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Hou F, Zhang N, Ma L, An L, Zhou X, Zou C, Yang C, Pan G, Lübberstedt T, Shen Y. ZmbZIP54 and ZmFDX5 cooperatively regulate maize seedling tolerance to lead by mediating ZmPRP1 transcription. Int J Biol Macromol 2023; 224:621-633. [PMID: 36273546 DOI: 10.1016/j.ijbiomac.2022.10.151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/14/2022] [Accepted: 10/17/2022] [Indexed: 11/05/2022]
Abstract
Extensive lead (Pb) accumulation in plants exerts toxic effects on plant growth and development and enters the human food chain. Combining linkage mapping, transcriptome analysis, and association studies, we cloned the ZmbZIP54 transcription factor, which confers maize tolerance to Pb. Combined overexpression and knockdown confirmed that ZmbZIP54 mitigates Pb toxicity in maize by alleviating Pb absorption into the roots. Yeast one-hybrid and dual-luciferase assays revealed that ZmbZIP54 binds to the ZmPRP1 promoter and promotes its transcription. Yeast two-hybrid and bimolecular fluorescence complementation assays indicated that ZmFdx5 interacts with ZmbZIP54 in the nucleus. ZmFdx5 acts as a switch that controls the regulation of ZmPRP1 expression by ZmbZIP54 when maize encounters Pb stress. Furthermore, we revealed that variation in the 5'-UTR of ZmbZIP54 affects its expression level under Pb stress and contributes to the difference in Pb tolerance among maize lines. Finally, we proposed a model to summarize the role of ZmbZIP54 in Pb tolerance, which involves the cooperative effect of ZmbZIP54 and ZmFdx5 on the ZmPRP1 transcription in maize response to Pb. This study provides novel insights into the development of Pb-tolerant maize varieties and bioremediation of Pb-contaminated soils.
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Affiliation(s)
- Fengxia Hou
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Na Zhang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Langlang Ma
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Lijun An
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Xun Zhou
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Chaoying Zou
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Cong Yang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Guangtang Pan
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | | | - Yaou Shen
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China.
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Rascón-Cruz Q, González-Barriga CD, Iglesias-Figueroa BF, Trejo-Muñoz JC, Siqueiros-Cendón T, Sinagawa-García SR, Arévalo-Gallegos S, Espinoza-Sánchez EA. Plastid transformation: Advances and challenges for its implementation in agricultural crops. ELECTRON J BIOTECHN 2021. [DOI: 10.1016/j.ejbt.2021.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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3
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Abstract
Expression of transgenes from the plastid genome offers a number of attractions to biotechnologists, with the potential to attain very high protein accumulation levels arguably being the most attractive one. High-level transgene expression is of particular importance in resistance engineering (e.g., for expression of insecticidal proteins) and molecular farming (e.g., for expression of pharmaceutical proteins and industrial enzymes). Over the past decades, the production of many commercially valuable proteins in chloroplast-transgenic (transplastomic) plants has been attempted, including pharmaceutical proteins (e.g., subunit vaccines and protein antibiotics) and industrial enzymes. Although in some cases, spectacularly high foreign protein accumulation levels have been obtained, expression levels were disappointingly poor in other cases. In this review, I summarize our current knowledge about the factors influencing the efficiency of plastid transgene expression, and highlight possible optimization strategies to alleviate problems with poor expression levels. I also discuss available techniques for inducible expression of chloroplast transgenes.
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Yarra R. Plastome engineering in vegetable crops: current status and future prospects. Mol Biol Rep 2020; 47:8061-8074. [PMID: 32880066 DOI: 10.1007/s11033-020-05770-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 08/28/2020] [Indexed: 01/12/2023]
Abstract
Plastome (plastid genome) engineering has grown up and got smarter for the transgene expression. Plastid transformation has profound benefits over nuclear transformation, includes a higher level of transgene expression, integration via homologous recombination, transgene containment, lack of gene silencing, and position effect. Substantial and fruitful progress has been achieved in plastome engineering of vegetable crops through the use of improved regeneration/selection procedures, plastid transformation vectors with efficient promoters, and 3/, 5/regulatory sequences. Plastid transformation technology developed for vegetable crops being used as a platform for the production of industrially important proteins and some of the genes of agronomic importance has been stably integrated and expressed in plastome. Although great progress has been accomplished in the plastid transformation of vegetable crops, still it is restricted to few species because of the unavailability of whole plastome sequencing. In this review, the author focus on the technology, progress, and advancements in plastid transformation of vegetable plants such as lettuce, tomato, potato, cabbage, cauliflower, eggplant, carrot, soybean, and bitter melon are reviewed. The conclusions, future prospects, and expansion of plastid transformation technology to other vegetable crops for genetic improvement and production of edible vaccines are proposed.
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Affiliation(s)
- Rajesh Yarra
- Department of Agronomy, University of Florida, IFAS, Gainesville, FL, 32611, USA.
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Narra M, Kota S, Ellendula R, Kasula K, Kalva BK, Sadanandam A. Efficient chloroplast transformation in Scoparia dulcis L. using pFaadAII vector. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/s40502-018-0392-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Schindel HS, Piatek AA, Stewart CN, Lenaghan SC. The plastid genome as a chassis for synthetic biology-enabled metabolic engineering: players in gene expression. PLANT CELL REPORTS 2018; 37:1419-1429. [PMID: 30039465 DOI: 10.1007/s00299-018-2323-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 07/10/2018] [Indexed: 05/21/2023]
Abstract
Owing to its small size, prokaryotic-like molecular genetics, and potential for very high transgene expression, the plastid genome (plastome) is an attractive plant synthetic biology chassis for metabolic engineering. The plastome exists as a homogenous, compact, multicopy genome within multiple-specialized differentiated plastid compartments. Because of this multiplicity, transgenes can be highly expressed. For coordinated gene expression, it is the prokaryotic molecular genetics that is an especially attractive feature. Multiple genes in a metabolic pathway can be expressed in a series of operons, which are regulated at the transcriptional and translational levels with cross talk from the plant's nuclear genome. Key features of each regulatory level are reviewed, as well as some examples of plastome-enabled metabolic engineering. We also speculate about the transformative future of plastid-based synthetic biology to enable metabolic engineering in plants as well as the problems that must be solved before routine plastome-enabled synthetic circuits can be installed.
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Affiliation(s)
- Heidi S Schindel
- Department of Food Science, University of Tennessee, 2600 River Dr., Knoxville, TN, 37996-4561, USA
| | - Agnieszka A Piatek
- Department of Plant Sciences, University of Tennessee, 2431 Joe Johnson Dr., Knoxville, TN, 37996-4561, USA
| | - C Neal Stewart
- Department of Plant Sciences, University of Tennessee, 2431 Joe Johnson Dr., Knoxville, TN, 37996-4561, USA.
- Center for Agricultural Synthetic Biology, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA.
| | - Scott C Lenaghan
- Department of Food Science, University of Tennessee, 2600 River Dr., Knoxville, TN, 37996-4561, USA.
- Center for Agricultural Synthetic Biology, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA.
- Department of Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee, Knoxville, TN, 37996, USA.
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7
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Tonti-Filippini J, Nevill PG, Dixon K, Small I. What can we do with 1000 plastid genomes? THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:808-818. [PMID: 28112435 DOI: 10.1111/tpj.13491] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/17/2017] [Accepted: 01/17/2017] [Indexed: 05/21/2023]
Abstract
The plastid genome of plants is the smallest and most gene-rich of the three genomes in each cell and the one generally present in the highest copy number. As a result, obtaining plastid DNA sequence is a particularly cost-effective way of discovering genetic information about a plant. Until recently, the sequence information gathered in this way was generally limited to small portions of the genome amplified by polymerase chain reaction, but recent advances in sequencing technology have stimulated a substantial rate of increase in the sequencing of complete plastid genomes. Within the last year, the number of complete plastid genomes accessible in public sequence repositories has exceeded 1000. This sudden flood of data raises numerous challenges in data analysis and interpretation, but also offers the keys to potential insights across large swathes of plant biology. We examine what has been learnt so far, what more could be learnt if we look at the data in the right way, and what we might gain from the tens of thousands more genome sequences that will surely arrive in the next few years. The most exciting new discoveries are likely to be made at the interdisciplinary interfaces between molecular biology and ecology.
