scholarly journals The innate immunity protein C1QBP functions as a negative regulator of circulative transmission of Potato leafroll virus by aphids

2020 ◽  
Author(s):  
Stacy L. DeBlasio ◽  
Jennifer Wilson ◽  
Cecilia Tamborindeguy ◽  
Richard S. Johnson ◽  
Patricia V. Pinheiro ◽  
...  
Keyword(s):  
Innate Immunity ◽  
High Resolution Mass Spectrometry ◽  
Affinity Purification ◽  
Plant Viruses ◽  
Potato Leafroll Virus ◽  
Negative Regulator ◽  
Virus Protein ◽  
Insect Vector ◽  
Immunity Protein ◽  
Leafroll Virus

ABSTRACTThe vast majority of plant viruses are transmitted by insect vectors with many crucial aspects of the transmission process being mediated by key protein-protein interactions. Yet, very few vector proteins interacting with virus have been identified and functionally characterized. Potato leafroll virus (PLRV) is transmitted most effectively by Myzus persicae, the green peach aphid, in a circulative, non-propagative manner. Using an affinity purification strategy coupled to high-resolution mass spectrometry (AP-MS), we identified 11 proteins from M. persicae displaying high probability of interaction with PLRV and an additional 23 vector proteins with medium confidence interaction scores. Two of these proteins were confirmed to directly interact with the structural proteins of PLRV and other luteovirid species via yeast two-hybrid with an additional vector protein displaying binding specificity. Immunolocalization of one of these direct PLRV-interacting proteins, an orthologue of the human innate immunity protein complement component 1 Q subcomponent-binding protein (C1QBP), shows that MpC1QBP partially co-localizes with PLRV within cytoplasmic puncta and along the periphery of aphid gut epithelial cells. Chemical inhibition of C1QBP in the aphid leads to increased PLRV acquisition and subsequently increased titer in inoculated plants, supporting the role of C1QBP as a negative regulator of PLRV accumulation in M. persicae. We hypothesize that the innate immune function of C1QBP is conserved in aphids and represents the first instance of aphids mounting an immune response to a non-propagative plant virus. This study presents the first use of AP-MS for the in vivo isolation of functionally relevant insect vector-virus protein complexes.

scholarly journals Inhibition of potato leafroll virus multiplication and systemic translocation by siRNA constructs against putative ATPase fold of movement protein

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Priyanka Kumari ◽  
Jitesh Kumar ◽  
Ravi Ranjan Kumar ◽  
Mohammad Ansar ◽  
Kumari Rajani ◽  
...  
Keyword(s):  
Gene Expression ◽  
Movement Protein ◽  
Control Plant ◽  
Plant Viruses ◽  
Potato Leafroll Virus ◽  
Plant Diseases ◽  
World Population ◽  
Genome Replication ◽  
Potato Plants ◽  
Leafroll Virus

AbstractViruses cause many severe plant diseases, resulting in immense losses of crop yield worldwide. Therefore, developing novel approaches to control plant viruses is crucial to meet the demands of a growing world population. Recently, RNA interference (RNAi) has been widely used to develop virus-resistant plants. Once genome replication and assembly of virion particles is completed inside the host plant, mature virions or sometimes naked viral genomes spread cell-to-cell through plasmodesmata by interacting with the virus-encoded movement protein (MP). We used the RNAi approach to suppress MP gene expression, which in turn prevented potato leafroll virus (PLRV) systemic infection in Solanum tuberosum cv. Khufri Ashoka. Potato plants agroinfiltrated with MP siRNA constructs exhibited no rolling symptoms upon PLRV infection, indicating that the silencing of MP gene expression is an efficient method for generating PLRV-resistant potato plants. Further, we identified novel ATPase motifs in MP that may be involved in DNA binding and translocation through plasmodesmata. We also showed that the ATPase activity of MP was stimulated in the presence of DNA/RNA. Overall, our findings provide a robust technology to generate PLRV-resistant potato plants, which can be extended to other species. Moreover, this approach also contributes to the study of genome translocation mechanisms of plant viruses.

scholarly journals Potato virus Y and Potato leafroll virus management under climate change in sub-Saharan Africa

2020 ◽  
Vol 116 (11/12) ◽  
Author(s):  
Kerstin Krüger ◽  
Jacquie E. van der Waals
Keyword(s):  
Potato Virus ◽  
Potato Virus Y ◽  
Production Systems ◽  
Plant Viruses ◽  
Potato Leafroll Virus ◽  
Climatic Conditions ◽  
Cultural Control ◽  
Sub Saharan Africa ◽  
Sub Saharan ◽  
Leafroll Virus

