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Molecules (Basel, Switzerland) Nov 2022In the current research, our work measured the effect of silver nanoparticles (AgNP) synthesized from Larrea tridentata (Sessé and Moc. ex DC.) on the mycelial growth...
In the current research, our work measured the effect of silver nanoparticles (AgNP) synthesized from Larrea tridentata (Sessé and Moc. ex DC.) on the mycelial growth and morphological changes in mycelia from different phytopathogenic and beneficial fungi. The assessment was conducted in Petri dishes, with Potato-Dextrose-Agar (PDA) as the culture medium; the AgNP concentrations used were 0, 60, 90, and 120 ppm. Alternaria solani and Botrytis cinerea showed the maximum growth inhibition at 60 ppm (70.76% and 51.75%). Likewise, Macrophomina spp. required 120 ppm of AgNP to achieve 65.43%, while Fusarium oxisporum was less susceptible, reaching an inhibition of 39.04% at the same concentration. The effect of silver nanoparticles was inconspicuous in Pestalotia spp., Colletotrichum gloesporoides, Phytophthora cinnamomi, Beauveria bassiana, Metarhizium anisopliae, and Trichoderma viridae fungi. The changes observed in the morphology of the fungi treated with nanoparticles were loss of definition, turgidity, and constriction sites that cause aggregations of mycelium, dispersion of spores, and reduced mycelium growth. AgNP could be a sustainable alternative to managing diseases caused by Alternaria solani and Macrophomina spp.
Topics: Silver; Metal Nanoparticles; Fungi; Alternaria; Fusarium; Ascomycota; Culture Media
PubMed: 36500239
DOI: 10.3390/molecules27238147 -
Molecules (Basel, Switzerland) Jun 2021This study investigated within-plant variability of the main bioactive compounds in rosemary ( L.). Volatile terpenes, including the enantiomeric distribution of...
This study investigated within-plant variability of the main bioactive compounds in rosemary ( L.). Volatile terpenes, including the enantiomeric distribution of monoterpenes, and phenols were analyzed in young and mature foliar, cortical and xylem tissues. In addition, antimicrobial activity of rosmarinic acid and selected terpenes was evaluated against two rosemary pathogens, and . Data showed that total concentration and relative contents of terpenes changed in relation to tissue source and age. Their highest total concentration was observed in the young leaves, followed by mature leaves, cortical and xylem tissues. Rosmarinic acid and carnosic acid contents did not show significant differences between leaf tissues of different ages, while young and mature samples showed variations in the content of four flavonoids. These results are useful for a more targeted harvesting of rosemary plants, in order to produce high-quality essential oils and phenolic extracts. Microbial tests showed that several terpenes and rosmarinic acid significantly inhibited the growth of typical rosemary pathogens. Overall, results on antimicrobial activity suggest the potential application of these natural compounds as biochemical markers in breeding programs aimed to select new chemotypes less susceptible to pathogen attacks, and as eco-friendly chemical alternatives to synthetic pesticides.
Topics: Alternaria; Anti-Infective Agents; Cinnamates; Depsides; Gas Chromatography-Mass Spectrometry; Microbial Sensitivity Tests; Microbial Viability; Oils, Volatile; Organ Specificity; Phenols; Pseudomonas; Rosmarinus; Terpenes; Rosmarinic Acid
PubMed: 34198771
DOI: 10.3390/molecules26113425 -
Journal of Applied Microbiology Dec 2015To identify the taxonomic differences between phytopathogenic small-spored Alternaria strains isolated from wheat kernels in Germany and Russia by a polyphasic approach.
AIMS
To identify the taxonomic differences between phytopathogenic small-spored Alternaria strains isolated from wheat kernels in Germany and Russia by a polyphasic approach.
METHODS AND RESULTS
Ninety-five Alternaria (A.) strains were characterized by their colony colour, their three-dimensional sporulation patterns, mycotoxin production and phylogenetic relationships based on sequence variation in translation elongation factor 1-α (TEF1-α). The examination of toxin profiles and the phylogenetic features via TEF1-α resulted in two distinct clusters, in each case containing Alternaria infectoria isolates (92 and 96% respectively) in the first and the Alternaria alternata, Alternaria arborescens and Alternaria tenuissima isolates (77 and 79% respectively) in the other combined cluster. The production of Alternariol, Altertoxin and Altenuene has not been reported previously in the A. infectoria species group. The isolates from Germany and Russia differ slightly in species composition and mycotoxin production capacity.
