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Dalaisón-Fuentes LI, Pascual A, Gazza E, Welchen E, Rivera-Pomar R, Catalano MI. Development of efficient RNAi methods in the corn leafhopper Dalbulus maidis, a promising application for pest control. PEST MANAGEMENT SCIENCE 2022; 78:3108-3116. [PMID: 35442515 DOI: 10.1002/ps.6937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 04/13/2022] [Accepted: 04/20/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND The corn leafhopper Dalbulus maidis is the main vector of important stunting pathogens that affect maize production. Currently, there are no effective methods available to manage this pest without adverse impact on the environment. In this context, genomic-based technologies such as RNA interference (RNAi) provide a more environmentally friendly pest control strategy. Therefore, we aimed to assess the application of RNAi in D. maidis and determine the function of a candidate gene related to insect reproduction and propagation. RESULTS We have characterized the core RNAi genes and evaluated the functionality of the RNAi machinery. We assessed the potential of RNAi technology in D. maidis via injection or ingestion of double-stranded RNA (dsRNA) to adult females. We chose Bicaudal C (BicC) as a target gene due to its important role during insect oogenesis. Administration of dsRNABicC caused significant reductions in the transcript levels (fold changes up to 170 times) and ovipositions. Phenotypic analysis of the ovaries revealed alterations in oocyte development, providing additional confirmation for our results and supporting the idea that Dmai-BicC is a key player of D. maidis oogenesis. CONCLUSION This is, to our knowledge, the first report of efficient RNAi in D. maidis. We believe our findings provide a starting point for future control strategies against one of the most important maize pests in the Americas. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Lucía Inés Dalaisón-Fuentes
- Centro de BioInvestigaciones (Universidad Nacional del Noroeste de la Provincia de Buenos Aires-CICBA), Pergamino, Argentina
- Centro de Investigaciones y Transferencias del Noroeste de la provincia de Buenos Aires (CITNOBA-CONICET), Pergamino, Argentina
| | - Agustina Pascual
- Centro de BioInvestigaciones (Universidad Nacional del Noroeste de la Provincia de Buenos Aires-CICBA), Pergamino, Argentina
- Centro de Investigaciones y Transferencias del Noroeste de la provincia de Buenos Aires (CITNOBA-CONICET), Pergamino, Argentina
| | - Elías Gazza
- Centro de BioInvestigaciones (Universidad Nacional del Noroeste de la Provincia de Buenos Aires-CICBA), Pergamino, Argentina
- Centro de Investigaciones y Transferencias del Noroeste de la provincia de Buenos Aires (CITNOBA-CONICET), Pergamino, Argentina
| | - Elina Welchen
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Rolando Rivera-Pomar
- Centro de BioInvestigaciones (Universidad Nacional del Noroeste de la Provincia de Buenos Aires-CICBA), Pergamino, Argentina
- Centro de Investigaciones y Transferencias del Noroeste de la provincia de Buenos Aires (CITNOBA-CONICET), Pergamino, Argentina
- Centro Regional de Estudios Genómicos (Facultad de Ciencias Exactas, Universidad Nacional de La Plata), La Plata, Argentina
| | - María Inés Catalano
- Centro de BioInvestigaciones (Universidad Nacional del Noroeste de la Provincia de Buenos Aires-CICBA), Pergamino, Argentina
- Centro de Investigaciones y Transferencias del Noroeste de la provincia de Buenos Aires (CITNOBA-CONICET), Pergamino, Argentina
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A Review on Transcriptional Responses of Interactions between Insect Vectors and Plant Viruses. Cells 2022; 11:cells11040693. [PMID: 35203347 PMCID: PMC8870222 DOI: 10.3390/cells11040693] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/03/2022] [Accepted: 02/15/2022] [Indexed: 02/04/2023] Open
Abstract
This review provides a synopsis of transcriptional responses pertaining to interactions between plant viruses and the insect vectors that transmit them in diverse modes. In the process, it attempts to catalog differential gene expression pertinent to virus–vector interactions in vectors such as virus reception, virus cell entry, virus tissue tropism, virus multiplication, and vector immune responses. Whiteflies, leafhoppers, planthoppers, and thrips are the main insect groups reviewed, along with aphids and leaf beetles. Much of the focus on gene expression pertinent to vector–virus interactions has centered around whole-body RNA extraction, whereas data on virus-induced tissue-specific gene expression in vectors is limited. This review compares transcriptional responses in different insect groups following the acquisition of non-persistent, semi-persistent, and persistent (non-propagative and propagative) plant viruses and identifies parallels and divergences in gene expression patterns. Understanding virus-induced changes in vectors at a transcriptional level can aid in the identification of candidate genes for targeting with RNAi and/or CRISPR editing in insect vectors for management approaches.
