Sample records for earwig anisolabis maritima

  1. Morphological characterization of the antennal sensilla of t he earwig Anisolabis maritima (Dermaptera: Carcinophoridae) with reference to their probable functions.

    PubMed

    Al-Dosary, Mona Mohammed

    2009-07-01

    The earwig, Anisolabis maritima (Dermaptera: Carcinophoridae), is one of the most significant insects in KSA because, it was recorded in Saudi Arabia as a beneficial predator on eggs and newly hatched larvae of the red palm weevil, Rhyncophorus ferrugineus. We examined the external morphology of the antennal sensilla of males and females of A. maritima using scanning electron microscopy (SEM). The filiform antennae of A. maritima were of the conventional type comprising a basal scape, pedicle and a long, thread-like flagellum, which was composed of 12 flagellomeres of males and 16 flagellomeres of females. Six morphologically unique sensillar types were found and described on the antennae of males and females of A. maritima. Of those identified, there were three types of porous trichoid sensilla (long, curved and arcuate), and two types of basiconic sensilla (short and curved), and one type of aporous trichoid sensilla. The shape, external morphology and array of sensilla on the antennae of males and females of A. maritima were similar. PMID:23961038

  2. Earwigs

    E-print Network

    Mott, Dale; Jackman, John A.

    2004-08-06

    glands. However, the most common complaint against the earwig is its mere presence in homes and apartments. The earwig?s name comes from a European superstition that the insect would enter the ear of a sleeping person and bore into the brain. Biology...- ment their diet with various forms of decaying organic matter. They may also feed on mosses, lichens, algae, fungi and more. Indoors, they may feed on houseplants or sweet, oily or greasy foods. Earwigs are considered temporary pests in land- scapes...

  3. Earwigs 

    E-print Network

    Mott, Dale; Jackman, John A.

    2004-08-06

    . ? Indoors, seek out and eliminate harborage areas attractive to earwigs, such as leaky plumbing or other high-humidity areas. Mechanical methods: If only an occasional ear- wig is found indoors, remove it with a broom, dust- pan or vacuum. If you often... will not solve the prob- lem of earwigs entering the building and should be used only as a supplement to outdoor efforts. Boric acid or aerosol insecticides labeled for indoor use are effective when used around baseboards, carpet edges, door and window frames...

  4. THE CAVERNICOLOUS FAUNA OF HAWAIIAN LAVA TUBES 12. A new species of blind troglobitic earwig (Dermaptera: Carcinophoridae), with a revision ofthe related surface-living earwigs of the Hawaiian Islands1

    Microsoft Academic Search

    A. Brindle

    The first known species of blind troglobitic earwig, Anisolabis howarthi, is described from a pair found in caves on the island of Hawaii. The species is related to a complex of surface- living species hitherto knowrn under the name of Anisolabis perkinsi. This complex has been found to include, in addition to A. perkinsi, 4 new species, A. hawaiiensis, A.

  5. Asymmetric forceps increase fighting success among males of similar size in the maritime earwig

    PubMed Central

    Munoz, Nicole E.; Zink, Andrew G.

    2012-01-01

    Extreme asymmetric morphologies are hypothesized to serve an adaptive function that counteracts sexual selection for symmetry. However direct tests of function for asymmetries are lacking, particularly in the context of animal weapons. The weapon of the maritime earwig, Anisolabis maritima, exhibits sizeable variation in the extent of directional asymmetry within and across body sizes, making it an ideal candidate for investigating the function of asymmetry. In this study, we characterized the extent of weapon asymmetry, characterized the manner in which asymmetric weapons are used in contests, staged dyadic contests between males of different size classes and analyzed the correlates of fighting success. In contests between large males, larger individuals won more fights and emerged as the dominant male. In contests between small males, however, weapon asymmetry was more influential in predicting overall fighting success than body size. This result reveals an advantage of asymmetric weaponry among males that are below the mean size in the population. A forceps manipulation experiment suggests that asymmetry may be an indirect, correlate of a morphologically independent factor that affects fighting ability. PMID:22984320

  6. Controlling earwigs P.J. Pellitteri

    E-print Network

    Balser, Teri C.

    Michigan shoreline. But in the years since, earwig infestations have spread fast across Wisconsin. The name Newport, Rhode Island in 1901. Until 1982 European earwig reports in Wisconsin were limited to the Lake. In Wisconsin, pairs of earwigs overwinter by digging 2-3 inches into the soil to hibernate: Sometime during

  7. Suriana maritima (Cultivated) 

    E-print Network

    Hugh D. Wilson

    2011-08-10

    Galveston Bay, Texas are limited. In this study, the effects of repeated nutrient additions in monospecific plots of Spartina alterniflora, Batis maritima¸ and Salicornia virginica as well as mixed plots of B. maritima and S. virginica were studied over 15...

  8. An earwig in Late Cretaceous Vendean amber (Dermaptera)

    E-print Network

    Engel, Michael S.; Perrichot, Vincent

    2014-12-01

    A new fossil earwig nymph is described and figured from the Late Cretaceous (Cenomanian to Santonian) amber of Vendée, northwestern France. Vendeenympha gravesi n. gen. and sp., is distinguished from previously recorded nymphs in other French fossil...

  9. Maternal Food Regurgitation to Nymphs in Earwigs (Forficula auricularia)

    E-print Network

    Kölliker, Mathias

    Maternal Food Regurgitation to Nymphs in Earwigs (Forficula auricularia) Michael Staerkle & Mathias of larvae / nymphs is also found (Costa 2006). Paren- tal care in (sub-) social insects is generally-to-mouthpart contacts between parents and their larvae / nymphs (e.g. Pukowski 1933; Lamb 1976; Vancassel 1984; Liu 1991

  10. New mid-Cretaceous earwigs in amber from Myanmar (Dermaptera)

    E-print Network

    Engel, Michael S.; Grimaldi, David A.

    2014-01-29

    to some crops as they will feed on foliage as well as small arthropods and such feeding can be detrimental to seedlings or soft-fleshed fruits (e.g., Bower, 1992; Alford, 2007). In fact, earwigs can be quite beneficial. For ex- ample, the common...., 2012), and even in maize fields (Sueldo de Escaño & Virla, 2009). The Dermaptera comprise about 2000 described living species, segregated into 11 families (Engel & Haas, 2007). All living species belong to the suborder Neodermaptera (including...

  11. The chemical defense in larvae of the earwig Forficula auricularia.

    PubMed

    Gasch, Tina; Vilcinskas, Andreas

    2014-08-01

    Larvae of the European earwig, Forficula auricularia, possess a paired pygidial gland with yet unknown content and function. We used gas chromatography-mass spectrometry to analyze the larval secretions revealing the presence of 2-methyl-1,4-benzoquinone, 2-ethyl-1,4-benzoquinone, n-tridecane and n-pentadecane. Based on our recent discovery that the morphologically-distinct abdominal glands of adult earwigs produce secretions with antibacterial, antifungal and nematicidal activity, we propose that the pygidial glands mediate chemical defenses in the larvae. We next considered whether the defensive functions of larval secretions include repellent activity against sympatric predators. Therefore, we tested the effects of larval secretions on foraging workers of the ant species Myrmica rubra, the actively hunting spiders Anyphaena accentuata and Philodromus aureolus and the net-hunting spider Pholcus phalangioides in laboratory feeding assays. The secretion is released in response to ant attacks, and discourages feeding in M. rubra, however, it does not discourage feeding in spiders. Our results suggest that earwigs use different glands during ontogenesis to produce secretions that play roles in chemical defense against predators such as ants. PMID:24879968

  12. Beta maritima: the Origin of Beets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Along the undisturbed shores, especially of the Mediterranean Sea and the European North Atlantic Ocean, is a widespread plant called Beta maritima (Beta vulgaris subspecies maritima) by the botanists, or more commonly sea beet. Nothing for the inexperienced observer's eye distinguishes it from surr...

  13. Earwigs (Labidura riparia) mimic rotting-flesh odor to deceive vertebrate predators.

    PubMed

    Byers, John A

    2015-08-01

    Many insects repel predators with caustic chemicals, while insects mimicking odors of wastes/dead insects to fool predators have not been documented. We found that the shore earwig, Labidura riparia (Dermaptera: Labiduridae) when bitten by anole lizards, Anolis carolinenesus, spits a rotting-flesh odor that deceives these insectivores into rejecting prey. Once a lizard attacked and rejected an earwig, the lizard did not attack another earwig during several weeks despite consuming other prey, indicating associative learning after one trial. The fetid odor was found in the head-prothorax containing salivary glands of both male and female earwigs and was comprised of ?100 ng dimethyl disulfide and ?600 ng dimethyl trisulfide. Nymphs had <5 ng of either compound. Adults also spit odorous sulfides after prolonged attacks by harvester ants, Pogonomyrmex rugosus, who were only deterred by the earwig's forceps. Sulfides released by the earwig are similar to odors of carrion/feces, which may be innately repulsive to some vertebrate predators. The mean initial discharge percentage (IDP) of sulfides from a cohort of earwigs was 62 %; however, IDPs of individuals were highly variable (3-99 %; mean 57 %). The discharge refill time (DRT) to refill 50 % of the earwig's allomone reservoir was estimated at 13 h. A positive relationship in sulfide amounts with body weight was found only in females in 2009, suggesting metabolic cost tradeoffs were revealed when sulfide content was half that in 2010. This is the first report of insects releasing sulfur-containing compounds that may mimic carrion-fecal odors as a deceptive defense against vertebrate predators. PMID:26071006

  14. Effects of salinity changes on growth of Ruppia maritima L

    Microsoft Academic Search

    Megan K La Peyre; Sheryl Rowe

    2003-01-01

    The ability of Ruppia maritima L. to tolerate moderate salinity changes was determined in a greenhouse study. While R. maritima has been shown to survive in salinities from 0 to 70ppt, it has been suggested that changes in salinity alone may be detrimental. We tested the hypothesis that along the northern shore of the Gulf of Mexico, R. maritima may

  15. Transitional fossil earwigs - a missing link in Dermaptera evolution

    PubMed Central

    2010-01-01

    Background The Dermaptera belongs to a group of winged insects of uncertain relationship within Polyneoptera, which has expanded anal region and adds numerous anal veins in the hind wing. Evolutional history and origin of Dermaptera have been in contention. Results In this paper, we report two new fossil earwigs in a new family of Bellodermatidae fam. nov. The fossils were collected from the Jiulongshan Formation (Middle Jurassic) in Inner Mongolia, northeast China. This new family, characterized by an unexpected combination of primitive and derived characters, is bridging the missing link between suborders of Archidermaptera and Eodermaptera. Phylogenetic analyses support the new family to be a new clade at the base of previously defined Eodermaptera and to be a stem group of (Eodermaptera+Neodermaptera). Conclusion Evolutional history and origin of Dermaptera have been in contention, with dramatically different viewpoints by contemporary authors. It is suggested that the oldest Dermaptera might possibly be traced back to the Late Triassic-Early Jurassic and they had divided into Archidermaptera and (Eodermaptera+Neodermaptera) in the Middle Jurassic. PMID:21062504

  16. Two new polyhydroxylated sterols from Ruppia maritima.

    PubMed

    Dellagreca, M; Fiorentino, A; Monaco, P; Zarrelli, A

    2001-01-01

    Two new sterols have been isolated from the aquatic plant Ruppia maritima and their structures were established as (24R) ergosta-8,22-diene-3 beta,6 beta,7 alpha-triol (1) and (24R) ergosta-8(14),22-diene-3 beta,6 beta,7 alpha-triol (2) on the basis of spectroscopic analysis. PMID:11561443

  17. Two New Polyhydroxylated Sterols from Ruppia maritima

    Microsoft Academic Search

    Marina Dellagreca; Antonio Fiorentino; Pietro Monaco; Armando Zarrelli

    2001-01-01

    Two new sterols have been isolated from the aquatic plant Ruppia maritima and their structures were established as (24R) ergosta-8,22-diene-3?,6?,7?-triol (1) and (24R) ergosta-8(14),22-diene-3?,6?,7?-triol (2) on the basis of spectroscopic analysis.

  18. Predation on earwigs: A novel diet specialization within the genus Leptogenys (Formicidae: Ponerinae)

    Microsoft Academic Search

    S. Steghaus-Kovac; U. Maschwitz

    1993-01-01

    Summary Leptogenys sp. 13 (nearkraepelini) exclusively hunts on earwigs (Gonolabis electa andParalabis sp.). This unusual kind of prey specialization is shown by field data, prey midden investigations, and prey selection experiments. The adaptive value of the species' prey specialization is discussed.

  19. The earliest earwigs in amber (Dermaptera): A new genus and species from the Early Cretaceous of Lebanon

    E-print Network

    Engel, Michael S.; Ortega-Blanco, Jaime; Azar, Dany

    2011-07-01

    Rhadinolabis phoenicica Engel, Ortega-Blanco & Azar gen. et sp.n. is described and figured from two female earwigs preserved in Early Cretaceous amber from Lebanon, representing the oldest Dermaptera in amber. In addition a partial nymph is recorded...

  20. Motility and thermotactic responses of Thermotoga maritima.

    PubMed Central

    Gluch, M F; Typke, D; Baumeister, W

    1995-01-01

    Thermotoga maritima, a thermophilic eubacterium, is motile at temperatures ranging from 50 to 105 degrees C. The cells are propelled by a single flagellum which most of the time spins clockwise. Changes in the swimming direction ("tumbles") are achieved by short reversals of the direction of filament rotation. The average speed of swimming cells depends on the temperature, reaching a maximum value of about 60 microns/s at 85 degrees C. The cells show a thermotactic response to temporal temperature changes. When the temperature is raised, the rate of tumbles is increased, while decreasing temperature decreases the tumbling rate. PMID:7559332

  1. Effect of sulfate level on selenium uptake by Ruppia maritima

    Microsoft Academic Search

    F. C. Bailey; A. W. Knight; R. S. Ogle; S. J. Klaine

    1995-01-01

    Ruppia maritima (wigeongrass), the dominant aquatic macrophyte in the agricultural drainage evaporation ponds of the Central Valley of California, is a food source for various waterfowl and shorebirds. Whole-plant uptake and accumulation of selenate (SeO4?2 or Se+6), selenite (SeO3?2 or Se+4), and seleno-methionine (Se?2) by R. maritima from artificial evaporation pond water was compared over a 21 day period, and

  2. Side effects of plant protection products and biological interactions on the European earwig Forficula auricularia L.

    PubMed

    Peusens, G; Moerkens, R; Beliën, T; Gobin, B

    2009-01-01

    Plant protection products are designed to control pests but can have negative side effects on non-target arthropods thus disturbing the important population of natural enemies required for biological control. Although the European earwig, Forficula auricularia L, (Dermaptera: Forficulidae) is not considered to be a key beneficial in pome fruit, it is an important predator of several pests, e.g. woolly apple aphid and pear sucker. The impact of non-selective plant protection products at crucial moments in their (univoltine) life cycle can be of significant relevance compared to insects with numerous generations. Foliar applications in spring when nymphs are migrating into the trees can reduce the number of adults in summer and subsequently affect the population size next year. Multiple and/or combined spraying during summer on adults may have a cumulative effect resulting in less over wintering females which possibly exhibit poor reproductive performance. Previous residual contact bioassays already revealed the harmful side effect of several formulated products on adults. Insects showing sub lethal symptoms recovered partially or died eventually. As spinosad caused significant toxicological effects it was subsequently tested in 3 different dose rates on adults and N4-nymphs. We noticed not only a clear dose-response relationship but N4-nymphs proved to be more susceptible than adults; even a dilution of 1/9-th of the registered dose rate still caused a mortality of 45.5 % after 20 days. Understanding the earwig's population dynamics is essential for efficient practical biocontrol. It proves difficult to increase population levels to sufficient high numbers for optimal pest control. Local biological factors might be limiting. Therefore, we tested two hypotheses that pertain to population limitation: 1. Bird predation during summer, 2. Small mammal nest predation during winter. Enclosure experiments showed no negative bird effect on earwig densities unless large bird flocks inhabited the area. Small mammals did not actively predate the over wintering nests, although other predatory arthropods may be important. PMID:20222599

  3. The Temperature Dependent Proteomic Analysis of Thermotoga maritima

    PubMed Central

    Wang, Quanhui; Bai, Xue; Chen, Zhen; Zhao, Jingjing; Xu, Ningzhi; Liu, Siqi

    2012-01-01

    Thermotoga maritima (T. maritima) is a typical thermophile, and its proteome response to environmental temperature changes has yet to be explored. This study aims to uncover the temperature-dependent proteins of T. maritima using comparative proteomic approach. T. maritima was cultured under four temperatures, 60°C, 70°C, 80°C and 90°C, and the bacterial proteins were extracted and electrophoresed in two-dimensional mode. After analysis of gel images, a total of 224 spots, either cytoplasm or membrane, were defined as temperature-dependent. Of these spots, 75 unique bacterial proteins were identified using MALDI TOF/TOF MS. As is well known, the chaperone proteins such as heat shock protein 60 and elongation factor Tu, were up-regulated in abundance due to increased temperature. However, several temperature-dependent proteins of T. maritima responded very differently when compared to responses of the thermophile T. tengcongensis. Intriguingly, a number of proteins involved in central carbohydrate metabolism were significantly up-regulated at higher temperature. Their corresponding mRNA levels were elevated accordingly. The increase in abundance of several key enzymes indicates that a number of central carbohydrate metabolism pathways of T. maritima are activated at higher temperatures. PMID:23071576

  4. Advanced morphology and behaviour of extinct earwig-like cockroaches (Blattida: Fuziidae fam. nov.)

    NASA Astrophysics Data System (ADS)

    Vršanský, Peter; Liang, Jun-Hui; Ren, Dong

    2009-12-01

    We describe the extinct cockroach family Fuziidae fam. nov., represented by Fuzia dadao gen. et sp. nov. from the ?Bathonian (168 Ma) Middle Jurassic sediments of Daohugou, Inner Mongolia, China. Males are characterized by unique, long and narrow bodies with a notch on forceps of earwig-like cerci, which attaches to the long external ovipositor during courtship. In a combination with the presence of male tergal glands, it appears the most advanced form of reproduction in the nearly 300 Myr history of long external ovipositor-bearing cockroaches. Its advanced morphology significantly supports attribution of living and fossil cockroaches within a single order Blattida.

  5. Waterbird impacts on widgeongrass Ruppia maritima in a Mediterranean wetland: comparing bird groups and seasonal effects

    E-print Network

    Green, Andy J.

    Waterbird impacts on widgeongrass Ruppia maritima in a Mediterranean wetland: comparing bird groups. Waterbird impacts on widgeongrass Ruppia maritima in a Mediterranean wetland: comparing bird groups Ruppia maritima in eleven fish ponds within Don~ana Natural Park (SW Spain). Separate exclosure designs

  6. Efficient rooting and acclimation of micropropagated Ruppia maritima Loisel.

    PubMed

    Woodhead; Bird

    1998-08-01

    An efficient protocol for rooting and acclimation of in vitro propagated Ruppia maritima was the focus of this research. The effects of four dilutions of a nutrient medium (f) and four different concentrations of sodium bicarbonate on rooting production were investigated. The optimal rooting medium was determined to be f/2 with 0.25 mM sodium bicarbonate in 5 ppt synthetic seawater at a pH of 7.5. Cultures of R. maritima were found to be photosynthetically inactive as measured by oxygen evolution in sucrose-based multiplication medium but were physiologically capable of adjusting to autotrophism once transferred to a bicarbonate medium. This transition was immediate and comparable to cultures that had acclimated in bicarbonate-based medium for 21 days. Ruppia maritima rooted onto coconut fiber mats and unanchored plants were acclimated in outdoor aquaria during May 1995. The results of these studies showed that micropropagated R. maritima can be acclimated easily and effectively at a low cost in aquaria, making R. maritima a useful seagrass species for restoration and mitigation projects. PMID:9701636

  7. The complete mitochondrial genome of the geophilomorph centipede Strigamia maritima.

    PubMed

    Robertson, Helen E; Lapraz, François; Rhodes, Adelaide C; Telford, Maximilian J

    2015-01-01

    Strigamia maritima (Myriapoda; Chilopoda) is a species from the soil-living order of geophilomorph centipedes. The Geophilomorpha is the most speciose order of centipedes with over a 1000 species described. They are notable for their large number of appendage bearing segments and are being used as a laboratory model to study the embryological process of segmentation within the myriapods. Using a scaffold derived from the recently published genome of Strigamia maritima that contained multiple mitochondrial protein-coding genes, here we report the complete mitochondrial genome of Strigamia, the first from any geophilomorph centipede. The mitochondrial genome of S. maritima is a circular molecule of 14,938 base pairs, within which we could identify the typical mitochondrial genome complement of 13 protein-coding genes and 2 ribosomal RNA genes. Sequences resembling 16 of the 22 transfer RNA genes typical of metazoan mitochondrial genomes could be identified, many of which have clear deviations from the standard 'cloverleaf' secondary structures of tRNA. Phylogenetic trees derived from the concatenated alignment of protein-coding genes of S. maritima and >50 other metazoans were unable to resolve the Myriapoda as monophyletic, but did support a monophyletic group of chilopods: Strigamia was resolved as the sister group of the scolopendromorph Scolopocryptos sp. and these two (Geophilomorpha and Scolopendromorpha), along with the Lithobiomorpha, formed a monophyletic group the Pleurostigmomorpha. Gene order within the S. maritima mitochondrial genome is unique compared to any other arthropod or metazoan mitochondrial genome to which it has been compared. The highly unusual organisation of the mitochondrial genome of Strigamia maritima is in striking contrast with the conservatively evolving nuclear genome: sampling of more members of this order of centipedes will be required to see whether this unusual organization is typical of the Geophilomorpha or results from a more recent reorganisation in the lineage leading to Strigamia. PMID:25794168

  8. Complete Genome Sequence of an Evolved Thermotoga maritima Isolate

    PubMed Central

    Singh, Raghuveer; Gradnigo, Julien; White, Derrick; Lipzen, Anna; Martin, Joel; Schackwitz, Wendy; Moriyama, Etsuko

    2015-01-01

    Thermotoga maritima is a hyperthermophilic bacterium with a small genome (1.86 Mbp). Genome resequencing of Tma200, a derivative produced by experimental microbial evolution, revealed the occurrence of deletions and substitution mutations. Their identification contributes to a better understanding of genome instability in this organism. PMID:26021931

  9. ROOT-EXUDED OXYGEN IN THE AQUATIC ANGIOSPERM 'RUPPIA MARITIMA'

    EPA Science Inventory

    The potential impact of oxygen from roots on the source of inorganic nitrogen for Ruppia maritima L. (Potamogetonales) was investigated in laboratory experiments. Roots released oxygen at an average rate of 2 to 3 micrograms O2 (mg dry wt)/hr. A distinctive oxygenated zone with a...

  10. Effects of tributyltin (TBT) on the seagrass Ruppia maritima

    Microsoft Academic Search

    H. F. Jensen; M. Holmer; I. Dahllöf

    2004-01-01

    The effects of tributyltin (TBT) on the seagrass Ruppia maritima were studied in two growth experiments. Plants were sampled at stations in Odense Fjord and Lunkebugten, Denmark, and replanted in reference sediment without TBT, reference sediment spiked with TBT, and in impacted sediment sampled in the highly TBT contaminated (7–57 ?gkg?1dw) Odense Fjord. Plant performance was studied at weekly intervals

  11. Structural characteristics of a diatom community epiphytic on Ruppia maritima

    Microsoft Academic Search

    Michael J. Sullivan

    1977-01-01

    Epiphytic diatoms were collected from both the leaves and internodes of Ruppia maritima in a New Jersey salt marsh during the growing season of the host plant. Community diversity (H' and the number of diatom taxa) values were initially high as Ruppia began its growth, but quickly dropped to sustained low levels as vegetative growth of the host ceased and

  12. Wigeongrass (Ruppia maritima L.): a literature review

    USGS Publications Warehouse

    Kantrud, H.A.

    1991-01-01

    Wigeongrass (Ruppia maritima L.) is a submersed macrophyte of nearly cosmopolitan distribution and worldwide importance as a waterfowl food. Unfortunately, the plant no longer inhabits vast areas disturbed by human activities. Taxonomic status of the plant is uncertain, especially in North America. In mild climates, in habitats subject to environmental extremes, the plant behaves as an annual (vegetation perishes), or as a perennial in deeper, more stable habitats (some vegetative parts grow year round). Drupelets (seeds) provide a mechanism for wigeongrass to survive periods of drought and excessive water salinity. These sexual propagules can be washed ashore or carried by birds or fish for long distances.Wigeongrass mostly occurs in temporarily to permanently flooded mesohaline-hyperhaline estuarine wetlands, but it also occurs inland in fresh to hypersaline palustrine and lacustrine wetlands. Most populations inhabit warm, relatively unpolluted, and well lit waters 2S conditions. Turbidity frequently limits wigeongrass growth in waters overlying easily suspendible bottom substrates.Wigeongrass often occurs in monotypic stands, yet grows with many other submersed and emergent macrophytes. Dominance in certain wetlands sometimes alternates with dominance by other submersed macrophytes as salinities, seasonal temperature cycles, or other environmental factors change. The shading effect of metaphytic, planktonic, or epiphytic algae often reduces production.Wigeongrass and its detritus provide food and cover for a large invertebrate biota, although direct consumption of the living plants is minimal. Wigeongrass beds in coastal wetlands are heavily used by fish. The plant is recognized worldwide as an important food of migrant and wintering waterfowl, wading birds, and shorebirds. In subtropical climates, wintering waterfowl can quickly consume entire stands.Propagation and management of wigeongrass has occurred for nearly 60 years in the southern and eastern United States. During the seventies and eighties, sophisticated water level and salinity management techniques have been developed to encourage growth of the plant.Future research should concentrate on determining the means to reduce light-limiting turbidity in many wetland types; understanding the ways in which human activities on and near wetlands affect wigeongrass production; and developing reliable and predictable techniques to stimulate wigeongrass production by water level manipulations and other means in different environmental settings. Trophic interactions and the effects of biomanipulation of fish populations in managed wigeongrass habitat--now little understood--also require more study.

  13. CALOPLACA MARITIMA , A MISUNDERSTOOD SPECIES IN WESTERN EUROPE

    Microsoft Academic Search

    Ulf ARUP

    1997-01-01

    Caloplaca maritimaB. de Lesd. is a marine to maritime species occurring in western Europe. It was first described as a variety ofC. citrina(Hoffm.) Th. Fr., but in 1953 was transferred to specific level. Since thenC. maritimahas been more or less forgotten and\\/or misunderstood, mainly due to confusion withC. ruderum(Malbr.) J. R. Laundon,C. interfulgens(Nyl.) J. Steiner, andC. marina(Wedd.) Zahlbr. The present

  14. Note on organic dormancy of estuarine Ruppia maritima L. seeds

    Microsoft Academic Search

    Hyun Jung Cho; Yvonne L. Sanders

    2009-01-01

    Information on seed dormancy is one of the primary requirements for successful seedling propagation of submerged aquatics\\u000a and seagrass. Studies on Ruppia\\u000a maritima seed germination have been done, but the presence, requirements, and the types of dormancy have not been well understood.\\u000a A laboratory study was conducted to understand presence and types of organic dormancy of the seeds of estuarine

  15. Effects of seed ingestion and herbivory by waterfowl on seedling establishment: a field experiment with wigeongrass Ruppia maritima in

    E-print Network

    Green, Andy J.

    with wigeongrass Ruppia maritima in Doñana, south-west Spain Jordi Figuerola* and Andy J. Green Department (shov- eler, Anas clypeata) on the survival of wigeongrass Ruppia maritima seedlings in the field

  16. NUTRITIONAL REQUIREMENTS OF THE SUBMERGED ANGIO-SPERM 'RUPPIA MARITIMA' IN ALGAE-FREE CULTURE

    EPA Science Inventory

    Ruppia maritima has the potential to become a model laboratory organism for studies with submerged aquatic vascular plants. The present study demonstrated that algae-free R. maritima grew well in a defined medium without sediment. Growth was a linear response to photon flux densi...

  17. Gene Transfer and Genome Plasticity in Thermotoga maritima, a Model Hyperthermophilic Species

    Microsoft Academic Search

    Emmanuel F. Mongodin; Ioana R. Hance; Robert T. DeBoy; Steven R. Gill; Sean Daugherty; Robert Huber; Claire M. Fraser; Karl Stetter; Karen E. Nelson

    2005-01-01

    The genome sequence of the hyperthermophilic bacterium Thermotoga maritima MSB8 presents evidence for lateral gene transfer events between bacterial and archaeal species. To estimate the extent of genomic diversity across the order Thermotogales, a comparative genomic hybridization study was initiated to compare nine Thermotoga strains to the sequenced T. maritima MSB8. Many differences could be associated with substrate utilization patterns,

  18. Effects of tributyltin (TBT) on the seagrass Ruppia maritima.

    PubMed

    Jensen, H F; Holmer, M; Dahllöf, I

    2004-10-01

    The effects of tributyltin (TBT) on the seagrass Ruppia maritima were studied in two growth experiments. Plants were sampled at stations in Odense Fjord and Lunkebugten, Denmark, and replanted in reference sediment without TBT, reference sediment spiked with TBT, and in impacted sediment sampled in the highly TBT contaminated (7-57 microg kg (-1) dw) Odense Fjord. Plant performance was studied at weekly intervals for 3-4 weeks, by measuring net photosynthetic activity, respiration, relative growth rate (RGR) and number of leaves. Net photosynthetic activity in plants from spiked and impacted sediment was reduced by up to 60% relative to reference plants. Respiration both increased and decreased in response to TBT exposure, while RGR was generally lower in plants from contaminated sediments (reduced by 8-25%). The effects of spiked and impacted sediment differed between the experiments, which could be partly explained by the bioavailability of TBT in the two treatments, but also by adaptation of the plants from Odense Fjord to TBT. Measurements of enhanced TBT concentrations in the sediments in Odense Fjord suggest an impact of TBT on R. maritima is possible under in situ conditions. PMID:15476835

  19. Relationship between waterfowl and the seagrass Ruppia maritima in a Southwestern Atlantic coastal lagoon

    Microsoft Academic Search

    Alejandro Bortolus; Oscar O. Iribarne; Mariano M. Martínez

    1998-01-01

    We evaluated the distribution of waterfowl in relation to a seagrass (Ruppia maritima) patch, to infauna, and on its relationship with substrate characteristics. An experiment performed in the Mar Chiquita coastal\\u000a lagoon (37°46?S, 57°27?W; Argentina) was used to evaluate the effect of herbivory on widgeon grass,R. maritima. Control plots of equal size, located between bird exclosures, were exposed to herbivory.

  20. Culture studies of Ruppia maritima L. in bicarbonate- and sucrose-based media

    Microsoft Academic Search

    K. T. Bird; M. S. Brown; T. T. Henderson; C. E. O'Hara; J. M. Robbie

    1996-01-01

    Media were compared for culture of the estuarine plant Ruppia maritima L. The best inorganic nutrient amendment was based on f\\/2 basal enrichment salts in artificial seawater. Using f\\/2 basal enrichments, Ruppia maritima could be grown in media where either bicarbonate or sucrose was provided as the major carbon source. The cytokinin 2iP (6[?,?-dimethylallylamino]-purine) stimulated more growth than BA (N6-benzylaminopurine)

  1. Development and characterization of nineteen polymorphic microsatellite loci from seaside alder, Alnus maritima

    Microsoft Academic Search

    Stacey L. Lance; Kenneth L. Jones; Cris Hagen; Travis C. Glenn; J. Matthew Jones; J. Phil Gibson

    2009-01-01

    We isolated and characterized 19 microsatellite loci from the endangered seaside alder, Alnus maritima. Loci were screened in 24 individuals of A. maritima and four individuals of its congener the hazel alder, A. serrulata. The number of alleles per locus ranged from 2 to 6, observed heterozygosity ranged from 0 to 0.952, and the probability\\u000a of identity values ranged from

  2. Antialgal ent-labdane diterpenes from Ruppia maritima.

    PubMed

    DellaGreca, M; Fiorentino, A; Isidori, M; Monaco, P; Zarrelli, A

    2000-12-01

    Seven ent-labdane diterpenes have been isolated from Ruppia maritima. The structures 15,16-epoxy-ent-labda-8(17),13(16),14-trien-19-al; 15,16-epoxy-ent-labda-8(17),13(16),14-trien-19-ol acetate; methyl 15,16-epoxy-12-oxo-ent-labda-8(17),13(16),14-trien-19-oate; 15,16-epoxy-ent-labd-8(17),13E-dien-15-ol and 13-oxo-15,16-bis-nor-ent-labd-8(17)-ene have been assigned to the five new compounds by spectroscopic means and chemical correlations. The phytotoxicity of the diterpenes has been assessed using the alga Selenastrum capricornutum as organism test. PMID:11140523

  3. Antialgal ent-labdane diterpenes from Ruppia maritima

    Microsoft Academic Search

    Marina DellaGreca; Antonio Fiorentino; Marina Isidori; Pietro Monaco; Armando Zarrelli

    2000-01-01

    Seven ent-labdane diterpenes have been isolated from Ruppia maritima. The structures 15,16-epoxy-ent-labda-8(17),13(16),14-trien-19-al; 15,16-epoxy-ent-labda-8(17),13(16),14-trien-19-ol acetate; methyl 15,16-epoxy-12-oxo-ent-labda-8(17),13(16),14-trien-19-oate; 15,16-epoxy-ent-labd-8(17),13E-dien-15-ol and 13-oxo-15,16-bis-nor-ent-labd-8(17)-ene have been assigned to the five new compounds by spectroscopic means and chemical correlations. The phytotoxicity of the diterpenes has been assessed using the alga Selenastrum capricornutum as organism test.

  4. Variability of volatile constituents in Artemisia maritima in western Himalaya.

    PubMed

    Jaitak, Vikas; Singh, Bikram; Kaul, V K

    2008-05-10

    Chemical composition of the essential oil of Artemisia maritima, collected from three different high altitude locations in western Himalaya was studied by gas-chromatography mass spectrometry. Twenty-five constituents were identified in the oil distilled from the sample from Pooh, of which 1,8-cineole (23.8%) and chrysanthenone (17.54%) were the major constituents. Twenty volatile constituents were identified from the sample collected from Rhongtong pass, of which chrysanthenone (38.1%) and 1,8-cineole (37.3%) were the major constituents. In the oil distilled from the sample collected from Lahaul-Spiti 28 constituents were identified, of which 1,8-cineole (44.22%), camphor (9.16%) and borneol (10.94%) were the major constituents. In this sample chrysanthenone was present in very low percentage. PMID:18569692

  5. The flowering pattern of the perennial herb Lobularia maritima: an unusual case in the Mediterranean basin

    NASA Astrophysics Data System (ADS)

    Xavier Picó, F.; Retana, Javier

    2001-08-01

    In plant communities of the Mediterranean Basin most plant species reach their blooming peak in spring and have characteristically short flowering periods of two-three months. The perennial herb Lobularia maritima represents an exception to these characteristics, because it flowers for almost 10 months, and has its flowering peak in autumn. In this five-year study, we describe the flowering pattern of L. maritima at the population and community levels. Despite the unusually extended flowering period of L. maritima, the species showed characteristic low among-year variability in the length of the flowering period but large interannual variation in the distribution of flowers throughout the flowering period. The flowering pattern (unimodal or bimodal) of L. maritima individuals differed among the five years, suggesting that L. maritima plants are plastic enough to tailor their flowering to variable environmental conditions. We conclude that flowering phenology of L. maritima represents a very particular case in the plant community studied, and the influence of abiotic and biotic factors on the phenology of this species is discussed.

  6. A seascape genetic analysis reveals strong biogeographical structuring driven by contrasting processes in the polyploid saltmarsh species Puccinellia maritima and Triglochin maritima.

    PubMed

    Rouger, R; Jump, A S

    2014-07-01

    Little is known about the processes shaping population structure in saltmarshes. It is expected that the sea should act as a powerful agent of dispersal. Yet, in contrast, import of external propagules into a saltmarsh is thought to be small. To determine the level of connectivity between saltmarsh ecosystems at a macro-geographical scale, we characterized and compared the population structure of two polyploid saltmarsh species, Puccinellia maritima and Triglochin maritima based on a seascape genetics approach. A discriminant analysis of principal components highlighted a genetic structure for both species arranged according to a regional pattern. Subsequent analysis based on isolation-by-distance and isolation-by-resistance frameworks indicated a strong role of coastal sediment transport processes in delimiting regional structure in P. maritima, while additional overland propagule dispersal was indicated for T. maritima. The identification and comparison of regional genetic structure and likely determining factors presented here allows us to understand the biogeographical units along the UK coast, between which barriers to connectivity occur not only at the species level but at the ecosystem scale. This information is valuable in plant conservation and community ecology and in the management and restoration of saltmarsh ecosystems. PMID:24862943

  7. Do Conditions During Dormancy Influence Germination of Suaeda maritima?

    PubMed Central

    Wetson, Anne M.; Cassaniti, Carla; Flowers, Timothy J.

    2008-01-01

    Background and Aims Seeds of annual halophytes such as Suaeda maritima experience fluctuating salinity, hydration, hypoxia and temperature during dormancy. Germination then occurs in one flush of 2–3 weeks after about 5 months of winter dormancy during which time the seeds can remain in saline, often waterlogged soil. The aim of this study was to investigate the effect of simulated natural conditions during dormancy on germination and to compare this with germination following the usual conditions of storing seeds dry. The effects of hydration, salinity, hypoxia and temperature regimes imposed during dormancy on germination were investigated. Also looked at were the effects of seed size on germination and the interaction between salinity during dormancy and salinity at the time of germination. Methods Various pre-treatments were imposed on samples of seeds that had been stored dry or wet for different periods of time during the 5 months of natural dormancy. Subsequent germination tests were carried out in conditions that simulated those found in the spring when germination occurs naturally. Various salinities were imposed at germination for a test of interaction between storage salinity and salinity at germination. Key Results A temperature of about 15 °C was needed for germination and large seeds germinated earlier and better than small seeds. Cold seawater pre-treatment was necessary for good germination; the longer the saline pre-treatment during the natural dormancy period the better the germination. There appeared to be no effect of any specific ion of the seawater pre-treatment on germination and severe hypoxia did not prevent good germination. A short period of freezing stimulated early germination in dry-stored seed. Storage in cold saline or equivalent osmotic medium appeared to inhibit germination during the natural dormancy period and predispose the seed to germinate when the temperature rose and the salinity fell. Seeds that were stored in cold wet conditions germinated better in saline conditions than those stored dry. Conclusions The conditions under which seeds of S. maritima are stored affect their subsequent germination. Under natural conditions seeds remain dormant in highly saline, anoxic mud and then germinate when the temperature rises above about 15 °C and the salinity is reduced. PMID:18369238

  8. Similarity and divergence between the RNA polymerase ? subunits from hyperthermophilic Thermotoga maritima and mesophilic Escherichia coli bacteria

    Microsoft Academic Search

    Frederique Braun; Fanny B. Marhuenda; Amelie Morin; Laetitia Guevel; Fabrice Fleury; Masayuki Takahashi; Vehary Sakanyan

    2006-01-01

    The ? subunit (?Tm) of Thermotoga maritima RNA polymerase has been characterized to investigate its role in transcriptional regulation in one of the few known anaerobic hyperthermophilic bacteria. The highly thermostable ?Tm shares 54% similarity with its Escherichia coli analogue (?Ec). The T. maritima rpoA gene coding the ? subunit does not complement the thermosensitive rpoA112 mutation of E. coli.

  9. Nonomuraea maritima sp. nov., isolated from coastal sediment.

    PubMed

    Xi, Lijun; Zhang, Limin; Ruan, Jisheng; Huang, Ying

    2011-11-01

    A novel actinomycete, strain FXJ7.203(T), was isolated from a coastal sediment sample collected in Bohai Bay, China. In 16S rRNA gene sequence analyses, strain FXJ7.203(T) always formed a unique monophyletic line within the genus Nonomuraea and was most closely related to Nonomuraea turkmeniaca (97.9 %), Nonomuraea candida (97.8 %), Nonomuraea helvata (97.7 %) and Nonomuraea rubra (97.5 %). Morphological and chemotaxonomic characteristics supported the allocation of the strain to the genus Nonomuraea. The polar lipid profile showed that its phospholipid type was PIV. The major fatty acids were iso-C(16 : 0), C(17 : 1)?6c, iso-C(16 : 1) G, 10-methyl C(17 : 0) and iso-C(15 : 0). The major menaquinone was MK-9(H(4)) with minor amounts of MK-9(H(2)), MK-9(H(0)) and MK-9(H(6)). The results of physiological and biochemical tests allowed differentiation of strain FXJ7.203(T) from closely related species. Based on the genotypic and phenotypic data, strain FXJ7.203(T) represents a novel species of the genus Nonomuraea, for which the name Nonomuraea maritima sp. nov. is proposed, with strain FXJ7.203(T) ( = CGMCC 4.5681(T) = NBRC 106687(T)) as the type strain. PMID:21186288

  10. Complete Mitochondrial Genome of the Free-Living Earwig, Challia fletcheri (Dermaptera: Pygidicranidae) and Phylogeny of Polyneoptera

    PubMed Central

    Wan, Xinlong; Kim, Man Il; Kim, Min Jee; Kim, Iksoo

    2012-01-01

    The insect order Dermaptera, belonging to Polyneoptera, includes ?2,000 extant species, but no dermapteran mitochondrial genome has been sequenced. We sequenced the complete mitochondrial genome of the free-living earwig, Challia fletcheri, compared its genomic features to other available mitochondrial sequences from polyneopterous insects. In addition, the Dermaptera, together with the other known polyneopteran mitochondrial genome sequences (protein coding, ribosomal RNA, and transfer RNA genes), were employed to understand the phylogeny of Polyneoptera, one of the least resolved insect phylogenies, with emphasis on the placement of Dermaptera. The complete mitochondrial genome of C. fletcheri presents the following several unusual features: the longest size in insects is 20,456 bp; it harbors the largest tandem repeat units (TRU) among insects; it displays T- and G-skewness on the major strand and A- and C-skewness on the minor strand, which is a reversal of the general pattern found in most insect mitochondrial genomes, and it possesses a unique gene arrangement characterized by a series of gene translocations and/or inversions. The reversal pattern of skewness is explained in terms of inversion of replication origin. All phylogenetic analyses consistently placed Dermaptera as the sister to Plecoptera, leaving them as the most basal lineage of Polyneoptera or sister to Ephemeroptera, and placed Odonata consistently as the most basal lineage of the Pterygota. PMID:22879905

  11. EFFECTS OF SALINITY AND BOTTOM SUBSTRATE COMPOSITION ON THE GROWTH AND PROLIFERATION OF WIDGEONGRASS ( RUPPIA MARITIMA )

    EPA Science Inventory

    The preliminary work for these experiments has been conducted, and the data will be collected during the next 6-8 months. We will collect R. maritima samples from different environments along the Gulf Coast and compare the genetic diversity using the ITRS reg...

  12. IMPACTS OF SALINITY AND NUTRIENT STRESS TO RUPPIA MARITIMA AND ZOSTERA MARINA: A MESOCOSM EXPERIMENT

    EPA Science Inventory

    Healthy seagrass beds were once found throughout the shallow areas of Narragansett Bay, R.I. but have disappeared due to infilling, pollution and disease. In Greenwich Bay, a highly developed embayment within Narragansett Bay, Ruppia maritima has colonized an area on the norther...

  13. Nutritional and protein quality evaluation of thermally treated seeds of Canavalia maritima in the rat

    Microsoft Academic Search

    Sahadevan Seena; Kandikere R. Sridhar; Saraf R. Ramesh

    2005-01-01

    Roasted and pressure-cooked seeds of Canavalia maritima of coastal sand dunes of the southwest coast of India were assessed for proximate and mineral composition, amino acid and fatty acid profiles and antinutritional features. Growth and nitrogen balance studies were carried out to assess the nutritive value of thermally treated seeds in the rat. Proteins and energy values of Canavalia seeds

  14. Seasonal growth and reproduction of Ruppia maritima L. s.l. in Lake Pontchartrain, Louisiana, USA

    Microsoft Academic Search

    Hyun Jung Cho; Michael A. Poirrier

    2005-01-01

    Ruppia maritima L. s.l. is an important submerged aquatic plant in Lake Pontchartrain, a water quality impaired oligohaline estuary located north of New Orleans, Louisiana, USA. Efforts to restore Lake Pontchartrain are in progress, and a major restoration goal is the re-establishment of historic submerged macrophyte beds that have declined since first studied in 1953. This study was part of

  15. Physiological responses of Thalassia testudinum and Ruppia maritima to experimental salinity levels

    Microsoft Academic Search

    Donna M Berns

    2003-01-01

    Thalassia testudinum, a stenohaline seagrass species, and Ruppia maritima, a euryhaline submerged aquatic vegetation species, were subjected to the same seven salinity levels (0 - 60) in a controlled environment. The response variables examined were the occurrence of leaf discoloration, plant growth rates, photosynthetic characteristics of blade segments (Pmax, respiration, alpha, and Ik), and osmolality changes within the plant tissues.

  16. Interaction of leaves and roots of Ruppia maritima in the uptake of phosphate, ammonia and nitrate

    Microsoft Academic Search

    G. B. Thursby; M. M. Harlin

    1984-01-01

    Leafy shoots of Ruppia maritima were incubated in two-compartment chambers, with the roots in one compartment and the leaves in the other. Rates of phosphate and ammonia uptake were compared when roots and leaves were supplied with these nutrients separately and simultaneously. Uptake of phosphate and ammonia by leaves was reduced when these nutrients were supplied to the roots, but

  17. The use of seaweeds ( Ruppia maritima and Chaetomorpha linum) for lamb fattening during drought periods

    Microsoft Academic Search

    S. Rjiba Ktita; A. Chermiti; M. Mahouachi

    2010-01-01

    The objective of this experiment was to evaluate the nutritive value of two seaweeds (Ruppia maritima and Chaetomorpha linum) and the possibility of including them in a concentrate for partial replacement of common ingredients. Each species was incorporated in a concentrate at 20% level with barley and soybean meal. These two concentrates were compared to a control composed of 80%

  18. Developmental morphology of the androecium and gynoecium in Ruppia maritima L.: considerations for pollination

    Microsoft Academic Search

    Christian R. Lacroix; James R. Kemp

    1997-01-01

    Ruppia maritima, widgeon grass, is an aquatic angiosperm common in salt marshes. Although previous studies have covered general aspects of pollination and floral development, little information is available on the functional aspects and development of the androecium and gynoecium in relation to pollination. Using the techniques of scanning electron microscopy and thin sectioning, this study focuses on the functional morphology

  19. The Thermotoga maritima Phenotype Is Impacted by Syntrophic Interaction with Methanococcus jannaschii in Hyperthermophilic Coculture†

    PubMed Central

    Johnson, M. R.; Conners, S. B.; Montero, C. I.; Chou, C. J.; Shockley, K. R.; Kelly, R. M.

    2006-01-01

    Significant growth phase-dependent differences were noted in the transcriptome of the hyperthermophilic bacterium Thermotoga maritima when it was cocultured with the hyperthermophilic archaeon Methanococcus jannaschii. For the mid-log-to-early-stationary-phase transition of a T. maritima monoculture, 24 genes (1.3% of the genome) were differentially expressed twofold or more. In contrast, methanogenic coculture gave rise to 292 genes differentially expressed in T. maritima at this level (15.5% of the genome) for the same growth phase transition. Interspecies H2 transfer resulted in three- to fivefold-higher T. maritima cell densities than in the monoculture, with concomitant formation of exopolysaccharide (EPS)-based cell aggregates. Differential expression of specific sigma factors and genes related to the ppGpp-dependent stringent response suggests involvement in the transition into stationary phase and aggregate formation. Cell aggregation was growth phase dependent, such that it was most prominent during mid-log phase and decayed as cells entered stationary phase. The reduction in cell aggregation was coincidental with down-regulation of genes encoding EPS-forming glycosyltranferases and up-regulation of genes encoding ?-specific glycosyl hydrolases; the latter were presumably involved in hydrolysis of ?-linked EPS to release cells from aggregates. Detachment of aggregates may facilitate colonization of new locations in natural environments where T. maritima coexists with other organisms. Taken together, these results demonstrate that syntrophic interactions can impact the transcriptome of heterotrophs in methanogenic coculture, and this factor should be considered in examining the microbial ecology in anaerobic environments. PMID:16391122

  20. The aquatic vascular plant Ruppia maritima as an indicator organisms for contaminated sediments

    SciTech Connect

    Tagliabue, M.D.; Thursby, G.B. [Science Applications International Corporation, Narragansett, RI (United States); Walker, H.A. [Environmental Protection Agency, Narragansett, RI (United States); Johnston, R.K.

    1994-12-31

    An ongoing estuarine ecological risk assessment case study for the Portsmouth Naval Shipyard in the Great Bay (Kittery, ME, Portsmouth, NH) has been the catalyst for continued methods development with a rooted aquatic plant for a sediment toxicity test. A test using the aquatic vascular plant Ruppia maritima would be similar in it`s utility to the Algal (Champia parvula) Reproduction Test, an accepted, short term test (US EPA Short term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms). Laboratory studies were conducted to evaluate effects of lead, the primary site contaminant on R. maritima in the Great Bay. Morphology and life cycle of R. maritima are similar to that of the aquatic vascular plant Zostra marina which comprises up to 46% of the Great Bay habitat (Short 1992). R. maritima`s reduced size makes it a practical laboratory organism and Ruppia`s effects may offer useful insights into potential effects on Zostra or other aquatic vascular plants. Presently rooted vascular plants are not found in the site of concern (Clark Cove). This can be contributed to either of two factors; the physical parameters of the site, i.e., a depositional zone or the chemical parameters, i.e., metals contamination, specifically lead. Exposure of bedded and nonbedded plants occurred over a four day and ten day period using lead sulfate. Concentrations for bedded exposures were as follows, 0.3, 0.5, 0.8, 1.0 simultaneously extracted metal/acid volatile sulfide (SEM/AVS) molar ratios, and 0.1, 1.0, 10.0 and 100.0mg/l Pb for water only exposures. Some reduction in cumulative leaf growth was observed in the site samples as well as the spiked samples as compared to site controls. Results of this study and associated research which focuses on the further development of the Ruppia test methods will be presented.

  1. Production of reproductive shoots, vegetative shoots, and seeds in populations of Ruppia maritima L. from the Chesapeake Bay, Virginia

    Microsoft Academic Search

    Gene M. Silberhorn; Sharon Dewing; Pamela A. Mason

    1996-01-01

    The production of reproductive shoots, vegetative shoots, and seeds was characterized forRuppia maritima populations in the Virginia portion of Chesapeake Bay in 1988 and 1989. The study locations included two previously unvegetated\\u000a sites recently colonized byR. maritima in the Rappahannock River and an established site and an irregularly flooded marsh panne site, both in the York River. A\\u000a corer was

  2. Differential transcript regulation in Arabidopsis thaliana and the halotolerant Lobularia maritima indicates genes with potential function in plant salt adaptation

    Microsoft Academic Search

    Olga V. Popova; Oksoon Yang; Karl-Josef Dietz; Dortje Golldack

    2008-01-01

    Salt stress is an environmental factor that severely impairs plant growth and productivity. Salinity-induced transcript accumulation was monitored in the salt-sensitive Arabidopsis thaliana and the related salt-tolerant Lobularia maritima using cDNA-arrays with expressed sequence tags derived from a cDNA subtraction library of salt-stressed L. maritima. The expression profiles revealed differences of the steady state transcript regulation in A. thaliana and

  3. Structures of and Interactions Between Domains of Trigger Factor from Thermotoga maritima

    SciTech Connect

    Martinez-Hackert,E.; Hendrickson, W.

    2007-01-01

    Trigger factor (TF) is a eubacterial chaperone that associates with ribosomes at the peptide-exit tunnel and also occurs in excess free in the cytosol. TF is a three-domain protein that appears to exist in a dynamic equilibrium of oligomerization states and interdomain conformations. X-ray crystallography and chemical cross-linking were used to study the roles of the N- and C-terminal domains of Thermotoga maritima TF in TF oligomerization and chaperone activity. The structural conservation of both the N- and C-terminal TF domains was unambiguously established. The biochemical and crystallographic data reveal a tendency for these domains to partake in diverse and apparently nonspecific protein-protein interactions. It is found that the T. maritima and Escherichia coli TF surfaces lack evident exposed hydrophobic patches. Taken together, these data suggest that TF chaperones could interact with nascent proteins via hydrophilic surfaces.

  4. Outbreeding and Inbreeding in a Zinc-Lead Mine Population of Armeria maritima

    Microsoft Academic Search

    C. Lefèbvre

    1973-01-01

    ANTONOVICS1 and Lefèbvre2 have shown that self-fertility occurs in zinc-lead mine populations of normally incompatible species (Agrostis tenuis, Anthoxanthum odoratum, Armeria maritima). In Agrostis and Anthoxanthum1 this change to inbreeding is suggested to be an adaptation to reduce gene flow from plants growing adjacent to the mine that do not tolerate metals. In Armeria2 there is no surrounding non-tolerant population

  5. Evidence for lateral gene transfer between Archaea and Bacteria from genome sequence of Thermotoga maritima

    Microsoft Academic Search

    Karen E. Nelson; Rebecca A. Clayton; Steven R. Gill; Michelle L. Gwinn; Robert J. Dodson; Daniel H. Haft; Erin K. Hickey; Jeremy D. Peterson; William C. Nelson; Karen A. Ketchum; Lisa McDonald; Teresa R. Utterback; Joel A. Malek; Katja D. Linher; Mina M. Garrett; Ashley M. Stewart; Matthew D. Cotton; Matthew S. Pratt; Cheryl A. Phillips; Delwood Richardson; John Heidelberg; Granger G. Sutton; Robert D. Fleischmann; Jonathan A. Eisen; Owen White; Steven L. Salzberg; Hamilton O. Smith; J. Craig Venter; Claire M. Fraser

    1999-01-01

    The 1,860,725-base-pair genome of Thermotoga maritima MSB8 contains 1,877 predicted coding regions, 1,014 (54%) of which have functional assignments and 863 (46%) of which are of unknown function. Genome analysis reveals numerous pathways involved in degradation of sugars and plant polysaccharides, and 108 genes that have orthologues only in the genomes of other thermophilic Eubacteria and Archaea. Of the Eubacteria

  6. Native crystal structure of a nitric oxide-releasing lectin from the seeds of Canavalia maritima

    Microsoft Academic Search

    Carlos Alberto de Almeida Gadelha; Frederico Bruno Mendes Batista Moreno; Tatiane Santi-Gadelha; João Batista Cajazeiras; Bruno Anderson Matias da Rocha; Ana Maria Sampaio Assreuy; Mário Rogério Lima Mota; Nilson Vieira Pinto; Ana Vaneska Passos Meireles; Júlio César Borges; Beatriz Tupinamba Freitas; Fernanda Canduri; Emmanuel Prata Souza; Plínio Delatorre; David Neil Criddle; Walter Filgueira de Azevedo; Benildo Sousa Cavada

    2005-01-01

    Here, we report the crystallographic study of a lectin from Canavalia maritima seeds (ConM) and its relaxant activity on vascular smooth muscle, to provide new insights into the understanding of structure\\/function relationships of this class of proteins. ConM was crystallized and its structure determined by standard molecular replacement techniques. The amino acid residues, previously suggested incorrectly by manual sequencing, have

  7. Nutritional evaluation of tender pods of Canavalia maritima of coastal sand dunes

    Microsoft Academic Search

    Bhaskar Bhagya; Kandikere R. Sridhar; Sahadevan Seena; Chiu-Chung Young; Ananthapadmanabha B. Arun

    2010-01-01

    This study has been performed to evaluate the nutritional, antinutritional and protein qualities of tender pods of Canavalia maritima, the coastal sand dune wild legume of southwest India. The proximal features, minerals, amino acids, fatty acids, antinutritional\\u000a and protein qualities of fresh and pressure-cooked tender pods have been assessed. The crude protein was comparable to seeds\\u000a of many edible legumes.

  8. Physiological effects of short-term salinity changes on Ruppia maritima

    Microsoft Academic Search

    Lesley R. Murphy; Stephen T. Kinsey; Michael J. Durako

    2003-01-01

    Changes in Ruppia maritima L. leaf-tissue osmolality, compatible solute synthesis in leaf tissues, and maximum effective quantum yield in response to short-term changes in salinity were investigated. Plants cultured at 20‰ S were exposed to 0‰ S, 10‰ S (half-ambient), 20‰ S (ambient), and 40‰ S (twice-ambient) salinities. Total and non-vacuolar leaf osmolality for cultured plants significantly decreased (total: from

  9. Germination and algal-free laboratory culture of widgeon grass, Ruppia maritima

    Microsoft Academic Search

    Ulrich Seeliger; Cesar Cordazzo; Evamaria Wysk Koch

    1984-01-01

    A methodology for the isolation ofRuppia maritima L. into algal-free laboratory culture is described. Seeds were surface sterilized with 96% ethyl alcohol of pH 2, kept for\\u000a several months in cold storage at 7°C, and subsequently transferred to 25°C to induce germination. Basic culture conditions\\u000a are discussed and a vessel of easy maintenance and sterilization forRuppia culture in ground glass

  10. Development and characterization of microsatellite loci in Ruppia maritima L. (Ruppiaceae)

    Microsoft Academic Search

    Shuo Yu; Min-Yan Cui; Bin Liu; Xiao-Yan Wang; Xiao-Yong Chen

    2009-01-01

    Ruppia maritima L. (Ruppiaceae), a monoecious seagrass, is widely distributed in temperate and tropical regions. In this paper, we reported\\u000a ten polymorphic microsatellite loci developed for this species. The number of alleles per locus ranged from 2 to 7, and the\\u000a expected heterozygosity ranged from 0.240 to 0.701. No locus pair showed significant linkage disequilibrium. These polymorphic\\u000a SSR primers will

  11. Reactivation of methionine synthase from Thermotoga maritima (TM0268) requires the downstream gene product TM0269

    PubMed Central

    Huang, Sha; Romanchuk, Gail; Pattridge, Katherine; Lesley, Scott A.; Wilson, Ian A.; Matthews, Rowena G.; Ludwig, Martha

    2007-01-01

    The crystal structure of the Thermotoga maritima gene product TM0269, determined as part of genome-wide structural coverage of T. maritima by the Joint Center for Structural Genomics, revealed structural homology with the fourth module of the cobalamin-dependent methionine synthase (MetH) from Escherichia coli, despite the lack of significant sequence homology. The gene specifying TM0269 lies in close proximity to another gene, TM0268, which shows sequence homology with the first three modules of E. coli MetH. The fourth module of E. coli MetH is required for reductive remethylation of the cob(II)alamin form of the cofactor and binds the methyl donor for this reactivation, S-adenosylmethionine (AdoMet). Measurements of the rates of methionine formation in the presence and absence of TM0269 and AdoMet demonstrate that both TM0269 and AdoMet are required for reactivation of the inactive cob(II)alamin form of TM0268. These activity measurements confirm the structure-based assignment of the function of the TM0269 gene product. In the presence of TM0269, AdoMet, and reductants, the measured activity of T. maritima MetH is maximal near 80°C, where the specific activity of the purified protein is ?15% of that of E. coli methionine synthase (MetH) at 37°C. Comparisons of the structures and sequences of TM0269 and the reactivation domain of E. coli MetH suggest that AdoMet may be bound somewhat differently by the homologous proteins. However, the conformation of a hairpin that is critical for cobalamin binding in E. coli MetH, which constitutes an essential structural element, is retained in the T. maritima reactivation protein despite striking divergence of the sequences. PMID:17656578

  12. Reactivation of methionine synthase from Thermotoga maritima (TM0268) requires the downstream gene product TM0269.

    PubMed

    Huang, Sha; Romanchuk, Gail; Pattridge, Katherine; Lesley, Scott A; Wilson, Ian A; Matthews, Rowena G; Ludwig, Martha

    2007-08-01

    The crystal structure of the Thermotoga maritima gene product TM0269, determined as part of genome-wide structural coverage of T. maritima by the Joint Center for Structural Genomics, revealed structural homology with the fourth module of the cobalamin-dependent methionine synthase (MetH) from Escherichia coli, despite the lack of significant sequence homology. The gene specifying TM0269 lies in close proximity to another gene, TM0268, which shows sequence homology with the first three modules of E. coli MetH. The fourth module of E. coli MetH is required for reductive remethylation of the cob(II)alamin form of the cofactor and binds the methyl donor for this reactivation, S-adenosylmethionine (AdoMet). Measurements of the rates of methionine formation in the presence and absence of TM0269 and AdoMet demonstrate that both TM0269 and AdoMet are required for reactivation of the inactive cob(II)alamin form of TM0268. These activity measurements confirm the structure-based assignment of the function of the TM0269 gene product. In the presence of TM0269, AdoMet, and reductants, the measured activity of T. maritima MetH is maximal near 80 degrees C, where the specific activity of the purified protein is approximately 15% of that of E. coli methionine synthase (MetH) at 37 degrees C. Comparisons of the structures and sequences of TM0269 and the reactivation domain of E. coli MetH suggest that AdoMet may be bound somewhat differently by the homologous proteins. However, the conformation of a hairpin that is critical for cobalamin binding in E. coli MetH, which constitutes an essential structural element, is retained in the T. maritima reactivation protein despite striking divergence of the sequences. PMID:17656578

  13. JUNIPERUS MARITIMA, THE SEASIDE JUNIPER, A NEW SPECIES FROM PUGET SOUND, NORTH AMERICA

    Microsoft Academic Search

    Robert P. Adams

    Based on analyses of terpenoids, nrDNA and trnC-D SNPs as well as morphology and ecology, a new cryptic species, Juniperus maritima, from the Puget Sound region is recognized. The species, previously included in J. scopulorum, is characterized by having seed cones that mature in one year (14-16 months), seeds usually exserted from the cone, obtuse scale leaf tips, usually reniform

  14. Complexes of Thermotoga maritima S-adenosylmethionine decarboxylase provide insights into substrate specificity

    SciTech Connect

    Bale, Shridhar; Baba, Kavita; McCloskey, Diane E.; Pegg, Anthony E.; Ealick, Steven E.

    2010-06-25

    The polyamines putrescine, spermidine and spermine are ubiquitous aliphatic cations and are essential for cellular growth and differentiation. S-Adenosylmethionine decarboxylase (AdoMetDC) is a critical pyruvoyl-dependent enzyme in the polyamine-biosynthetic pathway. The crystal structures of AdoMetDC from humans and plants and of the AdoMetDC proenzyme from Thermotoga maritima have been obtained previously. Here, the crystal structures of activated T. maritima AdoMetDC (TmAdoMetDC) and of its complexes with S-adenosylmethionine methyl ester and 5{prime}-deoxy-5{prime}-dimethylthioadenosine are reported. The results demonstrate for the first time that TmAdoMetDC autoprocesses without the need for additional factors and that the enzyme contains two complete active sites, both of which use residues from both chains of the homodimer. The complexes provide insights into the substrate specificity and ligand binding of AdoMetDC in prokaryotes. The conservation of the ligand-binding mode and the active-site residues between human and T. maritima AdoMetDC provides insight into the evolution of AdoMetDC.

  15. The aquatic vascular plant Ruppia maritima as an indicator organism for contaminated sediments

    SciTech Connect

    Tagliabue, M.D.; Thursby, G.B.; Walker, H.A. [Environmental Protection Agency, Narragansett, RI (United States); Johnston, R.K.

    1995-12-31

    An ongoing estuarine ecological risk assessment case study for the Portsmouth Naval Shipyard in the Great Bay Estuary (New Hampshire, Maine) was the catalyst to continue development a rooted aquatic plant sediment toxicity test. Laboratory studies were conducted to evaluate effects of lead, the primary site contaminant on R. maritima in the Great Bay. Although the aquatic vascular plant Zostra marina comprises up to 46% of the Great Bay subtidal habitat, R. maritima`s much smaller size makes it a more practical laboratory organism. Effects on Ruppia may offer useful insights into potential effects on Zostra or other aquatic vascular plants. Presently rooted vascular plants are not found in Clark Cove located adjacent to a landfill disposal site on the shipyard. The absence of rooted vegetation can be contributed to, physical parameters of the site (turbidity, grain size, texture) or chemical parameters (heavy metal/Pb contamination, redox potential). Exposure of bedded and nonbedded plants occurred over a four day and ten day period using lead sulfate. Concentrations for bedded exposures were as follows, 0.3, 0.5, 0.8, 1.0 simultaneously extracted metal/acid volatile sulfide (SEM/AVS) molar ratios, and 0.1, 1.0, 10.0 and 100.0mg/l Pb for water only exposures. Reduction in cumulative leaf growth was observed for the Clark Cove sediments as well as the spiked sediments as compared to reference sediments.

  16. Ecophysiological response of Crambe maritima to airborne and soil-borne salinity

    PubMed Central

    de Vos, Arjen C.; Broekman, Rob; Groot, Maartje P.; Rozema, Jelte

    2010-01-01

    Background and Aims There is a need to evaluate the salt tolerance of plant species that can be cultivated as crops under saline conditions. Crambe maritima is a coastal plant, usually occurring on the driftline, with potential use as a vegetable crop. The aim of this experiment was to determine the growth response of Crambe maritima to various levels of airborne and soil-borne salinity and the ecophysiological mechanisms underlying these responses. Methods In the greenhouse, plants were exposed to salt spray (400 mm NaCl) as well as to various levels of root-zone salinity (RZS) of 0, 50, 100, 200 and 300 mm NaCl during 40 d. The salt tolerance of Crambe maritima was assessed by the relative growth rate (RGR) and its components. To study possible salinity effects on the tissue and cellular level, the leaf succulence, tissue Na+ concentrations, Na+ : K+ ratio, net K+/Na+ selectivity, N, P, K+, Ca2+, Mg2+, proline, soluble sugar concentrations, osmotic potential, total phenolics and antioxidant capacity were measured. Key Results Salt spray did not affect the RGR of Crambe maritima. However, leaf thickness and leaf succulence increased with salt spray. Root zone salinities up to 100 mm NaCl did not affect growth. However, at 200 mm NaCl RZS the RGR was reduced by 41 % compared with the control and by 56 % at 300 mm NaCl RZS. The reduced RGR with increasing RZS was largely due to the reduced specific leaf area, which was caused by increased leaf succulence as well as by increased leaf dry matter content. No changes in unit leaf rate were observed but increased RZS resulted in increased Na+ and proline concentrations, reduced K+, Ca2+ and Mg2+ concentrations, lower osmotic potential and increased antioxidant capacity. Proline concentrations of the leaves correlated strongly (r = 0·95) with RZS concentrations and not with plant growth. Conclusions Based on its growth response, Crambe maritima can be classified as a salt spray tolerant plant that is sensitive to root zone salinities exceeding 100 mm NaCl. PMID:20354071

  17. Structural Insight inot the low Affinity Between Thermotoga maritima CheA and CheB Compared to their Escherichia coli/Salmonella typhimurium Counterparts

    SciTech Connect

    S Park; B Crane

    2011-12-31

    CheA-mediated CheB phosphorylation and the subsequent CheB-mediated demethylation of the chemoreceptors are important steps required for the bacterial chemotactic adaptation response. Although Escherichia coli CheB has been reported to interact with CheA competitively against CheY, we have observed that Thermotoga maritima CheB has no detectable CheA-binding. By determining the CheY-like domain crystal structure of T. maritima CheB, and comparing against the T. maritima CheY and Salmonella typhimurium CheB structures, we propose that the two consecutive glutamates in the {beta}4/{alpha}4 loop of T. maritima CheB that is absent in T. maritima CheY and in E. coli/S. typhimurium CheB may be one factor contributing to the low CheA affinity.

  18. Scouting contaminated estuaries: heavy metal resistant and plant growth promoting rhizobacteria in the native metal rhizoaccumulator Spartina maritima.

    PubMed

    Mesa, J; Mateos-Naranjo, E; Caviedes, M A; Redondo-Gómez, S; Pajuelo, E; Rodríguez-Llorente, I D

    2015-01-15

    Spartina maritima is a native endangered heavy metal rhizoaccumulator cordgrass naturally growing in southwest coasts of Spain, where is used as a biotool to rehabilitate degraded salt marshes. Fifteen bacterial strains were isolated from the rhizosphere of S. maritima growing in the estuary of the Tinto River, one of the most polluted areas in the world. A high proportion of bacteria were resistant towards several heavy metals. They also exhibited multiple plant growth promoting (PGP) properties, in the absence and the presence of Cu. Bacillus methylotrophicus SMT38, Bacillusaryabhattai SMT48, B. aryabhattai SMT50 and Bacilluslicheniformis SMT51 were selected as the best performing strains. In a gnobiotic assay, inoculation of Medicago sativa seeds with the selected isolates induced higher root elongation. The inoculation of S. maritima with these indigenous metal-resistant PGP rhizobacteria could be an efficient method to increase plant adaptation and growth in contaminated estuaries during restoration programs. PMID:25467875

  19. The first myriapod genome sequence reveals conservative arthropod gene content and genome organisation in the centipede Strigamia maritima.

