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1.
PLoS Pathog ; 20(4): e1012142, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38574111

RESUMO

RNA viruses and viroids exist and evolve as quasispecies due to error-prone replication. Quasispecies consist of a few dominant master sequences alongside numerous variants that contribute to genetic diversity. Upon environmental changes, certain variants within quasispecies have the potential to become the dominant sequences, leading to the emergence of novel infectious strains. However, the emergence of new infectious variants remains unpredictable. Using mutant pools prepared by saturation mutagenesis of selected stem and loop regions, our study of potato spindle tuber viroid (PSTVd) demonstrates that mutants forming local three-dimensional (3D) structures similar to the wild type (WT) are more likely to accumulate in PSTVd quasispecies. The selection mechanisms underlying this biased accumulation are likely associated with cell-to-cell movement and long-distance trafficking. Moreover, certain trafficking-defective PSTVd mutants can be spread by functional sister genomes in the quasispecies. Our study reveals that the RNA 3D structure of stems and loops constrains the evolution of viroid quasispecies. Mutants with a structure similar to WT have a higher likelihood of being maintained within the quasispecies and can potentially give rise to novel infectious variants. These findings emphasize the potential of targeting RNA 3D structure as a more robust approach to defend against viroid infections.


Assuntos
Vírus de Plantas , Solanum tuberosum , Viroides , Viroides/genética , Solanum tuberosum/genética , RNA Viral/genética , RNA Viral/química , Quase-Espécies , Mutagênese , Doenças das Plantas , Vírus de Plantas/genética
2.
Microb Biotechnol ; 17(4): e14468, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38635158

RESUMO

The sweet potato whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is responsible for significant crop losses and presents one of the greatest challenges for global agricultural pest management. Management of whitefly populations and associated plant viral diseases is hindered by widespread whitefly resistance to chemical insecticides. An alternative control approach involves the use of insect-specific neurotoxins, but these require delivery from the whitefly gut into the haemocoel. Here we demonstrate that the coat protein (CP) of a begomovirus, Tomato yellow leaf curl virus, is sufficient for delivery of fused proteins into the whitefly haemocoel without virion assembly. Following feeding on the recombinant CP-P-mCherry fusion (where -P- is a proline-rich linker), mCherry fluorescence was detected in the dorsal aorta and pericardial cells of the whitefly, but not in those of whitefly fed on negative control treatments, indicating effective CP-mediated delivery of mCherry into the whitefly haemocoel. Significant mortality was observed in whiteflies fed on a fusion of CP-P to the insect-specific neurotoxin Hv1a, but not in whiteflies fed on CP-P fused to a disarmed Hv1a mutant. Begomovirus coat protein - insect neurotoxin fusions hold considerable potential for transgenic resistance to whitefly providing valuable tools for whitefly management.


Assuntos
Hemípteros , Vírus de Plantas , Animais , Neurotoxinas , Agricultura , Fluorescência
3.
Virol J ; 21(1): 86, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622686

RESUMO

BACKGROUND: Viruses have notable effects on agroecosystems, wherein they can adversely affect plant health and cause problems (e.g., increased biosecurity risks and economic losses). However, our knowledge of their diversity and interactions with specific host plants in ecosystems remains limited. To enhance our understanding of the roles that viruses play in agroecosystems, comprehensive analyses of the viromes of a wide range of plants are essential. High-throughput sequencing (HTS) techniques are useful for conducting impartial and unbiased investigations of plant viromes, ultimately forming a basis for generating further biological and ecological insights. This study was conducted to thoroughly characterize the viral community dynamics in individual plants. RESULTS: An HTS-based virome analysis in conjunction with proximity sampling and a tripartite network analysis were performed to investigate the viral diversity in chunkung (Cnidium officinale) plants. We identified 61 distinct chunkung plant-associated viruses (27 DNA and 34 RNA viruses) from 21 known genera and 6 unclassified genera in 14 known viral families. Notably, 12 persistent viruses (7 DNA and 5 RNA viruses) were exclusive to dwarfed chunkung plants. The detection of viruses from the families Partitiviridae, Picobirnaviridae, and Spinareoviridae only in the dwarfed plants suggested that they may contribute to the observed dwarfism. The co-infection of chunkung by multiple viruses is indicative of a dynamic and interactive viral ecosystem with significant sequence variability and evidence of recombination. CONCLUSIONS: We revealed the viral community involved in chunkung. Our findings suggest that chunkung serves as a significant reservoir for a variety of plant viruses. Moreover, the co-infection rate of individual plants was unexpectedly high. Future research will need to elucidate the mechanisms enabling several dozen viruses to co-exist in chunkung. Nevertheless, the important insights into the chunkung virome generated in this study may be relevant to developing effective plant viral disease management and control strategies.


