1
|
Chung KP, Gonzalez-Duran E, Ruf S, Endries P, Bock R. Control of plastid inheritance by environmental and genetic factors. NATURE PLANTS 2023; 9:68-80. [PMID: 36646831 PMCID: PMC9873568 DOI: 10.1038/s41477-022-01323-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 11/26/2022] [Indexed: 06/01/2023]
Abstract
The genomes of cytoplasmic organelles (mitochondria and plastids) are maternally inherited in most eukaryotes, thus excluding organellar genomes from the benefits of sexual reproduction and recombination. The mechanisms underlying maternal inheritance are largely unknown. Here we demonstrate that two independently acting mechanisms ensure maternal inheritance of the plastid (chloroplast) genome. Conducting large-scale genetic screens for paternal plastid transmission, we discovered that mild chilling stress during male gametogenesis leads to increased entry of paternal plastids into sperm cells and strongly increased paternal plastid transmission. We further show that the inheritance of paternal plastid genomes is controlled by the activity of a genome-degrading exonuclease during pollen maturation. Our data reveal that (1) maternal inheritance breaks down under specific environmental conditions, (2) an organelle exclusion mechanism and a genome degradation mechanism act in concert to prevent paternal transmission of plastid genes and (3) plastid inheritance is determined by complex gene-environment interactions.
Collapse
Affiliation(s)
- Kin Pan Chung
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | | | - Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Pierre Endries
- Universität Hamburg, Institut für Pflanzenwissenschaften und Mikrobiologie, Hamburg, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany.
| |
Collapse
|
2
|
Robles P, Quesada V. Unveiling the functions of plastid ribosomal proteins in plant development and abiotic stress tolerance. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2022; 189:35-45. [PMID: 36041366 DOI: 10.1016/j.plaphy.2022.07.029] [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: 05/16/2022] [Revised: 07/22/2022] [Accepted: 07/24/2022] [Indexed: 06/15/2023]
Abstract
Translation of mRNAs into proteins is a universal process and ribosomes are the molecular machinery that carries it out. In eukaryotic cells, ribosomes can be found in the cytoplasm, mitochondria, and also in the chloroplasts of photosynthetic organisms. A number of genetic studies have been performed to determine the function of plastid ribosomal proteins (PRPs). Tobacco has been frequently used as a system to study the ribosomal proteins encoded by the chloroplast genome. In contrast, Arabidopsis thaliana and rice are preferentially used models to study the function of nuclear-encoded PRPs by using direct or reverse genetics approaches. The results of these works have provided a relatively comprehensive catalogue of the roles of PRPs in different plant biology aspects, which highlight that some PRPs are essential, while others are not. The latter ones are involved in chloroplast biogenesis, lateral root formation, leaf morphogenesis, plant growth, photosynthesis or chlorophyll synthesis. Furthermore, small gene families encode some PRPs. In the last few years, an increasing number of findings have revealed a close association between PRPs and tolerance to adverse environmental conditions. Sometimes, the same PRP can be involved in both developmental processes and the response to abiotic stress. The aim of this review is to compile and update the findings hitherto published on the functional analysis of PRPs. The study of the phenotypic effects caused by the disruption of PRPs from different species reveals the involvement of PRPs in different biological processes and highlights the significant impact of plastid translation on plant biology.
Collapse
Affiliation(s)
- Pedro Robles
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202, Elche, Spain
| | - Víctor Quesada
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202, Elche, Spain.
| |
Collapse
|
3
|
Chen S, Zeng X, Li Y, Qiu S, Peng X, Xie X, Liu Y, Liao C, Tang X, Wu J. The nuclear-encoded plastid ribosomal protein L18s are essential for plant development. FRONTIERS IN PLANT SCIENCE 2022; 13:949897. [PMID: 36212366 PMCID: PMC9538462 DOI: 10.3389/fpls.2022.949897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 08/29/2022] [Indexed: 06/16/2023]
Abstract
Plastid ribosomal proteins (PRPs) are necessary components for plastid ribosome biogenesis, playing essential roles in plastid development. The ribosomal protein L18 involved in the assemble of 5S rRNA and 23S rRNA, is vital for E. coli viability, but the functions of its homologs in plant plastid remain elusive. Here, we characterized the functions of the plant plastid ribosomal protein L18s (PRPL18s) in Arabidopsis and rice. AtPRPL18 was ubiquitously expressed in most of the plant tissues, but with higher expression levels in seedling shoots, leaves, and flowers. AtPRPL18 was localized in chloroplast. Genetic and cytological analyses revealed that a loss of function of AtPRPL18 resulted in embryo development arrest at globular stage. However, overexpression of AtPRPL18 did not show any visible phenotypical changes in Arabidopsis. The rice OsPRPL18 was localized in chloroplast. In contrast to AtPRPL18, knockout of OsPRPL18 did not affect embryo development, but led to an albino lethal phenotype at the seedling stage. Cytological analyses showed that chloroplast development was impaired in the osprpl18-1 mutant. Moreover, a loss-function of OsPRPL18 led to defects in plastid ribosome biogenesis and a serious reduction in the efficiency of plastid intron splicing. In all, these results suggested that PRPL18s play critical roles in plastid ribosome biogenesis, plastid intron splicing, and chloroplast development, and are essential for plant survival.
Collapse
Affiliation(s)
- Shujing Chen
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Xinhuang Zeng
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Yiqi Li
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Shijun Qiu
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Xiaoqun Peng
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Xinjue Xie
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Yujie Liu
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Chancan Liao
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Xiaoyan Tang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong, China
- Shenzhen Institute of Molecular Crop Design, Shenzhen, China
| | - Jianxin Wu
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| |
Collapse
|
4
|
Sukhoverkov KV, Breese KJ, Debowski AW, Murcha MW, Stubbs KA, Mylne JS. Inhibition of chloroplast translation as a new target for herbicides. RSC Chem Biol 2022; 3:37-43. [PMID: 35128407 PMCID: PMC8729176 DOI: 10.1039/d1cb00192b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 11/10/2021] [Indexed: 12/21/2022] Open
Abstract
The rise in herbicide resistance over recent decades threatens global agriculture and food security and so discovery of new modes of action is increasingly important. Here we reveal linezolid, an oxazolidinone antibiotic that inhibits microbial translation, is also herbicidal. To validate the herbicidal mode of action of linezolid we confirmed its micromolar inhibition is specific to chloroplast translation and did not affect photosynthesis directly. To assess the herbicide potential of linezolid, testing against a range of weed and crop species found it effective pre- and post-emergence. Using structure-activity analysis we identified the critical elements for herbicidal activity, but importantly also show, using antimicrobial susceptibility assays, that separation of antibacterial and herbicidal activities was possible. Overall these results validate chloroplast translation as a viable herbicidal target.
Collapse
Affiliation(s)
- Kirill V Sukhoverkov
- The University of Western Australia, School of Molecular Sciences 35 Stirling Highway Crawley Perth 6009 Australia
- The ARC Centre of Excellence in Plant Energy Biology 35 Stirling Highway Crawley Perth 6009 Australia
| | - Karen J Breese
- The University of Western Australia, School of Molecular Sciences 35 Stirling Highway Crawley Perth 6009 Australia
| | - Aleksandra W Debowski
- The University of Western Australia, School of Molecular Sciences 35 Stirling Highway Crawley Perth 6009 Australia
- School of Biomedical Sciences 35 Stirling Highway Crawley Perth 6009 Australia
| | - Monika W Murcha
- The University of Western Australia, School of Molecular Sciences 35 Stirling Highway Crawley Perth 6009 Australia
- The ARC Centre of Excellence in Plant Energy Biology 35 Stirling Highway Crawley Perth 6009 Australia
| | - Keith A Stubbs
- The University of Western Australia, School of Molecular Sciences 35 Stirling Highway Crawley Perth 6009 Australia
| | - Joshua S Mylne
- The University of Western Australia, School of Molecular Sciences 35 Stirling Highway Crawley Perth 6009 Australia
- The ARC Centre of Excellence in Plant Energy Biology 35 Stirling Highway Crawley Perth 6009 Australia
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University Bentley WA 6102 Australia
| |
Collapse
|
5
|
Yu Z, Zhou T, Li N, Wang D. The complete chloroplast genome and phylogenetic analysis of Corydalis fangshanensis W.T. Wang ex S.Y. He (Papaveraceae). Mitochondrial DNA B Resour 2021; 6:3171-3173. [PMID: 34746395 PMCID: PMC8567948 DOI: 10.1080/23802359.2021.1987172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The complete chloroplast (cp) genome of Corydalis fangshanensis W.T. Wang ex S.Y. He, a Chinese endemic plant with limestone-specific distribution was first reported. The cp genome was circular in structure and 192,554 bp in length, consisting of a large single copy region (LSC, 98,393 bp), two inverted repeat regions (IRs, 42,263 bp), and a small single copy region (SSC, 9,635 bp). The overall GC content of the genome was 40.26%. It encoded 112 unique genes, including 78 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Phylogenetic analysis resolved C. fangshanensis was closely related to C. saxicola G.S. Bunting within Corydalis sect. Thalictrifoliae (Fedde) Lidén, in line with morphological character-based taxonomy. Our result provides informative data for studying the taxonomy, phylogeny and ecology of Corydalis, especially species with specific-limestone distribution and also for studying the adaptive evolution in plants.
Collapse
Affiliation(s)
- Zhiying Yu
- School of Life Sciences, Central China Normal University, Wuhan, Hubei Province, P. R. China
| | - Tianhua Zhou
- Bio-Resources Key Laboratory of Shaanxi Province, School of Life Sciences, Shaanxi University of Technology, Hanzhong, Shaanxi Province, P. R. China
| | - Niya Li
- Wuhan Sinoeco Ecological Science & Technology Co., Ltd., Wuhan, Hubei Province, P. R. China
| | - Dong Wang
- School of Life Sciences, Central China Normal University, Wuhan, Hubei Province, P. R. China.,Bio-Resources Key Laboratory of Shaanxi Province, School of Life Sciences, Shaanxi University of Technology, Hanzhong, Shaanxi Province, P. R. China
| |
Collapse
|
6
|
Marker-Free Transplastomic Plants by Excision of Plastid Marker Genes Using Directly Repeated DNA Sequences. Methods Mol Biol 2021. [PMID: 34028764 DOI: 10.1007/978-1-0716-1472-3_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Excision of marker genes using DNA direct repeats makes use of the efficient native homologous recombination pathway present in the plastids of algae and plants. The method is simple, efficient, and widely applicable to plants and green algae. Marker excision frequency is dependent on the length and number of directly repeated sequences. When two repeats are used a repeat size of greater than 600 bp promotes efficient excision of the marker gene. A wide variety of sequences can be used to make the direct repeats. Only a single round of transformation is required and there is no requirement to introduce site-specific recombinases by retransformation or sexual crosses. Selection is used to maintain the marker and ensure homoplasmy of transgenic plastid genomes (plastomes). Release of selection allows the accumulation of marker-free plastomes generated by marker excision, which is a spontaneous and unidirectional process. Cytoplasmic sorting allows the segregation of cells with marker-free transgenic plastids. The marker-free shoots resulting from direct repeat mediated excision of marker genes have been isolated by vegetative propagation of shoots in the T0 generation. Alternatively, accumulation of marker-free plastomes during growth, development and flowering of T0 plants allows for the collection of seeds that give rise to a high proportion of marker-free T1 seedlings. The procedure enables precise plastome engineering involving insertion of transgenes, point mutations and deletion of genes without the inclusion of any extraneous DNA. The simplicity and convenience of direct repeat excision facilitates its widespread use to isolate marker-free crops.
