Mycology最新文献

Glycosides tremendously extend the wide spectrum of biological activities of flavonoids and phenolics, which are catalysed by the glycosyltransferases (GTs) in diverse plants, bacteria, and fungi. However, the glycosyltransferases identified from fungi are still limited. Herein, one novel O-glycosyltransferase of MrOGT2 from the entomopathogenic fungus Metarhizium robertsii was presented. MrOGT2 exhibited typical substrate promiscuity characteristics towards four uridine diphosphate (UDP) sugar donors and 17 sugar receptors including flavonols, flavanones, flavones, isoflavones, and phenolics five types of compounds. Molecular docking and site-directed mutagenesis revealed the key substrate binding sites in the binding pocket and possible conservative catalytic mechanism of the O-glycosyltransferase MrOGT2. Our research provides an advance in the knowledge of glycosyltransferase in fungi and contributes the application potential for the efficient biocatalyst of O-glycosylation to both agricultural and pharmaceutical industries.

Candida spp. are opportunistic pathogens associated with mucosal and cutaneous infections. Its increased resistance to antifungals has instigated the development of adjunct treatments, such as antimicrobial photodynamic therapy (aPDT). This study evaluated the antifungal effects of aPDT mediated by two tetra-cationic porphyrins with peripheral platinum(II) complexes (3-Pt and 4-Pt). A thorough investigation was performed using in vitro and in vivo assays to determine their antifungal activity on Candida albicans and toxicity in human cells. Next, specific models were employed to search for understanding of the action of aPDT on Candida-associated infections. As a result, a MIC value of 16 μmol/L was found for both porphyrins, with low toxicity to keratinocytes even in higher concentrations. Planktonic cultures of C. albicans treated by aPDT with 3-Pt achieved complete inhibition in 40 s, while 4-Pt reduced 1.3 Log10 (CFU) within 80 s. These effects were also extended to C. albicans biofilms, in which 3-Pt and 4-Pt reduced 4 and 0.8 Log₁₀ (CFU), respectively. The mechanisms of action of 3-Pt were related to hyphae inhibition, increased ROS production, and cell wall damage. Finally, 3-Pt showed efficacy against denture stomatitis biofilms in a microcosm model and burn wounds in Galleria mellonella, indicating its potential for treating Candida-associated infections.

PCR-based techniques play a crucial role in genotyping and genetic screening in fungal biology. Rapid access to nucleic acids for these reactions can significantly improve the efficiency of fungal analysis, especially when multiple samples need to be tested. In this study, we introduced a simple and rapid method for detecting small amounts of fungal DNA or RNA, named the One-Step method, and confirmed its applicability across various experimental scenarios for fungal detection. The method involves scraping a small quantity of spores or mycelium into sterile water, followed by heat shock, vortexing, and centrifugation to obtain a supernatant that serves as a template for the PCR reaction. Notably, nucleic acids were successfully extracted using the One-Step method from four different genera of fungi-Neurospora crassa, Aspergillus fumigatus, Fusarium oxysporum, and Schizosaccharomyces pombe, as well as from two mycovirus-containing strains, yielding reliable results in PCR identification. However, the nucleic acids of Cryptococcus neoformans were not successfully extracted using the One-Step method, possibly due to the challenge of cleaving its polysaccharide capsule. Taken together, the One-Step method significantly reduces nucleic acids extraction time while enhancing strain screening efficiency in four different fungi, indicating a broad applicability in fungal biology.

As pathogenic fungi increasingly threaten public health, particularly in immunocompromised populations, understanding the mechanisms behind fungal drug resistance has become critical. This review focuses on the pivotal role of mitochondria in this process. Evidence indicates that mitochondria are essential not only for cellular energy metabolism and responses to oxidative stress but also for significantly influencing the expression and activity of drug efflux pumps, which facilitate the expulsion of antifungal agents. Moreover, the intricate roles of mitochondria in iron homoeostasis and calcium signalling are closely linked to the development of drug resistance in fungi. By elucidating these mechanisms, we can identify potential therapeutic targets and pave the way for more effective strategies to combat resistant fungal infections.

