1
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Nielsen CPS, Arribas-Hernández L, Han L, Reichel M, Woessmann J, Daucke R, Bressendorff S, López-Márquez D, Andersen SU, Pumplin N, Schoof EM, Brodersen P. Evidence for an RNAi-independent role of Arabidopsis DICER-LIKE2 in growth inhibition and basal antiviral resistance. THE PLANT CELL 2024; 36:2289-2309. [PMID: 38466226 PMCID: PMC11132882 DOI: 10.1093/plcell/koae067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 12/13/2023] [Accepted: 01/28/2024] [Indexed: 03/12/2024]
Abstract
Flowering plant genomes encode four or five DICER-LIKE (DCL) enzymes that produce small interfering RNAs (siRNAs) and microRNAs, which function in RNA interference (RNAi). Different RNAi pathways in plants effect transposon silencing, antiviral defense, and endogenous gene regulation. DCL2 acts genetically redundantly with DCL4 to confer basal antiviral defense. However, DCL2 may also counteract DCL4 since knockout of DCL4 causes growth defects that are suppressed by DCL2 inactivation. Current models maintain that RNAi via DCL2-dependent siRNAs is the biochemical basis of both effects. Here, we report that DCL2-mediated antiviral resistance and growth defects cannot be explained by the silencing effects of DCL2-dependent siRNAs. Both functions are defective in genetic backgrounds that maintain high levels of DCL2-dependent siRNAs, either with specific point mutations in DCL2 or with reduced DCL2 dosage because of heterozygosity for dcl2 knockout alleles. Intriguingly, all DCL2 functions require its catalytic activity, and the penetrance of DCL2-dependent growth phenotypes in dcl4 mutants correlates with DCL2 protein levels but not with levels of major DCL2-dependent siRNAs. We discuss this requirement and correlation with catalytic activity but not with resulting siRNAs, in light of other findings that reveal a DCL2 function in innate immunity activation triggered by cytoplasmic double-stranded RNA.
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Affiliation(s)
- Carsten Poul Skou Nielsen
- Copenhagen Plant Science Center, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Laura Arribas-Hernández
- Copenhagen Plant Science Center, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Lijuan Han
- Copenhagen Plant Science Center, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Marlene Reichel
- Copenhagen Plant Science Center, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Jakob Woessmann
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Bygningstorvet, DK-2800 Lyngby, Denmark
| | - Rune Daucke
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Bygningstorvet, DK-2800 Lyngby, Denmark
| | - Simon Bressendorff
- Copenhagen Plant Science Center, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Diego López-Márquez
- Copenhagen Plant Science Center, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Stig Uggerhøj Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, DK-8000 Aarhus C, Denmark
| | - Nathan Pumplin
- Swiss Federal Institute of Technology, Institute of Molecular Plant Biology, Universitätsstrasse 2, CH-8092 Zürich, Switzerland
| | - Erwin M Schoof
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Bygningstorvet, DK-2800 Lyngby, Denmark
| | - Peter Brodersen
- Copenhagen Plant Science Center, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
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2
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Brine TJ, Viswanathan SB, Murphy AM, Pate AE, Wamonje FO, Carr JP. Investigating the interactions of endornaviruses with each other and with other viruses in common bean, Phaseolus vulgaris. Virol J 2023; 20:216. [PMID: 37737192 PMCID: PMC10515030 DOI: 10.1186/s12985-023-02184-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 09/13/2023] [Indexed: 09/23/2023] Open
Abstract
BACKGROUND Plant viruses of the genus Alphaendornavirus are transmitted solely via seed and pollen and generally cause no apparent disease. It has been conjectured that certain plant endornaviruses may confer advantages on their hosts through improved performance (e.g., seed yield) or resilience to abiotic or biotic insult. We recently characterised nine common bean (Phaseolus vulgaris L.) varieties that harboured either Phaseolus vulgaris endornavirus (PvEV1) alone, or PvEV1 in combination with PvEV2 or PvEV1 in combination with PvEV2 and PvEV3. Here, we investigated the interactions of these endornaviruses with each other, and with three infectious pathogenic viruses: cucumber mosaic virus (CMV), bean common mosaic virus (BCMV), and bean common mosaic necrosis virus (BCMNV). RESULTS In lines harbouring PvEV1, PvEV1 and PvEV2, or PvEV1, PvEV2 plus PvEV3, the levels of PvEV1 and PvEV3 RNA were very similar between lines, although there were variations in PvEV2 RNA accumulation. In plants inoculated with infectious viruses, CMV, BCMV and BCMNV levels varied between lines, but this was most likely due to host genotype differences rather than to the presence or absence of endornaviruses. We tested the effects of endornaviruses on seed production and seedborne transmission of infectious pathogenic viruses but found no consistent relationship between the presence of endornaviruses and seed yield or protection from seedborne transmission of infectious pathogenic viruses. CONCLUSIONS It was concluded that endornaviruses do not interfere with each other's accumulation. There appears to be no direct synergy or competition between infectious pathogenic viruses and endornaviruses, however, the effects of host genotype may obscure interactions between endornaviruses and infectious viruses. There is no consistent effect of endornaviruses on seed yield or susceptibility to seedborne transmission of other viruses.
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Affiliation(s)
- Thomas J Brine
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | | | - Alex M Murphy
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Adrienne E Pate
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Francis O Wamonje
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
- Pest and Pathogen Ecology, National Institute of Agricultural Botany, East Malling, ME19 6BJ, UK
| | - John P Carr
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK.
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3
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Fu C, Ma C, Zhu M, Liu W, Ma X, Li J, Liao Y, Liu D, Gu X, Wang H, Wang F. Transcriptomic and methylomic analyses provide insights into the molecular mechanism and prediction of heterosis in rice. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 115:139-154. [PMID: 36995901 DOI: 10.1111/tpj.16217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 03/14/2023] [Accepted: 03/24/2023] [Indexed: 06/19/2023]
Abstract
Heterosis has been widely used in multiple crops. However, the molecular mechanism and prediction of heterosis remains elusive. We generated five F1 hybrids [four showing better-parent heterosis (BPH) and one showing mid-parent heterosis], and performed the transcriptomic and methylomic analyses to identify the candidate genes for BPH and explore the molecular mechanism of heterosis and the potential predictors for heterosis. Transcriptomic results showed that most of the differentially expressed genes shared in the four better-parent hybrids were significantly enriched into the terms of molecular function, and the additive and dominant effects played crucial roles for BPH. DNA methylation level, especially in CG context, significantly and positively correlated with grain yield per plant. The ratios of differentially methylated regions in CG context in exons to transcription start sites between the parents exhibited significantly negative correlation with the heterosis levels of their hybrids, as was further confirmed in 24 pairwise comparisons of other rice lines, implying that this ratio could be a feasible predictor for heterosis level, and this ratio of less than 5 between parents in early growth stages might be a critical index for judging that their F1 hybrids would show BPH. Additionally, we identified some important genes showing differential expression and methylation, such as OsDCL2, Pi5, DTH2, DTH8, Hd1 and GLW7 in the four better-parent hybrids as the candidate genes for BPH. Our findings helped shed more light on the molecular mechanism and heterosis prediction.
