1
|
Oliver JE, Rotenberg D, Agosto-Shaw K, McInnes HA, Lahre KA, Mulot M, Adkins S, Whitfield AE. Multigenic Hairpin Transgenes in Tomato Confer Resistance to Multiple Orthotospoviruses Including Sw-5 Resistance-Breaking Tomato Spotted Wilt Virus. PHYTOPATHOLOGY 2024; 114:1137-1149. [PMID: 37856697 DOI: 10.1094/phyto-07-23-0256-kc] [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: 10/21/2023]
Abstract
Tomato spotted wilt virus (TSWV) and related thrips-borne orthotospoviruses are a threat to food and ornamental crops. Orthotospoviruses have the capacity for rapid genetic change by genome segment reassortment and mutation. Genetic resistance is one of the most effective strategies for managing orthotospoviruses, but there are multiple examples of resistance gene breakdown. Our goal was to develop effective multigenic, broad-spectrum resistance to TSWV and other orthotospoviruses. The most conserved sequences for each open reading frame (ORF) of the TSWV genome were identified, and comparison with other orthotospoviruses revealed sequence conservation within virus clades; some overlapped with domains with well-documented biological functions. We made six hairpin constructs, each of which incorporated sequences matching portions of all five ORFs. Tomato plants expressing the hairpin transgene were challenged with TSWV by thrips and leaf-rub inoculation, and four constructs provided strong protection against TSWV in foliage and fruit. To determine if the hairpin constructs provided protection against other emerging orthotospoviruses, we challenged the plants with tomato chlorotic spot virus and resistance-breaking TSWV and found that the same constructs also provided resistance to these related viruses. Antiviral hairpin constructs are an effective way to protect plants from multiple orthotospoviruses and are an important strategy in the fight against resistance-breaking TSWV and emerging viruses. Targeting of all five viral ORFs is expected to increase the durability of resistance, and combining them with other resistance genes could further extend the utility of this disease control strategy. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
Collapse
Affiliation(s)
- Jonathan E Oliver
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66502
| | - Dorith Rotenberg
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Karolyn Agosto-Shaw
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Holly A McInnes
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Kirsten A Lahre
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Michaël Mulot
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Scott Adkins
- U.S. Department of Agriculture-Agricultural Research Service-USHRL, Fort Pierce, FL 34945
| | - Anna E Whitfield
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| |
Collapse
|
2
|
Piau M, Schmitt-Keichinger C. The Hypersensitive Response to Plant Viruses. Viruses 2023; 15:2000. [PMID: 37896777 PMCID: PMC10612061 DOI: 10.3390/v15102000] [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: 09/11/2023] [Revised: 09/21/2023] [Accepted: 09/23/2023] [Indexed: 10/29/2023] Open
Abstract
Plant proteins with domains rich in leucine repeats play important roles in detecting pathogens and triggering defense reactions, both at the cellular surface for pattern-triggered immunity and in the cell to ensure effector-triggered immunity. As intracellular parasites, viruses are mostly detected intracellularly by proteins with a nucleotide binding site and leucine-rich repeats but receptor-like kinases with leucine-rich repeats, known to localize at the cell surface, have also been involved in response to viruses. In the present review we report on the progress that has been achieved in the last decade on the role of these leucine-rich proteins in antiviral immunity, with a special focus on our current understanding of the hypersensitive response.
Collapse
|
3
|
Tran TTY, Cheng HW, Nguyen VH, Yeh SD. Modification of the Helper Component Proteinase of Papaya Ringspot Virus Vietnam Isolate to Generate Attenuated Mutants for Disease Management by Cross Protection. PHYTOPATHOLOGY 2023; 113:334-344. [PMID: 36129763 DOI: 10.1094/phyto-05-22-0168-r] [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: 06/15/2023]
Abstract
Papaya (Carica papaya) production is seriously limited by papaya ringspot virus (PRSV) worldwide, including in Vietnam. Control of PRSV by cross protection is dependent on the availability of effective mild strains. Here, an infectious cDNA clone was constructed from PRSV isolate TG5 from South Vietnam. Site-directed mutagenesis with point mutations on the essential motifs of the helper component proteinase (HC-Pro) was performed, with or without deleting five amino acids (d5) from its N-terminal region. Mutants TG-d5, TG-d5I7, and TG-d5L206 containing d5, d5 + F7I, and d5 + F206L, respectively, induced mild mottling followed by symptomless recovery on papaya and infected Chenopodium quinoa without lesion formation. Each mutant accumulated in papaya at reduced levels with a zigzag pattern and was stable beyond six monthly passages. The cross-protection effectiveness of the three mutants in papaya against TG5 was investigated, each with 60 plants from three independent trials. The results showed that each mutant provided complete protection (100%) against TG5, 1 month after the challenge inoculation, as verified by the lack of severe symptoms and lack of local lesions in C. quinoa. Further tests revealed that TG-d5I7 also confers high levels of protection against other severe PRSV isolates from South Vietnam, including isolates DN (97%) and ST2 (50%). However, TG-d5I7 is ineffective or less effective (0 to 33%) against seven other severe PRSV strains from different geographic origins, including the isolate HN from North Vietnam. Our results indicate that the protection by the three mutants is highly strain-specific and suitable for the control of PRSV in South Vietnam.
Collapse
Affiliation(s)
- Thi-Thu-Yen Tran
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
- Southern Horticultural Research Institute, Tiengiang, Vietnam
| | - Hao-Wen Cheng
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, R.O.C
| | - Van-Hoa Nguyen
- Southern Horticultural Research Institute, Tiengiang, Vietnam
| | - Shyi-Dong Yeh
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, R.O.C
- Vietnam Overseas Agricultural Science and Technology Innovation Center, National Chung Hsing University, Taichung, Taiwan, R.O.C
| |
Collapse
|
4
|
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]
|
5
|
Mesel F, Zhao M, García B, Simón‐Mateo C, García J. Targeting of genomic and negative-sense strands of viral RNA contributes to antiviral resistance mediated by artificial miRNAs and promotes the emergence of complex viral populations. MOLECULAR PLANT PATHOLOGY 2022; 23:1640-1657. [PMID: 35989243 PMCID: PMC9562735 DOI: 10.1111/mpp.13258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 07/07/2022] [Accepted: 07/16/2022] [Indexed: 05/27/2023]
Abstract
Technology based on artificial small RNAs, including artificial microRNAs (amiRNAs), exploits natural RNA silencing mechanisms to achieve silencing of endogenous genes or pathogens. This technology has been successfully employed to generate resistance against different eukaryotic viruses. However, information about viral RNA molecules effectively targeted by these small RNAs is rather conflicting, and factors contributing to the selection of virus mutants escaping the antiviral activity of virus-specific small RNAs have not been studied in detail. In this work, we transformed Nicotiana benthamiana plants with amiRNA constructs designed against the potyvirus plum pox virus (PPV), a positive-sense RNA virus, and obtained lines highly resistant to PPV infection and others showing partial resistance. These lines have allowed us to verify that amiRNA directed against genomic RNA is more efficient than amiRNA targeting its complementary strand. However, we also provide evidence that the negative-sense RNA strand is cleaved by the amiRNA-guided RNA silencing machinery. Our results show that the selection pressure posed by the amiRNA action on both viral RNA strands causes an evolutionary explosion that results in the emergence of a broad range of virus variants, which can further expand in the presence, and even in the absence, of antiviral challenges.
Collapse
Affiliation(s)
- Frida Mesel
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología (CNB‐CSIC)Campus Universidad Autónoma de MadridMadridSpain
| | - Mingmin Zhao
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología (CNB‐CSIC)Campus Universidad Autónoma de MadridMadridSpain
- College of Horticulture and Plant ProtectionInner Mongolia Agricultural UniversityHohhotChina
| | - Beatriz García
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología (CNB‐CSIC)Campus Universidad Autónoma de MadridMadridSpain
| | - Carmen Simón‐Mateo
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología (CNB‐CSIC)Campus Universidad Autónoma de MadridMadridSpain
| | - Juan Antonio García
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología (CNB‐CSIC)Campus Universidad Autónoma de MadridMadridSpain
| |
Collapse
|
6
|
Tran TTY, Lin TT, Chang CP, Chen CH, Nguyen VH, Yeh SD. Generation of Mild Recombinants of Papaya Ringspot Virus to Minimize the Problem of Strain-Specific Cross-Protection. PHYTOPATHOLOGY 2022; 112:708-719. [PMID: 34384243 DOI: 10.1094/phyto-06-21-0272-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Papaya ringspot virus (PRSV) causes severe damage to papaya (Carica papaya L.) and is the primary limiting factor for papaya production worldwide. A nitrous acid-induced mild strain, PRSV HA 5-1, derived from Hawaii strain HA, has been applied to control PRSV by cross-protection for decades. However, the problem of strain-specific protection hampers its application in Taiwan and other geographic regions outside Hawaii. Here, sequence comparison of the genomic sequence of HA 5-1 with that of HA revealed 69 nucleotide changes, resulting in 31 aa changes, of which 16 aa are structurally different. The multiple mutations of HA 5-1 are considered to result from nitrous acid induction because 86% of nucleotide changes are transition mutations. The stable HA 5-1 was used as a backbone to generate recombinants carrying individual 3' fragments of Vietnam severe strain TG5, including NIa, NIb, and CP3' regions, individually or in combination. Our results indicated that the best heterologous fragment for the recombinant is the region of CP3', with which symptom attenuation of the recombinant is like that of HA 5-1. This mild recombinant HA51/TG5-CP3' retained high levels of protection against the homologous HA in papaya plants and significantly increased the protection against the heterologous TG-5. Similarly, HA 5-1 recombinants carrying individual CP3' fragments from Thailand SMK, Taiwan YK, and Vietnam ST2 severe strains also significantly increase protection against the corresponding heterologous strains in papaya plants. Thus, our recombinant approach for mild strain generation is a fast and effective way to minimize the problem of strain-specific protection.
