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do Prado PFV, Ahrens FM, Liebers M, Ditz N, Braun HP, Pfannschmidt T, Hillen HS. Structure of the multi-subunit chloroplast RNA polymerase. Mol Cell 2024; 84:910-925.e5. [PMID: 38428434 DOI: 10.1016/j.molcel.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 01/26/2024] [Accepted: 02/06/2024] [Indexed: 03/03/2024]
Abstract
Chloroplasts contain a dedicated genome that encodes subunits of the photosynthesis machinery. Transcription of photosynthesis genes is predominantly carried out by a plastid-encoded RNA polymerase (PEP), a nearly 1 MDa complex composed of core subunits with homology to eubacterial RNA polymerases (RNAPs) and at least 12 additional chloroplast-specific PEP-associated proteins (PAPs). However, the architecture of this complex and the functions of the PAPs remain unknown. Here, we report the cryo-EM structure of a 19-subunit PEP complex from Sinapis alba (white mustard). The structure reveals that the PEP core resembles prokaryotic and nuclear RNAPs but contains chloroplast-specific features that mediate interactions with the PAPs. The PAPs are unrelated to known transcription factors and arrange around the core in a unique fashion. Their structures suggest potential functions during transcription in the chemical environment of chloroplasts. These results reveal structural insights into chloroplast transcription and provide a framework for understanding photosynthesis gene expression.
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Affiliation(s)
- Paula F V do Prado
- University Medical Center Göttingen, Department of Cellular Biochemistry, Humboldtallee 23, 37073 Göttingen, Germany; Max Planck Institute for Multidisciplinary Sciences, Research Group Structure and Function of Molecular Machines, Am Fassberg 11, 37077 Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany
| | - Frederik M Ahrens
- Institute of Botany, Plant Physiology, Leibniz University Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany
| | - Monique Liebers
- Institute of Botany, Plant Physiology, Leibniz University Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany
| | - Noah Ditz
- Institute of Plant Genetics, Plant Molecular Biology and Plant Proteomics, Leibniz University Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany
| | - Hans-Peter Braun
- Institute of Plant Genetics, Plant Molecular Biology and Plant Proteomics, Leibniz University Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany
| | - Thomas Pfannschmidt
- Institute of Botany, Plant Physiology, Leibniz University Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany.
| | - Hauke S Hillen
- University Medical Center Göttingen, Department of Cellular Biochemistry, Humboldtallee 23, 37073 Göttingen, Germany; Max Planck Institute for Multidisciplinary Sciences, Research Group Structure and Function of Molecular Machines, Am Fassberg 11, 37077 Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany; Göttingen Center for Molecular Biosciences (GZMB), Research Group Structure and Function of Molecular Machines, University of Göttingen, 37077 Göttingen, Germany.
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2
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Andrade-Marcial M, Pacheco-Arjona R, Hernández-Castellano S, Che-Aguilar L, De-la-Peña C. Transcriptome analysis reveals molecular mechanisms underlying chloroplast biogenesis in albino Agave angustifolia plantlets. PHYSIOLOGIA PLANTARUM 2024; 176:e14289. [PMID: 38606618 DOI: 10.1111/ppl.14289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 02/29/2024] [Accepted: 03/05/2024] [Indexed: 04/13/2024]
Abstract
Albino plants display partial or complete loss of photosynthetic pigments and defective thylakoid membrane development, consequently impairing plastid function and development. These distinctive attributes render albino plants excellent models for investigating chloroplast biogenesis. Despite their potential, limited exploration has been conducted regarding the molecular alterations underlying these phenotypes, extending beyond photosynthetic metabolism. In this study, we present a novel de novo transcriptome assembly of an albino somaclonal variant of Agave angustifolia Haw., which spontaneously emerged during the micropropagation of green plantlets. Additionally, RT-qPCR analysis was employed to validate the expression of genes associated with chloroplast biogenesis, and plastome copy numbers were quantified. This research aims to gain insight into the molecular disruptions affecting chloroplast development and ascertain whether the expression of critical genes involved in plastid development and differentiation is compromised in albino tissues of A. angustifolia. Our transcriptomic findings suggest that albino Agave plastids exhibit high proliferation, activation of the protein import machinery, altered transcription directed by PEP and NEP, dysregulation of plastome expression genes, reduced expression of photosynthesis-associated nuclear genes, disruption in the tetrapyrrole and carotenoid biosynthesis pathway, alterations in the plastid ribosome, and an increased number of plastome copies, among other alterations.
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Affiliation(s)
| | - Ramón Pacheco-Arjona
- Consejo Nacional de Ciencia y Tecnología- Universidad Autónoma de Yucatán, Facultad de Medicina Veterinaria y Zootecnia, Mérida, México
| | | | - Ligia Che-Aguilar
- Tecnológico Nacional de México. Instituto Tecnológico de Mérida, Mérida, Yucatán, México
| | - Clelia De-la-Peña
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, Mérida, Yucatán, México
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3
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Wu XX, Mu WH, Li F, Sun SY, Cui CJ, Kim C, Zhou F, Zhang Y. Cryo-EM structures of the plant plastid-encoded RNA polymerase. Cell 2024; 187:1127-1144.e21. [PMID: 38428393 DOI: 10.1016/j.cell.2024.01.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/12/2023] [Accepted: 01/16/2024] [Indexed: 03/03/2024]
Abstract
Chloroplasts are green plastids in the cytoplasm of eukaryotic algae and plants responsible for photosynthesis. The plastid-encoded RNA polymerase (PEP) plays an essential role during chloroplast biogenesis from proplastids and functions as the predominant RNA polymerase in mature chloroplasts. The PEP-centered transcription apparatus comprises a bacterial-origin PEP core and more than a dozen eukaryotic-origin PEP-associated proteins (PAPs) encoded in the nucleus. Here, we determined the cryo-EM structures of Nicotiana tabacum (tobacco) PEP-PAP apoenzyme and PEP-PAP transcription elongation complexes at near-atomic resolutions. Our data show the PEP core adopts a typical fold as bacterial RNAP. Fifteen PAPs bind at the periphery of the PEP core, facilitate assembling the PEP-PAP supercomplex, protect the complex from oxidation damage, and likely couple gene transcription with RNA processing. Our results report the high-resolution architecture of the chloroplast transcription apparatus and provide the structural basis for the mechanistic and functional study of transcription regulation in chloroplasts.
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Affiliation(s)
- Xiao-Xian Wu
- Key Laboratory of Synthetic Biology, Key Laboratory of Plant Design, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Wen-Hui Mu
- Key Laboratory of Synthetic Biology, Key Laboratory of Plant Design, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Fan Li
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Shu-Yi Sun
- Key Laboratory of Synthetic Biology, Key Laboratory of Plant Design, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chao-Jun Cui
- University of Chinese Academy of Sciences, Beijing 100049, China; Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Chanhong Kim
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Fei Zhou
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China.
| | - Yu Zhang
- Key Laboratory of Synthetic Biology, Key Laboratory of Plant Design, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.
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4
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Zhang Y, Tian L, Lu C. Chloroplast gene expression: Recent advances and perspectives. PLANT COMMUNICATIONS 2023; 4:100611. [PMID: 37147800 PMCID: PMC10504595 DOI: 10.1016/j.xplc.2023.100611] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 04/11/2023] [Accepted: 05/01/2023] [Indexed: 05/07/2023]
Abstract
Chloroplasts evolved from an ancient cyanobacterial endosymbiont more than 1.5 billion years ago. During subsequent coevolution with the nuclear genome, the chloroplast genome has remained independent, albeit strongly reduced, with its own transcriptional machinery and distinct features, such as chloroplast-specific innovations in gene expression and complicated post-transcriptional processing. Light activates the expression of chloroplast genes via mechanisms that optimize photosynthesis, minimize photodamage, and prioritize energy investments. Over the past few years, studies have moved from describing phases of chloroplast gene expression to exploring the underlying mechanisms. In this review, we focus on recent advances and emerging principles that govern chloroplast gene expression in land plants. We discuss engineering of pentatricopeptide repeat proteins and its biotechnological effects on chloroplast RNA research; new techniques for characterizing the molecular mechanisms of chloroplast gene expression; and important aspects of chloroplast gene expression for improving crop yield and stress tolerance. We also discuss biological and mechanistic questions that remain to be answered in the future.
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Affiliation(s)
- Yi Zhang
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Lin Tian
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Congming Lu
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China.
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5
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Jiang HW, Peng KC, Hsu TY, Chiou YC, Hsieh HL. Arabidopsis FIN219/JAR1 interacts with phytochrome a under far-red light and jasmonates in regulating hypocotyl elongation via a functional demand manner. PLoS Genet 2023; 19:e1010779. [PMID: 37216398 DOI: 10.1371/journal.pgen.1010779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 05/09/2023] [Indexed: 05/24/2023] Open
Abstract
Integration of light and phytohormones is essential for plant growth and development. FAR-RED INSENSITIVE 219 (FIN219)/JASMONATE RESISTANT 1 (JAR1) participates in phytochrome A (phyA)-mediated far-red (FR) light signaling in Arabidopsis and is a jasmonate (JA)-conjugating enzyme for the generation of an active JA-isoleucine. Accumulating evidence indicates that FR and JA signaling integrate with each other. However, the molecular mechanisms underlying their interaction remain largely unknown. Here, the phyA mutant was hypersensitive to JA. The double mutant fin219-2phyA-211 showed a synergistic effect on seedling development under FR light. Further evidence revealed that FIN219 and phyA antagonized with each other in a mutually functional demand to modulate hypocotyl elongation and expression of light- and JA-responsive genes. Moreover, FIN219 interacted with phyA under prolonged FR light, and MeJA could enhance their interaction with CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) in the dark and FR light. FIN219 and phyA interaction occurred mainly in the cytoplasm, and they regulated their mutual subcellular localization under FR light. Surprisingly, the fin219-2 mutant abolished the formation of phyA nuclear bodies under FR light. Overall, these data identified a vital mechanism of phyA-FIN219-COP1 association in response to FR light, and MeJA may allow the photoactivated phyA to trigger photomorphogenic responses.
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Affiliation(s)
- Han-Wei Jiang
- Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Kai-Chun Peng
- Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Ting-Yu Hsu
- Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Yen-Chang Chiou
- Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Hsu-Liang Hsieh
- Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei, Taiwan
- Department of Life Science, College of Life Science, National Taiwan University, Taipei, Taiwan
- Master Program in Global Agriculture Technology and Genomic Science, National Taiwan University, Taipei, Taiwan
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6
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Huang C, Liu D, Li ZA, Molloy DP, Luo ZF, Su Y, Li HO, Liu Q, Wang RZ, Xiao LT. The PPR protein RARE1-mediated editing of chloroplast accD transcripts is required for fatty acid biosynthesis and heat tolerance in Arabidopsis. PLANT COMMUNICATIONS 2023; 4:100461. [PMID: 36221851 PMCID: PMC9860180 DOI: 10.1016/j.xplc.2022.100461] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 09/12/2022] [Accepted: 10/10/2022] [Indexed: 06/01/2023]
Abstract
It has been reported that Arabidopsis chloroplast accD transcripts undergo RNA editing and that loss of accD-C794 RNA editing does not affect plant growth under normal conditions. To date, the exact biological role of accD-C794 editing has remained elusive. Here, we reveal an unexpected role for accD-C794 editing in response to heat stress. Loss of accD-C794 editing results in a yellow and dwarf phenotype with decreased chloroplast gene expression under heat stress, and artificial improvement of C794-edited accD gene expression enhances heat tolerance in Arabidopsis. These data suggest that accD-C794 editing confers heat tolerance in planta. We also found that treatment with the product of acetyl coenzyme A carboxylase (ACCase) could allay mutant phenotypic characteristics and showed that a mutation in the CAC3 gene for the α-subunit of ACCase was associated with dwarfism under heat stress. These observations indicate that defective accD-C794 editing may be intrinsic to reduced ACCase activity, thereby contributing to heat sensitivity. ACCase catalyzes the committed step of de novo fatty acid (FA) biosynthesis. FA content analysis revealed that unsaturated oleic (C18:1) and linoleic acids (C18:2) were low in the accD-C794 editing-defective mutant but high in the C794-edited accD-overexpressing plants compared with the wild type. Supplying exogenous C18:1 and C18:2 could rescue the mutant phenotype, suggesting that these FAs play an essential role in tolerance to heat stress. Transmission electron microscopy observations showed that heat stress seriously affected the membrane architecture in accD editing-defective mutants but not in accD-overexpressing plants. These results provide the first evidence that accD-C794 editing regulates FA biosynthesis for maintenance of membrane structural homeostasis under heat stress.
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Affiliation(s)
- Chao Huang
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Dan Liu
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Zi-Ang Li
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - David P Molloy
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Chongqing Medical University, Chongqing 400016, China
| | - Zhou-Fei Luo
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Yi Su
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Hai-Ou Li
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Qing Liu
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Ruo-Zhong Wang
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Lang-Tao Xiao
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China.
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7
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Kendrick R, Chotewutmontri P, Belcher S, Barkan A. Correlated retrograde and developmental regulons implicate multiple retrograde signals as coordinators of chloroplast development in maize. THE PLANT CELL 2022; 34:4897-4919. [PMID: 36073948 PMCID: PMC9709983 DOI: 10.1093/plcell/koac276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 09/02/2022] [Indexed: 05/09/2023]
Abstract
Signals emanating from chloroplasts influence nuclear gene expression, but roles of retrograde signals during chloroplast development are unclear. To address this gap, we analyzed transcriptomes of non-photosynthetic maize mutants and compared them to transcriptomes of stages of normal leaf development. The transcriptomes of two albino mutants lacking plastid ribosomes resembled transcriptomes at very early stages of normal leaf development, whereas the transcriptomes of two chlorotic mutants with thylakoid targeting or plastid transcription defects resembled those at a slightly later stage. We identified ∼2,700 differentially expressed genes, which fall into six major categories based on the polarity and mutant-specificity of the change. Downregulated genes were generally expressed late in normal development and were enriched in photosynthesis genes, whereas upregulated genes act early and were enriched for functions in chloroplast biogenesis and cytosolic translation. We showed further that target-of-rapamycin (TOR) signaling was elevated in mutants lacking plastid ribosomes and declined in concert with plastid ribosome buildup during normal leaf development. Our results implicate three plastid signals as coordinators of photosynthetic differentiation. One signal requires plastid ribosomes and activates photosynthesis genes. A second signal reflects attainment of chloroplast maturity and represses chloroplast biogenesis genes. A third signal, the consumption of nutrients by developing chloroplasts, represses TOR, promoting termination of cell proliferation during leaf development.
