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Chaudhary D, Jeena AS, Rohit, Gaur S, Raj R, Mishra S, Kajal, Gupta OP, Meena MR. Advances in RNA Interference for Plant Functional Genomics: Unveiling Traits, Mechanisms, and Future Directions. Appl Biochem Biotechnol 2024:10.1007/s12010-023-04850-x. [PMID: 38175411 DOI: 10.1007/s12010-023-04850-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2023] [Indexed: 01/05/2024]
Abstract
RNA interference (RNAi) is a conserved molecular mechanism that plays a critical role in post-transcriptional gene silencing across diverse organisms. This review delves into the role of RNAi in plant functional genomics and its applications in crop improvement, highlighting its mechanistic insights and practical implications. The review begins with the foundational discovery of RNAi's mechanism, tracing its origins from petunias to its widespread presence in various organisms. Various classes of regulatory non-coding small RNAs, including siRNAs, miRNAs, and phasiRNAs, have been uncovered, expanding the scope of RNAi-mediated gene regulation beyond conventional understanding. These RNA classes participate in intricate post-transcriptional and epigenetic processes that influence gene expression. In the context of crop enhancement, RNAi has emerged as a powerful tool for understanding gene functions. It has proven effective in deciphering gene roles related to stress resistance, metabolic pathways, and more. Additionally, RNAi-based approaches hold promise for integrated pest management and sustainable agriculture, contributing to global efforts in food security. This review discusses RNAi's diverse applications, such as modifying plant architecture, extending shelf life, and enhancing nutritional content in crops. The challenges and future prospects of RNAi technology, including delivery methods and biosafety concerns, are also explored. The global landscape of RNAi research is highlighted, with significant contributions from regions such as China, Europe, and North America. In conclusion, RNAi remains a versatile and pivotal tool in modern plant research, offering novel avenues for understanding gene functions and improving crop traits. Its integration with other biotechnological approaches such as gene editing holds the potential to shape the future of agriculture and sustainable food production.
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Affiliation(s)
- Divya Chaudhary
- Department of Genetics and Plant Breeding, College of Agriculture, G B Pant University of Agriculture and Technology, Pantnagar, 263145, Uttarakhand, India
| | - Anand Singh Jeena
- Department of Genetics and Plant Breeding, College of Agriculture, G B Pant University of Agriculture and Technology, Pantnagar, 263145, Uttarakhand, India.
| | - Rohit
- Department of Genetics and Plant Breeding, College of Agriculture, G B Pant University of Agriculture and Technology, Pantnagar, 263145, Uttarakhand, India
| | - Sonali Gaur
- Department of Genetics and Plant Breeding, College of Agriculture, G B Pant University of Agriculture and Technology, Pantnagar, 263145, Uttarakhand, India
| | - Rishi Raj
- ICAR- Sugarcane Breeding Institute-Regional Centre, Karnal, 132001, Haryana, India
| | | | - Kajal
- Department of Biotechnology, Chandigarh University, Chandigarh, 140143, India
| | - Om Prakash Gupta
- ICAR-Indian Institute of Wheat and Barley Research, Karnal, 132001, Haryana, India.
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2
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Halder K, Chaudhuri A, Abdin MZ, Datta A. Tweaking the Small Non-Coding RNAs to Improve Desirable Traits in Plant. Int J Mol Sci 2023; 24:ijms24043143. [PMID: 36834556 PMCID: PMC9966754 DOI: 10.3390/ijms24043143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/20/2023] [Accepted: 01/25/2023] [Indexed: 02/09/2023] Open
Abstract
Plant transcriptome contains an enormous amount of non-coding RNAs (ncRNAs) that do not code for proteins but take part in regulating gene expression. Since their discovery in the early 1990s, much research has been conducted to elucidate their function in the gene regulatory network and their involvement in plants' response to biotic/abiotic stresses. Typically, 20-30 nucleotide-long small ncRNAs are a potential target for plant molecular breeders because of their agricultural importance. This review summarizes the current understanding of three major classes of small ncRNAs: short-interfering RNAs (siRNAs), microRNA (miRNA), and transacting siRNAs (tasiRNAs). Furthermore, their biogenesis, mode of action, and how they have been utilized to improve crop productivity and disease resistance are discussed here.
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Affiliation(s)
- Koushik Halder
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
- Centre for Transgenic Plant Development, Department of Biotechnology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Abira Chaudhuri
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
- Correspondence: (A.C.); (A.D.); Tel.: +91-1126742750 or +91-1126735119 (A.D.)
| | - Malik Z. Abdin
- Centre for Transgenic Plant Development, Department of Biotechnology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Asis Datta
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
- Correspondence: (A.C.); (A.D.); Tel.: +91-1126742750 or +91-1126735119 (A.D.)
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3
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Bharathi JK, Anandan R, Benjamin LK, Muneer S, Prakash MAS. Recent trends and advances of RNA interference (RNAi) to improve agricultural crops and enhance their resilience to biotic and abiotic stresses. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 194:600-618. [PMID: 36529010 DOI: 10.1016/j.plaphy.2022.11.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 11/04/2022] [Accepted: 11/26/2022] [Indexed: 06/17/2023]
Abstract
Over the last two decades, significant advances have been made using genetic engineering technology to modify genes from various exotic origins and introduce them into plants to induce favorable traits. RNA interference (RNAi) was discovered earlier as a natural process for controlling the expression of genes across all higher species. It aims to enhance precision and accuracy in pest/pathogen resistance, quality improvement, and manipulating the architecture of plants. However, it existed as a widely used technique recently. RNAi technologies could well be used to down-regulate any genes' expression without disrupting the expression of other genes. The use of RNA interference to silence genes in various organisms has become the preferred method for studying gene functions. The establishment of new approaches and applications for enhancing desirable characters is essential in crops by gene suppression and the refinement of knowledge of endogenous RNAi mechanisms in plants. RNAi technology in recent years has become an important and choicest method for controlling insects, pests, pathogens, and abiotic stresses like drought, salinity, and temperature. Although there are certain drawbacks in efficiency of this technology such as gene candidate selection, stability of trigger molecule, choice of target species and crops. Nevertheless, from past decade several target genes has been identified in numerous crops for their improvement towards biotic and abiotic stresses. The current review is aimed to emphasize the research done on crops under biotic and abiotic stress using RNAi technology. The review also highlights the gene regulatory pathways/gene silencing, RNA interference, RNAi knockdown, RNAi induced biotic and abiotic resistance and advancements in the understanding of RNAi technology and the functionality of various components of the RNAi machinery in crops for their improvement.
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Affiliation(s)
- Jothi Kanmani Bharathi
- Department of Genetics and Plant Breeding, Faculty of Agriculture, Annamalai University, Annamalai Nagar, 608 002, Tamil Nadu, India
| | - Ramaswamy Anandan
- Department of Genetics and Plant Breeding, Faculty of Agriculture, Annamalai University, Annamalai Nagar, 608 002, Tamil Nadu, India
| | - Lincy Kirubhadharsini Benjamin
- Horticulture and Molecular Physiology Lab, School of Agricultural Innovations and Advanced Learning, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India
| | - Sowbiya Muneer
- Horticulture and Molecular Physiology Lab, School of Agricultural Innovations and Advanced Learning, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India.
| | - Muthu Arjuna Samy Prakash
- Department of Genetics and Plant Breeding, Faculty of Agriculture, Annamalai University, Annamalai Nagar, 608 002, Tamil Nadu, India.
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4
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Bilir Ö, Göl D, Hong Y, McDowell JM, Tör M. Small RNA-based plant protection against diseases. FRONTIERS IN PLANT SCIENCE 2022; 13:951097. [PMID: 36061762 PMCID: PMC9434005 DOI: 10.3389/fpls.2022.951097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/28/2022] [Indexed: 06/15/2023]
Abstract
Plant diseases cause significant decreases in yield and quality of crops and consequently pose a very substantial threat to food security. In the continuous search for environmentally friendly crop protection, exploitation of RNA interferance machinery is showing promising results. It is well established that small RNAs (sRNAs) including microRNA (miRNA) and small interfering RNA (siRNA) are involved in the regulation of gene expression via both transcriptional and post-transcriptional RNA silencing. sRNAs from host plants can enter into pathogen cells during invasion and silence pathogen genes. This process has been exploited through Host-Induced Gene Silencing (HIGS), in which plant transgenes that produce sRNAs are engineered to silence pest and pathogen genes. Similarly, exogenously applied sRNAs can enter pest and pathogen cells, either directly or via the hosts, and silence target genes. This process has been exploited in Spray-Induced Gene Silencing (SIGS). Here, we focus on the role of sRNAs and review how they have recently been used against various plant pathogens through HIGS or SIGS-based methods and discuss advantages and drawbacks of these approaches.
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Affiliation(s)
- Özlem Bilir
- Department of Biotechnology, Trakya Agricultural Research Institute, Edirne, Turkey
| | - Deniz Göl
- Department of Biology, School of Science and the Environment, University of Worcester, Worcester, United Kingdom
| | - Yiguo Hong
- Department of Biology, School of Science and the Environment, University of Worcester, Worcester, United Kingdom
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - John M. McDowell
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Mahmut Tör
- Department of Biology, School of Science and the Environment, University of Worcester, Worcester, United Kingdom
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Transgenic Rice Plants Expressing Artificial miRNA Targeting the Rice Stripe Virus MP Gene Are Highly Resistant to the Virus. BIOLOGY 2022; 11:biology11020332. [PMID: 35205198 PMCID: PMC8869529 DOI: 10.3390/biology11020332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 02/15/2022] [Accepted: 02/16/2022] [Indexed: 11/29/2022]
Abstract
Simple Summary Rice stripe virus is a disastrous viral disease that causes significant yield losses in rice production in South, Southeast, and East Asian countries. To decrease the use of chemical insecticides, genetic engineering has become a pivotal strategy to combat the virus. In this study, we constructed a dimeric artificial microRNA precursor expression vector that targets the viral MP gene based on the structure of the rice osa-MIR528 precursor. Marker-free transgenic plants successfully expressing the MP amiRNAs were obtained and were highly resistant to RSV infection. The novel rice germplasms generated are promising for RSV control. Abstract Rice stripe virus (RSV) causes one of the most serious viral diseases of rice. RNA interference is one of the most efficient ways to control viral disease. In this study, we constructed an amiRNA targeting the RSV MP gene (amiR MP) based on the backbone sequence of the osa-MIR528 precursor, and obtained marker-free transgenic rice plants constitutively expressing amiR MP by Agrobacterium tumefaciens-mediated transformation. A transient expression assay demonstrated that dimeric amiR MP could be effectively recognized and cleaved at the target MP gene in plants. Northern blot of miRNA indicated that amiR MP-mediated viral resistance could be stably inherited. The transgenic rice plants were highly resistant to RSV (73–90%). Our research provides novel rice germplasm for RSV control.
