1
|
Yang X, Luo X, Zhang Y, Zhang Z, OuYang X, Shi X, Lv X, Li F, Zhang S, Liu Y, Zhang D. Tomato chlorosis virus CPm protein is a pathogenicity determinant and suppresses host local RNA silencing induced by single-stranded RNA. Front Microbiol 2023; 14:1151747. [PMID: 37056753 PMCID: PMC10086252 DOI: 10.3389/fmicb.2023.1151747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 03/10/2023] [Indexed: 03/30/2023] Open
Abstract
IntroductionTomato chlorosis virus (ToCV) is a typical member of the genus Crinivirus, which severely threatens Solanaceae crops worldwide. The CPm protein encoded by ToCV has been reported to be associated with virus transmission by vectors and is involved in RNA silencing suppression, while the mechanisms remain ambiguous.MethodsHere, ToCV CPm was ectopically expressed by a Potato virus X (PVX) vector and infiltrated into Nicotiana benthamiana wild-type and GFP-transgenic16c plants.ResultsThe phylogenetic analysis showed that the CPm proteins encoded by criniviruses were distinctly divergent in amino acid sequences and predicted conserved domains, and the ToCV CPm protein possesses a conserved domain homologous to the TIGR02569 family protein, which does not occur in other criniviruses. Ectopic expression of ToCV CPm using a PVX vector resulted in severe mosaic symptoms followed by a hypersensitive-like response in N. benthamiana. Furthermore, agroinfiltration assays in N. benthamiana wilt type or GFP-transgenic 16c indicated that ToCV CPm protein effectively suppressed local RNA silencing induced by single-stranded but not double-stranded RNA, which probably resulted from the activity of binding double-stranded but not single-stranded RNA by ToCV CPm protein.ConclusionTaken together, the results of this study suggest that the ToCV CPm protein possesses the dual activities of pathogenicity and RNA silencing, which might inhibit host post-transcriptional gene silencing (PTGS)-mediated resistance and is pivotal in the primary process of ToCV infecting hosts.
Collapse
Affiliation(s)
- Xiao Yang
- Longping Branch, College of Biology, Hunan University, Changsha, Hunan, China
| | - Xiangwen Luo
- Longping Branch, College of Biology, Hunan University, Changsha, Hunan, China
- Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, Hunan, China
| | - Yu Zhang
- Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, Hunan, China
| | - Zhanhong Zhang
- Longping Branch, College of Biology, Hunan University, Changsha, Hunan, China
- Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, Hunan, China
| | - Xian OuYang
- Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, Hunan, China
| | - Xiaobin Shi
- Longping Branch, College of Biology, Hunan University, Changsha, Hunan, China
- Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, Hunan, China
| | - Xiaoyuan Lv
- Technical Center of Changsha Customs, Changsha, Hunan, China
| | - Fan Li
- College of Plant Protection, Yunnan Agricultural University, Kunming, China
| | - Songbai Zhang
- Longping Branch, College of Biology, Hunan University, Changsha, Hunan, China
- Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, Hunan, China
- *Correspondence: Songbai Zhang,
| | - Yong Liu
- Longping Branch, College of Biology, Hunan University, Changsha, Hunan, China
- Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, Hunan, China
- Yong Liu,
| | - Deyong Zhang
- Longping Branch, College of Biology, Hunan University, Changsha, Hunan, China
- Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, Hunan, China
- Deyong Zhang,
| |
Collapse
|
2
|
Discovery of novel whitefly vector proteins that interact with a virus capsid component mediating virion retention and transmission. Int J Biol Macromol 2023; 226:1154-1165. [PMID: 36427615 DOI: 10.1016/j.ijbiomac.2022.11.229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/20/2022] [Accepted: 11/21/2022] [Indexed: 11/24/2022]
Abstract
Specificity and efficiency of plant virus transmission depend largely on protein-protein interactions of vectors and viruses. Cucurbit chlorotic yellows virus (CCYV), transmitted specifically by tobacco whitefly, Bemisia tabaci, in a semi-persistent manner, has caused serious damage on cucurbit and vegetable crops around the world. However, the molecular mechanism of interaction during CCYV retention and transmission are still lacking. CCYV was proven to bind particularly to the whitefly foregut, and here, we confirmed that the minor coat protein (CPm) of CCYV is participated in the interaction with the vector. In order to identify proteins of B. tabaci that interact directly with CPm of CCYV, the immunoprecipitation (IP) assay and DUALmembrane cDNA library screening technology were applied. The cytochrome c oxidase subunit 5A (COX), tubulin beta chain (TUB) and keratin, type I cytoskeletal 9-like (KRT) of B. tabaci shown strong interactions with CPm and are closely associated with the retention within the vector and transmission of CCYV. These findings on whitefly protein-CCYV CPm interactions are crucial for a much better understanding the mechanism of semi-persistent plant virus transmission by insect vectors, as well as for implement new strategies for effective management of plant viruses and their vector insects.
Collapse
|
3
|
Mostert I, Bester R, Burger JT, Maree HJ. Identification of Interactions between Proteins Encoded by Grapevine Leafroll-Associated Virus 3. Viruses 2023; 15:208. [PMID: 36680248 PMCID: PMC9865355 DOI: 10.3390/v15010208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/06/2023] [Accepted: 01/08/2023] [Indexed: 01/13/2023] Open
Abstract
The roles of proteins encoded by members of the genus Ampelovirus, family Closteroviridae are largely inferred by sequence homology or analogy to similarly located ORFs in related viruses. This study employed yeast two-hybrid and bimolecular fluorescence complementation assays to investigate interactions between proteins of grapevine leafroll-associated virus 3 (GLRaV-3). The p5 movement protein, HSP70 homolog, coat protein, and p20B of GLRaV-3 were all found to self-interact, however, the mechanism by which p5 interacts remains unknown due to the absence of a cysteine residue crucial for the dimerisation of the closterovirus homolog of this protein. Although HSP70h forms part of the virion head of closteroviruses, in GLRaV-3, it interacts with the coat protein that makes up the body of the virion. Silencing suppressor p20B has been shown to interact with HSP70h, as well as the major coat protein and the minor coat protein. The results of this study suggest that the virion assembly of a member of the genus Ampelovirus occurs in a similar but not identical manner to those of other genera in the family Closteroviridae. Identification of interactions of p20B with virus structural proteins provides an avenue for future research to explore the mechanisms behind the suppression of host silencing and suggests possible involvement in other aspects of the viral replication cycle.
Collapse
Affiliation(s)
- Ilani Mostert
- Department of Genetics, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Rachelle Bester
- Department of Genetics, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
- Citrus Research International, P.O. Box 2201, Matieland 7602, South Africa
| | - Johan T. Burger
- Department of Genetics, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Hans J. Maree
- Department of Genetics, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
- Citrus Research International, P.O. Box 2201, Matieland 7602, South Africa
| |
Collapse
|
4
|
Wang H, Chen Q, Liu L, Zhou Y, Wang H, Li Z, Liu J. Identification of Endogenous Genes for Normalizing Titer Variation of Citrus Tristeza Virus in Aphids at Different Post-acquisition Feeding Times. THE PLANT PATHOLOGY JOURNAL 2022; 38:287-295. [PMID: 35953048 PMCID: PMC9372102 DOI: 10.5423/ppj.oa.01.2022.0011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 05/27/2022] [Accepted: 06/06/2022] [Indexed: 06/15/2023]
Abstract
Citrus tristeza virus (CTV) is efficiently transmitted in a semi-persistent manner by the brown citrus aphid (Toxoptera citricida (Kirkaldy)). Currently, the most sensitive method for detecting plant viruses in insect vectors is reverse-transcription quantitative polymerase chain reaction (RT-qPCR). In this study, the elongation factor-1 alpha (EF-1α) gene and acidic p0 ribosomal protein (RPAP0) gene were confirmed to be suitable reference genes for RT-qPCR normalization in viruliferous T. citricida aphids using the geNorm, NormFinder, and BestKeeper tools. Then the relative CTV titer in aphids (T. citricida) at different post-acquisition feeding times on healthy plants was quantified by RT-qPCR using EF-1α and RPAP0 as reference genes. The relative CTV titer retained in the aphids gradually decreased with increasing feeding time. During the first 0.5 h of feeding time on healthy plants, the remaining CTV titer in aphids showed about 80% rapid loss for the highly transmissible isolate CT11A and 40% loss for the poorly transmissible isolate CTLJ. The relative CTV titer in aphids during more than 12 h post-acquisition times for CT11A was significantly lower than at the other feeding times, which is similar to the trend found for CTLJ. To our knowledge, this is the first report about the relative titer variation of CTV remaining in T. citricida at different post-acquisition feeding times on healthy plants.
Collapse
Affiliation(s)
- Hongsu Wang
- Citrus Research Institute, Southwest University, Chongqing 400712,
China
- Sichuan Provincial Key Laboratory of Quality and Innovation Research of Chinese Materia Medica, Sichuan Academy of Chinese Medicine Sciences, Chengdu 610041,
China
| | - Qi Chen
- Citrus Research Institute, Southwest University, Chongqing 400712,
China
- National Citrus Engineering Research Center, Chongqing 400712,
China
| | - Luqin Liu
- Citrus Research Institute, Southwest University, Chongqing 400712,
China
- National Citrus Engineering Research Center, Chongqing 400712,
China
| | - Yan Zhou
- Citrus Research Institute, Southwest University, Chongqing 400712,
China
- National Citrus Engineering Research Center, Chongqing 400712,
China
| | - Huanhuan Wang
- Citrus Research Institute, Southwest University, Chongqing 400712,
China
- National Citrus Engineering Research Center, Chongqing 400712,
China
| | - Zhongan Li
- Citrus Research Institute, Southwest University, Chongqing 400712,
China
- National Citrus Engineering Research Center, Chongqing 400712,
China
| | - Jinxiang Liu
- Citrus Research Institute, Southwest University, Chongqing 400712,
China
- National Citrus Engineering Research Center, Chongqing 400712,
China
| |
Collapse
|
5
|
Lindenau S, Winter S, Margaria P. The Amino-Proximal Region of the Coat Protein of Cucumber Vein Yellowing Virus (Family Potyviridae) Affects the Infection Process and Whitefly Transmission. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10122771. [PMID: 34961241 PMCID: PMC8706179 DOI: 10.3390/plants10122771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 05/02/2023]
Abstract
Most plant viruses rely on vector transmission for their spread and specific interactions between vector and virus have evolved to regulate this relationship. The whitefly Bemisia tabaci- transmitted cucumber vein yellowing virus (CVYV; genus Ipomovirus, family Potyviridae) is endemic in the Mediterranean Basin, where it causes significant losses in cucurbit crops. In this study, the role of the coat protein (CP) of CVYV for B. tabaci transmission and plant infection was investigated using a cloned and infectious CVYV cDNA and a collection of point and deletion mutants derived from this clone. Whitefly transmission of CVYV was abolished in a deletion mutant lacking amino acids in position 93-105 of the CP. This deletion mutant caused more severe disease symptoms compared to the cDNA clone representing the wild-type (wt) virus and movement efficiency was likewise affected. Two virus mutants carrying a partially restored CP were transmissible and showed symptoms comparable to the wt virus. Collectively, our data demonstrate that the N-terminus of the CVYV CP is a determinant for transmission by the whitefly vector and is involved in plant infection and symptom expression.