Potato has increased in importance as a staple food in sub-Saharan Africa, where its production is faced with a multitude of challenges, including plant disease development and spread under changing climatic conditions. The economically most important plant viruses affecting potatoes globally are Potato virus Y (PVY) and Potato leafroll virus (PLRV). Disease management relies mostly on the use of insecticides, cultural control and seed certification schemes. A major obstacle in many sub-Saharan Africa countries is the availability of disease-free quality seed potatoes. Establishment and implementation of quality control through specialised seed production systems and certification schemes is critical to improve seed potato quality and reduce PVY and PLRV sources. Seed could be further improved by breeding virus-resistant varieties adapted to different environmental conditions combined with management measures tailored for smallholder or commercial farmers to specific agricultural requirements. Innovative technologies – including more sensitive testing, remote sensing, machine learning and predictive models – provide new tools for the management of PVY and PLRV, but require support for adoption and implementation in sub-Saharan Africa.

Potato leafroll virus protein P1 contains a serine proteinase domain

Microbiology ◽  
2000 ◽  
Vol 81 (7) ◽  
pp. 1857-1864 ◽  
Author(s):  
X. Li ◽  
M. D. Ryan ◽  
J. W. Lamb
Keyword(s):  
Insect Cells ◽  
Plant Cells ◽  
Serine Proteinase ◽  
Potato Leafroll Virus ◽  
Autographa Californica ◽  
Virus Protein ◽  
Conserved Residues ◽  
Intermolecular Reaction ◽  
Polyhedrin Promoter ◽  
Leafroll Virus

The multi-domain potato leafroll virus replicase protein P1 was expressed in insect cells from the polyhedrin promoter of Autographa californica nucleopolyhedrovirus. Using antisera raised against P1, it was shown that P1 was cleaved near the VPg in insect cells in a manner similar to that in plant cells, to produce a ∼27 kDa C-terminal fragment. Furthermore, it was shown that the proposed serine proteinase-like domain within P1 is responsible for this processing and that this can occur in a trans (intermolecular) reaction. Four conserved residues within the serine proteinase domain that are essential for catalysis have been identified, consistent with the proposal that this domain comprises a serine proteinase.

scholarly journals Fusion Proteins of Single-Chain Variable Fragments Derived from Phage Display Libraries Are Effective Reagents for Routine Diagnosis of Potato Leafroll Virus Infection in Potato

1999 ◽  
Vol 89 (11) ◽  
pp. 1015-1021 ◽  
Author(s):  
R. L. Toth ◽  
K. Harper ◽  
M. A. Mayo ◽  
L. Torrance
Keyword(s):  
Phage Display ◽  
Polyclonal Antibody ◽  
Fusion Proteins ◽  
Plant Viruses ◽  
Potato Leafroll Virus ◽  
Diagnostic Tools ◽  
Single Chain ◽  
Antibody Preparation ◽  
Phage Display Libraries ◽  
Leafroll Virus

A panel of 11 different single-chain variable fragment antibodies (scFv) that bind to potato leafroll virus (PLRV) has been studied to assess each one's suitability as practical diagnostic tools. The scFv, previously obtained from naive phage display libraries, were expressed in Escherichia coli as fusion proteins. The fusion proteins comprised scFv joined to either the human light chain kappa constant domain (CL), an amphipathic helix (Zip), a combination of CL and Zip, or alkaline phosphatase (AP/S). The fusion proteins were tested for their ability to detect, or trap on enzymelinked immunosorbent assay (ELISA) plates, PLRV in extracts of infected potato leaves. The tests done with the different scFv fusion proteins were compared with a standard triple-antibody sandwich (TAS)-ELISA that employs a rabbit polyclonal antibody preparation to coat microtiter plates and a monoclonal antibody, SCR3, to detect PLRV. Of 11 scFvCL fusion proteins, 7 detected PLRV as readily as SCR3 when used as detecting antibodies in TAS-ELISA. The limit of detection of purified PLRV for the different scFvCL fusion proteins ranged from 250 to 5 ng/ml; that for SCR3 is 5 ng/ml. Of the 11 scFv, 4 cross-reacted with some other luteoviruses. Several scFvCL and scFvCLZip fusion proteins trapped PLRV from extracts of infected potato leaves as effectively as the polyclonal antibody preparation. Four scFv fusion proteins were used in a stem print assay to detect PLRV, and the results were similar to those obtained in tests using SCR3. The scFvCL fusion proteins retained activity for at least 6 months at 4°C, and all scFv fusion proteins were fully active on reconstitution after lyophilization. A fully recombinant ELISA was devised that detected PLRV in extracts of infected potato, with results comparable to those obtained using the standard TAS-ELISA. The advantages of using scFv fusion proteins for the routine detection of plant viruses include the ability to produce large quantities of reagents cheaply in bacterial fermenters and to incorporate them into standardized tests.

