Morphology and multigene phylogeny reveal four new Xylaria (Xylariales, Xylariaceae) species from karst region in China.

This study presents the identification of four novel Xylaria species, discovered in the karst region of China. The discovery was facilitated by a rigorous analysis that encompassed both morpho-anatomical features and multi-locus phylogenetics utilizing sequences from the ITS, rpb2, and TUB2 loci. The newly identified species are designated as Xylariajichuanii sp. nov., X.nanningensis sp. nov., X.orientalis sp. nov., and X.taiyangheensis sp. nov. The distinction of these species from their known counterparts was verified through comparison of morphological features and phylogenetic analysis. The study further provides detailed morphological descriptions, illustrative representations, and a phylogenetic tree, all of which contribute to the taxonomic positioning of these novel species.

 Stromatolinea, a new diatrypaceous fungal genus (Ascomycota, Sordariomycetes, Xylariales, Diatrypaceae) from China.

Molecular phylogeny and morphological characteristics of collections of diatrypaceous fungi from Guizhou Province, China, lead to the establishment of a new genus, Stromatolinea, and the identification of four new species and two new combinations. The taxa were found growing on the dead culms of Phyllostachys bamboo. The new genus is distinguished by its well-developed, discrete linear stromata with yellow interior tissue and allantoid subhyaline ascospores. The newly described species are Stromatolineagrisea, S.guizhouensis, S.hydei, and S.xishuiensis. Additionally, two new combinations, Stromatolinealinearis and S.phaselina, are proposed based on comparative analysis and morphology. Phylogenetic analyses were conducted using ITS and TUB2 sequences. The study includes comprehensive morphological descriptions, illustrations, and a phylogenetic tree depicting the placement of the new taxa.

New insights into decoding the lifestyle of endophytic Fusarium lateritium Fl617 via comparing genomes.

Fungal-plant interactions have persisted for 460 million years, and almost all terrestrial plants on Earth have endophytic fungi. However, the mechanism of symbiosis between endophytic fungi and host plants has been inconclusive. In this dissertation, we used a strain of endophytic Fusarium lateritium (Fl617), which was found in the previous stage to promote disease resistance in tomato, and selected the pathogenic Fusarium oxysporum Fo4287 and endophytic Fusarium oxysporum Fo47, which are in the same host and the closest relatives of Fl617, to carry out a comparative genomics analysis of the three systems and to provide a new perspective for the elucidation of the special lifestyle of the fungal endophytes. We found that endophytic F. lateritium has a smaller genome, fewer clusters and genes associated with pathogenicity, and fewer plant cell wall degrading enzymes (PCWDEs). There were also relatively fewer secondary metabolisms and typical Fusarium spp. toxins, and a lack of the key Fusarium spp. pathogenicity factor, secreted in xylem (SIX), but the endophytic fungi may be more sophisticated in their regulation of the colonization process. It is hypothesized that the endophytic fungi may have maintained their symbiosis with plants due to the relatively homogeneous microenvironment in plants for a long period of time, considering only plant interactions and discarding the relevant pathogenicity factors, and that their endophytic evolutionary tendency may tend to be genome streamlining and to enhance the fineness of the regulation of plant interactions, thus maintaining their symbiotic status with plants.

Erratum: Corrigendum: Hu H et al. (2023) Taxonomic and phylogenetic characterisations of six species of Pleosporales (in Didymosphaeriaceae, Roussoellaceae and Nigrogranaceae) from China. MycoKeys 100: 123-151. https://doi.org/10.3897/mycokeys.100.109423.

[This corrects the article DOI: 10.3897/mycokeys.100.109423.].

Novel drimane-type sesquiterpenoids and nucleosides from the Helicoma septoconstrictum suppress the growth of ovarian cancer cells.

