DOCSLIB.ORG

Identification and Isolation of Genetic Elements Conferring Increased

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Identification and Isolation of Genetic Elements Conferring Increased The Pennsylvania State University The Graduate School Intercollege Graduate Degree Program in Plant Physiology IDENTIFICATION AND ISOLATION OF GENETIC ELEMENTS CONFERRING INCREASED TOMATO FRUIT LYCOPENE CONTENT A Dissertation in Plant Physiology by Matthew Kinkade © 2010 Matthew Kinkade Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy August 2010 The dissertation of Matthew Kinkade was reviewed and approved* by the following: Majid R. Foolad Professor of Plant Genetics Dissertation Advisor and Chair of Committee David M. Braun Associate Professor of Biological Sciences University of Missouri-Columbia John E. Carlson Professor of Molecular Genetics David R. Huff Associate Professor of Turfgrass Breeding and Genetics Yinong Yang Associate Professor of Plant Pathology Teh-hui Kao Professor of Biochemistry and Molecular Biology Program Chair, Intercollege Graduate Degree Program in Plant Biology *Signatures on file at the Graduate School. ii ABSTRACT The cultivated tomato (Solanum lycopersicum L.) is a vegetable crop produced and consumed around the world, and is a model system for the study of carotenoid accumulation. The dominant carotenoid in tomato is trans-lycopene, a powerful antioxidant that has been postulated to confer health benefits to humans and is responsible for the red appearance of ripe tomato fruits. Increasing lycopene content in tomato fruits represents an opportunity to increase market value for tomato crops, elevate the nutritional content of tomato for consumers, and to increase scientific understanding of carotenogenesis in plants. However, very few tomato alleles that cause increased lycopene accumulation in ripe fruits and are immediately useful for breeding purposes have been described in the literature. Given that little genetic variation exists within the cultivated tomato germplasm, wild Solanum species provide a unique opportunity to transfer new alleles into the cultigen. Using a recombinant inbred line (RIL) population derived from a cross between S. lycopersicum NCEBR-1, an advanced fresh market tomato breeding line with moderate lycopene content, and S. pimpinellifolium LA2093, a wild accession with exceptionally high lycopene content, the genetic architecture underlying lycopene accumulation is described. Quantitative trait locus (QTL) mapping over several years using lycopene data obtained via colorimetry, spectrophotometry, and high-performance liquid chromatography assays reveals a highly-significant three-QTL model which explains ~45% of the phenotypic variation in the RIL population. Two of these QTL, located on chromosomes 7 (lyc7.1) and 12 (lyc12.1), explain most of the phenotypic variation. A marker-assisted backcross program was subsequently initiated to verify QTL effects and isolate the QTLs in a uniform genetic background. Genotypes harboring lyc12.1 contained approximately 72% more lycopene than the recurrent parent, NCEBR-1. Near-isogenic lines for lyc12.1 were produced, the QTL was fine mapped to a 1.5 Mb region of tomato genome sequence, and candidate genes underlying the QTL were identified for further study. Future experimentation outlined in this dissertation will elucidate the gene’s role in carotenogenesis. This work represents a major advance in the search for new genes that affect lycopene accumulation in tomato, and, due to the plant material utilized, lyc12.1 is immediately useful for tomato breeding purposes. iii TABLE OF CONTENTS LIST OF TABLES .................................................................................................................................... VI LIST OF FIGURES .................................................................................................................................VII ACKNOWLEDGMENTS......................................................................................................................... IX CHAPTER I. INTRODUCTION ..............................................................................................................1 A SHORT HISTORY OF TOMATO (SOLANUM LYCOPERSICUM LINNAEUS).........................................................1 CURRENT ECONOMICS OF TOMATO........................................................................................................................2 CAROTENOIDS AND HUMANS...................................................................................................................................2 CAROTENOID BIOSYNTHESIS AND REGULATION IN TOMATO............................................................................4 QUANTITATIVE GENETICS AND TOMATO ........................................................................................................... 12 PROCESSES FOR QTL DETECTION AND ISOLATION.......................................................................................... 15 QTL mapping........................................................................................................................................................ 15 NIL development................................................................................................................................................. 16 Fine mapping........................................................................................................................................................ 17 THE PROBLEM......................................................................................................................................................... 18 PREVIOUS FRUIT QUALITY RESEARCH AT PENN STATE UNIVERSITY .......................................................... 