1
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Sigal M, Matsumoto S, Beattie A, Katoh T, Suga H. Engineering tRNAs for the Ribosomal Translation of Non-proteinogenic Monomers. Chem Rev 2024; 124:6444-6500. [PMID: 38688034 PMCID: PMC11122139 DOI: 10.1021/acs.chemrev.3c00894] [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: 12/01/2023] [Revised: 02/21/2024] [Accepted: 04/10/2024] [Indexed: 05/02/2024]
Abstract
Ribosome-dependent protein biosynthesis is an essential cellular process mediated by transfer RNAs (tRNAs). Generally, ribosomally synthesized proteins are limited to the 22 proteinogenic amino acids (pAAs: 20 l-α-amino acids present in the standard genetic code, selenocysteine, and pyrrolysine). However, engineering tRNAs for the ribosomal incorporation of non-proteinogenic monomers (npMs) as building blocks has led to the creation of unique polypeptides with broad applications in cellular biology, material science, spectroscopy, and pharmaceuticals. Ribosomal polymerization of these engineered polypeptides presents a variety of challenges for biochemists, as translation efficiency and fidelity is often insufficient when employing npMs. In this Review, we will focus on the methodologies for engineering tRNAs to overcome these issues and explore recent advances both in vitro and in vivo. These efforts include increasing orthogonality, recruiting essential translation factors, and creation of expanded genetic codes. After our review on the biochemical optimizations of tRNAs, we provide examples of their use in genetic code manipulation, with a focus on the in vitro discovery of bioactive macrocyclic peptides containing npMs. Finally, an analysis of the current state of tRNA engineering is presented, along with existing challenges and future perspectives for the field.
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Affiliation(s)
- Maxwell Sigal
- Department of Chemistry,
Graduate School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Satomi Matsumoto
- Department of Chemistry,
Graduate School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Adam Beattie
- Department of Chemistry,
Graduate School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takayuki Katoh
- Department of Chemistry,
Graduate School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroaki Suga
- Department of Chemistry,
Graduate School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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2
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Khomarbaghi Z, Ngan WY, Ayan GB, Lim S, Dechow-Seligmann G, Nandy P, Gallie J. Large-scale duplication events underpin population-level flexibility in tRNA gene copy number in Pseudomonas fluorescens SBW25. Nucleic Acids Res 2024; 52:2446-2462. [PMID: 38296823 PMCID: PMC10954465 DOI: 10.1093/nar/gkae049] [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: 12/19/2022] [Revised: 01/10/2024] [Accepted: 01/15/2024] [Indexed: 02/02/2024] Open
Abstract
The complement of tRNA genes within a genome is typically considered to be a (relatively) stable characteristic of an organism. Here, we demonstrate that bacterial tRNA gene set composition can be more flexible than previously appreciated, particularly regarding tRNA gene copy number. We report the high-rate occurrence of spontaneous, large-scale, tandem duplication events in laboratory populations of the bacterium Pseudomonas fluorescens SBW25. The identified duplications are up to ∼1 Mb in size (∼15% of the wildtype genome) and are predicted to change the copy number of up to 917 genes, including several tRNA genes. The observed duplications are inherently unstable: they occur, and are subsequently lost, at extremely high rates. We propose that this unusually plastic type of mutation provides a mechanism by which tRNA gene set diversity can be rapidly generated, while simultaneously preserving the underlying tRNA gene set in the absence of continued selection. That is, if a tRNA set variant provides no fitness advantage, then high-rate segregation of the duplication ensures the maintenance of the original tRNA gene set. However, if a tRNA gene set variant is beneficial, the underlying duplication fragment(s) may persist for longer and provide raw material for further, more stable, evolutionary change.
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Affiliation(s)
- Zahra Khomarbaghi
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Wing Y Ngan
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Gökçe B Ayan
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Sungbin Lim
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Gunda Dechow-Seligmann
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Pabitra Nandy
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Jenna Gallie
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
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3
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Kompatscher M, Bartosik K, Erharter K, Plangger R, Juen F, Kreutz C, Micura R, Westhof E, Erlacher M. Contribution of tRNA sequence and modifications to the decoding preferences of E. coli and M. mycoides tRNAGlyUCC for synonymous glycine codons. Nucleic Acids Res 2024; 52:1374-1386. [PMID: 38050960 PMCID: PMC10853795 DOI: 10.1093/nar/gkad1136] [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: 09/13/2023] [Revised: 11/06/2023] [Accepted: 11/10/2023] [Indexed: 12/07/2023] Open
Abstract
tRNA superwobbling, used by certain bacteria and organelles, is an intriguing decoding concept in which a single tRNA isoacceptor is used to decode all synonymous codons of a four-fold degenerate codon box. While Escherichia coli relies on three tRNAGly isoacceptors to decode the four glycine codons (GGN), Mycoplasma mycoides requires only a single tRNAGly. Both organisms express tRNAGly with the anticodon UCC, which are remarkably similar in sequence but different in their decoding ability. By systematically introducing mutations and altering the number and type of tRNA modifications using chemically synthesized tRNAs, we elucidated the contribution of individual nucleotides and chemical groups to decoding by the E. coli and M. mycoides tRNAGly. The tRNA sequence was identified as the key factor for superwobbling, revealing the T-arm sequence as a novel pivotal element. In addition, the presence of tRNA modifications, although not essential for providing superwobbling, was shown to delicately fine-tune and balance the decoding of synonymous codons. This emphasizes that the tRNA sequence and its modifications together form an intricate system of high complexity that is indispensable for accurate and efficient decoding.
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Affiliation(s)
- Maria Kompatscher
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Karolina Bartosik
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Kevin Erharter
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Raphael Plangger
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Fabian Sebastian Juen
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Christoph Kreutz
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Eric Westhof
- Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l’ARN, CNRS UPR 9002, 2, allée Konrad Roentgen, F-67084 Strasbourg, France
| | - Matthias D Erlacher
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
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4
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Lei L, Burton ZF. The 3 31 Nucleotide Minihelix tRNA Evolution Theorem and the Origin of Life. Life (Basel) 2023; 13:2224. [PMID: 38004364 PMCID: PMC10672568 DOI: 10.3390/life13112224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/08/2023] [Accepted: 11/16/2023] [Indexed: 11/26/2023] Open
Abstract
There are no theorems (proven theories) in the biological sciences. We propose that the 3 31 nt minihelix tRNA evolution theorem be universally accepted as one. The 3 31 nt minihelix theorem completely describes the evolution of type I and type II tRNAs from ordered precursors (RNA repeats and inverted repeats). Despite the diversification of tRNAome sequences, statistical tests overwhelmingly support the theorem. Furthermore, the theorem relates the dominant pathway for the origin of life on Earth, specifically, how tRNAomes and the genetic code may have coevolved. Alternate models for tRNA evolution (i.e., 2 minihelix, convergent and accretion models) are falsified. In the context of the pre-life world, tRNA was a molecule that, via mutation, could modify anticodon sequences and teach itself to code. Based on the tRNA sequence, we relate the clearest history to date of the chemical evolution of life. From analysis of tRNA evolution, ribozyme-mediated RNA ligation was a primary driving force in the evolution of complexity during the pre-life-to-life transition. TRNA formed the core for the evolution of living systems on Earth.
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Affiliation(s)
- Lei Lei
- School of Biological Sciences, University of New England, Biddeford, ME 04005, USA;
| | - Zachary Frome Burton
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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5
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Zhang Y, Tian L, Lu C. Chloroplast gene expression: Recent advances and perspectives. PLANT COMMUNICATIONS 2023; 4:100611. [PMID: 37147800 PMCID: PMC10504595 DOI: 10.1016/j.xplc.2023.100611] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 04/11/2023] [Accepted: 05/01/2023] [Indexed: 05/07/2023]
Abstract
Chloroplasts evolved from an ancient cyanobacterial endosymbiont more than 1.5 billion years ago. During subsequent coevolution with the nuclear genome, the chloroplast genome has remained independent, albeit strongly reduced, with its own transcriptional machinery and distinct features, such as chloroplast-specific innovations in gene expression and complicated post-transcriptional processing. Light activates the expression of chloroplast genes via mechanisms that optimize photosynthesis, minimize photodamage, and prioritize energy investments. Over the past few years, studies have moved from describing phases of chloroplast gene expression to exploring the underlying mechanisms. In this review, we focus on recent advances and emerging principles that govern chloroplast gene expression in land plants. We discuss engineering of pentatricopeptide repeat proteins and its biotechnological effects on chloroplast RNA research; new techniques for characterizing the molecular mechanisms of chloroplast gene expression; and important aspects of chloroplast gene expression for improving crop yield and stress tolerance. We also discuss biological and mechanistic questions that remain to be answered in the future.
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Affiliation(s)
- Yi Zhang
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Lin Tian
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Congming Lu
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China.
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6
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Zolyan S. On the minimal elements of the genetic code and their semiotic functions (degeneracy, complementarity, wobbling). Biosystems 2023; 231:104962. [PMID: 37437772 DOI: 10.1016/j.biosystems.2023.104962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 06/17/2023] [Accepted: 06/19/2023] [Indexed: 07/14/2023]
Abstract
We address semiotic features of genetic coding, primarily the mechanisms for distinguishing between triplets. It implies that the minimal elements that allow codon recognition and amino acid coding should be identified. Half a century ago, linguist Roman Jakobson and microbiologist François Jacob revealed functional similarities between nucleotides in the genetic code and phonemes in natural language. Developing this analogy, we introduce the concept of a semiotic nucleotide. Unlike "material" nucleotides, its characteristics are limited to the function of differentiation within the processing of genetic information. We demonstrate that, similarly to phonemes, nucleotides are also non-elementary entities and can be represented as a set of two differential features: a) the number of rings and b) the number of hydrogen bonds. This makes it possible to convert semiotic nucleotides into double-byte units of digital information. Proceeding from this assumption, we suggest a new vision of such phenomena as the heterogeneity of the genetic code in terms of coding types, to reveal the code-distinguishing potential of positions within triplets, and represent wobbling as a specific reading regime. All these phenomena relate to the peculiarity of the triplet's third position, where complete or partial neutralization of distinguishing features is possible.
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Affiliation(s)
- Suren Zolyan
- Immanuel Kant Baltic Federal University, Kaliningrad, Russia; Institute of Scientific Information on Social Sciences of the Russian Academy of Sciences, Moscow, Russia.
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7
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Soma A, Kubota A, Tomoe D, Ikeuchi Y, Kawamura F, Arimoto H, Shiwa Y, Kanesaki Y, Nanamiya H, Yoshikawa H, Suzuki T, Sekine Y. yaaJ, the tRNA-Specific Adenosine Deaminase, Is Dispensable in Bacillus subtilis. Genes (Basel) 2023; 14:1515. [PMID: 37628567 PMCID: PMC10454642 DOI: 10.3390/genes14081515] [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: 06/12/2023] [Revised: 07/11/2023] [Accepted: 07/20/2023] [Indexed: 08/27/2023] Open
Abstract
Post-transcriptional modifications of tRNA are crucial for their core function. The inosine (I; 6-deaminated adenosine) at the first position in the anticodon of tRNAArg(ICG) modulates the decoding capability and is generally considered essential for reading CGU, CGC, and CGA codons in eubacteria. We report here that the Bacillus subtilis yaaJ gene encodes tRNA-specific adenosine deaminase and is non-essential for viability. A β-galactosidase reporter assay revealed that the translational activity of CGN codons was not impaired in the yaaJ-deletion mutant. Furthermore, tRNAArg(CCG) responsible for decoding the CGG codon was dispensable, even in the presence or absence of yaaJ. These results strongly suggest that tRNAArg with either the anticodon ICG or ACG has an intrinsic ability to recognize all four CGN codons, providing a fundamental concept of non-canonical wobbling mediated by adenosine and inosine nucleotides in the anticodon. This is the first example of the four-way wobbling by inosine nucleotide in bacterial cells. On the other hand, the absence of inosine modification induced +1 frameshifting, especially at the CGA codon. Additionally, the yaaJ deletion affected growth and competency. Therefore, the inosine modification is beneficial for translational fidelity and proper growth-phase control, and that is why yaaJ has been actually conserved in B. subtilis.
