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Frontiers in Microbiology 2022In the tobacco phyllosphere, some of the microbes may have detrimental effects on plant health, while many may be neutral or even beneficial. Some cannot be cultivated,...
In the tobacco phyllosphere, some of the microbes may have detrimental effects on plant health, while many may be neutral or even beneficial. Some cannot be cultivated, so culture-independent methods are needed to explore microbial diversity. In this study, both metagenetic analysis and traditional culture-dependent methods were used on asymptomatic healthy leaves and symptomatic diseased leaves of tobacco plants. In the culture-independent analysis, asymptomatic leaves had higher microbial diversity and richness than symptomatic leaves. Both asymptomatic and symptomatic leaves contained several potentially pathogenic bacterial and fungal genera. The putative bacterial pathogens, such as species of , , or , and putative fungal pathogens, such as species of , , , , , and , had a higher relative abundance in symptomatic leaves than asymptomatic leaves. FUNGuild analysis indicated that the foliar fungal community also included endophytes, saprotrophs, epiphytes, parasites, and endosymbionts. PICRUSt analysis showed that the dominant functions of the bacterial community in a symptomatic leaf were cellular processes and environmental information processing. In the other five foliar samples, the dominant functions of the bacterial community were genetic information processing, metabolism, and organismal systems. In the traditional culture-dependent method, 47 fungal strains were isolated from 60 symptomatic tobacco leaf fragments bearing leaf spots. Among them, 21 strains of (29%), (14%), (14%), (10%), (10%), (10%), (5%), (5%), and (5%) all fulfilled Koch's postulates and were found to cause disease on detached tobacco leaves in artificial inoculation tests. Symptoms on detached leaves caused by three strains of in artificial inoculation tests were similar to the original disease symptoms in the tobacco field. This study showed that the combined application of culture-dependent and independent methods could give comprehensive insights into microbial composition that each method alone did not reveal.
PubMed: 35572673
DOI: 10.3389/fmicb.2022.843389 -
Fungal Biology Feb 2022Living organisms can induce deterioration of cultural heritage. Conservation strategies aimed at avoiding damage and aiding restoration, require a comprehensive...
Living organisms can induce deterioration of cultural heritage. Conservation strategies aimed at avoiding damage and aiding restoration, require a comprehensive knowledge of structure, chemical composition, and identity of microorganisms that colonize artworks. The National Theatre of Costa Rica (NTCR), a building with historic architecture, houses several oil paintings from the nineteenth century, some with visible signs of biodeterioration. One of them is a large format painting on canvas called La Danza (size 9.83 × 5.13 m) from 1896 by Italian artist Vespasiano Bignami, located on the ceiling of the theatre's foyer. In the present study, we undertook a physicochemical and microbiological study of La Danza to identify the fungal species that inhabit the artwork and are responsible for the damage observed. Scanning electron microscope (SEM) images and attenuated total reflectance - Fourier transform infrared (ATR-FTIR) spectroscopic data indicated that the canvas material is made of hemp, the binder contains linseed oil and lead white, and a material in the inner face of the canvas is mainly composed of beeswax. Fungi were isolated onto potato dextrose agar (PDA) and carboxymethyl cellulose (CMC) agar, and then identified with molecular (BTUB, nrDNA ITS, and TEF1 regions) and morphological methods. Four isolates belonging to the genera Myxospora, Pestalotiopsis, Ustilago, and aff. Penicillium, were obtained. Qualitative tests showed cellulolytic activity in all isolated specimens, confirming their possible role in biodeterioration of the canvas. Phylogenetic and morphological data revealed a new species of Myxospora we name here as Myxospora theatro sp. nov., in reference to NTCR. The findings broaden the knowledge of fungi capable of inhabiting and damaging cultural heritage. They also provide valuable information to develop strategies for conservation and restoration of oil paintings on canvas.
Topics: Costa Rica; Fungi; Paintings; Penicillium; Phylogeny
PubMed: 35078581
DOI: 10.1016/j.funbio.2021.11.001 -
Journal of Applied Microbiology Oct 2022Tea (Camellia sinensis (L) O. Kuntze) is a long-duration monoculture crop prone to several biotic (fungal diseases and insect pest) and abiotic (nutrient deficiency,... (Review)
Review
Tea (Camellia sinensis (L) O. Kuntze) is a long-duration monoculture crop prone to several biotic (fungal diseases and insect pest) and abiotic (nutrient deficiency, drought and salinity) stress that eventually result in extensive annual crop loss. The specific climatic conditions and the perennial nature of the tea crop favour growth limiting abiotic factors, numerous plant pathogenic fungi (PPF) and insect pests. The review focuses on the susceptibility of tea crops to PPF/pests, drought, salinity and nutrient constraints and the potential role of beneficial actinobacteria in promoting tea crop health. The review also focuses on some of the major PPF associated with tea, such as Exobasidium vexans, Pestalotiopsis theae, Colletotrichum acutatum, and pests (Helopeltis theivora). The phylum actinobacteria own a remarkable place in agriculture due to the biosynthesis of bioactive metabolites that assist plant growth by direct nutrient assimilation, phytohormone production, and by indirect aid in plant defence against PPF and pests. The chemical diversity and bioactive significance of actinobacterial metabolites (antibiotics, siderophore, volatile organic compounds, phytohormones) are valuable in the agro-economy. This review explores the recent history of investigations in the role of actinobacteria and its secondary metabolites as a biocontrol agent and proposes a commercial application in tea cultivation.