Four new drimane-type sesquiterpenoids and two new nucleoside derivatives (1-6), were isolated from the fungus Helicoma septoconstrictum. Their structures were determined based on the combination of the analysis of their HR-ESI-MS, NMR, ECD calculations data and acid hydrolysis. All the isolated compounds were detected for their bio-activities against MDA-MB-231, A549/DDP, A2780 and HepG2 cell lines. Helicoside C (4) exhibited superior cytotoxicity against the A2780 cell line with IC50 7.5 ± 1.5 µM. The analysis of reactive oxygen species (ROS) revealed that Helicoside C induced an increase in intracellular ROS. Furthermore, the flow cytometry and mitochondrial membrane potential (MMP) analyses unveiled that Helicoside C mediated mitochondrial-dependent apoptosis in A2780 cells. The western blotting test showed that Helicoside C could suppress the STAT3's phosphorylation. These findings offered crucial support for development of H. septoconstrictum and highlighted the potential application of drimane-type sesquiterpenoids in pharmaceuticals.

AaLaeA targets AaFla1 to mediate the production of antitumor compound in Alternaria alstroemeria.

Endophytic fungi are an important source of novel antitumor substances. Previously, we isolated an endophytic fungus, Alternaria alstroemeria, from the medicinal plant Artemisia artemisia, whose crude extracts strongly inhibited A549 tumor cells. We obtained a transformant, namely AaLaeAOE26 , which completely loses its antitumor activity due to overexpression of the global regulator AaLaeA. Re-sequencing analysis of the genome revealed that the insertion site was in the noncoding region and did not destroy any other genes. Metabolomics analysis revealed that the level of secondary antitumor metabolic substances was significantly lower in AaLaeAOE26 compared with the wild strain, in particular flavonoids were more downregulated according to the metabolomics analysis. A further comparative transcriptome analysis revealed that a gene encoding FAD-binding domain protein (Fla1) was significantly downregulated. On the other hand, overexpression of AaFla1 led to significant enhancement of antitumor activity against A549 with a sevenfold higher inhibition ratio than the wild strain. At the same time, we also found a significant increase in the accumulation of antitumor metabolites including quercetin, gitogenin, rhodioloside, liensinine, ginsenoside Rg2 and cinobufagin. Our data suggest that the global regulator AaLaeA negatively affects the production of antitumor compounds via controlling the transcription of AaFla1 in endophytic A. alstroemeria.

Taxonomic and phylogenetic characterisations of six species of Pleosporales (in Didymosphaeriaceae, Roussoellaceae and Nigrogranaceae) from China.

Pleosporales comprise a diverse group of fungi with a global distribution and significant ecological importance. A survey on Pleosporales (in Didymosphaeriaceae, Roussoellaceae and Nigrogranaceae) in Guizhou Province, China, was conducted. Specimens were identified, based on morphological characteristics and phylogenetic analyses using a dataset composed of ITS, LSU, SSU, tef1 and rpb2 loci. Maximum Likelihood (ML) and Bayesian analyses were performed. As a result, three new species (Neokalmusiakarka, Nigrogranaschinifolium and N.trachycarpus) have been discovered, along with two new records for China (Roussoellaneopustulans and R.doimaesalongensis) and a known species (Roussoellapseudohysterioides). Morphologically similar species and phylogenetically close taxa are compared and discussed. This study provides detailed information and descriptions of all newly-identified taxa.

Morphophylogenetic evidence reveals four new fungal species within Tetraplosphaeriaceae (Pleosporales, Ascomycota) from tropical and subtropical forest in China.

Tetraplosphaeriaceae (Pleosporales, Ascomycota) is a family with many saprobes recorded from various hosts, especially bamboo and grasses. During a taxonomic investigation of microfungi in tropical and subtropical forest regions of Guizhou, Hainan and Yunnan provinces, China, several plant samples were collected and examined for fungi. Four newly discovered species are described based on morphology and evolutionary relationships with their allies inferred from phylogenetic analyses derived from a combined dataset of LSU, ITS, SSU, and tub2 DNA sequence data. Detailed illustrations, descriptions and taxonomic notes are provided for each species. The four new species of Tetraplosphaeriaceae reported herein are Polyplosphaeriaguizhouensis, Polyplosphaeriahainanensis, Pseudotetraploayunnanensis, and Tetraploahainanensis. A checklist of Tetraplosphaeriaceae species with available details on their ecology is also provided.