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Affiliation(s)
- Akiko Soma
- Graduate School of Horticulture, Chiba University, 648 Matsudo, Chiba 271-8510, Japan
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
| | - Atsushi Kubota
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
| | - Daisuke Tomoe
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
| | - Yoshiho Ikeuchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Fujio Kawamura
- Graduate School of Horticulture, Chiba University, 648 Matsudo, Chiba 271-8510, Japan
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
| | - Hijiri Arimoto
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
| | - Yuh Shiwa
- NODAI Genome Research Center, Tokyo University of Agriculture, Tokyo 156-8502, Japan
- Department of Molecular Microbiology, Tokyo University of Agriculture, Tokyo 156-8502, Japan
| | - Yu Kanesaki
- Shizuoka Instrumental Analysis Center, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Hideaki Nanamiya
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
- Fukushima Translational Research Foundation, Capital Front Bldg., 7-4, 1-35, Sakae-machi, Fukushima 960-8031, Japan
| | - Hirofumi Yoshikawa
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Yasuhiko Sekine
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
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8
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Small I, Melonek J, Bohne AV, Nickelsen J, Schmitz-Linneweber C. Plant organellar RNA maturation. THE PLANT CELL 2023; 35:1727-1751. [PMID: 36807982 PMCID: PMC10226603 DOI: 10.1093/plcell/koad049] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/05/2023] [Accepted: 01/17/2023] [Indexed: 05/30/2023]
Abstract
Plant organellar RNA metabolism is run by a multitude of nucleus-encoded RNA-binding proteins (RBPs) that control RNA stability, processing, and degradation. In chloroplasts and mitochondria, these post-transcriptional processes are vital for the production of a small number of essential components of the photosynthetic and respiratory machinery-and consequently for organellar biogenesis and plant survival. Many organellar RBPs have been functionally assigned to individual steps in RNA maturation, often specific to selected transcripts. While the catalog of factors identified is ever-growing, our knowledge of how they achieve their functions mechanistically is far from complete. This review summarizes the current knowledge of plant organellar RNA metabolism taking an RBP-centric approach and focusing on mechanistic aspects of RBP functions and the kinetics of the processes they are involved in.
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Affiliation(s)
- Ian Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley 6009, Australia
| | - Joanna Melonek
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley 6009, Australia
| | | | - Jörg Nickelsen
- Department of Molecular Plant Sciences, LMU Munich, 82152 Martinsried, Germany
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9
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Cavallin I, Bartosovic M, Skalicky T, Rengaraj P, Demko M, Schmidt-Dengler MC, Drino A, Helm M, Vanacova S. HITS-CLIP analysis of human ALKBH8 reveals interactions with fully processed substrate tRNAs and with specific noncoding RNAs. RNA (NEW YORK, N.Y.) 2022; 28:1568-1581. [PMID: 36192131 PMCID: PMC9670814 DOI: 10.1261/rna.079421.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/09/2022] [Indexed: 06/16/2023]
Abstract
Transfer RNAs acquire a large plethora of chemical modifications. Among those, modifications of the anticodon loop play important roles in translational fidelity and tRNA stability. Four human wobble U-containing tRNAs obtain 5-methoxycarbonylmethyluridine (mcm5U34) or 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U34), which play a role in decoding. This mark involves a cascade of enzymatic activities. The last step is mediated by alkylation repair homolog 8 (ALKBH8). In this study, we performed a transcriptome-wide analysis of the repertoire of ALKBH8 RNA targets. Using a combination of HITS-CLIP and RIP-seq analyses, we uncover ALKBH8-bound RNAs. We show that ALKBH8 targets fully processed and CCA modified tRNAs. Our analyses uncovered the previously known set of wobble U-containing tRNAs. In addition, both our approaches revealed ALKBH8 binding to several other types of noncoding RNAs, in particular C/D box snoRNAs.
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Affiliation(s)
- Ivana Cavallin
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
| | - Marek Bartosovic
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
| | - Tomas Skalicky
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czech Republic
| | - Praveenkumar Rengaraj
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
| | - Martin Demko
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
| | | | - Aleksej Drino
- Medical University of Vienna, Center for Anatomy and Cell Biology, 1090 Vienna, Austria
| | - Mark Helm
- Johannes Gutenberg-Universität Mainz, Institute of Pharmaceutical and Biomedical Science (IPBS), D-55128 Mainz, Germany
| | - Stepanka Vanacova
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
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10
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Fages‐Lartaud M, Hundvin K, Hohmann‐Marriott MF. Mechanisms governing codon usage bias and the implications for protein expression in the chloroplast of Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 112:919-945. [PMID: 36071273 PMCID: PMC9828097 DOI: 10.1111/tpj.15970] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 08/29/2022] [Accepted: 09/01/2022] [Indexed: 05/30/2023]
Abstract
Chloroplasts possess a considerably reduced genome that is decoded via an almost minimal set of tRNAs. These features make an excellent platform for gaining insights into fundamental mechanisms that govern protein expression. Here, we present a comprehensive and revised perspective of the mechanisms that drive codon selection in the chloroplast of Chlamydomonas reinhardtii and the functional consequences for protein expression. In order to extract this information, we applied several codon usage descriptors to genes with different expression levels. We show that highly expressed genes strongly favor translationally optimal codons, while genes with lower functional importance are rather affected by directional mutational bias. We demonstrate that codon optimality can be deduced from codon-anticodon pairing affinity and, for a small number of amino acids (leucine, arginine, serine, and isoleucine), tRNA concentrations. Finally, we review, analyze, and expand on the impact of codon usage on protein yield, secondary structures of mRNA, translation initiation and termination, and amino acid composition of proteins, as well as cotranslational protein folding. The comprehensive analysis of codon choice provides crucial insights into heterologous gene expression in the chloroplast of C. reinhardtii, which may also be applicable to other chloroplast-containing organisms and bacteria.
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Affiliation(s)
- Maxime Fages‐Lartaud
- Department of BiotechnologyNorwegian University of Science and TechnologyTrondheimN‐7491Norway
| | - Kristoffer Hundvin
- Department of BiotechnologyNorwegian University of Science and TechnologyTrondheimN‐7491Norway
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11
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Ye S, Lehmann J. Genetic code degeneracy is established by the decoding center of the ribosome. Nucleic Acids Res 2022; 50:4113-4126. [PMID: 35325219 PMCID: PMC9023292 DOI: 10.1093/nar/gkac171] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 02/10/2022] [Accepted: 03/23/2022] [Indexed: 11/21/2022] Open
Abstract
The degeneracy of the genetic code confers a wide array of properties to coding sequences. Yet, its origin is still unclear. A structural analysis has shown that the stability of the Watson–Crick base pair at the second position of the anticodon–codon interaction is a critical parameter controlling the extent of non-specific pairings accepted at the third position by the ribosome, a flexibility at the root of degeneracy. Based on recent cryo-EM analyses, the present work shows that residue A1493 of the decoding center provides a significant contribution to the stability of this base pair, revealing that the ribosome is directly involved in the establishment of degeneracy. Building on existing evolutionary models, we show the evidence that the early appearance of A1493 and A1492 established the basis of degeneracy when an elementary kinetic scheme of translation was prevailing. Logical considerations on the expansion of this kinetic scheme indicate that the acquisition of the peptidyl transferase center was the next major evolutionary step, while the induced-fit mechanism, that enables a sharp selection of the tRNAs, necessarily arose later when G530 was acquired by the decoding center.
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Affiliation(s)
- Shixin Ye
- INSERM U1195 unit, University of Paris-Saclay, 94276 Le Kremlin Bicêtre, France
| | - Jean Lehmann
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University of Paris-Saclay, 91198 Gif-sur-Yvette, France
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12
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“Superwobbling” and tRNA-34 Wobble and tRNA-37 Anticodon Loop Modifications in Evolution and Devolution of the Genetic Code. Life (Basel) 2022; 12:life12020252. [PMID: 35207539 PMCID: PMC8879553 DOI: 10.3390/life12020252] [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: 01/19/2022] [Revised: 01/25/2022] [Accepted: 02/01/2022] [Indexed: 11/17/2022] Open
Abstract
The genetic code evolved around the reading of the tRNA anticodon on the primitive ribosome, and tRNA-34 wobble and tRNA-37 modifications coevolved with the code. We posit that EF-Tu, the closing mechanism of the 30S ribosomal subunit, methylation of wobble U34 at the 5-carbon and suppression of wobbling at the tRNA-36 position were partly redundant and overlapping functions that coevolved to establish the code. The genetic code devolved in evolution of mitochondria to reduce the size of the tRNAome (all of the tRNAs of an organism or organelle). “Superwobbling” or four-way wobbling describes a major mechanism for shrinking the mitochondrial tRNAome. In superwobbling, unmodified wobble tRNA-U34 can recognize all four codon wobble bases (A, G, C and U), allowing a single unmodified tRNA-U34 to read a 4-codon box. During code evolution, to suppress superwobbling in 2-codon sectors, U34 modification by methylation at the 5-carbon position appears essential. As expected, at the base of code evolution, tRNA-37 modifications mostly related to the identity of the adjacent tRNA-36 base. TRNA-37 modifications help maintain the translation frame during elongation.
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Dalla Costa TP, Silva MC, de Santana Lopes A, Gomes Pacheco T, de Oliveira JD, de Baura VA, Balsanelli E, Maltempi de Souza E, de Oliveira Pedrosa F, Rogalski M. The plastome of Melocactus glaucescens Buining & Brederoo reveals unique evolutionary features and loss of essential tRNA genes. PLANTA 2022; 255:57. [PMID: 35113261 DOI: 10.1007/s00425-022-03841-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
The plastome of Melocactus glaucescens shows unique rearrangements, IR expansion, and unprecedented gene losses in Cactaceae. Our data indicate tRNA import from the cytosol to the plastids in this species. Cactaceae represents one of the richest families in keystone species of arid and semiarid biomes. This family shows various specific features comprehending morphology, anatomy, and metabolism, which allow them to grow under unfavorable environmental conditions. The subfamily Cactoideae contains the most divergence of species, which are highly variable in growth habit and morphology. This subfamily includes the endangered species Melocactus glaucescens (tribe Cereeae), which is a cactus endemic to the biome Caatinga in Brazil. Aiming to analyze the plastid evolution and develop molecular markers, we sequenced and analyzed in detail the plastome of M. glaucescens. Our analyses revealed that the M. glaucescens plastome is the most divergent among the species of the family Cactaceae sequenced so far. We characterized here unique rearrangements, expanded IRs containing an unusual set of genes, and several gene losses. Some genes related to the ndh complex were lost during the plastome evolution, while others have lost their functionality. Additionally, the loss of three tRNA genes (trnA-UGC, trnV-UAC, and trnV-GAC) suggests tRNA import from the cytosol to the plastids in M. glaucescens. Moreover, we identified high gene divergence, several putative positive signatures, and possible unique RNA-editing sites. Furthermore, we mapped 169 SSRs in the plastome of M. glaucescens, which are helpful to access the genetic diversity of natural populations and conservation strategies. Finally, our data provide new insights into the evolution of plastids in Cactaceae, which is an outstanding lineage adapted to extreme environmental conditions and a notorious example of the atypical evolution of plastomes.
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Affiliation(s)
- Tanara P Dalla Costa
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Maria C Silva
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Amanda de Santana Lopes
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Túlio Gomes Pacheco
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - José D de Oliveira
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Valter A de Baura
- Núcleo de Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Eduardo Balsanelli
- Núcleo de Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Emanuel Maltempi de Souza
- Núcleo de Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Fábio de Oliveira Pedrosa
- Núcleo de Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Marcelo Rogalski
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
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Overview of tRNA Modifications in Chloroplasts. Microorganisms 2022; 10:microorganisms10020226. [PMID: 35208681 PMCID: PMC8877259 DOI: 10.3390/microorganisms10020226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 01/16/2022] [Accepted: 01/18/2022] [Indexed: 11/29/2022] Open
Abstract
The chloroplast is a promising platform for biotechnological innovation due to its compact translation machinery. Nucleotide modifications within a minimal set of tRNAs modulate codon–anticodon interactions that are crucial for translation efficiency. However, a comprehensive assessment of these modifications does not presently exist in chloroplasts. Here, we synthesize all available information concerning tRNA modifications in the chloroplast and assign translation efficiency for each modified anticodon–codon pair. In addition, we perform a bioinformatics analysis that links enzymes to tRNA modifications and aminoacylation in the chloroplast of Chlamydomonas reinhardtii. This work provides the first comprehensive analysis of codon and anticodon interactions of chloroplasts and its implication for translation efficiency.
