1
|
Li S, Zhu H, He Y, Hong N, Wang G, Wang L. BdCV1-Encoded P3 Silencing Suppressor Identification and Its Roles in Botryosphaeria dothidea, Causing Pear Ring Rot Disease. Cells 2023; 12:2386. [PMID: 37830600 PMCID: PMC10571871 DOI: 10.3390/cells12192386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/27/2023] [Accepted: 09/27/2023] [Indexed: 10/14/2023] Open
Abstract
Pear ring rot disease is an important branch disease, caused by Botryosphaeria dothidea. With the discovery of fungal viruses, the use of their attenuated properties for biological control provides a new strategy for the biological control of fungal disease. RNA silencing is a major antiviral defense mechanism in plants, insects, and fungi. Viruses encode and utilize RNA silencing suppressors to suppress host defenses. Previous studies revealed that Botryosphaeria dothidea chrysovirus 1 (BdCV1) exhibited weak pathogenicity and could activate host gene silencing by infecting B. dothidea. The aim of our study was to investigate whether BdCV1 can encode a silencing suppressor and what effect it has on the host. In this study, the capability of silencing inhibitory activity of four BdCV1-encoded proteins was analyzed, and the P3 protein was identified as a BdCV1 RNA silencing suppressor in the exotic host Nicotiana benthamiana line 16c. In addition, we demonstrated that P3 could inhibit local silencing, block systemic RNA silencing, and induce the necrosis reaction of tobacco leaves. Furthermore, overexpression of P3 could slow down the growth rate and reduce the pathogenicity of B. dothidea, and to some extent affect the expression level of RNA silencing components and virus-derived siRNAs (vsiRNAs). Combined with transcriptomic analysis, P3 had an effect on the gene expression and biological process of B. dothidea. The obtained results provide new theoretical information for further study of interaction between BdCV1 P3 as a potential silencing suppressor and B. dothidea.
Collapse
Affiliation(s)
- Shanshan Li
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
- Key Laboratory of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
| | - Haodong Zhu
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
- Key Laboratory of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
| | - Ying He
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
- Key Laboratory of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
| | - Ni Hong
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
- Key Laboratory of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
| | - Guoping Wang
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
- Key Laboratory of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
| | - Liping Wang
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
- Key Laboratory of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
| |
Collapse
|
2
|
Chergintsev DA, Solovieva AD, Atabekova AK, Lezzhov AA, Golyshev SA, Morozov SY, Solovyev AG. Properties of Plant Virus Protein Encoded by the 5'-Proximal Gene of Tetra-Cistron Movement Block. Int J Mol Sci 2023; 24:14144. [PMID: 37762447 PMCID: PMC10532019 DOI: 10.3390/ijms241814144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/08/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
To move from cell to cell through plasmodesmata, many plant viruses require the concerted action of two or more movement proteins (MPs) encoded by transport gene modules of virus genomes. A tetra-cistron movement block (TCMB) is a newly discovered transport module comprising four genes. TCMB encodes three proteins, which are similar to MPs of the transport module known as the "triple gene block", and a protein unrelated to known viral MPs and containing a double-stranded RNA (dsRNA)-binding domain similar to that found in a family of cell proteins, including AtDRB4 and AtHYL1. Here, the latter TCMB protein, named vDRB for virus dsRNA-binding protein, is shown to bind both dsRNA and single-stranded RNA in vitro. In a turnip crinkle virus-based assay, vDRB exhibits the properties of a viral suppressor of RNA silencing (VSR). In the context of potato virus X infection, vDRB significantly decreases the number and size of "dark green islands", regions of local antiviral silencing, supporting the VSR function of vDRB. Nevertheless, vDRB does not exhibit the VSR properties in non-viral transient expression assays. Taken together, the data presented here indicate that vDRB is an RNA-binding protein exhibiting VSR functions in the context of viral infection.
Collapse
Affiliation(s)
- Denis A. Chergintsev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia;
| | - Anna D. Solovieva
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia;
| | - Anastasia K. Atabekova
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
| | - Alexander A. Lezzhov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
| | - Sergei A. Golyshev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
| | - Sergey Y. Morozov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia;
| | - Andrey G. Solovyev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia;
| |
Collapse
|
3
|
Atabekova AK, Solovieva AD, Chergintsev DA, Solovyev AG, Morozov SY. Role of Plant Virus Movement Proteins in Suppression of Host RNAi Defense. Int J Mol Sci 2023; 24:ijms24109049. [PMID: 37240394 DOI: 10.3390/ijms24109049] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023] Open
Abstract
One of the systems of plant defense against viral infection is RNA silencing, or RNA interference (RNAi), in which small RNAs derived from viral genomic RNAs and/or mRNAs serve as guides to target an Argonaute nuclease (AGO) to virus-specific RNAs. Complementary base pairing between the small interfering RNA incorporated into the AGO-based protein complex and viral RNA results in the target cleavage or translational repression. As a counter-defensive strategy, viruses have evolved to acquire viral silencing suppressors (VSRs) to inhibit the host plant RNAi pathway. Plant virus VSR proteins use multiple mechanisms to inhibit silencing. VSRs are often multifunctional proteins that perform additional functions in the virus infection cycle, particularly, cell-to-cell movement, genome encapsidation, or replication. This paper summarizes the available data on the proteins with dual VSR/movement protein activity used by plant viruses of nine orders to override the protective silencing response and reviews the different molecular mechanisms employed by these proteins to suppress RNAi.
Collapse
Affiliation(s)
- Anastasia K Atabekova
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia
| | - Anna D Solovieva
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
| | - Denis A Chergintsev
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
| | - Andrey G Solovyev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
| | - Sergey Y Morozov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
| |
Collapse
|
4
|
Silencing suppressor protein PRT of rice tungro bacilliform virus interacts with the plant RNA silencing-related protein SGS3. Virology 2023; 581:71-80. [PMID: 36921478 DOI: 10.1016/j.virol.2023.02.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 02/16/2023] [Accepted: 02/22/2023] [Indexed: 03/08/2023]
Abstract
BACKGROUND Rice tungro bacilliform virus (RTBV) is a double stranded DNA containing virus which causes the devastating tungro disease of rice in association with an RNA virus, rice tungro spherical virus. RNA silencing is an evolutionarily conserved antiviral defence pathway in plants as well as in several classes of higher organisms. Many viruses, in turn, encode proteins which are termed Viral Suppressor of RNA Silencing (VSR) because they downregulate or suppress RNA silencing. RESULTS Using an RNA silencing suppressor assay we show that RTBV protease (PRT) acts as a mild VSR. A truncated version of PRT gene abolished the silencing suppression activity. We also show in planta interaction of PRT with the SGS3 protein of Solanum tuberosum and Arabidopsis thaliana using bimolecular fluorescence complementation assay (BIFC). Transient expression of PRT in Nicotiana benthamiana caused an increased accumulation of the begomovirus Sri Lankan cassava mosaic virus (SLCMV) DNA-A, which indicated a virulence function imparted on an unrelated virus. CONCLUSION The finding supports the idea that PRT acts as suppressor of RNA silencing and this action may be mediated by its interaction with SGS3.
Collapse
|
5
|
Nishiguchi M, Ali ME, Kaya T, Kobayashi K. Plant virus disease control by vaccination and transgenic approaches: Current status and perspective. PLANT RNA VIRUSES 2023:373-424. [DOI: 10.1016/b978-0-323-95339-9.00028-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
|
6
|
Wang C, Yan Y, Huang M, Ma G, Wang L, Xie X, Xue W, Li X. Myricetin Derivative LP11 Targets Cucumber Mosaic Virus 2b Protein to Achieve In Vivo Antiviral Activity in Plants. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:15360-15370. [PMID: 36448924 DOI: 10.1021/acs.jafc.2c05536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Cucumber mosaic virus (CMV) 2b protein plays a key role in the process of CMV infecting plants and symptom formation and is a potential molecular target for the control of this important plant virus. The exploitation of antiviral compounds is one of the strategies with the highest input: output ratio in plant protection. In this study, the CMV 2b recombinant protein was cloned, purified, and identified as the target protein by mass spectrometry. Subsequently, we carried out preliminary functional screening of the LP series of myricetin derivatives designed and synthesized in our laboratory and commercial antiviral compounds by microscale thermophoresis (MST), which showed that LP compounds LP4, LP11, LP13, and LP20 interacted well with CMV 2b, with dissociation constant (Kd) values of 1.39, 0.88, 1.52, and 1.77 μM, respectively. Among the commercially available antiviral compounds, ningnanmycin (NNM) was the most active, with a Kd value of 4.09 μM. Then, the strongest binding force to CMV 2b was identified to be from LP11 by isothermal titration calorimetry (ITC) experiments, with a Kd of 1.19 μM. Among the commercial compounds, NNM had the strongest binding force with CMV 2b, with a Kd of 4.62 μM. Through the screening of commercial compounds and LP series compounds by MST and ITC, LP11, NNM (positive control), LP16 (negative control), and the blank control group were selected to test the in vivo impact of LP11 on CMV. Specifically, the screened compounds were sprayed onto CMV-inoculated Nicotiana benthamiana plants to determine their impact on the regulation of CMV pathogenic gene expression, symptoms, and virus titer. The results showed that LP11 had a strong ability to inhibit CMV infection of tobacco at the transcriptional and translational levels. By mutating the CMV 2b protein, the 15th amino acid leucine and the 18th amino acid methionine at the N-terminal region were shown to be potential sites for binding to compound LP11. This finding provided a theoretical basis for screening and developing anti-CMV agents.
Collapse
Affiliation(s)
- Chen Wang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, PR China
| | - Yunlong Yan
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, PR China
| | - Min Huang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, PR China
| | - Guangming Ma
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, PR China
| | - Li Wang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, PR China
- Department of Plant Pathology, College of Agriculture, Guizhou University, Huaxi District, Guiyang 550025, PR China
| | - Xin Xie
- Department of Plant Pathology, College of Agriculture, Guizhou University, Huaxi District, Guiyang 550025, PR China
| | - Wei Xue
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, PR China
| | - Xiangyang Li
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, PR China
| |
Collapse
|
7
|
Zheng L, Fu S, Xie Y, Han Y, Zhou X, Wu J. Discovery and Characterization of a Novel Umbravirus from Paederia scandens Plants Showing Leaf Chlorosis and Yellowing Symptoms. Viruses 2022; 14:v14081821. [PMID: 36016443 PMCID: PMC9414234 DOI: 10.3390/v14081821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/13/2022] [Accepted: 08/16/2022] [Indexed: 11/29/2022] Open
Abstract
Umbraviruses are a special class of plant viruses that do not encode any viral structural proteins. Here, a novel umbravirus that has been tentatively named Paederia scandens chlorosis yellow virus (PSCYV) was discovered through RNA-seq in Paederia scandens plants showing leaf chlorosis and yellowing symptoms. The PSCYV genome is a 4301 nt positive-sense, single strand RNA that contains four open reading frames (ORFs), i.e., ORF1–4, that encode P1–P4 proteins, respectively. Together, ORF1 and ORF2 are predicted to encode an additional protein, RdRp, through a −1 frameshift mechanism. The P3 protein encoded by ORF3 was predicted to be the viral long-distance movement protein. P4 was determined to function as the viral cell-to-cell movement protein (MP) and transcriptional gene silencing (TGS) suppressor. Both P1 and RdRp function as weak post-transcriptional gene silencing (PTGS) suppressors of PSCYV. The PVX-expression system indicated that all viral proteins may be symptom determinants of PSCYV. Phylogenetic analysis indicated that PSCYV is evolutionarily related to members of the genus Umbravirus in the family Tombusviridae. Furthermore, a cDNA infectious clone of PSCYV was successfully constructed and used to prove that PSCYV can infect both Paederia scandens and Nicotiana benthamiana plants through mechanical inoculation, causing leaf chlorosis and yellowing symptoms. These findings have broadened our understanding of umbraviruses and their host range.
