Sample records for attenuata sipk wipk

  1. Reactive oxygen species in signalling the transcriptional activation of WIPK expression in tobacco. (United States)

    Xu, Juan; Yang, Kwang-Yeol; Yoo, Seung Jin; Liu, Yidong; Ren, Dongtao; Zhang, Shuqun


    Plant mitogen-activated protein kinases represented by tobacco WIPK (wounding-induced protein kinase) and its orthologs in other species are unique in their regulation at transcriptional level in response to stress and pathogen infection. We previously demonstrated that transcriptional activation of WIPK is essential for induced WIPK activity, and activation of salicylic acid-induced protein kinase (SIPK) by the constitutively active NtMEK2(DD) is sufficient to induce WIPK gene expression. Here, we report that the effect of SIPK on WIPK gene expression is mediated by reactive oxygen species (ROS). Using a combination of pharmacological and gain-of-function transgenic approaches, we studied the relationship among SIPK activation, WIPK gene activation in response to fungal cryptogein, light-dependent ROS generation in chloroplasts, and ROS generated via NADPH oxidase. In the conditional gain-of-function GVG-NtMEK2(DD) transgenic tobacco, induction of WIPK expression is dependent on the ROS generation in chloroplasts. Consistently, methyl viologen, an inducer of ROS generation in chloroplasts, highly activated WIPK expression. In addition to chloroplast-originated ROS, H(2)O(2) generated from the cell-surface NADPH oxidase could also activate WIPK gene expression, and inhibition of cryptogein-induced ROS generation also abolished WIPK gene activation. Our data demonstrate that WIPK gene activation is mediated by ROS, which provides a mechanism by which ROS influence cellular signalling processes in plant stress/defence response.

  2. Phytochemical and biological studies of Agave attenuata. (United States)

    Rizwan, Komal; Zubair, Muhammad; Rasool, Nasir; Riaz, Muhammad; Zia-Ul-Haq, Muhammad; de Feo, Vincenzo


    The present study was conducted to examine various biological activities of a methanol extract of Agave attenuata leaves. GC-MS analysis of the n-hexane fraction from the extract revealed the presence of 31 compounds, with mono-2-ethylhexyl phthalate (11.37%), 1,2-benzenedicarboxylic acid (6.33%), n-docosane (6.30%) and eicosane (6.02%) as the major components. The leaves contained appreciable levels of total phenolic contents (10.541-39.35 GAE, mg/100 g) and total flavonoid contents (43.35-304.8 CE, mg/100 g). The extract and some of its fractions showed moderate antimicrobial effects. Leaves extract and fractions also exhibited a good antioxidant potential when measured by DPPH radical scavenging activity and inhibition of lipid peroxidation assays. The hemolytic effect of the plant was found to be in a range of 1.01%-2.64%. From the present study it is concluded that this plant could be used as a source of natural antioxidants and functional food nutraceutical applications.

  3. Cutaneous Phaeohyphomycosis Caused by Exophiala attenuata in a Domestic Cat. (United States)

    Overy, David P; Martin, Chelsea; Muckle, Anne; Lund, Lorraine; Wood, Jill; Hanna, Paul


    A 7-year-old female-spayed, domestic short-haired cat was presented to her veterinarian with a mass on the hind paw. Histopathologic examination of a tissue biopsy revealed nodular pyogranulomatous panniculitis with intralesional pigmented fungal hyphae. A dematiaceous fungal isolate was isolated with a micromorphological phenotype consistent with the anamorphic genus Exophiala: budding cells, torulose mycelium and annellidic conidiogenesis from simple conidiophores consisting of terminal and lateral cells that tapered to a short beak at the apex. Sequence homology of the internal transcribed spacer region of the rDNA gene confirmed the identification of the isolate as Exophiala attenuata. Reported here is the first confirmed case of feline phaeohyphomycosis caused by E. attenuata in North America. Similar to historical cases of feline phaeohyphomycosis caused by Exophiala spp., there was no history or postmortem evidence to suggest the patient was in an immunocompromised state (e.g., suffering from FeLV or FIV). Although aggressive surgical excision of local lesions is recommended prior to drug treatment when dealing with subcutaneous phaeohyphomycosis, surgery followed by itraconazole treatment did not resolve the E. attenuata infection in this cat.

