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Plant Disease May 2023Alternaria rot, caused by and , is one of the common postharvest diseases affecting mandarin fruit in California. Fungicide resistance profilings of and to quinone...
Alternaria rot, caused by and , is one of the common postharvest diseases affecting mandarin fruit in California. Fungicide resistance profilings of and to quinone outside inhibitors (QoIs), fludioxonil, pyrimethanil, imazalil, and propiconazole were examined in this study. Of the 100 isolates of and , 40 were identified as resistant to QoI fungicides according to a PCR-restriction fragment length polymorphism based on a partial gene. Effective concentrations of fludioxonil that caused a 50% reduction in fungal growth relative to the control (EC) were 0.089 ± 0.020 and 0.101 ± 0.032 µg/ml for 43 and 19 isolates, respectively. EC values of pyrimethanil, imazalil, and propiconazole for the 70 isolates tested were 0.373 ± 0.161, 0.492 ± 0.133, and 1.135 ± 0.407 µg/ml, respectively. EC values of pyrimethanil, imazalil, and propiconazole for 30 isolates were 0.428 ± 0.190, 0.327 ± 0.180, and 0.669 ± 0.452 µg/ml, respectively. Control tests on mandarin fruit inoculated with representative isolates of both species showed that fludioxonil, pyrimethanil, imazalil and propiconazole significantly reduced disease incidence and severity. Azoxystrobin significantly reduced Alternaria rot severity and incidence on mandarin fruit inoculated with sensitive isolates but not with resistant isolates, regardless of spp. There were no significant differences in Alternaria rot control effectiveness if treatment with any of the fungicides tested was delayed after inoculation by 6 or 12 h. These results could help in the development of postharvest fungicide programs to control Alternaria rot on mandarin fruit during storage.
Topics: Fungicides, Industrial; Fruit; Alternaria
PubMed: 36336668
DOI: 10.1094/PDIS-09-22-2157-RE -
Mycotoxin Research May 2022Fungi and mycotoxins in silage can have detrimental consequences for both cattle and human health. This pilot study identified, via the routinary direct plating method,...
Fungi and mycotoxins in silage can have detrimental consequences for both cattle and human health. This pilot study identified, via the routinary direct plating method, the dominant cultivable fungi in mouldy grass silages (GS) (n = 19) and maize silages (MS) (n = 28) from Austria. The profiles of regulated, modified, and emerging mycotoxins together with other fungal metabolites were analysed via LC-(ESI)MS/MS. Penicillium roqueforti, Saccharomyces spp., Geotrichum candidum, Aspergillus fumigatus and Monascus ruber were the most frequent fungal organisms identified. Other species including Mucor circinelloides, Fusarium spp. and Paecilomyces niveus were detected at lower frequencies. The presence of complex mixtures of toxic and potentially toxic compounds was evidenced by high levels and occurrences (≥ 50%) of Penicillium-produced compounds such as mycophenolic acid (MPA), roquefortines (ROCs), andrastins (ANDs) and marcfortine A. Mouldy silages contained toxins commonly produced by genus Fusarium (e.g. zearalenone (ZEN) and trichothecenes), Alternaria (like tenuazonic acid (TeA) and alternariol (AHO)) and Aspergillus (such as sterigmatocystin (STC)). Compared to those in GS, mouldy spots in MS presented significantly higher fungal counts and more diverse toxin profiles, in addition to superior levels of Fusarium spp., Penicillium spp. and total fungal metabolites. Generally, no correlation between mould counts and corresponding metabolites was detected, except for the counts of P. roqueforti, which were positively correlated with Penicillium spp. metabolites in mouldy MS. This study represents a first assessment of the fungal diversity in mouldy silage in Austria and highlights its potential role as a substantial contributor to contamination with complex mycotoxin mixtures in cattle diets.
