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Liu Q. Dynamical analysis of a stochastic maize streak virus epidemic model with logarithmic Ornstein-Uhlenbeck process. J Math Biol 2024; 89:30. [PMID: 39017723 DOI: 10.1007/s00285-024-02127-3] [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] [Received: 12/23/2023] [Revised: 07/01/2024] [Accepted: 07/07/2024] [Indexed: 07/18/2024]
Abstract
To describe the transmission dynamics of maize streak virus infection, in the paper, we first formulate a stochastic maize streak virus infection model, in which the stochastic fluctuations are depicted by a logarithmic Ornstein-Uhlenbeck process. This approach is reasonable to simulate the random impacts of main parameters both from the biological significance and the mathematical perspective. Then we investigate the detailed dynamics of the stochastic system, including the existence and uniqueness of the global solution, the existence of a stationary distribution, the exponential extinction of the infected maize and infected leafhopper vector. Especially, by solving the five-dimensional algebraic equations corresponding to the stochastic system, we obtain the specific expression of the probability density function near the quasi-endemic equilibrium of the stochastic system, which provides valuable insights into the stationary distribution. Finally, the model is discretized using the Milstein higher-order numerical method to illustrate our theoretical results numerically. Our findings provide a groundwork for better methods of preventing the spread of this type of virus.
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Affiliation(s)
- Qun Liu
- School of Mathematics and Statistics, Key Laboratory of Applied Statistics of MOE, Key Laboratory of Big Data Analysis of Jilin Province, Northeast Normal University, Changchun, 130024, Jilin Province, People's Republic of China.
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2
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Pfrieme AK, Will T, Pillen K, Stahl A. The Past, Present, and Future of Wheat Dwarf Virus Management-A Review. PLANTS (BASEL, SWITZERLAND) 2023; 12:3633. [PMID: 37896096 PMCID: PMC10609771 DOI: 10.3390/plants12203633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 09/29/2023] [Accepted: 10/04/2023] [Indexed: 10/29/2023]
Abstract
Wheat dwarf disease (WDD) is an important disease of monocotyledonous species, including economically important cereals. The causative pathogen, wheat dwarf virus (WDV), is persistently transmitted mainly by the leafhopper Psammotettix alienus and can lead to high yield losses. Due to climate change, the periods of vector activity increased, and the vectors have spread to new habitats, leading to an increased importance of WDV in large parts of Europe. In the light of integrated pest management, cultivation practices and the use of resistant/tolerant host plants are currently the only effective methods to control WDV. However, knowledge of the pathosystem and epidemiology of WDD is limited, and the few known sources of genetic tolerance indicate that further research is needed. Considering the economic importance of WDD and its likely increasing relevance in the coming decades, this study provides a comprehensive compilation of knowledge on the most important aspects with information on the causal virus, its vector, symptoms, host range, and control strategies. In addition, the current status of genetic and breeding efforts to control and manage this disease in wheat will be discussed, as this is crucial to effectively manage the disease under changing environmental conditions and minimize impending yield losses.
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Affiliation(s)
- Anne-Kathrin Pfrieme
- Institute for Resistance Research and Stress Tolerance, Julius Kühn Institute (JKI)—Federal Research Centre for Cultivated Plants, 06484 Quedlinburg, Germany; (T.W.); (A.S.)
| | - Torsten Will
- Institute for Resistance Research and Stress Tolerance, Julius Kühn Institute (JKI)—Federal Research Centre for Cultivated Plants, 06484 Quedlinburg, Germany; (T.W.); (A.S.)
| | - Klaus Pillen
- Institute of Agricultural and Nutritional Science, Plant Breeding, Martin-Luther-University Halle-Wittenberg, 06108 Halle (Saale), Germany;
| | - Andreas Stahl
- Institute for Resistance Research and Stress Tolerance, Julius Kühn Institute (JKI)—Federal Research Centre for Cultivated Plants, 06484 Quedlinburg, Germany; (T.W.); (A.S.)
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3
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Neuenschwander P, Borgemeister C, De Groote H, Sæthre MG, Tamò M. Perspective article: Food security in tropical Africa through climate-smart plant health management. Heliyon 2023; 9:e15116. [PMID: 37151684 PMCID: PMC10161365 DOI: 10.1016/j.heliyon.2023.e15116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 03/24/2023] [Accepted: 03/27/2023] [Indexed: 05/09/2023] Open
Abstract
Each year, Africa loses half of its harvest to pests (insects, pathogens, nematodes, weeds). To offset these losses and improve food security, pest management needs to be revamped urgently. Based on a synthesis of all 58 pest management projects conducted by IITA in its 55-year history, we advocate here for the implementation of the five following key climate-smart interventions, which have been shown to increase yields and decreasing CO2 outputs compared to the current practices that are largely based on the use of synthetic pesticides: 1. Sanitation at the country's borders and at the field level is the most cost-efficient way to prevent pest damage and losses from exotic pests entering new territories. 2. Good soil management strengthens the crop plant and enhances the effectiveness of all other interventions. 3. Biological control is the quickest and in the long run most cost-effective way to control invading insect pests and weeds. 4. Resistant varieties are often the only way to control already established diseases and are a mainstay control method in combination with other practices. 5. Various bio-pesticides based on viruses, bacteria and fungi against insects have been commercialized or can be produced on-farm; they are to replace synthetic pesticides, which continue to have large negative impacts on the environment and human health. To apply these five practices, new decision-support and climate services tools should be used to empower low-literacy farmers to take timely decisions about pest control and to act as business partners. Meanwhile, all actors in the pest control community should account for their environmental costs, which up to now are born solely by the community, while profits from pesticide sales are pocketed privately. To successfully disseminate these practices across the continent, enhanced and harmonized policy support is required.
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Affiliation(s)
- Peter Neuenschwander
- International Institute of Tropical Agriculture (IITA), Cotonou, Benin
- Corresponding author.
| | | | - Hugo De Groote
- The International Maize and Wheat Improvement Center (CIMMYT), Nairobi, Kenya
| | | | - Manuele Tamò
- International Institute of Tropical Agriculture (IITA), Cotonou, Benin
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4
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Different strategies to confront maize streak disease based on fractional optimal control formulation. CHAOS SOLITONS & FRACTALS 2022. [DOI: 10.1016/j.chaos.2022.112699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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5
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Vilanova ES, Ramos A, de Oliveira MCS, Esteves MB, Gonçalves MC, Lopes JRS. First Report of a Mastrevirus ( Geminiviridae) Transmitted by the Corn Leafhopper. PLANT DISEASE 2022; 106:1330-1333. [PMID: 34854758 DOI: 10.1094/pdis-09-21-1882-sc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Maize striate mosaic virus (MSMV; genus Mastrevirus) was recently reported in maize plants in Brazil and also detected by metagenomic analyses in the corn leafhopper, Dalbulus maidis (DeLong & Wolcott). Although these findings suggested that D. maidis is a potential vector, no transmission studies have been performed. Here, we tested the transmission of MSMV by D. maidis from field-collected infected plants and plants infected with MSMV via leafhopper-mediated transmission in the laboratory; all plants were confirmed positive for MSMV by PCR. In each one of three transmission replicates, aviruliferous D. maidis nymphs and adults were confined together on a source plant during a 4-day acquisition access period (AAP) and subsequently transferred to healthy maize seedlings (10 individuals per test plant) in a series of 4-day inoculation access periods (IAPs). We also tested transmission by the corn aphid, Rhopalosiphum maidis (Fitch) and by mechanical inoculation of healthy maize seedlings. Only D. maidis transmitted MSMV, with overall transmission rates of 29.4 and 39.5% on field-collected infected plants and 18.5% on infected plants in laboratory. D. maidis transmitted MSMV until the third (8 to 12 days after the AAP) or fourth successive IAP (12 to 16 days), with gradual loss in transmission efficiency and rate of viruliferous insects over time, suggesting a persistent but nonpropagative mode of transmission. Infected test plants showed mottling symptoms with mild chlorotic streaks and height reduction. This is the first report of transmission of a mastrevirus by D. maidis, facilitating the completion of Koch's postulate for MSMV.