  4. Host-plant-mediated effects of Nadefensin on herbivore and pathogen resistance in Nicotiana attenuata

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    Baldwin Ian T


    Full Text Available Abstract Background The adage from Shakespeare, "troubles, not as single spies, but in battalions come," holds true for Nicotiana attenuata, which is commonly attacked by both pathogens (Pseudomonas spp. and herbivores (Manduca sexta in its native habitats. Defense responses targeted against the pathogens can directly or indirectly influence the responses against the herbivores. Nadefensin is an effective induced defense gene against the bacterial pathogen Pseudomonas syringae pv tomato (PST DC3000, which is also elicited by attack from M. sexta larvae, but whether this defense protein influences M. sexta's growth and whether M. sexta-induced Nadefensin directly or indirectly influences PST DC3000 resistance are unknown. Results M. sexta larvae consumed less on WT and on Nadefensin-silenced N. attenuata plants that had previously been infected with PST DC3000 than on uninfected plants. WT plants infected with PST DC3000 showed enhanced resistance to PST DC3000 and decreased leaf consumption by M. sexta larvae, but larval mass gain was unaffected. PST DC3000-infected Nadefensin-silenced plants were less resistant to subsequent PST DC3000 challenge, and on these plants, M. sexta larvae consumed less and gained less mass. WT and Nadefensin-silenced plants previously damaged by M. sexta larvae were better able to resist subsequent PST DC3000 challenges than were undamaged plants. Conclusion These results demonstrate that Na-defensin directly mediates defense against PST DC3000 and indirectly against M. sexta in N. attenuata. In plants that were previously infected with PST DC3000, the altered leaf chemistry in PST DC3000-resistant WT plants and PST DC3000-susceptible Nadefensin-silenced plants differentially reduced M. sexta's leaf consumption and mass gain. In plants that were previously damaged by M. sexta, the combined effect of the altered host plant chemistry and a broad spectrum of anti-herbivore induced metabolomic responses was more

  5. Digestive duet: Midgut digestive proteinases of Manduca sexta ingesting Nicotiana attenuata with manipulated trypsin proteinase inhibitor expression

    NARCIS (Netherlands)

    Zavala, J.A.; Giri, A.P.; Jongsma, M.A.; Baldwin, I.T.


    The defensive effect of endogenous trypsin proteinase inhibitors (NaTPIs) on the herbivore Manduca sexta was demonstrated by genetically altering NaTPI production in M. sexta's host plant, Nicotiana attenuata. To understand how this defense works, we studied the effects of NaTPI on M. sexta gut prot

  6. The effects of dopamine synthesis inhibitors and dopamine antagonists on regeneration in the hydra Hydra attenuata. (United States)

    Ostroumova, T V; Markova, L N


    The effects of catecholamine synthesis inhibitors (alpha-methyltyrosine, 3-iodotyrosine, and alpha-methyl-DOPA) and dopamine receptor blockers (haloperidol and spiperone) on the regeneration of apical, gastral, and basal fragments of the hydra Hydra attenuata were studied. These experiments showed that alpha-methyltyrosine and 3-iodotyrosine significantly inhibited regeneration but did not produce morphological anomalies. Alpha-Methyl-DOPA produce less inhibition of regeneration, but induced ectopic tentacles and outgrowths in gastral regenerates. Haloperidol and spiperone had no significant effect on the rate of regeneration but induced significant numbers of morphogenetic anomalies in gastral regenerates. Apical and basal regenerates, which retained their natural organizers (the head and base respectively) never yielded morphogenetic anomalies in the presence of either dopamine receptor blockers or dopamine synthesis inhibitors. The possible role of neurotransmitters. particularly dopamine, in morphogenesis in hydras is discussed.

