Evaluation of a fungal antagonist, Phaeotheca dimorphospora, for biological control of tree diseases

1993 ◽  
Vol 71 (3) ◽  
pp. 426-433 ◽  
Author(s):  
D. Yang ◽  
F. Plante ◽  
L. Bernier ◽  
Y. Piché ◽  
M. Dessureault ◽  
...  
Keyword(s):  
Biological Control ◽  
Morphological Changes ◽  
Heterobasidion Annosum ◽  
Dutch Elm Disease ◽  
Interference Microscopy ◽  
Tree Diseases ◽  
Antifungal Metabolites ◽  
Wide Range ◽  
Fungal Antagonist

Phaeotheca dimorphospora, which was first isolated from elm wood and found to be antagonistic in vitro against the Dutch elm disease pathogen Ophiostoma ulmi, was tested for antifungal activity in vitro against other tree pathogens by a variation of the agar layer technique. Phaeotheca dimorphospora produced antifungal compounds that were strongly inhibitory against a wide range of tree pathogens in addition to O. ulmi, such as Gremmeniella spp., Armillaria spp., Septoria musiva, Verticillium albo-atrum, Cylindrocladium floridanum, Phytophthora sp., Nectria galligena, and Heterobasidion annosum. Under light and interference microscopy, four types of morphological changes were observed in the pathogens tested: swelling of hyphae, production of resting spores such as chlamydospores and of sclerotia, extrusion of cytoplasm from hyphal tips, and bursting and destruction of mycelium. Chloroform-soluble antagonistic compounds were extracted that showed both fungicidal and fungistatic effects on the test organisms. Key words: Phaeotheca dimorphospora, biological control, fungal antagonist, hyphal interactions, antifungal metabolites, tree diseases.

scholarly journals Individual Expression of Hepatitis A Virus 3C Protease Induces Ferroptosis in Human Cells In Vitro

2021 ◽  
Vol 22 (15) ◽  
pp. 7906
Author(s):  
Alexey A. Komissarov ◽  
Maria A. Karaseva ◽  
Marina P. Roschina ◽  
Andrey V. Shubin ◽  
Nataliya A. Lunina ◽  
...  
Keyword(s):  
Cell Death ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Proteolytic Enzymes ◽  
Morphological Changes ◽  
Human Cells ◽  
Mitochondrial Potential ◽  
3C Protease ◽  
Wide Range

Regulated cell death (RCD) is a fundamental process common to nearly all living beings and essential for the development and tissue homeostasis in animals and humans. A wide range of molecules can induce RCD, including a number of viral proteolytic enzymes. To date, numerous data indicate that picornaviral 3C proteases can induce RCD. In most reported cases, these proteases induce classical caspase-dependent apoptosis. In contrast, the human hepatitis A virus 3C protease (3Cpro) has recently been shown to cause caspase-independent cell death accompanied by previously undescribed features. Here, we expressed 3Cpro in HEK293, HeLa, and A549 human cell lines to characterize 3Cpro-induced cell death morphologically and biochemically using flow cytometry and fluorescence microscopy. We found that dead cells demonstrated necrosis-like morphological changes including permeabilization of the plasma membrane, loss of mitochondrial potential, as well as mitochondria and nuclei swelling. Additionally, we showed that 3Cpro-induced cell death was efficiently blocked by ferroptosis inhibitors and was accompanied by intense lipid peroxidation. Taken together, these results indicate that 3Cpro induces ferroptosis upon its individual expression in human cells. This is the first demonstration that a proteolytic enzyme can induce ferroptosis, the recently discovered and actively studied type of RCD.

scholarly journals Potential of ChitinolyticSerratia marcescensStrain JPP1 for Biological Control ofAspergillus parasiticusand Aflatoxin

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Kai Wang ◽  
Pei-sheng Yan ◽  
Li-xin Cao ◽  
Qing-long Ding ◽  
Chi Shao ◽  
...  
Keyword(s):  
Biological Control ◽  
Morphological Changes ◽  
Agar Plate ◽  
Aflatoxin Production ◽  
Pcr Analysis ◽  
Bacterial Suspension ◽  
Fungal Cell ◽  
Coating Agent ◽  
Peanut Hulls

