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The ascomycetous fungus Nectria haematococca, (asexual name Fusarium solani), is a member of a group of >50 species known as the \"Fusarium solani species complex\". Members of this complex have diverse biological properties including the ability to cause disease on >100 genera of plants and opportunistic infections in humans. The current research analyzed the most extensively studied member of this complex, N. haematococca mating population VI (MPVI). Several genes controlling the ability of individual isolates of this species to colonize specific habitats are located on supernumerary chromosomes. Optical mapping revealed that the sequenced isolate has 17 chromosomes ranging from 530 kb to 6.52 Mb and that the physical size of the genome, 54.43 Mb, and the number of predicted genes, 15,707, are among the largest reported for ascomycetes. Two classes of genes have contributed to gene expansion: specific genes that are not found in other fungi including its closest sequenced relative, Fusarium graminearum; and genes that commonly occur as single copies in other fungi but are present as multiple copies in N. haematococca MPVI. Some of these additional genes appear to have resulted from gene duplication events, while others may have been acquired through horizontal gene transfer. The supernumerary nature of three chromosomes, 14, 15, and 17, was confirmed by their absence in pulsed field gel electrophoresis experiments of some isolates and by demonstrating that these isolates lacked chromosome-specific sequences found on the ends of these chromosomes. These supernumerary chromosomes contain more repeat sequences, are enriched in unique and duplicated genes, and have a lower G+C content in comparison to the other chromosomes. Although the origin(s) of the extra genes and the supernumerary chromosomes is not known, the gene expansion and its large genome size are consistent with this species' diverse range of habitats. Furthermore, the presence of unique genes on supernumerary chromosomes might account for individual isolates having different environmental niches

The TMEM16 family of proteins, also known as anoctamins, features a remarkable functional diversity. This family contains the long sought-after Ca 2+ -activated chloride channels as well as lipid scramblases and cation channels. Here we present the crystal structure of a TMEM16 family member from the fungus Nectria haematococca that operates as a Ca 2+ -activated lipid scramblase. Each subunit of the homodimeric protein contains ten transmembrane helices and a hydrophilic membrane-traversing cavity that is exposed to the lipid bilayer as a potential site of catalysis. This cavity harbours a conserved Ca 2+ -binding site located within the hydrophobic core of the membrane. Mutations of residues involved in Ca 2+ coordination affect both lipid scrambling in N. haematococca TMEM16 and ion conduction in the Cl − channel TMEM16A. The structure reveals the general architecture of the family and its mode of Ca 2+ activation. It also provides insight into potential scrambling mechanisms and serves as a framework to unravel the conduction of ions in certain TMEM16 proteins. The authors describe the structure of a Ca 2+ -activated lipid scramblase which catalyses the passive movement of lipids between the two leaflets of a lipid bilayer; the structure reveals the location of a regulatory calcium-binding site embedded within the membrane and the presence of a hydrophilic membrane-traversing cavity that is exposed to the lipid bilayer, where catalysis is likely to occur. Chloride channel structures In two manuscripts published in this issue of Nature , the authors have solved X-ray crystal structures of two Ca 2+ -activated chloride channels — the first published structures for this type of channel. Janine Brunner et al . crystallized lipid scramblase, a membrane protein that catalyses the passive movement of lipids between the two leaflets of a bilayer. The structure reveals a hydrophilic membrane-traversing cavity that is exposed to the lipid bilayer, where catalysis likely occurs. Veronica Dickson et al . crystallized bestrophin-1. Proteins of this family open their anion-selective pores in response to a rise in the intracellular Ca 2+ concentration. The structure shows that Ca 2+ binds to the cytosolic region of a pentameric transmembrane channel and reveals that the pore is 95 Å long, with at least fifteen distinct anion-binding sites.

We used 454 sequencing of the internal transcribed spacer region to characterize fungal communities in tallgrass prairie soils subdivided into strata 0-10, 10-20, 30-40 and 50-60 cm deep. The dataset included more than 14 000 fungal sequences distributed across Basidiomycota, Ascomycota, basal fungal lineages and Glomeromycota in order of decreasing frequency. As expected the community richness and diversity estimators tended to decrease with increasing depth. Although species richness was significantly reduced for samples from the deeper profiles, even the deepest stratum sampled contained richness of more than a third of that in the topmost stratum. More importantly, nonparametric multidimensional scaling (NMS) ordination analyses indicated that the fungal communities differed across vertical profiles, although only the topmost and deepest strata were significantly different when the NMS axis scores were compared by ANOVA. These results emphasize the importance of considering the fungal communities across the vertical strata because the deeper soil horizons might maintain a distinct community composition and thus contribute greatly to overall richness. The majority of operational taxonomic units (OTUs) declined in frequency with increasing depth, although a linear regression analysis indicated that some increased with increasing depth. The OTUs and BLAST-assigned taxa that showed increasing frequencies were mainly unculturable fungi, but some showed likely affinities to families Nectriaceae and Venturiaceae or to genus Pachnocybe. Although the ecological roles of the fungi in the deeper strata remain uncertain, we hypothesize that the fungi with preferences for deeper soil have adequate access to substrates and possess environmental tolerances that enable their persistence in those environments.

