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Owens NA, Anborgh PH, Kolotilin I. Chromatography affinity resin with photosynthetically-sourced protein A ligand. Sci Rep 2024; 14:8714. [PMID: 38622266 PMCID: PMC11018848 DOI: 10.1038/s41598-024-59266-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 04/09/2024] [Indexed: 04/17/2024] Open
Abstract
Green, photosynthesizing plants can be proficiently used as cost-effective, single-use, fully biodegradable bioreactors for environmentally-friendly production of a variety of valuable recombinant proteins. Being near-infinitely scalable and most energy-efficient in generating biomass, plants represent profoundly valid alternatives to conventionally used stationary fermenters. To validate this, we produced a plastome-engineered tobacco bioreactor line expressing a recombinant variant of the protein A from Staphylococcus aureus, an affinity ligand widely useful in antibody purification processes, reaching accumulation levels up to ~ 250 mg per 1 kg of fresh leaf biomass. Chromatography resin manufactured from photosynthetically-sourced recombinant protein A ligand conjugated to agarose beads demonstrated the innate pH-driven ability to bind and elute IgG-type antibodies and allowed one-step efficient purification of functional monoclonal antibodies from the supernatants of the producing hybridomas. The results of this study emphasize the versatility of plant-based recombinant protein production and illustrate its vast potential in reducing the cost of diverse biotechnological applications, particularly the downstream processing and purification of monoclonal antibodies.
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Affiliation(s)
- Nisha A Owens
- The School of Applied Science and Technology, Fanshawe College, London, ON, Canada
| | - Pieter H Anborgh
- The School of Applied Science and Technology, Fanshawe College, London, ON, Canada
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2
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Chai X, Wang X, Rong L, Luo M, Yuan L, Li Q, He B, Jiang J, Ji D, Ouyang M, Lu Q, Zhang L, Rochaix JD, Chi W. The translocon protein FtsHi1 is an ATP-dependent DNA/RNA helicase that prevents R-loop accumulation in chloroplasts. THE NEW PHYTOLOGIST 2024; 241:2209-2226. [PMID: 38084045 DOI: 10.1111/nph.19470] [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: 04/10/2023] [Accepted: 11/22/2023] [Indexed: 02/09/2024]
Abstract
R-loops, three-stranded nucleic acid structures consisting of a DNA: RNA hybrid and displaced single-stranded DNA, play critical roles in gene expression and genome stability. How R-loop homeostasis is integrated into chloroplast gene expression remains largely unknown. We found an unexpected function of FtsHi1, an inner envelope membrane-bound AAA-ATPase in chloroplast R-loop homeostasis of Arabidopsis thaliana. Previously, this protein was shown to function as a component of the import motor complex for nuclear-encoded chloroplast proteins. However, this study provides evidence that FtsHi1 is an ATP-dependent helicase that efficiently unwinds both DNA-DNA and DNA-RNA duplexes, thereby preventing R-loop accumulation. Over-accumulation of R-loops could impair chloroplast transcription but not necessarily genome integrity. The dual function of FtsHi1 in both protein import and chloroplast gene expression may be important to coordinate the biogenesis of nuclear- and chloroplast-encoded subunits of multi-protein photosynthetic complexes. This study suggests a mechanical link between protein import and R-loop homeostasis in chloroplasts of higher plants.
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Affiliation(s)
- Xin Chai
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Xiushun Wang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Liwei Rong
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Manfei Luo
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Li Yuan
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qiuxin Li
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Baoye He
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Jingjing Jiang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Daili Ji
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Min Ouyang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Qingtao Lu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Lixin Zhang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, 85 Minglun St., Kaifeng, 475001, China
| | - Jean-David Rochaix
- Department of Molecular Biology, University of Geneva, 1211, Geneva, Switzerland
- Department of Plant Biology, University of Geneva, 1211, Geneva, Switzerland
| | - Wei Chi
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
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3
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Palomar VM, Jaksich S, Fujii S, Kuciński J, Wierzbicki AT. High-resolution map of plastid-encoded RNA polymerase binding patterns demonstrates a major role of transcription in chloroplast gene expression. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 111:1139-1151. [PMID: 35765883 PMCID: PMC9540123 DOI: 10.1111/tpj.15882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 06/24/2022] [Accepted: 06/24/2022] [Indexed: 05/16/2023]
Abstract
Plastids contain their own genomes, which are transcribed by two types of RNA polymerases. One of those enzymes is a bacterial-type, multi-subunit polymerase encoded by the plastid genome. The plastid-encoded RNA polymerase (PEP) is required for efficient expression of genes encoding proteins involved in photosynthesis. Despite the importance of PEP, its DNA binding locations have not been studied on the genome-wide scale at high resolution. We established a highly specific approach to detect the genome-wide pattern of PEP binding to chloroplast DNA using plastid chromatin immunoprecipitation-sequencing (ptChIP-seq). We found that in mature Arabidopsis thaliana chloroplasts, PEP has a complex DNA binding pattern with preferential association at genes encoding rRNA, tRNA, and a subset of photosynthetic proteins. Sigma factors SIG2 and SIG6 strongly impact PEP binding to a subset of tRNA genes and have more moderate effects on PEP binding throughout the rest of the genome. PEP binding is commonly enriched on gene promoters, around transcription start sites. Finally, the levels of PEP binding to DNA are correlated with levels of RNA accumulation, which demonstrates the impact of PEP on chloroplast gene expression. Presented data are available through a publicly available Plastid Genome Visualization Tool (Plavisto) at https://plavisto.mcdb.lsa.umich.edu/.
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Affiliation(s)
- V. Miguel Palomar
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborMichigan48109USA
| | - Sarah Jaksich
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborMichigan48109USA
| | - Sho Fujii
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborMichigan48109USA
- Department of Botany, Graduate School of ScienceKyoto UniversityKyoto606‐8502Japan
- Department of Biology, Faculty of Agriculture and Life ScienceHirosaki UniversityHirosaki036‐8561Japan
| | - Jan Kuciński
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborMichigan48109USA
| | - Andrzej T. Wierzbicki
- Department of Molecular, Cellular, and Developmental BiologyUniversity of MichiganAnn ArborMichigan48109USA
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4
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Abstract
Chloroplasts, the sites of photosynthesis and sources of reducing power, are at the core of the success story that sets apart autotrophic plants from most other living organisms. Along with their fellow organelles (e.g., amylo-, chromo-, etio-, and leucoplasts), they form a group of intracellular biosynthetic machines collectively known as plastids. These plant cell constituents have their own genome (plastome), their own (70S) ribosomes, and complete enzymatic equipment covering the full range from DNA replication via transcription and RNA processive modification to translation. Plastid RNA synthesis (gene transcription) involves the collaborative activity of two distinct types of RNA polymerases that differ in their phylogenetic origin as well as their architecture and mode of function. The existence of multiple plastid RNA polymerases is reflected by distinctive sets of regulatory DNA elements and protein factors. This complexity of the plastid transcription apparatus thus provides ample room for regulatory effects at many levels within and beyond transcription. Research in this field offers insight into the various ways in which plastid genes, both singly and groupwise, can be regulated according to the needs of the entire cell. Furthermore, it opens up strategies that allow to alter these processes in order to optimize the expression of desired gene products.
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Affiliation(s)
- Jennifer Ortelt
- Department of Biology and Biotechnology, University of Bochum, Bochum, Germany
| | - Gerhard Link
- Department of Biology and Biotechnology, University of Bochum, Bochum, Germany.
