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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

    Energy Technology Data Exchange (ETDEWEB)

    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. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  4. Schmeissneria: An angiosperm from the Early Jurassic

    Institute of Scientific and Technical Information of China (English)

    Xin WANG

    2010-01-01

    The origin of angiosperms has been a focus of intensive research for a long time. The so-called preCretaceous angiosperms, including Schmeissneria, are usually clouded with doubt. To expel the cloud around the enigmatic Schmeissneria, the syntype and new materials of Schmeissneria collected previously in Germany and recently in China are studied. These materials include female inflorescences and infructescences. The latter are old materials but were under-studied previously. Light microscopy and scanning electron microscope observations indicate that the fruits in these infructescences have in situ seeds enclosed, and that the ovaries are closed before pollination. Thus the plants meet two strict criteria for angiosperms: angiospermy plus angio-ovuly. Placing Schmeissneria in angiosperms will extend the record of angiosperms up to the Early Jurassic, more compatible with many molecular dating conclusions on the age of angiosperms, and demanding a reassessment of the current doctrines on the origin of angiosperms. Although the phylogenetic relationship of Schmeissneria to other angiosperms apparently is still an open question, this study adds to research concerning the origin of angiosperms.

  5. 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.

  6. Changes in macroelement content of rhizomes of Nuphar lutea (L. Sibith. and Sm. during the annual cycle

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    Henryk Tomaszewicz

    2011-04-01

    Full Text Available This study presents the results of studies on the chemical composition of rhizomes of Nuphar lutea which were carried out from July 2006 to November 2007 (the samples were collected at two-week intervals from March to November 2007. The first indication of the start of the growing season was the growth of leaves in the apical part of the rhizomes. Clearly visible signs that marked the beginning of the growing season were unfolding of leaves, which became arrow-shaped. The leaves had already unfolded and were arrow-shaped (saggitate on April 10th when the temperature of the bottom water layer was 7oC. It may be assumed, therefore, that the growing season began between the 28th March and 10th April 2007. The phosphates, nitrates, sodium, calcium, total iron and sulphates levels in the rhizomes declined just after the growing season had started. The total nitrogen content remained at a constant level whereas the amount of dissolved silica increased. Considerable changes in the macroelement contents were noted when Nuphar lutea was in full bloom (10th-24th June. The macroelement contents presented in the tables and diagrams were expressed on a dry matter basis. An additional table illustrates the macroelement contents expressed on a fresh matter basis. The problem of collecting rhizomes of polycormic plants is discussed.

  7. The Early Flowers and Angiosperm Evolution

    DEFF Research Database (Denmark)

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

    The recent discovery of diverse fossil flowers and floral organs in Cretaceous strata has revealed astonishing details about the structural and systematic diversity of early angiosperms. Exploring the rich fossil record that has accumulated over the last three decades, this is a unique study...... 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 latest research in the field, highlighting connections with phylogenetic systematics, structure and the biology of extant angiosperms....

  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

    OpenAIRE

    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. An Undercover Angiosperm from the Jurassic of China

    Institute of Scientific and Technical Information of China (English)

    ZHENG Shaolin; WANG Xin

    2010-01-01

    Searching for early angiosperms is a riveting activity in botany because it helps to resolve the phylogenetic relationships among seed plants and among angiosperms themselves.One of the challenges for this job is what the target fossils look like.Most possibly early angiosperms may elude our scrutiny with gymnospermous appearances.This possibility becomes a reality in a Jurassic plant,Solaranthus gen.nov,which bears a peltaspermalean appearance and enclosed ovules.According to knowledge available hitherto,the latter feature makes it an angiosperm.However,such a feature is more likely to be eclipsed by its gymnospermous appearance.The early age and unexpected character assemblage of Solaranthus urge for a fresh look on the assumed-simple relationship between angiosperms and gymnosperms.Its resemblance to the order Peltaspermales favors the Mostly Male Theory.

  11. 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.

  12. Fruit evolution and diversification in campanulid angiosperms.

    Science.gov (United States)

    Beaulieu, Jeremy M; Donoghue, Michael J

    2013-11-01

    With increases in both the size and scope of phylogenetic trees, we are afforded a renewed opportunity to address long-standing comparative questions, such as whether particular fruit characters account for much of the variation in diversity among flowering plant clades. Studies to date have reported conflicting results, largely as a consequence of taxonomic scale and a reliance on potentially conservative statistical measures. Here we examine a larger and older angiosperm clade, the Campanulidae, and infer the rates of character transitions among the major fruit types, emphasizing the evolution of the achene fruits that are most frequently observed within the group. Our analyses imply that campanulids likely originated bearing capsules, and that all subsequent fruit diversity was derived from various modifications of this dry fruit type. We also found that the preponderance of lineages bearing achenes is a consequence of not only being a fruit type that is somewhat irreversible once it evolves, but one that also seems to have a positive association with diversification rates. Although these results imply the achene fruit type is a significant correlate of diversity patterns observed across campanulids, we conclude that it remains difficult to confidently and directly view this character state as the actual cause of increased diversification rates.

  13. Plant Sterol Diversity in Pollen from Angiosperms.

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    Villette, Claire; Berna, Anne; Compagnon, Vincent; Schaller, Hubert

    2015-08-01

    Here we have examined the composition of free sterols and steryl esters of pollen from selected angiosperm species, as a first step towards a comprehensive analysis of sterol biogenesis in the male gametophyte. We detected four major sterol structural groups: cycloartenol derivatives bearing a 9β,19-cyclopropyl group, sterols with a double bond at C-7(8), sterols with a double bond at C-5(6), and stanols. All these groups were unequally distributed among species. However, the distribution of sterols as free sterols or as steryl esters in pollen grains indicated that free sterols were mostly Δ(5)-sterols and that steryl esters were predominantly 9β,19-cyclopropyl sterols. In order to link the sterol composition of a pollen grain at anthesis with the requirement for membrane lipid constituents of the pollen tube, we germinated pollen grains from Nicotiana tabacum, a model plant in reproductive biology. In the presence of radiolabelled mevalonic acid and in a time course series of measurements, we showed that cycloeucalenol was identified as the major neosynthesized sterol. Furthermore, the inhibition of cycloeucalenol neosynthesis by squalestatin was in full agreement with a de novo biogenesis and an apparent truncated pathway in the pollen tube.

  14. 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

  15. Herbaceous Angiosperms Are Not More Vulnerable to Drought-Induced Embolism Than Angiosperm Trees1[OPEN

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    Delmas, Chloé E.L.; Buttler, Alexandre; Chauvin, Thibaud; Doria, Larissa Chacon; del Arco, Marcelino

    2016-01-01

    The water transport pipeline in herbs is assumed to be more vulnerable to drought than in trees due to the formation of frequent embolisms (gas bubbles), which could be removed by the occurrence of root pressure, especially in grasses. Here, we studied hydraulic failure in herbaceous angiosperms by measuring the pressure inducing 50% loss of hydraulic conductance (P50) in stems of 26 species, mainly European grasses (Poaceae). Our measurements show a large range in P50 from −0.5 to −7.5 MPa, which overlaps with 94% of the woody angiosperm species in a worldwide, published data set and which strongly correlates with an aridity index. Moreover, the P50 values obtained were substantially more negative than the midday water potentials for five grass species monitored throughout the entire growing season, suggesting that embolism formation and repair are not routine and mainly occur under water deficits. These results show that both herbs and trees share the ability to withstand very negative water potentials without considerable embolism formation in their xylem conduits during drought stress. In addition, structure-function trade-offs in grass stems reveal that more resistant species are more lignified, which was confirmed for herbaceous and closely related woody species of the daisy group (Asteraceae). Our findings could imply that herbs with more lignified stems will become more abundant in future grasslands under more frequent and severe droughts, potentially resulting in lower forage digestibility. PMID:27268961

  16. 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.

  17. 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.

  18. Lower Cretaceous angiosperm leaf from Wuhe in Anhui, China

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new early angiosperm leaf species is reported from the Xinzhuang Formation in Wuhe County, Anhui Province. It is probably of Barremian or slightly later in geological age. The fossil leaf is small, no more than 0.6 cm both in length and in width. The leaf veins are well preserved and clearly visible under a low power microscope. Leaf architectural analysis shows that such a leaf should belong to the first leaf rank of Hickey, I.e. The most primitive one. There are no early angiosperm leaves published completely similar to ours. A new species name of Dicotylophyllum minutissimum sp. Nov. Is established for the present leaf fossils.

  19. 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

  20. 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.

  1. 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...

  2. 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.

  3. 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...

  4. 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.

  5. 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

  6. 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

  7. Statistical analysis on adaptive evolution of SQUA genes in angiosperms

    Institute of Scientific and Technical Information of China (English)

    CHEN Yongyan; ZHONG Yang; TIAN Bo; YANG Ji; LI Dezhu

    2005-01-01

    SQUAMOSA (SQUA) subfamily includes important perianth identity genes of MADS-box gene family. SQUA genes of Dendrocalamus latiflorus were sequenced, and phylogenetic form on SQUA genes in angiosperms was analyzed. Relative rate and adaptive evolution after SQUA gene duplication in recent common ancestor of monocots and eudicots were analyzed using the methods of relative rate test, statistic on synonymous and non-synonymous coden substitution sites and likelihood rate test. The results show that both of relative rate and synonymous and non-synonymous coden substitution in eudicot clade are significantly higher than those in monocot clade, and the value of dN/ds uncovered possible positive selective pressure in eudicot clade.

  8. The Pace and Shape of Senescence in Angiosperms

    DEFF Research Database (Denmark)

    Baudisch, Annette; Salguero-Gómez, Roberto; Jones, Owen;

    2013-01-01

    (‘senescence’), decreases (‘negative senescence’) or remains constant over age (‘negligible senescence’). 3. We extract mortality trajectories from ComPADRe III, a data base that contains demographic information for several hundred plant species. We apply age-from-stage matrix decomposition methods to obtain...... age-specific trajectories from 290 angiosperm species of various growth forms distributed globally. From these trajectories, we survey pace and shape values and investigate how growth form and ecoregion influence these two aspects of mortality using a Bayesian regression analysis that accounts...... analysis that accounts for phylogenetic history and in the distinction between metrics of pace and shape as two separate aspects of mortality. We believe that our approach could prove useful in future comparative studies of mortality patterns....

  9. Early Cretaceous Archaeamphora is not a carnivorous angiosperm

    Directory of Open Access Journals (Sweden)

    William Oki Wong

    2015-05-01

    Full Text Available Archaeamphora longicervia H.Q.Li was described as an herbaceous, Sarraceniaceae-like pitcher plant from the mid Early Cretaceous Yixian Formation of Liaoning Province, northeastern China. Here, a re-investigation of A. longicervia specimens from the Yixian Formation provides new insights into its identity and the morphology of pitcher plants claimed by Li. We demonstrate that putative pitchers of Archaeamphora are insect-induced leaf galls that consist of three components: (1 an innermost larval chamber with a distinctive outer wall; (2 an intermediate zone of nutritive tissue; and (3 an outermost zone of sclerenchyma. Archaeamphora is not a carnivorous, Sarraceniaceae-like angiosperm, but represents insect-galled leaves of the formerly reported gymnosperm Liaoningocladus boii G.Sun et al. from the Yixian Formation.

  10. Early Cretaceous Archaeamphora is not a carnivorous angiosperm.

    Science.gov (United States)

    Wong, William Oki; Dilcher, David Leonard; Labandeira, Conrad C; Sun, Ge; Fleischmann, Andreas

    2015-01-01

    Archaeamphora longicervia H. Q. Li was described as an herbaceous, Sarraceniaceae-like pitcher plant from the mid Early Cretaceous Yixian Formation of Liaoning Province, northeastern China. Here, a re-investigation of A. longicervia specimens from the Yixian Formation provides new insights into its identity and the morphology of pitcher plants claimed by Li. We demonstrate that putative pitchers of Archaeamphora are insect-induced leaf galls that consist of three components: (1) an innermost larval chamber; (2) an intermediate zone of nutritive tissue; and (3) an outermost wall of sclerenchyma. Archaeamphora is not a carnivorous, Sarraceniaceae-like angiosperm, but represents insect-galled leaves of the previously reported gymnosperm Liaoningocladus boii G. Sun et al. from the Yixian Formation. PMID:25999978

  11. Exceptional preservation of tiny embryos documents seed dormancy in early angiosperms.

    Science.gov (United States)

    Friis, Else Marie; Crane, Peter R; Pedersen, Kaj Raunsgaard; Stampanoni, Marco; Marone, Federica

    2015-12-24

    The rapid diversification of angiosperms through the Early Cretaceous period, between about 130-100 million years ago, initiated fundamental changes in the composition of terrestrial vegetation and is increasingly well understood on the basis of a wealth of palaeobotanical discoveries over the past four decades and their integration with improved knowledge of living angiosperms. Prevailing hypotheses, based on evidence both from living and from fossil plants, emphasize that the earliest angiosperms were plants of small stature with rapid life cycles that exploited disturbed habitats in open, or perhaps understorey, conditions. However, direct palaeontogical data relevant to understanding the seed biology and germination ecology of Early Cretaceous angiosperms are sparse. Here we report the discovery of embryos and their associated nutrient storage tissues in exceptionally well-preserved angiosperm seeds from the Early Cretaceous. Synchrotron radiation X-ray tomographic microscopy of the fossil embryos from many taxa reveals that all were tiny at the time of dispersal. These results support hypotheses based on extant plants that tiny embryos and seed dormancy are basic for angiosperms as a whole. The minute size of the fossil embryos, and the modest nutrient storage tissues dictated by the overall small seed size, is also consistent with the interpretation that many early angiosperms were opportunistic, early successional colonizers of disturbance-prone habitats.

  12. Heterogeneous Rates of Molecular Evolution and Diversification Could Explain the Triassic Age Estimate for Angiosperms.

    Science.gov (United States)

    Beaulieu, Jeremy M; O'Meara, Brian C; Crane, Peter; Donoghue, Michael J

    2015-09-01

    Dating analyses based on molecular data imply that crown angiosperms existed in the Triassic, long before their undisputed appearance in the fossil record in the Early Cretaceous. Following a re-analysis of the age of angiosperms using updated sequences and fossil calibrations, we use a series of simulations to explore the possibility that the older age estimates are a consequence of (i) major shifts in the rate of sequence evolution near the base of the angiosperms and/or (ii) the representative taxon sampling strategy employed in such studies. We show that both of these factors do tend to yield substantially older age estimates. These analyses do not prove that younger age estimates based on the fossil record are correct, but they do suggest caution in accepting the older age estimates obtained using current relaxed-clock methods. Although we have focused here on the angiosperms, we suspect that these results will shed light on dating discrepancies in other major clades.

  13. 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...

  14. 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.

  15. The angiosperm radiation revisited, an ecological explanation for Darwin's 'abominable mystery'.

    Science.gov (United States)

    Berendse, Frank; Scheffer, Marten

    2009-09-01

    One of the greatest terrestrial radiations is the diversification of the flowering plants (Angiospermae) in the Cretaceous period. Early angiosperms appear to have been limited to disturbed, aquatic or extremely dry sites, suggesting that they were suppressed in most other places by the gymnosperms that still dominated the plant world. However, fossil evidence suggests that by the end of the Cretaceous the angiosperms had spectacularly taken over the dominant position from the gymnosperms around the globe. Here, we suggest an ecological explanation for their escape from their subordinate position relative to gymnosperms and ferns. We propose that angiosperms due to their higher growth rates profit more rapidly from increased nutrient supply than gymnosperms, whereas at the same time angiosperms promote soil nutrient release by producing litter that is more easily decomposed. This positive feedback may have resulted in a runaway process once angiosperms had reached a certain abundance. Evidence for the possibility of such a critical transition to angiosperm dominance comes from recent work on large scale vegetation shifts, linking long-term field observations, large scale experiments and the use of simulation models.

  16. 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

  17. Physiological mechanisms drive differing foliar calcium content in ferns and angiosperms.

    Science.gov (United States)

    Funk, Jennifer L; Amatangelo, Kathryn L

    2013-09-01

    Recent evidence points to ferns containing significantly lower contents of foliar calcium and other cations than angiosperms. This is especially true of more ancient 'non-polypod' fern lineages, which predate the diversification of angiosperms. Calcium is an important plant nutrient, the lack of which can potentially slow plant growth and litter decomposition, and alter soil invertebrate communities. The physiological mechanisms limiting foliar calcium (Ca) content in ferns are unknown. While there is a lot we do not know about Ca uptake and transport in plants, three physiological processes are likely to be important. We measured transpiration rate, cation exchange capacity, and leaching loss to determine which process most strongly regulates foliar Ca content in a range of fern and co-occurring understory angiosperm species from a montane Hawaiian rainforest. We found higher instantaneous and lifetime (corrected for leaf lifespan) transpiration rates in angiosperms relative to ferns. Ferns preferentially incorporated Ca into leaves relative to strontium, which suggests that root or stem cation exchange capacity differs between ferns and angiosperms, potentially affecting calcium transport in plants. There were no differences in foliar Ca leaching loss between groups. Among the physiological mechanisms measured, foliar Ca was most strongly correlated with leaf-level transpiration rate and leaf lifespan. This suggests that inter-specific differences in a leaf's lifetime transpiration may play a significant role in determining plant nutrition.

  18. 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

  19. 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

  20. 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

  1. Do quantitative vessel and pit characters account for ion-mediated changes in the hydraulic conductance of angiosperm xylem?

    NARCIS (Netherlands)

    Jansen, S.; Gortan, E.; Lens, F.; Assunta Lo Gullo, M.; Salleo, S.; Scholtz, A.; Stein, A.; Trifilò, P.; Nardini, A.

    2011-01-01

    • The hydraulic conductance of angiosperm xylem has been suggested to vary with changes in sap solute concentrations because of intervessel pit properties. • The magnitude of the ‘ionic effect’ was linked with vessel and pit dimensions in 20 angiosperm species covering 13 families including six Laur

  2. Molecular data from the chloroplast rpoC1 gene suggest a deep and distinct dichotomy of contemporary spermatophytes into two monophyla: gymnosperms (including Gnetales) and angiosperms.

    Science.gov (United States)

    Samigullin, T K; Martin, W F; Troitsky, A V; Antonov, A S

    1999-09-01

    Partial sequences of the rpoC1 gene from two species of angiosperms and three species of gymnosperms (8330 base pairs) were determined and compared. The data obtained support the hypothesis that angiosperms and gymnosperms are monophyletic and none of the recent groups of the latter is sister to angiosperms.

  3. Seed Size and Dispersal Systems of Early Cretaceous Angiosperms from Famalicão, Portugal.

    Science.gov (United States)

    Eriksson; Friis; Pedersen; Crane

    2000-03-01

    Seeds and fruits of Early Cretaceous (Barremian-Aptian) angiosperms from the Famalicão locality in Portugal were analyzed to establish seed and fruit size (volume) distributions and to infer the proportion of animal-dispersed fruits. On the basis of a sample of 106 angiosperm fruit and seed taxa, the average seed size was 0.78 mm3 (range 0.02-6.86 mm3), whereas the average fruit size was 2.06 mm3 (range 0.12-8.34 mm3). Variation in seed size among taxa is smaller than in modern plant communities, but within-taxon variation is similar to that known for extant plants. No significant difference in the size of "fleshy" versus other fruits was observed. The proportion of fleshy fruits was 24.5%. This high figure was surprising and indicates that the significance of animal dispersal during an early stage in angiosperm evolution has been underestimated. We suggest that reptiles and multituberculates, and perhaps other mammals and birds as well, were the likely seed dispersers and that the early angiosperms from Famalicão probably were herbs or small shrubs that inhabited a semiopen coniferous woodland.

  4. Nested radiations and the pulse of angiosperm diversification: increased diversification rates often follow whole genome duplications.

    Science.gov (United States)

    Tank, David C; Eastman, Jonathan M; Pennell, Matthew W; Soltis, Pamela S; Soltis, Douglas E; Hinchliff, Cody E; Brown, Joseph W; Sessa, Emily B; Harmon, Luke J

    2015-07-01

    Our growing understanding of the plant tree of life provides a novel opportunity to uncover the major drivers of angiosperm diversity. Using a time-calibrated phylogeny, we characterized hot and cold spots of lineage diversification across the angiosperm tree of life by modeling evolutionary diversification using stepwise AIC (MEDUSA). We also tested the whole-genome duplication (WGD) radiation lag-time model, which postulates that increases in diversification tend to lag behind established WGD events. Diversification rates have been incredibly heterogeneous throughout the evolutionary history of angiosperms and reveal a pattern of 'nested radiations' - increases in net diversification nested within other radiations. This pattern in turn generates a negative relationship between clade age and diversity across both families and orders. We suggest that stochastically changing diversification rates across the phylogeny explain these patterns. Finally, we demonstrate significant statistical support for the WGD radiation lag-time model. Across angiosperms, nested shifts in diversification led to an overall increasing rate of net diversification and declining relative extinction rates through time. These diversification shifts are only rarely perfectly associated with WGD events, but commonly follow them after a lag period.

  5. 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.

  6. Genetic enablers underlying the clustered evolutionary origins of C4 photosynthesis in angiosperms.

    Science.gov (United States)

    Christin, Pascal-Antoine; Arakaki, Mónica; Osborne, Colin P; Edwards, Erika J

    2015-04-01

    The evolutionary accessibility of novel adaptations varies among lineages, depending in part on the genetic elements present in each group. However, the factors determining the evolutionary potential of closely related genes remain largely unknown. In plants, CO2-concentrating mechanisms such as C4 and crassulacean acid metabolism (CAM) photosynthesis have evolved numerous times in distantly related groups of species, and constitute excellent systems to study constraints and enablers of evolution. It has been previously shown for multiple proteins that grasses preferentially co-opted the same gene lineage for C4 photosynthesis, when multiple copies were present. In this work, we use comparative transcriptomics to show that this bias also exists within Caryophyllales, a distantly related group with multiple C4 origins. However, the bias is not the same as in grasses and, when all angiosperms are considered jointly, the number of distinct gene lineages co-opted is not smaller than that expected by chance. These results show that most gene lineages present in the common ancestor of monocots and eudicots produced gene descendants that were recruited into C4 photosynthesis, but that C4-suitability changed during the diversification of angiosperms. When selective pressures drove C4 evolution, some copies were preferentially co-opted, probably because they already possessed C4-like expression patterns. However, the identity of these C4-suitable genes varies among clades of angiosperms, and C4 phenotypes in distant angiosperm groups thus represent genuinely independent realizations, based on different genetic precursors.

  7. The angiosperm radiation revisited, an ecological explanation for Darwin's 'abominable mystery'

    NARCIS (Netherlands)

    Berendse, F.; Scheffer, M.

    2009-01-01

    One of the greatest terrestrial radiations is the diversification of the flowering plants (Angiospermae) in the Cretaceous period. Early angiosperms appear to have been limited to disturbed, aquatic or extremely dry sites, suggesting that they were suppressed in most other places by the gymnosperms

  8. 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

  9. Additions of angiosperms to the Flora of Peru from the Andean-Amazonian forests of southern Peru

    Directory of Open Access Journals (Sweden)

    Isau Huamantupa

    2014-10-01

    Full Text Available We present 25 new records of angiosperms for the Peruvian flora, as a result of different botanical explorations conducted in southern Peru, mainly in the areas of the departments of Cusco, Apurimac and Madre de Dios.

  10. 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.

  11. 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...

  12. New taxa of angiosperms from coal-bearing continental deposits in Amur area

    Institute of Scientific and Technical Information of China (English)

    Tat'yana V. KEZINA

    2008-01-01

    Considered the question about stratigraphic position of coal-beating continental deposits of the Amur area, the main attention is paid to the definition of pollen of angiosperms. Khlonova (1960), Zaklinskaya (1963), Bratseva (1969) and other scientists reported a lot about the significance of the pollen. Among the new taxa the special interest represents the first description of Engelhardtia pollen of late Maestrichtian and Paleocene deposits. A new kind of pollen Vacuopollis triplicatus sp. nov. is described.

  13. New Caledonia : a Pleistocene refugium for rain forest lineages of relict angiosperms

    OpenAIRE

    Pouteau, Robin; Trueba, S.; Feild, T.S.; Isnard, Sandrine

    2015-01-01

    Aim In New Caledonia, relictual angiosperm lineages are over-represented. However, the mechanisms responsible for such a distribution remain unclear. Two key hypotheses are that: (1) the diversity reflects adaptation to ultramafic substrates that ecologically filtered plant colonists; and (2) the diversity stems from wet climatic conditions that have persisted in New Caledonia during the late Quaternary while Australia and some nearby islands experienced widespread extinction events. Here, we...

  14. 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...

  15. 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

  16. The tracheid-vessel element transition in angiosperms involves multiple independent features: cladistic consequences.

    Science.gov (United States)

    Carlquist, Sherwin; Schneider, Edward L

    2002-02-01

    Current definitions of tracheids and vessel elements are overly simple. These definitions are based on light microscope studies and have not incorporated information gained with scanning electron microscopy (SEM) or transmission electron microscopy (TEM). Current definitions are based primarily on angiosperms, especially eudicots, and were devised before many basal angiosperms were carefully studied. When all sources of information are taken into account, one can recognize changes in six characters in the evolution of tracheids into vessel elements in angiosperms (or vice versa) as well as in other groups of vascular plants. There is an appreciable number of taxa in which all criteria for vessel origin are not met, and thus incipient vessels are present. At the very least, vessel presence or absence should not be treated as a single binary character state change in construction of cladistic matrices. Increase in conductive area of an end wall by means of lysis of progressively greater areas of pit membrane and increase in pit area on the end wall (as compared to pit area on equivalent portions of lateral walls) are considered the most important usable criteria for recognizing intermediacy between tracheids and vessel elements. Primitive character states in vessel elements are briefly discussed to differentiate them from changes in character states that can be regarded as intermediate between tracheids and vessel elements.

  17. 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

  18. 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.

  19. The rise of angiosperm-dominated herbaceous floras: Insights from Ranunculaceae.

    Science.gov (United States)

    Wang, Wei; Lin, Li; Xiang, Xiao-Guo; Ortiz, Rosa Del C; Liu, Yang; Xiang, Kun-Li; Yu, Sheng-Xiang; Xing, Yao-Wu; Chen, Zhi-Duan

    2016-01-01

    The rise of angiosperms has been regarded as a trigger for the Cretaceous revolution of terrestrial ecosystems. However, the timeframe of the rise angiosperm-dominated herbaceous floras (ADHFs) is lacking. Here, we used the buttercup family (Ranunculaceae) as a proxy to provide insights into the rise of ADHFs. An integration of phylogenetic, molecular dating, ancestral state inferring, and diversification analytical methods was used to infer the early evolutionary history of Ranunculaceae. We found that Ranunculaceae became differentiated in forests between about 108-90 Ma. Diversification rates markedly elevated during the Campanian, mainly resulted from the rapid divergence of the non-forest lineages, but did not change across the Cretaceous-Paleogene boundary. Our data for Ranunculaceae indicate that forest-dwelling ADHFs may have appeared almost simultaneously with angiosperm-dominated forests during the mid-Cretaceous, whereas non-forest ADHFs arose later, by the end of the Cretaceous terrestrial revolution. Furthermore, ADHFs were relatively unaffected by the Cretaceous-Paleogene mass extinction. PMID:27251635

  20. Diffusional limitations explain the lower photosynthetic capacity of ferns as compared with angiosperms in a common garden study.

    Science.gov (United States)

    Carriquí, M; Cabrera, H M; Conesa, M À; Coopman, R E; Douthe, C; Gago, J; Gallé, A; Galmés, J; Ribas-Carbo, M; Tomás, M; Flexas, J

    2015-03-01

    Ferns are thought to have lower photosynthetic rates than angiosperms and they lack fine stomatal regulation. However, no study has directly compared photosynthesis in plants of both groups grown under optimal conditions in a common environment. We present a common garden comparison of seven angiosperms and seven ferns paired by habitat preference, with the aims of (1) confirming that ferns do have lower photosynthesis capacity than angiosperms and quantifying these differences; (2) determining the importance of diffusional versus biochemical limitations; and (3) analysing the potential implication of leaf anatomical traits in setting the photosynthesis capacity in both groups. On average, the photosynthetic rate of ferns was about half that of angiosperms, and they exhibited lower stomatal and mesophyll conductance to CO2 (gm ), maximum velocity of carboxylation and electron transport rate. A quantitative limitation analysis revealed that stomatal and mesophyll conductances were co-responsible for the lower photosynthesis of ferns as compared with angiosperms. However, gm alone was the most constraining factor for photosynthesis in ferns. Consistently, leaf anatomy showed important differences between angiosperms and ferns, especially in cell wall thickness and the surface of chloroplasts exposed to intercellular air spaces.