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Affiliation(s)
- Chongyun Fu
- Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- Guangdong Key Laboratory of New Technology in Rice Breeding, Guangzhou, China
- Guangdong Rice Engineering Laboratory, Guangzhou, China
- Key Laboratory of Genetics and Breeding of High Quality Rice in Southern China, Ministry of Agriculture and Rural Affairs Beijing, China
| | - Ce Ma
- Novogene Biotechnology Inc, Beijing, China
| | - Manshan Zhu
- Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- Guangdong Key Laboratory of New Technology in Rice Breeding, Guangzhou, China
- Guangdong Rice Engineering Laboratory, Guangzhou, China
- Key Laboratory of Genetics and Breeding of High Quality Rice in Southern China, Ministry of Agriculture and Rural Affairs Beijing, China
| | - Wuge Liu
- Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- Guangdong Key Laboratory of New Technology in Rice Breeding, Guangzhou, China
- Guangdong Rice Engineering Laboratory, Guangzhou, China
- Key Laboratory of Genetics and Breeding of High Quality Rice in Southern China, Ministry of Agriculture and Rural Affairs Beijing, China
| | - Xiaozhi Ma
- Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- Guangdong Key Laboratory of New Technology in Rice Breeding, Guangzhou, China
- Guangdong Rice Engineering Laboratory, Guangzhou, China
- Key Laboratory of Genetics and Breeding of High Quality Rice in Southern China, Ministry of Agriculture and Rural Affairs Beijing, China
| | - Jinhua Li
- Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- Guangdong Key Laboratory of New Technology in Rice Breeding, Guangzhou, China
- Guangdong Rice Engineering Laboratory, Guangzhou, China
- Key Laboratory of Genetics and Breeding of High Quality Rice in Southern China, Ministry of Agriculture and Rural Affairs Beijing, China
| | - Yilong Liao
- Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- Guangdong Key Laboratory of New Technology in Rice Breeding, Guangzhou, China
- Guangdong Rice Engineering Laboratory, Guangzhou, China
- Key Laboratory of Genetics and Breeding of High Quality Rice in Southern China, Ministry of Agriculture and Rural Affairs Beijing, China
| | - Dilin Liu
- Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- Guangdong Key Laboratory of New Technology in Rice Breeding, Guangzhou, China
- Guangdong Rice Engineering Laboratory, Guangzhou, China
- Key Laboratory of Genetics and Breeding of High Quality Rice in Southern China, Ministry of Agriculture and Rural Affairs Beijing, China
| | - Xiaofeng Gu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Haiyang Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
| | - Feng Wang
- Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- Guangdong Key Laboratory of New Technology in Rice Breeding, Guangzhou, China
- Guangdong Rice Engineering Laboratory, Guangzhou, China
- Key Laboratory of Genetics and Breeding of High Quality Rice in Southern China, Ministry of Agriculture and Rural Affairs Beijing, China
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4
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Mansour A, Mannaa M, Hewedy O, Ali MG, Jung H, Seo YS. Versatile Roles of Microbes and Small RNAs in Rice and Planthopper Interactions. THE PLANT PATHOLOGY JOURNAL 2022; 38:432-448. [PMID: 36221916 PMCID: PMC9561162 DOI: 10.5423/ppj.rw.07.2022.0090] [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: 07/07/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 06/16/2023]
Abstract
Planthopper infestation in rice causes direct and indirect damage through feeding and viral transmission. Host microbes and small RNAs (sRNAs) play essential roles in regulating biological processes, such as metabolism, development, immunity, and stress responses in eukaryotic organisms, including plants and insects. Recently, advanced metagenomic approaches have facilitated investigations on microbial diversity and its function in insects and plants, highlighting the significance of microbiota in sustaining host life and regulating their interactions with the environment. Recent research has also suggested significant roles for sRNA-regulated genes during rice-planthopper interactions. The response and behavior of the rice plant to planthopper feeding are determined by changes in the host transcriptome, which might be regulated by sRNAs. In addition, the roles of microbial symbionts and sRNAs in the host response to viral infection are complex and involve defense-related changes in the host transcriptomic profile. This review reviews the structure and potential functions of microbes and sRNAs in rice and the associated planthopper species. In addition, the involvement of the microbiota and sRNAs in the rice-planthopper-virus interactions during planthopper infestation and viral infection are discussed.
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Affiliation(s)
- Abdelaziz Mansour
- Department of Integrated Biological Science, Pusan National University, Busan 46241,
Korea
- Department of Economic Entomology and Pesticides, Faculty of Agriculture, Cairo University, Giza 12613,
Egypt
| | - Mohamed Mannaa
- Department of Integrated Biological Science, Pusan National University, Busan 46241,
Korea
- Department of Plant Pathology, Cairo University, Giza 12613,
Egypt
| | - Omar Hewedy
- Department of Plant Agriculture, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1,
Canada
- Department of Genetics, Faculty of Agriculture, Menoufia University, Shibin El-Kom 32514,
Egypt
| | - Mostafa G. Ali
- Department of Botany and Microbiology, Faculty of Science, Benha University, Benha 13518,
Egypt
| | - Hyejung Jung
- Department of Integrated Biological Science, Pusan National University, Busan 46241,
Korea
| | - Young-Su Seo
- Department of Integrated Biological Science, Pusan National University, Busan 46241,
Korea
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5
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Liu F, Chern M, Jain R, Martin JA, Schakwitz WS, Ronald PC. Silencing of Dicer-like protein 2a restores the resistance phenotype in the rice mutant, sxi4 (suppressor of Xa21-mediated immunity 4). THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 110:646-657. [PMID: 35106860 DOI: 10.1111/tpj.15692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 01/23/2022] [Accepted: 01/25/2022] [Indexed: 06/14/2023]
Abstract
The rice immune receptor XA21 confers resistance to Xanthomonas oryzae pv. oryzae (Xoo), and upon recognition of the RaxX21-sY peptide produced by Xoo, XA21 activates the plant immune response. Here we screened 21 000 mutant plants expressing XA21 to identify components involved in this response, and reported here the identification of a rice mutant, sxi4, which is susceptible to Xoo. The sxi4 mutant carries a 32-kb translocation from chromosome 3 onto chromosome 7 and displays an elevated level of DCL2a transcript, encoding a Dicer-like protein. Silencing of DCL2a in the sxi4 genetic background restores resistance to Xoo. RaxX21-sY peptide-treated leaves of sxi4 retain the hallmarks of XA21-mediated immune response. However, WRKY45-1, a known negative regulator of rice resistance to Xoo, is induced in the sxi4 mutant in response to RaxX21-sY peptide treatment. A CRISPR knockout of a short interfering RNA (TE-siRNA815) in the intron of WRKY45-1 restores the resistance phenotype in sxi4. These results suggest a model where DCL2a accumulation negatively regulates XA21-mediated immunity by altering the processing of TE-siRNA815.
