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J. E. Hudgins - One of the best experts on this subject based on the ideXlab platform.
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first report of a leaf spot and stem canker caused by Myrothecium roridum on watermelon in the united states
Plant Disease, 2005Co-Authors: Kenneth W. Seebold, David B. Langston, Robert C. Kemerait, J. E. HudginsAbstract:Myrothecium roridum Tode:Fr, pathogenic to a number of cucurbit species, causes fruit rots, cankers on crowns and stems, and leaf spots. Hosts include cantaloupe and honeydew (Cucurbita melo) and cucumber (Cucumis sativus) (1,3). In June 2004, following a period of heavy rainfall, numerous round-to-oblong, brown lesions with concentric rings were observed on leaves of watermelon (Citrullus lanatus) cv. Desert King at the Blackshank Farm in Tifton, GA. Disease was localized in the field and severity was low (<5% of leaf area affected). No symptoms were observed on fruit. Sections of tissue were removed from the margin between healthy and diseased tissue and plated on acidified, 25% potato dextrose agar (aPDA). A small plug of agar and mycelium were removed from colonies that emerged from lesions and were transferred to aPDA. Isolated colonies were characterized by a white, floccose mycelium with concentric, dark green-to-black rings of sporodochia bearing viscid masses of conidia. Conidia were cylindrical with rounded ends and measured 6 to 8 × 1.5 to 2.5 μm. The features of the fungus were consistent with the description of Myrothecium roridum (1,2). Pathogenicity tests were conducted in a temperature-controlled greenhouse. Twenty-five watermelon plants (cv. Desert King) were inoculated with a conidial suspension of M. roridum (5 × 105 conidia per ml) plus 0.1% vol/vol Tween 20. Inoculum was applied on leaves and stems until runoff with a hand-held mister, and plants were placed in a dew chamber for 72 h. Ten plants were sprayed with sterile, distilled water to serve as controls. Inoculated and noninoculated control plants were removed from the dew chamber and maintained at 25 to 28°C. Symptoms appeared 8 days after inoculation and were characterized by round, dark lesions with concentric rings; noninoculated plants were symptomless. Sections of symptomatic tissue were plated, and M. roridum was reisolated. Although M. roridum is a common pathogen of melons and cucumber, to our knowledge, this is the first field report of a leaf spot caused by M. roridum on watermelon in the United States. No further occurrences of the disease on watermelon have been observed in Georgia since the initial discovery of M. roridum in 2004; however, losses could be potentially severe if widespread infection of fruit were to occur. References: (1) B. D. Bruton. Crater Rot. Pages 49-50 in: Compendium of Cucurbit Diseases. T. A. Zitter et al., eds. The American Phytopathological Society, St. Paul, MN, 1996. (2) M. B. Ellis. Page 552 in: Dematiaceous Hyphomycetes. CAB International, Wallingford, UK, 1971. (3) D. F. Farr et al. Page 809 in: Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989.
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First Report of a Leaf Spot and Stem Canker Caused by Myrothecium roridum on Watermelon in the United States
Plant disease, 2005Co-Authors: Kenneth W. Seebold, David B. Langston, Robert C. Kemerait, J. E. HudginsAbstract:Myrothecium roridum Tode:Fr, pathogenic to a number of cucurbit species, causes fruit rots, cankers on crowns and stems, and leaf spots. Hosts include cantaloupe and honeydew (Cucurbita melo) and cucumber (Cucumis sativus) (1,3). In June 2004, following a period of heavy rainfall, numerous round-to-oblong, brown lesions with concentric rings were observed on leaves of watermelon (Citrullus lanatus) cv. Desert King at the Blackshank Farm in Tifton, GA. Disease was localized in the field and severity was low (
W.o. Okunowo - One of the best experts on this subject based on the ideXlab platform.