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Affiliation(s)
- Rennie Kendrick
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403, USA
| | | | - Susan Belcher
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403, USA
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403, USA
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8
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Liebers M, Cozzi C, Uecker F, Chambon L, Blanvillain R, Pfannschmidt T. Biogenic signals from plastids and their role in chloroplast development. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:7105-7125. [PMID: 36002302 DOI: 10.1093/jxb/erac344] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
Plant seeds do not contain differentiated chloroplasts. Upon germination, the seedlings thus need to gain photoautotrophy before storage energies are depleted. This requires the coordinated expression of photosynthesis genes encoded in nuclear and plastid genomes. Chloroplast biogenesis needs to be additionally coordinated with the light regulation network that controls seedling development. This coordination is achieved by nucleus to plastid signals called anterograde and plastid to nucleus signals termed retrograde. Retrograde signals sent from plastids during initial chloroplast biogenesis are also called biogenic signals. They have been recognized as highly important for proper chloroplast biogenesis and for seedling development. The molecular nature, transport, targets, and signalling function of biogenic signals are, however, under debate. Several studies disproved the involvement of a number of key components that were at the base of initial models of retrograde signalling. New models now propose major roles for a functional feedback between plastid and cytosolic protein homeostasis in signalling plastid dysfunction as well as the action of dually localized nucleo-plastidic proteins that coordinate chloroplast biogenesis with light-dependent control of seedling development. This review provides a survey of the developments in this research field, summarizes the unsolved questions, highlights several recent advances, and discusses potential new working modes.
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Affiliation(s)
- Monique Liebers
- Gottfried-Wilhelm-Leibniz-Universität Hannover, Naturwissenschaftliche Fakultät, Institut für Botanik, Pflanzenphysiologie, Herrenhäuser Str. 2, D-30419 Hannover, Germany
| | - Carolina Cozzi
- Gottfried-Wilhelm-Leibniz-Universität Hannover, Naturwissenschaftliche Fakultät, Institut für Botanik, Pflanzenphysiologie, Herrenhäuser Str. 2, D-30419 Hannover, Germany
| | - Finia Uecker
- Gottfried-Wilhelm-Leibniz-Universität Hannover, Naturwissenschaftliche Fakultät, Institut für Botanik, Pflanzenphysiologie, Herrenhäuser Str. 2, D-30419 Hannover, Germany
| | - Louise Chambon
- Université Grenoble-Alpes, CNRS, CEA, INRA, IRIG-LPCV, F-38000 Grenoble, France
| | - Robert Blanvillain
- Université Grenoble-Alpes, CNRS, CEA, INRA, IRIG-LPCV, F-38000 Grenoble, France
| | - Thomas Pfannschmidt
- Gottfried-Wilhelm-Leibniz-Universität Hannover, Naturwissenschaftliche Fakultät, Institut für Botanik, Pflanzenphysiologie, Herrenhäuser Str. 2, D-30419 Hannover, Germany
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9
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Park HS, Jeon JH, Cho W, Lee Y, Park JY, Kim J, Park YS, Koo HJ, Kang JH, Lee TJ, Kim SH, Kim JB, Kwon HY, Kim SH, Paek NC, Jang G, Suh JY, Yang TJ. High-throughput discovery of plastid genes causing albino phenotypes in ornamental chimeric plants. HORTICULTURE RESEARCH 2022; 10:uhac246. [PMID: 36643742 PMCID: PMC9832966 DOI: 10.1093/hr/uhac246] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 10/26/2022] [Indexed: 06/17/2023]
Abstract
Chimeric plants composed of green and albino tissues have great ornamental value. To unveil the functional genes responsible for albino phenotypes in chimeric plants, we inspected the complete plastid genomes (plastomes) in green and albino leaf tissues from 23 ornamental chimeric plants belonging to 20 species, including monocots, dicots, and gymnosperms. In nine chimeric plants, plastomes were identical between green and albino tissues. Meanwhile, another 14 chimeric plants were heteroplasmic, showing a mutation between green and albino tissues. We identified 14 different point mutations in eight functional plastid genes related to plastid-encoded RNA polymerase (rpo) or photosystems which caused albinism in the chimeric plants. Among them, 12 were deleterious mutations in the target genes, in which early termination appeared due to small deletion-mediated frameshift or single nucleotide substitution. Another was single nucleotide substitution in an intron of the ycf3 and the other was a missense mutation in coding region of the rpoC2 gene. We inspected chlorophyll structure, protein functional model of the rpoC2, and expression levels of the related genes in green and albino tissues of Reynoutria japonica. A single amino acid change, histidine-to-proline substitution, in the rpoC2 protein may destabilize the peripheral helix of plastid-encoded RNA polymerase, impairing the biosynthesis of the photosynthesis system in the albino tissue of R. japonica chimera plant.
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Affiliation(s)
| | | | | | | | - Jee Young Park
- Department of Agriculture, Forestry and Bioresources, Research Institute of Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jiseok Kim
- Department of Agriculture, Forestry and Bioresources, Research Institute of Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Young Sang Park
- Department of Agriculture, Forestry and Bioresources, Research Institute of Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Hyun Jo Koo
- Department of Agriculture, Forestry and Bioresources, Research Institute of Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jung Hwa Kang
- Hantaek Botanical Garden, Yongin, Gyeonggi-do, 17183, Republic of Korea
| | - Taek Joo Lee
- Hantaek Botanical Garden, Yongin, Gyeonggi-do, 17183, Republic of Korea
| | - Sang Hoon Kim
- Radiation Breeding Research Team, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 56212, Korea
| | - Jin-Baek Kim
- Radiation Breeding Research Team, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 56212, Korea
| | - Hae-Yun Kwon
- Special Forest Resources Division, National Institute of Forest Science, Suwon 16631, Korea
| | - Suk-Hwan Kim
- Department of Agriculture, Forestry and Bioresources, Research Institute of Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Nam-Chon Paek
- Department of Agriculture, Forestry and Bioresources, Research Institute of Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Geupil Jang
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, South Korea
| | - Jeong-Yong Suh
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea
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10
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Barrero-Gil J, Bouza-Morcillo L, Espinosa-Cores L, Piñeiro M, Jarillo JA. H4 acetylation by the NuA4 complex is required for plastid transcription and chloroplast biogenesis. NATURE PLANTS 2022; 8:1052-1063. [PMID: 36038656 DOI: 10.1038/s41477-022-01229-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Chloroplast biogenesis is crucial in plant development, as it is essential for the transition to autotrophic growth. This process is light-induced and relies on the orchestrated transcription of nuclear and plastid genes, enabling the effective assembly and regulation of the photosynthetic machinery. Here we reveal a new regulation level for this process by showing the involvement of chromatin remodelling in the nuclear control of plastid gene expression for proper chloroplast biogenesis and function. The two Arabidopsis homologues of yeast EPL1 protein, components of the NuA4 histone acetyltransferase complex, are essential for plastid transcription and correct chloroplast development and performance. We show that EPL1 proteins are light-regulated and necessary for concerted expression of nuclear genes encoding most components of chloroplast transcriptional machinery, directly mediating H4K5ac deposition at these loci and promoting the expression of plastid genes required for chloroplast biogenesis. These data unveil a NuA4-mediated mechanism regulating chloroplast biogenesis that links the transcription of nuclear and plastid genomes during chloroplast development.
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Affiliation(s)
- Javier Barrero-Gil
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)/CSIC, Campus Montegancedo UPM, Pozuelo de Alarcón (Madrid), Madrid, Spain
| | - Laura Bouza-Morcillo
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)/CSIC, Campus Montegancedo UPM, Pozuelo de Alarcón (Madrid), Madrid, Spain
| | - Loreto Espinosa-Cores
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)/CSIC, Campus Montegancedo UPM, Pozuelo de Alarcón (Madrid), Madrid, Spain
| | - Manuel Piñeiro
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)/CSIC, Campus Montegancedo UPM, Pozuelo de Alarcón (Madrid), Madrid, Spain.
| | - José A Jarillo
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)/CSIC, Campus Montegancedo UPM, Pozuelo de Alarcón (Madrid), Madrid, Spain.
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11
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Three-Dimensional Envelope and Subunit Interactions of the Plastid-Encoded RNA Polymerase from Sinapis alba. Int J Mol Sci 2022; 23:ijms23179922. [PMID: 36077319 PMCID: PMC9456514 DOI: 10.3390/ijms23179922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 11/16/2022] Open
Abstract
RNA polymerases (RNAPs) are found in all living organisms. In the chloroplasts, the plastid-encoded RNA polymerase (PEP) is a prokaryotic-type multimeric RNAP involved in the selective transcription of the plastid genome. One of its active states requires the assembly of nuclear-encoded PEP-Associated Proteins (PAPs) on the catalytic core, producing a complex of more than 900 kDa, regarded as essential for chloroplast biogenesis. In this study, sequence alignments of the catalytic core subunits across various chloroplasts of the green lineage and prokaryotes combined with structural data show that variations are observed at the surface of the core, whereas internal amino acids associated with the catalytic activity are conserved. A purification procedure compatible with a structural analysis was used to enrich the native PEP from Sinapis alba chloroplasts. A mass spectrometry (MS)-based proteomic analysis revealed the core components, the PAPs and additional proteins, such as FLN2 and pTAC18. MS coupled with crosslinking (XL-MS) provided the initial structural information in the form of protein clusters, highlighting the relative position of some subunits with the surfaces of their interactions. Using negative stain electron microscopy, the PEP three-dimensional envelope was calculated. Particles classification shows that the protrusions are very well-conserved, offering a framework for the future positioning of all the PAPs. Overall, the results show that PEP-associated proteins are firmly and specifically associated with the catalytic core, giving to the plastid transcriptional complex a singular structure compared to other RNAPs.
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12
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Fujii S, Kobayashi K, Lin YC, Liu YC, Nakamura Y, Wada H. Impacts of phosphatidylglycerol on plastid gene expression and light induction of nuclear photosynthetic genes. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2952-2970. [PMID: 35560187 DOI: 10.1093/jxb/erac034] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 01/31/2022] [Indexed: 06/15/2023]
Abstract
Phosphatidylglycerol (PG) is the only major phospholipid in the thylakoid membrane of chloroplasts. PG is essential for photosynthesis, and loss of PG in Arabidopsis thaliana results in severe defects of growth and chloroplast development, with decreased chlorophyll accumulation, impaired thylakoid formation, and down-regulation of photosynthesis-associated genes encoded in nuclear and plastid genomes. However, how the absence of PG affects gene expression and plant growth remains unclear. To elucidate this mechanism, we investigated transcriptional profiles of a PG-deficient Arabidopsis mutant pgp1-2 under various light conditions. Microarray analysis demonstrated that reactive oxygen species (ROS)-responsive genes were up-regulated in pgp1-2. However, ROS production was not enhanced in the mutant even under strong light, indicating limited impacts of photooxidative stress on the defects of pgp1-2. Illumination to dark-adapted pgp1-2 triggered down-regulation of photosynthesis-associated nuclear-encoded genes (PhANGs), while plastid-encoded genes were constantly suppressed. Overexpression of GOLDEN2-LIKE1 (GLK1), a transcription factor gene regulating chloroplast development, in pgp1-2 up-regulated PhANGs but not plastid-encoded genes along with chlorophyll accumulation. Our data suggest a broad impact of PG biosynthesis on nuclear-encoded genes partially via GLK1 and a specific involvement of this lipid in plastid gene expression and plant development.
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Affiliation(s)
- Sho Fujii
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, Japan
- Department of Botany, Graduate School of Science, Kyoto University, Kita-Shirakawa Oiwake-cho, Sakyo-ku, Kyoto, Japan
| | - Koichi Kobayashi
- Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuencho, Naka-ku, Sakai, Osaka, Japan
- Faculty of Liberal Arts and Sciences, Osaka Prefecture University, 1-1 Gakuencho, Naka-ku, Sakai, Osaka, Japan
| | - Ying-Chen Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Yu-Chi Liu
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Yuki Nakamura
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
- RIKEN Center for Sustainable Resource Science (CSRS), Yokohama, Japan
| | - Hajime Wada
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, Japan
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13
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PAP8/pTAC6 Is Part of a Nuclear Protein Complex and Displays RNA Recognition Motifs of Viral Origin. Int J Mol Sci 2022; 23:ijms23063059. [PMID: 35328480 PMCID: PMC8954402 DOI: 10.3390/ijms23063059] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/09/2022] [Accepted: 03/09/2022] [Indexed: 12/13/2022] Open
Abstract
Chloroplast biogenesis depends on a complex transcriptional program involving coordinated expression of plastid and nuclear genes. In particular, photosynthesis-associated plastid genes are expressed by the plastid-encoded polymerase (PEP) that undergoes a structural rearrangement during chloroplast formation. The prokaryotic-type core enzyme is rebuilt into a larger complex by the addition of nuclear-encoded PEP-associated proteins (PAP1 to PAP12). Among the PAPs, some have been detected in the nucleus (PAP5 and PAP8), where they could serve a nuclear function required for efficient chloroplast biogenesis. Here, we detected PAP8 in a large nuclear subcomplex that may include other subunits of the plastid-encoded RNA polymerase. We have made use of PAP8 recombinant proteins in Arabidopsis thaliana to decouple its nucleus- and chloroplast-associated functions and found hypomorphic mutants pointing at essential amino acids. While the origin of the PAP8 gene remained elusive, we have found in its sequence a micro-homologous domain located within a large structural homology with a rhinoviral RNA-dependent RNA polymerase, highlighting potential RNA recognition motifs in PAP8. PAP8 in vitro RNA binding activity suggests that this domain is functional. Hence, we propose that the acquisition of PAPs may have occurred during evolution by different routes, including lateral gene transfer.