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Affiliation(s)
- Julian Tonti-Filippini
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Paul G Nevill
- Department of Environment and Agriculture, ARC Centre for Mine Site Restoration, Curtin University, Kent Street, Bentley, WA, 6102, Australia
| | - Kingsley Dixon
- Department of Environment and Agriculture, ARC Centre for Mine Site Restoration, Curtin University, Kent Street, Bentley, WA, 6102, Australia
| | - Ian Small
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
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Gerasymenko IM, Sheludko YV, Klebanovych AA, Rudas VA, Shakhovsky AM, Klein TM, Kuchuk NV. Comparison of effectiveness of 5'-regulatory sequences in transplastomic tobacco chloroplasts. Transgenic Res 2017; 26:65-75. [PMID: 27565642 DOI: 10.1007/s11248-016-9980-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 08/18/2016] [Indexed: 11/30/2022]
Abstract
The development of tools which ensure the desired level of transgene expression in plastids is a prerequisite for the effective utilization of these plant organelles for the deployment of bioactive proteins. High-level accumulation of target proteins is considered as a positive feature of transplastomic plants, but excessive accumulation of foreign proteins may have deleterious effects on host plants. On the other hand, expression at low levels can result in ineffective phenotypes. We compared the effectiveness of different 5'-regulatory sequences in driving the expression of a reporter gene, β-glucuronidase (uidA), in tobacco chloroplasts. To achieve varying expression levels, we have chosen heterologous 5'-regulatory sequences which either differ significantly from their homologous counterparts or depend on specific nuclear encoded factors. The Medicago truncatula psbA promoter/5'-UTR supported the highest levels of protein accumulation, surpassing the other tested sequences by two to three orders of magnitude. The heterologous regulatory sequence of Phaseolus vulgaris rbcL gene was as efficient in tobacco chloroplasts as the corresponding homologous promoter/5'-UTR. The Arabidopsis thaliana ndhF promoter/5'-UTR supported as high reporter activity levels as the rbcL 5'-sequences, whereas the effectiveness of A. thaliana psbN promoter/5'-UTR was three fold lower. The characterized regulatory sequences can be utilized to establish transplastomic lines with desirable levels of target protein accumulation. The ability to control transgene expression should be useful for achieving appropriate levels of protein accumulation and thereby avoid their negative impacts on host plant physiology.
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Affiliation(s)
- I M Gerasymenko
- Institute of Cell Biology and Genetic Engineering, National Academy of Sciences of Ukraine, Zabolotnoho Str. 148, 03143, Kiev, Ukraine.
| | - Y V Sheludko
- Institute of Cell Biology and Genetic Engineering, National Academy of Sciences of Ukraine, Zabolotnoho Str. 148, 03143, Kiev, Ukraine
| | - A A Klebanovych
- Institute of Cell Biology and Genetic Engineering, National Academy of Sciences of Ukraine, Zabolotnoho Str. 148, 03143, Kiev, Ukraine
| | - V A Rudas
- Institute of Cell Biology and Genetic Engineering, National Academy of Sciences of Ukraine, Zabolotnoho Str. 148, 03143, Kiev, Ukraine
| | - A M Shakhovsky
- Institute of Cell Biology and Genetic Engineering, National Academy of Sciences of Ukraine, Zabolotnoho Str. 148, 03143, Kiev, Ukraine
| | - T M Klein
- DuPont Pioneer AgBiotech, DuPont Experimental Station, Wilmington, DE, USA
| | - N V Kuchuk
- Institute of Cell Biology and Genetic Engineering, National Academy of Sciences of Ukraine, Zabolotnoho Str. 148, 03143, Kiev, Ukraine
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9
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Daniell H, Chan HT, Pasoreck EK. Vaccination via Chloroplast Genetics: Affordable Protein Drugs for the Prevention and Treatment of Inherited or Infectious Human Diseases. Annu Rev Genet 2016; 50:595-618. [PMID: 27893966 PMCID: PMC5496655 DOI: 10.1146/annurev-genet-120215-035349] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Plastid-made biopharmaceuticals treat major metabolic or genetic disorders, including Alzheimer's, diabetes, hypertension, hemophilia, and retinopathy. Booster vaccines made in chloroplasts prevent global infectious diseases, such as tuberculosis, malaria, cholera, and polio, and biological threats, such as anthrax and plague. Recent advances in this field include commercial-scale production of human therapeutic proteins in FDA-approved cGMP facilities, development of tags to deliver protein drugs to targeted human cells or tissues, methods to deliver precise doses, and long-term stability of protein drugs at ambient temperature, maintaining their efficacy. Codon optimization utilizing valuable information from sequenced chloroplast genomes enhanced expression of eukaryotic human or viral genes in chloroplasts and offered unique insights into translation in chloroplasts. Support from major biopharmaceutical companies, development of hydroponic production systems, and evaluation by regulatory agencies, including the CDC, FDA, and USDA, augur well for advancing this novel concept to the clinic and revolutionizing affordable healthcare.
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Affiliation(s)
- Henry Daniell
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104;
| | - Hui-Ting Chan
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104;
| | - Elise K Pasoreck
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104;
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Martin Avila E, Gisby MF, Day A. Seamless editing of the chloroplast genome in plants. BMC PLANT BIOLOGY 2016; 16:168. [PMID: 27474038 PMCID: PMC4966725 DOI: 10.1186/s12870-016-0857-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 07/20/2016] [Indexed: 05/13/2023]
Abstract
BACKGROUND Gene editing technologies enable the precise insertion of favourable mutations and performance enhancing trait genes into chromosomes whilst excluding all excess DNA from modified genomes. The technology gives rise to a new class of biotech crops which is likely to have widespread applications in agriculture. Despite progress in the nucleus, the seamless insertions of point mutations and non-selectable foreign genes into the organelle genomes of crops have not been described. The chloroplast genome is an attractive target to improve photosynthesis and crop performance. Current chloroplast genome engineering technologies for introducing point mutations into native chloroplast genes leave DNA scars, such as the target sites for recombination enzymes. Seamless editing methods to modify chloroplast genes need to address reversal of site-directed point mutations by template mediated repair with the vast excess of wild type chloroplast genomes that are present early in the transformation process. RESULTS Using tobacco, we developed an efficient two-step method to edit a chloroplast gene by replacing the wild type sequence with a transient intermediate. This was resolved to the final edited gene by recombination between imperfect direct repeats. Six out of 11 transplastomic plants isolated contained the desired intermediate and at the second step this was resolved to the edited chloroplast gene in five of six plants tested. Maintenance of a single base deletion mutation in an imperfect direct repeat of the native chloroplast rbcL gene showed the limited influence of biased repair back to the wild type sequence. The deletion caused a frameshift, which replaced the five C-terminal amino acids of the Rubisco large subunit with 16 alternative residues resulting in a ~30-fold reduction in its accumulation. We monitored the process in vivo by engineering an overlapping gusA gene downstream of the edited rbcL gene. Translational coupling between the overlapping rbcL and gusA genes resulted in relatively high GUS accumulation (~0.5 % of leaf protein). CONCLUSIONS Editing chloroplast genomes using transient imperfect direct repeats provides an efficient method for introducing point mutations into chloroplast genes. Moreover, we describe the first synthetic operon allowing expression of a downstream overlapping gene by translational coupling in chloroplasts. Overlapping genes provide a new mechanism for co-ordinating the translation of foreign proteins in chloroplasts.
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Affiliation(s)
- Elena Martin Avila
- Faculty of Life Sciences, The University of Manchester, Manchester, M13 9PT UK
- Present address: Research School of Biology, The Australian National University, Acton, ACT 2601 Australia
| | - Martin F. Gisby
- Faculty of Life Sciences, The University of Manchester, Manchester, M13 9PT UK
| | - Anil Day
- Faculty of Life Sciences, The University of Manchester, Manchester, M13 9PT UK
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Gottschamel J, Lössl A. Chloroplast-Based Expression of Recombinant Proteins by Gateway® Cloning Technology. Methods Mol Biol 2016; 1385:3-27. [PMID: 26614278 DOI: 10.1007/978-1-4939-3289-4_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Plastid transformation for the expression of recombinant proteins and entire enzymatic pathways has become a promising tool for plant biotechnology in the past decade. Several improvements of the technology have turned plant plastids into robust and dependable expression platforms for multiple high value compounds. In this chapter, we describe our current methodology based on Gateway(®) recombinant cloning, which we have adapted for plastid transformation. We describe the steps required for cloning, biolistic transformation, identification, and regeneration of transplastomic plant lines and Western blot analysis.
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Affiliation(s)
- Johanna Gottschamel
- Department of Crop Sciences, University of Natural Resources and Life Sciences, Konrad Lorenz Str. 24, A - 3430, Tulln a. d. Donau, Austria
| | - Andreas Lössl
- Department of Crop Sciences, University of Natural Resources and Life Sciences, Konrad Lorenz Str. 24, A - 3430, Tulln a. d. Donau, Austria.
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12
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Khan MS, Kanwal B, Nazir S. Metabolic engineering of the chloroplast genome reveals that the yeast ArDH gene confers enhanced tolerance to salinity and drought in plants. FRONTIERS IN PLANT SCIENCE 2015; 6:725. [PMID: 26442039 PMCID: PMC4563877 DOI: 10.3389/fpls.2015.00725] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/28/2015] [Indexed: 05/23/2023]
Abstract
Osmoprotectants stabilize proteins and membranes against the denaturing effect of high concentrations of salts and other harmful solutes. In yeast, arabitol dehydrogenase (ArDH) reduces D-ribulose to D-arabitol where D-ribulose is derived by dephosphorylating D-ribulose-5-PO4 in the oxidized pentose pathway. Osmotolerance in plants could be developed through metabolic engineering of chloroplast genome by introducing genes encoding polyols since chloroplasts offer high level transgene expression and containment. Here, we report that ArDH expression in tobacco chloroplasts confers tolerance to NaCl (up to 400 mM). Transgenic plants compared to wild type (WT) survived for only 4-5 weeks on 400 mM NaCl whereas plants remained green and grew normal on concentrations up to 350 mM NaCl. Further, a-week-old seedlings were also challenged with poly ethylene glycol (PEG, up to 6%) in the liquid medium, considering that membranes and proteins are protected under stress conditions due to accumulation of arabitol in chloroplasts. Seedlings were tolerant to 6% PEG, suggesting that ARDH enzyme maintains integrity of membranes in chloroplasts under drought conditions via metabolic engineering. Hence, the gene could be expressed in agronomic plants to withstand abiotic stresses.