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Abdullah, Mehmood F, Heidari P, Rahim A, Ahmed I, Poczai P. Pseudogenization of the chloroplast threonine (trnT-GGU) gene in the sunflower family (Asteraceae). Sci Rep 2021; 11:21122. [PMID: 34702873 PMCID: PMC8548347 DOI: 10.1038/s41598-021-00510-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 10/05/2021] [Indexed: 01/22/2023] Open
Abstract
The chloroplast genome evolves through the course of evolution. Various types of mutational events are found within the chloroplast genome, including insertions-deletions (InDels), substitutions, inversions, gene rearrangement, and pseudogenization of genes. The pseudogenization of the chloroplast threonine (trnT-GGU) gene was previously reported in Cryptomeria japonica (Cupressaceae), Pelargonium × hortorum (Geraniaceae), and Anaphalis sinica and Leontopodium leiolepis of the tribe Gnaphalieae (Asteroideae, Asteraceae). Here, we performed a broad analysis of the trnT-GGU gene among the species of 13 subfamilies of Asteraceae and found this gene as a pseudogene in core Asteraceae (Gymnarrhenoideae, Cichorioideae, Corymbioideae, and Asteroideae), which was linked to an insertion event within the 5' acceptor stem and is not associated with ecological factors such as habit, habitat, and geographical distribution of the species. The pseudogenization of trnT-GGU was not predicted in codon usage, indicating that the superwobbling phenomenon occurs in core Asteraceae in which a single transfer RNA (trnT-UGU) decodes all four codons of threonine. To the best of our knowledge, this is the first evidence of a complete clade of a plant species using the superwobbling phenomenon for translation.
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Affiliation(s)
- Abdullah
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
| | - Furrukh Mehmood
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan
| | - Parviz Heidari
- Faculty of Agriculture, Shahrood University of Technology, 3619995161, Shahrood, Iran
| | - Abdur Rahim
- Government Degree College Nowshera, Abdul Wali Khan University, Mardan, KPK, Pakistan
| | - Ibrar Ahmed
- Alpha Genomics Private Limited, Islamabad, 45710, Pakistan
| | - Peter Poczai
- Finnish Museum of Natural History, University of Helsinki, P.O. Box 7, 00014, Helsinki, Finland.
- Faculty of Biological and Environmental Sciences, University of Helsinki, P.O. Box 65, 00065, Helsinki, Finland.
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16
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Abstract
Minimally evolved codes are constructed here; these have randomly chosen standard genetic code (SGC) triplets, completed with completely random triplet assignments. Such "genetic codes" have not evolved, but retain SGC qualities. Retained qualities are basic, part of the underpinning of coding. For example, the sensitivity of coding to arbitrary assignments, which must be < ∼10%, is intrinsic. Such sensitivity comes from the elementary combinatorial properties of coding and constrains any SGC evolution hypothesis. Similarly, assignment of last-evolved functions is difficult because of late kinetic phenomena, likely common across codes. Census of minimally evolved code assignments shows that shape and size of wobble domains controls the code's fit into a coding table, strongly shifting accuracy of codon assignments. Access to the SGC therefore requires a plausible pathway to limited randomness, avoiding difficult completion while fitting a highly ordered, degenerate code into a preset three-dimensional space. Three-dimensional late Crick wobble in a genetic code assembled by lateral transfer between early partial codes satisfies these varied, simultaneous requirements. By allowing parallel evolution of SGC domains, this origin can yield shortened evolution to SGC-level order and allow the code to arise in smaller populations. It effectively yields full codes. Less obviously, it unifies previously studied chemical, biochemical, and wobble order in amino acid assignment, including a stereochemical minority of triplet-amino acid associations. Finally, fusion of intermediates into the final SGC is credible, mirroring broadly accepted later cellular evolution.
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Manavski N, Vicente A, Chi W, Meurer J. The Chloroplast Epitranscriptome: Factors, Sites, Regulation, and Detection Methods. Genes (Basel) 2021; 12:genes12081121. [PMID: 34440296 PMCID: PMC8394491 DOI: 10.3390/genes12081121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/20/2021] [Accepted: 07/22/2021] [Indexed: 12/24/2022] Open
Abstract
Modifications in nucleic acids are present in all three domains of life. More than 170 distinct chemical modifications have been reported in cellular RNAs to date. Collectively termed as epitranscriptome, these RNA modifications are often dynamic and involve distinct regulatory proteins that install, remove, and interpret these marks in a site-specific manner. Covalent nucleotide modifications-such as methylations at diverse positions in the bases, polyuridylation, and pseudouridylation and many others impact various events in the lifecycle of an RNA such as folding, localization, processing, stability, ribosome assembly, and translational processes and are thus crucial regulators of the RNA metabolism. In plants, the nuclear/cytoplasmic epitranscriptome plays important roles in a wide range of biological processes, such as organ development, viral infection, and physiological means. Notably, recent transcriptome-wide analyses have also revealed novel dynamic modifications not only in plant nuclear/cytoplasmic RNAs related to photosynthesis but especially in chloroplast mRNAs, suggesting important and hitherto undefined regulatory steps in plastid functions and gene expression. Here we report on the latest findings of known plastid RNA modifications and highlight their relevance for the post-transcriptional regulation of chloroplast gene expression and their role in controlling plant development, stress reactions, and acclimation processes.
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Affiliation(s)
- Nikolay Manavski
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-University Munich, Großhaderner Street 2-4, 82152 Planegg-Martinsried, Germany; (N.M.); (A.V.)
| | - Alexandre Vicente
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-University Munich, Großhaderner Street 2-4, 82152 Planegg-Martinsried, Germany; (N.M.); (A.V.)
| | - Wei Chi
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China;
| | - Jörg Meurer
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-University Munich, Großhaderner Street 2-4, 82152 Planegg-Martinsried, Germany; (N.M.); (A.V.)
- Correspondence: ; Tel.: +49-89-218074556
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18
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Abstract
Plastids (chloroplasts) are the defining organelles of plants and eukaryotic algae. In addition to performing photosynthesis, plastids harbor numerous other metabolic pathways and therefore are often referred to as the biosynthetic center of the plant cell. The chloroplasts of seed plants possess dozens of copies of a circular genome of ∼150 kb that contains a conserved set of 120 to 130 genes. The engineering of this genome by genetic transformation is technically challenging and currently only possible in a small number of species. In this article, we describe the methods involved in generating stable chloroplast-transformed (transplastomic) plants in the model species Arabidopsis (Arabidopsis thaliana). The protocols presented here can be applied to (1) target genes in the Arabidopsis chloroplast genome by reverse genetics and (2) express reporter genes or other foreign genes of interest in plastids of Arabidopsis plants. © 2021 The Authors. Basic Protocol 1: Generation of root-derived microcallus material for biolistic transformation Basic Protocol 2: Chloroplast transformation by biolistic bombardment of root-derived microcalli Basic Protocol 3: Regeneration of transplastomic lines and seed production.
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Affiliation(s)
- Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Xenia Kroop
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
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19
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Guo X, Zhang G, Fan L, Liu C, Ji Y. Highly degenerate plastomes in two hemiparasitic dwarf mistletoes: Arceuthobium chinense and A. pini (Viscaceae). PLANTA 2021; 253:125. [PMID: 34028602 DOI: 10.1007/s00425-021-03643-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 05/19/2021] [Indexed: 06/12/2023]
Abstract
The leafless and endophytic habitat may significantly relax the selection pressure on photosynthesis, and plastid transcription and translation, causing the loss/pseudogenization of several essential plastid-encoding genes in dwarf mistletoes. Dwarf mistletoes (Arceuthobium spp., Viscaceae) are the most destructive plant parasites to numerous conifer species worldwide. In this study, the plastid genomes (plastomes) of Arceuthobium chinense Lecomte and A. pini Hawksworth and Wiens were sequenced and characterized. Although dwarf mistletoes are hemiparasites capable of photosynthesis, their plastomes were highly degenerated, as indicated by the smallest plastome size, the lowest GC content, and relatively very few intact genes among the Santalales hemiparasites. Unexpectedly, several essential housekeeping genes (rpoA, rpoB, rpoC1, and rpoC2) and some core photosynthetic genes (psbZ and petL), as well as the rpl33 gene, that is indispensable for plants under stress conditions, were deleted or pseudogenized in the Arceuthobium plastomes. Our data suggest that the leafless and endophytic habit, which heavily relies on the coniferous hosts for nutrients and carbon requirement, may largely relax the selection pressure on photosynthesis, as well as plastid transcription and translation, thus resulting in the loss/pseudogenization of such essential plastid-encoding genes in dwarf mistletoes. Therefore, the higher level of plastome degradation in Arceuthobium species than other Santalales hemiparasites is likely correlated with the evolution of leafless and endophytic habit. A higher degree of plastome degradation in Arceuthobium. These findings provide new insights into the plastome degeneration associated with parasitism in Santalales and deepen our understanding of the biology of dwarf mistletoes.
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Affiliation(s)
- Xiaorong Guo
- Institute of Ecology and Geobotany, Yunnan University, Kunming, Yunnan, China
- School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, China
| | - Guangfei Zhang
- Institute of Ecology and Geobotany, Yunnan University, Kunming, Yunnan, China
- School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, China
| | - Linyuan Fan
- Yunnan General Administration of Forestry Seeds and Seedlings, Kunming, Yunnan, China
| | - Changkun Liu
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Yunheng Ji
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China.
- Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Population, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China.
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20
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Caroca R, Howell KA, Malinova I, Burgos A, Tiller N, Pellizzer T, Annunziata MG, Hasse C, Ruf S, Karcher D, Bock R. Knockdown of the plastid-encoded acetyl-CoA carboxylase gene uncovers functions in metabolism and development. PLANT PHYSIOLOGY 2021; 185:1091-1110. [PMID: 33793919 PMCID: PMC8133629 DOI: 10.1093/plphys/kiaa106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 12/11/2020] [Indexed: 06/12/2023]
Abstract
De novo fatty acid biosynthesis in plants relies on a prokaryotic-type acetyl-CoA carboxylase (ACCase) that resides in the plastid compartment. The enzyme is composed of four subunits, one of which is encoded in the plastid genome, whereas the other three subunits are encoded by nuclear genes. The plastid gene (accD) encodes the β-carboxyltransferase subunit of ACCase and is essential for cell viability. To facilitate the functional analysis of accD, we pursued a transplastomic knockdown strategy in tobacco (Nicotiana tabacum). By introducing point mutations into the translational start codon of accD, we obtained stable transplastomic lines with altered ACCase activity. Replacement of the standard initiator codon AUG with UUG strongly reduced AccD expression, whereas replacement with GUG had no detectable effects. AccD knockdown mutants displayed reduced ACCase activity, which resulted in changes in the levels of many but not all species of cellular lipids. Limiting fatty acid availability caused a wide range of macroscopic, microscopic, and biochemical phenotypes, including impaired chloroplast division, reduced seed set, and altered storage metabolism. Finally, while the mutants displayed reduced growth under photoautotrophic conditions, they showed exaggerated growth under heterotrophic conditions, thus uncovering an unexpected antagonistic role of AccD activity in autotrophic and heterotrophic growth.
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Affiliation(s)
- Rodrigo Caroca
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Katharine A Howell
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Irina Malinova
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Asdrúbal Burgos
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Nadine Tiller
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Tommaso Pellizzer
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | | | - Claudia Hasse
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Daniel Karcher
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
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21
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Abstract
Wobble coding is inevitable during evolution of the Standard Genetic Code (SGC). It ultimately splits half of NN U/C/A/G coding boxes with different assignments. Further, it contributes to pervasive SGC order by reinforcing close spacing for identical SGC assignments. But wobble cannot appear too soon, or it will inhibit encoding and more decisively, obstruct evolution of full coding tables. However, these prior results assumed Crick wobble, NN U/C and NN A/G, read by a single adaptor RNA. Superwobble translates NN U/C/A/G codons, using one adaptor RNA with an unmodified 5' anticodon U (appropriate to earliest coding) in modern mitochondria, plastids, and mycoplasma. Assuming the SGC was selected when evolving codes most resembled it, characteristics of the critical selection events can be calculated. For example, continuous superwobble infrequently evolves SGC-like coding tables. So, continuous superwobble is a very improbable origin hypothesis. In contrast, late-arising superwobble shares late Crick wobble's frequent resemblance to SGC order. Thus late superwobble is possible, but yields SGC-like assignments less frequently than late Crick wobble. Ancient coding ambiguity, most simply, arose from Crick wobble alone. This is consistent with SGC assignments to NAN codons.
