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Sample records for angiosperms nuphar advena

  1. Comparative chloroplast genomics: Analyses including new sequencesfrom the angiosperms Nuphar advena and Ranunculus macranthus

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    Raubeso, Linda A.; Peery, Rhiannon; Chumley, Timothy W.; Dziubek,Chris; Fourcade, H. Matthew; Boore, Jeffrey L.; Jansen, Robert K.

    2007-03-01

    The number of completely sequenced plastid genomes available is growing rapidly. This new array of sequences presents new opportunities to perform comparative analyses. In comparative studies, it is most useful to compare across wide phylogenetic spans and, within angiosperms, to include representatives from basally diverging lineages such as the new genomes reported here: Nuphar advena (from a basal-most lineage) and Ranunculus macranthus (from the basal group of eudicots). We report these two new plastid genome sequences and make comparisons (within angiosperms, seed plants, or all photosynthetic lineages) to evaluate features such as the status of ycf15 and ycf68 as protein coding genes, the distribution of simple sequence repeats (SSRs) and longer dispersed repeats (SDR), and patterns of nucleotide composition.

  2. Evolution of plant phage-type RNA polymerases: the genome of the basal angiosperm Nuphar advena encodes two mitochondrial and one plastid phage-type RNA polymerases

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    Börner Thomas

    2010-12-01

    Full Text Available Abstract Background In mono- and eudicotyledonous plants, a small nuclear gene family (RpoT, RNA polymerase of the T3/T7 type encodes mitochondrial as well as chloroplast RNA polymerases homologous to the T-odd bacteriophage enzymes. RpoT genes from angiosperms are well characterized, whereas data from deeper branching plant species are limited to the moss Physcomitrella and the spikemoss Selaginella. To further elucidate the molecular evolution of the RpoT polymerases in the plant kingdom and to get more insight into the potential importance of having more than one phage-type RNA polymerase (RNAP available, we searched for the respective genes in the basal angiosperm Nuphar advena. Results By screening a set of BAC library filters, three RpoT genes were identified. Both genomic gene sequences and full-length cDNAs were determined. The NaRpoT mRNAs specify putative polypeptides of 996, 990 and 985 amino acids, respectively. All three genes comprise 19 exons and 18 introns, conserved in their positions with those known from RpoT genes of other land plants. The encoded proteins show a high degree of conservation at the amino acid sequence level, including all functional crucial regions and residues known from the phage T7 RNAP. The N-terminal transit peptides of two of the encoded polymerases, NaRpoTm1 and NaRpoTm2, conferred targeting of green fluorescent protein (GFP exclusively to mitochondria, whereas the third polymerase, NaRpoTp, was targeted to chloroplasts. Remarkably, translation of NaRpoTp mRNA has to be initiated at a CUG codon to generate a functional plastid transit peptide. Thus, besides AGAMOUS in Arabidopsis and the Nicotiana RpoTp gene, N. advena RpoTp provides another example for a plant mRNA that is exclusively translated from a non-AUG codon. In contrast to the RpoT of the lycophyte Selaginella and those of the moss Physcomitrella, which are according to phylogenetic analyses in sister positions to all other phage

  3. Detecting dispersal of Nuphar lutea in river corridors using microsatellite markers

    Czech Academy of Sciences Publication Activity Database

    Fér, T.; Hroudová, Zdenka

    2008-01-01

    Roč. 53, č. 7 (2008), s. 1409-1422. ISSN 0046-5070 R&D Projects: GA AV ČR(CZ) KJB6111304 Institutional research plan: CEZ:AV0Z60050516 Keywords : Nuphar lutea * dispersal * river corridors Subject RIV: EF - Botanics Impact factor: 2.704, year: 2008

  4. Early evolution of angiosperms

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ While many characters have been used to define the nature of the angiosperms in living plants, the list must be reduced to a single character that can be found in the fossil record in order to proceed with our search for the earliest flowering plants.

  5. Identifying the Basal Angiosperm Node in Chloroplast GenomePhylogenies: Sampling One's Way Out of the Felsenstein Zone

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    Leebens-Mack, Jim; Raubeson, Linda A.; Cui, Liying; Kuehl,Jennifer V.; Fourcade, Matthew H.; Chumley, Timothy W.; Boore, JeffreyL.; Jansen, Robert K.; dePamphilis, Claude W.

    2005-05-27

    While there has been strong support for Amborella and Nymphaeales (water lilies) as branching from basal-most nodes in the angiosperm phylogeny, this hypothesis has recently been challenged by phylogenetic analyses of 61 protein-coding genes extracted from the chloroplast genome sequences of Amborella, Nymphaea and 12 other available land plant chloroplast genomes. These character-rich analyses placed the monocots, represented by three grasses (Poaceae), as sister to all other extant angiosperm lineages. We have extracted protein-coding regions from draft sequences for six additional chloroplast genomes to test whether this surprising result could be an artifact of long-branch attraction due to limited taxon sampling. The added taxa include three monocots (Acorus, Yucca and Typha), a water lily (Nuphar), a ranunculid(Ranunculus), and a gymnosperm (Ginkgo). Phylogenetic analyses of the expanded DNA and protein datasets together with microstructural characters (indels) provided unambiguous support for Amborella and the Nymphaeales as branching from the basal-most nodes in the angiospermphylogeny. However, their relative positions proved to be dependent on method of analysis, with parsimony favoring Amborella as sister to all other angiosperms, and maximum likelihood and neighbor-joining methods favoring an Amborella + Nympheales clade as sister. The maximum likelihood phylogeny supported the later hypothesis, but the likelihood for the former hypothesis was not significantly different. Parametric bootstrap analysis, single gene phylogenies, estimated divergence dates and conflicting in del characters all help to illuminate the nature of the conflict in resolution of the most basal nodes in the angiospermphylogeny. Molecular dating analyses provided median age estimates of 161 mya for the most recent common ancestor of all extant angiosperms and 145 mya for the most recent common ancestor of monocots, magnoliids andeudicots. Whereas long sequences reduce variance in

  6. Schmeissneria: A missing link to angiosperms?

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    Cui Jinzhong

    2007-02-01

    Full Text Available Abstract Background The origin of angiosperms has been under debate since the time of Darwin. While there has been much speculation in past decades about pre-Cretaceous angiosperms, including Archaefructus, these reports are controversial. The earliest reliable fossil record of angiosperms remains restricted to the Cretaceous, even though recent molecular phylogenetic studies suggest an origin for angiosperms much earlier than the current fossil record. Results In this paper, after careful SEM and light microscopic work, we report fossils with angiospermous traits of the Jurassic age. The fossils were collected from the Haifanggou Formation (middle Jurassic in western Liaoning, northeast China. They include two female structures and an associated leaf on the same slab. One of the female structures is physically connected to the apex of a short shoot. The female organs are borne in pairs on short peduncles that are arranged along the axis of the female structure. Each of the female organs has a central unit that is surrounded by an envelope with characteristic longitudinal ribs. Each central unit has two locules completely separated by a vertical septum. The apex of the central unit is completely closed. The general morphology places these fossils into the scope of Schmeissneria, an early Jurassic genus that was previously attributed to Ginkgoales. Conclusion Because the closed carpel is a character only found in angiosperms, the closed apex of the central unit suggests the presence of angiospermy in Schmeissneria. This angiospermous trait implies either a Jurassic angiosperm or a new seed plant group parallel to angiosperms and other known seed plants. As an angiosperm, the Liassic age (earliest Jurassic of Schmeissneria microstachys would suggest an origin of angiosperms during the Triassic. Although still uncertain, this could have a great impact on our perspective of the history, diversity and systematics of seed plants and angiosperms.

  7. CO2 and CH4 fluxes across a Nuphar lutea (L. Sm. stand

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    Scott C. Neubauer

    2012-01-01

    Full Text Available Floating-leaved rhizophytes can significantly alter net carbon dioxide (CO2 and methane (CH4 exchanges with the atmosphere in freshwater shallow environments. In particular, CH4 efflux can be enhanced by the aerenchyma-mediated mass flow, while CO2 release from supersaturated waters can be reversed by the plant uptake. Additionally, the floating leaves bed can hamper light penetration and oxygen (O2 diffusion from the atmosphere, thus altering the dissolved gas dynamics in the water column. In this study, net fluxes of CO2 and CH4 were measured seasonally across vegetated [Nuphar lutea (L. Sm.] and free water surfaces in the Busatello wetland (Northern Italy. Concomitantly, dissolved gas concentrations were monitored in the water column and N. lutea leaf production was estimated by means of biomass harvesting. During the vegetative period (May-August, the yellow waterlily stand resulted a net sink for atmospheric carbon (from 97.5 to 110.6 g C-CO2 m-2, while the free water surface was a net carbon source (166.3 g C-CO2 m-2. Both vegetated and plant-free areas acted as CH4 sources, with an overall carbon release comprised between 71.6 and 113.3 g C-CH4 m-2. On the whole, water column chemistry was not affected by the presence of the floating leaves; moreover, no significant differences in CH4 efflux were evidenced between the vegetated and plant-free areas. In general, this study indicates that the colonization of shallow aquatic ecosystems by N. lutea might not have the same drastic effect reported for free-floating macrophytes.

  8. A combinatorial morphospace for angiosperm pollen

    Science.gov (United States)

    Mander, Luke

    2016-04-01

    The morphology of angiosperm (flowering plant) pollen is extraordinarily diverse. This diversity results from variations in the morphology of discrete anatomical components. These components include the overall shape of a pollen grain, the stratification of the exine, the number and form of any apertures, the type of dispersal unit, and the nature of any surface ornamentation. Different angiosperm pollen morphotypes reflect different combinations of these discrete components. In this talk, I ask the following question: given the anatomical components of angiosperm pollen that are known to exist in the plant kingdom, how many unique biologically plausible combinations of these components are there? I explore this question from the perspective of enumerative combinatorics using an algorithm I have written in the Python programming language. This algorithm (1) calculates the number of combinations of these components; (2) enumerates those combinations; and (3) graphically displays those combinations. The result is a combinatorial morphospace that reflects an underlying notion that the process of morphogenesis in angiosperm pollen can be thought of as an n choose k counting problem. I compare the morphology of extant and fossil angiosperm pollen grains to this morphospace, and suggest that from a combinatorial point of view angiosperm pollen is not as diverse as it could be, which may be a result of developmental constraints.

  9. Formation and development of sperms in angiosperms

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    S. Tatintseva

    2014-01-01

    Spermiogelnesis has been studied in a large number of Angiosperm species characterizing different levels of phylogenetic system. The formation and development of male gamets can be described as formation of sperm cells that undergo ontogenesis which stimulates changes up to full maturity of the pollen grain. The process of ontogenesis is aimed at creating a suitable delivery system by the pollen tube to a female gamete.

  10. Angiosperms, Los Tuxtlas Biosphere Reserve, Veracruz, Mexico

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    S. Mandujano; Dunn, J. C.; Benítez-Malvido, J.; Arroyo-Rodríguez, V.

    2009-01-01

    The Los Tuxtlas Reserve has been heavily deforested and fragmented since the 1970’s. Although the floraof Los Tuxtlas has been described previously, most floristic lists come from the large forest reserve of the Los Tuxtlasfield station. Here we present a check list of Angiosperms recorded in 45 rainforest fragments (< 1 to 266 ha) located inthree landscapes with different levels of deforestation. We sampled all trees, shrubs, lianas, palms and herbs withdiameter at breast height (dbh)

  11. Angiosperms, Los Tuxtlas Biosphere Reserve, Veracruz, Mexico

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    Mandujano, S.

    2009-01-01

    Full Text Available The Los Tuxtlas Reserve has been heavily deforested and fragmented since the 1970’s. Although the floraof Los Tuxtlas has been described previously, most floristic lists come from the large forest reserve of the Los Tuxtlasfield station. Here we present a check list of Angiosperms recorded in 45 rainforest fragments (< 1 to 266 ha located inthree landscapes with different levels of deforestation. We sampled all trees, shrubs, lianas, palms and herbs withdiameter at breast height (dbh

  12. The Early Flowers and Angiosperm Evolution

    DEFF Research Database (Denmark)

    Friis, Else Marie; Crane, P.R.; Pedersen, Kaj Raunsgaard

    based on research into Early and Late Cretaceous fossil floras from Europe and North America, the authors draw on direct palaeontological evidence of the pattern of angiosperm evolution through time. Synthesising palaeobotanical data with information from living plants, this unique book explores the...... evolutionary history of flowering plants from their earliest phases in obscurity to their dominance in modern vegetation. The discussion provides comprehensive biological and geological background information, before moving on to summarise the fossil record in detail. Including previously unpublished results...

  13. Ectomycorrhizas from a Lower Eocene angiosperm forest.

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    Beimforde, Christina; Schäfer, Nadine; Dörfelt, Heinrich; Nascimbene, Paul C; Singh, Hukam; Heinrichs, Jochen; Reitner, Joachim; Rana, Rajendra S; Schmidt, Alexander R

    2011-12-01

    The development of mycorrhizal associations is considered a key innovation that enabled vascular plants to extensively colonize terrestrial habitats. Here, we present the first known fossil ectomycorrhizas from an angiosperm forest. Our fossils are preserved in a 52 million-yr-old piece of amber from the Tadkeshwar Lignite Mine of Gujarat State, western India. The amber was produced by representatives of Dipterocarpaceae in an early tropical broadleaf forest. The ectomycorrhizas were investigated using light microscopy and field emission scanning electron microscopy. Dissolving the amber surrounding one of the fossils allowed ultrastructural analyses and Raman spectroscopy. Approx. 20 unramified, cruciform and monopodial-pinnate ectomycorrhizas are fossilized adjacent to rootlets, and different developmental stages of the fossil mycorrhizas are delicately preserved in the ancient resin. Compounds of melanins were detectable in the dark hyphae. The mycobiont, Eomelanomyces cenococcoides gen. et spec. nov., is considered to be an ascomycete; the host is most likely a dipterocarp representative. An early ectomycorrhizal association may have conferred an evolutionary advantage on dipterocarps. Our find indicates that ectomycorrhizas occurred contemporaneously within both gymnosperms (Pinaceae) and angiosperms (Dipterocarpaceae) by the Lower Eocene. PMID:22074339

  14. Design of biomimetic camouflage materials based on angiosperm leaf organs

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The micro structures and reflectance spectra of angiosperm leaves were compared with those of angiosperm petals. The study indicated that angiosperm leaf organs had identical micro structures and reflectance characteristics in the wave band of near infrared. Micro structures and compositions of leaf organs were the crucial factors influencing their reflectance spectra. The model of biomimetic materials based on angiosperm leaf organs was introduced and verified. From 300 to 2600 nm, the similarity coefficients of reflectance spectra of the foam containing water and Platanus Orientalis Linn. leaves were all above 0.969. The biomimetic camou- flage material exhibited almost the same reflectance spectra with those of green leaves in ultraviolet, visible and near infrared wave bands. And its "concolor and conspectrum" effect might take on reconnaissance of hyperspectral and ultra hy- perspectral imaging.

  15. Why does biparental plastid inheritance revive in angiosperms?

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    Zhang, Quan; Sodmergen

    2010-03-01

    It is widely believed that plastid and mitochondrial genomes are inherited through the maternal parent. In plants, however, paternal transmission of these genomes is frequently observed, especially for the plastid genome. A male gametic trait, called potential biparental plastid inheritance (PBPI), occurs in up to 20% of angiosperm genera, implying a strong tendency for plastid transmission from the male lineage. Why do plants receive organelles from the male parents? Are there clues in plastids that will help to elucidate the evolution of plants? Reconstruction of the ancestral state of plastid inheritance patterns in a phylogenetic context provides insights into these questions. In particular, a recent report demonstrated the unilateral occurrence of PBPI in angiosperms. This result implies that nuclear cytoplasmic conflicts, a basic driving force for altering the mode of organelle inheritance, might have arisen specifically in angiosperms. Based on existing evidence, it is likely that biparental inheritance may have occurred to rescue angiosperm species with defective plastids. PMID:20052516

  16. Angiosperms additions to flora of Peru

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    Eric F. Rodríguez

    2006-10-01

    Full Text Available We present here 131 new additions to the angiosperm flora of Peru from recent collections in the north of Peru, mostly from department of Amazonas (provinces of Bagua and Condorcanqui and department of Cajamarca (province of San Ignacio. This new contribution is the result of field and herbarium studies by the various authors in this region from 1993 to 2002, and represents the combined effort of personnel from the Herbarium Truxillense (HUT and the Herbarium of the Missouri Botanical Garden (MO as part of the Flora of Peru Project. The species reported here were compared against the list of species documented in the «Catalogue of Flowering Plants and Gymnosperms of Peru» (Brako & Zarucchi, 1993 and «Ten years of additions to the flora of Peru: 1993- 2003» (Ulloa Ulloa et al., 2004. The new taxa are organized in three categories: 18 species new to science, six new nomenclatural combinations and 107 new records, thereby enlarging their geographical distribution towards to Peru. Considering the new species and the new records, this contribution adds 125 species to the Peruvian Flora.

  17. Evolution of angiosperm seed disperser mutualisms: the timing of origins and their consequences for coevolutionary interactions between angiosperms and frugivores.

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    Eriksson, Ove

    2016-02-01

    The origins of interactions between angiosperms and fruit-eating seed dispersers have attracted much attention following a seminal paper on this topic by Tiffney (1984). This review synthesizes evidence pertaining to key events during the evolution of angiosperm-frugivore interactions and suggests some implications of this evidence for interpretations of angiosperm-frugivore coevolution. The most important conclusions are: (i) the diversification of angiosperm seed size and fleshy fruits commenced around 80 million years ago (Mya). The diversity of seed sizes, fruit sizes and fruit types peaked in the Eocene around 55 to 50 Mya. During this first phase of the interaction, angiosperms and animals evolving frugivory expanded into niche space not previously utilized by these groups, as frugivores and previously not existing fruit traits appeared. From the Eocene until the present, angiosperm-frugivore interactions have occurred within a broad frame of existing niche space, as defined by fruit traits and frugivory, motivating a separation of the angiosperm-frugivore interactions into two phases, before and after the peak in the early Eocene. (ii) The extinct multituberculates were probably the most important frugivores during the early radiation phase of angiosperm seeds and fleshy fruits. Primates and rodents are likely to have been important in the latter part of this first phase. (iii) Flying frugivores, birds and bats, evolved during the second phase, mainly during the Oligocene and Miocene, thus exploiting an existing diversity of fleshy fruits. (iv) A drastic climate shift around the Eocene-Oligocene boundary (around 34 Mya) resulted in more semi-open woodland vegetation, creating patchily occurring food resources for frugivores. This promoted evolution of a 'flying frugivore niche' exploited by birds and bats. In particular, passerines became a dominant frugivore group worldwide. (v) Fleshy fruits evolved at numerous occasions in many angiosperm families

  18. Angiosperm phylogeny inferred from sequences of four mitochondrial genes

    Institute of Scientific and Technical Information of China (English)

    Yin-Long QIU; Zhi-Duan CHEN; Libo LI; Bin WANG; Jia-Yu XUE; Tory A. HENDRY; Rui-Qi LI; Joseph W. BROWN; Yang LIU; Geordan T. HUDSON

    2010-01-01

    An angiosperm phylogeny was reconstructed in a maximum likelihood analysis of sequences of four mitochondrial genes, atpl, matR, had5, and rps3, from 380 species that represent 376 genera and 296 families of seed plants. It is largely congruent with the phylogeny of angiosperms reconstructed from chloroplast genes atpB, matK, and rbcL, and nuclear 18S rDNA. The basalmost lineage consists of Amborella and Nymphaeales (including Hydatellaceae). Austrobaileyales follow this clade and are sister to the mesangiosperms, which include Chloranthaceae, Ceratophyllum, magnoliids, monocots, and eudicots. With the exception of Chloranthaceae being sister to Ceratophyllum, relationships among these five lineages are not well supported. In eudicots, Ranunculales, Sabiales, Proteales, Trochodendrales, Buxales, Gunnerales, Saxifragales, Vitales, Berberidopsidales, and Dilleniales form a basal grade of lines that diverged before the diversification of rosids and asterids. Within rosids, the COM (Celastrales-Oxalidales-Malpighiales) clade is sister to malvids (or rosid Ⅱ), instead of to the nitrogen-fixing clade as found in all previous large-scale molecular analyses of angiosperms. Santalales and Caryophyllales are members of an expanded asterid clade. This study shows that the mitochondrial genes are informative markers for resolving relationships among genera, families, or higher rank taxa across angiosperms. The low substitution rates and low homoplasy levels of the mitochondrial genes relative to the chloroplast genes, as found in this study, make them particularly useful for reconstructing ancient phylogenetic relationships. A mitochondrial gene-based angiosperm phylogeny provides an independent and essential reference for comparison with hypotheses of angiosperm phylogeny based on chloroplast genes, nuclear genes, and non-molecular data to reconstruct the underlying organismal phylogeny.

  19. STUDY OF AQUATIC ANGIOSPERMIC PLANTS OF ANAND CITY, GUJARAT, INDIA

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    K. R. PATEL1 AND N. K. PATEL2

    2014-06-01

    Full Text Available The present study deals with the taxonomic study of Aquatic Angiosperms growing throughout the Anand city. The plants are listed along with their brief taxonomic account of each species with current nomenclature, vernacular name, family and uses. The  collected plants are systematically observed during present work, During my study I observed various aquatic angiospermic plants such as   Ceratophyllum demersum, Colocasia esculenta, Eichhornia crassipes, Ipomoea aquatica, Nymphoides indicum, Ludwigia repens, Polygonum orientale, Typha elephantina, Lemna perpusilla, Spirodella polyrrhiza, Xanthium indicum, Phyllanthus reticulatus, Cynodon dactylon, Hydrilla verticillata were very common. Whereas Nymphaea nouchali, Polygonum barbatum, Scirpus articulatus were very rare in the study area.

  20. The Pace and Shape of Senescence in Angiosperms

    DEFF Research Database (Denmark)

    Baudisch, Annette; Salguero-Gómez, Roberto; Jones, Owen; Wrycza, Tomasz; Mbeau-Ache, Cyril; Franco, Miguel; Colchero, Fernando

    2013-01-01

    phylogenetic relationships using a resolved supertree. 4. In contrast to the animal kingdom, most angiosperms (93%) show no senescence. Senescence is observed among phanerophytes (i.e. trees), but not among any other growth form (e.g. epiphytes, chamaephytes or cryptopyhtes). Yet, most phanerophytes (81%) do...

  1. Evolutionary aspects of life forms in angiosperm families

    NARCIS (Netherlands)

    Kremer, P; VanAndel, J

    1995-01-01

    The distribution patterns of life forms among extant families, subclasses and classes are described with the aim of detecting evolutionary trends. The explosive diversification of angiosperms constrains the possibilities for detecting such trends. Moreover, the extant groups of seed plants are only

  2. Epiphytic leafy liverworts diversified in angiosperm-dominated forests

    Science.gov (United States)

    Feldberg, Kathrin; Schneider, Harald; Stadler, Tanja; Schäfer-Verwimp, Alfons; Schmidt, Alexander R.; Heinrichs, Jochen

    2014-08-01

    Recent studies have provided evidence for pulses in the diversification of angiosperms, ferns, gymnosperms, and mosses as well as various groups of animals during the Cretaceous revolution of terrestrial ecosystems. However, evidence for such pulses has not been reported so far for liverworts. Here we provide new insight into liverwort evolution by integrating a comprehensive molecular dataset with a set of 20 fossil age constraints. We found evidence for a relative constant diversification rate of generalistic liverworts (Jungermanniales) since the Palaeozoic, whereas epiphytic liverworts (Porellales) show a sudden increase of lineage accumulation in the Cretaceous. This difference is likely caused by the pronounced response of Porellales to the ecological opportunities provided by humid, megathermal forests, which were increasingly available as a result of the rise of the angiosperms.

  3. Angiosperm polyploids and their road to evolutionary success

    OpenAIRE

    Fawcett, Jeffrey A.; Van de Peer, Yves; Jeffrey A, FAWCETT

    2010-01-01

    The abundance of polyploidy among flowering plants has long been recognized, and recent studies have uncovered multiple ancient polyploidization events in the evolutionary history of several angiosperm lineages. Once polyploids are formed they must get locally established and then propagate and survive while adapting to different environments and avoiding extinction. This might ultimately lead to their long-term evolutionary success, where their descendant lineages survive for tens of million...

  4. Role of proline and GABA in sexual reproduction of angiosperms

    OpenAIRE

    Biancucci, Marco; Mattioli, Roberto; Forlani, Giuseppe; Funck, Dietmar; Costantino, Paolo; Trovato, Maurizio

    2015-01-01

    Two glutamate derivatives, proline and γ-aminobutyric acid (GABA), appear to play pivotal roles in different aspects of sexual reproduction in angiosperms, although their precise function in plant reproduction and the molecular basis of their action are not yet fully understood. Proline and GABA have long been regarded as pivotal amino acids in pollen vitality and fertility. Proline may constitute up to 70% of the free amino acid pool in pollen grains and it has been recently shown that Arabi...

  5. New universal matK primers for DNA barcoding angiosperms

    Institute of Scientific and Technical Information of China (English)

    Jing YU; Jian-Hua XUE; Shi-Liang ZHOU

    2011-01-01

    The chloroplast maturase K gene (matK) is one of the most variable coding genes of angiosperms and has been suggested to be a "barcode" for land plants. However, matK exhibits low amplification and sequencing rates due to low universality of currently available primers and mononucleotide repeats. To resolve these technical problems, we evaluated the entire matK region to find a region of 600-800 bp that is highly variable, represents the best of all matK regions with priming sites conservative enough to design universal primers, and avoids the mononucleotide repeats. After careful evaluation, a region in the middle was chosen and a pair of primers named natK472F and matK1248R was designed to amplify and sequence the matK fragment of approximately 776 bp. This region encompasses the most variable sites, represents the entire matK region best, and also exhibits high amplification rates and quality of sequences. The universality of this primer pair was tested using 58 species from 47 families of angiosperm plants. The primers showed a strong amplification (93.1%) and sequencing (92.6%)successes in the species tested. We propose that the new primers will solve, in part, the problems encountered when using matK and promote the adoption of matK as a DNA barcode for angiosperms.

  6. Leaf evolution in Southern Hemisphere conifers tracks the angiosperm ecological radiation

    OpenAIRE

    Biffin, Ed; Brodribb, Timothy J.; Hill, Robert S.; Thomas, Philip; Lowe, Andrew J.

    2011-01-01

    The angiosperm radiation has been linked to sharp declines in gymnosperm diversity and the virtual elimination of conifers from the tropics. The conifer family Podocarpaceae stands as an exception with highest species diversity in wet equatorial forests. It has been hypothesized that efficient light harvesting by the highly flattened leaves of several podocarp genera facilitates persistence with canopy-forming angiosperms, and the angiosperm ecological radiation may have preferentially favour...

  7. Endophytic bacterial community of a Mediterranean marine angiosperm (Posidonia oceanica

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    Neus eGarcias-Bonet

    2012-09-01

    Full Text Available Bacterial endophytes are crucial for the survival of many terrestrial plants, but little is known about the presence and importance of bacterial endophytes of marine plants. We conducted a survey of the endophytic bacterial community of the long-living Mediterranean marine angiosperm Posidonia oceanica in surface-sterilized tissues (roots, rhizomes and leaves by DGGE. A total of 26 Posidonia oceanica meadows around the Balearic Islands were sampled, and the band patterns obtained for each meadow were compared for the three sampled tissues. Endophytic bacterial sequences were detected in most of the samples analyzed. A total of 34 OTUs (Operational Taxonomic Units were detected. The main OTUs of endophytic bacteria present in P. oceanica tissues belonged primarily to Proteobacteria (α, γ and δ subclasses and Bacteroidetes. The OTUs found in roots significantly differed from those of rhizomes and leaves. Moreover, some OTUs were found to be associated to each type of tissue. Bipartite network analysis revealed differences in the bacterial endophyte communities present on different islands. The results of this study provide a pioneering step toward the characterization of the endophytic bacterial community associated with tissues of a marine angiosperm and reveal the presence of bacterial endophytes that differed among locations and tissue types.

  8. Floral gene resources from basal angiosperms for comparative genomics research

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    Zhang Xiaohong

    2005-03-01

    Full Text Available Abstract Background The Floral Genome Project was initiated to bridge the genomic gap between the most broadly studied plant model systems. Arabidopsis and rice, although now completely sequenced and under intensive comparative genomic investigation, are separated by at least 125 million years of evolutionary time, and cannot in isolation provide a comprehensive perspective on structural and functional aspects of flowering plant genome dynamics. Here we discuss new genomic resources available to the scientific community, comprising cDNA libraries and Expressed Sequence Tag (EST sequences for a suite of phylogenetically basal angiosperms specifically selected to bridge the evolutionary gaps between model plants and provide insights into gene content and genome structure in the earliest flowering plants. Results Random sequencing of cDNAs from representatives of phylogenetically important eudicot, non-grass monocot, and gymnosperm lineages has so far (as of 12/1/04 generated 70,514 ESTs and 48,170 assembled unigenes. Efficient sorting of EST sequences into putative gene families based on whole Arabidopsis/rice proteome comparison has permitted ready identification of cDNA clones for finished sequencing. Preliminarily, (i proportions of functional categories among sequenced floral genes seem representative of the entire Arabidopsis transcriptome, (ii many known floral gene homologues have been captured, and (iii phylogenetic analyses of ESTs are providing new insights into the process of gene family evolution in relation to the origin and diversification of the angiosperms. Conclusion Initial comparisons illustrate the utility of the EST data sets toward discovery of the basic floral transcriptome. These first findings also afford the opportunity to address a number of conspicuous evolutionary genomic questions, including reproductive organ transcriptome overlap between angiosperms and gymnosperms, genome-wide duplication history, lineage

  9. Rapid and accurate pyrosequencing of angiosperm plastid genomes

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    Farmerie William G

    2006-08-01

    Full Text Available Abstract Background Plastid genome sequence information is vital to several disciplines in plant biology, including phylogenetics and molecular biology. The past five years have witnessed a dramatic increase in the number of completely sequenced plastid genomes, fuelled largely by advances in conventional Sanger sequencing technology. Here we report a further significant reduction in time and cost for plastid genome sequencing through the successful use of a newly available pyrosequencing platform, the Genome Sequencer 20 (GS 20 System (454 Life Sciences Corporation, to rapidly and accurately sequence the whole plastid genomes of the basal eudicot angiosperms Nandina domestica (Berberidaceae and Platanus occidentalis (Platanaceae. Results More than 99.75% of each plastid genome was simultaneously obtained during two GS 20 sequence runs, to an average depth of coverage of 24.6× in Nandina and 17.3× in Platanus. The Nandina and Platanus plastid genomes shared essentially identical gene complements and possessed the typical angiosperm plastid structure and gene arrangement. To assess the accuracy of the GS 20 sequence, over 45 kilobases of sequence were generated for each genome using conventional sequencing. Overall error rates of 0.043% and 0.031% were observed in GS 20 sequence for Nandina and Platanus, respectively. More than 97% of all observed errors were associated with homopolymer runs, with ~60% of all errors associated with homopolymer runs of 5 or more nucleotides and ~50% of all errors associated with regions of extensive homopolymer runs. No substitution errors were present in either genome. Error rates were generally higher in the single-copy and noncoding regions of both plastid genomes relative to the inverted repeat and coding regions. Conclusion Highly accurate and essentially complete sequence information was obtained for the Nandina and Platanus plastid genomes using the GS 20 System. More importantly, the high accuracy

  10. Cellulose Orientation in the Outer Epidermal Wall of Angiosperm Roots: Implications for Biosystematics

    OpenAIRE

    KERSTENS, SVEN; VERBELEN, JEAN‐PIERRE

    2002-01-01

    The net orientation of cellulose fibrils in the outer epidermal wall of the root elongation zone of 57 angiosperm species belonging to 29 families was determined by means of Congo Red fluorescence and polarization confocal microscopy. The angiosperms can be divided in three groups. In all but four plant families, the net orientation of the cellulose fibrils is transverse to the root axis. Three families, the Poaceae, Juncaceae and Cyperaceae, have a totally different organization. In the root...

  11. Unique responsiveness of angiosperm stomata to elevated CO2 explained by calcium signalling.

    Directory of Open Access Journals (Sweden)

    Timothy J Brodribb

    Full Text Available Angiosperm and conifer tree species respond differently when exposed to elevated CO2, with angiosperms found to dynamically reduce water loss while conifers appear insensitive. Such distinct responses are likely to affect competition between these tree groups as atmospheric CO2 concentration rises. Seeking the mechanism behind this globally important phenomenon we targeted the Ca(2+-dependent signalling pathway, a mediator of stomatal closure in response to elevated CO2, as a possible explanation for the differentiation of stomatal behaviours. Sampling across the diversity of vascular plants including lycophytes, ferns, gymnosperms and angiosperms we show that only angiosperms possess the stomatal behaviour and prerequisite genetic coding, linked to Ca(2+-dependent stomatal signalling. We conclude that the evolution of Ca(2+-dependent stomatal signalling gives angiosperms adaptive benefits in terms of highly efficient water use, but that stomatal sensitivity to high CO2 may penalise angiosperm productivity relative to other plant groups in the current era of soaring atmospheric CO2.

  12. Role of proline and GABA in sexual reproduction of angiosperms.

    Science.gov (United States)

    Biancucci, Marco; Mattioli, Roberto; Forlani, Giuseppe; Funck, Dietmar; Costantino, Paolo; Trovato, Maurizio

    2015-01-01

    Two glutamate derivatives, proline and γ-aminobutyric acid (GABA), appear to play pivotal roles in different aspects of sexual reproduction in angiosperms, although their precise function in plant reproduction and the molecular basis of their action are not yet fully understood. Proline and GABA have long been regarded as pivotal amino acids in pollen vitality and fertility. Proline may constitute up to 70% of the free amino acid pool in pollen grains and it has been recently shown that Arabidopsis mutants affected in the first and rate-limiting step in proline synthesis produce aberrant and infertile pollen grains, indicating that proline synthesis is required for pollen development and fertility. Concerning GABA, a large body of evidence points to this glutamate derivative as a key determinant of post-pollination fertilization. Intriguingly, proline has also been associated with pollination, another aspect of sexual reproduction, since honeybees were reported to show a strong preference for proline-enriched nectars. In this review, we survey current knowledge on the roles of proline and GABA in plant fertility, and discuss future perspectives potentially capable to improve our understanding on the functions of these amino acids in pollen development, pollination, and pollen tube guidance. PMID:26388884

  13. Bark thickness across the angiosperms: more than just fire.

    Science.gov (United States)

    Rosell, Julieta A

    2016-07-01

    Global variation in total bark thickness (TBT) is traditionally attributed to fire. However, bark is multifunctional, as reflected by its inner living and outer dead regions, meaning that, in addition to fire protection, other factors probably contribute to TBT variation. To address how fire, climate, and plant size contribute to variation in TBT, inner bark thickness (IBT) and outer bark thickness (OBT), I sampled 640 species spanning all major angiosperm clades and 18 sites with contrasting precipitation, temperature, and fire regime. Stem size was by far the main driver of variation in thickness, with environment being less important. IBT was closely correlated with stem diameter, probably for metabolic reasons, and, controlling for size, was thicker in drier and hotter environments, even fire-free ones, probably reflecting its water and photosynthate storage role. OBT was less closely correlated with size, and was thicker in drier, seasonal sites experiencing frequent fires. IBT and OBT covaried loosely and both contributed to overall TBT variation. Thickness variation was higher within than across sites and was evolutionarily labile. Given high within-site diversity and the multiple selective factors acting on TBT, continued study of the different drivers of variation in bark thickness is crucial to understand bark ecology. PMID:26890029

  14. Utility of the Amborella trichopoda expansin superfamily in elucidating the history of angiosperm expansins.

    Science.gov (United States)

    Seader, Victoria H; Thornsberry, Jennifer M; Carey, Robert E

    2016-03-01

    Expansins form a superfamily of plant proteins that assist in cell wall loosening during growth and development. The superfamily is divided into four families: EXPA, EXPB, EXLA, and EXLB (Sampedro and Cosgrove in Genome Biol 6:242, 2005. doi: 10.1186/gb-2005-6-12-242 ). Previous studies on Arabidopsis, rice, and Populus trichocarpa have clarified the evolutionary history of expansins in angiosperms (Sampedro et al. in Plant J 44:409-419, 2005. doi: 10.1111/j.1365-313X.2005.02540.x ). Amborella trichopoda is a flowering plant that diverged very early. Thus, it is a sister lineage to all other extant angiosperms (Amborella Genome Project in 342:1241089, 2013. doi: 10.1126/science.1241089 ). Because of this relationship, comparing the A. trichopoda expansin superfamily with those of other flowering plants may indicate which expansin genes were present in the last common ancestor of all angiosperms. The A. trichopoda expansin superfamily was assembled using BLAST searches with angiosperm expansin queries. The search results were analyzed and annotated to isolate the complete A. trichopoda expansin superfamily. This superfamily is similar to other angiosperm expansin superfamilies, but is somewhat smaller. This is likely because of a lack of genome duplication events (Amborella Genome Project 2013). Phylogenetic and syntenic analyses of A. trichopoda expansins have improved our understanding of the evolutionary history of expansins in angiosperms. Nearly all of the A. trichopoda expansins were placed into an existing Arabidopsis-rice expansin clade. Based on the results of phylogenetic and syntenic analyses, we estimate there were 12-13 EXPA genes, 2 EXPB genes, 1 EXLA gene, and 2 EXLB genes in the last common ancestor of all angiosperms. PMID:26646380

  15. Ecological determinants of mean family age of angiosperm trees in forest communities in China

    Science.gov (United States)

    Qian, Hong; Chen, Shengbin

    2016-01-01

    Species assemblage in a local community is determined by the interplay of evolutionary and ecological processes. The Tropical Niche Conservatism hypothesis proposes mechanisms underlying patterns of biodiversity in biological communities along environmental gradients. This hypothesis predicts that, among other things, clades in areas with warm or wet environments are, on average, older than those in areas with cold or dry environments. Focusing on angiosperm trees in forests, this study tested the age-related prediction of the Tropical Niche Conservatism hypothesis. We related the mean family age of angiosperm trees in 57 local forests from across China with 23 current and paleo-environmental variables, which included all major temperature- and precipitation-related variables. Our study shows that the mean family age of angiosperm trees in local forests was positively correlated with temperature and precipitation. This finding is consistent with the age-related prediction of the Tropical Niche Conservatism hypothesis. Approximately 85% of the variance in the mean family age of angiosperm trees was explained by temperature-related variables, and 81% of the variance in the mean family age of angiosperm trees was explained by precipitation-related variables. Climatic conditions at the Last Glacial Maximum did not explain additional variation in mean family age after accounting for current environmental conditions. PMID:27354109

  16. Darwin's second 'abominable mystery': Why are there so many angiosperm species?

    Science.gov (United States)

    Crepet, William L; Niklas, Karl J

    2009-01-01

    The rapid diversification and ecological dominance of the flowering plants beg the question "Why are there so many angiosperm species and why are they so successful?" A number of equally plausible hypotheses have been advanced in response to this question, among which the most widely accepted highlights the mutually beneficial animal-plant relationships that are nowhere better developed nor more widespread than among angiosperm species and their biotic vectors for pollination and dispersal. Nevertheless, consensus acknowledges that there are many other attributes unique to or characteristic of the flowering plants. In addition, the remarkable coevolution of the angiosperms and pollination/dispersal animal agents could be an effect of the intrinsic adaptability of the flowering plants rather than a primary cause of their success, suggesting that the search for underlying causes should focus on an exploration of the genetic and epigenetic mechanisms that might facilitate adaptive evolution and speciation. Here, we explore angiosperm diversity promoting attributes in their general form and draw particular attention to those that, either individually or collectively, have been shown empirically to favor high speciation rates, low extinction rates, or broad ecological tolerances. Among these are the annual growth form, homeotic gene effects, asexual/sexual reproduction, a propensity for hybrid polyploidy, and apparent "resistance" to extinction. Our survey of the literature suggests that no single vegetative, reproductive, or ecological feature taken in isolation can account for the evolutionary success of the angiosperms. Rather, we believe that the answer to Darwin's second "abominable mystery" lies in a confluence of features that collectively make the angiosperms unique among the land plants. PMID:21628194

  17. Unequal plastid distribution during the development of the male gametophyte of angiosperms

    Directory of Open Access Journals (Sweden)

    R. Hagemann

    2014-02-01

    Full Text Available The difference between the uniparental maternal and biparental type of plastid inheritance is based upon a relatively simple mechanism. In the uniparental type plastids are excluded from the generative or siperm cells during the firts pollen mitosis or during pollen development. In some angiosperms this exclusion is completely lacking or carried out partially.

  18. Effects of plant diversity on primary production and species interactions in brackish water angiosperm communities

    DEFF Research Database (Denmark)

    Salo, Tiina; Gustafsson, Camilla; Boström, Christoffer

    2009-01-01

    plant productivity in brackish water angiosperm communities, a 14 wk field experiment was conducted. Using a replacement design with a standardized initial aboveground biomass, shoots of Zostera marina, Potamogeton filiformis and P. perfoliatus were planted on a shallow, sandy bottom in replicated...

  19. Did homeodomain proteins duplicate before the origin of angiosperms, fungi, and metazoa?

    Science.gov (United States)

    Bharathan, G; Janssen, B J; Kellogg, E A; Sinha, N

    1997-12-01

    Homeodomain proteins are transcription factors that play a critical role in early development in eukaryotes. These proteins previously have been classified into numerous subgroups whose phylogenetic relationships are unclear. Our phylogenetic analysis of representative eukaryotic sequences suggests that there are two major groups of homeodomain proteins, each containing sequences from angiosperms, metazoa, and fungi. This result, based on parsimony and neighbor-joining analyses of primary amino acid sequences, was supported by two additional features of the proteins. The two protein groups are distinguished by an insertion/deletion in the homeodomain, between helices I and II. In addition, an amphipathic alpha-helical secondary structure in the region N terminal of the homeodomain is shared by angiosperm and metazoan sequences in one group. These results support the hypothesis that there was at least one duplication of homeobox genes before the origin of angiosperms, fungi, and metazoa. This duplication, in turn, suggests that these proteins had diverse functions early in the evolution of eukaryotes. The shared secondary structure in angiosperm and metazoan sequences points to an ancient conserved functional domain. PMID:9391098

  20. Did homeodomain proteins duplicate before the origin of angiosperms, fungi, and metazoa?

    Science.gov (United States)

    Bharathan, Geeta; Janssen, Bart-Jan; Kellogg, Elizabeth A.; Sinha, Neelima

    1997-01-01

    Homeodomain proteins are transcription factors that play a critical role in early development in eukaryotes. These proteins previously have been classified into numerous subgroups whose phylogenetic relationships are unclear. Our phylogenetic analysis of representative eukaryotic sequences suggests that there are two major groups of homeodomain proteins, each containing sequences from angiosperms, metazoa, and fungi. This result, based on parsimony and neighbor-joining analyses of primary amino acid sequences, was supported by two additional features of the proteins. The two protein groups are distinguished by an insertion/deletion in the homeodomain, between helices I and II. In addition, an amphipathic alpha-helical secondary structure in the region N terminal of the homeodomain is shared by angiosperm and metazoan sequences in one group. These results support the hypothesis that there was at least one duplication of homeobox genes before the origin of angiosperms, fungi, and metazoa. This duplication, in turn, suggests that these proteins had diverse functions early in the evolution of eukaryotes. The shared secondary structure in angiosperm and metazoan sequences points to an ancient conserved functional domain. PMID:9391098

  1. Ontogenetic shifts in plant-plant interactions in a rare cycad within angiosperm communities.

    Science.gov (United States)

    Álvarez-Yépiz, Juan C; Búrquez, Alberto; Dovčiak, Martin

    2014-06-01

    Gymnosperms and angiosperms can co-occur within the same habitats but key plant traits are thought to give angiosperms an evolutionary competitive advantage in many ecological settings. We studied ontogenetic changes in competitive and facilitative interactions between a rare gymnosperm (Dioon sonorense, our target species) and different plant and abiotic neighbours (conspecific-cycads, heterospecific-angiosperms, or abiotic-rocks) from 2007 to 2010 in an arid environment of northwestern Mexico. We monitored survival and growth of seedlings, juveniles, and adults of the cycad Dioon sonorense to evaluate how cycad survival and relative height growth rate (RHGR) responded to intra- and interspecific competition, canopy openness, and nearest neighbour. We tested spatial associations among D. sonorense life stages and angiosperm species and measured ontogenetic shifts in cycad shade tolerance. Canopy openness decreased cycad survival while intraspecific competition decreased survival and RHGR during early ontogeny. Seedling survival was higher in association with rocks and heterospecific neighbours where intraspecific competition was lower. Shade tolerance decreased with cycad ontogeny reflecting the spatial association of advanced stages with more open canopies. Interspecific facilitation during early ontogeny of our target species may promote its persistence in spite of increasing interspecific competition in later stages. We provide empirical support to the long-standing assumption that marginal rocky habitats serve as refugia from angiosperm competition for slow-growing gymnosperms such as cycads. The lack of knowledge of plant-plant interactions in rare or endangered species may hinder developing efficient conservation strategies (e.g. managing for sustained canopy cover), especially under the ongoing land use and climatic changes. PMID:24652529

  2. Exploring Early Angiosperm Fire Feedbacks using Coupled Experiments and Modelling Approaches to Estimate Cretaceous Palaeofire Behaviour

    Science.gov (United States)

    Belcher, Claire; Hudpsith, Victoria

    2016-04-01

    Using the fossil record we are typically limited to exploring linkages between palaeoecological changes and palaeofire activity by assessing the abundance of charcoals preserved in sediments. However, it is the behaviour of fires that primarily governs their ecological effects. Therefore, the ability to estimate variations in aspects of palaeofire behaviour such as palaeofire intensity and rate of spread would be of key benefit toward understanding the coupled evolutionary history of ecosystems and fire. The Cretaceous Period saw major diversification in land plants. Previously, conifers (gymnosperms) and ferns (pteridophytes) dominated Earth's ecosystems until flowering plants (angiosperms) appear in the fossil record of the Early Cretaceous (~135Ma). We have created surface fire behaviour estimates for a variety of angiosperm invasion scenarios and explored the influence of Cretaceous superambient atmospheric oxygen levels on the fire behaviour occurring in these new Cretaceous ecosystems. These estimates are then used to explore the hypothesis that the early spread of the angiosperms was promoted by the novel fire regimes that they created. In order to achieve this we tested the flammability of Mesozoic analogue fuel types in controlled laboratory experiments using an iCone calorimeter, which measured the ignitability as well as the effective heat of combustion of the fuels. We then used the BehavePlus fire behaviour modelling system to scale up our laboratory results to the ecosystem scale. Our results suggest that fire-angiosperm feedbacks may have occurred in two phases: The first phase being a result of weedy angiosperms providing an additional easily ignitable fuel that enhanced both the seasonality and frequency of surface fires. In the second phase, the addition of shrubby understory fuels likely expanded the number of ecosystems experiencing more intense surface fires, resulting in enhanced mortality and suppressed post-fire recruitment of gymnosperms

  3. Testing the recent theories for the origin of the hermaphrodite flower by comparison of the transcriptomes of gymnosperms and angiosperms

    Directory of Open Access Journals (Sweden)

    Tavares Raquel

    2010-08-01

    Full Text Available Abstract Background Different theories for the origin of the angiosperm hermaphrodite flower make different predictions concerning the overlap between the genes expressed in the male and female cones of gymnosperms and the genes expressed in the hermaphrodite flower of angiosperms. The Mostly Male (MM theory predicts that, of genes expressed primarily in male versus female gymnosperm cones, an excess of male orthologs will be expressed in flowers, excluding ovules, while Out Of Male (OOM and Out Of Female (OOF theories predict no such excess. Results In this paper, we tested these predictions by comparing the transcriptomes of three gymnosperms (Ginkgo biloba, Welwitschia mirabilis and Zamia fisheri and two angiosperms (Arabidopsis thaliana and Oryza sativa, using EST data. We found that the proportion of orthologous genes expressed in the reproductive organs of the gymnosperms and in the angiosperms flower is significantly higher than the proportion of orthologous genes expressed in the reproductive organs of the gymnosperms and in the angiosperms vegetative tissues, which shows that the approach is correct. However, we detected no significant differences between the proportion of gymnosperm orthologous genes expressed in the male cone and in the angiosperms flower and the proportion of gymnosperm orthologous genes expressed in the female cone and in the angiosperms flower. Conclusions These results do not support the MM theory prediction of an excess of male gymnosperm genes expressed in the hermaphrodite flower of the angiosperms and seem to support the OOM/OOF theories. However, other explanations can be given for the 1:1 ratio that we found. More abundant and more specific (namely carpel and ovule expression data should be produced in order to further test these theories.

  4. Preferential fertilization in Plumbago: Ultrastructural evidence for gamete-level recognition in an angiosperm

    OpenAIRE

    Russell, Scott D.

    1985-01-01

    Gametic fusion patterns in the angiosperm Plumbago zeylanica were determined by using cytoplasmically dimorphic sperm cells differing in mitochondrion and plastid content and then identifying paternal organelles through their ultrastructural characteristics within the maternal cytoplasm at the time of fertilization. The virtual absence of plastids within the sperm cell that is physically associated with the vegetative nucleus allows paternal plastids to be used to trace the fate of the two ma...

  5. CenH3 evolution in diploids and polyploids of three angiosperm genera

    OpenAIRE

    Masonbrink, Rick E.; Gallagher, Joseph P.; Jareczek, Josef J; Renny-Byfield, Simon; Grover, Corrinne E.; Gong, Lei; Wendel, Jonathan F.

    2014-01-01

    Background Centromeric DNA sequences alone are neither necessary nor sufficient for centromere specification. The centromere specific histone, CenH3, evolves rapidly in many species, perhaps as a coevolutionary response to rapidly evolving centromeric DNA. To gain insight into CenH3 evolution, we characterized patterns of nucleotide and protein diversity among diploids and allopolyploids within three diverse angiosperm genera, Brassica, Oryza, and Gossypium (cotton), with a focus on evidence ...

  6. Did homeodomain proteins duplicate before the origin of angiosperms, fungi, and metazoa?

    OpenAIRE

    Bharathan, Geeta; Janssen, Bart-Jan; Kellogg, Elizabeth A.; Sinha, Neelima

    1997-01-01

    Homeodomain proteins are transcription factors that play a critical role in early development in eukaryotes. These proteins previously have been classified into numerous subgroups whose phylogenetic relationships are unclear. Our phylogenetic analysis of representative eukaryotic sequences suggests that there are two major groups of homeodomain proteins, each containing sequences from angiosperms, metazoa, and fungi. This result, based on parsimony and neighbor-joining analyses of primary ami...

  7. Oil biosynthesis in a basal angiosperm: transcriptome analysis of Persea Americana mesocarp

    OpenAIRE

    Kilaru, Aruna; Cao, Xia; Dabbs, Parker B.; Sung, Ha-Jung; Rahman, Md. Mahbubur; Thrower, Nicholas; Zynda, Greg; Podicheti, Ram; Ibarra-Laclette, Enrique; Herrera-Estrella, Luis; Mockaitis, Keithanne; Ohlrogge, John B.

    2015-01-01

    Background The mechanism by which plants synthesize and store high amounts of triacylglycerols (TAG) in tissues other than seeds is not well understood. The comprehension of controls for carbon partitioning and oil accumulation in nonseed tissues is essential to generate oil-rich biomass in perennial bioenergy crops. Persea americana (avocado), a basal angiosperm with unique features that are ancestral to most flowering plants, stores ~ 70 % TAG per dry weight in its mesocarp, a nonseed tissu...

  8. A Targeted Enrichment Strategy for Massively Parallel Sequencing of Angiosperm Plastid Genomes

    Directory of Open Access Journals (Sweden)

    Gregory W. Stull

    2013-02-01

    Full Text Available Premise of the study: We explored a targeted enrichment strategy to facilitate rapid and low-cost next-generation sequencing (NGS of numerous complete plastid genomes from across the phylogenetic breadth of angiosperms. Methods and Results: A custom RNA probe set including the complete sequences of 22 previously sequenced eudicot plastomes was designed to facilitate hybridization-based targeted enrichment of eudicot plastid genomes. Using this probe set and an Agilent SureSelect targeted enrichment kit, we conducted an enrichment experiment including 24 angiosperms (22 eudicots, two monocots, which were subsequently sequenced on a single lane of the Illumina GAIIx with single-end, 100-bp reads. This approach yielded nearly complete to complete plastid genomes with exceptionally high coverage (mean coverage: 717×, even for the two monocots. Conclusions: Our enrichment experiment was highly successful even though many aspects of the capture process employed were suboptimal. Hence, significant improvements to this methodology are feasible. With this general approach and probe set, it should be possible to sequence more than 300 essentially complete plastid genomes in a single Illumina GAIIx lane (achieving 50× mean coverage. However, given the complications of pooling numerous samples for multiplex sequencing and the limited number of barcodes (e.g., 96 available in commercial kits, we recommend 96 samples as a current practical maximum for multiplex plastome sequencing. This high-throughput approach should facilitate large-scale plastid genome sequencing at any level of phylogenetic diversity in angiosperms.

  9. Divergence of RNA polymerase α subunits in angiosperm plastid genomes is mediated by genomic rearrangement

    Science.gov (United States)

    Blazier, J. Chris; Ruhlman, Tracey A.; Weng, Mao-Lun; Rehman, Sumaiyah K.; Sabir, Jamal S. M.; Jansen, Robert K.

    2016-01-01

    Genes for the plastid-encoded RNA polymerase (PEP) persist in the plastid genomes of all photosynthetic angiosperms. However, three unrelated lineages (Annonaceae, Passifloraceae and Geraniaceae) have been identified with unusually divergent open reading frames (ORFs) in the conserved region of rpoA, the gene encoding the PEP α subunit. We used sequence-based approaches to evaluate whether these genes retain function. Both gene sequences and complete plastid genome sequences were assembled and analyzed from each of the three angiosperm families. Multiple lines of evidence indicated that the rpoA sequences are likely functional despite retaining as low as 30% nucleotide sequence identity with rpoA genes from outgroups in the same angiosperm order. The ratio of non-synonymous to synonymous substitutions indicated that these genes are under purifying selection, and bioinformatic prediction of conserved domains indicated that functional domains are preserved. One of the lineages (Pelargonium, Geraniaceae) contains species with multiple rpoA-like ORFs that show evidence of ongoing inter-paralog gene conversion. The plastid genomes containing these divergent rpoA genes have experienced extensive structural rearrangement, including large expansions of the inverted repeat. We propose that illegitimate recombination, not positive selection, has driven the divergence of rpoA. PMID:27087667

  10. The SLEEPER genes: a transposase-derived angiosperm-specific gene family

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    Knip Marijn

    2012-10-01

    Full Text Available Abstract Background DAYSLEEPER encodes a domesticated transposase from the hAT-superfamily, which is essential for development in Arabidopsis thaliana. Little is known about the presence of DAYSLEEPER orthologs in other species, or how and when it was domesticated. We studied the presence of DAYSLEEPER orthologs in plants and propose a model for the domestication of the ancestral DAYSLEEPER gene in angiosperms. Results Using specific BLAST searches in genomic and EST libraries, we found that DAYSLEEPER-like genes (hereafter called SLEEPER genes are unique to angiosperms. Basal angiosperms as well as grasses (Poaceae and dicotyledonous plants possess such putative orthologous genes, but SLEEPER-family genes were not found in gymnosperms, mosses and algae. Most species contain more than one SLEEPER gene. All SLEEPERs contain a C2H2 type BED-zinc finger domain and a hATC dimerization domain. We designated 3 motifs, partly overlapping the BED-zinc finger and dimerization domain, which are hallmark features in the SLEEPER family. Although SLEEPER genes are structurally conserved between species, constructs with SLEEPER genes from grapevine and rice did not complement the daysleeper phenotype in Arabidopsis, when expressed under control of the DAYSLEEPER promoter. However these constructs did cause a dominant phenotype when expressed in Arabidopsis. Rice plant lines with an insertion in the RICESLEEPER1 or 2 locus displayed phenotypic abnormalities, indicating that these genes are functional and important for normal development in rice. We suggest a model in which we hypothesize that an ancestral hAT transposase was retrocopied and stably integrated in the genome during early angiosperm evolution. Evidence is also presented for more recent retroposition events of SLEEPER genes, such as an event in the rice genome, which gave rise to the RICESLEEPER1 and 2 genes. Conclusions We propose the ancestral SLEEPER gene was formed after a process of retro

  11. Evolutionary dynamics of microsatellite distribution in plants: insight from the comparison of sequenced brassica, Arabidopsis and other angiosperm species.

    Directory of Open Access Journals (Sweden)

    Jiaqin Shi

    Full Text Available Despite their ubiquity and functional importance, microsatellites have been largely ignored in comparative genomics, mostly due to the lack of genomic information. In the current study, microsatellite distribution was characterized and compared in the whole genomes and both the coding and non-coding DNA sequences of the sequenced Brassica, Arabidopsis and other angiosperm species to investigate their evolutionary dynamics in plants. The variation in the microsatellite frequencies of these angiosperm species was much smaller than those for their microsatellite numbers and genome sizes, suggesting that microsatellite frequency may be relatively stable in plants. The microsatellite frequencies of these angiosperm species were significantly negatively correlated with both their genome sizes and transposable elements contents. The pattern of microsatellite distribution may differ according to the different genomic regions (such as coding and non-coding sequences. The observed differences in many important microsatellite characteristics (especially the distribution with respect to motif length, type and repeat number of these angiosperm species were generally accordant with their phylogenetic distance, which suggested that the evolutionary dynamics of microsatellite distribution may be generally consistent with plant divergence/evolution. Importantly, by comparing these microsatellite characteristics (especially the distribution with respect to motif type the angiosperm species (aside from a few species all clustered into two obviously different groups that were largely represented by monocots and dicots, suggesting a complex and generally dichotomous evolutionary pattern of microsatellite distribution in angiosperms. Polyploidy may lead to a slight increase in microsatellite frequency in the coding sequences and a significant decrease in microsatellite frequency in the whole genome/non-coding sequences, but have little effect on the microsatellite

  12. The complete chloroplast genome sequence of Ampelopsis: gene organization, comparative analysis and phylogenetic relationships to other angiosperms

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    Gurusamy eRaman

    2016-03-01

    Full Text Available Ampelopsis brevipedunculata is an economically important plant that belongs to the Vitaceae family of angiosperms. The phylogenetic placement of Vitaceae is still unresolved. Recent phylogenetic studies suggested that it should be placed in various alternative families including Caryophyllaceae, asteraceae, Saxifragaceae, Dilleniaceae, or with the rest of the rosid families. However, these analyses provided weak supportive results because they were based on only one of several genes. Accordingly, complete chloroplast genome sequences are required to resolve the phylogenetic relationships among angiosperms. Recent phylogenetic analyses based on the complete chloroplast genome sequence suggested strong support for the position of Vitaceae as the earliest diverging lineage of rosids and placed it as a sister to the remaining rosids. These studies also revealed relationships among several major lineages of angiosperms; however, they highlighted the significance of taxon sampling for obtaining accurate phylogenies. In the present study, we sequenced the complete chloroplast genome of A. brevipedunculata and used these data to assess the relationships among 32 angiosperms, including 18 taxa of rosids. The Ampelopsis chloroplast genome is 161,090 bp in length, and includes a pair of inverted repeats of 26,394 bp that are separated by small and large single copy regions of 19,036 bp and 89,266 bp, respectively. The gene content and order of Ampelopsis is identical to many other unrearranged angiosperm chloroplast genomes, including Vitis and tobacco. A phylogenetic tree constructed based on 70 protein-coding genes of 33 angiosperms showed that both Saxifragales and Vitaceae diverged from the rosid clade and formed two clades with 100% bootstrap value. The position of the Vitaceae is sister to Saxifragales, and both are the basal and earliest diverging lineages. Moreover, Saxifragales forms a sister clade to Vitaceae of rosids. Overall, the results of

  13. Mitochondrial DNA suggests at least 11 origins of parasitism in angiosperms and reveals genomic chimerism in parasitic plants

    Directory of Open Access Journals (Sweden)

    Croom Henrietta B

    2007-12-01

    Full Text Available Abstract Background Some of the most difficult phylogenetic questions in evolutionary biology involve identification of the free-living relatives of parasitic organisms, particularly those of parasitic flowering plants. Consequently, the number of origins of parasitism and the phylogenetic distribution of the heterotrophic lifestyle among angiosperm lineages is unclear. Results Here we report the results of a phylogenetic analysis of 102 species of seed plants designed to infer the position of all haustorial parasitic angiosperm lineages using three mitochondrial genes: atp1, coxI, and matR. Overall, the mtDNA phylogeny agrees with independent studies in terms of non-parasitic plant relationships and reveals at least 11 independent origins of parasitism in angiosperms, eight of which consist entirely of holoparasitic species that lack photosynthetic ability. From these results, it can be inferred that modern-day parasites have disproportionately evolved in certain lineages and that the endoparasitic habit has arisen by convergence in four clades. In addition, reduced taxon, single gene analyses revealed multiple horizontal transfers of atp1 from host to parasite lineage, suggesting that parasites may be important vectors of horizontal gene transfer in angiosperms. Furthermore, in Pilostyles we show evidence for a recent host-to-parasite atp1 transfer based on a chimeric gene sequence that indicates multiple historical xenologous gene acquisitions have occurred in this endoparasite. Finally, the phylogenetic relationships inferred for parasites indicate that the origins of parasitism in angiosperms are strongly correlated with horizontal acquisitions of the invasive coxI group I intron. Conclusion Collectively, these results indicate that the parasitic lifestyle has arisen repeatedly in angiosperm evolutionary history and results in increasing parasite genomic chimerism over time.

  14. The genome of the seagrass Zostera marina reveals angiosperm adaptation to the sea

    KAUST Repository

    Olsen, Jeanine L.

    2016-01-27

    Seagrasses colonized the sea1 on at least three independent occasions to form the basis of one of the most productive and widespread coastal ecosystems on the planet2. Here we report the genome of Zostera marina (L.), the first, to our knowledge, marine angiosperm to be fully sequenced. This reveals unique insights into the genomic losses and gains involved in achieving the structural and physiological adaptations required for its marine lifestyle, arguably the most severe habitat shift ever accomplished by flowering plants. Key angiosperm innovations that were lost include the entire repertoire of stomatal genes3, genes involved in the synthesis of terpenoids and ethylene signalling, and genes for ultraviolet protection and phytochromes for far-red sensing. Seagrasses have also regained functions enabling them to adjust to full salinity. Their cell walls contain all of the polysaccharides typical of land plants, but also contain polyanionic, low-methylated pectins and sulfated galactans, a feature shared with the cell walls of all macroalgae4 and that is important for ion homoeostasis, nutrient uptake and O2/CO2 exchange through leaf epidermal cells. The Z. marina genome resource will markedly advance a wide range of functional ecological studies from adaptation of marine ecosystems under climate warming5, 6, to unravelling the mechanisms of osmoregulation under high salinities that may further inform our understanding of the evolution of salt tolerance in crop plants7.

  15. Mechanisms for independent cytoplasmic inheritance of mitochondria and plastids in angiosperms.

    Science.gov (United States)

    Nagata, Noriko

    2010-03-01

    The inheritance of mitochondria and plastids in angiosperms has been categorized into three modes:maternal, biparental and paternal. Many mechanisms have been proposed for maternal inheritance, including: (1) physical exclusion of the organelle itself during pollenmitosis I (PMI); (2) elimination of the organelle by formation of enucleated cytoplasmic bodies (ECB); (3) autophagic degradation of organelles during male gametophyte development; (4) digestion of the organelle after fertilization; and (5)--the most likely possibility--digestion of organellar DNA in generative cells just after PMI. In detailed cytological observations, the presence or absence of mitochondrial and plastid DNA in generative cells corresponds to biparental/paternal inheritance or maternal inheritance of the respective organelle examined genetically. These improved cytological observations demonstrate that the replication or digestion of organellar DNA in young generative cells just after PMI is a critical point determining the mode of cytoplasmic inheritance. This review describes the independent control mechanisms in mitochondria and plastids that lead to differences in cytoplasmic inheritance in angiosperms. PMID:20196234

  16. Recalibrated tree of leaf beetles (Chrysomelidae indicates independent diversification of angiosperms and their insect herbivores.

    Directory of Open Access Journals (Sweden)

    Jesús Gómez-Zurita

    Full Text Available BACKGROUND: The great diversity of the "Phytophaga" (weevils, longhorn beetles and leaf beetles has been attributed to their co-radiation with the angiosperms based on matching age estimates for both groups, but phylogenetic information and molecular clock calibrations remain insufficient for this conclusion. METHODOLOGY: A phylogenetic analysis of the leaf beetles (Chrysomelidae was conducted based on three partial ribosomal gene markers (mitochondrial rrnL, nuclear small and large subunit rRNA including over 3000 bp for 167 taxa representing most major chrysomelid lineages and outgroups. Molecular clock calibrations and confidence intervals were based on paleontological data from the oldest (K-T boundary leaf beetle fossil, ancient feeding traces ascribed to hispoid Cassidinae, and the vicariant split of Nearctic and Palearctic members of the Timarchini. PRINCIPAL FINDINGS: The origin of the Chrysomelidae was dated to 73-79 Mya (confidence interval 63-86 Mya, and most subfamilies were post-Cretaceous, consistent with the ages of all confirmed body fossils. Two major monocot feeding chrysomelid lineages formed widely separated clades, demonstrating independent colonization of this ancient (early Cretaceous angiosperm lineage. CONCLUSIONS: Previous calibrations proposing a much older origin of Chrysomelidae were not supported. Therefore, chrysomelid beetles likely radiated long after the origin of their host lineages and their diversification was driven by repeated radiaton on a pre-existing diverse resource, rather than ancient host associations.

  17. Genome size and ploidy influence angiosperm species' biomass under nitrogen and phosphorus limitation.

    Science.gov (United States)

    Guignard, Maïté S; Nichols, Richard A; Knell, Robert J; Macdonald, Andy; Romila, Catalina-Andreea; Trimmer, Mark; Leitch, Ilia J; Leitch, Andrew R

    2016-06-01

    Angiosperm genome sizes (GS) range c. 2400-fold, and as nucleic acids are amongst the most phosphorus- (P) and nitrogen (N)-demanding cellular biomolecules, we test the hypothesis that a key influence on plant biomass and species composition is the interaction between N and P availability and plant GS. We analysed the impact of different nutrient regimes on above-ground biomass of angiosperm species with different GS, ploidy level and Grime's C-S-R (competitive, stress-tolerant, ruderal) plant strategies growing at the Park Grass Experiment (Rothamsted, UK), established in 1856. The biomass-weighted mean GS of species growing on plots with the addition of both N and P fertilizer were significantly higher than that of plants growing on control plots and plots with either N or P. The plants on these N + P plots are dominated by polyploids with large GS and a competitive plant strategy. The results are consistent with our hypothesis that large genomes are costly to build and maintain under N and P limitation. Hence GS and ploidy are significant traits affecting biomass growth under different nutrient regimes, influencing plant community composition and ecosystem dynamics. We propose that GS is a critical factor needed in models that bridge the knowledge gap between biodiversity and ecosystem functioning. PMID:26875784

  18. The genome of the seagrass Zostera marina reveals angiosperm adaptation to the sea.

    Science.gov (United States)

    Olsen, Jeanine L; Rouzé, Pierre; Verhelst, Bram; Lin, Yao-Cheng; Bayer, Till; Collen, Jonas; Dattolo, Emanuela; De Paoli, Emanuele; Dittami, Simon; Maumus, Florian; Michel, Gurvan; Kersting, Anna; Lauritano, Chiara; Lohaus, Rolf; Töpel, Mats; Tonon, Thierry; Vanneste, Kevin; Amirebrahimi, Mojgan; Brakel, Janina; Boström, Christoffer; Chovatia, Mansi; Grimwood, Jane; Jenkins, Jerry W; Jueterbock, Alexander; Mraz, Amy; Stam, Wytze T; Tice, Hope; Bornberg-Bauer, Erich; Green, Pamela J; Pearson, Gareth A; Procaccini, Gabriele; Duarte, Carlos M; Schmutz, Jeremy; Reusch, Thorsten B H; Van de Peer, Yves

    2016-02-18

    Seagrasses colonized the sea on at least three independent occasions to form the basis of one of the most productive and widespread coastal ecosystems on the planet. Here we report the genome of Zostera marina (L.), the first, to our knowledge, marine angiosperm to be fully sequenced. This reveals unique insights into the genomic losses and gains involved in achieving the structural and physiological adaptations required for its marine lifestyle, arguably the most severe habitat shift ever accomplished by flowering plants. Key angiosperm innovations that were lost include the entire repertoire of stomatal genes, genes involved in the synthesis of terpenoids and ethylene signalling, and genes for ultraviolet protection and phytochromes for far-red sensing. Seagrasses have also regained functions enabling them to adjust to full salinity. Their cell walls contain all of the polysaccharides typical of land plants, but also contain polyanionic, low-methylated pectins and sulfated galactans, a feature shared with the cell walls of all macroalgae and that is important for ion homoeostasis, nutrient uptake and O2/CO2 exchange through leaf epidermal cells. The Z. marina genome resource will markedly advance a wide range of functional ecological studies from adaptation of marine ecosystems under climate warming, to unravelling the mechanisms of osmoregulation under high salinities that may further inform our understanding of the evolution of salt tolerance in crop plants. PMID:26814964

  19. Evolution of Xylan Substitution Patterns in Gymnosperms and Angiosperms: Implications for Xylan Interaction with Cellulose.

