Double-stranded RNA and associated virulence in South African isolates of Sphaeropsis sapinea

1998 ◽  
Vol 76 (8) ◽  
pp. 1412-1417 ◽  
Author(s):  
Emma T Steenkamp ◽  
Brenda D Wingfield ◽  
Wijnand J Swart ◽  
Michael J Wingfield
Keyword(s):  
Growth Rate ◽  
South African ◽  
Single Species ◽  
Opportunistic Pathogen ◽  
Growth Patterns ◽  
Regular Growth ◽  
Double Stranded Rna ◽  
Sphaeropsis Sapinea ◽  
Pinus Spp

Sphaeropsis sapinea (Fr.) Dyko & Sutton is an opportunistic pathogen of various Pinus spp., causing severe shoot blight and dieback. Some isolates of S. sapinea display characteristics such as reduced virulence, reduced growth rate, lack of pigmentation, altered colony morphology, and suppressed conidiation. South African isolates of S. sapinea displaying a range of growth patterns, including reduced growth rate and atypical morphology, were screened for the presence of double-stranded RNA (dsRNA). They were also tested for relative virulence in pathogenicity tests. Double-stranded RNA was isolated by means of phenol extraction and cellulose chromatographic purification. A single species of dsRNA (± 4.3 kilobase pairs in size) was obtained from two slow-growing isolates and two isolates with more regular growth. The virulence of these dsRNA-containing isolates was tested on mature Pinus patula Schlecht. et Cham. trees. Although reduced virulence was positively correlated with slower growth in vitro, the presence of dsRNA could not be linked to either of these characteristics.Key words: double-stranded RNA, hypovirulence, Sphaeropsis sapinea.

Double-stranded RNA and associated virulence in South African isolates of Sphaeropsis sapinea

1998 ◽  
Vol 76 (8) ◽  
pp. 1412-1417 ◽  
Author(s):  
Emma T. Steenkamp ◽  
Brenda D. Wingfield ◽  
Wijnand J. Swart ◽  
Michael J. Wingfield
Keyword(s):  
South African ◽  
Double Stranded Rna ◽  
Sphaeropsis Sapinea

scholarly journals Genotypic Diversity of Sphaeropsis sapinea from South Africa and Northern Sumatra

Plant Disease ◽  
2000 ◽  
Vol 84 (2) ◽  
pp. 139-142 ◽  
Author(s):  
H. Smith ◽  
M. J. Wingfield ◽  
J. de Wet ◽  
T. A. Coutinho
Keyword(s):  
South Africa ◽  
South African ◽  
Phenotypic Diversity ◽  
Genotypic Diversity ◽  
Population Based ◽  
Pinus Patula ◽  
The South ◽  
South African Population ◽  
Sphaeropsis Sapinea ◽  
Pinus Spp

Sphaeropsis sapinea is the most important pathogen of Pinus spp. in South Africa. The fungus, which reproduces only asexually, occurs on exotic Pinus spp. In this study, the diversity of the S. sapinea population in South Africa was compared with a population from Northern Sumatra. The populations for both countries were obtained from exotic Pinus patula plantations. The phenotypic diversity of these populations was assessed using vegetative compatibility tests. The percent maximum genotypic diversity, based on Stoddart and Taylor's index, for the South African population was 30.5% compared with 1.5% for the Northern Sumatran population. Based on the number of phenotypes, the South African S. sapinea population was significantly more diverse (P = 0.05) than that of the Northern Sumatran population. The results indicate that the population of S. sapinea in South Africa has, in all likelihood, arisen as a result of introductions of the fungus on pine seeds imported from various parts of the world during the last century.