Application potential of biofertilizer-assisted Pennisetum giganteum in safe utilization of mercury-contaminated paddy fields.

High mercury (Hg) bioaccumulation in crops such as rice in Hg-contaminated areas presents a potential health hazard to humans and wildlife. To develop a safe alternative technique, bacillus-inoculated biofertilizer, citric acid, earthworms, and selenium-modified activated clay were compared for their ability to regulate Hg bioaccumulation in Pennisetum giganteum (P. giganteum). This biofertilizer significantly increased Bacillus sp. abundance in the soil by 157.12%, resulting in the removal of 27.52% of water-soluble Hg fractions through volatilization and adsorption mechanisms. The variation in bioavailable Hg in the soil significantly reduced the total Hg concentration in P. giganteum young leaves, old leaves, stems, and roots of P. giganteum by 74.14%, 48.08%, 93.72%, and 50.91%, respectively (p < 0.05), which is lower than the Chinese feed safety standard (100 ng g-1). The biofertilizer inhibitory potential was highly consistent with that of the selenium-modified activated clay. Biofertilizers significantly reduced the methylmercury concentration in various P. giganteum tissues (p < 0.05), whereas selenium-modified activated clay failed to achieve a comparable effect. This biofertilizer-assisted planting pattern can achieve an economic income quadruple that of the rice planting pattern in the Hg-contaminated paddy fields. Because of its significant environmental and financial applications, the biofertilizer-assisted planting pattern is expected to replace Hg-contaminated paddy fields.

Nanoemulsion of the Essential Oil from Blumea balsamifera (L.) DC. and Its Effect on Trauma Repair.

The essential oil, extracted from the Hmong medicine Blumea balsamifera (L.) DC. (BBO), is a purely natural wound repair agent. Its application has, however, been restricted due to its low solubility and high volatility properties. In this study, we have developed a nanoemulsion formulation to improve the characteristics of BBO. The particle size of the nanoemulsion was normally distributed, and 71% of its range was concentrated between 10-100 nm, with an average particle size of 62.8 nm and an encapsulation rate of 98%. After 7 days of application, the wound healing rate of the BBO nanoemulsion (BBO-NE) group was 1.5 times higher than that of the normal BBO group. Along with histological observations, nanoemulsion formulation has been demonstrated to significantly improve the efficacy of BBO for wound repair. In addition, inflammation-related TLR4, CD14 and IRAK-1 gene transcript levels were significantly reduced after the administration of BBO-NE compared to the BBO group, with downregulation of 47.8%, 35.7% and 57.8%, respectively, while the secretion of pro-inflammatory factors IL-6 and TNF-α was also significantly reduced by 83.8% and 32.7%, respectively, in the nanoformulation administration (BBO-NE) group compared to the BBO group. In contrast, the anti-inflammatory factor IL-10 was significantly increased by 4.2-fold. It was further found that the drug penetration per unit area increased significantly 6.30% to 19.5% at different time points after the application of the BBO-NE compared to the BBO. In conclusion, nano-formulation enhanced the drug penetration of the BBO, reduced inflammatory factors, increased the level of anti-inflammatory factors, and promoted collagen deposition, thereby accelerating wound repair.

Endophytic fungus Biscogniauxia petrensis produces antibacterial substances.