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Affiliation(s)
- Muhammad Sarwar Khan
- Center of Agricultural Biochemistry and Biotechnology, University of Agriculture, FaisalabadPakistan
| | - Benish Kanwal
- National Institute for Biotechnology and Genetic Eningeering, FaisalabadPakistan
| | - Shahid Nazir
- Agricultural Biotechnology Research Institute – Ayub Agricultural Research Institute, FaisalabadPakistan
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13
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Larraya LM, Fernández‐San Millán A, Ancín, M, Farran I, Veramendi J. Post‐harvest light treatment increases expression levels of recombinant proteins in transformed plastids of potato tubers. Biotechnol J 2015; 10:1803-13. [DOI: 10.1002/biot.201500028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 05/21/2015] [Accepted: 06/25/2015] [Indexed: 01/22/2023]
Affiliation(s)
- Luis M. Larraya
- Instituto de Agrobiotecnología, Universidad Pública de Navarra‐CSIC, Departamento de Producción Agraria, Pamplona, Spain
| | - Alicia Fernández‐San Millán
- Instituto de Agrobiotecnología, Universidad Pública de Navarra‐CSIC, Departamento de Producción Agraria, Pamplona, Spain
| | - María Ancín,
- Instituto de Agrobiotecnología, Universidad Pública de Navarra‐CSIC, Departamento de Producción Agraria, Pamplona, Spain
| | - Inmaculada Farran
- Instituto de Agrobiotecnología, Universidad Pública de Navarra‐CSIC, Departamento de Producción Agraria, Pamplona, Spain
| | - Jon Veramendi
- Instituto de Agrobiotecnología, Universidad Pública de Navarra‐CSIC, Departamento de Producción Agraria, Pamplona, Spain
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Yarbakht M, Jalali-Javaran M, Nikkhah M, Mohebodini M. Dicistronic expression of human proinsulin-protein A fusion in tobacco chloroplast. Biotechnol Appl Biochem 2015; 62:55-63. [PMID: 24716841 DOI: 10.1002/bab.1230] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 04/01/2014] [Indexed: 11/10/2022]
Abstract
Different expression systems such as bacteria and mammalian cells have been used to produce pharmaceutical proteins. In recent years, the use of plants as bioreactors offers efficient and economical systems in recombinant protein production. Furthermore, because of the large number of plastid copies in plants, chloroplast engineering functions as an effective method to increase recombinant protein expression. Because the commercially available insulin for treatment does not contain C-peptide, which is of great importance for type 1 diabetic patients, the current study introduces the human proinsulin gene fused with protein A into the tobacco chloroplast genome using the biolistic method. To achieve homoplasmy, three rounds of selection and regeneration of transforming cells were performed on the medium that contained spectinomycin antibiotic and hormones. The PCR analysis indicated the presence of the proinsulin gene in transplastomic plants. The reverse-transcription PCR analysis confirmed the expression of the proinsulin-protein A fusion at the transcription level. Immunoblot assays of leaf-derived protein extracts confirmed that the target gene expression is up to 0.2% of the total soluble protein. Our study showed that protein A fusion is not as efficient as other reported fusions. The transplastomic plants were also confirmed for homoplasmy using Southern blot analysis.
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Affiliation(s)
- Melina Yarbakht
- Department of Plant Breeding and Biotechnology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
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15
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Bock R. Engineering plastid genomes: methods, tools, and applications in basic research and biotechnology. ANNUAL REVIEW OF PLANT BIOLOGY 2015; 66:211-41. [PMID: 25494465 DOI: 10.1146/annurev-arplant-050213-040212] [Citation(s) in RCA: 213] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The small bacterial-type genome of the plastid (chloroplast) can be engineered by genetic transformation, generating cells and plants with transgenic plastid genomes, also referred to as transplastomic plants. The transformation process relies on homologous recombination, thereby facilitating the site-specific alteration of endogenous plastid genes as well as the precisely targeted insertion of foreign genes into the plastid DNA. The technology has been used extensively to analyze chloroplast gene functions and study plastid gene expression at all levels in vivo. Over the years, a large toolbox has been assembled that is now nearly comparable to the techniques available for plant nuclear transformation and that has enabled new applications of transplastomic technology in basic and applied research. This review describes the state of the art in engineering the plastid genomes of algae and land plants (Embryophyta). It provides an overview of the existing tools for plastid genome engineering, discusses current technological limitations, and highlights selected applications that demonstrate the immense potential of chloroplast transformation in several key areas of plant biotechnology.
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Affiliation(s)
- Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany;
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16
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Ruhlman TA, Rajasekaran K, Cary JW. Expression of chloroperoxidase from Pseudomonas pyrrocinia in tobacco plastids for fungal resistance. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 228:98-106. [PMID: 25438790 DOI: 10.1016/j.plantsci.2014.02.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 01/31/2014] [Accepted: 02/19/2014] [Indexed: 06/04/2023]
Abstract
The chloroperoxidase (cpo) gene from Pseudomonas pyrrocinia was transformed into the plastid genome (plastome) of Nicotiana tabacum var. Petit Havana and transplastomic lines were compared with a nuclear transformant for the same gene. Southern analysis confirmed integration in the plastome and western blotting confirmed the presence of the chloroperoxidase protein (CPO) in higher abundance in transplastomic plants than in cpo nuclear transformants. Northern analysis of primary plastome transformants for cpo showed 15-fold higher transcript abundance than in the nuclear transformant, yet this extent of enhancement was not observed in western blot, enzyme or bioassay, indicating a bottleneck at the post-transcriptional level. Representative plants from the two transplastomic lines showed resistance to fungal pathogens in vitro (Aspergillus flavus, Fusarium verticillioides, and Verticillium dahliae) and in planta (Alternaria alternata).
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Affiliation(s)
- Tracey A Ruhlman
- USDA, ARS, Southern Regional Research Center, 1100 Robert E. Lee Boulevard, New Orleans, LA 70124-4305, United States.
| | - Kanniah Rajasekaran
- USDA, ARS, Southern Regional Research Center, 1100 Robert E. Lee Boulevard, New Orleans, LA 70124-4305, United States.
| | - Jeffrey W Cary
- USDA, ARS, Southern Regional Research Center, 1100 Robert E. Lee Boulevard, New Orleans, LA 70124-4305, United States.
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Li L, Xue X, Chen Z, Zhang Y, Ma Y, Pan C, Zhu J, Pan X, Zuo S. Isolation and characterization of rl (t), a gene that controls leaf rolling in rice. CHINESE SCIENCE BULLETIN-CHINESE 2014. [DOI: 10.1007/s11434-014-0357-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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Oelze ML, Muthuramalingam M, Vogel MO, Dietz KJ. The link between transcript regulation and de novo protein synthesis in the retrograde high light acclimation response of Arabidopsis thaliana. BMC Genomics 2014; 15:320. [PMID: 24884362 PMCID: PMC4034770 DOI: 10.1186/1471-2164-15-320] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 04/24/2014] [Indexed: 11/10/2022] Open
Abstract
Background Efficient light acclimation of photosynthetic cells is a basic and important property of plants. The process of acclimation depends on transformation of retrograde signals in gene expression, transcript accumulation and de novo protein synthesis. While signalling cues, transcriptomes and some involved players have been characterized, an integrated view is only slowly emerging, and information on the translational level is missing. Transfer of low (8 μmol quanta.m-2.s-1) or normal light (80 μmol quanta.m-2.s-1) acclimated 30 d old Arabidopsis thaliana plants to high light (800 μmol quanta.m-2.s-1) triggers retrograde signals. Using this established approach, we sought to link transcriptome data with de novo synthesized proteins by in vivo labelling with 35S methionine and proteome composition. Results De novo synthesized protein and proteome patterns could reliably be matched with newly annotated master gels. Each molecular level could be quantified for a set of 41 proteins. Among the proteins preferentially synthesized in plants transferred to high light were enzymes including carbonic anhydrase, fructose-1,6-bisphosphate aldolase, O-acetyl serine thiol lyase, and chaperones, while low rates upon transfer to high light were measured for e.g. dehydroascorbate reductase, glyceraldehyde-3-phosphate dehydrogenase and CuZn superoxide dismutase, and opposite responses between 10-fold and 100-fold light increment for e.g. glutamine synthetase and phosphoglycerate kinase. Conclusions The results prove the hypothesis that transcript abundance is poorly linked to de novo protein synthesis due to profound regulation at the level of translation. This vertical systems biology approach enables to quantitatively and kinetically link the molecular levels for scrutinizing signal processing and response generation.
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Affiliation(s)
| | | | | | - Karl-Josef Dietz
- Biochemistry and Physiology of Plants, Faculty of Biology - W5-134, University of Bielefeld, 33501 Bielefeld, Germany.
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Barone P, Zhang XH, Widholm JM. Tryptophan and indole analog mediated plastid transformation. Methods Mol Biol 2014; 1132:187-203. [PMID: 24599854 DOI: 10.1007/978-1-62703-995-6_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A nonantibiotic/herbicide-resistance selection system for plastid transformation is described here in technical detail. This system is based on the feedback-insensitive anthranilate synthase (AS) α-subunit gene of tobacco (ASA2) as a selective marker and tryptophan (Trp) or indole analogs as selection agents. AS catalyzes the first reaction in the Trp biosynthetic pathway, naturally compartmentalized in the plastids, by converting chorismate to anthranilate and is subjected to feedback inhibition by Trp. In addition to Trp, various Trp analogs and indole compounds that can be converted to Trp analogs can also inhibit AS activity and therefore are toxic to cells. When cells are made to express the feedback-insensitive ASA2, they acquire resistance to these analogs and can be selected for during transformation process. We have demonstrated the feasibility of this selection system in tobacco (Nicotiana tabacum L. cv. Petit Havana). ASA2-expressing transplastomic plants were obtained on medium supplemented with either 7-methyl-DL-tryptophan (7-MT) or 4-methylindole (4-MI). These plants show normal phenotype and fertility and transmit the resistance to the selection agents strictly maternally.