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Affiliation(s)
- Euclides S Vilanova
- Department of Entomology and Acarology, Escola Superior de Agricultura Luiz de Queiroz, University of São Paulo, Piracicaba, SP 13418-900, Brazil
| | - Anderson Ramos
- Department of Entomology and Acarology, Escola Superior de Agricultura Luiz de Queiroz, University of São Paulo, Piracicaba, SP 13418-900, Brazil
| | | | - Mariana B Esteves
- Department of Entomology and Acarology, Escola Superior de Agricultura Luiz de Queiroz, University of São Paulo, Piracicaba, SP 13418-900, Brazil
| | - Marcos C Gonçalves
- Crop Protection Research Center, Instituto Biológico, São Paulo, SP 04014-002, Brazil
| | - João R S Lopes
- Department of Entomology and Acarology, Escola Superior de Agricultura Luiz de Queiroz, University of São Paulo, Piracicaba, SP 13418-900, Brazil
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6
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Sharma SK, Gupta OP, Pathaw N, Sharma D, Maibam A, Sharma P, Sanasam J, Karkute SG, Kumar S, Bhattacharjee B. CRISPR-Cas-Led Revolution in Diagnosis and Management of Emerging Plant Viruses: New Avenues Toward Food and Nutritional Security. Front Nutr 2022; 8:751512. [PMID: 34977113 PMCID: PMC8716883 DOI: 10.3389/fnut.2021.751512] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 10/31/2021] [Indexed: 12/14/2022] Open
Abstract
Plant viruses pose a serious threat to agricultural production systems worldwide. The world's population is expected to reach the 10-billion mark by 2057. Under the scenario of declining cultivable land and challenges posed by rapidly emerging and re-emerging plant pathogens, conventional strategies could not accomplish the target of keeping pace with increasing global food demand. Gene-editing techniques have recently come up as promising options to enable precise changes in genomes with greater efficiency to achieve the target of higher crop productivity. Of genome engineering tools, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) proteins have gained much popularity, owing to their simplicity, reproducibility, and applicability in a wide range of species. Also, the application of different Cas proteins, such as Cas12a, Cas13a, and Cas9 nucleases, has enabled the development of more robust strategies for the engineering of antiviral mechanisms in many plant species. Recent studies have revealed the use of various CRISPR-Cas systems to either directly target a viral gene or modify a host genome to develop viral resistance in plants. This review provides a comprehensive record of the use of the CRISPR-Cas system in the development of antiviral resistance in plants and discusses its applications in the overall enhancement of productivity and nutritional landscape of cultivated plant species. Furthermore, the utility of this technique for the detection of various plant viruses could enable affordable and precise in-field or on-site detection. The futuristic potential of CRISPR-Cas technologies and possible challenges with their use and application are highlighted. Finally, the future of CRISPR-Cas in sustainable management of viral diseases, and its practical utility and regulatory guidelines in different parts of the globe are discussed systematically.
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Affiliation(s)
| | - Om Prakash Gupta
- Division of Quality & Basic Science, ICAR-Indian Institute of Wheat and Barley Research, Karnal, India
| | - Neeta Pathaw
- ICAR Research Complex for NEH Region, Manipur Centre, Imphal, India
| | - Devender Sharma
- Crop Improvement Division, ICAR-Vivekananda Parvatiya Krishi Anusandhan Sansthan, Almora, India
| | - Albert Maibam
- ICAR Research Complex for NEH Region, Manipur Centre, Imphal, India
| | - Parul Sharma
- Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, India
| | - Jyotsana Sanasam
- ICAR Research Complex for NEH Region, Manipur Centre, Imphal, India
| | - Suhas Gorakh Karkute
- Division of Crop Improvement, ICAR-Indian Institute of Vegetable Research, Varanasi, India
| | - Sandeep Kumar
- Department of Plant Pathology, Odisha University of Agriculture & Technology, Bhubaneswar, India
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7
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Emeraghi M, Achigan-Dako EG, Nwaoguala CNC, Oselebe H. Maize streak virus research in Africa: an end or a crossroad. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2021; 134:3785-3803. [PMID: 34309683 DOI: 10.1007/s00122-021-03914-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 07/10/2021] [Indexed: 06/13/2023]
Abstract
The economic importance of the maize streak virus disease to the African maize production dynamic is to be appreciated now more than ever due to the preponderant influence of a changing climate. Continued dependence on a single major-effect quantitative trait locus (QTL) called Msv1 on Chromosome 1 of Maize (Zea mays L.) is not guaranteed to ensure durable resistance to the causal pathogen. With over ten decades of research on the disease and its associated host plant resistance mechanisms, it is pertinent to consider future approaches to attaining durability by looking to the synergistic roles of moderate- and minor-effect QTLs located on other chromosomes so as to facilitate a secure farming system for sub-Saharan Africa. For this review, more than 40 publications relating to maize streak disease research were methodically analysed with about 30% making specific reference to conventional, molecular and transgenic approaches employed in introgressing, maintaining and improving streak resistance in maize. A meta-analysis of mapped QTLs conferring streak resistance was conducted in a bid to reveal any inter-dependence or co-localization of resistant loci and to aid decision-making for marker-assisted breeding. With the changing climatic conditions around the globe, man's preparedness in the event of an epidemic following any evolutionary process in the streak viral genome was determined as insufficient. Modern breeding approaches including gene pyramiding that could be considered in maize breeding programmes to ensure durability for streak resistance were proposed while improving maize for other abiotic stress tolerance, particularly drought.
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Affiliation(s)
- Mary Emeraghi
- Laboratory of Genetics, Biotechnology and Seed Science, Faculty of Agronomic Sciences, University of Abomey-Calavi, 01BP526, Cotonou, Republic of Benin
- Department of Agronomy and Environmental Management, Faculty of Agriculture and Agricultural Technology, Benson Idahosa University, Benin City, Nigeria
| | - Enoch G Achigan-Dako
- Laboratory of Genetics, Biotechnology and Seed Science, Faculty of Agronomic Sciences, University of Abomey-Calavi, 01BP526, Cotonou, Republic of Benin.
| | - Chibuzo N C Nwaoguala
- Department of Crop Science, Faculty of Agriculture, University of Benin, Benin City, Nigeria
| | - Happiness Oselebe
- Department of Crop Production and Landscape Management, Faculty of Agriculture and Resource Management, Ebonyi State University, Abakaliki, Nigeria
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8
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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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9
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Abstract
Plants are vital for man and many species. They are sources of food, medicine, fiber for clothes and materials for shelter. They are a fundamental part of a healthy environment. However, plants are subject to virus diseases. In plants most of the virus propagation is done by a vector. The traditional way of controlling the insects is to use insecticides that have a negative effect on the environment. A more environmentally friendly way to control the insects is to use predators that will prey on the vector, such as birds or bats. In this paper we modify a plant-virus propagation model with delays. The model is written using delay differential equations. However, it can also be expressed in terms of biochemical reactions, which is more realistic for small populations. Since there are always variations in the populations, errors in the measured values and uncertainties, we use two methods to introduce randomness: stochastic differential equations and the Gillespie algorithm. We present numerical simulations. The Gillespie method produces good results for plant-virus population models.
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10
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Alemneh HT, Kassa AS, Godana AA. An optimal control model with cost effectiveness analysis of Maize streak virus disease in maize plant. Infect Dis Model 2021; 6:169-182. [PMID: 33474519 PMCID: PMC7788099 DOI: 10.1016/j.idm.2020.12.001] [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: 10/26/2020] [Revised: 11/22/2020] [Accepted: 12/07/2020] [Indexed: 11/19/2022] Open
Abstract
In this paper we formulated and analyzed an optimal deterministic eco-epidemiological model for the dynamics of maize streak virus (MSV) and examine the best strategy to fight maize population from maize streak disease (MSD). The optimal control model is developed with three control interventions, namely prevention (u 1), quarantine (u 2) and chemical control (u 3). To achieve an optimal control strategy, we used the Pontryagin's maximum principle obtain the Hamiltonian, the adjoint variables, the characterization of the controls and the optimality system. Numerical simulations are performed using Forward-backward sweep iterative method. The findings show that each integrated strategy is able to mitigate the disease in the specified time. However due to limited resources, it is important to find a cost-effective strategy. Using Incremental Cost-Effectiveness Ratio(ICER) a cost-effectiveness analysis is investigated and determined that the combination of prevention and quarantine is the best cost-effective strategy from the other integrated strategies. Therefore, policymakers and stakeholders should apply the integrated intervention to stop the spread of MSV in the maize population.
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Affiliation(s)
- Haileyesus Tessema Alemneh
- Department of Mathematics, College of Natural and Computational Sciences, University of Gondar, Gondar, Ethiopia
- Pan African University Institute of Basic Sciences, Technology and Innovation, Nairobi, Kenya
- Corresponding author. Department of Mathematics, College of Natural and Computational Sciences, University of Gondar, Gondar, Ethiopia.
| | - Assefa Sintayehu Kassa
- Department of Plant Sciences, College of Agriculture and Rural Transformation, University of Gondar, Gondar, Ethiopia
| | - Anteneh Asmare Godana
- Department of Statistics, College of Natural and Computational Sciences, University of Gondar, Gondar, Ethiopia
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11
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Disease Pandemics and Major Epidemics Arising from New Encounters between Indigenous Viruses and Introduced Crops. Viruses 2020; 12:v12121388. [PMID: 33291635 PMCID: PMC7761969 DOI: 10.3390/v12121388] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 01/13/2023] Open
Abstract
Virus disease pandemics and epidemics that occur in the world’s staple food crops pose a major threat to global food security, especially in developing countries with tropical or subtropical climates. Moreover, this threat is escalating rapidly due to increasing difficulties in controlling virus diseases as climate change accelerates and the need to feed the burgeoning global population escalates. One of the main causes of these pandemics and epidemics is the introduction to a new continent of food crops domesticated elsewhere, and their subsequent invasion by damaging virus diseases they never encountered before. This review focusses on providing historical and up-to-date information about pandemics and major epidemics initiated by spillover of indigenous viruses from infected alternative hosts into introduced crops. This spillover requires new encounters at the managed and natural vegetation interface. The principal virus disease pandemic examples described are two (cassava mosaic, cassava brown streak) that threaten food security in sub-Saharan Africa (SSA), and one (tomato yellow leaf curl) doing so globally. A further example describes a virus disease pandemic threatening a major plantation crop producing a vital food export for West Africa (cacao swollen shoot). Also described are two examples of major virus disease epidemics that threaten SSA’s food security (rice yellow mottle, groundnut rosette). In addition, brief accounts are provided of two major maize virus disease epidemics (maize streak in SSA, maize rough dwarf in Mediterranean and Middle Eastern regions), a major rice disease epidemic (rice hoja blanca in the Americas), and damaging tomato tospovirus and begomovirus disease epidemics of tomato that impair food security in different world regions. For each pandemic or major epidemic, the factors involved in driving its initial emergence, and its subsequent increase in importance and geographical distribution, are explained. Finally, clarification is provided over what needs to be done globally to achieve effective management of severe virus disease pandemics and epidemics initiated by spillover events.