CONCLUSIONS
We identified that the A. infectoria species group can be differentiated from the A. alternata, A. arborescens and A. tenuissima species group by colour, low mycotoxin production and by the sequence variation in TEF1-α gene.
SIGNIFICANCE AND IMPACT OF THE STUDY
These results allow a reliable toxic risk assessment when detecting different Alternaria fungi on cereals.
Topics: Alternaria; Germany; Phenotype; Phylogeny; Russia; Spores, Fungal; Triticum
PubMed: 26381081
DOI: 10.1111/jam.12951 -
Journal of Microbiology and... Nov 2017Swainsonine (SW) is the principal toxic ingredient of locoweed plants that causes locoism characterized by a disorder of the nervous system. It has also received... (Review)
Review
Swainsonine (SW) is the principal toxic ingredient of locoweed plants that causes locoism characterized by a disorder of the nervous system. It has also received widespread attention in the medical field for its beneficial anticancer and antitumor activities. Endophytic fungi, sect. isolated from locoweeds, the plant pathogen , and the insect pathogen , produce swainsonine. Acquired SW by biofermentation has a certain foreground and research value. This paper mainly summarizes the local and foreign literature published thus far on the swainsonine biosynthesis pathway, and speculates on the possible regulatory enzymes involved in the synthesis pathway within these three fungi in order to provide a new reference for research on swainsonine biosynthesis by endophytic fungi.
Topics: Alternaria; Antineoplastic Agents; Ascomycota; Astragalus Plant; Biosynthetic Pathways; Endophytes; Fermentation; Metarhizium; Swainsonine
PubMed: 29092390
DOI: 10.4014/jmb.1709.09003 -
Sustainable production of camptothecin from an Alternaria sp. isolated from Nothapodytes nimmoniana.Scientific Reports Jan 2021Camptothecin the third most in demand alkaloid, is commercially extracted in India from the endangered plant, Nothapodytes nimmoniana. Endophytes, the microorganisms...
Camptothecin the third most in demand alkaloid, is commercially extracted in India from the endangered plant, Nothapodytes nimmoniana. Endophytes, the microorganisms that reside within plants, are reported to have the ability to produce host-plant associated metabolites. Hence, our research aims to establish a sustainable and high camptothecin yielding endophyte, as an alternative source for commercial production of camptothecin. A total of 132 endophytic fungal strains were isolated from different plant parts (leaf, petiole, stem and bark) of N. nimmoniana, out of which 94 were found to produce camptothecin in suspension culture. Alternaria alstroemeriae (NCIM1408) and Alternaria burnsii (NCIM1409) demonstrated camptothecin yields up to 426.7 ± 33.6 µg/g DW and 403.3 ± 41.6 µg/g DW, respectively, the highest reported production to date. Unlike the reported product yield attenuation in endophytes with subculture in axenic state, Alternaria burnsii NCIM1409 could retain and sustain the production of camptothecin up to ~ 200 μg/g even after 12 continuous subculture cycles. The camptothecin biosynthesis in Alternaria burnsii NCIM1409 was confirmed using C carbon labelling (and cytotoxicity analysis on different cancer cell lines) and this strain can now be used to develop a sustainable bioprocess for in vitro production of camptothecin as an alternative to plant extraction.
Topics: Alkaloids; Alternaria; Camptothecin; Endophytes; India; Magnoliopsida; Plant Leaves
PubMed: 33446714
DOI: 10.1038/s41598-020-79239-5 -
Toxins May 2024Herbal medicines are widely used for clinical purposes worldwide. These herbs are susceptible to phytopathogenic fungal invasion during the culturing, harvesting,...