Serratia marcescensstrain JPP1 was isolated from peanut hulls in Huai'an city, Jiangsu Province, China. Its potential to inhibit the mycelial growth ofAspergillus parasiticusand the subsequent aflatoxin production was evaluated. The strain JPP1 could produce chitinase to degrade fungal cell walls, which was the main mechanism of strain JPP1 for biocontrol. Scanning electron microscopy of fungi treated with the crude chitinase revealed abnormal morphological changes. While the strain was grown in the peanut hulls-based medium, the chitinase activity reached 7.39 units. RT-PCR analysis showed that the crude chitinase repressed the transcription of genes involved in the aflatoxin gene cluster, such as aflR, aflC (pksL1), and aflO (dmtA) genes. By visual agar plate assay and tip culture method, the strain JPP1 exhibited remarkable inhibitory effect on mycelia growth (antifungal ratio >95%) and subsequent aflatoxin production (antiaflatoxigenic ratio >98%). Anin vitroassay with seed coating agent of bacterial suspension showed that strain JPP1 effectively reduced fungal growth and subsequent aflatoxin production on peanut seeds, and its antagonistic effect was superior to the common agricultural fungicide of carbendazim. These characteristics suggest thatS. marcescensJPP1 strain could potentially be utilized for the biological control of phytopathogenic fungi and aflatoxin in Chinese peanut main producing areas.

scholarly journals Streptomyces sp.: Characterization, Identification and Its Potential as a Ralstonia solanacearum Biological Control Agent in vitro

2019 ◽  
Vol 2 (3) ◽  
pp. 89-96 ◽  
Author(s):  
Rachmad Saputra ◽  
Triwidodo Arwiyanto ◽  
Arif Wibowo
Keyword(s):  
Biological Control ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Biological Control Agent ◽  
Wilt Disease ◽  
Molecular Characteristics ◽  
Streptomyces Sp ◽  
Bacterial Wilt Disease ◽  
Wide Range

Streptomyces sp. bacteria have the potential to produce antibiotic compounds, which are one of the mechanisms that are widely used in biological control. However, in general, biological control mechanisms also occur through competition, cell wall degradation and induced resistance. This study was aimed to determine the physiological, biochemical and molecular characteristics of two isolates of Streptomyces sp. (S-4 and S16 isolates) isolated from the tomatoes roots, and to find out their ability to control Ralstonia solanacearum, which causes bacterial wilt disease on a wide range of hosts. The results showed both Streptomyces sp. isolates had several different physiological and biochemical characteristics and had a different ability to inhibit R. solanacearum in vitro. Streptomyces sp. S-16 isolate had a high similarity with Streptomyces diastaticus subsp. ardesiacus strain NRRL B-1773T based on the molecular identification results. Further research needs to be done to see the potential inhibition of the two Streptomyces isolates in inhibiting the development of bacterial wilt disease in tomato plants caused by R. solanacearum.

scholarly journals Trichoderma: a beneficial antifungal agent and insights into its mechanism of biocontrol potential

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Ria Mukhopadhyay ◽  
Deepak Kumar
Keyword(s):  
Biological Control ◽  
G Protein ◽  
Plant Pathogens ◽  
Hydrolytic Enzymes ◽  
Main Body ◽  
Antifungal Metabolites ◽  
Camp Pathway ◽  
Wide Range ◽  
Biocontrol Potential ◽  
Chemical Pesticides