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12
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Monjane AL, Dellicour S, Hartnady P, Oyeniran KA, Owor BE, Bezuidenhout M, Linderme D, Syed RA, Donaldson L, Murray S, Rybicki EP, Kvarnheden A, Yazdkhasti E, Lefeuvre P, Froissart R, Roumagnac P, Shepherd DN, Harkins GW, Suchard MA, Lemey P, Varsani A, Martin DP. Symptom evolution following the emergence of maize streak virus. eLife 2020; 9:51984. [PMID: 31939738 PMCID: PMC7034976 DOI: 10.7554/elife.51984] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 01/14/2020] [Indexed: 11/24/2022] Open
Abstract
For pathogens infecting single host species evolutionary trade-offs have previously been demonstrated between pathogen-induced mortality rates and transmission rates. It remains unclear, however, how such trade-offs impact sub-lethal pathogen-inflicted damage, and whether these trade-offs even occur in broad host-range pathogens. Here, we examine changes over the past 110 years in symptoms induced in maize by the broad host-range pathogen, maize streak virus (MSV). Specifically, we use the quantified symptom intensities of cloned MSV isolates in differentially resistant maize genotypes to phylogenetically infer ancestral symptom intensities and check for phylogenetic signal associated with these symptom intensities. We show that whereas symptoms reflecting harm to the host have remained constant or decreased, there has been an increase in how extensively MSV colonizes the cells upon which transmission vectors feed. This demonstrates an evolutionary trade-off between amounts of pathogen-inflicted harm and how effectively viruses position themselves within plants to enable onward transmission.
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Affiliation(s)
- Adérito L Monjane
- Fish Health Research Group, Norwegian Veterinary Institute, Oslo, Norway.,Department of Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Simon Dellicour
- Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory for Clinical and Epidemiological Virology, KU Leuven - University of Leuven, Leuven, Belgium.,Spatial Epidemiology Laboratory (SpELL), Université Libre de Bruxelles, Brussels, Belgium
| | - Penelope Hartnady
- Computational Biology Division, Department of Integrative Biomedical Sciences, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Observatory, Cape Town, South Africa
| | - Kehinde A Oyeniran
- Computational Biology Division, Department of Integrative Biomedical Sciences, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Observatory, Cape Town, South Africa
| | - Betty E Owor
- Department of Agricultural Production, School of Agricultural Sciences, Makerere University, Kampala, Uganda
| | - Marion Bezuidenhout
- Molecular and Cell Biology Department, University of Cape Town, Cape Town, South Africa
| | - Daphné Linderme
- Molecular and Cell Biology Department, University of Cape Town, Cape Town, South Africa
| | - Rizwan A Syed
- Molecular and Cell Biology Department, University of Cape Town, Cape Town, South Africa
| | - Lara Donaldson
- Molecular and Cell Biology Department, University of Cape Town, Cape Town, South Africa
| | - Shane Murray
- Molecular and Cell Biology Department, University of Cape Town, Cape Town, South Africa
| | - Edward P Rybicki
- Molecular and Cell Biology Department, University of Cape Town, Cape Town, South Africa
| | - Anders Kvarnheden
- Department of Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Elham Yazdkhasti
- Department of Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | | | - Rémy Froissart
- University of Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut de recherche pour le développement (IRD), UMR 5290, Maladie Infectieuses & Vecteurs: Écologie, Génétique Évolution & Contrôle" (MIVEGEC), Montpellier, France
| | - Philippe Roumagnac
- CIRAD, BGPI, Montpellier, France.,BGPI, INRA, CIRAD, SupAgro, Univ Montpellier, Montpellier, France
| | - Dionne N Shepherd
- Molecular and Cell Biology Department, University of Cape Town, Cape Town, South Africa.,Research Office, University of Cape Town, Cape Town, South Africa
| | - Gordon W Harkins
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Bellville, South Africa
| | - Marc A Suchard
- Department of Biomathematics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, United States
| | - Philippe Lemey
- Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory for Clinical and Epidemiological Virology, KU Leuven - University of Leuven, Leuven, Belgium
| | - Arvind Varsani
- The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, United States.,Structural Biology Research Unit, Department of Integrative Biomedical Sciences, University of Cape Town, Cape Town, South Africa
| | - Darren P Martin
- Computational Biology Division, Department of Integrative Biomedical Sciences, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Observatory, Cape Town, South Africa
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13
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Bennett A, Rodriguez D, Lister S, Boulton M, McKenna R, Agbandje-McKenna M. Assembly and disassembly intermediates of maize streak geminivirus. Virology 2018; 525:224-236. [PMID: 30300759 DOI: 10.1016/j.virol.2018.09.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/16/2018] [Accepted: 09/16/2018] [Indexed: 11/17/2022]
Abstract
Maize streak virus (MSV) belongs to the Geminiviridae. Four forms of MSV coat protein (CP) assemblages were isolated from infected plants: geminate capsids, T = 1 icosahedral capsids, pentamers and decamers of CPs. Sequential exposure of geminate capsids to increasing pH, from 4.8 to 7.2 was used to monitor capsid disassembly. The capsids remain intact at pH4.8, disassemble to decamers and pentamers by pH6.4 and aggregate by pH7.2. Similarly, high salt and divalent cations cause disassembly. The disassembly process was reversed in low pH and low salt, but resulted in empty (no DNA) single and geminate capsid assemblies. This is likely due to disruption of CP-DNA interactions under acidic conditions and suggests a mechanism of capsid assembly in which the genome is packaged into preformed empty capsids. The pH assay developed in this study provides a method for characterizing the conditions that are the determinants of geminivirus assembly and disassembly.
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Affiliation(s)
- Antonette Bennett
- Department of Biochemistry and Molecular Biology, College of Medicine, Center for Structural Biology, McKnight Brain Institute, University of Florida, Gainesville, FL 32610-0245, United States
| | - David Rodriguez
- Department of Biochemistry and Molecular Biology, College of Medicine, Center for Structural Biology, McKnight Brain Institute, University of Florida, Gainesville, FL 32610-0245, United States
| | - Samantha Lister
- John Innes Center, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK
| | - Margaret Boulton
- John Innes Center, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK
| | - Robert McKenna
- Department of Biochemistry and Molecular Biology, College of Medicine, Center for Structural Biology, McKnight Brain Institute, University of Florida, Gainesville, FL 32610-0245, United States
| | - Mavis Agbandje-McKenna
- Department of Biochemistry and Molecular Biology, College of Medicine, Center for Structural Biology, McKnight Brain Institute, University of Florida, Gainesville, FL 32610-0245, United States.
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Dhau I, Adam E, Mutanga O, Ayisi KK. Detecting the severity of maize streak virus infestations in maize crop using in situ hyperspectral data. ACTA ACUST UNITED AC 2017. [DOI: 10.1080/0035919x.2017.1370034] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Inos Dhau
- School of Agricultural and Environmental Sciences, Department of Geography and Environmental Studies, University of Limpopo, P. Bag X1106 Sovenga 0727, Polokwane, South Africa
- Risk and Vulnerability Science Centre/VLIR-IUC Programme, University of Limpopo, P. Bag X1106 Sovenga 0727, Polokwane, South Africa
| | - Elhadi Adam
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa
| | - Onisimo Mutanga
- School of Agriculture, Earth and Environmental Sciences, Pietermaritzburg Campus, University of KwaZulu-Natal, Scottsville P/Bag X01, Pietermaritzburg 3209, South Africa
| | - Kingsley K. Ayisi
- Risk and Vulnerability Science Centre/VLIR-IUC Programme, University of Limpopo, P. Bag X1106 Sovenga 0727, Polokwane, South Africa
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15
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Park YS, Bae DW, Ryu CM. Aboveground Whitefly Infestation Modulates Transcriptional Levels of Anthocyanin Biosynthesis and Jasmonic Acid Signaling-Related Genes and Augments the Cope with Drought Stress of Maize. PLoS One 2015; 10:e0143879. [PMID: 26630288 PMCID: PMC4667997 DOI: 10.1371/journal.pone.0143879] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 11/10/2015] [Indexed: 11/18/2022] Open
Abstract
Up to now, the potential underlying molecular mechanisms by which maize (Zea mays L.) plants elicit defense responses by infestation with a phloem feeding insect whitefly [Bemisia tabaci (Genn.)] have been barely elucidated against (a)biotic stresses. To fill this gap of current knowledge maize plants were infested with whitefly and these plants were subsequently assessed the levels of water loss. To understand the mode of action, plant hormone contents and the stress-related mRNA expression were evaluated. Whitefly-infested maize plants did not display any significant phenotypic differences in above-ground tissues (infested site) compared with controls. By contrast, root (systemic tissue) biomass was increased by 2-fold by whitefly infestation. The levels of endogenous indole-3-acetic acid (IAA), jasmonic acid (JA), and hydrogen peroxide (H2O2) were significantly higher in whitefly-infested plants. The biosynthetic or signaling-related genes for JA and anthocyanins were highly up-regulated. Additionally, we found that healthier plants were obtained in whitefly-infested plants under drought conditions. The weight of whitefly-infested plants was approximately 20% higher than that of control plants at 14 d of drought treatment. The drought tolerance-related genes, ZmbZIP72, ZmSNAC1, and ZmABA1, were highly expressed in the whitefly-infected plants. Collectively, our results suggest that IAA/JA-derived maize physiological changes and correlation of H2O2 production and water loss are modulated by above-ground whitefly infestation in maize plants.