Collapse
|
6
|
Ng JCK, Peng JHC, Chen AYS, Tian T, Zhou JS, Smith TJ. Plasticity of the lettuce infectious yellows virus minor coat protein (CPm) in mediating the foregut retention and transmission of a chimeric CPm mutant by whitefly vectors. J Gen Virol 2021; 102:001652. [PMID: 34494949 PMCID: PMC8567426 DOI: 10.1099/jgv.0.001652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 07/16/2021] [Indexed: 01/04/2023] Open
Abstract
Transmission of the crinivirus, lettuce infectious yellows virus (LIYV), is determined by a minor coat protein (CPm)-mediated virion retention mechanism located in the foregut of its whitefly vector. To better understand the functions of LIYV CPm, chimeric CPm mutants engineered with different lengths of the LIYV CPm amino acid sequence and that of the crinivirus, lettuce chlorosis virus (LCV), were constructed based on bioinformatics and sequence alignment data. The 485 amino acid-long chimeric CPm of LIYV mutant, CPmP-1, contains 60 % (from position 3 to 294) of LCV CPm amino acids. The chimeric CPm of mutants CPmP-2, CPmP-3 and CPmP-4 contains 46 (position 3 to 208), 51 (position 3 to 238) and 41 % (position 261 to 442) of LCV CPm amino acids, respectively. All four mutants moved systemically, expressed the chimeric CPm and formed virus particles. However, following acquisition feeding of the virus preparations, only CPmP-1 was retained in the foreguts of a significant number of vectors and transmitted. In immuno-gold labelling transmission electron microscopy (IGL-TEM) analysis, CPmP-1 particles were distinctly labelled by antibodies directed against the LCV but not LIYV CPm. In contrast, CPmP-4 particles were not labelled by antibodies directed against the LCV or LIYV CPm, while CPmP-2 and -3 particles were weakly labelled by anti-LIYV CPm but not anti-LCV CPm antibodies. The unique antibody recognition and binding pattern of CPmP-1 was also displayed in the foreguts of whitefly vectors that fed on CPmP-1 virions. These results are consistent with the hypothesis that the chimeric CPm of CPmP-1 is incorporated into functional virions, with the LCV CPm region being potentially exposed on the surface and accessible to anti-LCV CPm antibodies.
Collapse
Affiliation(s)
- James C. K. Ng
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, USA
- Center for Infectious Disease and Vector Research, University of California, Riverside, CA 92521, USA
| | - James H. C. Peng
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, USA
| | - Angel Y. S. Chen
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, USA
| | - Tongyan Tian
- California Department of Food and Agriculture, Sacramento, CA 95832, USA
| | - Jaclyn S. Zhou
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, USA
| | - Thomas J. Smith
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, TX, 77555, USA
| |
Collapse
|
7
|
Chen AYS, Zhou JS, Liu JX, Ng JCK. Nuances of Whitefly Vector-Crinivirus Interactions Revealed in the Foregut Retention and Transmission of Lettuce Chlorosis Virus by Two Bemisia tabaci Cryptic Species. Viruses 2021; 13:v13081578. [PMID: 34452445 PMCID: PMC8402701 DOI: 10.3390/v13081578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 07/28/2021] [Accepted: 08/03/2021] [Indexed: 11/16/2022] Open
Abstract
Lettuce infectious yellows virus is the first crinivirus for which the retention of purified virions ingested into the whitefly (Bemisia tabaci New World (NW)) vector's foregut, has been demonstrated to be a requisite for successful virus transmission. This key finding supports the hypothesis that the determinant of foregut retention and transmission is present on the virion itself. However, whether this is also true for other criniviruses has not been established. Here, we provide evidence that lettuce chlorosis virus (LCV) acquired from plants is retained in the foreguts of both the B. tabaci NW and Middle East-Asia Minor 1 (MEAM1) vector species and transmitted upon inoculation feeding. An association between foregut retention and transmission by NW vectors is also observed following the acquisition and inoculation feeding of LCV virions purified using a standard procedure involving 2% or 4% (v/v) Triton™ X-100 (TX-100). However, while virions purified with 2% or 4% TX-100 are also retained in the foreguts of MEAM1 vectors, transmission is observed with the 4% TX-100-purified virions or when more vectors are used for acquisition and inoculation feeding. These results suggest that an intrinsic difference exists between NW and MEAM1 vectors in their interactions with, and transmission of, LCV virions.
Collapse
Affiliation(s)
- Angel Y. S. Chen
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, USA; (A.Y.S.C.); (J.S.Z.)
| | - Jaclyn S. Zhou
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, USA; (A.Y.S.C.); (J.S.Z.)
| | - Jin-Xiang Liu
- Citrus Research Institute, Southwest University, Beibei, Chongqing 400712, China;
- Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South St., Beijing 100080, China
| | - James C. K. Ng
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, USA; (A.Y.S.C.); (J.S.Z.)
- Center for Infectious Diseases and Vector Research, University of California, Riverside, CA 92521, USA
- Correspondence: ; Tel.: +1-(951)-827-4239
| |
Collapse
|
8
|
Rajarapu SP, Ullman DE, Uzest M, Rotenberg D, Ordaz NA, Whitfield AE. Plant–Virus–Vector Interactions. Virology 2021. [DOI: 10.1002/9781119818526.ch7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
9
|
Agranovsky A. Enhancing Capsid Proteins Capacity in Plant Virus-Vector Interactions and Virus Transmission. Cells 2021; 10:cells10010090. [PMID: 33430410 PMCID: PMC7827187 DOI: 10.3390/cells10010090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/02/2021] [Accepted: 01/04/2021] [Indexed: 12/02/2022] Open
Abstract
Vector transmission of plant viruses is basically of two types that depend on the virus helper component proteins or the capsid proteins. A number of plant viruses belonging to disparate groups have developed unusual capsid proteins providing for interactions with the vector. Thus, cauliflower mosaic virus, a plant pararetrovirus, employs a virion associated p3 protein, the major capsid protein, and a helper component for the semi-persistent transmission by aphids. Benyviruses encode a capsid protein readthrough domain (CP-RTD) located at one end of the rod-like helical particle, which serves for the virus transmission by soil fungal zoospores. Likewise, the CP-RTD, being a minor component of the luteovirus icosahedral virions, provides for persistent, circulative aphid transmission. Closteroviruses encode several CPs and virion-associated proteins that form the filamentous helical particles and mediate transmission by aphid, whitefly, or mealybug vectors. The variable strategies of transmission and evolutionary ‘inventions’ of the unusual capsid proteins of plant RNA viruses are discussed.
Collapse
|
10
|
Mittapelly P, Rajarapu SP. Applications of Proteomic Tools to Study Insect Vector-Plant Virus Interactions. Life (Basel) 2020; 10:E143. [PMID: 32784674 PMCID: PMC7459587 DOI: 10.3390/life10080143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/24/2020] [Accepted: 08/05/2020] [Indexed: 11/20/2022] Open
Abstract
Proteins are crucial players of biological interactions within and between the organisms and thus it is important to understand the role of proteins in successful partnerships, such as insect vectors and their plant viruses. Proteomic approaches have identified several proteins at the interface of virus acquisition and transmission by their insect vectors which could be potential molecular targets for sustainable pest and viral disease management strategies. Here we review the proteomic techniques used to study the interactions of insect vector and plant virus. Our review will focus on the techniques available to identify the infection, global changes at the proteome level in insect vectors, and protein-protein interactions of insect vectors and plant viruses. Furthermore, we also review the integration of other techniques with proteomics and the available bioinformatic tools to analyze the proteomic data.
Collapse
Affiliation(s)
- Priyanka Mittapelly
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA;
- USDA APHIS PPQ, 5936 Ford Ct, Ste. 200, Brighton, MI 48116, USA
| | - Swapna Priya Rajarapu
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA;
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
| |
Collapse
|
11
|
Gautam S, Gadhave KR, Buck JW, Dutta B, Coolong T, Adkins S, Srinivasan R. Virus-virus interactions in a plant host and in a hemipteran vector: Implications for vector fitness and virus epidemics. Virus Res 2020; 286:198069. [PMID: 32574679 DOI: 10.1016/j.virusres.2020.198069] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 06/14/2020] [Accepted: 06/16/2020] [Indexed: 10/24/2022]
Abstract
Mixed virus infection in host plants can differentially alter the plant phenotype, influence vector fitness, and affect virus acquisition and inoculation by vectors than single-virus infection. Vector acquisition of multiple viruses from multiple host plants could also differentially affect vector fitness and virus inoculation than acquisition of one virus. Whitefly-virus pathosystems in the southern United States include both the above-stated facets. For the first facet, this study examined the effects of single and mixed infection of cucurbit leaf crumple virus (CuLCrV, a begomovirus) and cucurbit yellow stunting disorder virus (CYSDV, a crinivirus) infecting squash on whitefly (Bemisia tabaci Gennadius MEAM1) host preference and fitness. Mixed infection of CuLCrV and CYSDV in squash plants severely altered their phenotype than single infection. The CYSDV load was reduced in mixed-infected squash plants than in singly-infected plants. Consequently, whiteflies acquired reduced amounts of CYSDV from mixed-infected plants than singly-infected plants. No differences in CuLCrV load were found between singly- and mixed-infected squash plants, and acquisition of CuLCrV by whiteflies did not vary between singly- and mixed-infected squash plants. Both singly- and mixed-infected plants similarly affected whitefly preference, wherein non-viruliferous and viruliferous (CuLCrV and/or CYSDV) whiteflies preferred non-infected plants over infected plants. The fitness study involving viruliferous and non-viruliferous whiteflies revealed no differences in developmental time and fecundity. For the second facet, this study evaluated the effects of individual or combined acquisition of tomato-infecting tomato yellow leaf curl virus (TYLCV, a begomovirus) and squash-infecting CuLCrV on whitefly host preference and fitness. Whiteflies that acquired both CuLCrV and TYLCV had significantly lower CuLCrV load than whiteflies that acquired CuLCrV alone, whereas TYLCV load remained unaltered when acquired individually or in conjunction with CuLCrV. Whitefly preference was not affected following individual or combined virus acquisition. Viruliferous (CuLCrV and/or TYLCV) whiteflies preferred to settle on non-infected tomato and squash plants. The mere presence of CuLCrV and/or TYLCV in whiteflies did not affect their fitness. Taken together, these results indicate that mixed infection of viruses in host plants and acquisition of multiple viruses by the vector could have implications for virus accumulation, virus acquisition, vector preference, and epidemics that sometimes are different from single-virus infection or acquisition.
