Phylogenetic Assessment of Understudied Families in Hymenochaetales (Basidiomycota, Fungi)-Reporting Uncovered Species and Reflecting the Recent Taxonomic Updates in the Republic of Korea.

Hymenochaetales Oberw. is an order classified in Basidiomycota of Fungi, and species in this order display notable diversity. They exhibit various fruiting body shapes, including clavarioid, effused-reflexed, and resupinate basidiomes. Few mycorrhizal species have been reported in Hymenochaetales, but wood-decaying species dominate the order. Hymenochaetaceae Imazeki & Toki and Schizoporaceae Jülich are the most species-rich families within Hymenochaetales, and most species in the Republic of Korea belong to these two families. As such, current taxonomic classification and nomenclature are not reflected upon species in the remaining Hymenochaetales families. For this study, a multifaceted morphological and multigenetic marker-based phylogenetic investigation was conducted to, firstly, comprehensively identify understudied Hymenochaetales specimens in Korea and, secondly, reflect the updates on the species classification. Five genetic markers were assessed for the phylogenetic analysis: nuclear small subunit ribosomal DNA (nSSU), internal transcribed spacer (ITS), nuclear large subunit ribosomal DNA (nLSU), RNA polymerase II subunit 2 gene (RPB2), and translation elongation factor 1 gene (TEF1). The results from phylogenetic analysis supported 18 species classified under eight families (excluding Hymenochaetaceae and Schizoporaceae) in Korea. Species formerly placed in Rickenellaceae and Trichaptum sensu lato have been systematically revised based on recent taxonomic reconstructions. In addition, our findings revealed one new species, Rickenella umbelliformis, and identified five formerly nationally unreported species classified under five understudied families. Our findings contribute to a better understanding of Hymenochaetales diversity and highlight the need for continued research.

3'-Sialyllactose alleviates bone loss by regulating bone homeostasis.

Osteoporosis is a common skeletal disease that results in an increased risk of fractures. However, there is no definitive cure, warranting the development of potential therapeutic agents. 3'-Sialyllactose (3'-SL) in human milk regulates many biological functions. However, its effect on bone metabolism remains unknown. This study aimed to investigate the molecular mechanisms underlying the effect of 3'-SL on bone homeostasis. Treatment of human bone marrow stromal cells (hBMSCs) with 3'-SL enhanced osteogenic differentiation and inhibited adipogenic differentiation of hBMSCs. RNA sequencing showed that 3'-SL enhanced laminin subunit gamma-2 expression and promoted osteogenic differentiation via the phosphatidylinositol 3­kinase/protein kinase B signaling pathway. Furthermore, 3'-SL inhibited the receptor activator of nuclear factor κB ligand-induced osteoclast differentiation of bone marrow-derived macrophages through the nuclear factor κB and mitogen­activated protein kinase signaling pathway, ameliorated osteoporosis in ovariectomized mice, and positively regulated bone remodeling. Our findings suggest 3'-SL as a potential drug for osteoporosis.

Factors Affecting the Life Satisfaction of School-Aged Children with Vietnamese Immigrant Mothers in Korea.

Low life satisfaction among multicultural children is an important issue related to children's mental health in Korea. The purpose of this study was to identify factors influencing the life satisfaction of children whose Vietnamese mothers migrated to Korea for marriage. Data from the Multicultural Adolescents Panel Study (MAPS) conducted by the National Youth Policy Institute (NYPI) in 2020 were used. The participants were 586 elementary school students. The mean age was 11.01 years (SD 0.19), and 52.0% were girls. Based on Engel's biopsychosocial (BPS) model, biological factors (gender, physical health, and body mass index), psychological factors (mental health, acculturative stress, self-esteem, and general stress), and sociocultural factors (family economic status, social support, and parenting style) were measured and analyzed by using hierarchical multiple regression. In the final model, self-esteem (ß = 0.399, p < 0.001), parental social support (ß = 0.184, p < 0.001), and neglectful parenting style (ß = 0.085, p = 0.031) were positively related to children's life satisfaction, whereas general stress (ß = -0.213, p < 0.001) and acculturative stress (ß = -0.104, p = 0.002) were negatively related. The overall explanatory power was 41.7%. In conclusion, it is necessary to develop a specialized program that focuses on strengthening the bonds between parents and their children to enhance family functioning for multicultural families.