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Affiliation(s)
- Yong-Soon Park
- Molecular Phytobacteriology Laboratory, KRIBB, Daejeon, 305–806, South Korea
- Agricultural Microbiology Division, National Academy of Agricultural Science, RDA, Wanju, 565–851, South Korea
| | - Dong-Won Bae
- Central Instrument Facility, Gyeongsang National University, Jinju, 660–701, South Korea
| | - Choong-Min Ryu
- Molecular Phytobacteriology Laboratory, KRIBB, Daejeon, 305–806, South Korea
- Biosystems and Bioengineering Program, University of Science and Technology (UST), Daejeon, 305–350, South Korea
- * E-mail:
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16
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Roossinck MJ, García-Arenal F. Ecosystem simplification, biodiversity loss and plant virus emergence. Curr Opin Virol 2015; 10:56-62. [PMID: 25638504 PMCID: PMC7102708 DOI: 10.1016/j.coviro.2015.01.005] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 01/08/2015] [Accepted: 01/14/2015] [Indexed: 01/02/2023]
Abstract
Plant viruses can emerge into crops from wild plant hosts, or conversely from domestic (crop) plants into wild hosts. Changes in ecosystems, including loss of biodiversity and increases in managed croplands, can impact the emergence of plant virus disease. Although data are limited, in general the loss of biodiversity is thought to contribute to disease emergence. More in-depth studies have been done for human viruses, but studies with plant viruses suggest similar patterns, and indicate that simplification of ecosystems through increased human management may increase the emergence of viral diseases in crops.
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Affiliation(s)
- Marilyn J Roossinck
- Department of Plant Pathology and Environmental Microbiology, Center for Infectious Disease Dynamics, Pennsylvania State University, USA; Murdoch University, Perth, Australia.
| | - Fernando García-Arenal
- Centro de Biotecnología y Genómica de Plantas UPM-INIA, and E.T.S.I. Agrónomos, Campus de Montegancedo, Universidad Politécnica de Madrid, Spain
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17
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Rybicki EP. A Top Ten list for economically important plant viruses. Arch Virol 2014; 160:17-20. [PMID: 25430908 DOI: 10.1007/s00705-014-2295-9] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/20/2014] [Indexed: 12/31/2022]
Abstract
The concept of "Top Ten" lists of plant pathogens is in vogue in recent years, and plant viruses are no exception. However, the only list available has more to do with historical and scientific worth than it has to do with economic impact on humans and their animals. This review will discuss the most important plant viruses that cause serious harm to food plants that sustain the bulk of humankind.
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Affiliation(s)
- Edward P Rybicki
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, PB Rondebosch, Cape Town, 7701, South Africa,
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18
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Shepherd DN, Dugdale B, Martin DP, Varsani A, Lakay FM, Bezuidenhout ME, Monjane AL, Thomson JA, Dale J, Rybicki EP. Inducible resistance to maize streak virus. PLoS One 2014; 9:e105932. [PMID: 25166274 PMCID: PMC4148390 DOI: 10.1371/journal.pone.0105932] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 07/28/2014] [Indexed: 11/18/2022] Open
Abstract
Maize streak virus (MSV), which causes maize streak disease (MSD), is the major viral pathogenic constraint on maize production in Africa. Type member of the Mastrevirus genus in the family Geminiviridae, MSV has a 2.7 kb, single-stranded circular DNA genome encoding a coat protein, movement protein, and the two replication-associated proteins Rep and RepA. While we have previously developed MSV-resistant transgenic maize lines constitutively expressing "dominant negative mutant" versions of the MSV Rep, the only transgenes we could use were those that caused no developmental defects during the regeneration of plants in tissue culture. A better transgene expression system would be an inducible one, where resistance-conferring transgenes are expressed only in MSV-infected cells. However, most known inducible transgene expression systems are hampered by background or "leaky" expression in the absence of the inducer. Here we describe an adaptation of the recently developed INPACT system to express MSV-derived resistance genes in cell culture. Split gene cassette constructs (SGCs) were developed containing three different transgenes in combination with three different promoter sequences. In each SGC, the transgene was split such that it would be translatable only in the presence of an infecting MSV's replication associated protein. We used a quantitative real-time PCR assay to show that one of these SGCs (pSPLITrepIII-Rb-Ubi) inducibly inhibits MSV replication as efficiently as does a constitutively expressed transgene that has previously proven effective in protecting transgenic maize from MSV. In addition, in our cell-culture based assay pSPLITrepIII-Rb-Ubi inhibited replication of diverse MSV strains, and even, albeit to a lesser extent, of a different mastrevirus species. The application of this new technology to MSV resistance in maize could allow a better, more acceptable product.
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Affiliation(s)
- Dionne N. Shepherd
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town, South Africa
- * E-mail:
| | - Benjamin Dugdale
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Darren P. Martin
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, Cape Town, South Africa
- Centre for High-Performance Computing, Rosebank, Cape Town, South Africa
| | - Arvind Varsani
- School of Biological Sciences and Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
- Department of Plant Pathology and Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- Electron Microscope Unit, Division of Medical Biochemistry, Department of Clinical Laboratory Sciences, University of Cape Town, Observatory, Cape Town, South Africa
| | - Francisco M. Lakay
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town, South Africa
| | - Marion E. Bezuidenhout
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town, South Africa
| | - Adérito L. Monjane
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, Cape Town, South Africa
| | - Jennifer A. Thomson
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town, South Africa
| | - James Dale
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Edward P. Rybicki
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, Cape Town, South Africa
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19
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Mauck K, Bosque-Pérez NA, Eigenbrode SD, De Moraes CM, Mescher MC. Transmission mechanisms shape pathogen effects on host-vector interactions: evidence from plant viruses. Funct Ecol 2012. [DOI: 10.1111/j.1365-2435.2012.02026.x] [Citation(s) in RCA: 268] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Kerry Mauck
- Department of Entomology; The Pennsylvania State University; University Park; Pennsylvania; 16802; USA
| | - Nilsa A. Bosque-Pérez
- Department of Plant, Soil and Entomological Sciences; University of Idaho; Moscow; Idaho; 83844-2339; USA
| | - Sanford D. Eigenbrode
- Department of Plant, Soil and Entomological Sciences; University of Idaho; Moscow; Idaho; 83844-2339; USA
| | - Consuelo M. De Moraes
- Department of Entomology; The Pennsylvania State University; University Park; Pennsylvania; 16802; USA
| | - Mark C. Mescher
- Department of Entomology; The Pennsylvania State University; University Park; Pennsylvania; 16802; USA
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20
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Monjane AL, van der Walt E, Varsani A, Rybicki EP, Martin DP. Recombination hotspots and host susceptibility modulate the adaptive value of recombination during maize streak virus evolution. BMC Evol Biol 2011; 11:350. [PMID: 22136133 PMCID: PMC3280948 DOI: 10.1186/1471-2148-11-350] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 12/02/2011] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Maize streak virus -strain A (MSV-A; Genus Mastrevirus, Family Geminiviridae), the maize-adapted strain of MSV that causes maize streak disease throughout sub-Saharan Africa, probably arose between 100 and 200 years ago via homologous recombination between two MSV strains adapted to wild grasses. MSV recombination experiments and analyses of natural MSV recombination patterns have revealed that this recombination event entailed the exchange of the movement protein - coat protein gene cassette, bounded by the two genomic regions most prone to recombination in mastrevirus genomes; the first surrounding the virion-strand origin of replication, and the second around the interface between the coat protein gene and the short intergenic region. Therefore, aside from the likely adaptive advantages presented by a modular exchange of this cassette, these specific breakpoints may have been largely predetermined by the underlying mechanisms of mastrevirus recombination. To investigate this hypothesis, we constructed artificial, low-fitness, reciprocal chimaeric MSV genomes using alternating genomic segments from two MSV strains; a grass-adapted MSV-B, and a maize-adapted MSV-A. Between them, each pair of reciprocal chimaeric genomes represented all of the genetic material required to reconstruct - via recombination - the highly maize-adapted MSV-A genotype, MSV-MatA. We then co-infected a selection of differentially MSV-resistant maize genotypes with pairs of reciprocal chimaeras to determine the efficiency with which recombination would give rise to high-fitness progeny genomes resembling MSV-MatA. RESULTS Recombinants resembling MSV-MatA invariably arose in all of our experiments. However, the accuracy and efficiency with which the MSV-MatA genotype was recovered across all replicates of each experiment depended on the MSV susceptibility of the maize genotypes used and the precise positions - in relation to known recombination hotspots - of the breakpoints required to re-create MSV-MatA. Although the MSV-sensitive maize genotype gave rise to the greatest variety of recombinants, the measured fitness of each of these recombinants correlated with their similarity to MSV-MatA. CONCLUSIONS The mechanistic predispositions of different MSV genomic regions to recombination can strongly influence the accessibility of high-fitness MSV recombinants. The frequency with which the fittest recombinant MSV genomes arise also correlates directly with the escalating selection pressures imposed by increasingly MSV-resistant maize hosts.