Evaluation of the presence of double-stranded RNA in Ceratocystis ulmi

1985 ◽  
Vol 63 (2) ◽  
pp. 297-300 ◽  
Author(s):  
J. G. Hoch ◽  
S. M. Tavantzis ◽  
R. J. Campana ◽  
S. L. Anagnostakis
Keyword(s):  
Growth Rate ◽  
Mating Type ◽  
Mating Types ◽  
Double Stranded Rna ◽  
Fast Growing ◽  
Molecular Weights ◽  
Clear Association ◽  
Dsrna Species

Nineteen cultures of Ceratocystis ulmi were classified by mating type and growth rate in vitro. Eleven of the cultures contained double-stranded RNA (dsRNA) with 52% of the segments having molecular weights (MWs) ranging from 1.5 × 106 to 2.0 × 106. Eight of 11 fast-growing (aggressive) isolates contained one to five dsRNA segments with MWs ranging from 0.6 × 106 to 3.1 × 106, whereas 3 of 8 slower growing (nonaggressive) cultures had one or two dsRNA species with MWs ranging from 1.8 × 106 to 2.7 × 106. In addition, cultures with both A and B mating types were found to either contain or lack dsRNA. Thus, there was no clear association between the presence of dsRNA or specific components of dsRNA and aggressiveness or nuclear mating type in the cultures of C. ulmi examined in this study.

In vitro assembly of 2-D crystals from partially purified EA1 protein secreted by Bacillus anthracis strain Delta Sterne-1

1994 ◽  
Vol 52 ◽  
pp. 276-277
Author(s):  
Mary Beth Downs ◽  
Wilson Ribot ◽  
Joseph W. Farchaus
Keyword(s):  
Cell Wall ◽  
Molecular Sieves ◽  
Cell Envelope ◽  
Single Species ◽  
Supporting Cell ◽  
Surface Layers ◽  
Rabbit Igg ◽  
In Vitro Assembly ◽  
Covalently Linked

Many bacteria possess surface layers (S-layers) that consist of a two-dimensional protein lattice external to the cell envelope. These S-layer arrays are usually composed of a single species of protein or glycoprotein and are not covalently linked to the underlying cell wall. When removed from the cell, S-layer proteins often reassemble into a lattice identical to that found on the cell, even without supporting cell wall fragments. S-layers exist at the interface between the cell and its environment and probably serve as molecular sieves that exclude destructive macromolecules while allowing passage of small nutrients and secreted proteins. Some S-layers are refractory to ingestion by macrophages and, generally, bacteria are more virulent when S-layers are present.When grown in rich medium under aerobic conditions, B. anthracis strain Delta Sterne-1 secretes large amounts of a proteinaceous extractable antigen 1 (EA1) into the growth medium. Immunocytochemistry with rabbit polyclonal anti-EAl antibody made against the secreted protein and gold-conjugated goat anti-rabbit IgG showed that EAI was localized at the cell surface (fig 1), which suggests its role as an S-layer protein.

In vitro determination of the skin anti-aging potential of eleven South African plants

Planta Medica ◽  
2013 ◽  
Vol 79 (13) ◽  
Author(s):  
GN Ndlovu ◽  
G Fouche ◽  
W Cordier ◽  
V Steenkamp ◽  
M Tselanyane
Keyword(s):  
South African ◽  
South African Plants ◽  
African Plants

The In Vitro Antibiofilm Activity of Water Leaf Extract of Papaya (Carica papaya L.) against Pseudomonas aeruginosa

2017 ◽  
Vol 2 (3) ◽  
pp. 150-163
Author(s):  
Ekajayanti Kining ◽  
Syamsul Falah ◽  
Novik Nurhidayat
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Contact Time ◽  
Cell Attachment ◽  
Water Extract ◽  
Opportunistic Pathogen ◽  
Bacterial Biofilm ◽  
Antibiofilm Activity ◽  
Bacterial Survival ◽  
Optimum Conditions

Pseudomonas aeruginosa is one of opportunistic pathogen forming bacterial biofilm. The biofilm sustains the bacterial survival and infections. This study aimed to assess the activity of water extract of papaya leaves on inhibition of cells attachment, growth and degradation of the biofilm using crystal violet (CV) biofilm assay. Research results showed that water extract of papaya leaves contains alkaloids, tanins, flavonoids, and steroids/terpenoids and showed antibacterial activity and antibiofilm against P. aeruginosa. Addition of extract can inhibit the cell attachment and was able to degrade the biofilm of 40.92% and 48.058% respectively at optimum conditions: extract concentration of 25% (v/v), temperature 37.5 °C and contact time 45 minutes. With a concentration of 25% (v/v), temperature of 50 °C and the contact time of 3 days, extract of papaya leaves can inhibit the growth of biofilms of 39.837% v/v.