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5
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Li J, Liu H, Xia W, Mu J, Feng Y, Liu R, Yan P, Wang A, Lin Z, Guo Y, Zhu J, Chen X. De Novo Transcriptome Sequencing and the Hypothetical Cold Response Mode of Saussurea involucrata in Extreme Cold Environments. Int J Mol Sci 2017; 18:E1155. [PMID: 28590406 PMCID: PMC5485979 DOI: 10.3390/ijms18061155] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 05/18/2017] [Accepted: 05/23/2017] [Indexed: 11/16/2022] Open
Abstract
Saussurea involucrata grows in high mountain areas covered by snow throughout the year. The temperature of this habitat can change drastically in one day. To gain a better understanding of the cold response signaling pathways and molecular metabolic reactions involved in cold stress tolerance, genome-wide transcriptional analyses were performed using RNA-Seq technologies. A total of 199,758 transcripts were assembled, producing 138,540 unigenes with 46.8 Gb clean data. Overall, 184,416 (92.32%) transcripts were successfully annotated. The 365 transcription factors identified (292 unigenes) belonged to 49 transcription factor families associated with cold stress responses. A total of 343 transcripts on the signal transduction (132 upregulated and 212 downregulated in at least any one of the conditions) were strongly affected by cold temperature, such as the CBL-interacting serine/threonine-protein kinase (CIPKs), receptor-like protein kinases, and protein kinases. The circadian rhythm pathway was activated by cold adaptation, which was necessary to endure the severe temperature changes within a day. There were 346 differentially expressed genes (DEGs) related to transport, of which 138 were upregulated and 22 were downregulated in at least any one of the conditions. Under cold stress conditions, transcriptional regulation, molecular transport, and signal transduction were involved in the adaptation to low temperature in S. involucrata. These findings contribute to our understanding of the adaptation of plants to harsh environments and the survival traits of S. involucrata. In addition, the present study provides insight into the molecular mechanisms of chilling and freezing tolerance.
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Affiliation(s)
- Jin Li
- College of Life Sciences, Shihezi University, Shihezi 832000, China.
| | - Hailiang Liu
- Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai 200065, China.
| | - Wenwen Xia
- College of Life Sciences, Shihezi University, Shihezi 832000, China.
| | - Jianqiang Mu
- College of Life Sciences, Shihezi University, Shihezi 832000, China.
| | - Yujie Feng
- College of Life Sciences, Shihezi University, Shihezi 832000, China.
| | - Ruina Liu
- College of Life Sciences, Shihezi University, Shihezi 832000, China.
| | - Panyao Yan
- ShengTing Bioinformatics Institute, Christiansburg, VA 24073, USA.
| | - Aiying Wang
- College of Life Sciences, Shihezi University, Shihezi 832000, China.
| | - Zhongping Lin
- College of Life Sciences, Shihezi University, Shihezi 832000, China.
- College of Life Sciences, Perking University, Beijing 100871, China.
| | - Yong Guo
- Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Jianbo Zhu
- College of Life Sciences, Shihezi University, Shihezi 832000, China.
| | - Xianfeng Chen
- College of Life Sciences, Shihezi University, Shihezi 832000, China.
- ShengTing Bioinformatics Institute, Christiansburg, VA 24073, USA.
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Tarasenko VI, Katyshev AI, Yakovleva TV, Garnik EY, Chernikova VV, Konstantinov YM, Koulintchenko MV. RPOTmp, an Arabidopsis RNA polymerase with dual targeting, plays an important role in mitochondria, but not in chloroplasts. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:5657-5669. [PMID: 27591433 DOI: 10.1093/jxb/erw327] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In a number of dicotyledonous plants, including Arabidopsis, the transcription of organellar genes is performed by three nuclear-encoded RNA polymerases, RPOTm, RPOTmp, and RPOTp. RPOTmp is a protein with a dual targeting, which is presumably involved in the control of gene expression in both mitochondria and chloroplasts. A previous study of the Arabidopsis insertion rpotmp mutant showed that it has retarded growth and development, altered leaf morphology, changed expression of mitochondrial and probably some chloroplast genes, and decreased activities of the mitochondrial respiratory complexes. To date, there is no clear evidence as to which of these disorders are associated with a lack of RPOTmp in each of the two organelles. The aim of this study was to elucidate the role that this RNA polymerase specifically plays in mitochondria and chloroplasts. Two sets of Arabidopsis transgenic lines with complementation of RPOTmp function in either mitochondria or chloroplasts were obtained. It was found that the recovery of RPOTmp RNA polymerase activity in chloroplasts, although restoring the transcription from the RPOTmp-specific PC promoter, did not lead to compensation of the mutant growth defects. In contrast, the rpotmp plants expressing RPOTmp with mitochondrial targeting restored the level of mitochondrial transcripts and exhibit a phenotype resembling that of the wild-type plants. We conclude that despite its localization in two cell compartments, Arabidopsis RPOTmp plays an important role in mitochondria, but not in chloroplasts.
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Affiliation(s)
- Vladislav I Tarasenko
- Siberian Institute of Plant Physiology and Biochemistry, SB RAS, 132 Lermontov St, Irkutsk, 664033, Russia
| | - Alexander I Katyshev
- Siberian Institute of Plant Physiology and Biochemistry, SB RAS, 132 Lermontov St, Irkutsk, 664033, Russia
| | - Tatiana V Yakovleva
- Siberian Institute of Plant Physiology and Biochemistry, SB RAS, 132 Lermontov St, Irkutsk, 664033, Russia
| | - Elena Y Garnik
- Siberian Institute of Plant Physiology and Biochemistry, SB RAS, 132 Lermontov St, Irkutsk, 664033, Russia
| | - Valentina V Chernikova
- Siberian Institute of Plant Physiology and Biochemistry, SB RAS, 132 Lermontov St, Irkutsk, 664033, Russia
| | - Yuri M Konstantinov
- Siberian Institute of Plant Physiology and Biochemistry, SB RAS, 132 Lermontov St, Irkutsk, 664033, Russia Irkutsk State University, 1 Karl Marx St, Irkutsk, 664003, Russia
| | - Milana V Koulintchenko
- Siberian Institute of Plant Physiology and Biochemistry, SB RAS, 132 Lermontov St, Irkutsk, 664033, Russia
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7
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Muralikrishna N, Srinivas K, Kumar KB, Sadanandam A. Stable plastid transformation in Scoparia dulcis L. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2016; 22:575-581. [PMID: 27924130 PMCID: PMC5120043 DOI: 10.1007/s12298-016-0386-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 09/28/2016] [Accepted: 10/10/2016] [Indexed: 05/16/2023]
Abstract
In the present investigation we report stable plastid transformation in Scoparia dulcis L., a versatile medicinal herb via particle gun method. The vector KNTc, harbouring aadA as a selectable marker and egfp as a reporter gene which were under the control of synthetic promoter pNG1014a, targets inverted repeats, trnR/trnN of the plastid genome. By use of this heterologous vector, recovery of transplastomic lines with suitable selection protocol have been successfully established with overall efficiency of two transgenic lines for 25 bombarded leaf explants. PCR and Southern blot analysis demonstrated stable integration of foreign gene into the target sequences. The results represent a significant advancement of the plastid transformation technology in medicinal plants, which relevantly implements a change over in enhancing and regulating of certain metabolic pathways.
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Affiliation(s)
| | - Kota Srinivas
- Department of Biotechnology, Kakatiya University, Warangal, 506009 India
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8
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Wang D, Qu Z, Adelson DL, Zhu JK, Timmis JN. Transcription of nuclear organellar DNA in a model plant system. Genome Biol Evol 2014; 6:1327-34. [PMID: 24868015 PMCID: PMC4079196 DOI: 10.1093/gbe/evu111] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Endosymbiotic gene transfer from cytoplasmic organelles (chloroplasts and mitochondria) to the nucleus is an ongoing process in land plants. Although the frequency of organelle DNA migration is high, functional gene transfer is rare because a nuclear promoter is thought necessary for activity in the nucleus. Here we show that a chloroplast promoter, 16S rrn, drives nuclear transcription, suggesting that a transferred organellar gene may become active without obtaining a nuclear promoter. Examining the chromatin status of a known de novo chloroplast integrant indicates that plastid DNA inserts into open chromatin and that this relaxed condition is maintained after integration. Transcription of nuclear organelle DNA integrants was explored at the whole genome level by analyzing RNA-seq data of Oryza sativa subsp. japonica, and utilizing sequence polymorphisms to unequivocally discriminate nuclear organelle DNA transcripts from those of bona fide cytoplasmic organelle DNA. Nuclear copies of organelle DNA that are transcribed show a spectrum of transcriptional activity but at comparatively low levels compared with the majority of other nuclear genes.