Collapse
|
7
|
Ren F, Wang L, Li Y, Zhuo W, Xu Z, Guo H, Liu Y, Gao R, Song J. Highly variable chloroplast genome from two endangered Papaveraceae lithophytes Corydalis tomentella and Corydalis saxicola. Ecol Evol 2021; 11:4158-4171. [PMID: 33976800 PMCID: PMC8093665 DOI: 10.1002/ece3.7312] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 01/18/2021] [Accepted: 01/21/2021] [Indexed: 01/27/2023] Open
Abstract
The increasingly wide application of chloroplast (cp) genome super-barcode in taxonomy and the recent breakthrough in cp genetic engineering make the development of new cp gene resources urgent and significant. Corydalis is recognized as the most genotypes complicated and taxonomically challenging plant taxa in Papaveraceae. However, there currently are few reports about cp genomes of the genus Corydalis. In this study, we sequenced four complete cp genomes of two endangered lithophytes Corydalis saxicola and Corydalis tomentella in Corydalis, conducted a comparison of these cp genomes among each other as well as with others of Papaveraceae. The cp genomes have a large genome size of 189,029-190,247 bp, possessing a quadripartite structure and with two highly expanded inverted repeat (IR) regions (length: 41,955-42,350 bp). Comparison between the cp genomes of C. tomentella, C. saxicola, and Papaveraceae species, five NADH dehydrogenase-like genes (ndhF, ndhD, ndhL, ndhG, and ndhE) with psaC, rpl32, ccsA, and trnL-UAG normally located in the SSC region have migrated to IRs, resulting in IR expansion and gene duplication. An up to 9 kb inversion involving five genes (rpl23, ycf2, ycf15, trnI-CAU, and trnL-CAA) was found within IR regions. The accD gene was found to be absent and the ycf1 gene has shifted from the IR/SSC border to the SSC region as a single copy. Phylogenetic analysis based on the sequences of common CDS showed that the genus Corydalis is quite distantly related to the other genera of Papaveraceae, it provided a new clue for recent advocacy to establish a separate Fumariaceae family. Our results revealed one special cp genome structure in Papaveraceae, provided a useful resources for classification of the genus Corydalis, and will be valuable for understanding Papaveraceae evolutionary relationships.
Collapse
Affiliation(s)
- Fengming Ren
- Institute of Medicinal Plant DevelopmentChinese Academy of Medical Sciences & Peking Union Medical CollegeKey Lab of Chinese Medicine Resources ConservationState Administration of Traditional Chinese Medicine of the People's Republic of ChinaBeijingChina
- Medicinal Biological Technology Research CenterChongqing Institute of Medicinal Plant CultivationBio‐Resource Research and Utilization Joint Key Laboratory Sichuan and ChongqingChongqingChina
| | | | - Ying Li
- Institute of Medicinal Plant DevelopmentChinese Academy of Medical Sciences & Peking Union Medical CollegeKey Lab of Chinese Medicine Resources ConservationState Administration of Traditional Chinese Medicine of the People's Republic of ChinaBeijingChina
- Engineering Research Center of Chinese Medicine ResourceMinistry of EducationBeijingChina
| | - Wei Zhuo
- Medicinal Biological Technology Research CenterChongqing Institute of Medicinal Plant CultivationBio‐Resource Research and Utilization Joint Key Laboratory Sichuan and ChongqingChongqingChina
| | - Zhichao Xu
- Institute of Medicinal Plant DevelopmentChinese Academy of Medical Sciences & Peking Union Medical CollegeKey Lab of Chinese Medicine Resources ConservationState Administration of Traditional Chinese Medicine of the People's Republic of ChinaBeijingChina
- Engineering Research Center of Chinese Medicine ResourceMinistry of EducationBeijingChina
| | | | - Yan Liu
- Medicinal Biological Technology Research CenterChongqing Institute of Medicinal Plant CultivationBio‐Resource Research and Utilization Joint Key Laboratory Sichuan and ChongqingChongqingChina
| | - Ranran Gao
- Institute of Medicinal Plant DevelopmentChinese Academy of Medical Sciences & Peking Union Medical CollegeKey Lab of Chinese Medicine Resources ConservationState Administration of Traditional Chinese Medicine of the People's Republic of ChinaBeijingChina
| | - Jingyuan Song
- Institute of Medicinal Plant DevelopmentChinese Academy of Medical Sciences & Peking Union Medical CollegeKey Lab of Chinese Medicine Resources ConservationState Administration of Traditional Chinese Medicine of the People's Republic of ChinaBeijingChina
- Engineering Research Center of Chinese Medicine ResourceMinistry of EducationBeijingChina
| |
Collapse
|
8
|
Caroca R, Howell KA, Malinova I, Burgos A, Tiller N, Pellizzer T, Annunziata MG, Hasse C, Ruf S, Karcher D, Bock R. Knockdown of the plastid-encoded acetyl-CoA carboxylase gene uncovers functions in metabolism and development. PLANT PHYSIOLOGY 2021; 185:1091-1110. [PMID: 33793919 PMCID: PMC8133629 DOI: 10.1093/plphys/kiaa106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 12/11/2020] [Indexed: 06/12/2023]
Abstract
De novo fatty acid biosynthesis in plants relies on a prokaryotic-type acetyl-CoA carboxylase (ACCase) that resides in the plastid compartment. The enzyme is composed of four subunits, one of which is encoded in the plastid genome, whereas the other three subunits are encoded by nuclear genes. The plastid gene (accD) encodes the β-carboxyltransferase subunit of ACCase and is essential for cell viability. To facilitate the functional analysis of accD, we pursued a transplastomic knockdown strategy in tobacco (Nicotiana tabacum). By introducing point mutations into the translational start codon of accD, we obtained stable transplastomic lines with altered ACCase activity. Replacement of the standard initiator codon AUG with UUG strongly reduced AccD expression, whereas replacement with GUG had no detectable effects. AccD knockdown mutants displayed reduced ACCase activity, which resulted in changes in the levels of many but not all species of cellular lipids. Limiting fatty acid availability caused a wide range of macroscopic, microscopic, and biochemical phenotypes, including impaired chloroplast division, reduced seed set, and altered storage metabolism. Finally, while the mutants displayed reduced growth under photoautotrophic conditions, they showed exaggerated growth under heterotrophic conditions, thus uncovering an unexpected antagonistic role of AccD activity in autotrophic and heterotrophic growth.
Collapse
Affiliation(s)
- Rodrigo Caroca
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Katharine A Howell
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Irina Malinova
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Asdrúbal Burgos
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Nadine Tiller
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Tommaso Pellizzer
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | | | - Claudia Hasse
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Daniel Karcher
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| |
Collapse
|
9
|
Escobar-Tovar L, Sierra J, Hernández-Muñoz A, McQuinn RP, Mathioni S, Cordoba E, Colas des Francs-Small C, Meyers BC, Pogson B, León P. Deconvoluting apocarotenoid-mediated retrograde signaling networks regulating plastid translation and leaf development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:1582-1599. [PMID: 33340183 DOI: 10.1111/tpj.15134] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 11/30/2020] [Indexed: 06/12/2023]
Abstract
Signals originating within plastids modulate organelle differentiation by transcriptionally regulating nuclear-encoded genes. These retrograde signals are also integral regulators of plant development, including leaf morphology. The clb5 mutant displays severe leaf morphology defects due to Apocarotenoid Signal 1 (ACS1) accumulation in the developmentally arrested plastid. Transcriptomic analysis of clb5 validates that ACS1 accumulation deregulates hundreds of nuclear genes, including the suppression of most genes encoding plastid ribosomal proteins. Herein, we order the molecular events causing the leaf phenotype associated with the accumulation of ACS1, which includes two consecutive retrograde signaling cascades. Firstly, ACS1 originating in the plastid drives inhibition of plastid translation (IPT) via nuclear transcriptome remodeling of chlororibosomal proteins, requiring light as an essential component. Subsequently, IPT results in leaf morphological defects via a GUN1-dependent pathway shared with seedlings undergoing chemical IPT treatments and is restricted to an early window of the leaf development. Collectively, this work advances our understanding of the complexity within plastid retrograde signaling exemplified by sequential signal exchange and consequences that in a particular temporal and spatial context contribute to the modulation of leaf development.
Collapse
Affiliation(s)
- Lina Escobar-Tovar
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, 62210, Mexico
| | - Julio Sierra
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, 62210, Mexico
| | - Arihel Hernández-Muñoz
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, 62210, Mexico
| | - Ryan P McQuinn
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | - Sandra Mathioni
- Division of Plant Sciences, University of Missouri-Columbia, Columbia, MO, 65211, USA
- Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, Australian National University, Canberra, Australian Capital Territory, 0200, Australia
| | - Elizabeth Cordoba
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, 62210, Mexico
| | - Catherine Colas des Francs-Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Blake C Meyers
- Division of Plant Sciences, University of Missouri-Columbia, Columbia, MO, 65211, USA
- Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, Australian National University, Canberra, Australian Capital Territory, 0200, Australia
| | - Barry Pogson
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | - Patricia León
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, 62210, Mexico
| |
Collapse
|
10
|
Complete chloroplast genome sequencing of sago palm (Metroxylon sagu Rottb.): Molecular structures, comparative analysis and evolutionary significance. GENE REPORTS 2020. [DOI: 10.1016/j.genrep.2020.100662] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
11
|
Agrawal S, Karcher D, Ruf S, Bock R. The Functions of Chloroplast Glutamyl-tRNA in Translation and Tetrapyrrole Biosynthesis. PLANT PHYSIOLOGY 2020; 183:263-276. [PMID: 32071153 PMCID: PMC7210637 DOI: 10.1104/pp.20.00009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 01/31/2020] [Indexed: 06/02/2023]
Abstract
The chloroplast glutamyl-tRNA (tRNAGlu) is unique in that it has two entirely different functions. In addition to acting in translation, it serves as the substrate of glutamyl-tRNA reductase (GluTR), the enzyme catalyzing the committed step in the tetrapyrrole biosynthetic pathway. How the tRNAGlu pool is distributed between the two pathways and whether tRNAGlu allocation limits tetrapyrrole biosynthesis and/or protein biosynthesis remains poorly understood. We generated a series of transplastomic tobacco (Nicotiana tabacum) plants to alter tRNAGlu expression levels and introduced a point mutation into the plastid trnE gene, which has been reported to uncouple protein biosynthesis from tetrapyrrole biosynthesis in chloroplasts of the protist Euglena gracilis We show that, rather than comparable uncoupling of the two pathways, the trnE mutation is lethal in tobacco because it inhibits tRNA processing, thus preventing translation of Glu codons. Ectopic expression of the mutated trnE gene uncovered an unexpected inhibition of glutamyl-tRNA reductase by immature tRNAGlu We further demonstrate that whereas overexpression of tRNAGlu does not affect tetrapyrrole biosynthesis, reduction of GluTR activity through inhibition by tRNAGlu precursors causes tetrapyrrole synthesis to become limiting in early plant development when active photosystem biogenesis provokes a high demand for de novo chlorophyll biosynthesis. Taken together, our findings provide insight into the roles of tRNAGlu at the intersection of protein biosynthesis and tetrapyrrole biosynthesis.