scholarly journals The Interaction Dynamics of Two Potato Leafroll Virus Movement Proteins Affects Their Localization to the Outer Membranes of Mitochondria and Plastids

Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 585 ◽  
Author(s):  
Stacy DeBlasio ◽  
Yi Xu ◽  
Richard Johnson ◽  
Ana Rebelo ◽  
Michael MacCoss ◽  
...  
Keyword(s):  
Mutational Analysis ◽  
Affinity Purification ◽  
Potato Leafroll Virus ◽  
Structural Proteins ◽  
Mitochondrial Outer Membrane ◽  
Virus Movement ◽  
Cell Periphery ◽  
Movement Proteins ◽  
C Terminus ◽  
Leafroll Virus

The Luteoviridae is an agriculturally important family of viruses whose replication and transport are restricted to plant phloem. Their genomes encode for four proteins that regulate viral movement. These include two structural proteins that make up the capsid and two non-structural proteins known as P3a and P17. Little is known about how these proteins interact with each other and the host to coordinate virus movement within and between cells. We used quantitative, affinity purification-mass spectrometry to show that the P3a protein of Potato leafroll virus complexes with virus and that this interaction is partially dependent on P17. Bimolecular complementation assays (BiFC) were used to validate that P3a and P17 self-interact as well as directly interact with each other. Co-localization with fluorescent-based organelle markers demonstrates that P3a directs P17 to the mitochondrial outer membrane while P17 regulates the localization of the P3a-P17 heterodimer to plastids. Residues in the C-terminus of P3a were shown to regulate P3a association with host mitochondria by using mutational analysis and also varying BiFC tag orientation. Collectively, our work reveals that the PLRV movement proteins play a game of intracellular hopscotch along host organelles to transport the virus to the cell periphery.

scholarly journals Drebrin restricts rotavirus entry by inhibiting dynamin-mediated endocytosis

2017 ◽  
Vol 114 (18) ◽  
pp. E3642-E3651 ◽  
Author(s):  
Bin Li ◽  
Siyuan Ding ◽  
Ningguo Feng ◽  
Nancie Mooney ◽  
Yaw Shin Ooi ◽  
...  
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Affinity Purification ◽  
Negative Regulator ◽  
Host Cells ◽  
Actin Binding ◽  
Target Cells ◽  
Host Proteins ◽  
Severe Diarrhea ◽  
Stool Samples

Despite the wide administration of several effective vaccines, rotavirus (RV) remains the single most important etiological agent of severe diarrhea in infants and young children worldwide, with an annual mortality of over 200,000 people. RV attachment and internalization into target cells is mediated by its outer capsid protein VP4. To better understand the molecular details of RV entry, we performed tandem affinity purification coupled with high-resolution mass spectrometry to map the host proteins that interact with VP4. We identified an actin-binding protein, drebrin (DBN1), that coprecipitates and colocalizes with VP4 during RV infection. Importantly, blocking DBN1 function by siRNA silencing, CRISPR knockout (KO), or chemical inhibition significantly increased host cell susceptibility to RV infection.Dbn1KO mice exhibited higher incidence of diarrhea and more viral antigen shedding in their stool samples compared with the wild-type littermates. In addition, we found that uptake of other dynamin-dependent cargos, including transferrin, cholera toxin, and multiple viruses, was also enhanced in DBN1-deficient cells. Inhibition of cortactin or dynamin-2 abrogated the increased virus entry observed in DBN1-deficient cells, suggesting that DBN1 suppresses dynamin-mediated endocytosis via interaction with cortactin. Our study unveiled an unexpected role of DBN1 in restricting the entry of RV and other viruses into host cells and more broadly to function as a crucial negative regulator of diverse dynamin-dependent endocytic pathways.

scholarly journals Elements regulating Potato leafroll virus sgRNA1 translation are located within the coding sequences of the coat protein and read-through domain.