19 OVERVIEW OF EXPERIMENTS CONDUCTED IN THIS THESIS PROJECT .......................................................... 20 REFERENCES............................................................................................................................................................ 20 CHAPTER II. MAPPING OF QTLS CONTROLLING TOMATO LYCOPENE CONTENT FROM S. PIMPINELLIFOLIUM LA2093........................................................................................................ 28 A NOTE ON THIS CHAPTER ................................................................................................................................... 28 ABSTRACT ................................................................................................................................................................ 29 INTRODUCTION ....................................................................................................................................................... 30 MATERIALS AND METHODS.................................................................................................................................. 32 RESULTS ................................................................................................................................................................... 34 CIM analyses based on HPLC measurement ........................................................................................... 34 CIM analyses based on spectrophotometer measurement............................................................... 38 CIM analyses based on colorimeter data modeling............................................................................. 39 Heritability and correlations with other fruit Quality traits........................................................... 41 DISCUSSION.............................................................................................................................................................. 41 Comparison with previous QTL mapping studies................................................................................. 41 Segregation distortion ..................................................................................................................................... 43 Method of trait measurement....................................................................................................................... 44 Implications for tomato breeding and future experimentation .................................................... 45 ACKNOWLEDGMENTS............................................................................................................................................. 47 REFERENCES............................................................................................................................................................ 48 TABLES AND FIGURES ............................................................................................................................................ 53 CHAPTER III. VALIDATION AND ISOLATION OF HIGH­LYCOPENE QTL LYC12.1 VIA MARKER­ASSISTED SELECTION AND NIL DEVELOPMENT .................................................... 60 iv ABSTRACT ................................................................................................................................................................ 60 INTRODUCTION ....................................................................................................................................................... 61 MATERIALS AND METHODS.................................................................................................................................. 63 RESULTS AND DISCUSSION.................................................................................................................................... 66 37BC2 lycopene analysis ................................................................................................................................
Load more

Recommended publications
  • Daylily Genetics Part 3 Variegated Or Broken Flower Colors: Jumping Genes?
    ~1~ Summer 11 DJ Science ‘Pink Stripes’ (Derrow, 2006) ‘Peppermint Ice’ (Lovell, 2004) — Photo courtesy of the hybridizer The unabridged version — Kyle Billadeau photo Daylily Genetics Part 3 Variegated or broken flower colors: Jumping genes? clonal and non-clonal patterns may be genet- some compound which affects pigmentation ic involving a change in DNA sequence or diffuses between cells By Maurice A. Dow, Ph.D. non-genetic. However, non-clonal patterns Region 4, Ontario, Canada are somewhat more likely to be environmen- Patterns help to identify possible causes Any characteristic can be variegated but tal or non-genetic. By looking at the patterns of pigmentation usually we think of variegated leaves or flow- Clonal sectors (see glossary) can provide in individual cells we can get general clues ers and of differences in color. However, var- some information about when during devel- about the causes of the variegation. For iegation can be present in both plants and opment the event occurred. Large sectors example a pattern on the upper epidermis of animals and in any tissue and affect any char- indicate the event occurred early during a variegated flower or leaf which is repeated acteristic. Variegation does not need to be development of the tissue or organ. Small and very similar to a pattern on its lower epi- obvious to the unaided human eye. It can be sectors indicate that the event occurred late dermis is unlikely to be genetic2. defined as any visible differences in the during development1. Few sectors indicate appearance or phenotype of the cells in a tis- that the event is infrequent or rare.