Collapse
Affiliation(s)
- Shreya Agrawal
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Daniel Karcher
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| |
Collapse
|
12
|
Targeting transgene to seed resulted in high rate of morphological abnormalities of Camelina transformants. NOVA BIOTECHNOLOGICA ET CHIMICA 2019. [DOI: 10.2478/nbec-2019-0012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
False flax (Camelina sativa L.) is currently under-exploited but highly promising oilseed crop. Combining Camelina’s attractive agronomic traits with its unprecedented ease for genetic engineering makes it an ideal plant chassis for biotechnology applications, in particular synthetic biology strategies. For targeted expression of transgene particularly to seeds requires identification and application of seed specific promoters. In the present study two cultivars of Camelina, namely Zuzana and Smilowska, were used for transformation at early flowering stage using the floral dip method. The plants were inoculated with Agrobacterium bearing a construct for expression of red fluorescent protein (RFP) under the control of the seed specific cruciferin promoter CRUC from Arabidopsis. Transgenic seeds and plants were identified on the basis of red fluorescence (RFP) and kanamycin resistance. Relatively high transformation efficiency of 8 % was achieved particularly for the cultivar Zuzana. However, many of regenerants exerted developmental deformations such as lack of shoot apical meristem, deformed or absent cotyledons, etc. Furthermore, the activity of the CRUC promoter was still active also in true leaves rendering this promoter as inappropriate for seed targeting of the transgene. Nevertheless, genetic transformation remains a tool for direct modulation of pathways for oil synthesis in oilseed crops.
Collapse
|
13
|
Tang X, Wang Y, Zhang Y, Huang S, Liu Z, Fei D, Feng H. A missense mutation of plastid RPS4 is associated with chlorophyll deficiency in Chinese cabbage (Brassica campestris ssp. pekinensis). BMC PLANT BIOLOGY 2018; 18:130. [PMID: 29940850 PMCID: PMC6019835 DOI: 10.1186/s12870-018-1353-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 06/17/2018] [Indexed: 05/19/2023]
Abstract
BACKGROUND Plastome mutants are ideal resources for elucidating the functions of plastid genes. Numerous studies have been conducted for the function of plastid genes in barley and tobacco; however, related information is limited in Chinese cabbage. RESULTS A chlorophyll-deficient mutant of Chinese cabbage that was derived by ethyl methanesulfonate treatment on isolated microspores showed uniformly pale green inner leaves and slow growth compared with that shown by the wild type "Fukuda 50' ('FT'). Genetic analysis revealed that cdm was cytoplasmically inherited. Physiological and ultrastructural analyses of cdm showed impaired photosynthesis and abnormal chloroplast development. Utilizing next generation sequencing, the complete plastomes of cdm and 'FT' were respectively re-mapped to the reference genome of Chinese cabbage, and an A-to-C base substitution with a mutation ratio higher than 99% was detected. The missense mutation of plastid ribosomal protein S4 led to valine substitution for glycine at residue 193. The expression level of rps4 was analyzed using quantitative real-time PCR and found lower in than in 'FT'. RNA gel-blot assays showed that the abundance of mature 23S rRNA, 16S rRNA, 5S rRNA, and 4.5S rRNA significantly decreased and that the processing of 23S, 16S rRNA, and 4.5S rRNA was seriously impaired, affecting the ribosomal function in cdm. CONCLUSIONS These findings indicated that cdm was a plastome mutant and that chlorophyll deficiency might be due to an A-to-C base substitution of the plastome-encoded rps4 that impaired the rRNA processing and affected the ribosomal function.
Collapse
Affiliation(s)
- Xiaoyan Tang
- College of Horticulture, Liaoning Key Lab of Genetics and Breeding for Cruciferous Vegetable Crops, Shenyang Agricultural University, Shenyang, Liaoning 110866 People’s Republic of China
| | - Yiheng Wang
- College of Horticulture, Liaoning Key Lab of Genetics and Breeding for Cruciferous Vegetable Crops, Shenyang Agricultural University, Shenyang, Liaoning 110866 People’s Republic of China
| | - Yun Zhang
- College of Horticulture, Liaoning Key Lab of Genetics and Breeding for Cruciferous Vegetable Crops, Shenyang Agricultural University, Shenyang, Liaoning 110866 People’s Republic of China
| | - Shengnan Huang
- College of Horticulture, Liaoning Key Lab of Genetics and Breeding for Cruciferous Vegetable Crops, Shenyang Agricultural University, Shenyang, Liaoning 110866 People’s Republic of China
| | - Zhiyong Liu
- College of Horticulture, Liaoning Key Lab of Genetics and Breeding for Cruciferous Vegetable Crops, Shenyang Agricultural University, Shenyang, Liaoning 110866 People’s Republic of China
| | - Danli Fei
- College of Horticulture, Liaoning Key Lab of Genetics and Breeding for Cruciferous Vegetable Crops, Shenyang Agricultural University, Shenyang, Liaoning 110866 People’s Republic of China
| | - Hui Feng
- College of Horticulture, Liaoning Key Lab of Genetics and Breeding for Cruciferous Vegetable Crops, Shenyang Agricultural University, Shenyang, Liaoning 110866 People’s Republic of China
| |
Collapse
|
14
|
Jiang T, Zhang J, Rong L, Feng Y, Wang Q, Song Q, Zhang L, Ouyang M. ECD1 functions as an RNA-editing trans-factor of rps14-149 in plastids and is required for early chloroplast development in seedlings. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:3037-3051. [PMID: 29648606 PMCID: PMC5972661 DOI: 10.1093/jxb/ery139] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/29/2018] [Indexed: 05/18/2023]
Abstract
Chloroplast development is a highly complex process and the regulatory mechanisms have not yet been fully characterized. In this study, we identified Early Chloroplast Development 1 (ECD1), a chloroplast-localized pentatricopeptide repeat protein (PPR) belonging to the PLS subfamily. Inactivation of ECD1 in Arabidopsis led to embryo lethality, and abnormal embryogenesis occurred in ecd1/+ heterozygous plants. A decrease in ECD1 expression induced by RNAi resulted in seedlings with albino cotyledons but normal true leaves. The aberrant morphology and under-developed thylakoid membrane system in cotyledons of RNAi seedlings suggests a role of ECD1 specifically in chloroplast development in seedlings. In cotyledons of ECD1-RNAi plants, RNA-editing of rps14-149 (encoding ribosomal protein S14) was seriously impaired. In addition, dramatically decreased plastid-encoded RNA polymerase-dependent gene expression and abnormal chloroplast rRNA processing were also observed. Taken together, our results indicate that ECD1 is indispensable for chloroplast development at the seedling stage in Arabidopsis.
Collapse
Affiliation(s)
- Tian Jiang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jing Zhang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Liwei Rong
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yanjiang Feng
- Cultivation and Crop Tillage Institute of Heilongjiang Academy of Agricultural Sciences, Harbin, China
| | - Qi Wang
- Cultivation and Crop Tillage Institute of Heilongjiang Academy of Agricultural Sciences, Harbin, China
| | - Qiulai Song
- Cultivation and Crop Tillage Institute of Heilongjiang Academy of Agricultural Sciences, Harbin, China
| | - Lixin Zhang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Min Ouyang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Correspondence:
| |
Collapse
|
15
|
Zoschke R, Bock R. Chloroplast Translation: Structural and Functional Organization, Operational Control, and Regulation. THE PLANT CELL 2018; 30:745-770. [PMID: 29610211 PMCID: PMC5969280 DOI: 10.1105/tpc.18.00016] [Citation(s) in RCA: 140] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/26/2018] [Accepted: 04/01/2018] [Indexed: 05/20/2023]
Abstract
Chloroplast translation is essential for cellular viability and plant development. Its positioning at the intersection of organellar RNA and protein metabolism makes it a unique point for the regulation of gene expression in response to internal and external cues. Recently obtained high-resolution structures of plastid ribosomes, the development of approaches allowing genome-wide analyses of chloroplast translation (i.e., ribosome profiling), and the discovery of RNA binding proteins involved in the control of translational activity have greatly increased our understanding of the chloroplast translation process and its regulation. In this review, we provide an overview of the current knowledge of the chloroplast translation machinery, its structure, organization, and function. In addition, we summarize the techniques that are currently available to study chloroplast translation and describe how translational activity is controlled and which cis-elements and trans-factors are involved. Finally, we discuss how translational control contributes to the regulation of chloroplast gene expression in response to developmental, environmental, and physiological cues. We also illustrate the commonalities and the differences between the chloroplast and bacterial translation machineries and the mechanisms of protein biosynthesis in these two prokaryotic systems.
Collapse
Affiliation(s)
- Reimo Zoschke
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam, Germany
| | - Ralph Bock
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam, Germany
| |
Collapse
|
16
|
Zhao Y, Luo L, Xu J, Xin P, Guo H, Wu J, Bai L, Wang G, Chu J, Zuo J, Yu H, Huang X, Li J. Malate transported from chloroplast to mitochondrion triggers production of ROS and PCD in Arabidopsis thaliana. Cell Res 2018. [PMID: 29540758 PMCID: PMC5939044 DOI: 10.1038/s41422-018-0024-8] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Programmed cell death (PCD) is a fundamental biological process. Deficiency in MOSAIC DEATH 1 (MOD1), a plastid-localized enoyl-ACP reductase, leads to the accumulation of reactive oxygen species (ROS) and PCD, which can be suppressed by mitochondrial complex I mutations, indicating a signal from chloroplasts to mitochondria. However, this signal remains to be elucidated. In this study, through cloning and analyzing a series of mod1 suppressors, we reveal a comprehensive organelle communication pathway that regulates the generation of mitochondrial ROS and triggers PCD. We show that mutations in PLASTIDIAL NAD-DEPENDENT MALATE DEHYDROGENASE (plNAD-MDH), chloroplastic DICARBOXYLATE TRANSPORTER 1 (DiT1) and MITOCHONDRIAL MALATE DEHYDROGENASE 1 (mMDH1) can each rescue the ROS accumulation and PCD phenotypes in mod1, demonstrating a direct communication from chloroplasts to mitochondria via the malate shuttle. Further studies demonstrate that these elements play critical roles in the redox homeostasis and plant growth under different photoperiod conditions. Moreover, we reveal that the ROS level and PCD are significantly increased in malate-treated HeLa cells, which can be dramatically attenuated by knockdown of the human gene MDH2, an ortholog of Arabidopsis mMDH1. These results uncover a conserved malate-induced PCD pathway in plant and animal systems, revolutionizing our understanding of the communication between organelles.