    PubMed

    Chipman, Ariel D; Ferrier, David E K; Brena, Carlo; Qu, Jiaxin; Hughes, Daniel S T; Schröder, Reinhard; Torres-Oliva, Montserrat; Znassi, Nadia; Jiang, Huaiyang; Almeida, Francisca C; Alonso, Claudio R; Apostolou, Zivkos; Aqrawi, Peshtewani; Arthur, Wallace; Barna, Jennifer C J; Blankenburg, Kerstin P; Brites, Daniela; Capella-Gutiérrez, Salvador; Coyle, Marcus; Dearden, Peter K; Du Pasquier, Louis; Duncan, Elizabeth J; Ebert, Dieter; Eibner, Cornelius; Erikson, Galina; Evans, Peter D; Extavour, Cassandra G; Francisco, Liezl; Gabaldón, Toni; Gillis, William J; Goodwin-Horn, Elizabeth A; Green, Jack E; Griffiths-Jones, Sam; Grimmelikhuijzen, Cornelis J P; Gubbala, Sai; Guigó, Roderic; Han, Yi; Hauser, Frank; Havlak, Paul; Hayden, Luke; Helbing, Sophie; Holder, Michael; Hui, Jerome H L; Hunn, Julia P; Hunnekuhl, Vera S; Jackson, LaRonda; Javaid, Mehwish; Jhangiani, Shalini N; Jiggins, Francis M; Jones, Tamsin E; Kaiser, Tobias S; Kalra, Divya; Kenny, Nathan J; Korchina, Viktoriya; Kovar, Christie L; Kraus, F Bernhard; Lapraz, François; Lee, Sandra L; Lv, Jie; Mandapat, Christigale; Manning, Gerard; Mariotti, Marco; Mata, Robert; Mathew, Tittu; Neumann, Tobias; Newsham, Irene; Ngo, Dinh N; Ninova, Maria; Okwuonu, Geoffrey; Ongeri, Fiona; Palmer, William J; Patil, Shobha; Patraquim, Pedro; Pham, Christopher; Pu, Ling-Ling; Putman, Nicholas H; Rabouille, Catherine; Ramos, Olivia Mendivil; Rhodes, Adelaide C; Robertson, Helen E; Robertson, Hugh M; Ronshaugen, Matthew; Rozas, Julio; Saada, Nehad; Sánchez-Gracia, Alejandro; Scherer, Steven E; Schurko, Andrew M; Siggens, Kenneth W; Simmons, DeNard; Stief, Anna; Stolle, Eckart; Telford, Maximilian J; Tessmar-Raible, Kristin; Thornton, Rebecca; van der Zee, Maurijn; von Haeseler, Arndt; Williams, James M; Willis, Judith H; Wu, Yuanqing; Zou, Xiaoyan; Lawson, Daniel; Muzny, Donna M; Worley, Kim C; Gibbs, Richard A; Akam, Michael; Richards, Stephen

    2014-11-01

    Myriapods (e.g., centipedes and millipedes) display a simple homonomous body plan relative to other arthropods. All members of the class are terrestrial, but they attained terrestriality independently of insects. Myriapoda is the only arthropod class not represented by a sequenced genome. We present an analysis of the genome of the centipede Strigamia maritima. It retains a compact genome that has undergone less gene loss and shuffling than previously sequenced arthropods, and many orthologues of genes conserved from the bilaterian ancestor that have been lost in insects. Our analysis locates many genes in conserved macro-synteny contexts, and many small-scale examples of gene clustering. We describe several examples where S. maritima shows different solutions from insects to similar problems. The insect olfactory receptor gene family is absent from S. maritima, and olfaction in air is likely effected by expansion of other receptor gene families. For some genes S. maritima has evolved paralogues to generate coding sequence diversity, where insects use alternate splicing. This is most striking for the Dscam gene, which in Drosophila generates more than 100,000 alternate splice forms, but in S. maritima is encoded by over 100 paralogues. We see an intriguing linkage between the absence of any known photosensory proteins in a blind organism and the additional absence of canonical circadian clock genes. The phylogenetic position of myriapods allows us to identify where in arthropod phylogeny several particular molecular mechanisms and traits emerged. For example, we conclude that juvenile hormone signalling evolved with the emergence of the exoskeleton in the arthropods and that RR-1 containing cuticle proteins evolved in the lineage leading to Mandibulata. We also identify when various gene expansions and losses occurred. The genome of S. maritima offers us a unique glimpse into the ancestral arthropod genome, while also displaying many adaptations to its specific life history. PMID:25423365

  20. Biosynthesis of cyanogenic glucosides in Triglochin maritima and the involvement of cytochrome P450 enzymes.

    PubMed

    Nielsen, J S; Moller, B L

    1999-08-01

    The biosynthesis of the two cyanogenic glucosides, taxiphyllin and triglochinin, in Triglochin maritima (seaside arrow grass) has been studied using undialyzed microsomal preparations from flowers and fruits. Tyrosine was converted to p-hydroxymandelonitrile with V(max) and K(m) values of 36 nmol mg(-1) g(-1) fresh weight and 0.14 mM, respectively. p-Hydroxyphenylacetaldoxime and p-hydroxyphenylacetonitrile accumulated as intermediates in the reaction mixtures. Using radiolabeled tyrosine as substrate, the radiolabel was easily trapped in p-hydroxyphenylacetaldoxime and p-hydroxyphenylacetonitrile when these were added as unlabeled compounds. p-Hydroxyphenylacetaldoxime was the only product obtained using microsomes prepared from green leaves or dialyzed microsomes prepared from flowers and fruits. These data contrast earlier reports (Hösel and Nahrstedt, Arch. Biochem. Biophys. 203, 753-757, 1980; and Cutler et al., J. Biol. Chem. 256, 4253-4258, 1981) where p-hydroxyphenylacetaldoxime was found not to accumulate. All steps in the conversion of tyrosine to p-hydroxymandelonitrile were found to be catalyzed by cytochrome P450 enzymes as documented by photoreversible carbon monoxide inhibition, inhibition by antibodies toward NADPH-cytochrome P450 oxidoreductase, and by cytochrome P450 inhibitors. We hypothesize that cyanogenic glucoside synthesis in T. maritima is catalyzed by multifunctional cytochrome P450 enzymes similar to CYP79A1 and CYP71E1 in Sorghum bicolor except that the homolog to CYP71E1 in T. maritima exhibits a less tight binding of p-hydroxyphenylacetonitrile, thus permitting the release of this intermediate and its conversion into triglochinin. PMID:10415119

  1. Triacylated cyanidin 3-(3 X-glucosylsambubioside)-5-glucosides from the flowers of Malcolmia maritima

    Microsoft Academic Search

    Fumi Tatsuzawa; Norio Saito; Kenjiro Toki; Koichi Shinoda; Atsushi Shigihara; Toshio Honda

    2008-01-01

    Three acylated cyanidin 3-(3X-glucosylsambubioside)-5-glucosides (1–3) and one non-acylated cyanidin 3-(3X-glucosylsambubioside)-5-glucoside (4) were isolated from the purple-violet or violet flowers and purple stems of Malcolmia maritima (L.) R. Br (the Cruciferae), and their structures were determined by chemical and spectroscopic methods. In the flowers of this plant, pigment 1 was determined to be cyanidin 3-O-[2-O-(2-O-(trans-sinapoyl)-3-O-(?-d-glucopyranosyl)-?-d-xylopyranosyl)-6-O-(trans-p-coumaroyl)-?-d-glucopyranoside]-5-O-[6-O-(malonyl)-(?-d-glucopyranoside) as a major pigment, and a

  2. Comparative characterization of deletion derivatives of the modular xylanase XynA of Thermotoga maritima

    Microsoft Academic Search

    Jörg Kleine; Wolfgang Liebl

    2006-01-01

    The modular Xylanase XynA from Thermotoga maritima consists of five domains (A1-A2-B-C1-C2). Two similar N-terminal domains (A1-A2-) are family 22 carbohydrate-binding modules (CBMs), followed by the catalytic domain (-B-) belonging to glycoside hydrolase family 10, and the C-terminal domains (-C1-C2), which are members of family 9 of CBMs. The gradual deletion of the non-catalytic domains resulted in deletion derivatives (XynA?C;

  3. Galacto-oligosaccharide production by a thermostable recombinant ?-galactosidase from Thermotoga maritima

    Microsoft Academic Search

    Eun-Su Ji; Nyun-Ho Park; Deok-Kun Oh

    2005-01-01

    Summary A ?-galactosidase from Thermotoga maritima produced galacto-oligosaccharides (GOS) from lactose by transgalactosylation when expressed in Escherichia coli. The enzyme activity for GOS production was maximal at pH 6.0 and 90 °C. In thermal stability experiments, the enzyme followed first-order kinetics of pH and thermal inactivation, and half-lives at pH 5.0, pH 8.0, 80 °C, and 95 °C were 27 h, 82 h, 41 h, and

  4. Acylated Pelargonidin 3-sambubioside-5-glucosides from the Red-purple Flowers of Lobularia maritima

    Microsoft Academic Search

    Fumi Tatsuzawa; Rie Usuki; Kenjiro Toki; Norio Saito; Koichi Shinoda; Atsushi Shigihara; Toshio Honda

    2010-01-01

    Six acylated pelargonidin 3-O-sambubioside-5-O-glucosides were isolated from red-purple flowers of Lobularia maritima (L.) Desv. 'Easter Bonnet Deep Rose'. These pigments were determined by chemical and spectroscopic methods to be pelargonidin 3-O-(2-O-(2-O-(acyl-II)-?-xylopyranosyl)-6-O-(acyl-I)-?-glucopyranoside)-5-O-?- glucopyranoside, in which the acyl-I group was replaced by 4-O-glucosyl-p-coumaric acid, p-coumaric acid or ferulic acid, and acyl-II by caffeic acid or ferulic acid, respectively. In comparison with the

  5. Anthemis maritima L. in different coastal habitats: A tool to explore plant plasticity

    NASA Astrophysics Data System (ADS)

    Spanò, Carmelina; Balestri, Mirko; Bottega, Stefania; Grilli, Isa; Forino, Laura Maria Costantina; Ciccarelli, Daniela

    2013-09-01

    Anthemis maritima, a plant which has the ability to colonise different stressful coastal environments, sand dunes and rocky cliff ecosystems, exhibits a high degree of leaf trait plasticity. The key parameters are the regulation of stomatal density and size, the succulence index and the specific antioxidant response. With the aim to explore plant plasticity, we analysed various morphological and physiological traits of the leaves of A. maritima populations dwelling in three different coastal areas of Italy. The highest values of stomatal density, leaf thickness, and succulence index were found in plants living in a sub-arid climate, on rocky cliffs, with the highest soil pH and salinity. Although this population exhibited the highest concentration of oxygen reactive species (hydrogen peroxide), it also had the lowest value of lipid peroxidation, an indicator of oxidative stress. Ascorbate was the main protective molecule in this population, while phenols appeared to carry out this role in plants living on soils with the lowest salinity and highest annual rainfall.

  6. Purification, crystallization and preliminary crystallographic analysis of a Thermostable Endonuclease IV from Thermotoga maritima

    SciTech Connect

    Coates, Leighton [ORNL; Tomanicek, Stephen J [ORNL; Hughes, Ronny C [ORNL; NG, Joseph D [ORNL; Demarse, Neil A [ORNL

    2009-01-01

    The DNA repair enzyme Endonuclease IV from the thermophilic bacterium Thermotoga Maritima MSB8 (reference sequence: NC_000853) has been expressed in Escherichia coli and crystallized for X ray analysis. Thermotoga maritima Endonuclease IV is a 287 amino acid protein with 32% sequence identity to the Escherichia coli Endonuclease IV. The protein was purified to homogeneity and was crystallized using the sitting drop vapor diffusion method. The protein crystallized in the space group P61, with a composition of one biological molecule in the asymmetric unit corresponding to a Mathew s coefficient of 2.39 and a 47% solvent fraction. The unit cell parameters for the crystals are a = 123.23 , b = 123.23 , c = 35.34 , = = 90 , = 120 . Microseeding and further optimization yielded crystals with an X ray diffraction limit of 2.4 . A single 70 data set was collected and processed resulting in an overall Rmerge and completeness of 9.5% and 99.3% respectively.

  7. Molecular genetic tagging of Beta vulgaris ssp. maritima-derived resistance to the sugar beet cyst nematode, Heterodera schachtii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance in commercial sugar beet hybrids to the sugar beet cyst nematode (SBCN) principally has been based on the Hs1 gene from the wild beet Beta procumbens, yet incorporation of this resistance has been detrimental to crop yield in nematode-free fields. Accessions of B. vulgaris ssp maritima w...

  8. Permeability and reactivity of Thermotoga maritima in latex bimodal blend coatings at 80°C: a model high temperature biocatalytic coating

    Microsoft Academic Search

    Olav K. Lyngberg; Chris Solheid; Salim Charaniya; Yue Ma; Venkata Thiagarajan; L. E. Scriven; Michael C. Flickinger

    2005-01-01

    Thermostable polymers cast as thin, porous coatings or membranes may be useful for concentrating and stabilizing hyperthermophilic microorganisms as biocatalysts. Hydrogel matricies can be unstable above 65°C. Therefore a 55-µm thick, two layer (cell coat + polymer top coat) bimodal, adhesive latex coating of partially coalesced polystyrene particles was investigated at 80°C using Thermotoga maritima as a model hyperthermophile. Coating

  9. Antioxidant activity and biologic properties of a procyanidin-rich extract from pine ( pinus maritima) bark, pycnogenol

    Microsoft Academic Search

    L Packer; G Rimbach; F Virgili

    1999-01-01

    There is growing interest in the biologic activities of plant extracts such as that obtained from the bark of the French maritime pine Pinus maritima, Pycnogenol. Pycnogenol (PYC) is a standardized extract composed of a mixture of flavonoids, mainly procyandins and phenolic acids. Studies indicate that PYC components are highly bioavailable. Uniquely PYC displays greater biologic effects as a mixture

  10. The flowering pattern of the perennial herb Lobularia maritima : an unusual case in the Mediterranean basin

    Microsoft Academic Search

    F. Xavier Picó; Javier Retana

    2001-01-01

    In plant communities of the Mediterranean Basin most plant species reach their blooming peak in spring and have characteristically short flowering periods of two-three months. The perennial herb Lobularia maritima represents an exception to these characteristics, because it flowers for almost 10 months, and has its flowering peak in autumn. In this five-year study, we describe the flowering pattern of

  11. Characterization of a thermostable family 10 endo-xylanase (XynB) from Thermotoga maritima that cleaves p-nitrophenyl-?- d-xyloside

    Microsoft Academic Search

    Jiang Zhengqiang; Atsushi Kobayashi; Mohammad Mainul Ahsan; Li Lite; Motomitsu Kitaoka; Kiyoshi Hayashi

    2001-01-01

    Thermotoga maritima MSB8 possesses two xylanase genes, xynA and xynB. The xynB gene was isolated from the genomic DNA of T. maritima, cloned, and expressed in Escherichia coli. XynB was purified to homogeneity by heat treatment, affinity chromatography and ion-exchange column chromatography. The purified enzyme produced a single band upon SDS-PAGE corresponding to a molecular mass of 42 kDa. At

  12. Crystallization and preliminary X-ray diffraction analysis of a lectin from Canavalia maritima seeds.

    PubMed

    Gadelha, Carlos Alberto de Almeida; Moreno, Frederico Bruno Mendes Batista; Santi-Gadelha, Tatiane; Cajazeiras, João Batista; Rocha, Bruno Anderson M da; Rustiguel, Joane Kathelen Rodrigues; Freitas, Beatriz Tupinamba; Canduri, Fernanda; Delatorre, Plínio; Azevedo, Walter Filgueira de; Cavada, Benildo S

    2005-01-01

    A lectin from Canavalia maritima seeds (ConM) was purified and submitted to crystallization experiments. The best crystals were obtained using the vapour-diffusion method at a constant temperature of 293 K and grew in 7 d. A complete structural data set was collected to 2.1 A resolution using a synchrotron-radiation source. The ConM crystal belongs to the orthorhombic space group P2(1)2(1)2, with unit-cell parameters a = 67.15, b = 70.90, c = 97.37 A. A molecular-replacement search found a solution with a correlation coefficient of 69.2% and an R factor of 42.5%. Crystallographic refinement is under way. PMID:16508099

  13. Crystallization and preliminary X-ray diffraction analysis of a lectin from Canavalia maritima seeds

    PubMed Central

    de Almeida Gadelha, Carlos Alberto; Moreno, Frederico Bruno Mendes Batista; Santi-Gadelha, Tatiane; Cajazeiras, João Batista; da Rocha, Bruno Anderson M.; Rustiguel, Joane Kathelen Rodrigues; Freitas, Beatriz Tupinamba; Canduri, Fernanda; Delatorre, Plínio; de Azevedo, Walter Filgueira; Cavada, Benildo S.

    2005-01-01

    A lectin from Canavalia maritima seeds (ConM) was purified and submitted to crystallization experiments. The best crystals were obtained using the vapour-diffusion method at a constant temperature of 293?K and grew in 7?d. A complete structural data set was collected to 2.1?Å resolution using a synchrotron-radiation source. The ConM crystal belongs to the orthorhombic space group P21212, with unit-cell parameters a = 67.15, b = 70.90, c = 97.37?Å. A molecular-replacement search found a solution with a correlation coefficient of 69.2% and an R factor of 42.5%. Crystallographic refinement is under way. PMID:16508099

  14. Uptake of selenium by Ruppia maritima from microcosm sediments under controlled redox conditions

    SciTech Connect

    Bailey, F.C.; Dunlap, J.L.; Klaine, S.J. [Clemson Univ., Pendleton, SC (United States). Dept. of Environmental Toxicology/TIWET

    1994-12-31

    Redox potential plays a vital role in the speciation, bioavailability, and toxicity of metals and metalloids in sediments. The authors previously reported the development of a unique system which drives and maintains the redox of microcosm sediments with electrical current. The effectiveness of the redox control system has been validated by dosing microcosm sediments with acid volatile sulfide (AVS) and exerting either reducing conditions to maintain AVS or oxidizing conditions to induce a significant loss of AVS. Uptake of selenite, selenite and seleno-methionine from microcosm sediments by the aquatic plant Ruppia maritima was determined under redox conditions appropriate for each selenium species. Selenate uptake was determined for oxidizing and neutral conditions, while selenite and seleno-methionine uptake was determined for neutral and reducing redox potentials.

  15. High phenotypic plasticity of Suaeda maritima observed under hypoxic conditions in relation to its physiological basis

    PubMed Central

    Wetson, Anne M.; Zörb, Christian; John, Elizabeth A.; Flowers, Timothy J.

    2012-01-01

    Background and Aims Phenotypic plasticity, the potential of specific traits of a genotype to respond to different environmental conditions, is an important adaptive mechanism for minimizing potentially adverse effects of environmental fluctuations in space and time. Suaeda maritima shows morphologically different forms on high and low areas of the same salt marsh. Our aims were to examine whether these phenotypic differences occurred as a result of plastic responses to the environment. Soil redox state, indicative of oxygen supply, was examined as a factor causing the observed morphological and physiological differences. Methods Reciprocal transplantation of seedlings was carried out between high and low marsh sites on a salt marsh and in simulated tidal-flow tanks in a glasshouse. Plants from the same seed source were grown in aerated or hypoxic solution, and roots were assayed for lactate dehydrogenase (LDH) and alcohol dehydrogenase, and changes in their proteome. Key Results Transplanted (away) seedlings and those that remained in their home position developed the morphology characteristic of the home or away site. Shoot Na+, Cl? and K+ concentrations were significantly different in plants in the high and low marsh sites, but with no significant difference between home and away plants at each site. High LDH activity in roots of plants grown in aeration and in hypoxia indicated pre-adaptation to fluctuating root aeration and could be a factor in the phenotypic plasticity and growth of S. maritima over the full tidal range of the salt marsh environment. Twenty-six proteins were upregulated under hypoxic conditions. Conclusions Plasticity of morphological traits for growth form at extremes of the soil oxygenation spectrum of the tidal salt marsh did not correlate with the lack of physiological plasticity in the constitutively high LDH found in the roots. PMID:22316572

  16. Proteomic and metabolic profiles of Cakile maritima Scop. Sea Rocket grown in the presence of cadmium.

    PubMed

    Taamalli, Manel; D'Alessandro, Angelo; Marrocco, Cristina; Gevi, Federica; Timperio, Anna Maria; Zolla, Lello

    2015-04-01

    Recent physiological reports have documented how Cakile maritima Scop. Sea Rocket could accumulate high doses of Cd without altering its physiological parameters. In the present study, we performed an integrated proteomics (2DE) and metabolomics (HPLC-MS) investigation to determine the molecular mechanisms underlying cadmium (Cd) tolerance of this halophyte. Peculiar features were observed: (i) up-regulation of thiol compound anabolism, including glutathione and phytochelatin homeostasis, which allows an intracellular chelation of Cd and its compartmentalization into vacuole by a significant up-regulation of vacuolar transporters; (ii) up-regulation of the PPP and Calvin cycle (both at the enzyme and metabolite level), which utterly promoted the maintenance of NADPH/NADP(+) homeostasis, other than the accumulation of triose-phosphates (serving as anabolic intermediates for triacylglycerol biosynthesis) and the glyoxylate precursor phosphoglycolate, to promote photorespiration and consequently CO2 release. An up-regulation of carbonic anhydrase was also observed. This halophyte is also correlated with a highly efficient antioxidant system, especially a high up-regulation of SOD1, resulting more efficient in coping with heavy metals stress than common plants. Interestingly, exposure to high Cd concentrations partly affected photosystem integrity and metabolic activity, through the up-regulation of enzymes from the Calvin cycle and glutathione-ascorbate homeostasis and PAP3 which stabilizes thylakoid membrane structures. In addition, up-regulation of Peptidyl-prolyl isomerase CYP38 increases stability and biogenesis of PSII. Finally, metabolomics results confirmed proteomics and previous physiological evidence, also suggesting that osmoprotectants, betaine and proline, together with plant hormones, methyl jasmonate and salicylic acid, might be involved in mediating responses to Cd-induced stress. Taken together, these peculiar features confirm that Cakile maritima Scop. Sea Rocket seemed to be naturally equipped to withstand even high doses of Cd pollution. PMID:25639878

  17. Adaptive Evolution of Thermotoga maritima Reveals Plasticity of the ABC Transporter Network.

    PubMed

    Latif, Haythem; Sahin, Merve; Tarasova, Janna; Tarasova, Yekaterina; Portnoy, Vasiliy A; Nogales, Juan; Zengler, Karsten

    2015-08-15

    Thermotoga maritima is a hyperthermophilic anaerobe that utilizes a vast network of ABC transporters to efficiently metabolize a variety of carbon sources to produce hydrogen. For unknown reasons, this organism does not metabolize glucose as readily as it does glucose di- and polysaccharides. The leading hypothesis implicates the thermolability of glucose at the physiological temperatures at which T. maritima lives. After a 25-day laboratory evolution, phenotypes were observed with growth rates up to 1.4 times higher than and glucose utilization rates exceeding 50% those of the wild type. Genome resequencing revealed mutations in evolved cultures related to glucose-responsive ABC transporters. The native glucose ABC transporter, GluEFK, has more abundant transcripts either as a result of gene duplication-amplification or through mutations to the operator sequence regulating this operon. Conversely, BglEFGKL, a transporter of beta-glucosides, is substantially downregulated due to a nonsense mutation to the solute binding protein or due to a deletion of the upstream promoter. Analysis of the ABC2 uptake porter families for carbohydrate and peptide transport revealed that the solute binding protein, often among the transcripts detected at the highest levels, is predominantly downregulated in the evolved cultures, while the membrane-spanning domain and nucleotide binding components are less varied. Similar trends were observed in evolved strains grown on glycerol, a substrate that is not dependent on ABC transporters. Therefore, improved growth on glucose is achieved through mutations favoring GluEFK expression over BglEFGKL, and in lieu of carbon catabolite repression, the ABC transporter network is modulated to achieve improved growth fitness. PMID:26048924

  18. Interacting infl uence of cold stratifi cation treatment and osmotic potential on seed germination of Triglochin maritima L

    Microsoft Academic Search

    Gederts Ievinsh

    2007-01-01

    Th e eff ect of cold stratifi cation treatment and isoosmotic NaCl and polyethyleneglycol (PEG) concentrations on germination of Triglochin maritima seeds was assessed. Th e highest (400 mM) NaCl concentration caused a signifi cant decrease in germination percentage and no germination was observed at the two highest (64 and 128 mM) PEG concentrations. Th e large diff erence in

  19. Characterization of exceptionally thermostable single-stranded DNA-binding proteins from Thermotoga maritima and Thermotoga neapolitana

    Microsoft Academic Search

    Marcin Olszewski; Anna Grot; Marek Wojciechowski; Marta Nowak; Ma?gorzata Mickiewicz; Józef Kur

    2010-01-01

    BACKGROUND: In recent years, there has been an increasing interest in SSBs because they find numerous applications in diverse molecular biology and analytical methods. RESULTS: We report the characterization of single-stranded DNA binding proteins (SSBs) from the thermophilic bacteria Thermotoga maritima (TmaSSB) and Thermotoga neapolitana (TneSSB). They are the smallest known bacterial SSB proteins, consisting of 141 and 142 amino

  20. Nutritional and biological qualities of the ripened beans of Canavalia maritima from the coastal sand dunes of India

    Microsoft Academic Search

    B. Bhagya; K. R. Sridhar; N. S. Raviraja; C.-C. Young; A. B. Arun

    2009-01-01

    Raw and pressure-cooked ripened beans of Canavalia maritima were assessed for nutritional quality. The beans possess high protein, carbohydrate, fiber and energy contents. Potassium, magnesium, zinc and manganese of the raw and cooked beans meet NRC\\/NAS recommended pattern for infants. The essential amino acids (threonine, valine, isoleucine, leucine, tyrosine\\/phenylalanine and lysine) in raw and cooked ripened beans fulfill the FAO\\/WHO\\/UNU

  1. Phytoplankton production and seasonal biomass variation of seagrass, Ruppia maritima L., in a tropical Mexican lagoon with an ephemeral inlet

    Microsoft Academic Search

    Francisco J. Flores-Verdugo; John W. Day; Laurence Mee; Raquel Briseño-Dueñas

    1988-01-01

    Plankton metabolism andRuppia maritima biomass were measured seasonally during 1982–83 in El Verde Lagoon, a small coastal lagoon with an ephemeral inlet on the\\u000a Pacific Coast of Mexico. Total net aquatic primary production was 521 g C m?2 y?1. The water column was slightly heterotrophic, with an annual P\\/R ratio of 0.89. Our analysis indicates that tropical and\\u000a subtropical coastal

  2. In vitro studies of the submerged angiosperm Ruppia maritima : Auxin and cytokinin effects on plant growth and development

    Microsoft Academic Search

    E. W. Koch; M. J. Durako

    1991-01-01

    Axenic tissue cultures ofRuppia maritima L. were established and propagated clonally in vitro from terminal rhizome segments collected from Tampa Bay, Florida, USA. Cultures were maintained in a base medium consisting of synthetic seawater supplemented with half-strength Murashige and Skoog salts and 1% sucrose at pH 5.6. The effects of five cytokins [6-furfurylaminopurine (kinetin), 6-benzylaminopurine (BAP), 2-isopentyladenine (2iP), 6-(4-hydroxy-3-methyl-but-2-enylamino) purine

  3. Effectiveness of ants as pollinators of Lobularia maritima : effects on main sequential fitness components of the host plant

    Microsoft Academic Search

    José M. Gómez

    2000-01-01

    The effectiveness of ants as pollinators of Lobularia maritima (Cruciferae) was experimentally analyzed by assessing (1) their quantitative importance at flowers; (2) their effect on host\\u000a plant seed production; (3) their effect on the performance of host plant progeny, estimated as seed germination, seedling\\u000a emergence, seedling survival to flowering, and (4) the overall effect of ants on a cumulative, more

  4. Differential transcript regulation in Arabidopsis thaliana and the halotolerant Lobularia maritima indicates genes with potential function in plant salt adaptation.

    PubMed

    Popova, Olga V; Yang, Oksoon; Dietz, Karl-Josef; Golldack, Dortje

    2008-11-01

    Salt stress is an environmental factor that severely impairs plant growth and productivity. Salinity-induced transcript accumulation was monitored in the salt-sensitive Arabidopsis thaliana and the related salt-tolerant Lobularia maritima using cDNA-arrays with expressed sequence tags derived from a cDNA subtraction library of salt-stressed L. maritima. The expression profiles revealed differences of the steady state transcript regulation in A. thaliana and L. maritima in response to salt stress. The differentially expressed transcripts include those involved in the control of gene expression as a transcription factor II homologue as well as signal transduction elements such as a serine/threonine protein kinase, a SNF1-related protein kinase AKIN10 homologue, and protein phosphatase 2C. Other ESTs with differential regulation patterns included transcripts encoding proteins with function in general stress responses and defense and included a peroxidase, dehydrins, enzymes of lipid and nitrogen metabolism, and functionally unclassified proteins. In a more detailed analysis the basic leucine zipper transcription factor AtbZIP24 showed differential transcript abundance in A. thaliana and L. maritima in response to salt stress. Transgenic AtbZIP24-RNAi lines showed improved growth and development under salt stress that was correlated with changed Cl(-) accumulation. The data indicate that AtbZIP24 functions as a transcriptional repressor in salt-stressed A. thaliana that negatively regulates growth and development under salinity in context of controlling Cl(-) homeostasis. Monitoring the differential and tissue specific global regulation of gene expression during adaptation to salinity in salt-sensitive and halotolerant plants is a promising and powerful approach to identify novel elements of plant salt stress adaptation. PMID:18703123

  5. Ecology of beach wrack in northern New England with special reference to Orchestia platensis*1

    NASA Astrophysics Data System (ADS)

    Behbehani, Manaf I.; Croker, Robert A.

    1982-12-01

    The northern New England beach wrack community with special reference to the cosmopolitan amphipod crustacean, Orchestia platensis, was examined at estuarine and open coastal habitats. Beach wrack was dominated by the plant genera Ascophyllum, Zostera, Spartina and Chondrus, and was most abundant during spring and late summer. Animal community numbers, biomass and frequency in fresh to moderately decomposed wrack were dominated by O. platensis throughout the year at all habitats; oligochaetes and Collembola were also important. The abundance of O. platensis showed high spatial and temporal variability, with low abundance generally associated with decreased amounts of wrack during colder months. An exception was the winter presence of the species at one estuarine habitat, in patchy aggregations within gravel-cobble refuges. The abundance of O. platensis averaged 1280 (0.04 m 2) -1, with a maximum of 7040 (0.04 m 2) -1. The life cycle of O. platensis is bivoltine, with summer-hatched young reaching maturity within 1 month. Laboratory studies indicate females with up to 4 broods (30 days) -1, averaging 18 eggs brood -1. Orchestia platensis is omnivorous, eating fresh plant tissue, live oligochaetes, Limulus eggs and diatom 'fuzz'. The rate of laboratory consumption of algae and Zostera was 0.05 mg plant mg -1 wet body weight day -1. Presumptive predators of O. platensis are juvenile green crab, Carcinus maenus, and the earwig. Anisolabis maritima. The mobility, aggregation and aggressiveness of O. platensis assist the species in establishing and maintaining populations in the rigorous wrack habitat. The general competitive superiority of O. platensis over its congener, O. gammarella, and the co-occurrence of these species on both eastern and western Atlantic shores is discussed.

  6. Expression, purification, and characterization of Thermotoga maritima membrane proteins for structure determination

    PubMed Central

    Columbus, Linda; Lipfert, Jan; Klock, Heath; Millett, Ian; Doniach, Sebastian; Lesley, Scott A.

    2006-01-01

    Structural studies of integral membrane proteins typically rely upon detergent micelles as faithful mimics of the native lipid bilayer. Therefore, membrane protein structure determination would be greatly facilitated by biophysical techniques that are capable of evaluating and assessing the fold and oligomeric state of these proteins solubilized in detergent micelles. In this study, an approach to the characterization of detergent-solubilized integral membrane proteins is presented. Eight Thermotoga maritima membrane proteins were screened for solubility in 11 detergents, and the resulting soluble protein–detergent complexes were characterized with small angle X-ray scattering (SAXS), nuclear magnetic resonance (NMR) spectroscopy, circular dichroism (CD) spectroscopy, and chemical cross-linking to evaluate the homogeneity, oligomeric state, radius of gyration, and overall fold. A new application of SAXS is presented, which does not require density matching, and NMR methods, typically used to evaluate soluble proteins, are successfully applied to detergent-solubilized membrane proteins. Although detergents with longer alkyl chains solubilized the most proteins, further characterization indicates that some of these protein–detergent complexes are not well suited for NMR structure determination due to conformational exchange and protein oligomerization. These results emphasize the need to screen several different detergents and to characterize the protein–detergent complex in order to pursue structural studies. Finally, the physical characterization of the protein–detergent complexes indicates optimal solution conditions for further structural studies for three of the eight overexpressed membrane proteins. PMID:16597824

  7. Structural and functional characterization of a noncanonical nucleoside triphosphate pyrophosphatase from Thermotoga maritima

    PubMed Central

    Awwad, Khaldeyah; Desai, Anna; Smith, Clyde; Sommerhalter, Monika

    2013-01-01

    The hyperthermophilic bacterium Thermotoga maritima has a noncanonical nucleoside triphosphatase that catalyzes the conversion of inosine triphosphate (ITP), deoxyinosine triphosphate (dITP) and xanthosine triphosphate (XTP) into inosine monophosphate (IMP), deoxyinosine monophosphate (IMP) and xanthosine monophosphate (XMP), respectively. The k cat/K m values determined at 323 and 353?K fall between 1.31 × 104 and 7.80 × 104? M ?1?s?1. ITP and dITP are slightly preferred over XTP. Activity towards canonical nucleoside triphosphates (ATP and GTP) was not detected. The enzyme has an absolute requirement for Mg2+ as a cofactor and has a preference for alkaline conditions. A protein X-ray structure of the enzyme with bound IMP was obtained at 2.15?Å resolution. The active site houses a well conserved network of residues that are critical for substrate recognition and catalysis. The crystal structure shows a tetramer with two possible dimer interfaces. One of these interfaces strongly resembles the dimer interface that is found in the structures of other noncanonical nucleoside pyrophosphatases from human (human ITPase) and archaea (Mj0226 and PhNTPase). PMID:23385455

  8. Crystal Structures of the Laminarinase Catalytic Domain from Thermotoga maritima MSB8 in Complex with Inhibitors

    PubMed Central

    Jeng, Wen-Yih; Wang, Nai-Chen; Lin, Cheng-Tse; Shyur, Lie-Fen; Wang, Andrew H.-J.

    2011-01-01

    Laminarinases hydrolyzing the ?-1,3-linkage of glucans play essential roles in microbial saccharide degradation. Here we report the crystal structures at 1.65–1.82 ? resolution of the catalytic domain of laminarinase from the thermophile Thermotoga maritima with various space groups in the ligand-free form or in the presence of inhibitors gluconolactone and cetyltrimethylammonium. Ligands were bound at the cleft of the active site near an enclosure formed by Trp-232 and a flexible GASIG loop. A closed configuration at the active site cleft was observed in some molecules. The loop flexibility in the enzyme may contribute to the regulation of endo- or exo-activity of the enzyme and a preference to release laminaritrioses in long chain carbohydrate hydrolysis. Glu-137 and Glu-132 are proposed to serve as the proton donor and nucleophile, respectively, in the retaining catalysis of hydrolyzation. Calcium ions in the crystallization media are found to accelerate crystal growth. Comparison of laminarinase and endoglucanase structures revealed the subtle difference of key residues in the active site for the selection of ?-1,3-glucan and ?-1,4-glucan substrates, respectively. Arg-85 may be pivotal to ?-1,3-glucan substrate selection. The similarity of the structures between the laminarinase catalytic domain and its carbohydrate-binding modules may have evolutionary relevance because of the similarities in their folds. PMID:22065588

  9. Germ cells of the centipede Strigamia maritima are specified early in embryonic development

    PubMed Central

    Green, Jack E.; Akam, Michael

    2014-01-01

    We provide the first systematic description of germ cell development with molecular markers in a myriapod, the centipede Strigamia maritima. By examining the expression of Strigamia vasa and nanos orthologues, we find that the primordial germ cells are specified from at least the blastoderm stage. This is a much earlier embryonic stage than previously described for centipedes, or any other member of the Myriapoda. Using these genes as markers, and taking advantage of the developmental synchrony of Strigamia embryos within single clutches, we are able to track the development of the germ cells throughout embryogenesis. We find that the germ cells accumulate at the blastopore; that the cells do not internalize through the hindgut, but rather through the closing blastopore; and that the cells undergo a long-range migration to the embryonic gonad. This is the first evidence for primordial germ cells displaying these behaviours in any myriapod. The myriapods are a phylogenetically important group in the arthropod radiation for which relatively little developmental data is currently available. Our study provides valuable comparative data that complements the growing number of studies in insects, crustaceans and chelicerates, and is important for the correct reconstruction of ancestral states and a fuller understanding of how germ cell development has evolved in different arthropod lineages. PMID:24930702

  10. Crystallographic analysis of a novel aldo-keto reductase from Thermotoga maritima in complex with NADP(.).

    PubMed

    Hou, Hai; Li, Ruiying; Wang, Xiaoyan; Yuan, Zhen; Liu, Xuemeng; Chen, Zhenmin; Xu, Xiaoling

    2015-07-01

    Aldo-keto reductases (AKRs) are a superfamily of NAD(P)H-dependent oxidoreductases that catalyse the asymmetric reduction of aldehydes and ketones to chiral alcohols in various organisms. The novel aldo-keto reductase Tm1743 from Thermotoga maritima was identified to have a broad substrate specificity and high thermostability, serving as an important enzyme in biocatalysis and fine-chemical synthesis. In this study, Tm1743 was overexpressed in Escherichia coli BL21(DE3) cells with an N-terminal His6 tag and was purified by Ni(2+)-chelating affinity and size-exclusion chromatography. Purified recombinant enzyme was incubated with its cofactor NADP(+) and its substrate ethyl 2-oxo-4-phenylbutyrate (EOPB) for crystallization. Two X-ray diffraction data sets were collected at 2.0 and 1.7?Å resolution from dodecahedral crystals grown from samples containing Tm1743-NADP(+)-EOPB and Tm1743-NADP(+), respectively. Both crystals belonged to space group P3121, with similar unit-cell parameters. However, in the refined structure model only NADP(+) was observed in the active site of the full-length Tm1743 enzyme. Degradation of the N-terminal vector-derived amino acids during crystallization was confirmed by Western blot and mass-spectrometric analyses. PMID:26144229

  11. Crystal structures of Thermotoga maritima reverse gyrase: inferences for the mechanism of positive DNA supercoiling

    PubMed Central

    Rudolph, Markus G.; del Toro Duany, Yoandris; Jungblut, Stefan P.; Ganguly, Agneyo; Klostermeier, Dagmar

    2013-01-01

    Reverse gyrase is an ATP-dependent topoisomerase that is unique to hyperthermophilic archaea and eubacteria. The only reverse gyrase structure determined to date has revealed the arrangement of the N-terminal helicase domain and the C-terminal topoisomerase domain that intimately cooperate to generate the unique function of positive DNA supercoiling. Although the structure has elicited hypotheses as to how supercoiling may be achieved, it lacks structural elements important for supercoiling and the molecular mechanism of positive supercoiling is still not clear. We present five structures of authentic Thermotoga maritima reverse gyrase that reveal a first view of two interacting zinc fingers that are crucial for positive DNA supercoiling. The so-called latch domain, which connects the helicase and the topoisomerase domains is required for their functional cooperation and presents a novel fold. Structural comparison defines mobile regions in parts of the helicase domain, including a helical insert and the latch that are likely important for DNA binding during catalysis. We show that the latch, the helical insert and the zinc fingers contribute to the binding of DNA to reverse gyrase and are uniquely placed within the reverse gyrase structure to bind and guide DNA during strand passage. A possible mechanism for positive supercoiling by reverse gyrases is presented. PMID:23209025

  12. Native crystal structure of a nitric oxide-releasing lectin from the seeds of Canavalia maritima.

    PubMed

    Gadelha, Carlos Alberto de Almeida; Moreno, Frederico Bruno Mendes Batista; Santi-Gadelha, Tatiane; Cajazeiras, João Batista; Rocha, Bruno Anderson Matias da; Assreuy, Ana Maria Sampaio; Lima Mota, Mário Rogério; Pinto, Nilson Vieira; Passos Meireles, Ana Vaneska; Borges, Júlio César; Freitas, Beatriz Tupinamba; Canduri, Fernanda; Souza, Emmanuel Prata; Delatorre, Plínio; Criddle, David Neil; de Azevedo, Walter Filgueira; Cavada, Benildo Sousa

    2005-12-01

    Here, we report the crystallographic study of a lectin from Canavalia maritima seeds (ConM) and its relaxant activity on vascular smooth muscle, to provide new insights into the understanding of structure/function relationships of this class of proteins. ConM was crystallized and its structure determined by standard molecular replacement techniques. The amino acid residues, previously suggested incorrectly by manual sequencing, have now been determined as I17, I53, S129, S134, G144, S164, P165, S187, V190, S169, T196, and S202. Analysis of the structure indicated a dimer in the asymmetric unit, two metal binding sites per monomer, and loops involved in the molecular oligomerization. These confer 98% similarity between ConM and other previously described lectins, derived from Canavalia ensiformis and Canavalia brasiliensis. Our functional data indicate that ConM exerts a concentration-dependent relaxant action on isolated aortic rings that probably occurs via an interaction with a specific lectin-binding site on the endothelium, resulting in a release of nitric oxide. PMID:16337811

  13. The carbohydrate-binding specificity and molecular modelling of Canavalia maritima and Dioclea grandiflora lectins.

    PubMed

    Ramos, M V; Moreira, R de A; Oliveira, J T; Cavada, B S; Rougé, P

    1996-01-01

    The carbohydrate-binding specificity of lectins from the seeds of Canavalia maritima and Dioclea grandiflora was studied by hapten-inhibition of haemagglutination using various sugars and sugar derivatives as inhibitors, including N-acetylneuraminic acid and N-acetylmuramic acid. Despite some discrepancies, both lectins exhibited a very similar carbohydrate-binding specificity as previously reported for other lectins from Diocleinae (tribe Phaseoleae, sub-tribe Diocleinae). Accordingly, both lectins exhibited almost identical hydropathic profiles and their three-dimensional models built up from the atomic coordinates of ConA looked very similar. However, docking experiments of glucose and mannose in their monosaccharide-binding sites, by comparison with the ConA-mannose complex used as a model, revealed conformational changes in side chains of the amino acid residues involved in the binding of monosaccharides. These results fully agree with crystallographic data showing that binding of specific ligands to ConA requires conformational chances of its monosaccharide-binding site. PMID:9283661

  14. Grass shrimp (Palaemonetes spp.) play a pivotal trophic role in enhancing Ruppia maritima.

    PubMed

    McCall, Donna Drury; Rakocinski, Chet F

    2007-03-01

    Coupled trophic-engineer interactions are potentially important for maintaining habitat function and ecosystem services. As ephemeral submerged aquatic vegetation (SAV), Ruppia maritima has a short well-defined growth-senescence cycle and should benefit from any ecological interaction that enhances its physical condition and longevity. Grass shrimp (Palaemonetes spp.) are abundant facultative grazers of epiphytic algae and conveyors of nutrients in tidal marsh and SAV habitats. Grass shrimp addition consistently enhanced Ruppia biomass and shoot density in a series of three field experiments conducted in Grand Bay National Estuarine Research Reserve, Mississippi, USA. In two experiments, epiphyte grazing by grass shrimp enhanced Ruppia by inhibiting die-back during the mid- and latter stages of the Ruppia life cycle. Despite a nonsignificant epiphyte grazing effect, grass shrimp also enhanced Ruppia during its early growth stage in a third experiment. In that experiment, nutrient addition also significantly increased epiphyte biomass. Grass shrimp may have fostered the early growth of Ruppia through direct deposition of feces to the sediment in the third experiment. Grass shrimp play a pivotal trophic role in the maintenance of Ruppia through context-dependent interactions involving stage of the SAV life cycle, season, and nutrient limitation. PMID:17503590

  15. Comprehensive phylogenetic analyses of the Ruppia maritima complex focusing on taxa from the Mediterranean.

    PubMed

    Ito, Yu; Ohi-Toma, Tetsuo; Murata, Jin; Tanaka, Norio

    2013-11-01

    Recent molecular phylogenetic studies reported high diversity of Ruppia species in the Mediterranean. Multiple taxa, including apparent endemics, are known from that region, however, they have thus far not been exposed to phylogenetic analyses aimed at studying their relationships to taxa from other parts of the world. Here we present a comprehensive phylogenetic analyses of the R. maritima complex using data sets composed of DNA sequences of the plastid genome, the multi-copy nuclear ITS region, and the low-copy nuclear phyB gene with a primary focus on the Mediterranean representatives of the complex. As a result, a new lineage, "Drepanensis", was identified as the seventh entity of the complex. This lineage is endemic to the Mediterranean. The accessions included in the former "Tetraploid" entity were reclassified into two entities: an Asia-Australia-Europe disjunct "Tetraploid_?" with a paternal "Diploid" origin, and a European "Tetraploid_?" originating from a maternal "Drepanensis" lineage. Another entity, "Tetraploid_?", is likely to have been originated as a result of chloroplast capture through backcrossing hybridization between paternal "Tetraploid_?" and maternal "Tetraploid_?". Additional discovery of multiple tetraploidizations as well as hybridization and chloroplast capture at the tetraploid level indicated that hybridization has been a significant factor in the diversification of Ruppia. PMID:23728988

  16. Improving thermal stability of thermophilic L-threonine aldolase from Thermotoga maritima.

    PubMed

    Wieteska, Lukasz; Ionov, Maksim; Szemraj, Janusz; Feller, Claudia; Kolinski, Andrzej; Gront, Dominik

    2015-04-10

    Threonine aldolase (TA) catalyzes a reversible reaction, in which threonine is decomposed into glycine and acetaldehyde. The same enzyme can be used to catalyze aldol reaction between glycine and a variety of aromatic and aliphatic aldehydes, thus creating various alpha-amino-alcohols. Therefore, TA is a very promising enzyme that could be used to prepare biologically active compounds or building blocks for pharmaceutical industry. Rational design was applied to thermophilic TA from Thermotoga maritima to improve thermal stability by the incorporation of salt and disulfide bridges between subunits in the functional tetramer. An activity assay together with CD analysis and Western-blot detection was used to evaluate mutants. Except one, each of the designed mutants preserved activity toward the natural substrate. One of the 10 proposed single point mutants, P56C, displayed significantly enhanced stability compared to the wild type (WT). Its initial activity was not affected and persisted longer than WT, proportionally to increased stability. Additionally one of the mutants, W86E, displayed enhanced activity, with stability similar to WT. Higher activity may be explained by a subtle change in active site availability. Salt bridge formation between glutamic acid at position 86 and arginine at position 120 in the neighboring chain may be responsible for the slight shift of the chain fragment, thus creating wider access to the active site both for the substrate and PLP. PMID:25701680

  17. Kaempferol glycosides from Lobularia maritima and their potential role in plant interactions.

    PubMed

    Fiorentino, Antonio; Ricci, Andreina; D'Abrosca, Brigida; Golino, Annunziata; Izzo, Angelina; Pascarella, Maria Teresa; Piccolella, Simona; Esposito, Assunta

    2009-02-01

    Six kaempferol glycosides, four of them characterized for the first time, were isolated from the leaf extract of Lobularia maritima. The structural elucidation was performed by a combined approach using Electrospray-Ionization Triple-Quadrupole Mass-Spectrometric (ESI/TQ/MS) techniques, and 1D- and 2D-NMR experiments (1H, 13C, DEPT, DQ-COSY, TOCSY, ROESY, NOESY, HSQC, HMBC, and HSQC-TOCSY). The isolated kaempferol derivatives have different disaccharide substituents at C(3) and four of them have a rhamnose unit at C(7). To evaluate their potential allelopathic role within the herbaceous plant community, the compounds, as well as the aglycone obtained from enzymatic hydrolysis, have been tested in vitro on three coexisting plant species, Dactylis hispanica, Petrorhagia velutina, and Phleum subulatum. The results obtained allow us to hypothesize that the type of the sugar modulates the biological response. The bioassay data, analyzed by a multivariate approach, and grouping the compounds on the basis of the number of sugar units and the nature of carbohydrates present in the disaccharide moiety, indicate a structure-activity relationship. PMID:19235162

  18. In the halotolerant Lobularia maritima (Brassicaceae) salt adaptation correlates with activation of the vacuolar H(+)-ATPase and the vacuolar Na+/H+ antiporter.

    PubMed

    Popova, Olga V; Golldack, Dortje

    2007-10-01

    Lobularia maritima (Brassicaceae) is a facultative halophyte related to Arabidopsis thaliana and may be a suitable model to identify molecular mechanisms that regulate tolerance to salt stress in plants. Under the same salt stress conditions, the accumulation of sodium was similar in shoots and roots of Lobularia maritima and Arabidopsis thaliana, whereas the sodium to potassium ratio was less in Lobularia maritima. Aquaporins, the NHX-type Na(+)/H(+) antiporter, and the vacuolar ATPase are well established targets of regulation under salt stress that have a central role in the control of water status and cytoplasmic sodium homeostasis. Therefore, salt-dependent expression of transcripts encoding a PIP2;1 aquaporin, the Na(+)/H(+) antiporter NHX, and V-ATPase subunit E (VHA-E) was characterized in Lobularia maritima. Transcription of LmPIP2;1 was repressed in leaves and roots by treatment with 500mM NaCl. In contrast, salt stress stimulated the expression of LmNHX1 and LmVHA-E. Cell-specificity of the transcription of LmNHX1 was analyzed by fluorescence in situ PCR in leaf cross sections of Lobularia maritima. Expression of the gene was localized to the phloem and to mesophyll cells. In plants treated with 500 mM NaCl, transcription of LmNHX1 was stimulated in the mesophyll. The findings indicate divergent transcriptional responses of key mechanisms of salt adaptation in Lobularia maritima and suggest distinct regulation of sodium homeostasis and water flux under salt stress. PMID:17166622

  19. Comparison of the amino acid sequences of the lectins from seeds of Dioclea lehmanni and Canavalia maritima.

    PubMed

    Perez, G; Perez, C; Sousa-Cavada, B; Moreira, R; Richardson, M

    1991-01-01

    The amino acid sequences of the major lectins from the seeds of Dioclea lehmanni and Canavalia maritima were determined by DABITC/PITC microsequence analysis of peptides derived from the proteins by enzymatic digestions with trypsin, chymotrypsin and the protease from S. aureus V8. These sequences were found to be very similar to those of the lectins from Dioclea grandiflora and Canavalia ensiformis (Con A). The D. lehmanni lectin was unusual amongst legume lectins in that it contained a single Cys. PMID:1367779

  20. Functional and structural characterization of a thermostable acetyl esterase from Thermotoga maritima

    PubMed Central

    Levisson, Mark; Han, Gye Won; Deller, Marc C.; Xu, Qingping; Biely, Peter; Hendriks, Sjon; Ten Eyck, Lynn F.; Flensburg, Claus; Roversi, Pietro; Miller, Mitchell D.; McMullan, Daniel; von Delft, Frank; Kreusch, Andreas; Deacon, Ashley M.; van der Oost, John; Lesley, Scott A.; Elsliger, Marc-André; Kengen, Servé W. M.; Wilson, Ian A.

    2012-01-01

    TM0077 from Thermotoga maritima is a member of the carbohydrate esterase family 7 and is active on a variety of acetylated compounds, including cephalosporin C. TM0077 esterase activity is confined to short-chain acyl esters (C2-C3), and is optimal around 100°C and pH 7.5. The positional specificity of TM0077 was investigated using 4-nitrophenyl-?-D-xylopyranoside monoacetates as substrates in a ?-xylosidase-coupled assay. TM0077 hydrolyzes acetate at positions 2, 3 and 4 with equal efficiency. No activity was detected on xylan or acetylated xylan, which implies that TM0077 is an acetyl esterase and not an acetyl xylan esterase as currently annotated. Selenomethionine-substituted and native structures of TM0077 were determined at 2.1 Å and 2.5 Å resolution, respectively, revealing a classic ?/?-hydrolase fold. TM0077 assembles into a doughnut-shaped hexamer with small tunnels on either side leading to an inner cavity, which contains the six catalytic centers. Structures of TM0077 with covalently bound phenylmethylsulfonyl fluoride (PMSF) and paraoxon were determined to 2.4 Å and 2.1 Å, respectively, and confirmed that both inhibitors bind covalently to the catalytic serine (Ser188). Upon binding of inhibitor, the catalytic serine adopts an altered conformation, as observed in other esterase and lipases, and supports a previously proposed catalytic mechanism in which this Ser hydroxyl rotation prevents reversal of the reaction and allows access of a water molecule for completion of the reaction. PMID:22411095

  1. Flowering time in wild beet ( Beta vulgaris ssp. maritima) along a latitudinal cline

    NASA Astrophysics Data System (ADS)

    Dijk, Henk Van; Boudry, Pierre; McCombre, Helen; Vernet, Philippe

    The wild beet ( Beta vulgaris ssp. maritima, a perennial species from the Mediterranean and the European Atlantic coasts) shows marked variation in flowering time in terms of both the year of first flowering and flowering date in a given year. Much of this variability is related to latitude. Beta vulgaris plants flower either in the same year as they germinate or in their second year. This is mainly due to differences in their requirement for vernalization, which is determined by a single gene B/b and by quantitative trait loci. The more southern the origin of the plants, the less vernalization is required. Also the B allele, which cancels vernalization requirement completely, has a high frequency in the Mediterranean region, but is completely absent in the northern part of the distribution of this species. We found that flowering date variation in relation to the latitude of origin is maintained under greenhouse conditions but does not follow a simple clinal relationship. From the Mediterranean northwards to the west coast of Brittany, flowering occurs progressively earlier, but from Brittany northwards to south-east England and The Netherlands it is progressively later. A possible explanation for this difference is that in the southern part of the range sensitivity to daylength and warmth control flowering time, whereas further north vernalization requirement is also a key factor. A substantial part of all differences in flowering time was heritable: heritability within populations was measured as 0.33 under greenhouse conditions. The high heritability implies evolutionary change may occur in this character.

  2. Estimation of the non-seasonal production of Spartina maritima (Curtis) Fernald in a South African Estuary

    NASA Astrophysics Data System (ADS)

    Pierce, Shirley M.

    1983-03-01

    Net aerial production of Spartina maritima (Curtis) Fernald, in a warm temperature estuary in Algoa Bay, South Africa, occurring possibly as an exotic, was estimated as 523-680 g dry weight m -2 year -1. The method of production measurement designed here used community structure data and accounted for the species' extremely slow shoot production (3.1-6.7 dry g m -2 year -1) and continuous leaf turnover (516-676 dry g m -2 year -1). Standard methods of production measurement for other Spartina species failed by not accounting for the non-seasonal growth of S. maritima. N, C, organic and energy content of live and dead shoots remained constant through the seasons. The P : B ratio is 1.1, which is lower than for other Spartina species, but agrees with the low vigour shown by negligible regrowth a year after clipping. Decomposition rates were 90 mg g -1 month -1 in winter and 305 mg g -1 month -1 in summer. Monthly decomposition values showed significant correlation with air temperature ( r = 0.86; P < 0.01), and water temperature ( r = 0.80; P < 0.01), suggesting that monthly litterbag losses are a valid means of determining decomposition rate.

  3. [Morphogenetic lability of reproductive structures in Ruppia maritima (Ruppiaceae, Alismatales): from two lateral flowers to a terminal flower].

    PubMed

    Lokk, I É; Sokolov, D D; Remizova, M V

    2011-01-01

    Flowers of Ruppia are normally arranged into an open two-flowered spike, but sometimes the two lateral flowers are congenitally united with each other and form a terminal flower-like structure. This developmental abnormality resembles those described in well-investigated mutants of model organisms of developmental genetics such as Arabidopsis Antirrhinum. A study of Ruppia allows investigating morphogenetic lability of this feature in natural populations. These data will be important for understanding evolutionary transitions between open and closed inflorescences. This paper presents first data on frequencies ofterminal flower-like structures in natural populations of Ruppia maritima and first observations of their development. Vascular supply of inflorescences with free and united flowers is compared for the first time. Strong differences in frequencies of occurrence of terminal flower-like structures among examined natural populations are revealed. Data on variation of organ numbers in flowers of plants from different populations allow hypothesizing that increased size of floral primordia is a factor that plays a role in their amalgamation into ajoint primordium of a terminal structure. Vascular system of inflorescences of R. maritima with united flowers is quite similar to the vascular system of a flower and nothing contradicts a hypothesis on terminal position ofthis structure. Transversally inserted stamens in inflorescences with united flowers are usually of inverted polarity. This appears to be the first documented example of an inversion of relative polarity of stamens and carpels in angiosperms. PMID:21950054

  4. Selenium accumulation in submerged aquatic macrophytes Potamogeton pectinatus L. and Ruppia maritima L. from water with elevated chloride and sulfate salinity.

    PubMed

    Wu, Lin; Guo, Xun

    2002-01-01

    Submerged aquatic macrophyte species Potamogeton crispus L. (curlyleaf pondweed) and Ruppia maritima L. (widegeongrass) were examined for selenium accumulation from agricultural drainage water in the field and under laboratory conditions. High concentrations of chloride and sulfate salts were found in the drainage water of the constructed wetland at Tulare Lake Drainage District, Corcorn, California. Samples of P. crispus and R. maritima collected from the field, had similar plant-tissue Se concentrations, but the rhizomes accumulated significantly greater amounts of Se than the shoot tissues. When the plants were grown in culture solution supplemented with either chloride or sulfate salt, R. maritima was found to be more salt tolerant than P. crispus, and P. crispus accumulated more Se than R. maritima. Free seleno-amino acids were detected in the plant tissue, and organic Se was detected in the culture solution after 10 days of growth. The release of organic Se into the water by the plants may have a negative impact on the wetland environment. PMID:11800546

  5. Selenium Accumulation in Submerged Aquatic Macrophytes Potamogeton pectinatus L. and Ruppia maritima L. from Water with Elevated Chloride and Sulfate Salinity

    Microsoft Academic Search

    Lin Wu; Xun Guo

    2002-01-01

    Submerged aquatic macrophyte species Potamogeton crispus L. (curlyleaf pondweed) and Ruppia maritima L. (widegeongrass) were examined for selenium accumulation from agricultural drainage water in the field and under laboratory conditions. High concentrations of chloride and sulfate salts were found in the drainage water of the constructed wetland at Tulare Lake Drainage District, Corcorn, California. Samples of P. crispus and R.

  6. Effect of Bioflavonoids Extracted from the Bark of Pinus maritima on Proinflammatory Cytokine Interleukin1 Production in Lipopolysaccharide-Stimulated RAW 264.7

    Microsoft Academic Search

    Kyung-Joo Cho; Chang-Hyun Yun; Do-Young Yoon; Young-Sik Cho; Gerald Rimbach; Lester Packer; An-Sik Chung

    2000-01-01

    Currently, bioflavonoids have been known to have strong antioxidant capacities, and a variety of efforts have been made to identify the utilities of bioflavonoids in treating various diseases based on their antioxidant capacities. The effects of bioflavonoids extracted from the bark of Pinus maritima Pycnogenol (PYC) on free radical formation, activation of redox sensitive transcription factors, as well as interleukin-1?

  7. THE [Fe-Fe]-HYDROGENASE MATURATION PROTEIN HydF FROM Thermotoga maritima IS A GTPase WITH AN IRON-SULFUR CLUSTER

    E-print Network

    Paris-Sud XI, Université de

    1 THE [Fe-Fe]-HYDROGENASE MATURATION PROTEIN HydF FROM Thermotoga maritima IS A GTPase WITH AN IRON-SULFUR-Fe]-hydrogenases (1), [Fe-Fe]-hydrogenases (2,3) and "Iron-Sulfur cluster- free" hydrogenase (4,5,6), which do for activity (10). Infrared spectroscopy studies have also demonstrated the presence of CO ligands in the "Iron-Sulfur

  8. A dynamic simulation model of the widgeon grass Ruppia maritima and its epiphytes in the estuary of the Patos Lagoon, RS, Brazil

    Microsoft Academic Search

    Eduardo Teixeira da Silva; Milton L. Asmus

    2001-01-01

    The dynamics of the vegetated beds of the estuary of the Patos Lagoon was investigated using a simulation model for two important benthic primary producers (the widgeon grass Ruppiamaritima and its epiphytes). The model, of deterministic characteristics, simulated two development cycles of the beds from summer 1992\\/1993 to 1993\\/1994. Model validation and calibration were accomplished by using R. maritima biomass

  9. The role of fish in distribution and germination of seeds of the submerged macrophytes Najas marina L. and Ruppia maritima L

    Microsoft Academic Search

    M. Agami; Y. Waisel

    1988-01-01

    The effects of three species of fish (tilapia, grass carp and common carp) on the seeds of Najas marina L. and of Ruppia maritima L. were investigated. Practically all the seeds that were injested by the common carp were digested. The two other fish were less affective: they digested seeds with soft seed-coats but excreted a good portion of the

  10. Nutritional and microbiological features of little known legumes, Canavalia cathartica Thouars and C. maritima Thouars of the southwest coast of India

    Microsoft Academic Search

    S. Seena; K. R. Sridhar

    1 . The CSDs and mangroves of the southwest coast of India are rich niches for two under-exploited legumes, Canavalia cathartica Thouars (synonyms: C. m icrocarpa (DC.) Piper; C. turgida Graham ex A. Gray; C. virosa (Roxb.) Wight et Arn.; Dolichos virosus Roxb.; Lablab microcar- pus DC.), and Canavalia maritima Thouars (synonyms: C. lineata (Thunb.) DC.; C. obtusifolia (Lam.) DC.;

  11. Testing the potential of White mustard (Sinapis alba) and Sweet alyssum (Lobularia maritima) as trap crops for the Diamondback moth Plutella xylostella

    Microsoft Academic Search

    Maarten de Groot; Karin Winkler; Roel P. J. Potting

    Ideal characteristics of a plant species implemented in a trap cropping strategy are a high attractivity to ovipositing adults, and a low suitability for larval development. The potential of the crucifers Sinapis alba (L.) and Lobularia maritima (L.) as trap crops for the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae) was evaluated. The larval performance on the trap crop plants

  12. Investigations into the effects of environmental and physical variables on the growth of natural and transplanted populations of Ruppia maritima L. s.l. in the Galveston Bay System, Texas 

    E-print Network

    Schubert, William James

    2002-01-01

    The effects of sixteen environmental and physical variables on the growth of six natural populations and on the establishment and growth of transplanted populations of widgeon grass, Ruppia maritima L. s.l., were evaluated in the Galveston Bay...

  13. Emergence of gynodioecy in wild beet (Beta vulgaris ssp. maritima L.): a genealogical approach using chloroplastic nucleotide sequences

    PubMed Central

    Fénart, Stéphane; Touzet, Pascal; Arnaud, Jean-François; Cuguen, Joël

    2006-01-01

    Gynodioecy is a breeding system where both hermaphroditic and female individuals coexist within plant populations. This dimorphism is the result of a genomic interaction between maternally inherited cytoplasmic male sterility (CMS) genes and bi-parentally inherited nuclear male fertility restorers. As opposed to other gynodioecious species, where every cytoplasm seems to be associated with male sterility, wild beet Beta vulgaris ssp. maritima exhibits a minority of sterilizing cytoplasms among numerous non-sterilizing ones. Many studies on population genetics have explored the molecular diversity of different CMS cytoplasms, but questions remain concerning their evolutionary dynamics. In this paper we report one of the first investigations on phylogenetic relationships between CMS and non-CMS lineages. We investigated the phylogenetic relationships between 35 individuals exhibiting different mitochondrial haplotypes. Relying on the high linkage disequilibrium between chloroplastic and mitochondrial genomes, we chose to analyse the nucleotide sequence diversity of three chloroplastic fragments (trnK intron, trnD–trnT and trnL–trnF intergenic spacers). Nucleotide diversity appeared to be low, suggesting a recent bottleneck during the evolutionary history of B. vulgaris ssp. maritima. Statistical parsimony analyses revealed a star-like genealogy and showed that sterilizing haplotypes all belong to different lineages derived from an ancestral non-sterilizing cytoplasm. These results suggest a rapid evolution of male sterility in this taxon. The emergence of gynodioecy in wild beet is confronted with theoretical expectations, describing either gynodioecy dynamics as the maintenance of CMS factors through balancing selection or as a constant turnover of new CMSs. PMID:16777728

  14. Phenological development stages variation versus mercury tolerance, accumulation, and allocation in salt marsh macrophytes Triglochin maritima and Scirpus maritimus prevalent in Ria de Aveiro coastal lagoon (Portugal).

    PubMed

    Anjum, Naser A; Ahmad, Iqbal; Válega, Mónica; Figueira, Etelvina; Duarte, Armando C; Pereira, Eduarda

    2013-06-01

    Efficient and sustainable management of rapidly mounting environmental issues has been the focus of current intensive research. The present study aimed to investigate the impact of plant phenological development stage variation on mercury (Hg) tolerance, accumulation, and allocation in two salt marsh macrophytes Triglochin maritima and Scirpus maritimus prevalent in historically Hg-contaminated Ria de Aveiro coastal lagoon (Portugal). Both plant samples and the sediments vegetated by monospecific stands of T. maritima and S. maritimus were collected from reference (R) and sites with moderate (M) and high (H) Hg contamination in Laranjo bay within Ria de Aveiro lagoon. Hg tolerance, uptake, and allocation in T. maritima and S. maritimus, physico-chemical traits (pH, redox potential, and organic matter content) and Hg concentrations in sediments vegetated by these species were impacted differentially by phenological development stages variation irrespective of the Hg contamination level. In T. maritima, Hg concentration increased with increase in Hg contamination gradient where root displayed significantly higher Hg followed by rhizome and leaf maximally at H. However, in S. maritimus, the highest Hg concentration was perceptible in rhizome followed by root maximally at M. Between the two studied plant species, S. maritimus displayed higher Hg tolerance index (depicted by higher plant dry mass allocated to reproductive stage) and higher available Hg at M (during all growth stages) and H (during senescent stage) when compared to T. maritimus. Both plant species proved to be Hg excluder (low root/rhizome-leaf Hg translocation). Additionally, T. maritima also acted as Hg stabilizer while, S. maritimus as Hg accumulator. It can be inferred from the study that (a) the plant phenological development stage variations significantly influenced plant Hg sensitivity by impacting sediment chemistry, plant growth (in terms of plant dry mass), Hg accumulation, and its subsequent allocation capacity, contingent to Hg contamination gradient; (b) S. maritimus accumulated higher Hg but restricted its translocation to above-ground part using exclusion process at both M and H due to its accelerated growth during Hg-tolerant reproductive/metabolically active phenological development stage greater than its counterpart T. maritima; and (c) the studied salt marsh plants although hailed from the same C3 and monocot group did not necessarily display similar phenotypic plasticity and behavior towards Hg-contaminated scenario during their life cycle. PMID:23184133

  15. Transglycosylation reaction of xylanase B from the hyperthermophilic Thermotoga maritima with the ability of synthesis of tertiary alkyl ?- d-xylobiosides and xylosides

    Microsoft Academic Search

    Zhengqiang Jiang; Yunping Zhu; Lite Li; Xiaohong Yu; Isao Kusakabe; Motomistu Kitaoka; Kiyoshi Hayashi

    2004-01-01

    The recombinant xylanase B (XynB) of Thermotoga maritima MSB8 was characterized and was found to cleave p-nitrophenyl ?-d-xyloside via the transglycosylation reaction in the previous study. XynB was activated in the presence of alcohols, and XynB activity was increased by iso-propanol (2M) to 2.1-fold. This type of activation was investigated and was shown to be due to the transglycosylation activity

  16. The DnaA homolog of the hyperthermophilic eubacterium Thermotoga maritima forms an open complex with a minimal 149-bp origin region in an ATP-dependent manner

    Microsoft Academic Search

    Shogo Ozaki; Kazuyuki Fujimitsu; Hitoshi Kurumizaka; Tsutomu Katayama

    2006-01-01

    In Escherichia coli , ATP-DnaA, but not ADP-DnaA, forms an initiation complex that undergoes site-specific duplex DNA unwinding, open complex formation. However, it remains unclear how highly the ATP-dependent activation of the initiation factor is conserved in evolution. The hyper- thermophile Thermotoga maritima is one of the most ancient eubacteria in evolution. Here, we show that the DnaA homolog (

  17. Crystal structure of a lectin from Canavalia maritima (ConM) in complex with trehalose and maltose reveals relevant mutation in ConA-like lectins

    Microsoft Academic Search

    Plínio Delatorre; Bruno A. M. Rocha; Carlos A. A. Gadelha; Tatiane Santi-Gadelha; João B. Cajazeiras; Emmanuel P. Souza; Kyria S. Nascimento; Valder N. Freire; Alexandre H. Sampaio; Walter F. Azevedo; Benildo S. Cavada

    2006-01-01

    The crystal structure of Canavalia maritima lectin (ConM) complexed with trehalose and maltose revealed relevant point mutations in ConA-like lectins. ConM with the disaccharides and other ConA-like lectins complexed with carbohydrates demonstrated significant differences in the position of H-bonds. The main difference in the ConM structure is the replacement of Pro202 by Ser202, a residue that promotes the approximation of

  18. Overexpression of GH10 endoxylanase XynB from Thermotoga maritima in Escherichia coli by a novel vector with potential for industrial application

    Microsoft Academic Search

    Huawei Wu; Jianjun Pei; Guogan Wu; Weilan Shao

    2008-01-01

    The GH10 endoxylanase B encoded by xynB of Thermotoga maritima is a particularly attractive candidate for some industrial purposes. In present study, we aimed to develop an expression system to increase the enzyme production and decrease the costs in the induction of xynB expression in Escherichia coli. The xylanase was overexpressed in E. coli by using the novel pHsh expression

  19. Subcellular concentrations of sugar alcohols and sugars in relation to phloem translocation in Plantago major, Plantago maritima , Prunus persica , and Apium graveolens

    Microsoft Academic Search

    Jan Nadwodnik; Gertrud Lohaus

    2008-01-01

    Sugar and sugar alcohol concentrations were analyzed in subcellular compartments of mesophyll cells, in the apoplast, and\\u000a in the phloem sap of leaves of Plantago major (common plantain), Plantago maritima (sea plantain), Prunus persica (peach) and Apium graveolens (celery). In addition to sucrose, common plantain, sea plantain, and peach also translocated substantial amounts of sorbitol,\\u000a whereas celery translocated mannitol as

  20. Changes in the abundance of the seagrasses Zostera marina L. (eelgrass) and Ruppia maritima L. (widgeongrass) in San Diego, California, following and El Niño Event

    Microsoft Academic Search

    Megan R. Johnson; Susan L. Williams; Carolyn H. Lieberman; Arne Solbak

    2003-01-01

    Changes in environmental conditions can be accompanied by shifts in the distribution and abundances of organisms. When physical\\u000a factors become unsuitable for growth ofZostera marina (eelgrass), which is a dominant seagrass species in North America, other more ruderal seagrass species, includingRuppia maritima (widgeongrass), often increase in abundance or replace the dominant species. We report the proliferation of widgeongrass\\u000a into eelgrass

  1. Salt-inducible isoform of plasma membrane H+ATPase gene in rice remains constitutively expressed in natural halophyte, Suaeda maritima.

