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Phytochemical Analysis and Molecular Identification of Green Macroalgae Caulerpa spp. from Bali, Indonesia. Molecules 2022; 27:molecules27154879. [PMID: 35956828 PMCID: PMC9370202 DOI: 10.3390/molecules27154879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 12/04/2022] Open
Abstract
The studies of the Bulung Boni and Bulung Anggur (Caulerpa spp.) species and secondary metabolites are still very limited. Proper identification will support various aspects, such as cultivation, utilization, and economic interests. Moreover, understanding the secondary metabolites will assist in developing algae-based products. This study aimed to identify these indigenous Caulerpa algae and analyze their bioactive components. The tufA sequence was employed as a molecular marker in DNA barcoding, and its bioactive components were identified using the GC-MS method. The phylogenetic tree was generated in MEGA 11 using the maximum likelihood method, and the robustness of the tree was evaluated using bootstrapping with 1000 replicates. This study revealed that Bulung Boni is strongly connected to Caulerpa cylindracea. However, Bulung Anggur shows no close relationship to other Caulerpa species. GC-MS analysis of ethanolic extracts of Bulung Boni and Bulung Anggur showed the presence of 11 and 13 compounds, respectively. The majority of the compounds found in these algae have been shown to possess biological properties, such as antioxidant, antibacterial, anticancer, anti-inflammation, and antidiabetic. Further study is necessary to compare the data obtained using different molecular markers in DNA barcoding, and to elucidate other undisclosed compounds in these Caulerpa algae.
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Sadamitsu A, Inoue Y, Sakakibara K, Tsubota H, Yamaguchi T, Deguchi H, Nishiyama T, Shimamura M. The complete plastid genome sequence of the enigmatic moss, Takakia lepidozioides (Takakiopsida, Bryophyta): evolutionary perspectives on the largest collection of genes in mosses and the intensive RNA editing. PLANT MOLECULAR BIOLOGY 2021; 107:431-449. [PMID: 34817767 DOI: 10.1007/s11103-021-01214-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 11/03/2021] [Indexed: 06/13/2023]
Abstract
Complete chloroplast genome sequence of a moss, Takakia lepidozioides (Takakiopsida) is reported. The largest collection of genes in mosses and the intensive RNA editing were discussed from evolutionary perspectives. We assembled the entire plastid genome sequence of Takakia lepidozioides (Takakiopsida), emerging from the first phylogenetic split among extant mosses. The genome sequences were assembled into a circular molecule 149,016 bp in length, with a quadripartite structure comprising a large and a small single-copy region separated by inverted repeats. It contained 88 genes coding for proteins, 32 for tRNA, four for rRNA, two open reading frames, and at least one pseudogene (tufA). This is the largest number of genes of all sequenced plastid genomes in mosses and Takakia is the only moss that retains the seven coding genes ccsA, cysA, cysT, petN rpoA, rps16 and trnPGGG. Parsimonious interpretation of gene loss suggests that the last common ancestor of bryophytes had all seven genes and that mosses lost at least three of them during their diversification. Analyses of the plastid transcriptome identified the extraordinary frequency of RNA editing with more than 1100 sites. We indicated a close correlation between the monoplastidy of vegetative tissue and the intensive RNA editing sites in the plastid genome in land plant lineages. Here, we proposed a hypothesis that the small population size of plastids in each vegetative cell of some early diverging land plants, including Takakia, might cause the frequent fixation of mutations in plastid genome through the intracellular genetic drift and that deleterious mutations might be continuously compensated by RNA editing during or following transcription.
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Affiliation(s)
- Atsushi Sadamitsu
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-hiroshima, Hiroshima, 739-8526, Japan
| | - Yuya Inoue
- Department of Botany, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki, 305-0005, Japan
- Hattori Botanical Laboratory, 6-1-26 Obi, Nichinan, Miyazaki, 889-2535, Japan
| | - Keiko Sakakibara
- Department of Life Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo, 171-8501, Japan
| | - Hiromi Tsubota
- Miyajima Natural Botanical Garden, Graduate School of Integrated Sciences for Life, Hiroshima University, 1156-2, Mitsumaruko-yama, Miyajima-cho, Hatsukaichi, Hiroshima, 739-0543, Japan
| | - Tomio Yamaguchi
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-hiroshima, Hiroshima, 739-8526, Japan
| | - Hironori Deguchi
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-hiroshima, Hiroshima, 739-8526, Japan
| | - Tomoaki Nishiyama
- Research Center for Experimental Modeling of Human Disease, Kanazawa University, Kanazawa, 920-0934, Japan
| | - Masaki Shimamura
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-hiroshima, Hiroshima, 739-8526, Japan.
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Gateau H, Blanckaert V, Veidl B, Burlet-Schiltz O, Pichereaux C, Gargaros A, Marchand J, Schoefs B. Application of pulsed electric fields for the biocompatible extraction of proteins from the microalga Haematococcus pluvialis. Bioelectrochemistry 2020; 137:107588. [PMID: 33147566 DOI: 10.1016/j.bioelechem.2020.107588] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 06/23/2020] [Accepted: 06/25/2020] [Indexed: 12/19/2022]
Abstract
This study aims to employ a pulsed electric field (PEF) treatment for the biocompatible (non-destructive) extraction of proteins from living cells of the green microalga Haematococcus pluvialis. Using a field strength of 1 kV cm-1, we achieved the extraction of 10.2 µg protein per mL of culture, which corresponded to 46% of the total amount of proteins that could be extracted by complete destructive extraction (i.e. the grinding of biomass with glass beads). We found that the extraction yield was not improved by stronger field strengths and was not dependent on the pulse frequency. A biocompatibility index (BI) was defined as the relative abundance of cells that remained alive after the PEF treatment. This index relied on measurements of several physiological parameters after a PEF treatment. It was found that at 1 kV cm-1 that cultures recovered after 72 h. Therefore, these PEF conditions constituted a good compromise between protein extraction efficiency and culture survival. To characterize the PEF treatment further at a molecular level, mass spectrometry-based proteomics analyses of PEF-prepared extracts was used. This led to the identification of 52 electro-extracted proteins. Of these, only 16 proteins were identified when proteins were extracted with PEF at 0.5 cm-1. They belong to core metabolism, stress response and cell movement. Unassigned proteins were also extracted. Their physiological implications and possible utilization in food as alimentary complements are discussed.
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Affiliation(s)
- Hélène Gateau
- Metabolism, Bioengineering of Molecules from Microalgae and Applications (MIMMA), Mer Molécules Santé, IUML - FR 3473 CNRS, Le Mans University, Le Mans, France
| | - Vincent Blanckaert
- Metabolism, Bioengineering of Molecules from Microalgae and Applications (MIMMA), Mer Molécules Santé, IUML - FR 3473 CNRS, IUT de Laval, Le Mans University, Le Mans, France
| | - Brigitte Veidl
- Metabolism, Bioengineering of Molecules from Microalgae and Applications (MIMMA), Mer Molécules Santé, IUML - FR 3473 CNRS, Le Mans University, Le Mans, France
| | - Odile Burlet-Schiltz
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse UPS, CNRS, Toulouse, France
| | - Carole Pichereaux
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse UPS, CNRS, Toulouse, France; Fédération de Recherche (FR3450), Agrobiosciences, Interactions et Biodiversité (FRAIB), CNRS, Toulouse, France
| | | | - Justine Marchand
- Metabolism, Bioengineering of Molecules from Microalgae and Applications (MIMMA), Mer Molécules Santé, IUML - FR 3473 CNRS, Le Mans University, Le Mans, France
| | - Benoît Schoefs
- Metabolism, Bioengineering of Molecules from Microalgae and Applications (MIMMA), Mer Molécules Santé, IUML - FR 3473 CNRS, Le Mans University, Le Mans, France.
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Huang YY, Cho ST, Haryono M, Kuo CH. Complete chloroplast genome sequence of common bermudagrass (Cynodon dactylon (L.) Pers.) and comparative analysis within the family Poaceae. PLoS One 2017; 12:e0179055. [PMID: 28617867 PMCID: PMC5472289 DOI: 10.1371/journal.pone.0179055] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 05/23/2017] [Indexed: 02/02/2023] Open
Abstract
Common bermudagrass (Cynodon dactylon (L.) Pers.) belongs to the subfamily Chloridoideae of the Poaceae family, one of the most important plant families ecologically and economically. This grass has a long connection with human culture but its systematics is relatively understudied. In this study, we sequenced and investigated the chloroplast genome of common bermudagrass, which is 134,297 bp in length with two single copy regions (LSC: 79,732 bp; SSC: 12,521 bp) and a pair of inverted repeat (IR) regions (21,022 bp). The annotation contains a total of 128 predicted genes, including 82 protein-coding, 38 tRNA, and 8 rRNA genes. Additionally, our in silico analyses identified 10 sets of repeats longer than 20 bp and predicted the presence of 36 RNA editing sites. Overall, the chloroplast genome of common bermudagrass resembles those from other Poaceae lineages. Compared to most angiosperms, the accD gene and the introns of both clpP and rpoC1 genes are missing. Additionally, the ycf1, ycf2, ycf15, and ycf68 genes are pseudogenized and two genome rearrangements exist. Our phylogenetic analysis based on 47 chloroplast protein-coding genes supported the placement of common bermudagrass within Chloridoideae. Our phylogenetic character mapping based on the parsimony principle further indicated that the loss of the accD gene and clpP introns, the pseudogenization of four ycf genes, and the two rearrangements occurred only once after the most recent common ancestor of the Poaceae diverged from other monocots, which could explain the unusual long branch leading to the Poaceae when phylogeny is inferred based on chloroplast sequences.