Collapse
Affiliation(s)
- Thi-Thu-Yen Tran
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
- Southern Horticultural Research Institute, TienGiang, Vietnam
| | - Tzu-Tung Lin
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
| | - Chung-Ping Chang
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
| | - Chun-Hung Chen
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
| | - Van-Hoa Nguyen
- Southern Horticultural Research Institute, TienGiang, Vietnam
| | - Shyi-Dong Yeh
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, R.O.C
- Vietnam Overseas Agricultural Science and Technology Innovation Center, National Chung Hsing University, Taichung, Taiwan, R.O.C
| |
Collapse
|
7
|
Heterologous expression of pepper mild mottle virus coat protein encoding region and its application in immuno-diagnostics. Virusdisease 2020; 31:323-332. [PMID: 32904916 DOI: 10.1007/s13337-020-00597-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 04/29/2020] [Indexed: 10/24/2022] Open
Abstract
Pepper mild mottle virus (PMMoV), a tobamovirus of family Virgaviridae affects the quality and quantity of Capsicum. PMMoV is highly contagious, capable of transmitting through infected seeds and soil. Symptoms are more severe when crop is infected at young stage but remain unnoticed when infection takes place at maturity. Therefore, cost effective diagnostic techniques are required for timely and accurate detection of virus. In present study, coat protein encoding region of PMMoV-HP1 isolate was cloned into expression vector system, pET28a and expressed in BL21, a protease deficient strain of Escherichia coli. The PMMoV-HP1 pathotype was identified as PMMoV-P12 on the basis of coat protein amino acid sequence analysis in our previous study. The overexpression of recombinant coat protein of 26 kDa, corresponding to the expected 6X Histidine tag fused recombinant protein was purified using Ni-NTA columns from insoluble fraction. For antisera production, the purified recombinant protein was dialyzed ~ 24 h to remove urea and then used for raising polyclonal antisera. The specificity and sensitivity of antiserum obtained was demonstrated using different dilutions of antiserum for western blot assay and direct antigen coating enzyme linked immunosorbent assay (DAC-ELISA). In Western blot assay, the test antiserum reacted strongly both with PMMoV-CP in purified protein and native CP in crude sap from PMMoV infected pepper plants, whereas no reaction was observed with healthy plant sap. In DAC-ELISA antiserum dilution up to 1:1000 was capable of detecting the virus in infected sample. The absence of any cross reactivity of test antiserum was confirmed against tobacco mosaic virus, cucumber mosaic virus, tomato spotted wilt virus, pepper veinal mottle virus, potato virus Y and tomato yellow leaf curl virus antigen, known to infect capsicum.
Collapse
|
8
|
Mushtaq M, Mukhtar S, Sakina A, Dar AA, Bhat R, Deshmukh R, Molla K, Kundoo AA, Dar MS. Tweaking genome-editing approaches for virus interference in crop plants. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 147:242-250. [PMID: 31881433 DOI: 10.1016/j.plaphy.2019.12.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 12/18/2019] [Accepted: 12/18/2019] [Indexed: 05/13/2023]
Abstract
Plant viruses infect various economically important crops and cause a serious threat to agriculture. As of now, conventional strategies employed are inadequate to circumvent the proliferation of rapidly evolving plant viruses. In this regard, recent advancement in genome-editing approach looks promising to produce plants resistant to DNA/RNA virus infections. Clustered regularly interspaced palindromic repeats (CRISPR) system has been emerged as a promising genome-editing tool that has received special interest because of its ease, competence and reproducibility. Recent studies have demonstrated that CRISPR/Cas9 system has great potential to confer plant immunity by either directly targeting or cleaving the viral genome in both RNA and DNA viruses. Similarly, the approach can be used for targeting the host susceptibility genes more particularly in case of RNA viruses. In the present review, different approaches and strategies being used to improve plant resistance against devastating viruses are discussed in view of recent advances in CRISPR systems. This review also describes the major pitfalls of CRISPR/Cas9 system that utilizes highly efficient and novel platforms to engineer interference to single and multiple plant RNA viruses.
Collapse
Affiliation(s)
- Muntazir Mushtaq
- School of Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, Chatha, J&K, 180009, India
| | - Shazia Mukhtar
- School of Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, Chatha, J&K, 180009, India
| | - Aafreen Sakina
- Division of Plant Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar, Srinagar, J&K, 190025, India
| | - Aejaz Ahmad Dar
- School of Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, Chatha, J&K, 180009, India.
| | - Rohini Bhat
- ICAR-Directorate of Onion and Garlic Research, Rajagurunagar, Pune, Maharashtra, 410505, India
| | - Rupesh Deshmukh
- National Agri-Food Biotechnology Institute, Sector 81, Sahibzada Ajit Singh Nagar, Punjab, 140308, India
| | - Kutubuddin Molla
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA, 16801, USA
| | - Ajaz Ahmad Kundoo
- Division of Entomology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar, Srinagar, J&K, 190025, India
| | - Mohd Saleem Dar
- Division of Plant Pathology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar, Srinagar, J&K, 190025, India
| |
Collapse
|
9
|
Rubio L, Galipienso L, Ferriol I. Detection of Plant Viruses and Disease Management: Relevance of Genetic Diversity and Evolution. FRONTIERS IN PLANT SCIENCE 2020; 11:1092. [PMID: 32765569 PMCID: PMC7380168 DOI: 10.3389/fpls.2020.01092] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 07/02/2020] [Indexed: 05/04/2023]
Abstract
Plant viruses cause considerable economic losses and are a threat for sustainable agriculture. The frequent emergence of new viral diseases is mainly due to international trade, climate change, and the ability of viruses for rapid evolution. Disease control is based on two strategies: i) immunization (genetic resistance obtained by plant breeding, plant transformation, cross-protection, or others), and ii) prophylaxis to restrain virus dispersion (using quarantine, certification, removal of infected plants, control of natural vectors, or other procedures). Disease management relies strongly on a fast and accurate identification of the causal agent. For known viruses, diagnosis consists in assigning a virus infecting a plant sample to a group of viruses sharing common characteristics, which is usually referred to as species. However, the specificity of diagnosis can also reach higher taxonomic levels, as genus or family, or lower levels, as strain or variant. Diagnostic procedures must be optimized for accuracy by detecting the maximum number of members within the group (sensitivity as the true positive rate) and distinguishing them from outgroup viruses (specificity as the true negative rate). This requires information on the genetic relationships within-group and with members of other groups. The influence of the genetic diversity of virus populations in diagnosis and disease management is well documented, but information on how to integrate the genetic diversity in the detection methods is still scarce. Here we review the techniques used for plant virus diagnosis and disease control, including characteristics such as accuracy, detection level, multiplexing, quantification, portability, and designability. The effect of genetic diversity and evolution of plant viruses in the design and performance of some detection and disease control techniques are also discussed. High-throughput or next-generation sequencing provides broad-spectrum and accurate identification of viruses enabling multiplex detection, quantification, and the discovery of new viruses. Likely, this technique will be the future standard in diagnostics as its cost will be dropping and becoming more affordable.
Collapse
Affiliation(s)
- Luis Rubio
- Centro de Protección Vegetal y Biotecnology, Instituto Valenciano de Investigaciones Agrarias, Moncada, Spain
- *Correspondence: Luis Rubio,
| | - Luis Galipienso
- Centro de Protección Vegetal y Biotecnology, Instituto Valenciano de Investigaciones Agrarias, Moncada, Spain
| | - Inmaculada Ferriol
- Plant Responses to Stress Programme, Centre for Research in Agricultural Genomics (CRAG-CSIC_UAB-UB) Cerdanyola del Vallès, Barcelona, Spain
| |
Collapse
|
10
|
Vadlamudi T, Patil BL, Kaldis A, Sai Gopal DVR, Mishra R, Berbati M, Voloudakis A. DsRNA-mediated protection against two isolates of Papaya ringspot virus through topical application of dsRNA in papaya. J Virol Methods 2019; 275:113750. [PMID: 31647944 DOI: 10.1016/j.jviromet.2019.113750] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 10/01/2019] [Accepted: 10/11/2019] [Indexed: 10/25/2022]
Abstract
Papaya ringspot virus (PRSV) infections in papaya result in heavy yield losses, severely affecting the papaya industry worldwide, and hence warranting for effective control measures. In the past, transgenic papaya cultivars were developed that overexpressed parts of the PRSV genome and exhibited high levels of virus resistance. In the present study, a non-transgenic approach was employed, in which in vitro produced dsRNA molecules derived from a PRSV isolate from South India (PRSV-Tirupati) was tested for dsRNA-mediated protection against two isolates of PRSV through topical application of the dsRNA on papaya. The results showed that the dsRNA molecules from both the coat protein (CP) and helper component-proteinase (HC-Pro) genes of the PRSV-Tirupati isolate conferred 100 % resistance against PRSV-Tirupati infection. Further, the same dsRNA molecules were highly effective against the PRSV-Delhi isolate on the papaya cv. Pusa Nanha, conferring a resistance of 94 % and 81 %, respectively. Systemic papaya leaves of the dsRNA-treated plants were virus-free at 14 days post-inoculation, confirming the robustness of this non-transgenic virus control strategy. In contrast, the control TMV dsRNA did not protect against the PRSV infection. This study on the topical application of dsRNA opened up a new avenue for the control of papaya ringspot disease worldwide.
Collapse
Affiliation(s)
- Tharanath Vadlamudi
- Laboratory of Plant Breeding and Biometry, Faculty of Crop Science, Agricultural University of Athens, Athens, 11855, Greece; Department of Virology, Sri Venkateswara University, Tirupati 517502, Andhra Pradesh, India
| | - Basavaprabhu L Patil
- ICAR-National Research Centre on Plant Biotechnology, IARI, Pusa Campus, New Delhi 110012, India; ICAR-Indian Institute of Horticultural Research, Bengaluru, 560089, India
| | - Athanasios Kaldis
- Laboratory of Plant Breeding and Biometry, Faculty of Crop Science, Agricultural University of Athens, Athens, 11855, Greece
| | | | - Ritesh Mishra
- ICAR-National Research Centre on Plant Biotechnology, IARI, Pusa Campus, New Delhi 110012, India
| | - Margarita Berbati
- Laboratory of Plant Breeding and Biometry, Faculty of Crop Science, Agricultural University of Athens, Athens, 11855, Greece
| | - Andreas Voloudakis
- Laboratory of Plant Breeding and Biometry, Faculty of Crop Science, Agricultural University of Athens, Athens, 11855, Greece.
| |
Collapse
|
11
|
Schiemann J, Dietz-Pfeilstetter A, Hartung F, Kohl C, Romeis J, Sprink T. Risk Assessment and Regulation of Plants Modified by Modern Biotechniques: Current Status and Future Challenges. ANNUAL REVIEW OF PLANT BIOLOGY 2019; 70:699-726. [PMID: 30822113 DOI: 10.1146/annurev-arplant-050718-100025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
This review describes the current status and future challenges of risk assessment and regulation of plants modified by modern biotechniques, namely genetic engineering and genome editing. It provides a general overview of the biosafety and regulation of genetically modified plants and details different regulatory frameworks with a focus on the European situation. The environmental risk and safety assessment of genetically modified plants is explained, and aspects of toxicological assessments are discussed, especially the controversial debate in Europe on the added scientific value of untargeted animal feeding studies. Because RNA interference (RNAi) is increasingly explored for commercial applications, the risk and safety assessment of RNAi-based genetically modified plants is also elucidated. The production, detection, and identification of genome-edited plants are described. Recent applications of modern biotechniques, namely synthetic biology and gene drives, are discussed, and a short outlook on the future follows.
