Electrical penetration graphs from Cicadulina mbila on maize, the fine structure of its stylet pathways and consequences for virus transmission efficiency

The genetic control of resistance to Cucurbit aphid-borne yellows virus (CABYV; genus Polerovirus, family Luteoviridae) in the TGR-1551 melon accession was studied through agroinoculation of a genetic family obtained from the cross between this accession and the susceptible Spanish cultivar ‘Bola de Oro’. Segregation analyses were consistent with the hypothesis that one dominant gene and at least two more modifier genes confer resistance; one of these additional genes is likely present in the susceptible parent ‘Bola de Oro’. Local and systemic accumulation of the virus was analyzed in a time course experiment, showing that TGR-1551 resistance was expressed systemically as a significant reduction of virus accumulation compared with susceptible controls, but not locally in agroinoculated cotyledons. In aphid transmission experiments, CABYV inoculation by aphids was significantly reduced in TGR-1551 plants, although the virus was acquired at a similar rate from TGR-1551 as from susceptible plants. Results of feeding behavior studies using the DC electrical penetration graph technique suggested that viruliferous aphids can salivate and feed from the phloem of TGR-1551 plants and that the observed reduction in virus transmission efficiency is not related to reduced salivation by Aphis gossypii in phloem sieve elements. Since the virus is able to accumulate to normal levels in agroinoculated tissues, our results suggest that resistance of TGR-1551 plants to CABYV is related to impairment of virus movement or translocation after it reaches the phloem sieve elements.

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Characterization of a Potyvirus Infecting Sunflower in Argentina

Plant Disease ◽

10.1094/pdis.1998.82.5.470 ◽

1998 ◽

Vol 82 (5) ◽

pp. 470-474 ◽

Cited By ~ 23

Author(s):

G. Dujovny ◽

T. Usugi ◽

K. Shohara ◽

S. Lenardon

Keyword(s):

Capsid Protein ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Virus Transmission ◽

Transmission Efficiency ◽

Polyclonal Antiserum ◽

Dot Blot ◽

Chlorotic Mottling ◽

Ultrathin Sections

A virus causing chlorotic mottling symptoms on sunflower was found in various locations in Argentina. Symptoms were small chlorotic spots, yellow blotches on leaves, and plant stunting. Virus transmission efficiency by mechanical inoculation was 73 to 100%, and by Myzus persicae was 31 to 49%. The host range included members of the Amaranthaceae, Asteraceae, Chenopodiaceae, and Solanaceae families. Electron microscopy of leaf dips from infected plants revealed flexuous particles 17 nm wide and 770 nm long. Cytoplasmic laminar aggregates and pinwheel inclusions were observed in ultrathin sections. Purified virus preparations analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis resolved a capsid protein of 33 kDa. A monoclonal antibody to aphid-transmitted potyviruses reacted with the capsid protein of this virus. In dot blot immunoassays, a polyclonal antiserum (early bleeding) reacted with infected sunflowers and weakly with Bidens mottle potyvirus, but not with either maize dwarf mosaic potyvirus or potato virus Y. The evidence suggests that a potyvirus is infecting sunflower, and a partial characterization of the causal agent is reported.

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Efficiency of Human Immunodeficiency Virus Transmission Through Injections and Other Medical Procedures Evidence, Estimates, and Unfinished Business

Infection Control and Hospital Epidemiology ◽

10.1086/506408 ◽

2006 ◽

Vol 27 (9) ◽

pp. 944-952 ◽

Cited By ~ 27

Author(s):

David Gisselquist ◽

Garance Upham ◽

John J. Potterat

Keyword(s):