Collapse
Affiliation(s)
- Yannan Zhao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lilan Luo
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jiesi Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Peiyong Xin
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hongyan Guo
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jian Wu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.,Department of Plant Science, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Lin Bai
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Guodong Wang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jinfang Chu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jianru Zuo
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hong Yu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Xun Huang
- University of Chinese Academy of Sciences, Beijing, 100049, China. .,State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Jiayang Li
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
17
|
Rice TSV3 Encoding Obg-Like GTPase Protein Is Essential for Chloroplast Development During the Early Leaf Stage Under Cold Stress. G3-GENES GENOMES GENETICS 2018; 8:253-263. [PMID: 29162684 PMCID: PMC5765353 DOI: 10.1534/g3.117.300249] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Spo0B-associated GTP-binding (Obg) proteins are essential for the viability of nearly all bacteria. However, the detailed roles of Obg proteins in higher plants have not yet been elucidated. In this study, we identified a novel rice (Oryza sativa L.) thermo-sensitive virescent mutant (tsv3) that displayed an albino phenotype at 20° before the three-leaf stage while being a normal green at 32° or even at 20° after the four-leaf stage. The mutant phenotype was consistent with altered chlorophyll content and chloroplast structure in leaves. Map-based cloning and complementation experiments showed that TSV3 encoded a small GTP-binding protein. Subcellular localization studies revealed that TSV3 was localized to the chloroplasts. Expression of TSV3 was high in leaves and weak or undetectable in other tissues, suggesting a tissue-specific expression of TSV3 In the tsv3 mutant, expression levels of genes associated with the biogenesis of the chloroplast ribosome 50S subunit were severely decreased at the three-leaf stage under cold stress (20°), but could be recovered to normal levels at a higher temperature (32°). These observations suggest that the rice nuclear-encoded TSV3 plays important roles in chloroplast development at the early leaf stage under cold stress.
Collapse
|
18
|
Tsugama D, Liu S, Fujino K, Takano T. Possible inhibition of Arabidopsis VIP1-mediated mechanosensory signaling by streptomycin. PLANT SIGNALING & BEHAVIOR 2018; 13:e1521236. [PMID: 30235047 PMCID: PMC6204804 DOI: 10.1080/15592324.2018.1521236] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 08/24/2018] [Accepted: 08/29/2018] [Indexed: 05/21/2023]
Abstract
VIP1 (VIRE2-INTERACTING PROTEIN 1) and its close homologues are Arabidopsis thaliana bZIP proteins regulating stress responses and root tropisms. They are present in the cytoplasm under steady conditions, but transiently accumulate in the nucleus when cells are exposed to mechanical stress such as hypo-osmotic stress and touch. This pattern of changes in subcellular localization is unique to VIP1 and its close homologues, and can be useful to further characterize mechanical stress signaling in plants. A recent study showed that calcium signaling regulates this pattern of subcellular localization. Here, we show that a possible calcium channel inhibitor, streptomycin, also inhibits the nuclear accumulation of VIP1. Candidates for the specific regulators of the mechanosensitive calcium signaling are further discussed.
Collapse
Affiliation(s)
- Daisuke Tsugama
- Laboratory of Crop Physiology, Research Faculty of Agriculture, Hokkaido University, Hokkaido, Japan
- Asian Natural Environmental Science Center, The University of Tokyo, Tokyo, Japan
- CONTACT Daisuke Tsugama
| | - Shenkui Liu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Hangzhou, P.R. China
| | - Kaien Fujino
- Laboratory of Crop Physiology, Research Faculty of Agriculture, Hokkaido University, Hokkaido, Japan
| | - Tetsuo Takano
- Asian Natural Environmental Science Center, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
19
|
Sun YK, Gutmann B, Yap A, Kindgren P, Small I. Editing of Chloroplast rps14 by PPR Editing Factor EMB2261 Is Essential for Arabidopsis Development. FRONTIERS IN PLANT SCIENCE 2018; 9:841. [PMID: 29973946 PMCID: PMC6019781 DOI: 10.3389/fpls.2018.00841] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 05/30/2018] [Indexed: 05/04/2023]
Abstract
RNA editing in plastids is known to be required for embryogenesis, but no single editing event had been shown to be essential. We show that the emb2261-2 mutation is lethal through a failure to express an editing factor that specifically recognizes the rps14-2 site. EMB2261 was predicted to bind the cis-element upstream of the rps14-2 site and genetic complementation with promoters of different strength followed by RNA-seq analysis was conducted to test the correlation between rps14-2 editing and EMB2261 expression. Rps14-2 is the only editing event in Arabidopsis chloroplasts that correlates with EMB2261 expression. Sequence divergence between the cis-element and the EMB2261 protein sequence in plants where rps14-2 editing is not required adds support to the association between them. We conclude that EMB2261 is the specificity factor for rps14-2 editing. This editing event converts P51 in Rps14 to L51, which is conserved among species lacking RNA editing, implying the importance of the editing event to Rps14 function. Rps14 is an essential ribosomal subunit for plastid translation, which, in turn, is essential for Arabidopsis embryogenesis.
Collapse
|
20
|
Scharff LB, Ehrnthaler M, Janowski M, Childs LH, Hasse C, Gremmels J, Ruf S, Zoschke R, Bock R. Shine-Dalgarno Sequences Play an Essential Role in the Translation of Plastid mRNAs in Tobacco. THE PLANT CELL 2017; 29:3085-3101. [PMID: 29133466 PMCID: PMC5757275 DOI: 10.1105/tpc.17.00524] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 10/27/2017] [Accepted: 11/08/2017] [Indexed: 05/23/2023]
Abstract
In prokaryotic systems, the translation initiation of many, though not all, mRNAs depends on interaction between a sequence element upstream of the start codon (the Shine-Dalgarno sequence [SD]) and a complementary sequence in the 3' end of the 16S rRNA (anti-Shine-Dalgarno sequence [aSD]). Although many chloroplast mRNAs harbor putative SDs in their 5' untranslated regions and the aSD displays strong conservation, the functional relevance of SD-aSD interactions in plastid translation is unclear. Here, by generating transplastomic tobacco (Nicotiana tabacum) mutants with point mutations in the aSD coupled with genome-wide analysis of translation by ribosome profiling, we provide a global picture of SD-dependent translation in plastids. We observed a pronounced correlation between weakened predicted SD-aSD interactions and reduced translation efficiency. However, multiple lines of evidence suggest that the strength of the SD-aSD interaction is not the only determinant of the translational output of many plastid mRNAs. Finally, the translation efficiency of mRNAs with strong secondary structures around the start codon is more dependent on the SD-aSD interaction than weakly structured mRNAs. Thus, our data reveal the importance of the aSD in plastid translation initiation, uncover chloroplast genes whose translation is influenced by SD-aSD interactions, and provide insights into determinants of translation efficiency in plastids.
Collapse
Affiliation(s)
- Lars B Scharff
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Miriam Ehrnthaler
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Marcin Janowski
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Liam H Childs
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Claudia Hasse
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Jürgen Gremmels
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Reimo Zoschke
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| |
Collapse
|
21
|
Wang WJ, Zheng KL, Gong XD, Xu JL, Huang JR, Lin DZ, Dong YJ. The rice TCD11 encoding plastid ribosomal protein S6 is essential for chloroplast development at low temperature. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2017; 259:1-11. [PMID: 28483049 DOI: 10.1016/j.plantsci.2017.02.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 02/18/2017] [Accepted: 02/20/2017] [Indexed: 05/20/2023]
Abstract
Plastid ribosome proteins (PRPs) are important components for chloroplast biogenesis and early chloroplast development. Although it has been known that chloroplast ribosomes are similar to bacterial ones, the precise molecular function of ribosomal proteins remains to be elucidated in rice. Here, we identified a novel rice mutant, designated tcd11 (thermo-sensitive chlorophyll-deficient mutant 11), characterized by the albino phenotype until it died at 20°C, while displaying normal phenotype at 32°C. The alteration of leaf color in tcd11 mutants was aligned with chlorophyll (Chl) content and chloroplast development. The map-based cloning and molecular complementation showed that TCD11 encodes the ribosomal small subunit protein S6 in chloroplasts (RPS6). TCD11 was abundantly expressed in leaves, suggesting its different expressions in tissues. In addition, the disruption of TCD11 greatly reduced the transcript levels of certain chloroplasts-associated genes and prevented the assembly of ribosome in chloroplasts at low temperature (20°C), whereas they recovered to nearly normal levels at high temperature (32°C). Thus, our data indicate that TCD11 plays an important role in chloroplast development at low temperature. Upon our knowledge, the observations from this study provide a first glimpse into the importance of RPS6 function in rice chloroplast development.
Collapse
Affiliation(s)
- Wen-Juan Wang
- Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Kai-Lun Zheng
- Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Xiao-Di Gong
- Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China; Institute of Genetics and Developmental Biology Chinese Academy of Sciences, No.1 West Beichen Road, Chaoyang District, Beijing, 10010, China
| | - Jian-Long Xu
- The Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, 12 South Zhong-Guan Cun Street, Beijing 100081, China; Agricultural Genome Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
| | - Ji-Rong Huang
- Institute of Plant Physiology and Ecology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Dong-Zhi Lin
- Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China.
| | - Yan-Jun Dong
- Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China.
| |
Collapse
|
22
|
Shi X, Hanson MR, Bentolila S. Functional diversity of Arabidopsis organelle-localized RNA-recognition motif-containing proteins. WILEY INTERDISCIPLINARY REVIEWS-RNA 2017; 8. [PMID: 28371504 DOI: 10.1002/wrna.1420] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 02/23/2017] [Accepted: 02/24/2017] [Indexed: 12/20/2022]
Abstract
RNA-Binding Proteins (RBPs) play key roles in plant gene expression and regulation. RBPs contain a variety of RNA-binding motifs, the most abundant and most widespread one in eukaryotes is the RNA recognition motif (RRM). Many nucleus-encoded RRM-containing proteins are transported into chloroplasts and/or mitochondria, and participate in various RNA-related processes in plant organelles. Loss of these proteins can have a detrimental effect on some critical processes such as photosynthesis and respiration, sometimes leading to lethality. Progress has been made in the last few years in understanding the function of particular organelle-localized RRM-containing proteins. Members of the Organelle RRM protein (ORRM, some also characterized as Glycine-Rich RNA-Binding Proteins) family and the Chloroplast RiboNucleoProtein (cpRNP) family, are involved in various types of RNA metabolism, including RNA editing, RNA stability and RNA processing. Organelle-localized RRM proteins also function in plant development and stress responses, in some conditions acting as protein or RNA chaperones. There has been recent progress in characterizing the function of organelle-localized RRM proteins in RNA-related processes and how RRM proteins contribute to the normal growth and development of plants. WIREs RNA 2017, 8:e1420. doi: 10.1002/wrna.1420 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Xiaowen Shi
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Maureen R Hanson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Stephane Bentolila
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| |
Collapse
|
23
|
Bieri P, Leibundgut M, Saurer M, Boehringer D, Ban N. The complete structure of the chloroplast 70S ribosome in complex with translation factor pY. EMBO J 2016; 36:475-486. [PMID: 28007896 PMCID: PMC5694952 DOI: 10.15252/embj.201695959] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 11/24/2016] [Accepted: 11/28/2016] [Indexed: 01/21/2023] Open
Abstract
Chloroplasts are cellular organelles of plants and algae that are responsible for energy conversion and carbon fixation by the photosynthetic reaction. As a consequence of their endosymbiotic origin, they still contain their own genome and the machinery for protein biosynthesis. Here, we present the atomic structure of the chloroplast 70S ribosome prepared from spinach leaves and resolved by cryo‐EM at 3.4 Å resolution. The complete structure reveals the features of the 4.5S rRNA, which probably evolved by the fragmentation of the 23S rRNA, and all five plastid‐specific ribosomal proteins. These proteins, required for proper assembly and function of the chloroplast translation machinery, bind and stabilize rRNA including regions that only exist in the chloroplast ribosome. Furthermore, the structure reveals plastid‐specific extensions of ribosomal proteins that extensively remodel the mRNA entry and exit site on the small subunit as well as the polypeptide tunnel exit and the putative binding site of the signal recognition particle on the large subunit. The translation factor pY, involved in light‐ and temperature‐dependent control of protein synthesis, is bound to the mRNA channel of the small subunit and interacts with 16S rRNA nucleotides at the A‐site and P‐site, where it protects the decoding centre and inhibits translation by preventing tRNA binding. The small subunit is locked by pY in a non‐rotated state, in which the intersubunit bridges to the large subunit are stabilized.