Collapse
Affiliation(s)
- Joachim Schiemann
- Institute for Biosafety in Plant Biotechnology, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, 06484 Quedlinburg, Germany;
| | - Antje Dietz-Pfeilstetter
- Institute for Biosafety in Plant Biotechnology, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, 06484 Quedlinburg, Germany;
| | - Frank Hartung
- Institute for Biosafety in Plant Biotechnology, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, 06484 Quedlinburg, Germany;
| | - Christian Kohl
- Institute for Biosafety in Plant Biotechnology, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, 06484 Quedlinburg, Germany;
| | - Jörg Romeis
- Research Division Agroecology and Environment, Agroscope, 8046 Zurich, Switzerland
| | - Thorben Sprink
- Institute for Biosafety in Plant Biotechnology, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, 06484 Quedlinburg, Germany;
| |
Collapse
|
12
|
Kim HB, Lee Y, Kim CG. Research status of the development of genetically modified papaya (Carica papaya L.) and its biosafety assessment. ACTA ACUST UNITED AC 2018. [DOI: 10.5010/jpb.2018.45.3.171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Ho Bang Kim
- Life Sciences Research Institute, Biomedic Co., Ltd., Bucheon 14548, Korea
| | - Yi Lee
- Department of Industrial Plant Science and Technology, Chungbuk National University, Cheongju 28644, Korea
| | - Chang-Gi Kim
- Bio-Evaluation Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 28116, Korea
| |
Collapse
|
13
|
Harth JE, Ferrari MJ, Helms AM, Tooker JF, Stephenson AG. Zucchini Yellow Mosaic Virus Infection Limits Establishment and Severity of Powdery Mildew in Wild Populations of Cucurbita pepo. FRONTIERS IN PLANT SCIENCE 2018; 9:792. [PMID: 29951077 PMCID: PMC6008421 DOI: 10.3389/fpls.2018.00792] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 05/24/2018] [Indexed: 06/01/2023]
Abstract
Few studies have examined the combined effect of multiple parasites on host fitness. Previous work in the Cucurbita pepo pathosystem indicates that infection with Zucchini yellow mosaic virus (ZYMV) reduces exposure to a second insect-vectored parasite (Erwinia tracheiphila). In this study, we performed two large-scale field experiments employing wild gourds (Cucurbita pepo ssp. texana), including plants with a highly introgressed transgene conferring resistance to ZYMV, to examine the interaction of ZYMV and powdery mildew, a common fungal disease. We found that ZYMV-infected plants are more resistant to powdery mildew (i.e., less likely to experience powdery mildew infection and when infected with powdery mildew, have reduced severity of powdery mildew symptoms). As a consequence, during widespread viral epidemics, proportionally more transgenic plants get powdery mildew than non-transgenic plants, potentially mitigating the benefits of the transgene. A greenhouse study using ZYMV-inoculated and non-inoculated controls (non-transgenic plants) revealed that ZYMV-infected plants were more resistant to powdery mildew than controls, suggesting that the transgene itself had no direct effect on the powdery mildew resistance in our field study. Additionally, we found evidence of elevated levels of salicylic acid, a phytohormone that mediates anti-pathogen defenses, in ZYMV-infected plants, suggesting that viral infection induces a plant immune response (systemic acquired resistance), thereby reducing plant susceptibility to powdery mildew infection.
Collapse
Affiliation(s)
- Jacquelyn E. Harth
- Department of Biology, The Pennsylvania State University, University Park, PA, United States
| | - Matthew J. Ferrari
- Department of Biology, The Pennsylvania State University, University Park, PA, United States
- Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA, United States
| | - Anjel M. Helms
- Department of Entomology, The Pennsylvania State University, University Park, PA, United States
| | - John F. Tooker
- Department of Entomology, The Pennsylvania State University, University Park, PA, United States
| | - Andrew G. Stephenson
- Department of Biology, The Pennsylvania State University, University Park, PA, United States
- Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA, United States
| |
Collapse
|
14
|
Wu Z, Mo C, Zhang S, Li H. Characterization of Papaya ringspot virus isolates infecting transgenic papaya 'Huanong No.1' in South China. Sci Rep 2018; 8:8206. [PMID: 29844514 PMCID: PMC5974079 DOI: 10.1038/s41598-018-26596-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 05/15/2018] [Indexed: 11/09/2022] Open
Abstract
In 2006, the release and cultivation of the genetically modified papaya cultivar 'Huanong No.1' successfully controlled the destructive papaya ringspot disease caused by Papaya ringspot virus (PRSV) in South China. However, some transgenic papaya plants from Guangdong and Hainan are found infected by PRSV. In this study, Field investigation was carried out and susceptible transgenic papaya samples were collected during 2012-2016. Twenty representative isolates were artificially inoculated into Cucurbita pepo and commercialised 'Huanong No.1' papaya, and results indicated that the plants showed obvious disease symptoms. Phylogenetic analysis of CP genes of 120 PRSV-infected isolates showed that PRSV can be divided into three groups. Isolates from Guangdong and Hainan belong to Group III, which is further divided into two subgroups. The isolates collected in this study have greatly diverged from the previously reported dominant strains Ys, Vb and Sm in South China, indicating that they belong to a new lineage. Further analysis showed a highly genetic differentiation between isolates, and 27.1% of the isolates were identified as recombinants on the basis of CP nucleotide sequences. These results indicate that the genetic variation of PRSV and the formation of the new virus lineage may explain the loss of transgenic papaya resistance in South China.
Collapse
Affiliation(s)
- Zilin Wu
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Cuiping Mo
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Shuguang Zhang
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Huaping Li
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China.
| |
Collapse
|
15
|
Dutt M, Zambon FT, Erpen L, Soriano L, Grosser J. Embryo-specific expression of a visual reporter gene as a selection system for citrus transformation. PLoS One 2018; 13:e0190413. [PMID: 29293649 PMCID: PMC5749800 DOI: 10.1371/journal.pone.0190413] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 12/14/2017] [Indexed: 01/18/2023] Open
Abstract
The embryo-specific Dc3 gene promoter driving the VvMybA1 anthocyanin regulatory gene was used to develop a visual selection system for the genetic transformation of citrus. Agrobacterium-mediated transformation of cell suspension cultures resulted in the production of purple transgenic somatic embryos that could be easily separated from the green non-transgenic embryos. The somatic embryos produced phenotypically normal plants devoid of any visual purple coloration. These results were also confirmed using protoplast transformation. There was minimal gene expression in unstressed one-year-old transgenic lines. Cold and drought stress did not have any effect on gene expression, while exogenous ABA and NaCl application resulted in a minor change in gene expression in several transgenic lines. When gas exchange was measured in intact leaves, the transgenic lines were similar to controls under the same environment. Our results provide conclusive evidence for the utilization of a plant-derived, embryo-specific visual reporter system for the genetic transformation of citrus. Such a system could aid in the development of an all-plant, consumer-friendly GM citrus tree.
Collapse
Affiliation(s)
- Manjul Dutt
- Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, United States of America
- * E-mail:
| | - Flavia T. Zambon
- Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, United States of America
| | - Lígia Erpen
- Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, United States of America
- Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, São Paulo, Brazil
| | - Leonardo Soriano
- Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, São Paulo, Brazil
| | - Jude Grosser
- Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, United States of America
| |
Collapse
|
16
|
Fuchs M. Pyramiding resistance-conferring gene sequences in crops. Curr Opin Virol 2017; 26:36-42. [DOI: 10.1016/j.coviro.2017.07.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 07/05/2017] [Accepted: 07/07/2017] [Indexed: 12/26/2022]
|
17
|
Dombrovsky A, Tran-Nguyen LTT, Jones RAC. Cucumber green mottle mosaic virus: Rapidly Increasing Global Distribution, Etiology, Epidemiology, and Management. ANNUAL REVIEW OF PHYTOPATHOLOGY 2017; 55:231-256. [PMID: 28590876 DOI: 10.1146/annurev-phyto-080516-035349] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Cucumber green mottle mosaic virus (CGMMV) was first described in 1935 infecting cucumber, making it one of the first plant viruses to be studied. Its initial distribution occurred out of England to other countries. This was followed by its distribution from England and these other countries to additional countries. This process increased slowly between 1935 and 1985, faster between 1986 and 2006, and rapidly between 2007 and 2016. The discovery that it diminished cucurbit fruit yields and quality, especially of watermelon, prompted a substantial research effort in worst-affected countries. These efforts included obtaining insight into its particle and genome characteristics, evolution, and epidemiology. CGMMV's particle stability, ease of contact transmission, and seed transmissibility, which are typical tobamovirus characteristics, explained its complex disease cycle and its ability to spread locally or over long distances without a vector. Knowledge of its disease etiology and epidemiology enabled development of integrated disease management approaches that rely heavily on diverse phytosanitary measures. Dispersal of seed-borne infection through the international seed trade following cucurbit seed crop production in tropical or subtropical countries explains its recent rapid dispersion worldwide.
Collapse
Affiliation(s)
- Aviv Dombrovsky
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Center, Rishon LeZion 7528809, Israel
| | - Lucy T T Tran-Nguyen
- Plant Industries Division, Northern Territory Department of Primary Industry and Resources, Darwin, Northern Territory 0801, Australia
| | - Roger A C Jones
- Institute of Agriculture, Faculty of Science, University of Western Australia, Crawley, Western Australia 6009, Australia;
- Crop Protection Branch, Department of Agriculture and Food, Western Australia, Department of Agriculture and Food, South Perth, Western Australia 6151, Australia
| |
Collapse
|
18
|
Lindbo JA, Falk BW. The Impact of "Coat Protein-Mediated Virus Resistance" in Applied Plant Pathology and Basic Research. PHYTOPATHOLOGY 2017; 107:624-634. [PMID: 28409526 DOI: 10.1094/phyto-12-16-0442-rvw] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Worldwide, plant viruses cause serious reductions in marketable crop yield and in some cases even plant death. In most cases, the most effective way to control virus diseases is through genetically controlled resistance. However, developing virus-resistant (VR) crops through traditional breeding can take many years, and in some cases is not even possible. Because of this, the demonstration of the first VR transgenic plants in 1985 generated much attention. This seminal report served as an inflection point for research in both basic and applied plant pathology, the results of which have dramatically changed both basic research and in a few cases, commercial crop production. The typical review article on this topic has focused on only basic or only applied research results stemming from this seminal discovery. This can make it difficult for the reader to appreciate the full impact of research on transgenic virus resistance, and the contributions from fundamental research that led to translational applications of this technology. In this review, we take a global view of this topic highlighting the significant changes to both basic and applied plant pathology research and commercial food production that have accumulated in the last 30 plus years. We present these milestones in the historical context of some of the scientific, economic, and environmental drivers for developing specific VR crops. The intent of this review is to provide a single document that adequately records the significant accomplishments of researchers in both basic and applied plant pathology research on this topic and how they relate to each other. We hope this review therefore serves as both an instructional tool for students new to the topic, as well as a source of conversation and discussion for how the technology of engineered virus resistance could be applied in the future.