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optimization of Myrothecium roridum tode fries phytotoxin production and bioactivity on water hyacinth eichhornia crassipes
Toxin Reviews, 2021Co-Authors: W.o. Okunowo, A. A. Osuntoki, Adedotun Adeyinka Adekunle, George O. Gbenle, Hamed K. Abbas, W. T. ShierAbstract:Phytotoxin production by Myrothecium roridum Tode: Fries (IMI 394934) and in vitro bioactivity on water hyacinth leaves (WHL) were evaluated. Phytotoxin produced caused necrosis of WHL three days p...
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Optimization of Myrothecium roridum tode: fries phytotoxin production and bioactivity on water hyacinth (Eichhornia crassipes)
Toxin Reviews, 2019Co-Authors: W.o. Okunowo, A. A. Osuntoki, Adedotun Adeyinka Adekunle, George O. Gbenle, Hamed K. Abbas, W. T. ShierAbstract:AbstractPhytotoxin production by Myrothecium roridum Tode: Fries (IMI 394934) and in vitro bioactivity on water hyacinth leaves (WHL) were evaluated. Phytotoxin produced caused necrosis of WHL thre...
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occurrence and effectiveness of an indigenous strain of Myrothecium roridum tode fries as a bioherbicide for water hyacinth eichhornia crassipes in nigeria
Biocontrol Science and Technology, 2013Co-Authors: W.o. Okunowo, A. A. Osuntoki, A A Adekunle, George O. GbenleAbstract:In a study to isolate fungal pathogens with potential for the biocontrol of water hyacinth (Eichhornia crassipes), some lakes in the Lagos State and its environs, Nigeria, were surveyed for diseased water hyacinth (E. crassipes). The fungi present in the diseased tissue were isolated and identified as: Aspergillus niger, Aspergillus flavus, Penicillium sp., Curvularia pallescens, Fusarium solani and Myrothecium roridum. The pathogenicity of isolates of these fungi on fresh, non-diseased water hyacinth plants was investigated. Myrothecium was the only species capable of inducing disease symptoms. Necrosis was observed on water hyacinth leaves three days post inoculation (DPI) with M. roridum (1 × 106 spores/ml). The leaves and the petioles were withered at the end of day 24, and the disease incidence and disease severity were 100% and 8.67%, respectively. Molecular analysis of the internal transcribed spacer rDNA of the M. roridum isolate from water hyacinth showed >98% homology to authenticated sequences ...
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production of cellulolytic and xylanolytic enzymes by a phytopathogenic Myrothecium roridum and some avirulent fungal isolates from water hyacinth
African Journal of Biotechnology, 2010Co-Authors: W.o. Okunowo, A. A. Osuntoki, George O. Gbenle, A A Adekunle, Sikiru Abiola OjokukuAbstract:The cellulolytic and xylanolytic activity of a pathogenic Myrothecium roridum Tode (IMI 394934) and non-pathogenic Fusarium solani and Curvularia pallescence Boedjin isolates from water hyacinth were investigated. The mycelial plugs of each isolate was grown in submerged cultures of Czapeck Dox broth containing the appropriate carbon source (carboxymethylcellulose, sawdust and homogenized dry water hyacinth leaf) at 25°C for 16 days. The enzyme activity assay was carried out on the culture filtrates obtained. This was measured as micromole sugar released per min. The result obtained showed that the enzyme activity (U/ml) for b-1,4-exoglucanase, b-1,4-endoglucanase and xylanase was maximum 3.70 ± 0.43, 0.95 ± 0.03 and 2.32 ± 0.10, respectively, in C. pallescens Boedjin grown on carboxymethylcellulose and minimum 0.12 ± 0.02, 0.13 ± 0.03 and 0.34 ± 0.01 respectively, in M. roridum grown on homogenized dry water hyacinth leaf. The b-glucosidase activity (U/ml) was highest, 1.74 ± 0.06 in M. roridum grown on sawdust and least, 0.08 ± 0.00 in C. pa llescens Boedjin grown on homogenized water hyacinth leaf broth. The maximum (324.00 ± 19.51 mg/ml) and minimum (130.00 ±5.83 mg/ml) total extracellular protein was produced in M. roridum grown on homogenized dry water hyacinth leaf and carboxymethylcellulose, respectively. This study showed that the phytopathogenic strain of M. roridum is capable of producing cellulases and xylanase enzyme in submerged cultures but to a lesser degree compared to F. solani and C. pallescence Boedjin.