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Affiliation(s)
- Ya-Yi Huang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Shu-Ting Cho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Mindia Haryono
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
- * E-mail:
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de Vries J, Stanton A, Archibald JM, Gould SB. Streptophyte Terrestrialization in Light of Plastid Evolution. TRENDS IN PLANT SCIENCE 2016; 21:467-476. [PMID: 26895731 DOI: 10.1016/j.tplants.2016.01.021] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/19/2016] [Accepted: 01/28/2016] [Indexed: 05/21/2023]
Abstract
Key steps in evolution are often singularities. The emergence of land plants is one such case and it is not immediately apparent why. A recent analysis found that the zygnematophycean algae represent the closest relative to embryophytes. Intriguingly, many exaptations thought essential to conquer land are common among various streptophytes, but zygnematophycean algae share with land plants the transfer of a few plastid genes to the nucleus. Considering the contribution of the chloroplast to terrestrialization highlights potentially novel exaptations that currently remain unexplored. We discuss how the streptophyte chloroplast evolved into what we refer to as the embryoplast, and argue this was as important for terrestrialization by freshwater algae as the host cell-associated exaptations that are usually focused upon.
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Affiliation(s)
- Jan de Vries
- Institute for Molecular Evolution, Heinrich-Heine-University (HHU) Düsseldorf, 40225 Düsseldorf, Germany
| | - Amanda Stanton
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - John M Archibald
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Sven B Gould
- Institute for Molecular Evolution, Heinrich-Heine-University (HHU) Düsseldorf, 40225 Düsseldorf, Germany.
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Lemieux C, Otis C, Turmel M. Comparative Chloroplast Genome Analyses of Streptophyte Green Algae Uncover Major Structural Alterations in the Klebsormidiophyceae, Coleochaetophyceae and Zygnematophyceae. FRONTIERS IN PLANT SCIENCE 2016; 7:697. [PMID: 27252715 PMCID: PMC4877394 DOI: 10.3389/fpls.2016.00697] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 05/06/2016] [Indexed: 05/18/2023]
Abstract
The Streptophyta comprises all land plants and six main lineages of freshwater green algae: Mesostigmatophyceae, Chlorokybophyceae, Klebsormidiophyceae, Charophyceae, Coleochaetophyceae and Zygnematophyceae. Previous comparisons of the chloroplast genome from nine streptophyte algae (including four zygnematophyceans) revealed that, although land plant chloroplast DNAs (cpDNAs) inherited most of their highly conserved structural features from green algal ancestors, considerable cpDNA changes took place during the evolution of the Zygnematophyceae, the sister group of land plants. To gain deeper insights into the evolutionary dynamics of the chloroplast genome in streptophyte algae, we sequenced the cpDNAs of nine additional taxa: two klebsormidiophyceans (Entransia fimbriata and Klebsormidium sp. SAG 51.86), one coleocheatophycean (Coleochaete scutata) and six zygnematophyceans (Cylindrocystis brebissonii, Netrium digitus, Roya obtusa, Spirogyra maxima, Cosmarium botrytis and Closterium baillyanum). Our comparative analyses of these genomes with their streptophyte algal counterparts indicate that the large inverted repeat (IR) encoding the rDNA operon experienced loss or expansion/contraction in all three sampled classes and that genes were extensively shuffled in both the Klebsormidiophyceae and Zygnematophyceae. The klebsormidiophycean genomes boast greatly expanded IRs, with the Entransia 60,590-bp IR being the largest known among green algae. The 206,025-bp Entransia cpDNA, which is one of the largest genome among streptophytes, encodes 118 standard genes, i.e., four additional genes compared to its Klebsormidium flaccidum homolog. We inferred that seven of the 21 group II introns usually found in land plants were already present in the common ancestor of the Klebsormidiophyceae and its sister lineages. At 107,236 bp and with 117 standard genes, the Coleochaete IR-less genome is both the smallest and most compact among the streptophyte algal cpDNAs analyzed thus far; it lacks eight genes relative to its Chaetosphaeridium globosum homolog, four of which represent unique events in the evolutionary scenario of gene losses we reconstructed for streptophyte algae. The 10 compared zygnematophycean cpDNAs display tremendous variations at all levels, except gene content. During zygnematophycean evolution, the IR disappeared a minimum of five times, the rDNA operon was broken at four distinct sites, group II introns were lost on at least 43 occasions, and putative foreign genes, mainly of phage/viral origin, were gained.
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Affiliation(s)
- Claude Lemieux
- Institut de Biologie Intégrative et des Systèmes, Département de Biochimie, de Microbiologie et de Bio-informatique, Université Laval, QuébecQC, Canada
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Idoine AD, Boulouis A, Rupprecht J, Bock R. The diurnal logic of the expression of the chloroplast genome in Chlamydomonas reinhardtii. PLoS One 2014; 9:e108760. [PMID: 25272288 PMCID: PMC4182738 DOI: 10.1371/journal.pone.0108760] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Accepted: 09/04/2014] [Indexed: 12/01/2022] Open
Abstract
Chloroplasts are derived from cyanobacteria and have retained a bacterial-type genome and gene expression machinery. The chloroplast genome encodes many of the core components of the photosynthetic apparatus in the thylakoid membranes. To avoid photooxidative damage and production of harmful reactive oxygen species (ROS) by incompletely assembled thylakoid protein complexes, chloroplast gene expression must be tightly regulated and co-ordinated with gene expression in the nucleus. Little is known about the control of chloroplast gene expression at the genome-wide level in response to internal rhythms and external cues. To obtain a comprehensive picture of organelle transcript levels in the unicellular model alga Chlamydomonas reinhardtii in diurnal conditions, a qRT-PCR platform was developed and used to quantify 68 chloroplast, 21 mitochondrial as well as 71 nuclear transcripts in cells grown in highly controlled 12 h light/12 h dark cycles. Interestingly, in anticipation of dusk, chloroplast transcripts from genes involved in transcription reached peak levels first, followed by transcripts from genes involved in translation, and finally photosynthesis gene transcripts. This pattern matches perfectly the theoretical demands of a cell “waking up” from the night. A similar trend was observed in the nuclear transcripts. These results suggest a striking internal logic in the expression of the chloroplast genome and a previously unappreciated complexity in the regulation of chloroplast genes.
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Affiliation(s)
- Adam D. Idoine
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam, Golm, Germany
| | - Alix Boulouis
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam, Golm, Germany
| | - Jens Rupprecht
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam, Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam, Golm, Germany
- * E-mail:
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Dodd AN, Kusakina J, Hall A, Gould PD, Hanaoka M. The circadian regulation of photosynthesis. PHOTOSYNTHESIS RESEARCH 2014; 119:181-90. [PMID: 23529849 DOI: 10.1007/s11120-013-9811-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Accepted: 03/08/2013] [Indexed: 05/25/2023]
Abstract
Correct circadian regulation increases plant productivity, and photosynthesis is circadian-regulated. Here, we discuss the regulatory basis for the circadian control of photosynthesis. We discuss candidate mechanisms underpinning circadian oscillations of light harvesting and consider how the circadian clock modulates CO2 fixation by Rubisco. We show that new techniques may provide a platform to better understand the signalling pathways that couple the circadian clock with the photosynthetic apparatus. Finally, we discuss how understanding circadian regulation in model systems is underpinning research into the impact of circadian regulation in crop species.
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Affiliation(s)
- Antony N Dodd
- School of Biological Sciences, University of Bristol, Bristol, BS8 1UG, UK,
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Händeler K, Wägele H, Wahrmund U, Rüdinger M, Knoop V. Slugs' last meals: molecular identification of sequestered chloroplasts from different algal origins in Sacoglossa (Opisthobranchia, Gastropoda). Mol Ecol Resour 2013; 10:968-78. [PMID: 21565106 DOI: 10.1111/j.1755-0998.2010.02853.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Some sacoglossan sea slugs have become famous for their unique capability to extract and incorporate functional chloroplasts from algal food organisms (mainly Ulvophyceae) into their gut cells. The functional incorporation of the so-called kleptoplasts allows the slugs to rely on photosynthetic products for weeks to months, enabling them to survive long periods of food shortage over most of their life-span. The algal food spectrum providing kleptoplasts as temporary, non-inherited endosymbionts appears to vary among sacoglossan slugs, but detailed knowledge is sketchy or unavailable. Accurate identification of algal donor species, which provide the chloroplasts for long-term retention is of primary importance to elucidate the biochemical mechanisms allowing long-term functionality of the captured chloroplast in the foreign animal cell environment. Whereas some sacoglossans forage on a variety of algal species, (e.g. Elysia crispata and E. viridis) others are more selective. Hence, characterizing the range of functional sacoglossan-chloroplast associations in nature is a prerequisite to understand the basis of this enigmatic endosymbiosis. Here, we present a suitable chloroplast gene (tufA) as a marker, which allows identification of the respective algal kleptoplast donor taxa by analysing DNA from whole animals. This novel approach allows identification of donor algae on genus or even species level, thus providing evidence for the taxonomic range of food organisms. We report molecular evidence that chloroplasts from different algal sources are simultaneously incorporated in some species of Elysia. NeigborNet analyses for species assignments are preferred over tree reconstruction methods because the former allow more reliable statements on species identification via barcoding, or rather visualize alternative allocations not to be seen in the latter.
