Fungal Biology Reviews最新文献

Fungi that spoil foods or infect crops can have major socioeconomic impacts, posing threats to food security. The strategies needed to manage these fungi are evolving, given the growing incidence of fungicide resistance, tightening regulations of chemicals use and market trends imposing new food-preservation challenges. For example, alternative methods for crop protection such as RNA-based fungicides, biocontrol, or stimulation of natural plant defences may lessen concerns like environmental toxicity of chemical fungicides. There is renewed focus on natural product preservatives and fungicides, which can bypass regulations for ‘clean label’ food products. These require investment to find effective, safe activities within complex mixtures such as plant extracts. Alternatively, physical measures may be one key for fungal control, such as polymer materials which passively resist attachment and colonization by fungi. Reducing or replacing traditional chlorine treatments (e.g. of post-harvest produce) is desirable to limit formation of disinfection by-products. In addition, the current growth in lower sugar food products can alter metabolic routing of carbon utilization in spoilage yeasts, with implications for efficacy of food preservatives acting via metabolism. The use of preservative or fungicide combinations, while involving more than one chemical, can reduce total chemicals usage where these act synergistically. Such approaches might also help target different subpopulations within heteroresistant fungal populations. These approaches are discussed in the context of current challenges for food preservation, focussing on pre-harvest fungal control, fresh produce and stored food preservation. Several strategies show growing potential for mitigating or reversing the risks posed by fungi in the food supply chain.

Adaptation to the host environment is crucial for fungal pathogenesis. Calcium (Ca²⁺) signals are essential for fungal cells to respond rapidly to stress stimuli. In eukaryotic cells, Ca²⁺ is the main intracellular secondary messenger and regulates a myriad of processes, including the cellular fitness of the fungal pathogen Cryptococcus neoformans. In this minireview, we highlight the main cryptococcal processes regulated by Ca²⁺. Moreover, we underline all the characterized proteins responsible for intracellular calcium homeostasis in this yeast, such as Ca²⁺ transporters and binding proteins. These elements, in general, are essential for C. neoformans’ growth and adaptation to the host environment, as well as to virulence mechanisms. We also revisit the specific traits of the calcineurin signaling pathway in C. neoformans, which is the major pathway regulated by calcium and is crucial for yeast pathogenesis, adaptation, and growth at 37 °C. Notably, several Ca²⁺-related functions are highly conserved throughout fungal cells. Moreover, C. neoformans exhibits exclusive, significant features that are required for disease progression, thus attracting attention as feasible targets for antifungal drug development. Collectively, all the available data related to Ca²⁺ processes clarify the complex role that Ca²⁺ plays within cryptococcal cells, participating in host adaptation, transmigration, antifungal resistance, cell growth, and more.

Chytridiomycota is the most species-rich phylum of basal lineage fungi involved in vital processes in both terrestrial and aquatic ecosystems. Still, the diversity and richness of this group remains cryptic. In Northern Europe, few species have been recorded despite the numerous intact lake systems covering this region. Recent classifications of early diverging fungal lineages differ considerably on the diversity of chytrid species and their taxonomic placement. Here, we present the current knowledge of the Chytridiomycota diversity within Northern Europe by using the Global Biodiversity Information Facility (GBIF) data and compare how this diversity distributes across two recently proposed classification systems. Furthermore, we illustrate how various sampling types are influencing the recorded classification levels. Lastly, we discuss how metabarcoding has contributed to the overall understanding of the Chytridiomycota diversity in revealing the “dark matter fungi”, and we point out future research needs in the field of aquatic mycology in the Nordic region.

Gap analysis of the available genomic data (i.e. identifying taxonomic groups with no representative genome assemblies) is a fundamental first step to design effective sampling strategies for whole genome sequencing (WGS) initiatives. We identified the significant holes that remain in genomic resources of the Ascomycota – the largest fungal phylum including many species of medicinal, ecological and/or economic significance – in order to prioritise WGS efforts towards reconstructing the Ascomycota tree of life. In doing so, we additionally looked at the existing genome size data for ascomycetes, given the importance of knowing the size of the genome to ensure sufficient sequencing coverage and assess the completeness and quality of genome assemblies. We found that 50 % of the ascomycete orders have no representative genome assembly and over 75 % have no reliably measured genome size data. We propose that integrating routine cytometric genome size measurements into WGS and genome assembly pipelines will provide both a valuable assembly quality metric and contribute data for addressing fundamental evolutionary questions.

