1,720,999 research outputs found
Fungal lipids.Biosynthesis and signalling during plant-pathogen interaction
No full textLipids occur in fungi as major constituents of the membrane systems and minor component in the cell wall; they can store energy in the lipid bodies and, in some cases, they can act as intra-extracellular signals. Fungi contain a various set of lipids, including fatty acids, oxylipins, sphingolipids, phospholipids, glycolipids, and sterols. Current studies in lipids suggest their additional role in cell signalling; for instance, host-pathogen exchange lipid signals at the interface during their interaction. This review aims examining those fungal lipid classes involved in the pathogenic interaction with the host plants. The lipid signals may trigger host immune response as well as functioning as virulence factors altering the lipid homeostasis of the host cells
LIPID MEDIATED CROSS-KINGDOM COMMUNICATION BETWEEN HOSTS AND PATHOGENS
No full textWhich are the main biological functions of lipids? Lipids have a structural role in forming cell membranes and play a role in energy storage. Current knowledge indicates that the lipids have an additional role in cell signaling. When a fungal pathogen contacts the host, the cell surfaces can exchange signals, among which, several are lipids. Lipids occur in fungi not only as major constituents of the membrane system, but also as cell wall components, as storage material in abundant and readily observed lipid bodies, and in some cases, as extracellular products. Fungi contain a various set of lipids, including fatty acids, oxylipins, sphingolipids, phospholipids, glycolipids and sterols. We are going to examine some fungal lipid classes involved in the pathogenic interaction with the host. These signals can confer different information. In some cases can trigger host immune responses; conversely, they may function as virulence factors altering the normal homeostasis of the host or even causing the death
Nanopore hybrid assembly of Biscogniauxia mediterranea isolated from Quercus cerris affected by charcoal disease in an endangered coastal wood
Full text linkBiscogniauxia mediterraneais the causal agent of charcoal disease, affectingoak decline under the trigger of various biotic and abiotic factors, including climatechange. Here, we report the genome assembly of an ItalianB. mediterraneastrain obtainedusing hybrid sequencing technologies combining long and short reads
Next Generation Sequencing applied to Cultural Heritage: detection of microorganisms present on the parchment surface of an ancient Gradual of the 13th century
No full textThe original integrity of Cultural Heritage (CH) may be threatened by the microbial deterioration. Conservation strategies to prevent biodeterioration needs the identification of microorganisms colonizing the substrate. In the last decades microbial monitoring has relied on culture-dependent methods. The most significant limit is the cultivability of the microorganisms and their following identification. In recent years, the development of next generation sequencing (NGS) approach provided new tools for their identification.
We design and apply a diagnostic protocol on an ancient Gradual of the 13th century by using a targeted metagenomic analysis carried out by Nanopore Technologies consisting of: 1) Non-invasive sampling (sterile swab); 2) DNA extraction; 3) whole genome pre-amplification (WGA); 4) PCR amplification of conserved regions ITS (fungi), 16S (bacteria) and 18S (eukaryotes); and 5) amplicon-sequencing with MinION (ONT). Fungal species identified as Serpula lacrymans, Postia, and Alternaria alternata, may be related to wood degradation (in fact the cover of the manuscript is made of wood), while Aspergillus sp. and Penicillium sp. to parchment degradation. For bacteria instead: Cutibacterium acnes, Finegoldia magna, Bacillus mansiliensis, and Staphylococcus epidermidis, all related to the human skin flora, and which therefore could be present due to handling over the years. Their presence could pose a risk for the Gradual preservation since these species can degrade collagen naturally present in the parchment. This work shows that the NGS applied to CH may produce valuable insight, for the diagnostic of potential threats of biodeterioration
Effects of climate change on the distribution of Fusarium spp. in Italy
No full textThis work studies the incidence of Fusarium spp. on wheat kernels about current and future climatic scenarios (CSs) in Italy. Epidemiological analyses were performed from 2007 to 2013 and the dataset was used for correlations between the disease incidence of five Fusarium species monitored in Italy (Fusarium graminearum, F. langsethiae, F. sporotrichioides, F. poae and F. avenaceum) and climatic and geographical parameters. Probabilistic-based modelling of the actual distribution of Fusarium spp. was achieved by using the Zero-inflated Poisson regression. The probabilistic geographical distribution of the Fusarium species was assessed by applying future CSs (RCPs 4.5 and 8.5). The shift from current to future CSs highlighted changes on a national and regional scale. The tightening of environmental conditions from the RCP4.5 to 8.5 resulted in a sporadic presence of F. avenaceum only in the northern Italy. F. graminearum was plentifully present in the current climate, but the tightening of minimum and maximum temperatures and the decrease of precipitation between May-June in the RCP8.5 no longer represents the optimum conditions for it. F. langsethiae was currently distributed in all of Italy, increasing in the probability of detecting it from high to low latitudes and from low to high longitudes under the RCP8.5. F. poae grows and develops in arid climatic conditions. Under the CSs, it showed high incidence probabilities in the southeast and northeast areas of Italy. F. sporotrichioides is scarcely present in Italy, found at high latitudes and in the central areas. Climate change (CC) altered this distribution, and the chances of discovering it increased significantly moving to southern Italy. Overall, the study shows that CC is likely to lead to an increase in the incidence of Fusarium species on Italian wheat, highlighting the importance of strategies to mitigate the effects of CC on wheat production, quality, and safety
