Fungal Biology Reviews最新文献

Mushrooms have long been considered as delicacies as well as used as important dietary supplements and food. However, there are major concerns with poisonous mushrooms as these pose threats to public health and safety. In this paper, we provide a review focusing on poisonous mushrooms, their toxins, symptoms and utilizations. In addition, this paper establishes a poisonous mushroom list which includes 643 species from two phyla, 16 orders, 51 families and 148 genera. The toxicity of all these species was verified and 332 species were ranked as P1 signifying that these species have toxic studies and or clinical poisoning case records and 311 species were P2 meaning they had previously been recorded as poisonous in other studies. Furthermore, we discuss advances in technology including how genomic studies could be used as a breakthrough tool in the field of toxic mushrooms. With this comprehensive review, we aim to promote public awareness of poisonous mushrooms, including how to avoid mushroom poisoning, and how to better utilize poisonous mushroom resources.

Intragenomic variation is the molecular variation within the genome among repetitive DNA. As a multigene family, nuclear ribosomal DNA (rDNA) has been widely used in fungal taxonomy for their ease in amplification and suitable variability to attain various levels of taxonomic resolution. At the intraspecific level, rDNA is believed to be under concerted evolution and the internal transcribed spacers (ITS) region is actually accepted as a universal barcoding marker for fungi. However, documentation of intragenomic variation of rDNA indicated that it can be problematic in species delimitation and identification. Fungal taxonomic studies have not generally taken into account the intragenomic variation of rDNA in a systematic manner. In this review, our objective is to address the definition, the origin and the mechanisms for maintenance of intragenomic variation, as well as its implication in the domain of fungal molecular taxonomy, particularly for species delimitation, identification and DNA barcoding. With advanced sequencing technologies (second and third generations), we also addressed how these technologies can be used to study the intragenomic variation of rDNA and also how the intragenomic variation will impact on DNA barcoding via high-throughput sequencing.

Nutritional immunity is one of the strategies employed by the host to combat invading pathogens. It consists of actively controlling micronutrient bioavailability in the site of infection to hinder microbial growth. The role of manganese in cell biology and nutritional immunity for bacterial pathogens is well understood, but data regarding fungi are still limited. Fungi have evolved complex regulatory systems to acquire, distribute, and utilize manganese. Therefore, the disruption of manganese homeostasis in pathogenic fungi may lead to severe phenotypes and impact virulence. Because the host presents tools for manganese sequestration, and this condition can reduce the growth of important fungal pathogens such as Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans, it is feasible to suppose that manganese nutritional immunity could play an important role in fungal infections. However, direct evidence is still lacking, and little is known about manganese homeostasis, nutritional immunity, and specific adaptations in individual species of fungal pathogens. In this opinion, we present the current body of knowledge about these subjects, arguing about manganese importance in host–pathogen interactions.

Entomopathogenic fungi (EPF) infect insects and are of interest for understanding host-pathogen interactions and biological control of insect pests. The fruit fly Drosophila melanogaster offers an excellent model system for exploring the biology of EPF and their interactions with insects. In this review, we describe the advantages of using D. melanogaster as a model system to study EPF and highlight EPF of relevance to agriculture. We also propose possible directions for future research in this area. We predict that in the future, D. melanogaster will continue to be a productive system for understanding the biology of the fungi attacking insects and will no doubt contribute to the future of biological control, conservation and other areas.

Environmental conditions are becoming increasingly challenging in managed ecosystems, especially in agricultural fields, where environmentally friendly solutions are urgently needed. Fungal symbionts offer great opportunities to enhance crop production and ecosystem sustainability under environmental stress. Some fungi are relatively well investigated (e.g., arbuscular mycorrhiza) and regularly used in commercial products, while others, such as fungal endophytes, are not well-known in this market, yet. Here, we review I) the characteristics and benefits, II) the advantages and challenges of principal isolation, preservation, inoculation, and field applications methods, and III) the environmental stress resistance mechanisms for different beneficial fungi. Utilization of mycorrhizae is still facing many challenges, particularly in terms of acquiring pure cultures and successfully establishing their symbiosis in the field. Effects of mycorrhizal associations on the above-ground organs through molecular mechanisms are not fully understood. Although biochemical values of some endophytes are well recognized, molecular mechanisms involved in endophytic-induced stress tolerance are poorly known. Fungal endophytes present several important advantages over mycorrhizal fungi including broader host range as well as straightforward isolation and application protocols. Further studies are necessary for selecting the best strains and communities, producing inoculum on a large-scale, and understanding the potential environmental hazards.

eEF1Bγs are proteins found in all eukaryotes and have a role in protein translation, being part of the nucleotide exchange factor eEF1B of the elongation factor complex 1. They are unique because of their organization as a fusion between a glutathione transferase (GST) domain and an elongation factor EF1G (PF00647) domain. The main described function of the GST domain in eEF1Bγ is to ensure the proper scaffolding of the different subunits in the eEF1B complex, by interacting with eEF1Bα subunit. Several evidences also suggest that this domain has a role in cellular redox control because it displays enzymatic activity using glutathione as co-substrate. This opens the question of a dual role of eEF1Bγ in cells both in protein translation and stress response, either in a concomitant or competitive way. By analyzing the diversity of eEF1Bγ sequences in fungi, we show that this class of proteins is subjected to diversification within these microorganisms. The challenge is now to understand the impact of such diversification in eEF1Bγ functions both related to protein translation and stress response, and whether this could have driven the ability of fungi to adapt to constraints.

Chitinases (EC 3.2.1.14) are the glycoside hydrolases (GH) that catalyse the cleavage of β-(1,4) glycosidic linkages of chitin, which is a key element of fungal cell wall and insect's exoskeletons. Fungi have been considered as an excellent source for the production of extracellular chitinases, which could further be employed for chitin degradation to generate a range of bioactive chito-derivatives, i.e., oligosaccharides and glucosamine. Moreover, chitinases have diverse roles in various physiological functions, i.e., autolysis, cell wall remodeling, mycoparasitism and biocontrol. The advent of technology led to the sequencing of several fungal genomes and enabled the manipulation of novel effective chitinase genes to investigate their mechanistic and structural insights to decode the variabilities in chitin degradation. Further, the comprehensible understanding of attributes including substrate-binding sites and catalytic domains could give an insight into chitin catabolism for value-added products development. The review summarized various aspects of fungal chitinases viz. structure, mechanism, classification, properties, functions and application in the present precis. The study has also underlined the recent research related to the framework of substrate-binding clefts in fungal chitinases and its correlation with the hydrolytic and transglycosylation (TG) activity for the production of oligosaccharides with variable degrees of polymerization.