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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 Central

    Al-Dosary, Mona Mohammed

    2009-01-01

    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. 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

  3. Management strategies in apple orchards influence earwig community.

    PubMed

    Malagnoux, Laure; Marliac, Gaëlle; Simon, Sylvaine; Rault, Magali; Capowiez, Yvan

    2015-04-01

    Our aim was to assess whether different apple orchard management strategies (low-input, organic, Integrated Pest Management (IPM)) would have an effect on earwigs, which are important natural enemies of apple pests. These commercial orchards were as well compared to abandoned orchards. The density of Forficula auricularia and Forficula pubescens was studied for three years in 74 orchards around Avignon. The pesticide usage, some orchard characteristics and two small-scale landscape parameters were characterized. Pesticide use was significantly different between low-input, organic and IPM orchards with particularly significant differences in the number of insecticide applications (2.2, 4.9 and 9.2 respectively). Pesticide use had a much stronger impact on earwig community than other characteristics. F. auricularia density was significantly lower in IPM orchards (0.47 individuals per tree) compared to organic, low-input and abandoned orchards (3.1, 4.5 and 1.6 individuals per tree, respectively). F. pubescens was almost absent from IPM orchards and its abundance was higher in abandoned or low-input orchards compared to organic orchards (1.5 and 2.8 vs 0.8 individuals per tree). The percentage of F. pubescens in the earwig community decreased from abandoned (52%) to low-input (40%), organic (15%) and IPM orchards (0.5%). These results were confirmed by LD50 assays showing that for the two pesticides causing mortality close to normal application rates (chlorpyrifos-ethyl and acetamiprid), F. pubescens was significantly more sensitive than F. auricularia. Since earwigs are also easy to capture and identify, they may be useful to estimate the effects of management strategies and their modification in pome fruit orchards. PMID:25577700

  4. Management strategies in apple orchards influence earwig community.

    PubMed

    Malagnoux, Laure; Marliac, Gaëlle; Simon, Sylvaine; Rault, Magali; Capowiez, Yvan

    2015-04-01

    Our aim was to assess whether different apple orchard management strategies (low-input, organic, Integrated Pest Management (IPM)) would have an effect on earwigs, which are important natural enemies of apple pests. These commercial orchards were as well compared to abandoned orchards. The density of Forficula auricularia and Forficula pubescens was studied for three years in 74 orchards around Avignon. The pesticide usage, some orchard characteristics and two small-scale landscape parameters were characterized. Pesticide use was significantly different between low-input, organic and IPM orchards with particularly significant differences in the number of insecticide applications (2.2, 4.9 and 9.2 respectively). Pesticide use had a much stronger impact on earwig community than other characteristics. F. auricularia density was significantly lower in IPM orchards (0.47 individuals per tree) compared to organic, low-input and abandoned orchards (3.1, 4.5 and 1.6 individuals per tree, respectively). F. pubescens was almost absent from IPM orchards and its abundance was higher in abandoned or low-input orchards compared to organic orchards (1.5 and 2.8 vs 0.8 individuals per tree). The percentage of F. pubescens in the earwig community decreased from abandoned (52%) to low-input (40%), organic (15%) and IPM orchards (0.5%). These results were confirmed by LD50 assays showing that for the two pesticides causing mortality close to normal application rates (chlorpyrifos-ethyl and acetamiprid), F. pubescens was significantly more sensitive than F. auricularia. Since earwigs are also easy to capture and identify, they may be useful to estimate the effects of management strategies and their modification in pome fruit orchards.

  5. 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.

  6. Reassessing the phylogenetic position of the epizoic earwigs (Insecta: Dermaptera).

    PubMed

    Naegle, Michael A; Mugleston, Joseph D; Bybee, Seth M; Whiting, Michael F

    2016-07-01

    Dermaptera is a relatively small order of free-living insects that typically feed on detritus and other plant material. However, two earwig lineages - Arixeniidae and Hemimeridae - are epizoic on Cheiromeles bats and Beamys and Cricetomys rats respectively. Both of these epizoic families are comprised of viviparous species. The monophyly of these epizoic lineages and their placement within dermapteran phylogeny has remained unclear. A phylogenetic analyses was performed on a diverse sample of 47 earwig taxa for five loci (18S rDNA, 28S rDNA, COI, Histone 3, and Tubulin Alpha I). Our results support two independent origins of the epizoic lifestyle within Dermaptera, with Hemimeridae and Arixeniidae each derived from a different lineage of Spongiphoridae. Our analyses places Marava, a genus of spongiphorids that includes free-living but viviparous earwigs, as sister group to Arixeniidae, suggesting that viviparity evolved prior to the shift to the epizoic lifestyle. Additionally, our results support the monophyly of Forficulidae and Chelisochidae and the paraphyly of Labiduridae, Pygidicranidae, Spongiphoridae, and Anisolabididae. PMID:27033951

  7. European Earwig, Forficula auricularia L. (Dermaptera: Forficulidae) at the Hanford Reach National Monument, Washington State

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The European earwig, Forficula auricularia L., was surveyed using pitfall traps at three sites at the Hanford Reach National Monument in south central Washington state. Pitfall traps were collected weekly from April 2002 through April 2003. The earwig was consistently taken during all months of the...

  8. Contact Toxicity and Residual Efficacy of Indoxacarb against the European Earwig (Dermaptera: Forficulidae)

    PubMed Central

    Jones, Susan C.; Bryant, Joshua L.

    2012-01-01

    Indoxacarb (Arilon 20WG) was evaluated against a nuisance pest, the European earwig (Forficula auricularia), and was found to be an effective contact toxicant with residual activity on substrates commonly encountered in urban environments. Within 16 h of being directly sprayed with indoxacarb, ≥90% of earwigs from two populations were either ataxic, moribund, or dead, and 100% displayed these symptoms of severe intoxication at 1 d. Brief exposure (5 min or 1 h) to dried residues on either a porous (pine wood) or non-porous (ceramic tile) substrate also was sufficient to cause severe intoxication of earwigs within 1 d. In all bioassays, indoxacarb-treated earwigs showed no signs of recovery during the 21-d observation period. In outdoor urban habitats, intoxicated earwigs would be more vulnerable to desiccation, predation, or pathogens leading to higher mortality than in a laboratory setting. PMID:26466616

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

    NASA Astrophysics Data System (ADS)

    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.

  10. 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

  11. Dihydrodipicolinate synthase from Thermotoga maritima.

    PubMed

    Pearce, F Grant; Perugini, Matthew A; McKerchar, Hannah J; Gerrard, Juliet A

    2006-12-01

    DHDPS (dihydrodipicolinate synthase) catalyses the branch point in lysine biosynthesis in bacteria and plants and is feedback inhibited by lysine. DHDPS from the thermophilic bacterium Thermotoga maritima shows a high level of heat and chemical stability. When incubated at 90 degrees C or in 8 M urea, the enzyme showed little or no loss of activity, unlike the Escherichia coli enzyme. The active site is very similar to that of the E. coli enzyme, and at mesophilic temperatures the two enzymes have similar kinetic constants. Like other forms of the enzyme, T. maritima DHDPS is a tetramer in solution, with a sedimentation coefficient of 7.2 S and molar mass of 133 kDa. However, the residues involved in the interface between different subunits in the tetramer differ from those of E. coli and include two cysteine residues poised to form a disulfide bond. Thus the increased heat and chemical stability of the T. maritima DHDPS enzyme is, at least in part, explained by an increased number of inter-subunit contacts. Unlike the plant or E. coli enzyme, the thermophilic DHDPS enzyme is not inhibited by (S)-lysine, suggesting that feedback control of the lysine biosynthetic pathway evolved later in the bacterial lineage. PMID:16872276

  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. Impact of insecticide exposure on the predation activity of the European earwig Forficula auricularia.

    PubMed

    Malagnoux, Laure; Capowiez, Yvan; Rault, Magali

    2015-09-01

    The European earwig Forficula auricularia is an effective predator in apple orchards. It is therefore crucial to study whether insecticides affect this natural pest control agent. Predation activity, i.e., the number of aphids eaten in 24 h, was determined under laboratory conditions after exposure of fourth-instar nymphs and adult earwigs to widely used insecticides (acetamiprid, chlorpyrifos-ethyl, deltamethrin, and spinosad), which were applied at the normal application rates. Inhibition of acetylcholinesterase and carboxylesterase activities were also measured as indicators of pesticide exposure. Predation activity decreased significantly in nymphs exposed to spinosad (62%) and chlorpyrifos-ethyl (98%) compared with controls. A similar response was found for both esterase activities. Spinosad had a stronger effect on AChE (-33%) whereas chlorpyrifos-ethyl affected CbE activity preferentially (-59%). Spinosad (20% of controls), acetamiprid (28%), and chlorpyrifos-ethyl (66%) also significantly decreased the predation behavior of adult male but not female (5 to 40%) earwigs. Adult AChE and CbE activities were also significantly reduced (28 to 67% of controls) in pesticide-exposed earwigs. Our results suggest that earwigs should be included in the environmental risk assessment framework for authorization of newly marketed plant protection products. Their predation behavior appears to be a sensitive and complementary biomarker. PMID:25963069

  14. Impact of insecticide exposure on the predation activity of the European earwig Forficula auricularia.

    PubMed

    Malagnoux, Laure; Capowiez, Yvan; Rault, Magali

    2015-09-01

    The European earwig Forficula auricularia is an effective predator in apple orchards. It is therefore crucial to study whether insecticides affect this natural pest control agent. Predation activity, i.e., the number of aphids eaten in 24 h, was determined under laboratory conditions after exposure of fourth-instar nymphs and adult earwigs to widely used insecticides (acetamiprid, chlorpyrifos-ethyl, deltamethrin, and spinosad), which were applied at the normal application rates. Inhibition of acetylcholinesterase and carboxylesterase activities were also measured as indicators of pesticide exposure. Predation activity decreased significantly in nymphs exposed to spinosad (62%) and chlorpyrifos-ethyl (98%) compared with controls. A similar response was found for both esterase activities. Spinosad had a stronger effect on AChE (-33%) whereas chlorpyrifos-ethyl affected CbE activity preferentially (-59%). Spinosad (20% of controls), acetamiprid (28%), and chlorpyrifos-ethyl (66%) also significantly decreased the predation behavior of adult male but not female (5 to 40%) earwigs. Adult AChE and CbE activities were also significantly reduced (28 to 67% of controls) in pesticide-exposed earwigs. Our results suggest that earwigs should be included in the environmental risk assessment framework for authorization of newly marketed plant protection products. Their predation behavior appears to be a sensitive and complementary biomarker.

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

    PubMed

    Engel, Michael S

    2011-01-01

    Two new earwigs (Dermaptera) recently discovered in mid-Cretaceous (latest Albian) amber from Myanmar are described and figured. Astreptolabis ethirosomatiagen. et sp. n. is represented by a peculiar pygidicranoid female, assigned to a new subfamily, Astreptolabidinaesubfam. n., and differs from other protodermapterans in the structure of the head, pronotum, tegmina, and cercal forceps. Tytthodiplatys mecynocercusgen. et sp. n. is a distinctive form of first-instar nymph of the Diplatyidae, the earliest record for this basal earwig family. The taxon can be distinguished from other Early Cretaceous nymphs by the structure of the head, antennae, legs, and most notably its filamentous and annulate cerci. The character affinities of these taxa among Neodermaptera are generally discussed as is the identity of an enigmatic 'earwig-like' species from the Jurassic of China.

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

    PubMed Central

    Engel, Michael S.

    2011-01-01

    Abstract Two new earwigs (Dermaptera) recently discovered in mid-Cretaceous (latest Albian) amber from Myanmar are described and figured. Astreptolabis ethirosomatia gen. et sp. n. is represented by a peculiar pygidicranoid female, assigned to a new 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, the earliest record for this basal earwig family. The taxon can be distinguished from other Early Cretaceous nymphs by the structure of the head, antennae, legs, and most notably its filamentous and annulate cerci. The character affinities of these taxa among Neodermaptera are generally discussed as is the identity of an enigmatic ‘earwig-like’ species from the Jurassic of China. PMID:22259272

  17. Simultaneous optimisation of earwig hindwings for flight and folding.

    PubMed

    Deiters, Julia; Kowalczyk, Wojciech; Seidl, Tobias

    2016-01-01

    Earwig wings are highly foldable structures that lack internal muscles. The behaviour and shape changes of the wings during flight are yet unknown. We assume that they meet a great structural challenge to control the occurring deformations and prevent the wing from collapsing. At the folding structures especially, the wing could easily yield to the pressure. Detailed microscopy studies reveal adaptions in the structure and material which are not relevant for folding purposes. The wing is parted into two structurally different areas with, for example, a different trend or stiffness of the wing veins. The storage of stiff or more flexible material shows critical areas which undergo great changes or stress during flight. We verified this with high-speed video recordings. These reveal the extent of the occurring deformations and their locations, and support our assumptions. The video recordings reveal a dynamical change of a concave flexion line. In the static unfolded state, this flexion line blocks a folding line, so that the wing stays unfolded. However, during flight it extends and blocks a second critical folding line and prevents the wing from collapsing. With these results, more insight in passive wing control, especially within high foldable structures, is gained. PMID:27113958

  18. Simultaneous optimisation of earwig hindwings for flight and folding.

    PubMed

    Deiters, Julia; Kowalczyk, Wojciech; Seidl, Tobias

    2016-01-01

    Earwig wings are highly foldable structures that lack internal muscles. The behaviour and shape changes of the wings during flight are yet unknown. We assume that they meet a great structural challenge to control the occurring deformations and prevent the wing from collapsing. At the folding structures especially, the wing could easily yield to the pressure. Detailed microscopy studies reveal adaptions in the structure and material which are not relevant for folding purposes. The wing is parted into two structurally different areas with, for example, a different trend or stiffness of the wing veins. The storage of stiff or more flexible material shows critical areas which undergo great changes or stress during flight. We verified this with high-speed video recordings. These reveal the extent of the occurring deformations and their locations, and support our assumptions. The video recordings reveal a dynamical change of a concave flexion line. In the static unfolded state, this flexion line blocks a folding line, so that the wing stays unfolded. However, during flight it extends and blocks a second critical folding line and prevents the wing from collapsing. With these results, more insight in passive wing control, especially within high foldable structures, is gained.

  19. 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

  20. Simultaneous optimisation of earwig hindwings for flight and folding

    PubMed Central

    Deiters, Julia; Kowalczyk, Wojciech; Seidl, Tobias

    2016-01-01

    ABSTRACT Earwig wings are highly foldable structures that lack internal muscles. The behaviour and shape changes of the wings during flight are yet unknown. We assume that they meet a great structural challenge to control the occurring deformations and prevent the wing from collapsing. At the folding structures especially, the wing could easily yield to the pressure. Detailed microscopy studies reveal adaptions in the structure and material which are not relevant for folding purposes. The wing is parted into two structurally different areas with, for example, a different trend or stiffness of the wing veins. The storage of stiff or more flexible material shows critical areas which undergo great changes or stress during flight. We verified this with high-speed video recordings. These reveal the extent of the occurring deformations and their locations, and support our assumptions. The video recordings reveal a dynamical change of a concave flexion line. In the static unfolded state, this flexion line blocks a folding line, so that the wing stays unfolded. However, during flight it extends and blocks a second critical folding line and prevents the wing from collapsing. With these results, more insight in passive wing control, especially within high foldable structures, is gained. PMID:27113958

  1. Tissue distribution, characterization and in vitro inhibition of B-esterases in the earwig Forficula auricularia.

    PubMed

    Malagnoux, Laure; Capowiez, Yvan; Rault, Magali

    2014-10-01

    Earwigs are important natural enemies of numerous pests in pome fruit orchards worldwide. Studying the effects of agricultural practices on these biological control agents is important for understanding its vulnerability in the field. The aim of this study was to characterize the B-esterase activities in the European earwig Forficula auricularia and to evaluate in vitro its sensitivity to organophosphate and carbamate pesticides. Acetylcholinesterase (AChE) activity was mainly measured with 1.5 mM acetylthiocholine as the substrate in the microsomal fraction of earwig heads (70% of total AChE activity). Carboxylesterase (CbE) activities were measured with three substrates [5 mM 4-nitrophenyl acetate (4-NPA), 1mM 4-nitrophenyl valerate (4-NPV), and 2 mM α-naphtyl acetate (α-NA)] to examine different isoenzymes, which were present mainly in the cytosolic fraction (about 70-88% of total activities) of all earwig tissues. CbE activity was higher than AChE activity, especially with α-NA, then 4-NPA and lastly 4-NPV. Chlorpyrifos-oxon an organophosphate, and carbaryl a carbamate pesticide, inhibited AChE and CbE activities in a concentration-dependent manner. Earwig CbE activities showed a stronger sensitivity to organophosphate than AChE, with the strongest effect for chlorpyrifos-oxon on male carboxylesterase activities. CbE and AChE showed about the same sensitivity to carbamate pesticides regardless of sex. These results suggest that B-type esterases in the European earwig F.auricularia are suitable biomarkers of pesticide exposure.

  2. A "spare" compensates for the risk of destruction of the elongated penis of earwigs (Insecta: Dermaptera)

    NASA Astrophysics Data System (ADS)

    Kamimura, Yoshitaka; Matsuo, Yoh

    2001-11-01

    Male animals in several groups have multiple intromittent organs that outnumber the corresponding female gonopore. In Dermaptera (earwigs), males of the family Anisolabididae have paired, elongated male intromittent organs (virgae), while females have a single sperm-storage organ (spermatheca). Several authors have assumed that one of the paired virgae is non-functional, because it points in the "wrong" direction. We investigated the mating success of handicapped males of Euborellia plebeja in which one of their paired virgae was removed experimentally. These handicapped males succeeded in inseminating a mate. Males with genital damage are found in the field, suggesting that the "spare" functions under natural conditions. Based on phylogenetic information on earwigs, we discuss possible evolutionary scenarios for this genital peculiarity.

  3. When the body hides the ancestry: phylogeny of morphologically modified epizoic earwigs based on molecular evidence.

    PubMed

    Kocarek, Petr; John, Vaclav; Hulva, Pavel

    2013-01-01

    Here, we present a study regarding the phylogenetic positions of two enigmatic earwig lineages whose unique phenotypic traits evolved in connection with ectoparasitic relationships with mammals. Extant earwigs (Dermaptera) have traditionally been divided into three suborders: the Hemimerina, Arixeniina, and Forficulina. While the Forficulina are typical, well-known, free-living earwigs, the Hemimerina and Arixeniina are unusual epizoic groups living on molossid bats (Arixeniina) or murid rodents (Hemimerina). The monophyly of both epizoic lineages is well established, but their relationship to the remainder of the Dermaptera is controversial because of their extremely modified morphology with paedomorphic features. We present phylogenetic analyses that include molecular data (18S and 28S ribosomal DNA and histone-3) for both Arixeniina and Hemimerina for the first time. This data set enabled us to apply a rigorous cladistics approach and to test competing hypotheses that were previously scattered in the literature. Our results demonstrate that Arixeniidae and Hemimeridae belong in the dermapteran suborder Neodermaptera, infraorder Epidermaptera, and superfamily Forficuloidea. The results support the sister group relationships of Arixeniidae+Chelisochidae and Hemimeridae+Forficulidae. This study demonstrates the potential for rapid and substantial macroevolutionary changes at the morphological level as related to adaptive evolution, in this case linked to the utilization of a novel trophic niche based on an epizoic life strategy. Our results also indicate that the evolutionary consequences of the transition to an ectoparazitic mode of living, which is extremely rare in earwigs, have biased previous morphology-based hypotheses regarding the phylogeny of this insect group. PMID:23826171

  4. Novel inositol catabolic pathway in Thermotoga maritima.

    PubMed

    Rodionova, Irina A; Leyn, Semen A; Burkart, Michael D; Boucher, Nathalie; Noll, Kenneth M; Osterman, Andrei L; Rodionov, Dmitry A

    2013-08-01

    myo-inositol (MI) is a key sugar alcohol component of various metabolites, e.g. phosphatidylinositol-based phospholipids that are abundant in animal and plant cells. The seven-step pathway of MI degradation was previously characterized in various soil bacteria including Bacillus subtilis. Through a combination of bioinformatics and experimental techniques we identified a novel variant of the MI catabolic pathway in the marine hyperthermophilic bacterium Thermotoga maritima. By using in vitro biochemical assays with purified recombinant proteins we characterized four inositol catabolic enzymes encoded in the TM0412-TM0416 chromosomal gene cluster. The novel catabolic pathway in T. maritima starts as the conventional route using the myo-inositol dehydrogenase IolG followed by three novel reactions. The first 2-keto-myo-inositol intermediate is oxidized by another, previously unknown NAD-dependent dehydrogenase TM0412 (named IolM), and a yet unidentified product of this reaction is further hydrolysed by TM0413 (IolN) to form 5-keto-l-gluconate. The fourth step involves epimerization of 5-keto-l-gluconate to d-tagaturonate by TM0416 (IolO). T. maritima is unable to grow on myo-inositol as a single carbon source. The determined in vitro specificity of the InoEFGK (TM0418-TM0421) transporter to myo-inositol-phosphate suggests that the novel pathway in Thermotoga utilizes a phosphorylated derivative of inositol.

  5. 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.

  6. Spore dispersal of fetid Lysurus mokusin by feces of mycophagous insects.

    PubMed

    Chen, Gao; Zhang, Rui-Rui; Liu, Yang; Sun, Wei-Bang

    2014-08-01

    The ecological roles and biological mechanisms of zoochory in plants have long been foci in studies of co-evolutionary processes between plants and animals. However, the dispersal of fungal spores by animals has received comparatively little attention. In this study, the dispersal of spores of a selected fetid fungus, Lysurus mokusin, via feces of mycophagous insects was explored by: collecting volatiles emitted by the fungus using dynamic headspace extraction and analyzing them by GC-MS; testing the capacity of mycophagous insects to disperse its spores by counting spores in their feces; comparing the germinability of L. mokusin spores extracted from feces of nocturnal earwigs and natural gleba of the fungus; and assessing the ability of L. mokusin volatiles to attract insects in bioassays with synthetic scent mixtures. Numerous spores were detected in insects' feces, the bioassays indicated that L. mokusin odor (similar to that of decaying substances) attracts diverse generalist mycophagous insects, and passage through the gut of Anisolabis maritima earwigs significantly enhanced the germination rate of L. mokusin spores. Therefore, nocturnal earwigs and diurnal flies probably play important roles in dispersal of L. mokusin spores, and dispersal via feces may be an important common dispersal mechanism for fungal reproductive tissue.

  7. Spore dispersal of fetid Lysurus mokusin by feces of mycophagous insects.

    PubMed

    Chen, Gao; Zhang, Rui-Rui; Liu, Yang; Sun, Wei-Bang

    2014-08-01

    The ecological roles and biological mechanisms of zoochory in plants have long been foci in studies of co-evolutionary processes between plants and animals. However, the dispersal of fungal spores by animals has received comparatively little attention. In this study, the dispersal of spores of a selected fetid fungus, Lysurus mokusin, via feces of mycophagous insects was explored by: collecting volatiles emitted by the fungus using dynamic headspace extraction and analyzing them by GC-MS; testing the capacity of mycophagous insects to disperse its spores by counting spores in their feces; comparing the germinability of L. mokusin spores extracted from feces of nocturnal earwigs and natural gleba of the fungus; and assessing the ability of L. mokusin volatiles to attract insects in bioassays with synthetic scent mixtures. Numerous spores were detected in insects' feces, the bioassays indicated that L. mokusin odor (similar to that of decaying substances) attracts diverse generalist mycophagous insects, and passage through the gut of Anisolabis maritima earwigs significantly enhanced the germination rate of L. mokusin spores. Therefore, nocturnal earwigs and diurnal flies probably play important roles in dispersal of L. mokusin spores, and dispersal via feces may be an important common dispersal mechanism for fungal reproductive tissue. PMID:25064696

  8. 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

  9. The Complete Mitochondrial Genome of the Geophilomorph Centipede Strigamia maritima

    PubMed Central

    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

  10. 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

  11. Maternal care, mother-offspring aggregation and age-dependent coadaptation in the European earwig.

    PubMed

    Gómez, Y; Kölliker, M

    2013-09-01

    Benefits and costs of parental care are expected to change with offspring development and lead to age-dependent coadaptation expressed as phenotypic (behavioural) matches between offspring age and parental reproductive stage. Parents and offspring interact repeatedly over time for the provision of parental care. Their behaviours should be accordingly adjusted to each other dynamically and adaptively, and the phenotypic match between offspring age and parental stage should stabilize the repeated behavioural interactions. In the European earwig (Forficula auricularia), maternal care is beneficial for offspring survival, but not vital, allowing us to investigate the extent to which the stability of mother-offspring aggregation is shaped by age-dependent coadaptation. In this study, we experimentally cross-fostered nymphs of different age classes (younger or older) between females in early or late reproductive stage to disrupt age-dependent coadaptation, thereby generating female-nymph dyads that were phenotypically matched or mismatched. The results revealed a higher stability in aggregation during the first larval instar when care is most intense, a steeper decline in aggregation tendency over developmental time and a reduced developmental rate in matched compared with mismatched families. Furthermore, nymph survival was positively correlated with female-nymph aggregation stability during the early stages when maternal care is most prevalent. These results support the hypothesis that age-related phenotypically plastic coadaptation affects family dynamics and offspring developmental rate.

  12. Wigeongrass (Ruppia maritima): a literature review

    USGS Publications Warehouse

    Kantrud, Harold 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

  13. Transcriptional regulation of the carbohydrate utilization network in Thermotoga maritima

    PubMed Central

    Rodionov, Dmitry A.; Rodionova, Irina A.; Li, Xiaoqing; Ravcheev, Dmitry A.; Tarasova, Yekaterina; Portnoy, Vasiliy A.; Zengler, Karsten; Osterman, Andrei L.

    2013-01-01

    Hyperthermophilic bacteria from the Thermotogales lineage can produce hydrogen by fermenting a wide range of carbohydrates. Previous experimental studies identified a large fraction of genes committed to carbohydrate degradation and utilization in the model bacterium Thermotoga maritima. Knowledge of these genes enabled comprehensive reconstruction of biochemical pathways comprising the carbohydrate utilization network. However, transcriptional factors (TFs) and regulatory mechanisms driving this network remained largely unknown. Here, we used an integrated approach based on comparative analysis of genomic and transcriptomic data for the reconstruction of the carbohydrate utilization regulatory networks in 11 Thermotogales genomes. We identified DNA-binding motifs and regulons for 19 orthologous TFs in the Thermotogales. The inferred regulatory network in T. maritima contains 181 genes encoding TFs, sugar catabolic enzymes and ABC-family transporters. In contrast to many previously described bacteria, a transcriptional regulation strategy of Thermotoga does not employ global regulatory factors. The reconstructed regulatory network in T. maritima was validated by gene expression profiling on a panel of mono- and disaccharides and by in vitro DNA-binding assays. The observed upregulation of genes involved in catabolism of pectin, trehalose, cellobiose, arabinose, rhamnose, xylose, glucose, galactose, and ribose showed a strong correlation with the UxaR, TreR, BglR, CelR, AraR, RhaR, XylR, GluR, GalR, and RbsR regulons. Ultimately, this study elucidated the transcriptional regulatory network and mechanisms controlling expression of carbohydrate utilization genes in T. maritima. In addition to improving the functional annotations of associated transporters and catabolic enzymes, this research provides novel insights into the evolution of regulatory networks in Thermotogales. PMID:23986752

  14. The earwig fauna (Insecta: Dermaptera) of Penang Island, Malaysia, with descriptions of two new species.

    PubMed

    Kamimura, Yoshitaka; Nishikawa, Masaru; Lee, Chow-Yang

    2016-01-01

    The earwig (Dermaptera) fauna of Penang Island, Malaysia, was evaluated by means of an extensive field survey together with revision of the few published data. Based on the results of the field survey, 31 species are recognized (2 Diplatyidae, 3 Pygidicranidae, 5 Anisolabididae, 2 Labiduridae, 14 Spongiphoridae, 4 Chelisochidae, 1 Forficulidae). Fifteen of these taxa are new to Peninsular Malaysia (=West Malaysia): Diplatys annandalei Burr, 1911, Diplatys mutiara n. sp., Euborellia philippinensis Srivastava, 1979, Metisolabis punctata (Dubrony, 1879), Pseudovostox brindlei Srivastava, 2003, Chaetospania anderssoni Brindle, 1971, Chaetospania javana Borelli, 1926, Chaetospania huisiangi n. sp., Paralabellula boettcheri (Borelli, 1923), Paralabellula rotundifrons (Hincks, 1954), Nesogaster amoenus (Stål, 1855), Hamaxas crassus Borelli, 1926, Proreus coalescens (Borelli, 1927), Hypurgus humeralis (Kirby, 1891), and an unidentified Echinosoma sp. Species composition of the island are compared with the dermapteran fauna of Thailand. Descriptions of females (or female genitalia) are given for some species for the first time. PMID:27394261

  15. Description and biology of Euborellia arcanum sp. nov., an alien earwig occupying greenhouses in Germany and Austria (Dermaptera: Anisolabididae).

    PubMed

    Matzke, Danilo; Kocarek, Petr

    2015-01-01

    Greenhouses in botanical or zoological gardens are home to dozens of species of invertebrates that were introduced alongside plants or potting soil. Our study presents the description of an alien species of earwig, Euborellia arcanum sp. nov., found in tropical greenhouses in Leipzig and Potsdam (Germany) and in Vienna (Austria), including information about its biology in breeding culture. The species was most likely introduced into Europe by way of plants or plant matter from Florida, but the region of its natural habitat is unknown. The sequence of the mitochondrial gene cytochrome c oxidase subunit I (COI) was also evaluated and added to GenBank as a DNA barcode for further identification. PMID:26248909

  16. The earwig fauna (Insecta: Dermaptera) of Penang Island, Malaysia, with descriptions of two new species.

    PubMed

    Kamimura, Yoshitaka; Nishikawa, Masaru; Lee, Chow-Yang

    2016-02-25

    The earwig (Dermaptera) fauna of Penang Island, Malaysia, was evaluated by means of an extensive field survey together with revision of the few published data. Based on the results of the field survey, 31 species are recognized (2 Diplatyidae, 3 Pygidicranidae, 5 Anisolabididae, 2 Labiduridae, 14 Spongiphoridae, 4 Chelisochidae, 1 Forficulidae). Fifteen of these taxa are new to Peninsular Malaysia (=West Malaysia): Diplatys annandalei Burr, 1911, Diplatys mutiara n. sp., Euborellia philippinensis Srivastava, 1979, Metisolabis punctata (Dubrony, 1879), Pseudovostox brindlei Srivastava, 2003, Chaetospania anderssoni Brindle, 1971, Chaetospania javana Borelli, 1926, Chaetospania huisiangi n. sp., Paralabellula boettcheri (Borelli, 1923), Paralabellula rotundifrons (Hincks, 1954), Nesogaster amoenus (Stål, 1855), Hamaxas crassus Borelli, 1926, Proreus coalescens (Borelli, 1927), Hypurgus humeralis (Kirby, 1891), and an unidentified Echinosoma sp. Species composition of the island are compared with the dermapteran fauna of Thailand. Descriptions of females (or female genitalia) are given for some species for the first time.

  17. Characterization of the Earwig, Doru lineare, as a Predator of Larvae of the Fall Armyworm, Spodoptera frugiperda: A Functional Response Study

    PubMed Central

    Sueldo, Mabel Romero; Bruzzone, Octavio A.; Virla, Eduardo G.

    2010-01-01

    Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) is considered as the most important pest of maize in almost all tropical America. In Argentina, the earwig Doru lineare Eschscholtz (Dermaptera: Forficulidae) has been observed preying on S. frugiperda egg masses in corn crops, but no data about its potential role as a biocontrol agent of this pest have been provided. The predation efficiency of D. lineare on newly emerged S. frugiperda larva was evaluated through a laboratory functional response study. D. lineare showed type II functional response to S. frugiperda larval density, and disc equation estimations of searching efficiency and handling time were (a) = 0.374 and (t) = 182.9 s, respectively. Earwig satiation occurred at 39.4 S. frugiperda larvae. PMID:20575739

  18. Microsatellite marker development for the coastal dune shrub Prunus maritima (Rosaceae)1

    PubMed Central

    Badgley, Emily M.; Grubisha, Lisa C.; Roland, Anna K.; Connolly, Bryan A.; Klooster, Matthew R.

    2015-01-01

    • Premise of the study: Microsatellite primers were developed in the beach plum, Prunus maritima, to investigate the genetic composition of remaining populations in need of conservation and, in future studies, to determine its relation to P. maritima var. gravesii. • Methods and Results: Fourteen primer pairs were identified and tested in four populations throughout the species’ geographic range. Of these 14 loci, 12 were shown to be polymorphic among a total of 60 P. maritima individuals sampled (15 individuals sampled from four populations). Among the polymorphic loci, the number of alleles ranged from two to 10 and observed heterozygosity of loci ranged from 0.07 to 0.93 among specimens tested. • Conclusions: These microsatellites will be useful in evaluating the population genetic composition of P. maritima and in developing approaches for further conservation and management of this species within the endangered coastal dune ecosystem of the northeastern United States. PMID:25699222

  19. Effect of Oxygen and Redox Potential on Glucose Fermentation in Thermotoga maritima under Controlled Physicochemical Conditions

    PubMed Central

    Lakhal, Raja; Auria, Richard; Davidson, Sylvain; Ollivier, Bernard; Dolla, Alain; Hamdi, Moktar; Combet-Blanc, Yannick

    2010-01-01

    Batch cultures of Thermotoga maritima were performed in a bioreactor equipped with instruments adapted for experiments performed at 80°C to mimic the fluctuating oxidative conditions in the hot ecosystems it inhabits. When grown anaerobically on glucose, T. maritima was shown to significantly decrease the redox potential (Eh) of the culture medium down to about −480 mV, as long as glucose was available. Addition of oxygen into T. maritima cultures during the stationary growth phase led to a drastic reduction in glucose consumption rate. However, although oxygen was toxic, our experiment unambiguously proved that T. maritima was able to consume it during a 12-hour exposure period. Furthermore, a shift in glucose metabolism towards lactate production was observed under oxidative conditions. PMID:21461371

  20. 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.

  1. The Genome Organization of Thermotoga maritima Reflects Its Lifestyle

    SciTech Connect

    Latif, Haythem; Lerman, Joshua A.; Portnoy, Vasiliy A.; Tarasova, Yekaterina; Nagarajan, Harish; Rutledge, Alexandra C.; Smith, Richard D.; Adkins, Joshua N.; Lee, Dae-Hee; Qiu, Yu; Zengler, Karsten

    2013-04-25

    Recent studies have revealed that microbial genomes have many more organizational features than previously thought. Here, an integrated approach utilizing multiple ‘omics’ datasets and bioinformatics tools is established that elucidates genomic features spanning various levels of cellular organization. This methodology produces gene annotation improvements and includes the definition of transcription units. These enhancements to the annotation enable identification of a set of genetic elements instrumental to gene expression and regulation including promoters, ribosome binding sites (RBSs) and untranslated regions (UTRs). This was applied to characterize the genome organization of Thermotoga maritima—a phylogenetically deep-branching, hyperthermophilic bacterium with a small 1.86 Mb genome. Analysis derived from this multiomics approach in combination with bioinformatics tools demonstrate that the genome organization of T. maritima reflects its lifestyle, both with respect to its extreme growth temperature and compact genome. Comparative analysis of genome features suggests that thermodynamic limitations on binding kinetics for RNA polymerase and the ribosome necessitate increased sequence conservation of promoters and RBSs. Thus, restricting the sequences capable of initiating transcription and translation. Furthermore, this organism has uncharacteristically short 5’UTRs (11-17 nucleotides), which reduce the potential for 5’UTR regulatory interactions. The short intergenic distances in the T. maritima genome (5 bp on average) leave little space for regulation through transcription factor binding. The net effect of these constraints, temperature and genomic space, is a reduced ability to tune gene expression. This effect is readily apparent in global gene expression patterns, which show a high fraction of genes expressed independent of growth state with a tight, linear mRNA/protein correlation (Pearson r = 0.62, p < 2.2 x 10-16 t-test). This methodology

  2. 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

  3. Data on the abundance of the banana weevil Cosmopolites sordidus and of the earwig Euborellia caraibea in bare soil and cover crop plots

    PubMed Central

    Carval, Dominique; Resmond, Rémi; Achard, Raphaël; Tixier, Philippe

    2016-01-01

    The data presented in this article are related to the research article entitled “Cover cropping reduces the abundance of the banana weevil Cosmopolites sordidus but does not reduce its damage to the banana plants” (Carval et al., in press) [1]. This article describes how the abundance of the banana weevil, Cosmopolites sordidus, and the abundance of the earwig Euborellia caraibea were affected by the addition of a cover crop. The field data set is made publicly available to enable critical or extended analyzes. PMID:27222854

  4. Data on the abundance of the banana weevil Cosmopolites sordidus and of the earwig Euborellia caraibea in bare soil and cover crop plots.

    PubMed

    Carval, Dominique; Resmond, Rémi; Achard, Raphaël; Tixier, Philippe

    2016-06-01

    The data presented in this article are related to the research article entitled "Cover cropping reduces the abundance of the banana weevil Cosmopolites sordidus but does not reduce its damage to the banana plants" (Carval et al., in press) [1]. This article describes how the abundance of the banana weevil, Cosmopolites sordidus, and the abundance of the earwig Euborellia caraibea were affected by the addition of a cover crop. The field data set is made publicly available to enable critical or extended analyzes. PMID:27222854

  5. Reverse Gyrase from the Hyperthermophilic Bacterium Thermotoga maritima: Properties and Gene Structure

    PubMed Central

    de la Tour, Claire Bouthier; Portemer, Christiane; Kaltoum, Habib; Duguet, Michel

    1998-01-01

    The hyperthermophilic bacterium Thermotoga maritima MSB8 possesses a reverse gyrase whose enzymatic properties are very similar to those of archaeal reverse gyrases. It catalyzes the positive supercoiling of the DNA in an Mg2+- and ATP-dependent process. Its optimal temperature of activity is around 90°C, and it is highly thermostable. We have cloned and DNA sequenced the corresponding gene (T. maritima topR). This is the first report describing the analysis of a gene encoding a reverse gyrase in bacteria. The T. maritima topR gene codes for a protein of 1,104 amino acids with a deduced molecular weight of 128,259, a value in agreement with that estimated from the denaturing gel electrophoresis of the purified enzyme. Like its archaeal homologs, the T. maritima reverse gyrase exhibits helicase and topoisomerase domains, and its sequence matches very well the consensus sequence for six reverse gyrases now available. Phylogenetic analysis shows that all reverse gyrases, including the T. maritima enzyme, form a very homogeneous group, distinct from the type I 5′ topoisomerases of the TopA subfamily, for which we have previously isolated a representative gene in T. maritima (topA). The coexistence of these two distinct genes, coding for a reverse gyrase and an ω-like topoisomerase, respectively, together with the recent description of a gyrase in T. maritima (O. Guipaud, E. Marguet, K. M. Noll, C. Bouthier de la Tour, and P. Forterre, Proc. Natl. Acad. Sci. USA 94:10606–10611, 1977) addresses the question of the control of the supercoiling in this organism. PMID:9440516

  6. Contribution of Spartina maritima to the reduction of eutrophication in estuarine systems.

    PubMed

    Sousa, Ana I; Lillebø, Ana I; Caçador, Isabel; Pardal, Miguel A

    2008-12-01

    Salt marshes are among the most productive ecosystems in the world, performing important ecosystem functions, particularly nutrient recycling. In this study, a comparison is made between Mondego and Tagus estuaries in relation to the role of Spartina maritima in nitrogen retention capacity and cycling. Two mono-specific S. maritima stands per estuary were studied during 1yr (biomass, nitrogen (N) pools, litter production, decomposition rates). Results showed that the oldest Tagus salt marsh population presented higher annual belowground biomass and N productions, and a slower decomposition rate for litter, contributing to the higher N accumulation in the sediment, whereas S. maritima younger marshes had higher aboveground biomass production. Detritus moved by tides represented a huge amount of aboveground production, probably significant when considering the N balance of these salt marshes. Results reinforce the functions of salt marshes as contributing to a reduction of eutrophication in transitional waters, namely through sedimentation processes. PMID:18684544

  7. The embryonic development of the centipede Strigamia maritima.

    PubMed

    Brena, Carlo; Akam, Michael

    2012-03-01

    The geophilomorph centipede Strigamia maritima is an emerging model for studies of development and evolution among the myriapods. A draft genome sequence has recently been completed, making it also an important reference for comparative genomics, and for studies of myriapod physiology more generally. Here we present the first detailed description of myriapod development using modern techniques. We describe a timeline for embryonic development, with a detailed staging system based on photographs of live eggs and fixed embryos. We show that the early, cleavage and nuclear migration, stages of development are remarkably prolonged, accounting for nearly half of the total developmental period (approx 22 of 48 days at 13 °C). Towards the end of this period, cleavage cells migrate to the egg periphery to generate a uniform blastoderm. Asymmetry quickly becomes apparent as cells in the anterior half of the egg condense ventrally to form the presumptive head. Five anterior segments, the mandibular to the first leg-bearing segment (1st LBS) become clearly visible through the chorion almost simultaneously. Then, after a short pause, the next 35 leg-bearing segments appear at a uniform rate of 1 segment every 3.2 h (at 13 °C). Segment addition then slows to a halt with 40-45 LBS, shortly before the dramatic movements of germ band flexure, when the left and right halves of the embryo separate and the embryo folds deeply into the yolk. After flexure, segment morphogenesis and organogenesis proceed for a further 10 days, before the egg hatches. The last few leg-bearing segments are added during this period, much more slowly, at a rate of 1-2 segments/day. The last leg-bearing segment is fully defined only after apolysis of the embryonic cuticle, so that at hatching the embryo displays the final adult number of leg-bearing segments (typically 47-49 in our population).

  8. Assessing the impacts of salinity and nutrient stress to Ruppia maritima and Zostera marina.

    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 northern...

  9. 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...

  10. ASSESSING THE IMPACTS OF SALINITY AND NUTRIENT STRESS TO RUPPIA MARITIMA AND ZOSTERA MARINA

    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...

  11. Characterization of a tetrameric inositol monophosphatase from the hyperthermophilic bacterium Thermotoga maritima

    SciTech Connect

    Chen, L.; Roberts, M.F.

    1999-10-01

    Inositol monophosphatase (I-1-Pase) catalyzes the dephosphorylation step in the de novo biosynthetic pathway of inositol and is crucial for all inositol-dependent processes. An extremely heat-stable tetrameric form of I-1-Pase from the hyperthermophilic bacterium Thermotoga maritima was overexpressed in Escherichia coli. In addition to its different quaternary structure, this enzyme displayed a 20-fold higher rate of hydrolysis of D-inositol 1-phosphate than of the L isomer. The homogeneous recombinant T. maritima I-1-Pase possessed an unusually high V{sub max} that was much higher than the V{sub max} of the same enzyme from another hyperthermophile, Methanococcus jannaschii. Although T. maritima is a eubacterium, its I-1-Pase is more similar to archaeal I-1-Pases than to the other known bacterial or mammalian I-1-Pases with respect to substrate specificity, Li{sup +} inhibition, inhibition by high Mg{sup 2+} concentrations, metal ion activation, heat stability, and activation energy. Possible reasons for the observed kinetic differences are discussed based on an active site sequence alignment of the human and T. maritima I-1-Pases.

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

    SciTech Connect

    Tagliabue, M.D.; Thursby, G.B.; Walker, H.A.; 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.

  13. Chemical composition of the essential oil of Jacobaea maritima (L.) Pelser & Meijden and Jacobaea maritima subsp. bicolor (Willd.) B. Nord. & Greuter (Asteraceae) collected wild in Croatia and Sicily, respectively.

    PubMed

    Maggio, Antonella; Venditti, Alessandro; Senatore, Felice; Bruno, Maurizio; Formisano, Carmen

    2015-01-01

    In this study, the chemical compositions of the essential oils from aerial parts (JmA) and radices (JmR) of Jacobaea maritima (L.) Pelser & Meijden, collected in Croatia, and of Jacobaea maritima subsp. bicolor (Willd.) B. Nord. & Greuter, collected in Sicily, were evaluated by using gas chromatography and gas chromatography-mass spectrometry. The main components of the essential oil from J. maritima, both in JmA and JmR, were pentacosane (15.7%), heptacosane (13.1%) and nonacosane (8.1%) whereas the essential oil from J. maritima subsp. bicolor was characterised by the presence of hexadecanoic acid (14.6%), caryophyllene oxide (9.3%) and hexahydrofarnesylacetone (6.5%). The comparison of the essential oil with other studied oils of the genus Jacobaea is discussed.

  14. Early effects of salt stress on the physiological and oxidative status of Cakile maritima (halophyte) and Arabidopsis thaliana (glycophyte).

    PubMed

    Ellouzi, Hasna; Hamed, Karim Ben; Cela, Jana; Munné-Bosch, Sergi; Abdelly, Chedly

    2011-06-01

    Early changes in physiological and oxidative status induced by salt stress were monitored in two Brassicaceae plants differing in their tolerance to salinity, Cakile maritima (halophyte) and Arabidopsis thaliana (glycophyte). Growth response and antioxidant defense of C. maritima under 400 mM NaCl were compared with those of A. thaliana exposed to 100 mM NaCl. Salinity induced early growth reduction that is less pronounced in C. maritima than in A. thaliana. Maximum hydrogen peroxide (H₂O₂) level occurred in the leaves of both species 4 h after the onset of salt treatment. A rapid decline in H₂O₂ concentration was observed thereafter in C. maritima, whereas it remained high in A. thaliana. Correlatively, superoxide dismutase, catalase and peroxidase activities increased at 4 h of treatment in C. maritima and decreased thereafter. However, the activity of these enzymes remained higher in treated plants than that in controls, regardless of the duration of treatment, in A. thaliana. The concentrations of malondialdehyde (MDA) reached maximum values at 24 h of salt stress in both species. Again, MDA levels decreased later in C. maritima, but remained high in A. thaliana. The contents of α-tocopherol remained constant during salt stress in C. maritima and decreased during the first 24 h of salt stress and then remained low in A. thaliana. The results clearly showed that C. maritima, in contrast to A. thaliana, can rapidly evolve physiological and antioxidant mechanisms to adapt to salt and manage the oxidative stress. This may explain, at least partially, the difference in salt tolerance between halophytes and glycophytes. PMID:21288246

  15. Using a toxicity test with Ruppia maritima (Linnaeus) to assess the effects of Roundup.

    PubMed

    Castro, Aline de Jesus Veloso; Colares, Ioni Gonçalves; Franco, Teresa Cristina Rodrigues dos Santos; Cutrim, Marco Valerio Jansen; Luvizotto-Santos, Ricardo

    2015-02-28

    Glyphosate, the active ingredient in Monsanto's broad-spectrum herbicide Roundup, consists of one of the most used pesticides worldwide, but its effects on the marine flora are still not well understood. Were examined Roundup toxic effects on Ruppia maritima specimens collected from Jansen Lagoon (São Luís, MA, Brazil) and acclimatized under laboratory conditions. The numbers of new and dead leaves, the root and leaf length, the chlorophyll a content, and the weight of R. maritima branches were determined before and after exposure to different Roundup concentrations for seven days. High concentrations caused a significant lethal effect. In addition, significant changes were observed in the wet and dry weights, the number and length of the leaves, and the chlorophyll a content. Leaf elongation was observed in the branches exposed to low concentrations, and this change was likely activated as a compensatory mechanism. The results indicate that high concentrations of this herbicide may compromise estuarine flora.

  16. Using a toxicity test with Ruppia maritima (Linnaeus) to assess the effects of Roundup.

    PubMed

    Castro, Aline de Jesus Veloso; Colares, Ioni Gonçalves; Franco, Teresa Cristina Rodrigues dos Santos; Cutrim, Marco Valerio Jansen; Luvizotto-Santos, Ricardo

    2015-02-28

    Glyphosate, the active ingredient in Monsanto's broad-spectrum herbicide Roundup, consists of one of the most used pesticides worldwide, but its effects on the marine flora are still not well understood. Were examined Roundup toxic effects on Ruppia maritima specimens collected from Jansen Lagoon (São Luís, MA, Brazil) and acclimatized under laboratory conditions. The numbers of new and dead leaves, the root and leaf length, the chlorophyll a content, and the weight of R. maritima branches were determined before and after exposure to different Roundup concentrations for seven days. High concentrations caused a significant lethal effect. In addition, significant changes were observed in the wet and dry weights, the number and length of the leaves, and the chlorophyll a content. Leaf elongation was observed in the branches exposed to low concentrations, and this change was likely activated as a compensatory mechanism. The results indicate that high concentrations of this herbicide may compromise estuarine flora. PMID:25455815

  17. 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.

  18. Crystallization, preliminary X-ray diffraction and structure analysis of Thermotoga maritima mannitol dehydrogenase

    SciTech Connect

    Puttick, Jennifer; Vieille, Claire; Song, Seung H.; Fodje, Michel N.; Grochulski, Pawel; Delbaere, Louis T. J.

    2007-04-01

    T. maritima mannitol dehydrogenase has been crystallized in space group P2{sub 1}2{sub 1}2{sub 1} with a = 84.43, b = 120.61, c = 145.76 Å. The crystals diffracted to 3.3 Å resolution at the Canadian Light Source. Diffraction data have been collected from a crystal of Thermotoga maritima mannitol dehydrogenase at the Canadian Light Source. The crystal diffracted to 3.3 Å resolution and belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 83.43, b = 120.61, c = 145.76 Å. The structure is likely to be solved by molecular replacement.

  19. Complete genome sequence of Hippea maritima type strain (MH2T)

    SciTech Connect

    Huntemann, Marcel; Lu, Megan; Nolan, Matt; Lapidus, Alla L.; Lucas, Susan; Hammon, Nancy; Deshpande, Shweta; Cheng, Jan-Fang; Tapia, Roxanne; Han, Cliff; Goodwin, Lynne A.; Pitluck, Sam; Liolios, Konstantinos; Pagani, Ioanna; Ivanova, N; Ovchinnikova, Galina; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam L; Hauser, Loren John; Jeffries, Cynthia; Detter, J. Chris; Brambilla, Evelyne-Marie; Rohde, Manfred; Spring, Stefan; Goker, Markus; Woyke, Tanja; Bristow, James; Eisen, Jonathan; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter; Mavromatis, K

    2011-01-01

    Hippea maritima (Miroshnichenko et al. 1999) is the type species of the genus Hippea, which belongs to the family Desulfurellaceae within the class Deltaproteobacteria. The anaerobic, moderately thermophilic marine sulfur-reducer was first isolated from shallow-water hot vents in Matipur Harbor, Papua New Guinea. H. maritima was of interest for genome se- quencing because of its isolated phylogenetic location, as a distant next neighbor of the ge- nus Desulfurella. Strain MH2T is the first type strain from the order Desulfurellales with a com- pletely sequenced genome. The 1,694,430 bp long linear genome with its 1,723 protein- coding and 57 RNA genes consists of one circular chromosome and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  20. Characterization of the Thermotoga maritima Chemotaxis Methylation System that Lacks Methyltransferase CheR:MCP Tethering

    PubMed Central

    Perez, Eduardo; Stock, Ann M.

    2013-01-01

    Summary Sensory adaptation in bacterial chemotaxis is mediated by covalent modifications of specific glutamate and glutamine residues within the cytoplasmic domains of methyl-accepting proteins (MCPs). In Escherichia coli and Salmonella enterica, efficient methylation of MCPs depends on the localization of methyltransferase CheR to MCP clusters through an interaction between the CheR β-subdomain and a pentapeptide sequence (NWETF or NWESF) at the C terminus of the MCP. In vitro methylation analyses utilizing S. enterica and Thermotoga maritima CheR proteins and MCPs indicate that MCP methylation in T. maritima occurs independently of a pentapeptide-binding motif. Kinetic and binding measurements demonstrate that despite efficient methylation, the interaction between T. maritima CheR and T. maritima MCPs is of relatively low affinity. Comparative protein sequence analyses of CheR β-subdomains from organisms having MCPs that contain and/or lack pentapeptide-binding motifs identified key similarities and differences in residue conservation, suggesting the existence of two distinct classes of CheR proteins: pentapeptide-dependent and pentapeptide-independent methyltransferases. Analysis of MCP C-terminal ends showed that only ~10% of MCPs contain a putative C-terminal binding motif, the majority of which are restricted to the different proteobacteria classes (α, β, γ, δ). These findings suggest that tethering of CheR to MCPs is a relatively recent event in evolution and that the pentapeptide-independent methylation system is more common than the well characterized pentapeptide-dependent methylation system. PMID:17163981

  1. Optimization of expression and properties of the recombinant acetohydroxyacid synthase of Thermotoga maritima

    PubMed Central

    Eram, Mohammad S.; Sarafuddin, Benozir; Gong, Frank; Ma, Kesen

    2015-01-01

    The data provide additional support of the characterization of the biophysical and biochemical properties of the enzyme acetohydroxyacid synthase from the hyperthermophilic bacterium Thermotoga maritima (Eram et al., 2015) [1]. The genes encoding the enzyme subunits have been cloned and expressed in the mesophilic host Escherichia coli. Detailed data include information about the optimization of the expression conditions, biophysical properties of the enzyme and reconstitution of the holoenzyme from individually expressed and purified subunits. PMID:26629492

  2. 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.

  3. Structure of a NAD kinase from Thermotoga maritima at 2.3 Å resolution

    SciTech Connect

    Oganesyan, Vaheh; Huang, Candice; Adams, Paul D.; Jancarik, Jaru; Yokota, Hisao A.; Kim, Rosalind; Kim, Sung-Hou

    2005-07-01

    The expression, purification, crystallization, and structure determination of NAD-kinase from T. maritima are reported. Similarity to other NAD-kinases as well as homo-oligomrization state of the enzyme from T. maritima are discussed. NAD kinase is the only known enzyme that catalyzes the formation of NADP, a coenzyme involved in most anabolic reactions and in the antioxidant defense system. Despite its importance, very little is known regarding the mechanism of catalysis and only recently have several NAD kinase structures been deposited in the PDB. Here, an independent investigation of the crystal structure of inorganic polyphosphate/ATP-NAD kinase, PPNK-THEMA, a protein from Thermotoga maritima, is reported at a resolution of 2.3 Å. The crystal structure was solved using single-wavelength anomalous diffraction (SAD) data collected at the Se absorption-peak wavelength in a state in which no cofactors or substrates were bound. It revealed that the 258-amino-acid protein is folded into two distinct domains, similar to recently reported NAD kinases. The N-terminal α/β-domain spans the first 100 amino acids and the last 30 amino acids of the polypeptide and has several topological matches in the PDB, whereas the other domain, which spans the middle 130 residues, adopts a unique β-sandwich architecture and only appreciably matches the recently deposited PDB structures of NAD kinases.

  4. Overexpression, crystallization, and preliminary X-ray crystallographic analysis of shikimate dehydrogenase from Thermotoga maritima.

    PubMed

    Lee, Hyung Ho

    2011-07-01

    Shikimate dehydrogenase (SDH), which catalyses the NADPH-dependent reduction of 3-dehydroshikimate to shikimate in the shikimate pathway, is an attractive target for the development of herbicides and antimicrobial agents. Previous structural studies showed that SDH exists in two conformations, an open form and a closed form, and it is believed that the conformational state is crucial to understanding a catalytic mechanism. To facilitate further structural comparisons among SDHs, structural analysis of an SDH from Thermotoga maritima encoded by the Tm0346 gene has been initiated. SDH from T. maritima has been overexpressed in Escherichia coli and crystallized at 296 K using ammonium sulfate as a precipitant. Crystals of T. maritima SDH diffracted to 1.45 Å resolution and belonged to orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a=54.21, b=62.45 and c=68.68 Å. The asymmetric unit contains a monomer, with a corresponding VM of 2.01 Å3 Da(-1) and a solvent content of 38.9% by volume.

  5. Comparative Transcriptome Analysis of the Cosmopolitan Marine Fungus Corollospora maritima Under Two Physiological Conditions

    PubMed Central

    Velez, Patricia; Alejandri-Ramírez, Naholi D.; González, María C.; Estrada, Karel J.; Sanchez-Flores, Alejandro; Dinkova, Tzvetanka D.

    2015-01-01

    Marine sandy beaches represent dynamic environments often subject to harsh conditions and climate fluctuations, where natural and anthropogenic inputs of freshwater from fluvial and pluvial sources alter salinity, which has been recognized as a key variable affecting the distribution of aquatic organisms and influencing critical physiological processes. The marine arenicolous fungus Corollospora maritima is a worldwide-distributed saprobe that has been reported to present tolerance to freshwater. Here, we present a transcriptome analysis that will provide the first insight of the genomic content for this fungus and a gene expression comparison between two different salinity conditions. We also identified genes that are candidates for being differentially expressed in response to environmental variations on salinity during the fungal growth. The de novo reconstruction of C. maritima transcriptome Illumina sequencing provided a total of 14,530 transcripts (16 megabases). The comparison between the two growth conditions rendered 103 genes specifically overexpressed in seawater, and 132 genes specifically up-regulated under freshwater. Using fungal isolates collected from different beaches, the specific environmental regulation of particular transcript differential expression was confirmed by RT-qPCR. To our knowledge, this is the first analysis that explores the marine fungus C. maritima molecular responses to overcome freshwater stress, and these data could shed light to understand the fungal adaptation and plasticity mechanisms to the marine habitat. PMID:26116293

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

    SciTech Connect

    Tagliabue, M.D.; Thursby, G.B.; Walker, H.A.; 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.

  7. 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

  8. Moving closer towards restoration of contaminated estuaries: Bioaugmentation with autochthonous rhizobacteria improves metal rhizoaccumulation in native Spartina maritima.

    PubMed

    Mesa, Jennifer; Rodríguez-Llorente, Ignacio David; Pajuelo, Eloisa; Piedras, José María Barcia; Caviedes, Miguel Angel; Redondo-Gómez, Susana; Mateos-Naranjo, Enrique

    2015-12-30

    Spartina maritima is an ecosystem engineer that has shown to be useful for phytoremediation purposes. A glasshouse experiment using soil from a metal-contaminated estuary was designed to investigate the effect of a native bacterial consortium, isolated from S. maritima rizhosphere and selected owing to their plant growth promoting properties and multiresistance to heavy metals, on plant growth and metal accumulation. Plants of S. maritima were randomly assigned to three soil bioaugmentation treatments (without inoculation, one inoculation and repeated inoculations) for 30 days. Growth parameters and photosynthetic traits, together with total concentrations of several metals were determined in roots and/or leaves. Bacterial inoculation improved root growth, through a beneficial effect on photosynthetic rate (AN) due to its positive impact on functionality of PSII and chlorophyll concentration. Also, favoured intrinsic water use efficiency of S. maritima, through the increment in AN, stomatal conductance and in root-to-shoot ratio. Moreover, this consortium was able to stimulate plant metal uptake specifically in roots, with increases of up to 19% for As, 65% for Cu, 40% for Pb and 29% for Zn. Thus, bioaugmentation of S. maritima with the selected bacterial consortium can be claimed to enhance plant adaptation and metal rhizoaccumulation during marsh restoration programs. PMID:26188869

  9. Moving closer towards restoration of contaminated estuaries: Bioaugmentation with autochthonous rhizobacteria improves metal rhizoaccumulation in native Spartina maritima.

    PubMed

    Mesa, Jennifer; Rodríguez-Llorente, Ignacio David; Pajuelo, Eloisa; Piedras, José María Barcia; Caviedes, Miguel Angel; Redondo-Gómez, Susana; Mateos-Naranjo, Enrique

    2015-12-30

    Spartina maritima is an ecosystem engineer that has shown to be useful for phytoremediation purposes. A glasshouse experiment using soil from a metal-contaminated estuary was designed to investigate the effect of a native bacterial consortium, isolated from S. maritima rizhosphere and selected owing to their plant growth promoting properties and multiresistance to heavy metals, on plant growth and metal accumulation. Plants of S. maritima were randomly assigned to three soil bioaugmentation treatments (without inoculation, one inoculation and repeated inoculations) for 30 days. Growth parameters and photosynthetic traits, together with total concentrations of several metals were determined in roots and/or leaves. Bacterial inoculation improved root growth, through a beneficial effect on photosynthetic rate (AN) due to its positive impact on functionality of PSII and chlorophyll concentration. Also, favoured intrinsic water use efficiency of S. maritima, through the increment in AN, stomatal conductance and in root-to-shoot ratio. Moreover, this consortium was able to stimulate plant metal uptake specifically in roots, with increases of up to 19% for As, 65% for Cu, 40% for Pb and 29% for Zn. Thus, bioaugmentation of S. maritima with the selected bacterial consortium can be claimed to enhance plant adaptation and metal rhizoaccumulation during marsh restoration programs.

  10. 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.

  11. 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.

  12. The First Myriapod Genome Sequence Reveals Conservative Arthropod Gene Content and Genome Organisation in the Centipede Strigamia maritima

    PubMed Central

    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

    2014-01-01

    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

  13. 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

  14. 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

  15. Effects of Oil-Contaminated Sediments on Submerged Vegetation: An Experimental Assessment of Ruppia maritima.

    PubMed

    Martin, Charles W; Hollis, Lauris O; Turner, R Eugene

    2015-01-01

    Oil spills threaten the productivity of ecosystems through the degradation of coastal flora and the ecosystem services these plants provide. While lab and field investigations have quantified the response of numerous species of emergent vegetation to oil, the effects on submerged vegetation remain uncertain. Here, we discuss the implications of oil exposure for Ruppia maritima, one of the most common species of submerged vegetation found in the region affected by the recent Deepwater Horizon oil spill. We grew R. maritima in a range of manipulated sediment oil concentrations: 0, 0.26, 0.53, and 1.05 mL oil /L tank volume, and tracked changes in growth (wet weight and shoot density/length), reproductive activity (inflorescence and seed production), root characteristics (mass, length, diameter, and area), and uprooting force of plants. While no statistical differences were detected in growth, plants exhibited significant changes to reproductive output, root morphology, and uprooting force. We found significant reductions in inflorescences and fruiting bodies at higher oil concentrations. In addition, the roots growing in the high oil were shorter and wider. Plants in medium and high oil required less force to uproot. A second experiment was performed to separate the effects of root morphology and oiled sediment properties and indicated that there were also changes to sediment cohesion that contributed to a reduction in uprooting forces in medium and high oil. Given the importance of sexual reproduction for these plants, oil contamination may have substantial population-level effects. Moreover, areas containing buried oil may be more susceptible to high energy storm events due to the reduction in uprooting force of foundation species such as R. maritima. PMID:26430971

  16. Effects of Oil-Contaminated Sediments on Submerged Vegetation: An Experimental Assessment of Ruppia maritima.

    PubMed

    Martin, Charles W; Hollis, Lauris O; Turner, R Eugene

    2015-01-01

    Oil spills threaten the productivity of ecosystems through the degradation of coastal flora and the ecosystem services these plants provide. While lab and field investigations have quantified the response of numerous species of emergent vegetation to oil, the effects on submerged vegetation remain uncertain. Here, we discuss the implications of oil exposure for Ruppia maritima, one of the most common species of submerged vegetation found in the region affected by the recent Deepwater Horizon oil spill. We grew R. maritima in a range of manipulated sediment oil concentrations: 0, 0.26, 0.53, and 1.05 mL oil /L tank volume, and tracked changes in growth (wet weight and shoot density/length), reproductive activity (inflorescence and seed production), root characteristics (mass, length, diameter, and area), and uprooting force of plants. While no statistical differences were detected in growth, plants exhibited significant changes to reproductive output, root morphology, and uprooting force. We found significant reductions in inflorescences and fruiting bodies at higher oil concentrations. In addition, the roots growing in the high oil were shorter and wider. Plants in medium and high oil required less force to uproot. A second experiment was performed to separate the effects of root morphology and oiled sediment properties and indicated that there were also changes to sediment cohesion that contributed to a reduction in uprooting forces in medium and high oil. Given the importance of sexual reproduction for these plants, oil contamination may have substantial population-level effects. Moreover, areas containing buried oil may be more susceptible to high energy storm events due to the reduction in uprooting force of foundation species such as R. maritima.

