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Raza A, Siddique KHM, Hu Z. Chloroplast gene control: unlocking RNA thermometer mechanisms in photosynthetic systems. TRENDS IN PLANT SCIENCE 2024; 29:623-625. [PMID: 38311501 DOI: 10.1016/j.tplants.2024.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/16/2024] [Accepted: 01/23/2024] [Indexed: 02/06/2024]
Abstract
RNA thermometers offer straightforward, protein-independent methods to regulate gene expression at the post-transcriptional level. In this context, Chung and colleagues have discovered a revolutionary RNA thermometer in the chloroplast genome of Chlamydomonas reinhardtii. This will facilitate temperature-driven control of inducible transgene expression for biotechnology applications in plant and algal systems.
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Affiliation(s)
- Ali Raza
- Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Guangdong Technology Research Center for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China; College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China; Shenzhen Collaborative Innovation Public Service Platform for Marine Algae Industry, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Kadambot H M Siddique
- The UWA Institute of Agriculture, The University of Western Australia, Crawley, Perth 6009, Australia
| | - Zhangli Hu
- Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Guangdong Technology Research Center for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China; Shenzhen Collaborative Innovation Public Service Platform for Marine Algae Industry, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China.
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2
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Mirzaee M, Leung A, Parulekar M, Candia A, Matsuoka A, Lutz KA, Maliga P. Seed plastids: A novel platform for recombinant protein expression. PLANT BIOTECHNOLOGY JOURNAL 2024. [PMID: 38803087 DOI: 10.1111/pbi.14369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/11/2024] [Accepted: 04/22/2024] [Indexed: 05/29/2024]
Affiliation(s)
- Malihe Mirzaee
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, USA
| | - Alyssa Leung
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, USA
| | - Mugdha Parulekar
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, USA
| | - Ana Candia
- Department of Biology, Farmingdale State College, Farmingdale, New York, USA
| | - Aki Matsuoka
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, USA
| | - Kerry A Lutz
- Department of Biology, Farmingdale State College, Farmingdale, New York, USA
| | - Pal Maliga
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, USA
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3
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Kwok van der Giezen F, Honkanen S, Colas des Francs-Small C, Bond C, Small I. Applications of Synthetic Pentatricopeptide Repeat Proteins. PLANT & CELL PHYSIOLOGY 2024; 65:503-515. [PMID: 38035801 PMCID: PMC11094755 DOI: 10.1093/pcp/pcad150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/20/2023] [Accepted: 11/29/2023] [Indexed: 12/02/2023]
Abstract
RNA-binding proteins play integral roles in the regulation of essential processes in cells and as such are attractive targets for engineering to manipulate gene expression at the RNA level. Expression of transcripts in chloroplasts and mitochondria is heavily regulated by pentatricopeptide repeat (PPR) proteins. The diverse roles of PPR proteins and their naturally modular architecture make them ideal candidates for engineering. Synthetic PPR proteins are showing great potential to become valuable tools for controlling the expression of plastid and mitochondrial transcripts. In this review, by 'synthetic', we mean both rationally modified natural PPR proteins and completely novel proteins designed using the principles learned from their natural counterparts. We focus on the many different applications of synthetic PPR proteins, covering both their use in basic research to learn more about protein-RNA interactions and their use to achieve specific outcomes in RNA processing and the control of gene expression. We describe the challenges associated with the design, construction and deployment of synthetic PPR proteins and provide perspectives on how they might be assembled and used in future biotechnology applications.
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Affiliation(s)
- Farley Kwok van der Giezen
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - Suvi Honkanen
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - Catherine Colas des Francs-Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - Charles Bond
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - Ian Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
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4
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Chung KP, Loiacono FV, Neupert J, Wu M, Bock R. An RNA thermometer in the chloroplast genome of Chlamydomonas facilitates temperature-controlled gene expression. Nucleic Acids Res 2023; 51:11386-11400. [PMID: 37855670 PMCID: PMC10639063 DOI: 10.1093/nar/gkad816] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/01/2023] [Accepted: 09/20/2023] [Indexed: 10/20/2023] Open
Abstract
Riboregulators such as riboswitches and RNA thermometers provide simple, protein-independent tools to control gene expression at the post-transcriptional level. In bacteria, RNA thermometers regulate protein synthesis in response to temperature shifts. Thermometers outside of the bacterial world are rare, and in organellar genomes, no RNA thermometers have been identified to date. Here we report the discovery of an RNA thermometer in a chloroplast gene of the unicellular green alga Chlamydomonas reinhardtii. The thermometer, residing in the 5' untranslated region of the psaA messenger RNA forms a hairpin-type secondary structure that masks the Shine-Dalgarno sequence at 25°C. At 40°C, melting of the secondary structure increases accessibility of the Shine-Dalgarno sequence to initiating ribosomes, thus enhancing protein synthesis. By targeted nucleotide substitutions and transfer of the thermometer into Escherichia coli, we show that the secondary structure is necessary and sufficient to confer the thermometer properties. We also demonstrate that the thermometer provides a valuable tool for inducible transgene expression from the Chlamydomonas plastid genome, in that a simple temperature shift of the algal culture can greatly increase recombinant protein yields.