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. Evolution of a unique anatomical precision in angiosperm leaf venation lifts constraints on vascular plant ecology.

    Science.gov (United States)

    Zwieniecki, Maciej A; Boyce, Charles K

    2014-03-22

    The main role of leaf venation is to supply water across the photosynthetic surface to keep stomata open and allow access to atmospheric CO2 despite evaporative demand. The optimal uniform delivery of water occurs when the distance between veins equals the depth of vein placement within the leaf away from the evaporative surface. As presented here, only angiosperms maintain this anatomical optimum across all leaf thicknesses and different habitats, including sheltered environments where this optimization need not be required. Intriguingly, basal angiosperm lineages tend to be underinvested hydraulically; uniformly high optimization is derived independently in the magnoliids, monocots and core eudicots. Gymnosperms and ferns, including available fossils, are limited by their inability to produce high vein densities. The common association of ferns with shaded humid environments may, in part, be a direct evolutionary consequence of their inability to produce hydraulically optimized leaves. Some gymnosperms do approach optimal vein placement, but only by virtue of their ability to produce thick leaves most appropriate in environments requiring water conservation. Thus, this simple anatomical metric presents an important perspective on the evolution and phylogenetic distribution of plant ecologies and further evidence that the vegetative biology of flowering plants-not just their reproductive biology-is unique.

  9. Non-equilibrium dynamics and floral trait interactions shape extant angiosperm diversity.

    Science.gov (United States)

    O'Meara, Brian C; Smith, Stacey D; Armbruster, W Scott; Harder, Lawrence D; Hardy, Christopher R; Hileman, Lena C; Hufford, Larry; Litt, Amy; Magallón, Susana; Smith, Stephen A; Stevens, Peter F; Fenster, Charles B; Diggle, Pamela K

    2016-05-11

    Why are some traits and trait combinations exceptionally common across the tree of life, whereas others are vanishingly rare? The distribution of trait diversity across a clade at any time depends on the ancestral state of the clade, the rate at which new phenotypes evolve, the differences in speciation and extinction rates across lineages, and whether an equilibrium has been reached. Here we examine the role of transition rates, differential diversification (speciation minus extinction) and non-equilibrium dynamics on the evolutionary history of angiosperms, a clade well known for the abundance of some trait combinations and the rarity of others. Our analysis reveals that three character states (corolla present, bilateral symmetry, reduced stamen number) act synergistically as a key innovation, doubling diversification rates for lineages in which this combination occurs. However, this combination is currently less common than predicted at equilibrium because the individual characters evolve infrequently. Simulations suggest that angiosperms will remain far from the equilibrium frequencies of character states well into the future. Such non-equilibrium dynamics may be common when major innovations evolve rarely, allowing lineages with ancestral forms to persist, and even outnumber those with diversification-enhancing states, for tens of millions of years. PMID:27147092

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

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    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.

  11. Conservation and canalization of gene expression during angiosperm diversification accompany the origin and evolution of the flower.

    Science.gov (United States)

    Chanderbali, André S; Yoo, Mi-Jeong; Zahn, Laura M; Brockington, Samuel F; Wall, P Kerr; Gitzendanner, Matthew A; Albert, Victor A; Leebens-Mack, James; Altman, Naomi S; Ma, Hong; dePamphilis, Claude W; Soltis, Douglas E; Soltis, Pamela S

    2010-12-28

    The origin and rapid diversification of the angiosperms (Darwin's "Abominable Mystery") has engaged generations of researchers. Here, we examine the floral genetic programs of phylogenetically pivotal angiosperms (water lily, avocado, California poppy, and Arabidopsis) and a nonflowering seed plant (a cycad) to obtain insight into the origin and subsequent evolution of the flower. Transcriptional cascades with broadly overlapping spatial domains, resembling the hypothesized ancestral gymnosperm program, are deployed across morphologically intergrading organs in water lily and avocado flowers. In contrast, spatially discrete transcriptional programs in distinct floral organs characterize the more recently derived angiosperm lineages represented by California poppy and Arabidopsis. Deep evolutionary conservation in the genetic programs of putatively homologous floral organs traces to those operating in gymnosperm reproductive cones. Female gymnosperm cones and angiosperm carpels share conserved genetic features, which may be associated with the ovule developmental program common to both organs. However, male gymnosperm cones share genetic features with both perianth (sterile attractive and protective) organs and stamens, supporting the evolutionary origin of the floral perianth from the male genetic program of seed plants.

  12. Weak coordination among petiole, leaf, vein, and gas-exchange traits across 41 Australian angiosperm species and its possible implications

    Science.gov (United States)

    Background and Aims Close coordination between leaf gas exchange and maximal hydraulic supply has been reported across diverse plant life-forms. However, recent reports suggest that this relationship may become weak or break down completely within the angiosperms. Methods To examine this possi...

  13. 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...... production in bicultures in general, while a positive net effect was found in the P. perfoliatus and P. filiformis biculture. Despite the absence of significant results for other treatments and plant variables, a trend of positive complementarity and negative selection effects were present. Plant diversity......Research on plant biodiversity and ecosystem functioning has mainly focused on terrestrial ecosystems, and our understanding of how plant species diversity and interactions affect processes in marine ecosystems is still limited. To investigate if plant species richness and composition influence...

  14. Uneven HAK/KUP/KT protein diversity among angiosperms: species distribution and perspectives

    Directory of Open Access Journals (Sweden)

    Manuel eNieves-Cordones

    2016-02-01

    Full Text Available HAK/KUP/KT K+ transporters have been widely associated with K+ transport across membranes in bacteria, fungi and plants. Indeed some members of the plant HAK/KUP/KT family contribute to root K+ uptake, notably at low external concentrations. Besides such role in acquisition, several studies carried out in Arabidopsis have shown that other members are also involved in developmental processes. With the publication of new plant genomes, a growing interest on plant species other than Arabidopsis has become evident. In order to understand HAK/KUP/KT diversity in these new plant genomes, we discuss the evolutionary trends of 913 HAK/KUP/KT sequences identified in 46 genomes revealing five major groups with an uneven distribution among angiosperms, notably between dicotyledonous and monocotyledonous species. This information evidenced the richness of crop genomes in HAK/KUP/KT transporters and supports their study for unraveling novel physiological roles of such transporters in plants.

  15. Gymnosperms have increased capacity for electron leakage to oxygen (Mehler and PTOX reactions) in photosynthesis compared with angiosperms.

    Science.gov (United States)

    Shirao, Masayoshi; Kuroki, Shu; Kaneko, Kaoru; Kinjo, Yuriko; Tsuyama, Michito; Förster, Britta; Takahashi, Shunichi; Badger, Murray R

    2013-07-01

    Oxygen plays an important role in photosynthesis by participating in a number of O2-consuming reactions. O2 inhibits CO2 fixation by stimulating photorespiration, thus reducing plant production. O2 interacts with photosynthetic electron transport in the chloroplasts' thylakoids in two main ways: by accepting electrons from PSI (Mehler reaction); and by accepting electrons from reduced plastoquinone (PQ) mediated by the plastid terminal oxidase (PTOX). In this study, we show, using 101 plant species, that there is a difference in the potential for photosynthetic electron flow to O2 between angiosperms and gymnosperms. We found, from measurements of Chl fluorescence and leaf absorbance at 830 nm, (i) that electron outflow from PSII, as determined by decay kinetics of Chl fluorescence after application of a saturating light pulse, is more rapid in gymnosperms than in angiosperms; (ii) that the reaction center Chl of PSI (P700) is rapidly and highly oxidized in gymnosperms during induction of photosynthesis; and (iii) that these differences are dependent on oxygen. Finally, rates of O2 uptake measured by mass spectrometry in the absence of photorespiration were significantly promoted by illumination in dark-adapted leaves of gymnosperms, but not in those of angiosperms. The light-stimulated O2 uptake was around 10% of the maximum O2 evolution in gymnosperms and 1% in angiosperms. These results suggest that gymnosperms have increased capacity for electron leakage to oxygen in photosynthesis compared with angiosperms. The involvement of the Mehler reaction and PTOX in the electron flow to O2 is discussed.

  16. 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

  17. 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.

  18. 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.

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

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    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.

  20. 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

  1. 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

  2. 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

  3. Bark ecology of twigs vs. main stems: functional traits across eighty-five species of angiosperms.

    Science.gov (United States)

    Rosell, Julieta A; Castorena, Matiss; Laws, Claire A; Westoby, Mark

    2015-08-01

    Although produced by meristems that are continuous along the stem length, marked differences in bark morphology and in microenvironment would suggest that main stem and twig bark might differ ecologically. Here, we examined: (1) how closely associated main stem and twig bark traits were, (2) how these associations varied across sites, and (3) used these associations to infer functional and ecological differences between twig and main stem bark. We measured density, water content, photosynthesis presence/absence, total, outer, inner, and relative thicknesses of main stem and twig bark from 85 species of angiosperms from six sites of contrasting precipitation, temperature, and fire regimes. Density and water content did not differ between main stems and twigs across species and sites. Species with thicker twig bark had disproportionately thicker main stem bark in most sites, but the slope and degree of association varied. Disproportionately thicker main stem bark for a given twig bark thickness in most fire-prone sites suggested stem protection near the ground. The savanna had the opposite trend, suggesting that selection also favors twig protection in these fire-prone habitats. A weak main stem-twig bark thickness association was observed in non fire-prone sites. The near-ubiquity of photosynthesis in twigs highlighted its likely ecological importance; variation in this activity was predicted by outer bark thickness in main stems. It seems that the ecology of twig bark can be generalized to main stem bark, but not for functions depending on the amount of bark, such as protection, storage, or photosynthesis.

  4. A test of the hydraulic vulnerability segmentation hypothesis in angiosperm and conifer tree species.

    Science.gov (United States)

    Johnson, Daniel M; Wortemann, Remi; McCulloh, Katherine A; Jordan-Meille, Lionel; Ward, Eric; Warren, Jeffrey M; Palmroth, Sari; Domec, Jean-Christophe

    2016-08-01

    Water transport from soils to the atmosphere is critical for plant growth and survival. However, we have a limited understanding about many portions of the whole-tree hydraulic pathway, because the vast majority of published information is on terminal branches. Our understanding of mature tree trunk hydraulic physiology, in particular, is limited. The hydraulic vulnerability segmentation hypothesis (HVSH) stipulates that distal portions of the plant (leaves, branches and roots) should be more vulnerable to embolism than trunks, which are nonredundant organs that require a massive carbon investment. In the current study, we compared vulnerability to loss of hydraulic function, leaf and xylem water potentials and the resulting hydraulic safety margins (in relation to the water potential causing 50% loss of hydraulic conductivity) in leaves, branches, trunks and roots of four angiosperms and four conifer tree species. Across all species, our results supported strongly the HVSH as leaves and roots were less resistant to embolism than branches or trunks. However, branches were consistently more resistant to embolism than any other portion of the plant, including trunks. Also, calculated whole-tree vulnerability to hydraulic dysfunction was much greater than vulnerability in branches. This was due to hydraulic dysfunction in roots and leaves at less negative water potentials than those causing branch or trunk dysfunction. Leaves and roots had narrow or negative hydraulic safety margins, but trunks and branches maintained positive safety margins. By using branch-based hydraulic information as a proxy for entire plants, much research has potentially overestimated embolism resistance, and possibly drought tolerance, for many species. This study highlights the necessity to reconsider past conclusions made about plant resistance to drought based on branch xylem only. This study also highlights the necessity for more research of whole-plant hydraulic physiology to better

  5. A test of the hydraulic vulnerability segmentation hypothesis in angiosperm and conifer tree species.

    Science.gov (United States)

    Johnson, Daniel M; Wortemann, Remi; McCulloh, Katherine A; Jordan-Meille, Lionel; Ward, Eric; Warren, Jeffrey M; Palmroth, Sari; Domec, Jean-Christophe

    2016-08-01

    Water transport from soils to the atmosphere is critical for plant growth and survival. However, we have a limited understanding about many portions of the whole-tree hydraulic pathway, because the vast majority of published information is on terminal branches. Our understanding of mature tree trunk hydraulic physiology, in particular, is limited. The hydraulic vulnerability segmentation hypothesis (HVSH) stipulates that distal portions of the plant (leaves, branches and roots) should be more vulnerable to embolism than trunks, which are nonredundant organs that require a massive carbon investment. In the current study, we compared vulnerability to loss of hydraulic function, leaf and xylem water potentials and the resulting hydraulic safety margins (in relation to the water potential causing 50% loss of hydraulic conductivity) in leaves, branches, trunks and roots of four angiosperms and four conifer tree species. Across all species, our results supported strongly the HVSH as leaves and roots were less resistant to embolism than branches or trunks. However, branches were consistently more resistant to embolism than any other portion of the plant, including trunks. Also, calculated whole-tree vulnerability to hydraulic dysfunction was much greater than vulnerability in branches. This was due to hydraulic dysfunction in roots and leaves at less negative water potentials than those causing branch or trunk dysfunction. Leaves and roots had narrow or negative hydraulic safety margins, but trunks and branches maintained positive safety margins. By using branch-based hydraulic information as a proxy for entire plants, much research has potentially overestimated embolism resistance, and possibly drought tolerance, for many species. This study highlights the necessity to reconsider past conclusions made about plant resistance to drought based on branch xylem only. This study also highlights the necessity for more research of whole-plant hydraulic physiology to better

  6. 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.

  7. 侏罗纪的花化石与被子植物起源%Jurassic flower fossils and the origin of angiosperms

    Institute of Scientific and Technical Information of China (English)

    王鑫; 刘仲健

    2015-01-01

    理解被子植物的历史对于人们了解现代被子植物之间的关系十分重要。以前欧美古植物学家认为,被子植物的历史不会早于白垩纪,使得被子植物看起来似乎是在白垩纪早期突然爆发的。但是分子钟和系统分析显示,被子植物应当早在三叠纪,至少在侏罗纪就已经出现了,但是问题的关键是相应化石证据的缺失。因此侏罗纪的花化石成为解决两个学派之间争斗的关键证据。本文简要地介绍了产出于中国辽西同一地层的、侏罗纪的三个被子植物属种及其特征,确认了被子植物在侏罗纪的存在,提出了新的被子植物雌蕊同源性理论,并为下一步植物系统学的发展打下了坚实的基础。%Understanding on the history of angiosperms is hinged with our appreciation of the relationship among extant angiosperms. Formerly European and American palaeobotanists believed that angiosperms cannot be older than the Cretaceous, leaving the origin of angiosperms as if a sudden explosion during the Early Cretaceous. But molecular clock and systematic analysis suggested that angiosperms should have been in place in the Triassic or at least the Jurassic, but this point of view lacked fossil support. Therefore the fates of angiosperm evolution hypotheses are hinged with the existence of fossilflowers in the Jurassic. Herein we introduce three taxa of angiosperms from a single Jurassic fossil locality in western Liaoning, China, confirming the existence of angiosperms in the Jurassic, advancing a new theory on the homology of angiosperm gynoecium, and paving the road for further development of plant systematics.

  8. Phylogenetic assemblage structure of North American trees is more strongly shaped by glacial-interglacial climate variability in gymnosperms than in angiosperms.

    Science.gov (United States)

    Ma, Ziyu; Sandel, Brody; Svenning, Jens-Christian

    2016-05-01

    How fast does biodiversity respond to climate change? The relationship of past and current climate with phylogenetic assemblage structure helps us to understand this question. Studies of angiosperm tree diversity in North America have already suggested effects of current water-energy balance and tropical niche conservatism. However, the role of glacial-interglacial climate variability remains to be determined, and little is known about any of these relationships for gymnosperms. Moreover, phylogenetic endemism, the concentration of unique lineages in restricted ranges, may also be related to glacial-interglacial climate variability and needs more attention. We used a refined phylogeny of both angiosperms and gymnosperms to map phylogenetic diversity, clustering and endemism of North American trees in 100-km grid cells, and climate change velocity since Last Glacial Maximum together with postglacial accessibility to recolonization to quantify glacial-interglacial climate variability. We found: (1) Current climate is the dominant factor explaining the overall patterns, with more clustered angiosperm assemblages toward lower temperature, consistent with tropical niche conservatism. (2) Long-term climate stability is associated with higher angiosperm endemism, while higher postglacial accessibility is linked to to more phylogenetic clustering and endemism in gymnosperms. (3) Factors linked to glacial-interglacial climate change have stronger effects on gymnosperms than on angiosperms. These results suggest that paleoclimate legacies supplement current climate in shaping phylogenetic patterns in North American trees, and especially so for gymnosperms.

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  11. Primary productivity of angiosperm and macroalgae dominated habitats in a New England Salt Marsh: a Comparative analysis

    Science.gov (United States)

    Roman, C. T.; Able, K. W.; Lazzari, M. A.; Heck, K. L.

    1990-01-01

    Net primary productivity estimates were made for the major macrophyte dominated habitats of the Nauset Marsh system, Cape Cod, Massachusetts. Above-ground primary productivity of short form Spartina alterniflora, the dominant habitat of the system, was 664 g m -2 y -1. Productivity of the other dominant angiosperm ( Zostera marina) was estimated to range from 444-987 g m -2 y -1. The marsh creekbank habitat was dominated by an intertidal zone of fucoid algae ( Ascophyllum nodosum ecad. scorpioides, 1179 g m -2 y -1; Fucus vesiculosus, 426 g m -2 y -1), mixed intertidal filamentous algae (91 g m -2 y -1), and a subtidal zone of assorted macroalgae (68 g m -2 y -1). Intertidal mudflats were dominated by Cladophora gracilis, with net production ranging from 59-637 g m -2 y -1. These angiosperm and macrophyte and macrophyte dominated habitats produce over 3 × 10 6 kg y -1 of biomass (1·2 × 10 6 kg carbon y -1). Twenty-eight per cent (28%) of this carbon production is derived from the Zostera and macroalgae habitats. Although S. alterniflora is considered the major macrophyte primary producer in Nauset Marsh and other north temperate salt marshes, it is concluded that other habitats also contribute significantly to total system carbon production.

  12. 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.

  13. Global DNA cytosine methylation as an evolving trait: phylogenetic signal and correlated evolution with genome size in Angiosperms

    Directory of Open Access Journals (Sweden)

    Conchita eAlonso

    2015-01-01

    Full Text Available DNA cytosine methylation is a widespread epigenetic mechanism in eukaryotes, and plant genomes commonly are densely methylated. Genomic methylation can be associated with functional consequences such as mutational events, genomic instability or altered gene expression, but little is known on interspecific variation in global cytosine methylation in plants. In this paper, we compare global cytosine methylation estimates obtained by HPLC and use a phylogenetically-informed analytical approach to test for significance of evolutionary signatures of this trait across 54 angiosperm species in 25 families. We evaluate whether interspecific variation in global cytosine methylation is statistically related to phylogenetic distance and also whether it is evolutionarily correlated with genome size (C-value. Global cytosine methylation varied widely between species, ranging between 5.3% (Arabidopsis and 39.2% (Narcissus. Differences between species were related to their evolutionary trajectories, as denoted by the strong phylogenetic signal underlying interspecific variation. Global cytosine methylation and genome size were evolutionarily correlated, as revealed by the significant relationship between the corresponding phylogenetically independent contrasts. On average, a ten-fold increase in genome size entailed an increase of about 10% in global cytosine methylation. Results show that global cytosine methylation is an evolving trait in angiosperms whose evolutionary trajectory is significantly linked to changes in genome size, and suggest that the evolutionary implications of epigenetic mechanisms are likely to vary between plant lineages.

  14. Phylogenetic assemblage structure of North American trees is more strongly shaped by glacial–interglacial climate variability in gymnosperms than in angiosperms

    DEFF Research Database (Denmark)

    Ma, Ziyu; Sandel, Brody Steven; Svenning, Jens-Christian

    How fast does biodiversity respond to climate change? The relationship of past and current climate with phylogenetic assemblage structure helps us to understand this question. Studies of angiosperm tree diversity in North America have already suggested effects of current water-energy balance......-interglacial climate variability and needs more attention. We used a refined phylogeny of both angiosperms and gymnosperms to map phylogenetic diversity, clustering and endemism of North American trees in 100-km grid cells, and climate change velocity since Last Glacial Maximum together with postglacial accessibility...... that paleoclimate legacies supplement current climate in shaping phylogenetic patterns in North American trees, and especially so for gymnosperms....

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

    Directory of Open Access Journals (Sweden)

    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

  16. 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

  17. 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...

  18. 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

  19. 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

    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...... and processes that require further research. Relatively larger amounts of nutrients enter the soil-plant biogeochemical cycle under the influence of EGs than DAs, but recycling of nutrients appears to be slightly enhanced by DAs. Understanding the mechanisms underlying forest ecosystem functioning is essential...... 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...

  20. Noncoding sequences from the slowly evolving chloroplast inverted repeat in addition to rbcL data do not support gnetalean affinities of angiosperms.

    Science.gov (United States)

    Goremykin, V; Bobrova, V; Pahnke, J; Troitsky, A; Antonov, A; Martin, W

    1996-02-01

    We developed PCR primers against highly conserved regions of the rRNA operon located within the inverted repeat of the chloroplast genome and used these to amplify the region spanning from the 3' terminus of the 23S rRNA gene to the 5' terminus of the 5S rRNA gene. The sequence of this roughly 500-bp region, which includes the 4.5S rRNA gene and two chloroplast intergenic transcribed spacer regions (cpITS2 and cpITS3), was determined from 20 angiosperms, 7 gymnosperms, and 16 ferns (21,700 bp). Sequences for the large subunit of ribulose bisphosphate carboxylase/oxygenase (rbcL) from the same or confamilial genera were analyzed in both separate and combined data sets. Due to the low substitution rate in the inverted repeat region, noncoding sequences in the cpITS region are not saturated with substitutions, in contrast to synonymous sites in rbcL, which are shown to evolve roughly six times faster than noncoding cpITS sequences. Several length polymorphisms with very clear phylogenetic distributions were detected in the data set. Results of phylogenetic analyses provide very strong bootstrap support for monophyly of both spermatophytes and angiosperms. No support for a sister group relationship between Gnetales and angiosperms in either cpITS or rbcL data was found. Rather, weak bootstrap support for monophyly of gymnosperms studied and for a basal position for the aquatic angiosperm Nymphaea among angiosperms studied was observed. Noncoding sequences from the inverted repeat region of chloroplast DNA appear suitable for study of land plant evolution.

  1. 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.

  2. Early Angiosperm Flowers and Angiosperm Evolution

    DEFF Research Database (Denmark)

    Friis, Else Marie; Pedersen, Kaj Raunsgaard

    2015-01-01

    Boletim de Resumos XXIV Congresso Brasileiro de Paleontologia pp43 Paleontoiogi em Destaque Edicao especial-Agosto,2015......Boletim de Resumos XXIV Congresso Brasileiro de Paleontologia pp43 Paleontoiogi em Destaque Edicao especial-Agosto,2015...

  3. Conservation of the abscission signaling peptide IDA during Angiosperm evolution: withstanding genome duplications and gain and loss of the receptors HAE/HSL2

    Directory of Open Access Journals (Sweden)

    Ida M. Stø

    2015-10-01

    Full Text Available The peptide INFLORESCENCE DEFICIENT IN ABSCISSION (IDA, which signals through the leucine-rich repeat receptor-like kinases HAESA (HAE and HAESA-LIKE2 (HSL2, controls different cell separation events in Arabidopsis thaliana. We hypothesize the involvement of this signaling module in abscission processes in other plant species even though they may shed other organs than A. thaliana. As the first step towards testing this hypothesis from an evolutionarily perspective we have identified genes encoding putative orthologues of IDA and its receptors by BLAST searches of publically available protein, nucleotide and genome databases for angiosperms. Genes encoding IDA or IDA-LIKE (IDL peptides and HSL proteins were found in all investigated species, which were selected as to represent each angiosperm order with available genomic sequences. The 12 amino acids representing the bioactive peptide in A. thaliana have virtually been unchanged throughout the evolution of the angiosperms; however, the number of IDL and HSL genes varies between different orders and species. The phylogenetic analyses suggest that IDA, HSL2 and the related HSL1 gene, were present in the species that gave rise to the angiosperms. HAE has arisen from HSL1 after a genome duplication that took place after the monocot - eudicots split. HSL1 has also independently been duplicated in the monocots, while HSL2 has been lost in gingers (Zingiberales and grasses (Poales. IDA has been duplicated in eudicots to give rise to functionally divergent IDL peptides. We postulate that the high number of IDL homologs present in the core eudicots is a result of multiple whole genome duplications. We substantiate the involvement of IDA and HAE/HSL2 homologs in abscission by providing gene expression data of different organ separation events from various species.

  4. New Records of Angiosperm from Inner Mongolia, China%内蒙古被子植物分布新资料

    Institute of Scientific and Technical Information of China (English)

    赵利清; 王乐; 包萨如拉; 庞哲

    2012-01-01

    报道了内蒙古1个新分布记录属:粟草属(Milium L.);2个新分布记录种:翅柄车前(Plantago komarovii Pavl.)和粟草(Milium effusum L.).%New records of angiosperm taxa in Inner Mongolia are reported. Among those, Milium L. is a newly recorded genus,Plantago komarovii Pavl. and Milium effusum L. are two newly recorded species.

  5. 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.

  6. 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

  7. 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

  8. Perfume-collecting male euglossine bees as pollinators of a basal angiosperm: the case of Unonopsis stipitata (Annonaceae).

    Science.gov (United States)

    Teichert, H; Dötterl, S; Zimma, B; Ayasse, M; Gottsberger, G

    2009-01-01

    Pollination of Unonopsis stipitata (Annonaceae) by males of two perfume-collecting bees, Euglossa imperialis and Eulaema bombiformis (Euglossini) is described. This is the first detailed account of this pollination mode in a member of a basal angiosperm family. Pollinator behaviour, identification of the odour bouquet and electrophysiological reaction of one of the two pollinators to the odour bouquet were determined. The collected odour is produced by 'osmophores' located adaxially on the petals. Starch and polysaccharides accumulated in petals are metabolized during odour emission. Mainly monoterpenes were detected in the scent samples, among them trans-carvone oxide. This molecule is thought by several authors to be the key attractant for male Eulaema bees and may be pivotal for convergent evolution of the perfume-collecting syndrome among dicotyledonous and monocotyledonous plants. It is speculated that Unonopsis, which on the basis of molecular age dating is considered a relatively recent genus of the Annonaceae (being 15-30 million years old), has diversified in relation to male euglossine bee pollinators.

  9. Phylogeny of the basal angiosperm genus Pseuduvaria (Annonaceae) inferred from five chloroplast DNA regions, with interpretation of morphological character evolution.

    Science.gov (United States)

    Su, Yvonne C F; Smith, Gavin J D; Saunders, Richard M K

    2008-07-01

    Phylogenetic relationships within the magnoliid basal angiosperm genus Pseuduvaria (Annonaceae) are investigated using chloroplast DNA sequences from five regions: psbA-trnH spacer, trnL-F, matK, rbcL, and atpB-rbcL spacer. Over 4000 nucleotides from 51 species (of the total 53) were sequenced. The five cpDNA datasets were analyzed separately and in combination using maximum parsimony (MP), maximum likelihood (ML), and Bayesian methods. The phylogenetic trees constructed using all three phylogenetic methods, based on the combined data, strongly support the monophyly of Pseuduvaria following the inclusion of Craibella phuyensis. The trees generated using MP were less well resolved, but relationships are similar to those obtained using the other methods. ML and Bayesian analyses recovered trees with short branch lengths, showing five main clades. This study highlights the evolutionary changes in seven selected morphological characters (floral sex, stamen and carpel numbers, inner petal color, presence of inner petal glands, flowering peduncle length, and monocarp size). Although floral unisexuality is ancestral within the genus, several evolutionary lineages reveal reversal to bisexuality. Other phylogenetic transitions include the evolution of sapromyophily, and fruit-bat frugivory and seed dispersal, thus allowing a wide range of adaptations for species survival.