Graviresponses, the growth responses of organisms to gravitational alterations, are pivotal yet understudied phenomena in fungi compared to plants and animals. Fungi perceive gravity through proposed statoliths, including nuclei connected to actin filaments, octahedral protein crystals, and floating lipid globules. These mechanisms generate sufficient potential energy to overcome thermal noise and establish detectable gradients within cells. Signal transduction involves ion fluxes, reactive oxygen species, and cytoskeletal components, transducing physical signals into polarised cell wall loosening. In mushroom-forming fungi, gravitropic responses manifest primarily through differential hyphal elongation in the stipe, while gravimorphogenetic responses cause broader developmental and morphological changes. Though basic fruiting body formation can occur in microgravity, proper spore dispersal requires gravity sensing which triggers molecular mechanisms involving precise regulation of cell wall modification, vesicle trafficking, and complex signalling cascades, particularly in specialised tissues of the fruiting body. Curvature compensation mechanisms ensure optimal vertical alignment of spore-bearing tissues through feedback systems. Studies of model organisms like Coprinopsis cinerea, Flammulina velutipes, and Phycomyces blakesleeanus have revealed species-specific gravisensing mechanisms that reflect diverse ecological strategies for spore dispersal. Despite advances in understanding these mechanisms, key questions remain about morphogenetic regulation and signal transduction. This review examines classical and modern findings while highlighting opportunities for investigation using contemporary molecular approaches.

Sporotrichosis, a neglected tropical disease caused by Sporothrix species, is a growing concern, particularly due to the emergence of highly virulent, cat-transmitted S. brasiliensis. Rapid diagnosis and surveillance are crucial for controlling sporotrichosis. This study investigated the 3-carboxymuconate cyclase (CMC) gene, which encodes the major Sporothrix antigen (Gp60-70), as a molecular marker to understand the genetic diversity and evolution of these fungi. Analysis of 104 isolates (S. brasiliensis, S. schenckii, S. globosa, and S. luriei) revealed 79 unique haplotypes, demonstrating superior discriminatory power over traditional molecular markers. High-CMC polymorphisms, especially in S. brasiliensis and S. schenckii, suggest recent population expansion or positive selection, potentially driven by environmental pressures such as polyaromatic hydrocarbon pollutants. The conserved chromosomal location of CMC in pathogenic Sporothrix and its absence in less virulent species suggest a role in virulence. Identifying conserved residues within predicted B-cell epitopes provides targets for diagnostics and therapeutics. Additionally, we identified N-linked glycosylation sequons (e.g. NGS at 62, NNT at 225, and NGT at 373/374) conserved in pathogenic Sporothrix but absent in environmental Sordariomycetes, possibly contributing to pathogenicity and niche adaptation. This study establishes CMC as a valuable marker for understanding Sporothrix evolution and virulence, aiding in sporotrichosis management.

The transcription factor Mbp1 was reported to regulate cell growth and proliferation in some fungi; however, its role in Pleurotus ostreatus remains largely unexplored. Here, we cloned the PoMbp1 gene, which encodes a protein contains an APSES domain and is localised in the nucleus. The expression pattern analysis showed that PoMbp1 was expressed more in the caps of the fruiting body than in other stages. The growth rates of the PoMbp1 overexpression strains OE-PoMbp1 were similar to those of wild-type, while that in the interference strains RNAi-PoMbp1 were markedly reduced, indicating that PoMbp1 positively regulates P. ostreatus development. Transcriptome sequencing showed that the DEGs between PoMbp1 transformants and wild-type mainly enriched in carbohydrate metabolism, cell growth and death, etc. The DEGs in polysaccharide catabolic were highly expressed in the OE-PoMbp1 strains. Treat PoMbp1 transformants with different monosaccharides and polysaccharides, the OE-PoMbp1 strains grew faster than wild-type on medium containing polysaccharide, whereas no differences were observed with monosaccharides. The RNAi-PoMbp1 strains showed an opposite trend. These results indicated that PoMbp1 plays a positive role in fruit body development by enhancing the expression of genes related to polysaccharide utilisation. This study provides a theoretical reference for research on the mechanism of fruiting body development of P. ostreatus.

