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K. Raval P, MacLeod AI, Gould SB. A molecular atlas of plastid and mitochondrial proteins reveals organellar remodeling during plant evolutionary transitions from algae to angiosperms. PLoS Biol 2024; 22:e3002608. [PMID: 38713727 PMCID: PMC11135702 DOI: 10.1371/journal.pbio.3002608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 05/29/2024] [Accepted: 03/28/2024] [Indexed: 05/09/2024] Open
Abstract
Algae and plants carry 2 organelles of endosymbiotic origin that have been co-evolving in their host cells for more than a billion years. The biology of plastids and mitochondria can differ significantly across major lineages and organelle changes likely accompanied the adaptation to new ecological niches such as the terrestrial habitat. Based on organelle proteome data and the genomes of 168 phototrophic (Archaeplastida) versus a broad range of 518 non-phototrophic eukaryotes, we screened for changes in plastid and mitochondrial biology across 1 billion years of evolution. Taking into account 331,571 protein families (or orthogroups), we identify 31,625 protein families that are unique to primary plastid-bearing eukaryotes. The 1,906 and 825 protein families are predicted to operate in plastids and mitochondria, respectively. Tracing the evolutionary history of these protein families through evolutionary time uncovers the significant remodeling the organelles experienced from algae to land plants. The analyses of gained orthogroups identifies molecular changes of organelle biology that connect to the diversification of major lineages and facilitated major transitions from chlorophytes en route to the global greening and origin of angiosperms.
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Affiliation(s)
- Parth K. Raval
- Institute for Molecular Evolution, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Alexander I. MacLeod
- Institute for Molecular Evolution, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Sven B. Gould
- Institute for Molecular Evolution, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
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Vergara-Cruces Á, Pramanick I, Pearce D, Vogirala VK, Byrne MJ, Low JKK, Webster MW. Structure of the plant plastid-encoded RNA polymerase. Cell 2024; 187:1145-1159.e21. [PMID: 38428394 DOI: 10.1016/j.cell.2024.01.036] [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: 12/18/2023] [Accepted: 01/24/2024] [Indexed: 03/03/2024]
Abstract
Chloroplast genes encoding photosynthesis-associated proteins are predominantly transcribed by the plastid-encoded RNA polymerase (PEP). PEP is a multi-subunit complex composed of plastid-encoded subunits similar to bacterial RNA polymerases (RNAPs) stably bound to a set of nuclear-encoded PEP-associated proteins (PAPs). PAPs are essential to PEP activity and chloroplast biogenesis, but their roles are poorly defined. Here, we present cryoelectron microscopy (cryo-EM) structures of native 21-subunit PEP and a PEP transcription elongation complex from white mustard (Sinapis alba). We identify that PAPs encase the core polymerase, forming extensive interactions that likely promote complex assembly and stability. During elongation, PAPs interact with DNA downstream of the transcription bubble and with the nascent mRNA. The models reveal details of the superoxide dismutase, lysine methyltransferase, thioredoxin, and amino acid ligase enzymes that are subunits of PEP. Collectively, these data provide a foundation for the mechanistic understanding of chloroplast transcription and its role in plant growth and adaptation.
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Affiliation(s)
- Ángel Vergara-Cruces
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Ishika Pramanick
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - David Pearce
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK; School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Vinod K Vogirala
- Electron Bio-Imaging Centre (eBIC), Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Matthew J Byrne
- Electron Bio-Imaging Centre (eBIC), Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Jason K K Low
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2050, Australia
| | - Michael W Webster
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
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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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Seo DH, Jang J, Park D, Yoon Y, Choi YD, Jang G. PEP-ASSOCIATED PROTEIN 3 regulates rice tiller formation and grain yield by controlling chloroplast biogenesis. PLANT PHYSIOLOGY 2024; 194:805-818. [PMID: 37819034 PMCID: PMC10828210 DOI: 10.1093/plphys/kiad536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 08/15/2023] [Accepted: 09/14/2023] [Indexed: 10/13/2023]
Abstract
Plastid-encoded RNA polymerase (PEP) plays a pivotal role in chloroplast development by governing the transcription of chloroplast genes, and PEP-associated proteins (PAPs) modulate PEP transcriptional activity. Therefore, PAPs provide an intriguing target for those efforts to improve yield, by enhancing chloroplast development. In this study, we identified the rice (Oryza sativa) OsPAP3 gene and characterized its function in chloroplast development. OsPAP3 expression was light-dependent and leaf-specific, similar to the PEP-dependent chloroplast gene RUBISCO LARGE SUBUNIT (OsRbcL), and OsPAP3 protein localized to chloroplast nucleoids where PEP functions. Analysis of loss-of-function and gain-of-function mutants showed that the expression of OsPAP3 is tightly linked to chloroplast gene expression and chloroplast biogenesis in rice. Homozygous knockout mutants of OsPAP3 had fewer chloroplasts than wild type, whereas plants overexpressing OsPAP3 had more chloroplasts. Also, OsPAP3 knockout suppressed the PEP-dependent expression of chloroplast genes, but OsPAP3 overexpression increased their expression. These findings indicate that OsPAP3 regulates chloroplast biogenesis in rice by controlling the PEP-dependent expression of chloroplast genes. More importantly, data from 3 seasons of field cultivation revealed that the overexpression of OsPAP3 improves rice grain yield by approximately 25%, largely due to increased tiller formation. Collectively, these observations suggest that OsPAP3 regulates rice growth and productivity by promoting chloroplast development.
