Nano-Micro Letters

The genus Pseudogymnoascus includes several species frequently isolated from extreme environments worldwide, including cold environments such as Antarctica. This study describes three new species of Pseudogymnoascus—P. russussp. nov., P. irelandiaesp. nov., and P. ramosussp. nov.—isolated from Antarctic soils. These species represent the first Pseudogymnoascus taxa to be formally described from Antarctic soil samples, expanding our understanding of fungal biodiversity in this extreme environment. Microscopic descriptions of asexual structures from living cultures, along with measurements of cultural characteristics and growth on various media types at different temperatures, identify three distinct new species. In addition, phylogenetic analyses based on five gene regions (ITS, LSU, MCM7, RPB2, TEF1) and whole-genome proteomes place these new species within three distinct previously described clades: P. irelandiae in clade K, P. ramosus in clade Q, and P. russus in clade B. These results provide further evidence of the extensive undescribed diversity of Pseudogymnoascus in high-latitude soils. This study contributes to the growing body of knowledge on Antarctic mycology and the broader ecology of psychrophilic and psychrotolerant fungi.

Arbuscular Mycorrhizal (AM) symbiosis is integral to sustainable agriculture and enhances plant resilience to abiotic and biotic stressors. Through their symbiotic association with plant roots, AM improves nutrient and water uptake, activates antioxidant defenses, and facilitates hormonal regulation, contributing to improved plant health and productivity. Plants release strigolactones, which trigger AM spore germination and hyphal branching, a process regulated by genes, such as D27, CCD7, CCD8, and MAX1. AM recognition by plants is mediated by receptor-like kinases (RLKs) and LysM domains, leading to the formation of arbuscules that optimize nutrient exchange. Hormonal regulation plays a pivotal role in this symbiosis; cytokinins enhance AM colonization, auxins support arbuscule formation, and brassinosteroids regulate root growth. Other hormones, such as salicylic acid, gibberellins, ethylene, jasmonic acid, and abscisic acid, also influence AM colonization and stress responses, further bolstering plant resilience. In addition to plant health, AM enhances soil health by improving microbial diversity, soil structure, nutrient cycling, and carbon sequestration. This symbiosis supports soil pH regulation and pathogen suppression, offering a sustainable alternative to chemical fertilizers and improving soil fertility. To maximize AM ’s potential of AM in agriculture, future research should focus on refining inoculation strategies, enhancing compatibility with different crops, and assessing the long-term ecological and economic benefits. Optimizing AM applications is critical for improving agricultural resilience, food security, and sustainable farming practices.

Based on molecular and morphological evidence the new subfamily Pseudobaeosporoideae of the Tricholomataceae is established within the Tricholomatineae for accommodating the unique features of Pseudobaeospora such as gymnocarpic mycenoid/collybioid habit, small-sized spores with thick and dextrinoid wall, and presence of crassobasidia. Twenty-six Pseudobaeospora collections corresponding to eleven species (five types) were newly sequenced. Collections morphologically attributable to P. oligophylla (type of the genus) or to P. pillodii are here sequenced for the first time: accordingly, P. oligophylla is considered as a posterior synonym of P. pillodii. Quélet’s original plate is selected as a lectotype for Collybia pillodii and a French collection as its epitype collection. Pseudobaeospora deceptiva is described as a new species from Italy very close to P. pillodii from which it differs mainly by bigger spores and SSU and LSU rDNA sequences. The presence of P. pyrifera in Italy is documented for the first time and P. mutabilis is reduced to its later synonym. A neotype is established for P. jamonii which is here proved to be an independent species. Finally, a critical review of the characters used for interspecific distinctions in Pseudobaeospora was provided.