    Science.gov (United States)

    Busse-Wicher, Marta; Li, An; Silveira, Rodrigo L; Pereira, Caroline S; Tryfona, Theodora; Gomes, Thiago C F; Skaf, Munir S; Dupree, Paul

    2016-08-01

    The interaction between cellulose and xylan is important for the load-bearing secondary cell wall of flowering plants. Based on the precise, evenly spaced pattern of acetyl and glucuronosyl (MeGlcA) xylan substitutions in eudicots, we recently proposed that an unsubstituted face of xylan in a 2-fold helical screw can hydrogen bond to the hydrophilic surfaces of cellulose microfibrils. In gymnosperm cell walls, any role for xylan is unclear, and glucomannan is thought to be the important cellulose-binding polysaccharide. Here, we analyzed xylan from the secondary cell walls of the four gymnosperm lineages (Conifer, Gingko, Cycad, and Gnetophyta). Conifer, Gingko, and Cycad xylan lacks acetylation but is modified by arabinose and MeGlcA. Interestingly, the arabinosyl substitutions are located two xylosyl residues from MeGlcA, which is itself placed precisely on every sixth xylosyl residue. Notably, the Gnetophyta xylan is more akin to early-branching angiosperms and eudicot xylan, lacking arabinose but possessing acetylation on alternate xylosyl residues. All these precise substitution patterns are compatible with gymnosperm xylan binding to hydrophilic surfaces of cellulose. Molecular dynamics simulations support the stable binding of 2-fold screw conifer xylan to the hydrophilic face of cellulose microfibrils. Moreover, the binding of multiple xylan chains to adjacent planes of the cellulose fibril stabilizes the interaction further. Our results show that the type of xylan substitution varies, but an even pattern of xylan substitution is maintained among vascular plants. This suggests that 2-fold screw xylan binds hydrophilic faces of cellulose in eudicots, early-branching angiosperm, and gymnosperm cell walls. PMID:27325663

  20. Recent Acceleration of Plastid Sequence and Structural Evolution Coincides with Extreme Mitochondrial Divergence in the Angiosperm Genus Silene

    OpenAIRE

    Sloan, Daniel B; Alverson, Andrew J; Wu, Martin; Palmer, Jeffrey D.; Taylor, Douglas R.

    2012-01-01

    The angiosperm genus Silene exhibits some of the most extreme and rapid divergence ever identified in mitochondrial genome architecture and nucleotide substitution rates. These patterns have been considered mitochondrial specific based on the absence of correlated changes in the small number of available nuclear and plastid gene sequences. To better assess the relationship between mitochondrial and plastid evolution, we sequenced the plastid genomes from four Silene species with fully sequenc...

  1. Modes of Gene Duplication Contribute Differently to Genetic Novelty and Redundancy, but Show Parallels across Divergent Angiosperms

    OpenAIRE

    Wang, Yupeng; Wang, Xiyin; Tang, Haibao; Tan, Xu; Ficklin, Stephen P.; Feltus, F. Alex; Andrew H. Paterson

    2011-01-01

    Background Both single gene and whole genome duplications (WGD) have recurred in angiosperm evolution. However, the evolutionary effects of different modes of gene duplication, especially regarding their contributions to genetic novelty or redundancy, have been inadequately explored. Results In Arabidopsis thaliana and Oryza sativa (rice), species that deeply sample botanical diversity and for which expression data are available from a wide range of tissues and physiological conditions, we ha...

  2. Insights into the dynamics of genome size and chromosome evolution in the early diverging angiosperm lineage Nymphaeales (water lilies).

    Science.gov (United States)

    Pellicer, J; Kelly, L J; Magdalena, C; Leitch, I J

    2013-08-01

    Nymphaeales are the most species-rich lineage of the earliest diverging angiosperms known as the ANA grade (Amborellales, Nymphaeales, Austrobaileyales), and they have received considerable attention from morphological, physiological, and ecological perspectives. Although phylogenetic relationships between these three lineages of angiosperms are mainly well resolved, insights at the whole genome level are still limited because of a dearth of information. To address this, genome sizes and chromosome numbers in 34 taxa, comprising 28 species were estimated and analysed together with previously published data to provide an overview of genome size and chromosome diversity in Nymphaeales. Overall, genome sizes were shown to vary 10-fold and chromosome numbers and ploidy levels ranged from 2n = 2x = 18 to 2n = 16x = ∼224. Distinct patterns of genome diversity were apparent, reflecting the differential incidence of polyploidy, changes in repetitive DNA content, and chromosome rearrangements within and between genera. Using model-based approaches, ancestral genome size and basic chromosome numbers were reconstructed to provide insights into the dynamics of genome size and chromosome number evolution. Finally, by combining additional data from Amborellales and Austrobaileyales, a comprehensive overview of genome sizes and chromosome numbers in these early diverging angiosperms is presented. PMID:24168627

  3. Internal habitat quality determines the effects of fragmentation on austral forest climbing and epiphytic angiosperms.

    Directory of Open Access Journals (Sweden)

    Ainhoa Magrach

    Full Text Available Habitat fragmentation has become one of the major threats to biodiversity worldwide, particularly in the case of forests, which have suffered enormous losses during the past decades. We analyzed how changes in patch configuration and habitat quality derived from the fragmentation of austral temperate rainforests affect the distribution of six species of forest-dwelling climbing and epiphytic angiosperms. Epiphyte and vine abundance is primarily affected by the internal characteristics of patches (such as tree size, the presence of logging gaps or the proximity to patch edges rather than patch and landscape features (such as patch size, shape or connectivity. These responses were intimately related to species-specific characteristics such as drought- or shade-tolerance. Our study therefore suggests that plant responses to fragmentation are contingent on both the species' ecology and the specific pathways through which the study area is being fragmented, (i.e. extensive logging that shaped the boundaries of current forest patches plus recent, unregulated logging that creates gaps within patches. Management practices in fragmented landscapes should therefore consider habitat quality within patches together with other spatial attributes at landscape or patch scales.

  4. Emerging roles for microtubules in angiosperm pollen tube growth highlight new research cues

    Directory of Open Access Journals (Sweden)

    Alessandra eMoscatelli

    2015-02-01

    Full Text Available In plants, actin filaments have an important role in organelle movement and cytoplasmic streaming. Otherwise microtubules have a role in restricting organelles to specific areas of the cell and in maintaining organelle morphology. In somatic plant cells, microtubules also participate in cell division and morphogenesis, allowing cells to take their definitive shape in order to perform specific functions. In the latter case, microtubules influence assembly of the cell wall, controlling the delivery of enzymes involved in cellulose synthesis and of wall modulation material to the proper sites.In angiosperm pollen tubes, organelle movement is generally attributed to the acto-myosin system, the main role of which is in distributing organelles in the cytoplasm and in carrying secretory vesicles to the apex for polarized growth. Recent data on membrane trafficking suggests a role of microtubules in fine delivery and repositioning of vesicles to sustain pollen tube growth. This review examines the role of microtubules in secretion and endocytosis, highlighting new research cues regarding cell wall construction and pollen tube-pistil crosstalk, that help unravel the role of microtubules in polarized growth.

  5. Coalescence vs. concatenation: Sophisticated analyses vs. first principles applied to rooting the angiosperms.

    Science.gov (United States)

    Simmons, Mark P; Gatesy, John

    2015-10-01

    It has recently been concluded that phylogenomic data from 310 nuclear genes support the clade of (Amborellales, Nymphaeales) as sister to the remaining angiosperms and that shortcut coalescent phylogenetic methods outperformed concatenation for these data. We falsify both of those conclusions here by demonstrating that discrepant results between the coalescent and concatenation analyses are primarily caused by the coalescent methods applied (MP-EST and STAR) not being robust to the highly divergent and often mis-rooted gene trees that were used. This result reinforces the expectation that low amounts of phylogenetic signal and methodological artifacts in gene-tree reconstruction can be more problematic for shortcut coalescent methods than is the assumption of a single hierarchy for all genes by concatenation methods when these approaches are applied to ancient divergences in empirical studies. We also demonstrate that a third coalescent method, ASTRAL, is more robust to mis-rooted gene trees than MP-EST or STAR, and that both Observed Variability (OV) and Tree Independent Generation of Evolutionary Rates (TIGER), which are two character subsampling procedures, are biased in favor of characters with highly asymmetrical distributions of character states when applied to this dataset. We conclude that enthusiastic application of novel tools is not a substitute for rigorous application of first principles, and that trending methods (e.g., shortcut coalescent methods applied to ancient divergences, tree-independent character subsampling), may be novel sources of previously under-appreciated, systematic errors. PMID:26002829

  6. Variation in ovule and seed size and associated size-number trade-offs in angiosperms.

    Science.gov (United States)

    Greenway, Carly A; Harder, Lawrence D

    2007-05-01

    Unlike pollen and seed size, the extent and causes of variation in ovule size remain unexplored. Based on 45 angiosperm species, we assessed whether intra- and interspecific variation in ovule size is consistent with cost minimization during ovule production or allows maternal plants to dominate conflict with their seeds concerning resource investment. Despite considerable intraspecific variation in ovule volume (mean CV = 0.356), ovule production by few species was subject to a size-number trade-off. Among the sampled species, ovule volume varied two orders of magnitude, whereas seed volume varied four orders of magnitude. Ovule volume varied positively among species with flower mass and negatively with ovule number. Tenuinucellate ovules were generally larger that crassinucellate ovules, and species with apical placentation (which mostly have uniovulate ovaries) had smaller ovules than those with other placentation types. Seed volume varied positively among species with fruit mass and seed development time, but negatively with seed number. Seeds grew a median 93-fold larger than the ovules from which they originated. Our results provide equivocal evidence that selection minimizes ovule size to allow efficient resource allocation after fertilization, but stronger evidence that ovule size affords maternal plants an advantage in parent-offspring conflict. PMID:21636453

  7. Floristic composition and community structure of epiphytic angiosperms in a terra firme forest in central Amazonia

    Directory of Open Access Journals (Sweden)

    Mariana Victória Irume

    2013-06-01

    Full Text Available This survey aimed to describe the floristic composition and structure of the epiphytic community occurring in a terra firme forest in the city of Coari, Brazil, in the Amazon region. Data collection was performed with a 1.5 ha plot method, with which upland, slope and lowland habitats were sampled. All angiosperm epiphytes and their host plants (diameter at breast height > 10 cm were sampled. We recorded 3.528 individuals in 13 families, 48 genera and 164 species. Araceae was the most prevalent family with regard to the importance value and stood out in all related parameters, followed by Bromeliaceae, Cyclanthaceae and Orchidaceae. The species with the highest epiphytic importance values were Guzmania lingulata (L. Mez. and Philodendron linnaei Kunth. The predominant life form was hemiepiphytic. Estimated floristic diversity was 3.2 (H'. The studied epiphytic community was distributed among 727 host plants belonging to 40 families, 123 genera and 324 species. One individual of Guarea convergens T.D. Penn. was the host with the highest richness and abundance of epiphytes. Stems/trunks of host plants were the most colonized segments, and the most favorable habitat for epiphytism was the lowlands, where 84.1% of species and 48.2% of epiphytic specimens were observed.

  8. General Botany of the Angiosperms in high school: a comparative analysis of textbooks

    Directory of Open Access Journals (Sweden)

    Lucas Cardoso Marinho

    2015-12-01

    Full Text Available Much of the textbooks content in Brazil is related to the historical period lived. With the advancement in the field of scientific research, the textbooks have become key pieces in the transfer/adaptation of this knowledge for the basic levels of education influencing positively or negatively in approach and presentation of content. The purpose of this study was to examine comparatively how the contents of General Botany of the Angiosperms are approached in three biology textbooks of high school (1974, 1999 and 2011. The 1974 book have long texts that include an elaborated discussion and there is a tendency to simplify the content. The book of the 1999 presents the content in the form of direct and specific concepts split into separate chapters. In this work, the reduced form compromises the discussion, giving up themes that enrich the study. The book of the 2011 separate the content into different chapters and keeps reducing the content but without losing the quality and clarity of their information. Over the years, from the best understanding of the textbooks objectives and scientific research involving these documents, it is clear that the most current book is more attractive and less dense, contributing of the deconstruct the idea of a boring and decorative Botany.

  9. Fossil evidence for a herbaceous diversification of early eudicot angiosperms during the Early Cretaceous.

    Science.gov (United States)

    Jud, Nathan A

    2015-09-01

    Eudicot flowering plants comprise roughly 70% of land plant species diversity today, but their early evolution is not well understood. Fossil evidence has been largely restricted to their distinctive tricolpate pollen grains and this has limited our understanding of the ecological strategies that characterized their primary radiation. I describe megafossils of an Early Cretaceous eudicot from the Potomac Group in Maryland and Virginia, USA that are complete enough to allow reconstruction of important life-history traits. I draw on quantitative and qualitative analysis of functional traits, phylogenetic analysis and sedimentological evidence to reconstruct the biology of this extinct species. These plants were small and locally rare but widespread, fast-growing herbs. They had complex leaves and they were colonizers of bright, wet, disturbance-prone habitats. Other early eudicot megafossils appear to be herbaceous rather than woody, suggesting that this habit was characteristic of their primary radiation. A mostly herbaceous initial diversification of eudicots could simultaneously explain the heretofore sparse megafossil record as well as their rapid diversification during the Early Cretaceous because the angiosperm capacity for fast reproduction and fast evolution is best expressed in herbs. PMID:26336172

  10. Two photosynthetic mechanisms mediating the low photorespiratory state in submersed aquatic angiosperms.

    Science.gov (United States)

    Salvucci, M E; Bowes, G

    1983-10-01

    The submersed angiosperms Myriophyllum spicatum L. and Hydrilla verticillata (L.f.) Royal exhibited different photosynthetic pulse-chase labeling patterns. In Hydrilla, over 50% of the (14)C was initially in malate and aspartate, but the fate of the malate depended upon the photorespiratory state of the plant. In low photorespiration Hydrilla, malate label decreased rapidly during an unlabeled chase, whereas labeling of sucrose and starch increased. In contrast, for high photorespiration Hydrilla, malate labeling continued to increase during a 2-hour chase. Thus, malate formation occurs in both photorespiratory states, but reduced photorespiration results when this malate is utilized in the light. Unlike Hydrilla, in low photorespiration Myriophyllum, (14)C incorporation was via the Calvin cycle, and less than 10% was in C(4) acids.Ethoxyzolamide, a carbonic anhydrase inhibitor and a repressor of the low photorespiratory state, increased the label in glycolate, glycine, and serine of Myriophyllum. Isonicotinic acid hydrazide increased glycine labeling of low photorespiration Myriophyllum from 14 to 25%, and from 12 to 48% with high photorespiration plants. Similar trends were observed with Hydrilla. Increasing O(2) increased the per cent [(14)C]glycine and the O(2) inhibition of photosynthesis in Myriophyllum. In low photorespiration Myriophyllum, glycine labeling and O(2) inhibition of photosynthesis were independent of the CO(2) level, but in high photorespiration plants the O(2) inhibition was competitively decreased by CO(2). Thus, in low but not high photorespiration plants, glycine labeling and O(2) inhibition appeared to be uncoupled from the external [O(2)]/[CO(2)] ratio.These data indicate that the low photorespiratory states of Hydrilla and Myriophyllum are mediated by different mechanisms, the former being C(4)-like, while the latter resembles that of low CO(2)-grown algae. Both may require carbonic anhydrase to enhance the use of inorganic carbon for

  11. Does multiple paternity affect seed mass in angiosperms? An experimental test in Dalechampia scandens.

    Science.gov (United States)

    Pélabon, C; Albertsen, E; Falahati-Anbaran, M; Wright, J; Armbruster, W S

    2015-09-01

    Flowers fertilized by multiple fathers may be expected to produce heavier seeds than those fertilized by a single father. However, the adaptive mechanisms leading to such differences remain unclear, and the evidence inconsistent. Here, we first review the different hypotheses predicting an increase in seed mass when multiple paternity occurs. We show that distinguishing between these hypotheses requires information about average seed mass, but also about within-fruit variance in seed mass, bias in siring success among pollen donors, and whether siring success and seed mass are correlated. We then report the results of an experiment on Dalechampia scandens (Euphorbiaceae), assessing these critical variables in conjunction with a comparison of seed mass resulting from crosses with single vs. multiple pollen donors. Siring success differed among males when competing for fertilization, but average seed mass was not affected by the number of fathers. Furthermore, paternal identity explained only 3.8% of the variance in seed mass, and siring success was not correlated with the mass of the seeds produced. Finally, within-infructescence variance in seed mass was not affected by the number of fathers. These results suggest that neither differential allocation nor sibling rivalry has any effect on the average mass of seeds in multiply sired fruits in D. scandens. Overall, the limited paternal effects observed in most studies and the possibility of diversification bet hedging among flowers (but not within flowers), suggest that multiple paternity within fruits or infructescence is unlikely to affect seed mass in a large number of angiosperm species. PMID:26174371

  12. A draft of the genome and four transcriptomes of a medicinal and pesticidal angiosperm Azadirachta indica

    Directory of Open Access Journals (Sweden)

    Krishnan Neeraja M

    2012-09-01

    Full Text Available Abstract Background The Azadirachta indica (neem tree is a source of a wide number of natural products, including the potent biopesticide azadirachtin. In spite of its widespread applications in agriculture and medicine, the molecular aspects of the biosynthesis of neem terpenoids remain largely unexplored. The current report describes the draft genome and four transcriptomes of A. indica and attempts to contextualise the sequence information in terms of its molecular phylogeny, transcript expression and terpenoid biosynthesis pathways. A. indica is the first member of the family Meliaceae to be sequenced using next generation sequencing approach. Results The genome and transcriptomes of A. indica were sequenced using multiple sequencing platforms and libraries. The A. indica genome is AT-rich, bears few repetitive DNA elements and comprises about 20,000 genes. The molecular phylogenetic analyses grouped A. indica together with Citrus sinensis from the Rutaceae family validating its conventional taxonomic classification. Comparative transcript expression analysis showed either exclusive or enhanced expression of known genes involved in neem terpenoid biosynthesis pathways compared to other sequenced angiosperms. Genome and transcriptome analyses in A. indica led to the identification of repeat elements, nucleotide composition and expression profiles of genes in various organs. Conclusions This study on A. indica genome and transcriptomes will provide a model for characterization of metabolic pathways involved in synthesis of bioactive compounds, comparative evolutionary studies among various Meliaceae family members and help annotate their genomes. A better understanding of molecular pathways involved in the azadirachtin synthesis in A. indica will pave ways for bulk production of environment friendly biopesticides.

  13. Inference of phylogenetic relationships among key angiosperm lineages using a compatibility method on a molecular data set

    Institute of Scientific and Technical Information of China (English)

    Yin-Long QIU; George F.ESTABROOK

    2008-01-01

    Phylogenetic relationships among the five key angiosperm lineages,Ceratophyllum,Chloranthaceae,eudicots,magnoliids,and monocots,have resisted resolution despite several large-scale analyses sampling taxa and characters extensively and using various analytical methods.Meanwhile,compatibility methods,which were explored together with parsimony and likelihood methods during the early development stage of phylogenetics.have been greatly under-appreciated and not been used to analyze the massive amount of sequence data to reconstruct thye basal angiosperm phylogeny.In this study,we used a compatibility method on a data set of eight genes (mitochondrial atp1,matR,and nad5,plastid atpB,marK,rbcL,and rpoC2,and nuclear 18S rDNA)gathered in an earlier study.We selected two sets of characters that are compatible with more of the other characters than a random character would be with at probabilities of pM<0.1 and p<0.5 respectively.The resulting data matrices were subjected to parsimony and likelihood bootstrap analyses.Our unrooted parsimony analyses showed that Ceratophyllum was immediately related to eudicots,this larger lineage was immediately related to magnoliids,and monocots were closely related to Chloranthaceae.All these relationships received 76%-96% bootstrap support.A likelihood analysis of the 8 gene pM<0.5 compatible site matrix recovered the same topology but with low support.Likelihood analyses of other compatible site matrices produced different topologies that were all weakly supported.The topology reconstructed in the parsimony analyses agrees with the one recovered in the previous study using both parsimony and likelihood methods when no character was eliminated.Parts of this topology have also been recovered in several earlier studies.Hence,this topology plausibly reflects the true relationships among the five key angiosperm lineages.

  14. Barcoding success as a function of phylogenetic relatedness in Viburnum, a clade of woody angiosperms

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    Clement Wendy L

    2012-05-01

    Full Text Available Abstract Background The chloroplast genes matK and rbcL have been proposed as a “core” DNA barcode for identifying plant species. Published estimates of successful species identification using these loci (70-80% may be inflated because they may have involved comparisons among distantly related species within target genera. To assess the ability of the proposed two-locus barcode to discriminate closely related species, we carried out a hierarchically structured set of comparisons within Viburnum, a clade of woody angiosperms containing ca. 170 species (some 70 of which are currently used in horticulture. For 112 Viburnum species, we evaluated rbcL + matK, as well as the chloroplast regions rpl32-trnL, trnH-psbA, trnK, and the nuclear ribosomal internal transcribed spacer region (nrITS. Results At most, rbcL + matK could discriminate 53% of all Viburnum species, with only 18% of the comparisons having genetic distances >1%. When comparisons were progressively restricted to species within major Viburnum subclades, there was a significant decrease in both the discriminatory power and the genetic distances. trnH-psbA and nrITS show much higher levels of variation and potential discriminatory power, and their use in plant barcoding should be reconsidered. As barcoding has often been used to discriminate species within local areas, we also compared Viburnum species within two regions, Japan and Mexico and Central America. Greater success in discriminating among the Japanese species reflects the deeper evolutionary history of Viburnum in that area, as compared to the recent radiation of a single clade into the mountains of Latin America. Conclusions We found very low levels of discrimination among closely related species of Viburnum, and low levels of variation in the proposed barcoding loci may limit success within other clades of long-lived woody plants. Inclusion of the supplementary barcodes trnH-psbA and nrITS increased discrimination rates but

  15. MADS-box genes active in developing pollen cones of Norway spruce (Picea abies) are homologous to the B-class floral homeotic genes in angiosperms.

    Science.gov (United States)

    Sundström, J; Carlsbecker, A; Svensson, M E; Svenson, M; Johanson, U; Theissen, G; Engström, P

    1999-09-01

    The reproductive organs of conifers, the pollen cones and seed cones, differ in morphology from the angiosperm flower in several fundamental respects. In this report we present evidence to suggest that the two plant groups, in spite of these morphological differences and the long evolutionary distance between them, share important features in regulating the development of the reproductive organs. We present the cloning of three genes, DAL11, DAL12, and DAL13, from Norway spruce, all of which are related to the angiosperm B-class of homeotic genes. The B-class genes determine the identities of petals and stamens. They are members of a family of MADS-box genes, which also includes C-class genes that act to determine the identity of carpels and, in concert with B genes specify stamens in the angiosperm flower. Phylogenetic analyses and the presence of B-class specific C-terminal motifs in the DAL protein sequences imply homology to the B-class genes. Specific expression of all three genes in developing pollen cones suggests that the genes are involved in one aspect of B function, the regulation of development of the pollen-bearing organs. The different temporal and spatial expression patterns of the three DAL genes in the developing pollen cones indicate that the genes have attained at least in part distinct functions. The DAL11, DAL12, and 13 expression patterns in the pollen cone partly overlap with that of the previously identified DAL2 gene, which is structurally and functionally related to the angiosperm C-class genes. This result supports the hypothesis that an interaction between B- and C-type genes is required for male organ development in conifers like in the angiosperms. Taken together, our data suggests that central components in the regulatory mechanisms for reproductive organ development are conserved between conifers and angiosperms and, thus, among all seed plants. PMID:10528266

  16. Differential phylogenetic expansions in BAHD acyltransferases across five angiosperm taxa and evidence of divergent expression among Populus paralogues

    Directory of Open Access Journals (Sweden)

    Johnson Virgil E

    2011-05-01

    Full Text Available Abstract Background BAHD acyltransferases are involved in the synthesis and elaboration of a wide variety of secondary metabolites. Previous research has shown that characterized proteins from this family fall broadly into five major clades and contain two conserved protein motifs. Here, we aimed to expand the understanding of BAHD acyltransferase diversity in plants through genome-wide analysis across five angiosperm taxa. We focus particularly on Populus, a woody perennial known to produce an abundance of secondary metabolites. Results Phylogenetic analysis of putative BAHD acyltransferase sequences from Arabidopsis, Medicago, Oryza, Populus, and Vitis, along with previously characterized proteins, supported a refined grouping of eight major clades for this family. Taxon-specific clustering of many BAHD family members appears pervasive in angiosperms. We identified two new multi-clade motifs and numerous clade-specific motifs, several of which have been implicated in BAHD function by previous structural and mutagenesis research. Gene duplication and expression data for Populus-dominated subclades revealed that several paralogous BAHD members in this genus might have already undergone functional divergence. Conclusions Differential, taxon-specific BAHD family expansion via gene duplication could be an evolutionary process contributing to metabolic diversity across plant taxa. Gene expression divergence among some Populus paralogues highlights possible distinctions between their biochemical and physiological functions. The newly discovered motifs, especially the clade-specific motifs, should facilitate future functional study of substrate and donor specificity among BAHD enzymes.

  17. Putting scales into evolutionary time: the divergence of major scale insect lineages (Hemiptera) predates the radiation of modern angiosperm hosts

    Science.gov (United States)

    Vea, Isabelle M.; Grimaldi, David A.

    2016-01-01

    The radiation of flowering plants in the mid-Cretaceous transformed landscapes and is widely believed to have fuelled the radiations of major groups of phytophagous insects. An excellent group to test this assertion is the scale insects (Coccomorpha: Hemiptera), with some 8,000 described Recent species and probably the most diverse fossil record of any phytophagous insect group preserved in amber. We used here a total-evidence approach (by tip-dating) employing 174 morphological characters of 73 Recent and 43 fossil taxa (48 families) and DNA sequences of three gene regions, to obtain divergence time estimates and compare the chronology of the most diverse lineage of scale insects, the neococcoid families, with the timing of the main angiosperm radiation. An estimated origin of the Coccomorpha occurred at the beginning of the Triassic, about 245 Ma [228–273], and of the neococcoids 60 million years later [210–165 Ma]. A total-evidence approach allows the integration of extinct scale insects into a phylogenetic framework, resulting in slightly younger median estimates than analyses using Recent taxa, calibrated with fossil ages only. From these estimates, we hypothesise that most major lineages of coccoids shifted from gymnosperms onto angiosperms when the latter became diverse and abundant in the mid- to Late Cretaceous. PMID:27000526

  18. Cytogenetics of Chilean angiosperms: Advances and prospects Citogenética de angiospermas chilenas: Avances y proyecciones

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    PEDRO JARA-SEGUEL

    2012-03-01

    Full Text Available Cytogenetic data on Chilean angiosperms have been reported since at least eight decades ago; however, much of this information is disperse in diverse sources and is not readily available as a comprehensive document that allows having a general vision on advances and gaps in this matter. The goal of this paper is to summarize the advances and prospets on cytogenetic studies of the Chilean angiosperms based on compiled publications from 1929 to 2010. We found 78 publications supplied by four groups of Chilean researchers and some foreign specialists. Cytogenetic data have been reported for 139 Chilean angiosperm species (2.8 % of the total, which belong to 58 genera and 34 families. During 2001-2010 there was an increase in the number of publications, being available 40 reports including 95 additional species. Based on these data, we hope that such a trend can be maintained in the next decade if the current research groups and young specialists continue to be interested in the study of native plants.Los datos citogenéticos sobre angiospermas chilenas han sido reportados desde al menos ocho décadas atrás; sin embargo, mucha de esta información está dispersa en diversas fuentes y no está disponible como un documento completo que permita tener una visión general sobre los avances y vacíos en esta materia. El objetivo de este trabajo es resumir los avances y proyecciones sobre los estudios citogenéticos disponibles para angiospermas chilenas, basado en publicaciones recopiladas desde 1929 hasta el 2010. Nosotros encontramos 78 publicaciones aportadas por cuatro grupos de investigadores chilenos y por algunos especialistas extranjeros. Datos citogenéticos han sido reportados para 139 especies de angiospermas chilenas (2.8 % del total, las cuales pertenecen a 58 géneros y 34 familias. Durante los años 2001-2010, existió un incremento en el número de publicaciones estando disponibles 40 reportes que incluyen 95 especies adicionales. Basados

  19. The complete nucleotide sequence of the coffee (Coffea arabica L.) chloroplast genome: organization and implications for biotechnology and phylogenetic relationships among angiosperms.

    Science.gov (United States)

    The chloroplast genome sequence of Coffea arabica L., first member of family Rubiaceae (fourth largest family of angiosperms) is reported. The genome is 155,189 bp in length, including a pair of inverted repeats of 25,943 bp, separated by a small single copy region of 18,137 bp and a large single co...

  20. Geranyllinalool synthases in solanaceae and other angiosperms constitute an ancient branch of diterpene synthases involved in the synthesis of defensive compounds

    NARCIS (Netherlands)

    V. Falara; J.M. Alba; M.R. Kant; R.C. Schuurink; E. Pichersky

    2014-01-01

    Many angiosperm plants, including basal dicots, eudicots, and monocots, emit (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene, which is derived from geranyllinalool, in response to biotic challenge. An Arabidopsis (Arabidopsis thaliana) geranyllinalool synthase (GLS) belonging to the e/f clade of the

  1. Measuring chlorophyll a and 14C-labeled photosynthate in aquatic angiosperms by the use of a tissue solubilizer

    International Nuclear Information System (INIS)

    A compound that quantitatively correlated with chlorophyll a could be measured fluorometrically in the extracts of leaves of three aquatic angiosperms (Myriophyllum heterophyllum Michx., Potamogeton crispus L., Elodea canadensis Michx.) treated with the tissue solubilizer BTS-450. Fluorescent characteristics of the solubilized plant tissues were stable for several weeks in the dark at temperatures up to 600C but rapidly degraded in sunlight or when acidified. 14C-Labeled photosynthate, which had been fixed by leaf discs during 1- to 10-hour exposure to H14CO3, was also readily extracted by the tissue solubilizer. Solubilizer extraction can, therefore, be use to determine both chlorophyll a content and 14C incorporation rates in the same leaf sample. The method is practical, because no grinding is required, the fluorescent characteristics of the extracts are stable, and analyses can be performed with very little plant material

  2. Measuring chlorophyll α and 14C-labeled photosynthate in aquatic angiosperms by the use of a tissue solubilizer

    International Nuclear Information System (INIS)

    A compound that quantitatively correlated with chlorophyll α could be measured fluorometrically in the extracts of leaves of three aquatic angiosperms (Myriophyllum heterophyllum Michx., Potamogeton crispus L., Elodea canadensis Michx.) treated with the tissue solubilizer BTS-450. Fluorescent characteristics of the solubilized plant tissues were stable for several weeks in the dark at temperatures up to 600C but rapidly degraded in sunlight or when acidified. 14C-Labeled photosynthate, which had been fixed by leaf discs during 1- to 10-hour exposure to H14CO3, was also readily extracted by the tissue solubilizer. Solubilizer extraction can, therefore, be used to determine both chlorophyll α content and 14C incorporation rates in the same leaf sample. The method is practical, because no grinding is required, the fluorescent characteristics of the extracts are stable, and analyses can be performed with very little plant material (about 3 milligrams)

  3. The complete chloroplast genome sequence of Citrus sinensis (L. Osbeck var 'Ridge Pineapple': organization and phylogenetic relationships to other angiosperms

    Directory of Open Access Journals (Sweden)

    Jansen Robert K

    2006-09-01

    Full Text Available Abstract Background The production of Citrus, the largest fruit crop of international economic value, has recently been imperiled due to the introduction of the bacterial disease Citrus canker. No significant improvements have been made to combat this disease by plant breeding and nuclear transgenic approaches. Chloroplast genetic engineering has a number of advantages over nuclear transformation; it not only increases transgene expression but also facilitates transgene containment, which is one of the major impediments for development of transgenic trees. We have sequenced the Citrus chloroplast genome to facilitate genetic improvement of this crop and to assess phylogenetic relationships among major lineages of angiosperms. Results The complete chloroplast genome sequence of Citrus sinensis is 160,129 bp in length, and contains 133 genes (89 protein-coding, 4 rRNAs and 30 distinct tRNAs. Genome organization is very similar to the inferred ancestral angiosperm chloroplast genome. However, in Citrus the infA gene is absent. The inverted repeat region has expanded to duplicate rps19 and the first 84 amino acids of rpl22. The rpl22 gene in the IRb region has a nonsense mutation resulting in 9 stop codons. This was confirmed by PCR amplification and sequencing using primers that flank the IR/LSC boundaries. Repeat analysis identified 29 direct and inverted repeats 30 bp or longer with a sequence identity ≥ 90%. Comparison of protein-coding sequences with expressed sequence tags revealed six putative RNA edits, five of which resulted in non-synonymous modifications in petL, psbH, ycf2 and ndhA. Phylogenetic analyses using maximum parsimony (MP and maximum likelihood (ML methods of a dataset composed of 61 protein-coding genes for 30 taxa provide strong support for the monophyly of several major clades of angiosperms, including monocots, eudicots, rosids and asterids. The MP and ML trees are incongruent in three areas: the position of Amborella and

  4. Comparative Genomics of NAC Transcriptional Factors in Angiosperms: Implications for the Adaptation and Diversification of Flowering Plants

    Science.gov (United States)

    Pereira-Santana, Alejandro; Alcaraz, Luis David; Castaño, Enrique; Sanchez-Calderon, Lenin; Sanchez-Teyer, Felipe; Rodriguez-Zapata, Luis

    2015-01-01

    NAC proteins constitute one of the largest groups of plant-specific transcription factors and are known to play essential roles in various developmental processes. They are also important in plant responses to stresses such as drought, soil salinity, cold, and heat, which adversely affect growth. The current knowledge regarding the distribution of NAC proteins in plant lineages comes from relatively small samplings from the available data. In the present study, we broadened the number of plant species containing the NAC family origin and evolution to shed new light on the evolutionary history of this family in angiosperms. A comparative genome analysis was performed on 24 land plant species, and NAC ortholog groups were identified by means of bidirectional BLAST hits. Large NAC gene families are found in those species that have experienced more whole-genome duplication events, pointing to an expansion of the NAC family with divergent functions in flowering plants. A total of 3,187 NAC transcription factors that clustered into six major groups were used in the phylogenetic analysis. Many orthologous groups were found in the monocot and eudicot lineages, but only five orthologous groups were found between P. patens and each representative taxa of flowering plants. These groups were called basal orthologous groups and likely expanded into more recent taxa to cope with their environmental needs. This analysis on the angiosperm NAC family represents an effort to grasp the evolutionary and functional diversity within this gene family while providing a basis for further functional research on vascular plant gene families. PMID:26569117

  5. Expansion and diversification of BTL ring-H2 ubiquitin ligases in angiosperms: putative Rabring7/BCA2 orthologs.

    Science.gov (United States)

    Aguilar-Hernández, Victor; Medina, Juliana; Aguilar-Henonin, Laura; Guzmán, Plinio

    2013-01-01

    RING finger E3 ligases are components of the ubiquitin proteasome system (UPS) that mediate the transfer of ubiquitin to substrates. Single-subunit RING finger E3s binds the E2 ubiquitin-conjugating enzyme and contains recognition sequences for the substrate within the same polypeptide. Here we describe the characterization of a class of RING finger E3 ligases that is conserved among eukaryotes. This class encodes a RING-H2 domain related in sequence to the ATL RING-H2 domain, another class of E3 ligases, and a C2/C2 zing finger at the amino-terminus, formerly described as BZF. In viridiplantae (green algae and land plants), we designed this family as BTL for BZF ATLs. BTLs are putative orthologs of the mammalian Rabring7/BCA2 RING-H2 E3s that have expanded in angiosperms. They are found in numbers ranging from three to thirty-one, which is in contrast to the one to three members normally found in animals, fungi, and protists. Furthermore, the number of sequence LOGOs generated in angiosperms is four times greater than that in other eukaryotes. In contrast to ATLs, which show expansion by tandem duplication, tandemly duplicated BTLs are scarce. The mode of action of Rabring7/BCA2 and BTLs may be similar since both the Rabring7/BCA2 BZF and the ath|BTL4 BZF are likely to mediate the binding of ubiquitin. This study introduces valuable information on the evolution and domain structure of the Rabring7/BCA2/BTL class of E3 ligases which may be important for core eukaryotic genes. PMID:23951330

  6. Scaling of stomatal size and density optimizes allocation of leaf epidermal space for gas exchange in angiosperms

    Science.gov (United States)

    de Boer, Hugo Jan; Price, Charles A.; Wagner-Cremer, Friederike; Dekker, Stefan C.; Franks, Peter J.; Veneklaas, Erik J.

    2015-04-01

    Stomata on plant leaves are key traits in the regulation of terrestrial fluxes of water and carbon. The basic morphology of stomata consists of a diffusion pore and two guard cells that regulate the exchange of CO2 and water vapour between the leaf interior and the atmosphere. This morphology is common to nearly all land plants, yet stomatal size (defined as the area of the guard cell pair) and stomatal density (the number of stomata per unit area) range over three orders of magnitude across species. Evolution of stomatal sizes and densities is driven by selection pressure on the anatomical maximum stomatal conductance (gsmax), which determines the operational range of leaf gas exchange. Despite the importance of stomata traits for regulating leaf gas exchange, a quantitative understanding of the relation between adaptation of gsmax and the underlying co-evolution of stomatal sizes and densities is still lacking. Here we develop a theoretical framework for a scaling relationship between stomatal sizes and densities within the constraints set by the allocation of epidermal space and stomatal gas exchange. Our theory predicts an optimal scaling relationship that maximizes gsmax and minimizes epidermal space allocation to stomata. We test whether stomatal sizes and densities reflect this optimal scaling with a global compilation of stomatal trait data on 923 species reflecting most major clades. Our results show optimal scaling between stomatal sizes and densities across all species in the compiled data set. Our results also show optimal stomatal scaling across angiosperm species, but not across gymnosperm and fern species. We propose that the evolutionary flexibility of angiosperms to adjust stomatal sizes underlies their optimal allocation of leaf epidermal space to gas exchange.

  7. Angiosperms Are Unique among Land Plant Lineages in the Occurrence of Key Genes in the RNA-Directed DNA Methylation (RdDM) Pathway.

    Science.gov (United States)

    Ma, Lu; Hatlen, Andrea; Kelly, Laura J; Becher, Hannes; Wang, Wencai; Kovarik, Ales; Leitch, Ilia J; Leitch, Andrew R

    2015-09-01

    The RNA-directed DNA methylation (RdDM) pathway can be divided into three phases: 1) small interfering RNA biogenesis, 2) de novo methylation, and 3) chromatin modification. To determine the degree of conservation of this pathway we searched for key genes among land plants. We used OrthoMCL and the OrthoMCL Viridiplantae database to analyze proteomes of species in bryophytes, lycophytes, monilophytes, gymnosperms, and angiosperms. We also analyzed small RNA size categories and, in two gymnosperms, cytosine methylation in ribosomal DNA. Six proteins were restricted to angiosperms, these being NRPD4/NRPE4, RDM1, DMS3 (defective in meristem silencing 3), SHH1 (SAWADEE homeodomain homolog 1), KTF1, and SUVR2, although we failed to find the latter three proteins in Fritillaria persica, a species with a giant genome. Small RNAs of 24 nt in length were abundant only in angiosperms. Phylogenetic analyses of Dicer-like (DCL) proteins showed that DCL2 was restricted to seed plants, although it was absent in Gnetum gnemon and Welwitschia mirabilis. The data suggest that phases (1) and (2) of the RdDM pathway, described for model angiosperms, evolved with angiosperms. The absence of some features of RdDM in F. persica may be associated with its large genome. Phase (3) is probably the most conserved part of the pathway across land plants. DCL2, involved in virus defense and interaction with the canonical RdDM pathway to facilitate methylation of CHH, is absent outside seed plants. Its absence in G. gnemon, and W. mirabilis coupled with distinctive patterns of CHH methylation, suggest a secondary loss of DCL2 following the divergence of Gnetales. PMID:26338185

  8. Divergent expression patterns of miR164 and CUP-SHAPED COTYLEDON genes in palms and other monocots : implication for the evolution of meristem function in angiosperms

    OpenAIRE

    Adam, Hélène; Marguerettaz, M.; Qadri, R.; Adroher, B.; Richaud, F; Collin, Myriam; Thuillet, Anne-Céline; Vigouroux, Yves; Laufs, P.; Tregear, James; Jouannic, Stefan

    2011-01-01

    In order to understand how the morphology of plant species has diversified over time, it is necessary to decipher how the underlying developmental programs have evolved. The regulatory network controlling shoot meristem activity is likely to have played an important role in morphological diversification and useful insights can be gained by comparing monocots and eudicots. These two distinct monophyletic groups of angiosperms diverged 130 Ma and are characterized by important differences in th...

  9. Patterns of ROS Accumulation in the Stigmas of Angiosperms and Visions into Their Multi-Functionality in Plant Reproduction.

    Science.gov (United States)

    Zafra, Adoración; Rejón, Juan D; Hiscock, Simon J; Alché, Juan de Dios

    2016-01-01

    Accumulation of reactive oxygen species (ROS) in the stigma of several plant species has been investigated. Four developmental stages (unopened flower buds, recently opened flowers, dehiscent anthers, and flowers after fertilization) were analyzed by confocal laser scanning microscopy using the ROS-specific probe DCFH2-DA. In all plants scrutinized, the presence of ROS in the stigmas was detected at higher levels during those developmental phases considered "receptive" to pollen interaction. In addition, these molecules were also present at early (unopened flower) or later (post-fertilization) stages, by following differential patterns depending on the different species. The biological significance of the presence ROS may differ between these stages, including defense functions, signaling and senescence. Pollen-stigma signaling is likely involved in the different mechanisms of self-incompatibility in these plants. The study also register a general decrease in the presence of ROS in the stigmas upon pollination, when NO is supposedly produced in an active manner by pollen grains. Finally, the distribution of ROS in primitive Angiosperms of the genus Magnolia was determined. The production of such chemical species in these plants was several orders of magnitude higher than in the remaining species evoking a massive displacement toward the defense function. This might indicate that signaling functions of ROS/NO in the stigma evolved later, as fine tune likely involved in specialized interactions like self-incompatibility. PMID:27547207

  10. Diversification rates and chromosome evolution in the most diverse angiosperm genus of the temperate zone (Carex, Cyperaceae).

    Science.gov (United States)

    Escudero, Marcial; Hipp, Andrew L; Waterway, Marcia J; Valente, Luis M

    2012-06-01

    The sedge family (Cyperaceae: Poales; ca. 5600 spp.) is a hyperdiverse cosmopolitan group with centres of species diversity in Africa, Australia, eastern Asia, North America, and the Neotropics. Carex, with ca. 40% of the species in the family, is one of the most species-rich angiosperm genera and the most diverse in temperate regions of the Northern Hemisphere, making it atypical among plants in that it inverts the latitudinal gradient of species richness. Moreover, Carex exhibits high rates of chromosome rearrangement via fission, fusion, and translocation, which distinguishes it from the rest of the Cyperaceae. Here, we use a phylogenetic framework to examine how the onset of contemporary temperate climates and the processes of chromosome evolution have influenced the diversification dynamics of Carex. We provide estimates of diversification rates and map chromosome transitions across the evolutionary history of the main four clades of Carex. We demonstrate that Carex underwent a shift in diversification rates sometime between the Late Eocene and the Oligocene, during a global cooling period, which fits with a transition in diploid chromosome number. We suggest that adaptive radiation to novel temperate climates, aided by a shift in the mode of chromosome evolution, may explain the large-scale radiation of Carex and its latitudinal pattern of species richness. PMID:22366369

  11. A gene family derived from transposable elements during early angiosperm evolution has reproductive fitness benefits in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Zoé Joly-Lopez

    2012-09-01

    Full Text Available The benefits of ever-growing numbers of sequenced eukaryotic genomes will not be fully realized until we learn to decipher vast stretches of noncoding DNA, largely composed of transposable elements. Transposable elements persist through self-replication, but some genes once encoded by transposable elements have, through a process called molecular domestication, evolved new functions that increase fitness. Although they have conferred numerous adaptations, the number of such domesticated transposable element genes remains unknown, so their evolutionary and functional impact cannot be fully assessed. Systematic searches that exploit genomic signatures of natural selection have been employed to identify potential domesticated genes, but their predictions have yet to be experimentally verified. To this end, we investigated a family of domesticated genes called MUSTANG (MUG, identified in a previous bioinformatic search of plant genomes. We show that MUG genes are functional. Mutants of Arabidopsis thaliana MUG genes yield phenotypes with severely reduced plant fitness through decreased plant size, delayed flowering, abnormal development of floral organs, and markedly reduced fertility. MUG genes are present in all flowering plants, but not in any non-flowering plant lineages, such as gymnosperms, suggesting that the molecular domestication of MUG may have been an integral part of early angiosperm evolution. This study shows that systematic searches can be successful at identifying functional genetic elements in noncoding regions and demonstrates how to combine systematic searches with reverse genetics in a fruitful way to decipher eukaryotic genomes.

  12. Moisture availability constraints on the leaf area to sapwood area ratio: analysis of measurements on Australian evergreen angiosperm trees

    Science.gov (United States)

    Togashi, Henrique; Prentice, Colin; Evans, Bradley; Forrester, David; Drake, Paul; Feikema, Paul; Brooksbank, Kim; Eamus, Derek; Taylor, Daniel

    2014-05-01

    The leaf area to sapwood area ratio (LA:SA) is a key plant trait that links photosynthesis to transpiration. Pipe model theory states that the sapwood cross-sectional area of a stem or branch at any point should scale isometrically with the area of leaves distal to that point. Optimization theory further suggests that LA:SA should decrease towards drier climates. Although acclimation of LA:SA to climate has been reported within species, much less is known about the scaling of this trait with climate among species. We compiled LA:SA measurements from 184 species of Australian evergreen angiosperm trees. The pipe model was broadly confirmed, based on measurements on branches and trunks of trees from one to 27 years old. We found considerable scatter in LA:SA among species. However quantile regression showed strong (0.2

  13. Useful ethnophytomedicinal recipes of angiosperms used against diabetes in South East Asian Countries (India, Pakistan & Sri Lanka).

    Science.gov (United States)

    Marwat, Sarfaraz Khan; Rehman, Fazalur; Khan, Ejaz Ahmad; Khakwani, Abdul Aziz; Ullah, Imdad; Khan, Kaleem Ullah; Khan, Inam Ullah

    2014-09-01

    This paper is based on data recorded from various literatures pertaining to ethnophytomedicinal recipes used against diabetes in South East Asia (India, Pakistan and Srilanka). Traditional plant treatments have been used throughout the world for the therapy of diabetes mellitus. In total 419 useful phytorecipes of 270 plant species belonging to 74 Angiospermic families were collected. From the review it was revealed that plants showing hypoglycemic potential mainly belong to the families, Cucurbitaceae (16 spp.), Euphorbiaceae (15 spp.), Caesalpiniaceae and Papilionaceae (13 spp. each), Moraceae (11 spp.), Acanthaceae (10 spp.), Mimosaceae (09 spp.), Asteraceae, Malvaceae and Poaceae (08 spp. each), Hippocrateaceae, Rutaceae and Zingiberaceae (07 spp. each), Apocynaceae, Asclepiadaceae and Verbenaceae (06 spp. each), Apiaceae, Convolvulaceae, Lamiaceae, Myrtaceae, Solanaceae (05 spp.each). The most active plants are Syzigium cumini (14 recipes), Phyllanthus emblica (09 recipes), Centella asiatica and Momordica charantia (08 recipes each), Azadirachta indica (07 recipes), Aegle marmelos, Catharanthus roseus, Ficus benghalensis, Ficus racemosa, Gymnema sylvestre (06 recipes each), Allium cepa, A. sativum, Andrographis paniculata, Curcuma longa (05 recipes each), Citrullus colocynthis, Justicia adhatoda, Nelumbo nucifera, Tinospora cordifolia, Trigonella foenum-graecum, Ziziphus mauritiana and Wattakaka volubilis (4 recipes each). These traditional recipes include extracts, leaves, powders, flour, seeds, vegetables, fruits and herbal mixtures. Data inventory consists of botanical name, recipe, vernacular name, English name. Some of the plants of the above data with experimentally confirmed antidiabetic properties have also been recorded. More investigations must be carried out to evaluate the mechanism of action of diabetic medicinal plants. Toxicity of these plants should also be explained. Scientific validation of these recipes may help in discovering new drugs from

  14. Citogenética de Angiospermas coletadas em Pernambuco: V Cytogenetics of Angiosperms collected in the State of Pernambuco: V

    Directory of Open Access Journals (Sweden)

    Andrea Pedrosa

    1999-04-01

    Full Text Available Foram analisadas 33 espécies, entre nativas e introduzidas, pertencentes a 20 famílias de angiospermas ocorrentes no Estado de Pernambuco. A caracterização cariotípica da maioria das espécies foi baseada no número e morfologia cromossômica, padrão de condensação de cromossomos profásicos e estrutura de núcleo interfásico. Cinco espécies tiveram seus números cromossômicos determinados pela primeira vez, sendo elas: Cereus jamacaru (2n=22, Clitoria fairchildiana (2n=22, Eugenia luschnathiana (2n=22, Licania tomentosa (2n=22 e Spondias tuberosa (n=16. No caso de Licania tomentosa esta é a primeira citação de número cromossômico para o gênero. Das outras 28 espécies, três (Cecropia cf. palmata, 2n=26; Crinum erubescens, 2n=70; e Schinus terebentifolius, 2n=28 apresentaram números cromossômicos diferentes dos registrados previamente na literatura.Thirty three native and introduced species from 20 families of angiosperms collected in the State of Pernambuco were analysed. The karyotype description of the majority of the species was based on chromosome number and morphology, condensation pattern of prophase chromosomes as well as interphase nuclear structure. In five species (Cereus jamacaru, 2n=22; Clitoria fairchildiana, 2n=22; Eugenia luschnathiana, 2n=22; Licania tomentosa, 2n=22; and Spondias tuberosa, n=16 the chromosome number is reported here for the first time. In the case of Licania tomentosa, this is also the first report for the genus. Among the other 28 species, three (Cecropia cf. palmata, 2n=26; Crinum erubescens, 2n=70; and Schinus terebentifolius, 2n=28 showed chromosome numbers different from what has previously been reported.

  15. The plastid genome of Najas flexilis: adaptation to submersed environments is accompanied by the complete loss of the NDH complex in an aquatic angiosperm.

    Directory of Open Access Journals (Sweden)

    Elena L Peredo

    Full Text Available The re-colonization of aquatic habitats by angiosperms has presented a difficult challenge to plants whose long evolutionary history primarily reflects adaptations to terrestrial conditions. Many aquatics must complete vital stages of their life cycle on the water surface by means of floating or emergent leaves and flowers. Only a few species, mainly within the order Alismatales, are able to complete all aspects of their life cycle including pollination, entirely underwater. Water-pollinated Alismatales include seagrasses and water nymphs (Najas, the latter being the only freshwater genus in the family Hydrocharitaceae with subsurface water-pollination. We have determined the complete nucleotide sequence of the plastid genome of Najas flexilis. The plastid genome of N. flexilis is a circular AT-rich DNA molecule of 156 kb, which displays a quadripartite structure with two inverted repeats (IR separating the large single copy (LSC from the small single copy (SSC regions. In N. flexilis, as in other Alismatales, the rps19 and trnH genes are localized in the LSC region instead of within the IR regions as in other monocots. However, the N. flexilis plastid genome presents some anomalous modifications. The size of the SSC region is only one third of that reported for closely related species. The number of genes in the plastid is considerably less. Both features are due to loss of the eleven ndh genes in the Najas flexilis plastid. In angiosperms, the absence of ndh genes has been related mainly to the loss of photosynthetic function in parasitic plants. The ndh genes encode the NAD(PH dehydrogenase complex, believed essential in terrestrial environments, where it increases photosynthetic efficiency in variable light intensities. The modified structure of the N. flexilis plastid genome suggests that adaptation to submersed environments, where light is scarce, has involved the loss of the NDH complex in at least some photosynthetic angiosperms.

  16. The plastid genome of Najas flexilis: adaptation to submersed environments is accompanied by the complete loss of the NDH complex in an aquatic angiosperm.

    Science.gov (United States)

    Peredo, Elena L; King, Ursula M; Les, Donald H

    2013-01-01

    The re-colonization of aquatic habitats by angiosperms has presented a difficult challenge to plants whose long evolutionary history primarily reflects adaptations to terrestrial conditions. Many aquatics must complete vital stages of their life cycle on the water surface by means of floating or emergent leaves and flowers. Only a few species, mainly within the order Alismatales, are able to complete all aspects of their life cycle including pollination, entirely underwater. Water-pollinated Alismatales include seagrasses and water nymphs (Najas), the latter being the only freshwater genus in the family Hydrocharitaceae with subsurface water-pollination. We have determined the complete nucleotide sequence of the plastid genome of Najas flexilis. The plastid genome of N. flexilis is a circular AT-rich DNA molecule of 156 kb, which displays a quadripartite structure with two inverted repeats (IR) separating the large single copy (LSC) from the small single copy (SSC) regions. In N. flexilis, as in other Alismatales, the rps19 and trnH genes are localized in the LSC region instead of within the IR regions as in other monocots. However, the N. flexilis plastid genome presents some anomalous modifications. The size of the SSC region is only one third of that reported for closely related species. The number of genes in the plastid is considerably less. Both features are due to loss of the eleven ndh genes in the Najas flexilis plastid. In angiosperms, the absence of ndh genes has been related mainly to the loss of photosynthetic function in parasitic plants. The ndh genes encode the NAD(P)H dehydrogenase complex, believed essential in terrestrial environments, where it increases photosynthetic efficiency in variable light intensities. The modified structure of the N. flexilis plastid genome suggests that adaptation to submersed environments, where light is scarce, has involved the loss of the NDH complex in at least some photosynthetic angiosperms. PMID:23861923

  17. Geranyllinalool synthases in solanaceae and other angiosperms constitute an ancient branch of diterpene synthases involved in the synthesis of defensive compounds

    OpenAIRE

    Falara, V.; Alba, J.M.; Kant, M.R.; Schuurink, R. C.; Pichersky, E

    2014-01-01

    Many angiosperm plants, including basal dicots, eudicots, and monocots, emit (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene, which is derived from geranyllinalool, in response to biotic challenge. An Arabidopsis (Arabidopsis thaliana) geranyllinalool synthase (GLS) belonging to the e/f clade of the terpene synthase (TPS) family and two Fabaceae GLSs that belong to the TPS-g clade have been reported, making it unclear which is the main route to geranyllinalool in plants. We characterized a to...

  18. Darwin-Wallace Demons: survival of the fastest in populations of duckweeds and the evolutionary history of an enigmatic group of angiosperms.

    Science.gov (United States)

    Kutschera, U; Niklas, K J

    2015-01-01

    In evolutionary biology, the term 'Darwinian fitness' refers to the lifetime reproductive success of an individual within a population of conspecifics. The idea of a 'Darwinian Demon' emerged from this concept and is defined here as an organism that commences reproduction almost immediately after birth, has a maximum fitness, and lives forever. It has been argued that duckweeds (sub-family Lemnoideae, order Alismatales), a group containing five genera and 34 species of small aquatic monocotyledonous plants with a reduced body plan, can be interpreted as examples of 'Darwinian Demons'. Here we focus on the species Spirodela polyrhiza (Great duckweed) and show that these miniaturised aquatic angiosperms display features that fit the definition of the hypothetical organism that we will call a 'Darwin-Wallace Demon' in recognition of the duel proponents of evolution by natural selection. A quantitative analysis (log-log bivariate plot of annual growth in dry biomass versus standing dry body mass of various green algae and land plants) revealed that duckweeds are thus far the most rapidly growing angiosperms in proportion to their body mass. In light of this finding, we discuss the disposable soma and metabolic optimising theories, summarise evidence for and against the proposition that the Lemnoideae (family Araceae) reflect an example of reductive evolution, and argue that, under real-world conditions (environmental constraints and other limitations), 'Darwin-Wallace Demons' cannot exist, although the concept remains useful in much the same way that the Hardy-Weinberg law does. PMID:24674028

  19. Influences of evergreen gymnosperm and deciduous angiosperm tree species on the functioning of temperate and boreal forests.

    Science.gov (United States)

    Augusto, Laurent; De Schrijver, An; Vesterdal, Lars; Smolander, Aino; Prescott, Cindy; Ranger, Jacques

    2015-05-01

    It has been recognized for a long time that the overstorey composition of a forest partly determines its biological and physical-chemical functioning. Here, we review evidence of the influence of evergreen gymnosperm (EG) tree species and deciduous angiosperm (DA) tree species on the water balance, physical-chemical soil properties and biogeochemical cycling of carbon and nutrients. We used scientific publications based on experimental designs where all species grew on the same parent material and initial soil, and were similar in stage of stand development, former land use and current management. We present the current state of the art, define knowledge gaps, and briefly discuss how selection of tree species can be used to mitigate pollution or enhance accumulation of stable organic carbon in the soil. The presence of EGs generally induces a lower rate of precipitation input into the soil than DAs, resulting in drier soil conditions and lower water discharge. Soil temperature is generally not different, or slightly lower, under an EG canopy compared to a DA canopy. Chemical properties, such as soil pH, can also be significantly modified by taxonomic groups of tree species. Biomass production is usually similar or lower in DA stands than in stands of EGs. Aboveground production of dead organic matter appears to be of the same order of magnitude between tree species groups growing on the same site. Some DAs induce more rapid decomposition of litter than EGs because of the chemical properties of their tissues, higher soil moisture and favourable conditions for earthworms. Forest floors consequently tend to be thicker in EG forests compared to DA forests. Many factors, such as litter lignin content, influence litter decomposition and it is difficult to identify specific litter-quality parameters that distinguish litter decomposition rates of EGs from DAs. Although it has been suggested that DAs can result in higher accumulation of soil carbon stocks, evidence from

  20. Divergent expression patterns of miR164 and CUP-SHAPED COTYLEDON genes in palms and other monocots: implication for the evolution of meristem function in angiosperms.

    Science.gov (United States)

    Adam, Hélène; Marguerettaz, Mélanie; Qadri, Rashad; Adroher, Bernard; Richaud, Frédérique; Collin, Myriam; Thuillet, Anne-Céline; Vigouroux, Yves; Laufs, Patrick; Tregear, James W; Jouannic, Stefan

    2011-04-01

    In order to understand how the morphology of plant species has diversified over time, it is necessary to decipher how the underlying developmental programs have evolved. The regulatory network controlling shoot meristem activity is likely to have played an important role in morphological diversification and useful insights can be gained by comparing monocots and eudicots. These two distinct monophyletic groups of angiosperms diverged 130 Ma and are characterized by important differences in their morphology. Several studies of eudicot species have revealed a conserved role for NAM and CUC3 genes in meristem functioning and pattern formation through the definition of morphogenetic boundaries during development. In this study, we show that NAM- and CUC3-related genes are conserved in palms and grasses, their diversification having predated the radiation of monocots and eudicots. Moreover, the NAM-miR164 posttranscriptional regulatory module is also conserved in palm species. However, in contrast to the CUC3-related genes, which share a similar expression pattern between the two angiosperm groups, the expression domain of the NAM-miR164 module differs between monocot and eudicot species. In our studies of spatial expression patterns, we compared existing eudicot data with novel results from our work using two palm species (date palm and oil palm) and two members of the Poaceae (rice and millet). In addition to contrasting results obtained at the gene expression level, major differences were also observed between eudicot and monocot NAM-related genes in the occurrence of putative cis-regulatory elements in their promoter sequences. Overall, our results suggest that although NAM- and CUC3-related proteins are functionally equivalent between monocots and eudicots, evolutionary radiation has resulted in heterotopy through alterations in the expression domain of the NAM-miR164 regulatory module. PMID:21135149

  1. Both water source and atmospheric water impact leaf wax n-alkane 2H/1H values of hydroponically grown angiosperm trees

    Science.gov (United States)

    Tipple, B. J.; Berke, M. A.; Hambach, B.; Roden, J. S.; Ehleringer, J. R.

    2013-12-01

    The extent to which both water source and leaf water 2H-enrichment affect the δ2H values of terrestrial plant leaf waxes is an area of active research as ecologists seek a mechanistic understanding of the environmental determinants of leaf wax isotope values before applying δ2H values of leaf waxes to reconstruct past hydrologic conditions. To elucidate the effects of both water source and atmospheric water vapor on δ2H values of leaf waxes for broad-leaved angiosperms, we analyzed hydrogen isotope ratios of high-molecular weight n-alkanes from two tree species that were grown throughout the spring and summer (five months) in a hydroponic system under controlled atmospheric conditions. Here, 12 subpopulations each of Populus fremontii and Betula occidentalis saplings were grown under one of six source different waters ranging in hydrogen isotope ratio values from -120 to +180 ‰ and under either 40 % or 75 % relative humidity conditions. We found n-alkane δ2H values of both species were linearly related to source water δ2H values with differences in slope associated with differing atmospheric humidity. A Craig-Gordon model was used to predict the δ2H values of leaf water and, by extension, n-alkane δ2H values under the range of growth conditions. The modeled leaf water values were found to be linearly related to observed n-alkane δ2H values with a statistically indistinguishable slope between the high and low humidity treatments. These leaf wax observations support a constant biosynthetic fractionation factor between evaporatively-enriched leaf water and n-alkanes for each species. However, we found the calculated biosynthetic fractionation between modeled leaf-water and n-alkane to be different between the two species. We submit that these dissimilarities were due to model inputs and not differences in the specific-species biochemistry. Nonetheless, these results are significant as they indicated that the δ2H value of atmospheric water vapor and

  2. The phylogeny of C/S1 bZIP transcription factors reveals a shared algal ancestry and the pre-angiosperm translational regulation of S1 transcripts.

    Science.gov (United States)

    Peviani, Alessia; Lastdrager, Jeroen; Hanson, Johannes; Snel, Berend

    2016-01-01

    Basic leucine zippers (bZIPs) form a large plant transcription factor family. C and S1 bZIP groups can heterodimerize, fulfilling crucial roles in seed development and stress response. S1 sequences also harbor a unique regulatory mechanism, termed Sucrose-Induced Repression of Translation (SIRT). The conservation of both C/S1 bZIP interactions and SIRT remains poorly characterized in non-model species, leaving their evolutionary origin uncertain and limiting crop research. In this work, we explored recently published plant sequencing data to establish a detailed phylogeny of C and S1 bZIPs, investigating their intertwined role in plant evolution, and the origin of SIRT. Our analyses clarified C and S1 bZIP orthology relationships in angiosperms, and identified S1 sequences in gymnosperms. We experimentally showed that the gymnosperm orthologs are regulated by SIRT, tracing back the origin of this unique regulatory mechanism to the ancestor of seed plants. Additionally, we discovered an earlier S ortholog in the charophyte algae Klebsormidium flaccidum, together with a C ortholog. This suggests that C and S groups originated by duplication from a single algal proto-C/S ancestor. Based on our observations, we propose a model wherein the C/S1 bZIP dimer network evolved in seed plants from pre-existing C/S bZIP interactions. PMID:27457880

  3. Contradiction between plastid gene transcription and function due to complex posttranscriptional splicing: an exemplary study of ycf15 function and evolution in angiosperms.

    Directory of Open Access Journals (Sweden)

    Chao Shi

    Full Text Available Plant chloroplast genes are usually co-transcribed while its posttranscriptional splicing is fairly complex and remains largely unsolved. On basis of sequencing the three complete Camellia (Theaceae chloroplast genomes for the first time, we comprehensively analyzed the evolutionary patterns of ycf15, a plastid gene quite paradoxical in terms of its function and evolution, along the inferred angiosperm phylogeny. Although many species in separate lineages including the three species reported here contained an intact ycf15 gene in their chloroplast genomes, the phylogenetic mixture of both intact and obviously disabled ycf15 genes imply that they are all non-functional. Both intracellular gene transfer (IGT and horizontal gene transfer (HGT failed to explain such distributional anomalies. While, transcriptome analyses revealed that ycf15 was transcribed as precursor polycistronic transcript which contained ycf2, ycf15 and antisense trnL-CAA. The transcriptome assembly was surprisingly found to cover near the complete Camellia chloroplast genome. Many non-coding regions including pseudogenes were mapped by multiple transcripts, indicating the generality of pseudogene transcriptions. Our results suggest that plastid DNA posttranscriptional splicing may involve complex cleavage of non-functional genes.

  4. New Distribution Record of Angiosperm in Fujian Province (IV)%福建被子植物分布新记录 IV

    Institute of Scientific and Technical Information of China (English)

    杨成梓; 刘小芬; 黄泽豪; 范世明; 吴锦忠

    2012-01-01

      According to the investigation on the vegetation in Fujian Province, 1 newly recorded genus, Arabis; and 5 newly recorded species, Arabis flagellosa, Sedum emarginatum, Sedum polytrichoides, Sedum tetractinum, Hylotelephium erythrostictum of angiosperms were reported. The voucher specimens were deposited in the Herbarium of FJTCM.%  在福建省药用植物资源调查中,陆续发现了福建省被子植物地理新分布记录属及种多个,经整理鉴定,本文继续报道1个新分布记录属(南芥属 Arabis)和5个新分布记录种(匍匐南芥 Arabis flagellosa、凹叶景天Sedum emarginatum、藓状景天 Sedum polytrichoides、四芒景天 Sedum tetractinum、八宝 Hylotelephium erythrostictum)。标本存放于福建中医药大学药用植物标本室。

  5. Plant functional types are more efficient than climate in predicting spectrums of trait variation in evergreen angiosperm trees of tropical Australia and China

    Science.gov (United States)

    Togashi, H. F.; Prentice, I. C. C.; Atkin, O. K.; Bloomfield, K. J.; Bradford, M.; Weerasinghe, L. K.; Harrison, S. P.; Evans, B. J.; Liddell, M. J.; Wang, H.; Cao, K. F.; Fan, Z.

    2015-12-01

    The representation of Plant Functional Types (PFTs) in current generation of Dynamic Global Vegetation Models (DGVMs) is excessively simplistically. Key ecophysiological properties, such as photosynthesis biochemistry, are most times merely averaged and trade-off with other plant traits is often neglected. Validation of a PFT framework based in photosynthetic process is crucial to improve reliability of DGVMs. We present 431 leaf-biochemical and wood level measurements in evergreen angiosperm trees of tropical forests in Australia and China that were divided in four spectrums of plant trait variation: metabolic, structural, hydraulic and height dimensions. Plant traits divided in each of these dimensions adopt survival strategies reflected more clearly by trade-off within each spectrum, and in some extent across spectrums. Co-ordination theory (that Rubisco- and electron-transport limited rates of photosynthesis are co-limiting) and least-coast theory (that intercellular to ambient CO2 concentration minimizes the combined costs per unit carbon assimilation, regulating maximum height and wood density) expectations matched PFT (which takes in account canopy position and light access, and life spam) variation. Our findings suggest that climate (air moisture, air temperature, light) has lower power representing these dimensions, in comparison to the PFT framework.