Mycorrhizal Fungal Diversity Associated with Six Understudied Ectomycorrhizal Trees in the Republic of Korea.

Mycorrhizal fungi are key components of forest ecosystems and play essential roles in host health. The host specificity of mycorrhizal fungi is variable and the mycorrhizal fungi composition for the dominant tree species is largely known but remains unknown for the less common tree species. In this study, we collected soil samples from the roots of six understudied ectomycorrhizal tree species from a preserved natural park in the Republic of Korea over four seasons to investigate the host specificity of mycorrhizal fungi in multiple tree species, considering the abiotic factors. We evaluated the mycorrhizal fungal composition in each tree species using a metabarcoding approach. Our results revealed that each host tree species harbored unique mycorrhizal communities, despite close localization. Most mycorrhizal taxa belonged to ectomycorrhizal fungi, but a small proportion of ericoid mycorrhizal fungi and arbuscular mycorrhizal fungi were also detected. While common mycorrhizal fungi were shared between the plant species at the genus or higher taxonomic level, we found high host specificity at the species/OTU (operational taxonomic unit) level. Moreover, the effects of the seasons and soil properties on the mycorrhizal communities differed by tree species. Our results indicate that mycorrhizal fungi feature host-specificity at lower taxonomic levels.

Global phylogeographical distribution of Gloeoporus dichrous.

Phylogeographic analyses are efficient in ecological and evolutionary studies to discover the origin of a lineage, its dispersal routes, and the divergence of ancestral traits. Studies on widespread wood-decay fungi have revealed the phylogenetic division of several polypores based on geographical distribution. In this study, specimens of Gloeoporus dichrous, a cosmopolitan polypore species, were collected globally and analyzed for their geographic distribution. Multi-marker Bayesian molecular clock and haplotype analyses revealed a clear division of G. dichrous populations by continent. The species diverged from its neighboring clades 10.3 (16.0-5.6) million years ago, with Asian and North American populations at the center of divergence. Possible dispersal mechanisms and pathways are predicted and discussed based on the evaluated transfer routes. The biogeography of G. dichrous analyzed in this study represents a fraction of the polypore evolution and may advance the understanding of the overall evolution of wood-decay fungi.

Qualitative metabolomics-based characterization of a phenolic UDP-xylosyltransferase with a broad substrate spectrum from Lentinus brumalis.

Wood-decaying fungi are the major decomposers of plant litter. Heavy sequencing efforts on genomes of wood-decaying fungi have recently been made due to the interest in their lignocellulolytic enzymes; however, most parts of their proteomes remain uncharted. We hypothesized that wood-decaying fungi would possess promiscuous enzymes for detoxifying antifungal phytochemicals remaining in the dead plant bodies, which can be useful biocatalysts. We designed a computational mass spectrometry-based untargeted metabolomics pipeline for the phenotyping of biotransformation and applied it to 264 fungal cultures supplemented with antifungal plant phenolics. The analysis identified the occurrence of diverse reactivities by the tested fungal species. Among those, we focused on O-xylosylation of multiple phenolics by one of the species tested, Lentinus brumalis. By integrating the metabolic phenotyping results with publicly available genome sequences and transcriptome analysis, a UDP-glycosyltransferase designated UGT66A1 was identified and validated as an enzyme catalyzing O-xylosylation with broad substrate specificity. We anticipate that our analytical workflow will accelerate the further characterization of fungal enzymes as promising biocatalysts.

Validation of Fuscoporia (Hymenochaetales, Basidiomycota) ITS sequences and five new species based on multi-marker phylogenetic and morphological analyses.