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Affiliation(s)
- Katharina Händeler
- Zoologisches Forschungsmuseum Alexander Koenig, Bonn, Germany Institut für Zelluläre und Molekulare Botanik, Bonn, Germany
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Finet C, Timme RE, Delwiche CF, Marlétaz F. Multigene phylogeny of the green lineage reveals the origin and diversification of land plants. Curr Biol 2010; 20:2217-22. [PMID: 21145743 DOI: 10.1016/j.cub.2010.11.035] [Citation(s) in RCA: 133] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 09/25/2010] [Accepted: 11/11/2010] [Indexed: 10/18/2022]
Abstract
The Viridiplantae (green plants) include land plants as well as the two distinct lineages of green algae, chlorophytes and charophytes. Despite their critical importance for identifying the closest living relatives of land plants, phylogenetic studies of charophytes have provided equivocal results [1-5]. In addition, many relationships remain unresolved among the land plants, such as the position of mosses, liverworts, and the enigmatic Gnetales. Phylogenomics has proven to be an insightful approach for resolving challenging phylogenetic issues, particularly concerning deep nodes [6-8]. Here we extend this approach to the green lineage by assembling a multilocus data set of 77 nuclear genes (12,149 unambiguously aligned amino acid positions) from 77 taxa of plants. We therefore provide the first multigene phylogenetic evidence that Coleochaetales represent the closest living relatives of land plants. Moreover, our data reinforce the early divergence of liverworts and the close relationship between Gnetales and Pinaceae. These results provide a new phylogenetic framework and represent a key step in the evolutionary interpretation of developmental and genomic characters in green plants.
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Affiliation(s)
- Cédric Finet
- Howard Hughes Medical Institute and Laboratory of Molecular Biology, University of Wisconsin, 1525 Linden Drive, Madison, WI 53706, USA.
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11
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Karol KG, Arumuganathan K, Boore JL, Duffy AM, Everett KDE, Hall JD, Hansen SK, Kuehl JV, Mandoli DF, Mishler BD, Olmstead RG, Renzaglia KS, Wolf PG. Complete plastome sequences of Equisetum arvense and Isoetes flaccida: implications for phylogeny and plastid genome evolution of early land plant lineages. BMC Evol Biol 2010; 10:321. [PMID: 20969798 PMCID: PMC3087542 DOI: 10.1186/1471-2148-10-321] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Accepted: 10/23/2010] [Indexed: 11/17/2022] Open
Abstract
Background Despite considerable progress in our understanding of land plant phylogeny, several nodes in the green tree of life remain poorly resolved. Furthermore, the bulk of currently available data come from only a subset of major land plant clades. Here we examine early land plant evolution using complete plastome sequences including two previously unexamined and phylogenetically critical lineages. To better understand the evolution of land plants and their plastomes, we examined aligned nucleotide sequences, indels, gene and nucleotide composition, inversions, and gene order at the boundaries of the inverted repeats. Results We present the plastome sequences of Equisetum arvense, a horsetail, and of Isoetes flaccida, a heterosporous lycophyte. Phylogenetic analysis of aligned nucleotides from 49 plastome genes from 43 taxa supported monophyly for the following clades: embryophytes (land plants), lycophytes, monilophytes (leptosporangiate ferns + Angiopteris evecta + Psilotum nudum + Equisetum arvense), and seed plants. Resolution among the four monilophyte lineages remained moderate, although nucleotide analyses suggested that P. nudum and E. arvense form a clade sister to A. evecta + leptosporangiate ferns. Results from phylogenetic analyses of nucleotides were consistent with the distribution of plastome gene rearrangements and with analysis of sequence gaps resulting from insertions and deletions (indels). We found one new indel and an inversion of a block of genes that unites the monilophytes. Conclusions Monophyly of monilophytes has been disputed on the basis of morphological and fossil evidence. In the context of a broad sampling of land plant data we find several new pieces of evidence for monilophyte monophyly. Results from this study demonstrate resolution among the four monilophytes lineages, albeit with moderate support; we posit a clade consisting of Equisetaceae and Psilotaceae that is sister to the "true ferns," including Marattiaceae.
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Affiliation(s)
- Kenneth G Karol
- The Lewis B, and Dorothy Cullman Program for Molecular Systematics Studies, The New York Botanical Garden, Bronx, NY 10458, USA.
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12
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Fu J, Ristic Z. Analysis of transgenic wheat (Triticum aestivum L.) harboring a maize (Zea mays L.) gene for plastid EF-Tu: segregation pattern, expression and effects of the transgene. PLANT MOLECULAR BIOLOGY 2010; 73:339-47. [PMID: 20306118 DOI: 10.1007/s11103-010-9622-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 03/07/2010] [Indexed: 05/22/2023]
Abstract
We previously reported that transgenic wheat (Triticum aestivum L.) carrying a maize (Zea mays L.) gene (Zmeftu1) for chloroplast protein synthesis elongation factor, EF-Tu, displays reduced thermal aggregation of leaf proteins, reduced injury to photosynthetic membranes (thylakoids), and enhanced rate of CO(2) fixation following exposure to heat stress (18 h at 45 degrees C) [Fu et al. in Plant Mol Biol 68:277-288, 2008]. In the current study, we investigated the segregation pattern and expression of the transgene Zmeftu1 and determined the grain yield of transgenic plants after exposure to a brief heat stress (18 h at 45 degrees C). We also assessed thermal aggregation of soluble leaf proteins in transgenic plants, testing the hypothesis that increased levels of EF-Tu will lead to a non-specific protection of leaf proteins against thermal aggregation. The transgenic wheat displayed a single-gene pattern of segregation of Zmeftu1. Zmeftu1 was expressed, and the transgenic plants synthesized and accumulated three anti-EF-Tu cross-reacting polypeptides of similar molecular mass but different pI, suggesting the possibility of posttranslational modification of this protein. The transgenic plants also showed better grain yield after exposure to heat stress compared with their non-transgenic counterparts. Soluble leaf proteins of various molecular masses displayed lower thermal aggregation in transgenic than in non-transgenic wheat. The results suggest that overexpression of chloroplast EF-Tu can be beneficial to wheat tolerance to heat stress. Moreover, the results also support the hypothesis that EF-Tu contributes to heat tolerance by acting as a molecular chaperone and protecting heat-labile proteins from thermal aggregation in a non-specific manner.
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Affiliation(s)
- Jianming Fu
- Department of Agronomy, Kansas State University, Manhattan, KS 66506, USA.
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Fu J, Momcilović I, Clemente TE, Nersesian N, Trick HN, Ristic Z. Heterologous expression of a plastid EF-Tu reduces protein thermal aggregation and enhances CO2 fixation in wheat (Triticum aestivum) following heat stress. PLANT MOLECULAR BIOLOGY 2008; 68:277-88. [PMID: 18622733 DOI: 10.1007/s11103-008-9369-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2008] [Accepted: 06/20/2008] [Indexed: 05/20/2023]
Abstract
Heat stress is a major constraint to wheat production and negatively impacts grain quality, causing tremendous economic losses, and may become a more troublesome factor due to global warming. At the cellular level, heat stress causes denaturation and aggregation of proteins and injury to membranes leading to alterations in metabolic fluxes. Protein aggregation is irreversible, and protection of proteins from thermal aggregation is a strategy a cell uses to tolerate heat stress. Here we report on the development of transgenic wheat (Triticum aestivum) events, expressing a maize gene coding for plastidal protein synthesis elongation factor (EF-Tu), which, compared to non-transgenic plants, display reduced thermal aggregation of leaf proteins, reduced heat injury to photosynthetic membranes (thylakoids), and enhanced rate of CO(2) fixation after exposure to heat stress. The results support the concept that EF-Tu ameliorates negative effects of heat stress by acting as a molecular chaperone. This is the first demonstration of the introduction of a plastidal EF-Tu in plants that leads to protection against heat injury and enhanced photosynthesis after heat stress. This is also the first demonstration that a gene other than HSP gene can be used for improvement of heat tolerance and that the improvement is possible in a species that has a complex genome, hexaploid wheat. The results strongly suggest that heat tolerance of wheat, and possibly other crop plants, can be improved by modulating expression of plastidal EF-Tu and/or by selection of genotypes with increased endogenous levels of this protein.
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Affiliation(s)
- Jianming Fu
- Department of Agronomy, Kansas State University, Manhattan, KS 66506, USA
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14
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Ristic Z, Bukovnik U, Momcilović I, Fu J, Vara Prasad PV. Heat-induced accumulation of chloroplast protein synthesis elongation factor, EF-Tu, in winter wheat. JOURNAL OF PLANT PHYSIOLOGY 2008; 165:192-202. [PMID: 17498838 DOI: 10.1016/j.jplph.2007.03.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Revised: 03/27/2007] [Accepted: 03/28/2007] [Indexed: 05/03/2023]
Abstract
Chloroplast protein synthesis elongation factor, EF-Tu, has been implicated in heat tolerance in maize (Zea mays). Chloroplast EF-Tu is highly conserved, and it is possible that this protein may be of importance to heat tolerance in other species including wheat (Triticum aestivum). In this study, we assessed heat tolerance and determined the relative levels of EF-Tu in mature plants (at flowering stage) of 12 cultivars of winter wheat experiencing a 16-d-long heat treatment (36/30 degrees C, day/night temperature). In addition, we also investigated the expression of EF-Tu in young plants experiencing a short-term heat shock (4h at 43 degrees C). Heat tolerance was assessed by examining the stability of thylakoid membranes, measuring chlorophyll content, and assessing plant growth traits (shoot dry mass, plant height, tiller number, and ear number). In mature plants, relative levels of EF-Tu were determined after 7 d of heat stress. High temperature-induced accumulation of EF-Tu in mature plants of all cultivars, and a group of cultivars that showed greater accumulation of EF-Tu displayed better tolerance to heat stress. Young plants of all cultivars but one did not show significant increases in the relative levels of EF-Tu. The results of the study suggest that EF-Tu protein may play a role in heat tolerance in winter wheat.
