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Shakir S, Mubin M, Nahid N, Serfraz S, Qureshi MA, Lee TK, Liaqat I, Lee S, Nawaz-ul-Rehman MS. REPercussions: how geminiviruses recruit host factors for replication. Front Microbiol 2023; 14:1224221. [PMID: 37799604 PMCID: PMC10548238 DOI: 10.3389/fmicb.2023.1224221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/21/2023] [Indexed: 10/07/2023] Open
Abstract
Circular single-stranded DNA viruses of the family Geminiviridae encode replication-associated protein (Rep), which is a multifunctional protein involved in virus DNA replication, transcription of virus genes, and suppression of host defense responses. Geminivirus genomes are replicated through the interaction between virus Rep and several host proteins. The Rep also interacts with itself and the virus replication enhancer protein (REn), which is another essential component of the geminivirus replicase complex that interacts with host DNA polymerases α and δ. Recent studies revealed the structural and functional complexities of geminivirus Rep, which is believed to have evolved from plasmids containing a signature domain (HUH) for single-stranded DNA binding with nuclease activity. The Rep coding sequence encompasses the entire coding sequence for AC4, which is intricately embedded within it, and performs several overlapping functions like Rep, supporting virus infection. This review investigated the structural and functional diversity of the geminivirus Rep.
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Affiliation(s)
- Sara Shakir
- Plant Genetics Lab, Gembloux Agro-Bio Tech, University of Liѐge, Gembloux, Belgium
| | - Muhammad Mubin
- Virology Lab, Center for Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad, Faisalabad, Pakistan
| | - Nazia Nahid
- Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, Pakistan
| | - Saad Serfraz
- Virology Lab, Center for Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad, Faisalabad, Pakistan
| | - Muhammad Amir Qureshi
- Department of Integrative Biotechnology, Sungkyunkwan University, Suwon, Republic of Korea
| | - Taek-Kyun Lee
- Risk Assessment Research Center, Korea Institute of Ocean Science and Technology, Geoje, Republic of Korea
| | - Iram Liaqat
- Microbiology Lab, Department of Zoology, Government College University, Lahore, Pakistan
| | - Sukchan Lee
- Department of Integrative Biotechnology, Sungkyunkwan University, Suwon, Republic of Korea
| | - Muhammad Shah Nawaz-ul-Rehman
- Virology Lab, Center for Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad, Faisalabad, Pakistan
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Kumar S, Gupta N, Chakraborty S. Geminiviral betasatellites: critical viral ammunition to conquer plant immunity. Arch Virol 2023; 168:196. [PMID: 37386317 DOI: 10.1007/s00705-023-05776-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 03/30/2023] [Indexed: 07/01/2023]
Abstract
Geminiviruses have mastered plant cell modulation and immune invasion to ensue prolific infection. Encoding a relatively small number of multifunctional proteins, geminiviruses rely on satellites to efficiently re-wire plant immunity, thereby fostering virulence. Among the known satellites, betasatellites have been the most extensively investigated. They contribute significantly to virulence, enhance virus accumulation, and induce disease symptoms. To date, only two betasatellite proteins, βC1, and βV1, have been shown to play a crucial role in virus infection. In this review, we offer an overview of plant responses to betasatellites and counter-defense strategies deployed by betasatellites to overcome those responses.
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Affiliation(s)
- Sunil Kumar
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Neha Gupta
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Supriya Chakraborty
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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Srivastava A, Pandey V, Al-Sadi AM, Shahid MS, Gaur R. An Insight into Emerging Begomoviruses and their Satellite Complex causing Papaya Leaf Curl Disease. Curr Genomics 2023; 24:2-17. [PMID: 37920727 PMCID: PMC10334704 DOI: 10.2174/1389202924666230207111530] [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: 09/29/2022] [Revised: 01/02/2023] [Accepted: 01/27/2023] [Indexed: 02/10/2023] Open
Abstract
Papaya leaf curl disease (PaLCD) was primarily detected in India and causes major economic damage to agriculture crops grown globally, seriously threatening food security. Begomoviruses are communicated by the vector Bemisia tabaci, and their transmission efficiency and persistence in the vector are the highest, exhibiting the widest host range due to adaptation and evolution. Symptoms induced during PaLCD include leaf curl, leaf yellowing, interveinal chlorosis, and reduced fruit quality and yield. Consequently, plants have evolved several multi-layered defense mechanisms to resist Begomovirus infection and distribution. Subsequently, Begomovirus genomes organise circular ssDNA of size ~2.5-2.7 kb of overlapping viral transcripts and carry six-seven ORFs encoding multifunctional proteins, which are precisely evolved by the viruses to maintain the genome-constraint and develop complex but integrated interactions with a variety of host components to expand and facilitate successful infection cycles, i.e., suppression of host defense strategies. Geographical distribution is continuing to increase due to the advent and evolution of new Begomoviruses, and sweep to new regions is a future scenario. This review summarizes the current information on the biological functions of papaya-infecting Begomoviruses and their encoded proteins in transmission through vectors and modulating host-mediated responses, which may improve our understanding of how to challenge these significant plant viruses by revealing new information on the development of antiviral approaches against Begomoviruses associated with PaLCD.
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Affiliation(s)
- Aarshi Srivastava
- Department of Biotechnology, D.D.U. Gorakhpur University, Gorakhpur, India
| | - Vineeta Pandey
- Department of Biotechnology, D.D.U. Gorakhpur University, Gorakhpur, India
| | - Abdullah. M. Al-Sadi
- Department of Plant Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, Al-Khod, Oman
| | - Muhammad S. Shahid
- Department of Plant Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, Al-Khod, Oman
| | - R.K. Gaur
- Department of Biotechnology, D.D.U. Gorakhpur University, Gorakhpur, India
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Gnanasekaran P, Gupta N, Ponnusamy K, Devendran R, George B, Chakraborty S. Betasatellite-encoded βC1 protein regulates helper virus accumulation by interfering with the ATP hydrolysis activity of geminivirus-encoded replication initiator protein. J Gen Virol 2023; 104. [PMID: 37326617 DOI: 10.1099/jgv.0.001866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023] Open
Abstract
Geminivirus-betasatellite disease complexes are an epidemic threat to the majority of economically important crops across the world. Plant virus satellites including betasatellites are maintained by their associated helper virus. Geminivirus-betasatellites influence viral pathogenesis by substantially increasing or decreasing their helper virus accumulation. In the present study, we attempted to understand the mechanistic details of the geminivirus-betasatellite interaction. Here, we used tomato leaf curl Gujarat virus (ToLCGV) and tomato leaf curl Patna betasatellite (ToLCPaB) as a model system. This study reveals that ToLCGV can efficiently trans-replicate ToLCPaB in Nicotiana benthamiana plants, but ToLCPaB greatly reduced the accumulation of its helper virus DNA. For the first time, we have identified that the ToLCPaB-encoded βC1 protein is able to interact with ToLCGV-encoded replication initiator protein (Rep). In addition, we demonstrate that the C-terminal region of βC1 interacts with the C-terminus of Rep (RepC) protein. Our previous study had established that βC1 proteins encoded by diverse betasatellites possess a novel ATP hydrolysis activity and the conserved lysine/arginine residues at positions 49 and 91 are necessary for this function. Here, we show that mutating lysine at positions 49 to alanine of βC1 (βC1K49A) protein did not affect its ability to interact with RepC protein. Biochemical studies performed with ATP hydrolysis activity-deficient K49A mutated βC1 (βC1K49A) and RepC proteins revealed that Rep-βC1 interaction interferes with the ATP hydrolysis activity of Rep protein. Further, we demonstrate that βC1 protein is able to interact with D227A and D289A mutated RepC proteins but not with D262A, K272A or D286A mutated RepC proteins, suggesting that the βC1-interacting region of Rep protein encompasses its Walker-B and B' motifs. The results of docking studies supported that the βC1-interacting region of Rep protein encompasses its motifs associated with ATP binding and ATP hydrolysis activities. Docking studies also provided evidence that the Rep-βC1 interaction interferes with the ATP binding activity of Rep protein. Together, our findings suggest that βC1 protein regulates helper virus accumulation by interfering with the ATP hydrolysis activity of helper virus Rep protein.
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Affiliation(s)
- Prabu Gnanasekaran
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi-110 067, India
| | - Neha Gupta
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi-110 067, India
| | - Kalaiarasan Ponnusamy
- Biotechnology Division, National Centre for Disease Control, New Delhi-110 054, India
| | - Ragunathan Devendran
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi-110 067, India
| | - Biju George
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi-110 067, India
| | - Supriya Chakraborty
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi-110 067, India
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Venkataravanappa V, Ashwathappa KV, Kallingappa P, Shridhar H, Hemachandra Reddy P, Reddy MK, Reddy CNL. Diversity and phylogeography of begomoviruses and DNA satellites associated with the leaf curl and mosaic disease complex of eggplant. Microb Pathog 2023; 180:106127. [PMID: 37119939 DOI: 10.1016/j.micpath.2023.106127] [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: 01/12/2023] [Revised: 04/25/2023] [Accepted: 04/26/2023] [Indexed: 05/01/2023]
Abstract
Eggplant is one of the important vegetable crops grown across the world, and its production is threatened by both biotic and abiotic stresses. Diseases caused by viruses are becoming major limiting factors for its successful cultivation. A survey for begomovirus-like symptoms in 72 eggplant fields located in six different Indian states revealed a prevalence of disease ranging from 5.2 to 40.2%, and the symptoms recorded were mosaic, mottling, petiole bending, yellowing, and upward curling, vein thickening, and enation of the leaves, and stunting of plants. The causal agent associated with these plants was transmitted from infected leaf samples to healthy eggplant seedlings via grafting and whiteflies (Bemisia tabaci). The presence of begomovirus was confirmed in 72 infected eggplant samples collected from the surveyed fields exhibiting leaf curl and mosaic disease by PCR using begomovirus specifc primers (DNA-A componet), which resulted in an expected amplicon of 1.2 kb. The partial genome sequence obtained from amplified 1.2 kb from all samples indicated that they are closely related begomovirus species, tomato leaf Karnataka virus (ToLCKV, two samples), tomato leaf curl Palampur virus (ToLCPalV, fifty eggplant samples), and chilli leaf curl virus (ChLCuV, twenty samples). Based on the partial genome sequence analysis, fourteen representative samples were selected for full viral genome amplification by the rolling circle DNA amplification (RCA) technique. Analyses of fourteen eggplant isolates genome sequences using the Sequence Demarcation Tool (SDT) indicated that one isolate had the maximum nucleotide (nt) identity with ToLCKV and eight isolates with ToLCPalV. Whereas, four isolates four isolates (BLC1-CH, BLC2-CH, BLC3-CH, BLC4-CH) are showing nucleotide identity of less than 91% with chilli infecting viruses begomoviruses with chilli infecting begomoviruses and as per the guidelines given by the ICTV study group for the classification of begomoviruses these isolates are considered as one novel begomovirus species, for which name, Eggplant leaf curl Chhattisgarh virus (EgLCuChV) is proposed. For DNA-B component, seven eggplant isolates had the highest nt identity with ToLCPalV infecting other crops. Further, DNA satellites sequence analysis indicated that four betasatellites identified shared maximum nucleotide identity with the tomato leaf curl betasatellite and five alphasatellites shared maximum nucleotide identity with the ageratum enation alphasatellite. Recombination and GC plot analyses indicated that the bulk of begomovirus genome and associated satellites presumably originated from of previously known mono and bipartite begomoviruses and DNA satellites. To the best of our knowledge, this is India's first report of ToLCKV and a noval virus, eggplant leaf curl Chhattisgarh virus associated with eggplant leaf curl disease.
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Affiliation(s)
- V Venkataravanappa
- Indian Institute of Horticultural Research, Hessaraghatta Lake PO, Bangalore, 560089, Karnataka, India.
| | - K V Ashwathappa
- Indian Institute of Horticultural Research, Hessaraghatta Lake PO, Bangalore, 560089, Karnataka, India
| | | | - Hiremath Shridhar
- Department of Plant Pathology, College of Agriculture, University of Agricultural Sciences, GKVK, Bengaluru, 560 065, Karnataka, India
| | - P Hemachandra Reddy
- Indian Institute of Horticultural Research, Hessaraghatta Lake PO, Bangalore, 560089, Karnataka, India
| | - M Krishna Reddy
- Indian Institute of Horticultural Research, Hessaraghatta Lake PO, Bangalore, 560089, Karnataka, India
| | - C N Lakshminarayana Reddy
- Department of Plant Pathology, College of Agriculture, University of Agricultural Sciences, GKVK, Bengaluru, 560 065, Karnataka, India.
