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Liu Y, Zhan J, Li J, Lian M, Li J, Xia C, Zhou F, Xie W. Characterization of the DNA accessibility of chloroplast genomes in grasses. Commun Biol 2024; 7:760. [PMID: 38909165 PMCID: PMC11193712 DOI: 10.1038/s42003-024-06374-4] [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: 10/06/2022] [Accepted: 05/23/2024] [Indexed: 06/24/2024] Open
Abstract
Although the chloroplast genome (cpDNA) of higher plants is known to exist as a large protein-DNA complex called 'plastid nucleoid', researches on its DNA state and regulatory elements are limited. In this study, we performed the assay for transposase-accessible chromatin sequencing (ATAC-seq) on five common tissues across five grasses, and found that the accessibility of different regions in cpDNA varied widely, with the transcribed regions being highly accessible and accessibility patterns around gene start and end sites varying depending on the level of gene expression. Further analysis identified a total of 3970 putative protein binding footprints on cpDNAs of five grasses. These footprints were enriched in intergenic regions and co-localized with known functional elements. Footprints and their flanking accessibility varied dynamically among tissues. Cross-species analysis showed that footprints in coding regions tended to overlap non-degenerate sites and contain a high proportion of highly conserved sites, indicating that they are subject to evolutionary constraints. Taken together, our results suggest that the accessibility of cpDNA has biological implications and provide new insights into the transcriptional regulation of chloroplasts.
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Affiliation(s)
- Yinmeng Liu
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430000, China
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430000, China
| | - Jinling Zhan
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430000, China
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430000, China
| | - Junjie Li
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430000, China
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430000, China
| | - Mengjie Lian
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430000, China
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430000, China
| | - Jiacheng Li
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430000, China
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430000, China
| | - Chunjiao Xia
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430000, China
| | - Fei Zhou
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430000, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430000, China
| | - Weibo Xie
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430000, China.
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430000, China.
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Cai Z, Wang X, Xie Z, Wen Z, Yu X, Xu S, Su X, Luo J. Light response of gametophyte in Adiantum flabellulatum: transcriptome analysis and identification of key genes and pathways. FRONTIERS IN PLANT SCIENCE 2023; 14:1222414. [PMID: 37746005 PMCID: PMC10513451 DOI: 10.3389/fpls.2023.1222414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Accepted: 08/22/2023] [Indexed: 09/26/2023]
Abstract
Light serves not only as a signaling cue perceived by plant photoreceptors but also as an essential energy source captured by chloroplasts. However, excessive light can impose stress on plants. Fern gametophytes possess the unique ability to survive independently and play a critical role in the alternation of generations. Due to their predominantly shaded distribution under canopies, light availability becomes a limiting factor for gametophyte survival, making it imperative to investigate their response to light. Previous research on fern gametophytes' light response has been limited to the physiological level. In this study, we examined the light response of Adiantum flabellulatum gametophytes under different photosynthetic photon flux density (PPFD) levels and identified their high sensitivity to low light. We thereby determined optimal and stress-inducing light conditions. By employing transcriptome sequencing, weighted gene co-expression network analysis, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, we identified 10,995 differentially expressed genes (DEGs). Notably, 3 PHYBs and 5 Type 1 CRYs (CRY1s) were significantly down-regulated at low PPFD (0.1 μmol m-2 s-1). Furthermore, we annotated 927 DEGs to pathways related to photosynthesis and 210 to the flavonoid biosynthesis pathway involved in photoprotection. Additionally, we predicted 34 transcription factor families and identified a close correlation between mTERFs and photosynthesis, as well as a strong co-expression relationship between MYBs and bHLHs and genes encoding flavonoid synthesis enzymes. This comprehensive analysis enhances our understanding of the light response of fern gametophytes and provides novel insights into the mechanisms governing their responses to light.
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Affiliation(s)
- Zeping Cai
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, Hainan, China
| | - Xiaochen Wang
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, Hainan, China
| | - Zhenyu Xie
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, Hainan, China
| | - Zhenyi Wen
- College of Ecology and Environment, Hainan University, Haikou, Hainan, China
| | - Xudong Yu
- Key Laboratory of Germplasm Resources Biology of Tropical Special Ornamental Plants of Hainan Province, College of Forestry, Hainan University, Haikou, China
| | - Shitao Xu
- Key Laboratory of Germplasm Resources Biology of Tropical Special Ornamental Plants of Hainan Province, College of Forestry, Hainan University, Haikou, China
| | - Xinyu Su
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, Hainan, China
| | - Jiajia Luo
- Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan, 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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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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Kim M, Schulz V, Brings L, Schoeller T, Kühn K, Vierling E. mTERF18 and ATAD3 are required for mitochondrial nucleoid structure and their disruption confers heat tolerance in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2021; 232:2026-2042. [PMID: 34482561 DOI: 10.1111/nph.17717] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/23/2021] [Indexed: 05/27/2023]
Abstract
Mitochondria play critical roles in generating ATP through oxidative phosphorylation (OXPHOS) and produce both damaging and signaling reactive oxygen species (ROS). They have reduced genomes that encode essential subunits of the OXPHOS machinery. Mitochondrial Transcription tERmination Factor-related (mTERF) proteins are involved in organelle gene expression, interacting with organellar DNA or RNA. We previously found that mutations in Arabidopsis thaliana mTERF18/SHOT1 enable plants to better tolerate heat and oxidative stresses, presumably due to low ROS production and reduced oxidative damage. Here we discover that shot1 mutants have greatly reduced OXPHOS complexes I and IV and reveal that suppressor of hot1-4 1 (SHOT1) binds DNA and localizes to mitochondrial nucleoids, which are disrupted in shot1. Furthermore, three homologues of animal ATPase family AAA domain-containing protein 3 (ATAD3), which is involved in mitochondrial nucleoid organization, were identified as SHOT1-interacting proteins. Importantly, disrupting ATAD3 function disrupts nucleoids, reduces accumulation of complex I, and enhances heat tolerance, as is seen in shot1 mutants. Our data link nucleoid organization to OXPHOS biogenesis and suggest that the common defects in shot1 mutants and ATAD3-disrupted plants lead to critical changes in mitochondrial metabolism and signaling that result in plant heat tolerance.