Collapse
Affiliation(s)
- John A Lindbo
- First author: HM Clause, 28605 County Road 104, Davis, CA 95618; and second author: Department of Plant Pathology, University of California, Davis 95616
| | - Bryce W Falk
- First author: HM Clause, 28605 County Road 104, Davis, CA 95618; and second author: Department of Plant Pathology, University of California, Davis 95616
| |
Collapse
|
19
|
Khalid A, Zhang Q, Yasir M, Li F. Small RNA Based Genetic Engineering for Plant Viral Resistance: Application in Crop Protection. Front Microbiol 2017; 8:43. [PMID: 28167936 PMCID: PMC5253543 DOI: 10.3389/fmicb.2017.00043] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 01/06/2017] [Indexed: 11/13/2022] Open
Abstract
Small RNAs regulate a large set of gene expression in all plants and constitute a natural immunity against viruses. Small RNA based genetic engineering (SRGE) technology had been explored for crop protection against viruses for nearly 30 years. Viral resistance has been developed in diverse crops with SRGE technology and a few viral resistant crops have been approved for commercial release. In this review we summarized the efforts generating viral resistance with SRGE in different crops, analyzed the evolution of the technology, its efficacy in different crops for different viruses and its application status in different crops. The challenge and potential solution for application of SRGE in crop protection are also discussed.
Collapse
Affiliation(s)
| | | | | | - Feng Li
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural UniversityWuhan, China
| |
Collapse
|
20
|
Wagaba H, Beyene G, Aleu J, Odipio J, Okao-Okuja G, Chauhan RD, Munga T, Obiero H, Halsey ME, Ilyas M, Raymond P, Bua A, Taylor NJ, Miano D, Alicai T. Field Level RNAi-Mediated Resistance to Cassava Brown Streak Disease across Multiple Cropping Cycles and Diverse East African Agro-Ecological Locations. FRONTIERS IN PLANT SCIENCE 2017; 7:2060. [PMID: 28127301 PMCID: PMC5226948 DOI: 10.3389/fpls.2016.02060] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 12/23/2016] [Indexed: 05/24/2023]
Abstract
Cassava brown streak disease (CBSD) presents a serious threat to cassava production in East and Central Africa. Currently, no cultivars with high levels of resistance to CBSD are available to farmers. Transgenic RNAi technology was employed to combat CBSD by fusing coat protein (CP) sequences from Ugandan cassava brown streak virus (UCBSV) and Cassava brown streak virus (CBSV) to create an inverted repeat construct (p5001) driven by the constitutive Cassava vein mosaic virus promoter. Twenty-five plant lines of cultivar TME 204 expressing varying levels of small interfering RNAs (siRNAs) were established in confined field trials (CFTs) in Uganda and Kenya. Within an initial CFT at Namulonge, Uganda, non-transgenic TME 204 plants developed foliar and storage root CBSD incidences at 96-100% by 12 months after planting. In contrast, 16 of the 25 p5001 transgenic lines showed no foliar symptoms and had less than 8% of their storage roots symptomatic for CBSD. A direct positive correlation was seen between levels of resistance to CBSD and expression of transgenic CP-derived siRNAs. A subsequent CFT was established at Namulonge using stem cuttings from the initial trial. All transgenic lines established remained asymptomatic for CBSD, while 98% of the non-transgenic TME 204 stake-derived plants developed storage roots symptomatic for CBSD. Similarly, very high levels of resistance to CBSD were demonstrated by TME 204 p5001 RNAi lines grown within a CFT over a full cropping cycle at Mtwapa, coastal Kenya. Sequence analysis of CBSD causal viruses present at the trial sites showed that the transgenic lines were exposed to both CBSV and UCBSV, and that the sequenced isolates shared >90% CP identity with transgenic CP sequences expressed by the p5001 inverted repeat expression cassette. These results demonstrate very high levels of field resistance to CBSD conferred by the p5001 RNAi construct at diverse agro-ecological locations, and across the vegetative cropping cycle.
Collapse
Affiliation(s)
- Henry Wagaba
- National Crops Resources Research InstituteKampala, Uganda
| | - Getu Beyene
- Donald Danforth Plant Science CenterSt. Louis, MO, USA
| | - Jude Aleu
- National Crops Resources Research InstituteKampala, Uganda
| | - John Odipio
- National Crops Resources Research InstituteKampala, Uganda
- Donald Danforth Plant Science CenterSt. Louis, MO, USA
| | | | | | - Theresia Munga
- Kenya Agricultural and Livestock Research OrganizationNairobi, Kenya
| | | | | | | | | | - Anton Bua
- National Crops Resources Research InstituteKampala, Uganda
| | | | - Douglas Miano
- Department of Plant Science and Crop Protection, University of NairobiNairobi, Kenya
| | - Titus Alicai
- National Crops Resources Research InstituteKampala, Uganda
| |
Collapse
|
21
|
Wu M, Lewis J, Moore RC. A wild origin of the loss-of-function lycopene beta cyclase (CYC-b) allele in cultivated, red-fleshed papaya (Carica papaya). AMERICAN JOURNAL OF BOTANY 2017; 104:116-126. [PMID: 28082282 DOI: 10.3732/ajb.1600301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 11/17/2016] [Indexed: 06/06/2023]
Abstract
PREMISE OF THE STUDY The red flesh of some papaya cultivars is caused by a recessive loss-of-function mutation in the coding region of the chromoplast-specific lycopene beta cyclase gene (CYC-b). We performed an evolutionary genetic analysis of the CYC-b locus in wild and cultivated papaya to uncover the origin of this loss-of-function allele in cultivated papaya. METHODS We analyzed the levels and patterns of genetic diversity at the CYC-b locus and six loci in a 100-kb region flanking CYC-b and compared these to genetic diversity levels at neutral autosomal loci. The evolutionary relationships of CYC-b haplotypes were assessed using haplotype network analysis of the CYC-b locus and the 100-kb CYC-b region. KEY RESULTS Genetic diversity at the recessive CYC-b allele (y) was much lower relative to the dominant Y allele found in yellow-fleshed wild and cultivated papaya due to a strong selective sweep. Haplotype network analyses suggest the y allele most likely arose in the wild and was introduced into domesticated varieties after the first papaya domestication event. The shared haplotype structure between some wild, feral, and cultivated haplotypes around the y allele supports subsequent escape of this allele from red cultivars back into wild populations through feral intermediates. CONCLUSIONS Our study supports a protracted domestication process of papaya through the introgression of wild-derived traits and gene flow from cultivars to wild populations. Evidence of gene flow from cultivars to wild populations through feral intermediates has implications for the introduction of transgenic papaya into Central American countries.
Collapse
Affiliation(s)
- Meng Wu
- Miami University, Department of Biology, 212 Pearson Hall, Oxford, Ohio 45056 USA
| | - Jamicia Lewis
- Department of Biological Sciences, Alabama State University, Montgomery, Alabama 36104 USA
| | - Richard C Moore
- Miami University, Department of Biology, 212 Pearson Hall, Oxford, Ohio 45056 USA
| |
Collapse
|
22
|
Perilla-Henao LM, Casteel CL. Vector-Borne Bacterial Plant Pathogens: Interactions with Hemipteran Insects and Plants. FRONTIERS IN PLANT SCIENCE 2016; 7:1163. [PMID: 27555855 PMCID: PMC4977473 DOI: 10.3389/fpls.2016.01163] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 07/20/2016] [Indexed: 05/22/2023]
Abstract
Hemipteran insects are devastating pests of crops due to their wide host range, rapid reproduction, and ability to transmit numerous plant-infecting pathogens as vectors. While the field of plant-virus-vector interactions has flourished in recent years, plant-bacteria-vector interactions remain poorly understood. Leafhoppers and psyllids are by far the most important vectors of bacterial pathogens, yet there are still significant gaps in our understanding of their feeding behavior, salivary secretions, and plant responses as compared to important viral vectors, such as whiteflies and aphids. Even with an incomplete understanding of plant-bacteria-vector interactions, some common themes have emerged: (1) all known vector-borne bacteria share the ability to propagate in the plant and insect host; (2) particular hemipteran families appear to be incapable of transmitting vector-borne bacteria; (3) all known vector-borne bacteria have highly reduced genomes and coding capacity, resulting in host-dependence; and (4) vector-borne bacteria encode proteins that are essential for colonization of specific hosts, though only a few types of proteins have been investigated. Here, we review the current knowledge on important vector-borne bacterial pathogens, including Xylella fastidiosa, Spiroplasma spp., Liberibacter spp., and 'Candidatus Phytoplasma spp.'. We then highlight recent approaches used in the study of vector-borne bacteria. Finally, we discuss the application of this knowledge for control and future directions that will need to be addressed in the field of vector-plant-bacteria interactions.
Collapse
Affiliation(s)
| | - Clare L. Casteel
- Department of Plant Pathology, University of California at Davis, Davis, CAUSA
| |
Collapse
|
23
|
Harth JE, Winsor JA, Weakland DR, Nowak KJ, Ferrari MJ, Stephenson AG. Effects of virus infection on pollen production and pollen performance: Implications for the spread of resistance alleles. AMERICAN JOURNAL OF BOTANY 2016; 103:577-83. [PMID: 26905087 DOI: 10.3732/ajb.1500165] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 07/20/2015] [Indexed: 05/12/2023]
Abstract
PREMISE OF STUDY Studies over the past 25 years have shown that environmental stresses adversely affect male function, including pollen production and pollen performance (germination and pollen tube growth rate). Consequently, genetic variation among plants in resistance to a stress has the potential to impact pollen donation to conspecifics and, if deposited onto a stigma, the ability of the pollen to achieve fertilization. We examined the effects of a nonlethal virus epidemic on pollen production and pollen performance in a population of susceptible and resistant (transgenic) wild squash (Cucurbita pepo subsp. texana). METHODS We grew 135 susceptible and 45 virus-resistant wild squash plants in each of two 0.4-ha fields, initiated a zucchini yellow mosaic virus (ZYMV) epidemic, and recorded staminate and pistillate flower production per plant over the field season and the total number of mature fruit. We also assessed pollen production per flower on ZYMV-infected and non-infected plants and the ability of pollen from flowers on infected and non-infected plants to achieve fertilization under competitive conditions. KEY RESULTS ZYMV infection reduced flower and fruit production per plant and pollen production per flower. Pollen from infected plants was also less likely to sire a seed under competitive conditions. CONCLUSIONS ZYMV infection adversely impacts the amount of pollen that can be donated to conspecifics, and pollen competition within the styles increases the probability that the ovules are fertilized by pollen from plants that are thriving when challenged by a viral disease.
