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Mbewe W, Mukasa S, Ochwo-Ssemakula M, Sseruwagi P, Tairo F, Ndunguru J, Duffy S. Cassava brown streak virus evolves with a nucleotide-substitution rate that is typical for the family Potyviridae. Virus Res 2024; 346:199397. [PMID: 38750679 PMCID: PMC11145536 DOI: 10.1016/j.virusres.2024.199397] [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: 12/14/2023] [Revised: 05/08/2024] [Accepted: 05/12/2024] [Indexed: 05/25/2024]
Abstract
The ipomoviruses (family Potyviridae) that cause cassava brown streak disease (cassava brown streak virus [CBSV] and Uganda cassava brown streak virus [UCBSV]) are damaging plant pathogens that affect the sustainability of cassava production in East and Central Africa. However, little is known about the rate at which the viruses evolve and when they emerged in Africa - which inform how easily these viruses can host shift and resist RNAi approaches for control. We present here the rates of evolution determined from the coat protein gene (CP) of CBSV (Temporal signal in a UCBSV dataset was not sufficient for comparable analysis). Our BEAST analysis estimated the CBSV CP evolves at a mean rate of 1.43 × 10-3 nucleotide substitutions per site per year, with the most recent common ancestor of sampled CBSV isolates existing in 1944 (95% HPD, between years 1922 - 1963). We compared the published measured and estimated rates of evolution of CPs from ten families of plant viruses and showed that CBSV is an average-evolving potyvirid, but that members of Potyviridae evolve more quickly than members of Virgaviridae and the single representatives of Betaflexiviridae, Bunyaviridae, Caulimoviridae and Closteroviridae.
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Affiliation(s)
- Willard Mbewe
- Department of Biological Sciences, Malawi University of Science and Technology, P. O. Box 5196, Limbe, Malawi.
| | - Settumba Mukasa
- School of Agriculture and Environmental Science, Department of Agricultural Production, P. O. Box 7062, Makerere University, Kampala, Uganda
| | - Mildred Ochwo-Ssemakula
- School of Agriculture and Environmental Science, Department of Agricultural Production, P. O. Box 7062, Makerere University, Kampala, Uganda
| | - Peter Sseruwagi
- Mikocheni Agricultural Research Institute, P.O. Box 6226, Dar es Slaam, Tanzania
| | - Fred Tairo
- Mikocheni Agricultural Research Institute, P.O. Box 6226, Dar es Slaam, Tanzania
| | - Joseph Ndunguru
- Mikocheni Agricultural Research Institute, P.O. Box 6226, Dar es Slaam, Tanzania
| | - Siobain Duffy
- Department of Ecology, Evolution and Natural Resources, Rutgers University, New Brunswick, NJ 08901, United States.
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Rajabu CA, Dallas MM, Chiunga E, De León L, Ateka EM, Tairo F, Ndunguru J, Ascencio-Ibanez JT, Hanley-Bowdoin L. SEGS-1 a cassava genomic sequence increases the severity of African cassava mosaic virus infection in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2023; 14:1250105. [PMID: 37915512 PMCID: PMC10616593 DOI: 10.3389/fpls.2023.1250105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 10/04/2023] [Indexed: 11/03/2023]
Abstract
Cassava is a major crop in Sub-Saharan Africa, where it is grown primarily by smallholder farmers. Cassava production is constrained by Cassava mosaic disease (CMD), which is caused by a complex of cassava mosaic begomoviruses (CMBs). A previous study showed that SEGS-1 (sequences enhancing geminivirus symptoms), which occurs in the cassava genome and as episomes during viral infection, enhances CMD symptoms and breaks resistance in cassava. We report here that SEGS-1 also increases viral disease severity in Arabidopsis thaliana plants that are co-inoculated with African cassava mosaic virus (ACMV) and SEGS-1 sequences. Viral disease was also enhanced in Arabidopsis plants carrying a SEGS-1 transgene when inoculated with ACMV alone. Unlike cassava, no SEGS-1 episomal DNA was detected in the transgenic Arabidopsis plants during ACMV infection. Studies using Nicotiana tabacum suspension cells showed that co-transfection of SEGS-1 sequences with an ACMV replicon increases viral DNA accumulation in the absence of viral movement. Together, these results demonstrated that SEGS-1 can function in a heterologous host to increase disease severity. Moreover, SEGS-1 is active in a host genomic context, indicating that SEGS-1 episomes are not required for disease enhancement.
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Affiliation(s)
- Cyprian A. Rajabu
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
- Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Mary M. Dallas
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
| | - Evangelista Chiunga
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
- Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Leandro De León
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC, United States
| | - Elijah M. Ateka
- Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Fred Tairo
- Tanzania Agricultural Research Institute-Mikocheni, Dar Es Salaam, Tanzania
| | - Joseph Ndunguru
- Tanzania Agricultural Research Institute-Mikocheni, Dar Es Salaam, Tanzania
| | - Jose T. Ascencio-Ibanez
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC, United States
| | - Linda Hanley-Bowdoin
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
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Ribeiro TFL, Oliveira DJDA, da Costa JG, Gutierrez MAM, de Oliveira EJ, Ribeiro Junior KAL, Goulart HF, Riffel A, Santana AEG. Volatile Organic Compounds from Cassava Plants Confer Resistance to the Whitefly Aleurothrixus aepim (Goeldi, 1886). INSECTS 2023; 14:762. [PMID: 37754730 PMCID: PMC10531547 DOI: 10.3390/insects14090762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 07/21/2023] [Accepted: 08/01/2023] [Indexed: 09/28/2023]
Abstract
Cassava is an essential tuber crop used to produce food, feed, and beverages. Whitefly pests, including Aleurothrixus aepim (Goeldi, 1886) (Hemiptera: Aleyrodidae), significantly affect cassava-based agroecosystems. Plant odours have been described as potential pest management tools, and the cassava clone M Ecuador 72 has been used by breeders as an essential source of resistance. In this study, we analysed and compared the volatile compounds released by this resistant clone and a susceptible genotype, BRS Jari. Constitutive odours were collected from young plants and analysed using gas chromatography-mass spectrometry combined with chemometric tools. The resistant genotype released numerous compounds with previously described biological activity and substantial amounts of the monoterpene (E)-β-ocimene. Whiteflies showed non-preferential behaviour when exposed to volatiles from the resistant genotype but not the susceptible genotype. Furthermore, pure ocimene caused non-preferential behaviour in whiteflies, indicating a role for this compound in repellence. This report provides an example of the intraspecific variation in odour emissions from cassava plants alongside information on odorants that repel whiteflies; these data can be used to devise whitefly management strategies. A better understanding of the genetic variability in cassava odour constituents and emissions under field conditions may accelerate the development of more resistant cassava varieties.