Collapse
Affiliation(s)
- Philipp Bieri
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Marc Leibundgut
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Martin Saurer
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Daniel Boehringer
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Nenad Ban
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| |
Collapse
|
24
|
Bellucci M, De Marchis F, Ferradini N, Pompa A, Veronesi F, Rosellini D. A mutant Synechococcus gene encoding glutamate 1-semialdehyde aminotransferase confers gabaculine resistance when expressed in tobacco plastids. PLANT CELL REPORTS 2015; 34:2127-36. [PMID: 26265112 DOI: 10.1007/s00299-015-1856-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 07/20/2015] [Accepted: 08/04/2015] [Indexed: 06/04/2023]
Abstract
KEY MESSAGE A mutant glutamate 1-semialdehyde aminotransferase gene from the Synechococcus , inserted into tobacco plastid DNA by means of particle bombardment and antibiotic selection, conferred gabaculine resistance allowing to attain homoplasmy. Many plant species are recalcitrant to plastid genome transformation. New selections systems may help to overcome this limitation and to extend the application of this technology. A mutant hemL gene from the photosynthetic cyanobacterium Synechococcus, encoding a gabaculine-insensitive glutamate 1-semialdehyde aminotransferase (GSA), is an efficient selectable marker gene for nuclear transformation of tobacco, alfalfa and durum wheat. Since GSA functions in the plastid, we introduced the mutant hemL gene into the tobacco plastid genome along with the conventional antibiotic resistance aadA gene, in the attempt to develop a new selection system for plastome transformation. Although we were unable to directly regenerate gabaculine resistant transplastomic plants, we demonstrated the functionality of hemL in tobacco plastids by using gabaculine selection in the second and third rounds of in vitro selection that permitted to obtain the homoplasmic state in transgenic plants. Thus, the mutant hemL gene functions as a secondary selection marker in tobacco plastids. Our results encourage further attempts to test gabaculine resistant GSA for plastome transformation of crop plants in which gabaculine has stronger regeneration-inhibiting effects with respect to tobacco.
Collapse
Affiliation(s)
- Michele Bellucci
- Institute of Biosciences and Bioresources, Research Division of Perugia, National Research Council (CNR), via della Madonna Alta 130, 06128, Perugia, Italy
| | - Francesca De Marchis
- Institute of Biosciences and Bioresources, Research Division of Perugia, National Research Council (CNR), via della Madonna Alta 130, 06128, Perugia, Italy
| | - Nicoletta Ferradini
- Department of Agricultural Food and Environmental Sciences, University of Perugia, Borgo XX Giugno 74, 06121, Perugia, Italy
| | - Andrea Pompa
- Institute of Biosciences and Bioresources, Research Division of Perugia, National Research Council (CNR), via della Madonna Alta 130, 06128, Perugia, Italy
| | - Fabio Veronesi
- Department of Agricultural Food and Environmental Sciences, University of Perugia, Borgo XX Giugno 74, 06121, Perugia, Italy
| | - Daniele Rosellini
- Department of Agricultural Food and Environmental Sciences, University of Perugia, Borgo XX Giugno 74, 06121, Perugia, Italy.
| |
Collapse
|
25
|
Bock R. Engineering plastid genomes: methods, tools, and applications in basic research and biotechnology. ANNUAL REVIEW OF PLANT BIOLOGY 2015; 66:211-41. [PMID: 25494465 DOI: 10.1146/annurev-arplant-050213-040212] [Citation(s) in RCA: 218] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The small bacterial-type genome of the plastid (chloroplast) can be engineered by genetic transformation, generating cells and plants with transgenic plastid genomes, also referred to as transplastomic plants. The transformation process relies on homologous recombination, thereby facilitating the site-specific alteration of endogenous plastid genes as well as the precisely targeted insertion of foreign genes into the plastid DNA. The technology has been used extensively to analyze chloroplast gene functions and study plastid gene expression at all levels in vivo. Over the years, a large toolbox has been assembled that is now nearly comparable to the techniques available for plant nuclear transformation and that has enabled new applications of transplastomic technology in basic and applied research. This review describes the state of the art in engineering the plastid genomes of algae and land plants (Embryophyta). It provides an overview of the existing tools for plastid genome engineering, discusses current technological limitations, and highlights selected applications that demonstrate the immense potential of chloroplast transformation in several key areas of plant biotechnology.
Collapse
Affiliation(s)
- Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany;
| |
Collapse
|
26
|
Zhou W, Karcher D, Bock R. Identification of enzymes for adenosine-to-inosine editing and discovery of cytidine-to-uridine editing in nucleus-encoded transfer RNAs of Arabidopsis. PLANT PHYSIOLOGY 2014; 166:1985-97. [PMID: 25315605 PMCID: PMC4256874 DOI: 10.1104/pp.114.250498] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 10/11/2014] [Indexed: 05/18/2023]
Abstract
In all organisms, transfer RNAs (tRNAs) contain numerous modified nucleotides. For many base modifications in tRNAs, the functional significance is not well understood, and the enzymes performing the modification reactions are unknown. Here, we have studied members of a family of putative nucleotide deaminases in the model plant Arabidopsis (Arabidopsis thaliana). We show that two Arabidopsis genes encoding homologs of yeast (Saccharomyces cerevisiae) tRNA adenosine deaminases catalyze adenosine-to-inosine editing in position 34 of several cytosolic tRNA species. The encoded proteins (AtTAD2 and AtTAD3, for tRNA-specific adenosine deaminase) localize to the nucleus and interact with each other in planta in bimolecular fluorescence complementation and coimmunoprecipitation assays. Both AtTAD2 and AtTAD3 are encoded by essential genes whose knockout is lethal and leads to arrested embryo development at the globular stage. Knockdown mutants for AtTAD2 and AtTAD3 display reduced growth and inefficient editing from adenosine to inosine in six nucleus-encoded tRNA species. Moreover, upon comparison of DNA and complementary DNA sequences, we discovered cytidine-to-uridine RNA editing in position 32 of two nucleus-encoded serine tRNAs, tRNA-serine(AGA) and tRNA-serine(GCT). This adds a unique type of RNA editing to the modifications occurring in nuclear genome-encoded RNAs in plants.
Collapse
Affiliation(s)
- Wenbin Zhou
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Daniel Karcher
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| |
Collapse
|
27
|
Tiller N, Bock R. The translational apparatus of plastids and its role in plant development. MOLECULAR PLANT 2014; 7:1105-20. [PMID: 24589494 PMCID: PMC4086613 DOI: 10.1093/mp/ssu022] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 02/26/2014] [Indexed: 05/18/2023]
Abstract
Chloroplasts (plastids) possess a genome and their own machinery to express it. Translation in plastids occurs on bacterial-type 70S ribosomes utilizing a set of tRNAs that is entirely encoded in the plastid genome. In recent years, the components of the chloroplast translational apparatus have been intensely studied by proteomic approaches and by reverse genetics in the model systems tobacco (plastid-encoded components) and Arabidopsis (nucleus-encoded components). This work has provided important new insights into the structure, function, and biogenesis of chloroplast ribosomes, and also has shed fresh light on the molecular mechanisms of the translation process in plastids. In addition, mutants affected in plastid translation have yielded strong genetic evidence for chloroplast genes and gene products influencing plant development at various levels, presumably via retrograde signaling pathway(s). In this review, we describe recent progress with the functional analysis of components of the chloroplast translational machinery and discuss the currently available evidence that supports a significant impact of plastid translational activity on plant anatomy and morphology.
Collapse
Affiliation(s)
- Nadine Tiller
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| |
Collapse
|
28
|
Häusler RE, Heinrichs L, Schmitz J, Flügge UI. How sugars might coordinate chloroplast and nuclear gene expression during acclimation to high light intensities. MOLECULAR PLANT 2014; 7:1121-37. [PMID: 25006007 DOI: 10.1093/mp/ssu064] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The concept of retrograde control of nuclear gene expression assumes the generation of signals inside the chloroplasts, which are either released from or sensed inside of the organelle. In both cases, downstream signaling pathways lead eventually to a differential regulation of nuclear gene expression and the production of proteins required in the chloroplast. This concept appears reasonable as the majority of the over 3000 predicted plastidial proteins are encoded by nuclear genes. Hence, the nucleus needs information on the status of the chloroplasts, such as during acclimation responses, which trigger massive changes in the protein composition of the thylakoid membrane and in the stroma. Here, we propose an additional control mechanism of nuclear- and plastome-encoded photosynthesis genes, taking advantage of pathways involved in sugar- or hormonal signaling. Sugars are major end products of photosynthesis and their contents respond very sensitively to changes in light intensities. Based on recent findings, we ask the question as to whether the carbohydrate status outside the chloroplast can be directly sensed within the chloroplast stroma. Sugars might synchronize the responsiveness of both genomes and thereby help to coordinate the expression of plastome- and nuclear-encoded photosynthesis genes in concert with other, more specific retrograde signals.
Collapse
Affiliation(s)
- Rainer E Häusler
- Department of Botany II, Cologne Biocenter, University of Cologne, Zülpicherstr. 47b, 50674 Cologne, Germany
| | - Luisa Heinrichs
- Department of Botany II, Cologne Biocenter, University of Cologne, Zülpicherstr. 47b, 50674 Cologne, Germany
| | - Jessica Schmitz
- Department of Botany II, Cologne Biocenter, University of Cologne, Zülpicherstr. 47b, 50674 Cologne, Germany Present address: Plant Molecular Physiology and Biotechnology, Heinrich-Heine-University, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Ulf-Ingo Flügge
- Department of Botany II, Cologne Biocenter, University of Cologne, Zülpicherstr. 47b, 50674 Cologne, Germany
| |
Collapse
|
29
|
Scharff LB, Bock R. Synthetic biology in plastids. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 78:783-98. [PMID: 24147738 DOI: 10.1111/tpj.12356] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 10/08/2013] [Accepted: 10/16/2013] [Indexed: 05/21/2023]
Abstract
Plastids (chloroplasts) harbor a small gene-dense genome that is amenable to genetic manipulation by transformation. During 1 billion years of evolution from the cyanobacterial endosymbiont to present-day chloroplasts, the plastid genome has undergone a dramatic size reduction, mainly as a result of gene losses and the large-scale transfer of genes to the nuclear genome. Thus the plastid genome can be regarded as a naturally evolved miniature genome, the gradual size reduction and compaction of which has provided a blueprint for the design of minimum genomes. Furthermore, because of the largely prokaryotic genome structure and gene expression machinery, the high transgene expression levels attainable in transgenic chloroplasts and the very low production costs in plant systems, the chloroplast lends itself to synthetic biology applications that are directed towards the efficient synthesis of green chemicals, biopharmaceuticals and other metabolites of commercial interest. This review describes recent progress with the engineering of plastid genomes with large constructs of foreign or synthetic DNA, and highlights the potential of the chloroplast as a model system in bottom-up and top-down synthetic biology approaches.