Widespread drug resistance and limited antibiotics challenge the treatment of pathogenic bacteria, which leads to a focus on searching for new antimicrobial lead compounds. We found the endophytic fungus Biscogniauxia petrensis MFLUCC14-0151 from the medicinal plant Dendrobium harveyanum had antibacterial activity for the first time. This work aimed to reveal the capacity of Biscogniauxia petrensis MFLUCC14-0151 against foodborne pathogenic bacteria and identify its bioactive substances. Bioassay-guided isolation led to the discovery of six infrequent active monomers, including (10R)-Xylariterpenoid B (1), Xylariterpenoid C (2), Tricycloalternarene 1b (3), Tricycloalternarene 3b (4), Funicin (5) and Vinetorin (6) from MFLUCC14-0151 for the first time. The results of antibacterial tests showed that (10R)-Xylariterpenoid B and Xylariterpenoid C exhibited inhibitory activities against Streptococcus agalactiae with MIC values ranging from 99.21 to 100.00 µM, and against Streptococcus aureus with MIC values ranging from 49.60 to 50.00 µM. Tricycloalternarene 1b and Tricycloalternarene 3b showed inhibitory effects on Streptococcus agalactiae with MIC values ranging from 36.13 to 75.76 µM. Unexpectedly, Funicin and Vinetorin exhibited remarkable antagonistic activities against Streptococcus agalactiae with MIC values of 10.35 and 10.21 µM, respectively, and against Streptococcus aureus with MIC values of 5.17 and 20.42 µM, respectively. In conclusion, we suggest that the isolated compounds Funicin and Vinetorin may be promising lead compounds for natural antibacterial agents.

Two new fungal genera (Diaporthales) found on Dipterocarpaceae in Thailand.

Diaporthales is a species-rich order of fungi that includes endophytes, saprobes, and pathogens associated with forest plants and crops. They may also occur as parasites or secondary invaders of plant tissues injured or infected by other organisms or inhabit living animal and human tissues, as well as soil. Meanwhile, some severe pathogens wipe out large-scale cultivations of profitable crops, timber monocultures, and forests. Based on morphological and phylogenetic analyses of combined ITS, LSU, tef1-α, and rpb2 sequence data, generated using maximum likelihood (ML), maximum parsimony (MP), and MrBayes (BI), we introduce two new genera of Diaporthales found in Dipterocarpaceae in Thailand, namely Pulvinaticonidioma and Subellipsoidispora. Pulvinaticonidioma is characterized by solitary, subglobose, pycnidial, unilocular conidiomata with the internal layers convex and pulvinate at the base; hyaline, unbranched, septate conidiophores; hyaline, phialidic, cylindrical to ampulliform, determinate conidiogenous cells and hyaline, cylindrical, straight, unicellular, and aseptate conidia with obtuse ends. Subellipsoidispora has clavate to broadly fusoid, short pedicellate asci with an indistinct J- apical ring; biturbinate to subellipsoidal, hyaline to pale brown, smooth, guttulate ascospores that are 1-septate and slightly constricted at the septa. Detailed morphological and phylogenetic comparisons of these two new genera are provided in this study.

New Spirostane from a Fungus Neohelicomyces hyalosporus and Its Bioactivity.

A new spirostane, namely neohelicomyine B (1), together with six known steroids (2-7) were isolated from the fermentation of fungus Neohelicomyces hyalosporus. The structures of these compounds were elucidated by extensive analyses of spectroscopic methods including 1D and 2D NMR and HR-ESI-MS. The absolute configuration of 1 was confirmed by single-crystal X-ray diffraction. The bioactivities of compounds 1-7 were evaluated using cellular assays. Compound 1 displayed moderate cytotoxicity against HepG2 cells (hepatoma cells) with IC50 value of 8.4±2.1 µM. Compound 7 also exhibited cytotoxic activity against HepG2 cells with the IC50 value of 3.0±0.2 µM.

A Novel Effector FlSp1 Inhibits the Colonization of Endophytic Fusarium lateritium and Increases the Resistance to Ralstonia solanacearum in Tobacco.