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Lacombe S, Bangratz M, Ta HA, Nguyen TD, Gantet P, Brugidou C. Optimized RNA-Silencing Strategies for Rice Ragged Stunt Virus Resistance in Rice. PLANTS 2021; 10:plants10102008. [PMID: 34685817 PMCID: PMC8540896 DOI: 10.3390/plants10102008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/31/2021] [Accepted: 09/21/2021] [Indexed: 11/16/2022]
Abstract
Rice ragged stunt virus (RRSV) is one of the most damaging viruses of the rice culture area in south and far-eastern Asia. To date, no genetic resistance has been identified and only expensive and non-environmentally friendly chemical treatments are deployed to fight this important disease. Non-chemical approaches based on RNA-silencing have been developed as resistance strategies against viruses. Here, we optimized classical miRNA and siRNA-based strategies to obtain efficient and durable resistance to RRSV. miRNA-based strategies are involved in producing artificial miRNA (amiR) targeting viral genomes in plants. Classically, only one amiR is produced from a single construct. We demonstrated for the first time that two amiRs targeting conserved regions of RRSV genomes could be transgenically produced in Nicotiana benthamiana and in rice for a single precursor. Transgenic rice plants producing either one or two amiR were produced. Despite efficient amiR accumulations, miRNA-based strategies with single or double amiRs failed to achieve efficient RRSV resistance in transformed rice plants. This suggests that this strategy may not be adapted to RRSV, which could rapidly evolve to counteract them. Another RNA-silencing-based method for viral resistance concerns producing several viral siRNAs targeting a viral fragment. These viral siRNAs are produced from an inverted repeat construct carrying the targeted viral fragment. Here, we optimized the inverted repeat construct using a chimeric fragment carrying conserved sequences of three different RRSV genes instead of one. Of the three selected homozygous transgenic plants, one failed to accumulate the expected siRNA. The two other ones accumulated siRNAs from either one or three fragments. A strong reduction of RRSV symptoms was observed only in transgenic plants expressing siRNAs. We consequently demonstrated, for the first time, an efficient and environmentally friendly resistance to RRSV in rice based on the siRNA-mediated strategy.
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Affiliation(s)
- Severine Lacombe
- PHIM Plant Health Institute, University Montpellier, IRD, CIRAD, INRAE, Institut Agro, 34090 Montpellier, France; (M.B.); (C.B.)
- Correspondence:
| | - Martine Bangratz
- PHIM Plant Health Institute, University Montpellier, IRD, CIRAD, INRAE, Institut Agro, 34090 Montpellier, France; (M.B.); (C.B.)
| | - Hoang Anh Ta
- Plant Protection Research Institute (PPRI), Bac Tu Liem District, Hanoi 10000, Vietnam;
| | - Thanh Duc Nguyen
- Agricultural Genetics Institute, Bac Tu Liem District, Hanoi 10000, Vietnam;
| | - Pascal Gantet
- UMR DIADE, Université de Montpellier, IRD, 34090 Montpellier, France;
| | - Christophe Brugidou
- PHIM Plant Health Institute, University Montpellier, IRD, CIRAD, INRAE, Institut Agro, 34090 Montpellier, France; (M.B.); (C.B.)
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7
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Metabolic Analysis Reveals Cry1C Gene Transformation Does Not Affect the Sensitivity of Rice to Rice Dwarf Virus. Metabolites 2021; 11:metabo11040209. [PMID: 33808359 PMCID: PMC8065979 DOI: 10.3390/metabo11040209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 03/22/2021] [Accepted: 03/29/2021] [Indexed: 12/16/2022] Open
Abstract
Metabolomics is beginning to be used for assessing unintended changes in genetically modified (GM) crops. To investigate whether Cry1C gene transformation would induce metabolic changes in rice plants, and whether the metabolic changes would pose potential risks when Cry1C rice plants are exposed to rice dwarf virus (RDV), the metabolic profiles of Cry1C rice T1C-19 and its non-Bt parental rice MH63 under RDV-free and RDV-infected status were analyzed using gas chromatography–mass spectrometry (GC-MS). Compared to MH63 rice, slice difference was detected in T1C-19 under RDV-free conditions (less than 3%), while much more metabolites showed significant response to RDV infection in T1C-19 (15.6%) and in MH63 (5.0%). Pathway analysis showed biosynthesis of lysine, valine, leucine, and isoleucine may be affected by RDV infection in T1C-19. No significant difference in the contents of free amino acids (AAs) was found between T1C-19 and MH63 rice, and the free AA contents of the two rice plants showed similar responses to RDV infection. Furthermore, no significant differences of the RDV infection rates between T1C-19 and MH63 were detected. Our results showed the Cry1C gene transformation did not affect the sensitivity of rice to RDV, indicating Cry1C rice would not aggravate the epidemic and dispersal of RDV.
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Jekayinoluwa T, Tripathi L, Tripathi JN, Ntui VO, Obiero G, Muge E, Dale J. RNAi technology for management of banana bunchy top disease. Food Energy Secur 2020; 9:e247. [PMID: 33381301 PMCID: PMC7757248 DOI: 10.1002/fes3.247] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 08/13/2020] [Accepted: 08/16/2020] [Indexed: 12/15/2022] Open
Abstract
Banana bunchy top disease (BBTD) is one of the world's most destructive viral diseases of banana and plantain, causing up to 100% yield loss in severe cases. The disease is vectored by banana aphids (Pentalonia nigronervosa) and carried long distances through the movement of infected plant materials. The banana aphids harboring banana bunchy top virus (BBTV) present in banana producing regions are the sole vector and the most efficient method of transmitting the virus to the healthy plants. Controlling the spread of BBTD has been very challenging since no known banana germplasm is immune to BBTV. The disease can be managed with the use of virus-free planting material and roguing. However, once BBTD is established in the field, it is very difficult to eradicate or manage it. Therefore, a more sustainable way of controlling the disease is developing host plant resistance against the virus and the vector. Biotechnological strategies via RNA interference (RNAi) could be used to target the banana aphid as well as BBTV to reduce virus-associated yield losses of banana and plantain, which feed over 500 million people around the world. This review discusses the status of BBTD and perspectives on effective RNAi technologies for controlling BBTV and the vector, banana aphid, transmitting the virus as sustainable management of the disease.
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Affiliation(s)
- Temitope Jekayinoluwa
- International Institute of Tropical AgricultureNairobiKenya
- Center for Biotechnology and BioinformaticsUniversity of NairobiNairobiKenya
| | - Leena Tripathi
- International Institute of Tropical AgricultureNairobiKenya
| | | | | | - George Obiero
- Center for Biotechnology and BioinformaticsUniversity of NairobiNairobiKenya
| | - Edward Muge
- Department of BiochemistryUniversity of NairobiNairobiKenya
| | - James Dale
- Queensland University of TechnologyBrisbaneQldAustralia
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Omics applications: towards a sustainable protection of tomato. Appl Microbiol Biotechnol 2020; 104:4185-4195. [PMID: 32185431 DOI: 10.1007/s00253-020-10500-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 02/20/2020] [Accepted: 02/26/2020] [Indexed: 12/20/2022]
Abstract
Transcriptome data and gene expression analysis have a huge potential in the study of multiple relationships involving plants, pathogens, and pests, including the interactions with beneficial microorganisms such as endophytes or other functional groups. Next-generation sequencing (NGS) and other recent long-read-based sequencing approaches (i.e., nanopore and others) provide unprecedented tools allowing the fast identification of plant information processing systems, in situ and in real time, fundamental for crop management and pest regulation. Other -omics approaches such as metagenomics and metatranscriptomics allow high-resolution insights on the rhizosphere ecology. They may highlight key factors affecting belowground biodiversity or processes, modulating the expression of stress-responsive pathways. The application of miRNAs and other small RNAs is a relatively new field of application, with enormous potential for the selective activation of defense pathways. However, limitations concerning the stability of the RNA molecules and their effective delivery must be overcome.
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10
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Jabbar B, Iqbal MS, Batcho AA, Nasir IA, Rashid B, Husnain T, Henry RJ. Target prediction of candidate miRNAs from Oryza sativa for silencing the RYMV genome. Comput Biol Chem 2019; 83:107127. [PMID: 31542706 DOI: 10.1016/j.compbiolchem.2019.107127] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 04/02/2019] [Accepted: 09/12/2019] [Indexed: 11/29/2022]
Abstract
In order to maintain a consistent supply of rice globally, control of pathogens affecting crop production is a matter of due concern. Rice yellow mottle virus(RYMV) is known to cause a variety of symptoms which can result in reduced yield. Four ORFs can be identified in the genome of RYMV encoding for P1 (ORF1), Polyprotein (processed to produce VPg, protease, helicase, RdRp4) (ORF2), putative RdRp (ORF3) and capsid/coat protein (ORF4). This research was aimed at identifying genome encoded miRNAs of O. sativa that are targeted to the genome of Rice Yellow Mottle Virus (RYMV). A consensus of four miRNA target prediction algorithms (RNA22, miRanda, TargetFinder and psRNATarget) was computed, followed by calculation of free energies of miRNA-mRNA duplex formation. A phylogenetic tree was constructed to portray the evolutionary relationships between RYMV strains isolated to date. From the consensus of algorithms used, a total of seven O. sativa miRNAs were predicted and conservation of target site was finally evaluated. Predicted miRNAs can be further evaluated by experiments involving the testing of the success of in vitro gene silencing of RYMV genome; this can pave the way for development of RYMV resistant rice varieties in the future.
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Affiliation(s)
- Basit Jabbar
- Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan.
| | - Muhammad Shahzad Iqbal
- Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan; Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, Australia.
| | - Anicet A Batcho
- Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan.
| | - Idrees A Nasir
- Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan.
| | - Bushra Rashid
- Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan.
| | - Tayyab Husnain
- Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan.
| | - Robert J Henry
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, Australia.
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Catch Me If You Can! RNA Silencing-Based Improvement of Antiviral Plant Immunity. Viruses 2019; 11:v11070673. [PMID: 31340474 PMCID: PMC6669615 DOI: 10.3390/v11070673] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/11/2019] [Accepted: 07/17/2019] [Indexed: 12/27/2022] Open
Abstract
Viruses are obligate parasites which cause a range of severe plant diseases that affect farm productivity around the world, resulting in immense annual losses of yield. Therefore, control of viral pathogens continues to be an agronomic and scientific challenge requiring innovative and ground-breaking strategies to meet the demands of a growing world population. Over the last decade, RNA silencing has been employed to develop plants with an improved resistance to biotic stresses based on their function to provide protection from invasion by foreign nucleic acids, such as viruses. This natural phenomenon can be exploited to control agronomically relevant plant diseases. Recent evidence argues that this biotechnological method, called host-induced gene silencing, is effective against sucking insects, nematodes, and pathogenic fungi, as well as bacteria and viruses on their plant hosts. Here, we review recent studies which reveal the enormous potential that RNA-silencing strategies hold for providing an environmentally friendly mechanism to protect crop plants from viral diseases.