Abstract Background Agriculture is an indispensable part of any country to feed the millions of people but it is under constant threat of pests. To protect the crops from this huge yield loss recently, chemical pesticides are used. Though chemical pesticides have shown effective results in killing the crop pests, it causes negative impact on the environment as well as humans. So to find an eco-friendly alternative, biological control methods are being used. Main body Biological control is a great renaissance of interest and research in microbiological balance to control soil-borne plant pathogens and leads to the development of a better farming system. In biological control, genus Trichoderma serves as one of the best bioagents, which is found to be effective against a wide range of soil and foliar pathogens. Genus Trichoderma is a soil inhabiting green filamentous fungus, which belongs to the division Ascomycota. The efficacy of Trichoderma depends on many abiotic parameters such as soil pH, water retention, temperature and presence of heavy metals. The biocontrol potential of Trichoderma spp. is due to their complex interaction with plant pathogens either by parasitizing them, secreting antibiotics or by competing for space and nutrients. During mycoparasitic interactions, production of hydrolytic enzymes such as glucanase, chitinase and protease and also signalling pathways are initiated by Trichoderma spp. and the important ones are Heterotrimeric G protein, MAP kinase and cAMP pathway. G protein and MAPK are mainly involved in secretion of antifungal metabolites and the formation of infection structures. cAMP pathway helps in the condition and coiling of Trichoderma mycelium on pathogenic fungi and inhibits their proliferation. Short conclusion Trichoderma being an efficient biocontrol agent, their characteristics and mechanisms should be well understood to apply them in field conditions to restrict the proliferation of phytopathogens.

Biological control of damping-off of sugar-beet and cotton with Chaetomium globosum or a fluorescent Pseudomonas sp.

1988 ◽  
Vol 34 (5) ◽  
pp. 631-637 ◽  
Author(s):  
D. Walther ◽  
D. Gindrat
Keyword(s):  
Biological Control ◽  
Sugar Beet ◽  
Seed Treatment ◽  
Pythium Ultimum ◽  
Chaetomium Globosum ◽  
Pseudomonas Sp ◽  
Damping Off ◽  
Antifungal Metabolites ◽  
Fluorescent Pseudomonas

Seed treatment with ascospores of Chaetomium globosum reduced damping-off of sugar-beet caused by seed-borne Phoma betae and soil-borne Pythium ultimum or Rhizoctonia solani in growth chamber experiments. Seed treatment with a fluorescent Pseudomonas sp. controlled Ph. betae and P. ultimum but not R. solani. Coating cotton seeds with ascospores controlled P. ultimum and R. solani damping-off. In some experiments, biological seed treatments were equally or more effective than seed treatment with captan. However, greater variability in disease control occurred with the antagonists than with captan. Fifty percent of freshly harvested ascospores of C. globosum germinated in 8 h on water agar. When ascospores were stored under air-dried conditions for 3 days to 2.5 years, germination increased to > 90%. Under same storage conditions, survival of Pseudomonas sp. was detected after 4 months. Antagonistic activities observed in vitro were hyphal coiling of C. globosum on R. solani, and mycostasis was induced by C. globosum or Pseudomonas sp. on agar and soil. The presumed cause of mycostasis is the diffusible antifungal metabolites which may also be involved in the biological control of damping-off.

In Vitro Examination of Poly(glycerol sebacate) Degradation Kinetics: Effects of Porosity and Cure Temperature

2014 ◽  
Vol 1621 ◽  
pp. 87-92 ◽  
Author(s):  
Nadia M. Krook ◽  
Courtney LeBlon ◽  
Sabrina S. Jedlicka
Keyword(s):  
Biomedical Applications ◽  
Degradation Kinetics ◽  
Morphological Changes ◽  
Scanning Calorimetry ◽  
Tissue Engineering Scaffolds ◽  
Degradation Study ◽  
Wide Range ◽  
Thermal Changes ◽  
Cure Temperature

ABSTRACTPoly(glycerol sebacate) (PGS) is a biodegradable and biocompatible elastomer that has been used in a wide range of biomedical applications. While a porous format is common for tissue engineering scaffolds, to allow cell ingrowth, PGS degradation has been primarily studied in a nonporous format. The purpose of this research was to investigate the degradation of porous PGS at three frequently used cure temperatures: 120°C, 140°C, and 165°C. The thermal, chemical, mechanical, and morphological changes were examined using thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy, compression testing, and scanning electron microscopy. Over the course of the 16-week degradation study, the samples’ pores collapsed. The specimens cured at 120°C demonstrated the most degradation and became gel-like after 16 weeks. Thermal changes were most evident in the 120°C and 140°C cure PGS specimens, as shifts in the melting and recrystallization temperatures occurred. Porous samples cured at all three temperatures displayed a decrease in compressive modulus after 16 weeks. This in vitro study helped to elucidate the effects of porosity and cure temperature on the biodegradation of PGS and will be valuable for the design of future PGS scaffolds.

