, for the first time, we identified ERG3 in P. canina and, using an in silico analysis, we showed that PcERG3 belongs to the superfamily of fatty acid hydrolyases. A phylogenetic analysis was conducted to determine the evolutionary relationships of PcERG3. (3) Results: A phylogenetic analysis showed that PcERG3 clusters with ERG3 from other Peltigeralian and non-Peltigeralian lichens and also with ERG3 from free-living fungi. This suggests that PcERG3 has an ancient evolutionary origin and is related to fungi with lichenized ancestors, e.g., Penicillium. The differential expression of PcERG3 in response to temperature stress, a dehydration/rehydration cycle, and heavy metal exposure suggests that it plays a crucial role in maintaining the balance between more and less saturated sterols and, more generally, in membrane functioning. The multifaceted response of P. canina to abiotic stresses was documented by simultaneously measuring changes in the expression of PcERG3, as well as the genes encoding the heat shock proteins, PcHSP20 and PcHSP98, and PcSOD1, which encodes the antioxidant enzyme superoxide dismutase. (4) Conclusions: These findings suggest that PcERG3 is similar to the sterol C-5 desaturases from related and free-living fungi and plays important roles in the molecular mechanisms underlying the tolerance of lichens to environmental stress. Full article

The Antarctic continent hosts highly specialized microbial ecosystems, particularly within endolithic habitats, where microorganisms colonize the interior of rocks in order to withstand conditions that otherwise cannot support life. Previous studies have characterized the composition and abundance of these communities, as well as their different degrees of stress power; furthermore, the effect of different lithic substrates in shaping their associated bacterial assemblages has been extensively investigated. By contrast, how rock typology exerts fungal endolithic colonization still remains unexplored. In this study, we have considered and compared fungal communities inhabiting granite and sandstone rocks collected across Victoria Land, Antarctica, using high-throughput sequencing of the Internal Transcribed Spacer (ITS) region. Our analyses revealed that both rock types were dominated by Ascomycota, with a marked prevalence of lichen-forming fungi, particularly within the class Lecanoromycetes. However, granite-supported communities exhibited significantly higher species richness, likely driven by the structural heterogeneity of the substrate and the presence of fissures enabling chasmoendolithic colonization. In contrast, sandstone communities were more specialized and dominated by strict cryptoendolithic taxa capable of surviving within the rock’s pore spaces. Differential abundance analysis identified key species associated with each substrate, including the lichen Buellia frigida in granite and the black fungus Friedmanniomyces endolithicus in sandstone, two endemic species in Antarctica. Moreover, the use of presence/absence- versus abundance-based diversity metrics revealed contrasting ecological patterns; substrate type had a stronger influence on species presence, whereas geographic location more significantly shaped abundance profiles, highlighting the complex interplay between both factors in determining fungal community composition. Additionally, alpha diversity analyses showed significantly higher species richness in granite compared to sandstone, suggesting that structural heterogeneity and chasmoendolithism may promote a more diverse fungal assemblage. Full article

Lichenized fungi, recognized as an ecologically vital and pharmaceutically promising resource, hold substantial value in both environmental conservation and medicinal applications. As the second largest subclass within the lichen-forming fungi of Lecanoromycetes, Ostropomycetidae emerged as a critical reservoir of bioactive secondary metabolites. Current research has revealed that these secondary metabolites demonstrate remarkable bioactivities, positioning them as potential sources for novel pharmaceutical compounds. Despite considerable progress in characterizing chemical constituents and evaluating bioactivities within this subclass, a systematic summary of these discoveries remains absent. This review synthesizes the lichenochemical research progress, providing critical evaluations of 202 structurally characterized compounds from Ostropomycetidae lichen species over recent decades. These Ostropomycetidae-derived compounds cover the phenols, polyketides, fatty acids, terpenoids, steroids, and non-ribosomal peptides, and exhibit diverse bioactivities including antitumor, anti-inflammatory, antibacterial, antifungal, antiviral, antioxidant, anti-angiogenic, anti-neurodegenerative diseases, antitubercular, anti-herbivore, and antitrypanosomal, and so on. The aim of this review is to establish a robust chemodiversity framework and to offer strategic guidance for targeted exploration of lichen-derived drug candidates in the biological resources of Ostropomycetidae lichens. Full article