    PubMed

    Sahu, Binod Bihari; Shaw, Birendra Prasad

    2009-07-01

    To look into a possible involvement of plasma membrane H+ATPase (PM-H+ATPase, EC 3.6.3.6) in mitigation of physiological disturbances imposed by salt stress, response of the enzyme was studied in two Oryza sativa Indica cultivars, salt-tolerant Lunishri and non-tolerant Badami, and a natural halophyte Suaeda maritima after challenge of the young plants with NaCl. Significant increase in activity of the enzyme was observed in response to NaCl in all the test plants with S. maritima showing maximum increase. Protein blot analysis, however, did not show any increase in the amount of the enzyme (protein). RNA blot analysis, on the other hand, revealed significant increase in transcript level of the enzyme upon NaCl treatment. In the rice cultivars, salt treatment also induced expression of a new isoform of PM-H+ATPase gene, not reported so far. The induced transcript showed maximum homology to OSA7 (O. sativa PM-H+ATPase isoform 7). Similar transcript message, however, remained constitutively present in S. maritima, along with the transcript of another isoform of PM-H+ATPase showing resemblance to OSA3 (O. sativa PM-H+ATPase isoform 3). The latter was the only PM-H+ATPase isoform expressed in both the rice cultivars not exposed to NaCl. In the salt-treated test plants, both rice and S. maritima, the salt-inducible PM-H+ATPase isoform resembling OSA7 was expressed in much greater amount than that resembling OSA3. Appearance of a new PM-H+ATPase transcript, besides increase in the enzyme activity, indicates the important role of the enzyme in maintaining ion-homeostasis in plants under salt stress, enabling them to survive under saline conditions. PMID:19167778

  2. Crystal structure of NusA from Thermotoga maritima and functional implication of the N-terminal domain.

    PubMed

    Shin, Dong Hae; Nguyen, Henry Huy; Jancarik, Jaru; Yokota, Hisao; Kim, Rosalind; Kim, Sung-Hou

    2003-11-25

    We report the crystal structure of N-utilizing substance A protein (NusA) from Thermotoga maritima (TmNusA), a protein involved in transcriptional pausing, termination, and antitermination. TmNusA has an elongated rod-shaped structure consisting of an N-terminal domain (NTD, residues 1-132) and three RNA binding domains (RBD). The NTD consists of two subdomains, the globular head and the helical body domains, that comprise a unique three-dimensional structure that may be important for interacting with RNA polymerase. The globular head domain possesses a high content of negatively charged residues that may interact with the positively charged flaplike domain of RNA polymerase. The helical body domain is composed of a three-helix bundle that forms a hydrophobic core with the aid of two neighboring beta-strands. This domain shows structural similarity with one of the helical domains of sigma(70) factor from Escherichia coli. One side of the molecular surface shows positive electrostatic potential suitable for nonspecific RNA interaction. The RBD is composed of one S1 domain and two K-homology (KH) domains forming an elongated RNA binding surface. Structural comparison between TmNusA and Mycobacterium tuberculosis NusA reveals a possible hinge motion between NTD and RBD. In addition, a functional implication of the NTD in its interaction with RNA polymerase is discussed. PMID:14621988

  3. Structure-based modification of D-alanine-D-alanine ligase from Thermotoga maritima ATCC 43589 for depsipeptide synthesis.

    PubMed

    Nakagawa, Tomoki; Satake, Ryoko; Sato, Masaru; Kino, Kuniki

    2011-01-01

    Depsipeptides are peptide-like polymers consisting of amino acids and hydroxy acids, and are expected to be new functional materials for drug-delivery systems and polymer science. In our previous study, D-alanyl-D-lactate, a type of depsipeptide, was enzymatically synthesized using D-alanine-D-alanine ligase from Thermotoga maritima ATCC 43589 (TmDdl) by Y207F substitution. Thereafter, in this study, further mutagenesis was introduced, based on structural comparison between TmDdl and a well-characterized D-alanine-D-alanine ligase from Escherichia coli. The S137A/Y207F mutant showed higher D-alanyl-D-lactate and lower D-alanyl-D-alanine synthesizing activity than the Y207F mutant. This suggests that substitution at the S137 residue contributes to product selectivity. Saturated mutagenesis on S137 revealed that the S137G/Y207F mutant showed the highest D-alanyl-D-lactate synthesizing activity. Moreover, the mutant showed broad substrate specificity toward D-amino acid and recognized D-lactate and D,L-isoserine as substrates. On the basis of these characteristics, various depsipeptides can be produced using S137G/Y207F-replaced TmDdl. PMID:21512246

  4. Nutritional and biological qualities of the ripened beans of Canavalia maritima from the coastal sand dunes of India.

    PubMed

    Bhagya, B; Sridhar, K R; Raviraja, N S; Young, C-C; Arun, A B

    2009-01-01

    Raw and pressure-cooked ripened beans of Canavalia maritima were assessed for nutritional quality. The beans possess high protein, carbohydrate, fiber and energy contents. Potassium, magnesium, zinc and manganese of the raw and cooked beans meet NRC/NAS recommended pattern for infants. The essential amino acids (threonine, valine, isoleucine, leucine, tyrosine/phenylalanine and lysine) in raw and cooked ripened beans fulfill the FAO/WHO/UNU recommended pattern for adults. Oleic acid in raw beans and linolenic acid in cooked beans were highest and linoleic and arachidonic acids were confined to raw beans. Cooking lowered the total phenolics, while tannins were negligible and devoid of orthodihydric phenols and trypsin inhibitors. Hemagglutinating activity decreased up to 50% in cooked beans. Rats fed with a pressure-cooked bean diet showed significant elevation of all growth and nitrogen balance parameters (P<0.05) than the rats which received the raw bean diet. The low protein quality of beans warrants appropriate thermal processing to eliminate antinutritional factors. PMID:19200923

  5. The Crystal Structure of Thermotoga maritima Class III Ribonucleotide Reductase Lacks a Radical Cysteine Pre-Positioned in the Active Site

    PubMed Central

    Aurelius, Oskar; Johansson, Renzo; Bågenholm, Viktoria; Lundin, Daniel; Tholander, Fredrik; Balhuizen, Alexander; Beck, Tobias; Sahlin, Margareta; Sjöberg, Britt-Marie; Mulliez, Etienne; Logan, Derek T.

    2015-01-01

    Ribonucleotide reductases (RNRs) catalyze the reduction of ribonucleotides to deoxyribonucleotides, the building blocks for DNA synthesis, and are found in all but a few organisms. RNRs use radical chemistry to catalyze the reduction reaction. Despite RNR having evolved several mechanisms for generation of different kinds of essential radicals across a large evolutionary time frame, this initial radical is normally always channelled to a strictly conserved cysteine residue directly adjacent to the substrate for initiation of substrate reduction, and this cysteine has been found in the structures of all RNRs solved to date. We present the crystal structure of an anaerobic RNR from the extreme thermophile Thermotoga maritima (tmNrdD), alone and in several complexes, including with the allosteric effector dATP and its cognate substrate CTP. In the crystal structure of the enzyme as purified, tmNrdD lacks a cysteine for radical transfer to the substrate pre-positioned in the active site. Nevertheless activity assays using anaerobic cell extracts from T. maritima demonstrate that the class III RNR is enzymatically active. Other genetic and microbiological evidence is summarized indicating that the enzyme is important for T. maritima. Mutation of either of two cysteine residues in a disordered loop far from the active site results in inactive enzyme. We discuss the possible mechanisms for radical initiation of substrate reduction given the collected evidence from the crystal structure, our activity assays and other published work. Taken together, the results suggest either that initiation of substrate reduction may involve unprecedented conformational changes in the enzyme to bring one of these cysteine residues to the expected position, or that alternative routes for initiation of the RNR reduction reaction may exist. Finally, we present a phylogenetic analysis showing that the structure of tmNrdD is representative of a new RNR subclass IIIh, present in all Thermotoga species plus a wider group of bacteria from the distantly related phyla Firmicutes, Bacteroidetes and Proteobacteria. PMID:26147435

  6. Ferulic acid excretion as a marker of consumption of a French maritime pine (Pinus maritima) bark extract.

    PubMed

    Virgili, F; Pagana, G; Bourne, L; Rimbach, G; Natella, F; Rice-Evans, C; Packer, L

    2000-04-15

    French maritime pine (Pinus maritima) bark extract (PBE) is a polyphenol-rich food supplement patented under the name of Pycnogenol and known to have strong antioxidant activity and different beneficial effects on human health. Although its biological properties have begun to be extensively studied both in vitro, in laboratory animals and more recently in humans, little is known about its bioavailability. The present study investigated the urinary excretion of free and conjugated ferulic acid, present in quantitatively detectable amounts in PBE, after oral PBE administration to human subjects. Eleven healthy adult subjects (4 women and 7men) consumed either a single dose (200 mg PBE) or two doses of PBE (100 and 200 mg, respectively) within a 48-h interval. Two days before the oral administration of PBE and during the urine sample collection period volunteers adhered to a diet low in polyphenols. Aliquots of all urine production were collected over 24 h. Free and conjugated ferulic acid was assessed in urine by HPLC using diode array detection. A close association between the dietary intake of PBE and the urinary excretion of ferulic acid was detected. Moreover, the results indicate that a considerable proportion of ferulic acid is excreted as glucuronide or sulfate after PBE consumption, varying over the range 2 to 20% between individuals. The kinetics of excretion associated with the administration of 100 mg PBE was quite similar to that obtained after 200 mg PBE. A a biphasic trend was evident in a number of subjects. All subjects studied here displayed a significant, although variable level of excretion of ferulic acid after supplementation with PBE, Thus, the data provide evidence that at least a part of the phenolic components of PBE are absorbed, metabolized, and eliminated by humans. PMID:10889455

  7. The interaction of ammonia and xenon with the imidazole glycerol phosphate synthase from Thermotoga maritima as detected by NMR spectroscopy

    PubMed Central

    Liebold, Christoph; List, Felix; Kalbitzer, Hans Robert; Sterner, Reinhard; Brunner, Eike

    2010-01-01

    The imidazole glycerol phosphate (ImGP) synthase from the hyperthermophilic bacterium Thermotoga maritima is a 1:1 complex of the glutaminase subunit HisH and the cyclase subunit HisF. It has been proposed that ammonia generated by HisH is transported through a channel to the active site of HisF, which generates intermediates of histidine (ImGP) and de novo biosynthesis of 5-aminoimidazole-4-carboxamideribotide. Solution NMR spectroscopy of ammonium chloride-titrated samples was used to study the interaction of NH3 with amino acids inside this channel. Although numerous residues showed 15N chemical shift changes, most of these changes were caused by nonspecific ionic strength effects. However, several interactions appeared to be specific. Remarkably, the amino acid residue Thr 78—which is located in the central channel—shows a large chemical shift change upon titration with ammonium chloride. This result and the reduced catalytic activity of the Thr78Met mutant indicate a special role of this residue in ammonia channeling. To detect and further characterize internal cavities in HisF, which might for example contribute to ammonia channeling, the interaction of HisF with the noble gas xenon was analyzed by solution NMR spectroscopy using 1H-15N HSQC experiments. The results indicate that HisF contains three distinct internal cavities, which could be identified by xenon-induced chemical shift changes of the neighboring amino acid residues. Two of these cavities are located at the active site at opposite ends of the substrate N?-[(5?-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamide-ribonucleotide (PRFAR) binding groove. The third cavity is located in the interior of the central ?-barrel of HisF and overlaps with the putative ammonia transport channel. PMID:20665694

  8. Enhanced catalytic efficiency in quercetin-4'-glucoside hydrolysis of Thermotoga maritima ?-glucosidase A by site-directed mutagenesis.

    PubMed

    Sun, Huihui; Xue, Yemin; Lin, Yufei

    2014-07-16

    Te-BglA and Tm-BglA are glycoside hydrolase family 1 ?-glucosidases from Thermoanaerobacter ethanolicus JW200 and Thermotoga maritima, respectively, with 53% sequence identity. However, Te-BglA could more effectively hydrolyze isoflavone glucosides to their aglycones than could Tm-BglA, possibly due to the difference in amino acid residues around their glycone binding pockets. Site-directed mutagenesis was used to replace the amino acid residues of Tm-BglA with the corresponding residues of Te-BglA, generating three single mutants (F221L, N223L, and G224T), as well as the corresponding three double mutants (F221L/N223L, F221L/G224T, and N223L/G224T) and one triple mutant (F221L/N223L/G224T). The seven mutants have been purified, characterized, and compared to the wild-type Tm-BglA. The effects of the mutations on kinetics, enzyme activity, and substrate specificity were determined. All mutants showed pH-activity curves narrower on the basic side and wider on the acid side and had similar optimal pH and stability at pH 6.5-8.3. They were more stable up to 85 °C, but G224T displayed higher optimal temperature than Tm-BglA. Seven mutants indicated an obvious increase in catalytic efficiency toward p-nitrophenyl ?-D-glucopyranoside (pNPG) but an increase or not change in K(m). All mutants showed a decrease in catalytic efficiency of isoflavonoid glycosides and were not changed for F221L and lost for N223L in enzymatic hydrolysis on quercetin glucosides. Contrarily, G224T resulted in a dramatic increase conversion of Q4' (35.5%) and Q3,4' (28.6%) in accord with an increased turnover number (k(cat), 1.4×) and catalytic efficiency (k(cat)/K(m), 2.2×) as well as a decrease in K(m) (0.24) for Q4'. Modeling showed that G224T mutation at position 224 may enhance the interaction between G224T and 5-OH and 3-OH on the quercetin backbone of Q4'. PMID:24933681

  9. Crystal structure of a lectin from Canavalia maritima (ConM) in complex with trehalose and maltose reveals relevant mutation in ConA-like lectins.

    PubMed

    Delatorre, Plínio; Rocha, Bruno A M; Gadelha, Carlos A A; Santi-Gadelha, Tatiane; Cajazeiras, João B; Souza, Emmanuel P; Nascimento, Kyria S; Freire, Valder N; Sampaio, Alexandre H; Azevedo, Walter F; Cavada, Benildo S

    2006-06-01

    The crystal structure of Canavalia maritima lectin (ConM) complexed with trehalose and maltose revealed relevant point mutations in ConA-like lectins. ConM with the disaccharides and other ConA-like lectins complexed with carbohydrates demonstrated significant differences in the position of H-bonds. The main difference in the ConM structure is the replacement of Pro202 by Ser202, a residue that promotes the approximation of Tyr12 to the carbohydrate-binding site. The O-6' of the second glucose ring in maltose interacts with Tyr12, while in trehalose the interaction is established by the O-2' and Tyr12, explaining the higher affinity of ConM for disaccharides compared to monosaccharides. PMID:16677825

  10. Structural Analysis of Semi-specific Oligosaccharide Recognition by a Cellulose-binding Protein of Thermotoga maritima Reveals Adaptations for Functional Diversification of the Oligopeptide Periplasmic Binding Protein Fold

    SciTech Connect

    Cuneo, Matthew J.; Beese, Lorena S.; Hellinga, Homme W.; (Duke)

    2010-05-25

    Periplasmic binding proteins (PBPs) constitute a protein superfamily that binds a wide variety of ligands. In prokaryotes, PBPs function as receptors for ATP-binding cassette or tripartite ATP-independent transporters and chemotaxis systems. In many instances, PBPs bind their cognate ligands with exquisite specificity, distinguishing, for example, between sugar epimers or structurally similar anions. By contrast, oligopeptide-binding proteins bind their ligands through interactions with the peptide backbone but do not distinguish between different side chains. The extremophile Thermotoga maritima possesses a remarkable array of carbohydrate-processing metabolic systems, including the hydrolysis of cellulosic polymers. Here, we present the crystal structure of a T. maritima cellobiose-binding protein (tm0031) that is homologous to oligopeptide-binding proteins. T. maritima cellobiose-binding protein binds a variety of lengths of {beta}(1 {yields} 4)-linked glucose oligomers, ranging from two rings (cellobiose) to five (cellopentaose). The structure reveals that binding is semi-specific. The disaccharide at the nonreducing end binds specifically; the other rings are located in a large solvent-filled groove, where the reducing end makes several contacts with the protein, thereby imposing an upper limit of the oligosaccharides that are recognized. Semi-specific recognition, in which a molecular class rather than individual species is selected, provides an efficient solution for the uptake of complex mixtures.

  11. Structural analysis of Canavalia maritima and Canavalia gladiata lectins complexed with different dimannosides: new insights into the understanding of the structure-biological activity relationship in legume lectins.

    PubMed

    Bezerra, Gustavo Arruda; Oliveira, Taianá Maia; Moreno, Frederico Bruno Mendes Batista; de Souza, Emmanuel Prata; da Rocha, Bruno Anderson Matias; Benevides, Raquel Guimarães; Delatorre, Plínio; de Azevedo, Walter Filgueira; Cavada, Benildo Sousa

    2007-11-01

    Plant lectins, especially those purified from species of the Leguminosae family, represent the best studied group of carbohydrate-binding proteins. The legume lectins from Diocleinae subtribe are highly similar proteins that present significant differences in the potency/efficacy of their biological activities. The structural studies of the interactions between lectins and sugars may clarify the origin of the distinct biological activities observed in this high similar class of proteins. In this way, this work presents a crystallographic study of the ConM and CGL (agglutinins from Canavalia maritima and Canavalia gladiata, respectively) in the following complexes: ConM/CGL:Man(alpha1-2)Man(alpha1-O)Me, ConM/CGL:Man(alpha1-3)Man(alpha1-O)Me and ConM/CGL:Man(alpha1-4)Man(alpha1-O)Me, which crystallized in different conditions and space group from the native proteins. The structures were solved by molecular replacement, presenting satisfactory values for R(factor) and R(free). Comparisons between ConM, CGL and ConA (Canavalia ensiformis lectin) binding mode with the dimannosides in subject, presented different interactions patterns, which may account for a structural explanation of the distincts biological properties observed in the lectins of Diocleinae subtribe. PMID:17881248

  12. Structural and biochemical characterization of the ?-N-acetylglucosaminidase from Thermotoga maritima: toward rationalization of mechanistic knowledge in the GH73 family.

    PubMed

    Lipski, Alexandra; Hervé, Mireille; Lombard, Vincent; Nurizzo, Didier; Mengin-Lecreulx, Dominique; Bourne, Yves; Vincent, Florence

    2015-03-01

    Members of the GH73 glycosidase family cleave the ?-1,4-glycosidic bond between the N-acetylglucosaminyl (GlcNAc) and N-acetylmuramyl (MurNAc) moieties in bacterial peptidoglycan. A catalytic mechanism has been proposed for members FlgJ, Auto, AcmA and Atl(WM) and the structural analysis of FlgJ and Auto revealed a conserved ?/? fold reminiscent of the distantly related GH23 lysozyme. Comparison of the active site residues reveals variability in the nature of the catalytic general base suggesting two distinct catalytic mechanisms: an inverting mechanism involving two distant glutamate residues and a substrate-assisted mechanism involving anchimeric assistance by the C2-acetamido group of the GlcNAc moiety. Herein, we present the biochemical characterization and crystal structure of TM0633 from the hyperthermophilic bacterium Thermotoga maritima. TM0633 adopts the ?/? fold of the family and displays ?-N-acetylglucosaminidase activity on intact peptidoglycan sacculi. Site-directed mutagenesis identifies Glu34, Glu65 and Tyr118 as important residues for catalysis. A thorough bioinformatic analysis of the GH73 sequences identified five phylogenetic clusters. TM0633, FlgJ and Auto belong to a group of three clusters that conserve two carboxylate residues involved in a classical inverting acid-base mechanism. Members of the other two clusters lack a conserved catalytic general base supporting a substrate-assisted mechanism. Molecular modeling of representative members from each cluster suggests that variability in length of the ?-hairpin region above the active site confers ligand-binding specificity and modulates the catalytic mechanisms within the GH73 family. PMID:25344445

  13. Crystal structure of Thermotoga maritima TM0439: implications for the mechanism of bacterial GntR transcription regulators with Zn2+-binding FCD domains

    SciTech Connect

    Zheng, Meiying; Cooper, David; Grossoehmerb, Nickolas; Yu, Minmin; Hung, Li-Wei; Cieslik, Murcin; Derewendaro, Urszula; Lesley, Scott; Wilson, Ian; Giedrocb, David; Derewenda, Zygmunt

    2009-06-06

    The GntR superfamily of dimeric transcription factors, with more than 6200 members encoded in bacterial genomes, are characterized by N-terminal winged helix (WH) DNA-binding domains and diverse C-terminal, regulatory domains, which provide a basis for the classification of the constituent families. The largest of these families, FadR, contains nearly 3000 proteins with all a-helical regulatory domains classified into two related Pfam families: FadR{_}C and FCD. Only two crystal structures of the FadR family members, i.e. the E. coli FadR protein and the LldR from C. glutamicum, have been described to date in literature. Here we describe the crystal structure of TM0439, a GntR regulator with an FCD domain, found in the Thermotoga maritima genome. The FCD domain is similar to that of the LldR regulator, and contains a buried metal binding site. Using atomic absorption spectroscopy and Trp fluorescence, we show that the recombinant protein contains bound Ni{sup 2+} ions, but it is able to bind Zn{sup 2+} with K{sub D} < 70 nM . We conclude that Zn{sup 2+} is the likely physiological metal, where it may perform either or both structural and regulatory roles. Finally, we compare the TM0439 structure to two other FadR family structures recently deposited by Structural Genomics consortia. The results call for a revision in the classification of the FadR family of transcription factors.

  14. Post-translational Modification of Ribosomal Proteins: Structural and Functional Characterization of RimO from Thermotoga maritima, a Radical S-adenosylmethionine methylthiotransferase

    SciTech Connect

    Arragain, S.; Latour, J; Forouhar, F; Neely, H; Montelione, G; Hunt, J; Mulliez, E; Fontecave, M; Atta, M; et al.

    2010-01-01

    Post-translational modifications of ribosomal proteins are important for the accuracy of the decoding machinery. A recent in vivo study has shown that the rimO gene is involved in generation of the 3-methylthio derivative of residue Asp-89 in ribosomal protein S12 (Anton, B. P., Saleh, L., Benner, J. S., Raleigh, E. A., Kasif, S., and Roberts, R. J. (2008) Proc. Natl. Acad. Sci. U. S. A. 105, 1826-1831). This reaction is formally identical to that catalyzed by MiaB on the C2 of adenosine 37 near the anticodon of several tRNAs. We present spectroscopic evidence that Thermotoga maritima RimO, like MiaB, contains two [4Fe-4S] centers, one presumably bound to three invariant cysteines in the central radical S-adenosylmethionine (AdoMet) domain and the other to three invariant cysteines in the N-terminal UPF0004 domain. We demonstrate that holo-RimO can specifically methylthiolate the aspartate residue of a 20-mer peptide derived from S12, yielding a mixture of mono- and bismethylthio derivatives. Finally, we present the 2.0 {angstrom} crystal structure of the central radical AdoMet and the C-terminal TRAM (tRNA methyltransferase 2 and MiaB) domains in apo-RimO. Although the core of the open triose-phosphate isomerase (TIM) barrel of the radical AdoMet domain was conserved, RimO showed differences in domain organization compared with other radical AdoMet enzymes. The unusually acidic TRAM domain, likely to bind the basic S12 protein, is located at the distal edge of the radical AdoMet domain. The basic S12 protein substrate is likely to bind RimO through interactions with both the TRAM domain and the concave surface of the incomplete TIM barrel. These biophysical results provide a foundation for understanding the mechanism of methylthioation by radical AdoMet enzymes in the MiaB/RimO family.

  15. Post-translational Modification of Ribosomal Proteins - Structural and Functional Characterization of RimO from Thermotoga Maritima, A Radiacal S-Adenosylmethionine Methylthiotransferase

    SciTech Connect

    Arragain, S.; Garcia-Serres, R; Blondin, G; Douki, T; Clemancey, M; Latour, J; Forouhar, F; Neely, H; Montelione, G; et. al.

    2010-01-01

    Post-translational modifications of ribosomal proteins are important for the accuracy of the decoding machinery. A recent in vivo study has shown that the rimO gene is involved in generation of the 3-methylthio derivative of residue Asp-89 in ribosomal protein S12 (Anton, B. P., Saleh, L., Benner, J. S., Raleigh, E. A., Kasif, S., and Roberts, R. J. (2008) Proc. Natl. Acad. Sci. U. S. A. 105, 1826-1831). This reaction is formally identical to that catalyzed by MiaB on the C2 of adenosine 37 near the anticodon of several tRNAs. We present spectroscopic evidence that Thermotoga maritima RimO, like MiaB, contains two [4Fe-4S] centers, one presumably bound to three invariant cysteines in the central radical S-adenosylmethionine (AdoMet) domain and the other to three invariant cysteines in the N-terminal UPF0004 domain. We demonstrate that holo-RimO can specifically methylthiolate the aspartate residue of a 20-mer peptide derived from S12, yielding a mixture of mono- and bismethylthio derivatives. Finally, we present the 2.0 {angstrom} crystal structure of the central radical AdoMet and the C-terminal TRAM (tRNA methyltransferase 2 and MiaB) domains in apo-RimO. Although the core of the open triose-phosphate isomerase (TIM) barrel of the radical AdoMet domain was conserved, RimO showed differences in domain organization compared with other radical AdoMet enzymes. The unusually acidic TRAM domain, likely to bind the basic S12 protein, is located at the distal edge of the radical AdoMet domain. The basic S12 protein substrate is likely to bind RimO through interactions with both the TRAM domain and the concave surface of the incomplete TIM barrel. These biophysical results provide a foundation for understanding the mechanism of methylthioation by radical AdoMet enzymes in the MiaB/RimO family.

  16. Thermotoga maritima ribonuclease III. Characterization of thermostable biochemical behavior, and analysis of conserved base-pairs that function as reactivity epitopes for the Thermotoga 23S ribosomal RNA precursor.†

    PubMed Central

    Nathania, Lilian; Nicholson, Allen W.

    2010-01-01

    The cleavage of double-stranded(ds) RNA by ribonuclease III is a conserved early step in bacterial rRNA maturation. Studies on the mechanism of dsRNA cleavage by RNase III have focused mainly on the enzymes from mesophiles such as Escherichia coli. In contrast, neither the catalytic properties of extremophile RNases III, nor the structures and reactivities of their cognate substrates has been described. The biochemical behavior of RNase III of the hyperthermophilic Bacterium Thermotoga maritima was analyzed using purified recombinant enzyme. T. maritima(Tm) RNase III catalytic activity exhibits a broad optimal temperature range of ?40-70°C, with significant activity at 95°C. Tm-RNase III cleavage of substrate is optimally supported by Mg2+ at ?1 mM concentrations. Mn2+, Co2+ and Ni2+ also support activity, but with reduced efficiencies. The enzyme functions optimally at pH 8, and ?50-80 mM salt concentrations. Small RNA hairpins that incorporate the 16S and 23S pre-rRNA stem sequences are efficiently cleaved by Tm-RNase III at sites that are consistent with production in vivo of the immediate precursors to the mature rRNAs. Analysis of pre-23S substrate variants reveals a dependence of reactivity on the base-pair (bp) sequence in the proximal box (pb), a site of protein contact that functions as a positive recognition determinant for E. coli(Ec) RNase III substrates. The dependence of reactivity on the pb sequence is similar to that observed with Ec-RNase III substrates. In fact, Tm-RNase III cleaves an Ec-RNase III substrate with identical specificity, and is inhibited by antideterminant bp that also inhibit Ec-RNase III. These results indicate the conservation, across a broad phylogenetic distance, of positive and negative determinants of reactivity of bacterial RNase III substrates. PMID:20677811

  17. International Association for Ecology Genetic and Environmental Effects on Wing Polymorphisms in Two Tropical Earwigs

    E-print Network

    Bermingham, Eldredge

    of wing polymorphisms depends on knowledge of the adaptive values of the differ- ent morphs (AndersonInternational Association for Ecology Genetic and Environmental Effects on Wing Polymorphisms:253-255 (JCCOlOglU ? Springer-Verlag 1987 Genetic and environmental effects on wing polymorphisms in two tropical

  18. 75 FR 35990 - Endangered and Threatened Wildlife and Plants; Listing the Flying Earwig Hawaiian Damselfly and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-24

    ...many stream channels completely dry (Takasaki et al. 1969, pp...designed to do) during times of drier weather or drought. The Pacific Hawaiian...all stream water during times of drier weather or drought. Therefore, the...

  19. New earwigs in mid-Cretaceous amber from Myanmar (Dermaptera, Neodermaptera)

    E-print Network

    Engel, Michael S.

    2011-09-24

    subfamily, Astreptolabidinae subfam. n., and differs from other protodermapterans in the structure of the head, pronotum, tegmina, and cercal forceps. Tytthodiplatys mecynocercus gen. et sp. n. is a distinctive form of first-instar nymph of the Diplatyidae...

  20. Magnetic imaging of a submerged Roman harbour, Caesarea Maritima, Israel

    NASA Astrophysics Data System (ADS)

    Boyce, J. I.; Reinhardt, E. G.; Raban, A.; Pozza, M. R.

    2003-04-01

    The harbour built by King Herod's engineers at Caesarea represented a major advance in Roman harbour construction that incorporated the use of large (390 m^3), form-filled hydraulic concrete blocks to build an extensive foundation for the harbour moles and breakwater barriers. Marine geophysical surveys were recently conducted across the submerged harbour in an attempt to map the configuration of the buried concrete foundation. A total of 107 line km of high-resolution marine magnetic surveys (nominal 15 m line separations) and bathymetry data were acquired over a 1 km^2 area of the submerged harbour using an Overhauser marine magnetometer, integrated DGPS and single-beam (200 KHz) echosounder. The feasibility of magnetic detection of the concrete was established before the survey by magnetic susceptibility testing of concrete core samples. All concrete samples contained appreciable amounts of fe-oxide-rich volcanic ash ('pozzolana') and showed uniformly high susceptibility values (k > 10^-^4 cgs) when compared to harbour bottom sediments and building stones (k < 10 ^-^6 cgs). Magnetic surveys of the harbour identify a localized increase in magnetic intensity (ca. 1-7 nT) that is attributed to the presence of hydraulic concrete within the buried harbour structure. The mapped anomaly patterns are distinctly rectilinear, indicating that the concrete foundation was laid out in header fashion in dominantly N-S and W-E trending segments. Magnetic lows identify 'cells' within the concrete foundation framework that were likely filled with harbour sediments prior to construction of the harbour moles and quays.

  1. Necromenic life style of Histiostoma polypori (Acari: Histiostomatidae).

    PubMed

    Wirth, S

    2009-12-01

    Histiostoma polypori (Histiostomatidae, Astigmata) is associated with the earwig Forficula auricularia, which has an interesting brood behavior: the adult earwig female cares for her eggs and stays with the N2 and N3 nymphs in the nest. Deutonymphs of H. polypori only leave the female earwig to develop on dead earwig N2 and N3 nymphs. The newly molted deutonymphs attach to live earwig N3 nymphs. The earwig's cleaning behavior displaces the deutonymphs to the exuvial suture, around the area between cephalon and prothorax. From there, deutonymphs switch from one earwig stage to the following, always occupying that region. Histiostoma polypori obviously has a necromenic life style, that is, it ascends a carrier organism and develops on the carrier's cadavers. Necromeny within the Histiostomatidae presumably derived at least twice convergently from phoretic transport. PMID:19697142

  2. Spatial genetic structure in Beta vulgaris subsp. maritima and Beta macrocarpa reveals the effect of contrasting

    E-print Network

    , Universite des Sciences et Technologies de Lille ­ Lille 1, Villeneuve d'Ascq Cedex F-59655, France 2 UMR 8198, B^atiment SN2, Universite des Sciences et Technologies de Lille ­ Lille 1, Villeneuve d'Ascq Cedex, F-59655, France. Tel: +33 (0)3 20 33 63 97; Fax: +33 (0) 3 20 43 69 79; E-mail: jean-francois.arnaud@univ-lille

  3. Germ cells of the centipede Strigamia maritima are specified early in embryonic development

    E-print Network

    Green, Jack E.; Akam, Michael

    2014-06-12

    variable with respect to segment addition, implying that the two processes are not tightly correlated between embryos. Progression of hindgut invagination is a more reliable staging marker for this process. Abbreviations: lbs¼ leg-bearing segments; stg... is not observed inside the oocyte nucleus. In the grasshopper Schistocerca americana, it has been sug- gested that localization of maternal Hunchback protein in the germinal vesicle might act as a mechanism for localizing the protein in the early embryo (Patel et...

  4. Solution NMR structure of the cold-shock protein from the hyperthermophilic bacterium Thermotoga maritima

    Microsoft Academic Search

    Werner Kremer; Benjamin Schuler; Stefan Harrieder; Matthias Geyer; Wolfram Gronwald; Christine Welker; Rainer Jaenicke; Hans R. Kalbitzer

    Cold-shock proteins (Csps) are a subgroup of the cold- induced proteins preferentially expressed in bacteria and other organisms on reduction of the growth temperature below the physiological temperature. They are related to the cold-shock domain found in eukaryotes and are some of the most conserved proteins known. Their exact function is still not known, but translational regulation, possibly via RNA

  5. Formylglycinamide Ribonucleotide Amidotransferase from Thermotoga maritima: Structural Insights into Complex Formation

    E-print Network

    Morar, Mariya

    In the fourth step of the purine biosynthetic pathway, formyl glycinamide ribonucleotide (FGAR) amidotransferase, also known as PurL, catalyzes the conversion of FGAR, ATP, and glutamine to formyl glycinamidine ribonucleotide ...

  6. Restoration Potential of Ruppia maritima and Potamogeton perfoliatus by Seed in the Mid-Chesapeake Bay

    Microsoft Academic Search

    Steve Ailstock; Deborah Shafer

    DEFINITION: Reproductive potential is a measure of an organism's capacity to produce offspring. In plants, total reproductive potential is a combination of vegetative or clonal offspring and those resulting from seeds. However, because seeds are produced in quantity and are the propagules responsible for distribution of new ecotypes to new habitats, they are the most significant contributor to the reproductive

  7. Starch grain morphology of the seagrasses Halodule wrightii, Ruppia maritima, Syringodium filiforme, and Thalassia testudinum

    Microsoft Academic Search

    Stephanie Peek; Mark T. Clementz

    Starch grains are a ubiquitous component of plants that have been used in tandem with phytoliths, pollen, and macrofossils to reconstruct past floral diversity. This tool has yet to be fully explored for aquatic plants, specifically seagrasses, which lack phytoliths and are rarely preserved as macrofossils or pollen. If starch grains in seagrasses are morphologically distinct, this method has the

  8. Selenium uptake by larval Chironomus decorus from a Ruppia maritima -based benthic\\/detrital substrate

    Microsoft Academic Search

    J. Alaimo; R. S. Ogle; A. W. Knight

    1994-01-01

    Elevated levels of selenium have led to the contamination of several aquatic ecosystems. Much of the selenium contamination has resulted from agricultural irrigation and drainage of seleniferous soils. Disposal of selenium contaminated drainwater in evaporation ponds has led to selenium bioaccumulation and toxicity in waterfowl and shorebirds using these ponds. Studies have demonstrated that it is a seleno-amino acid that

  9. Secondary production within a seagrass bed ( Zostera marina and Ruppia maritima ) in lower Chesapeake Bay

    Microsoft Academic Search

    Thomas J. Fredette; Robert J. Diaz

    1990-01-01

    Monthly sampling of a 140-ha seagrass bed in the lower Chesapeake Bay, Virginia, revealed that 13 numerically and trophically\\u000a important species, representing about 20% of the total community densities over the year-long study period, accounted for\\u000a the production of ?42 g dry wt m?2 yr?1. This estimate is likely conservative due to our assumptions on voltinism and fixed size at

  10. Outstanding appearance of Ruppia maritima along Baja California Sur, México and its influence in trophic networks

    Microsoft Academic Search

    Jorge Lopez-Calderon; Rafael Riosmena-Rodríguez; Juan M. Rodríguez-Baron; Javier Carrión-Cortez; Jorge Torre; Alf Meling-López; Gustavo Hinojosa-Arango; Gustavo Hernández-Carmona; Jaqueline García-Hernández

    2010-01-01

    Human impact and global warming are driving major modifications to the world’s ecosystems, the coastal zone being one of the\\u000a most damaged. Seagrass meadows constitute coastal communities that have experienced great losses worldwide. The dominant seagrass\\u000a in the meadows of the Pacific coast of North America is Zostera marina. There is evidence that Z. marina has been replaced in some

  11. Genetic structure and gene flow in Beta vulgaris subspecies maritima along the Atlantic coast of France

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Locating and quantifying genetic variation within crop wild relatives is an ongoing activity of gene banks tasked with ex situ conservation. Without detailed information about the population genetics of a species geography often serves as a reasonable proxy for differentiation. With this in mind, ...

  12. Uniformity of the nuclear and chloroplast genomes of Spartina maritima (Poaceae), a salt-marsh

    E-print Network

    Alvarez, Nadir

    ; 2 Institut Me´diterrane´en d'Ecologie et de Pale´oe´cologie, University of Aix-Marseille III. Ba DNA markers: inter-simple sequence poly- morphism (ISSR), randomly amplified polymorphic DNA (RAPD), inter-retrotransposon amplified polymorphism (IRAP), and PCR-RFLP of a 5 kb long portion of chloroplast

  13. Biology and ecology of the earwig, Doru taeniata (Dohrn) and evaluation as a predator of Spodoptera frugiperda attacking corn and sorghum in Honduras 

    E-print Network

    Jones, Robert Wallace

    1985-01-01

    . D. taeniata is an omnivore and capable of developing and reproducing on both plant pollen xv d 1 p d pt gg (~S * 1 11 (Dl' ' )) ' h* 1 b t y. D. taeniate develops through four instars and reaches imago in approximately 30 days. Immatures...' ft tp't'ddf S. ~f1d in corn and sorghum in Honduras in 1982 . . . . . . 109 Table LIST OF TABLES (cont. ) Page 15 ftlp tpt' 'fS. ~ft d1 11 td in corn and sorghum plots 110 16 W klyp tp t' 'fS. ~f' d 1 11 td in monoculture corn...

  14. A Bacterial Genetic Screen Identifies Functional Coding Sequences of the Insect mariner Transposable Element Famar1 Amplified From the Genome of the Earwig, Forficula auricularia

    Microsoft Academic Search

    Elizabeth G. Barry; David J. Witherspoon; David J. Lampe

    2004-01-01

    Transposons of the mariner family are widespread in animal genomes and have apparently infected them by horizontal transfer. Most species carry only old defective copies of particular mariner transposons that have diverged greatly from their active horizontally transferred ancestor, while a few contain young, very similar, and active copies. We report here the use of a whole-genome screen in bacteria

  15. Atlas y Libro Rojo de la Flora Vascular Amenazada de Espaa LEGUMINOSAE

    E-print Network

    Herrera, Carlos M.

    , Polygala rupestris, Umbilicus heylandianus. En la base de los acantilados, junto a Lobularia maritima y acantilados calcáreos, muchos de ellos extraplomados. Allí convive con Campanula mollis, Lavatera maritima

  16. Cytotoxic and Antimicrobial Constituents of the Bark of Diospyros maritima Collected in Two Geographical Locations in Indonesia

    E-print Network

    Falkinham, Joseph

    for Collaborative Research in the Pharmaceutical Sciences and Department of Medicinal Chemistry and Pharmacognosy Carolina 27709-2194, Research Center for Chemistry, Indonesian Institute of Science, Serpong, 15310 Tangerang, Indonesia, Herbarium Bogoriense, Research and Development Center for Biology, Indonesian

  17. The embryoid development of Strigamia maritima and its bearing on post-embryonic segmentation of geophilomorph centipedes

    E-print Network

    Brena, Carlo

    2014-08-13

    hatch after approximately 48 days at 13°C, a temperature close to the average June temperature at the field site for this population [6]. The rupture of the chorion is probably promoted by internal pressure and by movements of the embryo which... on my analysis at 13°C on single specimens (n = 23) and whole clutches as described in M&M. The timing of de- velopment is probably in part affected by the culturing conditions, in particular if one considers that my speci- mens have been constantly...

  18. Morphogenetic lability of the Ruppia maritima (Ruppiaceae, Alismatales) reproductive organs: From two lateral flowers to a terminal flower

    Microsoft Academic Search

    I. E. Lock; D. D. Sokoloff; M. V. Remizowa

    2011-01-01

    Flowers of Ruppia are usually arranged into an open two-flowered spike, but sometimes two lateral flowers are congenitally united with each\\u000a other forming a terminal flower-like structure. This deviation from the morphogenesis of reproductive structures typical of\\u000a Ruppia resembles those described in well-studied mutants of the model organisms of developmental genetics, such as Arabidopsis and Antirrhinum. A study of Ruppia

  19. Effect of ingestion by five avian dispersers on the retention time, retrieval and germination of Ruppia maritima seeds

    Microsoft Academic Search

    I. Charalambidou; L. Santamaría; O. Langevoord

    2003-01-01

    1. Vertebrates are important seed dispersers for many plants, particularly those inhabiting naturally fragmented habitats such as lakes and wetlands. Such dispersal often takes place through the transport of ingested seeds (endozoochory). 2. Endozoochorous passage of seeds is likely to vary among both disperser and dispersed species. We hypothesized that seed retention time and survival of gut passage varies among

  20. BULLETIN OF MARINE SCIENCE, 77(3): 453458, 2005 453Bulletin of Marine Science

    E-print Network

    Durako, Michael J.

    ON SEED GERMINATION IN RUPPIA MARITIMA FROM FLORIDA BAY A. E. Kahn and M. J. Durako Ruppia maritima L (Lapointe et al., 2002). METHODS SEED COLLECTION.--Ruppia maritima seeds were collected in Garfield Bight. (widgeon grass) is one of six species of submerged angio- sperms found in Florida Bay. Although R. maritima

  1. Bell Pettigrew Museum of Natural History

    E-print Network

    Brierley, Andrew

    -dwelling herbivores and carnivores (e.g. many beetles and ants), scavengers (e.g. earwigs, houseflies and cockroaches.g. black-fly larvae) and benthic scavengers (e.g. caddis , and mayfly nymphs). Classification within

  2. Effects of seed ingestion and herbivory by waterfowl on seedling establishment: a field experiment with wigeongrass Ruppia maritima in Doñana, south-west Spain

    Microsoft Academic Search

    Jordi Figuerola; Andy J. Green

    2004-01-01

    The ingestion of seeds by vertebrates usually affects the viability and\\/or germination rate of seeds. Increases in germination rate following passage through the vertebrate gut have often been assumed to be favourable for seedling survival and plant fitness, but this assumption has never been tested experimentally. Given that numbers of herbivorous waterfowl are higher in winter in Mediterranean wetlands, herbivory

  3. An anterior medial cell population with an apical-organ-like transcriptional profile that pioneers the central nervous system in the centipede Strigamia maritima

    E-print Network

    Hunnekuhl, Vera S.; Akam, Michael

    2014-01-01

     anterior  head  (figure  1G).    4    5   The  AMR  becomes  positioned  between  the  two  halves  of  the  pre-­antennal  region  by  6   a  morphogenetic  re-­arrangement  of  the  anterior  head...  Drosophila  19   caupolican  and  araucan)  is  expressed  within  the  AMR  but  only  dorsally  in  the  20   cells  overlying  the  medial  neuronal  cell  cluster  (figure  4F,  G).  Both  rx  and...

  4. The tsunami of 13 December A.D. 115 and the destruction of Herod the Great's harbor at Caesarea Maritima, Israel

    NASA Astrophysics Data System (ADS)

    Reinhardt, Eduard G.; Goodman, Beverly N.; Boyce, Joe I.; Lopez, Gloria; van Hengstum, Peter; Rink, W. Jack; Mart, Yossi; Raban, Avner

    2006-12-01

    Underwater geoarchaeological excavations on the shallow shelf (˜10 m depth) at Caesarea, Israel, have documented a tsunami that struck and damaged the ancient harbor at Caesarea. Talmudic sources record a tsunami that struck on 13 December A.D. 115, impacting Caesarea and Yavne. The tsunami was probably triggered by an earthquake that destroyed Antioch, and was generated somewhere on the Cyprian Arc fault system. The tsunami deposit consisted of an ˜0.5-m-thick bed of reverse-graded shells, coarse sand, pebbles, and pottery deposited over a large area outside of the harbor. The lower portion of the deposit was composed of angular shell fragments, and the upper portion of whole convex-up Glycymeris spp. shells. The sequence records tsunami downcutting (˜1 m) into shelf sands, with the return flow sorting and depositing angular shell fragments followed by oriented whole shells. Radiocarbon dating of articulated Glycymeris shells, and optically stimulated luminescence (OSL) dates, constrain the age of the deposit to between the first century B.C. and the second century A.D., and point to the tsunami of A.D. 115 as the most likely candidate for the event, and the probable cause of the harbor destruction.

  5. Interactions between indole-3-acetic acid (IAA) with a lectin from Canavalia maritima seeds reveal a new function for lectins in plant physiology.

    PubMed

    Delatorre, Plinio; Silva-Filho, José Caetano; Rocha, Bruno Anderson Matias; Santi-Gadelha, Tatiane; da Nóbrega, Raphael Batista; Gadelha, Carlos Alberto Almeida; do Nascimento, Kyria Santiago; Nagano, Celso Shiniti; Sampaio, Alexandre Holanda; Cavada, Benildo Sousa

    2013-09-01

    Indole-3-acetic acid (IAA) bound is considered a storage molecule and is inactive. However, some studies have proposed an additional possible regulatory mechanism based on the ability of lectins to form complexes with IAA. We report the first crystal structure of ConM in complex with IAA at 2.15 ? resolution. Based on a tetrameric model of the complex, we hypothesize how the lectin controls the availability of IAA during the early seedling stages, indicating a possible new physiological role for these proteins. A free indole group is also bound to the protein. The ConM interaction with different forms of IAA is a strategy to render the phytohormone unavailable to the cell. Thus, this new physiological role proposed for legume lectins might be a novel mechanism by which IAA levels are decreased in addition to the destruction and formation of new complexes in the later stages of seed germination. PMID:23727478

  6. Structural analysis of Canavalia maritima and Canavalia gladiata lectins complexed with different dimannosides: New insights into the understanding of the structure–biological activity relationship in legume lectins

    Microsoft Academic Search

    Gustavo Arruda Bezerra; Taianá Maia Oliveira; Frederico Bruno Mendes Batista Moreno; Emmanuel Prata de Souza; Bruno Anderson Matias da Rocha; Raquel Guimarães Benevides; Plínio Delatorre; Walter Filgueira de Azevedo; Benildo Sousa Cavada

    2007-01-01

    Plant lectins, especially those purified from species of the Leguminosae family, represent the best studied group of carbohydrate-binding proteins. The legume lectins from Diocleinae subtribe are highly similar proteins that present significant differences in the potency\\/efficacy of their biological activities. The structural studies of the interactions between lectins and sugars may clarify the origin of the distinct biological activities observed

  7. Detection of intermediates in the oxidative half-reaction of the FAD-dependent thymidylate synthase from Thermotoga maritima: carbon transfer without covalent pyrimidine activation.

    PubMed

    Conrad, John A; Ortiz-Maldonado, Mariliz; Hoppe, Samuel W; Palfey, Bruce A

    2014-08-19

    Thymidylate, a vital DNA precursor, is synthesized by thymidylate synthases (TSs). A second class of TSs, encoded by the thyX gene, is found in bacteria and a few other microbes and is especially widespread in anaerobes. TS encoded by thyX requires a flavin adenine dinucleotide prosthetic group for activity. In the oxidative half-reaction, the reduced flavin is oxidized by 2'-deoxyuridine 5'-monophosphate (dUMP) and (6R)-N5,N10-methylene-5,6,7,8-tetrahydrofolate (CH2THF), synthesizing 2'-deoxythymidine 5'-monophosphate (dTMP). dTMP synthesis is a complex process, requiring the enzyme to promote carbon transfer, probably by increasing the nucleophilicity of dUMP and the electrophilicity of CH2THF, and reduction of the transferred carbon. The mechanism of the oxidative half-reaction was investigated by transient kinetics. Two intermediates were detected, the first by a change in the flavin absorbance spectrum in stopped-flow experiments and the second by the transient disappearance of deoxynucleotide in acid quenching experiments. The effects of substrate analogues and the behavior of mutated enzymes on these reactions lead to the conclusion that activation of dUMP does not occur through a Michael-like addition, the mechanism for the activation analogous with that of the flavin-independent TS. Rather, we propose that the nucleophilicity of dUMP is enhanced by electrostatic polarization upon binding to the active site. This conclusion rationalizes many of our observations, for instance, the markedly slower reactions when two arginine residues that hydrogen bond with the uracil moiety of dUMP were mutated to alanine. The activation of dUMP by polarization is consistent with the majority of the published data on ThyX and provides a testable mechanistic hypothesis. PMID:25068636

  8. An anterior medial cell population with an apical-organ-like transcriptional profile that pioneers the central nervous system in the centipede Strigamia maritima.

    PubMed

    Hunnekuhl, Vera S; Akam, Michael

    2014-12-01

    The apical plate of primary marine larvae is characterized by a common set of transcription factors comprising six3, rx, hbn, nk2.1 and FoxQ2. It harbours the apical organ, a neural and ciliary structure with neurosecretory properties. Recent studies in lophotrochozoans have found that apical organ cells form the anterior tip of the developing central nervous system. We identify an anterior medial tissue in the embryonic centipede head that shares the transcriptional profile of the apical plate of marine larvae, including nested domains of FoxQ2 and six3 expression. This domain gives rise to an anterior medial population of neural precursors distinct from those arising within the segmental neuroectoderm. These medial cells do not express achaete scute homologue in proneural clusters, but express collier, a marker for post mitotic cells committed to a neural fate, while they are still situated in the surface ectodermal layer. They then sink under the surface to form a compact cell cluster. Once internalized these cells extend axons that pioneer the primary axonal scaffold of the central nervous system. The same cells express phc2, a neural specific prohormone convertase, which suggests that they form an early active neurosecretory centre. Some also express markers of hypothalamic neurons, including otp, vtn and vax1. These medial neurosecretory cells of the centipede are distinct from those of the pars intercerebralis, the anterior neurosecretory part of the insect brain. The pars intercerebralis derives from vsx positive placodal-like invagination sites. In the centipede, vsx expressing invaginating ectoderm is situated bilaterally adjacent to the medial pioneer cell population. Hence the pars intercerebralis is present in both insect and centipede brains, whereas no prominent anterior medial cluster of pioneer neurons is present in insects. These observations suggest that the arthropod brain retained ancestrally an anterior medial population of neurosecretory cells homologous to those of the apical plate in other invertebrate phyla, but that this cell population has been lost or greatly reduced in insects. PMID:25263198

  9. FAJA DOS CUBRES, SAO JORGE: A CASE FOR COASTAL CONSERVATION AND THE FIRST RECORD OF Ruppia maritima Linnaeus (MONOCOTYLEDONES; RUPPIACEAE) FROM THE ACORES

    Microsoft Academic Search

    Brian Morton; J. C. Britton; A. M. Frias Martins

    Fajl dos Cubres on the north shore of the island of Slo Jorge, Aqores, comprises a shallow (=2 m) lagoon contained within a coastal platform and protected from the sea by a boulder rampart. Hitherto considered lacus- trine, it is here shown that the lagoon is influenced primarily by fresh- water to the southeast, but is also influenced by seawater

  10. Identification and mapping of RAPD and RFLP markers linked to a fertility restorer gene for a new source of cytoplasmic male sterility in Beta vulgaris ssp. maritima

    Microsoft Academic Search

    V. Laporte; D. Merdinoglu; P. Saumitou-Laprade; G. Butterlin; P. Vernet; J. Cuguen

    1998-01-01

    The present study shows that the recently described mitochondrial H haplotype is associated with cytoplasmic male-sterility\\u000a (CMS). This new source of CMS appears to be different from the mitotype E-associated CMS most frequently found in natural\\u000a populations. A mitotype H progeny with a sexual phenotype segregation was used to identify a gene restoring male fertility\\u000a (R1H?). Using bulk segregant analysis

  11. Effects of Nutrient Additions on Three Coastal Salt Marsh Plants Found in Sunset Cove, Texas 

    E-print Network

    Rulon, Leslie

    2012-02-14

    Galveston Bay, Texas are limited. In this study, the effects of repeated nutrient additions in monospecific plots of Spartina alterniflora, Batis maritima¸ and Salicornia virginica as well as mixed plots of B. maritima and S. virginica were studied over 15...

  12. Saltwater Incursion into Micro Tidal Wetlands: Case Studies from Matagorda, Texas and Humacao, Puerto Rico 

    E-print Network

    Colon, Ricardo J.

    2013-08-27

    maritima and Halodule wrightii, low marsh dominated by Spartina alterniflora, mid marsh dominated by Salicornia virginica and Batis maritima, unvegetated salt flat with some Monanthocloe littoralis around the edges, and high marsh dominated by Spartina...

  13. Cellular Automata Modelling of Seagrass in the Orbetello Lagoon

    E-print Network

    of wigeongrass (Ruppia maritima) meadows in the Orbetello lagoon, in central Italy, where the control, and this paper presents a further refinement, with the dynamics of wigeongrass (Ruppia maritima) including

  14. Approved for public release; distribution is unlimited. ERDC/TN SAV-11-1

    E-print Network

    US Army Corps of Engineers

    the seed reproductive potential of two species of submersed aquatic angiosperms, Ruppia maritima (widgeon-bearing plant stems. #12;ERDC/TN SAV-11-1 May 2011 2 seed-bearing stems of Ruppia maritima (widgeon grass

  15. Underwater survey and excavation at the ancient port of Gravisca, Italy 

    E-print Network

    Shuey, Elizabeth Bostwick

    1978-01-01

    ) 13. 57 E. E. SI, R01?. :. 'S~d'6R61', (Ld 1969) 105; 187 note 184. Gravisca was founded as part of the coloniaa maritimae as a coastal strongho' d ' o protect Rome. On thd. purpose of the coloniae maritimae see Salmon, "The Coloniae Maritimae, u...

  16. MARINE ECOLOGY PROGRESS SERIES Mar Ecol Prog Ser

    E-print Network

    La Peyre, Megan

    -Research 2006 · www.int-res.com*Corresponding author. Email: mlapey@lsu.edu Nekton use of Ruppia maritima in shallow water brackish marsh ponds, which contained monospecific beds of Ruppia maritima L. Three habitat WORDS: Brackish marsh · Nekton habitat · Ruppia maritima L. · Louisiana · Submerged aquatic vegetation

  17. Biological Control 40 (2007) 8088 www.elsevier.com/locate/ybcon

    E-print Network

    Hoddle, Mark S.

    2007-01-01

    -water, Lobularia maritima, Fagopyrum esculentum and water only) on the longevity, fecundity, and progeny Wtness; Lobularia maritima; Longevity; Mymaridae 1. Introduction In California, the egg parasitoid Gonatocerus longer) when fed C. hesperidum honeydew, honey-water, L. maritima and F. esculentum compared with water

  18. Spring staging in Brent Geese Branta bernicla : feeding constraints and the impact of diet on the accumulation of body reserves

    Microsoft Academic Search

    Jouke Prop; Charlotte Deerenberg

    1991-01-01

    The diet composition of Brent Geese Branta bernicla on a salt-marsh was quantified. Puccinellia maritima was the principal food species, while Plantago maritima and Triglochin maritima were less commonly taken. Festuca rubra only acted as a substitute for Puccinellia when production of the latter species dropped. The metabolizable energy of the food plants ranged from 5 to 11 kJ·g-1. By

  19. The effect of cattle grazing on the abundance and distribution of selected macroinvertebrates in west Galveston Island salt marshes 

    E-print Network

    Martin, Jennifer Lynn

    2004-09-30

    flooding, such as Salicornia virginica and Batis maritima, with the density of S. alterniflora decreasing steadily with increasing elevation (White et al. 1978, Mendelssohn 1979). Although Salicornia virginica and Batis maritima occur at middle to high... bigelovii and Batis maritima and adjoins a non-vegetated high tidal flat. 4 OBJECTIVES 1. To determine the effects of cattle activity on height, percent cover, and stem density of salt marsh vegetation (Spartina alterniflora, Salicornia virginica...

  20. Investigations into the effects of environmental and physical variables on the growth of natural and transplanted populations of Ruppia maritima L. s.l. in the Galveston Bay System, Texas

    E-print Network

    Schubert, William James

    2002-01-01

    in Brazoria County, Texas (Latitude 29' 03' 23. 80" Longitude 95' 13' 23. 08"). The site was formed as a goose eatout in which the elevation of an intermediate marsh (comprised primarily of Scirpus americanus) was lowered, allowing periodic tidal inundation...

  1. Restoration of resaca wetlands and associated wet prairie habitats at Palo Alto Battlefield National Historic Site

    E-print Network

    Margo, Michael Ray

    2006-08-16

    include Borrichia frutescens, Suaeda spp., Salicornia virginica, Batis maritima, Limonium nashii, and Monanthochloe littoralis. Several introduced grasses include Dichanthium annulatum, Dichanthium, aristatum, Pennisetum ciliare, Urochloa maxima...

  2. Restoration of resaca wetlands and associated wet prairie habitats at Palo Alto Battlefield National Historic Site 

    E-print Network

    Margo, Michael Ray

    2006-08-16

    include Borrichia frutescens, Suaeda spp., Salicornia virginica, Batis maritima, Limonium nashii, and Monanthochloe littoralis. Several introduced grasses include Dichanthium annulatum, Dichanthium, aristatum, Pennisetum ciliare, Urochloa maxima...

  3. ECOLOGICAL RESTORATION 23:4 DECEMBER 2005 235 Ecological Restoration, Vol. 23, No. 4, 2005 ISSN 1522-4740 E-ISSN 1543-4079

    E-print Network

    (Myriophyllum spi- catum), widgeon grass (Ruppia maritima), wild celery (Vallisneria americana), and coontail management, Ruppia mar- itima, submerged aquatic vegetation, coastal ecosystems, waterfowl management #12

  4. BULLETIN OF MARINE SCIENCE, 72(1): 3761, 2003 NEKTON USE OF DIFFERENT HABITAT TYPES IN SEAGRASS

    E-print Network

    , and turtlegrass Thalassia testudinum and second- arily clovergrass Halophila engelmannii and wigeongrass Ruppia maritima. Seagrass meadows are typically dominated by one species determined by water clarity, depth

  5. ORIGINAL ARTICLE doi:10.1111/j.1558-5646.2008.00563.x

    E-print Network

    Moczek, Armin P.

    below the threshold. We compare two polyphenic species; the dung beetle Onthophagus taurus, whose not evolve independently of one another. KEY WORDS: Alternative tactics, dimorphism, earwig, horned beetles beetles, have concentrated on a developmental model in which a cue, such as body size, leads

  6. Family, Home & Garden Education Center practical solutions to everyday questions

    E-print Network

    New Hampshire, University of

    to determine the sex of an individual (see figure b). Earwigs use forceps as a defense organ and an aid they may damage dahlias, zinnias, butterfly bush, lettuce, strawberry, celery, potatoes and seedling beans, national origin, race, religion, sex, sexual orientation, or veterans status. Control Non-chemical control

  7. The arbuscular mycorrhizal fungus Glomus geosporum in European saline, sodic and gypsum soils

    Microsoft Academic Search

    Melanie Landwehr; Ulrich Hildebrandt; Petra Wilde; Kerstin Nawrath; Tibor Tóth; Borbála Biró; Hermann Bothe

    2002-01-01

    Plants of saline and sodic soils of the Hungarian steppe and of gypsum rock in the German Harz mountains, thus soils of high ionic strength and electric conductivity, were examined for their colonization by arbuscular mycorrhizal fungi (AMF). Roots of several plants of the saline and sodic soils such as Artemisia maritima, Aster tripolium or Plantago maritima are strongly colonized

  8. Raster based coastal marsh classification within the Galveston Bay ecosystem, Texas 

    E-print Network

    Edwards, Aron Shaun

    2009-05-15

    ), and cattail (Typha sp.) compose the low marsh, marshhay cordgrass (Spartina patens), saltwort (Batis maritima), bushy sea ox-eye daisy (Borrichia frutescens), perennial glasswort (Salicornia virginica), annual seepweed (Suaeda linearis), needlerush (Juncus... can be used to distinguish individual vegetation communities such as Spartina alterniflora, Scirpus robustus, 7 and Typha domingensis, which compose the low marsh Spartina patens, Batis maritima, Borrichia frutescens, Salicornia virginica...

  9. Physicochemical, functional and cooking properties of under explored legumes, Canavalia of the southwest coast of India

    Microsoft Academic Search

    S. Seena; K. R. Sridhar

    2005-01-01

    Nutritionally potential under explored wild legumes viz., Canavalia cathartica and Canavalia maritima are widely distributed in mangroves and sand dunes, respectively, in Southwest coast of India. Physicochemical, functional and cooking properties of dried seeds of these legumes have been evaluated. Seeds and cotyledons of C. cathartica are larger and possessing higher hydration and swelling capacity than that of C. maritima

  10. Tropical seagrass species tolerance to hypersalinity stress M.S. Koch a,*, S.A. Schopmeyer a

    E-print Network

    Koch-Rose, Marguerite

    ) and Halodule wrightii (65 psu) eliciting a slightly higher salinity threshold than Ruppia maritima (55 psu: Salinity; Hypersalinity; Seagrass; Thalassia testudinum Banks ex Konig; Halodule wrightii Aschers.; Ruppia maritima; Osmotic adjustment 1. Introduction Seagrasses are keystone species in many shallow lagoons

  11. New highly polymorphic microsatellite markers for the aquatic angiosperm Ruppia cirrhosa reveal population diversity

    E-print Network

    Teixeira, Sara

    described for Ruppia maritima. These 12 markers were tested in four R. cirrhosa populations from Ruppia maritima. Ces 12 marqueurs ont été testés dans quatre populations de R. cirrhosa provenant du sudNOTE New highly polymorphic microsatellite markers for the aquatic angiosperm Ruppia cirrhosa

  12. ecological modelling 1 9 6 ( 2 0 0 6 ) 379394 available at www.sciencedirect.com

    E-print Network

    of the observed behaviours, a cellular automaton to describe the dynamics of wigeongrass (Ruppia maritima@dsi.unifi.it (S. Marsili-Libelli). between macroalgae and rooted macrophytes (wigeongrass, Ruppia maritima-year simulations show the expansion of the existing Ruppia prairies in accordance with the observations. © 2006

  13. An Insight into the Interaction Mode Between CheB and Chemoreceptor from Two Crystal Structures of CheB Methylesterase Catalytic Domain

    SciTech Connect

    K Cho; B Crane; S Park

    2011-12-31

    We have determined 2.2 {angstrom} resolution crystal structure of Thermotoga maritima CheB methylesterase domain to provide insight into the interaction mode between CheB and chemoreceptors. T. maritima CheB methylesterase domain has identical topology of a modified doubly-wound {alpha}/{beta} fold that was observed from the previously reported Salmonella typhimurium counterpart, but the analysis of the electrostatic potential surface near the catalytic triad indicated considerable charge distribution difference. As the CheB demethylation consensus sites of the chemoreceptors, the CheB substrate, are not uniquely conserved between T. maritima and S. typhimurium, such surfaces with differing electrostatic properties may reflect CheB regions that mediate protein-protein interaction. Via the computational docking of the two T. maritima and S. typhimurium CheB structures to the respective T. maritima and Escherichia coli chemoreceptors, we propose a CheB:chemoreceptor interaction mode.

  14. US Forest Service Species Assessments in Region 2 Complied 1/05/2007 by Steve J. Popovich, USFS, ARP SO, Fort Collins, Colorado

    E-print Network

    /scp/evalrationale/index.shtmlUTH To date, all completed plant assessments include those below. Coming soon: Triteleia grandiflora, Liparis loeselii, Penstemon laricifolius ssp. exilifolius, and Armeria maritima ssp. siberica. Dicots: · HTUAletes

  15. Supporting Online Material Single Molecule Measurement

    E-print Network

    Schuler, Ben

    maritima. Microfluidic Mixer A pattern of channels (Fig. 1) was cut into the surface of a silicon wafer. Computations were done using CFD-ACE+ software (CFDRC, Huntsville, AL). Fluid entry to and exit from the mixer

  16. ARTICLE IN PRESS Maltodextrin-binding proteins from diverse bacteria and archaea are

    E-print Network

    , Thermococcus litoralis, Vibrio cholerae, Thermotoga 18 maritima, and Yersinia pestis) to promote the solubility varying degrees of amino 59acid sequence identity with Eco MBP (Yersinia pestis (Ype), 6085%; Vibrio

  17. Population Status and Evaluation of Landscape Change for the Lower Keys Marsh Rabbit 

    E-print Network

    Schmidt, Jason Alan

    2011-02-22

    halophytic vegetation that are inundated daily with saltwater. Dominant plant species found in this zone included glasswort (Salicornia spp.), key grass (Monanthochloe littoralis), and saltwort (Batis maritima). At slightly higher elevations, salt...

  18. Aquatic macrophyte and animal communities in a recently restored brackish marsh: possible influences of restoration design and the invasive plant species Myriophyllum spicatum 

    E-print Network

    Bell, Michael Thomas

    2012-07-16

    (Eurasian watermilfoil) which may be competing with the native aquatic grass, Ruppia maritima (widgeongrass) for essential nutrients. In this study, an attempt was made to link restoration design with both SAV and aquatic fauna community structures by using...

  19. Evaluating dredged material placement alternatives 

    E-print Network

    Wooters, Kelly Lynne

    1989-01-01

    . Some of the characteristic species of the area are listed in Table 4. 3. Grasses located in the bay include Halodule beaudettei, Ruppia maritima, Thalassia testudinum, Halophila engelmanni, and Cymodocea filiformis (White et al. 1983). Some mangrove...

  20. Elucidating the chemical and thermal unfolding profiles of organophosphorus hydrolase and increasing its operational stability 

    E-print Network

    Armstrong, Charles David

    2009-05-15

    triosephosphate isomerase from Thermotoga maritima forms a covalently linked tetrameric complex with phosphoglycerate kinase (PGK) to form a bifunctional enzyme. Stability and catalytic studies of the isolated TIM enzyme and the PGK-TIM hybrid showed...