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Affiliation(s)
- Kin Pan Chung
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - F Vanessa Loiacono
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Juliane Neupert
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Mengting Wu
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
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5
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LaManna L, Chou CH, Lei H, Barton ER, Maliga P. Chloroplast transformation for bioencapsulation and oral delivery using the immunoglobulin G fragment crystallizable (Fc) domain. Sci Rep 2023; 13:18916. [PMID: 37919321 PMCID: PMC10622566 DOI: 10.1038/s41598-023-45698-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 10/23/2023] [Indexed: 11/04/2023] Open
Abstract
Proinsulin Like Growth Factor I (prolGF-I) and myostatin (Mstn) regulate muscle regeneration and mass when intravenously delivered. We tested if chloroplast bioencapsulated forms of these proteins may serve as a non-invasive means of drug delivery through the digestive system. We created tobacco (Nicotiana tabacum) plants carrying GFP-Fc1, proIGF-I-Fc1, and Mstn-Fc1 fusion genes, in which fusion with the immunoglobulin G Fc domain improved both protein stability and absorption in the small intestine. No transplastomic plants were obtained with the Mstn-Fc1 gene, suggesting that the protein is toxic to plant cells. proIGF-I-Fc1 protein levels were too low to enable in vivo testing. However, GFP-Fc1 accumulated at a high level, enabling evaluation of chloroplast-made Fc fusion proteins for oral delivery. Tobacco leaves were lyophilized for testing in a mouse system. We report that the orally administered GFP-Fc1 fusion protein (5.45 µg/g GFP-Fc1) has been taken up by the intestinal epithelium cells, evidenced by confocal microscopy. GFP-Fc1 subsequently entered the circulation where it was detected by ELISA. Data reported here confirm that chloroplast expression and oral administration of lyophilized leaves is a potential delivery system of therapeutic proteins fused with Fc1, with the advantage that the proteins may be stored at room temperature.
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Affiliation(s)
- Lisa LaManna
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Chih-Hsuan Chou
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, 32611, USA
| | - Hanqin Lei
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, 32611, USA
| | - Elisabeth R Barton
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, 32611, USA.
| | - Pal Maliga
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA.
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, 08901, USA.
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6
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Zhang Y, Tian L, Lu C. Chloroplast gene expression: Recent advances and perspectives. PLANT COMMUNICATIONS 2023; 4:100611. [PMID: 37147800 PMCID: PMC10504595 DOI: 10.1016/j.xplc.2023.100611] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 04/11/2023] [Accepted: 05/01/2023] [Indexed: 05/07/2023]
Abstract
Chloroplasts evolved from an ancient cyanobacterial endosymbiont more than 1.5 billion years ago. During subsequent coevolution with the nuclear genome, the chloroplast genome has remained independent, albeit strongly reduced, with its own transcriptional machinery and distinct features, such as chloroplast-specific innovations in gene expression and complicated post-transcriptional processing. Light activates the expression of chloroplast genes via mechanisms that optimize photosynthesis, minimize photodamage, and prioritize energy investments. Over the past few years, studies have moved from describing phases of chloroplast gene expression to exploring the underlying mechanisms. In this review, we focus on recent advances and emerging principles that govern chloroplast gene expression in land plants. We discuss engineering of pentatricopeptide repeat proteins and its biotechnological effects on chloroplast RNA research; new techniques for characterizing the molecular mechanisms of chloroplast gene expression; and important aspects of chloroplast gene expression for improving crop yield and stress tolerance. We also discuss biological and mechanistic questions that remain to be answered in the future.
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Affiliation(s)
- Yi Zhang
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Lin Tian
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Congming Lu
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China.
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7
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Small I, Melonek J, Bohne AV, Nickelsen J, Schmitz-Linneweber C. Plant organellar RNA maturation. THE PLANT CELL 2023; 35:1727-1751. [PMID: 36807982 PMCID: PMC10226603 DOI: 10.1093/plcell/koad049] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/05/2023] [Accepted: 01/17/2023] [Indexed: 05/30/2023]
Abstract
Plant organellar RNA metabolism is run by a multitude of nucleus-encoded RNA-binding proteins (RBPs) that control RNA stability, processing, and degradation. In chloroplasts and mitochondria, these post-transcriptional processes are vital for the production of a small number of essential components of the photosynthetic and respiratory machinery-and consequently for organellar biogenesis and plant survival. Many organellar RBPs have been functionally assigned to individual steps in RNA maturation, often specific to selected transcripts. While the catalog of factors identified is ever-growing, our knowledge of how they achieve their functions mechanistically is far from complete. This review summarizes the current knowledge of plant organellar RNA metabolism taking an RBP-centric approach and focusing on mechanistic aspects of RBP functions and the kinetics of the processes they are involved in.