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Affiliation(s)
| | | | | | - Miguel Angel Martinez Gutierrez
- Natural Product Research Laboratory (LPqRN), Campus of Engineering and Agrarian Science, Federal University of Alagoas (UFAL), Maceió 57072-900, AL, Brazil
| | | | - Karlos Antonio Lisboa Ribeiro Junior
- Institute of Chemistry and Biotechnology, Federal University of Alagoas, Maceió 57072-900, AL, Brazil
- Natural Product Research Laboratory (LPqRN), Campus of Engineering and Agrarian Science, Federal University of Alagoas (UFAL), Maceió 57072-900, AL, Brazil
| | - Henrique Fonseca Goulart
- Natural Product Research Laboratory (LPqRN), Campus of Engineering and Agrarian Science, Federal University of Alagoas (UFAL), Maceió 57072-900, AL, Brazil
| | | | - Antonio Euzebio Goulart Santana
- Natural Product Research Laboratory (LPqRN), Campus of Engineering and Agrarian Science, Federal University of Alagoas (UFAL), Maceió 57072-900, AL, Brazil
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Godding D, Stutt ROJH, Alicai T, Abidrabo P, Okao-Okuja G, Gilligan CA. Developing a predictive model for an emerging epidemic on cassava in sub-Saharan Africa. Sci Rep 2023; 13:12603. [PMID: 37537204 PMCID: PMC10400665 DOI: 10.1038/s41598-023-38819-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 07/15/2023] [Indexed: 08/05/2023] Open
Abstract
The agricultural productivity of smallholder farmers in sub-Saharan Africa (SSA) is severely constrained by pests and pathogens, impacting economic stability and food security. An epidemic of cassava brown streak disease, causing significant yield loss, is spreading rapidly from Uganda into surrounding countries. Based on sparse surveillance data, the epidemic front is reported to be as far west as central DRC, the world's highest per capita consumer, and as far south as Zambia. Future spread threatens production in West Africa including Nigeria, the world's largest producer of cassava. Using innovative methods we develop, parameterise and validate a landscape-scale, stochastic epidemic model capturing the spread of the disease throughout Uganda. The model incorporates real-world management interventions and can be readily extended to make predictions for all 32 major cassava producing countries of SSA, with relevant data, and lays the foundations for a tool capable of informing policy decisions at a national and regional scale.
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Affiliation(s)
- David Godding
- Epidemiology and Modelling Group, Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK.
| | - Richard O J H Stutt
- Epidemiology and Modelling Group, Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Titus Alicai
- National Crops Resources Research Institute, P. O. Box 7084, Kampala, Uganda
| | - Phillip Abidrabo
- National Crops Resources Research Institute, P. O. Box 7084, Kampala, Uganda
| | - Geoffrey Okao-Okuja
- National Crops Resources Research Institute, P. O. Box 7084, Kampala, Uganda
| | - Christopher A Gilligan
- Epidemiology and Modelling Group, Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
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Milenovic M, Eickermann M, Junk J, Rapisarda C. Life history parameters of Bemisia tabaci MED (Hemiptera: Aleyrodidae) in the present and future climate of central Europe, predicted by physically realistic climatic chamber simulation. ENVIRONMENTAL ENTOMOLOGY 2023; 52:502-509. [PMID: 36932855 PMCID: PMC10272707 DOI: 10.1093/ee/nvad023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 02/03/2023] [Accepted: 02/24/2023] [Indexed: 06/17/2023]
Abstract
Whiteflies of the Bemisia tabaci species complex are among the most damaging insect pests in agriculture worldwide, causing damage by feeding on crop plants and by vectoring plant viruses. The species complex consists of over 35 cryptic species that differ in many aspects of their biology including the optimal environment, geographic distribution, and host range. Global warming and associated climate change resulting from human activities is expected to contribute to biological invasions. Bemisia tabaci species show fast adaptability to changes in agroecosystems and have a long record of biological invasions. Climate change driven increase in B. tabaci importance in agricultural systems of Europe has been predicted, but so far not experimentally tested. The present study evaluates the development of B. tabaci MED (=Mediterranean) in a climatic chamber simulation of the future climate in Luxembourg, chosen as a representative region for the Central Europe. Future climate predictions for the period 2061-2070 were derived from a multimodel ensemble of physically consistent regional climatic models. Results show a 40% shorter development time of this important pest in future climatic conditions, with an increase in fecundity by a third, and insignificant difference in mortality. Accelerated development, combined with its already established year-round presence in European greenhouses and predicted northward expansion of outdoor tomato production in Europe, means faster population build-up at the beginning of the outdoor cropping season with the potential of reaching economic importance. Benefits of simulating hourly diurnal cycle of physically consistent meteorological variables versus previous experiments are discussed.
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Affiliation(s)
- Milan Milenovic
- Environmental Research and Innovation Department (ERIN), Luxembourg Institute of Science and Technology (LIST), 41, Rue du Brill, L-4422 Belvaux, Luxembourg
- Dipartimento di Agricoltura, Alimentazione e Ambiente (Di3A), Università degli Studi di Catania, Via Santa Sofia 100, 95123 Catania, Italy
| | - Michael Eickermann
- Environmental Research and Innovation Department (ERIN), Luxembourg Institute of Science and Technology (LIST), 41, Rue du Brill, L-4422 Belvaux, Luxembourg
| | - Jürgen Junk
- Environmental Research and Innovation Department (ERIN), Luxembourg Institute of Science and Technology (LIST), 41, Rue du Brill, L-4422 Belvaux, Luxembourg
| | - Carmelo Rapisarda
- Dipartimento di Agricoltura, Alimentazione e Ambiente (Di3A), Università degli Studi di Catania, Via Santa Sofia 100, 95123 Catania, Italy
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Dye AE, Muga B, Mwangi J, Hoyer JS, Ly V, Rosado Y, Sharpee W, Mware B, Wambugu M, Labadie P, Deppong D, Jackai L, Jacobson A, Kennedy G, Ateka E, Duffy S, Hanley-Bowdoin L, Carbone I, Ascencio-Ibáñez JT. Cassava begomovirus species diversity changes during plant vegetative cycles. Front Microbiol 2023; 14:1163566. [PMID: 37303798 PMCID: PMC10248227 DOI: 10.3389/fmicb.2023.1163566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 04/17/2023] [Indexed: 06/13/2023] Open
Abstract
Cassava is a root crop important for global food security and the third biggest source of calories on the African continent. Cassava production is threatened by Cassava mosaic disease (CMD), which is caused by a complex of single-stranded DNA viruses (family: Geminiviridae, genus: Begomovirus) that are transmitted by the sweet potato whitefly (Bemisia tabaci). Understanding the dynamics of different cassava mosaic begomovirus (CMB) species through time is important for contextualizing disease trends. Cassava plants with CMD symptoms were sampled in Lake Victoria and coastal regions of Kenya before transfer to a greenhouse setting and regular propagation. The field-collected and greenhouse samples were sequenced using Illumina short-read sequencing and analyzed on the Galaxy platform. In the field-collected samples, African cassava mosaic virus (ACMV), East African cassava mosaic virus (EACMV), East African cassava mosaic Kenya virus (EACMKV), and East African cassava mosaic virus-Uganda variant (EACMV-Ug) were detected in samples from the Lake Victoria region, while EACMV and East African mosaic Zanzibar virus (EACMZV) were found in the coastal region. Many of the field-collected samples had mixed infections of EACMV and another begomovirus. After 3 years of regrowth in the greenhouse, only EACMV-like viruses were detected in all samples. The results suggest that in these samples, EACMV becomes the dominant virus through vegetative propagation in a greenhouse. This differed from whitefly transmission results. Cassava plants were inoculated with ACMV and another EACMV-like virus, East African cassava mosaic Cameroon virus (EACMCV). Only ACMV was transmitted by whiteflies from these plants to recipient plants, as indicated by sequencing reads and copy number data. These results suggest that whitefly transmission and vegetative transmission lead to different outcomes for ACMV and EACMV-like viruses.