  17. Effects of Oil-Contaminated Sediments on Submerged Vegetation: An Experimental Assessment of Ruppia maritima

    PubMed Central

    Martin, Charles W.; Hollis, Lauris O.; Turner, R. Eugene

    2015-01-01

    Oil spills threaten the productivity of ecosystems through the degradation of coastal flora and the ecosystem services these plants provide. While lab and field investigations have quantified the response of numerous species of emergent vegetation to oil, the effects on submerged vegetation remain uncertain. Here, we discuss the implications of oil exposure for Ruppia maritima, one of the most common species of submerged vegetation found in the region affected by the recent Deepwater Horizon oil spill. We grew R. maritima in a range of manipulated sediment oil concentrations: 0, 0.26, 0.53, and 1.05 mL oil /L tank volume, and tracked changes in growth (wet weight and shoot density/length), reproductive activity (inflorescence and seed production), root characteristics (mass, length, diameter, and area), and uprooting force of plants. While no statistical differences were detected in growth, plants exhibited significant changes to reproductive output, root morphology, and uprooting force. We found significant reductions in inflorescences and fruiting bodies at higher oil concentrations. In addition, the roots growing in the high oil were shorter and wider. Plants in medium and high oil required less force to uproot. A second experiment was performed to separate the effects of root morphology and oiled sediment properties and indicated that there were also changes to sediment cohesion that contributed to a reduction in uprooting forces in medium and high oil. Given the importance of sexual reproduction for these plants, oil contamination may have substantial population-level effects. Moreover, areas containing buried oil may be more susceptible to high energy storm events due to the reduction in uprooting force of foundation species such as R. maritima. PMID:26430971

  18. The role of Spartina maritima and Sarcocornia fruticosa on trace metals retention in Ria Formosa, Portugal

    NASA Astrophysics Data System (ADS)

    Moreira da Silva, Manuela; Duarte, Duarte; Isidoro, Jorge; Chícharo, Luís

    2013-04-01

    Over the last years, phytoremediation has become an increasingly recognized pathway for contaminant removal from water and shallow soils. Assessing the phytoremediation potential of wetlands is complex due to variable conditions of hydrology, soil/sediment types, plant species diversity, growing season and water chemistry. Physico-chemical properties of wetlands provide many positive attributes for remediating contaminants. Saltmarsh plants can sequestrate and inherently tolerate high metal concentrations found in saltmarsh sediments. An increasing number of studies have been carried out to understand the role of halophyte vegetation on retention, biovailability and remediation of the pollutants in coastal areas (estuaries and lagoons). It is already known that the accumulation capacity and the pattern of metal distribution in the plant tissues vary among plant species, namely monocotyledonous and dicotyledonous, and with sediment characteristics. During the last decades, there has been a large increase in urbanization and industrialization of the area surrounding Ria Formosa. Due to this reality, anthropogenic contaminants, including trace metals, are transported via untreated sewage and agricultural effluents to several parts of the lagoon. The dominant producers are Spartina maritima (Poales: Poaceae) and Sarcocornia fruticosa (Caryophyllales: Chenopodiaceae), appearing in pure stands respectively in the lower and in the upper saltmarshes. The aim of this work was to survey, comparatively, the role of S. maritima and S. fruticosa on minor and trace element (Ag, Cd, Cu, Cr, Mo, Ni, Pb and Zn), contents and distribution amongst sediment and plant tissues. Both S. maritima and S. fruticosa could fix metals from the surrounding belowground environment and accumulate metals, mainly in roots (also in rhizomes in the case of the former). Metal translocation to aerial parts of the plants was, in general, residual.

  19. [Expression and purification of thermostable alpha-glucuronidase from Thermotoga maritima].

    PubMed

    Xue, Ye-Min; Mao, Zhong-Gui; Shao, Wei-Lan

    2004-07-01

    The xylanolytic enzymes found in Thermotoga maritima showed extremely high thermostability and considerable potential in industrial application. Yet expression level of the genes encoding these enzymes was very low. The alpha-glucuronidase gene aguA from T. maritima ATCC 43589 was cloned and expressed in several E. coli strains with different vector. The alpha-glucuronidase was overexpressed in E. coli BL21-CodonPlus(DE3)-RIL with plasmid pET-28a(+), and made up about 20% of the total proteins present in the intracellular soluble fraction. The results proved the assumption that rare codons for arginine (AGA/AGG) and isoleucine (AUA) affect the expression of aguA gene from hyperthermophilic bacterium T. maritima in E. coli. Purification procedure included two steps, heat treatment and immobilized metal affinity chromatography, and over 13.5mg of pure enzyme was obrained from 1L of induced culture. The purified enzyme showed a single band on SDS polyacrylamide gel electrophoresis with a purification of 5.1 fold, and a yield of 55.1%. The optimum activity of recombinant alpha-glucuronidase was found at pH 6.0 and 85 degrees C, the enzyme retained 70% of its activity after 1 h of incubation at 85 degrees C. The induction conditions for expression of recombinant strain BL21-CodonPlus(DE3)-RIL/pET-28a-aguA were studied on induction time and duration by IPTG. The results showed that the activity of thermostable alpha-glucuronidase reach the maximum in 5-hour after inducted at the exponential phase (OD600 of 0.7 - 0.8).

  20. Abridged 5S rDNA units in sea beet (Beta vulgaris subsp. maritima).

    PubMed

    Turner, Daniel J; Brown, Terence A

    2005-04-01

    Amplification by polymerase chain reaction of the 5S rDNA repeat units of Beta vulgaris subsp. maritima resulted in a 350-bp product corresponding to the full-length 5S unit, but also revealed 4 abridged unit classes, each with a deletion that removed most of the spacer and 12-76 bp of the coding sequence. Each abridged type lacks at least 1 of the conserved elements involved in transcription of the 5S gene, and so appear to be nonfunctional. Network analysis revealed that the abridged units are evolving in the same manner as the full-length versions.

  1. Biophysical probing of Spartina maritima photo-system II changes during prolonged tidal submersion periods.

    PubMed

    Duarte, B; Santos, D; Marques, J C; Caçador, I

    2014-04-01

    Submergence is one of the major constrains affecting wetland plants, with inevitable impacts on their physiology and productivity. Global warming as a driving force of sea level rise, tend to increase the submersion periods duration. Photosynthesis biophysical probing arise as an important tool to understand the energetics underlying plant feedback to these constrains. As in previous studies with Spartina maritima, there was no inhibition of photosynthetic activity in submerged individuals. Comparing both donor and acceptor sides of the PSII, the first was more severely affected during submersion, driven by the inactivation of the OEC with consequent impairment of the ETC. Although this apparent damage in the PSII donor side, the electron transport per active reaction centre was not substantially affected, indicating that this reduction in the electron flow is accompanied by a proportional increase in the number of active reaction centres. These conditions lead to the accumulation of excessive reducing power, source of damaging ROS, counteracted by efficient energy dissipation processes and anti-oxidant enzymatic defences. This way, S. maritima appears as a well-adapted species with an evident photochemical plasticity towards submersion, allowing it to maintain its photosynthetic activity even during prolonged submersion periods.

  2. The chloroplast genome of the hexaploid Spartina maritima (Poaceae, Chloridoideae): Comparative analyses and molecular dating.

    PubMed

    Rousseau-Gueutin, M; Bellot, S; Martin, G E; Boutte, J; Chelaifa, H; Lima, O; Michon-Coudouel, S; Naquin, D; Salmon, A; Ainouche, K; Ainouche, M

    2015-12-01

    The history of many plant lineages is complicated by reticulate evolution with cases of hybridization often followed by genome duplication (allopolyploidy). In such a context, the inference of phylogenetic relationships and biogeographic scenarios based on molecular data is easier using haploid markers like chloroplast genome sequences. Hybridization and polyploidization occurred recurrently in the genus Spartina (Poaceae, Chloridoideae), as illustrated by the recent formation of the invasive allododecaploid S. anglica during the 19th century in Europe. Until now, only a few plastid markers were available to explore the history of this genus and their low variability limited the resolution of species relationships. We sequenced the complete chloroplast genome (plastome) of S. maritima, the native European parent of S. anglica, and compared it to the plastomes of other Poaceae. Our analysis revealed the presence of fast-evolving regions of potential taxonomic, phylogeographic and phylogenetic utility at various levels within the Poaceae family. Using secondary calibrations, we show that the tetraploid and hexaploid lineages of Spartina diverged 6-10 my ago, and that the two parents of the invasive allopolyploid S. anglica separated 2-4 my ago via long distance dispersal of the ancestor of S. maritima over the Atlantic Ocean. Finally, we discuss the meaning of divergence times between chloroplast genomes in the context of reticulate evolution.

  3. Biophysical probing of Spartina maritima photo-system II changes during prolonged tidal submersion periods.

    PubMed

    Duarte, B; Santos, D; Marques, J C; Caçador, I

    2014-04-01

    Submergence is one of the major constrains affecting wetland plants, with inevitable impacts on their physiology and productivity. Global warming as a driving force of sea level rise, tend to increase the submersion periods duration. Photosynthesis biophysical probing arise as an important tool to understand the energetics underlying plant feedback to these constrains. As in previous studies with Spartina maritima, there was no inhibition of photosynthetic activity in submerged individuals. Comparing both donor and acceptor sides of the PSII, the first was more severely affected during submersion, driven by the inactivation of the OEC with consequent impairment of the ETC. Although this apparent damage in the PSII donor side, the electron transport per active reaction centre was not substantially affected, indicating that this reduction in the electron flow is accompanied by a proportional increase in the number of active reaction centres. These conditions lead to the accumulation of excessive reducing power, source of damaging ROS, counteracted by efficient energy dissipation processes and anti-oxidant enzymatic defences. This way, S. maritima appears as a well-adapted species with an evident photochemical plasticity towards submersion, allowing it to maintain its photosynthetic activity even during prolonged submersion periods. PMID:24630362

  4. Essential Oils from Anthemis maritima Flowers: Infraspecific Variability along the Adriatic Coast (Italy).

    PubMed

    Ciccarelli, Daniela; Giovanelli, Silvia; Pistelli, Luisa

    2016-05-01

    The hydrodistilled essential oils (EOs) from flowers of five Adriatic populations of Anthemis maritima were analyzed by GC-FID and GC/MS. Anthemis maritima is a psammophilous plant living generally on coastal sand dunes but occasionally on sea cliffs and shingle beaches. A total of 163 chemical compounds were identified, accounting for 90.5% of the oils. The main classes of compounds represented in the EOs were monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpene hydrocarbons, oxygenated sesquiterpenes, and terpene esters.The multivariate chemometric techniques, in particular cluster analysis and principal coordinate analysis, used to classify the samples, highlighted three different chemotypes linked to a geographic origin. One group living in northern Italy was characterized by the highest content of β-pinene, γ-terpinene, and β-caryophyllene, a second chemotype was in central Italy with the highest amount of trans-chrysanthenyl acetate and a third group living in southern Italy with a more heterogeneous volatile profile was characterized by the highest values of cis-chrysanthenyl acetate, trans-chrysanthenyl isobutyrate, cis-carveol propionate, α-zingiberene, and cubenol. Moreover, the comparison of the Adriatic populations with the Tyrrhenian samples, analyzed in a previous research, showed that cubenol (absent in all the Tyrrhenian populations) and (E)-β-farnesene (absent in all the Adriatic samples) play a crucial role in discriminating the Italian populations. PMID:27114258

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

    SciTech Connect

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

    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.

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

    SciTech Connect

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

    2013-02-01

    A 2.15 Å resolution crystal structure of TM0159 with bound IMP and enzyme-kinetic data are presented. This noncanonical nucleoside triphosphatase from T. maritima helps to maintain a correct pool of DNA and RNA precursor molecules. 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{sub cat}/K{sub m} values determined at 323 and 353 K fall between 1.31 × 10{sup 4} and 7.80 × 10{sup 4} M{sup −1} s{sup −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 Mg{sup 2+} 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)

  7. Responses of Wild-Type and Resistant Strains of the Hyperthermophilic Bacterium Thermotoga maritima to Chloramphenicol Challenge▿ †

    PubMed Central

    Montero, Clemente I.; Johnson, Matthew R.; Chou, Chung-Jung; Conners, Shannon B.; Geouge, Sarah G.; Tachdjian, Sabrina; Nichols, Jason D.; Kelly, Robert M.

    2007-01-01

    Transcriptomes and growth physiologies of the hyperthermophile Thermotoga maritima and an antibiotic-resistant spontaneous mutant were compared prior to and following exposure to chloramphenicol. While the wild-type response was similar to that of mesophilic bacteria, reduced susceptibility of the mutant was attributed to five mutations in 23S rRNA and phenotypic preconditioning to chloramphenicol. PMID:17557852

  8. Chemical composition and biological effects of Artemisia maritima and Artemisia nilagirica essential oils from wild plants of western Himalaya.

    PubMed

    Stappen, Iris; Wanner, Jürgen; Tabanca, Nurhayat; Wedge, David E; Ali, Abbas; Khan, Ikhlas A; Kaul, Vijay K; Lal, Brij; Jaitak, Vikas; Gochev, Velizar; Girova, Tania; Stoyanova, Albena; Schmidt, Erich; Jirovetz, Leopold

    2014-08-01

    Artemisia species possess pharmacological properties that are used for medical purposes worldwide. In this paper, the essential oils from the aerial parts of Artemisia nilagirica and Artemisia maritima from the western Indian Himalaya region are described. The main compounds analyzed by simultaneous GC/MS and GC/FID were camphor and 1,8-cineole from A. maritima, and camphor and artemisia ketone from A. nilagirica. Additionally, the oils were evaluated for their antibacterial, antifungal, mosquito biting deterrent, and larvicidal activities. A. nilagirica essential oil demonstrated nonselective antifungal activity against plant pathogens Colletotrichum acutatum, Colletotrichum fragariae, and Colletotrichum gloeosporioides, whereas A. maritima did not show antifungal activity. Both Artemisia spp. exhibited considerable mosquito biting deterrence, whereas only A. nilagirica showed larvicidal activity against Aedes aegypti. Antibacterial effects assessed by an agar dilution assay demonstrated greater activity of A. maritima essential oil against Staphylococcus aureus and Pseudomonas aeruginosa compared to A. nilagirica.

  9. Chemical composition and biological effects of Artemisia maritima and Artemisia nilagirica essential oils from wild plant of Western Himalaya

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Artemisia species possess pharmacological properties that are used for medical purposes worldwide. In this paper, the essential oils from the aerial parts of A. nilagirica and A. maritima from the western Indian Himalaya region are described. The main compounds analyzed by simultaneous GC/MS and GC/...

  10. 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...

  11. Chemical composition and biological effects of Artemisia maritima and Artemisia nilagirica essential oils from wild plants of western Himalaya.

    PubMed

    Stappen, Iris; Wanner, Jürgen; Tabanca, Nurhayat; Wedge, David E; Ali, Abbas; Khan, Ikhlas A; Kaul, Vijay K; Lal, Brij; Jaitak, Vikas; Gochev, Velizar; Girova, Tania; Stoyanova, Albena; Schmidt, Erich; Jirovetz, Leopold

    2014-08-01

    Artemisia species possess pharmacological properties that are used for medical purposes worldwide. In this paper, the essential oils from the aerial parts of Artemisia nilagirica and Artemisia maritima from the western Indian Himalaya region are described. The main compounds analyzed by simultaneous GC/MS and GC/FID were camphor and 1,8-cineole from A. maritima, and camphor and artemisia ketone from A. nilagirica. Additionally, the oils were evaluated for their antibacterial, antifungal, mosquito biting deterrent, and larvicidal activities. A. nilagirica essential oil demonstrated nonselective antifungal activity against plant pathogens Colletotrichum acutatum, Colletotrichum fragariae, and Colletotrichum gloeosporioides, whereas A. maritima did not show antifungal activity. Both Artemisia spp. exhibited considerable mosquito biting deterrence, whereas only A. nilagirica showed larvicidal activity against Aedes aegypti. Antibacterial effects assessed by an agar dilution assay demonstrated greater activity of A. maritima essential oil against Staphylococcus aureus and Pseudomonas aeruginosa compared to A. nilagirica. PMID:25127023

  12. Comparison of NaCl-induced programmed cell death in the obligate halophyte Cakile maritima and the glycophyte Arabidopsis thaliana.

    PubMed

    Ben Hamed-Laouti, Ibtissem; Arbelet-Bonnin, Delphine; De Bont, Linda; Biligui, Bernadette; Gakière, Bertrand; Abdelly, Chedly; Ben Hamed, Karim; Bouteau, François

    2016-06-01

    Salinity represents one of the most important constraints that adversely affect plants growth and productivity. In this study, we aimed at determining possible differences between salt tolerant and salt sensitive species in early salt stress response. To this purpose, we subjected suspension-cultured cells from the halophyte Cakile maritima and the glycophyte Arabidopsis thaliana, two Brassicaceae, to salt stress and compared their behavior. In both species we could observe a time and dose dependent programmed cell death requiring an active metabolism, a dysfunction of mitochondria and caspase-like activation although C. maritima cells appeared less sensitive than A. thaliana cells. This capacity to mitigate salt stress could be due to a higher ascorbate pool that could allow C. maritima reducing the oxidative stress generated in response to NaCl. It further appeared that a higher number of C. maritima cultured cells when compared to A. thaliana could efficiently manage the Na(+) accumulation into the cytoplasm through non selective cation channels allowing also reducing the ROS generation and the subsequent cell death. PMID:27095399

  13. Arginine Biosynthesis in Thermotoga maritima: Characterization of the Arginine-Sensitive N-Acetyl-l-Glutamate Kinase

    PubMed Central

    Fernández-Murga, M. Leonor; Gil-Ortiz, Fernando; Llácer, José L.; Rubio, Vicente

    2004-01-01

    To help clarify the control of arginine synthesis in Thermotoga maritima, the putative gene (argB) for N-acetyl-l-glutamate kinase (NAGK) from this microorganism was cloned and overexpressed, and the resulting protein was purified and shown to be a highly thermostable and specific NAGK that is potently and selectively inhibited by arginine. Therefore, NAGK is in T. maritima the feedback control point of arginine synthesis, a process that in this organism involves acetyl group recycling and appears not to involve classical acetylglutamate synthase. The inhibition of NAGK by arginine was found to be pH independent and to depend sigmoidally on the concentration of arginine, with a Hill coefficient (N) of ∼4, and the 50% inhibitory arginine concentration (I0.5) was shown to increase with temperature, approaching above 65°C the I0.50 observed at 37°C with the mesophilic NAGK of Pseudomonas aeruginosa (the best-studied arginine-inhibitable NAGK). At 75°C, the inhibition by arginine of T. maritima NAGK was due to a large increase in the Km for acetylglutamate triggered by the inhibitor, but at 37°C arginine also substantially decreased the Vmax of the enzyme. The NAGKs of T. maritima and P. aeruginosa behaved in gel filtration as hexamers, justifying the sigmoidicity and high Hill coefficient of arginine inhibition, and arginine or the substrates failed to disaggregate these enzymes. In contrast, Escherichia coli NAGK is not inhibited by arginine and is dimeric, and thus the hexameric architecture may be an important determinant of arginine sensitivity. Potential thermostability determinants of T. maritima NAGK are also discussed. PMID:15342584

  14. Characterization of a cDNA from Beta maritima that confers nickel tolerance in yeast.

    PubMed

    Bozdag, Gonensin O; Kaya, Alaattin; Koc, Ahmet; Noll, Gundula A; Prüfer, Dirk; Karakaya, Hüseyin Caglar

    2014-04-01

    Nickel is an essential micronutrient due to its involvement in many enzymatic reactions as a cofactor. However, excess of this element is toxic to biological systems. Here, we constructed a cDNA library from Beta maritima and screened it in the yeast system to identify genes that confer resistance to toxic levels of nickel. A cDNA clone (NIC6), which encodes for a putative membrane protein with unknown function, was found to help yeast cells to tolerate toxic levels of nickel. A GFP fused form of Nic6 protein was localized to multivesicular structures in tobacco epidermal cells. Thus, our results suggest a possible role of Nic6 in nickel and intracellular ion homeostasis.

  15. Engineering of TM1459 from Thermotoga maritima for Increased Oxidative Alkene Cleavage Activity

    PubMed Central

    Fink, Matthias; Trunk, Sarah; Hall, Mélanie; Schwab, Helmut; Steiner, Kerstin

    2016-01-01

    Oxidative cleavage of alkenes is a widely employed process allowing oxyfunctionalization to corresponding carbonyl compounds. Recently, a novel biocatalytic oxidative alkene cleavage activity on styrene derivatives was identified in TM1459 from Thermotoga maritima. In this work we engineered the enzyme by site-saturation mutagenesis of active site amino acids to increase its activity and to broaden its substrate scope. A high-throughput assay for the detection of the ketone products was successfully developed. Several variants with up to twofold improved conversion level of styrene derivatives were successfully identified. Especially, changes in or removal of the C-terminus of TM1459 increased the activity most significantly. These best variants also displayed a slightly enlarged substrate scope. PMID:27713741

  16. Isolation and characterization of 28 microsatellite loci for a Korean endemic, Lespedeza maritima (Fabaceae)1

    PubMed Central

    Jin, Dong-Pil; Cho, Won-Bum; Choi, In-Su; Choi, Byoung-Hee

    2016-01-01

    Premise of the study: We developed microsatellite primers for Lespedeza maritima (Fabaceae), a Korean endemic shrub, and conducted cross-amplifications for closely related species. Methods and Results: We produced 28 polymorphic microsatellite markers through reference mapping of 300-bp paired-end reads obtained from Illumina MiSeq data. For 47 individual plants from two populations, the total alleles numbered two to 13, and observed and expected heterozygosities ranged from 0.067 to 0.867 and from 0.064 to 0.848, respectively. Most of these markers were well amplified in closely related species. Conclusions: In future research, the microsatellite markers described here will help reveal the taxonomic entity of this species. PMID:26819860

  17. 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

  18. Molecular cloning and characterization of novel cystatin gene in leaves Cakile maritima halophyte.

    PubMed

    Megdiche, Wided; Passaquet, Chantal; Zourrig, Walid; Zuily Fodil, Yasmine; Abdelly, Chedly

    2009-05-01

    Cakile maritima (Brassicaceae) is a halophyte that thrives on dunes along Mediterranean seashores, with high tolerance to salty and dry environments. We have previously shown that there is great morphological and physiological diversity between ecotypes. We investigated the expression of cysteine protease inhibitor (cystatin) genes in the response to hydric and saline constraints, as cystatins are known to participate in the response to environmental constraints in plants. We isolated, from C. maritime, a new cystatin cDNA (CmC) that encodes a 221 amino acid protein with a calculated molecular mass of 25 kDa. It displays a moderate-to-high amino acid sequence similarity with previously reported phytocystatin genes. The predicted protein is hydrophilic, with only one hydrophobic region, just at its N-terminus, and a calculated isoelectric point of 6.7. Sequence analysis revealed a monocystatin structure with one cystatin-like domain. The predicted protein CmC contains the main conserved motifs characteristic of the plant cystatins, and a putative site of phosphorylation by casein kinase II (TPSD). As some cystatins, it contains a C-terminal extension of 106 amino acid residues, with several conserved cystatin motifs. The expression was constitutive in non-stressed plants, with different levels between the ecotypes, and without apparent relation to the climatic area of origin. Augmented expression was observed under severe salinity except in the ecotype from the arid region. Water deficit also increased CmC expression in two ecotypes, with the highest value observed in the ecotype from the humid region. These results indicate that C. maritima responds to high salinity and water deficit by expressing a cystatin gene that is a known component of defense against abiotic constraints or biotic aggression and survival machinery.

  19. Structure of thermotoga maritima stationary phase survival protein SurE : a novel acid phosphatase.

    SciTech Connect

    Zhang, R.-G; Skarina, T.; Katz, J. E.; Khachatryan, A; Vyas, S.; Arrowsmith, C. H.; Clarke, S.; Edwards, A.; Joachimiak, A.; Savchenko, A.; Biosciences Division; Univ. of Toronto; Univ. of California; Clinical Genomics Centre /Proteomics, Univ. Health Network

    2001-11-01

    Background: The rpoS, nlpD, pcm, and surE genes are among many whose expression is induced during the stationary phase of bacterial growth. rpoS codes for the stationary-phase RNA polymerase {sigma} subunit, and nlpD codes for a lipoprotein. The pcm gene product repairs damaged proteins by converting the atypical isoaspartyl residues back to L-aspartyls. The physiological and biochemical functions of surE are unknown, but its importance in stress is supported by the duplication of the surE gene in E. coli subjected to high-temperature growth. The pcm and surE genes are highly conserved in bacteria, archaea, and plants. Results: The structure of SurE from Thermotoga maritima was determined at 2.0 Angstroms. The SurE monomer is composed of two domains; a conserved N-terminal domain, a Rossman fold, and a C-terminal oligomerization domain, a new fold. Monomers form a dimer that assembles into a tetramer. Biochemical analysis suggests that SurE is an acid phosphatase, with an optimum pH of 5.5-6.2. The active site was identified in the N-terminal domain through analysis of conserved residues. Structure-based site-directed point mutations abolished phosphatase activity. T. maritima SurE intra- and intersubunit salt bridges were identified that may explain the SurE thermostability. Conclusions: The structure of SurE provided information about the protein's fold, oligomeric state, and active site. The protein possessed magnesium-dependent acid phosphatase activity, but the physiologically relevant substrate(s) remains to be identified. The importance of three of the assigned active site residues in catalysis was confirmed by site-directed mutagenesis.

  20. Structure of the endonuclease IV homologue from Thermotoga maritima in the presence of active-site divalent metal ions

    SciTech Connect

    Tomanicek, Stephen J.; Hughes, Ronny C.; Ng, Joseph D.; Coates, Leighton

    2010-10-05

    The most frequent lesion in DNA is at apurinic/apyrimidinic (AP) sites resulting from DNA-base losses. These AP-site lesions can stall DNA replication and lead to genome instability if left unrepaired. The AP endonucleases are an important class of enzymes that are involved in the repair of AP-site intermediates during damage-general DNA base-excision repair pathways. These enzymes hydrolytically cleave the 5{prime}-phosphodiester bond at an AP site to generate a free 3{prime}-hydroxyl group and a 5{prime}-terminal sugar phosphate using their AP nuclease activity. Specifically, Thermotoga maritima endonuclease IV is a member of the second conserved AP endonuclease family that includes Escherichia coli endonuclease IV, which is the archetype of the AP endonuclease superfamily. In order to more fully characterize the AP endonuclease family of enzymes, two X-ray crystal structures of the T. maritima endonuclease IV homologue were determined in the presence of divalent metal ions bound in the active-site region. These structures of the T. maritima endonuclease IV homologue further revealed the use of the TIM-barrel fold and the trinuclear metal binding site as important highly conserved structural elements that are involved in DNA-binding and AP-site repair processes in the AP endonuclease superfamily.

  1. Endophytic Cultivable Bacteria of the Metal Bioaccumulator Spartina maritima Improve Plant Growth but Not Metal Uptake in Polluted Marshes Soils.

    PubMed

    Mesa, Jennifer; Mateos-Naranjo, Enrique; Caviedes, Miguel A; Redondo-Gómez, Susana; Pajuelo, Eloisa; Rodríguez-Llorente, Ignacio D

    2015-01-01

    Endophytic bacterial population was isolated from Spartina maritima tissues, a heavy metal bioaccumulator cordgrass growing in the estuaries of Tinto, Odiel, and Piedras River (south west Spain), one of the most polluted areas in the world. Strains were identified and ability to tolerate salt and heavy metals along with plant growth promoting and enzymatic properties were analyzed. A high proportion of these bacteria were resistant toward one or several heavy metals and metalloids including As, Cu, and Zn, the most abundant in plant tissues and soil. These strains also exhibited multiple enzymatic properties as amylase, cellulase, chitinase, protease and lipase, as well as plant growth promoting properties, including nitrogen fixation, phosphates solubilization, and production of indole-3-acetic acid (IAA), siderophores and 1-aminocyclopropane-1-carboxylate (ACC) deaminase. The best performing strains (Micrococcus yunnanensis SMJ12, Vibrio sagamiensis SMJ18, and Salinicola peritrichatus SMJ30) were selected and tested as a consortium by inoculating S. maritima wild plantlets in greenhouse conditions along with wild polluted soil. After 30 days, bacterial inoculation improved plant photosynthetic traits and favored intrinsic water use efficiency. However, far from stimulating plant metal uptake, endophytic inoculation lessened metal accumulation in above and belowground tissues. These results suggest that inoculation of S. maritima with indigenous metal-resistant endophytes could mean a useful approach in order to accelerate both adaption and growth of this indigenous cordgrass in polluted estuaries in restorative operations, but may not be suitable for rhizoaccumulation purposes. PMID:26733985

  2. Characterization of two genes encoding metal tolerance proteins from Beta vulgaris subspecies maritima that confers manganese tolerance in yeast.

    PubMed

    Erbasol, Isil; Bozdag, Gonensin Ozan; Koc, Ahmet; Pedas, Pai; Karakaya, Huseyin Caglar

    2013-10-01

    Manganese (Mn(2+)) is an essential micronutrient in plants. However increased Mn(2+) levels are toxic to plant cells. Metal tolerance proteins (MTPs), member of cation diffusion facilitator protein (CDF) family, have important roles in metal homeostatis in different plant species and catalyse efflux of excess metal ions. In this study, we identified and characterized two MTP genes from Beta vulgaris spp. maritima (B. v. ssp. maritima). Overexpression of these two genes provided Mn tolerance in yeast cells. Sequence analyses displayed BmMTP10 and BmMTP11 as members of the Mn-CDF family. Functional analyses of these proteins indicated that they are specific to Mn(2+) with a role in reducing excess cellular Mn(2+) levels when expressed in yeast. GFP-fusion constructs of both proteins localized to the Golgi apparatus as a punctuated pattern. Finally, Q-RT-PCR results showed that BmMTP10 expression was induced threefold in response to the excess Mn(2+) treatment. On the other hand BmMTP11 expression was not affected in response to excess Mn(2+) levels. Thus, our results suggest that the BmMTP10 and BmMTP11 proteins from B. v. ssp. maritima have non-redundant functions in terms of Mn(2+) detoxification with a similar in planta localization and function as the Arabidopsis Mn-CDF homolog AtMTP11 and this conservation shows the evolutionary importance of these vesicular proteins in heavy metal homeostatis among plant species.

  3. Endophytic Cultivable Bacteria of the Metal Bioaccumulator Spartina maritima Improve Plant Growth but Not Metal Uptake in Polluted Marshes Soils

    PubMed Central

    Mesa, Jennifer; Mateos-Naranjo, Enrique; Caviedes, Miguel A.; Redondo-Gómez, Susana; Pajuelo, Eloisa; Rodríguez-Llorente, Ignacio D.

    2015-01-01

    Endophytic bacterial population was isolated from Spartina maritima tissues, a heavy metal bioaccumulator cordgrass growing in the estuaries of Tinto, Odiel, and Piedras River (south west Spain), one of the most polluted areas in the world. Strains were identified and ability to tolerate salt and heavy metals along with plant growth promoting and enzymatic properties were analyzed. A high proportion of these bacteria were resistant toward one or several heavy metals and metalloids including As, Cu, and Zn, the most abundant in plant tissues and soil. These strains also exhibited multiple enzymatic properties as amylase, cellulase, chitinase, protease and lipase, as well as plant growth promoting properties, including nitrogen fixation, phosphates solubilization, and production of indole-3-acetic acid (IAA), siderophores and 1-aminocyclopropane-1-carboxylate (ACC) deaminase. The best performing strains (Micrococcus yunnanensis SMJ12, Vibrio sagamiensis SMJ18, and Salinicola peritrichatus SMJ30) were selected and tested as a consortium by inoculating S. maritima wild plantlets in greenhouse conditions along with wild polluted soil. After 30 days, bacterial inoculation improved plant photosynthetic traits and favored intrinsic water use efficiency. However, far from stimulating plant metal uptake, endophytic inoculation lessened metal accumulation in above and belowground tissues. These results suggest that inoculation of S. maritima with indigenous metal-resistant endophytes could mean a useful approach in order to accelerate both adaption and growth of this indigenous cordgrass in polluted estuaries in restorative operations, but may not be suitable for rhizoaccumulation purposes. PMID:26733985

  4. The influence of Spartina maritima on carbon retention capacity in salt marshes from warm-temperate estuaries.

    PubMed

    Sousa, Ana I; Lillebø, Ana I; Pardal, Miguel A; Caçador, Isabel

    2010-01-01

    Salt marshes constitute highly productive systems playing an important role on ecosystem functions. The aim of this study is to compare the role of Spartina maritima salt marshes on carbon cycling. Thus, four salt marshes located in two mesotidal estuarine systems (Tagus and Mondego, two salt marshes per estuary) were studied. The S. maritima above- and belowground biomass, carbon production, decomposition rates (through a litterbag experiment) and carbon content in the sediment were estimated for a one year period in both systems and compared. In Corroios (located at the Tagus estuary) S. maritima salt marsh had the highest belowground production (1008 gC m(-2) y(-1)), slower decomposition rate (k=0.0024 d(-1)), and the highest carbon content in sediments (750 gC m(-2) y(-1)); and thus, the highest carbon retention capacity. The other three salt marshes had comparatively higher aboveground productions, higher decomposition rates and lower carbon retention capacity. Therefore, Corroios had the most important carbon cycling characteristics. As a whole, results show that differences in carbon cycling in salt marshes depend mostly on its own characteristics and maturity, rather than the system itself. The intrinsic characteristics of the salt marshes, namely the physicochemical conditions determined by the maturity of the system, are more important factors affecting the role of warm-temperate mesotidal salt marshes as carbon sinks. PMID:20304438

  5. Morphological and genetic distinctiveness of metallicolous and non-metallicolous populations of Armeria maritima s.l. (Plumbaginaceae) in Poland.

    PubMed

    Abratowska, A; Wąsowicz, P; Bednarek, P T; Telka, J; Wierzbicka, M

    2012-07-01

    Patterns of morphological, genetic and epigenetic variation (DNA methylation pattern) were investigated in metallicolous (M) and non-metallicolous (NM) populations of Armeria maritima. A morphological study was carried out using plants from six natural populations grown in a greenhouse. Morphological variation was assessed using seven traits. On the basis of this study, three representative populations were selected for molecular analyses using metAFLP to study sequence- and methylation-based DNA variation. Only one morphological trait (length of outer involucral bracts) was common to both metallicolous populations studied; however, the level of variation was sufficient to differentiate between M and NM populations. Molecular analyses showed the existence of naturally occurring epigenetic variation in A. maritima populations, as well as structuring into distinct between and within population components. We show that patterns of population genetic structure differed depending on the information used in the study. Analysis of sequence-based information data demonstrates the presence of three well-defined and genetically differentiated populations. Methylation-based data show that two major groups of individuals are present, corresponding to the division into M and NM populations. These results were confirmed using different analytical approaches, which suggest that the DNA methylation pattern is similar in both M populations. We hypothesise that epigenetic processes may be involved in microevolution leading to development of M populations in A. maritima. PMID:22243547

  6. 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.

  7. Characterization and structural modeling of a new type of thermostable esterase from Thermotoga maritima.

    PubMed

    Levisson, Mark; van der Oost, John; Kengen, Servé W M

    2007-06-01

    A bioinformatic screening of the genome of the hyperthermophilic bacterium Thermotoga maritima for ester-hydrolyzing enzymes revealed a protein with typical esterase motifs, though annotated as a hypothetical protein. To confirm its putative esterase function the gene (estD) was cloned, functionally expressed in Escherichia coli and purified to homogeneity. Recombinant EstD was found to exhibit significant esterase activity with a preference for short acyl chain esters (C4-C8). The monomeric enzyme has a molecular mass of 44.5 kDa and optimal activity around 95 degrees C and at pH 7. Its thermostability is relatively high with a half-life of 1 h at 100 degrees C, but less stable compared to some other hyperthermophilic esterases. A structural model was constructed with the carboxylesterase Est30 from Geobacillus stearothermophilus as a template. The model covered most of the C-terminal part of EstD. The structure showed an alpha/beta-hydrolase fold and indicated the presence of a typical catalytic triad consisting of a serine, aspartate and histidine, which was verified by site-directed mutagenesis and inhibition studies. Phylogenetic analysis showed that EstD is only distantly related to other esterases. A comparison of the active site pentapeptide motifs revealed that EstD should be grouped into a new family of esterases (Family 10). EstD is the first characterized member of this family. PMID:17466017

  8. Discovery and characterization of a novel ATP/polyphosphate xylulokinase from a hyperthermophilic bacterium Thermotoga maritima.

    PubMed

    Martín del Campo, Julia S; Chun, You; Kim, Jae-Eung; Patiño, Rodrigo; Zhang, Y-H Percival

    2013-07-01

    Xylulokinase (XK, E.C. 2.7.1.17) is one of the key enzymes in xylose metabolism and it is essential for the activation of pentoses for the sustainable production of biocommodities from biomass sugars. The open reading frame (TM0116) from the hyperthermophilic bacterium Thermotoga maritima MSB8 encoding a putative xylulokinase were cloned and expressed in Escherichia coli BL21 Star (DE3) in the Luria-Bertani and auto-inducing high-cell-density media. The basic biochemical properties of this thermophilic XK were characterized. This XK has the optimal temperature of 85 °C. Under a suboptimal condition of 60 °C, the k cat was 83 s⁻¹, and the K(m) values for xylulose and ATP were 1.24 and 0.71 mM, respectively. We hypothesized that this XK could work on polyphosphate possibly because this ancestral thermophilic microorganism utilizes polyphosphate to regulate the Embden-Meyerhof pathway and its substrate-binding residues are somewhat similar to those of other ATP/polyphosphate-dependent kinases. This XK was found to work on low-cost polyphosphate, exhibiting 41 % of its specific activity on ATP. This first ATP/polyphosphate XK could have a great potential for xylose utilization in thermophilic ethanol-producing microorganisms and cell-free biosystems for low-cost biomanufacturing without the use of ATP.

  9. XX/XY System of Sex Determination in the Geophilomorph Centipede Strigamia maritima

    PubMed Central

    Green, Jack E.; Dalíková, Martina; Sahara, Ken; Marec, František; Akam, Michael

    2016-01-01

    We show that the geophilomorph centipede Strigamia maritima possesses an XX/XY system of sex chromosomes, with males being the heterogametic sex. This is, to our knowledge, the first report of sex chromosomes in any geophilomorph centipede. Using the recently assembled Strigamia genome sequence, we identified a set of scaffolds differentially represented in male and female DNA sequence. Using quantitative real-time PCR, we confirmed that three candidate X chromosome-derived scaffolds are present at approximately twice the copy number in females as in males. Furthermore, we confirmed that six candidate Y chromosome-derived scaffolds contain male-specific sequences. Finally, using this molecular information, we designed an X chromosome-specific DNA probe and performed fluorescent in situ hybridization against mitotic and meiotic chromosome spreads to identify the Strigamia XY sex-chromosome pair cytologically. We found that the X and Y chromosomes are recognizably different in size during the early pachytene stage of meiosis, and exhibit incomplete and delayed pairing. PMID:26919730

  10. XX/XY System of Sex Determination in the Geophilomorph Centipede Strigamia maritima.

    PubMed

    Green, Jack E; Dalíková, Martina; Sahara, Ken; Marec, František; Akam, Michael

    2016-01-01

    We show that the geophilomorph centipede Strigamia maritima possesses an XX/XY system of sex chromosomes, with males being the heterogametic sex. This is, to our knowledge, the first report of sex chromosomes in any geophilomorph centipede. Using the recently assembled Strigamia genome sequence, we identified a set of scaffolds differentially represented in male and female DNA sequence. Using quantitative real-time PCR, we confirmed that three candidate X chromosome-derived scaffolds are present at approximately twice the copy number in females as in males. Furthermore, we confirmed that six candidate Y chromosome-derived scaffolds contain male-specific sequences. Finally, using this molecular information, we designed an X chromosome-specific DNA probe and performed fluorescent in situ hybridization against mitotic and meiotic chromosome spreads to identify the Strigamia XY sex-chromosome pair cytologically. We found that the X and Y chromosomes are recognizably different in size during the early pachytene stage of meiosis, and exhibit incomplete and delayed pairing.

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

    PubMed

    Green, Jack E; Akam, Michael

    2014-08-15

    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.

  12. The centipede Strigamia maritima possesses a large complement of Wnt genes with diverse expression patterns.

    PubMed

    Hayden, Luke; Arthur, Wallace

    2014-05-01

    The genes of the Wnt family play important roles in the development of many animals. In the arthropods, these genes are known to have multiple functions, including roles in posterior development and segmentation. Despite this, secondary loss of Wnt genes is common among the Arthropoda. Unlike many arthropods, Strigamia maritima, a geophilomorph centipede, possesses a large complement of Wnt ligands, with 11 Wnt genes present. In this study, the expression of each of these genes was examined across a range of stages during embryonic development. The expression of Wnt genes in Strigamia displays much variability. Most Wnt genes are expressed in segmental stripes in the trunk; near the proctodeum; and in the head region. However, despite this overall broad similarity, there are many differences between the various Wnt genes in their exact patterns of expression. These data should be considered in the context of different hypotheses regarding the functional relationships between the Wnt genes and the degree of redundancy present in this system. The findings of this study are consistent with one particular model of Wnt activity, the combinatorial model, whereby the combination of Wnt ligands present in a particular region defines its identity. These findings should also be useful in attempts to reconstruct the evolutionary history of Wnt signaling in arthropods.

  13. A simple assay for determining activities of phosphopentomutase from a hyperthermophilic bacterium Thermotoga maritima.

    PubMed

    Moustafa, Hanan M A; Zaghloul, Taha I; Zhang, Y-H Percival

    2016-05-15

    Phosphopentomutase (PPM) catalyzes the interconversion of α-D-(deoxy)-ribose 1-phosphate and α-D-(deoxy)-ribose 5-phosphate. We developed a coupled or uncoupled enzymatic assay with an enzyme nucleoside phosphorylase for determining PPM activities on D-ribose 5-phosphate at a broad temperature range from 30 to 90 °C. This assay not only is simple and highly sensitive but also does not require any costly special instrument. Via this technology, an open reading frame TM0167 from a thermophilic bacterium Thermotoga maritima putatively encoding PPM was cloned. The recombinant PPM was overexpressed in Escherichia coli Rosetta. This enzyme has the highest activity at 90 °C. MnCl2 (0.1 mM) and 50 μM α-D-glucose 1,6-bisphosphate are cofactors. The kinetic parameters of Km and kcat are 1.2 mM and 185 s(-1) at 90 °C, respectively. The enzyme has a half-life time of up to 156 min at 90 °C. This enzyme is the most active and thermostable PPM reported to date. PMID:26924489

  14. Disentangling the causes of heterogeneity in male fecundity in gynodioecious Beta vulgaris ssp. maritima.

    PubMed

    De Cauwer, I; Arnaud, J-F; Klein, E K; Dufay, M

    2012-08-01

    Variation among individuals in reproductive success is advocated as a major process driving evolution of sexual polymorphisms in plants, such as gynodioecy where females and hermaphrodites coexist. In gynodioecious Beta vulgaris ssp. maritima, sex determination involves cytoplasmic male sterility (CMS) genes and nuclear restorers of male fertility. Both restored CMS and non-CMS hermaphrodites co-occur. Genotype-specific differences in male fitness are theoretically expected to explain the maintenance of cytonuclear polymorphism. Using genotypic information on seedlings and flowering plants within two metapopulations, we investigated whether male fecundity was influenced by ecological, phenotypic and genetic factors, while taking into account the shape and scale of pollen dispersal. Along with spatially restricted pollen flow, we showed that male fecundity was affected by flowering synchrony, investment in reproduction, pollen production and cytoplasmic identity of potential fathers. Siring success of non-CMS hermaphrodites was higher than that of restored CMS hermaphrodites. However, the magnitude of the difference in fecundity depended on the likelihood of carrying restorer alleles for non-CMS hermaphrodites. Our results suggest the occurrence of a cost of silent restorers, a condition supported by scarce empirical evidence, but theoretically required to maintain a stable sexual polymorphism in gynodioecious species.

  15. Food and feeding ecology of purple sandpipers Calidris maritima on rocky intertidal habitats (Helgoland, German Bight)

    NASA Astrophysics Data System (ADS)

    Dierschke, Volker

    On the island of Helgoland (German Bight) Purple Sandpipers Calidris maritima feed mainly in the intertidal of piers and rocky shores. The main prey species are Littorina saxatilis and Mytilus edulis, complemented by crustaceans, polychaetes, other molluscs and green algae. Beach habitats are used as alternative feeding sites during storms. Feeding sites seem to be selected according to rates of assimilated energy intake. The most profitable habitat (wrack beds on the high-tide line with kelp-fly larvae, 16.8 W) is used after arrival in October but is not available during winter. Because of high intake rates in rocky habitats (13.1 W on piers, 5.5 W on mussel beds), which allow short daily feeding times, and available alternative feeding sites during storms, Purple Sandpipers do not need to carry fat reserves in winter like other waders wintering in central and Western Europe. This, and the ever accessible food supply of epibenthic macrofauna on rocky shores, may enable Purple Sandpipers to winter further north than other wader species.

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

    PubMed

    Green, Jack E; Akam, Michael

    2014-08-15

    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

  17. The centipede Strigamia maritima possesses a large complement of Wnt genes with diverse expression patterns.

    PubMed

    Hayden, Luke; Arthur, Wallace

    2014-05-01

    The genes of the Wnt family play important roles in the development of many animals. In the arthropods, these genes are known to have multiple functions, including roles in posterior development and segmentation. Despite this, secondary loss of Wnt genes is common among the Arthropoda. Unlike many arthropods, Strigamia maritima, a geophilomorph centipede, possesses a large complement of Wnt ligands, with 11 Wnt genes present. In this study, the expression of each of these genes was examined across a range of stages during embryonic development. The expression of Wnt genes in Strigamia displays much variability. Most Wnt genes are expressed in segmental stripes in the trunk; near the proctodeum; and in the head region. However, despite this overall broad similarity, there are many differences between the various Wnt genes in their exact patterns of expression. These data should be considered in the context of different hypotheses regarding the functional relationships between the Wnt genes and the degree of redundancy present in this system. The findings of this study are consistent with one particular model of Wnt activity, the combinatorial model, whereby the combination of Wnt ligands present in a particular region defines its identity. These findings should also be useful in attempts to reconstruct the evolutionary history of Wnt signaling in arthropods. PMID:24754405

  18. XX/XY System of Sex Determination in the Geophilomorph Centipede Strigamia maritima.

    PubMed

    Green, Jack E; Dalíková, Martina; Sahara, Ken; Marec, František; Akam, Michael

    2016-01-01

    We show that the geophilomorph centipede Strigamia maritima possesses an XX/XY system of sex chromosomes, with males being the heterogametic sex. This is, to our knowledge, the first report of sex chromosomes in any geophilomorph centipede. Using the recently assembled Strigamia genome sequence, we identified a set of scaffolds differentially represented in male and female DNA sequence. Using quantitative real-time PCR, we confirmed that three candidate X chromosome-derived scaffolds are present at approximately twice the copy number in females as in males. Furthermore, we confirmed that six candidate Y chromosome-derived scaffolds contain male-specific sequences. Finally, using this molecular information, we designed an X chromosome-specific DNA probe and performed fluorescent in situ hybridization against mitotic and meiotic chromosome spreads to identify the Strigamia XY sex-chromosome pair cytologically. We found that the X and Y chromosomes are recognizably different in size during the early pachytene stage of meiosis, and exhibit incomplete and delayed pairing. PMID:26919730

  19. Temporal dynamics of sediment bacterial communities in monospecific stands of Juncus maritimus and Spartina maritima.

    PubMed

    Cleary, D F R; Polónia, A R M; Sousa, A I; Lillebø, A I; Queiroga, H; Gomes, N C M

    2016-09-01

    In the present study, we used 16S rRNA barcoded pyrosequencing to investigate to what extent monospecific stands of different salt marsh plant species (Juncus maritimus and Spartina maritima), sampling site and temporal variation affect sediment bacterial communities. We also used a bioinformatics tool, PICRUSt, to predict metagenome gene functional content. Our results showed that bacterial community composition from monospecific stands of both plant species varied temporally, but both host plant species maintained compositionally distinct communities of bacteria. Juncus sediment was characterised by higher abundances of Alphaproteobacteria, Myxococcales, Rhodospirillales, NB1-j and Ignavibacteriales, while Spartina sediment was characterised by higher abundances of Anaerolineae, Synechococcophycidae, Desulfobacterales, SHA-20 and Rhodobacterales. The differences in composition and higher taxon abundance between the sediment bacterial communities of stands of both plant species may be expected to affect overall metabolic diversity. In line with this expectation, there were also differences in the predicted enrichment of selected metabolic pathways. In particular, bacterial communities of Juncus sediment were predicted to be enriched for pathways related to the degradation of various (xenobiotic) compounds. Bacterial communities of Spartina sediment in turn were predicted to be enriched for pathways related to the biosynthesis of various bioactive compounds. Our study highlights the differences in composition and predicted functions of sediment-associated bacterial communities from two different salt marsh plant species. Loss of salt marsh habitat may thus be expected to both adversely affect microbial diversity and ecosystem functioning and have consequences for environmental processes such as nutrient cycling and pollutant remediation.

  20. 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

  1. Identification of a novel two component system in Thermotoga maritima. Complex stoichiometry and crystallization.

    PubMed

    Casino, Patricia; Fernández-Alvarez, Ana; Alfonso, Carlos; Rivas, Germán; Marina, Alberto

    2007-05-01

    Two-component signal transduction systems, comprised of histidine kinase and its cognate response regulator, are the predominant mechanism by which microorganisms sense and respond to changes in many different environmental conditions. Different Thermotoga maritima histidine kinases have been used as prototypes; among them, the orphan TM0853 has been presented as a structural model of class I histidine kinases. We used phosphotransfer assays to identify TM0468 as the partner response regulator of TM0853. Since full-length TM0853 can be produced as a soluble protein in Escherichia coli, it was used to analyze the union stoichiometry in an intact two-component system for the first time. We demonstrate that TM0853, or its cytoplasmic catalytic portion, form a 1:1 complex with TM0468 with native PAGE. The complex band is unique, even in the presence of an excess of each individual protein, indicating that the union is cooperative. We corroborated these findings by using ultracentrifugation assays. Therefore, we propose that the general mode of interaction in an orthodox two-component system may be the stoichiometric and cooperative complex between a dimeric histidine kinase and two response regulators. Finally, we have been able to produce protein crystals of the complex between the cytoplasmic portion of TM0853 and TM0468 that diffract to 2.8 A Bragg spacing.

  2. Flow cytometry and GISH reveal mixed ploidy populations and Spartina nonaploids with genomes of S. alterniflora and S. maritima origin

    PubMed Central

    Renny-Byfield, Simon; Ainouche, Malika; Leitch, Ilia J.; Lim, K. Yoong; Le Comber, Steven C.; Leitch, Andrew R.

    2010-01-01

    Background The genus Spartina exhibits extensive hybridization and includes classic examples of recent speciation by allopolyploidy. In the UK there are two hexaploid species, S. maritima and S. alterniflora, as well as the homoploid hybrid S. × townsendii (2n = 60) and a derived allododecaploid S. anglica (2n = 120, 122, 124); the latter two are considered to have originated in Hythe, southern England at the end of the 19th century. Methods Genomic in situ hybridization (GISH) and flow cytometry were used to characterize the genomic composition and distribution of these species and their ploidy levels at Eling Marchwood and Hythe, both near Southampton, southern England. Key Results GISH identified approx. 60 chromosomes each of S. maritima and S. alterniflora origin in S. anglica and 62 chromosomes from S. alterniflora and 30 chromosomes from S. maritima in a nonaploid individual from Eling Marchwood, UK. GISH and flow cytometry also revealed that most (94 %) individuals examined at Hythe were hexaploid (the remaining two individuals (6 %) were dodedcaploid; n = 34), whereas hexaploid (approx. 36 % of plants), nonaploid (approx. 27 %) and dodecaploid (approx. 36 %) individuals were found at Eling Marchwood (n = 22). Conclusions Nonaploid individuals indicate the potential for introgression between hexaploid and dodecaploid species, complicating the picture of polyploid-induced speciation within the genus. Despite the aggressive ecological habit of S. anglica, it has not out-competed S. × townsendii at Hythe (homoploid hybrids at a frequency of 94 %, n = 34), despite >100 years of coexistence. The success of GISH opens up the potential for future studies of polyploid-induced genome restructuring in this genus. PMID:20150197

  3. Different CMS sources found in Beta vulgaris ssp maritima: mitochondrial variability in wild populations revealed by a rapid screening procedure.

    PubMed

    Saumitou-Laprade, P; Rouwendal, G J; Cuguen, J; Krens, F A; Michaelis, G

    1993-01-01

    Mitochondrial DNA (mtDNA) variation in natural Beta maritima populations has been characterized by way of Southern blot hybridizations of total DNA using non-radioactive probes and chemiluminescent detection. It was found that the previously described N ("normal") mitochondrial type could be subdivided into three subtypes. A new mitochondrial genotype (type R) was distinguished in addition to the previously described type S. Both are male-sterile cytoplasms and can produce a. segregation of sexual phenotypes in their progenies depending on the nuclear background. The populations contained at least two to four different mitochondrial genotypes.

  4. An early temperature-sensitive period for the plasticity of segment number in the centipede Strigamia maritima.

    PubMed

    Vedel, Vincent; Apostolou, Zivkos; Arthur, Wallace; Akam, Michael; Brena, Carlo

    2010-01-01

    Geophilomorph centipedes show variation in segment number (a) between closely related species and (b) within and between populations of the same species. We have previously shown for a Scottish population of the coastal centipede Strigamia maritima that the temperature of embryonic development is one of the factors that affects the segment number of hatchlings, and hence of adults, as these animals grow epimorphically--that is, without postembryonic addition of segments. Here, we show, using temperature-shift experiments, that the main developmental period during which embryos are sensitive to environmental temperature is surprisingly early, during blastoderm formation and before, or very shortly after, the onset of segmentation.

  5. Enzymatic synthesis of rare sugars with L-rhamnulose-1-phosphate aldolase from Thermotoga maritima MSB8.

    PubMed

    Li, Zijie; Wu, Xiaoru; Cai, Li; Duan, Shenglin; Liu, Jia; Yuan, Peng; Nakanishi, Hideki; Gao, Xiao-Dong

    2015-09-15

    L-Rhamnulose-1-phosphate aldolase from a thermophilic source (Thermotoga maritima MSB8) (RhaDT.mari) was heterologously overexpressed in Escherichia coli and the stereoselectivity of this enzyme with or without Nus tag was investigated. We also applied this enzyme to the synthesis of rare sugars D-psicose, D-sorbose, L-tagatose and L-fructose using our one-pot four-enzyme system. To the best of our knowledge, this is the first use of RhaD from a thermophilic source for rare sugar synthesis and the temperature tolerance of this enzyme paves the path for large scale fermentation.

  6. Substrate specificities and expression patterns reflect the evolutionary divergence of maltose ABC transporters in Thermotoga maritima.

    PubMed

    Nanavati, Dhaval M; Nguyen, Tu N; Noll, Kenneth M

    2005-03-01

    Duplication of transporter genes is apparent in the genome sequence of the hyperthermophilic bacterium Thermotoga maritima. The physiological impacts of these duplications are not well understood, so we used the bacterium's two putative maltose transporters to begin a study of the evolutionary relationship between a transporter's function and the control of expression of its genes. We show that the substrate binding proteins encoded by these operons, MalE1 and MalE2, have different substrate specificities and affinities and that they are expressed under different growth conditions. MalE1 binds maltose (dissociation constant [KD], 24 +/- 1 microM), maltotriose (KD, 8 +/- 0.5 nM), and beta-(1-->4)-mannotetraose (KD, 38 +/- 1 microM). In contrast, MalE2 binds maltose (KD, 8.4 +/- 1 microM), maltotriose (KD, 11.5 +/- 1.5 microM), and trehalose (KD, 9.5 +/- 1.0 microM) confirming the findings of Wassenberg et al. (J. Mol. Biol. 295:279-288, 2000). Neither protein binds lactose. We examined the expression of these operons at both the transcriptional and translational levels and found that MalE1 is expressed in cells grown on lactose or guar gum and that MalE2 is highly expressed in starch- and trehalose-grown cells. Evidence is provided that malE1, malF1, and perhaps malG1 are cotranscribed and so constitute an operon. An open reading frame encoding a putative transcriptional regulatory protein adjacent to this operon (TM1200) is also up-regulated in response to growth on lactose. These evolutionarily related transporter operons have diverged both in function and expression to assume apparently different physiological roles. PMID:15743948

  7. Formylglycinamide Ribonucleotide Amidotransferase from Thermotoga maritima: Structural Insights into Complex Formation†‡

    PubMed Central

    2008-01-01

    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 (FGAM), ADP, Pi, and glutamate. Two forms of PurL have been characterized, large and small. Large PurL, present in most Gram-negative bacteria and eukaryotes, consists of a single polypeptide chain and contains three major domains: the N-terminal domain, the FGAM synthetase domain, and the glutaminase domain, with a putative ammonia channel located between the active sites of the latter two. Small PurL, present in Gram-positive bacteria and archaea, is structurally homologous to the FGAM synthetase domain of large PurL, and forms a complex with two additional gene products, PurQ and PurS. The structure of the PurS dimer is homologous with the N-terminal domain of large PurL, while PurQ, whose structure has not been reported, contains the glutaminase activity. In Bacillus subtilis, the formation of the PurLQS complex is dependent on glutamine and ADP and has been demonstrated by size-exclusion chromatography. In this work, a structure of the PurLQS complex from Thermotoga maritima is described revealing a 2:1:1 stoichiometry of PurS:Q:L, respectively. The conformational changes observed in TmPurL upon complex formation elucidate the mechanism of metabolite-mediated recruitment of PurQ and PurS. The flexibility of the PurS dimer is proposed to play a role in the activation of the complex and the formation of the ammonia channel. A potential path for the ammonia channel is identified. PMID:18597481

  8. Polymerization properties of the Thermotoga maritima actin MreB: roles of temperature, nucleotides, and ions.

    PubMed

    Bean, Greg J; Amann, Kurt J

    2008-01-15

    MreB is a bacterial orthologue of actin that affects cell shape, polarity, and chromosome segregation. Although a significant body of work has explored its cellular functions, we know very little about the biochemical behavior of MreB. We have cloned, overexpressed in Escherichia coli, and purified untagged MreB1 from Thermotoga maritima. We have characterized the conditions that regulate its monomer-to-polymer assembly reaction, the critical concentrations of that reaction, the manner in which MreB uses nucleotides, its stability, and the structure of the assembled polymer. MreB requires a bound purine nucleotide for polymerization and rapidly hydrolyzes it following assembly. MreB assembly contains two distinct components, one that does not require divalent cations and one that does, which may comprise the nucleation and elongation phases of assembly, respectively. MreB assembly is strongly favored by increasing temperature or protein concentration but inhibited differentially by high concentrations of monovalent salts. The polymerization rate increases and the bulk critical concentration decreases with increasing temperature, but in contrast to previous reports, MreB is capable of polymerizing across a broad range of temperatures. MreB polymers are shorter and stiffer and scatter more light than eukaryotic actin filaments. Due to rapid ATP hydrolysis and phosphate release, we suggest that most assembled MreB in cells is in the ADP-bound state. Because of only moderate differences between the ATP and ADP critical concentrations, treadmilling may occur, but we do not predict dynamic instability in cells. Because of the relatively low cellular concentration of MreB and the observed structural properties of the polymer, a single MreB assembly may exist in cells.

  9. 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.

  10. Molecular and biochemical characterization of bifunctional pyruvate decarboxylases and pyruvate ferredoxin oxidoreductases from Thermotoga maritima and Thermotoga hypogea.

    PubMed

    Eram, Mohammad S; Wong, Alton; Oduaran, Erica; Ma, Kesen

    2015-12-01

    Hyperthermophilic bacteria Thermotoga maritima and Thermotoga hypogea produce ethanol as a metabolic end product, which is resulted from acetaldehyde reduction catalysed by an alcohol dehydrogenase (ADH). However, the enzyme that is involved in the production of acetaldehyde from pyruvate is not well characterized. An oxygen sensitive and coenzyme A-dependent pyruvate decarboxylase (PDC) activity was found to be present in cell free extracts of T. maritima and T. hypogea. Both enzymes were purified and found to have pyruvate ferredoxin oxidoreductase (POR) activity, indicating their bifunctionality. Both PDC and POR activities from each of the purified enzymes were characterized in regards to their optimal assay conditions including pH dependency, oxygen sensitivity, thermal stability, temperature dependency and kinetic parameters. The close relatedness of the PORs that was shown by sequence analysis could be an indication of the presence of such bifunctionality in other hyperthermophilic bacteria. This is the first report of a bifunctional PDC/POR enzyme in hyperthermophilic bacteria. The PDC and the previously reported ADHs are most likely the key enzymes catalysing the production of ethanol from pyruvate in bacterial hyperthermophiles.

  11. Armeria maritima from a calamine heap--initial studies on physiologic-metabolic adaptations to metal-enriched soil.

    PubMed

    Olko, A; Abratowska, A; Zyłkowska, J; Wierzbicka, M; Tukiendorf, A

    2008-02-01

    Plants of Armeria maritima are found both on unpolluted sites and on soils strongly polluted with heavy metals. Seedlings of A. maritima from a zinc-lead calamine heap in ore-mining region (Bolesław population) and from unpolluted area (Manasterz population) were tested to determine the zinc, cadmium and lead tolerance. In hydroponic experiments Bolesław population was more tolerant to zinc, cadmium and lead. Localization of heavy metals in roots was determined using the histochemical method for detecting metal-complexes with dithizone. Their accumulation was found in root hairs, rhizoderma and at the surface of the central cylinder. Glutathione level in plants increased after metal treatment of both populations. However, its high level was not correlated with phytochelatin production. These metal-binding complexes were not detected in plants exposed to zinc, cadmium or lead. Changes of organic acids concentrations in Armeria treated with metals may suggest their role in metal translocation from roots to shoots. The content of organic acids, especially malate, decreased in the roots and increased in the leaves. These changes may be important in Pb-tolerance of Manasterz population and in Zn-, Cd-tolerance of calamine population from Bolesław.

  12. The crystal structure of triosephosphate isomerase (TIM) from Thermotoga maritima: a comparative thermostability structural analysis of ten different TIM structures.

    PubMed

    Maes, D; Zeelen, J P; Thanki, N; Beaucamp, N; Alvarez, M; Thi, M H; Backmann, J; Martial, J A; Wyns, L; Jaenicke, R; Wierenga, R K

    1999-11-15

    The molecular mechanisms that evolution has been employing to adapt to environmental temperatures are poorly understood. To gain some further insight into this subject we solved the crystal structure of triosephosphate isomerase (TIM) from the hyperthermophilic bacterium Thermotoga maritima (TmTIM). The enzyme is a tetramer, assembled as a dimer of dimers, suggesting that the tetrameric wild-type phosphoglycerate kinase PGK-TIM fusion protein consists of a core of two TIM dimers covalently linked to 4 PGK units. The crystal structure of TmTIM represents the most thermostable TIM presently known in its 3D-structure. It adds to a series of nine known TIM structures from a wide variety of organisms, spanning the range from psychrophiles to hyperthermophiles. Several properties believed to be involved in the adaptation to different temperatures were calculated and compared for all ten structures. No sequence preferences, correlated with thermal stability, were apparent from the amino acid composition or from the analysis of the loops and secondary structure elements of the ten TIMs. A common feature for both psychrophilic and T. maritima TIM is the large number of salt bridges compared with the number found in mesophilic TIMs. In the two thermophilic TIMs, the highest amount of accessible hydrophobic surface is buried during the folding and assembly process.

  13. Modulation of superoxide dismutase (SOD) isozymes by organ development and high long-term salinity in the halophyte Cakile maritima.

    PubMed

    Houmani, Hayet; Rodríguez-Ruiz, Marta; Palma, José M; Abdelly, Chedly; Corpas, Francisco J

    2016-05-01

    Superoxide dismutase (SOD) activity catalyzes the disproportionation of superoxide radicals into hydrogen peroxide and oxygen. This enzyme is considered to be a first line of defense for controlling the production of reactive oxygen species (ROS). In this study, the number and type of SOD isozymes were identified in the principal organs (roots, stems, leaves, flowers, and seeds) of Cakile maritima. We also analyzed the way in which the activity of these SOD isozymes is modulated during development and under high long-term salinity (400 mM NaCl) stress conditions. The data indicate that this plant contains a total of ten SOD isozymes: two Mn-SODs, one Fe-SOD, and seven CuZn-SODs, with the Fe-SOD being the most prominent isozyme in the different organs analyzed. Moreover, the modulation of SOD isozymes, particularly CuZn-SODs, was only detected during development and under severe salinity stress conditions. These data suggest that, in C. maritima, the occurrence of these CuZn-SODs in roots and leaves plays an adaptive role since this CuZn-SOD isozyme might replace the diminished Fe-SOD activity under salinity stress to overcome this adverse environmental condition. PMID:26159565

  14. Anthelmintic activity of Artemisia vestita Wall ex DC. and Artemisia maritima L. against Haemonchus contortus from sheep.

    PubMed

    Irum, Shamaila; Ahmed, Haroon; Mukhtar, Muhammad; Mushtaq, Muhammad; Mirza, Bushra; Donskow-Łysoniewska, Katarzyna; Qayyum, Mazhar; Simsek, Sami

    2015-09-15

    Current study was designed to evaluate in vivo and in vitro anthelmintic activity of Artemisia vestita Wall ex DC. and Artemisia maritima L. against Haemonchus contortus in comparison with ivermectin to investigate the effect of plant extracts on survival of infective L3 and adults under in vitro condition. Plant extracts were given to H. contortus infected sheep orally and it was infected with L3 stage of H. contortus at dose of 5000 larvae/sheep. Total of 25-30 larvae were incubated with plant extracts in PBS alone and ivermectin at different concentration used as positive control. It was recorded that there is a significant decrease in fecal egg count (FEC) after post-treatment period for both plants. The highest fecal egg count reduction for A. vestita was 87.2% at 100mg/kg while for A. maritima it was 84.5% on day 28 post-treatment. Investigated extracts indicated significant activity against larvae and adult worms.