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Affiliation(s)
- Michael Yarus
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309-0347, USA.
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22
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Pacheco TG, Lopes ADS, Welter JF, Yotoko KSC, Otoni WC, Vieira LDN, Guerra MP, Nodari RO, Balsanelli E, Pedrosa FDO, de Souza EM, Rogalski M. Plastome sequences of the subgenus Passiflora reveal highly divergent genes and specific evolutionary features. PLANT MOLECULAR BIOLOGY 2020; 104:21-37. [PMID: 32533420 DOI: 10.1007/s11103-020-01020-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 06/07/2020] [Indexed: 06/11/2023]
Affiliation(s)
- Túlio Gomes Pacheco
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Amanda de Santana Lopes
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Juliana Fátima Welter
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Karla Suemy Clemente Yotoko
- Laboratório de Bioinformática e Evolução, Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Wagner Campos Otoni
- Laboratório de Cultura de Tecidos Vegetais, Departamento de Biologia Vegetal, BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Leila do Nascimento Vieira
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Miguel Pedro Guerra
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Rubens Onofre Nodari
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Eduardo Balsanelli
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Fábio de Oliveira Pedrosa
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Emanuel Maltempi de Souza
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Marcelo Rogalski
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
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23
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Ou X, Peng W, Yang Z, Cao J, Wang M, Peppelenbosch MP, Pan Q, Cheng A. Evolutionarily missing and conserved tRNA genes in human and avian. INFECTION GENETICS AND EVOLUTION 2020; 85:104460. [PMID: 32679345 DOI: 10.1016/j.meegid.2020.104460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 07/01/2020] [Accepted: 07/09/2020] [Indexed: 11/29/2022]
Abstract
Viral infection heavily relies on host transfer RNA (tRNA) for viral RNA decoding. Counterintuitively, not all tRNA species based on anticodon are matched to all 64-triplet codons during evolution. Life solves this problem by cognate tRNA species via wobbling decoding. We found that 14 out of 64 tRNA genes in humans and the main avian species (chicken and duck) were parallelly missing, including 8 tRNA-A34NN and 6 tRNA-G34NN species. By analyzing the conservation of key motifs in tRNA genes, we found that box A and B served as intragenic tRNA promoters were evolutionally conserved among human, chicken, and duck. Thus, decoding viral RNA by similar wobbling strategies and tRNA transcripts may be parallelly used by human, chicken, and duck. We envisioned that many basic mechanisms regarding viral RNA decoding were possibly conserved in these hosts and may consequently promote cross-species infection. Transfer RNAs (tRNAs) are essentially required for gene decoding. Despite the universal nature of genetic codon, not all tRNA genes are common to all organisms. Here, we would like to discuss fundamental problems and possible effects arising from the evolutionarily missing and conserved tRNA genes in human, chicken, and duck (Alkatib et al., 2012; Ou et al., 2019; Rogalski et al., 2008). Among these three organisms, viruses especially the avian influenza virus can crossly infect (Pepin et al., 2010). For multi-host viruses, similar viral RNA decoding strategies may be parallelly used by different hosts. Because viral cross-species infection heavily relies on host tRNAs of different species for viral RNA decoding (Ou et al., 2020; van Weringh et al., 2011). We envisioned that many basic mechanisms regarding viral RNA decoding were possibly conserved in these three hosts and may consequently promote cross-species infection.
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Affiliation(s)
- Xumin Ou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, China; Postgraduate School Molecular Medicine, Erasmus MC-University Medical Center, 3015 CN Rotterdam, the Netherlands; Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, China.
| | - Wenjing Peng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, China
| | - Zhishuang Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, China; Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, China
| | - Jingyu Cao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, China; Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, China
| | - Maikel P Peppelenbosch
- Postgraduate School Molecular Medicine, Erasmus MC-University Medical Center, 3015 CN Rotterdam, the Netherlands
| | - Qiuwei Pan
- Postgraduate School Molecular Medicine, Erasmus MC-University Medical Center, 3015 CN Rotterdam, the Netherlands
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, China; Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, China.
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Gomes Pacheco T, Morais da Silva G, de Santana Lopes A, de Oliveira JD, Rogalski JM, Balsanelli E, Maltempi de Souza E, de Oliveira Pedrosa F, Rogalski M. Phylogenetic and evolutionary features of the plastome of Tropaeolum pentaphyllum Lam. (Tropaeolaceae). PLANTA 2020; 252:17. [PMID: 32666132 DOI: 10.1007/s00425-020-03427-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/08/2020] [Indexed: 06/11/2023]
Abstract
Complete plastome sequence of Tropaeolum pentaphyllum revealed molecular markers, hotspots of nucleotide polymorphism, RNA editing sites and phylogenetic aspects Tropaeolaceae Juss. ex DC. comprises approximately 95 species across North and South Americas. Tropaeolum pentaphyllum Lam. is an unconventional and endangered species with occurrence in some countries of South America. Although this species presents nutritional, medicinal and ornamental uses, genetic studies involving natural populations or promising genotypes are practically non-existent. Here, we report the nucleotide sequence of T. pentaphyllum plastome. It represents the first complete plastome sequence of the family Tropaeolaceae to be fully sequenced and analyzed in detail. The sequencing data revealed that the T. pentaphyllum plastome is highly similar to the plastomes of other Brassicales. Notwithstanding, our analyses detected some specific features concerning events of IR expansion and structural changes in some genes such as matK, rpoA, and rpoC2. We also detected 251 SSR loci, nine hotspots of nucleotide polymorphism, and two specific RNA editing sites in the plastome of T. pentaphyllum. Moreover, plastid phylogenomic inference indicated a closed relationship between the families Tropaeolaceae and Akaniaceae, which formed a sister group to Moringaceae-Caricaceae. Finally, our data bring new molecular markers and evolutionary features to be applied in the natural population, germplasm collection, and genotype selection aiming conservation, genetic diversity evaluation, and exploitation of this endangered species.
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Affiliation(s)
- Túlio Gomes Pacheco
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Gleyson Morais da Silva
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Amanda de Santana Lopes
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - José Daniel de Oliveira
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Juliana Marcia Rogalski
- Núcleo de Ciências Biológicas e Ambientais, Instituto Federal do Rio Grande do Sul, Distrito Engenheiro Luiz Englert, Sertão, RS, Brazil
| | - Eduardo Balsanelli
- Núcleo de Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Emanuel Maltempi de Souza
- Núcleo de Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Fábio de Oliveira Pedrosa
- Núcleo de Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Marcelo Rogalski
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
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Liu H, Ren D, Jiang L, Li X, Yao Y, Mi L, Chen W, Mo A, Jiang N, Yang J, Chen P, Ma H, Luo X, Lu P. A Natural Variation in PLEIOTROPIC DEVELOPMENTAL DEFECTS Uncovers a Crucial Role for Chloroplast tRNA Modification in Translation and Plant Development. THE PLANT CELL 2020; 32:2345-2366. [PMID: 32327539 PMCID: PMC7346568 DOI: 10.1105/tpc.19.00660] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 03/30/2020] [Accepted: 04/15/2020] [Indexed: 05/28/2023]
Abstract
The modification of tRNA is important for accurate, efficient protein translation. A number of tRNA-modifying enzymes were found to influence various developmental processes in distinct organisms. However, few genetic or molecular studies have focused on genes encoding tRNA-modifying enzymes in green plant organelles. Here, we discovered that PDD OL , a natural variation allele of PLEIOTROPIC DEVELOPMENTAL DEFECTS (PDD), leads to pleiotropic developmental defects in a near-isogenic line (NIL) generated by introgressing the wild rice Oryza longistaminata into the rice (Oryza sativa) cv 187R. Map-based cloning revealed that PDD encodes an evolutionarily conserved tRNA-modifying GTPase belonging to the tRNA modification E family. The function of PDD was further confirmed by genetic complementation experiments and mutant analysis. PDD mRNA is primarily expressed in leaves, and PDD is localized to chloroplasts. Biochemical analyses indicated that PDD187R forms homodimers and has strong GTPase activity, whereas PDDOL fails to form homodimers and has weak GTPase activity. Liquid chromatography-coupled tandem quadrupole mass spectrometry revealed that PDD is associated with the 5-methylaminomethyl-2-thiouridine modification of chloroplast tRNA. Furthermore, compared to 187R, NIL-PDD OL has severely reduced levels of proteins involved in photosynthesis and ribosome biogenesis but increased levels of plastid-encoded RNA polymerase subunits. Finally, we demonstrate that the defect due to PDD OL alters chloroplast gene expression, thereby affecting communication between the chloroplast and the nucleus.
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Affiliation(s)
- Hui Liu
- School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Ding Ren
- School of Life Sciences, Fudan University, Shanghai 200433, China
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Ling Jiang
- School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Xiaojing Li
- School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Yuan Yao
- School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Limin Mi
- School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Wanli Chen
- School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Aowei Mo
- School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Ning Jiang
- School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Jinshui Yang
- School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Peng Chen
- Biomass and Bioenergy Research Centre, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hong Ma
- Department of Biology, Eberly College of Science, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Xiaojin Luo
- School of Life Sciences, Fudan University, Shanghai 200433, China
- MOE Engineering Research Center of Gene Technology, Fudan University, Shanghai 200433, China
| | - Pingli Lu
- School of Life Sciences, Fudan University, Shanghai 200433, China
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
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Sudianto E, Wu CS, Chaw SM. The Origin and Evolution of Plastid Genome Downsizing in Southern Hemispheric Cypresses (Cupressaceae). FRONTIERS IN PLANT SCIENCE 2020; 11:901. [PMID: 32655606 PMCID: PMC7324783 DOI: 10.3389/fpls.2020.00901] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/02/2020] [Indexed: 05/08/2023]
Abstract
Plastome downsizing is rare in photosynthetic seed plants. However, a large-scale study of five cupressophyte families (conifers II) indicated that the plastomes of some Cupressaceous genera are notably reduced and compact. Here, we enriched taxon sampling in Cupressaceae by adding plastomes of ten previously unreported genera to determine the origin, evolution, and consequences of plastome reduction in this family. We discovered that plastome downsizing is specific to Callitroideae (a Southern Hemispheric subfamily). Their plastomes are the smallest, encode the fewest plastid genes, and contain the fewest GC-end codons among Cupressaceae. We show that repeated tRNA losses and shrinkage of intergenic spacers together contributed to the plastome downsizing in Callitroideae. Moreover, our absolute nucleotide substitution rate analyses suggest relaxed functional constraints in translation-related plastid genes (clpP, infA, rpl, and rps), but not in photosynthesis- or transcription-related ones, of Callitris (the most diverse genus in Callitroideae). We hypothesize that the small and low-GC plastomes of Callitroideae emerged ca. 112-75 million years ago as an adaptation to increased competition with angiosperms on the Gondwana supercontinent. Our findings highlight Callitroideae as another case of plastome downsizing in photosynthetic seed plant lineages.