Although there is a continuous increase in available molecular data, not all sequence identities in public databases are always properly verified and managed. Here, the sequences available in GenBank for Fuscoporia (Hymenochaetales) were validated. Many morphological characters of Fuscoporia overlap among the species, emphasizing the role of molecular identification for accuracy. The identities of 658 Fuscoporia GenBank internal transcribed spacer (ITS) sequences were assessed using ITS phylogeny, revealing 109 (16.6%) misidentified and 196 (29.8%) unspecified sequences. They were validated and re-identified based on the research articles they were published in and, if unpublished, based on sequences from the type, type locality-derived sequences, or otherwise reliable sequences. To enhance the resolution of species delimitation, a phylogenetic assessment of a multi-marker dataset (ITS + nrLSU + rpb2 + tef1) was conducted. The multi-marker phylogeny resolved five of the twelve species complexes found in the ITS phylogeny and uncovered five new Fuscoporia species: F. dolichoseta, F. gilvoides, F. koreana, F. reticulata, and F. semicephala. The validated ITS sequences in this study may prevent further accumulation of misidentified sequences in public databases and contribute to a more accurate taxonomic evaluation of Fuscoporia species.

Reliability and Validity of the Korean Version of Lung Cancer Screening Health Belief Scale.

The purpose of this study was to verify the validity and reliability of the LCSHBS-K. This was a methodological study. The participants were adults aged between 50 and 74 years old, according to the selection criteria for lung cancer screening presented by the Comprehensive Cancer Network clinical practice guidelines in oncology recommendations. This study included 204 high-risk individuals who had not been diagnosed with lung cancer. The collected data were analyzed using the IBM SPSS Statistics software 26.0 version (IBM, New York, NY, USA). The reliability was analyzed by Cronbach's α for internal consistency, and the concurrent validity was analyzed by Pearson's correlation coefficients to identify the correlations with the health belief scale for Korean adults. To test the convergent validity, the average variance extracted (AVE) and composite reliability (CR) were calculated using confirmatory factor analysis. In addition, the model fit for a tool was CMIN (χ2/df), SRMR, RMSEA, GFI, and CFI as a comparative fit index. The discriminant validity was tested based on AVE > r2. The average age of the participants was 55.49 (SD = 5.07), the average smoking history was 29.55 (SD = 8.12) years, and the average number of cigarettes smoked per day was 12.18 (SD = 7.77). The goodness of fit met the criteria with GFI = 0.81 (criteria > 0.9), CMIN = 1.69 (criteria < 2), SRMR = 0.06 (criteria < 0.08), RMSEA = 0.058 (criteria < 0.06), and CFI = 0.91 (criteria > 0.9). The LCSHBS-K showed a statistically significant positive correlation with the HBS (r = 0.32 (p < 0.001)). Cronbach's α was 0.80 for all the items in the LCSHBS-K. Therefore, the validity and reliability of the LCSHBS-K tool were confirmed. Based on the results of this study, the Korean version of the LCSHBS tool was found to be suitable for screening lung cancer in high-risk groups in Korea.

Diversity of Cladosporium (Cladosporiales, Cladosporiaceae) species in marine environments and report on five new species.

Cladosporium species are cosmopolitan fungi, characterized by olivaceous or dark colonies with coronate conidiogenous loci and conidial hila with a central convex dome surrounded by a raised periclinal rim. Cladosporium species have also been discovered in marine environments. Although many studies have been performed on the application of marine originated Cladosporium species, taxonomic studies on these species are scarce. We isolated Cladosporium species from three under-studied habitats (sediment, seawater, and seaweed) in two districts including an intertidal zone in the Republic of Korea and the open sea in the Western Pacific Ocean. Based on multigenetic marker analyses (for the internal transcribed spacer, actin, and translation elongation factor 1), we identified fourteen species, of which five were found to represent new species. These five species were C.lagenariiformesp. nov., C.maltirimosumsp. nov., C.marinumsp. nov. in the C.cladosporioides species complex, C.snafimbriatumsp. nov. in the C.herbarum species complex, and C.marinisedimentumsp. nov. in the C.sphaerospermum species complex. Morphological characteristics of the new species and aspects of differences with the already known species are described herein together with molecular data.

Therapeutic effects of polydeoxyribonucleotide in an in vitro neuronal model of ischemia/reperfusion injury.