Collapse
Affiliation(s)
- Lars B Scharff
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany
| | | |
Collapse
|
30
|
Gong X, Su Q, Lin D, Jiang Q, Xu J, Zhang J, Teng S, Dong Y. The rice OsV4 encoding a novel pentatricopeptide repeat protein is required for chloroplast development during the early leaf stage under cold stress. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2014; 56:400-10. [PMID: 24289830 DOI: 10.1111/jipb.12138] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 11/27/2013] [Indexed: 05/04/2023]
Abstract
Pentatricopeptide repeat (PPR) proteins, characterized by tandem arrays of a 35 amino acid motif, have been suggested to play central and broad roles in modulating the expression of organelle genes in plants. However, the molecular mechanisms of most rice PPR genes remains unclear. In this paper, we isolated and characterized a temperature-conditional virescent mutant, OsV4, in rice (Oryza sativa cultivar Jiahua1 (WT, japonica rice variety)). The mutant displays albino phenotype and abnormal chloroplasts at the three leaf stage, which gradually turns green after the four leaf stage at a low temperature (20 °C). But the mutant always develops green leaves and well-developed chloroplasts at a high temperature (32 °C). Genetic and molecular analyses uncovered that OsV4 encodes a novel chloroplast-targeted PPR protein including four PPR motifs. Further investigations show that the mutant phenotype is associated with changes in chlorophyll content and chloroplast development. The OsV4 transcripts only accumulate to high levels in young leaves, indicating that its expression is tissue-specific. In addition, transcript levels of some ribosomal components and plastid-encoded polymerase-dependent genes are dramatically reduced in the albino mutants grown at 20 °C. These findings suggest that OsV4 plays an important role during early chloroplast development under cold stress in rice.
Collapse
Affiliation(s)
- Xiaodi Gong
- Development Center of Plant Germplasm Resources, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Schmitz J, Heinrichs L, Scossa F, Fernie AR, Oelze ML, Dietz KJ, Rothbart M, Grimm B, Flügge UI, Häusler RE. The essential role of sugar metabolism in the acclimation response of Arabidopsis thaliana to high light intensities. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:1619-36. [PMID: 24523502 PMCID: PMC3967092 DOI: 10.1093/jxb/eru027] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Retrograde signals from chloroplasts are thought to control the expression of nuclear genes associated with plastidial processes such as acclimation to varying light conditions. Arabidopsis mutants altered in the day and night path of photoassimilate export from the chloroplasts served as tools to study the involvement of carbohydrates in high light (HL) acclimation. A double mutant impaired in the triose phosphate/phosphate translocator (TPT) and ADP-glucose pyrophosphorylase (AGPase) (adg1-1/tpt-2) exhibits a HL-dependent depletion in endogenous carbohydrates combined with a severe growth and photosynthesis phenotype. The acclimation response of mutant and wild-type plants has been assessed in time series after transfer from low light (LL) to HL by analysing photosynthetic performance, carbohydrates, MgProtoIX (a chlorophyll precursor), and the ascorbate/glutathione redox system, combined with microarray-based transcriptomic and GC-MS-based metabolomic approaches. The data indicate that the accumulation of soluble carbohydrates (predominantly glucose) acts as a short-term response to HL exposure in both mutant and wild-type plants. Only if carbohydrates are depleted in the long term (e.g. after 2 d) is the acclimation response impaired, as observed in the adg1-1/tpt-2 double mutant. Furthermore, meta-analyses conducted with in-house and publicly available microarray data suggest that, in the long term, reactive oxygen species such as H₂O₂ can replace carbohydrates as signals. Moreover, a cross-talk exists between genes associated with the regulation of starch and lipid metabolism. The involvement of genes responding to phytohormones in HL acclimation appears to be less likely. Various candidate genes involved in retrograde control of nuclear gene expression emerged from the analyses of global gene expression.
Collapse
Affiliation(s)
- Jessica Schmitz
- Department of Botany II, Cologne Biocenter, University of Cologne, Zülpicher Straße 47b, D-50674 Cologne, Germany
- * Present address: Plant Molecular Physiology and Biotechnology, Heinrich-Heine-University, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
| | - Luisa Heinrichs
- Department of Botany II, Cologne Biocenter, University of Cologne, Zülpicher Straße 47b, D-50674 Cologne, Germany
| | - Federico Scossa
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam OT Golm, Germany
- Agriculture Research Council, Research Center for Vegetable Crops, Via Cavalleggeri 25, 84098 Pontecagnano (Salerno), Italy
| | - Alisdair R. Fernie
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam OT Golm, Germany
| | - Marie-Luise Oelze
- Biochemistry and Physiology of Plants, University of Bielefeld, Universitätsstraße 25, D-33615 Bielefeld, Germany
| | - Karl-Josef Dietz
- Biochemistry and Physiology of Plants, University of Bielefeld, Universitätsstraße 25, D-33615 Bielefeld, Germany
| | - Maxi Rothbart
- Institute of Biology, Plant Physiology, Humboldt-University Berlin, Philippstraße 13, D-10115 Berlin, Germany
| | - Bernhard Grimm
- Institute of Biology, Plant Physiology, Humboldt-University Berlin, Philippstraße 13, D-10115 Berlin, Germany
| | - Ulf-Ingo Flügge
- Department of Botany II, Cologne Biocenter, University of Cologne, Zülpicher Straße 47b, D-50674 Cologne, Germany
| | - Rainer E. Häusler
- Department of Botany II, Cologne Biocenter, University of Cologne, Zülpicher Straße 47b, D-50674 Cologne, Germany
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|
32
|
Ehrnthaler M, Scharff LB, Fleischmann TT, Hasse C, Ruf S, Bock R. Synthetic lethality in the tobacco plastid ribosome and its rescue at elevated growth temperatures. THE PLANT CELL 2014; 26:765-76. [PMID: 24563204 PMCID: PMC3967039 DOI: 10.1105/tpc.114.123240] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 01/17/2014] [Accepted: 01/30/2014] [Indexed: 05/21/2023]
Abstract
Consistent with their origin from cyanobacteria, plastids (chloroplasts) perform protein biosynthesis on bacterial-type 70S ribosomes. The plastid genomes of seed plants contain a conserved set of ribosomal protein genes. Three of these have proven to be nonessential for translation and, thus, for cellular viability: rps15, rpl33, and rpl36. To help define the minimum ribosome, here, we examined whether more than one of these nonessential plastid ribosomal proteins can be removed from the 70S ribosome. To that end, we constructed all possible double knockouts for the S15, L33, and L36 ribosomal proteins by stable transformation of the tobacco (Nicotiana tabacum) plastid genome. We find that, although S15 and L33 function in different ribosomal particles (30S and 50S, respectively), their combined deletion from the plastid genome results in synthetic lethality under autotrophic conditions. Interestingly, the lethality can be overcome by growth under elevated temperatures due to an improved efficiency of plastid ribosome biogenesis. Our results reveal functional interactions between protein and RNA components of the 70S ribosome and uncover the interdependence of the biogenesis of the two ribosomal subunits. In addition, our findings suggest that defining a minimal set of plastid genes may prove more complex than generally believed.
Collapse
Affiliation(s)
| | | | | | - Claudia Hasse
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476
Potsdam-Golm, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476
Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476
Potsdam-Golm, Germany
| |
Collapse
|
33
|
Mudd EA, Madesis P, Avila EM, Day A. Excision of plastid marker genes using directly repeated DNA sequences. Methods Mol Biol 2014; 1132:107-23. [PMID: 24599849 DOI: 10.1007/978-1-62703-995-6_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Excision of marker genes using DNA direct repeats makes use of the predominant homologous recombination pathways present in the plastids of algae and plants. The method is simple, efficient, and widely applicable to plants and microalgae. Marker excision frequency is dependent on the length and number of directly repeated sequences. When two repeats are used a repeat size of greater than 600 bp promotes efficient excision of the marker gene. A wide variety of sequences can be used to make the direct repeats. Only a single round of transformation is required, and there is no requirement to introduce site-specific recombinases by retransformation or sexual crosses. Selection is used to maintain the marker and ensure homoplasmy of transgenic plastid genomes. Release of selection allows the accumulation of marker-free plastid genomes generated by marker excision, which is spontaneous, random, and a unidirectional process. Positive selection is provided by linking marker excision to restoration of the coding region of an herbicide resistance gene from two overlapping but incomplete coding regions. Cytoplasmic sorting allows the segregation of cells with marker-free transgenic plastids. The marker-free shoots resulting from direct repeat-mediated excision of marker genes have been isolated by vegetative propagation of shoots in the T0 generation. Alternatively, accumulation of marker-free plastid genomes during growth, development and flowering of T0 plants allows the collection of seeds that give rise to a high proportion of marker-free T1 seedlings. The simplicity and convenience of direct repeat excision facilitates its widespread use to isolate marker-free crops.
Collapse
Affiliation(s)
- Elisabeth A Mudd
- Faculty of Life Sciences, The University of Manchester, Manchester, UK
| | | | | | | |
Collapse
|
34
|
Liu X, Zheng M, Wang R, Wang R, An L, Rodermel SR, Yu F. Genetic interactions reveal that specific defects of chloroplast translation are associated with the suppression of var2-mediated leaf variegation. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2013; 55:979-93. [PMID: 23721655 DOI: 10.1111/jipb.12078] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 05/21/2013] [Indexed: 05/09/2023]
Abstract
Arabidopsis thaliana L. yellow variegated (var2) mutant is defective in a chloroplast FtsH family metalloprotease, AtFtsH2/VAR2, and displays an intriguing green and white leaf variegation. This unique var2-mediated leaf variegation offers a simple yet powerful tool for dissecting the genetic regulation of chloroplast development. Here, we report the isolation and characterization of a new var2 suppressor gene, SUPPRESSOR OF VARIEGATION8 (SVR8), which encodes a putative chloroplast ribosomal large subunit protein, L24. Mutations in SVR8 suppress var2 leaf variegation at ambient temperature and partially suppress the cold-induced chlorosis phenotype of var2. Loss of SVR8 causes unique chloroplast rRNA processing defects, particularly the 23S-4.5S dicistronic precursor. The recovery of the major abnormal processing site in svr8 23S-4.5S precursor indicate that it does not lie in the same position where SVR8/L24 binds on the ribosome. Surprisingly, we found that the loss of a chloroplast ribosomal small subunit protein, S21, results in aberrant chloroplast rRNA processing but not suppression of var2 variegation. These findings suggest that the disruption of specific aspects of chloroplast translation, rather than a general impairment in chloroplast translation, suppress var2 variegation and the existence of complex genetic interactions in chloroplast development.