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Media studies on Myrothecium roridum Tode: A potential biocontrol agent for water hyacinth
2010Co-Authors: W.o. Okunowo, A. A. Osuntoki, George O. Gbenle, Adedotun Adeyinka AdekunleAbstract:Water hyacinth ( Eichhornia crassipes ) is a noxious aquatic weed in Nigeria and many parts of the world. A potential mycoherbicidal agent for the control has been identified recently as Myrothecium roridum Tode. The best media for in-vitro propagation was investigated using seven culture media; potato dextrose agar (PDA), malt extract agar (MEA), potato sucrose agar (PSA), sabouraud agar (SA), potato carrot agar (PCA), Czapek-Dox agar (ZA) and a semi artificial diet, which included the material from the fungal host’s plant (WHA). The effect of nitrogen sources (ammonium chloride, sodium nitrate, ammonium nitrate, sodium glutamate and glutamine) and pH on the growth of the fungus was also determined. The mycelia growth was assessed by diameter measurement on agar plates and the conidial yield was measured with a Neubauer hemocytometer slide. The mycelia growth was maximum on PSA and minimum on ZA. The conidial yield was highest on MEA. The mycelia growth and spore concentration of the fungus were highest on sodium glutamate and glutamine respectively, when used as nitrogen sources. The optimal growth pH was 5.5.
Somdej Kanokmedhakul - One of the best experts on this subject based on the ideXlab platform.
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types a and d trichothecene mycotoxins from the fungus Myrothecium roridum
Planta Medica, 2019Co-Authors: Waranya Lakornwong, Arm Unartngam, Kwanjai Kanokmedhakul, Kasem Soytong, Sarawut Tontapha, Vittaya Amornkitbamrung, Somdej KanokmedhakulAbstract:Chromatographic separation of extracts from the fungal biomass of a plant pathogenic fungus, Myrothecium roridum, yielded 8 trichothecene toxins including 6 type D trichothecenes (1–6) and 2 type A trichothecenes (7–8). 6′,12′-Epoxymyrotoxin A (1) and 7′-hydroxymytoxin B (2) were new macrocyclic trichothecenes, while the other trichothecenes were identified as myrotoxin B (3), myrotoxin D hydrate (4), 2′,3′-epoxymyrothecine A (5), miotoxin A (6), and 2 trichothecenes lacking the macrocyclic lactone system, roridin L-2 (7) and trichoverritone (8). The structures of these mycotoxins were characterized using spectroscopic methods. The absolute configurations of 1 and 2 were determined by NOESY and a comparison of their experimental and calculated ECD spectra. Most of these mycotoxins (1–4 and 6) exhibited highly potent antimalarial activity against Plasmodium falciparum. They also showed strong cytotoxicity towards KB and NCI-H187 cell lines (IC50 0.60 – 112.28 nM), as well as the Vero cell line (IC50 1.50 – 46.51 nM).
Taomei Liu - One of the best experts on this subject based on the ideXlab platform.
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de novo transcriptome analysis of plant pathogenic fungus Myrothecium roridum and identification of genes associated with trichothecene mycotoxin biosynthesis
International Journal of Molecular Sciences, 2017Co-Authors: Taomei Liu, Weimin Zhang, Muzi Zhu, Zilei HuangAbstract:Myrothecium roridum is a plant pathogenic fungus that infects different crops and decreases the yield of economical crops, including soybean, cotton, corn, pepper, and tomato. Until now, the pathogenic mechanism of M. roridum has remained unclear. Different types of trichothecene mycotoxins were isolated from M. roridum, and trichothecene was considered as a plant pathogenic factor of M. roridum. In this study, the transcriptome of M. roridum in different incubation durations was sequenced using an Illumina Hiseq 2000. A total of 35,485 transcripts and 25,996 unigenes for M. roridum were obtained from 8.0 Gb clean reads. The protein–protein network of the M. roridum transcriptome indicated that the mitogen-activated protein kinases signal pathway also played an important role in the pathogenicity of M. roridum. The genes related to trichothecene biosynthesis were annotated. The expression levels of these genes were also predicted and validated through quantitative real-time polymerase chain reaction. Tri5 gene encoding trichodiene synthase was cloned and expressed, and the purified trichodiene synthase was able to catalyze farnesyl pyrophosphate into different kinds of sesquiterpenoids.Tri4 and Tri11 genes were expressed in Escherichia coli, and their corresponding enzymatic properties were characterized. The phylogenetic tree of trichodiene synthase showed a great discrepancy between the trichodiene synthase from M. roridum and other species. Our study on the genes related to trichothecene biosynthesis establishes a foundation for the M. roridum hazard prevention, thus improving the yields of economical crops.