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Fiallo-Olivé E, Navas-Castillo J. The Role of Extensive Recombination in the Evolution of Geminiviruses. Curr Top Microbiol Immunol 2023; 439:139-166. [PMID: 36592245 DOI: 10.1007/978-3-031-15640-3_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Mutation, recombination and pseudo-recombination are the major forces driving the evolution of viruses by the generation of variants upon which natural selection, genetic drift and gene flow can act to shape the genetic structure of viral populations. Recombination between related virus genomes co-infecting the same cell usually occurs via template swapping during the replication process and produces a chimeric genome. The family Geminiviridae shows the highest evolutionary success among plant virus families, and the common presence of recombination signatures in their genomes reveals a key role in their evolution. This review describes the general characteristics of members of the family Geminiviridae and associated DNA satellites, as well as the extensive occurrence of recombination at all taxonomic levels, from strain to family. The review also presents an overview of the recombination patterns observed in nature that provide some clues regarding the mechanisms involved in the generation and emergence of recombinant genomes. Moreover, the results of experimental evolution studies that support some of the conclusions obtained in descriptive or in silico works are summarized. Finally, the review uses a number of case studies to illustrate those recombination events with evolutionary and pathological implications as well as recombination events in which DNA satellites are involved.
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Affiliation(s)
- Elvira Fiallo-Olivé
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Consejo Superior de Investigaciones Científicas, Avenida Dr. Wienberg s/n, 29750, Algarrobo-Costa, Málaga, Spain
| | - Jesús Navas-Castillo
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Consejo Superior de Investigaciones Científicas, Avenida Dr. Wienberg s/n, 29750, Algarrobo-Costa, Málaga, Spain.
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7
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Natural occurrence of mesta yellow vein mosaic virus and DNA-satellites in ornamental sunflower ( Helianthus spp.) in Pakistan. Saudi J Biol Sci 2021; 28:6621-6630. [PMID: 34764778 PMCID: PMC8568841 DOI: 10.1016/j.sjbs.2021.07.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/07/2021] [Accepted: 07/11/2021] [Indexed: 11/23/2022] Open
Abstract
Weeds and ornamental plants serve as a reservoir for geminiviruses and contribute to their dissemination, genome recombination and/or satellite capture. Ornamental sunflower (Helianthus spp.) plants exhibiting mild leaf curl symptoms were subjected to begomovirus and DNA-satellites isolation. The full-length genome of the isolated begomovirus clone (Od1-A) showed 96.8% nucleotide (nt) sequence identity with mesta yellow vein mosaic virus (MeYVMV; accession no. FR772081) whereas, alphasatellite (Od1-a) and betasatellite (Od1-b) clones showed their highest nt sequence identities at 97.4% and 98.2% with ageratum enation alphasatellite (AEA; accession no. FR772085) and papaya leaf curl betasatellite (PaLCuB; accession. no. LN878112), respectively. The evolutionary relationships, average evolutionary divergence and the recombination events were also inferred. The MeYVMV exhibited 9.5% average evolutionary divergence and its CP and Rep had 9.3% and 12.2%, concomitantly; the alphasatellite and the betasatellite had 8.3% and 5.2%, respectively. The nt substitution rates (site-1 year−1) were found to be 6.983 × 10-04 and 5.702 × 10-05 in the CP and Rep of MeYVMV, respectively. The dN/dS ratio and the Tajima D value of MeYVMV CP demonstrated its possible role in host switching. The absolute quantification of the begomovirus demonstrated that mild symptoms might have a correlation with low virus titer. This is the first identification of MeYVMV and associated DNA-satellites from ornamental sunflower in Pakistan. The role of sequence divergence, recombination and importance of MeYVMV along with DNA-satellites in extending its host range is discussed.
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Dokka N, Mahajan MM, Sahu B, Marathe A, Singh HK, Sivalingam PN. Molecular analysis, infectivity and host range of Tomato leaf curl Karnataka virus associated with Corchorus yellow vein mosaic betasatellite. Virus Res 2021; 303:198521. [PMID: 34314770 DOI: 10.1016/j.virusres.2021.198521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/16/2021] [Accepted: 07/21/2021] [Indexed: 11/21/2022]
Abstract
Severe leaf curl disease of tomato (ToLCD) was noticed recently in the central parts of India and is an emerging threat to the cultivation of tomato. The genomic components of the begomovirus isolate, DNA A and betasatellite associated with ToLCD were cloned by rolling circle amplification method and sequenced. The sequence analysis revealed that the DNA A (2766 nt) of this isolate had the nucleotide identity of >91% with other strains of Tomato leaf curl Karnataka virus (ToLCKV), hence this isolate is proposed as a strain of ToLCKV, named as ToLCKV-Raipur. Similarly, the betasatellite molecule (1355 nt) had the highest identity of 91.1% with Corchorus yellow vein mosaic betasatellite (CoYVMB) and named as CoYVMB-Raipur. The full-length dimerized clones of these two genomic components were agroinoculated on natural (tomato), experimental (Nicotiana benthamiana) hosts and other 20 plant species belong to six different families. The severe leaf curl symptoms appeared only in the hosts, N. benthamiana, and in tomato inoculated with ToLCKV-Raipur alone and ToLCKV-Raipur with CoYVMB-Raipur after 8 and 16-18 days inoculation, respectively. This isolate was also transmissible to healthy tomato plants by whitefly from the tomato plant agroinoculated with ToLCKV-Raipur alone and with CoYVMB-Raipur and produced symptoms within 14-16 days after inoculation. Interestingly, this isolate infects horse gram and chilli by whitefly transmission and both the hosts showed positive for DNA A alone but not for betasatellite. Quantification of the genomic components of this isolate with the agroinoculated N. benthamiana samples by qRT-PCR results showed that the quantity of ToLCKV-Raipur was enhanced by three-fold while inoculated with CoYVMB-Raipur compared to ToLCKV-Raipur alone inoculated plants. However, CoYVMB-Raipur did not enhance the levels of ToLCKV-Raipur in the agroinoculated tomato plants. This is the first evidence of the natural co-occurrence of ToLCKV with betasatellite, CoYVMB causing ToLCD.
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Affiliation(s)
- Narasimham Dokka
- ICAR-National Institute of Biotic Stress Management, Baronda, Raipur, Chhattisgarh 493225, India
| | - Mahesh Mohanrao Mahajan
- ICAR-National Institute of Biotic Stress Management, Baronda, Raipur, Chhattisgarh 493225, India
| | - Bhimeshwari Sahu
- ICAR-National Institute of Biotic Stress Management, Baronda, Raipur, Chhattisgarh 493225, India
| | - Ashish Marathe
- ICAR-National Institute of Biotic Stress Management, Baronda, Raipur, Chhattisgarh 493225, India
| | - Harvinder Kumar Singh
- Department of Plant Pathology, Indira Gandhi Krishi Vishwavidyalaya, Raipur, Chhattisgarh 492012, India
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Nigam D. Genomic Variation and Diversification in Begomovirus Genome in Implication to Host and Vector Adaptation. PLANTS (BASEL, SWITZERLAND) 2021; 10:1706. [PMID: 34451752 PMCID: PMC8398267 DOI: 10.3390/plants10081706] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/09/2021] [Accepted: 08/13/2021] [Indexed: 01/02/2023]
Abstract
Begomoviruses (family Geminiviridae, genus Begomovirus) are DNA viruses transmitted in a circulative, persistent manner by the whitefly Bemisia tabaci (Gennadius). As revealed by their wide host range (more than 420 plant species), worldwide distribution, and effective vector transmission, begomoviruses are highly adaptive. Still, the genetic factors that facilitate their adaptation to a diverse array of hosts and vectors remain poorly understood. Mutations in the virus genome may confer a selective advantage for essential functions, such as transmission, replication, evading host responses, and movement within the host. Therefore, genetic variation is vital to virus evolution and, in response to selection pressure, is demonstrated as the emergence of new strains and species adapted to diverse hosts or with unique pathogenicity. The combination of variation and selection forms a genetic imprint on the genome. This review focuses on factors that contribute to the evolution of Begomovirus and their global spread, for which an unforeseen diversity and dispersal has been recognized and continues to expand.
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Affiliation(s)
- Deepti Nigam
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
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Gnanasekaran P, Gupta N, Ponnusamy K, Chakraborty S. Geminivirus Betasatellite-Encoded βC1 Protein Exhibits Novel ATP Hydrolysis Activity That Influences Its DNA-Binding Activity and Viral Pathogenesis. J Virol 2021; 95:e0047521. [PMID: 34132576 PMCID: PMC8354231 DOI: 10.1128/jvi.00475-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/09/2021] [Indexed: 11/20/2022] Open
Abstract
Plant virus satellites are maintained by their associated helper viruses, and satellites influence viral pathogenesis. Diseases caused by geminivirus-betasatellite complexes can become epidemics and therefore have become a threat to economically important crops across the world. Here, we identified a novel molecular function of the betasatellite-encoded pathogenicity determinant βC1. The tomato leaf curl Patna betasatellite (ToLCPaB)-encoded βC1 protein was found to exhibit novel ATPase activity in the presence of the divalent metal ion cofactor MgCl2. Moreover, ATPase activity was confirmed to be ubiquitously displayed by βC1 proteins encoded by diverse betasatellites. Mutational and sequence analysis showed that conserved lysine/arginine residues at positions 49/50 and 91 of βC1 proteins are essential for their ATPase activity. Biochemical studies revealed that the DNA-binding activity of the βC1 protein was interfered with by the binding of ATP to the protein. Mutating arginine 91 of βC1 to alanine reduced its DNA-binding activity. The results of docking studies provided evidence for an overlap of the ATP-binding and DNA-binding regions of βC1 and for the importance of arginine 91 for both ATP-binding and DNA-binding activities. A mutant betasatellite with a specifically βC1-ATPase dominant negative mutation was found to induce symptoms on Nicotiana benthamiana plants similar to those induced by wild-type betasatellite infection. The ATPase function of βC1 was found to be negatively associated with geminivirus-betasatellite DNA accumulation, despite the positive influence of this ATPase function on the accumulation of replication-associated protein (Rep) and βC1 transcripts. IMPORTANCE Most satellites influence the pathogenesis of their helper viruses. Here, we characterized the novel molecular function of βC1, a nonstructural pathogenicity determinant protein encoded by a betasatellite. We demonstrated the display of ATPase activity by this βC1 protein. Additionally, we confirmed the ubiquitous display of ATPase activity by βC1 proteins encoded by diverse betasatellites. The lysine/arginine residues conserved at positions 49 and 91 of βC1 were found to be crucial for its ATPase function. DNA-binding activity of βC1 was found to be reduced in the presence of ATP. Inhibition of ATPase activity of βC1 in the presence of an excess concentration of cold ATP, GTP, CTP, or UTP suggested that the purified βC1 can also hydrolyze other cellular nucleoside triphosphates (NTPs) besides ATP in vitro. These results established the importance of the ATPase and DNA-binding activities of the βC1 protein in regulating geminivirus-betasatellite DNA accumulation in the infected plant cell.
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Affiliation(s)
- Prabu Gnanasekaran
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru Universitygrid.10706.30, New Delhi, India
| | - Neha Gupta
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru Universitygrid.10706.30, New Delhi, India
| | | | - Supriya Chakraborty
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru Universitygrid.10706.30, New Delhi, India
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Gupta N, Reddy K, Bhattacharyya D, Chakraborty✉ S. Plant responses to geminivirus infection: guardians of the plant immunity. Virol J 2021; 18:143. [PMID: 34243802 PMCID: PMC8268416 DOI: 10.1186/s12985-021-01612-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/29/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Geminiviruses are circular, single-stranded viruses responsible for enormous crop loss worldwide. Rapid expansion of geminivirus diversity outweighs the continuous effort to control its spread. Geminiviruses channelize the host cell machinery in their favour by manipulating the gene expression, cell signalling, protein turnover, and metabolic reprogramming of plants. As a response to viral infection, plants have evolved to deploy various strategies to subvert the virus invasion and reinstate cellular homeostasis. MAIN BODY Numerous reports exploring various aspects of plant-geminivirus interaction portray the subtlety and flexibility of the host-pathogen dynamics. To leverage this pool of knowledge towards raising antiviral resistance in host plants, a comprehensive account of plant's defence response against geminiviruses is required. This review discusses the current knowledge of plant's antiviral responses exerted to geminivirus in the light of resistance mechanisms and the innate genetic factors contributing to the defence. We have revisited the defence pathways involving transcriptional and post-transcriptional gene silencing, ubiquitin-proteasomal degradation pathway, protein kinase signalling cascades, autophagy, and hypersensitive responses. In addition, geminivirus-induced phytohormonal fluctuations, the subsequent alterations in primary and secondary metabolites, and their impact on pathogenesis along with the recent advancements of CRISPR-Cas9 technique in generating the geminivirus resistance in plants have been discussed. CONCLUSIONS Considering the rapid development in the field of plant-virus interaction, this review provides a timely and comprehensive account of molecular nuances that define the course of geminivirus infection and can be exploited in generating virus-resistant plants to control global agricultural damage.