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12
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Xu C, Wang J, Yang J, Lei C, Hu J, Sun X. NSP2 forms viroplasms during Dendrolimus punctatus cypovirus infection. Virology 2019; 533:68-76. [PMID: 31125854 DOI: 10.1016/j.virol.2019.05.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/14/2019] [Accepted: 05/15/2019] [Indexed: 10/26/2022]
Abstract
Reoviruses are thought to replicate and assemble in special cytoplasmic structures called 'viroplasms'. However, little is known about the viroplasms of the insect reoviruses, the cypoviruses. To investigate the viroplasm of Dendrolimus punctatus cypovirus (DpCPV), all proteins encoded by the 10 genomic segments of DpCPV were expressed in Sf9 cells using the Bac-to-Bac system. The viral nonstructural protein NSP2 formed viroplasm-like dots which showed close apposition with the endoplasmic reticulum and were surrounded by intracellular membranes during transfection. Colocalization and coimmunoprecipitation assays showed that NSP2 interacts with 4 of 6 structural proteins and another 2 nonstructural proteins, while NSP1 only colocalized with VP4, and NSP3 did not colocalize with any structural protein. Immunoelectron microscopy revealed that NSP2 were nearby the endoplasmic reticulum and mitochondria, and viral particles were present in the electron-dense inclusions formed by NSP2. We proposed that NSP2 is responsible for forming the viroplasms structures of DpCPV.
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Affiliation(s)
- Congrui Xu
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, Hubei, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jia Wang
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, Hubei, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jian Yang
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, Hubei, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chengfeng Lei
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, Hubei, China
| | - Jia Hu
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, Hubei, China
| | - Xiulian Sun
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, Hubei, China.
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13
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Zhang J, Guo H, Zhang F, Chen Q, Chang M, Fang Q. NS38 is required for aquareovirus replication via interaction with viral core proteins and host eIF3A. Virology 2019; 529:216-225. [DOI: 10.1016/j.virol.2019.01.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 01/23/2019] [Accepted: 01/31/2019] [Indexed: 02/07/2023]
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14
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Arif M, Islam SU, Adnan M, Anwar M, Ali H, Wu Z. Recent progress on gene silencing/suppression by virus-derived small interfering RNAs in rice viruses especially Rice grassy stunt virus. Microb Pathog 2018; 125:210-218. [DOI: 10.1016/j.micpath.2018.09.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 09/08/2018] [Accepted: 09/11/2018] [Indexed: 12/16/2022]
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15
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Moin M, Bakshi A, Madhav MS, Kirti PB. Cas9/sgRNA-based genome editing and other reverse genetic approaches for functional genomic studies in rice. Brief Funct Genomics 2018; 17:339-351. [PMID: 29579147 DOI: 10.1093/bfgp/ely010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
One of the important and direct ways of investigating the function of a gene is to characterize the phenotypic consequences associated with loss or gain-of-function of the corresponding gene. These mutagenesis strategies have been successfully deployed in Arabidopsis, and subsequently extended to crop species including rice. Researchers have made vast advancements in the area of rice genomics and functional genomics, as it is a diploid plant with a relatively smaller genome size unlike other cereals. The advent of rice genome research and the annotation of high-quality genome sequencing along with the developments in databases and computer searches have enabled the functional characterization of unknown genes in rice. Further, with the improvements in the efficiency of regeneration and transformation protocols, it has now become feasible to produce sizable mutant populations in indica rice varieties also. In this review, various mutagenesis methods, the current status of the mutant resources, limitations and strengths of insertional mutagenesis approaches and also results obtained with suitable screens for stress tolerance in rice are discussed. In addition, targeted genome editing using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) or Cas9/single-guide RNA system and its potential applications in generating transgene-free rice plants through genome engineering as an efficient alternative to classical transgenic technology are also discussed.
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Affiliation(s)
- Mazahar Moin
- Department of Biotechnology, ICAR-Indian Institute of Rice Research (IIRR), India
- Department of Plant Sciences, University of Hyderabad, Hyderabad, India
| | - Achala Bakshi
- Department of Plant Sciences, University of Hyderabad, Hyderabad, India
| | - M S Madhav
- Department of Biotechnology, ICAR-Indian Institute of Rice Research (IIRR), India
| | - P B Kirti
- Department of Plant Sciences, University of Hyderabad, Hyderabad, India
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16
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Zotti M, Dos Santos EA, Cagliari D, Christiaens O, Taning CNT, Smagghe G. RNA interference technology in crop protection against arthropod pests, pathogens and nematodes. PEST MANAGEMENT SCIENCE 2018; 74:1239-1250. [PMID: 29194942 DOI: 10.1002/ps.4813] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/09/2017] [Accepted: 11/22/2017] [Indexed: 05/03/2023]
Abstract
Scientists have made significant progress in understanding and unraveling several aspects of double-stranded RNA (dsRNA)-mediated gene silencing during the last two decades. Now that the RNA interference (RNAi) mechanism is well understood, it is time to consider how to apply the acquired knowledge to agriculture and crop protection. Some RNAi-based products are already available for farmers and more are expected to reach the market soon. Tailor-made dsRNA as an active ingredient for biopesticide formulations is considered a raw material that can be used for diverse purposes, from pest control and bee protection against viruses to pesticide resistance management. The RNAi mechanism works at the messenger RNA (mRNA) level, exploiting a sequence-dependent mode of action, which makes it unique in potency and selectivity compared with conventional agrochemicals. Furthermore, the use of RNAi in crop protection can be achieved by employing plant-incorporated protectants through plant transformation, but also by non-transformative strategies such as the use of formulations of sprayable RNAs as direct control agents, resistance factor repressors or developmental disruptors. In this review, RNAi is presented in an agricultural context (discussing products that have been launched on the market or will soon be available), and we go beyond the classical presentation of successful examples of RNAi in pest-insect control and comprehensively explore its potential for the control of plant pathogens, nematodes and mites, and to fight against diseases and parasites in beneficial insects. Moreover, we also discuss its use as a repressor for the management of pesticide-resistant weeds and insects. Finally, this review reports on the advances in non-transformative dsRNA delivery and the production costs of dsRNA, and discusses environmental considerations. © 2017 Society of Chemical Industry.
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Affiliation(s)
- Moises Zotti
- Department of Crop Protection, Molecular Entomology, Federal University of Pelotas, Pelotas, Brazil
| | - Ericmar Avila Dos Santos
- Department of Crop Protection, Molecular Entomology, Federal University of Pelotas, Pelotas, Brazil
| | - Deise Cagliari
- Department of Crop Protection, Molecular Entomology, Federal University of Pelotas, Pelotas, Brazil
| | - Olivier Christiaens
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Clauvis Nji Tizi Taning
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Guy Smagghe
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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17
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Alburquerque N, Faize L, Burgos L. Silencing of Agrobacterium tumefaciens oncogenes ipt and iaaM induces resistance to crown gall disease in plum but not in apricot. PEST MANAGEMENT SCIENCE 2017; 73:2163-2173. [PMID: 28449201 DOI: 10.1002/ps.4600] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 04/05/2017] [Accepted: 04/22/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND In this study, two vectors with short-length chimeric transgenes were used to produce Prunus rootstocks resistant to crown gall disease through RNA-interference-mediated gene silencing of the Agrobacterium tumefaciens oncogenes ipt and iaaM. RESULTS Transgenic plum and apricot lines were produced with efficiencies of up to 7.7 and 1.1% respectively. An in vitro evaluation method allowed identification of susceptible lines and reduction in the number of lines to be evaluated in the greenhouse. Five transgenic plum lines, expressing transgene-derived small interfering RNA (siRNA) and low levels of transgene hairpin RNA (hpRNA), showed a significant reduction in the development of the disease after infection with Agrobacterium strains C58 and A281 under greenhouse conditions. However, unexpectedly, all transgenic apricot lines were gall susceptible. The infection of apricot plants with a binary vector containing only the 6b oncogene demonstrated that the expression of this gene is involved in the induction of tumours in the apricot species. CONCLUSION RNAi-mediated gene silencing can be used for inducing crown gall resistance in plum rootstocks. These could be used to graft non-genetically modified commercial fruit cultivars reducing, or eliminating, the disease symptoms. © 2017 Society of Chemical Industry.
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Affiliation(s)
- Nuria Alburquerque
- Grupo de Biotecnología de Frutales, Departamento de Mejora Vegetal, CEBAS-CSIC, Murcia, Spain
| | - Lydia Faize
- Grupo de Biotecnología de Frutales, Departamento de Mejora Vegetal, CEBAS-CSIC, Murcia, Spain
| | - Lorenzo Burgos
- Grupo de Biotecnología de Frutales, Departamento de Mejora Vegetal, CEBAS-CSIC, Murcia, Spain
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18
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Kreuze JF, Valkonen JP. Utilization of engineered resistance to viruses in crops of the developing world, with emphasis on sub-Saharan Africa. Curr Opin Virol 2017; 26:90-97. [PMID: 28800552 PMCID: PMC5669357 DOI: 10.1016/j.coviro.2017.07.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 07/24/2017] [Accepted: 07/25/2017] [Indexed: 02/08/2023]
Abstract
Viral diseases in crop plants constitute a major obstacle to food security in the developing world. Subsistence crops, including cassava, sweetpotato, potato, banana, papaya, common bean, rice and maize are often infected with RNA and/or DNA viruses that cannot be controlled with pesticides. Hence, healthy planting materials and virus-resistant cultivars are essential for high yields of good quality. However, resistance genes are not available for all viral diseases of crop plants. Therefore, virus resistance engineered in plants using modern biotechnology methods is an important addition to the crop production toolbox.
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Affiliation(s)
| | - Jari Pt Valkonen
- Department of Agricultural Sciences, University of Helsinki, FI-00014 Helsinki, Finland.
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Iqbal MS, Jabbar B, Sharif MN, Ali Q, Husnain T, Nasir IA. In silico MCMV Silencing Concludes Potential Host-Derived miRNAs in Maize. FRONTIERS IN PLANT SCIENCE 2017; 8:372. [PMID: 28400775 PMCID: PMC5368279 DOI: 10.3389/fpls.2017.00372] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 03/03/2017] [Indexed: 05/25/2023]
Abstract
Maize Chlorotic Mottle Virus (MCMV) is a deleterious pathogen which causes Maize Lethal Necrosis Disease (MLND) that results in substantial yield loss of Maize crop worldwide. The positive-sense RNA genome of MCMV (4.4 kb) encodes six proteins: P32 (32 kDa protein), RNA dependent RNA polymerases (P50 and P111), P31 (31 kDa protein), P7 (7 kDa protein), coat protein (25 kDa). P31, P7 and coat protein are encoded from sgRNA1, located at the 3'end of the genome and sgRNA2 is located at the extremity of the 3'genome end. The objective of this study is to locate the possible attachment sites of Zea mays derived miRNAs in the genome of MCMV using four diverse miRNA target prediction algorithms. In total, 321 mature miRNAs were retrieved from miRBase (miRNA database) and were tested for hybridization of MCMV genome. These algorithms considered the parameters of seed pairing, minimum free energy, target site accessibility, multiple target sites, pattern recognition and folding energy for attachment. Out of 321 miRNAs only 10 maize miRNAs are predicted for silencing of MCMV genome. The results of this study can hence act as the first step towards the development of MCMV resistant transgenic Maize plants through expression of the selected miRNAs.