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14
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Yang C, Yan W, Chang H, Sun C. Arabidopsis CIA2 and CIL have distinct and overlapping functions in regulating chloroplast and flower development. PLANT DIRECT 2022; 6:e380. [PMID: 35106435 PMCID: PMC8786619 DOI: 10.1002/pld3.380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/14/2021] [Accepted: 12/26/2021] [Indexed: 05/05/2023]
Abstract
Arabidopsis CHLOROPLAST IMPORT APPARATUS 2 (CIA2) and its paralogous protein CIA2-LIKE (CIL) are nuclear transcription factors containing a C-terminal CCT motif. CIA2 promotes the expression of nuclear genes encoding chloroplast-localized translocons and ribosomal proteins, thereby increasing the efficiency of protein import and synthesis in chloroplasts. We have previously reported that CIA2 and CIL form a homodimer or heterodimer through their C-terminal sequences and interact with other nuclear proteins, such as CONSTANS (CO), via their N-terminal sequences, but the function of CIL had remained unclear. In this study, we verified through transgenic cia2 mutant plants expressing the CIL coding sequence that CIL is partially functionally redundant to CIA2 during vegetative growth. We also compared phenotypes and gene expression profiles of wildtype Col-0, cia2, cil, and cia2/cil mutants. Our results indicate that CIA2 and CIL coordinate chloroplast biogenesis and function mainly by upregulating the expression of the nuclear factor GOLDEN2-LIKE 1 (GLK1) and chloroplast transcription-, translation-, protein import-, and photosynthesis-related genes, with CIA2 playing a more crucial role. Furthermore, we compared flowering phenotypes in single, double, and triple mutant plants of co, cia2, and cil. We found that CIA2 and CIL participate in modulating long-day floral development. Notably, CIA2 increases flower number and height of the inflorescence main axis, whereas CIL promotes flowering.
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Affiliation(s)
- Chun‐Yen Yang
- Department of Life SciencesNational Taiwan Normal UniversityTaipeiTaiwan
| | - Wen‐You Yan
- Department of Life SciencesNational Taiwan Normal UniversityTaipeiTaiwan
| | - Hsin‐Yen Chang
- Department of Life SciencesNational Taiwan Normal UniversityTaipeiTaiwan
| | - Chih‐Wen Sun
- Department of Life SciencesNational Taiwan Normal UniversityTaipeiTaiwan
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15
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Yang Z, Liu M, Ding S, Zhang Y, Yang H, Wen X, Chi W, Lu C, Lu Q. Plastid Deficient 1 Is Essential for the Accumulation of Plastid-Encoded RNA Polymerase Core Subunit β and Chloroplast Development in Arabidopsis. Int J Mol Sci 2021; 22:ijms222413648. [PMID: 34948448 PMCID: PMC8705867 DOI: 10.3390/ijms222413648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/13/2021] [Accepted: 12/16/2021] [Indexed: 12/05/2022] Open
Abstract
Plastid-encoded RNA polymerase (PEP)-dependent transcription is an essential process for chloroplast development and plant growth. It is a complex event that is regulated by numerous nuclear-encoded proteins. In order to elucidate the complex regulation mechanism of PEP activity, identification and characterization of PEP activity regulation factors are needed. Here, we characterize Plastid Deficient 1 (PD1) as a novel regulator for PEP-dependent gene expression and chloroplast development in Arabidopsis. The PD1 gene encodes a protein that is conserved in photoautotrophic organisms. The Arabidopsis pd1 mutant showed albino and seedling-lethal phenotypes. The plastid development in the pd1 mutant was arrested. The PD1 protein localized in the chloroplasts, and it colocalized with nucleoid protein TRXz. RT-quantitative real-time PCR, northern blot, and run-on analyses indicated that the PEP-dependent transcription in the pd1 mutant was dramatically impaired, whereas the nuclear-encoded RNA polymerase-dependent transcription was up-regulated. The yeast two-hybrid assays and coimmunoprecipitation experiments showed that the PD1 protein interacts with PEP core subunit β (PEP-β), which has been verified to be essential for chloroplast development. The immunoblot analysis indicated that the accumulation of PEP-β was barely detected in the pd1 mutant, whereas the accumulation of the other essential components of the PEP complex, such as core subunits α and β′, were not affected in the pd1 mutant. These observations suggested that the PD1 protein is essential for the accumulation of PEP-β and chloroplast development in Arabidopsis, potentially by direct interaction with PEP-β.
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Affiliation(s)
- Zhipan Yang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Z.Y.); (M.L.); (S.D.); (H.Y.); (X.W.); (W.C.)
| | - Mingxin Liu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Z.Y.); (M.L.); (S.D.); (H.Y.); (X.W.); (W.C.)
- College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shunhua Ding
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Z.Y.); (M.L.); (S.D.); (H.Y.); (X.W.); (W.C.)
| | - Yi Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China;
| | - Huixia Yang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Z.Y.); (M.L.); (S.D.); (H.Y.); (X.W.); (W.C.)
| | - Xiaogang Wen
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Z.Y.); (M.L.); (S.D.); (H.Y.); (X.W.); (W.C.)
| | - Wei Chi
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Z.Y.); (M.L.); (S.D.); (H.Y.); (X.W.); (W.C.)
| | - Congming Lu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China;
- Correspondence: (C.L.); (Q.L.)
| | - Qingtao Lu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Z.Y.); (M.L.); (S.D.); (H.Y.); (X.W.); (W.C.)
- College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (C.L.); (Q.L.)
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16
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Kong M, Wu Y, Wang Z, Qu W, Lan Y, Chen X, Liu Y, Shahnaz P, Yang Z, Yu Q, Mi H. A Novel Chloroplast Protein RNA Processing 8 Is Required for the Expression of Chloroplast Genes and Chloroplast Development in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2021; 12:700975. [PMID: 34956248 PMCID: PMC8695849 DOI: 10.3389/fpls.2021.700975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 11/03/2021] [Indexed: 06/14/2023]
Abstract
Chloroplast development involves the coordinated expression of both plastids- and nuclear-encoded genes in higher plants. However, the underlying mechanism still remains largely unknown. In this study, we isolated and characterized an Arabidopsis mutant with an albino lethality phenotype named RNA processing 8 (rp8). Genetic complementation analysis demonstrated that the gene AT4G37920 (RP8) was responsible for the mutated phenotype. The RP8 gene was strongly expressed in photosynthetic tissues at both transcription and translation protein levels. The RP8 protein is localized in the chloroplast and associated with the thylakoid. Disruption of the RP8 gene led to a defect in the accumulation of the rpoA mature transcript, which reduced the level of the RpoA protein, and affected the transcription of PEP-dependent genes. The abundance of the chloroplast rRNA, including 23S, 16S, 4.5S, and 5S rRNA, were reduced in the rp8 mutant, respectively, and the amounts of chloroplast ribosome proteins, such as, PRPS1(uS1c), PRPS5(uS5c), PRPL2 (uL2c), and PRPL4 (uL4c), were substantially decreased in the rp8 mutant, which indicated that knockout of RP8 seriously affected chloroplast translational machinery. Accordingly, the accumulation of photosynthetic proteins was seriously reduced. Taken together, these results indicate that the RP8 protein plays an important regulatory role in the rpoA transcript processing, which is required for the expression of chloroplast genes and chloroplast development in Arabidopsis.
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Affiliation(s)
- Mengmeng Kong
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Yaozong Wu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Ziyuan Wang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Wantong Qu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Yixin Lan
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Xin Chen
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Yanyun Liu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Perveen Shahnaz
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Zhongnan Yang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Qingbo Yu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Hualing Mi
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
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17
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Osterbaan LJ, Hoyle V, Curtis M, DeBlasio S, Rivera KD, Heck M, Fuchs M. Identification of protein interactions of grapevine fanleaf virus RNA-dependent RNA polymerase during infection of Nicotiana benthamiana by affinity purification and tandem mass spectrometry. J Gen Virol 2021; 102:001607. [PMID: 34043500 PMCID: PMC8295916 DOI: 10.1099/jgv.0.001607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 05/07/2021] [Indexed: 11/24/2022] Open
Abstract
The RNA-dependent RNA polymerase (1EPol) is involved in replication of grapevine fanleaf virus (GFLV, Nepovirus, Secoviridae) and causes vein clearing symptoms in Nicotiana benthamiana. Information on protein 1EPol interaction with other viral and host proteins is scarce. To study protein 1EPol biology, three GFLV infectious clones, i.e. GHu (a symptomatic wild-type strain), GHu-1EK802G (an asymptomatic GHu mutant) and F13 (an asymptomatic wild-type strain), were engineered with protein 1EPol fused to a V5 epitope tag at the C-terminus. Following Agrobacterium tumefaciens-mediated delivery of GFLV clones in N. benthamiana and protein extraction at seven dpi, when optimal 1EPol:V5 accumulation was detected, two viral and six plant putative interaction partners of V5-tagged protein 1EPol were identified for the three GFLV clones by affinity purification and tandem mass spectrometry. This study provides insights into the protein interactome of 1EPol during GFLV systemic infection in N. benthamiana and lays the foundation for validation work.
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Affiliation(s)
- Larissa J. Osterbaan
- Cornell University, Plant Pathology and Plant Microbe-Biology Section, School of Integrative Plant Science, Cornell AgriTech at the New York State Agricultural Experiment Station, Geneva, NY 14456, USA
- Present address: Department of Biology, Utica College, Utica, NY 13502, USA
| | - Victoria Hoyle
- Cornell University, Plant Pathology and Plant Microbe-Biology Section, School of Integrative Plant Science, Cornell AgriTech at the New York State Agricultural Experiment Station, Geneva, NY 14456, USA
| | - Michelle Curtis
- Cornell University, Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Ithaca, NY 14853, USA
| | - Stacy DeBlasio
- Emerging Pests and Pathogens Research Unit, USDA Agricultural Research Service, Robert W. Holley Center for Agriculture and Health, Ithaca, NY 14853, USA
| | - Keith D. Rivera
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
- Present address: The Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
| | - Michelle Heck
- Cornell University, Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Ithaca, NY 14853, USA
- Emerging Pests and Pathogens Research Unit, USDA Agricultural Research Service, Robert W. Holley Center for Agriculture and Health, Ithaca, NY 14853, USA
| | - Marc Fuchs
- Cornell University, Plant Pathology and Plant Microbe-Biology Section, School of Integrative Plant Science, Cornell AgriTech at the New York State Agricultural Experiment Station, Geneva, NY 14456, USA
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18
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Favier A, Gans P, Boeri Erba E, Signor L, Muthukumar SS, Pfannschmidt T, Blanvillain R, Cobessi D. The Plastid-Encoded RNA Polymerase-Associated Protein PAP9 Is a Superoxide Dismutase With Unusual Structural Features. FRONTIERS IN PLANT SCIENCE 2021; 12:668897. [PMID: 34276730 PMCID: PMC8278866 DOI: 10.3389/fpls.2021.668897] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 05/28/2021] [Indexed: 05/09/2023]
Abstract
In Angiosperms, the plastid-encoded RNA polymerase (PEP) is a multimeric enzyme, essential for the proper expression of the plastid genome during chloroplast biogenesis. It is especially required for the light initiated expression of photosynthesis genes and the subsequent build-up of the photosynthetic apparatus. The PEP complex is composed of a prokaryotic-type core of four plastid-encoded subunits and 12 nuclear-encoded PEP-associated proteins (PAPs). Among them, there are two iron superoxide dismutases, FSD2/PAP9 and FSD3/PAP4. Superoxide dismutases usually are soluble enzymes not bound into larger protein complexes. To investigate this unusual feature, we characterized PAP9 using molecular genetics, fluorescence microscopy, mass spectrometry, X-ray diffraction, and solution-state NMR. Despite the presence of a predicted nuclear localization signal within the sequence of the predicted chloroplast transit peptide, PAP9 was mainly observed within plastids. Mass spectrometry experiments with the recombinant Arabidopsis PAP9 suggested that monomers and dimers of PAP9 could be associated to the PEP complex. In crystals, PAP9 occurred as a dimeric enzyme that displayed a similar fold to that of the FeSODs or manganese SOD (MnSODs). A zinc ion, instead of the expected iron, was found to be penta-coordinated with a trigonal-bipyramidal geometry in the catalytic center of the recombinant protein. The metal coordination involves a water molecule and highly conserved residues in FeSODs. Solution-state NMR and DOSY experiments revealed an unfolded C-terminal 34 amino-acid stretch in the stand-alone protein and few internal residues interacting with the rest of the protein. We hypothesize that this C-terminal extension had appeared during evolution as a distinct feature of the FSD2/PAP9 targeting it to the PEP complex. Close vicinity to the transcriptional apparatus may allow for the protection against the strongly oxidizing aerial environment during plant conquering of terrestrial habitats.