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Agrawal S, Karcher D, Ruf S, Bock R. The Functions of Chloroplast Glutamyl-tRNA in Translation and Tetrapyrrole Biosynthesis. PLANT PHYSIOLOGY 2020; 183:263-276. [PMID: 32071153 PMCID: PMC7210637 DOI: 10.1104/pp.20.00009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 01/31/2020] [Indexed: 06/02/2023]
Abstract
The chloroplast glutamyl-tRNA (tRNAGlu) is unique in that it has two entirely different functions. In addition to acting in translation, it serves as the substrate of glutamyl-tRNA reductase (GluTR), the enzyme catalyzing the committed step in the tetrapyrrole biosynthetic pathway. How the tRNAGlu pool is distributed between the two pathways and whether tRNAGlu allocation limits tetrapyrrole biosynthesis and/or protein biosynthesis remains poorly understood. We generated a series of transplastomic tobacco (Nicotiana tabacum) plants to alter tRNAGlu expression levels and introduced a point mutation into the plastid trnE gene, which has been reported to uncouple protein biosynthesis from tetrapyrrole biosynthesis in chloroplasts of the protist Euglena gracilis We show that, rather than comparable uncoupling of the two pathways, the trnE mutation is lethal in tobacco because it inhibits tRNA processing, thus preventing translation of Glu codons. Ectopic expression of the mutated trnE gene uncovered an unexpected inhibition of glutamyl-tRNA reductase by immature tRNAGlu We further demonstrate that whereas overexpression of tRNAGlu does not affect tetrapyrrole biosynthesis, reduction of GluTR activity through inhibition by tRNAGlu precursors causes tetrapyrrole synthesis to become limiting in early plant development when active photosystem biogenesis provokes a high demand for de novo chlorophyll biosynthesis. Taken together, our findings provide insight into the roles of tRNAGlu at the intersection of protein biosynthesis and tetrapyrrole biosynthesis.
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Affiliation(s)
- Shreya Agrawal
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Daniel Karcher
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
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Gobet C, Weger BD, Marquis J, Martin E, Neelagandan N, Gachon F, Naef F. Robust landscapes of ribosome dwell times and aminoacyl-tRNAs in response to nutrient stress in liver. Proc Natl Acad Sci U S A 2020; 117:9630-9641. [PMID: 32295881 PMCID: PMC7196831 DOI: 10.1073/pnas.1918145117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Translation depends on messenger RNA (mRNA)-specific initiation, elongation, and termination rates. While translation elongation is well studied in bacteria and yeast, less is known in higher eukaryotes. Here we combined ribosome and transfer RNA (tRNA) profiling to investigate the relations between translation elongation rates, (aminoacyl-) tRNA levels, and codon usage in mammals. We modeled codon-specific ribosome dwell times from ribosome profiling, considering codon pair interactions between ribosome sites. In mouse liver, the model revealed site- and codon-specific dwell times that differed from those in yeast, as well as pairs of adjacent codons in the P and A site that markedly slow down or speed up elongation. While translation efficiencies vary across diurnal time and feeding regimen, codon dwell times were highly stable and conserved in human. Measured tRNA levels correlated with codon usage and several tRNAs showed reduced aminoacylation, which was conserved in fasted mice. Finally, we uncovered that the longest codon dwell times could be explained by aminoacylation levels or high codon usage relative to tRNA abundance.
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Affiliation(s)
- Cédric Gobet
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
- Nestlé Research, CH-1015 Lausanne, Switzerland
| | - Benjamin Dieter Weger
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
- Nestlé Research, CH-1015 Lausanne, Switzerland
| | | | - Eva Martin
- Nestlé Research, CH-1015 Lausanne, Switzerland
| | - Nagammal Neelagandan
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | | | - Felix Naef
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland;
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29
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Severe Plastid Genome Size Reduction in a Mycoheterotrophic Orchid, Danxiaorchis singchiana, Reveals Heavy Gene Loss and Gene Relocations. PLANTS 2020; 9:plants9040521. [PMID: 32316476 PMCID: PMC7238169 DOI: 10.3390/plants9040521] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/09/2020] [Accepted: 04/11/2020] [Indexed: 11/17/2022]
Abstract
Danxiaorchis singchiana (Orchidaceae) is a leafless mycoheterotrophic orchid in the subfamily Epidendroideae. We sequenced the complete plastome of D. singchiana. The plastome has a reduced size of 87,931 bp, which includes a pair of inverted repeat (IR) regions of 13,762 bp each that are separated by a large single copy (LSC) region of 42,575 bp and a small single copy (SSC) region of 17,831 bp. When compared to its sister taxa, Cremastra appendiculata and Corallorhiza striata var. involuta, D. singchiana showed an inverted gene block in the LSC and SSC regions. A total of 61 genes were predicted, including 21 tRNA, 4 rRNA, and 36 protein-coding genes. While most of the housekeeping genes were still intact and seem to be protein-coding, only four photosynthesis-related genes appeared presumably intact. The majority of the presumably intact protein-coding genes seem to have undergone purifying selection (dN/dS < 1), and only the psaC gene was positively selected (dN/dS > 1) when compared to that in Cr. appendiculata. Phylogenetic analysis of 26 complete plastome sequences from 24 species of the tribe Epidendreae had revealed that D. singchiana diverged after Cr. appendiculata and is sister to the genus Corallorhiza with strong bootstrap support (100%).
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Henriquez CL, Ahmed I, Carlsen MM, Zuluaga A, Croat TB, McKain MR. Molecular evolution of chloroplast genomes in Monsteroideae (Araceae). PLANTA 2020; 251:72. [PMID: 32112137 DOI: 10.1007/s00425-020-03365-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/14/2020] [Indexed: 05/02/2023]
Abstract
This study provides broad insight into the chloroplast genomes of the subfamily Monsteroideae. The identified polymorphic regions may be suitable for designing unique and robust molecular markers for phylogenetic inference. Monsteroideae is the third largest subfamily (comprises 369 species) and one of the early diverging lineages of the monocot plant family Araceae. The phylogeny of this important subfamily is not well resolved at the species level due to scarcity of genomic resources and suitable molecular markers. Here, we report annotated chloroplast genome sequences of four Monsteroideae species: Spathiphyllum patulinervum, Stenospermation multiovulatum, Monstera adansonii, and Rhaphidophora amplissima. The quadripartite chloroplast genomes (size range 163,335-164,751 bp) consist of a pair of inverted repeats (25,270-25,931 bp), separating a small single copy region (21,448-22,346 bp) from a large single copy region (89,714-91,841 bp). The genomes contain 114 unique genes, including four rRNA genes, 80 protein-coding genes, and 30 tRNA genes. Gene features, amino acid frequencies, codon usage, GC contents, oligonucleotide repeats, and inverted repeats dynamics exhibit similarities among the four genomes. Higher rate of synonymous substitutions was observed as compared to non-synonymous substitutions in 76 protein-coding genes. Positive selection was observed in seven protein-coding genes, including psbK, ndhK, ndhD, rbcL, accD, rps8, and ycf2. Our included species of Araceae showed the monophyly in Monsteroideae and other subfamilies. We report 30 suitable polymorphic regions. The polymorphic regions identified here might be suitable for designing unique and robust markers for inferring the phylogeny and phylogeography among closely related species within the genus Spathiphyllum and among distantly related species within the subfamily Monsteroideae. The chloroplast genomes presented here are a valuable contribution towards understanding the molecular evolutionary dynamics in the family Araceae.
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Affiliation(s)
- Claudia L Henriquez
- University of California, Department of Ecology and Evolutionary Biology, Los Angeles, USA.
| | - Ibrar Ahmed
- Alpha Genomics Private Limited, Islamabad, 45710, Pakistan
| | | | - Alejandro Zuluaga
- Departamento de Biología, Universidad del Valle, Calle 13, 100-00, Cali, Colombia
| | | | - Michael R McKain
- The University of Alabama, Department of Biological Sciences, Tuscaloosa, AL, USA
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31
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Repetti SI, Jackson CJ, Judd LM, Wick RR, Holt KE, Verbruggen H. The inflated mitochondrial genomes of siphonous green algae reflect processes driving expansion of noncoding DNA and proliferation of introns. PeerJ 2020; 8:e8273. [PMID: 31915577 PMCID: PMC6944098 DOI: 10.7717/peerj.8273] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 11/22/2019] [Indexed: 02/06/2023] Open
Abstract
Within the siphonous green algal order Bryopsidales, the size and gene arrangement of chloroplast genomes has been examined extensively, while mitochondrial genomes have been mostly overlooked. The recently published mitochondrial genome of Caulerpa lentillifera is large with expanded noncoding DNA, but it remains unclear if this is characteristic of the entire order. Our study aims to evaluate the evolutionary forces shaping organelle genome dynamics in the Bryopsidales based on the C. lentillifera and Ostreobium quekettii mitochondrial genomes. In this study, the mitochondrial genome of O. quekettii was characterised using a combination of long and short read sequencing, and bioinformatic tools for annotation and sequence analyses. We compared the mitochondrial and chloroplast genomes of O. quekettii and C. lentillifera to examine hypotheses related to genome evolution. The O. quekettii mitochondrial genome is the largest green algal mitochondrial genome sequenced (241,739 bp), considerably larger than its chloroplast genome. As with the mtDNA of C. lentillifera, most of this excess size is from the expansion of intergenic DNA and proliferation of introns. Inflated mitochondrial genomes in the Bryopsidales suggest effective population size, recombination and/or mutation rate, influenced by nuclear-encoded proteins, differ between the genomes of mitochondria and chloroplasts, reducing the strength of selection to influence evolution of their mitochondrial genomes.
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Affiliation(s)
- Sonja I Repetti
- School of BioSciences, University of Melbourne, Melbourne, VIC, Australia
| | | | - Louise M Judd
- Department of Infectious Diseases, Monash University, Melbourne, VIC, Australia
| | - Ryan R Wick
- Department of Infectious Diseases, Monash University, Melbourne, VIC, Australia
| | - Kathryn E Holt
- Department of Infectious Diseases, Monash University, Melbourne, VIC, Australia
| | - Heroen Verbruggen
- School of BioSciences, University of Melbourne, Melbourne, VIC, Australia
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de Santana Lopes A, Gomes Pacheco T, Nascimento da Silva O, Magalhães Cruz L, Balsanelli E, Maltempi de Souza E, de Oliveira Pedrosa F, Rogalski M. The plastomes of Astrocaryum aculeatum G. Mey. and A. murumuru Mart. show a flip-flop recombination between two short inverted repeats. PLANTA 2019; 250:1229-1246. [PMID: 31222493 DOI: 10.1007/s00425-019-03217-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 06/18/2019] [Indexed: 06/09/2023]
Abstract
The plastomes of Astrocaryum murumuru and A. aculeatum revealed a lineage-specific structural feature originated by flip-flop recombination, non-synonymous substitutions in conserved genes and several molecular markers. Astrocaryum murumuru Mart. and A. aculeatum G.Mey. are two palm species of Amazon forest that are economically important as source of food, oil and raw material for several applications. Genetic studies aiming to establish strategies for conservation and domestication of both species are still in the beginning given that the exploitation is mostly by extractive activity. The identification and characterization of molecular markers are essential to assess the genetic diversity of natural populations of both species. Therefore, we sequenced and characterized in detail the plastome of both species. We compared both species and identified 32 polymorphic SSR loci, 150 SNPs, 46 indels and eight hotspots of nucleotide diversity. Additionally, we reported a specific RNA editing site found in the ccsA gene, which is exclusive to A. murumuru. Moreover, the structural analysis in the plastomes of both species revealed a 4.6-kb inversion encompassing a set of genes involved in chlororespiration and plastid translation. This 4.6-kb inversion is a lineage-specific structural feature of the genus Astrocaryum originated by flip-flop recombination between two short inverted repeats. Furthermore, our phylogenetic analysis using whole plastomes of 39 Arecaceae species placed the Astrocaryum species sister to Acrocomia within the tribe Cocoseae. Finally, our data indicated substantial changes in the plastome structure and sequence of both species of the genus Astrocaryum, bringing new molecular markers, several structural and evolving features, which can be applied in several areas such as genetic, evolution, breeding, phylogeny and conservation strategies for both species.