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Affiliation(s)
- Anna E. Dye
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
| | - Brenda Muga
- Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Jenniffer Mwangi
- Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - J. Steen Hoyer
- Department of Ecology, Evolution and Natural Resources, Rutgers University, New Brunswick, NJ, United States
| | - Vanessa Ly
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC, United States
| | - Yamilex Rosado
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC, United States
| | - William Sharpee
- International Livestock Research Institute (ILRI), Nairobi, Kenya
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, United States
| | - Benard Mware
- International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Mary Wambugu
- International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Paul Labadie
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, United States
| | - David Deppong
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
| | - Louis Jackai
- Department of Natural Resources and Environmental Design, North Carolina Agricultural and Technical State University, Greensboro, NC, United States
| | - Alana Jacobson
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States
| | - George Kennedy
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, United States
| | - Elijah Ateka
- Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Siobain Duffy
- Department of Ecology, Evolution and Natural Resources, Rutgers University, New Brunswick, NJ, United States
| | - Linda Hanley-Bowdoin
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
| | - Ignazio Carbone
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, United States
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In Silico Identification of Cassava Genome-Encoded MicroRNAs with Predicted Potential for Targeting the ICMV-Kerala Begomoviral Pathogen of Cassava. Viruses 2023; 15:v15020486. [PMID: 36851701 PMCID: PMC9963618 DOI: 10.3390/v15020486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/30/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023] Open
Abstract
Cassava mosaic disease (CMD) is caused by several divergent species belonging to the genus Begomovirus (Geminiviridae) transmitted by the whitefly Bemisia tabaci cryptic species group. In India and other parts of Asia, the Indian cassava mosaic virus-Kerala (ICMV-Ker) is an emergent begomovirus of cassava causing damage that results in reduced yield loss and tuber quality. Double-stranded RNA-mediated interference (RNAi) is an evolutionary conserved mechanism in eukaryotes and highly effective, innate defense system to inhibit plant viral replication and/or translation. The objective of this study was to identify and characterize cassava genome-encoded microRNAs (mes-miRNA) that are predicted to target ICMV-Ker ssDNA-encoded mRNAs, based on four in silico algorithms: miRanda, RNA22, Tapirhybrid, and psRNA. The goal is to deploy the predicted miRNAs to trigger RNAi and develop cassava plants with resistance to ICMV-Ker. Experimentally validated mature cassava miRNA sequences (n = 175) were downloaded from the miRBase biological database and aligned with the ICMV-Ker genome. The miRNAs were evaluated for base-pairing with the cassava miRNA seed regions and to complementary binding sites within target viral mRNAs. Among the 175 locus-derived mes-miRNAs evaluated, one cassava miRNA homolog, mes-miR1446a, was identified to have a predicted miRNA target binding site, at position 2053 of the ICMV-Ker genome. To predict whether the cassava miRNA might bind predicted ICMV-Ker mRNA target(s) that could disrupt viral infection of cassava plants, a cassava locus-derived miRNA-mRNA regulatory network was constructed using Circos software. The in silico-predicted cassava locus-derived mes-miRNA-mRNA network corroborated interactions between cassava mature miRNAs and the ICMV-Ker genome that warrant in vivo analysis, which could lead to the development of ICMV-Ker resistant cassava plants.
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Molecular Detection of Southern Tomato Amalgavirus Prevalent in Tomatoes and Its Genomic Characterization with Global Evolutionary Dynamics. Viruses 2022; 14:v14112481. [PMID: 36366579 PMCID: PMC9693158 DOI: 10.3390/v14112481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/04/2022] [Accepted: 11/04/2022] [Indexed: 11/11/2022] Open
Abstract
Southern tomato amalgavirus (STV) is a cryptic pathogen that is abundant in tomato production fields and intensifies the resurgence of tomato yellow stunt disease (ToYSD), together with other phytoviruses. Here, we mapped the geographical and genomic diversity, phylogenetics, and evolutionary dynamics of STV. We found that STV prevailed across China and Pakistan, with a maximum average rate of infection of 43.19% in Beijing, China, and 40.08% in Punjab, Pakistan. Subsequently, we amplified, cloned, and annotated the complete genome sequences of STV isolates from Solanum lycopersicum L. in China (OP548653 and OP548652) and Pakistan (MT066231) using Sanger and next-generation sequencing (NGS). These STV isolates displayed close evolutionary relationships with others from Asia, America, and Europe. Whole-genome-based molecular diversity analysis showed that STV populations had 33 haplotypes with a gene diversity (Hd) of 0.977 and a nucleotide diversity (π) of 0.00404. The genetic variability of RNA-dependent RNA-polymerase (RdRp) was higher than that of the putative coat protein (CP) p42. Further analysis revealed that STV isolates were likely to be recombinant but with a lower-to-moderate level of confidence. With a variable distribution pattern of positively and negatively selected sites, negative selection pressure predominantly acted on p42 and RdRp. These findings elaborated on the molecular variability and evolutionary trends among STV populations across major tomato-producing regions of the world.
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Wang Y, Shen W, Dai Z, Gou B, Liu H, Hu W, Qin L, Li Z, Tuo D, Cui H. Biological and Molecular Characterization of Two Closely Related Arepaviruses and Their Antagonistic Interaction in Nicotiana benthamiana. Front Microbiol 2021; 12:755156. [PMID: 34733264 PMCID: PMC8558625 DOI: 10.3389/fmicb.2021.755156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 09/22/2021] [Indexed: 11/25/2022] Open
Abstract
Previously, our group characterized two closely related viruses from Areca catechu, areca palm necrotic ringspot virus (ANRSV) and areca palm necrotic spindle-spot virus (ANSSV). These two viruses share a distinct genomic organization of leader proteases and represent the only two species of the newly established genus Arepavirus of the family Potyviridae. The biological features of the two viruses are largely unknown. In this study, we investigated the pathological properties, functional compatibility of viral elements, and interspecies interactions in the model plant, Nicotiana benthamiana. Using a newly obtained infectious clone of ANRSV, we showed that this virus induces more severe symptoms compared with ANSSV and that this is related to a rapid virus multiplication in planta. A series of hybrid viruses were constructed via the substitution of multiple elements in the ANRSV infectious clone with the counterparts of ANSSV. The replacement of either 5′-UTR-HCPro1–HCPro2 or CI effectively supported replication and systemic infection of ANRSV, whereas individual substitution of P3-7K, 9K-NIa, and NIb-CP-3′-UTR abolished viral infectivity. Finally, we demonstrated that ANRSV confers effective exclusion of ANSSV both in coinfection and super-infection assays. These results advance our understanding of fundamental aspects of these two distinct but closely related arepaviruses.