Assuntos
Coinfecção , Nanismo , Vírus de Plantas , Vírus de RNA , Humanos , Viroma , Ecossistema , Cnidium/genética , RNA Viral/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Vírus de Plantas/genética , DNA , Filogenia
4.
Commun Biol ; 7(1): 462, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38627534

RESUMO

Plant viruses evolves diverse strategies to overcome the limitations of their genomic capacity and express multiple proteins, despite the constraints imposed by the host translation system. Broad bean wilt virus 2 (BBWV2) is a widespread viral pathogen, causing severe damage to economically important crops. It is hypothesized that BBWV2 RNA2 possesses two alternative in-frame translation initiation codons, resulting in the production of two largely overlapping proteins, VP53 and VP37. In this study, we aim to investigate the expression and function of VP53, an N-terminally 128-amino-acid-extended form of the viral movement protein VP37, during BBWV2 infection. By engineering various recombinant and mutant constructs of BBWV2 RNA2, here we demonstrate that VP53 is indeed expressed during BBWV2 infection. We also provide evidence of the translation of the two overlapping proteins through ribosomal leaky scanning. Furthermore, our study highlights the indispensability of VP53 for successful systemic infection of BBWV2, as its removal results in the loss of virus infectivity. These insights into the translation mechanism and functional role of VP53 during BBWV2 infection significantly contribute to our understanding of the infection mechanisms employed by fabaviruses.


Assuntos
Fabavirus , Vírus de Plantas , Fabavirus/genética , Proteínas Virais/genética , Proteínas Virais/metabolismo , Vírus de Plantas/genética
5.
Viruses ; 16(3)2024 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-38543792

RESUMO

The structural study of plant viruses is of great importance to reduce the damage caused by these agricultural pathogens and to support their biotechnological applications. Nowadays, X-ray crystallography, NMR spectroscopy and cryo-electron microscopy are well accepted methods to obtain the 3D protein structure with the best resolution. However, for large and complex supramolecular structures such as plant viruses, especially flexible filamentous ones, there are a number of technical limitations to resolving their native structure in solution. In addition, they do not allow us to obtain structural information about dynamics and interactions with physiological partners. For these purposes, small-angle X-ray scattering (SAXS) and atomic force microscopy (AFM) are well established. In this review, we have outlined the main principles of these two methods and demonstrated their advantages for structural studies of plant viruses of different shapes with relatively high spatial resolution. In addition, we have demonstrated the ability of AFM to obtain information on the mechanical properties of the virus particles that are inaccessible to other experimental techniques. We believe that these under-appreciated approaches, especially when used in combination, are valuable tools for studying a wide variety of helical plant viruses, many of which cannot be resolved by classical structural methods.


Assuntos
Vírus de Plantas , Difração de Raios X , Microscopia Crioeletrônica , Espalhamento a Baixo Ângulo , Microscopia de Força Atômica/métodos , Raios X , Cristalografia por Raios X
6.
Math Biosci Eng ; 21(3): 4056-4084, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38549318

RESUMO

Roguing and elimination of vectors are the most commonly seen biological control strategies regarding the spread of plant viruses. It is practically significant to establish the mathematical models of plant virus transmission and regard the effect of removing infected plants as well as eliminating vector strategies on plant virus eradication. We proposed the mathematical models of plant virus transmission with nonlinear continuous and pulse removal of infected plants and vectors. In terms of the nonlinear continuous control strategy, the threshold values of the existence and stability of multiple equilibria have been provided. Moreover, the conditions for the occurrence of backward bifurcation were also provided. Regarding the nonlinear impulsive control strategy, the stability of the disease-free periodic solution and the threshold of the persistence of the disease were given. With the application of the fixed point theory, the conditions for the existence of forward and backward bifurcations of the model were presented. Our results demonstrated that there was a backward bifurcation phenomenon in continuous systems, and there was also a backward bifurcation phenomenon in impulsive control systems. Moreover, we found that removing healthy plants increased the threshold $ R_{1}. $ Finally, numerical simulation was employed to verify our conclusions.