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Affiliation(s)
- Dong Wang
- Shanghai Center for Plant Stress Biology, Shanghai Institute for Biological Science, Chinese Academy of Sciences, Shanghai, China
| | - Zhipeng Qu
- Discipline of Genetics, School of Molecular and Biomedical Science, The University of Adelaide, South Australia, Australia
| | - David L Adelson
- Discipline of Genetics, School of Molecular and Biomedical Science, The University of Adelaide, South Australia, Australia
| | - Jian-Kang Zhu
- Shanghai Center for Plant Stress Biology, Shanghai Institute for Biological Science, Chinese Academy of Sciences, Shanghai, China
| | - Jeremy N Timmis
- Discipline of Genetics, School of Molecular and Biomedical Science, The University of Adelaide, South Australia, Australia
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9
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Williams-Carrier R, Zoschke R, Belcher S, Pfalz J, Barkan A. A major role for the plastid-encoded RNA polymerase complex in the expression of plastid transfer RNAs. PLANT PHYSIOLOGY 2014; 164:239-48. [PMID: 24246379 PMCID: PMC3875804 DOI: 10.1104/pp.113.228726] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 11/16/2013] [Indexed: 05/18/2023]
Abstract
Chloroplast transcription in land plants relies on collaboration between a plastid-encoded RNA polymerase (PEP) of cyanobacterial ancestry and a nucleus-encoded RNA polymerase of phage ancestry. PEP associates with additional proteins that are unrelated to bacterial transcription factors, many of which have been shown to be important for PEP activity in Arabidopsis (Arabidopsis thaliana). However, the biochemical roles of these PEP-associated proteins are not known. We describe phenotypes conditioned by transposon insertions in genes encoding the maize (Zea mays) orthologs of five such proteins: ZmPTAC2, ZmMurE, ZmPTAC10, ZmPTAC12, and ZmPRIN2. These mutants have similar ivory/virescent pigmentation and similar reductions in plastid ribosomes and photosynthetic complexes. RNA gel-blot and microarray hybridizations revealed numerous changes in plastid transcript populations, many of which resemble those reported for the orthologous mutants in Arabidopsis. However, unanticipated reductions in the abundance of numerous transfer RNAs (tRNAs) dominated the microarray data and were validated on RNA gel blots. The magnitude of the deficiencies for several tRNAs was similar to that of the most severely affected messenger RNAs, with the loss of trnL-UAA being particularly severe. These findings suggest that PEP and its associated proteins are critical for the robust transcription of numerous plastid tRNAs and that this function is essential for the prodigious translation of plastid-encoded proteins that is required during the installation of the photosynthetic apparatus.
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10
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Williams-Carrier R, Zoschke R, Belcher S, Pfalz J, Barkan A. A major role for the plastid-encoded RNA polymerase complex in the expression of plastid transfer RNAs. PLANT PHYSIOLOGY 2014. [PMID: 24246379 DOI: 10.1104/pp.113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Chloroplast transcription in land plants relies on collaboration between a plastid-encoded RNA polymerase (PEP) of cyanobacterial ancestry and a nucleus-encoded RNA polymerase of phage ancestry. PEP associates with additional proteins that are unrelated to bacterial transcription factors, many of which have been shown to be important for PEP activity in Arabidopsis (Arabidopsis thaliana). However, the biochemical roles of these PEP-associated proteins are not known. We describe phenotypes conditioned by transposon insertions in genes encoding the maize (Zea mays) orthologs of five such proteins: ZmPTAC2, ZmMurE, ZmPTAC10, ZmPTAC12, and ZmPRIN2. These mutants have similar ivory/virescent pigmentation and similar reductions in plastid ribosomes and photosynthetic complexes. RNA gel-blot and microarray hybridizations revealed numerous changes in plastid transcript populations, many of which resemble those reported for the orthologous mutants in Arabidopsis. However, unanticipated reductions in the abundance of numerous transfer RNAs (tRNAs) dominated the microarray data and were validated on RNA gel blots. The magnitude of the deficiencies for several tRNAs was similar to that of the most severely affected messenger RNAs, with the loss of trnL-UAA being particularly severe. These findings suggest that PEP and its associated proteins are critical for the robust transcription of numerous plastid tRNAs and that this function is essential for the prodigious translation of plastid-encoded proteins that is required during the installation of the photosynthetic apparatus.
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11
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Abstract
Chloroplasts, the sites of photosynthesis and sources of reducing power, are at the core of the success story that sets apart autotrophic plants from most other living organisms. Along with their fellow organelles (e.g., amylo-, chromo-, etio-, and leucoplasts), they form a group of intracellular biosynthetic machines collectively known as plastids. These plant cell constituents have their own genome (plastome), their own (70S) ribosomes, and complete enzymatic equipment covering the full range from DNA replication via transcription and RNA processive modification to translation. Plastid RNA synthesis (gene transcription) involves the collaborative activity of two distinct types of RNA polymerases that differ in their phylogenetic origin as well as their architecture and mode of function. The existence of multiple plastid RNA polymerases is reflected by distinctive sets of regulatory DNA elements and protein factors. This complexity of the plastid transcription apparatus thus provides ample room for regulatory effects at many levels within and beyond transcription. Research in this field offers insight into the various ways in which plastid genes, both singly and groupwise, can be regulated according to the needs of the entire cell. Furthermore, it opens up strategies that allow to alter these processes in order to optimize the expression of desired gene products.
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Affiliation(s)
- Jennifer Ortelt
- Plant Cell Physiology and Molecular Biology, University of Bochum, Bochum, Germany
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12
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Gimpel JA, Mayfield SP. Analysis of heterologous regulatory and coding regions in algal chloroplasts. Appl Microbiol Biotechnol 2012. [PMID: 23179624 DOI: 10.1007/s00253-012-4580-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The basic photosynthetic apparatus is highly conserved across all photosynthetic organisms, and this conservation can be seen in both protein composition and amino acid sequence. Conservation of regulatory elements also seems possible in chloroplast genes, as many mRNA untranslated regions (UTRs) appear to have similar structural elements. The D1 protein of Photosystem II (psbA gene) is a highly conserved core reaction center protein that shows very similar regulation from cyanobacteria through higher plants. We engineered full and partial psbA genes from a diverse set of photosynthetic organisms into a psbA deficient strain of Chlamydomonas reinhardtii. Analysis of D1 protein accumulation and photosynthetic growth revealed that coding sequences and promoters are interchangeable even between anciently diverged species. On the other hand functional recognition of 5' UTRs is limited to closely related organisms. Furthermore transformation of heterologous promoters and 5' UTRs from the atpA, tufA and psbD genes conferred psbA mRNA accumulation but not translation. Overall, our results show that heterologous D1 proteins can be expressed and complement Photosystem II function in green algae, while RNA regulatory elements appear to be very specific and function only from closely related species. Nonetheless, there is great potential for the expression of heterologous photosynthetic coding sequences for studying and modifying photosynthesis in C. reinhardtii chloroplasts.
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Affiliation(s)
- Javier A Gimpel
- San Diego Center for Algae Biotechnology, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0368, USA
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13
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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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15
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Kusumi K, Sakata C, Nakamura T, Kawasaki S, Yoshimura A, Iba K. A plastid protein NUS1 is essential for build-up of the genetic system for early chloroplast development under cold stress conditions. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 68:1039-50. [PMID: 21981410 DOI: 10.1111/j.1365-313x.2011.04755.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
During early chloroplast differentiation, the regulation of the plastid genetic system including transcription and translation differs greatly from that in the mature chloroplast, suggesting the existence of a stage-dependent mechanism that regulates the chloroplast genetic system during this period. The virescent-1 (v(1)) mutant of rice (Oryza sativa) is temperature-conditional and develops chlorotic leaves under low-temperature conditions. We reported previously that leaf chlorosis in the v(1) mutant is caused by blockage of the activation of the chloroplast genetic system during early leaf development. Here we identify the V(1) gene, which encodes a chloroplast-localized protein NUS1. Accumulation of NUS1 specifically occurred in the pre-emerged immature leaves, and is enhanced by low-temperature treatment. The C-terminus of NUS1 shows structural similarity to the bacterial antitermination factor NusB, which is known to play roles in the regulation of ribosomal RNA transcription. The RNA-immunoprecipitation and gel mobility shift assays indicated that NUS1 binds to several regions of chloroplast RNA including the upstream leader region of the 16S rRNA precursor. In the leaves of the NUS1-deficient mutant, accumulation of chloroplast rRNA during early leaf development was impaired and chloroplast translation/transcription capacity was severely suppressed under low temperature. Our results suggest that NUS1 is involved in the regulation of chloroplast RNA metabolism and promotes the establishment of the plastid genetic system during early chloroplast development under cold stress conditions.