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Affiliation(s)
- Yaodi Wang
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Wentao Shen
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Zhaoji Dai
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Bei Gou
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Hongjun Liu
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Weiyao Hu
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Li Qin
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Zengping Li
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Decai Tuo
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Hongguang Cui
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
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Szyniszewska AM, Chikoti PC, Tembo M, Mulenga R, Gilligan CA, van den Bosch F, McQuaid CF. Smallholder Cassava Planting Material Movement and Grower Behavior in Zambia: Implications for the Management of Cassava Virus Diseases. PHYTOPATHOLOGY 2021; 111:1952-1962. [PMID: 33856231 DOI: 10.1094/phyto-06-20-0215-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Cassava (Manihot esculenta) is an important food crop across sub-Saharan Africa, where production is severely inhibited by two viral diseases, cassava mosaic disease (CMD) and cassava brown streak disease (CBSD), both propagated by a whitefly vector and via human-mediated movement of infected cassava stems. There is limited information on growers' behavior related to movement of planting material, as well as growers' perception and awareness of cassava diseases, despite the importance of these factors for disease control. This study surveyed a total of 96 cassava subsistence growers and their fields across five provinces in Zambia between 2015 and 2017 to address these knowledge gaps. CMD symptoms were observed in 81.6% of the fields, with an average incidence of 52% across the infected fields. No CBSD symptoms were observed. Most growers used planting materials from their own (94%) or nearby (<10 km) fields of family and friends, although several large transactions over longer distances (10 to 350 km) occurred with friends (15 transactions), markets (1), middlemen (5), and nongovernmental organizations (6). Information related to cassava diseases and certified clean (disease-free) seed reached only 48% of growers. The most frequent sources of information related to cassava diseases included nearby friends, family, and neighbors, while extension workers were the most highly preferred source of information. These data provide a benchmark on which to plan management approaches to controlling CMD and CBSD, which should include clean propagation material, increasing growers' awareness of the diseases, and increasing information provided to farmers (specifically disease symptom recognition and disease management options).[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
| | - Patrick Chiza Chikoti
- Zambia Agriculture Research Institute, Plant Protection and Quarantine Division, Mt. Makulu Research Station, Chilanga, Zambia
| | - Mathias Tembo
- Zambia Agriculture Research Institute, Plant Protection and Quarantine Division, Mt. Makulu Research Station, Chilanga, Zambia
| | - Rabson Mulenga
- Zambia Agriculture Research Institute, Plant Protection and Quarantine Division, Mt. Makulu Research Station, Chilanga, Zambia
| | | | - Frank van den Bosch
- Department of Environment & Agriculture, Centre for Crop and Disease Management, Curtin University, Bentley, Perth, WA 6102, Australia
| | - Christopher Finn McQuaid
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, WC1E 7HT London, United Kingdom
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Ramulifho E, Rey MEC. Proteome Mapping of South African Cassava Mosaic Virus-Infected Susceptible and Tolerant Landraces of Cassava. Proteomes 2021; 9:41. [PMID: 34842800 PMCID: PMC8628908 DOI: 10.3390/proteomes9040041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 11/25/2022] Open
Abstract
The production of cassava is threatened by the geminivirus South African cassava mosaic virus (SACMV), which causes cassava mosaic disease. Cassava landrace TME3 shows tolerance to SACMV, while T200 is highly susceptible. This study aimed to identify the leaf proteome involved in anti-viral defence. Liquid chromatography mass spectrometry (LC-MS) identified 2682 (54 differentially expressed) and 2817 (206 differentially expressed) proteins in both landraces at systemic infection (32 days post infection) and symptom recovery (67 days post infection), respectively. Differences in the number of differentially expressed proteins (DEPs) between the two landraces were observed. Gene ontology analysis showed that defence-associated pathways such as the chloroplast, proteasome, and ribosome were overrepresented at 67 days post infection (dpi) in SACMV-tolerant TME3. At 67 dpi, a high percentage (56%) of over-expressed proteins were localized in the chloroplast in TME3 compared to T200 (31% under-expressed), proposing that chloroplast proteins play a role in tolerance in TME3. Ribosomal_L7Ae domain-containing protein (Manes.12G139100) was over-expressed uniquely in TME3 at 67 dpi and interacts with the ribosomal protein Sac52 (RPL10). RPL10 is a known key player in the NIK1-mediated effector triggered immunity (ETI) response to geminivirus infection, indicating a possible role for Sac52 in SACMV recovery in TME3. In conclusion, differential protein expression responses in TME3 and T200 may be key to unravel tolerance to CMD.
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Affiliation(s)
- Elelwani Ramulifho
- Plant Biotechnology Laboratory, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2001, South Africa;
- Germplasm Development, Agricultural Research Council-Small Grain Institute, Bethlehem 9700, South Africa
| | - Marie Emma Christine Rey
- Plant Biotechnology Laboratory, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2001, South Africa;
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12
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Crespo-Bellido A, Hoyer JS, Dubey D, Jeannot RB, Duffy S. Interspecies Recombination Has Driven the Macroevolution of Cassava Mosaic Begomoviruses. J Virol 2021; 95:e0054121. [PMID: 34106000 PMCID: PMC8354330 DOI: 10.1128/jvi.00541-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 06/01/2021] [Indexed: 11/20/2022] Open
Abstract
Begomoviruses (family Geminiviridae, genus Begomovirus) significantly hamper crop production and threaten food security around the world. The frequent emergence of new begomovirus genotypes is facilitated by high mutation frequencies and the propensity to recombine and reassort. Homologous recombination has been especially implicated in the emergence of novel cassava mosaic begomovirus (CMB) genotypes, which cause cassava mosaic disease (CMD). Cassava (Manihot esculenta) is a staple food crop throughout Africa and an important industrial crop in Asia, two continents where production is severely constrained by CMD. The CMD species complex is comprised of 11 bipartite begomovirus species with ample distribution throughout Africa and the Indian subcontinent. While recombination is regarded as a frequent occurrence for CMBs, a revised, systematic assessment of recombination and its impact on CMB phylogeny is currently lacking. We assembled data sets of all publicly available, full-length DNA-A (n = 880) and DNA-B (n = 369) nucleotide sequences from the 11 recognized CMB species. Phylogenetic networks and complementary recombination detection methods revealed extensive recombination among the CMB sequences. Six out of the 11 species descended from unique interspecies recombination events. Estimates of recombination and mutation rates revealed that all species experience mutation more frequently than recombination, but measures of population divergence indicate that recombination is largely responsible for the genetic differences between species. Our results support that recombination has significantly impacted the CMB phylogeny and has driven speciation in the CMD species complex. IMPORTANCE Cassava mosaic disease (CMD) is a significant threat to cassava production throughout Africa and Asia. CMD is caused by a complex comprised of 11 recognized virus species exhibiting accelerated rates of evolution, driven by high frequencies of mutation and genetic exchange. Here, we present a systematic analysis of the contribution of genetic exchange to cassava mosaic virus species-level diversity. Most of these species emerged as a result of genetic exchange. This is the first study to report the significant impact of genetic exchange on speciation in a group of viruses.