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Affiliation(s)
- Pierluigi Barone
- Department of Crop Sciences, University of Illinois, Urbana, IL, USA
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Saxena J, Rawat S. Edible Vaccines. ADVANCES IN BIOTECHNOLOGY 2014. [PMCID: PMC7120417 DOI: 10.1007/978-81-322-1554-7_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
In recent years edible vaccine emerged as a new concept developed by biotechnologists. Edible vaccines are subunit vaccines where the selected genes are introduced into the plants and the transgenic plant is then induced to manufacture the encoded protein. Foods under such application include potato, banana, lettuce, corn, soybean, rice, and legumes. They are easy to administer, easy to store and readily acceptable delivery system for different age group patients yet cost effective. Edible vaccines present exciting possibilities for significantly reducing various diseases such as measles, hepatitis B, cholera, diarrhea, etc., mainly in developing countries. However, various technical and regulatory challenges need to overcome in the path of this emerging vaccine technology to make edible vaccine more efficient and applicable. This chapter attempts to discuss key aspects of edible vaccines like host plants, production, mechanism of action, advantages and limitations, applications, and different regulatory issues concerned to edible vaccines.
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Abstract
Expression of transgenes from the plastid genome offers a number of attractions to biotechnologists, with the potential to attain very high protein accumulation levels arguably being the most attractive one. High-level transgene expression is of particular importance in resistance engineering (e.g., via expression of insecticidal proteins) and molecular farming. Over the past years, the production of many commercially valuable proteins in chloroplast-transgenic (transplastomic) plants has been attempted, including pharmaceutical proteins (such as subunit vaccines and protein antibiotics) and industrial enzymes. Although, in some cases, spectacularly high foreign protein accumulation levels have been obtained, expression levels were disappointingly poor in other cases. In this review, I summarize our current knowledge about the factors influencing the efficiency of plastid transgene expression and highlight possible optimization strategies to alleviate problems with poor expression levels.
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22
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Tangphatsornruang S, Gray JC. Determination of the half-life of chloroplast transcripts in tobacco leaves. Methods Mol Biol 2014; 1132:221-34. [PMID: 24599856 DOI: 10.1007/978-1-62703-995-6_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The amounts of specific transcripts that accumulate in chloroplasts are determined by the rates of synthesis and degradation of the transcripts. The 3' untranslated region of transcripts is a major determinant of the stability of transcripts in chloroplasts. The half-lives of specific transcripts can be determined by northern blot analysis of a time course of transcripts in detached tobacco leaves incubated with actinomycin D, a potent transcription inhibitor. This analysis may be applied to transcripts of endogenous genes or of transgenes introduced into the chloroplast genome in transplastomic plants. Sequence determinants of transcript stability can be identified by analysis of transplastomic plants containing constructs of the green fluorescent protein (gfp) reporter gene fused to the sequences of interest.
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23
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Abstract
Overall translational machinery in plastids is similar to that of E. coli. Initiation is the crucial step for translation and this step in plastids is somewhat different from that of E. coli. Unlike the Shine-Dalgarno sequence in E. coli, cis-elements for translation initiation are not well conserved in plastid mRNAs. Specific trans-acting factors are generally required for translation initiation and its regulation in plastids. During translation elongation, ribosomes pause sometimes on photosynthesis-related mRNAs due probably to proper insertion of nascent polypeptides into membrane complexes. Codon usage of plastid mRNAs is different from that of E. coli and mammalian cells. Plastid mRNAs do not have the so-called rare codons. Translation efficiencies of several synonymous codons are not always correlated with codon usage in plastid mRNAs.
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Gottschamel J, Waheed MT, Clarke JL, Lössl AG. A novel chloroplast transformation vector compatible with the Gateway(®) recombination cloning technology. Transgenic Res 2013; 22:1273-8. [PMID: 23813058 DOI: 10.1007/s11248-013-9726-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 06/13/2013] [Indexed: 12/24/2022]
Abstract
To analyze the suitability of Gateway(®) vectors for transformation of chloroplasts, we converted a standard plastid transformation vector into a Gateway(®) destination vector containing the necessary recombination sites attR1 and attR2. Insertion of the green fluorescent protein (GFP) coding sequence with associated T7g10 ribosome binding site into this destination vector created the expression vector for transformation of tobacco chloroplasts with the biolistic method. Correct integration of the transgene into the plastid genome was verified by PCR and the homoplasmic nature of the transformed plants was confirmed by Southern Blot analysis. Expression of the GFP reporter protein was monitored by confocal laser scanning microscopy (CLSM) and quantification by western blot analysis showed a GFP accumulation level of 3% total soluble protein (TSP). The presented results clearly demonstrate that the Gateway(®) recombination sites are compatible with all steps of plastid transformation, from generation of transplastomic plants to expression of GFP. This is the first report of a plastid transformation vector made by the Gateway(®) recombinant cloning technology, which proves the suitability of this system for use in chloroplasts.
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Affiliation(s)
- Johanna Gottschamel
- Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna, Konrad Lorenz Street 24, 3430, Tulln, Austria
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25
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Somleva MN, Peoples OP, Snell KD. PHA bioplastics, biochemicals, and energy from crops. PLANT BIOTECHNOLOGY JOURNAL 2013; 11:233-52. [PMID: 23294864 DOI: 10.1111/pbi.12039] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2012] [Revised: 11/21/2012] [Accepted: 11/28/2012] [Indexed: 05/09/2023]
Abstract
Large scale production of polyhydroxyalkanoates (PHAs) in plants can provide a sustainable supply of bioplastics, biochemicals, and energy from sunlight and atmospheric CO(2). PHAs are a class of polymers with various chain lengths that are naturally produced by some microorganisms as storage materials. The properties of these polyesters make them functionally equivalent to many of the petroleum-based plastics that are currently in the market place. However, unlike most petroleum-derived plastics, PHAs can be produced from renewable feedstocks and easily degrade in most biologically active environments. This review highlights research efforts over the last 20 years to engineer the production of PHAs in plants with a focus on polyhydroxybutryrate (PHB) production in bioenergy crops with C(4) photosynthesis. PHB has the potential to be a high volume commercial product with uses not only in the plastics and materials markets, but also in renewable chemicals and feed. The major challenges of improving product yield and plant fitness in high biomass yielding C(4) crops are discussed in detail.
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26
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Caroca R, Howell KA, Hasse C, Ruf S, Bock R. Design of chimeric expression elements that confer high-level gene activity in chromoplasts. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 73:368-79. [PMID: 23004223 DOI: 10.1111/tpj.12031] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 09/14/2012] [Accepted: 09/17/2012] [Indexed: 05/05/2023]
Abstract
Non-green plastids, such as chromoplasts, generally have much lower activity of gene expression than chloroplasts in photosynthetically active tissues. Suppression of plastid genes in non-green tissues occurs through a complex interplay of transcriptional and translational control, with the contribution of regulation of transcript abundance versus translational activity being highly variable between genes. Here, we have investigated whether the low expression of the plastid genome in chromoplasts results from inherent limitations in gene expression capacity, or can be overcome by designing appropriate combinations of promoters and translation initiation signals in the 5' untranslated region (5'-UTR). We constructed chimeric expression elements that combine promoters and 5'-UTRs from plastid genes, which are suppressed during chloroplast-to-chromoplast conversion in Solanum lycopersicum (tomato) fruit ripening, either just at the translational level or just at the level of mRNA accumulation. These chimeric expression elements were introduced into the tomato plastid genome by stable chloroplast transformation. We report the identification of promoter-UTR combinations that confer high-level gene expression in chromoplasts of ripe tomato fruits, resulting in the accumulation of reporter protein GFP to up to 1% of total cellular protein. Our work demonstrates that non-green plastids are capable of expressing genes to high levels. Moreover, the chimeric cis-elements for chromoplasts developed here are widely applicable in basic and applied research using transplastomic methods.
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Affiliation(s)
- Rodrigo Caroca
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany
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27
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Hanson MR, Gray BN, Ahner BA. Chloroplast transformation for engineering of photosynthesis. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:731-42. [PMID: 23162121 DOI: 10.1093/jxb/ers325] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Many efforts are underway to engineer improvements in photosynthesis to meet the challenges of increasing demands for food and fuel in rapidly changing environmental conditions. Various transgenes have been introduced into either the nuclear or plastid genomes in attempts to increase photosynthetic efficiency. We examine the current knowledge of the critical features that affect levels of expression of plastid transgenes and protein accumulation in transplastomic plants, such as promoters, 5' and 3' untranslated regions, RNA-processing sites, translation signals and amino acid sequences that affect protein turnover. We review the prior attempts to manipulate the properties of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) through plastid transformation. We illustrate how plastid operons could be created for expression of the multiple genes needed to introduce new pathways or enzymes to enhance photosynthetic rates or reduce photorespiration. We describe here the past accomplishments and future prospects for manipulating plant enzymes and pathways to enhance carbon assimilation through plastid transformation.