Effectors are crucial for the interaction between endophytes and their host plants. However, limited attention has been paid to endophyte effectors, with only a few reports published. This work focuses on an effector of Fusarium lateritium, namely FlSp1 (Fusarium-lateritium-Secreted-Protein), a typical unknown secreted protein. The transcription of FlSp1 was up-regulated after 48 h following fungal inoculation in the host plant, i.e., tobacco. The inactivation of FlSp1 with the inhibition rate decreasing by 18% (p < 0.01) resulted in a remarkable increase in the tolerance of F. lateritium to oxidative stress. The transient expression of FlSp1 stimulated the accumulation of reactive oxygen species (ROS) without causing plant necrosis. In comparison with the wild type of F. lateritium (WT), the FlSp1 mutant of the F. lateritium plant (ΔFlSp1) reduced the ROS accumulation and weakened the plant immune response, which resulted in significantly higher colonization in the host plants. Meanwhile, the resistance of the ΔFlSp1 plant to the pathogenic Ralstonia solanacearum, which causes bacterial wilt, was increased. These results suggest that the novel secreted protein FlSp1 might act as an immune-triggering effector to limit fungal proliferation by stimulating the plant immune system through ROS accumulation and thus balance the interaction between the endophytic fungi and their host plants.

Diversity, morphology, and molecular phylogeny of Diatrypaceae from southern China.

During an investigation of Diatrypaceae from southern China, 10 xylariales-like taxa have been collected. Morphological and multi-gene analyses confirmed that these taxa reside in Diatrypaceae and represent eight novel taxa and two new records belonging to six genera (viz., Allocryptovalsa, Diatrype, Diatrypella, Paraeutypella, Peroneutypa, and Vasilyeva gen. nov.). Vasilyeva gen. nov. was proposed to accommodate Vasilyeva cinnamomi sp. nov. Among the other collections, seven new species were introduced (viz., Diatrype camelliae-japonicae sp. nov., Diatrype rubi sp. nov., Diatrypella guiyangensis sp. nov., Diatrypella fatsiae-japonicae sp. nov., Paraeutypella subguizhouensis sp. nov., Peroneutypa hainanensis sp. nov., and Peroneutypa qianensis sp. nov.), while two were reported as new records from China (Allocryptovalsa rabenhorstii and Diatrype enteroxantha). For Diatrypaceae, the traditional taxonomic approach based on morphology may not be applicable.

New Guaiane-Type Sesquiterpenoids Biscogniauxiaols A-G with Anti-Fungal and Anti-Inflammatory Activities from the Endophytic Fungus Biscogniauxia Petrensis.

Seven undescribed guaiane-type sesquiterpenoids named biscogniauxiaols A-G (1-7) were isolated from the endophytic fungus Biscogniauxia petrensis on Dendrobium orchids. Their structures were determined by extensive spectroscopic analyses, electronic circular dichroism (EC) and specific rotation (SR) calculations. Compound 1 represented a new family of guaiane-type sesquiterpenoids featuring an unprecedented [5/6/6/7] tetracyclic system. A plausible biosynthetic pathway for compounds 1-7 was proposed. The anti-fungal, anti-inflammatory and multidrug resistance reversal activities of the isolates were evaluated. Compounds 1, 2 and 7 exhibited potent inhibitory activities against Candida albicans with MIC values ranging from 1.60 to 6.30 µM, and suppressed nitric oxide (NO) production with IC50 ranging from 4.60 to 20.00 µM. Additionally, all compounds (100 µg/mL) enhanced the cytotoxicity of cisplatin in cisplatin-resistant non-small cell lung cancer cells (A549/DDP). This study opened up a new source for obtaining bioactive guaiane-type sesquiterpenoids and compounds 1, 2, and 7 were promising for further optimization as multifunctional inhibitors for anti-fungal (C. albicans) and anti-inflammatory purposes.

Characterization and Genome Analysis of Cladobotryum mycophilum, the Causal Agent of Cobweb Disease of Morchella sextelata in China.