Compared to ( S )-selective amine transaminase (( S )-AT), the ( R )-selective counterpart (( R )-AT) has been less studied. As such, a simplified “Motif Sequence Blast” search (Höhne et al. Nat Chem Biol 6:807–813, 2010 ) was carried out to identify new ( R )-ATs from the protein databases. The combined conserved sequence motifs of ( R )-ATs based on the previous in silico method of predicting ( R )-selective amine transaminase were used as the template sequence for BLASTP search at default settings in NCBI, and six candidate sequences were identified. These putative ( R )-AT genes were synthesized and overexpressed in Escherichia coli . Among them, five new ( R )-ATs were expressed as soluble protein and showed unusual substrate specificity and high stereoselectivity. Furthermore, several unnatural amino acids, such as d -alanine, d -2-aminobutyric acid, and d -norvaline, were synthesized via the ( R )-AT-catalyzed amino transfer reaction to the corresponding keto acids. Optically pure ( S )-amines were also obtained by kinetic resolution of racemic amines catalyzed with these new ( R )-ATs. Therefore, the Motif Sequence Blast search offers a quick and effective method for in silico identification of new ( R )-ATs, and the newly identified ( R )-ATs are attractive additions to the toolbox of ( R )-ATs for further study and industrial application.

During recent years, a new disease of Siberian fir ( A. sibirica ) emerged in Central Siberia, exhibiting symptoms of stem/branch deformation, cambium necrosis, and dieback of branches and twigs, the causal agent remaining unknown. The aim was to identify agent of the disease and to investigate its pathogenicity to A. sibirica and Norway spruce ( Picea abies ). Symptomatic tissues of fir were subjected to pure culture isolation of anticipated pathogen(s). Obtained isolates were subjected to molecular identification, phylogenetic analyses, and pathogenicity tests with A. sibirica saplings, and seeds and seedlings of A. sibirica and P. abies . The study demonstrated that, (i) most commonly isolated fungus from canker wounds of A. sibirica exhibited Acremonium- like anamorphs; (ii) phylogeny demonstrated that investigated fungi belong to genus Corinectria , but are genetically well separated from other worldwide known Corinectria spp.; (iii) one species of isolated fungi has the capacity to cause the disease and kill A. sibirica saplings and seedlings, but also seedlings of P. abies . Guidelines for future research were defined in order to generate needed information on species description, its origin and ecology, and estimation of potential risks upon the eventual invasion of the pathogen to new geographic areas, in particular of Europe.

Prions are infectious proteins propagating as self-perpetuating amyloid polymers. The [Het-s] prion of Podospora anserina is involved in a cell death process associated with non-self recognition. The prion forming domain (PFD) of HET-s adopts a β-solenoid amyloid structure characterized by the two fold repetition of an elementary triangular motif. [Het-s] induces cell death when interacting with HET-S, an allelic variant of HET-s. When templated by [Het-s], HET-S undergoes a trans-conformation, relocates to the cell membrane and induces toxicity. Here, comparing HET-s homologs from different species, we devise a consensus for the HET-s elementary triangular motif. We use this motif to screen genomic databases and find a match to the N-terminus of NWD2, a STAND protein, encoded by the gene immediately adjacent to het-S. STAND proteins are signal transducing ATPases which undergo ligand-induced oligomerisation. Homology modelling predicts that the NWD2 N-terminal region adopts a HET-s-like fold. We propose that upon NWD2 oligomerisation, these N-terminal extensions adopt the β-solenoid fold and template HET-S to adopt the amyloid fold and trigger toxicity. We extend this model to a putative prion, the σ infectious element in Nectria haematococca, because the s locus controlling propagation of σ also encodes a STAND protein and displays analogous features. Comparative genomic analyses indicate evolutionary conservation of these STAND/prion-like gene pairs, identify a number of novel prion candidates and define, in addition to the HET-s PFD motif, two distinct, novel putative PFD-like motifs. We suggest the existence, in the fungal kingdom, of a widespread and evolutionarily conserved mode of signal transduction based on the transmission of an amyloid-fold from a NOD-like STAND receptor protein to an effector protein.

A new species with remarkable morphology, Nectria eustromatica, is described, based on morphology of the teleomorph and anamorph, ecology and molecular phylogenetic analyses. Nectria eustromatica is characterized by sphaeroid perithecia immersed in pseudoparenchymatous stromata formed singly or collectively on a subiculum. Despite its deviating teleomorph morphology, it is placed within Nectria sensu stricto in phylogenetic analyses of a combined dataset of LSU, ITS, rpb2 and tef1 sequences with high internal support. Nectria eustromatica has been collected specifically on Hippocrepis (Coronilla) emerus in southern Europe. The anamorph of N. eustromatica shares morphological traits with the genera Stilbella and Tubercularia but produces non-phialidic macroconidia in addition to phialoconidia.