  1. Evaluation of selected provenances of taxodium distichum for drought, alkalinity and salinity tolerance. 

    E-print Network

    Denny, Geoffrey Carlile

    2009-05-15

    L.) spp. (Zwack et al., 1998; St. Hilaire and Graves, 2001), seaside alder (Alnus maritima (Marsh.) Muhl. ex Nutt.) (Schrader and Graves, 2000), pecan (Carya illinoinensis (Wangenh.) K. Koch) (Wood et al., 1998), Atlantic whitecedar (Chamaecyparis...

  2. Application of conditional sampling for measuring ecosystem-scale carbon dioxide exchange in coastal wetlands 

    E-print Network

    Cobos, Douglas Russell

    1999-01-01

    and Salt cornia virgi ni ca, with distinct patches of Batis mari ti ma, Lyci um carolinianum, Suadea linearis, Monathocloe littoralis, Distichlis spicata, and Limonium nashii spread throughout the delta region. Ruppia maritima is the dominant submergent...

  3. Effects of Vegetation Structure and Elevation on Lower Keys Marsh Rabbit Density 

    E-print Network

    Dedrickson, Angela

    2012-02-14

    .) and buttonwood. Herbaceous halophytic plant species within the transition zone also change as elevation increases and transition from glasswort (Salicornia spp.), key grass (Monanthochloe littoralis), and saltwort (Batis maritima) to sea daisy (Borrichia...

  4. A Comparison of Vegetation in Artificially Isolated Wetlands on West Galveston Island 

    E-print Network

    Wilson, Ashley

    2012-07-16

    and Batis maritima are also indicators of salt marsh systems (Fisher 1973). Tidal freshwater marshes are usually dominated by a variety of grasses and by annual and perennial broadleaved aquatic plants (Mitsch and Gosselink 2007). Nontidal freshwater...

  5. The effect of NaCl salinity on bell pepper photosynthesis 

    E-print Network

    Bethke, Paul Carl

    1989-01-01

    . Then, in order to maintain osmotic balance between the vacuole and the cytoplasm, osmolytes are synthesized in the protoplasm. Yeo (77) found that while Na+ and K+ were not accumulated in the cytoplasm of Suaeda maritima, a halophyte...

  6. Observer Name(s) & contact info Circle the zone you are in

    E-print Network

    Columbia University

    Peltandra viginica 75 Common Reed Phragmites australis 76 Pokeweed Phytolacca americana 77 Eastern White hydropiperoides 86 Beach Plum Prunus maritima 87 Black Cherry Prunus serotina 88 Northern Red Oa

  7. A floral-derived compound attractive to the tephritid fruit fly parasitoid Diachasmimorpha longicaudata (Hymenoptera: Braconidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many adult hymenopteran parasitoids, even host-feeding species, consume the nectar of flowering plants. Previous field studies had identified plants attractive (Lobularia maritima L.) and unattractive (Spermacoce verticillata L) to certain opiine braconids (Hymenoptera). Under laboratory conditions,...

  8. Kulturverfahren zur Bestimmung der Salz- und Über-flutungsverträglichkeit von Puccinellia spp. (Gramineae)

    Microsoft Academic Search

    K. von Weihe; G. Dreyling

    1970-01-01

    In the ecology ofPuccinellia species (P. maritima, P. distans, P. retroflexa andP. limosa of the German flora described to date) two environmental factors seem to be very important: the salinity of the soil or of the tidal sea water and, especially in regard toP. maritima, the periodical inundation during the tidal cycle. The latter species forms an important community (Puccinellietum

  9. Pesticide and heavy metal residues in Louisiana river otter 

    E-print Network

    Beck, Debra Lynn

    1977-01-01

    ), three-cornered grass (ScirCus olnevi), leafy three-square (~Scir us ro- bustus), and widgeongrass (~Ru ia maritima) . An intermediate vegeta- tion type oredominates farther inland, and consists primarily of wire- g, b llb g (~gdf 1 1 1 ), 6 9 (~9( ), 6.... ). The saline marsh type is characterized by oystergrass (~S ar- tins alterniflora), wiregrass, black rush (. Tuncus roemarianus), salt- wort (Batis maritima), black mangrove (Avicennia nitida), and saltgrass. Dominant species in the fresh marsh...

  10. Habitat classification and wintering duck use of Mission Bay, Texas 

    E-print Network

    Alldredge, Judy Meuth

    1984-01-01

    . Both types supported standing crops of mollusks, polychaetes, insect larvae, and plant seeds, but the Unconsolidated Bottom crops were small. The shallow Aquatic Bed habitats also had substantial stands of widgeongrass (~Ru ia maritima) in the fall... and Atmospheric Adm. 1981). A saltgrass (Distichlis ~s icata) community is the major vege- tation of the wetlands. Widgeongrass (~Ru ia maritima) is the most common submerged vascular vegetation. Sorghum (~Sor hum ~vul are) is the primary crop of cultivated...

  11. A Floral-Derived Compound Attractive to the Tephritid Fruit Fly Parasitoid Diachasmimorpha longicaudata (Hymenoptera: Braconidae)

    Microsoft Academic Search

    Eric Rohrig; John Sivinski; Peter Teal; Charles Stuhl; Martin Aluja

    2008-01-01

    Many adult hymenopteran parasitoids, even host-feeding species, consume the nectar of flowering plants. Previous field studies\\u000a had identified plants attractive (Lobularia maritima L.) and unattractive (Spermacoce verticillata L) to certain opiine braconids (Hymenoptera). Under laboratory conditions, Diachasmimorpha longicaudata (Ashmead), a parasitoid of tephritid fruit fly larvae and representative opiine, responded in flight tunnels to L. maritima but not to S.

  12. Native plant restoration combats environmental change: development of carbon and nitrogen sequestration capacity using small cordgrass in European salt marshes.

    PubMed

    Curado, Guillermo; Rubio-Casal, Alfredo E; Figueroa, Enrique; Grewell, Brenda J; Castillo, Jesús M

    2013-10-01

    Restoration of salt marshes is critical in the context of climate change and eutrophication of coastal waters because their vegetation and sediments may act as carbon and nitrogen sinks. Our primary objectives were to quantify carbon (C) and nitrogen (N) stocks and sequestration rates in restored marshes dominated by Spartina maritima to provide support for restoration and management strategies that may offset negative aspects of eutrophication and climate change in estuarine ecosystems. Sediment C content was between ca. 13 mg C g(-1)and sediment N content was ca. 1.8 mg N g(-1). The highest C content for S. maritima was recorded in leaves and stems (ca. 420 mg C g(-1)) and the lowest in roots (361?±?4 mg C g(-1)). S. maritima also concentrated more N in its leaves (31?±?1 mg N g(-1)) than in other organs. C stock in the restored marshes was 29.6 t C ha(-1); ca. 16 % was stored in S. maritima tissues. N stock was 3.6 t N ha(-1), with 8.3 % stored in S. maritima. Our results showed that the S. maritima restored marshes, 2.5 years after planting, were sequestering atmospheric C and, therefore, provide some mitigation for global warming. Stands are also capturing nitrogen and reducing eutrophication. The concentrations of C and N contents in sediments, and cordgrass relative cover of 62 %, and low below-ground biomass (BGB) suggest restored marshes can sequester more C and N. S. maritima plantations in low marshes replace bare sediments and invasive populations of exotic Spartina densiflora and increase the C and N sequestration capacity of the marsh by increasing biomass production and accumulation. PMID:23591677

  13. Cues of Maternal Condition Influence Offspring Selfishness

    PubMed Central

    Wong, Janine W. Y.; Lucas, Christophe; Kölliker, Mathias

    2014-01-01

    The evolution of parent-offspring communication was mostly studied from the perspective of parents responding to begging signals conveying information about offspring condition. Parents should respond to begging because of the differential fitness returns obtained from their investment in offspring that differ in condition. For analogous reasons, offspring should adjust their behavior to cues/signals of parental condition: parents that differ in condition pay differential costs of care and, hence, should provide different amounts of food. In this study, we experimentally tested in the European earwig (Forficula auricularia) if cues of maternal condition affect offspring behavior in terms of sibling cannibalism. We experimentally manipulated female condition by providing them with different amounts of food, kept nymph condition constant, allowed for nymph exposure to chemical maternal cues over extended time, quantified nymph survival (deaths being due to cannibalism) and extracted and analyzed the females’ cuticular hydrocarbons (CHC). Nymph survival was significantly affected by chemical cues of maternal condition, and this effect depended on the timing of breeding. Cues of poor maternal condition enhanced nymph survival in early broods, but reduced nymph survival in late broods, and vice versa for cues of good condition. Furthermore, female condition affected the quantitative composition of their CHC profile which in turn predicted nymph survival patterns. Thus, earwig offspring are sensitive to chemical cues of maternal condition and nymphs from early and late broods show opposite reactions to the same chemical cues. Together with former evidence on maternal sensitivities to condition-dependent nymph chemical cues, our study shows context-dependent reciprocal information exchange about condition between earwig mothers and their offspring, potentially mediated by cuticular hydrocarbons. PMID:24498046

  14. Piper kelleyi, a hotspot of ecological interactions and a new species from Ecuador and Peru.

    PubMed

    Tepe, Eric J; Rodríguez-Castañeda, Genoveva; Glassmire, Andrea E; Dyer, Lee A

    2014-01-01

    We describe Piper kelleyi sp. nov., a new species from the eastern Andes of Ecuador and Peru, named in honor of Dr. Walter Almond Kelley. Piper kelleyi is a member of the Macrostachys clade of the genus Piper and supports a rich community of generalist and specialist herbivores, their predators and parasitoids, as well as commensalistic earwigs, and mutualistic ants. This new species was recognized as part of an ecological study of phytochemically mediated relationships between plants, herbivores, predators, and parasitoids. Compared to over 100 other Piper species surveyed, Piper kelleyi supports the largest community of specialist herbivores and parasitoids observed to date. PMID:24596490

  15. Enzymatic synthesis of 2'-ara and 2'-deoxy analogues of c-di-GMP.

    PubMed

    Shchokolova, Anastasia S; Rymko, Alexander N; Kvach, Sergey V; Shabunya, Polina S; Fatykhava, Svetlana A; Zinchenko, Anatoly I

    2015-06-01

    The substrate specificity of recombinant full-length diguanylate cyclase (DGC) of Thermotoga maritima with mutant allosteric site was investigated. It has been originally shown that the enzyme could use GTP closest analogues - 2'-deoxyguanosine-5'-triphosphate (dGTP) and 9-?-D-arabinofuranosyl-guanine-5'-triphosphate (araGTP) as the substrates. The first demonstrations of an enzymatic synthesis of bis-(3'-5')-cyclic dimeric deoxyguanosine monophosphate (c-di-dGMP) and the previously unknown bis-(3'-5')-cyclic dimeric araguanosine monophosphate (c-di-araGMP) using DGC of T. maritima in the form of inclusion bodies have been provided. PMID:25965330

  16. Classification and waterfowl use of ponds in south Texas 

    E-print Network

    McAdams, Matthew Stephen

    1987-01-01

    . Scientific name Common name N Submergents Unknown Chara spp. N~a'as uadalu ensis Peto d ~pot o to E t' t ~Pp *'t t t Alt ho o t Co PP . R~uia maritima Algae Muskgrass Southern naiad Longleaf pondweed Fennelleaf pondweed Fondweed Widgeongrass 82... 72 70 6 6 18 5 Emergents I! ' o 1 A 011 1' B~aco a monnieri Batis maritima C~ tl lt* C~ ~dt t C~ 1 C~ do t C~o 1 ox~le ~is surinamensis C~t C~ ' f1* Dichromena colorata ~ h' o hlo ~11' Echinodorus cordifolius ~ h' od E 1 Echinodorus...

  17. Food choice of wintering redhead ducks Aythya americana and utilization of available resources in Lower Laguna Madre, Texas 

    E-print Network

    Cornelius, Stephen Eugene

    1975-01-01

    of the Gulf of Mexico is related to the abundance of various marine and brackish water submergent spermatophytes grow- ing in the . , hallow, protected bays. Widgeongrass (~Ru ia maritima) was considered by NcAtee (1915) as the most im- portant waterfowl...). The vege- tation assumes a more heterogeneous character in Port 2 0 1 8 y h t 9 (~Sd' f'1 f turtlegrass (Thalassia testudinum) and gulf Halophila (~H1 h 1~'1') ' y' g d* t' (8 8 h 1966) . Widgeongrass (~Ru ia maritima) is infrequently found near...

  18. Inbreeding depression in an insect with maternal care: influences of family interactions, life stage and offspring sex.

    PubMed

    Meunier, J; Kölliker, M

    2013-10-01

    Although inbreeding is commonly known to depress individual fitness, the severity of inbreeding depression varies considerably across species. Among the factors contributing to this variation, family interactions, life stage and sex of offspring have been proposed, but their joint influence on inbreeding depression remains poorly understood. Here, we demonstrate that these three factors jointly shape inbreeding depression in the European earwig, Forficula auricularia. Using a series of cross-breeding, split-clutch and brood size manipulation experiments conducted over two generations, we first showed that sib mating (leading to inbred offspring) did not influence the reproductive success of earwig parents. Second, the presence of tending mothers and the strength of sibling competition (i.e. brood size) did not influence the expression of inbreeding depression in the inbred offspring. By contrast, our results revealed that inbreeding dramatically depressed the reproductive success of inbred adult male offspring, but only had little effect on the reproductive success of inbred adult female offspring. Overall, this study demonstrates limited effects of family interactions on inbreeding depression in this species and emphasizes the importance of disentangling effects of sib mating early and late during development to better understand the evolution of mating systems and population dynamics. PMID:23981229

  19. Light absorption and scattering by cell suspensions of some cyanobacteria and microalgae

    Microsoft Academic Search

    M. N. Merzlyak; O. B. Chivkunova; I. P. Maslova; K. R. Naqvi; A. E. Solovchenko; G. L. Klyachko-Gurvich

    2008-01-01

    Absorption spectra of cyanobacteria (Anacystis nidulans, Anabaena variabilis, and Chlorogloeopsis fritschii), red (Cyanidium caldarum and Porphyridium cruentum), green (Dunaliella maritima and Dunaliella salina) and diatom (Thalassiosira weisflogii) alga cell suspensions are presented; the spectra were obtained by using an approach developed earlier to compensate for\\u000a scattering [1, 2]. In all species, the shapes of the absorption spectra were independent of

  20. Ingestion, enzymatic digestion and absorption of particles derived from different vegetal sources by the cockle Cerastoderma edule

    Microsoft Academic Search

    U. Arambalza; M. B. Urrutia; E. Navarro; I. Ibarrola

    2010-01-01

    Ingestion, enzymatic digestion and absorption of particulate detrital matter derived from six different vegetal sources by the common cockle Cerastoderma edule was analyzed in a series of seasonal experiments performed in March, May and October 2005. Two green macroalgae: Ulva lactuca and Enteromorpha sp; two vascular plants: Spartina maritima and Juncus maritimus, the red macroalgae Gracilaria gracilis; and the microalgae

  1. Photoprotective role of inflorescence and UV-radiation effects on pollen viability of different freshwater plants

    Microsoft Academic Search

    Rafael M. Conde-Álvarez; Félix L. Figueroa; Elena Bañares-España; José M. Nieto-Caldera

    2008-01-01

    .  The possible protective role against ultraviolet (UV) radiation of the sheathing leaves that wrap the young flowers of Ruppia drepanensis and Althenia orientalis was assessed. The effects of UV radiation on the viability of their pollen grains and those of R. maritima were also analysed. The absorption of the sheathing leaves of R. depranensis for visible and UV wavelengths was

  2. Molecular and Morpho-Physiological Characterization of Sea, Ruderal and Cultivated Beets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beta vulgaris genetic resources are essential for broadening genetic base of sugar beet and developing cultivars adapted to adverse environmental conditions. Wild beets (sea beets, B. vulgaris spp. maritima and their naturalized introgressions with cultivated beets known as ruderal beets) harbor su...

  3. The seed oils of some species of the family Cruciferae

    Microsoft Academic Search

    V. S. Dolya; E. N. Shkurupii; T. V. Podzolkova; N. A. Kaminskii

    1973-01-01

    Summary  The physicochemical properties of the oils of the seeds of seven plants of the family Cruciferae —Cakile maritima, Sisymbrium altissimum, Sisymbrium Loeselii, Descurainia Sophia, Erysimum cheiranthoides, Brassica amoracioides andCrambe pontica — have been studied and their fatty acid compositions have been determined. The results obtained showed no marked differences\\u000a from those given in the literature.

  4. Heavy metal uptake by marsh plants in hydroponic solution cultures

    Microsoft Academic Search

    C. R. Lee; T. C. Sturgis; M. C. Landin

    1981-01-01

    Eight marsh plants were grown in chemically controlled hydroponic solutions containing three concentrations of heavy metals to evaluate the ability of each plant species to take up and accumulate heavy metals. The marsh plants studited were Cyperus esculentus, Scirpus validus, Spartina patens, Scirpus robustus, Distichiis spicata, Triglochin maritima, Spartina alterniflora, and Spartina foliosa. These species represented freshwater, brackish water, and

  5. Phytosociological survey of Northern California dunes

    Microsoft Academic Search

    Simona Casavecchia; Edoardo Biondi

    2001-01-01

    The vegetation of sandy coasts of California between Point Arena and Morro Bay, was investigated. Near the tide line, was annual vegetation of the Cakile maritima community. Dunal vegetation included the new Abronio latifoliae-Ambrosietea chamissonis class with the new Ambrosietalia chamissonis order and the new Ambrosion chamissonis alliance (proposed). Foredune vegetation included the two new Abronio latifoliae-Elymetum mollis and Atriplici

  6. Evidence for preferential depths of metal retention in roots of salt marsh plants

    Microsoft Academic Search

    Miguel Caetano; Carlos Vale; Rute Cesário; Nuno Fonseca

    2008-01-01

    Depth variation (2-cm resolution) of Fe, Mn, Zn, Cr, Ni, Cu, As and Cd concentrations were determined in belowground biomass of Spartina maritima and Sarcocornia fruticosa and in sediments between roots from two marshes in Tagus (Rosário) and Guadiana (Castro Marim) estuaries in Portugal with different anthropogenic pressures. Levels of metals were also determined in aboveground plant parts. Metal concentrations

  7. [Nutritional prophylaxis of hypovitaminosis in Mauritania. Cattle rearing and beta-carotene].

    PubMed

    Chamoiseau, G; Chassot, P; Leclercq, M

    1992-01-01

    Some traditional plants known for their resistance to the desert weather, has been studied for their level in beta-carotene. They are called Spartima maritima and Panicum turgidum. We hope with these plants and others, elaborate some zootechnic project. It will be very useful for all the sahel zone from Atlantic to Pakistan. PMID:1344969

  8. Changes in Microbial Biomass Parameters of a Heavy Metal-Contaminated Calcareous Soil during a Field Remediation Experiment

    Microsoft Academic Search

    R. Clemente; C. de la Fuente; R. Moral; M. P. Bernal

    2007-01-01

    Soil microbial biomass parameters give useful information about the restoration degree and quality of contaminated soils. These pa- rameters were studied in a field experiment where the effect of two organic amendments on the bioavailability of heavy metals in an agri- cultural soil and on their accumulation in Beta vulgaris and Beta maritima was assessed. The soil was a calcareous

  9. The importance of salt-marsh wetness for seed exploitation by dabbling ducks Anas sp

    Microsoft Academic Search

    Ole R. Therkildsen; Thomas Bregnballe

    2006-01-01

    The relationship between the inundation of a salt marsh in southeast Denmark not subject to lunar tides and the availability and predation of seeds of the annuals Salicornia spp. and Suada maritima by autumn staging dabbling ducks was studied by carrying out exclosure experiments over the course of 2 years. There was a marked difference in the wetness of the salt

  10. A DNA repair system specific for thermophilic Archaea and bacteria predicted by genomic context analysis

    Microsoft Academic Search

    Kira S. Makarova; L. Aravind; Nick V. Grishin; Igor B. Rogozin; Eugene V. Koonin

    2002-01-01

    During a systematic analysis of conserved gene context in prokaryotic genomes, a previously unde- tected, complex, partially conserved neighborhood consisting of more than 20 genes was discovered in most Archaea (with the exception of Thermoplasma acidophilum and Halobacterium NRC-1) and some bacteria, including the hyperthermophiles Thermotoga maritima and Aquifex aeolicus. The gene composi- tion and gene order in this neighborhood

  11. Evaluation of genetic diversity and root traits of sea beet accessions of the Adriatic Sea coast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty nine sea beet [Beta vulgaris L. subsp. maritima (L.) Arcang.] accessions of the Adriatic coast were screened genetically and for their adaptive morpho-functional root traits in order to identify new sources of abiotic resistances for sugar beet breeding programs. Genetic diversity was evaluat...

  12. Beet curly top resistance in USDA-ARS Plant Introductions, 2012

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty sea beet (Beta vulgaris subsp. maritima (L.) Arcang) and beet (Beta vulgaris subsp. vulgaris L.) plant introduction (PI) accessions from the Beta collection of the USDA-ARS National Plant Germplasm System were screened for resistance to Beet severe curly top virus (BSCTV) and other closely re...

  13. Beet curly top resistance of USDA-ARS National Plant Germplasm System plant introductions, 2010

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twenty-six wild beet (Beta vulgaris subsp. maritima (L.) Arcang) accessions from the Beta collection of the USDA-ARS National Plant Germplasm System were screened for resistance to Beet severe curly top virus (BSCTV) and other closely related Curtovirus species in 2010. The curly top evaluation was...

  14. The halophilous vegetation of the Po Delta (northern Italy)

    Microsoft Academic Search

    C. Ferrari; R. Gerdol; F. Piccoli

    1985-01-01

    The halophilous vegetation in the Po Delta region (north Adriatic) has been studied with the Braun-Blanquet method. Vegetation types have been defined by numerical classification of vegetation data. Their ecology has been studied by indirect gradient analysis. The following three main groups of phytocoena have been recognized. (1) Perennial halophytic vegetation (class Puccinellio-Salicornietea) including 7 associations: Spartinetum maritimae, Puccinellietum palustris,

  15. Evaluation of antioxidant activities of the edible and medicinal Suaeda species and related phenolic compounds

    Microsoft Academic Search

    Samia Oueslati; Trabelsi Najla; Boulaaba Mondher; Legault Jean; Abdelly Chedly; Ksouri Riadh

    Antioxidants are the chemical substances that reduce or prevent oxidation. The present study aimed to assess in vitro and ex vivo antioxidant activities of four acetonic extracts Tunisian halophytes (Suaeda fruticosa, Suaeda pruinosa, Suaeda mollis and Suaeda maritima). Various experimental models were used for characterization of antioxidant activities of shoot extracts. Eventually, the promising specie was subjected to phenolic identification

  16. Mating Behaviors604 littorea (Dermaptera) in New Zealand and the larvae of two sisyrids

    E-print Network

    Gwynne, Darryl T.

    ­506. Christiansen, K., and Bellinger, P. (1988). Marine littoral Collembola of North and Central America. Bull. Mar., Rüssbeck, R., Biefang, M., and Baumgärtl, H. (1999). Intertidal respiration of Anurida maritima (Collembola (Archaeognatha and Thysanura) and Ellipura (Collembola, Protura, and Diplura), sperm transfer is indirect

  17. Losses and gains to the Scottish Flora

    Microsoft Academic Search

    Michael M. Scott

    1990-01-01

    Several examples are discussed of plants which have been exterminated from or introduced to Scotland as a result of human activities, and an attempt is made to draw lessons from these case histories. Four rare or threatened Scottish plants, Homogyne alpina, Mertensia maritima, Primula scotica, and Pteridium aquilinum ssy. latiusculum are considered to illustrate future plant conservation imperatives. Threats to

  18. B. subtilis ykuD Protein at 2.0 Resolution: Insights into the Structure and Function of a Novel, Ubiquitous Family of

    E-print Network

    Bacillus anthracis, Vibrio chol- era, Clostridium tetani, and others, to nonpathogenic Escherichia coli of the prod- uct of the Bacillus subtilis ykuD gene was solved by the multiwavelength anomalous dispersion, Thermotoga maritima, Bacillus subtilis, and so forth. All ErfK/YbiS/YhnG domains contain a highly conserved

  19. Palaeoecology of Lake Zeribar, Iran, in the Pleniglacial, Lateglacial and Holocene, reconstructed from plant macrofossils

    Microsoft Academic Search

    Krystyna Wasylikowa

    2005-01-01

    Changes in aquatic and marsh vegetation at Lake Zeribar in the Zagros Mountains, Iran, during the last 40 000 years were reconstructed on the basis of plant macrofossils. Several episodes of low water level and increased salinity were evidenced by peaks of Chenopodium rubrum seeds and the occurrence of obligate (Salicornia sp., Ruppia maritima and Suaeda sp.) and facultative (Zannichellia

  20. Distribution of aquatic plants and absorption of radionuclides by plants through the leaf surface in brackish Lake Obuchi, Japan, bordered by nuclear fuel cycle facilities

    Microsoft Academic Search

    K. Kondo; H. Kawabata; S. Ueda; H. Hasegawa; J. Inaba; O. Mitamura; Y. Seike; Y. Ohmomo

    2003-01-01

    We investigated the distribution of aquatic plants and the absorption of radionuclides by them in the brackish Lake Obuchi, Japan, which is bordered by nuclear fuel cycle facilities. We studied 5 species of submerged plants: Zannichellia palustris, Ruppia maritima, Potamogeton pectinatus, Zostera japonica, and Z. marina. The plants contained many elements, including radionuclides. The concentrations of 238U, 137Cs, and 90Sr

  1. Nutritional and antinutritional significance of four unconventional legumes of the genus Canavalia – A comparative study

    Microsoft Academic Search

    K. R. Sridhar; S. Seena

    2006-01-01

    Developing countries are under the clutch of malnutrition due to a lack of protein rich food. Protein supply can be broadened by exploration and exploitation of alternative legume sources. Even though many wild legume landraces have been identified, their utilization is limited due to insufficient attention. Canavalia gladiata, Canavalia ensiformis, Canavalia maritima and Canavalia cathartica are the common under-exploited legume

  2. Further contribution to anatomy of maritime strand plants of India

    Microsoft Academic Search

    T Ananda Rao; T R B Naidu; G C Das

    1983-01-01

    Anatomy of vegetative parts and its ecological significance in 10 taxa of Indian maritime strand flora, namelyAllmania nodiflora, Canavalia maritima, Euphorbia atoto, Halopyrum mucronatum, Indigofera uniflora, Messerchimidia argentea,\\u000a Scaevola plumierii, Scaevola taccada, Sesamum prostratum andThespesia populnea are described.

  3. Endophytic fungal diversity of 2 sand dune wild legumes from the southwest coast of India.

    PubMed

    Seena, S; Sridhar, K R

    2004-12-01

    Endophytic fungi of 3 age classes (seeds, seedlings, and mature plants) and 5 tissue classes (cotyledons, seed coats, roots, stems, and leaves) of coastal sand dune legumes Canavalia cathartica and Canavalia maritima were assessed by plating surface-sterilized segments on malt extract agar. Forty-six fungal taxa comprising 6 ascomycetes, 33 mitosporic fungi, 2 zygomycetes, and 5 sterile morphospecies were recovered. There was no significant difference in the colonization frequency of endophytes between plant species (p = 0.4098, Student's t test). Among the age classes, endophytic fungi colonized over 90% of seedlings and mature plants. Similarly, among tissue classes, endophytic fungi colonized over 90% of root, stem, and leaf segments. Diversity and richness of endophytic fungi were higher in C. cathartica than in C. maritima. Rarefaction curves revealed a "higher expected number of species" in mature plants of C. cathartica and seedlings of C. maritima, whereas it was highest in leaves of both plant species. The most dominant endophyte, Chaetomium globosum, colonized over 50% of the root, stem, and leaf segments of C. maritima and over 50% of the root segments of C. cathartica. The colonization frequency of C. globosum was found to be 5%-12.5% in seeds and increased up to 40%-64.4% in seedlings or mature plants. Halosarpheia sp. was the only marine fungus recovered among the endophytes. PMID:15714232

  4. PLANT SEED LECTINS. A POSSIBLE MARKER FOR CHEMOTAXONOMY OF THE GENUS Canavalia

    Microsoft Academic Search

    BENILDO SOUSA CAVADA; EDSON PAULA NUNES; AFRÂNIO GOMES FERNANDES; TADEU ABREU

    Canavalia bicarinata, Canavalia bonariensis, Canavalia brasiliensis, Canavalia dictyota, Canavalia ensiformis, Canavalia gladiata, Canavalia maritima and Canavalia plagyosperma seeds were investigated with respect to phenologic aspects (size, mass, hilum length) and with respect to their chemical composition. Thus, the total nitrogen content of the seed flours were determined, and the flours were submitted to extraction at different pH values. The seed

  5. Genetic analysis of male fertility restoration in wild cytoplasmic male sterility G of beet

    Microsoft Academic Search

    Pascal Touzet; Nathalie Hueber; Alexandra Bürkholz; Stephen Barnes; Joël Cuguen

    2004-01-01

    Cytoplasmic male sterility (CMS) has been used in the breeding of sugar beet for decades but is also more generally an important feature of the reproductive system in its wild relative, Beta vulgaris ssp. maritima. Among the several CMSs found in wild populations, the G CMS is a mitochondrial variant of the respiratory chain. The segregants derived from a cross

  6. The vegetation of ultrabasic soils on the Isle of Rhum II. The causes of the debris

    Microsoft Academic Search

    John Henry H. Looney; John Proctor

    1989-01-01

    The relationship between the Rhum ultrabasic skeletal soils and their debris vegetation was investigated by plant analyses and field and laboratory experiments. Samples of Agrostis vinealis, Arenaria norvegica ssp norvegica, Calluna vulgaris, Festuca vivipara, Plantago maritima and Racomitrium lanuginosum from these soils usually had low concentrations of potassium and calcium, and high concentrations of sodium, magnesium (and high Mg\\/Ca quotients),

  7. Rhizoctonia Crown and Root Rot Resistance of Beta Plant Introductions from the USDA, Agricultural Research Service's National Plant Germplasm System, 2010

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty wild beet (Beta vulgaris subsp. maritima (L.) Arcang) plant introduction (PI) accessions from the Beta collection of the USDA-ARS National Plant Germplasm System were screened for resistance to Rhizoctonia root and crown rot, at the USDA-ARS Fort Collins, CO Research Farm. The Rhizoctonia sc...

  8. NOTICE OF RELEASE OF SUGARBEET GERMPLASM LINES CN12 AND CN72

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarbeet germplasm lines CN12 and CN72 were officially released on 02/28/05. These releases are multigerm, random-mated populations that segregate for resistance to sugarbeet cyst nematode from the wild species Beta vulgaris subsp. maritima. Cyst nematode is one of the most damaging pests of suga...

  9. Comparative dispersal effectiveness of wigeongrass seeds by waterfowl wintewring in south-west Spain: quantitative and qualitative aspects

    Microsoft Academic Search

    Jordi Figuerola; Andy J. Green; L. Santamaría

    2002-01-01

    The effectiveness of a seed disperser depends on the quantity of seed dispersed and the quality of dispersal provided to each seed. Relationships between the quantity and quality components and their dependence on characteristics of the dispersers remain largely uninvestigated. 2 The effectiveness of different waterfowl species at dispersing seeds of Ruppia maritima was evaluated in a wetland in south-west

  10. Diet composition and feeding strategy of the southern pipefish Syngnathus folletti in a Widgeon grass bed of the Patos Lagoon Estuary, RS, Brazil

    Microsoft Academic Search

    Alexandre M. Garcia; Ricardo M. Geraldi; João P. Vieira

    2005-01-01

    Pipefish species are poorly known representatives of the family Syngnathidae, which have been increasingly threatened by anthropogenic activities. We describe the diet composition and feeding strategy of southern pipefish Syngnathus folletti inhabiting a Widgeon grass (Ruppia maritima L.) bed in the estuarine zone of Patos Lagoon, southern Brazil. We also investigated whether mouth gape affected the size of prey items

  11. Cellular Automata Modelling of Seagrass in the Orbetello Lagoon

    Microsoft Academic Search

    Stefano Marsili-Libelli; Elisabetta Giusti

    2004-01-01

    This paper describes the evolution in time and spa ce of wigeongrass (Ruppia maritima) meadows in the Orbetello lagoon, in central Italy, where the control of the submerged vegetation, with a critical coexistence between macroalgae and macrophytes, is the key management problem. While macroalgae are liable to cause dystrophic crises, m acrophytes oxygenate and stabilise the sediment and thus control

  12. On the status of seagrass communities in the Black Sea

    Microsoft Academic Search

    Nataliya A. Milchakova

    1999-01-01

    There are six species of seagrasses in the Black Sea: Zostera marina (eelgrass), Z. noltii, Potamogeton pectinatus, Ruppia maritima, R. spiralis and Zannichellia major. Eelgrass grows in shallow bays of the northwestern Black Sea in extensive underwater meadows. Following storm events, this species yields abundant litter on the beach. The biomass of eelgrass litter cast ashore is estimated to be

  13. Registration of EL54 and EL55 sugarbeet germplasms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    EL54 (PI 654357) is a sugarbeet germplasm derived from wild beet (Beta vulgaris ssp. maritima) accession WB879 (PI 540625), released in the interest of broadening the genetic base of sugar beet. The parent accession WB879, collected in 1989 from Port-de-Houet, France. EL54 has shown excellent Aphan...

  14. NUTRIENT SOLUTION CONCENTRATION AFFECTS GROWTH OF SUBIRRIGATED BEDDING PLANTS

    Microsoft Academic Search

    Jong-Goo Kang; Marc W. van Iersel

    2002-01-01

    To evaluate the effects of nutrient solution concentration on growth of alyssum [Lobularia maritima (L.) Desv. ‘New Carpet of Snow’], celosia (Celosia argentea L. ‘Gloria Scarlet’), dianthus (Dianthus chinensis L. ‘Telstar Crimson’), gomphrena (Gomphrena globosa L. ‘Gnome White’), stock [Matthiola incana (L.) R. Br ‘Special Mix’], and zinnia (Zinnia elegans Jacq. ‘Dreamland Mix’), we grew plants with five different concentrations

  15. Effects of alyssum flowers on the longevity, fecundity, and sex ratio of the leafroller parasitoid Dolichogenidea tasmanica

    Microsoft Academic Search

    Lisa A. Berndt; Steve D. Wratten

    2005-01-01

    A laboratory experiment assessed the effect of floral food resources on the longevity, fecundity, and sex ratio of Dolichogenidea tasmanica (Cameron) (Hymenoptera: Braconidae), a parasitoid of leafrollers (Lepidoptera: Tortricidae). Alyssum (Lobularia maritima (L.), Brassicaceae) plants with flowers were compared with plants without flowers, with water available in both treatments. Adult parasitoids were provided with an excess of second-instar larval hosts,

  16. Flower color affects tri-trophic-level biocontrol interactions

    Microsoft Academic Search

    Mahmuda Begum; Geoff M. Gurr; Steve D. Wratten; Helen I. Nicola

    2004-01-01

    The adults of many parasitoid species require nectar for optimal fitness, but very little is known of flower recognition. Flight cage experiments showed that the adults of an egg parasitoid (Trichogramma carverae Oatman and Pinto) benefited from alyssum (Lobularia maritima L.) bearing white flowers to a greater extent than was the case for light pink, dark pink or purple flowered

  17. The effects of floral understoreys on parasitism of leafrollers (Lepidoptera: Tortricidae) on apples in New Zealand

    Microsoft Academic Search

    N. A. Irvin; S. L. Scarratt; S. D. Wratten; C. M. Frampton; R. B. Chapman; J. M. Tylianakis

    2006-01-01

    Field and laboratory experiments on the conservation biocontrol of lepidop- teran leafroller pests were carried out in apples at Lincoln, New Zealand. 2 Apple understoreys were planted with replicated treatments of alyssum (Lobularia maritima), phacelia (Phacelia tanacetifolia) and buckwheat (Fagopyrum esculentum). 3 Rates of parasitism of experimentally released larvae of the light-brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), by

  18. Increasing vineyard floral resources may not enhance localised biological control of the leafroller Epiphyas postvittana (Lepidoptera: Tortricidae) by Dolichogenidea spp. (Hymenoptera: Braconidae) parasitoids

    Microsoft Academic Search

    V. A. Bell; R. J. Brightwell; P. J. Lester

    2006-01-01

    In agroecosystems, the efficacy of biological control exerted by many parasitoids is predicted to be enhanced where the availability of floral resources is increased. Such resources may attract parasitoids and enhance their longevity and fecundity. In Hawke's Bay, New Zealand, this prediction was tested by adding varying quantities of potted flowering alyssum (Lobularia maritima) (Brassicaceae) to plots containing apple plants

  19. AN EXTENDED FLOWERING AND FRUITING SEASON HAS FEW DEMOGRAPHIC EFFECTS IN A MEDITERRANEAN PERENNIAL HERB

    Microsoft Academic Search

    F. X AVIER PICO; HANS DE KROON; JAVIER RETANA

    2004-01-01

    The Mediterranean perennial herb Lobularia maritima shows an exception- ally extended flowering and fruiting that lasts for 10 months, from early September to late June. We hypothesized that such an extended phenology may be a flexible mechanism that enhances population persistence in variable Mediterranean environments, as fecundity in one part of the season could compensate for reproductive failure in another

  20. Nitrogen resorption from senescing leaves of three salt marsh plant species

    Microsoft Academic Search

    P. Cartaxana; F. Catarino

    2002-01-01

    Seasonalvariation in leaf nitrogen of mature green and senescent leaves and nitrogenresorption efficiency in three plants (Spartina maritima, Halimioneportulacoides and Arthrocnemum perenne) of aTagus estuary salt marsh are reported. Total nitrogen concentrations in greenand senescent leaves were higher during winter (December and March). Soilinorganic nitrogen availability showed an opposite pattern with higherconcentrations during summer (June and September) when total leaf

  1. Phytologia (April 2010) 92(1)68 DISCOVERY AND SNPS ANALYSES OF POPULATIONS OF

    E-print Network

    Adams, Robert P.

    98368 ABSTRACT Trees from two populations of Juniperus commonly identified as J. scopulorum growing that Juniperus trees identified as J. scopulorum Sarg. have been reported from the dry side (northeastPhytologia (April 2010) 92(1)68 DISCOVERY AND SNPS ANALYSES OF POPULATIONS OF JUNIPERUS MARITIMA

  2. Beneficial Insects

    NSDL National Science Digital Library

    0000-00-00

    Tutorials on insect predators that feed on insect and mite pests. Each tutorial has 50 questions; incorrect answers lead to additional information. Covers brown lacewings, ambush bugs, dragonflies, damselflies, paper wasps, earwigs, long-legged flies, predaceous mites, damsel bugs, minute pirate bug, tiger beetles, tachnid flies, parasitic nematodes, entomopathogenic fungi and viruses. Requires Windows. SOme illustrations may be most apporopriate for the southern U.S. A couple of the questions have rather arbitrary answers; in general, the tutorials are well constructed and the information is accurate. Requires Windows operating system; program must be downloaded to the comptuer's hard drive, but once loaded is easy to launch and use. $15. Part number SW 154.

  3. Embryos of the Viviparous Dermapteran, Arixenia esau Develop Sequentially in Two Compartments: Terminal Ovarian Follicles and the Uterus

    PubMed Central

    Tworzydlo, Waclaw; Kisiel, Elzbieta; Bilinski, Szczepan M.

    2013-01-01

    Three main reproductive strategies have been described among insects: most common oviparity, ovoviviparity and viviparity. In the latter strategy, the embryonic development takes place within the body of the mother which provides gas exchange and nutrients for embryos. Here we present the results of histological and EM analyses of the female reproductive system of the viviparous earwig, Arixenia esau, focusing on all the modifications related to the viviparity. We show that in the studied species the embryonic development consists of two “physiological phases” that take place in two clearly disparate compartments, i.e. the terminal ovarian follicle and the uterus. In both compartments the embryos are associated with synthetically active epithelial cells. We suggest that these cells are involved in the nourishment of the embryo. Our results indicate that viviparity in arixeniids is more complex than previously considered. We propose the new term “pseudoplacento-uterotrophic viviparity” for this unique two-phase reproductive strategy. PMID:23667700

  4. [The floristic diversity of the psammophyte vegetation in the region of Tlemcen (north-west Algeria)].

    PubMed

    Stambouli-Meziane, Hassiba; Bouazza, M; Thinon, Michel

    2009-08-01

    This study is devoted to the analysis of the psammophyte of the coastal and semi-continental dunes in Tlemcen. Interesting results have been obtained, in particular, on the biological and ecological aspects of the psammophyte. The interpretation from Factoriel analysis of correspondences enabled us to identify the different phytosociological classes (Cakiletea maritimae, Ammophiletea, Quercetea ilicis, Therobrachypodietea and Stellarietea mediae). Some of these classes (Cakiletea maritimae and Ammophiletea) inhabit, exceedingly well, the embryonic dunes. Some species (Therobrachypodietea) colonize the quickset dunes. Lastly, some others (Quercetea ilicis) settle in the more mature and stable dunes. By using the phytosociological and phytodynamical data, we have been able to understand the vegetation and its diversity. PMID:19632654

  5. The Late-Weichselian Flora of the Isle of Man.

    PubMed

    Dickson, C A; Dickson, J H; Mitchell, G F

    1970-03-26

    The last glacial deposits of the Ballaugh-Kirkmichael area in the north-east of the Isle of Man have been investigated by analysis of pollen and macroscopic fossils and by radiocarbon dating. Assemblages totalling over 160 taxa of vascular plants and mosses have been recorded from strata referred to Late-Weichselian zones I, II and III. Among the most noteworthy species are 46 not now living on the island; these include Dianthus deltoides, Juncus balticus, Lychnis viscaria, Ranunculus hyperboreus, Sibbaldia procumbens, Meesia tristicha, Helodium blandowii and Polytrichum norvegicum. The vegetation comprised a great diversity of communities of open, largely calcareous grassland, snow beds, mires both base-rich and base-poor, flushes, freshwater, inundated flats and calcareous dunes. Saline conditions are indicated by Glaux maritima and Triglochin maritima. Trees were represented only by Betula and the taller shrubs by Juniperus and Salix. PMID:22408824

  6. Polysaccharide degradation and synthesis by extremely thermophilic anaerobes.

    PubMed

    Vanfossen, Amy L; Lewis, Derrick L; Nichols, Jason D; Kelly, Robert M

    2008-03-01

    Extremely thermophilic fermentative anaerobes (growth T(opt) > or = 70 degrees C) have the capacity to use a variety of carbohydrates as carbon and energy sources. As such, a wide variety of glycoside hydrolases and transferases have been identified in these microorganisms. The genomes of three model extreme thermophiles-an archaeon Pyrococcus furiosus (T(opt) = 98 degrees C), and two bacteria, Thermotoga maritima (T(opt) = 80 degrees C) and Caldicellulosiruptor saccharolyticus (T(opt) = 70 degrees C)-encode numerous carbohydrate-active enzymes, many of which have been characterized biochemically in their native or recombinant forms. In addition to their voracious appetite for polysaccharide degradation, polysaccharide production has also been noted for extremely thermophilic fermentative anaerobes; T. maritima generates exopolysaccharides that aid in biofilm formation, a process that appears to be driven by intraspecies and interspecies interactions. PMID:18378602

  7. [Does sea-grass biomass control the density of peracarids (Crustacea: Peracarida) in tropical lagoons?].

    PubMed

    Winfield, Ignacio; Cházaro-Olvera, Sergio; Alvarez, Fernando

    2007-03-01

    We analyzed the time-space variation of the peracarid crustaceans that inhabit seagrasses of the Alvarado Lagoon System, Veracruz, Gulf of Mexico. The organisms were collected from 108 samples in six sites with Ruppia maritima beds (December 1992 to November 1994). The assemblage was composed of 11 species. Eight species of Amphipoda (Hourstonius laguna, Cerapus benthophilus, Apocorophium louisianum, Grandidierella bonnieroides, Leptocheirus rhizophorae, Gammarus mucronatus, Melita longisetosa and Haustorius sp.), one of Isopoda (Cassidinidea ovalis) and two of Tanaidacea (Discapseudes holthuisi and Leptochelia savignyi) were identified. Taxocoenosis, density and biomass of peracarids showed seasonal pulses related to R. maritima biomass, salinity variation, epicontinental affluent and inlets. The species C. ovalis, G. mucronatus, A. louisianum and D. holthuisi were dominant. PMID:18457113

  8. Notes on Lichen Genus Buellia De Not. (lichenized Ascomycetes) from South Korea.

    PubMed

    Joshi, Yogesh; Wang, Xin Yu; Lökös, László; Koh, Young Jin; Hur, Jae-Seoun

    2010-03-01

    Based on a literature survey and assessment of the important features of lichen genus Buellia (spore shape and size, anatomy of the exciple as well as analysis of the lichen substances), the present paper describes four new records of B. maritima, B. polyspora, B. spuria and B. stellulata from South Korea. Among them, B. maritima and B. polyspora are firstly reported in East Asia including in China, the Korean Peninsula and Japan. Brief description of all the new records along with earlier described species placed under genus Amandinea and Hafellia are provided with their distribution and chemistry. A key to all the Buellia species reported so far from South Korea is also provided. PMID:23956628

  9. Effects of ingestion of seeds by sika deer ( Cervus nippon ) and dung presence on their germination in a herbaceous community

    Microsoft Academic Search

    Haruna Ishikawa

    2010-01-01

    In a herbaceous community subjected to continual impacts of sika deer (Cervus\\u000a nippon), I examined the effects of seed ingestion by deer on seeds by comparing the ripening and germination rates of seeds of two\\u000a dominant species, Zoysia japonica and Hydrocotyle maritima, between seeds taken out of fecal pellets (deer-ingested seeds) and mature seeds collected directly from living plants (control

  10. Raster based coastal marsh classification within the Galveston Bay ecosystem, Texas

    E-print Network

    Edwards, Aron Shaun

    2009-05-15

    ), and cattail (Typha sp.) compose the low marsh, marshhay cordgrass (Spartina patens), saltwort (Batis maritima), bushy sea ox-eye daisy (Borrichia frutescens), perennial glasswort (Salicornia virginica), annual seepweed (Suaeda linearis), needlerush (Juncus..., Suaeda linearis, Juncus roemerianus, Distichlis spicata, and Paspalum vaginatum which compose the high marsh Iva frutescens which composes the scrub shrub habitat and Baccharis halimifolia and Spartina spartinae which compose the upland coastal prairie...

  11. Nectar-carbohydrate production and composition vary in relation to nectary anatomy and location within individual flowers of several species of Brassicaceae

    Microsoft Academic Search

    Arthur R. Davis; Jeffrey D. Pylatuik; Joelle C. Paradis; Nicholas H. Low

    1998-01-01

    .   Nectar-carbohydrate production and composition were investigated by high-performance liquid chromatography and enzymology\\u000a in nine species from five tribes of the Brassicaceae. In six species (Arabidopsis thaliana (L.) Heynh., Brassica napus L., B. rapa L., Lobularia maritima (L.) Desv., Raphanus sativus L., Sinapis arvensis L.) that produced nectar from both lateral nectaries (associated with the short stamens) and median nectaries

  12. Leaching requirement and salinity threshold for the yield and agronomic characteristics of halophytes under salt stress

    Microsoft Academic Search

    El-Sayed H. El-Haddad; Maher M. Noaman

    2001-01-01

    An experiment was carried out at Nahshala Farm, north west of Al-Ain City, U.A.E. during the 1998–2000 growing seasons, using six halophytes (Batis maritima, Distichlis spicata, Juncus roemerianus, Paspalum vaginatum, Salicornia bigelovii and Spartina alterniflora) and two levels of leaching fraction (0·25 and 0·50) under three irrigation salinity levels (10, 20, and 40 gL?1) in a randomized complete block design

  13. Measurement of in situ phytoextraction of zinc by spontaneous metallophytes growing on a former smelter site.

    PubMed

    Schwartz, C; Gérard, E; Perronnet, K; Morel, J L

    2001-11-12

    This work was undertaken to measure the in situ phytoextraction of zinc using a former zinc-smelter site where metallophyte plants have been growing for 30 years. The site exhibited a gradient in the total metal concentration in the upper horizon (from 3230 to 8530 mg Zn kg(-1)). Soils were sampled from four different sectors (I-IV), and plant shoots were harvested, identified, their biomass weighed and analysed for zinc. The results showed that three plant species were dominant on the site, including Arabidopsis halleri (cress), Armeria maritima (seathrift), and Arrhenatherum elatius (fromental). A. maritima was the predominant species according to the biomass production on the most polluted sector 1. As the concentration of metals in soils decreased. A. maritima disappeared and A. halleri increased. The biomass of A. elatius was the highest on the less polluted soils. Concentrations in zinc in the aerial parts of plants varied from 73 (sector IV) to 6269 mg kg(-1) DM (sector 1). The concentration of Zn in A. halleri decreased with the decrease in concentration of zinc in soil. Phytoextraction was calculated from the biomass and its concentration of metal. It was at a maximum in sector III with a high contribution of A. halleri and A. elatius and reached 10 kg Zn ha(-1), a promising amount for phytoextraction considering the absence of any agricultural practices. In sector 1, phytoextraction was four times lower despite a 2.6 times higher concentration of Zn in the upper horizon. In conclusion, phytoextraction was strongly dependent on the concentration of the available metal in soils which may limit the growth of plants, and favour tolerant but low biomass plant species such as A. maritima. PMID:11712599

  14. Susceptibility of plant selections to Heterodera schachtii and a race of H. trifolii parasitic on Sugarbeet in The Netherlands

    PubMed Central

    Steele, A. E.; Toxopeus, H.; Heijbroek, W.

    1983-01-01

    Similar host ranges were found for Heterodera schachtii and a race of H. trifolii parasitic on sugarbeet in The Netherlands. Twenty-nine of 41 plant accessions evaluated were susceptible to H. trifolii. Five breeding lines of the interspecific hybrid Beta vulgaris-B. procumbens which are resistant to H. schachtii were highly susceptible to H. trifolii. An accession of B. maritima with partial resistance to H. schachtii was resistant to H. trifolii. PMID:19295803

  15. Selenium Levels in Biota from Irrigation Drainwater Impoundments in the San Joaquin Valley, California

    Microsoft Academic Search

    Douglas A. Barnum; David S. Gilmer

    1988-01-01

    Waterfowl, fish, invertebrates, and plants were collected from impoundments used for evaporating subsurface irrigation drainwater in Kings and Kern counties, California. Specimens were analyzed for trace elements with emphasis on selenium. Dry weight concentrations of total selenium ranged from 2.5 to 17 ?g\\/g in wigeongrass, Ruppia maritima; 7.6 to 30 ?g\\/g in water boatmen, Corixidae; 12 to 40 ?\\/g in

  16. Structural insights into the interaction between the bacterial flagellar motor proteins FliF and FliG

    PubMed Central

    Levenson, Robert; Zhou, Hongjun; Dahlquist, Frederick W.

    2012-01-01

    The binding of the soluble cytoplasmic protein FliG to the transmembrane protein FliF is one of the first interactions in the assembly of the bacterial flagellum. Once established, this interaction is integral in keeping the flagellar cytoplasmic ring, responsible for both transmission of torque and control of the rotational direction of the flagellum, anchored to the central transmembrane ring on which the flagellum is assembled. Here we isolate and characterize the interaction between the N-terminal domain of Thermotoga maritima FliG (FliGN) and peptides corresponding to the conserved C-terminal portion of T. maritima FliF. Using nuclear magnetic resonance and other techniques we show that the last ~40 amino acids of FliF (FliF) interac strongly (upper-bound Kd of low nM) with FliGN. This complex formation causes extensive conformational changes in FliGN. We find that T. maritima FliGN is homodimeric in the absence of FliFC peptide but forms a heterodimeric complex with peptide, and we show that this same change in oligomeric state occurs in full-length T. maritima FliG as well. We relate previously observed phenotypic effects of FliFC mutations to our direct observation of binding. Lastly, based on NMR data we propose that the primary interaction site for FliFC is located on a conserved hydrophobic patch centered along helix 1 of FliGN. These results provide new detailed information about the bacterial flagellar motor and support efforts to understand the cytoplasmic ring’s precise molecular structure and mechanism of rotational switching. PMID:22670715

  17. Part II: defining and quantifying individual and co-cultured intracellular proteomes of two thermophilic microorganisms by GeLC-MS 2 and spectral counting

    Microsoft Academic Search

    David Muddiman; Genna Andrews; Derrick Lewis; Jaspreet Notey; Robert Kelly

    2010-01-01

    Probing the intracellular proteome of Thermotoga maritima and Caldicellulosiruptor saccharolyticus in pure and co-culture affords a global investigation into the machinery and mechanisms enduring inside the bacterial thermophilic\\u000a cell at the time of harvest. The second of a two part study, employing GeLC-MS2 a variety of proteins were confidently identified with <1% false discovery rate, and spectral counts for label-free

  18. Abundance of submerged vascular vegetation in the Rhode River from 1966 to 1973

    Microsoft Academic Search

    Charles H. Southwick; Frank W. Pine

    1975-01-01

    Surveys on the distribution and abundance of submerged vascular plants in the Rhode River showed that there was an irregular\\u000a decline in the amount of vegetation from 1966 to 1973, along with significant changes in species dominance. In 1966, redheadgrass\\u000a (Potamogeton perfoliatus) and Eurasian watermilfoil (Myriophyllum spicatum) were both very abundant with lesser amounts of widgeongrass (Ruppia maritima), horned pondweed

  19. Impact of Electron Beam Irradiation on Fatty Acid Profile of Canavalia Seeds

    Microsoft Academic Search

    Prabhavathi Supriya; Kandikere R. Sridhar; Soora Nareshkumar; Sanjeev Ganesh

    The present study provided an evidence for selective changes of the fatty acid methyl esters (FAMEs) of Canavalia seeds and the low doses of electron beam irradiation (EBI; 2.5 and 5 kGy) serve as hormetic doses for selective enhancement\\u000a of fatty acids. The total lipids and FAMEs of irradiated Canavalia cathartica and Canavalia maritima seeds of the coastal sand dunes of

  20. Vasodilator effects of Diocleinae lectins from the Canavalia genus

    Microsoft Academic Search

    Ana Maria Sampaio Assreuy; Sabrina Rodrigues Fontenele; Alana de Freitas Pires; Débora Costa Fernandes; Natália Velloso Fontenelle C. Rodrigues; Eduardo Henrique Salviano Bezerra; Tales Rocha Moura; Kyria Santiago do Nascimento; Benildo Sousa Cavada

    2009-01-01

    This study investigated and compared vascular actions of leguminous lectins obtained from the Canavalia genus (Canavalia brasiliensis, Canavalia gladiata, and Canavalia maritima) in the rat models of paw edema and isolated aorta. Paw edema was induced by subcutaneous injection of lectins (0.01–1 mg\\/kg)\\u000a in animals pre-treated or not with indomethacin or L-NAME. In isolated aorta, cumulative concentration curves of C. gladiata

  1. The use of TM imagery to monitor the general health of coastal marshes 

    E-print Network

    De Sousa, David Alexandre

    1994-01-01

    ), and ~Ru ia maritima (Widgeon-grass). l t dt t ? ~SMM p t, ~hilt ' p. , E ht hl* p. (Ill t), S~i hill l (E ll ldp), P~) ~it (S h * P pd ), dT~h~d' l (S Ih C ttM(). F h M h ? S~itt l ES!. (h h d), El h ' ES!. (Sp& h), P tdd dt (Plht*)W d). ~Eih ' ~i...

  2. Chromosomenzahlen von Pflanzen der Insel Kuba II

    Microsoft Academic Search

    Reinhard Fritsch

    1972-01-01

    Zusammenfassung Von weiteren 19 Arten der Flora von Kuba wurden die Chromosomenzahlen festgestellt, davon bei 7 Arten zum ersten Mal (Crotalaria maypurensis 2n=16,Canavalia maritima 2n=22,Erythrina cubensis 2n=42,Phyllanthus leonis 2n=ca. 208,Urechites lutea 2n=12,Marsdenia linearis 2n=22 und die folgende Art).Picrodendron macrocarpum hat 2n=48 Chromosomen. Die sich daraus ergebenden Möglichkeiten zum Anschluß der Familie werden diskutiert und auf eine auffallende Übereinstimmung mit den

  3. Nutritional and antinutritional components of Canavalia spp. seeds from the west coast sand dunes of India

    Microsoft Academic Search

    A. B. Arun; K. R. Sridhar; N. S. Raviraja; E. Schmidt; K. Jung

    2003-01-01

    Seeds of two coastal sand dune wild legumes, Canavalia cathartica and Canavalia maritima from the west coast of India were analyzed for their nutritional and antinutritional properties. The seeds contained 35.5 and 34.1% crude protein, 52.8 and 50.5% crude carbohydrates, 1.3 and 1.7% crude lipids and 3.1 and 3.5% ash content, respectively. Among the minerals, potassium was the highest followed

  4. Histamine release induced by glucose (mannose)-specific lectins isolated from Brazilian beans. Comparison with concanavalin A

    Microsoft Academic Search

    J. C. Gomes; R. Rossi Ferreira; B. Sousa Cavada; R. Azevedo Moreira; J. T. A. Oliveira

    1994-01-01

    The histamine releasing properties of glucose (mannose)-specific lectins isolated from Brazilian beans was examined. TheCanavalia brasiliensis, Dioclea rostrata, andDioclea virgata lectins induced histamine release in rat peritoneal mast cells similar to concanavalin A. Less potency and efficacy was observed forCanavalia maritima, Dioclea guianensis, andDioclea violacea while very low activities were seen for the lectins fromDioclea grandiflora, Canavalia bonariensis, andCratylia floribunda.

  5. Analysis of DNA polymorphisms in sugar beet ( Beta vulgaris L.) and development of an SNP-based map of expressed genes

    Microsoft Academic Search

    Katharina Schneider; Dagmar Kulosa; Thomas Rosleff Soerensen; Silke Möhring; Martin Heine; Gregor Durstewitz; Andreas Polley; Eberhard Weber; Jamsari; Jens Lein; Uwe Hohmann; Emma Tahiro; Bernd Weisshaar; Britta Schulz; Georg Koch; Christian Jung; Martin Ganal

    2007-01-01

    A panel of 13 sugar beet lines and one genotype each of the Beta vulgaris cultivars red beet and Swiss chard, and B. vulgaris ssp. maritima were used to identify polymorphisms in alignments of genomic DNA sequences derived from 315 EST- and 43 non-coding RFLP-derived\\u000a loci. In sugar beet lines, loci of expressed genes showed an average SNP frequency of

  6. Niche expansion, body size, and survival in Galápagos marine iguanas

    Microsoft Academic Search

    Martin Wikelski; Peter H. Wrege

    2000-01-01

    Foraging theory predicts that dietary niche breadth should expand as resource availability decreases. However, Galpagos marine\\u000a iguanas often die during algae shortages (El Nios) although land plants abound where they rest and reproduce. On Seymour\\u000a Norte island, a subpopulation of iguanas exhibited unique foraging behavior: they consistently included the succulent beach\\u000a plant B. maritima in their diet. We investigated the

  7. Evaluation of floral resources for enhancement of fitness of Gonatocerus ashmeadi, an egg parasitoid of the glassy-winged sharpshooter, Homalodisca vitripennis

    Microsoft Academic Search

    Nicola A. Irvin; Mark S. Hoddle

    2007-01-01

    The effect of five different food resources (Coccus hesperidum honeydew, honey-water, Lobularia maritima, Fagopyrum esculentum and water only) on the longevity, fecundity, and progeny fitness of female Gonatocerus ashmeadi, an egg parasitoid of the glassy-winged sharpshooter (Homalodisca vitripennis) was investigated in the laboratory. Female G. ashmeadi survived 208–405% longer (up to 11.7 days longer) when fed C. hesperidum honeydew, honey-water,

  8. Evaluation of Xoral resources for enhancement of Wtness of Gonatocerus ashmeadi, an egg parasitoid of the glassy-winged sharpshooter, Homalodisca vitripennis

    Microsoft Academic Search

    Nicola A. Irvin; Mark S. Hoddle

    2007-01-01

    The eVect of Wve diVerent food resources (Coccus hesperidum honeydew, honey-water, Lobularia maritima, Fagopyrum esculentum and water only) on the longevity, fecundity, and progeny Wtness of female Gonatocerus ashmeadi, an egg parasitoid of the glassy-winged sharp- shooter (Homalodisca vitripennis) was investigated in the laboratory. Female G. ashmeadi survived 208-405% longer (up to 11.7 days longer) when fed C. hesperidum honeydew,

  9. The eVect of resource provisioning and sugar composition of foods on longevity of three Gonatocerus spp., egg parasitoids of Homalodisca vitripennis

    Microsoft Academic Search

    Nicola A. Irvin; Mark S. Hoddle; Steven J. Castle

    2007-01-01

    The eVect of dietary supplements on the longevity of male and female Gonatocerus ashmeadi, G. triguttatus and G. fasciatus (Hyme- noptera: Mymaridae), was determined in the laboratory. Treatments included: water only, 3:1 honey-water solution, Xoral and extra- Xoral nectars from Wve diVerent plants (excised stems from Fagopyrum esculentum, Lobularia maritima, Phacelia tanacetifolia, Anethum graveolens and Vicia faba), honeydew from Coccus

  10. The Arabidopsis basic leucine zipper transcription factor AtbZIP24 regulates complex transcriptional networks involved in abiotic stress resistance

    Microsoft Academic Search

    Oksoon Yang; Olga V. Popova; Ulrike Süthoff; Ines Lüking; Karl-Josef Dietz; Dortje Golldack

    2009-01-01

    Soil salinity severely affects plant growth and agricultural productivity. AtbZIP24 encodes a bZIP transcription factor that is induced by salt stress in Arabidopsis thaliana but suppressed in the salt-tolerant relative Lobularia maritima. Transcriptional repression of AtbZIP24 using RNA interference improved salt tolerance in A. thaliana. Under non-stress growth conditions, transgenic A. thaliana lines with decreased AtbZIP24 expression activated the expression

  11. The effect of resource provisioning and sugar composition of foods on longevity of three Gonatocerus spp., egg parasitoids of Homalodisca vitripennis

    Microsoft Academic Search

    Nicola A. Irvin; Mark S. Hoddle; Steven J. Castle

    2007-01-01

    The effect of dietary supplements on the longevity of male and female Gonatocerus ashmeadi, G. triguttatus and G. fasciatus (Hymenoptera: Mymaridae), was determined in the laboratory. Treatments included: water only, 3:1 honey–water solution, floral and extra-floral nectars from five different plants (excised stems from Fagopyrum esculentum, Lobularia maritima, Phacelia tanacetifolia, Anethum graveolens and Vicia faba), honeydew from Coccus hesperidum and

  12. Age-specific, density-dependent and environment-based mortality of a short-lived perennial herb

    Microsoft Academic Search

    F. X. Pico ´; J. Retana

    2008-01-01

    Density-independent and density-dependent processes affect plant mortality. Although less well understood, age-specific mortality can also play an important role in plant mortality. The goal of this study was to analyse sev- eral factors accounting for mortality in the Mediterranean short-lived peren- nial herb Lobularia maritima. We followed three cohorts of plants (from emergence to death) during 4 years in field

  13. Effect of ent -Labdane Diterpenes from Potamogetonaceae on Selenastrum capricornutum and Other Aquatic Organisms

    Microsoft Academic Search

    Tiziana Cangiano; Marina Dellagreca; Antonio Fiorentino; Marina Isidori; Pietro Monaco; Armando Zarrelli

    2002-01-01

    Twenty ent-labdane diterpenes, isolated from the aquatic plants Ruppia maritima and Potamogeton natans, were tested to detect their effects on aquatic organisms from different trophic levels. Toxicity tests were performed on aquatic producers (the alga Selenastrum capricornutum), and consumers including a rotifer (Brachionus calyciflorus), a cladoceran crustacean (Daphnia magna), and two anostracan crustaceans (Thamnocephalus platyurus and Artemia salina). Furano-ent-labdanes exhibited

  14. Structural insights into the interaction between the bacterial flagellar motor proteins FliF and FliG.

    PubMed

    Levenson, Robert; Zhou, Hongjun; Dahlquist, Frederick W

    2012-06-26

    The binding of the soluble cytoplasmic protein FliG to the transmembrane protein FliF is one of the first interactions in the assembly of the bacterial flagellum. Once established, this interaction is integral in keeping the flagellar cytoplasmic ring, responsible for both transmission of torque and control of the rotational direction of the flagellum, anchored to the central transmembrane ring on which the flagellum is assembled. Here we isolate and characterize the interaction between the N-terminal domain of Thermotoga maritima FliG (FliG(N)) and peptides corresponding to the conserved C-terminal portion of T. maritima FliF. Using nuclear magnetic resonance (NMR) and other techniques, we show that the last ~40 amino acids of FliF (FliF(C)) interact strongly (upper bound K(d) in the low nanomolar range) with FliG(N). The formation of this complex causes extensive conformational changes in FliG(N). We find that T. maritima FliG(N) is homodimeric in the absence of the FliF(C) peptide but forms a heterodimeric complex with the peptide, and we show that this same change in oligomeric state occurs in full-length T. maritima FliG, as well. We relate previously observed phenotypic effects of FliF(C) mutations to our direct observation of binding. Lastly, on the basis of NMR data, we propose that the primary interaction site for FliF(C) is located on a conserved hydrophobic patch centered along helix 1 of FliG(N). These results provide new detailed information about the bacterial flagellar motor and support efforts to understand the cytoplasmic ring's precise molecular structure and mechanism of rotational switching. PMID:22670715

  15. A thermodynamic study of mesophilic, thermophilic, and hyperthermophilic l-arabinose isomerases: The effects of divalent metal ions on protein stability at elevated temperatures

    Microsoft Academic Search

    Dong-Woo Lee; Young-Ho Hong; Eun-Ah Choe; Sang-Jae Lee; Seong-Bo Kim; Han-Seung Lee; Jong-Won Oh; Hae-Hun Shin; Yu-Ryang Pyun

    2005-01-01

    To gain insight into the structural stability of homologous homo-tetrameric l-arabinose isomerases (AI), we have examined the isothermal guanidine hydrochloride (GdnHCl)-induced unfolding of AIs from mesophilic Bacillus halodurans (BHAI), thermophilic Geobacillus stearothermophilus (GSAI), and hyperthermophilic Thermotoga maritima (TMAI) using circular dichroism spectroscopy. The GdnHCl-induced unfolding of the AIs can be well described by a two-state reaction between native tetramers and

  16. Part II: defining and quantifying individual and co-cultured intracellular proteomes of two thermophilic microorganisms by GeLC-MS2 and spectral counting.

    PubMed

    Andrews, Genna; Lewis, Derrick; Notey, Jaspreet; Kelly, Robert; Muddiman, David

    2010-09-01

    Probing the intracellular proteome of Thermotoga maritima and Caldicellulosiruptor saccharolyticus in pure and co-culture affords a global investigation into the machinery and mechanisms enduring inside the bacterial thermophilic cell at the time of harvest. The second of a two part study, employing GeLC-MS(2) a variety of proteins were confidently identified with <1% false discovery rate, and spectral counts for label-free relative quantification afforded indication of the dynamic proteome as a function of environmental stimuli. Almost 25% of the T. maritima proteome and 10% of the C. saccharolyticus proteome were identified. Through comparison of growth temperatures for T. maritima, a protein associated with chemotaxis was uniquely present in the sample cultivated at the non-optimal growth temperature. It is suspected that movement was induced due to the non-optimal condition as the organism may need to migrate in the culture to locate more nutrients. The inventory of C. saccharolyticus proteins identified in these studies and attributed to spectral counting, demonstrated that two CRISPR-associated proteins had increased expression in the pure culture versus the co-culture. Further focusing on this relationship, a C. saccharolyticus phage-shock protein was identified in the co-culture expanding a scenario that the co-culture had decreased antiviral resistance and accordingly an infection-related protein was present. Alterations in growth conditions of these bacterial thermophilic microorganisms offer a glimpse into the intricacy of microbial behavior and interaction. PMID:20582400

  17. Studies of Storage Proteins of Higher Plants

    PubMed Central

    Hague, Donald R.