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Affiliation(s)
- Zoran Ristic
- United States Department of Agriculture - Agricultural Research Service, Plant Science and Entomology Research Unit, 4008 Throckmorton Hall, Manhattan, KS 66506, USA.
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15
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Momcilovic I, Ristic Z. Expression of chloroplast protein synthesis elongation factor, EF-Tu, in two lines of maize with contrasting tolerance to heat stress during early stages of plant development. JOURNAL OF PLANT PHYSIOLOGY 2007; 164:90-9. [PMID: 16542752 DOI: 10.1016/j.jplph.2006.01.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Accepted: 01/06/2006] [Indexed: 05/03/2023]
Abstract
Maize chloroplast protein synthesis elongation factor, EF-Tu, has been implicated in heat tolerance, and previous studies have shown that under heat stress this protein accumulates in 14-d-, 17-d-, and 21-d-old plants of maize genotypes with increased tolerance to stress. In the present study, we investigated the expression of EF-Tu genes in heat tolerant, ZPBL 1304, and heat sensitive, ZPL 389, maize lines during early stages of their development (5-21-d-old plants) under both control and heat stress conditions. We also investigated the expression of EF-Tu in mature plants of these lines under field conditions and assessed heat tolerance in young seedlings at different stages of their development. The expression of EF-Tu was studied by determining the relative levels of EF-Tu protein and the steady state levels of EF-Tu mRNA. Chloroplast EF-Tu showed differential expression during early stages of plant development, and the heat tolerant and the heat sensitive line differed in the expression of EF-Tu under heat stress. In ZPBL 1304, plants of all ages (except 5-d-old shoots) showed heat-induced accumulation of both EF-Tu transcript and EF-Tu protein. In contrast, in ZPL 389, only plants up to 14d of age displayed increased accumulation of EF-Tu under heat stress. The increase in the relative level of EF-Tu in ZPL 389 was not preceded by an increase in the steady state level of EF-Tu mRNA. Under heat stress, the relative levels of EF-Tu correlated positively with plant heat tolerance. The results are consistent with the hypothesis that maize EF-Tu plays a role in heat tolerance and suggest that under heat stress conditions, the regulation of expression of EF-Tu may be different in the heat tolerant and heat sensitive maize lines.
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Affiliation(s)
- Ivana Momcilovic
- Department of Biology, University of South Dakota, Vermillion, SD 57069, USA
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16
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Turmel M, Otis C, Lemieux C. The chloroplast genome sequence of Chara vulgaris sheds new light into the closest green algal relatives of land plants. Mol Biol Evol 2006; 23:1324-38. [PMID: 16611644 DOI: 10.1093/molbev/msk018] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The phylum Streptophyta comprises all land plants and six monophyletic groups of charophycean green algae (Mesostigmatales, Chlorokybales, Klebsormidiales, Zygnematales, Coleochaetales, and Charales). Phylogenetic analyses of four genes encoded in three cellular compartments suggest that the Charales are sister to land plants and that charophycean green algae evolved progressively toward an increasing cellular complexity. To validate this phylogenetic hypothesis and to understand how and when the highly conservative pattern displayed by land plant chloroplast DNAs (cpDNAs) originated in the Streptophyta, we have determined the complete chloroplast genome sequence (184,933 bp) of a representative of the Charales, Chara vulgaris, and compared this genome to those of Mesostigma (Mesostigmatales), Chlorokybus (Chlorokybales), Staurastrum and Zygnema (Zygnematales), Chaetosphaeridium (Coleochaetales), and selected land plants. The phylogenies we inferred from 76 cpDNA-encoded proteins and genes using various methods favor the hypothesis that the Charales diverged before the Coleochaetales and Zygnematales. The Zygnematales were identified as sister to land plants in the best tree topology (T1), whereas Chaetosphaeridium (T2) or a clade uniting the Zygnematales and Chaetosphaeridium (T3) occupied this position in alternative topologies. Chara remained at the same basal position in trees including more land plant taxa and inferred from 56 proteins/genes. Phylogenetic inference from gene order data yielded two most parsimonious trees displaying the T1 and T3 topologies. Analyses of additional structural cpDNA features (gene order, gene content, intron content, and indels in coding regions) provided better support for T1 than for the topology of the above-mentioned four-gene tree. Our structural analyses also revealed that many of the features conserved in land plant cpDNAs were inherited from their green algal ancestors. The intron content data predicted that at least 15 of the 21 land plant group II introns were gained early during the evolution of streptophytes and that a single intron was acquired during the transition from charophycean green algae to land plants. Analyses of genome rearrangements based on inversions predicted no alteration in gene order during the transition from charophycean green algae to land plants.
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Affiliation(s)
- Monique Turmel
- Département de Biochimie et de Microbiologie, Université Laval, Québec, Canada.
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17
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Yoon HS, Hackett JD, Ciniglia C, Pinto G, Bhattacharya D. A Molecular Timeline for the Origin of Photosynthetic Eukaryotes. Mol Biol Evol 2004; 21:809-18. [PMID: 14963099 DOI: 10.1093/molbev/msh075] [Citation(s) in RCA: 532] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The appearance of photosynthetic eukaryotes (algae and plants) dramatically altered the Earth's ecosystem, making possible all vertebrate life on land, including humans. Dating algal origin is, however, frustrated by a meager fossil record. We generated a plastid multi-gene phylogeny with Bayesian inference and then used maximum likelihood molecular clock methods to estimate algal divergence times. The plastid tree was used as a surrogate for algal host evolution because of recent phylogenetic evidence supporting the vertical ancestry of the plastid in the red, green, and glaucophyte algae. Nodes in the plastid tree were constrained with six reliable fossil dates and a maximum age of 3,500 MYA based on the earliest known eubacterial fossil. Our analyses support an ancient (late Paleoproterozoic) origin of photosynthetic eukaryotes with the primary endosymbiosis that gave rise to the first alga having occurred after the split of the Plantae (i.e., red, green, and glaucophyte algae plus land plants) from the opisthokonts sometime before 1,558 MYA. The split of the red and green algae is calculated to have occurred about 1,500 MYA, and the putative single red algal secondary endosymbiosis that gave rise to the plastid in the cryptophyte, haptophyte, and stramenopile algae (chromists) occurred about 1,300 MYA. These dates, which are consistent with fossil evidence for putative marine algae (i.e., acritarchs) from the early Mesoproterozoic (1,500 MYA) and with a major eukaryotic diversification in the very late Mesoproterozoic and Neoproterozoic, provide a molecular timeline for understanding algal evolution.
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Affiliation(s)
- Hwan Su Yoon
- Department of Biological Sciences and Center for Comparative Genomics, University of Iowa, Iowa, USA
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18
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Turmel M, Otis C, Lemieux C. The chloroplast and mitochondrial genome sequences of the charophyte Chaetosphaeridium globosum: insights into the timing of the events that restructured organelle DNAs within the green algal lineage that led to land plants. Proc Natl Acad Sci U S A 2002; 99:11275-80. [PMID: 12161560 PMCID: PMC123247 DOI: 10.1073/pnas.162203299] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The land plants and their immediate green algal ancestors, the charophytes, form the Streptophyta. There is evidence that both the chloroplast DNA (cpDNA) and mitochondrial DNA (mtDNA) underwent substantial changes in their architecture (intron insertions, gene losses, scrambling in gene order, and genome expansion in the case of mtDNA) during the evolution of streptophytes; however, because no charophyte organelle DNAs have been sequenced completely thus far, the suite of events that shaped streptophyte organelle genomes remains largely unknown. Here, we have determined the complete cpDNA (131,183 bp) and mtDNA (56,574 bp) sequences of the charophyte Chaetosphaeridium globosum (Coleochaetales). At the levels of gene content (124 genes), intron composition (18 introns), and gene order, Chaetosphaeridium cpDNA is remarkably similar to land-plant cpDNAs, implying that most of the features characteristic of land-plant lineages were gained during the evolution of charophytes. Although the gene content of Chaetosphaeridium mtDNA (67 genes) closely resembles that of the bryophyte Marchantia polymorpha (69 genes), this charophyte mtDNA differs substantially from its land-plant relatives at the levels of size, intron composition (11 introns), and gene order. Our finding that it shares only one intron with its land-plant counterparts supports the idea that the vast majority of mitochondrial introns in land plants appeared after the emergence of these organisms. Our results also suggest that the events accounting for the spacious intergenic spacers found in land-plant mtDNAs took place late during the evolution of charophytes or coincided with the transition from charophytes to land plants.
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Affiliation(s)
- Monique Turmel
- Canadian Institute for Advanced Research, Program in Evolutionary Biology, and Département de Biochimie et de Microbiologie, Université Laval, Québec, QC, Canada G1K 7P4.
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19
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Brinkman FSL, Blanchard JL, Cherkasov A, Av-Gay Y, Brunham RC, Fernandez RC, Finlay BB, Otto SP, Ouellette BFF, Keeling PJ, Rose AM, Hancock REW, Jones SJM, Greberg H. Evidence that plant-like genes in Chlamydia species reflect an ancestral relationship between Chlamydiaceae, cyanobacteria, and the chloroplast. Genome Res 2002; 12:1159-67. [PMID: 12176923 PMCID: PMC186644 DOI: 10.1101/gr.341802] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
An unusually high proportion of proteins encoded in Chlamydia genomes are most similar to plant proteins, leading to proposals that a Chlamydia ancestor obtained genes from a plant or plant-like host organism by horizontal gene transfer. However, during an analysis of bacterial-eukaryotic protein similarities, we found that the vast majority of plant-like sequences in Chlamydia are most similar to plant proteins that are targeted to the chloroplast, an organelle derived from a cyanobacterium. We present further evidence suggesting that plant-like genes in Chlamydia, and other Chlamydiaceae, are likely a reflection of an unappreciated evolutionary relationship between the Chlamydiaceae and the cyanobacteria-chloroplast lineage. Further analyses of bacterial and eukaryotic genomes indicates the importance of evaluating organellar ancestry of eukaryotic proteins when identifying bacteria-eukaryote homologs or horizontal gene transfer and supports the proposal that Chlamydiaceae, which are obligate intracellular bacterial pathogens of animals, are not likely exchanging DNA with their hosts.