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Affiliation(s)
- Neha Gupta
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Kishorekumar Reddy
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Dhriti Bhattacharyya
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Supriya Chakraborty✉
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
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12
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Baig MS, Akhtar S, Khan JA. Engineering tolerance to CLCuD in transgenic Gossypium hirsutum cv. HS6 expressing Cotton leaf curl Multan virus-C4 intron hairpin. Sci Rep 2021; 11:14172. [PMID: 34238948 PMCID: PMC8266814 DOI: 10.1038/s41598-021-93502-3] [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: 09/26/2020] [Accepted: 06/16/2021] [Indexed: 11/25/2022] Open
Abstract
Cotton leaf curl disease (CLCuD), caused by begomoviruses in combination with betasatellite molecule, has adversely affected cotton industry of Indian subcontinent. To devise a CLCuD-control strategy, RNAi-mediated approach was followed in this study. Gossypium hirsutum cv. HS6 plants were transformed with intron-hairpin RNAi (ihpRNAi-C4) construct carrying silencing suppressor C4 gene of Cotton leaf curl Multan virus (CLCuMuV). Efficacy of the construct in imparting CLCuD resistance was evaluated in transgenic (T0, T1) cotton lines. Accumulation of CLCuMuV/betasatellite and attenuation of CLCuD symptoms in the transgenic lines were monitored at different times interval after virus inoculation. Northern hybridization revealed the expression of C4-gene derived siRNA. Expression of the ihpRNAi transcript was recorded higher in transgenic lines expressing siRNA which supposedly targeted the C4 gene. A significant delay in detection of virus as well as betasatellite was observed in the transgenic lines. At 30 days post inoculation (dpi), none of the lines tested positive. At 45 dpi, however, it could be detected in few lines having much lower titre as compared to non-transformed control plants. Notably, till 60 dpi, no significant progression of the virus/betasatellite DNA was observed and the plants did not exhibit any characteristic CLCuD symptoms. A tolerance phenomenon leading to escape of CLCuD symptoms in the transformed cotton was described.
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Affiliation(s)
- Mirza S Baig
- Department of Biosciences, Jamia Millia Islamia (Central University), Jamia Nagar, New Delhi, 110025, India
- Department of Molecular Medicine, Jamia Hamdard, Hamdard Nagar, New Delhi, 110062, India
| | - Sadia Akhtar
- Department of Biosciences, Jamia Millia Islamia (Central University), Jamia Nagar, New Delhi, 110025, India
| | - Jawaid A Khan
- Department of Biosciences, Jamia Millia Islamia (Central University), Jamia Nagar, New Delhi, 110025, India.
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Revealing the Complexity of Sweepovirus-Deltasatellite-Plant Host Interactions: Expanded Natural and Experimental Helper Virus Range and Effect Dependence on Virus-Host Combination. Microorganisms 2021; 9:microorganisms9051018. [PMID: 34068583 PMCID: PMC8150397 DOI: 10.3390/microorganisms9051018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 11/16/2022] Open
Abstract
Sweepoviruses are begomoviruses (genus Begomovirus, family Geminiviridae) with ssDNA genomes infecting sweet potato and other species of the family Convolvulaceae. Deltasatellites (genus Deltasatellite, family Tolecusatellitidae) are small-size non-coding DNA satellites associated with begomoviruses. In this study, the genetic diversity of deltasatellites associated with sweepoviruses infecting Ipomoea indica plants was analyzed by further sampling the populations where the deltasatellite sweet potato leaf curl deltasatellite 1 (SPLCD1) was initially found, expanding the search to other geographical areas in southern continental Spain and the Canary Islands. The sweepoviruses present in the samples coinfected with deltasatellites were also fully characterized by sequencing in order to define the range of viruses that could act as helper viruses in nature. Additionally, experiments were performed to assess the ability of a number of geminivirids (the monopartite tomato leaf deformation virus and the bipartite NW begomovirus Sida golden yellow vein virus, the bipartite OW begomovirus tomato leaf curl New Delhi virus, and the curtovirus beet curly top virus) to transreplicate SPLCD1 in their natural plant hosts or the experimental host Nicotiana benthamiana. The results show that SPLCD1 can be transreplicated by all the geminivirids assayed in N. benthamiana and by tomato leaf curl New Delhi virus in zucchini. The presence of SPLCD1 did not affect the symptomatology caused by the helper viruses, and its effect on viral DNA accumulation depended on the helper virus-host plant combination.
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14
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Arif M, Atta S, Bashir MA, Hussain A, Khan MI, Farooq S, Hannan A, Islam SU, Umar UUD, Khan M, Lin W, Hashem M, Alamri S, Wu Z. Molecular characterization and RSV Co-infection of Nicotiana benthamiana with three distinct begomoviruses. Methods 2020; 183:43-49. [PMID: 31759050 DOI: 10.1016/j.ymeth.2019.11.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/10/2019] [Accepted: 11/16/2019] [Indexed: 12/31/2022] Open
Abstract
Geminiviruses constitute a family of plant viruses with characteristic twinned quasi-icosahedral virions and a small circular DNA genome. Geminiviruses, especially begomoviruses, cause substantial economic losses in tropical and subtropical regions globally. Geminiviruses use the host's transcriptional mechanisms to synthesize their mRNAs. They are considered as an attractive model to understand the transcription mechanism of their host plants. Experiments were conducted to identify transcriptional start sites (TSSs) of the three begomoviruses, i.e., Cotton leaf curl Multan virus (CLCuMuV), Corchorus yellow vein virus (CoYVV), and Ramie mosaic virus (RamV). We first rub-inoculated Rice stripe tenuivirus (RSV), a segmented negative-sense RNA virus that uses cap-snatching to produce capped viral mRNAs, into N. benthamiana. After the inoculation, RSV-infected N. benthamiana were super-infected by CoYVV, CLCuMuV, or RamV, respectively. The capped-RNA leaders snatched by RSV were obtained by determining the 5'-ends of RSV mRNA with high throughput sequencing. Afterwards, snatched capped-RNA leaders of RSV were mapped onto the genome of each begomovirus and those matching the begomoviral genome were considered to come from the 5' ends of assumed begomoviral mRNAs. In this way, TSSs of begomoviruses were obtained. After mapping these TSSs onto the genome of the respective begomovirus, it was found very commonly that a begomovirus can use many different TSSs to transcribe the same gene, producing many different mRNA isoforms containing the corresponding open reading frames (ORFs).
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Affiliation(s)
- Muhammad Arif
- Fujian Province Key Laboratory of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China; Department of Plant Protection, Faculty of Agricultural Sciences, Ghazi University, Dera Ghazi Khan, Punjab 32200, Pakistan; Department of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China.
| | - Sagheer Atta
- Department of Plant Protection, Faculty of Agricultural Sciences, Ghazi University, Dera Ghazi Khan, Punjab 32200, Pakistan
| | - Muhammad Amjad Bashir
- Department of Plant Protection, Faculty of Agricultural Sciences, Ghazi University, Dera Ghazi Khan, Punjab 32200, Pakistan
| | - Ansar Hussain
- Department of Plant Breeding and Genetics, Faculty of Agricultural Sciences, Ghazi University, Dera Ghazi Khan, Punjab 32200, Pakistan
| | - Muhammad Ifnan Khan
- Department of Plant Breeding and Genetics, Faculty of Agricultural Sciences, Ghazi University, Dera Ghazi Khan, Punjab 32200, Pakistan
| | - Shahid Farooq
- Department of Plant Protection, Faculty of Agriculture, Harran University, Sanliurfa 63200, Turkey
| | - Abdul Hannan
- Department of Botany, Ghazi University, Dera Ghazi Khan, Punjab 32200, Pakistan
| | - Saif Ul Islam
- Department of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Ummad Ud Din Umar
- Department of Plant Pathology, Bahauddin Zakariya University, Multan, Punjab 60800, Pakistan
| | - Mehran Khan
- Department of Plant Protection, Faculty of Agricultural Sciences, Ghazi University, Dera Ghazi Khan, Punjab 32200, Pakistan
| | - Wenzhong Lin
- Fujian Province Key Laboratory of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China; Department of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Mohamed Hashem
- King Khalid University, College of Science, Department of Biology, Abha 61413, Saudi Arabia; Assiut University, Faculty of Science, Botany and Microbiology Department, Assiut, Egypt
| | - Saad Alamri
- King Khalid University, College of Science, Department of Biology, Abha 61413, Saudi Arabia; Research Center for Advanced Materials Science (RCAMS), King Khalid University, Abha 61413, Saudi Arabia
| | - Zujian Wu
- Fujian Province Key Laboratory of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China; Department of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China.
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15
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Hu T, Song Y, Wang Y, Zhou X. Functional analysis of a novel βV1 gene identified in a geminivirus betasatellite. SCIENCE CHINA. LIFE SCIENCES 2020; 63:688-696. [PMID: 32107688 DOI: 10.1007/s11427-020-1654-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 02/17/2020] [Indexed: 02/07/2023]
Abstract
Betasatellites (DNA β) are circular ssDNA molecules that are associated with monopartite geminiviruses and exert a positive effect on the viral infection. Betasatellites encode one protein, named βC1, on the complementary strand; βC1 functions as a pathogenicity factor and RNA silencing suppressor. In this report, we describe the identification of another betasatellite-encoded protein, βVl, which also contributes to symptom development. The βVl open reading frame can be found on the viral strand of approximately 40% of reported betasatellite sequences, and is conserved in position and sequence. The presence of the βVl transcript was observed in plants infected with Tomato yellow leaf curl China virus (TYTCCNV) along with its associated betasatellite Tomato yellow leaf curl China betasatellite (TYTCCNB). Mutant viruses unable to produce βVl showed reduced virulence and decreased viral load. Ectopic expression of the TYTCCNB-PV1 gene in Nicotiana benthamiana plants from a PVX-based vector resulted in leaf mosaic and chlorosis. We further demonstrated that the βVl protein could elicit hypersensitive response (HR)-type cell death in N. benthamiana leaves. Our results uncover a novel betasatellite-encoded protein that contributes to the virus infection, and this discover gives us a more complete view of the plant-geminivirus interaction landscape.
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Affiliation(s)
- Tao Hu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Yu Song
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Yaqin Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
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16
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Mubin M, Ijaz S, Nahid N, Hassan M, Younus A, Qazi J, Nawaz-Ul-Rehman MS. Journey of begomovirus betasatellite molecules: from satellites to indispensable partners. Virus Genes 2019; 56:16-26. [PMID: 31773493 DOI: 10.1007/s11262-019-01716-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 11/17/2019] [Indexed: 12/21/2022]
Abstract
Betasatellites are a group of circular, single-stranded DNA molecules that are frequently found to be associated with monopartite begomoviruses of the family Geminiviridae. Betasatellites require their helper viruses for replication, movement, and encapsidation and they are often essential for induction of typical disease symptoms. The βC1 protein encoded by betasatellites is multifunctional that participates in diverse cellular events. It interferes with several cellular processes like normal development, chloroplasts, and innate immune system of plants. Recent research has indicated βC1 protein interaction with cellular proteins and its involvement in modulation of the host's cell cycle and symptom determination. This article focuses on the functional mechanisms of βC1 and its interactions with other viral and host proteins.
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Affiliation(s)
- Muhammad Mubin
- Virology Lab, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Sehrish Ijaz
- Virology Lab, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Nazia Nahid
- Department of Bioinformatics and Biotechnology, GC University Faisalabad, Faisalabad, Pakistan
| | - Muhammad Hassan
- Virology Lab, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Ayesha Younus
- Laser Matter Interaction and Nano-sciences Lab, Department of Physics, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Javaria Qazi
- Department of Biotechnology, Quaid e Azam University, Islamabad, Pakistan
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17
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Gnanasekaran P, KishoreKumar R, Bhattacharyya D, Vinoth Kumar R, Chakraborty S. Multifaceted role of geminivirus associated betasatellite in pathogenesis. MOLECULAR PLANT PATHOLOGY 2019; 20:1019-1033. [PMID: 31210029 PMCID: PMC6589721 DOI: 10.1111/mpp.12800] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Begomoviruses have emerged as a group of plant pathogens that cause devastating diseases in a wide range of crops in tropical and subtropical regions of the world. Betasatellites, the circular single-stranded DNA molecules with the size of almost half of that of the associated helper begomoviruses, are often essential for the production of typical disease symptoms in several virus-host systems. Association of betasatellites with begomoviruses results in more severe symptoms in the plants and affects the yield of numerous crops leading to huge agroeconomic losses. βC1, the only protein encoded by betasatellites, plays a multifaceted role in the successful establishment of infection. This protein counteracts the innate defence mechanisms of the host, like RNA silencing, ubiquitin-proteasome system and defence responsive hormones. In the last two decades, the molecular aspect of betasatellite pathogenesis has attracted much attention from the researchers worldwide, and reports have shown that βC1 protein aggravates the helper begomovirus disease complex by modulating specific host factors. This review discusses the molecular aspects of the pathogenesis of betasatellites, including various βC1-host factor interactions and their effects on the suppression of defence responses of the plants.