Arabica coffee (Coffea arabica) is the most cultured and popular coffee bean in today’s world. Yunnan Province is well known as China’s largest arabica coffee cultivation region. Fungi represent an important group of microorganisms associated with coffee, profoundly influencing its yield and quality. In this study, twelve fungal collections growing on dead and decaying twigs of coffee were collected and isolated to systematically document microfungi associated with coffee plants in Yunnan Province. Ten novel species, each representing a unique family within Pleosporales, were identified and introduced, based on comprehensive morphological analyses and multigene phylogenetic studies. The ten new species belong to the families Bambusicolaceae, Didymellaceae, Didymosphaeriaceae, Longiostiolaceae, Lophiostomataceae, Massarinaceae, Neomassariaceae, Occultibambusaceae, Roussoellaceae and Thyridariaceae with each family containing one new species. Macro- and micro-characteristics, descriptions and phylogenetic trees indicating the placement of the new taxa are provided. In addition, pairwise homoplasy index (PHI) test results and morphological comparisons between the new species and closely-related taxa are given. This study also establishes a comprehensive global inventory of saprobic fungi associated with coffee, which is intended to help researchers and professionals worldwide with practical information. This research enhances the understanding of coffee-associated fungal diversity in China and underscores the importance of introducing new saprobic fungal taxa related to coffee.

Fusarium species, recognised as global priority pathogens, frequently induce severe diseases in crops; however, certain species exhibit alternative symbiotic lifestyles and are either non-pathogenic or endophytic. In this study, we characterised the mutualistic relationship between the eFp isolate of F. pseudograminearum and five poplar species, resulting in formation root structures reminiscent of ectomycorrhizal (ECM) symbiosis. This functional symbiosis is evidenced by enhanced plant growth, reciprocal nutrient exchange, improved nitrogen and phosphorus uptake and upregulation of root sugar transporter gene expression (PtSweet1). Comparative and population genomics confirmed that eFp maintains a structurally similar genome, but exhibits significant divergence from ten conspecific pathogenic isolates. Notably, eFp enhanced the growth of diverse plant lineages (Oryza, Arabidopsis, Pinus and non-vascular liverworts), indicating a near-complete loss of virulence. Although this specialised symbiosis has only been established in vitro, it holds significant value in elucidating the evolutionary track from endophytic to mycorrhizal associations.

Natural product discovery from fungi for drug development and description of novel chemistry has been a tremendous success. This success is expected to accelerate even further, owing to the advent of sophisticated technical advances of technical advances that recently led to the discovery of an unparalleled biodiversity in the fungal kingdom. This review aims to give an overview on i) important secondary metabolite-derived drugs or drug leads, ii) discuss the analytical and strategic framework of how natural product discovery and drug lead identification transformed from earlier days to the present, iii) how knowledge of fungal biology and biodiversity facilitates the discovery of new compounds, and iv) point out endeavors in understanding fungal secondary metabolite chemistry in order to systematically explore fungal genomes by utilizing synthetic biology. An outlook is given, underlining the necessity for a collaborative and cooperative scenario to harness the full potential of the fungal secondary metabolome.

Diaporthales is a significant fungal order comprising species that predominantly inhabit plant tissues, being pathogens, endophytes, and saprobes. Recent studies have uncovered extensive species diversity across various hosts, utilizing both morphological characteristics and molecular phylogenetic analyses. In this study, samples of leaf spots and branch cankers were collected from China, and fungal isolations were established. Species identification was conducted using a phylogenetic approach based on combined sequence data from the internal transcribed spacer (ITS) region, large subunit ribosomal DNA (LSU), the DNA-directed RNA polymerase II second largest subunit (rpb2), and translation elongation factor 1-alpha (tef1) genes, together with morphological observations. As a result, the novel genus Tiania is proposed, with three newly described species: T. chinensis, T. lithocarpicola, and T. quercicola. These species are validated by pairwise homoplasy index (PHI) analysis, ensuring robust support for their distinction. This study explores the rare family Diaporthostomataceae, providing the first descriptions of their anamorphic forms. By offering detailed morphological and molecular data, this research lays a foundation for future taxonomic and systematic studies of the Diaporthales.

