Journal of Fungi最新文献

Cereal crops are affected by one of the most devastating diseases worldwide, known as Fusarium head blight (FHB), with Fusarium graminearum being the most isolated causal pathogen. Another species associated with this disease is Fusarium poae. This species has been considered a relatively weak pathogen compared to F. graminearum, but its importance has increased due to its occurrence in cereal grains worldwide. Considering the advantages of using B. distachyon as a plant model and the importance of F. poae in crops, our study aimed to evaluate the potential use of Brachypodium as a plant model to evaluate the compatible interaction with F. poae. Twelve Brachypodium spp. accessions from different countries were inoculated with a selected F. poae set of isolates. Disease severity, conidial quantification, fungal DNA biomass, and nivalenol quantification were assessed. The results showed a compatible interaction between Brachypodium accessions and Fusarium poae, which allowed the use of the model plant for future plant-pathogen interaction studies.

Candida auris is an emerging multidrug-resistant fungal pathogen causing nosocomial transmission and invasive infections with high mortality. This study aimed to investigate the genetic relationships, enzymatic activities, and drug-resistance profiles of C. auris isolates to evaluate the population and epidemiological diversity of candidiasis in Russia. A total of 112 clinical isolates of C. auris were analyzed from May 2017 to March 2023 in 18 hospitals across Saint Petersburg, the Leningrad Region, and Moscow. Species identification was confirmed by ITS sequencing, and genotyping was performed using 12 short tandem repeat (STR) markers. Antifungal susceptibility was tested using Sensititre™ YeastOne™ plates, and hydrolytic enzyme production was measured by the plate method. ITS sequencing confirmed that all isolates belonged to a single ITS cluster (clades I and III). Fifteen distinct STR genotypes were identified, with genotype I being dominant (n = 53). The most variable of the analyzed markers turned out to be M3-Ia, which was represented in the Russian population by eight different variants. Fluconazole resistance was found in 111 isolates, 17% were resistant to amphotericin B, and 3.6% to 5-flucytosine. Phospholipase activity was strong in most strains, especially in urine isolates (p = 0.014). Conclusion: The predominance of STR genotype I and its variability at the M3-Ia locus suggest its association with nosocomial outbreaks and transmissibility in Russia.

Evidence of unintended introductions of Phytophthora species into native habitats has become increasingly prevalent in California. If not managed adequately, Phytophthora species can become devastating agricultural and forest plant pathogens. Additionally, California's natural areas, characterized by a Mediterranean climate and dominated by chaparral (evergreen, drought-tolerant shrubs) and oak woodlands, lack sufficient baseline knowledge on Phytophthora biology and ecology, hindering effective management efforts. From 2018 to 2021, soil samples were collected from Angeles National Forest lands (Los Angeles County) with the objective of better understanding the diversity and distribution of Phytophthora species in Southern California. Forty sites were surveyed, and soil samples were taken from plant rhizospheres, riverbeds, and off-road vehicle tracks in chaparral and oak woodland areas. From these surveys, fourteen species of Phytophthora were detected, including P. cactorum (subclade 1a), P. multivora (subclade 2c), P. sp. cadmea (subclade 7a), P. taxon 'oakpath' (subclade 8e, first reported in this study), and several clade-6 species, including P. crassamura. Phytophthora species detected in rhizosphere soil were found underneath both symptomatic and asymptomatic plants and were most frequently associated with Salvia mellifera, Quercus agrifolia, and Salix sp. Phytophthora species were present in both chaparral and oak woodland areas and primarily in riparian areas, including detections in off-road tracks, trails, and riverbeds. Although these Mediterranean ecosystems are among the driest and most fire-prone areas in the United States, they harbor a large diversity of Phytophthora species, indicating a potential risk for disease for native Californian vegetation.

ADP-ribosylation is a reversible modification of proteins and nucleic acids, which controls major cellular processes, including DNA damage repair, cell proliferation and differentiation, metabolism, stress, and immunity in plants and animals. The involvement of ADP-ribosylation in the life cycle of Dictyostelium and some filamentous fungi has also been demonstrated. However, the role of this process in pathogenic oomycetes has never been addressed. Here, we show that the Phytophthora infestans genome contains two PARP-like protein genes (PiPARP1 and PiPARP2), and provide evidence of PARylation activity for one of them (PiPARP2). Using dsRNA-mediated RNA silencing of the PiPARP2 gene and chemical (pharmacological) inhibition of PARP activity by 3-aminobenzamide (3AB) PARP inhibitor, we demonstrate the critical functional role of ADP-ribosylation in Phytophthora mycelium growth. Virulence test on detached leaves also suggests an important role of ADP-ribosylation in Phytophthora host plant colonisation and pathogenesis. On a practical level, our data suggest that targeting the PARylation system may constitute a novel powerful approach for the management of Phytophthora diseases.