Collapse
Affiliation(s)
- Lianshun Zheng
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- Hainan Institute, Zhejiang University, Sanya 572025, China
| | - Shuai Fu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Yi Xie
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Yang Han
- Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing 100101, China
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Correspondence: (X.Z.); (J.W.); Tel.: +86-571-88982250 (J.W.)
| | - Jianxiang Wu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- Hainan Institute, Zhejiang University, Sanya 572025, China
- Correspondence: (X.Z.); (J.W.); Tel.: +86-571-88982250 (J.W.)
| |
Collapse
|
8
|
Small RNAs Participate in Plant-Virus Interaction and Their Application in Plant Viral Defense. Int J Mol Sci 2022; 23:ijms23020696. [PMID: 35054880 PMCID: PMC8775341 DOI: 10.3390/ijms23020696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/30/2021] [Accepted: 01/05/2022] [Indexed: 02/06/2023] Open
Abstract
Small RNAs are significant regulators of gene expression, which play multiple roles in plant development, growth, reproductive and stress response. It is generally believed that the regulation of plants’ endogenous genes by small RNAs has evolved from a cellular defense mechanism for RNA viruses and transposons. Most small RNAs have well-established roles in the defense response, such as viral response. During viral infection, plant endogenous small RNAs can direct virus resistance by regulating the gene expression in the host defense pathway, while the small RNAs derived from viruses are the core of the conserved and effective RNAi resistance mechanism. As a counter strategy, viruses evolve suppressors of the RNAi pathway to disrupt host plant silencing against viruses. Currently, several studies have been published elucidating the mechanisms by which small RNAs regulate viral defense in different crops. This paper reviews the distinct pathways of small RNAs biogenesis and the molecular mechanisms of small RNAs mediating antiviral immunity in plants, as well as summarizes the coping strategies used by viruses to override this immune response. Finally, we discuss the current development state of the new applications in virus defense based on small RNA silencing.
Collapse
|
9
|
Pantaleo V, Masuta C. Diversity of viral RNA silencing suppressors and their involvement in virus-specific symptoms. Adv Virus Res 2022; 113:1-23. [DOI: 10.1016/bs.aivir.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
10
|
Eini O, Schumann N, Niessen M, Varrelmann M. Targeted mutagenesis in plants using Beet curly top virus for efficient delivery of CRISPR/Cas12a components. N Biotechnol 2021; 67:1-11. [PMID: 34896246 DOI: 10.1016/j.nbt.2021.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 11/29/2021] [Accepted: 12/05/2021] [Indexed: 10/19/2022]
Abstract
Genome editing using CRISPR/Cas is rapidly being developed for gene targeting in eukaryotes including plants. However, gene targeting by homology-directed DNA recombination (HDR) is an infrequent event compared to the dominant DNA repair by non-homologous end-joining. Another bottleneck is the ineffective delivery of CRISPR/Cas components into plant cells. To overcome these constraints, here a geminiviral replicon from Beet curly top virus (BCTV) has been produced with a wide host range and high DNA accumulation capacity for efficient delivery of CRISPR/Cas12a components into plant cells. Initially, a BCTV replicon was prepared after removing the virion sense genes from an infectious full-length clone for agrobacterium mediated infection. This replicon expressed a green fluorescent protein (GFP) marker gene at a high level compared to T-DNA binary vector. In transient assay, the BCTV replicon produced a higher rate of mutagenesis and HDR in the GFP transgene in Nicotiana benthamiana through efficient delivery of CRISPR/Cas12a components compared to the cognate T-DNA control. This was through a range of complete or partial HDR for conversion of GFP into YFP after exchange of a single amino acid (Thr224Tyr) in the target gene. In addition, induced mutagenesis and HDR in the target gene were heritable. Thus, the BCTV replicon provides a new tool for efficient delivery of CRISPR/Cas12a components that could be used in a wide range of dicotyledonous plants. The established GFP to YFP system and the GFP mutant line produced also enable further optimization and understanding of HDR in plants via CRISPR/Cas12a system using geminiviral replicons.
Collapse
Affiliation(s)
- Omid Eini
- Department of Plant Protection, University of Zanjan, 313, Zanjan, Iran; Department of Phytopathology, Institute for Sugar Beet Research, 37079, Göttingen, Germany.
| | | | | | - Mark Varrelmann
- Department of Phytopathology, Institute for Sugar Beet Research, 37079, Göttingen, Germany
| |
Collapse
|
11
|
Choudhary C, Meghwanshi KK, Shukla N, Shukla JN. Innate and adaptive resistance to RNAi: a major challenge and hurdle to the development of double stranded RNA-based pesticides. 3 Biotech 2021; 11:498. [PMID: 34881161 PMCID: PMC8595431 DOI: 10.1007/s13205-021-03049-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 10/31/2021] [Indexed: 10/19/2022] Open
Abstract
RNA interference (RNAi) is a post-transcriptional gene silencing process where short interfering RNAs degrade targeted mRNA. Exploration of gene function through reverse genetics is the major achievement of RNAi discovery. Besides, RNAi can be used as a potential strategy for the control of insect pests. This has led to the idea of developing RNAi-based pesticides. Differential RNAi efficiency in the different insect orders is the biggest biological obstacle in developing RNAi-based pesticides. dsRNA stability, the sensitivity of core RNAi machinery, uptake of dsRNA and amplification and spreading of the RNAi signal are the key factors responsible for RNAi efficiency in insects. This review discusses the physiological and adaptive factors responsible for reduced RNAi in insects that pose a major challenge in developing dsRNA- based pesticides.
Collapse
Affiliation(s)
- Chhavi Choudhary
- Department of Biotechnology, Central University of Rajasthan, NH-8, Bandarsindri, Distt. Ajmer, Kishangarh, Rajasthan 305817 India
| | - Keshav Kumar Meghwanshi
- Department of Biotechnology, Central University of Rajasthan, NH-8, Bandarsindri, Distt. Ajmer, Kishangarh, Rajasthan 305817 India
| | - Nidhi Shukla
- Birla Institute of Scientific Research, Statue Circle, Prithviraj Rd, C-Scheme, Jaipur, Rajasthan 302001 India
| | - Jayendra Nath Shukla
- Department of Biotechnology, Central University of Rajasthan, NH-8, Bandarsindri, Distt. Ajmer, Kishangarh, Rajasthan 305817 India
| |
Collapse
|
12
|
Characterization and evolutionary analysis of Cucumber mosaic virus isolate infecting Salvia sclarea in India. 3 Biotech 2021; 11:468. [PMID: 34745819 DOI: 10.1007/s13205-021-03023-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 10/07/2021] [Indexed: 10/20/2022] Open
Abstract
Cucumber mosaic virus (CMV) is one of the most widespread viruses that infects a large number of cultivated crops worldwide and causes severe losses. Besides vegetables and ornamental crops, it is also spreading on medicinal and aromatic plants (MAPs) at an alarming rate. Natural occurrence of green mosaic, leaf curling, necrosis, and distortion were observed on the leaves of Salvia sclarea in the experimental field of CSIR-CIMAP, Lucknow, India. Mechanical transmission assay, morphological features, CP gene, and RNA3-based genomic characterization revealed the association of a new CMV isolate with the present disease. Virus is mechanically sap transmissible to the test plants. Transmission electron microscopy showed the presence of isodiametric particles of ~ 28 nm in diameter. Phylogenetic studies revealed that RNA3 (~ 2.2 kb) belongs to the subgroup IA of CMV. Multiple sequence alignment of amino acid sequences showed that MP possesses two unique changes in the RNA-binding domain and CP was found to be the conserved one with one change only. To the best of our knowledge, this is the first report of a CMV isolate infecting S. sclarea.
Collapse
|
13
|
Sánchez-López EF, Corigliano MG, Oliferuk S, Ramos-Duarte VA, Rivera M, Mendoza-Morales LF, Angel SO, Sander VA, Clemente M. Oral Immunization With a Plant HSP90-SAG1 Fusion Protein Produced in Tobacco Elicits Strong Immune Responses and Reduces Cyst Number and Clinical Signs of Toxoplasmosis in Mice. FRONTIERS IN PLANT SCIENCE 2021; 12:726910. [PMID: 34675949 PMCID: PMC8525317 DOI: 10.3389/fpls.2021.726910] [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: 06/17/2021] [Accepted: 08/30/2021] [Indexed: 05/17/2023]
Abstract
Plant 90kDa heat shock protein (HSP90) is a potent adjuvant that increases both humoral and cellular immune responses to diverse proteins and peptides. In this study, we explored whether Arabidopsis thaliana HSP90 (AtHsp81.2) can improve the immune effects of a Toxoplasma gondii surface antigen 1 (SAG1). We designed two constructs containing the sequence of mature antigen (SAG1m), from aa77 to aa322, and B- and T-cell antigenic epitope-containing SAG1HC, from aa221 to aa319 fused to AtHsp81.2 sequence. When comparing the transient expression in Nicotiana tabacum X-27-8 leaves, which overexpress the suppressor helper component protease HC-Pro-tobacco etch virus (TEV), to that in N. benthamiana leaves, co-agroinfiltrated with the suppressor p19, optimal conditions included 6-week-old N. benthamiana plants, 7-day time to harvest, Agrobacterium tumefaciens cultures with an OD600nm of 0.6 for binary vectors and LED lights. While AtHsp81.2-SAG1m fusion protein was undetectable by Western blot in any of the evaluated conditions, AtHsp81.2-SAG1HC was expressed as intact fusion protein, yielding up to 90μg/g of fresh weight. Besides, the AtHsp81.2-SAG1HC mRNA was strongly expressed compared to the endogenous Nicotiana tabacum elongation factor-alpha (NtEFα) gene, whereas the AtHsp81.2-SAG1m mRNA was almost undetectable. Finally, mice were orally immunized with AtHsp81.2-SAG1HC-infiltrated fresh leaves (plAtHsp81.2-SAG1HC group), recombinant AtHsp81.2-SAG1HC purified from infiltrated leaves (rAtHsp81.2-SAG1HC group), non-infiltrated fresh leaves (control group), or phosphate-buffered saline (PBS group). Serum samples from plAtHsp81.2-SAG1HC-immunized mice had significantly higher levels of IgGt, IgG2a, and IgG2b anti-SAG1HC antibodies than serum from rAtHsp81.2-SAG1HC, control, and PBS groups. The number of cysts per brain in the plAtHsp81.2-SAG1HC-immunized mice was significantly reduced, and the parasite load in brain tissue was also lower in this group compared with the remaining groups. In an immunoblot assay, plant-expressed AtHsp81.2-SAG1HC was shown to react with antibodies present in sera from T. gondii-infected people. Therefore, the plant expression of a T. gondii antigen fused to the non-pathogenic adjuvant and carrier plant HSP90 as formulations against T. gondii can improve the vaccine efficacy, and plant extract can be directly used for vaccination without the need to purify the protein, making this platform a suitable and powerful biotechnological system for immunogenic antigen expression against toxoplasmosis.
Collapse
Affiliation(s)
- Edwin F. Sánchez-López
- Laboratorio de Molecular Farming y Vacunas, Instituto Tecnológico Chascomús (INTECH), Universidad Nacional de General San Martín (UNSAM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Chascomús, Argentina
| | - Mariana G. Corigliano
- Laboratorio de Molecular Farming y Vacunas, Instituto Tecnológico Chascomús (INTECH), Universidad Nacional de General San Martín (UNSAM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Chascomús, Argentina
| | - Sonia Oliferuk
- Laboratorio de Molecular Farming y Vacunas, Instituto Tecnológico Chascomús (INTECH), Universidad Nacional de General San Martín (UNSAM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Chascomús, Argentina
| | - Victor A. Ramos-Duarte
- Laboratorio de Molecular Farming y Vacunas, Instituto Tecnológico Chascomús (INTECH), Universidad Nacional de General San Martín (UNSAM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Chascomús, Argentina
| | - Maximiliano Rivera
- Laboratorio de Parasitología Molecular, Instituto Tecnológico Chascomús (INTECH), Universidad Nacional de General San Martín (UNSAM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Chascomús, Argentina
| | - Luisa F. Mendoza-Morales
- Laboratorio de Molecular Farming y Vacunas, Instituto Tecnológico Chascomús (INTECH), Universidad Nacional de General San Martín (UNSAM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Chascomús, Argentina
| | - Sergio O. Angel
- Laboratorio de Parasitología Molecular, Instituto Tecnológico Chascomús (INTECH), Universidad Nacional de General San Martín (UNSAM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Chascomús, Argentina
| | - Valeria A. Sander
- Laboratorio de Molecular Farming y Vacunas, Instituto Tecnológico Chascomús (INTECH), Universidad Nacional de General San Martín (UNSAM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Chascomús, Argentina
| | - Marina Clemente
- Laboratorio de Molecular Farming y Vacunas, Instituto Tecnológico Chascomús (INTECH), Universidad Nacional de General San Martín (UNSAM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Chascomús, Argentina
| |
Collapse
|
14
|
Genome editing for resistance against plant pests and pathogens. Transgenic Res 2021; 30:427-459. [PMID: 34143358 DOI: 10.1007/s11248-021-00262-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 05/27/2021] [Indexed: 12/12/2022]
Abstract
The conventional breeding of crops struggles to keep up with increasing food needs and ever-adapting pests and pathogens. Global climate changes have imposed another layer of complexity to biological systems, increasing the challenge to obtain improved crop cultivars. These dictate the development and application of novel technologies, like genome editing (GE), that assist targeted and fast breeding programs in crops, with enhanced resistance to pests and pathogens. GE does not require crossings, hence avoiding the introduction of undesirable traits through linkage in elite varieties, speeding up the whole breeding process. Additionally, GE technologies can improve plant protection by directly targeting plant susceptibility (S) genes or virulence factors of pests and pathogens, either through the direct edition of the pest genome or by adding the GE machinery to the plant genome or to microorganisms functioning as biocontrol agents (BCAs). Over the years, GE technology has been continuously evolving and more so with the development of CRISPR/Cas. Here we review the latest advancements of GE to improve plant protection, focusing on CRISPR/Cas-based genome edition of crops and pests and pathogens. We discuss how other technologies, such as host-induced gene silencing (HIGS) and the use of BCAs could benefit from CRISPR/Cas to accelerate the development of green strategies to promote a sustainable agriculture in the future.