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Affiliation(s)
- Minsoo Kim
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Vincent Schulz
- Department of Life Sciences, Institute of Biology, Humboldt-Universität zu Berlin, 10099, Berlin, Germany
| | - Lea Brings
- Department of Life Sciences, Institute of Biology, Humboldt-Universität zu Berlin, 10099, Berlin, Germany
| | - Theresa Schoeller
- Department of Plant Physiology, Institute of Biology, Martin-Luther-Universität Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Kristina Kühn
- Department of Life Sciences, Institute of Biology, Humboldt-Universität zu Berlin, 10099, Berlin, Germany
- Department of Plant Physiology, Institute of Biology, Martin-Luther-Universität Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Elizabeth Vierling
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA, 01003, USA
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Wang M, Zhou F, Wang HM, Xue DX, Liu YG, Zhang QY. A rice mTERF protein V14 sustains photosynthesis establishment and temperature acclimation in early seedling leaves. BMC PLANT BIOLOGY 2021; 21:406. [PMID: 34488627 PMCID: PMC8420055 DOI: 10.1186/s12870-021-03192-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 08/28/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Plant mitochondrial transcription termination factor (mTERF) family members play important roles in development and stress tolerance through regulation of organellar gene expression. However, their molecular functions have yet to be clearly defined. RESULTS Here an mTERF gene V14 was identified by fine mapping using a conditional albino mutant v14 that displayed albinism only in the first two true leaves, which was confirmed by transgenic complementation tests. Subcellular localization and real-time PCR analyses indicated that V14 encodes a chloroplastic protein ubiquitously expressed in leaves while spiking in the second true leaf. Chloroplastic gene expression profiling in the pale leaves of v14 through real-time PCR and Northern blotting analyses showed abnormal accumulation of the unprocessed transcripts covering the rpoB-rpoC1 and/or rpoC1-rpoC2 intercistronic regions accompanied by reduced abundance of the mature rpoC1 and rpoC2 transcripts, which encode two core subunits of the plastid-encoded plastid RNA polymerase (PEP). Subsequent immunoblotting analyses confirmed the reduced accumulation of RpoC1 and RpoC2. A light-inducible photosynthetic gene psbD was also found down-regulated at both the mRNA and protein levels. Interestingly, such stage-specific aberrant posttranscriptional regulation and psbD expression can be reversed by high temperatures (30 ~ 35 °C), although V14 expression lacks thermo-sensitivity. Meanwhile, three V14 homologous genes were found heat-inducible with similar temporal expression patterns, implicating their possible functional redundancy to V14. CONCLUSIONS These data revealed a critical role of V14 in chloroplast development, which impacts, in a stage-specific and thermo-sensitive way, the appropriate processing of rpoB-rpoC1-rpoC2 precursors and the expression of certain photosynthetic proteins. Our findings thus expand the knowledge of the molecular functions of rice mTERFs and suggest the contributions of plant mTERFs to photosynthesis establishment and temperature acclimation.
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Affiliation(s)
- Man Wang
- Present Address: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou, 510642 China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642 China
| | - Feng Zhou
- Present Address: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou, 510642 China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642 China
| | - Hong Mei Wang
- Present Address: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou, 510642 China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642 China
| | - De Xing Xue
- Present Address: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou, 510642 China
| | - Yao-Guang Liu
- Present Address: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou, 510642 China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642 China
- SCAU Main Campus Teaching & Research Base, Guangzhou, China
| | - Qun Yu Zhang
- Present Address: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Sciences, South China Agricultural University, Guangzhou, 510642 China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642 China
- SCAU Main Campus Teaching & Research Base, Guangzhou, China
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Tang Y, Zhao Y, Li C, Yang G, Peng J, Xu Z. New insights into the evolutionary characteristic between the New World and Old World Lupinus species using complete chloroplast genomes. ALL LIFE 2021. [DOI: 10.1080/26895293.2021.1926341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Affiliation(s)
- Yiwang Tang
- Hunan Research Center of Engineering Technology for Utilization of Environmental and Resources Plant, Central South University of Forestry and Technology, Changsha, People’s Republic of China
| | - Yunlin Zhao
- Hunan Research Center of Engineering Technology for Utilization of Environmental and Resources Plant, Central South University of Forestry and Technology, Changsha, People’s Republic of China
| | - Chaoyang Li
- Hunan Research Center of Engineering Technology for Utilization of Environmental and Resources Plant, Central South University of Forestry and Technology, Changsha, People’s Republic of China
| | - Guiyan Yang
- Hunan Research Center of Engineering Technology for Utilization of Environmental and Resources Plant, Central South University of Forestry and Technology, Changsha, People’s Republic of China
- College of Forestry, Northwest A & F University, Yangling, People’s Republic of China
| | - Jiao Peng
- Hunan Research Center of Engineering Technology for Utilization of Environmental and Resources Plant, Central South University of Forestry and Technology, Changsha, People’s Republic of China
| | - Zhenggang Xu
- Hunan Research Center of Engineering Technology for Utilization of Environmental and Resources Plant, Central South University of Forestry and Technology, Changsha, People’s Republic of China
- College of Forestry, Northwest A & F University, Yangling, People’s Republic of China
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Wobbe L. The Molecular Function of Plant mTERFs as Key Regulators of Organellar Gene Expression. PLANT & CELL PHYSIOLOGY 2021; 61:2004-2017. [PMID: 33067620 DOI: 10.1093/pcp/pcaa132] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 09/25/2020] [Indexed: 05/27/2023]
Abstract
The protein family of mTERFs (mitochondrial transcription termination factors) was initially studied in mammalian and insect mitochondria before the first Arabidopsis mTERF mutant was characterized. More than 10 years of research on the function of plant mTERFs in the flowering plants Arabidopsis thaliana, Zea mays and the green microalga Chlamydomonas reinhardtii has since highlighted that mTERFs are key regulators of organellar gene expression (OGE) in mitochondria and in chloroplasts. Additional functions to be fulfilled by plant mTERFs (e.g. splicing) and the fact that the expression of two organellar genomes had to be facilitated have led to a massive expansion of the plant mTERF portfolio compared to that found in mammals. Plant mTERFs are implicated in all steps of OGE ranging from the modulation of transcription to the maturation of tRNAs and hence translation. Furthermore, being regulators of OGE, mTERFs are required for a successful long-term acclimation to abiotic stress, retrograde signaling and interorganellar communication. Here, I review the recent progress in the elucidation of molecular mTERF functions.