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Affiliation(s)
| | - Basit Jabbar
- Center of Excellence in Molecular Biology, University of the PunjabLahore, Pakistan
- Institute of Biochemistry and Biotechnology, University of the PunjabLahore, Pakistan
| | | | - Qurban Ali
- Center of Excellence in Molecular Biology, University of the PunjabLahore, Pakistan
| | - Tayyab Husnain
- Center of Excellence in Molecular Biology, University of the PunjabLahore, Pakistan
| | - Idrees A. Nasir
- Center of Excellence in Molecular Biology, University of the PunjabLahore, Pakistan
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20
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Abstract
Rice reoviruses, transmitted by leafhopper or planthopper vectors in a persistent propagative manner, seriously threaten the stability of rice production in Asia. Understanding the mechanisms that enable viral transmission by insect vectors is a key to controlling these viral diseases. This review describes current understanding of replication cycles of rice reoviruses in vector cell lines, transmission barriers, and molecular determinants of vector competence and persistent infection. Despite recent breakthroughs, such as the discoveries of actin-based tubule motility exploited by viruses to overcome transmission barriers and mutually beneficial relationships between viruses and bacterial symbionts, there are still many gaps in our knowledge of transmission mechanisms. Advances in genome sequencing, reverse genetics systems, and molecular technologies will help to address these problems. Investigating the multiple interaction systems among the virus, insect vector, insect symbiont, and plant during natural infection in the field is a central topic for future research on rice reoviruses.
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Affiliation(s)
- Taiyun Wei
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, People's Republic of China;
| | - Yi Li
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China;
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21
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Mustafiz A, Kumari S, Karan R. Ascribing Functions to Genes: Journey Towards Genetic Improvement of Rice Via Functional Genomics. Curr Genomics 2016; 17:155-76. [PMID: 27252584 PMCID: PMC4869004 DOI: 10.2174/1389202917666160202215135] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 07/01/2015] [Accepted: 07/06/2015] [Indexed: 11/22/2022] Open
Abstract
Rice, one of the most important cereal crops for mankind, feeds more than half the world population. Rice has been heralded as a model cereal owing to its small genome size, amenability to easy transformation, high synteny to other cereal crops and availability of complete genome sequence. Moreover, sequence wealth in rice is getting more refined and precise due to resequencing efforts. This humungous resource of sequence data has confronted research fraternity with a herculean challenge as well as an excellent opportunity to functionally validate expressed as well as regulatory portions of the genome. This will not only help us in understanding the genetic basis of plant architecture and physiology but would also steer us towards developing improved cultivars. No single technique can achieve such a mammoth task. Functional genomics through its diverse tools viz. loss and gain of function mutants, multifarious omics strategies like transcriptomics, proteomics, metabolomics and phenomics provide us with the necessary handle. A paradigm shift in technological advances in functional genomics strategies has been instrumental in generating considerable amount of information w.r.t functionality of rice genome. We now have several databases and online resources for functionally validated genes but despite that we are far from reaching the desired milestone of functionally characterizing each and every rice gene. There is an urgent need for a common platform, for information already available in rice, and collaborative efforts between researchers in a concerted manner as well as healthy public-private partnership, for genetic improvement of rice crop better able to handle the pressures of climate change and exponentially increasing population.
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Affiliation(s)
- Ananda Mustafiz
- South Asian University, Akbar Bhawan, Chanakyapuri, New Delhi
| | - Sumita Kumari
- Sher-e-Kashmir University of Agriculture Sciences and Technology, Jammu 180009, India
| | - Ratna Karan
- Agronomy Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville - 32611, Florida, USA
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22
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Wang F, Li W, Zhu J, Fan F, Wang J, Zhong W, Wang MB, Liu Q, Zhu QH, Zhou T, Lan Y, Zhou Y, Yang J. Hairpin RNA Targeting Multiple Viral Genes Confers Strong Resistance to Rice Black-Streaked Dwarf Virus. Int J Mol Sci 2016; 17:ijms17050705. [PMID: 27187354 PMCID: PMC4881527 DOI: 10.3390/ijms17050705] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 01/13/2023] Open
Abstract
Rice black-streaked dwarf virus (RBSDV) belongs to the genus Fijivirus in the family of Reoviridae and causes severe yield loss in rice-producing areas in Asia. RNA silencing, as a natural defence mechanism against plant viruses, has been successfully exploited for engineering virus resistance in plants, including rice. In this study, we generated transgenic rice lines harbouring a hairpin RNA (hpRNA) construct targeting four RBSDV genes, S1, S2, S6 and S10, encoding the RNA-dependent RNA polymerase, the putative core protein, the RNA silencing suppressor and the outer capsid protein, respectively. Both field nursery and artificial inoculation assays of three generations of the transgenic lines showed that they had strong resistance to RBSDV infection. The RBSDV resistance in the segregating transgenic populations correlated perfectly with the presence of the hpRNA transgene. Furthermore, the hpRNA transgene was expressed in the highly resistant transgenic lines, giving rise to abundant levels of 21-24 nt small interfering RNA (siRNA). By small RNA deep sequencing, the RBSDV-resistant transgenic lines detected siRNAs from all four viral gene sequences in the hpRNA transgene, indicating that the whole chimeric fusion sequence can be efficiently processed by Dicer into siRNAs. Taken together, our results suggest that long hpRNA targeting multiple viral genes can be used to generate stable and durable virus resistance in rice, as well as other plant species.
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Affiliation(s)
- Fangquan Wang
- Institute of Food Crops, Jiangsu Academy of Agricultural Sciences/Nanjing Branch of Chinese National Center for Rice Improvement/Jiangsu High Quality Rice R & D Center, Nanjing 210014, China.
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
| | - Wenqi Li
- Institute of Food Crops, Jiangsu Academy of Agricultural Sciences/Nanjing Branch of Chinese National Center for Rice Improvement/Jiangsu High Quality Rice R & D Center, Nanjing 210014, China.
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
| | - Jinyan Zhu
- Institute of Food Crops, Jiangsu Academy of Agricultural Sciences/Nanjing Branch of Chinese National Center for Rice Improvement/Jiangsu High Quality Rice R & D Center, Nanjing 210014, China.
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
| | - Fangjun Fan
- Institute of Food Crops, Jiangsu Academy of Agricultural Sciences/Nanjing Branch of Chinese National Center for Rice Improvement/Jiangsu High Quality Rice R & D Center, Nanjing 210014, China.
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
| | - Jun Wang
- Institute of Food Crops, Jiangsu Academy of Agricultural Sciences/Nanjing Branch of Chinese National Center for Rice Improvement/Jiangsu High Quality Rice R & D Center, Nanjing 210014, China.
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
| | - Weigong Zhong
- Institute of Food Crops, Jiangsu Academy of Agricultural Sciences/Nanjing Branch of Chinese National Center for Rice Improvement/Jiangsu High Quality Rice R & D Center, Nanjing 210014, China.
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
| | - Ming-Bo Wang
- CSIRO Agriculture, GPO Box 1600, Canberra, ACT 2601, Australia.
| | - Qing Liu
- CSIRO Agriculture, GPO Box 1600, Canberra, ACT 2601, Australia.
| | - Qian-Hao Zhu
- CSIRO Agriculture, GPO Box 1600, Canberra, ACT 2601, Australia.
| | - Tong Zhou
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
| | - Ying Lan
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
| | - Yijun Zhou
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
| | - Jie Yang
- Institute of Food Crops, Jiangsu Academy of Agricultural Sciences/Nanjing Branch of Chinese National Center for Rice Improvement/Jiangsu High Quality Rice R & D Center, Nanjing 210014, China.
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
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23
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Nakamura S, Hondo K, Kawara T, Okazaki Y, Saito K, Kobayashi K, Yaeno T, Yamaoka N, Nishiguchi M. Conferring high-temperature tolerance to nontransgenic tomato scions using graft transmission of RNA silencing of the fatty acid desaturase gene. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:783-790. [PMID: 26132723 DOI: 10.1111/pbi.12429] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Revised: 05/22/2015] [Accepted: 05/30/2015] [Indexed: 06/04/2023]
Abstract
We investigated graft transmission of high-temperature tolerance in tomato scions to nontransgenic scions from transgenic rootstocks, where the fatty acid desaturase gene (LeFAD7) was RNA-silenced. Tomato was transformed with a plasmid carrying an inverted repeat of LeFAD7 by Agrobacterium. Several transgenic lines showed the lower amounts of LeFAD7 RNA and unsaturated fatty acids, while nontransgenic control did not, and siRNA was detected in the transgenic lines, but not in control. These lines grew under conditions of high temperature, while nontransgenic control did not. Further, the nontransgenic plants were grafted onto the silenced transgenic plants. The scions showed less of the target gene RNA, and siRNA was detected. Under high-temperature conditions, these grafted plants grew, while control grafted plants did not. Thus, it was shown that high-temperature tolerance was conferred in the nontransgenic scions after grafting onto the silenced rootstocks.
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Affiliation(s)
| | - Kana Hondo
- Faculty of Agriculture, Ehime University, Matsuyama, Japan
| | | | - Yozo Okazaki
- Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Kazuki Saito
- Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- Graduate School of Pharmaceutical Sciences, Chiba University, Inage-ku, Japan
| | | | - Takashi Yaeno
- Faculty of Agriculture, Ehime University, Matsuyama, Japan
| | - Naoto Yamaoka
- Faculty of Agriculture, Ehime University, Matsuyama, Japan
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24
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Zhang C, Wu Z, Li Y, Wu J. Biogenesis, Function, and Applications of Virus-Derived Small RNAs in Plants. Front Microbiol 2015; 6:1237. [PMID: 26617580 PMCID: PMC4637412 DOI: 10.3389/fmicb.2015.01237] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/26/2015] [Indexed: 11/13/2022] Open
Abstract
RNA silencing, an evolutionarily conserved and sequence-specific gene-inactivation system, has a pivotal role in antiviral defense in most eukaryotic organisms. In plants, a class of exogenous small RNAs (sRNAs) originating from the infecting virus called virus-derived small interfering RNAs (vsiRNAs) are predominantly responsible for RNA silencing-mediated antiviral immunity. Nowadays, the process of vsiRNA formation and the role of vsiRNAs in plant viral defense have been revealed through deep sequencing of sRNAs and diverse genetic analysis. The biogenesis of vsiRNAs is analogous to that of endogenous sRNAs, which require diverse essential components including dicer-like (DCL), argonaute (AGO), and RNA-dependent RNA polymerase (RDR) proteins. vsiRNAs trigger antiviral defense through post-transcriptional gene silencing (PTGS) or transcriptional gene silencing (TGS) of viral RNA, and they hijack the host RNA silencing system to target complementary host transcripts. Additionally, several applications that take advantage of the current knowledge of vsiRNAs research are being used, such as breeding antiviral plants through genetic engineering technology, reconstructing of viral genomes, and surveying viral ecology and populations. Here, we will provide an overview of vsiRNA pathways, with a primary focus on the advances in vsiRNA biogenesis and function, and discuss their potential applications as well as the future challenges in vsiRNAs research.