Persistent fungal pathogens remain a threat to global food security as these pathogens continue to infect crops despite different mitigating strategies. Traditionally, synthetic fungicides are used to combat these threats, but their environmental and health impacts have spurred interest in a more sustainable, eco-friendly approach. Endolichenic fungi (ELF) are a relatively underexplored group of microorganisms found thriving inside the lichen thalli. They are seen as promising alternatives for developing sustainable plant disease management strategies. Hence, in this study, a total of forty ELF isolates from two fruticose lichen hosts—Ramalina and Usnea, were tested and compared for their antagonistic activities against three economically important filamentous fungal pathogens—Colletotrichum gloeosporioides, Cladosporium cladosporioides, and Fusarium oxysporum. The results of the dual culture assay showed that all ELF isolates successfully reduced the growth of the three filamentous fungal pathogens with varying degrees, and with direct contact inhibition as the predominant trait among the endolichenic fungi. Comparing the antagonistic activities between the different endolichenic fungi from the two lichen hosts, ELF isolates from Ramalina generally demonstrated a higher percentage inhibition of growth of the test fungi as compared to ELF isolates from Usnea. This study underscores the importance of endolichenic fungi as an efficient biocontrol agent. Full article

In the present work, two species new to science, Bacidia subheterochroa and Bacidina terceirae, are reported among one hundred and five lichens and lichenicolous species reported from the islands Graciosa and Terceira (Azores Archipelago, Portugal). Updated phylogenetic studies of the family Ramalinaceae including these samples show that species of Bacidia are grouped in three different clades: Bacidia s. str. (type species B. rosella), Bacidina (type species Bn. phacodes), and Woessia (type species W. fusarioides). As a result, seven new combinations in the resurrected genus Woessia are here proposed. In addition, a comprehensive checklist of lichens and lichenicolous fungi of two of the islands (including locality and substrate) is provided, with five species being reported from Azores for the first time. Full article

Antioxidants are indispensable in protecting the skin from oxidative stress caused by environmental factors such as ultraviolet (UV) radiation, pollution, and lifestyle-related influences. This review examines the essential role of antioxidants in modern cosmetology, highlighting their dual functionality as protective agents and active components in skincare formulations. Oxidative stress, primarily driven by an imbalance between reactive oxygen species (ROS) production and the skin’s defense mechanisms, accelerates aging processes, damages cellular structures, and compromises skin integrity. Antioxidants, whether natural or synthetic, act by neutralizing ROS, reducing inflammation, and promoting cellular repair, effectively mitigating these harmful effects. This comprehensive analysis synthesizes findings from 280 studies accessed via key databases, including PubMed, Scopus, and ScienceDirect. It investigates the biochemical mechanisms of antioxidant activity, emphasizing compounds such as vitamins (C, E, A), carotenoids, polyphenols, peptides, and minerals, alongside bioactive extracts derived from algae, fungi, lichens, and plants. Carotenoids, including ꞵ-carotene, lutein, lycopene, and astaxanthin, demonstrate potent antioxidant activity, making them crucial for photoprotection and anti-aging. Phenolic compounds, such as ferulic acid, resveratrol, hesperidin, and xanthohumol, play a significant role in neutralizing oxidative stress and improving skin health. This review also highlights bioactives from algae, fungi, and lichens. Algae, particularly microalgae like Haematococcus pluvialis, known for astaxanthin production, are highlighted for their extraordinary photoprotective and anti-aging properties. Brown algae (Fucus vesiculosus) and red algae (Porphyra) provide polysaccharides and bioactive molecules that enhance hydration and barrier function. Fungi contribute a wealth of antioxidant and anti-inflammatory compounds, including polysaccharides, ꞵ-glucans, and enzymes, which support cellular repair and protect against oxidative damage. Lichens, through unique phenolic metabolites, offer potent free-radical-scavenging properties and serve as effective ingredients in formulations targeting environmental stress. Plant-derived antioxidants offer a diverse range of benefits. Plant-derived antioxidants, such as flavonoids, phenolic acids, and carotenoids, further amplify skin resilience, hydration, and repair mechanisms, aligning with the growing demand for nature-inspired solutions in cosmetics. The integration of these diverse natural sources into cosmetic formulations reflects the industry’s commitment to sustainability, innovation, and efficacy. By harnessing the synergistic potential of bioactives from algae, fungi, lichens, and plants, modern cosmetology is advancing toward multifunctional, health-conscious, and eco-friendly products. Future research directions include optimizing delivery systems for these bioactives, enhancing their stability and bioavailability, and expanding their applications to meet evolving dermatological challenges. Full article