    1975-01-01

    Concanavalin A, the lectin of the Jack bean, Canavalia ensiformis, was extracted and compared with homologous proteins from Canavalia gladiata and Canavalia maritima. All proteins were bound to Sephadex G-100 and eluted from the gel with buffered glucose solution. Quantitative recoveries indicated that large quantities (23 to 28% of dry seed protein) of these lectins are synthesized by all three species. Antibody preparations made against C. ensiformis lectin failed to discriminate among the three proteins; the pattern of the precipitin bands indicated identical antigenic determinants in the Ouchterlony double-diffusion assay. Native and sodium dodecyl sulfate polyacryl-amide gel electrophoresis also failed to distinguish differences in the proteins. The storage protein active in carbohydrate binding is composed, in each case, of identical subunits. However, the amino acid composition of the subunit chains from the three sources is not identical. In particular, the lectins from C. ensiformis and C. gladiata contain two methionine residues per protein subunit, while only one methionine residue is found in the C. martima lectin. Cyanogen bromide cleavage of the purified subunit from C. maritima yieded two fragments with molecular weights estimated at 20,400 and 4,600, respectively. Amino acid analysis of the separated fragments indicated that the methionine residue at position 130 in C. ensiformis is absent in the lectin from C. maritima. Images PMID:16659139

  18. Studies of storage proteins of higher plants: I. Concanavalin a from three species of the genus canavalia.

    PubMed

    Hague, D R

    1975-04-01

    Concanavalin A, the lectin of the Jack bean, Canavalia ensiformis, was extracted and compared with homologous proteins from Canavalia gladiata and Canavalia maritima. All proteins were bound to Sephadex G-100 and eluted from the gel with buffered glucose solution. Quantitative recoveries indicated that large quantities (23 to 28% of dry seed protein) of these lectins are synthesized by all three species. Antibody preparations made against C. ensiformis lectin failed to discriminate among the three proteins; the pattern of the precipitin bands indicated identical antigenic determinants in the Ouchterlony double-diffusion assay. Native and sodium dodecyl sulfate polyacryl-amide gel electrophoresis also failed to distinguish differences in the proteins. The storage protein active in carbohydrate binding is composed, in each case, of identical subunits. However, the amino acid composition of the subunit chains from the three sources is not identical. In particular, the lectins from C. ensiformis and C. gladiata contain two methionine residues per protein subunit, while only one methionine residue is found in the C. martima lectin. Cyanogen bromide cleavage of the purified subunit from C. maritima yieded two fragments with molecular weights estimated at 20,400 and 4,600, respectively. Amino acid analysis of the separated fragments indicated that the methionine residue at position 130 in C. ensiformis is absent in the lectin from C. maritima. PMID:16659139

  19. Activity of select dehydrogenases with Sepharose-immobilized N(6)-carboxymethyl-NAD.

    PubMed

    Beauchamp, Justin; Vieille, Claire

    2015-03-01

    N(6)-carboxymethyl-NAD (N(6)-CM-NAD) can be used to immobilize NAD onto a substrate containing terminal primary amines. We previously immobilized N(6)-CM-NAD onto sepharose beads and showed that Thermotoga maritima glycerol dehydrogenase could use the immobilized cofactor with cofactor recycling. We now show that Saccharomyces cerevisiae alcohol dehydrogenase, rabbit muscle L-lactate dehydrogenase (type XI), bovine liver L-glutamic dehydrogenase (type III), Leuconostoc mesenteroides glucose-6-phosphate dehydro-genase, and Thermotoga maritima mannitol dehydrogenase are active with soluble N(6)-CM-NAD. The products of all enzymes but 6-phospho-D-glucono-1,5-lactone were formed when sepharose-immobilized N(6)-CM-NAD was recycled by T. maritima glycerol dehydrogenase, indicating that N(6)-immobilized NAD is suitable for use by a variety of different dehydrogenases. Observations of the enzyme active sites suggest that steric hindrance plays a greater role in limiting or allowing activity with the modified cofactor than do polarity and charge of the residues surrounding the N(6)-amine group on NAD. PMID:25611453

  20. Screening of common Plantago species in Hungary for bioactive molecules and antioxidant activity.

    PubMed

    Gonda, S; Tóth, L; Parizsa, P; Nyitrai, M; Vasas, G

    2010-01-01

    Five species of Plantago genus, namely P. lanceolata, P. major, P. media, P. altissima and P. maritima were screened for iridoid content (CE-MEKC), total caffeoyl phenylethanoid glycoside (CPG) content and antioxidant activity (CUPRAC assay). The five species could be distinguished by TLC pattern analysis in a single run in a system commonly used for quality management of P. lanceolata leaves, as shown by cluster analysis of major bands; with the exception, that P. altissima and P. lanceolata did not show enough pattern difference to be fully separated. P. maritima was shown to have the highest antioxidant capacity (0.42 ?mol ascorbic acid equivalent (AAE)/g DW), and the highest level of CPGs (4.29%). P. altissima was shown to be chemically indistinguishable from P. lanceolata with repsect to iridoid content (aucubin 0.55 ± 0.04%, 0.68 ± 0.23%, catalpol 0.66 ± 0.13% and 0.89 ± 0.22%, respectively), CPG content (2.40 ± 0.38% and 2.54 ± 0.56%, respectively) and antioxidant capacity (0.2206 ± 0.0290 and 0.2428 ± 0.0191 ?mol AAEAC/g DW). The presented data show the potency of medicinal use of Hungarian wild populations of the studied five species, especially in the case of P. maritima, and that P. altissima can be a potential replacement of P. lanceolata in herbal mixtures. PMID:21565762

  1. Anatomical and ultrastructural adaptations of seagrass leaves: an evaluation of the southern Atlantic groups.

    PubMed

    Ferreira, Chirle; Horta, Paulo A; Almeida, Gabriela M; Zitta, Carmen S; de M Oliveira, Eliana; Gueye, Marietou B Y B; Rodrigues, Ana C

    2015-01-01

    Seagrasses, which form an integral part of the worldwide coastal habitat, are considered highly relevant from an ecological point of view. Due to the scarcity of anatomical information, the present study analyzed the morphoanatomy, histochemistry, and ultrastructure of Halophila decipiens, Halodule wrightii, and Ruppia maritima leaves, discussing their adaptations to the marine environments observed throughout the southwestern tropical and subtropical Atlantic coast. The leaves of these three species feature a uniseriate epidermis with the presence of chloroplasts in large quantities and absence of stomata. The vascular system consists of a central vascular bundle with sieve tube elements of the phloem and protoxylem lacunae, as well as small vascular bundles near the leaf margins. The leaves of H. decipiens possess trichomes, but no mesophyll in the leaf margins. The mesophyll of H. wrightii and R. maritima is homogeneous with chlorenchyma cells and air lacunae scattered throughout the leaf. The histochemistry analysis revealed the absence of amyloplasts and the presence of proteins in the outer periclinal walls of ordinary epidermal cells of the three species. It was also possible to detect the presence of idioblasts containing phenolic compounds in H. decipiens and R. maritima. The ultrastructural analysis of the three species revealed many elliptical chloroplasts, with organized thylakoids, expansion of the epidermal cell wall into the cytoplasm, and a thin cuticle. Hydropoten were also observed in the three specimens. The results show that the species analyzed have important adaptations which enable their survival in the marine environment. PMID:24893589

  2. Salt marsh vegetation as a carbonyl sulfide (COS) source to the atmosphere

    NASA Astrophysics Data System (ADS)

    Whelan, Mary E.; Min, Dong-Ha; Rhew, Robert C.

    2013-07-01

    Carbonyl sulfide (COS) is the most abundant and longest-lived reduced sulfur compound in the atmosphere; changes in its atmospheric concentration could significantly affect global climate and the biogeochemical sulfur cycle. The largest sink of COS in the troposphere is its destruction in plant leaves by the enzymes involved in photosynthesis. In this study, net fluxes of COS were measured from a coastal salt marsh on a subtropical barrier island on the Texas shore of the Gulf of Mexico. We find net emissions from sites with the common salt marsh plant Batis maritima compared to the net uptake from vegetated plots of most previously investigated biomes. The magnitude of the COS production from vegetated plots in this study was twice the emissions of soil-only salt marsh plots. This is the first time that emissions of COS have been found to be significantly enhanced by the presence of vegetation compared to soil alone. COS fluxes exceeded +110 pmol m-2 s-1 for non-inundated plots during daytime hours and were correlated with soil temperature at the depth of 5 cm. Tidal flooding inhibited soil COS exchange; however, we found continued net emissions from emergent B. maritima. This study suggests that emissions of COS resulted from interactions with the plants themselves, which would mean that B. maritima can mediate the production of atmospheric COS.

  3. A floral-derived compound attractive to the tephritid fruit fly parasitoid Diachasmimorpha longicaudata (Hymenoptera: Braconidae).

    PubMed

    Rohrig, Eric; Sivinski, John; Teal, Peter; Stuhl, Charles; Aluja, Martin

    2008-04-01

    Many adult hymenopteran parasitoids, even host-feeding species, consume the nectar of flowering plants. Previous field studies had identified plants attractive (Lobularia maritima L.) and unattractive (Spermacoce verticillata L) to certain opiine braconids (Hymenoptera). Under laboratory conditions, Diachasmimorpha longicaudata (Ashmead), a parasitoid of tephritid fruit fly larvae and representative opiine, responded in flight tunnels to L. maritima but not to S. verticillata. Volatile chemicals of the two flowers were collected and analyzed by using capillary gas liquid chromatography and mass spectral analysis. Acetophenone was isolated from L. maritima but not from S. verticillata. In flight tunnels, D. longicaudata were exposed to 10 concentrations (doses) of acetophenone. Female parasitoids showed a significant attraction to several acetophenone doses, with concentrations of 25 and 50 ng the most attractive. No odor source, either floral or floral-derived, was attractive to male parasitoids. Reliable trapping systems for parasitoid species, particularly species such as D. longicaudata used for augmentative biological control, would be a valuable monitoring tool. At present, there are few, if any, florally derived synthetic lures for attracting hymenopteran parasitoids. PMID:18343976

  4. Immunocytochemical distribution of pigment-dispersing hormone in the cephalic ganglia of polyneopteran insects.

    PubMed

    Sehadová, H; Sauman, I; Sehnal, F

    2003-04-01

    Material detectable with antisera to the pigment-dispersing hormone (PDH) is regarded as a component of the circadian clock residing in some insects in the optic lobe. This paper demonstrates that the position of the PDH-positive neurones and the course of their processes are similar in all representatives of the insect cohort Polyneoptera. A basic morphological pattern, which includes the proximal frontoventral (Pfv), distal posteriodorsal (Dpd) and posterioventral (Dpv) clusters of PDH-positive neurones, was found in the examined species of locusts, crickets, walking sticks, cockroaches, earwigs and termites. The Pfv cluster is located close to the accessory medulla and usually consists of a set of smaller and a set of larger perikarya. The Dpd and Dpv clusters occupy a dorsal and a ventral position, respectively, at the distal edge of the medulla. These clusters are lacking in stonefly and praying mantid species. The fan-like arrangement of PDH-positive fibres within the frontal medulla face (the locusts and the praying mantid have an additional, smaller fan on the posterior medulla face) is another characteristic feature of Polyneoptera. One (two in the locusts and the praying mantid) nerve bundle runs from the optic lobe to the lateral protocerebrum where it ramifies. One branch gives rise to a fibre network frontally encircling brain neuropile in the area of mushroom bodies. One thin fibre in the crickets and the earwig, and several thicker and anastomosing fibres in the other insects, connect the brain hemispheres. The arrangement of other PDH-positive structures specifies taxa within Polyneoptera. Specific features comprise the presence of PDH-positive perikarya in protocerebrum (walking stick and termite), deutocerebrum (cricket, walking stick, and one cockroach species), tritocerebrum (another cockroach species), and the suboesophageal ganglion (cricket, walking stick and termite). In the walking stick and the termite, PDH-positive fibres pass from the cephalic to the frontal ganglion and from there via the recurrent nerve to the corpora cardiaca where they make varicosities indicative of peptide release into the haemolymph. PMID:12712321

  5. Iminosugar glycosidase inhibitors: structural and thermodynamic dissection of the binding of isofagomine and 1-deoxynojirimycin to beta-glucosidases.

    PubMed

    Zechel, David L; Boraston, Alisdair B; Gloster, Tracey; Boraston, Catherine M; Macdonald, James M; Tilbrook, D Matthew G; Stick, Robert V; Davies, Gideon J

    2003-11-26

    The design and synthesis of transition-state mimics reflects the growing need both to understand enzymatic catalysis and to influence strategies for therapeutic intervention. Iminosugars are among the most potent inhibitors of glycosidases. Here, the binding of 1-deoxynojirimycin and (+)-isofagomine to the "family GH-1" beta-glucosidase of Thermotoga maritima is investigated by kinetic analysis, isothermal titration calorimetry, and X-ray crystallography. The binding of both of these iminosugar inhibitors is driven by a large and favorable enthalpy. The greater inhibitory power of isofagomine, relative to 1-deoxynojirimycin, however, resides in its significantly more favorable entropy; indeed the differing thermodynamic signatures of these inhibitors are further highlighted by the markedly different heat capacity values for binding. The pH dependence of catalysis and of inhibition suggests that the inhibitory species are protonated inhibitors bound to enzymes whose acid/base and nucleophile are ionized, while calorimetry indicates that one proton is released from the enzyme upon binding at the pH optimum of catalysis (pH 5.8). Given that these results contradict earlier proposals that the binding of racemic isofagomine to sweet almond beta-glucosidase was entropically driven (Bülow, A. et al. J. Am. Chem. Soc. 2000, 122, 8567-8568), we reinvestigated the binding of 1-deoxynojirimycin and isofagomine to the sweet almond enzyme. Calorimetry confirms that the binding of isofagomine to sweet almond beta-glucosidases is, as observed for the T. maritima enzyme, driven by a large favorable enthalpy. The crystallographic structures of the native T. maritima beta-glucosidase, and its complexes with isofagomine and 1-deoxynojirimycin, all at approximately 2.1 A resolution, reveal that additional ordering of bound solvent may present an entropic penalty to 1-deoxynojirimycin binding that does not penalize isofagomine. PMID:14624580

  6. Genes for the major structural components of Thermotogales species' togas revealed by proteomic and evolutionary analyses of OmpA and OmpB homologs

    SciTech Connect

    Petrus, Amanda K.; Swithers, Kristen S.; Ranjit, Chaman R.; Wu, Si; Brewer, Heather M.; Gogarten, J Peter; Pasa-Tolic, Ljiljana; Noll, Kenneth M.

    2012-06-29

    The unifying structural characteristic of members of the bacterial order Thermotogales is an unusual cell envelope that includes a loose-fitting sheath around each cell, often called a toga. Only two toga-associated structural proteins have been identified in Thermotoga maritima: the anchor protein OmpA1 (previously termed Omp?) and the porin OmpB (previously termed Omp?). The gene encoding OmpA (ompA1) was assigned in the genome sequence to TM0477, but because no peptide sequence was available for OmpB, its gene (ompB) was not annotated. Here we identify the ompB gene as TM0476, determined by LC/MS/MS analysis of the native OmpB protein purified from T. maritima cells. The purified Omp? had ?-sheet secondary structure as determined by circular dichroism. Analysis of the sequence of ompB product shows it has porin characteristics including a carboxy terminus anchoring motif and a porin-specific amino acid composition. Orthologs of ompB were found in the genomes of some, but not all, Thermotogales. Those without orthologs have putative analogs. Phylogenetic analyses of OmpA1 revealed that each species of the Thermotogales has one to three OmpA homologs. T. maritima has two OmpA homologs, encoded by ompA1(TM0477) and ompA2 (TM1729), both of which were found in the toga protein-enriched cell extracts. These annotations of the genes encoding toga structural proteins will guide future examinations of the structure and function of this unusual lineage-defining cell sheath.

  7. Requiem for an eastern Pacific seagrass bed.

    PubMed

    Cortés, J

    2001-12-01

    Few papers concerning seagrasses of the eastern Pacific have been published. This paper presents the first ecological data on the seagrass, Ruppia maritima, from a non-lagoonal setting in the eastern Pacific. A 5000 m2 patch formed by R. maritima, at Playa Iguanita, Bahía Culebra, Pacific coast of Costa Rica was studied. Plant density and leaf length of R. maritima were determined along two transects on different dates. Above and below ground biomass were calculated along one transect. Plant density ranged from 1590 to 8630 individuals m(-2) along the two transects, with means of 5990 +/- 1636 and 6100 +/- 1876 plants m(-2) for transect 1 and 2, respectively. Longest leaf length per plant varied between 0.5 and 23.0 cm. Leaf biomass (LB) ranged from 10 to 97 gm(-2), and root-rhizome biomass (RB) from 31 to 411 gm(-2), resulting in RB:LB ratios of 3.07 to 15.27. Total biomass at Bahía Culebra was lower than at tropical lagoons on the Pacific coast of Mexico, but higher than in the Gulf of Mexico. The below ground: above ground biomass ratio was much higher at Bahía Culebra than at other sites on the Pacific coast of Mexico and the Gulf of Mexico. Another seagrass present at Bahía Culebra was Halophila baillonii, with low densities on the deepest section of the patch. At least 44 invertebrate species associated with the seagrass bed have also been identified. The patch at Playa Iguanita and other sites within Bahía Culebra, as well as their associated organisms, disappeared after a severe storm in June 1996. No seagrasses have been found in the area or in any other location on the Pacific coast of Costa Rica since then. PMID:15264541

  8. Prokaryotes in salt marsh sediments of Ria de Aveiro: Effects of halophyte vegetation on abundance and diversity

    NASA Astrophysics Data System (ADS)

    Oliveira, Vanessa; Santos, Ana L.; Aguiar, Claúdia; Santos, Luisa; Salvador, Ângelo C.; Gomes, Newton C. M.; Silva, Helena; Rocha, Sílvia M.; Almeida, Adelaide; Cunha, Ângela

    2012-09-01

    The aim of this study was to investigate the influence of monospecific colonization of sediment stands by Spartina maritima or Halimione portulacoides on benthic prokaryote assemblages in a salt marsh located in Ria de Aveiro (Portugal). The distribution of Bacteria, Archaea and sulfate-reducing bacteria (SRB) in sediments with monospecific plant stands and in unvegetated sediments was characterized by Fluorescence In Situ Hybridization (FISH). Total prokaryote abundance (0.4 × 109-1.7 × 109 cells gdw-1) was highest in sediments from the surface layer. The domain Bacteria comprised approximately 40% of total prokaryote communities with the highest percentages occurring in the surface layer. Archaeal cells corresponded to an average of 25% of total prokaryote population, with higher abundance in the vegetation banks, and displaying homogeneous vertical distribution. The relative abundance of SRB represented approximately 3% of total 4', 6-diamidino-2-phenylindole dihydrochloride (DAPI) stained cells at unvegetated sediment and H. portulacoides stand and 7% at S. maritima stand. Headspace solid-phase microextraction (HS-SPME) combined with Comprehensive Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectrometry (GC × GC-ToFMS) was used to analyse the volatile and semi-volatile fraction of root exudates. A total of 171 compounds were identified and Principal Component Analysis showed a clear separation between the chemical composition (volatile and semi-volatile organic compounds) of the exudates of the two plants. The patterns of vertical distribution and differences in the proportion of SRB and Archaea in the prokaryote communities developing in sediments colonized by Spartina maritima or Halimione portulacoides suggest the existence of plant-specific interactions between halophyte vegetation and estuarine sediment bacteria in Ria de Aveiro salt marshes, exerted via sediment lithology and root-derived exudates.

  9. Recombinant expression and purification of "virus-like" bacterial encapsulin protein cages.

    PubMed

    Rurup, W Frederik; Cornelissen, Jeroen J L M; Koay, Melissa S T

    2015-01-01

    Ultracentrifugation, particularly the use of sucrose or cesium chloride density gradients, is a highly reliable and efficient technique for the purification of virus-like particles and protein cages. Since virus-like particles and protein cages have a unique size compared to cellular macromolecules and organelles, the rate of migration can be used as a tool for purification. Here we describe a detailed protocol for the purification of recently discovered virus-like assemblies called bacterial encapsulins from Thermotoga maritima and Brevibacterium linens. PMID:25358773

  10. On salt marsh vegetation in North Korea

    Microsoft Academic Search

    Ji?í Kolbek; Ji?í Dostálek; Ivan Jarolímek; Ivan Ostrý; Li Sek-Ha

    1989-01-01

    The salt marsh vegetation on the west coast of North Korea was studied by the method of the Zürich-Montpellier school. The\\u000a following communities were distinguished:Suaedetum japonicae, Scirpetum iseensis, Artemisietum fukudo, and the following were described as new:Triglochini maritimae-Phragmitetum communis, Artemisio capillaris-Salsoletum komarovii andSalsolo komarovii-Rosetum rugosae. The phytocoenological material was also analysed by means of numerical techniques.\\u000a \\u000a The population density ofSuaeda

  11. Valve, compressor contracts awarded for Western Hemisphere projects

    SciTech Connect

    NONE

    1998-01-19

    Major valve and compressor contracts have been let for projects in the Western Hemisphere. Petrobras has awarded Nuovo Pignone, Florence, a $10.5 million contract to supply 400 valves for the 1,975-mile natural-gas pipeline being constructed from Bolivia into Brazil. Additionally, Brazilian company Maritima Petroleo and TransCanada PipeLines Ltd., Calgary, have awarded Nuovo Pignone separate contracts to supply turbocompressor packages. The Brazilian contract is for offshore Campos Basin; the Canadian, for a major expansion of TCPL`s system delivering natural gas out of Alberta. The paper discusses the Bolivia-Brazil pipeline, compressor orders, and the companies.

  12. Variations in Leaf Soluble Amino Acids and Ammonium Content in Subtropical Seagrasses Related to Salinity Stress 1

    PubMed Central

    Pulich, Warren M.

    1986-01-01

    A survey of leaf soluble amino acids was conducted for four subtropical seagrasses grown at several salinities. Proline functioned as an organic osmoticum in Halodule wrightii Aschers., Thallasia testudinum Banks ex Koenig, and Ruppia maritima L., while alanine functioned in an osmoregulatory capacity in Halophila engelmanni Aschers. When light-and salinity-induced variations in leaf NH4 and amide-N levels were compared in Halodule, Thalassia, and Halophila, ability to regulate leaf NH4 levels was correlated with osmoregulatory capacity and maintenance of selected amino acid contents. PMID:16664600

  13. Effect of ent-labdane diterpenes from Potamogetonaceae on Selenastrum capricornutum and other aquatic organisms.

    PubMed

    Cangiano, Tiziana; Dellagreca, Marina; Fiorentino, Antonio; Isidori, Marina; Monaco, Pietro; Zarrelli, Armando

    2002-06-01

    Twenty ent-labdane diterpenes, isolated from the aquatic plants Ruppia maritima and Potamogeton natans, were tested to detect their effects on aquatic organisms from different trophic levels. Toxicity tests were performed on aquatic producers (the alga Selenastrum capricornutum), and consumers including a rotifer (Brachionus calyciflorus), a cladoceran crustacean (Daphnia magna), and two anostracan crustaceans (Thamnocephalusplatyurus and Artemia salina). Furano-ent-labdanes exhibited high toxicity toward all of these organisms. 15,16-Epoxy-12(S)-hydroxy-8(17),13(16),14-ent-labdatrien-20.19-olide had a high toxicity only toward the algae and the rotifers. It was inactive for the crustaceans. PMID:12184390

  14. Variations in leaf soluble amino acids and ammonium content in subtropical seagrasses related to salinity stress.

    PubMed

    Pulich, W M

    1986-01-01

    A survey of leaf soluble amino acids was conducted for four subtropical seagrasses grown at several salinities. Proline functioned as an organic osmoticum in Halodule wrightii Aschers., Thallasia testudinum Banks ex Koenig, and Ruppia maritima L., while alanine functioned in an osmoregulatory capacity in Halophila engelmanni Aschers. When light-and salinity-induced variations in leaf NH(4) and amide-N levels were compared in Halodule, Thalassia, and Halophila, ability to regulate leaf NH(4) levels was correlated with osmoregulatory capacity and maintenance of selected amino acid contents. PMID:16664600

  15. Acylated cyanidin 3-sambubioside-5-glucosides in three garden plants of the Cruciferae

    Microsoft Academic Search

    Fumi Tatsuzawa; Norio Saito; Koichi Shinoda; Atsushi Shigihara; Toshio Honda

    2006-01-01

    Seven acylated cyanidin 3-sambubioside-5-glucosides were isolated from the flowers of three garden plants in the Cruciferae. Specifically, four pigments were isolated from Lobularia maritima (L.) Desv., together with a known pigment, as well as, three pigments from Lunaria annua L., and two known pigments from Cheiranthus cheiri L. These pigments were determined to be cyanidin 3-O-[2-O-((acyl-II)-(?-d-xylopyranosyl))-6-O-(acyl-I)-?-d-glucopyranoside]-5-O-[6-O-(acyl-III)-?-d-glucopyranoside], in which the acyl-I

  16. Ability of salt marsh plants for TBT remediation in sediments

    Microsoft Academic Search

    Pedro N. Carvalho; M. Clara P. Basto; Manuela F. G. M. Silva; Ana Machado; A. A. Bordalo; M. Teresa S. D. Vasconcelos

    2010-01-01

    Introduction  The capability of Halimione portulacoides, Spartina maritima, and Sarcocornia fruticosa (halophytes very commonly found in salt marshes from Mediterranean areas) for enhancing remediation of tributyltin (TBT)\\u000a from estuarine sediments was investigated, using different experimental conditions.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  The influence of H. portulacoides on degradation of the butyltin compounds was assessed in two different ways: (1) a 9-month ex situ study carried out

  17. Screening seeds of Scottish plants for antibacterial activity.

    PubMed

    Kumarasamy, Yashodharan; Cox, Philip John; Jaspars, Marcel; Nahar, Lutfun; Sarker, Satyajit Dey

    2002-11-01

    Based on ethnopharmacological and taxonomic information, seeds of 21 Scottish plant species from 14 different families were obtained from authentic seed suppliers. Their n-hexane, dichloromethane and methanol extracts were assessed for antibacterial activity against 11 pathogenic bacterial species. Methanol extracts of 11 plant species showed significant antibacterial activity. Malva moschata and Prunus padus were active against five bacterial species, Reseda lutea against four, Centaurium erythraea and Crithmum maritimum against three, Calluna vulgaris against two, and Armeria maritima, Centaurea scabiosa, Daucus carota, Rosa canina and Stellaria holostea against one bacterial species. C. erythraea and P. padus were also active against methicillin resistant Staphylococcus aureus. PMID:12413709

  18. Yeasts isolated from plant-associated beetles and other insects: seven novel Candida species near Candida albicans.

    PubMed

    Suh, Sung-Oui; Nguyen, Nhu H; Blackwell, Meredith

    2008-02-01

    Yeasts related to Candida albicans were isolated from the digestive tracts of beetles in eight families and various orders of insects such as earwigs, crickets, and roaches, most of which were caught at light traps or in a few cases directly from plant materials. Based on comparisons of DNA sequences and other taxonomic characteristics, a total of 41 isolates were identified as Candida orthopsilosis, Candida pseudorhagii, Candida maltosa, Candida parapsilosis, Candida tropicalis, Candida neerlandica, Lodderomyces elongisporus, and seven new Candida species. The new species and type strains are designated as Candida gigantensis NRRL Y-27736T, Candida bohiensis NRRL Y-27737T, Candida alai NRRL Y-27739T, Candida buenavistaensis NRRL Y-27734T, Candida frijolesensis NRRL Y-48060T, Candida labiduridarum NRRL Y-27940T, and Candida tetrigidarum NRRL Y-48142T. A phylogeny based on SSU and LSU rRNA gene sequences indicated that most of the new species were closely related to members of the C. albicans/L. elongisporus clade, such as C. albicans, Candida dulbliniensis, C. neerlandica, Candida chauliodes, and Candida corydali. Candida alai was placed near this clade, but no closely related sister taxon was identified. The ecology of the insect-associated yeasts is discussed and compared with the results from other studies. PMID:17986254

  19. Insect phylogenomics: results, problems and the impact of matrix composition

    PubMed Central

    Letsch, Harald O.; Meusemann, Karen; Wipfler, Benjamin; Schütte, Kai; Beutel, Rolf; Misof, Bernhard

    2012-01-01

    In this study, we investigated the relationships among insect orders with a main focus on Polyneoptera (lower Neoptera: roaches, mantids, earwigs, grasshoppers, etc.), and Paraneoptera (thrips, lice, bugs in the wide sense). The relationships between and within these groups of insects are difficult to resolve because only few informative molecular and morphological characters are available. Here, we provide the first phylogenomic expressed sequence tags data (‘EST’: short sub-sequences from a c(opy) DNA sequence encoding for proteins) for stick insects (Phasmatodea) and webspinners (Embioptera) to complete published EST data. As recent EST datasets are characterized by a heterogeneous distribution of available genes across taxa, we use different rationales to optimize the data matrix composition. Our results suggest a monophyletic origin of Polyneoptera and Eumetabola (Paraneoptera + Holometabola). However, we identified artefacts of tree reconstruction (human louse Pediculus humanus assigned to Odonata (damselflies and dragonflies) or Holometabola (insects with a complete metamorphosis); mayfly genus Baetis nested within Neoptera), which were most probably rooted in a data matrix composition bias due to the inclusion of sequence data of entire proteomes. Until entire proteomes are available for each species in phylogenomic analyses, this potential pitfall should be carefully considered. PMID:22628473

  20. Parent-offspring conflict and the genetic trade-offs shaping parental investment.

    PubMed

    Kölliker, Mathias; Boos, Stefan; Wong, Janine W Y; Röllin, Lilian; Stucki, Dimitri; Raveh, Shirley; Wu, Min; Meunier, Joël

    2015-01-01

    The genetic conflict between parents and their offspring is a cornerstone of kin selection theory and the gene-centred view of evolution, but whether it actually occurs in natural systems remains an open question. Conflict operates only if parenting is driven by genetic trade-offs between offspring performance and the parent's ability to raise additional offspring, and its expression critically depends on the shape of these trade-offs. Here we investigate the occurrence and nature of genetic conflict in an insect with maternal care, the earwig Forficula auricularia. Specifically, we test for a direct response to experimental selection on female future reproduction and correlated responses in current offspring survival, developmental rate and growth. The results demonstrate genetic trade-offs that differ in shape before and after hatching. Our study not only provides direct evidence for parent-offspring conflict but also highlights that conflict is not inevitable and critically depends on the genetic trade-offs shaping parental investment. PMID:25880586

  1. Sea Surface Temperature Products and Research Associated with GHRSST

    NASA Astrophysics Data System (ADS)

    Kaiser-Weiss, A. K.; Minnett, P. J.; Kaplan, A.; Wick, G. A.; Castro, S.; Llewellyn-Jones, D.; Merchant, C.; LeBorgne, P.; Beggs, H.; Donlon, C. J.

    2012-03-01

    GHRSST serves its user community through the specification of operational Sea Surface Temperature (SST) products (Level 2, Level 3 and Level 4) based on international consensus. Providers of SST data from individual satellites create and deliver GHRSST- compliant near-real time products to a global GHRSST data assembly centre and a long-term stewardship facility. The GHRSST-compliant data include error estimates and supporting data for interpretation. Groups organised within GHRSST perform research on issues relevant to applying SST for air-sea exchange, for instance the Diurnal Variability Working Group (DVWG) analyses the evolution of the skin temperature. Other GHRSST groups concentrate on improving the SST estimate (Estimation and Retrievals Working Group EARWiG) and on improving the error characterization, (Satellite SST Validation Group, ST- VAL) and on improving the methods for SST analysis (Inter-Comparison Technical Advisory Group, IC- TAG). In this presentation we cover the data products and the scientific activities associated with GHRSST which might be relevant for investigating ocean- atmosphere interactions.

  2. Arbuscular mycorrhizas in coastal sand dunes of the Paraguaná Peninsula, Venezuela.

    PubMed

    Alarcón, C; Cuenca, G

    2005-12-01

    Arbuscular mycorrhizal colonization was measured in the most abundant plant species of the Paraguaná Peninsula, northwestern Venezuela. These plant species included: Acacia tortuosa, Argusia gnaphalodes, Croton punctatus, Croton rhamnifolius, Egletes prostrata, Melochia tomentosa, Panicum vaginatum, Scaevola plumieri, Sporobolus virginicus, Suriana maritima, Leptothrium rigidum, and Fimbristylis cymosa. Mycorrhizal colonization was assessed using the Trouvelot et al. (1986) method that allows for simultaneous evaluation of frequency of colonization (%F), intensity of colonization (%M), and the proportion of arbuscules (%A) and vesicles (%V) present in the roots. Average frequency of colonization was 69%. The highest frequency of colonization was around 92% in C. rhamnifolius and A. tortuosa; in the other species, it varied from 49 to 86%. L. rigidum and F. cymosa were considered nonmycorrhizal because its colonization was very scarce and at all times appeared without arbuscules. Average intensity of colonization was 7%. The highest intensity of colonization was 18% in C. rhamnifolius. In the other species, it varied from 3 to 15%. Paspalum vaginatum, A. gnaphalodes, M. tomentosa, and S. maritima had their fungal structures tightly packed in modified little ovoid roots. In general, frequency of AM colonization was high and similar to those reported for other tropical ecosystems, whereas the intensity of AM colonization was low and similar to values obtained in analogous studies in disturbed ecosystems. PMID:16007471

  3. Light–dark O2 dynamics in submerged leaves of C3 and C4 halophytes under increased dissolved CO2: clues for saltmarsh response to climate change

    PubMed Central

    Duarte, B.; Santos, D.; Silva, H.; Marques, J. C.; Caçador, I.; Sleimi, N.

    2014-01-01

    Waterlogging and submergence are the major constraints to which wetland plants are subjected, with inevitable impacts on their physiology and productivity. Global warming and climate change, as driving forces of sea level rise, tend to increase such submersion periods and also modify the carbonate chemistry of the water column due to the increased concentration of CO2 in the atmosphere. In the present work, the underwater O2 fluxes in the leaves of two abundant Mediterranean halophytes were evaluated at different levels of dissolved CO2. Photosynthetic enhancement due to increased dissolved CO2 was confirmed for both Halimione portulacoides and Spartina maritima, probably due to high tissue porosity, formation of leaf gas films and reduction of the oxygenase activity of Rubisco. Enhancement of the photosynthetic rates in H. portulacoides and S. maritima was concomitant with an increase in energy trapping and transfer, mostly due to enhancement of the carboxylation reaction of Rubisco, leading to a reduction of the energy costs for carbon fixation. Transposing these findings to the ecosystem, and assuming increased dissolved CO2 concentration scenarios, the halophyte community displays a new ecosystem function, increasing the water column oxygenation and thus reinforcing their role as principal primary producers of the estuarine system. PMID:25381259

  4. The functional exchangeability of pk- and k-turns in RNA structure

    PubMed Central

    Daldrop, Peter; Masquida, Benoît; Lilley, David M.J.

    2013-01-01

    Ribonuclease P RNA requires a sharply kinked RNA helix to make a loop-receptor interaction that creates the binding site for the substrate. In some forms of the ribozyme, this is accomplished by a k-turn, while others have a different element called the pk-turn. The structure of the pk-turn in RNase P of Thermotoga maritima is globally very similar to a k-turn, but lacks all the standard features of that structure, including long-range hydrogen bonds between the two helical arms. We show here that in an isolated RNA duplex, the pk-turn fails to adopt a tightly kinked structure, but rather is a flexible element. This suggests that the tertiary contacts of RNase P assist its folding into the required kinked structure. We find that we can replace the k-turn of the SAM-I riboswitch with the pk-turn, such that the resulting RNA retains its ability to bind SAM, although with lower affinity. We also find that we can replace the pk-turn of T. maritima RNase P with a standard k-turn (in either orientation) with retention of ribozyme activity. Thus, although the pk-turn cannot intrinsically fold into the kinked structure, it can be induced to fold correctly in context. And the pk-turn and k-turns can substitute functionally for one another. PMID:23364423

  5. Phylogeny, biogeography and evolution of Triglochin L. (Juncaginaceae)--morphological diversification is linked to habitat shifts rather than to genetic diversification.

    PubMed

    von Mering, Sabine; Kadereit, Joachim W

    2015-02-01

    A species-level phylogeny is presented for Triglochin, the largest genus of Juncaginaceae (Alismatales) comprising about 30 species of annual and perennial herbs. Triglochin has an almost cosmopolitan distribution with Australia as centre of species diversity. Trans-Atlantic and trans-African disjunctions exist in the genus. Phylogenetic analyses were conducted based on molecular data obtained from nuclear (ITS, internal transcribed spacer) and chloroplast sequence data (psbA-trnH spacer, matK gene). Based on the phylogeny of the group divergence times were estimated and ancestral distribution areas reconstructed. Our data confirm the monophyly of Triglochin and resolve relationships between the major lineages of the genus. The sister group relationship between the Mediterranean/African T. bulbosa complex and the American T. scilloides (formerly Lilaea s.) is strongly supported. This clade is sister to the rest of the genus which contains two main clades. In the first, the widespread T. striata is sister to a clade comprising annual Triglochin species from Australia. The second clade comprises T. palustris as sister to the T. maritima complex, of which the latter is further divided into a Eurasian and an American subclade. Taxonomic diversity in some clades appears to be linked to habitat shifts and is not present in old but ecologically invariable lineages such as the non-monophyletic T. maritima. Diversification in Triglochin began in the Miocene or Oligocene, and most disjunctions in Triglochin were dated to the Miocene. PMID:25450100

  6. Stable carbon isotope fractionation by acetotrophic sulfur-reducing bacteria.

    PubMed

    Goevert, Dennis; Conrad, Ralf

    2010-02-01

    Acetate is the most important intermediate in anaerobic degradation of organic matter. The carbon isotope effects associated with the oxidation of acetate (epsilon(ac)) were examined for four acetotrophic sulfur reducers, Desulfuromonas acetoxidans, Desulfuromonas thiophila, Desulfurella acetivorans, and Hippea maritima. During the consumption of acetate and sulfur, acetate was enriched in (13)C by 11.5 and 11.2 per thousand in Desulfuromonas acetoxidans and Desulfuromonas thiophila, respectively. By contrast, isotope fractionation in D. acetivorans and H. maritima resulted in isotope enrichment factors of epsilon(ac)=-6.3 per thousand and -8.4 per thousand, respectively. These sulfur-reducing bacteria all metabolize acetate via the tricarboxylic acid cycle, but have different mechanisms for the initial activation of acetate. In Desulfuromonas acetoxidans, acetyl-CoA is formed by succinyl-CoA : acetate-CoA-transferase, and in D. acetivorans by acetate kinase and phosphate acetyltransferase. Hence, values of epsilon(ac) seem to be characteristic for the type of activation of acetate to acetyl-CoA in acetotrophic sulfur reducers. Summarizing epsilon(ac)-values in anaerobic acetotrophic microorganisms, it appears that isotope fractionation depends on the mechanism of acetate activation to acetyl-CoA, on the key enzyme of the acetate dissimilation pathway, and on the bioavailability of acetate, which all have to be considered when using delta(13)C of acetate in environmental samples for diagnosis of the involved microbial populations. PMID:20002180

  7. Patch Clamp Studies on Root Cell Vacuoles of a Salt-Tolerant and a Salt-Sensitive Plantago Species 1

    PubMed Central

    Maathuis, Frans J. M.; Prins, Hidde B. A.

    1990-01-01

    Plantago media L. and Plantago maritima L. differ in their strategy toward salt stress, a major difference being the uptake and distribution of ions. Patch clamp techniques were applied to root cell vacuoles to study the tonoplast channel characteristics. In both species the major channel found was a 60 to 70 picosiemens channel with a low ion selectivity. The conductance of this channel for Na+ was the same as for K+, PK+/PNa+ = 1, whereas the cation/anion selectivity (PK+/Pc1?) was about 5. Gating characteristics were voltage and calcium dependent. An additional smaller channel of 25 picosiemens was present in P. maritima. In the whole vacuole configuration, the summation of the single channel currents resulted in slowly activated inward currents (t½ = 1.2 second). Inwardly directed, ATP-dependent currents could be measured against a ?pH gradient of 1.5 units over the tonoplast. This observation strongly indicated the physiological intactness of the used vacuoles. The open probability of the tonoplast channels dramatically decreased when plants were grown on NaCl, although single channel conductance and selectivity were not altered. PMID:16667252

  8. On the chimeric nature, thermophilic origin, and phylogenetic placement of the Thermotogales

    PubMed Central

    Zhaxybayeva, Olga; Swithers, Kristen S.; Lapierre, Pascal; Fournier, Gregory P.; Bickhart, Derek M.; DeBoy, Robert T.; Nelson, Karen E.; Nesbø, Camilla L.; Doolittle, W. Ford; Gogarten, J. Peter; Noll, Kenneth M.

    2009-01-01

    Since publication of the first Thermotogales genome, Thermotoga maritima strain MSB8, single- and multi-gene analyses have disagreed on the phylogenetic position of this order of Bacteria. Here we present the genome sequences of 4 additional members of the Thermotogales (Tt. petrophila, Tt. lettingae, Thermosipho melanesiensis, and Fervidobacterium nodosum) and a comprehensive comparative analysis including the original T. maritima genome. While ribosomal protein genes strongly place Thermotogales as a sister group to Aquificales, the majority of genes with sufficient phylogenetic signal show affinities to Archaea and Firmicutes, especially Clostridia. Indeed, on the basis of the majority of genes in their genomes (including genes that are also found in Aquificales), Thermotogales should be considered members of the Firmicutes. This result highlights the conflict between the taxonomic goal of assigning every species to a unique position in an inclusive Linnaean hierarchy and the evolutionary goal of understanding phylogenesis in the presence of pervasive horizontal gene transfer (HGT) within prokaryotes. Amino acid compositions of reconstructed ancestral sequences from 423 gene families suggest an origin of this gene pool even more thermophilic than extant members of this order, followed by adaptation to lower growth temperatures within the Thermotogales. PMID:19307556

  9. Vasodilator effects of Diocleinae lectins from the Canavalia genus.

    PubMed

    Assreuy, Ana Maria Sampaio; Fontenele, Sabrina Rodrigues; Pires, Alana de Freitas; Fernandes, Débora Costa; Rodrigues, Natália Velloso Fontenelle C; Bezerra, Eduardo Henrique Salviano; Moura, Tales Rocha; do Nascimento, Kyria Santiago; Cavada, Benildo Sousa

    2009-12-01

    This study investigated and compared vascular actions of leguminous lectins obtained from the Canavalia genus (Canavalia brasiliensis, Canavalia gladiata, and Canavalia maritima) in the rat models of paw edema and isolated aorta. Paw edema was induced by subcutaneous injection of lectins (0.01-1 mg/kg) in animals pre-treated or not with indomethacin or L-NAME. In isolated aorta, cumulative concentration curves of C. gladiata or C. brasiliensis (1-100 microg/ml) were performed at the contraction plateau induced by phenylephrine or at tissue basal tonus. The mechanism of the lectin relaxant action was investigated by previous addition of L-NAME, indomethacin, or tetraethylammonium. In both models, the lectin domain involvement was evaluated by incubation of lectins with their ligand and non-ligand sugars. The lectins induced paw edema paralleled by protein leakage. The edematogenic activity elicited by C. gladiata and C. brasiliensis involves prostaglandins and nitric oxide (NO), while that of C. maritima occurs without NO interference. C. gladiata and C. brasiliensis elicited aorta relaxation involving NO and prostacyclin, while that of C. gladiata included EDHF. All lectin effects were prevented by their binding sugars. The present study demonstrated important vasodilator effects of different degrees and mechanisms in vivo and in vitro of Canavalia lectins. In vivo, the edematogenic activity was paralleled by plasma exudation, and in vitro, aorta relaxation was strictly dependent on intact endothelium. All effects occurred via interaction with lectin domains and participation of NO and/or prostanoids. PMID:19855960

  10. Distribution and migration of seaside sparrows

    USGS Publications Warehouse

    Robbins, C.S.

    1983-01-01

    The majority of the nine presently recognized races of the Seaside Sparrow (Ammospiza maritima) are so similar to neighboring races that individual birds outside their known breeding range cannot be subspecifically identified with certainty. The northern race, A. m. maritima, is partially migratory, with most individuals departing in autumn from Chesapeake Bay and from all the coastal marshes that lie to the north of the mouth of this bay. No banded bird has been recaptured in winter south of its breeding locality, however, so even the major wintering ground of this subspecies cannot be defined. The other subspecies are presumed to be primarily sedentary. Median arrival and departure dates at Fairfield, Connecticut, are 18 May and 19 September. On Long Island, New York, the spring peak occurs in the third week of May, and the autumn peak in mid-October. Postbreeding wanderers of unknown origin move north and east in August and September to the coastal marshes of Maine, New Brunswick, and Nova Scotia. The remarkably few records away from tidewater are from North Carolina, eastern Pennsylvania, the lower Hudson River, and eastern Massachusetts.

  11. Plantain (Plantago L.) species as novel sources of flavonoid antioxidants.

    PubMed

    Beara, Ivana N; Lesjak, Marija M; Jovin, Emilija D; Balog, Kristina J; Anackov, Goran T; Orci?, Dejan Z; Mimica-Duki?, Neda M

    2009-10-14

    To examine the antioxidant properties of methanol extracts of selected Plantago species (P. argentea Chaix., P. holosteum Scop., P. major L., P. maritima L., and P. media L.), various assays that measure free radical scavenging ability were carried out: DPPH, hydroxyl radical, superoxide anion, and nitric oxide scavenger capacity tests, reducing power (FRAP) assay, and Fe(2+)/ascorbate induced lipid peroxidation. In all of the tests extracts showed a potent antioxidant effect compared with BHT, a well-known synthetic antioxidant, and the extract of P. major, accepted as an official remedy. Besides, in examined extracts the total phenolic amount (ranging from 38.43 to 70.97 mg of GAE/g of dw) and the total flavonoid content (5.31-13.10 mg of QE/g of dw) were determined. Furthermore, the presence and content of selected flavonoids (luteolin-7-O-glucoside, apigenin-7-O-glucoside, luteolin, apigenin, rutin, and quercetin) were studied using LC-MS/MS technique. LC-MS/MS analysis showed noticeable qualitative and quantitative differences between the species according to which the examined Plantago species could be regarded as a possible new source of natural antioxidants. In this study three of the species examined, P. maritima, P. argentea, and P. holosteum, have been analyzed for the first time. PMID:19754195

  12. The role of macrophytes as a refuge and food source for the estuarine isopod Exosphaeroma hylocoetes (Barnard, 1940)

    NASA Astrophysics Data System (ADS)

    Henninger, Tony O.; Froneman, P. William; Richoux, Nicole B.; Hodgson, Alan N.

    2009-04-01

    The role of submerged macrophytes as refugia from fish predation and as possible food sources for the estuarine isopod Exosphaeroma hylocoetes ( Barnard, K.H., 1940) was investigated. Laboratory experiments tested the effectiveness of artificial vegetation, replicating submerged vegetation, in enabling isopods to elude selected fish predators Rhabdosargus holubi, Glossogobius callidus, Monodactylus falciformis and Clinus cottoides. Isopods preferentially hid in the vegetation (>90%), even in absence of fish. The predatory fish had varying success in finding isopods within the vegetation. Isopod mortality ranged from 2% ( R. holubi) to a maximum of 87% ( C. cottoides) within vegetation, depending on the fish predator present. Stable isotope and fatty acid analyses ruled out the submerged macrophyte Ruppia maritima and inundated fringing grasses as direct food sources, but highlighted the epiphytic biota (mainly diatoms) found on the submerged vegetation and sediments as more likely food sources. These findings are consistent with gut content analyses. The results suggest that the close association of E. hylocoetes with R. maritima is the result of the vegetation providing the isopod with a refuge against fish predation as well as areas of increased food availability.

  13. Evaluation of a Florida coastal golf complex as a local and watershed source of bioavailable contaminants.

    PubMed

    Lewis, Michael A; Quarles, Robert L; Dantin, Darrin D; Moore, James C

    2004-02-01

    Contaminant fate in coastal areas impacted by golf course runoff is not well understood. This report summarizes trace metal, pesticide and PCB residues for colonized periphyton, Ruppia maritima (widgeon grass), Callinectes sapidus Rathbun (blue crabs) and Crassostrea virginica Gemlin (Eastern oyster) collected from areas adjacent to a Florida golf course complex which receive runoff containing reclaimed municipal wastewater. Concentrations of 19 chlorinated pesticides and 18 PCB congeners were usually below detection in the biota. In contrast, 8 trace metals were commonly detected although concentrations were not usually significantly different for biota collected from reference and non-reference coastal areas. Residue concentrations in decreasing order were typically: zinc, arsenic, copper, chromium, lead, nickel, cadmium and mercury. Mean BCF values for the eight trace metals ranged between 160-57000 (periphyton), 79-11033 (R. maritima), 87-162625 (C. virginica) and 12-9800 (C. sapidus). Most trace metal residues in periphyton colonized adjacent to the golf complex, were either similar to or significantly less than those reported for periphyton colonized in nearby coastal areas impacted by urban stormwater runoff and treated municipal and industrial wastewater discharges. Consequently, the recreational complex does not appear to be a major source of bioavailable contaminants locally nor in the immediate watershed based on results for the selected biota. PMID:14972577

  14. Seasonal Variation of the Macrozoobenthic Community Structure at Low Salinities in a Mediterranean Lagoon (Monolimni Lagoon, Northern Aegean)

    NASA Astrophysics Data System (ADS)

    Kevrekidis, Theodoros

    2004-09-01

    The macrozoobenthic community structure and dynamics at low salinities (0.3-6 psu) in a Mediterranean lagoon (Monolimni lagoon) were investigated. Samples were collected monthly from February 1998 to February 1999 at two sampling stations. Community structure was analyzed by means of uni- and multivariate methods. 21 taxa were collected; the amphipod Corophium orientale and the gastropod Ventrosia maritima dominated the assemblages. Total abundance peaked (50,000-60,000 individuals m-2) in mid or late autumn. Community structure showed an almost even seasonal periodicity; seasonal changes were mainly derived from the intense variation in abundance of most species and the non-occurrence of a few ones (e.g. Corophium insidiosum, Polydora ciliata) in spring and summer. Non- occurrence, which led to a depression of the most diversity indices, was possibly the only direct impact of the extremely low salinities (~0.3 psu) on community structure. The main structuring factors of the community in the deeper outer part of the lagoon were water temperature and depth, and in the innermost part, where a Ruppia maritima meadow occurred, were water temperature and predation pressure by crabs (Carcinus aestuarii) and gobies (Knipowitchia caucasica). A temporary decline in total abundance in summer followed an increase in abundance of these predators. (

  15. Age-specific, density-dependent and environment-based mortality of a short-lived perennial herb.

    PubMed

    Picó, F X; Retana, J

    2008-05-01

    Density-independent and density-dependent processes affect plant mortality. Although less well understood, age-specific mortality can also play an important role in plant mortality. The goal of this study was to analyse several factors accounting for mortality in the Mediterranean short-lived perennial herb Lobularia maritima. We followed three cohorts of plants (from emergence to death) during 4 years in field conditions. We collected data on plant mortality of the effect of biotic agents (moth larvae and mycoplasma-like organisms, MLOs) and environmental variables. We also estimated density-dependent relationships affecting the fate of seedlings and adults. Results show that cohorts differed in their survival curves and ageing significantly increased mortality risk. Seedling mortality was density-dependent whereas adult mortality was not affected by density. MLO infection led to higher plant mortality whereas moth larvae attack did not affect plant mortality. In general, seedlings and adult plants experienced the highest mortality events in summer. We found, however, weak relationships between weather records and plant mortality. Age and size structures were not correlated. Overall, this study provides a comprehensive review of age-specific, density-dependent and density-independent factors that account for mortality of L. maritima plants throughout their life cycle in field conditions, highlighting the fact that age is an important factor in determining plant population dynamics. PMID:18426484

  16. Genes for the Major Structural Components of Thermotogales Species’ Togas Revealed by Proteomic and Evolutionary Analyses of OmpA and OmpB Homologs

    PubMed Central

    Petrus, Amanda K.; Swithers, Kristen S.; Ranjit, Chaman; Wu, Si; Brewer, Heather M.; Gogarten, J. Peter; Pasa-Tolic, Ljiljana; Noll, Kenneth M.

    2012-01-01

    The unifying structural characteristic of members of the bacterial order Thermotogales is their toga, an unusual cell envelope that includes a loose-fitting sheath around each cell. Only two toga-associated structural proteins have been purified and characterized in Thermotoga maritima: the anchor protein OmpA1 (or Omp?) and the porin OmpB (or Omp?). The gene encoding OmpA1 (ompA1) was cloned and sequenced and later assigned to TM0477 in the genome sequence, but because no peptide sequence was available for OmpB, its gene (ompB) was not annotated. We identified six porin candidates in the genome sequence of T. maritima. Of these candidates, only one, encoded by TM0476, has all the characteristics reported for OmpB and characteristics expected of a porin including predominant ?-sheet structure, a carboxy terminus porin anchoring motif, and a porin-specific amino acid composition. We highly enriched a toga fraction of cells for OmpB by sucrose gradient centrifugation and hydroxyapatite chromatography and analyzed it by LC/MS/MS. We found that the only porin candidate that it contained was the TM0476 product. This cell fraction also had ?-sheet character as determined by circular dichroism, consistent with its enrichment for OmpB. We conclude that TM0476 encodes OmpB. A phylogenetic analysis of OmpB found orthologs encoded in syntenic locations in the genomes of all but two Thermotogales species. Those without orthologs have putative isofunctional genes in their place. Phylogenetic analyses of OmpA1 revealed that each species of the Thermotogales has one or two OmpA homologs. T. maritima has two OmpA homologs, encoded by ompA1 (TM0477) and ompA2 (TM1729), both of which were found in the toga protein-enriched cell extracts. These annotations of the genes encoding toga structural proteins will guide future examinations of the structure and function of this unusual lineage-defining cell sheath. PMID:22768259

  17. Genes for the Major Structural Components of Thermotogales Species’ Togas Revealed by Proteomic and Evolutionary Analyses of OmpA and OmpB Homologs

    SciTech Connect

    Petrus, Amanda K.; Swithers, Kristen S.; Ranjit, Chaman R.; Wu, Si; Brewer, Heather M.; Gogarten, J Peter; Pasa-Tolic, Ljiljana; Noll, Kenneth M.

    2012-06-29

    The unifying structural characteristic of members of the bacterial order Thermotogales is their toga, an unusual cell envelope that includes a loose-fitting sheath around each cell. Only two toga-associated structural proteins have been purified and characterized in Thermotoga maritima: the anchor protein OmpA1 (or Ompa) and the porin OmpB (or Ompb). The gene encoding OmpA1 (ompA1) was cloned and sequenced and later assigned to TM0477 in the genome sequence, but because no peptide sequence was available for OmpB, its gene (ompB) was not annotated. We identified six porin candidates in the genome sequence of T. maritima. Of these candidates, only one, encoded by TM0476, has all the characteristics reported for OmpB and characteristics expected of a porin including predominant b-sheet structure, a carboxy terminus porin anchoring motif, and a porin-specific amino acid composition. We highly enriched a toga fraction of cells for OmpB by sucrose gradient centrifugation and hydroxyapatite chromatography and analyzed it by LC/MS/MS. We found that the only porin candidate that it contained was the TM0476 product. This cell fraction also had b-sheet character as determined by circular dichroism, consistent with its enrichment for OmpB. We conclude that TM0476 encodes OmpB. A phylogenetic analysis of OmpB found orthologs encoded in syntenic locations in the genomes of all but two Thermotogales species. Those without orthologs have putative isofunctional genes in their place. Phylogenetic analyses of OmpA1 revealed that each species of the Thermotogales has one or two OmpA homologs. T. maritima has two OmpA homologs, encoded by ompA1 (TM0477) and ompA2 (TM1729), both of which were found in the toga protein-enriched cell extracts. These annotations of the genes encoding toga structural proteins will guide future examinations of the structure and function of this unusual lineage-defining cell sheath.

  18. Cover cropping alters the diet of arthropods in a banana plantation: a metabarcoding approach.

    PubMed

    Mollot, Gregory; Duyck, Pierre-François; Lefeuvre, Pierre; Lescourret, Françoise; Martin, Jean-François; Piry, Sylvain; Canard, Elsa; Tixier, Philippe

    2014-01-01

    Plant diversification using cover crops may promote natural regulation of agricultural pests by supporting alternative prey that enable the increase of arthropod predator densities. However, the changes in the specific composition of predator diet induced by cover cropping are poorly understood. Here, we hypothesized that the cover crop can significantly alter the diet of predators in agroecosystems. The cover crop Brachiaria decumbens is increasingly used in banana plantations to control weeds and improve physical soil properties. In this paper, we used a DNA metabarcoding approach for the molecular analysis of the gut contents of predators (based on mini-COI) to identify 1) the DNA sequences of their prey, 2) the predators of Cosmopolites sordidus (a major pest of banana crops), and 3) the difference in the specific composition of predator diets between a bare soil plot (BSP) and a cover cropped plot (CCP) in a banana plantation. The earwig Euborellia caraibea, the carpenter ant Camponotus sexguttatus, and the fire ant Solenopsis geminata were found to contain C. sordidus DNA at frequencies ranging from 1 to 7%. While the frequencies of predators positive for C. sordidus DNA did not significantly differ between BSP and CCP, the frequency at which E. caraibea was positive for Diptera was 26% in BSP and 80% in CCP; the frequency at which C. sexguttatus was positive for Jalysus spinosus was 14% in BSP and 0% in CCP; and the frequency at which S. geminata was positive for Polytus mellerborgi was 21% in BSP and 3% in CCP. E. caraibea, C. sexguttatus and S. geminata were identified as possible biological agents for the regulation of C. sordidus. The detection of the diet changes of these predators when a cover crop is planted indicates the possible negative effects on pest regulation if predators switch to forage on alternative prey. PMID:24695585

  19. Cover Cropping Alters the Diet of Arthropods in a Banana Plantation: A Metabarcoding Approach

    PubMed Central

    Mollot, Gregory; Duyck, Pierre-François; Lefeuvre, Pierre; Lescourret, Françoise; Martin, Jean-François; Piry, Sylvain; Canard, Elsa; Tixier, Philippe

    2014-01-01

    Plant diversification using cover crops may promote natural regulation of agricultural pests by supporting alternative prey that enable the increase of arthropod predator densities. However, the changes in the specific composition of predator diet induced by cover cropping are poorly understood. Here, we hypothesized that the cover crop can significantly alter the diet of predators in agroecosystems. The cover crop Brachiaria decumbens is increasingly used in banana plantations to control weeds and improve physical soil properties. In this paper, we used a DNA metabarcoding approach for the molecular analysis of the gut contents of predators (based on mini-COI) to identify 1) the DNA sequences of their prey, 2) the predators of Cosmopolites sordidus (a major pest of banana crops), and 3) the difference in the specific composition of predator diets between a bare soil plot (BSP) and a cover cropped plot (CCP) in a banana plantation. The earwig Euborellia caraibea, the carpenter ant Camponotus sexguttatus, and the fire ant Solenopsis geminata were found to contain C. sordidus DNA at frequencies ranging from 1 to 7%. While the frequencies of predators positive for C. sordidus DNA did not significantly differ between BSP and CCP, the frequency at which E. caraibea was positive for Diptera was 26% in BSP and 80% in CCP; the frequency at which C. sexguttatus was positive for Jalysus spinosus was 14% in BSP and 0% in CCP; and the frequency at which S. geminata was positive for Polytus mellerborgi was 21% in BSP and 3% in CCP. E. caraibea, C. sexguttatus and S. geminata were identified as possible biological agents for the regulation of C. sordidus. The detection of the diet changes of these predators when a cover crop is planted indicates the possible negative effects on pest regulation if predators switch to forage on alternative prey. PMID:24695585

  20. Enzyme activity and dynamics: xylanase activity in the absence of fast anharmonic dynamics.

    PubMed Central

    Dunn, R V; Réat, V; Finney, J; Ferrand, M; Smith, J C; Daniel, R M

    2000-01-01

    The activity and dynamics of a simple, single subunit enzyme, the xylanase from Thermotoga maritima strain Fj SS3B.1 have been measured under similar conditions, from -70 to +10 degrees C. The internal motions of the enzyme, as evidenced by neutron scattering, undergo a sharp transition within this temperature range; they show no evidence for picosecond-timescale anharmonic behaviour (e.g. local diffusive motions or jumps between alternative conformations) at temperatures below -50 degrees C, whereas these motions are strongly activated at higher temperatures. The activity follows Arrhenius behaviour over the whole of the temperature range investigated, -70 to +10 degrees C. The results indicate that a temperature range exists over which the enzyme rate-limiting step is independent of fast anharmonic dynamics. PMID:10677353

  1. Emissions of biogenic sulphur compounds from several wetland soils in Florida

    NASA Astrophysics Data System (ADS)

    Cooper, W. J.; Cooper, D. J.; Saltzman, E. S.; Mello, W. Z. de; Savoie, D. L.; Zika, R. G.; Prospero, J. M.

    Emission rates of the biogenic sulphur gases hydrogen sulphide, dimethyl sulphide, carbon disulphide and dimethyl disulphide have been measured from the exposed soils of five wetland plant communities in Florida. Dimethyl sulphide and hydrogen sulphide were the predominant species emitted. All the studied ecosystems showed diel variation in the emission rates of the biogenic sulphur gases with the highest emissions rates occurring early- to mid-afternoon, and the lowest emission rates occurring during the early morning. The relative magnitude of emissions from the individual ecosystems followed the trend Distichlis spicata > Avicennia germinans > Batis maritima ? Juncus roemerianus ? Cladium jamaicense. Only the emission rates from the peaty D. spicata site are comparable in magnitude to previous emission measurements in wetland ecosystems of Spartina alterniflora and associated mud flats.

  2. Cooperative action of alpha-glucanotransferase and maltogenic amylase for an improved process of isomaltooligosaccharide (IMO) production.

    PubMed

    Lee, Hyun-Soo; Auh, Joong-Hyuck; Yoon, Hyun-Geun; Kim, Myo-Jeong; Park, Jin-Hee; Hong, Seung-Suh; Kang, Min-Hyung; Kim, Tae-Jip; Moon, Tae-Wha; Kim, Jung-Wan; Park, Kwan-Hwa

    2002-05-01

    Maltogenic amylase and alpha-glucanotransferase (alpha-GTase) were employed in an effort to develop an efficient process for the production of isomaltooligosaccharides (IMOs). Bacillus stearothermophilus maltogenic amylase (BSMA) and alpha-GTase from Thermotoga maritima were overexpressed in Escherichia coli using overexpression vectors. An IMO mixture containing 58% of various IMOs was produced from liquefied corn syrup by the hydrolyzing and transglycosylation activities of BSMA alone. When BSMA and alpha-GTase were reacted simultaneously, the IMO content increased to 68% and contained relatively larger IMOs compared with the products obtained by the reaction without alpha-GTase. Time course analysis of the IMO production suggested that BSMA hydrolyzed maltopentaose and maltohexaose most favorably into maltose and maltotriose and transferred the resulting molecules simultaneously to acceptor molecules to form IMOs. alpha-GTase transferred donor sugar molecules to the hydrolysis products such as maltose and maltotriose to form maltopentaose, which was then rehydrolyzed by BSMA as a favorable substrate. PMID:11982404

  3. Wetland plants as indicators of heavy metal contamination.

    PubMed

    Phillips, D P; Human, L R D; Adams, J B

    2015-03-15

    In this study metal accumulating abilities of three emergent macrophytes (Phragmites australis, Typha capensis and Spartina maritima) were investigated in the urbanised Swartkops Estuary. Plants and sediment samples were collected at seven sites along the banks of the main channel and in adjacent canals. Sediments and plant organs were analysed, by means of atomic absorption spectrometry, for four elements (Cd, Cu, Pb, and Zn). Metal concentrations in the sediments of adjacent canals were found to be substantially higher than those at sites along the banks of the estuary. These differences were reflected in the plant organs for Pb and Zn, but not for Cu and Cd. All three species exhibited significantly higher concentrations of metals in their roots. These species are therefore suitable for use as indicators of the presence and level of heavy metal contaminants in estuaries. PMID:25599629

  4. POLYPEPTIDE AND POLYSACCHARIDE PROCESSING IN HYPERTHERMOPHILIC MICROORGANISMS

    SciTech Connect

    KELLY, ROBERT M.

    2008-12-22

    This project focused on the microbial physiology and biochemistry of heterotrophic hyperthermophiles with respect to mechanisms by which these organisms process polypeptides and polysaccharides under normal and stressed conditions. Emphasis is on two model organisms, for which completed genome sequences are available: Pyrococcus furiosus (growth Topt of 98°C), an archaeon, and Thermotoga maritima (growth Topt of 80°C), a bacterium. Both organisms are obligately anaerobic heterotrophs that reduce sulfur facultatively. Whole genome cDNA spotted microarrays were used to follow transcriptional response to a variety of environmental conditions in order to identify genes encoding proteins involved in the acquisition, synthesis, processing and utilization of polypeptides and polysaccharides. This project provided new insights into the physiological aspects of hyperthermophiles as these relate to microbial biochemistry and biological function in high temperature habitats. The capacity of these microorganisms to produce biohydrogen from renewable feedstocks makes them important for future efforts to develop biofuels.

  5. Taxonomic synopsis of invasive and native Spartina (Poaceae, Chloridoideae) in the Pacific Northwest (British Columbia, Washington and Oregon), including the first report of Spartina ×townsendii for British Columbia, Canada

    PubMed Central

    Saarela, Jeffery M.

    2012-01-01

    Abstract Five species of the grass genus Spartina are invading salt marshes along the Pacific coast of North America, of which three have been documented in British Columbia, Canada, in only the last decade. A taxonomic synopsis of the two native (Spartina gracilis, Spartina pectinata) and five introduced Spartina taxa (Spartina anglica, Spartina alterniflora, Spartina densiflora, Spartina patens, Spartina ×townsendii) in the Pacific Northwest is presented to facilitate their identification, including nomenclature, a new taxonomic key, new descriptions for a subset of taxa, and representative specimens. Spartina ×townsendii is newly reported for the flora of British Columbia. The non-coastal species Spartina pectinata is reported from an urban site in British Columbia, the first confirmed report of the taxon for the province. Lectotypes are newly designated for Spartina anglica C.E. Hubb., Spartina maritima subvar. fallax St.-Yves, and Spartina cynosuroides f. major St.-Yves. PMID:22461730

  6. In situ nitrogen generation removes wax from flowlines

    SciTech Connect

    Khalil, C.N. [Petrobras S.A., Rio de Janeiro (Brazil)

    1996-07-01

    Formation of paraffin (wax) in cold deepwater flowlines is a major problem for offshore operators of such facilities. Petrobras faces this problem continuously in its deepwater operations in the Campos basin, offshore Brazil. Since 1990, through its Petrobras Research Center (CENPES), the company has developed, extensively field tested, and recently commercialized, a novel technique for chemically removing such wax depositions. The process involves mixing and introducing to the line, two inorganic salts and organic solvents. The ensuing chemical reaction--which both generates nitrogen and heats the inside of the blocked flowline--allows the solvent to dissolve and dislodge the buildup, which is then flushed from the line. The process is called the Nitrogen Generation System (SGN). Petrobras/CENPES has recently formed a joint venture with the Brazilian service company Maritima Navegacao e Engenharia Ltda. to offer SGN services worldwide.

  7. What is the Origin of Internal Friction in Unfolded Proteins?

    NASA Astrophysics Data System (ADS)

    Papoian, Garegin; Echeverria, Ignacia

    2014-03-01

    The unfolded state is being increasingly recognized as critical to many biological processes. There are many proteins that are found only transiently in the unfolded state, eventually folding into globular structures. Other proteins, called intrinsically disordered proteins (IDPs), may be unfolded even when carrying out important biological functions. Despite its ubiquitousness, the unfolded ensemble is not fully understood. In this work, we have investigated the origin of friction for the unfolded proteins undergoing conformational diffusion. We used extensive all-atom molecular dynamics simulations to study the dynamics of the unfolded cold-shock protein (CSP) from Thermotoga maritima at different solvent viscosities and at different denaturant concentrations. We systematically analyzed the reconfiguration dynamics of relevant structural features such as dihedral angle rotations, hydrogen bonds and hydrophobic contacts forming and breaking. The results of our calculations are broadly consistent with the corresponding experimental measurements. Our findings have important implications for the folding kinetics of proteins, especially under physiological conditions.

  8. Chromosome counts of some Cuban Angiosperms

    Microsoft Academic Search

    Vlasta Jarolímová

    1994-01-01

    Chromosome numbers are reported for 14 species collected in Cuba. The first chromosome records are reported forAlbizzia cubana\\u000a Britton etWilson (2n=26),Atkinsia cubensis (Britton etWilson)Howard (2n=26),Caesalpinia violacea (Mill.)Standl. (2n=24),Colubrina ferruginosa\\u000a Brongn. (2n=24). Chromosome numbers of the following species were confirmed:Albizzia lebbeck (L.)Benth. (2n=26),Canavalia maritima (Aubl.)Thouars (2n=22),Casuarina equisetifolia\\u000a Forst. (2n=18),Cedrela mexicana\\u000a M.J. Roem. (2n=56),Delonix regia (Bojer)Raf. (2n=28),Guazuma tomentosa H.B.K. (2n=16),Lysiloma bahamense\\u000a Benth.