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Affiliation(s)
- Ian Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley 6009, Australia
| | - Joanna Melonek
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley 6009, Australia
| | | | - Jörg Nickelsen
- Department of Molecular Plant Sciences, LMU Munich, 82152 Martinsried, Germany
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8
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Winckler LI, Dissmeyer N. Molecular determinants of protein half-life in chloroplasts with focus on the Clp protease system. Biol Chem 2023; 404:499-511. [PMID: 36972025 DOI: 10.1515/hsz-2022-0320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 03/09/2023] [Indexed: 03/29/2023]
Abstract
Abstract
Proteolysis is an essential process to maintain cellular homeostasis. One pathway that mediates selective protein degradation and which is in principle conserved throughout the kingdoms of life is the N-degron pathway, formerly called the ‘N-end rule’. In the cytosol of eukaryotes and prokaryotes, N-terminal residues can be major determinants of protein stability. While the eukaryotic N-degron pathway depends on the ubiquitin proteasome system, the prokaryotic counterpart is driven by the Clp protease system. Plant chloroplasts also contain such a protease network, which suggests that they might harbor an organelle specific N-degron pathway similar to the prokaryotic one. Recent discoveries indicate that the N-terminal region of proteins affects their stability in chloroplasts and provides support for a Clp-mediated entry point in an N-degron pathway in plastids. This review discusses structure, function and specificity of the chloroplast Clp system, outlines experimental approaches to test for an N-degron pathway in chloroplasts, relates these aspects into general plastid proteostasis and highlights the importance of an understanding of plastid protein turnover.
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Affiliation(s)
- Lioba Inken Winckler
- Department of Plant Physiology and Protein Metabolism Laboratory, University of Osnabruck, Barbarastrasse 11, D-49076 Osnabruck, Germany
- Center of Cellular Nanoanalytics (CellNanOs), Barbarastrasse 11, D-49076 Osnabruck, Germany
- Faculty of Biology, University of Osnabruck, Barbarastrasse 11, D-49076 Osnabruck, Germany
| | - Nico Dissmeyer
- Department of Plant Physiology and Protein Metabolism Laboratory, University of Osnabruck, Barbarastrasse 11, D-49076 Osnabruck, Germany
- Center of Cellular Nanoanalytics (CellNanOs), Barbarastrasse 11, D-49076 Osnabruck, Germany
- Faculty of Biology, University of Osnabruck, Barbarastrasse 11, D-49076 Osnabruck, Germany
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9
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Lee K, Kang H. Engineering of pentatricopeptide repeat proteins in organellar gene regulation. FRONTIERS IN PLANT SCIENCE 2023; 14:1144298. [PMID: 36938060 PMCID: PMC10014608 DOI: 10.3389/fpls.2023.1144298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Affiliation(s)
- Kwanuk Lee
- Department of Biology, Jeju National University, Jeju, Republic of Korea
| | - Hunseung Kang
- Department of Applied Biology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, Republic of Korea
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10
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McDowell R, Small I, Bond CS. Synthetic PPR proteins as tools for sequence-specific targeting of RNA. Methods 2022; 208:19-26. [DOI: 10.1016/j.ymeth.2022.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 09/29/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022] Open
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11
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Yang S, Deng Y, Li S. Advances in plastid transformation for metabolic engineering in higher plants. ABIOTECH 2022; 3:224-232. [PMID: 36313931 PMCID: PMC9590572 DOI: 10.1007/s42994-022-00083-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 09/09/2022] [Indexed: 03/12/2023]
Abstract
The plastid (chloroplast) genome of higher plants is an appealing target for metabolic engineering via genetic transformation. Although the bacterial-type plastid genome is small compared with the nuclear genome, it can accommodate large quantities of foreign genes that precisely integrate through homologous recombination. Engineering complex metabolic pathways in plants often requires simultaneous and concerted expression of multiple transgenes, the possibility of stacking several transgenes in synthetic operons makes the transplastomic approach amazing. The potential for extraordinarily high-level transgene expression, absence of epigenetic gene silencing and transgene containment due to the exclusion of plastids from pollen transmission in most angiosperm species further add to the attractiveness of plastid transformation technology. This minireview describes recent advances in expanding the toolboxes for plastid genome engineering, and highlights selected high-value metabolites produced using transplastomic plants, including artemisinin, astaxanthin and paclitaxel.
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Affiliation(s)
- Sheng Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Yi Deng
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Shengchun Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 China
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12
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Maliga P. Engineering the plastid and mitochondrial genomes of flowering plants. NATURE PLANTS 2022; 8:996-1006. [PMID: 36038655 DOI: 10.1038/s41477-022-01227-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Engineering the plastid genome based on homologous recombination is well developed in a few model species. Homologous recombination is also the rule in mitochondria, but transformation of the mitochondrial genome has not been realized in the absence of selective markers. The application of transcription activator-like (TAL) effector-based tools brought about a dramatic change because they can be deployed from nuclear genes and targeted to plastids or mitochondria by an N-terminal targeting sequence. Recognition of the target site in the organellar genomes is ensured by the modular assembly of TALE repeats. In this paper, I review the applications of TAL effector nucleases and TAL effector cytidine deaminases for gene deletion, base editing and mutagenesis in plastids and mitochondria. I also review emerging technologies such as post-transcriptional RNA modification to regulate gene expression, Agrobacterium- and nanoparticle-mediated organellar genome transformation, and self-replicating organellar vectors as production platforms.