  15. The MurE synthetase from Thermotoga maritima is endowed with an unusual D-lysine adding activity.

    PubMed

    Boniface, Audrey; Bouhss, Ahmed; Mengin-Lecreulx, Dominique; Blanot, Didier

    2006-06-01

    The peptidoglycan of Thermotoga maritima, an extremely thermophilic eubacterium, was shown to contain no diaminopimelic acid and approximate amounts of both enantiomers of lysine (Huber, R., Langworthy, T. A., König, H., Thomm, M., Woese, C. R., Sleytr, U. B., and Stetter, K. O. (1986) Arch. Microbiol. 144, 324-333). To assess the possible involvement of the MurE activity in the incorporation of D-lysine, the murE gene from this organism was cloned in Escherichia coli, and the corresponding protein was purified as the C-terminal His6-tagged form. In vitro assays showed that D-lysine and meso-diaminopimelic acid were added to UDP-N-acetylmuramoyl-dipeptide with 25 and 10% efficiencies, respectively, relative to L-lysine. The purified enzyme was used to synthesize the L- and D-lysine-containing UDP-N-acetylmuramoyl-tripeptides; chemical analysis revealed an unusual structure for the D-lysine-containing nucleotide, namely acylation of the epsilon-amino function of D-lysine by the D-glutamyl residue. In vitro assays with MurF and MraY enzymes from T. maritima showed that this novel nucleotide was not a substrate for MurF but that it could be directly processed into tripeptide lipid I by MraY, thereby substantiating the role of MurE in the incorporation of D-lysine into peptidoglycan.

  16. Overexpression, crystallization and preliminary X-ray crystallographic analysis of β-N-acetylglucosaminidase from Thermotoga maritima encoded by the Tm0809 gene.

    PubMed

    Lee, Hyung Ho; Jung, Sang Taek

    2013-02-01

    β-N-acetylglucosaminidase (NagA) protein hs a chitin-degrading activity and chitin is one of the most abundant polymers in nature. NagA contains a family 3 glycoside (GH3)-type N-terminal domain and a unique C-terminal domain. The structurally uncharacterized C-terminal domain of NagA may be involved in substrate specificity. To provide a structural basis for the substrate specificity of NagA, structural analysis of NagA from Thermotoga maritima encoded by the Tm0809 gene was initiated. NagA from T. maritima has been overexpressed in Escherichia coli and crystallized at 296 K using ammonium sulfate as a precipitant. Crystals of T. maritima NagA diffracted to 3.80 Å resolution and belonged to the monoclinic space group C2, with unit-cell parameters a = 231.15, b = 133.62, c = 140.88 Å, β = 89.97°. The crystallization of selenomethionyl-substituted protein is in progress to solve the crystal structure of T. maritima NagA.

  17. Draft Genome Sequence of Ardenticatena maritima 110S, a Thermophilic Nitrate- and Iron-Reducing Member of the Chloroflexi Class Ardenticatenia

    PubMed Central

    Ward, Lewis M.; Pace, Laura A.; Fischer, Woodward W.

    2015-01-01

    We report here the draft genome sequence of Ardenticatena maritima 110S, the first sequenced member of class Ardenticatenia of the phylum Chloroflexi. This thermophilic organism is capable of a range of physiologies, including aerobic respiration and iron reduction. It also encodes a complete denitrification pathway with a novel nitric oxide reductase. PMID:26586887

  18. Putative free radical-scavenging activity of an extract of Cineraria maritima in preventing selenite-induced cataractogenesis in Wistar rat pups

    PubMed Central

    Anitha, Thirugnanasambandhar Sivasubramanian; Muralidharan, Arumugam Ramachandran; Annadurai, Thangaraj; Jesudasan, Christdas Arul Nelson; Thomas, Philip Aloysius

    2013-01-01

    Purpose To investigate the possible free radical-scavenging activity of an extract of Cineraria maritima on selenite-induced cataractous lenses in Wistar rat pups. Methods In the present study, Wistar rat pups were divided into three experimental groups. On P10, Group I (control) rat pups received an intraperitoneal injection of 0.89% saline. Rats in groups II (selenite-challenged, untreated) and III (selenite-challenged, C. maritima treated) received a subcutaneous injection of sodium selenite (19 μmol/kg bodyweight); Group III rat pups also received an intraperitoneal injection of the extract of C. maritima (350 mg/kg bodyweight) once daily P9–14. Both eyes of each pup were examined from P16 until P30. Cytochemical localization of nitroblue tetrazolium salts and generation of superoxide, hydroxyl, and nitric oxide levels were measured. The expression of the inducible nitric oxide synthase gene was evaluated with reverse transcription-PCR. Immunoblot analysis was also performed to confirm the differential expression of the inducible nitric oxide synthase protein. Results Subcutaneous injection of sodium selenite led to severe oxidative damage in the lenticular tissues, shown by increased formation of formazan crystals, elevated generation of superoxide, hydroxyl, and nitric oxide radicals, and elevated inducible nitric oxide synthase gene and protein expression that possibly contributed to the opacification of the lens and thus cataract formation. When rat pups were treated with intraperitoneal administration of the extract of C. maritima, the generation of free radicals as well as the messenger ribonucleic acid and protein expression of inducible nitric oxide synthase were maintained at near normal levels. Conclusions The data generated by this study suggest that an ethanolic extract of C. maritima possibly prevents cataractogenesis in a rat model by minimizing free radical generation. PMID:24357923

  19. The effect of macrofauna, meiofauna and microfauna on the degradation of Spartina maritima detritus from a salt marsh area

    NASA Astrophysics Data System (ADS)

    Lillebø, Ana Isabel; Flindt, Mogens R.; Pardal, Miguel Ângelo; Marques, João Carlos

    1999-07-01

    Decomposition of salt marsh plants results from physical, chemical and biological processes including abiotic and biotic fragmentation, microbial decay and chemical transformation. According to literature data, only a few species have the ability to feed directly on living plant material, so fungi and bacteria seem to be the principal competitors for the organic substrates. Nevertheless, by consuming bacteria, protists and fungi associated to the detritus, macrofauna and meiofauna recycle the incorporated nutrients. Moreover, this nutrient regeneration may be seen as an effective factor in maintaining and stimulating bacterial production. In fact, it is well known that many detritus feeding species have very low assimilation efficiencies. The objective of the present study was to compare the nutrient mass balance of carbon; nitrogen and phosphorus in Spartina maritima covered areas and bare bottom sediment, with and without contribution of macrofauna, meiofauna and microbial populations. Nutrients mass balance was studied taking into account the initial and final nutrient concentrations in the sediment, water and plant material. Faunal activity was measured as a function of remineralised carbon, nitrogen and phosphorus. The experimental set-up included sixteen sub-experiments, which varied with respect to type of fauna, plant biomass and oxic status. Each sub-experiment was performed in small glass containers (3 L) containing about 900 g wwt sediment and 2.5 L estuarine water. Plant material, cut from intact plants, sediment cores and estuarine water were brought from the southern arm of the Mondego estuary (Portugal). The results showed that although the bacterial activity was responsible for the Spartina maritima degradation, the presence of meiofauna and macrofauna significantly enhanced the process. Moreover, the presence of Spartina maritima positively affected the mineralisation of the sediment carbon and nitrogen, especially when the three faunal components

  20. In vivo selection for the enhancement of Thermotoga maritima exopolygalacturonase activity at neutral pH and low temperature.

    PubMed

    Drone, Jullien; Dion, Michel; Tellier, Charles; Rabiller, Claude

    2007-01-01

    The aim of this study was to develop an Escherichia coli-based metabolic selection system for the uncovering of new oligogalacturonate-active enzymes. Based on the expression of the specific permease TogMNAB, this system enabled the entry of oligogalacturonates into the cytoplasm of E. coli thus providing a modified strain usable for this purpose. This tool was used for the metabolic selection of Thermotoga maritima exopolygalacturonase (TmGalU) mutants enabling the uptake of sodium trigalacturonate as the sole carbon source by the bacterium. In only one round of error-prone PCR and selection, mutants of TmGalU with a 4-fold increased turnover at pH 7.0 and 2-fold more active at 37 degrees C than wild-type enzyme were isolated. These results show the versatility of this strain for the evolution of oligogalacturonate-active enzymes.

  1. Cyclocoelid ( Morishitium sp.) Trematodes from an Air Sac of a Purple Sandpiper, Calidris maritima (Brünnich).

    PubMed

    Shutler, Dave; Mallory, Mark L; Elderkin, Mark; McLaughlin, J Daniel

    2016-06-01

    Like many shorebirds, purple sandpipers ( Calidris maritima [Brünnich] Charadriiformes: Scolopacidae) have experienced population declines in recent years, but causes of these declines have not been established. As part of a larger study to identify causes of these declines, we collected and examined 25 purple sandpipers in coastal Nova Scotia, Canada during March 2013. In the course of dissections to collect tissue samples, we detected a cluster of trematodes in the air sac of 1 bird that were subsequently identified as cyclocoelids belonging to the genus Morishitium Witenberg, 1928, which we believe is the first report of this genus of parasites in this host. Cyclocoelids have been reported from other scolopacids and other shorebird families, but we are unaware of reports of serious pathology arising from these trematodes. Given this and the low prevalence (4%) in our sample, our data cannot ascribe declines in purple sandpiper populations to these trematodes, but our sample is limited both spatially and temporally. PMID:26779884

  2. Crystallization and preliminary X-ray diffraction analysis of the S-adenosylhomocysteine hydrolase (SAHH) from Thermotoga maritima

    PubMed Central

    He, Miao; Zheng, Yingying; Huang, Chun-Hsiang; Qian, Guojun; Xiao, Xiansha; Ko, Tzu-Ping; Shao, Weilan; Guo, Rey-Ting

    2014-01-01

    S-Adenosylhomocysteine hydrolase (SAHH) catalyzes the reversible conversion of S-adenosylhomocysteine into adenosine and homocysteine. The SAHH from Thermotoga maritima (TmSAHH) was expressed in Escherichia coli and the recombinant protein was purified and crystallized. TmSAHH crystals belonging to space group C2, with unit-cell parameters a = 106.3, b = 112.0, c = 164.9 Å, β = 103.5°, were obtained by the sitting-drop vapour-diffusion method and diffracted to 2.85 Å resolution. Initial phase determination by molecular replacement clearly indicated that the crystal contains one homotetramer per asymmetric unit. Further refinement of the crystal structure is in progress. PMID:25372832

  3. Preliminary X-ray crystallographic analysis of tRNA pseudouridine 55 synthase from the thermophilic eubacterium Thermotoga maritima.

    PubMed

    Wouters, Johan; Tricot, Catherine; Durbecq, Virginie; Roovers, Martine; Stalon, Victor; Droogmans, Louis

    2003-01-01

    Thermotoga maritima TruB, an enzyme responsible for the formation of pseudouridine in tRNA, has been purified and crystallized by the hanging-drop vapour-diffusion method in 100 mM citrate pH 3.5, 200 mM Li(2)SO(4), 20% glycerol, 13% PEG 8000. Crystals display orthorhombic symmetry, with unit-cell parameters a = 47.39, b = 83.88, c = 98.72 A, and diffract to 2.0 A resolution using synchrotron radiation. A solution was obtained by molecular replacement using part of the recently published crystal structure of Escherichia coli TruB bound to a synthetic RNA.

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

    PubMed

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

    2006-06-01

    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.

  5. Active Site Metal Occupancy and Cyclic Di-GMP Phosphodiesterase Activity of Thermotoga maritima HD-GYP.

    PubMed

    Miner, Kyle D; Kurtz, Donald M

    2016-02-16

    HD-GYPs make up a subclass of the metal-dependent HD phosphohydrolase superfamily and catalyze conversion of cyclic di(3',5')-guanosine monophosphate (c-di-GMP) to 5'-phosphoguanylyl-(3'→5')-guanosine (pGpG) and GMP. Until now, the only reported crystal structure of an HD-GYP that also exhibits c-di-GMP phosphodiesterase activity contains a His/carboxylate ligated triiron active site. However, other structural and phylogenetic correlations indicate that some HD-GYPs contain dimetal active sites. Here we provide evidence that an HD-GYP c-di-GMP phosphodiesterase, TM0186, from Thermotoga maritima can accommodate both di- and trimetal active sites. We show that an as-isolated iron-containing TM0186 has an oxo/carboxylato-bridged diferric site, and that the reduced (diferrous) form is necessary and sufficient to catalyze conversion of c-di-GMP to pGpG, but that conversion of pGpG to GMP requires more than two metals per active site. Similar c-di-GMP phosphodiesterase activities were obtained with divalent iron or manganese. On the basis of activity correlations with several putative metal ligand residue variants and molecular dynamics simulations, we propose that TM0186 can accommodate both di- and trimetal active sites. Our results also suggest that a Glu residue conserved in a subset of HD-GYPs is required for formation of the trimetal site and can also serve as a labile ligand to the dimetal site. Given the anaerobic growth requirement of T. maritima, we suggest that this HD-GYP can function in vivo with either divalent iron or manganese occupying di- and trimetal sites.

  6. The elucidation of the structure of Thermotoga maritima peptidoglycan reveals two novel types of cross-link.

    PubMed

    Boniface, Audrey; Parquet, Claudine; Arthur, Michel; Mengin-Lecreulx, Dominique; Blanot, Didier

    2009-08-14

    Thermotoga maritima is a Gram-negative, hyperthermophilic bacterium whose peptidoglycan contains comparable amounts of L- and D-lysine. We have determined the fine structure of this cell-wall polymer. The muropeptides resulting from the digestion of peptidoglycan by mutanolysin were separated by high-performance liquid chromatography and identified by amino acid analysis after acid hydrolysis, dinitrophenylation, enzymatic determination of the configuration of the chiral amino acids, and mass spectrometry. The high-performance liquid chromatography profile contained four main peaks, two monomers, and two dimers, plus a few minor peaks corresponding to anhydro forms. The first monomer was the d-lysine-containing disaccharide-tripeptide in which the D-Glu-D-Lys bond had the unusual gamma-->epsilon arrangement (GlcNAc-MurNAc-L-Ala-gamma-D-Glu-epsilon-D-Lys). The second monomer was the conventional disaccharide-tetrapeptide (GlcNAc-MurNAc-L-Ala-gamma-D-Glu-L-Lys-D-Ala). The first dimer contained a disaccharide-L-Ala as the acyl donor cross-linked to the alpha-amine of D-Lys in a tripeptide acceptor stem with the sequence of the first monomer. In the second dimer, donor and acceptor stems with the sequences of the second and first monomers, respectively, were connected by a D-Ala4-alpha-D-Lys3 cross-link. The cross-linking index was 10 with an average chain length of 30 disaccharide units. The structure of the peptidoglycan of T. maritima revealed for the first time the key role of D-Lys in peptidoglycan synthesis, both as a surrogate of L-Lys or meso-diaminopimelic acid at the third position of peptide stems and in the formation of novel cross-links of the L-Ala1(alpha-->alpha)D-Lys3 and D-Ala4(alpha-->alpha)D-Lys3 types.

  7. 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

  8. 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

  9. Periplasmic Binding Proteins in Thermophiles: Characterization and Potential Application of an Arginine-Binding Protein from Thermotoga maritima: A Brief Thermo-Story.

    PubMed

    Ausili, Alessio; Staiano, Maria; Dattelbaum, Jonathan; Varriale, Antonio; Capo, Alessandro; D'Auria, Sabato

    2013-01-01

    Arginine-binding protein from the extremophile Thermotoga maritima is a 27.7 kDa protein possessing the typical two-domain structure of the periplasmic binding proteins family. The protein is characterized by a very high specificity and affinity to bind to arginine, also at high temperatures. Due to its features, this protein could be taken into account as a potential candidate for the design of a biosensor for arginine. It is important to investigate the stability of proteins when they are used for biotechnological applications. In this article, we review the structural and functional features of an arginine-binding protein from the extremophile Thermotoga maritima with a particular eye on its potential biotechnological applications. PMID:25371336

  10. Spatial genetic structure in Beta vulgaris subsp. maritima and Beta macrocarpa reveals the effect of contrasting mating system, influence of marine currents, and footprints of postglacial recolonization routes.

    PubMed

    Leys, Marie; Petit, Eric J; El-Bahloul, Yasmina; Liso, Camille; Fournet, Sylvain; Arnaud, Jean-François

    2014-05-01

    Understanding the factors that contribute to population genetic divergence across a species' range is a long-standing goal in evolutionary biology and ecological genetics. We examined the relative importance of historical and ecological features in shaping the present-day spatial patterns of genetic structure in two related plant species, Beta vulgaris subsp. maritima and Beta macrocarpa. Using nuclear and mitochondrial markers, we surveyed 93 populations from Brittany (France) to Morocco - the southern limit of their species' range distribution. Whereas B. macrocarpa showed a genotypic structure and a high level of genetic differentiation indicative of selfing, the population genetic structure of B. vulgaris subsp. maritima was consistent with an outcrossing mating system. We further showed (1) a strong geographic clustering in coastal B. vulgaris subsp. maritima populations that highlighted the influence of marine currents in shaping different lineages and (2) a peculiar genetic structure of inland B. vulgaris subsp. maritima populations that could indicate the admixture of distinct evolutionary lineages and recent expansions associated with anthropogenic disturbances. Spatial patterns of nuclear diversity and differentiation also supported a stepwise recolonization of Europe from Atlantic-Mediterranean refugia after the last glacial period, with leading-edge expansions. However, cytoplasmic diversity was not impacted by postglacial recolonization: stochastic long-distance seed dispersal mediated by major oceanic currents may mitigate the common patterns of reduced cytoplasmic diversity observed for edge populations. Overall, the patterns we documented here challenge the general view of reduced genetic diversity at the edge of a species' range distribution and provide clues for understanding how life-history and major geographic features interact to shape the distribution of genetic diversity.

  11. Spatial genetic structure in Beta vulgaris subsp. maritima and Beta macrocarpa reveals the effect of contrasting mating system, influence of marine currents, and footprints of postglacial recolonization routes

    PubMed Central

    Leys, Marie; Petit, Eric J; El-Bahloul, Yasmina; Liso, Camille; Fournet, Sylvain; Arnaud, Jean-François

    2014-01-01

    Understanding the factors that contribute to population genetic divergence across a species' range is a long-standing goal in evolutionary biology and ecological genetics. We examined the relative importance of historical and ecological features in shaping the present-day spatial patterns of genetic structure in two related plant species, Beta vulgaris subsp. maritima and Beta macrocarpa. Using nuclear and mitochondrial markers, we surveyed 93 populations from Brittany (France) to Morocco – the southern limit of their species' range distribution. Whereas B. macrocarpa showed a genotypic structure and a high level of genetic differentiation indicative of selfing, the population genetic structure of B. vulgaris subsp. maritima was consistent with an outcrossing mating system. We further showed (1) a strong geographic clustering in coastal B. vulgaris subsp. maritima populations that highlighted the influence of marine currents in shaping different lineages and (2) a peculiar genetic structure of inland B. vulgaris subsp. maritima populations that could indicate the admixture of distinct evolutionary lineages and recent expansions associated with anthropogenic disturbances. Spatial patterns of nuclear diversity and differentiation also supported a stepwise recolonization of Europe from Atlantic-Mediterranean refugia after the last glacial period, with leading-edge expansions. However, cytoplasmic diversity was not impacted by postglacial recolonization: stochastic long-distance seed dispersal mediated by major oceanic currents may mitigate the common patterns of reduced cytoplasmic diversity observed for edge populations. Overall, the patterns we documented here challenge the general view of reduced genetic diversity at the edge of a species' range distribution and provide clues for understanding how life-history and major geographic features interact to shape the distribution of genetic diversity. PMID:24963380

  12. Haplotype Detection from Next-Generation Sequencing in High-Ploidy-Level Species: 45S rDNA Gene Copies in the Hexaploid Spartina maritima

    PubMed Central

    Boutte, Julien; Aliaga, Benoît; Lima, Oscar; Ferreira de Carvalho, Julie; Ainouche, Abdelkader; Macas, Jiri; Rousseau-Gueutin, Mathieu; Coriton, Olivier; Ainouche, Malika; Salmon, Armel

    2015-01-01

    Gene and whole-genome duplications are widespread in plant nuclear genomes, resulting in sequence heterogeneity. Identification of duplicated genes may be particularly challenging in highly redundant genomes, especially when there are no diploid parents as a reference. Here, we developed a pipeline to detect the different copies in the ribosomal RNA gene family in the hexaploid grass Spartina maritima from next-generation sequencing (Roche-454) reads. The heterogeneity of the different domains of the highly repeated 45S unit was explored by identifying single nucleotide polymorphisms (SNPs) and assembling reads based on shared polymorphisms. SNPs were validated using comparisons with Illumina sequence data sets and by cloning and Sanger (re)sequencing. Using this approach, 29 validated polymorphisms and 11 validated haplotypes were reported (out of 34 and 20, respectively, that were initially predicted by our program). The rDNA domains of S. maritima have similar lengths as those found in other Poaceae, apart from the 5′-ETS, which is approximately two-times longer in S. maritima. Sequence homogeneity was encountered in coding regions and both internal transcribed spacers (ITS), whereas high intragenomic variability was detected in the intergenic spacer (IGS) and the external transcribed spacer (ETS). Molecular cytogenetic analysis by fluorescent in situ hybridization (FISH) revealed the presence of one pair of 45S rDNA signals on the chromosomes of S. maritima instead of three expected pairs for a hexaploid genome, indicating loss of duplicated homeologous loci through the diploidization process. The procedure developed here may be used at any ploidy level and using different sequencing technologies. PMID:26530424

  13. Structure-Based Design of Robust Glucose Biosensors using a Thermotoga maritima Periplasmic Glucose-Binding Protein

    SciTech Connect

    Tian,Y.; Cunco, M.; Changela, A.; Hocker, B.; Beese, L.; Hellinga, H.

    2007-01-01

    We report the design and engineering of a robust, reagentless fluorescent glucose biosensor based on the periplasmic glucose-binding protein obtained from Thermotoga maritima (tmGBP). The gene for this protein was cloned from genomic DNA and overexpressed in Escherichia coli, the identity of its cognate sugar was confirmed, ligand binding was studied, and the structure of its glucose complex was solved to 1.7 Angstroms resolution by X-ray crystallography. TmGBP is specific for glucose and exhibits high thermostability (midpoint of thermal denaturation is 119 {+-} 1 C and 144 {+-} 2 C in the absence and presence of 1 mM glucose, respectively). A series of fluorescent conjugates was constructed by coupling single, environmentally sensitive fluorophores to unique cysteines introduced by site-specific mutagenesis at positions predicted to be responsive to ligand-induced conformational changes based on the structure. These conjugates were screened to identify engineered tmGBPs that function as reagentless fluorescent glucose biosensors. The Y13C Cy5 conjugate is bright, gives a large response to glucose over concentration ranges appropriate for in vivo monitoring of blood glucose levels (1-30 mM), and can be immobilized in an orientation-specific manner in microtiter plates to give a reversible response to glucose. The immobilized protein retains its response after long-term storage at room temperature.

  14. 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.

  15. Sex-specific fitness variation in gynodioecious Beta vulgaris ssp. maritima: do empirical observations fit theoretical predictions?

    PubMed

    De Cauwer, I; Arnaud, J-F; Courseaux, A; Dufay, M

    2011-11-01

    In gynodioecious species, in which hermaphroditic and female plants co-occur, the maintenance of sexual polymorphism relies on the genetic determination of sex and on the relative fitness of the different phenotypes. Flower production, components of male fitness (pollen quantity and pollen quality) and female fitness (fruit and seed set) were measured in gynodioecious Beta vulgaris spp. maritima, in which sex is determined by interactions between cytoplasmic male sterility (CMS) genes and nuclear restorers of male fertility. The results suggested that (i) female had a marginal advantage over hermaphrodites in terms of flower production only, (ii) restored CMS hermaphrodites (carrying both CMS genes and nuclear restorers) suffered a slight decrease in fruit production compared to non-CMS hermaphrodites and (iii) restored CMS hermaphrodites were poor pollen producers compared to non-CMS hermaphrodites, probably as a consequence of complex determination of restoration. These observations potentially have important consequences for the conditions of maintenance of sexual polymorphism in B. vulgaris and are discussed in the light of existing theory on evolutionary dynamics of gynodioecy.

  16. Evolutionary change in flowering phenology in the iteroparous herb Beta vulgaris ssp. maritima: a search for the underlying mechanisms.

    PubMed

    Van Dijk, Henk

    2009-01-01

    The potential for evolutionary change in flowering time has gained considerable attention in view of the current global climate change. To explore this potential and its underlying mechanisms in the iteroparous perennial Beta vulgaris ssp. maritima (sea beet), artificial selection for earlier and later flowering date was applied under semi-natural greenhouse conditions. Mean flowering date occurred more than 30 d earlier in 13 generations in the early selection line, but response was weaker in the late selection line. Taking advantage of the growing knowledge on the genetics and the physiology of flowering induction, particularly in Arabidopsis thaliana, the results obtained here were analysed in terms of the four different pathways of flowering induction known in this species. A first significant correlated response was stem elongation (bolting) in the vegetative stage, suggesting that plants were thus able to flower earlier as long as other requirements were satisfied. Vernalization had a clear influence on flowering date and its influence increased during the selection process, together with sensitivity to photoperiod. Vernalization and photoperiod could compensate for each other: each additional week of vernalization at 5 degrees C decreased the necessary daylength for flowering by about 15 min during the later selection stages, while in unselected plants, it was about 7 min. Devernalizing effects were observed at short days combined with higher temperatures. Special attention was given to the role of the B (bolting) gene that cancels the vernalization requirement. The results here obtained suggest that all four known pathways may simultaneously participate in evolutionary change.

  17. Transcriptomic profiling of the salt stress response in excised leaves of the halophyte Beta vulgaris ssp. maritima.

    PubMed

    Skorupa, Monika; Gołębiewski, Marcin; Domagalski, Krzysztof; Kurnik, Katarzyna; Abu Nahia, Karim; Złoch, Michał; Tretyn, Andrzej; Tyburski, Jarosław

    2016-02-01

    Beta vulgaris ssp. maritima is a halophytic relative of cultivated beets. In the present work a transcriptome response to acute salt stress imposed to excised leaves of sea beet was investigated. Salt treatments consisted of adding NaCl directly to the transpiration stream by immersing the petioles of excised leaves into the salt solutions. Sequencing libraries were generated from leaves subjected to either moderate or strong salt stress. Control libraries were constructed from untreated leaves. Sequencing was performed using the Illumina MiSeq platform. We obtained 32970 unigenes by assembling the pooled reads from all the libraries with Trinity software. Screening the nr database returned 18,362 sequences with functional annotation. Using the reference transcriptome we identified 1,246 genes that were differentially expressed after 48 h of NaCl stress. Genes related to several cellular functions such as membrane transport, osmoprotection, molecular chaperoning, redox metabolism or protein synthesis were differentially expressed in response to salt stress. The response of sea beet leaves to salt treatments was marked out by transcriptomic up-regulation of genes related to photosynthetic carbon fixation, ribosome biogenesis, cell wall-building and cell wall expansion. Furthermore, several novel and undescribed transcripts were responsive to salinity in leaves of sea beet.

  18. In planta differential targeting analysis of Thermotoga maritima Cel5A and CBM6-engineered Cel5A for autohydrolysis.

    PubMed

    Mahadevan, Shobana Arumugam; Wi, Seung Gon; Kim, Yeon Ok; Lee, Kwang Ho; Bae, Hyeun-Jong

    2011-08-01

    The heterologous expression of glycosyl hydrolases in bioenergy crops can improve the lignocellulosic conversion process for ethanol production. We attempted to obtain high-level expression of an intact Thermotoga maritima endoglucanase, Cel5A, and CBM6-engineered Cel5A in transgenic tobacco plants for the mass production and autohydrolysis of endoglucanase. Cel5A expression was targeted to different subcellular compartments, namely, the cytosol, apoplast, and chloroplast, using the native form of the pathogenesis-related protein 1a (PR1a) and Rubisco activase (RA) transit peptides. Cel5A transgenic tobacco plants with the chloroplast transit peptide showed the highest average endoglucanase activity and protein accumulation up to 4.5% total soluble protein. Cel5A-CBM6 was targeted to the chloroplast and accumulated up to 5.2% total soluble protein. In terms of the direct conversion of plant tissue into free sugar, the Cel5A-CBM6 transgenic plant was 33% more efficient than the Cel5A transgenic plant. The protein stability of Cel5A and Cel5A-CBM6 in lyophilized leaf material is an additional advantage in the bioconversion process.

  19. The Structural Basis of Alpha-Glucan Recognition by a Family 41 Carbohydrate-Binding Module from Therotoga Maritima

    SciTech Connect

    van Bueren,A.; Boraston, A.

    2006-01-01

    Starch recognition by carbohydrate-binding modules (CBMs) is important for the activity of starch-degrading enzymes. The N-terminal family 41 CBM, TmCBM41 (from pullulanase PulA secreted by Thermotoga maritima) was shown to have {alpha}-glucan binding activity with specificity for {alpha}-1, 4-glucans but was able to tolerate the {alpha}-1, 6-linkages found roughly every three or four glucose units in pullulan. Using X-ray crystallography, the structures were solved for TmCBM41 in an uncomplexed form and in complex with maltotetraose and 63-{alpha}-d-glucosyl-maltotriose (GM3). Ligand binding was facilitated by stacking interactions between the {alpha}-faces of the glucose residues and two tryptophan side-chains in the two main subsites of the carbohydrate-binding site. Overall, this mode of starch binding is quite well conserved by other starch-binding modules. The structure in complex with GM3 revealed a third binding subsite with the flexibility to accommodate an {alpha}-1, 4- or an {alpha}-1, 6-linked glucose.

  20. 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

  1. Structural Dissection of the Active Site of Thermotoga maritima β-Galactosidase Identifies Key Residues for Transglycosylating Activity.

    PubMed

    Talens-Perales, David; Polaina, Julio; Marín-Navarro, Julia

    2016-04-13

    Glycoside hydrolases, specifically β-galactosidases, can be used to synthesize galacto-oligosaccharides (GOS) due to the transglycosylating (secondary) activity of these enzymes. Site-directed mutagenesis of a thermoresistant β-galactosidase from Thermotoga maritima has been carried out to study the structural basis of transgalactosylation and to obtain enzymatic variants with better performance for GOS biosynthesis. Rational design of mutations was based on homologous sequence analysis and structural modeling. Analysis of mutant enzymes indicated that residue W959, or an alternative aromatic residue at this position, is critical for the synthesis of β-3'-galactosyl-lactose, the major GOS obtained with the wild-type enzyme. Mutants W959A and W959C, but not W959F, showed an 80% reduced synthesis of this GOS. Other substitutions, N574S, N574A, and F571L, increased the synthesis of β-3'-galactosyl-lactose about 40%. Double mutants F571L/N574S and F571L/N574A showed an increase of about 2-fold.

  2. Histone acetylation influences the transcriptional activation of POX in Beta vulgaris L. and Beta maritima L. under salt stress.

    PubMed

    Yolcu, Seher; Ozdemir, Filiz; Güler, Aybüke; Bor, Melike

    2016-03-01

    Acetylation of histone proteins is a type of chromatin modification which facilitates the activation of genes. Recent studies brought up the importance of this reversible and rapid process for the regulation of gene expression especially in plant defense against a variety of environmental stresses. Deciphering the exact mechanisms of chromatin modifications under abiotic stress conditions is important for improving crop plants' performance and yield. In a previous study we compared the salt stress responses of Beta vulgaris (sugar beet) and Beta maritima (wild beet). In accordance with those results we suggested that chromatin remodeling can be an active process in the regulation of genes related to salt stress tolerance of these plants. Therefore we performed ChIP assay in control and salt stressed (250 and 500 mM NaCl) plants and compared the enrichment of acetylation in the associated chromatin sites. We found that the transcriptional activation of one peroxidase (POX) encoding gene was associated with the elevated levels of acetylation in H3K9 and H3K27 sites. The acetylation patterns were remarkably different between two species in which the highest acetylation levels were found at H3K9 and H3K27 in wild beet and sugar beet respectively. PMID:26773543

  3. Evolutionary optimization of life-history traits in the sea beet Beta vulgaris subsp. maritima: Comparing model to data

    NASA Astrophysics Data System (ADS)

    Hautekèete, N.-C.; Van Dijk, H.; Piquot, Y.; Teriokhin, A.

    2009-01-01

    At evolutionary equilibrium, ecological factors will determine the optimal combination of life-history trait values of an organism. This optimum can be assessed by assuming that the species maximizes some criterion of fitness such as the Malthusian coefficient or lifetime reproductive success depending on the degree of density-dependence. We investigated the impact of the amount of resources and habitat stability on a plant's age at maturity and life span by using an evolutionary optimization model in combination with empirical data. We conducted this study on sea beet, Beta vulgaris subsp. maritima, because of its large variation in life span and age at first reproduction along a latitudinal gradient including considerable ecological variation. We also compared the consequence in our evolutionary model of maximizing either the Malthusian coefficient or the lifetime reproductive success. Both the data analysis and the results of evolutionary modeling pointed to habitat disturbance and resources like length of the growing season as factors negatively related to life span and age at maturity in sea beet. Resource availability had a negative theoretical influence with the Malthusian coefficient as the chosen optimality criterion, while there was no influence in the case of lifetime reproductive success. As suggested by previous theoretical work the final conclusion on what criterion is more adequate depends on the assumptions of how in reality density-dependence restrains population growth. In our case of sea beet data R0 seems to be less appropriate than λ.

  4. Transcriptomic profiling of the salt stress response in excised leaves of the halophyte Beta vulgaris ssp. maritima.

    PubMed

    Skorupa, Monika; Gołębiewski, Marcin; Domagalski, Krzysztof; Kurnik, Katarzyna; Abu Nahia, Karim; Złoch, Michał; Tretyn, Andrzej; Tyburski, Jarosław

    2016-02-01

    Beta vulgaris ssp. maritima is a halophytic relative of cultivated beets. In the present work a transcriptome response to acute salt stress imposed to excised leaves of sea beet was investigated. Salt treatments consisted of adding NaCl directly to the transpiration stream by immersing the petioles of excised leaves into the salt solutions. Sequencing libraries were generated from leaves subjected to either moderate or strong salt stress. Control libraries were constructed from untreated leaves. Sequencing was performed using the Illumina MiSeq platform. We obtained 32970 unigenes by assembling the pooled reads from all the libraries with Trinity software. Screening the nr database returned 18,362 sequences with functional annotation. Using the reference transcriptome we identified 1,246 genes that were differentially expressed after 48 h of NaCl stress. Genes related to several cellular functions such as membrane transport, osmoprotection, molecular chaperoning, redox metabolism or protein synthesis were differentially expressed in response to salt stress. The response of sea beet leaves to salt treatments was marked out by transcriptomic up-regulation of genes related to photosynthetic carbon fixation, ribosome biogenesis, cell wall-building and cell wall expansion. Furthermore, several novel and undescribed transcripts were responsive to salinity in leaves of sea beet. PMID:26795151

  5. Proteomic and physiological responses of the halophyte Cakile maritima to moderate salinity at the germinative and vegetative stages.

    PubMed

    Debez, Ahmed; Braun, Hans-Peter; Pich, Andreas; Taamalli, Wael; Koyro, Hans-Werner; Abdelly, Chedly; Huchzermeyer, Bernhard

    2012-10-22

    Responses of the halophyte Cakile maritima to moderate salinity were addressed at germination and vegetative stages by bringing together proteomics and eco-physiological approaches. 75 mM NaCl-salinity delayed significantly the germination process and decreased slightly the seed germination percentage compared to salt-free conditions. Monitoring the proteome profile between 0 h and 120 h after seed sowing revealed a delay in the degradation of seed storage proteins when germination took place under salinity, which may explain the slower germination rate observed. Of the sixty-seven proteins identified by mass spectrometry, several proteins involved in glycolysis, amino acid metabolism, photosynthesis, and protein folding showed significantly increased abundance during germination. This pattern was less pronounced under salinity. At the vegetative stage, 100mM NaCl-salinity stimulated significantly the plant growth, which was sustained by enhanced leaf expansion, water content, and photosynthetic activity. Comparative proteome analyses of leaf tissue revealed 44 proteins with different abundance changes, most of which being involved in energy metabolism. A specific set of proteins predominantly involved in photosynthesis and respiration showed significantly higher abundance in salt-treated plants. Altogether, combining proteomics with eco-physiological tools provides valuable information, which contributes to improve our understanding in the salt-response of this halophyte during its life cycle. PMID:22940175

  6. Histone acetylation influences the transcriptional activation of POX in Beta vulgaris L. and Beta maritima L. under salt stress.

    PubMed

    Yolcu, Seher; Ozdemir, Filiz; Güler, Aybüke; Bor, Melike

    2016-03-01

    Acetylation of histone proteins is a type of chromatin modification which facilitates the activation of genes. Recent studies brought up the importance of this reversible and rapid process for the regulation of gene expression especially in plant defense against a variety of environmental stresses. Deciphering the exact mechanisms of chromatin modifications under abiotic stress conditions is important for improving crop plants' performance and yield. In a previous study we compared the salt stress responses of Beta vulgaris (sugar beet) and Beta maritima (wild beet). In accordance with those results we suggested that chromatin remodeling can be an active process in the regulation of genes related to salt stress tolerance of these plants. Therefore we performed ChIP assay in control and salt stressed (250 and 500 mM NaCl) plants and compared the enrichment of acetylation in the associated chromatin sites. We found that the transcriptional activation of one peroxidase (POX) encoding gene was associated with the elevated levels of acetylation in H3K9 and H3K27 sites. The acetylation patterns were remarkably different between two species in which the highest acetylation levels were found at H3K9 and H3K27 in wild beet and sugar beet respectively.

  7. 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

  8. Transcriptome Analysis of the Response to NaCl in Suaeda maritima Provides an Insight into Salt Tolerance Mechanisms in Halophytes

    PubMed Central

    Tambat, Subodh; Vasudevan, Madavan

    2016-01-01

    Although salt tolerance is a feature representative of halophytes, most studies on this topic in plants have been conducted on glycophytes. Transcriptome profiles are also available for only a limited number of halophytes. Hence, the present study was conducted to understand the molecular basis of salt tolerance through the transcriptome profiling of the halophyte Suaeda maritima, which is an emerging plant model for research on salt tolerance. Illumina sequencing revealed 72,588 clustered transcripts, including 27,434 that were annotated using BLASTX. Salt application resulted in the 2-fold or greater upregulation of 647 genes and downregulation of 735 genes. Of these, 391 proteins were homologous to proteins in the COGs (cluster of orthologous groups) database, and the majorities were grouped into the poorly characterized category. Approximately 50% of the genes assigned to MapMan pathways showed homology to S. maritima. The majority of such genes represented transcription factors. Several genes also contributed to cell wall and carbohydrate metabolism, ion relation, redox responses and G protein, phosphoinositide and hormone signaling. Real-time PCR was used to validate the results of the deep sequencing for the most of the genes. This study demonstrates the expression of protein kinase C, the target of diacylglycerol in phosphoinositide signaling, for the first time in plants. This study further reveals that the biochemical and molecular responses occurring at several levels are associated with salt tolerance in S. maritima. At the structural level, adaptations to high salinity levels include the remodeling of cell walls and the modification of membrane lipids. At the cellular level, the accumulation of glycinebetaine and the sequestration and exclusion of Na+ appear to be important. Moreover, this study also shows that the processes related to salt tolerance might be highly complex, as reflected by the salt-induced enhancement of transcription factor

  9. Phenotypic Changes in Transgenic Tobacco Plants Overexpressing Vacuole-Targeted Thermotoga maritima BglB Related to Elevated Levels of Liberated Hormones

    PubMed Central

    Nguyen, Quynh Anh; Lee, Dae-Seok; Jung, Jakyun; Bae, Hyeun-Jong

    2015-01-01

    The hyperthermostable β-glucosidase BglB of Thermotoga maritima was modified by adding a short C-terminal tetrapeptide (AFVY, which transports phaseolin to the vacuole, to its C-terminal sequence). The modified β-glucosidase BglB was transformed into tobacco (Nicotiana tabacum L.) plants. We observed a range of significant phenotypic changes in the transgenic plants compared to the wild-type (WT) plants. The transgenic plants had faster stem growth, earlier flowering, enhanced root systems development, an increased biomass biosynthesis rate, and higher salt stress tolerance in young plants compared to WT. In addition, programed cell death was enhanced in mature plants. Furthermore, the C-terminal AFVY tetrapeptide efficiently sorted T. maritima BglB into the vacuole, which was maintained in an active form and could perform its glycoside hydrolysis function on hormone conjugates, leading to elevated hormone [abscisic acid (ABA), indole 3-acetic acid (IAA), and cytokinin] levels that likely contributed to the phenotypic changes in the transgenic plants. The elevation of cytokinin led to upregulation of the transcription factor WUSCHELL, a homeodomain factor that regulates the development, division, and reproduction of stem cells in the shoot apical meristems. Elevation of IAA led to enhanced root development, and the elevation of ABA contributed to enhanced tolerance to salt stress and programed cell death. These results suggest that overexpressing vacuole-targeted T. maritima BglB may have several advantages for molecular farming technology to improve multiple targets, including enhanced production of the β-glucosidase BglB, increased biomass, and shortened developmental stages, that could play pivotal roles in bioenergy and biofuel production. PMID:26618153

  10. Phenotypic Changes in Transgenic Tobacco Plants Overexpressing Vacuole-Targeted Thermotoga maritima BglB Related to Elevated Levels of Liberated Hormones.

    PubMed

    Nguyen, Quynh Anh; Lee, Dae-Seok; Jung, Jakyun; Bae, Hyeun-Jong

    2015-01-01

    The hyperthermostable β-glucosidase BglB of Thermotoga maritima was modified by adding a short C-terminal tetrapeptide (AFVY, which transports phaseolin to the vacuole, to its C-terminal sequence). The modified β-glucosidase BglB was transformed into tobacco (Nicotiana tabacum L.) plants. We observed a range of significant phenotypic changes in the transgenic plants compared to the wild-type (WT) plants. The transgenic plants had faster stem growth, earlier flowering, enhanced root systems development, an increased biomass biosynthesis rate, and higher salt stress tolerance in young plants compared to WT. In addition, programed cell death was enhanced in mature plants. Furthermore, the C-terminal AFVY tetrapeptide efficiently sorted T. maritima BglB into the vacuole, which was maintained in an active form and could perform its glycoside hydrolysis function on hormone conjugates, leading to elevated hormone [abscisic acid (ABA), indole 3-acetic acid (IAA), and cytokinin] levels that likely contributed to the phenotypic changes in the transgenic plants. The elevation of cytokinin led to upregulation of the transcription factor WUSCHELL, a homeodomain factor that regulates the development, division, and reproduction of stem cells in the shoot apical meristems. Elevation of IAA led to enhanced root development, and the elevation of ABA contributed to enhanced tolerance to salt stress and programed cell death. These results suggest that overexpressing vacuole-targeted T. maritima BglB may have several advantages for molecular farming technology to improve multiple targets, including enhanced production of the β-glucosidase BglB, increased biomass, and shortened developmental stages, that could play pivotal roles in bioenergy and biofuel production.

  11. Effect of carbon and nitrogen sources on growth dynamics and exopolysaccharide production for the hyperthermophilic archaeon Thermococcus litoralis and bacterium Thermotoga maritima.

    PubMed

    Rinker, K D; Kelly, R M

    2000-09-01

    Batch and continuous cultures were used to compare specific physiological features of the hyperthermophilic archaeon, Thermococcus litoralis (T(opt) of 85 degrees to 88 degrees C), to another fermentative hyperthermophile that reduces S degrees facultatively, that is, the bacterium Thermotoga maritima (T(opt) of 80 degrees to 85 degrees C). Under nutritionally optimal conditions, these two hyperthermophiles had similar growth yields on maltose and similar cell formula weights based on elemental analysis: CH(1.7)O(0. 7)N(0.2)S(0.006) for T. litoralis and CH(1.6)O(0.6)N(0.2)S(0.005) for T. maritima. However, they differed with respect to nitrogen source, fermentation product patterns, and propensity to form exopolysaccharides (EPS). T. litoralis could be cultured in the absence or presence of maltose on an amino acid-containing defined medium in which amino acids served as the sole nitrogen source. T. maritima, on the other hand, did not utilize amino acids as carbon, energy, or nitrogen sources, and could be grown in a similar defined medium only when supplemented with maltose and ammonium chloride. Not only was T. litoralis unable to utilize NH(4)Cl as a nitrogen source, its growth was inhibited at certain levels. At 1 g/L ( approximately 20 mM) NH(4)Cl, the maximum growth yield (Y(x/s(max))) for T. litoralis was reduced to 13 g cells dry weight (CDW)/mol glucose from 40 g CDW/mol glucose in media lacking NH(4)Cl. Alanine production increased with increasing NH(4)Cl concentrations and was most pronounced if growth on NH(4)Cl was carried out in an 80% H(2) atmosphere. In T. maritima cultures, which would not grow in an 80% H(2) atmosphere, alanine and EPS were produced at much lower levels, which did not change with NH(4)Cl concentration. EPS production rose sharply at high dilution rates for both organisms, such that maltose utilization plots were biphasic. Wall growth effects were also noted, because cultures failed to wash out at dilution rates significantly

  12. Crystal Structure of Butyrate Kinase 2 from Thermotoga maritima, a Member of the ASKHA Superfamily of Phosphotransferases

    SciTech Connect

    Diao, Jiasheng; Hasson, Miriam S.

    2009-04-01

    The enzymatic transfer of phosphoryl groups is central to the control of many cellular processes. One of the phosphoryl transfer mechanisms, that of acetate kinase, is not completely understood. Besides better understanding of the mechanism of acetate kinase, knowledge of the structure of butyrate kinase 2 (Buk2) will aid in the interpretation of active-site structure and provide information on the structural basis of substrate specificity. The gene buk2 from Thermotoga maritima encodes a member of the ASKHA (acetate and sugar kinases/heat shock cognate/actin) superfamily of phosphotransferases. The encoded protein Buk2 catalyzes the phosphorylation of butyrate and isobutyrate. We have determined the 2.5-{angstrom} crystal structure of Buk2 complexed with ({beta},{gamma}-methylene) adenosine 5'-triphosphate. Buk2 folds like an open-shelled clam, with each of the two domains representing one of the two shells. In the open active-site cleft between the N- and C-terminal domains, the active-site residues consist of two histidines, two arginines, and a cluster of hydrophobic residues. The ATP binding region of Buk2 in the C-terminal domain consists of abundant glycines for nucleotide binding, and the ATP binding motif is similar to those of other members of the ASKHA superfamily. The enzyme exists as an octamer, in which four disulfide bonds form between intermolecular cysteines. Sequence alignment and structure superposition identify the simplicity of the monomeric Buk2 structure, a probable substrate binding site, the key residues in catalyzing phosphoryl transfer, and the substrate specificity differences among Buk2, acetate, and propionate kinases. The possible enzyme mechanisms are discussed.

  13. Improved activity of a thermophilic cellulase, Cel5A, from Thermotoga maritima on ionic liquid pretreated switchgrass.

    PubMed

    Chen, Zhiwei; Pereira, Jose H; Liu, Hanbin; Tran, Huu M; Hsu, Nathan S Y; Dibble, Dean; Singh, Seema; Adams, Paul D; Sapra, Rajat; Hadi, Masood Z; Simmons, Blake A; Sale, Kenneth L

    2013-01-01

    Ionic liquid pretreatment of biomass has been shown to greatly reduce the recalcitrance of lignocellulosic biomass, resulting in improved sugar yields after enzymatic saccharification. However, even under these improved saccharification conditions the cost of enzymes still represents a significant proportion of the total cost of producing sugars and ultimately fuels from lignocellulosic biomass. Much of the high cost of enzymes is due to the low catalytic efficiency and stability of lignocellulolytic enzymes, especially cellulases, under conditions that include high temperatures and the presence of residual pretreatment chemicals, such as acids, organic solvents, bases, or ionic liquids. Improving the efficiency of the saccharification process on ionic liquid pretreated biomass will facilitate reduced enzyme loading and cost. Thermophilic cellulases have been shown to be stable and active in ionic liquids but their activity is typically at lower levels. Cel5A_Tma, a thermophilic endoglucanase from Thermotoga maritima, is highly active on cellulosic substrates and is stable in ionic liquid environments. Here, our motivation was to engineer mutants of Cel5A_Tma with higher activity on 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) pretreated biomass. We developed a robotic platform to screen a random mutagenesis library of Cel5A_Tma. Twelve mutants with 25-42% improvement in specific activity on carboxymethyl cellulose and up to 30% improvement on ionic-liquid pretreated switchgrass were successfully isolated and characterized from a library of twenty thousand variants. Interestingly, most of the mutations in the improved variants are located distally to the active site on the protein surface and are not directly involved with substrate binding. PMID:24244549

  14. Complexed Structures of Formylglycinamide Ribonucleotide Amidotransferase from Thermotoga maritima Describe a Novel ATP-binding Protein Superfamily†,‡

    PubMed Central

    Morar, Mariya; Anand, Ruchi; Hoskins, Aaron A.; Stubbe, JoAnne; Ealick, Steven E.

    2008-01-01

    Formylglycinamide ribonucleotide amidotransferase (FGAR-AT) catalyzes the ATP-dependent synthesis of formylglycinamidine ribonucleotide (FGAM) from formylglycinamide ribonucleotide (FGAR) and glutamine in the fourth step of the purine biosynthetic pathway. FGAR-AT is encoded by the purL gene. Two types of PurL have been detected. The first type, found in eukaryotes and Gram-negative bacteria, consists of a single 140 kDa polypeptide chain and is designated large PurL (lgPurL). The second type, small PurL (smPurL), is found in archaea and Gram-positive bacteria and consists of an 80 kDa polypeptide chain. Small PurL requires two additional gene products, PurQ and PurS, for activity. PurL is a member of a protein superfamily that contains a novel ATP-binding domain. Structures of several members of this superfamily are available in the apo form. We determined five different structures of FGAR-AT from Thermotoga maritima in the presence of substrates, a substrate analog, and a product. These complexes have allowed a detailed description of the novel ATP-binding motif. Availability of a ternary complex enabled mapping of the active site thus identifying potential residues involved in catalysis. The complexes show a conformational change in the active site compared to the unliganded structure. A surprising discovery, an ATP molecule in an auxiliary site of the protein and the conformational changes associated with its binding, provoke speculations about the regulatory role of the auxiliary site in PurLSQ complex formation as well as the evolutionary relationship of PurL's from different organisms. PMID:17154526

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

    PubMed Central

    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 acid residues with a calculated molecular mass of 16.30 and 16.58 kDa, respectively. The similarity between amino acid sequences of these proteins is very high: 90% identity and 95% similarity. Surprisingly, both TmaSSB and TneSSB possess a quite low sequence similarity to Escherichia coli SSB (36 and 35% identity, 55 and 56% similarity, respectively). They are functional as homotetramers containing one single-stranded DNA binding domain (OB-fold) in each monomer. Agarose mobility assays indicated that the ssDNA-binding site for both proteins is salt independent, and fluorescence spectroscopy resulted in a size of 68 ± 2 nucleotides. The half-lives of TmaSSB and TneSSB were 10 h and 12 h at 100°C, respectively. When analysed by differential scanning microcalorimetry (DSC) the melting temperature (Tm) was 109.3°C and 112.5°C for TmaSSB and TneSSB, respectively. Conclusion The results showed that TmaSSB and TneSSB are the most thermostable SSB proteins identified to date, offering an attractive alternative to TaqSSB and TthSSB in molecular biology applications, especially with using high temperature e. g. polymerase chain reaction (PCR). PMID:20950419

  16. Site-Directed Mutagenesis of a Hyperthermophilic Endoglucanase Cel12B from Thermotoga maritima Based on Rational Design

    PubMed Central

    Zhang, Jinfeng; Shi, Hao; Xu, Linyu; Zhu, Xiaoyan; Li, Xiangqian

    2015-01-01

    To meet the demand for the application of high activity and thermostable cellulases in the production of new-generation bioethanol from nongrain-cellulose sources, a hyperthermostable β-1,4-endoglucase Cel12B from Thermotoga maritima was selected for further modification by gene site-directed mutagenesis method in the present study, based on homology modeling and rational design. As a result, two recombinant enzymes showed significant improvement in enzyme activity by 77% and 87%, respectively, higher than the parental enzyme TmCel12B. Furthermore, the two mutants could retain 80% and 90.5% of their initial activity after incubation at 80°C for 8 h, while only 45% for 5 h to TmCel12B. The Km and Vmax of the two recombinant enzymes were 1.97±0.05 mM, 4.23±0.15 μmol·mg-1·min-1 of TmCel12B-E225H-K207G-D37V, and 2.97±0.12 mM, 3.15±0.21 μmol·mg-1·min-1 of TmCel12B-E225H-K207G, respectively, when using CMC-Na as the substrate. The roles of the mutation sites were also analyzed and evaluated in terms of electron density, hydrophobicity of the modeled protein structures. The recombinant enzymes may be used in the hydrolysis of cellulose at higher temperature in the future. It was concluded that the gene mutagenesis approach of a certain active residues may effectively improve the performance of cellulases for the industrial applications and contribute to the study the thermostable mechanism of thermophilic enzymes. PMID:26218520

  17. Isolation, characterization, sequencing and crystal structure of charybdin, a type 1 ribosome-inactivating protein from Charybdis maritima agg.

    PubMed

    Touloupakis, Eleftherios; Gessmann, Renate; Kavelaki, Kalliopi; Christofakis, Emmanuil; Petratos, Kyriacos; Ghanotakis, Demetrios F

    2006-06-01

    A novel, type 1 ribosome-inactivating protein designated charybdin was isolated from bulbs of Charybdis maritima agg. The protein, consisting of a single polypeptide chain with a molecular mass of 29 kDa, inhibited translation in rabbit reticulocytes with an IC50 of 27.2 nm. Plant genomic DNA extracted from the bulb was amplified by PCR between primers based on the N-terminal and C-terminal sequence of the protein from dissolved crystals. The complete mature protein sequence was derived by partial DNA sequencing and terminal protein sequencing, and was confirmed by high-resolution crystal structure analysis. The protein contains Val at position 79 instead of the conserved Tyr residue of the ribosome-inactivating proteins known to date. To our knowledge, this is the first observation of a natural substitution of a catalytic residue at the active site of a natural ribosome-inactivating protein. This substitution in the active site may be responsible for the relatively low in vitro translation inhibitory effect compared with other ribosome-inactivating proteins. Single crystals were grown in the cold room from PEG6000 solutions. Diffraction data collected to 1.6 A resolution were used to determine the protein structure by the molecular replacement method. The fold of the protein comprises two structural domains: an alpha + beta N-terminal domain (residues 4-190) and a mainly alpha-helical C-terminal domain (residues 191-257). The active site is located in the interface between the two domains and comprises residues Val79, Tyr117, Glu167 and Arg170.

  18. Improved Activity of a Thermophilic Cellulase, Cel5A, from Thermotoga maritima on Ionic Liquid Pretreated Switchgrass

    PubMed Central

    Chen, Zhiwei; Pereira, Jose H.; Liu, Hanbin; Tran, Huu M.; Hsu, Nathan S. Y.; Dibble, Dean; Singh, Seema; Adams, Paul D.; Sapra, Rajat; Hadi, Masood Z.; Simmons, Blake A.; Sale, Kenneth L.

    2013-01-01

    Ionic liquid pretreatment of biomass has been shown to greatly reduce the recalcitrance of lignocellulosic biomass, resulting in improved sugar yields after enzymatic saccharification. However, even under these improved saccharification conditions the cost of enzymes still represents a significant proportion of the total cost of producing sugars and ultimately fuels from lignocellulosic biomass. Much of the high cost of enzymes is due to the low catalytic efficiency and stability of lignocellulolytic enzymes, especially cellulases, under conditions that include high temperatures and the presence of residual pretreatment chemicals, such as acids, organic solvents, bases, or ionic liquids. Improving the efficiency of the saccharification process on ionic liquid pretreated biomass will facilitate reduced enzyme loading and cost. Thermophilic cellulases have been shown to be stable and active in ionic liquids but their activity is typically at lower levels. Cel5A_Tma, a thermophilic endoglucanase from Thermotoga maritima, is highly active on cellulosic substrates and is stable in ionic liquid environments. Here, our motivation was to engineer mutants of Cel5A_Tma with higher activity on 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) pretreated biomass. We developed a robotic platform to screen a random mutagenesis library of Cel5A_Tma. Twelve mutants with 25–42% improvement in specific activity on carboxymethyl cellulose and up to 30% improvement on ionic-liquid pretreated switchgrass were successfully isolated and characterized from a library of twenty thousand variants. Interestingly, most of the mutations in the improved variants are located distally to the active site on the protein surface and are not directly involved with substrate binding. PMID:24244549

  19. Proline 235 plays a key role in the regulation of the oligomeric states of Thermotoga maritima Arginine Binding Protein.

    PubMed

    Smaldone, Giovanni; Vigorita, Marilisa; Ruggiero, Alessia; Balasco, Nicole; Dattelbaum, Jonathan D; D'Auria, Sabato; Del Vecchio, Pompea; Graziano, Giuseppe; Vitagliano, Luigi

    2016-07-01

    The Arginine Binding Protein isolated from Thermotoga maritima (TmArgBP) is a protein endowed with several peculiar properties. We have previously shown that TmArgBP dimerization is a consequence of the swapping of the C-terminal helix. Here we explored the structural determinants of TmArgBP domain swapping and oligomerization. In particular, we report a mutational analysis of the residue Pro235, which is located in the hinge region of the swapping dimer. This residue was either replaced with a Gly-Lys dipeptide (TmArgBP(P235GK)) or a Gly residue (TmArgBP(P235G)). Different forms of these mutants were generated and extensively characterized using biophysical techniques. For both TmArgBP(P235GK) and TmArgBP(P235G) mutants, the occurrence of multiple oligomerization states (monomers, dimers and trimers) was detected. The formation of well-folded monomeric forms for these mutants indicates that the dimerization through C-terminal domain swapping observed in wild-type TmArgBP is driven by conformational restraints imposed by the presence of Pro235 in the hinge region. Molecular dynamics studies corroborate this observation by showing that Gly235 assumes conformational states forbidden for Pro residues in the TmArgBP(P235G) monomer. Unexpectedly, the trimeric forms present: (a) peculiar circular dichroism spectra, (b) a great susceptibility to heating, and (c) the ability to bind the Thioflavin T dye. The present findings clearly demonstrate that single-point mutations have an important impact on the TmArgBP oligomerization process. In a wider context, they also indicate that proteins endowed with an intrinsic propensity to swap have an easy access to states with altered structural and, possibly, functional properties.

  20. Crystal structure of butyrate kinase 2 from Thermotoga maritima, a member of the ASKHA superfamily of phosphotransferases.

    PubMed

    Diao, Jiasheng; Hasson, Miriam S

    2009-04-01

    The enzymatic transfer of phosphoryl groups is central to the control of many cellular processes. One of the phosphoryl transfer mechanisms, that of acetate kinase, is not completely understood. Besides better understanding of the mechanism of acetate kinase, knowledge of the structure of butyrate kinase 2 (Buk2) will aid in the interpretation of active-site structure and provide information on the structural basis of substrate specificity. The gene buk2 from Thermotoga maritima encodes a member of the ASKHA (acetate and sugar kinases/heat shock cognate/actin) superfamily of phosphotransferases. The encoded protein Buk2 catalyzes the phosphorylation of butyrate and isobutyrate. We have determined the 2.5-A crystal structure of Buk2 complexed with (beta,gamma-methylene) adenosine 5'-triphosphate. Buk2 folds like an open-shelled clam, with each of the two domains representing one of the two shells. In the open active-site cleft between the N- and C-terminal domains, the active-site residues consist of two histidines, two arginines, and a cluster of hydrophobic residues. The ATP binding region of Buk2 in the C-terminal domain consists of abundant glycines for nucleotide binding, and the ATP binding motif is similar to those of other members of the ASKHA superfamily. The enzyme exists as an octamer, in which four disulfide bonds form between intermolecular cysteines. Sequence alignment and structure superposition identify the simplicity of the monomeric Buk2 structure, a probable substrate binding site, the key residues in catalyzing phosphoryl transfer, and the substrate specificity differences among Buk2, acetate, and propionate kinases. The possible enzyme mechanisms are discussed.

  1. Proline 235 plays a key role in the regulation of the oligomeric states of Thermotoga maritima Arginine Binding Protein.

    PubMed

    Smaldone, Giovanni; Vigorita, Marilisa; Ruggiero, Alessia; Balasco, Nicole; Dattelbaum, Jonathan D; D'Auria, Sabato; Del Vecchio, Pompea; Graziano, Giuseppe; Vitagliano, Luigi

    2016-07-01

    The Arginine Binding Protein isolated from Thermotoga maritima (TmArgBP) is a protein endowed with several peculiar properties. We have previously shown that TmArgBP dimerization is a consequence of the swapping of the C-terminal helix. Here we explored the structural determinants of TmArgBP domain swapping and oligomerization. In particular, we report a mutational analysis of the residue Pro235, which is located in the hinge region of the swapping dimer. This residue was either replaced with a Gly-Lys dipeptide (TmArgBP(P235GK)) or a Gly residue (TmArgBP(P235G)). Different forms of these mutants were generated and extensively characterized using biophysical techniques. For both TmArgBP(P235GK) and TmArgBP(P235G) mutants, the occurrence of multiple oligomerization states (monomers, dimers and trimers) was detected. The formation of well-folded monomeric forms for these mutants indicates that the dimerization through C-terminal domain swapping observed in wild-type TmArgBP is driven by conformational restraints imposed by the presence of Pro235 in the hinge region. Molecular dynamics studies corroborate this observation by showing that Gly235 assumes conformational states forbidden for Pro residues in the TmArgBP(P235G) monomer. Unexpectedly, the trimeric forms present: (a) peculiar circular dichroism spectra, (b) a great susceptibility to heating, and (c) the ability to bind the Thioflavin T dye. The present findings clearly demonstrate that single-point mutations have an important impact on the TmArgBP oligomerization process. In a wider context, they also indicate that proteins endowed with an intrinsic propensity to swap have an easy access to states with altered structural and, possibly, functional properties. PMID:27087545

  2. Directed evolution of the alpha-L-fucosidase from Thermotoga maritima into an alpha-L-transfucosidase.

    PubMed

    Osanjo, George; Dion, Michel; Drone, Jullien; Solleux, Claude; Tran, Vinh; Rabiller, Claude; Tellier, Charles

    2007-01-30

    The alpha-L-fucosidase from Thermotoga maritima (Tm alpha fuc) was converted into alpha-L-transfucosidase variants by directed evolution. The wild-type enzyme catalyzes oligosaccharide synthesis by transfer of a fucosyl residue from a pNP-fucoside donor to pNP-fucoside (self-condensation) with alpha-(1-->3) regioselectivity or pNP-galactoside (transglycosylation) with alpha-(1-->2) regioselectivity at low yields (7%). The wild-type enzyme was submitted to one cycle of mutagenesis, followed by rational recombination of the selected mutations, which allowed identification of variants with improved transferase activity. The transferase and hydrolytic kinetics of all the mutants were assessed by NMR methods and capillary electrophoresis. It was shown that the best mutant exhibited a dramatic 32-fold increase in the transferase/hydrolytic kinetic ratio, while keeping 60% of the overall wild-type enzyme activity. Accordingly, the maximum yield of a specific transglycosylation product [pNP-Gal-alpha-(1-->2)-Fuc] reached more than 60% compared to 7% with WT enzyme at equimolar and low concentrations of donor and acceptor (10 mM). Such an improvement was obtained with only three mutations (T264A, Y267F, L322P), which were all located in the second amino acid shell of the fucosidase active site. Molecular modeling suggested that some of these mutations (T264A, Y267F) cause a reorientation of the amino acids that are in direct contact with the substrates, resulting in a better docking energy. Such mutants with high transglycosidase activity may constitute novel enzymatic tools for the synthesis of fucooligosaccharides.

  3. Screening beneficial rhizobacteria from Spartina maritima for phytoremediation of metal polluted salt marshes: comparison of gram-positive and gram-negative strains.