Topics: Actinobacteria; Animals; Anti-Bacterial Agents; Bacteria; Camellia sinensis; Insecta; Plant Growth Regulators; Siderophores; Stress, Physiological; Tea; Volatile Organic Compounds
PubMed: 35880359
DOI: 10.1111/jam.15734 -
Persoonia Jun 2020Novel species of fungi described in this study include those from various countries as follows: , from marine sediment sand. , (incl. gen. nov.) from soil. , , , ,...
Novel species of fungi described in this study include those from various countries as follows: , from marine sediment sand. , (incl. gen. nov.) from soil. , , , , and from soil, from leaves of , on leaf litter of , and on soil, on , on soil, from leaves of , from leaves of , from leaves of , from soil associated with dying , from soil, on soil, on leaf litter, on leaf spots of . , on collar rot and stem of , on fallen branch of , from , from soil. , in soil. , from leaves of , and on leaf litter. , on leaf litter. , from indoor chestnut mill. , on soil, on dead needles of , on insects' frass. , from saline water. , from freshwater. , from , as endophyte from , from dates fruit, from swamp. , on soil. , , , and (incl. gen. nov.) from leaves of , from leaves of sp., from skin of human patient, from leaves of , and on leaf litter of , from soil, on soil, from leaves of , (incl. gen. nov.) from plant debris, in calcareus soil, in calcareus soil. , on corticated wood, from leaves of unknown , on branch lesions of , from heartwood of sp. , from leaves of , from air, (incl. gen. nov.) from leaves of , from a human skin sample, (incl. gen. nov.) on outside wall of alcohol distillery, from leaves of , (incl. gen. nov.) from leaves of , from air, from leaves of leaf spots of . , on branches of and on rotten wood. Morphological and culture characteristics are supported by DNA barcodes.
PubMed: 33116344
DOI: 10.3767/persoonia.2020.44.11 -
TheScientificWorldJournal 2022This study was conducted to isolate and identify the endophytic fungi from the bark and leaves of the plant and investigate the pharmacological activities of endophytic...
This study was conducted to isolate and identify the endophytic fungi from the bark and leaves of the plant and investigate the pharmacological activities of endophytic fungi along with plant parts. After isolation, endophytic fungi were identified based on morphological characteristics and molecular identification. Antimicrobial, antioxidant, and cytotoxic activities were studied by a disc diffusion method, free radical scavenging DPPH assay, and brine shrimp lethality bioassay, respectively. A total of eight endophytic fungi were isolated and identified up to the genus level based on morphological characteristics and confirmed by molecular identification techniques. Among the eight isolates, three isolates were identified as sp. (SCBE-2, SCBE-7, and SCLE-9), while the rest of the isolates belonged to sp. (SCBE-1), sp. (SCBE-3), sp. (SCBE-4), sp. (SCLE-7), and sp. (SCLE-8). The presence of flavonoids, anthraquinones, coumarins, and isocoumarins was assumed by the preliminary screening of the fungal and plant extracts by a thin-layer chromatographic technique under UV light. Fungal extracts of sp. sp. were found sensitive to all test bacteria, but only extracts from the leaf and bark showed significant antifungal activity along with their antimicrobial activity. sp. The fungal extract showed the highest free radical scavenging activity (2.43 g/mL) near that of ascorbic acid (2.42 g/mL). Some fungal extracts showed cytotoxic activity that, in general, suggests their probable abundance of biological metabolites. This is the first approach to investigate the endophytic fungi of Linn. in Bangladesh, to find the pharmacological potential of endophytes, and to explore novel compounds from those endophytes.