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Affiliation(s)
- Pal Maliga
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, USA.
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA.
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13
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Sugita M. An Overview of Pentatricopeptide Repeat (PPR) Proteins in the Moss Physcomitrium patens and Their Role in Organellar Gene Expression. PLANTS 2022; 11:plants11172279. [PMID: 36079663 PMCID: PMC9459714 DOI: 10.3390/plants11172279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/29/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022]
Abstract
Pentatricopeptide repeat (PPR) proteins are one type of helical repeat protein that are widespread in eukaryotes. In particular, there are several hundred PPR members in flowering plants. The majority of PPR proteins are localized in the plastids and mitochondria, where they play a crucial role in various aspects of RNA metabolism at the post-transcriptional and translational steps during gene expression. Among the early land plants, the moss Physcomitrium (formerly Physcomitrella) patens has at least 107 PPR protein-encoding genes, but most of their functions remain unclear. To elucidate the functions of PPR proteins, a reverse-genetics approach has been applied to P. patens. To date, the molecular functions of 22 PPR proteins were identified as essential factors required for either mRNA processing and stabilization, RNA splicing, or RNA editing. This review examines the P. patens PPR gene family and their current functional characterization. Similarities and a diversity of functions of PPR proteins between P. patens and flowering plants and their roles in the post-transcriptional regulation of organellar gene expression are discussed.
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Affiliation(s)
- Mamoru Sugita
- Graduate School of Informatics, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
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14
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Santana I, Jeon SJ, Kim HI, Islam MR, Castillo C, Garcia GFH, Newkirk GM, Giraldo JP. Targeted Carbon Nanostructures for Chemical and Gene Delivery to Plant Chloroplasts. ACS NANO 2022; 16:12156-12173. [PMID: 35943045 DOI: 10.1021/acsnano.2c02714] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Nanotechnology approaches for improving the delivery efficiency of chemicals and molecular cargoes in plants through plant biorecognition mechanisms remain relatively unexplored. We developed targeted carbon-based nanomaterials as tools for precise chemical delivery (carbon dots, CDs) and gene delivery platforms (single-walled carbon nanotubes, SWCNTs) to chloroplasts, key organelles involved in efforts to improve plant photosynthesis, assimilation of nutrients, and delivery of agrochemicals. A biorecognition approach of coating the nanomaterials with a rationally designed chloroplast targeting peptide improved the delivery of CDs with molecular baskets (TP-β-CD) for delivery of agrochemicals and of plasmid DNA coated SWCNT (TP-pATV1-SWCNT) from 47% to 70% and from 39% to 57% of chloroplasts in leaves, respectively. Plants treated with TP-β-CD (20 mg/L) and TP-pATV1-SWCNT (2 mg/L) had a low percentage of dead cells, 6% and 8%, respectively, similar to controls without nanoparticles, and no permanent cell and chloroplast membrane damage after 5 days of exposure. However, targeted nanomaterials transiently increased leaf H2O2 (0.3225 μmol gFW-1) above control plant levels (0.03441 μmol gFW-1) but within the normal range reported in land plants. The increase in leaf H2O2 levels was associated with oxidative damage in whole plant cell DNA, a transient effect on chloroplast DNA, and a decrease in leaf chlorophyll content (-17%) and carbon assimilation rates at saturation light levels (-32%) with no impact on photosystem II quantum yield. This work provides targeted delivery approaches for carbon-based nanomaterials mediated by biorecognition and a comprehensive understanding of their impact on plant cell and molecular biology for engineering safer and efficient agrochemical and biomolecule delivery tools.
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Affiliation(s)
- Israel Santana
- Department of Botany and Plant Sciences, University of California-Riverside, Riverside, California 92521, United States
| | - Su-Ji Jeon
- Department of Botany and Plant Sciences, University of California-Riverside, Riverside, California 92521, United States
| | - Hye-In Kim
- Department of Botany and Plant Sciences, University of California-Riverside, Riverside, California 92521, United States
| | - Md Reyazul Islam
- Department of Botany and Plant Sciences, University of California-Riverside, Riverside, California 92521, United States
| | - Christopher Castillo
- Department of Botany and Plant Sciences, University of California-Riverside, Riverside, California 92521, United States
| | - Gail F H Garcia
- Department of Botany and Plant Sciences, University of California-Riverside, Riverside, California 92521, United States
| | - Gregory M Newkirk
- Department of Microbiology and Plant Pathology, University of California-Riverside, Riverside, California 92521, United States
| | - Juan Pablo Giraldo
- Department of Botany and Plant Sciences, University of California-Riverside, Riverside, California 92521, United States
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15
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Bock R. Transplastomic approaches for metabolic engineering. CURRENT OPINION IN PLANT BIOLOGY 2022; 66:102185. [PMID: 35183927 DOI: 10.1016/j.pbi.2022.102185] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 06/14/2023]
Abstract
The plastid (chloroplast) genome of seed plants represents an attractive target of metabolic pathway engineering by genetic transformation. Although the plastid genome is relatively small, it can accommodate large amounts of foreign DNA that precisely integrates via homologous recombination, and is largely excluded from pollen transmission due to the maternal mode of plastid inheritance. Since the engineering of metabolic pathways often requires the expression of multiple transgenes, the possibility to conveniently stack transgenes in synthetic operons makes the transplastomic technology particularly appealing in the area of metabolic engineering. Absence of epigenetic gene silencing mechanisms from plastids and the possibility to achieve high transgene expression levels further add to the attractiveness of plastid genome transformation. This review focuses on engineering principles and available tools for the transplastomic expression of enzymes and pathways, and highlights selected recent applications in metabolic engineering.
