Fungal Biology Reviews最新文献

A major challenge for cells lies in their ability to detect, respond and adapt to changing environments that may threaten their survival. Among the numerous evolutionary strategies, cell-to-cell heterogeneity allows the emergence of different phenotypes within a population. This variability in cellular behaviors can be essential for a small fraction of cells to adapt and survive in various environments. Analyses at the single-cell level have allowed to highlight the great variability that is present between cells within an isogenic population. Numerous molecular mechanisms have been uncovered, allowing to understand the emergence and the role of cellular heterogeneity. These attempts at identifying the source of cellular noise have also provided clues for strategies needed to control heterogeneity. In this review, S. cerevisiae is used as an example to illustrate the different factors leading to cell heterogeneity, ranging from intracellular processes to environmental constraints. In addition, some recent strategies developed to modulate cell-to-cell variability are discussed.

Trichoderma spp. are widely used as plant disease biocontrol agents in agriculture. Mycoparasitism, which is an ancestral trait of Trichoderma, is one of the most important mechanisms of reducing the pathogen inocula. Mycoparasitism is a complex physiological process that should be viewed in the broad perspective of microbial competition, and involves the production of enzymes and secondary metabolites. Trichoderma spp. have traditionally been viewed as necrotrophic mycoparasites; however, there are evidences that, at least in some instances, they behave as hemibiotrophs, causing minor damage to the host cell wall and having an intracellular existence in the host cell for a significant period. In this review, we cover different aspects of Trichoderma as mycoparasites, ranging from evolution to genomics and interactions with “non-target” fungi.

Madurella mycetomatis is the main cause of mycetoma, a chronic, granulomatous skin infection of the subcutaneous tissue. One of the main virulence factors is the formation of grains, which are difficult to treat with the currently available antifungal drugs. Studies have indicated that zinc homeostasis could be an important factor for grain formation. Therefore, in this review the mechanisms behind zinc homeostasis in other fungal species were summarized and an in silico analysis was performed to identify the components of zinc homeostasis in M. mycetomatis. Orthologues for many of the zinc homeostasis components found in other fungal species could also be identified in M. mycetomatis, including those components that have been identified to play a role in biofilm formation, a process which has some parallels with grain formation. Zinc homeostasis may well play an important role in the process of grain formation and, therefore, more knowledge on this subject in M. mycetomatis is required as it may lead to novel therapies to combat this debilitating disease.

Mushroom-forming fungi establish mutual beneficial interactions with plants and degrade organic waste. These fungi also play an important role in human societies to produce mycelium materials, as a source of medicinal compounds, and as food. Bacteria interact with mushroom-forming fungi not only as competitors for nutrients and as pathogens but also to establish beneficial interactions. This review discusses the positive interactions of bacteria during the different stages of the life cycle of the white button mushroom Agaricus bisporus and other highly consumed mushroom-forming fungi. Bacteria are key in forming a selective substrate, in providing nutrients, in stimulating growth and mushroom formation, and in protection against pathogens. Implications for the mushroom industry are being discussed.

Microbial growth under extreme conditions is often slow. This is partly because large amounts of energy are diverted into cellular mechanisms that allow survival under hostile conditions. Because this challenge is universal and diversity in extreme environments is low compared to non-extreme environments, slow-growing microorganisms are not overgrown by other species. In some cases, especially when nutrients are scarce, slow growth was even shown to increase stress tolerance. And in at least some species of extremotolerant and extremophilic fungi, growth rate appears to be coupled with their very unusual morphologies, which in turn may be an adaptation to extreme conditions. However, there is more than one strategy of survival in extreme environments. Fungi that thrive in extremes can be divided into (i) ubiquitous and polyextremotolerant generalists and (ii) rarely isolated specialists with narrow ecological amplitudes. While generalists can compete with mesophilic species, specialists cannot. When adapting to extreme conditions, the risk of an evolutionary trade-off in the form of reduced fitness under mesophilic conditions may limit the maximum stress tolerance achievable by polyextremotolerant generalists. At the same time, specialists are rarely found in mesophilic environments, which allows them to evolve to ever greater extremotolerance, since a reduction of mesophilic fitness is likely to have little impact on their evolutionary success.

Ganoderma lucidum (G. lucidum) main attractive pharmacological characteristics are antitumor and immunomodulatory activities which are chiefly associated with its two principal bioactive compounds, those are polysaccharides and triterpenoids. Ganoderic acids (GAs) are one of the most discovered triterpenoids of G. lucidum among various triterpenoids. The prominent medicinal mushroom G. lucidum possesses GAs as essential bioactive constituents that are highly oxygenated lanostane-type triterpenoids. GAs exhibit diverse potential action against numerous diseases such as anticancer, antioxidant, anti-inflammatory, anti-HIV, cardioprotective, antiallergic, antihepatotoxic, neuroprotective and antinociceptive properties. GAs act through different mechanisms that include cytotoxic, apoptosis, inducing cell cycle arrest, inhibition of topoisomerases, antiproliferation, anti-invasion, inhibition of NF-kB AP1/uPA, farnesyl protein transferase and JAK-STAT3 pathway. The miraculous effects of GAs fascinate the researchers for their production. Various environmental factors such as biochemical signals, nutritional and physical that influence the biosynthesis of GA. However, the scarcities of pure compounds or accurately characterized extracts are the main problem of clinical studies. Substantial steps are required for characterized extracts of active compounds. This review contributes a thorough insight into the mode of actions of GAs and their possible reinforcements to overcome various diseases.