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Affiliation(s)
- Kensuke Kusumi
- Department of Biology, Kyushu University, Fukuoka 812-8581, Japan.
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16
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Lerbs-Mache S. Function of plastid sigma factors in higher plants: regulation of gene expression or just preservation of constitutive transcription? PLANT MOLECULAR BIOLOGY 2011; 76:235-49. [PMID: 21107995 DOI: 10.1007/s11103-010-9714-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Accepted: 11/09/2010] [Indexed: 05/04/2023]
Abstract
Plastid gene expression is rather complex. Transcription is performed by three different RNA polymerases, two of them are nucleus-encoded, monomeric, of the phage-type (named RPOTp and RPOTmp) and one of them is plastid-encoded, multimeric, of the eubacterial-type (named PEP). The activity of the eubacterial-type RNA polymerase is regulated by up to six nucleus-encoded transcription initiation factors of the sigma-type. This complexity of the plastid transcriptional apparatus is not yet well understood and raises the question of whether it is subject to any regulation or just ensures constitutive transcription of the plastid genome. On the other hand, considerable advances have been made during the last years elucidating the role of sigma factors for specific promoter recognition and selected transcription of some plastid genes. Sigma-interacting proteins have been identified and phosphorylation-dependent functional changes of sigma factors have been revealed. The present review aims to summarize these recent advances and to convince the reader that plastid gene expression is regulated on the transcriptional level by sigma factor action.
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Affiliation(s)
- Silva Lerbs-Mache
- Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique, CEA-Grenoble, UMR 5168, Université Joseph Fourier, 17 rue des Martyrs, 38054 Grenoble cedex, France.
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17
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Hotto AM, Huston ZE, Stern DB. Overexpression of a natural chloroplast-encoded antisense RNA in tobacco destabilizes 5S rRNA and retards plant growth. BMC PLANT BIOLOGY 2010; 10:213. [PMID: 20920268 PMCID: PMC3017836 DOI: 10.1186/1471-2229-10-213] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Accepted: 09/29/2010] [Indexed: 05/19/2023]
Abstract
BACKGROUND The roles of non-coding RNAs in regulating gene expression have been extensively studied in both prokaryotes and eukaryotes, however few reports exist as to their roles in organellar gene regulation. Evidence for accumulation of natural antisense RNAs (asRNAs) in chloroplasts comes from the expressed sequence tag database and cDNA libraries, while functional data have been largely obtained from artificial asRNAs. In this study, we used Nicotiana tabacum to investigate the effect on sense strand transcripts of overexpressing a natural chloroplast asRNA, AS5, which is complementary to the region which encodes the 5S rRNA and tRNAArg. RESULTS AS5-overexpressing (AS5ox) plants obtained by chloroplast transformation exhibited slower growth and slightly pale green leaves. Analysis of AS5 transcripts revealed four distinct species in wild-type (WT) and AS5ox plants, and additional AS5ox-specific products. Of the corresponding sense strand transcripts, tRNAArg overaccumulated several-fold in transgenic plants whereas 5S rRNA was unaffected. However, run-on transcription showed that the 5S-trnR region was transcribed four-fold more in the AS5ox plants compared to WT, indicating that overexpression of AS5 was associated with decreased stability of 5S rRNA. In addition, polysome analysis of the transformants showed less 5S rRNA and rbcL mRNA associated with ribosomes. CONCLUSIONS Our results suggest that AS5 can modulate 5S rRNA levels, giving it the potential to affect Chloroplast translation and plant growth. More globally, overexpression of asRNAs via chloroplast transformation may be a useful strategy for defining their functions.
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MESH Headings
- Gene Expression Regulation, Plant
- Phenotype
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/metabolism
- RNA, Antisense/genetics
- RNA, Antisense/metabolism
- RNA, Chloroplast/genetics
- RNA, Chloroplast/metabolism
- RNA, Plant/genetics
- RNA, Plant/metabolism
- RNA, Ribosomal, 5S/genetics
- RNA, Ribosomal, 5S/metabolism
- RNA, Transfer, Arg/genetics
- RNA, Transfer, Arg/metabolism
- Nicotiana/genetics
- Nicotiana/growth & development
- Nicotiana/metabolism
- Transformation, Genetic
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Affiliation(s)
- Amber M Hotto
- Boyce Thompson Institute for Plant Research, Cornell University, Tower Rd., Ithaca, NY 14853, USA
| | - Zoe E Huston
- Riverdale High School, 9727 SW Terwilliger Blvd., Portland, OR 97219, USA
| | - David B Stern
- Boyce Thompson Institute for Plant Research, Cornell University, Tower Rd., Ithaca, NY 14853, USA
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18
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Ruhlman T, Verma D, Samson N, Daniell H. The role of heterologous chloroplast sequence elements in transgene integration and expression. PLANT PHYSIOLOGY 2010; 152:2088-104. [PMID: 20130101 PMCID: PMC2850035 DOI: 10.1104/pp.109.152017] [Citation(s) in RCA: 162] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Accepted: 01/30/2010] [Indexed: 05/15/2023]
Abstract
Heterologous regulatory elements and flanking sequences have been used in chloroplast transformation of several crop species, but their roles and mechanisms have not yet been investigated. Nucleotide sequence identity in the photosystem II protein D1 (psbA) upstream region is 59% across all taxa; similar variation was consistent across all genes and taxa examined. Secondary structure and predicted Gibbs free energy values of the psbA 5' untranslated region (UTR) among different families reflected this variation. Therefore, chloroplast transformation vectors were made for tobacco (Nicotiana tabacum) and lettuce (Lactuca sativa), with endogenous (Nt-Nt, Ls-Ls) or heterologous (Nt-Ls, Ls-Nt) psbA promoter, 5' UTR and 3' UTR, regulating expression of the anthrax protective antigen (PA) or human proinsulin (Pins) fused with the cholera toxin B-subunit (CTB). Unique lettuce flanking sequences were completely eliminated during homologous recombination in the transplastomic tobacco genomes but not unique tobacco sequences. Nt-Ls or Ls-Nt transplastomic lines showed reduction of 80% PA and 97% CTB-Pins expression when compared with endogenous psbA regulatory elements, which accumulated up to 29.6% total soluble protein PA and 72.0% total leaf protein CTB-Pins, 2-fold higher than Rubisco. Transgene transcripts were reduced by 84% in Ls-Nt-CTB-Pins and by 72% in Nt-Ls-PA lines. Transcripts containing endogenous 5' UTR were stabilized in nonpolysomal fractions. Stromal RNA-binding proteins were preferentially associated with endogenous psbA 5' UTR. A rapid and reproducible regeneration system was developed for lettuce commercial cultivars by optimizing plant growth regulators. These findings underscore the need for sequencing complete crop chloroplast genomes, utilization of endogenous regulatory elements and flanking sequences, as well as optimization of plant growth regulators for efficient chloroplast transformation.