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Affiliation(s)
- Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany.
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16
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Shahar N, Elman T, Williams-Carrier R, Ben-Zvi O, Yacoby I, Barkan A. Use of plant chloroplast RNA-binding proteins as orthogonal activators of chloroplast transgenes in the green alga Chlamydomonas reinhardtii. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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17
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Huang D, Kosentka PZ, Liu W. Synthetic biology approaches in regulation of targeted gene expression. CURRENT OPINION IN PLANT BIOLOGY 2021; 63:102036. [PMID: 33930839 DOI: 10.1016/j.pbi.2021.102036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 05/15/2023]
Abstract
Synthetic biology approaches are highly sought-after to facilitate the regulation of targeted gene expression in plants for functional genomics research and crop trait improvement. To date, synthetic regulation of gene expression predominantly focuses at the transcription level via engineering of synthetic promoters and transcription factors, while pioneering examples have started to emerge for synthetic regulation of gene expression at the levels of mRNA stability, translation, and protein degradation. This review discusses recent advances in plant synthetic biology for the regulation of gene expression at multiple levels, and highlights their future directions.
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Affiliation(s)
- Debao Huang
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27607, USA
| | - Pawel Z Kosentka
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27607, USA
| | - Wusheng Liu
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27607, USA.
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18
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Zhu X, Liu X, Liu T, Wang Y, Ahmed N, Li Z, Jiang H. Synthetic biology of plant natural products: From pathway elucidation to engineered biosynthesis in plant cells. PLANT COMMUNICATIONS 2021; 2:100229. [PMID: 34746761 PMCID: PMC8553972 DOI: 10.1016/j.xplc.2021.100229] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 04/11/2021] [Accepted: 08/06/2021] [Indexed: 05/10/2023]
Abstract
Plant natural products (PNPs) are the main sources of drugs, food additives, and new biofuels and have become a hotspot in synthetic biology. In the past two decades, the engineered biosynthesis of many PNPs has been achieved through the construction of microbial cell factories. Alongside the rapid development of plant physiology, genetics, and plant genetic modification techniques, hosts have now expanded from single-celled microbes to complex plant systems. Plant synthetic biology is an emerging field that combines engineering principles with plant biology. In this review, we introduce recent advances in the biosynthetic pathway elucidation of PNPs and summarize the progress of engineered PNP biosynthesis in plant cells. Furthermore, a future vision of plant synthetic biology is proposed. Although we are still a long way from overcoming all the bottlenecks in plant synthetic biology, the ascent of this field is expected to provide a huge opportunity for future agriculture and industry.
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Affiliation(s)
- Xiaoxi Zhu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Xiaonan Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Tian Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Life Science and Technology College, Guangxi University, Nanning, Guangxi 530004, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Yina Wang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
- Yunnan Agricultural University, Kunming, Yunnan 650201, China
| | - Nida Ahmed
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Zhichao Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Huifeng Jiang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
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19
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The radish Ogura fertility restorer impedes translation elongation along its cognate CMS-causing mRNA. Proc Natl Acad Sci U S A 2021; 118:2105274118. [PMID: 34433671 DOI: 10.1073/pnas.2105274118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The control of messenger RNA (mRNA) translation has been increasingly recognized as a key regulatory step for gene control, but clear examples in eukaryotes are still scarce. Nucleo-cytoplasmic male sterilities (CMS) represent ideal genetic models to dissect genetic interactions between the mitochondria and the nucleus in plants. This trait is determined by specific mitochondrial genes and is associated with a pollen sterility phenotype that can be suppressed by nuclear genes known as restorer-of-fertility (Rf). In this study, we focused on the Ogura CMS system in rapeseed and showed that reversion to male sterility by the PPR-B fertility restorer (also called Rfo) occurs through a specific translation inhibition of the mitochondria-encoded CMS-causing mRNA orf138 We also demonstrate that PPR-B binds within the coding sequence of orf138 and acts as a ribosome blocker to specifically impede translation elongation along the orf138 mRNA. Rfo is the first recognized fertility restorer shown to act this way. These observations will certainly facilitate the development of synthetic fertility restorers for CMS systems in which efficient natural Rfs are lacking.