Collapse
|
15
|
Guo H, Ge P, Tong J, Zhang Y, Peng X, Zhao Z, Ge F, Sun Y. Elevated Carbon Dioxide Levels Decreases Cucumber Mosaic Virus Accumulation in Correlation with Greater Accumulation of rgs-CaM, an Inhibitor of a Viral Suppressor of RNAi. PLANTS (BASEL, SWITZERLAND) 2020; 10:E59. [PMID: 33383811 PMCID: PMC7824600 DOI: 10.3390/plants10010059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/23/2020] [Accepted: 12/25/2020] [Indexed: 11/16/2022]
Abstract
Plant viruses cause a range of plant diseases symptoms that are often responsible for significant crop production losses and the severity and spread of the symptoms may be affected by climate change. While the increase in anthropogenic activities has caused a critical problem of increased CO2 levels in the atmosphere, these elevated CO2 levels have been reported to reduce virus disease severity in some plant species. In such instances, it is not clear if the plant defense mechanisms are being enhanced or virus-mediated mechanisms to overcome plant resistance are being defeated. Additionally, a few studies have been attempted in this area to determine if reduced disease is the norm or the exception under enhanced CO2 levels. In the present study, the effects of elevated CO2 levels (750 ppm vs. 390 ppm) on RNAi-mediated resistance of Nicotiana tabacum against the cucumber mosaic virus (CMV), and the activity of viral suppressor of RNAi (VSR) 2b protein of CMV were evaluated. On the one hand, our results showed that elevated CO2 decreased the transcription of dicer-like protein 2 (DCL2), DCL4, and argonaut 1 (AGO1) genes with functions related to RNAi-mediated resistance when infected by CMV, which is contradictory with the decreased CMV copy numbers under elevated CO2. On the other hand, we found that elevated CO2 increased the calcium concentration and expression of the calcium-binding protein rgs-CaM in tobacco plants when infected by CMV, which directly weakened the function of 2b protein, the VSR of CMV, and therefore decreased the infection efficiency of the virus and suppressed the severity of CMV in tobacco plants under elevated CO2. This study provides molecular insights into the ecological implications underlying the development of prevention strategies against plant virus infection in the context of climate change.
Collapse
Affiliation(s)
- Huijuan Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
- CAS Center for Excellence in Biotic Interactions, Chinese Academy of Sciences, Beijing 100049, China
| | - Panpan Ge
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
| | - Jiahui Tong
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China;
| | - Yanjing Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
| | - Xinhong Peng
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
- Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, China
| | - Zihua Zhao
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China;
| | - Feng Ge
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
- CAS Center for Excellence in Biotic Interactions, Chinese Academy of Sciences, Beijing 100049, China
| | - Yucheng Sun
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
- CAS Center for Excellence in Biotic Interactions, Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
16
|
Li N, Yu C, Yin Y, Gao S, Wang F, Jiao C, Yao M. Pepper Crop Improvement Against Cucumber Mosaic Virus (CMV): A Review. FRONTIERS IN PLANT SCIENCE 2020; 11:598798. [PMID: 33362830 PMCID: PMC7758397 DOI: 10.3389/fpls.2020.598798] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 11/13/2020] [Indexed: 06/12/2023]
Abstract
Cucumber mosaic virus (CMV) is a prevalent virus affecting the quality and yield of pepper, resulting in yield losses of greater than 80% during severe local epidemics. Cultural practices and the heavy use of agrochemicals are the most common control measures for CMV. Sources of resistance provide a practical reference and a basis for breeding for CMV resistance. Genetic factors underlying CMV resistance have been studied and advanced breeding lines and cultivars with improved resistance have been developed by traditional breeding methods. Additionally, QTLs or genes for CMV resistance have been identified and can be utilized for marker-assisted resistance breeding. This review focuses on status and prospect of CMV against different virus strains, host resistance, and its applied genetics. With the advent of novel technologies, more useful markers and precise approaches can facilitate the progress for improving CMV resistance in Capsicum.
Collapse
Affiliation(s)
| | | | | | | | | | - Chunhai Jiao
- Hubei Key Laboratory of Vegetable Germplasm Innovation and Genetic Improvement, Cash Crops Research Institute, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Minghua Yao
- Hubei Key Laboratory of Vegetable Germplasm Innovation and Genetic Improvement, Cash Crops Research Institute, Hubei Academy of Agricultural Sciences, Wuhan, China
| |
Collapse
|
17
|
Freire MÁ. Viral silencing suppressors and cellular proteins partner with plant RRP6-like exoribonucleases. Virus Genes 2020; 56:621-631. [PMID: 32519287 DOI: 10.1007/s11262-020-01775-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 06/02/2020] [Indexed: 10/24/2022]
Abstract
RNA silencing and RNA decay are functionally interlaced, regulate gene expression and play a pivotal role in antiviral responses. As a counter-defensive strategy, many plant and mammalian viruses encode suppressors which interfere with both mechanisms. However, the protein interactions that connect these pathways remain elusive. Previous work reported that RNA silencing suppressors from different potyviruses, together with translation initiation factors EIF(iso)4E, interacted with the C-terminal region of the tobacco exoribonuclease RRP6-like 2, a component of the RNA decay exosome complex. Here, we investigate whether other viral silencing suppressors and cellular proteins might also bind RRP6-like exoribonucleases. A candidate search approach based on yeast two-hybrid protein interaction assays showed that three other unrelated viral suppressors, two from plant viruses and one from a mammalian virus, bound the C-terminus of the tobacco RRP6-like 2, the full-length of the Arabidopsis RRP6L1 protein and its C-terminal region. In addition, RRP6-like proteins were found to interact with members of the cellular double-stranded RNA-binding protein (DRB) family involved in RNA silencing. The C-terminal regions of RRP6L proteins are engaged in homotypic and heterotypic interactions and were predicted to be disordered. Collectively, these results suggest a protein interaction network that connects components of RNA decay and RNA silencing that is targeted by viral silencing suppressors.
Collapse
Affiliation(s)
- Miguel Ángel Freire
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), CONICET, Universidad Nacional de Córdoba (UNC), Av. Vélez Sarsfield 299, CC 495, 5000, Córdoba, Argentina.
| |
Collapse
|
18
|
Davino S, Ruiz-Ruiz S, Serra P, Forment J, Flores R. Revisiting the cysteine-rich proteins encoded in the 3'-proximal open reading frame of the positive-sense single-stranded RNA of some monopartite filamentous plant viruses: functional dissection of p15 from grapevine virus B. Arch Virol 2020; 165:2229-2239. [PMID: 32676682 DOI: 10.1007/s00705-020-04729-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/09/2020] [Indexed: 10/23/2022]
Abstract
A reexamination of proteins with conserved cysteines and basic amino acids encoded by the 3'-proximal gene of the positive-sense single-stranded RNA of some monopartite filamentous plant viruses has been carried out. The cysteines are involved in a putative Zn-finger domain, which, together with the basic amino acids, form part of the nuclear or nucleolar localization signals. An in-depth study of one of these proteins, p15 from grapevine B virus (GVB), has shown: (i) a three-dimensional structure with four α-helices predicted by two independent in silico approaches, (ii) the nucleolus as the main accumulation site by applying confocal laser microscopy to a fusion between p15 and the green fluorescent protein, (iii) the involvement of the basic amino acids and the putative Zn-finger domain, mapping at the N-terminal region of p15, in the nucleolar localization signal, as revealed by the effect of six alanine substitution mutations, (iv) the p15 suppressor function of sense-mediated RNA silencing as revealed by agroinfiltration in a transgenic line of Nicotiana benthamiana, and (v) the enhancer activity of p15 on viral pathogenicity in N. benthamiana when expressed from a potato virus X vector. In addition, we elaborate on an evolutionary scenario for these filamentous viruses, invoking takeover by a common ancestor(s) of viral or host genes coding for those cysteine-rich proteins, followed by divergence, which would also explain why they are encoded in the 3'-proximal gene of the genomic single-stranded viral RNA.
Collapse
Affiliation(s)
- Salvatore Davino
- Instituto de Biologia Molecular y Celular de Plantas (UPV-CSIC), Universidad Politécnica de Valencia, Avenida de los Naranjos, 46022, Valencia, Spain
- Department of Agricultural, Food and Forest Sciences, University of Palermo, Viale delle Scienze Building 5, 90128, Palermo, Italy
| | - Susana Ruiz-Ruiz
- Instituto de Biologia Molecular y Celular de Plantas (UPV-CSIC), Universidad Politécnica de Valencia, Avenida de los Naranjos, 46022, Valencia, Spain
| | - Pedro Serra
- Instituto de Biologia Molecular y Celular de Plantas (UPV-CSIC), Universidad Politécnica de Valencia, Avenida de los Naranjos, 46022, Valencia, Spain
| | - Javier Forment
- Instituto de Biologia Molecular y Celular de Plantas (UPV-CSIC), Universidad Politécnica de Valencia, Avenida de los Naranjos, 46022, Valencia, Spain
| | - Ricardo Flores
- Instituto de Biologia Molecular y Celular de Plantas (UPV-CSIC), Universidad Politécnica de Valencia, Avenida de los Naranjos, 46022, Valencia, Spain.
| |
Collapse
|
19
|
Aphid Transmission of Potyvirus: The Largest Plant-Infecting RNA Virus Genus. Viruses 2020; 12:v12070773. [PMID: 32708998 PMCID: PMC7411817 DOI: 10.3390/v12070773] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/12/2020] [Accepted: 07/15/2020] [Indexed: 12/15/2022] Open
Abstract
Potyviruses are the largest group of plant infecting RNA viruses that cause significant losses in a wide range of crops across the globe. The majority of viruses in the genus Potyvirus are transmitted by aphids in a non-persistent, non-circulative manner and have been extensively studied vis-à-vis their structure, taxonomy, evolution, diagnosis, transmission, and molecular interactions with hosts. This comprehensive review exclusively discusses potyviruses and their transmission by aphid vectors, specifically in the light of several virus, aphid and plant factors, and how their interplay influences potyviral binding in aphids, aphid behavior and fitness, host plant biochemistry, virus epidemics, and transmission bottlenecks. We present the heatmap of the global distribution of potyvirus species, variation in the potyviral coat protein gene, and top aphid vectors of potyviruses. Lastly, we examine how the fundamental understanding of these multi-partite interactions through multi-omics approaches is already contributing to, and can have future implications for, devising effective and sustainable management strategies against aphid-transmitted potyviruses to global agriculture.
Collapse
|
20
|
Leastro MO, Castro DYO, Freitas-Astúa J, Kitajima EW, Pallás V, Sánchez-Navarro JÁ. Citrus Leprosis Virus C Encodes Three Proteins With Gene Silencing Suppression Activity. Front Microbiol 2020; 11:1231. [PMID: 32655520 PMCID: PMC7325951 DOI: 10.3389/fmicb.2020.01231] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 05/14/2020] [Indexed: 01/12/2023] Open
Abstract
Citrus leprosis virus C (CiLV-C) belongs to the genus Cilevirus, family Kitaviridae, and is considered the most devastating virus infecting citrus in Brazil, being the main viral pathogen responsible for citrus leprosis (CL), a severe disease that affects citrus orchards in Latin America. Here, proteins encoded by CiLV-C genomic RNA 1 and 2 were screened for potential RNA silencing suppressor (RSS) activity by five methods. Using the GFP-based reporter agroinfiltration assay, we have not found potential local suppressor activity for the five CiLV-C encoded proteins. However, when RSS activity was evaluated using the alfalfa mosaic virus (AMV) system, we found that the p29, p15, and p61 CiLV-C proteins triggered necrosis response and increased the AMV RNA 3 accumulation, suggesting a suppressive functionality. From the analysis of small interfering RNAs (siRNAs) accumulation, we observed that the ectopic expression of the p29, p15, and p61 reduced significantly the accumulation of GFP derived siRNAs. The use of the RSS defective turnip crinkle virus (TCV) system revealed that only the trans-expression of the p15 protein restored the cell-to-cell viral movement. Finally, the potato virus X (PVX) system revealed that the expression of p29, p15, and p61 increased the PVX RNA accumulation; in addition, the p29 and p15 enhanced the pathogenicity of PVX resulting in the death of tobacco plants. Furthermore, PVX-p61 infection resulted in a hypersensitive response (HR), suggesting that p61 could also activate a plant defense response mechanism. This is the first report describing the RSS activity for CiLV-C proteins and, moreover, for a member of the family Kitaviridae.