  10. 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

  11. 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.

  12. Phylogenetic relationships of the enigmatic angiosperm family Podostemaceae inferred from 18S rDNA and rbcL sequence data.

    Science.gov (United States)

    Soltis, D E; Mort, M E; Soltis, P S; Hibsch-Jetter, C; Zimmer, E A; Morgan, D

    1999-03-01

    The phylogenetic relationships of some angiosperm families have remained enigmatic despite broad phylogenetic analyses of rbcL sequences. One example is the aquatic family Podostemaceae, the relationships of which have long been controversial because of major morphological modifications associated with their aquatic habit. Podostemaceae have variously been associated with Piperaceae, Nepenthaceae, Polygonaceae, Caryophyllaceae, Scrophulariaceae, Rosaceae, Crassulaceae, and Saxifragaceae. Two recent analyses of rbcL sequences suggest a possible sister-group relationship of Podostemaceae to Crassulaceae (Saxifragales). However, the branch leading to Podostemaceae was long, and use of different outgroups resulted in alternative placements. We explored the phylogenetic relationships of Podostemaceae using 18S rDNA sequences and a combined rbcL + 18S rDNA matrix representing over 250 angiosperms. In analyses based on 18S rDNA data, Podostemaceae are not characterized by a long branch; the family consistently appears as part of a Malpighiales clade that also includes Malpighiaceae, Turneraceae, Passifloraceae, Salicaceae, Euphorbiaceae, Violaceae, Linaceae, Chrysobalanaceae, Trigoniaceae, Humiriaceae, and Ochnaceae. Phylogenetic analyses based on a combined 18S rDNA + rbcL data set (223 ingroup taxa) with basal angiosperms as the outgroup also suggest that Podostemaceae are part of a Malpighiales clade. These searches swapped to completion, and the shortest trees showed enhanced resolution and increased internal support compared to those based on 18S rDNA or rbcL alone. However, when Gnetales are used as the outgroup, Podostemaceae appear with members of the nitrogen fixing clade (e.g., Elaeagnaceae, Ulmaceae, Rhamnaceae, Cannabaceae, Moraceae, and Urticaceae). None of the relationships suggested here for Podostemaceae receives strong bootstrap support. Our analyses indicate that Podostemaceae are not closely allied with Crassulaceae or with other members of the

  13. Geranyllinalool Synthases in Solanaceae and Other Angiosperms Constitute an Ancient Branch of Diterpene Synthases Involved in the Synthesis of Defensive Compounds1[C][W][OPEN

    Science.gov (United States)

    Falara, Vasiliki; Alba, Juan M.; Kant, Merijn R.; Schuurink, Robert C.; Pichersky, Eran

    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 tomato (Solanum lycopersicum) TPS-e/f gene, TPS46, encoding GLS (SlGLS) and its homolog (NaGLS) from Nicotiana attenuata. The Km value of SlGLS for geranylgeranyl diphosphate was 18.7 µm, with a turnover rate value of 6.85 s–1. In leaves and flowers of N. attenuata, which constitutively synthesize 17-hydroxygeranyllinalool glycosides, NaGLS is expressed constitutively, but the gene can be induced in leaves with methyl jasmonate. In tomato, SlGLS is not expressed in any tissue under normal growth but is induced in leaves by alamethicin and methyl jasmonate treatments. SlGLS, NaGLS, AtGLSs, and several other GLSs characterized only in vitro come from four different eudicot families and constitute a separate branch of the TPS-e/f clade that diverged from kaurene synthases, also in the TPS-e/f clade, before the gymnosperm-angiosperm split. The early divergence of this branch and the GLS activity of genes in this branch in diverse eudicot families suggest that GLS activity encoded by these genes predates the angiosperm-gymnosperm split. However, although a TPS sequence belonging to this GLS lineage was recently reported from a basal dicot, no representative sequences have yet been found in monocot or nonangiospermous plants. PMID:25052853

  14. Slow but not low: genomic comparisons reveal slower evolutionary rate and higher dN/dS in conifers compared to angiosperms

    Directory of Open Access Journals (Sweden)

    Buschiazzo Emmanuel

    2012-01-01

    Full Text Available Background Comparative genomics can inform us about the processes of mutation and selection across diverse taxa. Among seed plants, gymnosperms have been lacking in genomic comparisons. Recent EST and full-length cDNA collections for two conifers, Sitka spruce (Picea sitchensis and loblolly pine (Pinus taeda, together with full genome sequences for two angiosperms, Arabidopsis thaliana and poplar (Populus trichocarpa, offer an opportunity to infer the evolutionary processes underlying thousands of orthologous protein-coding genes in gymnosperms compared with an angiosperm orthologue set. Results Based upon pairwise comparisons of 3,723 spruce and pine orthologues, we found an average synonymous genetic distance (dS of 0.191, and an average dN/dS ratio of 0.314. Using a fossil-established divergence time of 140 million years between spruce and pine, we extrapolated a nucleotide substitution rate of 0.68 × 10-9 synonymous substitutions per site per year. When compared to angiosperms, this indicates a dramatically slower rate of nucleotide substitution rates in conifers: on average 15-fold. Coincidentally, we found a three-fold higher dN/dS for the spruce-pine lineage compared to the poplar-Arabidopsis lineage. This joint occurrence of a slower evolutionary rate in conifers with higher dN/dS, and possibly positive selection, showcases the uniqueness of conifer genome evolution. Conclusions Our results are in line with documented reduced nucleotide diversity, conservative genome evolution and low rates of diversification in conifers on the one hand and numerous examples of local adaptation in conifers on the other hand. We propose that reduced levels of nucleotide mutation in large and long-lived conifer trees, coupled with large effective population size, were the main factors leading to slow substitution rates but retention of beneficial mutations.

  15. 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...

  16. Allelopathic effects of microcystin-LR on the germination, growth and metabolism of five charophyte species and a submerged angiosperm.

    Science.gov (United States)

    Rojo, Carmen; Segura, Matilde; Cortés, Francisco; Rodrigo, María A

    2013-11-15

    Microcystins (MCs) are produced by cyanobacteria in aquatic environments and adversely affect macrophytes at very high concentrations. However, the effects of MC on macrophytes at concentrations of environmental relevance are largely unknown. The main objective of this study was to analyze the allelopathic effects of MC-LR at natural concentrations (1, 8 and 16 μg MC-LR/L) on five charophyte species (Chara aspera, C. baltica, C. hispida, C. vulgaris and Nitella hyalina) and the angiosperm Myriophyllum spicatum. Macrophyte specimens were obtained from a restored area located in Albufera de València Natural Park, a protected coastal Mediterranean wetland. Two different experiments were conducted involving (i) the addition of MC-LR to natural sediment to evaluate its effects on seed germination and (ii) the addition of MC-LR to water cultures of macrophytes to evaluate its effects on growth and metabolic functions. In water, the MC-LR concentration decreased by 84% in two weeks; the loss was not significant in sediment. The first seedlings (all C. hispida) emerged from the wetland sediment following a delay of a few days in the presence of MC-LR. The germination rates in 8 and 16 μg MC-LR/L treatments were 44% and 11% of that occurring in the absence of MC, but these differences disappeared over time. The final density was 6-7 germlings/dm(3). Final germling length was unaffected by MC-LR. Rotifers (Lecane spp.) emerging from the natural sediment during the experiment were favored by MC-LR; the opposite pattern was observed in the cladoceran Daphnia magna. The growth rates of C. vulgaris, C. baltica and N. hyalina were unaffected by MC exposure, whereas those of C. hispida and C. aspera were reduced in the MC treatments relative to the control treatment. The concentration of chlorophyll-a and the in vivo net photosynthetic rate were lower in the presence of MC-LR, even at the lowest concentration, for all of the characeans tested. M. spicatum was sensitive to the

  17. Antioxidant, anticholinesterase and tyrosinase inhibition activities, and fatty acids of Crocus mathewii - A forgotten endemic angiosperm of Turkey.

    Science.gov (United States)

    Yildiztekin, Fatma; Nadeem, Said; Erol, Ebru; Yildiztekin, Mahmut; Tuna, Atilla L; Ozturk, Mehmet

    2016-09-01

    Context We report the first ever chemical/biochemical study on Crocus mathewii Kerndorff (Iridaceae) - a Turkish endemic angiosperm. This plant has never been explored for its phytochemistry and bioactivities. Objective This study explores C. mathewii corm and aerial parts for the chemical and biological properties of hexane, ethyl acetate, methanol and water fractions of the extracts. Material and methods Plant material (20 g) was extracted by methanol (250 mL × 5, 3 days each) and fractioned into hexane, ethyl acetate, methanol and water. All fractions were subjected to β-carotene-linoleic acid, DPPH(·), ABTS(·)(+), CUPRAC, metal chelating and tyrosinase inhibition activities. Hexane fractions were submitted to GC-MS analysis. Results Ethyl acetate fractions showed excellent IC50 values in DPPH(·) (aerial 36.21 ± 0.76 and corm 33.87 ± 0.02 mg/L) and ABTS(·)(+) (aerial 33.01 ± 0.79 and bulb 27.87 ± 0.33 mg/L); higher than the IC50 of the standard α-tocopherol (DPPH 116.25 ± 1.97; ABTS 52.64 ± 0.37 mg/L), higher than BHA in DPPH (57.31 ± 0.25 mg/L), but slightly lower in ABTS (19.86 ± 2.73 mg/L). Methanol extract of aerial parts also showed higher activity than α-tocopherol in DPPH (85.56 ± 11.51 mg/L) but slightly less (72.90 ± 3.66 mg/L) than both the standards in ABTS. Linoleic (aerial 53.9%, corm 43.9%) and palmitic (aerial 22.2%, corm 18%) were found as the major fatty acids. Discussion and conclusion Some fractions of C. mathewii showed higher antioxidant activities than the standards. There is a need to explore more about this plant.

  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. Phylogeny and Expression Analyses Reveal Important Roles for Plant PKS III Family during the Conquest of Land by Plants and Angiosperm Diversification

    Science.gov (United States)

    Xie, Lulu; Liu, Pingli; Zhu, Zhixin; Zhang, Shifan; Zhang, Shujiang; Li, Fei; Zhang, Hui; Li, Guoliang; Wei, Yunxiao; Sun, Rifei

    2016-01-01

    Polyketide synthases (PKSs) utilize the products of primary metabolism to synthesize a wide array of secondary metabolites in both prokaryotic and eukaryotic organisms. PKSs can be grouped into three distinct classes, types I, II, and III, based on enzyme structure, substrate specificity, and catalytic mechanisms. The type III PKS enzymes function as homodimers, and are the only class of PKS that do not require acyl carrier protein. Plant type III PKS enzymes, also known as chalcone synthase (CHS)-like enzymes, are of particular interest due to their functional diversity. In this study, we mined type III PKS gene sequences from the genomes of six aquatic algae and 25 land plants (1 bryophyte, 1 lycophyte, 2 basal angiosperms, 16 core eudicots, and 5 monocots). PKS III sequences were found relatively conserved in all embryophytes, but not exist in algae. We also examined gene expression patterns by analyzing available transcriptome data, and identified potential cis-regulatory elements in upstream sequences. Phylogenetic trees of dicots angiosperms showed that plant type III PKS proteins fall into three clades. Clade A contains CHS/STS-type enzymes coding genes with diverse transcriptional expression patterns and enzymatic functions, while clade B is further divided into subclades b1 and b2, which consist of anther-specific CHS-like enzymes. Differentiation regions, such as amino acids 196-207 between clades A and B, and predicted positive selected sites within α-helixes in late appeared branches of clade A, account for the major diversification in substrate choice and catalytic reaction. The integrity and location of conserved cis-elements containing MYB and bHLH binding sites can affect transcription levels. Potential binding sites for transcription factors such as WRKY, SPL, or AP2/EREBP may contribute to tissue- or taxon-specific differences in gene expression. Our data shows that gene duplications and functional diversification of plant type III PKS enzymes

  1. Phylogeny and Expression Analyses Reveal Important Roles for Plant PKS III Family during the Conquest of Land by Plants and Angiosperm Diversification.

    Science.gov (United States)

    Xie, Lulu; Liu, Pingli; Zhu, Zhixin; Zhang, Shifan; Zhang, Shujiang; Li, Fei; Zhang, Hui; Li, Guoliang; Wei, Yunxiao; Sun, Rifei

    2016-01-01

    Polyketide synthases (PKSs) utilize the products of primary metabolism to synthesize a wide array of secondary metabolites in both prokaryotic and eukaryotic organisms. PKSs can be grouped into three distinct classes, types I, II, and III, based on enzyme structure, substrate specificity, and catalytic mechanisms. The type III PKS enzymes function as homodimers, and are the only class of PKS that do not require acyl carrier protein. Plant type III PKS enzymes, also known as chalcone synthase (CHS)-like enzymes, are of particular interest due to their functional diversity. In this study, we mined type III PKS gene sequences from the genomes of six aquatic algae and 25 land plants (1 bryophyte, 1 lycophyte, 2 basal angiosperms, 16 core eudicots, and 5 monocots). PKS III sequences were found relatively conserved in all embryophytes, but not exist in algae. We also examined gene expression patterns by analyzing available transcriptome data, and identified potential cis-regulatory elements in upstream sequences. Phylogenetic trees of dicots angiosperms showed that plant type III PKS proteins fall into three clades. Clade A contains CHS/STS-type enzymes coding genes with diverse transcriptional expression patterns and enzymatic functions, while clade B is further divided into subclades b1 and b2, which consist of anther-specific CHS-like enzymes. Differentiation regions, such as amino acids 196-207 between clades A and B, and predicted positive selected sites within α-helixes in late appeared branches of clade A, account for the major diversification in substrate choice and catalytic reaction. The integrity and location of conserved cis-elements containing MYB and bHLH binding sites can affect transcription levels. Potential binding sites for transcription factors such as WRKY, SPL, or AP2/EREBP may contribute to tissue- or taxon-specific differences in gene expression. Our data shows that gene duplications and functional diversification of plant type III PKS enzymes

  2. Phylogeny and Expression Analyses Reveal Important Roles for Plant PKS III Family during the Conquest of Land by Plants and Angiosperm Diversification.

    Science.gov (United States)

    Xie, Lulu; Liu, Pingli; Zhu, Zhixin; Zhang, Shifan; Zhang, Shujiang; Li, Fei; Zhang, Hui; Li, Guoliang; Wei, Yunxiao; Sun, Rifei

    2016-01-01

    Polyketide synthases (PKSs) utilize the products of primary metabolism to synthesize a wide array of secondary metabolites in both prokaryotic and eukaryotic organisms. PKSs can be grouped into three distinct classes, types I, II, and III, based on enzyme structure, substrate specificity, and catalytic mechanisms. The type III PKS enzymes function as homodimers, and are the only class of PKS that do not require acyl carrier protein. Plant type III PKS enzymes, also known as chalcone synthase (CHS)-like enzymes, are of particular interest due to their functional diversity. In this study, we mined type III PKS gene sequences from the genomes of six aquatic algae and 25 land plants (1 bryophyte, 1 lycophyte, 2 basal angiosperms, 16 core eudicots, and 5 monocots). PKS III sequences were found relatively conserved in all embryophytes, but not exist in algae. We also examined gene expression patterns by analyzing available transcriptome data, and identified potential cis-regulatory elements in upstream sequences. Phylogenetic trees of dicots angiosperms showed that plant type III PKS proteins fall into three clades. Clade A contains CHS/STS-type enzymes coding genes with diverse transcriptional expression patterns and enzymatic functions, while clade B is further divided into subclades b1 and b2, which consist of anther-specific CHS-like enzymes. Differentiation regions, such as amino acids 196-207 between clades A and B, and predicted positive selected sites within α-helixes in late appeared branches of clade A, account for the major diversification in substrate choice and catalytic reaction. The integrity and location of conserved cis-elements containing MYB and bHLH binding sites can affect transcription levels. Potential binding sites for transcription factors such as WRKY, SPL, or AP2/EREBP may contribute to tissue- or taxon-specific differences in gene expression. Our data shows that gene duplications and functional diversification of plant type III PKS enzymes

  3. 被子植物的早期胚胎形态建成%Research Progress on Early Embryogenesis in Angiosperms

    Institute of Scientific and Technical Information of China (English)

    李俊; 伍晓明

    2012-01-01

    被子植物早期胚胎形态建成是其有性生殖过程中一个重要发育阶段.在这一阶段中,被子植物形体基本特征形成,包括顶-基轴极性建立、不同细胞层分化以及分生组织形成.合子极性直接与顶基细胞命运相关,但其极性产生机理仍然不明.研究表明,WOX家族转录因子、生长素定向运输以及生长素响应应答可能参与了早期顶-基模型建成;辐射对称模型的建立可能由细胞与细胞间相互作用来介导;生长素流可能参与胚胎顶端组织形成.该文对近年来被子植物早期胚胎形态建成过程中的合子极性建立与生长、合子分裂及其顶基细胞的形成、胚根原特化及根极的形成、辐射对称模式及表皮原特化、顶端分生组织特化及子叶起始等方面的研究进展进行了综述.%Early embryogenesis in angiosperms is an important developmental stage of sexual reproductive process. At this stage,the basic morphology of seedling is established,including apical-basal axial polarity, different cell layers differentiation,and meristem formation. Zygote polarity directly affects the cell fates of apical and basal cell,but the underlying mechanism is still unknown. Previous studies suggested that WOX family transcription factors,direct auxin transportation as well as auxin response may be involved in the establishment of apical-basal patterning. Cell-cell communication may mediate the radial patterning. Additionally, auxin flow participates in the process of apical organization. This paper will review the late research progresses on early embryogenesis of angiosperms,including zygote polarity and elongation,zygote division and apical and basal cell formation, hypophysis specification and root pole formation, radial patterning and protoderm specification,shoot meristem specification and cotyledon initiation.

  4. 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

  5. Getting ready for host invasion: elevated expression and action of xyloglucan endotransglucosylases/hydrolases in developing haustoria of the holoparasitic angiosperm Cuscuta

    Science.gov (United States)

    Olsen, Stian; Striberny, Bernd; Hollmann, Julien; Schwacke, Rainer; Popper, Zoë; Krause, Kirsten

    2016-01-01

    Changes in cell walls have been previously observed in the mature infection organ, or haustorium, of the parasitic angiosperm Cuscuta, but are not equally well charted in young haustoria. In this study, we focused on the molecular processes in the early stages of developing haustoria; that is, before the parasite engages in a physiological contact with its host. We describe first the identification of differentially expressed genes in young haustoria whose development was induced by far-red light and tactile stimuli in the absence of a host plant by suppression subtractive hybridization. To improve sequence information and to aid in the identification of the obtained candidates, reference transcriptomes derived from two species of Cuscuta, C. gronovii and C. reflexa, were generated. Subsequent quantitative gene expression analysis with different tissues of C. reflexa revealed that among the genes that were up-regulated in young haustoria, two xyloglucan endotransglucosylase/hydrolase (XTH) genes were highly expressed almost exclusively at the onset of haustorium development. The same expression pattern was also found for the closest XTH homologues from C. gronovii. In situ assays for XTH-specific action suggested that xyloglucan endotransglucosylation was most pronounced in the cell walls of the swelling area of the haustorium facing the host plant, but was also detectable in later stages of haustoriogenesis. We propose that xyloglucan remodelling by Cuscuta XTHs prepares the parasite for host infection and possibly aids the invasive growth of the haustorium. PMID:26561437

  6. 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。

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Bilirubin present in diverse angiosperms

    OpenAIRE

    Pirone, Cary; Johnson, Jodie V.; Quirke, J. Martin. E.; Priestap, Horacio A.; Lee, David

    2010-01-01

    Background and aims Bilirubin is an orange-yellow tetrapyrrole produced from the breakdown of heme by mammals and some other vertebrates. Plants, algae and cyanobacteria synthesize molecules similar to bilirubin, including the protein-bound bilins and phytochromobilin which harvest or sense light. Recently, we discovered bilirubin in the arils of Strelitzia nicolai, the White Bird of Paradise Tree, which was the first example of this molecule in a higher plant. Subsequently, we identified bil...

  16. New Results of Angiosperm Bryophytes of Inner Mongolia in the Post-Bryophytes Time%内蒙古苔藓植物志后时期苔藓植物区系研究进展

    Institute of Scientific and Technical Information of China (English)

    赫智霞; 徐杰; 白学良; 田桂泉; 李琴琴

    2012-01-01

    本文综述了《内蒙古苔藓植物志》出版之后内蒙古苔藓植物区系研究的新成果.结果表明,在《内蒙古苔藓植物志》出版之后的十多年间,以白学良教授为领导的研究团队,对内蒙古地区苔藓植物的分布、种类多样性等方面进行了深入研究,特别是沙漠地区.在此期间,发现内蒙古苔藓植物新记录1纲;新记录科3科;新记录属16属;新记录种76种、订正种9种.内蒙古苔藓植物区系研究取得了显著成果,为《内蒙古苔藓植物志》的再版编著奠定了坚实的基础.%The paper has overviewed the research new result of angiosperm bryophytes of Inner Mongolian after the publishing edition of "bryophytes Intramongolica".The results indicate: after the "bryophytes Intramongolica " publish ten more years,under the leadership of the professor Bai Xueliang,distribution and species variety of the Inner Mongolia bryophytes go ahead intensive study,especially in desert area.During this time: 1 new record class,3 new record family;16 new record genus;76 new record species,9 revised species were found.In the post-flora time,the research on angiosperm flora of Inner Mongolia has achieved notable progress,which has provide a strong base of the second edition of " Flora Intramongolica ".

  17. Pollen performance, cell number, and physiological state in the early-divergent angiosperm Annona cherimola Mill. (Annonaceae) are related to environmental conditions during the final stages of pollen development.

    Science.gov (United States)

    Lora, J; Herrero, M; Hormaza, J I

    2012-09-01

    Pollen performance is an important determinant for fertilization success, but high variability in pollen behavior both between and within species occurs in different years and under varying environmental conditions. Annona cherimola, an early-divergent angiosperm, is a species that releases a variable ratio of bicellular and tricellular hydrated pollen at anther dehiscence depending on temperature. The presence of both bi- and tricellular types of pollen is an uncommon characteristic in angiosperms and makes Annona cherimola an interesting model to study the effect of varying environmental conditions on subsequent pollen performance during the final stages of pollen development. In this work, we study the influence of changes in temperature and humidity during the final stages of pollen development on subsequent pollen performance, evaluating pollen germination, presence of carbohydrates, number of nuclei, and water content. At 25 °C, which is the average field temperature during the flowering period of this species, pollen had a viability of 60-70 %, starch hydrolyzed just prior to shedding, and pollen mitosis II was taking place, resulting in a mixture of bi- and tricellular pollen. This activity may be related to the pollen retaining 70 % water content at shedding. Temperatures above 30 °C resulted in a decrease in pollen germination, whereas lower temperatures did not have a clear influence on pollen germination, although they did have a clear effect on starch hydrolysis. On the other hand, slightly higher dehydration accelerated mitosis II, whereas strong dehydration arrested starch hydrolysis and reduced pollen germination. These results show a significant influence of environmental conditions on myriad pollen characteristics during the final stages of pollen development modifying subsequent pollen behavior and contributing to our understanding of the variability observed in pollen tube performance.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. Distally lobed integuments in some Angiosperm ovules

    NARCIS (Netherlands)

    Heel, van W.A.

    1970-01-01

    In this treatise ‘De l’Ovule’ Warming (1878) remarked that although the borders of the integuments grow uniformly, very rarely a division into lobes can be observed. He mentioned Symplocarpus foetida (inner integument four-lobed), Lagarosiphon schweinfurthii (outer integument four- or five-lobed) an

  3. 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

  4. Drug: D06749 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available drugs 5100 Crude drugs D06749 Nuphar rhizome (JP16) Traditional Chinese Medicine in Japan [BR:br08304] Crude Drugs Drugs... for blood Drugs for removing blood stasis D06749 Nuphar rhizome; Nup

  5. 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.

  6. Chromosome numbers of some Angiosperm plants in Thailand

    OpenAIRE

    Tanpho, S.; Jansone, A; Jornead, S.; Decharun, S.; Eksomtramage, L.

    2007-01-01

    Chromosome numbers in the root-tip cells of 58 cultivars 27 species belonging to 15 genera of Apocynaceae, Araceae, Campanulaceae, Compositae (Asteraceae), Marantaceae, Musaceae and Plumbaginaceae were determined. Chromosome numbers in Aglaonema commutatum var. maculatum (2n = 40), A. modestum (2n = 80), A. pseudobracteatum (2n = 60), Alocasia lindenii (2n = 28), A. sanderiana (2n = 28), Laurentia longiflora (2n = 26), Gynura pseudochina var. hispida (2n = 20), Calathea lancifolia (2n = 26), ...

  7. Chromosome numbers of some Angiosperm plants in Thailand

    Directory of Open Access Journals (Sweden)

    Tanpho, S.

    2007-01-01

    Full Text Available Chromosome numbers in the root-tip cells of 58 cultivars 27 species belonging to 15 genera of Apocynaceae, Araceae, Campanulaceae, Compositae (Asteraceae, Marantaceae, Musaceae and Plumbaginaceae were determined. Chromosome numbers in Aglaonema commutatum var. maculatum (2n = 40, A. modestum (2n = 80, A. pseudobracteatum (2n = 60, Alocasia lindenii (2n = 28, A. sanderiana (2n = 28, Laurentia longiflora (2n = 26, Gynura pseudochina var. hispida (2n = 20, Calathea lancifolia (2n = 26, C. majestica cv. Roseolineata (2n = 24, C. picturata cv. Argentea (2n = 26 & cv. Vandenheckei (2n = 26, Maranta leuconeura "Mediovariegata" (2n = 52 and Musa sp. (Kluai Hin & Kluai Thong Ruang (2n = 33 are firstly reported.

  8. Viewpoints on apornictic and sexual reproduction in angiosperms

    Directory of Open Access Journals (Sweden)

    Sven Asker

    2014-02-01

    Full Text Available Gametophytic apomixis implies different changes of the reproductive cycle of sexual plants. Each of these "elements of apomixis" occurs in sexual plants, which may even display functional diploid parthenogenesis. Thus, apomixis, like vegetative reproduction, is part of the reproductive behaviour of sexual plants, becoming important when sexual reproduction is impaired. The elements of apomixis are probably to a large extent under polygenic control.

  9. 西藏及其东南地区被子植物与其不同生活型的果实类型分析%Fruit Types of Angiosperm and Their 4 Life Forms in Tibet and Its Southeastern Region

    Institute of Scientific and Technical Information of China (English)

    于顺利; 方伟伟; 泽仁旺姆; 尼珍; 张小凤

    2013-01-01

    统计了分布在西藏自治区的被子植物及各生活型果实的类型及比例,并与藏东南地区做了比较.结果如下,西藏自治区果实以蒴果为主(占37.74%),其次为瘦果、坚果、浆果等;干果的比例远远大于肉果;不同生活型的果实类型谱差异较大,乔木中核果的比例最高,藤本中浆果比例最高,灌木中瘦果比例最高,草本中蒴果占优势;4个生活型中,肉果的比例乔木为最高,其次为藤本、灌木、草本.藏东南地区植物的果实类型也以蒴果为主,其次为瘦果、浆果、核果等;藏东南乔木中核果比例最高,藤本中浆果比例最高,灌木和草本植物以蒴果占优势;乔木肉果的比例最高,其次为藤本、灌木、草本.藏东南肉果比例大于全藏区,而干果比例则相反.果实类型的这些性状特征与各自的环境相适应,是植物长期适应自然环境的进化结果,该研究对于理解植物果实对生态环境的长期适应进化具有一定的意义.%This article calculated the percentages of different fruit types of total angiosperms (5810 species,28 varieties) and their life forms (trees,shrubs,herbs and lianas) distributed in Tibet and southeastern Tibet.The results showed that in Tibet capsule is the dominant fruit type (37.74% ) ,followed by achene,nut and berry.The percentage of dry fruits is far bigger than that of fleshy fruits in Tibet.There are great variations in 4 life forms in fruit type spectrum.Drupe is dominant in tree,berry in liana,achene in shrub,and capsule in herb.Tree possesses the greatest percentage of fleshy fruit in 4 life forms,followed by liana,shrub and herb.In southeastern Tibet,capsule is also the dominant fruit type (37.54% ) ,followed by achene,berry,drupe,nut and caryopsis.The larger differences occur among the percentages of various fruit types.Drupe is dominant in tree,berry in liana,capsule in shrub and in herb.In the 4 life forms tree possesses the largest

  10. 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

  11. 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.