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Affiliation(s)
- Furong Liu
- Department of Plant Pathology and Genome Center, University of California, Davis, CA, 95616, USA
| | - Mawsheng Chern
- Department of Plant Pathology and Genome Center, University of California, Davis, CA, 95616, USA
| | - Rashmi Jain
- Department of Plant Pathology and Genome Center, University of California, Davis, CA, 95616, USA
| | - Joel A Martin
- Department of Energy Joint Genome Institute, Berkeley, CA, 94720, USA
| | - Wendy S Schakwitz
- Department of Energy Joint Genome Institute, Berkeley, CA, 94720, USA
| | - Pamela C Ronald
- Department of Plant Pathology and Genome Center, University of California, Davis, CA, 95616, USA
- Feedstocks Division, The Joint Bioenergy Institute, Emeryville, CA, 94608, USA
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6
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Bradamante G, Mittelsten Scheid O, Incarbone M. Under siege: virus control in plant meristems and progeny. THE PLANT CELL 2021; 33:2523-2537. [PMID: 34015140 PMCID: PMC8408453 DOI: 10.1093/plcell/koab140] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/14/2021] [Indexed: 05/29/2023]
Abstract
In the arms race between plants and viruses, two frontiers have been utilized for decades to combat viral infections in agriculture. First, many pathogenic viruses are excluded from plant meristems, which allows the regeneration of virus-free plant material by tissue culture. Second, vertical transmission of viruses to the host progeny is often inefficient, thereby reducing the danger of viral transmission through seeds. Numerous reports point to the existence of tightly linked meristematic and transgenerational antiviral barriers that remain poorly understood. In this review, we summarize the current understanding of the molecular mechanisms that exclude viruses from plant stem cells and progeny. We also discuss the evidence connecting viral invasion of meristematic cells and the ability of plants to recover from acute infections. Research spanning decades performed on a variety of virus/host combinations has made clear that, beside morphological barriers, RNA interference (RNAi) plays a crucial role in preventing-or allowing-meristem invasion and vertical transmission. How a virus interacts with plant RNAi pathways in the meristem has profound effects on its symptomatology, persistence, replication rates, and, ultimately, entry into the host progeny.
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Affiliation(s)
- Gabriele Bradamante
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Ortrun Mittelsten Scheid
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Marco Incarbone
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
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7
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Feng Q, Li Y, Zhao ZX, Wang WM. Contribution of Small RNA Pathway to Interactions of Rice with Pathogens and Insect Pests. RICE (NEW YORK, N.Y.) 2021; 14:15. [PMID: 33547972 PMCID: PMC7867673 DOI: 10.1186/s12284-021-00458-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 01/28/2021] [Indexed: 05/20/2023]
Abstract
Small RNAs (sRNAs) are mainly classified into microRNAs (miRNAs) and small interfering RNAs (siRNAs) according to their origin. miRNAs originate from single-stranded RNA precursors, whereas siRNAs originate from double-stranded RNA precursors that are synthesized by RNA-dependent RNA polymerases. Both of single-stranded and double-stranded RNA precursors are processed into sRNAs by Dicer-like proteins. Then, the sRNAs are loaded into ARGONAUTE proteins, forming RNA-induced silencing complexes (RISCs). The RISCs repress the expression of target genes with sequences complementary to the sRNAs through the cleavage of transcripts, the inhibition of translation or DNA methylation. Here, we summarize the recent progress of sRNA pathway in the interactions of rice with various parasitic organisms, including fungi, viruses, bacteria, as well as insects. Besides, we also discuss the hormone signal in sRNA pathway, and the emerging roles of circular RNAs and long non-coding RNAs in rice immunity. Obviously, small RNA pathway may act as a part of rice innate immunity to coordinate with growth and development.