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Affiliation(s)
- Deok Hyun Seo
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Jinwoo Jang
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Dongryeol Park
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Youngdae Yoon
- Department of Environmental Health Science, Konkuk University, Seoul 05029, 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
| | - Geupil Jang
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
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Xie W, Xu D, Chen F, Wang Z, Luo J, He Y, Zheng Q, Liu C. Integrated Cytological, Physiological, and Transcriptome Analyses Provide Insight into the Albino Phenotype of Chinese Plum ( Prunus salicina). Int J Mol Sci 2023; 24:14457. [PMID: 37833903 PMCID: PMC10573071 DOI: 10.3390/ijms241914457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/20/2023] [Accepted: 09/20/2023] [Indexed: 10/15/2023] Open
Abstract
Albino seedlings that arise during seed reproduction can have a significant impact on plant growth and breeding. In this research, we present the first report of albino occurrences in the seed reproduction process of Prunus salicina and describe the cytological, physiological, and transcriptomic changes observed in albino seedlings. The albino seedlings which were observed in several plum cultivars exhibited abnormal chloroplast ultrastructure and perturbed stomatal structure. Compared to normal seedlings, the photosynthetic pigment contents in albino seedlings decreased by more than 90%, accompanied by significant reductions in several chlorophyll fluorescence parameters. Furthermore, substantially changed photosynthetic parameters indicated that the photosynthetic capacity and stomatal function were impaired in albino seedlings. Additionally, the activities of the antioxidant enzyme were drastically altered against the background of higher proline and lower ascorbic acid in leaves of albino seedlings. A total of 4048 differentially expressed genes (DEGs) were identified through transcriptomic sequencing, and the downregulated DEGs in albino seedlings were greatly enriched in the pathways for photosynthetic antenna proteins and flavonoid biosynthesis. GLK1 and Ftsz were identified as candidate genes responsible for the impaired chloroplast development and division in albino seedlings. Additionally, the substantial decline in the expression levels of examined photosystem-related chloroplast genes was validated in albino seedlings. Our findings shed light on the intricate physiological and molecular mechanisms driving albino plum seedling manifestation, which will contribute to improving the reproductive and breeding efforts of plums.
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Affiliation(s)
- Weiwei Xie
- Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in South China, Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; (W.X.); (D.X.); (F.C.); (Z.W.); (J.L.); (Y.H.)
- Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China
| | - Dantong Xu
- Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in South China, Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; (W.X.); (D.X.); (F.C.); (Z.W.); (J.L.); (Y.H.)
- Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China
| | - Fangce Chen
- Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in South China, Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; (W.X.); (D.X.); (F.C.); (Z.W.); (J.L.); (Y.H.)
- Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China
| | - Zhengpeng Wang
- Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in South China, Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; (W.X.); (D.X.); (F.C.); (Z.W.); (J.L.); (Y.H.)
- Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China
| | - Jiandong Luo
- Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in South China, Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; (W.X.); (D.X.); (F.C.); (Z.W.); (J.L.); (Y.H.)
- Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China
| | - Yehua He
- Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in South China, Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; (W.X.); (D.X.); (F.C.); (Z.W.); (J.L.); (Y.H.)
- Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China
| | - Qianming Zheng
- Institute of Pomology Science, Guizhou Academy of Agricultural Science, Ministry of Agriculture and Rural Affairs Key Laboratory of Crop Genetic Resources and Germplasm Innovation in Karst Region, Guiyang 550006, China
| | - Chaoyang Liu
- Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in South China, Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; (W.X.); (D.X.); (F.C.); (Z.W.); (J.L.); (Y.H.)
- Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China
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6
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Han H, Zhou Y, Liu H, Chen X, Wang Q, Zhuang H, Sun X, Ling Q, Zhang H, Wang B, Wang J, Tang Y, Wang H, Liu H. Transcriptomics and Metabolomics Analysis Provides Insight into Leaf Color and Photosynthesis Variation of the Yellow-Green Leaf Mutant of Hami Melon ( Cucumis melo L.). PLANTS (BASEL, SWITZERLAND) 2023; 12:1623. [PMID: 37111847 PMCID: PMC10143263 DOI: 10.3390/plants12081623] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 04/03/2023] [Accepted: 04/05/2023] [Indexed: 06/16/2023]
Abstract
Leaf color mutants are ideal materials for studying the regulatory mechanism of chloroplast development and photosynthesis. We isolated a cucumis melo spontaneous mutant (MT), which showed yellow-green leaf phenotype in the whole growing period and could be inherited stably. We compared its leaves with the wild type (WT) in terms of cytology, physiology, transcriptome and metabolism. The results showed that the thylakoid grana lamellae of MT were loosely arranged and fewer in number than WT. Physiological experiments also showed that MT had less chlorophyll content and more accumulation of reactive oxygen species (ROS) than WT. Furthermore, the activity of several key enzymes in C4 photosynthetic carbon assimilation pathway was more enhanced in MT than WT. Transcriptomic and metabolomic analyses showed that differential expression genes and differentially accumulated metabolites in MT were mainly co-enriched in the pathways related to photosystem-antenna proteins, central carbon metabolism, glutathione metabolism, phenylpropanoid biosynthesis and flavonoid metabolism. We also analyzed several key proteins in photosynthesis and chloroplast transport by Western blot. In summary, the results may provide a new insight into the understanding of how plants respond to the impaired photosynthesis by regulating chloroplast development and photosynthetic carbon assimilation pathways.