  12. 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 ...

  13. 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

  14. 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.

  15. Evolutionary patterns of range size, abundance and species richness in Amazonian angiosperm trees

    Science.gov (United States)

    Chave, Jérôme

    2016-01-01

    Amazonian tree species vary enormously in their total abundance and range size, while Amazonian tree genera vary greatly in species richness. The drivers of this variation are not well understood. Here, we construct a phylogenetic hypothesis that represents half of Amazonian tree genera in order to contribute to explaining the variation. We find several clear, broad-scale patterns. Firstly, there is significant phylogenetic signal for all three characteristics; closely related genera tend to have similar numbers of species and similar mean range size and abundance. Additionally, the species richness of genera shows a significant, negative relationship with the mean range size and abundance of their constituent species. Our results suggest that phylogenetically correlated intrinsic factors, namely traits of the genera themselves, shape among lineage variation in range size, abundance and species richness. We postulate that tree stature may be one particularly relevant trait. However, other traits may also be relevant, and our study reinforces the need for ambitious compilations of trait data for Amazonian trees. In the meantime, our study shows how large-scale phylogenies can help to elucidate, and contribute to explaining, macroecological and macroevolutionary patterns in hyperdiverse, yet poorly understood regions like the Amazon Basin. PMID:27651991

  16. 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.

  17. Flower Development and Perianth Identity Candidate Genes in the Basal Angiosperm Aristolochia fimbriata (Piperales: Aristolochiaceae)

    Science.gov (United States)

    Pabón-Mora, Natalia; Suárez-Baron, Harold; Ambrose, Barbara A.; González, Favio

    2015-01-01

    Aristolochia fimbriata (Aristolochiaceae: Piperales) exhibits highly synorganized flowers with a single convoluted structure forming a petaloid perianth that surrounds the gynostemium, putatively formed by the congenital fusion between stamens and the upper portion of the carpels. Here we present the flower development and morphology of A. fimbriata, together with the expression of the key regulatory genes that participate in flower development, particularly those likely controlling perianth identity. A. fimbriata is a member of the magnoliids, and thus gene expression detected for all ABCE MADS-box genes in this taxon, can also help to elucidate patterns of gene expression prior the independent duplications of these genes in eudicots and monocots. Using both floral development and anatomy in combination with the isolation of MADS-box gene homologs, gene phylogenetic analyses and expression studies (both by reverse transcription PCR and in situ hybridization), we present hypotheses on floral organ identity genes involved in the formation of this bizarre flower. We found that most MADS-box genes were expressed in vegetative and reproductive tissues with the exception of AfimSEP2, AfimAGL6, and AfimSTK transcripts that are only found in flowers and capsules but are not detected in leaves. Two genes show ubiquitous expression; AfimFUL that is found in all floral organs at all developmental stages as well as in leaves and capsules, and AfimAG that has low expression in leaves and is found in all floral organs at all stages with a considerable reduction of expression in the limb of anthetic flowers. Our results indicate that expression of AfimFUL is indicative of pleiotropic roles and not of a perianth identity specific function. On the other hand, expression of B-class genes, AfimAP3 and AfimPI, suggests their conserved role in stamen identity and corroborates that the perianth is sepal and not petal-derived. Our data also postulates an AGL6 ortholog as a candidate gene for sepal identity in the Aristolochiaceae and provides testable hypothesis for a modified ABCE model in synorganized magnoliid flowers. PMID:26697047

  18. Toxicity and metabolism of 2,4-dichlorophenol by the aquatic angiosperm Lemna gibba

    Energy Technology Data Exchange (ETDEWEB)

    Ensley, H.E. (Tulane Univ., New Orleans, LA (United States). Dept. of Chemistry); Barber, J.T.; Polito, M.A.; Oliver, A.I. (Tulane Univ., New Orleans, LA (United States). Dept. of Ecology, Evolution, and Organismal Biology)

    1994-02-01

    The toxicity and metabolism of 2,4-dichlorophenol with regard to the aquatic macrophyte Lemna gibba (duckweed), have been studied. Toxicity is described in terms of the effect of 2,4-dichlorophenol (2,4-DCP) on the vegetative reproduction of duckweed over a 10-d growth period; the EC10 and EC50 were 2.5 and 9.2 [mu]M, respectively. Metabolism of 2,4-dichlorophenol was monitored by incubation of the plants with radiolabeled substrate, and periodic sampling and analysis by reversed-phase HPLC of the plant growth medium. Depending on the growth conditions, up to 95% of the 2,4-DCP was metabolized over a 6-d growth period. To analyze the metabolites, the plants were grown in the presence of sublethal concentrations of [U-[sup 14]C]-2,4-DCP. The growth medium was lyophilized and then mixed with the plants, extracted, and analyzed using reversed-phase HPLC, followed by scintillation counting of the fractions. The major metabolite was isolated and identified as 2,4-dichlorophenol-[beta]-D-glucopyranoside by high-field NMR and MS. The structure of the metabolite was confirmed by synthesis and by enzymatic cleavage of the [beta]-glucosidic linkage to afford 2,4-DCP. An important consequence of conjugate formation is the masking of the presence of 2,4-DCP to the usual analytical techniques used for its detection and quantitation. This finding is probably applicable to other contaminants and organisms.

  19. Potentiation of aquatic pollution by ethylene glycol with regard to the aquatic angiosperm, Lemna gibba

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, D.A.; Barber, J.T.; Yatsu, L.Y.; Ensley, H.E. [Tulane Univ., New Orleans, LA (United States). Dept. of Ecology, Evolution and Organismal Biology

    1995-12-31

    Ethylene glycol is usually thought of as a benign component of urban runoff. Thus, its EC50 value, with regard to the vegetative growth of axenically grown Lemna gibba, is relatively high, viz. 164 mM. Ethylene glycol is not metabolized by Lemna but growth is demonstrably stimulated at concentrations below 75 mM. In the presence of ethylene glycol, the fronds of duckweed are dark green, translucent and the growth medium contains gas bubbles of carbon dioxide which result from an enhanced uptake of sucrose from the growth medium and its subsequent respiration. The uptake is a non-specific effect since the uptake of various other compounds, including water, is enhanced when duckweed is grown in the presence of ethylene glycol. The increased uptake of water, sucrose, inorganic ions and organic compounds results from an increased permeability due to the creation of intercellular holes in the aerenchymatous tissues of the ethylene glycol-treated plants. The mechanism by which ethylene glycol causes the holes is unknown but may involve a disruption in lipid metabolism since the hydrophobicity of the fronds is altered and their lipid composition is changed. The significance of this phenomenon is that toxicants, just like innocuous substances, are taken up in increased amounts by treated plants and as a result their toxicities are increased with regard to duckweed as evidenced by a decrease in their effective concentrations, often of more than 3-fold. These results suggest that although ethylene glycol itself may be benign, its presence in polluted waters containing other toxicants may potentiate the effects of those pollutants.

  20. A website for all angiosperm families – http://www.mobot.org/mobot/research/apweb/

    NARCIS (Netherlands)

    Stevens, P.F.

    2002-01-01

    Currently both those teaching and those learning about phylogenies face a variety of problems. There are several systems to chose from, yet there is no explicitly phylogenetic system (in the sense of recognizing only strictly monophyletic groups) where all those groups are described. Conventional fa

  1. Dioecy does not consistently accelerate or slow lineage diversification across multiple genera of angiosperms.

    Science.gov (United States)

    Sabath, Niv; Goldberg, Emma E; Glick, Lior; Einhorn, Moshe; Ashman, Tia-Lynn; Ming, Ray; Otto, Sarah P; Vamosi, Jana C; Mayrose, Itay

    2016-02-01

    Dioecy, the sexual system in which male and female organs are found in separate individuals, allows greater specialization for sex-specific functions and can be advantageous under various ecological and environmental conditions. However, dioecy is rare among flowering plants. Previous studies identified contradictory trends regarding the relative diversification rates of dioecious lineages vs their nondioecious counterparts, depending on the methods and data used. We gathered detailed species-level data for dozens of genera that contain both dioecious and nondioecious species. We then applied a probabilistic approach that accounts for differential speciation, extinction, and transition rates between states to examine whether there is an association between dioecy and lineage diversification. We found a bimodal distribution, whereby dioecious lineages exhibited higher diversification in certain genera but lower diversification in others. Additional analyses did not uncover an ecological or life history trait that could explain a context-dependent effect of dioecy on diversification. Furthermore, in-depth simulations of neutral characters demonstrated that such bimodality is also found when simulating neutral characters across the observed trees. Our analyses suggest that - at least for these genera with the currently available data - dioecy neither consistently places a strong brake on diversification nor is a strong driver.

  2. 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.

  3. Angiosperm n-alkane distribution patterns and the geologic record of C4 grassland evolution

    Science.gov (United States)

    Henderson, A.; Graham, H. V.; Patzkowsky, M.; Fox, D. L.; Freeman, K. H.

    2012-12-01

    n-Alkane average chain-length (ACL) patterns vary regionally with community composition and climate. To clarify the influence of phylogenetic and community patterns, we compiled and analyzed a global database of published n-alkane abundance for n-C27 to C35 homologs in modern plant specimens (n=205). ACL for waxes in C4 non-woody plants are longer than for woody plants, suggesting ACL can serve as an indicator of the three-dimensional structure of local vegetation. Further, these findings suggest compound-specific isotopic data for longer alkane homologs (C31, C33, C35) will proportionately represent non-woody vegetation and isotope measurements of C29 are more representative of woody vegetation. Thus, the combination of ACL and carbon isotope compositions should allow us to disentangle C3 woody, C3 non-woody, and C4 non-woody signals in terrestrial paleorecords. Application of this approach to the geologic record of Miocene C4 grassland expansion in the US Great Plains and the Siwaliks in Pakistan illustrate two very different transition scenarios. Alkane-specific isotopic data indicate C4 grasslands appeared 2.5 Ma in the Great Plains and 6.5 Ma in the Siwaliks, and ACL analysis indicates that this transition involved the replacement of woody vegetation in the US and the replacement of C3 grasses in Pakistan. Our analysis illustrates that, consistent with differences in the timing of C4 grassland, the drivers of change were likely not the same in these regions. Oxygen isotope records suggest that the more recent transition in the Great Plains was associated with climate cooling and possibly changes in disturbance regimes and that the transition in the Siwaliks was likely associated with warming and drying.

  4. 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

  5. Whole-genome duplications followed by tandem duplications drive diversification of the protein modifier SUMO in Angiosperms

    NARCIS (Netherlands)

    V. Hammoudi; G. Vlachakis; M.E. Schranz; H.A. van den Burg

    2016-01-01

    The ubiquitin-like modifier (UBL) SUMO (Small Ubiquitin-Like Modifier) regulates protein function. Structural rather than sequence homology typifies UBL families. However, individual UBL types, such as SUMO, show remarkable sequence conservation. Selection pressure also operates at the SUMO gene cop

  6. Whole-genome duplications followed by tandem duplications drive diversification of the protein modifier SUMO in Angiosperms

    NARCIS (Netherlands)

    Hammoudi, Valentin; Vlachakis, Georgios; Schranz, Eric; Burg, van den Harrold A.

    2016-01-01

    The ubiquitin-like modifier (UBL) SUMO (Small Ubiquitin-Like Modifier) regulates protein function. Structural rather than sequence homology typifies UBL families. However, individual UBL types, such as SUMO, show remarkable sequence conservation. Selection pressure also operates at the SUMO gene

  7. 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

  8. 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...

  9. 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

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    LUIZ W. LIMA-VERDE

    2014-09-01

    Full Text Available 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.

  12. 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

  13. 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

  14. 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

  15. 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...

  16. 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.

  17. 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...

  18. 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 ...

  19. 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...

  20. 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

  1. 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...

  2. 被子植物配子形成过程中表观遗传学调控%Epigenetic Regulation in Angiosperm Gamete Development

    Institute of Scientific and Technical Information of China (English)

    刘茜阳; 罗云; 李桥; 闫海芳

    2014-01-01

    Gametes is generated by the mature cells in reproductive system when biological sexual reproduction occur. The development of vegetative cell, central cell and sperm cell, which is regulated by the inducing si-lencing mechanisms of DNA methylation and small RNA. The histone modiifcation can make the egg cell and center cell form their own particular hereditary features, and it can also control the state of the sperm chromatin. This review focuses on the latest research advances in the epigenetic regulation in plant gamete development, including DNA methylation, small RNA-induced silencing, gene imprinting, chromatin modiifcation and his-tone modiifcations.%配子(gamete)是指生物进行有性生殖时由生殖系统所产生的成熟性细胞。DNA甲基化和小RNA诱导沉默机制调控营养细胞、中央细胞和精子细胞的发育。组蛋白修饰可使卵细胞和中央细胞形成各自鲜明的表观遗传特点,也可调控精子染色质的状态。本文综述了雌雄配子发育的表观遗传学调控机制,包括DNA甲基化、小RNA诱导沉默、染色质修饰和组蛋白修饰等方面研究的最新进展。

  3. Conserved Roles of CrRLK1L Receptor-Like Kinases in Cell Expansion and Reproduction from Algae to Angiosperms.

    Science.gov (United States)

    Galindo-Trigo, Sergio; Gray, Julie E; Smith, Lisa M

    2016-01-01

    Receptor-like kinases (RLKs) are regulators of plant development through allowing cells to sense their extracellular environment. They facilitate detection of local endogenous signals, in addition to external biotic and abiotic stimuli. The Catharanthus roseus RLK1-like (CrRLK1L) protein kinase subfamily, which contains FERONIA, plays a central role in regulating fertilization and in cell expansion mechanisms such as cell elongation and tip growth, as well as having indirect links to plant-pathogen interactions. Several components of CrRLK1L signaling pathways have been identified, including an extracellular ligand, coreceptors, and downstream signaling elements. The presence and abundance of the CrRLK1L proteins in the plant kingdom suggest an origin within the Streptophyta lineage, with a notable increase in prevalence in the seeded land plants. Given the function of the sole CrRLK1L protein in a charophycean alga, the possibility of a conserved role in detection and/or regulation of cell wall integrity throughout the Strephtophytes is discussed. Orthologs of signaling pathway components are also present in extant representatives of non-vascular land plants and early vascular land plants including the liverwort Marchantia polymorpha, the moss Physcomitrella patens and the lycophyte Selaginella moellendorffii. Deciphering the roles in development of the CrRLK1L protein kinases in early diverging land plants will provide insights into their ancestral function, furthering our understanding of this diversified subfamily of receptors in higher plants. PMID:27621737

  4. 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 ...

  5. Reassessing morphological homologies in the early-divergent angiosperm Fenerivia (annonaceae) based on floral vascular anatomy: significance for interpreting putative homeotic mutations.

    Science.gov (United States)

    Xue, Bine; Saunders, Richard M K

    2013-01-01

    Fenerivia species (Annonaceae) are characterized by a prominent flange immediately below the perianth, which has been interpreted as synapomorphic for the genus. The homology of this flange is controversial: previous studies of Fenerivia heteropetala (an aberrant species, with 12 perianth parts in three whorls) have suggested that the flange may represent a vestigial calyx resulting from a disruption to the homeotic control of organ identity during floral development. Comparative data on floral vasculature in Fenerivia capuronii are presented to elucidate the homology of the flange in other Fenerivia species (which possess nine perianth parts in three whorls, typical of most Annonaceae). The flange in F. capuronii differs from that in F. heteropetala as it is unvascularized. It is nevertheless suggested that the flange is likely to be homologous, and that a homeotic mutation in the F. heteropetala lineage resulted in the formation of a vestigial but vascularized calyx that fused with the otherwise unvascularized flange.

  6. Molecular phylogenetics of the species-rich angiosperm genus Goniothalamus (Annonaceae) inferred from nine chloroplast DNA regions: Synapomorphies and putative correlated evolutionary changes in fruit and seed morphology.

    Science.gov (United States)

    Tang, Chin Cheung; Thomas, Daniel C; Saunders, Richard M K

    2015-11-01

    A phylogenetic study of the genus Goniothalamus (Annonaceae) is presented using maximum parsimony, maximum likelihood and Bayesian approaches, with 65 species sampled (48.5% of the genus) based on sequences of nine chloroplast DNA regions (11,214 aligned positions). The resultant phylogeny clearly indicates that Goniothalamus is monophyletic. Preliminary research initially focused on identifying synapomorphies and estimating the phylogenetic signal of selected morphological characters based on parsimony and likelihood ancestral character state reconstructions. This prescreening of characters enabled 40 to be selected for further study, and of these 15 are shown here to demonstrate significant phylogenetic signal and to provide clear synapomorphies for several infrageneric clades. Although floral structure in Goniothalamus is comparatively uniform, suggesting a common basic pattern of pollination ecology, fruit and seed morphology in the genus is very diverse and is presumably associated with different patterns of frugivory. The present study assesses correlations amongst fruit and seed characters which are putatively of functional importance with regard to frugivory and dispersal. One-way phylogenetic ANOVA indicates significant phylogenetically independent correlation between the following fruit and seed characters: fruits borne on older branches and/or on the main trunk have larger monocarps than fruits borne on young branches; and monocarps that contain seeds with a hairy testa are larger than those with glabrous seeds. We discuss fruit morphologies and potential explanations for the inferred correlations, and suggest that they may be the result of adaptation to different frugivores (birds, larger non-volant animal and primate seed dispersers, respectively).

  7. Conserved roles of CrRLK1L receptor-like kinases in cell expansion and reproduction from algae to angiosperms

    Directory of Open Access Journals (Sweden)

    Sergio Galindo Trigo

    2016-08-01

    Full Text Available Receptor-like kinases (RLKs are regulators of plant development through allowing cells to sense their extracellular environment. They facilitate detection of local endogenous signals, in addition to external biotic and abiotic stimuli. The Catharanthus roseus RLK1-like (CrRLK1L protein kinase subfamily, which contains FERONIA, plays a central role in regulating fertilization and in cell expansion mechanisms such as cell elongation and tip growth, as well as having indirect links to plant-pathogen interactions. Several components of CrRLK1L signaling pathways have been identified, including an extracellular ligand, coreceptors and downstream signaling elements. The presence and abundance of the CrRLK1L proteins in the plant kingdom suggest an origin within the Streptophyta lineage, with a notable increase in prevalence in the seeded land plants. Given the function of the sole CrRLK1L protein in a charophycean alga, the possibility of a conserved role in detection and/or regulation of cell wall integrity throughout the Strephtophytes is discussed. Orthologs of signaling pathway components are also present in extant representatives of non-vascular land plants and early vascular land plants including the liverwort Marchantia polymorpha, the moss Physcomitrella patens and the lycophyte Selaginella moellendorffii. Deciphering the roles in development of the CrRLK1L protein kinases in early diverging land plants will provide insights into their ancestral function, furthering our understanding of this diversified subfamily of receptors in higher plants.

  8. Conserved Roles of CrRLK1L Receptor-Like Kinases in Cell Expansion and Reproduction from Algae to Angiosperms

    Science.gov (United States)

    Galindo-Trigo, Sergio; Gray, Julie E.; Smith, Lisa M.

    2016-01-01

    Receptor-like kinases (RLKs) are regulators of plant development through allowing cells to sense their extracellular environment. They facilitate detection of local endogenous signals, in addition to external biotic and abiotic stimuli. The Catharanthus roseus RLK1-like (CrRLK1L) protein kinase subfamily, which contains FERONIA, plays a central role in regulating fertilization and in cell expansion mechanisms such as cell elongation and tip growth, as well as having indirect links to plant–pathogen interactions. Several components of CrRLK1L signaling pathways have been identified, including an extracellular ligand, coreceptors, and downstream signaling elements. The presence and abundance of the CrRLK1L proteins in the plant kingdom suggest an origin within the Streptophyta lineage, with a notable increase in prevalence in the seeded land plants. Given the function of the sole CrRLK1L protein in a charophycean alga, the possibility of a conserved role in detection and/or regulation of cell wall integrity throughout the Strephtophytes is discussed. Orthologs of signaling pathway components are also present in extant representatives of non-vascular land plants and early vascular land plants including the liverwort Marchantia polymorpha, the moss Physcomitrella patens and the lycophyte Selaginella moellendorffii. Deciphering the roles in development of the CrRLK1L protein kinases in early diverging land plants will provide insights into their ancestral function, furthering our understanding of this diversified subfamily of receptors in higher plants. PMID:27621737

  9. 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.

  10. Situação amostral e riqueza de espécies das Angiospermas do estado do Ceará, Brasil Sampling effort and species richness of Angiosperms in the state of Ceará, Brazil

    Directory of Open Access Journals (Sweden)

    Regina Celli Araújo de Freitas

    2010-12-01

    Full Text Available O estado do Ceará, situado no nordeste brasileiro, apresenta predomínio do clima semi-árido. Objetivando um delineamento para futuros inventários florísticos, realizou-se uma averiguação preliminar do esforço de coleta em seu território. Para isto, o estudo da amostragem e da riqueza de espécies das famílias Asteraceae, Euphorbiaceae, Fabaceae, Poaceae e Rubiaceae foram analisadas. Assim como, a distribuição geográfica das amostras foi correlacionada às sete unidades fitoecológicas do estado do Ceará: caatinga arbustiva, caatinga arbórea, carrasco, cerradão, complexo litorâneo, mata seca e mata úmida. Os dados utilizados foram obtidos da coleção do Herbário Prisco Bezerra (EAC, sendo reunidos através do software BRAHMS. Desde 1933 até agosto de 2008, foram registradas na coleção: 11.551 exsicatas (exs. representando 1.209 espécies (spp.. Este total de exsicatas está distribuído da seguinte forma entre as unidades fitoecológicas: mata úmida 27% exs. e 33% spp., complexo litorâneo 24% exs. e 24% spp., caatinga arbustiva 16% exs. e 19% spp., carrasco 13% exs. e 17% spp., mata seca 10% exs. e 9% spp., caatinga arbórea 8% exs. e 12%; e cerradão 2% exs. e 3% spp. Os dados evidenciam um maior esforço de coleta e riqueza de espécies nas áreas de mata úmida e no complexo litorâneo, seguidos das áreas da caatinga arbustiva e arbórea. Com apenas 5% do território cearense, a mata úmida supera a amostragem das caatingas, que detêm 70% do estado do Ceará. Portanto, observamos a ocorrência satisfatória de coletas na mata úmida, em detrimento das outras unidades, tornando necessária a elaboração de novos projetos visando um maior esforço de coleta nessas áreas subamostradas.The state of Ceará, located in northeast Brazil, has a predominantly semi-arid climate. To guide future inventories of the flora, a preliminary survey of collections in the state was made, where we analyzed sampling effort and species richness of Asteraceae, Euphorbiaceae, Fabaceae, Poaceae and Rubiaceae. Geographic distribution of the samples was correlated to the seven phytoecological units of Ceará state: caatinga arbustiva, caatinga arbórea, carrasco, cerradão, complexo litorâneo, mata seca and mata úmida. The data were obtained from the Prisco Bezerra Herbarium (EAC collection and were combined using the software BRAHMS. From 1933 to August 2008, this collection registered the following: 11,551 exsiccatae (exs. representing 1,209 species (spp.. This total number of exsiccatae is distributed as follows among the phytoecological units: mata úmida 27% exs. and 33% spp., complexo litorâneo 24% exs. and 24% spp., caatinga arbustiva 16% exs. and 19% spp., carrasco 13% exs. and 17% spp., mata seca 10% exs. and 9% spp., caatinga arbórea 8% exs. and 12% and cerradão 2% exs. and 3% spp. These data reveal greater collection effort and species richness in areas of mata úmida and complexo litorâneo, followed by areas of caatinga arbustiva and caatinga arbórea. With only 5% of Ceara's territory, sampling in mata úmida surpasses that in caatingas, the latter with 70% of the state's territory. Therefore, a satisfactory number of collections in mata úmida was observed to the detriment of other units, making it necessary to draw up new projects aimed at a greater effort in these sub-sampling collection areas.

  11. Co-ordination in Morphological Leaf Traits of Early Diverging Angiosperms Is Maintained Following Exposure to Experimental Palaeo-atmospheric Conditions of Sub-ambient O2 and Elevated CO2

    Science.gov (United States)

    Evans-Fitz.Gerald, Christiana; Porter, Amanda S.; Yiotis, Charilaos; Elliott-Kingston, Caroline; McElwain, Jennifer C.

    2016-01-01

    In order to be successful in a given environment a plant should invest in a vein network and stomatal distribution that ensures balance between both water supply and demand. Vein density (Dv) and stomatal density (SD) have been shown to be strongly positively correlated in response to a range of environmental variables in more recently evolved plant species, but the extent of this relationship has not been confirmed in earlier diverging plant lineages. In order to examine the effect of a changing atmosphere on the relationship between Dv and SD, five early-diverging plant species representing two different reproductive plant grades were grown for 7 months in a palaeo-treatment comprising an O2:CO2 ratio that has occurred multiple times throughout plant evolutionary history. Results show a range of species-specific Dv and SD responses to the palaeo-treatment, however, we show that the strong relationship between Dv and SD under modern ambient atmospheric composition is maintained following exposure to the palaeo-treatment. This suggests strong inter-specific co-ordination between vein and stomatal traits for our study species even under relatively extreme environmental change. This co-ordination supports existing plant function proxies that use the distance between vein endings and stomata (Dm) to infer plant palaeo-physiology. PMID:27695464

  12. 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)

  13. 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

  14. 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.

  15. 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...

  16. 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.

  17. 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.

  18. 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...

  19. Temporal Assemblage Turnovers of Foraminiferal Communities from the Caribbean, United Kingdom and Mediterranean regions

    Science.gov (United States)

    Costelloe, Ashleigh; Wilson, Brent

    2016-04-01

    Temporal assemblage turnovers of intertidal foraminiferal communities were quantitatively determined using the assemblage turnover index (ATI), and contributing species were identified using the conditioned on-boundary index (CoBI). The live foraminiferal communities were examined as metacommunities (all stations) and assemblages (groups of stations defined by cluster analysis) over one and two year periods at Caroni Swamp, Claxton Bay (E Trinidad), Cowpen Marsh (NE England) and Bay of Cádiz (SW Spain). Major assemblage turnovers (when ATI > x + σ) of the Caroni Swamp metacommunity and assemblages coincided with seasonal changes from dry to wet conditions in 2011 and 2012. The abundant species (Ammonia tepida, Ammotium salsum, Arenoparella mexicana, Trochammina advena, Trochammina laevigata and Trochammina inflata) contributed the most to assemblage turnovers but showed no preference to either dry or wet conditions. At Claxton Bay major assemblage turnovers of the metacommunity and mid assemblage coincided with seasonal change and calcareous species (A. tepida and Triloculina oblonga) increased during wet conditions and decreased during dry conditions, while agglutinated species (T. advena and A. salsum) fluctuated oppositely. At Cowpen Marsh major assemblage turnovers of the metacommunity coincided with the start of summer and winter. Assemblages at higher elevations (mainly Jadammina macrescens and Haplophragmoides spp.) were responsible for the summer turnover, while the winter turnover was led by the assemblage at lower elevations (mainly Haynesina germanica, Elphidium earlandi, Elphidium williamsoni, Elphidium excavatum and Quinqueloculina spp.). At Bay of Cádiz, the foraminiferal assemblage at a tidal height of 1.5 to 1.7 m above the hydrographic zero was examined within three separate plots, and the seasonal occurrence of assemblage turnovers differed between plots. Thus, replicate samples and multiple plots may be necessary to overcome spatial

  20. 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...

  1. 7 CFR 340.1 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... form of any member of the plant kingdom 3 including, but not limited to, eukaryotic algae, mosses, club mosses, ferns, angiosperms, gymnosperms, and lichens (which contain algae) including any parts...