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Affiliation(s)
- Adérito L Monjane
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
| | | | - Arvind Varsani
- Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
- Electron Microscope Unit, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
| | - Edward P Rybicki
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
- Computational Biology Group, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Darren P Martin
- Computational Biology Group, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, 7925, Cape Town, South Africa
- Centre for High-Performance Computing, Rosebank, Cape Town, South Africa
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21
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Monjane AL, Harkins GW, Martin DP, Lemey P, Lefeuvre P, Shepherd DN, Oluwafemi S, Simuyandi M, Zinga I, Komba EK, Lakoutene DP, Mandakombo N, Mboukoulida J, Semballa S, Tagne A, Tiendrébéogo F, Erdmann JB, van Antwerpen T, Owor BE, Flett B, Ramusi M, Windram OP, Syed R, Lett JM, Briddon RW, Markham PG, Rybicki EP, Varsani A. Reconstructing the history of maize streak virus strain a dispersal to reveal diversification hot spots and its origin in southern Africa. J Virol 2011; 85:9623-36. [PMID: 21715477 PMCID: PMC3165777 DOI: 10.1128/jvi.00640-11] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 06/21/2011] [Indexed: 01/11/2023] Open
Abstract
Maize streak virus strain A (MSV-A), the causal agent of maize streak disease, is today one of the most serious biotic threats to African food security. Determining where MSV-A originated and how it spread transcontinentally could yield valuable insights into its historical emergence as a crop pathogen. Similarly, determining where the major extant MSV-A lineages arose could identify geographical hot spots of MSV evolution. Here, we use model-based phylogeographic analyses of 353 fully sequenced MSV-A isolates to reconstruct a plausible history of MSV-A movements over the past 150 years. We show that since the probable emergence of MSV-A in southern Africa around 1863, the virus spread transcontinentally at an average rate of 32.5 km/year (95% highest probability density interval, 15.6 to 51.6 km/year). Using distinctive patterns of nucleotide variation caused by 20 unique intra-MSV-A recombination events, we tentatively classified the MSV-A isolates into 24 easily discernible lineages. Despite many of these lineages displaying distinct geographical distributions, it is apparent that almost all have emerged within the past 4 decades from either southern or east-central Africa. Collectively, our results suggest that regular analysis of MSV-A genomes within these diversification hot spots could be used to monitor the emergence of future MSV-A lineages that could affect maize cultivation in Africa.
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Affiliation(s)
- Adérito L. Monjane
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
| | - Gordon W. Harkins
- South African National Bioinformatics Institute, University of the Western Cape, Cape Town, South Africa
| | - Darren P. Martin
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, 7925, Cape Town, South Africa
- Centre for High-Performance Computing, Rosebank, Cape Town, South Africa
| | - Philippe Lemey
- Department of Microbiology and Immunology, Rega Institute, K.U. Leuven, Leuven, Belgium
| | - Pierre Lefeuvre
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, 7925, Cape Town, South Africa
- CIRAD, UMR 53 PVBMT CIRAD-Université de la Réunion, Pôle de Protection des Plantes, 97410, Saint Pierre, La Réunion, France
| | - Dionne N. Shepherd
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
| | - Sunday Oluwafemi
- Department of Crop Production, Soil and Environmental Management, Bowen University, Iwo, Osun State, P.M.B. 284, Nigeria
| | | | - Innocent Zinga
- LASBAD Laboratory, Faculty of Sciences, University of Bangui, BP 908 Bangui, Central African Republic
| | - Ephrem K. Komba
- LASBAD Laboratory, Faculty of Sciences, University of Bangui, BP 908 Bangui, Central African Republic
| | - Didier P. Lakoutene
- LASBAD Laboratory, Faculty of Sciences, University of Bangui, BP 908 Bangui, Central African Republic
| | - Noella Mandakombo
- LASBAD Laboratory, Faculty of Sciences, University of Bangui, BP 908 Bangui, Central African Republic
| | - Joseph Mboukoulida
- LASBAD Laboratory, Faculty of Sciences, University of Bangui, BP 908 Bangui, Central African Republic
| | - Silla Semballa
- LASBAD Laboratory, Faculty of Sciences, University of Bangui, BP 908 Bangui, Central African Republic
| | - Appolinaire Tagne
- Cereals Research Program, Institute of Agricultural Research for Development, Box 2067 Messa, Yaounde, Cameroon
| | - Fidèle Tiendrébéogo
- Centre de Recherche en Sciences Biologiques Alimentaires et Nutritionnelles (CRSBAN), UFR/SVT Université de Ouagadougou, 03 BP 7131 Ouagadougou 03, Burkina Faso
| | - Julia B. Erdmann
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
- Institute of Biology, Department of Molecular Biology and Plant Virology, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - Tania van Antwerpen
- South African Sugarcane Research Institute, Mount Edgecombe, KwaZulu Natal, South Africa
| | - Betty E. Owor
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom, CB2 3EA
| | - Bradley Flett
- Crop Protection, ARC-Grain Crops Institute, Potchefstroom 2520, South Africa
| | - Moses Ramusi
- Crop Protection, ARC-Grain Crops Institute, Potchefstroom 2520, South Africa
| | - Oliver P. Windram
- Warwick HRI Biology Centre, University of Warwick, Wellesbourne, CV35 9EF, England
| | - Rizwan Syed
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
| | - Jean-Michel Lett
- CIRAD, UMR 53 PVBMT CIRAD-Université de la Réunion, Pôle de Protection des Plantes, 97410, Saint Pierre, La Réunion, France
| | - Rob W. Briddon
- National Institute for Biotechnology and Genetic Engineering, Jhang Road, P.O. Box 577, Faisalabad, Pakistan
| | - Peter G. Markham
- Department of Disease and Stress Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Edward P. Rybicki
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Arvind Varsani
- Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
- Electron Microscope Unit, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
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22
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The expanding field of plant virus ecology: Historical foundations, knowledge gaps, and research directions. Virus Res 2011; 159:84-94. [DOI: 10.1016/j.virusres.2011.05.010] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 03/31/2011] [Accepted: 05/09/2011] [Indexed: 11/20/2022]
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23
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Bosque-Pérez NA, Eigenbrode SD. The influence of virus-induced changes in plants on aphid vectors: Insights from luteovirus pathosystems. Virus Res 2011; 159:201-5. [DOI: 10.1016/j.virusres.2011.04.020] [Citation(s) in RCA: 151] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 04/14/2011] [Indexed: 11/29/2022]
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Genetically engineered virus-resistant plants in developing countries: current status and future prospects. Adv Virus Res 2010; 75:185-220. [PMID: 20109667 DOI: 10.1016/s0065-3527(09)07506-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Plant viruses cause severe crop losses worldwide. Conventional control strategies, such as cultural methods and biocide applications against arthropod, nematode, and plasmodiophorid vectors, have limited success at mitigating the impact of plant viruses. Planting resistant cultivars is the most effective and economical way to control plant virus diseases. Natural sources of resistance have been exploited extensively to develop virus-resistant plants by conventional breeding. Non-conventional methods have also been used successfully to confer virus resistance by transferring primarily virus-derived genes, including viral coat protein, replicase, movement protein, defective interfering RNA, non-coding RNA sequences, and protease, into susceptible plants. Non-viral genes (R genes, microRNAs, ribosome-inactivating proteins, protease inhibitors, dsRNAse, RNA modifying enzymes, and scFvs) have also been used successfully to engineer resistance to viruses in plants. Very few genetically engineered (GE) virus resistant (VR) crops have been released for cultivation and none is available yet in developing countries. However, a number of economically important GEVR crops, transformed with viral genes are of great interest in developing countries. The major issues confronting the production and deregulation of GEVR crops in developing countries are primarily socio-economic and related to intellectual property rights, biosafety regulatory frameworks, expenditure to generate GE crops and opposition by non-governmental activists. Suggestions for satisfactory resolution of these factors, presumably leading to field tests and deregulation of GEVR crops in developing countries, are given.