Karyotypes of the cucurbit pathogen Nectria haematococca MPI (anamorph Fusarium solani f. sp. cucurbitae race 1) was studied using the two standard strains ATCC18098 and ATCC18099. Complete separation of all chromosomes was difficult with pulsed field gel electrophoresis due to both the large size and co-migration of chromosomes. In contrast, cytological karyotyping was done successfully with fluorescence microscopy combined with the germ tube burst method for sample preparation to visualize mitotic metaphase chromosomes. For each strain the basic chromosome number (CN) was nine, which revises previous chromosome estimates of n = 4. Chromosomes were morphologically characterized by their sizes, intensely fluorescing segments, and protrusion of rDNA. In addition to the basic chromosome complement, ATCC18098 had a mini-chromosome of ~410 kb present as a single copy in somatic nuclei. Chromosome fluorescence in situ hybridization indicated that this mini-chromosome is not a derivative from the other chromosomes in the genome. In addition, crossing experiments suggested that it was transmitted in a Mendelian manner to the ascospore progeny.

Background Mango is an economically important fruit tree with rich genetic diversity, but has been threatened by a diverse range of pathogens, causing substantial losses annually. While the plant-associated microbiomes are well studied, the assembly patterns and composition of phyllosphere microbial communities for deciphering potential pathogenic and beneficial microbiota during the mango fruit-setting phase remain largely unexplored. Results This study profiled the bacterial and fungal communities in mango leaves, flowers, and fruitlets using high-throughput amplicon sequencing. Both flowers and fruitlets exhibited significantly less diverse microbial communities than leaves, and the bacterial and fungal microbiota compositions of all three organs were distinct from one another. Importantly, organ-specific preferences were observed among the dominant bacterial families, with mango flowers characterized by a high abundance of Erwiniaceae, fruitlets by Acetobacteraceae, and leaves by Microbacteriaceae and Bifidobacteriaceae. In contrast, fungal families were less differentiated, with only Didymellaceae and Symmetrosporaceae showing leaf-specific enrichment relative to flowers and fruitlets. Analysis of the shared microbial genera across the three phyllosphere organs revealed the presence of core bacterial taxa Pseudomonas and Sphingomonas , while the fungal core genera were Alternaria , Aureobasidium , Cladosporium , Epicoccum , Fusarium , Hannaella , Nectria , Neodidymella , and Vishniacozyma . Notably, several of these concurrently detected microbial genera have been previously documented as either pathogenic (e.g., Alternaria , Cladosporium and Fusarium ) or beneficial ( Aureobasidium , Vishniacozyma , Sphingomonas and Pseudomonas ). Furthermore, we found that the mango phyllosphere bacterial and fungal communities were established by parallel selection of the microbiota, instead of consecutive selection. Deciphering the functional profile of the phyllosphere microbiota revealed the association of microbial taxa with functions such as chemoheterotrophy, aerobic chemoheterotrophy, fermentation, aromatic compound degradation, plant pathogens, endophytes, and saprotrophs, indicating a balanced ecosystem in which future fruit health outcomes may be determined by subtle shifts in the microbial community structure. Conclusion Our findings offer a checklist of the core beneficial and pathogenic microbes inhabiting the mango phyllosphere, while also highlighting the selective role of mango organs in recruiting specific subsets of microbiota, which can be harnessed for disease protection and improving mango production.

Our previous research has shown that a fungal immunomodulatory protein from Nectria haematococca (FIP-nha) possesses a wide spectrum of anti-tumor activities, and FIP-nha induced A549 apoptosis by negatively regulating the PI3K/Akt signaling pathway based on comparative quantitative proteomics. This study further confirmed that the anti-lung cancer activity of FIP-nha was significantly stronger than that of the reported LZ-8 and FIP-fve. Subsequently, 1H NMR-based metabolomics was applied to comprehensively investigate the underlying mechanism, and a clear separation of FIP-nha-treated and untreated groups was achieved using pattern recognition analysis. Four potential pathways associated with the anti-tumor effect of FIP-nha on A549 cells were identified, and these were mainly involved in glycolysis, taurine and hypotaurine metabolism, fructose and mannose metabolism, and glycerolipid metabolism. Metabolic pathway analysis demonstrated that FIP-nha could induce A549 cell apoptosis partly by regulating the p53 inhibition pathway, which then disrupted the Warburg effect, as well as through other metabolic pathways. Using RT-PCR analysis, FIP-nha-induced apoptosis was confirmed to occur through upregulation of p53 expression. This work highlights the possible use of FIP-nha as a therapeutic adjuvant for lung cancer treatment.