  9. Homologous Canavalia lectins elicit different patterns of antinociceptive responses.

    PubMed

    Pinto, Nilson Vieira; Santos, Cláudia Ferreira; Cavada, Benildo Sousa; do Nascimento, Kyria Santiago; Pereira Junior, Francisco Nascimento; Pires, Alana de Freitas; Assreuy, Ana Maria Sampaio

    2013-11-01

    Canavalia gladiata (CGL), C. maritima (ConM) and C. brasiliensis (ConBr) lectins were evaluated in nociception models. ConBr inhibited first (32%) and second (100%) phases of the formalin test; CGL inhibited only the first (74%) and ConM only the second (59%) phase. Hypernociception evaluated in the Von Frey test was inhibited by ConM (55%), CGL (41%) and ConBr (38%). Acetic acid-induced abdominal writhing was reduced by ConBr (66%), CGL (52%) and ConM (60%). ConBr and CGL effects were reversed by the lectin association with its ligand sugar. The antinociceptive activity of the structural homologous lectins was differentiated by potency, efficacy and mechanisms. PMID:24427956

  10. Histamine release induced by glucose (mannose)-specific lectins isolated from Brazilian beans. Comparison with concanavalin A.

    PubMed

    Gomes, J C; Ferreira, R R; Cavada, B S; Moreira, R A; Oliveira, J T

    1994-05-01

    The histamine releasing properties of glucose (mannose)-specific lectins isolated from Brazilian beans was examined. The Canavalia brasiliensis, Dioclea rostrata, and Dioclea virgata lectins induced histamine release in rat peritoneal mast cells similar to concanavalin A. Less potency and efficacy was observed for Canavalia maritima, Dioclea guianensis, and Dioclea violacea while very low activities were seen for the lectins from Dioclea grandiflora, Canavalia bonariensis, and Cratylia floribunda. The histamine releasing effect was quenched by higher doses of D. virgata lectin similar to what was reported for concanavalin A. This effect was abrogated by increasing the concentration of calcium in the incubating medium. As these above proteins have sites that bind calcium, higher doses of the lectins might withdraw the calcium which is essential for the mast cell secretion. PMID:7524287

  11. New crystal forms of Diocleinae lectins in the presence of different dimannosides

    PubMed Central

    Moreno, Frederico Bruno Mendes Batista; Bezerra, Gustavo Arruda; de Oliveira, Taianá Maia; de Souza, Emmanuel Prata; da Rocha, Bruno Anderson Matias; Benevides, Raquel Guimarães; Delatorre, Plínio; Cavada, Benildo Sousa; de Azevedo, Walter Filgueira

    2006-01-01

    Studying the interactions between lectins and sugars is important in order to explain the differences observed in the biological activities presented by the highly similar proteins of the Diocleinae subtribe. Here, the crystallization and preliminary X-­ray data of Canavalia gladiata lectin (CGL) and C. maritima lectin (CML) complexed with Man(?1-2)Man(?1)OMe, Man(?1-3)Man(?1)OMe and Man(?1-4)Man(?1)OMe in two crystal forms [the complexes with Man(?1-3)Man(?1)OMe and Man(?1-4)Man(?1)OMe crystallized in space group P32 and those with Man(?1-2)Man(?1)OMe crystallized in space group I222], which differed from those of the native proteins (P21212 for CML and C222 for CGL), are reported. The crystal complexes of ConA-like lectins with Man(?1-4)Man(?1)OMe are reported here for the first time. PMID:17077488

  12. Promiscuous Substrate Recognition in Folding and Assembly Activities of the Trigger Factor Chaperone

    SciTech Connect

    Martinez-Hackert, E.; Hendrickson, W

    2009-01-01

    Trigger factor (TF) is a molecular chaperone that binds to bacterial ribosomes where it contacts emerging nascent chains, but TF is also abundant free in the cytosol where its activity is less well characterized. In vitro studies show that TF promotes protein refolding. We find here that ribosome-free TF stably associates with and rescues from misfolding a large repertoire of full-length proteins. We identify over 170 members of this cytosolic Escherichia coli TF substrate proteome, including ribosomal protein S7. We analyzed the biochemical properties of a TF:S7 complex from Thermotoga maritima and determined its crystal structure. Thereby, we obtained an atomic-level picture of a promiscuous chaperone in complex with a physiological substrate protein. The structure of the complex reveals the molecular basis of substrate recognition by TF, indicates how TF could accelerate protein folding, and suggests a role for TF in the biogenesis of protein complexes.

  13. Promiscuous Substrate Recognition in Folding and Assembly Activities of the Trigger Factor Chaperone

    PubMed Central

    Martinez-Hackert, Erik; Hendrickson, Wayne A.

    2009-01-01

    SUMMARY Trigger factor (TF) is a molecular chaperone that famously binds to bacterial ribosomes where it contacts emerging nascent chains, but TF is also abundant free in the cytosol where its activity is less well characterized. In vitro studies show that TF promotes protein refolding. We find here that ribosome-free TF stably associates with and rescues from misfolding a large repertoire of full-length proteins. We identify over 170 members of this cytosolic Escherichia coli TF substrate proteome, including ribosomal protein S7. We analyzed the biochemical properties of a TF:S7 complex from Thermotoga maritima and determined its crystal structure. This is the first atomic-level structure of a promiscuous chaperone in complex with a physiological substrate protein. The structure of the complex reveals the molecular basis of substrate recognition by TF, indicates how TF could accelerate protein folding and suggests a role for TF in the biogenesis of protein complexes. PMID:19737520

  14. Efficient expression, purification and crystallisation of two hyperthermostable enzymes of histidine biosynthesis.

    PubMed

    Thoma, R; Obmolova, G; Lang, D A; Schwander, M; Jenö, P; Sterner, R; Wilmanns, M

    1999-07-01

    Enzymes from hyperthermophiles can be efficiently purified after expression in mesophilic hosts and are well-suited for crystallisation attempts. Two enzymes of histidine biosynthesis from Thermotoga maritima, N'-((5'-phosphoribosyl)-formimino)-5-aminoimidazol-4-carb oxamid ribonucleotide isomerase and the cyclase moiety of imidazoleglycerol phosphate synthase, were overexpressed in Escherichia coli, both in their native and seleno-methionine-labelled forms, purified by heat precipitation of host proteins and crystallised. N'-((5'-phosphoribosyl)-formimino)-5-aminoimidazol-4-carb oxamid ribonucleotide isomerase crystallised in four different forms, all suitable for X-ray structure solution, and the cyclase moiety of imidazoleglycerol phosphate synthase yielded one crystal form that diffracted to atomic resolution. The obtained crystals will enable the determination of the first three-dimensional structures of enzymes from the histidine biosynthetic pathway. PMID:10413084

  15. Proteolysis in hyperthermophilic microorganisms

    DOE PAGESBeta

    Ward, Donald E.; Shockley, Keith R.; Chang, Lara S.; Levy, Ryan D.; Michel, Joshua K.; Conners, Shannon B.; Kelly, Robert M.

    2002-01-01

    Proteases are found in every cell, where they recognize and break down unneeded or abnormal polypeptides or peptide-based nutrients within or outside the cell. Genome sequence data can be used to compare proteolytic enzyme inventories of different organisms as they relate to physiological needs for protein modification and hydrolysis. In this review, we exploit genome sequence data to compare hyperthermophilic microorganisms from the euryarchaeotal genusPyrococcus, the crenarchaeoteSulfolobus solfataricus, and the bacteriumThermotoga maritima. An overview of the proteases in these organisms is given based on those proteases that have been characterized and on putative proteases that have been identified from genomicmore »sequences, but have yet to be characterized. The analysis revealed both similarities and differences in the mechanisms utilized for proteolysis by each of these hyperthermophiles and indicated how these mechanisms relate to proteolysis in less thermophilic cells and organisms.« less

  16. Amplification, cloning, and sequencing of a nifH segment from aquatic microorganisms and natural communities.

    PubMed Central

    Kirshtein, J D; Paerl, H W; Zehr, J

    1991-01-01

    By use of the polymerase chain reaction and degenerate oligonucleotide primers for highly conserved regions of nifH, a segment of nifH DNA was amplified from several aquatic microorganisms, including an N2-fixing bacterium closely associated with the marine filamentous cyanobacterium Trichodesmium sp., a heterotrophic isolate from the root/rhizome of the seagrass Ruppia maritima, and the heterocystous freshwater cyanobacterium Anabaena oscillarioides. nifH segments were amplified directly from DNA extracted from the rhizosphere of roots of the seagrass Halodule wrightii. The nifH fragments were then cloned and sequenced. The DNA and deduced amino acid sequences were compared with known sequences, revealing distinct differences between taxonomic groups. This technique was shown to be useful for (i) the detection of N2-fixing microorganisms and (ii) rapidly obtaining the DNA sequence of the nifH gene, which provides information about general taxonomic groups of N2-fixing microorganisms. PMID:1768139

  17. Amplification, cloning, and sequencing of a nifH segment from aquatic microorganisms and natural communities.

    PubMed

    Kirshtein, J D; Paerl, H W; Zehr, J

    1991-09-01

    By use of the polymerase chain reaction and degenerate oligonucleotide primers for highly conserved regions of nifH, a segment of nifH DNA was amplified from several aquatic microorganisms, including an N2-fixing bacterium closely associated with the marine filamentous cyanobacterium Trichodesmium sp., a heterotrophic isolate from the root/rhizome of the seagrass Ruppia maritima, and the heterocystous freshwater cyanobacterium Anabaena oscillarioides. nifH segments were amplified directly from DNA extracted from the rhizosphere of roots of the seagrass Halodule wrightii. The nifH fragments were then cloned and sequenced. The DNA and deduced amino acid sequences were compared with known sequences, revealing distinct differences between taxonomic groups. This technique was shown to be useful for (i) the detection of N2-fixing microorganisms and (ii) rapidly obtaining the DNA sequence of the nifH gene, which provides information about general taxonomic groups of N2-fixing microorganisms. PMID:1768139

  18. Temporal and spatial variation in the macrophyte distribution in coastal lagoon Lake Nakaumi and its neighboring waters

    NASA Astrophysics Data System (ADS)

    Kunii, Hidenobu; Minamoto, Kouichi

    2000-10-01

    During the period May-December 1996, macrophyte distribution and its abundance were investigated for 24 sites in coastal lagoon Lake Nakaumi and its neighboring waters, southwestern Honshu, Japan. More than 21 taxa, including two aquatic angiosperms, were found and the taxa with high frequency of occurrence were Enteromorpha spp. and Sargassum thunbergii. Ruppia maritima, one of the endangered aquatic macrophytes in Japan, was also found making dense meadows in Honjou, an area planned to be reclaimed. Four distinct distributional regions were recognized in the lake by principal component analysis (PCA) using the seasonal maximum cover of each species, and a significant relation was found between PCA axis 1 and electric conductivity. A long-term change in floristic composition is also discussed based on the present results and literature.

  19. Biochemical characterization and structural analysis of a bifunctional cellulase/xylanase from Clostridium thermocellum.

    PubMed

    Yuan, Shuo-Fu; Wu, Tzu-Hui; Lee, Hsiao-Lin; Hsieh, Han-Yu; Lin, Wen-Ling; Yang, Barbara; Chang, Chih-Kang; Li, Qian; Gao, Jian; Huang, Chun-Hsiang; Ho, Meng-Chiao; Guo, Rey-Ting; Liang, Po-Huang

    2015-02-27

    We expressed an active form of CtCel5E (a bifunctional cellulase/xylanase from Clostridium thermocellum), performed biochemical characterization, and determined its apo- and ligand-bound crystal structures. From the structures, Asn-93, His-168, His-169, Asn-208, Trp-347, and Asn-349 were shown to provide hydrogen-bonding/hydrophobic interactions with both ligands. Compared with the structures of TmCel5A, a bifunctional cellulase/mannanase homolog from Thermotoga maritima, a flexible loop region in CtCel5E is the key for discriminating substrates. Moreover, site-directed mutagenesis data confirmed that His-168 is essential for xylanase activity, and His-169 is more important for xylanase activity, whereas Asn-93, Asn-208, Tyr-270, Trp-347, and Asn-349 are critical for both activities. In contrast, F267A improves enzyme activities. PMID:25575592

  20. Nutrient levels modify saltmarsh responses to increased inundation in different soil types.

    PubMed

    Wong, Joanne X W; Van Colen, Carl; Airoldi, Laura

    2015-03-01

    Saltmarshes have been depleted historically, and cumulative stressors threaten their future persistence. We examined experimentally how nutrient availability (high vs. low) affects the responses of Spartina maritima to increased inundation in two mineral soil types (low vs. medium organic). Increased inundation, one of the effects of accelerated sea level rise, had negative effects on most plant growth parameters, but the magnitude varied with soil and nutrient levels, and between plants from different locations. Average differences between inundation treatments were largest at high nutrient conditions in low organic matter soils. We conclude that saltmarsh vegetation would be more drastically affected by increased inundation in low than in medium organic matter soils, and especially in estuaries already under high nutrient availability. This knowledge enhances the prediction of changes at the foreshore of saltmarshes related to sea level rise, and the development of site-specific conservation strategies. PMID:25594372

  1. Acylated cyanidin 3-sambubioside-5-glucosides in three garden plants of the Cruciferae.

    PubMed

    Tatsuzawa, Fumi; Saito, Norio; Shinoda, Koichi; Shigihara, Atsushi; Honda, Toshio

    2006-06-01

    Seven acylated cyanidin 3-sambubioside-5-glucosides were isolated from the flowers of three garden plants in the Cruciferae. Specifically, four pigments were isolated from Lobularia maritima (L.) Desv., together with a known pigment, as well as, three pigments from Lunaria annua L., and two known pigments from Cheiranthus cheiri L. These pigments were determined to be cyanidin 3-O-[2-O-((acyl-II)-(beta-d-xylopyranosyl))-6-O-(acyl-I)-beta-d-glucopyranoside]-5-O-[6-O-(acyl-III)-beta-d-glucopyranoside], in which the acyl-I group is represented by glucosyl-p-coumaric acid, p-coumaric acid and ferulic acid, acyl-II by caffeic acid and ferulic acid, and acyl-III by malonic acid, respectively. The distribution and biosynthesis of acylated cyanidin 3-sambubioside-5-glucosides are discussed according to the variations of acylation and glucosylation at their 3-sambubiose residues. PMID:16777160

  2. Inhibition of acetylcholinesterase by extracts and constituents from Angelica archangelica and Geranium sylvaticum.

    PubMed

    Sigurdsson, Steinthor; Gudbjarnason, Sigmundur

    2007-01-01

    The aim of this study was to explore the acetylcholinesterase (AChE) inhibition of several Icelandic medicinal herbs. Ethanolic extracts of Angelica archangelica seeds and the aerial parts of Geranium sylvaticum proved effective, with IC50 values of 2.20 mg/ml and 3.56 mg/ml, respectively. The activity of imperatorin and xanthotoxin from A. archangelica was measured. Xanthotoxin proved much more potent than imperatorin, with an IC50 value of 155 microg/ml (0.72 mM) but that for imperatorin was above 274 microg/ml (1.01 mM). However, furanocoumarins seem to have a minor part in the total activity of this extract. Synergistic interaction was observed between the extracts of A. archangelica and G. sylvaticum. Several medicinal herbs (Achillea millefolium, Filipendula ulmaria, Thymus praecox and Matricaria maritima) did not show AChE inhibitory activity. PMID:18069242

  3. Biohydrogenesis in the Thermotogales

    SciTech Connect

    Kelly, Robert M [North Carolina State University

    2014-12-13

    The production and consumption of molecular hydrogen drives the physiology and bioenergetics of many microorganisms in hydrothermal environments. As such, the potential of these microorganisms as model systems to probe fundamental issues related to biohydrogen production merits consideration. It is important to understand how carbon/energy sources relate to the disposition of reducing power and, ultimately, the formation of molecular hydrogen by high temperature microorganisms. This project focused on bacteria in the thermophilic order Thermotogales, fermentative anaerobes that produce H2 from simple and complex carbohydrates. The major thrusts of the project are summarized in the Objectives listed below: OBJECTIVE 1: Examine the regulation of substrate catabolic proteins and pathways as this relates to carbon partitioning, disposition of reducing power, and H2 generation in Thermotoga maritima. OBJECTIVE 2: Apply classical genetics and develop molecular genetic tools for Thermotoga species to dissect catabolic and regulatory pathways related to sugar metabolism and H2 evolution. OBJECTIVE 3: Thermotogales biodiversity arises from adaptive specialization that expands on a conserved minimal genome; physiological characterization of selected novel traits will be done to expand understanding of biohydrogenesis. Four species within the genus Thermotoga were examined to understand similarities and differences in the mechanisms by which simple and complex carbohydrates were utilized and converted to molecular hydrogen. Although the core genome of these four species represented 75% of open reading frames (ORFs), there were significant differences in carbohydrate utilization patterns. New ABC transporters were identified within the Thermotogales through genomic and biochemical analysis. Molecular genetics tools were developed to examine Thermotoga maritima physiology. Cell lines were created in which both H2 and acetate levels were elevated on a per cell basis relative to the wild type, while lactate remained undetectable. Genome resequencing indicated that the primary genetic target for these phenotypic changes was the ATP binding component of a maltose ABC transporter. High temperature anaerobic [14C]-maltose transport assays demonstrated maltose uptake was reduced in the H2 overproducing cell lines. This suggested normal rates of maltose transport in the wild type organism lead to a metabolic imbalance that limited H2 synthesis. The microbial ecology of T. maritima was examined through functional genomics experiments. Under low nutrient conditions, T. maritima was observed to produce a range of putative peptides, some of which were related to ?-carbon cyclic peptides produced by Bacillus subtilus. Finally, the role of ‘toga’ in these novel microorganisms was shown to involve association with insoluble growth substrates. The ‘toga’ distends from the cytoplasmic membrane-enclosed portion of the cells as they enter the late exponential/stationary phase of growth. Some of the genes encoding toga-associated proteins were up-regulated during this phase of growth and the distension is caused by continued growth of the toga, and not shrinkage of the cytoplasmic aspect of the cells. This increase in cell surface area may have selective value to provide a larger anchor for polysaccharide hydrolytic enzymes during a time of nutritional stress. This project led to many interesting insights about the Thermotogales that have both scientific and technological implications. Ongoing work will leverage these developments to further elucidate many interesting features of these novel microorganisms.

  4. Crystal Structure of the Lysine Riboswitch Regulatory mRNA Element

    SciTech Connect

    Garst, A.; Heroux, A; Rambo, R; Batey, R

    2008-01-01

    Riboswitches are metabolite-sensitive elements found in mRNAs that control gene expression through a regulatory secondary structural switch. Along with regulation of lysine biosynthetic genes, mutations within the lysine-responsive riboswitch (L-box) play a role in the acquisition of resistance to antimicrobial lysine analogs. To understand the structural basis for lysine binding, we have determined the 2.8{angstrom} resolution crystal structure of lysine bound to the Thermotoga maritima asd lysine riboswitch ligand-binding domain. The structure reveals a complex architecture scaffolding a binding pocket completely enveloping lysine. Mutations conferring antimicrobial resistance cluster around this site as well as highly conserved long range interactions, indicating that they disrupt lysine binding or proper folding of the RNA. Comparison of the free and bound forms by x-ray crystallography, small angle x-ray scattering, and chemical probing reveals almost identical structures, indicating that lysine induces only limited and local conformational changes upon binding.

  5. Ligand-induced conformational changes in a thermophilic ribose-binding protein

    SciTech Connect

    Cuneo, Matthew J.; Beese, Lorena S.; Hellinga, Homme W. (Duke)

    2009-05-21

    Members of the periplasmic binding protein (PBP) superfamily are involved in transport and signaling processes in both prokaryotes and eukaryotes. Biological responses are typically mediated by ligand-induced conformational changes in which the binding event is coupled to a hinge-bending motion that brings together two domains in a closed form. In all PBP-mediated biological processes, downstream partners recognize the closed form of the protein. This motion has also been exploited in protein engineering experiments to construct biosensors that transduce ligand binding to a variety of physical signals. Understanding the mechanistic details of PBP conformational changes, both global (hinge bending, twisting, shear movements) and local (rotamer changes, backbone motion), therefore is not only important for understanding their biological function but also for protein engineering experiments. Here we present biochemical characterization and crystal structure determination of the periplasmic ribose-binding protein (RBP) from the hyperthermophile Thermotoga maritima in its ribose-bound and unliganded state. The T. maritima RBP (tmRBP) has 39% sequence identity and is considerably more resistant to thermal denaturation (appTm value is 108 C) than the mesophilic Escherichia coli homolog (ecRBP) (appTm value is 56 C). Polar ligand interactions and ligand-induced global conformational changes are conserved among ecRBP and tmRBP; however local structural rearrangements involving side-chain motions in the ligand-binding site are not conserved. Although the large-scale ligand-induced changes are mediated through similar regions, and are produced by similar backbone movements in tmRBP and ecRBP, the small-scale ligand-induced structural rearrangements differentiate the mesophile and thermophile. This suggests there are mechanistic differences in the manner by which these two proteins bind their ligands and are an example of how two structurally similar proteins utilize different mechanisms to form a ligand-bound state.

  6. Distribution of folates and modified folates in extremely thermophilic bacteria.

    PubMed Central

    White, R H

    1991-01-01

    Analyses were made of the structures and levels of folates and modified folates present in extremely thermophilic bacteria. These procedures involved the chemical analysis of products resulting from the oxidative cleavage of the 6-substituted, folatelike tetrahydropterins present in the cells. Air-oxidized cell extracts of extreme thermophiles from two members of the archaebacterial order Thermococcales, Thermococcus celer and Pyrococcus furiosus, contained only 7-methylpterin, indicating that these cells contain a modified folate with a methylated pterin. Cell extracts also contained 6-acetyl-7-methyl-7,8-dihydropterin, another product derived from the oxidative cleavage of a dimethylated folate, demonstrating that both the C-7 and C-9 carbons of the pterin were methylated. Extracts, however, contained neither p-aminobenzoylpolyglutamates nor methaniline, the oxidative cleavage products of folates and methanopterin, respectively, indicating that they contain a previously undescribed C1 carrier(s). On the basis of the level of the 7-methylpterin isolated, the levels of modified folate were 2 to 10 times higher than those typically found in mesophilic bacteria and 10 to 100 times less than the level of methanopterin found in the methanogenic bacteria. Oxidized cell extracts of Sulfolobus spp. of the archaebacterial order Sulfolobales contained only pterin, and, like members of the order Thermococcales, they contained neither-p-aminobenzoylpolyglutamates nor methaniline. Oxidized cell extracts of the extreme thermophiles Pyrobaculum sp. strain H10 and Pyrodictium occultum, from the archaebacterial orders Thermoproteales and Pyrodictiales, respectively, and Thermotoga maritima from the eubacterial order Thermotogales, contained pterin and p-aminobenzoylpolyglutamates, indicating that these cells contained unmodified folates. The levels of p-aminobenzoylpolyglutamates in these archaebacterial cell extracts indicate that the folates were present in the cells at levels 4 to 10 times higher than generally found in those mesophilic eubacteria which do not folates in energy metabolism. The levels and chain lengths of the of p-aminobenzoylpolyglutamates present in Thermotoga maritima were typical of those found in mesophilic eubacteria. PMID:1900506

  7. Relationships between the floral neighborhood and individual pollen limitation in two self-incompatible herbs.

    PubMed

    Jakobsson, Anna; Lázaro, Amparo; Totland, Orjan

    2009-07-01

    Local flower density can affect pollen limitation and plant reproductive success through changes in pollinator visitation and availability of compatible pollen. Many studies have investigated the relationship between conspecific density and pollen limitation among populations, but less is known about within-population relationships and the effect of heterospecific flower density. In addition, few studies have explicitly assessed how the spatial scales at which flowers are monitored affect relationships. We investigated the effect of floral neighborhood on pollen limitation at four spatial scales in the self-incompatible herbs Armeria maritima spp. maritima and Ranunculus acris spp. acris. Moreover, we measured pollen deposition in Armeria and pollinator visits to Ranunculus. There was substantial variation in pollen limitation among Armeria individuals, and 25% of this variation was explained by the density of compatible and heterospecific flowers within a 3 m circle. Deposition of compatible pollen was affected by the density of compatible and incompatible inflorescences within a 0.5 m circle, and deposition of heterospecific pollen was affected by the density of heterospecific flowers within a 2 m circle. In Ranunculus, the number of pollinator visits was affected by both conspecific and heterospecific flower densities. This did not, however, result in effects of the floral neighborhood on pollen limitation, probably due to an absence of pollen limitation at the population level. Our study shows that considerable variation in pollen limitation may occur among individuals of a population, and that this variation is partly explained by floral neighborhood density. Such individual-based measures provide an important link between pollen limitation theory, which predicts ecological and evolutionary causes and consequences for individual plants, and studies of the effects of landscape fragmentation on plant species persistence. Our study also highlights the importance of considering multiple spatial scales to understand the spatial extent of pollination processes within a population. PMID:19415338

  8. 210Po bioaccumulation in coastal sand dune wild legumes--Canavalia spp. of southwest coast of India.

    PubMed

    Bhat, Rajeev; Sridhar, K R; Rajashekara, K M; Narayana, Y

    2005-09-01

    In view of considerable natural background radioactivity reported from southwest coast of India, the current study documents bioaccumulation of 210Po in two dominant coastal sand dune perennial mat-forming wild legumes, Canavalia cathartica and C. maritima. Root, stem, leaf, mature beans, dry seeds and rhizosphere sand were analyzed for 210Po concentration. 210Po activity decreased in the order of leaves > roots > seeds > stems > beans. The highest 210Po activity was recorded in rhizosphere sand samples (5.78-5.88 Bq kg(-1)) followed by the leaf samples (3.27-3.07 Bq kg(-1)), while it was lowest in mature beans (0.13-0.20 Bq kg(-1)). 210Po activities or tissue moisture between plant species were not significantly different (p > 0.05; t-test). But 210Po activity vs. moisture differed significantly in all tissues (p = 0.0001), vegetative tissues (root, stem and leaf) (p = 0.0016), seeds (p = 0.0393) and proteins in seeds (p = 2.355 x 10(-6)) indicating the importance of moisture and protein in 210Po accumulation. Although 210Po has affinity for proteins, it did not concentrate too much in seed proteins of Canavalia. Concentration of 210Po in mature beans is at safe levels as fisher folk only consume tender pods occasionally. 210Po activity in Canavalia is compared with other plant materials. As the landraces of C. cathartica and C. maritima are distributed throughout pantropical coastal areas, the current study emphasizes on considering them as bioindicators to monitor 210Po in coastal sand dune biomes and in turn the health of coastal population. PMID:16121264

  9. Stability of endoglucanases from mesophilic fungus and thermophilic bacterium in acidified polyols.

    PubMed

    Chong, Barrie Fong; Harrison, Mark D; O'Hara, Ian M

    2014-01-01

    Recent developments in chemical pretreatments of lignocellulosic biomass using polyols as co-solvents (e.g., glycerol and ethylene glycol) at temperatures less than 100°C may allow the effective use of thermostable and non-thermostable cellulases in situ during the saccharification process. The potential of biomass saccharifying enzymes, endoglucanases (EG) from a thermophilic bacterium (Thermotoga maritima) and a mesophilic fungus (Trichoderma longibrachiatum), to retain their activity in aqueous buffer, acidified glycerol, and acidified ethylene glycol used as co-solvents at pretreatment temperatures at or below 100°C were examined. The results show that despite its origin, T. longibrachiatum EG (Tl-EG) retained 75% of its activity after exposure to 100°C for 5 min in aqueous buffer while T. maritima EG (Tm-EG) retained only 5% activity. However, at 90°C both enzymes retained over 87% of their activity. In acidified (0.1% (w/w) H2SO4) glycerol, Tl-EG retained similar activity (80%) to that obtained in glycerol alone, while Tm-EG retained only 35%. With acidified ethylene glycol under these conditions, both Tl-EG and Tm-EG retained 36% of their activity. The results therefore show that Tl-EG is more stable in both acidified glycerol and ethylene glycol than Tm-EG. A preliminary kinetic study showed that pure glycerol improved the thermal stability of Tl-EG but destabilized Tm-EG, relative to the buffer solution. The half-lives of both Tl-EG and Tm-EG are 4.5 min in acidified glycerol, indicating that the effectiveness of these enzymes under typical pretreatment times of greater than 15 min will be considerably diminished. Attempts have been made to explain the differences in the results obtained between the two enzymes. PMID:24910337

  10. Mother and offspring fitness in an insect with maternal care: phenotypic trade-offs between egg number, egg mass and egg care

    PubMed Central

    2014-01-01

    Background Oviparous females have three main options to increase their reproductive success: investing into egg number, egg mass and/or egg care. Although allocating resources to either of these three components is known to shape offspring number and size, potential trade-offs among them may have key impacts on maternal and offspring fitness. Here, we tested the occurrence of phenotypic trade-offs between egg number, egg mass and maternal expenditure on egg care in the European earwig, Forficula auricularia, an insect with pre- and post-hatching forms of maternal care. In particular, we used a series of laboratory observations and experiments to investigate whether these three components non-additively influenced offspring weight and number at hatching, and whether they were associated with potential costs to females in terms of future reproduction. Results We found negative associations between egg number and mass as well as between egg number and maternal expenditure on egg care. However, these trade-offs could only be detected after statistically correcting for female weight at egg laying. Hatchling number was not determined by single or additive effects among the three life-history traits, but instead by pairwise interactions among them. In particular, offspring number was positively associated with the number of eggs only in clutches receiving high maternal care or consisting of heavy eggs, and negatively associated with mean egg mass in clutches receiving low care. In contrast, offspring weight was positively associated with egg mass only. Finally, maternal expenditure on egg care reduced their future reproduction, but this effect was only detected when mothers were experimentally isolated from their offspring at egg hatching. Conclusions Overall, our study reveals simultaneous trade-offs between the number, mass and care of eggs. It also demonstrates that these factors interact in their impact on offspring production, and that maternal expenditure on egg care possibly shapes female future reproduction. These findings emphasize that studying reproductive success requires consideration of phenotypic trade-offs between egg-number, egg mass and egg care in oviparous species. PMID:24913927

  11. Nectar-carbohydrate production and composition vary in relation to nectary anatomy and location within individual flowers of several species of Brassicaceae.

    PubMed

    Davis, A R; Pylatuik, J D; Paradis, J C; Low, N H

    1998-06-01

    Nectar-carbohydrate production and composition were investigated by high-performance liquid chromatography and enzymology in nine species from five tribes of the Brassicaceae. In six species (Arabidopsis thaliana (L.) Heynh., Brassica napus L., B. rapa L., Lobularia maritima (L.) Desv., Raphanus sativus L., Sinapis arvensis L.) that produced nectar from both lateral nectaries (associated with the short stamens) and median nectaries (outside the long stamens), on average 95% of the total nectar carbohydrate was collected from the lateral ones. Nectar from these glands possessed a higher glucose/fructose ratio (usually 1.0-1.2) than that from the median nectaries (0.2-0.9) within the same flower. Comparatively little sucrose was detected in any nectar samples except from Matthiola bicornus (Sibth. et Sm.) DC., which possessed lateral nectaries only and produced a sucrose-dominant exudate. The anatomy of the nectarial tissue in nectar-secreting flowers of six species, Hesperis matronalis L., L. maritima, M. bicornus, R. sativus, S. arvensis, and Sisymbrium loeselii L., was studied by light and scanning-electron microscopy. Phloem alone supplied the nectaries. However, in accordance with their overall nectar-carbohydrate production, the lateral glands received relatively rich quantities of phloem that penetrated far into the glandular tissue, whereas median glands were supplied with phloem that often barely innervated them. All nectarial tissue possessed modified stomata (with the exception of the median glands of S. loeselii, which did not produce nectar); further evidence was gathered to indicate that these structures do not regulate nectar flow by guard-cell movements. The numbers of modified stomata per gland showed no relation to nectar-carbohydrate production. Taken together, the data on nectar biochemistry and nectary anatomy indicate the existence of two distinct nectary types in those Brassicacean species that possess both lateral and median nectaries, regardless of whether nectarial tissue is united around the entire receptacle or not. It is proposed that the term "nectarium" be used to represent collectively the multiple nectaries that can be found in individual flowers. PMID:9637073

  12. USE OF GREEN MANURE CROPS AND SUGAR BEET VARIETIES TO CONTROL HETERODERA BETAE.

    PubMed

    Raaijmakers, E

    2014-01-01

    Although it is less studied than the white beet cyst nematode (Heterodera schachtii), the yellow beet cyst nematode (H. betae) has been found in many countries in Europe. For example in The Netherlands, France and Spain. H. betae causes yield losses on sandy soils. A high infestation can result in loss of complete plants. In The Netherlands, this nematode is especially found in the south eastern and north eastern part, where it occurs on 18% and 5% of the fields, respectively. From a project of the Dutch Sugar beet Research Institute IRS (SUSY) on factors explaining differences in sugar yield, this nematode was one of the most important factors reducing sugar yields on sandy soils. Until 2008, the only way to control H. betae was by reducing the number of host crops in the crop rotation. Host crops are crops belonging to the families of Cruciferae, Chenopodiaceae, Polygonaceae, Caryophyllaceae and Leguminosea. In order to find more control measures, research was done to investigate the host status of different green manure crops and the resistance and tolerance of different sugar beet varieties to H. betae. White mustard (Sinapis alba) and oil seed radish (Raphanus sativus spp. oleiferus) varieties resistant to H. schachtii were investigated for their resistance against H. betae. A climate room trial and a field trial with white mustard and oil seed radish were conducted in 2007 and 2008, respectively. Results show that H. betae could multiply on susceptible white mustard and susceptible oil seed radish, but not on the H. schachtii resistant varieties. In climate room trials in 2009, 2010 and 2011 and field trials in 2010, 2011 and 2012, the effect of different sugar beet varieties on the multiplication of H. betae and the effect of H. betae on yield at different infestation levels was investigated. Sugar beet varieties with resistance genes to H. schachtii (from Beta procumbens or B. maritima) were selected. Varieties with resistance genes from these sources were not totally resistant to H. betae, but limited the multiplication of this nematode in comparison with susceptible varieties considerably. Only the varieties with resistance genes from B. maritima gave higher yields in comparison with susceptible varieties. Growing these varieties was already profitable from very light infestation levels (75 eggs and larvae/100 ml soil) of H. betae. Therefore, resistant cruciferous green manure crops and resistant and tolerant sugar beet varieties are good tools for growers to control H. betae. PMID:26084110

  13. Mercury-resistant bacteria from salt marsh of Tagus Estuary: the influence of plants presence and mercury contamination levels.

    PubMed

    Figueiredo, Neusa L L; Areias, Andreia; Mendes, Ricardo; Canário, João; Duarte, Aida; Carvalho, Cristina

    2014-01-01

    Mercury (Hg) contamination of aquatic systems has been recognized as a global, serious problem affecting both wildlife and humans. High levels of Hg, in particular methylmercury (MeHg), were detected in surface sediments of Tagus Estuary. MeHg is neurotoxic and its concentration in aquatic systems is dependent upon the relative efficiency of reduction, methylation, and demethylation processes, which are mediated predominantly by the microbial community, in particular mercury-resistant (HgR) bacteria. Plants in contaminated ecosystems are known to take up Hg via plant roots. Therefore, the aims of this study were to (1) isolate and characterize HgR bacteria from a salt marsh of Tagus Estuary (Rosário) and (2) determine HgR bacteria levels in the rhizosphere and, consequently, their influence in metal cycling. To accomplish this objective, sediments samples were collected during the spring season in an area colonized by Sacocornia fruticosa and Spartina maritima and compared with sediments without plants. From these samples, 13 aerobic HgR bacteria were isolated and characterized morphologically, biochemically, and genetically, and susceptibility to Hg compounds, Hg(2+), and MeHg was assessed by determination of minimal inhibitory concentration (MIC). Genetically, the mer operon was searched by polymerase chain reaction (PCR) and 16S rRNA sequencing was used for bacterial identification. Results showed that the isolates were capable of growing in the presence of high Hg concentration with MIC values for HgCl2 and MeHgCl in the ranges of 1.7-4.2 ?g/ml and 0.1-0.9 ?g/ml, respectively. The isolates from sediments colonized with Sacocornia fruticosa displayed higher resistance levels compared to ones colonized with Spartina maritima. Bacteria isolates showed different capacity of Hg accumulation but all displayed Hg volatilization capabilities (20-50%). Mer operon was found in two isolates, which genetically confirmed their capability to convert Hg compounds by reducing them to Hg(0). Thus, these results are the first evidence of the relevance of interaction between bacteria and plants in Hg cycling in Tagus Estuary. PMID:25072727

  14. Spatial and temporal habitat partitioning by zooplankton in the Bornholm Basin (central Baltic Sea)

    NASA Astrophysics Data System (ADS)

    Schulz, Jan; Peck, Myron A.; Barz, Kristina; Schmidt, Jörn Oliver; Hansen, Frank C.; Peters, Janna; Renz, Jasmin; Dickmann, Miriam; Mohrholz, Volker; Dutz, Jörg; Hirche, Hans-Jürgen

    2012-12-01

    The deep basins in the Baltic Sea such as the Bornholm Basin (BB) are subject to seasonal changes in the strength of physico-chemical stratification. These depth-related changes in key abiotic factors are strong drivers of habitat partitioning by the autochthonous zooplankton community. Species-specific ecophysiological preferences often result in both seasonal and inter-annual changes in vertical abundance that, when combined with depth-specific water currents, also lead to horizontal differences in spatial distribution. The present study documented the seasonal and depth-specific changes in the abundance and species composition of zooplankton in the BB based upon broad-scale survey data: 832 vertically-resolved (10 m) multinet samples collected at nine stations between March 2002 and May 2003. Changes in the zooplankton community were significantly correlated with changes in ambient hydrography. Each of five taxa (Bosmina coregoni maritima, Acartia spp., Pseudocalanus spp., Temora longicornis, Synchaeta spp.) contributed >10% to the zooplankton community composition. The appearance of cladocerans was mainly correlated with the phenology of thermocline development in the spring. The cladoceran B. coregoni maritima was a dominant member of this community during the warmest periods, preferring the surface waters above the thermocline. Copepods exhibited distinct, ontogenetic and seasonal changes in their distribution. The rotifers (Synchaeta sp.) were the most abundant zooplankton in May. Based on a multivariate approach and the evaluation of vertical distribution patterns, five major habitat utilisation modes were identified that were based, to a large extent, on the dynamics of thermal and haline stratification of the Baltic Sea. Our statistical analysis of one of the most thorough datasets collected on Baltic zooplankton in recent decades reveals some of the factors that make this stratified system highly dynamic with respect to the spatial overlap between predators and prey. As fish and gelatinous plankton often feed in distinct layers and/or exhibit feeding migrations, the inhomogeneous distribution of potential prey can result in a spatial mismatch. Based on the five modes identified at the community level for zooplankton, we discuss how climate-driven hydrographic variability may influence the strength of trophic coupling within the Bornholm Basin.

  15. Microfluidic glycosyl hydrolase screening for biomass-to-biofuel conversion.

    PubMed

    Bharadwaj, Rajiv; Chen, Zhiwei; Datta, Supratim; Holmes, Bradley M; Sapra, Rajat; Simmons, Blake A; Adams, Paul D; Singh, Anup K

    2010-11-15

    The hydrolysis of biomass to fermentable sugars using glycosyl hydrolases such as cellulases and hemicellulases is a limiting and costly step in the conversion of biomass to biofuels. Enhancement in hydrolysis efficiency is necessary and requires improvement in both enzymes and processing strategies. Advances in both areas in turn strongly depend on the progress in developing high-throughput assays to rapidly and quantitatively screen a large number of enzymes and processing conditions. For example, the characterization of various cellodextrins and xylooligomers produced during the time course of saccharification is important in the design of suitable reactors, enzyme cocktail compositions, and biomass pretreatment schemes. We have developed a microfluidic-chip-based assay for rapid and precise characterization of glycans and xylans resulting from biomass hydrolysis. The technique enables multiplexed separation of soluble cellodextrins and xylose oligomers in around 1 min (10-fold faster than HPLC). The microfluidic device was used to elucidate the mode of action of Tm_Cel5A, a novel cellulase from hyperthermophile Thermotoga maritima . The results demonstrate that the cellulase is active at 80 °C and effectively hydrolyzes cellodextrins and ionic-liquid-pretreated switchgrass and Avicel to glucose, cellobiose, and cellotriose. The proposed microscale approach is ideal for quantitative large-scale screening of enzyme libraries for biomass hydrolysis, for development of energy feedstocks, and for polysaccharide sequencing. PMID:20964411

  16. Structure and electrostatic property of cytoplasmic domain of ZntB transporter.

    SciTech Connect

    Tan, K.; Sather, A.; Robertson, J. L.; Moy, S.; Roux, B.; Joachimiak, A.; Biosciences Division; Cornell Univ.; Univ. of Chicago

    2009-10-01

    ZntB is the distant homolog of CorA Mg{sup 2+} transporter within the metal ion transporter superfamily. It was early reported that the ZntB from Salmonella typhimurium facilitated efflux of Zn{sup 2+} and Cd{sup 2+}, but not Mg{sup 2+}. Here, we report the 1.90 {angstrom} crystal structure of the intracellular domain of ZntB from Vibrio parahemolyticus. The domain forms a funnel-shaped homopentamer that is similar to the full-length CorA from Thermatoga maritima, but differs from two previously reported dimeric structures of truncated CorA intracellular domains. However, no Zn{sup 2+} or Cd{sup 2+} binding sites were identified in the high-resolution structure. Instead, 25 well-defined Cl{sup -} ions were observed and some of these binding sites are highly conserved within the ZntB family. Continuum electrostatics calculations suggest that the central pore of the funnel is highly attractive for cations, especially divalents. The presence of the bound Cl{sup -} ions increases the stability of cations along the pore suggesting they could be important in enhancing cation transport.

  17. Rational design of a fusion partner for membrane protein expression in E. coli

    PubMed Central

    Luo, Jianying; Choulet, Julie; Samuelson, James C

    2009-01-01

    We have designed a novel protein fusion partner (P8CBD) to utilize the co-translational SRP pathway in order to target heterologous proteins to the E. coli inner membrane. SRP-dependence was demonstrated by analyzing the membrane translocation of P8CBD-PhoA fusion proteins in wt and SRP-ffh77 mutant cells. We also demonstrate that the P8CBD N-terminal fusion partner promotes over-expression of a Thermotoga maritima polytopic membrane protein by replacement of the native signal anchor sequence. Furthermore, the yeast mitochondrial inner membrane protein Oxa1p was expressed as a P8CBD fusion and shown to function within the E. coli inner membrane. In this example, the mitochondrial targeting peptide was replaced by P8CBD. Several practical features were incorporated into the P8CBD expression system to aid in protein detection, purification, and optional in vitro processing by enterokinase. The basis of membrane protein over-expression toxicity is discussed and solutions to this problem are presented. We anticipate that this optimized expression system will aid in the isolation and study of various recombinant forms of membrane-associated protein. PMID:19530231

  18. Evidence for extensive gene flow and Thermotoga subpopulations in subsurface and marine environments.

    PubMed

    Nesbø, Camilla L; S Swithers, Kristen; Dahle, Håkon; Haverkamp, Thomas Ha; Birkeland, Nils-Kåre; Sokolova, Tatiana; Kublanov, Ilya; Zhaxybayeva, Olga

    2015-07-01

    Oil reservoirs represent a nutrient-rich ecological niche of the deep biosphere. Although most oil reservoirs are occupied by microbial populations, when and how the microbes colonized these environments remains unanswered. To address this question, we compared 11 genomes of Thermotoga maritima-like hyperthermophilic bacteria from two environment types: subsurface oil reservoirs in the North Sea and Japan, and marine sites located in the Kuril Islands, Italy and the Azores. We complemented our genomes with Thermotoga DNA from publicly available subsurface metagenomes from North America and Australia. Our analysis revealed complex non-bifurcating evolutionary history of the isolates' genomes, suggesting high amounts of gene flow across all sampled locations, a conjecture supported by numerous recombination events. Genomes from the same type of environment tend to be more similar, and have exchanged more genes with each other than with geographically close isolates from different types of environments. Hence, Thermotoga populations of oil reservoirs do not appear isolated, a requirement of the 'burial and isolation' hypothesis, under which reservoir bacteria are descendants of the isolated communities buried with sediments that over time became oil reservoirs. Instead, our analysis supports a more complex view, where bacteria from subsurface and marine populations have been continuously migrating into the oil reservoirs and influencing their genetic composition. The Thermotoga spp. in the oil reservoirs in the North Sea and Japan probably entered the reservoirs shortly after they were formed. An Australian oil reservoir, on the other hand, was likely colonized very recently, perhaps during human reservoir development. PMID:25500512

  19. Status and threats on seagrass beds using GIS in Vietnam

    NASA Astrophysics Data System (ADS)

    Luong, Cao Van; Thao, Nguyen Van; Komatsu, Teruhisa; Ve, Nguyen Dac; Tien, Dam Duc

    2012-10-01

    Seagrasses, marine flowering plants, are widely distributed along temperate and tropical coastlines of the world. Seagrasses have key ecological roles in coastal ecosystems and can form extensive meadows supporting high biodiversity. Till now, fourteen seagrass species belonging to four families were found in Vietnam: Halophila beccarii, H. decipiens, H. ovalis, H. minor, Thalassia hemprichii, Enhalus acoroides, Ruppia maritima, Halodule pinifolia, H. uninervis, Syringodium isoetifolium, Cymadocea rotundata, C. serrulata and Thalassodendron ciliatum. A total area of seagrass beds in Vietnam is estimated to be approximately 17000 ha by satellite images and GIS technology. In recent years, the distribution areas and densities of seagrass beds in Vietnam have been serious decreased compared with those 10-15 years ago. The decline level depended on the impacts by the natural process, the economical activities and the conservation awareness of local people. Thus, it is different at each coastal area. Generally speaking, the distribution areas and densities of seagrass beds were decreased by more than 50%. Seagrasses on tidal flats in some areas such as Quang Ninh, Hai Phong, Phu Quoc seem to be nearly lost. The distribution areas of seagrass beds in 2009 at Tam Giang-Cau Hai lagoon and Cua Dai estuary was decreased by 50-70% of those in early 1990s.

  20. The structure of Aquifex aeolicus FtsH in the ADP-bound state reveals a C2-symmetric hexamer.

    PubMed

    Vostrukhina, Marina; Popov, Alexander; Brunstein, Elena; Lanz, Martin A; Baumgartner, Renato; Bieniossek, Christoph; Schacherl, Magdalena; Baumann, Ulrich

    2015-06-01

    The crystal structure of a truncated, soluble quadruple mutant of FtsH from Aquifex aeolicus comprising the AAA and protease domains has been determined at 2.96?Å resolution in space group I222. The protein crystallizes as a hexamer, with the protease domain forming layers in the ab plane. Contacts between these layers are mediated by the AAA domains. These are highly disordered in one crystal form, but are clearly visible in a related form with a shorter c axis. Here, adenosine diphosphate (ADP) is bound to each subunit and the AAA ring exhibits twofold symmetry. The arrangement is different from the ADP-bound state of an analogously truncated, soluble FtsH construct from Thermotoga maritima. The pore is completely closed and the phenylalanine residues in the pore line a contiguous path. The protease hexamer is very similar to those described for other FtsH structures. To resolve certain open issues regarding a conserved glycine in the linker between the AAA and protease domains, as well as the active-site switch ?-strand, mutations have been introduced in the full-length membrane-bound protein. Activity analysis of these point mutants reveals the crucial importance of these residues for proteolytic activity and is in accord with previous interpretation of the active-site switch and the importance of the linker glycine residue. PMID:26057670

  1. Anaerobic high-throughput cultivation method for isolation of thermophiles using biomass-derived substrates.

    PubMed

    Hamilton-Brehm, Scott D; Vishnivetskaya, Tatiana A; Allman, Steve L; Mielenz, Jonathan R; Elkins, James G

    2012-01-01

    Flow cytometry (FCM) techniques have been developed for sorting mesophilic organisms, but the difficulty increases if the target microbes are thermophilic anaerobes. We demonstrate a reliable, high-throughput method of screening thermophilic anaerobic organisms using FCM and 96-well plates for growth on biomass-relevant substrates. The method was tested using the cellulolytic thermophiles Clostridium thermocellum (T(opt) = 55 °C), Caldicellulosiruptor obsidiansis (T(opt) = 78 °C) and the fermentative hyperthermophiles, Pyrococcus furiosus (T(opt) = 100 °C) and Thermotoga maritima (T(opt) = 80 °C). Multi-well plates were incubated at various temperatures for approximately 72-120 h and then tested for growth. Positive growth resulting from single cells sorted into individual wells containing an anaerobic medium was verified by OD(600). Depending on the growth substrate, up to 80 % of the wells contained viable cultures, which could be transferred to fresh media. This method was used to isolate thermophilic microbes from Rabbit Creek, Yellowstone National Park (YNP), Wyoming. Substrates for enrichment cultures including crystalline cellulose (Avicel), xylan (from Birchwood), pretreated switchgrass and Populus were used to cultivate organisms that may be of interest to lignocellulosic biofuel production. PMID:22843398

  2. X-ray snapshots of possible intermediates in the time course of synthesis and degradation of protein-bound Fe4S4 clusters

    PubMed Central

    Nicolet, Yvain; Rohac, Roman; Martin, Lydie; Fontecilla-Camps, Juan C.

    2013-01-01

    Fe4S4 clusters are very common versatile prosthetic groups in proteins. Their redox property of being sensitive to O2-induced oxidative damage is, for instance, used by the cell to sense oxygen levels and switch between aerobic and anaerobic metabolisms, as exemplified by the fumarate, nitrate reduction regulator (FNR). Using the hydrogenase maturase HydE from Thermotoga maritima as a template, we obtained several unusual forms of FeS clusters, some of which are associated with important structural changes. These structures represent intermediate states relevant to both FeS cluster assembly and degradation. We observe one Fe2S2 cluster bound by two cysteine persulfide residues. This observation lends structural support to a very recent Raman study, which reported that Fe4S4-to-Fe2S2 cluster conversion upon oxygen exposure in FNR resulted in concomitant production of cysteine persulfide as cluster ligands. Similar persulfide ligands have been observed in vitro for several other Fe4S4 cluster-containing proteins. We have also monitored FeS cluster conversion directly in our protein crystals. Our structures indicate that the Fe4S4-to-Fe2S2 change requires large structural modifications, which are most likely responsible for the dimer–monomer transition in FNR. PMID:23596207

  3. Ex-527 inhibits Sirtuins by exploiting their unique NAD+-dependent deacetylation mechanism

    PubMed Central

    Gertz, Melanie; Fischer, Frank; Nguyen, Giang Thi Tuyet; Lakshminarasimhan, Mahadevan; Schutkowski, Mike; Weyand, Michael; Steegborn, Clemens

    2013-01-01

    Sirtuins are protein deacetylases regulating metabolism and stress responses. The seven human Sirtuins (Sirt1–7) are attractive drug targets, but Sirtuin inhibition mechanisms are mostly unidentified. We report the molecular mechanism of Sirtuin inhibition by 6-chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxamide (Ex-527). Inhibitor binding to potently inhibited Sirt1 and Thermotoga maritima Sir2 and to moderately inhibited Sirt3 requires NAD+, alone or together with acetylpeptide. Crystal structures of several Sirtuin inhibitor complexes show that Ex-527 occupies the nicotinamide site and a neighboring pocket and contacts the ribose of NAD+ or of the coproduct 2’-O-acetyl-ADP ribose. Complex structures with native alkylimidate and thio-analog support its catalytic relevance and show, together with biochemical assays, that only the coproduct complex is relevant for inhibition by Ex-527, which stabilizes the closed enzyme conformation preventing product release. Ex-527 inhibition thus exploits Sirtuin catalysis, and kinetic isoform differences explain its selectivity. Our results provide insights in Sirtuin catalysis and inhibition with important implications for drug development. PMID:23840057

  4. The bacterial ribonuclease P holoenzyme requires specific, conserved residues for efficient catalysis and substrate positioning

    PubMed Central

    Reiter, Nicholas J.; Osterman, Amy K.; Mondragón, Alfonso

    2012-01-01

    RNase P is an RNA-based enzyme primarily responsible for 5?-end pre-tRNA processing. A structure of the bacterial RNase P holoenzyme in complex with tRNAPhe revealed the structural basis for substrate recognition, identified the active site location, and showed how the protein component increases functionality. The active site includes at least two metal ions, a universal uridine (U52), and P RNA backbone moieties, but it is unclear whether an adjacent, bacterially conserved protein loop (residues 52–57) participates in catalysis. Here, mutagenesis combined with single-turnover reaction kinetics demonstrate that point mutations in this loop have either no or modest effects on catalytic efficiency. Similarly, amino acid changes in the ‘RNR’ region, which represent the most conserved region of bacterial RNase P proteins, exhibit negligible changes in catalytic efficiency. However, U52 and two bacterially conserved protein residues (F17 and R89) are essential for efficient Thermotoga maritima RNase P activity. The U52 nucleotide binds a metal ion at the active site, whereas F17 and R89 are positioned >20 Å from the cleavage site, probably making contacts with N?4 and N?5 nucleotides of the pre-tRNA 5?-leader. This suggests a synergistic coupling between transition state formation and substrate positioning via interactions with the leader. PMID:22904083

  5. Crystal structure of levansucrase from the Gram-negative bacterium Gluconacetobacter diazotrophicus.

    PubMed

    Martínez-Fleites, Carlos; Ortíz-Lombardía, Miguel; Pons, Tirso; Tarbouriech, Nicolas; Taylor, Edward J; Arrieta, Juan G; Hernández, Lázaro; Davies, Gideon J

    2005-08-15

    The endophytic Gram-negative bacterium Gluconacetobacter diazotrophicus SRT4 secretes a constitutively expressed levansucrase (LsdA, EC 2.4.1.10), which converts sucrose into fructooligosaccharides and levan. The enzyme is included in GH (glycoside hydrolase) family 68 of the sequence-based classification of glycosidases. The three-dimensional structure of LsdA has been determined by X-ray crystallography at a resolution of 2.5 A (1 A=0.1 nm). The structure was solved by molecular replacement using the homologous Bacillus subtilis (Bs) levansucrase (Protein Data Bank accession code 1OYG) as a search model. LsdA displays a five-bladed beta-propeller architecture, where the catalytic residues that are responsible for sucrose hydrolysis are perfectly superimposable with the equivalent residues of the Bs homologue. The comparison of both structures, the mutagenesis data and the analysis of GH68 family multiple sequences alignment show a strong conservation of the sucrose hydrolytic machinery among levansucrases and also a structural equivalence of the Bs levansucrase Ca2+-binding site to the LsdA Cys339-Cys395 disulphide bridge, suggesting similar fold-stabilizing roles. Despite the strong conservation of the sucrose-recognition site observed in LsdA, Bs levansucrase and GH32 family Thermotoga maritima invertase, structural differences appear around residues involved in the transfructosylation reaction. PMID:15869470

  6. Crystallization and preliminary X-ray analysis of the periplasmic domain of FliP, an integral membrane component of the bacterial flagellar type III protein-export apparatus.

    PubMed

    Fukumura, Takuma; Furukawa, Yukio; Kawaguchi, Tatsuya; Saijo-Hamano, Yumiko; Namba, Keiichi; Imada, Katsumi; Minamino, Tohru

    2014-09-01

    The bacterial flagellar proteins are transported via a specific export apparatus to the distal end of the growing structure for their self-assembly. FliP is an essential membrane component of the export apparatus. FliP has an N-terminal signal peptide and is predicted to have four transmembrane (TM) helices and a periplasmic domain (FliPP) between TM-2 and TM-3. In this study, FliPP from Thermotoga maritima (TmFliPP) and its selenomethionine derivative (SeMet-TmFliPP) were purified and crystallized. TmFliPP formed a homotetramer in solution. Crystals of TmFliPP and SeMet-TmFliPP were obtained by the hanging-drop vapour-diffusion technique with 2-methyl-2,4-pentanediol as a precipitant. These two crystals grew in the hexagonal space group P6222 or P6422, with unit-cell parameters a = b = 114.9, c = 193.8?Å. X-ray diffraction data were collected from crystals of TmFliPP and SeMet-TmFliPP to 2.4 and 2.8?Å resolution, respectively. PMID:25195894

  7. Molecular details of ligand selectivity determinants in a promiscuous ?-glucan periplasmic binding protein

    PubMed Central

    2013-01-01

    Background Members of the periplasmic binding protein (PBP) superfamily utilize a highly conserved inter-domain ligand binding site that adapts to specifically bind a chemically diverse range of ligands. This paradigm of PBP ligand binding specificity was recently altered when the structure of the Thermotoga maritima cellobiose-binding protein (tmCBP) was solved. The tmCBP binding site is bipartite, comprising a canonical solvent-excluded region (subsite one), adjacent to a solvent-filled cavity (subsite two) where specific and semi-specific ligand recognition occur, respectively. Results A molecular level understanding of binding pocket adaptation mechanisms that simultaneously allow both ligand specificity at subsite one and promiscuity at subsite two has potentially important implications in ligand binding and drug design studies. We sought to investigate the determinants of ligand binding selectivity in tmCBP through biophysical characterization of tmCBP in the presence of varying ?-glucan oligosaccharides. Crystal structures show that whilst the amino acids that comprise both the tmCBP subsite one and subsite two binding sites remain fixed in conformation regardless of which ligands are present, the rich hydrogen bonding potential of water molecules may facilitate the ordering and the plasticity of this unique PBP binding site. Conclusions The identification of the roles these water molecules play in ligand recognition suggests potential mechanisms that can be utilized to adapt a single ligand binding site to recognize multiple distinct ligands. PMID:24090243

  8. Triad pattern algorithm for predicting strong promoter candidates in bacterial genomes

    PubMed Central

    Dekhtyar, Michael; Morin, Amelie; Sakanyan, Vehary

    2008-01-01

    Background Bacterial promoters, which increase the efficiency of gene expression, differ from other promoters by several characteristics. This difference, not yet widely exploited in bioinformatics, looks promising for the development of relevant computational tools to search for strong promoters in bacterial genomes. Results We describe a new triad pattern algorithm that predicts strong promoter candidates in annotated bacterial genomes by matching specific patterns for the group I ?70 factors of Escherichia coli RNA polymerase. It detects promoter-specific motifs by consecutively matching three patterns, consisting of an UP-element, required for interaction with the ? subunit, and then optimally-separated patterns of -35 and -10 boxes, required for interaction with the ?70 subunit of RNA polymerase. Analysis of 43 bacterial genomes revealed that the frequency of candidate sequences depends on the A+T content of the DNA under examination. The accuracy of in silico prediction was experimentally validated for the genome of a hyperthermophilic bacterium, Thermotoga maritima, by applying a cell-free expression assay using the predicted strong promoters. In this organism, the strong promoters govern genes for translation, energy metabolism, transport, cell movement, and other as-yet unidentified functions. Conclusion The triad pattern algorithm developed for predicting strong bacterial promoters is well suited for analyzing bacterial genomes with an A+T content of less than 62%. This computational tool opens new prospects for investigating global gene expression, and individual strong promoters in bacteria of medical and/or economic significance. PMID:18471287

  9. Paleobiology of the Sand Beneath the Valders Diamicton at Valders, Wisconsin

    NASA Astrophysics Data System (ADS)

    Maher, Louis J.; Miller, Norton G.; Baker, Richard G.; Curry, B. Brandon; Mickelson, David M.

    1998-03-01

    Previously undescribed pollen, plant macrofossils, molluscs, and ostracodes were recovered from a 2.5-m-thick glaciolacustrine unit of silty sand and clay at Valders, Wisconsin. The interstadial sediment was deposited about 12,200 14C yr B.P. after retreat of the Green Bay lobe that deposited diamicton of the Horicon Formation, and before advance of the Lake Michigan lobe that deposited the red-brown diamicton of the Valders Member of the Kewaunee Formation. Fluctuations of abundance of Candona subtriangulata, Cytherissa lacustris,and three other species define four ostracode biozones in the lower 1.7 m, suggesting an open lake environment that oscillated in depth and proximity to glacial ice. Pollen is dominated by Piceaand Artemisia,but the low percentages of many other types of long-distance origin suggest that the terrestrial vegetation was open and far from the forest border. The upper part of the sediment, a massive sand deposited in either a shallow pond or a sluggish stream, contains a local concentration of plant macrofossils. The interpretation of a cold open environment is supported by the plant macrofossils of more than 20 species, dominated by those of open mineral soils ( Arenaria rubella, Cerastium alpinumtype, Silene acaulis, Sibbaldia procumbens, Dryas integrifolia, Vaccinium uliginosumvar. alpinum, Armeria maritima,etc.) that in North America occur largely in the tundra and open tundra-forest ecotone of northern Canada. Ice-wedge casts occur in the sand.

  10. Biomimetic assembly and activation of [FeFe]-hydrogenases.

    PubMed

    Berggren, G; Adamska, A; Lambertz, C; Simmons, T R; Esselborn, J; Atta, M; Gambarelli, S; Mouesca, J-M; Reijerse, E; Lubitz, W; Happe, T; Artero, V; Fontecave, M

    2013-07-01

    Hydrogenases are the most active molecular catalysts for hydrogen production and uptake, and could therefore facilitate the development of new types of fuel cell. In [FeFe]-hydrogenases, catalysis takes place at a unique di-iron centre (the [2Fe] subsite), which contains a bridging dithiolate ligand, three CO ligands and two CN(-) ligands. Through a complex multienzymatic biosynthetic process, this [2Fe] subsite is first assembled on a maturation enzyme, HydF, and then delivered to the apo-hydrogenase for activation. Synthetic chemistry has been used to prepare remarkably similar mimics of that subsite, but it has failed to reproduce the natural enzymatic activities thus far. Here we show that three synthetic mimics (containing different bridging dithiolate ligands) can be loaded onto bacterial Thermotoga maritima HydF and then transferred to apo-HydA1, one of the hydrogenases of Chlamydomonas reinhardtii algae. Full activation of HydA1 was achieved only when using the HydF hybrid protein containing the mimic with an azadithiolate bridge, confirming the presence of this ligand in the active site of native [FeFe]-hydrogenases. This is an example of controlled metalloenzyme activation using the combination of a specific protein scaffold and active-site synthetic analogues. This simple methodology provides both new mechanistic and structural insight into hydrogenase maturation and a unique tool for producing recombinant wild-type and variant [FeFe]-hydrogenases, with no requirement for the complete maturation machinery. PMID:23803769

  11. Hydrogen production by hyperthermophilic and extremely thermophilic bacteria and archaea: mechanisms for reductant disposal.

    PubMed

    Verhaart, Marcel R A; Bielen, Abraham A M; van der Oost, John; Stams, Alfons J M; Kengen, Servé W M

    2010-01-01

    Hydrogen produced from biomass by bacteria and archaea is an attractive renewable energy source. However, to make its application more feasible, microorganisms are needed with high hydrogen productivities. For several reasons, hyperthermophilic and extremely thermophilic bacteria and archaea are promising is this respect. In addition to the high polysaccharide-hydrolysing capacities of many of these organisms, an important advantage is their ability to use most of the reducing equivalents (e.g. NADH, reduced ferredoxin) formed during glycolysis for the production of hydrogen, enabling H2/hexose ratios of between 3.0 and 4.0. So, despite the fact that the hydrogen-yielding reactions, especially the one from NADH, are thermodynamically unfavourable, high hydrogen yields are obtained. In this review we focus on three different mechanisms that are employed by a few model organisms, viz. Caldicellulosiruptor saccharolyticus and Thermoanaerobacter tengcongensis, Thermotoga maritima, and Pyrococcus furiosus, to efficiently produce hydrogen. In addition, recent developments to improve hydrogen production by hyperthermophilic and extremely thermophilic bacteria and archaea are discussed. PMID:20662387

  12. A thermostable exo-?-fructosidase immobilised through rational design.

    PubMed

    Martínez, Duniesky; Cutiño-Avila, Bessy; Pérez, Enrique Rosendo; Menéndez, Carmen; Hernández, Lázaro; Del Monte-Martínez, Alberto

    2014-02-15

    Thermotoga maritima exo-?-fructosidase (BfrA) secreted by a recombinant Pichia pastoris strain was optimally immobilised on Glyoxyl-Sepharose CL 4B using the Rational Design of Immobilised Derivatives (RDID) strategy. Covalent attachment of the N-glycosylated BfrA onto the activated support at pH 10 allowed total recovery of the loaded enzyme and its activity. The immobilisation process caused no variation in the catalytic properties of the enzyme and allowed further enhancement of the thermal stability. Complete inversion of cane sugar (2.04 M) in a batch stirred tank reactor at 60 °C was achieved with a productivity of 22.2 g of substrate hydrolysed/gram of biocatalyst/hour. Half-life of the immobilised enzyme of 5 days at 60 °C was determined in a continuously operated fixed-bed column reactor. Our results promote the applicability of the BfrA-immobilised biocatalyst for the complete hydrolysis of concentrated sucrose solutions under industrial conditions, especially at a high reaction temperature. PMID:24128552

  13. Analysis of 13 asteroid lightcurves obtained at the Palmer Divide Observatory

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.

    2006-06-01

    The lightcurves for the following asteroids were obtained and then analyzed to find the synodic period and amplitude. 321 Florentina: 2.8711±0.0003h, 0.37±0.02m; 787 Moskva: 6.056±0.001h, 0.61±0.02m; 839 Valborg: 10.366±0.005h, 0.14±0.02m; 912 Maritima: 48.43±0.05h, >0.12±0.02m; 1176 Lucidor: 4.0791±0.0006h, 0.06±0.02m; 1862 Apollo: 3.0680±0.0002h, 0.30-1.20±0.02m; 2266 Tchaikovsky: 4.883±0.003h, 0.04±0.01m; 2951 Perepadin: 4.7808±0.0001h, 0.60±0.02m; 5108 Lubeck: 8.769±0.003, 0.43±0.02m; (17864) 1998 KK38: 6.56±0.01h, 0.17±0.02m; (18582) 1997 XK9: 114±10h, 0.94±0.02m; (20231) 1997 YK: 48.2±0.1h, >0.22±0.02m. Asteroid 868 Lova was also observed but its long period is only constrained as >24h.

  14. Palynological analysis of camelid coprolites: seasonality in the use of the site Cerro Casa de Piedra 7 (Santa Cruz, Argentina)

    NASA Astrophysics Data System (ADS)

    Velázquez, Nadia Jimena; Burry, Lidia Susana; Fugassa, Martín Horacio; Civalero, María Teresa; Aschero, Carlos Alberto

    2014-01-01

    Palynological, palaeoparasitological and paleobotanical studies of coprolites found in archaeological sites from Perito Moreno National Park (47°57?S72°05?W) yielded information on diet, palaeoenvironment and health. These studies allowed adding evidence to the reconstruction of life history of the hunter-gatherers that inhabited Patagonia during the Holocene. We examined the season of the year when camelid Lama guanicoe coprolites (5400 ± 64 yr 14C BP to 9640 ± 190 yr 14C BP) were deposited at Cerro Casa de Piedra 7 (site CCP7). The study used palynological evidence and comparison with pollen spectra of modern feces collected during summer, fall, winter and spring of 2010. The dominant types were: pollen of Nothofagus, Empetrum rubrum, Asteraceae subfam. Asteroideae, Nassauvia, Caryophyllaceae and Poaceae; fern spores; remains of Eimeria macusaniensis; and plant remains of Poaceae, Festuca pallescens, Stipa speciosa, Armeria maritima, Gaultheria mucronata and E. rubrum. Pollen spectra of modern and fossil feces were used for multivariate analysis. Coprolites associated to fall and winter modern feces. These results and those obtained from pollen concentration values and the presence of pollen types indicators of seasonality, allowed the determination of summer, fall and winter coprolites. However, caution must be taken with the seasonality results of coprolites dated earlier than 9000 years BP since the environmental conditions differed from now. The site was probably a camelid shelter during the unfavorable seasons.