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Affiliation(s)
- Prabu Gnanasekaran
- Molecular Virology Laboratory, School of Life SciencesJawaharlal Nehru UniversityNew Delhi110 067India
| | - Reddy KishoreKumar
- Molecular Virology Laboratory, School of Life SciencesJawaharlal Nehru UniversityNew Delhi110 067India
| | - Dhriti Bhattacharyya
- Molecular Virology Laboratory, School of Life SciencesJawaharlal Nehru UniversityNew Delhi110 067India
| | - R. Vinoth Kumar
- Molecular Virology Laboratory, School of Life SciencesJawaharlal Nehru UniversityNew Delhi110 067India
| | - Supriya Chakraborty
- Molecular Virology Laboratory, School of Life SciencesJawaharlal Nehru UniversityNew Delhi110 067India
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Hamim I, Borth WB, Melzer MJ, Suzuki JY, Wall MM, Hu JS. Occurrence of tomato leaf curl Bangladesh virus and associated subviral DNA molecules in papaya in Bangladesh: molecular detection and characterization. Arch Virol 2019; 164:1661-1665. [PMID: 30949815 DOI: 10.1007/s00705-019-04235-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 02/15/2019] [Indexed: 11/29/2022]
Abstract
Forty-five papaya samples showing severe leaf curl symptoms were tested by PCR with a degenerate primer set for virus species in the genus Begomovirus. Of these, 29 were positive for tomato leaf curl Bangladesh virus (ToLCBV). The complete genome sequences of ToLCBV (GenBank accession no. MH380003) and its associated tomato leaf curl betasatellite (ToLCB) (MH397223) from papaya isolate Gaz17-Pap were determined and characterized. Defective betasatellites were found in ToLCBV-positive papaya isolates Gaz19-Pap, Gaz20-Pap and Gaz21-Pap. This study confirmed that papaya is a host of ToLCBV, ToLCB, and other defective and recombinant DNA satellites in Bangladesh.
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Affiliation(s)
- Islam Hamim
- Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, Honolulu, HI, 96822, USA.,Department of Plant Pathology, Bangladesh Agricultural University, Mymensingh, 2202, Bangladesh
| | - Wayne B Borth
- Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, Honolulu, HI, 96822, USA
| | - Michael J Melzer
- Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, Honolulu, HI, 96822, USA
| | - Jon Y Suzuki
- USDA-ARS, Daniel K. Inouye, U.S. Pacific Basin Agricultural Research Center, 64 Nowelo St., Hilo, HI, 96720, USA
| | - Marisa M Wall
- USDA-ARS, Daniel K. Inouye, U.S. Pacific Basin Agricultural Research Center, 64 Nowelo St., Hilo, HI, 96720, USA
| | - John S Hu
- Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, Honolulu, HI, 96822, USA.
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19
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Xu X, Qian Y, Wang Y, Li Z, Zhou X. Iterons Homologous to Helper Geminiviruses Are Essential for Efficient Replication of Betasatellites. J Virol 2019; 93:e01532-18. [PMID: 30541843 PMCID: PMC6384059 DOI: 10.1128/jvi.01532-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 11/28/2018] [Indexed: 11/20/2022] Open
Abstract
Betasatellites associated with geminiviruses can be replicated promiscuously by distinct geminiviruses but exhibit a preference for cognate helper viruses. However, the cis elements responsible for betasatellite origin recognition have not been characterized. In this study, we identified an iteron-like repeated sequence motif, 5'-GAGGACC-3', in a tobacco curly shoot betasatellite (TbCSB) associated with tobacco curly shoot virus (TbCSV). Competitive DNA binding assays revealed that two core repeats (5'-GGACC-3') are required for specific binding to TbCSV Rep; TbCSB iteron mutants accumulated to greatly reduced levels and lost the cognate helper-mediated replication preference. Interestingly, TbCSV also contains identical repeated sequences that are essential for specific Rep binding and in vivo replication. In order to gain insight into the mechanism by which TbCSB has acquired the cognate iterons, we performed a SELEX (systematic evolution of ligands by exponential enrichment) assay to identify the high-affinity Rep binding ligands from a large pool of randomized sequences. Analysis of SELEX winners showed that all of the sequences contained at least one core iteron-like motif, suggesting that TbCSB has evolved to contain cognate iterons for high-affinity Rep binding. Further analyses of various betasatellite sequences revealed a region upstream of the satellite conserved region replete with iterative sequence motifs, including species-specific repeats and a general repeat (5'-GGTAAAT-3'). Remarkably, the species-specific repeats in many betasatellites are homologous to those in their respective cognate helper begomoviruses, whereas the general repeat is widespread in most of the betasatellite molecules analyzed. These data, taken together, suggest that many betasatellites have evolved to acquire homologous iteron-like sequences for efficient replication mediated by cognate helper viruses.IMPORTANCE The geminivirus-encoded replication initiator protein (Rep) binds to repeated sequence elements (also known as iterons) in the origin of replication that serve as essential cis elements for specific viral replication. Betasatellites associated with begomoviruses can be replicated by cognate or noncognate helper viruses, but the cis elements responsible for betasatellite origin recognition have not been characterized. Using a betasatellite (TbCSB) associated with tobacco curly shoot virus (TbCSV) as a model, we identify two tandem repeats (iterons) in the Rep-binding motif (RBM) that are required for specific Rep binding and efficient replication, and we show that identical iteron sequences present in TbCSV are also necessary for Rep binding and the replication of helper viruses. Extensive analysis of begomovirus/betasatellite sequences shows that many betasatellites contain iteron-like elements homologous to those of their respective cognate helper begomoviruses. Our data suggest that many betasatellites have evolved to acquire homologous iteron-like sequences for efficient replication mediated by cognate helper viruses.
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Affiliation(s)
- Xiongbiao Xu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Yajuan Qian
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Yaqin Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Zhenghe Li
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
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20
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Venkataravanappa V, Reddy CNL, Shankarappa KS, Reddy MK. Association of Tomato Leaf Curl New Delhi Virus, Betasatellite, and Alphasatellite with Mosaic Disease of Spine Gourd ( Momordica dioica Roxb. Willd) in India. IRANIAN JOURNAL OF BIOTECHNOLOGY 2019; 17:e2134. [PMID: 31457044 PMCID: PMC6697862 DOI: 10.21859/ijb.2134] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Background Spine gourd (Momordica dioica Roxb. Willd) is one of the important cucurbitaceous crops grown across the world for vegetable and medicinal purposes. Diseases caused by the DNA viruses are becoming the limiting factors for the production of spine gourd reducing its potential yield. For the commercial cultivation of the spine gourd, propagation material used by most of the growers is tuberous roots and stem cuttings, which in turn results in an increased occurrence of the mosaic disease. There is a need for understanding the causal agent; through characterization of which will lead to the designing management strategies for the spine gourd mosaic disease control. Objectives Characterization of a begomovirus and its satellites associated with mosaic disease on spine gourd. Materials and Methods Total DNA was extracted from spine gourd samples exhibiting symptoms typical to the begomoviruses infection (mosaic mottling, leaf curl) and was tested by PCR using begomovirus specific primers. Furthermore, the complete genome of begomo viruses (DNA A, DNA B, alpha satellite, and beta satellite) was amplified by rolling circle amplification (RCA) method. Results The full-length sequences of DNA A, DNA B, alpha satellite, and beta satellite isolated from symptomatic spine gourd were determined. The full length genomes (DNA A and DNA B) of the Tomato leaf curl New Delhi Virus (ToLCNDV) infecting spine gourd were compared with the other begomovirus genomes available in the data base. The sequence analysis has revealed that DNA A and DNA B components of the begomovirus infecting spine gourd share 95.4-96.2 and 86.7-91.2% identical sequence (i.e., nucleotide (nt) identity) with that of ToLCNDV infecting potato and cucurbits in the Indian subcontinent isolates reported earlier (available in GenBank), respectively. Further, alpha satellite and beta satellite were also detected in the begomovirus infected spine gourd samples. The recombination analysis of the DNA A, DNA B, beta satellite, and alpha satellite of the begomovirus infecting spine gourd showed the associated begomovirus and satellite DNAs were driven from the different begomoviruses, leading to emergence as a new variant of the begomovirus infecting spine gourd. Conclusions The commercial cultivation of the spine gourd by most growers depends on the tuberous roots and stem cutting. The occurrence of begomovirus in spine gourd gives an alarming signal against utilization of such infected plant materials in the crop breeding and improvement programs. Using the clean virus-free vegetative propagation material is considered as one of the most important methods for controlling viral diseases. The study is highly useful for detection of the begomovirus infecting spine gourd in the detection of the virus infection in the clonally propagated planting material.
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Affiliation(s)
- V Venkataravanappa
- Central Horticultural Experiment Station (CHES), Chettalli, Indian Institute of Horticultural Research, Hessaraghatta Lake PO, Bengaluru, India
| | - C N Lakshminarayana Reddy
- Department of Plant Pathology, College of Agriculture, GKVK, University of Agricultural Sciences, Bangalore, Karnataka, India
| | - K S Shankarappa
- Department of Plant Pathology, College of Horticulture, Bengaluru, University of Horticultural Sciences, Bagalkot, Karnataka, India
| | - M Krishna Reddy
- Indian Institute of Horticultural Research, Hessaraghatta Lake PO, Bangalore, Karnataka, India
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21
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Conflon D, Granier M, Tiendrébéogo F, Gentit P, Peterschmitt M, Urbino C. Accumulation and transmission of alphasatellite, betasatellite and tomato yellow leaf curl virus in susceptible and Ty-1-resistant tomato plants. Virus Res 2018; 253:124-134. [PMID: 29908896 DOI: 10.1016/j.virusres.2018.06.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 06/13/2018] [Accepted: 06/13/2018] [Indexed: 11/16/2022]
Abstract
Begomoviruses (family Geminiviridae) are frequently associated with alphasatellites and betasatellites in the Old World. Tomato yellow leaf curl virus, one of the most damaging begomovirus species worldwide, was recently found associated with betasatellites in the eastern coast of the Mediterranean Sea, and in the Middle East region. Tomato yellow leaf curl virus (TYLCV)/betasatellite associations were shown to increase TYLCV virulence in experimental conditions. The sustainability of TYLCV/satellite associations in tomato was assessed here by estimating accumulation levels of satellites in comparison to TYLCV, vector transmission efficiency, and by testing how far the popular Ty-1 resistance gene used in most TYLCV-resistant tomato cultivars in the Mediterranean Basin is effective against betasatellites. Three satellites previously isolated from okra in Burkina Faso-of the species Cotton leaf curl Gezira betasatellite, Cotton leaf curl Gezira alphasatellite and Okra leaf curl Burkina Faso alphasatellite-were shown to accumulate at levels similar to, or higher than, the helper virus TYLCV-Mld in tomato plants from 32 to 150 days post inoculation (dpi). Cotton leaf curl Gezira betasatellite (CLCuGB) reduced TYLCV-Mld accumulation whereas alphasatellites did not. Transmission tests were performed with B. tabaci from plants infected with TYLCV-Mld/CLCuGB- or TYLCV-Mld/Okra leaf curl Burkina Faso alphasatellite. At 32 dpi, both satellites were transmitted to more than 50% of TYLCV-infected test plants. Betasatellite transmission, tested further with 150 dpi source plants was successful in more than 30% of TYLCV-infected test plants. Ty-1 resistant tomato plants co-infected with TYLCV (-Mld or -IL) and CLCuGB exhibited mild leaf curling and mosaic symptoms at the early stage of infection associated with a positive effect on TYLCV-IL accumulation, while resistant plants infected with TYLCV only, were asymptomatic. Together with previous experimental studies, these results further emphasize the potential risk of betasatellites to tomato cultivation, including with Ty-1 resistant cultivars.
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Affiliation(s)
- Déborah Conflon
- CIRAD, UMR BGPI, F-34398, Montpellier, France; BGPI, Univ Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
| | - Martine Granier
- CIRAD, UMR BGPI, F-34398, Montpellier, France; BGPI, Univ Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
| | - Fidèle Tiendrébéogo
- Laboratoire de Virologie et de Biotechnologies Végétales (LVBV), INERA, 01 BP 476, Ouagadougou 01, Burkina Faso; Laboratoire Mixte International Patho-Bios, IRD-INERA, 01 BP 476, Ouagadougou 01, Burkina Faso
| | - Pascal Gentit
- ANSES, Plant Health Laboratory, Unité de Bactériologie, Virologie et détection des OGM, 7 rue Jean Dixméras, 49044, Angers Cedex 01, France
| | - Michel Peterschmitt
- CIRAD, UMR BGPI, F-34398, Montpellier, France; BGPI, Univ Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
| | - Cica Urbino
- CIRAD, UMR BGPI, F-34398, Montpellier, France; BGPI, Univ Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France.