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Affiliation(s)
- Hongwei Han
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Corps, Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, China; (H.H.)
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Yuan Zhou
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200030, China
| | - Huifang Liu
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Xianjun Chen
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Corps, Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, China; (H.H.)
| | - Qiang Wang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Hongmei Zhuang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Xiaoxia Sun
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Corps, Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, China; (H.H.)
| | - Qihua Ling
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200030, China
| | - Huijun Zhang
- School of Life Science, Huaibei Normal University, Huaibei 235000, China
| | - Baike Wang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Juan Wang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Yaping Tang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Hao Wang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Huiying Liu
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Corps, Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, China; (H.H.)
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Jan M, Liu Z, Rochaix JD, Sun X. Retrograde and anterograde signaling in the crosstalk between chloroplast and nucleus. FRONTIERS IN PLANT SCIENCE 2022; 13:980237. [PMID: 36119624 PMCID: PMC9478734 DOI: 10.3389/fpls.2022.980237] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/18/2022] [Indexed: 06/02/2023]
Abstract
The chloroplast is a complex cellular organelle that not only performs photosynthesis but also synthesizes amino acids, lipids, and phytohormones. Nuclear and chloroplast genetic activity are closely coordinated through signaling chains from the nucleus to chloroplast, referred to as anterograde signaling, and from chloroplast to the nucleus, named retrograde signaling. The chloroplast can act as an environmental sensor and communicates with other cell compartments during its biogenesis and in response to stress, notably with the nucleus through retrograde signaling to regulate nuclear gene expression in response to developmental cues and stresses that affect photosynthesis and growth. Although several components involved in the generation and transmission of plastid-derived retrograde signals and in the regulation of the responsive nuclear genes have been identified, the plastid retrograde signaling network is still poorly understood. Here, we review the current knowledge on multiple plastid retrograde signaling pathways, and on potential plastid signaling molecules. We also discuss the retrograde signaling-dependent regulation of nuclear gene expression within the frame of a multilayered network of transcription factors.
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Affiliation(s)
- Masood Jan
- State Key Laboratory of Cotton Biology and State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Zhixin Liu
- State Key Laboratory of Cotton Biology and State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Jean-David Rochaix
- Department of Molecular Biology and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Xuwu Sun
- State Key Laboratory of Cotton Biology and State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
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Huang X, Abuduwaili N, Wang X, Tao M, Wang X, Huang G. Cotton (Gossypium hirsutum) VIRMA as an N6-Methyladenosine RNA Methylation Regulator Participates in Controlling Chloroplast-Dependent and Independent Leaf Development. Int J Mol Sci 2022; 23:ijms23179887. [PMID: 36077287 PMCID: PMC9456376 DOI: 10.3390/ijms23179887] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/15/2022] [Accepted: 08/16/2022] [Indexed: 11/16/2022] Open
Abstract
N6-methyladenosine (m6A) is one of the most abundant internal modifications of mRNA, which plays important roles in gene expression regulation, and plant growth and development. Vir-like m6A methyltransferase associated (VIRMA) serves as a scaffold for bridging the catalytic core components of the m6A methyltransferase complex. The role of VIRMA in regulating leaf development and its related mechanisms have not been reported. Here, we identified and characterized two upland cotton (Gossypium hirsutum) VIRMA genes, named as GhVIR-A and GhVIR-D, which share 98.5% identity with each other. GhVIR-A and GhVIR-D were ubiquitously expressed in different tissues and relatively higher expressed in leaves and main stem apexes (MSA). Knocking down the expression of GhVIR genes by the virus-induced gene silencing (VIGS) system influences leaf cell size, cell shape, and total cell numbers, thereby determining cotton leaf morphogenesis. The dot-blot assay and colorimetric experiment showed the ratio of m6A to A in mRNA is lower in leaves of GhVIR-VIGS plants compared with control plants. Messenger RNA (mRNA) high-throughput sequencing (RNA-seq) and a qRT-PCR experiment showed that GhVIRs regulate leaf development through influencing expression of some transcription factor genes, tubulin genes, and chloroplast genes including photosystem, carbon fixation, and ribosome assembly. Chloroplast structure, chlorophyll content, and photosynthetic efficiency were changed and unsuitable for leaf growth and development in GhVIR-VIGS plants compared with control plants. Taken together, our results demonstrate GhVIRs function in cotton leaf development by chloroplast dependent and independent pathways.