1970 ◽  
Vol 56 (4) ◽  
Author(s):  
Adrianna Łoniewska-Lwowska ◽  
Sylwia Chełstowska ◽  
Włodzimierz Zagórski-Ostoja ◽  
Andrzej Pałucha
Keyword(s):  
Coat Protein ◽  
Regulatory Elements ◽  
Plant Viruses ◽  
Potato Leafroll Virus ◽  
In Vitro Translation ◽  
Translation Efficiency ◽  
Coding Region ◽  
Reticulocyte Lysate ◽  
Leafroll Virus

Translation of viral proteins from subgenomic RNAs (sgRNAs) is a common strategy among positive-stranded RNA viruses. Unlike host mRNA, sgRNA of Potato leafroll virus (PLRV) does not possess a cap at its 5' end nor a poly(A) tail at the 3' terminus, both of which are known to be crucial for translation of RNA in eukaryotic cells. Here, we demonstrate, that in wheat germ extract (WGE) truncation of the sgRNA1 5' UTR increases translation efficiency, as it has previously been observed in rabbit reticulocyte lysate (RRL), whereas removal of the 3' UTR does not affect translation. We also describe two regulatory elements located within the coding sequence of the coat protein (CP) gene and its read-through domain (RTD) and are responsible for regulation of in vitro translation of the PLRV sgRNA1. The frst element is composed of the purine sequence AAAGGAAA located between the AUG codons of the CP and 17K genes. Deletion of this domain or its substitution by pyrimidines reduced by half the translation of both genes, whereas deletion of the RTD resulted in a 3.6-fold reduction in translation efficiency. This is the first report of translation regulatory elements of plant viruses located within a coding region.

Green peach aphid and potato leafroll virus: transmission and control

2020 ◽  
Author(s):  
R.A. Bagrov ◽  
◽  
V.I. Leunov
Keyword(s):  
Myzus Persicae ◽  
Green Peach Aphid ◽  
Virus Transmission ◽  
Potato Leafroll Virus ◽  
Factors Affecting ◽  
Potato Viruses ◽  
Tuber Necrosis ◽  
Aphid Vectors ◽  
Leafroll Virus ◽  
And Control

The mechanisms of transmission of potato viruses from plants to aphid vectors and from aphids to uninfected plants are described, including the example of the green peach aphid (Myzus persicae, GPA). Factors affecting the spreading of tuber necrosis and its manifestation on plants infected with potato leafroll virus (PLRV) are discussed. Recommendations for PLRV and GPA control in the field are given.

scholarly journals Direct and Indirect Effect via Endophytism of Entomopathogenic Fungi on the Fitness of Myzus persicae and Its Ability to Spread PLRV on Tobacco

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 89
Author(s):  
Junior Corneille Fingu-Mabola ◽  
Thomas Bawin ◽  
Frédéric Francis
Keyword(s):  
Entomopathogenic Fungi ◽  
Myzus Persicae ◽  
Foliar Application ◽  
Plant Viruses ◽  
High Yield ◽  
Tobacco Plants ◽  
Metarhizium Acridum ◽  
Nicotiana Tabacum L ◽  
Leafroll Virus ◽  
Diverse Plant

Aphids are major crop pests that transmit more than half of all insect-vectored plant viruses responsible for high yield losses worldwide. Entomopathogenic fungi (EPF) are biological control agents mainly used by foliar application to control herbivores, including sap-sucking pests such as aphids. Their ability to colonize plant tissues and to interact with diverse plant pathogenic microorganisms have been reported. In our study, we evaluated the effectiveness of Beauveria bassiana ((Balsamo-Crivelli) Vuillemin) directly applied by contact or/and indirectly via endophytism in tobacco plants (Nicotiana tabacum L.) against the virus vector Myzus persicae (Sulzer) carrying the Potato leafroll virus (PLRV) or not. We found that both contact treatment and endophytic colonization of leaves significantly increased aphid mortality and decreased the fecundity rate when compared to control plants. In addition, on fungal-colonized leaves, viruliferous aphids were more negatively impacted than virus-free ones and nymph mortality was significantly higher than on fungal-free plants. Furthermore, we assessed PLRV transmission by M. persicae on tobacco plants inoculated with either B. bassiana or Metarhizium acridum ((Driver and Milner) JF Bischoff, Rehner, and Humber) as source or/and recipient plants. Myzus persicae was found to acquire and transmit PLRV regardless of the treatment. Nevertheless, the infection rate of endophytically colonized plants was lower at a seven-day incubation period and had increased to almost 100% after fifteen days. These results suggest that B. bassiana is effective against aphids, both by contact and via endophytism, and both B. bassiana and M. acridum delayed PLRV infection in tobacco.

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