    [Show full text]
  • Synthetic Conversion of Leaf Chloroplasts Into Carotenoid-Rich Plastids Reveals Mechanistic Basis of Natural Chromoplast Development
    Synthetic conversion of leaf chloroplasts into carotenoid-rich plastids reveals mechanistic basis of natural chromoplast development Briardo Llorentea,b,c,1, Salvador Torres-Montillaa, Luca Morellia, Igor Florez-Sarasaa, José Tomás Matusa,d, Miguel Ezquerroa, Lucio D’Andreaa,e, Fakhreddine Houhouf, Eszter Majerf, Belén Picóg, Jaime Cebollag, Adrian Troncosoh, Alisdair R. Ferniee, José-Antonio Daròsf, and Manuel Rodriguez-Concepciona,f,1 aCentre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain; bARC Center of Excellence in Synthetic Biology, Department of Molecular Sciences, Macquarie University, Sydney NSW 2109, Australia; cCSIRO Synthetic Biology Future Science Platform, Sydney NSW 2109, Australia; dInstitute for Integrative Systems Biology (I2SysBio), Universitat de Valencia-CSIC, 46908 Paterna, Valencia, Spain; eMax-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany; fInstituto de Biología Molecular y Celular de Plantas, CSIC-Universitat Politècnica de València, 46022 Valencia, Spain; gInstituto de Conservación y Mejora de la Agrodiversidad, Universitat Politècnica de València, 46022 Valencia, Spain; and hSorbonne Universités, Université de Technologie de Compiègne, Génie Enzymatique et Cellulaire, UMR-CNRS 7025, CS 60319, 60203 Compiègne Cedex, France Edited by Krishna K. Niyogi, University of California, Berkeley, CA, and approved July 29, 2020 (received for review March 9, 2020) Plastids, the defining organelles of plant cells, undergo physiological chromoplasts but into a completely different type of plastids and morphological changes to fulfill distinct biological functions. In named gerontoplasts (1, 2). particular, the differentiation of chloroplasts into chromoplasts The most prominent changes during chloroplast-to-chromo- results in an enhanced storage capacity for carotenoids with indus- plast differentiation are the reorganization of the internal plastid trial and nutritional value such as beta-carotene (provitamin A).
    [Show full text]
  • Microscope Studies on the Morphogenesis of Plastids V
    Bot. Mag. Tokyo 84: 123-136 (March 25, 1971) Electron Microscope Studies on the Morphogenesis of Plastids V. Concerning One-dimensional Metamorphosis of the Plastids in Cryptomeriac Leaves* by Susumu TOYAMA** and Kazuo FUNAZAKIS** Received November 25, 1970 Abstract To know about the mechanism of interconversion of plastids, electron micro- scopic observations were made on Cryptomeria leaves which aquire a reddish brown color in winter and recover their green color in coming spring to summer. In normal green leaves, two different kinds of plastids have been observed, viz, the chloroplasts having well organized grana structure in mesophyll cells and those completely lacking grana lamellae in bundle sheath cells. General feature of plastids in reddish brown leaves, may be summarized as follows : (1) The presence of red granules of rhodoxanthin (a carotenoid), and a well developed lamellar system involving grana- and intergrana-lamellae. (2) The plastoglobules, osmio- philic granules in plastids, increase in number and size as compared with the chloroplasts in normal green leaves. (3) Shrinkage which is one of the character- istic features of senescent plastids is not observed. (4) RNA content in plastid stroma is almost unchanged throughout an entire leaf stage ranging from normal green to subsequent regreening. Basic structure of the plastids in regreened leaves is quite similar to that in winter leaves, except for some increase of thylakoid membrane and decrease of osmiophilic granules. Accordingly, it is presumed that the plastids appearing in reddish brown leaves are not mere chro- moplasts but those having an incipient nature of the chloroplast, since real chromoplasts can not be converted into the chloroplasts.