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Affiliation(s)
- Fiona S L Brinkman
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada, V5A 1S6.
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20
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Choi KR, Roh K, Kim J, Sim W. Genomic cloning and characterization of mitochondrial elongation factor Tu (EF-Tu) gene (tufM) from maize (Zea mays L.). Gene 2000; 257:233-42. [PMID: 11080589 DOI: 10.1016/s0378-1119(00)00404-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We have cloned and characterized a mitochondrial elongation factor Tu (EF-Tu) gene (tufM) in maize (Zea mays L.). This maize tufM gene encoded a polypeptide of 452 amino acid residues, consisting of a putative transit peptide of 55 residues and a mature EF-Tu of 397 residues. The coding region was composed of 12 exons and 11 introns that ranged from 76 to 1673bp in length. The deduced amino acid sequence showed 85.9% and 61.2% identity with Arabidopsis mitochondrial EF-Tu and Arabidopsis chloroplast EF-Tu sequence respectively. The transcription initiation site was determined to be 165bp upstream of the AUG initiation codon by primer extension analysis. Southern blot analysis revealed that the cloned EF-Tu gene was encoded by the members of small gene family in maize. Although this gene does not resemble the Arabidopsis nuclear tufA gene, which encodes the plastid EF-Tu, and does not contain sequence elements found in all cyanobacterial and plastid tufA genes, the predicted amino acid sequence includes an N-terminal extension that resembles a mitochondrial targeting sequence, and shares three unique sequence elements with mitochondrial EF-Tu's from Arabidopsis thaliana, Saccharomyces cerevisiae, and Homo sapiens. Therefore, we concluded that this gene encodes the maize mitochondrial EF-Tu.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Blotting, Southern
- Cloning, Molecular
- DNA, Plant/chemistry
- DNA, Plant/genetics
- DNA, Plant/isolation & purification
- Genes, Plant/genetics
- Mitochondria/chemistry
- Molecular Sequence Data
- Peptide Elongation Factor Tu/genetics
- Phylogeny
- Promoter Regions, Genetic
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Transcription, Genetic
- Zea mays/genetics
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Affiliation(s)
- K R Choi
- Department of Biology, Korea University, 136-701, Seoul, South Korea
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21
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Abstract
An extrachromosomal genome of between 27 and 35 kb has been described in several apicomplexan parasites including Plasmodium falciparum and Toxoplasma gondii. Examination of sequence data proved the genomes to be a remnant plastid genome, from which all genes encoding photosynthetic functions had been lost. Localisation studies had shown that the genome was located within a multi-walled organelle, anterior to the nucleus. This organelle had been previously described in ultrastructural studies of several genera of apicomplexa, but no function had been attributed to it. This invited review describes the evolution of knowledge on the apicomplexan plastid, then discusses current research findings on the likely role of the plastid in the Apicomplexa. How the plastid may be used to effect better drug treatments for apicomplexan diseases, and its potential as a marker for investigating phylogenetic relationships among the Apicomplexa, are discussed.
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Affiliation(s)
- M T Gleeson
- Department of Cell and Molecular Biology, Faculty of Science, University of Technology, Westbourne Street, Gore Hill NSW 2065, Sydney, Australia.
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22
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Blanchard JL, Hicks JS. The non-photosynthetic plastid in malarial parasites and other apicomplexans is derived from outside the green plastid lineage. J Eukaryot Microbiol 1999; 46:367-75. [PMID: 10461383 DOI: 10.1111/j.1550-7408.1999.tb04615.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The discovery of a non-photosynthetic plastid genome in Plasmodium falciparum and other apicomplexans has provided a new drug target, but the evolutionary origin of the plastid has been muddled by the lack of characters, that typically define major plastid lineages. To clarify the ancestry of the plastid, we undertook a comprehensive analysis of all genomic characters shared by completely sequenced plastid genomes. Cladistic analysis of the pattern of plastid gene loss and gene rearrangements suggests that the apicomplexan plastid is derived from an ancestor outside of the green plastid lineage. Phylogenetic analysis of primary sequence data (DNA and amino acid characters) produces results that are generally independent of the analytical method, but similar genes (i.e., rpoB and rpoC) give similar topologies. The conflicting phylogenies in primary sequence data sets make it difficult to determine the the exact origin of the apicomplexan plastid and the apparent artifactual association of apicomplexan and euglenoid sequences suggests that DNA sequence data may be an inappropriate set of characters to address this phylogenetic question. At present we cannot reject our null hypothesis that the apicomplexan plastid is derived from a shared common ancestor between apicomplexans and dinoflagellates. During the analysis, we noticed that the Plasmodium tRNA-Met is probably tRNA-fMet and the tRNA-fMet is probably tRNA-Ile. We suggest that P. falciparum has lost the elongator type tRNA-Met and that similar to metazoan mitochondria there is only one species of methionine tRNA. In P. falciparum, this has been accomplished by recruiting the fMet-type tRNA to dually function in initiation and elongation. The tRNA-Ile has an unusual stem-loop in the variable region. The insertion in this region appears to have occurred after the primary origin of the plastid and further supports the monophyletic ancestory of plastids.
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Affiliation(s)
- J L Blanchard
- Biology Department, University of Oregon, Eugene 97403, USA.
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23
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Qiu YL, Palmer JD. Phylogeny of early land plants: insights from genes and genomes. TRENDS IN PLANT SCIENCE 1999; 4:26-30. [PMID: 10234267 DOI: 10.1016/s1360-1385(98)01361-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
A large body of evidence from molecular systematic studies has confirmed the charophytic origin of land plants, and clarified monophyly of many lineages in charophytes and land plants. These studies have also identified liverworts as the earliest land plants, and the lycopods as the extant sister group to all other vascular plants. Two traditionally defined groups-bryophytes and pteridophytes-are now recognized as early grades of land plant evolution. However, several problems that complicate the use of sequence data in reconstructing plant phylogeny have become apparent; reconstruction of an accurate land plant phylogeny will require analysis of sequences of multiple genes and genomic structural characters of all three genomes.
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Affiliation(s)
- YL Qiu
- Institute of Systematic Botany, University of Zürich, Zollikerstrasse 107, Zurich, Switzerland
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24
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Yoshinaga K, Kakehi T, Shima Y, Iinuma H, Masuzawa T, Ueno M. Extensive RNA editing and possible double-stranded structures determining editing sites in the atpB transcripts of hornwort chloroplasts. Nucleic Acids Res 1997; 25:4830-4. [PMID: 9365264 PMCID: PMC147111 DOI: 10.1093/nar/25.23.4830] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Three nonsense codons and an unusual initiation codon were located within the putative coding region of the atpB gene of chloroplast DNA of the hornwort Anthoceros formosae. Nucleotide sequencing of cDNA prepared from transcripts revealed extensive RNA editing. The unusual initiation codon ACG was changed to AUG and three nonsense codons were converted into sense codons. In total 15 C residues of the genomic DNA were replaced by U residues in the mRNA sequences, while 14 U residues were replaced by C residues. This is the highest number of editing events for a chloroplast mRNA reported so far. Partial editing was also shown in a cDNA clone where 23 sites were edited but six sites remained unedited, representing the existence of premature mRNA. The expected two-dimensional structure of the mRNA shows the existence of a sequence complementary to every editing site, which can produce continuous base pairing longer than 5 bp, suggesting that mispairing in the double strand is the site determinant for RNA editing in Anthoceros chloroplasts. Comparison of the cDNA sequence with other chloroplast genes suggests that the mechanism arose in the first land plants and has been reduced during evolution.
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Affiliation(s)
- K Yoshinaga
- Faculty of Science, Shizuoka University, Shizuoka 422, Japan.
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25
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Boudreau E, Takahashi Y, Lemieux C, Turmel M, Rochaix JD. The chloroplast ycf3 and ycf4 open reading frames of Chlamydomonas reinhardtii are required for the accumulation of the photosystem I complex. EMBO J 1997; 16:6095-104. [PMID: 9321389 PMCID: PMC1326293 DOI: 10.1093/emboj/16.20.6095] [Citation(s) in RCA: 194] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The chloroplast genes ycf3 and ycf4 from the green alga Chlamydomonas reinhardtii have been characterized. The deduced amino acid sequences of Ycf4 (197 residues) and Ycf3 (172 residues) display 41-52% and 64-78% sequence identity, respectively, with their homologues from algae, land plants and cyanobacteria. In C. reinhardtii, ycf4 and ycf3 are co-transcribed as members of the rps9-ycf4-ycf3-rps18 polycistronic transcriptional unit into RNAs of 8.0 kb and 3.0 kb corresponding to the entire unit and to rps9-ycf4-ycf3, respectively. Using biolistic transformation, ycf4 and ycf3 were disrupted with a chloroplast selectable marker cassette. Transformants lacking ycf4 or ycf3 were unable to grow photoautotrophically and were deficient in photosystem I activity. Western blot analysis showed that the photosystem I (PSI) complex does not accumulate stably in thylakoid membranes of these transformants. Ycf4 and Ycf3 were localized on thylakoid membranes but not stably associated with the PSI complex and accumulated to wild-type levels in mutants lacking PSI. RNA blot hybridizations showed that transcripts of psaA, psaB and psaC accumulate normally in these mutants and use of chimeric reporter genes revealed that Ycf3 is not required for initiation of translation of psaA and psaB mRNA. Our results indicate that Ycf3 and Ycf4 are required for stable accumulation of the PSI complex.