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Affiliation(s)
- Lutz Wobbe
- Algae Biotechnology & Bioenergy Group, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, Universit�tsstrasse 27, Bielefeld 33615, Germany
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Méteignier LV, Ghandour R, Zimmerman A, Kuhn L, Meurer J, Zoschke R, Hammani K. Arabidopsis mTERF9 protein promotes chloroplast ribosomal assembly and translation by establishing ribonucleoprotein interactions in vivo. Nucleic Acids Res 2021; 49:1114-1132. [PMID: 33398331 PMCID: PMC7826268 DOI: 10.1093/nar/gkaa1244] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 12/07/2020] [Accepted: 12/13/2020] [Indexed: 12/13/2022] Open
Abstract
The mitochondrial transcription termination factor proteins are nuclear-encoded nucleic acid binders defined by degenerate tandem helical-repeats of ∼30 amino acids. They are found in metazoans and plants where they localize in organelles. In higher plants, the mTERF family comprises ∼30 members and several of these have been linked to plant development and response to abiotic stress. However, knowledge of the molecular basis underlying these physiological effects is scarce. We show that the Arabidopsis mTERF9 protein promotes the accumulation of the 16S and 23S rRNAs in chloroplasts, and interacts predominantly with the 16S rRNA in vivo and in vitro. Furthermore, mTERF9 is found in large complexes containing ribosomes and polysomes in chloroplasts. The comprehensive analysis of mTERF9 in vivo protein interactome identified many subunits of the 70S ribosome whose assembly is compromised in the null mterf9 mutant, putative ribosome biogenesis factors and CPN60 chaperonins. Protein interaction assays in yeast revealed that mTERF9 directly interact with these proteins. Our data demonstrate that mTERF9 integrates protein-protein and protein-RNA interactions to promote chloroplast ribosomal assembly and translation. Besides extending our knowledge of mTERF functional repertoire in plants, these findings provide an important insight into the chloroplast ribosome biogenesis.
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Affiliation(s)
- Louis-Valentin Méteignier
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - Rabea Ghandour
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Aude Zimmerman
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - Lauriane Kuhn
- Plateforme protéomique Strasbourg Esplanade FRC1589 du CNRS, Université de Strasbourg, 15 rue René Descartes, 67084 Strasbourg, France
| | - Jörg Meurer
- Plant Sciences, Faculty of Biology, Ludwig-Maximilians-University Munich, Großhaderner Street 2-4, 82152 Planegg-Martinsried, Germany
| | - Reimo Zoschke
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Kamel Hammani
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
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Arabidopsis Mitochondrial Transcription Termination Factor mTERF2 Promotes Splicing of Group IIB Introns. Cells 2021; 10:cells10020315. [PMID: 33546419 PMCID: PMC7913559 DOI: 10.3390/cells10020315] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 12/21/2022] Open
Abstract
Plastid gene expression (PGE) is essential for chloroplast biogenesis and function and, hence, for plant development. However, many aspects of PGE remain obscure due to the complexity of the process. A hallmark of nuclear-organellar coordination of gene expression is the emergence of nucleus-encoded protein families, including nucleic-acid binding proteins, during the evolution of the green plant lineage. One of these is the mitochondrial transcription termination factor (mTERF) family, the members of which regulate various steps in gene expression in chloroplasts and/or mitochondria. Here, we describe the molecular function of the chloroplast-localized mTERF2 in Arabidopsis thaliana. The complete loss of mTERF2 function results in embryo lethality, whereas directed, microRNA (amiR)-mediated knockdown of MTERF2 is associated with perturbed plant development and reduced chlorophyll content. Moreover, photosynthesis is impaired in amiR-mterf2 plants, as indicated by reduced levels of photosystem subunits, although the levels of the corresponding messenger RNAs are not affected. RNA immunoprecipitation followed by RNA sequencing (RIP-Seq) experiments, combined with whole-genome RNA-Seq, RNA gel-blot, and quantitative RT-PCR analyses, revealed that mTERF2 is required for the splicing of the group IIB introns of ycf3 (intron 1) and rps12.
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Jiang D, Chen J, Zhang Z, Hou X. Mitochondrial Transcription Termination Factor 27 Is Required for Salt Tolerance in Arabidopsis thaliana. Int J Mol Sci 2021; 22:ijms22031466. [PMID: 33540552 PMCID: PMC7867191 DOI: 10.3390/ijms22031466] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/22/2021] [Accepted: 01/26/2021] [Indexed: 01/15/2023] Open
Abstract
In plants, mTERF proteins are primarily found in mitochondria and chloroplasts. Studies have identified several mTERF proteins that affect plant development, respond to abiotic stresses, and regulate organellar gene expression, but the functions and underlying mechanisms of plant mTERF proteins remain largely unknown. Here, we investigated the function of Arabidopsis mTERF27 using molecular genetic, cytological, and biochemical approaches. Arabidopsis mTERF27 had four mTERF motifs and was evolutionarily conserved from moss to higher plants. The phenotype of the mTERF27-knockout mutant mterf27 did not differ obviously from that of the wild-type under normal growth conditions but was hypersensitive to salt stress. mTERF27 was localized to the mitochondria, and the transcript levels of some mitochondrion-encoded genes were reduced in the mterf27 mutant. Importantly, loss of mTERF27 function led to developmental defects in the mitochondria under salt stress. Furthermore, mTERF27 formed homomers and directly interacted with multiple organellar RNA editing factor 8 (MORF8). Thus, our results indicated that mTERF27 is likely crucial for mitochondrial development under salt stress, and that this protein may be a member of the protein interaction network regulating mitochondrial gene expression.