  6. New Distribution Record of Angiosperm in Fujian Province (Ⅲ)%福建被子植物分布新记录Ⅲ

    Institute of Scientific and Technical Information of China (English)

    杨成梓; 刘小芬; 黄泽豪; 范世明; 吴锦忠

    2012-01-01

      在福建省药用植物资源调查中,陆续发现了福建省被子植物地理新分布记录属及种多个,经整理鉴定,本文继续报道新分布记录属4个,乳豆属 Galactia、米口袋属 Gueldenstaedtia、山靛属 Mercurialis、刺芹属Eryngium,以及乳豆 Galactia tenuiflora、少花米口袋 Gueldenstaedtia verna、山靛 Mercurialis leiocarpa、刺芹Eryngium foetidum、泡果苘 Herissantia crispa 等5个新分布记录种,标本存放于福建中医药大学药用植物标本室%  According to the investigation on the vegetation in Fujian Province, 4 Newly recorded genera, Galactia, Gueldenstaedtia, Mercurialis, Eryngium, and 5 newly recorded species, Galactia tenuiflora, Gueldenstaedtia verna, Mercurialis leiocarpa, Herissantia crispa, Eryngium foetidum of Angiosperm were found. The voucher specimens were deposited in the Herbarium of FJTCM.

  7. De novo assembly of the carrot mitochondrial genome using next generation sequencing of whole genomic DNA provides first evidence of DNA transfer into an angiosperm plastid genome

    Directory of Open Access Journals (Sweden)

    Iorizzo Massimo

    2012-05-01

    Full Text Available Abstract Background Sequence analysis of organelle genomes has revealed important aspects of plant cell evolution. The scope of this study was to develop an approach for de novo assembly of the carrot mitochondrial genome using next generation sequence data from total genomic DNA. Results Sequencing data from a carrot 454 whole genome library were used to develop a de novo assembly of the mitochondrial genome. Development of a new bioinformatic tool allowed visualizing contig connections and elucidation of the de novo assembly. Southern hybridization demonstrated recombination across two large repeats. Genome annotation allowed identification of 44 protein coding genes, three rRNA and 17 tRNA. Identification of the plastid genome sequence allowed organelle genome comparison. Mitochondrial intergenic sequence analysis allowed detection of a fragment of DNA specific to the carrot plastid genome. PCR amplification and sequence analysis across different Apiaceae species revealed consistent conservation of this fragment in the mitochondrial genomes and an insertion in Daucus plastid genomes, giving evidence of a mitochondrial to plastid transfer of DNA. Sequence similarity with a retrotransposon element suggests a possibility that a transposon-like event transferred this sequence into the plastid genome. Conclusions This study confirmed that whole genome sequencing is a practical approach for de novo assembly of higher plant mitochondrial genomes. In addition, a new aspect of intercompartmental genome interaction was reported providing the first evidence for DNA transfer into an angiosperm plastid genome. The approach used here could be used more broadly to sequence and assemble mitochondrial genomes of diverse species. This information will allow us to better understand intercompartmental interactions and cell evolution.

  8. The role of O2 as an electron acceptor alternative to CO2 in photosynthesis of the common marine angiosperm Zostera marina L.

    Science.gov (United States)

    Buapet, Pimchanok; Björk, Mats

    2016-07-01

    This study investigates the role of O2 as an electron acceptor alternative to CO2 in photosynthesis of the common marine angiosperm Zostera marina L. Electron transport rates (ETRs) and non-photochemical quenching (NPQ) of Z. marina were measured under saturating irradiance in synthetic seawater containing 2.2 mM DIC and no DIC with different O2 levels (air-equilibrated levels, 3 % of air equilibrium and restored air-equilibrated levels). Lowering O2 did not affect ETR when DIC was provided, while it caused a decrease in ETR and an increase in NPQ in DIC-free media, indicating that O2 acted as an alternative electron acceptor under low DIC. The ETR and NPQ as a function of irradiance were subsequently assessed in synthetic seawater containing (1) 2.2 mM DIC, air-equilibrated O2; (2) saturating CO2, no O2; and (3) no DIC, air-equilibrated O2. These treatments were combined with glycolaldehyde pre-incubation. Glycolaldehyde caused a marked decrease in ETR in DIC-free medium, indicating significant electron flow supported by photorespiration. Combining glycolaldehyde with O2 depletion completely suppressed ETR suggesting the operation of the Mehler reaction, a possibility supported by the photosynthesis-dependent superoxide production. However, no notable effect of suppressing the Mehler reaction on NPQ was observed. It is concluded that during DIC-limiting conditions, such as those frequently occurring in the habitats of Z. marina, captured light energy exceeds what is utilised for the assimilation of available carbon, and photorespiration is a major alternative electron acceptor, while the contribution of the Mehler reaction is minor. PMID:27125819

  9. Sequencing of the needle transcriptome from Norway spruce (Picea abies Karst L. reveals lower substitution rates, but similar selective constraints in gymnosperms and angiosperms

    Directory of Open Access Journals (Sweden)

    Chen Jun

    2012-11-01

    09and 1.1 × 10−09 is an order of magnitude smaller than values reported for angiosperm herbs. However, if one takes generation time into account, most of this difference disappears. The estimates of the dN/dS ratio (non-synonymous over synonymous divergence reported here are in general much lower than 1 and only a few genes showed a ratio larger than 1.

  10. Megastigmus seed chalcids (Hymenoptera, Torymidae) radiated much more on Angiosperms than previously considered. I- Description of 8 new species from Kenya, with a key to the females of Eastern and Southern Africa

    Science.gov (United States)

    Roques, Alain; Copeland, Robert S.; Soldati, Laurent; Denux, Olivier; Auger-Rozenberg, Marie-Anne

    2016-01-01

    Abstract A survey of seed chalcids from woody plants in Kenya revealed 12 species belonging to the genus Megastigmus Dalman, 1820, and has increased to 16 the number of Megastigmus species presently recorded from the Afrotropical Region, of which at least 13 are seed feeders. A key to female Megastigmus of the Afrotropical Region is provided. Eight new species are described from morphological evidence: Megastigmus lanneae Roques & Copeland, Megastigmus laventhali Roques & Copeland, Megastigmus ozoroae Roques & Copeland, and Megastigmus smithi Roques & Copeland in seeds of species of the family Anacardiaceae, Megastigmus copelandi Roques & Copeland and Megastigmus grewianae Roques & Copeland in seeds of Malvaceae, Megastigmus helinae Roques & Copeland in seeds of Rhamnaceae, and Megastigmus icipeensis Roques & Copeland for which no host is known. These collections include the first records of Malvaceae and Rhamnaceae as hosts of Megastigmus seed chalcids, which appear to have radiated in Angiosperms much more than previously considered. Analyses of the mitochondrial (cytochrome oxidase subunit one – COI) and nuclear DNA (28S ribosomal region) could be carried out on 8 of the 16 African species of which 5 were newly described ones. The species associated with Anacardiaceae always clustered together in phylogenies, confirming the existence of a strong and ancestral monophyletic clade, unlike the ones associated with Malvaceae and Rhamnaceae, whose position remains unclear. All holotypes are deposited in the National Museums of Kenya. PMID:27199604

  11. A copal-8-ol diphosphate synthase from the angiosperm Cistus creticus subsp. creticus is a putative key enzyme for the formation of pharmacologically active, oxygen-containing labdane-type diterpenes.

    Science.gov (United States)

    Falara, Vasiliki; Pichersky, Eran; Kanellis, Angelos K

    2010-09-01

    The resin of Cistus creticus subsp. creticus, a plant native to Crete, is rich in labdane-type diterpenes with significant antimicrobial and cytotoxic activities. The full-length cDNA of a putative diterpene synthase was isolated from a C. creticus trichome cDNA library. The deduced amino acid sequence of this protein is highly similar (59%-70% identical) to type B diterpene synthases from other angiosperm species that catalyze a protonation-initiated cyclization. The affinity-purified recombinant Escherichia coli-expressed protein used geranylgeranyl diphosphate as substrate and catalyzed the formation of copal-8-ol diphosphate. This diterpene synthase, therefore, was named CcCLS (for C. creticus copal-8-ol diphosphate synthase). Copal-8-ol diphosphate is likely to be an intermediate in the biosynthesis of the oxygen-containing labdane-type diterpenes that are abundant in the resin of this plant. RNA gel-blot analysis revealed that CcCLS is preferentially expressed in the trichomes, with higher transcript levels found in glands on young leaves than on fully expanded leaves, while CcCLS transcript levels increased after mechanical wounding. Chemical analyses revealed that labdane-type diterpene production followed a similar pattern, with higher concentrations in trichomes of young leaves and increased accumulation upon wounding. PMID:20595348

  12. CHS基因起源初探及其在被子植物中的进化分析%A Preliminary Study on the Origin and Evolution of Chalcone Synthase (CHS) Gene in Angiosperms

    Institute of Scientific and Technical Information of China (English)

    黄金霞; 瞿礼嘉; 杨继; 银好; 顾红雅

    2004-01-01

    nudum (L.) Griseb. and Equisetum arvense L., as outgroups, the phylogenetic trees of about 250 CHSs from 29 families of angiosperm plants were constructed by using the neighbour-joining (NJ), maximum parsimony (MP) and quartet puzzle (QP)methods. The results showed that the CHSs from most plant families were separated into two or more clades while sequences from the families Brassicaceae, Fabaceae and Poaceae were each grouped into an independent monophyletic clade. The relative base substitution rates were estimated for CHS genes in three plant families, Solanaceae, Convolvulaceae, and Asteraceae, where the heterogeneity rate was detected both within and among the families. Results indicated that CHS genes in angiosperm plants were greatly diverse in terms of copy number, base substitution rate, and duplication/deletion events, which might be correlated with the diversity of life history, habitat, floral characters, and defense system of angiosperm plants.

  13. Cucumber: a model angiosperm for mitochondrial transformation?

    Science.gov (United States)

    Havey, Michael J; Lilly, Jason W; Bohanec, Borut; Bartoszewski, Grzegorz; Malepszy, Stefan

    2002-01-01

    Plants possess three major genomes, carried in the chloroplast, mitochondrion, and nucleus. The chloroplast genomes of higher plants tend to be of similar sizes and structure. In contrast both the nuclear and mitochondrial genomes show great size differences, even among closely related species. The largest plant mitochondrial genomes exist in the genus Cucumis at 1500 to 2300 kilobases, over 100 times the sizes of the yeast or human mitochondrial genomes. Biochemical and molecular analyses have established that the huge Cucumis mitochondrial genomes are due to extensive duplication of short repetitive DNA motifs. The organellar genomes of almost all organisms are maternally transmitted and few methods exist to manipulate these important genomes. Although chloroplast transformation has been achieved, no routine method exists to transform the mitochondrial genome of higher plants. A mitochondrial-transformation system for a higher plant would allow geneticists to use reverse genetics to study mitochondrial gene expression and to establish the efficacy of engineered mitochondrial genes for the genetic improvement of the mitochondrial genome. Cucumber possesses three unique attributes that make it a potential model system for mitochondrial transformation of a higher plant. Firstly, its mitochondria show paternal transmission. Secondly, microspores possess relatively few, huge mitochondria. Finally, there exists in cucumber unique mitochondrial mutations conditioning strongly mosaic (msc) phenotypes. The msc phenotypes appear after regeneration of plants from cell culture and sort with specific rearranged and deleted regions in the mitochondrial genome. These mitochondrial deletions may be a useful genetic tool to develop selectable markers for mitochondrial transformation of higher plants. PMID:12084966

  14. Molecular diversity of phospholipase D in angiosperms

    Directory of Open Access Journals (Sweden)

    Cvrčková Fatima

    2002-02-01

    Full Text Available Abstract Background The phospholipase D (PLD family has been identified in plants by recent molecular studies, fostered by the emerging importance of plant PLDs in stress physiology and signal transduction. However, the presence of multiple isoforms limits the power of conventional biochemical and pharmacological approaches, and calls for a wider application of genetic methodology. Results Taking advantage of sequence data available in public databases, we attempted to provide a prerequisite for such an approach. We made a complete inventory of the Arabidopsis thaliana PLD family, which was found to comprise 12 distinct genes. The current nomenclature of Arabidopsis PLDs was refined and expanded to include five newly described genes. To assess the degree of plant PLD diversity beyond Arabidopsis we explored data from rice (including the genome draft by Monsanto as well as cDNA and EST sequences from several other plants. Our analysis revealed two major PLD subfamilies in plants. The first, designated C2-PLD, is characterised by presence of the C2 domain and comprises previously known plant PLDs as well as new isoforms with possibly unusual features-catalytically inactive or independent on Ca2+. The second subfamily (denoted PXPH-PLD is novel in plants but is related to animal and fungal enzymes possessing the PX and PH domains. Conclusions The evolutionary dynamics, and inter-specific diversity, of plant PLDs inferred from our phylogenetic analysis, call for more plant species to be employed in PLD research. This will enable us to obtain generally valid conclusions.

  15. Grãos de pólen de angiospermas do Holoceno (7908±30 anos AP-atual da Planície Costeira sul-catarinense, Brasil Catalogue of angiosperm pollen from Holocene sediments of the Coastal Plain, Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Rodrigues Cancelli

    2012-12-01

    Full Text Available Este trabalho apresenta as descrições palinotaxonômicas, a partir da análise palinológica de sedimentos de duas seções turfáceas na Planície Costeira sul do estado de Santa Catarina, nos municípios de Santa Rosa do Sul e São João do Sul. Uma amostra da porção basal dos testemunhos foi datada em (14C em 7908±33 anos AP para Santa Rosa do Sul e 7817±41 anos AP para São João do Sul, ambos referente ao Holoceno inferior. Foram descritos 62 tipos de grãos de pólen relacionados a 49 famílias de angiospermas atuais, que expressam diferentes habitats e hábitos ecológicos. O presente trabalho juntamente com a primeira parte, que trata das descrições palinotaxonômicas de fungos, criptógamas e outros palinomorfos recuperados de sedimentos, contribui com o reconhecimento da vegetação que abrigava a Planície Costeira sul-catarinense, durante o Holoceno. As análises palinotaxonômicas constituem a base das interpretações paleoambientais e paleoclimáticas neste setor da costa brasileira.This paper presents palinotaxonomic descriptions, from a pollen analysis of sediments from two cores taken from the southern Coastal Plain of Santa Catarina State (in the municipalities of Santa Rosa do Sul and São João do Sul. A basal sample from the Santa Rosa do Sul and São João do Sul had a 14C age of 7908±33 and 7817±41 yr BP for the Lower Holocene, respectively. Sixty-two types of pollen grains were described from 49 angiosperm families, which are associated with different habitats and ecological habits. This work is published in association with Part I, which comprises palinotaxonomic descriptions of fungi, cryptogams and other palynomorphs recovered from the sediments, and contributes to the identification of vegetation that occurred on the Coastal Plain of southern Santa Catarina during the Holocene. Palinotaxonomic analyses form the basis of paleoclimatic and paleoenvironmental interpretations in this region of the Brazilian

  16. Meiotic studies in some selected angiosperms from the Kashmir Himalayas

    Institute of Scientific and Technical Information of China (English)

    Syed Mudassir JEELANI; Santosh KUMARI; Raghbir Chand GUPTA

    2012-01-01

    As a part of our program to explore and evaluate genetic diversity of flowering plants of the Kashmir Himalayas,meiotic studies have been carried out on 150 wild species.Of these,Caltha alba (2n =32),Delphinium roylei (2n =16),D.uncinatum (2n =16),Ranunculus palmatifidus (2n =28),and Sedum heterodontum (2n =14) have been cytologically worked out for the first time.New intraspecific diploid or polyploid cytotypes have been recorded for Alchemilla vulgaris (2n =34,96),Arabis amplexicaulis (2n =16),Impatiens amphorata (2n =14),Ⅰ.racemosa (2n =12),Ⅰ.sutcata (2n =16,12),Meconopsis latifolia (2n =14),Potentilla supina (2n =14),Saxifraga cernua (2n =16),Sium latijugam (2n =24),and Vicatia coniifolia (2n =44).Four species,Arabidopsis thaliana (2n =10),Berberis vulgaris (2n =28),Potentilla nubicola (2n =14),and P.sericea (2n =28),have been cytologically reported for the first time from India.A large number of meiotic abnormalities have been observed in most of these species,leading to a reduction in pollen fertility and production of heterogeneous-sized pollen grains.

  17. CUTICULAR STRUCTURE OF TWO ANGIOSPERM FOSSILS IN NEOGENE FROM TENGCHONG, YUNNAN PROVINCE AND ITS PALAEOENVIRONMENTAL SIGNIFICANCE%云南腾冲新近纪两种被子植物化石的角质层构造及其古环境意义

    Institute of Scientific and Technical Information of China (English)

    孙柏年; 丛培允; 阎德飞; 解三平

    2003-01-01

    This paper emphatically describes the cuticular characteristics of two fossil angiosperm species Betula mioluminifera Hu et Chaney and Carpinus subcordata Nathorst collected from Neogene in Tengchong, Yunnan. The cuticular characteristics of their Nearest Living Relative species (NLR species), Betula luminifera Winkler and Carpinus cordata B1.var. mollis Cheng et Chen, are analysed. In this experiment, we have got the lower epidermis of C.subcordata, whose characteristics are described as follows: Only the middle and lower parts of leave preserved; length about 7.5 cm, width 5 cm. Midrib strong; angle between ventricumbent and midrib 40°-50°; nearer to the base, bigger the angle; venulose, more than 12 pairs. Upper epidermis a little thicker and net-veined, stomata not found; epidermic cells arrayed rotundly, polygonal, length and width 20-30 μm; length of the net about 350 μm, width about 200 μm; width of nervecourses 50 μm with 3-4 rows of parallel cells; cells in nervecourses oblong, length about 2-3 times of width. Lower epidermis thin with stomata; trichome found; arrangement of epidermic cells as the same of upper epidermis. Distribution of stomata ruleless; type of stomatal apparatus Anomocytic; stomata slightly sunken; guard cells kidney-shaped and slightly lower than surrounding cells; inner surface of guard cells thick; guard cell surrounded by several epidermic cells. The cuticle, with its stomatal pores, represents the interface between plants and atmosphere, and its features such as cuticle thickness, stomatal density (SD), stomatal index (SI) and stomatal ratio (SR) are well used as a palaeoenvironmental indicator. Therefore, we can analyse changes in palaeoenvironment by studying the stomatal parameter of fossil plants which are sensitive to the change in atmospheric CO2 concentration. In this experiment, we have got the stomatal parameter of C.subcordata which indicates that atmospheric CO2 concentration in Neogene was higher than that of

  18. Drug: D06749 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D06749 Crude, Drug Nuphar rhizome (JP16); Nuphar rhizome (TN) Nupharidine [CPD:C174...63], Nupharamine [CPD:C17464], Deoxynupharidine [CPD:C09945], Tannin, Nuphamine, Anhydronuphamine, Dehydrode...amily) Nuphar rhizome Major component: Nupharidine [CPD:C17463] Therapeutic category of dr...ugs in Japan [BR:br08301] 5 Crude drugs and Chinese medicine formulations 51 Crude drugs 510 Crude drugs 5100 Crude dr...ugs D06749 Nuphar rhizome (JP16) Traditional Chinese Medicine in Japan [BR:br08304] Crude Drugs Dr

  19. Notes on genus Eurydoxa Filipjev (Lepidoptera: Tortricidae) in China

    Institute of Scientific and Technical Information of China (English)

    BYUN Bong-Kyu; YAN Shan-chun; LI Cheng-de

    2003-01-01

    Genus Eurydoxa Filipjev in China is reviewed and noted for the first time. Based on the present study, two species are recognized, including rhodopa Diakonoff and advena Filipjev. All available information for the species is reviewed and provided.

  20. The role of ABC genes in shaping perianth phenotype in the basal angiosperm Magnolia.

    Science.gov (United States)

    Wróblewska, M; Dołzbłasz, A; Zagórska-Marek, B

    2016-03-01

    It is generally accepted that the genus Magnolia is characterised by an undifferentiated perianth, typically organised into three whorls of nearly identical tepals. In some species, however, we encountered interesting and significant perianth modifications. In Magnolia acuminata, M. liliiflora and M. stellata the perianth elements of the first whorl are visually different from the others. In M. stellata the additional, spirally arranged perianth elements are present above the first three whorls, which suggests that they have been formed within the domain of stamen primordia. In these three species, we analysed expression patterns of the key flower genes (AP1, AGL6, AP3, PI, AG) responsible for the identity of flower elements and correlated them with results of morphological and anatomical investigations. In all studied species the elements of the first whorl lacked the identity of petals (lack of AP3 and PI expression) but also that of leaves (presence of AGL6 expression), and this seems to prove their sepal character. The analysis of additional perianth elements of M. stellata, spirally arranged on the elongated floral axis, revealed overlapping and reduced activity of genes involved in specification of the identity of the perianth (AGL6) but also of generative parts (AG), even though no clear gradient of morphological changes could be observed. In conclusion, Magnolia genus is capable of forming, in some species, a perianth differentiated into a calyx (sepals) and corolla (petals). Spirally arranged, additional perianth elements of M. stellata, despite activity of AG falling basipetally, resemble petals. PMID:26359638

  1. Retention of lignin in seagrasses: angiosperms that returned to the sea

    OpenAIRE

    Klap, V.A.; Hemminga, M A; Boon, J J

    2000-01-01

    Using Curie-point Pyrolysis Gas Chromatography Mass Spectrometry (Py-GCMS) and Direct Temperature-resolved Mass Spectrometry (DT-MS), lignin was detected in highly purified preparations (Milled Wood Lignin = MWL) of various tissues of the seagrasses Zostera marina and Posidonia oceanica. The results indicate that P. oceanica contains more lignin than Z. marina and that roots and rhizomes generally contain more lignin than leaves. It is concluded that the ability to produce lignin is not lost ...

  2. Dynamics of early embryo development in reference to endosperm and embryo types in angiosperms

    Directory of Open Access Journals (Sweden)

    Olga Erdelska

    2014-02-01

    Full Text Available The mitotic cycle of the endosperm cells is relatively short in the firsit phases of the postfertilization development. The endosperm type does not significantly influence the duration of the mitotic cycle; it might, however, influence the dynamics of zygote and embryo development. The quick development and early end of cellular endosperm proliferation is connected with the fact that it is, in most cases, bound to small, "spare" or "saving" tenuinucellate and unitegmic ovules. Structural differences in the behaviour of the endosperm of different types, in the phase of globular and early heart embryo, might point to differences in the time or way of transition of the embryo from suspensorial to surface nutrition.

  3. WHOLE-PLANT GROWTH STAGE ONTOLOGY FOR ANGIOSPERMS AND ITS APPLICATION IN PLANT BIOLOGY

    Science.gov (United States)

    Plant growth stages are identified as distinct morphological landmarks in a continuous developmental process. The terms describing these developmental stages record the morphological appearance of the plant at a specific point in its life cycle. The widely differing morphology of plant species conse...

  4. Theoretical and experimental determination of phloem translocation speeds in gymnosperm and angiosperm trees

    DEFF Research Database (Denmark)

    Liesche, Johannes; Jensen, K.; Minchin, P.; Bohr, Tomas; Schulz, Alexander

    2013-01-01

    In trees, carbohydrates produced in photosynthesizing leaves are transported to roots and other sink organs over distances of up to 100 m inside a specialized transport tissue, the phloem. Carbohydrate translocation in the phloem is a fundamental aspect of tree physiology with relevance for tree...... crop performance and climate change. In this paper, we present theoretical and experimental data on the carbohydrate transport speed inside the phloem....

  5. Effect of SO/sub 2/ on stomatal aperture and sulfur uptake of woody angiosperm seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Noland, T.L.; Kozlowski, T.T.

    1979-01-01

    Effects of SO/sub 2/ pollution on stomatal aperture and sulfur uptake varied with SO/sub 2/ dosage and plant species. Fumigation of Ulmus americana L. seedlings with 1 ppm SO/sub 2/ for 8 h inhibited stomatal closure and fumigation with 2 ppm SO/sub 2/ for 12 h induced stomatal closure. Sulfur uptake of fumigated Ulmus americana seedlings depended on stomatal aperture and was much higher in the light than in the dark. Fumigation of water-stressed Ginkgo biloba L. seedlings with 2 ppm SO/sub 2/ for 6.5 h tended to prevent stomatal closure. However, the effects of SO/sub 2/ on stomatal aperture were modulated and often overridden by environmental stresses such as low light intensity and drought.

  6. Interspecific differences in the effects of sulfur dioxide on angiosperm sexual reproduction

    International Nuclear Information System (INIS)

    The major objective of this study was to test the potential direct effects of SO2 on sexual reproduction in several plant species with different reproductive structures and processes. In marked contrast to the sensitivity to SO2 reported by other investigators for pollen germination and pollen tube growth in vitro, and recorded for Lepidium virginicum in this study, 4 of 5 species tested were tolerant with respect to fruit and seed set after exposure to 0.6 ppm SO2 for 8 hours during flowering. Seed set in the one sensitive species, Geranium carolinianum, was reduced 40% from the control after exposure to SO2, but only when relative humidity (RH) was at or above 90%. The effect of SO2 on Lepidium pollen germination in vitro was greater than the effect of SO2 on sexual reproduction in vivo. Sulfur dioxide reduced pollen germination in vitro 94% from the control. The same concentration of SO2, at 90% Rh, reduced pollen germination in vivo 50% from the control, but had no effect on seed set. Predictions of effects of SO2 on reproduction in vivo based on effects of SO2 on pollen germination and pollen tube growth in vitro are not valid

  7. Congruence of intraspecific variability in leaf traits for two co-occurring estuarine angiosperms.

    Science.gov (United States)

    Ainley, Lara B; Vergés, Adriana; Bishop, Melanie J

    2016-08-01

    Studies seeking to identify sources of variability and trade-offs in leaf traits have done so by assembling large databases of traits, across species and time points. It is unclear to what extent interspecific patterns derived in such a manner apply to intraspecific variation, particularly at regional scales, and the extent to which interspecific patterns vary temporally. We tested the hypothesis that the leaf traits of two foundation species, the mangrove Avicennia marina and the eelgrass Zostera muelleri, would display similar patterns of intraspecific variability across gradients of latitude and estuarine condition, that match previously reported interspecific patterns, and that persist through time. We found intraspecific patterns of decreasing carbon to nitrogen ratio and mechanical elasticity, and increasing nitrogen content with latitude that were consistent between the two plant species, and with previously reported interspecific patterns for other groups of species. Specific leaf area, leaf toughness and total phenolics, by contrast, displayed species-specific patterns that varied markedly through time. Relationships between estuarine condition and leaf traits were highly variable temporally, and also displayed markedly different patterns of intraspecific variability between the two species. Our study highlights the considerable within-species variation in leaf traits that should be accounted for in regional to biome scale analyses. Although some intraspecific patterns mirrored those found across species, at global scales, the considerable variability in other leaf traits between species and through time highlights the need to better understand the drivers and constraints of this intraspecific variation. PMID:27098661

  8. Acclimation to different depths by the marine angiosperm Posidonia oceanica: transcriptomic and proteomic profiles

    Directory of Open Access Journals (Sweden)

    Emanuela eDattolo

    2013-06-01

    Full Text Available For seagrasses, seasonal and daily variations in light and temperature represent the mains factors driving their distribution along the bathymetric cline. Changes in these environmental factors, due to climatic and anthropogenic effects, can compromise their survival. In a framework of conservation and restoration, it becomes crucial to improve our knowledge about the physiological plasticity of seagrass species along environmental gradients. Here, we aimed to identify differences in transcriptomic and proteomic profiles, involved in the acclimation along the depth gradient in the seagrass Posidonia oceanica, and to improve the available molecular resources in this species, which is an important requisite for the application of eco-genomic approaches. To do that, from plant growing in the shallow (-5m and a deep (-25m portions of a single meadow, (i we generated two reciprocal EST (Expressed Sequences Tags libraries using a Suppressive Subtractive Hybridization (SSH approach, to obtain depth/specific transcriptional profiles, and (ii we identified proteins differentially expressed, using the highly innovative USIS mass spectrometry methodology, coupled with 1D-SDS electrophoresis and labeling free approach. Mass spectra were searched in the open source Global Proteome Machine (GPM engine against plant databases and with the X!Tandem algorithm against a local database. Transcriptional analysis showed both quantitative and qualitative differences between depths. EST libraries had only the 3% of transcripts in common. A total of 315 peptides belonging to 64 proteins were identified by mass spectrometry. ATP synthase subunits were among the most abundant proteins in both conditions. Both approaches identified genes and proteins in pathways related to energy metabolism, transport and genetic information processing, that appear o be the most involved in depth acclimation in P. oceanica. Their putative rules in acclimation to depth were discussed.

  9. Continued expansion of the trans-Atlantic invasive marine angiosperm Halophila stipulacea in the Eastern Caribbean

    NARCIS (Netherlands)

    Willette, D.A.; Chalifour, J.; Debrot, A.O.; Engel, M.S.; Miller, J.; Oxenford, H.A.; Short, F.T.; Steiner, S.; Vedie, F.

    2014-01-01

    Halophila stipulacea (Hydrocharitaceae) is reported for the first time from Aruba, Curaçao, Grenadines (Grenada), St. Eustatius, St. John (US Virgin Islands), St. Martin (France), and St. Vincent and the Grenadines, bringing the total number of known occurrences from eastern Caribbean islands to 19.

  10. Retention of lignin in seagrasses: angiosperms that returned to the sea

    NARCIS (Netherlands)

    Klap, V.A.; Hemminga, M.A.; Boon, J.J.

    2000-01-01

    Using Curie-point Pyrolysis Gas Chromatography Mass Spectrometry (Py-GCMS) and Direct Temperature-resolved Mass Spectrometry (DT-MS), lignin was detected in highly purified preparations (Milled Wood Lignin = MWL) of various tissues of the seagrasses Zostera marina and Posidonia oceanica. The results

  11. Linkage of 35S and 5S rRNA genes in Artemisia (family Asteraceae): first evidence from angiosperms

    Czech Academy of Sciences Publication Activity Database

    Garcia, S.; Lim, K.Y.; Chester, M.; Garnatje, T.; Pellicer, J.; Valles, J.; Leitch, A.R.; Kovařík, Aleš

    online, - (2008), s. 1-13. ISSN 0009-5915 R&D Projects: GA ČR(CZ) GA521/07/0116 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : organization of rDNA unit * intergenic spacer * Artemisia Subject RIV: BO - Biophysics Impact factor: 5.111, year: 2008

  12. PHYSCOMITRELLA PATENS ARABINOGALACTAN PROTEINS CONTAIN ABUNDANT TERMINAL 3-O-METHYL-L-RHAMMOSYL RESIDUES NOT FOUND IN ANGIOSPERMS

    Science.gov (United States)

    A biochemical investigation of arabinogalactan proteins (AGPs) in Physcomitrella patens was undertaken with particular emphasis on the glycan chains. Following homogenization and differential centrifugation of moss gametophytes, AGPs were obtained by Arrive phenylglycoside-induced precipitation from...

  13. The latitudinal species richness gradient in New World woody angiosperms is consistent with the tropical conservatism hypothesis

    OpenAIRE

    Kerkhoff, Andrew J.; Moriarty, Pamela E.; Weiser, Michael D.

    2014-01-01

    The diversity of living things generally peaks in the tropics and declines toward the poles. This “latitudinal gradient” is Earth’s most prevalent biogeographic pattern, but biologists do not agree about its cause. Here, we use geographic and evolutionary data for over 12,500 species of woody flowering plants to test the “tropical conservatism hypothesis,” which attributes the phenomenal diversity of tropical environments to their large extent over the past 55 million years (My) and the evolu...

  14. Assessing the role of large herbivores in the structuring and functioning of freshwater and marine angiosperm ecosystems

    NARCIS (Netherlands)

    Bakker, Elisabeth S.; Pagès, Jordi F.; Arthur, Rohan; Alcoverro, Teresa

    2016-01-01

    While large herbivores can have strong impacts on terrestrial ecosystems, much less is known of their role in aquatic systems. We reviewed the literature to determine: (1) which large herbivores (>10 kg) have a (semi-)aquatic lifestyle and are important consumers of submerged vascular plants, (2) th

  15. Effectiveness of submersed angiosperm-epiphyte complexes on exchange of nutrients and organic carbon in littoral systems. I. Inorganic nutrients

    Energy Technology Data Exchange (ETDEWEB)

    Mickle, A.M.; Wetzel, R.G.

    1978-01-01

    Inorganic chemical parameters were analyzed daily for several weeks in water from an inlet stream of a small hardwater lake before and after passing through two replicated continuously, very slowly flowing (3 1/24 h) littoral systems containing natural stands of submerged Scirpus subterminalis Torr. and of Myriophyllum heterophyllum Michx. Macrophytic epiphytes were left intact. Calcium and alkalinity concentrations of the inflowing water decreased 40 to 45% in passing through the littoral systems. In both systems, pH values increased significantly, but to a greater extent in the more metabolically active Myriophyllum (than the Scirpus) littoral bed. Magnesium concentrations remained constant in passage through both systems. Sodium concentrations were unaffected by the Scirpus system but increased (8%) in the outflow from the Myriophyllum system. In contrast to the Scirpus system where potassium increased slightly, potassium concentrations decreased markedly (> 30%) in passage through the Myriophyllum complex. Nitrate-nitrogen concentrations were reduced significantly and NH/sub 4/-N decreased only slightly in both plant systems. Concentrations of NH/sub 4/-N and potassium increased markedly in inflow water after periods of rainfall. Both littoral systems were extremely effective in dampening these higher concentrations; only slight increases appeared in the outflows after passing slowly through the littoral complexes.

  16. Effectiveness of submersed angiosperm-epiphyte complexes on exchange of nutrients and organic carbon in littoral systems. I. Inorganic nutrients

    Energy Technology Data Exchange (ETDEWEB)

    Mickle, A.M.; Wetzel, R.G.

    1978-01-01

    Inorganic chemical parameters were analyzed daily for several weeks in water from an inlet stream of a small hardwater lake before and after passing through two replicated continuously, very slowly flowing (3 1/24 h) littoral systems containing natural strands of submerged Scripus subterminalis Torr. and of Myriophyllum heterophyllum Michx. Macrophytic epiphytes were left intact. Calcium and alkalinity concentrations of the inflowing water decreased 40 to 45% in passing through the littoral systems. In both systems, pH values increased significantly, but to a greater extent in the more metabolically active Myriophyllum (than the Scirpus) littoral bed. Magnesium concentrations remained constant in passage through both systems. Sodium concentrations were unaffected by the Scirpus system but increased (8%) in the outflow from the Myriophyllum system. In contrast to the Scirpus system where potassium increased slightly, potassium concentrations decreased markedly (> 30%) in passage through the Myriophyllum complex. Nitrate-nitrogen concentrations were reduced significantly and NH/sub 4/-N decreased only slightly in both plant systems. Concentrations of NH/sub 4/-N and potassium increased markedly in inflow water after periods of rainfall. Both littoral systems were extremely effective in dampening these higher concentrations; only slight increases appeared in the outflows after passing slowly through the littoral complexes.

  17. MarkerMiner 1.0: A new application for phylogenetic marker development using angiosperm transcriptomes 1

    OpenAIRE

    Chamala, Srikar; García, Nicolás; Godden, Grant T.; Krishnakumar, Vivek; Jordon-Thaden, Ingrid E.; De Smet, Riet; Berbazuk, W Brad; Douglas E Soltis; Soltis, Pamela S

    2015-01-01

    Premise of the study: Targeted sequencing using next-generation sequencing (NGS) platforms offers enormous potential for plant systematics by enabling economical acquisition of multilocus data sets that can resolve difficult phylogenetic problems. However, because discovery of single-copy nuclear (SCN) loci from NGS data requires both bioinformatics skills and access to high-performance computing resources, the application of NGS data has been limited. Methods and Results: We developed Marker...

  18. Patterns of nucleotide substitution in angiosperm cpDNA trnL (UAA)-F(GAA) regions

    NARCIS (Netherlands)

    Bakker, F.T.; Culham, A.; Gomez-Martinez, R.; Carvalho, J.; Compton, J.; Dawtrey, R.; Gibby, M.

    2000-01-01

    Patterns of substitution in chloroplast encoded trnL-F regions were compared between species of Actaea (Ranunculales), Digitalis (Scrophulariales), Drosera (Caryophyllales), Panicoideae (Poales), the small chromosome species clade of Pelargonium (Geraniales), each representing a different order of f

  19. Angiosperm flora used by meliponine guilds (Apidae, Meliponina) occurring at rainforest edges in the state of Ceará, Brazil.

    Science.gov (United States)

    Lima-Verde, Luiz W; Loiola, Maria I B; Freitas, Breno M

    2014-09-01

    Information about the use of floristic resources of the immediate edges of ombrophilous forest (Atlantic rainforest) fragments by stingless bees is not readily available in the scientific literature. Considering the importance of these plant species for local guilds of stingless bees, this study aimed to identify and characterize the flora of the immediate borders of four Atlantic rainforest fragments situated in Baturité massif, state of Ceará, used as food resource by stingless bees. We studied the growth-form of the plants, the floristic similarity between edges and the effect of rainfall on the flowering, and suggested simple techniques for handling these areas. We compiled a total of 82 plant species with a predominance of tree and shrub form. There were different floristic richness between areas and rainfall had differentiated influence on flowering, according to the edge. We concluded that the florist components of the studied edges are relevant to the stingless bee guilds, but alternative management practices are needed to conserve both plant and bee species. PMID:25004131

  20. Conserved-peptide upstream open reading frames (CPuORFs are associated with regulatory genes in angiosperms

    Directory of Open Access Journals (Sweden)

    Richard A Jorgensen

    2012-08-01

    Full Text Available Upstream open reading frames (uORFs are common in eukaryotic transcripts, but those that encode conserved peptides (CPuORFs occur in less than 1% of transcripts. The peptides encoded by three plant CPuORF families are known to control translation of the downstream ORF in response to a small signal molecule (sucrose, polyamines and phosphocholine. In flowering plants, transcription factors are statistically over-represented among genes that possess CPuORFs, and in general it appeared that many CPuORF genes also had other regulatory functions, though the significance of this suggestion was uncertain (Hayden and Jorgensen, 2007. Five years later the literature provides much more information on the functions of many CPuORF genes. Here we reassess the functions of 27 known CPuORF gene families and find that 22 of these families play a variety of different regulatory roles, from transcriptional control to protein turnover, and from small signal molecules to signal transduction kinases. Clearly then, there is indeed a strong association of CPuORFs with regulatory genes. In addition, 16 of these families play key roles in a variety of different biological processes. Most strikingly, the core sucrose response network includes three different CPuORFs, creating the potential for sophisticated balancing of the network in response to three different molecular inputs. We propose that the function of most CPuORFs is to modulate translation of a downstream major ORF (mORF in response to a signal molecule recognized by the conserved peptide and that because the mORFs of CPuORF genes generally encode regulatory proteins, many of them centrally important in the biology of plants, CPuORFs play key roles in balancing such regulatory networks.

  1. Influences of evergreen gymnosperm and deciduous angiosperm tree species on the functioning of temperate and boreal forests

    DEFF Research Database (Denmark)

    Augusto, Laurent; De Schrijver, An; Vesterdal, Lars;

    2015-01-01

    their tissues, higher soil moisture and favourable conditions for earthworms. Forest floors consequently tend to be thicker in EG forests compared to DA forests. Many factors, such as litter lignin content, influence litter decomposition and it is difficult to identify specific litter-quality parameters......, physical-chemical soil properties and biogeochemical cycling of carbon and nutrients. We used scientific publications based on experimental designs where all species grew on the same parent material and initial soil, and were similar in stage of stand development, former land use and current management. We...... present the current state of the art, define knowledge gaps, and briefly discuss how selection of tree species can be used to mitigate pollution or enhance accumulation of stable organic carbon in the soil. The presence of EGs generally induces a lower rate of precipitation input into the soil than DAs...

  2. The complete mitochondrial genome of mungbean Vigna radiata var. radiata NM92 and a phylogenetic analysis of crops in angiosperms.

    Science.gov (United States)

    Lin, Ching-Ping; Lo, Hsiao-Feng; Chen, Chien-Yu; Chen, Long-Fang Oliver

    2016-09-01

    The entire mitogenome of the Vigna radiata var. radiata NM92 was identified as a circular molecule of 401 262 bp length (DDBJ accession number: AP014716). The contents of A, T, C, and G in the NM92 mitogenome were found to be 27.48%, 27.41%, 22.63%, and 22.48%, respectively. The NM92 mitogenome encoded 3 rRNAs, 16 tRNAs and 33 proteins. Eight protein-coding genes (nad1, nad2, nad4, nad5, nad7, rps3, and rps10) centain introns. Among them, three (nad1, nad2, and nad5) are trans-spliced genes. A phylogenetic tree was reconstructed using the 21 protein-coding genes of 16 crops. A species of gymnosperms, Cycas, was selected as the outgroup. This complete mitogenome sequence provides useful information to understand the cultivation of Vigna radiata and other crops. PMID:26469726

  3. 被子植物胚柄研究进展%Research Progress in Suspensor of Angiosperms

    Institute of Scientific and Technical Information of China (English)

    宋国琦; 王兴军; 李爱芹; 李长生

    2012-01-01

    胚柄在胚胎发育过程中是一个暂时性的结构,但却起着为胚体提供营养和生长调节因子的作用.相对胚体而言,胚柄具有细胞类型单一、结构相对独立及发育时间短等特点,其在胚胎发育的基因调控和细胞命运决定研究中具有独特的优势.该文从胚柄的形成及特点、胚柄在胚胎发育中的作用、信号传递系统对胚柄的影响以及与胚柄相关基因的功能等方面进行综述,以期为研究胚柄在胚胎发育过程中所起的作用以及胚柄的命运决定提供参考信息.%The suspensor is a terminal embryonic structure that provides nutrients and growth regulators to the embryo proper during embryo development. In contrast to the embryo proper, the suspensor has a simple structure and a one-cell type that has a unique advantage in studies of gene regulation and cell fate determination. This paper presents advances in studies of suspensor formation, characteristics of the suspensor cell, genes that may be involved in suspensor development, and possible roles that suspensors play during embryogenesis.

  4. Omics and modeling approaches approaches for understanding regulation of asymmetric cell divisions in Arabidopsis and other angiosperm plants.

    NARCIS (Netherlands)

    Kajala, K.; Ramakrishna, A.; Fisher, A.; Bergmann, D.C.; Smet, De I.; Sozzani, R.; Weijers, D.; Brady, S.M.

    2014-01-01

    Background Asymmetric cell divisions are formative divisions that generate daughter cells of distinct identity. These divisions are coordinated by either extrinsic (‘niche-controlled’) or intrinsic regulatory mechanisms and are fundamentally important in plant development. Scope This review describe

  5. Trifurcatia flabellata n. gen. n. sp., a putative monocotyledon angiosperm from the Lower Cretaceous Crato Formation (Brazil

    Directory of Open Access Journals (Sweden)

    B. Mohr

    2002-01-01

    Full Text Available The Lower Cretaceous Crato Formation (northeast Brazil contains plant remains, here described as Trifurcatia flabellata n. gen. and n. sp., consisting of shoot fragments with jointed trifurcate axes, each axis bearing a single amplexicaul serrate leaf at the apex. The leaves show a flabellate acrodromous to parallelodromous venation pattern, with several primary, secondary and higher order cross-veins. This very unique fossil taxon shares many characters with monocots. However, this fossil taxon exhibits additional features which point to a partly reduced, and specialized plant, which probably enabled this plant to grow in (seasonally dry, even salty environments. In der unterkretazischen Cratoformation (Nordostbrasilien sind Pflanzenfossilien erhalten, die hier als Trifurcatia flabellata n. gen. n. sp. beschrieben werden. Sie bestehen aus trifurcaten Achsen, mit einem apikalen amplexicaulen fächerförmigen serraten Blatt. Diese Blätter zeigen eine flabellate bis acrodrome-paralellodrome Aderung mit Haupt- und Nebenadern und transversale Adern 3. Ordnung. Diese Merkmale sind typisch für Monocotyledone. Allerdings weist dieses Taxon einige Merkmale auf, die weder bei rezenten noch fossilen Monocotyledonen beobachtet werden. Sie müssen als besondere Anpassungen an einen (saisonal trockenen und vielleicht übersalzenen Lebensraum dieser Pflanze interpretiert werden. doi:10.1002/mmng.20020050121

  6. Deep sequencing of the Mexican avocado transcriptome, an ancient angiosperm with a high content of fatty acids

    OpenAIRE

    Ibarra-Laclette, Enrique; Méndez-Bravo, Alfonso; Pérez-Torres, Claudia Anahí; Albert, Victor A; Mockaitis, Keithanne; Kilaru, Aruna; López-Gómez, Rodolfo; Cervantes-Luevano, Jacob Israel; Herrera-Estrella, Luis

    2015-01-01

    Background Avocado (Persea americana) is an economically important tropical fruit considered to be a good source of fatty acids. Despite its importance, the molecular and cellular characterization of biochemical and developmental processes in avocado is limited due to the lack of transcriptome and genomic information. Results The transcriptomes of seeds, roots, stems, leaves, aerial buds and flowers were determined using different sequencing platforms. Additionally, the transcriptomes of thre...

  7. The role of litter beetles as potential reservoir for Salmonella enterica and thermophilic Campylobacter spp. between broiler flocks

    DEFF Research Database (Denmark)

    Skov, M.N.; Spencer, A.G.; Hald, Birthe; Petersen, L.; Nauerby, B.; Carstensen, B.; Madsen, Mogens

    2004-01-01

    houses and was relatively abundant in most. Typhaea stercorea and Ahasverus advena were found in eight and nine houses, respectively, and were abundant in most of these. Carcinops pumilio was found in small numbers in eight houses. No other insect species was identified. These investigations have shown...

  8. Chaves para a identificação dos principais Coleoptera (Insecta) associados com produtos armazenados Keys for the identification of Coleoptera (Insecta) associated with stored products

    OpenAIRE

    Paulo Roberto Valle da Silva Pereira; Lúcia Massutti de Almeida

    2001-01-01

    An illustrated key to identify nine families of Coleoptera commonly found in stored products is presented. Keys for the identification of Anobiidae [Lasioderma serricorne (Fabricius, 1792), Stegobium paniceum (Linnaeus, 1761)], Bruchidae [Acanthoscelides obtectus (Say, 1831), Zabrotes subfasciatus (Boheman, 1833)], Curculionidae [Sitophilus oryzae (Linnaeus, 1763), S. zeamais Motschulsky, 1885], Silvanidae [Ahasverus advena (Waltl, 1832), Cathartus quadricollis (Guérin, 1892), Oryzaephilus me...

  9. The complete chloroplast genome sequence of Citrus sinensis (L.) Osbeck var 'Ridge Pineapple': organization and phylogenetic relationships to other angiosperms

    OpenAIRE

    Jansen Robert K; Lee Seung-Bum; Singh Nameirakpam D; Bausher Michael G; Daniell Henry

    2006-01-01

    Abstract Background The production of Citrus, the largest fruit crop of international economic value, has recently been imperiled due to the introduction of the bacterial disease Citrus canker. No significant improvements have been made to combat this disease by plant breeding and nuclear transgenic approaches. Chloroplast genetic engineering has a number of advantages over nuclear transformation; it not only increases transgene expression but also facilitates transgene containment, which is ...

  10. The Pollination of Trimenia moorei (Trimeniaceae): Floral Volatiles, Insect/Wind Pollen Vectors and Stigmatic Self‐incompatibility in a Basal Angiosperm

    OpenAIRE

    Bernhardt, Peter; SAGE, TAMMY; WESTON, PETER; Azuma, Hiroshi; LAM, MATHEW; Thien, Leonard B.; Bruhl,Jeremy

    2003-01-01

    Trimenia moorei (Oliv.) Philipson is an andromonoecious liane with >0·40 of the total flower buds maturing as bisexual flowers. Male and bisexual flowers are strongly scented with pollen, anther sacs and receptacle scars testing positively for volatile emissions. Scent analyses detect over 20 components. The major fatty acid derivative is 8‐heptadecene, and 2‐phenylethanol dominates the benzenoids. While hover‐flies in the genera Melangyna and Triglyphus contact the stigma with their probosce...

  11. Effectiveness of submersed angiosperm--epiphyte complexes on exchange of nutrients and organic carbon in littoral systems. II. Dissolved organic carbon

    Energy Technology Data Exchange (ETDEWEB)

    Mickle, A.M.; Wetzel, R.G.

    1978-01-01

    Dissolved organic carbon concentrations, UV absorption, and fluorescence were measured daily for several weeks in water from an inlet stream of a hardwater lake before and after passing through three continuously, very slowly flowing (31/24 h) littoral systems. System I contained a natural stand of Scirpus subterminalis Torr. and Systems II and III contained Myriophyllum heterophyllum Michx. Macrophytic epiphytes were left intact. Dissolved organic matter of inflow and outflow water from System III was fractionated into several molecular weight fractions. Dissolved organic carbon concentrations and UV absorption increased as inflow water passed through all three littoral systems. This increase consisted only of organic compounds of >1000 molecular weight. Fluorescence increased in outflow waters of Systems I and III, but consistently decreased in System II. During periods of rainfall, but not snowfall, all three parameters in inflow water increased significantly. All three littoral systems were effective in dampening these higher concentrations; only slight increases appeared in the outflows.

  12. Effectiveness of submersed angiosperm-epiphyte complexes on exchange of nutrients and organic carbon in littoral systems. III. Refractory organic carbon

    Energy Technology Data Exchange (ETDEWEB)

    Mickle, A.M.; Wetzel, R.G.

    1979-01-01

    Refractory dissolved organic compounds, consisting mainly of fulvic acids labelled with /sup 14/C of aquatic plant origin, were added to the inlet stream water of a hardwater lake and passed through two continuously, very slowly flowing (3 1/24 h) littoral systems. System I contained a natural stand of Scripus subterminalis Torr. and System II contained Myriophyllum heterophyllum Michx. Macrophytic epiphytes were left intact. Control systems, containing similar sediments without macrophytes, received identical treatments. Dissolved organic carbon (DOC), both labelled and unlabelled, of inflow and outflow water was fractionated into several molecular weight fractions; uv absorption and fluorescence of dissolved organic matter, particulate organic carbon (POC), and major cationic concentrations were also analyzed in inflowing and outflowing water. The pathways of the labelled refractory organic carbon amendments were followed in the water, the plant foliage and roots, epiphytes, and the sediments.

  13. High transcript abundance, RNA editing, and small RNAs in intergenic regions within the massive mitochondrial genome of the angiosperm Silene noctiflora

    Czech Academy of Sciences Publication Activity Database

    Wu, Z.; Stone, James D.; Štorchová, Helena; Sloan, D.B.

    2015-01-01

    Roč. 16, NOV 14 (2015), s. 938. ISSN 1471-2164 R&D Projects: GA MŠk(CZ) EE2.3.30.0048 Institutional support: RVO:61389030 Keywords : Antisense RNA * Junk DNA * mtDNA Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.986, year: 2014

  14. Progress and gaps in understanding mechanisms of ash tree resistance to emerald ash borer, a model for wood-boring insects that kill angiosperms.

    Science.gov (United States)

    Villari, Caterina; Herms, Daniel A; Whitehill, Justin G A; Cipollini, Don; Bonello, Pierluigi

    2016-01-01

    We review the literature on host resistance of ash to emerald ash borer (EAB, Agrilus planipennis), an invasive species that causes widespread mortality of ash. Manchurian ash (Fraxinus mandshurica), which coevolved with EAB, is more resistant than evolutionarily naïve North American and European congeners. Manchurian ash was less preferred for adult feeding and oviposition than susceptible hosts, more resistant to larval feeding, had higher constitutive concentrations of bark lignans, coumarins, proline, tyramine and defensive proteins, and was characterized by faster oxidation of phenolics. Consistent with EAB being a secondary colonizer of coevolved hosts, drought stress decreased the resistance of Manchurian ash, but had no effect on constitutive bark phenolics, suggesting that they do not contribute to increased susceptibility in response to drought stress. The induced resistance of North American species to EAB in response to the exogenous application of methyl jasmonate was associated with increased bark concentrations of verbascoside, lignin and/or trypsin inhibitors, which decreased larval survival and/or growth in bioassays. This finding suggests that these inherently susceptible species possess latent defenses that are not induced naturally by larval colonization, perhaps because they fail to recognize larval cues or respond quickly enough. Finally, we propose future research directions that would address some critical knowledge gaps. PMID:26268949

  15. Whole-plant capacitance, embolism resistance and slow transpiration rates all contribute to longer desiccation times in woody angiosperms from arid and wet habitats

    Science.gov (United States)

    Low water potentials in xylem can result in damaging levels of cavitation, yet little is understood about which hydraulic traits have most influence in delaying the onset of hydraulic dysfunction during periods of drought. We examined three traits contributing to longer desiccation times in excised ...

  16. Angiosperms Are Unique among Land Plant Lineages in the Occurrence of Key Genes in the RNA-Directed DNA Methylation (RdDM) Pathway

    Czech Academy of Sciences Publication Activity Database

    Ma, L.; Hatlen, A.; Kelly, L.J.; Becher, H.; Wang, W.C.; Kovařík, Aleš; Leitch, I. J.; Leitch, Andrew R.

    2015-01-01

    Roč. 7, č. 9 (2015), s. 2648-2662. ISSN 1759-6653 R&D Projects: GA ČR GBP501/12/G090 Institutional support: RVO:68081707 Keywords : chromatin modification * DNA methylation * evolution Subject RIV: BO - Biophysics Impact factor: 4.229, year: 2014

  17. Evaluation of angiosperm and fern contributions to soil organic matter using two methods of pyrolysis-gas chromatography-mass spectrometry

    Science.gov (United States)

    Plant biochemical characteristics influence decomposition rates and subsequently the biochemical composition of soil organic matter. Ferns, in particular have biochemical characteristics that could influence the stability of soil organic matter (SOM), such as high concentrations of aliphatic compou...

  18. The Classification and Functional Significance of Staminodes in Angiosperms%被子植物退化雄蕊的功能类型及其意义

    Institute of Scientific and Technical Information of China (English)

    陈珊; 任宗昕; 王红; 吴丁

    2015-01-01

    退化雄蕊是指没有花药或花药不可育的雄蕊,发现于被子植物32.5%的科以及54.4%的属中,它们在形态和生化组成上都与可育雄蕊有着显著区别.虽然丢失了产生可育花粉的能力、无法发挥雄性繁殖功能,某些退化雄蕊在进化过程中重新获得了一些有助于植物繁殖成功的新功能.本文将这些具有功能的退化雄蕊细分为8类:(1)信号型;(2)报酬型;(3)欺骗传粉型;(4)辅助传粉昆虫在花内活动;(5)辅助授粉;(6)协助花粉二次呈现;(7)保护其他花结构;(8)避免自交.退化雄蕊作为花结构的一部分,其功能集中于促进植物的繁殖成功,主要通过与传粉昆虫的相互作用来提高传粉效率.此外,某些植物的退化雄蕊也可能同时具有多种功能,并且其功能的强弱与传粉者的种类、行为、大小和频率相关.正确评估退化雄蕊对植物繁殖成功的影响,需要多学科手段来系统的研究,以便能更加深入的理解不同近缘关系的物种间退化雄蕊功能的差异,揭示退化雄蕊在被子植物系统进化中的意义.

  19. Estrutura floral das angiospermas usadas por Heliconius erato phyllis (Lepidoptera, Nymphalidae no Rio Grande do Sul, Brasil Flower structure of angiosperms used by Heliconius erato phyllis (Lepidoptera, Nymphalidae in Rio Grande do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    Claudine A. Corrêa

    Full Text Available A field survey of flowering plants used as food resource by the adults of Heliconius erato phyllis (Fabricius, 1775 was carried out in four sites located in Rio Grande do Sul state, Brazil. Samples were taken in preserved areas of the Atlantic Rain and Myrtaceae forests, an Eucalyptus plantation, and an urban park. Adult feeding frequencies on flowers were registered monthly from December 1996 to May 1997, on plants located on previously marked 200 m long transects. Flowers on which H. erato phyllis fed in the field were collected, drawn and morphometrically characterized. Feeding was registered on flowers of twenty-three species, of which seventeen are new records for H. erato in Brazil . The use of a given plant varied among localities, as a function of its corresponding abundance. The most visited flowers were those of Lantana camara L. and Stachytarpheta cayennensis (Rich. Vahl, followed by Dahliapinnata Voss in the urban site. The data suggest the existence of size and shape convergence between the proboscis and the small, tubular flowers upon which H. eratophyllis feeds. They also indicate that H. eratophyllis adults have an opportunistic nectar feeding / pollen gathering habit, using several of those flowers available in a given time and locality that fit such a morphometrical pattern. Since plant species of both primitive and derived families are used, there is no indication that phylogenetic constraints play a major role in this association, nor that color of flowers, growth pattern or size of the plants are relevant in determining their use by H. erato phyllis.

  20. Variations in the stable carbon isotope compositions of individual lipids from the leaves of modern angiosperms: implications for the study of higher land plant-derived sedimentary organic matter

    International Nuclear Information System (INIS)

    Seasonal changes in δ13C values for individual lipids from the leaves of several species of tree have been studied in order to provide essential background information for use in future investigations of the isotopic signatures of terrigenous sedimentary organic matter. The n-alkanes of Betula ermanii, Quercus castaneifolia and Fagus japonica revealed increased δ13C in autumn leaves compared with leaves sampled at the start of the growing season. Samples taken from Q. castaneifolia and F. sylvatica at monthly intervals showed gradual depletion of 13C in bulk tissues and n-alkanes through the growing season. This may be a consequence of either recycling of depleted internal carbon in order to replace weathered waxes, or increased fractionation against 13C by the enzyme ribulose 1,5-bisphosphate carboxylase in response to increasing summer temperatures. Sitosterol exhibited similar isotopic trends as the n-alkanes in F. sylvatica, but showed the opposite behaviour in Q. castaneifolia. The effect of sunlight intensity on δ13C was investigated in foliage sampled at different compass positions around two trees, Q. robur and F. sylvatica. Bulk tissue and lipids from inner shade leaves were consistently more depleted in 13C than those from the corresponding sun leaf. The leaves receiving the highest sunlight irradiance on average, i.e. southern foliage, exhibited the lowest δ13C in lipids and bulk tissues. The variability of δ13C values with irradiance level may be due to changes in photosynthetic assimilation rates and the adaptation of the leaf epidermis and stomata in response to its light environment. Lipids and bulk tissues from leaves of Quercus species were found to possess slightly more depleted δ13C values than those in Fagus species, although interspecies variability was quite large. This study has important implications for the study of terrestrially derived organic matter preserved in ancient sediments. The results demonstrate the importance of elucidating the environmental factors that influence δ13C values of individual lipids in modern leaves prior to using isotopic shifts in sedimentary and fossil lipids as indicators of palaeoenvironmental change. (author)

  1. Estimativa por infravermelho da concentração da unidade estrutural b-O-4 em ligninas de angiospermas tropicais Infrared estimates of the concentration of the b-o-4 structural unit in lignins of tropical angiosperms

    Directory of Open Access Journals (Sweden)

    Heber dos Santos Abreu

    1997-12-01

    Full Text Available Five Björkman lignins, codified as AM, LL, GG, PP and AP, were isolated from wood species of Aspidosperma macrocarpum Mart., Lophanthera lactescens Ducke, Gallesia gorazema (Vell. Miq., Peltogyne paniculata Bth. and Aspidosperma polyneuron Muell. Arg., respectively. Analyses of the lignins were carried out by Fourier transformed infrared spectroscopy using an experimental technique, Diffusely Reflected Infrared Fourier Transformed (DRIFT, admitting in the original spectra a band at 1500 cm-1 as an internal reference. Application of a deconvolution technique made possible to estimate the percentage per mol of b-O-4 unit content around 65.5% to AM, 68.0% to LL, 71.0% to GG. 73.4% to PP and 75.0% to AP, toward AM

  2. 花同源异型MADS-box基因在被子植物中的功能保守性和多样性%Functional Conservation and Diversity of Floral Homeotic MADS-box Genes in Angiosperms

    Institute of Scientific and Technical Information of China (English)

    崔荣峰; 孟征

    2007-01-01

    MADS-box基因家族成员作为转录调控因子在被子植物花发育调控中发挥关键作用.本文以模式植物拟南芥(Arabidopsis thaliana)和水稻(Oryza sativa)为例,综述了近10年来对被子植物(又称有花植物)两大主要类群--核心真双子叶植物和单子叶植物花同源异型MADS-box基因的研究成果,分析MADS-box基因在被子植物中的功能保守性和多样性,同时探讨双子叶植物花发育的ABCDE模型在多大程度上适用于单子叶植物.

  3. Sensitivity of Bacteria Isolated from Fish to Some Medicinal Plants

    OpenAIRE

    Turker, Hakan; Yıldırım, Arzu Birinci; Karakaş, Fatma Pehlivan

    2009-01-01

    Alcoholic and aqueous extracts from 22 species of herbs from Bolu (Turkey) were screened for antibacterial activity against Aeromonas hydrophila, Yersinia ruckeri, Lactococcus garvieae, Streptococcus agalactiae and Enterococcus faecalis. Extracts with various solvent of Nuphar lutea, Nymphaea alba, Stachys annua, Genista lydia, Vinca minor, Fragaria vesca, Filipendula ulmaria, Helichrysum plicatum showed the highest inhibitory activity. The ethanolic extract of V. minor and the alcoholic and ...

  4. New species of Hydrellia (Diptera: Ephydridae) from the southern United States

    OpenAIRE

    Deonier, D. L.

    2010-01-01

    Five new species of Hydrellia Robineau-Desvoidy are described from localities in Alabama, Florida, Louisiana, and Texas. H. alabamae, n. sp. was first collected on water primrose in northern Alabama and later in northern Florida on Nuphar and Nymphoides. At present, there is no indication about potential host plant species. H. naiadis, n. sp. was reared from Najas guadalupensis (Spreng) Morong in northern Florida and later collected throughout the state and also in southeastern Texas. H. apal...

  5. Ancient Polyploidy and Modern Crop Plants

    Institute of Scientific and Technical Information of China (English)

    A.H. Paterson

    2007-01-01

    @@ The growing set of fully-sequenced angiosperm genomes highlight the role of polyploidy in angiosperm evolution, and suggest that even the high level of importance we had already attributed to this mechanism was inadequate.

  6. Evolution of genetic mechanisms regulating reproductive development in plants : Characterisation of MADS-box genes active during cone development in Norway spruce

    OpenAIRE

    Sundström, Jens

    2001-01-01

    The reproductive organs of conifers and angiosperms differ in morphology in several fundamental respects. The conifer Norway spruce (Picea abies) form pollen and seed cones from separate meristems whereas angiosperms bear bipartite flowers with sepals and petals surrounding two inner whorls of stamens and carpels. Despite these differences in morphology this thesis present data to suggest that reproductive development in conifers and angiosperms is regulated by a similar molecular mechanism. ...

  7. Chaves para a identificação dos principais Coleoptera (Insecta associados com produtos armazenados Keys for the identification of Coleoptera (Insecta associated with stored products

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Valle da Silva Pereira

    2001-03-01

    Full Text Available An illustrated key to identify nine families of Coleoptera commonly found in stored products is presented. Keys for the identification of Anobiidae [Lasioderma serricorne (Fabricius, 1792, Stegobium paniceum (Linnaeus, 1761], Bruchidae [Acanthoscelides obtectus (Say, 1831, Zabrotes subfasciatus (Boheman, 1833], Curculionidae [Sitophilus oryzae (Linnaeus, 1763, S. zeamais Motschulsky, 1885], Silvanidae [Ahasverus advena (Waltl, 1832, Cathartus quadricollis (Guérin, 1892, Oryzaephilus mercator (Fauvel, 1889, O. surinamensis (Linnaeus, 1758] and Tenebrionidae [Gnathocerus cornutus (Fabricius, 1798, Tribolium castaneum (Herbst, 1797, T. confusum du Val, 1868] are also provided. These keys cover the most frequent Coleoptera found in stored products, specially grains, and are to the adult stage only. Illustrations of external morphology and general characteristics are provided for each species reported.

  8. Comparison of three trap types for monitoring insect populations in stored grains.

    Science.gov (United States)

    Weston, P A; Barney, R J

    1998-12-01

    Three trap types--probe, cone, and sticky--were used to monitor insect populations infesting shelled maize, Zea mays L., housed in galvanized steel storage bins. Sticky traps were suspended in the headspace 1 m above the grain mass, probe traps were inserted into the grain near the top and bottom of the grain mass, and cone traps were positioned at the surface of the grain mass. Although there was some overlap, each trap type was rather specific in the range of insect species trapped. Probe traps positioned near the grain surface trapped mostly Oryzaephilus surinamensis (L.), Tribolium castaneum (Herbst), and Cynaeus angustus (LeConte); whereas those positioned near the bottom of the grain mass trapped mostly Sitophilus zeamais Motschulsky. Cone traps caught mostly Typhaea stercorea (L.), Cryptolestes spp., and Ahasverus advena Waltl. Sticky traps caught primarily stored-product moths [Plodia interpunctella (Hübner) and Sitotroga cerealella (Olivier)] and A. advena. In addition to catching pest species, cone traps also caught hemipteran predators and hymenopteran parasitoids, and sticky traps caught large numbers of parasitoids. Although probe traps caught smaller numbers of several pest species than cone traps, these traps generally detected the presence of these species at the same time as cone traps, in addition to trapping other species that were not detected at all in cone traps. Therefore, a combination of sticky traps in the grain bin headspace and probe traps positioned just below the grain surface is probably most efficient for monitoring the presence of pest and beneficial insect species in grain storage. If pests cannot be eliminated from the space beneath the false floor of a grain bin, probe traps set at the bottom of the grain mass should provide the best early warning of infestation by species colonizing a grain mass by this route. PMID:9887684

  9. Grãos de pólen de angiospermas do Holoceno (7908±30 anos AP-atual) da Planície Costeira sul-catarinense, Brasil Catalogue of angiosperm pollen from Holocene sediments of the Coastal Plain, Santa Catarina, Brazil

    OpenAIRE

    Rodrigo Rodrigues Cancelli; Paulo Alves de Souza; Paulo César Pereira das Neves

    2012-01-01

    Este trabalho apresenta as descrições palinotaxonômicas, a partir da análise palinológica de sedimentos de duas seções turfáceas na Planície Costeira sul do estado de Santa Catarina, nos municípios de Santa Rosa do Sul e São João do Sul. Uma amostra da porção basal dos testemunhos foi datada em (14C) em 7908±33 anos AP para Santa Rosa do Sul e 7817±41 anos AP para São João do Sul, ambos referente ao Holoceno inferior. Foram descritos 62 tipos de grãos de pólen relacionados a 49 famílias de an...

  10. Angiospermas Trepadoras de los bosques ribereños de una sección de la cuenca baja de los ríos Cuao-Sipapo (Estado Amazonas, Venezuela) Climbing angiosperms of the riparian forest of a section of the lower basin of the rivers Cuao-Sipapo (Amazonas State, Venezuela)

    OpenAIRE

    Irene C. FEDÓN; Aníbal CASTILLOSUÁREZ

    2005-01-01

    Se presenta una lista de las especies trepadoras de los bosques ribereños de los ríos Cuao-Sipapo-Orinoco Medio. El sitio de estudio se ubica en el área de confluencia de los ríos antes mencionados, en el Municipio Autana, estado Amazonas (4°54’ y 5°3’ Lat. N, 67°34’y 67°46’ Long. O, aprox. 100-250 m snm). El clima es biestacional y la vegetación corresponde a bosques siempreverdes macrotérmicos de tierras bajas estacionalmente inundables. Se elaboraron listas y tablas resúmenes del número de...

  11. Distribution and production of submerged macrophytes in Tipper Grund (Ringkøbing Fjord, Denmark), and the impact of waterfowl grazing

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    1980-01-01

    . at intermediate depth and Potamogeton pectinatus, Myriophyllum spicatum and Ranunculus baudauti at greater depth. (2) All macrophyte species showed a unimodal peak of biomass during the summer. Angiosperms with heavy epiphytic load withered 1-2 months earlier than did angiosperms without epiphytes...

  12. Biological active anthraquinone analogs from the fungus Eurotium sp.

    Digital Repository Service at National Institute of Oceanography (India)

    Parameswaran, P.S.; Gawas, D.; Tilvi, S.; Naik, C.G.

    the leaves of the mangrove plant Porteresia coarctata (Roxb.). These compounds have previously been reported as fungal / angiosperm metabolites exhibiting anti-bacterial, anti-oxidant and cytotoxic properties. The structures of these compounds were finalized...

  13. Dynamics of callose deposition and B-1,3-glucanase expression during reproductive events in sexual and apomictic Hieracium

    NARCIS (Netherlands)

    Tucker, M.R.; Paech, N.A.; Willemse, M.T.M.; Koltunow, A.M.G.