Apples and strawberries hold significant commercial and nutritional value but face pre- and post-harvest spoilage due to infections by Botrytis cinerea. While spoilage is conventionally managed using synthetic chemicals, there is a growing interest in utilising yeasts as biological control agents. This study aimed to assess the antifungal potential of non-Saccharomyces yeasts Suhomyces pyralidae, Meyerozyma guilliermondii, Pichia kluyveri, Zygoascus hellenicus, and Aureobasidium melanogenum against three B. cinerea strains (B05.10, IWBT-FF1, and PPRI 30807) on agar plates and in post-harvest trials on apples and strawberries. Aureobasidium melanogenum exhibited a broad range of extracellular enzyme production and inhibition rates of 55%, 52%, and 40% against the strains. In volatile organic compound (VOC) assays, P. kluyveri and S. pyralidae achieved 79% and 56% inhibition, respectively, with VOCs like isobutanol, isoamyl alcohol, 2-phenylethanol, isoamyl acetate, and 2-phenethyl acetate identified. In post-harvest trials, S. pyralidae was most effective on apples, with inhibition rates up to of 64%. The commercial fungicide Captan and S. pyralidae and P. kluyveri achieved 100% inhibition against the B. cinerea strains B05.10 and IWBT-FF1 on strawberries. These findings highlight the potential of the selected yeast species as biological control agents against B. cinerea, warranting further research into their application in commercial fruit protection.

The Cordycipitaceae family of insecticidal fungi is widely distributed in nature, is the most complex in the order Hypocreales (Ascomycota), with members displaying a diversity of morphological characteristics and insect host ranges. Based on Bayesian evolutionary analysis of five genomic loci(the small subunit of ribosomal RNA (SSU) gene, the large subunit of ribosomal RNA (LSU) gene, the translation elongation factor 1-α (tef1-α) gene, the largest subunit of RNA polymerase II (rpb1), and the second largest subunit of RNA polymerase II (rpb2), we inferred the divergence times for members of the Cordycipitaceae, improving the internal phylogeny of this fungal family. Molecular clock analyses indicate that the ancestor of Akanthomyces sensu lato occurred in the Paleogene period (34.57 Mya, 95% HPD: 31.41-37.67 Mya), and that most species appeared in the Neogene period. The historical biogeography of Akanthomyces sensu lato was reconstructed using reconstructing ancestral state in phylogenies (RASP) analysis, indicating that it most likely originated in Asia. Combined morphological characterization and phylogenetic analyses were used to identify and taxonomically place five species within Cordycipitaceae. These include the following: (i) two new species, namely Akanthomyces baishanensis sp. nov. and Samsoniella sanmingense sp. nov., (ii) a new record species isolated from infected Lepidopteran host, Blackwellomyces lateris, (iii) a new record species in the genus Niveomyces, with sporothrix-like asexual morphs, namely N. multisynnematus, isolated from dipteran insects (flies), and (iv) a known species of the (hyper-) mycoparasite, Liangia sinensis, isolated from the fungus Ophiocordyceps globiceps (Ophiocordycipitaceae) growing on a dipteran host. Our data provide a significant addition to the diversity, ecology, and evolutionary aspects of the Cordycipitaceae.

Globally, forest decline and tree mortality are rising due to climate change. As one of the important afforestation trees in northeast China, Pinus sylvestris var. mongolica is suffering from forest decline and the accompanying pests. Certain fungi from the ophiostomatalean contribute to forest pest outbreaks and can be pathogenic to pine trees. However, only a limited number of ophiostomatalean fungi associated with beetles infesting Pinus sylvestris var. mongolica have been identified. In this study, 293 ophiostomatalean fungi were isolated from Acanthocinus griseus, Ips chinensis, and Pissodes nitidus infesting Pinus sylvestris var. mongolica in Heilongjiang Province, including Graphilbum griseum sp. nov., Gra. nitidum sp. nov., Graphilbum sp., and Ophiostoma ips. Ophiostoma ips was the dominant species, followed by Graphilbum sp., Graphilbum griseum, and Gra. nitidum, which accounted for 73.38, 17.41, 7.17, and 2.05% of the isolated ophiostomatalean fungi, respectively. Fungi associated with different beetles are diverse, even within the same host. This study deepens our understanding of the pest-associated fungi of P. sylvestris var. mongolica and provides a basis for exploring the causes of forest decline.