Collapse
Affiliation(s)
- Jacquelyn E Harth
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802 USA
| | - James A Winsor
- Department of Biology, Pennsylvania State University, Altoona, Pennsylvania 16601 USA
| | - Danelle R Weakland
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802 USA
| | - Kayla J Nowak
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802 USA
| | - Matthew J Ferrari
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802 USA
| | - Andrew G Stephenson
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802 USA
| |
Collapse
|
24
|
Genetic Resources of Pumpkins and Squash, Cucurbita spp. GENETICS AND GENOMICS OF CUCURBITACEAE 2016. [DOI: 10.1007/7397_2016_3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
25
|
Simmons HE, Prendeville HR, Dunham JP, Ferrari MJ, Earnest JD, Pilson D, Munkvold GP, Holmes EC, Stephenson AG. Transgenic Virus Resistance in Crop-Wild Cucurbita pepo Does Not Prevent Vertical Transmission of Zucchini yellow mosaic virus. PLANT DISEASE 2015; 99:1616-1621. [PMID: 30695961 DOI: 10.1094/pdis-10-14-1062-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Zucchini yellow mosaic virus (ZYMV) is an economically important pathogen of cucurbits that is transmitted both horizontally and vertically. Although ZYMV is seed-transmitted in Cucurbita pepo, the potential for seed transmission in virus-resistant transgenic cultivars is not known. We crossed and backcrossed a transgenic squash cultivar with wild C. pepo, and determined whether seed-to-seedling transmission of ZYMV was possible in seeds harvested from transgenic backcrossed C. pepo. We then compared these transmission rates to those of non-transgenic (backcrossed and wild) C. pepo. The overall seed-to-seedling transmission rate in ZYMV was similar to those found in previous studies (1.37%), with no significant difference between transgenic backcrossed (2.48%) and non-transgenic (1.03%) backcrossed and wild squash. Fewer transgenic backcrossed plants had symptom development (7%) in comparison with all non-transgenic plants (26%) and may be instrumental in preventing yield reduction due to ZYMV. Our study shows that ZYMV is seed transmitted in transgenic backcrossed squash, which may affect the spread of ZYMV via the movement of ZYMV-infected seeds. Deep genome sequencing of the seed-transmitted viral populations revealed that 23% of the variants found in this study were present in other vertically transmitted ZYMV populations, suggesting that these variants may be necessary for seed transmission or are distributed geographically via seeds.
Collapse
Affiliation(s)
- H E Simmons
- Seed Science Center, Iowa State University, Ames, IA 50011; and Department of Biology, The Pennsylvania State University, University Park, PA 16802
| | - H R Prendeville
- School of Biological Sciences, University of Nebraska, Lincoln, NE 68588; and Department of Biology, University of Virginia, Charlottesville, VA 22904
| | - J P Dunham
- Molecular and Computational Biology, University of Southern California, Los Angeles, CA 90033
| | - M J Ferrari
- Department of Biology, The Pennsylvania State University, University Park, PA 16802
| | - J D Earnest
- Department of Biology, The Pennsylvania State University, University Park, PA 16802
| | - D Pilson
- School of Biological Sciences, University of Nebraska, Lincoln, NE 68588
| | - G P Munkvold
- Seed Science Center, Iowa State University, Ames, IA 50011
| | - E C Holmes
- Department of Biology, The Pennsylvania State University, University Park, PA 16802; and Marie Bashir Institute for Infectious Diseases and Biosecurity, Charles Perkins Centre, School of Biological Sciences and Medical School, The University of Sydney, NSW 2006, Australia
| | - A G Stephenson
- Department of Biology, The Pennsylvania State University, University Park, PA 16802
| |
Collapse
|
26
|
Patil BL, Legg JP, Kanju E, Fauquet CM. Cassava brown streak disease: a threat to food security in Africa. J Gen Virol 2015; 96:956-68. [PMID: 26015320 DOI: 10.1099/vir.0.000014] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cassava brown streak disease (CBSD) has emerged as the most important viral disease of cassava (Manihot esculenta) in Africa and is a major threat to food security. CBSD is caused by two distinct species of ipomoviruses, Cassava brown streak virus and Ugandan cassava brown streak virus, belonging to the family Potyviridae. Previously, CBSD was reported only from the coastal lowlands of East Africa, but recently it has begun to spread as an epidemic throughout the Great Lakes region of East and Central Africa. This new spread represents a major threat to the cassava-growing regions of West Africa. CBSD-resistant cassava cultivars are being developed through breeding, and transgenic RNA interference-derived field resistance to CBSD has also been demonstrated. This review aims to provide a summary of the most important studies on the aetiology, epidemiology and control of CBSD and to highlight key research areas that need prioritization.
Collapse
Affiliation(s)
- Basavaprabhu L Patil
- National Research Centre on Plant Biotechnology, IARI, Pusa Campus, New Delhi 110012, India
| | - James P Legg
- International Institute of Tropical Agriculture, PO Box 34441, Dar-Es-Salaam, Tanzania
| | - Edward Kanju
- International Institute of Tropical Agriculture, PO Box 34441, Dar-Es-Salaam, Tanzania
| | - Claude M Fauquet
- Centro Internacional de Agricultura Tropical, Apartado Aéreo 6713, Cali, Colombia
| |
Collapse
|
27
|
Abstract
Transgenic resistance to plant viruses is an important technology for control of plant virus infection, which has been demonstrated for many model systems, as well as for the most important plant viruses, in terms of the costs of crop losses to disease, and also for many other plant viruses infecting various fruits and vegetables. Different approaches have been used over the last 28 years to confer resistance, to ascertain whether particular genes or RNAs are more efficient at generating resistance, and to take advantage of advances in the biology of RNA interference to generate more efficient and environmentally safer, novel "resistance genes." The approaches used have been based on expression of various viral proteins (mostly capsid protein but also replicase proteins, movement proteins, and to a much lesser extent, other viral proteins), RNAs [sense RNAs (translatable or not), antisense RNAs, satellite RNAs, defective-interfering RNAs, hairpin RNAs, and artificial microRNAs], nonviral genes (nucleases, antiviral inhibitors, and plantibodies), and host-derived resistance genes (dominant resistance genes and recessive resistance genes), and various factors involved in host defense responses. This review examines the above range of approaches used, the viruses that were tested, and the host species that have been examined for resistance, in many cases describing differences in results that were obtained for various systems developed in the last 20 years. We hope this compilation of experiences will aid those who are seeking to use this technology to provide resistance in yet other crops, where nature has not provided such.
Collapse
Affiliation(s)
| | - Peter Palukaitis
- Department of Horticultural Sciences, Seoul Women's University, Seoul, Republic of Korea.
| |
Collapse
|
28
|
Patil BL, Legg JP, Kanju E, Fauquet CM. Cassava brown streak disease: a threat to food security in Africa. J Gen Virol 2015. [DOI: 10.1099/jgv.0.000014] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Affiliation(s)
- Basavaprabhu L. Patil
- National Research Centre on Plant Biotechnology, IARI, Pusa Campus, New Delhi 110012, India
| | - James P. Legg
- International Institute of Tropical Agriculture, PO Box 34441, Dar-Es-Salaam, Tanzania
| | - Edward Kanju
- International Institute of Tropical Agriculture, PO Box 34441, Dar-Es-Salaam, Tanzania
| | - Claude M. Fauquet
- Centro Internacional de Agricultura Tropical, Apartado Aéreo 6713, Cali, Colombia
| |
Collapse
|
29
|
Kung YJ, You BJ, Raja JAJ, Chen KC, Huang CH, Bau HJ, Yang CF, Huang CH, Chang CP, Yeh SD. Nucleotide sequence-homology-independent breakdown of transgenic resistance by more virulent virus strains and a potential solution. Sci Rep 2015; 5:9804. [PMID: 25913508 PMCID: PMC5386206 DOI: 10.1038/srep09804] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 03/05/2015] [Indexed: 11/09/2022] Open
Abstract
Controlling plant viruses by genetic engineering, including the globally important Papaya ringspot virus (PRSV), mainly involves coat protein (CP) gene mediated resistance via post-transcriptional gene silencing (PTGS). However, the breakdown of single- or double-virus resistance in CP-gene-transgenic papaya by more virulent PRSV strains has been noted in repeated field trials. Recombination analysis revealed that the gene silencing suppressor HC-Pro or CP of the virulent PRSV strain 5-19 is responsible for overcoming CP-transgenic resistance in a sequence-homology-independent manner. Transient expression assays using agro-infiltration in Nicotiana benthamiana plants indicated that 5-19 HC-Pro exhibits stronger PTGS suppression than the transgene donor strain. To disarm the suppressor from the virulent strain, transgenic papaya lines were generated carrying untranslatable 5-19 HC-Pro, which conferred complete resistance to 5-19 and other geographic PRSV strains. Our study suggested the potential risk of the emergence of more virulent virus strains, spurred by the deployment of CP-gene-transgenic crops, and provides a strategy to combat such strains.
Collapse
Affiliation(s)
- Yi-Jung Kung
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
- NCHU-UCD Plant and Food Biotechnology Center, National Chung Hsing University, Taiwan, R.O.C
| | - Bang-Jau You
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
- Department of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung, Taiwan, R.O.C
| | - Joseph A. J. Raja
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
- NCHU-UCD Plant and Food Biotechnology Center, National Chung Hsing University, Taiwan, R.O.C
| | - Kuan-Chun Chen
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
| | - Chiung-Huei Huang
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
| | - Huey-Jiunn Bau
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
| | - Ching-Fu Yang
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, R.O.C
| | - Chung-Hao Huang
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
| | - Chung-Ping Chang
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
| | - Shyi-Dong Yeh
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, R.O.C
- NCHU-UCD Plant and Food Biotechnology Center, National Chung Hsing University, Taiwan, R.O.C
- Department of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung, Taiwan, R.O.C
| |
Collapse
|
30
|
Abstract
This chapter represents a travelog of my life and career and the philosophical points I acquired along the way. I was born on a sugar plantation on the island of Hawaii and early on had a stuttering problem. I attended the Kamehameha Schools and received my BS and MS degrees from the University of Hawaii and my Ph.D. from the University of California at Davis. I link my life and career to various principles and events, some of which are: the importance of positioning oneself; going for the big enchilada; music, the international language; the red zone of biotechnology; the human side of biotechnology; the transgenic papaya story; and my leadership time at USDA in Hawaii. The guiding light throughout my career were the words from Drs. Eduardo Trujillo and Robert Shepherd, respectively, "Dennis, don't just be a test tube scientist, do something to help people" and "Now tell me, what have you really accomplished?"