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Iqbal Z, Shafiq M, Ali I, Mansoor S, Briddon RW. Maintenance of Cotton Leaf Curl Multan Betasatellite by Tomato Leaf Curl New Delhi Virus-Analysis by Mutation. FRONTIERS IN PLANT SCIENCE 2017; 8:2208. [PMID: 29312431 PMCID: PMC5744040 DOI: 10.3389/fpls.2017.02208] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 12/15/2017] [Indexed: 06/07/2023]
Abstract
Viruses of the genus Begomovirus (family Geminiviridae) are economically important phytopathogens that are transmitted plant-to-plant by the whitefly Bemisia tabaci. Most Old World (OW) begomoviruses are monopartite and many of these interact with symptoms and host range determining betasatellites. Tomato leaf curl New Delhi virus (ToLCNDV) is one of only a few OW begomoviruses with a bipartite genome (components known as DNA A and DNA B). Four genes [AV2, coat protein (CP), transcriptional-activator protein (TrAP), and AC4] of ToLCNDV were mutated and the effects of the mutations on infectivity, symptoms and the ability to maintain Cotton leaf curl Multan betasatellite (CLCuMuB) were investigated. Infectivity and virus/betasatellite DNA titer were assessed by Southern blot hybridization, PCR, and quantitative PCR. The results showed TrAP of ToLCNDV to be essential for maintenance of CLCuMuB and AV2 to be important only in the presence of the DNA B. AC4 was found to be important for the maintenance of CLCuMuB in the presence of, but indispensable in the absence of, the DNA B. Rather than being required for maintenance, the CP was shown to possibly interfere with maintenance of the betasatellite. The findings show that the interaction between a bipartite begomovirus and a betasatellite is more complex than just trans-replication. Clearly, multiple levels of interactions are present and such associations can cause additional significant losses to crops although the interaction may not be stable.
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Affiliation(s)
- Zafar Iqbal
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan
| | - Muhammad Shafiq
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences, Nilore, Pakistan
| | - Irfan Ali
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan
| | - Shahid Mansoor
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan
| | - Rob W. Briddon
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan
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Zubair M, Zaidi SSEA, Shakir S, Amin I, Mansoor S. An Insight into Cotton Leaf Curl Multan Betasatellite, the Most Important Component of Cotton Leaf Curl Disease Complex. Viruses 2017; 9:E280. [PMID: 28961220 PMCID: PMC5691632 DOI: 10.3390/v9100280] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 09/20/2017] [Accepted: 09/28/2017] [Indexed: 01/18/2023] Open
Abstract
Cotton leaf curl disease (CLCuD) is one of the most economically important diseases and is a constraint to cotton production in major producers, Pakistan and India. CLCuD is caused by monopartite plant viruses belonging to the family Geminiviridae (genus Begomovirus), in association with an essential, disease-specific satellite, Cotton leaf curl Multan betasatellite (CLCuMuB) belonging to a newly-established family Tolecusatellitidae (genus Betasatellite). CLCuMuB has a small genome (ca. 1350 nt) with a satellite conserved region, an adenine-rich region and a single gene that encodes for a multifunctional βC1 protein. CLCuMuB βC1 protein has a major role in pathogenicity and symptom determination, and alters several host cellular functions like autophagy, ubiquitination, and suppression of gene silencing, to assist CLCuD infectivity. Efficient trans-replication ability of CLCuMuB with several monopartite and bipartite begomoviruses, is also associated with the rapid evolution and spread of CLCuMuB. In this article we comprehensively reviewed the role of CLCuMuB in CLCuD, focusing on the βC1 functions and its interactions with host proteins.
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Affiliation(s)
- Muhammad Zubair
- National Institute for Biotechnology and Genetic Engineering, 38000 Faisalabad, Pakistan.
- Pakistan Institute of Engineering and Applied Sciences, Nilore, 45650 Islamabad, Pakistan.
| | - Syed Shan-E-Ali Zaidi
- National Institute for Biotechnology and Genetic Engineering, 38000 Faisalabad, Pakistan.
- Pakistan Institute of Engineering and Applied Sciences, Nilore, 45650 Islamabad, Pakistan.
- AgroBioChem Department, Gembloux Agro-Bio Tech, University of Liège, 5030 Gembloux, Belgium.
| | - Sara Shakir
- National Institute for Biotechnology and Genetic Engineering, 38000 Faisalabad, Pakistan.
- Boyce Thompson Institute, 533 Tower Rd, Ithaca, NY 14853, USA.
| | - Imran Amin
- National Institute for Biotechnology and Genetic Engineering, 38000 Faisalabad, Pakistan.
| | - Shahid Mansoor
- National Institute for Biotechnology and Genetic Engineering, 38000 Faisalabad, Pakistan.
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Hassan I, Orílio AF, Fiallo-Olivé E, Briddon RW, Navas-Castillo J. Infectivity, effects on helper viruses and whitefly transmission of the deltasatellites associated with sweepoviruses (genus Begomovirus, family Geminiviridae). Sci Rep 2016; 6:30204. [PMID: 27453359 PMCID: PMC4958995 DOI: 10.1038/srep30204] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 06/30/2016] [Indexed: 11/08/2022] Open
Abstract
Begomoviruses (family Geminiviridae) are whitefly-transmitted viruses with single-stranded DNA genomes that are frequently associated with DNA satellites. These satellites include non-coding satellites, for which the name deltasatellites has been proposed. Although the first deltasatellite was identified in the late 1990s, little is known about the effects they have on infections of their helper begomoviruses. Recently a group of deltasatellites were identified associated with sweepoviruses, a group of phylogenetically distinct begomoviruses that infect plants of the family Convolvulaceae including sweet potato. In this work, the deltasatellites associated with sweepoviruses are shown to be transreplicated and maintained in plants by the virus with which they were identified, sweet potato leaf curl virus (SPLCV). These deltasatellites were shown generally to reduce symptom severity of the virus infection by reducing virus DNA levels. Additionally they were shown to be maintained in plants, and reduce the symptoms induced by two Old World monopartite begomoviruses, tomato yellow leaf curl virus and tomato yellow leaf curl Sardinia virus. Finally one of the satellites was shown to be transmitted plant-to-plant in the presence of SPLCV by the whitefly vector of the virus, Bemisia tabaci, being the first time a deltasatellite has been shown to be insect transmitted.
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Affiliation(s)
- Ishtiaq Hassan
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga - Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental “La Mayora”, 29750 Algarrobo-Costa, Málaga, Spain
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences, Islamabad, Pakistan
| | - Anelise F. Orílio
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga - Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental “La Mayora”, 29750 Algarrobo-Costa, Málaga, Spain
| | - Elvira Fiallo-Olivé
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga - Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental “La Mayora”, 29750 Algarrobo-Costa, Málaga, Spain
| | - Rob W. Briddon
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan
| | - Jesús Navas-Castillo
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga - Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental “La Mayora”, 29750 Algarrobo-Costa, Málaga, Spain
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Lozano G, Trenado HP, Fiallo-Olivé E, Chirinos D, Geraud-Pouey F, Briddon RW, Navas-Castillo J. Characterization of Non-coding DNA Satellites Associated with Sweepoviruses (Genus Begomovirus, Geminiviridae) - Definition of a Distinct Class of Begomovirus-Associated Satellites. Front Microbiol 2016; 7:162. [PMID: 26925037 PMCID: PMC4756297 DOI: 10.3389/fmicb.2016.00162] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 02/01/2016] [Indexed: 11/13/2022] Open
Abstract
Begomoviruses (family Geminiviridae) are whitefly-transmitted, plant-infecting single-stranded DNA viruses that cause crop losses throughout the warmer parts of the World. Sweepoviruses are a phylogenetically distinct group of begomoviruses that infect plants of the family Convolvulaceae, including sweet potato (Ipomoea batatas). Two classes of subviral molecules are often associated with begomoviruses, particularly in the Old World; the betasatellites and the alphasatellites. An analysis of sweet potato and Ipomoea indica samples from Spain and Merremia dissecta samples from Venezuela identified small non-coding subviral molecules in association with several distinct sweepoviruses. The sequences of 18 clones were obtained and found to be structurally similar to tomato leaf curl virus-satellite (ToLCV-sat, the first DNA satellite identified in association with a begomovirus), with a region with significant sequence identity to the conserved region of betasatellites, an A-rich sequence, a predicted stem–loop structure containing the nonanucleotide TAATATTAC, and a second predicted stem–loop. These sweepovirus-associated satellites join an increasing number of ToLCV-sat-like non-coding satellites identified recently. Although sharing some features with betasatellites, evidence is provided to suggest that the ToLCV-sat-like satellites are distinct from betasatellites and should be considered a separate class of satellites, for which the collective name deltasatellites is proposed.
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Affiliation(s)
- Gloria Lozano
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga - Consejo Superior de Investigaciones Científicas Algarrobo-Costa, Spain
| | - Helena P Trenado
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga - Consejo Superior de Investigaciones Científicas Algarrobo-Costa, Spain
| | - Elvira Fiallo-Olivé
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga - Consejo Superior de Investigaciones Científicas Algarrobo-Costa, Spain
| | | | | | - Rob W Briddon
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering Faisalabad, Pakistan
| | - Jesús Navas-Castillo
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga - Consejo Superior de Investigaciones Científicas Algarrobo-Costa, Spain
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Zhang T, Xu X, Huang C, Qian Y, Li Z, Zhou X. A Novel DNA Motif Contributes to Selective Replication of a Geminivirus-Associated Betasatellite by a Helper Virus-Encoded Replication-Related Protein. J Virol 2016; 90:2077-89. [PMID: 26656709 PMCID: PMC4734014 DOI: 10.1128/jvi.02290-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 12/02/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Rolling-circle replication of single-stranded genomes of plant geminiviruses is initiated by sequence-specific DNA binding of the viral replication-related protein (Rep) to its cognate genome at the replication origin. Monopartite begomovirus-associated betasatellites can be trans replicated by both cognate and some noncognate helper viruses, but the molecular basis of replication promiscuity of betasatellites remains uncharacterized. Earlier studies showed that when tomato yellow leaf curl China virus (TYLCCNV) or tobacco curly shoot virus (TbCSV) is coinoculated with both cognate and noncognate betasatellites, the cognate betasatellite dominates over the noncognate one at the late stages of infection. In this study, we constructed reciprocal chimeric betasatellites between tomato yellow leaf curl China betasatellite and tobacco curly shoot betasatellite and assayed their competitiveness against wild-type betasatellite when coinoculated with TYLCCNV or TbCSV onto plants. We mapped a region immediately upstream of the conserved rolling-circle cruciform structure of betasatellite origin that confers the cognate Rep-mediated replication advantage over the noncognate satellite. DNase I protection and in vitro binding assays further identified a novel sequence element termed Rep-binding motif (RBM), which specifically binds to the cognate Rep protein and to the noncognate Rep, albeit at lower affinity. Furthermore, we showed that RBM-Rep binding affinity is correlated with betasatellite replication efficiency in protoplasts. Our data suggest that although strict specificity of Rep-mediated replication does not exist, betasatellites have adapted to their cognate Reps for efficient replication during coevolution. IMPORTANCE Begomoviruses are numerous circular DNA viruses that cause devastating diseases of crops worldwide. Monopartite begomoviruses are frequently associated with betasatellites which are essential for induction of typical disease symptoms. Coexistence of two distinct betasatellites with one helper virus is rare in nature. Our previous research showed that begomoviruses can trans replicate cognate betasatellites to higher levels than noncognate ones. However, the molecular mechanisms of betasatellites selective replication remain largely unknown. We investigated the interaction between the begomovirus replication-associated protein and betasatellite DNA. We found that the replication-associated protein specifically binds to a motif in betasatellites, with higher affinity for the cognate motif than the noncognate motif. This preference for cognate motif binding determines the selective replication of betasatellites. We also demonstrated that this motif is essential for betasatellite replication. These findings shed new light on the promiscuous yet selective replication of betasatellites by helper geminiviruses.