Xanthone dimers, a distinctive class of natural metabolites renowned for their unique structures, are abundantly present in a diverse array of angiosperms, fungi, and lichens. These compounds not only exhibit remarkable diversity but also possess a broad spectrum of biological activities. In this comprehensive review spanning from 1966 to 2024, we synthesized the relevant literature to delve into the natural occurrence, biological potency, molecular structure and chemical diversity of xanthone dimers. The aim of this review is to serve as an insightful reference point for future scientific inquiries into xanthone dimers and their potential applications. Full article

In restoration practice, direct methods become necessary when indirect methods fail and when aesthetic, chemical, or physical biodeteriorative effects threaten the integrity and legibility of the artifact. More effective methods that prioritize the health of workers and the environment are essential for the outdoor stone monument’s conservation. Although several low-impact methods have been proposed, more case studies are needed to address different biopatina types, products, and lithic substrates. Within the COLLINE Project we focused on peperino, a dark volcanic stone widely used in central Italy since the 7th century BCE, because it has been poorly investigated in terms of diversity of biodeteriogens and low-impact methods for their removal. Direct observation, culture methods, and molecular identification have been applied for the identification of biodeteriogens with particular attention to black meristematic fungi. Three low-impact products, namely a dimethyl sulfoxide (DMSO)-based gel, BioTersus^® (essential oil-based), and Nasier (enzyme-based) were tested in ex situ (on a colonized slab) and in situ trials (on the pulpit of the S. Francesco alla Rocca Basilica, Viterbo, Italy). Three analytical methods, namely reflectance spectroradiometry, laser-induced fluorescence (LIF), and hypercolorimetric multispectral imaging (HMI) were used to test the cleaning efficacy. Results evidenced the strong influence of direct irradiation and water availability in the balance and distribution of phototrophs, fungi, and lichens. The low-impact cleaning methods, particularly the DMSO-based gel and BioTersus^®, effectively remove biodeteriogens from peperino stone while preserving its integrity, offering sustainable solutions for cultural heritage conservation. The instrumental analyses showed that reflectance spectroradiometry and LIF effectively validated the cleaning efficacy, albeit with different sensibility, while HMI, despite spatial constraints, confirmed the three tested cleaning methods do not interfere with peperino stone. Full article

The biodeterioration process involves the alteration of stone monuments by living organisms, such as bacteria, algae, fungi, lichens, mosses, ferns, and vascular plants, combined with abiotic factors, resulting in physical and chemical damage to historic buildings. This study aims to investigate the role of the vascular plants affecting four archaeological parks in Campania—Pompeii, Herculaneum, Paestum, and Velia—by analyzing correlations with building materials, exposure, and conservation status. To represent species associations and their coverage percentages at each site, transects of one square meter were employed. The hazard index (HI) was applied to evaluate the impact of the identified biodeteriogens. A total of 117 species were detected across 198 samples collected from the four study sites, with 59 taxa recorded in Pompeii, 56 in Paestum, 41 in Velia, and 36 in Herculaneum. Specifically, Pompeii hosts a predominance of cosmopolitan species (35%) and widely distributed taxa (15%) due to elevated anthropogenic disturbance. Conversely, mediterranean species dominate in Paestum (62%) and Herculaneum (52%), reflecting more stable ecological conditions. Substrate type significantly influences the hazard index, whereas exposure was found to have minimal impact on both the average coverage and the measured hazard index. Future work will focus on developing site-specific conservation strategies that consider substrate properties, vegetation impact, and anthropogenic disturbances to effectively mitigate the biodeterioration risks posed by vascular flora in Italian monumental sites. Full article

