scholarly journals Novel Mycoviruses Discovered in the Mycovirome of a Necrotrophic Fungus

mBio ◽  
2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Ana Ruiz-Padilla ◽  
Julio Rodríguez-Romero ◽  
Irene Gómez-Cid ◽  
Davide Pacifico ◽  
María A. Ayllón
Keyword(s):  
Chemical Control ◽  
Pathogenic Fungus ◽  
Pathogenic Fungi ◽  
General Knowledge ◽  
Double Stranded Rna ◽  
Positive Sense ◽  
Dsrna Genome ◽  
Horizontal Transfers ◽  
First Time ◽  
Negative Sense

ABSTRACT Botrytis cinerea is one of the most important plant-pathogenic fungus. Products based on microorganisms can be used in biocontrol strategies alternative to chemical control, and mycoviruses have been explored as putative biological agents in such approaches. Here, we have explored the mycovirome of B. cinerea isolates from grapevine of Italy and Spain to increase the knowledge about mycoviral diversity and evolution, and to search for new widely distributed mycoviruses that could be active ingredients in biological products to control this hazardous fungus. A total of 248 B. cinerea field isolates were used for our metatranscriptomic study. Ninety-two mycoviruses were identified: 62 new mycoviral species constituting putative novel viral genera and families. Of these mycoviruses, 57 had a positive-sense single-stranded RNA (ssRNA) genome, 19 contained a double-stranded RNA (dsRNA) genome, 15 had a negative-sense ssRNA genome, and 1 contained a single-stranded DNA (ssDNA) genome. In general, ssRNA mycoviruses were widely distributed in all sampled regions, the ssDNA mycovirus was more frequently found in Spain, and dsRNA mycoviruses were scattered in some pools of both countries. Some of the identified mycoviruses belong to clades that have never been found associated with Botrytis species: Botrytis-infecting narnaviruses; alpha-like, umbra-like, and tymo-like ssRNA+ mycoviruses; trisegmented ssRNA− mycovirus; bisegmented and tetrasegmented dsRNA mycoviruses; and finally, an ssDNA mycovirus. Among the results obtained in this massive mycovirus screening, the discovery of novel bisegmented viruses, phylogenetically related to narnaviruses, is remarkable. IMPORTANCE The results obtained here have expanded our knowledge of mycoviral diversity, horizontal transfers, and putative cross-kingdom events. To date, this study presents the most extensive and wide diversity collection of mycoviruses infecting the necrotrophic fungus B. cinerea. The collection included all types of mycoviruses, with dsRNA, ssRNA+, ssRNA–, and ssDNA genomes, most of which were discovered here, and some of which were previously reported as infecting B. cinerea or other plant-pathogenic fungi. Some of these mycoviruses are reported for the first time here associated with B. cinerea, as a trisegmented ssRNA– mycovirus and as an ssDNA mycovirus, but even more remarkablly, we also describe here four novel bisegmented viruses (binarnaviruses) not previously described in nature. The present findings significantly contribute to general knowledge in virology and more particularly in the field of mycovirology.

scholarly journals Detection of virus particles and double-stranded RNA in dieback affected Dalbergia sissoo Roxb. from Bangladesh

1970 ◽  
Vol 40 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Stephanie Vogel ◽  
Hanny Tantau ◽  
Nicole Mielke-Ehret ◽  
MI Hoque ◽  
RH Sarker ◽  
...  
Keyword(s):  
Pathogenic Fungi ◽  
Plant Viruses ◽  
Forest Trees ◽  
Dalbergia Sissoo ◽  
Double Stranded Rna ◽  
Tree Disease ◽  
Virus Particles ◽  
Transmission Electron ◽  
Disease Agent ◽  
First Time