Collapse
Affiliation(s)
- Saurabh Gautam
- Department of Entomology, University of Georgia, 1109 Experiment Street, Griffin, GA, 30223, USA
| | - Kiran R Gadhave
- Department of Entomology, University of Georgia, 1109 Experiment Street, Griffin, GA, 30223, USA
| | - James W Buck
- Department of Plant Pathology, University of Georgia, 1109 Experiment St., Griffin, GA, 30223, USA
| | - Bhabesh Dutta
- Department of Plant Pathology, University of Georgia, 3250 Rainwater Road, Tifton, GA, 31793, USA
| | - Tim Coolong
- Department of Horticulture, University of Georgia, 3250 Rainwater Road, Tifton, GA, 31793, USA
| | - Scott Adkins
- USDA-ARS, U.S. Horticultural Research Laboratory, Fort Pierce, FL, 34945, USA
| | - Rajagopalbabu Srinivasan
- Department of Entomology, University of Georgia, 1109 Experiment Street, Griffin, GA, 30223, USA.
| |
Collapse
|
12
|
Yang H, Zu G, Liu Y, Xie D, Gan X, Song B. Tomato Chlorosis Virus Minor Coat Protein as a Novel Target To Screen Antiviral Drugs. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:3425-3433. [PMID: 32091891 DOI: 10.1021/acs.jafc.9b08215] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Minor coat protein (mCP), an important component of tomato chlorosis virus (ToCV), plays a significant role in the process of virus assembly and movement and is directly related to the virus-insect transmission. Therefore, ToCV mCP could be considered as a potent target for anti-ToCV drugs. In this study, ToCV mCP was first cloned, expressed, purified, and a novel target to screen the antiviral agents. The results showed that some antiviral compounds bound to ToCV mCP with strongly affinities in vitro, including quinazoline derivatives 4a and 4b, Ningnanmycin, and Ribavirin. Subsequently, three-dimensional-quantitative structure-activity relationship (3D-QSAR) analysis was performed based on the binding affinities, and the model indicated that 4a and 4b had indeed stronger binding effects on ToCV mCP than other quinazoline derivatives. Finally, the anti-ToCV activities of compounds 4a and 4b were evaluated by quantitative real-time polymerase chain reaction in vivo. Compounds 4a and 4b inhibited infection of ToCV in the host and as well as reduced the level of ToCV mCP gene expression. Thus, ToCV mCP can be used as a novel drug target for screening anti-ToCV agents, and the ligand-based 3D-QSAR analysis of quinazoline derivatives provided new insights into the design and optimization of novel anti-ToCV drug molecules based on ToCV mCP.
Collapse
Affiliation(s)
- Huanyu Yang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Guangcheng Zu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Yuewen Liu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Dandan Xie
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Xiuhai Gan
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Baoan Song
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| |
Collapse
|
13
|
Kolliopoulou A, Kontogiannatos D, Swevers L. The Use of Engineered Plant Viruses in a Trans-Kingdom Silencing Strategy Against Their Insect Vectors. FRONTIERS IN PLANT SCIENCE 2020; 11:917. [PMID: 32733507 PMCID: PMC7360853 DOI: 10.3389/fpls.2020.00917] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 06/04/2020] [Indexed: 05/04/2023]
Abstract
Plants, plant viruses, and their vectors are co-evolving actors that co-exist and interact in nature. Insects are the most important vectors of plant viruses, serving as both carriers and hosts for the virus. This trans-kingdom interaction can be harnessed for the production of recombinant plant viruses designed to target insect genes via the RNAi machinery. The selection of the adequate viruses is important since they must infect and preferentially replicate in both the host plant and the insect vector. The routes of transmission that determine the extent of the infection inside the insect vary among different plant viruses. In the context of the proposed strategy, plant viruses that are capable of transversing the insect gut-hemocoel barrier and replicating in insect tissues are attractive candidates. Thus, the transmission of such viruses in a persistent and propagative manner is considered as a prerequisite for this strategy to be feasible, a characteristic that is found in viruses from the families Bunyaviridae, Reoviridae, and Rhabdoviridae. In addition, several RNA viruses are known that replicate in both plant and insect tissues via a yet unclarified transmission route. In this review, advances in knowledge of trans-kingdom transmission of plant viruses and future perspectives for their engineering as silencing vectors are thoroughly discussed.
Collapse
Affiliation(s)
- Anna Kolliopoulou
- Institute of Biosciences & Applications, National Centre for Scientific Research “Demokritos”, Agia Paraskevi, Greece
- Department of Biomedical Sciences, University of West Attica, Egaleo, Greece
- *Correspondence: Anna Kolliopoulou,
| | - Dimitrios Kontogiannatos
- Institute of Biosciences & Applications, National Centre for Scientific Research “Demokritos”, Agia Paraskevi, Greece
| | - Luc Swevers
- Institute of Biosciences & Applications, National Centre for Scientific Research “Demokritos”, Agia Paraskevi, Greece
| |
Collapse
|
14
|
Fiallo‐Olivé E, Navas‐Castillo J. Tomato chlorosis virus, an emergent plant virus still expanding its geographical and host ranges. MOLECULAR PLANT PATHOLOGY 2019; 20:1307-1320. [PMID: 31267719 PMCID: PMC6715620 DOI: 10.1111/mpp.12847] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
UNLABELLED Tomato chlorosis virus (ToCV) causes an important disease that primarily affects tomato, although it has been found infecting other economically important vegetable crops and a wide range of wild plants. First described in Florida (USA) and associated with a 'yellow leaf disorder' in the mid-1990s, ToCV has been found in 35 countries and territories to date, constituting a paradigmatic example of an emergent plant pathogen. ToCV is transmitted semipersistently by whiteflies (Hemiptera: Aleyrodidae) belonging to the genera Bemisia and Trialeurodes. Whitefly transmission is highly efficient and cases of 100% infection are frequently observed in the field. To date, no resistant or tolerant tomato plants are commercially available and the control of the disease relies primarily on the control of the insect vector. TAXONOMY Tomato chlorosis virus is one of the 14 accepted species in the genus Crinivirus, one of the four genera in the family Closteroviridae of plant viruses. VIRION AND GENOME PROPERTIES The genome of ToCV is composed of two molecules of single-stranded positive-sense RNA, named RNA1 and RNA2, separately encapsidated in long, flexuous, rod-like virions. As has been shown for other closterovirids, ToCV virions are believed to have a bipolar structure. RNA1 contains four open reading frames (ORFs) encoding proteins associated with virus replication and suppression of gene silencing, whereas RNA2 contains nine ORFs encoding proteins putatively involved in encapsidation, cell-to-cell movement, gene silencing suppression and whitefly transmission. HOST RANGE In addition to tomato, ToCV has been found to infect 84 dicot plant species belonging to 25 botanical families, including economically important crops. TRANSMISSION Like all species within the genus Crinivirus, ToCV is semipersistently transmitted by whiteflies, being one of only two criniviruses transmitted by members of the genera Bemisia and Trialeurodes. DISEASE SYMPTOMS Tomato 'yellow leaf disorder' syndrome includes interveinal yellowing and thickening of leaves. Symptoms first develop on lower leaves and then advance towards the upper part of the plant. Bronzing and necrosis of the older leaves are accompanied by a decline in vigour and reduction in fruit yield. In other hosts the most common symptoms include interveinal chlorosis and mild yellowing on older leaves. CONTROL Control of the disease caused by ToCV is based on the use of healthy seedlings for transplanting, limiting accessibility of alternate host plants that can serve as virus reservoirs and the spraying of insecticides for vector control. Although several wild tomato species have been shown to contain genotypes resistant to ToCV, there are no commercially available resistant or tolerant tomato varieties to date.
Collapse
Affiliation(s)
- Elvira Fiallo‐Olivé
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas – Universidad de Málaga (IHSM‐CSIC‐UMA)Avenida Dr. Wienberg s/n29750Algarrobo‐Costa, MálagaSpain
| | - Jesús Navas‐Castillo
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas – Universidad de Málaga (IHSM‐CSIC‐UMA)Avenida Dr. Wienberg s/n29750Algarrobo‐Costa, MálagaSpain
| |
Collapse
|
15
|
Kaur N, Chen W, Fei Z, Wintermantel WM. Differences in gene expression in whitefly associated with CYSDV-infected and virus-free melon, and comparison with expression in whiteflies fed on ToCV- and TYLCV-infected tomato. BMC Genomics 2019; 20:654. [PMID: 31416422 PMCID: PMC6694564 DOI: 10.1186/s12864-019-5999-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 07/26/2019] [Indexed: 01/31/2023] Open
Abstract
Background Cucurbit yellow stunting disorder virus (CYSDV; genus Crinivirus, Closteroviridae) is transmitted in a semipersistent manner by the whitefly, Bemisia tabaci, and is efficiently transmitted by the widely prevalent B. tabaci cryptic species, MEAM1. In this study, we compared transcriptome profiles of B. tabaci MEAM1, after 24 h, 72 h and 7 days of acquisition feeding on melon plants infected with CYSDV (CYSDV-whiteflies) with those fed on virus-free melon, using RNA-Seq technology. We also compared transcriptome profiles with whiteflies fed on tomato plants separately infected with Tomato chlorosis virus (ToCV), a crinivirus closely related to CYSDV, and Tomato yellow leaf curl virus (TYLCV), a member of the genus Begomovirus, which has a distinctly different mode of transmission and their respective virus-free controls, to find common gene expression changes among viruliferous whiteflies feeding on different host plants infected with distinct (TYLCV) and related (CYSDV and ToCV) viruses. Results A total of 275 differentially expressed genes (DEGs) were identified in CYSDV-whiteflies, with 3 DEGs at 24 h, 221 DEGs at 72 h, and 51 DEGs at 7 days of virus acquisition. Changes in genes encoding orphan genes (54 genes), phosphatidylethanolamine-binding proteins (PEBP) (20 genes), and AAA-ATPase domain containing proteins (10 genes) were associated with the 72 h time point. Several more orphan genes (20 genes) were differentially expressed at 7 days. A total of 59 common DEGs were found between CYSDV-whiteflies and ToCV-whiteflies, which included 20 orphan genes and 6 lysosomal genes. A comparison of DEGs across the three different virus-host systems revealed 14 common DEGs, among which, eight showed similar and significant up-regulation in CYSDV-whiteflies at 72 h and TYLCV-whiteflies at 24 h, while down-regulation of the same genes was observed in ToCV-whiteflies at 72 h. Conclusions Dynamic gene expression changes occurred in CYSDV-whiteflies after 72 h feeding, with decreased gene expression changes associated with 7 days of CYSDV acquisition. Similarities in gene expression changes among CYSDV-whiteflies, ToCV-whiteflies and TYLCV-whiteflies suggest the possible involvement of common genes or pathways for virus acquisition and transmission by whiteflies, even for viruses with distinctly different modes of transmission. Electronic supplementary material The online version of this article (10.1186/s12864-019-5999-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Navneet Kaur
- USDA-ARS, Crop Improvement and Protection Research, 1636 East Alisal Street, Salinas, CA, 93905, USA.,Present Address: Driscoll's Inc., 151 Silliman Rd., Watsonville, CA, 95076, USA
| | - Wenbo Chen
- Boyce Thompson Institute, 533 Tower Road, Ithaca, New York, 14853-1801, USA
| | - Zhangjun Fei
- Boyce Thompson Institute, 533 Tower Road, Ithaca, New York, 14853-1801, USA.,USDA-ARS, Robert W. Holley Center for Agriculture and Health, 538 Tower Road, Ithaca, New York, 14853-2901, USA
| | - William M Wintermantel
- USDA-ARS, Crop Improvement and Protection Research, 1636 East Alisal Street, Salinas, CA, 93905, USA.