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Affiliation(s)
- Adrien Favier
- Université Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | - Pierre Gans
- Université Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | | | - Luca Signor
- Université Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | | | | | - Robert Blanvillain
- Université Grenoble-Alpes, CNRS, CEA, INRA, IRIG-LPCV, Grenoble, France
- *Correspondence: Robert Blanvillain,
| | - David Cobessi
- Université Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
- David Cobessi,
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19
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Liebers M, Gillet FX, Israel A, Pounot K, Chambon L, Chieb M, Chevalier F, Ruedas R, Favier A, Gans P, Boeri Erba E, Cobessi D, Pfannschmidt T, Blanvillain R. Nucleo-plastidic PAP8/pTAC6 couples chloroplast formation with photomorphogenesis. EMBO J 2020; 39:e104941. [PMID: 33001465 DOI: 10.15252/embj.2020104941] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 09/02/2020] [Accepted: 09/09/2020] [Indexed: 12/29/2022] Open
Abstract
The initial greening of angiosperms involves light activation of photoreceptors that trigger photomorphogenesis, followed by the development of chloroplasts. In these semi-autonomous organelles, construction of the photosynthetic apparatus depends on the coordination of nuclear and plastid gene expression. Here, we show that the expression of PAP8, an essential subunit of the plastid-encoded RNA polymerase (PEP) in Arabidopsis thaliana, is under the control of a regulatory element recognized by the photomorphogenic factor HY5. PAP8 protein is localized and active in both plastids and the nucleus, and particularly required for the formation of late photobodies. In the pap8 albino mutant, phytochrome-mediated signalling is altered, degradation of the chloroplast development repressors PIF1/PIF3 is disrupted, HY5 is not stabilized, and the expression of the photomorphogenesis regulator GLK1 is impaired. PAP8 translocates into plastids via its targeting pre-sequence, interacts with the PEP and eventually reaches the nucleus, where it can interact with another PEP subunit pTAC12/HMR/PAP5. Since PAP8 is required for the phytochrome B-mediated signalling cascade and the reshaping of the PEP activity, it may coordinate nuclear gene expression with PEP-driven chloroplastic gene expression during chloroplast biogenesis.
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Affiliation(s)
- Monique Liebers
- CNRS, CEA, INRA, IRIG-LPCV, Univ. Grenoble-Alpes, Grenoble, France
| | | | - Abir Israel
- CNRS, CEA, INRA, IRIG-LPCV, Univ. Grenoble-Alpes, Grenoble, France
| | - Kevin Pounot
- CNRS, CEA, INRA, IRIG-LPCV, Univ. Grenoble-Alpes, Grenoble, France
| | - Louise Chambon
- CNRS, CEA, INRA, IRIG-LPCV, Univ. Grenoble-Alpes, Grenoble, France
| | - Maha Chieb
- CNRS, CEA, INRA, IRIG-LPCV, Univ. Grenoble-Alpes, Grenoble, France
| | - Fabien Chevalier
- CNRS, CEA, INRA, IRIG-LPCV, Univ. Grenoble-Alpes, Grenoble, France
| | - Rémi Ruedas
- CEA, CNRS, IBS, Univ. Grenoble Alpes, Grenoble, France
| | - Adrien Favier
- CEA, CNRS, IBS, Univ. Grenoble Alpes, Grenoble, France
| | - Pierre Gans
- CEA, CNRS, IBS, Univ. Grenoble Alpes, Grenoble, France
| | | | - David Cobessi
- CEA, CNRS, IBS, Univ. Grenoble Alpes, Grenoble, France
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20
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Tadini L, Jeran N, Peracchio C, Masiero S, Colombo M, Pesaresi P. The plastid transcription machinery and its coordination with the expression of nuclear genome: Plastid-Encoded Polymerase, Nuclear-Encoded Polymerase and the Genomes Uncoupled 1-mediated retrograde communication. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190399. [PMID: 32362266 DOI: 10.1098/rstb.2019.0399] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Plastid genes in higher plants are transcribed by at least two different RNA polymerases, the plastid-encoded RNA polymerase (PEP), a bacteria-like core enzyme whose subunits are encoded by plastid genes (rpoA, rpoB, rpoC1 and rpoC2), and the nuclear-encoded plastid RNA polymerase (NEP), a monomeric bacteriophage-type RNA polymerase. Both PEP and NEP enzymes are active in non-green plastids and in chloroplasts at all developmental stages. Their transcriptional activity is affected by endogenous and exogenous factors and requires a strict coordination within the plastid and with the nuclear gene expression machinery. This review focuses on the different molecular mechanisms underlying chloroplast transcription regulation and its coordination with the photosynthesis-associated nuclear genes (PhANGs) expression. Particular attention is given to the link between NEP and PEP activity and the GUN1- (Genomes Uncoupled 1) mediated chloroplast-to-nucleus retrograde communication with respect to the Δrpo adaptive response, i.e. the increased accumulation of NEP-dependent transcripts upon depletion of PEP activity, and the editing-level changes observed in NEP-dependent transcripts, including rpoB and rpoC1, in gun1 cotyledons after norflurazon or lincomycin treatment. The role of cytosolic preproteins and HSP90 chaperone as components of the GUN1-retrograde signalling pathway, when chloroplast biogenesis is inhibited in Arabidopsis cotyledons, is also discussed. This article is part of the theme issue 'Retrograde signalling from endosymbiotic organelles'.
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Affiliation(s)
- Luca Tadini
- Dipartimento di Bioscienze, Università degli studi di Milano, 20133 Milano, Italy
| | - Nicolaj Jeran
- Dipartimento di Bioscienze, Università degli studi di Milano, 20133 Milano, Italy
| | - Carlotta Peracchio
- Dipartimento di Bioscienze, Università degli studi di Milano, 20133 Milano, Italy
| | - Simona Masiero
- Dipartimento di Bioscienze, Università degli studi di Milano, 20133 Milano, Italy
| | - Monica Colombo
- Centro Ricerca e Innovazione, Fondazione Edmund Mach, 38010 San Michele all'Adige, Italy
| | - Paolo Pesaresi
- Dipartimento di Bioscienze, Università degli studi di Milano, 20133 Milano, Italy
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21
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Jiang D, Tang R, Shi Y, Ke X, Wang Y, Che Y, Luan S, Hou X. Arabidopsis Seedling Lethal 1 Interacting With Plastid-Encoded RNA Polymerase Complex Proteins Is Essential for Chloroplast Development. FRONTIERS IN PLANT SCIENCE 2020; 11:602782. [PMID: 33391315 PMCID: PMC7772139 DOI: 10.3389/fpls.2020.602782] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/27/2020] [Indexed: 05/16/2023]
Abstract
Mitochondrial transcription termination factors (mTERFs) are highly conserved proteins in metazoans. Plants have many more mTERF proteins than animals. The functions and the underlying mechanisms of plants' mTERFs remain largely unknown. In plants, mTERF family proteins are present in both mitochondria and plastids and are involved in gene expression in these organelles through different mechanisms. In this study, we screened Arabidopsis mutants with pigment-defective phenotypes and isolated a T-DNA insertion mutant exhibiting seedling-lethal and albino phenotypes [seedling lethal 1 (sl1)]. The SL1 gene encodes an mTERF protein localized in the chloroplast stroma. The sl1 mutant showed severe defects in chloroplast development, photosystem assembly, and the accumulation of photosynthetic proteins. Furthermore, the transcript levels of some plastid-encoded proteins were significantly reduced in the mutant, suggesting that SL1/mTERF3 may function in the chloroplast gene expression. Indeed, SL1/mTERF3 interacted with PAP12/PTAC7, PAP5/PTAC12, and PAP7/PTAC14 in the subgroup of DNA/RNA metabolism in the plastid-encoded RNA polymerase (PEP) complex. Taken together, the characterization of the plant chloroplast mTERF protein, SL1/mTERF3, that associated with PEP complex proteins provided new insights into RNA transcription in the chloroplast.
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Affiliation(s)
- Deyuan Jiang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Renjie Tang
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Yafei Shi
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xiangsheng Ke
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yetao Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yufen Che
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Sheng Luan
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
- Sheng Luan,
| | - Xin Hou
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
- *Correspondence: Xin Hou,
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22
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Xiong HB, Wang J, Huang C, Rochaix JD, Lin FM, Zhang JX, Ye LS, Shi XH, Yu QB, Yang ZN. mTERF8, a Member of the Mitochondrial Transcription Termination Factor Family, Is Involved in the Transcription Termination of Chloroplast Gene psbJ. PLANT PHYSIOLOGY 2020; 182:408-423. [PMID: 31685645 PMCID: PMC6945865 DOI: 10.1104/pp.19.00906] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 10/21/2019] [Indexed: 05/28/2023]
Abstract
Members of the mitochondrial transcription terminator factor (mTERF) family, originally identified in vertebrate mitochondria, are involved in the termination of organellular transcription. In plants, mTERF proteins are mainly localized in chloroplasts and mitochondria. In Arabidopsis (Arabidopsis thaliana), mTERF8/pTAC15 was identified in the plastid-encoded RNA polymerase (PEP) complex, the major RNA polymerase of chloroplasts. In this work, we demonstrate that mTERF8 is associated with the PEP complex. An mTERF8 knockout line displayed a wild-type-like phenotype under standard growth conditions, but showed impaired efficiency of photosystem II electron flow. Transcription of most chloroplast genes was not substantially affected in the mterf8 mutant; however, the level of the psbJ transcript from the psbEFLJ polycistron was increased. RNA blot analysis showed that a larger transcript accumulates in mterf8 than in the wild type. Thus, abnormal transcription and/or RNA processing occur for the psbEFLJ polycistron. Circular reverse transcription PCR and sequence analysis showed that the psbJ transcript terminates 95 nucleotides downstream of the translation stop codon in the wild type, whereas its termination is aberrant in mterf8 Both electrophoresis mobility shift assays and chloroplast chromatin immunoprecipitation analysis showed that mTERF8 specifically binds to the 3' terminal region of psbJ Transcription analysis using the in vitro T7 RNA polymerase system showed that mTERF8 terminates psbJ transcription. Together, these results suggest that mTERF8 is specifically involved in the transcription termination of the chloroplast gene psbJ.
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Affiliation(s)
- Hai-Bo Xiong
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Jing Wang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Chao Huang
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China
| | - Jean-David Rochaix
- Departments of Molecular Biology and Plant Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Fei-Min Lin
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Jia-Xing Zhang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Lin-Shan Ye
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Xiao-He Shi
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Qing-Bo Yu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Zhong-Nan Yang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
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23
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Lee S, Joung YH, Kim JK, Do Choi Y, Jang G. An isoform of the plastid RNA polymerase-associated protein FSD3 negatively regulates chloroplast development. BMC PLANT BIOLOGY 2019; 19:524. [PMID: 31775615 PMCID: PMC6882211 DOI: 10.1186/s12870-019-2128-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 11/08/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Plastid-encoded RNA polymerase (PEP) plays an essential role in chloroplast development by governing the expression of genes involved in photosynthesis. At least 12 PEP-associated proteins (PAPs), including FSD3/PAP4, regulate PEP activity and chloroplast development by modulating formation of the PEP complex. RESULTS In this study, we identified FSD3S, a splicing variant of FSD3; the FSD3 and FSD3S transcripts encode proteins with identical N-termini, but different C-termini. Characterization of FSD3 and FSD3S proteins showed that the C-terminal region of FSD3S contains a transmembrane domain, which promotes FSD3S localization to the chloroplast membrane but not to nucleoids, in contrast to FSD3, which localizes to the chloroplast nucleoid. We also found that overexpression of FSD3S negatively affects photosynthetic activity and chloroplast development by reducing expression of genes involved in photosynthesis. In addition, FSD3S failed to complement the chloroplast developmental defects in the fsd3 mutant. CONCLUSION These results suggest FSD3 and FSD3S, with their distinct localization patterns, have different functions in chloroplast development, and FSD3S negatively regulates expression of PEP-dependent chloroplast genes, and development of chloroplasts.
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Affiliation(s)
- Sangyool Lee
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, 61186 Republic of Korea
| | - Young Hee Joung
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, 61186 Republic of Korea
| | - Ju-Kon Kim
- Graduate School of International Agricultural Technology and Crop Biotechnology Institute/Green BioScience and Technology, Seoul National University, Pyeongchang, 25354 Republic of Korea
| | - Yang Do Choi
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826 Republic of Korea
- The National Academy of Sciences, Seoul, 06579 Republic of Korea
| | - Geupil Jang
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, 61186 Republic of Korea
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24
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Ding S, Zhang Y, Hu Z, Huang X, Zhang B, Lu Q, Wen X, Wang Y, Lu C. mTERF5 Acts as a Transcriptional Pausing Factor to Positively Regulate Transcription of Chloroplast psbEFLJ. MOLECULAR PLANT 2019; 12:1259-1277. [PMID: 31128276 DOI: 10.1016/j.molp.2019.05.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 04/22/2019] [Accepted: 05/16/2019] [Indexed: 05/21/2023]
Abstract
RNA polymerase transcriptional pausing represents a major checkpoint in transcription in bacteria and metazoans, but it is unknown whether this phenomenon occurs in plant organelles. Here, we report that transcriptional pausing occurs in chloroplasts. We found that mTERF5 specifically and positively regulates the transcription of chloroplast psbEFLJ in Arabidopsis thaliana that encodes four key subunits of photosystem II. We found that mTERF5 causes the plastid-encoded RNA polymerase (PEP) complex to pause at psbEFLJ by binding to the +30 to +51 region of double-stranded DNA. Moreover, we revealed that mTERF5 interacts with pTAC6, an essential subunit of the PEP complex, although pTAC6 is not involved in the transcriptional pausing at psbEFLJ. We showed that mTERF5 recruits additional pTAC6 to the transcriptionally paused region of psbEFLJ, and the recruited pTAC6 proteins could be assembled into the PEP complex to regulate psbEFLJ transcription. Taken together, our findings shed light on the role of transcriptional pausing in chloroplast transcription in plants.
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Affiliation(s)
- Shunhua Ding
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Yi Zhang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhi Hu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiahe Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bohan Zhang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingtao Lu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Xiaogang Wen
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Yingchun Wang
- 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
| | - Congming Lu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China.
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25
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Zhang S, Zhang H, Xia Y, Xiong L. The caseinolytic protease complex component CLPC1 in Arabidopsis maintains proteome and RNA homeostasis in chloroplasts. BMC PLANT BIOLOGY 2018; 18:192. [PMID: 30208840 PMCID: PMC6136230 DOI: 10.1186/s12870-018-1396-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 08/27/2018] [Indexed: 05/18/2023]
Abstract
BACKGROUND Homeostasis of the proteome is critical to the development of chloroplasts and also affects the expression of certain nuclear genes. CLPC1 facilitates the translocation of chloroplast pre-proteins and mediates protein degradation. RESULTS We found that proteins involved in photosynthesis are dramatically decreased in their abundance in the clpc1 mutant, whereas many proteins involved in chloroplast transcription and translation were increased in the mutant. Expression of the full-length CLPC1 protein, but not of the N-terminus-deleted CLPC1 (ΔN), in the clpc1 mutant background restored the normal levels of most of these proteins. Interestingly, the ΔN complementation line could also restore some proteins affected by the mutation to normal levels. We also found that that the clpc1 mutation profoundly affects transcript levels of chloroplast genes. Sense transcripts of many chloroplast genes are up-regulated in the clpc1 mutant. The level of SVR7, a PPR protein, was affected by the clpc1 mutation. We showed that SVR7 might be a target of CLPC1 as CLPC1-SVR7 interaction was detected through co-immunoprecipitation. CONCLUSION Our study indicates that in addition to its role in maintaining proteome homeostasis, CLPC1 and likely the CLP proteasome complex also play a role in transcriptome homeostasis through its functions in maintaining proteome homeostasis.