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Affiliation(s)
- Xiaoyu Huang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Nigara Abuduwaili
- Xinjiang Key Laboratory of Special Species Conservation and Regulatory Biology, College of Life Science, Xinjiang Normal University, Urumuqi 830054, China
| | - Xinting Wang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Miao Tao
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Xiaoqian Wang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Gengqing Huang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
- Xinjiang Key Laboratory of Special Species Conservation and Regulatory Biology, College of Life Science, Xinjiang Normal University, Urumuqi 830054, China
- Correspondence:
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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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Xiong HB, Pan HM, Long QY, Wang ZY, Qu WT, Mei T, Zhang N, Xu XF, Yang ZN, Yu QB. AtNusG, a chloroplast nucleoid protein of bacterial origin linking chloroplast transcriptional and translational machineries, is required for proper chloroplast gene expression in Arabidopsis thaliana. Nucleic Acids Res 2022; 50:6715-6734. [PMID: 35736138 PMCID: PMC9262611 DOI: 10.1093/nar/gkac501] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 05/25/2022] [Accepted: 06/20/2022] [Indexed: 12/24/2022] Open
Abstract
In Escherichia coli, transcription-translation coupling is mediated by NusG. Although chloroplasts are descendants of endosymbiotic prokaryotes, the mechanism underlying this coupling in chloroplasts remains unclear. Here, we report transcription-translation coupling through AtNusG in chloroplasts. AtNusG is localized in chloroplast nucleoids and is closely associated with the chloroplast PEP complex by interacting with its essential component PAP9. It also comigrates with chloroplast ribosomes and interacts with their two components PRPS5 (uS5c) and PRPS10 (uS10c). These data suggest that the transcription and translation machineries are coupled in chloroplasts. In the atnusg mutant, the accumulation of chloroplast-encoded photosynthetic gene transcripts, such as psbA, psbB, psbC and psbD, was not obviously changed, but that of their proteins was clearly decreased. Chloroplast polysomic analysis indicated that the decrease in these proteins was due to the reduced efficiency of their translation in this mutant, leading to reduced photosynthetic efficiency and enhanced sensitivity to cold stress. These data indicate that AtNusG-mediated coupling between transcription and translation in chloroplasts ensures the rapid establishment of photosynthetic capacity for plant growth and the response to environmental changes. Therefore, our study reveals a conserved mechanism of transcription-translation coupling between chloroplasts and E. coli, which perhaps represents a regulatory mechanism of chloroplast gene expression. This study provides insights into the underlying mechanisms of chloroplast gene expression in higher plants.
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Affiliation(s)
| | | | | | - Zi-Yuan Wang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Wan-Tong Qu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Tong Mei
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Nan Zhang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Xiao-Feng Xu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Zhong-Nan Yang
- Correspondence may also be addressed to Zhong-Nan Yang. Tel: +86 21 64324650;
| | - Qing-Bo Yu
- To whom correspondence should be addressed. Tel: +86 21 64324812;
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11
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Wang ZY, Qu WT, Mei T, Zhang N, Yang NY, Xu XF, Xiong HB, Yang ZN, Yu QB. AtRsmD Is Required for Chloroplast Development and Chloroplast Function in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2022; 13:860945. [PMID: 35548310 PMCID: PMC9083416 DOI: 10.3389/fpls.2022.860945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/16/2022] [Indexed: 05/25/2023]
Abstract
AtRsmD was recently demonstrated to be a chloroplast 16S rRNA methyltransferase (MTase) for the m2G915 modification in Arabidopsis. Here, its function of AtRsmD for chloroplast development and photosynthesis was further analyzed. The AtRsmD gene is highly expressed in green photosynthetic tissues. AtRsmD is associated with the thylakoid in chloroplasts. The atrsmd-2 mutant exhibited impaired photosynthetic efficiency in emerging leaves under normal growth conditions. A few thylakoid lamellas could be observed in the chloroplast from the atrsmd-2 mutant, and these thylakoids were loosely organized. Knockout of the AtRsmD gene had minor effects on chloroplast ribosome biogenesis and RNA loading on chloroplast ribosomes, but it reduced the amounts of chloroplast-encoded photosynthesis-related proteins in the emerging leaves, for example, D1, D2, CP43, and CP47, which reduced the accumulation of the photosynthetic complex. Nevertheless, knockout of the AtRsmD gene did not cause a general reduction in chloroplast-encoded proteins in Arabidopsis grown under normal growth conditions. Additionally, the atrsmd-2 mutant exhibited more sensitivity to lincomycin, which specifically inhibits the elongation of nascent polypeptide chains. Cold stress exacerbated the effect on chloroplast ribosome biogenesis in the atrsmd-2 mutant. All these data suggest that the AtRsmD protein plays distinct regulatory roles in chloroplast translation, which is required for chloroplast development and chloroplast function.
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12
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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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13
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Shi C, Shen X, Zhang Z, Zhou Y, Chen R, Luo J, Tang Y, Lu Y, Li F, Ouyang B. Conserved role of Fructokinase-like protein 1 in chloroplast development revealed by a seedling-lethal albino mutant of pepper. HORTICULTURE RESEARCH 2022; 9:uhab084. [PMID: 35048105 PMCID: PMC9016868 DOI: 10.1093/hr/uhab084] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/01/2021] [Accepted: 12/12/2021] [Indexed: 05/24/2023]
Affiliation(s)
- Chunmei Shi
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Xinyan Shen
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Zhiying Zhang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Yuhong Zhou
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Rong Chen
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Jingying Luo
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Yaping Tang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Yongen Lu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Feng Li
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Bo Ouyang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
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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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15
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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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16
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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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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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18
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Characterization and Fine Mapping of a Yellow-Virescent Gene Regulating Chlorophyll Biosynthesis and Early Stage Chloroplast Development in Brassica napus. G3-GENES GENOMES GENETICS 2020; 10:3201-3211. [PMID: 32646913 PMCID: PMC7466985 DOI: 10.1534/g3.120.401460] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Chlorophyll biosynthesis and chloroplast development are crucial to photosynthesis and plant growth, but their regulatory mechanism remains elusive in many crop species. We isolated a Brassica napus yellow-virescent leaf (yvl) mutant, which exhibited yellow-younger-leaf and virescent-older-leaf with decreased chlorophyll accumulation and delayed chloroplast development. We mapped yvl locus to a 70-kb interval between molecular markers yvl-O10 and InDel-O6 on chromosome A03 in BC2F2 population using whole genome re-sequencing and bulked segregant analysis. The mutant had a ‘C’ to ‘T’ substitution in the coding sequence of BnaA03.CHLH, which encodes putative H subunit of Mg-protoporphyrin IX chelatase (CHLH). The mutation resulted in an imperfect protein structure and reduced activity of CHLH. It also hampered the plastid encoded RNA polymerase which transcribes regulatory genes of photosystem II and I. Consequently, the chlorophyll a/b and carotenoid contents were reduced and the chloroplast ultrastructure was degraded in yvl mutant. These results explain that a single nucleotide mutation in BnaA03.CHLH impairs PEP activity to disrupt chloroplast development and chlorophyll biosynthesis in B. napus.