  7. Allometric analysis of the induced flavonols on the leaf surface of wild tobacco (Nicotiana attenuata). (United States)

    Roda, Amy L; Oldham, Neil J; Svatos, Ales; Baldwin, Ian T


    Trichomes excrete secondary metabolites that may alter the chemical composition of the leaf surface, reducing damage caused by herbivores, pathogens and abiotic stresses. We examined the surface exudates produced by Nicotiana attenuata Torr. Ex Wats., a plant known to contain and secrete a number of secondary metabolites that are toxic or a deterrent to herbivorous insects. Extractions specific to the leaf surface, the trichomes, and the laminar components demonstrated the localization of particular compounds. Diterpene glycosides occurred exclusively in leaf mesophyll, whereas nicotine was found in both the trichomes and mesophyll. Neither rutin nor nicotine was found on the leaf surface. Quercetin and 7 methylated derivatives were found in the glandular trichomes and appeared to be excreted onto the leaf surface. We examined the elicitation of these flavonols on the leaf surface with a surface-area allometric analysis, which measures changes in metabolites independent of the effects of leaf expansion. The flavonols responded differently to wounding, methyl jasmonate (MeJA), herbivore attack and UV-C radiation, and the response patterns corresponded to their compound-specific allometries. Finding greater amounts of quercetin on younger leaves and reduced amounts after herbivore feeding and MeJA treatment, we hypothesized that quercetin may function as an attractant, helping the insects locate a preferred feeding site. Consistent with this hypothesis, mirids (Tupiocoris notatus) were found more often on mature leaves sprayed with quercetin at a concentration typical of young leaves than on unsupplemented mature leaves. The composition of metabolites on the leaf surface of N. attenuata changes throughout leaf development and in response to herbivore attack or environmental stress, and these changes are mediated in part by responses of the glandular trichomes.

  8. HSPRO controls early Nicotiana attenuata seedling growth during interaction with the fungus Piriformospora indica. (United States)

    Schuck, Stefan; Camehl, Iris; Gilardoni, Paola A; Oelmueller, Ralf; Baldwin, Ian T; Bonaventure, Gustavo


    In a previous study aimed at identifying regulators of Nicotiana attenuata responses against chewing insects, a 26-nucleotide tag matching the HSPRO (ORTHOLOG OF SUGAR BEET Hs1(pro)(-)(1)) gene was found to be strongly induced after simulated herbivory (Gilardoni et al., 2010). Here we characterized the function of HSPRO during biotic interactions in transgenic N. attenuata plants silenced in its expression (ir-hspro). In wild-type plants, HSPRO expression was not only induced during simulated herbivory but also when leaves were inoculated with Pseudomonas syringae pv tomato DC3000 and roots with the growth-promoting fungus Piriformospora indica. Reduced HSPRO expression did not affect the regulation of direct defenses against Manduca sexta herbivory or P. syringae pv tomato DC3000 infection rates. However, reduced HSPRO expression positively influenced early seedling growth during interaction with P. indica; fungus-colonized ir-hspro seedlings increased their fresh biomass by 30% compared with the wild type. Grafting experiments demonstrated that reduced HSPRO expression in roots was sufficient to induce differential growth promotion in both roots and shoots. This effect was accompanied by changes in the expression of 417 genes in colonized roots, most of which were metabolic genes. The lack of major differences in the metabolic profiles of ir-hspro and wild-type colonized roots (as analyzed by liquid chromatography time-of-flight mass spectrometry) suggested that accelerated metabolic rates were involved. We conclude that HSPRO participates in a whole-plant change in growth physiology when seedlings interact with P. indica.

  9. First record of Pantropical spotted dolphins Stenella attenuata in the Yellow Sea, China (United States)

    Wu, Fuxing; Wang, Xianyan; Zhang, Qiuxia; Miao, Xing; Zhang, Ting; Zhu, Qian


    On October 1, 2009, sixteen dolphins were obtained from fishermen by incidental catching in the Yellow Sea, China. As the dolphins' skin color was ambiguous, morphological parameters were measured, and mitochondrial DNA cytochrome b (Cyt b) gene sequence was studied to identify the species. Morphological characteristics were consistent with Pantropical spotted dolphins, Stenella attenuata. Furthermore, a partial mitochondrial DNA cytochrome b (Cyt b) gene sequence as long as 328-bp was studied by extracting genomic DNA from the skins, and six haplotypes were detected in the sixteen dolphins. By comparing homologous sequences available in GenBank (, all the six haplotypes had maximal genetic similarity with Pantropical spotted dolphin. Eight species of cetacean (whales and dolphins) are now recognised in the Yellow Sea. To the best of our knowledge, this is the first record of Pantropical spotted dolphins from this region. Despite this species being listed as a Grade II National Key Protected Animal since 1988, little is known of its biology in Chinese waters. We recommend remedial research be undertaken to ensure appropriate management.