    PubMed

    Paredes-Páliz, Karina I; Caviedes, Miguel A; Doukkali, Bouchra; Mateos-Naranjo, Enrique; Rodríguez-Llorente, Ignacio D; Pajuelo, Eloísa

    2016-10-01

    The aim of our work was the isolation and characterization of bacteria from the rhizosphere of Spartina maritima in the metal contaminated Odiel estuary (Huelva, SW Spain). From 25 strains, 84 % were identified as gram-positive, particularly Staphylococcus and Bacillus. Gram-negative bacteria were represented by Pantoea and Salmonella. Salt and heavy metal tolerance, metal bioabsorption, plant growth promoting (PGP) properties, and biofilm formation were investigated in the bacterial collection. Despite the higher abundance of gram-positive bacteria, gram-negative isolates displayed higher tolerance toward metal(loid)s (As, Cu, Zn, and Pb) and greater metal biosorption, as deduced from ICP-OES and SEM-EDX analyses. Besides, they exhibited better PGP properties, which were retained in the presence of metals and the ability to form biofilms. Gram-negative strains Pantoea agglomerans RSO6 and RSO7, together with gram-positive Bacillus aryabhattai RSO25, were selected for a bacterial consortium aimed to inoculate S. maritima plants in metal polluted estuaries for phytoremediation purposes. PMID:27417328

  4. Screening beneficial rhizobacteria from Spartina maritima for phytoremediation of metal polluted salt marshes: comparison of gram-positive and gram-negative strains.

    PubMed

    Paredes-Páliz, Karina I; Caviedes, Miguel A; Doukkali, Bouchra; Mateos-Naranjo, Enrique; Rodríguez-Llorente, Ignacio D; Pajuelo, Eloísa

    2016-10-01

    The aim of our work was the isolation and characterization of bacteria from the rhizosphere of Spartina maritima in the metal contaminated Odiel estuary (Huelva, SW Spain). From 25 strains, 84 % were identified as gram-positive, particularly Staphylococcus and Bacillus. Gram-negative bacteria were represented by Pantoea and Salmonella. Salt and heavy metal tolerance, metal bioabsorption, plant growth promoting (PGP) properties, and biofilm formation were investigated in the bacterial collection. Despite the higher abundance of gram-positive bacteria, gram-negative isolates displayed higher tolerance toward metal(loid)s (As, Cu, Zn, and Pb) and greater metal biosorption, as deduced from ICP-OES and SEM-EDX analyses. Besides, they exhibited better PGP properties, which were retained in the presence of metals and the ability to form biofilms. Gram-negative strains Pantoea agglomerans RSO6 and RSO7, together with gram-positive Bacillus aryabhattai RSO25, were selected for a bacterial consortium aimed to inoculate S. maritima plants in metal polluted estuaries for phytoremediation purposes.

  5. Regulation of Endo-Acting Glycosyl Hydrolases in the Hyperthermophilic Bacterium Thermotoga maritima Grown on Glucan- and Mannan-Based Polysaccharides

    PubMed Central

    Chhabra, Swapnil R.; Shockley, Keith R.; Ward, Donald E.; Kelly, Robert M.

    2002-01-01

    The genome sequence of the hyperthermophilic bacterium Thermotoga maritima encodes a number of glycosyl hydrolases. Many of these enzymes have been shown in vitro to degrade specific glycosides that presumably serve as carbon and energy sources for the organism. However, because of the broad substrate specificity of many glycosyl hydrolases, it is difficult to determine the physiological substrate preferences for specific enzymes from biochemical information. In this study, T. maritima was grown on a range of polysaccharides, including barley β-glucan, carboxymethyl cellulose, carob galactomannan, konjac glucomannan, and potato starch. In all cases, significant growth was observed, and cell densities reached 109 cells/ml. Northern blot analyses revealed different substrate-dependent expression patterns for genes encoding the various endo-acting β-glycosidases; these patterns ranged from strong expression to no expression under the conditions tested. For example, cel74 (TM0305), a gene encoding a putative β-specific endoglucananse, was strongly expressed on all substrates tested, including starch, while no evidence of expression was observed on any substrate for lam16 (TM0024), xyl10A (TM0061), xyl10B (TM0070), and cel12A (TM1524), which are genes that encode a laminarinase, two xylanases, and an endoglucanase, respectively. The cel12B (TM1525) gene, which encodes an endoglucanase, was expressed only on carboxymethyl cellulose. An extracellular mannanase encoded by man5 (TM1227) was expressed on carob galactomannan and konjac glucomannan and to a lesser extent on carboxymethyl cellulose. An unexpected result was the finding that the cel5A (TM1751) and cel5B (TM1752) genes, which encode putative intracellular, β-specific endoglucanases, were induced only when T. maritima was grown on konjac glucomannan. To investigate the biochemical basis of this finding, the recombinant forms of Man5 (Mr, 76,900) and Cel5A (Mr, 37,400) were expressed in Escherichia coli and

  6. Genetic Diversity and Physiological Performance of Portuguese Wild Beet (Beta vulgaris spp. maritima) from Three Contrasting Habitats.

    PubMed

    Ribeiro, Isa C; Pinheiro, Carla; Ribeiro, Carla M; Veloso, Maria M; Simoes-Costa, Maria C; Evaristo, Isabel; Paulo, Octávio S; Ricardo, Cândido P

    2016-01-01

    The establishment of stress resilient sugar beets (Beta vulgaris spp. vulgaris) is an important breeding goal since this cash crop is susceptible to drought and salinity. The genetic diversity in cultivated sugar beets is low and the beet wild relatives are useful genetic resources for tolerance traits. Three wild beet populations (Beta vulgaris spp. maritima) from contrasting environments, Vaiamonte (VMT, dry inland hill), Comporta (CMP, marsh) and Oeiras (OEI, coastland), and one commercial sugar beet (Isella variety, SB), are compared. At the genetic level, the use of six microsatellite allowed to detect a total of seventy six alleles. It was observed that CMP population has the highest value concerning the effective number of alleles and of expected heterozygosity. By contrast, sugar beet has the lowest values for all the parameters considered. Loci analysis with STRUCTURE allows defining three genetic clusters, the sea beet (OEI and CMP), the inland ruderal beet (VMT) and the sugar beet (SB). A screening test for progressive drought and salinity effects demonstrated that: all populations were able to recover from severe stress; drought impact was higher than that from salinity; the impact on biomass (total, shoot, root) was population specific. The distinct strategies were also visible at physiological level. We evaluated the physiological responses of the populations under drought and salt stress, namely at initial stress stages, late stress stages, and early stress recovery. Multivariate analysis showed that the physiological performance can be used to discriminate between genotypes, with a strong contribution of leaf temperature and leaf osmotic adjustment. However, the separation achieved and the groups formed are dependent on the stress type, stress intensity and duration. Each of the wild beet populations evaluated is very rich in genetic terms (allelic richness) and exhibited physiological plasticity, i.e., the capacity to physiologically adjust to

  7. Genetic Diversity and Physiological Performance of Portuguese Wild Beet (Beta vulgaris spp. maritima) from Three Contrasting Habitats.

    PubMed

    Ribeiro, Isa C; Pinheiro, Carla; Ribeiro, Carla M; Veloso, Maria M; Simoes-Costa, Maria C; Evaristo, Isabel; Paulo, Octávio S; Ricardo, Cândido P

    2016-01-01

    The establishment of stress resilient sugar beets (Beta vulgaris spp. vulgaris) is an important breeding goal since this cash crop is susceptible to drought and salinity. The genetic diversity in cultivated sugar beets is low and the beet wild relatives are useful genetic resources for tolerance traits. Three wild beet populations (Beta vulgaris spp. maritima) from contrasting environments, Vaiamonte (VMT, dry inland hill), Comporta (CMP, marsh) and Oeiras (OEI, coastland), and one commercial sugar beet (Isella variety, SB), are compared. At the genetic level, the use of six microsatellite allowed to detect a total of seventy six alleles. It was observed that CMP population has the highest value concerning the effective number of alleles and of expected heterozygosity. By contrast, sugar beet has the lowest values for all the parameters considered. Loci analysis with STRUCTURE allows defining three genetic clusters, the sea beet (OEI and CMP), the inland ruderal beet (VMT) and the sugar beet (SB). A screening test for progressive drought and salinity effects demonstrated that: all populations were able to recover from severe stress; drought impact was higher than that from salinity; the impact on biomass (total, shoot, root) was population specific. The distinct strategies were also visible at physiological level. We evaluated the physiological responses of the populations under drought and salt stress, namely at initial stress stages, late stress stages, and early stress recovery. Multivariate analysis showed that the physiological performance can be used to discriminate between genotypes, with a strong contribution of leaf temperature and leaf osmotic adjustment. However, the separation achieved and the groups formed are dependent on the stress type, stress intensity and duration. Each of the wild beet populations evaluated is very rich in genetic terms (allelic richness) and exhibited physiological plasticity, i.e., the capacity to physiologically adjust to

  8. Genetic Diversity and Physiological Performance of Portuguese Wild Beet (Beta vulgaris spp. maritima) from Three Contrasting Habitats

    PubMed Central

    Ribeiro, Isa C.; Pinheiro, Carla; Ribeiro, Carla M.; Veloso, Maria M.; Simoes-Costa, Maria C.; Evaristo, Isabel; Paulo, Octávio S.; Ricardo, Cândido P.

    2016-01-01

    The establishment of stress resilient sugar beets (Beta vulgaris spp. vulgaris) is an important breeding goal since this cash crop is susceptible to drought and salinity. The genetic diversity in cultivated sugar beets is low and the beet wild relatives are useful genetic resources for tolerance traits. Three wild beet populations (Beta vulgaris spp. maritima) from contrasting environments, Vaiamonte (VMT, dry inland hill), Comporta (CMP, marsh) and Oeiras (OEI, coastland), and one commercial sugar beet (Isella variety, SB), are compared. At the genetic level, the use of six microsatellite allowed to detect a total of seventy six alleles. It was observed that CMP population has the highest value concerning the effective number of alleles and of expected heterozygosity. By contrast, sugar beet has the lowest values for all the parameters considered. Loci analysis with STRUCTURE allows defining three genetic clusters, the sea beet (OEI and CMP), the inland ruderal beet (VMT) and the sugar beet (SB). A screening test for progressive drought and salinity effects demonstrated that: all populations were able to recover from severe stress; drought impact was higher than that from salinity; the impact on biomass (total, shoot, root) was population specific. The distinct strategies were also visible at physiological level. We evaluated the physiological responses of the populations under drought and salt stress, namely at initial stress stages, late stress stages, and early stress recovery. Multivariate analysis showed that the physiological performance can be used to discriminate between genotypes, with a strong contribution of leaf temperature and leaf osmotic adjustment. However, the separation achieved and the groups formed are dependent on the stress type, stress intensity and duration. Each of the wild beet populations evaluated is very rich in genetic terms (allelic richness) and exhibited physiological plasticity, i.e., the capacity to physiologically adjust to

  9. Genetic Diversity and Physiological Performance of Portuguese Wild Beet (Beta vulgaris spp. maritima) from Three Contrasting Habitats

    PubMed Central

    Ribeiro, Isa C.; Pinheiro, Carla; Ribeiro, Carla M.; Veloso, Maria M.; Simoes-Costa, Maria C.; Evaristo, Isabel; Paulo, Octávio S.; Ricardo, Cândido P.

    2016-01-01

    The establishment of stress resilient sugar beets (Beta vulgaris spp. vulgaris) is an important breeding goal since this cash crop is susceptible to drought and salinity. The genetic diversity in cultivated sugar beets is low and the beet wild relatives are useful genetic resources for tolerance traits. Three wild beet populations (Beta vulgaris spp. maritima) from contrasting environments, Vaiamonte (VMT, dry inland hill), Comporta (CMP, marsh) and Oeiras (OEI, coastland), and one commercial sugar beet (Isella variety, SB), are compared. At the genetic level, the use of six microsatellite allowed to detect a total of seventy six alleles. It was observed that CMP population has the highest value concerning the effective number of alleles and of expected heterozygosity. By contrast, sugar beet has the lowest values for all the parameters considered. Loci analysis with STRUCTURE allows defining three genetic clusters, the sea beet (OEI and CMP), the inland ruderal beet (VMT) and the sugar beet (SB). A screening test for progressive drought and salinity effects demonstrated that: all populations were able to recover from severe stress; drought impact was higher than that from salinity; the impact on biomass (total, shoot, root) was population specific. The distinct strategies were also visible at physiological level. We evaluated the physiological responses of the populations under drought and salt stress, namely at initial stress stages, late stress stages, and early stress recovery. Multivariate analysis showed that the physiological performance can be used to discriminate between genotypes, with a strong contribution of leaf temperature and leaf osmotic adjustment. However, the separation achieved and the groups formed are dependent on the stress type, stress intensity and duration. Each of the wild beet populations evaluated is very rich in genetic terms (allelic richness) and exhibited physiological plasticity, i.e., the capacity to physiologically adjust to

  10. Enhanced catalytic efficiency in quercetin-4'-glucoside hydrolysis of Thermotoga maritima β-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 β-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 β-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'.

  11. Backbone ¹H, ¹³C and ¹⁵N resonance assignments of the α-helical membrane protein TM0026 from Thermotoga maritima.

    PubMed

    Kroncke, Brett M; Columbus, Linda

    2013-10-01

    Critical to the use of solution NMR to describe the structure and flexibility of membrane proteins is the thorough understanding of the degree of perturbation induced by the detergent or other membrane mimetic. To develop a deeper understanding of the interaction between membrane proteins and micelles or bicelles, we will investigate the differences in structure and flexibility of a model membrane protein TM0026 from Thermotoga maritima using solution NMR. A comparison of the structural differences between TM0026 solubilized in different detergent combinations will provide important insight into the degree of modulation of membrane proteins by detergent physical properties. Here we report the nearly complete backbone and Cβ resonance assignments of the two transmembrane helical model protein TM0026. These assignments are the first step to using TM0026 to elucidate the interaction between membrane proteins and membrane mimetics.

  12. Pollen limitation of female reproductive success at fine spatial scale in a gynodioecious and wind-pollinated species, Beta vulgaris ssp. maritima.

    PubMed

    De Cauwer, I; Arnaud, J-F; Schmitt, E; Dufay, M

    2010-12-01

    In sexually polymorphic plants, the spatial distribution of sexes is usually not random. Local variation in phenotype frequencies is expected to affect individual fitness of the different phenotypes. For gynodioecious species, with co-occurrence of hermaphrodites and females, if sexual phenotypes are structured in space and pollen flow is spatially restricted, local pollen availability should vary among patches. Female fitness may thus be low when hermaphrodites are locally rare. To test this hypothesis, we analysed how the reproductive output of females varied among patches within two natural study sites of the gynodioecious wind-pollinated Beta vulgaris ssp. maritima. Plants growing in female-biased areas and experiencing pollen limitation were found to have low fruit and seed sets but did not reallocate resources towards better offspring. Our results show that fine-scale processes influence individual fitness and the evolution of sex ratio in sexually polymorphic plants.

  13. Potential for evolutionary change in the seasonal timing of germination in sea beet (Beta vulgaris ssp. maritima) mediated by seed dormancy.

    PubMed

    Wagmann, Kristen; Hautekèete, Nina-Coralie; Piquot, Yves; Van Dijk, Henk

    2010-07-01

    In sea beet (Beta vulgaris ssp. maritima), germination occurs in autumn or spring and is mediated by dormancy which can be released by cold or dry periods. Environmental change such as current climate change may require evolutionary response in seasonal timing. Here, we explore the potential for such evolutionary change. Seed dormancy was studied in a composite population based on seeds from all over the species range in France together with several generations of reciprocal crosses. We found high, repeatable variability for dormancy rate among individuals under greenhouse conditions and confirmed its relevance for germination phenology in the field. Our data fitted best with an exclusively maternal determination of the dormancy phenotype. Narrow-sense heritability, h(2) approximately 0.5 in the composite population and approximately 0.4 in the original local populations, was such that rapid evolutionary change in the relative proportions of autumn and spring germination may be possible.

  14. Fungal decontamination and enhancement of shelf life of edible split beans of wild legume Canavalia maritima by the electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Supriya, P.; Sridhar, K. R.; Ganesh, S.

    2014-03-01

    Ripened split beans of the coastal sand dune wild legume Canavalia maritima serve as one of the traditional nutritional sources of the coastal dwellers in Southwest coast of India. Nine fungi were isolated from the unirradiated dry beans by plating on the potato dextrose agar medium. Toxigenic fungus Aspergillus niger showed the highest incidence (33-50%) followed by Aspergillus flavus (14-20%) and Penicillium chrysogenum (7-13%). Unirradiated dry beans and irradiated dry beans with electron beam doses 2.5, 5, 10 and 15 kGy were monitored for occurrence of fungal species and their incidence during 0, 3 and 6 months storage period under laboratory conditions. Irradiation resulted in dose-dependent decrease in fungal species (5-7, 4-6, 3-6 and 0 on irradiation at 0, 2.5, 5 and 10 or 15 kGy, respectively) as well as incidence (80-99, 19-46, 13-21 and 0%, respectively). Although aflatoxins (B1 and B2) were found below detectable level (<2 ng/g) in 0, 3 and 6 months stored unirradiated and irradiated beans (2.5 and 5 kGy), they were not present in beans irradiated with 10 and 15 kGy. In spite of occurrence of toxigenic fungus Aspergillus ochraceus in unirradiated and irradiated beans (2.5 and 5 kGy) stored for 3 and 6 months, the beans were devoid of ochratoxin-A. Electron beam irradiation dose 10 kGy could be recommended for fungal decontamination and improvement of shelf life of C. maritima ripened dry split beans.

  15. Transcriptome de novo assembly from next-generation sequencing and comparative analyses in the hexaploid salt marsh species Spartina maritima and Spartina alterniflora (Poaceae)

    PubMed Central

    Ferreira de Carvalho, J; Poulain, J; Da Silva, C; Wincker, P; Michon-Coudouel, S; Dheilly, A; Naquin, D; Boutte, J; Salmon, A; Ainouche, M

    2013-01-01

    Spartina species have a critical ecological role in salt marshes and represent an excellent system to investigate recurrent polyploid speciation. Using the 454 GS-FLX pyrosequencer, we assembled and annotated the first reference transcriptome (from roots and leaves) for two related hexaploid Spartina species that hybridize in Western Europe, the East American invasive Spartina alterniflora and the Euro-African S. maritima. The de novo read assembly generated 38 478 consensus sequences and 99% found an annotation using Poaceae databases, representing a total of 16 753 non-redundant genes. Spartina expressed sequence tags were mapped onto the Sorghum bicolor genome, where they were distributed among the subtelomeric arms of the 10 S. bicolor chromosomes, with high gene density correlation. Normalization of the complementary DNA library improved the number of annotated genes. Ecologically relevant genes were identified among GO biological function categories in salt and heavy metal stress response, C4 photosynthesis and in lignin and cellulose metabolism. Expression of some of these genes had been found to be altered by hybridization and genome duplication in a previous microarray-based study in Spartina. As these species are hexaploid, up to three duplicated homoeologs may be expected per locus. When analyzing sequence polymorphism at four different loci in S. maritima and S. alterniflora, we found up to four haplotypes per locus, suggesting the presence of two expressed homoeologous sequences with one or two allelic variants each. This reference transcriptome will allow analysis of specific Spartina genes of ecological or evolutionary interest, estimation of homoeologous gene expression variation using RNA-seq and further gene expression evolution analyses in natural populations. PMID:23149455

  16. Phylogenetic depth of S10 and spc operons: cloning and sequencing of a ribosomal protein gene cluster from the extremely thermophilic bacterium Thermotoga maritima.

    PubMed Central

    Sanangelantoni, A M; Bocchetta, M; Cammarano, P; Tiboni, O

    1994-01-01

    A segment of Thermotoga maritima DNA spanning 6,613 bp downstream from the gene tuf for elongation factor Tu was sequenced by use of a chromosome walking strategy. The sequenced region comprised a string of 14 tightly linked open reading frames (ORFs) starting 50 bp downstream from tuf. The first 11 ORFs were identified as homologs of ribosomal protein genes rps10, rpl3, rpl4, rpl23, rpl2, rps19, rpl22, rps3, rpl16, rpl29, and rps17 (which in Escherichia coli constitute the S10 operon, in that order); the last three ORFs were homologous to genes rpl14, rpl24, and rpl5 (which in E. coli constitute the three promoter-proximal genes of the spectinomycin operon). The 14-gene string was preceded by putative -35 and -10 promoter sequences situated 5' to gene rps10, within the 50-bp spacing between genes tuf and rps10; the same region exhibited a potential transcription termination signal for the upstream gene cluster (having tuf as the last gene) but displayed also the potential for formation of a hairpin loop hindering the terminator; this suggests that transcription of rps10 and downstream genes may start farther upstream. The similar organization of the sequenced rp genes in the deepest-branching bacterial phyla (T. maritima) and among Archaea has been interpreted as indicating that the S10-spc gene arrangement existed in the (last) common ancestor. The phylogenetic depth of the Thermotoga lineage was probed by use of r proteins as marker molecules: in all except one case (S3), Proteobacteria or the gram-positive bacteria, and not the genus Thermotoga, were the deepest-branching lineage; in only two cases, however, was the inferred branching order substantiated by bootstrap analysis. PMID:8002596

  17. 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.

    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.

  18. Hyperthermostable Thermotoga maritima xylanase XYN10B shows high activity at high temperatures in the presence of biomass-dissolving hydrophilic ionic liquids.

    PubMed

    Yu, Tianyi; Anbarasan, Sasikala; Wang, Yawei; Telli, Kübra; Aslan, Aşkın Sevinç; Su, Zhengding; Zhou, Yin; Zhang, Li; Iivonen, Piia; Havukainen, Sami; Mentunen, Tero; Hummel, Michael; Sixta, Herbert; Binay, Baris; Turunen, Ossi; Xiong, Hairong

    2016-07-01

    The gene of Thermotoga maritima GH10 xylanase (TmXYN10B) was synthesised to study the extreme limits of this hyperthermostable enzyme at high temperatures in the presence of biomass-dissolving hydrophilic ionic liquids (ILs). TmXYN10B expressed from Pichia pastoris showed maximal activity at 100 °C and retained 92 % of maximal activity at 105 °C in a 30-min assay. Although the temperature optimum of activity was lowered by 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc), TmXYN10B retained partial activity in 15-35 % hydrophilic ILs, even at 75-90 °C. TmXYN10B retained over 80 % of its activity at 90 °C in 15 % [EMIM]OAc and 15-25 % 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM]DMP) during 22-h reactions. [EMIM]OAc may rigidify the enzyme and lower V max. However, only minor changes in kinetic parameter K m showed that competitive inhibition by [EMIM]OAc of TmXYN10B is minimal. In conclusion, when extended enzymatic reactions under extreme conditions are required, TmXYN10B shows extraordinary potential. PMID:27240671

  19. Spatial analysis of nuclear and cytoplasmic DNA diversity in wild sea beet (Beta vulgaris ssp. maritima) populations: do marine currents shape the genetic structure?

    PubMed

    Fievet, Virgil; Touzet, Pascal; Arnaud, Jean-François; Cuguen, Joël

    2007-05-01

    Patterns of seed dispersal in the wild sea beet (Beta vulgaris ssp. maritima) are predicted to be influenced by marine currents because populations are widely distributed along the European Atlantic coast. We investigated the potential influence of marine currents on the pattern of spatial genetic structuring in natural populations of sea beet. Populations were located along the French coasts of the Anglo-Norman gulf that features peculiar marine currents in the Channel. Thirty-three populations were sampled, among which 23 were continental and 10 were insular populations located in Jersey, Guernsey and Chausey, for a total of 1224 plants genotyped. To validate the coastal topography influence and the possibility of marine current orientated gene flow on the genetic features of sea beet populations, we assessed patterns of genetic structuring of cytoplasmic and nuclear diversity by: (i) searching for an isolation-by-distance (IBD) pattern using spatial autocorrelation tools; (ii) using the Monmonier algorithm to identify genetic boundaries in the area studied; and (iii) performing assignment tests that are based on multilocus genotype information to ascertain population membership of individuals. Our results showed a highly contrasted cytoplasmic and nuclear genetic differentiation and highlighted the peculiar situation of island populations. Beyond a classical isolation-by-distance due to short-range dispersal, genetic barriers fitting the orientation of marine currents were clearly identified. This suggests the occurrence of long-distance seed dispersal events and an asymmetrical gene flow separating the eastern and western part of the Anglo-Norman gulf.

  20. Crystal structure of 1-deoxy-d-xylulose 5-phosphate reductoisomerase from the hyperthermophile Thermotoga maritima for insights into the coordination of conformational changes and an inhibitor binding.

    PubMed

    Takenoya, Mihoko; Ohtaki, Akashi; Noguchi, Keiichi; Endo, Kiwamu; Sasaki, Yasuyuki; Ohsawa, Kanju; Yajima, Shunsuke; Yohda, Masafumi

    2010-06-01

    Isopentenyl diphosphate is a precursor of various isoprenoids and is produced by the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway in plastids of plants, protozoa and many eubacteria. A key enzyme in the MEP pathway, 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR), has been shown to be the target of fosmidomycin, which works as an antimalarial, antibacterial and herbicidal compound. In this paper, we report studies of kinetics and the crystal structures of the thermostable DXR from the hyperthermophile Thermotoga maritima. Unlike the mesophilic DXRs, Thermotoga DXR (tDXR) showed activity only with Mg(2+) at its growth temperature. We solved the crystal structures of tDXR with and without fosmidomycin. The structure without fosmidomycin but unexpectedly bound with 2-methyl-2,4-pentanediol (MPD), revealing a new extra space available for potential drug design. This structure adopted the closed form by rigid domain rotation but without the flexible loop over the active site, which was considered as a novel conformation. Further, the conserved Asp residue responsible for cation binding seemed to play an important role in adjusting the position of fosmidomycin. Taken together, our kinetic and the crystal structures illustrate the binding mode of fosmidomycin that leads to its slow, tight binding according to the conformational changes of DXR.

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

    PubMed

    Nadwodnik, Jan; Lohaus, Gertrud

    2008-04-01

    Sugar and sugar alcohol concentrations were analyzed in subcellular compartments of mesophyll cells, in the apoplast, and 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, whereas celery translocated mannitol as well. Sucrose was always present in vacuole and cytosol of mesophyll cells, whereas sorbitol and mannitol were found in vacuole, stroma, and cytosol in all cases except for sea plantain. The concentration of sorbitol, mannitol and sucrose in phloem sap was 2- to 40-fold higher than that in the cytosol of mesophyll cells. Apoplastic carbohydrate concentrations in all species tested were in the low millimolar range versus high millimolar concentrations in symplastic compartments. Therefore, the concentration ratios between the apoplast and the phloem were very strong, ranging between 20- to 100-fold for sorbitol and mannitol, and between 200- and 2000-fold for sucrose. The woody species, peach, showed the smallest concentration ratios between the cytosol of mesophyll cells and the phloem as well as between the apoplast and the phloem, suggesting a mixture of apoplastic and symplastic phloem loading, in contrast to the herbal plant species (common plantain, sea plantain, celery) which likely exhibit an active loading mode for sorbitol and mannitol as well as sucrose from the apoplast into the phloem.

  2. Quadrupole time-of-flight mass spectrometry analysis of glycerophospholipid molecular species in the two halophyte seed oils: Eryngium maritimum and Cakile maritima.

    PubMed

    Zitouni, Manel; Wewer, Vera; Dörmann, Peter; Abdelly, Chedly; Ben Youssef, Nabil

    2016-12-15

    Future applications of lipids in clinical cohort studies demand detailed glycerophospholipid molecule information and the application of high-throughput lipidomics platforms. In the present work, a novel sensitive technique with high mass resolution and accuracy was applied to accomplish phospholipid analysis. Nanospray ionization quadrupole time-of-flight mass spectrometry was used to separate and quantify the glycerophospholipid classes as well as molecular species in two halophyte seed oils from Cakile maritima and Eryngium maritimum. Precursor or neutral loss scans of their polar head groups allowed the detection of molecular species within particular glycerophospholipid classes. Phosphatidylcholine was found to be the most abundant glycerophospholipid in both seed oils whereas phosphatidylethanolamine and phosphatidic acid were less abundant. Phosphatidylinositol, phosphatidylserine and phosphatidylglycerol were minor glycerophospholipids. Several molecular species within each class were detected and the main molecular species (C36:4, C36:3, C36:2, 34:2 and C34:1) were quantitatively different between the two halophytes and the different glycerophospholipids. PMID:27451187

  3. Structure analysis of peptide deformylases from Streptococcus pneumoniae, Staphylococcus aureus, Thermotoga maritima and Pseudomonas aeruginosa: snapshots of the oxygen sensitivity of peptide deformylase.

    PubMed

    Kreusch, Andreas; Spraggon, Glen; Lee, Chris C; Klock, Heath; McMullan, Daniel; Ng, Ken; Shin, Tanya; Vincent, Juli; Warner, Ian; Ericson, Christer; Lesley, Scott A

    2003-07-01

    Peptide deformylase (PDF) has received considerable attention during the last few years as a potential target for a new type of antibiotics. It is an essential enzyme in eubacteria for the removal of the formyl group from the N terminus of the nascent polypeptide chain. We have solved the X-ray structures of four members of this enzyme family, two from the Gram-positive pathogens Streptococcus pneumoniae and Staphylococcus aureus, and two from the Gram-negative bacteria Thermotoga maritima and Pseudomonas aeruginosa. Combined with the known structures from the Escherichia coli enzyme and the recently solved structure of the eukaryotic deformylase from Plasmodium falciparum, a complete picture of the peptide deformylase structure and function relationship is emerging. This understanding could help guide a more rational design of inhibitors. A structure-based comparison between PDFs reveals some conserved differences between type I and type II enzymes. Moreover, our structures provide insights into the known instability of PDF caused by oxidation of the metal-ligating cysteine residue. PMID:12823970

  4. Effect of bioflavonoids extracted from the bark of Pinus maritima on proinflammatory cytokine interleukin-1 production in lipopolysaccharide-stimulated RAW 264.7.

    PubMed

    Cho, K J; Yun, C H; Yoon, D Y; Cho, Y S; Rimbach, G; Packer, L; Chung, A S

    2000-10-01

    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 beta (IL-1 beta) production were investigated in murine macrophage cell lines. PYC exerted strong scavenging activities against reactive oxygen species generated either by H(2)O(2) or PMA in RAW 264.7 and IC-21 cells, respectively. In situ ELISA, immunoblot analysis, and competitive RT-PCR demonstrated that PYC pretreatment of LPS-stimulated RAW 264.7 cells dose-dependently reduced both the production of IL-1 beta and its mRNA levels. Furthermore, in the same cells, PYC blocked the activation of nuclear factor kappa B (NF-kappa B) and activator protein-1 (AP-1), two major transcription factors centrally involved in IL-1 beta gene expression. When RAW 264.7 cells were stimulated with LPS, the inhibitor protein I kappa B largely disappeared from cytosolic fractions. However, pretreatment of the cells with PYC abolished the LPS-induced I kappa B degradation. These results suggest that PYC can inhibit the expression of the proinflammatory cytokine IL-1 by regulating redox-sensitive transcription factors. This study may support the possibility that bioflavonoids including PYC can be used as antiinflammatory and immunosuppressive drugs based on their radical scavenging activities. PMID:11000101

  5. The N-terminal hybrid binding domain of RNase HI from Thermotoga maritima is important for substrate binding and Mg2+-dependent activity.

    PubMed

    Jongruja, Nujarin; You, Dong-Ju; Kanaya, Eiko; Koga, Yuichi; Takano, Kazufumi; Kanaya, Shigenori

    2010-11-01

    Thermotoga maritima ribonuclease H (RNase H) I (Tma-RNase HI) contains a hybrid binding domain (HBD) at the N-terminal region. To analyze the role of this HBD, Tma-RNase HI, Tma-W22A with the single mutation at the HBD, the C-terminal RNase H domain (Tma-CD) and the N-terminal domain containing the HBD (Tma-ND) were overproduced in Escherichia coli, purified and biochemically characterized. Tma-RNase HI prefers Mg(2+) to Mn(2+) for activity, and specifically loses most of the Mg(2+)-dependent activity on removal of the HBD and 87% of it by the mutation at the HBD. Tma-CD lost the ability to suppress the RNase H deficiency of an E. coli rnhA mutant, indicating that the HBD is responsible for in vivo RNase H activity. The cleavage-site specificities of Tma-RNase HI are not significantly changed on removal of the HBD, regardless of the metal cofactor. Binding analyses of the proteins to the substrate using surface plasmon resonance indicate that the binding affinity of Tma-RNase HI is greatly reduced on removal of the HBD or the mutation. These results indicate that there is a correlation between Mg(2+)-dependent activity and substrate binding affinity. Tma-CD was as stable as Tma-RNase HI, indicating that the HBD is not important for stability. The HBD of Tma-RNase HI is important not only for substrate binding, but also for Mg(2+)-dependent activity, probably because the HBD affects the interaction between the substrate and enzyme at the active site, such that the scissile phosphate group of the substrate and the Mg(2+) ion are arranged ideally.

  6. Constitutive high-level expression of a codon-optimized β-fructosidase gene from the hyperthermophile Thermotoga maritima in Pichia pastoris.

    PubMed

    Menéndez, Carmen; Martínez, Duniesky; Trujillo, Luis E; Mazola, Yuliet; González, Ernesto; Pérez, Enrique R; Hernández, Lázaro

    2013-02-01

    Enzymes for use in the sugar industry are preferred to be thermotolerant. In this study, a synthetic codon-optimized gene encoding a highly thermostable β-fructosidase (BfrA, EC 3.2.1.26) from the bacterium Thermotoga maritima was expressed in the yeast Pichia pastoris. The gradual increase of the transgene dosage from one to four copies under the control of the constitutive glyceraldehyde 3-phosphate dehydrogenase promoter had an additive effect on BfrA yield without causing cell toxicity. Maximal values of cell biomass (115 g/l, dry weight) and overall invertase activity (241 U/ml) were reached at 72 h in fed-batch fermentations using cane sugar as the main carbon source for growth. Secretion driven by the Saccharomyces cerevisiae α-factor signal peptide resulted in periplasmic retention (44 %) and extracellular release (56 %) of BfrA. The presence of N-linked oligosaccharides did not influence the optimal activity, thermal stability, kinetic properties, substrate specificity, and exo-type action mode of the yeast-secreted BfrA in comparison to the native unglycosylated enzyme. Complete inversion of cane sugar at initial concentration of 60 % (w/v) was achieved by periplasmic BfrA in undisrupted cells reacting at pH 5.5 and 70 °C, with average productivity of 4.4 g of substrate hydrolyzed per grams of biomass (wet weight) per hour. The high yield of fully active glycosylated BfrA here attained by recombinant P. pastoris in a low-cost fermentation process appears to be attractive for the large-scale production of this thermostable enzyme useful for the manufacture of inverted sugar syrup.

  7. Importance of Hydrogen Bonding in Fine Tuning the [2Fe-2S] Cluster Redox Potential of HydC from Thermotoga maritima.

    PubMed

    Birrell, James A; Laurich, Christoph; Reijerse, Edward J; Ogata, Hideaki; Lubitz, Wolfgang

    2016-08-01

    Iron-sulfur clusters form one of the largest and most diverse classes of enzyme cofactors in nature. They may serve as structural factors, form electron transfer chains between active sites and external redox partners, or form components of enzyme active sites. Their specific role is a consequence of the cluster type and the surrounding protein environment. The relative effects of these factors are not completely understood, and it is not yet possible to predict the properties of iron-sulfur clusters based on amino acid sequences or rationally tune their properties to generate proteins with new desirable functions. Here, we generate mutations in a [2Fe-2S] cluster protein, the TmHydC subunit of the trimeric [FeFe]-hydrogenase from Thermotoga maritima, to study the factors that affect its redox potential. Saturation mutagenesis of Val131 was used to tune the redox potential over a 135 mV range and revealed that cluster redox potential and electronic properties correlate with amino acid hydrophobicity and the ability to form hydrogen bonds to the cluster. Proline scanning mutagenesis between pairs of ligating cysteines was used to remove backbone amide hydrogen bonds to the cluster and decrease the redox potential by up to 132 mV, without large structural changes in most cases. However, substitution of Gly83 with proline caused a change of HydC to a [4Fe-4S] cluster protein with a redox potential of -526 mV. Together, these results confirm the importance of hydrogen bonding in tuning cluster redox potentials and demonstrate the versatility of iron-sulfur cluster protein folds at binding different types of clusters. PMID:27396836

  8. Differences between the rhizosphere microbiome of Beta vulgaris ssp. maritima-ancestor of all beet crops-and modern sugar beets.

    PubMed

    Zachow, Christin; Müller, Henry; Tilcher, Ralf; Berg, Gabriele

    2014-01-01

    The structure and function of the plant microbiome is driven by plant species and prevailing environmental conditions. Effectuated by breeding efforts, modern crops diverge genetically and phenotypically from their wild relatives but little is known about consequences for the associated microbiota. Therefore, we studied bacterial rhizosphere communities associated with the wild beet B. vulgaris ssp. maritima grown in their natural habitat soil from coastal drift lines (CS) and modern sugar beets (Beta vulgaris ssp. vulgaris) cultivated in CS and potting soil (PS) under greenhouse conditions. Analysis of 16S rRNA gene fingerprints and pyrosequencing-based amplicon libraries revealed plant genotype- and soil-specific microbiomes. Wild beet plants harbor distinct operational taxonomic units (OTUs) and a more diverse bacterial community than the domesticated sugar beet plants. Although the rhizospheres of both plant genotypes were dominated by Proteobacteria and Planctomycetes, 37.5% of dominant OTUs were additionally detected in the wild beet rhizosphere. Analysis of the cultivable fraction confirmed these plant genotype-specific differences at functional level. The proportion of isolates displayed in vitro activity against phytopathogens was lower for wild beet (≤45.8%) than for sugar beet (≤57.5%). Conversely, active isolates from the wild beet exhibited stronger ability to cope with abiotic stresses. From all samples, active isolates of Stenotrophomonas rhizophila were frequently identified. In addition, soil type-specific impacts on the composition of bacterial communities were found: Acidobacteria, Chloroflexi, and Planctomycetes were only detected in plants cultivated in CS; whereas Bacteroidetes and Proteobacteria dominated in PS. Overall, in comparison to modern sugar beets, wild beets were associated with taxonomically and functionally distinct microbiomes.

  9. Isolation and cloning of Omp alpha, a coiled-coil protein spanning the periplasmic space of the ancestral eubacterium Thermotoga maritima.

    PubMed Central

    Engel, A M; Cejka, Z; Lupas, A; Lottspeich, F; Baumeister, W

    1992-01-01

    We have discovered a new oligomeric protein component associated with the outer membrane of the ancestral eubacterium Thermotoga maritima. In electron micrographs, the protein, Omp alpha, appears as a rod-shaped spacer that spans the periplasm, connecting the outer membrane to the inner cell body. Purification, biochemical characterization and sequencing of Omp alpha suggest that it is a homodimer composed of two subunits of 380 amino acids with a calculated M(r) of 43,000 and a pI of 4.54. The sequence of the omp alpha gene indicates a tripartite organization of the protein with a globular NH2-terminal domain of 64 residues followed by a putative coiled-coil segment of 300 residues and a COOH-terminal, membrane-spanning segment. The predicted length of the coiled-coil segment (45 nm) correlates closely with the spacing between the inner and outer membranes. Despite sequence similarity to a large number of coiled-coil proteins and high scores in a coiled-coil prediction algorithm, the sequence of the central rod-shaped domain of Omp alpha does not have the typical 3.5 periodicity of coiled-coil proteins but rather has a periodicity of 3.58 residues. Such a periodicity was also found in the central domain of staphylococcal M protein and beta-giardin and might be indicative of a subclass of fibrous proteins with packing interactions that are distinct from the ones seen in other two-stranded coiled-coils. Images PMID:1330536

  10. Constitutive high-level expression of a codon-optimized β-fructosidase gene from the hyperthermophile Thermotoga maritima in Pichia pastoris.

    PubMed

    Menéndez, Carmen; Martínez, Duniesky; Trujillo, Luis E; Mazola, Yuliet; González, Ernesto; Pérez, Enrique R; Hernández, Lázaro

    2013-02-01

    Enzymes for use in the sugar industry are preferred to be thermotolerant. In this study, a synthetic codon-optimized gene encoding a highly thermostable β-fructosidase (BfrA, EC 3.2.1.26) from the bacterium Thermotoga maritima was expressed in the yeast Pichia pastoris. The gradual increase of the transgene dosage from one to four copies under the control of the constitutive glyceraldehyde 3-phosphate dehydrogenase promoter had an additive effect on BfrA yield without causing cell toxicity. Maximal values of cell biomass (115 g/l, dry weight) and overall invertase activity (241 U/ml) were reached at 72 h in fed-batch fermentations using cane sugar as the main carbon source for growth. Secretion driven by the Saccharomyces cerevisiae α-factor signal peptide resulted in periplasmic retention (44 %) and extracellular release (56 %) of BfrA. The presence of N-linked oligosaccharides did not influence the optimal activity, thermal stability, kinetic properties, substrate specificity, and exo-type action mode of the yeast-secreted BfrA in comparison to the native unglycosylated enzyme. Complete inversion of cane sugar at initial concentration of 60 % (w/v) was achieved by periplasmic BfrA in undisrupted cells reacting at pH 5.5 and 70 °C, with average productivity of 4.4 g of substrate hydrolyzed per grams of biomass (wet weight) per hour. The high yield of fully active glycosylated BfrA here attained by recombinant P. pastoris in a low-cost fermentation process appears to be attractive for the large-scale production of this thermostable enzyme useful for the manufacture of inverted sugar syrup. PMID:22821437

  11. Differences between the rhizosphere microbiome of Beta vulgaris ssp. maritima-ancestor of all beet crops-and modern sugar beets.

    PubMed

    Zachow, Christin; Müller, Henry; Tilcher, Ralf; Berg, Gabriele

    2014-01-01

    The structure and function of the plant microbiome is driven by plant species and prevailing environmental conditions. Effectuated by breeding efforts, modern crops diverge genetically and phenotypically from their wild relatives but little is known about consequences for the associated microbiota. Therefore, we studied bacterial rhizosphere communities associated with the wild beet B. vulgaris ssp. maritima grown in their natural habitat soil from coastal drift lines (CS) and modern sugar beets (Beta vulgaris ssp. vulgaris) cultivated in CS and potting soil (PS) under greenhouse conditions. Analysis of 16S rRNA gene fingerprints and pyrosequencing-based amplicon libraries revealed plant genotype- and soil-specific microbiomes. Wild beet plants harbor distinct operational taxonomic units (OTUs) and a more diverse bacterial community than the domesticated sugar beet plants. Although the rhizospheres of both plant genotypes were dominated by Proteobacteria and Planctomycetes, 37.5% of dominant OTUs were additionally detected in the wild beet rhizosphere. Analysis of the cultivable fraction confirmed these plant genotype-specific differences at functional level. The proportion of isolates displayed in vitro activity against phytopathogens was lower for wild beet (≤45.8%) than for sugar beet (≤57.5%). Conversely, active isolates from the wild beet exhibited stronger ability to cope with abiotic stresses. From all samples, active isolates of Stenotrophomonas rhizophila were frequently identified. In addition, soil type-specific impacts on the composition of bacterial communities were found: Acidobacteria, Chloroflexi, and Planctomycetes were only detected in plants cultivated in CS; whereas Bacteroidetes and Proteobacteria dominated in PS. Overall, in comparison to modern sugar beets, wild beets were associated with taxonomically and functionally distinct microbiomes. PMID:25206350

  12. 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.

  13. Contrasting effects of ecosystem engineering by the cordgrass Spartina maritima and the sandprawn Callianassa kraussi in a marine-dominated lagoon

    NASA Astrophysics Data System (ADS)

    Pillay, D.; Branch, G. M.; Dawson, J.; Henry, D.

    2011-01-01

    Ecosystem engineering by plants and animals significantly influences community structure and the physico-chemical characteristics of marine habitats. In this paper we document the contrasting effects of ecosystem engineering by the cordgrass Spartina maritima and the burrowing sandprawn Callianassa kraussi on physico-chemical characteristics, microflora, macrofaunal community structure and morphological attributes in the high shore intertidal sandflats of Langebaan Lagoon, a marine-dominated system on the west coast of South Africa. Comparisons were made at six sites in the lagoon within Spartina and Callianassa beds, and in a "bare zone" of sandflat between these two habitats that lacks both sandprawns and cordgrass. Sediments in Spartina habitats were consolidated by the root-shoot systems of the cordgrass, leading to low sediment penetrability, while sediments in beds of C. kraussi were more penetrable, primarily due to the destabilising effects of sandprawn bioturbation. Sediments in the "bare zone" had intermediate to low values of penetrability. Sediment organic content was lowest in bare zones and greatest in Spartina beds, while sediment chl- a levels were greatest on bare sand, but were progressively reduced in the Spartina and Callianassa beds. These differences among habitats induced by ecosystem engineering in turn affected the macrofauna. Community structure was different between all three habitats sampled, with species richness being surprisingly greater in Callianassa beds than either the bare zone or Spartina beds. In general, the binding of surface sediments by the root systems of Spartina favoured rigid-bodied, surface-dwelling and tube-building species, while the destabilising effect of bioturbation by C. kraussi favoured burrowing species. The contrasting effects of these ecosystem engineers suggest that they play important roles in increasing habitat heterogeneity. Importantly, the role of bioturbation by C. kraussi in enhancing macrofaunal

  14. Effect of dietary supplementation with Suaeda maritima on blood physiology, innate immune response, and disease resistance in olive flounder against Miamiensis avidus.

    PubMed

    Harikrishnan, Ramasamy; Kim, Ju-Sang; Kim, Man-Chul; Dharaneedharan, Subramanian; Kim, Dong-Hwi; Hong, Seung-Hyun; Song, Chang-Young; Balasundaram, Chellam; Heo, Moon-Soo

    2012-06-01

    The effect of Suaeda maritima enriched diet on blood physiology, innate immune response, and disease resistance in olive flounder Paralichythys olivaceus against Miamiensis avidus on weeks 1, 2, and 4 was investigated. Feeding with any enriched diet and then challenging with M. avidus significantly increased white blood cells (WBC) on weeks 2 and 4; the red blood cells (RBC) significantly increased with 0.1% and 1.0% enriched diets on week 4. The hemoglobin (Hb) and hematocrit (Ht) levels significantly increased when fed with 0.1% and 1.0% supplementation diets on weeks 2 and 4. The mean corpuscular volume (MCV) did not significantly vary with any diet and time; however the mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) significantly increased with 0.1% and 1.0% supplementation diets on weeks 2 and 4. The leukocytes such as lymphocytes (Lym), monocytes (Mon), neutrophils (Neu) and biochemical parameters such as total protein (TP), glucose (GLU), and calcium (CAL) levels significantly increased in 0.1% and 1.0% supplementation diet fed groups on weeks 2 and 4. The serum lysozyme activity was significantly enhanced in 0.1% and 1.0% supplementation diet fed groups from weeks 1 to 4 when compared to the control (0% herbal extract enriched diet). The scuticocidal activity and respiratory burst activity were significantly enhanced when fish were fed with 0.1% and 1.0% supplementation diets from weeks 2 and 4. The protective effect in terms of cumulative mortality (50% and 40%) was low in groups on being fed with 0.1% and 1.0% supplemented diet. Therefore the present study suggested that 0.1% and 1.0% S. maritime-supplemented diets protect the hematological and biochemical parameters, improving the innate immunity, affording protection disease from M. avidus infection in olive flounder. PMID:22490817

  15. A loose domain swapping organization confers a remarkable stability to the dimeric structure of the arginine binding protein from Thermotoga maritima.

    PubMed

    Ruggiero, Alessia; Dattelbaum, Jonathan D; Staiano, Maria; Berisio, Rita; D'Auria, Sabato; Vitagliano, Luigi

    2014-01-01

    The arginine binding protein from Thermatoga maritima (TmArgBP), a substrate binding protein (SBP) involved in the ABC system of solute transport, presents a number of remarkable properties. These include an extraordinary stability to temperature and chemical denaturants and the tendency to form multimeric structures, an uncommon feature among SBPs involved in solute transport. Here we report a biophysical and structural characterization of the TmArgBP dimer. Our data indicate that the dimer of the protein is endowed with a remarkable stability since its full dissociation requires high temperature as well as SDS and urea at high concentrations. In order to elucidate the atomic level structural properties of this intriguing protein, we determined the crystallographic structures of the apo and the arginine-bound forms of TmArgBP using MAD and SAD methods, respectively. The comparison of the liganded and unliganded models demonstrates that TmArgBP tertiary structure undergoes a very large structural re-organization upon arginine binding. This transition follows the Venus Fly-trap mechanism, although the entity of the re-organization observed in TmArgBP is larger than that observed in homologous proteins. Intriguingly, TmArgBP dimerizes through the swapping of the C-terminal helix. This dimer is stabilized exclusively by the interactions established by the swapping helix. Therefore, the TmArgBP dimer combines a high level of stability and conformational freedom. The structure of the TmArgBP dimer represents an uncommon example of large tertiary structure variations amplified at quaternary structure level by domain swapping. Although the biological relevance of the dimer needs further assessments, molecular modelling suggests that the two TmArgBP subunits may simultaneously interact with two distinct ABC transporters. Moreover, the present protein structures provide some clues about the determinants of the extraordinary stability of the biomolecule. The availability of

  16. A loose domain swapping organization confers a remarkable stability to the dimeric structure of the arginine binding protein from Thermotoga maritima.

    PubMed

    Ruggiero, Alessia; Dattelbaum, Jonathan D; Staiano, Maria; Berisio, Rita; D'Auria, Sabato; Vitagliano, Luigi

    2014-01-01

    The arginine binding protein from Thermatoga maritima (TmArgBP), a substrate binding protein (SBP) involved in the ABC system of solute transport, presents a number of remarkable properties. These include an extraordinary stability to temperature and chemical denaturants and the tendency to form multimeric structures, an uncommon feature among SBPs involved in solute transport. Here we report a biophysical and structural characterization of the TmArgBP dimer. Our data indicate that the dimer of the protein is endowed with a remarkable stability since its full dissociation requires high temperature as well as SDS and urea at high concentrations. In order to elucidate the atomic level structural properties of this intriguing protein, we determined the crystallographic structures of the apo and the arginine-bound forms of TmArgBP using MAD and SAD methods, respectively. The comparison of the liganded and unliganded models demonstrates that TmArgBP tertiary structure undergoes a very large structural re-organization upon arginine binding. This transition follows the Venus Fly-trap mechanism, although the entity of the re-organization observed in TmArgBP is larger than that observed in homologous proteins. Intriguingly, TmArgBP dimerizes through the swapping of the C-terminal helix. This dimer is stabilized exclusively by the interactions established by the swapping helix. Therefore, the TmArgBP dimer combines a high level of stability and conformational freedom. The structure of the TmArgBP dimer represents an uncommon example of large tertiary structure variations amplified at quaternary structure level by domain swapping. Although the biological relevance of the dimer needs further assessments, molecular modelling suggests that the two TmArgBP subunits may simultaneously interact with two distinct ABC transporters. Moreover, the present protein structures provide some clues about the determinants of the extraordinary stability of the biomolecule. The availability of

  17. A Loose Domain Swapping Organization Confers a Remarkable Stability to the Dimeric Structure of the Arginine Binding Protein from Thermotoga maritima

    PubMed Central

    Ruggiero, Alessia; Dattelbaum, Jonathan D.; Staiano, Maria; Berisio, Rita; D'Auria, Sabato; Vitagliano, Luigi

    2014-01-01

    The arginine binding protein from Thermatoga maritima (TmArgBP), a substrate binding protein (SBP) involved in the ABC system of solute transport, presents a number of remarkable properties. These include an extraordinary stability to temperature and chemical denaturants and the tendency to form multimeric structures, an uncommon feature among SBPs involved in solute transport. Here we report a biophysical and structural characterization of the TmArgBP dimer. Our data indicate that the dimer of the protein is endowed with a remarkable stability since its full dissociation requires high temperature as well as SDS and urea at high concentrations. In order to elucidate the atomic level structural properties of this intriguing protein, we determined the crystallographic structures of the apo and the arginine-bound forms of TmArgBP using MAD and SAD methods, respectively. The comparison of the liganded and unliganded models demonstrates that TmArgBP tertiary structure undergoes a very large structural re-organization upon arginine binding. This transition follows the Venus Fly-trap mechanism, although the entity of the re-organization observed in TmArgBP is larger than that observed in homologous proteins. Intriguingly, TmArgBP dimerizes through the swapping of the C-terminal helix. This dimer is stabilized exclusively by the interactions established by the swapping helix. Therefore, the TmArgBP dimer combines a high level of stability and conformational freedom. The structure of the TmArgBP dimer represents an uncommon example of large tertiary structure variations amplified at quaternary structure level by domain swapping. Although the biological relevance of the dimer needs further assessments, molecular modelling suggests that the two TmArgBP subunits may simultaneously interact with two distinct ABC transporters. Moreover, the present protein structures provide some clues about the determinants of the extraordinary stability of the biomolecule. The availability of

  18. 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.

  19. 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.

  20. Helical shifts generate two distinct conformers in the atomic resolution structure of the CheA phosphotransferase domain from Thermotoga maritima.

    PubMed

    Quezada, Cindy M; Gradinaru, Cristian; Simon, Melvin I; Bilwes, Alexandrine M; Crane, Brian R

    2004-08-27

    Helical histidine phosphotransferase (HPt) domains play a central role in many aspects of bacterial signal transduction. The 0.98 A resolution crystallographic structure of the amino-terminal HPt domain (P1) from the chemotaxis kinase CheA of Thermotoga maritima reveals a remarkable degree of structural heterogeneity within a four-helix bundle. Two of the four helices have alternate main-chain conformations that differ by a 1.3-1.7A shift along the bundle axis. These dual conformers were only resolved with atomic resolution diffraction data and their inclusion significantly improved refinement statistics. Neither conformer optimizes packing within the helical core, consistent with their nearly equal refined occupancies. Altered hydrogen bonding within an inter-helical loop may facilitate transition between conformers. Two discrete structural states rather than a continuum of closely related conformations indicates an energetic barrier to conversion between conformers in the crystal at 100K, although many more states are expected in solution at physiological temperatures. Anisotropic atomic thermal B factors within the two conformers indicate modest overall atomic displacement that is largest perpendicular to the helical bundle and not along the direction of apparent motion. Despite the conformational heterogeneity of P1 in the crystal at low temperature, the protein displays high thermal stability in solution (T(m)=100 degrees C). Addition of a variable C-terminal region that corresponds to a mobile helix in other CheA structures significantly narrows the temperature width of the unfolding transition and may affect domain dynamics. Helices that compose the kinase recognition site and contain the phospho-accepting His45 do not have alternate conformations. In this region, atomic resolution provides detailed structural parameters for a conserved hydrogen-bonding network that tunes the reactivity of His45. A neighboring glutamate (E67), essential for

  1. High-resolution X-ray structure of the DNA-binding protein HU from the hyper-thermophilic Thermotoga maritima and the determinants of its thermostability.

    PubMed

    Christodoulou, Evangelos; Rypniewski, Wojciech R; Vorgias, Constantinos R E

    2003-04-01

    The histone-like DNA-binding proteins (HU) are a convenient model for studying factors affecting thermostability because of their relatively simple, easily comparable structures, their common function, and their presence in organisms of widely differing thermostability. We report the determination of the high-resolution structure (1.53 A) at 273 K and 100 K of the HU protein from the hyper-thermophilic eubacterium Thermotoga maritima(HU Tmar, T(m)=80.5 degrees C). The structural data presented clearly show that the HU Tmar has a fold similar to its thermophilic homologue HU from Bacillus stearothermophilus (HU Bst). Based on primary structure analysis, as well as on the results of mutational analysis of HU Bst ( T(m)=61.6 degrees C) and Bacillus subtilis (HU Bsu, T(m)=39.7 degrees C), we have designed and produced several single and combined mutations to study their effect on the thermostability of the recombinant HU Tmar. Among others, the triplet mutant HU Tmar-G15E/E34D/V42I ( T(m)=35.9 degrees C) has converted the extreme thermophilic protein HU Tmar to mesophilic, like HU Bsu. In an attempt to analyze the various mutants of HU Tmar, we crystallized the point mutation HU Tmar-E34D, in which Glu34 was replaced by Asp, similar to the mesophilic HU Bsu. The mutant has T(m)=72.9 degrees C, as measured by circular dichroism, 7.6 degrees C lower than the wild type. The crystal structure of HU Tmar-E34D was determined at 100 K and refined at 1.72 A resolution. A comparison with the wild-type structures clearly shows that two hydrogen bonds have been disrupted between Glu34 from one subunit and Thr13 from the other subunit, and vice versa. Our analysis points to this as the prime cause of the destabilization compared to the wild type. The three new structures were compared, together with the X-ray structure of a similar protein, HU Bst, with the aim of relating their structural properties and different thermal stability. The presented results show that the HU Tmar

  2. Thermotoga maritima ribonuclease III. Characterization of thermostable biochemical behavior and analysis of conserved base pairs that function as reactivity epitopes for the Thermotoga 23S rRNA precursor.

    PubMed

    Nathania, Lilian; Nicholson, Allen W

    2010-08-24

    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 have 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 approximately 40-70 degrees C, with significant activity at 95 degrees C. Tm-RNase III cleavage of substrate is optimally supported by Mg(2+) at >or=1 mM concentrations. Mn(2+), Co(2+), and Ni(2+) also support activity but with reduced efficiencies. The enzyme functions optimally at pH 8 and approximately 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 Escherichia 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.

  3. Exploring Phylogeographic Congruence in a Continental Island System

    PubMed Central

    Goldberg, Julia; Trewick, Steven A.

    2011-01-01

    A prediction in phylogeographic studies is that patterns of lineage diversity and timing will be similar within the same landscape under the assumption that these lineages have responded to past environmental changes in comparable ways. Eight invertebrate taxa from four different orders were included in this study of mainland New Zealand and Chatham Islands lineages to explore outcomes of island colonization. These comprised two orthopteran genera, one an endemic forest-dwelling genus of cave weta (Rhaphidophoridae, Talitropsis) and the other a grasshopper (Acrididae, Phaulacridum) that inhabits open grassland; four genera of Coleoptera including carabid beetles (Mecodema), stag beetles (Geodorcus), weevils (Hadramphus) and clickbeetles (Amychus); the widespread earwig genus Anisolabis (Dermaptera) that is common on beaches in New Zealand and the Chatham Islands, and an endemic and widespread cockroach genus Celatoblatta (Blattodea). Mitochondrial DNA data were used to reconstruct phylogeographic hypotheses to compare among these taxa. Strikingly, despite a maximum age of the Chathams of ∼4 million years there is no concordance among these taxa, in the extent of genetic divergence and partitioning between Chatham and Mainland populations. Some Chatham lineages are represented by insular endemics and others by haplotypes shared with mainland populations. These diverse patterns suggest that combinations of intrinsic (taxon ecology) and extrinsic (extinction and dispersal) factors can result in apparently very different biogeographic outcomes. PMID:26467734

  4. 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

    ... out of the water onto rocks or vegetation to molt into winged adults, typically remaining close to the... common and conspicuous native Hawaiian insects. Some species commonly inhabited water gardens in... FR 21664). Candidate species are those taxa for which the Service has sufficient information on...

  5. 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, ...

  6. Entomological fauna from Reserva Biológica do Atol das Rocas, RN, Brazil: I. Morphospecies composition.

    PubMed

    Almeida; Marchon-Silva; Ribeiro; Serpa-Filho; Almeida; Costa

    2000-05-01

    Atol das Rocas, the unique atoll in the South-western Atlantic, is located 144 nautical miles (266 Km) northeast from the city of Natal, NE Brazil and 80 nautical miles from Arquipélago de Fernando de Noronha, with geographic co-ordinates 3 masculine51'S and 33 masculine49"W. It's of volcanic origin and coralline formation. The reef is ellipsoid, its largest axis (E-W) is approximately 3.7 km long, and the shortest (N-S) is 2.5 km. Inside the lagoon, there are two islands: the Ilha do Farol and Ilha do Cemitério, which comprehend 7.2 Km2 of emerged area. The Atol das Rocas lodges 143,000 birds, mainly by Sula dactilatra, S. leucogaster, Anous stolidus, A. minuta and Sterna fuscata. Due to their remote location, the islands remain largely undisturbed by the human activities. Aiming to a first characterization of the entomological diversity and the general trophic niches of atoll's entomofauna, three collects were made (1994, 1995 and 1996) utilizing several methods for a wide sample. One thousand six hundred and six insect specimens were collected belonging to eight orders: 1. Coleoptera - 333 individuals of Dermestidae (Dermestes cadaverinus); Tenebrionidae (Phaleria testacea and morphospecies) and Curculionidae (one morphospecies); 2. Dermaptera - 50 individuals of Carcinophoridae (Anisolabis maritima); 3. Diptera - 281 individuals of Ephydridae (Scatella sp. and Hecamede sp.) and Hippoboscidae (one morphospecies); 4. Hymenoptera - 45 individuals of Formicidae (Brachymyrmex sp.); 5. Lepidoptera - 111 individuals of Microlepidoptera (one morphospecies); 6. Mallophaga - 18 individuals in birds (two morphospecies); 7. Orthoptera - 237 individuals of Acrididae (Schistocerca cancellata), Tridactylidae (one morphospecies) and Blattidae (three morphospecies); 8. Thysanoptera -531 individuals (one morphospecies). Also were collected 112 individuals of Arachnida. The taxa of the Order Araneae were represented by the families: 1. Miturgidae (Cheiracanthium inclusum); 2

  7. Cytotoxicity of the Sesquiterpene Lactones Neoambrosin and Damsin from Ambrosia maritima Against Multidrug-Resistant Cancer Cells

    PubMed Central

    Saeed, Mohamed; Jacob, Stefan; Sandjo, Louis P.; Sugimoto, Yoshikazu; Khalid, Hassan E.; Opatz, Till; Thines, Eckhard; Efferth, Thomas

    2015-01-01

    Multidrug resistance is a prevailing phenomenon leading to chemotherapy treatment failure in cancer patients. In the current study two known cytotoxic pseudoguaianolide sesquiterpene lactones; neoambrosin (1) and damsin (2) that circumvent MDR were identified. The two cytotoxic compounds were isolated using column chromatography, characterized using 1D and 2D NMR, MS, and compared with literature values. The isolated compounds were investigated for their cytotoxic potential using resazurin assays and thereafter confirmed with immunoblotting and in silico studies. MDR cells overexpressing ABC transporters (P-glycoprotein, BCRP, ABCB5) did not confer cross-resistance toward (1) and (2), indicating that these compounds are not appropriate substrates for any of the three ABC transporters analyzed. Resistance mechanisms investigated also included; the loss of the functions of the TP53 and the mutated EGFR. The HCT116 p53-/- cells were sensitive to 1 but resistant to 2. It was interesting to note that resistant cells transfected with oncogenic ΔEGFR exhibited hypersensitivity CS toward (1) and (2) (degrees of resistances were 0.18 and 0.15 for (1) and (2), respectively). Immunoblotting and in silico analyses revealed that 1 and 2 silenced c-Src kinase activity. It was hypothesized that inhibition of c-Src kinase activity may explain CS in EGFR-transfected cells. In conclusion, the significant cytotoxicity of 1 and 2 against different drug-resistant tumor cell lines indicate that they may be promising candidates to treat refractory tumors. PMID:26617519

  8. Local and global influences on population declines of coastal waders: Purple Sandpiper Calidris maritima numbers in the Moray Firth, Scotland

    NASA Astrophysics Data System (ADS)

    Summers, Ron W.; Foster, Simon; Swann, Bob; Etheridge, Brian

    2012-05-01

    Declines in numbers by several wader species in Britain have been linked to climate change, but the mechanism for the declines has rarely been explored. Britain lies at the northern end of the East Atlantic Flyway, and supports 1.3 million out of the Flyway's 8.5 million coastal waders (Charadrii) in winter and the Purple Sandpiper is one of the species whose numbers have declined. Here, we examine the dynamics of the decline as observed in the Moray Firth, northeast Scotland, investigating whether the decline was due to poorer apparent survival (return rate) or poorer recruitment of young birds. The maximum number in the Moray Firth declined from 860 in 1987/88 to 236 in 2006/07, with some increase during winters 2007/08 and 2008/09. At the three main high-tide roosts (Balintore, Lossiemouth and Buckie) the maximum combined number declined from 574 to 90. Changes in survival and recruitment (percentage of first-year birds) were examined at these roosts from captured samples, which were ringed and recaptured. There were no significant changes between winters in survival rates, nor were there differences between the survival rates of age groups (first-year and adult) or bill size groups, which represented birds of different sex and breeding origin. Annual survival estimates for the three roosts ranged from 72 to 77%. The percentage of first-year birds varied among roosts and years; the lowest values were during the late 1980s/early 1990s and early 2000s. A free-running population model incorporating varying percentages of first-year birds and constant mortality for each roost provided a plausible explanation for the decline. Although modelled numbers followed the observed pattern, a discrepancy in one year was carried forward in subsequent years, so that the fit with the observed numbers was parallel rather than similar. However, it seems that the decline in numbers was largely due to poorer recruitment. We discuss whether breeding success had declined, whether the population had responded to changes in the local sewage treatment systems, which could affect invertebrate food for Purple Sandpipers, or whether fewer birds chose to winter in Scotland. The Moray Firth population is derived from Norway and possibly Canada, and there is evidence that the Norwegian population was disproportionately affected. The reason for poor recruitment requires further study, and other wader species require examination to test if poor recruitment is a common feature of decline in numbers.