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Affiliation(s)
- Tong Zhang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Xiongbiao Xu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Changjun Huang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Yajuan Qian
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Zhenghe Li
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
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George B, Alam CM, Kumar RV, Gnanasekaran P, Chakraborty S. Potential linkage between compound microsatellites and recombination in geminiviruses: Evidence from comparative analysis. Virology 2015; 482:41-50. [DOI: 10.1016/j.virol.2015.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 02/16/2015] [Accepted: 03/05/2015] [Indexed: 01/10/2023]
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28
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Ammara UE, Mansoor S, Saeed M, Amin I, Briddon RW, Al-Sadi AM. RNA interference-based resistance in transgenic tomato plants against Tomato yellow leaf curl virus-Oman (TYLCV-OM) and its associated betasatellite. Virol J 2015; 12:38. [PMID: 25890080 PMCID: PMC4359554 DOI: 10.1186/s12985-015-0263-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 02/10/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tomato yellow leaf curl virus (TYLCV), a monopartite begomovirus (family Geminiviridae) is responsible for heavy yield losses for tomato production around the globe. In Oman at least five distinct begomoviruses cause disease in tomato, including TYLCV. Unusually, TYLCV infections in Oman are sometimes associated with a betasatellite (Tomato leaf curl betasatellite [ToLCB]; a symptom modulating satellite). RNA interference (RNAi) can be used to develop resistance against begomoviruses at either the transcriptional or post-transcriptional levels. RESULTS A hairpin RNAi (hpRNAi) construct to express double-stranded RNA homologous to sequences of the intergenic region, coat protein gene, V2 gene and replication-associated gene of Tomato yellow leaf curl virus-Oman (TYLCV-OM) was produced. Initially, transient expression of the hpRNAi construct at the site of virus inoculation was shown to reduce the number of plants developing symptoms when inoculated with either TYLCV-OM or TYLCV-OM with ToLCB-OM to Nicotiana benthamiana or tomato. Solanum lycopersicum L. cv. Pusa Ruby was transformed with the hpRNAi construct and nine confirmed transgenic lines were obtained and challenged with TYLCV-OM and ToLCB-OM by Agrobacterium-mediated inoculation. For all but one line, for which all plants remained symptomless, inoculation with TYLCV-OM led to a proportion (≤25%) of tomato plants developing symptoms of infection. For inoculation with TYLCV-OM and ToLCB-OM all lines showed a proportion of plants (≤45%) symptomatic. However, for all infected transgenic plants the symptoms were milder and virus titre in plants was lower than in infected non-transgenic tomato plants. CONCLUSIONS These results show that RNAi can be used to develop resistance against geminiviruses in tomato. The resistance in this case is not immunity but does reduce the severity of infections and virus titer. Also, the betasatellite may compromise resistance, increasing the proportion of plants which ultimately show symptoms.
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Affiliation(s)
- Um e Ammara
- Department of Crop Sciences, College of Agriculture and Marine Sciences, Sultan Qaboos University, P.O. Box-34, 123, Al-Khod, Oman.
| | - Shahid Mansoor
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P O Box 577, Jhang Road, Faisalabad, Pakistan.
| | - Muhammad Saeed
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P O Box 577, Jhang Road, Faisalabad, Pakistan.
| | - Imran Amin
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P O Box 577, Jhang Road, Faisalabad, Pakistan.
| | - Rob W Briddon
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P O Box 577, Jhang Road, Faisalabad, Pakistan.
| | - Abdullah Mohammed Al-Sadi
- Department of Crop Sciences, College of Agriculture and Marine Sciences, Sultan Qaboos University, P.O. Box-34, 123, Al-Khod, Oman.
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Tahir M, Amin I, Haider MS, Mansoor S, Briddon RW. Ageratum enation virus-a begomovirus of weeds with the potential to infect crops. Viruses 2015; 7:647-65. [PMID: 25674770 PMCID: PMC4353908 DOI: 10.3390/v7020647] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 01/21/2015] [Indexed: 01/21/2023] Open
Abstract
Samples of two Ageratum conyzoides, one Sonchus oleraceus and one turnip (Brassica rapa var. rapa) exhibiting virus-like symptoms were collected from Pakistan and Nepal. Full-length begomovirus clones were obtained from the four plant samples and betasatellite clones from three of these. The begomovirus sequences were shown to be isolates of Ageratum enation virus (AEV) with greater than 89.1% nucleotide sequence identity to the 26 AEV sequences available in the databases. The three betasatellite sequences were shown to be isolates of Ageratum yellow leaf curl betasatellite (AYLCB) with greater than 90% identity to the 18 AYLCB sequences available in the databases. The AEV sequences were shown to fall into two distinct strains, for which the names Nepal (consisting of isolates from Nepal, India, and Pakistan-including the isolates identified here) and India (isolates occurring only in India) strains are proposed. For the clones obtained from two AEV isolates, with their AYLCB, infectivity was shown by Agrobacterium-mediated inoculation to Nicotiana benthamiana, N. tabacum, Solanum lycopersicon and A. conyzoides. N. benthamiana plants infected with AEV alone or betasatellite alone showed no symptoms. N. benthamiana plants infected with AEV with its associated betasatellite showed leaf curl symptoms. The findings show that AEV is predominantly a virus of weeds that has the capacity to infect crops. AYLCB appears to be the common partner betasatellite of AEV and is associated with diseases with a range of very different symptoms in the same plant species. The inability to satisfy Koch's postulates with the cloned components of isolate SOL in A. conyzoides suggests that the etiology may be more complex than a single virus with a single betasatellite.
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Affiliation(s)
- Muhammad Tahir
- Plant Biotechnology Department, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Sector H-12, Islamabad 44000, Pakistan.
| | - Imran Amin
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad 38000, Pakistan.
| | - Muhammad Saleem Haider
- School of Biological Sciences, University of the Punjab, New Campus, Lahore 54590, Pakistan.
| | - Shahid Mansoor
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad 38000, Pakistan.
| | - Rob W Briddon
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad 38000, Pakistan.
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30
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Insights into the functional characteristics of geminivirus rolling-circle replication initiator protein and its interaction with host factors affecting viral DNA replication. Arch Virol 2014; 160:375-87. [PMID: 25449306 DOI: 10.1007/s00705-014-2297-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 11/24/2014] [Indexed: 10/24/2022]
Abstract
Geminiviruses are DNA viruses that infect several economically important crops, resulting in a reduction in their overall yield. These plant viruses have circular, single-stranded DNA genomes that replicate mainly by a rolling-circle mechanism. Geminivirus infection results in crosstalk between viral and cellular factors to complete the viral life cycle or counteract the infection as part of defense mechanisms of host plants. The geminiviral replication initiator protein Rep is the only essential viral factor required for replication. It is multifunctional and is known to interact with a number of host factors to modulate the cellular environment or to function as a part of the replication machinery. This review provides a holistic view of the research related to the viral Rep protein and various host factors involved in geminiviral DNA replication. Studies on the promiscuous nature of geminiviral satellite DNAs are also reviewed.
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Sohrab SS, Azhar EI, Kamal MA, Bhattacharya PS, Rana D. Genetic variability of Cotton leaf curl betasatellite in Northern India. Saudi J Biol Sci 2014; 21:626-31. [PMID: 25473373 DOI: 10.1016/j.sjbs.2014.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 11/02/2014] [Accepted: 11/03/2014] [Indexed: 11/20/2022] Open
Abstract
Cotton is an important crop and its production is affected by various disease pathogens. Monopartite begomovirus associated betasatellites cause Cotton leaf curl disease (CLCuD) in Northern India. In order to access the occurrence and genetic variability of Cotton leaf curl betasatellites, an extensive field survey was conducted in states of Rajasthan, Punjab and Haryana. We selected the betasatellite sequence for analysis as they are reported as important for disease severity and sequence variability. Based on the field observations, the disease incidence ranged from 30% to 80% during the survey. Full genome and DNA β were amplified from various samples while no amplicon was obtained in some samples. The nucleotide sequence homology ranged from 90.0% to 98.7% with Cotton leaf curl virus (CLCuV), 55.2-55.5% with Bhendi yellow vein mosaic virus, 55.8% with Okra leaf curl virus and 51.70% with Tomato leaf curl virus isolates. The lowest similarity (47.8%) was found in CLCuV-Sudan isolate. Phylogenetic analysis showed that analyzed isolates formed a close cluster with various CLCuV isolates reported earlier. The analysis results show sequence variation in Cotton leaf curl betasatellite which could be the result of recombination. The results obtained by genome amplification and sequence variability indicate that some new variants are circulating and causing leaf curl disease in Rajasthan, Punjab and Haryana.
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Affiliation(s)
- Sayed Sartaj Sohrab
- Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, Post Box No. 80216, Jeddah 21589, Saudi Arabia
| | - Esam I Azhar
- Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, Post Box No. 80216, Jeddah 21589, Saudi Arabia
| | - Mohammad A Kamal
- King Fahd Medical Research Center, King Abdulaziz University, Post Box No. 80216, Jeddah 21589, Saudi Arabia
| | - P S Bhattacharya
- Division of Biotechnology, JK-AgriGenetics Ltd., Hyderabad, A.P., India
| | - D Rana
- Division of Biotechnology, JK-AgriGenetics Ltd., Hyderabad, A.P., India
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Kumar J, Kumar J, Singh SP, Tuli R. βC1 is a pathogenicity determinant: not only for begomoviruses but also for a mastrevirus. Arch Virol 2014; 159:3071-6. [PMID: 25000899 DOI: 10.1007/s00705-014-2149-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 06/08/2014] [Indexed: 11/24/2022]
Abstract
βC1 proteins, encoded by betasatellites, are known to be pathogenicity determinants, and they are responsible for symptom expression in many devastating diseases caused by begomoviruses. We report the involvement of βC1 in pathogenicity determination of a mastrevirus. Analysis of field samples of wheat plants containing wheat dwarf India virus (WDIV) revealed the presence of a full-length and several defective betasatellite molecules. The detected betasatellite was identified as ageratum yellow leaf curl betasatellite (AYLCB). No begomovirus was detected in any of the samples. The full-length AYLCB contained an intact βC1 gene, whereas the defective molecules contained complete or partial deletions of βC1. Agroinoculation of wheat with the full-length AYLCB and WDIV or of tobacco with ageratum enation virus enhanced the pathogenicity and accumulation of the respective viruses, whereas the defective molecules could not. This study indicates that βC1 is a pathogenicity determinant for WDIV and can interact functionally not only with begomoviruses but also with a mastrevirus.
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Affiliation(s)
- Jitendra Kumar
- Department of Biotechnology, National Agri-Food Biotechnology Institute, Mohali, 160071, Punjab, India
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Khatri S, Nahid N, Fauquet CM, Mubin M, Nawaz-ul-Rehman MS. A betasatellite-dependent begomovirus infects ornamental rose: characterization of begomovirus infecting rose in Pakistan. Virus Genes 2014; 49:124-31. [PMID: 24781196 DOI: 10.1007/s11262-014-1076-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 04/10/2014] [Indexed: 10/25/2022]
Abstract
The Begomovirus genus of the family Geminiviridae comprises the largest group of geminiviruses. The list of begomoviruses is continuously increasing as a result of improvement in the methods for identification. Ornamental rose plants (Rosa chinensis) with highly stunted growth and leaf curling were found in Faisalabad, Pakistan. Plants were analyzed for begomovirus infection, through rolling circle amplification and PCR methods. Based on complete genome sequence homologies with other begomoviruses, a new begomovirus species infecting the rose plants was discovered. In this paper, we propose a new species name, Rose leaf curl virus (RoLCuV), for the virus. RoLCuV showed close identity (83 %) with Tomato leaf curl Pakistan virus, while associated betasatellite showed 96 % identity with Digera arvensis yellow vein betasatellite (DiAYVB), justifying a new isolate for the betasatellite. Recombination analysis of newly identified begomovirus revealed it as a recombinant of tomato leaf curl Pakistan virus from its coat protein region. The infectious molecules for virus/satellite were prepared and inoculated through Agrobacterium tumefaciens to N. benthamiana plants. RoLCuV alone was unable to induce any level of symptoms on N. benthamiana plants, but co-inoculation with cognate betasatellite produced infection symptoms. Further investigation to understand the trans-replication ability of betasatellites revealed their flexibility to interact with Rose leaf curl virus.
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Affiliation(s)
- Sandeep Khatri
- Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA, 15261, USA
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Regional changes in the sequence of cotton leaf curl multan betasatellite. Viruses 2014; 6:2186-203. [PMID: 24859342 PMCID: PMC4036549 DOI: 10.3390/v6052186] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 05/02/2014] [Accepted: 05/12/2014] [Indexed: 11/23/2022] Open
Abstract
Cotton leaf curl disease (CLCuD) in Pakistan and northwestern India is caused by monopartite begomoviruses in association with an essential, disease-specific satellite, Cotton leaf curl Multan betasatellite (CLCuMB). Following a recent upsurge in CLCuD problems in Sindh province (southern Pakistan), sequences of clones of CLCuMB were obtained from Sindh and Punjab province (central Pakistan), where CLCuD has been a problem since the mid-1980s. The sequences were compared to all sequences of CLCuMB available in the databases. Analysis of the sequences shows extensive sequence variation in CLCuMB, most likely resulting from recombination. The range of sequence variants differ between Sindh, the Punjab and northwestern India. The possible significance of the findings with respect to movement of the CLCuD between the three regions is discussed. Additionally, the lack of sequence variation within the only coding sequence of CLCuMB suggests that the betasatellite is not involved in resistance breaking which became a problem after 2001 in the Punjab and subsequently also in northwestern India.