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Affiliation(s)
- Alvin Crespo-Bellido
- Department of Ecology, Evolution and Natural Resources, School of Environmental and Biological Sciences, Rutgers State University of New Jersey, New Brunswick, New Jersey, USA
| | - J. Steen Hoyer
- Department of Ecology, Evolution and Natural Resources, School of Environmental and Biological Sciences, Rutgers State University of New Jersey, New Brunswick, New Jersey, USA
| | - Divya Dubey
- Department of Ecology, Evolution and Natural Resources, School of Environmental and Biological Sciences, Rutgers State University of New Jersey, New Brunswick, New Jersey, USA
| | - Ronica B. Jeannot
- Department of Ecology, Evolution and Natural Resources, School of Environmental and Biological Sciences, Rutgers State University of New Jersey, New Brunswick, New Jersey, USA
| | - Siobain Duffy
- Department of Ecology, Evolution and Natural Resources, School of Environmental and Biological Sciences, Rutgers State University of New Jersey, New Brunswick, New Jersey, USA
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13
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Xavier CAD, Nogueira AM, Bello VH, Watanabe LFM, Barbosa TMC, Alves Júnior M, Barbosa L, Beserra-Júnior JEA, Boari A, Calegario R, Gorayeb ES, Honorato Júnior J, Koch G, Lima GSDA, Lopes C, de Mello RN, Pantoja K, Silva FN, Ramos Sobrinho R, Santana EN, da Silva JWP, Krause-Sakate R, Zerbini FM. Assessing the diversity of whiteflies infesting cassava in Brazil. PeerJ 2021; 9:e11741. [PMID: 34316398 PMCID: PMC8286705 DOI: 10.7717/peerj.11741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 06/17/2021] [Indexed: 11/20/2022] Open
Abstract
Background The necessity of a competent vector for transmission is a primary ecological factor driving the host range expansion of plant arthropod-borne viruses, with vectors playing an essential role in disease emergence. Cassava begomoviruses severely constrain cassava production in Africa. Curiously, begomoviruses have never been reported in cassava in South America, the center of origin for this crop. It has been hypothesized that the absence of a competent vector in cassava is the reason why begomoviruses have not emerged in South America. Methods We performed a country-wide whitefly diversity study in cassava in Brazil. Adults and/or nymphs of whiteflies were collected from sixty-six cassava fields in the main agroecological zones of the country. A total of 1,385 individuals were genotyped based on mitochondrial cytochrome oxidase I sequences. Results A high species richness was observed, with five previously described species and two putative new ones. The prevalent species were Tetraleurodes acaciae and Bemisia tuberculata, representing over 75% of the analyzed individuals. Although we detected, for the first time, the presence of Bemisia tabaci Middle East-Asia Minor 1 (BtMEAM1) colonizing cassava in Brazil, it was not prevalent. The species composition varied across regions, with fields in the Northeast region showing a higher diversity. These results expand our knowledge of whitefly diversity in cassava and support the hypothesis that begomovirus epidemics have not occurred in cassava in Brazil due to the absence of competent vector populations. However, they indicate an ongoing adaptation process of BtMEAM1 to cassava, increasing the likelihood of begomovirus emergence in this crop.
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Affiliation(s)
- Cesar A D Xavier
- Dep. de Fitopatologia/BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | | | | | | | | | - Miguel Alves Júnior
- Faculdade de Engenharia Agronômica, Universidade Federal do Pará, Altamira, PA, Brazil
| | - Leonardo Barbosa
- Instituto Federal do Sudeste de Minas Gerais, Rio Pomba, MG, Brazil
| | | | | | - Renata Calegario
- Dep. de Fitotecnia e Fitossanidade, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Eduardo Silva Gorayeb
- Centro de Ciências Agroveterinárias, Universidade do Estado de Santa Catarina, Lages, SC, Brazil
| | - Jaime Honorato Júnior
- Centro Multidisciplinar do Campus de Barra, Universidade Federal do Oeste da Bahia, Barra, BA, Brazil
| | - Gabriel Koch
- Dep. de Fitotecnia e Fitossanidade, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | | | - Cristian Lopes
- Instituto Federal do Sudeste de Minas Gerais, Rio Pomba, MG, Brazil
| | | | | | - Fábio Nascimento Silva
- Centro de Ciências Agroveterinárias, Universidade do Estado de Santa Catarina, Lages, SC, Brazil
| | - Roberto Ramos Sobrinho
- Centro de Ciências Agrárias/Fitossanidade, Universidade Federal de Alagoas, Rio Largo, AL, Brazil
| | | | | | | | - Francisco M Zerbini
- Dep. de Fitopatologia/BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG, Brazil
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14
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Easson MLAE, Malka O, Paetz C, Hojná A, Reichelt M, Stein B, van Brunschot S, Feldmesser E, Campbell L, Colvin J, Winter S, Morin S, Gershenzon J, Vassão DG. Activation and detoxification of cassava cyanogenic glucosides by the whitefly Bemisia tabaci. Sci Rep 2021; 11:13244. [PMID: 34168179 PMCID: PMC8225905 DOI: 10.1038/s41598-021-92553-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 06/10/2021] [Indexed: 11/19/2022] Open
Abstract
Two-component plant defenses such as cyanogenic glucosides are produced by many plant species, but phloem-feeding herbivores have long been thought not to activate these defenses due to their mode of feeding, which causes only minimal tissue damage. Here, however, we report that cyanogenic glycoside defenses from cassava (Manihot esculenta), a major staple crop in Africa, are activated during feeding by a pest insect, the whitefly Bemisia tabaci, and the resulting hydrogen cyanide is detoxified by conversion to beta-cyanoalanine. Additionally, B. tabaci was found to utilize two metabolic mechanisms to detoxify cyanogenic glucosides by conversion to non-activatable derivatives. First, the cyanogenic glycoside linamarin was glucosylated 1–4 times in succession in a reaction catalyzed by two B. tabaci glycoside hydrolase family 13 enzymes in vitro utilizing sucrose as a co-substrate. Second, both linamarin and the glucosylated linamarin derivatives were phosphorylated. Both phosphorylation and glucosidation of linamarin render this plant pro-toxin inert to the activating plant enzyme linamarase, and thus these metabolic transformations can be considered pre-emptive detoxification strategies to avoid cyanogenesis.