Collapse
Affiliation(s)
- Xiayan Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | | | | | | | | | | | | |
Collapse
|
35
|
Alkatib S, Scharff LB, Rogalski M, Fleischmann TT, Matthes A, Seeger S, Schöttler MA, Ruf S, Bock R. The contributions of wobbling and superwobbling to the reading of the genetic code. PLoS Genet 2012; 8:e1003076. [PMID: 23166520 PMCID: PMC3499367 DOI: 10.1371/journal.pgen.1003076] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 09/25/2012] [Indexed: 12/31/2022] Open
Abstract
Reduced bacterial genomes and most genomes of cell organelles (chloroplasts and mitochondria) do not encode the full set of 32 tRNA species required to read all triplets of the genetic code according to the conventional wobble rules. Superwobbling, in which a single tRNA species that contains a uridine in the wobble position of the anticodon reads an entire four-fold degenerate codon box, has been suggested as a possible mechanism for how tRNA sets can be reduced. However, the general feasibility of superwobbling and its efficiency in the various codon boxes have remained unknown. Here we report a complete experimental assessment of the decoding rules in a typical prokaryotic genetic system, the plastid genome. By constructing a large set of transplastomic knock-out mutants for pairs of isoaccepting tRNA species, we show that superwobbling occurs in all codon boxes where it is theoretically possible. Phenotypic characterization of the transplastomic mutant plants revealed that the efficiency of superwobbling varies in a codon box-dependent manner, but--contrary to previous suggestions--it is independent of the number of hydrogen bonds engaged in codon-anticodon interaction. Finally, our data provide experimental evidence of the minimum tRNA set comprising 25 tRNA species, a number lower than previously suggested. Our results demonstrate that all triplets with pyrimidines in third codon position are dually decoded: by a tRNA species utilizing standard base pairing or wobbling and by a second tRNA species employing superwobbling. This has important implications for the interpretation of the genetic code and will aid the construction of synthetic genomes with a minimum-size translational apparatus.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| |
Collapse
|
36
|
Venkatesh J, Park SW. Plastid genetic engineering in Solanaceae. PROTOPLASMA 2012; 249:981-99. [PMID: 22395455 PMCID: PMC3459085 DOI: 10.1007/s00709-012-0391-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 02/21/2012] [Indexed: 05/23/2023]
Abstract
Plastid genetic engineering has come of age, becoming today an attractive alternative approach for the expression of foreign genes, as it offers several advantages over nuclear transformants. Significant progress has been made in plastid genetic engineering in tobacco and other Solanaceae plants, through the use of improved regeneration procedures and transformation vectors with efficient promoters and untranslated regions. Many genes encoding for industrially important proteins and vaccines, as well as genes conferring important agronomic traits, have been stably integrated and expressed in the plastid genome. Despite these advances, it remains a challenge to achieve marked levels of plastid transgene expression in non-green tissues. In this review, we summarize the basic requirements of plastid genetic engineering and discuss the current status, limitations, and the potential of plastid transformation for expanding future studies relating to Solanaceae plants.
Collapse
Affiliation(s)
- Jelli Venkatesh
- Department of Molecular Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 143-701 Republic of Korea
| | - Se Won Park
- Department of Molecular Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 143-701 Republic of Korea
| |
Collapse
|
37
|
Alkatib S, Fleischmann TT, Scharff LB, Bock R. Evolutionary constraints on the plastid tRNA set decoding methionine and isoleucine. Nucleic Acids Res 2012; 40:6713-24. [PMID: 22553362 PMCID: PMC3413147 DOI: 10.1093/nar/gks350] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 03/27/2012] [Accepted: 03/31/2012] [Indexed: 12/31/2022] Open
Abstract
The plastid (chloroplast) genomes of seed plants typically encode 30 tRNAs. Employing wobble and superwobble mechanisms, most codon boxes are read by only one or two tRNA species. The reduced set of plastid tRNAs follows the evolutionary trend of organellar genomes to shrink in size and coding capacity. A notable exception is the AUN codon box specifying methionine and isoleucine, which is decoded by four tRNA species in nearly all seed plants. However, three of these four tRNA genes were lost from the genomes of some parasitic plastid-containing lineages, possibly suggesting that less than four tRNA species could be sufficient to decode the triplets in the AUN box. To test this hypothesis, we have performed knockout experiments for the four AUN-decoding tRNAs in tobacco (Nicotiana tabacum) plastids. We find that all four tRNA genes are essential under both autotrophic and heterotrophic growth conditions, possibly suggesting tRNA import into plastids of parasitic plastid-bearing species. Phylogenetic analysis of the four plastid tRNA genes reveals striking conservation of all those bacterial features that are involved in discrimination between the different tRNA species containing CAU anticodons.
Collapse
Affiliation(s)
| | | | | | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| |
Collapse
|
38
|
Lentz EM, Garaicoechea L, Alfano EF, Parreño V, Wigdorovitz A, Bravo-Almonacid FF. Translational fusion and redirection to thylakoid lumen as strategies to improve the accumulation of a camelid antibody fragment in transplastomic tobacco. PLANTA 2012; 236:703-14. [PMID: 22526499 DOI: 10.1007/s00425-012-1642-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 03/28/2012] [Indexed: 05/03/2023]
Abstract
Fragments from camelid single-chain antibodies known as VHHs or nanobodies represent a valuable tool in diagnostics, investigation and passive immunity therapy. Here, we explored different strategies to improve the accumulation of a neutralizing VHH antibody against rotavirus in tobacco transplastomic plants. First, we attempted to express the VHH in the chloroplast stroma and then two alternative strategies were carried out to improve the expression levels: expression as a translational fusion to the β-glucuronidase enzyme (GUS-E-VHH), and redirection of the VHH into the thylakoid lumen (pep-VHH). Every attempt to produce transplastomic plants expressing the VHH in the stroma was futile. The transgene turned out to be unstable and the presence of the VHH protein was almost undetectable. Although pep-VHH plants also presented some of the aforementioned problems, higher accumulation of the nanobody was observed (2-3% of the total soluble proteins). The use of β-glucuronidase as a partner protein turned out to be a successful strategy and expression levels reached 3% of the total soluble proteins. The functionality of the VHHs produced by pep-VHH and GUS-E-VHH plants was studied and compared with that of the antibody produced in Escherichia coli. This work contributes to optimizing the expression of VHH in transplastomic plants. Recombinant proteins could be obtained either by accumulation in the thylakoid lumen or as a fusion protein with β-glucuronidase, and both strategies allow for further optimization.
Collapse
Affiliation(s)
- Ezequiel M Lentz
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), CONICET, Vuelta de Obligado 2490, C1428ADN, Buenos Aires, Argentina
| | | | | | | | | | | |
Collapse
|
39
|
Yin T, Pan G, Liu H, Wu J, Li Y, Zhao Z, Fu T, Zhou Y. The chloroplast ribosomal protein L21 gene is essential for plastid development and embryogenesis in Arabidopsis. PLANTA 2012; 235:907-21. [PMID: 22105802 DOI: 10.1007/s00425-011-1547-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 10/31/2011] [Indexed: 05/22/2023]
Abstract
Embryogenesis in higher plants is controlled by a complex gene network. Identification and characterization of genes essential for embryogenesis will provide insights into the early events in embryo development. In this study, a novel mutant with aborted seed development (asd) was identified in Arabidopsis. The asd mutant produced about 25% of albino seeds at the early stage of silique development. The segregation of normal and albino seeds was inherited as a single recessive embryo-lethal trait. The gene disrupted in the asd mutant was isolated through map-based cloning. The mutated gene contains a single base change (A to C) in the coding region of RPL21C (At1g35680) that is predicted to encode the chloroplast 50S ribosomal protein L21. Allele test with other two T-DNA insertion lines in RPL21C and a complementation test demonstrated that the mutation in RPL21C was responsible for the asd phenotype. RPL21C exhibits higher expression in leaves and flowers compared with expression levels in roots and developing seeds. The RPL21C-GFP fusion protein was localized in chloroplasts. Cytological observations showed that the asd embryo development was arrested at the globular stage. There were no plastids with normal thylakoids and as a result no normal chloroplasts formed in mutant cells, indicating an indispensable role of the ASD gene in chloroplasts biogenesis. Our studies suggest that the chloroplast ribosomal protein L21 gene is required for chloroplast development and embryogenesis in Arabidopsis.
Collapse
Affiliation(s)
- Tuanzhang Yin
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | | | | | | | | | | | | | | |
Collapse
|
40
|
Uthaipaisanwong P, Chanprasert J, Shearman JR, Sangsrakru D, Yoocha T, Jomchai N, Jantasuriyarat C, Tragoonrung S, Tangphatsornruang S. Characterization of the chloroplast genome sequence of oil palm (Elaeis guineensis Jacq.). Gene 2012; 500:172-80. [PMID: 22487870 DOI: 10.1016/j.gene.2012.03.061] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 03/09/2012] [Accepted: 03/23/2012] [Indexed: 10/28/2022]
Abstract
Oil palm (Elaeis guineensis Jacq.) is an economically important crop, which is grown for oil production. To better understand the molecular basis of oil palm chloroplasts, we characterized the complete chloroplast (cp) genome sequence obtained from 454 pyrosequencing. The oil palm cp genome is 156,973 bp in length consisting of a large single-copy region of 85,192 bp flanked on each side by inverted repeats of 27,071 bp with a small single-copy region of 17,639 bp joining the repeats. The genome contains 112 unique genes: 79 protein-coding genes, 4 ribosomal RNA genes and 29 tRNA genes. By aligning the cp genome sequence with oil palm cDNA sequences, we observed 18 non-silent and 10 silent RNA editing events among 19 cp protein-coding genes. Creation of an initiation codon by RNA editing in rpl2 has been reported in several monocots and was also found in the oil palm cp genome. Fifty common chloroplast protein-coding genes from 33 plant taxa were used to construct ML and MP phylogenetic trees. Their topologies are similar and strongly support for the position of E. guineensis as the sister of closely related species Phoenix dactylifera in Arecaceae (palm families) of monocot subtrees.
Collapse
Affiliation(s)
- P Uthaipaisanwong
- National Center for Genetic Engineering and Biotechnology, 113 Phaholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand
| | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Heinrichs L, Schmitz J, Flügge UI, Häusler RE. The Mysterious Rescue of adg1-1/tpt-2 - an Arabidopsis thaliana Double Mutant Impaired in Acclimation to High Light - by Exogenously Supplied Sugars. FRONTIERS IN PLANT SCIENCE 2012; 3:265. [PMID: 23233856 PMCID: PMC3516064 DOI: 10.3389/fpls.2012.00265] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 11/12/2012] [Indexed: 05/05/2023]
Abstract
An Arabidopsis thaliana double mutant (adg1-1/tpt-2) defective in the day- and night-path of photoassimilate export from the chloroplast due to a knockout in the triose phosphate/phosphate translocator (TPT; tpt-2) and a lack of starch [mutation in ADP glucose pyrophosphorylase (AGPase); adg1-1] exhibits severe growth retardation, a decrease in the photosynthetic capacity, and a high chlorophyll fluorescence (HCF) phenotype under high light conditions. These phenotypes could be rescued when the plants were grown on sucrose (Suc) or glucose (Glc). Here we address the question whether Glc-sensing hexokinase1 (HXK1) defective in the Glc insensitive 2 (gin2-1) mutant is involved in the sugar-dependent rescue of adg1-1/tpt-2. Triple mutants defective in the TPT, AGPase, and HXK1 (adg1-1/tpt-2/gin2-1) were established as homozygous lines and grown together with Col-0 and Landsberg erecta (Ler) wild-type plants, gin2-1, the adg1-1/tpt-2 double mutant, and the adg1-1/tpt-2/gpt2-1 triple mutant [additionally defective in the glucose 6-phosphate/phosphate translocator 2 (GPT2)] on agar in the presence or absence of 50 mM of each Glc, Suc, or fructose (Fru). The growth phenotype of the double mutant and both triple mutants could be rescued to a similar extent only by Glc and Suc, but not by Fru. All three sugars were capable of rescuing the HCF and photosynthesis phenotype, irrespectively of the presence or absence of HXK1. Quantitative RT-PCR analyses of sugar-responsive genes revealed that plastidial HXK (pHXK) was up-regulated in adg1-1/tpt-2 plants grown on sugars, but showed no response in adg1-1/tpt-2/gin2-1. It appears likely that soluble sugars are directly taken up by the chloroplasts and enter further metabolism, which consumes ATP and NADPH from the photosynthetic light reaction and thereby rescues the photosynthesis phenotype of the double mutant. The implication of sugar turnover and probably signaling inside the chloroplasts for the concept of retrograde signaling is discussed.