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Ripamonti M, Cerone L, Abbà S, Rossi M, Ottati S, Palmano S, Marzachì C, Galetto L. Silencing of ATP Synthase β Impairs Egg Development in the Leafhopper Scaphoideus titanus, Vector of the Phytoplasma Associated with Grapevine Flavescence Dorée. Int J Mol Sci 2022; 23:765. [PMID: 35054956 PMCID: PMC8775575 DOI: 10.3390/ijms23020765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/29/2021] [Accepted: 01/07/2022] [Indexed: 11/17/2022] Open
Abstract
Scaphoideus titanus (Hemiptera: Cicadellidae) is the natural vector of Flavescence dorée phytoplasma, a quarantine pest of grapevine with severe impact on European viticulture. RNA interference (RNAi) machinery components are present in S. titanus transcriptome and injection of ATP synthase β dsRNAs into adults caused gene silencing, starting three days post injection (dpi) up to 20 dpi, leading to decrease cognate protein. Silencing of this gene in the closely related leafhopper Euscelidiusvariegatus previously showed female sterility and lack of mature eggs in ovaries. Here, alteration of developing egg morphology in S. titanus ovaries as well as overexpression of hexamerin transcript (amino acid storage protein) and cathepsin L protein (lysosome proteinase) were observed in dsATP-injected females. To evaluate RNAi-specificity, E.variegatus was used as dsRNA-receiving model-species. Different doses of two sets of dsRNA-constructs targeting distinct portions of ATP synthase β gene of both species induced silencing, lack of egg development, and female sterility in E. variegatus, indicating that off-target effects must be evaluated case by case. The effectiveness of RNAi in S. titanus provides a powerful tool for functional genomics of this non-model species and paves the way toward RNAi-based strategies to limit vector population, despite several technical and regulatory constraints that still need to be overcome to allow open field application.
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Affiliation(s)
- Matteo Ripamonti
- Istituto per la Protezione Sostenibile Delle Piante, Consiglio Nazionale Delle Ricerche, IPSP-CNR, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (L.C.); (S.A.); (M.R.); (S.O.); (S.P.); (C.M.)
- Environmental Research and Innovation Department (ERIN), Luxembourg Institute of Science and Technology (LIST), 41 Rue du Brill, 4422 Luxembourg, Luxembourg
| | - Luca Cerone
- Istituto per la Protezione Sostenibile Delle Piante, Consiglio Nazionale Delle Ricerche, IPSP-CNR, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (L.C.); (S.A.); (M.R.); (S.O.); (S.P.); (C.M.)
- Dipartimento di Scienze Agrarie, Forestali ed Alimentari DISAFA, Università degli Studi di Torino, Largo Paolo Braccini 2, Grugliasco, 10095 Torino, Italy
| | - Simona Abbà
- Istituto per la Protezione Sostenibile Delle Piante, Consiglio Nazionale Delle Ricerche, IPSP-CNR, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (L.C.); (S.A.); (M.R.); (S.O.); (S.P.); (C.M.)
| | - Marika Rossi
- Istituto per la Protezione Sostenibile Delle Piante, Consiglio Nazionale Delle Ricerche, IPSP-CNR, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (L.C.); (S.A.); (M.R.); (S.O.); (S.P.); (C.M.)
| | - Sara Ottati
- Istituto per la Protezione Sostenibile Delle Piante, Consiglio Nazionale Delle Ricerche, IPSP-CNR, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (L.C.); (S.A.); (M.R.); (S.O.); (S.P.); (C.M.)