Natural collagen-based cultural relics such as parchment and leather are susceptible to the storage environment, including temperature, relative humidity, pollutants, and microorganisms, resulting in the deterioration of the main components of collagen, keratin, tannins, lipids, oils and tanning regents. Significant changes might occur in the appearance, composition and internal structure, accompanied by the impaired physical properties such as thermal stability, flexibility, and tensile strength. Biodeterioration is one of the main factors affecting the long-term storage of parchment and leather artifacts, particularly in environments with high relative humidity, due to the proliferation and growth of bacteria or fungi. This review focuses on the common microbial communities on the parchment and leather artifacts. The biodeterioration mechanism is discussed, which will shed light onto the future research of collagen-based cultural relics.

Malassezia belongs to the fungal division Basidiomycota and plays an important role in the mycobiome of the mammalian system. The fungus propagates by budding and mostly remains commensal with the host comprising of warm-blooded animals. During infection, it converts from yeast to its pathogenic hyphal form and this leads to many diseases in humans. Currently, there are 18 known species of Malassezia out of which 11 species are related to humans and the prevalence of the species varies with geographical location. In addition to several diseases it causes, recent research shows the direct role of the fungus in promoting oncogenesis. The fungus thrives with a fine balance between commensalism and its pathogenic state. Its high lipid content in the cell wall provides a robust defense system against the host immunogenic factors. In this review, we discuss the role of the fungus and its host cell receptors in promoting inflammation and disease. We highlight the potential procancerous role of the metabolites produced by Malassezia in tumor development and highlight how the antimicrobial peptides like Defensin and Nanovesicles like MalaEx modulate the host defense system. Finally, we discuss the importance of fungal dysbiosis caused by Malassezia and its role in human diseases. Though working with the fungus is difficult for several reasons, utilizing modern genomic approaches to understanding the biology of this fungus is of tremendous clinical importance. This review highlights different ways by which the fungus affects human health and often leads to several life-threatening diseases including cancer.

Like most eukaryotic organisms, fungi use endocytosis for nutrition, signal transduction, turnover of plasma membrane molecules, etc. It is generally accepted that in filamentous fungi, as in yeast, invaginations of the plasma membrane of a small size (up to about 100 nm) are formed in the early stages of endocytosis. These invaginations are surrounded by a rigid actin scaffold – an actin patch, and give rise to small primary endocytic vesicles after scission from the plasma membrane. However, in classical mycological studies, complex large-volume invaginations of the plasma membrane – lomasomes – were described in filamentous fungi. In our time, in a number of filamentous basidiomycetes when tracking endocytosis using styryl fluorescent labels, large invaginations of the plasma membrane have been found, presumably forming endocytic macrovesicles after scission. In this paper, for comparison, large-sized types of endocytosis in animal cells are briefly described. Information about tubular endocytic invaginations in fungi is presented. Three types of large invaginations of the plasma membrane, detected at the TEM level in basidiomycetes, are characterized. The main question this paper addresses is whether or not filamentous fungi do have an analogue of animal macropinocytosis – macrovesicular endocytosis. There are some indications that the answer to this question is yes, but further research is needed. The presence of macrovesicular endocytosis may change the well-established beliefs about the cellular organization of filamentous fungi and the physiology of their nutrition.

Fungi cause diseases in a variety of marine animal hosts. After a thorough review of published literature, we identified 225 fungal species causing infections of 193 animal species, for a total of 357 combinations of pathogenic fungi and marine animal hosts. Among the 193 animal host species, Chordata (100 species, 51.8 %) and Arthropoda (68 species, 35.2 %) were discovered to be the most frequently reported hosts of fungal pathogens. Microsporidia (111 species, 49.3 %) constitutes over half of the described pathogenic fungal species of marine animals, followed by Ascomycota (85 species, 37.8 %), Mucoromycota (22 species, 9.8 %), Basidiomycota (6 species, 2.7 %) and Chytridiomycota (1 species, 0.4 %). Microsporidia primarily parasitize marine arthropods and Teleostei fish, while Basidiomycota are primarily known to cause respiratory diseases of marine mammals. Ascomycota has a diverse host range, from mammals, fish, crustaceans, soft corals and sea turtle. Few Mucoromycota and Chytridiomycota were reported to infect marine animals. Fungal diseases documented in this review likely represent a fraction of fungal diseases in the ocean, where it was estimated to be inhabited by 2.15 million animal species. Intensification of aquaculture practices, global warming and marine pollution may increase fungal disease outbreak of marine animals. All the topics mentioned above will be discussed in greater details in this review.