Stipe elongation growth is one of the remarkable characteristics of the growth and development of basidiomycete fruiting bodies. Stipe elongation is resulting from the lateral extension of stipe cells. The stipe cell is enclosed within a thin cell wall which must be loosened to expand the wall surface area for accommodation of the enlarged protoplast as the stipe cell elongates. In fungal cell walls, chitin molecules associate with each other by interchain hydrogen bonds to form chitin microfibrils which are cross-linked covalently to matrix polysaccharides. Early, some scientists proposed that stipe elongation was the result of enzymatic degradation of wall polysaccharides, whereas other researchers suggested that stipe elongation resulted from nonhydrolytic disruption of the hydrogen bonds by turgor pressure between wall polysaccharides. Recently, an extensometer was used to determine stipe wall extension for elucidation of the molecular mechanism of stipe elongation. In Coprinopsis cinerea, the native stipe cell wall is induced to extend by acidic buffers and the acid-induced native wall extension activity is located in the growing apical stipe region. A series of current experiments indicate that chitinases play a key role in the stipe wall extension, and β-glucanases mainly function in the wall remodeling for regulation of stipe wall expansibility to cooperate with chitinase to induce stipe wall extension. In addition, fungal expansin-like proteins can bind to chitin to enhance chitin hydrolysis, and their expression pattern is consistent with the stipe elongation growth, which is suggested to play an auxiliary role in the stipe wall extension.

Fungal pathogens face similar stress conditions to those affecting plants and saprotrophic fungi. Therefore, mechanisms underlying fungal response to the stress factors may be well-conserved across various taxa. Saccharomyces cerevisiae was the most researched for signal transduction pathways but many of the pathways' components were later reported for filamentous fungi as well. The most widely studied pathways are those involving the G proteins, adenylate cyclase (cAMP) and mitogen-activated protein kinases (MAPKs). Apart from these, the target-of-rapamycin (TOR), calcium/calcineurin and cell wall integrity (CWI) pathways are of significant interest when stress response is considered. All these pathways were included in this review. It seems that the TOR-received signals are transferred to the CWI pathway, secondary metabolism and virulence. Specific and non-specific cellular responses of Fusarium species, triggered by signals received from the environment, were discussed, with particular focus on stress response and pathogenicity towards the plant host.

Genome-editing CRISPR-Cas systems, using Cas9 and Cas12a endonucleases, have improved our ability to precisely edit genomes and control gene expression. We summarize here the knowledge gained from using CRISPR-Cas9 and CRISPR-Cas12a in fungal research. Also discussed are strategies developed for limiting the occurrences of off-target mutations caused by CRISPR-Cas genome editing.

Alternative splicing is a common but complex posttranscriptional regulatory process in eukaryotes, through which multiple different transcripts are produced from a single pre-mRNA. An increasing number of studies have revealed that alternative splicing is widespread in fungi. Intron retention (IR) is considered the most prevalent splicing type due to the relatively short introns and long exons involved in this process. Alternative splicing is coordinated by a variety of factors, including genomic structure characteristics, TPP riboswitches, splicing factors and DNA methylation, and is involved in the regulation of growth and development, and the improvement of survivability and pathogenicity. Taken together, the results show that alternative splicing events are fungal evolutionary adaptations to changing external conditions.

Dictyostelid cellular slime molds are a ubiquitous component of most soils, where they feed upon bacteria and other microbes and thus play an essential role in the soil ecosystem. Herein we review the available literature on dictyostelid cellular slime molds in China, especially their diversity and ecology. The patterns of distribution for these organisms in relation to the different habitats with which they are associated are analyzed and discussed. In addition, the assemblages of dictyostelids reported from China and the United States were compared. The CC value obtained (0.48) indicates that China and the United States are perhaps less similar than might be expected. Our data point out the need for further studies to characterize more completely the assemblages of dictyostelids associated with particular vegetation types or particular regions throughout the world.

The evolution of multicellularity has been one of the major transitions in the history of life. In contrast to animals and plants, how multicellularity evolved in fungi and how it compares to the general principles distilled from the study of more widely studied model systems, has received little attention. This review broadly discusses multicellular functioning and evolution in fungi. We focus on how fungi solved some of the common challenges associated with the evolution of multi-celled organisms and what unique challenges follow from the peculiar, filamentous growth form of fungi. We identify and discuss seven key challenges for fungal multicellular growth: apical growth, compartmentalization, long-distance mass transport, controlling mutational load, cell-to-cell communication, differentiation and adhesion. Some of these are characteristic of all multicellular transitions, whereas others are unique to fungi. We hope this review will facilitate the interpretation of fungal multicellularity in comparison with that of other multicellular lineages and will prompt further research into how fungi solved fundamental challenges in one of the major transitions in their evolutionary history.