  15. Structure-guided discovery of new deaminase enzymes.

    PubMed

    Hitchcock, Daniel S; Fan, Hao; Kim, Jungwook; Vetting, Matthew; Hillerich, Brandan; Seidel, Ronald D; Almo, Steven C; Shoichet, Brian K; Sali, Andrej; Raushel, Frank M

    2013-09-18

    A substantial challenge for genomic enzymology is the reliable annotation for proteins of unknown function. Described here is an interrogation of uncharacterized enzymes from the amidohydrolase superfamily using a structure-guided approach that integrates bioinformatics, computational biology, and molecular enzymology. Previously, Tm0936 from Thermotoga maritima was shown to catalyze the deamination of S-adenosylhomocysteine (SAH) to S-inosylhomocysteine (SIH). Homologues of Tm0936 homologues were identified, and substrate profiles were proposed by docking metabolites to modeled enzyme structures. These enzymes were predicted to deaminate analogues of adenosine including SAH, 5'-methylthioadenosine (MTA), adenosine (Ado), and 5'-deoxyadenosine (5'-dAdo). Fifteen of these proteins were purified to homogeneity, and the three-dimensional structures of three proteins were determined by X-ray diffraction methods. Enzyme assays supported the structure-based predictions and identified subgroups of enzymes with the capacity to deaminate various combinations of the adenosine analogues, including the first enzyme (Dvu1825) capable of deaminating 5'-dAdo. One subgroup of proteins, exemplified by Moth1224 from Moorella thermoacetica, deaminates guanine to xanthine, and another subgroup, exemplified by Avi5431 from Agrobacterium vitis S4, deaminates two oxidatively damaged forms of adenine: 2-oxoadenine and 8-oxoadenine. The sequence and structural basis of the observed substrate specificities were proposed, and the substrate profiles for 834 protein sequences were provisionally annotated. The results highlight the power of a multidisciplinary approach for annotating enzymes of unknown function. PMID:23968233

  16. Structure-Guided Discovery of New Deaminase Enzymes

    PubMed Central

    Hitchcock, Daniel S.; Fan, Hao; Kim, Jungwook; Vetting, Matthew; Hillerich, Brandan; Seidel, Ronald D.; Almo, Steven C.; Shoichet, Brian K.; Sali, Andrej; Raushel, Frank M.

    2013-01-01

    A substantial challenge for genomic enzymology is the reliable annotation for proteins of unknown function. Described here is an interrogation of uncharacterized enzymes from the amidohydrolase superfamily using a structure-guided approach that integrates bioinformatics, computational biology and molecular enzymology. Previously, Tm0936 from Thermotoga maritima was shown to catalyze the deamination of S-adenosylhomocysteine (SAH) to Sinosylhomocysteine (SIH). Homologues of Tm0936 homologues were identified, and substrate profiles were proposed by docking metabolites to modeled enzyme structures. These enzymes were predicted to deaminate analogues of adenosine including SAH, 5’-methylthioadenosine (MTA), adenosine (Ado), and 5’-deoxyadenosine (5’-dAdo). Fifteen of these proteins were purified to homogeneity and the three-dimensional structures of three proteins were determined by X-ray diffraction methods. Enzyme assays supported the structure-based predictions and identified subgroups of enzymes with the capacity to deaminate various combinations of the adenosine analogues, including the first enzyme (Dvu1825) capable of deaminating 5’-dAdo. One subgroup of proteins, exemplified by Moth1224 from Moorella thermoacetica, deaminates guanine to xanthine and another subgroup, exemplified by Avi5431 from Agrobacterium vitis S4, deaminates two oxidatively damaged forms of adenine: 2-oxoadenine and 8-oxoadenine. The sequence and structural basis of the observed substrate specificities was proposed and the substrate profiles for 834 protein sequences were provisionally annotated. The results highlight the power of a multidisciplinary approach for annotating enzymes of unknown function. PMID:23968233

  17. Na+-pyrophosphatase: a novel primary sodium pump.

    PubMed

    Malinen, Anssi M; Belogurov, Georgiy A; Baykov, Alexander A; Lahti, Reijo

    2007-07-31

    Membrane-bound pyrophosphatase (PPase) is commonly believed to couple pyrophosphate (PPi) hydrolysis to H+ transport across the membrane. Here, we demonstrate that two newly isolated bacterial membrane PPases from the mesophile Methanosarcina mazei (Mm-PPase) and the moderate thermophile Moorella thermoacetica and a previously described PPase from the hyperthermophilic bacterium Thermotoga maritima catalyze Na+ rather than H+ transport into Escherichia coli inner membrane vesicles (IMV). When assayed in uncoupled IMV, the three PPases exhibit an absolute requirement for Na+ but display the highest hydrolyzing activity in the presence of both Na+ and K+. Steady-state kinetic analysis of PPi hydrolysis by Mm-PPase revealed two Na+ binding sites. One of these sites can also bind K+, resulting in a 10-fold increase in the affinity of the other site for Na+ and a 2-fold increase in maximal velocity. PPi-driven 22Na+ transport into IMV containing Mm-PPase was unaffected by the protonophore carbonyl cyanide m-chlorophenylhydrazone, inhibited by the Na+ ionophore monensin, and activated by the K+ ionophore valinomycin. The Na+ transport was accompanied by the generation of a positive inside membrane potential as reported by Oxonol VI. These findings define Na+-dependent PPases as electrogenic Na+ pumps. Phylogenetic analysis suggests that ancient gene duplication preceded the split of Na+- and H+-PPases. PMID:17605473

  18. Impacts of the 1998 and 2010 mass coral bleaching events on the Western Gulf of Thailand

    NASA Astrophysics Data System (ADS)

    Sutthacheep, Makamas; Yucharoen, Mathinee; Klinthong, Wanlaya; Pengsakun, Sittiporn; Sangmanee, Kanwara; Yeemin, Thamasak

    2013-11-01

    A long-term study of coral reef ecology in the Gulf of Thailand provides a good opportunity to examine the temporal variation on the impact of mass coral bleaching at those reef sites. We compared the bleaching and mortality of corals between the mass bleaching events in 1998 and 2010 at a coral community in the Western Gulf of Thailand. The aim was to identify the coral species which were most likely to suffer from (and to be able to tolerate) changes in seawater temperature. Significant differences in the susceptibility of the coral taxa to bleaching events between the years 1998 and 2010 and among coral species were documented. Bleaching was significantly different between the most dominant corals. Diploastrea heliopora was the most resistant coral to bleaching in both years. Some coral species showed more resistance to bleaching in 2010. The coral mortality following the mass bleaching events in 1998 and 2010 varied significantly between the years and the coral taxa. Mortality of some dominant coral taxa was also lower in 2010. Seven coral species, i.e. Astreopora myriophthalma, Pachyseris rugosa, Turbinaria mesenterina, Goniastrea pectinata, Favia pallida, F. maritima, Favites halicora, Platygyra daedalea and Galaxea fascicularis, were tolerant to the coral bleaching events. An ecosystem-based approach to managing coral reefs in the Gulf of Thailand is needed to identify appropriate marine protected area networks and to strengthen marine and coastal resource policies in order to build coral reef resilience.

  19. Crystal structure of a 4-thiouridine synthetase–RNA complex reveals specificity of tRNA U8 modification

    PubMed Central

    Neumann, Piotr; Naumann, Peter-Thomas; Erwin, Whitney M.; Lauhon, Charles T.; Ficner, Ralf

    2014-01-01

    In prokaryotes and archaea transfer ribonucleic acid (tRNA) stability as well as cellular UV protection relies on the post-transcriptional modification of uracil at position 8 (U8) of tRNAs by the 4-thiouridine synthetase ThiI. Here, we report three crystal structures of ThiI from Thermotoga maritima in complex with a truncated tRNA. The RNA is mainly bound by the N-terminal ferredoxin-like domain (NFLD) and the THUMP domain of one subunit within the ThiI homo-dimer thereby positioning the U8 close to the catalytic center in the pyrophosphatase domain of the other subunit. The recognition of the 3’-CCA end by the THUMP domain yields a molecular ruler defining the specificity for U8 thiolation. This first structure of a THUMP/NFLD-RNA complex might serve as paradigm for the RNA recognition by THUMP domains of other proteins. The ternary ThiI–RNA–ATP complex shows no significant structural changes due to adenosine triphosphate (ATP) binding, but two different states of active site loops are observed independent of the nucleotide loading state. Thereby conformational changes of the active site are coupled with conformational changes of the bound RNA. The ThiI–RNA complex structures indicate that full-length tRNA has to adopt a non-canonical conformation upon binding to ThiI. PMID:24705700

  20. Characterization of protomer interfaces in HslV protease; the bacterial homologue of 20S proteasome.

    PubMed

    Azim, M Kamran; Noor, Sajid

    2007-06-01

    HslVU, a two-component proteasome-related prokaryotic system is composed of HslV protease and HslU ATPase. HslV protomers assemble in a dodecamer of two-stacked hexameric rings that form a complex with HslU hexamers. The intra- and inter-ring protomer interfaces in the HslV dodecamer underpin the integrity and functionality of HslVU. Structural characterization of HslV from different bacteria illustrated considerable differences in interacting residues, accessible surface and gap volumes at the intra-ring interface that is primarily stabilized by polar interactions. Amino acid residues Lys28, Arg83 and Asp111 have envisaged as hot spots at this HslU-interacting interface. The inter-ring interfaces that are made up of side chain packing of hydrophobic residues are structurally conserved. Hyperthermostable bacterium T. maritima HslV has extensively networked polar/nonpolar interactions and highly packed environment at all interfaces. Present data demonstrates that HslV protomer interfaces perform distinct functions; whereas intra-ring interface participates in HslV:HslU interaction resulting in allosteric activation of HslV protease by HslU, the inter-ring interfaces uphold the oligomeric form of HslV. PMID:17522969

  1. New crystal forms of Diocleinae lectins in the presence of different dimannosides.

    PubMed

    Moreno, Frederico Bruno Mendes Batista; Bezerra, Gustavo Arruda; de Oliveira, Taianá Maia; de Souza, Emmanuel Prata; da Rocha, Bruno Anderson Matias; Benevides, Raquel Guimarães; Delatorre, Plínio; Cavada, Benildo Sousa; de Azevedo, Walter Filgueira

    2006-11-01

    Studying the interactions between lectins and sugars is important in order to explain the differences observed in the biological activities presented by the highly similar proteins of the Diocleinae subtribe. Here, the crystallization and preliminary X-ray data of Canavalia gladiata lectin (CGL) and C. maritima lectin (CML) complexed with Man(alpha1-2)Man(alpha1)OMe, Man(alpha1-3)Man(alpha1)OMe and Man(alpha1-4)Man(alpha1)OMe in two crystal forms [the complexes with Man(alpha1-3)Man(alpha1)OMe and Man(alpha1-4)Man(alpha1)OMe crystallized in space group P3(2) and those with Man(alpha1-2)Man(alpha1)OMe crystallized in space group I222], which differed from those of the native proteins (P2(1)2(1)2 for CML and C222 for CGL), are reported. The crystal complexes of ConA-like lectins with Man(alpha1-4)Man(alpha1)OMe are reported here for the first time. PMID:17077488

  2. Effects of Canavalia lectins on acute inflammation in sensitized and non-sensitized rats.

    PubMed

    Pinto, Nilson Vieira; Cavada, Benildo Sousa; Brito, Lucas Ferreira; Pereira, Ronniery Ilario; da Silva, Mayara Torquato Lima; Castro, Rondinelle Ribeiro; de Freitas Pires, Alana; Assreuy, Ana Maria Sampaio

    2013-06-01

    The anti-inflammatory activity of Canavalia seed lectins (Canavalia gladiata [CGL], Canavalia maritima [ConM] and Canavalia brasiliensis [ConBr]) was evaluated by intravenous administration in rats. In non-sensitized rats, cellular edema elicited by carrageenan was reduced (45-51 %) by ConM and (44-59 %) by CGL. Osmotic edema elicited by dextran was reduced by ConM and CGL in 27 % and 29 %. ConM and CGL reduced the edema elicited by L-arginine in 53 % and that of prostaglandin E2 in 48 % and 36 %. Leukocyte migration elicited by carrageenan was reduced in 49 % by ConM and in 55 % by CGL (attenuated in 4× by glucose) and peritoneal TNF-? content in 82 %. In rats sensitized, ConM inhibited the paw edema and leukocyte migration elicited by ovalbumin in 34 % and 70 %. ConM and CGL are anti-inflammatory, mainly in cellular events mediated by prostaglandin E?, nitric oxide and TNF-? in non-sensitized rats. However, only ConM is anti-inflammatory in sensitized rats. CGL effect involves the lectin domain. PMID:23377963

  3. A ConA-like lectin from Dioclea guianensis Benth. has antifungal activity against Colletotrichum gloeosporioides, unlike its homologues, ConM and ConA.

    PubMed

    Araújo-Filho, José H; Vasconcelos, Ilka M; Martins-Miranda, Aparecida S; Gondim, Darcy M F; Oliveira, José T A

    2010-04-14

    This study reports on the antifungal activity of Dgui, a ConA-like lectin from Dioclea guianensis seeds. Dgui inhibited conidial germination but not mycelial growth of Colletotrichum gloeosporioides. The lectins ConA and ConM from Canavalia ensiformis and Canavalia maritima, respectively, share high levels of amino acid sequence similarity (>84%) with Dgui and have the same specificity toward glucose/mannose but had no effect on the fungus. Fluorescence microscopy showed that both Dgui and ConM bind to C. gloeosporioides ungerminated conidia. However, Dgui did not bind to C. gloeosporioides germinated conidia and germ tubes and was not inhibitory to mycelial growth. Because only Dgui inhibited germination of the fungus, C. gloeosporioides conidia might have surface-specific germination targets recognized by Dgui but not by its homologues, ConM and ConA. Therefore, Dgui is a candidate for biotechnological approaches for improving the resistance of various nutritionally and commercially important crops that are affected by C. gloeosporioides. PMID:20201549

  4. Use of digital multispectral videography to assess seagrass distribution in San Quintin Bay, Baja California, Mexico

    USGS Publications Warehouse

    Ward, D.H.; Tibbitts, T.L.; Morton, Alexandra; Carrera-Gonzalez, Eduardo; Kempka, R.

    2004-01-01

    Apparent threats to the spatial distribution of seagrass in San Quinti??n Bay prompted us to make a detailed assessment of habitats in the bay. Six coastal habitats and three seagrass subclasses were delineated using airborne digital multispectral videography (DMSV), Eelgrass, Zostera marina, was the predominant seagrass and covered 40% (1949 ha) of the areal extent of the bay in 1999. Eelgrass grew over a wide range of tidal depths from about -3.0 in mean lower low water (MLLW) to about 1.0 m MLLW, but greatest spatial extent occurred in intertidal areas -0.6 m to 1.0 m MLLW. Exposed-continuous (i.e., high density) eelgrass was the most abundant habitat in the bay. Widgeongrass, Ruppia maritima, was the only other seagrass present and covered 3% (136 ha) of the areal extent of the entire bay. Widgeongrass grew in single species stands in the upper intertidal (??? 0.4 MLLW) and intermixed with eelgrass at lower tidal depths. Overall accuracy of the six habitat classes and three subclasses in the DMSV map was relatively high at 84%. Our detailed map of San Quintin Bay can be used in future change detection analyses to monitor the health of seagrasses in the bay.

  5. Improving small-angle X-ray scattering data for structural analyses of the RNA world.

    PubMed

    Rambo, Robert P; Tainer, John A

    2010-03-01

    Defining the shape, conformation, or assembly state of an RNA in solution often requires multiple investigative tools ranging from nucleotide analog interference mapping to X-ray crystallography. A key addition to this toolbox is small-angle X-ray scattering (SAXS). SAXS provides direct structural information regarding the size, shape, and flexibility of the particle in solution and has proven powerful for analyses of RNA structures with minimal requirements for sample concentration and volumes. In principle, SAXS can provide reliable data on small and large RNA molecules. In practice, SAXS investigations of RNA samples can show inconsistencies that suggest limitations in the SAXS experimental analyses or problems with the samples. Here, we show through investigations on the SAM-I riboswitch, the Group I intron P4-P6 domain, 30S ribosomal subunit from Sulfolobus solfataricus (30S), brome mosaic virus tRNA-like structure (BMV TLS), Thermotoga maritima asd lysine riboswitch, the recombinant tRNA(val), and yeast tRNA(phe) that many problems with SAXS experiments on RNA samples derive from heterogeneity of the folded RNA. Furthermore, we propose and test a general approach to reducing these sample limitations for accurate SAXS analyses of RNA. Together our method and results show that SAXS with synchrotron radiation has great potential to provide accurate RNA shapes, conformations, and assembly states in solution that inform RNA biological functions in fundamental ways. PMID:20106957

  6. The crystal structure of spermidine synthase with a multisubstrate adduct inhibitor

    PubMed Central

    Korolev, Sergey; Ikeguchi, Yoshihiko; Skarina, Tatiana; Beasley, Steven; Arrowsmith, Cheryl; Edwards, Aled; Joachimiak, Andrzej; Pegg, Anthony E.; Savchenko, Alexei

    2009-01-01

    Polyamines are essential in all branches of life. Spermidine synthase (putrescine aminopropyltransferase, PAPT) catalyzes the biosynthesis of spermidine, a ubiquitous polyamine. The crystal structure of the PAPT from Thermotoga maritima (TmPAPT) has been solved to 1.5 Å resolution in the presence and absence of AdoDATO (S-adenosyl-1,8-diamino-3-thiooctane), a compound containing both substrate and product moieties. This, the first structure of an aminopropyltransferase, reveals deep cavities for binding substrate and cofactor, and a loop that envelops the active site. The AdoDATO binding site is lined with residues conserved in PAPT enzymes from bacteria to humans, suggesting a universal catalytic mechanism. Other conserved residues act sterically to provide a structural basis for polyamine specificity. The enzyme is tetrameric; each monomer consists of a C-terminal domain with a Rossmann-like fold and an N-terminal ?-stranded domain. The tetramer is assembled using a novel barrel-type oligomerization motif. PMID:11731804

  7. Phylogenetic Analyses of Meloidogyne Small Subunit rDNA

    PubMed Central

    De Ley, Irma Tandingan; De Ley, Paul; Vierstraete, Andy; Karssen, Gerrit; Moens, Maurice; Vanfleteren, Jacques

    2002-01-01

    Phylogenies were inferred from nearly complete small subunit (SSU) 18S rDNA sequences of 12 species of Meloidogyne and 4 outgroup taxa (Globodera pallida, Nacobbus abberans, Subanguina radicicola, and Zygotylenchus guevarai). Alignments were generated manually from a secondary structure model, and computationally using ClustalX and Treealign. Trees were constructed using distance, parsimony, and likelihood algorithms in PAUP* 4.0b4a. Obtained tree topologies were stable across algorithms and alignments, supporting 3 clades: clade I = [M. incognita (M. javanica, M. arenaria)]; clade II = M. duytsi and M. maritima in an unresolved trichotomy with (M. hapla, M. microtyla); and clade III = (M. exigua (M. graminicola, M. chitwoodi)). Monophyly of [(clade I, clade II) clade III] was given maximal bootstrap support (mbs). M. artiellia was always a sister taxon to this joint clade, while M. ichinohei was consistently placed with mbs as a basal taxon within the genus. Affinities with the outgroup taxa remain unclear, although G. pallida and S. radicicola were never placed as closest relatives of Meloidogyne. Our results show that SSU sequence data are useful in addressing deeper phylogeny within Meloidogyne, and that both M. ichinohei and M. artiellia are credible outgroups for phylogenetic analysis of speciations among the major species. PMID:19265950

  8. Ecological correlates of variable organ sizes and fat loads in the most northerly-wintering shorebirds

    USGS Publications Warehouse

    Ruthrauff, Daniel R.; Dekinga, A.; Gill, R.E., Jr.; Summers, R.W.; Piersma, T.

    2013-01-01

    Shorebirds at northern latitudes during the nonbreeding season typically carry relatively large lipid stores and exhibit an up-regulation of lean tissues associated with digestion and thermogenesis. Intraspecific variation in these tissues across sites primarily reflects differences in environmental conditions. Rock (Calidris ptilocnemis (Coues, 1873)) and Purple (Calidris maritima (Brünnich, 1764)) sandpipers are closely related species having the most northerly nonbreeding distributions among shorebirds, living at latitudes up to 61°N in Cook Inlet, Alaska, and up to 71°N in northern Norway, respectively. Cook Inlet is the coldest known site used by nonbreeding shorebirds, and the region’s mudflats annually experience extensive coverage of foraging sites by sea and shore-fast ice. Accordingly, Rock Sandpipers increase their fat stores to nearly 20% of body mass during winter. In contrast, Purple Sandpipers exploit predictably ice-free rocky intertidal foraging sites and maintain low (<6.5%) fat stores. Rock Sandpipers increase the mass of lean tissues from fall to winter, including contour feathers, stomach, and liver components. They also have greater lean pectoralis and supracoracoideus muscle and liver and kidney tissues compared with Purple Sandpipers in winter. This demonstrates a combined emphasis on digestive processes and thermogenesis, whereas Purple Sandpipers primarily augment organs associated with digestive processes. The high winter fat loads and increased lean tissues of Rock Sandpipers in Cook Inlet reflect the region’s persistent cold and abundant but sporadically unavailable food resources.

  9. A study of antioxidant activity, enzymatic inhibition and in vitro toxicity of selected traditional sudanese plants with anti-diabetic potential

    PubMed Central

    2014-01-01

    Background Diabetes mellitus is a chronic metabolic disease with life-threatening complications. Despite the enormous progress in conventional medicine and pharmaceutical industry, herbal-based medicines are still a common practice for the treatment of diabetes. This study evaluated ethanolic and aqueous extracts of selected Sudanese plants that are traditionally used to treat diabetes. Methods Extraction was carried out according to method described by Sukhdev et. al. and the extracts were tested for their glycogen phosphorylase inhibition, Brine shrimp lethality and antioxidant activity using (DPPH) radical scavenging activity and iron chelating activity. Extracts prepared from the leaves of Ambrosia maritima, fruits of Foeniculum vulgare and Ammi visnaga, exudates of Acacia Senegal, and seeds of Sesamum indicum and Nigella sativa. Results Nigella sativa ethanolic extract showed no toxicity on Brine shrimp Lethality Test, while its aqueous extract was toxic. All other extracts were highly toxic and ethanolic extracts of Foeniculum vulgare exhibited the highest toxicity. All plant extracts with exception of Acacia senegal revealed significant antioxidant activity in DPPH free radical scavenging assay. Conclusions These results highly agree with the ethnobotanical uses of these plants as antidiabetic. This study endorses further studies on plants investigated, to determine their potential for type 2 diabetes management. Moreover isolation and identification of active compounds are highly recommended. PMID:24885334

  10. Construction and transformation of a Thermotoga-E. coli shuttle vector

    PubMed Central

    2012-01-01

    Background Thermotoga spp. are attractive candidates for producing biohydrogen, green chemicals, and thermostable enzymes. They may also serve as model systems for understanding life sustainability under hyperthermophilic conditions. A lack of genetic tools has hampered the investigation and application of these organisms. This study aims to develop a genetic transfer system for Thermotoga spp. Results Methods for preparing and handling Thermotoga solid cultures under aerobic conditions were optimized. A plating efficiency of ~50% was achieved when the bacterial cells were embedded in 0.3% Gelrite. A Thermotoga-E. coli shuttle vector pDH10 was constructed using pRQ7, a cryptic mini-plasmid found in T. sp. RQ7. Plasmid pDH10 was introduced to T. maritima and T. sp. RQ7 by electroporation and liposome-mediated transformation. Transformants were isolated, and the transformed kanamycin resistance gene (kan) was detected from the plasmid DNA extracts of the recombinant strains by PCR and was confirmed by restriction digestions. The transformed DNA was stably maintained in both Thermotoga and E. coli even without the selective pressure. Conclusions Thermotoga are transformable by multiple means. Recombinant Thermotoga strains have been isolated for the first time. A heterologous kan gene is functionally expressed and stably maintained in Thermotoga. PMID:22225774

  11. Rising from the sea: correlations between sulfated polysaccharides and salinity in plants.

    PubMed

    Aquino, Rafael S; Grativol, Clicia; Mourão, Paulo A S

    2011-01-01

    High salinity soils inhibit crop production worldwide and represent a serious agricultural problem. To meet our ever-increasing demand for food, it is essential to understand and engineer salt-resistant crops. In this study, we evaluated the occurrence and function of sulfated polysaccharides in plants. Although ubiquitously present in marine algae, the presence of sulfated polysaccharides among the species tested was restricted to halophytes, suggesting a possible correlation with salt stress or resistance. To test this hypothesis, sulfated polysaccharides from plants artificially and naturally exposed to different salinities were analyzed. Our results revealed that the sulfated polysaccharide concentration, as well as the degree to which these compounds were sulfated in halophytic species, were positively correlated with salinity. We found that sulfated polysaccharides produced by Ruppia maritima Loisel disappeared when the plant was cultivated in the absence of salt. However, subjecting the glycophyte Oryza sativa Linnaeus to salt stress did not induce the biosynthesis of sulfated polysaccharides but increased the concentration of the carboxylated polysaccharides; this finding suggests that negatively charged cell wall polysaccharides might play a role in coping with salt stress. These data suggest that the presence of sulfated polysaccharides in plants is an adaptation to high salt environments, which may have been conserved during plant evolution from marine green algae. Our results address a practical biological concept; additionally, we suggest future strategies that may be beneficial when engineering salt-resistant crops. PMID:21552557

  12. Bird colonies cause seagrass enrichment in a subtropical estuary: Observational and experimental evidence

    NASA Astrophysics Data System (ADS)

    Powell, George V. N.; Fourqurean, James W.; Kenworthy, W. Judson; Zieman, Joseph C.

    1991-06-01

    Colonies/roosts of piscivorous birds in Florida Bay, a subtropical estuary, concentrate nutrients by feeding away from their colonies/roosts and returning with food for young and to defaecate. Seagrass beds surrounding the colony islands were markedly different from those around similar islands that did not contain colonies. Seagrass standing crop was enhanced up to 200 m from bird colony islands compared with islands without colonies. The species of seagrass were also different at colonies, where Halodule wrightii and Ruppia maritima predominated in zones close to the colony islands. Around islands without colonies, only Thalassia testudinum was present. Experimental bird perches placed to stimulate concentrated bird presence produced changes in adjacent seagrass meadows that were similar to differences between islands with colonies and those without. Over 5 years, seagrass standing crop increased around the experimental perches, and species dominance shifted from T. testudinum to H. wrightii. No similar changes occurred at control locations. These experimental results indicate that the bird concentrations are responsible for the observed differences in seagrass communities surrounding islands that contain colonies. These enriched areas are significant to the seagrass ecosystem because many seagrasses in Florida Bay appear to be nutrient-limited. Demersal fish and invertebrate density and species richness have been shown to be a function of the seagrass standing crop and species composition, so the changes in seagrasses stimulated by localized bird concentrations have the capacity to alter the entire community structure.

  13. Rising from the Sea: Correlations between Sulfated Polysaccharides and Salinity in Plants

    PubMed Central

    Aquino, Rafael S.; Grativol, Clicia; Mourão, Paulo A. S.

    2011-01-01

    High salinity soils inhibit crop production worldwide and represent a serious agricultural problem. To meet our ever-increasing demand for food, it is essential to understand and engineer salt-resistant crops. In this study, we evaluated the occurrence and function of sulfated polysaccharides in plants. Although ubiquitously present in marine algae, the presence of sulfated polysaccharides among the species tested was restricted to halophytes, suggesting a possible correlation with salt stress or resistance. To test this hypothesis, sulfated polysaccharides from plants artificially and naturally exposed to different salinities were analyzed. Our results revealed that the sulfated polysaccharide concentration, as well as the degree to which these compounds were sulfated in halophytic species, were positively correlated with salinity. We found that sulfated polysaccharides produced by Ruppia maritima Loisel disappeared when the plant was cultivated in the absence of salt. However, subjecting the glycophyte Oryza sativa Linnaeus to salt stress did not induce the biosynthesis of sulfated polysaccharides but increased the concentration of the carboxylated polysaccharides; this finding suggests that negatively charged cell wall polysaccharides might play a role in coping with salt stress. These data suggest that the presence of sulfated polysaccharides in plants is an adaptation to high salt environments, which may have been conserved during plant evolution from marine green algae. Our results address a practical biological concept; additionally, we suggest future strategies that may be beneficial when engineering salt-resistant crops. PMID:21552557

  14. Mesohaline submerged aquatic vegetation survey along the U.S. gulf of Mexico coast, 2000: A stratified random approach

    USGS Publications Warehouse

    Carter, J.; Merino, J.H.; Merino, S.L.

    2009-01-01

    Estimates of submerged aquatic vegetative (SAV) along the U.S. Gulf of Mexico (Gulf) generally focus on seagrasses. In 2000, we attempted a synoptic survey of SAV in the mesohaline (5-20 ppt) zone of estuarine and nearshore areas of the northeastern Gulf. Areas with SAV were identified from existing aerial 1992 photography, and a literature review was used to select those areas that were likely to experience mesohaline conditions during the growing season. In 2000, a drought year, we visited 217 randomly selected SAV beds and collected data on species composition and environmental conditions. In general, sites were either clearly polyhaline (2: 20 ppt) or oligohaline (S 5 ppt), with only five sites measuring between 5 and 20 ppt. Ruppia maritima L. (13-35 ppt, n = 28) was the only species that occurred in mesohaline salinities. Halodule wrightii Asch. occurred in 73% of the beds. The nonindigenous Myriophyllum spicatum L. was present in four locations with salinities below 3 ppt. No nonindigenous macroalgae were identified, and no nonindigenous angiosperms occurred in salinities above 3 ppt. Selecting sample locations based on historical salinity data was not a successful strategy for surveying SAV in mesohaline systems, particularly during a drought year. Our ability to locate SAV beds within 50 m of their aerially located position 8 yr later demonstrates some SAV stability in the highly variable conditions of the study area. ?? 2009 by the Marine Environmental Silences Consortium of Alabama.

  15. Mesohaline submerged aquatic vegetation survey along the U.S. gulf of Mexico coast, 2001 and 2002: A salinity gradient approach

    USGS Publications Warehouse

    Merino, J.H.; Carter, J.; Merino, S.L.

    2009-01-01

    Distribution of marine submerged aquatic vegetation (SAV; i.e., seagrass) in the northern Gulf of Mexico coast has been documented, but there are nonmarine submersed or SAV species occurring in estuarine salinities that have not been extensively reported. We sampled 276 SAV beds along the gulf coast in Florida, Alabama, Mississippi, Louisiana, and Texas in 2001 and 2002 in oligohaline to polyhaline (0 to 36 parts per thousand) waters to determine estuarine SAV species distribution and identify mesohaline SAV communities. A total of 20 SAV and algal species was identified and habitat characteristics such as salinity, water depth, pH, conductivity, turbidity, dissolved oxygen, and sediment composition were collected. Fourteen SAV species occurred two or more times in our samples. The most frequently occurring species was Ruppia maritima L. (n = 148), occurring in over half of SAV beds sampled. Eleocharis sp. (n = 47), characterized with an emergent rather than submerged growth form, was a common genus in the SAV beds sampled. A common marine species was Halodule wrightii Asch. (n = 36). Nonindigenous species Myriophyllum spicatum L. (n = 31) and Hydrilla verticillata (L. f.) Royle (n = 6) were present only in oligohaline water. Analyzing species occurrence and environmental characteristics using canonical correspondence and two-way indicator species analysis, we identify five species assemblages distinguished primarily by salinity and depth. Our survey increases awareness of nonmarine SAV as a natural resource in the gulf, and provides baseline data for future research. ?? 2009 by the Marine Environmental Sciences Consortium of Alabama.

  16. Functional adaptations of the bacterial chaperone trigger factor to extreme environmental temperatures.

    PubMed

    Godin-Roulling, Amandine; Schmidpeter, Philipp A M; Schmid, Franz X; Feller, Georges

    2015-07-01

    Trigger factor (TF) is the first molecular chaperone interacting cotranslationally with virtually all nascent polypeptides synthesized by the ribosome in bacteria. Thermal adaptation of chaperone function was investigated in TFs from the Antarctic psychrophile Pseudoalteromonas haloplanktis, the mesophile Escherichia coli and the hyperthermophile Thermotoga maritima. This series covers nearly all temperatures encountered by bacteria. Although structurally homologous, these TFs display strikingly distinct properties that are related to the bacterial environmental temperature. The hyperthermophilic TF strongly binds model proteins during their folding and protects them from heat-induced misfolding and aggregation. It decreases the folding rate and counteracts the fast folding rate imposed by high temperature. It also functions as a carrier of partially folded proteins for delivery to downstream chaperones ensuring final maturation. By contrast, the psychrophilic TF displays weak chaperone activities, showing that these functions are less important in cold conditions because protein folding, misfolding and aggregation are slowed down at low temperature. It efficiently catalyses prolyl isomerization at low temperature as a result of its increased cellular concentration rather than from an improved activity. Some chaperone properties of the mesophilic TF possibly reflect its function as a cold shock protein in E.?coli. PMID:25389111

  17. Fluorescence in insects

    NASA Astrophysics Data System (ADS)

    Welch, Victoria L.; Van Hooijdonk, Eloise; Intrater, Nurit; Vigneron, Jean-Pol

    2012-10-01

    Fluorescent molecules are much in demand for biosensors, solar cells, LEDs and VCSEL diodes, therefore, considerable efforts have been expended in designing and tailoring fluorescence to specific technical applications. However, naturally occurring fluorescence of diverse types has been reported from a wide array of living organisms: most famously, the jellyfish Aequorea victoria, but also in over 100 species of coral and in the cuticle of scorpions, where it is the rule, rather than the exception. Despite the plethora of known insect species, comparatively few quantitative studies have been made of insect fluorescence. Because of the potential applications of natural fluorescence, studies in this field have relevance to both physics and biology. Therefore, in this paper, we review the literature on insect fluorescence, before documenting its occurrence in the longhorn beetles Sternotomis virescens, Sternotomis variabilis var. semi rufescens, Anoplophora elegans and Stellognatha maculata, the tiger beetles Cicindela maritima and Cicindela germanica and the weevil Pachyrrhynchus gemmatus purpureus. Optical features of insect fluorescence, including emitted wavelength, molecular ageing and naturally occurring combinations of fluorescence with bioluminescence and colour-producing structures are discussed.

  18. Determination of 5-methylcytosine from plant DNA by high-performance liquid chromatography.

    PubMed

    Wagner, I; Capesius, I

    1981-06-26

    The relative amounts of the five nucleosides (deoxycytidine, 5-methyldeoxycytidine, deoxyadenosine, deoxyguanosine and thymidine) in the DNA of nine plant species, one plant satellite DNA, and one animal species were determined by high performance liquid chromatography. The method allows the clean separation of the nucleosides from 10 microgram samples with 15 min. The following values for the proportion of methylated cytosines among all cytosines were obtained: Lobularia maritima 18.5%, Nicotiana tabacum 32.6%, Pisum sativum 23.2%, Rhinanthus minor 29.2%, Sinapsis alba 12.2%, Vicia faba 30.5%, Viscum album 23.2%, Cymbidium pumilum 18.8%, Cymbidium pumilum AT-rich satellite DNA 15.8%, Triticum aestivum 22.4%. DNA of an animal, the gerbil, Meriones unguiculatus, had a methylation percentage of 3.1%. An estimate of the GC content based on the buoyant density of DNA tends to be lower than the actual value, an estimate based on the melting temperature tends to be higher. This supports the finding by other authors that DNA methylation decreases the buoyant density and may increase the melting temperature at high m5C concentration. PMID:7272310

  19. Response of some common annual bedding plants to three species of meloidogyne.

    PubMed

    McSorley, R; Frederick, J J

    1994-12-01

    Twelve ornamental bedding plant cultivars were grown in soil infested with isolates of Meloidogyne incognita race 1, M. javanica, or M. arenaria race 1 in a series of tests in containers in a growth room. Root galling (0-5 scale) and eggs/plant were evaluated 8-10 weeks after soil infestation and seedling transplantation. Snapdragon, Antirrhinum majus cv. First Ladies, was extensively galled and highly susceptible (mean gall rating >/=4.2 and >/=14,500 eggs/plant), and Celosia argentea cv. Century Mix and Coleus blumei cv. Rainbow were susceptible (>1,500 eggs/plant) to all three Meloidogyne isolates. Response of Petunia x hybrida varied with cultivar and nematode isolate. Little or no galling or egg production from any Meloidogyne isolate was observed on Ageratum houstonianum cv. Blue Mink, Lobularia maritima cv. Rosie O'Day, or Tagetes patula cv. Dwarf Primrose. Galling was slight (mean rating 4.0 and >/=7,900 eggs/plant) by M. javanica and M. arenaria but was nearly free of galling from M. incognita. Zinna elegans cv. Scarlet was nearly free of galling from M. incognita and M. arenaria but was susceptible (mean gall rating = 2.9; 3,400 eggs/plant) to M. javanica. PMID:19279963

  20. Response of Some Common Annual Bedding Plants to Three Species of Meloidogyne

    PubMed Central

    McSorley, R.; Frederick, J. J.

    1994-01-01

    Twelve ornamental bedding plant cultivars were grown in soil infested with isolates of Meloidogyne incognita race 1, M. javanica, or M. arenaria race 1 in a series of tests in containers in a growth room. Root galling (0-5 scale) and eggs/plant were evaluated 8-10 weeks after soil infestation and seedling transplantation. Snapdragon, Antirrhinum majus cv. First Ladies, was extensively galled and highly susceptible (mean gall rating ?4.2 and ?14,500 eggs/plant), and Celosia argentea cv. Century Mix and Coleus blumei cv. Rainbow were susceptible (>1,500 eggs/plant) to all three Meloidogyne isolates. Response of Petunia x hybrida varied with cultivar and nematode isolate. Little or no galling or egg production from any Meloidogyne isolate was observed on Ageratum houstonianum cv. Blue Mink, Lobularia maritima cv. Rosie O'Day, or Tagetes patula cv. Dwarf Primrose. Galling was slight (mean rating ?2.0) but varied with nematode species on Dianthus chinensis cv. Baby Doll Mix, Salvia splendens cv. Bonfire, and Vinca rosea cv. Little Bright Eye. Verbena × hybrida cv. Florist was heavily infected (gall rating >4.0 and ?7,900 eggs/plant) by M. javanica and M. arenaria but was nearly free of galling from M. incognita. Zinna elegans cv. Scarlet was nearly free of galling from M. incognita and M. arenaria but was susceptible (mean gall rating = 2.9; 3,400 eggs/plant) to M. javanica. PMID:19279963

  1. Anaerobic High-Throughput Cultivation Method for Isolation of Thermophiles Using Biomass-Derived Substrates

    SciTech Connect

    Hamilton-Brehm, Scott [ORNL; Vishnivetskaya, Tatiana A [ORNL; Allman, Steve L [ORNL; Mielenz, Jonathan R [ORNL; Elkins, James G [ORNL

    2012-01-01

    Flow cytometry (FCM) techniques have been developed for sorting mesophilic organisms, but the difficulty increases if the target microbes are thermophilic anaerobes. We demonstrate a reliable, high-throughput method of screening thermophilic anaerobic organisms using FCM and 96-well plates for growth on biomass-relevant substrates. The method was tested using the cellulolytic thermophiles Clostridium ther- mocellum (Topt = 55 C), Caldicellulosiruptor obsidiansis (Topt = 78 C) and the fermentative hyperthermo- philes, Pyrococcus furiosus (Topt = 100 C) and Thermotoga maritima (Topt = 80 C). Multi-well plates were incubated at various temperatures for approximately 72 120 h and then tested for growth. Positive growth resulting from single cells sorted into individual wells containing an anaerobic medium was verified by OD600. Depending on the growth substrate, up to 80 % of the wells contained viable cultures, which could be transferred to fresh media. This method was used to isolate thermophilic microbes from Rabbit Creek, Yellowstone National Park (YNP), Wyoming. Substrates for enrichment cultures including crystalline cellulose (Avicel), xylan (from Birchwood), pretreated switchgrass and Populus were used to cultivate organisms that may be of interest to lignocellulosic biofuel production.

  2. Structures of the N-terminal modules imply large domain motions during catalysis by methionine synthase.

    PubMed

    Evans, John C; Huddler, Donald P; Hilgers, Mark T; Romanchuk, Gail; Matthews, Rowena G; Ludwig, Martha L

    2004-03-16

    B(12)-dependent methionine synthase (MetH) is a large modular enzyme that utilizes the cobalamin cofactor as a methyl donor or acceptor in three separate reactions. Each methyl transfer occurs at a different substrate-binding domain and requires a different arrangement of modules. In the catalytic cycle, the cobalamin-binding domain carries methylcobalamin to the homocysteine (Hcy) domain to form methionine and returns cob(I)alamin to the folate (Fol) domain for remethylation by methyltetrahydrofolate (CH(3)-H(4)folate). Here, we describe crystal structures of a fragment of MetH from Thermotoga maritima comprising the domains that bind Hcy and CH(3)-H(4)folate. These substrate-binding domains are (beta alpha)(8) barrels packed tightly against one another with their barrel axes perpendicular. The properties of the domain interface suggest that the two barrels remain associated during catalysis. The Hcy and CH(3)-H(4)folate substrates are bound at the C termini of their respective barrels in orientations that position them for reaction with cobalamin, but the two active sites are separated by approximately 50 A. To complete the catalytic cycle, the cobalamin-binding domain must travel back and forth between these distant active sites. PMID:14752199

  3. Structures of the N-terminal modules imply large domain motions during catalysis by methionine synthase

    PubMed Central

    Evans, John C.; Huddler, Donald P.; Hilgers, Mark T.; Romanchuk, Gail; Matthews, Rowena G.; Ludwig, Martha L.

    2004-01-01

    B12-dependent methionine synthase (MetH) is a large modular enzyme that utilizes the cobalamin cofactor as a methyl donor or acceptor in three separate reactions. Each methyl transfer occurs at a different substrate-binding domain and requires a different arrangement of modules. In the catalytic cycle, the cobalamin-binding domain carries methylcobalamin to the homocysteine (Hcy) domain to form methionine and returns cob(I)alamin to the folate (Fol) domain for remethylation by methyltetrahydrofolate (CH3-H4folate). Here, we describe crystal structures of a fragment of MetH from Thermotoga maritima comprising the domains that bind Hcy and CH3-H4folate. These substrate-binding domains are (??)8 barrels packed tightly against one another with their barrel axes perpendicular. The properties of the domain interface suggest that the two barrels remain associated during catalysis. The Hcy and CH3-H4folate substrates are bound at the C termini of their respective barrels in orientations that position them for reaction with cobalamin, but the two active sites are separated by ?50 Å. To complete the catalytic cycle, the cobalamin-binding domain must travel back and forth between these distant active sites. PMID:14752199

  4. Supporting adaptation decisions to address climate related impacts and hazards in the Caribbean (the CARIWIG project)

    NASA Astrophysics Data System (ADS)

    Burton, Aidan

    2015-04-01

    Managers and policy makers from regional and national institutions in the Caribbean require knowledge of the likely impacts and hazards arising from the present and future climate that are specific to their responsibility and geographical range, and relevant to their planning time-horizons. Knowledge, experience and the political support to develop appropriate adaptation strategies are also required. However, the climate information available for the region is of limited use as: observational records are intermittent and typically of short duration; climate model projections of the weather suffer from scale and bias issues; and statistical downscaling to provide locally relevant unbiased climate change information remains sporadic. Tropical cyclone activity is a considerable sporadic hazard in the region and yet related weather information is limited to historic events. Further, there is a lack of guidance for managers and policy makers operating with very limited resources to utilize such information within their remit. The CARIWIG project (June 2012 - May 2015) will be presented, reflecting on stakeholder impact, best practice and lessons learned. This project seeks to address the climate service needs of the Caribbean region through a combination of capacity building and improved provision of climate information services. An initial workshop with regional-scale stakeholders initiated a dialogue to develop a realistic shared vision of the needed information services which could be provided by the project. Capacity building is then achieved on a number of levels: knowledge and expertise sharing between project partners; raising understanding and knowledge of resources that support national and regional institutions' adaptation decisions; developing case studies in key sectors to test and demonstrate the information services; training for stakeholder technical staff in the use of the provided services; the development of a support network within and out-of-region between stakeholders and research institutes concerned with environmental hazards and impacts. The project seeks to provide locally relevant present and future-scenario climatic data through an intuitive web service. Present climate summary data, based on meteorological station observations, is provided for locations across the region. Relatively high resolution (25km) PRECIS regional climate projections (1961-2100) are available for the region conditioned with the HadCM3Q0 and ECHAM5 GCM using the A1B SRES emissions scenario. Bias corrected control and future climate scenarios (for 30-year time slices centred on the 2020s, 2050s and 2080s) comprising timeseries of daily meteorological variables are then simulated using the EARWIG and UKCP09 statistical downscaling approach adapted for the Caribbean. A novel modelling tool provides a basis for testing vulnerability to tailored scenarios of tropical cyclone hazard. The CARIWIG project seeks to provide a lasting impact through an emphasis on building regional stakeholder capacity and through technological design that allows the flexibility to include additional meteorological records and new climate projections as they become available.

  5. Masterplan to safeguard Venice and to restore the lagoon and conterminous areas

    NASA Astrophysics Data System (ADS)

    Bini, Claudio; Gallo, Alba; Nadimi-Goki, Mandana; Wahsha, Mohammad

    2015-04-01

    Venice and its lagoon constitute a complex system, well known all over the world for the peculiarity of the town and for the fragility of the lagoon ecosystem with its delicate equilibrium. The whole system has been, and is currently, affected by human activities (industry, agriculture, settlements, tourism) that impact severely the ecosystem. Discharge from the agricultural drainage basin affects particularly the area North of the city of Venice; the central and southern areas, instead, receive important pollutant inputs from the industrial zone of Porto Marghera since the early'50s. Additional sources of pollution are domestic sewage and waste disposal from the urban area, that is visited by more than 10M people every year. As a consequence of the increasing land contamination, significant amounts of contaminants (both organic and inorganic) are accumulated in soils of the borderline, in water and in lagoon sediments, which constitute a potential source of secondary pollution. Results of surveys carried out in recent years in the whole area show that contaminants concentration increased from the beginning of the industrial activities until the '90s, when Porto Marghera declined. Most of contaminants have concentrations above the background levels. The highest metal levels were found in an area between Porto Marghera and the city of Venice, where both industrial and urban sewage are discharged, provoking environmental and human health hazard. In order to safeguard the city of Venice, and to restore its lagoon and conterminous areas, a Master Plan of intervention has been developed since the early 2000s. The land currently interested by environmental analysis and/or restoration covers approximately 1350ha; 78% of these (1100ha) proved variously contaminated, with 85% of sites overcoming the National Reference Values. Contamination, besides being diffused, is quite complex, involving the co-existence of several contaminant families (PAH, PCB, dioxin, heavy metals). PAH and metals, in particular, present wide diffusion, both horizontal and vertical (until 5 m below the sea level), with As, Zn, Cd and Hg being the elements more represented in all the soil strata considered. The lagoon sediments inside industrial channels is higher than the other parts of the lagoon; major contaminants are metals (As, Cd, Hg, Pb) and organic micro-pollutants (PCB, PAH); ammonia and phosphate too are present with conspicuous concentrations, contributing to lagoon eutrophication. Groundwater contamination is diffused and complex, with As prevailing over Pb and Cr(VI). The primary objective of the Master Plan was to reduce/eliminate the risk associated to the contamination sources of past activities, and the consequent environmental and human health hazard. Restoration is still in progress, and concerns different intervention strategies: • Channel overbank containment to prevent contaminant migration to water; • Excavation, physical removal and re-distribution of channel sediments (A and B classes); • Landfilling of heavily contaminated sediments (C class); • Soil containment to impede contact with people and the environment; • Restoration of contaminated agricultural land with phytoremediation techniques. Concerning in particular the last item, restoration has been carried out with native or exotic vegetation (e.g. Fragmites australis, Juncus lacustris, Pterix vittata, Spartina maritima), or cultivated plants (e.g. Heliantus annuus, Zea mays, Brassica napus), with contrasting results. The exotic fern (Pterix vittata) proved highly effective to accumulate As, consistently with data from literature; Spartina maritima proved more effective than Fragmites australis to uptake metals, while cultivated plants could not survive to high heavy metal concentrations. At some sites, soil has been stored, selected and finally (the most contaminated part) delivered to landfill, while groundwater was remediated by bioremediation techniques.

  6. Assembly states of FliM and FliG within the flagellar switch complex.

    PubMed

    Sircar, Ria; Borbat, Peter P; Lynch, Michael J; Bhatnagar, Jaya; Beyersdorf, Matthew S; Halkides, Christopher J; Freed, Jack H; Crane, Brian R

    2015-02-27

    At the base of the bacterial flagella, a cytoplasmic rotor (the C-ring) generates torque and reverses rotation sense in response to stimuli. The bulk of the C-ring forms from many copies of the proteins FliG, FliM, and FliN, which together constitute the switch complex. To help resolve outstanding issues regarding C-ring architecture, we have investigated interactions between FliM and FliG from Thermotoga maritima with X-ray crystallography and pulsed dipolar ESR spectroscopy (PDS). A new crystal structure of an 11-unit FliG:FliM complex produces a large arc with a curvature consistent with the dimensions of the C-ring. Previously determined structures along with this new structure provided a basis to test switch complex assembly models. PDS combined with mutational studies and targeted cross-linking reveal that FliM and FliG interact through their middle domains to form both parallel and antiparallel arrangements in solution. Residue substitutions at predicted interfaces disrupt higher-order complexes that are primarily mediated by contacts between the C-terminal domain of FliG and the middle domain of a neighboring FliG molecule. Spin separations among multi-labeled components fit a self-consistent model that agree well with electron microscopy images of the C-ring. An activated form of the response regulator CheY destabilizes the parallel arrangement of FliM molecules to perturb FliG alignment in a process that may reflect the onset of rotation switching. These data suggest a model of C-ring assembly in which intermolecular contacts among FliG domains provide a template for FliM assembly and cooperative transitions. PMID:25536293

  7. Impacts of summer ozone exposure on the growth and overwintering of UK upland vegetation

    NASA Astrophysics Data System (ADS)

    Hayes, Felicity; Mills, Gina; Williams, Philip; Harmens, Harry; Büker, Patrick

    The effects of ozone exposure on species of an upland grassland were assessed. Thirty-three species from Snowdonia, North Wales, UK, were exposed for 10 weeks to a weekly episodic ozone regime in solardomes representing predicted future concentrations. Two solardomes were used as controls, with ozone added to charcoal-filtered air to give a continuous ozone concentration of 30 ppb (O 3(30)). A weekly episodic ozone regime was applied to two other solardomes, with concentrations rising for 8 h per day to 80 ppb on day 1, 100 ppb on days 2 and 3, and 80 ppb on day 4; ozone concentrations remained at 30 ppb at all other times (O 3(30+peaks)). The control and background ozone concentrations of 30 ppb were maintained throughout the night as well as during the daytime. During exposure to the episodic ozone regime, some species were sensitive to ozone and showed ozone-specific leaf injury symptoms (e.g . Carex echinata) and/or premature senescence (e.g. Festuca rubra) and/or changes in above-ground biomass (e.g. Armeria maritima), whereas other species (e.g Holcus lanatus and Carex demissa) showed no effects. Some species, although showing no effects during the 10-week ozone exposure, showed carry-over effects on biomass the following spring, after a winter period of ambient ozone exposure (e.g. Galium saxatile, Nardus stricta and Saxifraga stellaris). The carry-over effects shown in this study indicate the potential ecological impact of ozone on semi-natural vegetation species and indicate the importance of longer-term studies on the effects of ozone on plants.

  8. Ethnopharmacological survey of wild medicinal plants in Showbak, Jordan.

    PubMed

    Al-Qura'n, S

    2009-05-01

    Two main research questions are framing this investigation: (1) the main taxa of the medicinal importance value altered the Showbak forest stand and species composition? (2) The most safe species and what are the toxic ones (unsafe). These two research questions are the vital ones to draw a clear image about the wild medicinal plants of this investigated area of Showbak region in Jordan. 79 wild medicinal plant species were investigated in this study which are used in traditional medication for the treatment of various diseases. Most of the locals interviewed dealt with well-known safe medicinal plants such as Aaronsohnia factorovskyi Warb. et Eig., Achillea santolina L., Adiantum capillus-veneris L., Artemisia herba-alba L., Ceratonia siliqua L., Clematis recta L., Herniaria hirsuta L., Malva neglecta Wallr., Rosmarinus officinalis L., Ruta chalepensis L., Salvia triloba L., Sarcopoterium spinosa (L.) Spach., Thymbra capitata (L.) Hof, and Urginea maritima Barker. Many of the wild medicinal plants investigated were toxic and needed to be practiced by practitioners and herbalists rather than the local healers. These plants include Calotropis procera Willd R.Br., Citrullus colocynthis (L.) Sch., Datura stramonium L., Digitalis purpurea L., Ecballium elaterium (L.) A.Rich., Euphorbia helioscopia L., Euphorbia tinctoria Boiss., Glaucium corniculatum (L.) Curt., Hyoscyamus aureus L., Mandragora officinarum L., Nerium oleander L., Ricinus communis L., Solanum nigrum L., Withania somnifera (L.) Dunel. The conservation of medicinal plants and natural resources is becoming increasingly important, so this research is trying to collect information from local population concerning the use of medicinal plants in Showbak; identify the most important specie; determine the relative importance value of the species and calculate the informant consensus factor (ICF) for the medicinal plants. Obtaining results is relied on the interviewee's personal information and the medicinal use of specific plants. PMID:19429338

  9. Exploring codon context bias for synthetic gene design of a thermostable invertase in Escherichia coli.

    PubMed

    Pek, Han Bin; Klement, Maximilian; Ang, Kok Siong; Chung, Bevan Kai-Sheng; Ow, Dave Siak-Wei; Lee, Dong-Yup

    2015-01-01

    Various isoforms of invertases from prokaryotes, fungi, and higher plants has been expressed in Escherichia coli, and codon optimisation is a widely-adopted strategy for improvement of heterologous enzyme expression. Successful synthetic gene design for recombinant protein expression can be done by matching its translational elongation rate against heterologous host organisms via codon optimization. Amongst the various design parameters considered for the gene synthesis, codon context bias has been relatively overlooked compared to individual codon usage which is commonly adopted in most of codon optimization tools. In addition, matching the rates of transcription and translation based on secondary structure may lead to enhanced protein folding. In this study, we evaluated codon context fitness as design criterion for improving the expression of thermostable invertase from Thermotoga maritima in Escherichia coli and explored the relevance of secondary structure regions for folding and expression. We designed three coding sequences by using (1) a commercial vendor optimized gene algorithm, (2) codon context for the whole gene, and (3) codon context based on the secondary structure regions. Then, the codon optimized sequences were transformed and expressed in E. coli. From the resultant enzyme activities and protein yield data, codon context fitness proved to have the highest activity as compared to the wild-type control and other criteria while secondary structure-based strategy is comparable to the control. Codon context bias was shown to be a relevant parameter for enhancing enzyme production in Escherichia coli by codon optimization. Thus, we can effectively design synthetic genes within heterologous host organisms using this criterion. PMID:26047917

  10. Chimeric thermostable DNA polymerases with reverse transcriptase and attenuated 3'-5' exonuclease activity.

    PubMed

    Schönbrunner, Nancy J; Fiss, Ellen H; Budker, Olga; Stoffel, Susanne; Sigua, Christopher L; Gelfand, David H; Myers, Thomas W

    2006-10-24

    The synthesis of accurate, full-length cDNA from low-abundance RNA and the subsequent PCR amplification under conditions which provide amplicon that contains minimal mutations remain a difficult molecular biological process. Many of the challenges associated with performing sensitive, long RT/PCR have been alleviated by using a mixture of DNA polymerases. These mixtures have typically contained a DNA polymerase devoid of 3'-5' exonuclease, or "proofreading", activity blended with a small amount of an Archaea DNA polymerase possessing 3'-5' exonuclease activity, since reverse transcriptases lack 3'-5' exonuclease activity and generally have low fidelity. To create a DNA polymerase with efficient reverse transcriptase and 3'-5' exonuclease activity, a family of mutant DNA polymerases with a range of attenuated 3'-5' exonuclease activities was constructed from a chimeric DNA polymerase derived from Thermus species Z05 and Thermotoga maritima DNA polymerases. These "designer" DNA polymerases were fashioned using structure-based tools to identify amino acid residues involved in the substrate-binding site of the exonuclease domain of a thermostable DNA polymerase. Mutation of some of these residues resulted in proteins in which DNA polymerase activity was unaffected, while proofreading activity ranged from 60% of the wild-type level to undetectable levels. Kinetic characterization of the exonuclease activity indicated that the mutations affected catalysis much more than binding. On the basis of their specificity constants (kcat/KM), the mutant enzymes have a 5-15-fold stronger preference for a double-stranded mismatched substrate over a single-stranded substrate than the wild-type DNA polymerase, a desirable attribute for RT/PCR. The utility of these enzymes was evaluated in a RT/PCR assay to generate a 1.7 kb amplicon from HIV-1 RNA. PMID:17042497

  11. Vegetation change on a northeast tidal marsh: Interaction of sea-level rise and marsh accretion

    SciTech Connect

    Warren, R.S.; Niering, W.A. (Connecticut College, New London (United States))

    1993-01-01

    Increasing rates of relative sea-level rise (RSL) have been linked to coastal wetland losses along the Gulf of Mexico and elsewhere. Rapidly rising RSL may be affecting New England tidal marshes. Studies of the Wequetequock-Pawcatuck tidal marshes over four decades have documented dramatic changes in vegetation apparently related primarily to differential rates of marsh accretion and sea-level rise though sediment supply and anthropogenic modifications of the system may also be involved. When initially studied in 1947-1948 the high marsh supported a Juncus gerardi-Spartina patens belting pattern typical of many New England salt marshes. On most of the marsh complex the former Juncus belt has now been replaced by forbs, primarily Triglochin maritima, while the former S. patens high marsh is now a complex of vegetation types-stunted Spartina alterniflora, Distichlis spicata, forbs, and relic stands of S. patens. The mean surface elevation of areas where the vegetation has changed is significantly lower than that of areas still supporting the earlier pattern (4.6 vs. 13.9 cm above mean tide level). The differences in surface elevation reflect differences in accretion of marsh peat. Stable areas have been accreting at the rate of local sea-level rise, 2.0-2.5 mm/yr at least since 1938; changed areas have accreted at about one half that rate. Lower surface elevations result in greater frequency and duration of tidal flooding, and thus in increased peat saturation, salinity, and sulfide concentrations, and in decreased redox potential, as directly measured over the growing season at both changed and stable sites. These edaphic changes may have combined to favor establishment of a wetter, more open vegetation type. Similar changes have been observed on other Long Island Sound marshes and may be a model for the potential effects of sea-level rise on New England tidal salt marshes. 39 refs., 4 figs., 1 tab.

  12. Laboratory Directed Research & Development program. Annual report to the Department of Energy

    SciTech Connect

    Ogeka, G.J.; Romano, A.J.

    1995-12-01

    This report briefly discusses the following projects coordinated at Brookhaven National Laboratory: investigation of the utility of max-entropy methods for the analysis of powder diffraction data; analysis of structures and interactions of nucleic acids and proteins by small angle x-ray diffraction; relaxographic MRI and functional MRI; very low temperature infra-red laser absorption as a potential analytical tool; state-resolved measurements of H{sub 2} photodesorption: development of laser probes of H{sub 2} for in-situ accelerator measurements; Siberian snake prototype development for RHIC; synthesis and characterization of novel microporous solids; ozone depletion, chemistry and physics of stratospheric aerosols; understanding the molecular basis for the synthesis of plant fatty acids possessing unusual double bond positions; structure determination of outer surface proteins of the Lyme disease spirochete; low mass, low-cost multi-wire proportional chambers for muon systems of collider experiments; theory of self-organized criticality; development of the PCR-SSCP technique for the detection, at the single cell level, of specific genetic changes; feasibility of SPECT in imaging of F-18 FDG accumulation in tumors; visible free electron laser oscillator experiment; study of possible 2 + 2 TeV muon-muon collider; ultraviolet FEL R & D; precision machining using hard x-rays; new directions in in-vivo enzyme mapping: catechol-O-methyltransferase; proposal to develop a high rate muon polarimeter; development of intense, tunable 20-femtosecond laser systems; use of extreme thermophilic bacterium thermatoga maritima as a source of ribosomal components and translation factors for structural studies; and biochemical and structural studies of Chaperon proteins from thermophilic bacteria and other experiments.

  13. Evidence for preferential depths of metal retention in roots of salt marsh plants.

    PubMed

    Caetano, Miguel; Vale, Carlos; Cesário, Rute; Fonseca, Nuno

    2008-02-15

    Depth variation (2-cm resolution) of Fe, Mn, Zn, Cr, Ni, Cu, As and Cd concentrations were determined in belowground biomass of Spartina maritima and Sarcocornia fruticosa and in sediments between roots from two marshes in Tagus (Rosário) and Guadiana (Castro Marim) estuaries in Portugal with different anthropogenic pressures. Levels of metals were also determined in aboveground plant parts. Metal concentrations in belowground material were 2-4 orders of magnitude greater than levels in aboveground plant parts providing evidence of weak upward translocation. Although both studied species showed poor extraction of Cr and Ni from sediments, S. fruticosa exhibited a large capability to remove Zn, Cu, As and Cd from contaminated sediments and stabilised them in belowground biomass. Accumulated metals showed a sub-surface concentration maximum or increase to basal roots. To evaluate whether these preferential layers of accumulation resulted from availability in sediments or controlled by plant activity, Enrichment Factors (EF=[Me](root)/[Metal](sediment)) were calculated for each sediment layer. Maximum values in Rosário plant species (Zn=9.3, Cu=18, As=20, Cd=46) exceeded those obtained in Castro Marim (Zn=1.3, Cu=4.3, As=6.1, Cd=18). Moreover, EFs varied with the depth indicating the presence of preferential layers of metal accumulation in roots of both plants, but depth zonation was not the same as in the sediments. These results suggested that levels in belowground biomass either integrated in time changes that occurred in solid sediments and pore water, or metal uptake by roots was not proportional to levels in sediments. The same sequence of metals transferred from sediment to belowground biomass for the two plants was obtained for the two marshes (Cd > As > Cu, Zn), although metals differed from mining ore to industrial/urban sources. PMID:18036637

  14. Analysis of DNA polymorphisms in sugar beet (Beta vulgaris L.) and development of an SNP-based map of expressed genes.

    PubMed

    Schneider, Katharina; Kulosa, Dagmar; Soerensen, Thomas Rosleff; Möhring, Silke; Heine, Martin; Durstewitz, Gregor; Polley, Andreas; Weber, Eberhard; Jamsari; Lein, Jens; Hohmann, Uwe; Tahiro, Emma; Weisshaar, Bernd; Schulz, Britta; Koch, Georg; Jung, Christian; Ganal, Martin

    2007-09-01

    A panel of 13 sugar beet lines and one genotype each of the Beta vulgaris cultivars red beet and Swiss chard, and B. vulgaris ssp. maritima were used to identify polymorphisms in alignments of genomic DNA sequences derived from 315 EST- and 43 non-coding RFLP-derived loci. In sugar beet lines, loci of expressed genes showed an average SNP frequency of 1/72 bp, 1 in 58 bp in non-coding sequences, increasing to 1/47 bp upon the addition of the remaining genotypes. Within analysed DNA fragments, alleles at different SNP positions displayed linkage disequilibrium indicative of haplotype structures. On average 2.7 haplotypes were found in sugar beet lines, and haplotype conservation in expressed genes appeared to exceed 500 bp in length. Seven different genotyping techniques including SNP detection by MALDI-TOF mass spectrometry, pyrosequencing and fluorescence scanning of labelled nucleotides were employed to perform 712 segregation analyses for 538 markers in three F(2) populations. Functions were predicted for 492 mapped sequences. Genetic maps comprised 305 loci covering 599.8 cM in population K1, 241 loci distributed over 636.6 cM in population D2, and 166 loci over 507.1 cM in population K2, respectively. Based on 156 markers common to more than one population an integrated map was constructed with 524 loci covering 664.3 cM. For 377 loci the genome positions of the most similar sequences from A. thaliana were identified, but little evidence for previously presented ancestral genome structures was found. PMID:17622508

  15. Mobile dunes and eroding salt marshes

    NASA Astrophysics Data System (ADS)

    Neuhaus, R.

    1994-06-01

    The paper deals with general outlines of salt marsh and dune vegetation in the Ellenbogen and Listland area on Sylt (Schleswig-Holstein, FRG). The composition of current salt marsh vegetation is considered to be mainly the result of a long-lasting process of tidal inundation, grazing, and a permanent influence of groundwater seepage from the surrounding dunes. The lower salt marsh communities have shown constancy for 67 years, due to the effect of heavy grazing. The mid-upper salt marsh communities demonstrated a succession from a Puccinellia maritima-dominated community of the lower marsh to a Juncus gerardii-dominated community of the mid-upper salt marsh, which may be due to the transport of sand — over a short time — on the surface of the marsh. The area covered by plant communities of annuals below Mean High Water (MHW) seemed to diminish. Salt marsh soils, especially of the mid-upper marsh, indicate sandy layers resulting from sand drift of the dunes. Dry and wet successional series of the dunes in the Listland/Ellenbogen area both show grassy stages shifting to dwarf shrubs as final stages. White primary dunes can only be found on the accreting shoreline of the Ellenbogen, which is also grazed by sheep; vegetation cover therefore remains dominated by grasses, mosses and lichens. Three mobile dunes (as the most prominent features of this landscape) have been left unaffected by seeding and planting by local authorities. Grazing is considered to be an inadequate tool in nature conservation as long as natural processes are to prevail in the landscape as major determinants.

  16. Distribution and Segregation of Two Sympatric Brevoortia Species (Teleostei: Clupeidae)

    NASA Astrophysics Data System (ADS)

    Castillo-Rivera, M.; Kobelkowsky, A.

    2000-05-01

    The authors described and analysed the temporal and spatial distribution and segregation patterns of Brevoortia patronus and B. gunteri, in a coastal lagoon of Veracruz, Mexico. A total of 394 individuals of B. gunteri (mean SL of 61·7 mm) and 378 of B. patronus (mean SL of 128·0) were collected, in 189 monthly and 48 diel (24-h cycles) samples. Both species showed two catchability peaks—one during March-May (dry season) and the second in July-October (rainy season)—and these peaks were related with the two primary production pulses in the system. These patterns were slightly different for each species, the first peak being more important for B. gunteri (68·6%), and the second for B. patronus (78·2%). Brevoortia patronus number was correlated with rainfall ( P<0·01), and the relative abundance of both species was correlated with salinity ( P<0·05). In 24-h cycle analysis, the two species were more abundant around midday (10:00 to 14:00 h), with few individuals captured during the night, and this behaviour was probably related to light intensity and their trophic activities. Moreover, no diel separation between species was observed. Spatially, B. gunteri was principally captured (67·4%) in sites with higher salinities and with no submerged vegetation, and B. patronus was mainly captured (70·9%) in sites with low salinity and with dense beds of Ruppia maritima. Thus, the authors consider salinity as an important factor in the seasonal and spatial segregation of Brevoortia species, with B. gunteri common in periods and zones with higher salinity and B. patronus in periods and areas of low salinity. The results presented here suggest that these segregation patterns permit resource partitioning between these species and facilitate their local co-existence.

  17. Crystal complexes of a predicted S-adenosylmethionine-dependent methyltransferase reveal a typical AdoMet binding domain and a substrate recognition domain

    SciTech Connect

    Miller, D.J.; Ouellette, N.; Evodokimova, E.; Savchenko, A.; Edwards, A.; Anderson, W.F. (Toronto); (NWU)

    2010-03-08

    S-adenosyl-L-methionine-dependent methyltransferases (MTs) are abundant, and highly conserved across phylogeny. These enzymes use the cofactor AdoMet to methylate a wide variety of molecular targets, thereby modulating important cellular and metabolic activities. Thermotoga maritima protein 0872 (TM0872) belongs to a large sequence family of predicted MTs, ranging phylogenetically from relatively simple bacteria to humans. The genes for many of the bacterial homologs are located within operons involved in cell wall synthesis and cell division. Despite preliminary biochemical studies in E. coli and B. subtilis, the substrate specificity of this group of more than 150 proteins is unknown. As part of the Midwest Center for Structural Genomics initiative (www.mcsg.anl.gov), we have determined the structure of TM0872 in complexes with AdoMet and with S-adenosyl-L-homocysteine (AdoHcy). As predicted, TM0872 has a typical MT domain, and binds endogenous AdoMet, or co-crystallized AdoHcy, in a manner consistent with other known MT structures. In addition, TM0872 has a second domain that is novel among MTs in both its location in the sequence and its structure. The second domain likely acts in substrate recognition and binding, and there is a potential substrate-binding cleft spanning the two domains. This long and narrow cleft is lined with positively charged residues which are located opposite the S{sup +}-CH{sub 3} bond, suggesting that a negatively charged molecule might be targeted for catalysis. However, AdoMet and AdoHcy are both buried, and access to the methyl group would presumably require structural rearrangement. These TM0872 crystal structures offer the first structural glimpses at this phylogenetically conserved sequence family.