Topics: Alternaria; Animals; Austria; Cattle; Food Contamination; Fusarium; Mycotoxins; Pilot Projects; Poaceae; Silage; Tandem Mass Spectrometry; Zea mays
PubMed: 35347677
DOI: 10.1007/s12550-022-00453-3 -
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 -
BMC Complementary Medicine and Therapies Sep 2023The emergence of multidrug-resistant pathogens and the lack of new antimicrobial drugs is a major public health concern that needs urgent and innovative solutions....
Endophytic fungal species Nigrospora oryzae and Alternaria alternata exhibit antimicrobial activity against gram-positive and gram-negative multi-drug resistant clinical bacterial isolates.
BACKGROUND
The emergence of multidrug-resistant pathogens and the lack of new antimicrobial drugs is a major public health concern that needs urgent and innovative solutions. Endophytic fungi living in unique niches such as in endosymbiosis with plants are increasingly drawing attention as alternative sources of novel and chemically diverse compounds with unique mechanisms of action.
METHODS
In the present study, ten endophytic fungi isolated from the medicinal plant, Sclerocarya birrea were screened for bioactivity against a panel of indicator bacteria. Three bioactive endophytic fungi (strains P02PL2, P02MS1, and P02MS2A) were selected and identified through ITS-rDNA sequencing. The whole broth extracts of the three selected isolates were further screened against contemporary drug-resistant bacterial pathogens. This was followed by partial purification by solid phase extraction and GC-MS analysis of bioactive fractions.
RESULTS
The bioactive endophytic fungi were identified as Alternaria alternata species (strains P02PL2 and P02MS1) and Nigrospora oryzae (strain P02MS2A). The whole broth extracts from N. oryzae P02MS2A exhibited a MIC of one μg/mL and 16 μg/mL against gram-negative, MDR Pseudomonas 5625574 and gram-positive MRSA 25775 clinical isolates, respectively. After partial purification and GC-MS analysis of whole broth extract from A. alternaria PO2MS1, 2-fluorobenzoic acid heptadecyl was putatively identified as the active compound in fraction C of this extract. This compound was also putatively identified in fraction E of A. alternata P02PL2, fraction B of A. alternata P02MS1 and fraction B of N. oryzae P02MS2A, and interestingly, all these fractions retained activity against the two MDR clinical isolates.
CONCLUSION
The putative identification of 2-fluorobenzoic acid heptadecyl compound showing a broad-spectrum of activity, more especially against gram-negative MDR contemporary pathogens is highly encouraging in the initiative at developing novel drugs to combat multi-drug resistance.
Topics: Alternaria; Plant Extracts
PubMed: 37715184
DOI: 10.1186/s12906-023-04157-8 -
Molecules (Basel, Switzerland) Jan 2021Based on the structure of the natural product cysteine, a series of thiazolidine-4-carboxylic acids were designed and synthesized. All target compounds bearing...
Based on the structure of the natural product cysteine, a series of thiazolidine-4-carboxylic acids were designed and synthesized. All target compounds bearing thiazolidine-4-carboxylic acid were characterized by H-NMR, C-NMR, and HRMS techniques. The antiviral and antifungal activities of cysteine and its derivatives were evaluated in vitro and in vivo. The results of anti-TMV activity revealed that all compounds exhibited moderate to excellent activities against tobacco mosaic virus (TMV) at the concentration of 500 μg/mL. The compounds cysteine (), -, , , , , , and displayed higher anti-TMV activities than the commercial plant virucide ribavirin (inhibitory rate: 40, 40, and 38% at 500 μg/mL for inactivation, curative, and protection activity in vivo, respectively), especially compound (inhibitory rate: 51%, 47%, and 49% at 500 μg/mL for inactivation, curative, and protection activity in vivo, respectively) with excellent antiviral activity emerged as a new antiviral candidate. Antiviral mechanism research by TEM exhibited that compound could inhibit virus assembly by aggregated the 20S protein disk. Molecular docking results revealed that compound with higher antiviral activities than that of compound did show stronger interaction with TMV CP. Further fungicidal activity tests against 14 kinds of phytopathogenic fungi revealed that these cysteine derivatives displayed broad-spectrum fungicidal activities. Compound exhibited higher antifungal activities against and than commercial fungicides carbendazim and chlorothalonil, which emerged as a new candidate for fungicidal research.