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Research Progress in the Molecular Functions of Plant mTERF Proteins. Cells 2021; 10:cells10020205. [PMID: 33494215 PMCID: PMC7909791 DOI: 10.3390/cells10020205] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 01/16/2021] [Accepted: 01/18/2021] [Indexed: 12/16/2022] Open
Abstract
Present-day chloroplast and mitochondrial genomes contain only a few dozen genes involved in ATP synthesis, photosynthesis, and gene expression. The proteins encoded by these genes are only a small fraction of the many hundreds of proteins that act in chloroplasts and mitochondria. Hence, the vast majority, including components of organellar gene expression (OGE) machineries, are encoded by nuclear genes, translated into the cytosol and imported to these organelles. Consequently, the expression of nuclear and organellar genomes has to be very precisely coordinated. Furthermore, OGE regulation is crucial to chloroplast and mitochondria biogenesis, and hence, to plant growth and development. Notwithstanding, the molecular mechanisms governing OGE are still poorly understood. Recent results have revealed the increasing importance of nuclear-encoded modular proteins capable of binding nucleic acids and regulating OGE. Mitochondrial transcription termination factor (mTERF) proteins are a good example of this category of OGE regulators. Plant mTERFs are located in chloroplasts and/or mitochondria, and have been characterized mainly from the isolation and analyses of Arabidopsis and maize mutants. These studies have revealed their fundamental roles in different plant development aspects and responses to abiotic stress. Fourteen mTERFs have been hitherto characterized in land plants, albeit to a different extent. These numbers are limited if we consider that 31 and 35 mTERFs have been, respectively, identified in maize and Arabidopsis. Notwithstanding, remarkable progress has been made in recent years to elucidate the molecular mechanisms by which mTERFs regulate OGE. Consequently, it has been experimentally demonstrated that plant mTERFs are required for the transcription termination of chloroplast genes (mTERF6 and mTERF8), transcriptional pausing and the stabilization of chloroplast transcripts (MDA1/mTERF5), intron splicing in chloroplasts (BSM/RUG2/mTERF4 and Zm-mTERF4) and mitochondria (mTERF15 and ZmSMK3) and very recently, also in the assembly of chloroplast ribosomes and translation (mTERF9). This review aims to provide a detailed update of current knowledge about the molecular functions of plant mTERF proteins. It principally focuses on new research that has made an outstanding contribution to unravel the molecular mechanisms by which plant mTERFs regulate the expression of chloroplast and mitochondrial genomes.
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Yang Q, Fu GF, Wu ZQ, Li L, Zhao JL, Li QJ. Chloroplast Genome Evolution in Four Montane Zingiberaceae Taxa in China. FRONTIERS IN PLANT SCIENCE 2021; 12:774482. [PMID: 35082807 PMCID: PMC8784687 DOI: 10.3389/fpls.2021.774482] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 11/08/2021] [Indexed: 05/11/2023]
Abstract
Chloroplasts are critical to plant survival and adaptive evolution. The comparison of chloroplast genomes could provide insight into the adaptive evolution of closely related species. To identify potential adaptive evolution in the chloroplast genomes of four montane Zingiberaceae taxa (Cautleya, Roscoea, Rhynchanthus, and Pommereschea) that inhabit distinct habitats in the mountains of Yunnan, China, the nucleotide sequences of 13 complete chloroplast genomes, including five newly sequenced species, were characterized and compared. The five newly sequenced chloroplast genomes (162,878-163,831 bp) possessed typical quadripartite structures, which included a large single copy (LSC) region, a small single copy (SSC) region, and a pair of inverted repeat regions (IRa and IRb), and even though the structure was highly conserved among the 13 taxa, one of the rps19 genes was absent in Cautleya, possibly due to expansion of the LSC region. Positive selection of rpoA and ycf2 suggests that these montane species have experienced adaptive evolution to habitats with different sunlight intensities and that adaptation related to the chloroplast genome has played an important role in the evolution of Zingiberaceae taxa.
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Affiliation(s)
- Qian Yang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, School of Ecology and Environmental Science, Yunnan University, Kunming, China
| | - Gao-Fei Fu
- Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Zhi-Qiang Wu
- Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Li Li
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, School of Ecology and Environmental Science, Yunnan University, Kunming, China
| | - Jian-Li Zhao
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, School of Ecology and Environmental Science, Yunnan University, Kunming, China
- *Correspondence: Jian-Li Zhao,
| | - Qing-Jun Li
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, School of Ecology and Environmental Science, Yunnan University, Kunming, China
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Li T, Pan W, Yuan Y, Liu Y, Li Y, Wu X, Wang F, Cui L. Identification, Characterization, and Expression Profile Analysis of the mTERF Gene Family and Its Role in the Response to Abiotic Stress in Barley ( Hordeum vulgare L.). FRONTIERS IN PLANT SCIENCE 2021; 12:684619. [PMID: 34335653 PMCID: PMC8319850 DOI: 10.3389/fpls.2021.684619] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 06/23/2021] [Indexed: 05/17/2023]
Abstract
Plant mitochondrial transcription termination factor (mTERF) family regulates organellar gene expression (OGE) and is functionally characterized in diverse species. However, limited data are available about its functions in the agriculturally important cereal barley (Hordeum vulgare L.). In this study, we identified 60 mTERFs in the barley genome (HvmTERFs) through a comprehensive search against the most updated barley reference genome, Morex V2. Then, phylogenetic analysis categorized these genes into nine subfamilies, with approximately half of the HvmTERFs belonging to subfamily IX. Members within the same subfamily generally possessed conserved motif composition and exon-intron structure. Both segmental and tandem duplication contributed to the expansion of HvmTERFs, and the duplicated gene pairs were subjected to strong purifying selection. Expression analysis suggested that many HvmTERFs may play important roles in barley development (e.g., seedlings, leaves, and developing inflorescences) and abiotic stresses (e.g., cold, salt, and metal ion), and HvmTERF21 and HvmTERF23 were significant induced by various abiotic stresses and/or phytohormone treatment. Finally, the nucleotide diversity was decreased by only 4.5% for HvmTERFs during the process of barley domestication. Collectively, this is the first report to characterize HvmTERFs, which will not only provide important insights into further evolutionary studies but also contribute to a better understanding of the potential functions of HvmTERFs and ultimately will be useful in future gene functional studies.