Phosphorus (P) in soil is important in the process by which soil microbial communities regulate soil enzyme activity. We aim to explore how short-term P fertilization affects the composition and functionality of the soil fungal community, offering insights into the complex responses of soil fungi to fertilization. Soil samples from a long-term experiment with no P fertilization were collected for pot experiments. The pot experiment included four treatments: non-P fertilizer (NK), chemical P fertilizer (NPK), 1/2 organic fertilizer + 1/2 chemical fertilizer (MNP), and organic fertilizer (M). High-throughput sequencing was employed to analyze the composition, diversity, and functionality of soil fungal communities. Results showed that short-term P addition significantly increased the soil fungal Shannon and Pielou e indices, with increases of 34.48%~59.00% and 29.79%~53.19%, respectively. Ascomycota and Basidiomycota were the most abundant fungal phyla, whereas Cladosporium and Emericellopsis were the most abundant genera. The main factors affecting soil fungal community composition were total nitrogen (TN) and organic matter (OM). A linear discriminant analysis effect size (LEfSe) analysis indicated that Mortierellomycota were significantly enriched under the NPK treatment. A FUNGuild analysis revealed that, compared to the NK treatment, the relative abundance of Animal Pathogen–Endophyte–Lichen Parasite–Plant Pathogen–Wood Saprotroph was reduced by 67.54%, 46.93%, and 44.10% under NPK, MNP, and M treatments, respectively. The relative abundance of Plant Pathogen was less than 1% in the NPK and the MNP treatments. These results indicate that short-term P addition increased soil nutrient levels and soil fungal community diversity. Chemical P fertilizer significantly improved the fungal community structure in yellow paddy soils, enhancing beneficial fungi and suppressing pathogens. Full article

Endolichenic fungi represent an important ecological group of microorganisms that form associations with photobionts in the lichen thallus. These endofungi that live in and coevolve with lichens are known for synthesizing secondary metabolites with novel structures and diverse chemical skeletons making them an unexplored microbial community of great interest. As part of our search for new phytoprotectants, in this work, we studied the endolichenic fungus Xylaria sp. isolated from the lichen Hypogymnia tubulosa, which grows as an epiphyte on the bark of the endemic Canarian tree Pinus canariensis. From the extract of the liquid fermentation, we isolated two unreported piliformic derivatives, (+)-9-hydroxypiliformic acid (1) and (+)-8-hydroxypiliformic acid (2), along with four previously reported compounds, (+)-piliformic acid (3), hexylaconitic acid A anhydride (4), 2-hydroxyphenylacetic acid (5), and 4-hydroxyphenylacetic acid (6). Their structures were elucidated based on NMR and HRESIMS data. The extract and the isolated compounds were tested for their insect antifeedant (Myzus persicae, Rhopalosiphum padi, and Spodoptera littoralis), antifungal (Alternaria alternata, Botrytis cinerea, and Fusarium oxysporum), nematicidal (Meloidogyne javanica), and phytotoxic effects on mono- and dicotyledonous plant models (Lolium perenne and Lactuca sativa). Compounds 4, 5, and 6 were effective antifeedants against M. persicae and 4 was also active against R. padi. Moreover, 3 and 4 showed antifungal activity against B. cinerea and 4 was the only nematicidal. The extract had a strong phytotoxic effect on L. sativa and L. perenne growth, with compounds 3, 4, and 5 identified as the phytotoxic agents, while at low concentrations compounds 3 and 4 stimulated L. sativa root growth. Full article

Fungi can be used as bioindicators to assess the biodiversity and conservation status of different habitats because of their high adaptability and sensitivity to changes in water, air, and soil quality. In this study, records of macrofungi and lichenised fungi were extracted from GBIF, surveyed using GIS software, and used to compare the fungal diversity of the Pyrenean oak and chestnut groves of Castilla y León, analysing the possible implications of their presence for the conservation of these forest habitats. In Quercus pyrenaica forests, a greater number of lichen and macrofungi species and records were recorded than in Castanea sativa forests, although the greater area occupied by the former could have influenced this diversity. The higher presence of ectomycorrhizal macrofungal species in chestnut groves, as well as the higher sensitivity to pollution of lichens in Pyrenean oak-dominated environments, showed the relevance of the analysis of these data for a better understanding of the conservation status of forest habitats. However, in order to obtain more accurate results, it would be necessary to carry out specific studies on a smaller scale. Full article