Human Immunodeficiency Virus ◽

Healthcare Workers ◽

Case Control Study ◽

Virus Transmission ◽

Transmission Efficiency ◽

Case Control ◽

Medical Procedures ◽

Unfinished Business ◽

Immunodeficiency Virus ◽

Control Study

Objective.To estimate the transmission efficiency of human immunodeficiency virus (HIV) through medical injections and other invasive procedures.Design.We searched our own files and Medline (from 1966-2004, using the keywords [“iatrogenic” or “nosocomial” or “injections”] and “HIV”) for reports of iatrogenic outbreaks worldwide, except outbreaks traced to receipt of contaminated blood or blood products. We also analyzed information from a case-control study of percutaneous exposures to healthcare workers.Setting.Worldwide healthcare settings.Events.We identified 8 iatrogenic outbreaks that met our study criteria; published information from 4 outbreaks was sufficient to estimate transmission efficiency.Results.From the 4 documented iatrogenic outbreaks, we estimated that 1 iatrogenic infection occurred after 8-52 procedures involving HIV-infected persons. Although only 0.3% of healthcare workers seroconvert after percutaneous exposure, a case-control study reported that deep injuries and other risk factors collectively increased seroconversion risk by as much as 50 times. Laboratory investigations demonstrate HIV survival through time and various rinsing regimens. We estimate that the transmission efficiency in medical settings with no or grossly insufficient efforts to clean equipment ranges from 0.5% to 3% for lower risk procedures (eg, intramuscular injections) and from 10% to 20% or more for high-risk procedures. Efforts to clean equipment, short of sterilization, may cut the transmission efficiency by 0%-100%. Procedures that contaminate multidose vials may accelerate transmission efficiency.Conclusion.To achieve better estimates of the transmission efficiency for a range of medical procedures and settings, investigations of iatrogenic outbreaks should be accorded high priority.

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Co-infection with a wheat rhabdovirus causes a reduction inMal de Río Cuarto virustiter in its planthopper vector

Bulletin of Entomological Research ◽

10.1017/s0007485317000803 ◽

2017 ◽

Vol 108 (2) ◽

pp. 232-240

Author(s):

A.D. Dumón ◽

E.B. Argüello Caro ◽

M.F. Mattio ◽

V. Alemandri ◽

M. del Vas ◽

...

Keyword(s):

Quantitative Polymerase Chain Reaction ◽

Virus Transmission ◽

Polymerase Chain Reaction Analysis ◽

Transmission Efficiency ◽

Insect Vector ◽

Mixed Inoculum ◽

Natural Vector ◽

Mixed Inocula ◽

Virus Interactions ◽

Viral Accumulation

AbstractMal de Río Cuarto virus(MRCV,Fijivirus,Reoviridae) causes one of the most important diseases in maize (Zea maysL.) in Argentina and has been detected in mixed infections with a rhabdovirus closely related to Maize yellow striate virus. In nature both viruses are able to infect maize and several grasses including wheat, and are transmitted in a persistent propagative manner byDelphacodes kuscheliFennah (Hemiptera: Delphacidae). This work describes the interactions between MRCV and rhabdovirus within their natural vector and the consequences of such co-infection regarding virus transmission and symptom expression. First- and third-instarD. kuschelinymphs were fed on MRCV-infected wheat plants or MRCV-rhabdovirus-infected oat plants, and two latency periods were considered. Transmission efficiency and viral load of MRCV-transmitting and non-transmitting planthoppers were determined by real-time quantitative polymerase chain reaction analysis (RTqPCR). Vector transmission efficiency was related to treatments (life stages at acquisition and latency periods). Nevertheless, no correlation between transmission efficiency and type of inoculum used to infect insects with MRCV was found. Treatment by third-instar nymphs 17 days after Acquisition Access Period was the most efficient for MRCV transmission, regardless of the type of inoculum. Plants co-infected with MRCV and rhabdovirus showed the typical MRCV symptoms earlier than plants singly infected with MRCV. The transmitting planthoppers showed significantly higher MRCV titers than non-transmitting insects fed on single or mixed inocula, confirming that successful MRCV transmission is positively associated with viral accumulation in the insect. Furthermore, MRCV viral titers were higher in transmitting planthoppers that acquired this virus from a single inoculum than in those that acquired the virus from a mixed inoculum, indicating that the presence of the rhabdovirus somehow impaired MRCV replication and/or acquisition. This is the first study about interactions between MRCV and a rhabdovirus closely related to Maize yellow striate virus in this insect vector (D. kuscheli), and contributes to a better understanding of planthopper–virus interactions and their epidemiological implications.