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Affiliation(s)
| | | | | | - Henry Daniell
- Department of Molecular Biology and Microbiology, College of Medicine, University of Central Florida, Orlando, Florida 32816–2364
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19
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Courtois F, Merendino L, Demarsy E, Mache R, Lerbs-Mache S. Phage-type RNA polymerase RPOTmp transcribes the rrn operon from the PC promoter at early developmental stages in Arabidopsis. PLANT PHYSIOLOGY 2007; 145:712-21. [PMID: 17885088 PMCID: PMC2048797 DOI: 10.1104/pp.107.103846] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Accepted: 09/07/2007] [Indexed: 05/17/2023]
Abstract
The plastid genome of higher plants is transcribed by two different types of RNA polymerases named nucleus encoded RNA polymerase (NEP) and plastid encoded RNA polymerase. Plastid encoded RNA polymerase is a multimeric enzyme comparable to eubacterial RNA polymerases. NEP enzymes represent a small family of monomeric phage-type RNA polymerases. Dicotyledonous plants harbor three different phage-type enzymes, named RPOTm, RPOTp, and RPOTmp. RPOTm is exclusively targeted to mitochondria, RPOTp is exclusively targeted to plastids, and RPOTmp is targeted to plastids as well as to mitochondria. In this article, we have made use of RPOTp and RPOTmp T-DNA insertion mutants to answer the question of whether both plastid-located phage-type RNA polymerases have overlapping or specific functions in plastid transcription. To this aim, we have analyzed accD and rpoB messenger RNAs (mRNA; transcribed from type I NEP promoters), clpP mRNA (transcribed from the -59 type II NEP promoter), and the 16S rRNA (transcribed from the exceptional PC NEP promoter) by primer extension. Results suggest that RPOTp represents the principal RNA polymerase for transcribing NEP-controlled mRNA genes during early plant development, while RPOTmp transcribes specifically the rrn operon from the PC promoter during seed imbibition.
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Affiliation(s)
- Florence Courtois
- Laboratoire Plastes et Differenciation Cellulaire, Université Joseph Fourier and Centre National de la Recherche Scientifique, B.P. 53, F-38041 Grenoble, France
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20
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Swiatecka-Hagenbruch M, Liere K, Börner T. High diversity of plastidial promoters in Arabidopsis thaliana. Mol Genet Genomics 2007; 277:725-34. [PMID: 17333279 DOI: 10.1007/s00438-007-0222-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Accepted: 02/08/2007] [Indexed: 10/23/2022]
Abstract
Arabidopsis thaliana is well established as a model plant in modern plant biology. However, remarkably few details are known about plastidial promoters in Arabidopsis. Here, we report on the identification and analyses of sequences at transcription start sites of selected genes. The genes encoded by the plastome of higher plants are transcribed by a plastid-encoded (PEP) and a nuclear-encoded RNA plastid polymerase (NEP). To discriminate between NEP and PEP promoters we compared the 5'-ends of transcripts from chlorophyll-deficient Arabidopsis plants, which were grown on prokaryotic translation inhibitor spectinomycin to inhibit biosynthesis of PEP, with those of untreated plants. Using 5'-RACE combined with enzymatic treatment of RNAs to recognize primary and secondary 5'-ends, we unambiguously identified transcription initiation sites of the Arabidopsis accD, atpB, atpI, rpoB, rps4, rps15, and ycf1 genes. Comparison of plastidial promoters from tobacco and Arabidopsis revealed a high diversity, which may also apply to other plants. Furthermore, the diversity in individual promoter usage in different plants suggests that there are species-specific solutions for attaining control over gene expression in plastids.
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21
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Khan MS, Hameed W, Nozoe M, Shiina T. Disruption of the psbA gene by the copy correction mechanism reveals that the expression of plastid-encoded genes is regulated by photosynthesis activity. JOURNAL OF PLANT RESEARCH 2007; 120:421-30. [PMID: 17427034 DOI: 10.1007/s10265-007-0082-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Accepted: 02/02/2007] [Indexed: 05/07/2023]
Abstract
The functional analysis of genes encoded by the chloroplast genome of tobacco by reverse genetics is routine. Nevertheless, for a small number of genes their deletion generates heteroplasmic genotypes, complicating their analysis. There is thus the need for additional strategies to develop deletion mutants for these genes. We have developed a homologous copy correction-based strategy for deleting/mutating genes encoded on the chloroplast genome. This system was used to produce psbA knockouts. The resulting plants are homoplasmic and lack photosystem II (PSII) activity. Further, the deletion mutants exhibit a distinct phenotype; young leaves are green, whereas older leaves are bleached, irrespective of light conditions. This suggests that senescence is promoted by the absence of psbA. Analysis of the transcript levels indicates that NEP (nuclear-encoded plastid RNA polymerase)-dependent plastid genes are up regulated in the psbA deletion mutants, whereas the bleached leaves retain plastid-encoded plastid RNA polymerase activity. Hence, the expression of NEP-dependent plastid genes may be regulated by photosynthesis, either directly or indirectly.
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Affiliation(s)
- Muhammad Sarwar Khan
- National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan.
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22
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Zoschke R, Liere K, Börner T. From seedling to mature plant: arabidopsis plastidial genome copy number, RNA accumulation and transcription are differentially regulated during leaf development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2007; 50:710-22. [PMID: 17425718 DOI: 10.1111/j.1365-313x.2007.03084.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Little is known about DNA and RNA metabolism during leaf development and aging in the model organism Arabidopsis. Therefore we examined the nuclear and plastidial DNA content of tissue ranging in age from 2-day-old cotyledons to 37-day-old senescent rosette leaves. Flow-cytometric analysis showed an increase in nuclear DNA ploidy levels of up to 128 genome copies per nucleus in older leaves. The copy numbers of nuclear 18S-rRNA genes were determined to be 700 +/- 60 per haploid genome. Adjusted to the average level of nuclear DNA polyploidism per cell, plastome copy numbers varied from about 1000 to 1700 per cell without significant variation during development from young to old rosette leaves. The transcription activity of all studied plastid genes was significantly reduced in older rosette leaves in comparison to that in young leaves. In contrast, levels of plastidial transcript accumulation showed different patterns. In the case of psbA, transcripts accumulated to even higher levels in older leaves, indicating that differential regulation of plastidial gene expression occurs during leaf development. Examination of promoter activity from clpP and rrn16 genes by primer extension analyses revealed that two RNA polymerases (NEP and PEP) transcribe these genes in cotyledons as well as in young and senescent leaves. However, PEP may have a more prominent role in older rosette leaves than in young cotyledons. We conclude that in cotyledons or leaves of different ages plastidial gene expression is regulated at the transcriptional and post-transcriptional levels, but not by plastome copy number.
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Affiliation(s)
- Reimo Zoschke
- Institut für Biologie/Genetik, Humboldt-Universität zu Berlin, Chausseestr. 117, D-10115 Berlin, Germany
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23
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Transcription and transcriptional regulation in plastids. CELL AND MOLECULAR BIOLOGY OF PLASTIDS 2007. [DOI: 10.1007/4735_2007_0232] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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24
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Kanamoto H, Yamashita A, Asao H, Okumura S, Takase H, Hattori M, Yokota A, Tomizawa KI. Efficient and stable transformation of Lactuca sativa L. cv. Cisco (lettuce) plastids. Transgenic Res 2006; 15:205-17. [PMID: 16604461 DOI: 10.1007/s11248-005-3997-2] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Accepted: 10/05/2005] [Indexed: 10/24/2022]
Abstract
Transgenic plastids offer unique advantages in plant biotechnology, including high-level foreign protein expression. However, broad application of plastid genome engineering in biotechnology has been largely hampered by the lack of plastid transformation systems for major crops. Here we describe the development of a plastid transformation system for lettuce, Lactuca sativa L. cv. Cisco. The transforming DNA carries a spectinomycin-resistance gene (aadA) under the control of lettuce chloroplast regulatory expression elements, flanked by two adjacent lettuce plastid genome sequences allowing its targeted insertion between the rbcL and accD genes. On average, we obtained 1 transplastomic lettuce plant per bombardment. We show that lettuce leaf chloroplasts can express transgene-encoded GFP to approximately 36% of the total soluble protein. All transplastomic T0 plants were fertile and the T1 progeny uniformly showed stability of the transgene in the chloroplast genome. This system will open up new possibilities for the efficient production of edible vaccines, pharmaceuticals, and antibodies in plants.
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Affiliation(s)
- Hirosuke Kanamoto
- Resarch Institute of Innovative Technology for the Earth, Kizu-cho Soraku-gun, Kyoto, Japan.