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Affiliation(s)
- Maureen R Hanson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
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28
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Venkatesh J, Park SW. Plastid genetic engineering in Solanaceae. PROTOPLASMA 2012; 249:981-99. [PMID: 22395455 PMCID: PMC3459085 DOI: 10.1007/s00709-012-0391-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 02/21/2012] [Indexed: 05/23/2023]
Abstract
Plastid genetic engineering has come of age, becoming today an attractive alternative approach for the expression of foreign genes, as it offers several advantages over nuclear transformants. Significant progress has been made in plastid genetic engineering in tobacco and other Solanaceae plants, through the use of improved regeneration procedures and transformation vectors with efficient promoters and untranslated regions. Many genes encoding for industrially important proteins and vaccines, as well as genes conferring important agronomic traits, have been stably integrated and expressed in the plastid genome. Despite these advances, it remains a challenge to achieve marked levels of plastid transgene expression in non-green tissues. In this review, we summarize the basic requirements of plastid genetic engineering and discuss the current status, limitations, and the potential of plastid transformation for expanding future studies relating to Solanaceae plants.
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Affiliation(s)
- Jelli Venkatesh
- Department of Molecular Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 143-701 Republic of Korea
| | - Se Won Park
- Department of Molecular Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 143-701 Republic of Korea
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29
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Zhang J, Ruf S, Hasse C, Childs L, Scharff LB, Bock R. Identification of cis-elements conferring high levels of gene expression in non-green plastids. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 72:115-28. [PMID: 22639905 DOI: 10.1111/j.1365-313x.2012.05065.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Although our knowledge about the mechanisms of gene expression in chloroplasts has increased substantially over the past decades, next to nothing is known about the signals and factors that govern expression of the plastid genome in non-green tissues. Here we report the development of a quantitative method suitable for determining the activity of cis-acting elements for gene expression in non-green plastids. The in vivo assay is based on stable transformation of the plastid genome and the discovery that root length upon seedling growth in the presence of the plastid translational inhibitor kanamycin is directly proportional to the expression strength of the resistance gene nptII in transgenic tobacco plastids. By testing various combinations of promoters and translation initiation signals, we have used this experimental system to identify cis-elements that are highly active in non-green plastids. Surprisingly, heterologous expression elements from maize plastids were significantly more efficient in conferring high expression levels in root plastids than homologous expression elements from tobacco. Our work has established a quantitative method for characterization of gene expression in non-green plastid types, and has led to identification of cis-elements for efficient plastid transgene expression in non-green tissues, which are valuable tools for future transplastomic studies in basic and applied research.
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Affiliation(s)
- Jiang Zhang
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
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30
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Kolotilin I, Kaldis A, Devriendt B, Joensuu J, Cox E, Menassa R. Production of a subunit vaccine candidate against porcine post-weaning diarrhea in high-biomass transplastomic tobacco. PLoS One 2012; 7:e42405. [PMID: 22879967 PMCID: PMC3411772 DOI: 10.1371/journal.pone.0042405] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 07/05/2012] [Indexed: 11/20/2022] Open
Abstract
Post-weaning diarrhea (PWD) in piglets is a major problem in piggeries worldwide and results in severe economic losses. Infection with Enterotoxigenic Escherichia coli (ETEC) is the key culprit for the PWD disease. F4 fimbriae of ETEC are highly stable proteinaceous polymers, mainly composed of the major structural subunit FaeG, with a capacity to evoke mucosal immune responses, thus demonstrating a potential to act as an oral vaccine against ETEC-induced porcine PWD. In this study we used a transplastomic approach in tobacco to produce a recombinant variant of the FaeG protein, rFaeG(ntd/dsc), engineered for expression as a stable monomer by N-terminal deletion and donor strand-complementation (ntd/dsc). The generated transplastomic tobacco plants accumulated up to 2.0 g rFaeG(ntd/dsc) per 1 kg fresh leaf tissue (more than 1% of dry leaf tissue) and showed normal phenotype indistinguishable from wild type untransformed plants. We determined that chloroplast-produced rFaeG(ntd/dsc) protein retained the key properties of an oral vaccine, i.e. binding to porcine intestinal F4 receptors (F4R), and inhibition of the F4-possessing (F4+) ETEC attachment to F4R. Additionally, the plant biomass matrix was shown to delay degradation of the chloroplast-produced rFaeG(ntd/dsc) in gastrointestinal conditions, demonstrating a potential to function as a shelter-vehicle for vaccine delivery. These results suggest that transplastomic plants expressing the rFaeG(ntd/dsc) protein could be used for production and, possibly, delivery of an oral vaccine against porcine F4+ ETEC infections. Our findings therefore present a feasible approach for developing an oral vaccination strategy against porcine PWD.
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Affiliation(s)
- Igor Kolotilin
- Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
| | - Angelo Kaldis
- Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
| | - Bert Devriendt
- Laboratory of Veterinary Immunology, Faculty of Veterinary Medicine, Gent University, Merelbeke, Belgium
| | - Jussi Joensuu
- VTT Technical Research Centre of Finland, Espoo, Finland
| | - Eric Cox
- Laboratory of Veterinary Immunology, Faculty of Veterinary Medicine, Gent University, Merelbeke, Belgium
| | - Rima Menassa
- Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
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31
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Kanesaki Y, Imamura S, Minoda A, Tanaka K. External light conditions and internal cell cycle phases coordinate accumulation of chloroplast and mitochondrial transcripts in the red alga Cyanidioschyzon merolae. DNA Res 2012; 19:289-303. [PMID: 22518007 PMCID: PMC3372377 DOI: 10.1093/dnares/dss013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 03/14/2012] [Indexed: 01/08/2023] Open
Abstract
The mitochondria and chloroplasts in plant cells are originated from bacterial endosymbioses, and they still replicate their own genome and divide in a similar manner as their ancestors did. It is thus likely that the organelle transcription is coordinated with its proliferation cycle. However, this possibility has not extensively been explored to date, because in most plant cells there are many mitochondria and chloroplasts that proliferate asynchronously. It is generally believed that the gene transfer from the organellar to nuclear genome has enabled nuclear control of the organelle functions during the evolution of eukaryotic plant cells. Nevertheless, no significant relationship has been reported between the organelle transcriptome and the host cell cycle even in Chlamydomonas reinhardtii. While the organelle proliferation cycle is not coordinated with the cell cycle in vascular plants, in the unicellular red alga Cyanidioschyzon merolae that contains only one mitochondrion, one chloroplast, and one nucleus per cell, each of the organelles is known to proliferate at a specific phase of the cell cycle. Here, we show that the expression of most of the organelle genes is highly coordinated with the cell cycle phases as well as with light regimes in clustering analyses. In addition, a strong correlation was observed between the gene expression profiles in the mitochondrion and chloroplast, resulting in the identification of a network of functionally related genes that are co-expressed during organelle proliferation.
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Affiliation(s)
- Yu Kanesaki
- Genome Research Center, Nodai Research Institute, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo156-8502, Japan
- Laboratory of Molecular Genetics, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Sousuke Imamura
- Laboratory of Molecular Genetics, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
- Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo112-8551, Japan
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1-29 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Ayumi Minoda
- Laboratory of Molecular Genetics, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi, Tokyo192-0392, Japan
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Japan
| | - Kan Tanaka
- Laboratory of Molecular Genetics, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1-29 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo, Chiba 271-8510, Japan
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Inka Borchers AM, Gonzalez-Rabade N, Gray JC. Increased accumulation and stability of rotavirus VP6 protein in tobacco chloroplasts following changes to the 5' untranslated region and the 5' end of the coding region. PLANT BIOTECHNOLOGY JOURNAL 2012; 10:422-34. [PMID: 22257338 DOI: 10.1111/j.1467-7652.2011.00675.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Rotavirus is the main cause of gastroenteritis in children worldwide, and the World Health Organisation has recommended that a rotavirus vaccine should be included in all infant immunization programmes. VP6 is the most immunogenic rotavirus subunit and is a potential target for an oral subunit vaccine. VP6 accumulated at up to 3% of total soluble protein in the young leaves of transplastomic tobacco plants, but the protein was unstable and was lost as the leaves aged. The aim of this study was to alter the 5'-untranslated region (5'-UTR) and the 5' end of the coding region of VP6 cDNA in an attempt to increase the expression and stability of VP6 protein in tobacco chloroplasts. The inclusion of the 5'-UTR from gene 10 of bacteriophage T7 (T7g10) and the addition of 15 nucleotides, encoding five additional amino acid residues, at the 5' end of the coding region increased the expression to >15% of total leaf protein and stabilized the protein in ageing leaves. Plants containing VP6 expression constructs with the rbcL 5'-UTR and with the native VP6 5' end of the coding region produced VP6 protein at only 1.9% of total leaf protein. Both the T7g10 5'-UTR and the additional 15 nucleotides increased transcript accumulation and translational efficiency compared with VP6 constructs containing the rbcL 5'-UTR. The VP6 protein produced from all gene constructs appeared to be susceptible to proteolytic processing at its N-terminal region. However, in all transplastomic lines, VP6 proteins assembled into the trimeric form found in the rotavirus capsid.
