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Persoonia Dec 2022Novel species of fungi described in this study include those from various countries as follows: , on leaves, stems and fruits of . , on soil, on dying leaf of from...
Novel species of fungi described in this study include those from various countries as follows: , on leaves, stems and fruits of . , on soil, on dying leaf of from yellowing leaf tips of on well-rotted wood, from necrotic leaf of , from the body of a dead spider, from leaf spots of from gills of and from leaf spots of . , from air. , from the rhizosphere of subsp. f. . , on soil in mixed forest with and . , on dead culm of unidentified . , from symptomless stem wood of . , on infected fruit of on leaves of , and on basal trunk of . , from kernels. , and on stems of , and on symptomatic leaves of . , on stems of (incl. gen. nov.) and from dead culms of . , on soil in a forest. , from rhizosphere soil of , and on leaf spots of . , on dead wood or bark. , on leaves of and on bark of . , on decaying wood of subsp. , from fluvial sediments, endophytic in roots of , and from calcareus soils. , on stumps and woody debris. , from soil under . , on soil under and on soil under trees. , on dead twigs of . , (incl. gen. nov.) from office air. Morphological and culture characteristics are supported by DNA barcodes. Tan YP, Bishop-Hurley SL, Shivas RG, et al. 2022. Fungal Planet description sheets: 1436-1477. Persoonia 49: 261-350. https://doi.org/10.3767/persoonia.2022.49.08.
PubMed: 38234383
DOI: 10.3767/persoonia.2022.49.08 -
Plant Disease Dec 2022In June 2021, a previously unreported leaf blight disease of peanut (Arachis hypogaea) was observed on field-grown peanut (Jinhua19) in Laixi city, Shandong province of...
In June 2021, a previously unreported leaf blight disease of peanut (Arachis hypogaea) was observed on field-grown peanut (Jinhua19) in Laixi city, Shandong province of China. Approximately 5% of plants showed disease symptoms in the fields we investigated. The symptoms first appeared as yellow round or irregular spots on leaves, and then the spots became brown. As the disease progressed, spots became larger and even converge, which later produced leaf chlorosis and abscission. Symptomatic leaves were cut into small pieces, surface disinfested with 70% ethanol for 30s, 1% NaClO for 60s, rinsed three times in sterile water, dried on sterile filter papers, placed on potato dextrose agar (PDA) media, and incubated at 25°C in darkness. Fungal cultures were initially white, with red pigment, then turned gray, and eventually turned black, and aerial hyphae were dense. Conidia were spherical or slightly ellipsoidal, black, smooth, and 8.6 to 11.5 × 8.7 to 14.5μm (n=50). Morphological characteristics of the isolates matched the description of Nigrospora aurantiaca (Wang et al. 2017). Molecular identification was performed by sequencing beta tubulin gene (TUB) with Bt2a/Bt2b and translation elongation factor 1-alpha (TEF) with EF1-728F/EF1-986R (Wang et al. 2021) of a representative isolate ZHX11. TUB (OK489789) and TEF (OK489790) of ZHX11 obtained 100% (401/401 nucleotides) and 99.64% (279/279 nucleotides) similar to those of N. aurantiaca (MN329935, MN264010), respectively. Alignment was conducted separately for each gene set using Clustal W algorithm implemented in MEGA 7.0 (Kumar et al. 2016), and multi-gene (TUB and TEF) phylogenetic analyses using Neighbor-Joining (NJ) method showed that the isolate was N. aurantiaca. To complete Koch's postulates, nine 2-week-old peanut (Zhonghua 12) seedlings were sprayed with conidia suspensions (106 conidia mL-1 in 0.05% Tween 20 buffer). The same number of seedlings were only treated with 0.05% Tween buffer as controls. The experiment was repeated three times. Plants were incubated in a growth chamber (30°C in the day and 25°C at night, a 12-h photoperiod and 80% RH). Ten days after inoculation, typical symptoms were observed on inoculated leaves but not on the controls. N. aurantiaca was reisolated from the diseased leaves but not from the controls. N. sphaerica was observed on peanut in China (Liu et al. 2020). To our knowledge, this is the first report of N. aurantiaca causing leaf blight on peanut in shandong province, China. These findings will help to develop better preventive measures in accordance with the emergence of the new disease.