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Affiliation(s)
- Qin Feng
- Rice Research Institute and Research Center for Crop Disease and Insect Pests, Sichuan Agricultural University at Wenjiang, 211 Huimin Road, Wenjiang District, Chengdu, 611130 China
| | - Yan Li
- Rice Research Institute and Research Center for Crop Disease and Insect Pests, Sichuan Agricultural University at Wenjiang, 211 Huimin Road, Wenjiang District, Chengdu, 611130 China
| | - Zhi-Xue Zhao
- Rice Research Institute and Research Center for Crop Disease and Insect Pests, Sichuan Agricultural University at Wenjiang, 211 Huimin Road, Wenjiang District, Chengdu, 611130 China
| | - Wen-Ming Wang
- Rice Research Institute and Research Center for Crop Disease and Insect Pests, Sichuan Agricultural University at Wenjiang, 211 Huimin Road, Wenjiang District, Chengdu, 611130 China
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8
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Otulak-Kozieł K, Kozieł E, Escalante C, Valverde RA. Ultrastructural Analysis of Cells From Bell Pepper ( Capsicum annuum) Infected With Bell Pepper Endornavirus. FRONTIERS IN PLANT SCIENCE 2020; 11:491. [PMID: 32411163 PMCID: PMC7199235 DOI: 10.3389/fpls.2020.00491] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/01/2020] [Indexed: 05/05/2023]
Abstract
Endornaviruses include viruses that infect fungi, oomycetes, and plants. The genome of plant endornaviruses consists of linear ssRNA ranging in size from approximately 13-18 kb and lacking capsid protein and cell-to-cell movement capability. Although, plant endornaviruses have not been shown to cause detectable changes in the plant phenotype, they have been associated with alterations of the host physiology. Except for the association of cytoplasmic vesicles with infections by Vicia faba endornavirus, effects on the plant cell ultrastructure caused by endornaviruses have not been reported. Bell pepper endornavirus (BPEV) has been identified in several pepper (Capsicum spp.) species. We conducted ultrastructural analyses of cells from two near-isogenic lines of the bell pepper (C. annuum) cv. Marengo, one infected with BPEV and the other BPEV-free, and found cellular alterations associated with BPEV-infections. Some cells of plants infected with BPEV exhibited alterations of organelles and other cell components. Affected cells were located mainly in the mesophyll and phloem tissues. Altered organelles included mitochondrion, chloroplast, and nucleus. The mitochondria from BPEV-infected plants exhibited low number of cristae and electron-lucent regions. Chloroplasts contained plastoglobules and small vesicles in the surrounding cytoplasm. Translucent regions in thylakoids were observed, as well as hypertrophy of the chloroplast structure. Many membranous vesicles were observed in the stroma along the envelope. The nuclei revealed a dilation of the nuclear envelope with vesicles and perinuclear areas. The organelle changes were accompanied by membranous structure rearrangements, such as paramural bodies and multivesicular bodies. These alterations were not observed in cells from plants of the BPEV-free line. Overall, the observed ultrastructural cell alterations associated with BPEV are similar to those caused by plant viruses and viroids and suggest some degree of parasitic interaction between BPEV and the plant host.
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Affiliation(s)
- Katarzyna Otulak-Kozieł
- Institute of Biology, Department of Botany, Warsaw University of Life Sciences—SGGW, Warsaw, Poland
| | - Edmund Kozieł
- Institute of Biology, Department of Botany, Warsaw University of Life Sciences—SGGW, Warsaw, Poland
| | - Cesar Escalante
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| | - Rodrigo A. Valverde
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
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9
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Takahashi H, Fukuhara T, Kitazawa H, Kormelink R. Virus Latency and the Impact on Plants. Front Microbiol 2019; 10:2764. [PMID: 31866963 PMCID: PMC6908805 DOI: 10.3389/fmicb.2019.02764] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 11/12/2019] [Indexed: 11/15/2022] Open
Abstract
Plant viruses are thought to be essentially harmful to the lives of their cultivated crop hosts. In most cases studied, the interaction between viruses and cultivated crop plants negatively affects host morphology and physiology, thereby resulting in disease. Native wild/non-cultivated plants are often latently infected with viruses without any clear symptoms. Although seemingly non-harmful, these viruses pose a threat to cultivated crops because they can be transmitted by vectors and cause disease. Reports are accumulating on infections with latent plant viruses that do not cause disease but rather seem to be beneficial to the lives of wild host plants. In a few cases, viral latency involves the integration of full-length genome copies into the host genome that, in response to environmental stress or during certain developmental stages of host plants, can become activated to generate and replicate episomal copies, a transition from latency to reactivation and causation of disease development. The interaction between viruses and host plants may also lead to the integration of partial-length segments of viral DNA genomes or copy DNA of viral RNA genome sequences into the host genome. Transcripts derived from such integrated viral elements (EVEs) may be beneficial to host plants, for example, by conferring levels of virus resistance and/or causing persistence/latency of viral infections. Studies on viral latency in wild host plants might help us to understand and elucidate the underlying mechanisms of latency and provide insights into the raison d’être for viruses in the lives of plants.
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Affiliation(s)
- Hideki Takahashi
- Laboratory of Plant Pathology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.,Plant Immunology Unit, International Education and Research Center for Food Agricultural Immunology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Toshiyuki Fukuhara
- Department of Applied Biological Sciences and Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Haruki Kitazawa
- Food and Feed Immunology Group, Laboratory of Animal Products Chemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.,Livestock Immunology Unit, International Education and Research Center for Food Agricultural Immunology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Richard Kormelink
- Laboratory of Virology, Wageningen University, Wageningen, Netherlands
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10
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Wang Y, Qiao R, Wei C, Li Y. Rice Dwarf Virus Small RNA Profiles in Rice and Leafhopper Reveal Distinct Patterns in Cross-Kingdom Hosts. Viruses 2019; 11:v11090847. [PMID: 31547224 PMCID: PMC6784124 DOI: 10.3390/v11090847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/03/2019] [Accepted: 09/07/2019] [Indexed: 11/16/2022] Open
Abstract
RNA silencing has evolved as a widespread antiviral strategy in many eukaryotic organisms. Antiviral RNA silencing is mediated by virus-derived small RNAs (vsiRNAs), created by the cleavage of double-stranded viral RNA substrates by Dicer (Dcr) in animals or Dicer-like (DCL) proteins in plants. However, little is known about how the RNA silencing mechanisms of different hosts respond to the same virus infection. We performed high-throughput small RNA sequencing in Nephotettix cincticeps and Oryza sativa infected with Rice dwarf phytoreovirus and analyzed the distinct accumulation of vsiRNAs in these two hosts. The results suggested a potential branch in the evolution of antiviral RNA silencing of insect and plant hosts. The rice vsiRNAs were predominantly 21 and 22 nucleotides (nt) long, suggesting that OsDCL4 and OsDCL2 are involved in their production, whereas 21-nt vsiRNAs dominated in leafhopper, suggesting the involvement of a Dcr-2 homolog. Furthermore, we identified ~50-fold more vsiRNAs in rice than in leafhoppers, which might be partially attributable to the activity of RNA-dependent RNA polymerase 6 (RDR6) in rice and the lack of RDR genes in leafhoppers. Our data established a basis for further comparative studies on the evolution of RNA silencing-based interactions between a virus and its hosts, across kingdoms.
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Affiliation(s)
- Yu Wang
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Rui Qiao
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Chunhong Wei
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Yi Li
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China.