Phaeotheca dimorphospora increases Trichoderma harzianum density in soil and suppresses red pine damping-off caused by Cylindrocladium scoparium

1995 ◽  
Vol 73 (5) ◽  
pp. 693-700 ◽  
Author(s):  
D. Yang ◽  
L. Bernier ◽  
M. Dessureault
Keyword(s):  
Biological Control ◽  
Trichoderma Harzianum ◽  
Plant Pathogens ◽  
Disease Incidence ◽  
Pinus Resinosa ◽  
Red Pine ◽  
Damping Off ◽  
Fungal Antagonist ◽  
Petri Dishes

A fungal antagonist, Phaeotheca dimorphospora, was tested for its ability to control damping-off of red pine (Pinus resinosa) caused by Cylindrocladium scoparium. In vitro, the germination of seeds coated with P. dimorphospora microconidia was significantly increased by 10% compared with uncoated seeds. In experiments carried out in Petri dishes, addition of P. dimorphospora into soil significantly reduced the population of C. scoparium and disease incidence. In the greenhouse, application of P. dimorphospora into the top layer of soil reduced pre- and post-emergence damping-off by 79.5%. Under greenhouse conditions, P. dimorphospora stimulated the population of Trichoderma harzianum, a well-known antagonist of soil-borne plant pathogens. In soil treated with P. dimorphospora, the number of propagules of T. harzianum was 100–500 times higher than in the untreated control, whereas the population of C. scoparium decreased rapidly and was not detectable 1 month after sowing. Key words: Phaeotheca dimorphospora, Trichoderma harzianum, Cylindrocladium scoparium, damping-off, biological control, fungal antagonist, Pinus resinosa.

scholarly journals Impact of Trichoderma sp. on the Development of Heterobasidion Annosum in Decayed Understory Picea Abies Stumps

2017 ◽  
Vol 71 (1-2) ◽  
pp. 52-56
Author(s):  
Kristīne Kenigsvalde ◽  
Dina Nitiša ◽  
Dace Saulīte ◽  
Kari Korhonen ◽  
Līvija Vulfa ◽  
...  
Keyword(s):  
Biological Control ◽  
Field Studies ◽  
Antagonistic Effect ◽  
Heterobasidion Annosum ◽  
Economic Losses ◽  
Biological Control Agents ◽  
Trichoderma Sp ◽  
The Impact ◽  
Trichoderma Isolates

Abstract Heterobasidion annosum (Fr.) Bref. s.l. causes significant economic losses in conifer forests. Therefore, to reduce the spread of the infection surfaces of freshly cut conifer, stumps are commonly treated with biological control agents. Trichoderma sp. shows very strong antagonistic effect against H. annosum in vitro, but relatively few field studies have been conducted. Moreover, most of previous studies examined the impact of Trichoderma sp. on H. annosum in healthy conifer stumps. The aim of our work was to evaluate the effect of Trichoderma sp. against H. annosum in already decayed understory spruce stumps. In total, 75 decayed spruce stumps were surveyed. Part of the spruce stumps were left as a control, and the others were treated with one of two Trichoderma isolates (T472 and T945) belonging to two different species: T. viridescens and T. viride. The occurrence of H. annosum was evaluated 3 and 12 months after treatment. The main results were that the area of previously healthy wood occupied by H. annosum was larger in control stumps in comparison with treated stumps, but the differences were not statistically significant.

scholarly journals Behaviour and neuropathology in mice injected with human contactin-associated protein 2 antibodies