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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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20
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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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21
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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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22
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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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23
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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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24
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He L, Zhang S, Qiu Z, Zhao J, Nie W, Lin H, Zhu Z, Zeng D, Qian Q, Zhu L. FRUCTOKINASE-LIKE PROTEIN 1 interacts with TRXz to regulate chloroplast development in rice. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2018; 60:94-111. [PMID: 29319227 DOI: 10.1111/jipb.12631] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 01/05/2018] [Indexed: 05/18/2023]
Abstract
Chloroplast genes are transcribed by the plastid-encoded RNA polymerase (PEP) or nucleus-encoded RNA polymerase. FRUCTOKINASE-LIKE PROTEINS (FLNs) are phosphofructokinase-B (PfkB)-type carbohydrate kinases that act as part of the PEP complex; however, the molecular mechanisms underlying FLN activity in rice remain elusive. Previously, we identified and characterized a heat-stress sensitive albino (hsa1) mutant in rice. Map-based cloning revealed that HSA1 encodes a putative OsFLN2. Here, we further demonstrated that knockdown or knockout of the OsFLN1, a close homolog of HSA1/OsFLN2, considerably inhibits chloroplast biogenesis and the fln1 knockout mutants, created by clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associate protein 9, exhibit severe albino phenotype and seedling lethality. Moreover, OsFLN1 localizes to the chloroplast. Yeast two-hybrid, pull-down and bimolecular fluorescence complementation experiments revealed that OsFLN1 and HSA1/OsFLN2 interact with THIOREDOXINZ (OsTRXz) to regulate chloroplast development. In agreement with this, knockout of OsTRXz resulted in a similar albino and seedling lethality phenotype to that of the fln1 mutants. Quantitative reverse transcription polymerase chain reaction and immunoblot analysis revealed that the transcription and translation of PEP-dependent genes were strongly inhibited in fln1 and trxz mutants, indicating that loss of OsFLN1, HSA1/OsFLN2, or OsTRXz function perturbs the stability of the transcriptionally active chromosome complex and PEP activity. These results show that OsFLN1 and HSA1/OsFLN2 contribute to chloroplast biogenesis and plant growth.
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Affiliation(s)
- Lei He
- 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
| | - Zhennan Qiu
- 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
| | - Wendan Nie
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Shijiazhuang 050024, China
| | - Haiyan Lin
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Zhengge Zhu
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Shijiazhuang 050024, China
| | - Dali Zeng
- 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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25
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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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26
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Arabidopsis fructokinase-like protein associations are regulated by ATP. Biochem J 2017; 474:1789-1801. [PMID: 28377494 DOI: 10.1042/bcj20161077] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 03/27/2017] [Accepted: 04/03/2017] [Indexed: 02/01/2023]
Abstract
The Arabidopsis thaliana fructokinase-like proteins FLN1 and FLN2 are required for the differentiation of plastids into photosynthetically competent chloroplasts. However, their specific roles are unknown. FLN1 and FLN2 localize in a multisubunit prokaryotic-type polymerase (plastid-encoded RNA polymerase) complex that transcribes genes encoding components of photosynthesis-related assemblies. Despite sequence identity with fructokinases, which are members of the pfkB (phosphofructokinase B) family of enzymes, kinase activity of FLN1 and FLN2 has not been demonstrated. Homology modeling using pfkB X-ray structures, sequence comparisons, and mutational analyses suggests that FLN proteins may bind their substrates differently from other pfkB proteins. We provide evidence that purified recombinant FLN1 undergoes an ATP-mediated change in binding affinity with both itself and recombinant FLN2. The ATP-mediated change in the affinity of FLN1 for FLN2 is not affected by mutations in conserved active-site residues known to affect catalysis in active pfkB enzymes. In contrast, recombinant FLN2 hetero-oligomerizes independently of ATP concentration. At ATP concentrations that promote FLN1 homomeric interactions, the FLN1-FLN2 hetero-oligomer is the dominant form in vitro We further present evidence that FLN1 associates with a large protein complex in chloroplasts independently of ATP. Given that ATP levels fluctuate between light-dark cycles in the 1-5 mM range, we propose that changes in FLN1 and FLN2 interactions are biologically meaningful.