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Affiliation(s)
- E Boudreau
- Departments of Molecular Biology and Plant Biology, University of Geneva, 30 quai Ernest-Ansermet, CH-1211, Geneve 4, Switzerland
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26
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Nickrent DL, Ouyang Y, Duff RJ, dePamphilis CW. Do nonasterid holoparasitic flowering plants have plastid genomes? PLANT MOLECULAR BIOLOGY 1997; 34:717-29. [PMID: 9278163 DOI: 10.1023/a:1005860632601] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Past work involving the plastid genome (plastome) of holoparasitic plants has been confined to Scrophulariaceae (or Orobanchaceae) which have truncated plastomes owing to loss of photosynthetic and other genes. Nonasterid holoparasites from Balanophoraceae (Corynaea), Hydnoraceae (Hydnora) and Cytinaceae (Cytinus) were tested for the presence of plastid genes and a plastome. Using PCR, plastid 16S rDNA was successfully amplified and sequenced from the above three holoparasites. The sequence of Cytinus showed 121 single base substitutions relative to Nicotiana (8% of the molecule) whereas higher sequence divergence was observed in Hydnora and Corynaea (287 and 513 changes, respectively). Secondary structural models for these 16S rRNAs show that most changes are compensatory, thus suggesting they are functional. Probes constructed for 16S rDNA and for four plastid-encoded ribosomal protein genes (rps2, rps4, rps7 and rpl 16) were used in Southern blots of digested genomic DNA from the three holoparasites. Positive hybridizations were obtained using each of the five probes only for Cytinus. For Smal digests, all plastid gene probes hybridized to a common fragment ca. 20 kb in length in this species. Taken together, these data provide preliminary evidence suggestive of the retention of highly diverged and truncated plastid genome in Cytinus. The greater sequence divergence for 16S rDNA and the negative hybridization results for Hydnora and Corynaea suggests two possibilities: the loss of typically conserved elements of their plastomes or the complete absence of a plastome.
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Affiliation(s)
- D L Nickrent
- Department of Plant Biology, Southern Illinois University, Carbondale 62901-6509, USA
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27
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Kuhlman P, Palmer JD. Isolation, expression, and evolution of the gene encoding mitochondrial elongation factor Tu in Arabidopsis thaliana. PLANT MOLECULAR BIOLOGY 1995; 29:1057-1070. [PMID: 8555448 DOI: 10.1007/bf00014977] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We have characterized a second nuclear gene (tufM) in Arabidopsis thaliana that encodes a eubacterial-like protein synthesis elongation factor Tu (EF-Tu). This gene does not closely resemble the previously described Arabidopsis nuclear tufA gene, which encodes the plastid EF-Tu, and does not contain sequence elements found in all cyanobacterial and plastid tufA genes. However, the predicted amino acid sequence includes an N-terminal extension which resembles an organellar targeting sequence and shares three unique sequence elements with mitochondrial EF-Tu's, from Saccharomyces cerevisiae and Homo sapiens, suggesting that this gene encodes the Arabidopsis mitochondrial EF-Tu. Consistent with this interpretation, the gene is expressed at a higher level in flowers than in leaves. Phylogenetic analysis confirms the mitochondrial character of the sequence and indicates that the human, yeast, and Arabidopsis tufM genes have undergone considerably more sequence divergence than their cytoplasmic counterparts, perhaps reflecting a cross-compartmental acceleration of gene evolution for components of the mitochondrial translation apparatus. As previously observed for tufA, the tufM gene is present in one copy in Arabidopsis but in several copies in other species of crucifers.
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Affiliation(s)
- P Kuhlman
- Department of Biology, Indiana University, Bloomington 47405, USA
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Cerutti H, Jagendorf A. Movement of DNA across the chloroplast envelope: Implications for the transfer of promiscuous DNA. PHOTOSYNTHESIS RESEARCH 1995; 46:329-337. [PMID: 24301600 DOI: 10.1007/bf00020448] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/1995] [Accepted: 05/02/1995] [Indexed: 06/02/2023]
Abstract
Little is known about the mechanistic basis for the movement of promiscuous nucleic acids across cell membranes. To address this problem we sought conditions that would permit the entry of plasmid DNA into isolated, intact pea chloroplasts. DNA uptake did not occur normally, but was induced by hypotonic treatments, by incubation with millimolar levels of Mg(2+), or by heat shock at 42 °C. These results are consistent with DNA movement being permitted by conditions that transiently alter the permeability of the chloroplast envelope. Plant cells are subject to osmotic tensions and/or conditions inducing polymorphic changes in the membranes, such as those used in the present study, under several environmental stresses. In an evolutionary time frame, these phenomena may provide a mechanism for the transfer of promiscuous nucleic acids between organelles.
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Affiliation(s)
- H Cerutti
- Plant Biology Section, Plant Science Building, Cornell University, 14853, Ithaca, NY, USA
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29
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Kranz HD, Miks D, Siegler ML, Capesius I, Sensen CW, Huss VA. The origin of land plants: phylogenetic relationships among charophytes, bryophytes, and vascular plants inferred from complete small-subunit ribosomal RNA gene sequences. J Mol Evol 1995; 41:74-84. [PMID: 7608991 DOI: 10.1007/bf00174043] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Complete nuclear-encoded small-subunit 18S rRNA (= SSU rRNA) gene sequences were determined for the prasinophyte green alga Mantoniella squamata; the charophycean green algae Chara foetida, Coleochaete scutata, Klebsormidium flaccidum, and Mougeotia scalaris; the bryophytes Marchantia polymorpha, Fossombronia pusilla, and Funaria hygrometrica; and the lycopod Selaginella galleottii to get a better insight into the sequential evolution from green algae to land plants. The sequences were aligned with several previously published SSU rRNA sequences from chlorophytic and charophytic algae as well as from land plants to infer the evolutionary relationships for major evolutionary lineages within the Chlorobionta by distance matrix, maximum parsimony, and maximum likelihood analyses. Phylogenetic trees created by the different methods consistently placed the Charophyceae on the branch leading to the land plants. The Charophyceae were shown to be polyphyletic with the Charales ("charalean" algae) diverging earlier than the Coleochaetales, Klebsormidiales, Chlorokybales, and Zygnematales ("charophycean" algae) which branch from a point closer to the land plants in most analyses. Maximum parsimony and maximum likelihood analyses imply a successive evolution from "charophycean" algae, particularly Coleochaetales, to bryophytes, lycopods, and seed plants. In contrast, distance matrix methods group the bryophytes together with the "charophycean" algae, suggesting a separate evolution of these organisms compared with the club moss and the seed plants.
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Affiliation(s)
- H D Kranz
- Institut für Botanik und Pharmazeutische Biologie der Universität, Erlangen, Germany
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30
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Weber S, Lottspeich F, Köhl J. An epitope of elongation factor Tu is widely distributed within the bacterial and archaeal domains. J Bacteriol 1995; 177:11-9. [PMID: 7528200 PMCID: PMC176550 DOI: 10.1128/jb.177.1.11-19.1995] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
A monoclonal antibody (MAb), MAb 900, which detects a 43-kDa protein present on Escherichia coli was found. Subsequently, more than 90 organisms, belonging to either the bacterial, archaeal, or eucaryal domain, were tested for reactivity to this MAb. Of the bacterial and archaeal domains, almost all species proved to be positive, whereas all organisms from the eucaryal domain gave negative results. The 43-kDa protein was purified by affinity chromatography and subsequently analyzed by microsequencing methods. Two peptide sequences which showed a high degree of homology (> 99%) to the prokaryotic elongation factor Tu (EF-Tu) were obtained. Western blot (immunoblot) analysis using both purified EF-Tu and EF-Tu domains confirmed that the unknown protein was EF-Tu. The panbacterial distribution of EF-Tu, which is present in large amounts in every prokaryotic cell, renders this protein a good candidate for a diagnostic approach. In consequence, we have used the anti-EF-Tu MAb 900 to design both a dot blot assay and an enzyme-linked immunosorbent assay. From either blood culture, urine, or gall-bladder fluid, bacterial contamination could be detected. The sensitivity of these tests is currently 10(4) bacteria per ml.
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Affiliation(s)
- S Weber
- Institut für Medizinische Mikrobiologie, Medizinische Hochschule Hannover, Germany
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31
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Abstract
Consistent with their postulated origin from endosymbiotic cyanobacteria, chloroplasts of plants and algae have ribosomes whose component RNAs and proteins are strikingly similar to those of eubacteria. Comparison of the secondary structures of 16S rRNAs of chloroplasts and bacteria has been particularly useful in identifying highly conserved regions likely to have essential functions. Comparative analysis of ribosomal protein sequences may likewise prove valuable in determining their roles in protein synthesis. This review is concerned primarily with the RNAs and proteins that constitute the chloroplast ribosome, the genes that encode these components, and their expression. It begins with an overview of chloroplast genome structure in land plants and algae and then presents a brief comparison of chloroplast and prokaryotic protein-synthesizing systems and a more detailed analysis of chloroplast rRNAs and ribosomal proteins. A description of the synthesis and assembly of chloroplast ribosomes follows. The review concludes with discussion of whether chloroplast protein synthesis is essential for cell survival.