PubMed: 36471468
DOI: 10.1094/PDIS-05-22-1134-PDN -
Botanical Studies Oct 2021Many groups of fungi live as an endophyte in plants. Both published and undiscovered bioactive compounds can be found in endophytic fungi. Various biological activities...
BACKGROUND
Many groups of fungi live as an endophyte in plants. Both published and undiscovered bioactive compounds can be found in endophytic fungi. Various biological activities of bioactive compounds from endophytic fungi had been reported, including anti-inflammatory and anticancerous effects. The chemical investigation of biologically active compounds from endophytic fungi Melaleuca leucadendra Linn. have not yet been stated.
RESULTS
One new compound, namely nigaurdiol (1), along with five known compounds, xyloketal K (2), bostrycin (3), deoxybostrycin (4), xylanthraquinone (5), and ergosterol (6), were isolated from the Melaleuca leucadendra Linn. associated fungal strain Nigrospora aurantiaca TMU062. Their chemical structures were elucidated by spectroscopic data and compared with literature. All isolated compounds were evaluated for inhibitory effect of NO production in LPS-activated microglial BV-2 cells.
CONCLUSIONS
Compound 6 exhibited considerable inhibitory effect on NO production with IC values of 7.2 ± 1.4 µM and the survival rate of the cells was 90.8 ± 6.7% at the concentration of 10 µM.
PubMed: 34698886
DOI: 10.1186/s40529-021-00324-7 -
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 -
Plant Disease Aug 2021Asiatic dayflower ( L.) is an annual herbaceous weed that is distributed throughout China. A foliar disease on Asiatic dayflowers was discovered in one farm field in...
Asiatic dayflower ( L.) is an annual herbaceous weed that is distributed throughout China. A foliar disease on Asiatic dayflowers was discovered in one farm field in Dianjiang County, Chongqing, China (N30°3´22″, E107°18´5″) in summer, 2019. The disease incidence was observed on about 10% (13/127) of the plants. Symptoms appeared as round-shaped tan lesions (2-5 mm) in diameter that occurred randomly and irregularly on the whole leaves. The centers of lesions become grayish white with reddish borders as the disease progressed. The leaves with typical symptoms were detached and wiped with 70% ethanol for surface disinfestation before isolating the causal agent. Subsequently, three pieces (3-4 mm) of tissue were taken from the margin of the leaf lesion, disinfested in 1.5% NaClO for 1 min, rinsed 3 times in sterilized distilled water, and placed onto Potato Dextrose Agar (PDA) medium containing 50 μg/ml each of kanamycin and ampicillin. A fungus was exclusively and consistently isolated from the disinfested leaf lesion sections. The colonies on PDA grew rapidly and covered the entire petri dish within 5 days at 28℃. Colonies were at first grayish white, cotton wool-like, round, with abundant aerial mycelium, and later turned black as conidia produced. The abundant conidia formed on PDA were initially yellow brown and gradually became black, oblate to ellipsoidal, smooth, single-celled, and ranged in size from 4 to 10 × 3.5 to 9 μm. They were borne on a colorless, hyaline, and inverted flask-shaped cell at the tip of each conidiophore. The morphology characteristics were consistent with those of spp. (Wang et al. 2017). Genomic DNA was extracted from one representative isolate NDJ0819. The amplification and sequencing of the gene fragments including the internal transcribed space (ITS) region of ribosomal DNA and beta-tubulin were performed using the primers ITS1/ITS4 (White et al. 1990) and Bt2a/Bt2b (Glass and Donaldson 1995), respectively. Fragments of 536 bp for ITS and 408 bp for beta-tubulin were obtained. A phylogram of the combined ITS and beta-tubulin sequences reconstructed using the maximum likelihood bootstrapping method implemented in the software MEGA version 7.0 (Kumar et al. 2016) indicated that isolate NDJ0819 clustered with . Both ITS and beta-tubulin sequences were deposited into GenBank (accession no. MT140353 and MT157509, respectively). Pathogenicity test was performed by rub-inoculating needle-wounded leaves of three 4-week-old Asiatic dayflowers with spore suspension (2.6 × 10 conidia/ml) of NDJ0819 prepared in water containing 0.05% Tween-20, and holding plants at 28℃ in the growth chamber. The pathogenicity test was repeated twice. Brown, round-shaped lesions developed on leaves inoculated with spores at 15 days post-inoculation. However, the centers of the lesion did not become grayish white, compared to those of lesions seen in naturally infected leaves. No symptoms developed on leaves inoculated with sterilized distilled water. was re-isolated from the lesions. All results described above indicated that was responsible for the leaf spot of Asiatic dayflower. To our knowledge, this is the first report of causing leaf spot on Asiatic dayflower in China. Research into the potential use of as a candidate biological agent against the weed is worth being initiated.
