scholarly journals Geminiviruses encode additional small proteins with specific subcellular localizations and virulence function

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pan Gong ◽  
Huang Tan ◽  
Siwen Zhao ◽  
Hao Li ◽  
Hui Liu ◽  
...  
Keyword(s):  
Rna Silencing ◽  
Plant Viruses ◽  
Tomato Yellow Leaf ◽  
Silencing Suppressor ◽  
Comprehensive Overview ◽  
Small Proteins ◽  
Encoded Proteins ◽  
Leaf Curl Virus ◽  
Small Orfs ◽  
Coding Capacity

AbstractGeminiviruses are plant viruses with limited coding capacity. Geminivirus-encoded proteins are traditionally identified by applying a 10-kDa arbitrary threshold; however, it is increasingly clear that small proteins play relevant roles in biological systems, which calls for the reconsideration of this criterion. Here, we show that geminiviral genomes contain additional ORFs. Using tomato yellow leaf curl virus, we demonstrate that some of these small ORFs are expressed during the infection, and that the encoded proteins display specific subcellular localizations. We prove that the largest of these additional ORFs, which we name V3, is required for full viral infection, and that the V3 protein localizes in the Golgi apparatus and functions as an RNA silencing suppressor. These results imply that the repertoire of geminiviral proteins can be expanded, and that getting a comprehensive overview of the molecular plant-geminivirus interactions will require the detailed study of small ORFs so far neglected.

scholarly journals Geminiviral genomes encode additional proteins with specific subcellular localizations and virulence function

2021 ◽  
Author(s):  
Pan Gong ◽  
Huang Tan ◽  
Siwen Zhao ◽  
Hao Li ◽  
Hui Liu ◽  
...  
Keyword(s):  
Rna Silencing ◽  
Plant Viruses ◽  
Tomato Yellow Leaf ◽  
Silencing Suppressor ◽  
Comprehensive Overview ◽  
Small Proteins ◽  
Encoded Proteins ◽  
Leaf Curl Virus ◽  
Small Orfs ◽  
Coding Capacity

ABSTRACTGeminiviruses are plant viruses with limited coding capacity. Geminivirus-encoded proteins were identified applying a 10-kDa arbitrary threshold; however, it is increasingly clear that small proteins play relevant roles in biological systems, which calls for the reconsideration of this criterion. Here, we show that geminiviral genomes contain additional ORFs. Using tomato yellow leaf curl virus, we demonstrate that some of these novel ORFs are expressed during the infection, and that the encoded proteins display specific subcellular localizations. We prove that the largest of these new ORFs, which we name V3, is required for full viral infection, and that the V3 protein localizes in the Golgi apparatus and functions as an RNA silencing suppressor. These results imply that the repertoire of geminiviral proteins can be expanded, and that getting a comprehensive overview of the molecular plant-geminivirus interactions will require the detailed study of small ORFs so far neglected.

scholarly journals Factors Determining Transmission of Persistent Viruses by Bemisia tabaci and Emergence of New Virus–Vector Relationships

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1808
Author(s):  
Saptarshi Ghosh ◽  
Murad Ghanim
Keyword(s):  
Bemisia Tabaci ◽  
Plant Viruses ◽  
Tomato Yellow Leaf ◽  
Tissue Tropism ◽  
Insect Vectors ◽  
Virus Species ◽  
Yellow Leaf ◽  
Virus Diseases ◽  
Persistent Viruses ◽  
Leaf Curl Virus

Many plant viruses depend on insect vectors for their transmission and dissemination. The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is one of the most important virus vectors, transmitting more than four hundred virus species, the majority belonging to begomoviruses (Geminiviridae), with their ssDNA genomes. Begomoviruses are transmitted by B. tabaci in a persistent, circulative manner, during which the virus breaches barriers in the digestive, hemolymph, and salivary systems, and interacts with insect proteins along the transmission pathway. These interactions and the tissue tropism in the vector body determine the efficiency and specificity of the transmission. This review describes the mechanisms involved in circulative begomovirus transmission by B. tabaci, focusing on the most studied virus in this regard, namely the tomato yellow leaf curl virus (TYLCV) and its closely related isolates. Additionally, the review aims at drawing attention to the recent knowhow of unorthodox virus—B. tabaci interactions. The recent knowledge of whitefly-mediated transmission of two recombinant poleroviruses (Luteoviridae), a virus group with an ssRNA genome and known to be strictly transmitted with aphids, is discussed with its broader context in the emergence of new whitefly-driven virus diseases.