    2001-01-01

    Callose accumulates in the walls of cells undergoing megasporogenesis during embryo sac formation in angiosperm ovules. Deficiencies in callose deposition have been observed in apomictic plants and causal linkages between altered callose deposition and apomictic initiation proposed. In apomictic Hie

  14. Dr. Zompo : an online data repository for Zostera marina and Posidonia oceanica ESTs

    NARCIS (Netherlands)

    Wissler, L.; Dattolo, E.; Moore, A. D.; Reusch, T. B. H.; Olsen, J. L.; Migliaccio, M.; Bornberg-Bauer, E.; Procaccini, G.

    2009-01-01

    As ecosystem engineers, seagrasses are angiosperms of paramount ecological importance in shallow shoreline habitats around the globe. Furthermore, the ancestors of independent seagrass lineages have secondarily returned into the sea in separate, independent evolutionary events. Thus, understanding t

  15. Functional monoecy due to delayed anther dehiscence: a novel mechanism in Pseuduvaria mulgraveana (Annonaceae)

    OpenAIRE

    Chun-Chiu Pang; Tanya Scharaschkin; Su, Yvonne C. F.; Richard M K Saunders

    2013-01-01

    Unlike most genera in the early-divergent angiosperm family Annonaceae, Pseuduvaria exhibits a diversity of floral sex expression. Most species are structurally andromonoecious (or possibly androdioecious), although the hermaphroditic flowers have been inferred to be functionally pistillate, with sterile staminodes. Pseuduvaria presents an ideal model for investigating the evolution of floral sex in early-divergent angiosperms, although detailed empirical studies are currently lacking. The ph...

  16. Self-pollination rate and floral-display size in Asclepias syriaca (Common Milkweed) with regard to floral-visitor taxa

    OpenAIRE

    Howard, Aaron F; Barrows, Edward M.

    2014-01-01

    Background Animals fertilize thousands of angiosperm species whose floral-display sizes can significantly influence pollinator behavior and plant reproductive success. Many studies have measured the interactions among pollinator behavior, floral-display size, and plant reproductive success, but few studies have been able to separate the effects of pollinator behavior and post-pollination processes on angiosperm sexual reproduction. In this study, we utilized the highly self-incompatible polli...

  17. Pollen development in Annona cherimola Mill. (Annonaceae). Implications for the evolution of aggregated pollen

    OpenAIRE

    Hormaza Jose I; Risueño Maria C; Testillano Pilar S; Lora Jorge; Herrero Maria

    2009-01-01

    Abstract Background In most flowering plants, pollen is dispersed as monads. However, aggregated pollen shedding in groups of four or more pollen grains has arisen independently several times during angiosperm evolution. The reasons behind this phenomenon are largely unknown. In this study, we followed pollen development in Annona cherimola, a basal angiosperm species that releases pollen in groups of four, to investigate how pollen ontogeny may explain the rise and establishment of this char...

  18. Transcriptional signatures of ancient floral developmental genetics in avocado (Persea americana; Lauraceae)

    OpenAIRE

    Chanderbali, André S.; Albert, Victor A; Leebens-Mack, Jim; Altman, Naomi S.; Soltis, Douglas E.; Soltis, Pamela S.

    2009-01-01

    The debate on the origin and evolution of flowers has recently entered the field of developmental genetics, with focus on the design of the ancestral floral regulatory program. Flowers can differ dramatically among angiosperm lineages, but in general, male and female reproductive organs surrounded by a sterile perianth of sepals and petals constitute the basic floral structure. However, the basal angiosperm lineages exhibit spectacular diversity in the number, arrangement, and structure of fl...

  19. The Earliest Normal Flower from Liaoning Province, China

    Institute of Scientific and Technical Information of China (English)

    Xin Wang; Shaolin Zheng

    2009-01-01

    The early evolution of angiosperms has been a focus of intensive research for more than a century. The Yixian Formation in western Liaoning yields one of the earliest angiosperm macrofloras. Despite multitudes of angiosperm fossils uncovered, Including Archaefructus and Sinocarpus, no bona fide normal flower has been dated to 125 Ma (mega-annum) or older. Here we report Callianthus dilae gen. at sp. nov. from the Yixian Formation (Early Cretaceous) in western Liaoning, China as the earliest normal flower known to date. The flower demonstrates a typical floral organization, including tepals, androecium, and gynoecium. The tepals are spatulata with parallel veins. The stamens have a slender filament, a globular anther, bristles at the anther apex, and in situ round-triangular pollen grains. The gynoecium is composed of two stylate carpels enclosed in a fleshy envelope, and develops into a "hip" when mature. Since the well-accepted history of angiosperms is not much longer than 125 Me, Callianthus together with Chaoyangia, Archaefructus and Sinocarpus from the Yixian Formation demonstrate a surprisingly high diversity of angiosperms, implying a history of angiosperms much longer than currently accepted.

  20. Evolutionary relationships of a new genus and three new species of Omomyid primates (Willwood Formation, Lower Eocene, Bighorn Basin, Wyoming)

    Science.gov (United States)

    Bown, T.M.

    1991-01-01

    Studies of new finds of omomyid primates from the lower Eocene Willwood Formation of northwest Wyoming reveal the presence of a new genus and two new species of anaptomorphines and a new species of omomyine. All were apparently short-lived immigrants into the Bighorn Basin. The new genus and speciesTatmanius szalayi is typified by a diminutive single-rooted p3 and a bilobed-rooted p4 with a crown smaller than ml. These traits were probably derived fromPseudotetonius and parallel similar conditions inTrogolemur andNannopithex. The new speciesArapahovius advena is the first occurrence ofArapahovius outside the Washakie Basin, where it appears to have also been a vagrant species.Steinius annectens, sp. nov., is larger than the olderSteinius vespertinus and strengthens the alliance between this genus and BridgerianOraorays carteri, although which species ofSteinius is closer toOmomys is not yet clear. The available evidence suggests a derivation ofOmomys (Omomyini) fromSteinius and all Washakiini from the anaptomorphineTeilhardina, which would indicate that Omomyinae were at least diphyletic. Preliminary evidence suggests that the geographic distributions of at least some Willwood omomyids correlate with paleosol distributions.

  1. Development of Polyspermic Rice Zygotes1[OPEN

    Science.gov (United States)

    2016-01-01

    Fertilization is a general feature of eukaryotic uni- and multicellular organisms to restore a diploid genome from female and male gamete haploid genomes. In most animals and fucoid algae, polyspermy block occurs at the plasmogamy step. Because the polyspermy barrier in animals and in fucoid algae is incomplete, polyspermic zygotes are generated by multiple fertilization events. However, these polyspermic zygotes with extra centrioles from multiple sperms show aberrant nuclear and cell division. In angiosperms, polyspermy block functions in the egg cell and the central cell to promote faithful double fertilization, although the mechanism of polyspermy block remains unclear. In contrast to the case in animals and fucoid algae, polyspermic zygotes formed in angiosperms are not expected to die because angiosperms lack centrosomes. However, there have been no reports on the developmental profiles of polyspermic zygotes at cellular level in angiosperms. In this study, we produced polyspermic rice zygotes by electric fusion of an egg cell with two sperm cells, and monitored their developmental profiles. Two sperm nuclei and an egg nucleus fused into a zygotic nucleus, and the triploid zygote divided into a two-celled embryo via mitotic division with a typical bipolar microtubule spindle, as observed during mitosis of a diploid zygote. The two-celled proembryos further developed and regenerated into triploid plants. These findings suggest that polyspermic plant zygotes have the potential to form triploid embryos. Polyspermy in angiosperms might be a pathway for the formation of triploid plants, which can contribute significantly to the formation of autopolyploids. PMID:26945052

  2. No evidence of general CO2 insensitivity in ferns: one stomatal control mechanism for all land plants?

    Science.gov (United States)

    Franks, Peter J; Britton-Harper, Zoe J

    2016-08-01

    Stomatal regulation of plant carbon uptake and water loss under changing environmental conditions was a crucial evolutionary step in the colonization of land by plants. There are currently two conflicting models describing the nature of stomatal regulation across terrestrial vascular plants: the first is characterized by a fundamental mechanistic similarity across all lineages, and the second is characterized by the evolution of major differences in angiosperms compared with more ancient lineages. Specifically, the second model posits that stomata of ferns lack a response to elevated atmospheric CO2 concentration (ca ) and therefore cannot regulate leaf intercellular CO2 concentration (ci ). We compared stomatal sensitivity to changes in ca in three distantly related fern species and a representative angiosperm species. Fern and angiosperm stomata responded strongly and similarly to changes in ca . As a result, ci /ca was maintained within narrow limits during ca changes. Our results challenge the model in which stomata of ferns generally lack a response to elevated ca and that angiosperms evolved new dynamic mechanisms for regulating leaf gas exchange that differ fundamentally from ferns. Instead, the results are consistent with a universal stomatal control mechanism that is fundamentally conserved across ferns and angiosperms, and therefore likely all vascular plant divisions. PMID:27214852

  3. Molecular relics from chemical evolution and the origin of life

    International Nuclear Information System (INIS)

    The main hypothesis proposed in this work intends to remove the difficulty that arises from the conjecture that the RNA world may have left molecular relics that may still be extant in the angiosperms. We discuss whether it is possible to envisage a possible evolutionary pathway of the RNA replicators spanning the vast time span separating the first appearance of the angiosperms, late in the Mesozoic era (the Lower Cretaceous), from the most likely suberas in which the RNA world may have occurred, namely the Hadean/Early Archean. In order to address this question we suggest that through horizontal gene transfer, as well as through a series of symbiosis of the precursor cell of the land plants, the genes of the replicases (RNA-directed RNA polymerases) associated with putative DNA-independent RNA replicators may have been transferred vertically, eventually becoming specific to the angiosperms. (author). Refs, 7 tabs

  4. Insect diversity in the fossil record

    Science.gov (United States)

    Labandeira, C. C.; Sepkoski, J. J. Jr; Sepkoski JJ, J. r. (Principal Investigator)

    1993-01-01

    Insects possess a surprisingly extensive fossil record. Compilation of the geochronologic ranges of insect families demonstrates that their diversity exceeds that of preserved vertebrate tetrapods through 91 percent of their evolutionary history. The great diversity of insects was achieved not by high origination rates but rather by low extinction rates comparable to the low rates of slowly evolving marine invertebrate groups. The great radiation of modern insects began 245 million years ago and was not accelerated by the expansion of angiosperms during the Cretaceous period. The basic trophic machinery of insects was in place nearly 100 million years before angiosperms appeared in the fossil record.

  5. Ethnobotanical Study of Tehsil Kabal, Swat District, KPK, Pakistan

    OpenAIRE

    Barkatullah,; Mohammad Ibrar; Imtiaz Ahmad; Niaz Ali

    2011-01-01

    A total of 140 plants have been reported ethnobotanically from Tehsil Kabal, Swat District. These include the 133 plants (95%) of angiosperms, 3 (2.14%) of gymnosperms, and 2 (1.42%) each of pteridophytes and fungi. The largest family is Lamiaceae represented by 11 species followed by Rosaceae represented by 9 species. Among angiosperms 76 (55.63%) were herbs, 17 (12.78%) were shrubs, and 40 (30.07%) were trees; 127 plants (95.48%) were dicot while 6 plants (4.51%) were monocot. Most of the p...

  6. Benthic bacterial biomass and production in the Hudson River estuary

    International Nuclear Information System (INIS)

    Bacterial biomass, production, and turnover were determined for two freshwater march sites and a site in the main river channel along the tidally influenced Hudson River. The incorporation of [methyl-3H]thymidine into DNA was used to estimate the growth rate of surface and anaerobic bacteria. Bacterial production at marsh sites was similar to, and in some cases considerably higher than, production estimates reported for other aquatic wetland and marine sediment habitats. Production averaged 1.8-2.8 mg C·m-2· hour-1 in marsh sediments. Anaerobic bacteria in marsh sediment incorporated significant amounts of [methyl-3H]thymidine into DNA. Despite differences in dominant vegatation and tidal regime, bacterial biomass was similar (1 x 103 ± 0.08 mg C·m-2) in Trapa, Typha, and Nuphar aquatic macrophyte communities. Bacterial abundance and productivity were lower in sandy sediments associated with Scirpus communities along the Hudson River (0.2 x 103 ± 0.05 mg C·m-2 and 0.3 ± 0.23 mg C · m-2· hour-1, respectively)

  7. Assessment of the Potential Biological Activity of Low Molecular Weight Metabolites of Freshwater Macrophytes with QSAR

    Science.gov (United States)

    Fedorova, Elena V.; Krylova, Julia V.

    2016-01-01

    The paper focuses on the assessment of the spectrum of biological activities (antineoplastic, anti-inflammatory, antifungal, and antibacterial) with PASS (Prediction of Activity Spectra for Substances) for the major components of three macrophytes widespread in the Holarctic species of freshwater, emergent macrophyte with floating leaves, Nuphar lutea (L.) Sm., and two species of submergent macrophyte groups, Ceratophyllum demersum L. and Potamogeton obtusifolius (Mert. et Koch), for the discovery of their ecological and pharmacological potential. The predicted probability of anti-inflammatory or antineoplastic activities above 0.8 was observed for twenty compounds. The same compounds were also characterized by high probability of antifungal and antibacterial activity. Six metabolites, namely, hexanal, pentadecanal, tetradecanoic acid, dibutyl phthalate, hexadecanoic acid, and manool, were a part of the major components of all three studied plants, indicating their high ecological significance and a certain universalism in their use by various species of water plants for the implementation of ecological and biochemical functions. This report underlines the role of identified compounds not only as important components in regulation of biochemical and metabolic pathways and processes in aquatic ecological systems, but also as potential pharmacological agents in the fight against different diseases. PMID:27200207

  8. ENVIRONMENTAL FACTORS INFLUENCING THE VEGETATION IN MIDDLE-SIZED STREAMS IN LATVIA

    Directory of Open Access Journals (Sweden)

    L. GRINBERGA

    2011-01-01

    Full Text Available In this study the species diversity and distribution of macrophytes in 131 surveyed sites of middle-sized streams of Latvia were investigated. The aim of the study was to determine the composition of macrophyte vegetation in Latvian streams in relation to the environmental factors (stream width, water depth, substrate type, shading and flow velocity. On the basis of these factors, five major groups of streams were distinguished representing mutually different typical macrophyte communities – (1 fast flowing streams on gravelly and stony substrate, (2 slow flowing streams on gravelly and stony substrate, (3 fast flowing streams on sandy substrate, (4 slow flowing streams on sandy substrate, and (5 streams with soft, silty substrate. Totally, 47 macrophyte taxa were found in the streams. The most common macrophyte species were Nuphar lutea found in 65% of all sites, followed by Sparganium emersum (64%, S. erectum s.l. (48%, Phalaris arundinacea (50%, Alisma plantago-aquatica (54% and Lemna minor (41%. The highest species richness (22 was found in slow flowing streams with gravelly substrate. Species-poor macrophyte communities were characteristic for fast flowing streams on sandy substrate.

  9. Recent and Holocene climate change controls on vegetation and carbon accumulation in Alaskan coastal muskegs

    Science.gov (United States)

    Peteet, Dorothy M.; Nichols, Jonathan E.; Moy, Christopher M.; McGeachy, Alicia; Perez, Max

    2016-01-01

    Pollen, spore, macrofossil and carbon data from a peatland near Cordova, Alaska, reveal insights into the climate-vegetation-carbon interactions from the initiation of the Holocene, c. the last 11.5 ka, to the present (1 ka = 1000 calibrated years before present where 0 = 1950 CE). The Holocene period is characterized by early deposition of gyttja in a pond environment with aquatics such as Nuphar polysepalum and Potamogeton, and a significant regional presence of Alnus crispa subsp. sinuata. Carbon accumulation (50 g/m2/a) was high for a short interval in the early Holocene when Sphagnum peat accumulated, but was followed by a major decline to 13 g/m2/a from 7 to 3.7 ka when Cyperaceae and ericads such as Rhododendron (formerly Ledum) groenlandicum expanded. This shift to sedge growth is representative of many peatlands throughout the south-central region of Alaska, and indicates a drier, more evaporative environment with a large decline in carbon storage. The subsequent return to Sphagnum peat after 4 ka in the Neoglacial represents a widespread shift to moister, cooler conditions, which favored a resurgence of ericads, such as Andromeda polifolia, and increased carbon accumulation rate. The sustained Alnus expansion visible in the top 10 cm of the peat profile is correlative with glacial retreat and warming of the region in the last century, and suggests this colonization will continue as temperature increases and ice melts.

  10. Distribution and carbon isotope patterns of diterpenoids and triterpenoids in modern temperate C3 trees and their geochemical significance

    Science.gov (United States)

    Diefendorf, Aaron F.; Freeman, Katherine H.; Wing, Scott L.

    2012-05-01

    Tricyclic diterpenoids and pentacyclic triterpenoids are nearly exclusively produced by gymnosperms and angiosperms, respectively. Even though both classes of terpenoids have long been recognized as plant biomarkers, their potential use as phylogenetically specific δ13C proxies remains largely unexplored. Little is known of how terpenoid abundance and carbon isotope composition vary either with plant phylogenetic position, functional group, or during synthesis. Here, we report terpenoid abundances and isotopic data for 44 tree species in 21 families, representing both angiosperms and gymnosperms, and both deciduous and evergreen leaf habits. Di- and triterpenoid abundances are significantly higher in evergreens compared to deciduous species, reflecting differences in growth strategies and increased chemical investment in longer-lived leaves. Carbon isotope abundances of terpenoid lipids are similar to leaf tissues, indicating biosynthetic isotope effects are small for both the MVA (-0.4‰) and MEP (-0.6‰) pathways. Leaf and molecular isotopic patterns for modern plants are consistent with observations of amber, resins and plant biomarkers in ancient sediments. The δ13C values of ancient diterpenoids are higher than triterpenoids by 2-5‰, consistent with observed isotopic differences between gymnosperms and angiosperms leaves, and support the relatively small lipid biosynthetic effects reported here. All other factors being equal, evergreen plants will dominate the abundance of terpenoids contributed to soils, sediments and ancient archives, with similar inputs estimated for angiosperm and gymnosperm trees when scaled by litter flux.

  11. Slower phloem transport in gymnosperm trees can be attributed to higher sieve element resistance

    DEFF Research Database (Denmark)

    Liesche, Johannes; Windt, Carel; Bohr, Tomas;

    2015-01-01

    In trees, carbohydrates produced in photosynthesizing leaves are transported to roots and other sink organs over distances of up to 100 m inside a specialized transport tissue, the phloem. Angiosperm and gymnosperm trees have a fundamentally different phloem anatomy with respect to cell size, sha...

  12. Integrating Studies on Plant-Pollinator and Plant-Herbivore Interactions

    NARCIS (Netherlands)

    Lucas-Barbosa, Dani

    2016-01-01

    Research on herbivore-induced plant defence and research on pollination ecology have had a long history of separation. Plant reproduction of most angiosperm species is mediated by pollinators, and the effects of herbivore-induced plant defences on pollinator behaviour have been largely neglected.

  13. Palynology of the Late Neogene, intercepted in a borehole from Cerneţi (East of Turnu Severin

    Directory of Open Access Journals (Sweden)

    Iustinian Petrescu

    2003-09-01

    Full Text Available The paper presents the results of the palynologic studies carried on the samples recovered the W1 well from Cerneţi. These rocks were assigned to Meotian and Pontian deposits. The Meotian deposits, 40 m thick are characterized by a paly-nological spectrum consisting from: Ferns (3-4%, Conifers (56-62%, Monocotyledon-ous Angiosperms (1-2%, Dicotyledonous Angiosperms (33-40%. The microflora was compared with the pollinic spectrum from the Late Meotian deposits between Teleajen and Dâmboviţa (Cioflică, 1969. The Pontian intercepted between m 112 and m 36 keeps a relatively uniform microflora: Ferns (5%, Conifers (60%, Monocotyledonous Angiosperms (1%, Dicotyledonous Angiosperms (34%. This microflora was compared with the pollinic spectrum from the Lower Pontian deposits from Batoţi and from the Upper Pontian deposits from V. Vişenilor and V. Boierească. The paper infers on paleocli-matic circumstances specific to the forest vegetation during the Meotian and Pontian times, and also contains a reconstitution of the source vegetation for the studied and identified sporo-pollinic material.

  14. Natural variation in synthesis and catabolism genes influences dhurrin content in sorghum (Sorghum bicolor L. Moench)

    Science.gov (United States)

    Cyanogenic glucosides are natural compounds found in over 1,000 species of angiosperms that produce HCN and are deemed undesirable for agricultural use. However, these compounds are important components of primary defensive mechanisms of many plant species. One of the best-studied cyanogenic glucos...

  15. Genome wide association mapping for leaf

    Science.gov (United States)

    Cyanogenic glucosides are natural compounds found in over 1,000 species of angiosperms that produce HCN and are deemed undesirable for agricultural use. However, these compounds are important components of primary defensive mechanisms of many plant species. One of the best-studied cyanogenic gluco...

  16. The resources of the wild preferential conservation plants in Chongqing%重庆市野生重点保护植物资源

    Institute of Scientific and Technical Information of China (English)

    易思荣; 黄娅

    2002-01-01

    According to primary statistics, there are 33 wild national protection plants in Chongqing, with a 60% of the total, in which 5 fern, 20 gymnosperm and 30 angiosperm. In all the protective plants, there are 14 species Ⅰ grade and 41 species Ⅱ grade. The kinds, resource situation and geographical distribution of all wild preferential conservation plants in Chongqing were emphatically investigated and analyed.

  17. Epiphytic bacterial community composition on two common submerged macrophytes in brackish water and freshwater

    OpenAIRE

    Blindow Irmgard; Blume Maja; Hempel Melanie; Gross Elisabeth M

    2008-01-01

    Abstract Background Plants and their heterotrophic bacterial biofilm communities possibly strongly interact, especially in aquatic systems. We aimed to ascertain whether different macrophytes or their habitats determine bacterial community composition. We compared the composition of epiphytic bacteria on two common aquatic macrophytes, the macroalga Chara aspera Willd. and the angiosperm Myriophyllum spicatum L., in two habitats, freshwater (Lake Constance) and brackish water (Schaproder Bodd...

  18. Plant carnivory in the Caryophyllales: phylogenetic relationships, morphological adaptations, and molecular evolution of digestive enzymes among carnivorous genera

    OpenAIRE

    Renner, Tanya

    2011-01-01

    Phylogenetic relationships among carnivorous plants of the angiosperm order Caryophyllales are explored using Bayesian statistics and maximum-likelihood based searches of phylogeny. Nuclear ribosomal (ITS) and chloroplast intergenic spacer (PY-IGS) regions, along with previously- sequenced DNA are utilized for phylogenetic reconstructions. Taxonomic relationships across genera are refined and three strongly supported clades are identified: monophyletic Droseraceae, Nepenthaceae, and a third c...

  19. Evolutionary studies of the Gnetales

    OpenAIRE

    Hou, Chen

    2016-01-01

    The Gnetales consist of three distinct genera, Ephedra, Gnetum and Welwitschia with considerable divergence among them regarding morphological, ecological and molecular characters. A longstanding debate of the similarity between the Gnetales and angiosperms and the unresolved seed plant phylogeny intrigues plant scientists to further investigate the evolutionary history of the Gnetales. The presented projects deal with interdisciplinary questions on proteomics, chloroplast genomes, phylogenet...

  20. LIGNIFICATION IN TRANSGENICS DEFICIENT IN P-COUMARATE 3-HYDROXYLASE (C3H) AND THE ASSOCIATED HYDROXYCINNAMOYL TRANSFERASE (HCT)

    Science.gov (United States)

    The effects on lignification of downregulating most of the genes for enzymes on the monolignol biosynthetic pathway have been reasonably well studied in angiosperms. The exception to this is the crucial hydroxylase, cinnamate 3-hydroxylase (C3H), and its associated hydroxycinnamyl transferase (HCT),...

  1. Mechanisms of self-incompatibility and unilateral incompatibility in diploid potato (Solanum tuberosum L.).

    NARCIS (Netherlands)

    Eijlander, R.

    1998-01-01

    In chapter 1 an overview is given of the major mechanisms operating in Angiosperms that prevent or limit the degree of inbreeding. The two major systems that function on the basis of interaction between pollen and stigma/style, are the sporophytic and the gametophytic self-incompatibility systems (S

  2. Heliotropium europaeum Poisoning in Cattle and Analysis of its Pyrrolizidine Alkaloid Profile

    NARCIS (Netherlands)

    Shimshoni, J.A.; Mulder, P.P.J.; Bouznach, A.; Edery, N.; Pasval, I.; Barel, S.; Khaliq, M.A.E.; Perl, S.

    2015-01-01

    Pyrrolizidine alkaloids (PAs) are carcinogenic and genotoxic phytochemicals found exclusively in angiosperms. The ingestion of PA-containing plants often results in acute and chronic toxicities in man and livestock, targeting mainly the liver. During February 2014, a herd of 15-18-month-old mixed-br

  3. Impact of the hydraulic capacity of plants on water and carbon fluxes in tropical South America

    Science.gov (United States)

    Lee, Jung-Eun; Boyce, Kevin

    2010-12-01

    Angiosperms (flowering plants) have higher transpirational capacities than any other plants. Here we use climate model simulation to test the hypothesis that the high transpirational capacity of angiosperms plays a unique role in the maintenance of tropical rainforest. Their elevated transpiration rates are shown to increase recycling of precipitation up to ˜300 mm/yr (˜20% of total precipitation) averaged over the whole of tropical South America and to increase the wet season duration over the Amazon basin. Transpiration triggers convection by increasing moisture in the boundary layer and thereby decreasing atmospheric stability. If the moisture content of the boundary layer is sufficient, a double Intertropical Convergence Zone (ITCZ) is generated in October around 60°W-50°W, as observed in present-day climate, and the eastern part of the Amazon basin becomes wet (˜200 mm/month of precipitation). This double ITCZ is lost, however, and the region becomes dry (<50 mm/month of precipitation) in the absence of full angiosperm transpiration. Although higher water use efficiency is usually associated with plants with lower transpiration rates, water use efficiency actually increases with higher hydraulic capacity in our simulations as a result of the higher humidity and, thus, lower vapor pressure gradient between the intercellular air space within the leaf and the external atmosphere. We speculate that the high transpirational capacity of angiosperms played a significant role in the expansion of tropical rain forest.

  4. Molecular identification of Phytoplasmas infecting diseased pine trees in the UNESCO-protected Curonian Spit of Lithuania

    Science.gov (United States)

    Although mainly known as pathogens that affect angiosperms, phytoplasmas have recently been detected in diseased coniferous plants. In 2008-2014, we observed, in the Curonian Spit of western Lithuania and in forests of southern Lithuania (Varena district), diseased trees of Scots pine (Pinus sylvest...

  5. Plant Reproduction and the Pollen Tube Journey--How the Females Lure the Males

    Science.gov (United States)

    Lorbiecke, Rene

    2012-01-01

    The growth of pollen tubes is one of the most characteristic events in angiosperm reproduction. This article describes an activity for visualizing the journey and guidance of pollen tubes in the reproductive structures of a flowering plant. The activity uses a semi-in vivo system with rapid-cycling "Brassica rapa," also known as Fast Plants.…

  6. BIOMONITORING USING AQUATIC VEGETATION

    Science.gov (United States)

    This chapter provides an overview of the state-of-the-science as related to the phytoassessment techniques used in environmental biomonitoring and the hazard assessment process for chemicals. The emphasis is on freshwater angiosperms and bryophytes. Algal species, which are prese...

  7. SABATH Methyltransferases from White Spruce (Picea glauca [Moench] Voss): Gene Cloning, Functional Characterization and Structural Analysis

    Science.gov (United States)

    Known members of the plant SABATH family of methyltransferases have important biological functions by methylating hormones, signaling molecules and other metabolites. While all previously characterized SABATH genes were isolated from angiosperms, in this article, we report on the isolation and funct...

  8. Changes in floral diversities, floral turnover rates, and climates in Campanian and Maastrichtian time, North Slope of Alaska

    Science.gov (United States)

    Frederiksen, N.O.

    1989-01-01

    One-hundred-and-ten angiosperm pollen taxa have been found in upper Campanian to Masstrichtian rocks of the Colville River region, North Slope of Alaska. These are the highest paleolatitude Campanian and Maastrichtian floras known from North America. Total angiosperm pollen diversity rose during the Campanian and declined toward the end of the Maastrichtian. However, anemophilous porate pollen of the Betulaceae-Myricaceae-Ulmaceae complex increased gradually in diversity during the late Campanian and Maastrichtian and into the Paleocene. Turnover of angiosperm taxa was active throughout most of late Campanian and Maastrichtian time; rapid turnover affected mainly the taxa of zoophilous herbs, representing an bundant but ecologically subordinate element of the vegetation. Last appearances of pollen taxa during the late Campanian and Maastrichtian probably represented mainly extinctions rather than emigrations; end- Cretaceous angiosperm extinctions in the North American Arctic began well before the Cretaceous-Tertiary boundary event. The last appearances in the late Maastrichtian took place in bursts; they appear to represent stepwise rather than gradual events, which may indicate the existence of pulses of climatic change particularly in late Maastrichtian time. ?? 1989.

  9. Main: RHERPATEXPA7 [PLACE

    Lifescience Database Archive (English)

    Full Text Available RHERPATEXPA7 S000512 04-January-2007 (last modified) kehi Right part of RHEs (Root Hair -specific ... nes from diverse angiosperm species with different hair ... distribution patterns; K=G/T; W=T/A; root; hair ; A ...

  10. IAPT/IOPB chromosome data 20 (extende on-line version)

    Czech Academy of Sciences Publication Activity Database

    Altinordu, F.; Šumberová, Kateřina; Ankova, T.; Erst, A. S.; Kuzmin, I. V.; Shaulo, D. N.; Plugatar, Y. V.; Baltisberger, M.; Deldago, L.; Gallego Martín, F.; Rico, E.; Lavia, G. I.; Krapovickas, A.; de los Angeles Martines, M.; Lazaroff, Y.; Solis Neffa, V. G.; Ortiz, A. M.; Sivestri, M. C.; Pavlova, D.; Bani, A.; Polido, C. A.; Moraes, A. P.; Forni-Martins, E. R.; Probatova, N. S.; Kazanovsky, S. G.; Barkalov, V. Y.; Rudyka, E. G.; Shatokhina, A. V.; Krivenko, D. A.; Verkhozina, A. V.; Nechaev, V. A.; Romero-da Cruz, M. V.; Wefferling, K. M.; Owen, H. A.; Hoot, S. B.

    2015-01-01

    Roč. 64, č. 6 (2015), E1-E39. ISSN 0040-0262 R&D Projects: GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : chromosome count * angiosperms * DNA -Sequences Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.299, year: 2014

  11. Low soil water and nutrient availability below New Zealand kauri ( Agathis australis (D. Don) Lindl.) trees increase the relative fitness of kauri seedlings

    NARCIS (Netherlands)

    Verkaik, E.; Berendse, F.; Gardner, R.O.

    2007-01-01

    Tree species can affect the soil they are growing on and this might influence their fitness. The New Zealand gymnosperm tree species kauri (Agathis australis (D. Don) Lindl.) which grows in mixed angiosperm¿gymnosperm forests has a substantial effect upon the soil. We studied the hypotheses that: (1

  12. Development of the trophic part of consortia’s relations of the gossamer-winged butterflies (Lepidoptera, Lycaenidae with Salvia nutans (Lamiaceae

    Directory of Open Access Journals (Sweden)

    K. K. Goloborodko

    2008-03-01

    Full Text Available On the basis of dummy individual consortia of Salvia nutans L. an important component of fertilization mechanism – the dynamics of trophic relations of antophylus agents with an entomophilous angiosperm autotroph was investigated. The dominant position in species structure of fertilizers in conditionally native steppe ecosystems is occupied by relict TomaresnogelidobrogensisCar.

  13. Mapping of Mitochondrial Sorting Locus in Cucumber

    Science.gov (United States)

    In plants, DNA is located in three different places, the chloroplast, mitochondrion, and nucleus. Most angiosperms transmitted their organellar DNA through the egg (mitochondrial DNA), and through the egg and/ or pollen (chloroplast DNA). Transmission of the organellar DNA in cucumber is unique beca...

  14. Feoforbídeo (etoxi-purpurina-18 isolado de Gossypium mustelinum (Malvaceae Ethyl ester putpurin-18 from Gossypium mustelinum (Malvaceae

    Directory of Open Access Journals (Sweden)

    Tania Maria Sarmento Silva

    2010-01-01

    Full Text Available The phaeophorbide ethyl ester named Purpurin-18 and the flavonoids quercetin and kaempferol were obtained by chromatographic procedures from the chloroform fraction of aerial parts of Gossypium mustelinum. The structure of these compound was determined by NMR, IR and mass spectra data analysis. This is the first occurrence of this compound in Angiosperm.

  15. Complex Self-Incompatibility Systems in Ranunculus acris L. and Beta vulgaris L

    DEFF Research Database (Denmark)

    Lundqvist, A.; Østerbye, U.; Larsen, K.; Linde-Laursen, Ib

    1973-01-01

    acris, and in Beta vulgaris there are at least four. The observations strongly support the theory of the incompatibility genes being ancient constituents of the breeding systems of the angiosperms. Most probably a complex type of incompatibility control was already present at the presumed common...

  16. Allelopathy of Aquatic Autotrophs

    OpenAIRE

    Gross, Elisabeth

    2003-01-01

    Allelopathy in aquatic environments may provide a competitive advantage to angiosperms, algae, or cyanobacteria in their interaction with other primary producers. Allelopathy can influence the competition between different photoautotrophs for resources and change the succession of species, for exarnple, in phytoplankton cornmunities. Field evidence and laboratory studies indicate that allelopathy occurs in all aquatic habitats (marine and freshwater), and that ail prirnary producing organisms...

  17. Teaching the Scientific Method: It's All in the Perspective

    Science.gov (United States)

    Ayers, James M.; Ayers, Kathleen M.

    2007-01-01

    A three unit module of inquiry, including morphological comparison, cladogram construction, and data mining has been developed to teach students the nature of experimental science. Students generate angiosperm morphological data, form cladistic hypotheses, then mine taxonomic, bioinformatic and historical data from many sources to replicate and…

  18. Intercellular transport of epidermis-expressed MADS domain transcription factors and their effect on plant morphology and floral transition

    NARCIS (Netherlands)

    Urbanus, S.L.; Martinelli, A.P.; Dinh, Q.D.; Aizza, L.C.B.; Dornelas, M.; Angenent, G.C.; Immink, G.H.

    2010-01-01

    During the lifetime of an angiosperm plant various important processes such as floral transition, specification of floral organ identity and floral determinacy, are controlled by members of the MADS domain transcription factor family. To investigate the possible non-cell-autonomous function of MADS

  19. The Amborella Genome and the Evolution of Flowering Plants

    DEFF Research Database (Denmark)

    Palmer, Jeffrey D.; Ammiraju, Jetty S. S.; Ralph, Paula;

    2013-01-01

    Amborella trichopoda is strongly supported as the single living species of the sister lineage to all other extant flowering plants, providing a unique reference for inferring the genome content and structure of the most recent common ancestor (MRCA) of living angiosperms. Sequencing the Amborella...

  20. Phylogenetic Analysis of the Plant-specific Zinc Finger-Homeobox and Mini Zinc Finger Gene Families

    Institute of Scientific and Technical Information of China (English)

    Wei Hu; Claude W.dePamphilis; Hong Ma

    2008-01-01

    Zinc finger-homaodomain proteins (ZHD) are present in many plants;however,the evolutionary history of the ZHD gene family remains largely unknown.We show here that ZHD genes are plant-specific,nearly all intronless,and related to MINI ZINC FINGER (MIF) genes that possess only the zinc finger.Phylogenetic analyses of ZHD genes from representative land plants suggest that non-seed plant ZHD genes occupy basal positions and angiosperm homologs form seven distinct clades.Several clades contain genes from two or more major angiosperm groups,including eudicots,monocots,magnoliids,and other basal angiosperms,indicating that several duplications occurred before the diversification of flowering plants.In addition,specific lineages have experienced more recent duplications.Unlike the ZHD genes,&fiFs are found only from seed plants,possibly derived from ZHDs by loss of the homeodomain before the divergence of seed plants.Moreover,the MIF genes have also undergone relatively recent gene duplications.Finally,genome duplication might have contributed substantially to the expansion of family size in angiosperms and caused a high level of functional redundancy/overlap in these genes.

  1. MODIFYING LIGNIN IN CONIFERS: THE ROLE OF HCT DURING TRACHEARY ELEMENT FORMATION IN PINUS RADIATA

    Science.gov (United States)

    The enzyme hydroxycinnamoyl-CoA: shikimate hydroxycinnamoyltransferase (HCT) is involved in the production of methoxylated monolignols that are precursors to guaiacyl and syringyl lignin in angiosperm species. We identified and cloned a putative HCT gene from Pinus radiata, a coniferous gymnosperm, ...

  2. Plant-derived terpenoids as paleovegetation proxies: evaluation of the proxy with Paleocene and Eocene megafloras and plant biomarkers in the Bighorn Basin, USA

    Science.gov (United States)

    Diefendorf, A. F.; Freeman, K. H.; Wing, S. L.

    2012-12-01

    Plant terpenoids (defense compounds synthesized from the 5-carbon building block isoprene) have a long history of use as geochemical plant biomarkers, and potentially can be used to reconstruct changes in the abundances of major land plant groups in rocks and sediments that do not preserve plant megafossils or pollen. Pentacyclic triterpenoids are synthesized almost exclusively by angiosperms whereas conifers produce the tricyclic diterpenoids. Many previous studies have focused on the use of di- to triterpenoid ratios to reconstruct floral changes in the geologic past, however few studies have compared terpenoid-based paleoflora proxies to pollen or megafossils. Prior reconstructions also did not take into account differences in biomarker production between plant functional types, such as deciduous and evergreen plants, which can be quite large. To investigate the use of terpenoids as paleoflora proxies, we examined sediments from the Bighorn Basin (Wyoming, USA) where ancient megafloras have been studied in detail. We analyzed di- and triterpenoid abundances as well as plant leaf waxes (n-alkanes) and other biomarkers in a total of 75 samples from 15 stratigraphic horizons from the late Paleocene (62 Ma) to early Eocene (52.5 Ma). By comparing terpenoid ratios with abundances estimated from plant megafossils, we can evaluate the utility of terpenoids as paleovegetation proxies. In nearly all samples, angiosperm triterpenoids are significantly lower in abundance than conifer diterpenoids. This contrasts with leaf fossil data that indicate paleofloras were dominated by angiosperms in both abundance and diversity. Traditional use of terpenoid paleovegetation proxies would therefore significantly overestimate the abundance of conifers, even when accounting for plant production differences. To determine if this overestimate is related to the loss of angiosperm triterpenoids (rather than enhanced production of diterpenoids in the geologic past), we compared angiosperm

  3. Complete chloroplast genome sequences of Drimys, Liriodendron, andPiper: Implications for the phylogeny of magnoliids and the evolution ofGC content

    Energy Technology Data Exchange (ETDEWEB)

    Zhengqiu, C.; Penaflor, C.; Kuehl, J.V.; Leebens-Mack, J.; Carlson, J.; dePamphilis, C.W.; Boore, J.L.; Jansen, R.K.

    2006-06-01

    The magnoliids represent the largest basal angiosperm clade with four orders, 19 families and 8,500 species. Although several recent angiosperm molecular phylogenies have supported the monophyly of magnoliids and suggested relationships among the orders, the limited number of genes examined resulted in only weak support, and these issues remain controversial. Furthermore, considerable incongruence has resulted in phylogenies supporting three different sets of relationships among magnoliids and the two large angiosperm clades, monocots and eudicots. This is one of the most important remaining issues concerning relationships among basal angiosperms. We sequenced the chloroplast genomes of three magnoliids, Drimys (Canellales), Liriodendron (Magnoliales), and Piper (Piperales), and used these data in combination with 32 other completed angiosperm chloroplast genomes to assess phylogenetic relationships among magnoliids. The Drimys and Piper chloroplast genomes are nearly identical in size at 160,606 and 160,624 bp, respectively. The genomes include a pair of inverted repeats of 26,649 bp (Drimys) and 27,039 (Piper), separated by a small single copy region of 18,621 (Drimys) and 18,878 (Piper) and a large single copy region of 88,685 bp (Drimys) and 87,666 bp (Piper). The gene order of both taxa is nearly identical to many other unrearranged angiosperm chloroplast genomes, including Calycanthus, the other published magnoliid genome. Comparisons of angiosperm chloroplast genomes indicate that GC content is not uniformly distributed across the genome. Overall GC content ranges from 34-39%, and coding regions have a substantially higher GC content than non-coding regions (both intergenic spacers and introns). Among protein-coding genes, GC content varies by codon position with 1st codon > 2nd codon > 3rd codon, and it varies by functional group with photosynthetic genes having the highest percentage and NADH genes the lowest. Across the genome, GC content is highest in

  4. Paleocene floral diversities and turnover events in eastern North America and their relation to diversity models

    Science.gov (United States)

    Frederiksen, N.O.

    1994-01-01

    This paper uses angiosperm pollen taxon turnover (first and last appearance) and diversity events as metrics to describe the Paleocene floral history of the eastern Gulf Coast; data are from 64 samples and 67 angiosperm pollen taxa. Angiosperm pollen diversity was very low at the beginning of the Paleocene, rose slowly and then somewhat more rapidly to a maximum for the epoch in the middle of the late Paleoceneas a result of the maximum in rate of first appearances during the late early Paleocene and earliest late Paleocene. Diversity then dropped very rapidly at or near the end of the epoch as the rate of last appearances reached its maximum, resulting in the Terminal Paleocene Extinction Event. The latest Paleocene diversity decline coincided with an increase in mean annual temperature and probably in rainfall, representing the beginning of the climatic maximum for the Tertiary which characterized the early Eocene. The increase in diversity of early Paleocene floras in the eastern Gulf Coast resulted from exploitation of unfilled ecospace originating from (1) low regional diversity following the Terminal Cretaceous Extinction Event, and (2) creation of many new niches during the Paleocene, resulting, according to megafloral evidence, from a change to a new vegetation type (multistratal tropical rainforest) brought about by an increase in rainfall. The slow rate of recovery of earliest Paleocene angiosperm diversity in the eastern Gulf Coast may be explained in part by the diversity-dependence model of Carr and Kitchell (1980). However, additional factors may have contributed to the slow recovery: (1) the adverse terminal Cretaceous climates may have extended into the early Paleocene, (2) the initial Paleocene environment of the eastern Gulf Coast may have contained relatively few niches, (3) some earliest Paleocene angiosperms, particularly trees, may have had inherently poor capabilities for rapid evolution, and (4) there was a lack of significant immigration of

  5. Factors Influencing the Stable Oxygen and Hydrogen Isotopic Composition (δ 18O and δ D) of a Subarctic Freshwater Lake Ecosystem

    Science.gov (United States)

    Wang, Y.; Wooller, M. J.

    2005-12-01

    Previous studies have shown that the stable oxygen and hydrogen isotopic compositions (δ 18O and δD) in various animal tissues can be used to examine past climates and animal migration pattern. Little attention has been paid to the relative roles of diet and water influencing the overall δ 18O and δD of animal tissues in freshwater ecosystems. It is unclear whether different trophic levels in a freshwater lake ecosystem have an identical relationship to the water that surrounds them. The δ18O and δD values of animal tissues may be controlled by numerous different factors, including metabolic and biosynthetic isotopic fractionation and variations of δ 18O and δD in the food available. We began to examine these issues by analyzing the δ 18O and δD throughout a freshwater aquatic ecosystem at Smith Lake in Alaska. We collected samples representing primary producers and consumers (primary and secondary). Samples included green algae, various aquatic plants, such as Nuphar variegatum (water lily), Polygonum amphibium (water smartweed), Carex utriculata (sedge), Utricularia vulgaris (common bladderwort), Typha latifolia (common cattail), and a range of aquatic invertebrates, including Chironomus. sp (midge), Zygoptera (damselfly), Anisoptera (dragonfly), Dytiscidae (diving beetle) and Euhirudinea (leeches). The δ 18O and δD of Smith Lake water were ~-13.5e and -129.0e, respectively, and we present the δ 18O and δD of the rest of the ecosystem relative to these data. For instance, the δ 18O of chironomus sp. was ~12.1, which is greater than the of the lake water. Preliminary results suggest the extent of the fractionation between δ 18O of chironomids vs. lake water δ 18O is consistent with previous studies. Our data provide an insight into the range of variations that could be expected within a single freshwater ecosystem.

  6. Simple Indolizidine and Quinolizidine Alkaloids.

    Science.gov (United States)

    Michael, Joseph P

    2016-01-01

    This review of simple indolizidine and quinolizidine alkaloids (i.e., those in which the parent bicyclic systems are in general not embedded in polycyclic arrays) is an update of the previous coverage in Volume 55 of this series (2001). The present survey covers the literature from mid-1999 to the end of 2013; and in addition to aspects of the isolation, characterization, and biological activity of the alkaloids, much emphasis is placed on their total synthesis. A brief introduction to the topic is followed by an overview of relevant alkaloids from fungal and microbial sources, among them slaframine, cyclizidine, Steptomyces metabolites, and the pantocins. The important iminosugar alkaloids lentiginosine, steviamine, swainsonine, castanospermine, and related hydroxyindolizidines are dealt with in the subsequent section. The fourth and fifth sections cover metabolites from terrestrial plants. Pertinent plant alkaloids bearing alkyl, functionalized alkyl or alkenyl substituents include dendroprimine, anibamine, simple alkaloids belonging to the genera Prosopis, Elaeocarpus, Lycopodium, and Poranthera, and bicyclic alkaloids of the lupin family. Plant alkaloids bearing aryl or heteroaryl substituents include ipalbidine and analogs, secophenanthroindolizidine and secophenanthroquinolizidine alkaloids (among them septicine, julandine, and analogs), ficuseptine, lasubines, and other simple quinolizidines of the Lythraceae, the simple furyl-substituted Nuphar alkaloids, and a mixed quinolizidine-quinazoline alkaloid. The penultimate section of the review deals with the sizable group of simple indolizidine and quinolizidine alkaloids isolated from, or detected in, ants, mites, and terrestrial amphibians, and includes an overview of the "dietary hypothesis" for the origin of the amphibian metabolites. The final section surveys relevant alkaloids from marine sources, and includes clathryimines and analogs, stellettamides, the clavepictines and pictamine, and bis

  7. Establishment and Evaluation of the Vegetative Community in A Surface Flow Constructed Wetland Treating Industrial Park Contaminants

    Directory of Open Access Journals (Sweden)

    C. C. Galbrand

    2008-01-01

    Full Text Available A surface flow constructed wetland, designed to curve in a kidney shape in order to increase the length to width ratio to 5:1 was used to treat runoff from an industrial park. A natural wetland system located approximately 200 m downstream of the constructed wetland was selected to act as the vegetative community model for the constructed wetland. The selected model was a riparian, open water marsh dominated by emergent macrophytes. Baseline plant species surveying was conducted. In total, 21 emergent wetland plant species, 40 upland vascular plant species, 17 upland shrub species and 13 upland tree species were identified in the model site. The species from the model site were screened for suitability in the constructed wetland based on the following criteria: (a phytoremediation potential (especially metal uptake, (b sedimentation and erosion control, (c habitat function, (d public deterrent potential and (e rate of plant establishment, tolerances and maintenance requirements. Transplantation was chosen as the main vegetation establishment methodology in the constructed wetland. The species woolgrass (Scirpus cyperinus and soft rush (Juncus effusus were chosen to dominate the interior berms and littoral edges of the constructed wetland cells. The buffer areas were dominated by meadowsweet (Spiraea alba var. latifolia and the open water areas were dominated by cowlily (Nuphar variegate and pickerelweed (Pontederia cordata species. A diverse, self-sustaining vegetative community was successfully established in the constructed wetland. The transplant success was gauged by mortality census in the spring of 2003. Over all, 138 dead transplants were observed, many of which had died as a direct result of washout. These computes to an overall site establish success rate of about 87.3%. The species, which suffered the highest mortality rates, were the pickerelweed, with approximately 50 dead plants, the meadowsweet with 32 observed dead plants and

  8. In vitro antibacterial and antitumor activities of some medicinal plant extracts, growing in Turkey

    Institute of Scientific and Technical Information of China (English)

    Arzu Birinci Yildirim; Fatma Pehlivan Karakas; Arzu Ucar Turker

    2013-01-01

    Objective:To investigate antibacterial and antitumor activities of 51 different extracts prepared with 3 types of solvents (water, ethanol and methanol) of 16 different plant species (Ajuga reptans (A. reptans) L., Phlomis pungens (P. pungens) Willd., Marrubium astracanicum (M. astracanicum) Jacq., Nepeta nuda (N. nuda) L., Stachys annua (S. annua) L., Genista lydia (G. lydia) Boiss., Nuphar lutea (N. lutea) L., Nymphaea alba (N. alba) L., Vinca minor (V. minor) L., Stellaria media (S. media) L., Capsella bursa-pastoris (C. bursa-pastoris) L., Galium spurium (G. spurium) L., Onosma heterophyllum (O. heterophyllum) Griseb., Reseda luteola (R. luteola) L., Viburnum lantana (V. lantana) L. and Mercurialis annua (M. annua) L.) grown in Turkey was conducted. Methods:Antibacterial activity was evaluated with 10 bacteria including Streptococcus pyogenes (S. pyogenes), Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis), Escheria coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Salmonella typhimurium (S. typhimurium), Serratia marcescens (S. marcescens), Proteus vulgaris (P. vulgaris), Enterobacter cloacae (E. cloacea), and Klebsiella pneumoniae (K. pneumoniae) by using disc diffusion method. Antitumor activity was evaluated with Agrobacterium tumefaciens (A. tumefaciens)-induced potato disc tumor assay. Results: Best antibacterial activity was obtained with ethanolic extract of P. pungens against S. pyogenes. Ethanolic and methanolic extract of N. alba and ethanolic extract of G. lydia also showed strong antibacterial activities. Results indicated that alcoholic extracts especially ethanolic extracts exhibited strong antibacterial activity against both gram-positive and gram-negative bacteria. Best antitumor activity was obtained with methanolic extracts of N. alba and V. lantana (100%tumor inhibition). Ethanolic extract of N. alba, alcoholic extracts of N. lutea, A. reptans and V. minor flowers, methanolic extracts of G. lydia and O

  9. The flat bark beetles (Coleoptera, Silvanidae, Cucujidae, Laemophloeidae of Atlantic Canada

    Directory of Open Access Journals (Sweden)

    Christopher Majka

    2008-09-01

    Full Text Available As a result of the present investigations 18 species of flat bark beetles are known to occur in Atlantic Canada, 10 in New Brunswick, 17 in Nova Scotia, four on Prince Edward Island, six on insular Newfoundland, and one in Labrador. Twenty-three new provincial records are reported and nine species, Uleiota debilis (LeConte, Uleiota dubius (Fabricius, Nausibius clavicornis (Kugelann, Ahasverus advena (Waltl, Cryptolestes pusillus (Schönherr, Cryptolestes turcicus (Grouvelle, Charaphloeus convexulus (LeConte, Charaphloeus species nr. adustus, and Placonotus zimmermanni (LeConte are newly recorded in the region, one of which C. sp. nr. adustus, is newly recorded in Canada as a whole. Eight species are cosmopolitan species introduced to the region and North America, nine are native Nearctic species, and one, Pediacus fuscus Erichson, is Holarctic in distribution. All the introduced species except for one (Silvanus bidentatus (Fabricius, a saproxylic species are found on various stored products, whereas all the native species are saproxylic. Ahasverus longulus (Blatchley, is removed from the species list of New Brunswick and Charophloeus adustus (LeConte is removed from the species list of Nova Scotia. One tropical Asian species, Cryptamorpha desjardinsi (Guérin-Méneville, has been intercepted in the region in imported produce, but is not established. The substantial proportion (44% of the fauna that is comprised of introduced species is highlighted, almost all of which are synanthropic species associated with various dried stored products. The island faunas of Prince Edward Island, Cape Breton Island, and insular Newfoundland are diminished in comparison to the mainland fauna, that of Prince Edward Island being exceptionally so in comparison to other saproxylic groups found there. Of the ten native species, four can be categorized as 'apparently rare' (i.e., comprising ≤ 0.005% of specimens examined from the region. It is possibly that the

  10. Biomarker and molecular isotope approaches to deconvolve the terrestrial carbon isotope record: modern and Eocene calibrations

    Science.gov (United States)

    Diefendorf, A. F.; Freeman, K. H.; Wing, S.; Currano, E. D.

    2010-12-01

    Climate, biome, and plant community are important predictors of carbon isotope patterns recorded in leaves and leaf waxes. However, signatures recorded by terrestrial organic carbon and lipids that have mixed floral sources (e.g., n-alkanes) potentially reflect both plant community changes and climate. More taxonomically specific proxies for plants (i.e., di- and tri-terpenoids for conifers and angiosperms, respectively), can help to resolve the relative influences of changing community and climate, provided differences in biomarker production and lipid biosynthetic fractionation among plants can be better constrained. We present biomarker abundance and carbon isotope values for lipids from leaves, branches and bark of 44 tree species, representing 21 families including deciduous and evergreen conifers and angiosperms. n-alkane production differs greatly between conifer and angiosperm leaves. Both deciduous and evergreen angiosperms make significantly more n-alkanes than conifers, with n-alkanes not detected in over half of the conifers in our study. Terpenoid abundances scale strongly with leaf habit: evergreen species have significantly higher abundances. We combine these relative differences in lipid production with published estimates of fluxes for leaf litter from conifer and angiosperm trees to develop a new proxy approach for estimating paleo plant community inputs to ancient soils and sediments. To test our modern calibration results, we have evaluated n-alkanes and terpenoids from laterally extensive (~18 km) carbonaceous shales and mudstones in Eocene sediments (52.6 Ma) at Fifteenmile Creek in the Bighorn Basin (WY, USA). Our terpenoid-based proxy predicts on average a 40% conifer community, which is remarkably close in agreement with a fossil-based estimate of 36%. n-alkane carbon isotope fractionation (leaf-lipid) differs among plant types, with conifer n-alkanes about 2-3‰ 13C enriched relative to those in angiosperms. Since conifer leaves are

  11. A search of Brassica SI-involved orthologs in buckwheat leads to novel buckwheat sequence identification: MLPK possibly involved in SI response

    Directory of Open Access Journals (Sweden)

    Banović Bojana

    2010-01-01

    Full Text Available Self-incompatibility (SI systems, gamethophytic (GSI and sporophytic (SSI, prevent self-pollination in angiosperms. Buckwheat displays heteromorphic SSI, with pollination allowed only between different flower morphs - thrum and pin. The physiology of thrum and pin morph SI responses are entirely different, resembling homomorphic Brassica SSI and Prunus GSI responses, respectively. Considering angiosperm species may share ancestral SI genes, we examined the presence of Brassica and Prunus SI-involved gene orthologs in the buckwheat genome. We did not find evidence of SRK, SLG and SP11 Brassica or S-RNase and SFB Prunus orthologs in the buckwheat genome, but we found a Brassica MLPK ortholog. We report the partial nucleotide sequence of the buckwheat MLPK and discuss the possible implications of this finding.

  12. THE BIOLOGICAL CYCLE OF SUNFLOWER BROOMRAPE

    Directory of Open Access Journals (Sweden)

    DUCA Maria

    2013-12-01

    Full Text Available Orobanchaceae is a dicot family, which consists of annual and perennial plants distributing from tropical to subarctic regions, predominately in temperate regions. Broomrape (Orobanche cumana Wallr. = Orobanche cernua Loefl. is a parasitic angiosperm that has been causing a great deal of damage to sunflower production in many countries, including Republic of Moldova. This parasitic angiosperm depends entirely on the host for its supply of water and nutrients. A thorough understanding of its biology, including detailed knowledge of the specific mechanisms of parasitism, is needed in order to develop novel control methods. Some main developmental steps are described for the root parasites: seed conditioning and germination, haustorium formation, penetration into host tissues, maturation of the parasite plant, and seed production. All these stages were studied in artificial and natural conditions.

  13. Physiological Effects of Smoke Exposure on Deciduous and Conifer Tree Species

    International Nuclear Information System (INIS)

    Smoke from forest fires can persist in the environment for weeks and while there is a substantial amount of literature examining the effects of smoke exposure on seed germination, the effects of smoke on leaf function are nearly un investigated. The objective of this study was to compare growth and primary and secondary metabolic responses of deciduous angiosperm and evergreen conifer tree species to short smoke exposure. Twenty minutes of smoke exposure resulted in a greater than 50% reduction in photosynthetic capacity in five of the six species we examined. Impairment of photosynthesis in response to smoke was a function of reductions in stomatal conductance and biochemical limitations. In general, deciduous angiosperm species showed a greater sensitivity than evergreen conifers. While there were significant decreases in photosynthesis and stomatal conductance, smoke had no significant effect on growth or secondary defense compound production in any of the tree species examined.

  14. Physiological Effects of Smoke Exposure on Deciduous and Conifer Tree Species

    Directory of Open Access Journals (Sweden)

    Max A. Moritz

    2010-01-01

    Full Text Available Smoke from forest fires can persist in the environment for weeks and while there is a substantial amount of literature examining the effects of smoke exposure on seed germination, the effects of smoke on leaf function are nearly uninvestigated. The objective of this study was to compare growth and primary and secondary metabolic responses of deciduous angiosperm and evergreen conifer tree species to short smoke exposure. Twenty minutes of smoke exposure resulted in a greater than 50% reduction in photosynthetic capacity in five of the six species we examined. Impairment of photosynthesis in response to smoke was a function of reductions in stomatal conductance and biochemical limitations. In general, deciduous angiosperm species showed a greater sensitivity than evergreen conifers. While there were significant decreases in photosynthesis and stomatal conductance, smoke had no significant effect on growth or secondary defense compound production in any of the tree species examined.

  15. Evidence for radiations of cheilanthoid ferns in the Greater Cape Floristic Region

    DEFF Research Database (Denmark)

    Eiserhardt, Wolf L.; Rohwer, Jens G.; Russell, Stephen J.;

    2011-01-01

    The Greater Cape Floristic Region (GCFR) of southern Africa is characterised by large, endemic radiations of flowering plants, the so-called ‘Cape Clades’, but it is unknown whether such radiations are also found in non-angiosperms. We hypothesise that GCFR-endemic lineages exist in the xeric...... cheilanthoid fern species occurring in the GCFR. With two exceptions, all GCFR-endemics are part of two clades that diversified in the Afro-Madagascan region. The GCFR-endemics are further concentrated in three high-endemism subclades that did not originate simultaneously, but within the timeframe of...... angiosperm Cape Clades diversification. According to ancestral area reconstructions the ancestors of the two larger Afro-Madagascan clades were likely GCFR-endemic, and a substantial part of the diversification history of these clades took place in the GCFR. The high diversity of cheilanthoids in the GCFR...

  16. Paleoenvironmental implications from biomarker and stable isotope investigations on the Pliocene Velenje lignite seam (Slovenia)

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel, A.; Sachsenhofer, R.F.; Markic, M.; Gratzer, R.; Lucke, A.; Puttmann, W. [Montan University of Leoben, Leoben (Austria)

    2003-07-01

    A Pliocene lignite seam up to 160 m thick occurs in the Velenje basin (Slovenia). The seam originated in a topogenous mire and evolved within a non-marine, transgressive setting. Differences in soluble organic matter yield and hydrocarbon content of borehole samples from the lignite are related to differences in the composition of free lipids of microbial origin and/or hydrocarbons derived from the biogeochemical degradation of plant tissue. Variations of the redox conditions within the mire are reflected by pristane/phytane ratios. The abundance of terpenoid biomarkers indicates the predominance of gymnosperms over angiosperms, which is consistent with palynomorphic spectra dominated by pollen of the Sequoia-Taxodium-Metasequoia plant community rather than by angiosperms. Evidence is also provided that the content of land plant derived biomarkers and the preservation of plant tissue is controlled by the input of resin-rich, decay-resistant conifers.

  17. A RUMINATE EMBRYO IN BLEPHARIS REPENS (VAHL. ROTH. (ACANTHACEAE

    Directory of Open Access Journals (Sweden)

    Nitin M. LABHANE

    2014-12-01

    Full Text Available The study of morphology of embryo is very significant considering the fact that the embryo represents the important step in the determination of the viability of the seed. Ruminate endosperm has been reported in about 58 families of angiosperms. The rumination caused by the activity of the seed coat or by the endosperm itself is quite recurrent in angiosperm. Ruminate endosperm due to seed coat is reported from the family Acanthaceae in Andrographis paniculata. The rumination of endosperm is also considered as phylogenetically important. Rumination of endosperm is very common, however very little is known about rumination in embryo. The present papers reports the de novo development of ruminate embryo in Blepharis repens. The development of ruminate embryo is seen as an adaptation to ensure proper aeration and optimum germination for survival of the species.

  18. Antibody-based screening of cell wall matrix glycans in ferns reveals taxon, tissue and cell-type specific distribution patterns

    DEFF Research Database (Denmark)

    Leroux, Olivier; Sørensen, Iben; Marcus, Susan E.;

    2015-01-01

    Background: While it is kno3wn that complex tissues with specialized functions emerged during land plant evolution, it is not clear how cell wall polymers and their structural variants are associated with specific tissues or cell types. Moreover, due to the economic importance of many flowering...... plants, ferns have been largely neglected in cell wall comparative studies. Results: To explore fern cell wall diversity sets of monoclonal antibodies directed to matrix glycans of angiosperm cell walls have been used in glycan microarray and in situ analyses with 76 fern species and four species of...... across the ferns and specifically associated with phloem cell walls and similarly the LM11 xylan epitope was associated with xylem cell walls. The LM5 galactan and LM6 arabinan epitopes, linked to pectic supramolecules in angiosperms, were associated with vascular structures with only limited detection...

  19. 100 years of vegetation decline and recovery in Lake Fure, Denmark

    DEFF Research Database (Denmark)

    Jensen, Kaj Sand; Pedersen, Niels Lagergaard; Thorsgaard, Inge;

    2008-01-01

    We analysed the development of submerged macrophytes in Lake Fure, Denmark, experiencing a 30-fold increase of phosphorus input from year 1900 to 1970 and a subsequent decline to twice the 1900 level in 2005. Nutrient enrichment stimulated phytoplankton growth and restricted macrophyte distribution......-history traits. Small angiosperms, mosses and characeans disappeared in the 1970s to 1980s, along with all vegetation in deeper waters (5-8 m), and have only partly recovered recently. Tall angiosperms became dominant while small species vanished. All 10 characeans originally present disappeared at the peak of...... because deeper growth generates more niches. Reduction of species distribution and richness has been reversible following nutrient reduction of the long eutrophied lake, whereas species composition and abundance have not. The historical legacy of community composition is strong, as reflected by closer...

  20. Signal Characteristic of acoustic emission from plant by the water stress

    International Nuclear Information System (INIS)

    To improve environmental control in plant, a signal characteristics of plant has been studied by a nondestructive technique. Hereupon, the acoustic emission (AE) for plant was discussed for water stress detection. AE signals were taken from angiosperms and gymnosperm. It has found that the AE sensor could detect the AE signals on the plant stem right below the sensor. The AE hit counts in daytime was higher than that in night tim, and it was realised that the daily hit counts pattern corresponded with the water stress in the plant. The frequency band of the angiosperms was different from the gymnosperm. The frequency band from outdoor was in accord with that of indoor obtained from the same conditions.

  1. A Long PCR–Based Approach for DNA Enrichment Prior to Next-Generation Sequencing for Systematic Studies

    Directory of Open Access Journals (Sweden)

    Simon Uribe-Convers

    2014-01-01

    Full Text Available Premise of the study: We present an alternative approach for molecular systematic studies that combines long PCR and next-generation sequencing. Our approach can be used to generate templates from any DNA source for next-generation sequencing. Here we test our approach by amplifying complete chloroplast genomes, and we present a set of 58 potentially universal primers for angiosperms to do so. Additionally, this approach is likely to be particularly useful for nuclear and mitochondrial regions. Methods and Results: Chloroplast genomes of 30 species across angiosperms were amplified to test our approach. Amplification success varied depending on whether PCR conditions were optimized for a given taxon. To further test our approach, some amplicons were sequenced on an Illumina HiSeq 2000. Conclusions: Although here we tested this approach by sequencing plastomes, long PCR amplicons could be generated using DNA from any genome, expanding the possibilities of this approach for molecular systematic studies.

  2. Ethnobotanical Study of Tehsil Kabal, Swat District, KPK, Pakistan

    Directory of Open Access Journals (Sweden)

    Imtiaz Ahmad

    2011-01-01

    Full Text Available A total of 140 plants have been reported ethnobotanically from Tehsil Kabal, Swat District. These include the 133 plants (95% of angiosperms, 3 (2.14% of gymnosperms, and 2 (1.42% each of pteridophytes and fungi. The largest family is Lamiaceae represented by 11 species followed by Rosaceae represented by 9 species. Among angiosperms 76 (55.63% were herbs, 17 (12.78% were shrubs, and 40 (30.07% were trees; 127 plants (95.48% were dicot while 6 plants (4.51% were monocot. Most of the plants were used for more than one purpose. Generally the plants were used for medicinal, fuel, timber wood, food, and fodder for cattle purposes.

  3. A long PCR–based approach for DNA enrichment prior to next-generation sequencing for systematic studies 1

    OpenAIRE

    Simon Uribe-Convers; Duke, Justin R.; Moore, Michael J.; Tank, David C

    2014-01-01

    • Premise of the study: We present an alternative approach for molecular systematic studies that combines long PCR and next-generation sequencing. Our approach can be used to generate templates from any DNA source for next-generation sequencing. Here we test our approach by amplifying complete chloroplast genomes, and we present a set of 58 potentially universal primers for angiosperms to do so. Additionally, this approach is likely to be particularly useful for nuclear and mitochondrial regi...

  4. Ant species identity mediates reproductive traits and allocation in an ant-garden bromeliad

    OpenAIRE

    Leroy, Céline; Corbara, Bruno; Pelozuelo, Laurent; Carrias, Jean-François; Dejean, Alain; Céréghino, Régis

    2011-01-01

    Background and Aims Determining the sources of variation in floral morphology is crucial to understanding the mechanisms underlying Angiosperm evolution. The selection of floral and reproductive traits is influenced by the plant's abiotic environment, florivores and pollinators. However, evidence that variations in floral traits result from mutualistic interactions with insects other than pollinators is lacking in the published literature and has rarely been investigated. We aimed to determin...

  5. Nopal Cactus (Opuntia ficus-indica) as a Source of Bioactive Compounds for Nutrition, Health and Disease

    OpenAIRE

    Karym El-Mostafa; Youssef El Kharrassi; Asmaa Badreddine; Pierre Andreoletti; Joseph Vamecq; M'Hammed Saïd El Kebbaj; Norbert Latruffe; Gérard Lizard; Boubker Nasser; Mustapha Cherkaoui-Malki

    2014-01-01

    Opuntia ficus-indica, commonly referred to as prickly pear or nopal cactus, is a dicotyledonous angiosperm plant. It belongs to the Cactaceae family and is characterized by its remarkable adaptation to arid and semi-arid climates in tropical and subtropical regions of the globe. In the last decade, compelling evidence for the nutritional and health benefit potential of this cactus has been provided by academic scientists and private companies. Notably, its rich composition in polyphenols, vit...

  6. Structural Features and Biological Properties of Ellagitannins in Some Plant Families of the Order Myrtales

    OpenAIRE

    Morio Yoshimura; Yoshiaki Amakura; Takashi Yoshida

    2010-01-01

    Plant tannins, including hydrolysable and condensed varieties, are well known antioxidants in medicinal plants, foods, and edible fruits. Their diverse biological properties and potential for disease prevention have been demonstrated by various in vitro and in vivo assays. A number of ellagitannins, the largest group of hydrolysable tannins, have been isolated from dicotyledoneous angiosperms and characterized. This diverse class of tannins is sub-grouped into simple ellagitannins, C-glycosid...

  7. Short-term and long-term effects of tannins on nitrogen mineralisation and litter decomposition in kauri (Agathis australis (D. Don) Lindl.) forests

    OpenAIRE

    Verkaik, E.; Jongkind, A.G.; Berendse, F.

    2006-01-01

    Kauri (Agathis australis (D. Don) Lindl.) occurs naturally in the warm temperate forest of northern New Zealand where it grows mixed with angiosperm tree species. Below mature kauri trees thick organic layers develop in which large amounts of nitrogen are accumulated. This nitrogen seems to be inaccessible to plants. While litter quality can explain the low decomposition rate below kauri, it is not known what causes the accumulation of nitrogen. We hypothesised that kauri tannins reduce nitro...