Collapse
Affiliation(s)
- Dennis Gonsalves
- School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section, College of Agriculture and Life Sciences, Cornell University, Geneva, New York 14456;
| |
Collapse
|
31
|
Worrall EA, Wamonje FO, Mukeshimana G, Harvey JJ, Carr JP, Mitter N. Bean Common Mosaic Virus and Bean Common Mosaic Necrosis Virus: Relationships, Biology, and Prospects for Control. Adv Virus Res 2015; 93:1-46. [PMID: 26111585 DOI: 10.1016/bs.aivir.2015.04.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The closely related potyviruses Bean common mosaic virus (BCMV) and Bean common mosaic necrosis virus (BCMNV) are major constraints on common bean (Phaseolus vulgaris) production. Crop losses caused by BCMV and BCMNV impact severely not only on commercial scale cultivation of this high-value crop but also on production by smallholder farmers in the developing world, where bean serves as a key source of dietary protein and mineral nutrition. In many parts of the world, progress has been made in combating BCMV through breeding bean varieties possessing the I gene, a dominant gene conferring resistance to most BCMV strains. However, in Africa, and in particular in Central and East Africa, BCMNV is endemic and this presents a serious problem for deployment of the I gene because this virus triggers systemic necrosis (black root disease) in plants possessing this resistance gene. Information on these two important viruses is scattered throughout the literature from 1917 onward, and although reviews on resistance to BCMV and BCMNV exist, there is currently no comprehensive review on the biology and taxonomy of BCMV and BCMNV. In this chapter, we discuss the current state of our knowledge of these two potyviruses including fundamental aspects of classification and phylogeny, molecular biology, host interactions, transmission through seed and by aphid vectors, geographic distribution, as well as current and future prospects for the control of these important viruses.
Collapse
|
32
|
Nandety RS, Kuo YW, Nouri S, Falk BW. Emerging strategies for RNA interference (RNAi) applications in insects. Bioengineered 2014; 6:8-19. [PMID: 25424593 PMCID: PMC4601220 DOI: 10.4161/21655979.2014.979701] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 09/29/2014] [Accepted: 10/14/2014] [Indexed: 11/19/2022] Open
Abstract
RNA interference (RNAi) in insects is a gene regulatory process that also plays a vital role in the maintenance and in the regulation of host defenses against invading viruses. Small RNAs determine the specificity of the RNAi through precise recognition of their targets. These small RNAs in insects comprise small interfering RNAs (siRNAs), micro RNAs (miRNAs) and Piwi interacting RNAs (piRNAs) of various lengths. In this review, we have explored different forms of the RNAi inducers that are presently in use, and their applications for an effective and efficient fundamental and practical RNAi research with insects. Further, we reviewed trends in next generation sequencing (NGS) technologies and their importance for insect RNAi, including the identification of novel insect targets as well as insect viruses. Here we also describe a rapidly emerging trend of using plant viruses to deliver the RNAi inducer molecules into insects for an efficient RNAi response.
Collapse
Affiliation(s)
| | - Yen-Wen Kuo
- Department of Plant Pathology; University of California; Davis, CA USA
| | - Shahideh Nouri
- Department of Plant Pathology; University of California; Davis, CA USA
| | - Bryce W Falk
- Department of Plant Pathology; University of California; Davis, CA USA
| |
Collapse
|
33
|
Abstract
Grapevine is a high value vegetatively propagated fruit crop that suffers from numerous viruses, including some that seriously affect the profitability of vineyards. Nowadays, 64 viruses belonging to different genera and families have been reported in grapevines and new virus species will likely be described in the future. Three viral diseases namely leafroll, rugose wood, and infectious degeneration are of major economic importance worldwide. The viruses associated with these diseases are transmitted by mealybugs, scale and soft scale insects, or dagger nematodes. Here, we review control measures of the major grapevine viral diseases. More specifically, emphasis is laid on (i) approaches for the production of clean stocks and propagative material through effective sanitation, robust diagnosis, as well as local and regional certification efforts, (ii) the management of vectors of viruses using cultural, biological, and chemical methods, and (iii) the production of resistant grapevines mainly through the application of genetic engineering. The benefits and limitations of the different control measures are discussed with regard to accomplishments and future research directions.
Collapse
Affiliation(s)
- Varvara I Maliogka
- Faculty of agriculture, Forestry and Natural Environment, School of Agriculture, Plant Pathology Lab, Aristotle University of Thessaloniki, Thessaloniki, Greece.
| | | | - Marc Fuchs
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, USA
| | - Nikolaos I Katis
- Faculty of agriculture, Forestry and Natural Environment, School of Agriculture, Plant Pathology Lab, Aristotle University of Thessaloniki, Thessaloniki, Greece
| |
Collapse
|
34
|
Gray S, Cilia M, Ghanim M. Circulative, "nonpropagative" virus transmission: an orchestra of virus-, insect-, and plant-derived instruments. Adv Virus Res 2014; 89:141-99. [PMID: 24751196 DOI: 10.1016/b978-0-12-800172-1.00004-5] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Species of plant viruses within the Luteoviridae, Geminiviridae, and Nanoviridae are transmitted by phloem-feeding insects in a circulative, nonpropagative manner. The precise route of virus movement through the vector can differ across and within virus families, but these viruses all share many biological, biochemical, and ecological features. All share temporal and spatial constraints with respect to transmission efficiency. The viruses also induce physiological changes in their plant hosts resulting in behavioral changes in the insects that optimize the transmission of virus to new hosts. Virus proteins interact with insect, endosymbiont, and plant proteins to orchestrate, directly and indirectly, virus movement in insects and plants to facilitate transmission. Knowledge of these complex interactions allows for the development of new tools to reduce or prevent transmission, to quickly identify important vector populations, and to improve the management of these economically important viruses affecting agricultural and natural plant populations.
Collapse
Affiliation(s)
- Stewart Gray
- Biological Integrated Pest Management Research Unit, USDA, ARS, Ithaca, New York, USA; Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, USA.
| | - Michelle Cilia
- Biological Integrated Pest Management Research Unit, USDA, ARS, Ithaca, New York, USA; Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, USA; Boyce Thompson Institute for Plant Research, Ithaca, New York, USA
| | - Murad Ghanim
- Department of Entomology, Volcani Center, Bet Dagan, Israel
| |
Collapse
|
35
|
Wu J, Yu M, Xu J, Du J, Ji F, Dong F, Li X, Shi J. Impact of transgenic wheat with wheat yellow mosaic virus resistance on microbial community diversity and enzyme activity in rhizosphere soil. PLoS One 2014; 9:e98394. [PMID: 24897124 PMCID: PMC4045665 DOI: 10.1371/journal.pone.0098394] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 05/02/2014] [Indexed: 11/19/2022] Open
Abstract
The transgenic wheat line N12-1 containing the WYMV-Nib8 gene was obtained previously through particle bombardment, and it can effectively control the wheat yellow mosaic virus (WYMV) disease transmitted by Polymyxa graminis at turngreen stage. Due to insertion of an exogenous gene, the transcriptome of wheat may be altered and affect root exudates. Thus, it is important to investigate the potential environmental risk of transgenic wheat before commercial release because of potential undesirable ecological side effects. Our 2-year study at two different experimental locations was performed to analyze the impact of transgenic wheat N12-1 on bacterial and fungal community diversity in rhizosphere soil using polymerase chain reaction-denaturing gel gradient electrophoresis (PCR-DGGE) at four growth stages (seeding stage, turngreen stage, grain-filling stage, and maturing stage). We also explored the activities of urease, sucrase and dehydrogenase in rhizosphere soil. The results showed that there was little difference in bacterial and fungal community diversity in rhizosphere soil between N12-1 and its recipient Y158 by comparing Shannon's, Simpson's diversity index and evenness (except at one or two growth stages). Regarding enzyme activity, only one significant difference was found during the maturing stage at Xinxiang in 2011 for dehydrogenase. Significant growth stage variation was observed during 2 years at two experimental locations for both soil microbial community diversity and enzyme activity. Analysis of bands from the gel for fungal community diversity showed that the majority of fungi were uncultured. The results of this study suggested that virus-resistant transgenic wheat had no adverse impact on microbial community diversity and enzyme activity in rhizosphere soil during 2 continuous years at two different experimental locations. This study provides a theoretical basis for environmental impact monitoring of transgenic wheat when the introduced gene is derived from a virus.
Collapse
Affiliation(s)
- Jirong Wu
- Institute of Food Safety and Detection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Nanjing, China
- Jiangsu Center for GMO evaluation and detection, Nanjing, China
| | - Mingzheng Yu
- Institute of Food Safety and Detection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Nanjing, China
- Jiangsu Center for GMO evaluation and detection, Nanjing, China
| | - Jianhong Xu
- Institute of Food Safety and Detection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Nanjing, China
- Jiangsu Center for GMO evaluation and detection, Nanjing, China
| | - Juan Du
- Institute of Food Safety and Detection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Nanjing, China
- Jiangsu Center for GMO evaluation and detection, Nanjing, China
| | - Fang Ji
- Institute of Food Safety and Detection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Nanjing, China
- Jiangsu Center for GMO evaluation and detection, Nanjing, China
| | - Fei Dong
- Institute of Food Safety and Detection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Nanjing, China
- Jiangsu Center for GMO evaluation and detection, Nanjing, China
| | - Xinhai Li
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jianrong Shi
- Institute of Food Safety and Detection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Nanjing, China
- Jiangsu Center for GMO evaluation and detection, Nanjing, China
| |
Collapse
|
36
|
Azad MAK, Amin L, Sidik NM. Gene technology for papaya ringspot virus disease management. ScientificWorldJournal 2014; 2014:768038. [PMID: 24757435 PMCID: PMC3976845 DOI: 10.1155/2014/768038] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 02/01/2014] [Indexed: 01/19/2023] Open
Abstract
Papaya (Carica papaya) is severely damaged by the papaya ringspot virus (PRSV). This review focuses on the development of PRSV resistant transgenic papaya through gene technology. The genetic diversity of PRSV depends upon geographical distribution and the influence of PRSV disease management on a sequence of PRSV isolates. The concept of pathogen-derived resistance has been employed for the development of transgenic papaya, using a coat protein-mediated, RNA-silencing mechanism and replicase gene-mediated transformation for effective PRSV disease management. The development of PRSV-resistant papaya via post-transcriptional gene silencing is a promising technology for PRSV disease management. PRSV-resistant transgenic papaya is environmentally safe and has no harmful effects on human health. Recent studies have revealed that the success of adoption of transgenic papaya depends upon the application, it being a commercially viable product, bio-safety regulatory issues, trade regulations, and the wider social acceptance of the technology. This review discusses the genome and the genetic diversity of PRSV, host range determinants, molecular diagnosis, disease management strategies, the development of transgenic papaya, environmental issues, issues in the adoption of transgenic papaya, and future directions for research.