Assuntos
Modelos Biológicos , Vírus de Plantas , Modelos Teóricos , Simulação por Computador , Plantas , Dinâmica não Linear
7.
J Gen Virol ; 105(3)2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38441560

RESUMO

Plant viruses are transmitted mechanically or by vegetative propagation, and by vectors such as arthropods, fungi, nematodes, or parasitic plants. Sources to access available information regarding plant virus transmissions are scattered and require extensive literature searches. Here, a recently created plant virus transmission database is described. This was developed to provide access to the modes of transmission and vectors of over 1600 plant viruses. The database was compiled using over 3500 publication records spanning the last 100 years. The information is publicly accessible via https://library.wur.nl/WebQuery/virus and fully searchable by virus name, taxonomic position, mode of transmission or vector.


Assuntos
Artrópodes , Vírus de Plantas , Animais , Vírus de Plantas/genética , Bases de Dados Factuais
8.
Int J Mol Sci ; 25(5)2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38474046

RESUMO

Post-translational modification of proteins plays a critical role in plant-pathogen interactions. Here, we demonstrate in Nicotiana benthamiana that knockout of NbHAG1 promotes Chinese wheat mosaic virus (CWMV) infection, whereas NbHAG1 overexpression inhibits infection. Transcriptome sequencing indicated that a series of disease resistance-related genes were up-regulated after overexpression of NbHAG1. In addition, cleavage under targets and tagmentation (Cut&Tag)-qPCR results demonstrated that NbHAG1 may activate the transcription of its downstream disease-resistance genes by facilitating the acetylation level of H3K36ac. Therefore, we suggest that NbHAG1 is an important positive regulator of resistance to CWMV infestation.


Assuntos
Resistência à Doença , Vírus de Plantas , Humanos , Vírus de Plantas/genética , Processamento de Proteína Pós-Traducional , Doenças das Plantas , Proteínas de Plantas/genética , Regulação da Expressão Gênica de Plantas
9.
BMC Plant Biol ; 24(1): 172, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38443837

RESUMO

BACKGROUND: Plant responses to a wide range of stresses are known to be regulated by epigenetic mechanisms. Pathogen-related investigations, particularly against RNA viruses, are however scarce. It has been demonstrated that Arabidopsis thaliana plants defective in some members of the RNA-directed DNA methylation (RdDM) or histone modification pathways presented differential susceptibility to the turnip mosaic virus. In order to identify genes directly targeted by the RdDM-related RNA Polymerase V (POLV) complex and the histone demethylase protein JUMONJI14 (JMJ14) during infection, the transcriptomes of infected mutant and control plants were obtained and integrated with available chromatin occupancy data for various epigenetic proteins and marks. RESULTS: A comprehensive list of virus-responsive gene candidates to be regulated by the two proteins was obtained. Twelve genes were selected for further characterization, confirming their dynamic regulation during the course of infection. Several epigenetic marks on their promoter sequences were found using in silico data, raising confidence that the identified genes are actually regulated by epigenetic mechanisms. The altered expression of six of these genes in mutants of the methyltransferase gene CURLY LEAF and the histone deacetylase gene HISTONE DEACETYLASE 19 suggests that some virus-responsive genes may be regulated by multiple coordinated epigenetic complexes. A temporally separated multiple plant virus infection experiment in which plants were transiently infected with one virus and then infected by a second one was designed to investigate the possible roles of the identified POLV- and JMJ14-regulated genes in wild-type (WT) plants. Plants that had previously been stimulated with viruses were found to be more resistant to subsequent virus challenge than control plants. Several POLV- and JMJ14-regulated genes were found to be regulated in virus induced resistance in WT plants, with some of them poisoned to be expressed in early infection stages. CONCLUSIONS: A set of confident candidate genes directly regulated by the POLV and JMJ14 proteins during virus infection was identified, with indications that some of them may be regulated by multiple epigenetic modules. A subset of these genes may also play a role in the tolerance of WT plants to repeated, intermittent virus infections.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Vírus de Plantas , Viroses , Metilação de DNA , Arabidopsis/genética , Histona Desacetilases , Histona Desmetilases com o Domínio Jumonji
10.
Gene ; 913: 148385, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38493973