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Affiliation(s)
- E H Harris
- DCMB Group, Department of Botany, Duke University, Durham, North Carolina 27708-1000
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32
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Abstract
Consistent with their postulated origin from endosymbiotic cyanobacteria, chloroplasts of plants and algae have ribosomes whose component RNAs and proteins are strikingly similar to those of eubacteria. Comparison of the secondary structures of 16S rRNAs of chloroplasts and bacteria has been particularly useful in identifying highly conserved regions likely to have essential functions. Comparative analysis of ribosomal protein sequences may likewise prove valuable in determining their roles in protein synthesis. This review is concerned primarily with the RNAs and proteins that constitute the chloroplast ribosome, the genes that encode these components, and their expression. It begins with an overview of chloroplast genome structure in land plants and algae and then presents a brief comparison of chloroplast and prokaryotic protein-synthesizing systems and a more detailed analysis of chloroplast rRNAs and ribosomal proteins. A description of the synthesis and assembly of chloroplast ribosomes follows. The review concludes with discussion of whether chloroplast protein synthesis is essential for cell survival.
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Affiliation(s)
- E H Harris
- DCMB Group, Department of Botany, Duke University, Durham, North Carolina 27708-1000
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33
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Welcsh PL, Johnson DR, Zhang Y, Breitenberger CA. Synechocystis sp. PCC6803 fusB gene, located outside of the str operon, encodes a polypeptide related to protein synthesis factor EF-G. PLANT MOLECULAR BIOLOGY 1994; 25:735-738. [PMID: 8061323 DOI: 10.1007/bf00029610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Synechocystis sp. PCC6803, a cyanobacterium, possesses an unusual gene (fusB) which encodes a protein with strong homology to protein synthesis elongation factor G (EF-G), although it is not linked to the classical str operon. The fusB gene is redundant, since a Synechocystis gene similar to str operon-encoded fusA genes of other bacteria is also present (based on PCR and hybridization results). There is no evidence for the presence of a fusB homologue in other bacteria. The Synechocystis fusB gene encodes unusual amino acids at some positions that are highly conserved in fusA genes of other prokaryotes.
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Affiliation(s)
- P L Welcsh
- Department of Molecular Genetics, Ohio State Biotechnology Center, Ohio State University, Columbus 43210
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34
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Downie SR, Katz-Downie DS, Wolfe KH, Calie PJ, Palmer JD. Structure and evolution of the largest chloroplast gene (ORF2280): internal plasticity and multiple gene loss during angiosperm evolution. Curr Genet 1994; 25:367-78. [PMID: 8082181 DOI: 10.1007/bf00351492] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have determined the nucleotide sequence of the Pelargonium x hortorum ORF2280 homolog, the largest gene in the plastid genome of most land plants, and compared it to published homologs from Nicotiana tabacum, Epifagus virginiana, Spinacia oleracea, and Marchantia polymorpha. Multiple alignment of protein sequences requires an extraordinary number of gaps, indicating a very high frequency of insertion/deletion events during the evolution of the protein; however, the overall predicted size of the protein varies relatively little among the five species. At 2,109 codons, the Pelargonium gene is smaller than other land plant ORF2280 homologs and exhibits a rate of nucleotide substitution several times higher relative to Nicotiana, Epifagus, and Spinacia. Southern-blot and restriction-mapping studies were carried out to uncover length variation in ORF2280 homologs from 279 species (representing 111 families) of angiosperms. In many independent angiosperm lineages, this gene has sustained deletions ranging in size from 200 bp to almost 6 kb. Based on the severity of deletions, we postulate that the chloroplast homolog of ORF2280 has become nonfunctional in at least four independent lineages of angiosperms.
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Affiliation(s)
- S R Downie
- Department of Biology, Indiana University, Bloomington 47405
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35
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Reynolds AE, Chesnick JM, Woolford J, Cattolico RA. Chloroplast encoded thioredoxin genes in the red algae Porphyra yezoensis and Griffithsia pacifica: evolutionary implications. PLANT MOLECULAR BIOLOGY 1994; 25:13-21. [PMID: 8003693 DOI: 10.1007/bf00024194] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A gene encoding a thioredoxin protein was identified in the chloroplast genome of the rhodophyte Porphyra yezoensis. The P. yezoensis trxA gene contains 324 bp and is transcribed into a 0.7 kb messenger RNA. Analysis of the transcription start site demonstrates that canonical chloroplast -10 and -35 sequences are not present. The deduced amino acid sequence of the thioredoxin gene from the red algae has the greatest similarity to type m thioredoxins, providing strong support for the hypothesis that type m thioredoxins in photosynthetic eukaryotes originated from an engulfed bacterial endosymbiont. Hybridization analysis of nuclear and chloroplast DNAs from several members of the phyla Chromophyta and Rhodophyta using P. yezoensis DNA as a probe demonstrated strong hybridization to the chloroplast and nuclear genomes of Griffithsia pacifica and a weak cross-hybridization to the chromophyte P. foliaceum. The G. pacifica chloroplast gene has a 66% identity with the P. yezoensis DNA, contains conserved active site amino acid residues, but lacks a methionine start codon.
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Affiliation(s)
- A E Reynolds
- Botany Department, University of Washington 98195
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36
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Kanevski I, Maliga P. Relocation of the plastid rbcL gene to the nucleus yields functional ribulose-1,5-bisphosphate carboxylase in tobacco chloroplasts. Proc Natl Acad Sci U S A 1994; 91:1969-73. [PMID: 8127916 PMCID: PMC43286 DOI: 10.1073/pnas.91.5.1969] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The conserved plastid localization of rbcL suggests that biosynthesis of the large subunit of ribulose-1,5-bisphosphate carboxylase [Rubisco; 3-phospho-D-glycerate carboxy-lyase (dimerizing), EC 4.1.1.39] in chloroplasts is required to obtain functional enzyme. To examine the validity of this hypothesis, we relocated the plastid rbcL gene to the nucleus. First, we deleted the rbcL gene from the tobacco plastid genome by targeted insertion of a selectable aadA gene encoding spectinomycin resistance. The rbcL coding region was then inserted into an expression cassette and introduced into the nuclear genome of these plants by Agrobacterium-mediated transformation. We report that the nuclear rbcL functionally complements the defective plastids when the Rubisco large subunit is targeted to chloroplasts by a transit peptide. Therefore, the evolutionary process that relocates functional plastid genes to the nucleus has not yet occurred in the case of the rbcL gene. Targeted deletion of plastid genes, combined with their allotopic expression, will provide opportunities for studying the function of plastid enzyme complexes.
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Affiliation(s)
- I Kanevski
- Waksman Institute, Rutgers, State University of New Jersey, Piscataway 08855-0759
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37
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Sugita M, Murayama Y, Sugiura M. Structure and differential expression of two distinct genes encoding the chloroplast elongation factor Tu in tobacco. Curr Genet 1994; 25:164-8. [PMID: 8087886 DOI: 10.1007/bf00309543] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have isolated two nuclear genes, tufA and tufB, encoding chloroplast EF-Tu from a tobacco (Nicotiana sylvestris) genomic library. The tufA gene encodes a polypeptide of 478 amino-acid residues, consisting of a putative transit peptide of 70 residues and a mature EF-TuA of 408 residues. The tufB gene codes for a precursor proteins of 485 residues, containing a transit peptide of 77 residues and a mature EF-TuB of 408 residues. No introns were found in either gene. The sequence similarity within the coding regions of the two genes is 84.3% for nucleotides and 89.7% for amino acids. Multiple 5' ends of transcripts were observed for both tuf genes. Northern analysis revealed that the EF-Tu mRNA accumulated at least 30-fold more in leaf than in root tissue. Ribonuclease protection assays using gene-specific probes showed that the level of tufB mRNA is three-fold higher than that of tufA mRNA in leaves but in roots the tufB mRNA levels is less than half that of tufA mRNA. The relative amount of tufB mRNA is 30-fold higher in leaves than in roots whereas tufA messages are only five-fold higher in leaves. These data suggest that expression of both tuf genes is differentially regulated according to tissue and plastid type.
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Affiliation(s)
- M Sugita
- Center for Gene Research, Nagoya University, Japan
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38
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Abstract
The first three decades of the subdiscipline of biology known as "molecular evolution" have generated large amounts of new information that illuminate the nature of evolutionary pattern and process. Major progress has been made in identifying primary sequence variation in genes and their protein products, initially from biochemically tractable systems (from large or culturable organisms and from highly-reiterated genes or highly-expressed gene products). In the 1980s, these techniques that had been limited to specialists, to relatively few representatives of the diversity of life, and to a small number of those organisms' genes, were extended through advances in molecular genetics and biochemistry, resulting in an explosion of molecular information and a proliferation of molecular trees. Studies of variation in molecular characters also were rarely linked with studies of anatomical, behavioral or ecological diversity. More sophisticated molecular genetic and biochemical techniques, currently being applied to long-standing questions in cell and developmental biology in model systems, should be applicable to more diverse lineages in the next decade. Molecular trees produced from one or more "housekeeping genes" can identify key lineages (species, populations, genomes or gene families) which, by comparison to model systems, may illuminate important aspects of higher level variability. Thus, the next phase of research in the field of molecular evolution should see greater linkage between studies of simple molecular and more complex developmental characters, and increased functional testing of genes and gene products in an evolutionary context. This review highlights some comparative experimental approaches that I believe will be most effective in extending our understanding of molecular evolution and better linking the field to other areas of science in the next few years.