Collapse
Affiliation(s)
- Md. Abul Kalam Azad
- Centre for General Studies, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor, Malaysia
- Department of Agricultural Extension, Khamarbari, Farmgate, Dhaka 1215, Bangladesh
| | - Latifah Amin
- Centre for General Studies, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor, Malaysia
| | - Nik Marzuki Sidik
- Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor, Malaysia
| |
Collapse
|
37
|
Non-coding RNAs in crop genetic modification: considerations and predictable environmental risk assessments (ERA). Mol Biotechnol 2014; 55:87-100. [PMID: 23381873 DOI: 10.1007/s12033-013-9648-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Of late non-coding RNAs (ncRNAs)-mediated gene silencing is an influential tool deliberately deployed to negatively regulate the expression of targeted genes. In addition to the widely employed small interfering RNA (siRNA)-mediated gene silencing approach, other variants like artificial miRNA (amiRNA), miRNA mimics, and artificial transacting siRNAs (tasiRNAs) are being explored and successfully deployed in developing non-coding RNA-based genetically modified plants. The ncRNA-based gene manipulations are typified with mobile nature of silencing signals, interference from viral genome-derived suppressor proteins, and an obligation for meticulous computational analysis to prevaricate any inadvertent effects. In a broad sense, risk assessment inquiries for genetically modified plants based on the expression of ncRNAs are competently addressed by the environmental risk assessment (ERA) models, currently in vogue, designed for the first generation transgenic plants which are based on the expression of heterologous proteins. Nevertheless, transgenic plants functioning on the foundation of ncRNAs warrant due attention with respect to their unique attributes like off-target or non-target gene silencing effects, small RNAs (sRNAs) persistence, food and feed safety assessments, problems in detection and tracking of sRNAs in food, impact of ncRNAs in plant protection measures, effect of mutations etc. The role of recent developments in sequencing techniques like next generation sequencing (NGS) and the ERA paradigm of the different countries in vogue are also discussed in the context of ncRNA-based gene manipulations.
Collapse
|
38
|
Abstract
More than 70 well-characterized virus species transmitted by a diversity of vectors may infect cucurbit crops worldwide. Twenty of those cause severe epidemics in major production areas, occasionally leading to complete crop failures. Cucurbit viruses' control is based on three major axes: (i) planting healthy seeds or seedlings in a clean environment, (ii) interfering with vectors activity, and (iii) using resistant cultivars. Seed disinfection and seed or seedling quality controls guarantee growers on the sanitary status of their planting material. Removal of virus or vector sources in the crop environment can significantly delay the onset of viral epidemics. Insecticide or oil application may reduce virus spread in some situations. Diverse cultural practices interfere with or prevent vector reaching the crop. Resistance can be obtained by grafting for soil-borne viruses, by cross-protection, or generally by conventional breeding or genetic engineering. The diversity of the actions that may be taken to limit virus spread in cucurbit crops and their limits will be discussed. The ultimate goal is to provide farmers with technical packages that combine these methods within an integrated disease management program and are adapted to different countries and cropping systems.
Collapse
Affiliation(s)
- Hervé Lecoq
- INRA, UR407, Station de Pathologie Végétale, Montfavet Cedex, France.
| | - Nikolaos Katis
- Faculty of Agriculture, Forestry and Natural Environment, School of Agriculture, Plant Pathology Lab, Aristotle University of Thessaloniki, Thessaloniki, Greece
| |
Collapse
|
39
|
Wei J, Li F, Guo J, Li X, Xu J, Wu G, Zhang D, Yang L. Collaborative ring trial of the papaya endogenous reference gene and its polymerase chain reaction assays for genetically modified organism analysis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:11363-11370. [PMID: 24206192 DOI: 10.1021/jf403338a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The papaya (Carica papaya L.) Chymopapain (CHY) gene has been reported as a suitable endogenous reference gene for genetically modified (GM) papaya detection in previous studies. Herein, we further validated the use of the CHY gene and its qualitative and quantitative polymerase chain reaction (PCR) assays through an interlaboratory collaborative ring trial. A total of 12 laboratories working on detection of genetically modified organisms participated in the ring trial and returned test results. Statistical analysis of the returned results confirmed the species specificity, low heterogeneity, and single-copy number of the CHY gene among different papaya varieties. The limit of detection of the CHY qualitative PCR assay was 0.1%, while the limit of quantification of the quantitative PCR assay was ∼25 copies of haploid papaya genome with acceptable PCR efficiency and linearity. The differences between the tested and true values of papaya content in 10 blind samples ranged from 0.84 to 6.58%. These results indicated that the CHY gene was suitable as an endogenous reference gene for the identification and quantification of GM papaya.
Collapse
Affiliation(s)
- Jiaojun Wei
- National Center for Molecular Characterization of Genetically Modified Organisms, SJTU-Bor Luh Food Safety Center, School of Life Science and Biotechnology, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
40
|
Zhou M, Luo H. MicroRNA-mediated gene regulation: potential applications for plant genetic engineering. PLANT MOLECULAR BIOLOGY 2013; 83:59-75. [PMID: 23771582 DOI: 10.1007/s11103-013-0089-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 06/05/2013] [Indexed: 05/19/2023]
Abstract
Food security is one of the most important issues challenging the world today. Any strategies to solve this problem must include increasing crop yields and quality. MicroRNA-based genetic modification technology (miRNA-based GM tech) can be one of the most promising solutions that contribute to agricultural productivity directly by developing superior crop cultivars with enhanced biotic and abiotic stress tolerance and increased biomass yields. Indirectly, the technology may increase usage of marginal soils and decrease pesticide use, among other benefits. This review highlights the most recent progress of transgenic studies utilizing various miRNAs and their targets for plant trait modifications, and analyzes the potential of miRNA-mediated gene regulation for use in crop improvement. Strategies for manipulating miRNAs and their targets in transgenic plants including constitutive, stress-induced, or tissue-specific expression of miRNAs or their targets, RNA interference, expressing miRNA-resistant target genes, artificial target mimic and artificial miRNAs were discussed. We also discussed potential risks of utilizing miRNA-based GM tech. In general, miRNAs and their targets not only provide an invaluable source of novel transgenes, but also inspire the development of several new GM strategies, allowing advances in breeding novel crop cultivars with agronomically useful characteristics.
Collapse
MESH Headings
- Adaptation, Biological
- Crops, Agricultural/genetics
- Crops, Agricultural/immunology
- Crops, Agricultural/metabolism
- Disease Resistance
- Food Supply
- Food, Genetically Modified
- Gene Expression Regulation, Plant
- Genes, Plant
- Genetic Engineering/methods
- MicroRNAs/genetics
- MicroRNAs/metabolism
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/immunology
- Plants, Genetically Modified/metabolism
- RNA, Plant/genetics
- RNA, Plant/metabolism
- Risk Factors
- Transgenes
Collapse
Affiliation(s)
- Man Zhou
- Department of Genetics and Biochemistry, Clemson University, 110 Biosystems Research Complex, Clemson, SC, 29634, USA
| | | |
Collapse
|
41
|
Abstract
Diverse and rapidly evolving pathogens cause plant diseases and epidemics that threaten crop yield and food security around the world. Research over the last 25 years has led to an increasingly clear conceptual understanding of the molecular components of the plant immune system. Combined with ever-cheaper DNA-sequencing technology and the rich diversity of germ plasm manipulated for over a century by plant breeders, we now have the means to begin development of durable (long-lasting) disease resistance beyond the limits imposed by conventional breeding and in a manner that will replace costly and unsustainable chemical controls.
Collapse
Affiliation(s)
- Jeffery L Dangl
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA.
| | | | | |
Collapse
|
42
|
Biosafety considerations of RNAi-mediated virus resistance in fruit-tree cultivars and in rootstock. Transgenic Res 2013; 22:1073-88. [PMID: 23857556 DOI: 10.1007/s11248-013-9728-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 06/18/2013] [Indexed: 01/06/2023]
Abstract
A major application of RNA interference (RNAi) is envisaged for the production of virus-resistant transgenic plants. For fruit trees, this remains the most, if not the only, viable option for the control of plant viral disease outbreaks in cultivated orchards, due to the difficulties associated with the use of traditional and conventional disease-control measures. The use of RNAi might provide an additional benefit for woody crops if silenced rootstock can efficiently transmit the silencing signal to non-transformed scions, as has already been demonstrated in herbaceous plants. This would provide a great opportunity to produce non-transgenic fruit from transgenic rootstock. In this review, we scrutinise some of the concerns that might arise with the use of RNAi for engineering virus-resistant plants, and we speculate that this virus resistance has fewer biosafety concerns. This is mainly because RNAi-eliciting constructs only express small RNA molecules rather than proteins, and because this technology can be applied using plant rootstock that can confer virus resistance to the scion, leaving the scion untransformed. We discuss the main biosafety concerns related to the release of new types of virus-resistant plants and the risk assessment approaches in the application of existing regulatory systems (in particular, those of the European Union, the USA, and Canada) for the evaluation and approval of RNAi-mediated virus-resistant plants, either as transgenic varieties or as plant virus resistance induced by transgenic rootstock.
Collapse
|
43
|
Jensen PD, Zhang Y, Wiggins BE, Petrick JS, Zhu J, Kerstetter RA, Heck GR, Ivashuta SI. Computational sequence analysis of predicted long dsRNA transcriptomes of major crops reveals sequence complementarity with human genes. GM CROPS & FOOD 2013; 4:90-7. [PMID: 23787988 DOI: 10.4161/gmcr.25285] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Long double-stranded RNAs (long dsRNAs) are precursors for the effector molecules of sequence-specific RNA-based gene silencing in eukaryotes. Plant cells can contain numerous endogenous long dsRNAs. This study demonstrates that such endogenous long dsRNAs in plants have sequence complementarity to human genes. Many of these complementary long dsRNAs have perfect sequence complementarity of at least 21 nucleotides to human genes; enough complementarity to potentially trigger gene silencing in targeted human cells if delivered in functional form. However, the number and diversity of long dsRNA molecules in plant tissue from crops such as lettuce, tomato, corn, soy and rice with complementarity to human genes that have a long history of safe consumption supports a conclusion that long dsRNAs do not present a significant dietary risk.