RESUMO

Juglans sigillata Dode is one of the important tree species in southwest China, and it has significant economic and ecological value. However, there is still a lack of effective methods to identify the functional genes of J. sigillata. By verifying the model plant tobacco, the pTRV2::JsPDS vector was able to cause photobleaching. This study showed that photobleaching occurred 24 and 30 d after the silencing vector was infected with aseptic seedlings and fruits of J. sigillata, respectively. When the OD600 was 0.6, and the injection dose was 500 µL, the gene silencing efficiency of aseptic seedlings was the highest at 16.7 %, significantly better than other treatments. Moreover, when the OD600 was 0.8, and the injection dose was 500 µL, the gene silencing efficiency in the walnut fruit was the highest (20 %). In addition, the VIGS system was successfully used to silence JsFLS2 and JsFLS4 genes in J. sigillata. This study also showed that the flavonol content and gene expression in the treatment group were decreased compared to the control group. In addition, the proteins transcribed and translated from the JsFLS4 gene may have higher catalytic activity for dihydroquercetin. The above results indicate that the TRV-mediated VIGS system can be an ideal tool for studying J. sigillata gene function.


Assuntos
Juglans , Vírus de Plantas , Juglans/genética , Inativação Gênica , Fenótipo , Frutas , Tabaco , Plântula/genética , Regulação da Expressão Gênica de Plantas , Vírus de Plantas/genética
11.
Viruses ; 16(2)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38400002

RESUMO

In Chile, edible herbs are mainly grown by small farmers. This type of horticultural crop typically requires intensive management because it is highly susceptible to insects, some of which transmit viruses that severely affect crop yield and quality. In 2019, in coriander plants tested negative for all previously reported viruses, RNA-Seq analysis of one symptomatic plant revealed a plethora of viruses, including one virus known to infect coriander, five viruses never reported in coriander, and a new cytorhabdovirus with a 14,180 nucleotide RNA genome for which the species name Cytorhabdovirus coriandrum was proposed. Since all the detected viruses were aphid-borne, aphids and weeds commonly growing around the coriander field were screened for viruses. The results showed the occurrence of the same seven viruses and the alfalfa mosaic virus, another aphid-borne virus, in aphids and weeds. Together, our findings document the presence of multiple viruses in coriander and the potential role of weeds as virus reservoirs for aphid acquisition.


Assuntos
Afídeos , Coriandrum , Vírus de Plantas , Vírus , Animais , Chile/epidemiologia , Plantas , Doenças das Plantas , Vírus de Plantas/genética
12.
New Phytol ; 241(5): 2275-2286, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38327027

RESUMO

Plant-derived volatiles mediate interactions among plants, pathogenic viruses, and viral vectors. These volatile-dependent mechanisms have not been previously demonstrated belowground, despite their likely significant role in soil ecology and agricultural pest impacts. We investigated how the plant virus, tobacco rattle virus (TRV), attracts soil nematode vectors to infected plants. We infected Nicotiana benthamiana with TRV and compared root growth relative to that of uninfected plants. We tested whether TRV-infected N. benthamiana was more attractive to nematodes 7 d post infection and identified a compound critical to attraction. We also infected N. benthamiana with mutated TRV strains to identify virus genes involved in vector nematode attraction. Virus titre and associated impacts on root morphology were greatest 7 d post infection. Tobacco rattle virus infection enhanced 2-ethyl-1-hexanol production. Nematode chemotaxis and 2-ethyl-1-hexanol production correlated strongly with viral load. Uninfected plants were more attractive to nematodes after the addition of 2-ethyl-1-hexanol than were untreated plants. Mutation of TRV RNA2-encoded genes reduced the production of 2-ethyl-1-hexanol and nematode attraction. For the first time, this demonstrates that virus-driven alterations in root volatile emissions lead to increased chemotaxis of the virus's nematode vector, a finding with implications for sustainable management of both nematodes and viral pathogens in agricultural systems.