scholarly journals Rapid screening of RNA silencing suppressors by using a recombinant virus derived from beet necrotic yellow vein virus

2009 ◽  
Vol 90 (10) ◽  
pp. 2536-2541 ◽  
Author(s):  
H. Guilley ◽  
D. Bortolamiol ◽  
G. Jonard ◽  
S. Bouzoubaa ◽  
V. Ziegler-Graff
Keyword(s):  
Rna Silencing ◽  
Plant Defence ◽  
Plant Viruses ◽  
Yellow Vein ◽  
Rapid Screening ◽  
Silencing Suppressor ◽  
Defence Mechanisms ◽  
Simple Method ◽  
Yellow Dwarf Virus ◽  
Plant Defence Mechanisms

To counteract plant defence mechanisms, plant viruses have evolved to encode RNA silencing suppressor (RSS) proteins. These proteins can be identified by a range of silencing suppressor assays. Here, we describe a simple method using beet necrotic yellow vein virus (BNYVV) that allows a rapid screening of RSS activity. The viral inoculum consisted of BNYVV RNA1, which encodes proteins involved in viral replication, and two BNYVV-derived replicons: rep3–P30, which expresses the movement protein P30 of tobacco mosaic virus, and rep5–X, which allows the expression of a putative RSS (X). This approach has been validated through the use of several known RSSs. Two potential candidates have been tested and we show that, in our system, the P13 protein of burdock mottle virus displays RSS activity while the P0 protein of cereal yellow dwarf virus-RPV does not.

scholarly journals Interaction with host SGS3 is required for suppression of RNA silencing by tomato yellow leaf curl virus V2 protein

2007 ◽  
Vol 105 (1) ◽  
pp. 157-161 ◽  
Author(s):  
E. Glick ◽  
A. Zrachya ◽  
Y. Levy ◽  
A. Mett ◽  
D. Gidoni ◽  
...  
Keyword(s):  
Rna Silencing ◽  
Tomato Yellow Leaf ◽  
Yellow Leaf ◽  
Leaf Curl Virus ◽  
Leaf Curl

scholarly journals Deciphering the RNA Silencing Suppressor Function in the Potyvirus SPV2

Proceedings ◽  
2020 ◽  
Vol 50 (1) ◽  
pp. 26
Author(s):  
Ornela Chase ◽  
Giannina Bambaren ◽  
Juan José López-Moya
Keyword(s):  
Rna Silencing ◽  
Ipomoea Batatas ◽  
Control Strategies ◽  
Regulation Of Gene Expression ◽  
Plant Viruses ◽  
High Yield ◽  
Gene Products ◽  
Silencing Suppressor ◽  
Sweet Potatoes ◽  
Rna Silencing Suppressor

In most eukaryotes, RNA silencing is a key element in the regulation of gene expression and defense against pathogens. Plants have developed a defensive barrier against exogenous microorganisms, such as plant-infecting viruses, by specifically targeting and degrading the viral RNAs and thus limiting the negative effects of the diseases caused by them. On the other hand, plant viruses encode for suppressor proteins that repress the host-silencing machinery, hence allowing viral replication and infection establishment. Our current project focuses on the characterization of gene products contributing to the RNA silencing suppressor (RSS) function of Sweet potato virus 2 (SPV2), genus Potyvirus, family Potyviridae. SPV2 infects sweet potatoes (Ipomoea batatas, family Convolvulaceae), one of the most important staple food crops worldwide. Infections by potyvirids result in the high yield losses of sweet potatoes, especially from coinfection with unrelated viruses, and our final goal is to develop efficient control strategies. Our preliminary results analyzing the P1 and HCPro proteases of SPV2, transiently expressed in N. benthamiana together with a reporter GFP construct, revealed that HCPro constitutes a strong RSS. This is a novel finding, and we are currently characterizing the functions of other gene products.

scholarly journals The Cucumber vein yellowing virus Silencing Suppressor P1b Can Functionally Replace HCPro in Plum pox virus Infection in a Host-Specific Manner