| |
Collapse
|
16
|
Mann KS, Sanfaçon H. Expanding Repertoire of Plant Positive-Strand RNA Virus Proteases. Viruses 2019; 11:v11010066. [PMID: 30650571 PMCID: PMC6357015 DOI: 10.3390/v11010066] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 01/11/2019] [Accepted: 01/12/2019] [Indexed: 12/13/2022] Open
Abstract
Many plant viruses express their proteins through a polyprotein strategy, requiring the acquisition of protease domains to regulate the release of functional mature proteins and/or intermediate polyproteins. Positive-strand RNA viruses constitute the vast majority of plant viruses and they are diverse in their genomic organization and protein expression strategies. Until recently, proteases encoded by positive-strand RNA viruses were described as belonging to two categories: (1) chymotrypsin-like cysteine and serine proteases and (2) papain-like cysteine protease. However, the functional characterization of plant virus cysteine and serine proteases has highlighted their diversity in terms of biological activities, cleavage site specificities, regulatory mechanisms, and three-dimensional structures. The recent discovery of a plant picorna-like virus glutamic protease with possible structural similarities with fungal and bacterial glutamic proteases also revealed new unexpected sources of protease domains. We discuss the variety of plant positive-strand RNA virus protease domains. We also highlight possible evolution scenarios of these viral proteases, including evidence for the exchange of protease domains amongst unrelated viruses.
Collapse
Affiliation(s)
- Krin S Mann
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, BC V0H 1Z0, Canada.
| | - Hélène Sanfaçon
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, BC V0H 1Z0, Canada.
| |
Collapse
|
17
|
Qiao W, Medina V, Kuo YW, Falk BW. A Distinct, Non-Virion Plant Virus Movement Protein Encoded by a Crinivirus Essential for Systemic Infection. mBio 2018; 9:e02230-18. [PMID: 30459200 PMCID: PMC6247084 DOI: 10.1128/mbio.02230-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 10/17/2018] [Indexed: 12/21/2022] Open
Abstract
Plant-infecting viruses utilize various strategies involving multiple viral and host factors to achieve successful systemic infections of their compatible hosts. Lettuce infectious yellows virus (LIYV), genus Crinivirus, family Closteroviridae, has long, filamentous flexuous virions and causes phloem-limited infections in its plant hosts. The LIYV-encoded P26 is a distinct non-virion protein that shows no similarities to proteins in current databases: it induces plasmalemma deposits over plasmadesmata (PD) pit fields and is speculated to have roles in LIYV virion transport within infected plants. In this study, P26 was demonstrated to be a PD-localized protein, and its biological significance was tested in planta by mutagenesis analysis. An LIYV P26 knockout mutant (P26X) showed viral RNA replication and virion formation in inoculated leaves of Nicotiana benthamiana plants, but failed to give systemic infection. Confirmation by using a modified green fluorescent protein (GFP)-tagged LIYV P26X showed GFP accumulation only in infiltrated leaf tissues, while wild-type LIYV GFP readily spread systemically in the phloem. Attempts to rescue P26X by complementation in trans were negative. However a translocated LIYV P26 gene in the LIYV genome rescued systemic infection, but P26 orthologs from other criniviruses did not. Mutagenesis in planta assays showed that deletions in P26, as well as 2 of 11 specific alanine-scanning mutants, abolished the ability to systemically infect N. benthamianaIMPORTANCE Plant viruses encode specific proteins that facilitate their ability to establish multicellular/systemic infections in their host plants. Relatively little is known of the transport mechanisms for plant viruses whose infections are phloem limited, including those of the family Closteroviridae. These viruses have complex, long filamentous virions that spread through the phloem. Lettuce infectious yellows virus (LIYV) encodes a non-virion protein, P26, which forms plasmalemma deposits over plasmodesmata pit fields, and LIYV virions are consistently found attached to those deposits. Here we demonstrate that P26 is a unique movement protein required for LIYV systemic infection in plants. LIYV P26 shows no sequence similarities to other proteins, but other criniviruses encode P26 orthologs. However, these failed to complement movement of LIYV P26 mutants.
Collapse
Affiliation(s)
- Wenjie Qiao
- Department of Plant Pathology, University of California, Davis, California, USA
| | - Vicente Medina
- Department of Crop and Forest Sciences, University of Lleida, Lleida, Spain
| | - Yen-Wen Kuo
- Department of Plant Pathology, University of California, Davis, California, USA
| | - Bryce W Falk
- Department of Plant Pathology, University of California, Davis, California, USA
| |
Collapse
|
18
|
Qiao W, Zarzyńska‐Nowak A, Nerva L, Kuo Y, Falk BW. Accumulation of 24 nucleotide transgene-derived siRNAs is associated with crinivirus immunity in transgenic plants. MOLECULAR PLANT PATHOLOGY 2018; 19:2236-2247. [PMID: 29704454 PMCID: PMC6638120 DOI: 10.1111/mpp.12695] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
RNA silencing is a conserved antiviral defence mechanism that has been used to develop robust resistance against plant virus infections. Previous efforts have been made to develop RNA silencing-mediated resistance to criniviruses, yet none have given immunity. In this study, transgenic Nicotiana benthamiana plants harbouring a hairpin construct of the Lettuce infectious yellows virus (LIYV) RNA-dependent RNA polymerase (RdRp) sequence exhibited immunity to systemic LIYV infection. Deep sequencing analysis was performed to characterize virus-derived small interfering RNAs (vsiRNAs) generated on systemic LIYV infection in non-transgenic N. benthamiana plants as well as transgene-derived siRNAs (t-siRNAs) derived from the immune-transgenic plants before and after LIYV inoculation. Interestingly, a similar sequence distribution pattern was obtained with t-siRNAs and vsiRNAs mapped to the transgene region in both immune and susceptible plants, except for a significant increase in t-siRNAs of 24 nucleotides in length, which was consistent with small RNA northern blot results that showed the abundance of t-siRNAs of 21, 22 and 24 nucleotides in length. The accumulated 24-nucleotide sequences have not yet been reported in transgenic plants partially resistant to criniviruses, and thus may indicate their correlation with crinivirus immunity. To further test this hypothesis, we developed transgenic melon (Cucumis melo) plants immune to systemic infection of another crinivirus, Cucurbit yellow stunting disorder virus (CYSDV). As predicted, the accumulation of 24-nucleotide t-siRNAs was detected in transgenic melon plants by northern blot. Together with our findings and previous studies on crinivirus resistance, we propose that the accumulation of 24-nucleotide t-siRNAs is associated with crinivirus immunity in transgenic plants.
Collapse
Affiliation(s)
- Wenjie Qiao
- Department of Plant PathologyUniversity of CaliforniaDavisCAUSA, 95616
| | - Aleksandra Zarzyńska‐Nowak
- Department of Virology and BacteriologyInstitute of Plant Protection‐National Research InstitutePoznańPoland, 60‐318
| | - Luca Nerva
- Council for Agricultural Research and Economics – Research Centre for Viticulture and EnologyConegliano (TV)Italy, 00198
- Institute for Sustainable Plant ProtectionTorinoItaly, 10135
| | - Yen‐Wen Kuo
- Department of Plant PathologyUniversity of CaliforniaDavisCAUSA, 95616
| | - Bryce W. Falk
- Department of Plant PathologyUniversity of CaliforniaDavisCAUSA, 95616
| |
Collapse
|
19
|
Qiao W, Helpio EL, Falk BW. Two Crinivirus-Conserved Small Proteins, P5 and P9, Are Indispensable for Efficient Lettuce infectious yellows virus Infectivity in Plants. Viruses 2018; 10:E459. [PMID: 30154314 PMCID: PMC6163742 DOI: 10.3390/v10090459] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 08/24/2018] [Accepted: 08/27/2018] [Indexed: 01/06/2023] Open
Abstract
Genomic analysis of Lettuce infectious yellows virus (LIYV) has revealed two short open reading frames (ORFs) on LIYV RNA2, that are predicted to encode a 5-kDa (P5) and a 9-kDa (P9) protein. The P5 ORF is part of the conserved quintuple gene block in the family Closteroviridae, while P9 orthologs are found in all Criniviruses. In this study, the expression of LIYV P5 and P9 proteins was confirmed; P5 is further characterized as an endoplasmic reticulum (ER)-localized integral transmembrane protein and P9 is a soluble protein. The knockout LIYV mutants presented reduced symptom severity and virus accumulation in Nicotiana benthamiana or lettuce plants, indicating their importance in efficient virus infection. The P5 mutant was successfully complemented by a dislocated P5 in the LIYV genome. The structural regions of P5 were tested and all were found to be required for the appropriate functions of P5. In addition, P5, as well as its ortholog P6, encoded by Citrus tristeza virus (CTV) and another ER-localized protein encoded by LIYV RNA1, were found to cause cell death when expressed in N. benthamiana plants from a TMV vector, and induce ER stress and the unfolded protein response (UPR).