  8. Cladistic analysis of ribosomal RNAs--the phylogeny of eukaryotes with respect to the endosymbiotic theory.

    Science.gov (United States)

    Wolters, J; Erdmann, V A

    1988-01-01

    A strict cladistic analysis of 5S and 16S rRNA secondary and primary structure confirms particular hypotheses concerning the phylogeny of eukaryotes: plastids of Euglena, green algae and land plants, and the cyanelle of Cyanophora share a specific character and are closely related to cyanobacteria of the Synechococcus-type. Angiosperm mitochondria share specific signatures with the alpha subdivision of rhodobacteria. Cyanophora is a member of the Euglenozoa, the Oomycetes are derived from a group of heterokont algae. PMID:3395680

  9. Future of Endemic Flora of Biodiversity Hotspots in India

    OpenAIRE

    Chitale, Vishwas Sudhir; Behera, Mukund Dev; Roy, Partha Sarthi

    2014-01-01

    India is one of the 12 mega biodiversity countries of the world, which represents 11% of world's flora in about 2.4% of global land mass. Approximately 28% of the total Indian flora and 33% of angiosperms occurring in India are endemic. Higher human population density in biodiversity hotspots in India puts undue pressure on these sensitive eco-regions. In the present study, we predict the future distribution of 637 endemic plant species from three biodiversity hotspots in India; Himalaya, Wes...

  10. Island colonization and evolution of the insular woody habit in Echium L. (Boraginaceae).

    OpenAIRE

    Böhle, U R; Hilger, H.H.; Martin, W. F.

    1996-01-01

    Numerous island-inhabiting species of predominantly herbaceous angiosperm genera are woody shrubs or trees. Such "insular woodiness" is strongly manifested in the genus Echium, in which the continental species of circummediterranean distribution are herbaceous, whereas endemic species of islands along the Atlantic coast of north Africa are woody perennial shrubs. The history of 37 Echium species was traced with 70 kb of noncoding DNA determined from both chloroplast and nuclear genomes. In al...

  11. Optical and ultrastructural study of the pollen grain development in hermaphrodite papaya tree (Carica papaya L.)

    OpenAIRE

    Lídia Márcia Silva Santos; Telma Nair Santana Pereira; Margarete Magalhães de Souza; Pedro Correa Damasceno Junior; Fabiane Rabelo da Costa; Beatriz Ferreira Ribeiro; Noil Gomes de Freitas; Messias Gonzaga Pereira

    2008-01-01

    The objective of this study was to describe the pollen grain development in hermaphrodite papaya tree. The flower buds were collected at different stages of the development and the anthers were treated chemically for observation under optical and electronic transmission microscopes. The pollen grain development followed the normal pattern described for the Angiosperms. The pollen grain development was described from meiocyte to the mature pollen grain. In the microsporogenesis, the microspore...

  12. Sexual ratio and floral biology of the dioecious Neea theifera Oerst. (Nyctaginaceae) in a cerrado rupestre of central Brazil Razão sexual e biologia floral de Neea theifera Oerst. (Nyctaginaceae), uma espécie dióica na vegetação de um cerrado rupestre no Brasil Central

    OpenAIRE

    Felipe Wanderley Amorim; Clesnan Mendes-Rodrigues; Pietro Kiyoshi Maruyama; Paulo Eugênio Oliveira

    2011-01-01

    Dioecy is characterized by a complete separation of sexual functions on male and female plants. It has evolved many times in flowering plants and is widespread among distinct Angiosperm families. It is viewed as a reproductive strategy to reduce endogamy, and to promote optimal resource allocation between male and female sexual functions. Neea theifera is a common species in Cerrado, neotropical savannas in Brazil, but information regarding its reproductive biology is still incomplete. In ord...

  13. The late Oligocene flora from the Río Leona Formation, Argentinian Patagonia

    OpenAIRE

    Césari, Silvia N.; Panti, Carolina; Roberto R Pujana; Francis, Jane E.; Sergio A Marenssi

    2015-01-01

    A late Oligocene plant macrofossil assemblage is described from the Río Leona Formation, Argentinian Patagonia. This includes a fern, “Blechnum turbioensis” Frenguelli, one species of conifer, and sixteen angiosperm taxa. Rosaceae, Myrtaceae, Proteaceae, Lauraceae, Anacardiaceae and Typhaceae are represented by one species in each family. Five species are considered to be members of the Fabales. Three leaf taxa together with Carpolithus seeds are placed in the Nothofagaceae. Palynomorphs and ...

  14. Protein Interaction Network of Arabidopsis thaliana Female Gametophyte Development Identifies Novel Proteins and Relations

    OpenAIRE

    Hosseinpour, Batool; HajiHoseini, Vahid; Kashfi, Rafieh; Ebrahimie, Esmaeil; Hemmatzadeh, Farhid

    2012-01-01

    Although the female gametophyte in angiosperms consists of just seven cells, it has a complex biological network. In this study, female gametophyte microarray data from Arabidopsis thaliana were integrated into the Arabidopsis interactome database to generate a putative interaction map of the female gametophyte development including proteome map based on biological processes and molecular functions of proteins. Biological and functional groups as well as topological characteristics of the net...

  15. Effects of gut passage on the germination of seeds ingested by didelphid marsupials in a neotropical savanna

    OpenAIRE

    Leonardo Guimarães Lessa; Lena Geise; Fabiane Nepomuceno Costa

    2013-01-01

    We analyzed the effects that passage through the guts of seven didelphid species had on the seed germination of 10 plant species. This study was conducted in an area of riparian woodland in a cerrado (savanna) reserve in southeastern Brazil. We found seeds of 23 angiosperm species in 427 fecal samples obtained from seven didelphid species. The plant families most often represented by the seeds found in the fecal samples were Melastomataceae (5 species) and Rubiaceae (4 species) . Most gut-pas...

  16. Ecology of alpine plants in NW Himalaya.

    OpenAIRE

    Dvorský, Miroslav

    2014-01-01

    The westernmost spur of the Tibetan Plateau stretches to Eastern Ladakh in India. It is a region which remains poorly explored because of challenging conditions and long periods of political instability. At the same time, it is one of the highest places on earth supporting angiosperm life, which goes beyond 6000 m a.s.l. here. The whole region, due its remoteness, is practically unaffected by plant invasions and direct human activities. Thus, Ladakh represents a kind of "natural experiment", ...

  17. Targeted isolation, sequence assembly and characterization of two white spruce (Picea glauca) BAC clones for terpenoid synthase and cytochrome P450 genes involved in conifer defence reveal insights into a conifer genome

    OpenAIRE

    Ritland Carol; Keeling Christopher I; Hamberger Britta; Oddy Claire; Yuen Mack; Hall Dawn; Hamberger Björn; Ritland Kermit; Bohlmann Jörg

    2009-01-01

    Abstract Background Conifers are a large group of gymnosperm trees which are separated from the angiosperms by more than 300 million years of independent evolution. Conifer genomes are extremely large and contain considerable amounts of repetitive DNA. Currently, conifer sequence resources exist predominantly as expressed sequence tags (ESTs) and full-length (FL)cDNAs. There is no genome sequence available for a conifer or any other gymnosperm. Conifer defence-related genes often group into l...

  18. Identification and functional characterization of the distinct plant pectin esterases PAE8 and PAE9 and their deletion mutants

    OpenAIRE

    de Souza, Amancio; Hull, Philip A.; Gille, Sascha; Pauly, Markus

    2014-01-01

    Main conclusion PAE8 and PAE9 have pectin acetylesterase activity and together remove one-third of the cell wall acetate associated with pectin formation in Arabidopsis leaves. In pae8 and pae9 mutants, substantial amounts of acetate accumulate in cell walls. In addition, the inflorescence stem height is decreased. Pectic polysaccharides constitute a significant part of the primary cell walls in dicotyledonous angiosperms. This diverse group of polysaccharides has been implicated in several p...

  19. Identification of WOX Family Genes in Selaginella kraussiana for Studies on Stem Cells and Regeneration in Lycophytes

    OpenAIRE

    Ge, Yachao; Liu, Jie; Zeng, Minhuan; He, Jianfeng; Qin, Peng; Huang, Hai; Lin XU

    2016-01-01

    Plant stem cells give rise to all tissues and organs and also serve as the source for plant regeneration. The organization of plant stem cells has undergone a progressive change from simple to complex during the evolution of vascular plants. Most studies on plant stem cells have focused on model angiosperms, the most recently diverged branch of vascular plants. However, our knowledge of stem cell function in other vascular plants is limited. Lycophytes and euphyllophytes (ferns, gymnosperms, ...

  20. Regulation of embryo development in Norway spruce by WOX transcription factors

    OpenAIRE

    Zhu, Tianqing

    2015-01-01

    In seed plants, the apical-basal axis of the plant body is established during early embryogenesis. Major regulatory genes of the apical-basal axis formation belong to the WUSCHEL-RELATED HOMEOBOX (WOX) gene family of transcription factors. The spatiotemporal expression pattern and the molecular role of the WOX genes has mainly been studied in the angiosperm model plant Arabidopsis (Arabidopsis thaliana). Similar information in conifers is limited. The aim of my thesis has been to characterize...

  1. Analysis of the WUSCHEL-RELATED HOMEOBOX gene family in the conifer picea abies reveals extensive conservation as well as dynamic patterns

    OpenAIRE

    Hedman, Harald; Zhu, Tianqing; Von Arnold, Sara; Sohlberg, Joel J.

    2013-01-01

    Background Members of the WUSCHEL-RELATED HOMEOBOX (WOX) gene family have important functions during all stages of plant development and have been implicated in the development of morphological novelties during evolution. Most studies have examined the function of these genes in angiosperms and very little is known from other plant species. Results In this study we examine the presence and expression of WOX genes in the conifer Picea abies. We have cloned 11 WOX genes from both mRNA and genom...

  2. Transcriptome Characteristics and Six Alternative Expressed Genes Positively Correlated with the Phase Transition of Annual Cambial Activities in Chinese Fir (Cunninghamia lanceolata (Lamb.) Hook)

    OpenAIRE

    Wang, Zhanjun; Chen, Jinhui; Liu, Weidong; Luo, Zhanshou; Wang, Pengkai; Zhang, Yanjuan; Zheng, Renhua; Shi, Jisen

    2013-01-01

    Background The molecular mechanisms that govern cambial activity in angiosperms are well established, but little is known about these molecular mechanisms in gymnosperms. Chinese fir (Cunninghamia lanceolata (Lamb.) Hook), a diploid (2n  = 2x  = 22) gymnosperm, is one of the most important industrial and commercial timber species in China. Here, we performed transcriptome sequencing to identify the repertoire of genes expressed in cambium tissue of Chinese fir. Methodology/Principal Findings ...

  3. First report of three redlisted tree species from swampy relics of Goa State, India

    OpenAIRE

    A. Prabhugaonkar; D.K. Mesta; M. K. Janarthanam

    2014-01-01

    Myristica swamps, one of the relic ecosystems of Western Ghats, are considered home for many rare and endemic angiosperms. During an inventory of Myristica swamps in Goa State, two critically endangered species and one endangered species, viz. Semecarpus kathalekanensis Dasappa and M.H.Swaminath, Syzygium travancoricum Gamble and Myristica fatua Houtt. var. magnifica (Bedd.) J. Sinclair respectively were recorded. Present report forms first record of these three tree species from the Goa Stat...

  4. Asynchronous origins of ectomycorrhizal clades of Agaricales

    OpenAIRE

    Ryberg, Martin; Matheny, P. Brandon

    2011-01-01

    The ectomycorrhizal (ECM) symbiosis is the most widespread biotrophic nutritional mode in mushroom-forming fungi. ECM fungi include, though are not limited to, about 5000 described species of Agaricales from numerous, independently evolved lineages. Two central hypotheses suggest different explanations for the origin of ECM fungal diversity: (i) dual origins, initially with the Pinaceae in the Jurassic and later with angiosperms during the Late Cretaceous, and (ii) a simultaneous and converge...

  5. Phloem sap proteins from Cucurbita maxima and Ricinus communis have the capacity to traffic cell to cell through plasmodesmata

    OpenAIRE

    Balachandran, Suchandra; Xiang, Yu; Schobert, Christian; Thompson, Gary A.; Lucas, William J.

    1997-01-01

    In angiosperms, the functional enucleate sieve tube system of the phloem appears to be maintained by the surrounding companion cells. In this study, we tested the hypothesis that polypeptides present within the phloem sap traffic cell to cell from the companion cells, where they are synthesized, into the sieve tube via plasmodesmata. Coinjection of fluorescently labeled dextrans along with size-fractionated Cucurbita maxima phloem proteins, ranging in size from 10 to 200 kDa, as well as injec...

  6. Diverse Pollination Networks Key to Ecosystem Sustainability

    OpenAIRE

    Colin Fontaine; Isabelle Dajoz; Jacques Meriguet; Michel Loreau

    2005-01-01

    Pollination is exclusively or mainly animal mediated for 70% to 90% of angiosperm species. Thus, pollinators provide an essential ecosystem service to humankind. However, the impact of human-induced biodiversity loss on the functioning of plant–pollinator interactions has not been tested experimentally. To understand how plant communities respond to diversity changes in their pollinating fauna, we manipulated the functional diversity of both plants and pollinators under natural conditions. In...

  7. Comparative Genome Analysis and Phylogenetic Relationship of Order Liliales Insight from the Complete Plastid Genome Sequences of Two Lilies (Lilium longiflorum and Alstroemeria aurea)

    OpenAIRE

    Kim, Jung Sung; Kim, Joo-Hwan

    2013-01-01

    Monocots are one of the most diverse, successful and economically important clades of angiosperms. We attempt to analyse the complete plastid genome sequences of two lilies and their lengths were 152,793bp in Lilium longiflorum (Liliaceae) and 155,510bp in Alstroemeria aurea (Alstroemeriaceae). Phylogenetic analyses were performed for 28 taxa including major lineages of monocots using the sequences of 79 plastid genes for clarifying the phylogenetic relationship of the order Liliales. The sis...

  8. In vitro ectomycorrhiza formation by monokaryotic and dikaryotic isolates of Pisolithus microcarpus in Eucalyptus grandis Formação de ectomicorrizas in vitro por isolados monocarióticos e dicarióticos de Pisolithus microcarpus em Eucalyptus grandis

    OpenAIRE

    Maurício Dutra Costa; André Narvaes da Rocha Campos; Matheus Loureiro Santos; Arnaldo Chaer Borges

    2010-01-01

    The formation of ectomycorrhizas by monokaryotic and dikaryotic isolates of Pisolithus microcarpus (Cooke & Massee) G. Cunn. in Eucalyptus grandis W. Hill ex Maid. was studied by in vitro synthesis in Petri dishes. The formation of ectomycorrhizas was observed for all strains tested. Ectomycorrhizas formed by the monokaryotic strains presented a sheath of hyphae around the roots and a Hartig net limited to the epidermis layer, typical of the angiosperm ectomycorrhizas. Colonization rates, a m...

  9. Towards resolving Lamiales relationships: insights from rapidly evolving chloroplast sequences

    OpenAIRE

    Heubl Günther; Borsch Thomas; Albach Dirk C; Fischer Eberhard; Fleischmann Andreas; Schäferhoff Bastian; Müller Kai F

    2010-01-01

    Abstract Background In the large angiosperm order Lamiales, a diverse array of highly specialized life strategies such as carnivory, parasitism, epiphytism, and desiccation tolerance occur, and some lineages possess drastically accelerated DNA substitutional rates or miniaturized genomes. However, understanding the evolution of these phenomena in the order, and clarifying borders of and relationships among lamialean families, has been hindered by largely unresolved trees in the past. Results ...

  10. STATUS TAKSONOMI, DISTRIBUSI DAN KATEGORI STATUS KONSERVASI MAGNOLIACEAE DI INDONESIA

    OpenAIRE

    Andes Hamuraby Rozak

    2012-01-01

    The Family of Magnoliaceae is one of the most primitive taxa in the world.  Knowledge of this family is essential for studies on the origin, evolution and systematics of Angiosperms.  There are 223 species belongs to this family in the world and 25 of them are found in Indonesia. This paper explains taxonomy, distribution, and conservation status of the family Magnoliaceae in Indonesia.

  11. Multilocus Sex Determination Revealed in Two Populations of Gynodioecious Wild Strawberry, Fragaria vesca subsp. bracteata

    OpenAIRE

    Ashman, Tia-Lynn; Tennessen, Jacob A.; Dalton, Rebecca M.; Govindarajulu, Rajanikanth; Koski, Matthew H.; Liston, Aaron

    2015-01-01

    Gynodioecy, the coexistence of females and hermaphrodites, occurs in 20% of angiosperm families and often enables transitions between hermaphroditism and dioecy. Clarifying mechanisms of sex determination in gynodioecious species can thus illuminate sexual system evolution. Genetic determination of gynodioecy, however, can be complex and is not fully characterized in any wild species. We used targeted sequence capture to genetically map a novel nuclear contributor to male sterility in a self-...

  12. Comparative analysis of microspore size variability in the genus Aesculus (Hippocastanaceae)

    OpenAIRE

    Ćalić-Dragosavac Dušica; Zdravković-Korać Snežana; Miljković Danijela; Radojević Ljiljana

    2009-01-01

    Pollen size varies extensively among angiosperm species and partially reflects evolutionary adaptation of each species to the pollination and fertilization environment. Size of uninuclear microspores in Aesculus parviflora was analyzed and compared with the size of microspores in Aesculus hippocastanum, Aesculus carnea, and Aesculus flava. The microspores came from closed flower buds of different size (3, 4, and 5 mm) isolated from lower (female flowers), middle (bisexual flowers), and upper ...

  13. Exploring lignification in conifers by silencing hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyltransferase in Pinus radiata

    OpenAIRE

    Wagner, Armin; Ralph, John; Akiyama, Takuya; Flint, Heather; Phillips, Lorelle; Torr, Kirk; Nanayakkara, Bernadette; Te Kiri, Lana

    2007-01-01

    The enzyme hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyltransferase (HCT) is involved in the production of methoxylated monolignols that are precursors to guaiacyl and syringyl lignin in angiosperm species. We identified and cloned a putative HCT gene from Pinus radiata, a coniferous gymnosperm that does not produce syringyl lignin. This gene was up-regulated during tracheary element (TE) formation in P. radiata cell cultures and showed 72.6% identity to the amino acid sequence of the Nicot...

  14. Chemical Markers of Occupational Exposure to Teak Wood Dust

    OpenAIRE

    Carrieri, Mariella; Bartolucci, Giovanni Battista; Lee, Taekhee; Barbero, Ana; Harper, Martin

    2014-01-01

    A novel high-performance liquid chromatographic/ultraviolet method was developed to detect lapachol (LP) and deoxylapachol (DLP) in wood dust as chemical markers of teak wood (a suspected human carcinogen). The specificity of this analysis was determined by noting the absence of LP and DLP in 12 other specimens of different woods belonging to the angiosperm family. The consistency was examined by analyzing teak from three different sources, where the percentages (wt/wt) of the chemicals range...

  15. Phylogeny of seed plants based on all three genomic compartments: Extant gymnosperms are monophyletic and Gnetales' closest relatives are conifers

    OpenAIRE

    Bowe, L. Michelle; Coat, Gwénaële; dePamphilis, Claude W.

    2000-01-01

    Efforts to resolve Darwin's “abominable mystery”—the origin of angiosperms—have led to the conclusion that Gnetales and various fossil groups are sister to angiosperms, forming the “anthophytes.” Morphological homologies, however, are difficult to interpret, and molecular data have not provided clear resolution of relationships among major groups of seed plants. We introduce two sequence data sets from slowly evolving mitochondrial genes, cox1 and atpA, which unambiguously reject the anthophy...

  16. An evolutionary basis for pollination ecology

    OpenAIRE

    Willemstein, S.C.

    1987-01-01

    In the introduction and chapter 2 the incentives and way of reasoning are given for the description of an evolutionary basis of pollination ecology. Starting from the until recently rather anecdotical character of the study of pollination ecology as a whole, and in the absence of large-scale correlations of flowerecologically important character states with angiosperm and insect phylogeny (in the sense of Hennig, 1966), an attempt is made to derive directed evolutionary lines (transformation ...

  17. Study of Thiosemicarbazone Derivative of Essential Fatty Acid

    OpenAIRE

    Borhade, Shobha

    2014-01-01

    Essential fatty acids results in numerous health benefits. Only two fatty acids are known to be essential for human alpha-linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid).The importance of omega-3 fatty acids for physical well-being has been recognised for several decades . Omega-3 fatty acids have anti-inflammatory, antithrombotic, antiarrhythmic and hypolipidaemic effects. Cannabis sativa (Hemp) is an angiosperm belonging to the cannabaceae family and cannabi...

  18. Biparental inbreeding depression, genetic relatedness and progeny vigour in a wind-pollinated treeline species in Argentina

    OpenAIRE

    Seltmann, Peggy; Hensen, Isabell; Renison, Daniel; Wesche, Karsten; Ploch, Sebastian; Dueñas, Juan; Cocucci, Andrea; Jung, Klaus

    2009-01-01

    Spatially restricted gene flow and resulting spatial genetic structure are generally considered as being the primary controlling factors in the dynamics of biparental inbreeding depression in a wide range of plant species. However, wind-pollinated angiosperm trees have not been studied adequately in this respect. The present study analyses the relationships among parental genetic similarity, outcrossing distances, progeny vigour and mortality in Polylepis australis (Rosaceae), a wind-pollinat...

  19. Loss of matK RNA editing in seed plant chloroplasts

    Directory of Open Access Journals (Sweden)

    Maier Uwe G

    2009-08-01

    Full Text Available Abstract Background RNA editing in chloroplasts of angiosperms proceeds by C-to-U conversions at specific sites. Nuclear-encoded factors are required for the recognition of cis-elements located immediately upstream of editing sites. The ensemble of editing sites in a chloroplast genome differs widely between species, and editing sites are thought to evolve rapidly. However, large-scale analyses of the evolution of individual editing sites have not yet been undertaken. Results Here, we analyzed the evolution of two chloroplast editing sites, matK-2 and matK-3, for which DNA sequences from thousands of angiosperm species are available. Both sites are found in most major taxa, including deep-branching families such as the nymphaeaceae. However, 36 isolated taxa scattered across the entire tree lack a C at one of the two matK editing sites. Tests of several exemplary species from this in silico analysis of matK processing unexpectedly revealed that one of the two sites remain unedited in almost half of all species examined. A comparison of sequences between editors and non-editors showed that specific nucleotides co-evolve with the C at the matK editing sites, suggesting that these nucleotides are critical for editing-site recognition. Conclusion (i Both matK editing sites were present in the common ancestor of all angiosperms and have been independently lost multiple times during angiosperm evolution. (ii The editing activities corresponding to matK-2 and matK-3 are unstable. (iii A small number of third-codon positions in the vicinity of editing sites are selectively constrained independent of the presence of the editing site, most likely because of interacting RNA-binding proteins.

  20. Therapeutic Potential of Moringa oleifera Leaves in Chronic Hyperglycemia and Dyslipidemia: A Review

    OpenAIRE

    Mbikay, Majambu

    2012-01-01

    Moringa oleifera (M. oleifera) is an angiosperm plant, native of the Indian subcontinent, where its various parts have been utilized throughout history as food and medicine. It is now cultivated in all tropical and sub-tropical regions of the world. The nutritional, prophylactic, and therapeutic virtues of this plant are being extolled on the Internet. Dietary consumption of its part is therein promoted as a strategy of personal health preservation and self-medication in various diseases. The...

  1. Nonneutral Evolution of Organelle Genes in Silene vulgaris

    OpenAIRE

    Houliston, Gary J.; Olson, Matthew S.

    2006-01-01

    Knowledge of mitochondrial gene evolution in angiosperms has taken a dramatic shift within the past decade, from universal slow rates of nucleotide change to a growing realization of high variation in rates among lineages. Additionally, evidence of paternal inheritance of plant mitochondria and recombination among mitochondrial genomes within heteroplasmic individuals has led to speculation about the potential for independent evolution of organellar genes. We report intraspecific mitochondria...

  2. A common origin for woody Sonchus and five related genera in the Macaronesian islands: molecular evidence for extensive radiation.

    OpenAIRE

    Kim, S. C.; Crawford, D J; Francisco-Ortega, J.; Santos-Guerra, A.

    1996-01-01

    Woody Sonchus and five related genera (Babcockia, Taeckholmia, Sventenia, Lactucosonchus, and Prenanthes) of the Macaronesian islands have been regarded as an outstanding example of adaptive radiation in angiosperms. Internal transcribed spacer region of the nuclear rDNA (ITS) sequences were used to demonstrate that, despite the extensive morphological and ecological diversity of the plants, the entire alliance in insular Macaronesia has a common origin. The sequence data place Lactucosonchus...

  3. An Ancestral Role for CONSTITUTIVE TRIPLE RESPONSE1 Proteins in Both Ethylene and Abscisic Acid Signaling.

    Science.gov (United States)

    Yasumura, Yuki; Pierik, Ronald; Kelly, Steven; Sakuta, Masaaki; Voesenek, Laurentius A C J; Harberd, Nicholas P

    2015-09-01

    Land plants have evolved adaptive regulatory mechanisms enabling the survival of environmental stresses associated with terrestrial life. Here, we focus on the evolution of the regulatory CONSTITUTIVE TRIPLE RESPONSE1 (CTR1) component of the ethylene signaling pathway that modulates stress-related changes in plant growth and development. First, we compare CTR1-like proteins from a bryophyte, Physcomitrella patens (representative of early divergent land plants), with those of more recently diverged lycophyte and angiosperm species (including Arabidopsis [Arabidopsis thaliana]) and identify a monophyletic CTR1 family. The fully sequenced P. patens genome encodes only a single member of this family (PpCTR1L). Next, we compare the functions of PpCTR1L with that of related angiosperm proteins. We show that, like angiosperm CTR1 proteins (e.g. AtCTR1 of Arabidopsis), PpCTR1L modulates downstream ethylene signaling via direct interaction with ethylene receptors. These functions, therefore, likely predate the divergence of the bryophytes from the land-plant lineage. However, we also show that PpCTR1L unexpectedly has dual functions and additionally modulates abscisic acid (ABA) signaling. In contrast, while AtCTR1 lacks detectable ABA signaling functions, Arabidopsis has during evolution acquired another homolog that is functionally distinct from AtCTR1. In conclusion, the roles of CTR1-related proteins appear to have functionally diversified during land-plant evolution, and angiosperm CTR1-related proteins appear to have lost an ancestral ABA signaling function. Our study provides new insights into how molecular events such as gene duplication and functional differentiation may have contributed to the adaptive evolution of regulatory mechanisms in plants. PMID:26243614

  4. Expression divergence of the AGL6 MADS domain transcription factor lineage after a core eudicot duplication suggests functional diversification

    OpenAIRE

    Melzer Siegbert; Becker Annette; Vekemans Dries; Viaene Tom; Geuten Koen

    2010-01-01

    Abstract Background Because of their known role as transcriptional regulators of key plant developmental processes, the diversification of MADS-box gene function is thought to be a major driving force in the developmental evolution of plants. Yet the function of some MADS-box gene subfamilies has remained elusive thus far. One such lineage, AGL6, has now been functionally characterized in three angiosperm species, but a phylogenetic framework for comparison of AGL6 gene function is currently ...

  5. Dependency on floral resources determines the animals' responses to floral scents

    OpenAIRE

    Junker, Robert R; Blüthgen, Nico

    2010-01-01

    Animal-pollinated angiosperms either depend on cross-pollination or may also reproduce after self-pollination—the former are thus obligately, the latter facultatively dependent on the service of animal-pollinators. Analogously, flower visitors either solely feed on floral resources or complement their diet with these, and are hence dependent or not on the flowers they visit. We assume that obligate flower visitors evolved abilities that enable them to effectively forage on flowers including m...

  6. Wild bees preferentially visit Rudbeckia flower heads with exaggerated ultraviolet absorbing floral guides

    OpenAIRE

    Lisa Horth; Laura Campbell; Rebecca Bray

    2014-01-01

    ABSTRACT Here, we report on the results of an experimental study that assessed the visitation frequency of wild bees to conspecific flowers with different sized floral guides. UV absorbent floral guides are ubiquitous in Angiosperms, yet surprisingly little is known about conspecific variation in these guides and very few studies have evaluated pollinator response to UV guide manipulation. This is true despite our rich understanding about learning and color preferences in bees. Historical dog...

  7. Architecture and evolution of a minute plant genome.

    OpenAIRE

    Ibarra-Laclette, E.; Lyons, E.; Hernández-Guzmán, G.; Pérez-Torres, C.A.; L. Carretero-Paulet; Chang, T.-H.; Lan, T.; Welch, A.J.; Abraham Juárez, M.J.; Simpson, J; Fernández-Cortés, A.; Arteaga-Vázquez, M.; Góngora-Castillo, E.; Acevedo-Hernández, A.; Schuster, S.C.

    2013-01-01

    It has been argued that the evolution of plant genome size is principally unidirectional and increasing owing to the varied action of whole-genome duplications (WGDs) and mobile element proliferation1. However, extreme genome size reductions have been reported in the angiosperm family tree. Here we report the sequence of the 82-megabase genome of the carnivorous bladderwort plant Utricularia gibba. Despite its tiny size, the U. gibba genome accommodates a typical number of genes for a plant, ...

  8. A Set of 100 Chloroplast DNA Primer Pairs to Study Population Genetics and Phylogeny in Monocotyledons

    OpenAIRE

    Scarcelli, Nora; Barnaud, Adeline; Eiserhardt, Wolf; Treier, Urs A.; Seveno, Marie; d'Anfray, Amélie; Vigouroux, Yves; Pintaud, Jean-Christophe

    2011-01-01

    Chloroplast DNA sequences are of great interest for population genetics and phylogenetic studies. However, only a small set of markers are commonly used. Most of them have been designed for amplification in a large range of Angiosperms and are located in the Large Single Copy (LSC). Here we developed a new set of 100 primer pairs optimized for amplification in Monocotyledons. Primer pairs amplify coding (exon) and non-coding regions (intron and intergenic spacer). They span the different chlo...

  9. The role of photosynthesis and amino acid metabolism in the energy status during seed development

    OpenAIRE

    Galili, Gad; Avin-Wittenberg, Tamar; Angelovici, Ruthie; Fernie, Alisdair R

    2014-01-01

    Seeds are the major organs responsible for the evolutionary upkeep of angiosperm plants. Seeds accumulate significant amounts of storage compounds used as nutrients and energy reserves during the initial stages of seed germination. The accumulation of storage compounds requires significant amounts of energy, the generation of which can be limited due to reduced penetration of oxygen and light particularly into the inner parts of seeds. In this review, we discuss the adjustment of seed metabol...

  10. Vascular anatomy of kiwi fruit and its implications for the origin of carpels

    OpenAIRE

    Guo, Xue-Min; Xiao, Xiao; Wang, Gui-Xi; Gao, Rong-Fu

    2013-01-01

    Kiwi fruit is of great agricultural, botanical, and economic interest. The flower of kiwi fruit has axile placentation, which is typical for Actinidiaceae. Axile placentation is thought derived through fusion of conduplicate carpels with marginal placentation according to the traditional doctrine. Recent progress in angiosperm systematics has refuted this traditional doctrine and placed ANITA clade rather than Magnoliaceae as the basalmost clade. However, the former traditional doctrine stays...

  11. STATUS TAKSONOMI, DISTRIBUSI DAN KATEGORI STATUS KONSERVASI MAGNOLIACEAE DI INDONESIA

    Directory of Open Access Journals (Sweden)

    Andes Hamuraby Rozak

    2012-07-01

    Full Text Available The Family of Magnoliaceae is one of the most primitive taxa in the world.  Knowledge of this family is essential for studies on the origin, evolution and systematics of Angiosperms.  There are 223 species belongs to this family in the world and 25 of them are found in Indonesia. This paper explains taxonomy, distribution, and conservation status of the family Magnoliaceae in Indonesia.

  12. Alimentazione di Marmota marmota in praterie altimontane delle dolomiti bellunesi

    OpenAIRE

    Alessandro Rudatis; Renzo De Battisti

    2006-01-01

    Abstract The diet of Marmota marmota in the mountain prairie of south-eastern Italian Alps. Diet composition of two family groups of alpine marmots was investigated in two areas of the Agordino’s Dolomites (Italian Alps) in June-September 2001, by means of microscopic analysis of faeces and of direct observation of feeding activity. During the whole period of activity, a high consume of Angiosperms was co...

  13. Recent advances in understanding of meiosis initiation and the apomictic pathway in plants

    OpenAIRE

    Wang, Chung-Ju R.; Tseng, Ching-Chih

    2014-01-01

    Meiosis, a specialized cell division to produce haploid cells, marks the transition from a sporophytic to a gametophytic generation in the life cycle of plants. In angiosperms, meiosis takes place in sporogenous cells that develop de novo from somatic cells in anthers or ovules. A successful transition from the mitotic cycle to the meiotic program in sporogenous cells is crucial for sexual reproduction. By contrast, when meiosis is bypassed or a mitosis-like division occurs to produce unreduc...

  14. Plant sexual reproduction: aspects of interaction, history and regulation

    OpenAIRE

    Willemse, M.T.M.

    2003-01-01

    Sexual reproduction in angiosperms is an interactive process involving the sporophyte, gametophytes, embryo and endosperm as well as the environment, aimed at achieving pollination, fertilization and dispersal. This interaction occurs via an interface with nutrients and signals outside the cell and even outside the plant. Sexual reproduction has a history. In water, algae have different types of sex organs and gametes, and in some cases the female gamete stays on the plant. The zygote uses wa...

  15. Distinctive convergence in Australian floral colours seen through the eyes of Australian birds

    OpenAIRE

    Burd, Martin; Stayton, C. Tristan; Shrestha, Mani; Dyer, Adrian G.

    2014-01-01

    We used a colour-space model of avian vision to assess whether a distinctive bird pollination syndrome exists for floral colour among Australian angiosperms. We also used a novel phylogenetically based method to assess whether such a syndrome represents a significant degree of convergent evolution. About half of the 80 species in our sample that attract nectarivorous birds had floral colours in a small, isolated region of colour space characterized by an emphasis on long-wavelength reflection...

  16. Meta-Analysis of Pollen Limitation Reveals the Relevance of Pollination Generalization in the Atlantic Forest of Brazil

    OpenAIRE

    Wolowski, Marina; Ashman, Tia-Lynn; Freitas, Leandro

    2014-01-01

    Despite the extensive knowledge of pollen limitation in angiosperms, its assessment within tropical forests is still limited. Especially lacking are large scale comparisons of species within this biome – one that is highly diverse but also becoming increasingly threatened. In fact, many tropical plant species depend upon pollinators for reproduction but evaluation of the impact of this dependence via different levels of pollination specialization has yet to be made at the biome scale. We asse...

  17. Reduction of pollen viability of cantaloupe melon (Cucumis melo L., Cucurbitaceae) by honeybee body hairs contact

    OpenAIRE

    Dibos, Chloe; Gibert, Caroline; Suchail, Séverine; Vaissière, Bernard; El Maataoui, Mohamed; Queen's University Belfast

    2008-01-01

    Honeybees take part in 80% of Angiosperms pollination. With pollen transport and transfer from flower to flower, they increase fruit and seed set compared to hand pollination. Nevertheless, it was shown in some species that bee contact decreases pollen viability. The aim of this study was to assess the bee contact effect on Cucurbitaceae pollen viability during different times. The studied model is cantaloupe melon (Cucumis melo L.), an economically important crop of Southern F...

  18. Transcriptional analysis of Pinus sylvestris roots challenged with the ectomycorrhizal fungus Laccaria bicolor

    OpenAIRE

    Sederoff Ron; van Zyl Len; Osborne Jason; Li Guosheng; Adomas Aleksandra; Heller Gregory; Finlay Roger D; Stenlid Jan; Asiegbu Frederick O

    2008-01-01

    Abstract Background Symbiotic ectomycorrhizal associations of fungi with forest trees play important and economically significant roles in the nutrition, growth and health of boreal forest trees, as well as in nutrient cycling. The ecology and physiology of ectomycorrhizal associations with Pinus sp are very well documented but very little is known about the molecular mechanisms behind these mutualistic interactions with gymnosperms as compared to angiosperms. Results Using a micro-array appr...

  19. Chloroplast gene sequences and the study of plant evolution.

    OpenAIRE

    Clegg, M T

    1993-01-01

    A large body of sequence data has accumulated for the chloroplast-encoded gene ribulose-1,5-biphosphate carboxylase/oxygenase (rbcL) as the result of a cooperative effort involving many laboratories. The data span all seed plants, including most major lineages from the angiosperms, and as such they provide an unprecedented opportunity to study plant evolutionary history. The full analysis of this large data set poses many problems and opportunities for plant evolutionary biologists and for bi...

  20. Genus Cistus: a model for exploring labdane-type diterpenes' biosynthesis and a natural source of high value products with biological, aromatic, and pharmacological properties

    OpenAIRE

    AngelosK.Kanellis; StefanosKostas; VasilikiFalara

    2014-01-01

    The family Cistaceae (Angiosperm, Malvales) consists of 8 genera and 180 species, with 5 genera native to the Mediterranean area (Cistus, Fumara, Halimium, Helianthemum, and Tuberaria). Traditionally, a number of Cistus species have been used in Mediterranean folk medicine as herbal tea infusions for healing digestive problems and colds, as extracts for the treatment of diseases, and as fragrances. The resin, ladano, secreted by the glandular trichomes of certain Cistus species contains a num...

  1. Observations on the Biology and Anatomy of Myerslopiidae (Hemiptera, Membracoidea)

    OpenAIRE

    Roman Rakitov

    2015-01-01

    Adults and nymphs of Mapuchea chilensis (Nielson), from the poorly known family Myerslopiidae, were collected from the litter horizon of temperate forests and shrub bogs in southern Chile. The species apparently feeds on roots and creeping stems of angiosperms. Salivary sheaths of captive specimens terminated in vascular bundles. Indirect evidence suggests feeding on phloem sap. Both nymphs and adults are strong jumpers and both actively disperse, as evidenced by their capture in pan traps. T...

  2. ORNAMENTAL SPECIES USED IN WATER GARDENS FROM SOUTH KOREA

    OpenAIRE

    PARK SANG KUN; CHO HAE RYONG; BUTA ERZSEBET; CANTOR MARIA

    2009-01-01

    Aquatic plants (hydrophytic plants or hydrophytes) are plants that have adapted to live in or on aquatic environments. Because they are living under the water require numerous special adaptations, aquatic plants can only grow in water or permanently saturated soil. Aquatic vascular plants can be ferns or angiosperms (from a variety of families, including monocots and dicots). As opposed to plants types such as mesophytes and xerophytes, hydrophytes do not have a problem in retaining water due...

  3. Evolutionary aspects of non-cell-autonomous regulation in vascular plants: structural background and models to study

    OpenAIRE

    Anastasiia I. Evkaikina; Marina A. Romanova; Olga V. Voitsekhovskaja

    2014-01-01

    Plasmodesmata (PD) serve for the exchange of information in form of miRNA, proteins, and mRNA between adjacent cells in the course of plant development. This fundamental role of PD is well established in angiosperms but has not yet been traced back to the evolutionary ancient plant taxa where functional studies lag behind studies of PD structure and ontogenetic origin. There is convincing evidence that the ability to form secondary (post-cytokinesis) PD, which can connect any adjacent cells, ...

  4. Identification of WOX family genes in Selaginella kraussiana for studies on stem cells and regeneration in lycophytes

    OpenAIRE

    Yachao eGe; Jie eLiu; Minhuan eZeng; Jianfeng eHe; Peng eQin; Hai eHuang; Lin eXu

    2016-01-01

    Plant stem cells give rise to all tissues and organs and also serve as the source for plant regeneration. The organization of plant stem cells has undergone a progressive change from simple to complex during the evolution of vascular plants. Most studies on plant stem cells have focused on model angiosperms, the most recently diverged branch of vascular plants. However, our knowledge of stem cell function in other vascular plants is limited. Lycophytes and euphyllophytes (ferns, gymnosperms, ...

  5. Exploring potential new floral organ morphogenesis genes of Arabidopsis thaliana using systems biology approach

    OpenAIRE

    Xie, Wenchuan; Huang, Junfeng; Liu, Yang; Rao, Jianan; Luo, Da; He, Miao

    2015-01-01

    Flowering is one of the important defining features of angiosperms. The initiation of flower development and the formation of different floral organs are the results of the interplays among numerous genes. But until now, just fewer genes have been found linked with flower development. And the functions of lots of genes of Arabidopsis thaliana are still unknown. Although, the quartet model successfully simplified the ABCDE model to elaborate the molecular mechanism by introducing protein-prote...

  6. Cold-induced sudden reversible lowering of in vivo chlorophyll fluorescence after saturating light pulses : a sensitive marker for chilling susceptibility.

    Science.gov (United States)

    Larcher, W; Neuner, G

    1989-03-01

    In chilling-sensitive plants (Glycine max, Saintpaulia ionantha, Saccharum officinarum) a sudden reversible drop in chlorophyll fluorescence occurs during photosynthetic induction immediately following saturating light pulses at low temperatures in the range 4 to 8 degrees C. A comparison of two soybean cultivars of different chilling sensitivities revealed that this phenomenon, termed lowwave, indicates specific thresholds of low temperature stress. Its occurrence under controlled chilling can be regarded as a quantitative marker for screening chilling susceptibility in angiosperms. PMID:16666615

  7. The WIGGUM gene is required for proper regulation of floral meristem size in Arabidopsis

    OpenAIRE

    Running, Mark P; Fletcher, Jennifer C; Meyerowitz, Elliot M.

    1998-01-01

    The study of cell division control within developing tissues is central to understanding the processes of pattern formation. The floral meristem of angiosperms gives rise to floral organs in a particular number and pattern. Despite its critical role, little is known about how cell division is controlled in the floral meristem, and few genes involved have been identified. We describe the phenotypic effects of mutations in WIGGUM, a gene required for control of cell proliferation in the floral ...

  8. Transcriptome profiling for discovery of genes involved in shoot apical meristem and flower development

    OpenAIRE

    Singh, Vikash K.; Mukesh Jain

    2014-01-01

    Flower development is one of the major developmental processes that governs seed setting in angiosperms. However, little is known about the molecular mechanisms underlying flower development in legumes. Employing RNA-seq for various stages of flower development and few vegetative tissues in chickpea, we identified differentially expressed genes in flower tissues/stages in comparison to vegetative tissues, which are related to various biological processes and molecular functions during flower ...

  9. The ERECTA, CLAVATA and class III HD-ZIP Pathways Display Synergistic Interactions in Regulating Floral Meristem Activities

    OpenAIRE

    Landau, Udi; Asis, Lior; Eshed Williams, Leor

    2015-01-01

    In angiosperms, the production of flowers marks the beginning of the reproductive phase. At the emergence of flower primordia on the flanks of the inflorescence meristem, the WUSCHEL (WUS) gene, which encodes a homeodomain transcription factor starts to be expressed and establishes de novo stem cell population, founder of the floral meristem (FM). Similarly to the shoot apical meristem a precise spatial and temporal expression pattern of WUS is required and maintained through strict regulatio...

  10. A homeobox gene with potential developmental control function in the meristem of the conifer Picea abies

    OpenAIRE

    Sundås-Larsson, A.; Svenson, M; H. Liao; Engström, P

    1998-01-01

    Many homeobox genes control essential developmental processes in animals and plants. In this report, we describe the first cDNA corresponding to a homeobox gene isolated from a gymnosperm, the HBK1 gene from the conifer Picea abies (L.) Karst (Norway spruce). The sequence shows distinct similarities specifically to the KNOX (knotted-like homeobox) class of homeobox genes known from different angiosperm plants. The deduced amino acid sequence of HBK1 is strikingly similar within the homeodomai...

  11. Cell division pattern influences gene expression in the shoot apical meristem

    OpenAIRE

    Wyrzykowska, Joanna; Fleming, Andrew

    2003-01-01

    The shoot apical meristem of angiosperms shows a highly conserved cellular architecture in which a change of cell division orientation correlates with early events of leaf initiation. However, the causal role of this altered cellular parameter in leaf formation is debatable. We have used the dynamin-like protein phragmoplastin as a tool to modify the pattern of cell division within the apical meristem. Taking a microinduction approach, we show that local alteration in cell division orientatio...

  12. Transcriptome sequencing of three Ranunculus species (Ranunculaceae) reveals candidate genes in adaptation from terrestrial to aquatic habitats

    OpenAIRE

    Chen, Ling-Yun; Zhao, Shu-Ying; Wang, Qing-Feng; MOODY, MICHAEL L.

    2015-01-01

    Adaptation to aquatic habitats is a formidable challenge for terrestrial angiosperms that has long intrigued scientists. As part of a suite of work to explore the molecular mechanism of adaptation to aquatic habitats, we here sequenced the transcriptome of the submerged aquatic plant Ranunculus bungei, and two terrestrial relatives R. cantoniensis and R. brotherusii, followed by comparative evolutionary analyses to determine candidate genes for adaption to aquatic habitats. We obtained 126,03...

  13. Pollen storages in nests of bees of the genera Partamona, Scaura and Trigona (Hymenoptera, Apidae) Pólen estocado nos ninhos de abelhas dos gêneros Partamona, Scaura e Trigona (Hymenoptera, Apidae)

    OpenAIRE

    André Rodrigo Rech; Maria Lúcia Absy

    2011-01-01

    Bees and angiosperms established a mutualistic relationship along the evolutionary time. The aim of this study is to contribute for the understanding of this relation analyzing pollen stored by stingless bees colonies distributed along the Rio Negro. Fourteen species of Meliponini from the genera Partamona, Scaura, and Trigona were studied with regard to the content of pollen pots. The pollen material was removed from the pollen pots, homogenized, and prepared according to the usual acetolysi...

  14. Phylogenetic diversification of glycogen synthase kinase 3/SHAGGY-like kinase genes in plants

    Directory of Open Access Journals (Sweden)

    Soltis Pamela S

    2006-02-01

    Full Text Available Abstract Background The glycogen synthase kinase 3 (GSK3/SHAGGY-like kinases (GSKs are non-receptor serine/threonine protein kinases that are involved in a variety of biological processes. In contrast to the two members of the GSK3 family in mammals, plants appear to have a much larger set of divergent GSK genes. Plant GSKs are encoded by a multigene family; analysis of the Arabidopsis genome revealed the existence of 10 GSK genes that fall into four major groups. Here we characterized the structure of Arabidopsis and rice GSK genes and conducted the first broad phylogenetic analysis of the plant GSK gene family, covering a taxonomically diverse array of algal and land plant sequences. Results We found that the structure of GSK genes is generally conserved in Arabidopsis and rice, although we documented examples of exon expansion and intron loss. Our phylogenetic analyses of 139 sequences revealed four major clades of GSK genes that correspond to the four subgroups initially recognized in Arabidopsis. ESTs from basal angiosperms were represented in all four major clades; GSK homologs from the basal angiosperm Persea americana (avocado appeared in all four clades. Gymnosperm sequences occurred in clades I, III, and IV, and a sequence of the red alga Porphyra was sister to all green plant sequences. Conclusion Our results indicate that (1 the plant-specific GSK gene lineage was established early in the history of green plants, (2 plant GSKs began to diversify prior to the origin of extant seed plants, (3 three of the four major clades of GSKs present in Arabidopsis and rice were established early in the evolutionary history of extant seed plants, and (4 diversification into four major clades (as initially reported in Arabidopsis occurred either just prior to the origin of the angiosperms or very early in angiosperm history.

  15. Transcriptome analysis reveals self-incompatibility in the tea plant (Camellia sinensis) might be under gametophytic control

    OpenAIRE

    Zhang, Cheng-Cai; Wang, Li-Yuan; Wei, Kang; Wu, Li-Yun; Li, Hai-Lin; Zhang, Fen; Cheng, Hao; Ni, De-Jiang

    2016-01-01

    Background Self-incompatibility (SI) is under genetic control and prevents inbreeding depression in angiosperms. SI mechanisms are quite complicated and still poorly understood in many plants. Tea (Camellia sinensis L.) belonging to the family of Theaceae, exhibits high levels of SI and high heterozygosity. Uncovering the molecular basis of SI of the tea plant may enhance breeding and simplify genomics research for the whole family. Results The growth of pollen tubes following selfing and cro...

  16. Kin recognition within a seed and the effect of genetic relatedness of an endosperm to its compatriot embryo on maize seed development

    OpenAIRE

    Wu, Chi-Chih; Diggle, Pamela K.; Friedman, William E.

    2013-01-01

    As one of two sexual products resulting from double fertilization in angiosperms, the endosperm nourishes its compatriot embryo during seed development and/or germination and ultimately dies. Theoretical studies suggest that the genetic relatedness of an endosperm to its embryo in the same seed might determine the amount of resources ultimately available for the embryo during seed development. We took advantage of the phenomenon of heterofertilization in cultivated maize to empirically test w...

  17. Three-dimensional geometric morphometrics for studying floral shape variation

    OpenAIRE

    Van der Niet, T; Zollikofer, C P E; Ponce de León, M S; Johnson, S D; H. P. Linder

    2010-01-01

    Variation in floral shape is of major interest to evolutionary and pollination biologists, plant systematists and developmental geneticists. Quantifying this variation has been difficult due to the three-dimensional (3D) complexity of angiosperm flowers. By combining 3D geometric representations of flowers obtained by micro-computed tomography scanning with geometric morphometric methods, well established in zoology and anthropology, floral shape variation can be analyzed quantitatively, allo...

  18. Evolution of the bHLH genes involved in stomatal development: implications for the expansion of developmental complexity of stomata in land plants.

    Directory of Open Access Journals (Sweden)

    Jin-Hua Ran

    Full Text Available Stomata play significant roles in plant evolution. A trio of closely related basic Helix-Loop-Helix (bHLH subgroup Ia genes, SPCH, MUTE and FAMA, mediate sequential steps of stomatal development, and their functions may be conserved in land plants. However, the evolutionary history of the putative SPCH/MUTE/FAMA genes is still greatly controversial, especially the phylogenetic positions of the bHLH Ia members from basal land plants. To better understand the evolutionary pattern and functional diversity of the bHLH genes involved in stomatal development, we made a comprehensive evolutionary analysis of the homologous genes from 54 species representing the major lineages of green plants. The phylogenetic analysis indicated: (1 All bHLH Ia genes from the two basal land plants Physcomitrella and Selaginella were closely related to the FAMA genes of seed plants; and (2 the gymnosperm 'SPCH' genes were sister to a clade comprising the angiosperm SPCH and MUTE genes, while the FAMA genes of gymnosperms and angiosperms had a sister relationship. The revealed phylogenetic relationships are also supported by the distribution of gene structures and previous functional studies. Therefore, we deduce that the function of FAMA might be ancestral in the bHLH Ia subgroup. In addition, the gymnosperm "SPCH" genes may represent an ancestral state and have a dual function of SPCH and MUTE, two genes that could have originated from a duplication event in the common ancestor of angiosperms. Moreover, in angiosperms, SPCHs have experienced more duplications and harbor more copies than MUTEs and FAMAs, which, together with variation of the stomatal development in the entry division, implies that SPCH might have contributed greatly to the diversity of stomatal development. Based on the above, we proposed a model for the correlation between the evolution of stomatal development and the genes involved in this developmental process in land plants.

  19. Coffee Berry Borer Joins Bark Beetles in Coffee Klatch

    OpenAIRE

    Jaramillo, Juliana; Torto, Baldwyn; Mwenda, Dickson; Troeger, Armin; Borgemeister, Christian; Poehling, Hans-Michael; Francke, Wittko

    2013-01-01

    Unanswered key questions in bark beetle-plant interactions concern host finding in species attacking angiosperms in tropical zones and whether management strategies based on chemical signaling used for their conifer-attacking temperate relatives may also be applied in the tropics. We hypothesized that there should be a common link in chemical signaling mediating host location by these Scolytids. Using laboratory behavioral assays and chemical analysis we demonstrate that the yellow-orange exo...

  20. Does size matter? Atmospheric CO2 may be a stronger driver of stomatal closing rate than stomatal size in taxa that diversified under low CO2

    OpenAIRE

    Elliott-Kingston, Caroline; Haworth, Matthew; Yearsley, Jonathan M.; Jennifer C. McElwain; et al.

    2016-01-01

    (1) One strategy for plants to optimise stomatal function is to open and close their stomata quickly in response to environmental signals.  It is generally assumed that small stomata can alter aperture faster than large stomata. (2) We tested the hypothesis that species with small stomata close faster than species with larger stomata in response to darkness by comparing rate of stomatal closure across an evolutionary range of species including ferns, cycads, conifers and angiosperms under con...

  1. Study of Chemical Constituents and Medicinal Uses of Indicator Species of District Bannu

    OpenAIRE

    Rehman ullah khan; Saad Ullah khan; Sultan Mehmood; Ihsan ullah; Aziz Khan

    2013-01-01

    The present study was carried out to assess record and report the chemical constituents and ethnobotanical knowledge of indicator species of District Bannu. Medicinal outlines of about 57 plants were recorded through interview local people i.e. farmers, herbalists, hakims and Medicinal plants user dealers. The present investigation comprises the indigenous uses of 57 species belonging to 36 families of Angiosperms based upon their utility. Out of this rich Medicinal germplasm, 66.15% plants a...

  2. Evolution of GOLDEN2-LIKE gene function in C3 and C4 plants

    OpenAIRE

    Wang, Peng; Fouracre, Jim; Kelly, Steven; Karki, Shanta; Gowik, Udo; Aubry, Sylvain; Shaw, Michael K.; Westhoff, Peter; Slamet-Loedin, Inez H.; Quick, W. Paul; Hibberd, Julian M.; Langdale, Jane A.

    2012-01-01

    A pair of GOLDEN2-LIKE transcription factors is required for normal chloroplast development in land plant species that encompass the range from bryophytes to angiosperms. In the C4 plant maize, compartmentalized function of the two GLK genes in bundle sheath and mesophyll cells regulates dimorphic chloroplast differentiation, whereas in the C3 plants Physcomitrella patens and Arabidopsis thaliana the genes act redundantly in all photosynthetic cells. To assess whether the cell-specific functi...

  3. Evolutionary patterns of volatile terpene emissions across 202 tropical tree species

    OpenAIRE

    Courtois, Elodie A.; Dexter, Kyle G; Paine, Charles Eliot Timothy; Stien, Didier; Engel, Julien; Baraloto, Christopher; Chave, Jérôme

    2015-01-01

    International audience Plant responses to natural enemies include formation of secondary metabolites acting as direct or indirect defenses. Volatile terpenes represent one of the most diverse groups of secondary metabolites. We aimed to explore evolutionary patterns of volatile terpene emission. We measured the composition of damage-induced volatile terpenes from 202 Amazonian tree species, spanning the angiosperm phylogeny. Volatile terpenes were extracted with solid-phase micro extractio...

  4. Root and nodule : lateral organ development in N2-fixing plants

    OpenAIRE

    Xiao, T.T.

    2015-01-01

    Plants are sessile organisms. This characteristic severely limits their ability of approaching nutrients. To cope with this issue, plants evolved endosymbiotic relationships with soil fungi to extend their interface with surrounding environment. In case of arbuscular mycorrhizae (AM) fungi this occurred about 400 million years ago. The AM fungi can interact with most angiosperms. In this symbiotic relationship, the plant get nutrients, especially phosphate, from the fungi, and plants provide ...

  5. Moss cell walls: structure and biosynthesis

    OpenAIRE

    Alison W. Roberts; Eric M Roberts; Haigler, Candace H.

    2012-01-01

    The genome sequence of the moss Physcomitrella patens has stimulated new research examining the cell wall polysaccharides of mosses and the glycosyl transferases that synthesize them as a means to understand fundamental processes of cell wall biosynthesis and plant cell wall evolution. The cell walls of mosses and vascular plants are composed of the same classes of polysaccharides, but with differences in side chain composition and structure. Similarly, the genomes of P. patens and angiosperm...

  6. Deceptive pollination of orchids

    OpenAIRE

    Zongxin Ren; Hong Wang; Yibo Luo

    2012-01-01

    Mutualism, or a mutually beneficial interaction between two organisms, are ubiquitous in ecological systems. However, some “empty flowers”, which offer pollinators no any kinds of rewards, design different strategies to attract pollinators without providing rewards to the pollinators. These pollination mechanisms are called deceptive pollination. The family Orchidaceae, representing one of the largest groups in angiosperms, is distinguished by high floral diversity and intricate adaptations t...

  7. Cretaceous environmental changes led to high extinction rates in a hyperdiverse beetle family : Cretaceous environmental changes led to high extinction rates in a hyperdiverse beetle family

    OpenAIRE

    Kergoat, Gael; Bouchard, Patrice; Clamens, Anne Laure; Abbate, Jessica L.; Jourdan, Herve; JABBOUR-ZAHAB, ROULA; Genson, Guénaëlle; Soldati, Laurent; Condamine, Fabien L.

    2014-01-01

    Background As attested by the fossil record, Cretaceous environmental changes have significantly impacted the diversification dynamics of several groups of organisms. A major biome turnover that occurred during this period was the rise of angiosperms starting ca. 125 million years ago. Though there is evidence that the latter promoted the diversification of phytophagous insects, the response of other insect groups to Cretaceous environmental changes is still largely unknown. To gain novel ins...

  8. Late Paleocene fossils from the Cerrejón Formation, Colombia, are the earliest record of Neotropical rainforest

    OpenAIRE

    Wing, Scott L.; Herrera, Fabiany; Jaramillo, Carlos A.; Gómez-Navarro, Carolina; Wilf, Peter; Labandeira, Conrad C.

    2009-01-01

    Neotropical rainforests have a very poor fossil record, making hypotheses concerning their origins difficult to evaluate. Nevertheless, some of their most important characteristics can be preserved in the fossil record: high plant diversity, dominance by a distinctive combination of angiosperm families, a preponderance of plant species with large, smooth-margined leaves, and evidence for a high diversity of herbivorous insects. Here, we report on an ≈58-my-old flora from the Cerrejón Formatio...

  9. Wing Shape of Four New Bee Fossils (Hymenoptera: Anthophila) Provides Insights to Bee Evolution

    OpenAIRE

    Dehon, Manuel; Michez, Denis; Nel, André; Engel, Michael S.; De Meulemeester, Thibaut

    2014-01-01

    Bees (Anthophila) are one of the major groups of angiosperm-pollinating insects and accordingly are widely studied in both basic and applied research, for which it is essential to have a clear understanding of their phylogeny, and evolutionary history. Direct evidence of bee evolutionary history has been hindered by a dearth of available fossils needed to determine the timing and tempo of their diversification, as well as episodes of extinction. Here we describe four new compression fossils o...

  10. Pollination of Polish red list plants: a preliminary statistical survey

    OpenAIRE

    Marcin Zych; Andrzej Jakubiec

    2012-01-01

    One of the important problems of modern conservation biology is the lack of reliable data on plant pollination systems, especially for taxa threatened with extinction. This paper is an attempt to collect and analyze the available literature data on pollination of Polish red list plants. The Polish red list includes 469 angiosperm taxa, over 53% of them are insect-pollinated and visited mostly by bees and flies, insects that are also declining in Europe. These numbers however are mainly based ...

  11. Flower colour adaptation in a mimetic orchid

    OpenAIRE

    Newman, Ethan; Anderson, Bruce; JOHNSON, STEVEN D.

    2012-01-01

    Although the tremendous variability in floral colour among angiosperms is often attributed to divergent selection by pollinators, it is usually difficult to preclude the possibility that floral colour shifts were driven by non-pollinator processes. Here, we examine the adaptive significance of flower colour in Disa ferruginea, a non-rewarding orchid that is thought to attract its butterfly pollinator by mimicking the flowers of sympatric nectar-producing species. Disa ferruginea has red flowe...

  12. Flowers and sexes in Malaysian seagrasses

    OpenAIRE

    Japar Sidik Bujang; Muta Harah, Zakaria; Aziz , Arshad; Shiau Lee, Lam; Ogawa, Hisao

    2006-01-01

    Seagrasses are aquatic angiosperms growing in shallow coastal waters, although some species are found in deep waters. Similar to higher plants in terrestrial ecosystems, seagrasses are also flowering plants. Structurally, seagrass flowers are less complex and adapted for hydrophilous pollination and fertilization. Two modes of propagation typical of seagrasses are vegetative and sexual propagation. Vegetative propagation allows increase in ramet numbers and hence covers, while sexual reproduc...

  13. Attract them anyway: benefits of large, showy flowers in a highly autogamous, carnivorous plant species

    OpenAIRE

    Salces-Castellano, A.; Paniw, M.; Casimiro-Soriguer, R.; Ojeda, F.

    2016-01-01

    Reproductive biology of carnivorous plants has largely been studied on species that rely on insects as pollinators and prey, creating potential conflicts. Autogamous pollination, although present in some carnivorous species, has received less attention. In angiosperms, autogamous self-fertilization is expected to lead to a reduction in flower size, thereby reducing resource allocation to structures that attract pollinators. A notable exception is the carnivorous pyrophyte Drosophyllum lusitan...

  14. Influence of polyploidy on insect herbivores of native and invasive genotypes of Solidago gigantea (Asteraceae)

    OpenAIRE

    Helen M. Hull-Sanders; Johnson, Robert H.; Owen, Heather A.; Meyer, Gretchen A.

    2009-01-01

    Herbivores are sensitive to the genetic structure of plant populations, as genetics underlies plant phenotype and host quality. Polyploidy is a widespread feature of angiosperm genomes, yet few studies have examined how polyploidy influences herbivores. Introduction to new ranges, with consequent changes in selective regimes, can lead to evolution of changes in plant defensive characteristics and also affect herbivores. Here, we examine how insect herbivores respond to polyploidy in Solidago ...

  15. The importance of floral signals in the establishment of plant-ant mutualisms

    OpenAIRE

    Vega, Clara de

    2009-01-01

    Visual and olfactory floral signals are essential for the establishment of plant-pollinator mutualisms. Different batteries of floral features attract different pollinators and may achieve specific relationships that are essential for the immediate plant reproductive success, and at an evolutionary time scale have been of vital importance in the radiation of Angiosperms. We have found that mutualistic services by ants, insects traditionally considered ineffective pollinators, are essential fo...

  16. De Novo Sequencing, Assembly, and Analysis of the Root Transcriptome of Persea americana (Mill.) in Response to Phytophthora cinnamomi and Flooding

    OpenAIRE

    Reeksting, Bianca J.; Coetzer, Nanette; Mahomed, Waheed; Engelbrecht, Juanita; van den Berg, Noëlani

    2014-01-01

    Avocado is a diploid angiosperm containing 24 chromosomes with a genome estimated to be around 920 Mb. It is an important fruit crop worldwide but is susceptible to a root rot caused by the ubiquitous oomycete Phytophthora cinnamomi. Phytophthora root rot (PRR) causes damage to the feeder roots of trees, causing necrosis. This leads to branch-dieback and eventual tree death, resulting in severe losses in production. Control strategies are limited and at present an integrated approach involvin...

  17. Occurrence and palaeoenvironmental significance of aromatic hydrocarbon biomarkers in Oligocene sediments from the Mallik 5L-38 Gas Hydrate Production Research Well (Canada)

    Energy Technology Data Exchange (ETDEWEB)

    Haberer, R.M.; Mangelsdorf, K.; Wilkes, H.; Horsfield, B. [Geoforschungszentrum Potsdam, Potsdam (Germany)

    2006-07-01

    The aromatic hydrocarbon biomarker distributions of thirty Oligocene sediment samples with different lithology (lignite, clay and sand) from the JAPEX/JNOC/GSC et al. Mallik 5L-38 Gas Hydrate Production Research Well, Canada, were analyzed using gas chromatography-mass spectrometry (GC-MS). The compositions vary with lithology, indicating a change in palaeoenvironmental conditions at the time of deposition. Aromatic diterpenoids of the abietane type are more abundant in the lignite samples than in the clay samples and represent a gymnosperm (e.g., conifer) dominated palaeovegetation. In contrast, in the clay samples aromatic triterpenoids are generally preserved as major constituents, indicating angiosperm dominated vegetation. The sand samples contain only minor amounts of aromatic terpenoids, but show a preference for diterpenoid gymnosperm markers. To recognise gymnosperm versus angiosperm dominated palaeoenvironments a new ratio, termed the angiosperm-gymnosperm aromatic ratio (AGAR), has been developed. Thus, the terpenoid distribution in the deltaic sediments provides information on the compositional changes in the plant community at the Mallik site (lignites) and the hinterland (clays) over time. Concomitantly, the changing dominance in the plant communities allows an insight into varying climatic conditions during the late Oligocene in the area.

  18. Repeated, recent and diverse transfers of a mitochondrial gene to the nucleus in flowering plants.

    Science.gov (United States)

    Adams, K L; Daley, D O; Qiu, Y L; Whelan, J; Palmer, J D

    2000-11-16

    A central component of the endosymbiotic theory for the bacterial origin of the mitochondrion is that many of its genes were transferred to the nucleus. Most of this transfer occurred early in mitochondrial evolution; functional transfer of mitochondrial genes has ceased in animals. Although mitochondrial gene transfer continues to occur in plants, no comprehensive study of the frequency and timing of transfers during plant evolution has been conducted. Here we report frequent loss (26 times) and transfer to the nucleus of the mitochondrial gene rps10 among 277 diverse angiosperms. Characterization of nuclear rps10 genes from 16 out of 26 loss lineages implies that many independent, RNA-mediated rps10 transfers occurred during recent angiosperm evolution; each of the genes may represent a separate functional gene transfer. Thus, rps10 has been transferred to the nucleus at a surprisingly high rate during angiosperm evolution. The structures of several nuclear rps10 genes reveal diverse mechanisms by which transferred genes become activated, including parasitism of pre-existing nuclear genes for mitochondrial or cytoplasmic proteins, and activation without gain of a mitochondrial targeting sequence. PMID:11099041

  19. Phylogenetic and Genomic Analyses Resolve the Origin of Important Plant Genes Derived from Transposable Elements.

    Science.gov (United States)

    Joly-Lopez, Zoé; Hoen, Douglas R; Blanchette, Mathieu; Bureau, Thomas E

    2016-08-01

    Once perceived as merely selfish, transposable elements (TEs) are now recognized as potent agents of adaptation. One way TEs contribute to evolution is through TE exaptation, a process whereby TEs, which persist by replicating in the genome, transform into novel host genes, which persist by conferring phenotypic benefits. Known exapted TEs (ETEs) contribute diverse and vital functions, and may facilitate punctuated equilibrium, yet little is known about this process. To better understand TE exaptation, we designed an approach to resolve the phylogenetic context and timing of exaptation events and subsequent patterns of ETE diversification. Starting with known ETEs, we search in diverse genomes for basal ETEs and closely related TEs, carefully curate the numerous candidate sequences, and infer detailed phylogenies. To distinguish TEs from ETEs, we also weigh several key genomic characteristics including repetitiveness, terminal repeats, pseudogenic features, and conserved domains. Applying this approach to the well-characterized plant ETEs MUG and FHY3, we show that each group is paraphyletic and we argue that this pattern demonstrates that each originated in not one but multiple exaptation events. These exaptations and subsequent ETE diversification occurred throughout angiosperm evolution including the crown group expansion, the angiosperm radiation, and the primitive evolution of angiosperms. In addition, we detect evidence of several putative novel ETE families. Our findings support the hypothesis that TE exaptation generates novel genes more frequently than is currently thought, often coinciding with key periods of evolution. PMID:27189548

  20. Diversity in neotropical wet forests during the Cenozoic is linked more to atmospheric CO2 than temperature.

    Science.gov (United States)

    Royer, Dana L; Chernoff, Barry

    2013-08-01

    Models generally predict a response in species richness to climate, but strong climate-diversity associations are seldom observed in long-term (more than 10(6) years) fossil records. Moreover, fossil studies rarely distinguish between the effects of atmospheric CO2 and temperature, which limits their ability to identify the causal controls on biodiversity. Plants are excellent organisms for testing climate-diversity hypotheses owing to their strong sensitivity to CO2, temperature and moisture. We find that pollen morphospecies richness in an angiosperm-dominated record from the Palaeogene and early Neogene (65-20 Ma) of Colombia and Venezuela correlates positively to CO2 much more strongly than to temperature (both tropical sea surface temperatures and estimates of global mean surface temperature). The weaker sensitivity to temperature may be due to reduced variance in long-term climate relative to in higher latitudes, or to the occurrence of lethal or sub-lethal temperatures during the warmest times of the Eocene. Physiological models predict that productivity should be the most sensitive to CO2 within the angiosperms, a prediction supported by our analyses if productivity is linked to species richness; however, evaluations of non-angiosperm assemblages are needed to more completely test this idea. PMID:23760866

  1. Interannual variation and host affiliations of endophytic fungi associated with ferns at La Selva, Costa Rica.

    Science.gov (United States)

    Del Olmo-Ruiz, Mariana; Arnold, A Elizabeth

    2014-01-01

    Ferns are an ancient and diverse lineage of vascular plants that differ morphologically, chemically and in growth habits from the angiosperms with which they co-occur. We used a culture-based approach coupled with phylogenetic analyses to characterize the incidence, diversity and composition of fungal endophyte assemblages in ferns, with a focus on healthy aboveground tissues of seven species of eupolypods at La Selva, Costa Rica. Endophytes were isolated from every individual plant and were similarly abundant and diverse in frond blades and stalks, in different vegetation types, in epiphytic vs. terrestrial species, and between sampling years. However, abundance, diversity and community structure differed significantly among fern species, and composition differed markedly between sampling years. Phylogenetic classification using separate and combined datasets revealed that as for many Neotropical angiosperms, the majority (95%) of endophyte taxa were Ascomycota, with particular dominance by Sordariomycetes, Eurotiomycetes and Dothideomycetes. However, our data suggest higher phylogenetic richness and stronger host affinities in fern associated endophytes relative to those studied in angiosperms thus far. PMID:24459121

  2. Evolution of fruit types and seed dispersal: A phylogenetic and ecological snapshot%果实类型和种子传播的进化:系统发育和生态学简论

    Institute of Scientific and Technical Information of China (English)

    Claire M. LORTS; Trevor BRIGGEMAN; 桑涛

    2008-01-01

    Success of flowering plants is greatly dependent on effective seed dispersal. Specific fruit types aid different mechanisms of seed dispersal. However, little is known about what evolutionary forces have driven the diversification of fruit types and whether there were phylogenetic constraints on fruit evolution among angiosperm lineages. To address these questions, we first surveyed the orders and families of angiosperms for fruit types and found no clear association between fruit types and major angiosperm lineages, suggesting there was little phylogenetic constraint on fruit evolution at this level. We then surveyed fruit types found in two contrasting habitats: an open habitat including the Indian desert and North American plains and prairies, and a closed forest habitat of Australian tropical forest. The majority of genera in the survey of tropical forests in Australia were fleshy fruit trees, whereas the majority of genera in the survey of prairies and plains in central North America were herbs with capsules and achenes. Both capsules and achenes are frequently dispersed by wind in the open, arid habitat, whereas fleshy fruits are generally dispersed by animals. Since desert and plains tend to provide continuous wind to aid dispersal and there are more abundant mammal and bird dispersers in the closed forest, this survey suggests that fruit evolution was driven at least in part by dispersal agents abundant in particular habitats.