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Affiliation(s)
- Tingting Li
- College of Bioscience and Engineering, Jiangxi Agricultural University, Nanchang, China
| | - Wenqiu Pan
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Agronomy, Northwest A&F University, Yangling, China
| | - Yiyuan Yuan
- College of Bioscience and Engineering, Jiangxi Agricultural University, Nanchang, China
| | - Ying Liu
- College of Bioscience and Engineering, Jiangxi Agricultural University, Nanchang, China
| | - Yihan Li
- College of Bioscience and Engineering, Jiangxi Agricultural University, Nanchang, China
| | - Xiaoyu Wu
- College of Bioscience and Engineering, Jiangxi Agricultural University, Nanchang, China
| | - Fei Wang
- College of Bioscience and Engineering, Jiangxi Agricultural University, Nanchang, China
| | - Licao Cui
- College of Bioscience and Engineering, Jiangxi Agricultural University, Nanchang, China
- *Correspondence: Licao Cui
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Méteignier L, Ghandour R, Meierhoff K, Zimmerman A, Chicher J, Baumberger N, Alioua A, Meurer J, Zoschke R, Hammani K. The Arabidopsis mTERF-repeat MDA1 protein plays a dual function in transcription and stabilization of specific chloroplast transcripts within the psbE and ndhH operons. THE NEW PHYTOLOGIST 2020; 227:1376-1391. [PMID: 32343843 PMCID: PMC7496394 DOI: 10.1111/nph.16625] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 04/15/2020] [Indexed: 05/28/2023]
Abstract
The mTERF gene family encodes for nucleic acid binding proteins that are predicted to regulate organellar gene expression in eukaryotes. Despite the implication of this gene family in plant development and response to abiotic stresses, a precise molecular function was assigned to only a handful number of its c. 30 members in plants. Using a reverse genetics approach in Arabidopsis thaliana and combining molecular and biochemical techniques, we revealed new functions for the chloroplast mTERF protein, MDA1. We demonstrated that MDA1 associates in vivo with components of the plastid-encoded RNA polymerase and transcriptional active chromosome complexes. MDA1 protein binds in vivo and in vitro with specificity to 27-bp DNA sequences near the 5'-end of psbE and ndhA chloroplast genes to stimulate their transcription, and additionally promotes the stabilization of the 5'-ends of processed psbE and ndhA messenger (m)RNAs. Finally, we provided evidence that MDA1 function in gene transcription likely coordinates RNA folding and the action of chloroplast RNA-binding proteins on mRNA stabilization. Our results provide examples for the unexpected implication of DNA binding proteins and gene transcription in the regulation of mRNA stability in chloroplasts, blurring the boundaries between DNA and RNA metabolism in this organelle.
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Affiliation(s)
- Louis‐Valentin Méteignier
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
| | - Rabea Ghandour
- Max Planck Institute of Molecular Plant PhysiologyAm Mühlenberg 114476Potsdam‐GolmGermany
| | - Karin Meierhoff
- Institute of Developmental and Molecular Biology of PlantsHeinrich Heine University Düsseldorf40225DüsseldorfGermany
| | - Aude Zimmerman
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
| | - Johana Chicher
- Plateforme protéomique Strasbourg Esplanade FRC1589 du CNRSUniversité de Strasbourg15 rue René Descartes67084StrasbourgFrance
| | - Nicolas Baumberger
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
| | - Abdelmalek Alioua
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
| | - Jörg Meurer
- Plant SciencesFaculty of BiologyLudwig‐Maximilians‐University MunichGroßhaderner Street 2‐482152Planegg‐MartinsriedGermany
| | - Reimo Zoschke
- Max Planck Institute of Molecular Plant PhysiologyAm Mühlenberg 114476Potsdam‐GolmGermany
| | - Kamel Hammani
- Institut de Biologie Moléculaire des PlantesCentre National de la Recherche Scientifique (CNRS)Université de Strasbourg12 rue du Général Zimmer67084StrasbourgFrance
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Mehmood F, Abdullah, Ubaid Z, Shahzadi I, Ahmed I, Waheed MT, Poczai P, Mirza B. Plastid genomics of Nicotiana (Solanaceae): insights into molecular evolution, positive selection and the origin of the maternal genome of Aztec tobacco ( Nicotiana rustica). PeerJ 2020; 8:e9552. [PMID: 32775052 PMCID: PMC7382938 DOI: 10.7717/peerj.9552] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 06/24/2020] [Indexed: 12/17/2022] Open
Abstract
Species of the genus Nicotiana (Solanaceae), commonly referred to as tobacco plants, are often cultivated as non-food crops and garden ornamentals. In addition to the worldwide production of tobacco leaves, they are also used as evolutionary model systems due to their complex development history tangled by polyploidy and hybridization. Here, we assembled the plastid genomes of five tobacco species: N. knightiana, N. rustica, N. paniculata, N. obtusifolia and N. glauca. De novo assembled tobacco plastid genomes had the typical quadripartite structure, consisting of a pair of inverted repeat (IR) regions (25,323-25,369 bp each) separated by a large single-copy (LSC) region (86,510-86,716 bp) and a small single-copy (SSC) region (18,441-18,555 bp). Comparative analyses of Nicotiana plastid genomes with currently available Solanaceae genome sequences showed similar GC and gene content, codon usage, simple sequence and oligonucleotide repeats, RNA editing sites, and substitutions. We identified 20 highly polymorphic regions, mostly belonging to intergenic spacer regions (IGS), which could be suitable for the development of robust and cost-effective markers for inferring the phylogeny of the genus Nicotiana and family Solanaceae. Our comparative plastid genome analysis revealed that the maternal parent of the tetraploid N. rustica was the common ancestor of N. paniculata and N. knightiana, and the later species is more closely related to N. rustica. Relaxed molecular clock analyses estimated the speciation event between N. rustica and N. knightiana appeared 0.56 Ma (HPD 0.65-0.46). Biogeographical analysis supported a south-to-north range expansion and diversification for N. rustica and related species, where N. undulata and N. paniculata evolved in North/Central Peru, while N. rustica developed in Southern Peru and separated from N. knightiana, which adapted to the Southern coastal climatic regimes. We further inspected selective pressure on protein-coding genes among tobacco species to determine if this adaptation process affected the evolution of plastid genes. These analyses indicate that four genes involved in different plastid functions, including DNA replication (rpoA) and photosynthesis (atpB, ndhD and ndhF), came under positive selective pressure as a result of specific environmental conditions. Genetic mutations in these genes might have contributed to better survival and superior adaptations during the evolutionary history of tobacco species.