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Affiliation(s)
- A-M Inka Borchers
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
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33
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Segretin ME, Lentz EM, Wirth SA, Morgenfeld MM, Bravo-Almonacid FF. Transformation of Solanum tuberosum plastids allows high expression levels of β-glucuronidase both in leaves and microtubers developed in vitro. PLANTA 2012; 235:807-18. [PMID: 22071556 DOI: 10.1007/s00425-011-1541-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 10/21/2011] [Indexed: 05/03/2023]
Abstract
Plastid genome transformation offers an attractive methodology for transgene expression in plants, but for potato, only expression of gfp transgene (besides the selective gene aadA) has been published. We report here successful expression of β-glucuronidase in transplastomic Solanum tuberosum (var. Desiree) plants, with accumulation levels for the recombinant protein of up to 41% of total soluble protein in mature leaves. To our knowledge, this is the highest expression level reported for a heterologous protein in S. tuberosum. Accumulation of the recombinant protein in soil-grown minitubers was very low, as described in previous reports. Interestingly, microtubers developed in vitro showed higher accumulation of β-glucuronidase. As light exposure during their development could be the trigger for this high accumulation, we analyzed the effect of light on β-glucuronidase accumulation in transplastomic tubers. Exposure to light for 8 days increased β-glucuronidase accumulation in soil-grown tubers, acting as a light-inducible expression system for recombinant protein accumulation in tuber plastids. In this paper we show that plastid transformation in potato allows the highest recombinant protein accumulation in foliar tissue described so far for this food crop. We also demonstrate that in tubers high accumulation is possible and depends on light exposure. Because tubers have many advantages as protein storage organs, these results could lead to new recombinant protein production schemes based on potato.
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Affiliation(s)
- María Eugenia Segretin
- Laboratorio de Biotecnología Vegetal, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular-INGEBI-CONICET, Vuelta de Obligado 2490, 2do. Piso, C1428ADN, Ciudad Autónoma de Buenos Aires, Argentina.
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Rosales-Mendoza S, Paz-Maldonado LMT, Soria-Guerra RE. Chlamydomonas reinhardtii as a viable platform for the production of recombinant proteins: current status and perspectives. PLANT CELL REPORTS 2012; 31:479-94. [PMID: 22080228 DOI: 10.1007/s00299-011-1186-8] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 10/31/2011] [Accepted: 11/01/2011] [Indexed: 05/03/2023]
Abstract
Chlamydomonas reinhardtii has many advantages compared with traditional systems for the molecular farming of recombinant proteins. These include low production costs, rapid scalability at pilot level, absence of human pathogens and the ability to fold and assemble complex proteins accurately. Currently, the successful expression of several proteins with pharmaceutical relevance has been reported from the nuclear and the chloroplastic genome of this alga, demonstrating its usefulness for biotechnological applications. However, several factors affect the level of recombinant protein expression in Chlamydomonas such as enhancer elements, codon dependency, sensitivity to proteases and transformation-associated genotypic modification. The present review outlines a number of strategies to increase protein yields and summarizes recent achievements in algal protein production including biopharmaceuticals such as vaccines, antibodies, hormones and enzymes with implications on health-related approaches. The current status of bioreactor developments for algal culture and the challenges of scale-up and optimization processes are also discussed.
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Affiliation(s)
- Sergio Rosales-Mendoza
- Laboratorio de Biofarmacéuticos Recombinantes, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava 6, 78210 San Luis Potosí, SLP, Mexico.
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Tangphatsornruang S, Birch-Machin I, Newell CA, Gray JC. The effect of different 3' untranslated regions on the accumulation and stability of transcripts of a gfp transgene in chloroplasts of transplastomic tobacco. PLANT MOLECULAR BIOLOGY 2011; 76:385-96. [PMID: 20859755 DOI: 10.1007/s11103-010-9689-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Accepted: 09/07/2010] [Indexed: 05/11/2023]
Abstract
The 3' untranslated region (3' UTR) of transcripts is a major determinant of transcript stability in plastids and plays an important role in regulating gene expression. In order to compare the effect of different 3' UTRs on transgene expression in tobacco chloroplasts, the 3' UTRs from the tobacco chloroplast rbcL, psbA, petD and rpoA genes and the terminator region of the Escherichia coli rrnB operon were inserted downstream of the gfp reporter gene under the control of the psbA promoter, and the constructs were introduced into the plastid genome by particle bombardment. RNA-gel blot analysis of homoplasmic transplastomic plants identified gfp transcripts of ~1.0 and ~1.4 kb from all constructs and showed that plants expressing gfp with the rrnB terminator contained 4 times more gfp transcripts than plants expressing gfp with the rbcL and rpoA 3' UTRs. The amounts of transcripts accumulated roughly correlated with the half-life of the transcripts, determined by RNA-gel blot analysis of transcripts present in leaves treated with actinomycin D to prevent continued transcription of the chimeric gfp genes. Transcripts containing the 3' region of rrnB were most stable, with half-lives of ~43 h, considerably longer than the half-lives of the other ~1.0 kb gfp transcripts (13-26 h). Immunoblot analysis with antibodies to GFP indicated that all plants contained about the same amount of GFP (~0.2% total soluble protein), suggesting either that translation was limited by something other than the amount of transcript or that the 3' UTR was affecting translation.
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Li W, Ruf S, Bock R. Chloramphenicol acetyltransferase as selectable marker for plastid transformation. PLANT MOLECULAR BIOLOGY 2011; 76:443-51. [PMID: 20721602 DOI: 10.1007/s11103-010-9678-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Accepted: 08/06/2010] [Indexed: 05/07/2023]
Abstract
Chloroplast transformation remains a demanding technique and is still restricted to relatively few plant species. The limited availability of selectable marker genes and the lack of selection markers that would be universally applicable to all plant species represent some of the most serious technical problems involved in extending the species range of plastid transformation. Here we report the development of the chloramphenicol acetyltransferase gene cat as a new selectable marker for plastid transformation. We show that, by selecting for chloramphenicol resistance, tobacco chloroplast transformants are readily obtained. Transplastomic lines quickly reach the homoplasmic state (typically in one additional regeneration round), accumulate the chloramphenicol acetyltransferase enzyme to high levels and transmit their plastid transgenes maternally into the next generation. No spontaneous antibiotic resistance mutants appear upon chloramphenicol selection. Several lines of evidence support the assumption that plant mitochondria are also sensitive to chloramphenicol suggesting that the chloramphenicol acetyltransferase may be a good candidate selectable marker for plant mitochondrial transformation.
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Affiliation(s)
- Weimin Li
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
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Mulo P, Sakurai I, Aro EM. Strategies for psbA gene expression in cyanobacteria, green algae and higher plants: from transcription to PSII repair. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1817:247-57. [PMID: 21565160 DOI: 10.1016/j.bbabio.2011.04.011] [Citation(s) in RCA: 161] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 04/06/2011] [Accepted: 04/07/2011] [Indexed: 11/26/2022]
Abstract
The Photosystem (PS) II of cyanobacteria, green algae and higher plants is prone to light-induced inactivation, the D1 protein being the primary target of such damage. As a consequence, the D1 protein, encoded by the psbA gene, is degraded and re-synthesized in a multistep process called PSII repair cycle. In cyanobacteria, a small gene family codes for the various, functionally distinct D1 isoforms. In these organisms, the regulation of the psbA gene expression occurs mainly at the level of transcription, but the expression is fine-tuned by regulation of translation elongation. In plants and green algae, the D1 protein is encoded by a single psbA gene located in the chloroplast genome. In chloroplasts of Chlamydomonas reinhardtii the psbA gene expression is strongly regulated by mRNA processing, and particularly at the level of translation initiation. In chloroplasts of higher plants, translation elongation is the prevalent mechanism for regulation of the psbA gene expression. The pre-existing pool of psbA transcripts forms translation initiation complexes in plant chloroplasts even in darkness, while the D1 synthesis can be completed only in the light. Replacement of damaged D1 protein requires also the assistance by a number of auxiliary proteins, which are encoded by the nuclear genome in green algae and higher plants. Nevertheless, many of these chaperones are conserved between prokaryotes and eukaryotes. Here, we describe the specific features and fundamental differences of the psbA gene expression and the regeneration of the PSII reaction center protein D1 in cyanobacteria, green algae and higher plants. This article is part of a Special Issue entitled Photosystem II.
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Affiliation(s)
- Paula Mulo
- Department of Biochemistry and Food Chemistry, University of Turku, Finland.
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Zhang XH, Webb J, Huang YH, Lin L, Tang RS, Liu A. Hybrid Rubisco of tomato large subunits and tobacco small subunits is functional in tobacco plants. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2011; 180:480-8. [PMID: 21421395 DOI: 10.1016/j.plantsci.2010.11.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Revised: 11/07/2010] [Accepted: 11/09/2010] [Indexed: 05/08/2023]
Abstract
Biogenesis of functional ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in plants requires specific assembly in the chloroplast of the imported, cytosol-synthesized small subunits (SS) with the chloroplast-made large subunits (LS). Accumulating evidence indicates that chloroplasts (plastids) generally have a low tolerance for assembling foreign or modified Rubisco. To explore Rubisco engineering, we created two lines of transplastomic tobacco plants whose rbcL gene was replaced by tomato-derived rbcL: plant LLS2 with Rubisco composed of tobacco SS and Q437R LS and plant LLS4 with a hybrid Rubisco of tobacco SS and tomato LS (representing four substitutions of Y226F, A230T, S279T and Q437R from tobacco LS). Plant LLS2 exhibited similar phenotypes as the wild type. Plant LLS4 showed lower chlorophyll and Rubisco levels particularly in young emerging leaves, lower photosynthesis rates and biomass during early stages of development, but was able to reach reproductive maturity and somewhat wild type-like phenotype under ambient CO₂ condition. In vitro assays detected similar carboxylase activity and RuBP affinity in LLS2 and LLS4 plants as in wild type. Our studies demonstrated that tomato LS was sufficiently assembled with tobacco SS into functional Rubisco. The hybrid Rubisco of tomato LS and tobacco SS can drive photosynthesis that supports photoautotrophic growth and reproduction of tobacco plants under ambient CO₂ and light conditions. We discuss the effect of these residue substitutions on Rubisco activity and the possible attribution of chlorophyll deficiency to the in planta photosynthesis performance in the hybrid Rubisco plants.