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two trichothecene mycotoxins from Myrothecium roridum induce apoptosis of hepg 2 cells via caspase activation and disruption of mitochondrial membrane potential
Molecules, 2016Co-Authors: Yuchan Chen, Hongxin Liu, Zhanghua Sun, Weimin Zhang, Taomei LiuAbstract:Trichothecene mycotoxins are a type of sesquiterpenoid produced by various kinds of plantpathogenic fungi. In this study, two trichothecene toxins, namely, a novel cytotoxic epiroridin acid and a known trichothecene, mytoxin B, were isolated from the endophytic fungus Myrothecium roridum derived from the medicinal plant Pogostemon cablin. The two trichothecene mytoxins were confirmed to induce the apoptosis of HepG-2 cells by cytomorphology inspection, DNA fragmentation detection, and flow cytometry assay. The cytotoxic mechanisms of the two mycotoxins were investigated by quantitative real time polymerase chain reaction, western blot, and detection of mitochondrial membrane potential. The results showed that the two trichothecene mycotoxins induced the apoptosis of cancer cell HepG-2 via activation of caspase-9 and caspase-3, up-regulation of bax gene expression, down-regulation of bcl-2 gene expression, and disruption of the mitochondrial membrane potential of the HepG-2 cell. This study is the first to report on the cytotoxic mechanism of trichothecene mycotoxins from M. roridum. This study provides new clues for the development of attenuated trichothecene toxins in future treatment of liver cancer.
George O. Gbenle - One of the best experts on this subject based on the ideXlab platform.
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optimization of Myrothecium roridum tode fries phytotoxin production and bioactivity on water hyacinth eichhornia crassipes
Toxin Reviews, 2021Co-Authors: W.o. Okunowo, A. A. Osuntoki, Adedotun Adeyinka Adekunle, George O. Gbenle, Hamed K. Abbas, W. T. ShierAbstract:Phytotoxin production by Myrothecium roridum Tode: Fries (IMI 394934) and in vitro bioactivity on water hyacinth leaves (WHL) were evaluated. Phytotoxin produced caused necrosis of WHL three days p...
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Optimization of Myrothecium roridum tode: fries phytotoxin production and bioactivity on water hyacinth (Eichhornia crassipes)
Toxin Reviews, 2019Co-Authors: W.o. Okunowo, A. A. Osuntoki, Adedotun Adeyinka Adekunle, George O. Gbenle, Hamed K. Abbas, W. T. ShierAbstract:AbstractPhytotoxin production by Myrothecium roridum Tode: Fries (IMI 394934) and in vitro bioactivity on water hyacinth leaves (WHL) were evaluated. Phytotoxin produced caused necrosis of WHL thre...