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Association of satellites with a mastrevirus in natural infection: complexity of Wheat dwarf India virus disease. J Virol 2014; 88:7093-104. [PMID: 24719407 DOI: 10.1128/jvi.02911-13] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED In contrast to begomoviruses, mastreviruses have not previously been shown to interact with satellites. This study reports the first identification of the association of satellites with a mastrevirus in field-grown plants. Two alphasatellite species were detected in different field samples of wheat infected with Wheat Dwarf India Virus (WDIV), a Cotton leaf curl Multan alphasatellite (CLCuMA) and a Guar leaf curl alphasatellite (GLCuA). In addition to the alphasatellites, a betasatellite, Ageratum yellow leaf curl betasatellite (AYLCB), was also identified in the wheat samples. No begomovirus was detected in the wheat samples, thus establishing association of the above-named satellites with WDIV. Agrobacterium-mediated inoculation of WDIV in wheat, in the presence of either of the alphasatellites or the betasatellite, resulted in infections inducing more severe symptoms. WDIV efficiently maintained each of the alphasatellites and the betasatellite in wheat. The satellites enhanced the level of WDIV DNA in wheat. Inoculation of the satellites isolated from wheat with various begomoviruses into Nicotiana tabacum demonstrated that these remain capable of interacting with the viruses with which they were first identified. Virus-specific small RNAs accumulated in wheat upon infection with WDIV but were lower in abundance in plants coinfected with the satellites, suggesting that both the alphasatellites and the betasatellite suppress RNA silencing. These results suggest that the selective advantage for the maintenance of the alphasatellites and the betasatellite by WDIV in the field is in overcoming RNA silencing-mediated host defense. IMPORTANCE Wheat is the most widely cultivated cereal crop in the world. A number of viruses are important pathogens of wheat, including the viruses of the genus Mastrevirus, family Geminiviridae. This study reports the association of subgenomic components, called satellites (alpha- and betasatellites), with a mastrevirus, Wheat Dwarf India Virus (WDIV), isolated from two distant locations in India. This study reports the first identification of the satellites in a monocot plant. The satellites enhanced accumulation of WDIV and severity of disease symptoms. The satellites lowered the concentration of virus-specific small RNAs in wheat plants, indicating their silencing suppressor activity. The involvement of the satellites in symptom severity of the mastrevirus can have implications in the form of economic impact of the virus on crop yield. Understanding the role of the satellites in disease severity is important for developing disease management strategies.
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Ranjan P, Singh AK, Kumar RV, Basu S, Chakraborty S. Host-specific adaptation of diverse betasatellites associated with distinct Indian tomato-infecting begomoviruses. Virus Genes 2014; 48:334-42. [DOI: 10.1007/s11262-013-1031-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 12/21/2013] [Indexed: 10/25/2022]
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Fiallo-Olivé E, Hamed A, Navas-Castillo J, Moriones E. Cotton leaf curl Gezira alphasatellite associated with tomato leaf curl Sudan virus approaches the expected upper size limit in the evolution of alphasatellites. Virus Res 2013; 178:506-10. [DOI: 10.1016/j.virusres.2013.10.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/02/2013] [Accepted: 10/07/2013] [Indexed: 11/29/2022]
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Jiao X, Gong H, Liu X, Xie Y, Zhou X. Etiology of Ageratum Yellow Vein Diseases in South China. PLANT DISEASE 2013; 97:1497-1503. [PMID: 30708480 DOI: 10.1094/pdis-01-13-0074-re] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Ageratum conyzoides is a common weed in agricultural regions in Asia. A. conyzoides plants exhibiting yellow vein symptoms were collected from Yunnan and Guangxi provinces of China. Polymerase chain reaction detection and sequence analysis showed that samples collected from Yunnan were mainly infected by Tobacco curly shoot virus (TbCSV) associated with Ageratum yellow vein China betasatellite (AYVCNB), while samples from Guangxi were mostly infected by Papaya leaf curl China virus (PaLCuCNV) and AYVCNB, or by Ageratum yellow vein China virus (AYVCNV) and AYVCNB, with a few exhibiting dual infections by PaLCuCNV, AYVCNV, and AYVCNB. Agrobacterium-mediated inoculation of infectious clones showed that both TbCSV and AYVCNB or PaLCuCNV and AYVCNB produced typical yellow vein symptoms in A. conyzoides. Consequently, Ageratum yellow vein diseases in Yunnan and Guangxi provinces were caused by TbCSV/AYVCNB, PaLCuCNV/AYVCNB, or AYVCNV/ AYVCNB. The implications of these results in relation to the prevalence of begomoviruses in cultivated plants are discussed.
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Affiliation(s)
- Xiaoyang Jiao
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Huanran Gong
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xuejian Liu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yan Xie
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
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Khan AJ, Akhtar S, Al-Zaidi AM, Singh AK, Briddon RW. Genetic diversity and distribution of a distinct strain of Chili leaf curl virus and associated betasatellite infecting tomato and pepper in Oman. Virus Res 2013; 177:87-97. [PMID: 23911631 DOI: 10.1016/j.virusres.2013.07.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 07/12/2013] [Accepted: 07/20/2013] [Indexed: 11/28/2022]
Abstract
Tomato and pepper are widely grown in Oman for local consumption. A countrywide survey was conducted during 2010-2011 to collect samples and assess the diversity of begomoviruses associated with leaf curl disease of tomato and pepper. A virus previously only identified on the Indian subcontinent, chili leaf curl virus (ChLCV), was found associated with tomato and pepper diseases in all vegetable grown areas of Oman. Some of the infected plant samples were also found to contain a betasatellite. A total of 19 potentially full-length begomovirus and eight betasatellite clones were sequenced. The begomovirus clones showed >96% nucleotide sequence identity, showing them to represent a single species. Comparisons to sequences available in the databases showed the highest levels of nucleotide sequence identity (88.0-91.1%) to isolates of the "Pakistan" strain of ChLCV (ChLCV-PK), indicating the virus from Oman to be a distinct strain, for which the name Oman strain (ChLCV-OM) is proposed. An analysis for recombination showed ChLCV-OM likely to have originated by recombination between ChLCV-PK (the major parent), pepper leaf curl Lahore virus and a third strain of ChLCV. The betasatellite sequences obtained were shown to have high levels of identity to isolates of tomato leaf curl betasatellite (ToLCB) previous shown to be present in Oman. For the disease in tomato Koch's postulates were satisfied by Agrobacterium-mediated inoculation of virus and betasatellites clones. This showed the symptoms induced by the virus in the presence of the betasatellite to be enhanced, although viral DNA levels were not affected. ChLCV-OM is the fourth begomovirus identified in tomato in Oman and the first in Capsicum. The significance of these findings is discussed.
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Affiliation(s)
- Akhtar J Khan
- Department of Crop Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, P.O. Box-34, Al-Khod 123, Oman.
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Ranjan P, Kumar RV, Chakraborty S. Differential pathogenicity among Tomato leaf curl Gujarat virus isolates from India. Virus Genes 2013; 47:524-31. [PMID: 24026875 DOI: 10.1007/s11262-013-0977-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 08/26/2013] [Indexed: 01/27/2023]
Abstract
Tomato leaf curl Gujarat virus (ToLCGV) has been identified as one of the most destructive pathogens causing tomato leaf curl disease (ToLCD) in India. In the tomato growing regions of Dhanbad and Ramgarh, plants bearing severe symptoms of ToLCD such as leaf curling, leaf crinkling, yellowing and leaf rolling was observed in the farmer fields. The association of begomovirus in these samples was confirmed by PCR and the causal viruses were identified as the isolates of ToLCGV. However, association of cognate DNA B component could not be ascertained from these samples. Indeed, like other Old World begomoviruses, the present ToLCGV isolates were found to be associated with a particular betasatellite, Tomato yellow leaf curl Thailand betasatellite (TYLCTHB). Although DNA A of both ToLCGV isolates could alone infect tomato inducing systemic symptoms, the difference in virulence was observed. Co-inoculation of TYLCTHB reduced the incubation period without influencing the accumulation of helper virus DNA and hence, differential pathogenesis among ToLCGV isolates was governed by the helper component rather than betasatellite. ToLCGV infection with DNA B increases the accumulation of DNA A component of Dhanbad isolate but not of Ramgarh isolate. Results indicated that the begomovirus identified from Ramgarh sample was a mild strain of ToLCGV.
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Affiliation(s)
- Punam Ranjan
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
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41
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Huang C, Xie Y, Zhao L, Ren H, Li Z. A naturally occurring defective DNA satellite associated with a monopartite begomovirus: evidence for recombination between alphasatellite and betasatellite. Viruses 2013; 5:2116-28. [PMID: 24018984 PMCID: PMC3798893 DOI: 10.3390/v5092116] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 09/01/2013] [Accepted: 09/02/2013] [Indexed: 01/01/2023] Open
Abstract
Monopartite begomoviruses and their associated satellites form unique disease complexes that have emerged as a serious threat to agriculture worldwide. It is well known that frequent recombination contributes to the diversification and evolution of geminiviruses. In this study, we identified a novel defective satellite molecule (RecSat) in association with Tobacco leaf curl Yunnan virus (TbLCYNV) in a naturally infected tobacco plant. Sequence analysis showed that Recsat comprises 754 nucleotides in size and is a chimera involving alphasatellite and betasatellite sequences, containing both betasatellite-conserved region and alphasatellite stem-loop structure. Recombination analysis revealed that RecSat has arisen from three independent recombination events likely involving Tomato yellow leaf curl China betasatellite, Ageratum yellow vein China betasatellite and Tobacco curly shoot alphasatellite. Co-inoculation of RecSat with TbLCYNV induced symptoms indistinguishable from those induced by TbLCYNV alone in Nicotiana benthamiana. Southern blot hybridization showed that RecSat could be trans-replicated stably in N. benthamiana plants by TbLCYNV, and impaired the accumulation of helper virus and co-inoculated alphasatellite. Our results provide the first evidence for recombination between two distinct types of satellites among geminivirus complex and highlight recombination as a driving force for geminivirus evolution.
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Affiliation(s)
| | | | | | | | - Zhenghe Li
- Key Laboratory of Molecular Biology of Crop Pathogens and Insects of MOA, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China; E-Mails: (C.H.); (Y.X.); (L.Z.); (H.R.)
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Abstract
Geminiviruses are a family of plant viruses that cause economically important plant diseases worldwide. These viruses have circular single-stranded DNA genomes and four to eight genes that are expressed from both strands of the double-stranded DNA replicative intermediate. The transcription of these genes occurs under the control of two bidirectional promoters and one monodirectional promoter. The viral proteins function to facilitate virus replication, virus movement, the assembly of virus-specific nucleoprotein particles, vector transmission and to counteract plant host defence responses. Recent research findings have provided new insights into the structure and function of these proteins and have identified numerous host interacting partners. Most of the viral proteins have been shown to be multifunctional, participating in multiple events during the infection cycle and have, indeed, evolved coordinated interactions with host proteins to ensure a successful infection. Here, an up-to-date review of viral protein structure and function is presented, and some areas requiring further research are identified.
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Affiliation(s)
- Vincent N Fondong
- Department of Biological Sciences, Delaware State University, 1200 North DuPont Highway, Dover, DE 19901, USA.
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Jyothsna P, Haq QMI, Singh P, Sumiya KV, Praveen S, Rawat R, Briddon RW, Malathi VG. Infection of tomato leaf curl New Delhi virus (ToLCNDV), a bipartite begomovirus with betasatellites, results in enhanced level of helper virus components and antagonistic interaction between DNA B and betasatellites. Appl Microbiol Biotechnol 2013; 97:5457-71. [PMID: 23306645 DOI: 10.1007/s00253-012-4685-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 12/20/2012] [Accepted: 12/22/2012] [Indexed: 11/24/2022]
Abstract
Tomato leaf curl New Delhi virus (ToLCNDV) (Geminiviridae) is an important pathogen that severely affects tomato production. An extensive survey was carried out during 2003-2010 to study the diversity of begomoviruses found in tomato, potato, and cucurbits that showed symptoms of leaf puckering, distortion, curling, vein clearing, and yellow mosaic in various fields in different regions of India. Ten begomovirus isolates were cloned from infected samples and identified as belonging to the species ToLCNDV. A total of 44 % of the samples showed association of betasatellites, with CLCuMuB and LuLDB being the most frequent. The ToLCNDV cloned component DNA A and DNA B were agroinoculated on Nicotiana benthamiana and tomato (Solanum lycopersicum) plants with or without betasatellites, CLCuMuB or LuLDB. The viral genome levels were then monitored by real-time polymerase chain reaction at different time points of disease development. Plants co-inoculated with betasatellites showed enhanced symptom severity in both N. benthamiana and tomato, as well as increases in helper viral DNA A and DNA B levels. The DNA B and betasatellites acted antagonistically to each other, so that the level of DNA B was 16-fold greater in the presence of betasatellites, while accumulation of betasatellites, CLCuMuB and LuLDB, were reduced by 60 % in the presence of DNA B. DNA B-mediated symptoms predominated in CLCuMuB-inoculated plants, whereas betasatellite-mediated leaf abnormalities were prominent in LuLDB-co-inoculated plants. Inoculation with the cloned components will be a good biotechnological tool in resistance breeding program.