Topics: Alternaria; Antifungal Agents; Antiviral Agents; Ascomycota; Cysteine; Drug Discovery; Microbial Sensitivity Tests; Molecular Structure; Tobacco Mosaic Virus
PubMed: 33450940
DOI: 10.3390/molecules26020383 -
Critical Reviews in Food Science and... 2022Potato ( L.), a worldwide, staple food crop, is susceptible to postharvest rots caused by a variety of fungal pathogens, including spp., spp., , , and . Rots... (Review)
Review
Potato ( L.), a worldwide, staple food crop, is susceptible to postharvest rots caused by a variety of fungal pathogens, including spp., spp., , , and . Rots resulting from infections by these pathogens cause a significant reduction in potato quality and marketable yield. Importantly, some of these decay fungi also produce mycotoxins that represent a potential risk to human health. In the present review, an overview and discussion are provided on the epidemiology and pathogenesis of decay fungi, especially spp., that include recent data derived from genomic and phylogenetic analyses. The biosynthesis and functional role of fungitoxic metabolites such as trichothecene mycotoxins and fusaric acid, produced in rotted potatoes are also reviewed. Advances in pre- and postharvest measures for rot management, especially eco-friendly methods including physical control, biological control, the use of natural compounds, and other agricultural management practices are also reviewed. Lastly, novel approaches to control potato dry rot such as the use of mycoviruses and CRISPR technology are highlighted.
Topics: Alternaria; Fusarium; Humans; Phylogeny; Plant Diseases; Solanum tuberosum
PubMed: 32924541
DOI: 10.1080/10408398.2020.1818688 -
TheScientificWorldJournal 2021Crude oil spills as a result of natural disasters or extraction and transportation operations are common nowadays. Oil spills have adverse effects on both aquatic and...
Crude oil spills as a result of natural disasters or extraction and transportation operations are common nowadays. Oil spills have adverse effects on both aquatic and terrestrial ecosystems and pose a threat to human health. This study have been concerned with studying the capability of six fungal species (, , , , , and ) and three fungal consortia (FC), FC1 ( and ), FC2 ( and ), and FC3 (, and ), to remediate petroleum hydrocarbons (PHs). Qualitative and quantitative changes in polyaromatic hydrocarbons (PAHs) and saturated hydrocarbons (SH) mixtures and the patterns of PHs degradation have been examined using HPLC and GC. Studying the GC chromatogram of revealed severe degradation of SHs exhibited by this species, and the normal-paraffin and isoparaffin degradation percentage have been valued 97.19% and 98.88%, respectively. has shown the highest significant (at ˂ 0.05) PAH degradation percent reaching 72.07%; followed by 59.51%. HPLC data have revealed that high-molecular-weight PAH percent/total PAHs decreased significantly from 98.94% in control samples to 68.78% in samples treated with . FC1 and FC2 consortia have exhibited the highest significant PH deterioration abilities than did the individual isolates, indicating that these fungal consortia exhibited positive synergistic effects. The study supports the critical idea of the potential PAH and SH biodegradation as a more ecologically acceptable alternative to their chemical degradation.
Topics: Alternaria; Ascomycota; Biodegradation, Environmental; Chromatography, Gas; Chromatography, High Pressure Liquid; Cladosporium; Curvularia; Hydrocarbons; Penicillium chrysogenum; Petroleum; Petroleum Pollution; Polycyclic Aromatic Hydrocarbons; Scopulariopsis
PubMed: 34054359
DOI: 10.1155/2021/6641533 -
Journal of Applied Microbiology Oct 2021This study sought to utilize indigenous soil micro-organisms to suppress wilt-causing fungal pathogens of the banana.
AIMS
This study sought to utilize indigenous soil micro-organisms to suppress wilt-causing fungal pathogens of the banana.