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Affiliation(s)
- Furrukh Mehmood
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
- Botany Unit, Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - Abdullah
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Zartasha Ubaid
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Iram Shahzadi
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Ibrar Ahmed
- Alpha Genomics Private Limited, Islamabad, Pakistan
| | - Mohammad Tahir Waheed
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Peter Poczai
- Botany Unit, Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - Bushra Mirza
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
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Lidón-Soto A, Núñez-Delegido E, Pastor-Martínez I, Robles P, Quesada V. Arabidopsis Plastid-RNA Polymerase RPOTp Is Involved in Abiotic Stress Tolerance. PLANTS (BASEL, SWITZERLAND) 2020; 9:E834. [PMID: 32630785 PMCID: PMC7412009 DOI: 10.3390/plants9070834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 06/25/2020] [Accepted: 06/29/2020] [Indexed: 05/05/2023]
Abstract
Plastid gene expression (PGE) must adequately respond to changes in both development and environmental cues. The transcriptional machinery of plastids in land plants is far more complex than that of prokaryotes. Two types of DNA-dependent RNA polymerases transcribe the plastid genome: a multimeric plastid-encoded polymerase (PEP), and a monomeric nuclear-encoded polymerase (NEP). A single NEP in monocots (RPOTp, RNA polymerase of the T3/T7 phage-type) and two NEPs in dicots (plastid-targeted RPOTp, and plastid- and mitochondrial-targeted RPOTmp) have been hitherto identified. To unravel the role of PGE in plant responses to abiotic stress, we investigated if Arabidopsis RPOTp could function in plant salt tolerance. To this end, we studied the sensitivity of T-DNA mutants scabra3-2 (sca3-2) and sca3-3, defective in the RPOTp gene, to salinity, osmotic stress and the phytohormone abscisic acid (ABA) required for plants to adapt to abiotic stress. sca3 mutants were hypersensitive to NaCl, mannitol and ABA during germination and seedling establishment. Later in development, sca3 plants displayed reduced sensitivity to salt stress. A gene ontology (GO) analysis of the nuclear genes differentially expressed in the sca3-2 mutant (301) revealed that many significantly enriched GO terms were related to chloroplast function, and also to the response to several abiotic stresses. By quantitative RT-PCR (qRT-PCR), we found that genes LHCB1 (LIGHT-HARVESTING CHLOROPHYLL a/b-BINDING1) and AOX1A (ALTERNATIVE OXIDASE 1A) were respectively down- and up-regulated in the Columbia-0 (Col-0) salt-stressed plants, which suggests the activation of plastid and mitochondria-to-nucleus retrograde signaling. The transcript levels of genes RPOTp, RPOTmp and RPOTm significantly increased in these salt-stressed seedlings, but this enhanced expression did not lead to the up-regulation of the plastid genes solely transcribed by NEP. Similar to salinity, carotenoid inhibitor norflurazon (NF) also enhanced the RPOTp transcript levels in Col-0 seedlings. This shows that besides salinity, inhibition of chloroplast biogenesis also induces RPOTp expression. Unlike salt and NF, the NEP genes were significantly down-regulated in the Col-0 seedlings grown in ABA-supplemented media. Together, our findings demonstrate that RPOTp functions in abiotic stress tolerance, and RPOTp is likely regulated positively by plastid-to-nucleus retrograde signaling, which is triggered when chloroplast functionality is perturbed by environmental stresses, e.g., salinity or NF. This suggests the existence of a compensatory mechanism, elicited by impaired chloroplast function. To our knowledge, this is the first study to suggest the role of a nuclear-encoded plastid-RNA polymerase in salt stress tolerance in plants.
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Affiliation(s)
| | | | | | | | - Víctor Quesada
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain; (A.L.-S.); (E.N.-D.); (I.P.-M.); (P.R.)
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Leister D, Kleine T. Extending the Repertoire of mTERF Proteins with Functions in Organellar Gene Expression. MOLECULAR PLANT 2020; 13:817-819. [PMID: 32298787 DOI: 10.1016/j.molp.2020.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 05/16/2023]
Affiliation(s)
- Dario Leister
- Plant Molecular Biology (Botany), Department of Biology I, Ludwig-Maximilians-University München, 82152 Martinsried, Germany
| | - Tatjana Kleine
- Plant Molecular Biology (Botany), Department of Biology I, Ludwig-Maximilians-University München, 82152 Martinsried, Germany.