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Affiliation(s)
- Chao Zhang
- Key Laboratory of Plant Virology of Fujian Province, Institute of Plant Virology, Fujian Agriculture and Forestry University Fuzhou, China
| | - Zujian Wu
- Key Laboratory of Plant Virology of Fujian Province, Institute of Plant Virology, Fujian Agriculture and Forestry University Fuzhou, China
| | - Yi Li
- Peking-Yale Joint Center for Plant Molecular Genetics and Agrobiotechnology, The National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University Beijing, China
| | - Jianguo Wu
- Key Laboratory of Plant Virology of Fujian Province, Institute of Plant Virology, Fujian Agriculture and Forestry University Fuzhou, China ; Peking-Yale Joint Center for Plant Molecular Genetics and Agrobiotechnology, The National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University Beijing, China
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25
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Chen Q, Chen H, Jia D, Mao Q, Xei L, Wei T. Nonstructural protein Pns12 of rice dwarf virus is a principal regulator for viral replication and infection in its insect vector. Virus Res 2015. [PMID: 26200955 DOI: 10.1016/j.virusres.2015.07.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Plant reoviruses are thought to replicate and assemble within cytoplasmic structures called viroplasms. The molecular mechanisms underling the formation of the viroplasm during infection of rice dwarf virus (RDV), a plant reovirus, in its leafhopper vector cells remain poorly understood. Viral nonstructural protein Pns12 forms viroplasm-like inclusions in the absence of viral infection, suggesting that the viroplasm matrix is basically composed of Pns12. Here, we demonstrated that core capsid protein P3 and nonstructural protein Pns11 were recruited in the viroplasm by direct interaction with Pns12, whereas nonstructural protein Pns6 was recruited through interaction with Pns11. The introduction of dsRNA from Pns12 gene into cultured insect vector cells or intact insect strongly inhibited such viroplasm formation, preventing efficient viral spread in the leafhopper in vitro and in vivo. Thus, nonstructural protein Pns12 of RDV is a principal regulator for viral replication and infection in its insect vector.
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Affiliation(s)
- Qian Chen
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China
| | - Hongyan Chen
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China
| | - Dongsheng Jia
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China
| | - Qianzhuo Mao
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China
| | - Lianhui Xei
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China.
| | - Taiyun Wei
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China.
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26
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Abstract
Transgenic resistance to plant viruses is an important technology for control of plant virus infection, which has been demonstrated for many model systems, as well as for the most important plant viruses, in terms of the costs of crop losses to disease, and also for many other plant viruses infecting various fruits and vegetables. Different approaches have been used over the last 28 years to confer resistance, to ascertain whether particular genes or RNAs are more efficient at generating resistance, and to take advantage of advances in the biology of RNA interference to generate more efficient and environmentally safer, novel "resistance genes." The approaches used have been based on expression of various viral proteins (mostly capsid protein but also replicase proteins, movement proteins, and to a much lesser extent, other viral proteins), RNAs [sense RNAs (translatable or not), antisense RNAs, satellite RNAs, defective-interfering RNAs, hairpin RNAs, and artificial microRNAs], nonviral genes (nucleases, antiviral inhibitors, and plantibodies), and host-derived resistance genes (dominant resistance genes and recessive resistance genes), and various factors involved in host defense responses. This review examines the above range of approaches used, the viruses that were tested, and the host species that have been examined for resistance, in many cases describing differences in results that were obtained for various systems developed in the last 20 years. We hope this compilation of experiences will aid those who are seeking to use this technology to provide resistance in yet other crops, where nature has not provided such.
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Affiliation(s)
| | - Peter Palukaitis
- Department of Horticultural Sciences, Seoul Women's University, Seoul, Republic of Korea.
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27
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Studies of binding interactions between Dufulin and southern rice black-streaked dwarf virus P9-1. Bioorg Med Chem 2015; 23:3629-37. [DOI: 10.1016/j.bmc.2015.04.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/03/2015] [Accepted: 04/04/2015] [Indexed: 01/08/2023]
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28
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Gayen S, Samanta MK, Hossain MA, Mandal CC, Sen SK. A deletion mutant ndv200 of the Bacillus thuringiensis vip3BR insecticidal toxin gene is a prospective candidate for the next generation of genetically modified crop plants resistant to lepidopteran insect damage. PLANTA 2015; 242:269-81. [PMID: 25912191 DOI: 10.1007/s00425-015-2309-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 04/17/2015] [Indexed: 06/04/2023]
Abstract
MAIN CONCLUSION Ectopic expression of a deletion mutant ( ndv200 ) of Bacillus thuringiensis vip3BR gene in tobacco plant provided almost complete protection against major crop pests cotton boll worm ( Helicoverpa armigera ), black cut worm ( Agrotis ipsilon ) and cotton leaf worm ( Spodoptera littoralis ). Whereas vip3BR transgenic tobacco plant failed to protect themselves from these insects and showed resistance towards cotton leaf worm only. An analogous form of the Bacillus thuringiensis vip3Aa insecticidal toxin gene, named vip3BR, was identified and characterized, and exhibited similar attributes to the well-known Vip3Aa toxin. Vip3BR possessed broad-spectrum lepidopteran-specific insecticidal properties effective against most major crop pests of the Indian subcontinent. A Vip3BR toxin protein N-terminal deletion mutant, Ndv200, showed increased insecticidal potency relative to the native toxin, which conferred efficacy against four major crop pests, including cotton boll worm (Helicoverpa armigera), black cut worm (Agrotis ipsilon), cotton leaf worm (Spodoptera littoralis), and rice yellow stem borer (Scirpophaga incertulas). Ligand blot analysis indicated the Ndv200 toxin recognized the same larval midgut receptors as the native Vip3BR toxin, but differed from receptors recognized by Cry1A toxins. In the present study, we tested the prospect of the vip3BR and ndv200 toxin gene as candidate in development of insect-resistant genetically engineered crop plants by generating transgenic tobacco plant. The study revealed that the ndv200 mutant of vip3BR insecticidal toxin gene is a strong and prospective candidate for the next generation of genetically modified crop plants resistant to lepidopteran insects.
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Affiliation(s)
- Srimonta Gayen
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, 48108, USA,
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Le DT, Chu HD, Sasaya T. Creation of transgenic rice plants producing small interfering RNA of Rice tungro spherical virus. GM CROPS & FOOD 2015; 6:47-53. [PMID: 25984767 DOI: 10.1080/21645698.2015.1025188] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Rice tungro spherical virus (RTSV), also known as Rice waika virus, does not cause visible symptoms in infected rice plants. However, the virus plays a critical role in spreading Rice tungro bacilliform virus (RTBV), which is the major cause of severe symptoms of rice tungro disease. Recent studies showed that RNA interference (RNAi) can be used to develop virus-resistance transgenic rice plants. In this report, we presented simple procedures and protocols needed for the creation of transgenic rice plants capable of producing small interfering RNA specific against RTSV sequences. Notably, our study showed that 60 out of 64 individual hygromycin-resistant lines (putative transgenic lines) obtained through transformation carried transgenes designed for producing hairpin double-stranded RNA. Northern blot analyses revealed the presence of small interfering RNA of 21- to 24-mer in 46 out of 56 confirmed transgenic lines. Taken together, our study indicated that transgenic rice plants carrying an inverted repeat of 500-bp fragments encoding various proteins of RTSV can produce small interfering RNA from the hairpin RNA transcribed from that transgene. In light of recent studies with other viruses, it is possible that some of these transgenic rice lines might be resistant to RTSV.
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Affiliation(s)
- Dung Tien Le
- a Research Team for Vector-borne Diseases; National Agriculture Research Center ; Tsukuba , Ibaraki , Japan
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Yan L, Zhang J, Guo H, Yan S, Chen Q, Zhang F, Fang Q. Aquareovirus NS80 Initiates Efficient Viral Replication by Retaining Core Proteins within Replication-Associated Viral Inclusion Bodies. PLoS One 2015; 10:e0126127. [PMID: 25938226 PMCID: PMC4418822 DOI: 10.1371/journal.pone.0126127] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/30/2015] [Indexed: 11/18/2022] Open
Abstract
Viral inclusion bodies (VIBs) are specific intracellular compartments for reoviruses replication and assembly. Aquareovirus nonstructural protein NS80 has been identified to be the major constituent for forming globular VIBs in our previous study. In this study, we investigated the role of NS80 in viral structural proteins expression and viral replication. Immunofluorescence assays showed that NS80 could retain five core proteins or inner-capsid proteins (VP1-VP4 and VP6), but not outer-capsid proteins (VP5 and VP7), within VIBs in co-transfected or infected cells. Further co-immunoprecipitation analysis confirmed that NS80 could interact with each core protein respectively. In addition, we found that newly synthesized viral RNAs co-localized with VIBs. Furthermore, time-course analysis of viral structural proteins expression showed that the expression of NS80 was detected first, followed by the detection of inner shell protein VP3, and then of other inner-capsid proteins, suggesting that VIBs were essential for the formation of viral core frame or progeny virion. Moreover, knockdown of NS80 by shRNA not only inhibited the expression of aquareovirus structural proteins, but also inhibited viral infection. These results indicated that NS80-based VIBs were formed at earlier stage of infection, and NS80 was able to coordinate the expression of viral structural proteins and viral replication.
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Affiliation(s)
- Liming Yan
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jie Zhang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Hong Guo
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Shicui Yan
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Qingxiu Chen
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Fuxian Zhang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Qin Fang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
- * E-mail:
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Kamthan A, Chaudhuri A, Kamthan M, Datta A. Small RNAs in plants: recent development and application for crop improvement. FRONTIERS IN PLANT SCIENCE 2015; 6:208. [PMID: 25883599 PMCID: PMC4382981 DOI: 10.3389/fpls.2015.00208] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 03/16/2015] [Indexed: 05/19/2023]
Abstract
The phenomenon of RNA interference (RNAi) which involves sequence-specific gene regulation by small non-coding RNAs, i.e., small interfering RNA (siRNA) and microRNA (miRNA) has emerged as one of most powerful approaches for crop improvement. RNAi based on siRNA is one of the widely used tools of reverse genetics which aid in revealing gene functions in many species. This technology has been extensively applied to alter the gene expression in plants with an aim to achieve desirable traits. RNAi has been used for enhancing the crop yield and productivity by manipulating the gene involved in biomass, grain yield and enhanced shelf life of fruits and vegetables. It has also been applied for developing resistance against various biotic (bacteria, fungi, viruses, nematodes, insects) and abiotic stresses (drought, salinity, cold, etc.). Nutritional improvements of crops have also been achieved by enriching the crops with essential amino acids, fatty acids, antioxidants and other nutrients beneficial for human health or by reducing allergens or anti-nutrients. microRNAs are key regulators of important plant processes like growth, development, and response to various stresses. In spite of similarity in size (20-24 nt), miRNA differ from siRNA in precursor structures, pathway of biogenesis, and modes of action. This review also highlights the miRNA based genetic modification technology where various miRNAs/artificial miRNAs and their targets can be utilized for improving several desirable plant traits. microRNA based strategies are much efficient than siRNA-based RNAi strategies due to its specificity and less undesirable off target effects. As per the FDA guidelines, small RNA (sRNA) based transgenics are much safer for consumption than those over-expressing proteins. This review thereby summarizes the emerging advances and achievement in the field of sRNAs and its application for crop improvement.