  9. Cytotoxicity of the Sesquiterpene Lactones Neoambrosin and Damsin from Ambrosia maritima Against Multidrug-Resistant Cancer Cells.

    PubMed

    Saeed, Mohamed; Jacob, Stefan; Sandjo, Louis P; Sugimoto, Yoshikazu; Khalid, Hassan E; Opatz, Till; Thines, Eckhard; Efferth, Thomas

    2015-01-01

    Multidrug resistance is a prevailing phenomenon leading to chemotherapy treatment failure in cancer patients. In the current study two known cytotoxic pseudoguaianolide sesquiterpene lactones; neoambrosin (1) and damsin (2) that circumvent MDR were identified. The two cytotoxic compounds were isolated using column chromatography, characterized using 1D and 2D NMR, MS, and compared with literature values. The isolated compounds were investigated for their cytotoxic potential using resazurin assays and thereafter confirmed with immunoblotting and in silico studies. MDR cells overexpressing ABC transporters (P-glycoprotein, BCRP, ABCB5) did not confer cross-resistance toward (1) and (2), indicating that these compounds are not appropriate substrates for any of the three ABC transporters analyzed. Resistance mechanisms investigated also included; the loss of the functions of the TP53 and the mutated EGFR. The HCT116 p53(-/-) cells were sensitive to 1 but resistant to 2. It was interesting to note that resistant cells transfected with oncogenic ΔEGFR exhibited hypersensitivity CS toward (1) and (2) (degrees of resistances were 0.18 and 0.15 for (1) and (2), respectively). Immunoblotting and in silico analyses revealed that 1 and 2 silenced c-Src kinase activity. It was hypothesized that inhibition of c-Src kinase activity may explain CS in EGFR-transfected cells. In conclusion, the significant cytotoxicity of 1 and 2 against different drug-resistant tumor cell lines indicate that they may be promising candidates to treat refractory tumors. PMID:26617519

  10. The feasibility and efficacy of early-season releases of a generalist predator (Forficula auricularia L.) to control populations of the RAA (Dysaphis plantaginea Passerini) in Southeastern France.

    PubMed

    Dib, H; Jamont, M; Sauphanor, B; Capowiez, Y

    2016-04-01

    Augmentative biological control is not commonly used in commercial orchards. We used an exclusion system to evaluate the potential of early-season releases of the European earwig (Forficula auricularia L., Dermaptera: Forficulidae) for control of the rosy apple aphid (Dysaphis plantaginea Passerini, Hemiptera: Aphididae) in the spring of 2009 in two pesticide-free apple orchards. In order to conduct this experiment we successfully reared earwigs with a high survival rate of nymphs (more than 96%) which may have commercial application. There were three treatments in the study: (i) a 'release treatment' where we confined the released earwigs in the canopy by using a barrier system; (ii) an 'exclusion treatment' where we blocked free access of earwigs into the canopy using the same barrier system; and (iii) a 'control treatment' that represented the natural situation. Contrary to expectations, earwig releases did not reduce D. plantaginea populations. In general, the abundance of natural enemies and their groups did not differ significantly among treatments, except for earwigs. We observed that the exclusion systems we used successfully kept both earwigs and ants away from tree canopies; total numbers on trees in the 'exclusion treatment' were significantly lower than on the other two treatments. Due to the complexity and difficulty of evaluating augmentative releases of natural enemies in open orchard conditions, we conclude that new technical approaches to control site conditions are needed when conducting such studies. PMID:26780826

  11. 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.

  12. Low level of gene flow from cultivated beets (Beta vulgaris L. ssp. vulgaris) into Danish populations of sea beet (Beta vulgaris L. ssp. maritima (L.) Arcangeli).

    PubMed

    Andersen, N S; Siegismund, H R; Meyer, V; Jørgensen, R B

    2005-04-01

    Gene flow from sugar beets to sea beets occurs in the seed propagation areas in southern Europe. Some seed propagation also takes place in Denmark, but here the crop-wild gene flow has not been investigated. Hence, we studied gene flow to sea beet populations from sugar beet lines used in Danish seed propagation areas. A set of 12 Danish, two Swedish, one French, one Italian, one Dutch, and one Irish populations of sea beets, and four lines of sugar beet were analysed. To evaluate the genetic variation and gene flow, eight microsatellite loci were screened. This analysis revealed hybridization with cultivated beet in one of the sea beet populations from the centre of the Danish seed propagation area. Triploid hybrids found in this population were verified with flow cytometry. Possible hybrids or introgressed plants were also found in the French and Italian populations. However, individual assignment test using a Bayesian method provided 100% assignment success of diploid individuals into their correct subspecies of origin, and a Bayesian Markov chain Monte Carlo (MC MC) approach revealed clear distinction of individuals into groups according to their subspecies of origin, with a zero level of genetic admixture among subspecies. This underlines that introgression beyond the first hybridization is not extensive. The overall pattern of genetic distance and structure showed that Danish and Swedish sea beet populations were closely related to each other, and they are both more closely related to the population from Ireland than to the populations from France, the Netherlands, and Italy.

  13. The linkage disequilibrium between chloroplast DNA and mitochondrial DNA haplotypes in Beta vulgaris ssp. maritima (L.): the usefulness of both genomes for population genetic studies.

    PubMed

    Desplanque, B; Viard, F; Bernard, J; Forcioli, D; Saumitou-Laprade, P; Cuguen, J; Van Dijk, H

    2000-02-01

    The structure and evolution of the plant mitochondrial genome may allow recurrent appearance of the same mitochondrial variants in different populations. Whether the same mitochondrial variant is distributed by migration or appears recurrently by mutation (creating homoplasy) in different populations is an important question with regard to the use of these markers for population genetic analyses. The genetic association observed between chloroplasts and mitochondria (i.e. two maternally inherited cytoplasmic genomes) may indicate whether or not homoplasy occurs in the mitochondrial genome. Four-hundred and fourteen individuals sampled in wild populations of beets from France and Spain were screened for their mitochondrial and chloroplast polymorphisms. Mitochondrial DNA (mtDNA) polymorphism was investigated with restriction fragment length polymorphism (RFLP) and chloroplast DNA (cpDNA) polymorphism was investigated with polymerase chain reaction PCR-RFLP, using universal primers for the amplification. Twenty and 13 variants for mtDNA and cpDNA were observed, respectively. Most exhibited a widespread geographical distribution. As a very strong linkage disequilibrium was estimated between mtDNA and cpDNA haplotypes, a high rate of recurrent mutation was excluded for the mitochondrial genome of beets. Identical mitochondrial variants found in populations of different regions probably occurred as a result of migration. We concluded from this study that mtDNA is a tool as valuable as cpDNA when a maternal marker is needed for population genetics analyses in beet on a large regional scale.

  14. 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

  15. 78 FR 47827 - Unblocking of Specially Designated Nationals and Blocked Persons Pursuant to the Cuban Assets...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-06

    ...) (vessel) . 15. LAS COLORADOS Unknown vessel type (Naviera Maritima de Arosa, Spain) (vessel) . 16. LAURA I... Enterprises, Inc., Panama) (vessel) . 21. PALMA MOCHA Unknown vessel type (Naviera Maritima de Arosa, Spain) (vessel) . 22. PINO DEL AGUA Unknown vessel type (Naviera Maritima de Arosa, Spain) (vessel) . 23. RAHIM...

  16. 31 CFR Appendix B to Chapter V - Alphabetical Listing of Vessels That Are the Property of Blocked Persons or Specially Designated...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Iraqi State Enterprise for Water Transport ALEGRIA DE PIO CUBA Naviera Maritima de Arosa, Spain ALFARABI..., Spain LAURA I CUBA Panama Container ship 2213 1843 HP7988 Naviera Polovina S.A. fka LAURA LILAC ISLANDS... Org. of Iraqi Ports PALMA MOCHA CUBA Naviera Maritima de Arosa, Spain PILOT 393 IRAQ Iraq Service...

  17. 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.

  18. An offspring signal of quality affects the timing of future parental reproduction

    PubMed Central

    Mas, Flore; Kölliker, Mathias

    2011-01-01

    Solicitation signals by offspring are well known to influence parental behaviour, and it is commonly assumed that this behavioural effect translates into an effect on residual reproduction of parents. However, this equivalence assumption concerning behavioural and reproductive effects caused by offspring signals remains largely untested. Here, we tested the effect of a chemical offspring signal of quality on the relative timing and amount of future reproduction in the European earwig (Forficula auricularia). We manipulated the nutritional condition of earwig nymphs and exposed females to their extract, or to solvent as a control. There were no significant main effects of exposure treatment on 2nd clutch production, but exposure to extracts of well-fed nymphs induced predictable timing of the 2nd relative to the 1st clutch. This result demonstrates for the first time that an offspring signal per se, in the absence of any maternal behaviour, affects maternal reproductive timing, possibly through an effect on maternal reproductive physiology. PMID:21208942

  19. Which insect species numerically respond to allochthonous inputs?

    NASA Astrophysics Data System (ADS)

    Sugiura, Shinji; Ikeda, Hiroshi

    2013-08-01

    Herons (Ardeidae) frequently breed in inland forests and provide organic material in the form of carcasses of prey (that they drop) and chicks (that die) to the forest floor. Such allochthonous inputs of organic materials are known to increase arthropod populations in forests. However, the exact species that show numerical responses to allochthonous inputs in heron breeding colonies remains unclear. Very few studies have clarified which factors determine numerical responses in individual species. We used pitfall and baited traps to compare the densities of arthropods between forest patches in heron breeding colonies (five sites) and areas outside of colonies (five sites) in central Japan. The density of all arthropods was not significantly different between colonies and non-colony areas. However, significant differences between colonies and non-colony areas were found in four arthropod groups. Earwigs (Dermaptera: Anisolabididae), hister beetles (Coleoptera: Histeridae), and carrion beetles (Coleoptera: Silphidae) were more abundant in colonies, while ants (Hymenoptera: Formicidae) were less abundant in colonies. We detected numerical responses to heron breeding in two earwig, one histerid, five silphid, and one ant species. Chick and prey carcasses from herons may have directly led to increases in consumer populations such as earwigs, histerids, and silphids in colonies, while microenvironmental changes caused by heron breeding may have reduced ant abundance. In the Silphidae, five species showed numerical responses to allochthonous inputs, and the other two species did not. Numerical responses in individual species may have been determined by life history traits such as reproductive behaviour.

  20. Agronomy of strip intercropping broccoli with alyssum for biological control of aphids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic broccoli growers in California typically control aphids by intercropping broccoli with strips of alyssum (Lobularia maritima (L.) Desv.) which attracts hoverflies (Diptera: Syrphidae) that are important predators of aphids. A three year study with transplanted organic broccoli in Salinas, ...

  1. Cues of maternal condition influence offspring selfishness.

    PubMed

    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

  2. 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

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

    PubMed Central

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

    2014-01-01

    Abstract 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

  4. 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.

  5. Sugar Transport and Metabolism in Thermotoga

    SciTech Connect

    Noll, Kenneth M.; Romano, Antonio H.

    2003-02-11

    The work conducted under this grant demonstrated that the hyperthermophilic bacterium Thermotoga neapolitana carries out glucose and lactose transport in a sodium-dependent manner and that energization of anaerobic cells is required to observe transport. We also demonstrated that Thermotoga maritima carries out maltose and glucose transport using periplasmic sugar binding proteins. We began defining patterns of expression of genes encoding sugar transport and catabolic functions in both T. maritima and T. neapolitana. We began a collaborative effort to identify all the genes regulated at the transcriptional level in response to sugars substrates. These funds also allowed us to begin an examination of the functions of several periplasmic substrate binding proteins encoded in the genome of T. maritima.

  6. Were the original eubacteria thermophiles?

    NASA Technical Reports Server (NTRS)

    Achenbach-Richter, L.; Gupta, R.; Stetter, K. O.; Woese, C. R.; Johnson, P. C. (Principal Investigator)

    1987-01-01

    Thermotoga maritima is one of the more unusual eubacteria: It is highly thermophilic, growing at temperatures higher than any other eubacterium; its cell wall appears to have a unique structure and its lipids a unique composition; and the organism is surrounded by a loose-fitting sheath of unknown function. Its phenotypic uniqueness is matched by its phylogenetic position; Thermotoga maritima represents the deepest known branching in the eubacterial line of descent, as measured by ribosomal RNA sequence comparisons. T. maritima also represents the most slowly evolving of eubacterial lineages. The fact that the two deepest branchings in the eubacterial line of descent (the other, the green non-sulfur bacteria and relatives, i.e. Chloroflexus, Thermomicrobium, etc.) are both basically thermophilic and slowly evolving, strongly suggests that all eubacteria have ultimately arisen from a thermophilic ancestor.

  7. Non-target effect of organic insecticides: effect of two plant extracts on soil microbial biomass and enzymatic activities in soil.

    PubMed

    Okur, Nur; Tuna, A Levent; Okur, Bülent; Altunlu, Hakan; Kayikçioğlu, H Hüsnü; Civelek, Hasan S

    2010-06-01

    Efficacious botanical derivatives can provide an alternative to synthetic pesticides for organic farming systems. However, there is lack of information regarding the side effects of organic pesticides on key soil ecological processes. In this study, we investigated the effects of aqueous extracts from Urginea maritima and Euphorbia myrsinites exhibiting translaminar and systemic activity against pests on microbial biomass and enzymatic activities in soil. Two grams of plant material was extracted with 100 ml of water and then diluted 1:100, 2:100, and 4:100 with distilled water. Diluted plant extracts were applied around hypocotyl of tomato by soil drench. The effect of both plant extracts on microbial biomass C, amount of total N and organic C, and enzymatic activity in soil was significant. After the last application, the highest microbial biomass C was determined in the lowest U. maritima concentration (U 1:100). Soils treated with the highest concentration of U. maritima (U 4:100) had always lower SMBC content than control soil. All concentrations of E. myrsinites decreased microbial biomass C by 18% to 27% compared to the control. Total nitrogen and organic carbon decreased in soils without (control) and with treated U. maritima extract from first application to last application. Phosphatase, urease, and beta-glucosidase activities were monitored in plant extract-treated soils. Except U. maritima 1:100 treatments of second and fourth applications, the other treatments of plant extracts negatively affected enzymatic activity in soil. U. maritima and E. myrsinites plant extracts exhibited different effects on soil microbial biomass and activity, probably because of their different chemical contents. PMID:19415510

  8. Discontinuous Occurrence of the hsp70 (dnaK) Gene among Archaea and Sequence Features of HSP70 Suggest a Novel Outlook on Phylogenies Inferred from This Protein

    PubMed Central

    Gribaldo, Simonetta; Lumia, Valentina; Creti, Roberta; Conway de Macario, Everly; Sanangelantoni, Annamaria; Cammarano, Piero

    1999-01-01

    Occurrence of the hsp70 (dnaK) gene was investigated in various members of the domain Archaea comprising both euryarchaeotes and crenarchaeotes and in the hyperthermophilic bacteria Aquifex pyrophilus and Thermotoga maritima representing the deepest offshoots in phylogenetic trees of bacterial 16S rRNA sequences. The gene was not detected in 8 of 10 archaea examined but was found in A. pyrophilus and T. maritima, from which it was cloned and sequenced. Comparative analyses of the HSP70 amino acid sequences encoded in these genes, and others in the databases, showed that (i) in accordance with the vicinities seen in rRNA-based trees, the proteins from A. pyrophilus and T. maritima form a thermophilic cluster with that from the green nonsulfur bacterium Thermomicrobium roseum and are unrelated to their counterparts from gram-positive bacteria, proteobacteria/mitochondria, chlamydiae/spirochetes, deinococci, and cyanobacteria/chloroplasts; (ii) the T. maritima HSP70 clusters with the homologues from the archaea Methanobacterium thermoautotrophicum and Thermoplasma acidophilum, in contrast to the postulated unique kinship between archaea and gram-positive bacteria; and (iii) there are exceptions to the reported association between an insert in HSP70 and gram negativity, or vice versa, absence of insert and gram positivity. Notably, the HSP70 from T. maritima lacks the insert, although T. maritima is phylogenetically unrelated to the gram-positive bacteria. These results, along with the absence of hsp70 (dnaK) in various archaea and its presence in others, suggest that (i) different taxa retained either one or the other of two hsp70 (dnaK) versions (with or without insert), regardless of phylogenetic position; and (ii) archaea are aboriginally devoid of hsp70 (dnaK), and those that have it must have received it from phylogenetically diverse bacteria via lateral gene transfer events that did not involve replacement of an endogenous hsp70 (dnaK) gene. PMID:9882656

  9. Genome Sequence of Thermotoga sp Strain RQ2, a Hyperthermophilic Bacterium Isolated from a Geothermally Heated Region of the Seafloor near Ribeira Quente, the Azores

    SciTech Connect

    Swithers, Kristen S; DiPippo, Jonathan L; Bruce, David; Detter, J. Chris; Tapia, Roxanne; Han, Cliff; Woyke, Tanja; Pitluck, Sam; Pennacchio, Len; Nolan, Matt; Mikhailova, Natalia; Lykidis, A; Land, Miriam L; Stetter, Karl O; Nelson, Karen E; Gogarten, Peter; Noll, Kenneth M

    2011-01-01

    Thermotoga sp. strain RQ2 is probably a strain of Thermotoga maritima. Its complete genome sequence allows for an examination of the extent and consequences of gene flow within Thermotoga species and strains. Thermotoga sp. RQ2 differs from T. maritima in its genes involved in myo-inositol metabolism. Its genome also encodes an apparent fructose phosphotransferase system (PTS) sugar transporter. This operon is also found in Thermotoga naphthophila strain RKU-10 but no other Thermotogales. These are the first reported PTS transporters in the Thermotogales.

  10. Paternal signature in kin recognition cues of a social insect: concealed in juveniles, revealed in adults

    PubMed Central

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

    2014-01-01

    Kin recognition is a key mechanism to direct social behaviours towards related individuals or avoid inbreeding depression. In insects, recognition is generally mediated by cuticular hydrocarbon (CHC) compounds, which are partly inherited from parents. However, in social insects, potential nepotistic conflicts between group members from different patrilines are predicted to select against the expression of patriline-specific signatures in CHC profiles. Whereas this key prediction in the evolution of insect signalling received empirical support in eusocial insects, it remains unclear whether it can be generalized beyond eusociality to less-derived forms of social life. Here, we addressed this issue by manipulating the number of fathers siring clutches tended by females of the European earwig, Forficula auricularia, analysing the CHC profiles of the resulting juvenile and adult offspring, and using discriminant analysis to estimate the information content of CHC with respect to the maternal and paternal origin of individuals. As predicted, if paternally inherited cues are concealed during family life, increases in mating number had no effect on information content of CHC profiles among earwig juveniles, but significantly decreased the one among adult offspring. We suggest that age-dependent expression of patriline-specific cues evolved to limit the risks of nepotism as family-living juveniles and favour sibling-mating avoidance as group-living adults. These results highlight the role of parental care and social life in the evolution of chemical communication and recognition cues. PMID:25165768

  11. 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.

  12. Paternal signature in kin recognition cues of a social insect: concealed in juveniles, revealed in adults.

    PubMed

    Wong, Janine W Y; Meunier, Joël; Lucas, Christophe; Kölliker, Mathias

    2014-10-22

    Kin recognition is a key mechanism to direct social behaviours towards related individuals or avoid inbreeding depression. In insects, recognition is generally mediated by cuticular hydrocarbon (CHC) compounds, which are partly inherited from parents. However, in social insects, potential nepotistic conflicts between group members from different patrilines are predicted to select against the expression of patriline-specific signatures in CHC profiles. Whereas this key prediction in the evolution of insect signalling received empirical support in eusocial insects, it remains unclear whether it can be generalized beyond eusociality to less-derived forms of social life. Here, we addressed this issue by manipulating the number of fathers siring clutches tended by females of the European earwig, Forficula auricularia, analysing the CHC profiles of the resulting juvenile and adult offspring, and using discriminant analysis to estimate the information content of CHC with respect to the maternal and paternal origin of individuals. As predicted, if paternally inherited cues are concealed during family life, increases in mating number had no effect on information content of CHC profiles among earwig juveniles, but significantly decreased the one among adult offspring. We suggest that age-dependent expression of patriline-specific cues evolved to limit the risks of nepotism as family-living juveniles and favour sibling-mating avoidance as group-living adults. These results highlight the role of parental care and social life in the evolution of chemical communication and recognition cues.

  13. Genome evolution: groping in the soil interstices.

    PubMed

    Minelli, Alessandro

    2015-03-01

    Centipedes are a very old lineage of terrestrial animals. The first completely sequenced myriapod genome reveals that the blind centipede Strigamia maritima has no gene for light-sensory proteins, lacks the canonical circadian clock and possesses unusual features related to chemosensory perception. PMID:25734267

  14. Beet curly top resistance of USDA-ARS National Plant Germplasm System plant introductions, 2009

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty 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) in 2009. The curly top evaluation was conducted at the USDA-ARS North Farm in Kimberly...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. Release of EL54 Sugarbeet Germplasm Derived from WB879 Wild Germplasm With Resistance to Aphanomyces and Excellent Stand Establishment

    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). EL54 is being released in the interest of broadening the genetic base of sugar beet. The parent accession WB879, collected in 1989 from Port-de-Houet, France (3 m elevation), w...

  20. Rhizoctonia crown and root rot resistance evaluation of Beta PIs in Fort Collins, CO, 2015

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty beet accessions of either cultivated beet or sea beet (Beta vulgaris subsp. vulgaris or Beta vulgaris subsp. maritima (L.) Arcang) from the Beta collection of the USDA-Agricultural Research Service National Plant Germplasm System were screened for resistance to Rhizoctonia crown and root rot ...

  1. Gene Transfer & Hybridization Studies in Hyperthermophilic Species

    SciTech Connect

    Nelson, Karen E.

    2005-10-14

    A. ABSTRACT The importance of lateral gene transfer (LGT) in the evolution of microbial species has become increasingly evident with each completed microbial genome sequence. Most significantly, the genome of Thermotoga maritima MSB8, a hyperthermophilic bacterium isolated by Karl Stetter and workers from Vulcano Italy in 1986, and sequenced at The Institute for Genomic Research (TIGR) in Rockville Maryland in 1999, revealed extensive LGT between % . this bacterium and members of the archaeal domain (in particular Archaeoglobus fulgidus, and Pyracoccus frcriosus species). Based on whole genome comparisons, it was estimated that 24% of the genetic information in this organism was acquired by genetic exchange with archaeal species, Independent analyses including periodicity analysis of the T. maritimu genomic DNA sequence, phylogenetic reconstruction based on genes that appear archaeal-like, and codon and amino acid usage, have provided additional evidence for LGT between T. maritima and the archaea. More recently, DiRuggiero and workers have identified a very recent LGT event between two genera of hyperthermophilic archaea, where a nearly identical DNA fragment of 16 kb in length flanked by insertion sequence (IS) elements, exists. Undoubtedly, additional examples of LGT will be identified as more microbial genomes are completed. For the present moment however, the genome sequence of T. maritima and other hyperthermophiles including P. furiosus, Pyrococcus horikoshii, Pyrococcus abyssi, A. fulgidus, and Aquifex aeolicus, have significantly increased out awareness of evolution being a web of life rather than a tree of life, as suggested by single gene phylogenies. In this proposal, we will aim to determine the extent of LGT across the hyperthemophiles, employing iY maritima as the model organism. A variety of biochemical techniques and phylogenetic reconstructions will allow for a detailed and thorough characterization of the extent of LGT in this species. The

  2. A tale of two spartinas: Climatic, photobiological and isotopic insights on the fitness of non-indigenous versus native species

    NASA Astrophysics Data System (ADS)

    Duarte, B.; Baeta, A.; Rousseau-Gueutin, M.; Ainouche, M.; Marques, J. C.; Caçador, I.

    2015-12-01

    Salt marshes are facing a new threat: the invasion by non-indigenous species (NIS), Although its introduction time is not established yet, in 1999 Spartina versicolor was already identified as a NIS in the Mediterranean marshes, significantly spreading its area of colonization. Using the Mediterranean native Spartina maritima as a reference, the present research studied the ecophysiological fitness of this NIS in its new environment, as a tool to understand its potential invasiveness. It was found that Spartina versicolor had a stable photobiological pattern, with only minor fluctuations during an annual cycle, and lower efficiencies comparated to S. maritima. The NIS seems to be rather insensitive to the observed abiotic factors fluctuations (salinity and pH of the sediment), and thus contrasts with the native S. maritima, known to be salinity dependent with higher productivity values in higher salinity environments. Most of the differences observed between the photobiology of these species could be explained by their nitrogen nutrition (here evaluated by the δ15N stable isotope) and directly related with the Mediterranean climate. Enhanced by a higher N availability during winter, the primary production of S. maritima which lead to dilution of the foliar δ15N concentration in the newly formed biomass, similarly to what is observed along a rainfall gradient. On the other hand, S. versicolor showed an increased δ15N in its tissues along the annual rainfall gradient, probably due to a δ15N concentration effect during low biomass production periods (winter and autumn). Together with the photobiological traits, these isotopic data point out to a climatic misfit of S. versicolor to the Mediterranean climate compared to the native S. maritima. This appears to be the major constrain shaping the ecophysiological fitness of this NIS, its primary production and consequently, its spreading rate along the Mediterranean marshes.

  3. Response of primary producers to nutrient enrichment in a shallow estuary

    USGS Publications Warehouse

    Kinney, E.H.; Roman, C.T.

    1998-01-01

    Shallow coastal systems worldwide are exhibiting increased algal growth in response to nutrient enrichment. This study evaluates primary production patterns in an estuarine system (Bass Harbor Marsh, ME, USA) receiving low levels of anthropogenic nitrogen. Biomass, areal coverage and in situ oxygen production of green macroalgae, Ruppia Maritima, and Phytoplankton were measured over a growing season to determine net ecosystem production. Macroalgae and R. maritima exhibited seasonal biomass curves with early summer peaks; however, peak biomass of macroalgae [150 g dry weight (wt) m-2] was substantially greater that R. maritima (33 g dry wt m-2) Phytoplankton biomass, measured as chlorophyll a, was low (<1 ??g 1-1) early in the season and peaked (11 ??g 1-1) following a mid-summer decline in macroalgal biomass, suggesting a competitive interaction with macroalgae. Instantaneous net production rates varied over the growing season for all 3 primary producers. R. maritima net production ranged from near zero to 2.7 mg C g-1 dry wt h-1, with higher rates during summer and much of the seasonal variability explained by temperature. Macroalgal (0.88 to 5.0 mg C g-1 dry wt h-1) and phytoplankton (0 to 28 mg C m-3 h-1) net production did not exhibit any clear seasonal signal. Net primary production calculated on an areal basis demonstrated macroalgae's dominance in the lower basin of Bass Harbor Marsh, with peak summer rates (400 mg C m-2 h-1) greatly exceeding maximum rates for both R maritima (70 mg C m-2h-1) and phytoplankton (12 mg C m-2 h-1). When compared to other New England estuarine sites with short residence times, nutrient loading and peak green macroalgal biomass in Bass Harbor Marsh are relatively low; however, the strong dominance of opportunistic green macroalgae is a pattern that is characteristic of shallow coastal systems undergoing eutrophication.

  4. Cryptic seedling herbivory by nocturnal introduced generalists impacts survival, performance of native and exotic plants.

    PubMed

    Strauss, Sharon Y; Stanton, Maureen L; Emery, Nancy C; Bradley, Carrie A; Carleton, Alexandra; Dittrich-Reed, Dylan R; Ervin, Olivia A; Gray, Levi N; Hamilton, Andrew M; Rogge, Jennifer Harrington; Harper, Skye D; Law, Kimberley Cook; Pham, Vinh Q; Putnam, Matthew E; Roth, Tara M; Theil, Jacob H; Wells, Lara M; Yoshizuka, Eric M

    2009-02-01

    Although much of the theory on the success of invasive species has been geared at escape from specialist enemies, the impact of introduced generalist invertebrate herbivores on both native and introduced plant species has been underappreciated. The role of nocturnal invertebrate herbivores in structuring plant communities has been examined extensively in Europe, but less so in North America. Many nocturnal generalists (slugs, snails, and earwigs) have been introduced to North America, and 96% of herbivores found during a night census at our California Central Valley site were introduced generalists. We explored the role of these herbivores in the distribution, survivorship, and growth of 12 native and introduced plant species from six families. We predicted that introduced species sharing an evolutionary history with these generalists might be less vulnerable than native plant species. We quantified plant and herbivore abundances within our heterogeneous site and also established herbivore removal experiments in 160 plots spanning the gamut of microhabitats. As 18 collaborators, we checked 2000 seedling sites every day for three weeks to assess nocturnal seedling predation. Laboratory feeding trials allowed us to quantify the palatability of plant species to the two dominant nocturnal herbivores at the site (slugs and earwigs) and allowed us to account for herbivore microhabitat preferences when analyzing attack rates on seedlings. The relationship between local slug abundance and percent cover of five common plant taxa at the field site was significantly negatively associated with the mean palatability of these taxa to slugs in laboratory trials. Moreover, seedling mortality of 12 species in open-field plots was positively correlated with mean palatability of these taxa to both slugs and earwigs in laboratory trials. Counter to expectations, seedlings of native species were neither more vulnerable nor more palatable to nocturnal generalists than those of

  5. Acoustic detection of Oryctes rhinoceros (Coleoptera: Scarabaeidae: Dynastinae) and Nasutitermes luzonicus (Isoptera: Termitidae) in palm trees in urban Guam.

    PubMed

    Mankin, R W; Moore, A

    2010-08-01

    Adult and larval Oryctes rhinoceros (L.) (Coleoptera: Scarabaeidae: Dynastinae) were acoustically detected in live and dead palm trees and logs in recently invaded areas of Guam, along with Nasutitermes luzonicus Oshima (Isoptera: Termitidae), and other small, sound-producing invertebrates and invertebrates. The low-frequency, long-duration sound-impulse trains produced by large, active O. rhinoceros and the higher frequency, shorter impulse trains produced by feeding N. luzonicus had distinctive spectral and temporal patterns that facilitated their identification and discrimination from background noise, as well as from roaches, earwigs, and other small sound-producing organisms present in the trees and logs. The distinctiveness of the O. rhinoceros sounds enables current usage of acoustic detection as a tactic in Guam's ongoing O. rhinoceros eradication program.

  6. 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

  7. Effect of habitat quality on diet flexibility in Barbary macaques.

    PubMed

    Ménard, Nelly; Motsch, Peggy; Delahaye, Alexia; Saintvanne, Alice; Le Flohic, Guillaume; Dupé, Sandrine; Vallet, Dominique; Qarro, Mohamed; Tattou, Mohamed Ibn; Pierre, Jean-Sébastien

    2014-07-01

    Barbary macaques live in extreme temperate environments characterized by strongly seasonal resource availability. They are mainly terrestrial while foraging, harvesting food from the herbaceous layer. These monkeys are threatened mainly because of anthropogenic habitat degradation. We studied the adaptive capacities of wild groups of Barbary macaques that lived in different cedar forests undergoing varying extents of grazing pressure from domestic livestock. In all three sites, diet varied seasonally. Heavy grazing led to a significant decrease in herbaceous production and species richness. As a consequence, the monkeys' diet in this poor habitat showed a decreased plant species richness. Moreover, it incorporated fewer above-ground herbaceous resources, and a greater proportion of subterranean resources (especially hypogeous fungi and subterranean invertebrates such as earthworms, eggs and adults of earwigs, and ant's larvae) than the diet of monkeys inhabiting ungrazed forest. Cedar bark, cedar strobiles, earthworms, and earwigs were part of the monkeys' diet only in grazed forest. Monkeys in heavily grazed forest compensated for a lack of herbaceous foods by eating subterranean foods preferentially to tree and shrub products. The foods they consumed take longer to harvest and process than the seeds or leaves consumed by Barbary macaques in less heavily grazed forest habitats. Our results suggest that monkeys do differ in their diets according to the degree of habitat change induced by human activities. They also highlight the dietary flexibility of Barbary macaques as a key element that allows them to cope with degraded habitats. We later compare the dietary adjustments of Barbary macaques facing environmental change to dietary strategies of other macaques and temperate-zone primates.

  8. Effect of habitat quality on diet flexibility in Barbary macaques.

    PubMed

    Ménard, Nelly; Motsch, Peggy; Delahaye, Alexia; Saintvanne, Alice; Le Flohic, Guillaume; Dupé, Sandrine; Vallet, Dominique; Qarro, Mohamed; Tattou, Mohamed Ibn; Pierre, Jean-Sébastien

    2014-07-01

    Barbary macaques live in extreme temperate environments characterized by strongly seasonal resource availability. They are mainly terrestrial while foraging, harvesting food from the herbaceous layer. These monkeys are threatened mainly because of anthropogenic habitat degradation. We studied the adaptive capacities of wild groups of Barbary macaques that lived in different cedar forests undergoing varying extents of grazing pressure from domestic livestock. In all three sites, diet varied seasonally. Heavy grazing led to a significant decrease in herbaceous production and species richness. As a consequence, the monkeys' diet in this poor habitat showed a decreased plant species richness. Moreover, it incorporated fewer above-ground herbaceous resources, and a greater proportion of subterranean resources (especially hypogeous fungi and subterranean invertebrates such as earthworms, eggs and adults of earwigs, and ant's larvae) than the diet of monkeys inhabiting ungrazed forest. Cedar bark, cedar strobiles, earthworms, and earwigs were part of the monkeys' diet only in grazed forest. Monkeys in heavily grazed forest compensated for a lack of herbaceous foods by eating subterranean foods preferentially to tree and shrub products. The foods they consumed take longer to harvest and process than the seeds or leaves consumed by Barbary macaques in less heavily grazed forest habitats. Our results suggest that monkeys do differ in their diets according to the degree of habitat change induced by human activities. They also highlight the dietary flexibility of Barbary macaques as a key element that allows them to cope with degraded habitats. We later compare the dietary adjustments of Barbary macaques facing environmental change to dietary strategies of other macaques and temperate-zone primates. PMID:24573596

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

    PubMed Central

    Joshi, Yogesh; Wang, Xin Yu; Lökös, László; Koh, Young Jin

    2010-01-01

    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

  10. 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.

  11. [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

  12. Large methyl halide emissions from south Texas salt marshes

    NASA Astrophysics Data System (ADS)

    Rhew, R. C.; Whelan, M. E.; Min, D.-H.

    2014-06-01

    Coastal salt marshes are natural sources of methyl chloride (CH3Cl) and methyl bromide (CH3Br) to the atmosphere, but measured emission rates vary widely by geography. Here we report large methyl halide fluxes from subtropical salt marshes of south Texas. Sites with the halophytic plant, Batis maritima, emitted methyl halides at rates that are orders of magnitude greater than sites containing other vascular plants or macroalgae. B. maritima emissions were generally highest at midday; however, diurnal variability was more pronounced for CH3Br than CH3Cl, and surprisingly high nighttime CH3Cl fluxes were observed in July. Seasonal and intra-site variability were large, even taking into account biomass differences. Overall, these subtropical salt marsh sites show much higher emission rates than temperate salt marshes at similar times of the year, supporting the contention that low-latitude salt marshes are significant sources of CH3Cl and CH3Br.

  13. Large methyl halide emissions from south Texas salt marshes

    NASA Astrophysics Data System (ADS)

    Rhew, R. C.; Whelan, M. E.; Min, D.-H.

    2014-11-01

    Coastal salt marshes are natural sources of methyl chloride (CH3Cl) and methyl bromide (CH3Br) to the atmosphere, but measured emission rates vary widely by geography. Here we report large methyl halide fluxes from subtropical salt marshes of south Texas. Sites with the halophytic plant, Batis maritima, emitted methyl halides at rates that are orders of magnitude greater than sites containing other vascular plants or macroalgae. B. maritima emissions were generally highest at midday; however, diurnal variability was more pronounced for CH3Br than CH3Cl, and surprisingly high nighttime CH3Cl fluxes were observed in July. Seasonal and intra-site variability were large, even taking into account biomass differences. Overall, these subtropical salt marsh sites show much higher emission rates than temperate salt marshes at similar times of the year, supporting the contention that low-latitude salt marshes are significant sources of CH3Cl and CH3Br.

  14. Determination of substrate specificities against β-glucosidase A (BglA) from Thermotoga maritime: a molecular docking approach.

    PubMed

    Rajoka, Muhammad Ibrahim; Idrees, Sobia; Ashfaq, Usman Ali; Ehsan, Beenish; Haq, Asma

    2015-01-01

    Thermostable enzymes derived from Thermotoga maritima have attracted worldwide interest for their potential industrial applications. Structural analysis and docking studies were preformed on T. maritima β-glucosidase enzyme with cellobiose and pNP-linked substrates. The 3D structure of the thermostable β-glucosidase was downloaded from the Protein Data Bank database. Substrates were downloaded from the PubCehm database and were minimized using MOE software. Docking of BglA and substrates was carried out using MOE software. After analyzing docked enzyme/substrate complexes, it was found that Glu residues were mainly involved in the reaction, and other important residues such as Asn, Ser, Tyr, Trp, and His were involved in hydrogen bonding with pNP-linked substrates. By determining the substrate recognition pattern, a more suitable β-glucosidase enzyme could be developed, enhancing its industrial potential.

  15. 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.

  16. 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

  17. Synthesis of new N-analogous corollosporine derivatives with antibacterial activity by laccase-catalyzed amination.

    PubMed

    Mikolasch, Annett; Hessel, Susanne; Salazar, Manuela Gesell; Neumann, Helfried; Manda, Katrin; Gōrdes, Dirk; Schmidt, Enrico; Thurow, Kerstin; Hammer, Elke; Lindequist, Ulrike; Beller, Matthias; Schauer, Frieder

    2008-06-01

    Corollosporine isolated from the marine fungus Corollospora maritima and N-analogous corollosporines are antimicrobial substances. Owing to the basic structure of the N-analogous corollosporines, they have become an attractive target for laccase-catalyzed derivatisation. In this regard we report on the straightforward laccase-catalyzed amination of dihydroxylated arenes with N-analogous corollosporines. In biological assays the obtained amination products are more active than the parent compounds.

  18. Thermostable cellulases, and mutants thereof, capable of hydrolyzing cellulose in ionic liquid

    DOEpatents

    Sapra, Rajat; Datta, Supratim; Chen, Zhiwei; Holmes, Bradley M.; Simmons, Blake A.; Blanch, Harvey W.

    2016-04-26

    The present invention provides for a composition comprising an ionic liquid and a thermostable cellulose, and a method of hydrolyzing a cellulose, comprising: (a) providing a composition comprising a solution comprising an ionic liquid and a cellulose, and (b) introducing a thermostable cellulase to the solution, such that the cellulose is hydrolyzed by the cellulase. The present invention also provides for a Thermatoga maritima thermostable cellulase mutant with increased cellulase activity.

  19. Activity of select dehydrogenases with Sepharose-immobilized N6-carboxymethyl-NAD

    PubMed Central

    Beauchamp, Justin; Vieille, Claire

    2015-01-01

    N6-carboxymethyl-NAD (N6-CM-NAD) can be used to immobilize NAD onto a substrate containing terminal primary amines. We previously immobilized N6-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 N6-CM-NAD. The products of all enzymes but 6-phospho-D-glucono-1,5-lactone were formed when sepharose-immobilized N6-CM-NAD was recycled by T. maritima glycerol dehydrogenase, indicating that N6-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 N6-amine group on NAD. PMID:25611453

  20. New approaches to understanding double-stranded RNA processing by ribonuclease III purification and assays of homodimeric and heterodimeric forms of RNase III from bacterial extremophiles and mesophiles.

    PubMed

    Meng, Wenzhao; Nicholson, Rhonda H; Nathania, Lilian; Pertzev, Alexandre V; Nicholson, Allen W

    2008-01-01

    Ribonuclease III (RNase III) is a double-stranded (ds)-RNA-specific endonuclease that plays essential roles in the maturation and decay of coding and noncoding RNAs. Bacterial RNases III are structurally the simplest members of the RNase III family, which includes the eukaryotic orthologs Dicer and Drosha. High-resolution crystal structures of RNase III of the hyperthermophilic bacteria Aquifex aeolicus and Thermotoga maritima are available. A. aeolicus RNase III also has been cocrystallized with dsRNA or specific hairpin substrates. These structures have provided essential structural insight to the mechanism of dsRNA recognition and cleavage. However, comparatively little is known about the catalytic behaviors of A. aeolicus or T. maritima RNases III. This chapter provides protocols for the purification of A. aeolicus and T. maritima RNases III and also describes the preparation of artificial heterodimers of Escherichia coli RNase III, which are providing new insight on the subunit and domain interactions involved in dsRNA recognition and cleavage.

  1. Selection of a halophytic plant for assessing the phytotoxicity of dredged seaport sediment stored on land.

    PubMed

    Bedell, J-P; Ferro, Y; Bazin, C; Perrodin, Y

    2014-01-01

    The filling of dry quarries in coastal areas with sediments dredged in seaports represents a potentially interesting method of recycling of these materials. However, this recycling requires the prior carrying out of an Environmental Risk Assessment of the scenario concerned. For this, the question arose as to the type of plants capable of developing on the surface of such a deposit and the method to implement for assessing the possible phytotoxicity of dredged sediments. To answer this question, we chose to work with halophytic plants to be free from the salt-related effect and to assess only the effect related to the toxic compounds present. Based on the objectives set, these works led to the use of common plants of the French coast, with direct seeding, and with pollution-sensitive plants. Three species of angiosperms, Armeria maritima, Anthemis maritima and Plantago coronopus, were finally tested. As a result of this work, Armeria maritima was retained as the most suitable plant for testing the possible phytotoxic effect of dredged marine sediments stored on land. The results obtained with this plant are as follows: germination of 40 % of the seeds in 31 days, produced biomass of 493 mg FW in 6 months and a capacity to bioaccumulate metal pollutants in roots with 350 and 720 mg/kg DW for Zn and Cu, respectively. PMID:23955497

  2. Hidden diversity in wild Beta taxa from Portugal: insights from genome size and ploidy level estimations using flow cytometry.

    PubMed

    Castro, Sílvia; Romeiras, Maria M; Castro, Mariana; Duarte, Maria Cristina; Loureiro, João

    2013-06-01

    Crop wild relatives constitute a broad pool of potentially useful genetic resources for plant breeders. The genus Beta L. (Amaranthaceae) is an important source of crops, primarily for sugar production. Until recently, species within Section Beta were mostly cytogenetically uniform, with diploidy being prevalent. Still, with the discovery of tetraploid individuals of the wild B. macrocarpa in the Canary Islands, a large-scale study was necessary to evaluate the cytogenetic diversity within the wild Beta. For that, genome size and ploidy level of B. vulgaris subsp. maritima and B. macrocarpa from 21 populations across Portugal mainland and islands, including all know populations of the later taxon, were estimated using propidium iodide flow cytometry. This work revealed a cytogenetically diverse scenario. The analyzed populations were mostly diploid, except for one population of B. vulgaris subsp. maritima that presented both diploid and tetraploid individuals, and for two populations of B. macrocarpa where two or three cytotypes (diploids, tetraploids and/or hexaploids) were found. The nuclear DNA content of diploid individuals was estimated as 1.44±0.035 and 1.41±0.027 pg/2C for B. vulgaris subsp. maritima and B. macrocarpa, respectively. Also, leaves of both species presented variable levels of endopolyploidy. The obtained results are discussed within the context of interspecific hybridization and cryptic diversity and constitute significant data for the conservation of these wild Beta crop relatives. PMID:23602101

  3. Activity of select dehydrogenases with sepharose-immobilized N(6)-carboxymethyl-NAD.

    PubMed

    Beauchamp, Justin; Vieille, Claire

    2015-01-01

    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.

  4. Hidden diversity in wild Beta taxa from Portugal: insights from genome size and ploidy level estimations using flow cytometry.

    PubMed

    Castro, Sílvia; Romeiras, Maria M; Castro, Mariana; Duarte, Maria Cristina; Loureiro, João

    2013-06-01

    Crop wild relatives constitute a broad pool of potentially useful genetic resources for plant breeders. The genus Beta L. (Amaranthaceae) is an important source of crops, primarily for sugar production. Until recently, species within Section Beta were mostly cytogenetically uniform, with diploidy being prevalent. Still, with the discovery of tetraploid individuals of the wild B. macrocarpa in the Canary Islands, a large-scale study was necessary to evaluate the cytogenetic diversity within the wild Beta. For that, genome size and ploidy level of B. vulgaris subsp. maritima and B. macrocarpa from 21 populations across Portugal mainland and islands, including all know populations of the later taxon, were estimated using propidium iodide flow cytometry. This work revealed a cytogenetically diverse scenario. The analyzed populations were mostly diploid, except for one population of B. vulgaris subsp. maritima that presented both diploid and tetraploid individuals, and for two populations of B. macrocarpa where two or three cytotypes (diploids, tetraploids and/or hexaploids) were found. The nuclear DNA content of diploid individuals was estimated as 1.44±0.035 and 1.41±0.027 pg/2C for B. vulgaris subsp. maritima and B. macrocarpa, respectively. Also, leaves of both species presented variable levels of endopolyploidy. The obtained results are discussed within the context of interspecific hybridization and cryptic diversity and constitute significant data for the conservation of these wild Beta crop relatives.

  5. Evolution of mal ABC transporter operons in the Thermococcales and Thermotogales

    PubMed Central

    2008-01-01

    Background The mal genes that encode maltose transporters have undergone extensive lateral transfer among ancestors of the archaea Thermococcus litoralis and Pyrococcus furiosus. Bacterial hyperthermophiles of the order Thermotogales live among these archaea and so may have shared in these transfers. The genome sequence of Thermotoga maritima bears evidence of extensive acquisition of archaeal genes, so its ancestors clearly had the capacity to do so. We examined deep phylogenetic relationships among the mal genes of these hyperthermophiles and their close relatives to look for evidence of shared ancestry. Results We demonstrate that the two maltose ATP binding cassette (ABC) transporter operons now found in Tc. litoralis and P. furiosus (termed mal and mdx genes, respectively) are not closely related to one another. The Tc. litoralis and P. furiosus mal genes are most closely related to bacterial mal genes while their respective mdx genes are archaeal. The genes of the two mal operons in Tt. maritima are not related to genes in either of these archaeal operons. They are highly similar to one another and belong to a phylogenetic lineage that includes mal genes from the enteric bacteria. A unique domain of the enteric MalF membrane spanning proteins found also in these Thermotogales MalF homologs supports their relatively close relationship with these enteric proteins. Analyses of genome sequence data from other Thermotogales species, Fervidobacterium nodosum, Thermosipho melanesiensis, Thermotoga petrophila, Thermotoga lettingae, and Thermotoga neapolitana, revealed a third apparent mal operon, absent from the published genome sequence of Tt. maritima strain MSB8. This third operon, mal3, is more closely related to the Thermococcales' bacteria-derived mal genes than are mal1 and mal2. F. nodosum, Ts. melanesiensis, and Tt. lettingae have only one of the mal1-mal2 paralogs. The mal2 operon from an unknown species of Thermotoga appears to have been horizontally

  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 Ompα) and the porin OmpB (previously termed Ompβ). 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 OmpB had β-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. Effects of migratory geese on plant communities of an Alaskan salt marsh

    USGS Publications Warehouse

    Zacheis, A.; Hupp, J.W.; Ruess, R.W.

    2001-01-01

    1. We studied the effects of lesser snow geese (Anser caerulescens caerulescens) and Canada geese (Branta canadensis) on two salt marsh plant communities in Cook Inlet, Alaska, a stopover area used during spring migration. From 1995 to 1997 we compared plant species composition and biomass on plots where geese were excluded from feeding with paired plots where foraging could occur. 2. Foraging intensity was low (650-1930 goose-days km-2) compared to other goose-grazing systems. 3. Canada geese fed mainly on above-ground shoots of Triglochin maritimum, Puccinellia spp. and Carex ramenskii, whereas the majority of the snow goose diet consisted of below-ground tissues of Plantago maritima and Triglochin maritimum. 4. Plant communities responded differently to goose herbivory. In the sedge meadow community, where feeding was primarily on above-ground shoots, there was no effect of grazing on the dominant species Carex ramenskii and Triglochin maritimum. In the herb meadow community, where snow geese fed on Plantago maritima roots and other below-ground tissues, there was a difference in the relative abundance of plant species between treatments. Biomass of Plantago maritima and Potentilla egedii was lower on grazed plots compared with exclosed, whereas biomass of Carex ramenskii was greater on grazed plots. There was no effect of herbivory on total standing crop biomass in either community. The variable effect of herbivory on Carex ramenskii between communities suggests that plant neighbours and competitive interactions are important factors in a species' response to herbivory. In addition, the type of herbivory (above- or below-ground) was important in determining plant community response to herbivory. 5. Litter accumulation was reduced in grazed areas compared with exclosed in both communities. Trampling of the previous year's litter into the soil surface by geese incorporated more litter into soils in grazed areas. 6. This study illustrates that even light herbivore

  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. Valve, compressor contracts awarded for Western Hemisphere projects

    SciTech Connect

    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.

  10. Antioxidant activity of wild plants collected in Beni-Sueif governorate, Upper Egypt.

    PubMed

    Abouzid, S; Elshahaat, A; Ali, S; Choudhary, M I

    2008-10-01

    Antioxidant activity of a selection of commonly occurring wild plants growing in Beni-Sueif governorate, Upper Egypt, has been tested. The plants selected are Tamarix nilotica, Ambrosia maritima, Zygophyllum coccenium, Conyza dioscoridis, Chenopodium ambrosioides, and Calotropis procera. The in vitro antioxidant assays used in this study were 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity, superoxide anion scavenging activity and iron chelating activity. Extracts prepared from the leaves and flowers of Tamarix nilotica have shown the highest antioxidant activity in the three kinds of assay.

  11. Opening a can of centipedes: new insights into mechanisms of body segmentation.

    PubMed

    Valentin, Guillaume; Oates, Andrew C

    2013-01-01

    The search for a common developmental genetic mechanism of body segmentation appears to become more difficult, and more interesting, as new segmented organisms are added to the roster. Recent work in this journal by Brena and Akam on segmentation of the geophilomorph centipede Strigamia maritima, an arthropod distantly related to the standard insect models, contains developmental and evolutionary surprises that highlight the importance of a wider sampling of phyla.See research article: http://www.biomedcentral.com/1741-7007/11/112. PMID:24289333

  12. Remote sensing of biomass of salt marsh vegetation in France

    NASA Technical Reports Server (NTRS)

    Gross, M. F.; Klemas, V.; Levasseur, J. E.

    1988-01-01

    Spectral data (gathered using a hand-held radiometer) and harvest data were collected from four salt marsh vegetation types in Brittany, France, to develop equations predicting live aerial biomass from spectral measurements. Remote sensing estimates of biomass of the general salt marsh community (GSM) and of Spartina alterniflora can be obtained throughout the growing season if separate biomass prediction equations are formulated for different species mixtures (for the GSM) and for different canopy types (for S. alterniflora). Results suggest that remote sensing will not be useful for predicting Halimione portulacoides biomass, but can be used to estimate Puccinellia maritima biomass early in the growing season.

  13. Induced Changes in the Amino Acid Profile of Biomphalaria alexandrina Molluscan Host to Schistosoma mansoni Using Sublethal Concentrations of Selected Plant Molluscicides

    NASA Astrophysics Data System (ADS)

    Sanad Soliman, Mahmoud; El-Ansary, Afaf

    Amino acid profiles of control and Solanum nigrum, Ambrosia maritima, Thymelaea hirsute, Sinapis arvensis, Peganum haramala and Callistemon lanceolatus-treated Biomphalaria alexandrina snails were investigated in a trial to correlate the amino acid profile of treated snails to their previously reported molluscicidal and biological effects. Amino acid profiles of the snails were greatly manipulated with the treatment of dry powdered sublethal concentrations of the six studied plant molluscicides. The disturbed amino acid profiles of treated snails were discussed in relation to the decrease in snail's egg laying capacity, reduction of their compatibility for the development of the schistosome larvae and cercarial penetration of mammalian skin.

  14. Patterns of threshold evolution in polyphenic insects under different developmental models.

    PubMed

    Tomkins, Joseph L; Moczek, Armin P

    2009-02-01

    Two hypotheses address the evolution of polyphenic traits in insects. Under the developmental reprogramming model, individuals exceeding a threshold follow a different developmental pathway from individuals below the threshold. This decoupling is thought to free selection to independently hone alternative morphologies, increasing phenotypic plasticity and morphological diversity. Under the alternative model, extreme positive allometry explains the existence of alternative phenotypes and divergent phenotypes are developmentally coupled by a continuous reaction norm, such that selection on either morph acts on both. We test the hypothesis that continuous reaction norm polyphenisms, evolve through changes in the allometric parameters of even the smallest males with minimal trait expression, whereas threshold polyphenisms evolve independent of the allometric parameters of individuals below the threshold. We compare two polyphenic species; the dung beetle Onthophagus taurus, whose allometry has been modeled both as a threshold polyphenism and a continuous reaction norm and the earwig Forficula auricularia, whose allometry is best modeled with a discontinuous threshold. We find that across populations of both species, variation in forceps or horn allometry in minor males are correlated to the population's threshold. These findings suggest that regardless of developmental mode, alternative morphs do not evolve independently of one another.

  15. The population determines whether and how life-history traits vary between reproductive events in an insect with maternal care.

    PubMed

    Ratz, Tom; Kramer, Jos; Veuille, Michel; Meunier, Joël

    2016-10-01

    The last reproductive event of a female is often associated with major changes in terms of both maternal and offspring life-history traits. However, the nature of these changes and the importance of population-specific environmental constraints in shaping their expression are difficult to predict and, as a consequence, poorly understood. Here, we investigated whether and how life-history traits vary between reproductive events and whether this variation is population-dependent in the European earwig Forficula auricularia. In this insect species, females produce up to two clutches during their lifetime and express extensive forms of maternal care. We conducted a common garden experiment, in which we measured 11 life-history traits of the first and second clutches of 132 females originating from three populations. Our results showed that clutch size was higher and the level of care expressed towards juveniles lower in second as compared to the first clutches in all three populations. In contrast, we found a population-specific effect on whether and how the reproductive event shaped juvenile quality and a trade-off between egg developmental time and female weight at hatching. Overall, these findings emphasise that the last reproductive event of a female entails both positive and negative effects on various life-history traits of the female herself and her clutch of juveniles. Moreover, our study stresses the importance of population idiosyncrasies on the expression and nature of such cohort-specific effects.

  16. Differential ant exclusion from canopies shows contrasting top-down effects on community structure.

    PubMed

    Mestre, Laia; Piñol, J; Barrientos, J A; Espadaler, X

    2016-01-01

    Predators have far-reaching effects on communities by triggering top-down trophic cascades that influence ecosystem functioning. Omnivory and intraguild interactions between predators give rise to reticulate food webs and may either strengthen or dampen trophic cascades depending on context. Disentangling the effects of multiple predator species is therefore crucial for predicting the influence of predators on community structure. We focused on ants as dominant generalist predators in arthropod communities and set up a differential ant exclusion from canopies to examine its effects on assemblage species composition and densities of five arthropod groups (psocopterans, aphids, spiders, heteropterans and beetles). We coupled a glue band with tubes allowing only the ant Lasius grandis to reach the canopies to isolate its effect from the rest of crawling predators (ants, earwigs) and compared it against a full exclusion and a control. L. grandis alone had widespread effects on assemblage species composition, with contrasting species-specific responses within groups, where some species affected by L. grandis presence were not further affected by the presence of the whole crawling predator assemblage, and vice versa. Overall, L. grandis caused two- to threefold decreases of generalist predators and a threefold increase of aphids. However, it lacked further top-down effects on primary consumers, which only emerged when all crawling predators were present. This differential exclusion demonstrates the distinctive and widespread intraguild effects on community structure of a single ant species that contrast with the top-down effects exerted by the whole crawling predator assemblage.

  17. Fauna Europaea – Orthopteroid orders

    PubMed Central

    Bohn, Horst; Haas, Fabian; Willemse, Fer

    2016-01-01

    Abstract Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant European terrestrial and freshwater animals, their geographical distribution at the level of countries and major islands (west of the Urals and excluding the Caucasus region), and some additional information. The Fauna Europaea project comprises about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. Fauna Europaea represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. The “Orthopteroid orders“ is one of the 58 Fauna Europaea major taxonomic groups. It contains series of mostly well-known insect orders: Embiodea (webspinners), Dermaptera (earwigs), Phasmatodea (walking sticks), Orthoptera s.s. (grasshoppers, crickets, bush-crickets) and Dictyoptera with the suborders Mantodea (mantids), Blattaria (cockroaches) and Isoptera (termites). For the Orthopteroid orders, data from 35 families containing 1,371 species are included in this paper.

  18. Fauna Europaea - Orthopteroid orders.

    PubMed

    Heller, Klaus-Gerhard; Bohn, Horst; Haas, Fabian; Willemse, Fer; de Jong, Yde

    2016-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant European terrestrial and freshwater animals, their geographical distribution at the level of countries and major islands (west of the Urals and excluding the Caucasus region), and some additional information. The Fauna Europaea project comprises about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. Fauna Europaea represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. The "Orthopteroid orders" is one of the 58 Fauna Europaea major taxonomic groups. It contains series of mostly well-known insect orders: Embiodea (webspinners), Dermaptera (earwigs), Phasmatodea (walking sticks), Orthoptera s.s. (grasshoppers, crickets, bush-crickets) and Dictyoptera with the suborders Mantodea (mantids), Blattaria (cockroaches) and Isoptera (termites). For the Orthopteroid orders, data from 35 families containing 1,371 species are included in this paper.

  19. Fauna Europaea - Orthopteroid orders.

    PubMed

    Heller, Klaus-Gerhard; Bohn, Horst; Haas, Fabian; Willemse, Fer; de Jong, Yde

    2016-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant European terrestrial and freshwater animals, their geographical distribution at the level of countries and major islands (west of the Urals and excluding the Caucasus region), and some additional information. The Fauna Europaea project comprises about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. Fauna Europaea represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. The "Orthopteroid orders" is one of the 58 Fauna Europaea major taxonomic groups. It contains series of mostly well-known insect orders: Embiodea (webspinners), Dermaptera (earwigs), Phasmatodea (walking sticks), Orthoptera s.s. (grasshoppers, crickets, bush-crickets) and Dictyoptera with the suborders Mantodea (mantids), Blattaria (cockroaches) and Isoptera (termites). For the Orthopteroid orders, data from 35 families containing 1,371 species are included in this paper. PMID:27660531

  20. Insect phylogenomics: results, problems and the impact of matrix composition.

    PubMed

    Letsch, Harald O; Meusemann, Karen; Wipfler, Benjamin; Schütte, Kai; Beutel, Rolf; Misof, Bernhard

    2012-08-22

    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

  1. Differential ant exclusion from canopies shows contrasting top-down effects on community structure.

    PubMed

    Mestre, Laia; Piñol, J; Barrientos, J A; Espadaler, X

    2016-01-01

    Predators have far-reaching effects on communities by triggering top-down trophic cascades that influence ecosystem functioning. Omnivory and intraguild interactions between predators give rise to reticulate food webs and may either strengthen or dampen trophic cascades depending on context. Disentangling the effects of multiple predator species is therefore crucial for predicting the influence of predators on community structure. We focused on ants as dominant generalist predators in arthropod communities and set up a differential ant exclusion from canopies to examine its effects on assemblage species composition and densities of five arthropod groups (psocopterans, aphids, spiders, heteropterans and beetles). We coupled a glue band with tubes allowing only the ant Lasius grandis to reach the canopies to isolate its effect from the rest of crawling predators (ants, earwigs) and compared it against a full exclusion and a control. L. grandis alone had widespread effects on assemblage species composition, with contrasting species-specific responses within groups, where some species affected by L. grandis presence were not further affected by the presence of the whole crawling predator assemblage, and vice versa. Overall, L. grandis caused two- to threefold decreases of generalist predators and a threefold increase of aphids. However, it lacked further top-down effects on primary consumers, which only emerged when all crawling predators were present. This differential exclusion demonstrates the distinctive and widespread intraguild effects on community structure of a single ant species that contrast with the top-down effects exerted by the whole crawling predator assemblage. PMID:26376660

  2. Fauna Europaea – Orthopteroid orders

    PubMed Central

    Bohn, Horst; Haas, Fabian; Willemse, Fer

    2016-01-01

    Abstract Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant European terrestrial and freshwater animals, their geographical distribution at the level of countries and major islands (west of the Urals and excluding the Caucasus region), and some additional information. The Fauna Europaea project comprises about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. Fauna Europaea represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. The “Orthopteroid orders“ is one of the 58 Fauna Europaea major taxonomic groups. It contains series of mostly well-known insect orders: Embiodea (webspinners), Dermaptera (earwigs), Phasmatodea (walking sticks), Orthoptera s.s. (grasshoppers, crickets, bush-crickets) and Dictyoptera with the suborders Mantodea (mantids), Blattaria (cockroaches) and Isoptera (termites). For the Orthopteroid orders, data from 35 families containing 1,371 species are included in this paper. PMID:27660531

  3. A chemical signal of offspring quality affects maternal care in a social insect

    PubMed Central

    Mas, Flore; Haynes, Kenneth F.; Kölliker, Mathias

    2009-01-01

    Begging signals of offspring are condition-dependent cues that are usually predicted to display information about the short-term need (i.e. hunger) to which parents respond by allocating more food. However, recent models and experiments have revealed that parents, depending on the species and context, may respond to signals of quality (i.e. offspring reproductive value) rather than need. Despite the critical importance of this distinction for life history and conflict resolution theory, there is still limited knowledge of alternative functions of offspring signals. In this study, we investigated the communication between offspring and caring females of the common earwig, Forficula auricularia, hypothesizing that offspring chemical cues display information about nutritional condition to which females respond in terms of maternal food provisioning. Consistent with the prediction for a signal of quality we found that mothers exposed to chemical cues from well-fed nymphs foraged significantly more and allocated food to more nymphs compared with females exposed to solvent (control) or chemical cues from poorly fed nymphs. Chemical analysis revealed significant differences in the relative quantities of specific cuticular hydrocarbon compounds between treatments. To our knowledge, this study demonstrates for the first time that an offspring chemical signal reflects nutritional quality and influences maternal care. PMID:19439438

  4. Diet of western Burrowing Owls wintering in southern Texas

    USGS Publications Warehouse

    Littles, C.J.; Williford, D.; Skoruppa, M.K.; Woodin, M.C.; Hickman, G.C.

    2007-01-01

    Winter diets of the western Burrowing Owl (Athene cunicularia hypugaea) are little known. We determined the diet of western Burrowing Owls wintering in southern Texas by analyzing the contents of 182 pellets collected over four winters (1999-2000, 2001-2002, 2002-2003, and 2003-2004) in three habitat types (agricultural, mainland grassland, and barrier island). Remains of a total of 7476 prey items were recovered, 98% of which were arthropods. Gryllidae (crickets) formed the largest component (50%) of the prey, followed by lepidopteran larvae (13%), beetles (8%), spiders (7%), and earwigs (6%). Although vertebrates, primarily small mammals and birds, represented only 2% of prey items by number, they represented most (71%) of the biomass. Northern pygmy mice (Baiomys taylori) and fulvous harvest mice (Reithrodontomys fulveccens) were the two most frequently consumed vertebrate species. In all habitats, arthropods, especially orthopterans, were the primary prey item by number, whereas vertebrates, primarily small mammals, were the most important by biomass. Greater consumption of arthropods by Burrowing Owls in agricultural areas may be a factor contributing to owl use of these highly altered environments. ?? 2007 The Raptor Research Foundation, Inc.

  5. Alarm Odor Compounds of the Brown Marmorated Stink Bug Exhibit Antibacterial Activity

    PubMed Central

    Sagun, Steven; Collins, Elliot; Martin, Caleb; Nolan, E Joseph; Horzempa, Joseph

    2016-01-01

    Some insects release scented compounds as a defense against predators that also exhibit antimicrobial activity. Trans-2-octenal and trans-2-decenal are the major alarm aldehydes responsible for the scent of Halyomorpha halys, the brown marmorated stink bug. Previous research has shown these aldehydes are antifungal and produce an antipredatory effect, but have never been tested for antibacterial activity. We hypothesized that these compounds functioned similarly to the analogous multifunctional action of earwig compounds, so we tested whether these aldehydes could inhibit the growth of bacteria. Disk diffusion assays indicated that these aldehydes significantly inhibited the growth of Methicillin-resistant Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, in vitro. Moreover, mealworm beetles (Tenebrio molitor) coated in stink bug aldehydes showed a substantial reduction in bacterial colonization compared to vehicle-treated insects. These results suggest that brown marmorated stinkbug aldehydes are indeed antibacterial agents and serve a multifunctional role for this insect. Therefore, stinkbug aldehydes may have potential for use as chemical antimicrobials.