  2. Cytokinin-induced promotion of root meristem size in the fern Azolla supports a shoot-like origin of euphyllophyte roots

    NARCIS (Netherlands)

    de Vries, Jan; Fischer, Angela Melanie; Roettger, Mayo; Rommel, Sophie; Schluepmann, Henriette; Bräutigam, Andrea; Carlsbecker, Annelie; Gould, Sven Bernhard

    2016-01-01

    The phytohormones cytokinin and auxin orchestrate the root meristem development in angiosperms by determining embryonic bipolarity. Ferns, having the most basal euphyllophyte root, form neither bipolar embryos nor permanent embryonic primary roots but rather an adventitious root system. This raises

  3. Chromosome numbers of some Angiospermae collected in Cameroun and the Ivory Coast

    NARCIS (Netherlands)

    Gadella, Th.W.J.

    1969-01-01

    The chromosome numbers of 16 species of Angiosperms, collected in Cameroun and the Ivory Coast, were determined. The numbers given for 14 species are new, in the remaining species the results of other authors could be confirmed.

  4. 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

  5. New additions to the flora of Uttarakhand, India

    Directory of Open Access Journals (Sweden)

    D.S. Rawat

    2014-07-01

    Full Text Available Botanical explorations in different parts of Uttarakhand resulted in collection of seven angiosperm species which were not known previously from the state. These are described here with images of live plants and herbarium specimens.

  6. 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

  7. Marine macrophytes and the Water Framework Directive: preliminary studies in southern Spain

    OpenAIRE

    Hern??ndez, Ignacio; Bermejo, Ricardo; Garc??a-Mar??n, Patricia; Brun, Fernando G.; Vergara, Juan J.

    2010-01-01

    The Water Framework Directive (WFD) includes angiosperms and macroalgae as biological quality elements (BQE) for coastal and transitional waters. In southern Spain (Andalusia), studies to implement the WFD using angiosperms (seagrasses) started in June 2009. Different approaches have been considered; the first was the variation of this BQE along an environmental gradient; the second consisted on an extensive sampling campaign in the coastal waters from the western province of Huelva to the...

  8. 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...

  9. 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...

  10. Self-incompatibility systems: barriers to self-fertilization in flowering plants.

    Science.gov (United States)

    Rea, Anne C; Nasrallah, June B

    2008-01-01

    Flowering plants (angiosperms) are the most prevalent and evolutionarily advanced group of plants. Success of these plants is owed to several unique evolutionary adaptations that aid in reproduction: the flower, the closed carpel, double fertilization, and the ultimate products of fertilization, seeds enclosed in the fruit. Angiosperms exhibit a vast array of reproductive strategies, including both asexual and sexual, the latter of which includes both self-fertilization and cross-fertilization. Asexual reproduction and self-fertilization are important reproductive strategies in a variety of situations, such as when mates are scarce or when the environment remains relatively stable. However, reproductive strategies promoting cross-fertilization are critical to angiosperm success, since they contribute to the creation of genetically diverse populations, which increase the probability that at least one individual in a population will survive given changing environmental conditions. The evolution of several physical and genetic barriers to self-fertilization or fertilization among closely related individuals is thus widespread in angiosperms. A major genetic barrier to self-fertilization is self-incompatibility (SI), which allows female reproductive cells to discriminate between "self" and "non-self" pollen, and specifically reject self pollen. Evidence for the importance of SI in angiosperm evolution lies in the highly diverse set of mechanisms used by various angiosperm families for recognition of self pollen tube development and preventing self-fertilization.

  11. 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.

  12. A Floricaula/Leafy gene homolog is preferentially expressed in developing female cones of the tropical pine Pinus caribaea var. caribaea

    Directory of Open Access Journals (Sweden)

    Marcelo Carnier Dornelas

    2005-01-01

    Full Text Available In angiosperms, flower formation is controlled by meristem identity genes, one of which, FLORICAULA (FLO/LEAFY (LFY, plays a central role. It is not known if the formation of reproductive organs of pre-angiosperm species is similarly regulated. Here, we report the cloning of a conifer (Pinus caribaea var. caribaea FLO/LFY homolog, named PcLFY. This gene has a large C-terminal region of high similarity to angiosperm FLO/LFY orthologs and shorter regions of local similarity. In contrast to angiosperms, conifers have two divergent genes resembling LFY. Gymnosperm FLO/LFY proteins constitute a separate clade, that can be divided into two divergent groups. Phylogenetic analysis of deduced protein sequences has shown that PcLFY belongs to the LFY-like clade. Northern hybridization analysis has revealed that PcLFY is preferentially expressed in developing female cones but not in developing male cones. This expression pattern was confirmed by in situ hybridization and is consistent with the hypothesis of PcLFY being involved in the determination of the female cone identity. Additionally, mutant complementation experiments have shown that the expression of the PcLFY coding region, driven by the Arabidopsis LFY promoter, can confer the wild-type phenotype to lfy-26 transgenic mutants, suggesting that both gymnosperm and angiosperm LFY homologs share the same biological role.

  13. 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

  14. 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.

  15. 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

  16. 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

  17. Contributions of plant molecular systematics to studies of molecular evolution.

    Science.gov (United States)

    Soltis, E D; Soltis, P S

    2000-01-01

    Dobzhansky stated that nothing in biology makes sense except in the light of evolution. A close corollary, and the central theme of this paper, is that everything makes a lot more sense in the light of phylogeny. Systematics is in the midst of a renaissance, heralded by the widespread application of new analytical approaches and the introduction of molecular techniques. Molecular phylogenetic analyses are now commonplace, and they have provided unparalleled insights into relationships at all levels of plant phylogeny. At deep levels, molecular studies have revealed that charophyte green algae are the closest relatives of the land plants and suggested that liverworts are sister to all other extant land plants. Other studies have suggested that lycopods are sister to all other vascular plants and clarified relationships among the ferns. The impact of molecular phylogenetics on the angiosperms has been particularly dramatic--some of the largest phylogenetic analyses yet conducted have involved the angiosperms. Inferences from three genes (rbcL, atpB, 18S rDNA) agree in the major features of angiosperm phylogeny and have resulted in a reclassification of the angiosperms. This ordinal-level reclassification is perhaps the most dramatic and important change in higher-level angiosperm taxonomy in the past 200 years. At lower taxonomic levels, phylogenetic analyses have revealed the closest relatives of many crops and 'model organisms' for studies of molecular genetics, concomitantly pointing to possible relatives for use in comparative studies and plant breeding. Furthermore, phylogenetic information has contributed to new perspectives on the evolution of polyploid genomes. The phylogenetic trees now available at all levels of the taxonomic hierarchy for angiosperms and other green plants should play a pivotal role in comparative studies in diverse fields from ecology to molecular evolution and comparative genetics.

  18. Composición taxonómica, distribución y bionomía de la familia Noteridae (Coleoptera: Adephaga en Cuba Taxonomic composition, distribution and bionomics of the family Noteridae (Coleoptera: Adephaga in Cuba

    Directory of Open Access Journals (Sweden)

    Yoandri S. Megna

    2006-07-01

    Full Text Available La presente investigación analiza la composición taxonómica, distribución y bionomía de los notéridos registrados en Cuba, y se brinda una clave para su identificación. El estudio se realizó sobre la base de datos bibliográficos a nivel regional y nacional, así como del material colectado en diferentes localidades del país. Este trabajo permitió definir la lista de especies, su distribución por distritos fitogeográficos y los aspectos más generales de su bionomía. Se determinó que la familia Noteridae está compuesta por cinco géneros ( Hydrocanthus Say, Mesonoterus Sharp , Suphis Aubé , Suphisellus Crotch y Notomicrus Sharp y 10 especies, de las cuales Suphisellus tenuicornis (Chevrolat es endémica, e Hydrocanthus advena Sharp no está confirmada. Las especies registradas están distribuidas en 11 (28,2% de los 39 distritos fitogeográficos establecidos. El distrito de mayor riqueza de especies es el Nº 15 (Planicie Centro-Occidental, con ocho especies. La especie más ampliamente distribuida es Notomicrus sharpi J. Balfour-Browne, reportada para seis (15,4% distritos. Los datos bionómicos muestran que los notéridos tienen preferencia por los hábitats lénticos y permanentes, de aguas dulces y turbias, ubicados en zonas bajas y soleadas con abundante vegetación acuática.The present work deals with the taxonomic composition, distribution, and bionomics of noterids from Cuba . Our research is based both on local and regional references on this family found in the literature, and on the identification of specimens collected from several localities of the country. We present a taxonomical list and a key to identify the species occurring in Cuba , along with their distribution regarding phytogeographic districts, and bionomical information. In Cuba , the family Noteridae is composed of five genera ( Hydrocanthus Say, Mesonoterus Sharp, Suphis Aubé , Suphisellus Crotch, and Notomicrus Sharp and 10 species, of which

  19. [Control of fertilization by self-incompatibility mechanisms].

    Science.gov (United States)

    Fobis-Loisy, Isabelle; Gaude, Thierry

    2010-01-01

    Flowering plants (angiosperms) are the most prevalent and evolutionarily advanced group of plants. Reproductive strategies that promote cross-fertilization have played an essential role in the success of angiosperms as they contribute to genetic variability among plant species. A major genetic barrier to self-fertilization is self-incompatibility (SI), which allows female reproductive cells to discriminate between self- and non-self pollen and specifically reject self-pollen. In this review, we describe three SI mechanisms showing that different flowering plant families use distinct molecules for recognition of self as well as diverse biochemical pathways to arrest pollen tube growth.

  20. 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.

  1. Composición taxonómica, distribución y bionomía de la familia Noteridae (Coleoptera: Adephaga en Cuba

    Directory of Open Access Journals (Sweden)

    Yoandri S. MEGNA

    2006-01-01

    Full Text Available La presente investigación analiza la composición taxonómica, distribución y bionomía de los notéridos registrados en Cuba, y se brinda una clave para su identificación. El estudio se realizó sobre la base de datos bibliográficos a nivel regional y nacional, así como del material colectado en diferentes localidades del país. Este trabajo permitió definir la lista de especies, su distribución por distritos fitogeográficos y los aspectos más generales de su bionomía. Se determinó que la familia Noteridae está compuesta por cinco géneros (Hydrocanthus Say, Mesonoterus Sharp, Suphis Aubé, Suphisellus Crotch y Notomicrus Sharp y 10 especies, de las cuales Suphisellus tenuicornis (Chevrolat es endémica, e Hydrocanthus advena Sharp no está confirmada. Las especies registradas están distribuidas en 11 (28,2% de los 39 distritos fitogeográficos establecidos. El distrito de mayor riqueza de especies es el No 15 (Planicie Centro-Occidental, con ocho especies. La especie más ampliamente distribuida es Notomicrus sharpi J. Balfour-Browne, reportada para seis (15,4% distritos. Los datos bionómicos muestran que los notéridos tienen preferencia por los hábitats lénticos y permanentes, de aguas dulces y turbias, ubicados en zonas bajas y soleadas con abundante vegetación acuática.

  2. 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.

  3. Vegetation of natural and artificial shorelines in Upper Klamath Basin’s fringe wetlands

    Science.gov (United States)

    Ray, Andrew M.; Irvine, Kathryn M.; Hamilton, Andy S.

    2013-01-01

    The Upper Klamath Basin (UKB) in northern California and southern Oregon supports large hypereutrophic lakes surrounded by natural and artificial shorelines. Lake shorelines contain fringe wetlands that provide key ecological services to the people of this region. These wetlands also provide a context for drawing inferences about how differing wetland types and wave exposure contribute to the vegetative assemblages in lake-fringe wetlands. Here, we summarize how elevation profiles and vegetation richness vary as a function of wave exposure and wetland type. Our results show that levee wetland shorelines are 4X steeper and support fewer species than other wetland types. We also summarize the occurrence probability of the five common wetland plant species that represent the overwhelming majority of the diversity of these wetlands. In brief, the occurrence probability of the culturally significant Nuphar lutea spp. polysepala and the invasive Phalaris arundinacea in wave exposed and sheltered sites varies based on wetland type. The occurrence probability for P. arundinacea was greatest in exposed portions of deltaic shorelines, but these trends were reversed on levees where the occurrence probability was greater in sheltered sites. The widespread Schoenoplectus acutus var. acutus occurred throughout all wetland and exposure type combinations but had a higher probability of occurrence in wave exposed sites. Results from this work will add to our current understanding of how wetland shoreline profiles interact with wave exposure to influence the occurrence probability of the dominant vegetative species in UKB’s shoreline wetlands.

  4. Microscopic fungi on Nymphaeaceae plants of the Lake Płociczno in Drawa National Park (NW Poland

    Directory of Open Access Journals (Sweden)

    Kinga Mazurkiewicz-Zapałowicz

    2016-07-01

    Full Text Available The aim of this study was to determine the occurrence of micromycetes associated with disease symptoms on the leaves and flowers of three plant species, Nymphaea alba (NA, Nymphaea candida (NC, and Nuphar lutea (NL, forming nympheid phytocoenoses on Lake Płociczno in Drawa National Park during the years 2009 to 2012. From all collected plant specimens, an overall number of 38 distinct taxa of fungi and chromistan fungal analogues was isolated. The largest diversity of taxa was found on NL (37 taxa, the lowest was on NC (4 taxa, and NA contained 12 taxa. Each year, anamorphic forms of Ascomycota were dominant in the taxonomic structure. For the first time in Poland, Septoria nupharis (NA, NL, NC and Colletotrichum nymphaeae (NL, NC were found on their spotted leaves. For both of the mentioned pathogens, Nymphaea candida is a new host plant in Poland. Botrytis cinerea, Elongisporangium undulatum (= Pythium undulatum, Epicoccum nigrum, Fusarium incarnatum (= F. semitectum, and Gibberella avenacea (= Fusarium avenaceum were found each year in the studied phytocoenoses. The confirmation of NA and NL flower infections by Botrytis cinerea, which leads to gangrene, is an important aspect of the gray mold epidemiology. Until now, the occurrence of smut fungi on nympheids in Drawa National Park was not observed. The taxonomic structure and the predomination of asexual stages of fungi, as well as the similarity coefficients, suggest that the seasonal decomposition of nympheids run naturally and contribute to maintaining the stability of the lake ecosystem.

  5. 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...

  6. Hydrogel Regulation of Xylem Water Flow: An Alternative Hypothesis

    NARCIS (Netherlands)

    Doorn, van W.G.; Hiemstra, T.; Fanourakis, D.

    2011-01-01

    The concentration of cations in the xylem sap influences the rate of xylem water flow in angiosperm plants. It has been speculated that this is due to the shrinking and swelling of pectins in the pit membranes. However, there is as yet minimal evidence for the presence of pectin in pit membranes of

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

    NARCIS (Netherlands)

    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

  8. 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

    , 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...

  9. Review

    NARCIS (Netherlands)

    Kalkman, C.

    1996-01-01

    The book contains 411 colour photographs of as many plant species (all Angiosperms). I estimate that about half of the species covered is not native to Sri Lanka, but introduced and sometimes run wild. That means that the pictures are highly representative for what one meets as a resident or as a vi

  10. The Winteraceae of the Old World. I. Pseudowintera and Drimys — Morphology and taxonomy

    NARCIS (Netherlands)

    Vink, W.

    1970-01-01

    The primitive woody Angiosperm family Winteraceae is centred in the southwest Pacific, has an outpost in Madagascar (1 species), and a section of Drimys (4 species) in the New World. Pseudowintera is restricted to New Zealand, the Old World section Tasmannia of Drimys extends from the Philippines to

  11. 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...

  12. 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

  13. 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...

  14. 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

  15. 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 cis-Elements) conserved among the Arabidopsis thaliana A7 (AtEXPA7) orthologous (and paralogous) genes from diver...se angiosperm species with different hair distribution patterns; K=G/T; W=T/A; root; hair; Arabidopsis thaliana KCACGW ...

  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. Cryopreservation of fern spores

    Science.gov (United States)

    Spore banks for ferns are analogous to seed banks for angiosperms and provide a promising ex situ conservation tool because large quantities of germplasm with high genetic variation can be conserved in a small space with low economic and technical costs. Ferns produce two types of spores with very ...

  18. The effects of climate stability on northern temperate forests

    DEFF Research Database (Denmark)

    Ma, Ziyu

    2016-01-01

    refugia have served as both museums and cradles for old and new species, respectively. Moreover, comparing gymnosperm to angiosperm trees in North America, I found that gymnosperm phylogenetic diversity patterns were more linked to historical than to current climate. However, I also documented effects...

  19. Bicarbonate utilization and pH polarity. The response of photosynthetic electron transport to carbon limitation in Potamogeton lucens leaves

    NARCIS (Netherlands)

    van Ginkel, LC; Prins, HBA

    1998-01-01

    By the process of pH polarity, several submersed angiosperms can use bicarbonate as carbon source for photosynthesis. Under conditions of relatively high light intensity and low CO2 availability, the pH of the apoplast and unstirred layer becomes acid at one side of the leaf and alkaline at the othe

  20. A CO2-flux mechanism operating via pH-polarity in Hydrilla verticillata leaves with C-3 and C-4 photosynthesis

    NARCIS (Netherlands)

    van Ginkel, LC; Bowes, G; Reiskind, JB; Prins, HBA

    2001-01-01

    The aquatic angiosperm Hydrilla verticillata lacks Kranz anatomy, but has an inducible, C-4-based, CO2 concentrating mechanism (CCM) that concentrates CO2 in the chloroplasts. Both C-3 and C-4 Hydrilla leaves showed light-dependent pH polarity that was suppressed by high dissolved inorganic carbon (

  1. 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...

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

    DEFF Research Database (Denmark)

    Lundqvist, A.; Østerbye, U.; Larsen, K.;

    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...

  3. 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.

  4. 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...

  5. 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.

  6. 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...

  7. 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

  8. Regulation of pollen tube polarity: Feedback loops rule

    Science.gov (United States)

    Targeted delivery of immotile sperm through growing pollen tubes is a crucial step in achieving sexual reproduction in angiosperms. Unlike diffuse-growing cells, the growth of a pollen tube is restricted to the very apical region where targeted exocytosis and regulated endocytosis occur. The plant-s...

  9. 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.

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

    Science.gov (United States)

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

    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 phenology and pollination ecology of the Australian endemic species Pseuduvaria mulgraveana are studied in detail, including evaluations of floral scent chemistry, pollen viability, and floral visitors. Results showed that the flowers are pollinated by small diurnal nitidulid beetles and are protogynous. Pollen from both hermaphroditic and staminate flowers are shown to be equally viable. The structurally hermaphroditic flowers are nevertheless functionally pistillate as anther dehiscence is delayed until after petal abscission and hence after the departure of pollinators. This mechanism to achieve functional unisexuality of flowers has not previously been reported in angiosperms. It is known that protogyny is widespread amongst early-divergent angiosperms, including the Annonaceae, and is effective in preventing autogamy. Delayed anther dehiscence represents a further elaboration of this, and is effective in preventing geitonogamy since very few sexually mature flowers occur simultaneously in an individual. We highlight the necessity for field-based empirical interpretations of functional floral sex expression prior to evaluations of evolutionary processes.

  11. Chromosome numbers of some Angiospermae collected in Cameroun and the Ivory Coast II

    NARCIS (Netherlands)

    Gadella, Th.W.J.

    1970-01-01

    The chromosome number of 15 species of Angiosperms, occurring in Cameroun and the Ivory Coast, was determined. The numbers given for 11 species are new, for three species the results of previous studies could be confirmed, whereas in one species the presence of intraspecific polyploidy could be demo

  12. A Phylogeny of the Monocots, as Inferred from rbcL and atpA Sequence Variation, and a Comparison of Methods for Calculating Jackknife and Bootstrap Values

    DEFF Research Database (Denmark)

    Davis, Jerrold I.; Stevenson, Dennis W.; Petersen, Gitte;

    2004-01-01

    A phylogenetic analysis of the monocots was conducted on the basis of nucleotide sequence variation in two genes (atpA, encoded in the mitochondrial genome, and rbcL, encoded in the plastid genome). The taxon sample of 218 angiosperm terminals included 177 monocots and 41 dicots. Among the major ...

  13. Hypergravity prevents seed production in Arabidopsis by disrupting pollen tube growth

    NARCIS (Netherlands)

    M.E. Musgrave; A.X. Kuang; J. Allen; J.J.W.A. van Loon

    2009-01-01

    How tightly land plants are adapted to the gravitational force (g) prevailing on Earth has been of interest because unlike many other environmental factors, g presents as a constant force. Ontogeny of mature angiosperms begins with an embryo that is formed after tip growth by a pollen tube delivers

  14. 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.

  15. Ethyl ester purpurine-18 from Gossypium mustelinum (Malvaceae);Feoforbideo (etoxi-purpurina-18) isolado de Gossypium mustelinum (Malvaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Tania Maria Sarmento; Camara, Celso Amorim, E-mail: taniasarmento@dq.ufrpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Quimica; Barbosa-Filho, Jose Maria [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Lab. de Tecnologia Farmaceutica; Giulietti, Ana Maria [Universidade Estadual de Feira de Santana, BA (Brazil). Dept. de Ciencias Biologicas

    2010-07-01

    The phaeophorbide ethyl ester named Purpurine-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. (author)

  16. 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

  17. 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.…

  18. 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.

  19. Diverse functions of KNOX transcription factors in the diploid body plan of plants

    Science.gov (United States)

    KNOX genes were initially found as shoot meristem regulators in angiosperms. Recent studies in diverse plant lineages however, have revealed the divergence of KNOX gene function during the evolution of diploid body plans. Using genomic approaches, class I KNOX transcription factors have been shown t...

  20. Nutrient dynamics in Indonesian seagrass beds : factors determining conservation and loss of nitrogen and phosp[h]orus

    NARCIS (Netherlands)

    Stapel, J.

    1997-01-01

    Seagrasses are marine angiosperms that occur in shallow coastal seas around the world. They have reached their highest species diversity in Southeast Asia, where they formextensive multi-species meadows. The seagrass beds in Indonesia maintain a high productivity despite a low nu

  1. 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),...

  2. Dynamics and evolution of the inverted repeat-large single copy junctions in the chloroplast genomes of monocots

    Directory of Open Access Journals (Sweden)

    Wu Chun-Lin

    2008-01-01

    Full Text Available Abstract Background Various expansions or contractions of inverted repeats (IRs in chloroplast genomes led to fluxes in the IR-LSC (large single copy junctions. Previous studies revealed that some monocot IRs contain a trnH-rps19 gene cluster, and it has been speculated that this may be an evidence of a duplication event prior to the divergence of monocot lineages. Therefore, we compared the organizations of genes flanking two IR-LSC junctions in 123 angiosperm representatives to uncover the evolutionary dynamics of IR-LSC junctions in basal angiosperms and monocots. Results The organizations of genes flanking IR-LSC junctions in angiosperms can be classified into three types. Generally each IR of monocots contains a trnH-rps19 gene cluster near the IR-LSC junctions, which differs from those in non-monocot angiosperms. Moreover, IRs expanded more progressively in monocots than in non-monocot angiosperms. IR-LSC junctions commonly occurred at polyA tract or A-rich regions in angiosperms. Our RT-PCR assays indicate that in monocot IRA the trnH-rps19 gene cluster is regulated by two opposing promoters, S10A and psbA. Conclusion Two hypotheses are proposed to account for the evolution of IR expansions in monocots. Based on our observations, the inclusion of a trnH-rps19 cluster in majority of monocot IRs could be reasonably explained by the hypothesis that a DSB event first occurred at IRB and led to the expansion of IRs to trnH, followed by a successive DSB event within IRA and lead to the expansion of IRs to rps19 or to rpl22 so far. This implies that the duplication of trnH-rps19 gene cluster was prior to the diversification of extant monocot lineages. The duplicated trnH genes in the IRB of most monocots and non-monocot angiosperms have distinct fates, which are likely regulated by different expression levels of S10A and S10B promoters. Further study is needed to unravel the evolutionary significance of IR expansion in more recently diverged

  3. 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

  4. 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

  5. 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

  6. 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

  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. 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.

  9. 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

  10. 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

  11. 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.

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

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    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.

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

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    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.

  14. 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

    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...... 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...... in ground tissues. Mannan epitopes were found to be associated with the development of mechanical tissues. We provided the first evidence for the presence of MLG in leptosporangiate ferns. Conclusions: The data sets indicate that cell wall diversity in land plants is multifaceted and that matrix glycan...

  15. Longitudinal zonation pattern in plant roots: conflicts and solutions.

    Science.gov (United States)

    Ivanov, Victor B; Dubrovsky, Joseph G

    2013-05-01

    Despite the relative simplicity of Arabidopsis root organization, there is no general agreement regarding the terminology used to describe the longitudinal zonation pattern (LZP) of this model system. In this opinion article, we examine inconsistencies in the terminology and provide a conceptual framework for the LZP that may be applied to all angiosperms. We propose that the root apical meristem (RAM) consists of the cell-proliferation domain where cells maintain a high probability to divide and the transition domain with a low probability of cell division; in both domains cells grow at the same, relatively low, rate. Owing to stochastic termination of cell proliferation in the RAM, the border between the domains is 'fuzzy'. Molecular markers analyzed together with quantitative growth and cell analyses could help to identify developmental zones along the root and lead to a better understanding of the LZP in angiosperms.

  16. On the origin and evolutionary consequences of gene body DNA methylation.

    Science.gov (United States)

    Bewick, Adam J; Ji, Lexiang; Niederhuth, Chad E; Willing, Eva-Maria; Hofmeister, Brigitte T; Shi, Xiuling; Wang, Li; Lu, Zefu; Rohr, Nicholas A; Hartwig, Benjamin; Kiefer, Christiane; Deal, Roger B; Schmutz, Jeremy; Grimwood, Jane; Stroud, Hume; Jacobsen, Steven E; Schneeberger, Korbinian; Zhang, Xiaoyu; Schmitz, Robert J

    2016-08-01

    In plants, CG DNA methylation is prevalent in the transcribed regions of many constitutively expressed genes (gene body methylation; gbM), but the origin and function of gbM remain unknown. Here we report the discovery that Eutrema salsugineum has lost gbM from its genome, to our knowledge the first instance for an angiosperm. Of all known DNA methyltransferases, only CHROMOMETHYLASE 3 (CMT3) is missing from E. salsugineum Identification of an additional angiosperm, Conringia planisiliqua, which independently lost CMT3 and gbM, supports that CMT3 is required for the establishment of gbM. Detailed analyses of gene expression, the histone variant H2A.Z, and various histone modifications in E. salsugineum and in Arabidopsis thaliana epigenetic recombinant inbred lines found no evidence in support of any role for gbM in regulating transcription or affecting the composition and modification of chromatin over evolutionary timescales.

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

    Directory of Open Access Journals (Sweden)

    W. John Calder

    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.

  18. 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.

  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...... 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. 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

  1. Monolignol ferulate conjugates are naturally incorporated into plant lignins

    Science.gov (United States)

    Karlen, Steven D.; Zhang, Chengcheng; Peck, Matthew L.; Smith, Rebecca A.; Padmakshan, Dharshana; Helmich, Kate E.; Free, Heather C. A.; Lee, Seonghee; Smith, Bronwen G.; Lu, Fachuang; Sedbrook, John C.; Sibout, Richard; Grabber, John H.; Runge, Troy M.; Mysore, Kirankumar S.; Harris, Philip J.; Bartley, Laura E.; Ralph, John

    2016-01-01

    Angiosperms represent most of the terrestrial plants and are the primary research focus for the conversion of biomass to liquid fuels and coproducts. Lignin limits our access to fibers and represents a large fraction of the chemical energy stored in plant cell walls. Recently, the incorporation of monolignol ferulates into lignin polymers was accomplished via the engineering of an exotic transferase into commercially relevant poplar. We report that various angiosperm species might have convergently evolved to natively produce lignins that incorporate monolignol ferulate conjugates. We show that this activity may be accomplished by a BAHD feruloyl–coenzyme A monolignol transferase, OsFMT1 (AT5), in rice and its orthologs in other monocots. PMID:27757415

  2. 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...

  3. 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...

  4. 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...

  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. A New Symmetrodont Mammal with Fur Impressions from the Mesozoic of China

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Western Liaoning of northeastern China is world-renowned for the Mesozoic Jehol biota, especially for yielding many feathered dinosaurs, primitive birds, mammals and fossil angiosperm. This paper describes a complete specimen of a symmetrodont mammal with well-preserved hairs and soft tissue from the basal part of the Yixian Formation in the Sihetun area, Beipiao, western Liaoning. It is significant for understanding the morphology, osteology, phylogeny and life habits of Mesozoic symmetrodont mammals.