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25
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Lelivelt CLC, McCabe MS, Newell CA, deSnoo CB, van Dun KMP, Birch-Machin I, Gray JC, Mills KHG, Nugent JM. Stable plastid transformation in lettuce (Lactuca sativa L.). PLANT MOLECULAR BIOLOGY 2005; 58:763-774. [PMID: 16240172 DOI: 10.1007/s11103-005-7704-8] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2005] [Accepted: 05/20/2005] [Indexed: 05/04/2023]
Abstract
Although plastid transformation in higher plants was first demonstrated in the early 1990s it is only recently that the technology is being extended to a broader range of species. To date, the production of fertile transplastomic plants has been reported for tobacco, tomato, petunia, soybean, cotton and Lesquerella fendleri (Brassicaceae). In this study we demonstrate a polyethylene glycol-mediated plastid transformation system for lettuce that generates fertile, homoplasmic, plastid-transformed lines. Transformation was achieved using a vector that targets genes to the trnA/trnI intergenic region of the lettuce plastid genome employing the aadA gene as a selectable marker against spectinomycin. Spectinomycin resistance and heterologous gene transcription were shown in T(1) plants derived from self-pollinated primary regenerants demonstrating transmission of the plastid-encoded transgene to the first seed generation. Crossing with male sterile wild-type lettuce showed that spectinomycin resistance was not transmitted via pollen. Constructs containing the gfp gene showed plastid-based expression of green fluorescent protein. The lettuce plastid could have potential both as a production and a delivery system for edible human therapeutic proteins.
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Affiliation(s)
- Cilia L C Lelivelt
- Rijk Zwaan Breeding B.V., 1e Kruisweg 9, 4793 RS, Fijnaart, The Netherlands
| | - Matthew S McCabe
- Institute of Bioengineering and Agroecology, National University of Ireland, Maynooth, Co. Kildare, Ireland
| | - Christine A Newell
- Department of Plant Sciences, University of Cambridge, Downing Street, CB2 3EA, Cambridge, UK
| | - C Bastiaan deSnoo
- Rijk Zwaan Breeding B.V., 1e Kruisweg 9, 4793 RS, Fijnaart, The Netherlands
| | - Kees M P van Dun
- Rijk Zwaan Breeding B.V., 1e Kruisweg 9, 4793 RS, Fijnaart, The Netherlands
| | - Ian Birch-Machin
- Department of Plant Sciences, University of Cambridge, Downing Street, CB2 3EA, Cambridge, UK
- Department of Anatomy, University of Cambridge, Downing Street, CB2 3DY, Cambridge, UK
| | - John C Gray
- Department of Plant Sciences, University of Cambridge, Downing Street, CB2 3EA, Cambridge, UK
| | | | - Jacqueline M Nugent
- Institute of Bioengineering and Agroecology, National University of Ireland, Maynooth, Co. Kildare, Ireland.
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26
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Ishizaki Y, Tsunoyama Y, Hatano K, Ando K, Kato K, Shinmyo A, Kobori M, Takeba G, Nakahira Y, Shiina T. A nuclear-encoded sigma factor, Arabidopsis SIG6, recognizes sigma-70 type chloroplast promoters and regulates early chloroplast development in cotyledons. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2005; 42:133-44. [PMID: 15807777 DOI: 10.1111/j.1365-313x.2005.02362.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Eubacterial-type multi-subunit plastid RNA polymerase (PEP) is responsible for the principal transcription activity in chloroplasts. PEP is composed of plastid-encoded core subunits and one of multiple nuclear-encoded sigma factors that confer promoter specificity on PEP. Thus, the replacement of sigma factors associated with PEP has been assumed to be a major mechanism for the switching of transcription patterns during chloroplast development. The null mutant (sig6-1) of plastid sigma factor gene AtSIG6 exhibited a cotyledon-specific pale green phenotype. Light-dependent chloroplast development was significantly delayed in the sig6-1 mutant. Genetic complementation of the mutant phenotype by the AtSIG6 cDNA demonstrated that AtSIG6 plays a key role in light-dependent chloroplast development. Northern and array-based global analyses for plastid transcripts revealed that the transcript levels of most PEP-dependent genes were greatly reduced in the sig6-1 mutant, but that the accumulation of nuclear-encoded RNA polymerase (NEP)-dependent transcripts generally increased. As the PEP alpha subunit and PEP-dependent trnV accumulated at normal levels in the sig6-1 mutant, the AtSIG6 knockout mutant probably retained functional PEP, and the transcriptional defects are likely to have been directly caused by AtSIG6 deficiency. Most of the AtSIG6-dependent genes are preceded by sigma70-type promoters comprised of conserved -35/-10 elements. Thus, AtSIG6 may act as a major general sigma factor in chloroplasts during early plant development. On the other hand, the mutant phenotype was restored in older seedlings. Arabidopsis probably contains another late general sigma factor, the promoter specificity of which widely overlaps with that of AtSIG6.
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Affiliation(s)
- Yoko Ishizaki
- Faculty of Human Environment, Kyoto Prefectural University, Shimogamo-nakaragi-cho, Sakyo-ku, Kyoto 606-8522, Japan
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27
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Shiina T, Tsunoyama Y, Nakahira Y, Khan MS. Plastid RNA polymerases, promoters, and transcription regulators in higher plants. INTERNATIONAL REVIEW OF CYTOLOGY 2005; 244:1-68. [PMID: 16157177 DOI: 10.1016/s0074-7696(05)44001-2] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Plastids are semiautonomous plant organelles exhibiting their own transcription-translation systems that originated from a cyanobacteria-related endosymbiotic prokaryote. As a consequence of massive gene transfer to nuclei and gene disappearance during evolution, the extant plastid genome is a small circular DNA encoding only ca. 120 genes (less than 5% of cyanobacterial genes). Therefore, it was assumed that plastids have a simple transcription-regulatory system. Later, however, it was revealed that plastid transcription is a multistep gene regulation system and plays a crucial role in developmental and environmental regulation of plastid gene expression. Recent molecular and genetic approaches have identified several new players involved in transcriptional regulation in plastids, such as multiple RNA polymerases, plastid sigma factors, transcription regulators, nucleoid proteins, and various signaling factors. They have provided novel insights into the molecular basis of plastid transcription in higher plants. This review summarizes state-of-the-art knowledge of molecular mechanisms that regulate plastid transcription in higher plants.
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Affiliation(s)
- Takashi Shiina
- Faculty of Human Environment, Kyoto Prefectural University, Kyoto 606-8522, Japan
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28
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Emanuel C, Weihe A, Graner A, Hess WR, Börner T. Chloroplast development affects expression of phage-type RNA polymerases in barley leaves. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2004; 38:460-72. [PMID: 15086795 DOI: 10.1111/j.0960-7412.2004.02060.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We have identified the barley gene and cDNA encoding the plastid phage-type RNA polymerase (RNAP), nuclear-encoded plastid RNAP (RpoTp), and the nearly full-length cDNA of the mitochondrial RNAP, nuclear-encoded mitochondrial RNAP (RpoTm). RpoTp spans more than 9000 nt, consists of 19 exons and 18 introns, gives rise to a 3632-nt mRNA and is localized to the long arm of chromosome 1 (7H). The length of the deduced polypeptide is 948 residues. The mRNA levels of RpoTp and RpoTm were determined in roots and primary leaf sections of 7-day-old barley seedlings of the albostrians mutant, which were either phenotypically normal and exhibited a gradient of chloroplast development, or contained ribosome-deficient undifferentiated plastids. Transcript levels of RpoTp and RpoTm in almost all sections reached higher concentrations in plastid ribosome-deficient leaves than in the wild-type material, except in the most basal part of the leaf. These data indicate a role of plastid-to-nucleus signalling in the expression of the two RpoT genes. The mRNA levels of the plastid genes, beta-subunit of plastid-encoded RNAP (rpoB), proteolytic subunit of the Clp protease (clpP) and ribosomal protein Rpl2 (rpl2), all known to be transcribed by the nuclear-encoded RNAP (NEP), followed closely the pattern of RpoTp mRNA accumulation, strongly suggesting that RpoTp and NEP are identical. Transcripts of RpoTm and RpoTm-transcribed mitochondrial genes cytochrome oxidase subunit 2 (coxII) and ATPase subunit 9 (atp9) accumulated to the highest levels in the most basal parts of the leaf and declined considerably towards the leaf tip with a pronounced reduction in green versus white leaves. Our data revealed a marked influence of the developmental stage of the plastid on the expression and activity of organellar phage-type RNAPs and their target genes. Thus, interorganellar cross-talk in the regulated expression of nuclear-encoded plastid and mitochondrial RNAP genes might be a key element governing the concerted expression of genes located within plastids, mitochondria and the nucleus of the plant cell.