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Affiliation(s)
- P Jyothsna
- Advanced Centre for Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi, India 110012
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Sattar MN, Kvarnheden A, Saeed M, Briddon RW. Cotton leaf curl disease - an emerging threat to cotton production worldwide. J Gen Virol 2013; 94:695-710. [PMID: 23324471 DOI: 10.1099/vir.0.049627-0] [Citation(s) in RCA: 143] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cotton leaf curl disease (CLCuD) is a serious disease of cotton which has characteristic symptoms, the most unusual of which is the formation of leaf-like enations on the undersides of leaves. The disease is caused by whitefly-transmitted geminiviruses (family Geminiviridae, genus Begomovirus) in association with specific, symptom-modulating satellites (betasatellites) and an evolutionarily distinct group of satellite-like molecules known as alphasatellites. CLCuD occurs across Africa as well as in Pakistan and north-western India. Over the past 25 years, Pakistan and India have experienced two epidemics of the disease, the most recent of which involved a virus and satellite that are resistance breaking. Loss of this conventional host-plant resistance, which saved the cotton growers from ruin in the late 1990s, leaves farmers with only relatively poor host plant tolerance to counter the extensive losses the disease causes. There has always been the fear that CLCuD could spread from the relatively limited geographical range it encompasses at present to other cotton-growing areas of the world where, although the disease is not present, the environmental conditions are suitable for its establishment and the whitefly vector occurs. Unfortunately recent events have shown this fear to be well founded, with CLCuD making its first appearance in China. Here, we outline recent advances made in understanding the molecular biology of the components of the disease complex, their interactions with host plants, as well as efforts being made to control CLCuD.
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Affiliation(s)
- M Naeem Sattar
- Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Box 7080, SE-750 07 Uppsala, Sweden
| | - Anders Kvarnheden
- Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Box 7080, SE-750 07 Uppsala, Sweden
| | - Muhammad Saeed
- National Institute for Biotechnology and Genetic Engineering, PO Box 577, Jhang Road, Faisalabad, Pakistan
| | - Rob W Briddon
- National Institute for Biotechnology and Genetic Engineering, PO Box 577, Jhang Road, Faisalabad, Pakistan
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Abstract
Begomoviruses are numerous and geographically widespread viruses that cause devastating diseases in many crops. Monopartite begomoviruses are frequently associated with betasatellites or alphasatellites. Both betasatellite and alphasatellite DNA genomes are approximately half the size of begomovirus DNA genomes. Betasatellites are essential for induction of typical disease symptoms. The βC1 genes encoded by the betasatellites have important roles in symptom induction, in suppression of transcriptional and posttranscriptional gene silencing, and they can affect jasmonic acid responsive genes. Host plants of begomoviruses have evolved diverse innate defense mechanisms against the βC1 protein to counter these challenges. Alphasatellites have been identified mainly in monopartite begomoviruses that associate with betasatellites and have no known contributions to pathogenesis of begomovirus-betasatellite disease complexes. Applications of current molecular tools are facilitating viral diagnosis and the discovery of novel species of geminiviruses and satellite DNAs and are also advancing our understanding of the global diversity and evolution of satellite DNAs.
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Affiliation(s)
- Xueping Zhou
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
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46
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Jyothsna P, Rawat R, Malathi VG. Predominance of tomato leaf curl Gujarat virus as a monopartite begomovirus: association with tomato yellow leaf curl Thailand betasatellite. Arch Virol 2013; 158:217-24. [PMID: 22983111 DOI: 10.1007/s00705-012-1468-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 07/27/2012] [Indexed: 11/28/2022]
Abstract
Tomato leaf curl is a serious malady in the state of Maharashtra, India, causing nearly 100 % yield loss. An extensive survey was done in the affected fields of tomato in the year 2008, and members of three species of begomoviruses were identified as causing the disease. More than 60 % of the samples from diseased plants were infected with tomato leaf curl Gujarat virus (ToLCGuV). Isolates collected from these fields differed from the Varanasi isolate of ToLCGuV in not having a DNA B component. Instead, they were like typical Old World monopartite begomoviruses in that they were associated with only one betasatellite, tomato yellow leaf curl Thailand betasatellite (TYLCTHB). ToLCGuV alone is readily infectious, expressing systemic symptoms in Nicotiana benthamiana and tomato. Co-inoculation of ToLCGuV with TYLCTHB, increased symptom severity and reduced the incubation time required for symptom expression. ToLCGuV successfully interacted with heterologous DNA B component of ToLCNDV [IN:Pun:JID:08], and co-inoculation of these two resulted in yellow mottling symptoms that were typical of DNA B.
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Affiliation(s)
- P Jyothsna
- Advanced Centre for Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi 110012, India
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47
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Nawaz-ul-Rehman MS, Briddon RW, Fauquet CM. A melting pot of Old World begomoviruses and their satellites infecting a collection of Gossypium species in Pakistan. PLoS One 2012; 7:e40050. [PMID: 22899988 PMCID: PMC3416816 DOI: 10.1371/journal.pone.0040050] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 05/31/2012] [Indexed: 11/19/2022] Open
Abstract
CLCuD in southern Asia is caused by a complex of multiple begomoviruses (whitefly transmitted, single-stranded [ss]DNA viruses) in association with a specific ssDNA satellite; Cotton leaf curl Multan betasatellite (CLCuMuB). A further single ssDNA molecule, for which the collective name alphasatellites has been proposed, is also frequently associated with begomovirus-betasatellite complexes. Multan is in the center of the cotton growing area of Pakistan and has seen some of the worst problems caused by CLCuD. An exhaustive analysis of the diversity of begomoviruses and their satellites occurring in 15 Gossypium species (including G. hirsutum, the mainstay of Pakistan's cotton production) that are maintained in an orchard in the vicinity of Multan has been conducted using φ29 DNA polymerase-mediated rolling-circle amplification, cloning and sequence analysis. The non-cultivated Gossypium species, including non-symptomatic plants, were found to harbor a much greater diversity of begomoviruses and satellites than found in the cultivated G. hirsutum. Furthermore an African cassava mosaic virus (a virus previously only identified in Africa) DNA-A component and a Jatropha curcas mosaic virus (a virus occurring only in southern India) DNA-B component were identified. Consistent with earlier studies of cotton in southern Asia, only a single species of betasatellite, CLCuMuB, was identified. The diversity of alphasatellites was much greater, with many previously unknown species, in the non-cultivated cotton species than in G. hirsutum. Inoculation of newly identified components showed them to be competent for symptomatic infection of Nicotiana benthamiana plants. The significance of the findings with respect to our understanding of the role of host selection in virus diversity in crops and the geographical spread of viruses by human activity are discussed.
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Affiliation(s)
| | - Rob W. Briddon
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad, Pakistan
| | - Claude M. Fauquet
- Danforth Plant Science Center, St. Louis, Missouri, United States of America
- * E-mail:
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Iqbal Z, Sattar MN, Kvarnheden A, Mansoor S, Briddon RW. Effects of the mutation of selected genes of cotton leaf curl Kokhran virus on infectivity, symptoms and the maintenance of cotton leaf curl Multan betasatellite. Virus Res 2012; 169:107-16. [PMID: 22871297 DOI: 10.1016/j.virusres.2012.07.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 07/13/2012] [Accepted: 07/17/2012] [Indexed: 10/28/2022]
Abstract
Cotton leaf curl Kokhran virus (CLCuKoV) is a cotton-infecting monopartite begomovirus (family Geminiviridae). The effects of mutation of the coat protein (CP), V2, C2 and C4 genes of CLCuKoV on infectivity and symptoms in Nicotiana benthamiana were investigated. Each mutation introduced a premature stop codon which would lead to premature termination of translation of the gene. Mutation of the CP gene abolished infectivity. However, transient expression of the CLCuKoV CP gene under the control of the Cauliflower mosaic virus 35S promoter (35S-Ko(CP)), at the point of inoculation, led to a small number of plants in which viral DNA could be detected by PCR in tissues distal to the inoculation site. Mutations of the V2, C2 and C4 genes reduced infectivity. The V2 and C2 mutants did not induce symptoms, whereas the C4 mutation was associated with attenuated symptoms. Infections of plants with the C4 mutant were associated with viral DNA levels equivalent to the wild-type virus, whereas viral DNA levels for the V2 mutant were low, detectable by Southern blot hybridisation, and for the C2 mutant were detectable only by PCR. Significantly, transient expression of the CLCuKoV C2 gene at the point of inoculation, raised virus DNA levels in tissues distal to the inoculation site such that they could be detected by Southern hybridisation, although they remained at well below the levels seen for the wild-type virus, but reduced the infectivity of the virus. These findings are consistent with earlier mutation studies of monopartite begomoviruses and our present knowledge concerning the functions of the four genes suggesting that the CP is essential for long distance spread of the virus in plants, the C4 is involved in modulating symptoms, the C2 interferes with host defence and the V2 is involved in virus movement. The results also suggest that the V2, C2 and C4 may be pathogenicity determinants. Additionally the effects of the mutations of CLCuKoV genes on infections of the virus in the presence of its cognate betasatellite, Cotton leaf curl Multan betasatellite (CLCuMuB), were investigated. Mutation of the C4 gene had no effect on maintenance of the betasatellite, although the betasatellite enhanced symptoms. Inoculation of the C2 mutant with CLCuMuB raised the infectivity of the virus to near wild-type levels, although the numbers of plants in which the betasatellite was maintained was reduced, in comparison to wild-type virus infections with CLCuMuB, and viral DNA could not be detected by Southern hybridisation. Transient expression of the C2 gene at the point of inoculation raised virus DNA levels in tissues distal to the inoculation site but also reduced the infectivity of the virus and the numbers of plants in which the betasatellite was maintained. CLCuMuB restored the infectivity of the V2 mutant to wild-type levels but only in a small number of plants was the satellite maintained and infections were non-symptomatic. Although inoculation of the CP mutant with CLCuMuB did not restore infectivity, co-inoculation with 35S-Ko(CP) increased the number of plants in which the virus could be detected, in comparison to plants inoculated with the mutant and 35S-Ko(CP), and also resulted in two plants (out of 15 inoculated) in which the betasatellite could be detected by PCR. This indicates that the V2, C2 and almost certainly the CP are important for the maintenance of betasatellites by monopartite begomoviruses. The significance of these findings is discussed.
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Affiliation(s)
- Zafar Iqbal
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad, Pakistan.
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Ueda S, Onuki M, Yamashita M, Yamato Y. Pathogenicity and insect transmission of a begomovirus complex between tomato yellow leaf curl virus and Ageratum yellow vein betasatellite. Virus Genes 2012; 44:338-44. [PMID: 22105924 DOI: 10.1007/s11262-011-0691-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 11/05/2011] [Indexed: 10/15/2022]
Abstract
Tomato yellow leaf curl virus (TYLCV) and Ageratum yellow vein betasatellite (AYVB) are members of the genus Begomovirus (family Geminiviridae). TYLCV and AYVB have been found in Japan over the last 15 years, and are associated with tomato leaf curl and the tomato yellow leaf curl diseases (TYLCD). AYVB is also associated with some monopartite begomoviruses. We have cloned both TYLCV and AYVB and demonstrated that TYLCV can trans-replicate with AYVB in Nicotiana benthamiana and tomato plants. A mixed infection of TYLCV and AYVB induced more severe symptoms of upward leaf curl, stunting, vein thickening, and swelling compared with TYLCV infection alone. The symptoms induced by infection of AYVB included a rise in abnormal cell proliferation, and pigmentation around leaf vein tissues. This is the first study to show that a complex of TYLCV and AYVB can be transmitted by vector insects among tomato plants. These results indicate that TYLCV possesses the potential to induce severe TYLCD by associating with AYVB.
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Affiliation(s)
- Shigenori Ueda
- Kurume Research Station, National Agricultural Research Center for Kyushu Okinawa Region, 1823 Mii, Kurume, Fukuoka 839-8503, Japan.
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A novel class of DNA satellites associated with New World begomoviruses. Virology 2012; 426:1-6. [DOI: 10.1016/j.virol.2012.01.024] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 01/11/2012] [Accepted: 01/18/2012] [Indexed: 11/24/2022]
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