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Affiliation(s)
| | - Osnat Malka
- The Hebrew University of Jerusalem, 7610001, Rehovot, Israel.
| | - Christian Paetz
- Max Planck Institute for Chemical Ecology, 07745, Jena, Germany
| | - Anna Hojná
- Max Planck Institute for Chemical Ecology, 07745, Jena, Germany
| | | | - Beate Stein
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, 38104, Braunschweig, Germany
| | - Sharon van Brunschot
- Natural Resources Institute, University of Greenwich, Chatham Maritime, ME4 4TB, Kent, UK.,University of Queensland, Brisbane, QLD, 4072, Australia
| | | | - Lahcen Campbell
- EMBL-European Bioinformatics Institute, Cambridge, CB10 1SD, UK
| | - John Colvin
- Natural Resources Institute, University of Greenwich, Chatham Maritime, ME4 4TB, Kent, UK
| | - Stephan Winter
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, 38104, Braunschweig, Germany
| | - Shai Morin
- The Hebrew University of Jerusalem, 7610001, Rehovot, Israel
| | | | - Daniel G Vassão
- Max Planck Institute for Chemical Ecology, 07745, Jena, Germany.
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15
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Ban F, Zhong Y, Pan L, Mao L, Wang X, Liu Y. Coinfection by Two Begomoviruses Aggravates Plant Symptoms But Does Not Influence the Performance and Preference of Insect Vector Bemisia tabaci (Hemiptera: Aleyrodidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2021; 114:547-554. [PMID: 33503240 DOI: 10.1093/jee/toaa326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Indexed: 06/12/2023]
Abstract
In nature, a plant can be infected by multiple viruses simultaneously. However, the effects of coinfection on plant-vector interactions are less well studied. Two begomoviruses of the family Geminiviridae, Tomato yellow leaf curl virus (TYLCV) and Tomato yellow leaf curl China virus (TYLCCNV), occur sympatrically in China. Each of them is reported to increase the performance of whitefly vector via manipulation of plant traits. In this study, we examined the effects of coinfection by the two viruses TYLCV and TYLCCNV on plant-whitefly interactions, compared to that infected by a single virus. We found that plants infected by two viruses showed aggravated symptoms but the performance and preference of whiteflies were not altered significantly compared to singly-infected plants. Coinfection suppressed the transcription of genes involved in jasmonic acid (JA) signaling pathway in plants, but showed no significant difference to single-virus infected plants. These findings suggest that although TYLCV and TYLCCNV may synergistically induce plant symptoms, they did not manipulate synergistically plant-mediated responses to the insect vector.
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Affiliation(s)
- Feixue Ban
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogen and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Yuwei Zhong
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogen and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Lilong Pan
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogen and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Lijuan Mao
- Analysis Center of Agrobiology and Environmental Sciences, Faculty of Agriculture, Life and Environment Sciences (ACAES), Zhejiang University, Hangzhou, China
| | - Xiaowei Wang
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogen and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Yinquan Liu
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogen and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
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16
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Sharma V, Lefeuvre P, Roumagnac P, Filloux D, Teycheney PY, Martin DP, Maumus F. Large-scale survey reveals pervasiveness and potential function of endogenous geminiviral sequences in plants. Virus Evol 2020; 6:veaa071. [PMID: 33391820 PMCID: PMC7758297 DOI: 10.1093/ve/veaa071] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The family Geminiviridae contains viruses with single-stranded DNA genomes that have been found infecting a wide variety of angiosperm species. The discovery within the last 25 years of endogenous geminivirus-like (EGV) elements within the nuclear genomes of several angiosperms has raised questions relating to the pervasiveness of EGVs and their impacts on host biology. Only a few EGVs have currently been characterized and it remains unclear whether any of these have influenced, or are currently influencing, the evolutionary fitness of their hosts. We therefore undertook a large-scale search for evidence of EGVs within 134 genome and 797 transcriptome sequences of green plant species. We detected homologues of geminivirus replication-associated protein (Rep) genes in forty-two angiosperm species, including two monocots, thirty-nine dicots, and one ANITA-grade basal angiosperm species (Amborella trichopoda). While EGVs were present in the members of many different plant orders, they were particularly common within the large and diverse order, Ericales, with the highest copy numbers of EGVs being found in two varieties of tea plant (Camellia sinensis). Phylogenetic and clustering analyses revealed multiple highly divergent previously unknown geminivirus Rep lineages, two of which occur in C.sinensis alone. We find that some of the Camellia EGVs are likely transcriptionally active, sometimes co-transcribed with the same host genes across several Camellia species. Overall, our analyses expand the known breadths of both geminivirus diversity and geminivirus host ranges, and strengthens support for the hypothesis that EGVs impact the biology of their hosts.