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27
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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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28
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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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29
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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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Kindgren P, Strand Å. Chloroplast transcription, untangling the Gordian Knot. THE NEW PHYTOLOGIST 2015; 206:889-891. [PMID: 25865165 DOI: 10.1111/nph.13388] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Affiliation(s)
- Peter Kindgren
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187, Umeå, Sweden
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, 6009, WA, Australia
| | - Åsa Strand
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187, Umeå, Sweden
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Pfalz J, Holtzegel U, Barkan A, Weisheit W, Mittag M, Pfannschmidt T. ZmpTAC12 binds single-stranded nucleic acids and is essential for accumulation of the plastid-encoded polymerase complex in maize. THE NEW PHYTOLOGIST 2015; 206:1024-1037. [PMID: 25599833 PMCID: PMC6680207 DOI: 10.1111/nph.13248] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 11/19/2014] [Indexed: 05/04/2023]
Abstract
The plastid-encoded plastid RNA polymerase (PEP) represents the major transcription machinery in mature chloroplasts. Proteomic studies identified four plastome- and at least ten nuclear-encoded proteins making up this multimeric enzyme. Depletion of single subunits is known to result in strongly diminished PEP activity causing severe defects in chloroplast biogenesis. Here, we characterized one PEP subunit in maize, ZmpTAC12, and investigated the molecular basis underlying PEP-deficiency in Zmptac12 mutants. We show that the ZmpTAC12 gene encodes two different protein isoforms, both of which localize dually in chloroplasts and nuclei. Moreover, both variants assemble into the PEP-complex. Analysis of PEP-complex assembly in various maize mutants lacking different PEP-complex components demonstrates that ZmpTAC12, ZmpTAC2, ZmpTAC10 and ZmMurE are each required to accumulate a fully assembled PEP-complex. Antibodies to ZmpTAC12 coimmunoprecipitate a subset of plastid RNAs that are synthesized by PEP-dependent transcription. Gel mobility shift analyses with recombinant ZmpTAC12 revealed binding capabilities with ssRNA and ssDNA, but not dsDNA. Collectively these data demonstrate that ZmpTAC12 is required for the proper build-up of the PEP-complex and that it interacts with single-stranded nucleic acids.
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Affiliation(s)
- Jeannette Pfalz
- Department of Plant PhysiologyInstitute of General Botany and Plant PhysiologyFriedrich‐Schiller‐University JenaD‐07743JenaGermany
| | - Ute Holtzegel
- Department of Plant PhysiologyInstitute of General Botany and Plant PhysiologyFriedrich‐Schiller‐University JenaD‐07743JenaGermany
| | - Alice Barkan
- Institute of Molecular BiologyUniversity of OregonEugeneOR97403USA
| | - Wolfram Weisheit
- Department of General BotanyInstitute of General Botany and Plant PhysiologyFriedrich‐Schiller‐University JenaD‐07743JenaGermany
| | - Maria Mittag
- Department of General BotanyInstitute of General Botany and Plant PhysiologyFriedrich‐Schiller‐University JenaD‐07743JenaGermany
| | - Thomas Pfannschmidt
- Department of Plant PhysiologyInstitute of General Botany and Plant PhysiologyFriedrich‐Schiller‐University JenaD‐07743JenaGermany
- University Grenoble‐AlpesF‐38000GrenobleFrance
- CNRSUMR5168F‐38054GrenobleFrance
- CEAiRTSVLaboratoire de Physiologie Cellulaire & VégétaleF‐38054GrenobleFrance
- INRAUSC1359F‐38054GrenobleFrance
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Involvement of thiol-based mechanisms in plant development. Biochim Biophys Acta Gen Subj 2015; 1850:1479-96. [PMID: 25676896 DOI: 10.1016/j.bbagen.2015.01.023] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 01/08/2015] [Accepted: 01/10/2015] [Indexed: 12/21/2022]
Abstract
BACKGROUND Increasing knowledge has been recently gained regarding the redox regulation of plant developmental stages. SCOPE OF VIEW The current state of knowledge concerning the involvement of glutathione, glutaredoxins and thioredoxins in plant development is reviewed. MAJOR CONCLUSIONS The control of the thiol redox status is mainly ensured by glutathione (GSH), a cysteine-containing tripeptide and by reductases sharing redox-active cysteines, glutaredoxins (GRXs) and thioredoxins (TRXs). Indeed, thiol groups present in many regulatory proteins and metabolic enzymes are prone to oxidation, ultimately leading to post-translational modifications such as disulfide bond formation or glutathionylation. This review focuses on the involvement of GSH, GRXs and TRXs in plant development. Recent studies showed that the proper functioning of root and shoot apical meristems depends on glutathione content and redox status, which regulate, among others, cell cycle and hormone-related processes. A critical role of GRXs in the formation of floral organs has been uncovered, likely through the redox regulation of TGA transcription factor activity. TRXs fulfill many functions in plant development via the regulation of embryo formation, the control of cell-to-cell communication, the mobilization of seed reserves, the biogenesis of chloroplastic structures, the metabolism of carbon and the maintenance of cell redox homeostasis. This review also highlights the tight relationships between thiols, hormones and carbon metabolism, allowing a proper development of plants in relation with the varying environment and the energy availability. GENERAL SIGNIFICANCE GSH, GRXs and TRXs play key roles during the whole plant developmental cycle via their antioxidant functions and the redox-regulation of signaling pathways. This article is part of a Special Issue entitled Redox regulation of differentiation and de-differentiation.