Dieback of Dalbergia sissoo Roxb. (sissoo) is a disastrous disease, which has destroyed millions of forest trees in South Asia. Plant pathogenic fungi and bacteria were found associated with diseased trees, but the causative disease agent has not yet been identified unequivocally. In order to see whether plant viruses could be detected in diseased trees, present author applied bioassays, transmission electron microscopy and double-stranded RNA (dsRNA) isolation, followed by cDNA cloning. Unknown virus particles and a complex pattern of dsRNA could be detected in leaf homogenates from dieback affected sissoo trees, in contrast to an uninfected tree. Disease associated dsRNA bands ranged in size from 0.6 to 3.5 kbp, and a cDNA clone derived from dsRNA showed partial sequence homology to a plant viral RNA polymerase. Our data indicated for the first time the presence of unknown virus(es) in dieback-affected Dalbergia sissoo in Bangladesh.  

scholarly journals CNBP Binds and Unfolds In Vitro G-Quadruplexes Formed in the SARS-CoV-2 Positive and Negative Genome Strands

2021 ◽  
Vol 22 (5) ◽  
pp. 2614
Author(s):  
Georgina Bezzi ◽  
Ernesto J. Piga ◽  
Andrés Binolfi ◽  
Pablo Armas
Keyword(s):  
Rna Virus ◽  
Cellular Protein ◽  
Molecular Approaches ◽  
Genes Expression ◽  
Positive Sense ◽  
Replicative Intermediates ◽  
Rna Genome ◽  
First Time ◽  
Negative Sense

The Coronavirus Disease 2019 (COVID-19) pandemic has become a global health emergency with no effective medical treatment and with incipient vaccines. It is caused by a new positive-sense RNA virus called severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). G-quadruplexes (G4s) are nucleic acid secondary structures involved in the control of a variety of biological processes including viral replication. Using several G4 prediction tools, we identified highly putative G4 sequences (PQSs) within the positive-sense (+gRNA) and negative-sense (−gRNA) RNA strands of SARS-CoV-2 conserved in related betacoronaviruses. By using multiple biophysical techniques, we confirmed the formation of two G4s in the +gRNA and provide the first evidence of G4 formation by two PQSs in the −gRNA of SARS-CoV-2. Finally, biophysical and molecular approaches were used to demonstrate for the first time that CNBP, the main human cellular protein bound to SARS-CoV-2 RNA genome, binds and promotes the unfolding of G4s formed by both strands of SARS-CoV-2 RNA genome. Our results suggest that G4s found in SARS-CoV-2 RNA genome and its negative-sense replicative intermediates, as well as the cellular proteins that interact with them, are relevant factors for viral genes expression and replication cycle, and may constitute interesting targets for antiviral drugs development.

scholarly journals Guanidine Hydrochloride Inhibits Mammalian Orthoreovirus Growth by Reversibly Blocking the Synthesis of Double-Stranded RNA

2007 ◽  
Vol 81 (9) ◽  
pp. 4572-4584 ◽  
Author(s):  
Kenneth E. Murray ◽  
Max L. Nibert
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Rna Synthesis ◽  
Guanidine Hydrochloride ◽  
Mrna Translation ◽  
Specific Inhibition ◽  
Double Stranded Rna ◽  
Positive Sense ◽  
Mammalian Orthoreovirus ◽  
Negative Sense

ABSTRACT Millimolar concentrations of guanidine hydrochloride (GuHCl) are known to inhibit the replication of many plant and animal viruses having positive-sense RNA genomes. For example, GuHCl reversibly interacts with the nucleotide-binding region of poliovirus protein 2CATPase, resulting in a specific inhibition of viral negative-sense RNA synthesis. The use of GuHCl thereby allows for the spatiotemporal separation of poliovirus gene expression and RNA replication and provides a powerful tool to synchronize the initiation of negative-sense RNA synthesis during in vitro replication reactions. In the present study, we examined the effect of GuHCl on mammalian orthoreovirus (MRV), a double-stranded RNA (dsRNA) virus from the family Reoviridae. MRV growth in murine L929 cells was reversibly inhibited by 15 mM GuHCl. Furthermore, 15 mM GuHCl provided specific inhibition of viral dsRNA synthesis while sparing both positive-sense RNA synthesis and viral mRNA translation. By using GuHCl to provide temporal separation of MRV gene expression and genome replication, we obtained evidence that MRV primary transcripts support sufficient protein synthesis to assemble morphologically normal viral factories containing functional replicase complexes. In addition, the coordinated use of GuHCl and cycloheximide allowed us to demonstrate that MRV dsRNA synthesis can occur in the absence of ongoing protein synthesis, although to only a limited extent. Future studies utilizing the reversible inhibition of MRV dsRNA synthesis will focus on elucidating the target of GuHCl, as well as the components of the MRV replicase complexes.