  6. Alarm Odor Compounds of the Brown Marmorated Stink Bug Exhibit Antibacterial Activity

    PubMed Central

    Sagun, Steven; Collins, Elliot; Martin, Caleb; Nolan, E Joseph; Horzempa, Joseph

    2016-01-01

    Some insects release scented compounds as a defense against predators that also exhibit antimicrobial activity. Trans-2-octenal and trans-2-decenal are the major alarm aldehydes responsible for the scent of Halyomorpha halys, the brown marmorated stink bug. Previous research has shown these aldehydes are antifungal and produce an antipredatory effect, but have never been tested for antibacterial activity. We hypothesized that these compounds functioned similarly to the analogous multifunctional action of earwig compounds, so we tested whether these aldehydes could inhibit the growth of bacteria. Disk diffusion assays indicated that these aldehydes significantly inhibited the growth of Methicillin-resistant Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, in vitro. Moreover, mealworm beetles (Tenebrio molitor) coated in stink bug aldehydes showed a substantial reduction in bacterial colonization compared to vehicle-treated insects. These results suggest that brown marmorated stinkbug aldehydes are indeed antibacterial agents and serve a multifunctional role for this insect. Therefore, stinkbug aldehydes may have potential for use as chemical antimicrobials. PMID:27656692

  7. 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

  8. Treating epilepsy: a review of Polish historical sources.

    PubMed

    Owczarek, Krzysztof

    2011-10-01

    The first surviving Polish publications on epilepsy were written in the 16th and 17th centuries. Many causes of epileptic seizures are quoted and they are divided into two categories: internal and external. Internal causes (causa interna) include imbalance in the basic bodily humors, that is, yellow bile, black bile, phlegm, and blood. According to medieval writers, the principal cause of epilepsy was vapor, a damp, cold volatile substance originating in the excessive production of one of the basic organismic liquids. Vapor allegedly stuck to the openings leading to the cerebral ventricles or blocked them entirely, resulting in convulsions. External causes (causa externa) include overeating and excessive drinking, teething, spoiled milk, poisons, badly treated spots and fever, cold air, moonlight, and wearing donkey hide. Medical treatments for epilepsy included surgical interventions (bloodletting) and pharmacological interventions. The latter included laxatives, sea onion (scilla maritima, urginea maritima), and ground human skull, all of which were supposed to protect the body from vapors. Medical practitioners of that time also advised that the factors and circumstances conducive to epileptic seizures be observed and identified so that patients could be isolated from these alleged causal factors and their seizures reduced or ended.

  9. 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

  10. 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

  11. Development of bait formulations for control of intermediate hosts of African schistosome species.

    PubMed

    Abdel-Hamid, A Z

    1997-01-01

    Exploration of methods of snail control indicated a need for a new method because many failures in control programmes are due to lack of contact between molluscicides and the target snail population. The incorporation of molluscicides inside food pellets that are attractive to and ingestible by the target snails is suggested. Different concentrations of alcoholic extracts of Ambrosia maritima, Cucumis prophetarum and Rhynchosia minima-molluscicides of plant origin-were compared with niclosamide (Bayluscide) which is a strong synthetic molluscicide. They were incorporated into attractive food pellets and the lethal doses were determined. The results showed that Biomphalaria alexandrina snails are sensitive to only bait formulations with low concentrations of molluscicides. Laboratory and semi-field trials were conducted to study the efficacy of the prepared bait formulations on Biomphalaria alexandrina snails. The stability of these bait formulations was studied and it was observed that their effectiveness was reduced after long storage periods (> 3 weeks). The results revealed that Ambrosia maritima was the most effective molluscicide.

  12. Boosting dark fermentation with co-cultures of extreme thermophiles for biohythane production from garden waste.

    PubMed

    Abreu, Angela A; Tavares, Fábio; Alves, Maria Madalena; Pereira, Maria Alcina

    2016-11-01

    Proof of principle of biohythane and potential energy production from garden waste (GW) is demonstrated in this study in a two-step process coupling dark fermentation and anaerobic digestion. The synergistic effect of using co-cultures of extreme thermophiles to intensify biohydrogen dark fermentation is demonstrated using xylose, cellobiose and GW. Co-culture of Caldicellulosiruptor saccharolyticus and Thermotoga maritima showed higher hydrogen production yields from xylose (2.7±0.1molmol(-1) total sugar) and cellobiose (4.8±0.3molmol(-1) total sugar) compared to individual cultures. Co-culture of extreme thermophiles C. saccharolyticus and Caldicellulosiruptor bescii increased synergistically the hydrogen production yield from GW (98.3±6.9Lkg(-1) (VS)) compared to individual cultures and co-culture of T. maritima and C. saccharolyticus. The biochemical methane potential of the fermentation end-products was 322±10Lkg(-1) (CODt). Biohythane, a biogas enriched with 15% hydrogen could be obtained from GW, yielding a potential energy generation of 22.2MJkg(-1) (VS).

  13. Light-dark O2 dynamics in submerged leaves of C3 and C4 halophytes under increased dissolved CO2: clues for saltmarsh response to climate change.

    PubMed

    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

  14. Boosting dark fermentation with co-cultures of extreme thermophiles for biohythane production from garden waste.

    PubMed

    Abreu, Angela A; Tavares, Fábio; Alves, Maria Madalena; Pereira, Maria Alcina

    2016-11-01

    Proof of principle of biohythane and potential energy production from garden waste (GW) is demonstrated in this study in a two-step process coupling dark fermentation and anaerobic digestion. The synergistic effect of using co-cultures of extreme thermophiles to intensify biohydrogen dark fermentation is demonstrated using xylose, cellobiose and GW. Co-culture of Caldicellulosiruptor saccharolyticus and Thermotoga maritima showed higher hydrogen production yields from xylose (2.7±0.1molmol(-1) total sugar) and cellobiose (4.8±0.3molmol(-1) total sugar) compared to individual cultures. Co-culture of extreme thermophiles C. saccharolyticus and Caldicellulosiruptor bescii increased synergistically the hydrogen production yield from GW (98.3±6.9Lkg(-1) (VS)) compared to individual cultures and co-culture of T. maritima and C. saccharolyticus. The biochemical methane potential of the fermentation end-products was 322±10Lkg(-1) (CODt). Biohythane, a biogas enriched with 15% hydrogen could be obtained from GW, yielding a potential energy generation of 22.2MJkg(-1) (VS). PMID:27484669

  15. Crystal Structure of the First Eubacterial Mre11 Nuclease Reveals Novel Features that may Discriminate Substrates During DNA Repair

    PubMed Central

    Das, Debanu; Moiani, Davide; Axelrod, Herbert L.; Miller, Mitchell D.; McMullan, Daniel; Jin, Kevin K.; Abdubek, Polat; Astakhova, Tamara; Burra, Prasad; Carlton, Dennis; Chiu, Hsiu-Ju; Clayton, Thomas; Deller, Marc C.; Duan, Lian; Ernst, Dustin; Feuerhelm, Julie; Grant, Joanna C.; Grzechnik, Anna; Grzechnik, Slawomir K.; Han, Gye Won; Jaroszewski, Lukasz; Klock, Heath E.; Knuth, Mark W.; Kozbial, Piotr; Krishna, S. Sri; Kumar, Abhinav; Marciano, David; Morse, Andrew T.; Nigoghossian, Edward; Okach, Linda; Paulsen, Jessica; Reyes, Ron; Rife, Christopher L.; Sefcovic, Natasha; Tien, Henry J.; Trame, Christine B.; van den Bedem, Henry; Weekes, Dana; Xu, Qingping; Hodgson, Keith O.; Wooley, John; Elsliger, Marc-André; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Tainer, John A.; Wilson, Ian A.

    2010-01-01

    Mre11 nuclease plays a central role in the repair of cytotoxic and mutagenic DNA double-strand breaks (DSBs). As x-ray structural information has only been available for the Pyrococcus furiosus enzyme (PfMre11), the conserved and variable features of this nuclease across the domains of life have not been experimentally defined. Our crystal structure and biochemical studies demonstrate that TM1635 from Thermotoga maritima, originally annotated as a putative nuclease, is the Mre11 endo/exonuclease from T. maritima (TmMre11) and the first such structure from eubacteria. TmMre11 and PfMre11 display similar overall structures, despite sequence identity in the twilight zone of only ∼20%. However, they differ substantially in their DNA specificity domains and in their dimeric organization. Residues in the nuclease domain are highly conserved, but those in the DNA specificity domain are not. The structural differences likely affect how Mre11s from different organisms recognize and interact with single-stranded DNA, double-stranded DNA and DNA hairpin structures during DNA repair. The TmMre11 nuclease active site has no bound metal ions, but is conserved in sequence and structure with exception of a histidine that is important in PfMre11 nuclease activity. Nevertheless, biochemical characterization confirms that TmMre11 possesses both endonuclease and exonuclease activities on ssDNA and dsDNA substrates, respectively. PMID:20122942

  16. The effects of olive mill waste compost and poultry manure on the availability and plant uptake of nutrients in a highly saline soil.

    PubMed

    Walker, David J; Bernal, M Pilar

    2008-01-01

    The effects of a compost (produced from by-products of the olive oil industry) and a poultry manure on mineral ion solubility and exchangeability in a highly saline agricultural soil (electrical conductivity for a 1:5 soil:water extract=1.85 dS m(-1)) from Murcia (SE Spain) were studied. The organic amendments did not change significantly the soil electrical conductivity or the soluble Na(+), Ca(2+) or Mg(2+). Only soluble K(+) increased, due to the K(+) supplied by the amendments. The cation exchange capacity increased in treated soils, the exchange complex being mainly saturated with Ca(2+), Mg(2+) and K(+). However, Na(+) was not retained in the exchange sites, and the sodium absorption ratio remained low. The compost and manure increased markedly the shoot growth of the salt-tolerant Beta maritima L. (sea beet) and Beta vulgaris L. (sugar beet). For B. maritima, this seemed to be related to decreases in the shoot concentrations of Na(+) and Cl(-) and increases in K(+) and H(2)PO(4)(-). In the case of B. vulgaris, increases in shoot H(2)PO(4)(-) and B and, for manure-treated soil, a decrease in shoot Na(+) may have been involved. Cultivation of tomato (Lycopersicon esculentum Mill. cv. Moneymaker) in the soil used previously for B. vulgaris indicated that the effects of the manure on tissue cation concentrations were longer-lasting than those of the compost.

  17. Remispora spitsbergenensis sp. nov., a marine lignicolous ascomycete from Svalbard, Norway.

    PubMed

    Pang, Ka-Lai; Chiang, Michael W L; Vrijmoed, Lilian L P

    2009-01-01

    Abstract: Remispora was established for R. maritima, a fungus with globose/subglobose, lightly colored and coriaceous ascomata; deliquescing asci; ellipsoidal ascospores; and bipolar, pleomorphic ascospore appendages. Seven species currently are included in Remispora: R crispa, R. galerita, R maritima, R. minuta, R. pilleata, R. quadriremis and R stellata. Variations on ascospore appendages can be observed in Remispora. In general the appendage is exosporic in nature and comprises an amorphous, electron-transparent matrix, and a fibrous, electron-dense component. An eighth Remispora species, R. spitsbergenensis sp. nov., is described here, discovered from washed-up wood collected at the shore of Longyearbyen, Svalbard, Norway. Ascospore appendages of R. spitsbergenensis appear as fibrous strands and amorphic material under the scanning electron microscope, which are characteristic of a Remispora species. Remispora spitsbergenensis resembles R. quadriremis and R. stellata because all possess four or more ascospore appendages at one end. Remispora spitsbergenensis possesses consistently four polar appendages at each end in contrast to six in R. stellata. Also ascospore appendages of R. spitsbergenensis are ribbon-like, compared with the obclavate, curved and attenuate appendages in R. quadriremis and R. stellata. A key for the identification of the eight Remispora species is provided.

  18. Light-dark O2 dynamics in submerged leaves of C3 and C4 halophytes under increased dissolved CO2: clues for saltmarsh response to climate change.

    PubMed

    Duarte, B; Santos, D; Silva, H; Marques, J C; Caçador, I; Sleimi, N

    2014-11-07

    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.

  19. More than one way to produce protein diversity: duplication and limited alternative splicing of an adhesion molecule gene in basal arthropods.

    PubMed

    Brites, Daniela; Brena, Carlo; Ebert, Dieter; Du Pasquier, Louis

    2013-10-01

    Exon duplication and alternative splicing evolved multiple times in metazoa and are of overall importance in shaping genomes and allowing organisms to produce many fold more proteins than there are genes in the genome. No other example is as striking as the one of the Down syndrome cell adhesion molecule (Dscam) of insects and crustaceans (pancrustaceans) involved in the nervous system differentiation and in the immune system. To elucidate the evolutionary history of this extraordinary gene, we investigated Dscam homologs in two basal arthropods, the myriapod Strigamia maritima and the chelicerate Ixodes scapularis. In both, Dscam diversified extensively by whole gene duplications resulting in multigene expansions. Within some of the S. maritima genes, exons coding for one of the immunoglobulin domains (Ig7) duplicated and are mutually exclusively alternatively spliced. Our results suggest that Dscam diversification was selected independently in chelicerates, myriapods, and pancrustaceans and that the usage of Dscam diversity by immune cells evolved for the first time in basal arthropods. We propose an evolutionary scenario for the appearance of the highly variable Dscam gene of pancrustaceans, adding to the understanding of how alternative splicing, exon, and gene duplication contribute to create molecular diversity associated with potentially new cellular functions.

  20. The effects of olive mill waste compost and poultry manure on the availability and plant uptake of nutrients in a highly saline soil.

    PubMed

    Walker, David J; Bernal, M Pilar

    2008-01-01

    The effects of a compost (produced from by-products of the olive oil industry) and a poultry manure on mineral ion solubility and exchangeability in a highly saline agricultural soil (electrical conductivity for a 1:5 soil:water extract=1.85 dS m(-1)) from Murcia (SE Spain) were studied. The organic amendments did not change significantly the soil electrical conductivity or the soluble Na(+), Ca(2+) or Mg(2+). Only soluble K(+) increased, due to the K(+) supplied by the amendments. The cation exchange capacity increased in treated soils, the exchange complex being mainly saturated with Ca(2+), Mg(2+) and K(+). However, Na(+) was not retained in the exchange sites, and the sodium absorption ratio remained low. The compost and manure increased markedly the shoot growth of the salt-tolerant Beta maritima L. (sea beet) and Beta vulgaris L. (sugar beet). For B. maritima, this seemed to be related to decreases in the shoot concentrations of Na(+) and Cl(-) and increases in K(+) and H(2)PO(4)(-). In the case of B. vulgaris, increases in shoot H(2)PO(4)(-) and B and, for manure-treated soil, a decrease in shoot Na(+) may have been involved. Cultivation of tomato (Lycopersicon esculentum Mill. cv. Moneymaker) in the soil used previously for B. vulgaris indicated that the effects of the manure on tissue cation concentrations were longer-lasting than those of the compost. PMID:17275292

  1. Distribution and migration of seaside sparrows

    USGS Publications Warehouse

    Robbins, C.S.; Quay, Thomas; Funderberg, John B.=; Lee, David S.; Potter, Eloise F.; 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.

  2. 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; Orcić, Dejan Z; Mimica-Dukić, 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

  3. Hydrogen transfer between methanogens and fermentative heterotrophs in hyperthermophilic cocultures

    SciTech Connect

    Muralidharan, V.; Hirsh, I.S.; Bouwer, E.J.; Rinker, K.D.; Kelly, R.M.

    1997-11-05

    Interactions involving hydrogen transfer were studied in a coculture of two hyperthermophilic microorganisms: Thermotoga maritima, an anaerobic heterotroph, and Methanococcus jannaschii, a hydrogenotrophic methanogen. Cell densities of T. maritima increased 10-fold when cocultured with M. jannaschii at 85 C, and the methanogen was able to grow in the absence of externally supplied H{sub 2} and CO{sub 2}. The coculture could not be established if the two organisms were physically separated by a dialysis membrane, suggesting the importance of spatial proximity. The significance of spatial proximity was also supported by cell cytometry, where the methanogen was only found in cell sorts at or above 4.5 {micro}m in samples of the coculture in exponential phase. An unstructured mathematical model was used to compare the influence of hydrogen transport and metabolic properties on mesophilic and hyperthermophilic cocultures. Calculations suggest the increases in methanogenesis rates with temperature result from greater interactions between the methanogenic and fermentative organisms, as evidenced by the sharp decline in H{sub 2} concentration in the proximity of a hyperthermophilic methanogen. The experimental and modeling results presented here illustrate the need to consider the interactions within hyperthermophilic consortia when choosing isolation strategies and evaluating biotransformations at elevated temperatures.

  4. Conformational Flexibility and Peptide Interaction of the Translocation ATPase SecA

    SciTech Connect

    Zimmer, Jochen; Rapoport, Tom A.; Harvard-Med

    2010-09-21

    The SecA ATPase forms a functional complex with the protein-conducting SecY channel to translocate polypeptides across the bacterial cell membrane. SecA recognizes the translocation substrate and catalyzes its unidirectional movement through the SecY channel. The recent crystal structure of the Thermotoga maritima SecA-SecYEG complex shows the ATPase in a conformation where the nucleotide-binding domains (NBDs) have closed around a bound ADP-BeFx complex and SecA's polypeptide-binding clamp is shut. Here, we present the crystal structure of T. maritima SecA in isolation, determined in its ADP-bound form at 3.1 {angstrom} resolution. SecA alone has a drastically different conformation in which the nucleotide-binding pocket between NBD1 and NBD2 is open and the preprotein cross-linking domain has rotated away from both NBDs, thereby opening the polypeptide-binding clamp. To investigate how this clamp binds polypeptide substrates, we also determined a structure of Bacillus subtilis SecA in complex with a peptide at 2.5 {angstrom} resolution. This structure shows that the peptide augments the highly conserved {beta}-sheet at the back of the clamp. Taken together, these structures suggest a mechanism by which ATP hydrolysis can lead to polypeptide translocation.

  5. Distance to semi-natural grassland influences seed production of insect-pollinated herbs.

    PubMed

    Jakobsson, Anna; Ågren, Jon

    2014-05-01

    Marginal grassland fragments, such as road verges and field margins, may act as important supplemental habitats for grassland plants in the modern agricultural landscape. However, abundance of pollinators in such fragments has been found to decline with distance to larger natural and semi-natural habitats, and this could have corresponding effects on plant pollination. In this study, we performed a field experiment on road verges with three insect-pollinated grassland herbs to examine the relationship between distance to semi-natural grassland and plant reproductive success in two landscapes with contrasting farming intensities. In Lychnis viscaria and Lotus corniculatus, seed production tended to decrease with increasing distance to semi-natural grassland, but only in the landscape with high farming intensity. Seed production in Armeria maritima spp. maritima decreased with distance in both landscapes. Although many studies have investigated effects of natural habitat on crop pollination, little is known about the impact on pollination in native plants. The results from this study indicate that management of semi-natural grasslands improves not only biodiversity within the actual grassland but also pollination of native plants in the surrounding agricultural landscape.

  6. Functional Analysis of Amorpha-4,11-Diene Synthase (ADS) Homologs from Non-Artemisinin-Producing Artemisia Species: The Discovery of Novel Koidzumiol and (+)-α-Bisabolol Synthases.

    PubMed

    Muangphrom, Paskorn; Seki, Hikaru; Suzuki, Munenori; Komori, Aya; Nishiwaki, Mika; Mikawa, Ryota; Fukushima, Ery Odette; Muranaka, Toshiya

    2016-08-01

    The production of artemisinin, the most effective antimalarial compound, is limited to Artemisia annua. Enzymes involved in artemisinin biosynthesis include amorpha-4,11-diene synthase (ADS), amorpha-4,11-diene 12-monooxygenase (CYP71AV1) and artemisinic aldehyde Δ(11)13 reductase (DBR2). Although artemisinin and its specific intermediates are not detected in other Artemisia species, we reported previously that CYP71AV1 and DBR2 homologs were expressed in some non-artemisinin-producing Artemisia plants. These homologous enzymes showed similar functions to their counterparts in A. annua and can convert fed intermediates into the following products along the artemisinin biosynthesis in planta These findings suggested a partial artemisinin-producing ability in those species. In this study, we examined genes highly homologous to ADS, the first committed gene in the pathway, in 13 Artemisia species. We detected ADS homologs in A. absinthium, A. kurramensis and A. maritima. We analyzed the enzymatic functions of all of the ADS homologs after obtaining their cDNA. We found that the ADS homolog from A. absinthium exhibited novel activity in the cyclization of farnesyl pyrophosphate (FPP) to koidzumiol, a rare natural sesquiterpenoid. Those from A. kurramensis and A. maritima showed similar, but novel, activities in the cyclization of FPP to (+)-α-bisabolol. The unique functions of the novel sesquiterpene synthases highly homologous to ADS found in this study could provide insight into the molecular basis of the exceptional artemisinin-producing ability in A. annua. PMID:27273626

  7. Antioxidant activity of raw, cooked and Rhizopus oligosporus fermented beans of Canavalia of coastal sand dunes of Southwest India.

    PubMed

    Niveditha, Vedavyas R; Sridhar, Kandikere R

    2014-11-01

    The raw and processed (cooked and cooked + solid-state fermented with Rhizopus oligosporus) split beans of two landraces of coastal sand dune wild legumes (Canavalia cathartica and Canavalia maritima) of the southwest coast of India were examined for bioactive compounds (total phenolics, tannins and vitamin C) and antioxidant potential (total antioxidant activity, ferrous-ion chelating capacity, DPPH free radical-scavenging activity and reducing activity). One-way ANOVA revealed significant elevation of bioactive compounds as well as antioxidant activities in fermented beans compared to raw and cooked beans in both legumes (p < 0.001). The EC50 values in fermented beans of both legumes were significantly lowest compared to raw and cooked beans (p < 0.001). In principal component analysis, total phenolics along with antioxidant activities (total antioxidant, ferrous-ion chelating and free radical-scavenging activities) of fermented beans of C. cathartica, while total antioxidant and free radical-scavenging activities of fermented beans of C. maritima were clustered. The present study demonstrated that split beans of coastal sand dune Canavalia fermented by R. oligosporus endowed with high bioactive principles as well as antioxidant potential and thus serve as future nutraceutical source.

  8. An ecological approach to measuring the evolutionary consequences of gene flow from crops to wild or weedy relatives1

    PubMed Central

    Campbell, Lesley G.; Lee, David; Shukla, Kruti; Waite, Thomas A.; Bartsch, Detlef

    2016-01-01

    Premise of the study: Agricultural practices routinely create opportunities for crops to hybridize with wild relatives, leading to crop gene introgression into wild genomes. Conservationists typically worry this introgression could lead to genetic homogenization of wild populations, over and above the central concern of transgene escape. Alternatively, viewing introgression as analogous to species invasion, we suggest that increased genetic diversity may likewise be an undesirable outcome. Methods: Here, we compare the sensitivity of conventional population genetic metrics with species diversity indices as indicators of the impact of gene flow on genetic diversity. We illustrate this novel approach using multilocus genotype data (12 allozyme loci) from 10 wild (Beta vulgaris subsp. maritima) and eight putative crop–wild hybrid beet populations (B. vulgaris subsp. vulgaris × B. vulgaris subsp. maritima) scattered throughout Europe. Results: Conventional population genetic metrics mostly failed to detect shifts in genetic composition of putative hybrid populations. By contrast, species diversity indices unambiguously revealed increased genetic diversity in putative hybrid populations. Discussion: We encourage other workers to explore the utility of our more sensitive approach for risk assessment prior to the release of transgenic crops, with a view toward widespread adoption of our method in studies aimed at detecting allelic invasion. PMID:27011898

  9. Organism traits determine the strength of scale-dependent bio-geomorphic feedbacks: A flume study on three intertidal plant species

    NASA Astrophysics Data System (ADS)

    Bouma, T. J.; Temmerman, S.; van Duren, L. A.; Martini, E.; Vandenbruwaene, W.; Callaghan, D. P.; Balke, T.; Biermans, G.; Klaassen, P. C.; van Steeg, P.; Dekker, F.; van de Koppel, J.; de Vries, M. B.; Herman, P. M. J.

    2013-01-01

    There is a growing recognition of the important role of scale-dependent feedback for biogeomorphological landscape formation, where organisms locally improve survival and growth but at the same time negatively affect organisms at larger distance. However, little is known on how scale-dependent bio-geomorphic feedback is influenced by organism traits in combination with abiotic forcing. This was studied by measuring in a flume, the flow patterns around patches of three contrasting marsh species (Spartina anglica, Puccinellia maritima and Salicornia procumbens), using the flow acceleration around vegetation patches and deceleration within vegetation patches as quantitative proxy for the negative and positive feedback to the vegetation performance. The importance of external forcing was assessed by comparing three realistic current velocities: 0.1, 0.2 and 0.3 m s- 1. Our results showed that the dense clonal growth of stiff Spartina anglica shoots caused strongest flow deviations, irrespective of the applied current velocity. In contrast, the more sparsely growing, shorter stiff shoots of Salicornia procumbens induced much less flow deviation, allowing more water to pass through and over the vegetation canopy. The dense but highly flexible shoots of Puccinellia maritima caused strong flow deviations at low velocities, which diminished at higher velocities due to bending of the vegetation. Overall, these hydrodynamic results demonstrate that plant species traits interact with environmental conditions in creating scale-dependent feedbacks explaining why the effects of vegetation on landscape formation in saltmarshes are species specific.

  10. A thermostable recombinant transaldolase with high activity over a broad pH range.

    PubMed

    Huang, Song-Yan; Zhang, Y-H Percival; Zhong, Jian-Jiang

    2012-03-01

    Thermophilic enzymes are in high demand for various applications due to their prolonged lifetimes and high reaction rates at elevated temperatures. In this work, an open reading frame TM0295, which encodes a putative transaldolase (TAL) from a hyper-thermophilic microorganism, Thermotoga maritima, was cloned and expressed in Escherichia coli. The enzyme activity of transaldolase at high temperatures (e.g., at 80 °C) was reported here for the first time. The recombinant T. maritima transaldolase was extremely thermostable, with a half-life time of 198 and 13.0 h at 60 °C and 80 °C, respectively. The estimated total turn-over number was 1.5 × 10(6) mol of product per mol of enzyme at 80 °C. This enzyme also exhibited high activities within a broad pH range of 6.0-9.0. This ultra-thermostable TAL with high activity shows great potential for use in such applications as the production of enzymatic biofuels production and the synthesis of high-value carbohydrates by cell-free synthetic pathway biotransformation.

  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; Orcić, Dejan Z; Mimica-Dukić, 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.

  12. Patch clamp studies on root cell vacuoles of a salt-tolerant and a salt-sensitive plantago species : regulation of channel activity by salt stress.

    PubMed

    Maathuis, F J; Prins, H B

    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(+), P(K) (+)/P(Na) (+) = 1, whereas the cation/anion selectivity (P(K) (+)/P(c1) (-)) 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 (t((1/2)) = 1.2 second). Inwardly directed, ATP-dependent currents could be measured against a DeltapH 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.

  13. 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.

  14. Tagus estuary and Ria de Aveiro salt marsh dynamics and the impact of sea level rise

    NASA Astrophysics Data System (ADS)

    Valentim, J. M.; Vaz, N.; Silva, H.; Duarte, B.; Caçador, I.; Dias, J. M.

    2013-09-01

    Different characteristics of Spartina maritima found in two distinct salt marshes located in different estuaries were analysed through interpretation of their local hydrodynamic patterns, as well as the impact of sea level rise on physical processes and consequently on plant dynamics and salt marshes stability. These salt marshes are situated in two of the most important Portuguese coastal systems, Tagus estuary (Rosário salt marsh) and Ria de Aveiro lagoon (Barra salt marsh), which are dominated by physical processes that induce strong tidal currents. They were monitored during one year and plant and sediment samples of S. maritima were collected quarterly in order to determine the vegetation coverage, above and belowground biomass, organic matter and sediment moisture. Residual circulation, tidal asymmetry and tidal dissipation were determined from numerical modelling results of the MOHID 2D model that was applied to each coastal system, considering the actual sea level and a sea level rise (SLR) scenario. Results suggest that the different characteristics found for Spartina maritima in the Rosário and the Barra salt marshes may be related with the diverse hydrodynamic conditions identified for each salt marsh. Consequently, the exploration of SLR scenario predictions indicates how these salt marshes could evolve in the future, showing that the important changes in these hydrodynamic parameters under climate change context might induce significant modifications in the salt marshes dynamics and stability. SLR scenario could lead to changes in nutrients and sediments patterns around the salt marshes and thus vegetation coverage percentage would be affected. Additionally, as a consequence of flood duration increase, sediment moisture will increase causing a stress condition to plants. Hence, the ratio below/aboveground biomass might increase, becoming critical to plants survival under conditions of accelerated sea level rise. Accordingly, both SLR and expected

  15. Nocturnal Plant Bugs Use cis-Jasmone to Locate Inflorescences of an Araceae as Feeding and Mating Site.

    PubMed

    Etl, Florian; Berger, Andreas; Weber, Anton; Schönenberger, Jürg; Dötterl, Stefan

    2016-04-01

    Inflorescences of Araceae pollinated by cyclocephaline scarab beetles are visited frequently by a wide array of other arthropods that exploit floral resources without taking part in pollination, including earwigs, flies, and true bugs. To date, nothing is known about the cues these insect visitors use to locate the inflorescences and whether or to what extent floral scents play a role. An aroid visited by large numbers of plant bugs (Miridae) in addition to cyclocephaline scarab beetle pollinators is the Neotropical species Dieffenbachia aurantiaca. We identified the plant bug species and investigated their behavior and arrival time on the inflorescences. To test the importance of olfactory cues in locating their host we conducted experiments with open and gauze-bagged inflorescences as well as natural scent samples of D. aurantiaca. Inflorescence scents were analyzed by gas chromatography linked to mass spectrometry (GC/MS), and the attractive potential of the main scent compound was determined by behavioral assays. Three species of Neella, the most common one being N. floridula, visited the inflorescences at nightfall, shortly after the beginning of scent emission, and showed feeding and copulation activity. Bagged inflorescences as well as natural scent samples attracted similar numbers of plant bugs as the non-bagged inflorescences, showing that olfactory cues are sufficient for them to locate their host. Cis-jasmone was the major component within the inflorescence scent bouquet. In two-choice field bioassays, this compound proved to be highly attractive to Neella, and thus obviously plays a key role in finding host plants. PMID:27074793

  16. Investigating the genetic architecture of conditional strategies using the environmental threshold model.

    PubMed

    Buzatto, Bruno A; Buoro, Mathieu; Hazel, Wade N; Tomkins, Joseph L

    2015-12-22

    The threshold expression of dichotomous phenotypes that are environmentally cued or induced comprise the vast majority of phenotypic dimorphisms in colour, morphology, behaviour and life history. Modelled as conditional strategies under the framework of evolutionary game theory, the quantitative genetic basis of these traits is a challenge to estimate. The challenge exists firstly because the phenotypic expression of the trait is dichotomous and secondly because the apparent environmental cue is separate from the biological signal pathway that induces the switch between phenotypes. It is the cryptic variation underlying the translation of cue to phenotype that we address here. With a 'half-sib common environment' and a 'family-level split environment' experiment, we examine the environmental and genetic influences that underlie male dimorphism in the earwig Forficula auricularia. From the conceptual framework of the latent environmental threshold (LET) model, we use pedigree information to dissect the genetic architecture of the threshold expression of forceps length. We investigate for the first time the strength of the correlation between observable and cryptic 'proximate' cues. Furthermore, in support of the environmental threshold model, we found no evidence for a genetic correlation between cue and the threshold between phenotypes. Our results show strong correlations between observable and proximate cues and less genetic variation for thresholds than previous studies have suggested. We discuss the importance of generating better estimates of the genetic variation for thresholds when investigating the genetic architecture and heritability of threshold traits. By investigating genetic architecture by means of the LET model, our study supports several key evolutionary ideas related to conditional strategies and improves our understanding of environmentally cued decisions. PMID:26674955

  17. A taste for exotic food: Neotropical land planarians feeding on an invasive flatworm.

    PubMed

    Boll, Piter K; Rossi, Ilana; Amaral, Silvana V; Leal-Zanchet, Ana

    2015-01-01

    Invasive species establish successfully in new habitats especially due to their ability to include new species in their diet and due to the freedom from natural enemies. However, native species may also adapt to the use of new elements in their ecosystem. The planarian Endeavouria septemlineata, first recorded in Hawaii, was later found in Brazil. Recently, we found it in human-disturbed areas in southern Brazil and here we investigate its interactions with other invertebrates both in the field and in the laboratory. We observed the species in the field during collecting activities and hence maintained some specimens alive in small terraria in the laboratory, where we offered different invertebrate species as potential prey and also put them in contact with native land planarians in order to examine their interaction. Both in the field and in the laboratory, E. septemlineata showed a gregarious behavior and was found feeding on woodlice, millipedes, earwigs and gastropods. In the laboratory, specimens often did not attack live prey, but immediately approached dead specimens, indicating a scavenging behavior. In an experiment using the slug Deroceras laeve and the woodlouse Atlantoscia floridana, there was a higher consumption of dead specimens of woodlice and slugs compared to live specimens, as well as a higher consumption of dead woodlice over dead slugs. Four native land planarians of the genus Obama and one of the genus Paraba attacked and consumed E. septemlineata, which, after the beginning of the attack, tried to escape by tumbling or using autotomy. As a scavenger, E. septemlineata would have no impact on the populations of species used as food, but could possibly exclude native scavengers by competition. On the other hand, its consumption by native land planarians may control its spread and thus reduce its impact on the ecosystem.

  18. Survival after pathogen exposure in group-living insects: don't forget the stress of social isolation!

    PubMed

    Kohlmeier, P; Holländer, K; Meunier, J

    2016-09-01

    A major cost of group-living is its inherent risk of pathogen infection. To limit this risk, many group-living animals have developed the capability to prophylactically boost their immune system in the presence of group members and/or to mount collective defences against pathogens. These two phenomena, called density-dependent prophylaxis and social immunity, respectively, are often used to explain why, in group-living species, individuals survive better in groups than in isolation. However, this survival difference may also reflect an alternative and often overlooked process: a cost of social isolation on individuals' capability to fight against infections. Here, we disentangled the effects of density-dependent prophylaxis, social immunity and stress of social isolation on the survival after pathogen exposure in group-living adults of the European earwig Forficula auricularia. By manipulating the presence of group members both before and after pathogen exposure, we demonstrated that the cost of being isolated after infection, but not the benefits of social immunity or density-dependent prophylaxis, explained the survival of females. Specifically, females kept constantly in groups or constantly isolated had higher survival rates than females that were first in groups and then isolated after infection. Our results also showed that this cost of social isolation was absent in males and that social isolation did not reduce the survival of noninfected individuals. Overall, this study gives a new perspective on the role of pathogens in social evolution, as it suggests that an apparently nonadaptive, personal immune process may promote the maintenance of group-living under pathogenic environments. PMID:27272199

  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. 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

  1. Survival after pathogen exposure in group-living insects: don't forget the stress of social isolation!

    PubMed

    Kohlmeier, P; Holländer, K; Meunier, J

    2016-09-01

    A major cost of group-living is its inherent risk of pathogen infection. To limit this risk, many group-living animals have developed the capability to prophylactically boost their immune system in the presence of group members and/or to mount collective defences against pathogens. These two phenomena, called density-dependent prophylaxis and social immunity, respectively, are often used to explain why, in group-living species, individuals survive better in groups than in isolation. However, this survival difference may also reflect an alternative and often overlooked process: a cost of social isolation on individuals' capability to fight against infections. Here, we disentangled the effects of density-dependent prophylaxis, social immunity and stress of social isolation on the survival after pathogen exposure in group-living adults of the European earwig Forficula auricularia. By manipulating the presence of group members both before and after pathogen exposure, we demonstrated that the cost of being isolated after infection, but not the benefits of social immunity or density-dependent prophylaxis, explained the survival of females. Specifically, females kept constantly in groups or constantly isolated had higher survival rates than females that were first in groups and then isolated after infection. Our results also showed that this cost of social isolation was absent in males and that social isolation did not reduce the survival of noninfected individuals. Overall, this study gives a new perspective on the role of pathogens in social evolution, as it suggests that an apparently nonadaptive, personal immune process may promote the maintenance of group-living under pathogenic environments.

  2. A taste for exotic food: Neotropical land planarians feeding on an invasive flatworm.

    PubMed

    Boll, Piter K; Rossi, Ilana; Amaral, Silvana V; Leal-Zanchet, Ana

    2015-01-01

    Invasive species establish successfully in new habitats especially due to their ability to include new species in their diet and due to the freedom from natural enemies. However, native species may also adapt to the use of new elements in their ecosystem. The planarian Endeavouria septemlineata, first recorded in Hawaii, was later found in Brazil. Recently, we found it in human-disturbed areas in southern Brazil and here we investigate its interactions with other invertebrates both in the field and in the laboratory. We observed the species in the field during collecting activities and hence maintained some specimens alive in small terraria in the laboratory, where we offered different invertebrate species as potential prey and also put them in contact with native land planarians in order to examine their interaction. Both in the field and in the laboratory, E. septemlineata showed a gregarious behavior and was found feeding on woodlice, millipedes, earwigs and gastropods. In the laboratory, specimens often did not attack live prey, but immediately approached dead specimens, indicating a scavenging behavior. In an experiment using the slug Deroceras laeve and the woodlouse Atlantoscia floridana, there was a higher consumption of dead specimens of woodlice and slugs compared to live specimens, as well as a higher consumption of dead woodlice over dead slugs. Four native land planarians of the genus Obama and one of the genus Paraba attacked and consumed E. septemlineata, which, after the beginning of the attack, tried to escape by tumbling or using autotomy. As a scavenger, E. septemlineata would have no impact on the populations of species used as food, but could possibly exclude native scavengers by competition. On the other hand, its consumption by native land planarians may control its spread and thus reduce its impact on the ecosystem. PMID:26500817

  3. A taste for exotic food: Neotropical land planarians feeding on an invasive flatworm

    PubMed Central

    Boll, Piter K.; Rossi, Ilana; Amaral, Silvana V.

    2015-01-01

    Invasive species establish successfully in new habitats especially due to their ability to include new species in their diet and due to the freedom from natural enemies. However, native species may also adapt to the use of new elements in their ecosystem. The planarian Endeavouria septemlineata, first recorded in Hawaii, was later found in Brazil. Recently, we found it in human-disturbed areas in southern Brazil and here we investigate its interactions with other invertebrates both in the field and in the laboratory. We observed the species in the field during collecting activities and hence maintained some specimens alive in small terraria in the laboratory, where we offered different invertebrate species as potential prey and also put them in contact with native land planarians in order to examine their interaction. Both in the field and in the laboratory, E. septemlineata showed a gregarious behavior and was found feeding on woodlice, millipedes, earwigs and gastropods. In the laboratory, specimens often did not attack live prey, but immediately approached dead specimens, indicating a scavenging behavior. In an experiment using the slug Deroceras laeve and the woodlouse Atlantoscia floridana, there was a higher consumption of dead specimens of woodlice and slugs compared to live specimens, as well as a higher consumption of dead woodlice over dead slugs. Four native land planarians of the genus Obama and one of the genus Paraba attacked and consumed E. septemlineata, which, after the beginning of the attack, tried to escape by tumbling or using autotomy. As a scavenger, E. septemlineata would have no impact on the populations of species used as food, but could possibly exclude native scavengers by competition. On the other hand, its consumption by native land planarians may control its spread and thus reduce its impact on the ecosystem. PMID:26500817

  4. Upon Further Review: VI. An Examination of Previous Lightcurve Analysis from the Palmer Divide Observatory

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.

    2011-04-01

    Updated results of lightcurve analysis are given for 31 asteroids previously reported from the Palmer Divide Observatory (PDO). The original images were remeasured to obtain new data sets using the latest version of MPO Canopus photometry software, analysis tools, and revised techniques for linking observing runs that ranged from several days to several weeks. Moderately to significantly different results were found for: 301 Bavaria, 436 Patricia, 507 Laodica, 549 Jessonda, 585 Bilkis, 596 Scheila, 607 Jenny, 630 Euphemia, 875 Nymphe, 912 Maritima, 926 Imhilde, 1177 Gonnessia, 1203 Nanna, 1333 Cevenola, 1679 Nevanlinna, 1796 Riga, 2000 Herschel, 2266 Tchaikovsky, 2460 Mitlincoln, 2494 Inge, 3915 Fukushima, 3940 Larion, 4091 Lowe, 4209 Briggs, 4431 Holeungholee, 4690 Strasbourg, 5390 Huichiming, 5940 Feliksobolev, (16558) 1991 VQ2, (18108) 2000 NT5, and (45646) 2000 EE45. This is expected to be the final paper in a current series that has examined results obtained during the initial years of the asteroid lightcurve program at PDO.

  5. 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.

  6. Biohydrogenesis in the Thermotogales

    SciTech Connect

    Kelly, Robert M

    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

  7. A redescription of Rhysida celeris (Humbert & Saussure, 1870), with a proposal of eight new synonyms (Scolopendromorpha, Scolopendridae, Otostigminae)

    PubMed Central

    Chagas-Júnior, Amazonas

    2013-01-01

    Abstract Seven species of the genus Rhysida Wood, 1862 from Venezuela and one subspecies from Peru described by Manuel Angel González Sponga and Wolfgang Bücherl respectively, are revised. Rhysida caripensis González-Sponga, 2002, Rhysida neoespartana González-Sponga, 2002, Rhysida guayanica González-Sponga, 2002, Rhysida maritima González-Sponga, 2002, Rhysida monaguensis González-Sponga, 2002, Rhysida porlamarensis González-Sponga 2002, Rhysida sucupanensis González-Sponga, 2002 and Rhysida celeris andina Bücherl, 1953 are junior synonyms of Rhysida celeris (Humbert & Saussure, 1870), which is redescribed and illustrated for the first time. Its geographic distribution is updated and a map showing its distribution is presented. PMID:23653497

  8. Proteolysis in hyperthermophilic microorganisms

    DOE PAGES

    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 genus Pyrococcus , the crenarchaeote Sulfolobus solfataricus , and the bacterium Thermotoga maritima . An overview of the proteases in these organisms is given based on those proteases that have been characterized and on putativemore » proteases that have been identified from genomic 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

  9. PLEUROCLADIA LACUSTRIS IN ARCTIC AMERICA(1).

    PubMed

    Wilce, R T

    1966-06-01

    Several large populations of Pletirocladia lacustris A. Br. were found at Devon Island, N.W.T., Canada, in an intermittently marine habitat. The morphology, cytology, and ecology of this species were described from living material from two habitats, the limestone and granite shores. The genus Kolderupia Lund ivas found synonymous with Pleurocladia; consequently Kolderupia maritima and K. lucifuga were lectotypified, characterized, and transferred to Pleurocladia. The genus Pleurocladia should be regarded as a member of the Ectocarpaceae until life history studies show a need for reclassification. In the Ectocarpaceae, Pleurocladia is probably most closely related to Protectocarpus Kuckuck. The distribution of P. lacustris indicated that the species, if not extremely rare, is uncommon.

  10. Which plant for which skin disease? Part 2: Dermatophytes, chronic venous insufficiency, photoprotection, actinic keratoses, vitiligo, hair loss, cosmetic indications.

    PubMed

    Reuter, Juliane; Wölfle, Ute; Korting, Hans Christian; Schempp, Christoph

    2010-11-01

    This paper continues our review of scientifically evaluated plant extracts in dermatology. After plants effective against dermatophytes, botanicals with anti-edema effects in chronic venous insufficiency are discussed. There is good evidence from randomized clinical studies that plant extracts from grape vine leaves (Vitis vinifera), horse chestnut (Aesculus hippocastanum), sea pine (Pinus maritima) and butcher's broom (Ruscus aculeatus) can reduce edema in chronic venous insufficiency. Plant extracts from witch hazel (Hamamelis virginiana), green tea (Camellia sinensis), the fern Polypodium leucotomos and others contain antioxidant polyphenolic compounds that may protect the skin from sunburn and photoaging when administered topically or systemically. Extracts from the garden spurge (Euphorbia peplus) and from birch bark (Betula alba) have been shown to be effective in the treatment of actinic keratoses in phase II studies. Some plant extracts have also been investigated in the treatment of vitiligo, various forms of hair loss and pigmentation disorders, and in aesthetic dermatology. PMID:20707877

  11. Acidophilic adaptations in the structure of Acetobacter aceti N5-carboxyaminoimidazole ribonucleotide mutase (PurE).

    PubMed

    Settembre, Ethan C; Chittuluru, Johnathan R; Mill, Christopher P; Kappock, T Joseph; Ealick, Steven E

    2004-10-01

    The crystal structure of Acetobacter aceti PurE was determined to a resolution of 1.55 A and is compared with the known structures of the class I PurEs from a mesophile, Escherichia coli, and a thermophile, Thermotoga maritima. Analyses of the general factors that increase protein stability are examined as potential explanations for the acid stability of A. aceti PurE. Increased inter-subunit hydrogen bonding and an increased number of arginine-containing salt bridges appear to account for the bulk of the increased acid stability. A chain of histidines linking two active sites is discussed in the context of the proton transfers catalyzed by the enzyme.

  12. In situ nitrogen generation removes wax from flowlines

    SciTech Connect

    Khalil, C.N.

    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.

  13. Intrinsic stability of Brassicaceae plasma membrane in relation to changes in proteins and lipids as a response to salinity.

    PubMed

    Chalbi, Najla; Martínez-Ballesta, Ma Carmen; Youssef, Nabil Ben; Carvajal, Micaela

    2015-03-01

    Changes in plasma membrane lipids, such as sterols and fatty acids, have been observed as a result of salt stress. These alterations, together with modification of the plasma membrane protein profile, confer changes in the physical properties of the membrane to be taken into account for biotechnological uses. In our experiments, the relationship between lipids and proteins in three different Brassicaceae species differing in salinity tolerance (Brassica oleracea, B. napus and Cakile maritima) and the final plasma membrane stability were studied. The observed changes in the sterol (mainly an increase in sitosterol) and fatty acid composition (increase in RUFA) in each species led to physical adaptation of the plasma membrane to salt stress. The in vitro vesicles stability was higher in the less tolerant (B. oleracea) plants together with low lipoxygenase activity. These results indicate that the proteins/lipids ratio and lipid composition is an important aspect to take into account for the use of natural vesicles in plant biotechnology. PMID:25544590

  14. 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.

  15. 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.

  16. A new cytoplasmic male sterile genotype in the sugar beet Beta vulgaris L.: a molecular analysis.

    PubMed

    Mann, V; McIntosh, L; Theurer, C; Hirschberg, J

    1989-08-01

    Mitochondrial DNA (mtDNA) from fertile (N) and possibly new cytoplasmic male sterile (CMS) genotypes was studied in the sugar beet Beta vulgaris L. It was found by restriction endonuclease analysis that BMC-CMS, a cytoplasm that was derived from the wild beet Beta maritima, contained a unique type of mtDNA which is distinguishable from both the N and S-CMS, the only other CMS genotype that is currently availabe in B. vulgaris L. The organization of three genes: coxI, coxII and cob, was analyzed by hybridization with heterologous probes from maize. These genes have a similar structure in N and BMC-CMS that is different from S-CMS. It is concluded that BMC-CMS is a novel CMS genotype in the sugar beet.

  17. DNA fingerprinting in sugar beet (Beta vulgaris) - identification of double-haploid breeding lines.

    PubMed

    Schmidt, T; Boblenz, K; Metzlaff, M; Kaemmer, D; Weising, K; Kahl, G

    1993-02-01

    The distribution and abundance of simple repetitive sequences complementary to the synthetic oligonucleotides (GACA)4, (GATA)4, (GTG)5 and (CA)8 in the genomes of several cultivars of Beta vulgaris and in the wild beet B. vulgaris ssp. maritima were investigated. Hybridization experiments revealed that all four motifs were present, though at different abundances, in the genomes of all of the investigated beet cultivars. Considerable intraspecific variation of the resulting DNA fingerprints was observed. The extent of polymorphism depends on the oligonucleotide probe. The most informative banding patterns were obtained with the (GATA)4 probe hybridized to HinfI-, HaeIII-, or RsaI-restricted DNA, respectively. DNA fingerprinting with (GATA)4 allowed a clear differentiation of double-haploid breeding lines (DH lines). We demonstrated that the application of oligonucleotide probes for DNA fingerprinting is a sensitive tool for genome diagnosis in cultivated beet.

  18. Comparison of chloroplast and mitochondrial DNA from five morphologically distinct Beta vulgaris cultivars: sugar beet, fodder beet, beet root, foliage beet, and Swiss chard.

    PubMed

    Ecke, W; Michaelis, G

    1990-04-01

    Two cytoplasms, N and S, are used in the breeding of sugar beet, Beta vulgaris var. altissima. These cytoplasms can be distinguished by their mitochondrial DNA. In an attempt to detect new cytoplasms, we compared the restriction profiles of chloroplast and mitochondrial DNA from five different cultivars of Beta vulgaris. All restriction patterns of chloroplast DNA were identical. With the exception of sugar beet with S-cytoplasm, all cultivars studied showed the same restriction profile of mitochondrial DNA, indicating that these cultivars all contain the N-cytoplasm. These results are discussed with regard to the large morphological differences of the cultivars and the cytoplasmic variability found in natural populations of the wild beet, Beta maritima.

  19. X-ray diffraction structure of a plant glycosyl hydrolase family 32 protein: fructan 1-exohydrolase IIa of Cichorium intybus.

    PubMed

    Verhaest, Maureen; Van den Ende, Wim; Roy, Katrien Le; De Ranter, Camiel J; Laere, André Van; Rabijns, Anja

    2005-02-01

    Fructan 1-exohydrolase, an enzyme involved in fructan degradation, belongs to the glycosyl hydrolase family 32. The structure of isoenzyme 1-FEH IIa from Cichorium intybus is described at a resolution of 2.35 A. The structure consists of an N-terminal fivefold beta-propeller domain connected to two C-terminal beta-sheets. The putative active site is located entirely in the beta-propeller domain and is formed by amino acids which are highly conserved within glycosyl hydrolase family 32. The fructan-binding site is thought to be in the cleft formed between the two domains. The 1-FEH IIa structure is compared with the structures of two homologous but functionally different enzymes: a levansucrase from Bacillus subtilis (glycosyl hydrolase family 68) and an invertase from Thermotoga maritima (glycosyl hydrolase family 32).

  20. Biochemical Characterization and Structural Analysis of a Bifunctional Cellulase/Xylanase from Clostridium thermocellum*

    PubMed Central

    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

    2015-01-01

    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

  1. Impacts of oil sands process water on fen plants: implications for plant selection in required reclamation projects.

    PubMed

    Pouliot, Rémy; Rochefort, Line; Graf, Martha D

    2012-08-01

    Fen plant growth in peat contaminated with groundwater discharges of oil sands process water (OSPW) was assessed in a greenhouse over two growing seasons. Three treatments (non-diluted OSPW, diluted OSPW and rainwater) were tested on five vascular plants and four mosses. All vascular plants tested can grow in salinity and naphthenic acids levels currently produced by oil sands activity in northwestern Canada. No stress sign was observed after both seasons. Because of plant characteristics, Carex species (C. atherodes and C. utriculata) and Triglochin maritima would be more useful for rapidly restoring vegetation and creating a new peat-accumulating system. Groundwater discharge of OSPW proved detrimental to mosses under dry conditions and ensuring adequate water levels would be crucial in fen creation following oil sands exploitation. Campylium stellatum would be the best choice to grow in contaminated areas and Bryum pseudotriquetrum might be interesting as it has spontaneously regenerated in all treatments.

  2. 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.

  3. Crystal Structure of the Lysine Riboswitch Regulatory mRNA Element*S⃞

    PubMed Central

    Garst, Andrew D.; Héroux, Annie; Rambo, Robert P.; Batey, Robert T.

    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 2.8Å 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. PMID:18593706

  4. Crystal structure of the lysine riboswitch regulatory mRNA element.

    PubMed

    Garst, Andrew D; Héroux, Annie; Rambo, Robert P; Batey, Robert T

    2008-08-15

    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 angstroms 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. PMID:18593706

  5. 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.

  6. The class III ribonucleotide reductase from Neisseria bacilliformis can utilize thioredoxin as a reductant

    PubMed Central

    Wei, Yifeng; Funk, Michael A.; Rosado, Leonardo A.; Baek, Jiyeon; Drennan, Catherine L.; Stubbe, JoAnne

    2014-01-01

    The class III anaerobic ribonucleotide reductases (RNRs) studied to date couple the reduction of ribonucleotides to deoxynucleotides with the oxidation of formate to CO2. Here we report the cloning and heterologous expression of the Neisseria bacilliformis class III RNR and show that it can catalyze nucleotide reduction using the ubiquitous thioredoxin/thioredoxin reductase/NADPH system. We present a structural model based on a crystal structure of the homologous Thermotoga maritima class III RNR, showing its architecture and the position of conserved residues in the active site. Phylogenetic studies suggest that this form of class III RNR is present in bacteria and archaea that carry out diverse types of anaerobic metabolism. PMID:25157154

  7. 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.

  8. Intrinsic stability of Brassicaceae plasma membrane in relation to changes in proteins and lipids as a response to salinity.

    PubMed

    Chalbi, Najla; Martínez-Ballesta, Ma Carmen; Youssef, Nabil Ben; Carvajal, Micaela

    2015-03-01

    Changes in plasma membrane lipids, such as sterols and fatty acids, have been observed as a result of salt stress. These alterations, together with modification of the plasma membrane protein profile, confer changes in the physical properties of the membrane to be taken into account for biotechnological uses. In our experiments, the relationship between lipids and proteins in three different Brassicaceae species differing in salinity tolerance (Brassica oleracea, B. napus and Cakile maritima) and the final plasma membrane stability were studied. The observed changes in the sterol (mainly an increase in sitosterol) and fatty acid composition (increase in RUFA) in each species led to physical adaptation of the plasma membrane to salt stress. The in vitro vesicles stability was higher in the less tolerant (B. oleracea) plants together with low lipoxygenase activity. These results indicate that the proteins/lipids ratio and lipid composition is an important aspect to take into account for the use of natural vesicles in plant biotechnology.

  9. Evaluation of phytotoxicity of seaport sediments aged artificially by rotary leaching in the framework of a quarry deposit scenario.

    PubMed

    Bedell, J-P; Ferro, Y; Bazin, C; Perrodin, Y

    2014-09-15

    In the framework of an ecological risk assessment of seaport sediments for terrestrial ecosystems when deposited in quarries, we simulated the "ageing" of sediments exposed to rain. This experiment highlighted an inflection point at the solid/liquid ratio 1/25, after which the extraction of pollutants increases moderately. The raw sediments studied inhibited the germination of Lolium perenne and Armeria maritima (a halophytic species) seeds. Furthermore, they affected the early development of L.perenne. The same sediments, leached at a ratio of 1/25, presented a reduction of acute (germination) and chronic (growth) phytotoxicity. The bioconcentration factors of the metals studied decreased with the leached sediment, except for Cu which was still clearly identified in root parts. Thus rotary leaching tests and phytotoxicity bioassays can be used to provide an initial assessment of the ability of plants, particularly halophytes, to colonize deposits of dredged seaport sediments.

  10. Feasibility of using hyperaccumulating plants to bioremediate metal-contaminated soil

    SciTech Connect

    Kelly, R.J.; Guerin, T.F.

    1995-12-31

    A feasibility study was carried out to determine whether selected plants were capable of hyperaccumulating anthropogenic sources of metals found in soils from three contaminated sites. A trial was conducted using the previously reported hyperaccumulators, Armeria maritima (thrift), Impatiens balsamina (balsam), Alyssum saxatile (gold dust), and the control species, Brassica oleracea (cabbage). Although none of these plants showed any substantial hyperaccumulation of Cu, Zn, Pb, and Cd, it was established that there is an optimum period in the life-cycle of these plants in which the metal concentration reaches a maximum. This period was dependent on the metal, soil, and plant type. The current paper describes the data obtained for Zn and Cu uptake by thrift.

  11. The Deinococcus-Thermus phylum and the effect of rRNA composition on phylogenetic tree construction

    NASA Technical Reports Server (NTRS)

    Weisburg, W. G.; Giovannoni, S. J.; Woese, C. R.

    1989-01-01

    Through comparative analysis of 16S ribosomal RNA sequences, it can be shown that two seemingly dissimilar types of eubacteria Deinococcus and the ubiquitous hot spring organism Thermus are distantly but specifically related to one another. This confirms an earlier report based upon 16S rRNA oligonucleotide cataloging studies (Hensel et al., 1986). Their two lineages form a distinctive grouping within the eubacteria that deserved the taxonomic status of a phylum. The (partial) sequence of T. aquaticus rRNA appears relatively close to those of other thermophilic eubacteria. e.g. Thermotoga maritima and Thermomicrobium roseum. However, this closeness does not reflect a true evolutionary closeness; rather it is due to a "thermophilic convergence", the result of unusually high G+C composition in the rRNAs of thermophilic bacteria. Unless such compositional biases are taken into account, the branching order and root of phylogenetic trees can be incorrectly inferred.

  12. Hybridization can facilitate species invasions, even without enhancing local adaptation.

    PubMed

    Mesgaran, Mohsen B; Lewis, Mark A; Ades, Peter K; Donohue, Kathleen; Ohadi, Sara; Li, Chengjun; Cousens, Roger D

    2016-09-01

    The founding population in most new species introductions, or at the leading edge of an ongoing invasion, is likely to be small. Severe Allee effects-reductions in individual fitness at low population density-may then result in a failure of the species to colonize, even if the habitat could support a much larger population. Using a simulation model for plant populations that incorporates demography, mating systems, quantitative genetics, and pollinators, we show that Allee effects can potentially be overcome by transient hybridization with a resident species or an earlier colonizer. This mechanism does not require the invocation of adaptive changes usually attributed to invasions following hybridization. We verify our result in a case study of sequential invasions by two plant species where the outcrosser Cakile maritima has replaced an earlier, inbreeding, colonizer Cakile edentula (Brassicaceae). Observed historical rates of replacement are consistent with model predictions from hybrid-alleviated Allee effects in outcrossers, although other causes cannot be ruled out.

  13. Food habits of mute swans in the Chesapeake Bay

    USGS Publications Warehouse

    Perry, M.C.; Osenton, P.C.; Lohnes, E.J.R.; Perry, Matthew C.

    2004-01-01

    Unlike the tundra swan (Cygnus columbianus) that migrate to the Bay for the winter, the mute swan (Cygnus olor) is a year long resident and therefore has raised concerns among research managers over reports of conflicts with nesting native water birds and the consumption of submerged aquatic vegetation (SAV). Although data on the reduction of SAV by nesting mute swans and their offspring during the spring and summer are limited, food-habits data show that mute swans rely heavily on SAV during these months. Analyses of the gullet and gizzard of mute swans indicate that widgeon grass (Ruppia maritima) and eelgrass (Zostera marina) were the most important food items to mute swans during the winter and spring. Other organisms were eaten by mute swans, but represent small percentages of food. Corn (Zea mays) fed to the swans by Bay residents in late winter probably supplements their limited vegetative food resources at that time of year.

  14. Conformational change of pseudouridine 55 synthase upon its association with RNA substrate.

    PubMed

    Phannachet, Kulwadee; Huang, Raven H

    2004-01-01

    Pseudouridine 55 synthase (Psi55S) catalyzes isomerization of uridine (U) to pseudouridine (Psi) at position 55 in transfer RNA. The crystal structures of Thermotoga maritima Psi55S, and its complex with RNA, have been determined at 2.9 and 3.0 A resolutions, respectively. Structural comparisons with other families of pseudouridine synthases (PsiS) indicate that Psi55S may acquire its ability to recognize a stem-loop RNA substrate by two insertions of polypeptides into the PsiS core. The structure of apo-Psi55S reveals that these two insertions interact with each other. However, association with RNA substrate induces substantial conformational change in one of the insertions, resulting in disruption of interaction between insertions and association of both insertions with the RNA substrate. Specific interactions between two insertions, as well as between the insertions and the RNA substrate, account for the molecular basis of the conformational change.

  15. Food habits and distribution of wintering canvasbacks, Aythya valisineria, on Chesapeake Bay

    USGS Publications Warehouse

    Perry, M.C.; Uhler, F.M.

    1988-01-01

    Baltic clams (Macoma balthica) were the predominant food items of 323 canvasbacks (Aythya valisineria) collected throughout Chesapeake Bay during 1970-1979. Natural vegetation constituted 4% of the food volume. Widgeongrass (Ruppia maritima) and redhead grass (Potamogeton perfoliatus) constituted the greatest percent volume and frequency of occurrence among the plant species, whereas wild celery (Vallisneria americana) constituted only a trace of the food volume. These results contrast with historical records of food habits of canvasbacks in Chesapeake Bay. Canvasback population estimates during the 1970?s were examined to detect annual and seasonal changes in distribution. Linear regression analyses of winter canvasback populations in the bay showed a significant decline in the upper-bay and middle-bay populations, but no significant changes in the lower-bay and Potomac River populations. The changes in winter distribution and abundance of the canvasback appear related to changes in natural food availability, which is the result of altered environmental conditions.

  16. In silico method for modelling metabolism and gene product expression at genome scale

    SciTech Connect

    Lerman, Joshua A.; Hyduke, Daniel R.; Latif, Haythem; Portnoy, Vasiliy A.; Lewis, Nathan E.; Orth, Jeffrey D.; Rutledge, Alexandra C.; Smith, Richard D.; Adkins, Joshua N.; Zengler, Karsten; Palsson, Bernard O.

    2012-07-03

    Transcription and translation use raw materials and energy generated metabolically to create the macromolecular machinery responsible for all cellular functions, including metabolism. A biochemically accurate model of molecular biology and metabolism will facilitate comprehensive and quantitative computations of an organism's molecular constitution as a function of genetic and environmental parameters. Here we formulate a model of metabolism and macromolecular expression. Prototyping it using the simple microorganism Thermotoga maritima, we show our model accurately simulates variations in cellular composition and gene expression. Moreover, through in silico comparative transcriptomics, the model allows the discovery of new regulons and improving the genome and transcription unit annotations. Our method presents a framework for investigating molecular biology and cellular physiology in silico and may allow quantitative interpretation of multi-omics data sets in the context of an integrated biochemical description of an organism.

  17. Structural insight into partner specificity and phosphoryl transfer in two-component signal transduction.

    PubMed

    Casino, Patricia; Rubio, Vicente; Marina, Alberto

    2009-10-16

    The chief mechanism used by bacteria for sensing their environment is based on two conserved proteins: a sensor histidine kinase (HK) and an effector response regulator (RR). The signal transduction process involves highly conserved domains of both proteins that mediate autokinase, phosphotransfer, and phosphatase activities whose output is a finely tuned RR phosphorylation level. Here, we report the structure of the complex between the entire cytoplasmic portion of Thermotoga maritima class I HK853 and its cognate, RR468, as well as the structure of the isolated RR468, both free and BeF(3)(-) bound. Our results provide insight into partner specificity in two-component systems, recognition of the phosphorylation state of each partner, and the catalytic mechanism of the phosphatase reaction. Biochemical analysis shows that the HK853-catalyzed autokinase reaction proceeds by a cis autophosphorylation mechanism within the HK subunit. The results suggest a model for the signal transduction mechanism in two-component systems.

  18. 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

  19. 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

  20. 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.

  1. A comparative study of the early osmotic, ionic, redox and hormonal signaling response in leaves and roots of two halophytes and a glycophyte to salinity.

    PubMed

    Ellouzi, Hasna; Ben Hamed, Karim; Hernández, Iker; Cela, Jana; Müller, Maren; Magné, Christian; Abdelly, Chedly; Munné-Bosch, Sergi

    2014-12-01

    Salt stress is one of the most important abiotic stress factors affecting plant growth and productivity in natural ecosystems. In this study, we aimed at determining possible differences between salt tolerant and salt sensitive species in early (within 72 h) salt stress response in leaves and roots. To this purpose, we subjected three Brassicaceae species, namely two halophytes-Cakile maritima and Thellungiella salsuginea--and a glycophyte--Arabidopsis thaliana- to short-term salt stress (400 mM NaCl). The results indicate that the halophytes showed a differential osmotic and ionic response together with an early and transient oxidative burst, which was characterized by enhanced hydrogen peroxide levels and subsequent activation of antioxidant defenses in both leaves and roots. In addition, the halophytes displayed enhanced accumulation of abscisic acid, jasmonic acid (JA) and ACC (aminocyclopropane-1-carboxylic acid, the precursor of ethylene) in leaves and roots, as compared to A. thaliana under salt stress. Moreover, the halophytes showed enhanced expression of ethylene response factor1 (ERF1), the convergence node of the JA and ethylene signaling pathways in both leaves and roots upon exposure to salt stress. In conclusion, we show that the halophytes C. maritima and T. salsuginea experience an early oxidative burst, improved antioxidant defenses and hormonal response not only in leaves but also in roots, in comparison to the glycophyte A. thaliana. This differential signaling response converging, at least in part, into increased ERF1 expression in both above- and underground tissues seems to underlay, at least in part, the enhanced tolerance of the two studied halophytes to salt stress. PMID:25156490

  2. Ligand-induced conformational changes in a thermophilic ribose-binding protein

    SciTech Connect

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

    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

  3. Functional analysis of centipede development supports roles for Wnt genes in posterior development and segment generation.