In this study, the complete mitogenomes of three Diaporthe species (Diaporthe eres ZM79-3, D. phaseolorum ZM33-4 and Diaporthe sp. ZM41-5) were sequenced, assembled and compared with the other three previously sequenced Diaporthe mitogenomes (D. caulivora VNIIKR SE Dcaul3, D. longicolla MSPL 10-6 and D. sojae VNIIKR SE Dps12). The six Diaporthe mitogenomes were found to be circular DNA molecules, with lengths ranging from 53,646 bp to 108,865 bp. The mitogenomes of the six Diaporthe species mainly comprised the same set of 15 core protein-coding genes (PCGs), two rRNAs, and a certain number of tRNAs and unidentified open reading frames (ORFs). The PCG length, AT skew and GC skew showed large variability among the 15 PCGs in the six mitogenomes. The nad1 gene had the least K2P genetic distance of the 15 core PCGs among the 13 Diaporthales species, indicating that this gene was highly conserved. The Ka/Ks values for all 15 core PCGs were < 1, suggesting that these genes were all subject to purifying selection. Comparative mitogenome analysis showed that introns contributed the most to the size variation of Diaporthe mitogenomes. Frequent intron loss/gain events were detected to have occurred in the cox1 gene during the evolution of the Diaporthales mitogenomes. Although the mitogenomes of 13 species from Diaporthales had undergone large-scale gene rearrangements, six mitogenomes of Diaporthe species had identical gene arrangements. Phylogenetic analysis based on combined mitochondrial gene datasets showed that the six Diaporthe species formed well-supported topologies. To our knowledge, this study is the first report on the mitogenomes of D. phaseolorum ZM33-4 and Diaporthe sp. ZM41-5, as well as the first comparison of mitogenomes among Diaporthe species. Our findings will further promote investigations of the genetics, evolution and phylogeny of the Diaporthe species.

Pleosporales , the largest order in Dothideomycetes, has a broad host range and inhabits host plants as epiphytes, endophytes, parasites and saprophytes. Trematosphaeriaceae is a monophyletic family in Pleosporales, composed of species of deviated ecological background and morphological traits. In this study, we described a new fungal taxon under Trematosphaeriaceae, based on root endophytic fungi recovered from the desert plant Gymnocarpos przewalskii in Gansu Province, China. The taxon is characterised by simple, aseptate conidia and pycnidia in unusually small sizes. Multilocus phylogenetic analysis, based on ITS, LSU, SSU and TEF sequences and a morphology study indicated that the taxon represented a new genus within the Trematosphaeriaceae and was named Nigromargarita tarda. Intriguingly, an intron of 355 bp in length located at site 453 on the ribosomal SSU gene was detected in one strain of N. tarda. Sequence analysis and phylogenetic analysis indicated that the intron belongs to an intron position class (Pcl) restricted to Pleosporales. Phylogeny affiliated distribution of this Pcl was confined at the genus or lower level, suggesting a horizontal transmission pattern of this Pcl. This study established a new genus in Trematosphaeriaceae and depicted the spread features of a less-documented Pcl amongst Pleosporales families with high resolution, which promotes our understanding of the origin and transmission mechanism of such mobile genetic elements.

The evolutionary history of crop pathogens is shaped by a complex interaction of natural and anthropogenic factors. The fungus Colletotrichum graminicola causes maize anthracnose which results in significant yield losses worldwide. We conducted a comprehensive investigation into the evolutionary genomics of C. graminicola using a collection of 212 isolates from 17 countries across five continents. Genomic analyses supported the existence of three geographically isolated genetic lineages, with a significant pattern of isolation by distance. We identified two distinct gene flow patterns, driven by short- and long-distance dispersal, likely resulting from the natural spread of the pathogen and the exchange of contaminated seeds. We present evidence of genetic introgression between lineages, suggesting a long history of recombination. We identified significant recombination events coalescing at distinct points in time, with the North American lineage displaying evidence of the most ancient recombination. Demographic modelling has indicated that North America is an intermediate between Brazil, Europe and an ancestral, unsampled source population, which is hypothesised to be Mesoamerican. Our analyses revealed that the global genomic structure of C. graminicola is shaped by geographic differentiation driven by long-distance migration and a long history of recombination and introgression. We show historical relationships amongst these lineages, identifying a potential route for fungal spread, with the North American population emerging ancestrally, followed sequentially by the Brazilian and European populations. Our research indicates that the European lineage is more virulent, which has implications for the potential emergence of new outbreaks of maize anthracnose in Europe.