    [Show full text]
  • Chromoplasts - the Last Stages in Plastid Development
    Int..I. Dev.l!iol. 35: 251-258 (1991) 251 Chromoplasts - the last stages in plastid development NIKOLA LJUBESIC', MERCEDES WRISCHER and ZVONIMIR DEVIDE Ruder Boskovic Institute, Zagreb, Republic of Croatia, Yugoslavia ABSTRACT The results of investigations on the development of chromoplast fine structures in various plants are reviewed. Emphasis is placed on the specific pigment-containing structures and their development during chromoplastformation. There is a large variety of these structures, although four fundamental types can be discerned. These are plastoglobules, membranes, crystals, and tubules. During chromoplast development, various types of structure follow one after the other, or they may even be present simultaneously in the same chrornoplast. Depending on the structures present in chromoplasts their pigment content also varies. It is still not clear whetherthe type of structure defines the pigment content of the chromoplast or vice-versa. Various possible ways of chromoplast devel- opment and dedifferentiation are discussed. KEY WORDS: chrolllnPlasts, rfpvelop1IIl'1II, I)igmer/f~("(/}/I(iillillg .\/rutlures Introduction 1980). Gerontoplasts appear only in senescent cells. They always develop from fully grown, i.e. old, chloroplasts and are unable to Plastids are specific organelles of plant cells. In higher plants multiply. In contrast, chromoplasts present in flower, fruit and root they exist in various forms and have manifold functions. Plastids cells have an active metabolism. They develop mostly from young develop from undifferentiated proplastids present in meristematic chloroplasts and seldom from proplastids, e.g. in some flower petals tissues. Depending on the plant organ and its functions these (Modrusan and Wrischer, 1988), in some fruits (Ljubesic, 1970) proplastids develop into various other plastid types.
    [Show full text]
  • Chromoplast Differentiation in Bell Pepper (Capsicum Annuum) Fruits
    bioRxiv preprint doi: https://doi.org/10.1101/2020.09.29.299313; this version posted September 30, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. RESOURCE Chromoplast differentiation in bell pepper (Capsicum annuum) fruits Anja Rödiger1, 2, Birgit Agne1, 2, Dirk Dobritzsch1, Stefan Helm1, Fränze Müller1, 3, Nina Pötzsch1 and Sacha Baginsky1, 2* 1Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany 2Biochemistry of Plants, Biology and Biotechnology, Ruhr-University Bochum, Bochum, Germany 3Biochemistry and Functional Proteomics, Institute of Biology II, University of Freiburg, Freiburg, Germany Keywords: quantitative proteomics, CN PAGE, plastid differentiation, chromorespiration Running Title: Proteomics of chromoplast differentiation * Correspondence: Sacha Baginsky, Biochemistry of Plants, ND3/126, Universitätsstrasse 150, 44801 Bochum, Germany, Email: [email protected] 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.09.29.299313; this version posted September 30, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Abstract We report here a detailed analysis of the proteome adjustments that accompany chromoplast differentiation from chloroplasts during bell-pepper fruit ripening. While the two photosystems are disassembled and their constituents degraded, the cytochrome b6f complex, the ATPase complex as well as Calvin cycle enzymes are maintained at high levels up to fully mature chromoplasts.