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Shepherd DN, Martin DP, Van Der Walt E, Dent K, Varsani A, Rybicki EP. Maize streak virus: an old and complex 'emerging' pathogen. MOLECULAR PLANT PATHOLOGY 2010; 11:1-12. [PMID: 20078771 PMCID: PMC6640477 DOI: 10.1111/j.1364-3703.2009.00568.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
UNLABELLED Maize streak virus (MSV; Genus Mastrevirus, Family Geminiviridae) occurs throughout Africa, where it causes what is probably the most serious viral crop disease on the continent. It is obligately transmitted by as many as six leafhopper species in the Genus Cicadulina, but mainly by C. mbila Naudé and C. storeyi. In addition to maize, it can infect over 80 other species in the Family Poaceae. Whereas 11 strains of MSV are currently known, only the MSV-A strain is known to cause economically significant streak disease in maize. Severe maize streak disease (MSD) manifests as pronounced, continuous parallel chlorotic streaks on leaves, with severe stunting of the affected plant and, usuallly, a failure to produce complete cobs or seed. Natural resistance to MSV in maize, and/or maize infections caused by non-maize-adapted MSV strains, can result in narrow, interrupted streaks and no obvious yield losses. MSV epidemiology is primarily governed by environmental influences on its vector species, resulting in erratic epidemics every 3-10 years. Even in epidemic years, disease incidences can vary from a few infected plants per field, with little associated yield loss, to 100% infection rates and complete yield loss. TAXONOMY The only virus species known to cause MSD is MSV, the type member of the Genus Mastrevirus in the Family Geminiviridae. In addition to the MSV-A strain, which causes the most severe form of streak disease in maize, 10 other MSV strains (MSV-B to MSV-K) are known to infect barley, wheat, oats, rye, sugarcane, millet and many wild, mostly annual, grass species. Seven other mastrevirus species, many with host and geographical ranges partially overlapping those of MSV, appear to infect primarily perennial grasses. PHYSICAL PROPERTIES MSV and all related grass mastreviruses have single-component, circular, single-stranded DNA genomes of approximately 2700 bases, encapsidated in 22 x 38-nm geminate particles comprising two incomplete T = 1 icosahedra, with 22 pentameric capsomers composed of a single 32-kDa capsid protein. Particles are generally stable in buffers of pH 4-8. DISEASE SYMPTOMS In infected maize plants, streak disease initially manifests as minute, pale, circular spots on the lowest exposed portion of the youngest leaves. The only leaves that develop symptoms are those formed after infection, with older leaves remaining healthy. As the disease progresses, newer leaves emerge containing streaks up to several millimetres in length along the leaf veins, with primary veins being less affected than secondary or tertiary veins. The streaks are often fused laterally, appearing as narrow, broken, chlorotic stripes, which may extend over the entire length of severely affected leaves. Lesion colour generally varies from white to yellow, with some virus strains causing red pigmentation on maize leaves and abnormal shoot and flower bunching in grasses. Reduced photosynthesis and increased respiration usually lead to a reduction in leaf length and plant height; thus, maize plants infected at an early stage become severely stunted, producing undersized, misshapen cobs or giving no yield at all. Yield loss in susceptible maize is directly related to the time of infection: infected seedlings produce no yield or are killed, whereas plants infected at later times are proportionately less affected. DISEASE CONTROL Disease avoidance can be practised by only planting maize during the early season when viral inoculum loads are lowest. Leafhopper vectors can also be controlled with insecticides such as carbofuran. However, the development and use of streak-resistant cultivars is probably the most effective and economically viable means of preventing streak epidemics. Naturally occurring tolerance to MSV (meaning that, although plants become systemically infected, they do not suffer serious yield losses) has been found, which has primarily been attributed to a single gene, msv-1. However, other MSV resistance genes also exist and improved resistance has been achieved by concentrating these within individual maize genotypes. Whereas true MSV immunity (meaning that plants cannot be symptomatically infected by the virus) has been achieved in lines that include multiple small-effect resistance genes together with msv-1, it has proven difficult to transfer this immunity into commercial maize genotypes. An alternative resistance strategy using genetic engineering is currently being investigated in South Africa. USEFUL WEBSITES http://www.mcb.uct.ac.za/MSV/mastrevirus.htm; http://www.danforthcenter.org/iltab/geminiviridae/geminiaccess/mastrevirus/Mastrevirus.htm.
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Affiliation(s)
- Dionne N Shepherd
- Department of Molecular and Cell Biology, University of Cape Town, PB Rondebosch, 7701, South Africa.
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Martin DP, Shepherd DN. The epidemiology, economic impact and control of maize streak disease. Food Secur 2009. [DOI: 10.1007/s12571-009-0023-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Asea G, Vivek BS, Bigirwa G, Lipps PE, Pratt RC. Validation of consensus quantitative trait loci associated with resistance to multiple foliar pathogens of maize. PHYTOPATHOLOGY 2009; 99:540-547. [PMID: 19351250 DOI: 10.1094/phyto-99-5-0540] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Maize production in sub-Saharan Africa incurs serious losses to epiphytotics of foliar diseases. Quantitative trait loci conditioning partial resistance (rQTL) to infection by causal agents of gray leaf spot (GLS), northern corn leaf blight (NCLB), and maize streak have been reported. Our objectives were to identify simple-sequence repeat (SSR) molecular markers linked to consensus rQTL and one recently identified rQTL associated with GLS, and to determine their suitability as tools for selection of improved host resistance. We conducted evaluations of disease severity phenotypes in separate field nurseries, each containing 410 F2:3 families derived from a cross between maize inbred CML202 (NCLB and maize streak resistant) and VP31 (a GLS-resistant breeding line) that possess complimentary rQTL. F2:3 families were selected for resistance based on genotypic (SSR marker), phenotypic, or combined data and the selected F3:4 families were reevaluated. Phenotypic values associated with SSR markers for consensus rQTL in bins 4.08 for GLS, 5.04 for NCLB, and 1.04 for maize streak significantly reduced disease severity in both generations based on single-factor analysis of variance and marker-interval analysis. These results were consistent with the presence of homozygous resistant parent alleles, except in bin 8.06, where markers were contributed by the NCLB-susceptible parent. Only one marker associated with resistance could be confirmed in bins 2.09 (GLS) and 3.06 (NCLB), illustrating the need for more robust rQTL discovery, fine-mapping, and validation prior to undertaking marker-based selection.
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Affiliation(s)
- Godfrey Asea
- Department of Horticulture and Crop Science, The Ohio State University, Ohio Agricultural Reserch and Development Center, Wooster, OH 44691, USA
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Ammar ED, Gargani D, Lett JM, Peterschmitt M. Large accumulations of maize streak virus in the filter chamber and midgut cells of the leafhopper vector Cicadulina mbila. Arch Virol 2009; 154:255-62. [DOI: 10.1007/s00705-008-0308-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Accepted: 12/11/2008] [Indexed: 11/29/2022]
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Biological and molecular characterization of a putative new sobemovirus infecting Imperata cylindrica and maize in Africa. Arch Virol 2008; 153:1813-20. [PMID: 18777157 DOI: 10.1007/s00705-008-0190-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Accepted: 07/27/2008] [Indexed: 10/21/2022]
Abstract
A new virus was isolated from both the grass Imperata cylindrica and maize plants that had yellow mottle symptoms in Burkina Faso, West Africa. The virus has isometric particles ca. 32 nm in diameter. The experimental host range was restricted to Rottboellia exaltata. Virions were isolated from leaves of systemically infected maize plants. Koch's postulates were completed by mechanically inoculating uninfected Imperata or maize with either purified virus or sap from infected Imperata plants. Virion preparations were used to produce a specific polyclonal antiserum, and an enzyme-linked immunosorbent assay test was set up. The full genome of the virus was sequenced, and it comprised 4,547 nucleotides. Phylogenetic studies indicated that the virus is closely related to rice yellow mottle virus, a sobemovirus that infects monocotyledons in Africa, and is more distantly related to cocksfoot mottle virus, another sobemovirus that infects monocotyledons. Although the virus can infect R. exaltata experimentally, it differs from Rottboellia yellow mottle virus, a member of a tentative species of the genus Sobemovirus that also infects monocotyledons in Africa. Particle morphology, serological properties, genomic organization, and phylogenetic analysis are all consistent with assignment of the new virus to the genus Sobemovirus. The name Imperata yellow mottle virus is proposed.
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Varsani A, Shepherd DN, Monjane AL, Owor BE, Erdmann JB, Rybicki EP, Peterschmitt M, Briddon RW, Markham PG, Oluwafemi S, Windram OP, Lefeuvre P, Lett JM, Martin DP. Recombination, decreased host specificity and increased mobility may have driven the emergence of maize streak virus as an agricultural pathogen. J Gen Virol 2008; 89:2063-2074. [PMID: 18753214 PMCID: PMC2886952 DOI: 10.1099/vir.0.2008/003590-0] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Accepted: 06/17/2008] [Indexed: 01/20/2023] Open
Abstract
Maize streak virus (MSV; family Geminiviridae, genus Mastrevirus), the causal agent of maize streak disease, ranks amongst the most serious biological threats to food security in subSaharan Africa. Although five distinct MSV strains have been currently described, only one of these - MSV-A - causes severe disease in maize. Due primarily to their not being an obvious threat to agriculture, very little is known about the 'grass-adapted' MSV strains, MSV-B, -C, -D and -E. Since comparing the genetic diversities, geographical distributions and natural host ranges of MSV-A with the other MSV strains could provide valuable information on the epidemiology, evolution and emergence of MSV-A, we carried out a phylogeographical analysis of MSVs found in uncultivated indigenous African grasses. Amongst the 83 new MSV genomes presented here, we report the discovery of six new MSV strains (MSV-F to -K). The non-random recombination breakpoint distributions detectable with these and other available mastrevirus sequences partially mirror those seen in begomoviruses, implying that the forces shaping these breakpoint patterns have been largely conserved since the earliest geminivirus ancestors. We present evidence that the ancestor of all MSV-A variants was the recombinant progeny of ancestral MSV-B and MSV-G/-F variants. While it remains unknown whether recombination influenced the emergence of MSV-A in maize, our discovery that MSV-A variants may both move between and become established in different regions of Africa with greater ease, and infect more grass species than other MSV strains, goes some way towards explaining why MSV-A is such a successful maize pathogen.