scholarly journals CRISPR-Csy4-mediated editing of rotavirus double-stranded RNA genome

2020 ◽  
Author(s):  
Guido Papa ◽  
Luca Venditti ◽  
Luca Braga ◽  
Edoardo Schneider ◽  
Mauro Giacca ◽  
...  
Keyword(s):  
Genome Editing ◽  
Double Stranded Rna ◽  
Viral Genomes ◽  
Viral Particles ◽  
Dsrna Genome ◽  
Dsrna Viruses ◽  
Level Of Understanding ◽  
Virus Genomes ◽  
First Time ◽  
Replication Intermediates

ABSTRACTCRISPR-nucleases have been widely applied for editing cellular and viral genomes, but nuclease-mediated genome editing of double-stranded RNA (dsRNA) viruses has not yet been reported. Here, by engineering CRISPR-Csy4 nuclease to localise to rotavirus viral factories, we achieved the first nuclease-mediated genome editing of rotavirus, an important human and livestock pathogen with a multi-segmented dsRNA genome. Rotavirus replication intermediates cleaved by Csy4 were repaired through the formation of defined deletions in the targeted genome segments in a single replication cycle. Using CRISPR-Csy4-mediated editing of rotavirus genome, we labelled for the first time the products of rotavirus secondary transcription made by newly assembled viral particles during rotavirus replication, demonstrating that this step largely contributes to the overall production of viral proteins. We anticipate that the nuclease-mediated cleavage of dsRNA virus genomes will promote a new level of understanding of viral replication and host-pathogen interactions, offering the opportunity to develop new therapeutics.

Effects of insecticides on adults and eggs of Drosophila suzukii (Diptera, Drosophilidae)

2017 ◽  
Vol 43 (2) ◽  
pp. 208 ◽  
Author(s):  
Daniele Cristine Hoffmann Schlesener ◽  
Jutiane Wollmann ◽  
Juliano De Bastos Pazini ◽  
Anderson Dionei Grützmacher ◽  
Flávio Roberto Mello Garcia
Keyword(s):  
North America ◽  
South America ◽  
Chemical Control ◽  
Stone Fruits ◽  
Drosophila Suzukii ◽  
Ovicidal Effect ◽  
Mere Presence ◽  
South Of Brazil ◽  
Different Cultures ◽  
First Time

Drosophila suzukii (Diptera, Drosophilidae) is an exotic species, endemic to Asia and currently a pest to small and stone fruits in several countries of North America and Europe. It was detected in 2013 for the first time in South America, in the south of Brazil. Unlike most drosophilids, this species deserves special attention, because the females are capable of oviposit inside healthy fruits, rendering their sale and export prohibited. Despite the confirmed existence of this species in different states of Brazil, this insect is yet been to be given the pest status. Nevertheless, the mere presence of this species is enough to cause concern to producers of small fruits and to justify further investigation for it’s control, especially chemical control for a possible change in status. Therefore, the goal of this work was to evaluate, in laboratory, mortality of D. suzukii adults and ovicidal effect when exposed to different insecticides registered for species of the Tephritidae and Agromyzidae families in different cultures. The insecticides deltamethrin, dimethoate, spinosad, fenitrothion, phosmet, malathion, methidathion, and zeta-cypermethrin resulted in mortality to 100 % of the subjects three days after the treatment (DAT). Regarding the effects over eggs, it was  established that the insecticides fenitrothion, malathion, and methidathion deemed 100 % of the eggs not viable, followed by phosmet and diflubenzuron, which also caused elevated reduction in the eclosion of larvae two DAT.