- Dipartimento di Scienze Agrarie, Forestali ed Alimentari DISAFA, Università degli Studi di Torino, Largo Paolo Braccini 2, Grugliasco, 10095 Torino, Italy
| | - Sabrina Palmano
- Istituto per la Protezione Sostenibile Delle Piante, Consiglio Nazionale Delle Ricerche, IPSP-CNR, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (L.C.); (S.A.); (M.R.); (S.O.); (S.P.); (C.M.)
| | - Cristina Marzachì
- Istituto per la Protezione Sostenibile Delle Piante, Consiglio Nazionale Delle Ricerche, IPSP-CNR, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (L.C.); (S.A.); (M.R.); (S.O.); (S.P.); (C.M.)
| | - Luciana Galetto
- Istituto per la Protezione Sostenibile Delle Piante, Consiglio Nazionale Delle Ricerche, IPSP-CNR, Strada delle Cacce 73, 10135 Torino, Italy; (M.R.); (L.C.); (S.A.); (M.R.); (S.O.); (S.P.); (C.M.)
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Rajarapu SP, Ullman DE, Uzest M, Rotenberg D, Ordaz NA, Whitfield AE. Plant–Virus–Vector Interactions. Virology 2021. [DOI: 10.1002/9781119818526.ch7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Galetto L, Abbà S, Rossi M, Ripamonti M, Palmano S, Bosco D, Marzachì C. Silencing of ATP synthase β reduces phytoplasma multiplication in a leafhopper vector. JOURNAL OF INSECT PHYSIOLOGY 2021; 128:104176. [PMID: 33253714 DOI: 10.1016/j.jinsphys.2020.104176] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/25/2020] [Accepted: 11/25/2020] [Indexed: 06/12/2023]
Abstract
The leafhopper Euscelidius variegatus is a natural vector of the chrysanthemum yellows phytoplasma (CYp) and a laboratory vector of the Flavescence dorée phytoplasma (FDp). Previous studies indicated a crucial role for insect ATP synthase α and β subunits during phytoplasma infection of the vector species. Gene silencing of ATP synthase β was obtained by injection of specific dsRNAs in E. variegatus. Here we present the long-lasting nature of such silencing, its effects on the small RNA profile, the significant reduction of the corresponding protein expression, and the impact on phytoplasma acquisition capability. The specific transcript expression was silenced at least up to 37 days post injection with an average reduction of 100 times in insects injected with dsRNAs targeting ATP synthase β (dsATP) compared with those injected with dsRNAs targeting green fluorescent protein (dsGFP), used as negative controls. Specific silencing of this gene was also confirmed at protein level at 15 days after the injection. Total sRNA reads mapping to dsATP and dsGFP sequences in analysed libraries showed in both cases a peak of 21 nt, a length consistent with the generation of dsRNA-derived siRNAs by RNAi pathway. Reads mapped exclusively to the fragment corresponding to the injected dsATPs, probably indicating the absence of a secondary machinery for siRNA synthesis. Insects injected either with dsATP or dsGFP successfully acquired CYp and FDp during feeding on infected plants. However, the average phytoplasma amount in dsATP insects was significantly lower than that measured in dsGFP specimens, indicating a probable reduction of the pathogen multiplication when ATP synthase β was silenced. The role of the insect ATP synthase β during phytoplasma infection process is discussed.