scholarly journals In vitro Translation of the Double-stranded RNA Genome from Beet Cryptic Virus 1

1987 ◽  
Vol 68 (5) ◽  
pp. 1417-1422 ◽  
Author(s):  
G. P. Accotto ◽  
M. J. Brisco ◽  
R. Hull
Keyword(s):  
In Vitro Translation ◽  
Double Stranded Rna ◽  
Cryptic Virus ◽  
Rna Genome

scholarly journals In Vitro Model Systems for Exploring Oral Biofilms: From Single‐Species Populations to Complex Multi‐Species Communities

2021 ◽  
Author(s):  
Ting L. Luo ◽  
Michael E. Vanek ◽  
Carlos Gonzalez‐Cabezas ◽  
Carl F. Marrs ◽  
Betsy Foxman ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Single Species ◽  
Model Systems ◽  
Oral Biofilms ◽  
Vitro Model

scholarly journals RNA Helicase A Regulates the Replication of RNA Viruses

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 361
Author(s):  
Rui-Zhu Shi ◽  
Yuan-Qing Pan ◽  
Li Xing
Keyword(s):  
Virus Replication ◽  
Rna Binding ◽  
Rna Viruses ◽  
Rna Helicase ◽  
Rna Helicase A ◽  
Double Stranded Rna ◽  
Binding Domains ◽  
N Terminus

The RNA helicase A (RHA) is a member of DExH-box helicases and characterized by two double-stranded RNA binding domains at the N-terminus. RHA unwinds double-stranded RNA in vitro and is involved in RNA metabolisms in the cell. RHA is also hijacked by a variety of RNA viruses to facilitate virus replication. Herein, this review will provide an overview of the role of RHA in the replication of RNA viruses.

scholarly journals Topical Application of Double-Stranded RNA Targeting 2b and CP Genes of Cucumber mosaic virus Protects Plants against Local and Systemic Viral Infection

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 963
Author(s):  
Maria C. Holeva ◽  
Athanasios Sklavounos ◽  
Rajendran Rajeswaran ◽  
Mikhail M. Pooggin ◽  
Andreas E. Voloudakis
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Topical Application ◽  
Plant Virus ◽  
Plant Protection ◽  
Post Inoculation ◽  
Tobacco Plants ◽  
Double Stranded Rna

Cucumber mosaic virus (CMV) is a destructive plant virus with worldwide distribution and the broadest host range of any known plant virus, as well as a model plant virus for understanding plant–virus interactions. Since the discovery of RNA interference (RNAi) as a major antiviral defense, RNAi-based technologies have been developed for plant protection against viral diseases. In plants and animals, a key trigger of RNAi is double-stranded RNA (dsRNA) processed by Dicer and Dicer-like (DCL) family proteins in small interfering RNAs (siRNAs). In the present study, dsRNAs for coat protein (CP) and 2b genes of CMV were produced in vitro and in vivo and applied onto tobacco plants representing a systemic solanaceous host as well as on a local host plant Chenopodium quinoa. Both dsRNA treatments protected plants from local and systemic infection with CMV, but not against infection with unrelated viruses, confirming sequence specificity of antiviral RNAi. Antiviral RNAi was effective when dsRNAs were applied simultaneously with or four days prior to CMV inoculation, but not four days post inoculation. In vivo-produced dsRNAs were more effective than the in vitro-produced; in treatments with in vivo dsRNAs, dsRNA-CP was more effective than dsRNA-2b, while the effects were opposite with in vitro dsRNAs. Illumina sequencing of small RNAs from in vivo dsRNA-CP treated and non-treated tobacco plants revealed that interference with CMV infection in systemic leaves coincides with strongly reduced accumulation of virus-derived 21- and 22-nucleotide (nt) siRNAs, likely generated by tobacco DCL4 and DCL2, respectively. While the 21-nt class of viral siRNAs was predominant in non-treated plants, 21-nt and 22-nt classes accumulated at almost equal (but low) levels in dsRNA treated plants, suggesting that dsRNA treatment may boost DCL2 activity. Taken together, our findings confirm the efficacy of topical application of dsRNA for plant protection against viruses and shed more light on the mechanism of antiviral RNAi.

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