Topics: Syzygium; Fungi; Endophytes; Anti-Infective Agents; Free Radicals
PubMed: 36393829
DOI: 10.1155/2022/9529665 -
Natural Product Reports Sep 2018Covering: up to December 2017 The diversity of secondary metabolites in the fungal order Xylariales is reviewed with special emphasis on correlations between chemical... (Review)
Review
Covering: up to December 2017 The diversity of secondary metabolites in the fungal order Xylariales is reviewed with special emphasis on correlations between chemical diversity and biodiversity as inferred from recent taxonomic and phylogenetic studies. The Xylariales are arguably among the predominant fungal endophytes, which are the producer organisms of pharmaceutical lead compounds including the antimycotic sordarins and the antiparasitic nodulisporic acids, as well as the marketed drug, emodepside. Many Xylariales are "macromycetes", which form conspicuous fruiting bodies (stromata), and the metabolite profiles that are predominant in the stromata are often complementary to those encountered in corresponding mycelial cultures of a given species. Secondary metabolite profiles have recently been proven highly informative as additional parameters to support classical morphology and molecular phylogenetic approaches in order to reconstruct evolutionary relationships among these fungi. Even the recent taxonomic rearrangement of the Xylariales has been relying on such approaches, since certain groups of metabolites seem to have significance at the species, genus or family level, respectively, while others are only produced in certain taxa and their production is highly dependent on the culture conditions. The vast metabolic diversity that may be encountered in a single species or strain is illustrated based on examples like Daldinia eschscholtzii, Hypoxylon rickii, and Pestalotiopsis fici. In the future, it appears feasible to increase our knowledge of secondary metabolite diversity by embarking on certain genera that have so far been neglected, as well as by studying the volatile secondary metabolites more intensively. Methods of bioinformatics, phylogenomics and transcriptomics, which have been developed to study other fungi, are readily available for use in such scenarios.
Topics: Animals; Biodiversity; Biological Products; Endophytes; Genome, Fungal; Insecta; Molecular Structure; Phylogeny; Secondary Metabolism; Xylariales
PubMed: 29774351
DOI: 10.1039/c8np00010g -
PloS One 2021The eye is host to myriad bacterial, fungal, and viral organisms that likely influence ocular surface physiology in normal and diseased states. The ocular surface...
The eye is host to myriad bacterial, fungal, and viral organisms that likely influence ocular surface physiology in normal and diseased states. The ocular surface mycobiota of horses has not yet been described using NGS techniques. This study aimed to characterize the ocular surface fungal microbiota (mycobiota) in healthy horses in 2 environmental conditions (stalled versus pasture). Conjunctival swabs of both eyes were obtained from 7 adult stallions stabled in an open-air pavilion and 5 adult mares living on pasture. Genomic DNA was extracted from ocular surface swabs and sequenced using primers that target the Internal Transcribed Spacer 1 (ITS1) region of the fungal genome on an Illumina platform. Sequences were processed using Quantitative Insights Into Molecular Ecology (QIIME 2.0) and taxonomy assigned with the Findley et al. 2013 ITS1 database. The most abundant genera identified were Leptosphaerulina (22.7%), unclassified Pleosporaceae (17.3%), Cladosporium (16.2%), Alternaria (9.8%), unclassified Pleosporales (4.4%), unclassified Montagnulaceae (2.9%), Fusarium (2.5%), and Pestalotiopsis (1.4%). Fungal community composition (Jaccard, R = 0.460, p = 0.001) and structure (Bray-Curtis, R = 0.811, p = 0.001) were significantly different between pastured mares and stabled stallions. The ocular surface of pastured mares had significantly increased fungal species richness and diversity compared to stabled stallions (Shannon p = 0.0224, Chao1 p = 0.0118, Observed OTUs p = 0.0241). Relative abundances of Aspergillus (p = 0.005) and Alternaria spp. (p = 0.002) were significantly increased in the mycobiota of pastured mares. This is the first report to describe the mycobiota of the equine ocular surface. Environmental factors such as housing influence the composition, structure, and richness of the equine ocular surface mycobiota.
Topics: Alternaria; Animals; Aspergillus; Cladosporium; Eye; Female; Fusarium; Horses; Male; Pestalotiopsis
PubMed: 33539431
DOI: 10.1371/journal.pone.0246537 -
Journal of Fungi (Basel, Switzerland) Sep 2022Nonribosomal peptide synthetase (NRPS)-like enzymes containing A-T-R domain architecture are also known as carboxylate reductases (CARs) for aldehyde generation. To...