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Affiliation(s)
- Shoudong Zhang
- Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Saudi Arabia
- Centre for Soybean Research, Partner State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, Special Administrative Region China
| | - Huoming Zhang
- Core labs, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Saudi Arabia
| | - Yiji Xia
- Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
- Partner State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Shatin, Hong Kong SAR, China
- Partner State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Shatin, Hong Kong, SAR, China
| | - Liming Xiong
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Saudi Arabia
- Texas A&M AgriLife Research Center, Dallas, TX 75252 USA
- Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843 USA
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26
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Inomata T, Baslam M, Masui T, Koshu T, Takamatsu T, Kaneko K, Pozueta-Romero J, Mitsui T. Proteomics Analysis Reveals Non-Controlled Activation of Photosynthesis and Protein Synthesis in a Rice npp1 Mutant under High Temperature and Elevated CO₂ Conditions. Int J Mol Sci 2018; 19:ijms19092655. [PMID: 30205448 PMCID: PMC6165220 DOI: 10.3390/ijms19092655] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 08/30/2018] [Accepted: 09/03/2018] [Indexed: 11/26/2022] Open
Abstract
Rice nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1) catalyzes the hydrolytic breakdown of the pyrophosphate and phosphodiester bonds of a number of nucleotides including ADP-glucose and ATP. Under high temperature and elevated CO2 conditions (HT + ECO2), the npp1 knockout rice mutant displayed rapid growth and high starch content phenotypes, indicating that NPP1 exerts a negative effect on starch accumulation and growth. To gain further insight into the mechanisms involved in the NPP1 downregulation induced starch overaccumulation, in this study we conducted photosynthesis, leaf proteomic, and chloroplast phosphoproteomic analyses of wild-type (WT) and npp1 plants cultured under HT + ECO2. Photosynthesis in npp1 leaves was significantly higher than in WT. Additionally, npp1 leaves accumulated higher levels of sucrose than WT. The proteomic analyses revealed upregulation of proteins related to carbohydrate metabolism and the protein synthesis system in npp1 plants. Further, our data indicate the induction of 14-3-3 proteins in npp1 plants. Our finding demonstrates a higher level of protein phosphorylation in npp1 chloroplasts, which may play an important role in carbohydrate accumulation. Together, these results offer novel targets and provide additional insights into carbohydrate metabolism regulation under ambient and adverse conditions.
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Affiliation(s)
- Takuya Inomata
- Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Niigata 950-2181, Japan.
| | - Marouane Baslam
- Department of Biochemistry, Niigata University, Niigata 950-218, Japan.
| | - Takahiro Masui
- Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Niigata 950-2181, Japan.
| | - Tsutomu Koshu
- Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Niigata 950-2181, Japan.
| | - Takeshi Takamatsu
- Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Niigata 950-2181, Japan.
- Department of Biochemistry, Niigata University, Niigata 950-218, Japan.
| | - Kentaro Kaneko
- Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Niigata 950-2181, Japan.
| | - Javier Pozueta-Romero
- Instituto de Agrobiotecnología (CSIC, UPNA, Gobierno de Navarra), Mutiloako Etorbidea Zenbaki Gabe, 31192 Mutiloabeti, Nafarroa, Spain.
| | - Toshiaki Mitsui
- Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Niigata 950-2181, Japan.
- Department of Biochemistry, Niigata University, Niigata 950-218, Japan.
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27
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Liebers M, Chevalier F, Blanvillain R, Pfannschmidt T. PAP genes are tissue- and cell-specific markers of chloroplast development. PLANTA 2018; 248:629-646. [PMID: 29855700 DOI: 10.1007/s00425-018-2924-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 05/21/2018] [Indexed: 05/03/2023]
Abstract
Expression of PAP genes is strongly coordinated and represents a highly selective cell-specific marker associated with the development of chloroplasts in photosynthetically active organs of Arabidopsis seedlings and adult plants. Transcription in plastids of plants depends on the activity of phage-type single-subunit nuclear-encoded RNA polymerases (NEP) and a prokaryotic multi-subunit plastid-encoded RNA polymerase (PEP). PEP is comprised of the core subunits α, β, β' and β″ encoded by rpoA, rpoB/C1/C2 genes located on the plastome. This core enzyme needs to interact with nuclear-encoded sigma factors for proper promoter recognition. In chloroplasts, the core enzyme is surrounded by additional 12 nuclear-encoded subunits, all of eukaryotic origin. These PEP-associated proteins (PAPs) were found to be essential for chloroplast biogenesis as Arabidopsis inactivation mutants for each of them revealed albino or pale-green phenotypes. In silico analysis of transcriptomic data suggests that PAP genes represent a tightly controlled regulon, whereas wetlab data are sparse and correspond to the expression of individual genes mostly studied at the seedling stage. Using RT-PCR, transient, and stable expression assays of PAP promoter-GUS-constructs, we do provide, in this study, a comprehensive expression catalogue for PAP genes throughout the life cycle of Arabidopsis. We demonstrate a selective impact of light on PAP gene expression and uncover a high tissue specificity that is coupled to developmental progression especially during the transition from skotomorphogenesis to photomorphogenesis. Our data imply that PAP gene expression precedes the formation of chloroplasts rendering PAP genes a tissue- and cell-specific marker of chloroplast biogenesis.
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Affiliation(s)
- Monique Liebers
- LPCV, CEA, CNRS, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France
| | - Fabien Chevalier
- LPCV, CEA, CNRS, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France
| | - Robert Blanvillain
- LPCV, CEA, CNRS, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France.
| | - Thomas Pfannschmidt
- LPCV, CEA, CNRS, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France.
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28
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Serre NBC, Alban C, Bourguignon J, Ravanel S. An outlook on lysine methylation of non-histone proteins in plants. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:4569-4581. [PMID: 29931361 DOI: 10.1093/jxb/ery231] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Protein methylation is a very diverse, widespread, and important post-translational modification affecting all aspects of cellular biology in eukaryotes. Methylation on the side-chain of lysine residues in histones has received considerable attention due to its major role in determining chromatin structure and the epigenetic regulation of gene expression. Over the last 20 years, lysine methylation of non-histone proteins has been recognized as a very common modification that contributes to the fine-tuned regulation of protein function. In plants, our knowledge in this field is much more fragmentary than in yeast and animal cells. In this review, we describe the plant enzymes involved in the methylation of non-histone substrates, and we consider historical and recent advances in the identification of non-histone lysine-methylated proteins in photosynthetic organisms. Finally, we discuss our current knowledge about the role of protein lysine methylation in regulating molecular and cellular functions in plants, and consider challenges for future research.
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Affiliation(s)
- Nelson B C Serre
- Univ. Grenoble Alpes, INRA, CEA, CNRS, BIG, PCV, Grenoble, France
| | - Claude Alban
- Univ. Grenoble Alpes, INRA, CEA, CNRS, BIG, PCV, Grenoble, France
| | | | - Stéphane Ravanel
- Univ. Grenoble Alpes, INRA, CEA, CNRS, BIG, PCV, Grenoble, France
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29
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Zhang Y, Cui YL, Zhang XL, Yu QB, Wang X, Yuan XB, Qin XM, He XF, Huang C, Yang ZN. A nuclear-encoded protein, mTERF6, mediates transcription termination of rpoA polycistron for plastid-encoded RNA polymerase-dependent chloroplast gene expression and chloroplast development. Sci Rep 2018; 8:11929. [PMID: 30093718 PMCID: PMC6085346 DOI: 10.1038/s41598-018-30166-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 04/20/2018] [Indexed: 12/13/2022] Open
Abstract
The expression of plastid genes is regulated by two types of DNA-dependent RNA polymerases, plastid-encoded RNA polymerase (PEP) and nuclear-encoded RNA polymerase (NEP). The plastid rpoA polycistron encodes a series of essential chloroplast ribosome subunits and a core subunit of PEP. Despite the functional importance, little is known about the regulation of rpoA polycistron. In this work, we show that mTERF6 directly associates with a 3′-end sequence of rpoA polycistron in vitro and in vivo, and that absence of mTERF6 promotes read-through transcription at this site, indicating that mTERF6 acts as a factor required for termination of plastid genes’ transcription in vivo. In addition, the transcriptions of some essential ribosome subunits encoded by rpoA polycistron and PEP-dependent plastid genes are reduced in the mterf6 knockout mutant. RpoA, a PEP core subunit, accumulates to about 50% that of the wild type in the mutant, where early chloroplast development is impaired. Overall, our functional analyses of mTERF6 provide evidence that it is more likely a factor required for transcription termination of rpoA polycistron, which is essential for chloroplast gene expression and chloroplast development.
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Affiliation(s)
- Yi Zhang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China.,Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Yong-Lan Cui
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Xiao-Lei Zhang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Qing-Bo Yu
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Xi Wang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Xin-Bo Yuan
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Xue-Mei Qin
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Xiao-Fang He
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Chao Huang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Zhong-Nan Yang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China.
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30
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Yu QB, Zhao TT, Ye LS, Cheng L, Wu YQ, Huang C, Yang ZN. pTAC10, an S1-domain-containing component of the transcriptionally active chromosome complex, is essential for plastid gene expression in Arabidopsis thaliana and is phosphorylated by chloroplast-targeted casein kinase II. PHOTOSYNTHESIS RESEARCH 2018; 137:69-83. [PMID: 29330702 DOI: 10.1007/s11120-018-0479-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 12/28/2017] [Indexed: 06/07/2023]
Abstract
In higher plant chloroplasts, the plastid-encoded RNA polymerase (PEP) consists of four catalytic subunits and numerous nuclear-encoded accessory proteins, including pTAC10, an S1-domain-containing protein. In this study, pTAC10 knockout lines were characterized. Two ptac10 mutants had an albino phenotype and severely impaired chloroplast development. The pTAC10 genomic sequence fused to a four-tandem MYC tag driven by its own promoter functionally complemented the ptac10-1 mutant phenotype. pTAC10 was present in both the chloroplast stroma and thylakoids. Two-dimensional blue native polyacrylamide gel electrophoresis (BN-PAGE), and immunoblotting assays showed that pTAC10:MYC co-migrates with one of the PEP core subunits, RpoB. A comprehensive investigation of the plastid gene expression profiles by quantitative RT-PCR revealed that, compared with wild-type plants, the abundance of PEP-dependent plastid transcripts is severely decreased in the ptac10-1 mutant, while the amount of plastid transcripts exclusively transcribed by NEP either barely changes or even increases. RNA blot analysis confirmed that PEP-dependent chloroplast transcripts, including psaB, psbA and rbcL, substantially decrease in the ptac10-1 mutant. Immunoblotting showed reduced accumulation of most chloroplast proteins in the ptac10 mutants. These data indicate the essential role of pTAC10 in plastid gene expression and plastid development. pTAC10 interacts with chloroplast-targeted casein kinase 2 (cpCK2) in vitro and in vivo and can be phosphorylated by Arabidopsis cpCK2 in vitro at sites Ser95, Ser396 and Ser434. RNA-EMSA assays showed that pTAC10 is able to bind to the psbA, atpE and accD transcripts, suggesting a non-specific RNA-binding activity of pTAC10. The RNA affinity of pTAC10 was enhanced by phosphorylation and decreased by the amino acid substitution Ser434-Ala of pTAC10. These data show that pTAC10 is essential for plastid gene expression in Arabidopsis and that it can be phosphorylated by cpCK2.
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Affiliation(s)
- Qing-Bo Yu
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Tuan-Tuan Zhao
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Lin-Shan Ye
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Ling Cheng
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Ying-Qian Wu
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Chao Huang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Zhong-Nan Yang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, China.
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31
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Fishman L, Sweigart AL. When Two Rights Make a Wrong: The Evolutionary Genetics of Plant Hybrid Incompatibilities. ANNUAL REVIEW OF PLANT BIOLOGY 2018; 69:707-731. [PMID: 29505737 DOI: 10.1146/annurev-arplant-042817-040113] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Hybrids between flowering plant species often exhibit reduced fitness, including sterility and inviability. Such hybrid incompatibilities create barriers to genetic exchange that can promote reproductive isolation between diverging populations and, ultimately, speciation. Additionally, hybrid breakdown opens a window into hidden molecular and evolutionary processes occurring within species. Here, we review recent work on the mechanisms and origins of hybrid incompatibility in flowering plants, including both diverse genic interactions and chromosomal incompatibilities. Conflict and coevolution among and within plant genomes contributes to the evolution of some well-characterized genic incompatibilities, but duplication and drift also play important roles. Inversions, while contributing to speciation by suppressing recombination, rarely cause underdominant sterility. Translocations cause severe F1 sterility by disrupting meiosis in heterozygotes, making their fixation in outcrossing sister species a paradox. Evolutionary genomic analyses of both genic and chromosomal incompatibilities, in the context of population genetic theory, can explicitly test alternative scenarios for their origins.