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Affiliation(s)
- Luciana Galetto
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, IPSP-CNR, Strada delle Cacce 73 10135 Torino, Italy.
| | - Simona Abbà
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, IPSP-CNR, Strada delle Cacce 73 10135 Torino, Italy.
| | - Marika Rossi
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, IPSP-CNR, Strada delle Cacce 73 10135 Torino, Italy.
| | - Matteo Ripamonti
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, IPSP-CNR, Strada delle Cacce 73 10135 Torino, Italy; Dipartimento di Scienze Agrarie, Forestali ed Alimentari DISAFA, Università degli Studi di Torino, Largo Paolo Braccini 2, 10095 Grugliasco (TO), Italy.
| | - Sabrina Palmano
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, IPSP-CNR, Strada delle Cacce 73 10135 Torino, Italy.
| | - Domenico Bosco
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, IPSP-CNR, Strada delle Cacce 73 10135 Torino, Italy; Dipartimento di Scienze Agrarie, Forestali ed Alimentari DISAFA, Università degli Studi di Torino, Largo Paolo Braccini 2, 10095 Grugliasco (TO), Italy.
| | - Cristina Marzachì
- Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche, IPSP-CNR, Strada delle Cacce 73 10135 Torino, Italy.
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6
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Jain RG, Robinson KE, Fletcher SJ, Mitter N. RNAi-Based Functional Genomics in Hemiptera. INSECTS 2020; 11:E557. [PMID: 32825516 PMCID: PMC7564473 DOI: 10.3390/insects11090557] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/17/2020] [Accepted: 08/17/2020] [Indexed: 01/05/2023]
Abstract
RNA interference (RNAi) is a powerful approach for sequence-specific gene silencing, displaying tremendous potential for functional genomics studies in hemipteran insects. Exploiting RNAi allows the biological roles of critical genes to be defined and aids the development of RNAi-based biopesticides. In this review, we provide context to the rapidly expanding field of RNAi-based functional genomics studies in hemipteran insects. We highlight the most widely used RNAi delivery strategies, including microinjection, oral ingestion and topical application. Additionally, we discuss the key variables affecting RNAi efficacy in hemipteran insects, including insect life-stage, gene selection, the presence of nucleases, and the role of core RNAi machinery. In conclusion, we summarise the application of RNAi in functional genomics studies in Hemiptera, focusing on genes involved in reproduction, behaviour, metabolism, immunity and chemical resistance across 33 species belonging to 14 families.
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Affiliation(s)
| | - Karl E. Robinson
- Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural Sciences, The University of Queensland, Brisbane 4072, Queensland, Australia; (R.G.J.); (S.J.F.); (N.M.)
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Whitfield AE, Huot OB, Martin KM, Kondo H, Dietzgen RG. Plant rhabdoviruses-their origins and vector interactions. Curr Opin Virol 2018; 33:198-207. [PMID: 30500682 DOI: 10.1016/j.coviro.2018.11.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/05/2018] [Accepted: 11/07/2018] [Indexed: 02/06/2023]
Abstract
Classical plant rhabdoviruses infect monocot and dicot plants, have unsegmented negative-sense RNA genomes and have been taxonomically classified in the genera Cytorhabdovirus and Nucleorhabdovirus. These viruses replicate in their hemipteran vectors and are transmitted in a circulative-propagative mode and virus infection persists for the life of the insect. Based on the discovery of numerous novel rhabdoviruses in arthropods during metagenomic studies and extensive phylogenetic analyses of the family Rhabdoviridae, it is hypothesized that plant-infecting rhabdoviruses are derived from insect viruses. Analyses of viral gene function in plants and insects is beginning to reveal conserved and unique biology for these plant viruses in the two diverse hosts. New tools for insect molecular biology and infectious clones for plant rhabdoviruses are increasing our understanding of the lifestyles of these viruses.