Cas de suie de l'érable et de chancre du peuplier dans le canton de Genève

2016 ◽  
Vol 167 (2) ◽  
pp. 98-104
Author(s):  
Bastien Cochard ◽  
François Lefort
Keyword(s):  
Internal Transcribed Spacer ◽  
Pathogenic Fungi ◽  
Fungal Flora ◽  
Acer Campestre ◽  
Cytospora Chrysosperma ◽  
Pure Cultures ◽  
Populus X Euramericana ◽  
Bark Peeling ◽  
Specific Symptoms ◽  
First Time

A case of sooty bark disease and Cytospora poplar canker in the Canton of Geneva In summer 2014, a case of sooty bark disease caused by Cryptostroma corticale on an individual field maple (Acer campestre) and two cases of poplar canker due to Cytospora chrysosperma on Populus x euramericana were identified genetically for the first time on the territory of the Canton of Geneva. In both cases, the trees presented signs of very advanced dieback, accompanied by specific symptoms such as bark peeling and sooty plaques for the maple, and loose twisted bark layers and black colouring of the wood in structural branches of the poplars. Sampling was carried out in the symptomatic areas and components of the fungal flora were isolated in pure cultures in order to identify any pathogenic fungi. The molecular analysis of the rDNA internal transcribed spacer (ITS) sequences made it possible to identify precisely all pure isolates obtained. The results showed a majority presence of C. corticale in the maple tree, and of C. chrysosperma in the two poplars. Both these fungi are little known in Switzerland and Europe, and their presence is maybe associated with changes in the climate.

First record of Pestalotiopsis spp. from affected leaves of mastic shrubs (Pestacia lentiscus L.) in northeastern of Libya.

2016 ◽  
Vol 5 (08) ◽  
pp. 4744
Author(s):  
Zahra Ibrahim El-Gali
Keyword(s):  
Signs And Symptoms ◽  
Pathogenic Fungi ◽  
First Record ◽  
Plant Pathogenic Fungi ◽  
Pistacia Lentiscus ◽  
Plant Materials ◽  
Al Jabal Al Akhdar ◽  
First Time

This study was carried out to identify the unknown different symptoms and their causes as plant pathogenic fungi from Al-Jabal Al-Akhdar District. Plant materials with fungal signs and symptoms were collected and examined. The main fungi consistently isolated from symptomatic leaves and twigs were Pestalotiopsis spp. Morphology, colony characteristics, and pathogenicity of the isolates were examined. My report the occurrence of Pestalotiopsis spp. on leaves of mastic (Pistacia lentiscus) for the first time in Libya.

scholarly journals Induction of Promoter DNA Methylation Upon High-Pressure Spraying of Double-Stranded RNA in Plants

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 789
Author(s):  
Athanasios Dalakouras ◽  
Ioannis Ganopoulos
Keyword(s):  
High Pressure ◽  
De Novo ◽  
Epigenetic Changes ◽  
Double Stranded Rna ◽  
Rna Molecules ◽  
Promoter Sequences ◽  
Promoter Dna Methylation ◽  
Promoter Dna ◽  
First Time ◽  
De Novo Methylation

Exogenous application of RNA molecules is a potent method to trigger RNA interference (RNAi) in plants in a transgene-free manner. So far, all exogenous RNAi (exo-RNAi) applications have aimed to trigger mRNA degradation of a given target. However, the issue of concomitant epigenetic changes was never addressed. Here, we report for the first time that high-pressure spraying of dsRNAs can trigger de novo methylation of promoter sequences in plants.