Brain ◽  
2019 ◽  
Vol 142 (7) ◽  
pp. 2000-2012 ◽  
Author(s):  
Maria Pia Giannoccaro ◽  
David A Menassa ◽  
Leslie Jacobson ◽  
Ester Coutinho ◽  
Gennaro Prota ◽  
...  
Keyword(s):  
Working Memory ◽  
Social Interactions ◽  
Hippocampal Neurons ◽  
Morphological Changes ◽  
Brain Regions ◽  
Complement C3 ◽  
Short Term ◽  
Wide Range ◽  
Fos Expression

Abstract Serum antibodies that bind to the surface of neurons or glia are associated with a wide range of rare but treatable CNS diseases. In many, if not most instances, the serum levels are higher than CSF levels yet most of the reported attempts to reproduce the human disease in mice have used infusion of antibodies into the mouse cerebral ventricle(s) or intrathecal space. We used the intraperitoneal route and injected purified plasma IgG from either a CASPR2-antibody-positive patient (n = 10 mice) or healthy individual (n = 9 mice) daily for 8 days. Lipopolysaccharide was injected intraperitoneally on Day 3 to cause a temporary breach in the blood brain barrier. A wide range of baseline behaviours, including tests of locomotion, coordination, memory, anxiety and social interactions, were established before the injections and tested from Day 5 until Day 11. At termination, brain tissue was analysed for human IgG, CASPR2 and c-fos expression, lymphocyte infiltration, and neuronal, astrocytic and microglial markers. Mice exposed to CASPR2-IgG, compared with control-IgG injected mice, displayed reduced working memory during the continuous spontaneous alternation test with trends towards reduced short-term and long-term memories. In the open field tests, activities were not different from controls, but in the reciprocal social interaction test, CASPR2-IgG injected mice showed longer latency to start interacting, associated with more freezing behaviour and reduced non-social activities of rearing and grooming. At termination, neuropathology showed more IgG deposited in the brains of CASPR2-IgG injected mice, but a trend towards increased CASPR2 expression; these results were mirrored in short-term in vitro experiments where CASPR2-IgG binding to hippocampal neurons and to CASPR2-transfected HEK cells led to some internalization of the IgG, but with a trend towards higher surface CASPR2 expression. Despite these limited results, in the CASPR2-IgG injected mouse brains there was increased c-fos expression in the piriform-entorhinal cortex and hypothalamus, and a modest loss of Purkinje cells. There was also increased microglia density, morphological changes in both microglia and astrocytes and raised complement C3 expression on astrocytes, all consistent with glial activation. Patients with CASPR2 antibodies can present with a range of clinical features reflecting central, autonomic and peripheral dysfunction. Although the behavioural changes in mice were limited to social interactions and mild working-memory defects, the neuropathological features indicate potentially widespread effects of the antibodies on different brain regions.

scholarly journals FLARIM v2.0, an improved method to quantify transcript-ribosome interactions in vivo in the adult Drosophila brain

2021 ◽  
Author(s):  
Petra Richer ◽  
Sean D Speese ◽  
Mary A Logan
Keyword(s):  
Immune Response ◽  
Morphological Changes ◽  
Immune Gene ◽  
Promising Tool ◽  
Matrix Metalloproteinase 1 ◽  
New Variant ◽  
Wide Range ◽  
Drosophila Brain

Neural injury triggers striking immune reactions from glial cells, including significant transcriptional and morphological changes, but it is unclear how these events are coordinated to mount an effective immune response. Here, we present a new variant of the Fluorescence assay to detect ribosome interactions with mRNA (FLARIM), which we term FLARIM v2.0, to visualize single immune gene transcripts and association with ribosomes in glia responding to neurodegeneration. Specifically, using an in vivo axotomy assay in Drosophila, we show that matrix metalloproteinase-1 (Mmp-1) mRNAs and associated ribosomes are detected in distal processes of reactive glia where they are actively engulfing degenerating axonal material, suggesting that local translation is an important component of the glial immune response to axotomy. This work also validates our enhanced FLARIM assay as a promising tool to investigate mechanisms of mRNA transport and translation in a wide range of in vitro and in vivo paradigms.

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