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11
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Liao PF, Ouyang JX, Zhang JJ, Yang L, Wang X, Peng XJ, Wang D, Zhu YL, Li SB. OsDCL3b affects grain yield and quality in rice. PLANT MOLECULAR BIOLOGY 2019; 99:193-204. [PMID: 30652247 DOI: 10.1007/s11103-018-0806-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 11/29/2018] [Indexed: 06/09/2023]
Abstract
We reported that knockdown of OsDCL3b decreased grain yield but increased grain quality in rice, which is helpful for molecular breeding in crops. Multiple DICER-LIKE (DCL) genes usually exist and show diverse biochemical and phenotypic functions in land plants. In rice, the biochemical function of OsDCL3b is known to process 24-nucleotide panicle phased small RNAs, however, its phenotypic functions are unclear. Here we reported that knockdown of OsDCL3b led to reduced pollen fertility, seed setting rate, and decreased grain yield but increased grain quality in rice. To reveal the molecular mechanism of the above phenomena, extracted RNAs from rice panicles of the wild type (WT) and OsDCL3b-RNAi line S6-1 were analyzed by deep sequencing. It showed that knockdown of OsDCL3b affected the biogenesis of both 21- and 24-nucleotide small RNAs including miRNAs and phased small RNAs. Using RNA-seq, 644 up- and 530 down-regulated mRNA genes were identified in panicles of line S6-1, and 550 and 273 differentially spliced genes with various alternative splicing (AS) events were observed in panicles of line S6-1 and WT, respectively, suggesting that OsDCL3b involved in influencing the transcript levels of mRNA genes and the AS events in rice panicles. Thus, our results show that knockdown of OsDCL3b will affect the biogenesis of small RNAs, which is involved in regulating the transcription of mRNA genes, and consequently influence the grain yield and quality in rice.
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Affiliation(s)
- Peng-Fei Liao
- Key Laboratory of Molecular Biology and Gene Engineering in Jiangxi Province, School of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - Jie-Xiu Ouyang
- Key Laboratory of Molecular Biology and Gene Engineering in Jiangxi Province, School of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - Jian-Jun Zhang
- College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Lan Yang
- Key Laboratory of Molecular Biology and Gene Engineering in Jiangxi Province, School of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - Xin Wang
- Key Laboratory of Molecular Biology and Gene Engineering in Jiangxi Province, School of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - Xiao-Jue Peng
- Key Laboratory of Molecular Biology and Gene Engineering in Jiangxi Province, School of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - Dong Wang
- Key Laboratory of Molecular Biology and Gene Engineering in Jiangxi Province, School of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - You-Lin Zhu
- Key Laboratory of Molecular Biology and Gene Engineering in Jiangxi Province, School of Life Sciences, Nanchang University, Nanchang, 330031, China.
| | - Shao-Bo Li
- Key Laboratory of Molecular Biology and Gene Engineering in Jiangxi Province, School of Life Sciences, Nanchang University, Nanchang, 330031, China.
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12
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Endornaviruses: persistent dsRNA viruses with symbiotic properties in diverse eukaryotes. Virus Genes 2019; 55:165-173. [DOI: 10.1007/s11262-019-01635-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 01/07/2019] [Indexed: 10/27/2022]
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13
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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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14
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Yang Z, Li Y. Dissection of RNAi-based antiviral immunity in plants. Curr Opin Virol 2018; 32:88-99. [PMID: 30388659 DOI: 10.1016/j.coviro.2018.08.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 08/03/2018] [Accepted: 08/05/2018] [Indexed: 10/28/2022]
Abstract
RNA interference (RNAi)-based antiviral defense is a small RNA-dependent repression mechanism of plants to against viruses. Although the core components of antiviral RNAi are well known, it is unclear whether additional factors exist that regulate RNAi. Recently, a forward genetic screen identified two novel components of antiviral RNAi, providing important insights into the antiviral RNAi mechanism. Meanwhile, it was discovered that microRNAs make important contributions to host antiviral RNAi. On the other hand, to counteract host antiviral RNAi, most viruses encode viral suppressors of RNA silencing (VSRs). Recent studies have revealed the multiple functions of VSRs and the intricate interactions between plant hosts and viruses. These findings add to our knowledge of the sophisticated host antiviral defense mechanism in plants. Ongoing molecular functional studies will improve our understanding of the co-evolutionary arms race between viruses and plants, and thereby provide key information for the development of plant antiviral strategies.
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Affiliation(s)
- Zhirui Yang
- The State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Yi Li
- The State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.
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15
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Physiological traits of endornavirus-infected and endornavirus-free common bean (Phaseolus vulgaris) cv Black Turtle Soup. Arch Virol 2018; 163:1051-1056. [DOI: 10.1007/s00705-018-3702-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 11/25/2017] [Indexed: 11/26/2022]
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16
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Matsuo K, Matsumura T. Repression of the DCL2 and DCL4 genes in Nicotiana benthamiana plants for the transient expression of recombinant proteins. J Biosci Bioeng 2017; 124:215-220. [PMID: 28336416 DOI: 10.1016/j.jbiosc.2017.02.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 02/01/2017] [Accepted: 02/26/2017] [Indexed: 01/01/2023]
Abstract
The production of recombinant proteins in plants has many advantages, including safety and reduced costs. However, this technology still faces several issues, including low levels of production. The repression of RNA silencing seems to be particularly important for improving recombinant protein production because RNA silencing effectively degrades transgene-derived mRNAs in plant cells. Therefore, to overcome this, we used RNA interference technology to develop DCL2- and DCL4-repressed transgenic Nicotiana benthamiana plants (ΔD2, ΔD4, and ΔD2ΔD4 plants), which had much lower levels of NbDCL2 and/or NbDCL4 mRNAs than wild-type plants. A transient gene expression assay showed that the ΔD2ΔD4 plants accumulated larger amounts of green fluorescent protein (GFP) and human acidic fibroblast growth factor (aFGF) than ΔD2, ΔD4, and wild-type plants. Furthermore, the levels of GFP and aFGF mRNAs were also higher in ΔD2ΔD4 plants than in ΔD2, ΔD4, and wild-type plants. These findings demonstrate that ΔD2ΔD4 plants express larger amounts of recombinant proteins than wild-type plants, and so would be useful for recombinant protein production.