Collapse
Affiliation(s)
- Wenjie Qiao
- Department of Plant Pathology, University of California, Davis, CA 95616, USA.
| | - Erin L Helpio
- Department of Plant Pathology, University of California, Davis, CA 95616, USA.
| | - Bryce W Falk
- Department of Plant Pathology, University of California, Davis, CA 95616, USA.
| |
Collapse
|
20
|
Qiao W, Falk BW. Efficient Protein Expression and Virus-Induced Gene Silencing in Plants Using a Crinivirus-Derived Vector. Viruses 2018; 10:E216. [PMID: 29695039 PMCID: PMC5977209 DOI: 10.3390/v10050216] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 04/19/2018] [Accepted: 04/21/2018] [Indexed: 01/12/2023] Open
Abstract
Plant virus-based vectors are valuable tools for recombinant gene expression and functional genomics for both basic and applied research. In this study, Lettuce infectious yellows virus (LIYV) of the genus Crinivirus was engineered into a virus vector that is applicable for efficient protein expression and virus-induced gene silencing (VIGS) in plants. We examined gene replacement and “add a gene” strategies to develop LIYV-derived vectors for transient expression of the green fluorescent protein (GFP) reporter in Nicotiana benthamiana plants. The latter yielded higher GFP expression and was further examined by testing the effects of heterologous controller elements (CEs). A series of five vector constructs with progressively extended LIYV CP sgRNA CEs were tested, the longest CE gave the highest GFP expression but lower virus accumulation. The whitefly transmissibility of the optimized vector construct to other host plants, and the capability to accommodate and express a larger gene, a 1.8 kb β-glucuronidase (GUS) gene, were confirmed. Furthermore, the LIYV vector was also validated VIGS by silencing the endogenous gene, phytoene desaturase (PDS) in N. benthamiana plants, and the transgene GFP in N. benthamiana line 16c plants. Therefore, LIYV-derived vectors could provide a technical reference for developing vectors of other economically important criniviruses.
Collapse
Affiliation(s)
- Wenjie Qiao
- Department of Plant Pathology, University of California, Davis, 95616 CA, USA.
| | - Bryce W Falk
- Department of Plant Pathology, University of California, Davis, 95616 CA, USA.
| |
Collapse
|
21
|
Abstract
Viruses transmitted by whiteflies are predominantly classified as having either persistent circulative or semipersistent transmission, and the majority of studies have addressed transmission of viruses in the genera Begomovirus (family Geminiviridae) and Crinivirus (family Closteroviridae), respectively. Early studies on vector transmission primarily addressed individual aspects of transmission; however, with the breadth of new technology now available, an increasingly greater number of studies involve coordinated research that is beginning to assemble a more complete picture of how whiteflies and viruses have coevolved to facilitate transmission. In particular the integration of gene expression and metabolomic studies into broader research topics is providing knowledge of changes within the whitefly vector in response to the presence of viruses that would have been impossible to identify previously. Examples include comparative studies on the response of Bemisia tabaci to begomovirus and crinivirus infection of common host plants, evolution of whitefly endosymbiont relationships, and opportunities to evaluate responses to specific transmission-related events. Integration of metabolomics, as well as the application of electrical penetration graphing, can lead to an ability to monitor the changes that occur in vector insects associated with specific aspects of virus transmission. Through gaining more complete knowledge of the mechanisms behind whitefly transmission of viruses new control strategies will undoubtedly emerge for control of whiteflies and the viruses they transmit.
Collapse
|
22
|
Zhou JS, Chen AYS, Drucker M, Lopez NH, Carpenter A, Ng JCK. Whitefly feeding behavior and retention of a foregut-borne crinivirus exposed to artificial diets with different pH values. INSECT SCIENCE 2017; 24:1079-1092. [PMID: 28677320 DOI: 10.1111/1744-7917.12503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 06/08/2017] [Accepted: 06/21/2017] [Indexed: 06/07/2023]
Abstract
Transmission of plant viruses by phytophagous hemipteran insects encompasses complex interactions underlying a continuum of processes involved in virus acquisition, retention and inoculation combined with vector feeding behavior. Here, we investigated the effects of dietary pH on whitefly (Bemisia tabaci) feeding behavior and release of Lettuce infectious yellows virus (LIYV) virions retained in the vector's foregut. Electrical penetration graph analysis revealed that variables associated with whitefly probing and ingestion did not differ significantly in pH (4, 7.4, and 9) adjusted artificial diets. To investigate virus retention and release, whiteflies allowed to acquire LIYV virions in a pH 7.4 artificial diet were fed pH 4, 7.4, or 9 virion-free artificial (clearing) diets. Immunofluorescent localization analyses indicated that virions remained bound to the foreguts of approximately 20%-24% of vectors after they fed on each of the 3 pH-adjusted clearing diets. When RNA preparations from the clearing diets were analyzed by reverse transcription (RT) nested-PCR and, in some cases, real-time qPCR, successful amplification of LIYV-specific sequence was infrequent but consistently repeatable for the pH 7.4 diet but never observed for the pH 4 and 9 diets, suggesting a weak pH-dependent effect for virion release. Viruliferous vectors that fed on each of the 3 pH-adjusted clearing diets transmitted LIYV to virus-free plants. These results suggest that changes in pH values alone in artificial diet do not result in observable changes in whitefly feeding behaviors, an observation that marks a first in the feeding of artificial diet by whitefly vectors; and that there is a potential causal and contingent relationship between the pH in artificial diet and the release/inoculation of foregut bound virions.
Collapse
Affiliation(s)
- Jaclyn S Zhou
- Department of Plant Pathology and Microbiology, and Center for Disease Vector Research, University of California, Riverside, California, USA
| | - Angel Y S Chen
- Department of Plant Pathology and Microbiology, and Center for Disease Vector Research, University of California, Riverside, California, USA
| | - Martin Drucker
- INRA, UMR BGPI Plant Pathogen Interactions, Montpellier Cedex 5, France
| | | | | | - James C K Ng
- Department of Plant Pathology and Microbiology, and Center for Disease Vector Research, University of California, Riverside, California, USA
| |
Collapse
|
23
|
Qiao W, Medina V, Falk BW. Inspirations on Virus Replication and Cell-to-Cell Movement from Studies Examining the Cytopathology Induced by Lettuce infectious yellows virus in Plant Cells. FRONTIERS IN PLANT SCIENCE 2017; 8:1672. [PMID: 29021801 PMCID: PMC5623981 DOI: 10.3389/fpls.2017.01672] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 09/12/2017] [Indexed: 05/06/2023]
Abstract
Lettuce infectious yellows virus (LIYV) is the type member of the genus Crinivirus in the family Closteroviridae. Like many other positive-strand RNA viruses, LIYV infections induce a number of cytopathic changes in plant cells, of which the two most characteristic are: Beet yellows virus-type inclusion bodies composed of vesicles derived from cytoplasmic membranes; and conical plasmalemma deposits (PLDs) located at the plasmalemma over plasmodesmata pit fields. The former are not only found in various closterovirus infections, but similar structures are known as 'viral factories' or viroplasms in cells infected with diverse types of animal and plant viruses. These are generally sites of virus replication, virion assembly and in some cases are involved in cell-to-cell transport. By contrast, PLDs induced by the LIYV-encoded P26 non-virion protein are not involved in replication but are speculated to have roles in virus intercellular movement. These deposits often harbor LIYV virions arranged to be perpendicular to the plasma membrane over plasmodesmata, and our recent studies show that P26 is required for LIYV systemic plant infection. The functional mechanism of how LIYV P26 facilitates intercellular movement remains unclear, however, research on other plant viruses provides some insights on the possible ways of viral intercellular movement through targeting and modifying plasmodesmata via interactions between plant cellular components and viral-encoded factors. In summary, beginning with LIYV, we review the studies that have uncovered the biological determinants giving rise to these cytopathological effects and their importance in viral replication, virion assembly and intercellular movement during the plant infection by closteroviruses, and compare these findings with those for other positive-strand RNA viruses.
Collapse
Affiliation(s)
- Wenjie Qiao
- Department of Plant Pathology, University of California, Davis, Davis, CA, United States
| | - Vicente Medina
- Department of Crop and Forest Sciences, University of Lleida, Lleida, Spain
| | - Bryce W. Falk
- Department of Plant Pathology, University of California, Davis, Davis, CA, United States
| |
Collapse
|
24
|
Czosnek H, Hariton-Shalev A, Sobol I, Gorovits R, Ghanim M. The Incredible Journey of Begomoviruses in Their Whitefly Vector. Viruses 2017; 9:E273. [PMID: 28946649 PMCID: PMC5691625 DOI: 10.3390/v9100273] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 09/13/2017] [Accepted: 09/18/2017] [Indexed: 12/21/2022] Open
Abstract
Begomoviruses are vectored in a circulative persistent manner by the whitefly Bemisia tabaci. The insect ingests viral particles with its stylets. Virions pass along the food canal and reach the esophagus and the midgut. They cross the filter chamber and the midgut into the haemolymph, translocate into the primary salivary glands and are egested with the saliva into the plant phloem. Begomoviruses have to cross several barriers and checkpoints successfully, while interacting with would-be receptors and other whitefly proteins. The bulk of the virus remains associated with the midgut and the filter chamber. In these tissues, viral genomes, mainly from the tomato yellow leaf curl virus (TYLCV) family, may be transcribed and may replicate. However, at the same time, virus amounts peak, and the insect autophagic response is activated, which in turn inhibits replication and induces the destruction of the virus. Some begomoviruses invade tissues outside the circulative pathway, such as ovaries and fat cells. Autophagy limits the amounts of virus associated with these organs. In this review, we discuss the different sites begomoviruses need to cross to complete a successful circular infection, the role of the coat protein in this process and the sites that balance between virus accumulation and virus destruction.