  7. 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 ...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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.

  13. Analysis of Acorus calamus chloroplast genome and its phylogenetic implications.

    Science.gov (United States)

    Goremykin, Vadim V; Holland, Barbara; Hirsch-Ernst, Karen I; Hellwig, Frank H

    2005-09-01

    Determining the phylogenetic relationships among the major lines of angiosperms is a long-standing problem, yet the uncertainty as to the phylogenetic affinity of these lines persists. While a number of studies have suggested that the ANITA (Amborella-Nymphaeales-Illiciales-Trimeniales-Aristolochiales) grade is basal within angiosperms, studies of complete chloroplast genome sequences also suggested an alternative tree, wherein the line leading to the grasses branches first among the angiosperms. To improve taxon sampling in the existing chloroplast genome data, we sequenced the chloroplast genome of the monocot Acorus calamus. We generated a concatenated alignment (89,436 positions for 15 taxa), encompassing almost all sequences usable for phylogeny reconstruction within spermatophytes. The data still contain support for both the ANITA-basal and grasses-basal hypotheses. Using simulations we can show that were the ANITA-basal hypothesis true, parsimony (and distance-based methods with many models) would be expected to fail to recover it. The self-evident explanation for this failure appears to be a long-branch attraction (LBA) between the clade of grasses and the out-group. However, this LBA cannot explain the discrepancies observed between tree topology recovered using the maximum likelihood (ML) method and the topologies recovered using the parsimony and distance-based methods when grasses are deleted. Furthermore, the fact that neither maximum parsimony nor distance methods consistently recover the ML tree, when according to the simulations they would be expected to, when the out-group (Pinus) is deleted, suggests that either the generating tree is not correct or the best symmetric model is misspecified (or both). We demonstrate that the tree recovered under ML is extremely sensitive to model specification and that the best symmetric model is misspecified. Hence, we remain agnostic regarding phylogenetic relationships among basal angiosperm lineages.

  14. 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...

  15. 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...

  16. 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...

  17. 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 ...

  18. 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...

  19. Influence of arbuscular mycorrhizal fungi and the expression of K+/Cs+ transporters on the accumulation of caesium by plants

    OpenAIRE

    Wiesel, Lea

    2011-01-01

    Radiocaesium (134Cs, 137Cs) is of environmental concern because of its incorporation into the food chain and prolonged emission of harmful radiation. Plants take up caesium via cation transporters which cannot discriminate between radioactive and stable caesium (133Cs). Around 80% of angiosperms live in symbiosis with arbuscular mycorrhizal (AM) fungi that deliver mineral nutrients to their hosts. Contrasting effects of AM fungi on caesium accumulation by plants have been reported. The ultima...

  20. 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...

  1. 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...

  2. 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 ...

  3. 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...

  4. 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...

  5. 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.

  6. 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...

  7. 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...

  8. Chemical structural studies of natural lignin by dipolar dephasing solid-state 13C nuclear magnetic resonance

    Science.gov (United States)

    Hatcher, P.G.

    1987-01-01

    Two natural lignins, one from a gymnosperm wood the other from angiosperm wood, were examined by conventional solid-state and dipolar dephasing 13C nuclear magnetic resonance (NMR) techniques. The results obtained from both techniques show that the structure of natural lignins is consistent with models of softwood and hardwood lignin. The dipolar dephasing NMR data provide a measure of the degree of substitution on aromatic rings which is consistent with the models. ?? 1987.

  9. 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...

  10. 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...

  11. 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 ...

  12. 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.

  13. 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...

  14. 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...

  15. 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, ...

  16. 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...

  17. 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...

  18. 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...

  19. 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.

  20. 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...

  1. 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, ...

  2. 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, ...

  3. 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...

  4. 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...

  5. Tension wood and opposite wood in 21 tropical rain forest species. 1. Occurence and efficiency of G-layer

    OpenAIRE

    Clair, Bruno; Ruelle, Julien; Beauchêne, Jacques; Prévost, Marie-Françoise; Fournier, Meriem

    2006-01-01

    Wood samples were taken from the upper and lower sides of 21 naturally tilted trees from 18 families of angiosperms in the tropical rainforest in French Guyana. The measurement of growth stresses ensured that the two samples were taken from wood tissues in a different mechanical state: highly tensile stressed wood on the upper side, called tension wood and lower tensile stressed wood on the lower side, called opposite wood. Eight species had tension wood fibres with a distinct gelatinous laye...

  6. 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...

  7. 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...

  8. 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

  9. 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...

  10. 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.

  11. 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.

  12. 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

  13. 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.

  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 and genetics of root hair stripes in the root epidermis.

    Science.gov (United States)

    Dolan, L; Costa, S

    2001-03-01

    Root hair pattern develops in a number of different ways in angiosperm. Cells in the epidermis of some species undergo asymmetric cell divisions to form a smaller daughter cell from which a hair grows, and a larger cell that forms a non-hair epidermal cell. In other species any cell in the epidermis can form a root hair. Hair cells are arranged in files along the Arabidopsis root, located in the gaps between underlying cortical cell files. Epidermal cells overlying a single cortical cell file develop as non-hair epidermal cells. Genetic analysis has identified a transcription factor cascade required for the formation of this pattern. WEREWOLF (WER) and GLABRA2 (GL2) are required for the formation of non-hair epidermal cells while CAPRICE (CPC) is required for hair cell development. Recent analyses of the pattern of epidermal cells among the angiosperms indicate that this striped pattern of cell organization evolved from non-striped ancestors independently in a number of diverse evolutionary lineages. The genetic basis for the evolution of epidermal pattern in angiosperms may now be examined.

  16. 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

  17. 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

  18. 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.

  19. 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

  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.

  1. Gravitropisms and reaction woods of forest trees - evolution, functions and mechanisms.

    Science.gov (United States)

    Groover, Andrew

    2016-08-01

    Contents 790 I. 790 II. 792 III. 795 IV. 797 V. 798 VI. 800 VII. 800 800 References 800 SUMMARY: The woody stems of trees perceive gravity to determine their orientation, and can produce reaction woods to reinforce or change their position. Together, graviperception and reaction woods play fundamental roles in tree architecture, posture control, and reorientation of stems displaced by wind or other environmental forces. Angiosperms and gymnosperms have evolved strikingly different types of reaction wood. Tension wood of angiosperms creates strong tensile force to pull stems upward, while compression wood of gymnosperms creates compressive force to push stems upward. In this review, the general features and evolution of tension wood and compression wood are presented, along with descriptions of how gravitropisms and reaction woods contribute to the survival and morphology of trees. An overview is presented of the molecular and genetic mechanisms underlying graviperception, initial graviresponse and the regulation of tension wood development in the model angiosperm, Populus. Critical research questions and new approaches are discussed.

  2. 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.

  3. 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.

  4. Putative floral brood-site mimicry, loss of autonomous selfing, and reduced vegetative growth are significantly correlated with increased diversification in Asarum (Aristolochiaceae).

    Science.gov (United States)

    Sinn, Brandon T; Kelly, Lawrence M; Freudenstein, John V

    2015-08-01

    The drivers of angiosperm diversity have long been sought and the flower-arthropod association has often been invoked as the most powerful driver of the angiosperm radiation. We now know that features that influence arthropod interactions cannot only affect the diversification of lineages, but also expedite or constrain their rate of extinction, which can equally influence the observed asymmetric richness of extant angiosperm lineages. The genus Asarum (Aristolochiaceae; ∼100 species) is widely distributed in north temperate forests, with substantial vegetative and floral divergence between its three major clades, Euasarum, Geotaenium, and Heterotropa. We used Binary-State Speciation and Extinction Model (BiSSE) Net Diversification tests of character state distributions on a Maximum Likelihood phylogram and a Coalescent Bayesian species tree, inferred from seven chloroplast markers and nuclear rDNA, to test for signal of asymmetric diversification, character state transition, and extinction rates of floral and vegetative characters. We found that reduction in vegetative growth, loss of autonomous self-pollination, and the presence of putative fungal-mimicking floral structures are significantly correlated with increased diversification in Asarum. No significant difference in model likelihood was identified between symmetric and asymmetric rates of character state transitions or extinction. We conclude that the flowers of the Heterotropa clade may have converged on some aspects of basidiomycete sporocarp morphology and that brood-site mimicry, coupled with a reduction in vegetative growth and the loss of autonomous self-pollination, may have driven diversification within Asarum.

  5. 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.

  6. Floral adaptation and diversification under pollen limitation.

    Science.gov (United States)

    Harder, Lawrence D; Aizen, Marcelo A

    2010-02-12

    Pollen limitation (PL) of seed production creates unique conditions for reproductive adaptation by angiosperms, in part because, unlike under ovule or resource limitation, floral interactions with pollen vectors can contribute to variation in female success. Although the ecological and conservation consequences of PL have received considerable attention in recent times, its evolutionary implications are poorly appreciated. To identify general influences of PL on reproductive adaptation compared with those under other seed-production limits and their implications for evolution in altered environments, we derive a model that incorporates pollination and post-pollination aspects of PL. Because PL always favours increased ovule fertilization, even when population dynamics are not seed limited, it should pervasively influence selection on reproductive traits. Significantly, under PL the intensity of inbreeding does not determine whether outcrossing or autonomous selfing can evolve, although it can affect which response is most likely. Because the causes of PL are multifaceted in both natural and anthropogenically altered environments, the possible outcrossing solutions are diverse and context dependent, which may contribute to the extensive variety of angiosperm reproductive characteristics. Finally, the increased adaptive options available under PL may be responsible for positive global associations between it and angiosperm diversity. PMID:20047878

  7. 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.

  8. 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

  9. 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

  10. The role of fire in deep time ecosystems

    Science.gov (United States)

    Scott, Andrew C.; Bond, William J.; Collinson, Margaret E.; Glasspool, Ian J.; Brown, Sarah; Braman, Dennis R.

    2010-05-01

    Fires are very widespread in the world today and fire has also been common in the deep past. Fire is important in structuring contemporary World vegetation maintaining extensive open vegetation where the climate has the potential to support closed forests. The influence of fire on the structure of vegetation and plant traits present in a community vary depending on the fire regime. The fire regime is the characteristic pattern of fire frequency, severity (amount of biomass removed) and spatial extent. Fire regimes depend on the synergy between external physical factors and the properties of vegetation. Changes in the fire regime can be brought about by changes in external conditions such as climate, but also by changes in vegetation such as changes in flammability or productivity that influence the amount of fuel. For example, invasion of grasses into closed wooded habitats has initiated a ‘grass fire cycle' in many parts of the world triggering cascading changes in vegetation structure and composition from forest to open grassland or savanna woodland. The spread of flammable invasive species, especially grasses, has even altered fire regimes of fire-dependent flammable communities causing catastrophic ecosystem changes. We suggest that the spread of angiosperms in the Cretaceous was promoted by the development of novel fire regimes linked to the evolution of novel, highly productive (and flammable) plants. Within the limits of physical constraints on fire occurrence, Cretaceous angiosperms would have initiated a positive feedback analogous to the grass-fire cycle rapidly accumulating fuel that promoted more frequent fires, which maintained open habitats in which rapid growth-traits of angiosperms would be most favoured promoting rapid fuel accumulation etc. Frequent fires would have altered vegetation structure and composition both by increasing mortality rates of fire-damaged trees and reducing recruitment rates of seedlings and saplings where fires recurred

  11. The adaptive value of shoot differentiation in deciduous trees and its evolutionary relevance Valor adaptativo de la diferenciación de brotes en árboles deciduos y su relevancia evolutiva

    Directory of Open Access Journals (Sweden)

    Veit M. Dörken

    2009-12-01

    Full Text Available Pronounced long shoot/short shoot differentiation is typical for deciduous angiosperm trees. It also occurs in a number of gymnosperms and very few evergreen angiosperm trees. The study of 719 angiosperm tree species (602 deciduous and 117 evergreen species demonstrated that the deciduous condition is nearly always associated with shoot differentiation. Detailed measurements in 38 angiosperms showed that the leaf area of an entire short shoot equals the leaf area of a single long shoot leaf of the same species and individual. In the few cases where the leaf area of the short shoot is slightly larger than that of a single long-shoot leaf, the short shoot leaves shade each other and the projection of the short shoot equals the area of a single long shoot leaf. Calculations of the stem biomass needed to expose a given assimilatory surface show two interesting aspects. First, the stem biomass (dry weight to expose leaf surface is about 10 times less in short shoots than in long shoots. Second, this biomass in long shoots and short shoots appears to be species independent. Regarding shoot structure efficiency, leaf size and shape do not matter. Some evergreen species resemble in all parameters more to deciduous species than to typical evergreen species. Phytogeographical data as well as morphological data suggest that these atypical evergreen species are derived from deciduous ancestors. As measured parameters differ markedly between all gymnosperms, except Ginkgo, and angiosperms, we suppose that the evolutionary pathway leading to shoot differentiation was different for gymnosperms and angiosperms.En Angiospermas arbóreas deciduas, es común encontrar un alto grado de diferenciación entre brotes largos y brotes cortos. También se presenta esta característica en un número de gimnospermas y en muy pocas angiospermas arbóreas siempreverdes. El estudio de 719 especies de angiospermas arbóreas (602 deciduas y 117 siempreverdes demostró que la

  12. 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.

  13. Comparative analysis of the small RNA transcriptomes of Pinus contorta and Oryza sativa.

    Science.gov (United States)

    Morin, Ryan D; Aksay, Gozde; Dolgosheina, Elena; Ebhardt, H Alexander; Magrini, Vincent; Mardis, Elaine R; Sahinalp, S Cenk; Unrau, Peter J

    2008-04-01

    The diversity of microRNAs and small-interfering RNAs has been extensively explored within angiosperms by focusing on a few key organisms such as Oryza sativa and Arabidopsis thaliana. A deeper division of the plants is defined by the radiation of the angiosperms and gymnosperms, with the latter comprising the commercially important conifers. The conifers are expected to provide important information regarding the evolution of highly conserved small regulatory RNAs. Deep sequencing provides the means to characterize and quantitatively profile small RNAs in understudied organisms such as these. Pyrosequencing of small RNAs from O. sativa revealed, as expected, approximately 21- and approximately 24-nt RNAs. The former contained known microRNAs, and the latter largely comprised intergenic-derived sequences likely representing heterochromatin siRNAs. In contrast, sequences from Pinus contorta were dominated by 21-nt small RNAs. Using a novel sequence-based clustering algorithm, we identified sequences belonging to 18 highly conserved microRNA families in P. contorta as well as numerous clusters of conserved small RNAs of unknown function. Using multiple methods, including expressed sequence folding and machine learning algorithms, we found a further 53 candidate novel microRNA families, 51 appearing specific to the P. contorta library. In addition, alignment of small RNA sequences to the O. sativa genome revealed six perfectly conserved classes of small RNA that included chloroplast transcripts and specific types of genomic repeats. The conservation of microRNAs and other small RNAs between the conifers and the angiosperms indicates that important RNA silencing processes were highly developed in the earliest spermatophytes. Genomic mapping of all sequences to the O. sativa genome can be viewed at http://microrna.bcgsc.ca/cgi-bin/gbrowse/rice_build_3/.

  14. 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.

  15. Evolving Ideas on the Origin and Evolution of Flowers: New Perspectives in the Genomic Era.

    Science.gov (United States)

    Chanderbali, Andre S; Berger, Brent A; Howarth, Dianella G; Soltis, Pamela S; Soltis, Douglas E

    2016-04-01

    The origin of the flower was a key innovation in the history of complex organisms, dramatically altering Earth's biota. Advances in phylogenetics, developmental genetics, and genomics during the past 25 years have substantially advanced our understanding of the evolution of flowers, yet crucial aspects of floral evolution remain, such as the series of genetic and morphological changes that gave rise to the first flowers; the factors enabling the origin of the pentamerous eudicot flower, which characterizes ∼70% of all extant angiosperm species; and the role of gene and genome duplications in facilitating floral innovations. A key early concept was the ABC model of floral organ specification, developed by Elliott Meyerowitz and Enrico Coen and based on two model systems,Arabidopsis thalianaandAntirrhinum majus Yet it is now clear that these model systems are highly derived species, whose molecular genetic-developmental organization must be very different from that of ancestral, as well as early, angiosperms. In this article, we will discuss how new research approaches are illuminating the early events in floral evolution and the prospects for further progress. In particular, advancing the next generation of research in floral evolution will require the development of one or more functional model systems from among the basal angiosperms and basal eudicots. More broadly, we urge the development of "model clades" for genomic and evolutionary-developmental analyses, instead of the primary use of single "model organisms." We predict that new evolutionary models will soon emerge as genetic/genomic models, providing unprecedented new insights into floral evolution.

  16. Identification and Functional Characterization of Monofunctional ent-Copalyl Diphosphate and ent-Kaurene Synthases in White Spruce Reveal Different Patterns for Diterpene Synthase Evolution for Primary and Secondary Metabolism in Gymnosperms1[W][OA

    Science.gov (United States)

    Keeling, Christopher I.; Dullat, Harpreet K.; Yuen, Mack; Ralph, Steven G.; Jancsik, Sharon; Bohlmann, Jörg

    2010-01-01

    The biosynthesis of the tetracyclic diterpene ent-kaurene is a critical step in the general (primary) metabolism of gibberellin hormones. ent-Kaurene is formed by a two-step cyclization of geranylgeranyl diphosphate via the intermediate ent-copalyl diphosphate. In a lower land plant, the moss Physcomitrella patens, a single bifunctional diterpene synthase (diTPS) catalyzes both steps. In contrast, in angiosperms, the two consecutive cyclizations are catalyzed by two distinct monofunctional enzymes, ent-copalyl diphosphate synthase (CPS) and ent-kaurene synthase (KS). The enzyme, or enzymes, responsible for ent-kaurene biosynthesis in gymnosperms has been elusive. However, several bifunctional diTPS of specialized (secondary) metabolism have previously been characterized in gymnosperms, and all known diTPSs for resin acid biosynthesis in conifers are bifunctional. To further understand the evolution of ent-kaurene biosynthesis as well as the evolution of general and specialized diterpenoid metabolisms in gymnosperms, we set out to determine whether conifers use a single bifunctional diTPS or two monofunctional diTPSs in the ent-kaurene pathway. Using a combination of expressed sequence tag, full-length cDNA, genomic DNA, and targeted bacterial artificial chromosome sequencing, we identified two candidate CPS and KS genes from white spruce (Picea glauca) and their orthologs in Sitka spruce (Picea sitchensis). Functional characterization of the recombinant enzymes established that ent-kaurene biosynthesis in white spruce is catalyzed by two monofunctional diTPSs, PgCPS and PgKS. Comparative analysis of gene structures and enzyme functions highlights the molecular evolution of these diTPSs as conserved between gymnosperms and angiosperms. In contrast, diTPSs for specialized metabolism have evolved differently in angiosperms and gymnosperms. PMID:20044448

  17. 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.

  18. 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...

  19. New Combinations for ChineseArgentina Hill (Rosaceae)%中国蔷薇科蕨麻属新组合

    Institute of Scientific and Technical Information of China (English)

    童毅华; 夏念和

    2016-01-01

    During the course of compilingSpecies Catalogue of China [Volume I-Spermatophytes, (V)-Angiosperms (Rosaceae–Phyllanthaceae)], twelve new combinations for ChineseArgentina Hill (Rosaceae) are proposed here based on the recent studies.%在编研《中国生物物种名录》第一卷第五分册(蔷薇科–叶下珠科)的过程中,根据最新的研究结果提出国产蔷薇科蕨麻属植物的12个新组合。

  20. Plant macrofossils of the upper Cretaceous Kaitangata coalfield, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Pole, M.; Douglas, B. [University of Queensland, Brisbane, Qld. (Australia). Dept. of Botany

    1999-08-15

    Uppermost Cretaceous sediments from the Cretaceous Kaitangata Coal Mine and the Wangaloa coast (south of Dunedin, New Zealand) were investigated for dispersed plant macrofossils. The gymnosperms include two cycads (Macrozamia sp. and Pterostoma sp.), Ginkgo sp., three further possible ginkgophyte taxa, and ten conifer taxa. The conifers include two new conifer genera and species, Maikuku stephaniae and Ware riderensis, which are placed in the Taxodiaceae s.l. There are also 13 types of angiosperm cuticle. Sample heterogeneity as regards taxa present and their abundance suggests taxonomic heterogeneity in the original vegetation.

  1. Pollen limitation may be a common Allee effect in marine hydrophilous plants: implications for decline and recovery in seagrasses.

    Science.gov (United States)

    Van Tussenbroek, B I; Soissons, L M; Bouma, T J; Asmus, R; Auby, I; Brun, F G; Cardoso, P G; Desroy, N; Fournier, J; Ganthy, F; Garmendia, J M; Godet, L; Grilo, T F; Kadel, P; Ondiviela, B; Peralta, G; Recio, M; Valle, M; Van der Heide, T; Van Katwijk, M M

    2016-10-01

    Pollen limitation may be an important factor in accelerated decline of sparse or fragmented populations. Little is known whether hydrophilous plants (pollen transport by water) suffer from an Allee effect due to pollen limitation or not. Hydrophilous pollination is a typical trait of marine angiosperms or seagrasses. Although seagrass flowers usually have high pollen production, floral densities are highly variable. We evaluated pollen limitation for intertidal populations of the seagrass Zostera noltei in The Netherlands and found a significant positive relation between flowering spathe density and fruit-set, which was suboptimal at seagrasses, potentially accelerating decline and impairing recovery even after environmental conditions have improved substantially. PMID:27272209

  2. 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.

  3. 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...

  4. 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...

  5. 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.

  6. 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

  7. Economic strategies of plant absorptive roots vary with root diameter

    Science.gov (United States)

    Kong, D. L.; Wang, J. J.; Kardol, P.; Wu, H. F.; Zeng, H.; Deng, X. B.; Deng, Y.

    2016-01-01

    Plant roots typically vary along a dominant ecological axis, the root economics spectrum, depicting a tradeoff between resource acquisition and conservation. For absorptive roots, which are mainly responsible for resource acquisition, we hypothesized that root economic strategies differ with increasing root diameter. To test this hypothesis, we used seven plant species (a fern, a conifer, and five angiosperms from south China) for which we separated absorptive roots into two categories: thin roots (thickness of root cortex plus epidermis perspective on our understanding of the root economics spectrum.

  8. Morpho-anatomical characteristics of the cork of Dracaena draco L. tree regarding the production of dragon’s blood

    OpenAIRE

    Joanna Jura-Morawiec; Mirela Tulik

    2014-01-01

    The monocotyledonous plant Dracaena draco L. belongs to so called dragon blood trees producing deep red resin (dragon’s blood) that has been used as a famous traditional medicine since ancient times by many cultures. Although resin’s chemistry and its diverse medical application have received much attention, our knowledge of the anatomical basis of the dragon’s blood secretion is scarce when compared with resin/sap secretion of gymnosperms and other angiosperms. The focus of our studies is to...

  9. 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

  10. 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.

  11. 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.

  12. A set of 100 chloroplast DNA primer pairs to study population genetics and phylogeny in monocotylenons

    DEFF Research Database (Denmark)

    Scarcelli, Nora; Bernaud, Adeline; Eiserhardt, Wolf L.;

    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 chloroplast regions: 72 are located in the LSC, 13 in the Small Single Copy (SSC) and 15 in the Inverted...

  13. 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

  14. Bacterial degradation of phenoxy herbicide mixtures 2,4-D and MCPP

    Energy Technology Data Exchange (ETDEWEB)

    Kyeheon Oh; Tuovinen, O.H. (Ohio State Univ., Columbus (United States))

    1991-08-01

    The phenoxy herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-(2-methyl-4-chlorophenoxy)propionic acid (MCPP) have auxin-like growth regulating properties and are extensively used for the control of broad-leaf angiosperm weeds. The microbiological degradation of 2,4-D by pure and mixed cultures has been examined in a number of studies. The authors have previously evaluated the concurrent microbiological degradation of 2,4-D and MCPP in stirred tank reactors. For the present paper, they examined the utilization of the two substrates by three mixed cultures that had a previous history of growth with the respective single phenoxy herbicide.

  15. EMF1, a novel protein involved in the control of shoot architecture and flowering in Arabidopsis

    DEFF Research Database (Denmark)

    Aubert, D.; Chen, L.; Moon, Y.-H.;

    2001-01-01

    shares common motifs that include nuclear localization signals, P-loop, and LXXLL elements. Alteration of EMF1 expression in transgenic plants caused progressive changes in flowering time, shoot determinacy, and inflorescence architecture. EMF1 and its related sequence may belong to a new class......Shoot architecture and flowering time in angiosperms depend on the balanced expression of a large number of flowering time and flower meristem identity genes. Loss-of-function mutations in the Arabidopsis EMBRYONIC FLOWER (EMF) genes cause Arabidopsis to eliminate rosette shoot growth and transform...

  16. Genome sequence and analysis of the tuber crop potato

    DEFF Research Database (Denmark)

    Xu, X.; Pan, S.; Cheng, S.;

    2011-01-01

    and assemble 86% of the 844-megabase genome. We predict 39,031 protein-coding genes and present evidence for at least two genome duplication events indicative of a palaeopolyploid origin. As the first genome sequence of an asterid, the potato genome reveals 2,642 genes specific to this large angiosperm clade....... We also sequenced a heterozygous diploid clone and show that gene presence/absence variants and other potentially deleterious mutations occur frequently and are a likely cause of inbreeding depression. Gene family expansion, tissue-specific expression and recruitment of genes to new pathways...

  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. 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

  19. 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

  20. 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...

  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. Changes of taxonomical composition of Late Jurassic Early Cretaceous palynofloras of Bureya Basin,Russia

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The changes of taxonomical composition of the Late Jurassic-Early Cretaceous palynofloras are revealed,in the upper stream of Bureya River in Bureya Basin.The palynofloras are dominated as follows:the Berriasian one by ferns (Cyatheaceae,Dicksoniaceae,Osmundaceae), Classopollis and bisaccate pollen;the Valanginian-Hauterivian one by ferns (Cyatheaceae,Dicksoniaceae), Ginkgocycadophytus and bisaccate pollen;the Barremian one by ferns(Cyatheaceae,Dieksoniaceae);the Aptian one by ferns(Cyatheaceae,Dieksoniaceae,Gleicheniaceae)and Ginkgocycadophytus;and the Albian one by ferns(Schizaeaceae)and bisaccate pollen.In the Albian the floral diversity raises with the angiosperms appearing.

  3. 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.

  4. First genome size estimations for some eudicot families and genera

    Directory of Open Access Journals (Sweden)

    Garcia, S.

    2010-12-01

    Full Text Available Genome size diversity in angiosperms varies roughly 2400-fold, although approximately 45% of angiosperm families lack a single genome size estimation, and therefore, this range could be enlarged. To contribute completing family and genera representation, DNA C-Values are here provided for 19 species from 16 eudicot families, including first values for 6 families, 14 genera and 17 species. The sample of species studied is very diverse, including herbs, weeds, vines, shrubs and trees. Data are discussed regarding previous genome size estimates of closely related species or genera, if any, their chromosome number, growth form or invasive behaviour. The present research contributes approximately 1.5% new values for previously unreported angiosperm families, being the current coverage around 55% of angiosperm families, according to the Plant DNA C-Values Database.

    La diversidad del tamaño del genoma en angiospermas es muy amplia, siendo el valor más elevado aproximadamente unas 2400 veces superior al más pequeño. Sin embargo, cerca del 45% de las familias no presentan ni una sola estimación, por lo que el rango real podría ser ampliado. Para contribuir a completar la representación de familias y géneros de angiospermas, este estudio contribuye con valores C para 19 especies de 16 familias de eudicoticotiledóneas, incluyendo los primeros valores para 6 familias, 14 géneros y 17 especies. La muestra estudiada es muy diversa, e incluye hierbas, malezas, enredaderas, arbustos y árboles. Se discuten los resultados en función de estimaciones previas del tamaño del genoma de especies o géneros estrechamente relacionados, del número de cromosomas, la forma de crecimiento o el comportamiento invasor de las especies analizadas. El presente estudio contribuye aproximadamente en un 1,5% de nuevos valores para familias de angiospermas no estudiadas previamente, de las que actualmente existe información para el 55%, según la base de datos

  5. 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...