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Affiliation(s)
- Anna E Whitfield
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, United States.
| | - Ordom Brian Huot
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, United States
| | - Kathleen M Martin
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, United States
| | - Hideki Kondo
- Institute of Plant Science and Resource, Okayama University, Kurashiki, 710-0046, Japan
| | - Ralf G Dietzgen
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, Queensland 4072, Australia
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Zhao P, Xia F, Jiang L, Guo H, Xu G, Sun Q, Wang B, Wang Y, Lu Z, Xia Q. Enhanced antiviral immunity against Bombyx mori cytoplasmic polyhedrosis virus via overexpression of peptidoglycan recognition protein S2 in transgenic silkworms. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 87:84-89. [PMID: 29902708 DOI: 10.1016/j.dci.2018.05.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 05/13/2018] [Accepted: 05/30/2018] [Indexed: 06/08/2023]
Abstract
In insect innate immunity, peptidoglycan recognition proteins act as pattern recognition receptors, helping hosts combat invasive microorganisms. Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) is the main silkworm pathogen that invades the midgut columnar cell layer. We previously reported that B. mori peptidoglycan recognition protein S2 (BmPGRP-S2) was upregulated in silkworm larvae after BmCPV infection. Here, we constructed a transgenic vector overexpressing BmPGRP-S2 under the control of a midgut-specific promoter. Transgenic silkworm lines (PGRPS2-1 and PGRPS2-2) were generated via embryonic microinjection. BmPGRP-S2 was successfully overexpressed in transgenic silkworms and BmE cells. After oral inoculation with BmCPV, the mortality of PGRPS2-1 and PGRPS2-2 decreased by approximately 36% and 32%, respectively, compared with that of the non-transgenic line, and BmCPV mRNA contents were significantly lower. In the PGRPS2-1 line, imd, relish, and the antimicrobial peptide (AMP) genes attacin2, gloverin2, and moricin showed increased expression after viral infection; however, the Toll pathway was not activated. These results indicate that BmPGRP-S2 overexpression can activate the Imd pathway and induce AMP upregulation, enhancing silkworm antiviral resistance.
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Affiliation(s)
- Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China
| | - Fei Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China
| | - Liang Jiang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China
| | - Huizhen Guo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China
| | - Guowen Xu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China
| | - Qiang Sun
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China
| | - Bingbing Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China
| | - Yumei Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China
| | - Zhongyan Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China.
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RNA Interference in Insect Vectors for Plant Viruses. Viruses 2016; 8:v8120329. [PMID: 27973446 PMCID: PMC5192390 DOI: 10.3390/v8120329] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 12/05/2016] [Accepted: 12/06/2016] [Indexed: 01/09/2023] Open
Abstract
Insects and other arthropods are the most important vectors of plant pathogens. The majority of plant pathogens are disseminated by arthropod vectors such as aphids, beetles, leafhoppers, planthoppers, thrips and whiteflies. Transmission of plant pathogens and the challenges in managing insect vectors due to insecticide resistance are factors that contribute to major food losses in agriculture. RNA interference (RNAi) was recently suggested as a promising strategy for controlling insect pests, including those that serve as important vectors for plant pathogens. The last decade has witnessed a dramatic increase in the functional analysis of insect genes, especially those whose silencing results in mortality or interference with pathogen transmission. The identification of such candidates poses a major challenge for increasing the role of RNAi in pest control. Another challenge is to understand the RNAi machinery in insect cells and whether components that were identified in other organisms are also present in insect. This review will focus on summarizing success cases in which RNAi was used for silencing genes in insect vector for plant pathogens, and will be particularly helpful for vector biologists.
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Dietzgen RG, Mann KS, Johnson KN. Plant Virus-Insect Vector Interactions: Current and Potential Future Research Directions. Viruses 2016; 8:E303. [PMID: 27834855 PMCID: PMC5127017 DOI: 10.3390/v8110303] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/31/2016] [Accepted: 10/31/2016] [Indexed: 12/13/2022] Open
Abstract
Acquisition and transmission by an insect vector is central to the infection cycle of the majority of plant pathogenic viruses. Plant viruses can interact with their insect host in a variety of ways including both non-persistent and circulative transmission; in some cases, the latter involves virus replication in cells of the insect host. Replicating viruses can also elicit both innate and specific defense responses in the insect host. A consistent feature is that the interaction of the virus with its insect host/vector requires specific molecular interactions between virus and host, commonly via proteins. Understanding the interactions between plant viruses and their insect host can underpin approaches to protect plants from infection by interfering with virus uptake and transmission. Here, we provide a perspective focused on identifying novel approaches and research directions to facilitate control of plant viruses by better understanding and targeting virus-insect molecular interactions. We also draw parallels with molecular interactions in insect vectors of animal viruses, and consider technical advances for their control that may be more broadly applicable to plant virus vectors.