The Neolithic site “La Marmotta”. DNA metabarcoding to identify the microbial deterioration of waterlogged archeological wood
Full text linkIntroduction: The evaluation of biological degradation of waterlogged archeological wood is crucial to choose the conservative and protective treatments to be applied to the wooden material. The waterlogged environmental conditions are characterized by oxygen scarcity, only allowing the growth of adapted microbes capable to degrade the organic wooden material, mainly erosion bacteria and softrot fungi. In this work, we characterized and evaluated the biodegradation state and the microbial communities of wooden fragments preserved in storage tanks. These were preserved by waterlogging within the Neolithic village “La Marmotta,” currently found under the Bracciano Lake (Lazio, Italy). Methods: The waterlogged wood samples were first identified taxonomically with an optical microscope, also allowing an evaluation of their preservation state. The microbial community was then evaluated through the sequencing of Internal Transcribed Spacer sequences for fungi and 16S for bacteria with the Oxford Nanopore Technologies (ONT) MinION platform. Results: The identified microbial community appears to be consistent with the waterlogged samples, as many bacteria attributable to the erosion of wood and ligninolytic fungi have been sequenced. Discussion: The reported results highlight the first use of targeted metabarcoding by ONT applied to study the biodeterioration of waterlogged archeological wood
Quantitative profiling of oxylipins through comprehensive LC-MS/MS analysis of Fusarium verticillioides and maize kernels
No full textAnalysis of the expression of genes related to oxylipin biosynthesis in Fusarium verticillioides and maize kernels during their interaction
No full textFusarium verticillioides is a pathogen that can cause ear and stalk rot in maize. Under suitable environmental conditions, this fungus produces large amount of fumonisins, a potential carcinogenic to humans and animals classified as IARC2B. Recent studies have shown that pathogen and host exchange an oxylipin-based cross talk during their interaction. This study was aimed at investigating whether environmental conditions, namely water activity (aw) at 0.90 and 20°C, which are the thresholds for F. verticillioides development, affect the maize/fungal oxylipin gene expression profile. Fungal Fvlds1-3, Fvlox, Zmlox3 and the maize defense-related ZmPR1 genes significantly changed their expression after infection at 0.90 aw and 20°C. Moreover, the expression of maize genes peaked after that of fungal genes, indicating that, under these experimental conditions, plant and pathogen coordinate the oxylipin gene expression reciprocally. This kind of modulation of fungal and plant gene expression is suggestive of the “zig zag model” proposed for other plant-pathogen interaction systems
The potential of plant-based bioactive compounds on inhibition of aflatoxin B1 biosynthesis and down-regulation of aflR, aflM and aflP genes
Full text linkThe use of plant extracts in pre- and post-harvest disease management of agricultural crops to cope with aflatoxin B1 contamination has shown great promise due to their capability in managing toxins and safe-keeping the quality. We investigated the anti-aflatoxigenic effect of multiple doses of eight plant extracts (Heracleum persicum, Peganum harmala, Crocus sativus, Trachyspermum ammi, Rosmarinus officinalis, Anethum graveolens, Berberis vulgaris, Berberis thunbergii) on Aspergillus flavus via LC-MS and the down-regulatory effect of them on aflR, aflM and aflP genes involved in the aflatoxin B1 biosynthesis pathway using RT-qPCR analyses. Our results showed that H. persicum (4 mg/mL), P. harmala (6 mg/mL) and T. ammi (2 mg/mL) completely stopped the production of aflatoxin B1, without inducing significant changes in A. flavus growth. Furthermore, our findings showed a highly significant correlation between the gene expression and the aflatoxin B1 biosynthesis, such that certain doses of the extracts reduced or blocked the expression of the aflR, aflM and aflP and consequently reduced the synthesis of aflatoxin B1. Interestingly, compared to the regulatory gene (aflR), the down-regulation of expression in the structural genes (aflM and aflP) was more consistent and correlated with the inhibition of aflatoxin B1 production. Overall, this study reveals the anti-aflatoxigenic mechanisms of the selected plant extracts at the gene expression level and provides evidence for their use in plant and crop protection
Gene deletion and genome perturbation
No full textFusarium verticillioides causes ear rot disease in maize and its contamination with fumonisins, mycotoxins toxic to humans and livestock. Lipids, and their oxidized forms, may drive the fate of this disease. In a previous study, we have explored the role of oxylipins in this interaction by deleting by standard transformation procedures a linoleate diol synthase-coding gene, lds1, in F. verticillioides. A profound phenotypic diversity in the mutants generated, has prompted us to investigate deeper the whole genome of two lds1-deleted strains. Surprisingly, bioinformatic analyses pinpoint significant differences in the genome sequences emerged between the wild type and the lds1-mutants further than those trivially attributable to the deletion of the lds1 locus such as single nucleotide polymorphisms, small deletion/insertion polymorphisms and structural variations. Difference among the three genomes were analyzed by using a high degree of filtering to decrease the bias due to sub-culturing practices and parasexual cycle operating in these fungi. The results suggest the possibility that the effect of a (theoretically) punctual transformation event might have caused an overall genomic instability, and that transformation practices, commonly used in the reverse genetic of fungi, may potentially be responsible of unexpected, stochastic and henceforth off-target rearrangements throughout the genome
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