    [Show full text]
  • The-Plant-Cell.Pdf
    Levetin−McMahon: Plants II. Introduction to Plant 2. The Plant Cell © The McGraw−Hill and Society, Fifth Edition Life: Botanical Principles Companies, 2008 UNIT II CHAPTER OUTLINE Early Studies of Cells 20 The Cell Wall 22 The Protoplast 22 Membranes 22 Moving Into and Out of Cells 22 Organelles 23 A CLOSER LOOK 2.1 Origin of Chloroplasts and Mitochondria 25 The Nucleus 26 Cell Division 26 The Cell Cycle 26 Prophase 27 Metaphase 27 Anaphase 27 Telophase 27 Cytokinesis 27 Chapter Summary 30 Review Questions 30 Further Reading 30 KEY CONCEPTS 1. The Cell Theory establishes that the cell is the basic unit of life, that all living organisms are composed of cells, and that cells arise from preexisting cells. 2. Plant cells are eukaryotic, having an organized nucleus and membrane-bound organelles. 3. Substances can move into and out of cells by diffusion and osmosis. 4. Mitosis, followed by cytokinesis, results in two genetically identical daughter cells. Growth, replacement of cells, and asexual reproduction all depend on the process of cell division. CHAPTER 2 The Plant Cell Plantlets are produced by vegetative reproduction on the leaf margin of kalanchoe. Mitosis is the underlying cell division for vegetative or asexual reproduction. 19 Levetin−McMahon: Plants II. Introduction to Plant 2. The Plant Cell © The McGraw−Hill and Society, Fifth Edition Life: Botanical Principles Companies, 2008 20 UNIT II Introduction to Plant Life: Botanical Principles ll plants (and every other living organism) are com- posed of cells. In some algae and fungi, the whole A organism consists of a single cell, but angiosperms are complex multicellular organisms composed of many dif- ferent types of cells.
    [Show full text]
  • The Unique Topologies of N6-Adenosine Methylation (M6a) in Land-Plant Mitochondria and Their Putative Effects on Organellar Gene-Expression
    bioRxiv preprint doi: https://doi.org/10.1101/717579; this version posted July 28, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. The unique topologies of N6-Adenosine methylation (m6A) in land-plant mitochondria and their putative effects on organellar gene-expression Omer Murik1,2,*, Sam Aldrin Chandran1,3,*, Keren Nevo-Dinur1, Laure D. Sultan1, Corinne Best1, Yuval Stein1, Carina Hazan4 and Oren Ostersetzer-Biran1,†, 1 Dept. of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus - Givat Ram, Jerusalem 9190401, Israel. 2 Current address: Medical Genetics Institute, Shaare Zedek Medical Center, Jerusalem, Israel 3 Current address: School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, India. 4 The Institute of Chemistry, Analytical Chemistry Lab, The Hebrew University of Jerusalem, Edmond J. Safra Campus - Givat Ram, Jerusalem 9190401, Israel. *Both authors contributed equally to this manuscript †Address correspondence to: Oren Ostersetzer-Biran, PhD, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel. Tel. +972-2-658- 5191; Fax, +972-2-658-5191; E-mail, [email protected] Running title: “N6-adenosinemethylation (m6A) modifications in plant mitochondria” 1 bioRxiv preprint doi: https://doi.org/10.1101/717579; this version posted July 28, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.
    [Show full text]
  • Truncated Non-Nuclear Transposable Elements in Grapevine: a Mini Review
    PLANT SCIENCES TRUNCATED NON-NUCLEAR TRANSPOSABLE ELEMENTS IN GRAPEVINE: A MINI REVIEW A.V. Milovanov1, J.Tello2, U.C.M. Anhalt2, A. Forneck2 1Kuban State Agrarian University, Department of Viticulture, Krasnodar, Russia 2University of Natural Resources and Life Sciences, Vienna, Department of Crop Sciences, Division of Viticulture and Pomology, Tulln, Austria In this mini-review we present insight to the non-nuclear transposable elements and in silico analysis of miniature inverted transposable elements (MITEs) in the grapevine mitochondrial genome. Here we report the identification of 17 truncated se- quences in grapevine (Vitis vinifera L.) mitochondrial genome which expectedly belongs to the four ancient transposon fami- lies (hAT, Tc1Mariner, Mutator and PIF/Harbinger). Some sequences with a high rate of homology in chloroplast and nuclear genomes were also identified. Thus, it suggests the intercellular gene transfer between these three organelles. These partial sequences showed a high level of similitude with full MITE sequences, and they were found in their inner region, supporting their MITE origin. Further analysis revealed these sequences in other life kingdoms (including eubacteria and archaea), which indicates their ancient origin. Further research showed that 13 out of the 17 sequences are conserved domains of the genes where they are located, suggesting their contribution to gene evolution. Therefore, we suppose that more studies of nature, origin and functional meaning of these sequences and their fusion with genes are