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20
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Valkov VT, Gargano D, Cardi T, Scotti N. Plastid Transformation in Potato: An Important Source of Nutrition and Industrial Materials. Methods Mol Biol 2021; 2317:247-256. [PMID: 34028773 DOI: 10.1007/978-1-0716-1472-3_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
For a long time, plastid transformation has been a routine technology only in tobacco due to lack of effective selection and regeneration protocols, and, for some species, due to inefficient recombination using heterologous flanking regions in transformation vectors. Nevertheless, the availability of this technology to economically important crops offers new possibilities in plant breeding to manage pathogen resistance or improve nutritional value. Herein we describe an efficient plastid transformation protocol for potato (Solanum tuberosum subsp. tuberosum), achieved by the optimization of the tissue culture procedures and using transformation vectors carrying homologous potato flanking sequences. This protocol allowed to obtain up to one shoot per shot, an efficiency comparable to that usually accomplished in tobacco. Further, the method described in this chapter has been successfully used to regenerate potato transplastomic plants expressing recombinant GFP protein in chloroplasts and amyloplasts or long double-stranded RNAs for insect pest control.
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Affiliation(s)
- Vladimir T Valkov
- CNR-IBBR, National Research Council of Italy, Institute of Biosciences and BioResources, Research Division Portici, Portici (NA), Italy
| | - Daniela Gargano
- CNR-IBBR, National Research Council of Italy, Institute of Biosciences and BioResources, Research Division Portici, Portici (NA), Italy
| | - Teodoro Cardi
- CNR-IBBR, National Research Council of Italy, Institute of Biosciences and BioResources, Research Division Portici, Portici (NA), Italy.,CREA-OF, Research Centre for Vegetable and Ornamental Crops, Pontecagnano (SA), Italy
| | - Nunzia Scotti
- CNR-IBBR, National Research Council of Italy, Institute of Biosciences and BioResources, Research Division Portici, Portici (NA), Italy.
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21
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Frangedakis E, Guzman-Chavez F, Rebmann M, Markel K, Yu Y, Perraki A, Tse SW, Liu Y, Rever J, Sauret-Gueto S, Goffinet B, Schneider H, Haseloff J. Construction of DNA Tools for Hyperexpression in Marchantia Chloroplasts. ACS Synth Biol 2021; 10:1651-1666. [PMID: 34097383 PMCID: PMC8296666 DOI: 10.1021/acssynbio.0c00637] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Chloroplasts are attractive platforms for synthetic biology applications since they are capable of driving very high levels of transgene expression, if mRNA production and stability are properly regulated. However, plastid transformation is a slow process and currently limited to a few plant species. The liverwort Marchantia polymorpha is a simple model plant that allows rapid transformation studies; however, its potential for protein hyperexpression has not been fully exploited. This is partially due to the fact that chloroplast post-transcriptional regulation is poorly characterized in this plant. We have mapped patterns of transcription in Marchantia chloroplasts. Furthermore, we have obtained and compared sequences from 51 bryophyte species and identified putative sites for pentatricopeptide repeat protein binding that are thought to play important roles in mRNA stabilization. Candidate binding sites were tested for their ability to confer high levels of reporter gene expression in Marchantia chloroplasts, and levels of protein production and effects on growth were measured in homoplastic transformed plants. We have produced novel DNA tools for protein hyperexpression in this facile plant system that is a test-bed for chloroplast engineering.
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Affiliation(s)
- Eftychios Frangedakis
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Fernando Guzman-Chavez
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Marius Rebmann
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Kasey Markel
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Ying Yu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China
| | - Artemis Perraki
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Sze Wai Tse
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Yang Liu
- Fairy Lake Botanical Garden & Chinese Academy of Sciences, Shenzhen, Guangdong 518004, China
| | - Jenna Rever
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Susanna Sauret-Gueto
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Bernard Goffinet
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut 06269-3043, United States
| | - Harald Schneider
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan 666303, China
| | - Jim Haseloff
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
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22
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Li S, Chang L, Zhang J. Advancing organelle genome transformation and editing for crop improvement. PLANT COMMUNICATIONS 2021; 2:100141. [PMID: 33898977 PMCID: PMC8060728 DOI: 10.1016/j.xplc.2021.100141] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 12/15/2020] [Accepted: 01/01/2021] [Indexed: 05/05/2023]
Abstract
Plant cells contain three organelles that harbor DNA: the nucleus, plastids, and mitochondria. Plastid transformation has emerged as an attractive platform for the generation of transgenic plants, also referred to as transplastomic plants. Plastid genomes have been genetically engineered to improve crop yield, nutritional quality, and resistance to abiotic and biotic stresses, as well as for recombinant protein production. Despite many promising proof-of-concept applications, transplastomic plants have not been commercialized to date. Sequence-specific nuclease technologies are widely used to precisely modify nuclear genomes, but these tools have not been applied to edit organelle genomes because the efficient homologous recombination system in plastids facilitates plastid genome editing. Unlike plastid transformation, successful genetic transformation of higher plant mitochondrial genome transformation was tested in several research group, but not successful to date. However, stepwise progress has been made in modifying mitochondrial genes and their transcripts, thus enabling the study of their functions. Here, we provide an overview of advances in organelle transformation and genome editing for crop improvement, and we discuss the bottlenecks and future development of these technologies.