Glycoconjugates on the surface of spores of the pathogenic fungus Phytophthora cinnamomi studied using fluorescence and electron microscopy and flow cytometry

1990 ◽  
Vol 36 (3) ◽  
pp. 183-192 ◽  
Author(s):  
A. R. Hardham ◽  
E. Suzaki
Keyword(s):  
Flow Cytometry ◽  
Plasma Membrane ◽  
Cell Surface ◽  
Phytophthora Cinnamomi ◽  
Pathogenic Fungus ◽  
Fluorescein Isothiocyanate ◽  
Pathogenic Fungi ◽  
Surface Flow ◽  
Soybean Agglutinin ◽  
Binding Material

Glycoconjugates on the surface of zoospores and cysts of the pathogenic fungus Phytophthora cinnamomi have been studied using fluorescein isothiocyanate labelled lectins for fluorescence microscopy and flow cytometry, and ferritin- and gold-labelled lectins for ultrastructural analysis. Of the five lectins used, only concanavalin A (ConA) binds to the surface of the zoospores, including the flagella and water expulsion vacuole. This suggests that of accessible saccharides, glucosyl or mannosyl residues predominate on the outer surface of the zoospore plasma membrane. Early in encystment, a system of flat disc-like cisternae, which underlie the zoospore plasma membrane, vesiculate. These and other small peripheral vesicles quickly disappear. After the induction of encystment, ConA is no longer localised close to the plasma membrane but binds to material loosely associated with the cell surface. Quantitative measurements by flow cytometry indicate that the ConA-binding material is gradually lost from the cell surface. The cyst wall is weakly labelled, but the site of germ tube emergence stains intensely. During the first 2 min after the induction of encystment, material that binds soybean agglutinin, Helix pommatia agglutinin, and peanut agglutinin appears on the surface of the fungal cells. The distribution of this material, rich in galactosyl or N-acetyl-D-galactosaminosyl residues, is initially patchy, but by 5 min the material evenly coats most of the cell surface. Labelling of zoospores in which intracellular sites are accessible indicates that the soybean agglutinin binding material is stored in vesicles that lie beneath the plasma membrane. Quantitation of soybean agglutinin labelling shows that maximum binding occurs 2–3 min after the induction of encystment. Key words: cell surface, flow cytometry, lectins, pathogenic fungi, Phytophthora cinnamomi.

scholarly journals Insect herbivory facilitates the establishment of an invasive plant pathogen

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Martin M. Gossner ◽  
Ludwig Beenken ◽  
Kirstin Arend ◽  
Dominik Begerow ◽  
Derek Peršoh
Keyword(s):  
Invasive Plant ◽  
Pathogenic Fungus ◽  
Feeding Activity ◽  
Insect Herbivory ◽  
Forest Health ◽  
Mechanical Damage ◽  
Pathogenic Fungi ◽  
Fungal Colonization ◽  
Feeding Damage ◽  
The Impact

AbstractPlants can be severely affected by insect herbivores and phytopathogenic fungi, but interactions between these plant antagonists are poorly understood. We analysed the impact of feeding damage by the abundant herbivore Orchestes fagi on infection rates of beech (Fagus sylvatica) leaves with Petrakia liobae, an invasive plant pathogenic fungus. The fungus was not detected in hibernating beetles, indicating that O. fagi does not serve as vector for P. liobae, at least not between growing seasons. Abundance of the fungus in beech leaves increased with feeding damage of the beetle and this relationship was stronger for sun-exposed than for shaded leaves. A laboratory experiment revealed sun-exposed leaves to have thicker cell walls and to be more resistant to pathogen infection than shaded leaves. Mechanical damage significantly increased frequency and size of necroses in the sun, but not in shade leaves. Our findings indicate that feeding damage of adult beetles provides entry ports for fungal colonization by removal of physical barriers and thus promotes infection success by pathogenic fungi. Feeding activity by larvae probably provides additional nutrient sources or eases access to substrates for the necrotrophic fungus. Our study exemplifies that invasive pathogens may benefit from herbivore activity, which may challenge forest health in light of climate change.

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