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Affiliation(s)
- Lila Fishman
- Division of Biological Sciences, University of Montana, Missoula, Montana 59812, USA;
| | - Andrea L Sweigart
- Department of Genetics, University of Georgia, Athens, Georgia 30602, USA;
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32
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Zuellig MP, Sweigart AL. Gene duplicates cause hybrid lethality between sympatric species of Mimulus. PLoS Genet 2018; 14:e1007130. [PMID: 29649209 PMCID: PMC5896889 DOI: 10.1371/journal.pgen.1007130] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 11/27/2017] [Indexed: 01/30/2023] Open
Abstract
Hybrid incompatibilities play a critical role in the evolution and maintenance of species. We have discovered a simple genetic incompatibility that causes lethality in hybrids between two closely related species of yellow monkeyflower (Mimulus guttatus and M. nasutus). This hybrid incompatibility, which causes one sixteenth of F2 hybrid seedlings to lack chlorophyll and die shortly after germination, occurs between sympatric populations that are connected by ongoing interspecific gene flow. Using complimentary genetic mapping and gene expression analyses, we show that lethality occurs in hybrids that lack a functional copy of the critical photosynthetic gene pTAC14. In M. guttatus, this gene was duplicated, but the ancestral copy is no longer expressed. In M. nasutus, the duplication is missing altogether. As a result, hybrids die when they are homozygous for the nonfunctional M. guttatus copy and missing the duplicate from M. nasutus, apparently due to misregulated transcription of key photosynthetic genes. Our study indicates that neutral evolutionary processes may play an important role in the evolution of hybrid incompatibilities and opens the door to direct investigations of their contribution to reproductive isolation among naturally hybridizing species. The evolution of hybrid incompatibilities (gene interactions that cause hybrids to be sterile or inviable) is a common outcome of genomic divergence between lineages. However, evaluating the importance of hybrid incompatibilities for speciation requires that we identify the causal genes and evolutionary forces in recently diverged, wild species. We discovered that hybrid seedling lethality between two closely related sister species of yellow monkeyflower is caused by duplicate copies of a gene critical for chloroplast development. Because each lineage carries its one functional gene copy in a distinct genomic location, some hybrids inherit only inactive (or missing) alleles. We infer that hybrid lethality in this young species pair has arisen through divergent resolution of gene duplicates by degenerative mutations and (likely) genetic drift. These findings are an important step toward understanding the evolutionary dynamics of hybrid incompatibility genes in nature, as well as the role of such genes in species divergence.
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Affiliation(s)
- Matthew P. Zuellig
- Department of Genetics, University of Georgia, Athens, Georgia, United States of America
- * E-mail:
| | - Andrea L. Sweigart
- Department of Genetics, University of Georgia, Athens, Georgia, United States of America
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Affiliation(s)
- Yaniv Brandvain
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Daniel R. Matute
- Biology Department, University of North Carolina, Chapel Hill, North Carolina, United States of America
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Lin D, Zheng K, Liu Z, Li Z, Teng S, Xu J, Dong Y. Rice TCM1 Encoding a Component of the TAC Complex is Required for Chloroplast Development under Cold Stress. THE PLANT GENOME 2018; 11:160065. [PMID: 29505628 DOI: 10.3835/plantgenome2016.07.0065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Transcriptionally active chromosome (TAC) is a component of protein-DNA complexes with RNA polymerase activity, expressed in the plastid. However, the function of rice TAC proteins is still poorly understood. In this paper, we first report the identification of a new rice ( L.) mutant () in the gene encoding TAC. The mutant displayed an albino phenotype and malformed chloroplasts before the three-leaf stage when grown at low temperatures (20°C) and a normal phenotype at higher temperatures (>28°C). Map-based cloning revealed that encodes a novel chloroplast-targeted TAC protein in rice. In addition, the transcript levels of all examined plastid-encoded polymerase (PEP)-dependent genes were clearly downregulated in mutants at low temperatures, although partially recovering levels were obtained at high temperatures, comparable to wild-type plants. Furthermore, the transcripts were ubiquitously expressed in all examined tissues, with high expression levels in green tissues. The data suggest that the rice nuclear-encoded TAC protein TCM1 is essential for proper chloroplast development and maintaining PEP activity under cold stress.
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Hernández-Verdeja T, Strand Å. Retrograde Signals Navigate the Path to Chloroplast Development. PLANT PHYSIOLOGY 2018; 176:967-976. [PMID: 29254985 PMCID: PMC5813530 DOI: 10.1104/pp.17.01299] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 12/12/2017] [Indexed: 05/18/2023]
Abstract
Complex signaling networks between the chloroplast and the nucleus mediate the emergence of the seedling into the light and the establishment of photosynthesis.
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Affiliation(s)
- Tamara Hernández-Verdeja
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-901 87 Umeå, Sweden
| | - Åsa Strand
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-901 87 Umeå, Sweden
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Qiu Z, Kang S, He L, Zhao J, Zhang S, Hu J, Zeng D, Zhang G, Dong G, Gao Z, Ren D, Chen G, Guo L, Qian Q, Zhu L. The newly identified heat-stress sensitive albino 1 gene affects chloroplast development in rice. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 267:168-179. [PMID: 29362095 DOI: 10.1016/j.plantsci.2017.11.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 11/28/2017] [Accepted: 11/28/2017] [Indexed: 05/18/2023]
Abstract
High temperature, a major abiotic stress, significantly affects the yield and quality of crops in many parts of the world. Components of the photosynthetic apparatus are highly susceptible to thermal damage. Although the responses to acute heat stress have been studied intensively, the mechanisms that regulate chloroplast development under heat stress remain obscure, especially in crop plants. Here, we cloned and characterized the gene responsible for the heat-sensitive albino1 (hsa1) mutation in rice (Oryza sativa). The hsa1 mutant harbors a recessive mutation in a gene encoding fructokinase-like protein2 (FLN2); the mutation causes a premature stop codon and results in a severe albino phenotype, with defects in early chloroplast development. The color of hsa1 mutant plants gradually changed from albino to green at later stages of development at various temperatures and chloroplast biogenesis was strongly delayed at high temperature (32 °C). HSA1 expression was strongly reduced in hsa1 plants compared to wild type (WT). HSA1 localizes to the chloroplast and regulates chloroplast development. An HSA1 deletion mutant induced by CRISPR/Cas9 was heat sensitive but had a faster greening phenotype than the original hsa1 allele at all temperatures. RNA and protein levels of plastid-encoded RNA polymerase-dependent plastid genes were markedly reduced in hsa1 plants compared to WT. These results demonstrated that HSA1 plays important roles in chloroplast development at early stages, and functions in protecting chloroplasts under heat stress at later stages in rice.
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Affiliation(s)
- Zhennan Qiu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Shujing Kang
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Lei He
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Juan Zhao
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Sen Zhang
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Jiang Hu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Dali Zeng
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Guangheng Zhang
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Guojun Dong
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Zhenyu Gao
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Deyong Ren
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Guang Chen
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Longbiao Guo
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Qian Qian
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China.
| | - Li Zhu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China.
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Moreno JC, Martínez-Jaime S, Schwartzmann J, Karcher D, Tillich M, Graf A, Bock R. Temporal Proteomics of Inducible RNAi Lines of Clp Protease Subunits Identifies Putative Protease Substrates. PLANT PHYSIOLOGY 2018; 176:1485-1508. [PMID: 29229697 PMCID: PMC5813558 DOI: 10.1104/pp.17.01635] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 12/07/2017] [Indexed: 05/20/2023]
Abstract
The Clp protease in the chloroplasts of plant cells is a large complex composed of at least 13 nucleus-encoded subunits and one plastid-encoded subunit, which are arranged in several ring-like structures. The proteolytic P-ring and the structurally similar R-ring form the core complex that contains the proteolytic chamber. Chaperones of the HSP100 family help with substrate unfolding, and additional accessory proteins are believed to assist with Clp complex assembly and/or to promote complex stability. Although the structure and function of the Clp protease have been studied in great detail in both bacteria and chloroplasts, the identification of bona fide protease substrates has been very challenging. Knockout mutants of genes for protease subunits are of limited value, due to their often pleiotropic phenotypes and the difficulties with distinguishing primary effects (i.e. overaccumulation of proteins that represent genuine protease substrates) from secondary effects (proteins overaccumulating for other reasons). Here, we have developed a new strategy for the identification of candidate substrates of plant proteases. By combining ethanol-inducible knockdown of protease subunits with time-resolved analysis of changes in the proteome, proteins that respond immediately to reduced protease activity can be identified. In this way, secondary effects are minimized and putative protease substrates can be identified. We have applied this strategy to the Clp protease complex of tobacco (Nicotiana tabacum) and identified a set of chloroplast proteins that are likely degraded by Clp. These include several metabolic enzymes but also a small number of proteins involved in photosynthesis.
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Affiliation(s)
- Juan C Moreno
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Silvia Martínez-Jaime
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Joram Schwartzmann
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Daniel Karcher
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Michael Tillich
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Alexander Graf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
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38
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RAD4 and RAD23/HMR Contribute to Arabidopsis UV Tolerance. Genes (Basel) 2017; 9:genes9010008. [PMID: 29283431 PMCID: PMC5793161 DOI: 10.3390/genes9010008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 12/15/2017] [Accepted: 12/19/2017] [Indexed: 11/16/2022] Open
Abstract
In plants, exposure to solar ultraviolet (UV) light is unavoidable, resulting in DNA damage. Damaged DNA causes mutations, replication arrest, and cell death, thus efficient repair of the damaged DNA is essential. A light-independent DNA repair pathway called nucleotide excision repair (NER) is conserved throughout evolution. For example, the damaged DNA-binding protein Radiation sensitive 4 (Rad4) in Saccharomyces cerevisiae is homologous to the mammalian NER protein Xeroderma Pigmentosum complementation group C (XPC). In this study, we examined the role of the Arabidopsis thaliana Rad4/XPC homologue (AtRAD4) in plant UV tolerance by generating overexpression lines. AtRAD4 overexpression, both with and without an N-terminal yellow fluorescent protein (YFP) tag, resulted in increased UV tolerance. YFP-RAD4 localized to the nucleus, and UV treatment did not alter this localization. We also used yeast two-hybrid analysis to examine the interaction of AtRAD4 with Arabidopsis RAD23 and found that RAD4 interacted with RAD23B as well as with the structurally similar protein HEMERA (HMR). In addition, we found that hmr and rad23 mutants exhibited increased UV sensitivity. Thus, our analysis suggests a role for RAD4 and RAD23/HMR in plant UV tolerance.
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Ye LS, Zhang Q, Pan H, Huang C, Yang ZN, Yu QB. EMB2738, which encodes a putative plastid-targeted GTP-binding protein, is essential for embryogenesis and chloroplast development in higher plants. PHYSIOLOGIA PLANTARUM 2017; 161:414-430. [PMID: 28675462 DOI: 10.1111/ppl.12603] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 06/22/2017] [Accepted: 06/26/2017] [Indexed: 06/07/2023]
Abstract
In higher plants, chloroplasts carry out many important functions, and normal chloroplast development is required for embryogenesis. Numerous chloroplast-targeted proteins involved in embryogenesis have been identified. Nevertheless, their functions remain unclear. In this study, a chloroplast-localized protein, EMB2738, was reported to be involved in Arabidopsis embryogenesis. EMB2738 knockout led to defective embryos, and the embryo development in emb2738 was interrupted after the globular stage. Complementation experiments identified the AT3G12080 locus as EMB2738. Cellular observation indicated that severely impaired chloroplast development was observed in these aborted embryos. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis showed that chloroplast-encoded photosynthetic genes, which are transcribed by plastid-encoded RNA polymerase (PEP), are predominantly decreased in defective embryogenesis, compared with those in the wild-type. In contrast, genes encoding PEP core subunits, which are transcribed by nucleus-encoded RNA polymerase (NEP), were increased. These results suggested that the knockout of EMB2738 strongly blocked chloroplast-encoded photosynthesis gene expression in embryos. Silencing of the EMB2738 orthologue in tobacco through a virus-induced genome silencing technique resulted in an albinism phenotype, vacuolated chloroplasts and decreased PEP-dependent plastid transcription. These results suggested that NtEMB2738 might be involved in plastid gene expression. Nevertheless, genetic analysis showed that the NtEMB2738 coding sequence could not fully rescue the defective embryogenesis of the emb2738 mutant, which suggested functional divergence between NtEMB2738 and EMB2738 in embryogenesis. Taken together, these results indicated that both EMB2738 and NtEMB2738 are involved in the expression of plastid genes in higher plants, and there is a functional divergence between NtEMB2738 and EMB2738 in embryogenesis.
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Affiliation(s)
- Lin-Shan Ye
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
- College of Tourism, Shanghai Normal University, Shanghai 200234, China
| | - Qin Zhang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Hui Pan
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Chao Huang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Zhong-Nan Yang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
- College of Tourism, Shanghai Normal University, Shanghai 200234, China
| | - Qing-Bo Yu
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
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40
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Grübler B, Merendino L, Twardziok SO, Mininno M, Allorent G, Chevalier F, Liebers M, Blanvillain R, Mayer KFX, Lerbs-Mache S, Ravanel S, Pfannschmidt T. Light and Plastid Signals Regulate Different Sets of Genes in the Albino Mutant Pap7-1. PLANT PHYSIOLOGY 2017; 175:1203-1219. [PMID: 28935841 PMCID: PMC5664474 DOI: 10.1104/pp.17.00982] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 09/20/2017] [Indexed: 05/20/2023]
Abstract
Plants possessing dysfunctional plastids due to defects in pigment biosynthesis or translation are known to repress photosynthesis-associated nuclear genes via retrograde signals from the disturbed organelles toward the nucleus. These signals are thought to be essential for proper biogenesis and function of the plastid. Mutants lacking plastid-encoded RNA polymerase-associated proteins (PAPs) display a genetic arrest in eoplast-chloroplast transition leading to an albino phenotype in the light. Retrograde signaling in these mutants, therefore, could be expected to be similar as under conditions inducing plastid dysfunction. To answer this question, we performed plastome- and genomewide array analyses in the pap7-1 mutant of Arabidopsis (Arabidopsis thaliana). In parallel, we determined the potential overlap with light-regulated expression networks. To this end, we performed a comparative expression profiling approach using light- and dark-grown wild-type plants as relative control for the expression profiles obtained from light-grown pap7-1 mutants. Our data indicate a specific impact of retrograde signals on metabolism-related genes in pap7-1 mutants reflecting the starvation situation of the albino seedlings. In contrast, light regulation of PhANGs and other nuclear gene groups appears to be fully functional in this mutant, indicating that a block in chloroplast biogenesis per se does not repress expression of them as suggested by earlier studies. Only genes for light harvesting complex proteins displayed a significant repression indicating an exclusive retrograde impact on this gene family. Our results indicate that chloroplasts and arrested plastids each emit specific signals that control different target gene modules both in positive and negative manner.