Collapse
Affiliation(s)
- Mikhail Oliveira Leastro
- Unidade Laboratorial de Referência em Biologia Molecular Aplicada, Instituto Biológico, São Paulo, Brazil.,Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científcas (CSIC), Valencia, Spain
| | - Deibis Yorlenis Ortega Castro
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científcas (CSIC), Valencia, Spain
| | - Juliana Freitas-Astúa
- Unidade Laboratorial de Referência em Biologia Molecular Aplicada, Instituto Biológico, São Paulo, Brazil.,Embrapa Mandioca e Fruticultura, Cruz das Almas, Brazil
| | - Elliot Watanabe Kitajima
- Departamento de Fitopatologia e Nematologia, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, Brazil
| | - Vicente Pallás
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científcas (CSIC), Valencia, Spain
| | - Jesús Ángel Sánchez-Navarro
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científcas (CSIC), Valencia, Spain
| |
Collapse
|
21
|
Characterization of distinct strains of an aphid-transmitted ilarvirus (Fam. Bromoviridae) infecting different hosts from South America. Virus Res 2020; 282:197944. [PMID: 32222379 PMCID: PMC7221344 DOI: 10.1016/j.virusres.2020.197944] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 02/08/2020] [Accepted: 03/21/2020] [Indexed: 11/22/2022]
Abstract
Thirteen complete genomes and 25 partial sequences of PYV from potato and yacon collected in Ecuador, Peru, Bolivia and a UK interception. Analysis suggests potato isolates originated via acquisition of the movement protein from a related virus through recombination. Most yacon isolates and potato isolates from Peru and Ecuador could be distinguished through infectivity and symptoms in different hosts.
Potato yellowing virus (PYV, original code SB-22), an unassigned member of the Genus Ilarvirus Family Bromoviridae, has been reported infecting potatoes in Peru, Ecuador and Chile. It is associated with symptomless infections, however yellowing of young leaves has been observed in some potato cultivars. Thirteen potato and yacon isolates were selected after routine screening of CIP-germplasm and twenty-four were identified from 994 potato plants collected in Peru whereas one was intercepted from yacon in the UK. These isolates were identified using high throughput sequencing, ELISA, host range and RT-PCR. Here we report the sequence characterization of the complete genomes of nine PYV isolates found infecting Solanum tuberosum, four complete genome isolates infecting Smallanthus sonchifolius (yacon), and in addition 15 complete RNA3 sequences from potato and partial sequences of RNA1, 2 and 3 of isolates infecting potato and yacon from Ecuador, Peru and Bolivia. Results of phylogenetic and recombination analysis showed RNA3 to be the most variable among the virus isolates and suggest potato infecting isolates have resulted through acquisition of a movement protein variant through recombination with an unknown but related ilarvirus, whereas one yacon isolate from Bolivia also had resulted from a recombination event with another related viruses in the same region. Yacon isolates could be distinguished from potato isolates by their inability to infect Physalis floridana, and potato isolates from Ecuador and Peru could be distinguished by their symptomatology in this host as well as phylogenetically. The non-recombinant yacon isolates were closely related to a recently described isolate from Solanum muricatum (pepino dulce), and all isolates were related to Fragaria chiloensis latent virus (FCiLV) reported in strawberry from Chile, and probably should be considered the same species. Although PYV is not serologically related to Alfalfa mosaic virus (AMV), they are both transmitted by aphids and share several other characteristics that support the previous suggestion to reclassify AMV as a member in the genus Ilarvirus.
Collapse
|
22
|
Ala-Poikela M, Rajamäki ML, Valkonen JP. A Novel Interaction Network Used by Potyviruses in Virus-Host Interactions at the Protein Level. Viruses 2019; 11:E1158. [PMID: 31847316 PMCID: PMC6950583 DOI: 10.3390/v11121158] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 12/30/2022] Open
Abstract
Host proteins that are central to infection of potyviruses (genus Potyvirus; family Potyviridae) include the eukaryotic translation initiation factors eIF4E and eIF(iso)4E. The potyviral genome-linked protein (VPg) and the helper component proteinase (HCpro) interact with each other and with eIF4E and eIF(iso)4E and proteins are involved in the same functions during viral infection. VPg interacts with eIF4E/eIF(iso)4E via the 7-methylguanosine cap-binding region, whereas HCpro interacts with eIF4E/eIF(iso)4E via the 4E-binding motif YXXXXLΦ, similar to the motif in eIF4G. In this study, HCpro and VPg were found to interact in the nucleus, nucleolus, and cytoplasm in cells infected with the potyvirus potato virus A (PVA). In the cytoplasm, interactions between HCpro and VPg occurred in punctate bodies not associated with viral replication vesicles. In addition to HCpro, the 4E-binding motif was recognized in VPg of PVA. Mutations in the 4E-binding motif of VPg from PVA weakened interactions with eIF4E and heavily reduced PVA virulence. Furthermore, mutations in the 4G-binding domain of eIF4E reduced interactions with VPg and abolished interactions with HCpro. Thus, HCpro and VPg can both interact with eIF4E using the 4E-binding motif. Our results suggest a novel interaction network used by potyviruses to interact with host plants via translation initiation factors.
Collapse
Affiliation(s)
| | - Minna-Liisa Rajamäki
- Department of Agricultural Sciences, University of Helsinki, P.O. Box 27, FI-00014 Helsinki, Finland;
| | - Jari P.T. Valkonen
- Department of Agricultural Sciences, University of Helsinki, P.O. Box 27, FI-00014 Helsinki, Finland;
| |
Collapse
|
23
|
Evolutionary timescale and geographical movement of cucumber mosaic virus, with focus on Iranian strains. Arch Virol 2019; 165:185-192. [PMID: 31637514 DOI: 10.1007/s00705-019-04439-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 09/16/2019] [Indexed: 10/25/2022]
Abstract
Cucumber mosaic virus (CMV) is a geographically widespread plant virus with a very broad host range. The virus has been detected in diverse crops all over Iran. In this study, we estimated the timescale of the evolution of CMV subgroup I and the geographical movement of the virus with a focus on Iranian strains. Analyses using the MP and CP genes and their concatenation revealed that the CMV population within subgroup I had a single ancestor dating back to about 450-550 years ago. The Iranian strains formed three clusters in a maximum-clade-credibility phylogenetic tree. It was found that the most recent common ancestor of the Iranian strains within each cluster dates back to less than 100 years ago. Our results also suggest that both short- and long-distance migration of Iranian CMV strains has occurred in the last 100 years.
Collapse
|
24
|
Mortensen S, Bernal-Franco D, Cole LF, Sathitloetsakun S, Cram EJ, Lee-Parsons CWT. EASI Transformation: An Efficient Transient Expression Method for Analyzing Gene Function in Catharanthus roseus Seedlings. FRONTIERS IN PLANT SCIENCE 2019; 10:755. [PMID: 31263474 PMCID: PMC6585625 DOI: 10.3389/fpls.2019.00755] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/24/2019] [Indexed: 05/07/2023]
Abstract
The Catharanthus roseus plant is the exclusive source of the valuable anticancer terpenoid indole alkaloids, vinblastine (VB) and vincristine (VC). The recent availability of transcriptome and genome resources for C. roseus necessitates a fast and reliable method for studying gene function. In this study, we developed an Agrobacterium-mediated transient expression method to enable the functional study of genes rapidly in planta, conserving the compartmentalization observed in the VB and VC pathway. We focused on (1) improving the transformation method (syringe versus vacuum agroinfiltration) and cultivation conditions (seedling age, Agrobacterium density, and time point of maximum transgene expression), (2) improving transformation efficiency through the constitutive expression of the virulence genes and suppressing RNA silencing mechanisms, and (3) improving the vector design by incorporating introns, quantitative and qualitative reporter genes (luciferase and GUS genes), and accounting for transformation heterogeneity across the tissue using an internal control. Of all the parameters tested, vacuum infiltration of young seedlings (10-day-old, harvested 3 days post-infection) resulted in the strongest increase in transgene expression, at 18 - 57 fold higher than either vacuum or syringe infiltration of other seedling ages. Endowing the A. tumefaciens strain with the mutated VirGN54D or silencing suppressors within the same plasmid as the reporter gene further increased expression by 2 - 10 fold. For accurate measurement of promoter transactivation or activity, we included an internal control to normalize the differences in plant mass and transformation efficiency. Including the normalization gene (Renilla luciferase) on the same plasmid as the reporter gene (firefly luciferase) consistently yielded a high signal and a high correlation between RLUC and FLUC. As proof of principle, we applied this approach to investigate the regulation of the CroSTR1 promoter with the well-known activator ORCA3 and repressor ZCT1. Our method demonstrated the quantitative assessment of both the activation and repression of promoter activity in C. roseus. Our efficient Agrobacterium-mediated seedling infiltration (EASI) protocol allows highly efficient, reproducible, and homogenous transformation of C. roseus cotyledons and provides a timely tool for the community to rapidly assess the function of genes in planta, particularly for investigating how transcription factors regulate terpenoid indole alkaloid biosynthesis.
Collapse
Affiliation(s)
- Samuel Mortensen
- Department of Biology, Northeastern University, Boston, MA, United States
| | - Diana Bernal-Franco
- Department of Biology, Northeastern University, Boston, MA, United States
- Department of Chemical Engineering, Northeastern University, Boston, MA, United States
| | - Lauren F. Cole
- Department of Bioengineering, Northeastern University, Boston, MA, United States
| | - Suphinya Sathitloetsakun
- Department of Biology, Northeastern University, Boston, MA, United States
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Erin J. Cram
- Department of Biology, Northeastern University, Boston, MA, United States
| | - Carolyn W. T. Lee-Parsons
- Department of Chemical Engineering, Northeastern University, Boston, MA, United States
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| |
Collapse
|
25
|
Huang X, Yu R, Li W, Geng L, Jing X, Zhu C, Liu H. Identification and characterisation of a glycine-rich RNA-binding protein as an endogenous suppressor of RNA silencing from Nicotiana glutinosa. PLANTA 2019; 249:1811-1822. [PMID: 30840177 DOI: 10.1007/s00425-019-03122-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 02/27/2019] [Indexed: 05/08/2023]
Abstract
MAIN CONCLUSION This study shows that NgRBP suppresses both local and systemic RNA silencing induced by sense- or double-stranded RNA, and the RNA binding activity is essential for its function. To counteract host defence, many plant viruses encode viral suppressors of RNA silencing targeting various stages of RNA silencing. There is increasing evidence that the plants also encode endogenous suppressors of RNA silencing (ESR) to regulate this pathway. In this study, using Agrobacterium infiltration assays, we characterized NgRBP, a glycine-rich RNA-binding protein from Nicotiana glutinosa, as an ESR. Our results indicated that NgRBP suppressed both local and systemic RNA silencing induced by sense- or double-stranded RNA. We also demonstrated that NgRBP could promote Potato Virus X (PVX) infection in N. benthamiana. NgRBP knockdown by virus-induced gene silencing enhanced PVX and Cucumber mosaic virus resistance in N. glutinosa. RNA immunoprecipitation and electrophoretic mobility shift assays showed that NgRBP bound to GFP mRNA, dsRNA rather than siRNA. These findings provide the evidence that NgRBP acts as an ESR and the RNA affinity of NgRBP plays the key role in its ESR activity. NgRBP responds to multiple signals such as ABA, MeJA, SA, and Tobacco mosaic virus infection. Therefore, it could participate in the regulation of gene expression under specific conditions.