Cobweb disease is a fungal disease that can cause serious damage to edible mushrooms worldwide. To investigate cobweb disease in Morchella sextelata in Guizhou Province, China, we isolated and purified the pathogen responsible for the disease. Through morphological and molecular identification and pathogenicity testing on infected M. sextelata, we identified Cladobotryum mycophilum as the cause of cobweb disease in this region. This is the first known occurrence of this pathogen causing cobweb disease in M. sextelata anywhere in the world. We then obtained the genome of C. mycophilum BJWN07 using the HiFi sequencing platform, resulting in a high-quality genome assembly with a size of 38.56 Mb, 10 contigs, and a GC content of 47.84%. We annotated 8428 protein-coding genes in the genome, including many secreted proteins, host interaction-related genes, and carbohydrate-active enzymes (CAZymes) related to the pathogenesis of the disease. Our findings shed new light on the pathogenesis of C. mycophilum and provide a theoretical basis for developing potential prevention and control strategies for cobweb disease.

A Saprophytic Fungus Tubeufia rubra Produces Novel Rubracin D and E Reversing Multidrug Resistance in Cancer Cells.

Two new (1, 2 viz Rubracin D and E) and sixteen known Glyceroglycolipids (3-18) in the saprophytic fungus Tubeufia rubra (PF02-2) from decaying wood in freshwater habitat were isolated and identified. Their chemical structures were elucidated via means of the extensive spectroscopic analyses of NMR, HR-ESI-MS and UV spectra, as well as comparison with literature data. The new compounds were assayed for the reversal activity of multidrug resistance (MDR) on MCF-7/ADM, K562/ADM and A549/ADM cell lines, and both compounds 1 and 2 reversed MDR in the three resistant cancer cell lines with concentration dependence. In the assay on K562/ADM, both new compounds had been proved to have remarkable MDR reversal effects, which were higher than those of the positive control viz Verapamil (Vrp). Meanwhile, in the assay on A549/ADM, compound 1 displayed significant MDR reversal effects, which were also higher than those of Vrp at certain concentrations. Furthermore, the Western blot assay proved that both new compounds reversed the MDR in the resistant cancer cell line viz MCF-7/ADM by inhibiting the overexpression of P-glycoprotein. This is the first report that the Glyceroglycolipids isolated firstly from the fungal genus Tubeufia reversed MDR in resistant cancer cells.

Neogrisphenol A, a Potential Ovarian Cancer Inhibitor from a New Record Fungus Neohelicosporium griseum.

From the rice fermentation product of a new record fungus, Neohelicosporium griseum, two new polyketides, neogrisphenol A (1) and neogrisphenol B (2), one new isochroman-1-one, (S)-6-hydroxy-7-methoxy-3,5-dimethylisochroman-1-one (3), and four known compounds (4-7) were isolated. Their structures were determined using 1D- and 2D-NMR, mass spectrometry, and chemical calculations. The C-3~C-2' polymerization mode between the two α-naphthalenone derivative moieties is uncommon in compounds 1 and 2. Meanwhile, compounds 1-2 and 5 exhibited antibacterial activity against Bacillus subtilis, Clostridium perfringens, Staphylococcus aureus, and Staphylococcus aureus, with MIC values ranging between 16 and 31 µg/mL. In addition, compound 5 showed antifungal activity against Sclerotinia sclerotiorum and Phytophthora nicotianae var. nicotianae, with respective IC50 values of 88.14 ± 2.21 µg/mL and 52.36 ± 1.38 µg/mL. Compound 1 showed significant cytotoxicity against A2780, PC-3, and MBA-MD-231 cell lines with respective IC50 values of 3.20, 10.68, and 16.30 µM, and the cytotoxicity against A2780 cells was even higher than that of cisplatin (CDDP). With an IC50 value of 10.13 µM, compound 2 also exhibited cytotoxicity against A2780. The in vitro results showed that compound 1 inhibited A2780 cell proliferation, induced apoptosis, and arrested the cell cycle at the S-phase in a concentration-dependent manner.