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Affiliation(s)
- Amanda de Santana Lopes
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Túlio Gomes Pacheco
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Odyone Nascimento da Silva
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Leonardo Magalhães Cruz
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Eduardo Balsanelli
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Emanuel Maltempi de Souza
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Fábio de Oliveira Pedrosa
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Marcelo Rogalski
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
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Turmel M, Lopes Dos Santos A, Otis C, Sergerie R, Lemieux C. Tracing the Evolution of the Plastome and Mitogenome in the Chloropicophyceae Uncovered Convergent tRNA Gene Losses and a Variant Plastid Genetic Code. Genome Biol Evol 2019; 11:1275-1292. [PMID: 30937436 PMCID: PMC6486808 DOI: 10.1093/gbe/evz074] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2019] [Indexed: 01/06/2023] Open
Abstract
The tiny green algae belonging to the Chloropicophyceae play a key role in marine phytoplankton communities; this newly erected class of prasinophytes comprises two genera (Chloropicon and Chloroparvula) containing each several species. We sequenced the plastomes and mitogenomes of eight Chloropicon and five Chloroparvula species to better delineate the phylogenetic affinities of these taxa and to infer the suite of changes that their organelle genomes sustained during evolution. The relationships resolved in organelle-based phylogenomic trees were essentially congruent with previously reported rRNA trees, and similar evolutionary trends but distinct dynamics were identified for the plastome and mitogenome. Although the plastome sustained considerable changes in gene content and order at the time the two genera split, subsequently it remained stable and maintained a very small size. The mitogenome, however, was remodeled more gradually and showed more fluctuation in size, mainly as a result of expansions/contractions of intergenic regions. Remarkably, the plastome and mitogenome lost a common set of three tRNA genes, with the trnI(cau) and trnL(uaa) losses being accompanied with important variations in codon usage. Unexpectedly, despite the disappearance of trnI(cau) from the plastome in the Chloroparvula lineage, AUA codons (the codons recognized by this gene product) were detected in certain plastid genes. By comparing the sequences of plastid protein-coding genes from chloropicophycean and phylogenetically diverse chlorophyte algae with those of the corresponding predicted proteins, we discovered that the AUA codon was reassigned from isoleucine to methionine in Chloroparvula. This noncanonical genetic code has not previously been uncovered in plastids.
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Affiliation(s)
- Monique Turmel
- Département de biochimie, de microbiologie et de bio-informatique, Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec City, Québec, Canada
| | - Adriana Lopes Dos Santos
- Asian School of the Environment, Nanyang Technological University, Singapore.,CNRS, Sorbonne Université, UMR 7144 Station Biologique de Roscoff, Roscoff, France
| | - Christian Otis
- Département de biochimie, de microbiologie et de bio-informatique, Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec City, Québec, Canada
| | - Roxanne Sergerie
- Département de biochimie, de microbiologie et de bio-informatique, Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec City, Québec, Canada
| | - Claude Lemieux
- Département de biochimie, de microbiologie et de bio-informatique, Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec City, Québec, Canada
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Ou X, Cao J, Cheng A, Peppelenbosch MP, Pan Q. Errors in translational decoding: tRNA wobbling or misincorporation? PLoS Genet 2019; 15:e1008017. [PMID: 30921315 PMCID: PMC6438450 DOI: 10.1371/journal.pgen.1008017] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
As the central dogma of molecular biology, genetic information flows from DNA through transcription into RNA followed by translation of the message into protein by transfer RNAs (tRNAs). However, mRNA translation is not always perfect, and errors in the amino acid composition may occur. Mistranslation is generally well tolerated, but once it reaches superphysiological levels, it can give rise to a plethora of diseases. The key causes of mistranslation are errors in translational decoding of the codons in mRNA. Such errors mainly derive from tRNA misdecoding and misacylation, especially when certain codon-paired tRNA species are missing. Substantial progress has recently been made with respect to the mechanistic basis of erroneous mRNA decoding as well as the resulting consequences for physiology and pathology. Here, we aim to review this progress with emphasis on viral evolution and cancer development.
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Affiliation(s)
- Xumin Ou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands
| | - Jingyu Cao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- * E-mail: (AC); (QP)
| | - Maikel P. Peppelenbosch
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands
| | - Qiuwei Pan
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands
- * E-mail: (AC); (QP)
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35
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Smith DR. Evolution: A Plant Plastid Genome that Has Forsaken Guanine and Cytosine. Curr Biol 2019; 29:R99-R101. [PMID: 30721685 DOI: 10.1016/j.cub.2018.12.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The plastid genomes of the non-photosynthetic plants Balanophora reflexa and B. laxiflora are among the most GC-biased genomes observed to date. A new study shows that ∼80% of the plastid-derived proteome is represented by only six amino acids, and several genes are in excess of 95% AT.
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Affiliation(s)
- David Roy Smith
- Department of Biology, University of Western Ontario, London, ON, Canada.
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36
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Ševcíková T, Yurchenko T, Fawley KP, Amaral R, Strnad H, Santos LMA, Fawley MW, Eliáš M. Plastid Genomes and Proteins Illuminate the Evolution of Eustigmatophyte Algae and Their Bacterial Endosymbionts. Genome Biol Evol 2019; 11:362-379. [PMID: 30629162 PMCID: PMC6367104 DOI: 10.1093/gbe/evz004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/05/2019] [Indexed: 12/26/2022] Open
Abstract
Eustigmatophytes, a class of stramenopile algae (ochrophytes), include not only the extensively studied biotechnologically important genus Nannochloropsis but also a rapidly expanding diversity of lineages with much less well characterized biology. Recent discoveries have led to exciting additions to our knowledge about eustigmatophytes. Some proved to harbor bacterial endosymbionts representing a novel genus, Candidatus Phycorickettsia, and an operon of unclear function (ebo) obtained by horizontal gene transfer from the endosymbiont lineage was found in the plastid genomes of still other eustigmatophytes. To shed more light on the latter event, as well as to generally improve our understanding of the eustigmatophyte evolutionary history, we sequenced plastid genomes of seven phylogenetically diverse representatives (including new isolates representing undescribed taxa). A phylogenomic analysis of plastid genome-encoded proteins resolved the phylogenetic relationships among the main eustigmatophyte lineages and provided a framework for the interpretation of plastid gene gains and losses in the group. The ebo operon gain was inferred to have probably occurred within the order Eustigmatales, after the divergence of the two basalmost lineages (a newly discovered hitherto undescribed strain and the Pseudellipsoidion group). When looking for nuclear genes potentially compensating for plastid gene losses, we noticed a gene for a plastid-targeted acyl carrier protein that was apparently acquired by horizontal gene transfer from Phycorickettsia. The presence of this gene in all eustigmatophytes studied, including representatives of both principal clades (Eustigmatales and Goniochloridales), is a genetic footprint indicating that the eustigmatophyte-Phycorickettsia partnership started no later than in the last eustigmatophyte common ancestor.
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Affiliation(s)
- Tereza Ševcíková
- Department of Biology and Ecology Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Tatiana Yurchenko
- Faculty of Science, Institute of Environmental Technologies, University of Ostrava, Ostrava, Czech Republic
| | - Karen P Fawley
- Division of Sciences and Mathematics, University of the Ozarks, Clarksville, Arkansas
| | - Raquel Amaral
- Coimbra Collection of Algae (ACOI), Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | - Hynek Strnad
- Laboratory of Genomics and Bioinformatics, Institute of Molecular Genetics of the CAS, v.v.i., Prague, Czech Republic
| | - Lilia M A Santos
- Coimbra Collection of Algae (ACOI), Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | - Marvin W Fawley
- Division of Sciences and Mathematics, University of the Ozarks, Clarksville, Arkansas.,School of Mathematical and Natural Sciences, University of Arkansas at Monticello, Monticello, Arkansas
| | - Marek Eliáš
- Department of Biology and Ecology Faculty of Science, University of Ostrava, Ostrava, Czech Republic.,Faculty of Science, Institute of Environmental Technologies, University of Ostrava, Ostrava, Czech Republic
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Gomes Pacheco T, de Santana Lopes A, Monteiro Viana GD, Nascimento da Silva O, Morais da Silva G, do Nascimento Vieira L, Guerra MP, Nodari RO, Maltempi de Souza E, de Oliveira Pedrosa F, Otoni WC, Rogalski M. Genetic, evolutionary and phylogenetic aspects of the plastome of annatto (Bixa orellana L.), the Amazonian commercial species of natural dyes. PLANTA 2019; 249:563-582. [PMID: 30310983 DOI: 10.1007/s00425-018-3023-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 10/01/2018] [Indexed: 06/08/2023]
Abstract
The plastome of B. orellana reveals specific evolutionary features, unique RNA editing sites, molecular markers and the position of Bixaceae within Malvales. Annatto (Bixa orellana L.) is a native species of tropical Americas with center of origin in Brazilian Amazonia. Its seeds accumulate the apocarotenoids, bixin and norbixin, which are only found in high content in this species. The seeds of B. orellana are commercially valued by the food industry because its dyes replace synthetic ones from the market due to potential carcinogenic risks. The increasing consumption of B. orellana seeds for dye extraction makes necessary the increase of productivity, which is possible accessing the genetic basis and searching for elite genotypes. The identification and characterization of molecular markers are essential to analyse the genetic diversity of natural populations and to establish suitable strategies for conservation, domestication, germplasm characterization and genetic breeding. Therefore, we sequenced and characterized in detail the plastome of B. orellana. The plastome of B. orellana is a circular DNA molecule of 159,708 bp with a typical quadripartite structure and 112 unique genes. Additionally, a total of 312 SSR loci were identified in the plastome of B. orellana. Moreover, we predicted in 23 genes a total of 57 RNA-editing sites of which 11 are unique for B. orellana. Furthermore, our plastid phylogenomic analyses, using the plastome sequences available in the plastid database belonging to species of order Malvales, indicate a closed relationship between Bixaceae and Malvaceae, which formed a sister group to Thymelaeaceae. Finally, our study provided useful data to be employed in several genetic and biotechnological approaches in B. orellana and related species of the family Bixaceae.
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Affiliation(s)
- Túlio Gomes Pacheco
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Amanda de Santana Lopes
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Gélia Dinah Monteiro Viana
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Odyone Nascimento da Silva
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Gleyson Morais da Silva
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Leila do Nascimento Vieira
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Miguel Pedro Guerra
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Rubens Onofre Nodari
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Emanuel Maltempi de Souza
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Fábio de Oliveira Pedrosa
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Wagner Campos Otoni
- Laboratório de Cultura de Tecidos Vegetais, Departamento de Biologia Vegetal, BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Marcelo Rogalski
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
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38
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Su HJ, Barkman TJ, Hao W, Jones SS, Naumann J, Skippington E, Wafula EK, Hu JM, Palmer JD, dePamphilis CW. Novel genetic code and record-setting AT-richness in the highly reduced plastid genome of the holoparasitic plant Balanophora. Proc Natl Acad Sci U S A 2019; 116:934-943. [PMID: 30598433 PMCID: PMC6338844 DOI: 10.1073/pnas.1816822116] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Plastid genomes (plastomes) vary enormously in size and gene content among the many lineages of nonphotosynthetic plants, but key lineages remain unexplored. We therefore investigated plastome sequence and expression in the holoparasitic and morphologically bizarre Balanophoraceae. The two Balanophora plastomes examined are remarkable, exhibiting features rarely if ever seen before in plastomes or in any other genomes. At 15.5 kb in size and with only 19 genes, they are among the most reduced plastomes known. They have no tRNA genes for protein synthesis, a trait found in only three other plastid lineages, and thus Balanophora plastids must import all tRNAs needed for translation. Balanophora plastomes are exceptionally compact, with numerous overlapping genes, highly reduced spacers, loss of all cis-spliced introns, and shrunken protein genes. With A+T contents of 87.8% and 88.4%, the Balanophora genomes are the most AT-rich genomes known save for a single mitochondrial genome that is merely bloated with AT-rich spacer DNA. Most plastid protein genes in Balanophora consist of ≥90% AT, with several between 95% and 98% AT, resulting in the most biased codon usage in any genome described to date. A potential consequence of its radical compositional evolution is the novel genetic code used by Balanophora plastids, in which TAG has been reassigned from stop to tryptophan. Despite its many exceptional properties, the Balanophora plastome must be functional because all examined genes are transcribed, its only intron is correctly trans-spliced, and its protein genes, although highly divergent, are evolving under various degrees of selective constraint.