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Castandet B, Germain A, Hotto AM, Stern DB. Systematic sequencing of chloroplast transcript termini from Arabidopsis thaliana reveals >200 transcription initiation sites and the extensive imprints of RNA-binding proteins and secondary structures. Nucleic Acids Res 2020; 47:11889-11905. [PMID: 31732725 PMCID: PMC7145512 DOI: 10.1093/nar/gkz1059] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 10/02/2019] [Accepted: 11/05/2019] [Indexed: 12/23/2022] Open
Abstract
Chloroplast transcription requires numerous quality control steps to generate the complex but selective mixture of accumulating RNAs. To gain insight into how this RNA diversity is achieved and regulated, we systematically mapped transcript ends by developing a protocol called Terminome-seq. Using Arabidopsis thaliana as a model, we catalogued >215 primary 5′ ends corresponding to transcription start sites (TSS), as well as 1628 processed 5′ ends and 1299 3′ ends. While most termini were found in intergenic regions, numerous abundant termini were also found within coding regions and introns, including several major TSS at unexpected locations. A consistent feature was the clustering of both 5′ and 3′ ends, contrasting with the prevailing description of discrete 5′ termini, suggesting an imprecision of the transcription and/or RNA processing machinery. Numerous termini correlated with the extremities of small RNA footprints or predicted stem-loop structures, in agreement with the model of passive RNA protection. Terminome-seq was also implemented for pnp1–1, a mutant lacking the processing enzyme polynucleotide phosphorylase. Nearly 2000 termini were altered in pnp1–1, revealing a dominant role in shaping the transcriptome. In summary, Terminome-seq permits precise delineation of the roles and regulation of the many factors involved in organellar transcriptome quality control.
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Affiliation(s)
- Benoît Castandet
- Boyce Thompson Institute, Ithaca, NY 14853, USA.,Institut des Sciences des Plantes de Paris Saclay (IPS2), UEVE, INRA, CNRS, Univ. Paris Sud, Université Paris-Saclay, F-91192 Gif sur Yvette, France.,Université de Paris, IPS2, F-91192 Gif sur Yvette, France
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Núñez-Delegido E, Robles P, Ferrández-Ayela A, Quesada V. Functional analysis of mTERF5 and mTERF9 contribution to salt tolerance, plastid gene expression and retrograde signalling in Arabidopsis thaliana. PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22:459-471. [PMID: 31850621 DOI: 10.1111/plb.13084] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 12/06/2019] [Indexed: 05/16/2023]
Abstract
We previously showed that Arabidopsis mda1 and mterf9 mutants, defective in the chloroplast-targeted mitochondrial transcription termination factors mTERF5 and mTERF9, respectively, display altered responses to abiotic stresses and abscisic acid (ABA), as well as perturbed development, likely through abnormal chloroplast biogenesis. To advance the functional analysis of mTERF5 and mTERF9, we obtained and characterized overexpression (OE) lines. Additionally, we studied genetic interactions between sca3-2, affected in the plastid-RNA polymerase RpoTp, and the mda1-1 and mterf9 mutations. We also investigated the role of mTERF5 and mTERF9 in plastid translation and plastid-to-nucleus signalling. We found that mTERF9 OE reduces salt and ABA tolerance, while mTERF5 or mTERF9 OE alter expression of nuclear and plastid genes. We determined that mda1-1 and mterf9 mutations genetically interact with sca3-2. Further, plastid 16S rRNA levels were reduced in mda1-1 and mterf9 mutants, and mterf9 was more sensitive to chemical inhibitors of chloroplast translation. Expression of the photosynthesis gene LHCB1, a retrograde signalling marker, was differentially affected in mda1-1 and/or mterf9 compared to wild-type Col-0, after treatments with inhibitors of carotenoid biosynthesis (norflurazon) or chloroplast translation (lincomycin). Moreover, mterf9, but not mda1-1, synergistically interacts with gun1-1, defective in GUN1, a central integrator of plastid retrograde signals. Our results show that mTERF9, and to a lesser extent mTERF5, are negative regulators of salt tolerance and that both genes are functionally related to RpoTp, and that mTERF9 is likely required for plastid ribosomal stability and/or assembly. Furthermore, our findings support a role for mTERF9 in retrograde signalling.
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Affiliation(s)
- E Núñez-Delegido
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain
| | - P Robles
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain
| | - A Ferrández-Ayela
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain
| | - V Quesada
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain
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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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Xiong HB, Wang J, Huang C, Rochaix JD, Lin FM, Zhang JX, Ye LS, Shi XH, Yu QB, Yang ZN. mTERF8, a Member of the Mitochondrial Transcription Termination Factor Family, Is Involved in the Transcription Termination of Chloroplast Gene psbJ. PLANT PHYSIOLOGY 2020; 182:408-423. [PMID: 31685645 PMCID: PMC6945865 DOI: 10.1104/pp.19.00906] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 10/21/2019] [Indexed: 05/28/2023]
Abstract
Members of the mitochondrial transcription terminator factor (mTERF) family, originally identified in vertebrate mitochondria, are involved in the termination of organellular transcription. In plants, mTERF proteins are mainly localized in chloroplasts and mitochondria. In Arabidopsis (Arabidopsis thaliana), mTERF8/pTAC15 was identified in the plastid-encoded RNA polymerase (PEP) complex, the major RNA polymerase of chloroplasts. In this work, we demonstrate that mTERF8 is associated with the PEP complex. An mTERF8 knockout line displayed a wild-type-like phenotype under standard growth conditions, but showed impaired efficiency of photosystem II electron flow. Transcription of most chloroplast genes was not substantially affected in the mterf8 mutant; however, the level of the psbJ transcript from the psbEFLJ polycistron was increased. RNA blot analysis showed that a larger transcript accumulates in mterf8 than in the wild type. Thus, abnormal transcription and/or RNA processing occur for the psbEFLJ polycistron. Circular reverse transcription PCR and sequence analysis showed that the psbJ transcript terminates 95 nucleotides downstream of the translation stop codon in the wild type, whereas its termination is aberrant in mterf8 Both electrophoresis mobility shift assays and chloroplast chromatin immunoprecipitation analysis showed that mTERF8 specifically binds to the 3' terminal region of psbJ Transcription analysis using the in vitro T7 RNA polymerase system showed that mTERF8 terminates psbJ transcription. Together, these results suggest that mTERF8 is specifically involved in the transcription termination of the chloroplast gene psbJ.