  10. Rapid modification of the insect elicitor N-linolenoyl-glutamate via a lipoxygenase-mediated mechanism on Nicotiana attenuata leaves

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    VanDoorn Arjen


    Full Text Available Abstract Background Some plants distinguish mechanical wounding from herbivore attack by recognizing specific constituents of larval oral secretions (OS which are introduced into plant wounds during feeding. Fatty acid-amino acid conjugates (FACs are major constituents of Manduca sexta OS and strong elicitors of herbivore-induced defense responses in Nicotiana attenuata plants. Results The metabolism of one of the major FACs in M. sexta OS, N-linolenoyl-glutamic acid (18:3-Glu, was analyzed on N. attenuata wounded leaf surfaces. Between 50 to 70% of the 18:3-Glu in the OS or of synthetic 18:3-Glu were metabolized within 30 seconds of application to leaf wounds. This heat-labile process did not result in free α-linolenic acid (18:3 and glutamate but in the biogenesis of metabolites both more and less polar than 18:3-Glu. Identification of the major modified forms of this FAC showed that they corresponded to 13-hydroxy-18:3-Glu, 13-hydroperoxy-18:3-Glu and 13-oxo-13:2-Glu. The formation of these metabolites occurred on the wounded leaf surface and it was dependent on lipoxygenase (LOX activity; plants silenced in the expression of NaLOX2 and NaLOX3 genes showed more than 50% reduced rates of 18:3-Glu conversion and accumulated smaller amounts of the oxygenated derivatives compared to wild-type plants. Similar to 18:3-Glu, 13-oxo-13:2-Glu activated the enhanced accumulation of jasmonic acid (JA in N. attenuata leaves whereas 13-hydroxy-18:3-Glu did not. Moreover, compared to 18:3-Glu elicitation, 13-oxo-13:2-Glu induced the differential emission of two monoterpene volatiles (β-pinene and an unidentified monoterpene in irlox2 plants. Conclusions The metabolism of one of the major elicitors of herbivore-specific responses in N. attenuata plants, 18:3-Glu, results in the formation of oxidized forms of this FAC by a LOX-dependent mechanism. One of these derivatives, 13-oxo-13:2-Glu, is an active elicitor of JA biosynthesis and differential

  11. Herbivore induction of jasmonic acid and chemical defences reduce photosynthesis in Nicotiana attenuata. (United States)

    Nabity, Paul D; Zavala, Jorge A; DeLucia, Evan H


    Herbivory initiates a shift in plant metabolism from growth to defence that may reduce fitness in the absence of further herbivory. However, the defence-induced changes in carbon assimilation that precede this reallocation in resources remain largely undetermined. This study characterized the response of photosynthesis to herbivore induction of jasmonic acid (JA)-related defences in Nicotiana attenuata to increase understanding of these mechanisms. It was hypothesized that JA-induced defences would immediately reduce the component processes of photosynthesis upon attack and was predicted that wild-type plants would suffer greater reductions in photosynthesis than plants lacking JA-induced defences. Gas exchange, chlorophyll fluorescence, and thermal spatial patterns were measured together with the production of defence-related metabolites after attack and through recovery. Herbivore damage immediately reduced electron transport and gas exchange in wild-type plants, and gas exchange remained suppressed for several days after attack. The sustained reductions in gas exchange occurred concurrently with increased defence metabolites in wild-type plants, whereas plants lacking JA-induced defences suffered minimal suppression in photosynthesis and no increase in defence metabolite production. This suppression in photosynthesis occurred only after sustained defence signalling and defence chemical mobilization, whereas a short bout of feeding damage only transiently altered components of photosynthesis. It was identified that lipoxygenase signalling interacted with photosynthetic electron transport and that the resulting JA-related metabolites reduced photosynthesis. These data represent a metabolic cost to mounting a chemical defence against herbivory and link defence-signalling networks to the differential effects of herbivory on photosynthesis in remaining leaf tissues in a time-dependent manner.