    PubMed

    Hayden, Luke; Schlosser, Gerhard; Arthur, Wallace

    2015-01-01

    The genes of the Wnt family play important and highly conserved roles in posterior growth and development in a wide range of animal taxa. Wnt genes also operate in arthropod segmentation, and there has been much recent debate regarding the relationship between arthropod and vertebrate segmentation mechanisms. Due to its phylogenetic position, body form, and possession of many (11) Wnt genes, the centipede Strigamia maritima is a useful system with which to examine these issues. This study takes a functional approach based on treatment with lithium chloride, which causes ubiquitous activation of canonical Wnt signalling. This is the first functional developmental study performed in any of the 15,000 species of the arthropod subphylum Myriapoda. The expression of all 11 Wnt genes in Strigamia was analyzed in relation to posterior development. Three of these genes, Wnt11, Wnt5, and WntA, were strongly expressed in the posterior region and, thus, may play important roles in posterior developmental processes. In support of this hypothesis, LiCl treatment of S. maritima embryos was observed to produce posterior developmental defects and perturbations in AbdB and Delta expression. The effects of LiCl differ depending on the developmental stage treated, with more severe effects elicited by treatment during germband formation than by treatment at later stages. These results support a role for Wnt signalling in conferring posterior identity in Strigamia. In addition, data from this study are consistent with the hypothesis of segmentation based on a "clock and wavefront" mechanism operating in this species.

  4. Role of magnesium ions in the reaction mechanism at the interface between Tm1631 protein and its DNA ligand.

    PubMed

    Ogrizek, Mitja; Konc, Janez; Bren, Urban; Hodošček, Milan; Janežič, Dušanka

    2016-01-01

    A protein, Tm1631 from the hyperthermophilic organism Thermotoga maritima belongs to a domain of unknown function protein family. It was predicted that Tm1631 binds with the DNA and that the Tm1631-DNA complex is an endonuclease repair system with a DNA repair function (Konc et al. PLoS Comput Biol 9(11): e1003341, 2013). We observed that the severely bent, strained DNA binds to the protein for the entire 90 ns of classical molecular dynamics (MD) performed; we could observe no significant changes in the most distorted region of the DNA, where the cleavage of phosphodiester bond occurs. In this article, we modeled the reaction mechanism at the interface between Tm1631 and its proposed ligand, the DNA molecule, focusing on cleavage of the phosphodiester bond. After addition of two Mg(2+) ions to the reaction center and extension of classical MD by 50 ns (totaling 140 ns), the DNA ligand stayed bolted to the protein. Results from density functional theory quantum mechanics/molecular mechanics (QM/MM) calculations suggest that the reaction is analogous to known endonuclease mechanisms: an enzyme reaction mechanism with two Mg(2+) ions in the reaction center and a pentacovalent intermediate. The minimum energy pathway profile shows that the phosphodiester bond cleavage step of the reaction is kinetically controlled and not thermodynamically because of a lack of any energy barrier above the accuracy of the energy profile calculation. The role of ions is shown by comparing the results with the reaction mechanisms in the absence of the Mg(2+) ions where there is a significantly higher reaction barrier than in the presence of the Mg(2+) ions.Graphical abstractA protein, Tm1631 from the hyperthermophilic organism Thermotoga maritima belongs to a domain of unknown function protein family. We modeled the reaction mechanism at the interface between Tm1631 and its proposed ligand, the DNA molecule, focusing on cleavage of the phosphodiester bond.

  5. Functional analysis of centipede development supports roles for Wnt genes in posterior development and segment generation.

    PubMed

    Hayden, Luke; Schlosser, Gerhard; Arthur, Wallace

    2015-01-01

    The genes of the Wnt family play important and highly conserved roles in posterior growth and development in a wide range of animal taxa. Wnt genes also operate in arthropod segmentation, and there has been much recent debate regarding the relationship between arthropod and vertebrate segmentation mechanisms. Due to its phylogenetic position, body form, and possession of many (11) Wnt genes, the centipede Strigamia maritima is a useful system with which to examine these issues. This study takes a functional approach based on treatment with lithium chloride, which causes ubiquitous activation of canonical Wnt signalling. This is the first functional developmental study performed in any of the 15,000 species of the arthropod subphylum Myriapoda. The expression of all 11 Wnt genes in Strigamia was analyzed in relation to posterior development. Three of these genes, Wnt11, Wnt5, and WntA, were strongly expressed in the posterior region and, thus, may play important roles in posterior developmental processes. In support of this hypothesis, LiCl treatment of S. maritima embryos was observed to produce posterior developmental defects and perturbations in AbdB and Delta expression. The effects of LiCl differ depending on the developmental stage treated, with more severe effects elicited by treatment during germband formation than by treatment at later stages. These results support a role for Wnt signalling in conferring posterior identity in Strigamia. In addition, data from this study are consistent with the hypothesis of segmentation based on a "clock and wavefront" mechanism operating in this species. PMID:25627713

  6. Structure of the ribosomal interacting GTPase YjeQ from the enterobacterial species Salmonella typhimurium

    SciTech Connect

    Nichols, C. E.; Johnson, C.; Lamb, H. K.; Lockyer, M.; Charles, I. G.; Hawkins, A. R.; Stammers, D. K.

    2007-11-01

    The X-ray crystal structure of the GTPase YjeQ from S. typhimurium is presented and compared with those of orthologues from T. maritima and B. subtilis. The YjeQ class of P-loop GTPases assist in ribosome biogenesis and also bind to the 30S subunit of mature ribosomes. YjeQ ribosomal binding is GTP-dependent and thought to specifically direct protein synthesis, although the nature of the upstream signal causing this event in vivo is as yet unknown. The attenuating effect of YjeQ mutants on bacterial growth in Escherichia coli makes it a potential target for novel antimicrobial agents. In order to further explore the structure and function of YjeQ, the isolation, crystallization and structure determination of YjeQ from the enterobacterial species Salmonella typhimurium (StYjeQ) is reported. Whilst the overall StYjeQ fold is similar to those of the previously reported Thematoga maritima and Bacillus subtilis orthologues, particularly the GTPase domain, there are larger differences in the three OB folds. Although the zinc-finger secondary structure is conserved, significant sequence differences alter the nature of the external surface in each case and may reflect varying signalling pathways. Therefore, it may be easier to develop YjeQ-specific inhibitors that target the N- and C-terminal regions, disrupting the metabolic connectivity rather than the GTPase activity. The availability of coordinates for StYjeQ will provide a significantly improved basis for threading Gram-negative orthologue sequences and in silico compound-screening studies, with the potential for the development of species-selective drugs.

  7. Dissecting the roles of a strictly conserved tyrosine in substrate recognition and catalysis by pseudouridine 55 synthase.

    PubMed

    Phannachet, Kulwadee; Elias, Youssef; Huang, Raven H

    2005-11-29

    Sequence alignment of the TruA, TruB, RsuA, and RluA families of pseudouridine synthases (PsiS) identifies a strictly conserved aspartic acid, which has been shown to be the critical nucleophile for the PsiS-catalyzed formation of pseudouridine (Psi). However, superposition of the representative structures from these four families of enzymes identifies two additional amino acids, a lysine or an arginine (K/R) and a tyrosine (Y), from a K/RxY motif that are structurally conserved in the active site. We have created a series of Thermotoga maritima and Escherichia coli pseudouridine 55 synthase (Psi55S) mutants in which the conserved Y is mutated to other amino acids. A new crystal structure of the T. maritima Psi55S Y67F mutant in complex with a 5FU-RNA at 2.4 A resolution revealed formation of 5-fluoro-6-hydroxypseudouridine (5FhPsi), the same product previously seen in wild-type Psi55S-5FU-RNA complex structures. HPLC analysis confirmed efficient formation of 5FhPsi by both Psi55S Y67F and Y67L mutants but to a much lesser extent by the Y67A mutant when 5FU-RNA substrate was used. However, both HPLC analysis and a tritium release assay indicated that these mutants had no detectable enzymatic activity when the natural RNA substrate was used. The combined structural and mutational studies lead us to propose that the side chain of the conserved tyrosine in these four families of PsiS plays a dual role within the active site, maintaining the structural integrity of the active site through its hydrophobic phenyl ring and acting as a general base through its OH group for the proton abstraction required in the last step of PsiS-catalyzed formation of Psi.

  8. Physics-based protein-structure prediction using a hierarchical protocol based on the UNRES force field: assessment in two blind tests.

    PubMed

    Ołdziej, S; Czaplewski, C; Liwo, A; Chinchio, M; Nanias, M; Vila, J A; Khalili, M; Arnautova, Y A; Jagielska, A; Makowski, M; Schafroth, H D; Kaźmierkiewicz, R; Ripoll, D R; Pillardy, J; Saunders, J A; Kang, Y K; Gibson, K D; Scheraga, H A

    2005-05-24

    Recent improvements in the protein-structure prediction method developed in our laboratory, based on the thermodynamic hypothesis, are described. The conformational space is searched extensively at the united-residue level by using our physics-based UNRES energy function and the conformational space annealing method of global optimization. The lowest-energy coarse-grained structures are then converted to an all-atom representation and energy-minimized with the ECEPP/3 force field. The procedure was assessed in two recent blind tests of protein-structure prediction. During the first blind test, we predicted large fragments of alpha and alpha+beta proteins [60-70 residues with C(alpha) rms deviation (rmsd) <6 A]. However, for alpha+beta proteins, significant topological errors occurred despite low rmsd values. In the second exercise, we predicted whole structures of five proteins (two alpha and three alpha+beta, with sizes of 53-235 residues) with remarkably good accuracy. In particular, for the genomic target TM0487 (a 102-residue alpha+beta protein from Thermotoga maritima), we predicted the complete, topologically correct structure with 7.3-A C(alpha) rmsd. So far this protein is the largest alpha+beta protein predicted based solely on the amino acid sequence and a physics-based potential-energy function and search procedure. For target T0198, a phosphate transport system regulator PhoU from T. maritima (a 235-residue mainly alpha-helical protein), we predicted the topology of the whole six-helix bundle correctly within 8 A rmsd, except the 32 C-terminal residues, most of which form a beta-hairpin. These and other examples described in this work demonstrate significant progress in physics-based protein-structure prediction.

  9. Physics-based protein-structure prediction using a hierarchical protocol based on the UNRES force field: Assessment in two blind tests

    PubMed Central

    Ołdziej, S.; Czaplewski, C.; Liwo, A.; Chinchio, M.; Nanias, M.; Vila, J. A.; Khalili, M.; Arnautova, Y. A.; Jagielska, A.; Makowski, M.; Schafroth, H. D.; Kaźmierkiewicz, R.; Ripoll, D. R.; Pillardy, J.; Saunders, J. A.; Kang, Y. K.; Gibson, K. D.; Scheraga, H. A.

    2005-01-01

    Recent improvements in the protein-structure prediction method developed in our laboratory, based on the thermodynamic hypothesis, are described. The conformational space is searched extensively at the united-residue level by using our physics-based UNRES energy function and the conformational space annealing method of global optimization. The lowest-energy coarse-grained structures are then converted to an all-atom representation and energy-minimized with the ECEPP/3 force field. The procedure was assessed in two recent blind tests of protein-structure prediction. During the first blind test, we predicted large fragments of α and α+β proteins [60–70 residues with Cα rms deviation (rmsd) <6 Å]. However, for α+β proteins, significant topological errors occurred despite low rmsd values. In the second exercise, we predicted whole structures of five proteins (two α and three α+β, with sizes of 53–235 residues) with remarkably good accuracy. In particular, for the genomic target TM0487 (a 102-residue α+β protein from Thermotoga maritima), we predicted the complete, topologically correct structure with 7.3-Å Cα rmsd. So far this protein is the largest α+β protein predicted based solely on the amino acid sequence and a physics-based potential-energy function and search procedure. For target T0198, a phosphate transport system regulator PhoU from T. maritima (a 235-residue mainly α-helical protein), we predicted the topology of the whole six-helix bundle correctly within 8 Å rmsd, except the 32 C-terminal residues, most of which form a β-hairpin. These and other examples described in this work demonstrate significant progress in physics-based protein-structure prediction. PMID:15894609

  10. Non-complexed four cascade enzyme mixture: simple purification and synergetic co-stabilization.

    PubMed

    Myung, Suwan; Zhang, Y-H Percival

    2013-01-01

    Cell-free biosystems comprised of synthetic enzymatic pathways would be a promising biomanufacturing platform due to several advantages, such as high product yield, fast reaction rate, easy control and access, and so on. However, it was essential to produce (purified) enzymes at low costs and stabilize them for a long time so to decrease biocatalyst costs. We studied the stability of the four recombinant enzyme mixtures, all of which originated from thermophilic microorganisms: triosephosphate isomerase (TIM) from Thermus thermophiles, fructose bisphosphate aldolase (ALD) from Thermotoga maritima, fructose bisphosphatase (FBP) from T. maritima, and phosphoglucose isomerase (PGI) from Clostridium thermocellum. It was found that TIM and ALD were very stable at evaluated temperature so that they were purified by heat precipitation followed by gradient ammonia sulfate precipitation. In contrast, PGI was not stable enough for heat treatment. In addition, the stability of a low concentration PGI was enhanced by more than 25 times in the presence of 20 mg/L bovine serum albumin or the other three enzymes. At a practical enzyme loading of 1000 U/L for each enzyme, the half-life time of free PGI was prolong to 433 h in the presence of the other three enzymes, resulting in a great increase in the total turn-over number of PGI to 6.2×10(9) mole of product per mole of enzyme. This study clearly suggested that the presence of other proteins had a strong synergetic effect on the stabilization of the thermolabile enzyme PGI due to in vitro macromolecular crowding effect. Also, this result could be used to explain why not all enzymes isolated from thermophilic microorganisms are stable in vitro because of a lack of the macromolecular crowding environment.

  11. Transportable data from non-target arthropod field studies for the environmental risk assessment of genetically modified maize expressing an insecticidal double-stranded RNA.

    PubMed

    Ahmad, Aqeel; Negri, Ignacio; Oliveira, Wladecir; Brown, Christopher; Asiimwe, Peter; Sammons, Bernard; Horak, Michael; Jiang, Changjian; Carson, David

    2016-02-01

    As part of an environmental risk assessment, the potential impact of genetically modified (GM) maize MON 87411 on non-target arthropods (NTAs) was evaluated in the field. MON 87411 confers resistance to corn rootworm (CRW; Diabrotica spp.) by expressing an insecticidal double-stranded RNA (dsRNA) transcript and the Cry3Bb1 protein and tolerance to the herbicide glyphosate by producing the CP4 EPSPS protein. Field trials were conducted at 14 sites providing high geographic and environmental diversity within maize production areas from three geographic regions including the U.S., Argentina, and Brazil. MON 87411, the conventional control, and four commercial conventional reference hybrids were evaluated for NTA abundance and damage. Twenty arthropod taxa met minimum abundance criteria for valid statistical analysis. Nine of these taxa occurred in at least two of the three regions and in at least four sites across regions. These nine taxa included: aphid, predatory earwig, lacewing, ladybird beetle, leafhopper, minute pirate bug, parasitic wasp, sap beetle, and spider. In addition to wide regional distribution, these taxa encompass the ecological functions of herbivores, predators and parasitoids in maize agro-ecosystems. Thus, the nine arthropods may serve as representative taxa of maize agro-ecosystems, and thereby support that analysis of relevant data generated in one region can be transportable for the risk assessment of the same or similar GM crop products in another region. Across the 20 taxa analyzed, no statistically significant differences in abundance were detected between MON 87411 and the conventional control for 123 of the 128 individual-site comparisons (96.1%). For the nine widely distributed taxa, no statistically significant differences in abundance were detected between MON 87411 and the conventional control. Furthermore, no statistically significant differences were detected between MON 87411 and the conventional control for 53 out of 56 individual

  12. Transportable data from non-target arthropod field studies for the environmental risk assessment of genetically modified maize expressing an insecticidal double-stranded RNA.

    PubMed

    Ahmad, Aqeel; Negri, Ignacio; Oliveira, Wladecir; Brown, Christopher; Asiimwe, Peter; Sammons, Bernard; Horak, Michael; Jiang, Changjian; Carson, David

    2016-02-01

    As part of an environmental risk assessment, the potential impact of genetically modified (GM) maize MON 87411 on non-target arthropods (NTAs) was evaluated in the field. MON 87411 confers resistance to corn rootworm (CRW; Diabrotica spp.) by expressing an insecticidal double-stranded RNA (dsRNA) transcript and the Cry3Bb1 protein and tolerance to the herbicide glyphosate by producing the CP4 EPSPS protein. Field trials were conducted at 14 sites providing high geographic and environmental diversity within maize production areas from three geographic regions including the U.S., Argentina, and Brazil. MON 87411, the conventional control, and four commercial conventional reference hybrids were evaluated for NTA abundance and damage. Twenty arthropod taxa met minimum abundance criteria for valid statistical analysis. Nine of these taxa occurred in at least two of the three regions and in at least four sites across regions. These nine taxa included: aphid, predatory earwig, lacewing, ladybird beetle, leafhopper, minute pirate bug, parasitic wasp, sap beetle, and spider. In addition to wide regional distribution, these taxa encompass the ecological functions of herbivores, predators and parasitoids in maize agro-ecosystems. Thus, the nine arthropods may serve as representative taxa of maize agro-ecosystems, and thereby support that analysis of relevant data generated in one region can be transportable for the risk assessment of the same or similar GM crop products in another region. Across the 20 taxa analyzed, no statistically significant differences in abundance were detected between MON 87411 and the conventional control for 123 of the 128 individual-site comparisons (96.1%). For the nine widely distributed taxa, no statistically significant differences in abundance were detected between MON 87411 and the conventional control. Furthermore, no statistically significant differences were detected between MON 87411 and the conventional control for 53 out of 56 individual

  13. 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

  14. 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

  15. Structural Insights into the Mechanism of the PLP Synthase Holoenzyme from Thermotoga maritima†,‡

    PubMed Central

    Zein, Fairuz; Zhang, Yan; Kang, You-Na; Burns, Kristin; Begley, Tadhg P.; Ealick, Steven E.

    2008-01-01

    Pyridoxal 5'-phosphate (PLP) is the biologically active form of vitamin B6 and is an important cofactor for several of the enzymes involved in the metabolism of amine-containing natural products such as amino acids and amino-sugars. The PLP synthase holoenzyme consists of two subunits: YaaD catalyzes the condensation of ribulose 5-phosphate, glyceraldehyde-3-phosphate and ammonia and YaaE catalyzes the production of ammonia from glutamine. Here we describe the structure of the PLP synthase complex (YaaD-YaaE) from Thermotoga maritima at 2.9 Å resolution. This complex consists of a core of 12 YaaD monomers with 12 noninteracting YaaE monomers attached to the core. Compared to the previously published structure of PdxS (a YaaD ortholog in Geobacillus stearothermophilus), the N-terminus (1–18), which includes helix α0, the β2-α2 loop(46–56), which includes new helix α2a, and the C-terminus (270–280) of YaaD, are ordered in the complex but disordered in PdxS. A ribulose 5-phosphate is bound to YaaD via an imine with Lys82. Previous studies have demonstrated a similar imine at Lys149 and not at Lys81 (equivalent to Lys150 and 82 in T. maritima) for the Bacillus subtilis enzyme suggesting the possibility that two separate sites on YaaD are involved in PLP formation. A phosphate from the crystallization solution is found bound to YaaD and also serves as a marker for a possible second active site. An ammonia channel that connects the active site of YaaE with the ribulose 5-phosphate binding site was identified. This channel is similar to one found in imidazole glycerol phosphate synthase; however, when the β-barrels of the two complexes are superimposed, the glutaminase domains are rotated by about 180° with respect to each other. PMID:17144654

  16. 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

  17. Role of magnesium ions in the reaction mechanism at the interface between Tm1631 protein and its DNA ligand.

    PubMed

    Ogrizek, Mitja; Konc, Janez; Bren, Urban; Hodošček, Milan; Janežič, Dušanka

    2016-01-01

    A protein, Tm1631 from the hyperthermophilic organism Thermotoga maritima belongs to a domain of unknown function protein family. It was predicted that Tm1631 binds with the DNA and that the Tm1631-DNA complex is an endonuclease repair system with a DNA repair function (Konc et al. PLoS Comput Biol 9(11): e1003341, 2013). We observed that the severely bent, strained DNA binds to the protein for the entire 90 ns of classical molecular dynamics (MD) performed; we could observe no significant changes in the most distorted region of the DNA, where the cleavage of phosphodiester bond occurs. In this article, we modeled the reaction mechanism at the interface between Tm1631 and its proposed ligand, the DNA molecule, focusing on cleavage of the phosphodiester bond. After addition of two Mg(2+) ions to the reaction center and extension of classical MD by 50 ns (totaling 140 ns), the DNA ligand stayed bolted to the protein. Results from density functional theory quantum mechanics/molecular mechanics (QM/MM) calculations suggest that the reaction is analogous to known endonuclease mechanisms: an enzyme reaction mechanism with two Mg(2+) ions in the reaction center and a pentacovalent intermediate. The minimum energy pathway profile shows that the phosphodiester bond cleavage step of the reaction is kinetically controlled and not thermodynamically because of a lack of any energy barrier above the accuracy of the energy profile calculation. The role of ions is shown by comparing the results with the reaction mechanisms in the absence of the Mg(2+) ions where there is a significantly higher reaction barrier than in the presence of the Mg(2+) ions.Graphical abstractA protein, Tm1631 from the hyperthermophilic organism Thermotoga maritima belongs to a domain of unknown function protein family. We modeled the reaction mechanism at the interface between Tm1631 and its proposed ligand, the DNA molecule, focusing on cleavage of the phosphodiester bond. PMID:27398092

  18. New crystal forms of Diocleinae lectins in the presence of different dimannosides

    SciTech Connect

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

    2006-11-01

    The crystallization and preliminary X-ray data of Canavalia gladiata lectin (CGL) and C. maritima lectin (CML) complexed with Man(α1-2)Man(α1)OMe, Man(α1-3)Man(α1)OMe and Man(α1-4)Man(α1)OMe in two crystal forms [the complexes with Man(α1-3)Man(α1)OMe and Man(α1-4)Man(α1)OMe crystallized in space group P3{sub 2} and those with Man(α1-2)Man(α1)OMe crystallized in space group I222], which differed from those of the native proteins (P2{sub 1}2{sub 1}2 for CML and C222 for CGL), are reported. 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(α1-2)Man(α1)OMe, Man(α1-3)Man(α1)OMe and Man(α1-4)Man(α1)OMe in two crystal forms [the complexes with Man(α1-3)Man(α1)OMe and Man(α1-4)Man(α1)OMe crystallized in space group P3{sub 2} and those with Man(α1-2)Man(α1)OMe crystallized in space group I222], which differed from those of the native proteins (P2{sub 1}2{sub 1}2 for CML and C222 for CGL), are reported. The crystal complexes of ConA-like lectins with Man(α1-4)Man(α1)OMe are reported here for the first time.

  19. 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 μg/ml and 0.1-0.9 μg/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

  20. 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

  1. Tidal events and salt-marsh structure influence black mangrove (Avicennia germinans) recruitment across an ecotone.

    PubMed

    Peterson, Jennifer M; Bell, Susan S

    2012-07-01

    Field experiments were conducted at a black mangrove-salt-marsh ecotone in southwest Florida (U.S.A.) to investigate retention of propagules of the black mangrove, Avicennia germinans, by salt-marsh plants as a mechanism of facilitation operating on recruitment success at landward boundaries. Buoyant A. germinans propagules are dispersed by tides, and stranding is required for establishment; therefore, processes that enable stranding should facilitate mangrove recruitment. We expected the physical structure of salt-marsh vegetation to define propagule retention capacity, and we predicted that salt-marsh plants with distinct growth forms would differentially retain propagules. Experimental monoculture plots (1 m2) of salt-marsh plants with different growth forms (Sporobolus virginicus [grass], Sesuvium portulacastrum [succulent forb], and Batis maritima [succulent scrub]) were created, and A. germinans propagules were emplaced into these plots and monitored over time. For comparison, propagules were also placed into natural polyculture plots (1 m2). Polyculture plots contained at least two of the salt-marsh plant taxa selected for monoculture treatments, and S. virginicus was always present within these polyculture plots. Natural polyculture plots retained 59.3% +/- 11.0% (mean +/- SE) of emplaced propagules. Monocultures varied in their propagule retention capacities with plots of S. virginicus retaining on average 65.7% +/- 11.5% of transplanted propagules compared to 7.2% +/- 1.8% by B. maritima and 5.0% +/- 1.9% by S. portulacastrum. Plots containing S. virginicus retained a significantly greater percentage of emplaced propagules relative to the two succulent salt-marsh taxa. Furthermore, propagule entrapment, across all treatments, was strongly correlated with salt-marsh structure (r2 = 0.6253, P = 0.00001), which was estimated using an indirect quantitative metric (lateral obstruction) calculated from digital images of plots. Overall, our findings imply that

  2. Experimental observations on sediment resuspension within submerged model canopies under oscillatory flow

    NASA Astrophysics Data System (ADS)

    Ros, Àlex; Colomer, Jordi; Serra, Teresa; Pujol, Dolors; Soler, Marianna; Casamitjana, Xavier

    2014-12-01

    A set of laboratory experiments were conducted to study the effect of submerged aquatic vegetation in sediment resuspension under progressive waves. Three vegetation models (rigid, flexible and real plants of Ruppia maritima), six wave frequencies (in the range F=0.6-1.6 Hz) and four plant densities (Solid Plant Fractions, SPF in the range of 1-10%) were used. The sediment bed properties corresponded to a salt marsh wetland with a bimodal particle size distribution with two particle populations (population 1: particle diameters in the range of 2.5 to 6.0 μm, and population 2: particle diameters in the range of 6.0 to 100 μm). Within the canopy, wave velocities were attenuated for all the canopies studied and for all the frequencies analyzed. The change in the TKE (ΔTKE) compared with the case without plants was studied. For the rigid canopy model, in comparison to the unimpeded experiment, an increase in ΔTKE inside the canopy for smaller frequencies (F=0.6-1.2 Hz) was observed together with stem Reynolds numbers Rep above 250. As a result, sediment resuspension for both sediment populations was higher than that of the unimpeded experiment. However, at higher frequencies (F=1.4 and 1.6 Hz) and higher plant densities (SPF=5%, 7.5% and 10%), the ΔTKE inside the canopy decreased, coinciding with stem Reynolds number Rep below 250. As a result, sediment resuspension for larger canopy densities and larger frequencies was reduced. For the flexible vegetation model, in comparison with the unimpeded experiment, a reduction in the ΔTKE inside the canopy was nearly always found. Resuspended sediment concentrations were found to decrease as flexible canopy densities increased. For the flexible vegetation the stem Reynolds number was Rep<250 and no production of ΔTKE was observed. The real case of a canopy of R. maritima behaved similarly to the flexible model canopy.

  3. 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 μg/ml and 0.1-0.9 μg/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

  4. Hybridization can facilitate species invasions, even without enhancing local adaptation.

    PubMed

    Mesgaran, Mohsen B; Lewis, Mark A; Ades, Peter K; Donohue, Kathleen; Ohadi, Sara; Li, Chengjun; Cousens, Roger D

    2016-09-01

    The founding population in most new species introductions, or at the leading edge of an ongoing invasion, is likely to be small. Severe Allee effects-reductions in individual fitness at low population density-may then result in a failure of the species to colonize, even if the habitat could support a much larger population. Using a simulation model for plant populations that incorporates demography, mating systems, quantitative genetics, and pollinators, we show that Allee effects can potentially be overcome by transient hybridization with a resident species or an earlier colonizer. This mechanism does not require the invocation of adaptive changes usually attributed to invasions following hybridization. We verify our result in a case study of sequential invasions by two plant species where the outcrosser Cakile maritima has replaced an earlier, inbreeding, colonizer Cakile edentula (Brassicaceae). Observed historical rates of replacement are consistent with model predictions from hybrid-alleviated Allee effects in outcrossers, although other causes cannot be ruled out. PMID:27601582

  5. A Robust and Versatile Method of Combinatorial Chemical Synthesis of Gene Libraries via Hierarchical Assembly of Partially Randomized Modules.

    PubMed

    Popova, Blagovesta; Schubert, Steffen; Bulla, Ingo; Buchwald, Daniela; Kramer, Wilfried

    2015-01-01

    A major challenge in gene library generation is to guarantee a large functional size and diversity that significantly increases the chances of selecting different functional protein variants. The use of trinucleotides mixtures for controlled randomization results in superior library diversity and offers the ability to specify the type and distribution of the amino acids at each position. Here we describe the generation of a high diversity gene library using tHisF of the hyperthermophile Thermotoga maritima as a scaffold. Combining various rational criteria with contingency, we targeted 26 selected codons of the thisF gene sequence for randomization at a controlled level. We have developed a novel method of creating full-length gene libraries by combinatorial assembly of smaller sub-libraries. Full-length libraries of high diversity can easily be assembled on demand from smaller and much less diverse sub-libraries, which circumvent the notoriously troublesome long-term archivation and repeated proliferation of high diversity ensembles of phages or plasmids. We developed a generally applicable software tool for sequence analysis of mutated gene sequences that provides efficient assistance for analysis of library diversity. Finally, practical utility of the library was demonstrated in principle by assessment of the conformational stability of library members and isolating protein variants with HisF activity from it. Our approach integrates a number of features of nucleic acids synthetic chemistry, biochemistry and molecular genetics to a coherent, flexible and robust method of combinatorial gene synthesis.

  6. 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.

  7. Weighted Implementation of Suboptimal Paths (WISP): An Optimized Algorithm and Tool for Dynamical Network Analysis.

    PubMed

    Van Wart, Adam T; Durrant, Jacob; Votapka, Lane; Amaro, Rommie E

    2014-02-11

    Allostery can occur by way of subtle cooperation among protein residues (e.g., amino acids) even in the absence of large conformational shifts. Dynamical network analysis has been used to model this cooperation, helping to computationally explain how binding to an allosteric site can impact the behavior of a primary site many ångstroms away. Traditionally, computational efforts have focused on the most optimal path of correlated motions leading from the allosteric to the primary active site. We present a program called Weighted Implementation of Suboptimal Paths (WISP) capable of rapidly identifying additional suboptimal pathways that may also play important roles in the transmission of allosteric signals. Aside from providing signal redundancy, suboptimal paths traverse residues that, if disrupted through pharmacological or mutational means, could modulate the allosteric regulation of important drug targets. To demonstrate the utility of our program, we present a case study describing the allostery of HisH-HisF, an amidotransferase from T. maritima thermotiga. WISP and its VMD-based graphical user interface (GUI) can be downloaded from http://nbcr.ucsd.edu/wisp.

  8. Recognition of the Helical Structure of β-1,4-Galactan by a New Family of Carbohydrate-binding Modules*

    PubMed Central

    Cid, Melissa; Pedersen, Henriette Lodberg; Kaneko, Satoshi; Coutinho, Pedro M.; Henrissat, Bernard; Willats, William G. T.; Boraston, Alisdair B.

    2010-01-01

    The microbial enzymes that depolymerize plant cell wall polysaccharides, ultimately promoting energy liberation and carbon recycling, are typically complex in their modularity and often contain carbohydrate-binding modules (CBMs). Here, through analysis of an unknown module from a Thermotoga maritima endo-β-1,4-galactanase, we identify a new family of CBMs that are most frequently found appended to proteins with β-1,4-galactanase activity. Polysaccharide microarray screening, immunofluorescence microscopy, and biochemical analysis of the isolated module demonstrate the specificity of the module, here called TmCBM61, for β-1,4-linked galactose-containing ligands, making it the founding member of family CBM61. The ultra-high resolution x-ray crystal structures of TmCBM61 (0.95 and 1.4 Å resolution) in complex with β-1,4-galactotriose reveal the molecular basis of the specificity of the CBM for β-1,4-galactan. Analysis of these structures provides insight into the recognition of an unexpected helical galactan conformation through a mode of binding that resembles the recognition of starch. PMID:20826814

  9. 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.

  10. Reconstruction of the Chemotaxis Receptor-Kinase Assembly

    SciTech Connect

    Park,S.; Borbat, P.; Gonzalez-Bonet, G.; Bhatnagar, J.; Pollard, A.; Freed, J.; Bilwes, A.; Crane, B.

    2006-01-01

    In bacterial chemotaxis, an assembly of transmembrane receptors, the CheA histidine kinase and the adaptor protein CheW processes environmental stimuli to regulate motility. The structure of a Thermotoga maritima receptor cytoplasmic domain defines CheA interaction regions and metal ion-coordinating charge centers that undergo chemical modification to tune receptor response. Dimeric CheA-CheW, defined by crystallography and pulsed ESR, positions two CheWs to form a cleft that is lined with residues important for receptor interactions and sized to clamp one receptor dimer. CheW residues involved in kinase activation map to interfaces that orient the CheW clamps. CheA regulatory domains associate in crystals through conserved hydrophobic surfaces. Such CheA self-contacts align the CheW receptor clamps for binding receptor tips. Linking layers of ternary complexes with close-packed receptors generates a lattice with reasonable component ratios, cooperative interactions among receptors and accessible sites for modification enzymes.

  11. The Structure of a Soluble Chemoreceptor Suggests a Mechanism for Propagating Conformational Signals

    SciTech Connect

    Pollard, Abiola M.; Bilwes, Alexandrine M.; Crane, Brian R.; Cornell

    2009-09-02

    Transmembrane chemoreceptors, also known as methyl-accepting chemotaxis proteins (MCPs), translate extracellular signals into intracellular responses in the bacterial chemotaxis system. MCP ligand binding domains control the activity of the CheA kinase, situated {approx}200 {angstrom} away, across the cytoplasmic membrane. The 2.17 {angstrom} resolution crystal structure of a Thermotoga maritima soluble receptor (Tm14) reveals distortions in its dimeric four-helix bundle that provide insight into the conformational states available to MCPs for propagating signals. A bulge in one helix generates asymmetry between subunits that displaces the kinase-interacting tip, which resides more than 100 {angstrom} away. The maximum bundle distortion maps to the adaptation region of transmembrane MCPs where reversible methylation of acidic residues tunes receptor activity. Minor alterations in coiled-coil packing geometry translate the bulge distortion to a >25 {angstrom} movement of the tip relative to the bundle stalks. The Tm14 structure discloses how alterations in local helical structure, which could be induced by changes in methylation state and/or by conformational signals from membrane proximal regions, can reposition a remote domain that interacts with the CheA kinase.

  12. New compatible solutes related to Di-myo-inositol-phosphate in members of the order Thermotogales.

    PubMed Central

    Martins, L O; Carreto, L S; Da Costa, M S; Santos, H

    1996-01-01

    The accumulation of intracellular organic solutes was examined in six species of the order Thermotogales by nuclear magnetic resonance spectroscopy. The newly discovered compounds di-2-O-beta-mannosyl-di-myo-inositol-1,1'(3,3')-phosphate and di-myo-inositol-1,3'-phosphate were identified in Thermotoga maritima and Thermotoga neapolitana. In the latter species, at the optimum temperature and salinity the organic solute pool was composed of di-myo-inositol-1,1'(3,3')-phosphate, beta-glutamate, and alpha-glutamate in addition to di-myo-inositol-1,3'-phosphate and di-2-O-beta-mannosyl-di-myo-inositol-1,1'(3,3')-phosphate. The concentrations of the last two solutes increased dramatically at supraoptimal growth temperatures, whereas beta-glutamate increased mainly in response to a salinity stress. Nevertheless, di-myo-inositol-1,1'(3,3')-phosphate was the major compatible solute at salinities above the optimum for growth. The amino acids alpha-glutamate and proline were identified under optimum growth conditions in Thermosipho africanus, and beta-mannosylglycerate, trehalose, and glycine betaine were detected in Petrotoga miotherma. Organic solutes were not detected, under optimum growth conditions, in Thermotoga thermarum and Fervidobacterium islandicum, which have a low salt requirement or none. PMID:8824608

  13. Laūq: A Sustained-Release Dosage Form for Respiratory Disorders in Traditional Persian Medicine.

    PubMed

    Karegar-Borzi, Hossein; Salehi, Mehdi; Rahimi, Roja

    2016-01-01

    Laūq is a pharmaceutical dosage form that had been mainly used for the treatment of various respiratory disorders in traditional Persian medicine. It is important from 2 aspects: a dosage form with efficient and optimum delivery of drugs to the respiratory tract and biological effects of its ingredients. Natural medicine in laūq has been demonstrated to act in respiratory disorders by their antitussive, antiallergic, anti-inflammatory, antioxidant, spasmolytic, and antibacterial activities. Some of these natural remedies act by most of the mentioned mechanisms such as Cydonia oblonga, Glycyrrhiza glabra, Crocus sativus, Hyssopus officinalis, Foeniculum vulgare, and honey. However, the evidence is limited including Cassia fistula, Papaver somniferum, and Drimia maritima. According to positive pharmacokinetic and pharmacodynamic aspects of laūqs, they may be considered as efficient dosage forms for delivery of drugs to the respiratory tract. For better compatibility of patients, it could be substituted laūqs with newer drug delivery systems like lozenges.

  14. Structure of the entire cytoplasmic portion of a sensor histidine-kinase protein

    PubMed Central

    Marina, Alberto; Waldburger, Carey D; Hendrickson, Wayne A

    2005-01-01

    The large majority of histidine kinases (HKs) are multifunctional enzymes having autokinase, phosphotransfer and phosphatase activities, and most of these are transmembrane sensor proteins. Sensor HKs possess conserved cytoplasmic phosphorylation and ATP-binding kinase domains. The different enzymatic activities require participation by one or both of these domains, implying the need for different conformational states. The catalytic domains are linked to the membrane through a coiled-coil segment that sometimes includes other domains. We describe here the first crystal structure of the complete cytoplasmic region of a sensor HK, one from the thermophile Thermotoga maritima in complex with ADPβN at 1.9 Å resolution. The structure reveals previously unidentified functions for several conserved residues and reveals the relative disposition of domains in a state seemingly poised for phosphotransfer. The structure thereby inspires hypotheses for the mechanisms of autophosphorylation, phosphotransfer and response-regulator dephosphorylation, and for signal transduction through the coiled-coil segment. Mutational tests support the functional relevance of interdomain contacts. PMID:16319927

  15. 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

  16. Paleobiology of the Sand Beneath the Valders Diamicton at Valders, Wisconsin

    USGS Publications Warehouse

    Maher, L.J.; Miller, N.G.; Baker, R.G.; Curry, B. Brandon; Mickelson, D.M.

    1998-01-01

    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 Picea and Artemisia, but the low percentages of many other types of longdistance 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 alpinum type, Silene acaulis, Sibbaldia procumbens, Dryas integrifolia, Vaccinium uliginosum var. 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. ?? 1998 University of Washington.

  17. Tidal saline wetland regeneration of sentinel vegetation types in the Northern Gulf of Mexico: An overview

    USGS Publications Warehouse

    Jones, Scott F; Stagg, Camille L.; Krauss, Ken W.; Hester, Mark W.

    2016-01-01

    Tidal saline wetlands in the Northern Gulf of Mexico (NGoM) are dynamic and frequently disturbed systems that provide myriad ecosystem services. For these services to be sustained, dominant macrophytes must continuously recolonize and establish after disturbance. Macrophytes accomplish this regeneration through combinations of vegetative propagation and sexual reproduction, the relative importance of which varies by species. Concurrently, tidal saline wetland systems experience both anthropogenic and natural hydrologic alterations, such as levee construction, sea-level rise, storm impacts, and restoration activities. These hydrologic alterations can affect the success of plant regeneration, leading to large-scale, variable changes in ecosystem structure and function. This review describes the specific regeneration requirements of four dominant coastal wetland macrophytes along the NGoM (Spartina alterniflora, Avicennia germinans, Juncus roemerianus, and Batis maritima) and compares them with current hydrologic alterations to provide insights into potential future changes in dominant ecosystem structure and function and to highlight knowledge gaps in the current literature that need to be addressed.

  18. Ecological correlates of variable organ sizes and fat loads in the most northerly-wintering shorebirds

    USGS Publications Warehouse

    Ruthrauff, Daniel R.; Dekinga, Anne; Gill, R.E.; Summers, R.W.; Piersma, Theunis

    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.

  19. Crystal structure of a two-subunit TrkA octameric gating ring assembly

    DOE PAGES

    Deller, Marc C.; Johnson, Hope A.; Miller, Mitchell D.; Spraggon, Glen; Elsliger, Marc -André; Wilson, Ian A.; Lesley, Scott A.; Ye, Sheng

    2015-03-31

    The TM1088 locus of T. maritima codes for two proteins designated TM1088A and TM1088B, which combine to form the cytosolic portion of a putative Trk K⁺ transporter. We report the crystal structure of this assembly to a resolution of 3.45 Å. The high resolution crystal structures of the components of the assembly, TM1088A and TM1088B, were also determined independently to 1.50 Å and 1.55 Å, respectively. The TM1088 proteins are structurally homologous to each other and to other K⁺ transporter proteins, such as TrkA. These proteins form a cytosolic gating ring assembly that controls the flow of K⁺ ions acrossmore » the membrane. TM1088 represents the first structure of a two-subunit Trk assembly. Despite the atypical genetics and chain organization of the TM1088 assembly, it shares significant structural homology and an overall quaternary organization with other single-subunit K⁺ gating ring assemblies. This structure provides the first structural insights into what may be an evolutionary ancestor of more modern single-subunit K⁺ gating ring assemblies.« less

  20. Crystal structure of a two-subunit TrkA octameric gating ring assembly

    SciTech Connect

    Deller, Marc C.; Johnson, Hope A.; Miller, Mitchell D.; Spraggon, Glen; Elsliger, Marc -André; Wilson, Ian A.; Lesley, Scott A.; Ye, Sheng

    2015-03-31

    The TM1088 locus of T. maritima codes for two proteins designated TM1088A and TM1088B, which combine to form the cytosolic portion of a putative Trk K⁺ transporter. We report the crystal structure of this assembly to a resolution of 3.45 Å. The high resolution crystal structures of the components of the assembly, TM1088A and TM1088B, were also determined independently to 1.50 Å and 1.55 Å, respectively. The TM1088 proteins are structurally homologous to each other and to other K⁺ transporter proteins, such as TrkA. These proteins form a cytosolic gating ring assembly that controls the flow of K⁺ ions across the membrane. TM1088 represents the first structure of a two-subunit Trk assembly. Despite the atypical genetics and chain organization of the TM1088 assembly, it shares significant structural homology and an overall quaternary organization with other single-subunit K⁺ gating ring assemblies. This structure provides the first structural insights into what may be an evolutionary ancestor of more modern single-subunit K⁺ gating ring assemblies.

  1. Tidal saline wetland regeneration of sentinel vegetation types in the Northern Gulf of Mexico: An overview

    NASA Astrophysics Data System (ADS)

    Jones, Scott F.; Stagg, Camille L.; Krauss, Ken W.; Hester, Mark W.

    2016-06-01

    Tidal saline wetlands in the Northern Gulf of Mexico (NGoM) are dynamic and frequently disturbed systems that provide myriad ecosystem services. For these services to be sustained, dominant macrophytes must continuously recolonize and establish after disturbance. Macrophytes accomplish this regeneration through combinations of vegetative propagation and sexual reproduction, the relative importance of which varies by species. Concurrently, tidal saline wetland systems experience both anthropogenic and natural hydrologic alterations, such as levee construction, sea-level rise, storm impacts, and restoration activities. These hydrologic alterations can affect the success of plant regeneration, leading to large-scale, variable changes in ecosystem structure and function. This review describes the specific regeneration requirements of four dominant coastal wetland macrophytes along the NGoM (Spartina alterniflora, Avicennia germinans, Juncus roemerianus, and Batis maritima) and compares them with current hydrologic alterations to provide insights into potential future changes in dominant ecosystem structure and function and to highlight knowledge gaps in the current literature that need to be addressed.

  2. A peroxiredoxin Q homolog from gentians is involved in both resistance against fungal disease and oxidative stress.

    PubMed

    Kiba, Akinori; Nishihara, Masahiro; Tsukatani, Nobue; Nakatsuka, Takashi; Kato, Yoshiaki; Yamamura, Saburo

    2005-06-01

    An antifungal protein (GtAFP1) showing antimicrobial activity against phytopathogenic fungi was purified from leaves of Gentiana triflora. The deduced amino acid sequence of the cDNA of the corresponding gene, GtAFP1, showed 94, 75, 72 and 63% amino acid identities with peroxiredoxin Q from Populus balsamifera x P. deltoides subsp. trichocarpa, Sedum lineare, Suaeda maritima and Arabidopsis thaliana, respectively. The GtAFP1 gene is suggested to be present in the genome in one to two copies and was expressed in the leaves, roots and stems. Expression of GtAFP1 was induced by treatment with salicylic acid, but not methyl jasmonate. Recombinant GtAFP1 protein showed not only antifungal activity but also thioredoxin-dependent peroxidase activity. Overexpression of GtAFP1 in tobacco plants improved tolerance not only against fungal diseases but also against oxidative stress. These results indicate that GtAFP1 might act as a disease and oxidative stress defensive gene in plants and could be useful for engineering stress-resistant plants.

  3. 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.

  4. Allosteric Inhibitors at the Heterodimer Interface of Imidazole Glycerol Phosphate Synthase

    NASA Astrophysics Data System (ADS)

    Snoeberger, Ning-Shiuan Nicole

    Imidazole glycerol phosphate synthase (IGPS) from Thermotoga maritima is a heterodimeric enzyme composed of the HisH and HisF proteins. It is attractive as a pathological target since it is absent in mammals but found in plant and opportunistic human pathogens. IGPS was experimentally determined to be a V-type allosteric enzyme that is involved in an essential biosynthetic pathway of microorganisms. The enzyme catalyzes the hydrolysis of glutamine to form NH3 in the HisH protein, followed by cyclization of NH3 with N'-[(5'-phosphoribulosyl)imino]-5-aminoimidazole-4-carboxamide-ribonucleotide (PRFAR) in the HisF subunit, forming imidazole glycerol phosphate (IGP) and 5-aminoimidazole-4-carboxamide ribotide (AICAR) that enter the histidine and purine biosynthetic pathways. Allosteric motions induced upon the binding of the effector PRFAR to HisF propagate through the non-covalent HisH/HisF interface and synchronize catalytic activity at the two distant active sites. However, the nature of the allosteric pathway and the feasibility of manipulating signal transduction by using allosteric drug-like molecules remain to be established. Molecular docking studies of commercial drugs at the HisH/HisF interface were used to identify stable candidates with a potential allosteric effect on the reaction mechanism. Molecular dynamic simulations and calculations of NMR chemical shifts were combined to elucidate the allosteric pathway of IGPS.

  5. Retention of tannic acid and condensed tannin by Fe-oxide-coated quartz sand.

    PubMed

    Kaal, J; Nierop, K G J; Verstraten, J M

    2005-07-01

    This paper intends to shed light on the interactions between tannin and mineral soil particles. For that purpose, aqueous solution of condensed tannin (CT) (derived from Black pine (Pinus nigra var. maritima)) and commercially available tannic acid (TA) were added to purified quartz (Qtz) sand and quartz sand coated with either goethite (Gt) or ferrihydrite (Fh). After solvent removal by evaporation the samples were extracted by water. The extracts were analysed for organic carbon, total phenolics and CT. The extractability of the two tannins was small and increased in the order Qtz-Fh < Qtz-Gt < Qtz. For all mineral samples, TA was more extractable than CT. Bonding of tannins to the mineral samples and the partial peptisation of the Fe oxide coatings upon the binding resulted in complex tannin release curves. Our results suggest that the inextractability of tannins from natural soils and the absence of tannins in soil leachates might be caused by strong adsorption on soil minerals such as Qtz and Fe (oxy)(hydr)oxides. The results of competition experiments with mixtures of both tannins demonstrate that the CTs, and TA in particular, can release large amounts of Fe (oxides), suggesting that the tannins are excellent metal-mobilising agents. We therefore suggest that the fate of tannins in the mineral soil environment is highly dependent on the abundance of weakly bonded secondary oxides.

  6. A Rapid and Efficient Luminescence-based Method for Assaying Phosphoglycosyltransferase Enzymes

    PubMed Central

    Das, Debasis; Walvoort, Marthe. T. C.; Lukose, Vinita; Imperiali, Barbara

    2016-01-01

    Phosphoglycosyltransferases (PGTs) are families of integral membrane proteins with intriguingly diverse architectures. These enzymes function to initiate many important biosynthetic pathways including those leading to peptidoglycan, N-linked glycoproteins and lipopolysaccharide O-antigen. In spite of tremendous efforts, characterization of these enzymes remains a challenge not only due to the inherent difficulties associated with the purification of integral membrane proteins but also due to the limited availability of convenient assays. Current PGT assays include radioactivity-based methods, which rely on liquid-liquid or solid-liquid extractions, multienzyme systems linked to lactate dehydrogenase and NAD+ generation, and HPLC-based approaches, all of which may suffer from low sensitivity and low throughput. Herein, we present the validation of a new luminescence-based assay (UMP-Glo) for measuring activities of PGT enzymes. This assay measures UMP, the by-product of PGT reactions, in a sensitive and quantitative manner by measuring the luminescence output in a discontinuous coupled assay system. The assay is rapid and robust in nature, and also compatible with microtiter plate formats. Activity and kinetic parameters of PglC, a PGT from Campylobacter jejuni, were quickly established using this assay. The efficacy of the assay was further corroborated using two different PGTs; PglC from Helicobacter pullorum and WecA from Thermatoga maritima. PMID:27624811

  7. Structural and functional studies of a metallo-β-lactamase unveil a new type of structurally encoded nickel-containing heterodinuclear site.

    PubMed

    Choi, Hwajung; Kim, Hee Jung; Matsuura, Atsushi; Mikami, Bunzo; Yoon, Hye Jin; Lee, Hyung Ho

    2015-10-01

    The selection of correct metal ions with high fidelity against competing cellular cations is crucial for the function of many metalloenzymes; however, the understanding of the principles that govern metal selectivity is still incomplete. In this study, the crystal structure of the Tm1162 protein from Thermotoga maritima, a metallo-β-lactamase, is reported. Several crystal structures of wild-type Tm1162 and its mutants were solved. Homologues of Tm1162 are widely distributed in bacteria and archaea, including several human pathogens. The monomer possesses an αβ/βα fold, with the core β-strands having the β-sheet sandwich structure common to the metallo-β-lactamase superfamily. Tm1162 exists as a trimer in the crystal and this trimeric unit is likely to be present in solution. In the trimer, three active sites reside at the interface between subunits, suggesting that the oligomeric assembly is crucial for catalysis. A new type of structurally encoded heterodinuclear site has been identified by confirming the identity of nickel-containing heteronuclear sites in Tm1162 via X-ray absorption spectroscopy and anomalous difference Fourier maps. The second coordination sphere, including His8 and Glu73, maintains the side-chain orientations of histidines and stabilizes the metal-binding site. Nickel coordination was crucial for the oligomerization of Tm1162. The nickel-dependent and manganese-dependent β-lactamase and phosphodiesterase activities of Tm1162 have also been characterized.

  8. One-Pot Biosynthesis of High-Concentration α-Glucose 1-Phosphate from Starch by Sequential Addition of Three Hyperthermophilic Enzymes.

    PubMed

    Zhou, Wei; You, Chun; Ma, Hongwu; Ma, Yanhe; Zhang, Y-H Percival

    2016-03-01

    α-Glucose 1-phosphate (G1P) is synthesized from 5% (w/v) corn starch and 1 M phosphate mediated by α-glucan phosphorylase (αGP) from the thermophilic bacterium Thermotoga maritima at pH 7.2 and 70 °C. To increase G1P yield from corn starch containing branched amylopectin, a hyper-thermostable isoamylase from Sulfolobus tokodaii was added for simultaneous starch gelatinization and starch-debranching hydrolysis at 85 °C and pH 5.5 before αGP use. The pretreatment of isoamylase increased G1P titer from 120 mM to 170 mM. To increase maltose and maltotriose utilization, the third thermostable enzyme, 4-glucanotransferase (4GT) from Thermococcus litoralis, was added during the late stage of G1P biotransformation, further increasing G1P titer to 200 mM. This titer is the highest G1P level obtained on starch or its derived products (maltodextrin and soluble starch). This study suggests that in vitro multienzyme biotransformation has an advantage of great engineering flexibility in terms of space and time compared with microbial fermentation.

  9. Biosynthesis of D-xylulose 5-phosphate from D-xylose and polyphosphate through a minimized two-enzyme cascade.

    PubMed

    Kim, Jae-Eung; Zhang, Y-H Percival

    2016-02-01

    Sugar phosphates cannot be produced easily by microbial fermentation because negatively-charged compounds cannot be secreted across intact cell membrane. D-xylulose 5-phosphate (Xu5P), a very expensive sugar phosphate, was synthesized from D-xylose and polyphosphate catalyzed by enzyme cascades in one pot. The synthetic enzymatic pathway comprised of xylose isomerase and xylulokinase was designed to produce Xu5P, along with a third enzyme, polyphosphate kinase, responsible for in site ATP regeneration. Due to the promiscuous activity of the ATP-based xylulokinase from a hyperthermophilic bacterium Thermotoga maritima on polyphosphate, the number of enzymes in the pathway was minimized to two without polyphosphate kinase. The reactions catalyzed by the two-enzyme and three-enzyme pathways were compared for Xu5P production, and the reaction conditions were optimized by examining effects of reaction temperature, enzyme ratio and substrate concentration. The optimized two-enzyme system produced 32 mM Xu5P from 50 mM xylose and polyphosphate after 36 h at 45°C. Biosynthesis of less costly Xu5P from D-xylose and polyphosphate could be highly feasible via this minimized two-enzyme pathway.

  10. Structural Characterization and Comparative Phylogenetic Analysis of Escherichia coli HemK, a Protein (N5)-glutamine Methyltransferase

    PubMed Central

    Yang, Zhe; Shipman, Lance; Zhang, Meng; Anton, Brian P.; Roberts, Richard J.; Cheng, Xiaodong

    2009-01-01

    Protein glutamine methylation at GGQ sites of protein chain release factors plays a pivotal role in the termination of translation. We report here the crystal structure of the Escherichia coli HemK protein (N5)-glutamine methyltransferase (MTase) in a binary complex with the methyl-donor product S-adenosyl-l-homocysteine (AdoHcy). HemK contains two domains: a putative substrate binding domain at the N terminus consisting of a five helix bundle and a seven-stranded catalytic domain at the C terminus that harbors the binding site for AdoHcy. The two domains are linked by a β-hairpin. Structure-guided sequence analysis of the HemK family revealed 11 invariant residues functioning in methyl-donor binding and catalysis of methyl transfer. The putative substrate-binding domains of HemK from E. coli and Thermotoga maritima are structurally similar, despite the fact that they share very little sequence similarity. When the two proteins are aligned structurally, the helical N-terminal domain is subject to approximately 10° of hinge movement relative to the C-terminal domain. The apparent hinge mobility of the two domains may reflect functional importance during the reaction cycle. Comparative phylogenetic analysis of the hemK gene and its frequent neighbor gene, prfA, which encodes a major substrate, provides evidence for several examples of lateral gene transfer. PMID:15223314

  11. A Robust and Versatile Method of Combinatorial Chemical Synthesis of Gene Libraries via Hierarchical Assembly of Partially Randomized Modules

    PubMed Central

    Popova, Blagovesta; Schubert, Steffen; Bulla, Ingo; Buchwald, Daniela; Kramer, Wilfried

    2015-01-01

    A major challenge in gene library generation is to guarantee a large functional size and diversity that significantly increases the chances of selecting different functional protein variants. The use of trinucleotides mixtures for controlled randomization results in superior library diversity and offers the ability to specify the type and distribution of the amino acids at each position. Here we describe the generation of a high diversity gene library using tHisF of the hyperthermophile Thermotoga maritima as a scaffold. Combining various rational criteria with contingency, we targeted 26 selected codons of the thisF gene sequence for randomization at a controlled level. We have developed a novel method of creating full-length gene libraries by combinatorial assembly of smaller sub-libraries. Full-length libraries of high diversity can easily be assembled on demand from smaller and much less diverse sub-libraries, which circumvent the notoriously troublesome long-term archivation and repeated proliferation of high diversity ensembles of phages or plasmids. We developed a generally applicable software tool for sequence analysis of mutated gene sequences that provides efficient assistance for analysis of library diversity. Finally, practical utility of the library was demonstrated in principle by assessment of the conformational stability of library members and isolating protein variants with HisF activity from it. Our approach integrates a number of features of nucleic acids synthetic chemistry, biochemistry and molecular genetics to a coherent, flexible and robust method of combinatorial gene synthesis. PMID:26355961

  12. Postglacial vegetation history of Orcas Island, northwestern Washington

    NASA Astrophysics Data System (ADS)

    Leopold, Estella B.; Dunwiddie, Peter W.; Whitlock, Cathy; Nickmann, Rudy; Watts, William A.

    2016-05-01

    The revegetation of islands following retreat of Pleistocene glaciers is of great biogeographical interest. The San Juan Islands, Washington, feature regionally distinctive xerophytic plant communities, yet their vegetation history, as it relates to past climate and sea level, is poorly known. We describe a 13,700-year-old pollen record from Killebrew Lake Fen and compare the vegetation reconstruction with others from the region. The data suggest that the narrow channels surrounding Orcas Island were not a barrier to early postglacial immigration of plants. Between 13,700 and 12,000 cal yr BP, Pinus, Tsuga, Picea, Alnus viridis, and possibly Juniperus maritima were present in a mosaic that supported Bison antiquus and Megalonyx. The rise of Alnus rubra-type pollen and Pteridium spores at ca. 12,000 cal yr BP suggests a warming trend and probably more fires. Temperate conifer taxa, including Cupressaceae, Pseudotsuga, Tsuga heterophylla, and Abies, increased after 11,000 cal yr BP and especially in the last 7000 cal yr BP. After 6000 cal yr BP, Pseudotsuga and Cupressaceae dominated the vegetation. The last 1500 yr were the wettest period of the record. Due to its rain shadow location, Orcas Island experienced drier conditions than on the mainland during most of the postglacial period.

  13. Diversity and Plant Growth Promoting Capacity of Endophytic Fungi Associated with Halophytic Plants from the West Coast of Korea.

    PubMed

    Khalmuratova, Irina; Kim, Hyun; Nam, Yoon-Jong; Oh, Yoosun; Jeong, Min-Ji; Choi, Hye-Rim; You, Young-Hyun; Choo, Yeon-Sik; Lee, In-Jung; Shin, Jae-Ho; Yoon, Hyeokjun; Kim, Jong-Guk

    2015-12-01

    Five halophytic plant species, Suaeda maritima, Limonium tetragonum, Suaeda australis, Phragmites australis, and Suaeda glauca Bunge, which are native to the Muan salt marsh of South Korea, were examined for fungal endophytes by sequencing the internal transcribed spacer (ITS) region containing ITS1, 5.8S rRNA, and ITS2. In total, 160 endophytic fungal strains were isolated and identified from the roots of the 5 plant species. Taxonomically, all 160 strains belonged to the phyla Ascomycota, Basidiomycota, and Zygomycota. The most dominant genus was Fusarium, followed by the genera Penicillium and Alternaria. Subsequently, using 5 statistical methods, the diversity indices of the endophytes were determined at genus level. Among these halophytic plants, P. australis was found to host the greatest diversity of endophytic fungi. Culture filtrates of endophytic fungi were treated to Waito-C rice seedlings for plant growth-promoting effects. The fungal strain Su-3-4-3 isolated from S. glauca Bunge provide the maximum plant length (20.1 cm) in comparison with wild-type Gibberella fujikuroi (19.6 cm). Consequently, chromatographic analysis of the culture filtrate of Su-3-4-3 showed the presence of physiologically active gibberellins, GA1 (0.465 ng/mL), GA3 (1.808 ng/mL) along with other physiologically inactive GA9 (0.054 ng/mL) and GA24 (0.044 ng/mL). The fungal isolate Su-3-4-3 was identified as Talaromyces pinophilus.

  14. Temporal sampling helps unravel the genetic structure of naturally occurring populations of a phytoparasitic nematode. 2. Separating the relative effects of gene flow and genetic drift.

    PubMed

    Gracianne, Cécile; Jan, Pierre-Loup; Fournet, Sylvain; Olivier, Eric; Arnaud, Jean-François; Porte, Catherine; Bardou-Valette, Sylvie; Denis, Marie-Christine; Petit, Eric J

    2016-09-01

    Studying wild pathogen populations in natural ecosystems offers the opportunity to better understand the evolutionary dynamics of biotic diseases in crops and to enhance pest control strategies. We used simulations and genetic markers to investigate the spatial and temporal population genetic structure of wild populations of the beet cyst nematode Heterodera schachtii on a wild host plant species, the sea beet (Beta vulgaris spp. maritima), the wild ancestor of cultivated beets. Our analysis of the variation of eight microsatellite loci across four study sites showed that (i) wild H. schachtii populations displayed fine-scaled genetic structure with no evidence of substantial levels of gene flow beyond the scale of the host plant, and comparisons with simulations indicated that (ii) genetic drift substantially affected the residual signals of isolation-by-distance processes, leading to departures from migration-drift equilibrium. In contrast to what can be suspected for (crop) field populations, this showed that wild cyst nematodes have very low dispersal capabilities and are strongly disconnected from each other. Our results provide some key elements for designing pest control strategies, such as decreasing passive dispersal events to limit the spread of virulence among field nematode populations. PMID:27606008

  15. 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.

  16. Enzymatic Hydrolytic Resolution of Racemic Ibuprofen Ethyl Ester Using an Ionic Liquid as Cosolvent.

    PubMed

    Wei, Tao; Yang, Kunpeng; Bai, Bing; Zang, Jie; Yu, Xuan; Mao, Duobin

    2016-01-01

    The aim of this study was to develop an ionic liquid (IL) system for the enzymatic resolution of racemic ibuprofen ethyl ester to produce (S)-ibuprofen. Nineteen ILs were selected for use in buffer systems to investigate the effects of ILs as cosolvents for the production of (S)-ibuprofen using thermostable esterase (EST10) from Thermotoga maritima. Analysis of the catalytic efficiency and conformation of EST10 showed that [OmPy][BF₄] was the best medium for the EST10-catalyzed production of (S)-ibuprofen. The maximum degree of conversion degree (47.4%), enantiomeric excess of (S)-ibuprofen (96.6%) and enantiomeric ratio of EST10 (177.0) were achieved with an EST10 concentration of 15 mg/mL, racemic ibuprofen ethyl ester concentration of 150 mM, at 75 °C , with a reaction time of 10 h. The reaction time needed to achieve the highest yield of (S)-ibuprofen was decreased from 24 h to 10 h. These results are relevant to the proposed application of ILs as solvents for the EST10-catalyzed production of (S)-ibuprofen. PMID:27420042

  17. Marinomonas spartinae sp. nov., a novel species with plant-beneficial properties.

    PubMed

    Lucena, Teresa; Mesa, Jennifer; Rodriguez-Llorente, Ignacio D; Pajuelo, Eloisa; Caviedes, Miguel Ángel; Ruvira, María A; Pujalte, María J

    2016-04-01

    Two strains of Gram-stain-negative, chemo-organotrophic, aerobic and halophilic gammaproteobacteria, isolated from within the stem and roots of Spartina maritima in salt marshes from the south Atlantic Spanish coast, were found to represent a novel species in the genus Marinomonas through phylogenetic analysis of their 16S rRNA genes and phenotypic characterization. 16S rRNA gene sequences of the two strains shared < 96.2% similarity with other Marinomonas species, with Marimonas alcarazii being the most similar in sequence. They required sodium ions for growth, were able to thrive at low (4 °C) temperatures and at salinities of 12-15%, were unable to hydrolyse any tested macromolecule except casein, and grew with different monosaccharides, disaccharides, sugar alcohols, organic acids and amino acids. The novel species differed from other Marinomonas species in the use of several sole carbon sources, its temperature and salinity ranges for growth, ion requirements and cellular fatty acid composition, which included C16:0, C16:1 and C18:1 as major components and C10:0 3-OH, C12:0 and C12:0 3-OH as minor components. The name Marinomonas spartinae sp. nov. is proposed, with SMJ19T (=CECT 8886T=KCTC 42958T) as the type strain. PMID:26821806

  18. Metal speciation in salt marsh sediments: Influence of halophyte vegetation in salt marshes with different morphology

    NASA Astrophysics Data System (ADS)

    Pedro, Sílvia; Duarte, Bernardo; Raposo de Almeida, Pedro; Caçador, Isabel

    2015-12-01

    Salt marshes provide environmental conditions that are known to affect metal speciation in sediments. The elevational gradient along the marsh and consequent differential flooding are some of the major factors influencing halophytic species distribution and coverage due to their differential tolerance to salinity and submersion. Different species, in turn, also have distinct influences on the sediment's metal speciation, and its metal accumulation abilities. The present work aimed to evaluate how different halophyte species in two different salt marshes could influence metal partitioning in the sediment at root depth and how that could differ from bare sediments. Metal speciation in sediments around the roots (rhizosediments) of Halimione portulacoides, Sarcocornia fruticosa and Spartina maritima was determined by sequentially extracting operationally defined fractions with solutions of increasing strength and acidity. Rosário salt marsh generally showed higher concentrations of all metals in the rhizosediments. Metal partitioning was primarily related to the type of metal, with the elements' chemistry overriding the environment's influence on fractionation schemes. The most mobile elements were Cd and Zn, with greater availability being found in non-vegetated sediments. Immobilization in rhizosediments was predominantly influenced by the presence of Fe and Mn oxides, as well as organic complexes. In the more mature of both salt marshes, the differences between vegetated and non-vegetated sediments were more evident regarding S. fruticosa, while in the younger system all halophytes presented significantly different metal partitioning when compared to that of mudflats.