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Wimmelbacher M, Börnke F. Redox activity of thioredoxin z and fructokinase-like protein 1 is dispensable for autotrophic growth of Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:2405-13. [PMID: 24659486 PMCID: PMC4036507 DOI: 10.1093/jxb/eru122] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Redox modulation of protein activity by thioredoxins (TRXs) plays a key role in cellular regulation. Thioredoxin z (TRX z) and its interaction partner fructokinase-like protein 1 (FLN1) represent subunits of the plastid-encoded RNA polymerase (PEP), suggesting a role of both proteins in redox regulation of chloroplast gene expression. Loss of TRX z or FLN1 expression generates a PEP-deficient phenotype and renders the plants incapable to grow autotrophically. This study shows that PEP function in trx z and fln1 plants can be restored by complementation with redox-inactive TRX z C106S and FLN1 C105/106A protein variants, respectively. The complemented plants showed wild-type levels of chloroplast gene expression and were restored in photosynthetic capacity, indicating that redox regulation of PEP through TRX z/FLN1 per se is not essential for autotrophic growth. Promoter-reporter gene studies indicate that TRX z and FLN1 are expressed during early phases of leaf development while expression ceases at maturation. Taken together, our data support a model in which TRX z and FLN1 are essential structural components of the PEP complex and their redox activity might only play a role in the fine tuning of PEP function.
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Affiliation(s)
- Matthias Wimmelbacher
- Friedrich-Alexander-Universität, Department of Biology, Division of Biochemistry, Staudtstr. 5, 91058 Erlangen, Germany
| | - Frederik Börnke
- Leibniz-Institute of Vegetable and Ornamental Crops (IGZ), Theodor-Echtermeyer-Weg 1, 14979 Großbeeren, Germany Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany
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Yua QB, Ma Q, Kong MM, Zhao TT, Zhang XL, Zhou Q, Huang C, Chong K, Yang ZN. AtECB1/MRL7, a thioredoxin-like fold protein with disulfide reductase activity, regulates chloroplast gene expression and chloroplast biogenesis in Arabidopsis thaliana. MOLECULAR PLANT 2014; 7:206-17. [PMID: 23956074 DOI: 10.1093/mp/sst092] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Plastid-encoded RNA polymerase (PEP) is closely associated with numerous factors to form PEP complex for plastid gene expression and chloroplast development. However, it is not clear how PEP complex are regulated in chloroplast. Here, one thioredoxin-like fold protein, Arabidopsis early chloroplast biogenesis 1 (AtECB1), an allele of MRL7, was identified to regulate PEP function and chloroplast biogenesis. The knockout lines for AtECB1 displayed albino phenotype and impaired chloroplast development. The transcripts of PEP-dependent plastid genes were barely detected, suggesting that the PEP activity is almost lost in atecb1-1. Although AtECB1 was not identified in PEP complex, a yeast two-hybrid assay and pull-down experiments demonstrated that it can interact with Trx Z and FSD3, two intrinsic subunits of PEP complex, respectively. This indicates that AtECB1 may play a regulatory role for PEP-dependent plastid gene expression through these two subunits. AtECB1 contains a βαβαββα structure in the thioredoxin-like fold domain and lacks the typical C-X-X-C active site motif. Insulin assay demonstrated that AtECB1 harbors disulfide reductase activity in vitro using the purified recombinant AtECB1 protein. This showed that this thioredoxin-like fold protein, AtECB1 also has the thioredoxin activity. AtECB1 may play a role in thioredoxin signaling to regulate plastid gene expression and chloroplast development.
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Affiliation(s)
- Qing-Bo Yua
- Biology Department, Life and Environmental College, Shanghai Normal University, Shanghai 200234, China
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Yu QB, Huang C, Yang ZN. Nuclear-encoded factors associated with the chloroplast transcription machinery of higher plants. FRONTIERS IN PLANT SCIENCE 2014; 5:316. [PMID: 25071799 PMCID: PMC4080259 DOI: 10.3389/fpls.2014.00316] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 06/14/2014] [Indexed: 05/02/2023]
Abstract
Plastid transcription is crucial for plant growth and development. There exist two types of RNA polymerases in plastids: a nuclear-encoded RNA polymerase (NEP) and plastid-encoded RNA polymerase (PEP). PEP is the major RNA polymerase activity in chloroplast. Its core subunits are encoded by the plastid genome, and these are embedded into a larger complex of nuclear-encoded subunits. Biochemical and genetics analysis identified at least 12 proteins are tightly associated with the core subunit, while about 34 further proteins are associated more loosely generating larger complexes such as the transcriptionally active chromosome (TAC) or a part of the nucleoid. Domain analyses and functional investigations suggested that these nuclear-encoded factors may form several functional modules that mediate regulation of plastid gene expression by light, redox, phosphorylation, and heat stress. Genetic analyses also identified that some nuclear-encoded proteins in the chloroplast that are important for plastid gene expression, although a physical association with the transcriptional machinery is not observed. This covers several PPR proteins including CLB19, PDM1/SEL1, OTP70, and YS1 which are involved in the processing of transcripts for PEP core subunit as well as AtECB2, Prin2, SVR4-Like, and NARA5 that are also important for plastid gene expression, although their functions are unclear.