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Affiliation(s)
- Huei-Jiun Su
- Department of Earth and Life Sciences, University of Taipei, 100 Taipei, Taiwan
- Department of Biology, Pennsylvania State University, University Park, PA 16802
- Institute of Molecular Evolutionary Genetics, Pennsylvania State University, University Park, PA 16802
| | - Todd J Barkman
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008
| | - Weilong Hao
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202
| | - Samuel S Jones
- Graduate Program in Plant Biology, Pennsylvania State University, University Park, PA 16802
| | - Julia Naumann
- Department of Biology, Pennsylvania State University, University Park, PA 16802
- Institute of Molecular Evolutionary Genetics, Pennsylvania State University, University Park, PA 16802
| | | | - Eric K Wafula
- Department of Biology, Pennsylvania State University, University Park, PA 16802
- Institute of Molecular Evolutionary Genetics, Pennsylvania State University, University Park, PA 16802
| | - Jer-Ming Hu
- Institute of Ecology and Evolutionary Biology, National Taiwan University, 106 Taipei, Taiwan
| | - Jeffrey D Palmer
- Department of Biology, Indiana University, Bloomington, IN 47405;
| | - Claude W dePamphilis
- Department of Biology, Pennsylvania State University, University Park, PA 16802;
- Institute of Molecular Evolutionary Genetics, Pennsylvania State University, University Park, PA 16802
- Graduate Program in Plant Biology, Pennsylvania State University, University Park, PA 16802
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39
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Zoschke R, Bock R. Chloroplast Translation: Structural and Functional Organization, Operational Control, and Regulation. THE PLANT CELL 2018; 30:745-770. [PMID: 29610211 PMCID: PMC5969280 DOI: 10.1105/tpc.18.00016] [Citation(s) in RCA: 140] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/26/2018] [Accepted: 04/01/2018] [Indexed: 05/20/2023]
Abstract
Chloroplast translation is essential for cellular viability and plant development. Its positioning at the intersection of organellar RNA and protein metabolism makes it a unique point for the regulation of gene expression in response to internal and external cues. Recently obtained high-resolution structures of plastid ribosomes, the development of approaches allowing genome-wide analyses of chloroplast translation (i.e., ribosome profiling), and the discovery of RNA binding proteins involved in the control of translational activity have greatly increased our understanding of the chloroplast translation process and its regulation. In this review, we provide an overview of the current knowledge of the chloroplast translation machinery, its structure, organization, and function. In addition, we summarize the techniques that are currently available to study chloroplast translation and describe how translational activity is controlled and which cis-elements and trans-factors are involved. Finally, we discuss how translational control contributes to the regulation of chloroplast gene expression in response to developmental, environmental, and physiological cues. We also illustrate the commonalities and the differences between the chloroplast and bacterial translation machineries and the mechanisms of protein biosynthesis in these two prokaryotic systems.
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Affiliation(s)
- Reimo Zoschke
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam, Germany
| | - Ralph Bock
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam, Germany
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40
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de Santana Lopes A, Gomes Pacheco T, Nimz T, do Nascimento Vieira L, Guerra MP, Nodari RO, de Souza EM, de Oliveira Pedrosa F, Rogalski M. The complete plastome of macaw palm [Acrocomia aculeata (Jacq.) Lodd. ex Mart.] and extensive molecular analyses of the evolution of plastid genes in Arecaceae. PLANTA 2018; 247:1011-1030. [PMID: 29340796 DOI: 10.1007/s00425-018-2841-x] [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: 11/01/2017] [Accepted: 01/10/2018] [Indexed: 05/08/2023]
Abstract
The plastome of macaw palm was sequenced allowing analyses of evolution and molecular markers. Additionally, we demonstrated that more than half of plastid protein-coding genes in Arecaceae underwent positive selection. Macaw palm is a native species from tropical and subtropical Americas. It shows high production of oil per hectare reaching up to 70% of oil content in fruits and an interesting plasticity to grow in different ecosystems. Its domestication and breeding are still in the beginning, which makes the development of molecular markers essential to assess natural populations and germplasm collections. Therefore, we sequenced and characterized in detail the plastome of macaw palm. A total of 221 SSR loci were identified in the plastome of macaw palm. Additionally, eight polymorphism hotspots were characterized at level of subfamily and tribe. Moreover, several events of gain and loss of RNA editing sites were found within the subfamily Arecoideae. Aiming to uncover evolutionary events in Arecaceae, we also analyzed extensively the evolution of plastid genes. The analyses show that highly divergent genes seem to evolve in a species-specific manner, suggesting that gene degeneration events may be occurring within Arecaceae at the level of genus or species. Unexpectedly, we found that more than half of plastid protein-coding genes are under positive selection, including genes for photosynthesis, gene expression machinery and other essential plastid functions. Furthermore, we performed a phylogenomic analysis using whole plastomes of 40 taxa, representing all subfamilies of Arecaceae, which placed the macaw palm within the tribe Cocoseae. Finally, the data showed here are important for genetic studies in macaw palm and provide new insights into the evolution of plastid genes and environmental adaptation in Arecaceae.
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Affiliation(s)
- Amanda de Santana Lopes
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Túlio Gomes Pacheco
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Tabea Nimz
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Leila do Nascimento Vieira
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Miguel P Guerra
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Rubens O Nodari
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Emanuel Maltempi de Souza
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Fábio de Oliveira Pedrosa
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Marcelo Rogalski
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
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41
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Gawroński P, Jensen PE, Karpiński S, Leister D, Scharff LB. Pausing of Chloroplast Ribosomes Is Induced by Multiple Features and Is Linked to the Assembly of Photosynthetic Complexes. PLANT PHYSIOLOGY 2018; 176:2557-2569. [PMID: 29298822 PMCID: PMC5841727 DOI: 10.1104/pp.17.01564] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/02/2018] [Indexed: 05/11/2023]
Abstract
Many mRNAs contain pause sites that briefly interrupt the progress of translation. Specific features that induce ribosome pausing have been described; however, their individual contributions to pause-site formation, and the overall biological significance of ribosome pausing, remain largely unclear. We have taken advantage of the compact genome of chloroplasts to carry out a plastid genome-wide survey of pause sites, as a basis for studying the impact of pausing on posttranslational processes. Based on ribosomal profiling of Arabidopsis (Arabidopsis thaliana) chloroplast mRNAs, we demonstrate that a combination of factors-mRNA secondary structure, internal Shine-Dalgarno sequences, and positively charged amino acids in the nascent peptide chain-explains 95% of the major pause sites on plastid mRNAs, whereas codon usage has little impact. The distribution of the pause sites is nonrandom and conforms to distinct patterns in the vicinity of sequences coding for transmembrane domains, which depend on their orientation within the membrane as well as being next to sequences coding for cofactor binding sites. We found strong indications that the mechanisms causing ribosomal pausing and at least some of the ribosomes pause sites are conserved between distantly related plant species. In addition, the positions of features that cause pausing are well conserved in photoautotrophic plants, but less so in their nonphotosynthetic, parasitic relatives, implying that the synthesis and assembly of photosynthetic multiprotein complexes requires localized ribosome pausing.
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Affiliation(s)
- Piotr Gawroński
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark
- Department of Plant Genetics, Breeding and Biotechnology, Warsaw University of Life Sciences, 02-776 Warsaw, Poland
| | - Poul Erik Jensen
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark
| | - Stanisław Karpiński
- Department of Plant Genetics, Breeding and Biotechnology, Warsaw University of Life Sciences, 02-776 Warsaw, Poland
- Plant Breeding and Acclimatization Institute, National Research Institute, Radzików, 05-870 Błonie, Poland
| | - Dario Leister
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark
- Plant Molecular Biology, Department Biology I, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Lars B Scharff
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark
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de Santana Lopes A, Pacheco TG, Santos KGD, Vieira LDN, Guerra MP, Nodari RO, de Souza EM, de Oliveira Pedrosa F, Rogalski M. The Linum usitatissimum L. plastome reveals atypical structural evolution, new editing sites, and the phylogenetic position of Linaceae within Malpighiales. PLANT CELL REPORTS 2018; 37:307-328. [PMID: 29086003 DOI: 10.1007/s00299-017-2231-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 10/18/2017] [Indexed: 05/12/2023]
Abstract
The plastome of Linum usitatissimum was completely sequenced allowing analyses of evolution of genome structure, RNA editing sites, molecular markers, and indicating the position of Linaceae within Malpighiales. Flax (Linum usitatissimum L.) is an economically important crop used as food, feed, and industrial feedstock. It belongs to the Linaceae family, which is noted by high morphological and ecological diversity. Here, we reported the complete sequence of flax plastome, the first species within Linaceae family to have the plastome sequenced, assembled and characterized in detail. The plastome of flax is a circular DNA molecule of 156,721 bp with a typical quadripartite structure including two IRs of 31,990 bp separating the LSC of 81,767 bp and the SSC of 10,974 bp. It shows two expansion events from IRB to LSC and from IRB to SSC, and a contraction event in the IRA-LSC junction, which changed significantly the size and the gene content of LSC, SSC and IRs. We identified 109 unique genes and 2 pseudogenes (rpl23 and ndhF). The plastome lost the conserved introns of clpP gene and the complete sequence of rps16 gene. The clpP, ycf1, and ycf2 genes show high nucleotide and aminoacid divergence, but they still possibly retain the functionality. Moreover, we also identified 176 SSRs, 20 tandem repeats, and 39 dispersed repeats. We predicted in 18 genes a total of 53 RNA editing sites of which 32 were not found before in other species. The phylogenetic inference based on 63 plastid protein-coding genes of 38 taxa supports three major clades within Malpighiales order. One of these clades has flax (Linaceae) sister to Chrysobalanaceae family, differing from earlier studies that included Linaceae into the euphorbioid clade.
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Affiliation(s)
- Amanda de Santana Lopes
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Túlio Gomes Pacheco
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Karla Gasparini Dos Santos
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Leila do Nascimento Vieira
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Miguel Pedro Guerra
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Rubens Onofre Nodari
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Emanuel Maltempi de Souza
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Fábio de Oliveira Pedrosa
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Marcelo Rogalski
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
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43
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Qu Y, Legen J, Arndt J, Henkel S, Hoppe G, Thieme C, Ranzini G, Muino JM, Weihe A, Ohler U, Weber G, Ostersetzer O, Schmitz-Linneweber C. Ectopic Transplastomic Expression of a Synthetic MatK Gene Leads to Cotyledon-Specific Leaf Variegation. FRONTIERS IN PLANT SCIENCE 2018; 9:1453. [PMID: 30337934 PMCID: PMC6180158 DOI: 10.3389/fpls.2018.01453] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 09/12/2018] [Indexed: 05/20/2023]
Abstract
Chloroplasts (and other plastids) harbor their own genetic material, with a bacterial-like gene-expression systems. Chloroplast RNA metabolism is complex and is predominantly mediated by nuclear-encoded RNA-binding proteins. In addition to these nuclear factors, the chloroplast-encoded intron maturase MatK has been suggested to perform as a splicing factor for a subset of chloroplast introns. MatK is essential for plant cell survival in tobacco, and thus null mutants have not yet been isolated. We therefore attempted to over-express MatK from a neutral site in the chloroplast, placing it under the control of a theophylline-inducible riboswitch. This ectopic insertion of MatK lead to a variegated cotyledons phenotype. The addition of the inducer theophylline exacerbated the phenotype in a concentration-dependent manner. The extent of variegation was further modulated by light, sucrose and spectinomycin, suggesting that the function of MatK is intertwined with photosynthesis and plastid translation. Inhibiting translation in the transplastomic lines has a profound effect on the accumulation of several chloroplast mRNAs, including the accumulation of an RNA antisense to rpl33, a gene coding for an essential chloroplast ribosomal protein. Our study further supports the idea that MatK expression needs to be tightly regulated to prevent detrimental effects and establishes another link between leaf variegation and chloroplast translation.
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Affiliation(s)
- Yujiao Qu
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Julia Legen
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Jürgen Arndt
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Stephanie Henkel
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Galina Hoppe
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | | | - Giovanna Ranzini
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Jose M. Muino
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Andreas Weihe
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Uwe Ohler
- Computational Regulatory Genomics, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Gert Weber
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie, Joint Research Group Macromolecular Crystallography, Berlin, Germany
| | - Oren Ostersetzer
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Christian Schmitz-Linneweber
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
- *Correspondence: Christian Schmitz-Linneweber,
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Scharff LB, Ehrnthaler M, Janowski M, Childs LH, Hasse C, Gremmels J, Ruf S, Zoschke R, Bock R. Shine-Dalgarno Sequences Play an Essential Role in the Translation of Plastid mRNAs in Tobacco. THE PLANT CELL 2017; 29:3085-3101. [PMID: 29133466 PMCID: PMC5757275 DOI: 10.1105/tpc.17.00524] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 10/27/2017] [Accepted: 11/08/2017] [Indexed: 05/23/2023]
Abstract
In prokaryotic systems, the translation initiation of many, though not all, mRNAs depends on interaction between a sequence element upstream of the start codon (the Shine-Dalgarno sequence [SD]) and a complementary sequence in the 3' end of the 16S rRNA (anti-Shine-Dalgarno sequence [aSD]). Although many chloroplast mRNAs harbor putative SDs in their 5' untranslated regions and the aSD displays strong conservation, the functional relevance of SD-aSD interactions in plastid translation is unclear. Here, by generating transplastomic tobacco (Nicotiana tabacum) mutants with point mutations in the aSD coupled with genome-wide analysis of translation by ribosome profiling, we provide a global picture of SD-dependent translation in plastids. We observed a pronounced correlation between weakened predicted SD-aSD interactions and reduced translation efficiency. However, multiple lines of evidence suggest that the strength of the SD-aSD interaction is not the only determinant of the translational output of many plastid mRNAs. Finally, the translation efficiency of mRNAs with strong secondary structures around the start codon is more dependent on the SD-aSD interaction than weakly structured mRNAs. Thus, our data reveal the importance of the aSD in plastid translation initiation, uncover chloroplast genes whose translation is influenced by SD-aSD interactions, and provide insights into determinants of translation efficiency in plastids.