Assuntos
Hexanóis , Nematoides , Vírus de Plantas , Animais , Solo , Vírus de Plantas/genética
13.
Virology ; 593: 110011, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38367474

RESUMO

BACKGROUND: Groundnut (Arachis hypogaea L.) is the 13th most important global crop grown throughout the tropical and subtropical regions of the world. One of the major constraints to groundnut production is viruses, which are also the most economically important and most abundant pathogens among cultivated legumes. Only a few studies have reported the characterization of RNA viruses in cultivated groundnuts in western Kenya, most of which deployed classical methods of detecting known viruses. METHODS: We sampled twenty-one symptomatic and three asymptomatic groundnut leaf samples from farmers' fields in western Kenya. Total RNA was extracted from the samples followed by First-strand cDNA synthesis and sequencing on the Illumina HiSeq 2500 platform. After removing host and rRNA sequences, high-quality viral RNA sequences were de novo assembled and viral genomes annotated using the publicly available NCBI virus database. Multiple sequence alignment and phylogenetic analysis were done using MEGA X. RESULTS: Bioinformatics analyses using as low as ∼3.5 million reads yielded complete and partial genomes for Cauliflower mosaic virus (CaMV), Cowpea polerovirus 2 (CPPV2), Groundnut rosette assistor virus (GRAV), Groundnut rosette virus (GRV), Groundnut rosette virus satellite RNA (satRNA) and Peanut mottle virus (PeMoV) falling within the species demarcation criteria. This is the first report of CaMV and the second report of CPPV2 on groundnut hosts in the world. Confirmation of the detected viruses was further verified through phylogenetic analyses alongside reported publicly available highly similar viruses. PeMoV was the only seed-borne virus reported. CONCLUSION: Our findings demonstrate the power of Next Generation Sequencing in the discovery and identification of novel viruses in groundnuts. The detection of the new viruses indicates the complexity of virus diseases in groundnuts and would require more focus in future studies to establish the effect of the viruses as sole or mixed infections on the crop. The detection of PeMoV with potential origin from Malawi indicates the importance of seed certification and cross-boundary seed health testing.


Assuntos
Fabaceae , Luteoviridae , Vírus de Plantas , Vírus de RNA , Tombusviridae , Caulimovirus/genética , Quênia , Filogenia , Vírus de Plantas/genética , Vírus de RNA/genética , Fabaceae/genética , Luteoviridae/genética , Perfilação da Expressão Gênica
14.
Virology ; 592: 109998, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38301447

RESUMO

Plant viruses are responsible for nearly 47 % of all crop losses brought by plant diseases, which have a considerable negative impact on agricultural output. Nanoparticles have the potential to greatly raise agricultural output due to their wonderful applications in the fields of highly sensitive biomolecular detection, disease diagnostics, antimicrobials, and therapeutic compounds. The application of nanotechnology in plant virology is known as nanophytovirology, and it involves biostimulation, drug transport, genetic manipulation, therapeutic agents, and induction of plant defenses. The inactivation and denaturation of capsid protein, nucleic acids (RNA or DNA), and other protein constituents are involved in the underlying mechanism. To determine the precise mechanism by which nanoparticles affect viral mobility, reproduction, encapsidation, and transmission, more research is however required. Nanoparticles can be used to precisely detect plant viruses using nanobiosensors or as biostimulants. The varieties of nanoparticles employed in plant virus control and their methods of virus suppression are highlighted in this review.