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Affiliation(s)
- Qing-Bo Yu
- Department of Biology, College of Life and Environmental Sciences, Shanghai Normal UniversityShanghai, China
- Institute for Plant Gene Function, Department of Biology, Shanghai Normal UniversityShanghai, China
| | - Chao Huang
- Department of Biology, College of Life and Environmental Sciences, Shanghai Normal UniversityShanghai, China
- Institute for Plant Gene Function, Department of Biology, Shanghai Normal UniversityShanghai, China
| | - Zhong-Nan Yang
- Department of Biology, College of Life and Environmental Sciences, Shanghai Normal UniversityShanghai, China
- Institute for Plant Gene Function, Department of Biology, Shanghai Normal UniversityShanghai, China
- *Correspondence: Zhong-Nan Yang, Department of Biology, College of Life and Environmental Sciences, Shanghai Normal University, No.100, Rd. GuiLin, Shanghai 200234, China e-mail:
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Qiao J, Li J, Chu W, Luo M. PRDA1, a novel chloroplast nucleoid protein, is required for early chloroplast development and is involved in the regulation of plastid gene expression in Arabidopsis. PLANT & CELL PHYSIOLOGY 2013; 54:2071-84. [PMID: 24132784 DOI: 10.1093/pcp/pct148] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Chloroplast development requires accurate spatio-temporal expression of plastid genes. The regulation of plastid genes mediated by plastid-encoded RNA polymerase (PEP) is rather complex, and its related mechanism remains largely unclear. Here, we report the identification of a novel protein that is essential for plant development, PEP-Related Development Arrested 1 (PRDA1). Knock-out of PRDA1 in Arabidopsis (prda1 mutant) caused a seedling-lethal, albino phenotype and arrested the development of leaf chloroplasts. Localization analysis showed that PRDA1 was specifically targeted to chloroplasts and co-localized with chloroplast nucleoids, revealing that PRDA1 is a chloroplast nucleoid-associated protein. Gene expression analyses revealed that the PEP-dependent plastid transcript levels were greatly reduced in prda1. PRDA1 was co-expressed with most of the PEP-associated proteins. Protein interaction assays showed that PRDA1 clearly interacts with MRL7 and FSD2, both of which have been verified as essential for PEP-related chloroplast development. Reactive oxygen species scavenging through dimethylthiourea markedly alleviated the cotyledon-albino phenotypes of PRDA1 and MRL7 RNA interference seedlings. These results demonstrate that PRDA1 is required for early chloroplast development and involved in the regulation of plastid gene expression.
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Affiliation(s)
- Jiangwei Qiao
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China
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Huang C, Yu QB, Lv RH, Yin QQ, Chen GY, Xu L, Yang ZN. The reduced plastid-encoded polymerase-dependent plastid gene expression leads to the delayed greening of the Arabidopsis fln2 mutant. PLoS One 2013; 8:e73092. [PMID: 24019900 PMCID: PMC3760890 DOI: 10.1371/journal.pone.0073092] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 07/19/2013] [Indexed: 12/21/2022] Open
Abstract
In Arabidopsis leaf coloration mutants, the delayed greening phenomenon is common. Nonetheless, the mechanism remains largely elusive. Here, a delayed greening mutant fln2–4 of FLN2 (Fructokinase-Like Protein2) was studied. FLN2 is one component of Transcriptionally Active Chromosome (TAC) complex which is thought to contain the complete plastid-encoded polymerase (PEP). fln2–4 displayed albino phenotype on medium without sucrose. The PEP-dependent plastid gene expression and chloroplast development were inhibited in fln2–4. Besides interacting with thioredoxin z (TRX z), we identified that FLN2 interacted with another two members of TAC complex in yeast including its homologous protein FLN1 (Fructokinase-Like Protein1) and pTAC5. This indicates that FLN2 functions in regulation of PEP activity associated with these TAC components. fln2–4 exhibited delayed greening on sucrose-containing medium. Comparison of the PEP-dependent gene expression among two complete albino mutants (trx z and ptac14), two yellow mutants (ecb2–2 and ys1) and the fln2–4 showed that fln2–4 remains partial PEP activity. FLN2 and FLN1 are the target proteins of TRX z involved in affecting the PEP activity. Together with the data that FLN1 could interact with itself in yeast, FLN1 may form a homodimer to replace FLN1–FLN2 as the TRX z target in redox pathway for maintaining partial PEP activity in fln2–4. We proposed the partial PEP activity in the fln2 mutant allowed plastids to develop into fully functional chloroplasts when exogenous sucrose was supplied, and finally the mutants exhibited green phenotype.
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Affiliation(s)
- Chao Huang
- Department of Biology, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, P.R. China
- Department of Biology, School of Life Sciences, East China Normal University, Shanghai, P.R. China
| | - Qing-Bo Yu
- Department of Biology, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, P.R. China
| | - Ruo-Hong Lv
- Department of Biology, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, P.R. China
| | - Qian-Qian Yin
- Department of Biology, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, P.R. China
| | - Gen-Yun Chen
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Science, Chinese Academy of Sciences, Shanghai, P.R. China
| | - Ling Xu
- Department of Biology, School of Life Sciences, East China Normal University, Shanghai, P.R. China
| | - Zhong-Nan Yang
- Department of Biology, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, P.R. China
- * E-mail:
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