Nonribosomal peptide synthetase (NRPS)-like enzymes containing A-T-R domain architecture are also known as carboxylate reductases (CARs) for aldehyde generation. To identify new members of CARs, we established a virtual library containing 84 fungal CARs distributed in seven distinct clades by genome mining and phylogenetic analysis. Nine CARs, including PnlA from and eight known CARs, were clustered in clade VI and proposed to catalyze the reduction of nonreducing polyketide synthase (NR-PKS)-derived aryl carboxylic acids. The recombinant protein PnlA was overproduced and purified to apparent homogeneity from . In vitro enzyme assays of PnlA with 28 different benzoic acid derivatives (-) revealed the corresponding aldehyde formation in 14 cases (-). Comparison of conversion yields indicated the high preference of PnlA toward 3,5-dimethylorsellinic acid (DMOA, ) and vanillic acid (). A specificity-conferring code Q355 in PnlA was postulated by sequence alignment with the known CARs in clade VI. Our study provides an updated virtual library of fungal CAR enzymes and expands the biocatalytic selectivity of CARs.
PubMed: 36294566
DOI: 10.3390/jof8101001 -
Journal of Fungi (Basel, Switzerland) Nov 2022Pepper leaf spot is a common disease of . When it is serious, it directly affects the growth of , making the plant unable to blossom and bear fruit, which seriously...
Pepper leaf spot is a common disease of . When it is serious, it directly affects the growth of , making the plant unable to blossom and bear fruit, which seriously restricts the development of the industry. Therefore, the pathogenic mechanism of leaf spots should be explored to provide a basis for a comprehensive understanding of the disease. Using liquid chromatography-mass spectrometry (LC-MS) technology combined with the data-dependent acquisition, the full spectrum analysis of pathogen mycelium samples was carried out. Partial least squares discriminant analysis (PLS-DA) was used to reveal the differences in metabolic patterns among different groups. Hierarchical clustering analysis (HCA) and PLS-DA were used to reveal the relationship between samples and metabolites, which reflected the metabolomics changes of in the logarithmic growth phase of mycelia, the stable growth phase of mycelia, the massive spore stage, the induction culture conditions of PDA and leaves, and the possible pathogenic substances were selected for pathogenicity detection. PLS-DA had a strong predictive ability, indicating a clear analysis trend between different groups. The results of the metabolomics analysis showed that the differential metabolites of pathogenic bacteria were abundant at different stages and under different medium conditions, and the content of metabolites changed significantly. There were 3922 differential metabolites in nine groups under positive and negative ion modes, including lipids and lipid molecules, organic acids and their derivatives, organic heterocyclic compounds, organic oxygen compounds, carbohydrate polyketides, nucleosides, nucleotides, and analogs. The results of the pathogenicity test showed that the leaves treated with 3,5-dimethoxy benzoic acid, -(5-adenosy)-l-homocysteine, 2-(1-indol-3-yl) acetic acid, l-glutamic acid, and 2-(2-acetyl-3,5-dihydroxy phenyl) acetic acid showed different degrees of yellowish-brown lesions. This indicated that these substances may be related to the pathogenicity of , and the incidence was more serious when treated with 3,5-dimethoxybenzoic acid and -(5-adenosy)- l -homocysteine. This study provides a basis for further analysis of differential metabolites and provides a theoretical reference for the prevention and treatment of leaf spot.
PubMed: 36422029
DOI: 10.3390/jof8111208 -
Pathogens (Basel, Switzerland) Nov 2023The main pathogens affecting the carob () tree in the Mediterranean basin are described in this overview. The most widespread diseases periodically occurring in carob... (Review)
Review
The main pathogens affecting the carob () tree in the Mediterranean basin are described in this overview. The most widespread diseases periodically occurring in carob orchards are powdery mildew () and cercospora leaf spot (). The causal agents of "black leaf spots" (e.g., , and spp.) are responsible for symptoms similar to those previously mentioned for foliar diseases, but are reported in carob orchards at a negligible frequency. Likewise, canker and branch diebacks caused by fungal species belonging to Botryosphaeriaceae are almost never recorded. Among the rots of wood tissues that may compromise old carob specimens, "brown cubical rot" caused by is the most widespread and recurrent issue; this pathogen is also well-known for producing edible fruit bodies that are appreciated for pharmaceutical and industrial purposes. On the other hand, "white rots" caused by and species are less common and reported for the first time in this review. Gall-like protuberances on twigs of uncertain aetiology or tumors on branches associated with are described, although these symptoms are seldom detected, as they are also observed for necrotic leaf spots caused by pv. . A worldwide list of pathogens not yet recorded but at high risk of potential introduction in Italian carob-producing areas is also provided. Finally, concerns related to new phytopathogenic fungi vectored by the invasive ambrosia beetle are addressed. All the described pathogens could become limiting factors for carob production in the near future, because they could be favored by high-density orchards, the increasing global network of trade exchanges, and the high frequency at which extreme events related to climate change occur globally. Thus, symptoms and signs, causal agents, epidemiology, and, whenever applicable, recommendations for disease prevention and management are provided in this review.
PubMed: 38003821
DOI: 10.3390/pathogens12111357