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Affiliation(s)
- Shengchun Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Ling Chang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Jiang Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China
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23
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Generation, analysis, and transformation of macro-chloroplast Potato (Solanum tuberosum) lines for chloroplast biotechnology. Sci Rep 2020; 10:21144. [PMID: 33273600 PMCID: PMC7713401 DOI: 10.1038/s41598-020-78237-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 11/19/2020] [Indexed: 12/11/2022] Open
Abstract
Chloroplast biotechnology is a route for novel crop metabolic engineering. The potential bio-confinement of transgenes, the high protein expression and the possibility to organize genes into operons represent considerable advantages that make chloroplasts valuable targets in agricultural biotechnology. In the last 3 decades, chloroplast genomes from a few economically important crops have been successfully transformed. The main bottlenecks that prevent efficient transformation in a greater number of crops include the dearth of proven selectable marker gene-selection combinations and tissue culture methods for efficient regeneration of transplastomic plants. The prospects of increasing organelle size are attractive from several perspectives, including an increase in the surface area of potential targets. As a proof-of-concept, we generated Solanum tuberosum (potato) macro-chloroplast lines overexpressing the tubulin-like GTPase protein gene FtsZ1 from Arabidopsis thaliana. Macro-chloroplast lines exhibited delayed growth at anthesis; however, at the time of harvest there was no significant difference in height between macro-chloroplast and wild-type lines. Macro-chloroplasts were successfully transformed by biolistic DNA-delivery and efficiently regenerated into homoplasmic transplastomic lines. We also demonstrated that macro-chloroplasts accumulate the same amount of heterologous protein than wild-type organelles, confirming efficient usage in plastid engineering. Advantages and limitations of using enlarge compartments in chloroplast biotechnology are discussed.
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24
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Yu Q, Tungsuchat-Huang T, Verma K, Radler MR, Maliga P. Independent translation of ORFs in dicistronic operons, synthetic building blocks for polycistronic chloroplast gene expression. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:2318-2329. [PMID: 32497322 DOI: 10.1111/tpj.14864] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 05/13/2020] [Accepted: 05/21/2020] [Indexed: 06/11/2023]
Abstract
We designed a dicistronic plastid marker system that relies on the plastid's ability to translate polycistronic mRNAs. The identification of transplastomic clones is based on selection for antibiotic resistance encoded in the first open reading frame (ORF) and accumulation of the reporter gene product in tobacco chloroplasts encoded in the second ORF. The antibiotic resistance gene may encode spectinomycin or kanamycin resistance based on the expression of aadA or neo genes, respectively. The reporter gene used in the study is the green fluorescent protein (GFP). The mRNA level depends on the 5'-untranslated region of the first ORF. The protein output depends on the strengths of the ribosome binding, and is proportional with the level of translatable mRNA. Because the dicistronic mRNA is not processed, we could show that protein output from the second ORF is independent from the first ORF. High-level GFP accumulation from the second ORF facilitates identification of transplastomic events under ultraviolet light. Expression of multiple proteins from an unprocessed mRNA is an experimental design that enables predictable protein output from polycistronic mRNAs, expanding the toolkit of plant synthetic biology.
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Affiliation(s)
- Qiguo Yu
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
| | | | - Kanak Verma
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Megan R Radler
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Pal Maliga
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, 08901, USA
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25
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Small ID, Schallenberg-Rüdinger M, Takenaka M, Mireau H, Ostersetzer-Biran O. Plant organellar RNA editing: what 30 years of research has revealed. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:1040-1056. [PMID: 31630458 DOI: 10.1111/tpj.14578] [Citation(s) in RCA: 160] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 09/25/2019] [Accepted: 10/08/2019] [Indexed: 05/21/2023]
Abstract
The central dogma in biology defines the flow of genetic information from DNA to RNA to protein. Accordingly, RNA molecules generally accurately follow the sequences of the genes from which they are transcribed. This rule is transgressed by RNA editing, which creates RNA products that differ from their DNA templates. Analyses of the RNA landscapes of terrestrial plants have indicated that RNA editing (in the form of C-U base transitions) is highly prevalent within organelles (that is, mitochondria and chloroplasts). Numerous C→U conversions (and in some plants also U→C) alter the coding sequences of many of the organellar transcripts and can also produce translatable mRNAs by creating AUG start sites or eliminating premature stop codons, or affect the RNA structure, influence splicing and alter the stability of RNAs. RNA-binding proteins are at the heart of post-transcriptional RNA expression. The C-to-U RNA editing process in plant mitochondria involves numerous nuclear-encoded factors, many of which have been identified as pentatricopeptide repeat (PPR) proteins that target editing sites in a sequence-specific manner. In this review we report on major discoveries on RNA editing in plant organelles, since it was first documented 30 years ago.