Polydeoxyribonucleotide (PDRN) is an agonist that selectively stimulates adenosine A2A receptor (ADORA2A), which suppresses inflammatory responses. Ischemia/reperfusion (I/R) injury plays a major role in the pathogenesis of ischemic stroke by inducing neuroinflammation. Therefore, this study aimed to investigate the therapeutic effects of PDRN in an in vitro I/R injury model. The in vitro model was established with differentiated Neuro-2a cells under oxygen and glucose deprivation condition. The cells were treated with PDRN for 24 h under reoxygenation condition. As the results of RNA-seq transcriptome analysis, CSF1, IL-6, PTPN6, RAC2, and STAT1 were identified of its relation to the effect of PDRN on inflammatory responses in the model. To further investigate therapeutic effects of PDRN, RT-qPCR, western blotting, LDH assay, and TUNEL assay were performed. PDRN significantly reversed the expression of genes and proteins related to inflammatory responses. The elevated ADORA2A expression by PDRN treatment downregulated JAK/STAT pathway in the model. Furthermore, PDRN inhibited neuronal cell death in the model. Consequently, our results suggested that PDRN alleviated inflammatory responses through inhibition of JAK/STAT pathway by mediating ADORA2A expression and inhibited neuronal cell death in the model. These results provide significant insights into potential therapeutic approaches involving PDRN treatment for I/R injury.

Fungal Catastrophe of a Specimen Room: Just One Week is Enough to Eradicate Traces of Thousands of Animals.

Indoor fungi obtain carbon sources from natural sources and even recalcitrant biodegradable materials, such as plastics and synthetic dye. Their vigorous activity may have negative consequences, such as structural damage to building materials or the destruction of precious cultural materials. The animal specimen room of the Seoul National University stocked 36,000 animal resources that had been well-maintained for over 80 years. Due to abandonment without the management of temperature and humidity during the rainy summer season, many stuffed animal specimens had been heavily colonized by fungi. To investigate the fungal species responsible for the destruction of the historical specimens, we isolated fungi from the stuffed animal specimens and identified them at the species level based on morphology and molecular analysis of the ß-tubulin (BenA) gene. A total of 365 strains were isolated and identified as 26 species in Aspergillus (10 spp.), Penicillium (14 spp.), and Talaromyces (2 spp.). Penicillium brocae and Aspergillus sydowii were isolated from most sections of the animal specimens and have damaged the feathers and beaks of valuable specimens. Our findings indicate that within a week of mismanagement, it takes only a few fungal species to wipe out the decades of history of animal diversity. The important lesson here is to prevent this catastrophe from occurring again through a continued interest, not to put all previous efforts to waste.

Diversity and Dynamics of Marine Arenicolous Fungi in Three Seasides of the Korean Peninsula.

Various arenicolous fungal species have been detected from the beach sand in the coastal area. However, little has been revealed regarding their distribution and dynamics. To investigate the overall diversity of marine arenicolous fungi (MAFs) in Korea and whether the composition of MAFs is affected by ocean currents, we isolated and analyzed the fungal community from the western, southern, and eastern seasides of the Korean Peninsula. In total, 603 strains were isolated and identified as 259 species based on appropriate molecular markers for each genus (ITS, BenA, CaM, tef1, and act). The composition of MAFs showed differences among the seasides. Our results indicate that many MAFs inhabit the beach sand on the Korean Peninsula, and the composition of MAFs is also affected by ocean currents flowing along each coast.

Diversity of Nigrospora (Xylariales, Apiosporaceae) Species Identified in Korean Macroalgae Including Five Unrecorded Species.

Nigrospora (Xylariales, Apiosporaceae) consists of species of terrestrial plant endophytes and pathogens. Nigrospora has also been reported in marine environments such as mangroves, sea fans, and macroalgae. However, limited research has been conducted on Nigrospora associated with macroalgae. Here, we isolated Nigrospora species from three types of algae (brown, green, and red algae) from Korean islands (Chuja, Jeju, and Ulleung) based on phylogenetic analyses of multigenetic markers: the internal transcribed spacers (ITS), beta-tubulin (BenA), and translation elongation factor 1 (TEF1-α). A total of 17 Nigrospora strains were isolated from macroalgae and identified as nine distinct species. The majority of Nigrospora species (seven) were found on brown algae, followed by red algae (three), and then green algae (two). To our understanding, this study represents the first account of N. cooperae, N. covidalis, N. guilinensis, N. lacticolonia, N. osmanthi, N. pyriformis, and N. rubi occurring in marine environments. Additionally, this study provides the first report of the occurrence of N. cooperae, N. covidalis, N. guilinensis, N. lacticolonia, and N. osmanthi in South Korea. This study will provide valuable insights for future research exploring the functions of fungi in macroalgal communities.