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Affiliation(s)
- Kouki Matsuo
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan.
| | - Takeshi Matsumura
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan
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17
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Paces J, Nic M, Novotny T, Svoboda P. Literature review of baseline information to support the risk assessment of RNAi‐based GM plants. ACTA ACUST UNITED AC 2017. [PMCID: PMC7163844 DOI: 10.2903/sp.efsa.2017.en-1246] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jan Paces
- Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic (IMG)
| | | | | | - Petr Svoboda
- Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic (IMG)
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18
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Garcia-Ruiz H, Ruiz MTG, Peralta SMG, Gabriel CBM, El-Mounadi K. Mechanisms, applications, and perspectives of antiviral RNA silencing in plants. ACTA ACUST UNITED AC 2016; 34. [PMID: 28890589 DOI: 10.18781/r.mex.fit.1606-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Viral diseases of plants cause important economic losses due to reduction in crop quality and quantity to the point of threatening food security in some countries. Given the reduced availability of natural sources, genetic resistance to viruses has been successfully engineered for some plant-virus combinations. A sound understanding of the basic mechanisms governing plant-virus interactions, including antiviral RNA silencing, is the foundation to design better management strategies and biotechnological approaches to engineer and implement antiviral resistance in plants. In this review, we present current molecular models to explain antiviral RNA silencing and its application in basic plant research, biotechnology and genetic engineering.
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Affiliation(s)
- Hernan Garcia-Ruiz
- Department of Plant Pathology, Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583 USA
| | | | | | | | - Kautar El-Mounadi
- Department of Biology, Kuztown University of Pennsylvania, Kuztown, PA 19530 USA
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19
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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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20
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Abstract
Linear double-stranded RNAs (dsRNAs) of about 15 kbp in length are often found from healthy plants, such as bell pepper and rice plants. Nucleotide sequencing and phylogenetic analyses reveal that these dsRNAs are not transcribed from host genomic DNAs, encode a single long open reading frame (ORF) with a viral RNA-dependent RNA polymerase domain, and contain a site-specific nick in the 5' region of their coding strands. Consequently the International Committee on Taxonomy of Viruses has approved that these dsRNAs are viruses forming a distinct taxon, the family Endornaviridae the genus Endornavirus. Endornaviruses have common properties that differ from those of conventional viruses: they have no obvious effect on the phenotype of their host plants, and they are efficiently transmitted to the next generation via both pollen and ova, but their horizontal transfer to other plants has never been proven. Conventional single-stranded RNA viruses, such as cucumber mosaic virus, propagate hugely and systemically in host plants to sometime kill their hosts eventually and transmit horizontally (infect to other plants). In contrast, copy numbers of endornaviruses are low and constant (about 100 copies/cell), and they symbiotically propagate with host plants and transmit vertically. Therefore, endornaviruses are unique plant viruses with symbiotic properties.
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21
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Rajeswaran R, Golyaev V, Seguin J, Zvereva AS, Farinelli L, Pooggin MM. Interactions of Rice tungro bacilliform pararetrovirus and its protein P4 with plant RNA-silencing machinery. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:1370-8. [PMID: 25122481 DOI: 10.1094/mpmi-07-14-0201-r] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Small interfering RNA (siRNA)-directed gene silencing plays a major role in antiviral defense. Virus-derived siRNAs inhibit viral replication in infected cells and potentially move to neighboring cells, immunizing them from incoming virus. Viruses have evolved various ways to evade and suppress siRNA production or action. Here, we show that 21-, 22-, and 24-nucleotide (nt) viral siRNAs together constitute up to 19% of total small RNA population of Oryza sativa plants infected with Rice tungro bacilliform virus (RTBV) and cover both strands of the RTBV DNA genome. However, viral siRNA hotspots are restricted to a short noncoding region between transcription and reverse-transcription start sites. This region generates double-stranded RNA (dsRNA) precursors of siRNAs and, in pregenomic RNA, forms a stable secondary structure likely inaccessible to siRNA-directed cleavage. In transient assays, RTBV protein P4 suppressed cell-to-cell spread of silencing but enhanced cell-autonomous silencing, which correlated with reduced 21-nt siRNA levels and increased 22-nt siRNA levels. Our findings imply that RTBV generates decoy dsRNA that restricts siRNA production to the structured noncoding region and thereby protects other regions of the viral genome from repressive action of siRNAs, while the viral protein P4 interferes with cell-to-cell spread of antiviral silencing.
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22
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Campo S, Peris-Peris C, Siré C, Moreno AB, Donaire L, Zytnicki M, Notredame C, Llave C, San Segundo B. Identification of a novel microRNA (miRNA) from rice that targets an alternatively spliced transcript of the Nramp6 (Natural resistance-associated macrophage protein 6) gene involved in pathogen resistance. THE NEW PHYTOLOGIST 2013; 199:212-227. [PMID: 23627500 DOI: 10.1111/nph.12292] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Accepted: 02/26/2013] [Indexed: 05/18/2023]
Abstract
Plants have evolved efficient defence mechanisms to defend themselves from pathogen attack. Although many studies have focused on the transcriptional regulation of defence responses, less is known about the involvement of microRNAs (miRNAs) as post-transcriptional regulators of gene expression in plant immunity. This work investigates miRNAs that are regulated by elicitors from the blast fungus Magnaporthe oryzae in rice (Oryza sativa). Small RNA libraries were constructed from rice tissues and subjected to high-throughput sequencing for the identification of elicitor-responsive miRNAs. Target gene expression was examined by microarray analysis. Transgenic lines were used for the analysis of miRNA functioning in disease resistance. Elicitor treatment is accompanied by dynamic alterations in the expression of a significant number of miRNAs, including new members of annotated miRNAs. Novel miRNAs from rice are proposed. We report a new rice miRNA, osa-miR7695, which negatively regulates an alternatively spliced transcript of OsNramp6 (Natural resistance-associated macrophage protein 6). This novel miRNA experienced natural and domestication selection events during evolution, and its overexpression in rice confers pathogen resistance. This study highlights an miRNA-mediated regulation of OsNramp6 in disease resistance, whilst illustrating the existence of a novel regulatory network that integrates miRNA function and mRNA processing in plant immunity.