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Affiliation(s)
- Björn Grübler
- LPCV, CNRS, CEA, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France and
| | - Livia Merendino
- LPCV, CNRS, CEA, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France and
| | - Sven O Twardziok
- Plant Genome and Systems Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Morgane Mininno
- LPCV, CNRS, CEA, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France and
| | - Guillaume Allorent
- LPCV, CNRS, CEA, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France and
| | - Fabien Chevalier
- LPCV, CNRS, CEA, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France and
| | - Monique Liebers
- LPCV, CNRS, CEA, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France and
| | - Robert Blanvillain
- LPCV, CNRS, CEA, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France and
| | - Klaus F X Mayer
- Plant Genome and Systems Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Silva Lerbs-Mache
- LPCV, CNRS, CEA, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France and
| | - Stéphane Ravanel
- LPCV, CNRS, CEA, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France and
| | - Thomas Pfannschmidt
- LPCV, CNRS, CEA, INRA, Université Grenoble-Alpes, BIG, 38000, Grenoble, France and
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Lehniger MK, Finster S, Melonek J, Oetke S, Krupinska K, Schmitz-Linneweber C. Global RNA association with the transcriptionally active chromosome of chloroplasts. PLANT MOLECULAR BIOLOGY 2017; 95:303-311. [PMID: 28887777 DOI: 10.1007/s11103-017-0649-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 08/07/2017] [Indexed: 06/07/2023]
Abstract
KEY MESSAGE Processed chloroplast RNAs are co-enriched with preparations of the chloroplast transcriptionally active chromosome. Chloroplast genomes are organized as a polyploid DNA-protein structure called the nucleoid. Transcriptionally active chloroplast DNA together with tightly bound protein factors can be purified by gel filtration as a functional entity called the transcriptionally active chromosome (TAC). Previous proteomics analyses of nucleoids and of TACs demonstrated a considerable overlap in protein composition including RNA binding proteins. Therefore the RNA content of TAC preparations from Nicotiana tabacum was determined using whole genome tiling arrays. A large number of chloroplast RNAs was found to be associated with the TAC. The pattern of RNAs attached to the TAC consists of RNAs produced by different chloroplast RNA polymerases and differs from the pattern of RNA found in input controls. An analysis of RNA splicing and RNA editing of selected RNA species demonstrated that TAC-associated RNAs are processed to a similar extent as the RNA in input controls. Thus, TAC fractions contain a specific subset of the processed chloroplast transcriptome.
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Affiliation(s)
- Marie-Kristin Lehniger
- Institute of Biology, Humboldt University of Berlin, Philippstr. 11-13, 10115, Berlin, Germany
| | - Sabrina Finster
- Institute of Biology, Humboldt University of Berlin, Philippstr. 11-13, 10115, Berlin, Germany
| | - Joanna Melonek
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Svenja Oetke
- Institute of Botany, Christian-Albrechts-University of Kiel, Olshausenstr. 40, 24098, Kiel, Germany
| | - Karin Krupinska
- Institute of Botany, Christian-Albrechts-University of Kiel, Olshausenstr. 40, 24098, Kiel, Germany.
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Chang SH, Lee S, Um TY, Kim JK, Do Choi Y, Jang G. pTAC10, a Key Subunit of Plastid-Encoded RNA Polymerase, Promotes Chloroplast Development. PLANT PHYSIOLOGY 2017; 174:435-449. [PMID: 28336770 PMCID: PMC5411158 DOI: 10.1104/pp.17.00248] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 03/22/2017] [Indexed: 05/09/2023]
Abstract
Regulation of photosynthetic gene expression by plastid-encoded RNA polymerase (PEP) is essential for chloroplast development. The activity of PEP largely relies on at least 12 PEP-associated proteins (PAPs) encoded in the nuclear genome of plant cells. A recent model proposed that these PAPs regulate the establishment of the PEP complex through broad PAP-PEP or PAP-PAP interactions. In this study, we identified the Arabidopsis (Arabidopsis thaliana) seedling-lethal mutant ptac10-1, which has defects in chloroplast development, and found that the mutant phenotype is caused by the suppression of PLASTID S1 RNA-BINDING DOMAIN PROTEIN (pTAC10/PAP3). Analysis of the heterozygous mutant and pTAC10-overexpressing transgenic plants indicated that the expression level of pTAC10 is tightly linked to chloroplast development. Characterization of the interaction of pTAC10 with PAPs revealed that pTAC10 interacts with other PAPs, such as FSD2, FSD3, TrxZ, pTAC7, and pTAC14, but it does not interact with PEP core enzymes, such as rpoA and rpoB. Analysis of pTAC10 interactions using truncated pTAC10 proteins showed that the pTAC10 carboxyl-terminal region downstream of the S1 domain is involved in the pTAC10-PAP interaction. Furthermore, overexpression of truncated pTAC10s lacking the C-terminal regions downstream of the S1 domain could not rescue the ptac10-1 mutant phenotype and induced an abnormal whitening phenotype in Columbia-0 plants. Our observations suggested that these pTAC10-PAP interactions are essential for the formation of the PEP complex and chloroplast development.
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Affiliation(s)
- Sun Hyun Chang
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea (S.H.C., S.L., T.Y.U., Y.D.C., G.J.); and
- Graduate School of International Agricultural Technology and Crop Biotechnology Institute/Green BioScience and Technology, Seoul National University, Pyeongchang 232-916, Korea (J.-K.K.)
| | - Sangyool Lee
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea (S.H.C., S.L., T.Y.U., Y.D.C., G.J.); and
- Graduate School of International Agricultural Technology and Crop Biotechnology Institute/Green BioScience and Technology, Seoul National University, Pyeongchang 232-916, Korea (J.-K.K.)
| | - Tae Young Um
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea (S.H.C., S.L., T.Y.U., Y.D.C., G.J.); and
- Graduate School of International Agricultural Technology and Crop Biotechnology Institute/Green BioScience and Technology, Seoul National University, Pyeongchang 232-916, Korea (J.-K.K.)
| | - Ju-Kon Kim
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea (S.H.C., S.L., T.Y.U., Y.D.C., G.J.); and
- Graduate School of International Agricultural Technology and Crop Biotechnology Institute/Green BioScience and Technology, Seoul National University, Pyeongchang 232-916, Korea (J.-K.K.)
| | - Yang Do Choi
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea (S.H.C., S.L., T.Y.U., Y.D.C., G.J.); and
- Graduate School of International Agricultural Technology and Crop Biotechnology Institute/Green BioScience and Technology, Seoul National University, Pyeongchang 232-916, Korea (J.-K.K.)
| | - Geupil Jang
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea (S.H.C., S.L., T.Y.U., Y.D.C., G.J.); and
- Graduate School of International Agricultural Technology and Crop Biotechnology Institute/Green BioScience and Technology, Seoul National University, Pyeongchang 232-916, Korea (J.-K.K.)
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Nevarez PA, Qiu Y, Inoue H, Yoo CY, Benfey PN, Schnell DJ, Chen M. Mechanism of Dual Targeting of the Phytochrome Signaling Component HEMERA/pTAC12 to Plastids and the Nucleus. PLANT PHYSIOLOGY 2017; 173:1953-1966. [PMID: 28232584 PMCID: PMC5373053 DOI: 10.1104/pp.16.00116] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 02/21/2017] [Indexed: 05/20/2023]
Abstract
HEMERA (HMR) is a nuclear and plastidial dual-targeted protein. While it functions in the nucleus as a transcriptional coactivator in phytochrome signaling to regulate a distinct set of light-responsive, growth-relevant genes, in plastids it is known as pTAC12, which associates with the plastid-encoded RNA polymerase, and is essential for inducing the plastomic photosynthetic genes and initiating chloroplast biogenesis. However, the mechanism of targeting HMR to the nucleus and plastids is still poorly understood. Here, we show that HMR can be directly imported into chloroplasts through a transit peptide residing in the N-terminal 50 amino acids. Upon cleavage of the transit peptide and additional proteolytic processing, mature HMR, which begins from Lys-58, retains its biochemical properties in phytochrome signaling. Unexpectedly, expression of mature HMR failed to rescue not only the plastidial but also the nuclear defects of the hmr mutant. This is because the predicted nuclear localization signals of HMR are nonfunctional, and therefore mature HMR is unable to accumulate in either plastids or the nucleus. Surprisingly, fusing the transit peptide of the small subunit of Rubisco with mature HMR rescues both its plastidial and nuclear localization and functions. These results, combined with the observation that the nuclear form of HMR has the same reduced molecular mass as plastidial HMR, support a retrograde protein translocation mechanism in which HMR is targeted first to plastids, processed to the mature form, and then relocated to the nucleus.
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Affiliation(s)
- P Andrew Nevarez
- Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, University of California, Riverside, California 92521 (Y.Q., C.Y., M.C.)
- Department of Biology, Duke University, Durham, North Carolina 27708 (P.A.N., Y.Q., C.Y., P.N.B., M.C.); and
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824 (H.I., D.J.S.)
| | - Yongjian Qiu
- Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, University of California, Riverside, California 92521 (Y.Q., C.Y., M.C.)
- Department of Biology, Duke University, Durham, North Carolina 27708 (P.A.N., Y.Q., C.Y., P.N.B., M.C.); and
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824 (H.I., D.J.S.)
| | - Hitoshi Inoue
- Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, University of California, Riverside, California 92521 (Y.Q., C.Y., M.C.)
- Department of Biology, Duke University, Durham, North Carolina 27708 (P.A.N., Y.Q., C.Y., P.N.B., M.C.); and
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824 (H.I., D.J.S.)
| | - Chan Yul Yoo
- Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, University of California, Riverside, California 92521 (Y.Q., C.Y., M.C.)
- Department of Biology, Duke University, Durham, North Carolina 27708 (P.A.N., Y.Q., C.Y., P.N.B., M.C.); and
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824 (H.I., D.J.S.)
| | - Philip N Benfey
- Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, University of California, Riverside, California 92521 (Y.Q., C.Y., M.C.)
- Department of Biology, Duke University, Durham, North Carolina 27708 (P.A.N., Y.Q., C.Y., P.N.B., M.C.); and
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824 (H.I., D.J.S.)
| | - Danny J Schnell
- Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, University of California, Riverside, California 92521 (Y.Q., C.Y., M.C.)
- Department of Biology, Duke University, Durham, North Carolina 27708 (P.A.N., Y.Q., C.Y., P.N.B., M.C.); and
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824 (H.I., D.J.S.)
| | - Meng Chen
- Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, University of California, Riverside, California 92521 (Y.Q., C.Y., M.C.);
- Department of Biology, Duke University, Durham, North Carolina 27708 (P.A.N., Y.Q., C.Y., P.N.B., M.C.); and
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824 (H.I., D.J.S.)
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Wang L, Wang C, Wang Y, Niu M, Ren Y, Zhou K, Zhang H, Lin Q, Wu F, Cheng Z, Wang J, Zhang X, Guo X, Jiang L, Lei C, Wang J, Zhu S, Zhao Z, Wan J. WSL3, a component of the plastid-encoded plastid RNA polymerase, is essential for early chloroplast development in rice. PLANT MOLECULAR BIOLOGY 2016; 92:581-595. [PMID: 27573887 DOI: 10.1007/s11103-016-0533-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 08/22/2016] [Indexed: 06/06/2023]
Abstract
Plastid-encoded plastid RNA polymerase (PEP), a dominant RNA polymerase in mature chloroplasts, consists of core subunits and peripheral subunits. Despite the importance of the peripheral subunits in control of PEP activity it is unclear how they interact with one another to exert physiological effects on chloroplast development and plant growth, especially in rice. Here, we report a mutant, designated wsl3 that lacks a peripheral subunit in rice. We isolated the WSL3 gene encoding an essential peripheral subunit of rice PEP complex, OsPAP1/OspTAC3 by map-based cloning, and verified its function by complementation analysis. The wsl3 mutant showed a typical expression pattern of plastid-encoded genes, suggesting that PEP activity was impaired. Using immunofluorescent labeling and immunoblotting, we found that WSL3 was localized to the chloroplast and associated with the nucleoid. In addition, we demonstrated that WSL3 interacted with PEP subunits in Y2H, BiFC and pull-down experiments. Furthermore, a cpDNA IP assay revealed that WSL3 was associated with the PEP complex during the entire transcription process. We provide evidence suggesting that WSL3 is essential for early chloroplast development by interacting with subunits of the PEP complex.
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Affiliation(s)
- Liwei Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Chunming Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Yihua Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Mei Niu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Yulong Ren
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Kunneng Zhou
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Huan Zhang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Qibing Lin
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Fuqing Wu
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Zhijun Cheng
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Jiulin Wang
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Xin Zhang
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Xiuping Guo
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Ling Jiang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Cailin Lei
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Jie Wang
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Shanshan Zhu
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Zhichao Zhao
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Jianmin Wan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China.