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Affiliation(s)
- E A Zimmer
- Laboratory of Molecular Systematics, Smithsonian Institution, Washington, DC 20560
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39
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Löffelhardt W, Bohnert HJ. Structure and function of the cyanelle genome. INTERNATIONAL REVIEW OF CYTOLOGY 1994; 151:29-65. [PMID: 7516928 DOI: 10.1016/s0074-7696(08)62630-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- W Löffelhardt
- Institut für Biochemie und Molekulare Zellbiologie, Universität Wien, Austria
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40
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Martin W, Brinkmann H, Savonna C, Cerff R. Evidence for a chimeric nature of nuclear genomes: eubacterial origin of eukaryotic glyceraldehyde-3-phosphate dehydrogenase genes. Proc Natl Acad Sci U S A 1993; 90:8692-6. [PMID: 8378350 PMCID: PMC47424 DOI: 10.1073/pnas.90.18.8692] [Citation(s) in RCA: 136] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Higher plants process two distinct, nuclear gene-encoded glyceraldehyde-3-phosphate dehydrogenase (GAPDH) proteins, a Calvin-cycle enzyme active within chloroplasts and a glycolytic enzyme active within the cytosol. The gene for the chloroplast enzyme was previously suggested to be of endosymbiotic origin. Since the ancestors of plastids were related to cyanobacteria, we have studied GAPDH genes in the cyanobacterium Anabaena variabilis. Our results confirm that the nuclear gene for higher plant chloroplast GAPDH indeed derives from the genome of a cyanobacterium-like endosymbiont. But two additional GAPDH genes were found in the Anabaena genome and, surprisingly, one of these sequences is very similar to nuclear genes encoding the GAPDH enzyme of glycolysis in plants, animals, and fungi. Evidence that the eukaryotic nuclear genes for glycolytic GAPDH, as well as the Calvin-cycle genes, are of eubacterial origin suggests that eukaryotic genomes are more highly chimeric than previously assumed.
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Affiliation(s)
- W Martin
- Institut für Genetik, Technische Universität Braunschweig, Germany
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41
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Murayama Y, Matsubayashi T, Sugita M, Sugiura M. Purification of chloroplast elongation factor Tu and cDNA analysis in tobacco: the existence of two chloroplast elongation factor Tu species. PLANT MOLECULAR BIOLOGY 1993; 22:767-74. [PMID: 8358028 DOI: 10.1007/bf00027363] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We have purified a chloroplast elongation factor Tu (EF-Tu) from tobacco (Nicotiana tabacum) and determined its N-terminal amino acid sequence. Two distinct cDNAs encoding EF-Tu were isolated from a leaf cDNA library of N. sylvestris (the female progenitor of N. tabacum) using an oligonucleotide probe based on the EF-Tu protein sequence. The cDNA sequence and genomic Southern analyses revealed that tobacco chloroplast EF-Tu is encoded by two distinct genes in the nuclear genome of N. sylvestris. We designated the corresponding gene products EF-Tu A and B. The mature polypeptides of EF-Tu A and B are 408 amino acids long and share 95.3% amino acid identity. They show 75-78% amino acid identity with cyanobacterial and chloroplast-encoded EF-Tu species.
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Affiliation(s)
- Y Murayama
- Center for Gene Research, Nagoya University, Japan
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42
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Reith M, Munholland J. A High-Resolution Gene Map of the Chloroplast Genome of the Red Alga Porphyra purpurea. THE PLANT CELL 1993; 5:465-475. [PMID: 12271072 PMCID: PMC160285 DOI: 10.1105/tpc.5.4.465] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Extensive DNA sequencing of the chloroplast genome of the red alga Porphyra purpurea has resulted in the detection of more than 125 genes. Fifty-eight (approximately 46%) of these genes are not found on the chloroplast genomes of land plants. These include genes encoding 17 photosynthetic proteins, three tRNAs, and nine ribosomal proteins. In addition, nine genes encoding proteins related to biosynthetic functions, six genes encoding proteins involved in gene expression, and at least five genes encoding miscellaneous proteins are among those not known to be located on land plant chloroplast genomes. The increased coding capacity of the P. purpurea chloroplast genome, along with other characteristics such as the absence of introns and the conservation of ancestral operons, demonstrate the primitive nature of the P. purpurea chloroplast genome. In addition, evidence for a monophyletic origin of chloroplasts is suggested by the identification of two groups of genes that are clustered in chloroplast genomes but not in cyanobacteria.
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Affiliation(s)
- M. Reith
- National Research Council of Canada, Institute for Marine Biosciences, 1411 Oxford Street, Halifax, Nova Scotia, B3H 3Z1 Canada
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43
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Reith M, Munholland J. Two amino-acid biosynthetic genes are encoded on the plastid genome of the red alga Porphyra umbilicalis. Curr Genet 1993; 23:59-65. [PMID: 8381336 DOI: 10.1007/bf00336751] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
To isolate the gene encoding the amino-acid biosynthetic enzyme acetolactate synthase (ALS) from the red alga Porphyra umbilicalis, PCR experiments were carried out using P. umbilicalis DNA as the template and degenerate oligonucleotides representing conserved regions of ALS amino-acid sequences. Interestingly, the PCR product (0.9 kb) hybridized exclusively to the plastid DNA of this red alga. DNA sequencing of two contiguous EcoRI plastid DNA clones revealed a 590 amino-acid open reading frame with 55 to 61% identity to cyanobacterial ALS sequences. A second gene (argB) encoding another amino-acid biosynthetic enzyme, N-acetylglutamate kinase, was identified upstream of, and on the opposite strand to the gene encoding ALS (ilvB). This is the first molecular characterization of a gene for an arginine biosynthetic enzyme from any plant. In addition, two tRNA genes, trnT(GGU) and trnY(GUA), were detected downstream from ilvB while four tRNA genes, trnfM(CAU), trnA(GGC), trnA(GGC), trnS(-GCU) and trnD(GUC), were found downstream from argB. trnA(GGC) is not found in the chloroplast genomes of land plants.
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Affiliation(s)
- M Reith
- National Research Council of Canada, Institute for Marine Biosciences, Halifax, Nova Scotia
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44
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Smith MW, Doolittle RF. A comparison of evolutionary rates of the two major kinds of superoxide dismutase. J Mol Evol 1992; 34:175-84. [PMID: 1556751 DOI: 10.1007/bf00182394] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Phylogenetic trees were constructed for 25 Cu-Zn superoxide dismutases and 31 Mn/Fe superoxide dismutases. The latter set includes seven new sequences that we determined in an effort to make the two phylogenies equally representative. We analyzed all pairwise differences in each set in an attempt to estimate rates of change. As reported by others, the Cu-Zn enzyme has experienced significant changes in its evolutionary rate. In contrast, the clock for the Mn/Fe enzyme is ticking quite regularly. The comparison of these two independently evolved superoxide dismutases that catalyze the same reaction and occur together throughout much of the biological world suggests that adaptation to environmental stress is not the basis for the erratic rate of change observed in the Cu-Zn enzyme.
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Affiliation(s)
- M W Smith
- Center for Molecular Genetics, University of California, San Diego, La Jolla 92093-0634
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45
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Lockhart PJ, Howe CJ, Bryant DA, Beanland TJ, Larkum AW. Substitutional bias confounds inference of cyanelle origins from sequence data. J Mol Evol 1992; 34:153-62. [PMID: 1556750 DOI: 10.1007/bf00182392] [Citation(s) in RCA: 120] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Available molecular and biochemical data offer conflicting evidence for the origin of the cyanelle of Cyanophora paradoxa. We show that the similarity of cyanelle and green chloroplast sequences is probably a result of these two lineages independently developing the same pattern of directional nucleotide change (substitutional bias). This finding suggests caution should be exercised in the interpretation of nucleotide sequence analyses that appear to favor the view of a common endosymbiont for the cyanelle and chlorophyll-b-containing chloroplasts. The data and approaches needed to resolve the issue of cyanelle origins are discussed. Our findings also have general implications for phylogenetic inference under conditions where the base compositions (compositional bias) of the sequences analyzed differ.
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Affiliation(s)
- P J Lockhart
- Department of Biological Sciences, University of Sydney, NSW, Australia
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46
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Affiliation(s)
- M W Gray
- Department of Biochemistry, Dalhousie University, Halifax, Nova Scotia, Canada
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47
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Wang SL, Liu XQ. The plastid genome of Cryptomonas phi encodes an hsp70-like protein, a histone-like protein, and an acyl carrier protein. Proc Natl Acad Sci U S A 1991; 88:10783-7. [PMID: 1961745 PMCID: PMC53015 DOI: 10.1073/pnas.88.23.10783] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The plastid genome of Cryptomonas phi, a cryptomonad alga, contains three genes that have not previously been found in any organellar genome. Each of these genes encodes a functional class of organellar gene product not previously reported. The first gene, dnaK, encodes a polypeptide of the hsp70 heat shock protein family. The predicted amino acid sequence of the DnaK protein is 54% identical to that of the Escherichia coli hsp70 protein (DnaK), 50-53% identical to that of two nucleus-encoded mitochondrial hsp70 proteins, and 43-46% identical to that of several eukaryotic cytoplasmic members of the hsp70 protein family. The second gene, hlpA, encodes a polypeptide resembling bacterial histone-like proteins. The predicted amino acid sequence of the HlpA protein is 25-53% identical to that of several bacterial histone-like proteins, and the identity increases to 39-76% over a conserved region corresponding to the long arm that binds DNA. The third gene, acpA, encodes an acyl carrier protein, which is a key cofactor in the synthesis and metabolism of fatty acids. Its predicted amino acid sequence is 36-59% identical to that of eubacterial and plant chloroplast (nucleus-encoded) acyl carrier proteins.
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Affiliation(s)
- S L Wang
- Canadian Institute for Advanced Research, Department of Biochemistry, Dalhousie University, Halifax, NS
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48
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New nucleotide sequence data on the EMBL file server. Nucleic Acids Res 1990; 18:7201-7. [PMID: 2263510 PMCID: PMC332850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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