Collapse
Affiliation(s)
- Luisa Heinrichs
- Department of Botany II, Cologne Biocenter, University of CologneCologne, Germany
| | - Jessica Schmitz
- Department of Botany II, Cologne Biocenter, University of CologneCologne, Germany
| | - Ulf-Ingo Flügge
- Department of Botany II, Cologne Biocenter, University of CologneCologne, Germany
| | - Rainer E. Häusler
- Department of Botany II, Cologne Biocenter, University of CologneCologne, Germany
- *Correspondence: Rainer E. Häusler, Department of Botany II, Cologne Biocenter, University of Cologne, Zülpicherstr. 47b, 50674 Cologne, Germany. e-mail:
| |
Collapse
|
42
|
|
43
|
Tiller N, Weingartner M, Thiele W, Maximova E, Schöttler MA, Bock R. The plastid-specific ribosomal proteins of Arabidopsis thaliana can be divided into non-essential proteins and genuine ribosomal proteins. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 69:302-16. [PMID: 21923745 DOI: 10.1111/j.1365-313x.2011.04791.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Plastid translation occurs on bacterial-type 70S ribosomes consisting of a large (50S) subunit and a small (30S) subunit. The vast majority of plastid ribosomal proteins have orthologs in bacteria. In addition, plastids also possess a small set of unique ribosomal proteins, so-called plastid-specific ribosomal proteins (PSRPs). The functions of these PSRPs are unknown, but, based on structural studies, it has been proposed that they may represent accessory proteins involved in translational regulation. Here we have investigated the functions of five PSRPs using reverse genetics in the model plant Arabidopsis thaliana. By analyzing T-DNA insertion mutants and RNAi lines, we show that three PSRPs display characteristics of genuine ribosomal proteins, in that down-regulation of their expression led to decreased accumulation of the 30S or 50S subunit of the plastid ribosomes, resulting in plastid translational deficiency. In contrast, two other PSRPs can be knocked out without visible or measurable phenotypic consequences. Our data suggest that PSRPs fall into two types: (i) PSRPs that have a structural role in the ribosome and are bona fide ribosomal proteins, and (ii) non-essential PSRPs that are not required for stable ribosome accumulation and translation under standard greenhouse conditions.
Collapse
Affiliation(s)
- Nadine Tiller
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | | | | | | | | | | |
Collapse
|
44
|
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.
Collapse
Affiliation(s)
- Kensuke Kusumi
- Department of Biology, Kyushu University, Fukuoka 812-8581, Japan.
| | | | | | | | | | | |
Collapse
|
45
|
Fleischmann TT, Scharff LB, Alkatib S, Hasdorf S, Schöttler MA, Bock R. Nonessential plastid-encoded ribosomal proteins in tobacco: a developmental role for plastid translation and implications for reductive genome evolution. THE PLANT CELL 2011; 23:3137-55. [PMID: 21934145 PMCID: PMC3203423 DOI: 10.1105/tpc.111.088906] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 08/18/2011] [Accepted: 09/03/2011] [Indexed: 05/20/2023]
Abstract
Plastid genomes of higher plants contain a conserved set of ribosomal protein genes. Although plastid translational activity is essential for cell survival in tobacco (Nicotiana tabacum), individual plastid ribosomal proteins can be nonessential. Candidates for nonessential plastid ribosomal proteins are ribosomal proteins identified as nonessential in bacteria and those whose genes were lost from the highly reduced plastid genomes of nonphotosynthetic plastid-bearing lineages (parasitic plants, apicomplexan protozoa). Here we report the reverse genetic analysis of seven plastid-encoded ribosomal proteins that meet these criteria. We have introduced knockout alleles for the corresponding genes into the tobacco plastid genome. Five of the targeted genes (ribosomal protein of the large subunit22 [rpl22], rpl23, rpl32, ribosomal protein of the small subunit3 [rps3], and rps16) were shown to be essential even under heterotrophic conditions, despite their loss in at least some parasitic plastid-bearing lineages. This suggests that nonphotosynthetic plastids show elevated rates of gene transfer to the nuclear genome. Knockout of two ribosomal protein genes, rps15 and rpl36, yielded homoplasmic transplastomic mutants, thus indicating nonessentiality. Whereas Δrps15 plants showed only a mild phenotype, Δrpl36 plants were severely impaired in photosynthesis and growth and, moreover, displayed greatly altered leaf morphology. This finding provides strong genetic evidence that chloroplast translational activity influences leaf development, presumably via a retrograde signaling pathway.
Collapse
Affiliation(s)
| | | | | | | | | | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| |
Collapse
|
46
|
Adam Z, Charuvi D, Tsabari O, Knopf RR, Reich Z. Biogenesis of thylakoid networks in angiosperms: knowns and unknowns. PLANT MOLECULAR BIOLOGY 2011; 76:221-34. [PMID: 20859754 DOI: 10.1007/s11103-010-9693-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Accepted: 09/10/2010] [Indexed: 05/06/2023]
Abstract
Aerobic life on Earth depends on oxygenic photosynthesis. This fundamentally important process is carried out within an elaborate membranous system, called the thylakoid network. In angiosperms, thylakoid networks are constructed almost from scratch by an intricate, light-dependent process in which lipids, proteins, and small organic molecules are assembled into morphologically and functionally differentiated, three-dimensional lamellar structures. In this review, we summarize the major events that occur during this complex, largely elusive process, concentrating on those that are directly involved in network formation and potentiation and highlighting gaps in our knowledge, which, as hinted by the title, are substantial.
Collapse
Affiliation(s)
- Zach Adam
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Hebrew University of Jerusalem, 76100 Rehovot, Israel.
| | | | | | | | | |
Collapse
|
47
|
Delannoy E, Fujii S, Colas des Francs-Small C, Brundrett M, Small I. Rampant gene loss in the underground orchid Rhizanthella gardneri highlights evolutionary constraints on plastid genomes. Mol Biol Evol 2011; 28:2077-86. [PMID: 21289370 PMCID: PMC3112369 DOI: 10.1093/molbev/msr028] [Citation(s) in RCA: 170] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Since the endosymbiotic origin of chloroplasts from cyanobacteria 2 billion years ago, the evolution of plastids has been characterized by massive loss of genes. Most plants and algae depend on photosynthesis for energy and have retained ∼110 genes in their chloroplast genome that encode components of the gene expression machinery and subunits of the photosystems. However, nonphotosynthetic parasitic plants have retained a reduced plastid genome, showing that plastids have other essential functions besides photosynthesis. We sequenced the complete plastid genome of the underground orchid, Rhizanthella gardneri. This remarkable parasitic subterranean orchid possesses the smallest organelle genome yet described in land plants. With only 20 proteins, 4 rRNAs, and 9 tRNAs encoded in 59,190 bp, it is the least gene-rich plastid genome known to date apart from the fragmented plastid genome of some dinoflagellates. Despite numerous differences, striking similarities with plastid genomes from unrelated parasitic plants identify a minimal set of protein-encoding and tRNA genes required to reside in plant plastids. This prime example of convergent evolution implies shared selective constraints on gene loss or transfer.
Collapse
Affiliation(s)
- Etienne Delannoy
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Perth, Australia.
| | | | | | | | | |
Collapse
|
48
|
GREINER STEPHAN, RAUWOLF UWE, MEURER JÖRG, HERRMANN REINHOLDG. The role of plastids in plant speciation. Mol Ecol 2011; 20:671-91. [DOI: 10.1111/j.1365-294x.2010.04984.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
49
|
Walter M, Piepenburg K, Schöttler MA, Petersen K, Kahlau S, Tiller N, Drechsel O, Weingartner M, Kudla J, Bock R. Knockout of the plastid RNase E leads to defective RNA processing and chloroplast ribosome deficiency. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 64:851-63. [PMID: 21105931 DOI: 10.1111/j.1365-313x.2010.04377.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Ribonuclease E (RNase E) represents a key enzyme in bacterial RNA metabolism. It plays multifarious roles in RNA processing and also initiates degradation of mRNA by endonucleolytic cleavage. Plastids (chloroplasts) are derived from formerly free-living bacteria and have largely retained eubacterial gene expression mechanisms. Here we report the functional characterization of a chloroplast RNase E that is encoded by a single-copy nuclear gene in the model plant Arabidopsis thaliana. Analysis of knockout plants revealed that, unlike in bacteria, RNase E is not essential for survival. Absence of RNase E results in multiple defects in chloroplast RNA metabolism. Most importantly, polycistronic precursor transcripts overaccumulate in the knockout plants, while several mature monocistronic mRNAs are strongly reduced, suggesting an important function of RNase E in intercistronic processing of primary transcripts from chloroplast operons. We further show that disturbed maturation of a transcript encoding essential ribosomal proteins results in plastid ribosome deficiency and, therefore, provides a molecular explanation for the observed mutant phenotype.
Collapse
Affiliation(s)
- Michael Walter
- Institut für Botanik, Universität Münster, Schlossplatz 4, 48149 Münster, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Wang L, Ouyang M, Li Q, Zou M, Guo J, Ma J, Lu C, Zhang L. The Arabidopsis chloroplast ribosome recycling factor is essential for embryogenesis and chloroplast biogenesis. PLANT MOLECULAR BIOLOGY 2010; 74:47-59. [PMID: 20521084 DOI: 10.1007/s11103-010-9653-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Accepted: 05/19/2010] [Indexed: 05/27/2023]
Abstract
To gain insight into the functions of the nuclear-encoded factors involved in chloroplast development, we characterized the high chlorophyll fluorescence and pale green mutant 108-1 (designated as hfp108-1) of Arabidopsis thaliana. Map-based cloning revealed that the mutant contains a tandem repeat of part of the sequence (including 116 nucleotides from 631 to 746 bp downstream of the ATG) of At3g63190, which encodes a chloroplast ribosome recycling factor homologue and was named AtcpRRF. The chloroplasts of hfp108-1 plants contain few internal thylakoid membranes and are severely defective in the accumulation of chloroplast-encoded proteins. In vivo labeling experiments showed a drastic decrease in the synthesis of the chloroplast-encoded proteins, which may be attributed primarily to reduced translation of the corresponding mRNA molecules. The level of the HFP108 transcript was greatly reduced in hfp108-1, so hfp108-1 showed a weak phenotype, and null alleles of HFP108 (hfp108-2) were embryonic lethal. Observations with cleared seeds in the same silique showed that homozygous hfp108-2 seeds were blocked at the heart stage and did not develop further. Thus, these results suggest that AtcpRRF is essential for embryogenesis and chloroplast biogenesis.
Collapse
Affiliation(s)
- Liyuan Wang
- Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | | | | | | | | | | | | | | |
Collapse
|