Collapse
Affiliation(s)
- Xu Huang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, China
| | - Ru Yu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, China
| | - Wenjing Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, China
| | - Liwei Geng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, China
| | - Xiuli Jing
- Institute of Immunology, Taishan Medical University, Tai'an, Shandong, China
| | - Changxiang Zhu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, China
| | - Hongmei Liu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
| |
Collapse
|
26
|
Bak A, Patton MF, Perilla-Henao LM, Aegerter BJ, Casteel CL. Ethylene signaling mediates potyvirus spread by aphid vectors. Oecologia 2019; 190:139-148. [DOI: 10.1007/s00442-019-04405-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 04/22/2019] [Indexed: 12/21/2022]
|
27
|
Turnip Mosaic Virus Is a Second Example of a Virus Using Transmission Activation for Plant-to-Plant Propagation by Aphids. J Virol 2019; 93:JVI.01822-18. [PMID: 30760573 DOI: 10.1128/jvi.01822-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 02/06/2019] [Indexed: 12/16/2022] Open
Abstract
Cauliflower mosaic virus (CaMV; family Caulimoviridae) responds to the presence of aphid vectors on infected plants by forming specific transmission morphs. This phenomenon, coined transmission activation (TA), controls plant-to-plant propagation of CaMV. A fundamental question is whether other viruses rely on TA. Here, we demonstrate that transmission of the unrelated turnip mosaic virus (TuMV; family Potyviridae) is activated by the reactive oxygen species H2O2 and inhibited by the calcium channel blocker LaCl3 H2O2-triggered TA manifested itself by the induction of intermolecular cysteine bonds between viral helper component protease (HC-Pro) molecules and by the formation of viral transmission complexes, composed of TuMV particles and HC-Pro that mediates vector binding. Consistently, LaCl3 inhibited intermolecular HC-Pro cysteine bonds and HC-Pro interaction with viral particles. These results show that TuMV is a second virus using TA for transmission but using an entirely different mechanism than CaMV. We propose that TuMV TA requires reactive oxygen species (ROS) and calcium signaling and that it is operated by a redox switch.IMPORTANCE Transmission activation, i.e., a viral response to the presence of vectors on infected hosts that regulates virus acquisition and thus transmission, is an only recently described phenomenon. It implies that viruses contribute actively to their transmission, something that has been shown before for many other pathogens but not for viruses. However, transmission activation has been described so far for only one virus, and it was unknown whether other viruses also rely on transmission activation. Here we present evidence that a second virus uses transmission activation, suggesting that it is a general transmission strategy.
Collapse
|
28
|
Structural analysis of Phytophthora suppressor of RNA silencing 2 (PSR2) reveals a conserved modular fold contributing to virulence. Proc Natl Acad Sci U S A 2019; 116:8054-8059. [PMID: 30926664 DOI: 10.1073/pnas.1819481116] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Phytophthora are eukaryotic pathogens that cause enormous losses in agriculture and forestry. Each Phytophthora species encodes hundreds of effector proteins that collectively have essential roles in manipulating host cellular processes and facilitating disease development. Here we report the crystal structure of the effector Phytophthora suppressor of RNA silencing 2 (PSR2). PSR2 produced by the soybean pathogen Phytophthora sojae (PsPSR2) consists of seven tandem repeat units, including one W-Y motif and six L-W-Y motifs. Each L-W-Y motif forms a highly conserved fold consisting of five α-helices. Adjacent units are connected through stable, directional linkages between an internal loop at the C terminus of one unit and a hydrophobic pocket at the N terminus of the following unit. This unique concatenation results in an overall stick-like structure of PsPSR2. Genome-wide analyses reveal 293 effectors from five Phytophthora species that have the PsPSR2-like arrangement, that is, containing a W-Y motif as the "start" unit, various numbers of L-W-Y motifs as the "middle" units, and a degenerate L-W-Y as the "end" unit. Residues involved in the interunit interactions show significant conservation, suggesting that these effectors also use the conserved concatenation mechanism. Furthermore, functional analysis demonstrates differential contributions of individual units to the virulence activity of PsPSR2. These findings suggest that the L-W-Y fold is a basic structural and functional module that may serve as a "building block" to accelerate effector evolution in Phytophthora.
Collapse
|
29
|
Cong QQ, Wang Y, Liu J, Lan YF, Guo ZK, Yang JG, Li XD, Tian YP. Evaluation of Potato virus X mild mutants for cross protection against severe infection in China. Virol J 2019; 16:36. [PMID: 30894176 PMCID: PMC6425663 DOI: 10.1186/s12985-019-1143-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 03/12/2019] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Cross protection is a promising alternative to control plant viral diseases. One critical factor limiting the application of cross protection is the availability of attenuated mutants or mild strains. Potato virus X (PVX) infects many crops and induces huge economic losses to agricultural production. However, researches on the variability and mechanism of PVX virulence are scarce. METHODS The mutants were obtained by introducing mutations into the RNA dependent RNA polymerase (RdRp) gene of PVX via site-directed mutagenesis. Attenuated mutants were screen according to their symptoms in Nicotiana benthamiana plants. The protection efficacy against severe infection were evaluated with interval of 5, 10 and 15 days. RESULTS Among the 40 mutants obtained, four mutants carrying substitutions of either Glu46, Asn863, Asn968 or Glu1001 to Ala in PVX RdRp showed drastically attenuated symptom, accompanying with reduced accumulation levels of coat protein, plus- and minus-sense RNAs. When the interval between protective and challenging inoculations was 15 days, mutant E1001A (with substitution of Glu1001 to Ala in RdRp) provided complete protection against severe infection in both Nicotiana benthamiana and tomato, while E46A (Glu46 mutated to Ala) provided incomplete protection. To reduce the risk of reverse mutation, we constructed mutant dM which carries double mutations of both Glu46 and Glu1001 to Ala in RdRp. The mutant dM could provide effective protection against severe PVX infection. CONCLUSION Mutations of Glu46, Asn863, Asn968 or Glu1001 to Ala in PVX RdRp significantly reduced the viral symptoms. Mutants E1001A and E46A could provide effective protection against wild type PVX in both Nicotiana benthamiana and tomato. These results provide theoretical and practical bases for the control of PVX via cross protection.
Collapse
Affiliation(s)
- Q. Q. Cong
- Shandong Province Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018 People’s Republic of China
- Key Laboratory of Tobacco Pest Monitoring Controlling & Integrated Management, Qingdao, 266101 China
- Tai’an Academy of Agricultural Sciences, Tai’an, 271000 Shandong China
| | - Y. Wang
- Shandong Province Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018 People’s Republic of China
| | - J. Liu
- Shandong Province Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018 People’s Republic of China
| | - Y. F. Lan
- Tai’an Academy of Agricultural Sciences, Tai’an, 271000 Shandong China
| | - Z. K. Guo
- Heilongjiang Academy of Agricultural Sciences, Mudanjiang, 157011 Heilongjiang China
| | - J. G. Yang
- Key Laboratory of Tobacco Pest Monitoring Controlling & Integrated Management, Qingdao, 266101 China
| | - X.-D. Li
- Shandong Province Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018 People’s Republic of China
| | - Y. P. Tian
- Shandong Province Key Laboratory of Agricultural Microbiology, Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai’an, Shandong 271018 People’s Republic of China
| |
Collapse
|
30
|
Lu QY, Yang L, Huang J, Zheng L, Sun X. Identification and subcellular location of an RNA silencing suppressor encoded by mulberry crinkle leaf virus. Virology 2019; 526:45-51. [PMID: 30342301 DOI: 10.1016/j.virol.2018.10.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 10/04/2018] [Accepted: 10/04/2018] [Indexed: 11/28/2022]
Abstract
Mulberry crinkle leaf virus (MCLV) is a novel geminivirus recently identified from the woody plant mulberry (Morus alba L.). Little is known about the functions of the proteins encoded by the MCLV genome. Here, all the MCLV-encoded proteins were examined for the ability to suppress gene silencing by an agroinfiltration assay in combination with northern blot analysis of green fluorescent protein (GFP) mRNA and western blot analysis. Of the six proteins, only one protein, V3, which has been predicted to play a role in viral movement, was found to suppress the gene silencing induced by a sense GFP gene in Nicotiana benthamiana 16c. The minimal amino acid sequence of V3 that maintains suppressor activity was also determined by constructing truncated mutants lacking different lengths of the amino acid sequences at the N- or C-terminus of the V3 protein. The results showed that the 94 N-terminal amino acid residues of V3 are sufficient to maintain V3 suppressor activity. In addition, the subcellular location of the V3 protein was investigated by confocal laser scanning microscopy after the expression of a V3-RFP fused protein in leaf epidermal cells of N. benthamiana. The results indicated that the V3 protein localized not only to the cytoplasm but also to the nucleus of N. benthamiana, implying that V3 can shuttle between the nucleus and the cytoplasm. Deletion mutant analysis indicated that a putative nuclear localization signal (NLS) between aa 118-134 might be responsible for the nuclear distribution of the V3 protein. Given the importance of RNA silencing in plant-virus interactions, the identification of a silencing suppressor of MCLV should be valuable in understanding the pathogenicity and molecular biology of this virus.
Collapse
Affiliation(s)
- Quan-You Lu
- The Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China; Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China.
| | - Lei Yang
- The Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China; Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China
| | - Jinshan Huang
- The Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China; Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China
| | - Luping Zheng
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Xin Sun
- The Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China; Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China
| |
Collapse
|
31
|
Li S, Hu Y, Jiang L, Rui P, Zhao Q, Feng J, Zuo D, Zhou X, Jiang T. Strawberry Vein Banding Virus P6 Protein Is a Translation Trans-Activator and Its Activity Can be Suppressed by FveIF3g. Viruses 2018; 10:E717. [PMID: 30558257 PMCID: PMC6316418 DOI: 10.3390/v10120717] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 12/06/2018] [Accepted: 12/13/2018] [Indexed: 01/25/2023] Open
Abstract
The strawberry vein banding virus (SVBV) open reading frame (ORF) VI encodes a P6 protein known as the RNA silencing suppressor. This protein is known to form inclusion like granules of various sizes and accumulate in both the nuclei and the cytoplasm of SVBV-infected plant cells. In this study, we have determined that the P6 protein is the only trans-activator (TAV) encoded by SVBV, and can efficiently trans-activate the translation of downstream gfp mRNA in a bicistron derived from the SVBV. Furthermore, the P6 protein can trans-activate the expression of different bicistrons expressed by different caulimovirus promoters. The P6 protein encoded by SVBV from an infectious clone can also trans-activate the expression of bicistron. Through protein-protein interaction assays, we determined that the P6 protein could interact with the cell translation initiation factor FveIF3g of Fragaria vesca and co-localize with it in the nuclei of Nicotiana benthamiana cells. This interaction reduced the formation of P6 granules in cells and its trans-activation activity on translation.
Collapse
Affiliation(s)
- Shuai Li
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
| | - Yahui Hu
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
| | - Lei Jiang
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
| | - Penghuan Rui
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
| | - Qingqing Zhao
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
| | - Jiying Feng
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
| | - Dengpan Zuo
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
| | - Xueping Zhou
- State Key Laboratory for Plant Disease and Insect Pest, Institute of Plant protection, China Academy of Agricultural Sciences, Beijing 100193, China.
| | - Tong Jiang
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
| |
Collapse
|
32
|
Abstract
Mealybug wilt of pineapple (MWP) is a disease of pineapple that has a long history in Hawaii, but is present throughout the world where pineapples are grown in tropical regions. The disease has an interesting etiology that is poorly understood but involves an association with virus particles, mealybug vectors, and ants which spread the mealybug vectors. Several distinct pineapple mealybug wilt-associated virus (PMWaV) species have been identified thus far with potential further member species yet to be characterized. Pineapple mealybug wilt-associated viruses are member species of the Ampelovirus genus of the Closteroviridae family. Ampeloviruses are split into two subgroups, subgroup I and subgroup II. PMWaV-2 is a subgroup II member, and these have a longer and more complex genome with additional genes on the 3’ terminus of the RNA genome compared to subgroup I ampeloviruses. PMWaV-2, along with the presence of mealybug vectors, have been shown to be necessary factors in symptom development in Hawaii. Some of these extra genes in the 3’ of PMWaV-2 have recently been shown to function as silencing suppressors, and may play a role in the virulence of PMWaV-2 and symptom development. In other regions of the world, reports of symptomatic plants without PMWaV-2 infection, but with PMWaV-1, -3 or some combination, contradict the requirement of PMWaV-2 for symptom development in MWP. It is possible that further, uncharacterized PMWaVs may be present in symptomatic pineapple plants that test negative for PMWaV-2, explaining the inconsistency in symptom development. More research is necessary to explore the confusing etiology of the MWP disease, and to perhaps shed light upon the symptom development.