  3. Floristic and phytosociological analysis of palm swamps in the central part of the Brazilian savanna

    Directory of Open Access Journals (Sweden)

    Isa Lucia de Morais Resende

    2013-03-01

    Full Text Available We analyzed the floristics and phytosociology of three palm swamps in the municipality of Bela Vista de Goiás, located in the state of Goiás, Brazil, in the central part of the Brazilian savanna (Cerrado. The floristic surveys were conducted monthly from May 2008 to April 2009, and 310 species were recorded (seven bryophytes, 15 ferns and 288 angiosperms. Bryophytes belonged to five genera and five families; ferns belonged to nine genera and nine families; and angiosperms belonged to 134 genera and 45 families. The angiosperm families with the highest species richness were Poaceae, Cyperaceae, Asteraceae, Eriocaulaceae, Xyridaceae, Lentibulariaceae, Melastomataceae, Rubiaceae and Fabaceae. The palm swamps were divided into three zones of increasing humidity: edge, middle and core. The number of species was higher in the middle than at the edge and the core. The families with the highest cover values were Cyperaceae, Melastomataceae, Arecaceae and Poaceae. Although the palm swamps had been disturbed to varying degrees, those disturbances did not affect the flora in the middle or the core. Floristic similarity was high between these two zones within a given palm swamp and low between the edges of different palm swamps.

  4. A Transcriptome Atlas of Physcomitrella patens Provides Insights into the Evolution and Development of Land Plants.

    Science.gov (United States)

    Ortiz-Ramírez, Carlos; Hernandez-Coronado, Marcela; Thamm, Anna; Catarino, Bruno; Wang, Mingyi; Dolan, Liam; Feijó, José A; Becker, Jörg D

    2016-02-01

    Identifying the genetic mechanisms that underpin the evolution of new organ and tissue systems is an aim of evolutionary developmental biology. Comparative functional genetic studies between angiosperms and bryophytes can define those genetic changes that were responsible for developmental innovations. Here, we report the generation of a transcriptome atlas covering most phases in the life cycle of the model bryophyte Physcomitrella patens, including detailed sporophyte developmental progression. We identified a comprehensive set of sporophyte-specific transcription factors, and found that many of these genes have homologs in angiosperms that function in developmental processes such as flowering and shoot branching. Deletion of the PpTCP5 transcription factor results in development of supernumerary sporangia attached to a single seta, suggesting that it negatively regulates branching in the moss sporophyte. Given that TCP genes repress branching in angiosperms, we suggest that this activity is ancient. Finally, comparison of P. patens and Arabidopsis thaliana transcriptomes led us to the identification of a conserved core of transcription factors expressed in tip-growing cells. We identified modifications in the expression patterns of these genes that could account for developmental differences between P. patens tip-growing cells and A. thaliana pollen tubes and root hairs. PMID:26687813

  5. Riverine Dissolved Organic Matter Degradation Modeled Through Microbial Incubations of Vascular Plant Leachates

    Science.gov (United States)

    Harfmann, J.; Hernes, P.; Chuang, C. Y.

    2015-12-01

    Dissolved organic matter (DOM) contains as much carbon as is in the atmosphere, provides the main link between terrestrial and marine carbon reservoirs, and fuels the microbial food web. The fate and removal of DOM is a result of several complex conditions and processes, including photodegradation, sorption/desorption, dominant vascular plant sources, and microbial abundance. In order to better constrain factors affecting microbial degradation, laboratory incubations were performed using Sacramento River water for microbial inoculums and vascular plant leachates. Four vascular plant sources were chosen based on their dominance in the Sacramento River Valley: gymnosperm needles from Pinus sabiniana (foothill pine), angiosperm dicot leaves from Quercus douglassi (blue oak), angiosperm monocot mixed annual grasses, and angiosperm monocot mixed Schoenoplectus acutus (tule) and Typha spp. (cattails). Three concentrations of microbial inoculum were used for each plant material, ranging from 0.2% to 10%. Degradation was monitored as a function of time using dissolved organic carbon (DOC), UV-Vis absorbance, and fluorescent dissolved organic matter (fDOM), and was compared across vascular plant type and inoculum concentration.

  6. Expression divergence of the AGL6 MADS domain transcription factor lineage after a core eudicot duplication suggests functional diversification

    Directory of Open Access Journals (Sweden)

    Melzer Siegbert

    2010-07-01

    Full Text Available Abstract Background Because of their known role as transcriptional regulators of key plant developmental processes, the diversification of MADS-box gene function is thought to be a major driving force in the developmental evolution of plants. Yet the function of some MADS-box gene subfamilies has remained elusive thus far. One such lineage, AGL6, has now been functionally characterized in three angiosperm species, but a phylogenetic framework for comparison of AGL6 gene function is currently missing. Results Based on phylogenetic analyses of newly isolated and EST-based sequences, we describe the duplication history of the AGL6 subfamily in angiosperms. Our analyses provide support for four ancient duplications in the evolution of the AGL6 lineage: one at the base of core eudicots resulting in euAGL6 and AGL6-like gene clades, one during basal angiosperm diversification and two in monocot evolution. To investigate whether the spatial domains in which AGL6 genes function have diverged after duplication, we use quantitative Real Time PCR. We show that the core eudicot AGL6-like clade acquired expression in vegetative tissues, while its paralog euAGL6 remains predominantly confined to reproductive tissues. Conclusions These and previous data lead us to propose that the AGL6 lineage in core eudicots, in addition to functions related to the expression in reproductive structures, may have acquired a function in developmental transitions of vegetative shoots.

  7. Identification of proteins enriched in rice egg or sperm cells by single-cell proteomics.

    Directory of Open Access Journals (Sweden)

    Mafumi Abiko

    Full Text Available In angiosperms, female gamete differentiation, fertilization, and subsequent zygotic development occur in embryo sacs deeply embedded in the ovaries. Despite their importance in plant reproduction and development, how the egg cell is specialized, fuses with the sperm cell, and converts into an active zygote for early embryogenesis remains unclear. This lack of knowledge is partly attributable to the difficulty of direct analyses of gametes in angiosperms. In the present study, proteins from egg and sperm cells obtained from rice flowers were separated by one-dimensional polyacrylamide gel electrophoresis and globally identified by highly sensitive liquid chromatography coupled with tandem mass spectroscopy. Proteome analyses were also conducted for seedlings, callus, and pollen grains to compare their protein expression profiles to those of gametes. The proteomics data have been deposited to the ProteomeXchange with identifier PXD000265. A total of 2,138 and 2,179 expressed proteins were detected in egg and sperm cells, respectively, and 102 and 77 proteins were identified as preferentially expressed in egg and sperm cells, respectively. Moreover, several rice or Arabidopsis lines with mutations in genes encoding the putative gamete-enriched proteins showed clear phenotypic defects in seed set or seed development. These results suggested that the proteomic data presented in this study are foundational information toward understanding the mechanisms of reproduction and early development in angiosperms.

  8. Telomere-centric genome repatterning determines recurring chromosome number reductions during the evolution of eukaryotes.

    Science.gov (United States)

    Wang, Xiyin; Jin, Dianchuan; Wang, Zhenyi; Guo, Hui; Zhang, Lan; Wang, Li; Li, Jingping; Paterson, Andrew H

    2015-01-01

    Whole-genome duplication (WGD) is central to the evolution of many eukaryotic genomes, in particular rendering angiosperm (flowering plant) genomes much less stable than those of animals. Following repeated duplication/triplication(s), angiosperm chromosome numbers have usually been restored to a narrow range, as one element in a 'diploidization' process that re-establishes diploid heredity. In several angiosperms affected by WGD, we show that chromosome number reduction (CNR) is best explained by intra- and/or inter-chromosomal crossovers to form new chromosomes that utilize the existing telomeres of 'invaded' and centromeres of 'invading' chromosomes, the alternative centromeres and telomeres being lost. Comparison with the banana (Musa acuminata) genome supports a 'fusion model' for the evolution of rice (Oryza sativa) chromosomes 2 and 3, implying that the grass common ancestor had seven chromosomes rather than the five implied by a 'fission model.' The 'invading' and 'invaded' chromosomes are frequently homoeologs, originating from duplication of a common ancestral chromosome and with greater-than-average DNA-level correspondence to one another. Telomere-centric CNR following recursive WGD in plants is also important in mammals and yeast, and may be a general mechanism of restoring small linear chromosome numbers in higher eukaryotes. PMID:25138576

  9. Differential expression of the two types of histone H2A genes in wheat.

    Science.gov (United States)

    Huh, G H; Matsuura, Y; Meshi, T; Iwabuchi, M

    1995-03-14

    Five histone H2A cDNA clones have been isolated from a wheat cDNA library. They were divided into two groups, termed type 1 and type 2, based on their deduced amino acid sequences and their gene expression patterns. Three type 1 clones had ORFs encoding proteins similar to angiosperm histone H2As known so far, whereas two type 2 clones encoded an identical protein, which was more similar to Norway spruce (gymnosperm) H2A than to the angiosperm H2As. The C-terminus of the type 2 H2A was shorter than that of the type 1 H2As and lacked the characteristic SPKK motif that is conserved in angiosperm H2As. Northern analysis revealed that the mRNA levels of the type 1 H2A genes were high in proliferating cells during germination and in various tissues of young seedlings, while the mRNA levels of the type 2 genes were high in non-proliferating cells in which the type 1 gene was poorly expressed. This result suggests that the expression of these two groups of H2A genes is differently regulated during development in wheat. PMID:7893754

  10. Pollen tube development in two species of Trithuria (Hydatellaceae) with contrasting breeding systems.

    Science.gov (United States)

    Taylor, Mackenzie L; Williams, Joseph H

    2012-06-01

    Trithuria (Hydatellaceae; Nymphaeales) is unique among early-divergent angiosperms in that its species are extremely small and most have exceptionally short, annual life histories. Given the evolution of these extremes of size and development, we sought to understand whether post-pollination processes still varied predictably with breeding system in Trithuria. To address this question, we studied two Western Australian species, Trithuria austinensis (dioecious, obligately outcrossing) and Trithuria submersa (bisexual, highly selfing). To document developmental timing, carpels were hand-pollinated, collected at sequential time points, and examined with light and fluorescence microscopy. In both species, pollen tubes first entered ovulespollination, but the pollen tube pathway of outcrossing T. austinensis was almost four times longer and its pollen tube growth rates were up to six times faster (≤2,166 vs. 321 μm/h) than those of T. submersa. T. austinensis also exhibited greater male investment, slower pollen germination, and greater pollen tube attrition. These differences in male gametophyte development are predicted for outcrossers versus selfers in phylogenetically derived angiosperms. These new data for Hydatellaceae reinforce the idea that an acceleration of pollen tube development occurred in the Nymphaeales stem lineage, before the origin of Hydatellaceae. We infer that a recent evolutionary transition to selfing in T. submersa has been accompanied by predictable modifications to reproductive development, which, because of the ancient relationship between Hydatellaceae and all other angiosperms, suggests that traits underlying the lability of flowering plant post-pollination biology were present early in their history. PMID:22367232

  11. Extending the generality of leaf economic design principles in the cycads, an ancient lineage.

    Science.gov (United States)

    Zhang, Yong-Jiang; Cao, Kun-Fang; Sack, Lawren; Li, Nan; Wei, Xue-Mei; Goldstein, Guillermo

    2015-04-01

    Cycads are the most ancient lineage of living seed plants, but the design of their leaves has received little study. We tested whether cycad leaves are governed by the same fundamental design principles previously established for ferns, conifers and angiosperms, and characterized the uniqueness of this relict lineage in foliar trait relationships. Leaf structure, photosynthesis, hydraulics and nutrient composition were studied in 33 cycad species from nine genera and three families growing in two botanical gardens. Cycads varied greatly in leaf structure and physiology. Similarly to other lineages, light-saturated photosynthetic rate per mass (Am ) was related negatively to leaf mass per area and positively to foliar concentrations of chlorophyll, nitrogen (N), phosphorus and iron, but unlike angiosperms, leaf photosynthetic rate was not associated with leaf hydraulic conductance. Cycads had lower photosynthetic N use efficiency and higher photosynthetic performance relative to hydraulic capacity compared with other lineages. These findings extend the relationships shown for foliar traits in angiosperms to the cycads. This functional convergence supports the modern synthetic understanding of leaf design, with common constraints operating across lineages, even as they highlight exceptional aspects of the biology of this key relict lineage. PMID:25622799

  12. A brief history of fruits and frugivores

    Science.gov (United States)

    Fleming, Theodore H.; John Kress, W.

    2011-11-01

    In this paper we briefly review the evolutionary history of the mutualistic interaction between angiosperms that produce fleshy fruits and their major consumers: frugivorous birds and mammals. Fleshy fruits eaten by these vertebrates are widely distributed throughout angiosperm phylogeny. Similarly, a frugivorous diet has evolved independently many times in birds and mammals. Bird dispersal is more common than mammal-dispersal in all lineages of angiosperms, and we suggest that the evolution of bird fruits may have facilitated the evolution of frugivory in primates. The diets of fruit-eating bats overlap less with those of other kinds of frugivorous vertebrates. With a few exceptions, most families producing vertebrate-dispersed fruit appeared substantially earlier in earth history than families of their vertebrate consumers. It is likely that major radiations of these plants and animals have occurred in the past 30 Ma, in part driven by geological changes and also by the foraging behavior of frugivores in topographically complex landscapes. Overall, this mutualistic interaction has had many evolutionary and ecological consequences for tropical plants and animals for most of the Cenozoic Era. Loss of frugivores and their dispersal services will have a strong negative impact on the ecological and evolutionary dynamics of tropical and subtropical communities.

  13. A functional phylogenomic view of the seed plants.

    Directory of Open Access Journals (Sweden)

    Ernest K Lee

    2011-12-01

    Full Text Available A novel result of the current research is the development and implementation of a unique functional phylogenomic approach that explores the genomic origins of seed plant diversification. We first use 22,833 sets of orthologs from the nuclear genomes of 101 genera across land plants to reconstruct their phylogenetic relationships. One of the more salient results is the resolution of some enigmatic relationships in seed plant phylogeny, such as the placement of Gnetales as sister to the rest of the gymnosperms. In using this novel phylogenomic approach, we were also able to identify overrepresented functional gene ontology categories in genes that provide positive branch support for major nodes prompting new hypotheses for genes associated with the diversification of angiosperms. For example, RNA interference (RNAi has played a significant role in the divergence of monocots from other angiosperms, which has experimental support in Arabidopsis and rice. This analysis also implied that the second largest subunit of RNA polymerase IV and V (NRPD2 played a prominent role in the divergence of gymnosperms. This hypothesis is supported by the lack of 24nt siRNA in conifers, the maternal control of small RNA in the seeds of flowering plants, and the emergence of double fertilization in angiosperms. Our approach takes advantage of genomic data to define orthologs, reconstruct relationships, and narrow down candidate genes involved in plant evolution within a phylogenomic view of species' diversification.

  14. Plants, Weathering, and the Evolution of Atmospheric Carbon Dioxide and Oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Berner, Robert A

    2008-02-05

    Over the past six years we have published 24 papers that can be divided into three sections: (1) Study of plants and weathering, (2) modeling the evolution of atmospheric CO2 over Phanerozoic time (past 550 million years). (3) Modeling of atmospheric O2 over Phanerozoic time. References to papers published acknowledging this grant can be found at the end of this report and almost all are supplied in pdf form. (1) In the temperate forests of the Cascade Mountains, USA, calcium and magnesium meet vastly different fates beneath angiosperms vs gymnosperms. Calcium is leached beneath both groves of trees, but leached 20-40% more beneath the angiosperms. Magnesium is retained in the forest system beneath the angiosperms and leached from beneath the gymnosperms. (2) We have shown that climate and CO2, based on both carbon cycle modeling and hundreds of independent proxies for paleo-CO2, correlate very well over the past 550 million year. In a recent paper we use this correlation to deduce the sensitivity of global mean temperature to a doubling of atmospheric CO2, and results are in excellent agreement with the results of climatologists based on the historical record and on theoretical climate models (GCM’s).(3) We have shown that concentrations of atmospheric oxygen, calculated by a combined carbon-sulfur cycle model, over the past 550 million years have varied with and influenced biological evolution.

  15. Evolution of tonoplast P-ATPase transporters involved in vacuolar acidification.

    Science.gov (United States)

    Li, Yanbang; Provenzano, Sofia; Bliek, Mattijs; Spelt, Cornelis; Appelhagen, Ingo; Machado de Faria, Laura; Verweij, Walter; Schubert, Andrea; Sagasser, Martin; Seidel, Thorsten; Weisshaar, Bernd; Koes, Ronald; Quattrocchio, Francesca

    2016-08-01

    Petunia mutants (Petunia hybrida) with blue flowers defined a novel vacuolar proton pump consisting of two interacting P-ATPases, PH1 and PH5, that hyper-acidify the vacuoles of petal cells. PH5 is similar to plasma membrane H(+) P3A -ATPase, whereas PH1 is the only known eukaryoticP3B -ATPase. As there were no indications that this tonoplast pump is widespread in plants, we investigated the distribution and evolution of PH1 and PH5. We combined database mining and phylogenetic and synteny analyses of PH1- and PH5-like proteins from all kingdoms with functional analyses (mutant complementation and intracellular localization) of homologs from diverse angiosperms. We identified functional PH1 and PH5 homologs in divergent angiosperms. PH5 homologs evolved from plasma membrane P3A -ATPases, acquiring an N-terminal tonoplast-sorting sequence and new cellular function before angiosperms appeared. PH1 is widespread among seed plants and related proteins are found in some groups of bacteria and fungi and in one moss, but is absent in most algae, suggesting that its evolution involved several cases of gene loss and possibly horizontal transfer events. The distribution of PH1 and PH5 in the plant kingdom suggests that vacuolar acidification by P-ATPases appeared in gymnosperms before flowers. This implies that, next to flower color determination, vacuolar hyper-acidification is required for yet unknown processes. PMID:27214749

  16. Evolution of plant senescence

    Directory of Open Access Journals (Sweden)

    Young Mike

    2009-07-01

    Full Text Available Abstract Background Senescence is integral to the flowering plant life-cycle. Senescence-like processes occur also in non-angiosperm land plants, algae and photosynthetic prokaryotes. Increasing numbers of genes have been assigned functions in the regulation and execution of angiosperm senescence. At the same time there has been a large expansion in the number and taxonomic spread of plant sequences in the genome databases. The present paper uses these resources to make a study of the evolutionary origins of angiosperm senescence based on a survey of the distribution, across plant and microbial taxa, and expression of senescence-related genes. Results Phylogeny analyses were carried out on protein sequences corresponding to genes with demonstrated functions in angiosperm senescence. They include proteins involved in chlorophyll catabolism and its control, homeoprotein transcription factors, metabolite transporters, enzymes and regulators of carotenoid metabolism and of anthocyanin biosynthesis. Evolutionary timelines for the origins and functions of particular genes were inferred from the taxonomic distribution of sequences homologous to those of angiosperm senescence-related proteins. Turnover of the light energy transduction apparatus is the most ancient element in the senescence syndrome. By contrast, the association of phenylpropanoid metabolism with senescence, and integration of senescence with development and adaptation mediated by transcription factors, are relatively recent innovations of land plants. An extended range of senescence-related genes of Arabidopsis was profiled for coexpression patterns and developmental relationships and revealed a clear carotenoid metabolism grouping, coordinated expression of genes for anthocyanin and flavonoid enzymes and regulators and a cluster pattern of genes for chlorophyll catabolism consistent with functional and evolutionary features of the pathway. Conclusion The expression and phylogenetic

  17. Developmental evolution of flowering plant pollen tube cell walls: callose synthase (CalS gene expression patterns

    Directory of Open Access Journals (Sweden)

    Abercrombie Jason M

    2011-07-01

    Full Text Available Abstract Background A number of innovations underlie the origin of rapid reproductive cycles in angiosperms. A critical early step involved the modification of an ancestrally short and slow-growing pollen tube for faster and longer distance transport of sperm to egg. Associated with this shift are the predominantly callose (1,3-β-glucan walls and septae (callose plugs of angiosperm pollen tubes. Callose synthesis is mediated by callose synthase (CalS. Of 12 CalS gene family members in Arabidopsis, only one (CalS5 has been directly linked to pollen tube callose. CalS5 orthologues are present in several monocot and eudicot genomes, but little is known about the evolutionary origin of CalS5 or what its ancestral function may have been. Results We investigated expression of CalS in pollen and pollen tubes of selected non-flowering seed plants (gymnosperms and angiosperms within lineages that diverged below the monocot/eudicot node. First, we determined the nearly full length coding sequence of a CalS5 orthologue from Cabomba caroliniana (CcCalS5 (Nymphaeales. Semi-quantitative RT-PCR demonstrated low CcCalS5 expression within several vegetative tissues, but strong expression in mature pollen. CalS transcripts were detected in pollen tubes of several species within Nymphaeales and Austrobaileyales, and comparative analyses with a phylogenetically diverse group of sequenced genomes indicated homology to CalS5. We also report in silico evidence of a putative CalS5 orthologue from Amborella. Among gymnosperms, CalS5 transcripts were recovered from germinating pollen of Gnetum and Ginkgo, but a novel CalS paralog was instead amplified from germinating pollen of Pinus taeda. Conclusion The finding that CalS5 is the predominant callose synthase in pollen tubes of both early-diverging and model system angiosperms is an indicator of the homology of their novel callosic pollen tube walls and callose plugs. The data suggest that CalS5 had transient expression

  18. Behavior of Sr-90 and transuranic elements in three areas in Finland

    International Nuclear Information System (INIS)

    The study was carried out in three areas (both terrestrial and aquatic): in the Maenttae area in Central Finland and in the environs of the Loviisa and Olkiluoto Nuclear Power Plants. The highest Sr-90 concentrations were found in Ebilobium angustifolium, being 70 - 90 Bq/kg d.w., and Empetrum nigrum, 15 - 60 Bq/kg d.w. Concentrations of more than 10 Bq/kg d.w. were also detected in leaves of birch (Betula pendula), in berries of Empetrum nigrum and in ferns (Dryopteris carthusiana, Dryopteris expansa, Polypodium vulgare). The Sr-90 concentrations in mushrooms were less than 10 Bq/kg d.w. and varied considerably from one species to another. The concentrations of Pu-239,240 were below the detection limits in mushrooms and berries. Detectable amounts of Pu-239,240 were found in ferns. Am-241 was detected in ferns, but also in a Cantharellus tubaeformis sample and in Calluna vulgaris, in which the Pu-239,240 concentrations were below the detection limits. The highest concentrations of Sr-90 in fresh water environment were detected in shells and flesh of freshwater clam, Anodonta sp., and in marine environment in Saduria entomon and Macoma balthica. In Anodonta sp. (both shells and flesh), also Pu-239,240 and Am-241 were detected. Pu-239,240 was detectable in almost all the marine samples. Concentration factors (CF) of Pu-239,240 were roughly at the same level or greater than those of Sr-90, especially in the marine environment. Best indicator organism for Sr in the fresh water environment was Anodonta sp., and then Nuphar lutea (CFs 103 - 104); and Macoma balthica and Fucus vesiculosus in the marine environment. Roots of Nymphaea candida and flesh of Anodonta sp. accumulated best Pu-239,240 in fresh water environment; The CFs of Pu-239,240 were greater in the marine environment compared to those in fresh water environment. Phytoplankton and periphyton accumulate most efficiently Pu-239,240 in the marine environment. The behavior of plutonium and americium were

  19. On the origin of class B floral homeotic genes: functional substitution and dominant inhibition in Arabidopsis by expression of an orthologue from the gymnosperm Gnetum.

    Science.gov (United States)

    Winter, Kai-Uwe; Saedler, Heinz; Theissen, Günter

    2002-08-01

    Class B floral homeotic genes are involved in specifying stamen and petal identity in angiosperms (flowering plants). Here we report that gymnosperms, the closest relatives of the angiosperms, contain at least two different clades representing putative orthologues of class B genes, termed GGM2-like and DAL12-like genes. To obtain information about the functional conservation of the class B genes in seed plants, the representative of one of these clades from Gnetum, termed GGM2, was expressed under the control of the CaMV 35S promoter in Arabidopsis wild-type plants and in different class B mutants. In wild-type plants and in a conditional mutant grown at a permissive temperature, gain-of-function phenotypes were obtained in whorls 1 and 4, where class B genes are usually not expressed. In contrast, loss-of-function phenotypes were observed in whorls 2 and 3, where class B genes are expressed. In different class B gene null mutants of Arabidopsis, and in the conditional B mutant grown at the non-permissive temperature, a partial complementation of the mutant phenotype was obtained. In situ hybridization studies and class B gene promoter test fusion experiments demonstrated that the gain-of-function phenotypes are not due to an upregulation of the endogenous B genes from Arabidopsis, and hence probably involve interactions between GGM2 protein homodimers and class B protein target genes other than the Arabidopsis class B genes itself. To our knowledge, this is the first time that partial complementation of a homeotic mutant by an orthologous gene from a distantly related species has been reported. These data suggest that GGM2 has a function in the gymnosperm Gnetum which is related to that of class B floral organ identity genes of angiosperms. That function may be in the specification of male reproductive organ identity, and in distinguishing male from female reproductive organs. PMID:12182704

  20. TIR-NBS-LRR genes are rare in monocots: evidence from diverse monocot orders

    Directory of Open Access Journals (Sweden)

    Tarr D Ellen K

    2009-09-01

    Full Text Available Abstract Background Plant resistance (R gene products recognize pathogen effector molecules. Many R genes code for proteins containing nucleotide binding site (NBS and C-terminal leucine-rich repeat (LRR domains. NBS-LRR proteins can be divided into two groups, TIR-NBS-LRR and non-TIR-NBS-LRR, based on the structure of the N-terminal domain. Although both classes are clearly present in gymnosperms and eudicots, only non-TIR sequences have been found consistently in monocots. Since most studies in monocots have been limited to agriculturally important grasses, it is difficult to draw conclusions. The purpose of our study was to look for evidence of these sequences in additional monocot orders. Findings Using degenerate PCR, we amplified NBS sequences from four monocot species (C. blanda, D. marginata, S. trifasciata, and Spathiphyllum sp., a gymnosperm (C. revoluta and a eudicot (C. canephora. We successfully amplified TIR-NBS-LRR sequences from dicot and gymnosperm DNA, but not from monocot DNA. Using databases, we obtained NBS sequences from additional monocots, magnoliids and basal angiosperms. TIR-type sequences were not present in monocot or magnoliid sequences, but were present in the basal angiosperms. Phylogenetic analysis supported a single TIR clade and multiple non-TIR clades. Conclusion We were unable to find monocot TIR-NBS-LRR sequences by PCR amplification or database searches. In contrast to previous studies, our results represent five monocot orders (Poales, Zingiberales, Arecales, Asparagales, and Alismatales. Our results establish the presence of TIR-NBS-LRR sequences in basal angiosperms and suggest that although these sequences were present in early land plants, they have been reduced significantly in monocots and magnoliids.

  1. Conifer R2R3-MYB transcription factors: sequence analyses and gene expression in wood-forming tissues of white spruce (Picea glauca

    Directory of Open Access Journals (Sweden)

    Grima-Pettenati Jacqueline

    2007-03-01

    Full Text Available Abstract Background Several members of the R2R3-MYB family of transcription factors act as regulators of lignin and phenylpropanoid metabolism during wood formation in angiosperm and gymnosperm plants. The angiosperm Arabidopsis has over one hundred R2R3-MYBs genes; however, only a few members of this family have been discovered in gymnosperms. Results We isolated and characterised full-length cDNAs encoding R2R3-MYB genes from the gymnosperms white spruce, Picea glauca (13 sequences, and loblolly pine, Pinus taeda L. (five sequences. Sequence similarities and phylogenetic analyses placed the spruce and pine sequences in diverse subgroups of the large R2R3-MYB family, although several of the sequences clustered closely together. We searched the highly variable C-terminal region of diverse plant MYBs for conserved amino acid sequences and identified 20 motifs in the spruce MYBs, nine of which have not previously been reported and three of which are specific to conifers. The number and length of the introns in spruce MYB genes varied significantly, but their positions were well conserved relative to angiosperm MYB genes. Quantitative RTPCR of MYB genes transcript abundance in root and stem tissues revealed diverse expression patterns; three MYB genes were preferentially expressed in secondary xylem, whereas others were preferentially expressed in phloem or were ubiquitous. The MYB genes expressed in xylem, and three others, were up-regulated in the compression wood of leaning trees within 76 hours of induction. Conclusion Our survey of 18 conifer R2R3-MYB genes clearly showed a gene family structure similar to that of Arabidopsis. Three of the sequences are likely to play a role in lignin metabolism and/or wood formation in gymnosperm trees, including a close homolog of the loblolly pine PtMYB4, shown to regulate lignin biosynthesis in transgenic tobacco.

  2. Conifer reproductive development involves B-type MADS-box genes with distinct and different activities in male organ primordia.

    Science.gov (United States)

    Sundström, Jens; Engström, Peter

    2002-07-01

    The Norway spruce MADS-box genes DAL11, DAL12 and DAL13 are phylogenetically related to the angiosperm B-function MADS-box genes: genes that act together with A-function genes in specifying petal identity and with C-function genes in specifying stamen identity to floral organs. In this report we present evidence to suggest that the B-gene function in the specification of identity of the pollen-bearing organs has been conserved between conifers and angiosperms. Expression of DAL11 or DAL12 in transgenic Arabidopsis causes phenotypic changes which partly resemble those caused by ectopic expression of the endogenous B-genes. In similar experiments, flowers of Arabidopsis plants expressing DAL13 showed a different homeotic change in that they formed ectopic anthers in whorls one, two or four. We also demonstrate the capacity of the spruce gene products to form homodimers, and that DAL11 and DAL13 may form heterodimers with each other and with the Arabidopsis B-protein AP3, but not with PI, the second B-gene product in Arabidopsis. In situ hybridization experiments show that the conifer B-like genes are expressed specifically in developing pollen cones, but differ in both temporal and spatial distribution patterns. These results suggest that the B-function in conifers is dual and is separated into a meristem identity and an organ identity function, the latter function possibly being independent of an interaction with the C-function. Thus, even though an ancestral B-function may have acted in combination with C to specify micro- and megasporangia, the B-function has evolved differently in conifers and angiosperms. PMID:12121446

  3. Spliceosomal introns in the 5′ untranslated region of plant BTL RING-H2 ubiquitin ligases are evolutionary conserved and required for gene expression

    Science.gov (United States)

    2013-01-01

    Background Introns located close to the 5′ end of a gene or in the 5′ untranslated region often exert positive effects on gene expression. This effect, known as intron-mediated enhancement (IME), has been observed in diverse eukaryotic organisms, including plants. The sequences involved in IME seem to be spread across the intron and function in an additive manner. The IMEter algorithm was developed to predict plant introns that may enhance gene expression. We have identified several plant members of the BTL class of E3s, which may have orthologs across eukaryotes, that contain a 5′UTR intron. The RING finger E3 ligases are key enzymes of the ubiquitination system that mediate the transfer of ubiquitin to substrates. Results In this study, we retrieved BTL sequences from several angiosperm species and found that 5′UTR introns showing a strong IMEter score were predicted, suggesting that they may be conserved by lineage. Promoter-GUS fusion lines were used to confirm the IME effect of these 5′UTR introns on gene expression. IMEter scores of BTLs were compared with the 5′UTR introns of two gene families MHX and polyubiquitin genes. Conclusions Analysis performed in two Arabidopsis BTL E3 ligases genes indicated that the 5′UTR introns were essential for gene expression in all the tissues tested. Comparison of the average 5′UTR intron size on three gene families in ten angiosperm species suggests that a prevalent size for a 5′UTR intron is in the range of 600 nucleotides, and that the overall IMEter score within a gene family is preserved across several angiosperms. Our results indicated that gene expression dependent on a 5′UTR intron is an efficient regulatory mechanism in BTL E3 ligases that has been preserved throughout plant evolution. PMID:24228887

  4. Bayesian phylogeny of sucrose transporters: Ancient origins, differential expansion and convergent evolution in monocots and dicots

    Directory of Open Access Journals (Sweden)

    Duo ePeng

    2014-11-01

    Full Text Available Sucrose transporters (SUTs are essential for the export and efficient movement of sucrose from source leaves to sink organs in plants. The angiosperm SUT family was previously classified into three or four distinct groups, Types I, II (subgroup IIB and III, with dicot-specific Type I and monocot-specific Type IIB functioning in phloem loading. To shed light on the underlying drivers of SUT evolution, Bayesian phylogenetic inference was undertaken using 41 sequenced plant genomes, including seven basal lineages at key evolutionary junctures. Our analysis supports four phylogenetically and structurally distinct SUT subfamilies, originating from two ancient groups (AG1 and AG2 that diverged early during terrestrial colonization. In both AG1 and AG2, multiple intron acquisition events in the progenitor vascular plant established the gene structures of modern SUTs. Tonoplastic Type III and plasmalemmal Type II represent evolutionarily conserved descendants of AG1 and AG2, respectively. Type I and Type IIB were previously thought to evolve after the dicot-monocot split. We show, however, that divergence of Type I from Type III SUT predated basal angiosperms, likely associated with evolution of vascular cambium and phloem transport. Type I SUT was subsequently lost in monocots along with vascular cambium, and independent evolution of Type IIB coincided with modified monocot vasculature. Both Type I and Type IIB underwent lineage-specific expansion. In multiple unrelated taxa, the newly-derived SUTs exhibit biased expression in reproductive tissues, suggesting a functional link between phloem loading and reproductive fitness. Convergent evolution of Type I and Type IIB for SUT function in phloem loading and reproductive organs supports the idea that differential vascular development in dicots and monocots is a strong driver for SUT family evolution in angiosperms.

  5. Origin and differentiation of endemism in the flora of China

    Institute of Scientific and Technical Information of China (English)

    WU Zhengyi; SUN Hang; ZHOU Zhekun; PENG Hua; LI Dezhu

    2007-01-01

    The present paper analyzed 239 endemic genera in 67 families in the flora of seed plants in China.The results showed that there are five families containing more than ten endemic genera,namely,Gesneriaceae (27),which hereafter refers to the number of endemic genera in China,Composite (20),Labiatae (12),Cruciferae (11),and Umbelliferae (10),15 families with two endemic genera,and another 30 families with only one endemic genus.Four monotypic families (Ginkgoaceae,Davidiaceae,Eucommiaceae and Acanthochlamydaceae)are the most ancient,relict and characteristic in the flora of seed plants in China.Based on integrative data of systematics,fossil history,and morphological and molecular evidence of these genera,their origin,evolution and relationships were discussed.In gymnosperms,all endemic genera are relicts of the Arctic-Tertiary flora,having earlier evolutionary history,and can be traced back to the Cretaceous or to the Jurassic and even earlier.In angiosperms,the endemic genera are mostly relicts,and are represented in all lineages in the"Eight-Class System ofClassification of Angiosperms",and endemism can be found in almost every evolutionary stage of extant angiosperms.The relict genera once occupied huge areas in the northern hemisphere in the Tertiary or the late Cretaceous,while neo-endemism mostly originated in the late Tertiary.They came from Arctic-Tertiary,Paleo-tropical-Tertiary and Tethys-Tertiary florisitic elements,and the blend of the three elements with many genera of autochthonous origin.The endemism was formed when some dispersal routes such as the North Atlantic Land Bridge,and the Bering Bridge became discontinuous during the Tertiary,as well as the climate change and glaciations in the late Tertiary and the Quaternary.Therefore,the late Tertiary is the starting point of extant endemism of the flora in China.

  6. A review of methods for the production of haploids in seed plants

    International Nuclear Information System (INIS)

    This paper is a review of the methods which have been tried to produce haploids in seed plants. Because of their unique genetic constitution the haploids provide useful material for the study of various fundamental cytological and genetic problems. Thus the diploidization of haploids in conifers and subsequent intercrossing might allow the use of the same breeding technique as those which have been used with great success in maize breeding. Induced parthenogenesis in angiosperms has led to the formation of haploids in at least 25 genera but the number of plants obtained is generally too low for a practical utilization. The most promising method in angiosperms is in vitro cultivation of anthers which has hitherto yielded haploids in relatively large numbers in at least l5 genera but certainly can be applied with success in many more. Isolation of protoplasts or whole cells of diploid and haploid tissues and regeneration of entire plants from these protoplasts or cells have been accomplished in a few angiosperm genera. In gymnosperms all attempts to produce complete haploid plants have up to now failed. In this group there is possibly a relationship between polyembryonic seeds and the presence of small, haploid embryos. Therefore, the in vitro cultivation of small embryos of such seeds may result in the formation of independent haploid plants. In vitro cultivation of whole microsporangia or pollen has led to the production of calli in a few gymnosperm genera and in one case roots have even been induced. In some gymnosperms female gametophytes cultured on nutrient medium have yielded calli and in a few genera even root-like organs or small seedlings have arisen. (author)

  7. A spruce gene map infers ancient plant genome reshuffling and subsequent slow evolution in the gymnosperm lineage leading to extant conifers

    Directory of Open Access Journals (Sweden)

    Pavy Nathalie

    2012-10-01

    Full Text Available Abstract Background Seed plants are composed of angiosperms and gymnosperms, which diverged from each other around 300 million years ago. While much light has been shed on the mechanisms and rate of genome evolution in flowering plants, such knowledge remains conspicuously meagre for the gymnosperms. Conifers are key representatives of gymnosperms and the sheer size of their genomes represents a significant challenge for characterization, sequencing and assembling. Results To gain insight into the macro-organisation and long-term evolution of the conifer genome, we developed a genetic map involving 1,801 spruce genes. We designed a statistical approach based on kernel density estimation to analyse gene density and identified seven gene-rich isochors. Groups of co-localizing genes were also found that were transcriptionally co-regulated, indicative of functional clusters. Phylogenetic analyses of 157 gene families for which at least two duplicates were mapped on the spruce genome indicated that ancient gene duplicates shared by angiosperms and gymnosperms outnumbered conifer-specific duplicates by a ratio of eight to one. Ancient duplicates were much more translocated within and among spruce chromosomes than conifer-specific duplicates, which were mostly organised in tandem arrays. Both high synteny and collinearity were also observed between the genomes of spruce and pine, two conifers that diverged more than 100 million years ago. Conclusions Taken together, these results indicate that much genomic evolution has occurred in the seed plant lineage before the split between gymnosperms and angiosperms, and that the pace of evolution of the genome macro-structure has been much slower in the gymnosperm lineage leading to extent conifers than that seen for the same period of time in flowering plants. This trend is largely congruent with the contrasted rates of diversification and morphological evolution observed between these two groups of seed

  8. Molecular phylogeny and radiation time of erysiphales inferred from the nuclear ribosomal DNA sequences

    International Nuclear Information System (INIS)

    Phylogenetic relationships of Erysiphales within Ascomycota were inferred from the newly determined sequences of the 18S rDNA and partial sequences of the 28S rDNA including the D1 and D2 regions of 10 Erysiphales taxa. Phylogenetic analyses revealed that the Erysiphales form a distinct clade among ascomycetous fungi suggesting that the Erysiphales diverged from a single ancestral taxon. The Myxotrichaceae of the Onygenales was distantly related to the other onygenalean families and was the sister group to the Erysiphales calde, with which it combined to form a clade. The Erysiphales/Myxotrichaceae clade was also closely related to some discomycetous fungi (Leotiales, Cyttariales and Thelebolaceae) including taxa that form cleistothecial ascomata. The present molecular analyses as well as previously reported morphological observations suggest the possible existence of a novel evolutionary pathway from cleistothecial discomycetous fungi to Erysiphales and Myxotrichaceae. However, since most of these fungi, except for the Erysiphales, are saprophytic on dung and/or plant materials, the questions of how and why an obligate biotroph like the Erysiphales radiated from the saprophytic fungi remain to be addressed. We also estimated the radiation time of the Erysiphales using the 18S rDNA sequences and the two molecular clockes that have been previously reported. The calculation showed that the Erysiphales split from the Myxotrichaceae 190–127 myr ago. Since the radiation time of the Erysiphales does not exceed 230 myr ago, even when allowance is made for the uncertainty of the molecular clocks, it is possible to consider that the Erysiphales evolved after the radiation of angiosperms. The results of our calculation also showed that the first radiation within the Erysiphales (138–92 myr ago) coincided with the date of a major diversification of angiosperms (130–90 myr ago). These results may support our early assumption that the radiation of the Erysiphales

  9. A new Cretaceous terrestrial ecosystem from Gondwana with the description of a new sauropod dinosaur

    OpenAIRE

    Jorge O. Calvo; Juan D. Porfiri; Bernardo J. González-Riga; ALEXANDER W. A. KELLNER

    2007-01-01

    A unique site at the northern area of Patagonia (Neuquén, Argentina) reveals a terrestrial ecosystem preserved in a detail never reported before in a Late Cretaceous deposit. An extraordinary diversity and abundance of fossils was found concentrated in a 0.5 m horizon in the same quarry, including a new titanosaur sauropod, Futalognkosaurus dukei n.gen., n.sp, which is the most complete giant dinosaur known so far. Several plant leaves, showing a predominance of angiosperms over gymnosperms t...

  10. Identifizierung von direkten Zielgenen des homöotischen Transkriptionsfaktors DEFICIENS aus Antirrhinum majus mittels Chromatin Immunopräzipitation

    OpenAIRE

    Müller, Bettina M.

    2003-01-01

    Die Blüten angiospermer Pflanzen bestehen aus morphologisch distinkten Organen, die in vier Wirteln angeordnet sind. Im ersten Wirtel werden Sepalen, im zweiten Petalen, im dritten Stamina und im vierten Karpelle angelegt. In Antirrhinum üben die MADS-Box Transkriptionsfaktoren DEFICIENS (DEF) und GLOBOSA (GLO) Schlüsselfunktionen bei der Ausprägung der Petalen und Stamina aus. Der Funktionsverlust von DEF oder GLO resultiert in einer homöotischen Umformung von Petalen zu Sepalen und von Stam...

  11. The Mitochondrion-Located Protein OsB12D1 Enhances Flooding Tolerance during Seed Germination and Early Seedling Growth in Rice

    OpenAIRE

    Dongli He; Hui Zhang; Pingfang Yang

    2014-01-01

    B12D belongs to a function unknown subgroup of the Balem (Barley aleurone and embryo) proteins. In our previous work on rice seed germination, we identified a B12D-like protein encoded by LOC_Os7g41350 (named OsB12D1). OsB12D1 pertains to an ancient protein family with an amino acid sequence highly conserved from moss to angiosperms. Among the six OsB12Ds, OsB12D1 is one of the major transcripts and is primarily expressed in germinating seed and root. Bioinformatics analyses indicated that O...

  12. ABC model and floral evolution

    Institute of Scientific and Technical Information of China (English)

    LI Guisheng; MENG Zheng; KONG Hongzhi; CHEN Zhiduan; LU Anming

    2003-01-01

    The paper introduces the classical ABC model of floral development and thereafter ABCD, ABCDE and quartet models, and presents achievements in the studies on floral evolution such as the improved understanding on the relationship of reproductive organs between gnetophytes and angiosperms, new results in perianth evolution and identified homology of floral organs between dicots and monocots. The evo-devo studies on plant taxa at different evolutionary levels are useful to better understanding the homology of floral organs, and to clarifying the mysteries of the origin and subsequent diversification of flowers.

  13. Analysis of the hybrid proline-rich protein families from seven plant species suggests rapid diversification of their sequences and expression patterns

    Directory of Open Access Journals (Sweden)

    Fischer Lukáš

    2007-11-01

    Full Text Available Abstract Background Plant hybrid proline-rich proteins (HyPRPs are putative cell wall proteins consisting, usually, of a repetitive proline-rich (PR N-terminal domain and a conserved eight-cysteine motif (8 CM C-terminal domain. Understanding the evolutionary dynamics of HyPRPs might provide not only insight into their so far elusive function, but also a model for other large protein families in plants. Results We have performed a phylogenetic analysis of HyPRPs from seven plant species, including representatives of gymnosperms and both monocot and dicot angiosperms. Every species studied possesses a large family of 14–52 HyPRPs. Angiosperm HyPRPs exhibit signs of recent major diversification involving, at least in Arabidopsis and rice, several independent tandem gene multiplications. A distinct subfamily of relatively well-conserved C-type HyPRPs, often with long hydrophobic PR domains, has been identified. In most of gymnosperm (pine HyPRPs, diversity appears within the C-type group while angiosperms have only a few of well-conserved C-type representatives. Atypical (glycine-rich or extremely short N-terminal domains apparently evolved independently in multiple lineages of the HyPRP family, possibly via inversion or loss of sequences encoding proline-rich domains. Expression profiles of potato and Arabidopsis HyPRP genes exhibit instances of both overlapping and complementary organ distribution. The diversified non-C-type HyPRP genes from recently amplified chromosomal clusters in Arabidopsis often share their specialized expression profiles. C-type genes have broader expression patterns in both species (potato and Arabidopsis, although orthologous genes exhibit some differences. Conclusion HyPRPs represent a dynamically evolving protein family apparently unique to seed plants. We suggest that ancestral HyPRPs with long proline-rich domains produced the current diversity through ongoing gene duplications accompanied by shortening

  14. First report of three redlisted tree species from swampy relics of Goa State, India

    Directory of Open Access Journals (Sweden)

    A. Prabhugaonkar

    2014-02-01

    Full Text Available Myristica swamps, one of the relic ecosystems of Western Ghats, are considered home for many rare and endemic angiosperms. During an inventory of Myristica swamps in Goa State, two critically endangered species and one endangered species, viz. Semecarpus kathalekanensis Dasappa and M.H.Swaminath, Syzygium travancoricum Gamble and Myristica fatua Houtt. var. magnifica (Bedd. J. Sinclair respectively were recorded. Present report forms first record of these three tree species from the Goa State. This report extends their distribution into Northern Western Ghats from central Western Ghats.

  15. Ferns and flowering plants of Klaserie Private Nature Reserve, eastern Transvaal: an annotated checklist

    Directory of Open Access Journals (Sweden)

    N. Zambatis

    1994-12-01

    Full Text Available An annotated checklist of the plant taxa of the Klaserie Private Nature Reserve, eastern Transvaal Lowveld, is presented. Of the 618 infrageneric taxa recorded, six are pteridophytes and the remainder angiosperms. Of these, 161 are monocotyledons and 451 dicotyledons. Five of the latter are currently listed in the Red Data List of the Transvaal, two of which are first records for the Transvaal Lowveld. The vegetation of the reserve shows strong affinities with the Savanna Biome, and to a lesser degree, with the Grassland Biome.

  16. Flavonoids can protect maize DNA from the induction of ultraviolet radiation damage

    International Nuclear Information System (INIS)

    Diverse flavonoid compounds are widely distributed in angiosperm families. Flavonoids absorb radiation in the ultraviolet (UV) region of the spectrum, and it has been proposed that these compounds function as UV filters. We demonstrate that the DNA in Zea mays plants that contain flavonoids (primarily anthocyanins) is protected from the induction of damage caused by UV radiation relative to the DNA in plants that are genetically deficient in these compounds. DNA damage was measured with a sensitive and simple assay using individual monoclonal antibodies, one specific for cyclobutane pyrimidine dimer damage and the other specific for pyrimidine(6,4)pyrimidone damage. (author)

  17. New colporate pollen taxa from Neyveli lignite, South India

    Energy Technology Data Exchange (ETDEWEB)

    Singh, A.; Misra, B.K. (Birbal Sahni Institute of Palaeobotany, Lucknow (India))

    1991-02-19

    Four new pollen genera: {ital Bacuspinulopollenites} {ital Cuddaloripollis}, {ital Scrobiculatricolporites}, {ital Tamilipollenites} and seven new species from the subsurface lignite samples of the Mine III area of the Neyveli Lignite Field are described. {ital Tricolporopilites} (Kar and Saxena) Kar 1985 is amended and three new species {ital T. uniformis}, {ital T. differentialis} and {ital T. tectatus} are assigned to it. These colporate angiospermous pollen taxa provide additional information on the palynofloral composition of the main lignite seam encountered in three boreholes. 19 refs., 5 figs.

  18. Geologic and biostratigraphic framework of the non-marine Cretaceous-Tertiary boundary interval in western North America

    Science.gov (United States)

    Nichols, D.J.

    1990-01-01

    Palynologically defined Cretaceous-Tertiary boundary sites in nonmarine rocks in western North America exhibit similar characteristics. All are marked by abrupt disappearance of the regional uppermost Cretaceous palynoflora at the level of an iridium anomaly; most also yeild shock-metamorphosed minerals. All are in coal-bearing, fluvial or paludal depositional settings, although the boundary horizon may be below, within, above, or at some stratigraphic distance from coal seams. At many sites the lowermost Tertiary beds contain assemblages overwhelmed by fern spores that, together with extinctions of some groups of angiosperms, are taken as evidence of regional devastation of terrestrial plant communities and subsequent recolonization by pioneer species. ?? 1990.

  19. WOX2 and polar auxin transport during spruce embryo pattern formation

    OpenAIRE

    Palovaara, Joakim; Hakman, Inger

    2009-01-01

    The WOX family of transcription factors and polar auxin transport (PAT) are both essential for embryonic patterning and thus normal embryo development in angiosperms. Recent analysis by us of WOX-related genes in Picea and Pinus suggests that they play fundamental roles during embryo development also in conifers.1 It has been proposed that there is a connection between the spatial separation of WOX2 and WOX8, and PAT in the formation of the apical-basal axis in Arabidopsis embryos and that bo...

  20. The WUSCHEL-RELATED HOMEOBOX 3 gene PaWOX3 regulates lateral organ formation in Norway spruce

    OpenAIRE

    Alvarez, Jose M.; Sohlberg, Joel; Engström, Peter; Zhu, Tianqing; Englund, Marie; Moschou, Panagiotis N.; Von Arnold, Sara

    2015-01-01

    In angiosperms, WUSCHEL-RELATED HOMEOBOX 3 (WOX3) genes are required for the recruitment of founder cells from the lateral domains of shoot meristems that form lateral regions of leaves. However, the regulation of the formation of lateral organs in gymnosperms remains unknown. By using somatic embryos of Norway spruce ( Picea abies) we have studied the expression and function of PaWOX3 during embryo development. The mRNA abundance of PaWOX3 was determined by quantitative real-time PCR, and th...

  1. Cytological study of radiation induced alterations in cytoplasmic factors controlling male sterility in corn. Progress report, February 28, 1975--December 1, 1975

    International Nuclear Information System (INIS)

    Progress is reported on the following research projects: cytoplasmic constituents of the embryo of various gymnosperms and angiosperms; cytoplasmic male sterility in corn; modification of cytoplasmic sterility factors using gamma radiation, EMS, and ethidium bromide; selection for sterile, blight-resistant corn plants; electron microscopy study of abnormal mitochondria in cytoplasm of corn; cytoplasmic male sterility in Petunia; non-Mendelian variegation in Petunia and Nicotiana; graft transmission of cytoplasmic male sterility; cytoplasmic male sterility in Vicia faba; and studies on Blakeslee's I virus in Datura

  2. A checklist of the plants of the forests and grasslands in the Weza district, southern KwaZulu-Natal and a review of their status in the Red Data List

    Directory of Open Access Journals (Sweden)

    Graham R.H. Grieve

    2015-03-01

    Full Text Available Eastern mistbelt forests are naturally fragmented forests with grassland which occur from the Eastern Cape to KwaZulu-Natal, South Africa. These were heavily logged by colonial settlers and continue to be harvested despite being protected. Consequently we documented a checklist of the plants of the forests and grasslands in the Weza district (3029DA WEZA, southern KwaZulu-Natal, including Ngeli Forest and nearby indigenous forest patches to highlight their biodiversity status and need for conservation. We also reviewed their status in the Red Data List. Of the 1554 records included in this summary of plant species for the Weza district, there were 6 lichens (0.4%, 46 bryophytes (3.0%, 58 pteridophytes (3.7%, 6 gymnosperms (0.4% and the remaining 1424 species angiosperms (92.5%. Of the angiosperms, 27.3% were monocotyledons and 72.7% were dicotyledons. The most species-rich family was Asteraceae (239 species followed by Fabaceae (115 species, Liliaceae (used for purposes of comparison against older studies – 89 species, Orchidaceae (89 species, Iridaceae (59 species, Poaceae (58 species, Asclepidaceae (again used for purposes of comparison against older studies – 57 species, Scrophulariaceae (42 species, Euphorbiaceae (32 species, Lamiaceae (32 species and Rubiaceae (27 species. These 10 families each comprised more than 2% of the species in the list. Together they contributed 55% of the angiosperm species and 34.1% of the angiosperm genera. The biodiversity and conservation value of the study area are conserved pockets of eastern mistbelt forest, Drakensberg foothill moist grassland and mistbelt grassland. More than 4% of the species are under some degree of threat, as was evidenced by the number of species regarded as endangered (5, vulnerable (18, near threatened (10, critically rare (1, rare (20 or declining (11 amongst the 1554 species covered in the list.Conservation implications: In terms of taxa under some degree of threat, number of

  3. Collective biology of neoplastic disease in dicotyledonous plants

    International Nuclear Information System (INIS)

    We discuss the two different responses from the angiosperms to the specific molecular mechanisms of the tumor-inducing agent contained in the bacterium Agrobacterium tumefaciens. This is done in terms of the collective variables for expressing genetic response to a continuously varying supply of energy from metabolic pathways. We are led to the conjecture that the expression of the recessive oncogenes may not be restricted to humans (retinoblastoma and osteosarcoma), but may also occur in plants (crown gall), and be expressed through a heat-shock. (author). 11 refs

  4. Comparative analysis of microspore size variability in the genus Aesculus (Hippocastanaceae

    Directory of Open Access Journals (Sweden)

    Ćalić-Dragosavac Dušica

    2009-01-01

    Full Text Available Pollen size varies extensively among angiosperm species and partially reflects evolutionary adaptation of each species to the pollination and fertilization environment. Size of uninuclear microspores in Aesculus parviflora was analyzed and compared with the size of microspores in Aesculus hippocastanum, Aesculus carnea, and Aesculus flava. The microspores came from closed flower buds of different size (3, 4, and 5 mm isolated from lower (female flowers, middle (bisexual flowers, and upper (male flowers segments of inflorescences. Aesculus parviflora had smaller microspores than Aesculus carnea and Aesculus flava, but larger microspores than Aesculus hippocastanum. All analyzed microspores showed bimodal distribution in all investigated species of the genus Aesculus.

  5. Fossil history of Mesozoic weevils (Coleoptera:Curculionoidea)

    Institute of Scientific and Technical Information of China (English)

    Andrei A.Legalov

    2012-01-01

    The first synopsis of Mesozoic weevils (Curculionoidea: Coleoptera) is presented.Changes of family,genera and species abundance during the Mesozoic revealed three distributional patterns.The Jurassic (Karatau) fauna was dominated by the Nemonychidae.During the Early Cretaceous (beginning at the Jurassic/Cretaceous border),the Ithyceridae was the prevalent group with a significant role played by the Nemonychidae.In the Late Cretaceous (Cenomanian and Turonian),the major groups were the Curculionidae and Brentidae.Obviously,the change of weevil fauna during this period was due to the expansion of the angiosperms,which provided multiple niches in their vegetative and reproductive organs for weevil development.

  6. In vitro depolymerization of lignin by manganese peroxidase of Phanerochaete chrysosporium

    International Nuclear Information System (INIS)

    Homogeneous manganese peroxidase catalyzed the in vitro partial depolymerization of four different 14C-labeled synthetic lignin preparations. Gel permeation profiles demonstrated significant depolymerization of 14C-sidechain-labeled syringyl lignin, a 14C-sidechain-labeled syringyl-guaiacyl copolymer (angiosperm lignin), and depolymerization of 14C-sidechain- and 14C-ring-labeled guaiacyl lignins (gymnosperm lignin). 3,5-Dimethoxy-1,4-benzo-quinone, 3,5-dimethoxy-1,4-hydroquinone, and syringylaldehyde were identified as degradation products of the syringyl and syringyl-guaiacyl lignins. These results suggest that manganese peroxidase plays a significant role in the depolymerization of lignin by Phanerochaete chrysosporium

  7. Phylogenetic utility of the AP3/DEF K-domain and its molecular evolution in Impatiens (Balsaminaceae)

    OpenAIRE

    Janssens, S.; Geuten, K.; Viaene, T.; Yong-Ming, Y.; Yi, S; Smets, E.

    2007-01-01

    APETALA3 (AP3)/DEFICIENS (DEF) is a MADS-box transcription factor that is involved in establishing the identity of petal and stamen floral organs. The AP3/DEF gene lineage has been extensively examined throughout the angiosperms in order to better understand its role in floral diversity and evolution. As a result, a large number of cloned AP3/DEF orthologues are available, which can be used for the design of taxon specific primers for phylogeny reconstruction of close relatives of the group o...

  8. Universality of phloem transport in seed plants

    DEFF Research Database (Denmark)

    Jensen, Kåre Hartvig; Liesche, Johannes; Bohr, Tomas;

    2012-01-01

    scaling predictions. The compiled data allowed calculating stem sieve element conductivity and predicting phloem sap flow velocity. The central finding of this work is that all vascular plants seem to have evolved efficient osmotic pumping units, despite their huge disparity in size and morphology. This......Since Münch in the 1920s proposed that sugar transport in the phloem vascular system is driven by osmotic pressure gradients, his hypothesis has been strongly supported by evidence from herbaceous angiosperms. Experimental constraints made it difficult to test this proposal in large trees, where...

  9. Breeding biology and distyly in Palicourea rigida H. B. & K. (Rubiaceae) in the Cerrados of Central Brazil Biologia reprodutiva e distilia em Palicourea rigida H. B. & K. (Rubiaceae) em Cerrados do Brasil Central

    OpenAIRE

    Adriana de Oliveira Machado; Ana Palmira Silva; Helder Consolaro; Mariluza A. Granja e Barros; Paulo Eugênio Oliveira

    2010-01-01

    Distyly is a floral polymorphism more common among the Rubiaceae than in any other angiosperm group. Palicourea rigida is a typically distylous species of the Rubiaceae widely distributed in the Brazilian Cerrados. This work aimed to study the floral biology and breeding system of P. rigida in order to verify if there wasasymmetry between floral morphs. The work was carried out at Fazenda Água Limpa, Brasília-DF, from 1993 to 1995; and at Serra Caldas Novas State Park-Goias and in Clube Caça ...

  10. Subspecialization of R2R3-MYB Repressors for Anthocyanin and Proanthocyanidin Regulation in Forage Legumes

    OpenAIRE

    Albert, Nick W.

    2015-01-01

    The synthesis of anthocyanin pigments and proanthocyanidins (condensed tannins) is regulated by MYB-bHLH-WDR (MBW) transcription factor complexes in all angiosperms studied to date. Tr-MYB133 and Tr-MYB134 were isolated from Trifolium repens and encode R2R3-MYBs that antagonize the activity of MBW activation complexes. These two genes are conserved in other legume species, and form two sub-clades within the larger anthocyanin/proanthocyanidin clade of MYB repressors. However, unlike petunia a...

  11. Reinvestigation of the Miocene palynoflora from the Daotaiqiao Formation of north-eastern China using SEM

    Science.gov (United States)

    Akyurt, Elvan; Grímsson, Friðgeir; Zetter, Reinhard; Leng, Qin; Bouchal, Johannes Martin

    2016-04-01

    Here we report the first results of an ongoing study on the Miocene palynoflora from the Daotaiqiao Formation of north-eastern China. Using the single grain technique, we examined individual pollen and spores using both light and scanning electron microscopy. A previous study by Grímsson et al. (2012) on Onagraceae pollen grains from this locality, using the same technique identified five different species. Such a variety of Onagraceae from a single palynoflora is unknown elsewhere. The ongoing study suggests a remarkably rich pollen and spore flora with at least 15 different types of spores, one Ginkgo and one Ephedra type pollen, 11 conifer pollen types and approximately 145 angiosperm pollen types. Spores are very rare in the samples (≤1%). Conifer pollen grains are regularly observed but are not a dominant component (ca. 16 %). The samples yield a high quantity and diversity of angiosperm pollen (ca. 80%). The conifers include representatives of Cupressaceae (2 spp.), Pinaceae (Larix, Picea, Pinus, Tsuga) and Sciadopityaceae. The angiosperm pollen cover at least 40 families. Prominent elements are pollen of the Betulaceae (Alnus, Betula, Carpinus, Corylus), Cercidiphyllaceae (Cercidiphyllum), Ericaceae (8 spp.), Eucommiaceae (Eucommia), Fagaceae (Fagus, Quercus spp., Castaneoideae), Juglandaceae (Carya, Cyclocarya, Juglans, Pterocarya), Rosaceae (11 spp.), Sapindaceae (Acer, Aesculus) and Ulmaceae (Hemiptelia, Ulmus, Zelkova). The high angiosperm pollen diversity indicates a varying landscape with a relatively high variety of niches including riparian, dry and mesic forests. Most of the potential modern analogues of the fossil taxa are currently thriving under humid temperate (Cfa- and Cwa)-climates, pointing to paleoclimate conditions not unlike those found today in the lowlands and adjacent mountain regions of the (south-) eastern United States, the humid-meridional region of western Eurasia, and central and southern China, and Honshu (Japan). References

  12. Efficacy of generic allometric equations for estimating biomass: a test in Japanese natural forests.

    Science.gov (United States)

    Ishihara, Masae I; Utsugi, Hajime; Tanouchi, Hiroyuki; Aiba, Masahiro; Kurokawa, Hiroko; Onoda, Yusuke; Nagano, Masahiro; Umehara, Toru; Ando, Makoto; Miyata, Rie; Hiura, Tsutom

    2015-07-01

    Accurate estimation of tree and forest biomass is key to evaluating forest ecosystem functions and the global carbon cycle. Allometric equations that estimate tree biomass from a set of predictors, such as stem diameter and tree height, are commonly used. Most allometric equations are site specific, usually developed from a small number of trees harvested in a small area, and are either species specific or ignore interspecific differences in allometry. Due to lack of site-specific allometries, local equations are often applied to sites for which they were not originally developed (foreign sites), sometimes leading to large errors in biomass estimates. In this study, we developed generic allometric equations for aboveground biomass and component (stem, branch, leaf, and root) biomass using large, compiled data sets of 1203 harvested trees belonging to 102 species (60 deciduous angiosperm, 32 evergreen angiosperm, and 10 evergreen gymnosperm species) from 70 boreal, temperate, and subtropical natural forests in Japan. The best generic equations provided better biomass estimates than did local equations that were applied to foreign sites. The best generic equations included explanatory variables that represent interspecific differences in allometry in addition to stem diameter, reducing error by 4-12% compared to the generic equations that did not include the interspecific difference. Different explanatory variables were selected for different components. For aboveground and stem biomass, the best generic equations had species-specific wood specific gravity as an explanatory variable. For branch, leaf, and root biomass, the best equations had functional types (deciduous angiosperm, evergreen angiosperm, and evergreen gymnosperm) instead of functional traits (wood specific gravity or leaf mass per area), suggesting importance of other traits in addition to these traits, such as canopy and root architecture. Inclusion of tree height in addition to stem diameter improved

  13. PLANTS IN AID OF FAMILY PLANNING PROGRAMME

    OpenAIRE

    Oommachan, Mathew; Khan, Shaukat Saeed

    1981-01-01

    A preliminary survey was conducted during the years 1978-’79 at Bhopal and its neighbourhood to find out the medicinal plants and their utility. From among a total number of 850 angiospermic plant species of this region, about 10% of them were found having poisonous principles. One fourth of these poisonous plants can be used for safe termination of pregnancy. Certain of these plants are used by the villagers for criminal abortions and even for suicidal purpose. A good number of them can be u...

  14. Genetic variation detected by use of the M13 "DNA fingerprint" probe in Malus, Prunus, and Rubus (Rosaceae).

    Science.gov (United States)

    Nybom, H; Rogstad, S H; Schaal, B A

    1990-02-01

    Recently, "DNA fingerprints" have been reported in a wide array of organisms. We used the M13 repeat probe on several genera and species in the angiosperm family Rosaceae. Four apple cultivars could be differentiated when any one of five restriction enzymes was used to analyze minisatellite DNA. Similarly, four individual trees of Prunus serotina (black cherry) exhibited different "fingerprints" with each of four enyzmes. A total of 14 Rubus (blackberries and raspberries) plants representing four species were investigated with two enzymes. Extensive inter-and intraspecific variation was found. However, some closely growing plants had identical "fingerprints", probably due to their being derived through vegetative propagation. PMID:24226211

  15. Large-Scale Evolutionary Patterns of Host Plant Associations in the Lepidoptera

    DEFF Research Database (Denmark)

    Menken, S.B.J.; Boomsma, J.J.; van Nieukerken, E.J.

    2010-01-01

    categorizations for Britain are accurate predictors for the global fauna. The first (lower glossatan) radiation of the Lepidoptera started with monophagous, internal feeding on woody Eurosids I. Polyphagy on nonwoody Eurosids I evolved together with the ability to feed externally, but did initially not produce...... significant radiations. Exposed feeding became associated with radiations in the lower Ditrysia and Apoditrysia and remained correlated with more polyphagy, fewer woody host plants, and increasing use of other Angiosperm superorders. The macrolepidopteran radiation has frequent reversals to monophagy on woody...

  16. Accelerated Gene Evolution and Subfunctionalization in thePseudotetraploid Frog Xenopus Laevis

    Energy Technology Data Exchange (ETDEWEB)

    Hellsten, Uffe; Khokha, Mustafa K.; Grammar, Timothy C.; Harland,Richard M.; Richardson, Paul; Rokhsar, Daniel S.

    2007-03-01

    Ancient whole genome duplications have been implicated in the vertebrate and teleost radiations, and in the emergence of diverse angiosperm lineages, but the evolutionary response to such a perturbation is still poorly understood. The African clawed frog Xenopus laevis experienced a relatively recent tetraploidization {approx} 40 million years ago. Analysis of the considerable amount of EST sequence available for this species together with the genome sequence of the related diploid Xenopus tropicalis provides a unique opportunity to study the genomic response to whole genome duplication.

  17. Influences of floral composition and environment on plant biomarkers across a Cretaceous landscape (Big Cedar Ridge)

    Science.gov (United States)

    Bush, R. T.; Diefendorf, A. F.; Wing, S. L.; McInerney, F. A.