  18. Ancestral Chromosomal Blocks Are Triplicated in Brassiceae Species with Varying Chromosome Number and Genome Size1

    PubMed Central

    Lysak, Martin A.; Cheung, Kwok; Kitschke, Michaela; Bureš, Petr

    2007-01-01

    The paleopolyploid character of genomes of the economically important genus Brassica and closely related species (tribe Brassiceae) is still fairly controversial. Here, we report on the comparative painting analysis of block F of the crucifer Ancestral Karyotype (AK; n = 8), consisting of 24 conserved genomic blocks, in 10 species traditionally treated as members of the tribe Brassiceae. Three homeologous copies of block F were identified per haploid chromosome complement in Brassiceae species with 2n = 14, 18, 20, 32, and 36. In high-polyploid (n ? 30) species Crambe maritima (2n = 60), Crambe cordifolia (2n = 120), and Vella pseudocytisus (2n = 68), six, 12, and six copies of the analyzed block have been revealed, respectively. Homeologous regions resembled the ancestral structure of block F within the AK or were altered by inversions and/or translocations. In two species of the subtribe Zillineae, two of the three homeologous regions were combined via a reciprocal translocation onto one chromosome. Altogether, these findings provide compelling evidence of an ancient hexaploidization event and corresponding whole-genome triplication shared by the tribe Brassiceae. No direct relationship between chromosome number and genome size variation (1.2–2.5 pg/2C) has been found in Brassiceae species with 2n = 14 to 36. Only two homeologous copies of block F suggest a whole-genome duplication but not the triplication event in Orychophragmus violaceus (2n = 24), and confirm a phylogenetic position of this species outside the tribe Brassiceae. Chromosome duplication detected in Orychophragmus as well as chromosome rearrangements shared by Zillineae species demonstrate the usefulness of comparative cytogenetics for elucidation of phylogenetic relationships. PMID:17720758

  19. Identification of an intermediate methyl carrier in the radical S-adenosylmethionine methylthiotransferases RimO and MiaB.

    PubMed

    Landgraf, Bradley J; Arcinas, Arthur J; Lee, Kyung-Hoon; Booker, Squire J

    2013-10-16

    RimO and MiaB are radical S-adenosylmethionine (SAM) enzymes that catalyze the attachment of methylthio (-SCH3) groups to macromolecular substrates. RimO attaches a methylthio group at C3 of aspartate 89 of protein S12, a component of the 30S subunit of the bacterial ribosome. MiaB attaches a methylthio group at C2 of N(6)-(isopentenyl)adenosine, found at nucleotide 37 in several prokaryotic tRNAs. These two enzymes are prototypical members of a subclass of radical SAM enzymes called methylthiotransferases (MTTases). It had been assumed that the sequence of steps in MTTase reactions involves initial sulfur insertion into the organic substrate followed by capping of the inserted sulfur atom with a SAM-derived methyl group. In this work, however, we show that both RimO and MiaB from Thermotoga maritima catalyze methyl transfer from SAM to an acid/base labile acceptor on the protein in the absence of their respective macromolecular substrates. Consistent with the assignment of the acceptor as an iron-sulfur cluster, denaturation of the SAM-treated protein with acid results in production of methanethiol. When RimO or MiaB is first incubated with SAM in the absence of substrate and reductant and then incubated with excess S-adenosyl-l-[methyl-d3]methionine in the presence of substrate and reductant, production of the unlabeled product precedes production of the deuterated product, showing that the methylated species is chemically and kinetically competent to be an intermediate. PMID:23991893

  20. Evolution of the pair rule gene network: Insights from a centipede.

    PubMed

    Green, Jack; Akam, Michael

    2013-10-01

    Comparative studies have examined the expression and function of homologues of the Drosophila melanogaster pair rule and segment polarity genes in a range of arthropods. The segment polarity gene homologues have a conserved role in the specification of the parasegment boundary, but the degree of conservation of the upstream patterning genes has proved more variable. Using genomic resources we identify a complete set of pair rule gene homologues from the centipede Strigamia maritima, and document a detailed time series of expression during trunk segmentation. We find supportive evidence for a conserved hierarchical organisation of the pair rule genes, with a division into early- and late-activated genes which parallels the functional division into primary and secondary pair rule genes described in insects. We confirm that the relative expression of sloppy-paired and paired with respect to wingless and engrailed at the parasegment boundary is conserved between myriapods and insects; suggesting that functional interactions between these genes might be an ancient feature of arthropod segment patterning. However, we find that the relative expression of a number of the primary pair rule genes is divergent between myriapods and insects. This corroborates suggestions that the evolution of upper tiers in the segmentation gene network is more flexible. Finally, we find that the expression of the Strigamia pair rule genes in periodic patterns is restricted to the ectoderm. This suggests that any direct role of these genes in segmentation is restricted to this germ layer, and that mesoderm segmentation is either dependent on the ectoderm, or occurs through an independent mechanism. PMID:23810931

  1. Crystal structure of exo-inulinase from Aspergillus awamori: the enzyme fold and structural determinants of substrate recognition.

    PubMed

    Nagem, R A P; Rojas, A L; Golubev, A M; Korneeva, O S; Eneyskaya, E V; Kulminskaya, A A; Neustroev, K N; Polikarpov, I

    2004-11-19

    Exo-inulinases hydrolyze terminal, non-reducing 2,1-linked and 2,6-linked beta-d-fructofuranose residues in inulin, levan and sucrose releasing beta-d-fructose. We present the X-ray structure at 1.55A resolution of exo-inulinase from Aspergillus awamori, a member of glycoside hydrolase family 32, solved by single isomorphous replacement with the anomalous scattering method using the heavy-atom sites derived from a quick cryo-soaking technique. The tertiary structure of this enzyme folds into two domains: the N-terminal catalytic domain of an unusual five-bladed beta-propeller fold and the C-terminal domain folded into a beta-sandwich-like structure. Its structural architecture is very similar to that of another member of glycoside hydrolase family 32, invertase (beta-fructosidase) from Thermotoga maritima, determined recently by X-ray crystallography The exo-inulinase is a glycoprotein containing five N-linked oligosaccharides. Two crystal forms obtained under similar crystallization conditions differ by the degree of protein glycosylation. The X-ray structure of the enzyme:fructose complex, at a resolution of 1.87A, reveals two catalytically important residues: Asp41 and Glu241, a nucleophile and a catalytic acid/base, respectively. The distance between the side-chains of these residues is consistent with a double displacement mechanism of reaction. Asp189, which is part of the Arg-Asp-Pro motif, provides hydrogen bonds important for substrate recognition. PMID:15522299

  2. Handling Temperature Bursts Reaching 464°C: Different Microbial Strategies in the Sisters Peak Hydrothermal Chimney

    PubMed Central

    Kurtz, Stefan; LaRoche, Julie

    2014-01-01

    The active venting Sisters Peak (SP) chimney on the Mid-Atlantic Ridge holds the current temperature record for the hottest ever measured hydrothermal fluids (400°C, accompanied by sudden temperature bursts reaching 464°C). Given the unprecedented temperature regime, we investigated the biome of this chimney with a focus on special microbial adaptations for thermal tolerance. The SP metagenome reveals considerable differences in the taxonomic composition from those of other hydrothermal vent and subsurface samples; these could be better explained by temperature than by other available abiotic parameters. The most common species to which SP genes were assigned were thermophilic Aciduliprofundum sp. strain MAR08-339 (11.8%), Hippea maritima (3.8%), Caldisericum exile (1.5%), and Caminibacter mediatlanticus (1.4%) as well as to the mesophilic Niastella koreensis (2.8%). A statistical analysis of associations between taxonomic and functional gene assignments revealed specific overrepresented functional categories: for Aciduliprofundum, protein biosynthesis, nucleotide metabolism, and energy metabolism genes; for Hippea and Caminibacter, cell motility and/or DNA replication and repair system genes; and for Niastella, cell wall and membrane biogenesis genes. Cultured representatives of these organisms inhabit different thermal niches; i.e., Aciduliprofundum has an optimal growth temperature of 70°C, Hippea and Caminibacter have optimal growth temperatures around 55°C, and Niastella grows between 10 and 37°C. Therefore, we posit that the different enrichment profiles of functional categories reflect distinct microbial strategies to deal with the different impacts of the local sudden temperature bursts in disparate regions of the chimney. PMID:24837379

  3. Effect of lectins from Diocleinae subtribe against oral Streptococci.

    PubMed

    Cavalcante, Theodora Thays Arruda; Anderson Matias da Rocha, Bruno; Alves Carneiro, Victor; Vassiliepe Sousa Arruda, Francisco; Fernandes do Nascimento, Antônia Sâmia; Cardoso Sá, Nairley; do Nascimento, Kyria Santiago; Sousa Cavada, Benildo; Holanda Teixeira, Edson

    2011-01-01

    Surface colonization is an essential step in biofilm development. The ability of oral pathogens to adhere to tooth surfaces is directly linked with the presence of specific molecules at the bacterial surface that can interact with enamel acquired pellicle ligands. In light of this, the aim of this study was to verify inhibitory and antibiofilm action of lectins from the Diocleinaesubtribe against Streptococcus mutans and Streptococcus oralis. The inhibitory action against planctonic cells was assessed using lectins from Canavaliaensi formis (ConA), Canavalia brasiliensis (ConBr), Canavalia maritima (ConM), Canavalia gladiata (CGL) and Canavalia boliviana (ConBol). ConBol, ConBr and ConM showed inhibitory activity on S. mutans growth. All lectins, except ConA, stimulated significantly the growth of S. oralis. To evaluate the effect on biofilm formation, clarified saliva was added to 96-well, flat-bottomed polystyrene plates, followed by the addition of solutions containing 100 or 200 µg/mL of the selected lectins. ConBol, ConM and ConA inhibited the S. mutans biofilms. No effects were found on S. oralis biofilms. Structure/function analysis were carried out using bioinformatics tools. The aperture and deepness of the CRD (Carbohydrate Recognition Domain) permit us to distinguish the two groups of Canavalia lectins in accordance to their actions against S. mutans and S. oralis. The results found provide a basis for encouraging the use of plant lectins as biotechnological tools in ecological control and prevention of caries disease. PMID:21525793

  4. Metal specificity is correlated with two crucial active site residues in Escherichia coli alkaline phosphatase.

    PubMed

    Wang, Jie; Stieglitz, Kimberly A; Kantrowitz, Evan R

    2005-06-14

    Escherichia coli alkaline phosphatase exhibits maximal activity when Zn(2+) fills the M1 and M2 metal sites and Mg(2+) fills the M3 metal site. When other metals replace the zinc and magnesium, the catalytic efficiency is reduced by more than 5000-fold. Alkaline phosphatases from organisms such as Thermotoga maritima and Bacillus subtilis require cobalt for maximal activity and function poorly with zinc and magnesium. Previous studies have shown that the D153H alkaline phosphatase exhibited very little activity in the presence of cobalt, while the K328W and especially the D153H/K328W mutant enzymes can use cobalt for catalysis. To understand the structural basis for the altered metal specificity and the ability of the D153H/K328W enzyme to utilize cobalt for catalysis, we determined the structures of the inactive wild-type E. coli enzyme with cobalt (WT_Co) and the structure of the active D153H/K328W enzyme with cobalt (HW_Co). The structural data reveal differences in the metal coordination and in the strength of the interaction with the product phosphate (P(i)). Since release of P(i) is the slow step in the mechanism at alkaline pH, the enhanced binding of P(i) in the WT_Co structure explains the observed decrease in activity, while the weakened binding of P(i) in the HW_Co structure explains the observed increase in activity. These alterations in P(i) affinity are directly related to alterations in the coordination of the metals in the active site of the enzyme. PMID:15938627

  5. Structural Insights Into Amino Acid Binding and Gene Control by a Lysine Riboswitch

    SciTech Connect

    Serganov, A.; Huang, L; Patel, D

    2008-01-01

    In bacteria, the intracellular concentration of several amino acids is controlled by riboswitches1, 2, 3, 4. One of the important regulatory circuits involves lysine-specific riboswitches, which direct the biosynthesis and transport of lysine and precursors common for lysine and other amino acids. To understand the molecular basis of amino acid recognition by riboswitches, here we present the crystal structure of the 174-nucleotide sensing domain of the Thermotoga maritima lysine riboswitch in the lysine-bound (1.9 A) and free (3.1 A) states. The riboswitch features an unusual and intricate architecture, involving three-helical and two-helical bundles connected by a compact five-helical junction and stabilized by various long-range tertiary interactions. Lysine interacts with the junctional core of the riboswitch and is specifically recognized through shape-complementarity within the elongated binding pocket and through several direct and K+-mediated hydrogen bonds to its charged ends. Our structural and biochemical studies indicate preformation of the riboswitch scaffold and identify conformational changes associated with the formation of a stable lysine-bound state, which prevents alternative folding of the riboswitch and facilitates formation of downstream regulatory elements. We have also determined several structures of the riboswitch bound to different lysine analogues5, including antibiotics, in an effort to understand the ligand-binding capabilities of the lysine riboswitch and understand the nature of antibiotic resistance. Our results provide insights into a mechanism of lysine-riboswitch-dependent gene control at the molecular level, thereby contributing to continuing efforts at exploration of the pharmaceutical and biotechnological potential of riboswitches.

  6. Frankia populations in soil and root nodules of sympatrically grown Alnus taxa.

    PubMed

    Pokharel, Anita; Mirza, Babur S; Dawson, Jeffrey O; Hahn, Dittmar

    2011-01-01

    The genetic diversity of Frankia populations in soil and in root nodules of sympatrically grown Alnus taxa was evaluated by rep-polymerase chain reaction (PCR) and nifH gene sequence analyses. Rep-PCR analyses of uncultured Frankia populations in root nodules of 12 Alnus taxa (n=10 nodules each) growing sympatrically in the Morton Arboretum near Chicago revealed identical patterns for nodules from each Alnus taxon, including replicate trees of the same host taxon, and low diversity overall with only three profiles retrieved. One profile was retrieved from all nodules of nine taxa (Alnus incana subsp. incana, Alnus japonica, Alnus glutinosa, Alnus incana subsp. tenuifolia, Alnus incana subsp. rugosa, Alnus rhombifolia, Alnus mandshurica, Alnus maritima, and Alnus serrulata), the second was found in all nodules of two plant taxa (A. incana subsp. hirsuta and A. glutinosa var. pyramidalis), and the third was unique for all Frankia populations in nodules of A. incana subsp. rugosa var. americana. Comparative sequence analyses of nifH gene fragments in nodules representing these three profiles assigned these frankiae to different subgroups within the Alnus host infection group. None of these sequences, however, represented frankiae detectable in soil as determined by sequence analysis of 73 clones from a Frankia-specific nifH gene clone library. Additional analyses of nodule populations from selected alders growing on different soils demonstrated the presence of different Frankia populations in nodules for each soil, with populations showing identical sequences in nodules from the same soil, but differences between plant taxa. These results suggest that soil environmental conditions and host plant genotype both have a role in the selection of Frankia strains by a host plant for root nodule formation, and that this selection is not merely a function of the abundance of a Frankia strain in soil. PMID:20838787

  7. Structure of the invertebrate fauna in salt marshes of the Wadden Sea coast of Schleswig-Holstein influenced by sheep-grazing

    NASA Astrophysics Data System (ADS)

    Meyer, H.; Fock, H.; Haase, A.; Reinke, H. D.; Tulowitzki, I.

    1995-03-01

    Results of investigations on the influence of five different sheep grazing intensities on the invertebrate fauna of two mainland salt marsh sites of the German Wadden Sea coast are presented for the years 1990 and 1991. The investigation of the invertebrate fauna has been carried out since 1989 in the Puccinellia maritima zone, and the Festuca-Puccinellia as well as the Festuca-Armeria zones, with trapping transects arranged along an inundation gradient. Apart from specific biotic effects, grazing causes changes in environmental characteristics. Effects on microclimate comprise higher ranges of variance in soil-surface temperature on grazed sites. Decreasing food resources caused by grazing bring disadvantages to herbivores, the major part of the invertebrate fauna, due to merotope destruction (e. g. inflorescences of Aster tripolium) and the decline of host plant stands (e. g. A. tripolium, Plantago ssp.). Flower visitors and pollen feeding species that depend on A. tripolium have become extinct. Increasing food resources, caused by grazing, lead to higher population densities of a few specialized grass-feeding and surface-grazing invertebrates (e. g. Mayetiola ssp., Psammotettix putoni, Bledius tricornis). Soil characteristics in the lower salt marsh have not been altered significantly by grazing; hence, the direct effect of grazing and trampling leads to a decrease in population density of many species such as Assiminea grayana, Orchestia gammarellus and collembolans. The biomass and abundance of detritivores and many herbivores increased from 1990 to 1991 on the totally grazed fields, whereas predators diminished in numbers at the same time. A descriptive model is presented, involving grazing, winter temperature, and precipitation as basic factors.

  8. Comparison of bulk and compound-specific ? 13C analyses and determination of carbon sources to salt marsh sediments using n-alkane distributions (Maine, USA)

    NASA Astrophysics Data System (ADS)

    Tanner, Benjamin R.; Uhle, Maria E.; Mora, Claudia I.; Kelley, Joseph T.; Schuneman, Patrick J.; Lane, Chad S.; Allen, Evan S.

    2010-01-01

    Sources of sedimentary organic matter to a Morse River, Maine (USA) salt marsh over the last 3390 ± 60 RCYBP (Radiocarbon Years Before Present) are determined using distribution patterns of n-alkanes, bulk carbon isotopic analysis, and compound-specific carbon isotopic analysis. Marsh foraminiferal counts suggest a ubiquitous presence of high marsh and higher-high marsh deposits (dominated by Trochammina macrescens forma macrescens, Trochammina comprimata, and Trochammina inflata), implying deposition from ˜0.2 m to 0.5 m above mean high water. Distributions of n-alkanes show a primary contribution from higher plants, confirmed by an average chain length value of 27.5 for the core sediments, and carbon preference index values all >3. Many sample depths are dominated by the C 25 alkane. Salicornia depressa and Ruppia maritima have similar n-alkane distributions to many of the salt marsh sediments, and we suggest that one or both of these plants is either an important source to the biomass of the marsh through time, or that another unidentified higher plant source is contributing heavily to the sediment pool. Bacterial degradation or algal inputs to the marsh sediments appear to be minor. Compound-specific carbon isotopic analyses of the C 27 alkane are on average 7.2‰ depleted relative to bulk values, but the two records are strongly correlated ( R2 = 0.89), suggesting that marsh plants dominate the bulk carbon isotopic signal. Our study underscores the importance of using caution when applying mixing models of plant species to salt marsh sediments, especially when relatively few plants are included in the model.

  9. Occurrence of sulfated galactans in marine angiosperms: evolutionary implications.

    PubMed

    Aquino, Rafael S; Landeira-Fernandez, Ana M; Valente, Ana Paula; Andrade, Leonardo R; Mourão, Paulo A S

    2005-01-01

    We report for the first time that marine angiosperms (seagrasses) possess sulfated polysaccharides, which are absent in terrestrial and freshwater plants. The structure of the sulfated polysaccharide from the seagrass Ruppia maritima was determined. It is a sulfated D-galactan composed of the following regular tetrasaccharide repeating unit: [3-beta-D-Gal-2(OSO3)-1-->4-alpha-D-Gal-1-->4-alpha-D-Gal-1-->3-beta-D-Gal-4(OSO3)-1-->]. Sulfated galactans have been described previously in red algae and in marine invertebrates (ascidians and sea urchins). The sulfated galactan from the marine angiosperm has an intermediate structure when compared with the polysaccharides from these two other groups of organisms. Like marine invertebrate galactan, it expresses a regular repeating unit with a homogenous sulfation pattern. However, seagrass galactan contains the D-enantiomer of galactose instead of the L-isomer found in marine invertebrates. Like red algae, the marine angiosperm polysaccharide contains both alpha and beta units of D-galactose; however, these units are not distributed in an alternating order, as in algal galactan. Sulfated galactan is localized in the plant cell walls, mostly in rhizomes and roots, indicative of a relationship with the absorption of nutrients and of a possible structural function. The occurrence of sulfated galactans in marine organisms may be the result of physiological adaptations, which are not correlated with phylogenetic proximity. We suggest that convergent adaptation, due to environment pressure, may explain the occurrence of sulfated galactans in many marine organisms. PMID:15317737

  10. Isotopic variation of fishes in freshwater and estuarine zones of a large subtropical coastal lagoon

    NASA Astrophysics Data System (ADS)

    Garcia, A. M.; Hoeinghaus, D. J.; Vieira, J. P.; Winemiller, K. O.

    2007-07-01

    We used stable C and N isotope ratios of tissues from 29 fish species from a large subtropical lagoon in southern Brazil to examine spatial variability in isotopic composition and vertical trophic structure across freshwater and estuarine habitats. Nitrogen isotope ratios indicated a smooth gradation in trophic positions among species, with most fishes occupying the secondary and tertiary consumer level. Fish assemblages showed a significant shift in their carbon isotopic signatures between freshwater and estuarine sites. Depleted carbon signatures (from -24.7‰ to -17.8‰) were found in freshwater, whereas more enriched signatures (from -19.1‰ to -12.3‰) were obtained within the estuarine zone downstream. Based on our survey of the C 3 and C 4 plants and isotopic values for phytoplankton and benthic microalgae reported for ecosystems elsewhere, we hypothesized that the observed ?13C differences in the fish assemblage between freshwater and estuarine sites is due to a shift from assimilating organic matter ultimately derived from C 3 freshwater marsh vegetation and phytoplankton at the freshwater site ( ?13C ranging from -25‰ to -19‰), to C 4 salt-marsh (e.g. Spartina) and widgeon grass ( Ruppia maritima), benthic microalgae and marine phytoplankton at the estuarine sites (from -18‰ to -12‰). Our results suggested that fish assemblages are generally supported by autochthonous primary production. Freshwater fishes that likely were displaced downstream into the estuary during periods of high freshwater discharge had depleted ?13C values that were characteristic of the upper lagoon. These results suggest that spatial foodweb subsidies can occur within the lagoon.

  11. Establishing Minimum Flow Requirements Based on Benthic Vegetation: What are Some Issues Related to Identifying Quantity of Inflow and Tools Used to Quantify Ecosystem Response?

    NASA Astrophysics Data System (ADS)

    Hunt, M. J.; Nuttle, W. K.; Cosby, B. J.; Marshall, F. E.

    2005-05-01

    Establishing minimum flow requirements in aquatic ecosystems is one way to stipulate controls on water withdrawals in a watershed. The basis of the determination is to identify the amount of flow needed to sustain a threshold ecological function. To develop minimum flow criteria an understanding of ecological response in relation to flow is essential. Several steps are needed including: (1) identification of important resources and ecological functions, (2) compilation of available information, (3) determination of historical conditions, (4) establishment of technical relationships between inflow and resources, and (5) identification of numeric criteria that reflect the threshold at which resources are harmed. The process is interdisciplinary requiring the integration of hydrologic and ecologic principles with quantitative assessments. The tools used quantify the ecological response and key questions related to how the quantity of flow influences the ecosystem are examined by comparing minimum flow determination in two different aquatic systems in South Florida. Each system is characterized by substantial hydrologic alteration. The first, the Caloosahatchee River is a riverine system, located on the southwest coast of Florida. The second, the Everglades- Florida Bay ecotone, is a wetland mangrove ecosystem, located on the southern tip of the Florida peninsula. In both cases freshwater submerged aquatic vegetation (Vallisneria americana or Ruppia maritima), located in areas of the saltwater- freshwater interface has been identified as a basis for minimum flow criteria. The integration of field studies, laboratory studies, and literature review was required. From this information we developed ecological modeling tools to quantify and predict plant growth in response to varying environmental variables. Coupled with hydrologic modeling tools questions relating to the quantity and timing of flow and ecological consequences in relation to normal variability are addressed.

  12. Photorespiration and Carbon Limitation Determine Productivity in Temperate Seagrasses

    PubMed Central

    Buapet, Pimchanok; Rasmusson, Lina M.; Gullström, Martin; Björk, Mats

    2013-01-01

    The gross primary productivity of two seagrasses, Zostera marina and Ruppia maritima, and one green macroalga, Ulva intestinalis, was assessed in laboratory and field experiments to determine whether the photorespiratory pathway operates at a substantial level in these macrophytes and to what extent it is enhanced by naturally occurring shifts in dissolved inorganic carbon (DIC) and O2 in dense vegetation. To achieve these conditions in laboratory experiments, seawater was incubated with U. intestinalis in light to obtain a range of higher pH and O2 levels and lower DIC levels. Gross photosynthetic O2 evolution was then measured in this pretreated seawater (pH, 7.8–9.8; high to low DIC:O2 ratio) at both natural and low O2 concentrations (adjusted by N2 bubbling). The presence of photorespiration was indicated by a lower gross O2 evolution rate under natural O2 conditions than when O2 was reduced. In all three macrophytes, gross photosynthetic rates were negatively affected by higher pH and lower DIC. However, while both seagrasses exhibited significant photorespiratory activity at increasing pH values, the macroalga U. intestinalis exhibited no such activity. Rates of seagrass photosynthesis were then assessed in seawater collected from the natural habitats (i.e., shallow bays characterized by high macrophyte cover and by low DIC and high pH during daytime) and compared with open baymouth water conditions (where seawater DIC is in equilibrium with air, normal DIC, and pH). The gross photosynthetic rates of both seagrasses were significantly higher when incubated in the baymouth water, indicating that these grasses can be significantly carbon limited in shallow bays. Photorespiration was also detected in both seagrasses under shallow bay water conditions. Our findings indicate that natural carbon limitations caused by high community photosynthesis can enhance photorespiration and cause a significant decline in seagrass primary production in shallow waters. PMID:24376754

  13. Seagrass distribution and abundance in Eastern Gulf of Mexico coastal waters

    NASA Astrophysics Data System (ADS)

    Iverson, Richard L.; Bittaker, Henry F.

    1986-05-01

    The marine angiosperms Thalassia testudinum, Syringodium filiforme, and Halodule wrightii form two of the largest reported seagrass beds along the northwest and southern coasts of Florida where they cover about 3000 square km in the Big Bend area and about 5500 square km in Florida Bay, respectively. Most of the leaf biomass in the Big Bend area and outer Florida Bay was composed of Thalassia testudinum and Syringodium filiforme which were distributed throughout the beds but which were more abundant in shallow depths. A short-leaved form of Halodule wrightii grew in monotypic stands in shallow water near the inner edges of the beds, while Halophila decipiens and a longer-leaved variety of H. wrightii grew scattered throughout the beds, in monotypic stands near the outer edges of the beds, and in deeper water outside the beds. Halophila engelmanni was observed scattered at various depths throughout the seagrass beds and in monospecific patches in deep water outside the northern bed. Ruppia maritima grew primarily in brackish water around river mouths. The cross-shelf limits of the two major seagrass beds are controlled nearshore by increased water turbidity and lower salinity around river mouths and off-shore by light penetration to depths which receive 10% or more of sea surface photosynthetically active radiation. Seagrasses form large beds only along low energy reaches of the coast. The Florida Bay seagrass bed contained about twice the short-shoot density of both Thalassia testudinum and Syringodium filiforme, for data averaged over all depths, and about four times the average short-shoot density of both species in shallow water compared with the Big Bend seagrass bed. The differences in average seagrass abundance between Florida Bay and the Big Bend area may be a consequence of the effects of greater seasonal solar radiation and water temperature fluctuations experienced by plants in the northern bed, which lies at the northern distribution limit for American Tropical seagrasses.

  14. Ocean acidification and the loss of phenolic substances in marine plants.

    PubMed

    Arnold, Thomas; Mealey, Christopher; Leahey, Hannah; Miller, A Whitman; Hall-Spencer, Jason M; Milazzo, Marco; Maers, Kelly

    2012-01-01

    Rising atmospheric CO(2) often triggers the production of plant phenolics, including many that serve as herbivore deterrents, digestion reducers, antimicrobials, or ultraviolet sunscreens. Such responses are predicted by popular models of plant defense, especially resource availability models which link carbon availability to phenolic biosynthesis. CO(2) availability is also increasing in the oceans, where anthropogenic emissions cause ocean acidification, decreasing seawater pH and shifting the carbonate system towards further CO(2) enrichment. Such conditions tend to increase seagrass productivity but may also increase rates of grazing on these marine plants. Here we show that high CO(2) / low pH conditions of OA decrease, rather than increase, concentrations of phenolic protective substances in seagrasses and eurysaline marine plants. We observed a loss of simple and polymeric phenolics in the seagrass Cymodocea nodosa near a volcanic CO(2) vent on the Island of Vulcano, Italy, where pH values decreased from 8.1 to 7.3 and pCO(2) concentrations increased ten-fold. We observed similar responses in two estuarine species, Ruppia maritima and Potamogeton perfoliatus, in in situ Free-Ocean-Carbon-Enrichment experiments conducted in tributaries of the Chesapeake Bay, USA. These responses are strikingly different than those exhibited by terrestrial plants. The loss of phenolic substances may explain the higher-than-usual rates of grazing observed near undersea CO(2) vents and suggests that ocean acidification may alter coastal carbon fluxes by affecting rates of decomposition, grazing, and disease. Our observations temper recent predictions that seagrasses would necessarily be "winners" in a high CO(2) world. PMID:22558120

  15. Photorespiration and carbon limitation determine productivity in temperate seagrasses.

    PubMed

    Buapet, Pimchanok; Rasmusson, Lina M; Gullström, Martin; Björk, Mats

    2013-01-01

    The gross primary productivity of two seagrasses, Zostera marina and Ruppia maritima, and one green macroalga, Ulva intestinalis, was assessed in laboratory and field experiments to determine whether the photorespiratory pathway operates at a substantial level in these macrophytes and to what extent it is enhanced by naturally occurring shifts in dissolved inorganic carbon (DIC) and O2 in dense vegetation. To achieve these conditions in laboratory experiments, seawater was incubated with U. intestinalis in light to obtain a range of higher pH and O2 levels and lower DIC levels. Gross photosynthetic O2 evolution was then measured in this pretreated seawater (pH, 7.8-9.8; high to low DIC:O2 ratio) at both natural and low O2 concentrations (adjusted by N2 bubbling). The presence of photorespiration was indicated by a lower gross O2 evolution rate under natural O2 conditions than when O2 was reduced. In all three macrophytes, gross photosynthetic rates were negatively affected by higher pH and lower DIC. However, while both seagrasses exhibited significant photorespiratory activity at increasing pH values, the macroalga U. intestinalis exhibited no such activity. Rates of seagrass photosynthesis were then assessed in seawater collected from the natural habitats (i.e., shallow bays characterized by high macrophyte cover and by low DIC and high pH during daytime) and compared with open baymouth water conditions (where seawater DIC is in equilibrium with air, normal DIC, and pH). The gross photosynthetic rates of both seagrasses were significantly higher when incubated in the baymouth water, indicating that these grasses can be significantly carbon limited in shallow bays. Photorespiration was also detected in both seagrasses under shallow bay water conditions. Our findings indicate that natural carbon limitations caused by high community photosynthesis can enhance photorespiration and cause a significant decline in seagrass primary production in shallow waters. PMID:24376754

  16. Ingestion, enzymatic digestion and absorption of particles derived from different vegetal sources by the cockle Cerastoderma edule

    NASA Astrophysics Data System (ADS)

    Arambalza, U.; Urrutia, M. B.; Navarro, E.; Ibarrola, I.

    2010-10-01

    Ingestion, enzymatic digestion and absorption of particulate detrital matter derived from six different vegetal sources by the common cockle Cerastoderma edule was analyzed in a series of seasonal experiments performed in March, May and October 2005. Two green macroalgae: Ulva lactuca and Enteromorpha sp; two vascular plants: Spartina maritima and Juncus maritimus, the red macroalgae Gracilaria gracilis; and the microalgae Isochrysis galbana were used in experiments. Detrital matter was elaborated by freeze-drying, grinding and sieving (< 63 ?m) vegetal tissues. Mono-specific detrital diets of similar organic content (? 60-70%) were elaborated by mixing detritus with ashed silt. We measured i) the biochemical composition of different detritus, ii) physiological components of the absorptive balance (i.e. clearance, ingestion, rejection and absorption rate and absorption efficiency), iii) the capability of the digestive gland to hydrolyze carbohydrates from different detritus (digestibility), as well as iv) glandular cellulase and xylanase activities. Detritus type, season and the interaction detritus-season exerted significant effects upon all the physiological components of absorptive balance. Effects were light at the pre-absorptive level, however, huge variations associated to absorption efficiency promoted large significant differences in absorption rates (AR) of different kind of detritus: irrespective of season, highest values corresponded to cockles fed the green macroalgae ( Ulva and Enteromorpha) and lowest to those fed the vascular plant Juncus maritimus. Recorded significant differences in enzymatic digestibility among detritus were found to explain ? 40% of differences recorded in AR, and the following regression could be fitted: AR = 0.232 (± 0.032) * Digestibility + 0,072 (± 0.015); r 2 = 0.415; F = 51.036; p < 0.001. Digestibility of Ulva and Enteromorpha was found to be significantly correlated with cellulase activity in the digestive gland, whereas digestibility of Juncus, Spartina and Gracilaria was correlated with xylanase activity. Obtained correlations are discussed in the frame of contrasting conclusions in the literature regarding the importance of detritus as a food source for bivalves.

  17. Potassium Acts as a GTPase-Activating Element on Each Nucleotide-Binding Domain of the Essential Bacillus subtilis EngA

    PubMed Central

    Foucher, Anne-Emmanuelle; Reiser, Jean-Baptiste; Ebel, Christine; Housset, Dominique; Jault, Jean-Michel

    2012-01-01

    EngA proteins form a unique family of bacterial GTPases with two GTP-binding domains in tandem, namely GD1 and GD2, followed by a KH (K-homology) domain. They have been shown to interact with the bacterial ribosome and to be involved in its biogenesis. Most prokaryotic EngA possess a high GTPase activity in contrast to eukaryotic GTPases that act mainly as molecular switches. Here, we have purified and characterized the GTPase activity of the Bacillus subtilis EngA and two shortened EngA variants that only contain GD1 or GD2-KH. Interestingly, the GTPase activity of GD1 alone is similar to that of the whole EngA, whereas GD2-KH has a 150-fold lower GTPase activity. At physiological concentration, potassium strongly stimulates the GTPase activity of each protein construct. Interestingly, it affects neither the affinities for nucleotides nor the monomeric status of EngA or the GD1 domain. Thus, potassium likely acts as a chemical GTPase-activating element as proposed for another bacterial GTPase like MnmE. However, unlike MnmE, potassium does not promote dimerization of EngA. In addition, we solved two crystal structures of full-length EngA. One of them contained for the first time a GTP-like analogue bound to GD2 while GD1 was free. Surprisingly, its overall fold was similar to a previously solved structure with GDP bound to both sites. Our data indicate that a significant structural change must occur upon K+ binding to GD2, and a comparison with T. maritima EngA and MnmE structures allowed us to propose a model explaining the chemical basis for the different GTPase activities of GD1 and GD2. PMID:23056455

  18. The Arabidopsis basic leucine zipper transcription factor AtbZIP24 regulates complex transcriptional networks involved in abiotic stress resistance.

    PubMed

    Yang, Oksoon; Popova, Olga V; Süthoff, Ulrike; Lüking, Ines; Dietz, Karl-Josef; Golldack, Dortje

    2009-05-01

    Soil salinity severely affects plant growth and agricultural productivity. AtbZIP24 encodes a bZIP transcription factor that is induced by salt stress in Arabidopsis thaliana but suppressed in the salt-tolerant relative Lobularia maritima. Transcriptional repression of AtbZIP24 using RNA interference improved salt tolerance in A. thaliana. Under non-stress growth conditions, transgenic A. thaliana lines with decreased AtbZIP24 expression activated the expression of stress-inducible genes involved in cytoplasmic ion homeostasis and osmotic adjustment: the Na(+) transporter AtHKT1, the Na(+)/H(+) antiporter AtSOS1, the aquaporin AtPIP2.1, and a glutamine synthetase. In addition, candidate target genes of AtbZIP24 with functions in plant growth and development were identified such as an argonaute (AGO1)-related protein and cyclophilin AtCYP19. The salt tolerance in transgenic plants correlated with reduced Na(+) accumulation in leaves. In vivo interaction of AtbZIP24 as a homodimer was shown using fluorescence energy transfer (FRET) with cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP) as fused FRET pairs. Translational fusion of AtbZIP24 with GFP showed subcellular localization of the protein in nucleus and cytoplasm in plants grown under control conditions whereas in response to salt stress AtbZIP24 was preferentially targeted to the nucleus. It is concluded that AtbZIP24 is an important regulator of salt stress response in plants. The modification of transcriptional control by regulatory transcription factors provides a useful strategy for improving salt tolerance in plants. PMID:19248824

  19. A hydrogenosomal [Fe]-hydrogenase from the anaerobic chytrid Neocallimastix sp. L2.

    PubMed

    Voncken, Frank G J; Boxma, Brigitte; van Hoek, Angela H A M; Akhmanova, Anna S; Vogels, Godfried D; Huynen, Martijn; Veenhuis, Marten; Hackstein, Johannes H P

    2002-02-01

    The presence of a [Fe]-hydrogenase in the hydrogenosomes of the anaerobic chytridiomycete fungus Neocallimastix sp. L2 has been demonstrated by immunocytochemistry, subcellular fractionation, Western-blotting and measurements of hydrogenase activity in the presence of various concentrations of carbon monoxide (CO). Since the hydrogenosomal hydrogenase activity can be inhibited nearly completely by low concentrations of CO, it is likely that the [Fe]-hydrogenase is responsible for at least 90% of the hydrogen production in isolated hydrogenosomes. Most likely, this hydrogenase is encoded by the gene hydL2 that exhibits all the motifs that are characteristic of [Fe]-hydrogenases. The open reading frame starts with an N-terminal extension of 38 amino acids that has the potential to function as a hydrogenosomal targeting signal. The downstream sequences encode an enzyme of a calculated molecular mass of 66.4 kDa that perfectly matches the molecular mass of the mature hydrogenase in the hydrogenosome. Phylogenetic analysis revealed that the hydrogenase of Neocallimastix sp. L2. clusters together with similar ('long-type') [Fe]-hydrogenases from Trichomonas vaginalis, Nyctotherus ovalis, Desulfovibrio vulgaris and Thermotoga maritima. Phylogenetic analysis based on the H-cluster - the only module of [Fe]-hydrogenases that is shared by all types of [Fe]-hydrogenases and hydrogenase-like proteins - revealed a monophyly of all hydrogenase-like proteins of the aerobic eukaryotes. Our analysis suggests that the evolution of the various [Fe]-hydrogenases and hydrogenase-like proteins occurred by a differential loss of Fe-S clusters in the N-terminal part of the [Fe]-hydrogenase. PMID:11891051

  20. MULCHES AND OTHER COVER MATERIALS TO REDUCE WEED GROWTH IN CONTAINER-GROWN NURSERY STOCK.

    PubMed

    Rys, F; Van Wesemael, D; Van Haecke, D; Mechant, E; Gobin, B

    2014-01-01

    Due to the recent EU-wide implementation of Integrated Pest Management (IPM), alternative methods to reduce weed growth in container-grown nursery stock are needed to cut back the use of herbicides. Covering the upper layer of the substrate is known as a potential method to prevent or reduce weed growth in plant containers. As a high variety of mulches and other cover materials are on the market, however, it is no longer clear for growers which cover material is most efficient for use in containers. Therefore, we examined the effect on weed growth of different mulches and other cover materials, including Pinus maritima, P. sylvestris, Bio-Top Basic, Bio-Top Excellent, coco chips fine, hemp fibres, straw pellets, coco disk 180LD and jute disk. Cover materials were applied immediately after repotting of Ligustrum ovalifolium or planting of Fagus sylvatica. At regular times, both weed growth and side effects (e.g., plant growth, water status of the substrate, occurrence of mushrooms, foraging of birds, complete cover of the substrate and fixation) were assessed. All examined mulches or other cover materials were able to reduce weed growth on the containers during the whole growing season. Weed suppression was even better than that of a chemical treated control. Although all materials showed some side effects, the impact on plant growth is most important to the grower and depends not only on material characteristics (e.g., biodegradation, nutrient leaching and N-immobilisation) but also on container size and climatic conditions. In conclusion, mulches and other cover materials can be a valuable tool within IPM to lower herbicide use. To enable a deliberate choice of which cover material is best used in a specific situation more research is needed on lifespan and stability as well as on economic characteristics of the materials. PMID:26084081

  1. Conformational Changes of the Clamp of the Protein Translocation ATPase SecA.

    PubMed

    Chen, Yu; Bauer, Benedikt W; Rapoport, Tom A; Gumbart, James C

    2015-07-17

    Post-translational protein translocation across the bacterial plasma membrane is mediated by the interplay of the SecA ATPase and the protein-conducting SecY channel. SecA consists of several domains, including two nucleotide-binding domains (NBD1 and NBD2), a polypeptide cross-linking domain (PPXD), a helical scaffold domain (HSD), and a helical wing domain (HWD). PPXD, HSD, and NBD2 form a clamp that positions the polypeptide substrate above the channel so that it can be pushed into the channel by a two-helix finger of the HSD. How the substrate is accommodated in the clamp during translocation is unclear. Here, we report a crystal structure of Thermotoga maritima SecA at 1.9Å resolution. Structural analysis and free-energy calculations indicate that the new structure represents an intermediate state during the transition of the clamp from an open to a closed conformation. Molecular dynamics simulations show that closure of the clamp occurs in two phases, an initial movement of PPXD, HSD, and HWD as a unit, followed by a movement of PPXD alone toward NBD2. Simulations in the presence of a polypeptide chain show that the substrate associates with the back of the clamp by dynamic hydrogen bonding and that the clamp is laterally closed by a conserved loop of the PPXD. Mutational disruption of clamp opening or closure abolishes protein translocation. These results suggest how conformational changes of SecA allow substrate binding and movement during protein translocation. PMID:25982945

  2. Characterization of RimO, a New Member of the Methylthiotransferase Subclass of the Radical SAM Superfamily†

    PubMed Central

    Lee, Kyung-Hoon; Saleh, Lana; Anton, Brian P.; Madinger, Catherine L.; Benner, Jack S.; Iwig, David F.; Roberts, Richard J.; Krebs, Carsten; Booker, Squire J.

    2009-01-01

    RimO, encoded by the yliG gene in Escherichia coli, has been recently identified in vivo as the enzyme responsible for the attachment of a methylthio group on the ?-carbon of Asp88 of the small ribosomal protein S12 [Anton, B. P., Saleh, L., Benner, J. S., Raleigh, E. A., Kasif, S., and Roberts, R. J. (2008) Proc. Natl. Acad. Sci. USA, 105, 1826–1831]. To date, it is the only enzyme known to catalyze methylthiolation of a protein substrate; the four other naturally occurring methylthio modifications have been observed on tRNA. All members of the methylthiotransferase (MTTase) family, to which RimO belongs, have been shown to contain the canonical CxxxCxxC motif in their primary structures that is typical of the radical S-adenosylmethionine (SAM) family of proteins. MiaB, the only characterized MTTase, and the enzyme experimentally shown to be responsible for methylthiolation of N6-isopentenyladenosine of tRNA in E. coli and Thermotoga maritima, has been demonstrated to harbor two distinct [4Fe–4S] clusters. Herein, we report in vitro biochemical, and spectroscopic characterization of RimO. We show by analytical and spectroscopic methods that RimO, heterologously overproduced in E. coli in the presence of iron–sulfur cluster biosynthesis proteins from Azotobacter vinelandii, contains one [4Fe–4S]2+ cluster. Reconstitution of this form of RimO (RimOrcn) with 57Fe and sodium sulfide results in a protein that contains two [4Fe–4S]2+ clusters, similar to MiaB. We also show by mass spectrometry that RimOrcn catalyzes the attachment of a methylthio group to a peptide substrate analog that mimics the loop structure bearing aspartyl 88 of the S12 ribosomal protein from E. coli. Kinetic analysis of this reaction shows that the activity of RimOrcn in the presence of the substrate analog does not support a complete turnover. We discuss the possible requirement for an assembled ribosome for fully active RimO in vitro. Our findings are consistent with those of other enzymes that catalyze sulfur insertion, such as biotin synthase, lipoyl synthase, and MiaB. PMID:19736993

  3. Evolutionary insights about bacterial GlxRS from whole genome analyses: is GluRS2 a chimera?

    PubMed Central

    2014-01-01

    Background Evolutionary histories of glutamyl-tRNA synthetase (GluRS) and glutaminyl-tRNA synthetase (GlnRS) in bacteria are convoluted. After the divergence of eubacteria and eukarya, bacterial GluRS glutamylated both tRNAGln and tRNAGlu until GlnRS appeared by horizontal gene transfer (HGT) from eukaryotes or a duplicate copy of GluRS (GluRS2) that only glutamylates tRNAGln appeared. The current understanding is based on limited sequence data and not always compatible with available experimental results. In particular, the origin of GluRS2 is poorly understood. Results A large database of bacterial GluRS, GlnRS, tRNAGln and the trimeric aminoacyl-tRNA-dependent amidotransferase (gatCAB), constructed from whole genomes by functionally annotating and classifying these enzymes according to their mutual presence and absence in the genome, was analyzed. Phylogenetic analyses showed that the catalytic and the anticodon-binding domains of functional GluRS2 (as in Helicobacter pylori) were independently acquired from evolutionarily distant hosts by HGT. Non-functional GluRS2 (as in Thermotoga maritima), on the other hand, was found to contain an anticodon-binding domain appended to a gene-duplicated catalytic domain. Several genomes were found to possess both GluRS2 and GlnRS, even though they share the common function of aminoacylating tRNAGln. GlnRS was widely distributed among bacterial phyla and although phylogenetic analyses confirmed the origin of most bacterial GlnRS to be through a single HGT from eukarya, many GlnRS sequences also appeared with evolutionarily distant phyla in phylogenetic tree. A GlnRS pseudogene could be identified in Sorangium cellulosum. Conclusions Our analysis broadens the current understanding of bacterial GlxRS evolution and highlights the idiosyncratic evolution of GluRS2. Specifically we show that: i) GluRS2 is a chimera of mismatching catalytic and anticodon-binding domains, ii) the appearance of GlnRS and GluRS2 in a single bacterial genome indicating that the evolutionary histories of the two enzymes are distinct, iii) GlnRS is more widespread in bacteria than is believed, iv) bacterial GlnRS appeared both by HGT from eukarya and intra-bacterial HGT, v) presence of GlnRS pseudogene shows that many bacteria could not retain the newly acquired eukaryal GlnRS. The functional annotation of GluRS, without recourse to experiments, performed in this work, demonstrates the inherent and unique advantages of using whole genome over isolated sequence databases. PMID:24521160

  4. The comparison of composite aircraft field repair method (cafrm) with traditional aircraft repair technologies

    NASA Astrophysics Data System (ADS)

    Whelan, Mary Elizabeth

    The sulfur biogeochemical cycle includes biotic and abiotic processes important to global climate, atmospheric chemistry, food security, and the study of related cycles. The largest flux of sulfur on Earth is weathering from the continents into the sulfate-rich oceans; one way in which sulfur can be returned to land is through transport of reduced sulfur gases via the atmosphere. Here I developed a method for quantifying low-level environmental fluxes of several sulfur-containing gases, H2S, COS, CH3SCH 3 (DMS), and HSCH3, between terrestrial ecosystems and the atmosphere. COS is the most prevalent reduced sulfur gas in the atmosphere, considered to be inert in the troposphere except for its uptake in plant leaves and to a smaller extent aerobic soils. This dissertation reports two surprising cases that go against conventional thinking about the sulfur cycle. We found that the common salt marsh plant Batis maritima can mediate net COS production to the atmosphere. We also found that an aerobic wheat field soil produces COS abiotically when incubated in the dark at > 25 °C and at lower temperatures under light conditions. We then sought to separately quantify plant and soil sulfur gas fluxes by undertaking a year-long field campaign in a grassland with a Mediterranean climate, where green plants were present only half of the year. We measured in situ soil fluxes of COS and DMS during the non- growing dry season, using water additions to simulate soil fluxes of the growing, wet season. COS and CO2 are consumed in a predictable ratio by enzymes involved in photosynthetic pathways; however, while CO2 is released by back diffusion and autorespiration, COS is usually not generated by plants. Using measurements during the growing season, we were then able to calculate gross primary production by using the special relationship between CO2 and COS. This dissertation has developed a greater understanding of the vagaries of the atmospheric-terrestrial sulfur cycle and explored using that cycle as a tool for studying the carbon cycle.

  5. Implications of Small-Scale Superimposed Bedforms on the Morphodynamics and Sediment Transport Patterns on the Lower Shoreface in the Southern North Sea

    NASA Astrophysics Data System (ADS)

    Noormets, R.; Flemming, B.; Ernstsen, V.; Winter, C.; Hebbeln, D.

    2004-12-01

    Shoreface connected ridges (length up to a few kilometers, height up to a few meters) on the shoreface of the Island of Spiekeroog in the southern North Sea have been shown to be rather stable over decades and possibly hundreds of years (Flemming and Davis 1994). Recent high-resolution multibeam bathymetric surveys have revealed patterns of small-scale bedforms (length and height up to 10 m and 0.3 m, respectively) superimposed on the ridge-trough morphology across the entire lower shoreface. In general, the flood current velocities, measured at 1 m above the bottom are as much as 47% higher than ebb counterparts (Antia et al., 1995). Exceptions are the landward flanks of and troughs between the shoreface connected ridges where higher ebb velocities have been recorded. The superimposed megaripple-scale bedforms imply a net shoreward sediment transport on the seaward flanks of the shoreface connected ridges at a low angle to the ridge crest. Sediment reaching the crest and being pushed over to the landward side is then transported seaward by occasionally dominating ebb currents there. Storm events, having generally an erosive effect on the shoreface, tend to increase the amplitude of the shoreface connected ridges, i.e. amplify the morphodynamic feedback mechanisms. Recovery of the seabed after ordinary winter storms occurs in time scales less than a month. Hence, the ridge maintenance seems to be controlled by the fair-weather tidal currents that are competent to transport fine to medium sands during a considerable part of the tidal cycle. The suggested sediment transport circulation mechanism is consistent with the long term stability of the shoreface connected ridges as well as high sediment mobility on the seabed. References Antia, E.E., Flemming, B.W. and Wefer, G. 1995. Calm-weather spring and neap tidal current characteristics on a shoreface-connected ridge complex in the German Bight, southern North Sea. Geo-Marine Letters 15, 30-36. Flemming, B.W. and Davis, R.A. Jr. 1994. Holocene Evolution, Morphodynamics and Sedimentology of the Spiekeroog Barrier Island System (Southern North Sea). Senckenbergiana maritima 24, 117-155.

  6. Modular system for assessment of glycosyl hydrolase secretion in Geobacillus thermoglucosidasius.

    PubMed

    Bartosiak-Jentys, Jeremy; Hussein, Ali H; Lewis, Claire J; Leak, David J

    2013-07-01

    The facultatively anaerobic, thermophilic bacterium Geobacillus thermoglucosidasius is being developed as an industrial micro-organism for cellulosic bioethanol production. Process improvement would be gained by enhanced secretion of glycosyl hydrolases. Here we report the construction of a modular system for combining promoters, signal peptide encoding regions and glycosyl hydrolase genes to facilitate selection of the optimal combination in G. thermoglucosidasius. Initially, a minimal three-part E. coli-Geobacillus sp. shuttle vector pUCG3.8 was constructed using Gibson isothermal DNA assembly. The three PCR amplicons contained the pMB1 E. coli origin of replication and multiple cloning site (MCS) of pUC18, the Geobacillus sp. origin of replication pBST1 and the thermostable kanamycin nucleotidyltransferase gene (knt), respectively. G. thermoglucosidasius could be transformed with pUCG3.8 at an increased efficiency [2.8×10(5) c.f.u. (µg DNA)(-1)] compared to a previously reported shuttle vector, pUCG18. A modular cassette for the inducible expression and secretion of proteins in G. thermoglucosidasius, designed to allow the simple interchange of parts, was demonstrated using the endoglucanase Cel5A from Thermotoga maritima as a secretion target. Expression of cel5A was placed under the control of a cellobiose-inducible promoter (P?glu) together with a signal peptide encoding sequence from a G. thermoglucosidasius C56-YS93 endo-?-1,4-xylanase. The interchange of parts was demonstrated by exchanging the cel5A gene with the 3' region of a gene with homology to celA from Caldicellulosiruptor saccharolyticus and substituting P?glu for the synthetic, constitutive promoter PUp2n38, which increased Cel5A activity five-fold. Cel5A and CelA activities were detected in culture supernatants indicating successful expression and secretion. N-terminal protein sequencing of Cel5A carrying a C-terminal FLAG epitope confirmed processing of the signal peptide sequence. PMID:23704786

  7. Where on Earth...? MISR Mystery Image Quiz #6

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Here's another chance to play geographical detective! This Multi-angle Imaging SpectroRadiometer (MISR) image covers an area of about 298 kilometers x 358 kilometers, and was captured by the instrument's vertical-viewing (nadir) camera on December 27, 2001. Use any reference materials you like and answer the following five questions: The large lagoon in the image is named for a particular type of bird. Name the bird. Note the sediment plume emanating from the southern end of the lagoon. Sailors in the 16th century imagined this outlet to be the mouth of a large river. What did they call the river? A series of wave-like points and curls form 'cusps' on the inner shores of the lagoon. Which ONE of the following is most responsible for the formation of these cusps? Violent storm impacts on erosion and accretion Wind and tide-driven sediment transport and circulation Tectonic folding associated with nearby mountain ridges Bathymetric effects of dredging operations True or false: Changes in regional precipitation associated with large scale atmospheric circulation patterns have no effect on the salinity of the lagoon's water. Which one of these is NOT distributed within the area covered by this image? Ruppia maritima Chelonia mydas Tapirus bairdii Microcystis aeruginosa E-mail your answers, name (initials are acceptable if you prefer), and your hometown by Tuesday, February 19, 2002 to suggestions@mail-misr.jpl.nasa.gov. Answers will be published on the MISR web site in conjunction with the next weekly image release. The names and home towns of respondents who answer all questions correctly by the deadline will also be published in the order responses were received. The first 3 people on this list who are not affiliated with NASA, JPL, or MISR and who did not win a prize in the last quiz will be sent a print of the image. A new 'Where on Earth...?' mystery appears as the MISR 'image of the week' approximately once per month. A new image of the week is released every Wednesday at noon Pacific time on the MISR home page http://www-misr.jpl.nasa.gov. The image also appears on the Atmospheric Sciences Data Center home page, http://eosweb.larc.nasa.gov, though usually with a several-hour delay. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team.

  8. On the origin and evolution of thermophily: reconstruction of functional precambrian enzymes from ancestors of Bacillus.

    PubMed

    Hobbs, Joanne K; Shepherd, Charis; Saul, David J; Demetras, Nicholas J; Haaning, Svend; Monk, Colin R; Daniel, Roy M; Arcus, Vickery L

    2012-02-01

    Thermophily is thought to be a primitive trait, characteristic of early forms of life on Earth, that has been gradually lost over evolutionary time. The genus Bacillus provides an ideal model for studying the evolution of thermophily as it is an ancient taxon and its contemporary species inhabit a range of thermal environments. The thermostability of reconstructed ancestral proteins has been used as a proxy for ancient thermal adaptation. The reconstruction of ancestral "enzymes" has the added advantages of demonstrable activity, which acts as an internal control for accurate inference, and providing insights into the evolution of enzymatic catalysis. Here, we report the reconstruction of the structurally complex core metabolic enzyme LeuB (3-isopropylmalate dehydrogenase, E. C. 1.1.1.85) from the last common ancestor (LCA) of Bacillus using both maximum likelihood (ML) and Bayesian inference. ML LeuB from the LCA of Bacillus shares only 76% sequence identity with its closest contemporary homolog, yet it is fully functional, thermophilic, and exhibits high values for k(cat), k(cat)/K(M), and ?G(‡) for unfolding. The Bayesian version of this enzyme is also thermophilic but exhibits anomalous catalytic kinetics. We have determined the 3D structure of the ML enzyme and found that it is more closely aligned with LeuB from deeply branching bacteria, such as Thermotoga maritima, than contemporary Bacillus species. To investigate the evolution of thermophily, three descendents of LeuB from the LCA of Bacillus were also reconstructed. They reveal a fluctuating trend in thermal evolution, with a temporal adaptation toward mesophily followed by a more recent return to thermophily. Structural analysis suggests that the determinants of thermophily in LeuB from the LCA of Bacillus and the most recent ancestor are distinct and that thermophily has arisen in this genus at least twice via independent evolutionary paths. Our results add significant fluctuations to the broad trend in thermal adaptation previously proposed and demonstrate that thermophily is not exclusively a primitive trait, as it can be readily gained as well as lost. Our findings also demonstrate that reconstruction of complex functional Precambrian enzymes is possible and can provide empirical access to the evolution of ancient phenotypes and metabolisms. PMID:21998276

  9. Selenium removal and mass balance in a constructed flow-through wetland system.

    PubMed

    Gao, S; Tanji, K K; Lin, Z Q; Terry, N; Peters, D W

    2003-01-01

    A field study on the removal of Se from agricultural subsurface drainage was conducted from May 1997 to February 2001 in the Tulare Lake Drainage District (TLDD) of San Joaquin Valley, California. A flow-through wetland system was constructed consisting of ten 15- x 76-m unlined cells that were continuously flooded and planted with either a monotype or combination of plants, including sturdy bulrush [Schoenoplectus robustus (Pursh) M.T. Strong], baltic rush (Juncus balticus Willd.), smooth cordgrass (Spartina alterniflora Loisel.), rabbitsfoot grass [Polypogon monspeliensis (L.) Desf.], salt-grass lDistichlis spicata (L.) Greene], cattail (Typha latifolia L.), tule [Schoenoplectus acutus (Muhl. ex Bigelow) A. Löve & D. Löve], and widgeon grass (Ruppia maritima L.). One cell had no vegetation planted. The objectives of this research were to evaluate Se removal efficiency of each wetland cell and to carry out a mass balance on Se. The inflow drainage water to the cells had average annual Se concentrations of 19 to 22 microg L(-1) dominated by selenate [Se(VI), 95%]. Average weekly water residence time varied from about 3 to 15 d for Cells 1 through 7 (target 7 d), 19 to 33 d for Cells 8 and 9 (target 21 d), and 13 to 18 d for Cell 10 (target 14 d). Average weekly Se concentration ratios of outflow to inflow ranged from 0.45 to 0.79 and mass ratio (concentration x water volume) from 0.24 to 0.52 for year 2000, that is, 21 to 55% reduction in Se concentration and 48 to 76% Se removal in mass by the wetland, respectively. The nonvegetated cell showed the least Se removal both in concentration and in mass. The global mass balance showed that on the average about 59% of the total inflow Se was retained within the cells and Se outputs were outflow (35%), seepage (4%), and volatilization (2%). Independent measurements of the Se retained in the cells totaled 53% of the total Se inflow: 33% in the surface (0-20 cm) sediment, 18% in the organic detrital layer above the sediment, 2% in the fallen litter, < 1% in the standing plants, and < 1% in the surface water. Thus, about 6% of the total Se inflow was unaccounted for in the internal compartments. PMID:12931913

  10. Response of biotic communities to salinity changes in a Mediterranean hypersaline stream

    PubMed Central

    Velasco, Josefa; Millán, Andrés; Hernández, Juan; Gutiérrez, Cayetano; Abellán, Pedro; Sánchez, David; Ruiz, Mar

    2006-01-01

    Background This study investigates the relationship between salinity and biotic communities (primary producers and macroinvertebrates) in Rambla Salada, a Mediterranean hypersaline stream in SE Spain. Since the 1980's, the mean salinity of the stream has fallen from about 100 g L-1 to 35.5 g L-1, due to intensive irrigated agriculture in the watershed. Furthermore, large dilutions occur occasionally when the water irrigation channel suffers cracks. Results Along the salinity gradient studied (3.5 – 76.4 g L-1) Cladophora glomerata and Ruppia maritima biomass decreased with increasing salinity, while the biomass of epipelic algae increased. Diptera and Coleoptera species dominated the community both in disturbed as in re-established conditions. Most macroinvertebrates species found in Rambla Salada stream are euryhaline species with a broad range of salinity tolerance. Eight of them were recorded in natural hypersaline conditions (~100 g L-1) prior to important change in land use of the watershed: Ephydra flavipes, Stratyomis longicornis, Nebrioporus ceresyi, N. baeticus, Berosus hispanicus, Enochrus falcarius, Ochthebius cuprescens and Sigara selecta. However, other species recorded in the past, such as Ochthebius glaber, O. notabilis and Enochrus politus, were restricted to a hypersaline source or absent from Rambla Salada. The dilution of salinity to 3.5 – 6.8 gL-1 allowed the colonization of species with low salininty tolerance, such as Melanopsis praemorsa, Anax sp., Simulidae, Ceratopogonidae and Tanypodinae. The abundance of Ephydra flavipes and Ochthebius corrugatus showed a positive significant response to salinity, while Anax sp., Simulidae, S. selecta, N. ceresyi, N. baeticus, and B. hispanicus showed significant negative correlations. The number of total macroinvertebrate taxa, Diptera and Coleoptera species, number of families, Margalef's index and Shannon's diversity index decreased with increasing salinity. However, the rest of community parameters, such as the abundance of individuals, evenness and Simpson's index, showed no significant response to changes in salinity. Classification and ordination analysis revealed major differences in macroinvertebrate community structure between hypersaline conditions (76.4 g L-1) and the rest of the communities observed at the lower salinity levels, and revealed that below ~75 g L-1, dissimilarities in the communities were greater between the two habitats studied (runs and pools) than between salinity levels. Conclusion Salinity was the first factor determining community composition and structure in Rambla Salada stream followed by the type of habitat. PMID:17014701

  11. A survey of green plant tRNA 3'-end processing enzyme tRNase Zs, homologs of the candidate prostate cancer susceptibility protein ELAC2

    PubMed Central

    2011-01-01

    Background tRNase Z removes the 3'-trailer sequences from precursor tRNAs, which is an essential step preceding the addition of the CCA sequence. tRNase Z exists in the short (tRNase ZS) and long (tRNase ZL) forms. Based on the sequence characteristics, they can be divided into two major types: bacterial-type tRNase ZS and eukaryotic-type tRNase ZL, and one minor type, Thermotoga maritima (TM)-type tRNase ZS. The number of tRNase Zs is highly variable, with the largest number being identified experimentally in the flowering plant Arabidopsis thaliana. It is unknown whether multiple tRNase Zs found in A. thaliana is common to the plant kingdom. Also unknown is the extent of sequence and structural conservation among tRNase Zs from the plant kingdom. Results We report the identification and analysis of candidate tRNase Zs in 27 fully sequenced genomes of green plants, the great majority of which are flowering plants. It appears that green plants contain multiple distinct tRNase Zs predicted to reside in different subcellular compartments. Furthermore, while the bacterial-type tRNase ZSs are present only in basal land plants and green algae, the TM-type tRNase ZSs are widespread in green plants. The protein sequences of the TM-type tRNase ZSs identified in green plants are similar to those of the bacterial-type tRNase ZSs but have distinct features, including the TM-type flexible arm, the variant catalytic HEAT and HST motifs, and a lack of the PxKxRN motif involved in CCA anti-determination (inhibition of tRNase Z activity by CCA), which prevents tRNase Z cleavage of mature tRNAs. Examination of flowering plant chloroplast tRNA genes reveals that many of these genes encode partial CCA sequences. Based on our results and previous studies, we predict that the plant TM-type tRNase ZSs may not recognize the CCA sequence as an anti-determinant. Conclusions Our findings substantially expand the current repertoire of the TM-type tRNase ZSs and hint at the possibility that these proteins may have been selected for their ability to process chloroplast pre-tRNAs with whole or partial CCA sequences. Our results also support the coevolution of tRNase Zs and tRNA 3'-trailer sequences in plants. PMID:21781332

  12. Utilization of flavonoid compounds from bark and wood: a review.

    PubMed

    Yazaki, Yoshikazu

    2015-03-01

    Flavonoid compounds, which are extracted from bark and wood and used commercially, are flavan 3-ols as monomers and their polymers, which are called "condensed tannins". Reactions of the condensed tannins with formaldehyde are the basis for wood adhesives. In the late 1940s, tannin research for wood adhesives was begun and the world-first commercial use of wattle tannin from black wattle (Acacia mearnsii) bark as wood adhesives occurred in Australia in the 1960s. In addition, wattle tannin-based adhesives were further developed in South Africa and the uses of these adhesives have been continuing to date. The success of wattle tannin in wood adhesives is demonstrated by the collaboration of the ACIAR with the CAF in the early 1990s. Although radiata pine bark (Pinus radiata) could be a useful resource for the production of wood adhesives, three problems prevented its use in this application: low extractive yields from the bark, variable quality of the tannin extracts and excessive viscosity of the formulated tannin adhesives. In order to overcome these problems, various extraction methods have been proposed. Studies on tannin adhesives from bark of other pine species are also described. Furthermore, the use of the tannin in the bark without extraction is described as "bark adhesives" from radiata pine and black wattle. The use of radiata tannin without formaldehyde for moulded wood products is also described. Owing to the strong antioxidant activity of flavonoid compounds, bark extracts from French maritime pine (Pinus pinaster, synonym P. maritima) and radiata pine have been commercialized as nutritional supplements: Pycnogenol and Enzogenol, respectively. The background and the development of Pycnogenol and the basic difference in the preparation processes between Pycnogenol and Enzogenol are described. On the basis of the discovery that the SOSA value for wattle tannin is approximately 10 times that of extracts from pine bark supplements (Pycnogenol and Enzogenol), chemical, biochemical and clinical studies on wattle tannin were conducted. Results from these studies are outlined. Wattle tannin has been developed as a nutritional supplement and marketed as Acapolia in Japan. PMID:25924541

  13. High tides and rising seas: potential effects on estuarine waterbirds

    USGS Publications Warehouse

    Erwin, R.M.; Sanders, G.M.; Prosser, D.J.; Cahoon, D.R.

    2006-01-01

    Coastal waterbirds are vulnerable to water-level changes especially under predictions of accelerating sea-level rise and increased storm frequency in the next century. Tidal and wind-driven fluctuations in water levels affecting marshes, their invertebrate communities, and their dependent waterbirds are manifested in daily, monthly, seasonal, annual, and supra-annual (e.g., decadal or 18.6-yr) periodicities. Superimposed on these cyclic patterns is a long-term (50?80 yr) increase in relative sea-level rise that varies from about 2?4 + mm/yr along the Atlantic coastline. At five study sites selected on marsh islands from Cape Cod, Massachusetts to coastal Virginia, we monitored marsh elevation changes and flooding, tide variations over time, and waterbird use. We found from longterm marsh core data that marsh elevations at three of five sites may not be sufficient to maintain pace with current sea-level rise. Results of the short-term (3?4 yr) measures using surface elevation tables suggest a more dramatic difference, with marsh elevation change at four of five sites falling below relative sea-level rise. In addition, we have found a significant increase (in three of four cases) in the rate of surface marsh flooding in New Jersey and Virginia over the past 70?80 yr during May?July when waterbirds are nesting on or near the marsh surface. Short-term, immediate effects of flooding will jeopardize annual fecundity of many species of concern to federal and state agencies, most notably American Black Duck (Anas rubripes), Nelson?s Sharp-tailed Sparrow (Ammodramus nelsoni), Saltmarsh Sharp-tailed Sparrow (A. caudacutus), Seaside Sparrow (A. maritima), Coastal Plain Swamp Sparrow (Melospiza georgiana nigrescens), Black Rail (Laterallus jamaicensis), Forster?s Tern (Sterna forsteri), Gull-billed Tern (S. nilotica), Black Skimmer (Rynchops niger), and American Oystercatcher (Haemotopus palliatus). Forster?s Terns are probably most at risk given the large proportion of their breeding range in the mid-Atlantic and their saltmarsh specialization. At a scale of 1?2 decades, vegetation changes (saltmeadow cordgrass [Spartina patens] and salt grass [Distichlis spicata] converting to smooth cordgrass [Spartina alternifl ora]), interior pond expansion and erosion of marshes will reduce nesting habitat for many of these species, but may enhance feeding habitat of migrant shorebirds and/or migrant or wintering waterfowl. At scales of 50?100 yr, reversion of marsh island complexes to open water may enhance populations of open-bay waterfowl, e.g., Bufflehead (Bucephala albeola) and Canvasback (Aythya valisneria), but reduce nesting habitats dramatically for the above named marsh-nesting species, may reduce estuarine productivity by loss of the detrital food web and nursery habitat for fish and invertebrates, and cause redistribution of waterfowl, shorebirds, and other species. Such scenarios are more likely to occur in the mid- and north Atlantic regions since these estuaries are lower in sediment delivery on average than those in the Southeast. A simple hypothetical example from New Jersey is presented where waterbirds are forced to shift from submerged natural marshes to nearby impoundments, resulting in roughly a 10-fold increase in density. Whether prey fauna are sufficiently abundant to support this level of increase remains an open question, but extreme densities in confined habitats would exacerbate competition, increase disease risk, and possibly increase predation.