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Affiliation(s)
- Vikas Sharma
- URGI, INRAE, Université Paris-Saclay, Plant Breeding Division, 78026, Versailles, France.,Forschungszentrum Jülich GmbH, Institute for Bio- and Geosciences 1, IBG1, 52425 Jülich, Germany
| | - Pierre Lefeuvre
- CIRAD, UMR PVBMT, Department of Biological Systems, F-97410 St Pierre, La Réunion, France
| | - Philippe Roumagnac
- CIRAD, BGPI, Department of Biological Systems, 34398 Montpellier CEDEX 5, France.,BGPI, INRAE, CIRAD, Institut Agro, Univ Montpellier, Department of Biological Systems, 34398 Montpellier CEDEX 5, France
| | - Denis Filloux
- CIRAD, BGPI, Department of Biological Systems, 34398 Montpellier CEDEX 5, France.,BGPI, INRAE, CIRAD, Institut Agro, Univ Montpellier, Department of Biological Systems, 34398 Montpellier CEDEX 5, France
| | - Pierre-Yves Teycheney
- CIRAD, UMR AGAP, Department of Biological Systems, F-97130, Capesterre Belle-Eau, Guadeloupe, France.,AGAP, Univ Montpellier, CIRAD, INRAE, Institut Agro, Department of Biological Systems, F-97130 Capesterre Belle-Eau, Guadeloupe, France
| | - Darren P Martin
- Division of Computational Biology, Department of Integrative Biomedical Sciences, Institute of infectious Diseases and molecular Medicine, University of Cape Town, OBSERVATORY 7925 Cape Town, South Africa
| | - Florian Maumus
- URGI, INRAE, Université Paris-Saclay, Plant Breeding Division, 78026, Versailles, France
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17
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Donnelly R, Sikazwe GW, Gilligan CA. Estimating epidemiological parameters from experiments in vector access to host plants, the method of matching gradients. PLoS Comput Biol 2020; 16:e1007724. [PMID: 32176681 PMCID: PMC7098647 DOI: 10.1371/journal.pcbi.1007724] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 03/26/2020] [Accepted: 02/12/2020] [Indexed: 11/18/2022] Open
Abstract
Estimation of pathogenic life-history values, for instance the duration a pathogen is retained in an insect vector (i.e., retention period) is of particular importance for understanding plant disease epidemiology. How can we extract values for these epidemiological parameters from conventional small-scale laboratory experiments in which transmission success is measured in relation to durations of vector access to host plants? We provide a solution to this problem by deriving formulae for the empirical curves that these experiments produce, called access period response curves (i.e., transmission success vs access period). We do this by writing simple equations for the fundamental life-cycle components of insect vectors in the laboratory. We then infer values of epidemiological parameters by matching the theoretical and empirical gradients of access period response curves. Using the example of Cassava brown streak virus (CBSV), which has emerged in sub-Saharan Africa and now threatens regional food security, we illustrate the method of matching gradients. We show how applying the method to published data produces a new understanding of CBSV through the inference of retention period, acquisition period and inoculation period parameters. We found that CBSV is retained for a far shorter duration in its insect vector (Bemisia tabaci whitefly) than had previously been assumed. Our results shed light on a number of critical factors that may be responsible for the transition of CBSV from sub- to super-threshold R0 in sub-Saharan Africa. The method is applicable to plant pathogens in general, to supply epidemiological parameter estimates that are crucial for practical management of epidemics and prediction of pandemic risk. Cassava brown streak virus (CBSV), which was confined to coastal East Africa and the shores of Lake Malawi, has rapidly expanded its geographic range and now threatens regional food security. A recent laboratory experiment, in which vector access to plants infected with CBSV is varied, has provided plausible ranges for epidemiological parameters such as pathogen retention period (i.e., the duration that the pathogen is retained by the vector). In this work we introduce a new computational and mathematical framework for estimating epidemiological parameter values, instead of plausible ranges, from experiments in vector access to host plants. Since long distance carriage of insect vectors occurs within atmospheric air flows, the duration that the vector retains the pathogen (i.e., retention period) indirectly limits the scale of epidemics. Using our methods, we found that CBSV is retained for a far shorter duration than had previously been assumed. Our methods can be applied to the many experiments in vector access to host plants that have been conducted for numerous arthropod-transmitted plant pathogens across a range of genera. The ensuing epidemiological parameter estimates can be used in landscape computer simulations to predict epidemic risk and the prospects for control.
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Affiliation(s)
- Ruairí Donnelly
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
| | - Geofrey W. Sikazwe
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
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18
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Li P, Jing C, Ren H, Jia Z, Ghanem H, Wu G, Li M, Qing L. Analysis of Pathogenicity and Virulence Factors of Ageratum leaf curl Sichuan virus. FRONTIERS IN PLANT SCIENCE 2020; 11:527787. [PMID: 33042171 PMCID: PMC7527423 DOI: 10.3389/fpls.2020.527787] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 08/28/2020] [Indexed: 05/05/2023]
Abstract
Ageratum leaf curl Sichuan virus (ALCScV) is a novel monopartite begomovirus, which was identified from Ageratum conyzoides plants in Sichuan Province, China. In this study, we showed that ALCScV can induce typical dwarf and downward leaf-curling symptoms in Ageratum conyzoides, Helianthus annuus, and Nicotiana benthamiana plants and that the noncognate betasatellite can enhance disease symptoms and increase viral accumulation. Expression of the ALCScV-encoded V2, C1, and C4 proteins through a Potato virus X (PVX) vector caused severe symptoms in N. benthamiana. Further study revealed no symptoms in N. benthamiana plants inoculated with infectious ALCScV clones lacking the C4 protein and that the relative viral DNA accumulation levels significantly decreased when compared with ALCScV-inoculated plants. Thus, our mutational analyses demonstrated that C4 is a pathogenicity determinant that plays key roles in symptom formation and virus accumulation. Furthermore, we also demonstrated that the second glycine of C4 was critical for ALCScV pathogenicity.
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19
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Abstract
The pathological importance of mixed viral infections in plants might be underestimated except for a few well-characterized synergistic combinations in certain crops. Considering that the host ranges of many viruses often overlap and that most plant species can be infected by several unrelated viruses, it is not surprising to find more than one virus simultaneously in the same plant. Furthermore, dispersal of the majority of plant viruses relies on efficient transmission mechanisms mediated by vector organisms, mainly but not exclusively insects, which can contribute to the occurrence of multiple infections in the same plant. Recent work using different experimental approaches has shown that mixed viral infections can be remarkably frequent, up to the point that they could be considered the rule more than the exception. The purpose of this review is to describe the impact of multiple infections not only on the participating viruses themselves but also on their vectors and on the common host. From this standpoint, mixed infections arise as complex events that involve several cross-interacting players, and they consequently require a more general perspective than the analysis of single-virus/single-host approaches for a full understanding of their relevance.
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Affiliation(s)
- Ana Beatriz Moreno
- Centre for Research in Agricultural Genomics, Consejo Superior de Investigaciones Científicas IRTA-UAB-UB, Cerdanyola del Vallès, Barcelona, Spain
| | - Juan José López-Moya
- Centre for Research in Agricultural Genomics, Consejo Superior de Investigaciones Científicas IRTA-UAB-UB, Cerdanyola del Vallès, Barcelona, Spain
- Consejo Superior de Investigaciones Científicas, Barcelona, Spain
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20
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Ally HM, Hamss HE, Simiand C, Maruthi MN, Colvin J, Omongo CA, Delatte H. What has changed in the outbreaking populations of the severe crop pest whitefly species in cassava in two decades? Sci Rep 2019; 9:14796. [PMID: 31615997 PMCID: PMC6794263 DOI: 10.1038/s41598-019-50259-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 08/19/2019] [Indexed: 12/04/2022] Open
Abstract
High populations of African cassava whitefly (Bemisia tabaci) have been associated with epidemics of two viral diseases in Eastern Africa. We investigated population dynamics and genetic patterns by comparing whiteflies collected on cassava in 1997, during the first whitefly upsurges in Uganda, with collections made in 2017 from the same locations. Nuclear markers and mtCOI barcoding sequences were used on 662 samples. The composition of the SSA1 population changed significantly over the 20-year period with the SSA1-SG2 percentage increasing from 0.9 to 48.6%. SSA1-SG1 and SSA1-SG2 clearly interbreed, confirming that they are a single biological species called SSA1. The whitefly species composition changed: in 1997, SSA1, SSA2 and B. afer were present; in 2017, no SSA2 was found. These data and those of other publications do not support the 'invader' hypothesis. Our evidence shows that no new species or new population were found in 20 years, instead, the distribution of already present genetic clusters composing SSA1 species have changed over time and that this may be in response to several factors including the introduction of new cassava varieties or climate changes. The practical implications are that cassava genotypes possessing both whitefly and disease resistances are needed urgently.