Collapse
Affiliation(s)
- Henryk Czosnek
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel.
| | - Aliza Hariton-Shalev
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel.
| | - Iris Sobol
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel.
| | - Rena Gorovits
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel.
| | - Murad Ghanim
- Department of Entomology, Agricultural Research Organization, Volcani Center, HaMaccabim Road 68, Rishon LeZion, 7505101, Israel.
| |
Collapse
|
25
|
Kaur N, Chen W, Zheng Y, Hasegawa DK, Ling KS, Fei Z, Wintermantel WM. Transcriptome analysis of the whitefly, Bemisia tabaci MEAM1 during feeding on tomato infected with the crinivirus, Tomato chlorosis virus, identifies a temporal shift in gene expression and differential regulation of novel orphan genes. BMC Genomics 2017; 18:370. [PMID: 28494755 PMCID: PMC5426028 DOI: 10.1186/s12864-017-3751-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 05/02/2017] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Whiteflies threaten agricultural crop production worldwide, are polyphagous in nature, and transmit hundreds of plant viruses. Little is known how whitefly gene expression is altered due to feeding on plants infected with a semipersistently transmitted virus. Tomato chlorosis virus (ToCV; genus Crinivirus, family Closteroviridae) is transmitted by the whitefly (Bemisia tabaci) in a semipersistent manner and infects several globally important agricultural and ornamental crops, including tomato. RESULTS To determine changes in global gene regulation in whiteflies after feeding on tomato plants infected with a crinivirus (ToCV), comparative transcriptomic analysis was performed using RNA-Seq on whitefly (Bemisia tabaci MEAM1) populations after 24, 48, and 72 h acquisition access periods on either ToCV-infected or uninfected tomatoes. Significant differences in gene expression were detected between whiteflies fed on ToCV-infected tomato and those fed on uninfected tomato among the three feeding time periods: 447 up-regulated and 542 down-regulated at 24 h, 4 up-regulated and 7 down-regulated at 48 h, and 50 up-regulated and 160 down-regulated at 72 h. Analysis revealed differential regulation of genes associated with metabolic pathways, signal transduction, transport and catabolism, receptors, glucose transporters, α-glucosidases, and the uric acid pathway in whiteflies fed on ToCV-infected tomatoes, as well as an abundance of differentially regulated novel orphan genes. Results demonstrate for the first time, a specific and temporally regulated response by the whitefly to feeding on a host plant infected with a semipersistently transmitted virus, and advance the understanding of the whitefly vector-virus interactions that facilitate virus transmission. CONCLUSION Whitefly transmission of semipersistent viruses is believed to require specific interactions between the virus and its vector that allow binding of virus particles to factors within whitefly mouthparts. Results provide a broader understanding of the potential mechanism of crinivirus transmission by whitefly, aid in discerning genes or loci in whitefly that influence virus interactions or transmission, and subsequently facilitate development of novel, genetics-based control methods against whitefly and whitefly-transmitted viruses.
Collapse
Affiliation(s)
- Navneet Kaur
- USDA-ARS, Crop Improvement and Protection Research, 1636 East Alisal Street, Salinas, CA 93905 USA
| | - Wenbo Chen
- Boyce Thompson Institute, 533 Tower Road, Ithaca, NY 14853-1801 USA
| | - Yi Zheng
- Boyce Thompson Institute, 533 Tower Road, Ithaca, NY 14853-1801 USA
| | - Daniel K. Hasegawa
- USDA-ARS, U.S. Vegetable Laboratory, Charleston, 2700 Savannah Highway, Charleston, SC 29414 USA
| | - Kai-Shu Ling
- USDA-ARS, U.S. Vegetable Laboratory, Charleston, 2700 Savannah Highway, Charleston, SC 29414 USA
| | - Zhangjun Fei
- Boyce Thompson Institute, 533 Tower Road, Ithaca, NY 14853-1801 USA
| | - William M. Wintermantel
- USDA-ARS, Crop Improvement and Protection Research, 1636 East Alisal Street, Salinas, CA 93905 USA
| |
Collapse
|
26
|
Dietzgen RG, Mann KS, Johnson KN. Plant Virus-Insect Vector Interactions: Current and Potential Future Research Directions. Viruses 2016; 8:E303. [PMID: 27834855 PMCID: PMC5127017 DOI: 10.3390/v8110303] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/31/2016] [Accepted: 10/31/2016] [Indexed: 12/13/2022] Open
Abstract
Acquisition and transmission by an insect vector is central to the infection cycle of the majority of plant pathogenic viruses. Plant viruses can interact with their insect host in a variety of ways including both non-persistent and circulative transmission; in some cases, the latter involves virus replication in cells of the insect host. Replicating viruses can also elicit both innate and specific defense responses in the insect host. A consistent feature is that the interaction of the virus with its insect host/vector requires specific molecular interactions between virus and host, commonly via proteins. Understanding the interactions between plant viruses and their insect host can underpin approaches to protect plants from infection by interfering with virus uptake and transmission. Here, we provide a perspective focused on identifying novel approaches and research directions to facilitate control of plant viruses by better understanding and targeting virus-insect molecular interactions. We also draw parallels with molecular interactions in insect vectors of animal viruses, and consider technical advances for their control that may be more broadly applicable to plant virus vectors.
Collapse
Affiliation(s)
- Ralf G Dietzgen
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia QLD 4072, Australia.
| | - Krin S Mann
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, BC V0H 1Z0, Canada.
| | - Karyn N Johnson
- School of Biological Sciences, The University of Queensland, St. Lucia QLD 4072, Australia.
| |
Collapse
|
27
|
Minor Coat and Heat Shock Proteins Are Involved in the Binding of Citrus Tristeza Virus to the Foregut of Its Aphid Vector, Toxoptera citricida. Appl Environ Microbiol 2016; 82:6294-6302. [PMID: 27520823 DOI: 10.1128/aem.01914-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 08/10/2016] [Indexed: 02/06/2023] Open
Abstract
Vector transmission is a critical stage in the viral life cycle, yet for most plant viruses how they interact with their vector is unknown or is explained by analogy with previously described relatives. Here we examined the mechanism underlying the transmission of citrus tristeza virus (CTV) by its aphid vector, Toxoptera citricida, with the objective of identifying what virus-encoded proteins it uses to interact with the vector. Using fluorescently labeled virions, we demonstrated that CTV binds specifically to the lining of the cibarium of the aphid. Through in vitro competitive binding assays between fluorescent virions and free viral proteins, we determined that the minor coat protein is involved in vector interaction. We also found that the presence of two heat shock-like proteins, p61 and p65, reduces virion binding in vitro Additionally, treating the dissected mouthparts with proteases did not affect the binding of CTV virions. In contrast, chitinase treatment reduced CTV binding to the foregut. Finally, competition with glucose, N-acetyl-β-d-glucosamine, chitobiose, and chitotriose reduced the binding. These findings together suggest that CTV binds to the sugar moieties of the cuticular surface of the aphid cibarium, and the binding involves the concerted activity of three virus-encoded proteins. IMPORTANCE Limited information is known about the specific interactions between citrus tristeza virus and its aphid vectors. These interactions are important for the process of successful transmission. In this study, we localized the CTV retention site as the cibarium of the aphid foregut. Moreover, we demonstrated that the nature of these interactions is protein-carbohydrate binding. The viral proteins, including the minor coat protein and two heat shock proteins, bind to sugar moieties on the surface of the foregut. These findings will help in understanding the transmission mechanism of CTV by the aphid vector and may help in developing control strategies which interfere with the CTV binding to its insect vector to block the transmission.
Collapse
|
28
|
Mongkolsiriwattana C, Zhou JS, Ng JCK. A 3'-end structure in RNA2 of a crinivirus is essential for viral RNA synthesis and contributes to replication-associated translation activity. Sci Rep 2016; 6:34482. [PMID: 27694962 PMCID: PMC5046102 DOI: 10.1038/srep34482] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 09/12/2016] [Indexed: 01/31/2023] Open
Abstract
The terminal ends in the genome of RNA viruses contain features that regulate viral replication and/or translation. We have identified a Y-shaped structure (YSS) in the 3' terminal regions of the bipartite genome of Lettuce chlorosis virus (LCV), a member in the genus Crinivirus (family Closteroviridae). The YSS is the first in this family of viruses to be determined using Selective 2'-Hydroxyl Acylation Analyzed by Primer Extension (SHAPE). Using luciferase constructs/replicons, in vivo and in vitro assays showed that the 5' and YSS-containing 3' terminal regions of LCV RNA1 supported translation activity. In contrast, similar regions from LCV RNA2, including those upstream of the YSS, did not. LCV RNA2 mutants with nucleotide deletions or replacements that affected the YSS were replication deficient. In addition, the YSS of LCV RNA1 and RNA2 were interchangeable without affecting viral RNA synthesis. Translation and significant replication were observed for specific LCV RNA2 replicons only in the presence of LCV RNA1, but both processes were impaired when the YSS and/or its upstream region were incomplete or altered. These results are evidence that the YSS is essential to the viral replication machinery, and contributes to replication enhancement and replication-associated translation activity in the RNA2 replicons.
Collapse
Affiliation(s)
- Chawin Mongkolsiriwattana
- Department of Plant Pathology and Microbiology, University of California, Riverside, Riverside, California, USA
| | - Jaclyn S. Zhou
- Department of Plant Pathology and Microbiology, University of California, Riverside, Riverside, California, USA
| | - James C. K. Ng
- Department of Plant Pathology and Microbiology, University of California, Riverside, Riverside, California, USA
| |
Collapse
|
29
|
Kaur N, Hasegawa DK, Ling KS, Wintermantel WM. Application of Genomics for Understanding Plant Virus-Insect Vector Interactions and Insect Vector Control. PHYTOPATHOLOGY 2016; 106:1213-1222. [PMID: 27442532 DOI: 10.1094/phyto-02-16-0111-fi] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The relationships between plant viruses and their vectors have evolved over the millennia, and yet, studies on viruses began <150 years ago and investigations into the virus and vector interactions even more recently. The advent of next generation sequencing, including rapid genome and transcriptome analysis, methods for evaluation of small RNAs, and the related disciplines of proteomics and metabolomics offer a significant shift in the ability to elucidate molecular mechanisms involved in virus infection and transmission by insect vectors. Genomic technologies offer an unprecedented opportunity to examine the response of insect vectors to the presence of ingested viruses through gene expression changes and altered biochemical pathways. This review focuses on the interactions between viruses and their whitefly or thrips vectors and on potential applications of genomics-driven control of the insect vectors. Recent studies have evaluated gene expression in vectors during feeding on plants infected with begomoviruses, criniviruses, and tospoviruses, which exhibit very different types of virus-vector interactions. These studies demonstrate the advantages of genomics and the potential complementary studies that rapidly advance our understanding of the biology of virus transmission by insect vectors and offer additional opportunities to design novel genetic strategies to manage insect vectors and the viruses they transmit.