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Affiliation(s)
- Arvind Varsani
- Electron Microscope Unit, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
| | - Dionne N. Shepherd
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
| | - Adérito L. Monjane
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
| | - Betty E. Owor
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
| | - Julia B. Erdmann
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
- Institute of Biology, Department of Molecular Biology and Plant Virology, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - Edward P. Rybicki
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Anzio Road, Observatory, Cape Town 7925, South Africa
| | - Michel Peterschmitt
- CIRAD, UMR BGPI, TA A54/K, Campus International de Baillarguet, 34398 Montpellier Cedex 5, France
| | - Rob W. Briddon
- National Institute for Biotechnology and Genetic Engineering, Jhang Road, PO Box 577, Faisalabad, Pakistan
| | - Peter G. Markham
- Department of Disease and Stress Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Sunday Oluwafemi
- Department of Crop, Soil and Environmental Management, Bowen University, PMB 284, Iwo, Osun State, Nigeria
| | - Oliver P. Windram
- Warwick HRI Biology Centre, University of Warwick, Wellesbourne CV35 9EF, UK
| | - Pierre Lefeuvre
- CIRAD, UMR 53 PVBMT CIRAD-Université de la Réunion, Pôle de Protection des Plantes, Ligne Paradis, 97410 Saint Pierre, La Réunion, France
| | - Jean-Michel Lett
- CIRAD, UMR 53 PVBMT CIRAD-Université de la Réunion, Pôle de Protection des Plantes, Ligne Paradis, 97410 Saint Pierre, La Réunion, France
| | - Darren P. Martin
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Anzio Road, Observatory, Cape Town 7925, South Africa
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Hogenhout SA, Ammar ED, Whitfield AE, Redinbaugh MG. Insect vector interactions with persistently transmitted viruses. ANNUAL REVIEW OF PHYTOPATHOLOGY 2008; 46:327-59. [PMID: 18680428 DOI: 10.1146/annurev.phyto.022508.092135] [Citation(s) in RCA: 605] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The majority of described plant viruses are transmitted by insects of the Hemipteroid assemblage that includes aphids, whiteflies, leafhoppers, planthoppers, and thrips. In this review we highlight progress made in research on vector interactions of the more than 200 plant viruses that are transmitted by hemipteroid insects beginning a few hours or days after acquisition and for up to the life of the insect, i.e., in a persistent-circulative or persistent-propagative mode. These plant viruses move through the insect vector, from the gut lumen into the hemolymph or other tissues and finally into the salivary glands, from which these viruses are introduced back into the plant host during insect feeding. The movement and/or replication of the viruses in the insect vectors require specific interactions between virus and vector components. Recent investigations have resulted in a better understanding of the replication sites and tissue tropism of several plant viruses that propagate in insect vectors. Furthermore, virus and insect proteins involved in overcoming transmission barriers in the vector have been identified for some virus-vector combinations.
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Affiliation(s)
- Saskia A Hogenhout
- Department of Disease and Stress Biology, John Innes Centre, Norwich, NR4 7UH, United Kingdom.
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Shepherd DN, Mangwende T, Martin DP, Bezuidenhout M, Kloppers FJ, Carolissen CH, Monjane AL, Rybicki EP, Thomson JA. Maize streak virus-resistant transgenic maize: a first for Africa. PLANT BIOTECHNOLOGY JOURNAL 2007; 5:759-67. [PMID: 17924935 DOI: 10.1111/j.1467-7652.2007.00279.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In this article, we report transgene-derived resistance in maize to the severe pathogen maize streak virus (MSV). The mutated MSV replication-associated protein gene that was used to transform maize showed stable expression to the fourth generation. Transgenic T2 and T3 plants displayed a significant delay in symptom development, a decrease in symptom severity and higher survival rates than non-transgenic plants after MSV challenge, as did a transgenic hybrid made by crossing T2 Hi-II with the widely grown, commercial, highly MSV-susceptible, white maize genotype WM3. To the best of our knowledge, this is the first maize to be developed with transgenic MSV resistance and the first all-African-produced genetically modified crop plant.
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Affiliation(s)
- Dionne N Shepherd
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch 7701, South Africa.
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Schubert J, Habekuss A, Kazmaier K, Jeske H. Surveying cereal-infecting geminiviruses in Germany--diagnostics and direct sequencing using rolling circle amplification. Virus Res 2007; 127:61-70. [PMID: 17449126 DOI: 10.1016/j.virusres.2007.03.018] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Revised: 03/20/2007] [Accepted: 03/20/2007] [Indexed: 11/18/2022]
Abstract
Geminiviruses have spread in German cereal crops during the last few years. In order to identify and classify them, we have compared conventional techniques (enzyme-linked immunosorbent assays, polymerase chain reaction, bacterial cloning, and sequencing) with a newly developed method which uses rolling circle amplification (RCA), restriction fragment length polymorphism (RFLP), and direct sequencing without a bacterial cloning step. Whereas immunological methods utilising polyclonal antibodies were reliable for detection of geminiviruses, they did not discriminate between different German mastrevirus species, in contrast to RCA/RFLP. Direct sequencing gave high fidelity results with the same quality as conventional cloning and sequencing but with significantly reduced effort and costs. Based on a survey of field-derived cereal samples and on DNA sequences of distinct virus isolates we propose two new mastrevirus species, to be named Barley dwarf virus (BDV), and Oat dwarf virus (ODV) according to sequence differences and host range studies. The results show the applicability of RCA-based techniques for field studies and the possibility of sequencing a geminiviral genome without cloning. This approach will accelerate genomics studies of all viruses with small circular DNA genomes. In addition, RCA proves to be a reliable technique allowing for the detection of new geminivirus species as it does not depend on the knowledge of specific primers.
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Affiliation(s)
- Jörg Schubert
- Institute of Resistance Research and Pathogen Diagnostics, Federal Centre for Breeding Research on Cultivated Plants, Erwin-Baur-Str. 27, 06484 Quedlinburg, Germany
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Owor BE, Shepherd DN, Taylor NJ, Edema R, Monjane AL, Thomson JA, Martin DP, Varsani A. Successful application of FTA® Classic Card technology and use of bacteriophage ϕ29 DNA polymerase for large-scale field sampling and cloning of complete maize streak virus genomes. J Virol Methods 2007; 140:100-5. [PMID: 17174409 DOI: 10.1016/j.jviromet.2006.11.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 11/01/2006] [Accepted: 11/08/2006] [Indexed: 10/23/2022]
Abstract
Leaf samples from 155 maize streak virus (MSV)-infected maize plants were collected from 155 farmers' fields in 23 districts in Uganda in May/June 2005 by leaf-pressing infected samples onto FTA Classic Cards. Viral DNA was successfully extracted from cards stored at room temperature for 9 months. The diversity of 127 MSV isolates was analysed by PCR-generated RFLPs. Six representative isolates having different RFLP patterns and causing either severe, moderate or mild disease symptoms, were chosen for amplification from FTA cards by bacteriophage phi29 DNA polymerase using the TempliPhi system. Full-length genomes were inserted into a cloning vector using a unique restriction enzyme site, and sequenced. The 1.3-kb PCR product amplified directly from FTA-eluted DNA and used for RFLP analysis was also cloned and sequenced. Comparison of cloned whole genome sequences with those of the original PCR products indicated that the correct virus genome had been cloned and that no errors were introduced by the phi29 polymerase. This is the first successful large-scale application of FTA card technology to the field, and illustrates the ease with which large numbers of infected samples can be collected and stored for downstream molecular applications such as diversity analysis and cloning of potentially new virus genomes.
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Affiliation(s)
- Betty E Owor
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch 7701, South Africa
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35
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Vanderschuren H, Stupak M, Fütterer J, Gruissem W, Zhang P. Engineering resistance to geminiviruses--review and perspectives. PLANT BIOTECHNOLOGY JOURNAL 2007; 5:207-20. [PMID: 17309676 DOI: 10.1111/j.1467-7652.2006.00217.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Following the conceptual development of virus resistance strategies ranging from coat protein-mediated interference of virus propagation to RNA-mediated virus gene silencing, much progress has been achieved to protect plants against RNA and DNA virus infections. Geminiviruses are a major threat to world agriculture, and breeding resistant crops against these DNA viruses is one of the major challenges faced by plant virologists and biotechnologists. In this article, we review the most recent transgene-based approaches that have been developed to achieve durable geminivirus resistance. Although most of the strategies have been tested in model plant systems, they are ready to be adopted for the protection of crop plants. Furthermore, a better understanding of geminivirus gene and protein functions, as well as the native immune system which protects plants against viruses, will allow us to develop novel tools to expand our current capacity to stabilize crop production in geminivirus epidemic zones.
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Affiliation(s)
- Hervé Vanderschuren
- Institute of Plant Sciences, ETH Zurich, Universitätstrasse 2, 8092 Zurich, Switzerland
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Shepherd DN, Mangwende T, Martin DP, Bezuidenhout M, Thomson JA, Rybicki EP. Inhibition of maize streak virus (MSV) replication by transient and transgenic expression of MSV replication-associated protein mutants. J Gen Virol 2007; 88:325-336. [PMID: 17170465 DOI: 10.1099/vir.0.82338-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Maize streak disease is a severe agricultural problem in Africa and the development of maize genotypes resistant to the causal agent, Maize streak virus (MSV), is a priority. A transgenic approach to engineering MSV-resistant maize was developed and tested in this study. A pathogen-derived resistance strategy was adopted by using targeted deletions and nucleotide-substitution mutants of the multifunctional MSV replication-associated protein gene (rep). Various rep gene constructs were tested for their efficacy in limiting replication of wild-type MSV by co-bombardment of maize suspension cells together with an infectious genomic clone of MSV and assaying replicative forms of DNA by quantitative PCR. Digitaria sanguinalis, an MSV-sensitive grass species used as a model monocot, was then transformed with constructs that had inhibited virus replication in the transient-expression system. Challenge experiments using leafhopper-transmitted MSV indicated significant MSV resistance--from highly resistant to immune--in regenerated transgenic D. sanguinalis lines. Whereas regenerated lines containing a mutated full-length rep gene displayed developmental and growth defects, those containing a truncated rep gene both were fertile and displayed no growth defects, making the truncated gene a suitable candidate for the development of transgenic MSV-resistant maize.