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Affiliation(s)
- Ayushi Kamthan
- National Institute of Plant Genome ResearchNew Delhi, India
| | | | - Mohan Kamthan
- Indian Institute of Toxicology ResearchLucknow, India
| | - Asis Datta
- National Institute of Plant Genome ResearchNew Delhi, India
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Nandety RS, Kuo YW, Nouri S, Falk BW. Emerging strategies for RNA interference (RNAi) applications in insects. Bioengineered 2014; 6:8-19. [PMID: 25424593 PMCID: PMC4601220 DOI: 10.4161/21655979.2014.979701] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 09/29/2014] [Accepted: 10/14/2014] [Indexed: 11/19/2022] Open
Abstract
RNA interference (RNAi) in insects is a gene regulatory process that also plays a vital role in the maintenance and in the regulation of host defenses against invading viruses. Small RNAs determine the specificity of the RNAi through precise recognition of their targets. These small RNAs in insects comprise small interfering RNAs (siRNAs), micro RNAs (miRNAs) and Piwi interacting RNAs (piRNAs) of various lengths. In this review, we have explored different forms of the RNAi inducers that are presently in use, and their applications for an effective and efficient fundamental and practical RNAi research with insects. Further, we reviewed trends in next generation sequencing (NGS) technologies and their importance for insect RNAi, including the identification of novel insect targets as well as insect viruses. Here we also describe a rapidly emerging trend of using plant viruses to deliver the RNAi inducer molecules into insects for an efficient RNAi response.
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Affiliation(s)
| | - Yen-Wen Kuo
- Department of Plant Pathology; University of California; Davis, CA USA
| | - Shahideh Nouri
- Department of Plant Pathology; University of California; Davis, CA USA
| | - Bryce W Falk
- Department of Plant Pathology; University of California; Davis, CA USA
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Zhang ZJ. Artificial trans-acting small interfering RNA: a tool for plant biology study and crop improvements. PLANTA 2014; 239:1139-46. [PMID: 24643516 DOI: 10.1007/s00425-014-2054-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 03/05/2014] [Indexed: 05/25/2023]
Abstract
Completion of whole genome sequencing in many plant species including economically important crop species not only opens up new opportunities but also imposes challenges for plant science research community. Functional validation and utilization of these enormous DNA sequences necessitate new or improved tools with high accuracy and efficiency. Of various tools, small RNA-mediated gene silencing platform plays an important and unique role in functional verification of plant genes and trait improvements. Artificial trans-acting small interfering RNA (atasiRNA) has emerged as a potent and specific gene silencing platform which overcomes major limitations of other small RNA silencing approaches including double-stranded RNA, artificial microRNA (amiRNA), and microRNA-induced gene silencing. To best utilize atasiRNA platform, it is essential to be able to test candidate atasiRNAs efficiently through either in vivo or in vitro validation approach. Very recently, a breakthrough has been made in developing a new method for in vitro screen of amiRNA candidates, named "epitope-tagged protein-based amiRNA screens". Such a screen can be readily employed to validate atasiRNA candidates and thus accelerate the deployment of atasiRNA technology. Therefore, atasiRNA as an emerging tool shall accelerate both plant biology study and crop genetic improvements including trait stacking.
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Affiliation(s)
- Zhanyuan J Zhang
- Plant Transformation Core Facility, Division of Plant Sciences, University of Missouri, 1-33 Agriculture Building, Columbia, MO, 65211, USA,
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Saurabh S, Vidyarthi AS, Prasad D. RNA interference: concept to reality in crop improvement. PLANTA 2014; 239:543-64. [PMID: 24402564 DOI: 10.1007/s00425-013-2019-5] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Accepted: 12/21/2013] [Indexed: 05/18/2023]
Abstract
The phenomenon of RNA interference (RNAi) is involved in sequence-specific gene regulation driven by the introduction of dsRNA resulting in inhibition of translation or transcriptional repression. Since the discovery of RNAi and its regulatory potentials, it has become evident that RNAi has immense potential in opening a new vista for crop improvement. RNAi technology is precise, efficient, stable and better than antisense technology. It has been employed successfully to alter the gene expression in plants for better quality traits. The impact of RNAi to improve the crop plants has proved to be a novel approach in combating the biotic and abiotic stresses and the nutritional improvement in terms of bio-fortification and bio-elimination. It has been employed successfully to bring about modifications of several desired traits in different plants. These modifications include nutritional improvements, reduced content of food allergens and toxic compounds, enhanced defence against biotic and abiotic stresses, alteration in morphology, crafting male sterility, enhanced secondary metabolite synthesis and seedless plant varieties. However, crop plants developed by RNAi strategy may create biosafety risks. So, there is a need for risk assessment of GM crops in order to make RNAi a better tool to develop crops with biosafety measures. This article is an attempt to review the RNAi, its biochemistry, and the achievements attributed to the application of RNAi in crop improvement.
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Affiliation(s)
- Satyajit Saurabh
- Department of Biotechnology, Birla Institute of Technology, Mesra, Ranchi, 835125, India
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35
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Sasaya T, Nakazono-Nagaoka E, Saika H, Aoki H, Hiraguri A, Netsu O, Uehara-Ichiki T, Onuki M, Toki S, Saito K, Yatou O. Transgenic strategies to confer resistance against viruses in rice plants. Front Microbiol 2014; 4:409. [PMID: 24454308 PMCID: PMC3888933 DOI: 10.3389/fmicb.2013.00409] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 12/12/2013] [Indexed: 12/02/2022] Open
Abstract
Rice (Oryza sativa L.) is cultivated in more than 100 countries and supports nearly half of the world's population. Developing efficient methods to control rice viruses is thus an urgent necessity because viruses cause serious losses in rice yield. Most rice viruses are transmitted by insect vectors, notably planthoppers and leafhoppers. Viruliferous insect vectors can disperse their viruses over relatively long distances, and eradication of the viruses is very difficult once they become widespread. Exploitation of natural genetic sources of resistance is one of the most effective approaches to protect crops from virus infection; however, only a few naturally occurring rice genes confer resistance against rice viruses. Many investigators are using genetic engineering of rice plants as a potential strategy to control viral diseases. Using viral genes to confer pathogen-derived resistance against crops is a well-established procedure, and the expression of various viral gene products has proved to be effective in preventing or reducing infection by various plant viruses since the 1990s. RNA interference (RNAi), also known as RNA silencing, is one of the most efficient methods to confer resistance against plant viruses on their respective crops. In this article, we review the recent progress, mainly conducted by our research group, in transgenic strategies to confer resistance against tenuiviruses and reoviruses in rice plants. Our findings also illustrate that not all RNAi constructs against viral RNAs are equally effective in preventing virus infection and that it is important to identify the viral "Achilles' heel" gene to target for RNAi attack when engineering plants.
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Affiliation(s)
- Takahide Sasaya
- NARO Kyushu-Okinawa Agricultural Research CenterKoshi, Kumamoto, Japan
| | | | - Hiroaki Saika
- National Institute of Agrobiological SciencesTsukuba, Ibaraki, Japan
| | - Hideyuki Aoki
- Hokuriku Research Center, NARO Agricultural Research CenterJoetsu, Niigata, Japan
| | - Akihiro Hiraguri
- Graduate School of Agricultural and Life Sciences, The University of Tokyo BunkyoTokyo, Japan
| | - Osamu Netsu
- Graduate School of Agricultural and Life Sciences, The University of Tokyo BunkyoTokyo, Japan
| | | | - Masatoshi Onuki
- NARO Kyushu-Okinawa Agricultural Research CenterKoshi, Kumamoto, Japan
| | - Seichi Toki
- National Institute of Agrobiological SciencesTsukuba, Ibaraki, Japan
| | - Koji Saito
- Hokuriku Research Center, NARO Agricultural Research CenterJoetsu, Niigata, Japan
| | - Osamu Yatou
- Hokuriku Research Center, NARO Agricultural Research CenterJoetsu, Niigata, Japan
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Abstract
The family Reoviridae separates two subfamilies and consists of 15 genera. Fourteen viruses in three genera (Phytoreovirus, Oryzavirus, and Fijivirus) infect plants. The outbreaks of the plant-infecting reoviruses cause sometime the serious yield loss of rice and maize, and are a menace to safe and efficient food production in the Southeast Asia. The plant-infecting reoviruses are double-shelled icosahedral particles, from 50 to 80nm in diameter, and include from 10 to 12 segmented double-stranded genomic RNAs depending on the viruses. These viruses are transmitted in a persistent manner by the vector insects and replicated in both plants and in their vectors. This review provides a brief overview of the plant-infecting reoviruses and their recent research progresses including the strategy for viral controls using transgenic rice plants.
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Affiliation(s)
- Takahide Sasaya
- Agro-Environment Research Division,NARO Kyushu Okinawa Agricultural Research Center
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37
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Miyazaki N, Akita F, Nakagawa A, Murata K, Omura T, Iwasaki K. Cryo-electron tomography: moving towards revealing the viral life cycle of Rice dwarf virus. JOURNAL OF SYNCHROTRON RADIATION 2013; 20:826-8. [PMID: 24121321 PMCID: PMC3795537 DOI: 10.1107/s090904951302219x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 08/07/2013] [Indexed: 06/02/2023]
Abstract
It is well known that viruses utilize the host cellular systems for their infection and replication processes. However, the molecular mechanisms underlying these processes are poorly understood for most viruses. To understand these molecular mechanisms, it is essential to observe the viral and virus-related structures and analyse their molecular interactions within a cellular context. Cryo-electron microscopy and tomography offer the potential to observe macromolecular structures and to analyse their molecular interactions within the cell. Here, using cryo-electron microscopy and tomography, the structures of Rice dwarf virus are reported within fully hydrated insect vector cells grown on electron microscopy grids towards revealing the viral infection and replication mechanisms.