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Silver Nanoparticles as A Highly Viricidal Agent to Deter Plant-Infecting Viruses and Disrupt their Acquisition and Transmissibility by Vector Aphid

10.21203/rs.3.rs-422790/v1 ◽

2021 ◽

Author(s):

Ahmed El Gamal ◽

Mohamed Reda Tohamy ◽

Mohamed Ibrahim Abou-Zaid ◽

Mahmoud Mohamed Atia ◽

Tarek El Sayed ◽

...

Keyword(s):

Silver Nanoparticles ◽

Plant Pathogens ◽

Virus Transmission ◽

Transmission Efficiency ◽

Yellow Mosaic Virus ◽

Virus Inoculation ◽

Virus Acquisition ◽

Disease Occurrence ◽

Bean Plants ◽

Pathogenesis Related Gene

Abstract Silver nanoparticles (AgNPs) are a potentially effective tool for deterring viral plant pathogens. This study was carried out to evaluate the efficacy of AgNPs to defeat Bean yellow mosaic virus (BYMV) on faba bean plants from the host, virus and vector aphid tripartite interactions side. The antiviral capabilities were evaluated during a foliar protective and curative scheme. Furthermore, the efficiency of AgNPs on virus acquisition and transmission by its vector aphid was investigated. Results indicated that the AgNPs had greatly exhibited curative viricidal activities for inactivation BYMV when applied 48 h post-virus inoculation. The disease occurrence was entirely inhibited with AgNPs rate as low as 100 mg.l− 1, while the infectivity was completely arrested when plants were preventively exposed to 200 mg.l− 1 24 h pre-virus inoculation. AgNPs proved high bio-reactivity by binding to viral particles, suppressing their replication and accumulation within the plant tissues. Moreover, it was noticeably showed to upregulate the pathogenesis-related gene (PR-1) and promote the defense-related enzymes and protein profiles in treated plants irrespective of concentration. Exposure of aphids to AgNPs-treated plants before virus acquisition excitingly reduced the BYMV acquisition and transmission efficiency by 40.65% up to 100 % 24 h post-application and the virus acquisition was affected for 10 days by 6.89 Up to 79.64 % depending on the AgNPs rate. These results concluded that the AgNPs have a high curing viricidal activity by targeting the virus envelop, and more excitingly it can affect the virus-vector combination, suggesting that it may contribute to alleviating the natural disease occurrence and virus transmission under field conditions. Therefore, according to the available literature, this study provides the first report on the deterring activity of nanomaterials against plant virus acquisition and transmission by its vector insects.

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The passage of Potato leafroll virus through Myzus persicae gut membrane regulates transmission efficiency

Journal of General Virology ◽

10.1099/0022-1317-82-1-17 ◽

2001 ◽

Vol 82 (1) ◽

pp. 17-23 ◽

Cited By ~ 31

Author(s):

J. Rouzé-Jouan ◽

L. Terradot ◽

F. Pasquer ◽

S. Tanguy ◽

D. Giblot Ducray-Bourdin

Keyword(s):