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Wang D, Liu H, Zhai G, Wang L, Shao J, Tao Y. OspTAC2 encodes a pentatricopeptide repeat protein and regulates rice chloroplast development. J Genet Genomics 2016; 43:601-608. [PMID: 27760723 DOI: 10.1016/j.jgg.2016.09.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 08/24/2016] [Accepted: 09/13/2016] [Indexed: 11/17/2022]
Abstract
Functional chloroplast generation depends on the precise coordination of gene expression between the plastid and the nucleus and is essential for plant growth and development. In this study, a rice (Oryza sativa) mutant that exhibited albino and seedling-lethal phenotypes was isolated from a60Co-irradiated rice population. The mutant gene was identified as an ortholog of the Arabidopsis plastid transcriptionally active chromosome protein 2 (pTAC2) gene, and the mutant strain was designated osptac2. Sequence and transcription analyses showed that OspTAC2 encodes a putative chloroplast protein consisting of 10 pentratricopeptide repeat (PPR) domains and a C-terminal small MutS-related (SMR) domain. Cytological observations via microscopy showed that the OspTAC2-green fluorescent fusion protein is localized in the chloroplasts. Transmission electron microscopy revealed that the chloroplast of the osptac2 mutant lacks an organized thylakoid membrane. The transcript levels of all investigated PEP (plastid-encoded RNA polymerase)-dependent genes were dramatically reduced in the osptac2 mutant, whereas the transcript levels of NEP (nuclear-encoded polymerase)-dependent genes were increased. These results suggest that OspTAC2 plays a critical role in chloroplast development and indicate that the molecular function of the OspTAC2 gene is conserved in rice and Arabidopsis.
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Affiliation(s)
- Dekai Wang
- Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
| | - Heqin Liu
- Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Guowei Zhai
- Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Liangsheng Wang
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853-1801, USA
| | - Jianfeng Shao
- Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Yuezhi Tao
- Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
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46
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Liu D, Li W, Cheng J. The novel protein DELAYED PALE-GREENING1 is required for early chloroplast biogenesis in Arabidopsis thaliana. Sci Rep 2016; 6:25742. [PMID: 27160321 PMCID: PMC4861969 DOI: 10.1038/srep25742] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 04/21/2016] [Indexed: 11/09/2022] Open
Abstract
Chloroplast biogenesis is one of the most important subjects in plant biology. In this study, an Arabidopsis early chloroplast biogenesis mutant with a delayed pale-greening phenotype (dpg1) was isolated from a T-DNA insertion mutant collection. Both cotyledons and true leaves of dpg1 mutants were initially albino but gradually became pale green as the plant matured. Transmission electron microscopic observations revealed that the mutant displayed a delayed proplastid-to-chloroplast transition. Sequence and transcription analyses showed that AtDPG1 encodes a putatively chloroplast-localized protein containing three predicted transmembrane helices and that its expression depends on both light and developmental status. GUS staining for AtDPG1::GUS transgenic lines showed that this gene was widely expressed throughout the plant and that higher expression levels were predominantly found in green tissues during the early stages of Arabidopsis seedling development. Furthermore, quantitative real-time RT-PCR analyses revealed that a number of chloroplast- and nuclear-encoded genes involved in chlorophyll biosynthesis, photosynthesis and chloroplast development were substantially down-regulated in the dpg1 mutant. These data indicate that AtDPG1 plays an essential role in early chloroplast biogenesis, and its absence triggers chloroplast-to-nucleus retrograde signalling, which ultimately down-regulates the expression of nuclear genes encoding chloroplast-localized proteins.
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Affiliation(s)
- Dong Liu
- College of Agronomy/Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Weichun Li
- College of Agronomy/Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Jianfeng Cheng
- College of Agronomy/Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045, China
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Wang Y, Wang C, Zheng M, Lyu J, Xu Y, Li X, Niu M, Long W, Wang D, Wang H, Terzaghi W, Wang Y, Wan J. WHITE PANICLE1, a Val-tRNA Synthetase Regulating Chloroplast Ribosome Biogenesis in Rice, Is Essential for Early Chloroplast Development. PLANT PHYSIOLOGY 2016; 170:2110-23. [PMID: 26839129 PMCID: PMC4825129 DOI: 10.1104/pp.15.01949] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 01/31/2016] [Indexed: 05/15/2023]
Abstract
Chloroplasts and mitochondria contain their own genomes and transcriptional and translational systems. Establishing these genetic systems is essential for plant growth and development. Here we characterized a mutant form of a Val-tRNA synthetase (OsValRS2) from Oryza sativa that is targeted to both chloroplasts and mitochondria. A single base change in OsValRS2 caused virescent to albino phenotypes in seedlings and white panicles at heading. We therefore named this mutant white panicle 1 (wp1). Chlorophyll autofluorescence observations and transmission electron microscopy analyses indicated that wp1 mutants are defective in early chloroplast development. RNA-seq analysis revealed that expression of nuclear-encoded photosynthetic genes is significantly repressed, while expression of many chloroplast-encoded genes also changed significantly in wp1 mutants. Western-blot analyses of chloroplast-encoded proteins showed that chloroplast protein levels were reduced in wp1 mutants, although mRNA levels of some genes were higher in wp1 than in wild type. We found that wp1 was impaired in chloroplast ribosome biogenesis. Taken together, our results show that OsValRS2 plays an essential role in chloroplast development and regulating chloroplast ribosome biogenesis.
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Affiliation(s)
- Yunlong Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, PR China;National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; andDepartment of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
| | - Chunming Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, PR China;National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; andDepartment of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
| | - Ming Zheng
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, PR China;National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; andDepartment of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
| | - Jia Lyu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, PR China;National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; andDepartment of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
| | - Yang Xu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, PR China;National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; andDepartment of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
| | - Xiaohui Li
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, PR China;National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; andDepartment of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
| | - Mei Niu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, PR China;National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; andDepartment of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
| | - Wuhua Long
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, PR China;National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; andDepartment of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
| | - Di Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, PR China;National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; andDepartment of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
| | - HaiYang Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, PR China;National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; andDepartment of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
| | - William Terzaghi
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, PR China;National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; andDepartment of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
| | - Yihua Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, PR China;National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; andDepartment of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
| | - Jianmin Wan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, PR China;National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; andDepartment of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
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Yang Z, Shang Z, Wang L, Lu Q, Wen X, Chi W, Zhang L, Lu C. Purine biosynthetic enzyme ATase2 is involved in the regulation of early chloroplast development and chloroplast gene expression in Arabidopsis. PHOTOSYNTHESIS RESEARCH 2015; 126:285-300. [PMID: 25837856 DOI: 10.1007/s11120-015-0131-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 03/24/2015] [Indexed: 05/14/2023]
Abstract
To investigate the molecular mechanism of chloroplast biogenesis and development, we characterized an Arabidopsis mutant (dg169, delayed greening 169) which showed growth retardation and delayed greening phenotype in leaves. Newly emerged chlorotic leaves recovered gradually with leaf development in the mutant, and the mature leaves showed similar phenotype to those of wild-typewild-type plants. Compared with wild-type, the chloroplasts were oval-shaped and smaller and the thylakoid membranes were less abundant in yellow section of young leaves of dg169. In addition, the functions of photosystem II (PSII) and photosystem I (PSI) were also impaired. Furthermore, the amount of core subunits of PSII and PSI, as well as PSII and PSI complexes reduced in yellow section of young leaves of dg169. Map-based positional cloning identified that phenotype of dg169 was attributed to a point mutation of ATase2 which converts the conserved Ile-155 residue to Asn. ATase2 catalyzes the first step of de novo purine biosynthesis. This mutation resulted in impaired purine synthesis and a significant decrease in ATP, ADP, GTP and GDP contents. The analysis of ATase2-GFP protein fusion showed that ATase2 was localized to nucleoid of chloroplasts. Our results further demonstrated that the levels of PEP-dependent transcripts in yellow section of young leaves of dg169 were decreased while NEP-dependent and both PEP- and NEP-dependent transcripts and chloroplast DNA replications were increased. The results in this study suggest that ATase2 plays an essential role in early chloroplast development through maintaining PEP function.
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Affiliation(s)
- Zhipan Yang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
| | - Zengzhen Shang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lei Wang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qingtao Lu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Xiaogang Wen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Wei Chi
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Lixin Zhang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Congming Lu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
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Pfannschmidt T, Blanvillain R, Merendino L, Courtois F, Chevalier F, Liebers M, Grübler B, Hommel E, Lerbs-Mache S. Plastid RNA polymerases: orchestration of enzymes with different evolutionary origins controls chloroplast biogenesis during the plant life cycle. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:6957-73. [PMID: 26355147 DOI: 10.1093/jxb/erv415] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Chloroplasts are the sunlight-collecting organelles of photosynthetic eukaryotes that energetically drive the biosphere of our planet. They are the base for all major food webs by providing essential photosynthates to all heterotrophic organisms including humans. Recent research has focused largely on an understanding of the function of these organelles, but knowledge about the biogenesis of chloroplasts is rather limited. It is known that chloroplasts develop from undifferentiated precursor plastids, the proplastids, in meristematic cells. This review focuses on the activation and action of plastid RNA polymerases, which play a key role in the development of new chloroplasts from proplastids. Evolutionarily, plastids emerged from the endosymbiosis of a cyanobacterium-like ancestor into a heterotrophic eukaryote. As an evolutionary remnant of this process, they possess their own genome, which is expressed by two types of plastid RNA polymerase, phage-type and prokaryotic-type RNA polymerase. The protein subunits of these polymerases are encoded in both the nuclear and plastid genomes. Their activation and action therefore require a highly sophisticated regulation that controls and coordinates the expression of the components encoded in the plastid and nucleus. Stoichiometric expression and correct assembly of RNA polymerase complexes is achieved by a combination of developmental and environmentally induced programmes. This review highlights the current knowledge about the functional coordination between the different types of plastid RNA polymerases and provides working models of their sequential expression and function for future investigations.
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Affiliation(s)
- Thomas Pfannschmidt
- Université Grenoble-Alpes, F-38000 Grenoble, France CNRS, UMR5168, F-38054 Grenoble, France CEA, iRTSV, Laboratoire de Physiologie Cellulaire & Végétale, F-38054 Grenoble, France INRA, USC1359, F-38054 Grenoble, France
| | - Robert Blanvillain
- Université Grenoble-Alpes, F-38000 Grenoble, France CNRS, UMR5168, F-38054 Grenoble, France CEA, iRTSV, Laboratoire de Physiologie Cellulaire & Végétale, F-38054 Grenoble, France INRA, USC1359, F-38054 Grenoble, France
| | - Livia Merendino
- Université Grenoble-Alpes, F-38000 Grenoble, France CNRS, UMR5168, F-38054 Grenoble, France CEA, iRTSV, Laboratoire de Physiologie Cellulaire & Végétale, F-38054 Grenoble, France INRA, USC1359, F-38054 Grenoble, France
| | - Florence Courtois
- Université Grenoble-Alpes, F-38000 Grenoble, France CNRS, UMR5168, F-38054 Grenoble, France CEA, iRTSV, Laboratoire de Physiologie Cellulaire & Végétale, F-38054 Grenoble, France INRA, USC1359, F-38054 Grenoble, France
| | - Fabien Chevalier
- Université Grenoble-Alpes, F-38000 Grenoble, France CNRS, UMR5168, F-38054 Grenoble, France CEA, iRTSV, Laboratoire de Physiologie Cellulaire & Végétale, F-38054 Grenoble, France INRA, USC1359, F-38054 Grenoble, France
| | - Monique Liebers
- Université Grenoble-Alpes, F-38000 Grenoble, France CNRS, UMR5168, F-38054 Grenoble, France CEA, iRTSV, Laboratoire de Physiologie Cellulaire & Végétale, F-38054 Grenoble, France INRA, USC1359, F-38054 Grenoble, France
| | - Björn Grübler
- Université Grenoble-Alpes, F-38000 Grenoble, France CNRS, UMR5168, F-38054 Grenoble, France CEA, iRTSV, Laboratoire de Physiologie Cellulaire & Végétale, F-38054 Grenoble, France INRA, USC1359, F-38054 Grenoble, France
| | - Elisabeth Hommel
- Université Grenoble-Alpes, F-38000 Grenoble, France CNRS, UMR5168, F-38054 Grenoble, France CEA, iRTSV, Laboratoire de Physiologie Cellulaire & Végétale, F-38054 Grenoble, France INRA, USC1359, F-38054 Grenoble, France
| | - Silva Lerbs-Mache
- Université Grenoble-Alpes, F-38000 Grenoble, France CNRS, UMR5168, F-38054 Grenoble, France CEA, iRTSV, Laboratoire de Physiologie Cellulaire & Végétale, F-38054 Grenoble, France INRA, USC1359, F-38054 Grenoble, France
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Huang C, Yu QB, Yuan XB, Li ZR, Wang J, Ye LS, Xu L, Yang ZN. Rubisco accumulation is important for the greening of the fln2-4 mutant in Arabidopsis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2015; 236:185-194. [PMID: 26025532 DOI: 10.1016/j.plantsci.2015.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 03/11/2015] [Accepted: 04/08/2015] [Indexed: 06/04/2023]
Abstract
The fructokinase-like protein2 (FLN2) is a component of the PEP complex. FLN2 knockout mutants displayed a delayed greening phenotype on sucrose-containing medium. Our previous work indicated that partial PEP activity is essential for its greening phenotype. In this study, we further report that sufficient Rubisco accumulation is critical for fln2-4 greening. Sugar serves many important functions, such as an energy source and signaling molecule. Through pharmacological experiments using a sugar analog and sugar signaling inhibitor, we demonstrate that sugar serves as energy to support the fln2-4 greening. Seed-reserve and photosynthetic CO2-fixation are the primary energy sources for early seedling growth. No obvious differences were observed in the seed-reserve of the wild-type and fln2-4 by comparing their seed size and dark-germination, indicating that the defective carbon fixation may account for the energy deficit in fln2-4 during its early seedling growth. The Rubisco content was low in fln2-4, but it rapidly accumulated during the greening of fln2-4. Expression of a nuclear-encoded rbcL gene facilitates Rubisco accumulation and partially complements the mutant defects. These results suggest that the Rubisco accumulation is critical for fln2-4 greening. In summary, the rapid Rubisco accumulation that depends on sufficient PEP activity is important for normal seedling growth.
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Affiliation(s)
- Chao Huang
- Department of Biology, East China Normal University, Shanghai 200241, China.
| | - Qing-Bo Yu
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China.
| | - Xin-Bo Yuan
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China.
| | - Zi-Ran Li
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China.
| | - Jing Wang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China.
| | - Lin-Shan Ye
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China.
| | - Ling Xu
- Department of Biology, East China Normal University, Shanghai 200241, China.
| | - Zhong-Nan Yang
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China.
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