Collapse
|
44
|
Tatineni S, Sarath G, Seifers D, French R. Immunodetection of Triticum mosaic virus by DAS- and DAC-ELISA using antibodies produced against coat protein expressed in Escherichia coli: potential for high-throughput diagnostic methods. J Virol Methods 2013; 189:196-203. [PMID: 23454646 DOI: 10.1016/j.jviromet.2013.01.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 01/25/2013] [Accepted: 01/30/2013] [Indexed: 11/18/2022]
Abstract
Triticum mosaic virus (TriMV), an economically important virus infecting wheat in the Great Plains region of the USA, is the type species of the Poacevirus genus in the family Potyviridae. Sensitive and high-throughput serology-based detection methods are crucial for the management of TriMV and germplasm screening in wheat breeding programs. In this study, TriMV coat protein (CP) was expressed in Escherichia coli, and polyclonal antibodies were generated against purified soluble native form recombinant CP (rCP) in rabbits. Specificity and sensitivity of resulting antibodies were tested in Western immuno-blot and enzyme-linked immunosorbent assays (ELISA). In direct antigen coating (DAC)-ELISA, antibodies reacted specifically, beyond 1:20,000 dilution with TriMV in crude sap, but not with healthy extracts, and antiserum at a 1:10,000 dilution detected TriMV in crude sap up to 1:4860 dilution. Notably, rabbit anti-TriMV IgG and anti-TriMV IgG-alkaline phosphatase conjugate reacted positively with native virions in crude sap in a double antibody sandwich-ELISA, suggesting that these antibodies can be used as coating antibodies which is crucial for any 'sandwich' type of assays. Finally, the recombinant antibodies reacted positively in ELISA with representative TriMV isolates collected from fields, suggesting that antibodies generated against rCP can be used for sensitive, large-scale, and broad-spectrum detection of TriMV.
Collapse
Affiliation(s)
- Satyanarayana Tatineni
- USDA-ARS and Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68583, USA.
| | | | | | | |
Collapse
|
45
|
Fahim M, Larkin PJ. Designing effective amiRNA and multimeric amiRNA against plant viruses. Methods Mol Biol 2013; 942:357-77. [PMID: 23027061 DOI: 10.1007/978-1-62703-119-6_19] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
RNA-mediated virus resistance is increasingly becoming a method of choice for antiviral defense in plants when effective natural resistance is unavailable. In this chapter we discuss the design principles of artificial micro RNA (amiRNA), in which a natural miRNA precursor gene is modified to target a different species of RNA, in particular viral RNA. In addition, we explore the advantages and effectiveness of multiple amiRNAs within one polycistronic amiRNA precursor against a virus, as illustrated with Wheat streak mosaic virus, WSMV. The judicious selection of amiRNAs, which are sequences of short length as compared to other related methodologies of RNA interference, greatly assists in avoiding unintended off-targets in the host plant. The viral sequences targeted can be genomic or replicative and should be derived from conserved regions of the published WSMV genome. In short, using published folding and miRNA selection rules and algorithms, candidate miRNA sequences are selected from conserved regions between a number of WSMV genomes, and are BLASTed against wheat TIGR ESTs. Five miRNAs are selected that are least likely to interfere with the expression of transcripts from the wheat host. Then, the natural miRNA in each of the five arms of the polycistronic rice miR395 is replaced in silico with the chosen artificial miRNAs. This artificial precursor is transformed into wheat behind a ubiquitin promoter, and its integration into transformed wheat plants is confirmed by PCR and Southern blot analysis. We have demonstrated the effectiveness of this methodology using an amiRNA precursor that we have termed Fanguard. The processing of amiRNAs in transgenic leaves is verified through splinted ligation assay, and the functionality of the transgene in preventing viral replication is verified by virus bioassay. Resistance is confirmed using mechanical virus inoculation over two subsequent generations. This example demonstrates the potential of polycistronic amiRNA to achieve stable immunity to economically important viruses.
Collapse
Affiliation(s)
- Muhammad Fahim
- Lab of Plant Developmental Molecular Genetics, School of Life Science and Biotechnology, Korea University, Seoul, South Korea
| | | |
Collapse
|
46
|
Ogwok E, Odipio J, Halsey M, Gaitán-Solís E, Bua A, Taylor NJ, Fauquet CM, Alicai T. Transgenic RNA interference (RNAi)-derived field resistance to cassava brown streak disease. MOLECULAR PLANT PATHOLOGY 2012; 13:1019-31. [PMID: 22845735 PMCID: PMC6638741 DOI: 10.1111/j.1364-3703.2012.00812.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Cassava brown streak disease (CBSD), caused by the Ipomoviruses Cassava brown streak virus (CBSV) and Ugandan Cassava brown streak virus (UCBSV), is considered to be an imminent threat to food security in tropical Africa. Cassava plants were transgenically modified to generate small interfering RNAs (siRNAs) from truncated full-length (894-bp) and N-terminal (402-bp) portions of the UCBSV coat protein (ΔCP) sequence. Seven siRNA-producing lines from each gene construct were tested under confined field trials at Namulonge, Uganda. All nontransgenic control plants (n = 60) developed CBSD symptoms on aerial tissues by 6 months after planting, whereas plants transgenic for the full-length ΔCP sequence showed a 3-month delay in disease development, with 98% of clonal replicates within line 718-001 remaining symptom free over the 11-month trial. Reverse transcriptase-polymerase chain reaction (RT-PCR) diagnostics indicated the presence of UCBSV within the leaves of 57% of the nontransgenic controls, but in only two of 413 plants tested (0.5%) across the 14 transgenic lines. All transgenic plants showing CBSD were PCR positive for the presence of CBSV, except for line 781-001, in which 93% of plants were confirmed to be free of both pathogens. At harvest, 90% of storage roots from nontransgenic plants were severely affected by CBSD-induced necrosis. However, transgenic lines 718-005 and 718-001 showed significant suppression of disease, with 95% of roots from the latter line remaining free from necrosis and RT-PCR negative for the presence of both viral pathogens. Cross-protection against CBSV by siRNAs generated from the full-length UCBSV ΔCP confirms a previous report in tobacco. The information presented provides proof of principle for the control of CBSD by RNA interference-mediated technology, and progress towards the potential control of this damaging disease.
Collapse
Affiliation(s)
- Emmanuel Ogwok
- National Crops Resources Research Institute, Namulonge, Kampala, Uganda
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Kozub NO, Pilipenko LA, Sozinov IO, Blume YB, Sozinov OO. Genetically modified plants and plant protection problems: Progress and estimation of potential risks. CYTOL GENET+ 2012. [DOI: 10.3103/s0095452712040081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
48
|
Horvath DM, Stall RE, Jones JB, Pauly MH, Vallad GE, Dahlbeck D, Staskawicz BJ, Scott JW. Transgenic resistance confers effective field level control of bacterial spot disease in tomato. PLoS One 2012; 7:e42036. [PMID: 22870280 PMCID: PMC3411616 DOI: 10.1371/journal.pone.0042036] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 06/29/2012] [Indexed: 12/03/2022] Open
Abstract
We investigated whether lines of transgenic tomato (Solanum lycopersicum) expressing the Bs2 resistance gene from pepper, a close relative of tomato, demonstrate improved resistance to bacterial spot disease caused by Xanthomonas species in replicated multi-year field trials under commercial type growing conditions. We report that the presence of the Bs2 gene in the highly susceptible VF 36 background reduced disease to extremely low levels, and VF 36-Bs2 plants displayed the lowest disease severity amongst all tomato varieties tested, including commercial and breeding lines with host resistance. Yields of marketable fruit from transgenic lines were typically 2.5 times that of the non-transformed parent line, but varied between 1.5 and 11.5 fold depending on weather conditions and disease pressure. Trials were conducted without application of any copper-based bactericides, presently in wide use despite negative impacts on the environment. This is the first demonstration of effective field resistance in a transgenic genotype based on a plant R gene and provides an opportunity for control of a devastating pathogen while eliminating ineffective copper pesticides.
Collapse
Affiliation(s)
- Diana M Horvath
- Two Blades Foundation, Evanston, Illinois, United States of America.
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Abstract
RNA interference, or RNAi, is arguably one of the most significant discoveries in biology in the last several decades. First recognized in plants (where it was called post-transcriptional gene silencing, PTGS) RNAi is a gene down-regulation mechanism since demonstrated to exist in all eukaryotes. In RNAi, small RNAs (of about 21-24 nucleotides) function to guide specific effector proteins (members of the Argonaute protein family) to a target nucleotide sequence by complementary base pairing. The effector protein complex then down-regulates the expression of the targeted RNA or DNA. Small RNA-directed gene regulation systems were independently discovered (and named) in plants, fungi, worms, flies, and mammalian cells. Collectively, PTGS, RNA silencing, and co-suppression (in plants); quelling (in fungi and algae); and RNAi (in Caenorhabditis elegans, Drosophila, and mammalian cells) are all examples of small RNA-based gene regulation systems. From the very beginning, plant research has had a major impact on our understanding of RNAi. The purpose of this chapter is to provide an historical perspective and overview on the discovery, characterization, and applications of RNAi in plants.
Collapse
Affiliation(s)
- John A Lindbo
- Campbell's Seeds, Campbells Soup Company, R&D, Davis, CA, USA.
| |
Collapse
|
50
|
Arif M, Azhar U, Arshad M, Zafar Y, Mansoor S, Asad S. Engineering broad-spectrum resistance against RNA viruses in potato. Transgenic Res 2011; 21:303-11. [PMID: 21701953 DOI: 10.1007/s11248-011-9533-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Accepted: 06/15/2011] [Indexed: 10/18/2022]
Abstract
RNA silencing technology has become the tool of choice for inducing resistance against viruses in plants. A significant discovery of this technology is that double-stranded RNA (dsRNA), which is diced into small interfering RNAs (siRNAs), is a potent trigger for RNA silencing. By exploiting this phenomenon in transgenic plants, it is possible to confer high level of virus resistance by specific targeting of cognate viral RNA. In order to maximize the efficiency and versatility of the vector-based siRNA approach, we have constructed a chimeric expression vector containing three partial gene sequences derived from the ORF2 gene of Potato virus X, Helper Component Protease gene of Potato virus Y and Coat protein gene of Potato leaf roll virus. Solanum tuberosum cv. Desiree and Kuroda were transformed with this chimeric gene cassette via Agrobacterium tumefaciens-mediated transformation and transgenic status was confirmed by PCR, Southern and double antibody sandwich ELISA detection. Due to simultaneous RNA silencing, as demonstrated by accumulation of specific siRNAs, the expression of partial triple-gene sequence cassette depicted 20% of the transgenic plants are immune against all three viruses. Thus, expression of a single transgene construct can effectively confer resistance to multiple viruses in transgenic plants.
Collapse
Affiliation(s)
- M Arif
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan
| | | | | | | | | | | |
Collapse
|