Herbal medicines are widely used for clinical purposes worldwide. These herbs are susceptible to phytopathogenic fungal invasion during the culturing, harvesting, storage, and processing stages. The threat of fungal and mycotoxin contamination requires the evaluation of the health risks associated with these herbal medicines. In this study, we collected 138 samples of 23 commonly used herbs from 20 regions in China, from which we isolated a total of 200 phytopathogenic fungi. Through morphological observation and ITS sequencing, 173 fungal isolates were identified and classified into 24 genera, of which the predominant genera were (27.74%) and (20.81%), followed by (11.56%), (7.51%), and (6.84%). Quantitative analysis of the abundance of both and in herbal medicines via RT-qPCR revealed that the most abundant fungi were found on the herb , reaching 300,000 copies/μL for and 700 copies/μL for . The in vitro mycotoxin productivities of the isolated and strains were evaluated by using liquid chromatography-tandem mass spectrometry (LC-MS/MS), and it was found that the species mainly produced the acetyl forms of deoxynivalenol, while species mainly produced altertoxins. These findings revealed widely distributed fungal contamination in herbal medicines and thus raise concerns for the sake of the quality and safety of herbal medicines.
Topics: China; Drug Contamination; Fungi; Mycotoxins; Plants, Medicinal; Fusarium; Drugs, Chinese Herbal; Alternaria; Tandem Mass Spectrometry
PubMed: 38787081
DOI: 10.3390/toxins16050229 -
Genes May 2023Alternaria black spot disease on pecan is caused by the opportunistic pathogen and poses a serious threat to the local South African and global pecan industry. Several...
Alternaria black spot disease on pecan is caused by the opportunistic pathogen and poses a serious threat to the local South African and global pecan industry. Several diagnostic molecular marker applications have been established and used in the screening of various fungal diseases worldwide. The present study investigated the potential for polymorphism within samples of isolates obtained from eight different geographical locations in South Africa. Pecan () leaves, shoots, and nuts-in-shuck with Alternaria black spot disease were sampled, and 222 isolates were retrieved. For rapid screening to identify Alternaria black spot pathogens, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the Alternaria major allergen () gene region was used, followed by the digestion of the amplicons with III and I endonucleases. The assay resulted in five (III) and two (I) band patterns. Unique banding patterns from the two endonucleases showed the best profile and isolates were grouped into six clusters using a UPGMA (unweighted pair group method with arithmetic averages) distance matrix (Euclidean) dendrogram method on R-Studio. The analysis confirmed that the genetic diversity of does not depend on host tissues or the pecan cultivation region. The grouping of selected isolates was confirmed by DNA sequence analysis. The phylogeny corroborated no speciation within the dendrogram groups and showed 98-100% bootstrap similarity. This study reports the first documented rapid and reliable technique for routine screening identification of pathogens causing Alternaria black spot in South Africa.
Topics: Alternaria; Carya; Polymorphism, Restriction Fragment Length; Haplotypes; Polymerase Chain Reaction
PubMed: 37239475
DOI: 10.3390/genes14051115 -
Toxins Jun 2023Alternariol is a metabolite produced by fungus that can contaminate a variety of food and feed materials. The objective of the present paper was to provide a prediction...
Alternariol is a metabolite produced by fungus that can contaminate a variety of food and feed materials. The objective of the present paper was to provide a prediction of Phase I and II metabolites of alternariol and a detailed ADME/Tox profile for alternariol and its metabolites using an in silico working model based on the MetaTox, SwissADME, pKCMS, and PASS online computational programs. A number of 12 metabolites were identified as corresponding to the metabolomic profile of alternariol. ADME profile for AOH and predicted metabolites indicated a moderate or high intestinal absorption probability but a low probability to penetrate the blood-brain barrier. In addition to cytotoxic, mutagenic, carcinogenic, and endocrine disruptor effects, the computational model has predicted other toxicological endpoints for the analyzed compounds, such as vascular toxicity, haemato-toxicity, diarrhea, and nephrotoxicity. AOH and its metabolites have been predicted to act as a substrate for different isoforms of phase I and II drug-metabolizing enzymes and to interact with the response to oxidative stress. In conclusion, in silico methods can represent a viable alternative to in vitro and in vivo tests for the prediction of mycotoxins metabolism and toxicity.
Topics: Lactones; Oxidative Stress; Metabolomics; Alternaria; Mycotoxins
PubMed: 37505690
DOI: 10.3390/toxins15070421 -
Applied Microbiology and Biotechnology Dec 2024Transcription factor Cmr1 (Colletotrichum melanin regulation 1) and its homologs in several plant fungal pathogens are the regulators of the 1,8-dihydroxynaphthalene...