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Affiliation(s)
- Sonia Campo
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Edifici CRAG, Campus UAB, Bellaterra (Cerdanyola del Vallés), Barcelona, 08193, Spain
- Department of Environmental Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Cristina Peris-Peris
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Edifici CRAG, Campus UAB, Bellaterra (Cerdanyola del Vallés), Barcelona, 08193, Spain
| | - Christelle Siré
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Edifici CRAG, Campus UAB, Bellaterra (Cerdanyola del Vallés), Barcelona, 08193, Spain
| | - Ana Beatriz Moreno
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Edifici CRAG, Campus UAB, Bellaterra (Cerdanyola del Vallés), Barcelona, 08193, Spain
| | - Livia Donaire
- Department of Environmental Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Matthias Zytnicki
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), UPF, 08003, Barcelona, Spain
| | - Cedric Notredame
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), UPF, 08003, Barcelona, Spain
| | - César Llave
- Department of Environmental Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Blanca San Segundo
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Edifici CRAG, Campus UAB, Bellaterra (Cerdanyola del Vallés), Barcelona, 08193, Spain
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23
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Molecular characterization of five betacryptoviruses infecting four clover species and dill. Arch Virol 2013; 158:1943-52. [DOI: 10.1007/s00705-013-1691-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 03/02/2013] [Indexed: 11/26/2022]
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24
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Okada R, Yong CK, Valverde RA, Sabanadzovic S, Aoki N, Hotate S, Kiyota E, Moriyama H, Fukuhara T. Molecular characterization of two evolutionarily distinct endornaviruses co-infecting common bean (Phaseolus vulgaris). J Gen Virol 2013; 94:220-229. [DOI: 10.1099/vir.0.044487-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
Abstract
Two high-molecular-mass dsRNAs of approximately 14 and 15 kbp were isolated from the common bean (Phaseolus vulgaris) cultivar Black Turtle Soup. These dsRNAs did not appear to cause obvious disease symptoms, and were transmitted through seeds at nearly 100 % efficiency. Sequence information indicates that they are the genomes of distinct endornavirus species, for which the names Phaseolus vulgaris endornavirus 1 (PvEV-1) and Phaseolus vulgaris endornavirus 2 (PvEV-2) are proposed. The PvEV-1 genome consists of 13 908 bp and potentially encodes a single polyprotein of 4496 aa, while that of PvEV-2 consists of 14 820 bp and potentially encodes a single ORF of 4851 aa. PvEV-1 is more similar to Oryza sativa endornavirus, while PvEV-2 is more similar to bell pepper endornavirus. Both viruses have a site-specific nick near the 5′ region of the coding strand, which is a common property of the endornaviruses. Their polyproteins contain domains of RNA helicase, UDP-glycosyltransferase and RNA-dependent RNA polymerase, which are conserved in other endornaviruses. However, a viral methyltransferase domain was found in the N-terminal region of PvEV-2, but was absent in PvEV-1. Results of cell-fractionation studies suggested that their subcellular localizations were different. Most endornavirus-infected bean cultivars tested were co-infected with both viruses.
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Affiliation(s)
- Ryo Okada
- Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Chee Keat Yong
- Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Rodrigo A. Valverde
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, 70803, USA
| | - Sead Sabanadzovic
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA
| | - Nanako Aoki
- Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Shunsuke Hotate
- Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Eri Kiyota
- Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Hiromitsu Moriyama
- Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Toshiyuki Fukuhara
- Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
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25
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Jung HJ, Jung HJ, Ahmed NU, Park JI, Kang KK, Hur Y, Lim YP, Nou IS. Development of self-compatible B. rapa by RNAi-mediated S locus gene silencing. PLoS One 2012; 7:e49497. [PMID: 23145180 PMCID: PMC3493532 DOI: 10.1371/journal.pone.0049497] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 10/09/2012] [Indexed: 11/19/2022] Open
Abstract
The self-incompatibility (SI) system is genetically controlled by a single polymorphic locus known as the S-locus in the Brassicaceae. Pollen rejection occurs when the stigma and pollen share the same S-haplotype. Recognition of S-haplotype specificity has recently been shown to involve at least two S-locus genes, S-receptor kinase (SRK) and S-locus protein 11 or S locus Cysteine-rich (SP11/SCR) protein. Here, we examined the function of S(60), one SP11/SCR allele of B. rapa cv. Osome, using a RNAi-mediated gene silencing approach. The transgenic RNAi lines were highly self-compatible, and this trait was stable in subsequent generations, even after crossing with other commercial lines. These findings also suggested that the resultant self-compatibility could be transferred to commercial cultivars with the desired performances in B. rapa.
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Affiliation(s)
- Hee-Jeong Jung
- Department of Horticulture, Sunchon National University, Suncheon, Republic of Korea
| | - Hyo-Jin Jung
- Department of Horticulture, Jeollanam-do Agricultural Research and Extension Services, Najusi, Republic of Korea
| | - Nasar Uddin Ahmed
- Department of Horticulture, Sunchon National University, Suncheon, Republic of Korea
| | - Jong-In Park
- Department of Horticulture, Sunchon National University, Suncheon, Republic of Korea
| | - Kwon-Kyoo Kang
- Department of Horticulture, Hankyong National University, Ansung, Republic of Korea
| | - Yoonkang Hur
- Department of Biology, Chungnam National University, Daejeon, Republic of Korea
| | - Yong-Pyo Lim
- Department of Horticulture, Chungnam National University, Daejeon, Republic of Korea
| | - Ill-Sup Nou
- Department of Horticulture, Sunchon National University, Suncheon, Republic of Korea
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Song X, Li P, Zhai J, Zhou M, Ma L, Liu B, Jeong DH, Nakano M, Cao S, Liu C, Chu C, Wang XJ, Green PJ, Meyers BC, Cao X. Roles of DCL4 and DCL3b in rice phased small RNA biogenesis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 69:462-74. [PMID: 21973320 DOI: 10.1111/j.1365-313x.2011.04805.x] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Higher plants have evolved multiple proteins in the RNase III family to produce and regulate different classes of small RNAs with specialized molecular functions. In rice (Oryza sativa), numerous genomic clusters are targeted by one of two microRNAs (miRNAs), miR2118 and miR2275, to produce secondary small interfering RNAs (siRNAs) of either 21 or 24 nucleotides in a phased manner. The biogenesis requirements or the functions of the phased small RNAs are completely unknown. Here we examine the rice Dicer-Like (DCL) family, including OsDCL1, -3a, -3b and -4. By deep sequencing of small RNAs from different tissues of the wild type and osdcl4-1, we revealed that the processing of 21-nucleotide siRNAs, including trans-acting siRNAs (tasiRNA) and over 1000 phased small RNA loci, was largely dependent on OsDCL4. Surprisingly, the processing of 24-nucleotide phased small RNA requires the DCL3 homolog OsDCL3b rather than OsDCL3a, suggesting functional divergence within DCL3 family. RNA ligase-mediated 5' rapid amplification of cDNA ends and parallel analysis of RNA ends (PARE)/degradome analysis confirmed that most of the 21- and 24-nucleotide phased small RNA clusters were initiated from the target sites of miR2118 and miR2275, respectively. Furthermore, the accumulation of the two triggering miRNAs requires OsDCL1 activity. Finally, we show that phased small RNAs are preferentially produced in the male reproductive organs and are likely to be conserved in monocots. Our results revealed significant roles of OsDCL4, OsDCL3b and OsDCL1 in the 21- and 24-nucleotide phased small RNA biogenesis pathway in rice.