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MESH Headings
- Amino Acid Sequence
- Chloroplasts/enzymology
- Chloroplasts/genetics
- Chloroplasts/physiology
- Cloning, Molecular
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA, Plant/chemistry
- DNA, Plant/genetics
- DNA-Directed RNA Polymerases/genetics
- DNA-Directed RNA Polymerases/metabolism
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Hordeum/enzymology
- Hordeum/genetics
- Hordeum/growth & development
- Mitochondria/enzymology
- Mitochondria/genetics
- Molecular Sequence Data
- Phylogeny
- Plant Leaves/enzymology
- Plant Leaves/genetics
- Plant Leaves/growth & development
- Plant Proteins/genetics
- Plant Proteins/metabolism
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Transcription Factors/genetics
- Transcription Factors/metabolism
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Affiliation(s)
- Carola Emanuel
- Humboldt-University, Department of Biology/Genetics, Chausseestr. 117, D-10115 Berlin, Germany
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Liere K, Kaden D, Maliga P, Börner T. Overexpression of phage-type RNA polymerase RpoTp in tobacco demonstrates its role in chloroplast transcription by recognizing a distinct promoter type. Nucleic Acids Res 2004; 32:1159-65. [PMID: 14973224 PMCID: PMC373414 DOI: 10.1093/nar/gkh285] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2003] [Revised: 12/29/2003] [Accepted: 01/26/2004] [Indexed: 11/14/2022] Open
Abstract
Plant cells possess three DNA-containing compartments, the nucleus, the mitochondria and the plastids. Accordingly, plastid gene regulation is fairly complex. Albeit plastids retained their own genome and prokaryotic-type gene expression system by a plastid-encoded RNA polymerase (PEP), they need a second nuclear-encoded plastid transcription activity, NEP. Candidate genes for putative NEP catalytic subunits have been cloned in Arabidopsis thaliana (AtRpoTp) and Nicotiana sylvestris (NsRpoTp). To provide evidence for RpoTp as a gene encoding a NEP catalytic subunit, we introduced the AtRpoTp and NsRpoTp cDNAs into the tobacco nucleus under the control of the strong constitutive CaMV 35S promoter. Analysis of transcription from NEP and PEP promoters in these transgenic plants using primer extension assays revealed enhanced transcription from typical type I NEP promoters as PatpB-289 in comparison with the wild type. These data provide direct evidence that RpoTp is a catalytic subunit of NEP and involved in recognition of a distinct subset of type I NEP promoters.
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Affiliation(s)
- Karsten Liere
- Institute of Biology (Genetics), Humboldt University Berlin, Chausseestrasse 117, D-10115 Berlin, Germany
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Bisanz C, Bégot L, Carol P, Perez P, Bligny M, Pesey H, Gallois JL, Lerbs-Mache S, Mache R. The Arabidopsis nuclear DAL gene encodes a chloroplast protein which is required for the maturation of the plastid ribosomal RNAs and is essential for chloroplast differentiation. PLANT MOLECULAR BIOLOGY 2003; 51:651-63. [PMID: 12678554 DOI: 10.1023/a:1022557825768] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Altered pigmentation is an easily scored and sensitive monitor of plastid function. We analyzed in detail a yellow colored transposon-tagged mutant (dal1-2) that is allelic to the dal mutant previously identified (Babiychuk et al., 1997). Mesophyll cells of mutant plants possess abnormal nucleoids and more but smaller plastids than wild type cells. Plastid development in dal1-2 is not altered in the dark but is arrested at the early steps of thylakoid assembly. The amino acid sequence of the protein deduced from our cDNA clone is 21 amino acids longer than the previously published DAL sequence (Babiychuk et al., 1997) and allowed us to show that DAL codes for a chloroplast protein. The dal1-2 mutation has a global negative effect on plastid RNA accumulation and on expression of nuclear encoded photosynthetic genes. We show that the plastid RNA polymerases, the nuclear-encoded NEP and the plastid-encoded PEP, are functional in the mutant. Precursor 16S and 23S rRNA species specifically accumulate at a high level in the mutant but the 5'-end and the long 3'-end trailer are not modified. We suggest that the dal mutation is involved in plastid rRNA processing and consequently in translation and early chloroplast differentiation.
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Affiliation(s)
- Cordelia Bisanz
- Laboratoire Plastes et Differenciation cellulaire, Université Joseph Fourier et Centre National de la Recherche Scientifique (CNRS), UMR 5575, BP53, 38041 Grenoble cedex 9, France
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31
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Skarjinskaia M, Svab Z, Maliga P. Plastid transformation in Lesquerella fendleri, an oilseed Brassicacea. Transgenic Res 2003; 12:115-22. [PMID: 12650530 DOI: 10.1023/a:1022110402302] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A plastid transformation protocol was developed for Lesquerella fendleri, a species with a high capacity for plant regeneration in tissue culture. Transformation vector pZS391B carried an aadA16gfp marker gene conferring streptomycin-spectinomycin resistance and green fluorescence under UV light. Biolistic transformation of 51 Lesquerella leaf samples, followed by spectinomycin selection, yielded two transplastomic clones. The AAD-GFP fusion protein, the marker gene product, was localized to chloroplasts by confocal laser microscopy. Fertile plants and seed progeny were obtained in line Lf-pZS391B-1. In the 51 samples a large number (108) of spontaneous mutants were identified. In five of the lines spectinomycin resistance was localized to a conserved stem structure by sequencing 16S rRNA genes. Success in L. fendleri, a wild oilseed species, extends plastid transformation beyond Arabidopsis thaliana in the Brassicaceae family.
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Affiliation(s)
- Marina Skarjinskaia
- Waksman Institute, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, NJ 08854-8020, USA
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Suzuki JY, Sriraman P, Svab Z, Maliga P. Unique architecture of the plastid ribosomal RNA operon promoter recognized by the multisubunit RNA polymerase in tobacco and other higher plants. THE PLANT CELL 2003; 15:195-205. [PMID: 12509531 PMCID: PMC143491 DOI: 10.1105/tpc.007914] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2002] [Accepted: 10/24/2002] [Indexed: 05/20/2023]
Abstract
Expression of the plastid rRNA operon (rrn) during development is highly regulated at the level of transcription. The plastid rrn operon in most higher plants is transcribed by the plastid-encoded RNA polymerase (PEP), the multisubunit plastid RNA polymerase from PrrnP1, a sigma(70)-type promoter with conserved -10 and -35 core promoter elements. To identify functionally important sequences, the tobacco PrrnP1 was dissected in vivo and in vitro. Based on in vivo deletion analysis, sequences upstream of nucleotide -83 do not significantly contribute to promoter function. The in vitro analyses identified an essential hexameric sequence upstream of the -35 element (GTGGGA; the rRNA operon upstream activator [RUA]) that is conserved in monocot and dicot species and suggested that the -10 element plays only a limited role in PrrnP1 recognition. Mutations in the initial transcribed sequence (+9 to +14) enhanced transcription, the characteristic of strong promoters in prokaryotes. We propose that sigma interaction with the -10 element in PrrnP1 is replaced in part by direct PEP-RUA (protein-DNA) interaction or by protein-protein interaction between the PEP and an RUA binding transcription factor.