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Affiliation(s)
- Naoyuki Miyazaki
- National Institute for Physiological Sciences, 38 Nishigonaka, Myodaiji, Okazaki, Aichi 444-8585, Japan
- Institute for Protein Research, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Fusamichi Akita
- National Agricultural Research Center, 3-1-1 Kannondai, Tsukuba, Ibaraki 305-8666, Japan
- Division of Bioscience, Graduate School of Natural Science and Technology, Faculty of Science, Okayama University, Okayama 700-8530, Japan
| | - Atsushi Nakagawa
- Institute for Protein Research, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kazuyoshi Murata
- National Institute for Physiological Sciences, 38 Nishigonaka, Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Toshihiro Omura
- National Agricultural Research Center, 3-1-1 Kannondai, Tsukuba, Ibaraki 305-8666, Japan
| | - Kenji Iwasaki
- Institute for Protein Research, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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Miyazaki N, Nakagawa A, Iwasaki K. Life cycle of phytoreoviruses visualized by electron microscopy and tomography. Front Microbiol 2013; 4:306. [PMID: 24137159 PMCID: PMC3797527 DOI: 10.3389/fmicb.2013.00306] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 09/24/2013] [Indexed: 12/30/2022] Open
Abstract
Rice dwarf virus and Rice gall dwarf virus, members of the genus Phytoreovirus in the family Reoviridae,are known as agents of rice disease, because their spread results in substantial economic damage in many Asian countries. These viruses are transmitted via insect vectors, and they multiply both in the plants and in the insect vectors. Structural information about the viruses and their interactions with cellular components in the life cycle are essential for understanding viral infection and replication mechanisms. The life cycle of the viruses involves various cellular events such as cell entry, synthesis of viral genome and proteins, assembly of viral components, viral egress from infected cells, and intra- and intercellular transports. This review focuses on the major events underlying the life cycle of phytoreoviruses, which has been visualized by various electron microscopy (EM) imaging techniques, including cryo-electron microscopy and tomography, and demonstrates the advantage of the advanced EM imaging techniques to investigate the viral infection and replication mechanisms.
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Affiliation(s)
- Naoyuki Miyazaki
- Institute for Protein Research, Osaka University Osaka, Japan ; National Institute for Physiological Sciences Okazaki, Japan
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Jiang Y, Sun L, Jiang M, Li K, Song Y, Zhu C. Production of marker-free and RSV-resistant transgenic rice using a twin T-DNA system and RNAi. J Biosci 2013; 38:573-81. [PMID: 23938389 DOI: 10.1007/s12038-013-9349-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A twin T-DNA system is a convenient strategy for creating selectable marker-free transgenic plants. The standard transformation plasmid, pCAMBIA 1300, was modified into a binary vector consisting of two separate T-DNAs, one of which contained the hygromycin phosphotransferase (hpt) marker gene. Using this binary vector, we constructed two vectors that expressed inverted-repeat (IR) structures targeting the rice stripe virus (RSV) coat protein (CP) gene and the special-disease protein (SP) gene. Transgenic rice lines were obtained via Agrobacterium-mediated transformation. Seven independent clones harbouring both the hpt marker gene and the target genes (RSV CP or SP) were obtained in the primary transformants of pDTRSVCP and pDTRSVSP, respectively. The segregation frequencies of the target gene and the marker gene in the T1 plants were 8.72 percent for pDTRSVCP and 12.33 percent for pDTRSVSP. Two of the pDTRSVCP lines and three pDTRSVSP lines harbouring the homozygous target gene, but not the hpt gene, were strongly resistant to RSV. A molecular analysis of the resistant transgenic plants confirmed the stable integration and expression of the target genes. The resistant transgenic plants displayed lower levels of the transgene transcripts and specific small interfering RNAs, suggesting that RNAi induced the viral resistance.
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Affiliation(s)
- Yayuan Jiang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, P.R. China, 271018
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Hiraguri A, Ueki S, Kondo H, Nomiyama K, Shimizu T, Ichiki-Uehara T, Omura T, Sasaki N, Nyunoya H, Sasaya T. Identification of a movement protein of Mirafiori lettuce big-vein ophiovirus. J Gen Virol 2013; 94:1145-1150. [PMID: 23364193 DOI: 10.1099/vir.0.050005-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Mirafiori lettuce big-vein virus (MiLBVV) is a member of the genus Ophiovirus, which is a segmented negative-stranded RNA virus. In microprojectile bombardment experiments to identify a movement protein (MP) gene of ophioviruses that can trans-complement intercellular movement of an MP-deficient heterologous virus, a plasmid containing an infectious clone of a tomato mosaic virus (ToMV) derivative expressing the GFP was co-bombarded with plasmids containing one of three genes from MiLBVV RNAs 1, 2 and 4 onto Nicotiana benthamiana. Intercellular movement of the movement-defective ToMV was restored by co-expression of the 55 kDa protein gene, but not with the two other genes. Transient expression in epidermal cells of N. benthamiana and onion showed that the 55 kDa protein with GFP was localized on the plasmodesmata. The 55 kDa protein encoded in the MiLBVV RNA2 can function as an MP of the virus. This report is the first to describe an ophiovirus MP.
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Affiliation(s)
- Akihiro Hiraguri
- National Agricultural Research Center, 31-1 Kannondai, Tsukuba, Ibaraki 305-8666, Japan
| | - Shoko Ueki
- Institute of Plant Science and Resources, Okayama University, 2-20-1, Chuo, Kurashiki, Okayama, 710-0046, Japan
| | - Hideki Kondo
- Institute of Plant Science and Resources, Okayama University, 2-20-1, Chuo, Kurashiki, Okayama, 710-0046, Japan
| | - Koji Nomiyama
- NARO Western Region Agricultural Research Center (NARO/WARC), 6-12-1 Nishifukatsu-cho, Fukuyama, Hiroshima, Japan
| | - Takumi Shimizu
- National Agricultural Research Center, 31-1 Kannondai, Tsukuba, Ibaraki 305-8666, Japan
| | - Tamaki Ichiki-Uehara
- National Agricultural Research Center, 31-1 Kannondai, Tsukuba, Ibaraki 305-8666, Japan
| | - Toshihiro Omura
- National Agricultural Research Center, 31-1 Kannondai, Tsukuba, Ibaraki 305-8666, Japan
| | - Nobumitsu Sasaki
- Gene Research Center, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Hiroshi Nyunoya
- Gene Research Center, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Takahide Sasaya
- National Agricultural Research Center, 31-1 Kannondai, Tsukuba, Ibaraki 305-8666, Japan
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Knorr E, Bingsohn L, Kanost MR, Vilcinskas A. Tribolium castaneum as a model for high-throughput RNAi screening. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2013; 136:163-78. [PMID: 23748349 DOI: 10.1007/10_2013_208] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Coleopteran insects are a highly diverse and successful order, and many beetle species are significant agricultural pests. New biorational strategies for managing populations of beetles and other insect species are needed as pests develop resistance to chemical insecticides and Bt toxins. There is now an opportunity to use genome sequence data to identify genes that are essential for insect growth, development, or survival as new targets for designing control technology. This goal requires a method for high-throughput in vivo screening of thousands of genes to identify candidate genes that, when their expression is disrupted, have a phenotype that may be useful in insect pest control. Tribolium castaneum, the red flour beetle, is a model organism that offers considerable advantages for such screening, including ease of rearing in large numbers, a sequenced genome, and a strong, systemic RNAi response for specific depletion of gene transcripts. The RNAi effect in T. castaneum can be elicited in any tissue and any stage by the injection of dsRNA into the hemocoel, and injection of dsRNA into adult females can even be used to identify phenotypes in offspring. A pilot RNAi screen (iBeetle) is underway. Several T. castaneum genes with promising RNAi phenotypes for further development as mechanisms for plant protection have been identified. These include heat shock protein 90, chitin synthase, the segmentation gene hairy, and a matrix metalloprotease. Candidate genes identified in T. castaneum screens can then be tested in agricultural pest species (in which screening is not feasible), to evaluate their effectiveness for use in potential plant-based RNAi control strategies. Delivery of dsRNA expressed by genetically modified crops to the midgut of phytophagous insects is under investigation as a new tool for very specific protection of plants from insect pest species. The T. castaneum screening platform offers a system for discovery of candidate genes with high potential benefit.
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Affiliation(s)
- Eileen Knorr
- Institute of Phytopathology and Applied Zoology, Justus-Liebig-University of Giessen, Heinrich-Buff-Ring 26-32, 39592, Giessen, Germany
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Chen Q, Chen H, Mao Q, Liu Q, Shimizu T, Uehara-Ichiki T, Wu Z, Xie L, Omura T, Wei T. Tubular structure induced by a plant virus facilitates viral spread in its vector insect. PLoS Pathog 2012; 8:e1003032. [PMID: 23166500 PMCID: PMC3499585 DOI: 10.1371/journal.ppat.1003032] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 10/02/2012] [Indexed: 01/25/2023] Open
Abstract
Rice dwarf virus (RDV) replicates in and is transmitted by a leafhopper vector in a persistent-propagative manner. Previous cytopathologic and genetic data revealed that tubular structures, constructed by the nonstructural viral protein Pns10, contain viral particles and are directly involved in the intercellular spread of RDV among cultured leafhopper cells. Here, we demonstrated that RDV exploited these virus-containing tubules to move along actin-based microvilli of the epithelial cells and muscle fibers of visceral muscle tissues in the alimentary canal, facilitating the spread of virus in the body of its insect vector leafhoppers. In cultured leafhopper cells, the knockdown of Pns10 expression due to RNA interference (RNAi) induced by synthesized dsRNA from Pns10 gene strongly inhibited tubule formation and prevented the spread of virus among insect vector cells. RNAi induced after ingestion of dsRNA from Pns10 gene strongly inhibited formation of tubules, preventing intercellular spread and transmission of the virus by the leafhopper. All these results, for the first time, show that a persistent-propagative virus exploits virus-containing tubules composed of a nonstructural viral protein to traffic along actin-based cellular protrusions, facilitating the intercellular spread of the virus in the vector insect. The RNAi strategy and the insect vector cell culture provide useful tools to investigate the molecular mechanisms enabling efficient transmission of persistent-propagative plant viruses by vector insects.
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Affiliation(s)
- Qian Chen
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
| | - Hongyan Chen
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
| | - Qianzhuo Mao
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
| | - Qifei Liu
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
| | - Takumi Shimizu
- National Agricultural Research Center, Tsukuba, Ibaraki, Japan
| | | | - Zujian Wu
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
| | - Lianhui Xie
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
| | - Toshihiro Omura
- National Agricultural Research Center, Tsukuba, Ibaraki, Japan
- * E-mail: (TO) (TO); (TW) (TW)
| | - Taiyun Wei
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- National Agricultural Research Center, Tsukuba, Ibaraki, Japan
- * E-mail: (TO) (TO); (TW) (TW)
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43
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Jia D, Guo N, Chen H, Akita F, Xie L, Omura T, Wei T. Assembly of the viroplasm by viral non-structural protein Pns10 is essential for persistent infection of rice ragged stunt virus in its insect vector. J Gen Virol 2012; 93:2299-2309. [PMID: 22837415 DOI: 10.1099/vir.0.042424-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rice ragged stunt virus (RRSV), an oryzavirus, is transmitted by brown planthopper in a persistent propagative manner. In this study, sequential infection of RRSV in the internal organs of its insect vector after ingestion of virus was investigated by immunofluorescence microscopy. RRSV was first detected in the epithelial cells of the midgut, from where it proceeded to the visceral muscles surrounding the midgut, then throughout the visceral muscles of the midgut and hindgut, and finally into the salivary glands. Viroplasms, the sites of virus replication and assembly of progeny virions, were formed in the midgut epithelium, visceral muscles and salivary glands of infected insects and contained the non-structural protein Pns10 of RRSV, which appeared to be the major constituent of the viroplasms. Viroplasm-like structures formed in non-host insect cells following expression of Pns10 in a baculovirus system, suggesting that the viroplasms observed in RRSV-infected cells were composed basically of Pns10. RNA interference induced by ingestion of dsRNA from the Pns10 gene of RRSV strongly inhibited such viroplasm formation, preventing efficient virus infection and spread in its insect vectors. These results show that Pns10 of RRSV is essential for viroplasm formation and virus replication in the vector insect.