Morchella species have considerable significance in terrestrial ecosystems, exhibiting a range of ecological lifestyles along the saprotrophism-to-symbiosis continuum. However, the mitochondrial genomes of these ascomycetous fungi have not been thoroughly studied, thereby impeding a comprehensive understanding of their genetic makeup and ecological role. In this study, we analysed the mitogenomes of 30 Morchellaceae species, including yellow, black, blushing and false morels. These mitogenomes are either circular or linear DNA molecules with lengths ranging from 217 to 565 kbp and GC content ranging from 38% to 48%. Fifteen core protein-coding genes, 28–37 tRNA genes and 3–8 rRNA genes were identified in these Morchellaceae mitogenomes. The gene order demonstrated a high level of conservation, with the cox1 gene consistently positioned adjacent to the rnS gene and cob gene flanked by apt genes. Some exceptions were observed, such as the rearrangement of atp6 and rps3 in Morchella importuna and the reversed order of atp6 and atp8 in certain morel mitogenomes. However, the arrangement of the tRNA genes remains conserved. We additionally investigated the distribution and phylogeny of homing endonuclease genes (HEGs) of the LAGLIDADG (LAGs) and GIY-YIG (GIYs) families. A total of 925 LAG and GIY sequences were detected, with individual species containing 19–48HEGs. These HEGs were primarily located in the cox1, cob, cox2 and nad5 introns and their presence and distribution displayed significant diversity amongst morel species. These elements significantly contribute to shaping their mitogenome diversity. Overall, this study provides novel insights into the phylogeny and evolution of the Morchellaceae.

Shiraia-related species are well-known bambusicolous fungi in Dothideomycetes class, with high value in traditional medicine for producing hypocrellin, as an anticipated photosensitiser. The complete mitogenomes of hypocrellin-producing Pseudoshiraia conidialis strains were analysed in the present study, with functional gene variations through comparative genomics and transcriptomics. Five strains (ZZZ816, CNUCC1353PR, JAP103846, CNUCC C72, CNUCC C151) were sequenced, which indicated similar genome characteristics. Two of them possess an extra atp6 gene, and the associated variable fragment “HSP1-HSP2-atp6_2” correlates closely with hypocrellin production capacity. Therefore, these five strains were divided into three groups: ZZZ816 and CNUCC1353PR possessing high production efficiency, CNUCC C72 and JAP103846 with low yield and CNUCC C151 as a transition type. The gene expression changes were screened under various conditions. ZZZ816-related species showed significant changes in mitochondrial genes, especially HSP1, HSP2 and atp6_2, linked closely to hypocrellin synthesis and stress response; rps3 expression also consistently correlated with hypocrellin production. JAP103846 group showed a stable expression pattern divergently, except for rps3 suppression by blue light. These findings would provide new insights into secondary metabolite regulation and ROS resistance. Above all, this study conducted the comprehensive analysis of Shiraia-like fungi mitogenomes and functional gene expression, which can update the understanding of fungal evolution and potential for improved hypocrellin production.