The fungal pathogens Fusarium keratoplasticum and Fusarium falciforme are responsible for the emerging infectious disease named sea turtle egg fusariosis (STEF). This disease affects all sea turtle species throughout the world, causing low hatching success and mass mortalities. In this study, we investigated the potential use of widely available and easy-to-handle eggs of the invasive alien red-eared slider turtle, Trachemys scripta, as part of an in vivo host model to improve our knowledge of the biological properties of the pathogens responsible of the STEF. Specifically, we performed in vivo experiments, in which T. scripta eggs were challenged with conidia of F. keratoplasticum isolated from diseased sea turtle eggs. We found that the pathogen could colonize and develop similar signs to those observed in nature and fulfill Koch's postulates. The pathogen showed high virulence properties (e.g., high disease incidence, severity, and low hatching success) and its ability to modify the pH in both the egg surface and culture media, confirming previously described fungal pathogen models. These results support the use of T. scripta as an experimental in vivo host model for studying the biological characteristics of STEF, thus providing valuable insights into the mechanisms underlying the emergence of this fungal disease.

Since the domestication of plants, pathogenic fungi have consistently threatened crop production, evolving genetically to develop increased virulence under various selection pressures. Understanding their evolutionary trends is crucial for predicting and designing control measures against future disease outbreaks. This paper reviews the evolution of fungal pathogens from natural habitats to agricultural settings, focusing on eight significant phytopathogens: Pyricularia oryzae, Botrytis cinerea, Puccinia spp., Fusarium graminearum, F. oxysporum, Blumeria graminis, Zymoseptoria tritici, and Colletotrichum spp. Also, we explore the mechanism used to understand evolutionary trends in these fungi. The studied pathogens have evolved in agroecosystems through either (1) introduction from elsewhere; or (2) local origins involving co-evolution with host plants, host shifts, or genetic variations within existing strains. Genetic variation, generated via sexual recombination and various asexual mechanisms, often drives pathogen evolution. While sexual recombination is rare and mainly occurs at the center of origin of the pathogen, asexual mechanisms such as mutations, parasexual recombination, horizontal gene or chromosome transfer, and chromosomal structural variations are predominant. Farming practices like mono-cropping resistant cultivars and prolonged use of fungicides with the same mode of action can drive the emergence of new pathotypes. Furthermore, host range does not necessarily impact pathogen adaptation and evolution. Although halting pathogen evolution is impractical, its pace can be slowed by managing selective pressures, optimizing farming practices, and enforcing quarantine regulations. The study of pathogen evolution has been transformed by advancements in molecular biology, genomics, and bioinformatics, utilizing methods like next-generation sequencing, comparative genomics, transcriptomics and population genomics. However, continuous research remains essential to monitor how pathogens evolve over time and to develop proactive strategies that mitigate their impact on agriculture.

We investigated the molecular mechanisms underlying azole resistance in seven Candida tropicalis isolates that caused candidemia and candiduria in Paraná, Brazil (2016-2022). Biofilm production, antifungal susceptibility testing, multilocus sequence typing, amplification and sequencing of ERG11, and quantification of ERG11, MDR1, and CDR1 expression levels were performed. Notably, five isolates (71.4%) were from urine samples and two (28.6%) were from blood samples. All strains were biofilm producers, with levels ranging from moderate to strong. The minimum inhibitory concentration (MIC) values ranged from 8->64 mg/L for fluconazole and 0.25-1 mg/L for voriconazole. All isolates had mutations in ERG11; Y132F and Y257N were predominant (71.4%), followed by Y132F and S154F (14.3%) and Y257H (14.3%). No differences in ERG11 expression were found between the susceptible and resistant groups, but MDR1 and CDR1 were more highly expressed in the susceptible isolates. All the isolates contained previously unassigned diploid sequence types. The emergence of C. tropicalis azole resistance has been previously described in Brazil; however, the presence of resistant isolates in urine highlights the need for surveillance resistant strains in both urinary and invasive contexts. In our study mutations in ERG11 were the main resistance mechanism identified in C. tropicalis.