Amino Acid ◽

Coat Protein ◽

Myzus Persicae ◽

Virus Transmission ◽

Transmission Efficiency ◽

Potato Leafroll Virus ◽

Transmission Process ◽

Leafroll Virus ◽

Readthrough Protein

Potato leafroll virus (PLRV) is transmitted by aphids in a persistent manner. Although virus circulation within the aphid leading to transmission has been well characterized, the mechanisms involved in virus recognition at aphid membranes are still poorly understood. One isolate in our collection (PLRV-14.2) has been shown to be non- or only poorly transmitted by some clones of aphids belonging to the Myzus persicae complex. To determine where the transmission process was blocked within the aphid, three virus transmission procedures were used. PLRV-14.2 could not be transmitted, or was only very poorly transmitted, after acquisition from infected plants or from purified preparations. In contrast, it could be transmitted with more than 70% efficiency when microinjected. Therefore, it is concluded that the gut membrane was a barrier regulating passage of PLRV particles from the gut lumen into the haemocoel of M. persicae. Comparison of coat protein (CP) and readthrough protein (RTP) sequences between poorly and readily transmissible isolates showed that PLRV-14.2 differed from other PLRV isolates by amino acid changes in both of these proteins. It is hypothesized that at least some of the changes found in CP and/or RTP reduced virus recognition by aphid gut receptors, resulting in reduced acquisition and subsequent transmission of PLRV-14.2.

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Transmission of Begomoviruses and Other Whitefly-Borne Viruses: Dependence on the Vector Species

Phytopathology ◽

10.1094/phyto-07-19-0273-fi ◽

2020 ◽

Vol 110 (1) ◽

pp. 10-17 ◽

Cited By ~ 14

Author(s):

Elvira Fiallo-Olivé ◽

Li-Long Pan ◽

Shu-Sheng Liu ◽

Jesús Navas-Castillo

Keyword(s):

Cryptic Species ◽

Virus Transmission ◽

Plant Viruses ◽

Transmission Efficiency ◽

Emerging Diseases ◽

Future Research ◽

Factors Affecting ◽

Biological Vector ◽

Available Information ◽

Phloem Feeding

Most plant viruses require a biological vector to spread from plant to plant in nature. Among biological vectors for plant viruses, hemipteroid insects are the most common, including phloem-feeding aphids, whiteflies, mealybugs, planthoppers, and leafhoppers. A majority of the emerging diseases challenging agriculture worldwide are insect borne, with those transmitted by whiteflies (Hemiptera: Aleyrodidae) topping the list. Most damaging whitefly-transmitted viruses include begomoviruses (Geminiviridae), criniviruses (Closteroviridae), and torradoviruses (Secoviridae). Among the whitefly vectors, Bemisia tabaci, now recognized as a complex of cryptic species, is the most harmful in terms of virus transmission. Here, we review the available information on the differential transmission efficiency of begomoviruses and other whitefly-borne viruses by different species of whiteflies, including the cryptic species of the B. tabaci complex. In addition, we summarize the factors affecting transmission of viruses by whiteflies and point out some future research prospects.

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Bacterial Endosymbiont Diversity among Bemisia tabaci (Hemiptera: Aleyrodidae) Populations in Florida

Insects ◽

10.3390/insects11030179 ◽

2020 ◽

Vol 11 (3) ◽

pp. 179 ◽

Cited By ~ 1

Author(s):

Bruno Rossitto De Marchi ◽

Hugh A. Smith

Keyword(s):

Phylogenetic Analysis ◽

Bemisia Tabaci ◽

Virus Transmission ◽

Plant Viruses ◽

Transmission Efficiency ◽

South Florida ◽

Sweetpotato Whitefly ◽

Low Genetic Diversity ◽

Bacterial Endosymbionts

The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is a pest of many economically important agricultural crops and a vector of plant viruses. Bemisia tabaci harbors facultative endosymbiont species that have been implicated in pest status, including tolerance to insecticides, virus transmission efficiency and tolerance to high-temperatures. The facultative endosymbionts reported in B. tabaci include Arsenophonus, Hamiltonella, Wolbachia, Cardinium, Fritschea and Rickettsia. We collected whitefly populations from weed and crop hosts in south Florida and identified the whitefly species as well as the facultative endosymbionts present in these populations by molecular analysis. In addition, a phylogenetic analysis of whiteflies and their endosymbionts was performed. The only facultative endosymbionts found among the B. tabaci populations collected in Florida were Hamiltonella and Rickettsia. The phylogenetic analysis revealed the low genetic diversity of whiteflies and their endosymbionts. Additionally, the phylogenetic tree clustered Rickettsia from Florida in the R1 genetic group. The results will aid to understand the role of the bacterial endosymbionts in the whitefly host.

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