Assuntos
Nanopartículas , Vírus de Plantas , Vírus de Plantas/genética , Proteínas do Capsídeo/genética , RNA Viral/genética , Doenças das Plantas/prevenção & controle
15.
J Virol Methods ; 326: 114904, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38368949

RESUMO

Fig mosaic virus (FMV) is recognized as the main viral agent associated with the mosaic disease (MD) of fig trees (Ficus carica). Due to its worldwide occurrence, FMV represents the most significant global threat to the production of fig fruit. A disease management strategy against the MD in fig orchards has never been effective; and therefore, expression of recombinant antibody in plant cells could provide an alternative approach to suppress FMV infections. In this study we focused on expressing a specific recombinant antibody, a single-chain variable fragment (scFv), targeting the nucleocapsid protein (NP) of FMV in planta. To accomplish this objective, we inserted the scFv gene into a plant expression vector and conducted transient expression in leaves of Nicotiana tabacum cv. Samson plants. The construct was transiently expressed in tobacco plants by agroinfiltration, and antibody of the anticipated size was detected by immunoblotting. The produced plantibody was then assessed for specificity using ELISA and confirmed by Western blot analysis. In this study, the plantibody developed against FMV could be considered as a potential countermeasure to the infection by conferring resistance to MD.


Assuntos
Vírus de Plantas , Anticorpos de Cadeia Única , Proteínas do Nucleocapsídeo , Anticorpos de Cadeia Única/genética , Vírus de Plantas/genética , Plantas , Tabaco/genética , Proteínas Recombinantes/genética
16.
J Virol Methods ; 326: 114905, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38387695

RESUMO

Plant virus detection and identification in crops is a pillar for disease management, import of crop material, production of clean stock plants and basic plant virology studies. In this report, we present a platform for the enrichment and isolation of known or unknown viruses. This platform is based on carbon nanotube arrays inside a microfluidic device that can be a solution for the identification of low titer viruses from plants. Using our microfluidic devices, we achieved enrichment of two economically important viruses, the orthotospovirus, tomato spotted wilt orthotospovirus (TSWV) and the potyvirus, zucchini yellow mosaic virus (ZYMV). The carbon nanotube arrays integrated in these microfluidic devices are capable of trapping viruses discriminated by their size; the virus rich arrays can be then analyzed by common downstream techniques including immunoassays, PCR, HTS and electron microscopy. This procedure offers a simple to operate and portable sample preparation device capable of trapping viruses from raw plant extracts while reducing the host contamination.


Assuntos
Nanotubos de Carbono , Vírus de Plantas , Microfluídica , Doenças das Plantas
17.
Biomolecules ; 14(1)2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38254661

RESUMO

Plant virus genomes encode proteins that are involved in replication, encapsidation, cell-to-cell, and long-distance movement, avoidance of host detection, counter-defense, and transmission from host to host, among other functions. Even though the multifunctionality of plant viral proteins is well documented, contemporary functional repertoires of individual proteins are incomplete. However, these can be enhanced by modeling tools. Here, predictive modeling of proteins encoded by the two genomic RNAs, i.e., RNA1 and RNA2, of grapevine fanleaf virus (GFLV) and their satellite RNAs by a suite of protein prediction software confirmed not only previously validated functions (suppressor of RNA silencing [VSR], viral genome-linked protein [VPg], protease [Pro], symptom determinant [Sd], homing protein [HP], movement protein [MP], coat protein [CP], and transmission determinant [Td]) and previously identified putative functions (helicase [Hel] and RNA-dependent RNA polymerase [Pol]), but also predicted novel functions with varying levels of confidence. These include a T3/T7-like RNA polymerase domain for protein 1AVSR, a short-chain reductase for protein 1BHel/VSR, a parathyroid hormone family domain for protein 1EPol/Sd, overlapping domains of unknown function and an ABC transporter domain for protein 2BMP, and DNA topoisomerase domains, transcription factor FBXO25 domain, or DNA Pol subunit cdc27 domain for the satellite RNA protein. Structural predictions for proteins 2AHP/Sd, 2BMP, and 3A? had low confidence, while predictions for proteins 1AVSR, 1BHel*/VSR, 1CVPg, 1DPro, 1EPol*/Sd, and 2CCP/Td retained higher confidence in at least one prediction. This research provided new insights into the structure and functions of GFLV proteins and their satellite protein. Future work is needed to validate these findings.