Collapse
|
33
|
Varanda CM, Materatski P, Campos MD, Clara MIE, Nolasco G, Félix MDR. Olive Mild Mosaic Virus Coat Protein and P6 Are Suppressors of RNA Silencing, and Their Silencing Confers Resistance against OMMV. Viruses 2018; 10:E416. [PMID: 30096871 PMCID: PMC6115721 DOI: 10.3390/v10080416] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/03/2018] [Accepted: 08/06/2018] [Indexed: 12/16/2022] Open
Abstract
RNA silencing is an important defense mechanism in plants, yet several plant viruses encode proteins that suppress this mechanism. In this study, the genome of the Olive mild mosaic virus (OMMV) was screened for silencing suppressors. The full OMMV cDNA and 5 OMMV open reading frames (ORFs) were cloned into the Gateway binary vector pK7WG2, transformed into Agrobacterium tumefaciens, and agroinfiltrated into N. benthamiana 16C plants. CP and p6 showed suppressor activity, with CP showing significantly higher activity than p6, yet activity that was lower than the full OMMV, suggesting a complementary action of CP and p6. These viral suppressors were then used to induce OMMV resistance in plants based on RNA silencing. Two hairpin constructs targeting each suppressor were agroinfiltrated in N. benthamiana plants, which were then inoculated with OMMV RNA. When silencing of both suppressors was achieved, a significant reduction in viral accumulation and symptom attenuation was observed as compared to those of the controls, as well as to when each construct was used alone, proving them to be effective against OMMV infection. This is the first time that a silencing suppressor was found in a necrovirus, and that two independent proteins act as silencing suppressors in a virus member of the Tombusviridae family.
Collapse
Affiliation(s)
- Carla Mr Varanda
- ICAAM-Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Instituto de Investigação e Formação Avançada, Universidade de Évora, Pólo da Mitra, Ap.94, 7006-554 Évora, Portugal.
| | - Patrick Materatski
- ICAAM-Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Instituto de Investigação e Formação Avançada, Universidade de Évora, Pólo da Mitra, Ap.94, 7006-554 Évora, Portugal.
| | - Maria Doroteia Campos
- ICAAM-Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Instituto de Investigação e Formação Avançada, Universidade de Évora, Pólo da Mitra, Ap.94, 7006-554 Évora, Portugal.
| | - Maria Ivone E Clara
- Departamento de Fitotecnia, ICAAM-Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Escola de Ciências e Tecnologia, Universidade de Évora, Pólo da Mitra, Ap.94, 7006-554 Évora, Portugal.
| | - Gustavo Nolasco
- MeditBio-Centro para os Recursos Biológicos e Alimentos Mediterrânicos, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
| | - Maria do Rosário Félix
- Departamento de Fitotecnia, ICAAM-Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Escola de Ciências e Tecnologia, Universidade de Évora, Pólo da Mitra, Ap.94, 7006-554 Évora, Portugal.
| |
Collapse
|
34
|
Wang F, Zhao X, Dong Q, Zhou B, Gao Z. Characterization of an RNA silencing suppressor encoded by maize yellow dwarf virus-RMV2. Virus Genes 2018; 54:570-577. [PMID: 29752617 DOI: 10.1007/s11262-018-1565-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 04/27/2018] [Indexed: 12/19/2022]
Abstract
Maize yellow dwarf virus-RMV2 (MYDV-RMV2) causes dwarfing and yellowing symptoms on leaves in field-grown maize plants in Anhui province in China. Herein, we evaluated the RNA silencing suppressor (RSS) activity of the P0 protein from MYDV-RMV2 by co-infiltration assays using wild-type and GFP-transgenic Nicotiana benthamiana (line 16C). The P0 of MYDV-RMV2 exhibited RSS activity and inhibited RNA silencing both locally and systemically. MYDV-RMV2 P0 acts as an F-box-like motif, and mutations to Ala at positions 67, 68, and 81 in the F-box-like motif (67LPxx81P) abolished the RSS activity of P0. However, MYDV-RMV2 P0 failed to interact with AGO1 from Arabidopsis thaliana. Expressing P0 induced developmental defects. P0 was targeted to both the nuclei and cytoplasm of plant cells. These findings expand our knowledge of the role of polerovirus P0 proteins in RNA silencing.
Collapse
Affiliation(s)
- Fang Wang
- Tobacco Research Institute, Anhui Academy of Agricultural Sciences, Hefei, 230031, Anhui, China
| | - Xia Zhao
- Cereal Institute, Henan Academy of Agricultural Sciences/Henan Provincial Key Laboratory of Maize Biology, Zhengzhou, 450002, Henan, China
| | - Qing Dong
- Tobacco Research Institute, Anhui Academy of Agricultural Sciences, Hefei, 230031, Anhui, China
| | - Benguo Zhou
- Tobacco Research Institute, Anhui Academy of Agricultural Sciences, Hefei, 230031, Anhui, China
| | - Zhengliang Gao
- Tobacco Research Institute, Anhui Academy of Agricultural Sciences, Hefei, 230031, Anhui, China.
| |
Collapse
|
35
|
Abstract
Viruses are an important but sequence-diverse and often understudied component of the phytobiome. We succinctly review current information on how plant viruses directly affect plant health and physiology and consequently have the capacity to modulate plant interactions with their biotic and abiotic environments. Virus interactions with other biota in the phytobiome, including arthropods, fungi, and nematodes, may also impact plant health. For example, viruses interact with and modulate the interface between plants and insects. This has been extensively studied for insect-vectored plant viruses, some of which also infect their vectors. Other viruses have been shown to alter the impacts of plant-interacting phytopathogenic and nonpathogenic fungi and bacteria. Viruses that infect nematodes have also recently been discovered, but the impact of these and phage infecting soil bacteria on plant health remain largely unexplored.
Collapse
Affiliation(s)
- James E Schoelz
- Division of Plant Sciences, University of Missouri, Columbia, Missouri 65211, USA
| | - Lucy R Stewart
- Corn, Soybean and Wheat Quality Research Unit, United States Department of Agriculture Agricultural Research Service (USDA-ARS), Wooster, Ohio 44691, USA;
| |
Collapse
|
36
|
Feng M, Zuo D, Jiang X, Li S, Chen J, Jiang L, Zhou X, Jiang T. Identification of Strawberry vein banding virus encoded P6 as an RNA silencing suppressor. Virology 2018; 520:103-110. [PMID: 29843054 DOI: 10.1016/j.virol.2018.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 05/04/2018] [Accepted: 05/07/2018] [Indexed: 11/25/2022]
Abstract
RNA silencing is a common mechanism that plays a key role in antiviral defense. To overcome host defense responses, plant viruses encode silencing-suppressor proteins to target one or several key steps in the silencing machinery. Here, we report that the P6 protein encoded by Strawberry vein banding virus (SVBV) is an RNA silencing suppressor through Agrobacterium-mediated co-infiltration assays. SVBV P6 protein can suppress green fluorescent protein (GFP) gene silencing induced by single-stranded RNA but not by double-stranded RNA. The P6 protein can also inhibit systemic silencing of GFP through interfering the systemic spread of GFP silencing signal. Subcellular localization study indicated that P6 protein formed irregular bodies and distributed in both cytoplasm and nucleus of Nicotiana benthamiana cells. Furthermore, deletion analysis indicated that a nuclear localization signal (NLS, aa 402-426) in the P6 protein is responsible for the silencing suppression efficiency. In addition, expression of the P6 protein via a Potato virus X (PVX)-based vectors induced more severe mosaic symptoms in N. benthamiana leaves, and transgenic N. benthamiana plants expressing P6 showed obvious vein yellowing as well as severe mosaic symptoms in leaves. Taken together, our results demonstrates that SVBV P6 is a suppressor of RNA silencing, possibly acting at a upstream step for dsRNA generation.
Collapse
Affiliation(s)
- Mingfeng Feng
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Dengpan Zuo
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Xizi Jiang
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Shuai Li
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Jing Chen
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Lei Jiang
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Xueping Zhou
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
| | - Tong Jiang
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of China.
| |
Collapse
|
37
|
Yu R, Jing X, Li W, Xu J, Xu Y, Geng L, Zhu C, Liu H. Non-structural protein 1 from avian influenza virus H9N2 is an efficient RNA silencing suppressor with characteristics that differ from those of Tomato bushy stunt virus p19. Virus Genes 2018; 54:368-375. [PMID: 29480423 DOI: 10.1007/s11262-018-1544-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 02/19/2018] [Indexed: 10/17/2022]
Abstract
Non-structural protein 1 (NS1) of influenza A virus is a multifunctional dimeric protein that contains a conserved N-terminal RNA binding domain. Studies have shown that NS1 suppresses RNA silencing and the NS1 proteins encoded by different influenza A virus strains exhibit differential RNA silencing suppression activities. In this study, we showed that the NS1 protein from avian influenza virus (AIV) H9N2 suppressed systemic RNA silencing induced by sense RNA or dsRNA. It resulted in more severe Potato virus X symptom, but could not reverse established systemic green fluorescent protein silencing in Nicotiana benthamiana. In addition, its systemic silencing suppression activity was much weaker than that of p19. The local silencing suppression activity of AIV H9N2 NS1 was most powerful at 7 dpi and was even stronger than that of p19. And the inhibition ability to RNA silencing of NS1 is stronger than that of p19 in human cells. Collectively, these results indicate that AIV H9N2 NS1 is an effective RNA silencing suppressor that likely targets downstream step(s) of dsRNA formation at an early stage in RNA silencing. Although NS1 and p19 both bind siRNA, their suppression mechanisms seem to differ because of differences in their suppression activities at various times post-infiltration and because p19 can reverse established systemic RNA silencing, but NS1 cannot.
Collapse
Affiliation(s)
- Ru Yu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Xiuli Jing
- Institute of Immunology, Taishan Medical University, Tai'an, 271000, China
| | - Wenjing Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Jie Xu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Yang Xu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Liwei Geng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Changxiang Zhu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Hongmei Liu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China.
| |
Collapse
|
38
|
Huang TK, Falk BW, Dandekar AM, McDonald KA. Enhancement of Recombinant Protein Production in Transgenic Nicotiana benthamiana Plant Cell Suspension Cultures with Co-Cultivation of Agrobacterium Containing Silencing Suppressors. Int J Mol Sci 2018; 19:E1561. [PMID: 29882931 PMCID: PMC6032394 DOI: 10.3390/ijms19061561] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/06/2018] [Accepted: 05/18/2018] [Indexed: 11/16/2022] Open
Abstract
We have previously demonstrated that the inducible plant viral vector (CMViva) in transgenic plant cell cultures can significantly improve the productivity of extracellular functional recombinant human alpha-1-antiryspin (rAAT) compared with either a common plant constitutive promoter (Cauliflower mosaic virus (CaMV) 35S) or a chemically inducible promoter (estrogen receptor-based XVE) system. For a transgenic plant host system, however, viral or transgene-induced post-transcriptional gene silencing (PTGS) has been identified as a host response mechanism that may dramatically reduce the expression of a foreign gene. Previous studies have suggested that viral gene silencing suppressors encoded by a virus can block or interfere with the pathways of transgene-induced PTGS in plant cells. In this study, the capability of nine different viral gene silencing suppressors were evaluated for improving the production of rAAT protein in transgenic plant cell cultures (CMViva, XVE or 35S system) using an Agrobacterium-mediated transient expression co-cultivation process in which transgenic plant cells and recombinant Agrobacterium carrying the viral gene silencing suppressor were grown together in suspension cultures. Through the co-cultivation process, the impacts of gene silencing suppressors on the rAAT production were elucidated, and promising gene silencing suppressors were identified. Furthermore, the combinations of gene silencing suppressors were optimized using design of experiments methodology. The results have shown that in transgenic CMViva cell cultures, the functional rAAT as a percentage of total soluble protein is increased 5.7 fold with the expression of P19, and 17.2 fold with the co-expression of CP, P19 and P24.
Collapse
Affiliation(s)
- Ting-Kuo Huang
- Department of Chemical Engineering and Materials Science, University of California, 1 Shields Avenue, Davis, CA 95616, USA.
| | - Bryce W Falk
- Department of Plant Pathology, University of California, 1 Shields Avenue, Davis, CA 95616, USA.
| | - Abhaya M Dandekar
- Department of Plant Sciences, University of California, 1 Shields Avenue, Davis, CA 95616, USA.
| | - Karen A McDonald
- Department of Chemical Engineering and Materials Science, University of California, 1 Shields Avenue, Davis, CA 95616, USA.
| |
Collapse
|
39
|
Tahmasebi A, Afsharifar A, Heydari A, Mehrabadi M. Evolutionary features of 8K (KDa) silencing suppressor protein of Potato mop-top virus. MOLECULAR BIOLOGY RESEARCH COMMUNICATIONS 2018; 7:43-50. [PMID: 29911122 PMCID: PMC5991528 DOI: 10.22099/mbrc.2018.28458.1304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The cysteine-rich 8K protein of Potato mop-top virus (PMTV) suppresses host RNA silencing. In this study, evolutionary analysis of 8K sequences of PMTV isolates was studied on the basis of nucleotide and amino acid sequences. Twenty-one positively selected sites were identified in 8K coding regions. Recombination events were found in the 8K of PMTV isolates with a rate of 1.8. Totally 30 haplotypes were detected with haplotype diversity ranging from 0.8 to 1.0 and nucleotide diversity from 7.58 to 13.62. The positions 33 and 30 indicated the highly positive and negative selection (with the highest and the lowest dN-dS values), respectively. Tajima's D test suggested that 8K is evolving with a strong positive selection for worldwide isolates. High frequency of segregating sites was identified along 204 positions of 8K. Moreover, in this study, we used Shannon entropy-based approach to evaluate the variability of each site of nucleotide and corresponding amino acid. Based on Shannon entropy method, 139 and 97 nucleotide sites had the highest entropy value, while 47 and 33 amino acid sites showed the most diversity along 8K sequences. Our findings suggest that 8K as an RNA silencing suppressor evolves rapidly. Taken together, its variability might play a big threat to infect other plants or overcome resistant cultivars.