METHODS AND RESULTS
Fungal pathogens were isolated from wilt-affected rhizospheric soil, and potential antagonistic bacterial strains were isolated from healthy rhizospheric soil in the same area from which fungal pathogens were isolated. The antifungal activity of isolated micro-organisms against fungal pathogens was studied both in vitro and in vivo against fungal pathogens. It was found that Fusarium oxysporum and Alternaria sp. were pathogenic, while Penicillium sp., Bacillus velezensis and Bacillus subtilis were antagonistic. Moreover, it was seen that B. velezensis, B. subtilis and Penicillium sp. inhibited the growth of the two fungal pathogens in both in vitro and in vivo experiments. Further investigation indicated that B. velezensis, B. subtilis and Penicillium sp. were able to produce enzymatic antifungal compounds (chitinase and β-1,3-glucanase). The spray application around rhizome revealed that a combination of Bacillus spp. and Penicillium sp. in greenhouse conditions gave the highest reduction in disease severity by up to 60% to both fungal pathogens among the treatments.
CONCLUSIONS
Banana disease is seen to be induced not only by F. oxysporum but also by Alternaria sp. The isolated indigenous micro-organisms can effectively control both the pathogens. The combination of isolated antagonistic micro-organisms has thus demonstrated substantial potential for suppressing banana disease.
SIGNIFICANCE AND IMPACT OF THE STUDY
An antagonistic consortium isolated in this study has demonstrated remarkable potential for controlling fungal diseases caused by Fusarium sp. and Alternaria sp. Therefore, the use of indigenous microflora to improve disease suppression of banana plants against soil-borne pathogens is a preferable approach.
Topics: Alternaria; Bacillus; Biological Control Agents; Fusarium; Musa; Penicillium; Plant Diseases
PubMed: 33694313
DOI: 10.1111/jam.15067 -
Chemical Research in Toxicology May 2022After ingestion of food commodities, the gastrointestinal tract (GIT) poses the first barrier against xenobiotics and pathogens. Therefore, it is regularly confronted...
After ingestion of food commodities, the gastrointestinal tract (GIT) poses the first barrier against xenobiotics and pathogens. Therefore, it is regularly confronted with external stressors potentially affecting the inflammatory response and the epithelial barrier. mycotoxins such as alternariol (AOH) and altertoxin II (ATX-II) are frequently occurring food and feed contaminants that are described for their immunomodulatory capacities. Hence, this study aimed at exploring the effect of AOH and ATX-II as single compounds or binary mixtures on the immune response and epithelial homeostasis in noncancerous colon epithelial cells HCEC-1CT. Both toxins suppressed mRNA levels of proinflammatory mediators interleukin-8 (IL-8), tumor necrosis factor α (TNF-α), and secretion of IL-8, as well as mRNA levels of the matrix metallopeptidase 2 (MMP-2). Binary combinations of AOH and ATX-II reduced the response of the single toxins. Additionally, AOH and ATX-II modified immunolocalization of transmembrane proteins such as integrin β1, zona occludens 1 (ZO-1), claudin 4 (Cldn 4), and occludin (Ocln), which support colonic tissue homeostasis and intestinal barrier function. Moreover, the cellular distribution of ZO-1 was affected by ATX-II. Mechanistically, these effects could be traced back to the involvement of several transcription factors. AOH activated the nuclear translocation of the aryl hydrocarbon receptor (AhR) and the nuclear factor erythroid 2-related factor 2 (Nrf2), governing cell metabolic competence and structural integrity. This was accompanied by altered distribution of the NF-κB p65 protein, an important regulator of inflammatory response. ATX-II also induced AhR and Nrf2 translocation, albeit failing to substantiate the effect of AOH on the colonic epithelium. Hence, both toxins coherently repress the intestinal immune response on the cytokine transcriptional and protein levels. Furthermore, both mycotoxins affected the colonic epithelial integrity by altering the cell architecture.
Topics: Alternaria; Colon; Epithelial Cells; Immunity; Interleukin-8; Lactones; Mycotoxins; NF-E2-Related Factor 2; RNA, Messenger; Receptors, Aryl Hydrocarbon
PubMed: 35405071
DOI: 10.1021/acs.chemrestox.1c00364 -
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