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occurrence and effectiveness of an indigenous strain of Myrothecium roridum tode fries as a bioherbicide for water hyacinth eichhornia crassipes in nigeria
Biocontrol Science and Technology, 2013Co-Authors: W.o. Okunowo, A. A. Osuntoki, A A Adekunle, George O. GbenleAbstract:In a study to isolate fungal pathogens with potential for the biocontrol of water hyacinth (Eichhornia crassipes), some lakes in the Lagos State and its environs, Nigeria, were surveyed for diseased water hyacinth (E. crassipes). The fungi present in the diseased tissue were isolated and identified as: Aspergillus niger, Aspergillus flavus, Penicillium sp., Curvularia pallescens, Fusarium solani and Myrothecium roridum. The pathogenicity of isolates of these fungi on fresh, non-diseased water hyacinth plants was investigated. Myrothecium was the only species capable of inducing disease symptoms. Necrosis was observed on water hyacinth leaves three days post inoculation (DPI) with M. roridum (1 × 106 spores/ml). The leaves and the petioles were withered at the end of day 24, and the disease incidence and disease severity were 100% and 8.67%, respectively. Molecular analysis of the internal transcribed spacer rDNA of the M. roridum isolate from water hyacinth showed >98% homology to authenticated sequences ...
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production of cellulolytic and xylanolytic enzymes by a phytopathogenic Myrothecium roridum and some avirulent fungal isolates from water hyacinth
African Journal of Biotechnology, 2010Co-Authors: W.o. Okunowo, A. A. Osuntoki, George O. Gbenle, A A Adekunle, Sikiru Abiola OjokukuAbstract:The cellulolytic and xylanolytic activity of a pathogenic Myrothecium roridum Tode (IMI 394934) and non-pathogenic Fusarium solani and Curvularia pallescence Boedjin isolates from water hyacinth were investigated. The mycelial plugs of each isolate was grown in submerged cultures of Czapeck Dox broth containing the appropriate carbon source (carboxymethylcellulose, sawdust and homogenized dry water hyacinth leaf) at 25°C for 16 days. The enzyme activity assay was carried out on the culture filtrates obtained. This was measured as micromole sugar released per min. The result obtained showed that the enzyme activity (U/ml) for b-1,4-exoglucanase, b-1,4-endoglucanase and xylanase was maximum 3.70 ± 0.43, 0.95 ± 0.03 and 2.32 ± 0.10, respectively, in C. pallescens Boedjin grown on carboxymethylcellulose and minimum 0.12 ± 0.02, 0.13 ± 0.03 and 0.34 ± 0.01 respectively, in M. roridum grown on homogenized dry water hyacinth leaf. The b-glucosidase activity (U/ml) was highest, 1.74 ± 0.06 in M. roridum grown on sawdust and least, 0.08 ± 0.00 in C. pa llescens Boedjin grown on homogenized water hyacinth leaf broth. The maximum (324.00 ± 19.51 mg/ml) and minimum (130.00 ±5.83 mg/ml) total extracellular protein was produced in M. roridum grown on homogenized dry water hyacinth leaf and carboxymethylcellulose, respectively. This study showed that the phytopathogenic strain of M. roridum is capable of producing cellulases and xylanase enzyme in submerged cultures but to a lesser degree compared to F. solani and C. pallescence Boedjin.
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Media studies on Myrothecium roridum Tode: A potential biocontrol agent for water hyacinth
2010Co-Authors: W.o. Okunowo, A. A. Osuntoki, George O. Gbenle, Adedotun Adeyinka AdekunleAbstract:Water hyacinth ( Eichhornia crassipes ) is a noxious aquatic weed in Nigeria and many parts of the world. A potential mycoherbicidal agent for the control has been identified recently as Myrothecium roridum Tode. The best media for in-vitro propagation was investigated using seven culture media; potato dextrose agar (PDA), malt extract agar (MEA), potato sucrose agar (PSA), sabouraud agar (SA), potato carrot agar (PCA), Czapek-Dox agar (ZA) and a semi artificial diet, which included the material from the fungal host’s plant (WHA). The effect of nitrogen sources (ammonium chloride, sodium nitrate, ammonium nitrate, sodium glutamate and glutamine) and pH on the growth of the fungus was also determined. The mycelia growth was assessed by diameter measurement on agar plates and the conidial yield was measured with a Neubauer hemocytometer slide. The mycelia growth was maximum on PSA and minimum on ZA. The conidial yield was highest on MEA. The mycelia growth and spore concentration of the fungus were highest on sodium glutamate and glutamine respectively, when used as nitrogen sources. The optimal growth pH was 5.5.