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Affiliation(s)
- Ralf G Dietzgen
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia QLD 4072, Australia.
| | - Krin S Mann
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, BC V0H 1Z0, Canada.
| | - Karyn N Johnson
- School of Biological Sciences, The University of Queensland, St. Lucia QLD 4072, Australia.
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Small interfering RNA pathway modulates persistent infection of a plant virus in its insect vector. Sci Rep 2016; 6:20699. [PMID: 26864546 PMCID: PMC4750021 DOI: 10.1038/srep20699] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 01/11/2016] [Indexed: 11/08/2022] Open
Abstract
Plant reoviruses, rhabdoviruses, tospoviruses, and tenuiviruses are transmitted by insect vectors in a persistent-propagative manner. How such persistent infection of plant viruses in insect vectors is established and maintained remains poorly understood. In this study, we used rice gall dwarf virus (RGDV), a plant reovirus, and its main vector leafhopper Recilia dorsalis as a virus-insect system to determine how the small interference (siRNA) pathway modulates persistent infection of a plant virus in its insect vector. We showed that a conserved siRNA antiviral response was triggered by the persistent replication of RGDV in cultured leafhopper cells and in intact insects, by appearance of virus-specific siRNAs, primarily 21-nt long, and the increased expression of siRNA pathway core components Dicer-2 and Argonaute-2. Silencing of Dicer-2 using RNA interference strongly suppressed production of virus-specific siRNAs, promoted viral accumulation, and caused cytopathological changes in vitro and in vivo. When the viral accumulation level rose above a certain threshold of viral genome copy (1.32 × 10(14) copies/μg insect RNA), the infection of the leafhopper by RGDV was lethal rather than persistent. Taken together, our results revealed a new finding that the siRNA pathway in insect vector can modulate persistent infection of plant viruses.
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Lan H, Chen H, Liu Y, Jiang C, Mao Q, Jia D, Chen Q, Wei T. Small Interfering RNA Pathway Modulates Initial Viral Infection in Midgut Epithelium of Insect after Ingestion of Virus. J Virol 2016; 90:917-29. [PMID: 26537672 PMCID: PMC4702677 DOI: 10.1128/jvi.01835-15] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 10/26/2015] [Indexed: 01/22/2023] Open
Abstract
UNLABELLED Numerous viruses are transmitted in a persistent manner by insect vectors. Persistent viruses establish their initial infection in the midgut epithelium, from where they disseminate to the midgut visceral muscles. Although propagation of viruses in insect vectors can be controlled by the small interfering RNA (siRNA) antiviral pathway, whether the siRNA pathway can control viral dissemination from the midgut epithelium is unknown. Infection by a rice virus (Southern rice black streaked dwarf virus [SRBSDV]) of its incompetent vector (the small brown planthopper [SBPH]) is restricted to the midgut epithelium. Here, we show that the siRNA pathway is triggered by SRBSDV infection in continuously cultured cells derived from the SBPH and in the midgut of the intact insect. Knockdown of the expression of the core component Dicer-2 of the siRNA pathway by RNA interference strongly increased the ability of SRBSDV to propagate in continuously cultured SBPH cells and in the midgut epithelium, allowing viral titers in the midgut epithelium to reach the threshold (1.99 × 10(9) copies of the SRBSDV P10 gene/μg of midgut RNA) needed for viral dissemination into the SBPH midgut muscles. Our results thus represent the first elucidation of the threshold for viral dissemination from the insect midgut epithelium. Silencing of Dicer-2 further facilitated the transmission of SRBSDV into rice plants by SBPHs. Taken together, our results reveal the new finding that the siRNA pathway can control the initial infection of the insect midgut epithelium by a virus, which finally affects the competence of the virus's vector. IMPORTANCE Many viral pathogens that cause significant global health and agricultural problems are transmitted via insect vectors. The first bottleneck in viral infection, the midgut epithelium, is a principal determinant of the ability of an insect species to transmit a virus. Southern rice black streaked dwarf virus (SRBSDV) is restricted exclusively to the midgut epithelium of an incompetent vector, the small brown planthopper (SBPH). Here, we show that silencing of the core component Dicer-2 of the small interfering RNA (siRNA) pathway increases viral titers in the midgut epithelium past the threshold (1.99 × 10(9) copies of the SRBSDV P10 gene/μg of midgut RNA) for viral dissemination into the midgut muscles and then into the salivary glands, allowing the SBPH to become a competent vector of SRBSDV. This result is the first evidence that the siRNA antiviral pathway has a direct role in the control of viral dissemination from the midgut epithelium and that it affects the competence of the virus's vector.