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Affiliation(s)
- Hadija M Ally
- Université de La Réunion, 97715, 15 Avenue René Cassin, Sainte-Clotilde, La Reunion, France
- CIRAD, UMR PVBMT, 7 Chemin de l'Irat, Ligne Paradis, 97410, Saint Pierre, La Reunion, France
- Tanzania Agricultural Research Institute-Ukiriguru, P.O. Box, 1433, Mwanza, Tanzania
| | - Hajar El Hamss
- Natural Resources Institute (NRI), University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
| | - Christophe Simiand
- CIRAD, UMR PVBMT, 7 Chemin de l'Irat, Ligne Paradis, 97410, Saint Pierre, La Reunion, France
| | - M N Maruthi
- Natural Resources Institute (NRI), University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
| | - John Colvin
- Natural Resources Institute (NRI), University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
| | - Christopher A Omongo
- Root Crops Programme, National Crops Resource Research Institute (RCP-NaCRRI), P.O. Box, 7084, Kampala, Uganda
| | - Helene Delatte
- CIRAD, UMR PVBMT, 7 Chemin de l'Irat, Ligne Paradis, 97410, Saint Pierre, La Reunion, France.
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21
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Abstract
Viral diseases provide a major challenge to twenty-first century agriculture worldwide. Climate change and human population pressures are driving rapid alterations in agricultural practices and cropping systems that favor destructive viral disease outbreaks. Such outbreaks are strikingly apparent in subsistence agriculture in food-insecure regions. Agricultural globalization and international trade are spreading viruses and their vectors to new geographical regions with unexpected consequences for food production and natural ecosystems. Due to the varying epidemiological characteristics of diverent viral pathosystems, there is no one-size-fits-all approach toward mitigating negative viral disease impacts on diverse agroecological production systems. Advances in scientific understanding of virus pathosystems, rapid technological innovation, innovative communication strategies, and global scientific networks provide opportunities to build epidemiologic intelligence of virus threats to crop production and global food security. A paradigm shift toward deploying integrated, smart, and eco-friendly strategies is required to advance virus disease management in diverse agricultural cropping systems.
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Affiliation(s)
- Roger A C Jones
- Institute of Agriculture, University of Western Australia, Crawley, Western Australia 6009, Australia; .,Department of Primary Industries and Regional Development, South Perth, Western Australia 6151, Australia
| | - Rayapati A Naidu
- Department of Plant Pathology, Irrigated Agriculture Research and Extension Center, Washington State University, Prosser, Washington 99350, USA;
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22
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García-Arenal F, Zerbini FM. Life on the Edge: Geminiviruses at the Interface Between Crops and Wild Plant Hosts. Annu Rev Virol 2019; 6:411-433. [PMID: 31180812 DOI: 10.1146/annurev-virology-092818-015536] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Viruses constitute the largest group of emerging pathogens, and geminiviruses (plant viruses with circular, single-stranded DNA genomes) are the major group of emerging plant viruses. With their high potential for genetic variation due to mutation and recombination, their efficient spread by vectors, and their wide host range as a group, including both wild and cultivated hosts, geminiviruses are attractive models for the study of the evolutionary and ecological factors driving virus emergence. Studies on the epidemiological features of geminivirus diseases have traditionally focused primarily on crop plants. Nevertheless, knowledge of geminivirus infection in wild plants, and especially at the interface between wild and cultivated plants, is necessary to provide a complete view of their ecology, evolution, and emergence. In this review, we address the most relevant aspects of geminivirus variability and evolution in wild and crop plants and geminiviruses' potential to emerge in crops.
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Affiliation(s)
- Fernando García-Arenal
- Centro de Biotecnología y Genómica de Plantas UPM-INIA and Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, 28223 Pozuelo de Alarcón, Madrid, Spain;
| | - Francisco Murilo Zerbini
- Departamento de Fitopatologia, Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), and National Research Institute for Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil;
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23
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Luo C, Wang ZQ, Liu X, Zhao L, Zhou X, Xie Y. Identification and Analysis of Potential Genes Regulated by an Alphasatellite (TYLCCNA) that Contribute to Host Resistance against Tomato Yellow Leaf Curl China Virus and Its Betasatellite (TYLCCNV/TYLCCNB) Infection in Nicotiana benthamiana. Viruses 2019; 11:E442. [PMID: 31096636 PMCID: PMC6563268 DOI: 10.3390/v11050442] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 05/12/2019] [Accepted: 05/14/2019] [Indexed: 01/13/2023] Open
Abstract
Recently, begomovirus/betasatellite disease complexes were found to be associated with alphasatellites, and their presence modulated disease symptoms and/or viral DNA accumulation in infected plants. However, the biological functions of alphasatellites during begomovirus/betasatellite infections remain unclear. Tomato yellow leaf curl China virus (TYLCCNV) associated with a betasatellite (TYLCCNB) is a widespread monopartite begomovirus in China. In the Yunnan province of China, the TYLCCNV/TYLCCNB disease complex is found in association with an alphasatellite (TYLCCNA). In this study, in order to explain the mechanisms underlying TYLCCNV/TYLCCNB infection and reductions in viral DNA accumulation caused by TYLCCNA, we analyzed the transcriptome profiles of Nicotiana benthamiana seedlings challenged by TYLCCNV/TYLCCNB or TYLCCNV/TYLCCNB/TYLCCNA using RNA sequencing. In total, 2272 and 1207 differentially expressed genes (DEGs) were identified to respond to TYLCCNV/TYLCCNB and TYLCCNV/TYLCCNB/TYLCCNA infections, respectively. Compared with the DEGs in the TYLCCNV/TYLCCNB-infected N. benthamiana seedlings, the number of DEGs in plants co-infected with TYLCCNV/TYLCCNB + TYLCCNA was significantly reduced. Additionally, 36 DEGs were identified to be regulated by TYLCCNA, six of which were further analyzed using the virus-induced gene silencing (VIGS) approach. Silencing of these six TYLCCNA responsive DEGs caused more severe disease symptoms and higher viral DNA accumulation levels, suggesting that TYLCCNA responsive DEGs may attenuate TYLCCNV/TYLCCNB infection.
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Affiliation(s)
- Chaohu Luo
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
| | - Zhan Qi Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China.
| | - Xianan Liu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
| | - Liling Zhao
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
- Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Yan Xie
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
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24
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Inner Workings: Portable DNA sequencer helps farmers stymie devastating viruses. Proc Natl Acad Sci U S A 2019; 116:3351-3353. [PMID: 30808731 DOI: 10.1073/pnas.1901806116] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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