Two new species of Fistulina (Agaricales, Basidiomycota) from the Northern Hemisphere.

Phylogenetic and morphological analyses on samples of Fistulina from East Asia and North America were carried out, and two new species were described, namely, Fistulina americana and Fistulina orientalis, both previously known as Fistulina hepatica. The former is characterized by lateral stipitate basidiocarps, relatively small pores (7-8 per mm), a monomitic hyphal system with both clamp connections and simple septa, and ellipsoid basidiospores of 4-4.8 × 3-3.3 µm, and the species has been found on Quercus in North-East USA. F. orientalis is characterized by lateral stipitate basidiocarps, very small pores (11-12 per mm) with pruinose dissepiments, a monomitic hyphal system with both clamp connections and simple septa, and ovoid to subglobose basidiospores of 3-4 × 2.7-3 µm, and the species has been found on Castanopsis in East Asia. Phylogenetically, samples of F. americana and F. orientalis form two new lineages nested in the Fistulina clade.

Role of Perception, Health Beliefs, and Health Knowledge in Intentions to Receive Health Checkups among Young Adults in Korea.

Regular health checkups allow early treatment when problems occur and prevent disease progression, but the rate of health checkups among young adults is low. This study aimed to investigate the factors affecting the intentions to receive health checkups among young adults in their 20s in Korea. The study design was a descriptive cross-sectional study and examined their intentions to receive health checkups, their health beliefs (perceived sensitivity, perceived severity, perceived benefit, perceived barrier, cue to action, self-efficacy), their attitude toward health checkups, and their knowledge of health checkups. The participants were 252 adults in their 20s in South Korea who were eligible for national health checkups. The intentions to receive check-ups model identified five variables, including sex, perceived sensitivity, cue to action, self-efficacy, and attitudes toward health checkups, were as significant influencing factors for the intentions to receive health checkups with 51.0% explanatory power (F = 53.18, p < 0.001). Different approaches must be adopted according to past experiences with health checkups when attempting to improve the intentions to receive health checkups in young adults.

Fourteen Unrecorded Species of Agaricales Underw. (Agaricomycetes, Basidiomycota) from the Republic of Korea.

Agaricales species form pileate-stipitate fruiting bodies and play important roles in maintaining the terrestrial ecosystem as decomposers, symbionts, and pathogens. Approximately 23,000 Agaricales species have been known worldwide, and 937 species have been recorded in the Republic of Korea. However, most of them were identified solely based on morphological characteristics that often led to misidentifications. The specimens collected from 2018 to 2020 in the Republic of Korea were identified based on phylogenetic analysis of the internal transcribed spacer (ITS) sequences. Their identities were confirmed by microscopic characteristics. As a result, 14 Agaricales species were discovered for the first time in the Republic of Korea. They belonged to nine genera: Agaricus, Calocybe, Cortinarius, Hygrocybe, Inocybe, Lepista, Leucoagaricus, Marasmius, and Psathyrella. Detailed macroscopic and microscopic descriptions were provided to help distinguish these species. The morphological and molecular data provided in this study will serve as reliable references for the identification of Agaricales species.

Exploring fine-scale assembly of ectomycorrhizal fungal communities through phylogenetic and spatial distribution analyses.