Collapse
Affiliation(s)
- Aminallah Tahmasebi
- Plant Virology Research Center, College of Agriculture, Shiraz University, Shiraz, Iran
| | - Alireza Afsharifar
- Plant Virology Research Center, College of Agriculture, Shiraz University, Shiraz, Iran
| | | | - Mohammad Mehrabadi
- Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
| |
Collapse
|
40
|
Jia G, Li W, Fan M, Yu R, Xu Y, Geng L, Zhang J, Zhu C, Liu H. Pentapeptide-insertion scanning mutational analysis of turkey herpesvirus HVT063 reveals residues important for its RNA silencing suppression activity. Arch Virol 2018; 163:167-174. [PMID: 29052787 DOI: 10.1007/s00705-017-3595-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Accepted: 09/26/2017] [Indexed: 11/30/2022]
Abstract
HVT063, an RNA-binding protein encoded by turkey herpesvirus, has been shown previously to suppress RNA silencing. Here, a scanning library produced by pentapeptide-insertion scanning mutagenesis was used to identify key residues associated with its RNA silencing suppressor (RSS) activity. Forty-two in-frame insertion mutants of HVT063 protein were evaluated for their RSS activity using the dual-luciferase transient expressing assay system. Sixteen mutations resulted in a loss of RSS activity, 20 mutations resulted in decreased RSS activity, and six mutations exhibited high RSS activity similar to wild-type HVT063. Based on a three-dimensional structure prediction, most of the loss-of-function mutations were located around a predominantly α-helical region at the C-terminal end of HVT063. In particular, a conserved domain in this region, named herpes_UL69, showed low tolerance for five-amino-acid insertions. Combined with the results of our previous studies, basic amino acids could play a key role in RSS activity. These results also demonstrate that pentapeptide-insertion scanning mutagenesis combined with dual-luciferase assays is an effective method to functionally characterize RSSs.
Collapse
Affiliation(s)
- Gang Jia
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, Shandong, China
| | - Wenjing Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, Shandong, China
| | - Meina Fan
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, Shandong, China
| | - Ru Yu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, Shandong, China
| | - Yang Xu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, Shandong, China
| | - Liwei Geng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, Shandong, China
| | - Jiedao Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, Shandong, China
| | - Changxiang Zhu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, Shandong, China
| | - Hongmei Liu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, Shandong, China.
| |
Collapse
|
41
|
Melnik S, Neumann AC, Karongo R, Dirndorfer S, Stübler M, Ibl V, Niessner R, Knopp D, Stoger E. Cloning and plant-based production of antibody MC10E7 for a lateral flow immunoassay to detect [4-arginine]microcystin in freshwater. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:27-38. [PMID: 28421663 PMCID: PMC5785354 DOI: 10.1111/pbi.12746] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 03/14/2017] [Accepted: 04/12/2017] [Indexed: 06/07/2023]
Abstract
Antibody MC10E7 is one of a small number of monoclonal antibodies that bind specifically to [Arg4]-microcystins, and it can be used to survey natural water sources and food samples for algal toxin contamination. However, the development of sensitive immunoassays in different test formats, particularly user-friendly tests for on-site analysis, requires a sensitive but also cost-effective antibody. The original version of MC10E7 was derived from a murine hybridoma, but we determined the sequence of the variable regions using the peptide mass-assisted cloning strategy and expressed a scFv (single-chain variable fragment) format of this antibody in yeast and a chimeric full-size version in leaves of Nicotiana tabacum and Nicotiana benthamiana to facilitate inexpensive and scalable production. The specific antigen-binding activity of the purified antibody was verified by surface plasmon resonance spectroscopy and ELISA, confirming the same binding specificity as its hybridoma-derived counterpart. The plant-derived antibody was used to design a lateral flow immunoassay (dipstick) for the sensitive detection of [Arg4]-microcystins at concentrations of 100-300 ng/L in freshwater samples collected at different sites. Plant-based production will likely reduce the cost of the antibody, currently the most expensive component of the dipstick immunoassay, and will allow the development of further antibody-based analytical devices and water purification adsorbents for the efficient removal of toxic contaminants.
Collapse
Affiliation(s)
- Stanislav Melnik
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Anna-Cathrine Neumann
- Institute of Hydrochemistry and Chair for Analytical Chemistry, Technical University Munich, Munich, Germany
| | - Ryan Karongo
- Institute of Hydrochemistry and Chair for Analytical Chemistry, Technical University Munich, Munich, Germany
| | - Sebastian Dirndorfer
- Institute of Hydrochemistry and Chair for Analytical Chemistry, Technical University Munich, Munich, Germany
| | - Martin Stübler
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Verena Ibl
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Reinhard Niessner
- Institute of Hydrochemistry and Chair for Analytical Chemistry, Technical University Munich, Munich, Germany
| | - Dietmar Knopp
- Institute of Hydrochemistry and Chair for Analytical Chemistry, Technical University Munich, Munich, Germany
| | - Eva Stoger
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| |
Collapse
|
42
|
Thukral V, Varshney B, Ramly RB, Ponia SS, Mishra SK, Olsen CM, Banerjea AC, Mukherjee SK, Zaidi R, Rimstad E, Lal SK. s8ORF2 protein of infectious salmon anaemia virus is a RNA-silencing suppressor and interacts with Salmon salar Mov10 (SsMov10) of the host RNAi machinery. Virus Genes 2017; 54:199-214. [PMID: 29218433 PMCID: PMC7089075 DOI: 10.1007/s11262-017-1526-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 11/22/2017] [Indexed: 12/24/2022]
Abstract
The infectious salmon anaemia virus (ISAV) is a piscine virus, a member of Orthomyxoviridae family. It encodes at least 10 proteins from eight negative-strand RNA segments. Since ISAV belongs to the same virus family as Influenza A virus, with similarities in protein functions, they may hence be characterised by analogy. Like NS1 protein of Influenza A virus, s8ORF2 of ISAV is implicated in interferon antagonism and RNA-binding functions. In this study, we investigated the role of s8ORF2 in RNAi suppression in a well-established Agrobacterium transient suppression assay in stably silenced transgenic Nicotiana xanthi. In addition, s8ORF2 was identified as a novel interactor with SsMov10, a key molecule responsible for RISC assembly and maturation in the RNAi pathway. This study thus sheds light on a novel route undertaken by viral proteins in promoting viral growth, using the host RNAi machinery.
Collapse
Affiliation(s)
- Vandana Thukral
- Virology & Plant Molecular Biology Groups, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi, 110067, India
| | - Bhavna Varshney
- Virology & Plant Molecular Biology Groups, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi, 110067, India
| | - Rimatulhana B Ramly
- Norwegian University of Life Science, P.O. Box 8146 Dep., 0033, Oslo, Norway
| | - Sanket S Ponia
- Department of Virology, National Institute of Immunology, New Delhi, 110067, India
| | - Sumona Karjee Mishra
- Virology & Plant Molecular Biology Groups, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi, 110067, India.,Prantae Solutions Pvt. Ltd., KIIT-Campus 11, Bhubaneswar, Odisha, India
| | - Christel M Olsen
- Norwegian University of Life Science, P.O. Box 8146 Dep., 0033, Oslo, Norway
| | - Akhil C Banerjea
- Department of Virology, National Institute of Immunology, New Delhi, 110067, India
| | - Sunil K Mukherjee
- Virology & Plant Molecular Biology Groups, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi, 110067, India
| | - Rana Zaidi
- Department of Biochemistry, Faculty of Science, Jamia Hamdard, New Delhi, 110062, India
| | - Espen Rimstad
- Norwegian University of Life Science, P.O. Box 8146 Dep., 0033, Oslo, Norway
| | - Sunil K Lal
- Virology & Plant Molecular Biology Groups, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi, 110067, India. .,School of Science, Monash University, Sunway Campus, Selangor, 47500, Malaysia.
| |
Collapse
|
43
|
Jassbi AR, Zare S, Asadollahi M, Schuman MC. Ecological Roles and Biological Activities of Specialized Metabolites from the Genus Nicotiana. Chem Rev 2017; 117:12227-12280. [PMID: 28960061 DOI: 10.1021/acs.chemrev.7b00001] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Species of Nicotiana grow naturally in different parts of the world and have long been used both medicinally and recreationally by human societies. More recently in our history, Nicotiana tabacum has attracted interest as one of the most economically important industrial crops. Nicotiana species are frequently investigated for their bioactive natural products, and the ecological role of their specialized metabolites in responses to abiotic stress or biotic stress factors like pathogens and herbivores. The interest of tobacco companies in genetic information as well as the success of a few wild tobacco species as experimental model organisms have resulted in growing knowledge about the molecular biology and ecology of these plants and functional studies of the plant's natural products. Although a large number of reviews and books on biologically active natural products already exists, mostly from N. tabacum, we focus our attention on the ecological roles and biological activity of natural products, versus products from cured and processed material, in this Review. The studied compounds include alkaloids, aromatic compounds, flavonoids, volatiles, sesquiterpenoids, diterpenes alcohols, and sugar esters from trichomes of the plants, and recently characterized acyclic hydroxygeranyllinalool diterpene glycosides (HGL-DTGs). In this Review (1800s-2017), we describe the above-mentioned classes of natural products, emphasizing their biological activities and functions as they have been determined either in bioassay-guided purification approaches or in bioassays with plants in which the expression of specific biosynthetic genes has been genetically manipulated. Additionally, a review on the history, taxonomy, ecology, and medicinal application of different Nicotiana species growing around the globe presented in this Review may be of interest for pharmacognosists, natural products, and ecological chemists.
Collapse
Affiliation(s)
| | | | | | - Meredith C Schuman
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology , Jena 07745, Germany
- German Centre for Integrative Biodiversity Research (iDiv) , Deutscher Platz 5e, Leipzig 04103, Germany
| |
Collapse
|
44
|
Complete genome sequencing of cucumber mosaic virus from black pepper revealed rare deletion in the methyltransferase domain of 1a gene. Virusdisease 2017; 28:309-314. [PMID: 29291218 DOI: 10.1007/s13337-017-0386-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 06/10/2017] [Indexed: 10/19/2022] Open
Abstract
The complete genome of cucumber mosaic virus (CMV) from black pepper was sequenced and compared with CMV isolates from subgroups I and II reported worldwide. Percent identity and phylogenetic analyses clearly indicated that the CMV isolate from black pepper (BP) belongs to subgroup IB. Sequence analyses also showed the presence of a rare deletion of nine nucleotides in the putative methyltransferase domain of 1a gene which was observed only in two more isolates of CMV among one hundred 1a gene sequences of CMV for which sequence information is available in the database. Interestingly this deletion is not present in the black pepper isolate of CMV from China (WN1) and from Indian long pepper that is closely related to black pepper. Percent identity analyses showed that the 3'untranslated region (UTR) of the three RNAs of the BP isolate were conserved with 91% identity whereas the 5'UTR of three RNAs showed 52-80% identity. The level of gene conservation among the subgroups was highest in coat protein and lowest in 2b. The values of nucleotide diversity studies were further consistent with the above data. The ratio of non-synonymous to the synonymous substitution of the five genes of three RNAs was in the order 1a > 2a > 2b > 3a > 3b and less than one for all the genes, indicating purifying selection. These clearly reflect that the protein encoded by RNA1 is highly tolerant to amino acid changes followed by that of RNA2 and, RNA3 is the least tolerant correlating to its functional importance.