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Affiliation(s)
- Ian D Small
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, WA, 6009, Australia
| | - Mareike Schallenberg-Rüdinger
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abt. Molekulare Evolution, University of Bonn, Kirschallee 1, 53115, Bonn, Germany
| | - Mizuki Takenaka
- Department of Botany, Graduate School of Science, Kyoto University, Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Hakim Mireau
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026, Versailles Cedex, France
| | - Oren Ostersetzer-Biran
- Department of Plant and Environmental Sciences, Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus - Givat Ram, Jerusalem, 9190401, Israel
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26
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Gutmann B, Royan S, Schallenberg-Rüdinger M, Lenz H, Castleden IR, McDowell R, Vacher MA, Tonti-Filippini J, Bond CS, Knoop V, Small ID. The Expansion and Diversification of Pentatricopeptide Repeat RNA-Editing Factors in Plants. MOLECULAR PLANT 2020; 13:215-230. [PMID: 31760160 DOI: 10.1016/j.molp.2019.11.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/10/2019] [Accepted: 11/11/2019] [Indexed: 05/08/2023]
Abstract
The RNA-binding pentatricopeptide repeat (PPR) family comprises hundreds to thousands of genes in most plants, but only a few dozen in algae, indicating massive gene expansions during land plant evolution. The nature and timing of these expansions has not been well defined due to the sparse sequence data available from early-diverging land plant lineages. In this study, we exploit the comprehensive OneKP datasets of over 1000 transcriptomes from diverse plants and algae toward establishing a clear picture of the evolution of this massive gene family, focusing on the proteins typically associated with RNA editing, which show the most spectacular variation in numbers and domain composition across the plant kingdom. We characterize over 2 250 000 PPR motifs in over 400 000 proteins. In lycophytes, polypod ferns, and hornworts, nearly 10% of expressed protein-coding genes encode putative PPR editing factors, whereas they are absent from algae and complex-thalloid liverworts. We show that rather than a single expansion, most land plant lineages with high numbers of editing factors have continued to generate novel sequence diversity. We identify sequence variations that imply functional differences between PPR proteins in seed plants versus non-seed plants and variations we propose to be linked to seed-plant-specific editing co-factors. Finally, using the sequence variations across the datasets, we develop a structural model of the catalytic DYW domain associated with C-to-U editing and identify a clade of unique DYW variants that are strong candidates as U-to-C RNA-editing factors, given their phylogenetic distribution and sequence characteristics.
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Affiliation(s)
- Bernard Gutmann
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Santana Royan
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Mareike Schallenberg-Rüdinger
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Henning Lenz
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Ian R Castleden
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Rose McDowell
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Michael A Vacher
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Julian Tonti-Filippini
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Charles S Bond
- School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia
| | - Volker Knoop
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Ian D Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Perth 6009, WA, Australia; School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, WA, Australia.
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27
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Rojas M, Yu Q, Williams-Carrier R, Maliga P, Barkan A. Engineered PPR proteins as inducible switches to activate the expression of chloroplast transgenes. NATURE PLANTS 2019; 5:505-511. [PMID: 31036912 DOI: 10.1038/s41477-019-0412-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 03/22/2019] [Indexed: 05/08/2023]
Abstract
The engineering of plant genomes presents exciting opportunities to modify agronomic traits and to produce high-value products in plants. Expression of foreign proteins from transgenes in the chloroplast genome offers advantages that include the capacity for prodigious protein output, the lack of transgene silencing and the ability to express multicomponent pathways from polycistronic mRNA. However, there remains a need for robust methods to regulate plastid transgene expression. We designed orthogonal activators that boost the expression of chloroplast transgenes harbouring cognate cis-elements. Our system exploits the programmable RNA sequence specificity of pentatricopeptide repeat proteins and their native functions as activators of chloroplast gene expression. When expressed from nuclear transgenes, the engineered proteins stimulate the expression of plastid transgenes by up to ~40-fold, with maximal protein abundance approaching that of Rubisco. This strategy provides a means to regulate and optimize the expression of foreign genes in chloroplasts and to avoid deleterious effects of their products on plant growth.
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Affiliation(s)
- Margarita Rojas
- Institute of Molecular Biology, University of Oregon, Eugene, OR, USA
| | - Qiguo Yu
- Waksman Institute of Microbiology, Rutgers, the State University of New Jersey, Piscataway, NJ, USA
| | | | - Pal Maliga
- Waksman Institute of Microbiology, Rutgers, the State University of New Jersey, Piscataway, NJ, USA
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, OR, USA.
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28
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Quétier F. Building biofactories with PPR10s. NATURE PLANTS 2019; 5:453-454. [PMID: 31040445 DOI: 10.1038/s41477-019-0426-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- Francis Quétier
- Biology Department, Paris-Saclay University, Evry, France.
- GIP-Genopole, Evry, France.
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