Ectomycorrhizal fungi (EMF) form symbiotic relationship with the roots of host plants. EMF communities are composed of highly diverse species; however, how they are assembled has been a long-standing question. In this study, we investigated from a phylogenetic perspective how EMF communities assemble on Pinus densiflora seedlings at different spatial scales (i.e., seedling scale and root tip scale). P. densiflora seedlings were collected from different habitats (i.e., disturbed areas and mature forests), and their EMF communities were investigated by morphotype sequencing and next-generation sequencing (NGS). To infer assembly mechanisms, phylogenetic relatedness within the community (i.e., phylogenetic structure) was estimated and spatial distribution of EMF root tips was analyzed. The EMF communities on pine seedlings were largely different between the two habitats. Phylogenetically restricted lineages (Amphinema, /suillus-rhizopogon) were abundant in the disturbed areas, whereas species from diverse lineages were abundant in the mature forests (Russula, Sebacina, /tomentella-thelephora, etc.). In the disturbed areas, phylogenetically similar EMF species were aggregated at the seedling scale, suggesting that disturbance acts as a powerful abiotic filter. However, phylogenetically similar species were spatially segregated from each other at the root tip scale, indicating limiting similarity. In the mature forest seedlings, no distinct phylogenetic signals were detected at both seedling and root tip scale. Collectively, our results suggest that limiting similarity may be an important assembly mechanism at the root tip scale and that assembly mechanisms can vary across habitats and spatial scales.

Taxonomic study of Collybiopsis (Omphalotaceae, Agaricales) in the Republic of Korea with seven new species.

Collybiopsis is a genus of the gymnopoid/marasmioid complex of the family Omphalotaceae. The classification system of Collybiopsis has recently undergone large changes through molecular approaches. The new classification system has not been applied for Collybiopsis in the Republic of Korea, and general research on this genus was also lacking. In this study, we analyzed the Collybiopsis species in the Republic of Korea by assessing all gymnopoid/marasmioid specimens collected nationwide for ten years by combining morphological approaches and multilocus (ITS + nrLSU) phylogenetic analysis. We thus confirmed that 16 species of Collybiopsis are present in the Republic of Korea, including two previously unreported species (Co.nonnulla and Co.dichroa) and seven new species (Co.albicantipes sp. nov., Co.clavicystidiata sp. nov., Co.fulva sp. nov., Co.orientisubnuda sp. nov., Co.subumbilicata sp. nov., Co.undulata sp. nov., and Co.vellerea sp. nov.). A thorough examination of the Collybiopsis suggested that it is difficult to distinguish or identify the species based on morphological characteristics only; a combined molecular approach is needed for accurate identification. The Collybiopsis database of the Republic of Korea is updated, and information on the new species is provided. Five new combinations from Marasmiellus to Collybiopsis are also proposed (Co.istanbulensis comb. nov., Co.koreana comb. nov., Co.omphalodes comb. nov., Co.pseudomphalodes comb. nov., and Co.ramuliciola comb. nov.).

Taxonomic evaluation of Xylodon (Hymenochaetales, Basidiomycota) in Korea and sequence verification of the corresponding species in GenBank.

Genus Xylodon consists of white-rot fungi that grow on both angiosperms and gymnosperms. With resupinate and adnate basidiomes, Xylodon species have been classified into other resupinate genera for a long time. Upon the integration of molecular assessments, the taxonomy of the genus has been revised multiple times over the years. However, the emendations were poorly reflected in studies and public sequence databases. In the present study, the genus Xylodon in Korea was evaluated using molecular and morphological analyses of 172 specimens collected in the period of 2011 to 2018. The host types and geographical distributions were also determined for species delimitation. Furthermore, public sequences that correspond to the Xylodon species in Korea were assessed to validate their identities. Nine Xylodon species were identified in Korea, with three species new to the country. Morphological differentiation and identification of some species were challenging, but all nine species were clearly divided into well-resolved clades in the phylogenetic analyses. Detailed species descriptions, phylogeny, and a key to Xylodon species in Korea are provided in the present study. A total of 646 public ITS and nrLSU sequences corresponding to the nine Xylodon species were found, each with 404 (73.1%) and 57 (61.3%) misidentified or labeled with synonymous names. In many cases, sequences released before the report of new names have not been revised or updated. Revisions of these sequences are arranged in the present study. These amendments may be used to avoid the misidentification of future sequence-based identifications and concurrently prevent the accumulation of misidentified sequences in GenBank.