Collapse
|
45
|
Tahmasebi AA, Afsharifar A. Cap analog and Potato virus A HC-Pro silencing suppressor improve GFP transient expression using an infectious virus vector in Nicotiana benthamiana. MOLECULAR BIOLOGY RESEARCH COMMUNICATIONS 2017; 6:45-56. [PMID: 28775990 PMCID: PMC5534519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Transient expression of proteins in plants has become a choice to facilitate recombinant protein production with its fast and easy application. On the other hand, host defensive mechanisms have been reported to reduce the efficiency of transient expression in plants. Hence, this study was designed to evaluate the effect of cap analog and Potato virus A helper component proteinase (PVA HC-Pro) on green fluorescent protein (GFP) expression efficiency. N. benthamiana leaves were inoculated with capped or un-capped RNA transcripts of a Turnip crinkle virus (TCV) construct containing a green fluorescent protein reporter gene (TCV-sGFP) in place of its coat protein (CP) ORF. PVA HC-Pro as a viral suppressor of RNA silencing was infiltrated in trans by Agrobacterium tumefaciens, increased the GFP foci diameter to six and even more cells in both capped and un capped treatments. The expression level of GFP in inoculated plants with TCV-sGFP transcript pre-infiltrated with PVA HC-Pro was 12.97-fold higher than the GFP accumulation level in pre-infiltrated leaves with empty plasmid (EP) control. Also, the yield of GFP in inoculated N. benthamiana plants with capped TCV-sGFP transcript pre-infiltrated with EP and PVA HC-Pro was 1.54 and 1.2-fold respectively, greater than the level of GFP expressed without cap analog application at 5 days post inoculation (dpi). In addition, the movement of TCV-sGFP was increased in some cells of inoculated leaves with capped transcripts. Results of this study indicated that PVA HC-Pro and mRNA capping can increase GFP expression and its cell to cell movement in N. benthamiana.
Collapse
Affiliation(s)
- Amin-alah Tahmasebi
- Corresponding Author: Plant Virology Research Center, Shiraz University, Shiraz, Iran, Tel: +98-7132286154, Fax: +98-7132287165 ,E. mail:
| | | |
Collapse
|
46
|
Gleason C, Polzin F, Habash SS, Zhang L, Utermark J, Grundler FMW, Elashry A. Identification of Two Meloidogyne hapla Genes and an Investigation of Their Roles in the Plant-Nematode Interaction. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2017; 30:101-112. [PMID: 28301312 DOI: 10.1094/mpmi-06-16-0107-r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Root-knot nematodes are soil-borne pathogens that invade and establish feeding sites in plant roots. They have an extremely broad host range, including most vascular plants. During infection of a susceptible host, root-knot nematodes secrete molecules called effectors that help them establish an intimate interaction with the plant and, at the same time, allow them to evade or suppress plant immune responses. Despite the fact that Meloidogyne hapla is a significant pest on several food crops, no effectors have been characterized from this root-knot nematode species thus far. Using the published genome and proteome from M. hapla, we have identified and characterized two genes, MhTTL2 and Mh265. MhTTL2 encodes a predicted secreted protein containing a transthyretin-like protein domain. The expression of MhTTL2 was up-regulated during parasitic life stages of the nematode, and in situ hybridization showed that MhTTL2 was expressed in the amphids, suggesting it has a role in the nematode nervous system during parasitism. We also studied the gene Mh265. The Mh265 transcript was localized to the subventral esophageal glands. An upregulation in Mh265 expression coincided with the pre- and early-parasitic life stages of the nematode. When Mh265 was constitutively expressed in plants, it enhanced their susceptibility to nematodes. These transgenic plants were also compromised in flg22-induced callose deposition, suggesting the Mh265 is modulating plant basal immune responses.
Collapse
Affiliation(s)
- Cynthia Gleason
- 1 Georg August University, Albrecht von Haller Institute for Plant Sciences, Dept. of Molecular Biology and Physiology of Plants, Julia-Lermontowa-Weg 3, 37077 Göttingen, Germany
- 2 Georg August University, Göttingen Center for Molecular Biosciences (GZMB), Dept. of Molecular Biology and Physiology of Plants, Julia-Lermontowa-Weg 3, 37077 Göttingen, Germany
- 4 Washington State University, Plant Pathology Department, Pullman, WA 99164 U.S.A
| | - Frederik Polzin
- 1 Georg August University, Albrecht von Haller Institute for Plant Sciences, Dept. of Molecular Biology and Physiology of Plants, Julia-Lermontowa-Weg 3, 37077 Göttingen, Germany
| | - Samer S Habash
- 3 University of Bonn, INRES Molecular Phytomedicine, Karlrobert-Kreiten str. 13, 53115 Bonn, Germany and Agricultural Research Centre, Agricultural Genetic Engineering Research Institute, 9 Gamaa st., Giza 12619, Egypt; and
| | - Lei Zhang
- 4 Washington State University, Plant Pathology Department, Pullman, WA 99164 U.S.A
| | - Jan Utermark
- 1 Georg August University, Albrecht von Haller Institute for Plant Sciences, Dept. of Molecular Biology and Physiology of Plants, Julia-Lermontowa-Weg 3, 37077 Göttingen, Germany
| | - Florian M W Grundler
- 3 University of Bonn, INRES Molecular Phytomedicine, Karlrobert-Kreiten str. 13, 53115 Bonn, Germany and Agricultural Research Centre, Agricultural Genetic Engineering Research Institute, 9 Gamaa st., Giza 12619, Egypt; and
| | - Abdelnaser Elashry
- 3 University of Bonn, INRES Molecular Phytomedicine, Karlrobert-Kreiten str. 13, 53115 Bonn, Germany and Agricultural Research Centre, Agricultural Genetic Engineering Research Institute, 9 Gamaa st., Giza 12619, Egypt; and
| |
Collapse
|
47
|
|
48
|
Kamitani M, Nagano AJ, Honjo MN, Kudoh H. RNA-Seq reveals virus-virus and virus-plant interactions in nature. FEMS Microbiol Ecol 2016; 92:fiw176. [PMID: 27549115 PMCID: PMC5854034 DOI: 10.1093/femsec/fiw176] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 04/10/2016] [Accepted: 08/16/2016] [Indexed: 11/17/2022] Open
Abstract
As research on plant viruses has focused mainly on crop diseases, little is known about these viruses in natural environments. To understand the ecology of viruses in natural systems, comprehensive information on virus-virus and virus-host interactions is required. We applied RNA-Seq to plants from a natural population of Arabidopsis halleri subsp. gemmifera to simultaneously determine the presence/absence of all sequence-reported viruses, identify novel viruses and quantify the host transcriptome. By introducing the criteria of read number and genome coverage, we detected infections by Turnip mosaic virus (TuMV), Cucumber mosaic virus and Brassica yellows virus Active TuMV replication was observed by ultramicroscopy. De novo assembly further identified a novel partitivirus, Arabidopsis halleri partitivirus 1 Interestingly, virus reads reached a maximum level that was equivalent to that of the host's total mRNA, although asymptomatic infection was common. AhgAGO2, a key gene in host defence systems, was upregulated in TuMV-infected plants. Multiple infection was frequent in TuMV-infected leaves, suggesting that TuMV facilitates multiple infection, probably by suppressing host RNA silencing. Revealing hidden plant-virus interactions in nature can enhance our understanding of biological interactions and may have agricultural applications.
Collapse
Affiliation(s)
- Mari Kamitani
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, Shiga 520-2113, Japan
| | - Atsushi J Nagano
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, Shiga 520-2113, Japan Faculty of Agriculture, Ryukoku University, Yokotani 1-5, Seta Oe-cho, Otsu, Shiga 520-2914, Japan JST PRESTO, Japan Science and Technology Agency, Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Mie N Honjo
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, Shiga 520-2113, Japan
| | - Hiroshi Kudoh
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, Shiga 520-2113, Japan
| |
Collapse
|
49
|
Iqbal MS, Hafeez MN, Wattoo JI, Ali A, Sharif MN, Rashid B, Tabassum B, Nasir IA. Prediction of Host-Derived miRNAs with the Potential to Target PVY in Potato Plants. Front Genet 2016; 7:159. [PMID: 27683585 PMCID: PMC5022016 DOI: 10.3389/fgene.2016.00159] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 08/24/2016] [Indexed: 11/25/2022] Open
Abstract
Potato virus Y has emerged as a threatening problem in all potato growing areas around the globe. PVY reduces the yield and quality of potato cultivars. During the last 30 years, significant genetic changes in PVY strains have been observed with an increased incidence associated with crop damage. In the current study, computational approaches were applied to predict Potato derived miRNA targets in the PVY genome. The PVY genome is approximately 9 thousand nucleotides, which transcribes the following 6 genes:CI, NIa, NIb-Pro, HC-Pro, CP, and VPg. A total of 343 mature miRNAs were retrieved from the miRBase database and were examined for their target sequences in PVY genes using the minimum free energy (mfe), minimum folding energy, sequence complementarity and mRNA-miRNA hybridization approaches. The identified potato miRNAs against viral mRNA targets have antiviral activities, leading to translational inhibition by mRNA cleavage and/or mRNA blockage. We found 86 miRNAs targeting the PVY genome at 151 different sites. Moreover, only 36 miRNAs potentially targeted the PVY genome at 101 loci. The CI gene of the PVY genome was targeted by 32 miRNAs followed by the complementarity of 26, 19, 18, 16, and 13 miRNAs. Most importantly, we found 5 miRNAs (miR160a-5p, miR7997b, miR166c-3p, miR399h, and miR5303d) that could target the CI, NIa, NIb-Pro, HC-Pro, CP, and VPg genes of PVY. The predicted miRNAs can be used for the development of PVY-resistant potato crops in the future.
Collapse
Affiliation(s)
- Muhammad S Iqbal
- Centre of Excellence in Molecular Biology, University of the Punjab Lahore, Pakistan
| | - Muhammad N Hafeez
- Centre of Excellence in Molecular Biology, University of the Punjab Lahore, Pakistan
| | - Javed I Wattoo
- Faculty of Life Sciences, University of Central Punjab Lahore, Pakistan
| | - Arfan Ali
- Centre of Excellence in Molecular Biology, University of the PunjabLahore, Pakistan; Institute of Molecular Biology and Biotechnology, The University of LahoreLahore, Pakistan
| | - Muhammad N Sharif
- Centre of Excellence in Molecular Biology, University of the Punjab Lahore, Pakistan
| | - Bushra Rashid
- Centre of Excellence in Molecular Biology, University of the Punjab Lahore, Pakistan
| | - Bushra Tabassum
- Centre of Excellence in Molecular Biology, University of the Punjab Lahore, Pakistan
| | - Idrees A Nasir
- Centre of Excellence in Molecular Biology, University of the Punjab Lahore, Pakistan
| |
Collapse
|
50
|
Untiveros M, Olspert A, Artola K, Firth AE, Kreuze JF, Valkonen JPT. A novel sweet potato potyvirus open reading frame (ORF) is expressed via polymerase slippage and suppresses RNA silencing. MOLECULAR PLANT PATHOLOGY 2016; 17:1111-23. [PMID: 26757490 PMCID: PMC4979677 DOI: 10.1111/mpp.12366] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 12/10/2015] [Accepted: 12/17/2015] [Indexed: 05/20/2023]
Abstract
The single-stranded, positive-sense RNA genome of viruses in the genus Potyvirus encodes a large polyprotein that is cleaved to yield 10 mature proteins. The first three cleavage products are P1, HCpro and P3. An additional short open reading frame (ORF), called pipo, overlaps the P3 region of the polyprotein ORF. Four related potyviruses infecting sweet potato (Ipomoea batatas) are predicted to contain a third ORF, called pispo, which overlaps the 3' third of the P1 region. Recently, pipo has been shown to be expressed via polymerase slippage at a conserved GA6 sequence. Here, we show that pispo is also expressed via polymerase slippage at a GA6 sequence, with higher slippage efficiency (∼5%) than at the pipo site (∼1%). Transient expression of recombinant P1 or the 'transframe' product, P1N-PISPO, in Nicotiana benthamiana suppressed local RNA silencing (RNAi), but only P1N-PISPO inhibited short-distance movement of the silencing signal. These results reveal that polymerase slippage in potyviruses is not limited to pipo expression, but can be co-opted for the evolution and expression of further novel gene products.
Collapse
Affiliation(s)
- Milton Untiveros
- Department of Agricultural Sciences, University of Helsinki, FI-00014, Helsinki, Finland
| | - Allan Olspert
- Department of Pathology, Division of Virology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Katrin Artola
- Department of Agricultural Sciences, University of Helsinki, FI-00014, Helsinki, Finland
| | - Andrew E Firth
- Department of Pathology, Division of Virology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | | | - Jari P T Valkonen
- Department of Agricultural Sciences, University of Helsinki, FI-00014, Helsinki, Finland
| |
Collapse
|