    2013-12-01

    The Late Cretaceous fossil site at Big Cedar Ridge (BCR; late Campanian, 72.7 Ma), located in the Bighorn Basin, Wyoming, USA, contains a flora preserved in situ in a volcanic ash tuff over an organic-rich paleosol. The BCR flora is irregularly but extensively exposed along a ~4 km north-south transect and records a lowland flora that grew on a coastal delta on the western shore of the Cretaceous Interior Seaway (Meeteetse Formation). The transect spans a diverse landscape and a range of environmental gradients from very carbon-rich, swampy soils in the southern portion to less carbon-rich in the north; the landscape is also intersected by multiple inactive channel cuts that were filling with sediment and organic matter at the time of ash deposition. Recently Wing and others (2012, Ecological Monographs) described the composition of the local plant community at high resolution across the entire landscape, including identification and quantification of cover and richness for >122 taxonomic morphotypes, for each of 100 sites along the transect. Big Cedar Ridge captures an important time in the ecological development of plant communities: the site preserves ferns, gymnosperms, and angiosperms in 'fern thicket' floral assemblages, which are rare today, as well as disturbed habitats with abundant herbaceous 'dicot' angiosperms. During the Late Cretaceous angiosperms were globally increasing in abundance, displacing other plant groups as vegetational dominants. This setting allows for a novel analysis of plant biomarkers in the context of floral diversity, abundance, and landscape heterogeneity. We quantified leaf waxes (n-alkyl lipids), plant-derived terpenoids, bacterial hopanes, carbon isotope values (including bulk and compound-specific), and percent total organic carbon of the underlying paleosol for 36 sites along the transect in order to assess the influence of floral composition and soil environment on biomarker distributions and preservation. We compare lipid

  18. Mitochondrial genome sequencing helps show the evolutionary mechanism of mitochondrial genome formation in Brassica

    Directory of Open Access Journals (Sweden)

    Yan Jiyong

    2011-10-01

    Full Text Available Abstract Background Angiosperm mitochondrial genomes are more complex than those of other organisms. Analyses of the mitochondrial genome sequences of at least 11 angiosperm species have showed several common properties; these cannot easily explain, however, how the diverse mitotypes evolved within each genus or species. We analyzed the evolutionary relationships of Brassica mitotypes by sequencing. Results We sequenced the mitotypes of cam (Brassica rapa, ole (B. oleracea, jun (B. juncea, and car (B. carinata and analyzed them together with two previously sequenced mitotypes of B. napus (pol and nap. The sizes of whole single circular genomes of cam, jun, ole, and car are 219,747 bp, 219,766 bp, 360,271 bp, and 232,241 bp, respectively. The mitochondrial genome of ole is largest as a resulting of the duplication of a 141.8 kb segment. The jun mitotype is the result of an inherited cam mitotype, and pol is also derived from the cam mitotype with evolutionary modifications. Genes with known functions are conserved in all mitotypes, but clear variation in open reading frames (ORFs with unknown functions among the six mitotypes was observed. Sequence relationship analysis showed that there has been genome compaction and inheritance in the course of Brassica mitotype evolution. Conclusions We have sequenced four Brassica mitotypes, compared six Brassica mitotypes and suggested a mechanism for mitochondrial genome formation in Brassica, including evolutionary events such as inheritance, duplication, rearrangement, genome compaction, and mutation.

  19. Saturated and aromatic diterpenoids and triterpenoids in Eocene coals and mudstones from China

    Energy Technology Data Exchange (ETDEWEB)

    Tuo, J.C.; Philp, R.P. [Chinese Academy of Science, Gansu (China)

    2005-02-01

    Several series of saturated, diaromatic, triaromatic C-ring cleaved and triaromatic diterpenoids and triterpernoids have been detected in 4 immature coal and mudstone samples. A number of these compounds appear to represent intermediates in a series of postulated pathways for progressive aromatization of biogenic diterpenoids and triterpenoids. Diagenetic pathways for the formation of tricyclic aromatic hydrocarbons from abietane and pimarane type diterpenoid precursors and for the formation of diaromatic, triaromatic C-cleaved and triaromatic hydrocarbons from P-amyrin and other triterpenoid precursors are proposed. Saturated and aromatized abietanes, pimaranes and phyllocladanes, which are the most abundant compounds in all 4 samples, indicate a predominant higher plant input which can be related to the Coniferales group but not to individual plant families. beta-Amyrin and other triterpenoid-derived triaromatic and triaromatic C-ring cleaved hydrocarbons with triterpenoid structures are thought to be characteristic for angiosperms. The relative concentrations of the triaromatic and triaromatic C-ring cleaved hydrocarbons are higher in samples 9602 (mudstone) and 9603 (coal) than samples 9601 (coal) and 9604 (mudstone) indicating samples 9602 (mudstone) and 9603 (coal) contain relatively more angiosperm derived organic matter than samples 9601 (coal) and 9604 (mudstone). The distribution patterns and the relative concentrations of saturated and aromatic diterpenoids and triterpenoids thus are valuable markers for the determination of the relative contents of biological sources of organic material in geological samples.

  20. Saturated and aromatic diterpenoids and triterpenoids in Eocene coals and mudstones from China

    Energy Technology Data Exchange (ETDEWEB)

    Jincai Tuo [Chinese Academy of Sciences, Lanzhou (China). Inst. of Geology; Philp, R.P. [Oklahoma Univ., Norman, OK (United States). School of Geology and Geophysics

    2005-02-01

    Several series of saturated, diaromatic, triaromatic C-ring cleaved and triaromatic diterpenoids and triterpenoids have been detected in 4 immature coal and mudstone samples. A number of these compounds appear to represent intermediates in a series of postulated pathways for progressive aromatization of biogenic diterpenoids and triterpenoids. Diagenetic pathways for the formation of tricyclic aromatic hydrocarbons from abietane and pimarane type diterpenoid precursors and for the formation of diaromatic, triaromatic C-cleaved and triaromatic hydrocarbons from {beta}-amyrin and other triterpenoid precursors are proposed. Saturated and aromatized abietanes, pimaranes and phyllocladanes, which are the most abundant compounds in all 4 samples, indicate a predominant higher plant input which can be related to the Coniferales group but not to individual plant families. {beta}-Amyrin and other triterpenoid-derived triaromatic and triaromatic C-ring cleaved hydrocarbons with triterpenoid structures are thought to be characteristic for angiosperms. The relative concentrations of the triaromatic and triaromatic C-ring cleaved hydrocarbons are higher in samples 9602 (mudstone) and 9603 (coal) than samples 9601 (coal) and 9604 (mudstone) indicating samples 9602 (mudstone) and 9603 (coal) contain relatively more angiosperm derived organic matter than samples 9601 (coal) and 9604 (mudstone). The distribution patterns and the relative concentrations of saturated and aromatic diterpenoids and triterpenoids thus are valuable markers for the determination of the relative contents of biological sources of organic material in geological samples. (author)

  1. Contribution of species-specific chemical signatures to soil organic matter in Kohala, HI.

    Science.gov (United States)

    Stewart, C. E.; Amatangelo, K.; Neff, J. C.

    2008-12-01

    Soil organic matter (SOM) inherits much of its chemical structure from the dominant vegetation, including phenolic (lignin-derived), aromatic, and aliphatic (cutin and wax-derived) compounds. The Hawaiian fern species Dicranopteris decomposes more slowly than the angiosperm, Cheirodendron due to high concentrations of recalcitrant C compounds. These aliphatic fern leaf waxes are well-preserved and may comprise a large portion of the recalcitrant organic matter in these soils. Our objective was to determine the chemical signature of fern and angiosperm vegetation types and trace the preservation or loss of those compounds into the soil. We collected live tissue, litter, roots, and soil (tannin-derivatives. There was a general decrease of lignin-derived phenolic compounds from live to litter to soils and an increase in more recalcitrant, aromatic and aliphatic C. Recalcitrant fern-derived cutin and leaf waxes (alkene and alkanes structures) were evident in the soils, but clear species differences were not observed. Although ferns contain distinct lipid and wax-derived compounds, soils developed under fern do not appear to accumulate these compounds in SOM.

  2. Cycads: their evolution, toxins, herbivores and insect pollinators

    Science.gov (United States)

    Schneider, Dietrich; Wink, Michael; Sporer, Frank; Lounibos, Philip

    2002-06-01

    Palaeobiological evidence indicates that gymnosperms were wind-pollinated and that insect pollination began in angiosperms in the Lower Cretaceous (ca. 135 mya) leading to close associations between higher plants and their pollinators. Cycads, which were widespread and pervasive throughout the Mesozoic (250-65 mya) are among the most primitive living seed-plants found today. Because pollination by beetles and by thrips has now been detected in several modern cycads, it is attractive to speculate that some insects and cycads had already developed similar mutualistic interactions in the Triassic (250-205 mya), long before the advent of angiosperms. We also draw attention to another key factor in this insect-plant relationship, namely secondary, defensive plant substances which must always have controlled interspecific interactions. Cycads mainly produce toxic azoglucosides and neurotoxic non-protein amino acids (e.g. BMAA), which apparently are crucial elements in the development and maintenance of mutualism (pollination) and parasitism (herbivory) by cycad-linked herbivores. We now add new results on the uptake and storage of the main toxin, cycasin, of the Mexican cycad Zamia furfuracea by its pollinator, the weevil Rhopalotria mollis, and by a specialist herbivore of Zamia integrifolia, the aposematic Atala butterfly Eumaeus atala.

  3. Evaluation of Monocot and Eudicot Divergence Using the Sugarcane Transcriptome1[w

    Science.gov (United States)

    Vincentz, Michel; Cara, Frank A.A.; Okura, Vagner K.; da Silva, Felipe R.; Pedrosa, Guilherme L.; Hemerly, Adriana S.; Capella, Adriana N.; Marins, Mozart; Ferreira, Paulo C.; França, Suzelei C.; Grivet, Laurent; Vettore, Andre L.; Kemper, Edson L.; Burnquist, Willian L.; Targon, Maria L.P.; Siqueira, Walter J.; Kuramae, Eiko E.; Marino, Celso L.; Camargo, Luis E.A.; Carrer, Helaine; Coutinho, Luis L.; Furlan, Luiz R.; Lemos, Manoel V.F.; Nunes, Luiz R.; Gomes, Suely L.; Santelli, Roberto V.; Goldman, Maria H.; Bacci, Maurício; Giglioti, Eder A.; Thiemann, Otávio H.; Silva, Flávio H.; Van Sluys, Marie-Anne; Nobrega, Francisco G.; Arruda, Paulo; Menck, Carlos F.M.

    2004-01-01

    Over 40,000 sugarcane (Saccharum officinarum) consensus sequences assembled from 237,954 expressed sequence tags were compared with the protein and DNA sequences from other angiosperms, including the genomes of Arabidopsis and rice (Oryza sativa). Approximately two-thirds of the sugarcane transcriptome have similar sequences in Arabidopsis. These sequences may represent a core set of proteins or protein domains that are conserved among monocots and eudicots and probably encode for essential angiosperm functions. The remaining sequences represent putative monocot-specific genetic material, one-half of which were found only in sugarcane. These monocot-specific cDNAs represent either novelties or, in many cases, fast-evolving sequences that diverged substantially from their eudicot homologs. The wide comparative genome analysis presented here provides information on the evolutionary changes that underlie the divergence of monocots and eudicots. Our comparative analysis also led to the identification of several not yet annotated putative genes and possible gene loss events in Arabidopsis. PMID:15020759

  4. Depositional Environment of Mio-Pliocene Siwalik Sedimentary Strata from the Darjeeling Himalayan Foothills, India: A Palynological Approach

    Science.gov (United States)

    More, Sandip; Paruya, Dipak Kumar; Taral, Suchana; Chakraborty, Tapan; Bera, Subir

    2016-01-01

    A rich and diverse palynoassemblage recovered from the Churanthi River section (26°53' 59.3" N, 88°34' 17.2" E), Darjeeling foothills Eastern Himalaya, has yielded 87 species assigned to 69 genera. The palynoassemblage is rich in angiosperm taxa (45.63%) followed by gymnosperms (0.45%), pteridophytes (18.49%) and fungal remains (23.88%). Based on their nearest living relatives, a wet evergreen to semi-evergreen forest under a humid tropical to sub-tropical environment during the Mio-Pliocene age has been suggested. A lot of angiosperms such as Palaeosantalaceaepites, Araliaceoipollenites, Malvacearampollis, Zonocostites, Neocouperipollis, Dicolpopollis, Palmidites, Palmaepollenites, isolated salt glands of mangrove plant leaves (Heliospermopsis) and Mediaverrunites type of fungal spores, along with ichnofossils like Planolites, Palaeophycus, Skolithos, Rosselia, Ophiomorpha and Teichichnus associated with rippled mudstone-siltstone suggest an environment strongly influenced by brackish water. Primary sedimentary structures in the associated strata indicate strong wave agitation common in shallow marine setting. Some high elevation components (5.14%) such as Alnipollenites, cf. Corylus (Betulaceae), Juglanspollenites, Engelhardtioipollenites (Juglandaceae), Quercoides, Cupuliferoidaepollenites, Lithocarpus, Castanopsis (Fagaceae), Abietineaepollenites (Pinaceae) represent hinterland vegetation possibly transported to the prograding deltaic coastline by the rivers. Reworked palynotaxa (Striatopodocarpites sp., Striatites sp., Faunipollenites sp., Circumstriatites sp., Crescentipollenites sp., Cuneatisporites sp., Parasaccites sp., Scheuringipollenites sp., Rhizomaspora sp., Marsupipollenites sp., Lophotriletes sp.) of Permian age have also been recorded in the palynoassemblage (11.55%) indicating the abundance of Permian Gondwana strata in the source area. PMID:26930664

  5. Phylogeny and evolution of charophytic algae and land plants%轮藻和陆地植物系统发育及其进化

    Institute of Scientific and Technical Information of China (English)

    仇寅龙

    2008-01-01

    Charophytic algae and land plants together make up a monophyletic group, streptophytes, which represents one of the main lineages of multicellular eukaryotes and has contributed greatly to the change of the environment on earth in the Phanerozoic Eon. Significant progress has been made to understand phylogenetic relationships among members of this group by phylogenetic studies of morphological and molecular data over the last twenty-five years. Mesostigma viride is now regarded as among the earliest diverging unicellular organisms in streptophytes. Characeae are the sister group to land plants. Liverworts represent the first diverging lineage of land plants. Hornworts and lycophytes are extant representatives of bryophytes and vascular plants, respectively, when early land plants changed from gametophyte to sporophyte as the dominant generation in the life cycle. Equisetum, Psilotaceae, and ferns constitute the monophyletic group of monilophytes, which are sister to seed plants. Gnetales are related to conifers, not to angiosperms as previously thought. Amborella, Nymphaeales, Hydatellaceae, Illiciales, Trimeniaceae, and Austrobaileya represent the earliest diverging lineages of extant angiosperms. These phylogenetic results, together with recent progress on elucidating genetic and developmental aspects of the plant life cycle, multicellularity, and gravitropism, will facilitate evolutionary developmental studies of these key traits, which will help us to gain mechanistic understanding on how plants adapted to environmental challenges when they colonized the land during one of the major transitions in evolution of life.

  6. The population ecology of male gametophytes: the link between pollination and seed production.

    Science.gov (United States)

    Harder, Lawrence D; Aizen, Marcelo A; Richards, Shane A

    2016-05-01

    The fate of male gametophytes after pollen reaches stigmas links pollination to ovule fertilisation, governing subsequent siring success and seed production. Although male gametophyte performance primarily involves cellular processes, an ecological analogy may expose insights into the nature and implications of male gametophyte success. We elaborate this analogy theoretically and present empirical examples that illustrate associated insights. Specifically, we consider pollen loads on stigmas as localised populations subject to density-independent mortality and density-dependent processes as they traverse complex stylar environments. Different combinations of the timing of pollen-tube access to limiting stylar resources (simultaneous or sequential), the tube distribution among resources (repulsed or random) and the timing of density-independent mortality relative to competition (before or after) create signature relations of mean pollen-tube success and its variation among pistils to pollen receipt. Using novel nonlinear regression analyses (two-moment regression), we illustrate contrasting relations for two species, demonstrating that variety in these relations is a feature of reproductive diversity among angiosperms, rather than merely a theoretical curiosity. Thus, the details of male gametophyte ecology should shape sporophyte reproductive success and hence the dynamics and structure of angiosperm populations. PMID:26970246

  7. Proton-dependent coniferin transport, a common major transport event in differentiating xylem tissue of woody plants.

    Science.gov (United States)

    Tsuyama, Taku; Kawai, Ryo; Shitan, Nobukazu; Matoh, Toru; Sugiyama, Junji; Yoshinaga, Arata; Takabe, Keiji; Fujita, Minoru; Yazaki, Kazufumi

    2013-06-01

    Lignin biosynthesis is an essential physiological activity of vascular plants if they are to survive under various environmental stresses on land. The biosynthesis of lignin proceeds in the cell wall by polymerization of precursors; the initial step of lignin polymerization is the transportation of lignin monomers from the cytosol to the cell wall, which is critical for lignin formation. There has been much debate on the transported form of the lignin precursor, either as free monolignols or their glucosides. In this study, we performed biochemical analyses to characterize the membrane transport mechanism of lignin precursors using angiosperms, hybrid poplar (Populus sieboldii × Populus grandidentata) and poplar (Populus sieboldii), as well gymnosperms, Japanese cypress (Chamaecyparis obtusa) and pine (Pinus densiflora). Membrane vesicles prepared from differentiating xylem tissues showed clear ATP-dependent transport activity of coniferin, whereas less than 4% of the coniferin transport activity was seen for coniferyl alcohol. Bafilomycin A1 and proton gradient erasers markedly inhibited coniferin transport in hybrid poplar membrane vesicles; in contrast, vanadate had no effect. Cis-inhibition experiments suggested that this transport activity was specific for coniferin. Membrane fractionation of hybrid poplar microsomes demonstrated that transport activity was localized to the tonoplast- and endomembrane-rich fraction. Differentiating xylem of Japanese cypress exhibited almost identical transport properties, suggesting the involvement of a common endomembrane-associated proton/coniferin antiport mechanism in the lignifying tissues of woody plants, both angiosperms and gymnosperms. PMID:23585651

  8. Aridity induces super-optimal investment in leaf venation by Eucalyptus and Corymbia

    Science.gov (United States)

    Drake, Paul L.; de Boer, Hugo J.; Price, Charles A.; Veneklaas, Erik J.

    2016-04-01

    The close relationship between leaf water status and stomatal conductance implies that the hydraulic architecture of leaves poses an important constraint on carbon uptake, specifically in arid environments with high evaporative demands. However, it remains uncertain how morphological, hydraulic and photosynthetic traits are coordinated to achieve optimal leaf functioning in arid environments. Zwieniecki and Boyce (2014) proposed a generic framework on the hydraulic architecture of leaves based on the argument that water is optimally distributed when the lateral distance between neighboring water transport veins (dx) is approximately equal to the distance from these veins to the epidermis (dy), expressed as dx:dy ≈1. Many derived angiosperms realize this optimal hydraulic architecture by closely coordinating leaf vein density with leaf thickness and the lateral position of veins inside the leaf. Zwieniecki and Boyce (2014) further suggested that over-investment in veins (dx:dy water transport and photosynthesis. References Schulze, E.-D., Turner, N. C., Nicolle, D. and Schumacher, J.: Species differences in carbon isotope ratios, specific leaf area and nitrogen concentrations in leaves of Eucalyptus growing in a common garden compared with along an aridity gradient, Physiol. Plant., 127(3), 434-444, 2006. Zwieniecki, M. A. and Boyce, C. K.: Evolution of a unique anatomical precision in angiosperm leaf venation lifts constraints on vascular plant ecology, Proc. R. Soc. B Biol. Sci., 281(1779), 2014.

  9. Fossil evidence for the early ant evolution

    Science.gov (United States)

    Perrichot, Vincent; Lacau, Sébastien; Néraudeau, Didier; Nel, André

    2008-02-01

    Ants are one of the most studied insects in the world; and the literature devoted to their origin and evolution, systematics, ecology, or interactions with plants, fungi and other organisms is prolific. However, no consensus yet exists on the age estimate of the first Formicidae or on the origin of their eusociality. We review the fossil and biogeographical record of all known Cretaceous ants. We discuss the possible origin of the Formicidae with emphasis on the most primitive subfamily Sphecomyrminae according to its distribution and the Early Cretaceous palaeogeography. And we review the evidence of true castes and eusociality of the early ants regarding their morphological features and their manner of preservation in amber. The mid-Cretaceous amber forest from south-western France where some of the oldest known ants lived, corresponded to a moist tropical forest close to the shore with a dominance of gymnosperm trees but where angiosperms (flowering plants) were already diversified. This palaeoenvironmental reconstruction supports an initial radiation of ants in forest ground litter coincident with the rise of angiosperms, as recently proposed as an ecological explanation for their origin and successful evolution.

  10. Apoplastic interactions between plants and plant root intruders

    Directory of Open Access Journals (Sweden)

    Kanako eMitsumasu

    2015-08-01

    Full Text Available Numerous pathogenic or parasitic organisms attack plant roots to obtain nutrients, and the apoplast including the plant cell wall is where the plant cell meets such organisms. Root-parasitic angiosperms and nematodes are two distinct types of plant root parasites but share some common features in their strategies for breaking into plant roots. Striga and Orobanche are obligate root parasitic angiosperms that cause devastating agricultural problems worldwide. Parasitic plants form an invasion organ called a haustorium, where plant cell wall degrading enzymes (PCWDEs are highly expressed. Plant-parasitic nematodes are another type of agriculturally important plant root parasite. These nematodes breach the plant cell walls by protruding a sclerotized stylet from which PCWDEs are secreted. Responding to such parasitic invasion, host plants activate their own defense responses against parasites. Endoparasitic nematodes secrete apoplastic effectors to modulate host immune responses and to facilitate the formation of a feeding site. Apoplastic communication between hosts and parasitic plants also contributes to their interaction. Parasitic plant germination stimulants, strigolactones (SLs, are recently identified apoplastic signals that are transmitted over long distances from biosynthetic sites to functioning sites. Here, we discuss recent advances in understanding the importance of apoplastic signals and cell walls for plant-parasite interactions.

  11. [Population difference of polypores in northwest and southeast of China].

    Science.gov (United States)

    Wang, Xiao-yan; Wei, Yu-lian

    2015-10-01

    Polypores are an important group of wood-rotting fungi and play a key role in decomposing wood in the forest ecosystem. Based on field investigations and laboratory analysis, fungal flora and diversity composition of polypores in Tianshan Moutains, Qilian Mountains, Baotianman Nature Reserve and Wuyi Mountains were analyzed. In total, 72 polypore species were found in Tianshan Mountains, 99 in Qilian Mountains, 124 in Baotianman Nature Reserve and 156 in Wuyi Mountains. There were fourteen common species in the four zones. The biogeography could be divided into 4 groups at genera level of the four zones, the important elements were North temperate element and cosmopolitan element, and floristic analysis showed a distinct north temperate character. The proportion of white rot polypores in the four zones increased from northwest to southeast of China, while the proportion of brown rot polypores decreased. Polypores preferentially grew on angiosperm trees compared to gymnosperm trees. Among the four zones, polypores in Baotianman had the highest proportion of species living on angiosperm trees. Rare and threatened species in Tianshan Mountains and Qilian Mountains were mainly found on conifer trees, while in the other two zones, most rare and threatened species were found on broadleaf trees. Generally, the distinctions of these four areas were mainly affected by the forest type. PMID:26995926

  12. Strong but diverging clonality - climate relationships of different plant clades explain weak overall pattern across China

    Science.gov (United States)

    Ye, Duo; Liu, Guofang; Song, Yao-Bin; Cornwell, William K.; Dong, Ming; Cornelissen, Johannes H. C.

    2016-06-01

    The clonal strategy should be relatively important in stressful environments (i.e. of low resource availability or harsh climate), e.g. in cold habitats. However, our understanding of the distribution pattern of clonality along environmental gradients is still far from universal. The weakness and inconsistency of overall clonality-climate relationships across taxa, as reported in previous studies, may be due to different phylogenetic lineages having fundamental differences in functional traits other than clonality determining their climate response. Thus, in this study we compared the clonality-climate relationships along a latitudinal gradient within and between different lineages at several taxonomic levels, including four major angiosperm lineages (Magnoliidae, Monocotyledoneae, Superrosidae and Superasteridae), orders and families. To this aim we used a species clonality dataset for 4015 vascular plant species in 545 terrestrial communities across China. Our results revealed clear predictive patterns of clonality proportion in relation to environmental gradients for the predominant representatives of each of the taxonomic levels above, but the relationships differed in shape and strength between the 4 major angiosperm lineages, between the 12 orders and between the 12 families. These different relationships canceled out one another when all lineages at a certain taxonomic level were pooled. Our findings highlight the importance of explicitly accounting for the functional or taxonomic scale for studying variation in plant ecological strategy across environmental gradients.

  13. Palynological evidence of effects of the terminal Cretaceous event on terrestrial floras in western North America

    Science.gov (United States)

    Nichols, Douglas J.; Farley Fleming, R.; Frederiksen, Norman O.

    New and previously published palynomorph distribution data on 225 taxa from uppermost Cretaceous (K) and lowermost Tertiary (T) nonmarine strata from New Mexico to Arctic Canada and Alaska were used to evaluate the effects of the terminal Cretaceous event (TCE) on terrestrial plant life. Analyses considered presence/absence, relative abundance, species diversity, and endemism, and employed Q-mode cluster analysis. The latest Cretaceous palynoflora showed gradual, continuous variation in composition from paleolatitudes (pl) 45° to 85° N. Palynofloristic subprovinces are not easily distinguished empirically, but three are recognizable quantitatively. Abrupt disappearance of many distinctive species marked the K-T boundary, and the earliest Tertiary palynoflora was considerably reduced in diversity. However, most regionally distributed taxa, and many endemic taxa of the polar and midlatitude subprovinces, survived the TCE and three subprovinces are recognizable in the same geographic positions as in the latest Cretaceous. Relative abundances of pteridophytes and gymnosperms were slightly greater in the early Tertiary than in the latest Cretaceous, probably due in part to change in sedimentary regime, but thermophilic angiosperm taxa persisted at least as far north as pl 60° N. These data support the hypothesis that a short-lived but profound ecological crisis at the end of the Cretaceous resulted in major reorganization of the flora. The data are inconsistent with gradual climatic deterioration. Extinction was greater among angiosperms than among gymnosperms or pteridophytes, but whether or not the entire flora suffered a mass extinction remains debatable.

  14. Computer vision cracks the leaf code.

    Science.gov (United States)

    Wilf, Peter; Zhang, Shengping; Chikkerur, Sharat; Little, Stefan A; Wing, Scott L; Serre, Thomas

    2016-03-22

    Understanding the extremely variable, complex shape and venation characters of angiosperm leaves is one of the most challenging problems in botany. Machine learning offers opportunities to analyze large numbers of specimens, to discover novel leaf features of angiosperm clades that may have phylogenetic significance, and to use those characters to classify unknowns. Previous computer vision approaches have primarily focused on leaf identification at the species level. It remains an open question whether learning and classification are possible among major evolutionary groups such as families and orders, which usually contain hundreds to thousands of species each and exhibit many times the foliar variation of individual species. Here, we tested whether a computer vision algorithm could use a database of 7,597 leaf images from 2,001 genera to learn features of botanical families and orders, then classify novel images. The images are of cleared leaves, specimens that are chemically bleached, then stained to reveal venation. Machine learning was used to learn a codebook of visual elements representing leaf shape and venation patterns. The resulting automated system learned to classify images into families and orders with a success rate many times greater than chance. Of direct botanical interest, the responses of diagnostic features can be visualized on leaf images as heat maps, which are likely to prompt recognition and evolutionary interpretation of a wealth of novel morphological characters. With assistance from computer vision, leaves are poised to make numerous new contributions to systematic and paleobotanical studies. PMID:26951664

  15. Identification of WOX Family Genes in Selaginella kraussiana for Studies on Stem Cells and Regeneration in Lycophytes.

    Science.gov (United States)

    Ge, Yachao; Liu, Jie; Zeng, Minhuan; He, Jianfeng; Qin, Peng; Huang, Hai; Xu, Lin

    2016-01-01

    Plant stem cells give rise to all tissues and organs and also serve as the source for plant regeneration. The organization of plant stem cells has undergone a progressive change from simple to complex during the evolution of vascular plants. Most studies on plant stem cells have focused on model angiosperms, the most recently diverged branch of vascular plants. However, our knowledge of stem cell function in other vascular plants is limited. Lycophytes and euphyllophytes (ferns, gymnosperms, and angiosperms) are two existing branches of vascular plants that separated more than 400 million years ago. Lycophytes retain many of the features of early vascular plants. Based on genome and transcriptome data, we identified WUSCHEL-RELATED HOMEOBOX (WOX) genes in Selaginella kraussiana, a model lycophyte that is convenient for in vitro culture and observations of organ formation and regeneration. WOX genes are key players controlling stem cells in plants. Our results showed that the S. kraussiana genome encodes at least eight members of the WOX family, which represent an early stage of WOX family evolution. Identification of WOX genes in S. kraussiana could be a useful tool for molecular studies on the function of stem cells in lycophytes. PMID:26904063

  16. Review of plant biogeographic studies in Brazil

    Institute of Scientific and Technical Information of China (English)

    Pedro FIASCHI; José R. PIRANI

    2009-01-01

    Molecular phylogenetic studies have become a major area of interest in plant systematics, and their impacts on historical biogeographic hypotheses are not to be disregarded. In Brazil, most historical biogeographic studies have relied on animal phylogenies, whereas plant biogeographic studies have largely lacked a phylogenetic component, having a limited utility for historical biogeography. That country, however, is of great importance for most biogeographic studies of lowland tropical South America, and it includes areas from a number of biogeographic regions of the continent. Important biogeographic reports have been published as part of phylogenetic studies, taxonomic monographs, and regional accounts for small areas or phytogeographic domains, hut the available information is subsequently scattered and sometimes hard to find. In this paper we review some relevant angiosperm biogeographic studies in Brazil. Initially we briefly discuss the importance of other continents as source areas for the South American flora. Then we present a subdivision of Brazil into phytogeographic domains, and we cite studies that have explored the detection of biogeographic units (areas of endemism) and how they are historically related among those domains. Examples of plant taxa that could be used to test some biogeographic hypotheses are provided throughout, as well as taxa that exemplify several patterns of endemism and disjunction in the Brazilian angiosperm flora.

  17. Fossil rubber in brown coal deposits: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Mahlberg, P.G.; Stoerr, M. (Indiana University, Bloomington (USA))

    1989-01-01

    Fossil rubber strands of middle Eocene from Geiseltal and Harpke brown coal deposits in the GDR are angiospermous remains of the branched nonarticulated laticifer cell. The cis-1,4-polyisoprene rubber was cribriform in appearance indicating possibly that it polymerized around protoplasmic components during fossilization. Cell morphology and thermal analyses of rubber hydrocarbons indicate that the deposits were not subjected to high pressure or temperatures during fossilization. The similarity of profiles for hydrocarbons extractable only from the rubber indicates their presence in the original living cell and identifies the samples to be derived from the same species. Sulfur accumulated nearly all as organic sulfur to higher levels in the rubber than in the gel. Morphological and chemical data show the laticifer to be a highly specialized cell already in the Eocene and provide new insight for interpreting the age of Angiosperms. Presence of predominantly organic sulfur with greater deposition in rubber than gel indicates the unique environmental condition related to sulfur deposition and provides the basis for a better understanding of sulfur fixation in brown coal. 23 refs., 12 figs., 2 tabs.

  18. A census of nuclear cyanobacterial recruits in the plant kingdom.

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    Szabolcs Makai

    Full Text Available The plastids and mitochondria of the eukaryotic cell are of endosymbiotic origin. These events occurred ~2 billion years ago and produced significant changes in the genomes of the host and the endosymbiont. Previous studies demonstrated that the invasion of land affected plastids and mitochondria differently and that the paths of mitochondrial integration differed between animals and plants. Other studies examined the reasons why a set of proteins remained encoded in the organelles and were not transferred to the nuclear genome. However, our understanding of the functional relations of the transferred genes is insufficient. In this paper, we report a high-throughput phylogenetic analysis to identify genes of cyanobacterial origin for plants of different levels of complexity: Arabidopsis thaliana, Chlamydomonas reinhardtii, Physcomitrella patens, Populus trichocarpa, Selaginella moellendorffii, Sorghum bicolor, Oryza sativa, and Ostreococcus tauri. Thus, a census of cyanobacterial gene recruits and a study of their function are presented to better understand the functional aspects of plastid symbiogenesis. From algae to angiosperms, the GO terms demonstrated a gradual expansion over functionally related genes in the nuclear genome, beginning with genes related to thylakoids and photosynthesis, followed by genes involved in metabolism, and finally with regulation-related genes, primarily in angiosperms. The results demonstrate that DNA is supplied to the nuclear genome on a permanent basis with no regard to function, and only what is needed is kept, which thereby expands on the GO space along the related genes.

  19. Molecular evolution of the exon 2 of CHS genes and the possibility of its application to plant phylogenetic analysis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The exon 2 of chalcone synthase (CHS) gene is relatively conserved during evolution.In this study,three exon 2 fragments from two species in gymnosperm (Cycas panzhihuaensis,Ginkgo biloba) and seven from four species in angiosperm (Magnolia denudata,Salix babylonica,Nymphaea tetragona,Camellia japonica) have been amplified by PCR from genomic DNA and sequenced.Together with other 73 sequences of CHS collected from EMBL database and literature,these sequences,which embrace 19 families of gymnosperm and angiosperm,have been analyzed for their phylogenetic relations by parsimony method.The result indicated that sequences from the same systematic family usually grouped together except those from Theaceae,Magnoliaceae and Nymphaeaceae.The relative rate test revealed the rate heterogeneity of CHS genes among the families.For the nucleotide substitution the sequences from Asteraceae and Solanaceae evolve faster than those from the other families analyzed while the sequences from Poaceae,Asteraceae and Solanaceae evolve faster for the nonsynonymous substitution.These results suggest that the duplication and extinction events of CHS genes are different among systematic families,therefore it seems impractical to look for orthologous sequences from CHS genes to study plant phylogeny at the family level and/or above.However,it is possible to do so below the family level.

  20. Increased diversification rates follow shifts to bisexuality in liverworts.

    Science.gov (United States)

    Laenen, Benjamin; Machac, Antonin; Gradstein, S Robbert; Shaw, Blanka; Patiño, Jairo; Désamoré, Aurélie; Goffinet, Bernard; Cox, Cymon J; Shaw, A Jonathan; Vanderpoorten, Alain

    2016-05-01

    Shifts in sexual systems are one of the key drivers of species diversification. In contrast to angiosperms, unisexuality prevails in bryophytes. Here, we test the hypotheses that bisexuality evolved from an ancestral unisexual condition and is a key innovation in liverworts. We investigate whether shifts in sexual systems influence diversification using hidden state speciation and extinction analysis (HiSSE). This new method compares the effects of the variable of interest to the best-fitting latent variable, yielding robust and conservative tests. We find that the transitions in sexual systems are significantly biased toward unisexuality, even though bisexuality is coupled with increased diversification. Sexual systems are strongly conserved deep within the liverwort tree but become much more labile toward the present. Bisexuality appears to be a key innovation in liverworts. Its effects on diversification are presumably mediated by the interplay of high fertilization rates, massive spore production and long-distance dispersal, which may separately or together have facilitated liverwort speciation, suppressed their extinction, or both. Importantly, shifts in liverwort sexual systems have the opposite effect when compared to angiosperms, leading to contrasting diversification patterns between the two groups. The high prevalence of unisexuality among liverworts suggests, however, a strong selection for sexual dimorphism. PMID:27074401

  1. Aridity induces super-optimal investment in leaf venation by Eucalyptus and Corymbia

    Science.gov (United States)

    Drake, Paul L.; de Boer, Hugo J.; Price, Charles A.; Veneklaas, Erik J.

    2016-04-01

    The close relationship between leaf water status and stomatal conductance implies that the hydraulic architecture of leaves poses an important constraint on carbon uptake, specifically in arid environments with high evaporative demands. However, it remains uncertain how morphological, hydraulic and photosynthetic traits are coordinated to achieve optimal leaf functioning in arid environments. Zwieniecki and Boyce (2014) proposed a generic framework on the hydraulic architecture of leaves based on the argument that water is optimally distributed when the lateral distance between neighboring water transport veins (dx) is approximately equal to the distance from these veins to the epidermis (dy), expressed as dx:dy ≈1. Many derived angiosperms realize this optimal hydraulic architecture by closely coordinating leaf vein density with leaf thickness and the lateral position of veins inside the leaf. Zwieniecki and Boyce (2014) further suggested that over-investment in veins (dx:dy Plant., 127(3), 434-444, 2006. Zwieniecki, M. A. and Boyce, C. K.: Evolution of a unique anatomical precision in angiosperm leaf venation lifts constraints on vascular plant ecology, Proc. R. Soc. B Biol. Sci., 281(1779), 2014.

  2. Tc1-like transposable elements in plant genomes

    Science.gov (United States)

    2014-01-01

    Background The Tc1/mariner superfamily of transposable elements (TEs) is widespread in animal genomes. Mariner-like elements, which bear a DDD triad catalytic motif, have been identified in a wide range of flowering plant species. However, as the founding member of the superfamily, Tc1-like elements that bear a DD34E triad catalytic motif are only known to unikonts (animals, fungi, and Entamoeba). Results Here we report the identification of Tc1-like elements (TLEs) in plant genomes. These elements bear the four terminal nucleotides and the characteristic DD34E triad motif of Tc1 element. The two TLE families (PpTc1, PpTc2) identified in the moss (Physcomitrella patens) genome contain highly similar copies. Multiple copies of PpTc1 are actively transcribed and the transcripts encode intact full length transposase coding sequences. TLEs are also found in angiosperm genome sequence databases of rice (Oryza sativa), dwarf birch (Betula nana), cabbage (Brassica rapa), hemp (Cannabis sativa), barley (Hordium valgare), lettuce (Lactuta sativa), poplar (Populus trichocarpa), pear (Pyrus x bretschneideri), and wheat (Triticum urartu). Conclusions This study extends the occurrence of TLEs to the plant phylum. The elements in the moss genome have amplified recently and may still be capable of transposition. The TLEs are also present in angiosperm genomes, but apparently much less abundant than in moss. PMID:24926322

  3. Characterisation of detergent-insoluble membranes in pollen tubes of Nicotiana tabacum (L.

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    Alessandra Moscatelli

    2015-02-01

    Full Text Available Pollen tubes are the vehicle for sperm cell delivery to the embryo sac during fertilisation of Angiosperms. They provide an intriguing model for unravelling mechanisms of growing to extremes. The asymmetric distribution of lipids and proteins in the pollen tube plasma membrane modulates ion fluxes and actin dynamics and is maintained by a delicate equilibrium between exocytosis and endocytosis. The structural constraints regulating polarised secretion and asymmetric protein distribution on the plasma membrane are mostly unknown. To address this problem, we investigated whether ordered membrane microdomains, namely membrane rafts, might contribute to sperm cell delivery. Detergent insoluble membranes, rich in sterols and sphingolipids, were isolated from tobacco pollen tubes. MALDI TOF/MS analysis revealed that actin, prohibitins and proteins involved in methylation reactions and in phosphoinositide pattern regulation are specifically present in pollen tube detergent insoluble membranes. Tubulins, voltage-dependent anion channels and proteins involved in membrane trafficking and signalling were also present. This paper reports the first evidence of membrane rafts in Angiosperm pollen tubes, opening new perspectives on the coordination of signal transduction, cytoskeleton dynamics and polarised secretion.

  4. A Paleocene lowland macroflora from Patagonia reveals significantly greater richness than North American analogs

    Science.gov (United States)

    Iglesias, Ari; Wilf, Peter; Johnson, Kirk R.; Zamuner, Alba B.; Rubén Cúneo, N.; Matheos, Sergio D.; Singer, Bradley S.

    2007-10-01

    Few South American macrofloras of Paleocene age are known, and this limits our knowledge of diversity and composition between the end-Cretaceous event and the Eocene appearance of high floral diversity. We report new, unbiased collections of 2516 compression specimens from the Paleocene Salamanca Formation (ca. 61.7 Ma) from two localities in the Palacio de los Loros exposures in southern Chubut, Patagonia, Argentina. Our samples reveal considerably greater richness than was previously known from the Paleocene of Patagonia, including 36 species of angiosperm leaves as well as angiosperm fruits, flowers, and seeds; ferns; and conifer leaves, cones, and seeds. The floras, which are from siltstone and sandstone channel-fills deposited on low-relief floodplain landscapes in a humid, warm temperate climate, are climatically and paleoenvironmentally comparable to many quantitatively collected Paleocene floras from the Western Interior of North America. Adjusted for sample size, there are >50% more species at each Palacio de los Loros quarry than in any comparable U.S. Paleocene sample. These results indicate more vibrant terrestrial ecosystems in Patagonian than in North American floodplain environments ˜4 m.y. after the end-Cretaceous extinction, and they push back the time line 10 m.y. for the evolution of high floral diversity in South America. The cause of the dis parity is unknown but could involve reduced impact effects because of greater distance from the Chicxulub site, higher latest Cretaceous diversity, or faster recovery or immigration rates.

  5. Reconstruction of the charophyte community of Lake Shinji by oospore collection

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    Komuro T.

    2016-01-01

    Full Text Available Submerged aquatic vegetation (SAV aids in maintaining a clear stable state in shallow lakes. However, charophytes are more effective in increasing transparency compared to angiosperms. Lake Shinji was more transparent prior to the beginning of herbicide use for rice weed control in the mid-1950s, because its bottom was covered by SAV up to 3 m depth. Although Chara braunii C.C. Gmelin and Nitella hyaline (De Candolle C. Agardh were recorded in the 1960s, there are no reports on SAV in the 1950s. Therefore, in the present study, we aimed to show that the SAV of Lake Shinji was mostly composed of charophytes prior to the 1950s, by conducting a seed analysis. We obtained charophyte oospores from the sediment, but seeds of angiosperms were not identified. In addition to C. braunii that was previously recorded in Lake Shinji, we also found two newly identified species, Chara corallina Willdenow  and Chara fibrosa C. Agardh ex Bruzelius. Overall, this study indicates that seed analysis is helpful in reconstructing the former flora of Lake Shinji.

  6. Pollen grains in quaternary sediments from the Campos Basin, state of Rio de Janeiro, Brazil: Core BU-91-GL-05

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    Aline Gonçalves de Freitas

    2013-12-01

    Full Text Available Here, we describe pollen grains extracted from a Pleistocene-Holocene sediment core (BU-91-GL-05; 22°48'45"S; 41°54'13"W taken from the Albacora Slope (22°48'45"S; 41°54'13"W, located in the Campos Basin of the northern region of the state of Rio de Janeiro, Brazil. The analysis resulted in the identification and morphological description of 46 types of pollen: one of a gymnosperm genus (Podocarpus; and 45 of angiosperm taxa across 27 families-one family of monocotyledons (Poaceae and 26 families (30 types of dicotyledons. The most common angiosperm families were Amaranthaceae (Chenopodium, Amaranthus and Gomphrena; Fabaceae (Fabaceae type, Bauhinia, Inga and Canavalia; Malpighiaceae (Tetrapteris, Heteropteris and Peixotoa; Malvaceae (Sida, Abutilon, Hibiscus and Pseudobombax; Rubiaceae (Faramea, Borreria and Psychotria; Asteraceae (Eupatorium and tribe Vernonieae; Bignoniaceae (Bignoniaceae type, Adenocalymma and Tabebuia; and Onagraceae (Fuchsia and Ludwigia. The palynoflora in this study are associated with dense montane and submontane Atlantic Forest, semideciduous forest and restinga (coastal woodland, all of which are present in the state of Rio de Janeiro. Palynological analysis can provide important data about paleovegetation and paleoclimatic changes in the studied area during the Quaternary, specifically in the last 145,000 years.

  7. Optimal allocation of leaf epidermal area for gas exchange.

    Science.gov (United States)

    de Boer, Hugo J; Price, Charles A; Wagner-Cremer, Friederike; Dekker, Stefan C; Franks, Peter J; Veneklaas, Erik J

    2016-06-01

    A long-standing research focus in phytology has been to understand how plants allocate leaf epidermal space to stomata in order to achieve an economic balance between the plant's carbon needs and water use. Here, we present a quantitative theoretical framework to predict allometric relationships between morphological stomatal traits in relation to leaf gas exchange and the required allocation of epidermal area to stomata. Our theoretical framework was derived from first principles of diffusion and geometry based on the hypothesis that selection for higher anatomical maximum stomatal conductance (gsmax ) involves a trade-off to minimize the fraction of the epidermis that is allocated to stomata. Predicted allometric relationships between stomatal traits were tested with a comprehensive compilation of published and unpublished data on 1057 species from all major clades. In support of our theoretical framework, stomatal traits of this phylogenetically diverse sample reflect spatially optimal allometry that minimizes investment in the allocation of epidermal area when plants evolve towards higher gsmax . Our results specifically highlight that the stomatal morphology of angiosperms evolved along spatially optimal allometric relationships. We propose that the resulting wide range of viable stomatal trait combinations equips angiosperms with developmental and evolutionary flexibility in leaf gas exchange unrivalled by gymnosperms and pteridophytes. PMID:26991124

  8. Depositional Environment of Mio-Pliocene Siwalik Sedimentary Strata from the Darjeeling Himalayan Foothills, India: A Palynological Approach.

    Science.gov (United States)

    More, Sandip; Paruya, Dipak Kumar; Taral, Suchana; Chakraborty, Tapan; Bera, Subir

    2016-01-01

    A rich and diverse palynoassemblage recovered from the Churanthi River section (26°53' 59.3" N, 88°34' 17.2" E), Darjeeling foothills Eastern Himalaya, has yielded 87 species assigned to 69 genera. The palynoassemblage is rich in angiosperm taxa (45.63%) followed by gymnosperms (0.45%), pteridophytes (18.49%) and fungal remains (23.88%). Based on their nearest living relatives, a wet evergreen to semi-evergreen forest under a humid tropical to sub-tropical environment during the Mio-Pliocene age has been suggested. A lot of angiosperms such as Palaeosantalaceaepites, Araliaceoipollenites, Malvacearampollis, Zonocostites, Neocouperipollis, Dicolpopollis, Palmidites, Palmaepollenites, isolated salt glands of mangrove plant leaves (Heliospermopsis) and Mediaverrunites type of fungal spores, along with ichnofossils like Planolites, Palaeophycus, Skolithos, Rosselia, Ophiomorpha and Teichichnus associated with rippled mudstone-siltstone suggest an environment strongly influenced by brackish water. Primary sedimentary structures in the associated strata indicate strong wave agitation common in shallow marine setting. Some high elevation components (5.14%) such as Alnipollenites, cf. Corylus (Betulaceae), Juglanspollenites, Engelhardtioipollenites (Juglandaceae), Quercoides, Cupuliferoidaepollenites, Lithocarpus, Castanopsis (Fagaceae), Abietineaepollenites (Pinaceae) represent hinterland vegetation possibly transported to the prograding deltaic coastline by the rivers. Reworked palynotaxa (Striatopodocarpites sp., Striatites sp., Faunipollenites sp., Circumstriatites sp., Crescentipollenites sp., Cuneatisporites sp., Parasaccites sp., Scheuringipollenites sp., Rhizomaspora sp., Marsupipollenites sp., Lophotriletes sp.) of Permian age have also been recorded in the palynoassemblage (11.55%) indicating the abundance of Permian Gondwana strata in the source area. PMID:26930664

  9. Dissecting the molecular signatures of apical cell-type shoot meristems from two ancient land plant lineages.

    Science.gov (United States)

    Frank, Margaret H; Edwards, Molly B; Schultz, Eric R; McKain, Michael R; Fei, Zhangjun; Sørensen, Iben; Rose, Jocelyn K C; Scanlon, Michael J

    2015-08-01

    Shoot apical meristem (SAM) structure varies markedly within the land plants. The SAMs of many seedless vascular plants contain a conspicuous inverted, pyramidal cell called the apical cell (AC), which is unidentified in angiosperms. In this study, we use transcriptomic sequencing with precise laser microdissections of meristem subdomains to define the molecular signatures of anatomically distinct zones from the AC-type SAMs of a lycophyte (Selaginella moellendorffii) and a monilophyte (Equisetum arvense). The two model species for this study represent vascular plant lineages that diverged > 400 million yr ago. Our data comprise comprehensive molecular signatures for the distinct subdomains within AC-type SAMs, an anatomical anomaly whose functional significance has been debated in the botanical literature for over two centuries. Moreover, our data provide molecular support for distinct gene expression programs between the AC-type SAMs of Selaginella and Equisetum, as compared with the SAM transcriptome of the angiosperm maize. The results are discussed in light of the functional significance and evolutionary success of the AC-type SAM within the embryophytes. PMID:25900772

  10. Shades of red: bird-pollinated flowers target the specific colour discrimination abilities of avian vision.

    Science.gov (United States)

    Shrestha, Mani; Dyer, Adrian G; Boyd-Gerny, Skye; Wong, Bob B M; Burd, Martin

    2013-04-01

    Colour signals are a major cue in putative pollination syndromes. There is evidence that the reflectance spectra of many flowers target the distinctive visual discrimination abilities of hymenopteran insects, but far less is known about bird-pollinated flowers. Birds are hypothesized to exert different selective pressures on floral colour compared with hymenopterans because of differences in their visual systems. We measured the floral reflectance spectra of 206 Australian angiosperm species whose floral visitors are known from direct observation rather than inferred from floral characteristics. We quantified the match between these spectra and the hue discrimination abilities of hymenopteran and avian vision, and analysed these metrics in a phylogenetically informed comparison of flowers in different pollination groups. We show that bird-visited flowers and insect-visited flowers differ significantly from each other in the chromatic cues they provide, and that the differences are concentrated near wavelengths of optimal colour discrimination by whichever class of pollinator visits the flowers. Our results indicate that angiosperms have evolved the spectral signals most likely to reinforce their pollinators' floral constancy (the tendency of individual pollinators to visit flowers of the same species) in communities of similarly coloured floral competitors. PMID:23368754

  11. Evolution of genome size and complexity in Pinus.

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    Alison M Morse

    Full Text Available BACKGROUND: Genome evolution in the gymnosperm lineage of seed plants has given rise to many of the most complex and largest plant genomes, however the elements involved are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: Gymny is a previously undescribed retrotransposon family in Pinus that is related to Athila elements in Arabidopsis. Gymny elements are dispersed throughout the modern Pinus genome and occupy a physical space at least the size of the Arabidopsis thaliana genome. In contrast to previously described retroelements in Pinus, the Gymny family was amplified or introduced after the divergence of pine and spruce (Picea. If retrotransposon expansions are responsible for genome size differences within the Pinaceae, as they are in angiosperms, then they have yet to be identified. In contrast, molecular divergence of Gymny retrotransposons together with other families of retrotransposons can account for the large genome complexity of pines along with protein-coding genic DNA, as revealed by massively parallel DNA sequence analysis of Cot fractionated genomic DNA. CONCLUSIONS/SIGNIFICANCE: Most of the enormous genome complexity of pines can be explained by divergence of retrotransposons, however the elements responsible for genome size variation are yet to be identified. Genomic resources for Pinus including those reported here should assist in further defining whether and how the roles of retrotransposons differ in the evolution of angiosperm and gymnosperm genomes.

  12. Characterisation of sunflower-21 (SF21) genes expressed in pollen and pistil of Senecio squalidus (Asteraceae) and their relationship with other members of the SF21 gene family.

    Science.gov (United States)

    Allen, Alexandra M; Lexer, Christian; Hiscock, Simon J

    2010-09-01

    Two related flower-expressed gene copies belonging to the SF21 (sunflower-21) gene family have been isolated from Senecio squalidus (Oxford Ragwort, Asteraceae). These gene copies are differentially expressed in pollen and pistil tissues; ORSF21B (Oxford Ragwort SF21B) is expressed exclusively in mature pollen, whereas ORSF21A (Oxford Ragwort SF21A) is expressed in the transmitting tissue of the style, where it is developmentally regulated. Despite differences in expression, the coding regions of ORSF21A and ORSF21B are highly similar. Amino acid sequence alignments of SF21 genes from a number of angiosperm species indicate that this gene family is conserved in flowering plants and may play an important role in reproductive processes in a wide range of taxa. Phylogenetic analysis of SF21 nucleotide sequence alignments supports this theory, and indicates a complicated history of evolution of this gene family in angiosperms. The putative roles of SF21 genes in reproduction and pollen-pistil interactions are discussed. PMID:20182753

  13. Evolution of fruit development genes in flowering plants

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    Natalia ePabón-Mora

    2014-06-01

    Full Text Available The genetic mechanisms regulating dry fruit development and opercular dehiscence have been identified in Arabidopsis thaliana. In the bicarpellate silique, valve elongation and differentiation is controlled by FRUITFULL (FUL that antagonizes SHATTERPROOF1-2 (SHP1/ SHP2 and INDEHISCENT (IND at the dehiscence zone where they control normal lignification. SHP1/2 are also repressed by REPLUMLESS (RPL, responsible for replum formation. Similarly, FUL indirectly controls two other factors ALCATRAZ (ALC and SPATULA (SPT that function in the proper formation of the separation layer. FUL and SHP1/2 belong to the MADS-box family, IND and ALC belong to the bHLH family and RPL belongs to the homeodomain family, all of which are large transcription factor families. These families have undergone numerous duplications and losses in plants, likely accompanied by functional changes. Functional analyses of homologous genes suggest that this network is fairly conserved in Brassicaceae and less conserved in other core eudicots. Only the MADS box genes have been functionally characterized in basal eudicots and suggest partial conservation of the functions recorded for Brassicaceae. Here we do a comprehensive search of SHP, IND, ALC, SPT and RPL homologs across core-eudicots, basal eudicots, monocots and basal angiosperms. Based on gene-tree analyses we hypothesize what parts of the network for fruit development in Brassicaceae, in particular regarding direct and indirect targets of FUL, might be conserved across angiosperms.

  14. Evolution of fruit development genes in flowering plants.

    Science.gov (United States)

    Pabón-Mora, Natalia; Wong, Gane Ka-Shu; Ambrose, Barbara A

    2014-01-01

    The genetic mechanisms regulating dry fruit development and opercular dehiscence have been identified in Arabidopsis thaliana. In the bicarpellate silique, valve elongation and differentiation is controlled by FRUITFULL (FUL) that antagonizes SHATTERPROOF1-2 (SHP1/SHP2) and INDEHISCENT (IND) at the dehiscence zone where they control normal lignification. SHP1/2 are also repressed by REPLUMLESS (RPL), responsible for replum formation. Similarly, FUL indirectly controls two other factors ALCATRAZ (ALC) and SPATULA (SPT) that function in the proper formation of the separation layer. FUL and SHP1/2 belong to the MADS-box family, IND and ALC belong to the bHLH family and RPL belongs to the homeodomain family, all of which are large transcription factor families. These families have undergone numerous duplications and losses in plants, likely accompanied by functional changes. Functional analyses of homologous genes suggest that this network is fairly conserved in Brassicaceae and less conserved in other core eudicots. Only the MADS box genes have been functionally characterized in basal eudicots and suggest partial conservation of the functions recorded for Brassicaceae. Here we do a comprehensive search of SHP, IND, ALC, SPT, and RPL homologs across core-eudicots, basal eudicots, monocots and basal angiosperms. Based on gene-tree analyses we hypothesize what parts of the network for fruit development in Brassicaceae, in particular regarding direct and indirect targets of FUL, might be conserved across angiosperms. PMID:25018763

  15. An integrated approach to demonstrating the ANR pathway of proanthocyanidin biosynthesis in plants.

    Science.gov (United States)

    Peng, Qing-Zhong; Zhu, Yue; Liu, Zhong; Du, Ci; Li, Ke-Gang; Xie, De-Yu

    2012-09-01

    Proanthocyanidins (PAs) are oligomers or polymers of plant flavan-3-ols and are important to plant adaptation in extreme environmental conditions. The characterization of anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR) has demonstrated the different biogenesis of four stereo-configurations of flavan-3-ols. It is important to understand whether ANR and the ANR pathway widely occur in the plant kingdom. Here, we report an integrated approach to demonstrate the ANR pathway in plants. This includes different methods to extract native ANR from different tissues of eight angiosperm plants (Lotus corniculatus, Desmodium uncinatum, Medicago sativa, Hordeum vulgare, Vitis vinifera, Vitis bellula, Parthenocissus heterophylla, and Cerasus serrulata) and one fern plant (Dryopteris pycnopteroides), a general enzymatic analysis approach to demonstrate the ANR activity, high-performance liquid chromatography-based fingerprinting to demonstrate (-)-epicatechin and other flavan-3-ol molecules, and phytochemical analysis of PAs. Results demonstrate that in addition to leaves of M. sativa, tissues of other eight plants contain an active ANR pathway. Particularly, the leaves, flowers and pods of D. uncinatum, which is a model plant to study LAR and the LAR pathways, are demonstrated to express an active ANR pathway. This finding suggests that the ANR pathway involves PA biosynthesis in D. uncinatum. In addition, a sequence BLAST analysis reveals that ANR homologs have been sequenced in plants from both gymnosperms and angiosperms. These data show that the ANR pathway to PA biosynthesis occurs in both seed and seedless vascular plants. PMID:22678031

  16. Ferns: the missing link in shoot evolution and development

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    Andrew Robert George Plackett

    2015-11-01

    Full Text Available Shoot development in land plants is a remarkably complex process that gives rise to an extreme diversity of forms. Our current understanding of shoot developmental mechanisms comes almost entirely from studies of angiosperms (flowering plants, the most recently diverged plant lineage. Shoot development in angiosperms is based around a layered multicellular apical meristem that produces lateral organs and/or secondary meristems from populations of founder cells at its periphery. In contrast, non-seed plant shoots develop from either single apical initials or from a small population of morphologically distinct apical cells. Although developmental and molecular information is becoming available for non-flowering plants, such as the model moss Physcomitrella patens, making valid comparisons between highly divergent lineages is extremely challenging. As sister group to the seed plants, the monilophytes (ferns and relatives represent an excellent phylogenetic midpoint of comparison for unlocking the evolution of shoot developmental mechanisms, and recent technical advances have finally made transgenic analysis possible in the emerging model fern Ceratopteris richardii. This review compares and contrasts our current understanding of shoot development in different land plant lineages with the aim of highlighting the potential role that the fern C. richardii could play in shedding light on the evolution of underlying genetic regulatory mechanisms.

  17. Mutations in AtPS1 (Arabidopsis thaliana parallel spindle 1 lead to the production of diploid pollen grains.

    Directory of Open Access Journals (Sweden)

    Isabelle d'Erfurth

    2008-11-01

    Full Text Available Polyploidy has had a considerable impact on the evolution of many eukaryotes, especially angiosperms. Indeed, most--if not all-angiosperms have experienced at least one round of polyploidy during the course of their evolution, and many important crop plants are current polyploids. The occurrence of 2n gametes (diplogametes in diploid populations is widely recognised as the major source of polyploid formation. However, limited information is available on the genetic control of diplogamete production. Here, we describe the isolation and characterisation of the first gene, AtPS1 (Arabidopsis thaliana Parallel Spindle 1, implicated in the formation of a high frequency of diplogametes in plants. Atps1 mutants produce diploid male spores, diploid pollen grains, and spontaneous triploid plants in the next generation. Female meiosis is not affected in the mutant. We demonstrated that abnormal spindle orientation at male meiosis II leads to diplogamete formation. Most of the parent's heterozygosity is therefore conserved in the Atps1 diploid gametes, which is a key issue for plant breeding. The AtPS1 protein is conserved throughout the plant kingdom and carries domains suggestive of a regulatory function. The isolation of a gene involved in diplogamete production opens the way for new strategies in plant breeding programmes and progress in evolutionary studies.

  18. Occurrence and evolutionary inferences about Kranz anatomy in Cyperaceae (Poales).

    Science.gov (United States)

    Martins, Shirley; Alves, Marccus; Scatena, Vera L

    2015-01-01

    Cyperaceae is an angiosperm family with the greatest diversity of species with Kranz anatomy. Four different types of Kranz anatomy (chlorocyperoid, eleocharoid, fimbristyloid and rhynchosporoid) have been described for this angiosperm family, and the occurrence and structural characteristics of these types are important to trace evolutionary hypotheses. The purpose of this study was to examine the available data on Cyperaceae Kranz anatomy, emphasizing taxonomy, geographic distribution, habitat and anatomy, to infer the potential origin of the Kranz anatomy in this family. The results showed that the four types of Kranz anatomy (associated with C4 photosynthesis) in Cyperaceae emerged numerous times in unrelated phylogenetic groups. However, the convergence of these anatomical types, except rhynchosporoid, was observed in certain groups. Thus, the diverse origin of these species might result from different environmental pressures that promote photorespiration. Greater variation in occurrence of Kranz anatomy and anatomical types was observed in Eleocharis, whose emergence of the C4 pathway was recent compared with other genera in the family, and the species of this genus are located in aquatic environments. PMID:26628020

  19. Influence of Drought on Mesophyll Resistance to CO2 Diffusion and its Impact on Water-Use Efficiency in Trees

    Science.gov (United States)

    Guo, J.; Beverly, D.; Cook, C.; Ewers, B. E.; Williams, D. G.

    2015-12-01

    The resistance to CO2 diffusion inside leaves (mesophyll resistance; rm) during photosynthesis is often comparable in magnitude to stomatal diffusion resistance, and varies among species and across environmental conditions. Consequently, photosynthesis is strongly limited by rm at low internal CO2 partial pressures, such that its variation may determine patterns of leaf water-use efficiency (WUE). Reduction in stomatal conductance with drought typically increases WUE, but also decreases photosynthesis. In theory, the decrease in photosynthesis could be countered by reduction in rm while maintaining high WUE. It is still uncertain how drought-related changes in rm affect short- and long-term WUE strategies of different tree species. We conducted field observations of instantaneous WUE and 13C discrimination in two dominant conifer species (Pinus contorta and Picea engelmannii) in SE Wyoming over the seasonal dry-down period in the summer of 2015. rm was examined by on-line 13C discrimination using isotope laser spectroscopy. Controlled environment studies on three conifer species (P. contorta, P. engelmannii, and Abies lasiocarpa) and one angiosperm (Populus tremuloides) are in progress. We hypothesize that the plasticity of rm in response to drought accounts for significant adjustments in photosynthetic capacity and WUE. Needle leaf conifers are known to have relatively high rm, and we expect them to show greater improvements in photosynthesis and WUE when rm is decreased compared to angiosperm tree species.

  20. Coevolution between Nuclear-Encoded DNA Replication, Recombination, and Repair Genes and Plastid Genome Complexity.

    Science.gov (United States)

    Zhang, Jin; Ruhlman, Tracey A; Sabir, Jamal S M; Blazier, John Chris; Weng, Mao-Lun; Park, Seongjun; Jansen, Robert K

    2016-01-01

    Disruption of DNA replication, recombination, and repair (DNA-RRR) systems has been hypothesized to cause highly elevated nucleotide substitution rates and genome rearrangements in the plastids of angiosperms, but this theory remains untested. To investigate nuclear-plastid genome (plastome) coevolution in Geraniaceae, four different measures of plastome complexity (rearrangements, repeats, nucleotide insertions/deletions, and substitution rates) were evaluated along with substitution rates of 12 nuclear-encoded, plastid-targeted DNA-RRR genes from 27 Geraniales species. Significant correlations were detected for nonsynonymous (dN) but not synonymous (dS) substitution rates for three DNA-RRR genes (uvrB/C, why1, and gyrA) supporting a role for these genes in accelerated plastid genome evolution in Geraniaceae. Furthermore, correlation between dN of uvrB/C and plastome complexity suggests the presence of nucleotide excision repair system in plastids. Significant correlations were also detected between plastome complexity and 13 of the 90 nuclear-encoded organelle-targeted genes investigated. Comparisons revealed significant acceleration of dN in plastid-targeted genes of Geraniales relative to Brassicales suggesting this correlation may be an artifact of elevated rates in this gene set in Geraniaceae. Correlation between dN of plastid-targeted DNA-RRR genes and plastome complexity supports the hypothesis that the aberrant patterns in angiosperm plastome evolution could be caused by dysfunction in DNA-RRR systems. PMID:26893456

  1. Origins of flower morphology.

    Science.gov (United States)

    Endress, P K

    2001-08-15

    Flowers evolved in many steps, probably starting long before flowering plants (angiophytes) originated. Certain parts of flowers are conservative and have not changed much during evolution; others are evolutionarily highly plastic. Here conservative features are discussed and an attempt is made to trace them back through their evolutionary history. Microsporangia and ovules (which develop into seeds) are preangiophyte floral elements. Angiospermy, combined with postgenital fusion, was the most prominent key innovation in angiophytes. Angiospermy and thecal organization of stamens originated earlier than all clades of extant angiosperms (the crown group of angiophytes). Differentiation of a perianth into calyx and corolla and syncarpy appeared after the first branching of the basalmost clades of extant angiosperms. Sympetaly and floral tubes as well as tenuinucellar, unitegmic ovules originated as major innovations in the clade that led to asterids. An obvious trend in flower evolution is increased synorganisation of parts, which led to new structures. Fixation of floral organ number and position was a precondition for synorganization. Concomitantly, plasticity changed from number and position of organs to shape of the new structures. Character distribution mapped onto cladograms indicates that key innovations do not appear suddenly, but start with trials and only later become deeply rooted genetically in the organization. This is implied from the common occurrence of reversals in the early history of an innovation. J. Exp. Zool. (Mol. Dev. Evol.) 291:105-115, 2001. PMID:11479912

  2. Back to the sea twice: identifying candidate plant genes for molecular evolution to marine life

    Directory of Open Access Journals (Sweden)

    Reusch Thorsten BH

    2011-01-01

    Full Text Available Abstract Background Seagrasses are a polyphyletic group of monocotyledonous angiosperms that have adapted to a completely submerged lifestyle in marine waters. Here, we exploit two collections of expressed sequence tags (ESTs of two wide-spread and ecologically important seagrass species, the Mediterranean seagrass Posidonia oceanica (L. Delile and the eelgrass Zostera marina L., which have independently evolved from aquatic ancestors. This replicated, yet independent evolutionary history facilitates the identification of traits that may have evolved in parallel and are possible instrumental candidates for adaptation to a marine habitat. Results In our study, we provide the first quantitative perspective on molecular adaptations in two seagrass species. By constructing orthologous gene clusters shared between two seagrasses (Z. marina and P. oceanica and eight distantly related terrestrial angiosperm species, 51 genes could be identified with detection of positive selection along the seagrass branches of the phylogenetic tree. Characterization of these positively selected genes using KEGG pathways and the Gene Ontology uncovered that these genes are mostly involved in translation, metabolism, and photosynthesis. Conclusions These results provide first insights into which seagrass genes have diverged from their terrestrial counterparts via an initial aquatic stage characteristic of the order and to the derived fully-marine stage characteristic of seagrasses. We discuss how adaptive changes in these processes may have contributed to the evolution towards an aquatic and marine existence.

  3. Evolutionary patterns of volatile terpene emissions across 202 tropical tree species.

    Science.gov (United States)

    Courtois, Elodie A; Dexter, Kyle G; Paine, Charles Eliot Timothy; Stien, Didier; Engel, Julien; Baraloto, Christopher; Chave, Jérôme

    2016-05-01

    Plant responses to natural enemies include formation of secondary metabolites acting as direct or indirect defenses. Volatile terpenes represent one of the most diverse groups of secondary metabolites. We aimed to explore evolutionary patterns of volatile terpene emission. We measured the composition of damage-induced volatile terpenes from 202 Amazonian tree species, spanning the angiosperm phylogeny. Volatile terpenes were extracted with solid-phase micro extraction and desorbed in a gas chromatography-mass spectrometry for compound identification. The chemical diversity of the terpene blend showed a strong phylogenetic signal as closely related species emitted a similar number of compounds. Closely related species also tended to have compositionally similar blends, although this relationship was weak. Meanwhile, the ability to emit a given compound showed no significant phylogenetic signal for 200 of 286 compounds, indicating a high rate of diversification in terpene synthesis and/or great variability in their expression. Three lineages (Magnoliales, Laurales, and Sapindales) showed exceptionally high rates of terpene diversification. Of the 70 compounds found in >10% of their species, 69 displayed significant correlated evolution with at least one other compound. These results provide insights into the complex evolutionary history of volatile terpenes in angiosperms, while highlighting the need for further research into this important class of compounds. PMID:27069586

  4. The role of forest trees and their mycorrhizal fungi in carbonate rock weathering and its significance for global carbon cycling.