PubMed: 34463526
DOI: 10.1094/PDIS-06-21-1271-PDN -
Frontiers in Microbiology 2022Endophytic fungi are microorganisms with the ability to colonize plants for the entire or at least a significant part of their life cycle asymptomatically, establishing...
Endophytic fungi are microorganisms with the ability to colonize plants for the entire or at least a significant part of their life cycle asymptomatically, establishing a plant-fungus association. They play an important role in balancing ecosystems, as well as benefiting host through increasing plant growth, and protecting the host plants from abiotic and biotic stresses using various strategies. In the present study, endophytic fungi were isolated from wild and endemic apple cultivars, followed by characterizing their antifungal effect against . To characterize the endophytic fungi, 417 fungal strains were separated from 210 healthy fruit, leaf, and branch samples collected from the north of Iran. Among the purified fungal isolates, 33 fungal genera were identified based on the morphological characteristics, of which 38 species were detected according to the morphological features and molecular data of ITS, , and genomic regions (related to the genus). The results represented that most of the endophytic fungi belonged to Ascomycota (67.8%), 31.4% of isolates were mycelia sterilia, while the others were Basidiomycota (0.48%) and Mucoromycota (0.24%). Additionally, , , and were determined as the dominant genera. The antifungal properties of the identified isolates were evaluated against to determine the release of media-permeable metabolites, Volatile Organic Compounds (VOCs), chitinase, and cellulase as antifungal mechanisms, as well as producing phosphate solubilisation as growth-promoting effect. Based on the results of metabolite and VOC tests, the six isolates of GO13S1, 55S2, 61S2, 7F2, 2S1 and 3 L2 were selected for greenhouse tests. Further, 55S2 and 61S2 could solubilize inorganic phosphate. All isolates except 3 L2 exhibited cellulase activity, while chitinase activity was observed in 2S1, 3 L2, and 61S2. Finally, 55S2 and 2S1 completely controlled the disease on the apple seedling leaves under greenhouse conditions.
PubMed: 36419433
DOI: 10.3389/fmicb.2022.1024001 -
Molecules (Basel, Switzerland) Jul 2018In this study, the co-culture of and , the endophytes in the seeds of , were examined for metabolite diversity. Five new azaphilones were isolated, and their structures...
In this study, the co-culture of and , the endophytes in the seeds of , were examined for metabolite diversity. Five new azaphilones were isolated, and their structures were determined by spectral analysis. In terms of azaphilones, compound had an unprecedented skeleton, with a bicyclic oxygen bridge. The antifungal selectivities of the metabolite produced by against its co-culture fungus, , and common pathogens exhibited competitive interaction in this mix-culture. Compounds and showed obvious nitric oxide (NO) inhibitory activity with ratios of 37%, and 39%, respectively, at a concentration of 50 μM.
Topics: Antibiosis; Antifungal Agents; Ascomycota; Benzopyrans; Coculture Techniques; Endophytes; Magnetic Resonance Spectroscopy; Molecular Structure; Pigments, Biological
PubMed: 30037113
DOI: 10.3390/molecules23071816 -
Frontiers in Plant Science 2022Endophytic microbes are vital for nutrient solubilization and uptake, growth, and survival of plants. Here, 88 endophytic actinobacteria (EnA) associated with five tea...