  12. High levels of jasmonic acid antagonize the biosynthesis of gibberellins and inhibit the growth of Nicotiana attenuata stems. (United States)

    Heinrich, Maria; Hettenhausen, Christian; Lange, Theo; Wünsche, Hendrik; Fang, Jingjing; Baldwin, Ian T; Wu, Jianqiang


    Hormones play pivotal roles in regulating plant development, growth, and stress responses, and cross-talk among different hormones fine-tunes various aspects of plant physiology. Jasmonic acid (JA) is important for plant defense against herbivores and necrotic fungi and also regulates flower development; in addition, Arabidopsis mutants over-producing JA usually have stunted stems and wound-induced jasmonates suppress Arabidopsis growth, suggesting that JA is also involved in stem elongation. Gibberellins (GAs) promote stem and leaf growth and modulate seed germination, flowering time, and the development of flowers, fruits, and seeds. However, little is known about the interaction between the JA and GA pathways. Two calcium-dependent protein kinases, CDPK4 and CDPK5, are important suppressors of JA accumulation in a wild tobacco species, Nicotiana attenuata. The stems of N. attenuata silenced in CDPK4 and CDPK5 (irCDPK4/5 plants) had dramatically increased levels of JA and exhibited stunted elongation and had very high contents of secondary metabolites. Genetic analysis indicated that the high JA levels in irCDPK4/5 stems accounted for the suppressed stem elongation and the accumulation of secondary metabolites. Supplementation of GA(3) to irCDPK4/5 plants largely restored normal stem growth to wild-type levels. Measures of GA levels indicated that over-accumulation of JA in irCDPK4/5 stems inhibited the biosynthesis of GAs. Finally, we show that JA antagonizes GA biosynthesis by strongly inhibiting the transcript accumulation of GA20ox and possibly GA13ox, the key genes in GA production, demonstrating that high JA levels antagonize GA biosynthesis in stems.

  13. Larvicidal activities of Knema attenuata (Hook. f. & Thomson) Warb. (Myristicaceae) extracts against Aedes albopictus Skuse and Anopheles stephensi Liston. (United States)

    Vinayachandra; Shwetha, R; Chandrashekar, K R


    In recent years, uses of environment friendly and biodegradable natural insecticides of plant origin have received renewed attention as agents for vector control. The present study was undertaken to investigate the effect of aril and kernel extracts of Knema attenuata (Hook. f. & Thomson) Warb. (Myristicaceae) on larvae of Aedes albopictus Skuse and Anopheles stephensi Liston under laboratory conditions. The aril was extracted with chloroform and ethanol; the kernel was extracted with ethanol and hexane. The extracts were tested against the 3rd-4th instar larvae collected from Bunder area, Mangalore, India, which is a well-known fishing harbour, where several mosquito-borne diseases were reported. All the graded concentrations (100, 200, 300, 400 and 500 ppm) showed significant larval mortality after 24 h of observation. Chloroform extracts of aril showed 100% mortality against both larval forms of A. albopictus and A. stephensi at the concentration of 500 ppm. Among the extracts tested, chloroform extracts of aril and ethanol extracts of kernel exhibited higher toxicity against both A. albopictus (LC(50), 141 ppm and 159 ppm; LC(90), 290 ppm and 342 ppm) and A. stephensi (LC(50), 160 ppm and 162 ppm; LC90, 445 ppm and 458 ppm). Hexane extracts of kernel exhibited least toxicity against A. albopictus (LC50, 239 ppm; LC(90), 484 ppm), whereas ethanol extracts of aril showed the least toxicity against A. stephensi (LC(50), 290; LC(90), 498). A preliminary phytochemical assay revealed the presence of phenolics, tannins, steroids, terpenes, resins, and glycolipids in all the extracts. Alkaloids, flavonoids and saponins were absent. The lower LC(50) value of the chloroform extracts of K. attenuata aril indicates its potentiality as a larvicide against A. albopictus and A. stephensi mosquito larvae.