    Science.gov (United States)

    Thorley, Rachel M S; Taylor, Lyla L; Banwart, Steve A; Leake, Jonathan R; Beerling, David J

    2015-09-01

    On million-year timescales, carbonate rock weathering exerts no net effect on atmospheric CO2 concentration. However, on timescales of decades-to-centuries, it can contribute to sequestration of anthropogenic CO2 and increase land-ocean alkalinity flux, counteracting ocean acidification. Historical evidence indicates this flux is sensitive to land use change, and recent experimental evidence suggests that trees and their associated soil microbial communities are major drivers of continental mineral weathering. Here, we review key physical and chemical mechanisms by which the symbiotic mycorrhizal fungi of forest tree roots potentially enhance carbonate rock weathering. Evidence from our ongoing field study at the UK's national pinetum confirms increased weathering of carbonate rocks by a wide range of gymnosperm and angiosperm tree species that form arbuscular (AM) or ectomycorrhizal (EM) fungal partnerships. We demonstrate that calcite-containing rock grains under EM tree species weather significantly faster than those under AM trees, an effect linked to greater soil acidification by EM trees. Weathering and corresponding alkalinity export are likely to increase with rising atmospheric CO2 and associated climate change. Our analyses suggest that strategic planting of fast-growing EM angiosperm taxa on calcite- and dolomite-rich terrain might accelerate the transient sink for atmospheric CO2 and slow rates of ocean acidification. PMID:25211602

  5. Paleogene plants fractionated carbon isotopes similar to modern plants

    Science.gov (United States)

    Diefendorf, Aaron F.; Freeman, Katherine H.; Wing, Scott L.; Currano, Ellen D.; Mueller, Kevin E.

    2015-11-01

    The carbon isotope composition (δ13 C) of terrestrial plant biomarkers, such as leaf waxes and terpenoids, provides insights into past carbon cycling. The δ13 C values of modern plant biomarkers are known to be sensitive to climate and vegetation type, both of which influence fractionation during lipid biosynthesis by altering plant carbon supply and its biochemical allocation. It is not known if fractionation observed in living plants can be used to interpret fossil lipids because plant biochemical characteristics may have evolved during the Cenozoic in response to changes in global climate and atmospheric CO2. The goal of this study was to determine if fractionation during photosynthesis (Δleaf) in the Paleogene was consistent with expectations based on living plants. To study plant fractionation during the Paleogene, we collected samples from eight stratigraphic beds in the Bighorn Basin (Wyoming, USA) that ranged in age from 63 to 53 Ma. For each sample, we measured the δ13 C of angiosperm biomarkers (triterpenoids and n-alkanes) and, abundance permitting, conifer biomarkers (diterpenoids). Leaf δ13 C values estimated from different angiosperms biomarkers were consistently 2‰ lower than leaf δ13 C values for conifers calculated from diterpenoids. This difference is consistent with observations of living conifers and angiosperms and the consistency among different biomarkers suggests ancient εlipid values were similar to those in living plants. From these biomarker-based δ13Cleaf values and independent records of atmospheric δ13 C values, we calculated Δleaf. These calculated Δleaf values were then compared to Δleaf values modeled by applying the effects that precipitation and major taxonomic group in living plants have on Δleaf values. Calculated and modeled Δleaf values were offset by less than a permil. This similarity suggests that carbon fractionation in Paleogene plants changed with water availability and major taxonomic group to about the

  6. The cinnamyl alcohol dehydrogenase gene family in Populus: phylogeny, organization, and expression

    Directory of Open Access Journals (Sweden)

    Yellanki Priyadarshini

    2009-03-01

    Full Text Available Abstract Background Lignin is a phenolic heteropolymer in secondary cell walls that plays a major role in the development of plants and their defense against pathogens. The biosynthesis of monolignols, which represent the main component of lignin involves many enzymes. The cinnamyl alcohol dehydrogenase (CAD is a key enzyme in lignin biosynthesis as it catalyzes the final step in the synthesis of monolignols. The CAD gene family has been studied in Arabidopsis thaliana, Oryza sativa and partially in Populus. This is the first comprehensive study on the CAD gene family in woody plants including genome organization, gene structure, phylogeny across land plant lineages, and expression profiling in Populus. Results The phylogenetic analyses showed that CAD genes fall into three main classes (clades, one of which is represented by CAD sequences from gymnosperms and angiosperms. The other two clades are represented by sequences only from angiosperms. All Populus CAD genes, except PoptrCAD 4 are distributed in Class II and Class III. CAD genes associated with xylem development (PoptrCAD 4 and PoptrCAD 10 belong to Class I and Class II. Most of the CAD genes are physically distributed on duplicated blocks and are still in conserved locations on the homeologous duplicated blocks. Promoter analysis of CAD genes revealed several motifs involved in gene expression modulation under various biological and physiological processes. The CAD genes showed different expression patterns in poplar with only two genes preferentially expressed in xylem tissues during lignin biosynthesis. Conclusion The phylogeny of CAD genes suggests that the radiation of this gene family may have occurred in the early ancestry of angiosperms. Gene distribution on the chromosomes of Populus showed that both large scale and tandem duplications contributed significantly to the CAD gene family expansion. The duplication of several CAD genes seems to be associated with a genome duplication

  7. Multistate characters and diet shifts: evolution of Erotylidae (Coleoptera).

    Science.gov (United States)

    Leschen, Richard A B; Buckley, Thomas R

    2007-02-01

    The dominance of angiosperms has played a direct role in the diversification of insects, especially Coleoptera. The shift to angiosperm feeding from other diets is likely to have increased the rate of speciation in Phytophaga. However, Phytophaga is only one of many hyperdiverse lineages of beetles and studies of host-shift proliferation have been somewhat limited to groups that primitively feed on plants. We have studied the diet-diverse beetle family Erotylidae (Cucujoidea) to determine if diet is correlated with high diversification rates and morphological evolution by first reconstructing ancestral diets and then testing for associations between diet and species number and diet and ovipositor type. A Bayesian phylogenetic analysis of morphological data that was previously published in Leschen (2003, Pages 1-108 in Fauna of New Zealand, 47; 53 terminal taxa and 1 outgroup, 120 adult characters and 1 diet character) yielded results that are similar to the parsimony analyses of Leschen (2003). Ancestral state reconstructions based on Bayesian and parsimony inference were largely congruent and both reconstructed microfungal feeding (the diet of the outgroup Biphyllidae) at the root of the Erotylidae tree. Shifts among microfungal, saprophagous, and phytophagous diets were most frequent. The largest numbers of species are contained in lineages that are macrofungal feeders (subfamily Erotylinae) and phytophagous (derived Languriinae), although the Bayesian posterior predictive tests of character state correlation were unable to detect any significant associations. Ovipositor morphology correlated with diet (i.e., acute forms were associated with phytophagy and unspecialized forms were associated with a mixture of diets). Although there is a general trend to increased species number associated with the shift from microfungal feeding to phytophagy (based on character mapping and mainly restricted to shifts in Languriinae), there is a large radiation of taxa feeding on

  8. Magnitude of the carbon isotope excursion at the Paleocene Eocene thermal maximum: The role of plant community change

    Science.gov (United States)

    Smith, Francesca A.; Wing, Scott L.; Freeman, Katherine H.

    2007-10-01

    Carbon-isotope measurements ( δ13C) of leaf-wax n-alkanes from the Paleocene-Eocene Thermal Maximum (PETM) in the Bighorn Basin, Wyoming, reveal a negative carbon isotope excursion (CIE) of 4-5‰, which is 1-2‰ larger than that observed in marine carbonate δ13C records. Reconciling these records requires either that marine carbonates fail to record the full magnitude of the CIE or that the CIE in plants has been amplified relative to the marine. Amplification of the CIE has been proposed to result from an increase in available moisture that allowed terrestrial plants to increase 13C-discrimination during the PETM. Leaf physiognomy, paleopedology and hydrogen isotope ratios of leaf-wax lipids from the Bighorn Basin, however, all suggest that rather than a simple increase in available moisture, climate alternated between wet and dry during the PETM. Here we consider two other explanations and test them quantitatively with the carbon isotopic record of plant lipids. The "marine modification" hypothesis is that the marine carbonate record was modified by chemical changes at the PETM and that plant lipids record the true magnitude of the CIE. Using atmospheric CO 2δ13C values estimated from the lipid record, and equilibrium fractionation between CO 2 and carbonate, we estimate the expected CIE for planktonic foraminifera to be 6‰. Instead, the largest excursion observed is about 4‰. No mechanism for altering marine carbonate by 2‰ has been identified and we thus reject this explanation. The "plant community change" hypothesis is that major changes in floral composition during the PETM amplified the CIE observed in n-alkanes by 1-2‰ relative to marine carbonate. This effect could have been caused by a rapid transition from a mixed angiosperm/conifer flora to a purely angiosperm flora. The plant community change hypothesis is consistent with both the magnitude and pattern of CIE amplification among the different n-alkanes, and with data from fossil plants

  9. Accumulation of transuranic elements in the aquatic biota of the Belarusian sector of contaminated area near the Chernobyl nuclear power plant - Accumulation of transuranic elements in aquatic biota of Belarusian sector of contaminated area of Chernobyl nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Golubev, Alexander; Mironov, Vladislav [International Sakharov Environmental University. Box 220070, 23 Dolgobrodskaya Street, Minsk, 220070 (Belarus)

    2014-07-01

    The evolution of nuclear contamination of Belarus territory after Chernobyl accident includes the four stages: 1. Iodine-neptunium stage, caused mainly by short-lived radionuclides {sup 131}I, {sup 239}Np and others with a half-life period of several weeks; II. Intermediate stage, caused by radionuclides with a half-life period of a year ({sup 144}Ce, {sup 106}Ru, {sup 134}Cs, etc.); III. Strontium-cesium stage, caused by {sup 90}Sr and {sup 137}Cs with a half-life period of about 30 years; IV. Plutonium-americium, caused by long-lived α-emitting radionuclides {sup 241}Am (period of half-life of 432 years) and {sup 239+240}Pu, having high radio and chemo-toxicity. According to forecasts, activity of {sup 241}Am to 2050 year will increase by 2.5 times and it will be the most important dose-related factor for the aquatic biota within the Chernobyl accident zone. In 2002 - 2008 years we have studied the accumulation of trans-uranic elements (TUE, {sup 241}Am, {sup 239+240}Pu) in basic components of water body ecosystems within the Chernobyl zone - non-flowing Perstok Lake, weak-flowing Borschevka flooding and small Braginka River. Among investigated components are water, bottom sediments, submerged macrophytes (Ceratophyllum submersum, Hydrocharis morsus-ranae, Lemna minor, Nuphar lutea, Stratiotes aloides), emergent macrophytes (Typha spp.), shellfish and fish. In the soil cover in the vicinity of the Perstok Lake activity of {sup 241}Am at present is equivalent to 300 - 600 Bq.kg{sup -1}, that is the basic source of its income to the lake. Radionuclides mobility in the water environment is higher than in the soil, that facilitates the rapid incorporation of {sup 241}Am to the trophic nets of water bodies and its removal by near-water animals in the terrestrial biotopes, including outside Chernobyl zone. Thus, the activity of {sup 241}Am in bottom sediments in the Perstok Lake and Borschevka flooding in 2008 year reach respectively 324 and 131 Bq.kg{sup -1}, and the

  10. Accumulation of transuranic elements in the aquatic biota of the Belarusian sector of contaminated area near the Chernobyl nuclear power plant - Accumulation of transuranic elements in aquatic biota of Belarusian sector of contaminated area of Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    The evolution of nuclear contamination of Belarus territory after Chernobyl accident includes the four stages: 1. Iodine-neptunium stage, caused mainly by short-lived radionuclides 131I, 239Np and others with a half-life period of several weeks; II. Intermediate stage, caused by radionuclides with a half-life period of a year (144Ce, 106Ru, 134Cs, etc.); III. Strontium-cesium stage, caused by 90Sr and 137Cs with a half-life period of about 30 years; IV. Plutonium-americium, caused by long-lived α-emitting radionuclides 241Am (period of half-life of 432 years) and 239+240Pu, having high radio and chemo-toxicity. According to forecasts, activity of 241Am to 2050 year will increase by 2.5 times and it will be the most important dose-related factor for the aquatic biota within the Chernobyl accident zone. In 2002 - 2008 years we have studied the accumulation of trans-uranic elements (TUE, 241Am, 239+240Pu) in basic components of water body ecosystems within the Chernobyl zone - non-flowing Perstok Lake, weak-flowing Borschevka flooding and small Braginka River. Among investigated components are water, bottom sediments, submerged macrophytes (Ceratophyllum submersum, Hydrocharis morsus-ranae, Lemna minor, Nuphar lutea, Stratiotes aloides), emergent macrophytes (Typha spp.), shellfish and fish. In the soil cover in the vicinity of the Perstok Lake activity of 241Am at present is equivalent to 300 - 600 Bq.kg-1, that is the basic source of its income to the lake. Radionuclides mobility in the water environment is higher than in the soil, that facilitates the rapid incorporation of 241Am to the trophic nets of water bodies and its removal by near-water animals in the terrestrial biotopes, including outside Chernobyl zone. Thus, the activity of 241Am in bottom sediments in the Perstok Lake and Borschevka flooding in 2008 year reach respectively 324 and 131 Bq.kg-1, and the activity of 241Am in macrophytes of the Perstok Lake at the same year was 1,0 - 3,7 Bq.kg-1. In

  11. Foraminiferal biostratigraphy of lignite mines of Kutch,India:Age of lignite and fossil vertebrates

    Institute of Scientific and Technical Information of China (English)

    Pratul; Kumar; Saraswati; Sonal; Khanolkar; Dalta; Surya; Narayana; Raju; Suryendu; Dutta; Santanu; Banerjee

    2014-01-01

    The lignite deposits of Kutch, India are stratigraphically referred to the Naredi Formation and considered to be Early Eocene in age. The biostratigraphy of the older mine at Panandhro and a newly opened mine at Matanomadh has constrained the upper age limit of lignite to the early Bartonian. Its lower age may extend to the late Lutetian. Temporally the formation of lignite corresponds to the warming event of the Middle Eocene and suggests a humid climate at the onset of the warming. The previous palynological studies have already suggested dominance of tropical angiospermic pollen. A diverse assemblage of fossil whales and other vertebrates, many of them supposedly the oldest representatives, were reported from Panandhro mine. These were initially assigned to the Early Eocene and later to the Lute? tian age. The present biostratigraphic study revises their age to the Early Bartonian.

  12. Molecular indicators for coal-forming vegetation of the Miocene Chukurovo lignite, Bulgaria

    Energy Technology Data Exchange (ETDEWEB)

    Maya Stefanova; Kalinka Markova; Stefan Marinov; Bernd R.T. Simoneit [Bulgarian Academy of Sciences, Sofia (Bulgaria). Institute of Organic Chemistry

    2005-10-01

    The main coal forming element in the peat paleoswamp of the Middle Miocene 'Chukurovo' lignite is Taxodiaceae (paleobotanical observation). The great preponderance of diterpenoids in the resinite is a chemical confirmation for the presence of coniferous vegetation in the paleoplant taxa. Subordinate quantities of the sesquiterpenoids cuparene, valencene and cadalene types and longifolane are present. Molecular indicators for angiosperm vegetation are also recognized in the bulk coal. The presence of olean-12-ene, urs-12-ene, 24,25-dinoroleana-1,3,5(10)12-tetraene, and 24,25-dinorursa-1,3,5(10)12-tetraene all indicate flowering trees and provide the possibility to further assess the paleoplant community. The triterpenoid data indicate oxic diagenetic transformation of plant detritus had been proceeded by aromatization of ring A-E. 33 refs., 5 figs., 3 tabs., 1 append.

  13. Paleogeography and paleoecology of the upper Miocene Zillingdorf lignite deposit (Austria)

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel, A.; Reischenbacher, D.; Sachsenhofer, R.F.; Gratzer, R. [Department Angewandte Geowissenschaften und Geophysik, Montanuniversitaet Leoben, Peter-Tunner-Str. 5, A-8700 Leoben (Austria); Luecke, A. [Institut fuer Chemie und Dynamik der Geosphaere V: Sedimentaere Systeme (ICG V), Forschungszentrum Juelich, D-52425 Juelich (Germany)

    2007-02-01

    The Zillingdorf deposit formed during the late Miocene filling of Lake Pannon and contains Austria's largest lignite reserves. Two lignite seams are present and developed within frequently flooded, low-lying mires in near shore environments. High sulphur contents are due to the influence of the brackish water body of Lake Pannon. During peat accumulation a transgression forced the NW-SE trending shoreline northeastwards. Differences in soluble organic matter (SOM) yield and hydrocarbon content of borehole samples and woody macrofossils are related to differences in the content and composition of free lipids of microbial origin and/or hydrocarbons derived from the biogeochemical degradation of plant tissue. Variations of pristane/phytane ratios are interpreted to reflect differences in the redox conditions of the mire. Peatification in an acidic and aerobic environment is further reflected by the predominance of aromatic over saturated hydrocarbons, the presence of an intense complex mixture in the GC traces due to biodegradation processes, high ratios for diasterenes relative to sterenes, and high concentration ratios of hopanes to hop-17(21)-ene of the respective samples. Gelification of plant tissue is governed by microbial activity, as indicated by the positive relationship between gelification index and hopanoids concentration. The composition of terpenoid biomarkers indicates the predominance of gymnosperms over angiosperms and increasing proportions of angiosperms in the peat-forming vegetation with decreasing depth in the upper seam. From the sesqui- and diterpenoids present in the lignite and fossil wood remnants, a predominant role of species of the Coniferales families Cupressaceae/Taxodiaceae are concluded. The preservation of plant tissue is governed by the presence/absence of decay-resistant gymnosperms. A general influence of the floral assemblage on the isotopic composition of organic carbon of the lignite ({delta}{sup 13}C=-27.2 to -24.6%%) is

  14. Floristic diversity and survival strategies of climbers in a Caatinga fragment in the municipality of Porto da Folha, Sergipe, Brazil

    Directory of Open Access Journals (Sweden)

    Diogo Gallo de Oliveira

    2015-05-01

    Full Text Available A floristic survey of climbing species in a Caatinga fragment in the municipality of Porto da Folha, state of Sergipe, Northeast Brazil, was conducted to determine their survival strategies during unfavorable seasons. Forty-five angiosperm species belonging to 29 genera and 14 families were counted. Species richness was higher than that recorded in other Caatinga areas. The most representative families were Convolvulaceae (8, Fabaceae (6, Apocynaceae (5, and Dioscoreaceae (5. Most of the climbers (64.4% were herbaceous. Therophytes represented the dominant lifestyle (51.1% and represented the main dry-season escape strategy. Climbers are important biological groups that require more studies on their autoecological aspects and their role in ecological communities and should be considered in the establishment of biodiversity conservation strategies.

  15. Functional Diversity of Plant-Pollinator Interaction Webs Enhances the Persistence of Plant Communities.

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available Pollination is exclusively or mainly animal mediated for 70% to 90% of angiosperm species. Thus, pollinators provide an essential ecosystem service to humankind. However, the impact of human-induced biodiversity loss on the functioning of plant-pollinator interactions has not been tested experimentally. To understand how plant communities respond to diversity changes in their pollinating fauna, we manipulated the functional diversity of both plants and pollinators under natural conditions. Increasing the functional diversity of both plants and pollinators led to the recruitment of more diverse plant communities. After two years the plant communities pollinated by the most functionally diverse pollinator assemblage contained about 50% more plant species than did plant communities pollinated by less-diverse pollinator assemblages. Moreover, the positive effect of functional diversity was explained by a complementarity between functional groups of pollinators and plants. Thus, the functional diversity of pollination networks may be critical to ecosystem sustainability.

  16. Floral evolution: Beyond traditional viewpoint of pollinator mediated floral design

    Institute of Scientific and Technical Information of China (English)

    YANG Chunfeng; GUO Youhao

    2005-01-01

    Pollination biology provides new insight for understanding the evolutionary mechanism and process of the existing diversity in floral design of angiosperms. Evolutionary biologists have established some rules and models to try to explain the ubiquitous relationship between pollination system and floral evolution. However, as new techniques have been applied and more and more new pollination events found in recent years, the relationship between pollination system and floral evolution has become less clear. Researchers realized that floral evolution is more complicated and idiosyncratic than simple adaptive models. The traditional viewpoints of pollinator mediated floral design urgently need new reevaluation. This paper attempts to make a brief review of such main opinions and introduce their new insights according to recent studies. Finally, we also give some suggestions for future study by reviewing several new viewpoints about floral evolution.

  17. MYB-FL controls gain and loss of floral UV absorbance, a key trait affecting pollinator preference and reproductive isolation.

    Science.gov (United States)

    Sheehan, Hester; Moser, Michel; Klahre, Ulrich; Esfeld, Korinna; Dell'Olivo, Alexandre; Mandel, Therese; Metzger, Sabine; Vandenbussche, Michiel; Freitas, Loreta; Kuhlemeier, Cris

    2016-02-01

    Adaptations to new pollinators involve multiple floral traits, each requiring coordinated changes in multiple genes. Despite this genetic complexity, shifts in pollination syndromes have happened frequently during angiosperm evolution. Here we study the genetic basis of floral UV absorbance, a key trait for attracting nocturnal pollinators. In Petunia, mutations in a single gene, MYB-FL, explain two transitions in UV absorbance. A gain of UV absorbance in the transition from bee to moth pollination was determined by a cis-regulatory mutation, whereas a frameshift mutation caused subsequent loss of UV absorbance during the transition from moth to hummingbird pollination. The functional differences in MYB-FL provide insight into the process of speciation and clarify phylogenetic relationships between nascent species. PMID:26656847

  18. Charcoal anatomy of forest species

    Directory of Open Access Journals (Sweden)

    Graciela Inés Bolzon de Muñiz1

    2012-09-01

    Full Text Available Vegetal charcoal retains the anatomical structure of the wood and may permit its botanical identification, which depends on species characteristics, the charcoal fragments size and preservation state. Anatomical characterization of ten forest species charcoal was done envisaging the identification and control of illegal charcoal. Differences between gymnosperms and angiosperms are evident in carbonized wood. Vessel diameter was statistically different between wood and charcoal in Vatairea guianensis, Mezilaurus itauba, Calophyllum brasiliense e Qualea cf. acuminata, and vessel frequency in Vatairea guianensis, Manilkara huberi, Qualea cf. acuminata e Simarouba amara. The anatomical structure from wood, in general aspects, is constant during carbonization process using temperature of 450°C, being possible to identify the material by using its cellular components.

  19. Why Assembling Plant Genome Sequences Is So Challenging

    Directory of Open Access Journals (Sweden)

    Pedro Seoane

    2012-09-01

    Full Text Available In spite of the biological and economic importance of plants, relatively few plant species have been sequenced. Only the genome sequence of plants with relatively small genomes, most of them angiosperms, in particular eudicots, has been determined. The arrival of next-generation sequencing technologies has allowed the rapid and efficient development of new genomic resources for non-model or orphan plant species. But the sequencing pace of plants is far from that of animals and microorganisms. This review focuses on the typical challenges of plant genomes that can explain why plant genomics is less developed than animal genomics. Explanations about the impact of some confounding factors emerging from the nature of plant genomes are given. As a result of these challenges and confounding factors, the correct assembly and annotation of plant genomes is hindered, genome drafts are produced, and advances in plant genomics are delayed.

  20. Palynology of Lower Palaeogene (Thanetian-Ypresian) coastal deposits from the Barmer Basin (Akli Formation, Western Rajasthan, India): palaeoenvironmental and palaeoclimatic implications

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, S.K.M.; Kumar, M.; Srivastava, D. [Birbal Sahni Instititue of Paleobotany, Lucknow (India)

    2009-03-15

    The 32-m thick sedimentary succession of the Paleocene-Eocene Akli Formation (Barmer basin, Rajasthan, India), which is exposed in an open-cast lignite mine, interbed several lignite seams that alternate with fossiliferous carbonaceous clays, green clays and widespread siderite bands and chert nodules. The palynofloral assemblages consist of spore, pollen and marine dinoflagellate cysts that indicate a Thanetian to Ypresian age. The assemblage is dominated by angiospermic pollen and specimens showing affinity with the mangrove Palm Nypa are also very abundant. The Nypa-like pollen specimens exhibit a wide range of morphological variation, some of the recorded morphotypes being restricted to this Indian basin. Preponderance of these pollen taxa indicates that the sediments were deposited in a coastal swamp surrounded by thick, Nypa-dominated mangrove vegetation. The dispersed organic matter separated from macerated residues indicates the dominance of anoxic conditions throughout the succession, although a gradual transition to oxic conditions is recorded in the upper part.

  1. Pollen analysis of coal-bearing Miocene sedimentary rocks from the Seyitomer basin (Kutahya), western Anatolia

    Energy Technology Data Exchange (ETDEWEB)

    Yavuz-Isik, N. [Ondokuz Mayis University, Kurupelit (Turkey). Dept. of Civil Engineering

    2007-09-15

    The late Early-Middle Miocene sequences of the Seyitomer Basin (western Anatolia) were palynologically investigated. Fifty-five taxa belonging to seven gymnospermous and 48 angiospermous pollen genera were identified in the 19 productive samples. Two pollen zones were recognised based on the changing abundance of individual tree taxa. Zone 1 is characterized by predominance of Pinus and Cedrus. Zone 2 is characterized by predominance of deciduous Quercus and evergreen Quercus and a marked reduction in representation of Taxodiaceae. The differences in the pollen spectra between Zone 1 and Zone 2 may reflect the global Middle Miocene cooling. These results are largely comparable to pollen data derived from the neighbouring areas. The vegetation of the Seyitomer Basin was dominated by trees. This palynological analysis reveals the existence of a swamp-forest developed in a subtropical to warm-temperate humid climate.

  2. 福建植物新资料(一)%New Materials of Plants in Fujian Province (Ⅰ)

    Institute of Scientific and Technical Information of China (English)

    姜秋怡; 侯学良; 王文卿; 张宜辉

    2013-01-01

      在泉州湾植物调查时,发现福建省被子植物分布新记录5种(含变种),分别是:盐地碱蓬Suaeda salsa、座地猪屎豆Crotalaria nana var. patula、沙地叶下珠Phyllanthus arenarius、肉叶耳草Hedyotis strigulosa和佛欧里画眉草Eragrostis fauriei。标本存放于厦门大学植物标本馆(AU)。%  During the course of investigating the plants in Quanzhou bay, four newly recorded species and one newly recorded varieties of Angiosperm were found. They are Suaeda salsa, Crotalaria nana var. patula, Phyllanthus arenarius, Hedyotis strigulosa and Eragrostis fauriei. The voucher specimens are deposited in the Herbarium of Xiamen University (AU).

  3. Re-assessing the role of plant community change and climate in the PETM n-alkane record

    Science.gov (United States)

    Bush, R. T.; Baczynski, A. A.; McInerney, F. A.; Chen, D.

    2012-12-01

    The terrestrial leaf wax n-alkane record of the Paleocene-Eocene Thermal Maximum (PETM) in the Bighorn Basin, Wyoming, shows large excursions in both carbon isotope (δ13C) values and n-alkane average chain length (ACL). At the onset of the PETM, ACL values increase from ~28.5 to ~30.1 while the negative carbon isotope excursion (CIE) is 4-6‰ in magnitude and larger than δ13C records from other materials. It has been hypothesized previously that both the ACL excursion and the large magnitude of the CIE were caused by a concurrent turnover in the local flora from a mixed conifer/angiosperm community before the PETM to a different suite of angiosperm species during the PETM. Here, we present the results of a meta-analysis of data (>2000 data from 89 sources, both published and unpublished) on n-alkane amounts and chain length distributions in modern plants from around the world. We applied the data in two sets of comparisons: 1) within and among plant groups such as herbs and graminoids, and 2) between plants and climate, using reported collection locations for outdoor plants and climate values generated via GIS extraction of WorldClim modeled data. We show that angiosperms, as group, produce more n-alkanes than do gymnosperms by 1-2 orders of magnitude, and this means that the gymnosperm contribution to a mixed soil n-alkane pool would be negligible, even in an ecosystem where gymnosperms dominated (i.e. the pre/post-PETM ecosystems). The modern plant data also demonstrate that turnover of the plant community during the PETM, even among only the angiosperm species, is likely not the source of the observed ACL excursion. First, we constructed "representative" groups of PETM and pre/post-PETM communities using living relative species at the Chicago Botanic Garden and find no significant difference in chain length distributions between the two groups. Second and moreover, the modern plant data reveal that n-alkane chain length distributions are tremendously variable

  4. Lunar Influence On Plants

    Science.gov (United States)

    Schad, Wolfgang

    Concerning lunar periodicity in biology, we summarized all what has been observationally and experimentally found and published in scientific literature till 1996. We summoned up as many as about 600 living species (mostly animals) with identified lunar periodicities, functioning in a more or less endogenous manner. Here we give a short review about the occurrence in the plant kingdom. In Thallophytes 45 species have been described as well as 40 species of Angiosperms. In Prokaryonts no lunar rhythms could be found. Their individual life cycles do not reach the time span of at least comparable parts of a lunar day. Thus as in all Eukaryonts the occurrence of the cell nucleus constitutes specifically ndogenous rhythms in plants as well as in the animal kingdom.

  5. Bombacaceae endémicas del Perú

    Directory of Open Access Journals (Sweden)

    Blanca León

    2013-10-01

    Full Text Available En este trabajo, la familia Bombacaceae es considerada aparte de las Malvaceae, con la cual se considera forma un grupo natural (ver Judd et al. 1997 y la página de internet de Angiosperm Phylogeny Group. En el Perú, las Bombacaceae incluyen 15 géneros y 56 especies (Brako & Zarucchi, 1993; Ulloa Ulloa et al., 2004, generalmente árboles. Siete especies en cinco géneros son endemismos del país. Estas especies endémicas ocupan principalmente las regiones Bosques Secos y Bosques Húmedos Amazónicos, entre los 1300 y 3000 m de altitud. Se aplicaron las categorías y criterios de la UICN a cuatro especies. Ninguna de las Bombacaceae endémicas está representada en el Sistema Nacional de Áreas Naturales Protegidas por el Estado.

  6. Changes in nuclear, nucleolar and cytoplasmic RNA content during growth and differentiation of root parenchyma cells in plant species with different dynamics of DNA endoreplication.

    Science.gov (United States)

    Marciniak, K; Bilecka, A

    1985-01-01

    Using cytophotometric method, after staining preparations with gallocyanin RNA content was examined in nucleus, nucleolus and cytoplasm of six species of angiospermal plants in successive (1-7 mm) segments of root representing successive zones of differentiation. During the cell cycle, RNA content duplicates in the nucleus, nucleolus and cytoplasm of meristematic cells. On the other hand, during growth and differentiation of parenchyma cells in species with endoreplication the content of nucleolar RNA does not increase in proportion with DNA content. High level of endoreplication is connected with high nucleolar RNA content and low cytoplasmic RNA content. In species without endoreplication at low nucleolar RNA content, a considerable growth of cytoplasmic RNA content takes place. PMID:2417894

  7. Nopal cactus (Opuntia ficus-indica) as a source of bioactive compounds for nutrition, health and disease.

    Science.gov (United States)

    El-Mostafa, Karym; El Kharrassi, Youssef; Badreddine, Asmaa; Andreoletti, Pierre; Vamecq, Joseph; El Kebbaj, M'Hammed Saïd; Latruffe, Norbert; Lizard, Gérard; Nasser, Boubker; Cherkaoui-Malki, Mustapha

    2014-01-01

    Opuntia ficus-indica, commonly referred to as prickly pear or nopal cactus, is a dicotyledonous angiosperm plant. It belongs to the Cactaceae family and is characterized by its remarkable adaptation to arid and semi-arid climates in tropical and subtropical regions of the globe. In the last decade, compelling evidence for the nutritional and health benefit potential of this cactus has been provided by academic scientists and private companies. Notably, its rich composition in polyphenols, vitamins, polyunsaturated fatty acids and amino acids has been highlighted through the use of a large panel of extraction methods. The identified natural cactus compounds and derivatives were shown to be endowed with biologically relevant activities including anti-inflammatory, antioxidant, hypoglycemic, antimicrobial and neuroprotective properties. The present review is aimed at stressing the major classes of cactus components and their medical interest through emphasis on some of their biological effects, particularly those having the most promising expected health benefit and therapeutic impacts. PMID:25232708

  8. Nopal Cactus (Opuntia ficus-indica as a Source of Bioactive Compounds for Nutrition, Health and Disease

    Directory of Open Access Journals (Sweden)

    Karym El-Mostafa

    2014-09-01

    Full Text Available Opuntia ficus-indica, commonly referred to as prickly pear or nopal cactus, is a dicotyledonous angiosperm plant. It belongs to the Cactaceae family and is characterized by its remarkable adaptation to arid and semi-arid climates in tropical and subtropical regions of the globe. In the last decade, compelling evidence for the nutritional and health benefit potential of this cactus has been provided by academic scientists and private companies. Notably, its rich composition in polyphenols, vitamins, polyunsaturated fatty acids and amino acids has been highlighted through the use of a large panel of extraction methods. The identified natural cactus compounds and derivatives were shown to be endowed with biologically relevant activities including anti-inflammatory, antioxidant, hypoglycemic, antimicrobial and neuroprotective properties. The present review is aimed at stressing the major classes of cactus components and their medical interest through emphasis on some of their biological effects, particularly those having the most promising expected health benefit and therapeutic impacts.

  9. A Tale of Two Hyper-diversities: Diversification dynamics of the two largest families of lichenized fungi.

    Science.gov (United States)

    Kraichak, Ekaphan; Divakar, Pradeep K; Crespo, Ana; Leavitt, Steven D; Nelsen, Matthew P; Lücking, Robert; Lumbsch, H Thorsten

    2015-01-01

    Renewed interests in macroevolutionary dynamics have led to the proliferation of studies on diversification processes in large taxonomic groups, such as angiosperms, mammals, and birds. However, such a study has yet to be conducted in lichenized fungi--an extremely successful and diverse group of fungi. Analysing the most comprehensive time-calibrated phylogenies with a new analytical method, we illustrated drastically different diversification dynamics between two hyper-diverse families of lichenized fungi, Graphidaceae and Parmeliaceae, which represent more than a fourth of the total species diversity of lichenized fungi. Despite adopting a similar nutrition mode and having a similar number of species, Graphidaceae exhibited a lower speciation rate, while Parmeliaceae showed a sharp increase in speciation rate that corresponded with the aridification during the Oligocene-Miocene transition, suggesting their adaptive radiation into a novel arid habitat. PMID:25944223

  10. Re-evaluation of the age of the Brandon Lignite (Vermont, USA) based on plant megafossils. [USA - Vermont

    Energy Technology Data Exchange (ETDEWEB)

    Tiffney, B.H. (University of California at Santa Barbara, Santa Barbara, CA (United States). Dept. of Geological Sciences)

    1994-07-01

    The Brandon Lignite of west-central Vermont contains the northernmost megafossil flora of Cenozoic angiosperms, and one of the most diverse Cenozoic pollen floras in northeastern North America. While the floristic composition clearly indicates deposition of the Brandon sediments in the warmer parts of the Cenozoic, previous attempts at a more precise stratigraphic placement have been inconclusive, ranging from Cretaceous to Miocene. Re-evaluation of existing and new fruit, seed and wood data from the Brandon flora in the context of other floras in the Northern Hemisphere leads to the conservative conclusion that the deposit could range from earliest Oligocene to Early Miocene. Several lines of potentially weak evidence favor an Early Miocene age, in agreement with recent biostratigraphic data from the associated pollen flora. It is concluded that the Brandon Lignite is Early Miocene.

  11. The effects of plant traits and phylogeny on soil-to-plant transfer of {sup 99}Tc

    Energy Technology Data Exchange (ETDEWEB)

    Willey, N.J., E-mail: Neil.Willey@uwe.ac.u [Centre for Research in Plant Science, University of the West of England, Coldharbour Lane, Frenchay, Bristol, BS16 1QY (United Kingdom); Tang, S. [Agro-Environmental Protection Institute of the Ministry of Agriculture, No. 31 Fukang Road, Nankai District, Tianjing City 300191 (China); McEwen, A.; Hicks, S. [Centre for Research in Plant Science, University of the West of England, Coldharbour Lane, Frenchay, Bristol, BS16 1QY (United Kingdom)

    2010-09-15

    Assessments of the behaviour of {sup 99}Tc in terrestrial environments necessitate predicting soil-to-plant transfer. An experiment with 116 plant taxa showed that {sup 99}Tc transfer to plants was positively related to plant dry weight but negatively related to % dry matter and age at exposure. Activities of {sup 99}Tc analysed by hierarchical ANOVA coded with an angiosperm phylogeny revealed significant effects, with 55% of the variance between species explained at the Ordinal level and above. Monocots had significantly lower transfer of {sup 99}Tc than Eudicots, within which Caryophyllales > Solanales > Malvales > Brassicales > Asterales > Fabales. There was a significant phylogenetic signal in soil-to-plant transfer of {sup 99}Tc. This phylogenetic signal is used to suggest that, for example, a nominal Tc Transfer Factor of 5 could be adjusted to 2.3 for Monocots and 5.3 for Eudicots.

  12. Primary Cell Wall Structure in the Evolution of Land Plants

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Investigation of the primary cell walls of lower plants improves our understanding of the cell biology of these organisms but also has the potential to improve our understanding of cell wall structure and function in angiosperms that evolved from lower plants. Cell walls were prepared from eight species, ranging from a moss to advanced gymnosperms, and subjected to sequential chemical extraction to separate the main polysaccharide fractions. The glycosyl compositions of these fractions were then determined by gas chromatography. The results were compared among the eight plants and among data from related studies reported in the existing published reports to identify structural features that have been either highly conserved or clearly modified during evolution. Among the highly conserved features are the presence of a cellulose framework, the presence of certain hemicelluloses such as xyloglucan, and the presence of rhamnogalacturonan Ⅱ, a domain in pectic polysaccharides. Among the modified features are the abundance of mannosyl-containing hemicelluloses and the presence of methylated sugars.

  13. Evolution of tree nutrition.

    Science.gov (United States)

    Raven, John A; Andrews, Mitchell

    2010-09-01

    Using a broad definition of trees, the evolutionary origins of trees in a nutritional context is considered using data from the fossil record and molecular phylogeny. Trees are first known from the Late Devonian about 380 million years ago, originated polyphyletically at the pteridophyte grade of organization; the earliest gymnosperms were trees, and trees are polyphyletic in the angiosperms. Nutrient transporters, assimilatory pathways, homoiohydry (cuticle, intercellular gas spaces, stomata, endohydric water transport systems including xylem and phloem-like tissue) and arbuscular mycorrhizas preceded the origin of trees. Nutritional innovations that began uniquely in trees were the seed habit and, certainly (but not necessarily uniquely) in trees, ectomycorrhizas, cyanobacterial, actinorhizal and rhizobial (Parasponia, some legumes) diazotrophic symbioses and cluster roots. PMID:20581011

  14. A Collection of the Dendrological Garden in Glinna (Northwest Poland

    Directory of Open Access Journals (Sweden)

    Marcin KUBUS

    2008-08-01

    Full Text Available The small dendrological garden in Glinna (about 6 ha near Szczecin (northwest Poland is one of the 16 scientific places in Poland, which is well-known for growing a lot of unique trees. The local mild microclimate in combination with the Atlantic climate of West Pomerania produce favourable conditions for growing many varieties of trees and shrubs which undergo freezing in central and eastern Poland. The garden's collection amounts up to 632 taxons of trees and shrubs, representatives of 199 genera. What is valuable in the collection of the arboretum is that the cultural varieties among the gymnospermous plants make only 25%, whereas among the angiospermous plants - 10%. The mammoth tree remains the garden's symbol and its speciality consists in species of Chinese origin (180 taxons and maples (68 taxons.

  15. Functional genomic analysis supports conservation of function among cellulose synthase-like a gene family members and suggests diverse roles of mannans in plants

    DEFF Research Database (Denmark)

    Liepman, Aaron H; Nairn, C Joseph; Willats, William G T;

    2007-01-01

    Mannan polysaccharides are widespread among plants, where they serve as structural elements in cell walls, as carbohydrate reserves, and potentially perform other important functions. Previous work has demonstrated that members of the cellulose synthase-like A (CslA) family of glycosyltransferases...... from Arabidopsis (Arabidopsis thaliana), guar (Cyamopsis tetragonolobus), and Populus trichocarpa catalyze beta-1,4-mannan and glucomannan synthase reactions in vitro. Mannan polysaccharides and homologs of CslA genes appear to be present in all lineages of land plants analyzed to date. In many plants......, the CslA genes are members of extended multigene families; however, it is not known whether all CslA proteins are glucomannan synthases. CslA proteins from diverse land plant species, including representatives of the mono- and dicotyledonous angiosperms, gymnosperms, and bryophytes, were produced in...

  16. DIVERSITY AND ENDEMICITY OF CHILIMO FOREST, CENTRAL ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Teshome Soromessa

    2013-01-01

    Full Text Available Studies on the regeneration, structural and uses of some woody species in Chilimo Forest, one of the dry Afromontane Forests of Ethiopia were conducted. To gather vegetation and environmental data from the study forest, a 900 m2 (30 m x 30 m quadrat was laid following the homogeneity of vegetation. All together the plant species recorded from Chilimo Forest are 213 which can be categorised into 83 families. Of these, the highest proportion is the angiosperm (represented by 193 species followed by pteridophyta (16 species; the least represented being the gymnosperms (represented by 2 exotic and 2 indigenous species. To provide a better management and monitoring as well as to maintain the biodiversity, cultural and economic values of the forest unsustainable utility of the forest would be controlled with the various conservation activities in place.

  17. Paleoecology and Paleoenvironmental Interpretations of the Late Cretaceous Lower Cantwell Formation, Denali National Park, Alaska

    Science.gov (United States)

    Tomsich, C. S.; Salazar Jaramillo, S.; Jacobus, R. T.; McCarthy, P. J.; Fowell, S. J.; Fiorillo, A. R.

    2010-12-01

    The level of diversity of an ancient high-latitude fauna or flora is of interest not just for the study of species evolution and paleogeographic migration patterns, but also for the imminent response to an amplified climate change rate. Climate modelers thus focus increasingly on proxies of Polar Regions. A rich floral and faunal record indicative of a warm high-latitude paleoclimate is presently emerging from the late Campanian-Maastrichtian lower Cantwell Formation in Denali National Park, south-central Alaska. This thick (up to 4000m) alluvial fan succession was deposited during the latest accretionary phase of the Wrangellia terrane to the former southern margin of Alaska. Facies descriptions from outcrops near Sable Mountain and Polychrome Mountain record heterogeneous and laterally discontinuous lithologies characteristic of alluvial and marginal alluvial fan environments: braided channel, sandy channel, crevasse splay, sheetflood, floodplain, and lacustrine. Trace and plant fossils occur predominantly at lithological boundaries. The vertebrate fossil record encompasses tracks that can be attributed to fishes, pterosaurs, large and small non-avian theropods, birds, hadrosaurs, and ceratopsians. Hadrosaur footprints are abundant and record populations with multiple generations present. The pterosaur tracks constitute the northernmost fossil occurrence for these flying reptiles. Bird traces range from small, shore-wading bird tracks to those of a large crane-like bird. Diverse invertebrate tracks include freshwater bivalve, ostracode and gastropod trails, crayfish burrows, beetle and mole cricket tracks, wood borings and feeding traces on angiosperm leaves. Plant impression fossils represent dicotyledonous angiosperm leaves referable to nymphaealean, menispermoid, platanoid, trochodendroid and higher hamamelid groups; magnoliid seeds; diverse broad-leaved and blade-like monocot leaf fragments; the leafy shoots, leaves, cones, seeds and wood of cupressaceous and

  18. A Decrease in Ambient Temperature Induces Post-Mitotic Enlargement of Palisade Cells in North American Lake Cress.

    Directory of Open Access Journals (Sweden)

    Rumi Amano

    Full Text Available In order to maintain organs and structures at their appropriate sizes, multicellular organisms orchestrate cell proliferation and post-mitotic cell expansion during morphogenesis. Recent studies using Arabidopsis leaves have shown that compensation, which is defined as post-mitotic cell expansion induced by a decrease in the number of cells during lateral organ development, is one example of such orchestration. Some of the basic molecular mechanisms underlying compensation have been revealed by genetic and chimeric analyses. However, to date, compensation had been observed only in mutants, transgenics, and γ-ray-treated plants, and it was unclear whether it occurs in plants under natural conditions. Here, we illustrate that a shift in ambient temperature could induce compensation in Rorippa aquatica (Brassicaceae, a semi-aquatic plant found in North America. The results suggest that compensation is a universal phenomenon among angiosperms and that the mechanism underlying compensation is shared, in part, between Arabidopsis and R. aquatica.

  19. Speed dating, rejection, and finding the perfect mate: advice from flowering plants.

    Science.gov (United States)

    Beale, Kristin M; Johnson, Mark A

    2013-10-01

    Angiosperm pollen tubes extend through pistil tissue to deliver a pair of immotile sperm cells to female gametes for double fertilization. The extended journey of the pollen tube requires extensive cell:cell interactions that guide the pollen tube to its destination and instruct it to stop growing and burst. Once sperm cells are released the molecular exchanges between male and female continue, resulting in sperm activation and gamete fusion. Finally, there is evidence that gamete fusion can feed back on the pollen tube attraction mechanism so that additional pollen tubes can be attracted only if the first sperm cells fail to fertilize. We review progress toward defining the molecules mediating each of these exchanges and describe how small cysteine-rich peptides are a major mode of cellular communication. PMID:24021868

  20. Traditional drug therapies from various medicinal plants of central Karakoram National Park, Gilgit-Baltistan, Pakistan

    International Nuclear Information System (INIS)

    Traditional medicines derived from indigenous plants play an important role in treating infectious diseases. This study examined traditional medicinal uses of indigenous plants and documented different traditional recipes used by local communities to treat different diseases in Baltistan Region. Forty-seven medicinal plants belonging to 22 families were collected. Twenty-one families were angiosperms, one was a pteridophyte (Equisetaceae), and one a gymnosperm (Ephedraceae). Crude extracts of these medicinal plants were used by the local people for treating diseases in a traditional system of medicine. Ranunculaceae, Asteraceae, Polygonaceae and Rosaceae were the most important families, each having five species with medicinal value. The species were found across a wide range of altitudes, from 2000 m to over 4000 m. (author)

  1. Seedling stage strategies as a means of habitat specialization in herbaceous plants

    DEFF Research Database (Denmark)

    ten Brink, Dirk-Jan; Bruun, Hans Henrik

    2011-01-01

    The regeneration niche has been little investigated in studies of community assembly and plant distribution. We examined adaptive associations between seedling traits and habitat specialization. Two habitat contrasts were investigated across several evolutionary lineages of angiosperms: species...... degree of elongation (longest internode; petiole or leaf-sheath depending on species' morphology) to light and watering treatments was assessed. We used a factorial design involving three light regimes and two watering frequencies. The open-shaded habitat contrast and the dry-wet habitat contrast were...... the moist-habitat species, for which elongation increased with shade. Contrary to our expectations, species from dry habitats grew bigger than species from moist habitats in all treatments. SLA responded to the light treatment, but not to watering regime. The contrasting light and moisture conditions...

  2. Dynamics of chloroplast genomes in green plants.

    Science.gov (United States)

    Xu, Jian-Hong; Liu, Qiuxiang; Hu, Wangxiong; Wang, Tingzhang; Xue, Qingzhong; Messing, Joachim

    2015-10-01

    Chloroplasts are essential organelles, in which genes have widely been used in the phylogenetic analysis of green plants. Here, we took advantage of the breadth of plastid genomes (cpDNAs) sequenced species to investigate their dynamic changes. Our study showed that gene rearrangements occurred more frequently in the cpDNAs of green algae than in land plants. Phylogenetic trees were generated using 55 conserved protein-coding genes including 33 genes for photosynthesis, 16 ribosomal protein genes and 6 other genes, which supported the monophyletic evolution of vascular plants, land plants, seed plants, and angiosperms. Moreover, we could show that seed plants were more closely related to bryophytes rather than pteridophytes. Furthermore, the substitution rate for cpDNA genes was calculated to be 3.3×10(-10), which was almost 10 times lower than genes of nuclear genomes, probably because of the plastid homologous recombination machinery. PMID:26206079

  3. Evolution of Electrogenic Ammonium Transporters (AMTs).

    Science.gov (United States)

    McDonald, Tami R; Ward, John M

    2016-01-01

    The ammonium transporter gene family consists of three main clades, AMT, MEP, and Rh. The evolutionary history of the AMT/MEP/Rh gene family is characterized by multiple horizontal gene transfer events, gene family expansion and contraction, and gene loss; thus the gene tree for this family of transporters is unlike the organismal tree. The genomes of angiosperms contain genes for both electrogenic and electroneutral ammonium transporters, but it is not clear how far back in the land plant lineage electrogenic ammonium transporters occur. Here, we place Marchantia polymorpha ammonium transporters in the AMT/MEP/Rh phylogeny and we show that AMTs from the liverwort M. polymorpha are electrogenic. This information suggests that electrogenic ammonium transport evolved at least as early as the divergence of bryophytes in the land plant lineage. PMID:27066024

  4. Patterns and drivers of plant functional group dominance across the Western Hemisphere: a macroecological re-assessment based on a massive botanical dataset

    DEFF Research Database (Denmark)

    Jensen, Kristine Engemann; Sandel, Brody Steven; Enquist, Brian;

    2016-01-01

    standardized plant species occurrence dataset of unprecedented size covering the entire New World. Functional group distributions were estimated from 3 648 533 standardized occurrence records for a total of 83 854 vascular plant species, extracted from the Botanical Information and Ecology Network (BIEN......Plant functional group dominance has been linked to climate, topography and anthropogenic factors. Here, we assess existing theory linking functional group dominance patterns to their drivers by quantifying the spatial distribution of plant functional groups at a 100-km grid scale. We use a......) database. Seven plant functional groups were considered, describing major differences in structure and function: epiphytes; climbers; ferns; herbs; shrubs; coniferous trees; and angiosperm trees. Two measures of dominance (relative number of occurrences and relative species richness) were analysed against...

  5. Architecture and evolution of a minute plant genome.

    Science.gov (United States)

    Ibarra-Laclette, Enrique; Lyons, Eric; Hernández-Guzmán, Gustavo; Pérez-Torres, Claudia Anahí; Carretero-Paulet, Lorenzo; Chang, Tien-Hao; Lan, Tianying; Welch, Andreanna J; Juárez, María Jazmín Abraham; Simpson, June; Fernández-Cortés, Araceli; Arteaga-Vázquez, Mario; Góngora-Castillo, Elsa; Acevedo-Hernández, Gustavo; Schuster, Stephan C; Himmelbauer, Heinz; Minoche, André E; Xu, Sen; Lynch, Michael; Oropeza-Aburto, Araceli; Cervantes-Pérez, Sergio Alan; de Jesús Ortega-Estrada, María; Cervantes-Luevano, Jacob Israel; Michael, Todd P; Mockler, Todd; Bryant, Douglas; Herrera-Estrella, Alfredo; Albert, Victor A; Herrera-Estrella, Luis

    2013-06-01

    It has been argued that the evolution of plant genome size is principally unidirectional and increasing owing to the varied action of whole-genome duplications (WGDs) and mobile element proliferation. However, extreme genome size reductions have been reported in the angiosperm family tree. Here we report the sequence of the 82-megabase genome of the carnivorous bladderwort plant Utricularia gibba. Despite its tiny size, the U. gibba genome accommodates a typical number of genes for a plant, with the main difference from other plant genomes arising from a drastic reduction in non-genic DNA. Unexpectedly, we identified at least three rounds of WGD in U. gibba since common ancestry with tomato (Solanum) and grape (Vitis). The compressed architecture of the U. gibba genome indicates that a small fraction of intergenic DNA, with few or no active retrotransposons, is sufficient to regulate and integrate all the processes required for the development and reproduction of a complex organism. PMID:23665961

  6. Spectrum of allergenic pollen in Karachi and their characterization using conventional and electron microscopy: Potential candidates for allergy vaccines

    International Nuclear Information System (INIS)

    Objective: To study the distribution of naturally growing plants with possible allergenic potential and study their pollen morphology in Karachi, Pakistan. Methodology: We performed field surveys of naturally growing plants with possible allergenic potential and studied their pollen morphology using conventional (light) as well as scanning electron microscopy. Results: About 80 allergenic pollen producing species were identified which are distributed in 45 genera and 9 angiospermic families. Grasses belonging to Graminae are most abundant followed by plants from family Fabaceae (Leguminosae). Highly allergenic weeds were also found widely growing in the city areas belonging to Amaranthaceae/Chenopodiaceae family. Conclusion: Our study provides an updated information about the allergenic plants growing in Karachi city. All desensitization efforts should be designed in accordance to the available information regarding the prevalent allergens in the environment so that appropriate therapy can be given to the affected population. (author)

  7. Fossil Leaves and Fossil Leaf n-Alkanes: Reconstructing the First Closed Canopied Rainforests

    Science.gov (United States)

    Graham, H. V.; Freeman, K. H.

    2013-12-01

    Although the age and location is disputed, the rise of the first closed-canopy forest is likely linked with the expansion of angiosperms in the late Cretacous or early Cenozoic. The carbon isotope 'canopy effect' reflects the extent of canopy closure, and is well documented in δ13C values of the leaves and leaf lipids in modern forests. To test the extent of canopy closure among the oldest documented angiosperm tropical forests, we analyzed isotopic characteristics of leaf fossils and leaf waxes from the Guaduas and Cerrejón Formations. The Guaduas Fm. (Maastrichtian) contains some of the earliest angiosperm fossils in the Neotropics, and both leaf morphology and pollen records at this site suggest an open-canopy structure. The Cerrejón Fm. (Paleocene) contains what are believed to be the first recorded fossil leaves from a closed-canopy forest. We analyzed the bulk carbon isotope content (δ13Cleaf) of 199 fossil leaves, as well as the n-alkane concentration and chain-length distribution, and δ13C of alkanes (δ13Clipid) of 73 fossil leaves and adjacent sediment samples. Fossil leaves are dominated by eudicots and include ten modern plant families (Apocynaceae, Bombaceae, Euphorbaceae, Fabaceae, Lauraceae, Malvaceae, Meliaceae, Menispermaceae, Moraceae, Sapotaceae). We interpreted extent of canopy coverage based on the range of δ13Cleaf values. The narrow range of δ13C values in leaves from the Guaduas Fm (2.7‰) is consistent with an open canopy. A significantly wider range in values (6.3‰) suggests a closed-canopy signature for site 0315 of the Cerrejón Fm,. In contrast, at Site 0318, a lacustrine deposit, leaves had a narrow range (3.3‰) in δ13C values, and this is not consistent with a closed-canopy, but is consistent with leaf assemblages from a forest edge. Leaves that accumulate in lake sediments tend to be biased toward plants living at the lake edge, which do not experience closed-canopy conditions, and do not express the isotopic

  8. Genomic sequence of the xylose fermenting, insect-inhabitingyeast, Pichia stipitis

    Energy Technology Data Exchange (ETDEWEB)

    Jeffries, Thomas W.; Grigoriev, Igor; Grimwood, Jane; Laplaza,Jose M.; Aerts, Andrea; Salamov, Asaf; Schmutz, Jeremy; Lindquist, Erika; Dehal, Paramvir; Shapiro, Harris; Jin, Yong-Su; Passoth, Volkmar; Richardson, Paul M.

    2007-06-25

    Xylose is a major constituent of angiosperm lignocellulose,so its fermentation is important for bioconversion to fuels andchemicals. Pichia stipitis is the best-studied native xylose fermentingyeast. Genes from P. stipitis have been used to engineer xylosemetabolism in Saccharomycescerevisiae, and the regulation of the P.stipitis genome offers insights into the mechanisms of xylose metabolismin yeasts. We have sequenced, assembled and finished the genome ofP.stipitis. As such, it is one of only a handful of completely finishedeukaryotic organisms undergoing analysis and manual curation. Thesequence has revealed aspects of genome organization, numerous genes forbiocoversion, preliminary insights into regulation of central metabolicpathways, numerous examples of co-localized genes with related functions,and evidence of how P. stipitis manages to achieve redox balance whilegrowing on xylose under microaerobic conditions.

  9. Le recensement des plantes vasculaires et les originalités du peuplement végétal des monts Loma en Sierra Leone (Afrique Occidentale

    Directory of Open Access Journals (Sweden)

    P. Jaeger

    1983-12-01

    Full Text Available A FLOR1STIC INVENTORY OF THE LOMA MOUNTAINS IN SIERRA LEONE Our surveys in Sierra Leone of the flora of the Loma Mountains and the foothill country have enabled us to produce an inventory of the I 576 species, subspecies or varieties of Angiosperms belonging to 757 genera and 135 families. Gymnosperms are lacking. As in any other natural region, the Loma flora is the result of a long and complex process which took place in much earlier times. Under the influence of climatic factors, migration, speciation and also anthropological action, floristic elements with very different origins have ultimately arranged themselves into a particularly diversified but unstable mosaic and it is for us to unravel the mechanisms that have brought this about.

  10. The complete plastid genome of Piper kadsura (Piperaceae), an East Asian woody vine.

    Science.gov (United States)

    Lee, Jung-Hyun; Choi, In-Su; Choi, Byoung-Hee; Yang, Sungyu; Choi, Goya

    2016-09-01

    We sequenced the complete plastid genome (plastome) for Piper kadsura, a woody vine endemic to East Asia. This species is part of the largest genus within Piperaceae and its genome is almost identical to its congener P. cenocladum. The plastome for P. kadsura comprises 131 genes, including four unique rRNAs, 30 tRNAs, and 79 protein-coding genes. It retains ycf1 as an intact open reading frame. Our phylogenetic analysis demonstrated the monophyly of the Piper genus. The additional plastome sequence found in this evolutionarily and economically important genus will be a valuable, fundamental tool for future studies of phylogenetic relationships among basal angiosperms, and will provide a useful resource for molecular breeding programs. PMID:26260180

  11. Effects of rapid global warming at the Paleocene-Eocene boundary on neotropical vegetation.

    Science.gov (United States)

    Jaramillo, Carlos; Ochoa, Diana; Contreras, Lineth; Pagani, Mark; Carvajal-Ortiz, Humberto; Pratt, Lisa M; Krishnan, Srinath; Cardona, Agustin; Romero, Millerlandy; Quiroz, Luis; Rodriguez, Guillermo; Rueda, Milton J; de la Parra, Felipe; Morón, Sara; Green, Walton; Bayona, German; Montes, Camilo; Quintero, Oscar; Ramirez, Rafael; Mora, Germán; Schouten, Stefan; Bermudez, Hermann; Navarrete, Rosa; Parra, Francisco; Alvarán, Mauricio; Osorno, Jose; Crowley, James L; Valencia, Victor; Vervoort, Jeff

    2010-11-12

    Temperatures in tropical regions are estimated to have increased by 3° to 5°C, compared with Late Paleocene values, during the Paleocene-Eocene Thermal Maximum (PETM, 56.3 million years ago) event. We investigated the tropical forest response to this rapid warming by evaluating the palynological record of three stratigraphic sections in eastern Colombia and western Venezuela. We observed a rapid and distinct increase in plant diversity and origination rates, with a set of new taxa, mostly angiosperms, added to the existing stock of low-diversity Paleocene flora. There is no evidence for enhanced aridity in the northern Neotropics. The tropical rainforest was able to persist under elevated temperatures and high levels of atmospheric carbon dioxide, in contrast to speculations that tropical ecosystems were severely compromised by heat stress. PMID:21071667

  12. Observations on the Biology and Anatomy of Myerslopiidae (Hemiptera, Membracoidea

    Directory of Open Access Journals (Sweden)

    Roman Rakitov

    2015-01-01

    Full Text Available Adults and nymphs of Mapuchea chilensis (Nielson, from the poorly known family Myerslopiidae, were collected from the litter horizon of temperate forests and shrub bogs in southern Chile. The species apparently feeds on roots and creeping stems of angiosperms. Salivary sheaths of captive specimens terminated in vascular bundles. Indirect evidence suggests feeding on phloem sap. Both nymphs and adults are strong jumpers and both actively disperse, as evidenced by their capture in pan traps. The Malpighian tubules of this species produce no brochosomes and, unlike in most previously studied Membracoidea, comprise no specialized secretory segment. Each tubule comprises secretory cells scattered among excretory ones, a condition not previously known among Hemiptera.

  13. Release of volatile mercury from vascular plants

    Science.gov (United States)

    Siegel, S. M.; Puerner, N. J.; Speitel, T. W.

    1974-01-01

    Volatile, organic solvent soluble mercury has been found in leaves and seeds of several angiosperms. Leaves of garlic vine, avocado, and haole-koa release mercury in volatile form rapidly at room temperature. In garlic vine, the most active release is temperature dependent, but does not parallel the vapor-pressure temperature relationship for mercury. Mercury can be trapped in nitric-perchloric acid digestion fluid, or n-hexane, but is lost from the hexane unless the acid mixture is present. Seeds of haole-koa also contain extractable mercury but volatility declines in the series n-hexane (90%), methanol (50%), water (10%). This suggests that reduced volatility may accompany solvolysis in the more polar media.

  14. Molecular composition, chemotaxonomical aspects and botanical origin of Brazilian amber [Composição molecular, aspectos quimiotaxonômicos e origem botânica de âmbares brasileiros

    Directory of Open Access Journals (Sweden)

    Débora A. Azevedo

    2011-06-01

    Full Text Available Amber is a plant fossil resin constituted mainly by diterpenes of several classes, such as abietanes, labdanes, pimaranes and kauranes. The botanical origin of amber is related to angiosperms and gymnosperms, depending on the geological period and where it was produced. The analysis of its chemical composition performed using gas chromatography coupled to mass spectrometry and carbon 13 nuclear magnetic resonance allows the determination of the possible botanical sources, allowing obtaining important information regarding the resinous flora on the geological past of the Earth. Although amber samples are studied primarily by geochemists and paleontologists in the context of paleobotany and paleozoology, the research about its molecular composition is directly related to chemotaxonomy and phytochemistry. The results obtained to Brazilian amber samples until this moment allowed the determination of three possible amber botanical sources in Cretaceous period – Araucariaceae, Podocarpaceae e Cheirolepidiaceae.

  15. Ornithogalum virens as a plant assay for beta and gamma radiation effects

    International Nuclear Information System (INIS)

    The purpose of this study was to determine if the monocotyledonous angiosperm, Ornithogalum virens (Quintanilha and Cabral, 1947), could be used in such a biological assay system. After exposing O. virens plants to acute (60Co) and chronic (137Cs) gamma radiation and internal beta radiation (32P), lethality (LD50, LD100), growth inhibition, and chromosome aberrations were investigated. The LD50 and LD100 for acute gamma radiation were estimated to be between 0.91 to 1.8 krad and less than 3.6 krad, respectively. Though growth inhibition and abnormal growth were observed in the acute and chronic gamma radiation studies, the changes in the growth of the plants were so variable that these parameters were found to be unreliable measures of radiation effects. Chromosome aberrations were a more reliable measure of radiation damage because linear relationships between total aberrations and dose were found for both gamma and beta radiation

  16. The Genome of a Southern Hemisphere Seagrass Species (Zostera muelleri).

    Science.gov (United States)

    Lee, HueyTyng; Golicz, Agnieszka A; Bayer, Philipp E; Jiao, Yuannian; Tang, Haibao; Paterson, Andrew H; Sablok, Gaurav; Krishnaraj, Rahul R; Chan, Chon-Kit Kenneth; Batley, Jacqueline; Kendrick, Gary A; Larkum, Anthony W D; Ralph, Peter J; Edwards, David

    2016-09-01

    Seagrasses are marine angiosperms that evolved from land plants but returned to the sea around 140 million years ago during the early evolution of monocotyledonous plants. They successfully adapted to abiotic stresses associated with growth in the marine environment, and today, seagrasses are distributed in coastal waters worldwide. Seagrass meadows are an important oceanic carbon sink and provide food and breeding grounds for diverse marine species. Here, we report the assembly and characterization of the Zostera muelleri genome, a southern hemisphere temperate species. Multiple genes were lost or modified in Z. muelleri compared with terrestrial or floating aquatic plants that are associated with their adaptation to life in the ocean. These include genes for hormone biosynthesis and signaling and cell wall catabolism. There is evidence of whole-genome duplication in Z. muelleri; however, an ancient pan-commelinid duplication event is absent, highlighting the early divergence of this species from the main monocot lineages. PMID:27373688

  17. Miocene woods from the Qaidam Basin on northern Qinghai-Tibet Plateau with implications for paleoenvironmental change

    Science.gov (United States)

    Cheng, Ye-Ming; Yang, Xiao-Nan

    2016-02-01

    The Qaidam Basin with the most complete Cenozoic sedimentary preservation in northern Qinghai-Tibet Plateau is a key area for studying uplift and environmental change of the plateau. Three types of woods, Ulmus (Ulmaceae), Leguminosae (?) (angiosperm) and Cupressaceae (gymnosperm) were recognized from the large-scale preservation of fossil woods in late Miocene Shang Youshashan Formation in northern Qaidam Basin on the Qinghai-Tibet Plateau. Both investigations of their Nearest Living Relatives (NLRs) and previous grassland mammal evidences suggest that there have been temperate deciduous broad-leaved forest and needle-leaved forest with grass in northern Qaidam Basin during the late Miocene in contrast to the desert vegetation found there nowadays. The presence of the ancient forest steppe further implies that the southern part of the plateau used to be adequately low, so that the Indian and East Asian monsoons could approach the northern area and to accommodate the vegetation in late Miocene.

  18. Traditional Medicinal Flora of the District Buxar (Bihar, India

    Directory of Open Access Journals (Sweden)

    Ritesh Singh

    2013-07-01

    Full Text Available Buxar district (Bihar,India is one of the less floristically studied regions of central Gangetic plain. The district lacks dense forests and its medicinal flora exclusively consists of dicot angiosperms. A total of 84 species belonging to 27 families were reported in this study. Majority of the reported plants were herbs with highest contribution from family Fabaceae (12. The present paper deals with the traditional uses of these plants. Plants and their part thereof were used to treat diseases such as - malaria, small pox, leprosy, diarrhea, diabetes, rheumatisms, hepatitis A, heart problems, elephantiasis, STDs, asthma, dysentery, in pregnancy complications and against snake and scorpion poisons. Findings will help in conservation and cultivation of these plants.

  19. Spermatophyte Flora Distribution in Hubei Daqi Mountain Nature Reserve

    Institute of Scientific and Technical Information of China (English)

    Zhengyu; LEI; Jingyong; CAI; Tao; BAI; Jianguo; JIANG; Shaoming; WANG

    2013-01-01

    A basic ingredient analysis of flora and geographic elements of plant genera and families in Daqi Mountain Nature Reserve was conducted through the field survey and specimen collection,based on the system investigation of plant flora,and an R/T ratio comparison between the flora in Daqi Mountain and adjacent mountain floras was made.Plant taxonomy identification indicates that spermatophytes in the nature reserve comprises 1035 species of 534 genera,falling in 140families,of which 10 gymnosperm species of 8 genera fall in 5 families,while 1025angiosperm species of 526 genera in 135 families.The analysis of flora demonstrates that the region harbors 15 flora distribution types,with high complexity,paleo-flora origin,distinct trait of temperate zone,abundant ingredient of tropical zone,and close connection with the flora of East China.

  20. Exploring Diversification and Genome Size Evolution in Extant Gymnosperms through Phylogenetic Synthesis

    Directory of Open Access Journals (Sweden)

    J. Gordon Burleigh

    2012-01-01

    Full Text Available Gymnosperms, comprising cycads, Ginkgo, Gnetales, and conifers, represent one of the major groups of extant seed plants. Yet compared to angiosperms, little is known about the patterns of diversification and genome evolution in gymnosperms. We assembled a phylogenetic supermatrix containing over 4.5 million nucleotides from 739 gymnosperm taxa. Although 93.6% of the cells in the supermatrix are empty, the data reveal many strongly supported nodes that are generally consistent with previous phylogenetic analyses, including weak support for Gnetales sister to Pinaceae. A lineage through time plot suggests elevated rates of diversification within the last 100 million years, and there is evidence of shifts in diversification rates in several clades within cycads and conifers. A likelihood-based analysis of the evolution of genome size in 165 gymnosperms finds evidence for heterogeneous rates of genome size evolution due to an elevated rate in Pinus.