2012 ◽  
Vol 25 (2) ◽  
pp. 151-164 ◽  
Author(s):  
Alberto Carbonell ◽  
Gabriela Dujovny ◽  
Juan Antonio García ◽  
Adrian Valli
Keyword(s):  
Rna Silencing ◽  
Deleterious Effect ◽  
Prunus Persica ◽  
Plant Viruses ◽  
Natural Host ◽  
Plum Pox Virus ◽  
Silencing Suppressor ◽  
Specific Manner ◽  
Silencing Suppression ◽  
Yellowing Virus

Plant viruses of the genera Potyvirus and Ipomovirus (Potyviridae family) use unrelated RNA silencing suppressors (RSS) to counteract antiviral RNA silencing responses. HCPro is the RSS of Potyvirus spp., and its activity is enhanced by the upstream P1 protein. Distinctively, the ipomovirus Cucumber vein yellowing virus (CVYV) lacks HCPro but contains two P1 copies in tandem (P1aP1b), the second of which functions as RSS. Using chimeras based on the potyvirus Plum pox virus (PPV), we found that P1b can functionally replace HCPro in potyviral infections of Nicotiana plants. Interestingly, P1a, the CVYV protein homologous to potyviral P1, disrupted the silencing suppression activity of P1b and reduced the infection efficiency of PPV in Nicotiana benthamiana. Testing the influence of RSS in host specificity, we found that a P1b-expressing chimera poorly infected PPV's natural host, Prunus persica. Conversely, P1b conferred on PPV chimeras the ability to replicate locally in cucumber, CVYV's natural host. The deleterious effect of P1a on PPV infection is host dependent, because the P1aP1b-expressing PPV chimera accumulated in cucumber to higher levels than PPV expressing P1b alone. These results demonstrate that a potyvirus can use different RSS, and that particular RSS and upstream P1-like proteins contribute to defining the virus host range.

scholarly journals Suppressor of RNA silencing encoded by Tomato yellow leaf curl virus-Israel

Virology ◽  
2007 ◽  
Vol 358 (1) ◽  
pp. 159-165 ◽  
Author(s):  
Avi Zrachya ◽  
Efrat Glick ◽  
Yael Levy ◽  
Tzahi Arazi ◽  
Vitaly Citovsky ◽  
...  
Keyword(s):  
Rna Silencing ◽  
Tomato Yellow Leaf ◽  
Yellow Leaf ◽  
Leaf Curl Virus ◽  
Suppressor Of Rna Silencing ◽  
Leaf Curl

scholarly journals The Coat Protein of Citrus Yellow Vein Clearing Virus Interacts with Viral Movement Proteins and Serves as an RNA Silencing Suppressor

Viruses ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 329 ◽  
Author(s):  
Atta Ur Rehman ◽  
Zhuoran Li ◽  
Zuokun Yang ◽  
Muhammad Waqas ◽  
Guoping Wang ◽  
...  
Keyword(s):  
Coat Protein ◽  
Rna Silencing ◽  
Triple Gene Block ◽  
Plant Viruses ◽  
Epidermal Cells ◽  
Yellow Vein ◽  
Silencing Suppressor ◽  
Vein Clearing ◽  
Rna Silencing Suppressor ◽  
Viral Movement

Citrus yellow vein clearing virus is a newly accepted member of the genus Mandarivirus in the family Alphaflexiviridae. The triple gene block proteins (TGBp1, TGBp2 and TGBp3) encoded by plant viruses in this family function on facilitating virus movement. However, the protein function of citrus yellow vein clearing virus (CYVCV) have never been explored. Here, we showed in both yeast two-hybrid (Y2H) and bimolecular fluorescence (BiFC) assays that the coat protein (CP), TGBp1 and TGBp2 of CYVCV are self-interacting. Its CP also interacts with all three TGB proteins, and TGBp1 and TGBp2 interact with each other but not with TGBp3. Furthermore, the viral CP colocalizes with TGBp1 and TGBp3 at the plasmodesmata (PD) of epidermal cells of Nicotiana benthamiana leaves, and TGBp1 can translocate TGBp2 from granular-like structures embedded within ER networks to the PD. The results suggest that these proteins could coexist at the PD of epidermal cells of N. benthamiana. Using Agrobacterium infiltration-mediated RNA silencing assays, we show that CYVCV CP is a strong RNA silencing suppressor (RSS) triggered by positive-sense green fluorescent protein (GFP) RNA. The presented results provide insights for further revealing the mechanism of the viral movement and suppression of RNA silencing.

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