Fungal Biology Reviews最新文献

Fungi exhibit a wide range of sporophore morphologies. Amongst the Agaricomycetes, sporophores include mushroom, coralloid, bracket and sequestrate forms. A striking observation is the repeated independent evolution of sequestrate forms, which have arisen more than 100 times from lineages where exposed spore-bearing tissues are the ancestral condition. Here we review the evolution of a particular sequestrate morphology in Agaricales, the labyrinthine sequestrate syndrome. We draw on knowledge of genetic mechanisms involved in sporophore development of agarics (mushrooms) and suggest potential genetic changes in relation to the alterations to pileus, lamellae and stipe during development. We discuss mechanisms that could give rise to the sequestrate syndrome.

The genus Trichosporon includes yeasts that are naturally present within the human gastrointestinal tract, on the skin, and as part of the vaginal microbiota. This genus is an opportunistic pathogen, commonly found in fungal infections affecting immunocompromised individuals. The species Trichosporon asahii (T. asahii) causes the majority of trichosporonoses and is therefore widely studied, particularly in relation to its pathogenicity and its emerging resistance to antifungal drugs used to treat the disease. However, T. asahii also has important biotechnological applications, particularly its depolluting abilities and its bioproduction of flavor compounds (e.g., terpenes, C13-Norisoprenoids, C6 compounds, methyl hexanoate, and ethyl isovalerate) and antioxidant molecules. T. asahii also produces substances that inhibit certain contaminants found in dairy products, such as Kocuria rhizophila, Clostridium tyrobutyricum, and Salmonella enterica. Paradoxically, this yeast species also has some potential probiotic applications. This review aims to discuss and provide updates on the taxonomy, pathogenicity, and biotechnological relevance of T. asahii.

Post-translational modifications (PTMs) alter the molecular structure and function of proteins while tightly regulating protein turnover and activity. Eukaryotes exhibit a wide range of PTMs, including phosphorylation, ubiquitination, acetylation, glycosylation, methylation, lipidation, and palmitoylation. Ubiquitination, facilitates the degradation of specific substrates through PTMs. This process heavily relies on the SCF complex (SKP1-Cullin-F-box protein) a type of E3 ubiquitin ligase, which plays a crucial role in the recruitment of target substrates for ubiquitination. Apart from substrate degradation, F-box proteins in pathogenic fungi are involved in diverse cellular processes essential for fungal growth and virulence. In this review article, we summarize the functions of various F-box proteins in pathogenic fungi, discussing their roles in cellular functions such as pathogenicity during host infection, transcription and cell cycle progression, endocytic recycling, sexual reproduction, mitochondrial connectivity, and maintenance of circadian rhythm. Furthermore, recent studies have revealed a novel function of fungal F-box proteins in biofuel production via CAZymes, highlighting their industrial significance. This comprehensive review aims to enhance our understanding of the emerging role of F-box proteins in host-pathogen interactions, and it holds broader significance for the scientific community, stimulating new discussions and future investigations in this field.

Over three decades ago, the plant-derived anticancer agent taxol (brand name: paclitaxel) was reported from a fungal endophyte colonizing the producing plant. The hope that this finding could ever result in a sustainable production process has thus far been disappointed. Modern evidence on the evolution of secondary metabolites in plants vs. fungi suggests that this hypothesis (that fungi could produce such complex plant metabolites) is invalid. Still, numerous inconclusive original studies -and in particular, review papers by non-experts in the field-are continuously being published that claim the opposite. The current commentary tries to deal with the topic, taking the findings of –OMICS studies and current state-of-the art mycology into account. This can hopefully help to stop the scientific papermills from further spreading the fake news that fungi were capable of sustainable production of taxol.

The demand to develop protein production systems that are both economically and scientifically viable is reflected in the global scenario, where filamentous fungi, due to their interesting characteristics such as the high capacity to secrete proteins into the culture medium, growth in relatively simple substrates and robust post-translational machinery, among others, are presented as promising alternatives for the creation and establishment of these systems. Currently, these organisms produce a wide range of proteins, such as glycosidases, lipases, and proteases, for example. Scientific and technological development has increasingly allowed the evolution of molecular biology techniques that facilitate the genetic modification of organisms, thus, stimulating the establishment of new protein production systems. Amongst these techniques, it is possible to highlight the CRISPR/Cas system, a relatively simple, low-cost, and high-efficient tool for genetic modifications. Filamentous fungi, organisms widely used for protein production, have been used in a relatively low number of studies related to the production of (hemi-)cellulases using the CRISPR/Cas system as a genomic editing tool. (Hemi-)cellulases, enzymes that catalyze the breakdown of saccharides, are a class of enzymes that are highly researched and applied in several biotechnological areas in order to obtain a wide range of value-added bioproducts, such as bioethanol, for example. In this context, this review aims to illustrate the scenario of the application of the CRISPR/Cas technique for the production of (hemi-)cellulases, highlighting the main studies to date and the perspectives of a market that tends to grow exponentially in the coming years.