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Affiliation(s)
- Dionne N Shepherd
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch, Cape Town 7701, South Africa
| | - Tichaona Mangwende
- Division of Pharmacology, University of Cape Town, Cape Town, South Africa
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch, Cape Town 7701, South Africa
| | - Darren P Martin
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, Anzio Road, Cape Town 7925, South Africa
| | - Marion Bezuidenhout
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch, Cape Town 7701, South Africa
| | - Jennifer A Thomson
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch, Cape Town 7701, South Africa
| | - Edward P Rybicki
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, Anzio Road, Cape Town 7925, South Africa
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch, Cape Town 7701, South Africa
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Affiliation(s)
- S E Seal
- University of Greenwich at Medway, Chatham Maritime Kent ME4 4TB, United Kingdom
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García-Arenal F, McDonald BA. An analysis of the durability of resistance to plant viruses. PHYTOPATHOLOGY 2003; 93:941-52. [PMID: 18943860 DOI: 10.1094/phyto.2003.93.8.941] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
ABSTRACT Genetic resistance often fails because a resistance-breaking (RB) pathogen genotype increases in frequency. On the basis of an analysis of cellular plant pathogens, it was recently proposed that the evolutionary potential of a pathogen is a major determinant of the durability of resistance. We test this hypothesis for plant viruses, which differ substantially from cellular pathogens in the nature, size, and expression of their genomes. Our analysis was based on 29 plant virus species that provide a good representation of the genetic and biological diversity of plant viruses. These 29 viruses were involved in 35 pathosystems, and 50 resistance factors deployed against them were analyzed. Resistance was found to be durable more often than not, in contrast with resistance to cellular plant pathogens. In a third of the analyzed pathosystems RB strains have not been reported, and in another third RB strains have been reported but have not become prevalent in the virus population. The evolutionary potential of the viruses in the 35 pathosystems was evaluated with a compound risk index based on three evolutionary factors: the population of the pathogen, the degree of recombination, and the amount of gene and genotype flow. Our analysis indicates that evolutionary potential may be an important determinant of the durability of resistance against plant viruses.
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Redinbaugh MG. Transmission of Maize streak virus by vascular puncture inoculation with unit-length genomic DNA. J Virol Methods 2003; 109:95-8. [PMID: 12668274 DOI: 10.1016/s0166-0934(03)00044-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The infectivity of cloned unit-length genomes of Maize streak virus (MSV) was tested using vascular puncture inoculation (VPI). VPI of kernels with plasmid DNA (pUC19) carrying a tandem repeat of the MSV genome produced 33+/-8% infection. Similar plasmids carrying the unit-length MSV genome were not infectious. If the MSV genome was released from the plasmid prior to VPI, 16+/-4% of plants became infected. Ligation of the free linear MSV genome did not increase infectivity. The three infective inocula produced symptoms of similar severity in maize. Bioassay of systemically infected leaves indicated the virus was equally infectious regardless of inoculum. In Southern blots of bioassay plants, no differences in MSV genome restriction endonuclease sites were observed. Thus, inoculation with the free linear or circularized MSV unit-length genome produced infections similar to those with plasmids carrying tandemly repeated genomes. The infectivity of free linear MSV unit-length genomes will facilitate molecular analysis of MSV, because cloning steps are minimized.
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Affiliation(s)
- M G Redinbaugh
- Department of Plant Pathology, Ohio Agriculture Research and Development Center, The Ohio State University, 1680 Madison Avenue, Wooster, OH 44691, USA.
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Gafni Y. Tomato yellow leaf curl virus, the intracellular dynamics of a plant DNA virus. MOLECULAR PLANT PATHOLOGY 2003; 4:9-15. [PMID: 20569358 DOI: 10.1046/j.1364-3703.2003.00147.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
UNLABELLED SUMMARY Tomato yellow leaf curl virus is a geminivirus, transmitted by whitefly (Bemisia tabaci) and causing the most destructive disease of tomato throughout the Mediterranean region, the Middle East and the tropical regions of Africa and Central America. Affected plants produce either no fruits or a few small fruits. Since it is an ssDNA virus which replicates in the host cell nucleus, the molecular mechanisms involved in the viral nuclear import have been the focus of our studies in recent years and results as well as prospects will be discussed. TAXONOMY Tomato yellow leaf curl virus (TYLCV) is a ssDNA plant virus, a member of the family Geminiviridae, of the genus Begomovirus. Physical properties: TYLCV, like all members of Geminiviridae, has geminate (twinned) particles, 18-20 nm in diameter, 30 nm long, apparently consisting of two incomplete T = 1 icosahedra joined together in a structure with 22 pentameric capsomers and 110 identical protein subunits (Fig. 1). Disease symptoms: Symptoms become visible in tomato in approximately 2-3 weeks after infection (Fig. 2). Leaf symptoms include chlorotic margins, small leaves that are cupped, thick and rubbery. The majority (up to 90%) of flowers abscise after infection, and therefore few fruits are produced. In Israel and elsewhere, weeds bridge the gap as potential perennial host and source of the virus between tomato growing seasons. Disease control: Control of TYLCV is currently based on insecticide treatments and/or physical barriers against the insect vector (Bemisia tabaci), and on tomato breeding programs based on introgression of resistance or tolerance from wild species to cultivated tomato. Useful website: <http://www.danforthcentre.org/iltab/geminiviridae/>
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Affiliation(s)
- Yedidya Gafni
- Department of Plant Genetics, A.R.O., The Volcani Center, Bet Dagan 50250, Israel
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Martin DP, Rybicki EP. Investigation of Maize streak virus pathogenicity determinants using chimaeric genomes. Virology 2002; 300:180-8. [PMID: 12350349 DOI: 10.1006/viro.2002.1458] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Genes and intergenic regions were reciprocally exchanged between a highly pathogenic Maize streak virus (MSV) isolate (MSV-MatA) and three less pathogenic isolates (MSV-Kom, MSV-R2, and MSV-VW) to determine the contribution of individual genome constituents to MSV pathogenicity in maize. Comparison of disease symptoms produced by the 54 resulting chimaeras and parental viruses enabled identification of genome constituents that are primarily responsible for the heightened pathogenicity of MSV-MatA in maize. Whereas pathogenicity determinants were detected in all of the MSV genomic regions examined, generally only chimaeras containing the MSV-MatA long intergenic region, coat protein gene, and/or movement protein gene were more pathogenic than the milder MSV isolates from which most of their genomes were derived. The pathogenicity of chimeras was strongly influenced by the relatedness of their parental viruses and evidence was found of nucleotide sequence-dependent interactions between both coding and intergenic regions.
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Affiliation(s)
- D P Martin
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch, 7701, Western Cape, South Africa
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Schnippenkoetter WH, Martin DP, Willment JA, Rybicki EP. Forced recombination between distinct strains of Maize streak virus. J Gen Virol 2001; 82:3081-3090. [PMID: 11714986 DOI: 10.1099/0022-1317-82-12-3081] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recombination between divergent virus genomes is believed to be a major mechanism for generation of novel virus genotypes. We have examined the recombination process in geminiviruses by forcing recombination between two distinct isolates of Maize streak virus (MSV), MSV-Kom and MSV-Set. Heterodimeric agroinfectious constructs containing tandemly cloned mixtures of complete or partial MSV-Set and MSV-Kom genomes were used to simulate a circular dimeric form similar to that which would be expected to occur following a single intermolecular crossing-over event between MSV-Set and MSV-Kom replicative form DNAs at the long intergenic region (LIR)-movement protein gene (MP) interface. We isolated, analysed and biologically characterized many of the recombinant MSV genomes that were generated from the constructs in planta. Apart from having the same simulated breakpoint at the LIR-MP interface, all the genomes examined had a second breakpoint that had been generated through either intramolecular homologous recombination or a replicational release mechanism. The pathogenicities of six predominantly MSV-Kom-like recombinants were tested in maize. While all were capable of producing a symptomatic infection in this host, none was more virulent than MSV-Kom and only two were more virulent than MSV-Set. The two most virulent recombinants were leafhopper transmitted to a range of differentially MSV-resistant maize, wheat and barley genotypes and both were found to have unique biological properties.
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Affiliation(s)
- W H Schnippenkoetter
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Cape Town 7000, South Africa1
| | - D P Martin
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Cape Town 7000, South Africa1
| | - J A Willment
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Cape Town 7000, South Africa1
| | - E P Rybicki
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Cape Town 7000, South Africa1
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Martin DP, Willment JA, Billharz R, Velders R, Odhiambo B, Njuguna J, James D, Rybicki EP. Sequence diversity and virulence in Zea mays of Maize streak virus isolates. Virology 2001; 288:247-55. [PMID: 11601896 DOI: 10.1006/viro.2001.1075] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Full genomic sequences were determined for 12 Maize streak virus (MSV) isolates obtained from Zea mays and wild grass species. These and 10 other publicly available full-length sequences were used to classify a total of 66 additional MSV isolates that had been characterized by PCR-restriction fragment length polymorphism and/or partial nucleotide sequence analysis. A description is given of the host and geographical distribution of the MSV strain and subtype groupings identified. The relationship between the genotypes of 21 fully sequenced virus isolates and their virulence in differentially MSV-resistant Z. mays genotypes was examined. Within the only MSV strain grouping that produced severe symptoms in maize, highly virulent and widely distributed genotypes were identified that are likely to pose the most serious threat to maize production in Africa. Evidence is presented that certain of the isolates investigated may be the products of either intra- or interspecific recombination.
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Affiliation(s)
- D P Martin
- Department of Moleculare Cell Biology, University of Cape Town, Cape Town, South Africa, 7701
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