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Affiliation(s)
- Hai-Bo Xiong
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Jing Wang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Chao Huang
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China
| | - Jean-David Rochaix
- Departments of Molecular Biology and Plant Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Fei-Min Lin
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Jia-Xing Zhang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Lin-Shan Ye
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Xiao-He Shi
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Qing-Bo Yu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Zhong-Nan Yang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
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23
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Genome-Wide Identification and Characterization of the Mitochondrial Transcription Termination Factors (mTERFs) in Capsicum annuum L. Int J Mol Sci 2019; 21:ijms21010269. [PMID: 31906076 PMCID: PMC6982079 DOI: 10.3390/ijms21010269] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/26/2019] [Accepted: 12/28/2019] [Indexed: 12/16/2022] Open
Abstract
Mitochondrial transcription termination factors (mTERFs) regulate the expression of mitochondrial genes and are closely related to the function of the mitochondrion and chloroplast. In this study, the mTERF gene family in capsicum (Capsicum annuum L.) was identified and characterized through genomic and bioinformatic analyses. Capsicum was found to possess at least 35 mTERF genes (CamTERFs), which were divided into eight major groups following phylogenetic analysis. Analysis of CamTERF promoters revealed the presence of many cis-elements related to the regulation of cellular respiration and photosynthesis. In addition, CamTERF promoters contained cis-elements related to phytohormone regulation and stress responses. Differentially expressed genes in different tissues and developmental phases were identified using RNA-seq data, which revealed that CamTERFs exhibit various expression and co-expression patterns. Gene ontology (GO) annotations associated CamTERFs primarily with mitochondrion and chloroplast function and composition. These results contribute towards understanding the role of mTERFs in capsicum growth, development, and stress responses. Moreover, our data assist in the identification of CamTERFs with important functions, which opens avenues for future studies.
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24
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Ding S, Zhang Y, Hu Z, Huang X, Zhang B, Lu Q, Wen X, Wang Y, Lu C. mTERF5 Acts as a Transcriptional Pausing Factor to Positively Regulate Transcription of Chloroplast psbEFLJ. MOLECULAR PLANT 2019; 12:1259-1277. [PMID: 31128276 DOI: 10.1016/j.molp.2019.05.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 04/22/2019] [Accepted: 05/16/2019] [Indexed: 05/21/2023]
Abstract
RNA polymerase transcriptional pausing represents a major checkpoint in transcription in bacteria and metazoans, but it is unknown whether this phenomenon occurs in plant organelles. Here, we report that transcriptional pausing occurs in chloroplasts. We found that mTERF5 specifically and positively regulates the transcription of chloroplast psbEFLJ in Arabidopsis thaliana that encodes four key subunits of photosystem II. We found that mTERF5 causes the plastid-encoded RNA polymerase (PEP) complex to pause at psbEFLJ by binding to the +30 to +51 region of double-stranded DNA. Moreover, we revealed that mTERF5 interacts with pTAC6, an essential subunit of the PEP complex, although pTAC6 is not involved in the transcriptional pausing at psbEFLJ. We showed that mTERF5 recruits additional pTAC6 to the transcriptionally paused region of psbEFLJ, and the recruited pTAC6 proteins could be assembled into the PEP complex to regulate psbEFLJ transcription. Taken together, our findings shed light on the role of transcriptional pausing in chloroplast transcription in plants.
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Affiliation(s)
- Shunhua Ding
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Yi Zhang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhi Hu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiahe Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bohan Zhang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingtao Lu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Xiaogang Wen
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Yingchun Wang
- University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Congming Lu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China.
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Robles P, Quesada V. Transcriptional and Post-transcriptional Regulation of Organellar Gene Expression (OGE) and Its Roles in Plant Salt Tolerance. Int J Mol Sci 2019; 20:E1056. [PMID: 30823472 PMCID: PMC6429081 DOI: 10.3390/ijms20051056] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 02/21/2019] [Accepted: 02/25/2019] [Indexed: 12/26/2022] Open
Abstract
Given their endosymbiotic origin, chloroplasts and mitochondria genomes harbor only between 100 and 200 genes that encode the proteins involved in organellar gene expression (OGE), photosynthesis, and the electron transport chain. However, as the activity of these organelles also needs a few thousand proteins encoded by the nuclear genome, a close coordination of the gene expression between the nucleus and organelles must exist. In line with this, OGE regulation is crucial for plant growth and development, and is achieved mainly through post-transcriptional mechanisms performed by nuclear genes. In this way, the nucleus controls the activity of organelles and these, in turn, transmit information about their functional state to the nucleus by modulating nuclear expression according to the organelles' physiological requirements. This adjusts organelle function to plant physiological, developmental, or growth demands. Therefore, OGE must appropriately respond to both the endogenous signals and exogenous environmental cues that can jeopardize plant survival. As sessile organisms, plants have to respond to adverse conditions to acclimate and adapt to them. Salinity is a major abiotic stress that negatively affects plant development and growth, disrupts chloroplast and mitochondria function, and leads to reduced yields. Information on the effects that the disturbance of the OGE function has on plant tolerance to salinity is still quite fragmented. Nonetheless, many plant mutants which display altered responses to salinity have been characterized in recent years, and interestingly, several are affected in nuclear genes encoding organelle-localized proteins that regulate the expression of organelle genes. These results strongly support a link between OGE and plant salt tolerance, likely through retrograde signaling. Our review analyzes recent findings on the OGE functions required by plants to respond and tolerate salinity, and highlights the fundamental role that chloroplast and mitochondrion homeostasis plays in plant adaptation to salt stress.
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Affiliation(s)
- Pedro Robles
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain.
| | - Víctor Quesada
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain.
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