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Affiliation(s)
- Xianwei Song
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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27
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Göker M, Scheuner C, Klenk HP, Stielow JB, Menzel W. Codivergence of mycoviruses with their hosts. PLoS One 2011; 6:e22252. [PMID: 21829452 PMCID: PMC3146478 DOI: 10.1371/journal.pone.0022252] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Accepted: 06/17/2011] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The associations between pathogens and their hosts are complex and can result from any combination of evolutionary events such as codivergence, switching, and duplication of the pathogen. Mycoviruses are RNA viruses which infect fungi and for which natural vectors are so far unknown. Thus, lateral transfer might be improbable and codivergence their dominant mode of evolution. Accordingly, mycoviruses are a suitable target for statistical tests of virus-host codivergence, but inference of mycovirus phylogenies might be difficult because of low sequence similarity even within families. METHODOLOGY We analyzed here the evolutionary dynamics of all mycovirus families by comparing virus and host phylogenies. Additionally, we assessed the sensitivity of the co-phylogenetic tests to the settings for inferring virus trees from their genome sequences and approximate, taxonomy-based host trees. CONCLUSIONS While sequence alignment filtering modes affected branch support, the overall results of the co-phylogenetic tests were significantly influenced only by the number of viruses sampled per family. The trees of the two largest families, Partitiviridae and Totiviridae, were significantly more similar to those of their hosts than expected by chance, and most individual host-virus links had a significant positive impact on the global fit, indicating that codivergence is the dominant mode of virus diversification. However, in this regard mycoviruses did not differ from closely related viruses sampled from non-fungus hosts. The remaining virus families were either dominated by other evolutionary modes or lacked an apparent overall pattern. As this negative result might be caused by insufficient taxon sampling, the most parsimonious hypothesis still is that host-parasite evolution is basically the same in all mycovirus families. This is the first study of mycovirus-host codivergence, and the results shed light not only on how mycovirus biology affects their co-phylogenetic relationships, but also on their presumable host range itself.
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Affiliation(s)
- Markus Göker
- DSMZ-German Collection for Microorganisms and Cell Cultures, Braunschweig, Germany.
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Chen D, Meng Y, Yuan C, Bai L, Huang D, Lv S, Wu P, Chen LL, Chen M. Plant siRNAs from introns mediate DNA methylation of host genes. RNA (NEW YORK, N.Y.) 2011; 17:1012-24. [PMID: 21518803 PMCID: PMC3096033 DOI: 10.1261/rna.2589011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Small RNAs (sRNAs), largely known as microRNAs (miRNAs) and short interfering RNAs (siRNAs), emerged as the critical components of genetic and epigenetic regulation in eukaryotic genomes. In animals, a sizable portion of miRNAs reside within the introns of protein-coding genes, designated as mirtron genes. Recently, high-throughput sequencing (HTS) revealed a huge amount of sRNAs that derived from introns in plants, such as the monocot rice (Oryza sativa). However, the biogenesis and the biological functions of this kind of sRNAs remain elusive. Here, we performed a genome-scale survey of intron-derived sRNAs in rice based on HTS data. Several introns were found to have great potential to form internal hairpin structures, and the short hairpins could generate miRNAs while the larger ones could produce siRNAs. Furthermore, 22 introns, termed "sirtrons," were identified from the rice protein-coding genes. The single-stranded sirtrons produced a diverse set of siRNAs from long hairpin structures. These sirtron-derived siRNAs are dominantly 21 nt, 22 nt, and 24 nt in length, whose production relied on DCL4, DCL2, and DCL3, respectively. We also observed a strong tendency for the sirtron-derived siRNAs to be coexpressed with their host genes. Finally, the 24-nt siRNAs incorporated with Argonaute 4 (AGO4) could direct DNA methylation on their host genes. In this regard, homeostatic self-regulation between intron-derived siRNAs and their host genes was proposed.
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MESH Headings
- DNA Methylation
- Gene Expression Regulation, Plant
- Genes, Plant
- Genome, Plant
- Introns/genetics
- MicroRNAs/genetics
- MicroRNAs/metabolism
- Models, Biological
- Nucleic Acid Conformation
- Oryza/genetics
- RNA, Plant/chemistry
- RNA, Plant/genetics
- RNA, Plant/metabolism
- RNA, Small Interfering/chemistry
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
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Affiliation(s)
- Dijun Chen
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
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Fukuhara T, Urayama S, Okada R, Kiyota E, Moriyama H. Detection of long and short double-stranded RNAs. Methods Mol Biol 2011; 744:129-44. [PMID: 21533690 DOI: 10.1007/978-1-61779-123-9_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In RNA interference (RNAi), long double-stranded RNAs (dsRNAs) of more than 100 nucleotides (nt) are diced into short dsRNAs (small interfering RNAs, siRNAs) of about 21-24 nt, the guide strand of which is incorporated into the RNA-induced silencing complex (RISC) that slices a specific mRNA. Consequently viral dsRNAs are known as potent inducers for RNAi, which probably originated from a defense mechanism against nucleic acid parasites. Therefore detection of long and short dsRNAs must be crucial techniques for RNAi or virus research. The methods for simple and sensitive detection of short dsRNAs (siRNAs) by northern hybridization, isolation of long dsRNAs by CF-11 cellulose chromatography, and detection of long dsRNAs by agarose gel electrophoresis and northern hybridization are described here.
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Affiliation(s)
- Toshiyuki Fukuhara
- Department of Applied Biological Sciences, Tokyo University of Agriculture and Technology, Tokyo, Japan.
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Stielow B, Klenk HP, Menzel W. Complete genome sequence of the first endornavirus from the ascocarp of the ectomycorrhizal fungus Tuber aestivum Vittad. Arch Virol 2010; 156:343-5. [DOI: 10.1007/s00705-010-0875-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Accepted: 11/24/2010] [Indexed: 11/28/2022]
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