    [Show full text]
  • Naturally Occurring Variation in the Promoter of the Chromoplast-Specific Cyc-B Gene in Tomato Can Be Used to Modulate Levels of Β-Carotene in Ripe Tomato Fruit
    Naturally occurring variation in the promoter of the chromoplast-specific Cyc-B gene in tomato can be used to modulate levels of β-carotene in ripe tomato fruit THESIS Presented in Partial Fulfillment of the Requirements for the Degree Master of Science in the Graduate School of The Ohio State University By Caleb James Orchard Graduate Program in Horticulture and Crop Science The Ohio State University 2014 Thesis Committee: Dr. David Francis, “Advisor” Dr. Leah McHale Dr. Joseph Scheerens Dr. Steven Schwartz Copyright by Caleb James Orchard 2014 Abstract β-carotene in tomato is an important carotenoid for human health due to its pro- vitamin A activity. Although many carotenoids exhibit provitamin A activity and are available in food crops, Vitamin A deficiency remains the leading cause of preventable blindness in many developing countries. In tomato (S. lycopersicum, L.), the B gene (Cyc- B) encodes a chromoplast-specific lycopene-β-cyclase that converts trans-lycopene to β- carotene. Prior research suggests that DNA sequence variation in the promoter of B may be responsible for the high β-carotene Beta phenotype. We examined the carotenoid profiles of vintage and contemporary tomato varieties to identify sources of high β- carotene. Red tomatoes had a range from 0.2 – 0.97 mg/100 g fresh weight of β-carotene, while several orange-fruited varieties had 1.67 – 4.0 mg/100 g. The non-transcribed region 5′ to the B gene (promoter) contains significant nucleotide variation, with eleven unique haplotypes across 1850 bp of sequence. Sequence analysis suggested that the B promoter was derived from wild tomato species.
    [Show full text]
  • Unique Chromoplast Organisation and Carotenoid Gene Expression in Carotenoid‑Rich Carrot Callus
    Planta https://doi.org/10.1007/s00425-018-2988-5 ORIGINAL ARTICLE Unique chromoplast organisation and carotenoid gene expression in carotenoid‑rich carrot callus Tomasz Oleszkiewicz1 · Magdalena Klimek‑Chodacka1 · Anna Milewska‑Hendel2 · Maciej Zubko3 · Danuta Stróż3 · Ewa Kurczyńska2 · Aleksandra Boba4 · Jan Szopa4,5 · Rafal Baranski1 Received: 5 June 2018 / Accepted: 15 August 2018 © The Author(s) 2018 Abstract Main conclusion The new model orange callus line, similar to carrot root, was rich in carotenoids due to altered expression of some carotenogenesis-associated genes and possessed unique diversity of chromoplast ultrastructure. Callus induced from carrot root segments cultured in vitro is usually pale yellow (p-y) and poor in carotenoids. A unique, non-engineered callus line of dark orange (d-o) colour was developed in this work. The content of carotenoid pigments in d-o callus was at the same level as in an orange carrot storage root and nine-fold higher than in p-y callus. Carotenoids accumu- lated mainly in abundant crystalline chromoplasts that are also common in carrot root but not in p-y callus. Using transmission electron microscopy, other types of chromoplasts were also found in d-o callus, including membranous chromoplasts rarely identifed in plants and not observed in carrot root until now. At the transcriptional level, most carotenogenesis-associated genes were upregulated in d-o callus in comparison to p-y callus, but their expression was downregulated or unchanged when compared to root tissue. Two pathway steps were critical and could explain the massive carotenoid accumulation in this tissue. The geranylgeranyl diphosphate synthase gene involved in the biosynthesis of carotenoid precursors was highly expressed, while the β-carotene hydroxylase gene involved in β-carotene conversion to downstream xanthophylls was highly repressed.