Assuntos
Vírus de Plantas , Vírus de Plantas/genética , Endopeptidases , Proteínas de Plantas/genética , DNA Topoisomerases Tipo I , Peptídeo Hidrolases , DNA Helicases
18.
Nat Commun ; 15(1): 3, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38167823

RESUMO

Salivary effectors of piercing-sucking insects can suppress plant defense to promote insect feeding, but it remains largely elusive how they facilitate plant virus transmission. Leafhopper Nephotettix cincticeps transmits important rice reovirus via virus-packaging exosomes released from salivary glands and then entering the rice phloem. Here, we report that intact salivary vitellogenin of N. cincticeps (NcVg) is associated with the GTPase Rab5 of N. cincticeps (NcRab5) for release from salivary glands. In virus-infected salivary glands, NcVg is upregulated and packaged into exosomes mediated by virus-induced NcRab5, subsequently entering the rice phloem. The released NcVg inherently suppresses H2O2 burst of rice plants by interacting with rice glutathione S-transferase F12, an enzyme catalyzing glutathione-dependent oxidation, thus facilitating leafhoppers feeding. When leafhoppers transmit virus, virus-upregulated NcVg thus promotes leafhoppers feeding and enhances viral transmission. Taken together, the findings provide evidence that viruses exploit insect exosomes to deliver virus-hijacked effectors for efficient transmission.


Assuntos
Hemípteros , Vírus de Plantas , Animais , Vitelogeninas , Floema , Peróxido de Hidrogênio
19.
Proc Natl Acad Sci U S A ; 121(3): e2315341121, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38190519

RESUMO

Wing dimorphism of insect vectors is a determining factor for viral long-distance dispersal and large-area epidemics. Although plant viruses affect the wing plasticity of insect vectors, the potential underlying molecular mechanisms have seldom been investigated. Here, we found that a planthopper-vectored rice virus, rice stripe virus (RSV), specifically induces a long-winged morph in male insects. The analysis of field populations demonstrated that the long-winged ratios of male insects are closely associated with RSV infection regardless of viral titers. A planthopper-specific and testis-highly expressed gene, Encounter, was fortuitously found to play a key role in the RSV-induced long-winged morph. Encounter resembles malate dehydrogenase in the sequence, but it does not have corresponding enzymatic activity. Encounter is upregulated to affect male wing dimorphism at early larval stages. Encounter is closely connected with the insulin/insulin-like growth factor signaling pathway as a downstream factor of Akt, of which the transcriptional level is activated in response to RSV infection, resulting in the elevated expression of Encounter. In addition, an RSV-derived small interfering RNA directly targets Encounter to enhance its expression. Our study reveals an unreported mechanism underlying the direct regulation by a plant virus of wing dimorphism in its insect vectors, providing the potential way for interrupting viral dispersal.


Assuntos
Epidemias , Vírus de Plantas , Infecções por Vírus Respiratório Sincicial , Tenuivirus , Masculino , Animais , Vírus de Plantas/genética , Tenuivirus/genética , Insetos Vetores , 60515
20.
Methods Mol Biol ; 2771: 119-126, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38285398

RESUMO

RNA silencing (also known as gene silencing) is an evolutionary conserved mechanism that is involved in regulating gene expression, suppressing mobile elements, and defensing virus infection. RNA silencing is triggered by double-stranded RNA via Dicer or Dicer-like riboendonucleases. DsRNAs are also the replication intermediates of all RNA viruses; as a result, plant RNA viruses are ideal candidates to induce RNA silencing. A large body of plant viruses have been modified into vectors for RNA silencing in varied plant species. Here, we described a simple, time-saving, and operable system for gene function and genetic breeding study of potato and Nicotiana benthamiana using a potato mop-top (MPTV)-based vector.


Assuntos
Vírus de Plantas , RNA de Cadeia Dupla , RNA de Cadeia Dupla/genética , Vírus de Plantas/genética , Doenças das Plantas/genética , Melhoramento Vegetal , Inativação Gênica
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