Collapse
Affiliation(s)
- Navneet Kaur
- First and fourth authors: USDA-ARS, Crop Improvement and Protection Research, Salinas, CA 93905; second author: USDA-ARS, U.S. Vegetable Laboratory, Charleston, SC 29414; Boyce Thompson Institute, Cornell University, Ithaca, NY 14853; and third author: USDA-ARS, U.S. Vegetable Laboratory, Charleston, SC 29414
| | - Daniel K Hasegawa
- First and fourth authors: USDA-ARS, Crop Improvement and Protection Research, Salinas, CA 93905; second author: USDA-ARS, U.S. Vegetable Laboratory, Charleston, SC 29414; Boyce Thompson Institute, Cornell University, Ithaca, NY 14853; and third author: USDA-ARS, U.S. Vegetable Laboratory, Charleston, SC 29414
| | - Kai-Shu Ling
- First and fourth authors: USDA-ARS, Crop Improvement and Protection Research, Salinas, CA 93905; second author: USDA-ARS, U.S. Vegetable Laboratory, Charleston, SC 29414; Boyce Thompson Institute, Cornell University, Ithaca, NY 14853; and third author: USDA-ARS, U.S. Vegetable Laboratory, Charleston, SC 29414
| | - William M Wintermantel
- First and fourth authors: USDA-ARS, Crop Improvement and Protection Research, Salinas, CA 93905; second author: USDA-ARS, U.S. Vegetable Laboratory, Charleston, SC 29414; Boyce Thompson Institute, Cornell University, Ithaca, NY 14853; and third author: USDA-ARS, U.S. Vegetable Laboratory, Charleston, SC 29414
| |
Collapse
|
30
|
Harper SJ, Killiny N, Tatineni S, Gowda S, Cowell SJ, Shilts T, Dawson WO. Sequence variation in two genes determines the efficacy of transmission of citrus tristeza virus by the brown citrus aphid. Arch Virol 2016; 161:3555-3559. [PMID: 27644950 DOI: 10.1007/s00705-016-3070-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 09/15/2016] [Indexed: 10/21/2022]
Abstract
Vector transmission is an important part of the viral infection cycle, yet for many viruses little is known about this process, or how viral sequence variation affects transmission efficacy. Here we examined the effect of substituting genes from the highly transmissible FS577 isolate of citrus tristeza virus (CTV) in to the poorly transmissible T36-based infectious clone. We found that introducing p65 or p61 sequences from FS577 significantly increased transmission efficacy. Interestingly, replacement of both genes produced a greater increase than either gene alone, suggesting that CTV transmission requires the concerted action of co-evolved p65 and p61 proteins.
Collapse
Affiliation(s)
- S J Harper
- Department of Plant Pathology, University of Florida, 700 Experiment Station Road, Lake Alfred, Florida, 33850, USA.
| | - N Killiny
- Department of Plant Pathology, University of Florida, 700 Experiment Station Road, Lake Alfred, Florida, 33850, USA
| | - S Tatineni
- U.S. Department of Agriculture, Agricultural Research Service, and Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - S Gowda
- Department of Plant Pathology, University of Florida, 700 Experiment Station Road, Lake Alfred, Florida, 33850, USA
| | - S J Cowell
- Department of Plant Pathology, University of Florida, 700 Experiment Station Road, Lake Alfred, Florida, 33850, USA
| | - T Shilts
- Department of Plant Pathology, University of Florida, 700 Experiment Station Road, Lake Alfred, Florida, 33850, USA
| | - W O Dawson
- Department of Plant Pathology, University of Florida, 700 Experiment Station Road, Lake Alfred, Florida, 33850, USA
| |
Collapse
|
31
|
Owen CA, Moukarzel R, Huang X, Kassem MA, Eliasco E, Aranda MA, Coutts RHA, Livieratos IC. In Vitro Synthesized RNA Generated from cDNA Clones of Both Genomic Components of Cucurbit yellow stunting disorder virus Replicates in Cucumber Protoplasts. Viruses 2016; 8:v8060170. [PMID: 27314380 PMCID: PMC4926190 DOI: 10.3390/v8060170] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 05/24/2016] [Accepted: 06/06/2016] [Indexed: 11/16/2022] Open
Abstract
Cucurbit yellow stunting disorder virus (CYSDV), a bipartite whitefly-transmitted virus, constitutes a major threat to commercial cucurbit production worldwide. Here, construction of full-length CYSDV RNA1 and RNA2 cDNA clones allowed the in vitro synthesis of RNA transcripts able to replicate in cucumber protoplasts. CYSDV RNA1 proved competent for replication; transcription of both polarities of the genomic RNA was detectable 24 h post inoculation. Hybridization of total RNA extracted from transfected protoplasts or from naturally CYSDV-infected cucurbits revealed high-level transcription of the p22 subgenomic RNA species. Replication of CYSDV RNA2 following co-transfection with RNA1 was also observed, with similar transcription kinetics. A CYSDV RNA2 cDNA clone (T3CM8Δ) comprising the 5′- and 3′-UTRs plus the 3′-terminal gene, generated a 2.8 kb RNA able to replicate to high levels in protoplasts in the presence of CYSDV RNA1. The clone T3CM8Δ will facilitate reverse genetics studies of CYSDV gene function and RNA replication determinants.
Collapse
Affiliation(s)
- Carolyn A Owen
- Department of Sustainable Agriculture, Mediterranean Agronomic Institute of Chania, Alsylio Agrokepio, Chania GR-73100, Greece.
| | - Romy Moukarzel
- Department of Sustainable Agriculture, Mediterranean Agronomic Institute of Chania, Alsylio Agrokepio, Chania GR-73100, Greece.
| | - Xiao Huang
- Sir Alexander Fleming Building, Department of Biological Sciences, Imperial College, London SW7 2AZ, UK.
| | - Mona A Kassem
- Departamento de Biología del Estrés y Patología Vegetal, Centro de Edafología y Biología Aplicada del Segura (CEBAS)-CSIC, P.O. Box 164, 30100 Espinardo, Murcia, Spain.
| | - Eleonora Eliasco
- Sir Alexander Fleming Building, Department of Biological Sciences, Imperial College, London SW7 2AZ, UK.
| | - Miguel A Aranda
- Departamento de Biología del Estrés y Patología Vegetal, Centro de Edafología y Biología Aplicada del Segura (CEBAS)-CSIC, P.O. Box 164, 30100 Espinardo, Murcia, Spain.
| | - Robert H A Coutts
- Department of Biological and Environmental Sciences, School of Life and Medical Sciences, University of Hertfordshire, College Lane, Hatfield, Hertfordshire AL10 9AB, UK.
| | - Ioannis C Livieratos
- Department of Sustainable Agriculture, Mediterranean Agronomic Institute of Chania, Alsylio Agrokepio, Chania GR-73100, Greece.
| |
Collapse
|
32
|
Ng JCK, Zhou JS. Insect vector-plant virus interactions associated with non-circulative, semi-persistent transmission: current perspectives and future challenges. Curr Opin Virol 2015; 15:48-55. [PMID: 26318639 DOI: 10.1016/j.coviro.2015.07.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 07/10/2015] [Accepted: 07/13/2015] [Indexed: 12/30/2022]
Abstract
The non-circulative, semi-persistent (NCSP) mode of insect vector-mediated plant virus transmission is shaped by biological, molecular and mechanical interactions that take place across a continuum of processes involved in virion acquisition, retention and inoculation. Our understanding of the interactive roles of virus, insect vector, and plant associated with NCSP transmission is still evolving. Mechanisms exist that determine where and how virion acquisition (from the plant) and retention (in the insect vector) are achieved, with both processes being mediated by strategies involving viral capsid proteins, in some cases aided by non-capsid proteins. By contrast, mechanisms underlying virion inoculation (to the plant) remain poorly understood. Here, we review the established paradigms as well as fresh perspectives on the mechanisms of NCSP transmission.
Collapse
Affiliation(s)
- James C K Ng
- Department of Plant Pathology and Microbiology and Center for Disease Vector Research, University of California, Riverside, CA 92521, USA.
| | - Jaclyn S Zhou
- Department of Plant Pathology and Microbiology and Center for Disease Vector Research, University of California, Riverside, CA 92521, USA
| |
Collapse
|
33
|
Insect vector-mediated transmission of plant viruses. Virology 2015; 479-480:278-89. [DOI: 10.1016/j.virol.2015.03.026] [Citation(s) in RCA: 307] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 02/17/2015] [Accepted: 03/06/2015] [Indexed: 12/24/2022]
|
34
|
Multiple functions of capsid proteins in (+) stranded RNA viruses during plant–virus interactions. Virus Res 2015; 196:140-9. [DOI: 10.1016/j.virusres.2014.11.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 11/10/2014] [Accepted: 11/12/2014] [Indexed: 11/18/2022]
|
35
|
Abrahamian PE, Abou-Jawdah Y. Whitefly-transmitted criniviruses of cucurbits: current status and future prospects. Virusdisease 2014; 25:26-38. [PMID: 24426308 PMCID: PMC3889241 DOI: 10.1007/s13337-013-0173-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 10/10/2013] [Indexed: 10/26/2022] Open
Abstract
In the past decade, crinviruses have gained interest due to their rapid widespread and destructive nature for cucurbit cultivation. Several members of the genus Crinivirus are considered emerging viruses. Currently, four criniviruses: Beet pseudo-yellows virus, Cucurbit chlorotic yellows virus, Cucurbit yellow stunting disorder virus and Lettuce infectious yellows virus have been reported to infect field- or greenhouse- grown cucurbits. Apart from their cucurbit hosts, criniviruses infect other cash crops and weeds. Criniviruses are exclusively transmitted by whiteflies. The virion titer and the vector genus or species complex are predominant factors affecting virus transmission. These criniviruses maintain genetic stability with limited intra-species variability. They share similar core genome structure and replication strategies with some variations in the non-core proteins and downstream replication processes. Management of the diseases induced by criniviruses relies on integrated disease management strategies and on resistant varieties, when available. This review will cover their epidemiology, molecular biology, detection and management.
Collapse
Affiliation(s)
- Peter E. Abrahamian
- Department of Agricultural Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, 1107 2020 Lebanon
| | - Yusuf Abou-Jawdah
- Department of Agricultural Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, 1107 2020 Lebanon
| |
Collapse
|
36
|
Kiss ZA, Medina V, Falk BW. Crinivirus replication and host interactions. Front Microbiol 2013; 4:99. [PMID: 23730299 PMCID: PMC3657685 DOI: 10.3389/fmicb.2013.00099] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Accepted: 04/06/2013] [Indexed: 01/01/2023] Open
Abstract
Criniviruses comprise one of the genera within the family Closteroviridae. Members in this family are restricted to the phloem and rely on whitefly vectors of the genera Bemisia and/or Trialeurodes for plant-to-plant transmission. All criniviruses have bipartite, positive-sense single-stranded RNA genomes, although there is an unconfirmed report of one having a tripartite genome. Lettuce infectious yellows virus (LIYV) is the type species of the genus, the best studied so far of the criniviruses and the first for which a reverse genetics system was developed. LIYV RNA 1 encodes for proteins predicted to be involved in replication, and alone is competent for replication in protoplasts. Replication results in accumulation of cytoplasmic vesiculated membranous structures which are characteristic of most studied members of the Closteroviridae. These membranous structures, often referred to as Beet yellows virus (BYV)-type vesicles, are likely sites of RNA replication. LIYV RNA 2 is replicated in trans when co-infecting cells with RNA 1, but is temporally delayed relative to RNA 1. Efficient RNA 2 replication also is dependent on the RNA 1-encoded RNA-binding protein, P34. No LIYV RNA 2-encoded proteins have been shown to affect RNA replication, but at least four, CP (major coat protein), CPm (minor coat protein), Hsp70h, and P59 are virion structural components and CPm is a determinant of whitefly transmissibility. Roles of other LIYV RNA 2-encoded proteins are largely as yet unknown, but P26 is a non-virion protein that accumulates in cells as characteristic plasmalemma deposits which in plants are localized within phloem parenchyma and companion cells over plasmodesmata connections to sieve elements. The two remaining crinivirus-conserved RNA 2-encoded proteins are P5 and P9. P5 is 39 amino acid protein and is encoded at the 5' end of RNA 2 as ORF 1 and is part of the hallmark closterovirus gene array. The orthologous gene in BYV has been shown to play a role in cell-to-cell movement and indicated to be localized to the endoplasmic reticulum as a Type III integral membrane protein. The other small protein, P9, is encoded by ORF 4 overlaps with ORF 3 that encodes the structural protein, P59. P9 seems to be unique to viruses in the genus Crinivirus, as no similar protein has been detected in viruses of the other two genera of the Closteroviridae.