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Affiliation(s)
- Hanhong Lan
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, People's Republic of China
| | - Hongyan Chen
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, People's Republic of China
| | - Yuyan Liu
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, People's Republic of China
| | - Chaoyang Jiang
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, People's Republic of China
| | - Qianzhuo Mao
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, People's Republic of China
| | - Dongsheng Jia
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, People's Republic of China
| | - Qian Chen
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, People's Republic of China
| | - Taiyun Wei
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, People's Republic of China
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Eliautout R, Dubrana MP, Vincent-Monégat C, Vallier A, Braquart-Varnier C, Poirié M, Saillard C, Heddi A, Arricau-Bouvery N. Immune response and survival of Circulifer haematoceps to Spiroplasma citri infection requires expression of the gene hexamerin. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2016; 54:7-19. [PMID: 26279217 DOI: 10.1016/j.dci.2015.08.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 08/10/2015] [Accepted: 08/11/2015] [Indexed: 06/04/2023]
Abstract
Spiroplasma citri is a cell wall-less bacterium that infects plants. It is transmitted by the leafhopper Circulifer haematoceps, which hosts this bacterium in the haemocel and insect tissues. Bacterial factors involved in spiroplasma colonization of the insect host have been identified, but the immune response of the leafhopper to S. citri infection remains unknown. In this study, we showed that C. haematoceps activates both humoral and cellular immune responses when challenged with bacteria. When infected by S. citri, C. haematoceps displayed a specific immune response, evidenced by activation of phagocytosis and upregulation of a gene encoding the protein hexamerin. S. citri infection also resulted in decreased phenoloxidase-like activity. Inhibition of hexamerin by RNA interference resulted in a significant reduction in phenoloxidase-like activity and increased mortality of infected leafhoppers. Therefore, the gene hexamerin is involved in S. citri control by interfering with insect phenoloxidase activity.
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Affiliation(s)
- Rémi Eliautout
- Institut National de la Recherche Agronomique (INRA), UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France; Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France
| | - Marie-Pierre Dubrana
- Institut National de la Recherche Agronomique (INRA), UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France; Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France
| | - Carole Vincent-Monégat
- Université de Lyon, INSA-Lyon, INRA, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, F-69621 Villeurbanne, France
| | - Agnès Vallier
- Université de Lyon, INSA-Lyon, INRA, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, F-69621 Villeurbanne, France
| | - Christine Braquart-Varnier
- Université de Poitiers, UMR CNRS 7267 Ecologie et Biologie des Interactions, Equipe Ecologie, Evolution, Symbiose
| | - Marylène Poirié
- INRA, Evolution and Specificity of Multitrophic Interactions (ESIM), UMR 1355 Institut Sophia Agrobiotech (ISA), Sophia Antipolis, France
| | - Colette Saillard
- Institut National de la Recherche Agronomique (INRA), UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France; Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France
| | - Abdelaziz Heddi
- Université de Lyon, INSA-Lyon, INRA, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, F-69621 Villeurbanne, France
| | - Nathalie Arricau-Bouvery
- Institut National de la Recherche Agronomique (INRA), UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France; Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
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