  6. 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 ...

  7. 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

  8. Cavitation and Its Discontents: Opportunities for Resolving Current Controversies1[C

    Science.gov (United States)

    Rockwell, Fulton E.; Wheeler, James K.; Holbrook, N. Michele

    2014-01-01

    Cavitation has long been recognized as a key constraint on the structure and functional integrity of the xylem. Yet, recent results call into question how well we understand cavitation in plants. Here, we consider embolism formation in angiosperms at two scales. The first focuses on how air-seeding occurs at the level of pit membranes, raising the question of whether capillary failure is an appropriate physical model. The second addresses methodological uncertainties that affect our ability to infer the formation of embolism and its reversal in plant stems. Overall, our goal is to open up fresh perspectives on the structure-function relationships of xylem. PMID:24501002

  9. A conserved role for the NAM/miR164 developmental module reveals a common mechanism underlying carpel margin fusion in monocarpous and syncarpous eurosids.

    Directory of Open Access Journals (Sweden)

    Aurelie Chantal Marie Vialette-Guiraud

    2016-01-01

    Full Text Available The majority of angiosperms are syncarpous- their gynoecium is composed of two or more fused carpels. In Arabidopsis thaliana, this fusion is regulated through the balance of expression between CUP SHAPED COTYLEDON (CUC genes, which are orthologues of the Petunia hybrida transcription factor NO APICAL MERISTEM (NAM, and their post-transcriptional regulator miR164. Accordingly, the expression of a miR164-insensitive form of Ar. thaliana CUC2 causes a radical breakdown of carpel fusion. Here, we investigate the role of the NAM/miR164 genetic module in carpel closure in monocarpous plants. We show that the disruption of this module in monocarpous flowers of Ar. thaliana aux1-22 mutants causes a failure of carpel closure, similar to the failure of carpel fusion observed in the wild-type genetic background. This observation suggested that closely related mechanisms may bring about carpel closure and carpel fusion, at least in Ar. thaliana. We therefore tested whether these mechanisms were conserved in a eurosid species that is monocarpous in its wild-type form. We observed that expression of MtNAM, the NAM ortholog in the monocarpous eurosid Medicago truncatula, decreases during carpel margin fusion, suggesting a role for the NAM/miR164 module in this process. We transformed M. truncatula with a miR164-resistant form of MtNAM and observed, among other phenotypes, incomplete carpel closure in the resulting transformants. These data confirm the underlying mechanistic similarity between carpel closure and carpel fusion which we observed in Ar. thaliana. Our observations suggest that the role of the NAM/miR164 module in the fusion of carpel margins has been conserved at least since the most recent common ancestor of the eurosid clade, and open the possibility that a similar mechanism may have been responsible for carpel closure at much earlier stages of angiosperm evolution. We combine our results with studies of early-diverging angiosperms to speculate

  10. Metabolism and resources of spherical colonies of Nostoc zetterstedtii

    DEFF Research Database (Denmark)

    Jensen, Kaj Sand; Raun, Ane-Marie Løvendahl; Borum, Jens

    2009-01-01

    by reduced light availability and only extended to lake depths receiving about 12% of surface irradiance, whereas mosses, characeans, and angiosperms with thin photosynthetic tissues grew deeper (3.1-7.5% of surface irradiance). Nostoc ameliorated the restrictions of low lake DIC and long diffusion paths...... by active transport that could extract most external DIC, accumulate DIC in the colony 150-fold above external concentrations, and retain respiratory CO2. The energy cost of solute transport and gel formation in Nostoc colonies and extensive self shading restrict their potential growth, whereas colony...

  11. Community phylogenetics at the biogeographical scale: cold tolerance, niche conservatism and the structure of North American forests.

    Science.gov (United States)

    Hawkins, Bradford A; Rueda, Marta; Rangel, Thiago F; Field, Richard; Diniz-Filho, José Alexandre F; Linder, Peter

    2014-01-01

    AimThe fossil record has led to a historical explanation for forest diversity gradients within the cool parts of the Northern Hemisphere, founded on a limited ability of woody angiosperm clades to adapt to mid-Tertiary cooling. We tested four predictions of how this should be manifested in the phylogenetic structure of 91,340 communities: (1) forests to the north should comprise species from younger clades (families) than forests to the south; (2) average cold tolerance at a local site should be associated with the mean family age (MFA) of species; (3) minimum temperature should account for MFA better than alternative environmental variables; and (4) traits associated with survival in cold climates should evolve under a niche conservatism constraint. LocationThe contiguous United States. MethodsWe extracted angiosperms from the US Forest Service's Forest Inventory and Analysis database. MFA was calculated by assigning age of the family to which each species belongs and averaging across the species in each community. We developed a phylogeny to identify phylogenetic signal in five traits: realized cold tolerance, seed size, seed dispersal mode, leaf phenology and height. Phylogenetic signal representation curves and phylogenetic generalized least squares were used to compare patterns of trait evolution against Brownian motion. Eleven predictors structured at broad or local scales were generated to explore relationships between environment and MFA using random forest and general linear models. ResultsConsistent with predictions, (1) southern communities comprise angiosperm species from older families than northern communities, (2) cold tolerance is the trait most strongly associated with local MFA, (3) minimum temperature in the coldest month is the environmental variable that best describes MFA, broad-scale variables being much stronger correlates than local-scale variables, and (4) the phylogenetic structures of cold tolerance and at least one other trait

  12. 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.

  13. 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.

  14. 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

  15. Mitochondrial genome sequencing helps show the evolutionary mechanism of mitochondrial genome formation in Brassica

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    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.

  16. A first record of Cretaceous aphids (Hemiptera, Sternorrhyncha, Aphidomorpha) in Australia, from the Lower Cretaceous Koonwarra Fossil Bed, Victoria.

    Science.gov (United States)

    Martin, Sarah K; Skidmore, Luke I; Stilwell, Jeffrey D

    2016-01-01

    This paper describes the first species of aphid from the Lower Cretaceous Koonwarra Fossil Bed of the Gippsland Basin, southeastern Victoria, Australia. This aphid, herein named Koonwarraphis rotundafrons gen. & sp. nov., is assigned to the cosmopolitan Cretaceous superfamily Tajmyraphidoidea, which has been previously described from the Lebanese, Taimyrian, Canadian, Myanmar (Burmese), and Spanish ambers. Koonwarraphis rotundafrons is the first aphid recorded from the eastern Gondwanan landmass during the Cretaceous, and represents the only tajmyraphidoid preserved as a compression fossil, rather than as an amber inclusion. Due to the nature of the fossil's preservation, Koonwarraphis cannot be firmly placed in any of the described tajmyraphidoid families; however, all observable morphological features suggest that the genus is broadly typical of the superfamily and Cretaceous aphids in general. Koonwarraphis' shortened rostrum, a feature also seen in other tajmyraphidoids, suggests an association with the more herbaceous aspects of the Early Cretaceous Victorian flora. Considering the modern aphid preference for angiosperm plants, it is possible that this aphid was living upon the herbaceous early angiosperms recorded previously from the Koonwarra macrofloral assemblage. PMID:27395744

  17. Evolutionary reversion of editing sites of ndh genes suggests their origin in the Permian-Triassic, before the increase of atmospheric CO2

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    Mercedes eMartin

    2015-07-01

    Full Text Available The plastid ndh genes have hovered frequently on the edge of dispensability. They are absent in the plastid DNA of many algae and certain higher plants and present editing sites requiring C-to-U corrections of primary transcripts. The evolutionary origin of editing sites and their loss due to C-to-T reversions at the DNA level are unknown and must be related to the dispensability of the ndh genes in specific environments. In order to better understand the evolution of ndh gene editing sites, we have created expandable data banks with the 12 editing sites of the ndhB gene (600 GenBank sequences and both editing sites of the ndhF gene (1,600 GenBank sequences. Since their origin via T-to-C mutations that probably occurred between 300 and 200 Myr BP (Permian-Triassic, ndh editing sites have undergone independent and random C-to-T reversions in the different angiosperm lineages. Some of these reversions appear early in angiosperm diversification. Old C-to-T reversions can be traced back to radiation steps that gave origin to main classes, orders and some families.

  18. 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.

  19. Mutations in AtPS1 (Arabidopsis thaliana parallel spindle 1 lead to the production of diploid pollen grains.

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    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.

  20. Diversification of the phaseoloid legumes: Effects of climate change, range expansion and habit shift

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    Honglei eLi

    2013-10-01

    Full Text Available Understanding which factors have driven the evolutionary success of a group is a fundamental question in biology. Angiosperms are the most successful group in plants and have radiated and adapted to various habitats. Among angiosperms, legumes are a good example for such successful radiation and adaptation. We here investigated how the interplay of past climate changes, geographical expansion and habit shifts have promoted diversification of the phaseoloid legumes, one of the largest clades in the Leguminosae. Using a comprehensive genus-level phylogeny from three plastid markers, we estimate divergence times, infer habit shifts, test the phylogenetic and temporal diversification heterogeneity, and reconstruct ancestral biogeographical ranges. We found that the phaseoloid lineages underwent twice dramatic accumulation. During the Late Oligocene, at least six woody clades rapidly diverged, perhaps in response to the Late Oligocene warming and aridity, and a result of rapidly exploiting new ecological opportunities in Asia, Africa and Australia. The most speciose lineage is herbaceous and began to rapidly diversify since the Early Miocene, which was likely ascribed to arid climates, along with the expansion of seasonally dry tropical forests in Africa, Asia and America. The phaseoloid group provides an excellent case supporting the idea that the interplay of ecological opportunities and key innovations drive the evolutionary success.

  1. 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

  2. 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.

  3. A gDNA microarray for genotyping salvia species.

    Science.gov (United States)

    Olarte, Alexandra; Mantri, Nitin; Nugent, Gregory; Wohlmuth, Hans; Li, Chun Guang; Xue, Charlie; Pang, Edwin

    2013-07-01

    Salvia is an important genus from the Lamiaceae with approximately 1,000 species. This genus is distributed globally and cultivated for ornamental, culinary, and medicinal uses. We report the construction of the first fingerprinting array for Salvia species enriched with polymorphic and divergent DNA sequences and demonstrate the potential of this array for fingerprinting several economically important members of this genus. In order to generate the Salvia subtracted diversity array (SDA) a suppression subtractive hybridization (SSH) was performed between a pool of Salvia species and a pool of angiosperms and non-angiosperms to selectively isolate Salvia-specific sequences. A total of 285-subtracted genomic DNA (gDNA) fragments were amplified and arrayed. DNA fingerprints were obtained for fifteen Salvia genotypes including three that were not part of the original subtraction pool. Hierarchical cluster analysis indicated that the Salvia-specific SDA was capable of differentiating S. officinalis and S. miltiorrhiza from their closely related species and was also able to reveal genetic relationships consistent with geographical origins. In addition, this approach was capable of isolating highly polymorphic sequences from chloroplast and nuclear DNA without preliminary sequence information. Therefore, SDA is a powerful technique for fingerprinting non-model plants and for identifying new polymorphic loci that may be developed as potential molecular markers.

  4. 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

  5. [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

  6. 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.

  7. 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.

  8. 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

  9. Balanced gene losses, duplications and intensive rearrangements led to an unusual regularly sized genome in Arbutus unedo chloroplasts.

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    Fernando Martínez-Alberola

    Full Text Available Completely sequenced plastomes provide a valuable source of information about the duplication, loss, and transfer events of chloroplast genes and phylogenetic data for resolving relationships among major groups of plants. Moreover, they can also be useful for exploiting chloroplast genetic engineering technology. Ericales account for approximately six per cent of eudicot diversity with 11,545 species from which only three complete plastome sequences are currently available. With the aim of increasing the number of ericalean complete plastome sequences, and to open new perspectives in understanding Mediterranean plant adaptations, a genomic study on the basis of the complete chloroplast genome sequencing of Arbutus unedo and an updated phylogenomic analysis of Asteridae was implemented. The chloroplast genome of A. unedo shows extensive rearrangements but a medium size (150,897 nt in comparison to most of angiosperms. A number of remarkable distinct features characterize the plastome of A. unedo: five-fold dismissing of the SSC region in relation to most angiosperms; complete loss or pseudogenization of a number of essential genes; duplication of the ndhH-D operon and its location within the two IRs; presence of large tandem repeats located near highly re-arranged regions and pseudogenes. All these features outline the primary evolutionary split between Ericaceae and other ericalean families. The newly sequenced plastome of A. unedo with the available asterid sequences allowed the resolution of some uncertainties in previous phylogenies of Asteridae.

  10. 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

  11. Dinosaur egg deposits in the Cretaceous Gyeongsang Supergroup, Korea: Diversity and paleobiological implications

    Science.gov (United States)

    Paik, In Sung; Kim, Hyun Joo; Huh, Min

    2012-08-01

    The taphonomy and depositional environments of dinosaur-egg-bearing deposits in the Cretaceous Gyeongsang Basin, Korea, are described and their paleobiological implications are discussed in the context of global geographic occurrences, geological ages, paleoenvironments, and lithology. The general depositional environment of dinosaur egg deposits in the Gyeongsang Supergroup is interpreted as dry floodplains with a semi-arid climate and intermittent volcanic activity. The diverse floodplain paleoenvironments include fluvial plains with meandering rivers to alluvial plains with episodic sheet-flooding. Both global and Korean dinosaur-egg-bearing deposits are generally restricted to the Late Cretaceous, a phenomenon for which two possible explanations are proposed. The first possible explanation for the temporal limitation of dinosaur egg preservation involves the appearance of angiosperms in the Late Jurassic, the Late Cretaceous ecological dispersion of angiosperm trees into swamps and floodplains, and the attendant change in herbivorous dinosaurs' diets. The second possible reason is related to nesting behavior in the Cretaceous. By contrast to the temporally limited occurrence of dinosaur eggs, paleoenvironments of nesting areas are diverse, ranging from inland areas to coastal areas. These hypotheses may provide new directions for the study and understanding of dinosaur egg distribution in the context of geologic time.

  12. Apoplastic interactions between plants and plant root intruders

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    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.

  13. Characterisation of detergent-insoluble membranes in pollen tubes of Nicotiana tabacum (L.

    Directory of Open Access Journals (Sweden)

    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.

  14. 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.

  15. Evolutionary bursts in Euphorbia (Euphorbiaceae) are linked with photosynthetic pathway.

    Science.gov (United States)

    Horn, James W; Xi, Zhenxiang; Riina, Ricarda; Peirson, Jess A; Yang, Ya; Dorsey, Brian L; Berry, Paul E; Davis, Charles C; Wurdack, Kenneth J

    2014-12-01

    The mid-Cenozoic decline of atmospheric CO2 levels that promoted global climate change was critical to shaping contemporary arid ecosystems. Within angiosperms, two CO2 -concentrating mechanisms (CCMs)-crassulacean acid metabolism (CAM) and C4 -evolved from the C3 photosynthetic pathway, enabling more efficient whole-plant function in such environments. Many angiosperm clades with CCMs are thought to have diversified rapidly due to Miocene aridification, but links between this climate change, CCM evolution, and increased net diversification rates (r) remain to be further understood. Euphorbia (∼2000 species) includes a diversity of CAM-using stem succulents, plus a single species-rich C4 subclade. We used ancestral state reconstructions with a dated molecular phylogeny to reveal that CCMs independently evolved 17-22 times in Euphorbia, principally from the Miocene onwards. Analyses assessing among-lineage variation in r identified eight Euphorbia subclades with significantly increased r, six of which have a close temporal relationship with a lineage-corresponding CCM origin. Our trait-dependent diversification analysis indicated that r of Euphorbia CCM lineages is approximately threefold greater than C3 lineages. Overall, these results suggest that CCM evolution in Euphorbia was likely an adaptive strategy that enabled the occupation of increased arid niche space accompanying Miocene expansion of arid ecosystems. These opportunities evidently facilitated recent, replicated bursts of diversification in Euphorbia.

  16. The evolutionary diversification of seed size: using the past to understand the present.

    Science.gov (United States)

    Sims, Hallie J

    2012-05-01

    The Devonian origin of seed plants and subsequent morphological diversification of seeds during the late Paleozoic represents an adaptive radiation into unoccupied ecological niche space. A plant's seed size is correlated with its life-history strategy, growth form, and seed dispersal syndrome. The fossil record indicates that the oldest seed plants had relatively small seeds, but the Mississippian seed size envelope increased significantly with the diversification of larger seeded lineages. Fossil seeds equivalent to the largest extant gymnosperm seeds appeared by the Pennsylvanian, concurrent with morphological diversification of growth forms and dispersal syndromes as well as the clade's radiation into new environments. Wang's Analysis of Skewness indicates that the evolutionary trend of increasing seed size resulted from primarily passive processes in Pennsylvanian seed plants. The distributions of modern angiosperms indicate a more diverse system of active and some passive processes, unbounded by Paleozoic limits; multiple angiosperm lineages independently evolved though the upper and lower bounds. Quantitative measures of preservation suggest that, although our knowledge of Paleozoic seeds is far from complete, the evolutionary trend in seed size is unlikely to be an artifact of taphonomy.

  17. Ferns: the missing link in shoot evolution and development

    Directory of Open Access Journals (Sweden)

    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.

  18. 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

  19. 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

  20. Screening the wetland plant species Alisma plantago-aquatica, Carex rostrata and Phalaris arundinacea for innate tolerance to zinc and comparison with Eriophorum angustifolium and Festuca rubra Merlin

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, David J. [Wetland Ecology Research Group, Department of Botany, University College Dublin, Belfield, Dublin 4 (Ireland)]. E-mail: davematt00@hotmail.com; Moran, Bridget M. [Wetland Ecology Research Group, Department of Botany, University College Dublin, Belfield, Dublin 4 (Ireland); Otte, Marinus L. [Wetland Ecology Research Group, Department of Botany, University College Dublin, Belfield, Dublin 4 (Ireland)

    2005-03-01

    Several wetland plant species appear to have constitutive metal tolerance. In previous studies, populations from contaminated and non-contaminated sites of the wetland plants Typha latifolia, Phragmites australis, Glyceria fluitans and Eriophorum angustifolium were found to be tolerant to high concentrations of metals. This study screened three other species of wetland plants: Alisma plantago-aquatica, Carex rostrata and Phalaris arundinacea for innate tolerance to zinc. The degree of tolerance was compared to known zinc-tolerant E. angustifolium and Festuca rubra Merlin. It was found that A. plantago-aquatica and P. arundinacea did not posses innate tolerance to zinc, but that C. rostrata was able to tolerate elevated levels of zinc, at levels comparable to those tolerated by E. angustifolium and F. rubra Merlin. The findings support the theory that some wetland angiosperm species tend to be tolerant to exposure to high levels of metals, regardless of their origin. - Some wetland angiosperms are tolerant to high concentrations of metals, regardless of conditions in the plants' natural habitat.

  1. 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

  2. Plant Raf-like kinase integrates abscisic acid and hyperosmotic stress signaling upstream of SNF1-related protein kinase2.

    Science.gov (United States)

    Saruhashi, Masashi; Kumar Ghosh, Totan; Arai, Kenta; Ishizaki, Yumiko; Hagiwara, Kazuya; Komatsu, Kenji; Shiwa, Yuh; Izumikawa, Keiichi; Yoshikawa, Harunori; Umezawa, Taishi; Sakata, Yoichi; Takezawa, Daisuke

    2015-11-17

    Plant response to drought and hyperosmosis is mediated by the phytohormone abscisic acid (ABA), a sesquiterpene compound widely distributed in various embryophyte groups. Exogenous ABA as well as hyperosmosis activates the sucrose nonfermenting 1 (SNF1)-related protein kinase2 (SnRK2), which plays a central role in cellular responses against drought and dehydration, although the details of the activation mechanism are not understood. Analysis of a mutant of the moss Physcomitrella patens with reduced ABA sensitivity and reduced hyperosmosis tolerance revealed that a protein kinase designated "ARK" (for "ABA and abiotic stress-responsive Raf-like kinase") plays an essential role in the activation of SnRK2. ARK encoded by a single gene in P. patens belongs to the family of group B3 Raf-like MAP kinase kinase kinases (B3-MAPKKKs) mediating ethylene, disease resistance, and salt and sugar responses in angiosperms. Our findings indicate that ARK, as a novel regulatory component integrating ABA and hyperosmosis signals, represents the ancestral B3-MAPKKKs, which multiplied, diversified, and came to have specific functions in angiosperms. PMID:26540727

  3. Heterostyly accelerates diversification via reduced extinction in primroses.

    Science.gov (United States)

    de Vos, Jurriaan M; Hughes, Colin E; Schneeweiss, Gerald M; Moore, Brian R; Conti, Elena

    2014-06-01

    The exceptional species diversity of flowering plants, exceeding that of their sister group more than 250-fold, is especially evident in floral innovations, interactions with pollinators and sexual systems. Multiple theories, emphasizing flower-pollinator interactions, genetic effects of mating systems or high evolvability, predict that floral evolution profoundly affects angiosperm diversification. However, consequences for speciation and extinction dynamics remain poorly understood. Here, we investigate trajectories of species diversification focusing on heterostyly, a remarkable floral syndrome where outcrossing is enforced via cross-compatible floral morphs differing in placement of their respective sexual organs. Heterostyly evolved at least 20 times independently in angiosperms. Using Darwin's model for heterostyly, the primrose family, we show that heterostyly accelerates species diversification via decreasing extinction rates rather than increasing speciation rates, probably owing to avoidance of the negative genetic effects of selfing. However, impact of heterostyly appears to differ over short and long evolutionary time-scales: the accelerating effect of heterostyly on lineage diversification is manifest only over long evolutionary time-scales, whereas recent losses of heterostyly may prompt ephemeral bursts of speciation. Our results suggest that temporal or clade-specific conditions may ultimately determine the net effects of specific traits on patterns of species diversification.

  4. 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.

  5. Comparative pathobiology of Heterobasidion annosum during challenge on Pinus sylvestris and Arabidopsis roots: an analysis of defensin gene expression in two pathosystems.

    Science.gov (United States)

    Jaber, Emad; Xiao, Chaowen; Asiegbu, Fred O

    2014-03-01

    Heterobasidion annosum is widely known as a major root and butt rot pathogen of conifer trees, but little information is available on its interaction with the roots of herbaceous angiosperm plants. We investigated the infection biology of H. annosum during challenge with the angiosperm model Arabidopsis and monitored the host response after exposure to different hormone elicitors, chemicals (chitin, glucan and chitosan) and fungal species that represent diverse basidiomycete life strategies [e.g., pathogen (H. annosum), saprotroph (Stereum sanguinolentum) and mutualist (Lactarius rufus)]. The results revealed that the tree pathogen (H. annosum) and the saprotroph (S. sanguinolentum) could infect the Col-8 (Columbia) ecotype of Arabidopsis in laboratory inoculation experiments. Germinated H. annosum spores had appressorium-like penetration structures attached to the surface of the Arabidopsis roots. Subsequent invasive fungal growth led to the disintegration of the vascular region of the root tissues. Progression of root rot symptoms in Arabidopsis was similar to the infection development that was previously documented in Scots pine seedlings. Scots pine PsDef1 and Arabidopsis DEFLs (AT5G44973.1) and PDF1.2 were induced at the initial stage of the infection. However, differences in the expression patterns of the defensin gene homologs from the two plant groups were observed under various conditions, suggesting functional differences in their regulation. The potential use of the H. annosum-Arabidopsis pathosystem as a model for studying forest tree diseases is discussed. PMID:24366684

  6. 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.

  7. Evolution of fruit development genes in flowering plants

    Directory of Open Access Journals (Sweden)

    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.

  8. 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

  9. Plant transposons: contributors to evolution?

    Science.gov (United States)

    Lönnig, W E; Saedler, H

    1997-12-31

    A spectrum of different hypotheses has been presented by various authors, from plant transposable elements as major agents in evolution to the very opposite, transposons as mainly selfish DNA constituting a genetic burden for the organisms. The following review will focus on: (1) a short survey of the two main different assessments of transposable elements (TEs) concerning the origin of species (selfish vs useful DNA); (2) the significance of the hierarchy of gene functions and redundancies for TE activities (selfish in non-redundant parts of the genome, but as a source of variability in the rest); (3) the relevance of the results of TE research in Zea mays and Antirrhinum majus for species formation in the wild (contrast between artificial and natural selection); (4) three areas of research where a synthesis between the two different evaluations of TEs seems possible: regressive evolution, the origin of ecotypes and the origin of cultivated plants; and (5) some possible prospects regarding TE-induced species formation in the angiosperms in general, i.e., the basic difference between systematic and genetic species concepts and the conceivable origin of a large part of angiosperm morphospecies owing to loss of function and further mutations by TE activities. PMID:9461398

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Annonaceae: bio-resource for tomorrow's drug discovery.

    Science.gov (United States)

    Aminimoghadamfarouj, Noushin; Nematollahi, Alireza; Wiart, Christophe

    2011-05-01

    One of the rich sources of lead compounds is the Angiosperms. Many of these lead compounds are useful medicines naturally, whereas others have been used as the basis for synthetic agents. These are potent and effective compounds, which have been obtained from plants, including anti-cancer (cytotoxic) agents, anti-malaria (anti-protozoal) agents, and anti-bacterial agents. Today, the number of plant families that have been extensively studied is relatively very few and the vast majorities have not been studied at all. The Annonaceae is the largest family in the order Magnoliales. It includes tropical trees, bushes, and climbers, which are often used as traditional remedies in Southeast Asia. Members of the Annonaceae have the particularity to elaborate a broad spectrum of natural products that have displayed anti-bacterial, anti-fungal, and anti-protozoal effects and have been used for the treatment of medical conditions, such as skin diseases, intestinal worms, inflammation of the eyes, HIV, and cancer. These special effects and the vast range of variation in potent compounds make the Annonaceae unique from other similar families in the Magnoliales and the Angiosperms in general. This paper attempts to summarize some important information and discusses a series of hypotheses about the effects of Annonaceae compounds.

  16. 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.

  17. Phylogenetic investigation of the complex evolutionary history of dispersal mode and diversification rates across living and fossil Fagales.

    Science.gov (United States)

    Larson-Johnson, Kathryn

    2016-01-01

    As a primary determinant of spatial structure in angiosperm populations, fruit dispersal may impact large-scale ecological and evolutionary processes. Essential to understanding these mechanisms is an accurate reconstruction of dispersal mode over the entire history of an angiosperm lineage. A total-evidence phylogeny is presented for most fossil fruit and all extant genera in Fagales over its c. 95 million yr history. This phylogeny - the largest of its kind to include plant fossils - was used to reconstruct an evolutionary history directly informed by fossil morphologies and to assess relationships among dispersal mode, biogeographic range size, and diversification rate. Reconstructions indicate four transitions to wind dispersal and seven to biotic dispersal, with the phylogenetic integration of fossils crucial to understanding these patterns. Complexity further increased when more specialized behaviors were considered, with fluttering, gliding, autorotating, and scatter-hoarding evolving multiple times across the order. Preliminary biogeographic analyses suggest larger range sizes in biotically dispersed lineages, especially when pollination mode was held constant. Biotically dispersed lineages had significantly higher diversification rates than abiotically dispersed lineages, although transitions in dispersal mode alone cannot explain all detected diversification rate shifts across Fagales.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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)

  3. 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.

  4. 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.

  5. Apoplastic interactions between plants and plant root intruders.

    Science.gov (United States)

    Mitsumasu, Kanako; Seto, Yoshiya; Yoshida, Satoko

    2015-01-01

    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, 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.

  6. A census of nuclear cyanobacterial recruits in the plant kingdom.

    Directory of Open Access Journals (Sweden)

    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.

  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. Reconstruction of the charophyte community of Lake Shinji by oospore collection

    Directory of Open Access Journals (Sweden)

    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.