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Affiliation(s)
- Dongsheng Jia
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China
| | - Nianmei Guo
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China
| | - Hongyan Chen
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China
| | - Fusamichi Akita
- National Agricultural Research Center, 3-1-1 Kannondai, Tsukuba, Ibaraki 305-8666, Japan
| | - Lianhui Xie
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China
| | - Toshihiro Omura
- National Agricultural Research Center, 3-1-1 Kannondai, Tsukuba, Ibaraki 305-8666, Japan
| | - Taiyun Wei
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China
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Tanaka T, Eusebio-Cope A, Sun L, Suzuki N. Mycoreovirus genome alterations: similarities to and differences from rearrangements reported for other reoviruses. Front Microbiol 2012; 3:186. [PMID: 22675320 PMCID: PMC3365852 DOI: 10.3389/fmicb.2012.00186] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 05/04/2012] [Indexed: 11/13/2022] Open
Abstract
The family Reoviridae is one of the largest virus families with genomes composed of 9-12 double-stranded RNA segments. It includes members infecting organisms from protists to humans. It is well known that reovirus genomes are prone to various types of genome alterations including intragenic rearrangement and reassortment under laboratory and natural conditions. Recently distinct genetic alterations were reported for members of the genus Mycoreovirus, Mycoreovirus 1 (MyRV1), and MyRV3 with 11 (S1-S11) and 12 genome segments (S1-S12), respectively. While MyRV3 S8 is lost during subculturing of infected host fungal strains, MyRV1 rearrangements undergo alterations spontaneously and inducibly. The inducible MyRV1 rearrangements are different from any other previous examples of reovirus rearrangements in their dependence on an unrelated virus factor, a multifunctional protein, p29, encoded by a distinct virus Cryphonectria parasitica hypovirus 1 (CHV1). A total of 5 MyRV1 variants with genome rearranged segments (S1-S3, S6 and S10) are generated in the background of a single viral strain in the presence of CHV1 p29 supplied either transgenically or by coinfection. MyRV1 S4 and S10 are rearranged, albeit very infrequently, in a CHV1 p29 independent fashion. A variant of MyRV1 with substantial deletions in both S4 and S10, generated through a combined reassortment and rearrangement approach, shows comparable replication levels to the wild-type MyRV1. In vivo and in vitro interactions of CHV1 p29 and MyRV1 VP9 are implicated in the induction of MyRV1 rearrangements. However, the mechanism underlying p29-mediated rearrangements remains largely unknown. MyRV1 S4 rearrangements spontaneously occurred independently of CHV1 p29. In the absence of reverse genetics systems for mycoreoviruses, molecular and biological characterization of these MyRV1 and MyRV3 variants contribute to functional analyses of the protein products encoded by those rearranged segments.
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Affiliation(s)
- Toru Tanaka
- Agrivirology Laboratory, Institute of Plant Science and Bioresources, Okayama University Kurashiki, Okayama, Japan
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45
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Soler N, Plomer M, Fagoaga C, Moreno P, Navarro L, Flores R, Peña L. Transformation of Mexican lime with an intron-hairpin construct expressing untranslatable versions of the genes coding for the three silencing suppressors of Citrus tristeza virus confers complete resistance to the virus. PLANT BIOTECHNOLOGY JOURNAL 2012; 10:597-608. [PMID: 22405601 DOI: 10.1111/j.1467-7652.2012.00691.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Citrus tristeza virus (CTV), the causal agent of the most devastating viral disease of citrus, has evolved three silencing suppressor proteins acting at intra- (p23 and p20) and/or intercellular level (p20 and p25) to overcome host antiviral defence. Previously, we showed that Mexican lime transformed with an intron-hairpin construct including part of the gene p23 and the adjacent 3' untranslated region displays partial resistance to CTV, with a fraction of the propagations from some transgenic lines remaining uninfected. Here, we transformed Mexican lime with an intron-hairpin vector carrying full-length, untranslatable versions of the genes p25, p20 and p23 from CTV strain T36 to silence the expression of these critical genes in CTV-infected cells. Three transgenic lines presented complete resistance to viral infection, with all their propagations remaining symptomless and virus-free after graft inoculation with CTV-T36, either in the nontransgenic rootstock or in the transgenic scion. Accumulation of transgene-derived siRNAs was necessary but not sufficient for CTV resistance. Inoculation with a divergent CTV strain led to partially breaking the resistance, thus showing the role of sequence identity in the underlying mechanism. Our results are a step forward to developing transgenic resistance to CTV and also show that targeting simultaneously by RNA interference (RNAi) the three viral silencing suppressors appears critical for this purpose, although the involvement of concurrent RNAi mechanisms cannot be excluded.
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Affiliation(s)
- Nuria Soler
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias-IVIA, Valencia, Spain
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Jia D, Chen H, Zheng A, Chen Q, Liu Q, Xie L, Wu Z, Wei T. Development of an insect vector cell culture and RNA interference system to investigate the functional role of fijivirus replication protein. J Virol 2012; 86:5800-7. [PMID: 22398296 PMCID: PMC3347266 DOI: 10.1128/jvi.07121-11] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 02/27/2012] [Indexed: 01/04/2023] Open
Abstract
An in vitro culture system of primary cells from white-backed planthopper, an insect vector of Southern rice black-streaked dwarf virus (SRBSDV), a fijivirus, was established to study replication of the virus. Viroplasms, putative sites of viral replication, contained the nonstructural viral protein P9-1, viral RNA, outer-capsid proteins, and viral particles in virus-infected cultured insect vector cells, as revealed by transmission electron and confocal microscopy. Formation of viroplasm-like structures in non-host insect cells upon expression of P9-1 suggested that the matrix of viroplasms observed in virus-infected cells was composed basically of P9-1. In cultured insect vector cells, knockdown of P9-1 expression due to RNA interference (RNAi) induced by synthesized double-stranded RNA (dsRNA) from the P9-1 gene strongly inhibited viroplasm formation and viral infection. RNAi induced by ingestion of dsRNA strongly abolished viroplasm formation, preventing efficient viral spread in the body of intact vector insects. All these results demonstrated that P9-1 was essential for viroplasm formation and viral replication. This system, combining insect vector cell culture and RNA interference, can further advance our understanding of the biological activities of fijivirus replication proteins.
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Affiliation(s)
- Dongsheng Jia
- Institute of Plant Virology, Fujian Province Key Laboratory of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, People's Republic of China
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Zhou Y, Yuan Y, Yuan F, Wang M, Zhong H, Gu M, Liang G. RNAi-directed down-regulation of RSV results in increased resistance in rice (Oryza sativa L.). Biotechnol Lett 2012; 34:965-72. [PMID: 22261864 DOI: 10.1007/s10529-012-0848-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2011] [Accepted: 12/23/2011] [Indexed: 10/14/2022]
Abstract
Rice stripe disease (RSD), caused by rice stripe virus (RSV), is a serious disease in temperate rice-growing areas. We have created an RNAi construct containing coat protein gene (CP) and disease specific protein gene (SP) sequences from RSV. The RNAi construct was transformed into two susceptible japonica varieties, Suyunuo and Guanglingxiangjing, to develop resistance against RSD. The homozygous progeny of rice plants in the T(5) and T(7) generations containing RNAi constructs, after self-fertilization were strongly resistant to viral infection. RT-PCR indicated that viral replication of SP and CP in the transgenic plants was significantly inhibited. There were no obvious morphological or developmental differences between the transgenic and wild-type plants from seedling stage to maturity. The excellent agronomic traits of these two varieties, such as high yield and good quality were maintained. Suppression of virus genes using RNAi is therefore a practical and effective strategy for controlling viral infection in crops.
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Affiliation(s)
- Yong Zhou
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of Ministry of Education, Yangzhou University, Yangzhou, 225009, China
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48
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Assembly of Large Icosahedral Double-Stranded RNA Viruses. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 726:379-402. [DOI: 10.1007/978-1-4614-0980-9_17] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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49
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Hairpin RNA derived from the gene for Pns9, a viroplasm matrix protein of Rice gall dwarf virus, confers strong resistance to virus infection in transgenic rice plants. J Biotechnol 2011; 157:421-7. [PMID: 22212819 DOI: 10.1016/j.jbiotec.2011.12.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 12/07/2011] [Accepted: 12/20/2011] [Indexed: 11/23/2022]
Abstract
The nonstructural Pns9 protein of Rice gall dwarf virus (RGDV) accumulates in viroplasm inclusions, which are structures that appear to play an important role in viral morphogenesis and are commonly found in host cells infected by viruses in the family Reoviridae. An RNA interference construct was designed to target the gene for Pns9 of RGDV, namely Trigger_G9. The resultant transgenic plants accumulated short interfering RNAs specific for the construct. All progenies from self-fertilized transgenic plants had strong and heritable resistance to RGDV infection and did not allow the propagation of RGDV. By contrast, our transgenic plants remained susceptible to Rice dwarf virus, another phytoreovirus. There were no significant changes in the morphology of our transgenic plants compared with non-inoculated wild-type rice plants, suggesting that genes critical for the growth of rice plants were unaffected. Our results demonstrate that the resistance to RGDV of our transgenic rice plants is not due to resistance to the vector insects but to specific inhibition of RGDV replication and that the designed trigger sequence is functioning normally. Thus, our strategy to target a gene for viroplasm matrix protein should be applicable to plant viruses that belong to the family Reoviridae.
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50
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Crystallographic analysis reveals octamerization of viroplasm matrix protein P9-1 of Rice black streaked dwarf virus. J Virol 2011; 86:746-56. [PMID: 22072761 DOI: 10.1128/jvi.00826-11] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The P9-1 protein of Rice black streaked dwarf virus accumulates in viroplasm inclusions, which are structures that appear to play an important role in viral morphogenesis and are commonly found in viruses in the family Reoviridae. Crystallographic analysis of P9-1 revealed structural features that allow the protein to form dimers via hydrophobic interactions. Each dimer has carboxy-terminal regions, resembling arms, that extend to neighboring dimers, thereby uniting sets of four dimers via lateral hydrophobic interactions, to yield cylindrical octamers. The importance of these regions for the formation of viroplasm-like inclusions was confirmed by the absence of such inclusions when P9-1 was expressed without its carboxy-terminal arm. The octamers are vertically elongated cylinders resembling the structures formed by NSP2 of rotavirus, even though there are no significant similarities between the respective primary and secondary structures of the two proteins. Our results suggest that an octameric structure with an internal pore might be important for the functioning of the respective proteins in the events that occur in the viroplasm, which might include viral morphogenesis.
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