Many unnamed fungi have been revealed from DNA sequences but cannot be formally named due to a lack of physical materials required for the description of a taxon by the International Code of Nomenclature for algae, fungi, and plants. While the mycological community generally discusses the necessity to amend the code to permit DNA sequence data as the nomenclatural type of these fungal ‘dark taxa’ (FDT), the standard of DNA sequences is mainly in debate. Here, I suggest to set an approximate fifteen years transition period. During that time, it is recommended to sequence the whole genomes of all known species and newly published species with available physical materials; meanwhile, the FDT can be provisionally named with priority using whole genome data as the type. After the transition period, these provisionally named FDT will become valid, provided no known species from physical materials with a priority can be proved to be conspecific. Moreover, in this new era of fungal taxonomy when the whole genome data will be commonly used as the crucial evidence to delimit fungal species, new taxa should be named along with the deposition of whole genome sequences in public databases, and the whole genome data may be the type of the FDT.

In many eukaryotes, small RNAs (sRNAs) can mediate gene expression regulation through a mechanism known as RNA silencing. In fungi, RNA silencing plays a crucial role in numerous biological processes, including parasitic and mutualistic fungus-plant interactions. This review summarizes recent findings on the role of RNA silencing in parasitic fungus-fungus and fungus-insect interactions in relation to their use for the biological control (biocontrol) of fungal plant diseases and insect damage. Genes belonging to the RNA silencing machinery are identified in the genomes of almost all known fungal and oomycete biocontrol organisms. However, recent functional genetic studies in Ascomycota species of the Hypocreales order, such as Trichoderma atroviride and Clonostachys rosea, show how RNA silencing can have family-specific effects, as conidiation is affected differently in the two organisms when the same elements of the RNA silencing machinery are deleted. The size of sRNAs regulated by RNA silencing can also vary between organisms. Cross-species RNA silencing represents a new field in the study of antagonistic interactions. For example, a microRNA (miRNA) of another hypocrealean fungus, Beauveria bassiana, was proven to target genes involved in the immune response of mosquitoes, and there are indications that miRNAs from the mycoparasitic C. rosea may target factors of virulence in its plant-pathogenic host fungi. Accumulating evidence from many species shows that the number of endogenous genes affected by the disruption of the RNA silencing mechanism is always much higher than the number of predicted direct target genes. As several putative targets of fungal sRNAs are transcription factors, it is possible that specific sRNAs have a role as master regulators of gene expression, affecting the transcription of a high number of genes through cascading regulating effects. The challenges faced when studying cross-species RNA silencing, including sRNA trafficking during mycoparasitism, are also discussed. This includes the difficulties in separating the extracellular vesicles of mycoparasitic fungi from those of their hosts, the high amount of sequencing reads lost in bioinformatics filtering steps, imprecise target prediction and the lack of a streamlined accepted way of reporting results.

The primary cause of blindness and visual impairment worldwide is fungal keratitis, an infection of the cornea. The predominant etiology of these fungal infections is influenced by several variables, including socioeconomic level, geographic origin, and climatic circumstances. Aspergillus spp. and Fusarium spp. are typically responsible for the infection in tropical and subtropical regions, whereas Candida spp. predominate in temperate zones. Anatomical barriers are a crucial first line of protection because most infectious agents are exogenous. By releasing antimicrobial chemicals like lysozyme, lactoferrin, lipocalin, and defensins that are found in tears or secreted over the cornea, corneal cells operate as the body's second line of defense. Additionally, immunity against fungal infections is provided by the cellular immune response that is triggered by the presence of fungi or their products at the corneal surface. T lymphocytes and neutrophils are drawn to the infection site as a result of activated signaling pathways in corneal cells. A comprehensive defense against fungal keratitis is provided by the antifungal mechanism acting as the host defense at the corneal surface. Furthermore, developing treatment plans for fungal keratitis may be influenced by knowledge of the molecular underpinnings of host protection against fungal infections. In the current work, we outlined the most recent developments in our understanding of the host-pathogen interaction and host-immune response in fungal keratitis of mouse and human corneal tissue.

Skin, hair, and nail fungal infections affect almost a billion people globally and their incidence is rising. Candida spp. and Malassezia spp., two yeasts that are part of the skin microbiota, normally do not cause disease. But, when dysbiosis occurs and the skin microbiome is disturbed, they can become pathogenic. There are conventional antifungals that treat candidiasis and Malassezia infections, such as azoles and allylamines, among others. However, the limitations of these treatments (resistance, side effects) lead to the search for new, alternative, and natural drugs, such as plant extracts (PEs) and essential oils (EOs). But these substances present some limitations (poor bioavailability and poor target capacity), which limits their efficiency. Their incorporation in formulations such as films and hydrogels (HGs) can help overcome these issues and may be a potential alternative to the current treatments. The main objective of this work is to provide a state-of-the-art review on Candida spp., Malassezia spp., mucocutaneous candidiasis and Malassezia infections, the conventional existing treatments and the incorporation of PEs and EOs in films and hydrogels as possible new alternative treatments for these diseases.