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Affiliation(s)
- Xing-Hai Zhang
- Department of Biological Sciences, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431, USA.
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Farran I, McCarthy-Suárez I, Río-Manterola F, Mansilla C, Lasarte JJ, Mingo-Castel AM. The vaccine adjuvant extra domain A from fibronectin retains its proinflammatory properties when expressed in tobacco chloroplasts. PLANTA 2010; 231:977-90. [PMID: 20108000 DOI: 10.1007/s00425-010-1102-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Accepted: 01/08/2010] [Indexed: 05/28/2023]
Abstract
We previously showed that recombinant extra domain A from fibronectin (EDA) purified from Escherichia coli was able to bind to toll-like receptor 4 (TLR4) and stimulate production of proinflammatory cytokines by dendritic cells. Because EDA could be used as an adjuvant for vaccine development, we aimed to express it from the tobacco plastome, a promising strategy in molecular farming. To optimize the amount of recombinant EDA (rEDA) in tobacco leaves, different downstream sequences were evaluated as potential fusion tags. Plants generated by tobacco plastid transformation accumulated rEDA at levels up to 2% of the total cellular protein (equivalent to approximately 0.3 mg/g fresh weight) when translationally fused to the first 15 amino acids of green fluorescence protein (GFP). The recombinant adjuvant could be purified from tobacco leaves using a simple procedure, involving ammonium sulfate precipitation and anion exchange chromatography. Purified protein was able to induce production of tumour necrosis factor-alpha (TNF-alpha) either by bone marrow-derived dendritic cells or THP-1 monocytes. The rEDA produced in tobacco leaves was also able to induce upregulation of CD54 and CD86 maturation markers on dendritic cells, suggesting that the rEDA retains the proinflammatory properties of the EDA produced in E. coli and thus could be used as an adjuvant in vaccination against infectious agents and cancer. Taken together, these results demonstrate that chloroplasts are an attractive production vehicle for the expression of this protein vaccine adjuvant.
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Affiliation(s)
- Inmaculada Farran
- Instituto de Agrobiotecnología, Universidad Pública de Navarra-CSIC-Gobierno de Navarra, Campus Arrosadía, 31006 Pamplona, Spain,
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Madesis P, Osathanunkul M, Georgopoulou U, Gisby MF, Mudd EA, Nianiou I, Tsitoura P, Mavromara P, Tsaftaris A, Day A. A hepatitis C virus core polypeptide expressed in chloroplasts detects anti-core antibodies in infected human sera. J Biotechnol 2010; 145:377-86. [PMID: 19969031 DOI: 10.1016/j.jbiotec.2009.12.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 11/27/2009] [Accepted: 12/01/2009] [Indexed: 01/19/2023]
Abstract
Hepatitis C virus (HCV) is a major disease agent affecting approximately 3% of the world's population. Expression in plant chloroplasts enables low-cost production of the conserved HCV core protein used in diagnostic tests to combat virus spread in developing countries with high infection rates. The bactericidal activity of the 21 kDa precore protein hinders cloning the core gene in plastid expression cassettes, which are active in bacteria due to the similarities between bacterial and plastid promoters and ribosome binding sites. This was overcome by using a topology-dependent expression cassette containing tandem rrn and psbA plastid promoters, whose activity was shown to be dependent on temperature. The viral core gene and a codon-optimised gene encoding a C-terminal truncated 16 kDa core polypeptide were expressed in tobacco chloroplasts. The codon-optimised gene increased monocistronic core mRNA levels by at least 2-fold and core polypeptides by over 5-fold, relative to the native viral gene. Expression of the 16 kDa core polypeptide was stable in leaves of different ages. Anti-core antibodies in HCV-infected human sera were detected by the 16 kDa core polypeptide in total leaf protein fractionated on Western blots providing a first step towards developing a chloroplast-based HCV diagnostic method.
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Affiliation(s)
- P Madesis
- Faculty of Life Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
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Advances in chloroplast engineering. J Genet Genomics 2009; 36:387-98. [PMID: 19631913 DOI: 10.1016/s1673-8527(08)60128-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 04/30/2009] [Accepted: 05/04/2009] [Indexed: 11/21/2022]
Abstract
The chloroplast is a pivotal organelle in plant cells and eukaryotic algae to carry out photosynthesis, which provides the primary source of the world's food. The expression of foreign genes in chloroplasts offers several advantages over their expression in the nucleus: high-level expression, transgene stacking in operons and a lack of epigenetic interference allowing stable transgene expression. In addition, transgenic chloroplasts are generally not transmitted through pollen grains because of the cytoplasmic localization. In the past two decades, great progress in chloroplast engineering has been made. In this paper, we review and highlight recent studies of chloroplast engineering, including chloroplast transformation procedures, controlled expression of plastid transgenes in plants, the expression of foreign genes for improvement of plant traits, the production of biopharmaceuticals, metabolic pathway engineering in plants, plastid transformation to study RNA editing, and marker gene excision system.
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Barone P, Zhang XH, Widholm JM. Tobacco plastid transformation using the feedback-insensitive anthranilate synthase [alpha]-subunit of tobacco (ASA2) as a new selectable marker. JOURNAL OF EXPERIMENTAL BOTANY 2009; 60:3195-202. [PMID: 19553372 PMCID: PMC2718221 DOI: 10.1093/jxb/erp160] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Revised: 04/17/2009] [Accepted: 04/20/2009] [Indexed: 05/23/2023]
Abstract
Genetic engineering of chloroplasts normally requires the stable introduction of bacterial derived antibiotic or herbicide-resistance genes as selective markers. Ecological and health concerns have been raised due to the presence of such genes within the environment or the food supply. One way to overcome this issue is the use of plant genes able to confer a metabolic or developmental advantage to the transformed cells manipulating the plant's biosynthetic pathways. We explored the feasibility of using, for plastid transformation, the selection system based on the feedback-insensitive anthranilate synthase (AS) alpha-subunit gene of tobacco (ASA2) as a new selective marker and the indole analogue 4-methylindole (4MI) or the tryptophan analogue 7-methyl-DL-tryptophan (7MT) as the selection agents. An expression cassette containing Prrn-ASA2 was effectively integrated into the region between accD and ycf4 of the tobacco plastome by the biolistic process. Plastid transgenic plants were obtained on medium supplemented with 300 microM 7MT or 4MI. Transplastomic plants showed normal phenotype and fertility and the resistance to the selection agents 7MT and 4MI was transmitted maternally. The plastid transformed lines also exhibited a higher level of AS enzyme activity that was less sensitive to Trp-feedback inhibition and, consequently, increased free Trp levels in leaves about 7-fold.
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Affiliation(s)
- Pierluigi Barone
- University of Illinois, Department of Crop Sciences, Edward R. Madigan Lab, 1201 W Gregory Dr, Urbana, IL 61801, USA.
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Site-specific binding of a PPR protein defines and stabilizes 5' and 3' mRNA termini in chloroplasts. EMBO J 2009; 28:2042-52. [PMID: 19424177 DOI: 10.1038/emboj.2009.121] [Citation(s) in RCA: 272] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 03/26/2009] [Indexed: 12/30/2022] Open
Abstract
Chloroplast mRNA populations are characterized by overlapping transcripts derived by processing from polycistronic precursors. The mechanisms and functional significance of these processing events are poorly understood. We describe a pentatricopeptide repeat (PPR) protein, PPR10, whose binding defines mRNA segments derived from two transcription units in maize chloroplasts. PPR10 interacts in vivo and in vitro with two intergenic RNA regions of similar sequence. The processed 5' and 3' RNA termini in these regions overlap by approximately 25 nucleotides. The PPR10-binding sites map precisely to these overlapping sequences, and PPR10 is required specifically for the accumulation of RNAs with these termini. These findings show that PPR10 serves as a barrier to RNA decay from either the 5' or 3' direction and that a bound protein provides an alternative to an RNA hairpin as a barrier to 3' exonucleases. The results imply that protein 'caps' at both 5' and 3' ends can define the termini of chloroplast mRNA segments. These results, together with recent insights into bacterial RNA decay, suggest a unifying model for the biogenesis of chloroplast transcript populations and for the determinants of chloroplast mRNA stability.