  10. Dr. Roberto Miguel Klein Herbarium (FURB, Blumenau, Southern Brazil

    Directory of Open Access Journals (Sweden)

    Andre de Gasper

    2014-10-01

    Full Text Available The premise of this study is to present the collection of the FURB herbarium, its collection area and type specimens, as well as its projects and contributions to the flora of the Subtropical Atlantic Forest. The FURB herbarium currently has nearly 41,000 records of vascular plants and has the largest collection of lycophytes and ferns in Southern Brazil, with more than 8,000 records. More than 4,500 scanned images of 4,436 species are available online, and it is expected that the whole collection will be scanned in less than one year. There are 198 families of angiosperms, 33 of ferns, three of lycophytes and six of gymnosperms. All collections of the Floristic and Forest Inventory of Santa Catarina project are recorded in FURB, which represents almost 35,000 herbarium specimens. The families with the largest number of species are: Cyperaceae (109 species, Rubiaceae (129, Solanaceae (131, Poaceae (155, Melastomataceae (157, Myrtaceae (257, Orchidaceae (288, Fabaceae (323, and Asteraceae (426, between angiosperms. Among the ferns and lycophytes are: Hymenophyllaceae (30, Thelypteridaceae (31, Aspleniaceae (32, Dryopteridaceae (43, Pteridaceae (54 and Polypodiaceae (60. There are five type specimens among them: one holotype, one isotype and three paratypes. To date, the FURB herbarium has donated 19,521 herbarium duplicates for identification or expansion of other herbaria.

  11. Substantial role of macroalgae in marine carbon sequestration

    Science.gov (United States)

    Krause-Jensen, Dorte; Duarte, Carlos M.

    2016-10-01

    Vegetated coastal habitats have been identified as important carbon sinks. In contrast to angiosperm-based habitats such as seagrass meadows, salt marshes and mangroves, marine macroalgae have largely been excluded from discussions of marine carbon sinks. Macroalgae are the dominant primary producers in the coastal zone, but they typically do not grow in habitats that are considered to accumulate large stocks of organic carbon. However, the presence of macroalgal carbon in the deep sea and sediments, where it is effectively sequestered from the atmosphere, has been reported. A synthesis of these data suggests that macroalgae could represent an important source of the carbon sequestered in marine sediments and the deep ocean. We propose two main modes for the transport of macroalgae to the deep ocean and sediments: macroalgal material drifting through submarine canyons, and the sinking of negatively buoyant macroalgal detritus. A rough estimate suggests that macroalgae could sequester about 173 TgC yr-1 (with a range of 61-268 TgC yr-1) globally. About 90% of this sequestration occurs through export to the deep sea, and the rest through burial in coastal sediments. This estimate exceeds that for carbon sequestered in angiosperm-based coastal habitats.

  12. 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.

  13. Of plants and other pets: practical aspects of freeze-substitution and resin embedding.

    Science.gov (United States)

    Hess, M W

    2003-10-01

    Representative tissues from higher plants (e.g. developing pollen, somatic anther tissues from the monocotyledonous angiosperm Ledebouria) and mammalian cell cultures were successfully cryoimmobilized by means of high-pressure freezing. Various substitution and embedding protocols were then evaluated considering the preservation of ultrastructural details, membrane staining, immunolabelling properties, as well as reproducibility and ease of use. Two types of recipe proved to be highly suitable for most applications, regardless of type, developmental stage or physiological conditions of the cells: (i) the best choice for morphology is still osmium in acetone (optionally supplemented with uranyl acetate) followed by embedding in Epon and/or Araldite; (ii) feasible approaches for immunocytochemistry are freeze-substitution with ethanol containing uranyl acetate and formaldehyde, or with pure acetone (in the case of fixation-sensitive antigens), followed by embedding with LR-white acrylic resin; though being far from optimal, these combinations represent, in my opinion, an acceptable compromise between labelling intensity, section stability, structural preservation and health hazards. Notably, the patterns observed in Ledebouria were consistent with data obtained from a broad range of other specimens from all kingdoms (e.g. leaves and callus cultures from angiosperms, gymnosperm roots with their ectomycorrhizal fungi, mammalian cell cultures and eubacteria). Finally, a warning is given as to the extractive potentials of embedding resins (Spurr's mixture, LR-white, but also Epon) being sometimes the cause of unacceptable artefacts, both in plant and in mammalian cells prepared by cryoimmobilization and freeze-substitution.

  14. 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

  15. 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

  16. 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

  17. 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

  18. The leaves of green plants as well as a cyanobacterium, a red alga, and fungi contain insulin-like antigens

    Directory of Open Access Journals (Sweden)

    L.B. Silva

    2002-03-01

    Full Text Available We report the detection of insulin-like antigens in a large range of species utilizing a modified ELISA plate assay and Western blotting. We tested the leaves or aerial parts of species of Rhodophyta (red alga, Bryophyta (mosses, Psilophyta (whisk ferns, Lycopodophyta (club mosses, Sphenopsida (horsetails, gymnosperms, and angiosperms, including monocots and dicots. We also studied species of fungi and a cyanobacterium, Spirulina maxima. The wide distribution of insulin-like antigens, which in some cases present the same electrophoretic mobility as bovine insulin, together with results recently published by us on the amino acid sequence of an insulin isolated from the seed coat of jack bean (Canavalia ensiformis and from the developing fruits of cowpea (Vigna unguiculata, suggests that pathways depending on this hormone have been conserved through evolution.

  19. 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.

  20. 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

  1. 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

  2. The molecular mechanism and physiological role of cytoplasmic streaming.

    Science.gov (United States)

    Tominaga, Motoki; Ito, Kohji

    2015-10-01

    Cytoplasmic streaming occurs widely in plants ranging from algae to angiosperms. However, the molecular mechanism and physiological role of cytoplasmic streaming have long remained unelucidated. Recent molecular genetic approaches have identified specific myosin members (XI-2 and XI-K as major and XI-1, XI-B, and XI-I as minor motive forces) for the generation of cytoplasmic streaming among 13 myosin XIs in Arabidopsis thaliana. Simultaneous knockout of these myosin XI members led to a reduced velocity of cytoplasmic streaming and marked defects of plant development. Furthermore, the artificial modifications of myosin XI-2 velocity changed plant and cell sizes along with the velocity of cytoplasmic streaming. Therefore, we assume that cytoplasmic streaming is one of the key regulators in determining plant size.

  3. Cytoplasmic streaming velocity as a plant size determinant.

    Science.gov (United States)

    Tominaga, Motoki; Kimura, Atsushi; Yokota, Etsuo; Haraguchi, Takeshi; Shimmen, Teruo; Yamamoto, Keiichi; Nakano, Akihiko; Ito, Kohji

    2013-11-11

    Cytoplasmic streaming is active transport widely occurring in plant cells ranging from algae to angiosperms. Although it has been revealed that cytoplasmic streaming is generated by organelle-associated myosin XI moving along actin bundles, the fundamental function in plants remains unclear. We generated high- and low-speed chimeric myosin XI by replacing the motor domains of Arabidopsis thaliana myosin XI-2 with those of Chara corallina myosin XI and Homo sapiens myosin Vb, respectively. Surprisingly, the plant sizes of the transgenic Arabidopsis expressing high- and low-speed chimeric myosin XI-2 were larger and smaller, respectively, than that of the wild-type plant. This size change correlated with acceleration and deceleration, respectively, of cytoplasmic streaming. Our results strongly suggest that cytoplasmic streaming is a key determinant of plant size. Furthermore, because cytoplasmic streaming is a common system for intracellular transport in plants, our system could have applications in artificial size control in plants.

  4. 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.

  5. 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

  6. Before the 'Big Chill': Patterns of plant-insect associations from the Neogene of Iceland

    Science.gov (United States)

    Wappler, Torsten; Grímsson, Friðgeir

    2016-07-01

    Iceland is the only known terrestrial place in the subarctic North Atlantic providing a fairly continuous sedimentary and plant fossil record over the past 15 million years. While the basic palaeobotanical framework of this pattern has been well established during the last decade, less attention has been paid to the abundant insect traces on fossil leaves/leaflets. Here, we assess the diversity and frequency of insect herbivory on 4349 fossil angiosperm leaves/leaflets from six plant-bearing sedimentary formations exposed at 18 localities. By combining analyses of environmental factors, species interactions, ecology, biogeography, and the geological history, our results demonstrate how patterns of herbivory have changed over time in relation to temperature fluctuations that profoundly influenced levels of insect-mediated damage diversity and frequency. In addition, higher structural complexity, particularly the establishment of species-rich herb layer communities seems to have positively influenced the structure of insect communities in early late Miocene palaeoforests of Iceland.

  7. Evolution of leaf form correlates with tropical–temperate transitions in Viburnum (Adoxaceae)

    Science.gov (United States)

    Schmerler, Samuel B.; Clement, Wendy L.; Beaulieu, Jeremy M.; Chatelet, David S.; Sack, Lawren; Donoghue, Michael J.; Edwards, Erika J.

    2012-01-01

    Strong latitudinal patterns in leaf form are well documented in floristic comparisons and palaeobotanical studies. However, there is little agreement about their functional significance; in fact, it is still unknown to what degree these patterns were generated by repeated evolutionary adaptation. We analysed leaf form in the woody angiosperm clade Viburnum (Adoxaceae) and document evolutionarily correlated shifts in leafing habit, leaf margin morphology, leaf shape and climate. Multiple independent shifts between tropical and temperate forest habitats have repeatedly been accompanied by a change between evergreen, elliptical leaves with entire margins and deciduous, more rounded leaves with toothed or lobed margins. These consistent shifts in Viburnum support repeated evolutionary adaptation as a major determinant of the global correlation between leaf form and mean annual temperature. Our results provide a new theoretical grounding for the inference of past climates using fossil leaf assemblages. PMID:22810426

  8. Maximum sustainable xylem sap tensions in Rhododendron and other species.

    Science.gov (United States)

    Crombie, D S; Milburn, J A; Hipkins, M F

    1985-01-01

    The acoustic technique was used in conjunction with the pressure chamber to determine the tensions causing cavitation of xylem sap in leaves of five woody angiosperms (Acer pseudoplatanus L., Alnus glutinosa L. Gaertn., Eucalyptus globulus Labill., Fraxinus excelsior L. and Rhododendron ponticum L.) and three species of herbs (Lycopersicum esculentum Mill., Plantago major L. and Ricinus communis L.). The results showed leaves of most species to suffer considerably from cavitation at sap tensions of 1.6-3 MPa. Two of the herbs, Lycopersicum and Ricinus, cavitated extensively at sap tensions below 1 MPa. Additional evidence is presented that clicks, detected by acoustic amplification, are caused by cavitation of sap in the xylem conduits. A rapid method is suggested for the determination of sap tensions in cavitating leaves and which is suitable for surveys of the critical sap tension in a large number of species.

  9. 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

  10. 江西官山2种苔藓植物叶片氮磷化学计量学特征%The leaf nitrogen:phosphorus stoichiometry of two bryophyte species in Guanshan Mountain, Jiangxi Province

    Institute of Scientific and Technical Information of China (English)

    陈昕; 欧阳明; 黄兰; 徐佳文; 林国江; 杨清培

    2015-01-01

    Nitrogen (N) and Phosphorus (P) stoichiometry is crucial to plant growth, development and adaptive capacity. Bryophytes belong to ancient plant groups, can adapt to the change of the natural environment for a long time. However, The leaf N and P stoichiometry and adaptation mechanism for bryophytes are still unclear. In this study, two typical bryophytes (Marchantia polymorpha, Hypnum plumaeforme) and two kinds of angiosperms (Rubus buergeri, Schima superba) which as a control were selected in Guanshan National Nature Reserve, Jiangxi province, then comparatively analyzed the leaf N and P content, leaf N:P and coefficients of variation and so on. Results showed that: (1) Bryophytes leaf P average content was 2.58 mg/g, significantly higher than that was 1.97 mg/g in two angiosperms, while leaf N:P average was 5.99, obviously lower than 8.35 of angiosperms. (2) The variation range was great of leaf N, P and N:P in bryophytes, whose variation coefficients were 18.94%, 22.05%and 18.52%, respectively were higher than 13.16%, 10.69%, and 13.00% of angiosperms. Above results indicated that bryophytes owned high P content, low N:P and had strong plasticity, we suggest that the ecological adaptation and environmental transformation function of bryophyte should be continue to study in depth.%氮(N)、磷(P)化学计量学特征对植物的生长发育及适应能力至关重要,苔藓植物属古老的植物类群,能够长期适应自然环境的变化,但其氮磷化学计量学特征及适应机制尚不清楚. 本文在江西省官山国家级自然保护区选择2种典型苔藓植物地钱(Marchantia polymorpha) 和大灰藓(Hypnum plumaeforme), 并以2种被子植物寒莓(Rubus buergeri)和木荷(Schima superb)为对照,比较分析了叶片的N、P含量、N:P和变异系数等指标. 结果表明:(1)与2种被子植物相比,苔藓植物P含量较高,N:P较低,其叶片P含量平均值为2.58 mg/g显著高于被子植物的1.97 mg/g,而其

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. Strategies of delayed self-pollination in Kosteletzkya virginica

    Institute of Scientific and Technical Information of China (English)

    RUAN Chengjiang; QIN Pei; HAN Ruiming

    2005-01-01

    @@ Though in the face of selection against self-pollina-tion, mixed pollination systems are maintained in many plants. The transition from outcrossing to self-fertilization is one of the most common evolutionary trends in angio-sperms[1]. Floral morphological characters and behavior influence plant pollination mode and reproductive success, such as herkogamy[2,3], dichogamy[2,3], floral movement, and corolla abscission[4-6]. If a plant population relies solely on animal vectors to move pollen among individu-als and if pollinators are absent or in low numbers at cer-tain times or years, individuals that can self-pollinate if not previously outcrossed will be at a selective advantage[7].

  16. 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.

  17. Pollen storages in nests of bees of the genera Partamona, Scaura and Trigona (Hymenoptera, Apidae

    Directory of Open Access Journals (Sweden)

    André Rodrigo Rech

    2011-09-01

    Full Text Available 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 acetolysis technique. The overlap of the trophic niche and the grouping of species by similarity of niches was calculated. The identification revealed 78 pollen types belonging to 36 families, being 37 types attractive and 16 considered as promoters of a temporary specialization event. With the results, it was possible to indicate a list of important plants for meliponiculture in the Amazon.

  18. The evolutionary history of calreticulin and calnexin genes in green plants.

    Science.gov (United States)

    Del Bem, Luiz Eduardo V

    2011-02-01

    Calreticulin and calnexin are Ca(2+)-binding chaperones localized in the endoplasmic reticulum of eukaryotes acting in glycoprotein folding quality control and Ca(2+) homeostasis. The evolutionary histories of calreticulin and calnexin gene families were inferred by comprehensive phylogenetic analyses using 18 completed genomes and ESTs covering the major green plants groups, from green algae to angiosperms. Calreticulin and calnexin possibly share a common origin, and both proteins are present along all green plants lineages. The calreticulin founder gene within green plants duplicated in early tracheophytes leading to two possible groups of orthologs with specialized functions, followed by lineage-specific gene duplications in spermatophytes. Calnexin founder gene in land plants was inherited from basal green algae during evolution in a very conservative copy number. A comprehensive classification in possible groups of orthologs and a catalog of calreticulin and calnexin genes from green plants are provided.

  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. Homospermidine in transgenic tobacco results in considerably reduced spermidine levels but is not converted to pyrrolizidine alkaloid precursors.

    Science.gov (United States)

    Abdelhady, Mohamed I S; Beuerle, Till; Ober, Dietrich

    2009-09-01

    Homospermidine synthase is the first specific enzyme in the biosynthesis of pyrrolizidine alkaloids. Whereas the substrates putrescine and spermidine are part of the highly dynamic polyamine pool of plants, the product homospermidine is incorporated exclusively into the necine base moiety of pyrrolizidine alkaloids. Recently, the gene encoding homospermidine synthase has been shown to have been recruited several times independently during angiosperm evolution by the duplication of the gene encoding deoxyhypusine synthase. To test whether high levels of homospermidine suffice for conversion, at least in traces, to precursors of pyrrolizidine alkaloids, transgenic tobacco plants were generated expressing homospermidine synthase. Analyses of the polyamine content revealed that, in the transgenic plants, about 80% of spermidine was replaced by homospermidine without any conspicuous modifications of the phenotype. Tracer-feeding experiments and gas chromatographic analyses suggested that these high levels of homospermidine were not sufficient to explain the formation of alkaloid precursors. These results are discussed with respect to current models of pathway evolution. PMID:19543980

  1. 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.

  2. Two sides of the same coin: Xyloglucan endotransglucosylases/hydrolases in host infection by the parasitic plant Cuscuta

    Science.gov (United States)

    Olsen, Stian; Popper, Zoë A.; Krause, Kirsten

    2016-01-01

    ABSTRACT The holoparasitic angiosperm Cuscuta develops haustoria that enable it to feed on other plants. Recent findings corroborate the long-standing theory that cell wall modifications are required in order for the parasite to successfully infect a host, and further suggest that changes to xyloglucan through the activity of xyloglucan endotransglucosylases/hydrolases (XTHs) are essential. On the other hand, XTH expression was also detected in resistant tomato upon an attack by Cuscuta, which suggests that both host and parasite use these enzymes in their “arms race.” Here, we summarize existing data on the cell wall-modifying activities of XTHs during parasitization and present a model suggesting how XTHs might function to make the host's resources accessible to Cuscuta. PMID:26852915

  3. 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

  4. Identification of seagrasses in the gut of a marine herbivorous fish using DNA barcoding and visual inspection techniques.

    Science.gov (United States)

    Chelsky Budarf, A; Burfeind, D D; Loh, W K W; Tibbetts, I R

    2011-07-01

    Traditional visual diet analysis techniques were compared with DNA barcoding in juvenile herbivorous rabbitfish Siganus fuscescens collected in Moreton Bay, Australia, where at least six species of seagrass occur. The intergenic spacer trnH-psbA, suggested as the optimal gene for barcoding angiosperms, was used for the first time to identify the seagrass in fish guts. Four seagrass species and one alga were identified visually from gut contents; however, there was considerable uncertainty in visual identification with 38 of 40 fish having unidentifiable plant fragments in their gut. PCR and single-strand conformational polymorphism (SSCP) were able to discriminate three seagrass families from visually cryptic gut contents. While effective in identifying cryptic gut content to family level, this novel method is likely to be most efficient when paired with visual identification techniques.

  5. 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)

  6. 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.

  7. DIETARY BIORESOURCES AND THEIR ETHNOMEDICINAL UTILITIES IN DHULE DISTRICT (MAHARASHTRA, INDIA

    Directory of Open Access Journals (Sweden)

    Y. A. AHIRRAO1, M. V. PATIL2 AND D. A. PATIL3

    2014-11-01

    The paper reports 20 plant taxa belonging to 19 species, 18 genera and 12 families of angiosperms  used for combating common human afflictions in tribal communities of Dhule district. The tribes such as Bhil, Pawara, Kokani, Mavachi, etc. depend on bioresources for their sustenance and medicinal purposes. This paper communicates only plant species which are generally used in their diet but having also medicinal significance. Majority of the taxa are under  cultivation, in thier house-gardens, whereas a  few are found wild in their vicinity. Various parts e.g. leaves, sprouts, root tubers, fruits, inflorescences, etc. find place in their dietary preparations , but consumed understanding also their medicinal utilities. As many as 14 different human diseases or complaints are cured. Their doses or recipes, if any , have been mentioned after careful enquiries  during our ethnobotanical surveys. This is an attempt to point out additional potentialities of dietary plant resources.

  8. An asterid flower from neotropical mid-Tertiary amber.

    Science.gov (United States)

    Poinar, George O; Struwe, Lena

    2016-01-01

    Fossils preserved in amber may provide significant palaeoevolutionary and biogeographical data regarding the evolution of life on Earth(1). Although amber is particularly noted for its detailed preservation of arthropods, the same degree of preservation can be found for vascular plant remains(2). Mid-Tertiary Dominican amber is a rich source for such fossils, and representatives of several angiosperm families have been described. However, no fossilized examples of the large asterid plant clade have yet been reported. Here we describe the first fossil neotropical flowers found in amber from a representative of the asterids. The asterids are one of the largest lineages of flowering plants, containing groups such as the sunflower, potato, coffee and mint families, totalling over 80,000 species(3). The new fossils are only known as flowers, more precisely corollas with stamens and styles. We here describe them as a new species, Strychnos electri sp. nov, in the plant family Loganiaceae (Gentianales). PMID:27249345

  9. Pharmacological Screening of Arceuthobium oxycedri (Dwarf Mistletoe of Juniper Forest of Pakistan

    Directory of Open Access Journals (Sweden)

    Sidney A. Crow

    2006-01-01

    Full Text Available The local population of Balochistan, Pakistan considers the Juniperus excelsa an important medicinal plant. The species is facing a grave threat by a parasitic and epiphytic angiosperm, dwarf mistletoe, Arceuthobium oxycedri (DC M. Bieb (Viscaceae. The methanolic extract of A. oxycedri was studied for its chemical composition and biologically active compounds for the first time. The extract was assayed for antibacterial, antifungal, phytotoxic, cytotoxic and insecticidal activities. The antibacterial and antifungal activities of the extract were determined against ten bacterial and ten fungal strains by agar well diffusion and disc diffusion assay. The extract was highly effective against three bacteria Pseudomonas aeruginosa, Escherchia coli, Bacillus subtillis and a fungus Candida albicans.. The phytotoxic effects showed that it was extremely toxic for Lemna acquinoctialis. It showed high cytoxicity for brine shrimps at all concentrations and was found to be significantly cytotoxic against Candida albicans when checked by flow cytometer. However, the extract was not effective against the pests tested.

  10. Plants and Humans in the Near East and the Caucasus: Ancient and Traditional Uses of Plants as Food and Medicine, a Diachronic Ethnobotanical Review

    Directory of Open Access Journals (Sweden)

    Naomi F. Miller

    2014-02-01

    Full Text Available Review of Plants and Humans in the Near East and the Caucasus: Ancient and Traditional Uses of Plants as Food and Medicine, a Diachronic Ethnobotanical Review (2 vols. Vol. 1: The Landscapes. The Plants: Ferns and Gymnosperms. Vol. 2: The Plants: Angiosperms. Diego Rivera Núñez, Gonzalo Matilla Séiquer, Concepción Obón, Francisco Alcaraz Ariza. 2011. Ediciones de la Unverisdad de Murcia. Pp. 1056. EUR 23.76 (paperback. ISBN 978-84-15463-07-08 (2 vols., 978-84-15463-05-4 (vol. 1, 978-84-15463-06-1 (vol. 2.

  11. 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.

  12. Transgressive phenotypes and generalist pollination in the floral evolution of Nicotiana polyploids.

    Science.gov (United States)

    McCarthy, Elizabeth W; Chase, Mark W; Knapp, Sandra; Litt, Amy; Leitch, Andrew R; Le Comber, Steven C

    2016-01-01

    Polyploidy is an important driving force in angiosperm evolution, and much research has focused on genetic, epigenetic and transcriptomic responses to allopolyploidy. Nicotiana is an excellent system in which to study allopolyploidy because half of the species are allotetraploids of different ages, allowing us to examine the trajectory of floral evolution over time. Here, we study the effects of allopolyploidy on floral morphology in Nicotiana, using corolla tube measurements and geometric morphometrics to quantify petal shape. We show that polyploid morphological divergence from the intermediate phenotype expected (based on progenitor morphology) increases with time for floral limb shape and tube length, and that most polyploids are distinct or transgressive in at least one trait. In addition, we show that polyploids tend to evolve shorter and wider corolla tubes, suggesting that allopolyploidy could provide an escape from specialist pollination via reversion to more generalist pollination strategies. PMID:27501400

  13. Chemical composition and palaeobotanical origin of Miocene resins from Kerala–Konkan Coast, western India

    Indian Academy of Sciences (India)

    Suryendu Dutta; Monalisa Mallick; Runcie Paul Mathews; Ulrich Mann; Paul F Greenwood; Rakesh Saxena

    2010-10-01

    The terpenoid composition of resins from the Miocene lignite horizons from the Kerala –Konkan Coast,western India was analyzed by Curie-point pyrolysis –gas chromatography –mass spectrometry (Cupy –GC –MS).The major pyrolysates were cadalene-based bicyclic sesquiterpenoids including some C30-C31 bicadinenes and bicadinanes typical of dammar resin from angiosperm plants of Dipterocarpaceae family.These plants are typically supported by tropical climates which the western Indian region was known to have experienced during early Tertiary period.The present study suggests that these palaeoclimatic conditions persisted until at least the Miocene epoch.These sesquiterpenoids which are commonly detected in many SE Asian crude oils may be utilised as useful biomarkers for petroleum exploration in the western Indian region.

  14. Species composition and minimum sampling area of a riparian mixed broadleaved-Korean pine forest in Changbai Mountain Nature Reserve

    Institute of Scientific and Technical Information of China (English)

    DAI Fang-zhou; XU Dong; DENG Hong-bing

    2011-01-01

    Riparian areas are unique although often small component of the overall watershed landscape. The structure of riparian forests along Erdaobai River on the north slope of Changhai Mountain were investi- gated by using field data collected from eight sampling transects perpen- dicular to the Erdaobai River channel. Two kinds of species-area satura- tion curves were used to examine the relationship between species num- ber and minimum sampling area. The results showed that riparian gym- nosperms accounted for a high proportion of all gymnosperms in the Changbai Mountain Nature Reserve while riparian ferns and angiosperms accounted for a relatively low proportion. The average minimum sam- pling areas of riparian forest that included 60%, 80%, and 90% of the community species pool were about 85, 185, and 328 m, respectively; while those for nonriparian forest were about 275, 390, and 514 m, correspondingly.

  15. 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.

  16. Inter-sexual competition in a dioecious grass.

    Science.gov (United States)

    Mercer, Charlene A; Eppley, Sarah M

    2010-11-01

    Spatial segregation of the sexes (SSS) occurs in many dioecious angiosperms, but little data are available on the fitness advantages, if any, for males and females. We examined whether reciprocally transplanted male and female seedlings of Distichlis spicata, a dioecious grass species that exhibits extreme SSS, differed in their responses to microhabitats and competition treatments. Plants grown without conspecific competitors grew equally well in both male- or female-majority habitats, suggesting that male and female plants do not have differential resource needs at the juvenile life-history stage. However, plants subject to intra-sexual competition were significantly larger than plants subject to inter-sexual competition, suggesting that niche partitioning may occur in D. spicata.

  17. Structure,Delimitation,Nomenclature and Classification of Stomata

    Institute of Scientific and Technical Information of China (English)

    Malvey PRABHAKAR

    2004-01-01

    The paper reviews stomatal types observed in 500 species of angiosperms besides those described in the literature and deals with the problems of their structure, delimitation, nomenclature and classification. In view of the varied definitions available in the literature for subsidiaries, stomatal types and,the definition and delimitations being variously interpreted by different workers, a modified definition for the subsidiaries and stomata is presented. In accordance with the international code of nomenclature for plants, the names of the stomata widely in use are retained (rule of priority). They have been presently classified as pericytic, desmocytic, paracytic, diacytic, anisocytic, anisotricytic, isotricytic, tetracytic,staurocytic, anomocytic, cyclocytic and a good number of varieties under each type are presented. These stomatal types are recognised on the basis of their structure rather than its ontogenetic pathways.

  18. 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

    2014-09-17

    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.

  19. Isolation and characterization of a cDNA encoding a CBF transcription factor from E. globulus.

    Science.gov (United States)

    Gamboa, Maria C; Rasmussen-Poblete, Susana; Valenzuela, Pablo D T; Krauskopf, Erwin

    2007-01-01

    The transcription factors CBF/DREB play an important role during low temperature, drought and high-salt stress in higher plants. In this work, we isolated one full-length CBF cDNA clone from the angiosperm Eucalyptus globulus. The derived peptide sequence reveals that it encodes a transcriptional activator that has all the characteristic motifs present in CBF proteins previously described in Arabidopsis and tomato. RT-PCR analysis shows that EgCBF1 is transiently induced in E. globulus seedlings that had been exposed to low temperature within the first 15 min. These results suggest that the isolated CBF gene participates in the cold responsive pathway of E. globulus.

  20. The Genome of a Southern Hemisphere Seagrass Species (Zostera muelleri)1[OPEN

    Science.gov (United States)

    Golicz, Agnieszka A.; Paterson, Andrew H.; Sablok, Gaurav; Krishnaraj, Rahul R.; Chan, Chon-Kit Kenneth; Batley, Jacqueline; Ralph, Peter J.

    2016-01-01

    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