    [Show full text]
  • Nonphotosynthetic Parasitic Plant (Chloroplast DNA/Epifagus Virginiana/Transtdon/Rascriptlon/Photosyntbesis) KENNETH H
    Proc. Natl. Acad. Sci. USA Vol. 89, pp. 10648-10652, November 1992 Evolution Function and evolution of a minimal plastid genome from a nonphotosynthetic parasitic plant (chloroplast DNA/Epifagus virginiana/transtdon/rascriptlon/photosyntbesis) KENNETH H. WOLFE*, CLIFFORD W. MORDENt, AND JEFFREY D. PALMERS Department of Biology, Indiana University, Bloomington, IN 47405 Communicated by Michael T. Clegg, August 3, 1992 (receivedfor review April 15, 1992) ABSTRACT Complete nucleotide sequencing shows that cies such as tobacco (1). Nevertheless, the genome is func- the plastid genome ofEpifagus virginiana, a nonphotosynthetic tional: transcripts of plastid rRNA and protein genes have parasitic flowering plant, lacks all genes for photosynthesis and been identified (ref. 2; S. Ems and J.D.P., unpublished data), chlororespiration found in chloroplast genomes ofgreen plants. and the maintenance of many intact and conserved genes The 70,028-base-pair genome contains only 42 genes, at least implies that mRNAs are translated. We hypothesize that the 38 of which specify components of the gene-expression appa- Epifagus plastid genome has remained active after the loss of ratus of the plastid. Moreover, all chloroplast-encoded RNA photosynthesis because one or a few of its protein genes is polymerase genes and many tRNA and ribosomal protein genes involved in a nonbioenergetic process. have been lost. Since the genome is functional, nuclear gene products must compensate for some gene losses by means of MATERIALS AND METHODS previously unsuspected import mechanisms that may operate Libraries covering the entire mapped (2) plastid genome ofE. in all plastids. At least one of the four unassigned protein genes virginiana were made by cloning restriction fragments and in Epifagus plastid DNA must have a nongenetic and nonbioen- PCR products in pBluescript and A DASH II vectors.
    [Show full text]
  • Comparison with Chloroplast DNA, Physi Cal Map, and Gene Localization
    Daffodil Chromoplast DNA: Comparison with Chloroplast DNA, Physi­ cal Map, and Gene Localization Paul Hansmann Institut für Biologie II, Zellbiologie, Schänzlestraße 1, D-7800 Freiburg i. Br. Z. Naturforsch. 42c, 118—122 (1987); received August 14, 1986 Narcissus, Chromoplast DNA, Chloroplast DNA, Physical Map, Gene Localization In daffodil, development of chloroplasts or chromoplasts is not accompanied by plastid DNA modification. This has been shown by comparing the fragment pattern of different restriction endonucleases, and by the lack of methylation of CCGG sequences. A physical map has been constructed for the plastome using the restriction endonucleases Sal I, Pst I, and Bgl I. The fragments containing the genes for the large subunit of ribulose bisphosphate carboxylase/oxygen­ ase (rbcL), the alpha, beta, and epsilon subunits of the ATP synthase complex (atpA, atpB, atpE), cytochrome/(petA), and for the 51 kDa chlorophyll apoprotein of photosystem II (psbB) have been identified. The respective gene locations correspond to those on spinach chloroplast DNA. Introduction protein composition of nucleoids during chloro- and According to the endosymbiont hypothesis, chromoplast differentiation [9]. Further, in continua­ chloroplasts phylogenetically represent the original tion of earlier work on the daffodil plastome [5, plastid type [1]. In the process of evolution, other 9—14] and as a basis for further comparative studies plastid types with different functions have evolved in on the genetic material of chloro- and chromoplasts, connection with the development of organs and cor­ a physical map of the plastome together with the responding cell differentiation. During ontogeny, the localization of some genes is presented. various types of plastids within a plant all develop directly or indirectly from proplastids, and they are Material and Methods interconvertible [2].
    [Show full text]