Members of the Rhytismataceae (Rhytismatales) are found all over the world, which include saprobes, endophytes, and plant pathogens. They can infect a wide variety of host plants and cause plant diseases. As one of the most preferred hosts of rhytismatalean fungi, a total of 90 species of Rhytismatales in 21 genera are known by Rhododendron spp. worldwide, including 53 species on twigs and 37 species on leaves. In this research, a sum of 46 specimens were collected from the twigs of Rhododendron species in China. Subsequently, based on multi-gene phylogenetic analyses using molecular sequence data from the internal transcribed spacer (ITS) region, the large subunit of the ribosomal RNA gene (nrLSU), the mitochondrial small subunit (mtSSU), and morphological characteristics, three new genera were proposed (Neolophodermium, Truncomyces, and Virgamyces), and 21 species in 11 genera of Rhytismataceae were delimited, which include 18 new species and three new combinations. This study complements the diversity of Rhytismataceae on twigs of Rhododendron. An integrated taxonomic approach includes the evidence for morphological characteristics, the ecological data, and the phylogenetic analyses based on multiple loci and was demonstrated, which can be defined a natural classification of Rhytismataceae on the genus level.

Daqu, the starter used in Baijiu making process, is produced by spontaneous solid-state fermentation and contains numerous microbes and enzymes, significantly influencing the yield and flavour profile of Baijiu. In this study, we employed a full-length ITS metabarcoding approach using the PacBio sequencing technology to investigate the fungal diversity in 296 samples of low- (LTD), medium- (MTD) and high-temperature Daqu (HTD) collected from 10 provinces in China. In total, we identified 86 species or species groups in the fungal communities of Daqu. The fungal communities of the three types of Daqu were significantly different and the differences were also associated with their geographical origins. Ascoideales (relative abundance 21.04%), Pichiales (15.38%), Mucorales (39.54%) and Eurotiales (19.96%) totally accounted for 95.92% of the fungal community of the Daqu samples. The former two were significantly enriched in the LTD samples and the latter two in the MTD and HTD samples, respectively. We also identified the distinct fungal species that showed differential enrichment within each Daqu type as well as among samples of the same type originating from different regions. These findings offer a deeper insight into the fungal communities associated with various Daqu types and their geographical origins at the species level.

This study investigates the prevalence, drug resistance, and genetic diversity of Candida glabrata, a significant non-albicans Candida species, among pregnant women in Hainan, China. We collected 3,806 reproductive tract secretion samples from women with vaginal discomfort and isolated 594 Candida strains, including C. albicans (45.1%), C. glabrata (36.2%), C. dubliniensis (12.2%), C. parapsilosis (2.7%), C. tropicalis (2.7%), and C. krusei (1.2%). Antifungal susceptibility testing showed that 64.5% of the isolates were intermediate or resistant to at least one of four antifungal agents: fluconazole, itraconazole, voriconazole, and amphotericin B. Among 215 C. glabrata isolates, 81.4% were intermediate or resistant to at least one antifungal, with 10% showing resistance to multiple agents. Multilocus sequence typing (MLST) of 52 C. glabrata strains from the reproductive tract, 53 from oral cavities, and 17 from environmental sources revealed 14 sequence types (STs), with six STs shared among these niches, indicating a highly clonal population structure. Comparisons with the global MLST database showed both shared and distinct characteristics among C. glabrata populations in Hainan and other regions, highlighting significant differentiation. We discuss the implications of these findings to the epidemiology and evolution of this pathogen.