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Affiliation(s)
- Lars B Scharff
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Miriam Ehrnthaler
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Marcin Janowski
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Liam H Childs
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Claudia Hasse
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Jürgen Gremmels
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Reimo Zoschke
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
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45
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Biosynthesis of Sulfur-Containing tRNA Modifications: A Comparison of Bacterial, Archaeal, and Eukaryotic Pathways. Biomolecules 2017; 7:biom7010027. [PMID: 28287455 PMCID: PMC5372739 DOI: 10.3390/biom7010027] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/03/2017] [Accepted: 03/06/2017] [Indexed: 01/12/2023] Open
Abstract
Post-translational tRNA modifications have very broad diversity and are present in all domains of life. They are important for proper tRNA functions. In this review, we emphasize the recent advances on the biosynthesis of sulfur-containing tRNA nucleosides including the 2-thiouridine (s2U) derivatives, 4-thiouridine (s4U), 2-thiocytidine (s2C), and 2-methylthioadenosine (ms2A). Their biosynthetic pathways have two major types depending on the requirement of iron–sulfur (Fe–S) clusters. In all cases, the first step in bacteria and eukaryotes is to activate the sulfur atom of free l-cysteine by cysteine desulfurases, generating a persulfide (R-S-SH) group. In some archaea, a cysteine desulfurase is missing. The following steps of the bacterial s2U and s4U formation are Fe–S cluster independent, and the activated sulfur is transferred by persulfide-carrier proteins. By contrast, the biosynthesis of bacterial s2C and ms2A require Fe–S cluster dependent enzymes. A recent study shows that the archaeal s4U synthetase (ThiI) and the eukaryotic cytosolic 2-thiouridine synthetase (Ncs6) are Fe–S enzymes; this expands the role of Fe–S enzymes in tRNA thiolation to the Archaea and Eukarya domains. The detailed reaction mechanisms of Fe–S cluster depend s2U and s4U formation await further investigations.
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46
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Barahimipour R, Strenkert D, Neupert J, Schroda M, Merchant SS, Bock R. Dissecting the contributions of GC content and codon usage to gene expression in the model alga Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 84:704-17. [PMID: 26402748 PMCID: PMC4715772 DOI: 10.1111/tpj.13033] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 08/24/2015] [Accepted: 09/14/2015] [Indexed: 05/17/2023]
Abstract
The efficiency of gene expression in all organisms depends on the nucleotide composition of the coding region. GC content and codon usage are the two key sequence features known to influence gene expression, but the underlying molecular mechanisms are not entirely clear. Here we have determined the relative contributions of GC content and codon usage to the efficiency of nuclear gene expression in the unicellular green alga Chlamydomonas reinhardtii. By comparing gene variants that encode an identical amino acid sequence but differ in their GC content and/or codon usage, we show that codon usage is the key factor determining translational efficiency and, surprisingly, also mRNA stability. By contrast, unfavorable GC content affects gene expression at the level of the chromatin structure by triggering heterochromatinization. We further show that mutant algal strains that permit high-level transgene expression are less susceptible to epigenetic transgene suppression and do not establish a repressive chromatin structure at the transgenic locus. Our data disentangle the relationship between GC content and codon usage, and suggest simple strategies to overcome the transgene expression problem in Chlamydomonas.
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Affiliation(s)
- Rouhollah Barahimipour
- Max-Planck-Institut für Molekulare Pflanzenphysiologie (MPI-MP), Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Daniela Strenkert
- University of California Los Angeles, Department of Chemistry and Biochemistry, and Institute for Genomics and Proteomics, 607 Charles E. Young Dr. East, Los Angeles, California 90095, USA
| | - Juliane Neupert
- Max-Planck-Institut für Molekulare Pflanzenphysiologie (MPI-MP), Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Michael Schroda
- Max-Planck-Institut für Molekulare Pflanzenphysiologie (MPI-MP), Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Sabeeha S. Merchant
- University of California Los Angeles, Department of Chemistry and Biochemistry, and Institute for Genomics and Proteomics, 607 Charles E. Young Dr. East, Los Angeles, California 90095, USA
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie (MPI-MP), Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
- For correspondence (Fax: +49-331-567-8701; )
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Distribution of ADAT-Dependent Codons in the Human Transcriptome. Int J Mol Sci 2015; 16:17303-14. [PMID: 26230688 PMCID: PMC4581194 DOI: 10.3390/ijms160817303] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 07/02/2015] [Accepted: 07/06/2015] [Indexed: 12/21/2022] Open
Abstract
Nucleotide modifications in the anticodons of transfer RNAs (tRNA) play a central role in translation efficiency, fidelity, and regulation of translation, but, for most of these modifications, the details of their function remain unknown. The heterodimeric adenosine deaminases acting on tRNAs (ADAT2-ADAT3, or ADAT) are enzymes present in eukaryotes that convert adenine (A) to inosine (I) in the first anticodon base (position 34) by hydrolytic deamination. To explore the influence of ADAT activity on mammalian translation, we have characterized the human transcriptome and proteome in terms of frequency and distribution of ADAT-related codons. Eight different tRNAs can be modified by ADAT and, once modified, these tRNAs will recognize NNC, NNU and NNA codons, but not NNG codons. We find that transcripts coding for proteins highly enriched in these eight amino acids (ADAT-aa) are specifically enriched in NNC, NNU and NNA codons. We also show that the proteins most enriched in ADAT-aa are composed preferentially of threonine, alanine, proline, and serine (TAPS). We propose that the enrichment in ADAT-codons in these proteins is due to the similarities in the codons that correspond to TAPS.
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48
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Zhou W, Karcher D, Fischer A, Maximova E, Walther D, Bock R. Multiple RNA processing defects and impaired chloroplast function in plants deficient in the organellar protein-only RNase P enzyme. PLoS One 2015; 10:e0120533. [PMID: 25793367 PMCID: PMC4368725 DOI: 10.1371/journal.pone.0120533] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 01/23/2015] [Indexed: 01/22/2023] Open
Abstract
Transfer RNA (tRNA) precursors undergo endoribonucleolytic processing of their 5’ and 3’ ends. 5’ cleavage of the precursor transcript is performed by ribonuclease P (RNase P). While in most organisms RNase P is a ribonucleoprotein that harbors a catalytically active RNA component, human mitochondria and the chloroplasts (plastids) and mitochondria of seed plants possess protein-only RNase P enzymes (PRORPs). The plant organellar PRORP (PRORP1) has been characterized to some extent in vitro and by transient gene silencing, but the molecular, phenotypic and physiological consequences of its down-regulation in stable transgenic plants have not been assessed. Here we have addressed the function of the dually targeted organellar PRORP enzyme in vivo by generating stably transformed Arabidopsis plants in which expression of the PRORP1 gene was suppressed by RNA interference (RNAi). PRORP1 knock-down lines show defects in photosynthesis, while mitochondrial respiration is not appreciably affected. In both plastids and mitochondria, the effects of PRORP1 knock-down on the processing of individual tRNA species are highly variable. The drastic reduction in the levels of mature plastid tRNA-Phe(GAA) and tRNA-Arg(ACG) suggests that these two tRNA species limit plastid gene expression in the PRORP1 mutants and, hence, are causally responsible for the mutant phenotype.
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Affiliation(s)
- Wenbin Zhou
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Daniel Karcher
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Axel Fischer
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Eugenia Maximova
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Dirk Walther
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm, Germany
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Bock R. Engineering plastid genomes: methods, tools, and applications in basic research and biotechnology. ANNUAL REVIEW OF PLANT BIOLOGY 2015; 66:211-41. [PMID: 25494465 DOI: 10.1146/annurev-arplant-050213-040212] [Citation(s) in RCA: 218] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The small bacterial-type genome of the plastid (chloroplast) can be engineered by genetic transformation, generating cells and plants with transgenic plastid genomes, also referred to as transplastomic plants. The transformation process relies on homologous recombination, thereby facilitating the site-specific alteration of endogenous plastid genes as well as the precisely targeted insertion of foreign genes into the plastid DNA. The technology has been used extensively to analyze chloroplast gene functions and study plastid gene expression at all levels in vivo. Over the years, a large toolbox has been assembled that is now nearly comparable to the techniques available for plant nuclear transformation and that has enabled new applications of transplastomic technology in basic and applied research. This review describes the state of the art in engineering the plastid genomes of algae and land plants (Embryophyta). It provides an overview of the existing tools for plastid genome engineering, discusses current technological limitations, and highlights selected applications that demonstrate the immense potential of chloroplast transformation in several key areas of plant biotechnology.
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Affiliation(s)
- Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany;
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50
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Rogalski M, do Nascimento Vieira L, Fraga HP, Guerra MP. Plastid genomics in horticultural species: importance and applications for plant population genetics, evolution, and biotechnology. FRONTIERS IN PLANT SCIENCE 2015; 6:586. [PMID: 26284102 PMCID: PMC4520007 DOI: 10.3389/fpls.2015.00586] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 07/15/2015] [Indexed: 05/20/2023]
Abstract
During the evolution of the eukaryotic cell, plastids, and mitochondria arose from an endosymbiotic process, which determined the presence of three genetic compartments into the incipient plant cell. After that, these three genetic materials from host and symbiont suffered several rearrangements, bringing on a complex interaction between nuclear and organellar gene products. Nowadays, plastids harbor a small genome with ∼130 genes in a 100-220 kb sequence in higher plants. Plastid genes are mostly highly conserved between plant species, being useful for phylogenetic analysis in higher taxa. However, intergenic spacers have a relatively higher mutation rate and are important markers to phylogeographical and plant population genetics analyses. The predominant uniparental inheritance of plastids is like a highly desirable feature for phylogeny studies. Moreover, the gene content and genome rearrangements are efficient tools to capture and understand evolutionary events between different plant species. Currently, genetic engineering of the plastid genome (plastome) offers a number of attractive advantages as high-level of foreign protein expression, marker gene excision, gene expression in operon and transgene containment because of maternal inheritance of plastid genome in most crops. Therefore, plastid genome can be used for adding new characteristics related to synthesis of metabolic compounds, biopharmaceutical, and tolerance to biotic and abiotic stresses. Here, we describe the importance and applications of plastid genome as tools for genetic and evolutionary studies, and plastid transformation focusing on increasing the performance of horticultural species in the field.
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Affiliation(s)
- Marcelo Rogalski
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de ViçosaViçosa, Brazil
| | - Leila do Nascimento Vieira
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-graduação em Recursos Genéticos Vegetais, Centro de Ciências Agrárias, Universidade Federal de Santa CatarinaFlorianópolis, Brazil
| | - Hugo P. Fraga
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-graduação em Recursos Genéticos Vegetais, Centro de Ciências Agrárias, Universidade Federal de Santa CatarinaFlorianópolis, Brazil
| | - Miguel P. Guerra
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-graduação em Recursos Genéticos Vegetais, Centro de Ciências Agrárias, Universidade Federal de Santa CatarinaFlorianópolis, Brazil
- *Correspondence: Miguel P. Guerra, Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-graduação em Recursos Genéticos Vegetais, Centro de Ciências Agrárias, Universidade Federal de Santa Catarina, Rod. Admar Gonzaga, 1346 Florianópolis, SC 88034-000, Brazil,
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