  19. Allatostatins C, double C and triple C, the result of a local gene triplication in an ancestral arthropod.

    PubMed

    Veenstra, Jan A

    2016-05-01

    Allatostatin C is the arthropod homolog of vertebrate somatostatin. The gene went through a local gene triplification leading to the existence of three genes coding such peptides, allatostatins C, CC and CCC. All three genes are still present in several chelicerates, such as the horseshoe crab Limulus polyphemus, several spiders and the scorpion Mesobuthus martensii, the myriapod Strigamia maritima, as well as at least two insect species, Locusta migratoria and Athalia rosae, a sawfly. All three peptides have well conserved primary structures and peptides can easily be classified as either allatostatin C, CC or CCC. In most insect species only two of the genes have been preserved. In many species, these are CC and CCC, but in Diptera, Lepidoptera and Coleoptera it are allatostatins C and CC that are still present. In some arthropod species two or even all three genes can still be found closely associated in the genome and are present on the same scaffold showing that a local amplification was at the origin of these genes. PMID:27102937

  20. Identification of amino acids of the beet necrotic yellow vein virus p25 protein required for induction of the resistance response in leaves of Beta vulgaris plants.

    PubMed

    Chiba, Soutaro; Miyanishi, Masaki; Andika, Ida Bagus; Kondo, Hideki; Tamada, Tetsuo

    2008-05-01

    The RNA3-encoded p25 protein of beet necrotic yellow vein virus (BNYVV) is responsible for the production of rhizomania symptoms of sugar beet roots (Beta vulgaris subsp. vulgaris). Here, it was found that the presence of the p25 protein is also associated with the resistance response in rub-inoculated leaves of sugar beet and wild beet (Beta vulgaris subsp. maritima) plants. The resistance phenotype displayed a range of symptoms from no visible lesions to necrotic or greyish lesions at the inoculation site, and only very low levels of virus and viral RNA accumulated. The susceptible phenotype showed large, bright yellow lesions and developed high levels of virus accumulation. In roots after Polymyxa betae vector inoculation, however, no drastic differences in virus and viral RNA accumulation levels were found between plants with susceptible and resistant phenotypes, except at an early stage of infection. There was a genotype-specific interaction between BNYVV strains and two selected wild beet lines (MR1 and MR2) and sugar beet cultivars. Sequence analysis of natural BNYVV isolates and site-directed mutagenesis of the p25 protein revealed that 3 aa residues at positions 68, 70 and 179 are important in determining the resistance phenotype, and that host-genotype specificity is controlled by single amino acid changes at position 68. The mechanism of the occurrence of resistance-breaking BNYVV strains is discussed.

  1. Retention of tannic acid and condensed tannin by Fe-oxide-coated quartz sand.

    PubMed

    Kaal, J; Nierop, K G J; Verstraten, J M

    2005-07-01

    This paper intends to shed light on the interactions between tannin and mineral soil particles. For that purpose, aqueous solution of condensed tannin (CT) (derived from Black pine (Pinus nigra var. maritima)) and commercially available tannic acid (TA) were added to purified quartz (Qtz) sand and quartz sand coated with either goethite (Gt) or ferrihydrite (Fh). After solvent removal by evaporation the samples were extracted by water. The extracts were analysed for organic carbon, total phenolics and CT. The extractability of the two tannins was small and increased in the order Qtz-Fh < Qtz-Gt < Qtz. For all mineral samples, TA was more extractable than CT. Bonding of tannins to the mineral samples and the partial peptisation of the Fe oxide coatings upon the binding resulted in complex tannin release curves. Our results suggest that the inextractability of tannins from natural soils and the absence of tannins in soil leachates might be caused by strong adsorption on soil minerals such as Qtz and Fe (oxy)(hydr)oxides. The results of competition experiments with mixtures of both tannins demonstrate that the CTs, and TA in particular, can release large amounts of Fe (oxides), suggesting that the tannins are excellent metal-mobilising agents. We therefore suggest that the fate of tannins in the mineral soil environment is highly dependent on the abundance of weakly bonded secondary oxides. PMID:15914150

  2. Crystal Structure of a Two-Subunit TrkA Octameric Gating Ring Assembly

    PubMed Central

    Deller, Marc C.; Johnson, Hope A.; Miller, Mitchell D.; Spraggon, Glen; Elsliger, Marc-André; Wilson, Ian A.; Lesley, Scott A.

    2015-01-01

    The TM1088 locus of T. maritima codes for two proteins designated TM1088A and TM1088B, which combine to form the cytosolic portion of a putative Trk K+ transporter. We report the crystal structure of this assembly to a resolution of 3.45 Å. The high resolution crystal structures of the components of the assembly, TM1088A and TM1088B, were also determined independently to 1.50 Å and 1.55 Å, respectively. The TM1088 proteins are structurally homologous to each other and to other K+ transporter proteins, such as TrkA. These proteins form a cytosolic gating ring assembly that controls the flow of K+ ions across the membrane. TM1088 represents the first structure of a two-subunit Trk assembly. Despite the atypical genetics and chain organization of the TM1088 assembly, it shares significant structural homology and an overall quaternary organization with other single-subunit K+ gating ring assemblies. This structure provides the first structural insights into what may be an evolutionary ancestor of more modern single-subunit K+ gating ring assemblies. PMID:25826626

  3. Structure of N-formylglycinamide ribonucleotide amidotransferase II (PurL) from Thermus thermophilus HB8

    PubMed Central

    Suzuki, Sakiko; Yanai, Hisaaki; Kanagawa, Mayumi; Tamura, Satoko; Watanabe, Yuzo; Fuse, Kyotaro; Baba, Seiki; Sampei, Gen-ichi; Kawai, Gota

    2012-01-01

    The crystal structure of PurL from Thermus thermophilus HB8 (TtPurL; TTHA1519) was determined in complex with an adenine nucleotide, PO4 3− and Mg2+ at 2.35 Å resolution. TtPurL consists of 29 α-helices and 28 β-strands, and one loop is disordered. TtPurL consists of four domains, A1, A2, B1 and B2, and the structures of the A1–B1 and A2–B2 domains were almost identical to each other. Although the sequence identity between TtPurL and PurL from Thermotoga maritima (TmPurL) is higher than that between TtPurL and the PurL domain of the large PurL from Salmonella typhimurium (StPurL), the secondary structure of TtPurL is much more similar to that of StPurL than to that of TmPurL. PMID:22232163

  4. The biological soil crusts of the San Nicolas Island: Enigmatic algae from a geographically isolated ecosystem

    USGS Publications Warehouse

    Flechtner, V.R.; Johansen, J.R.; Belnap, J.

    2008-01-01

    Composite soil samples from 7 sites on San Nicolas Island were evaluated quantitatively and qualitatively for the presence of cyanobacteria and eukaryotic microalgae. Combined data demonstrated a rich algal flora with 19 cyanobacterial and 19 eukaryotic microalgal genera being identified, for a total of 56 species. Nine new species were identified and described among the cyanobacteria and the eukaryotic microalgae that were isolated: Leibleinia edaphica, Aphanothece maritima, Chroococcidiopsis edaphica, Cyanosarcina atroveneta, Hassallia californica, Hassallia pseudoramosissima, Microchaete terrestre, Palmellopsis californiens, and Pseudotetracystis compactis. Distinct distributional patterns of algal taxa existed among sites on the island and among soil algal floras of western North America. Some algal taxa appeared to be widely distributed across many desert regions, including Microcoleus vaginatus, Nostoc punctiforme, Nostoc paludosum, and Tolypothrix distorta, Chlorella vulgaris, Diplosphaera cf. chodatii, Myrmecia astigmatica, Myrmecia biatorellae, Hantzschia amphioxys, and Luticola mutica. Some taxa share a distinctly southern distribution with soil algae from southern Arizona, southern California, and Baja California (e.g., Scenedesmus deserticola and Eustigmatos magnus). The data presented herein support the view that the cyanobacterial and microalgal floras of soil crusts possess significant biodiversity, much of it previously undescribed.

  5. A role for [Fe4S4] clusters in tRNA recognition—a theoretical study

    PubMed Central

    Stiebritz, Martin T.

    2014-01-01

    Over the past several years, structural studies have led to the unexpected discovery of iron–sulfur clusters in enzymes that are involved in DNA replication/repair and protein biosynthesis. Although these clusters are generally well-studied cofactors, their significance in the new contexts often remains elusive. One fascinating example is a tryptophanyl-tRNA synthetase from the thermophilic bacterium Thermotoga maritima, TmTrpRS, that has recently been structurally characterized. It represents an unprecedented connection among a primordial iron–sulfur cofactor, RNA and protein biosynthesis. Here, a possible role of the [Fe4S4] cluster in tRNA anticodon-loop recognition is investigated by means of density functional theory and comparison with the structure of a human tryptophanyl-tRNA synthetase/tRNA complex. It turns out that a cluster-coordinating cysteine residue, R224, and polar main chain atoms form a characteristic structural motif for recognizing a putative 5′ cytosine or 5′ 2-thiocytosine moiety in the anticodon loop of the tRNA molecule. This motif provides not only affinity but also specificity by creating a structural and energetical penalty for the binding of other bases, such as uracil. PMID:24753428

  6. X-ray crystallography and isothermal titration calorimetry studies of the Salmonella zinc transporter ZntB.

    PubMed

    Wan, Qun; Ahmad, Md Faiz; Fairman, James; Gorzelle, Bonnie; de la Fuente, María; Dealwis, Chris; Maguire, Michael E

    2011-05-11

    The ZntB Zn(2+) efflux system is important for maintenance of Zn(2+) homeostasis in Enterobacteria. We report crystal structures of ZntB cytoplasmic domains from Salmonella enterica serovar Typhimurium (StZntB) in dimeric and physiologically relevant homopentameric forms at 2.3 Å and 3.1 Å resolutions, respectively. The funnel-like structure is similar to that of the homologous Thermotoga maritima CorA Mg(2+) channel and a Vibrio parahaemolyticus ZntB (VpZntB) soluble domain structure. However, the central α7 helix forming the inner wall of the StZntB funnel is oriented perpendicular to the membrane instead of the marked angle seen in CorA or VpZntB. Consequently, the StZntB funnel pore is cylindrical, not tapered, which may represent an "open" form of the ZntB soluble domain. Our crystal structures and isothermal titration calorimetry data indicate that there are three Zn(2+) binding sites in the full-length ZntB, two of which could be involved in Zn(2+) transport.

  7. Integration of an [FeFe]-hydrogenase into the anaerobic metabolism of Escherichia coli

    PubMed Central

    Kelly, Ciarán L.; Pinske, Constanze; Murphy, Bonnie J.; Parkin, Alison; Armstrong, Fraser; Palmer, Tracy; Sargent, Frank

    2015-01-01

    Biohydrogen is a potentially useful product of microbial energy metabolism. One approach to engineering biohydrogen production in bacteria is the production of non-native hydrogenase activity in a host cell, for example Escherichia coli. In some microbes, hydrogenase enzymes are linked directly to central metabolism via diaphorase enzymes that utilise NAD+/NADH cofactors. In this work, it was hypothesised that heterologous production of an NAD+/NADH-linked hydrogenase could connect hydrogen production in an E. coli host directly to its central metabolism. To test this, a synthetic operon was designed and characterised encoding an apparently NADH-dependent, hydrogen-evolving [FeFe]-hydrogenase from Caldanaerobacter subterranus. The synthetic operon was stably integrated into the E. coli chromosome and shown to produce an active hydrogenase, however no H2 production was observed. Subsequently, it was found that heterologous co-production of a pyruvate::ferredoxin oxidoreductase and ferredoxin from Thermotoga maritima was found to be essential to drive H2 production by this system. This work provides genetic evidence that the Ca.subterranus [FeFe]-hydrogenase could be operating in vivo as an electron-confurcating enzyme. PMID:26839796

  8. 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.

  9. Crystal structure of a putative oligopeptide-binding periplasmic protein from a hyperthermophile.

    PubMed

    Yoon, Hye-Jin; Kim, Hee Jung; Mikami, Bunzo; Yu, Yeon Gyu; Lee, Hyung Ho

    2016-09-01

    Oligopeptide-binding proteins (Opps) are part of the ATP-binding cassette system, playing a crucial role in nutrient uptake and sensing the external environment in bacteria, including hyperthermophiles. Opps serve as a binding platform for diverse peptides; however, how these peptides are recognized by Opps is still largely unknown and few crystal structures of Opps from hyperthermophiles have been determined. To facilitate such an understanding, the crystal structure of a putative Opp, OppA from Thermotoga maritima (TmOppA), was solved at 2.6-Å resolution in the open conformation. TmOppA is composed of three domains. The N-terminal domain consists of twelve strands, nine helices, and four 310 helices, and the C-terminal domain consists of five strands, ten helices, and one 310 helix. These two domains are connected by the linker domain, which consists of two strands, three helices, and three 310 helices. Based on structural comparisons of TmOppA with other OppAs and binding studies, we suggest that TmOppA might be a periplasmic Opp. The most distinct feature of TmOppA is the insertion of two helices, which are lacking in other OppAs. A cavity volume between the N-terminal and C-terminal domains is suggested to be responsible for binding peptides of various lengths. PMID:27377296

  10. 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 β-stranded domain. The tetramer is assembled using a novel barrel-type oligomerization motif. PMID:11731804

  11. Cultivation of an immobilized (hyper)thermophilic marine microbial community in a bioreactor.

    PubMed

    Landreau, M; Duthoit, F; Roussel, E; Schönherr, S; Georges, Myriam; Godfroy, A; Le Blay, G

    2016-09-01

    Cultivation in a bioreactor of immobilized deep-sea hydrothermal microbial community was tested in order to assess the stability and reactivity of this new system. A community composed of eight hydrothermal strains was entrapped in a polymer matrix that was used to inoculate a continuous culture in a gas-lift bioreactor. The continuous culture was performed for 41 days at successively 60°C, 55°C, 60°C, 85°C and 60°C, at pH 6.5, in anaerobic condition and constant dilution rate. Oxic stress and pH variations were tested at the beginning of the incubation. Despite these detrimental conditions, three strains including two strict anaerobes were maintained in the bioreactor. High cell concentrations (3 × 10(8) cells mL(-1)) and high ATP contents were measured in both liquid fractions and beads. Cloning-sequencing and qPCR revealed that Bacillus sp. dominated at the early stage, and was later replaced by Thermotoga maritima and Thermococcus sp. Acetate, formate and propionate concentrations varied simultaneously in the liquid fractions. These results demonstrate that these immobilized cells were reactive to culture conditions. They were protected inside the beads during the stress period and released in the liquid fraction when conditions were more favorable. This confirms the advantage of immobilization that highlights the resilience capacity of certain hydrothermal microorganisms after a stress period. PMID:27528693

  12. Comparison of Three Ionic Liquid-Tolerant Cellulases by Molecular Dynamics

    PubMed Central

    Jaeger, Vance; Burney, Patrick; Pfaendtner, Jim

    2015-01-01

    We have employed molecular dynamics to investigate the differences in ionic liquid tolerance among three distinct family 5 cellulases from Trichoderma viride, Thermogata maritima, and Pyrococcus horikoshii. Simulations of the three cellulases were conducted at a range of temperatures in various binary mixtures of the ionic liquid 1-ethyl-3-methyl-imidazolium acetate with water. Our analysis demonstrates that the effects of ionic liquids on the enzymes vary in each individual case from local structural disturbances to loss of much of one of the enzyme’s secondary structure. Enzymes with more negatively charged surfaces tend to resist destabilization by ionic liquids. Specific and unique structural changes in the enzymes are induced by the presence of ionic liquids. Disruption of the secondary structure, changes in dynamical motion, and local changes in the binding pocket are observed in less tolerant enzymes. Ionic-liquid-induced denaturation of one of the enzymes is indicated over the 500 ns timescale. In contrast, the most tolerant cellulase behaves similarly in water and in ionic-liquid-containing mixtures. Unlike the heuristic approaches that attempt to predict enzyme stability using macroscopic properties, molecular dynamics allows us to predict specific atomic-level structural and dynamical changes in an enzyme’s behavior induced by ionic liquids and other mixed solvents. Using these insights, we propose specific experimentally testable hypotheses regarding the origin of activity loss for each of the systems investigated in this study. PMID:25692593

  13. Temporal sampling helps unravel the genetic structure of naturally occurring populations of a phytoparasitic nematode. 1. Insights from the estimation of effective population sizes.

    PubMed

    Jan, Pierre-Loup; Gracianne, Cécile; Fournet, Sylvain; Olivier, Eric; Arnaud, Jean-François; Porte, Catherine; Bardou-Valette, Sylvie; Denis, Marie-Christine; Petit, Eric J

    2016-03-01

    The sustainability of modern agriculture relies on strategies that can control the ability of pathogens to overcome chemicals or genetic resistances through natural selection. This evolutionary potential, which depends partly on effective population size (N e ), is greatly influenced by human activities. In this context, wild pathogen populations can provide valuable information for assessing the long-term risk associated with crop pests. In this study, we estimated the effective population size of the beet cyst nematode, Heterodera schachtii, by sampling 34 populations infecting the sea beet Beta vulgaris spp. maritima twice within a one-year period. Only 20 populations produced enough generations to analyze the variation in allele frequencies, with the remaining populations showing a high mortality rate of the host plant after only 1 year. The 20 analyzed populations showed surprisingly low effective population sizes, with most having N e close to 85 individuals. We attribute these low values to the variation in population size through time, systematic inbreeding, and unbalanced sex-ratios. Our results suggest that H. schachtii has low evolutionary potential in natural environments. Pest control strategies in which populations on crops mimic wild populations may help prevent parasite adaptation to host resistance.

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

    PubMed

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

    2004-06-01

    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 between a restored plant and a female (male-sterile) plant on G cytoplasm exhibited three sexual phenotypic classes: female, hermaphrodite and intermediate. The pattern of segregation suggests a genetic inheritance with two loci in epistatic interaction. Nevertheless, it was possible to apply a bulk segregant analysis approach to search for AFLP and microsatellite markers linked to the restorer locus ( RfG(1)) which controls the capacity to produce pollen [female versus non female (i.e. intermediates and hermaphrodites)] in the segregating population. A linkage group was constructed with four AFLP markers and nine microsatellites, and a total size of 40 cM (Kosambi). The closest marker, a microsatellite, was totally linked to RfG1, which was also flanked by two AFLP markers delimiting a 5 cM window. This linkage group was identified as being chromosome VIII where neither of the restorer loci of the Owen CMS are located.

  15. A new source of cytoplasmic male sterility found in wild beet and its relationship to other CMS types.

    PubMed

    Kawanishi, Yuki; Shinada, Hiroshi; Matsunaga, Muneyuki; Masaki, Yusuke; Mikami, Tetsuo; Kubo, Tomohiko

    2010-04-01

    We found a number of male-sterile plants in a wild beet (Beta vulgaris L. subsp. maritima) accession line, FR4-31. The inheritance study of the male sterility indicated the trait to be of the cytoplasmic type. The mitochondrial genome of FR4-31 proved to lack the male-sterility-associated genes preSatp6 and orf129, which are characteristic of the Owen CMS and I-12CMS(3) cytoplasms of beets, respectively. Instead, the truncated cox2 gene involved in G CMS originating from wild beets was present in the FR4-31 mitochondrial genome. In Southern hybridization using four mitochondrial gene probes, the FR4-31 cytoplasm showed patterns similar to those typical of the G cytoplasm. It is thus likely that the FR4-31 cytoplasm has a different CMS mechanism from both Owen CMS and I-12CMS(3), and that the FR4-31 and G cytoplasms resemble each other closely. A restriction map of the FR4-31 mitochondrial DNA was generated and aligned with those published for the Owen and normal fertile cytoplasms. The FR4-31 mitochondrial genome was revealed to differ extensively in arrangement from the Owen and normal genomes, and the male-sterile Owen and FR4-31 genomes seem to be derived independently from an ancestral genome.

  16. The effect of nitrogen loading on a brackish estuarine faunal community: A stable isotope approach

    USGS Publications Warehouse

    Keats, R.A.; Osher, L.J.; Neckles, H.A.

    2004-01-01

    Coastal ecosystems worldwide face increased nutrient enrichment from shoreline and watershed development and atmospheric pollution. We investigated the response of the faunal community of a small microtidal estuary dominated by Ruppia maritima (widgeon grass) in Maine, United States, to increased nitrogen loading using an in situ mesocosm enrichment experiment. Community response was characterized by assessing quantitative shifts in macroin-vertebrate community composition and identifying changes in food web structure using stable carbon and nitrogen isotope ratios of producers and consumers. The community was dominated by brackish water invertebrates including midge larvae, oligochaetes, damselfly larvae, amphipods, and ostracods. Experimental nutrient additions resulted in significantly lower densities of herbivorous chironomids and predatory damselflies and greater densities of deposit feeding oligochaetes. Grazing midge larvae (Chironomidae: Dicrotendipes, Cricotopus) consumed epiphytic algae under both natural and enriched conditions. Deposit feeding Chironomus was dependent on allochthonous sources of detritus under natural conditions and exhibited a shift to autochthonous sources of detritus under enriched conditions. Predatory Enallagma primarily consumed grazing chironomids under all but the highest loading conditions. Experimental nutrient loading resulted in an increase in generalist deposit feeders dependent on autochthonous sources of detritus.

  17. 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.

  18. Long day plants and the response to global warming: rapid evolutionary change in day length sensitivity is possible in wild beet.

    PubMed

    Van Dijk, H; Hautekèete, N

    2007-01-01

    Day length is a key factor in flowering induction in many plant species in a seasonal environment with flowering induction usually happening at shorter day lengths in lower latitudes. Now, the climate changes systematically at a considerable speed due to global warming. As a consequence, earlier flowering will be selected for in long day plants by favouring a lower threshold for day length sensitivity, on the condition of available genetic variability. Here, we show that there is considerable genetic variation for day length sensitivity in our study species, the seabeet Beta vulgaris subsp. maritima. In the northernmost natural populations without vernalization requirement, in southwest France, the necessary day length for flowering induction could be reduced by artificial selection in <10 generations from >13 h to <11 h, the latter value corresponding to populations in the Beta-species complex from Northern Africa and the eastern part of the Mediterranean tested under the same conditions. A quantitative genetic analysis provided evidence of a gradual change without detectable major genes. Additional experiments were carried out to separate the response to photoperiod from age and energy effects. A certain effect of energy availability has been found, whereas age effects could be excluded. These results indicate a considerable potential for evolutionary change in adjusting flowering time in a changing climate.

  19. Trophic plasticity of the gastropod Hydrobia ulvae within an intertidal bay (Roscoff, France): A stable isotope evidence

    NASA Astrophysics Data System (ADS)

    Riera, P.

    2010-01-01

    The study investigated the trophic ecology of the gastropod Hydrobia ulvae in different habitat types within an intertidal bay. The results point out two major trophic pathways involving H.ulvae in this bay. On the one hand, in sandy/muddy sediments Hydrobia derives most of its energy from allochtonous detritus derived from Enteromorpha sp and the total SOM pool. In addition, in these sediments, the phototrophic purple bacteria mats played a substantial trophic role in the diet of Hydrobia. On the other hand, in a Spartina maritima marsh, the gastropod appears firstly dependent of autochtonous detritus derived from this plant. The minor contribution of microphytobenthos to the diet of Hydrobia is consistent with a relatively low presence of epipelic diatoms at the sampling sites. These results provide evidence that the trophic ecology of H.ulvae inhabiting intertidal sediments is quite plastic and does not necessarily rely primarly on microphytobenthos. Consequently, in a single bay, the small spatial scale variability in the origin and availability of detritus have direct implications on the food incorporation by H.ulvae.

  20. A Rapid and Efficient Luminescence-based Method for Assaying Phosphoglycosyltransferase Enzymes.

    PubMed

    Das, Debasis; Walvoort, Marthe T C; Lukose, Vinita; Imperiali, Barbara

    2016-01-01

    Phosphoglycosyltransferases (PGTs) are families of integral membrane proteins with intriguingly diverse architectures. These enzymes function to initiate many important biosynthetic pathways including those leading to peptidoglycan, N-linked glycoproteins and lipopolysaccharide O-antigen. In spite of tremendous efforts, characterization of these enzymes remains a challenge not only due to the inherent difficulties associated with the purification of integral membrane proteins but also due to the limited availability of convenient assays. Current PGT assays include radioactivity-based methods, which rely on liquid-liquid or solid-liquid extractions, multienzyme systems linked to lactate dehydrogenase and NAD(+) generation, and HPLC-based approaches, all of which may suffer from low sensitivity and low throughput. Herein, we present the validation of a new luminescence-based assay (UMP-Glo) for measuring activities of PGT enzymes. This assay measures UMP, the by-product of PGT reactions, in a sensitive and quantitative manner by measuring the luminescence output in a discontinuous coupled assay system. The assay is rapid and robust in nature, and also compatible with microtiter plate formats. Activity and kinetic parameters of PglC, a PGT from Campylobacter jejuni, were quickly established using this assay. The efficacy of the assay was further corroborated using two different PGTs; PglC from Helicobacter pullorum and WecA from Thermatoga maritima. PMID:27624811

  1. A comparative molecular dynamics study of thermophilic and mesophilic β-fructosidase enzymes.

    PubMed

    Mazola, Yuliet; Guirola, Osmany; Palomares, Sucel; Chinea, Glay; Menéndez, Carmen; Hernández, Lázaro; Musacchio, Alexis

    2015-09-01

    Arabidopsis thaliana cell wall invertase 1 (AtcwINV1) and Thermotoga maritima β-fructosidase (BfrA) are among the best structurally studied members of the glycoside hydrolase family 32. Both enzymes hydrolyze sucrose as the main substrate but differ strongly in their thermal stability. Mesophilic AtcwINV1 and thermophilic BfrA have divergent sequence similarities in the N-terminal five bladed β-propeller catalytic domain (31 %) and the C-terminal β-sandwich domain (15 %) of unknown function. The two enzymes were subjected to 200 ns molecular dynamics simulations at 300 K (27 °C) and 353 K (80 °C). Regular secondary structure regions, but not loops, in AtcwINV1 and BfrA showed no significant fluctuation differences at both temperatures. BfrA was more rigid than AtcwINV1 at 300 K. The simulation at 353 K did not alter the structural stability of BfrA, but did increase the overall flexibility of AtcwINV1 exhibiting the most fluctuating regions in the β-propeller domain. The simulated heat treatment also increased the gyration radius and hydrophobic solvent accessible surface area of the plant enzyme, consistent with the initial steps of an unfolding process. The preservation of the conformational rigidity of BfrA at 353 K is linked to the shorter size of the protein loops. Shortening of BfrA loops appears to be a key mechanism for thermostability. PMID:26267297

  2. Site-selective dual modification of periplasmic binding proteins for sensing applications.

    PubMed

    Crochet, Amanda P; Kabir, Mohiuddin M; Francis, Matthew B; Paavola, Chad D

    2010-09-15

    We have developed three sensitive and specific amino acid sensors based on bacterial periplasmic solute binding proteins. A site-specific amino-terminal transamination reaction provides a useful complement to cysteine chemistry for the covalent modification of biomolecules in this application. We demonstrate this combination to attach two different chromophores to a single biomolecule in two locations. The periplasmic glutamine binding protein from E. coli was modified with a pair of dyes suitable for fluorescence resonance energy transfer, and this conjugate exhibited an l-glutamine dependent optical response. Two periplasmic binding proteins from the thermophilic organism Thermotoga maritima, for arginine and aliphatic amino acids, were modified and evaluated similarly. All three conjugates manifested signal changes mediated by resonant energy transfer upon binding their respective ligands, with nanomolar dissociation constants and stereochemical specificity. This represents a readily generalizable method for construction of reagentless biosensors. The double-labeling strategy was also exploited for the surface attachment of a dye-labeled glutamine binding protein via a biotin-streptavidin interaction.

  3. Thermal stability and binding energetics of thymidylate synthase ThyX.

    PubMed

    Krumova, Sashka; Todinova, Svetla; Tileva, Milena; Bouzhir-Sima, Latifa; Vos, Marten H; Liebl, Ursula; Taneva, Stefka G

    2016-10-01

    The bacterial thymidylate synthase ThyX is a multisubstrate flavoenzyme that takes part in the de novo synthesis of thymidylate in a variety of microorganisms. Herein we study the effect of FAD and dUMP binding on the thermal stability of wild type (WT) ThyX from the mesophilic Paramecium bursaria chlorella virus-1 (PBCV-1) and from the thermophilic bacterium Thermotoga maritima (TmThyX), and from two variants of TmThyX, Y91F and S88W, using differential scanning calorimetry. The energetics underlying these processes was characterized by isothermal titration calorimetry. The PBCV-1 protein is significantly less stable against the thermal challenge than the TmThyX WT. FAD exerted stabilizing effect greater for PBCV-1 than for TmThyX and for both mutants, whereas binding of dUMP to FAD-loaded proteins stabilized further only TmThyX. Different thermodynamic signatures describe the FAD binding to the WT ThyX proteins. While TmThyX binds FAD with a low μM binding affinity in a process characterized by a favorable entropy change, the assembly of PBCV-1 with FAD is governed by a large enthalpy change opposed by an unfavorable entropy change resulting in a relatively strong nM binding. An enthalpy-driven formation of a high affinity ternary ThyX/FAD/dUMP complex was observed only for TmThyX. PMID:27268384

  4. A thermostable exo-β-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-β-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

  5. Effects of Posidonia oceanica beach-cast on germination, growth and nutrient uptake of coastal dune plants.

    PubMed

    Del Vecchio, Silvia; Marbà, Núria; Acosta, Alicia; Vignolo, Clara; Traveset, Anna

    2013-01-01

    Seagrass meadows play an important role in marine ecosystems. A part of seagrass production is also exported to adjacent coastal terrestrial systems, possibly influencing their functioning. In this work we experimentally analyzed the effect of Posidonia oceanica beach-cast on plant germination, growth, and nutrient uptake of two plant species (Cakile maritima and Elymus farctus) that grow on upper beaches and fore dunes along the Mediterranean coasts. We compared plants growing in simple sand (control) with those growing in a substrate enriched with P. oceanica wrack (treatment) in laboratory. P. oceanica wrack doubled the N substrate pool and kept the substrate humid. Plants growing in the treated substrate grew faster, were twice as large as those growing in the control substrate, while tissues were enriched in N and P (Cakile by the 1.3 fold in N and 2.5 fold in P; Elymus by 1.5 fold in N and 2 fold in P). Our results suggest a positive effect of seagrass litter for the enhancing of dune species, highlighting its role for the conservation of coastal dune ecosystems.

  6. Expression patterns of Wnt genes in the venom claws of centipedes.

    PubMed

    Hayden, Luke; Arthur, Wallace

    2013-01-01

    The venom claws of centipedes, also known as forcipules, represent an evolutionary novelty that must have arisen in the centipede stem species, as they are not found in any other myriapods. The developmental-genetic changes that are involved in the origin of novelties are of considerable interest. It has previously been shown that centipede forcipules have a unique Hox code. However, this is a combinatorial code: no single Hox gene has a forcipule-specific expression. Here, we focus on Wnt genes. Two genes of this family show forcipule-specific expression in the "model centipede" Strigamia maritima: Wnt7 and Wnt11. For Wnt7, this forcipular expression zone seems to be a new one, which has arisen in evolution subsequently to other expression zones of the same gene. However, for Wnt11, the forcipule-specific expression probably arose by reduction of a more general pattern that originally included most or all of the limbs of an ancestral myriapod. Thus the developmental-genetic basis of the evolutionary change that turned the first pair of walking legs into venom claws is complex, involving different types of change in expression pattern. This sort of complexity is likely to be the case regarding evolutionary changes in morphology in general. Whether the origins of those features that can be considered as novelties are different in terms of their developmental-genetic basis from more routine evolutionary changes remains an open question. PMID:24074281

  7. Crystal Structures of Quinolinate Synthase in Complex with a Substrate Analogue, the Condensation Intermediate, and Substrate-Derived Product.

    PubMed

    Volbeda, Anne; Darnault, Claudine; Renoux, Oriane; Reichmann, Debora; Amara, Patricia; Ollagnier de Choudens, Sandrine; Fontecilla-Camps, Juan C

    2016-09-14

    The enzyme NadA catalyzes the synthesis of quinolinic acid (QA), the precursor of the universal nicotinamide adenine dinucleotide (NAD) cofactor. Here, we report the crystal structures of complexes between the Thermotoga maritima (Tm) NadA K219R/Y107F variant and (i) the first intermediate (W) resulting from the condensation of dihydroxyacetone phosphate (DHAP) with iminoaspartate and (ii) the DHAP analogue and triose-phosphate isomerase inhibitor phosphoglycolohydroxamate (PGH). In addition, using the TmNadA K219R/Y21F variant, we have reacted substrates and obtained a crystalline complex between this protein and the QA product. We also show that citrate can bind to both TmNadA K219R and its Y21F variant. The W structure indicates that condensation causes dephosphorylation. We propose that catalysis by the K219R/Y107F variant is arrested at the W intermediate because the mutated protein is unable to catalyze its aldo-keto isomerization and/or cyclization that ultimately lead to QA formation. Intriguingly, PGH binds to NadA with its phosphate group at the site where the carboxylate groups of W also bind. Our results shed significant light on the mechanism of the reaction catalyzed by NadA. PMID:27545412

  8. 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.

  9. A legacy of contrasting spatial genetic structure on either side of the Atlantic–Mediterranean transition zone in a marine protist

    PubMed Central

    Lowe, Chris D.; Martin, Laura E.; Montagnes, David J. S.; Watts, Phillip C.

    2012-01-01

    The mechanisms that underpin the varied spatial genetic structures exhibited by free-living marine microorganisms remain controversial, with most studies emphasizing a high dispersal capability that should redistribute genetic diversity in contrast to most macroorganisms whose populations often retain a genetic signature of demographic response to historic climate fluctuations. We quantified the European phylogeographic structure of the marine flagellate Oxyrrhis marina and found a marked difference in spatial genetic structure, population demography, and genetic diversity between the northwest Atlantic and Mediterranean Sea that reflects the persistent separation of these regions as well as context-dependent population responses to contrasting environments. We found similar geographic variation in the level of genetic diversity in the sister species Oxyrrhis maritima. Because the capacity for wide dispersal is not always realized, historic genetic footprints of range expansion and contraction persist in contemporary populations of marine microbes, as they do in larger species. Indeed, the well-described genetic effects of climatic variation on macroorganisms provide clear, testable hypotheses about the processes that drive genetic divergence in marine microbes and thus about the response to future environmental change. PMID:23213247

  10. Evidence for gene flow via seed dispersal from crop to wild relatives in Beta vulgaris (Chenopodiaceae): consequences for the release of genetically modified crop species with weedy lineages.

    PubMed Central

    Arnaud, J-F; Viard, F; Delescluse, M; Cuguen, J

    2003-01-01

    Gene flow and introgression from cultivated to wild plant populations have important evolutionary and ecological consequences and require detailed investigations for risk assessments of transgene escape into natural ecosystems. Sugar beets (Beta vulgaris ssp. vulgaris) are of particular concern because: (i) they are cross-compatible with their wild relatives (the sea beet, B. vulgaris ssp. maritima); (ii) crop-to-wild gene flow is likely to occur via weedy lineages resulting from hybridization events and locally infesting fields. Using a chloroplastic marker and a set of nuclear microsatellite loci, the occurrence of crop-to-wild gene flow was investigated in the French sugar beet production area within a 'contact-zone' in between coastal wild populations and sugar beet fields. The results did not reveal large pollen dispersal from weed to wild beets. However, several pieces of evidence clearly show an escape of weedy lineages from fields via seed flow. Since most studies involving the assessment of transgene escape from crops to wild outcrossing relatives generally focused only on pollen dispersal, this last result was unexpected: it points out the key role of a long-lived seed bank and highlights support for transgene escape via man-mediated long-distance dispersal events. PMID:12908976

  11. Mercury in sediments and vegetation in a moderately contaminated salt marsh (Tagus Estuary, Portugal).

    PubMed

    Canário, João; Vale, Carlos; Poissant, Laurier; Nogueira, Marta; Pilote, Martin; Branco, Vasco

    2010-01-01

    Depth variations of total mercury (Hg) and methylmercury (MeHg) concentrations were studied in cores from non-colonized sediments, sediments colonized by Halimione portulacoides, Sarcocorniafruticosa and Spartina maritima and belowground biomass, in a moderately contaminated salt marsh (Tagus Estuary, Portugal). Concentrations in belowground biomass exceeded up to 3 (Hg) and 15 (MeHg) times the levels in sediments, and up to 198 (Hg) and 308 (MeHg) times those found in aboveground parts. Methylmercury in colonized sediments reached 3% of the total Hg, 50 times above the maximum values found in non-colonized sediments. The absence of correlations between total Hg concentrations in sediments and the corresponding MeHg levels suggested that methylation was only dependent on the environmental and microbiological factors. The analysis of belowground biomass at high-depth resolution (2 cm) provided evidence that Hg and MeHg were actively absorbed from sediments, with higher enrichment factors at layers where higher microbial activity was probably occurring. The results obtained in this study indicated that the biotransformation of Hg to the toxic MeHg could increase the toxicity of plant-colonized sediments. PMID:21179951

  12. Structure-based design and screening of inhibitors for an essential bacterial GTPase, Der.

    PubMed

    Hwang, Jihwan; Tseitin, Vladimir; Ramnarayan, Kal; Shenderovich, Mark D; Inouye, Masayori

    2012-05-01

    Der is an essential and widely conserved GTPase that assists assembly of a large ribosomal subunit in bacteria. Der associates specifically with the 50S subunit in a GTP-dependent manner and the cells depleted of Der accumulate the structurally unstable 50S subunit, which dissociates into an aberrant subunit at a lower Mg(2+) concentration. As Der is an essential and ubiquitous protein in bacteria, it may prove to be an ideal cellular target against which new antibiotics can be developed. In the present study, we describe our attempts to identify novel antibiotics specifically targeting Der GTPase. We performed the structure-based design of Der inhibitors using the X-ray crystal structure of Thermotoga maritima Der (TmDer). Virtual screening of commercially available chemical library retrieved 257 small molecules that potentially inhibit Der GTPase activity. These 257 chemicals were tested for their in vitro effects on TmDer GTPase and in vivo antibacterial activities. We identified three structurally diverse compounds, SBI-34462, -34566 and -34612, that are both biologically active against bacterial cells and putative enzymatic inhibitors of Der GTPase homologs. We also presented the possible interactions of each compound with the Der GTP-binding site to understand the mechanism of inhibition. Therefore, our lead compounds inhibiting Der GTPase provide scaffolds for the development of novel antibiotics against antibiotic-resistant pathogenic bacteria. PMID:22377538

  13. Comparison of three ionic liquid-tolerant cellulases by molecular dynamics.

    PubMed

    Jaeger, Vance; Burney, Patrick; Pfaendtner, Jim

    2015-02-17

    We have employed molecular dynamics to investigate the differences in ionic liquid tolerance among three distinct family 5 cellulases from Trichoderma viride, Thermogata maritima, and Pyrococcus horikoshii. Simulations of the three cellulases were conducted at a range of temperatures in various binary mixtures of the ionic liquid 1-ethyl-3-methyl-imidazolium acetate with water. Our analysis demonstrates that the effects of ionic liquids on the enzymes vary in each individual case from local structural disturbances to loss of much of one of the enzyme's secondary structure. Enzymes with more negatively charged surfaces tend to resist destabilization by ionic liquids. Specific and unique structural changes in the enzymes are induced by the presence of ionic liquids. Disruption of the secondary structure, changes in dynamical motion, and local changes in the binding pocket are observed in less tolerant enzymes. Ionic-liquid-induced denaturation of one of the enzymes is indicated over the 500 ns timescale. In contrast, the most tolerant cellulase behaves similarly in water and in ionic-liquid-containing mixtures. Unlike the heuristic approaches that attempt to predict enzyme stability using macroscopic properties, molecular dynamics allows us to predict specific atomic-level structural and dynamical changes in an enzyme's behavior induced by ionic liquids and other mixed solvents. Using these insights, we propose specific experimentally testable hypotheses regarding the origin of activity loss for each of the systems investigated in this study. PMID:25692593

  14. A thermostable exo-β-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-β-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.

  15. Improving small-angle X-ray scattering data for structural analyses of the RNA world

    PubMed Central

    Rambo, Robert P.; Tainer, John A.

    2010-01-01

    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 tRNAval, and yeast tRNAphe 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

  16. Effects of ammonium and aluminium on the development and nutrition of Pinus nigra in hydroculture.

    PubMed

    Boxman, A W; Krabbendam, H; Bellemakers, M J; Roelofs, J G

    1991-01-01

    Application of ammonium and aluminium to young Pinus nigra var. maritima (Ait.) Melville trees resulted in a variety of negative effects. Excess ammonium led to an increase in shoot/root ratio. The biomass of the fine roots declined, resulting in an increase of the coarse/fine root ratio. The degree of mycorrhizal infection of the roots decreased. The nitrogen content of the trees increased considerably, whereas particularly the levels of calcium magnesium, manganese and zinc decreased sharply. Excess aluminium resulted in a simultaneous reduction of root and shoot biomass, a decline of the fine root system, an increase in the coarse/fine root ratio and a decrease in the degree of mycorrhizal infection. Uptake of the divalent cations calcium, magnesium, iron, manganese and zinc was restricted substantially, The nitrogen and phosphorus contents of the trees were hardly affected, whilst the potassium content of the shoot increased and of the roots decreased. This implicates that a deteriorating fine root system has to supply water and nutrients to a more demanding shoot. In the long term, high ammonium inputs and aluminium dissolution in forest ecosystems will lead to substantial nutrient deficiencies, just as has been found in the field. PMID:15092085

  17. Structural basis of ConM binding with resveratrol, an anti-inflammatory and antioxidant polyphenol.

    PubMed

    Rocha, Bruno A M; Teixeira, Claudener S; Silva-Filho, José C; Nóbrega, Raphael B; Alencar, Daniel B; Nascimento, Kyria S; Freire, Valder N; Gottfried, Carmem J S; Nagano, Celso S; Sampaio, Alexandre H; Saker-Sampaio, Silvana; Cavada, Benildo S; Delatorre, Plínio

    2015-01-01

    Resveratrol can also inhibit the activation of proinflammatory mediators and cytokines at the early gene expression stage. It is well known that lectins are sugar-binding proteins that act as both pro- and anti-inflammatory molecules. Thus, the objective of this work was to verify the binding of a polyphenol compound with a lectin of Canavalia maritima (ConM) based on their ability to inhibit pro-inflammatory processes. To accomplish this, ConM was purified and crystallized, and resveratrol was soaked at 5mM for 2h of incubation. The crystal belongs to the monoclinic space group C2, the final refinement resulted in an Rfactor of 16.0% and an Rfree of 25.5%. Resveratrol binds in the rigid β-sheet through H-bonds and hydrophobic interaction with amino acids that compose the fifth and sixth β-strands of the rigid β-sheet of ConM. The ConM and resveratrol inhibited DPPH oxidation, showing synergic activity with the most effective ratio of 2:3 and carbohydrate binding site is not directly related to antioxidant activity. It is the interaction between ConM and resveratrol that indicates the synergism of these two molecules in acting as free radicals scavengers and in reducing the inflammatory process through the inhibition of many pro-inflammatory events. PMID:25192853

  18. Crystal structure of the RNA component of bacterial ribonuclease P

    SciTech Connect

    Torres-Larios, Alfredo; Swinger, Kerren K.; Krasilnikov, Andrey S.; Pan, Tao; Mondragon, Alfonso

    2010-03-08

    Transfer RNA (tRNA) is produced as a precursor molecule that needs to be processed at its 3' and 5' ends. Ribonuclease P is the sole endonuclease responsible for processing the 5' end of tRNA by cleaving the precursor and leading to tRNA maturation. It was one of the first catalytic RNA molecules identified and consists of a single RNA component in all organisms and only one protein component in bacteria. It is a true multi-turnover ribozyme and one of only two ribozymes (the other being the ribosome) that are conserved in all kingdoms of life. Here we show the crystal structure at 3.85 {angstrom} resolution of the RNA component of Thermotoga maritima ribonuclease P. The entire RNA catalytic component is revealed, as well as the arrangement of the two structural domains. The structure shows the general architecture of the RNA molecule, the inter- and intra-domain interactions, the location of the universally conserved regions, the regions involved in pre-tRNA recognition and the location of the active site. A model with bound tRNA is in agreement with all existing data and suggests the general basis for RNA-RNA recognition by this ribozyme.

  19. Anaerobic High-Throughput Cultivation Method for Isolation of Thermophiles Using Biomass-Derived Substrates

    SciTech Connect

    Hamilton-Brehm, Scott; 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 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.

  20. Composition, abundance, biomass, and production of macrofauna in a New England estuary: comparisons among eelgrass meadows and other nursery habitats

    USGS Publications Warehouse

    Heck, K.L.; Able, K.W.; Roman, C.T.; Fahay, M.P.

    1995-01-01

    Quantitative suction sampling was used to characterize and compare the species composition, abundance, biomass, and secondary production of macrofauna inhabiting intertidal mudflat and sandflat, eelgrass meadow, and saltmarshpool habitats in the Nauset Marsh complex, Cape Cod, Massachusetts (USA). Species richness and abundance were often greatest in eelgrass habitat, as was macroinvertebrate biomass and production. Most striking was the five to fifteen times greater rate of annual macrofaunal production in eelgrass habitat than elsewhere, with values ranging from approximately 23139 g AFDW m super(2) yr super(1). The marsh pool containing widgeon grass (Ruppia maritima) supported surprisingly low numbers of macroinvertebrates, probably due to stressfully low dissolved oxygen levels at night during the summer. Two species of macroinvertebrates, blue mussels (Mytilus edulis) and to a lesser extent bay scallops (Argopecten irradians), used eelgrass as 'nursery habitat.' Calculations showed that macroinvertebrate production is proportionally much greater than the amount of primary production attributable to eelgrass in the Nauset Marsh system, and that dramatic changes at all trophic levels could be expected if large changes in seagrass abundance should occur. This work further underscores the extraordinarily large impact that seagrass can have on both the structure and function of estuarine ecosystems.

  1. Postglacial vegetation history of Orcas Island, northwestern Washington

    NASA Astrophysics Data System (ADS)

    Leopold, Estella B.; Dunwiddie, Peter W.; Whitlock, Cathy; Nickmann, Rudy; Watts, William A.

    2016-05-01

    The revegetation of islands following retreat of Pleistocene glaciers is of great biogeographical interest. The San Juan Islands, Washington, feature regionally distinctive xerophytic plant communities, yet their vegetation history, as it relates to past climate and sea level, is poorly known. We describe a 13,700-year-old pollen record from Killebrew Lake Fen and compare the vegetation reconstruction with others from the region. The data suggest that the narrow channels surrounding Orcas Island were not a barrier to early postglacial immigration of plants. Between 13,700 and 12,000 cal yr BP, Pinus, Tsuga, Picea, Alnus viridis, and possibly Juniperus maritima were present in a mosaic that supported Bison antiquus and Megalonyx. The rise of Alnus rubra-type pollen and Pteridium spores at ca. 12,000 cal yr BP suggests a warming trend and probably more fires. Temperate conifer taxa, including Cupressaceae, Pseudotsuga, Tsuga heterophylla, and Abies, increased after 11,000 cal yr BP and especially in the last 7000 cal yr BP. After 6000 cal yr BP, Pseudotsuga and Cupressaceae dominated the vegetation. The last 1500 yr were the wettest period of the record. Due to its rain shadow location, Orcas Island experienced drier conditions than on the mainland during most of the postglacial period.

  2. [Impacts of Ochotona pallasi disturbance on alpine grassland community characteristics].

    PubMed

    Zhao, Guo-qin; Li, Guang-yong; Ma, Wen-hu; Zhao, Dian-zhi; Li, Xiao-yan

    2013-08-01

    Plateau pika is the main fossorial mammal in the alpine grassland in Qinghai Lake Watershed of Northwest China. Based on the field investigation data from 18 alpine grassland quadrats in the Watershed, and by using redundancy analysis (RDA) and the surface fitting offered by 'R-Vegan' , the disturbance intensity of plateau pika (Ochotona pallasi) was classified as four levels. In order to explore the impacts of plateau pika disturbance on the alpine grassland ecosystem and its grazing quality, the community characteristics under different disturbance intensities by plateau pika were analyzed, and a conceptual model about the alpine grassland community succession was proposed. The results showed that with the increase of the disturbance intensity, the dominant species changed from Juncus roemerianus to Poa pratensis and Laux maritima. When the disturbance was small, the community had high quantitative values of coverage, aboveground biomass, biodiversity, and species richness, but the proportion of weeds was also high. When the disturbance was large, the quantitative values were the lowest, while the proportion of weeds was the highest. When the disturbance was moderate, the community had relatively high quantitative values, and the proportion of grasses and sedges was the highest. It was concluded that the community' s characteristic values under low plateau pika disturbance intensity were high but the grazing quality was low, while high disturbance intensity resulted in the grassland degradation. Therefore, the disturbance intensity in the threshold could maintain the stability of alpine grassland ecosystem and improve its grazing quality.

  3. Ritual plants of Muslim graveyards in northern Israel

    PubMed Central

    Dafni, Amots; Lev, Efraim; Beckmann, Sabine; Eichberger, Christian

    2006-01-01

    This article surveys the botanical composition of 40 Muslim graveyards in northern Israel, accompanied by an ethnobotanical study of the folkloristic traditions of the use of these plants in cemeteries. Three groups of plants were found to be repeated systematically and were also recognized for their ritual importance: aromatics herbs (especially Salvia fruticosa and Rosmarinus officinalis), white flowered plants (mainly Narcissus tazetta, Urginea maritima, Iris spp. and Pancratium spp.) and Cupressus sempervirens as the leading cemetery tree. As endemic use we can indicate the essential role of S. fruticosa as the main plant used in all human rites of passage symbolizing the human life cycle. The rosemary is of European origin while the use of basil is of Indian influence. The use of white flowers as cemeteries plants reflects an old European influence and almost the same species are used or their congeners. Most of the trees and shrubs that are planted in Muslim cemeteries in Israel have the same use in ancient as well in modern European cultures. In conclusion, our findings on the occurrence of plants in graveyards reflect the geographic situation of Israel as a crossroads in the cultural arena between Asia and Europe. Most of the traditions are common to the whole Middle East showing high relatedness to the classical world as well as to the present-day Europe. PMID:16961931

  4. High-resolution screening combined with HPLC-HRMS-SPE-NMR for identification of potential health-promoting constituents in sea aster and searocket--new Nordic food ingredients.

    PubMed

    Wubshet, Sileshi G; Schmidt, Jeppe S; Wiese, Stefanie; Staerk, Dan

    2013-09-11

    Sea aster (Aster tripolium L.) and searocket (Cakile maritima Scop.), potential ingredients in the New Nordic Diet, were analyzed by high-resolution radical scavenging and high-resolution α-glucosidase inhibition assays. Results from the two bioactivity profiles were used to guide subsequent structural analysis toward constituents with potential health-promoting effects. Structural analysis was performed by high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction and automated tube transfer nuclear magnetic resonance spectroscopy, that is, HPLC-HRMS-SPE-ttNMR. High-resolution mass spectrometry together with detailed analysis of one- and two-dimensional proton detected NMR experiments enabled unambiguous assignment of the targeted analytes. This revealed a series of caffeoyl esters (1, 2, 5), flavonoid glycosides (3, 4, 6, 11-15), flavonoids (7-9), sinapate esters (10, 16, 17), and sinapinic acid (18) associated with radical scavenging and/or α-glucosidase inhibition. In vitro assays implemented in this study showed that sea aster holds potential as a future functional food ingredient for lowering postprandial blood glucose level for diabetics, but further investigations are needed to prove the effect in vivo.

  5. Laūq: A Sustained-Release Dosage Form for Respiratory Disorders in Traditional Persian Medicine.

    PubMed

    Karegar-Borzi, Hossein; Salehi, Mehdi; Rahimi, Roja

    2016-01-01

    Laūq is a pharmaceutical dosage form that had been mainly used for the treatment of various respiratory disorders in traditional Persian medicine. It is important from 2 aspects: a dosage form with efficient and optimum delivery of drugs to the respiratory tract and biological effects of its ingredients. Natural medicine in laūq has been demonstrated to act in respiratory disorders by their antitussive, antiallergic, anti-inflammatory, antioxidant, spasmolytic, and antibacterial activities. Some of these natural remedies act by most of the mentioned mechanisms such as Cydonia oblonga, Glycyrrhiza glabra, Crocus sativus, Hyssopus officinalis, Foeniculum vulgare, and honey. However, the evidence is limited including Cassia fistula, Papaver somniferum, and Drimia maritima. According to positive pharmacokinetic and pharmacodynamic aspects of laūqs, they may be considered as efficient dosage forms for delivery of drugs to the respiratory tract. For better compatibility of patients, it could be substituted laūqs with newer drug delivery systems like lozenges. PMID:26008751

  6. A legacy of contrasting spatial genetic structure on either side of the Atlantic-Mediterranean transition zone in a marine protist.

    PubMed

    Lowe, Chris D; Martin, Laura E; Montagnes, David J S; Watts, Phillip C

    2012-12-18

    The mechanisms that underpin the varied spatial genetic structures exhibited by free-living marine microorganisms remain controversial, with most studies emphasizing a high dispersal capability that should redistribute genetic diversity in contrast to most macroorganisms whose populations often retain a genetic signature of demographic response to historic climate fluctuations. We quantified the European phylogeographic structure of the marine flagellate Oxyrrhis marina and found a marked difference in spatial genetic structure, population demography, and genetic diversity between the northwest Atlantic and Mediterranean Sea that reflects the persistent separation of these regions as well as context-dependent population responses to contrasting environments. We found similar geographic variation in the level of genetic diversity in the sister species Oxyrrhis maritima. Because the capacity for wide dispersal is not always realized, historic genetic footprints of range expansion and contraction persist in contemporary populations of marine microbes, as they do in larger species. Indeed, the well-described genetic effects of climatic variation on macroorganisms provide clear, testable hypotheses about the processes that drive genetic divergence in marine microbes and thus about the response to future environmental change.

  7. Temporal sampling helps unravel the genetic structure of naturally occurring populations of a phytoparasitic nematode. 1. Insights from the estimation of effective population sizes.

    PubMed

    Jan, Pierre-Loup; Gracianne, Cécile; Fournet, Sylvain; Olivier, Eric; Arnaud, Jean-François; Porte, Catherine; Bardou-Valette, Sylvie; Denis, Marie-Christine; Petit, Eric J

    2016-03-01

    The sustainability of modern agriculture relies on strategies that can control the ability of pathogens to overcome chemicals or genetic resistances through natural selection. This evolutionary potential, which depends partly on effective population size (N e ), is greatly influenced by human activities. In this context, wild pathogen populations can provide valuable information for assessing the long-term risk associated with crop pests. In this study, we estimated the effective population size of the beet cyst nematode, Heterodera schachtii, by sampling 34 populations infecting the sea beet Beta vulgaris spp. maritima twice within a one-year period. Only 20 populations produced enough generations to analyze the variation in allele frequencies, with the remaining populations showing a high mortality rate of the host plant after only 1 year. The 20 analyzed populations showed surprisingly low effective population sizes, with most having N e close to 85 individuals. We attribute these low values to the variation in population size through time, systematic inbreeding, and unbalanced sex-ratios. Our results suggest that H. schachtii has low evolutionary potential in natural environments. Pest control strategies in which populations on crops mimic wild populations may help prevent parasite adaptation to host resistance. PMID:26989440

  8. Cloning and Expression Analysis of a Gene Encoding for Ascorbate Peroxidase and Responsive to Salt Stress in Beet (Beta vulgaris).

    PubMed

    Dunajska-Ordak, Kamila; Skorupa-Kłaput, Monika; Kurnik, Katarzyna; Tretyn, Andrzej; Tyburski, Jarosław

    2014-01-01

    BvpAPX is a full-length cDNA-encoding peroxisomal ascorbate peroxidase isolated from leaves of salt-stressed beet (Beta vulgaris) plants. A high level of identity has been reported between the deduced amino acid sequence of BvpAPX and other known ascorbate peroxidases. The genomic sequence of BvpAPX revealed a gene composed of 5 exons and 4 introns. Several sequence motifs revealed in the 5'UTR region of the gene confer to BvpAPX a putative responsiveness to various abiotic stresses. We determined the effect of salt stress on BvpAPX expression in leaves of the cultivated beet varieties, Huzar and Janosik, and their wild salt-tolerant relative B. vulgaris ssp. maritima. Plants were subjected to salt stress during a 32-day culture period (long-term salt treatment). An alternative salinization protocol consisted of an 18-h incubation of detached beet leaves in media supplemented with toxic salt concentrations (short-term salt treatment). RT-Q-PCR analysis revealed that BvpAPX expression markedly increased in leaves of plants subjected to conditions of long-term treatment with salinity, whereas BvpAPX transcript levels remained unaffected in detached leaves during short-term salt treatment. In addition, several leaf redox system parameters, such as ascorbate peroxidase activity or ascorbic acid, hydrogen peroxide, and lipid hydroperoxide concentration, were determined in the leaves of beet plants subjected to salt stress conditions. PMID:24465083

  9. A new source of cytoplasmic male sterility found in wild beet and its relationship to other CMS types.

    PubMed

    Kawanishi, Yuki; Shinada, Hiroshi; Matsunaga, Muneyuki; Masaki, Yusuke; Mikami, Tetsuo; Kubo, Tomohiko

    2010-04-01

    We found a number of male-sterile plants in a wild beet (Beta vulgaris L. subsp. maritima) accession line, FR4-31. The inheritance study of the male sterility indicated the trait to be of the cytoplasmic type. The mitochondrial genome of FR4-31 proved to lack the male-sterility-associated genes preSatp6 and orf129, which are characteristic of the Owen CMS and I-12CMS(3) cytoplasms of beets, respectively. Instead, the truncated cox2 gene involved in G CMS originating from wild beets was present in the FR4-31 mitochondrial genome. In Southern hybridization using four mitochondrial gene probes, the FR4-31 cytoplasm showed patterns similar to those typical of the G cytoplasm. It is thus likely that the FR4-31 cytoplasm has a different CMS mechanism from both Owen CMS and I-12CMS(3), and that the FR4-31 and G cytoplasms resemble each other closely. A restriction map of the FR4-31 mitochondrial DNA was generated and aligned with those published for the Owen and normal fertile cytoplasms. The FR4-31 mitochondrial genome was revealed to differ extensively in arrangement from the Owen and normal genomes, and the male-sterile Owen and FR4-31 genomes seem to be derived independently from an ancestral genome. PMID:20616856

  10. 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.

  11. Temporal sampling helps unravel the genetic structure of naturally occurring populations of a phytoparasitic nematode. 2. Separating the relative effects of gene flow and genetic drift.

    PubMed

    Gracianne, Cécile; Jan, Pierre-Loup; Fournet, Sylvain; Olivier, Eric; Arnaud, Jean-François; Porte, Catherine; Bardou-Valette, Sylvie; Denis, Marie-Christine; Petit, Eric J

    2016-09-01

    Studying wild pathogen populations in natural ecosystems offers the opportunity to better understand the evolutionary dynamics of biotic diseases in crops and to enhance pest control strategies. We used simulations and genetic markers to investigate the spatial and temporal population genetic structure of wild populations of the beet cyst nematode Heterodera schachtii on a wild host plant species, the sea beet (Beta vulgaris spp. maritima), the wild ancestor of cultivated beets. Our analysis of the variation of eight microsatellite loci across four study sites showed that (i) wild H. schachtii populations displayed fine-scaled genetic structure with no evidence of substantial levels of gene flow beyond the scale of the host plant, and comparisons with simulations indicated that (ii) genetic drift substantially affected the residual signals of isolation-by-distance processes, leading to departures from migration-drift equilibrium. In contrast to what can be suspected for (crop) field populations, this showed that wild cyst nematodes have very low dispersal capabilities and are strongly disconnected from each other. Our results provide some key elements for designing pest control strategies, such as decreasing passive dispersal events to limit the spread of virulence among field nematode populations.

  12. Screening of 18 species for digestate phytodepuration.

    PubMed

    Pavan, Francesca; Breschigliaro, Simone; Borin, Maurizio

    2015-02-01

    This experiment assesses the aptitude of 18 species in treating the digestate liquid fraction (DLF) in a floating wetland treatment system. The pilot system was created in NE Italy in 2010 and consists of a surface-flow system with 180 floating elements (Tech-IA®) vegetated with ten halophytes and eight other wetland species. The species were transplanted in July 2011 in basins filled with different proportions of DLF/water (DLF/w); periodic increasing of the DLF/w ratio was imposed after transplanting, reaching the worst conditions for plants in summer 2012 (highest EC value 7.3 mS cm/L and NH4-N content 225 mg/L). It emerged that only Cynodon dactylon, Typha latifolia, Elytrigia atherica, Halimione portulacoides, Salicornia fruticosa, Artemisia caerulescens, Spartina maritima and Puccinellia palustris were able to survive under the system conditions. Halophytes showed higher dry matter production than other plants. The best root development (up to 40-cm depth) was recorded for Calamagrostis epigejos, Phragmites australis, T. latifolia and Juncus maritimus. The highest nitrogen (10-15 g/m(2)) and phosphorus (1-4 g/m(2)) uptakes were obtained with P. palustris, Iris pseudacorus and Aster tripolium. In conclusion, two halophytes, P. palustris and E. atherica, present the highest potential to be used to treat DLF in floating wetlands.

  13. FtsA forms actin-like protofilaments

    PubMed Central

    Szwedziak, Piotr; Wang, Qing; Freund, Stefan MV; Löwe, Jan

    2012-01-01

    FtsA is an early component of the Z-ring, the structure that divides most bacteria, formed by tubulin-like FtsZ. FtsA belongs to the actin family of proteins, showing an unusual subdomain architecture. Here we reconstitute the tethering of FtsZ to the membrane via FtsA's C-terminal amphipathic helix in vitro using Thermotoga maritima proteins. A crystal structure of the FtsA:FtsZ interaction reveals 16 amino acids of the FtsZ tail bound to subdomain 2B of FtsA. The same structure and a second crystal form of FtsA reveal that FtsA forms actin-like protofilaments with a repeat of 48 Å. The identical repeat is observed when FtsA is polymerized using a lipid monolayer surface and FtsAs from three organisms form polymers in cells when overexpressed, as observed by electron cryotomography. Mutants that disrupt polymerization also show an elongated cell division phenotype in a temperature-sensitive FtsA background, demonstrating the importance of filament formation for FtsA's function in the Z-ring. PMID:22473211

  14. Cloning of the Gene Encoding a Novel Thermostable α-Galactosidase from Thermus brockianus ITI360

    PubMed Central

    Fridjonsson, Olafur; Watzlawick, Hildegard; Gehweiler, Axel; Rohrhirsch, Thilo; Mattes, Ralf

    1999-01-01

    An α-galactosidase gene from Thermus brockianus ITI360 was cloned, sequenced, and expressed in Escherichia coli, and the recombinant protein was purified. The gene, designated agaT, codes for a 476-residue polypeptide with a calculated molecular mass of 53,810 Da. The native structure of the recombinant enzyme (AgaT) was estimated to be a tetramer. AgaT displays amino acid sequence similarity to the α-galactosidases of Thermotoga neapolitana and Thermotoga maritima and a low-level sequence similarity to α-galactosidases of family 36 in the classification of glycosyl hydrolases. The enzyme is thermostable, with a temperature optimum of activity at 93°C with para-nitrophenyl-α-galactopyranoside as a substrate. Half-lives of inactivation at 92 and 80°C are 100 min and 17 h, respectively. The pH optimum is between 5.5 and 6.5. The enzyme displayed high affinity for oligomeric substrates. The Kms for melibiose and raffinose at 80°C were determined as 4.1 and 11.0 mM, respectively. The α-galactosidase gene in T. brockian