Transcription factor Cmr1 (Colletotrichum melanin regulation 1) and its homologs in several plant fungal pathogens are the regulators of the 1,8-dihydroxynaphthalene (DHN)-melanin biosynthesis pathway and have evolved functional diversification in morphology and pathogenicity. The fungal genus Alternaria comprises the group of "black fungi" that are rich in DHN-melanin in the primary cell wall and septa of the conidia. Some Alternaria species cause many economically important plant diseases worldwide. However, the evolution and function of Cmr1 homologs in Alternaria remain poorly understood. Here, we identified a total of forty-two Cmr1 homologs from forty-two Alternaria spp. and all contained one additional diverse fungal specific transcription factor motif. Phylogenetic analysis indicated the division of these homologs into five major clades and three branches. Dated phylogeny showed the A and D clades diverged latest and earliest, respectively. Molecular evolutionary analyses revealed that three amino acid sites of Cmr1 homologs in Alternaria were the targets of positive selection. Asmr1, the homolog of Cmr1 in the potato early blight pathogen, Alternaria solani was amplified and displayed the sequence conservation at the amino acid level in different A. solani isolates. Asmr1 was further confirmed to have the transcriptional activation activity and was upregulated during the early stage of potato infection. Deletion of asmr1 led to the decreased melanin content and pathogenicity, deformed conidial morphology, and responses to cell wall and fungicide stresses in A. solani. These results suggest positive selection and functional divergence have played a role in the evolution of Cmr1 homologs in Alternaria. KEY POINTS: • Cmr1 homologs were under positive selection in Alternaria species • Asmr1 is a functional transcription factor, involved in spore development, melanin biosynthesis, pathogenicity, and responses to cell wall and fungicide stresses in A. solani • Cmr1 might be used as a potential taxonomic marker of the genus Alternaria.
Topics: Transcription Factors; Alternaria; Melanins; Fungicides, Industrial; Phylogeny; Naphthols
PubMed: 38229332
DOI: 10.1007/s00253-023-12893-7 -
Microbiology Spectrum Jun 2024is a ubiquitous soil-borne fungus capable of causing diseases in a variety of plants and occasionally in humans. While populations of from infected plants have...
UNLABELLED
is a ubiquitous soil-borne fungus capable of causing diseases in a variety of plants and occasionally in humans. While populations of from infected plants have received significant attention, relatively little is known about its soil populations, including its population genetic structure and antifungal susceptibilities. In addition, over the last two decades, greenhouses have become increasingly important for food and ornamental plant production throughout the world, but how greenhouses might impact microbial pathogens such as populations remains largely unknown. Different from open crop fields, greenhouses are often more intensively cultivated, with each greenhouse being a relatively small and isolated space where temperature and humidity are higher than surrounding environments. Previous studies have shown that greenhouse populations of two common molds, and within a small community in southwestern China were variably differentiated. However, the relative contribution of physical separation among local greenhouses to the large-scale population structure remains unknown. Here, we isolated strains of from seven greenhouses in Shijiazhuang, northeast China. Their genetic diversity and triazole susceptibilities were analyzed and compared with each other and with 242 isolates from nine greenhouses in Kunming, southwest China. Results showed that the isolation of greenhouses located <1 km from each other locally contributed similarly to the overall genetic variation as that between the two distant geographic regions. In addition, our results indicate that greenhouses could be significant sources of triazole resistance, with greenhouses often differing in their frequencies of resistant strains to different triazoles.
IMPORTANCE
Greenhouses have become increasingly important for food production and food security. However, our understanding of how greenhouses may contribute to genetic variations in soil microbial populations is very limited. In this study, we obtained and analyzed soil populations of the cosmopolitan fungal pathogen in seven greenhouses in Shijiazhuang, northeast China. Our analyses revealed high proportions of isolates being resistant to agricultural triazole fungicides and medical triazole drugs, including cross-resistance to both groups of triazoles. In addition, we found that greenhouse populations of located within a few kilometers showed similar levels of genetic differentiation as those separated by over 2,000 km between northeast and southwest China. Our study suggests that greenhouse populations of this and potentially other fungal pathogens represent an important ecological niche and an emerging threat to food security and human health.
Topics: Alternaria; China; Soil Microbiology; Plant Diseases; Genetic Variation; Antifungal Agents; Phylogeny; Drug Resistance, Fungal; Triazoles
PubMed: 38727239
DOI: 10.1128/spectrum.00390-24