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Daniell H, Ruiz G, Denes B, Sandberg L, Langridge W. Optimization of codon composition and regulatory elements for expression of human insulin like growth factor-1 in transgenic chloroplasts and evaluation of structural identity and function. BMC Biotechnol 2009; 9:33. [PMID: 19344517 PMCID: PMC2678116 DOI: 10.1186/1472-6750-9-33] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Accepted: 04/03/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Transgenic chloroplasts are potential bioreactors for recombinant protein production, especially for achievement of high levels of protein expression and proper folding. Production of therapeutic proteins in leaves provides transgene containment by elimination of reproductive structures. Therefore, in this study, human Insulin like Growth Factor-1 is expressed in transgenic chloroplasts for evaluation of structural identity and function. RESULTS Expression of the synthetic Insulin like Growth Factor 1 gene (IGF-1s, 60% AT) was observed in transformed E. coli. However, no native IGF-1 gene (IGF-1n, 41% AT) product was detected in the western blots in E. coli. Site-specific integration of the transgenes into the tobacco chloroplast genome was confirmed after transformation using PCR. Southern blot analysis confirmed that the transgenic lines were homoplasmic. The transgenic plant lines had IGF-1s expression levels of 11.3% of total soluble protein (TSP). The IGF-1n plants contained 9.5% TSP as IGF-1n, suggesting that the chloroplast translation machinery is more flexible than E. coli in codon preference and usage. The expression of IGF-1 was increased up to 32% TSP under continuous illumination by the chloroplast light regulatory elements. IgG-Sepharose affinity column chromatographic separation of Z domain containing chloroplast derived IGF-1 protein, single and two dimensional electrophoresis methods and mass spectrometer analysis confirmed the identity of human IGF-1 in transgenic chloroplasts. Two spots analyzed from 2-D focusing/phoresis acrylamide gel showed the correct amino acid sequence of human IGF-1 and the S. aureus Z-tag. Cell proliferation assays in human HU-3 cells demonstrated the biological activity of chloroplast derived IGF-1 even in the presence of the S. aureus Z tag. CONCLUSION This study demonstrates that the human Insulin like Growth Factor-1 expressed in transgenic chloroplasts is identical to the native protein and is fully functional. The ability to use plant chloroplasts as bioreactors to generate proteins of great economic value that retain their biological activity is an exciting and achievable goal that appears to be within our grasp.
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Affiliation(s)
- Henry Daniell
- Department of Molecular Biology and Microbiology, University of Central Florida, College of Medicine, Biomolecular Science Building, Room 336, Orlando, FL 32816-2364, USA
| | - Gricel Ruiz
- Department of Molecular Biology and Microbiology, University of Central Florida, College of Medicine, Biomolecular Science Building, Room 336, Orlando, FL 32816-2364, USA
| | - Bela Denes
- Center for Health Disparities and Molecular Medicine, 161 Mortensen Hall, Loma Linda University, Loma Linda, CA 92350, USA
| | - Laurence Sandberg
- Department of Biochemistry, Loma Linda University, Loma Linda, CA, 92350, USA
| | - William Langridge
- Center for Health Disparities and Molecular Medicine, 161 Mortensen Hall, Loma Linda University, Loma Linda, CA 92350, USA
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Baecker JJ, Sneddon JC, Hollingsworth MJ. Efficient translation in chloroplasts requires element(s) upstream of the putative ribosome binding site from atpI. AMERICAN JOURNAL OF BOTANY 2009; 96:627-636. [PMID: 21628219 DOI: 10.3732/ajb.0800259] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Thousands of proteins make up a chloroplast, but fewer than 100 are encoded by the chloroplast genome. Despite this low number, expression of chloroplast-encoded genes is essential for plant survival. Every chloroplast has its own gene expression system with a major regulatory point at the initiation of protein synthesis (translation). In chloroplasts, most protein-encoding genes contain elements resembling the ribosome binding sites (RBS) found in prokaryotes. In vitro, these putative chloroplast ribosome binding sequences vary in their ability to support translation. Here we report results from an investigation into effects of the predicted RBS for the tobacco chloroplast atpI gene on translation in vivo. Two reporter constructs, differing only in their 5'-untranslated regions (5'UTRs) were stably incorporated into tobacco chloroplast genomes and their expression analyzed. One 5'UTR was derived from the wild-type (WT) atpI gene. The second, Holo-substitution (Holo-sub), had nonchloroplast sequence replacing all wild-type nucleotides, except for the putative RBS. The abundance of reporter RNA was the same for both 5'UTRs. However, translation controlled by Holo-sub was less than 4% that controlled by WT. These in vivo experiments support the idea that translation initiation in land plant chloroplasts depends on 5'UTR elements outside the putative RBS.
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Affiliation(s)
- Joshua J Baecker
- Department of Biological Sciences, SUNY at Buffalo, Buffalo, New York 14260 USA
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Oey M, Lohse M, Kreikemeyer B, Bock R. Exhaustion of the chloroplast protein synthesis capacity by massive expression of a highly stable protein antibiotic. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 57:436-45. [PMID: 18939966 DOI: 10.1111/j.1365-313x.2008.03702.x] [Citation(s) in RCA: 210] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Plastids (chloroplasts) possess an enormous capacity to synthesize and accumulate foreign proteins. Here we have maximized chloroplast protein production by over-expressing a proteinaceous antibiotic against pathogenic group A and group B streptococci from the plastid genome. The antibiotic, a phage lytic protein, accumulated to enormously high levels (>70% of the plant's total soluble protein), and proved to be extremely stable in chloroplasts. This massive over-expression exhausted the protein synthesis capacity of the chloroplast such that the production of endogenous plastid-encoded proteins was severely compromised. Our data suggest that this is due to translational rather than transcriptional limitation of gene expression. We also show that the chloroplast-produced protein antibiotic efficiently kills the target bacteria. These unrivaled expression levels, together with the chloroplast's insensitivity to enzymes that degrade bacterial cell walls and the elimination of the need to remove bacterial endotoxins by costly purification procedures, indicate that this is an effective plant-based production platform for next-generation antibiotics, which are urgently required to keep pace with rapidly emerging bacterial resistance.
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Affiliation(s)
- Melanie Oey
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
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Jaffé B, Kovács K, Andras C, Bódi Z, Liu Z, Fray RG. Methylation of chloroplast DNA does not affect viability and maternal inheritance in tobacco and may provide a strategy towards transgene containment. PLANT CELL REPORTS 2008; 27:1377-84. [PMID: 18536921 PMCID: PMC2468316 DOI: 10.1007/s00299-008-0567-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Revised: 04/30/2008] [Accepted: 05/26/2008] [Indexed: 05/10/2023]
Abstract
We report the integration of a type II restriction-methylase, mFokI, into the tobacco chloroplast genome and we demonstrate that the introduced enzyme effectively directs the methylation of its target sequence in vivo and does not affect maternal inheritance. We further report the transformation of tobacco with an E. coli dcm methylase targeted to plastids and we demonstrate efficient cytosine methylation of the plastid genome. Both adenosine methylation of FokI sites and cytosine methylation of dcm sites appeared phenotypically neutral. The ability to tolerate such plastid genome methylation is a pre-requisite for a proposed plant transgene containment system. In such a system, a chloroplast located, maternally inherited restriction methylase would provide protection from a nuclear-encoded, plastid targeted restriction endonuclease. As plastids are not paternally inherited in most crop species, pollen from such plants would carry the endonuclease transgene but not the corresponding methylase; the consequence of this should be containment of all nuclear transgenes, as pollination will only be viable in crosses to the appropriate transplastomic maternal background.
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Affiliation(s)
- Benjamin Jaffé
- Plant Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Katalin Kovács
- Plant Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Calin Andras
- Plant Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Zsuzsanna Bódi
- Plant Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Zheng Liu
- Plant Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Rupert G. Fray
- Plant Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
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Farran I, Río-Manterola F, Iñiguez M, Gárate S, Prieto J, Mingo-Castel AM. High-density seedling expression system for the production of bioactive human cardiotrophin-1, a potential therapeutic cytokine, in transgenic tobacco chloroplasts. PLANT BIOTECHNOLOGY JOURNAL 2008; 6:516-27. [PMID: 18384506 DOI: 10.1111/j.1467-7652.2008.00334.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Histidine-tagged human cardiotrophin-1 (hCT-1), a recently discovered cytokine with excellent therapeutic potential, was expressed in tobacco chloroplasts under the transcriptional and translational control of two different promoters (rrn and psbA) and 5'-untranslated regions (5'-UTRs) (psbA and phage T7 gene 10). The psbA 5'-UTR promotes recombinant hCT-1 (rhCT-1) accumulation in chloroplasts at higher levels (eight-fold) than those obtained for the phage T7 gene 10 5'-UTR, regardless of the promoter used, indicating that the correct choice of translational control element is most important for protein production in chloroplasts. The maximum level of rhCT-1 achieved was 1.14 mg/g fresh weight (equivalent to 5% of total soluble protein) with the psbA promoter and 5'-UTR in young leaves harvested after 32 h of continuous light, although the bioactivity was significantly lower (approximately 35%) than that of commercial hCT-1. However, harvesting in the dark or after 12 h of light did not result in a significant decrease in the bioactivity of rhCT-1, suggesting that 32 h of over-lighting affects the biological activity of rhCT-1. Because high levels of rhCT-1 accumulation took place mainly in young leaves, it is proposed that seedlings should be used in a 'closed system' unit, yielding up to 3.2 kg per year of rhCT-1. This amount would be sufficient to meet the estimated annual worldwide needs of hCT-1 for liver transplantation surgery in a cost-effective manner. Furthermore, our strategy is an environmentally friendly method for the production of plant-based biopharmaceuticals.
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Affiliation(s)
- Imma Farran
- Instituto de Agrobiotecnología, UPNA-CSIC-Gobierno de Navarra, Campus Arrosadía, 31006 Pamplona, Spain
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