Endophytic microbes are vital for nutrient solubilization and uptake, growth, and survival of plants. Here, 88 endophytic actinobacteria (EnA) associated with five tea clones were isolated, assessed for their diversity, plant growth promoting (PGP), and biocontrol traits, and then used as an inoculant for PGP and disease control in host and non-host plants. Polyphasic methods, including phenotypic and genotypic characteristics led to their identification as , and Out of 88 isolates, 35 (39.77%) showed antagonistic activity against major fungal pathogens, viz. , . Regarding PGP activities, the percentage of isolates that produced indole acetic acid, siderophore, and ammonia, as well as P-solubilisation and nitrogen fixation, were 67.05, 75, 80.68, 27.27, 57.95, respectively. A total of 51 and 42 isolates showed chitinase and 1-aminocyclopropane-1-carboxylic acid deaminase activity, respectively. Further, two potent strains KA12 and MA34, selected based on the bonitur scale, were screened for biofilm formation ability and tested under nursery conditions. Confocal laser scanning microscopy and the crystal violet staining technique revealed that these strains can form biofilms, indicating the potential for plant colonization. In the nursery experiment, they significantly enhanced the shoot and root biomass, shoot and root length, and leaf number in host tea plants. Additionally, treatment of tomato seeds by KA12 suppressed the growth of fungal pathogen , increased seed germination, and improved root architecture, demonstrating its ability to be used as a seed biopriming agent. Our results confirm the potential of tea endophytic actinobacterial strains with multifarious beneficial traits to enhance plant growth and suppress fungal pathogens, which may be used as bioinoculant for sustainable agriculture.
PubMed: 36438109
DOI: 10.3389/fpls.2022.989794 -
Mycology 2019A new compound, nigronapthaphenyl, was extracted from the endophytic fungus isolated from a mangrove plant . The structure of the compound was elucidated by analysis of... (Review)
Review
A new compound, nigronapthaphenyl, was extracted from the endophytic fungus isolated from a mangrove plant . The structure of the compound was elucidated by analysis of 1D and 2D NMR spectra and mass spectrometric data. It was tested for its antimicrobial activity, cytotoxicity, anti-inflammatory activity and for its ability to inhibit α-glucosidase. Nigronapthaphenyl showed antibacterial activities against TISTR 088 and TISTR 688 with MIC values of 4 and 2 μg/mL respectively. Cytotoxicity against colon cancer cell line HCT 116 was found to be an IC value of 9.62 ± 0.5 μM . This further showed potential anti-inflammatory activity amounting to an IC of 6.2 ± 0.5 μM and also α-glucosidase inhibitory activity, with an IC value of 6.9 ± 0.5 μM.
PubMed: 31632831
DOI: 10.1080/21501203.2019.1620892 -
Journal of Fungi (Basel, Switzerland) Feb 2024Rice production in the Anhui province is threatened by fungal diseases. We obtained twenty-five fungal isolates from rice and wild rice leaves showing leaf spot disease...
Rice production in the Anhui province is threatened by fungal diseases. We obtained twenty-five fungal isolates from rice and wild rice leaves showing leaf spot disease collected along the Yangtze River. A phylogenetic analysis based on internal transcribed spacer (ITS), translation elongation factor 1 alpha (), and beta tubulin () sequences revealed one isolate (SS-2-JB-1B) grouped with , one (QY) with , twenty-two with , and one isolate (QY-2) grouped in its own clade, which are related to but clearly different from . Nineteen tested isolates, including sixteen strains from the clade and the three isolates of the other three clades, caused disease on detached rice leaves. The three isolates that did not belong to were also able to cause disease in rice seedlings, suggesting that they were rice pathogens. Isolate QY-2 differed from the other isolates in terms of colony morphology, cell size, and susceptibility to fungicides, indicating that this isolate represents a new species that we named . Our analysis showed that , , and the new species, , can cause rice leaf spot disease in the field. This research provides new knowledge for understanding rice leaf spot disease.
PubMed: 38392829
DOI: 10.3390/jof10020156