Turf-grasses are economically important horticultural crops, which have been utilised by humans to improve the environment for more than a thousand years. Turf-grasses are widely distributed in landscapes, slopes and sport fields, such as golf courses. Endophytic fungi are a resource of unexplored fungal diversity with potential bioactive compounds. In this study, culture-independent ITS amplicon sequencing and culture-dependent isolation methods were used to reveal fungal community in roots of the turf-grass Zoysia japonica. A total of 317 OTUs were identified from root samples of Z. japonica by analysis of ITS amplicon reads. Fungal community was dominated by Sordariales (32.45%), followed by Chaetothyriales (18.16%), unknown taxa in Sordariomycetes (14.63%) and Pleosporales (12.48%). During isolation, 151 endophytic fungal strains were obtained from roots of Z. japonica and a variety of taxa were found by ITS amplification and sequencing. Moreover, 11 endophytic fungal species were further characterised in this study, based on morphological characterisation and multi-loci phylogenetic analysis, including Niesslia dimorphospora, a newly-recorded species in Korea and 10 novel species (Dactylaria hwasunensissp. nov., Lophiostoma jeollanense sp. nov., Magnaporthiopsis zoysiaesp. nov., Poaceascoma endophyticumsp. nov., P. koreanumsp. nov., P. magnumsp. nov., P. zoysiiradicicolasp. nov., Stagonospora endophytica sp. nov., Setophoma zoysiaesp. nov. and Pseudorhypophila poaesp. nov.). Antifungal activities of these species were tested against the turf-grass brown patch pathogen Rhizoctonia solani AG2-2(IIIB), with S. zoysiae being the best antagonist. In addition, butanol extract from mycelia of S. zoysiae strongly inhibited R. solani AG2-2(IIIB) in vitro and in planta. The results of this study expand the biodiversity of endophytic fungi and revealed potential biological resources for future turf-grass management and bioactive compound exploitation.

Aster tataricus is a plant used in Traditional Chinese Medicine. From its roots, we isolated four endophytic fungi strains. After mass spectrometry analysis and subsequent molecular networking and dereplication, one of the strain’s extracts showed a cluster of yet undescribed natural products. Additionally, the extract was found to be lethal for the nematode Caenorhabditis elegans and cytotoxic against eukaryotic cell lines. The fungal strain was characterized by morphological and molecular studies, allowing its description as a new species in the genus Tengochaeta (Chaetomiaceae), Tengochaeta bulbillosa. After cultivation and extraction of the strain, the major secondary metabolites were isolated. Structure elucidation based on nuclear magnetic resonance spectroscopy and high-resolution tandem mass spectrometry revealed these compounds to be five new azaphilones. Additionally, the localization of these azaphilones in the host plant was studied by mass spectrometry imaging of different plant tissues, revealing that they were mainly localized in the aerial parts of the plant. The main compound, bulbillosin A, was evaluated for its activity against sixty cancer cell lines, revealing a differential cytotoxicity profile.

Foliicolous lichens grow on living leaves of vascular plants. They are mostly found in tropical to subtropical or temperate rainforests. Many phenotype-based species are considered as pantropical or even sub-cosmopolitan, either attributed to old ages, having existed prior to continental breakups or long-distance dispersal. We built a much expanded, global phylogeny of Gomphillaceae, the most diverse group of leaf-dwelling lichenised fungi. Our sampling encompassed six major biodiversity hotspots: MIOI (Madagascar and the Indian Ocean Islands), the Caribbean, New Caledonia, the Colombian Chocó, Mesoamerica and the Atlantic coast of Brazil. It was based on multilocus sequence data (mtSSU rDNA, nuLSU rDNA and RPB1), including 2207 sequences of 1256 specimens. Species delimitation methods combined with a phenotype matrix identified 473 putative species. Amongst these, 104 are confirmed as described, 213 are classified as cryptic or near cryptic (hidden diversity), 100 represent new species to science (identified on the basis of phenotype) and 56 remain unidentified. Amongst the 104 species with a valid name, 40.5% are distributed across 2–5 continents (lichenogeographical regions) by applying the phenotype-based species concept. However, using the integrative approach to delineate species, this estimate is reduced to 9%. We estimate the global species richness of Gomphillaceae at 1,861–2,356 species. The timing of species-level divergences suggests that the current distribution of foliicolous lichens is shaped more by long-distance dispersal and rapid diversification than by vicariance. The origin of the family and major clades appears to be in the Neotropics, with subsequent numerous dispersal events. Our results support the separation of three major lineages, corresponding to the former families Asterothyriaceae, Gomphillaceae s.str. and Solorinellaceae, which should be recognised at the subfamily level.