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Affiliation(s)
- Jon Y Suzuki
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8020, USA
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Schmitz-Linneweber C, Regel R, Du TG, Hupfer H, Herrmann RG, Maier RM. The plastid chromosome of Atropa belladonna and its comparison with that of Nicotiana tabacum: the role of RNA editing in generating divergence in the process of plant speciation. Mol Biol Evol 2002; 19:1602-12. [PMID: 12200487 DOI: 10.1093/oxfordjournals.molbev.a004222] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The nuclear and plastid genomes of the plant cell form a coevolving unit which in interspecific combinations can lead to genetic incompatibility of compartments even between closely related taxa. This phenomenon has been observed for instance in Atropa-Nicotiana cybrids. We have sequenced the plastid chromosome of Atropa belladonna (deadly nightshade), a circular DNA molecule of 156,688 bp, and compared it with the corresponding published sequence of its relative Nicotiana tabacum (tobacco) to understand how divergence at the level of this genome can contribute to nuclear-plastid incompatibilities and to speciation. It appears that (1) regulatory elements, i.e., promoters as well as translational and replicational signal elements, are well conserved between the two species; (2) genes--including introns--are even more highly conserved, with differences residing predominantly in regions of low functional importance; and (3) RNA editotypes differ between the two species, which makes this process an intriguing candidate for causing rapid reproductive isolation of populations.
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Kuroda H, Maliga P. Overexpression of the clpP 5'-untranslated region in a chimeric context causes a mutant phenotype, suggesting competition for a clpP-specific RNA maturation factor in tobacco chloroplasts. PLANT PHYSIOLOGY 2002; 129:1600-6. [PMID: 12177472 PMCID: PMC166747 DOI: 10.1104/pp.004986] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2002] [Revised: 03/27/2002] [Accepted: 04/18/2002] [Indexed: 05/21/2023]
Abstract
The plastid ribosomal RNA (rrn) operon promoter was fused with DNA segments encoding the leader sequence (5'-untranslated region [UTR]) of plastid mRNAs to compare their efficiency in mediating translation of a bacterial protein neomycin phosphotransferase (NPTII) in tobacco (Nicotiana tabacum) chloroplasts. In young leaves, NPTII accumulated at 0.26% and 0.8% of the total soluble leaf protein from genes with the clpP and atpB 5'-UTR, respectively. Interestingly, expression of NPTII from the promoter with the clpP 5'-UTR (0.26% NPTII) caused a mutant (chlorotic) phenotype, whereas plants accumulating approximately 0.8% NPTII from the atpB 5'-UTR were normal green, indicating that the mutant phenotype was independent of NPTII accumulation. Low levels of monocistronic clpP mRNA and accumulation of intron-containing clpP transcripts in the chlorotic leaves suggest competition between the clpP 5'-UTR in the chimeric transcript and the native clpP pre-mRNA (ratio 16:1) for an mRNA maturation factor. Because maturation of 11 other intron-containing mRNAs was unaffected in the chlorotic leaves, it appears that the factor is clpP specific. The mutant phenotype is correlated with reduced levels (approximately 2 times) of the ClpP1 protease subunit, supporting an important role for ClpP1 in chloroplast development.
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Affiliation(s)
- Hiroshi Kuroda
- Waksman Institute, 190 Frelinghuysen Road, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8020, USA
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Abstract
Transformation of the plastid genome has a number of inherent advantages for the engineering of gene expression in plants. These advantages include: 10-50 times higher transgene expression levels; the absence of gene silencing and position effect variation; the ability to express polycistronic messages from a single promoter; uniparental plastid gene inheritance in most crop plants that prevents pollen transmission of foreign DNA; integration via a homologous recombination process that facilitates targeted gene replacement and precise transgene control; and sequestration of foreign proteins in the organelle which prevents adverse interactions with the cytoplasmic environment. It is now 12 years since the first conclusive demonstration of stable introduction of cloned DNA into the Chlamydomonas chloroplast by the Boynton and Gillham laboratory, and 10 years since the laboratory of Pal Maliga successfully extended these approaches to tobacco. Since then, technical developments in plastid transformation and advances in our understanding of the rules of plastid gene expression have facilitated tremendous progress towards the goal of establishing the chloroplast as a feasible platform for genetic modification of plants.
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Affiliation(s)
- P B Heifetz
- Novartis Agribusiness Biotechnology Research, Inc., 3054 Cornwallis Road, Research Triangle Park, NC 27709-2257, USA.
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Bligny M, Courtois F, Thaminy S, Chang CC, Lagrange T, Baruah-Wolff J, Stern D, Lerbs-Mache S. Regulation of plastid rDNA transcription by interaction of CDF2 with two different RNA polymerases. EMBO J 2000; 19:1851-60. [PMID: 10775269 PMCID: PMC302015 DOI: 10.1093/emboj/19.8.1851] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The plastid genome is known to be transcribed by a plastid-encoded prokaryotic-type RNA polymerase (PEP) and by a nucleus-encoded phage-type RNA polymerase (NEP). The spinach plastid rrn operon promoter region harbours three different, overlapping promoters. Two of them are of the prokaryotic type. The third promoter is a non-consensus-type NEP promoter. We separated three different transcriptional activities from spinach chloroplasts: PEP, the phage-type RNA polymerase NEP-1, and a third, hitherto undescribed transcriptional activity (NEP-2). NEP-2 specifically transcribes the rrn operon in the presence of the transcription factor CDF2. CDF2 was previously shown to recruit PEP to the rrn promoter to repress transcription. Together, our results suggest the existence of a third RNA polymerase in plastids and a mechanism of rDNA transcriptional regulation that is based on the interaction of the transcription factor CDF2 with two different transcriptional systems.
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Affiliation(s)
- M Bligny
- Laboratoire de Génétique Moléculaire des Plantes, Université Joseph Fourier and Centre National de la Recherche Scientifique, BP 53X, F-38041 Grenoble, France
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Bock R, Hagemann R. Extranuclear Inheritance: Plastid Genetics: Manipulation of Plastid Genomes and Biotechnological Applications. PROGRESS IN BOTANY 2000. [DOI: 10.1007/978-3-642-57203-6_4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Sidorov VA, Kasten D, Pang SZ, Hajdukiewicz PT, Staub JM, Nehra NS. Technical Advance: Stable chloroplast transformation in potato: use of green fluorescent protein as a plastid marker. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 1999; 19:209-216. [PMID: 10476068 DOI: 10.1046/j.1365-313x.1999.00508.x] [Citation(s) in RCA: 185] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We describe here the development of a reproducible plastid transformation system for potato and regeneration of plants with uniformly transformed plastids. Two distinct tobacco-specific plastid vectors, pZS197 (Prrn/aadA/TpsbA) and pMON30125 (Prrn/GFP/Trps16:PpsbA/aadA/TpsbA), designed for integration into the large single copy and inverted repeat regions of the plastid genome, respectively, were bombarded into leaf explants of potato line FL1607. A total of three transgenic lines were selected out of 46 plates bombarded with pZS197 and three transgenic lines out of 104 plates were obtained with pMON30125. Development of a high frequency leaf-based regenera- tion system, a stringent selection scheme and optimization of biolistic transformation protocol were critical for recovery of plastid transformants. Plastid-expressed green fluorescent protein was used as a visual marker for identification of plastid transformants at the early stage of selection and shoot regeneration. The establishment of a plastid transformation system in potato, which has several advantages over routinely used nuclear transformation, offers new possibilities for genetic improvement of this crop.
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Abstract
The nuclear genome of the model plant Arabidopsis thaliana contains a small gene family consisting of three genes encoding RNA polymerases of the single-subunit bacteriophage type. There is evidence that similar gene families also exist in other plants. Two of these RNA polymerases are putative mitochondrial enzymes, whereas the third one may represent the nuclear-encoded RNA polymerase (NEP) active in plastids. In addition, plastid genes are transcribed from another, entirely different multisubunit eubacterial-type RNA polymerase, the core subunits of which are encoded by plastid genes [plastid-encoded RNA polymerase (PEP)]. This core enzyme is complemented by one of several nuclear-encoded sigma-like factors. The development of photosynthetically active chloroplasts requires both PEP and NEP. Most NEP promoters show certain similarities to mitochondrial promoters in that they include the sequence motif 5'-YRTA-3' near the transcription initiation site. PEP promoters are similar to bacterial promoters of the -10/-35 sigma 70 type.
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Affiliation(s)
- W R Hess
- Institute of Biology, Humboldt University, Berlin, Germany
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