Collapse
Affiliation(s)
- Zsofia A. Kiss
- Department of Plant Pathology, University of CaliforniaDavis, CA, USA
| | - Vicente Medina
- Department of Crop and Forest Sciences, University of LleidaLleida, Spain
| | - Bryce W. Falk
- Department of Plant Pathology, University of CaliforniaDavis, CA, USA
| |
Collapse
|
37
|
Tzanetakis IE, Martin RR, Wintermantel WM. Epidemiology of criniviruses: an emerging problem in world agriculture. Front Microbiol 2013; 4:119. [PMID: 23730300 PMCID: PMC3656352 DOI: 10.3389/fmicb.2013.00119] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Accepted: 04/26/2013] [Indexed: 11/13/2022] Open
Abstract
The genus Crinivirus includes the whitefly-transmitted members of the family Closteroviridae. Whitefly-transmitted viruses have emerged as a major problem for world agriculture and are responsible for diseases that lead to losses measured in the billions of dollars annually. Criniviruses emerged as a major agricultural threat at the end of the twentieth century with the establishment and naturalization of their whitefly vectors, members of the genera Trialeurodes and Bemisia, in temperate climates around the globe. Several criniviruses cause significant diseases in single infections whereas others remain asymptomatic and only cause disease when found in mixed infections with other viruses. Characterization of the majority of criniviruses has been done in the last 20 years and this article provides a detailed review on the epidemiology of this important group of viruses.
Collapse
Affiliation(s)
- Ioannis E. Tzanetakis
- Department of Plant Pathology, Division of Agriculture, University of ArkansasFayetteville, AR, USA
| | - Robert R. Martin
- Horticultural Crops Research Laboratory, United States Department of Agriculture-Agricultural Research ServiceCorvallis, OR, USA
| | - William M. Wintermantel
- Crop Improvement and Protection Research Unit, United States Department of Agriculture-Agricultural Research ServiceSalinas, CA, USA
| |
Collapse
|
38
|
Dolja VV, Koonin EV. The closterovirus-derived gene expression and RNA interference vectors as tools for research and plant biotechnology. Front Microbiol 2013; 4:83. [PMID: 23596441 PMCID: PMC3622897 DOI: 10.3389/fmicb.2013.00083] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Accepted: 03/22/2013] [Indexed: 12/24/2022] Open
Abstract
Important progress in understanding replication, interactions with host plants, and evolution of closteroviruses enabled engineering of several vectors for gene expression and virus-induced gene silencing. Due to the broad host range of closteroviruses, these vectors expanded vector applicability to include important woody plants such as citrus and grapevine. Furthermore, large closterovirus genomes offer genetic capacity and stability unrivaled by other plant viral vectors. These features provided immense opportunities for using closterovirus vectors for the functional genomics studies and pathogen control in economically valuable crops. This review briefly summarizes advances in closterovirus research during the last decade, explores the relationships between virus biology and vector design, and outlines the most promising directions for future application of closterovirus vectors.
Collapse
Affiliation(s)
- Valerian V Dolja
- Department of Botany and Plant Pathology, Oregon State University Corvallis, OR, USA ; Center for Genome Research and Biocomputing, Oregon State University Corvallis, OR, USA
| | | |
Collapse
|
39
|
Chen AYS, Pavitrin A, Ng JCK. Agroinoculation of the cloned infectious cDNAs of Lettuce chlorosis virus results in systemic plant infection and production of whitefly transmissible virions. Virus Res 2012; 169:310-5. [PMID: 22926259 DOI: 10.1016/j.virusres.2012.08.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 08/04/2012] [Accepted: 08/09/2012] [Indexed: 11/26/2022]
Abstract
Lettuce chlorosis virus (LCV) is a single stranded, positive strand RNA virus that is solely transmitted by specific whitefly vectors (Bemisia tabaci biotypes A and B) but not by mechanical leaf-rub inoculation. The roles of viral encoded proteins involved in the infection cycle of LCV have not yet been characterized due to the lack of reverse genetic tools. We present here a report of the successful development of an Agrobacterium-mediated inoculation system for the cloned cDNA constructs of LCV. The cDNAs of both LCV RNAs 1 and 2 were engineered into binary vectors in which the expression of LCV RNAs was regulated under a Cauliflower mosaic virus (CaMV) 35S promoter. In addition, by engineering the sequence elements of the Hepatitis delta virus ribozyme and the nopaline synthase 3' untranslated region immediately downstream of the last nucleotide of LCV RNAs 1 and 2 in the binary vector constructs, the in planta produced LCV transcripts were expected to bear authentic 3' termini. Both constructs were transformed into Agrobacterium tumefaciens cells and infiltrated in Nicotiana benthamiana plants. Three to four weeks post-agroinoculation, the N. benthamiana plants developed typical interveinal chlorosis and LCV infection was detected in the systemic leaves by reverse transcription-PCR. Virions purified from the LCV-infected N. benthamiana plants were flexuous rod-shaped and were transmissible by both B. tabaci biotypes A and B following membrane feeding. These results support the conclusion that Agrobacterium-mediated inoculation of LCV binary vectors in N. benthamiana plants results in LCV infection and the production of biologically active, whitefly transmissible virions. This system represents an important tool for use with reverse genetics designed for the study of LCV gene functions.
Collapse
Affiliation(s)
- Angel Y S Chen
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521, United States
| | | | | |
Collapse
|
40
|
Abstract
Cucurbit crops may be affected by at least 28 different viruses in the Mediterranean basin. Some of these viruses are widely distributed and cause severe yield losses while others are restricted to limited areas or specific crops, and have only a negligible economic impact. A striking feature of cucurbit viruses in the Mediterranean basin is their always increasing diversity. Indeed, new viruses are regularly isolated and over the past 35 years one "new" cucurbit virus has been reported on average every 2 years. Among these "new" viruses some were already reported in other parts of the world, but others such as Zucchini yellow mosaic virus (ZYMV), one of the most severe cucurbit viruses and Cucurbit aphid-borne yellows virus (CABYV), one of the most prevalent cucurbit viruses, were first described in the Mediterranean area. Why this region may be a potential "hot-spot" for cucurbit virus diversity is not fully known. This could be related to the diversity of cropping practices, of cultivar types but also to the important commercial exchanges that always prevailed in this part of the world. This chapter describes the major cucurbit viruses occurring in the Mediterranean basin, discusses factors involved in their emergence and presents options for developing sustainable control strategies.
Collapse
Affiliation(s)
- Hervé Lecoq
- INRA, UR407 Pathologie Végétale, Domaine Saint Maurice, Montfavet, France
| | | |
Collapse
|
41
|
A virus capsid component mediates virion retention and transmission by its insect vector. Proc Natl Acad Sci U S A 2011; 108:16777-82. [PMID: 21930903 DOI: 10.1073/pnas.1109384108] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Numerous pathogens of humans, animals, and plants are transmitted by specific arthropod vectors. However, understanding the mechanisms governing these pathogen-vector interactions is hampered, in part, by the lack of easy-to-use analytical tools. We investigated whitefly transmission of Lettuce infectious yellows virus (LIYV) by using a unique immunofluorescent localization approach in which we fed virions or recombinant virus capsid components to whiteflies, followed by feeding them antibodies to the virions or capsid components, respectively. Fluorescent signals, indicating the retention of virions, were localized in the anterior foregut or cibarium of a whitefly vector biotype but not within those of a whitefly nonvector biotype. Retention of virions in these locations strongly corresponded with the whitefly vector transmission of LIYV. When four recombinant LIYV capsid components were individually fed to whitefly vectors, significantly more whiteflies retained the recombinant minor coat protein (CPm). As demonstrated previously and in the present study, whitefly vectors failed to transmit virions preincubated with anti-CPm antibodies but transmitted virions preincubated with antibodies recognizing the major coat protein (CP). Correspondingly, the number of insects that specifically retained virions preincubated with anti-CPm antibodies were significantly reduced compared with those that specifically retained virions preincubated with anti-CP antibodies. Notably, a transmission-defective CPm mutant was deficient in specific virion retention, whereas the CPm-restored virus showed WT levels of specific virion retention and transmission. These data provide strong evidence that transmission of LIYV is determined by a CPm-mediated virion retention mechanism in the anterior foregut or cibarium of whitefly vectors.
Collapse
|
42
|
Ng JCK, Chen AYS. Acquisition of Lettuce infectious yellows virus by Bemisia tabaci perturbs the transmission of Lettuce chlorosis virus. Virus Res 2011; 156:64-71. [PMID: 21211541 DOI: 10.1016/j.virusres.2010.12.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 12/24/2010] [Accepted: 12/24/2010] [Indexed: 11/23/2022]
Abstract
Viruses in the genus Crinivirus infect diverse plant species and are transmitted by specific whitefly vectors, but the basis for vector specific transmission remains poorly understood. Here, we demonstrated that purified virion preparations of Lettuce chlorosis virus (LCV) contained filamentous particles that were consistently transmitted to plants by whiteflies (Bemisia tabaci biotypes A and B) following membrane feeding, suggesting that the preparations contained biologically active virions with all the components essential for specific vector transmission. We also demonstrated in sequential membrane feeding experiments that B. tabaci biotype A pre-fed with high concentrations of Lettuce infectious yellows virus (LIYV) virions followed by decreasing concentrations of LCV virions either abolished or interfered with the transmission of the latter. However, in the reverse treatment, an abolishment/interference in transmission of LIYV was not observed. These results suggest that both viruses share a common transmission pathway in B. tabaci biotype A, and factors other than virion quality and quantity may additionally influence their transmission. To begin investigating the viral determinants that are involved in mediating the whitefly transmission of LCV, virions were analyzed by Western immunoblotting. Our results showed that virions were positively identified by antisera produced against three E. coli expressed recombinant LCV capsid proteins--the major coat protein [CP], minor CP [CPm], and P60.
Collapse
Affiliation(s)
- James C K Ng
- Dept. Plant Pathology and Microbiology, University of California, Riverside, CA 92521, United States.
| | | |
Collapse
|