  14. Multi-scale biomarker evaluation of the toxicity of a commercial azo dye (Disperse Red 1) in an animal model, the freshwater cnidarian Hydra attenuata. (United States)

    de Jong, Laetitia; Pech, Nicolas; de Aragão Umbuzeiro, Gisela; Moreau, Xavier


    Acute (24 h, 48 h, 72 h) and chronic (7 days) tests have been performed to evaluate the effects of the commercial azo dye Disperse Red 1 (DR1) using various biomarkers in the freshwater invertebrate Hydra attenuata. Morphological changes have been selected to calculate ecotoxicological thresholds for sublethal and lethal DR1 concentrations. A multinomial logistic model showed that the probability of each morphological stage occurrence was function of concentration, time and interaction between both. Results of oxidative balance parameter measurements (72 h and 7 days) suggest that polyps set up defense mechanisms to limit lipid peroxidation caused by DR1. DR1 exposure at hormetic concentrations induces increase of asexual reproductive rates. This result suggests (1) an impact on the fitness-related phenotypical traits and (2) trade-offs between reproduction and maintenance to allow the population to survive harsher conditions. Changes in serotonin immuno-labeling in polyps showing alterations in feeding behavior suggest that chronic DR1 exposure impaired neuronal processes related to ingesting behavior in H. attenuata. This ecotoxicity study sheds light on the possible serotonin function in Hydra model and reports for the first time that serotonin could play a significant role in feeding behavior. This study used a multi-scale biomarker approach investigating biochemical, morphological, reproductive and behavioral endpoints in Hydra attenuata. This organism is proposed for a pertinent animal model to assess ecotoxicological impact of pollutant mixtures in freshwater environment.

  15. Jasmonate and ppHsystemin Regulate Key Malonylation Steps in the Biosynthesis of 17-Hydroxygeranyllinalool Diterpene Glycosides, an Abundant and Effective Direct Defense against Herbivores in Nicotiana attenuata[W (United States)

    Heiling, Sven; Schuman, Meredith C.; Schoettner, Matthias; Mukerjee, Purba; Berger, Beatrice; Schneider, Bernd; Jassbi, Amir R.; Baldwin, Ian T.


    We identified 11 17-hydroxygeranyllinalool diterpene glycosides (HGL-DTGs) that occur in concentrations equivalent to starch (mg/g fresh mass) in aboveground tissues of coyote tobacco (Nicotiana attenuata) and differ in their sugar moieties and malonyl sugar esters (0-2). Concentrations of HGL-DTGs, particularly malonylated compounds, are highest in young and reproductive tissues. Within a tissue, herbivore elicitation changes concentrations and biosynthetic kinetics of individual compounds. Using stably transformed N. attenuata plants silenced in jasmonate production and perception, or production of N. attenuata Hyp-rich glycopeptide systemin precursor by RNA interference, we identified malonylation as the key biosynthetic step regulated by herbivory and jasmonate signaling. We stably silenced N. attenuata geranylgeranyl diphosphate synthase (ggpps) to reduce precursors for the HGL-DTG skeleton, resulting in reduced total HGL-DTGs and greater vulnerability to native herbivores in the field. Larvae of the specialist tobacco hornworm (Manduca sexta) grew up to 10 times as large on ggpps silenced plants, and silenced plants suffered significantly more damage from herbivores in N. attenuata's native habitat than did wild-type plants. We propose that high concentrations of HGL-DTGs effectively defend valuable tissues against herbivores and that malonylation may play an important role in regulating the distribution and storage of HGL-DTGs in plants. PMID:20081114

  16. Evolutionary potential and adaptation of Banksia attenuata (Proteaceae) to climate and fire regime in southwestern Australia, a global biodiversity hotspot (United States)

    He, Tianhua; D’Agui, Haylee; Lim, Sim Lin; Enright, Neal J.; Luo, Yiqi


    Substantial climate changes are evident across Australia, with declining rainfall and rising temperature in conjunction with frequent fires. Considerable species loss and range contractions have been predicted; however, our understanding of how genetic variation may promote adaptation in response to climate change remains uncertain. Here we characterized candidate genes associated with rainfall gradients, temperatures, and fire intervals through environmental association analysis. We found that overall population adaptive genetic variation was significantly affected by shortened fire intervals, whereas declining rainfall and rising temperature did not have a detectable influence. Candidate SNPs associated with rainfall and high temperature were diverse, whereas SNPs associated with specific fire intervals were mainly fixed in one allele. Gene annotation further revealed four genes with functions in stress tolerance, the regulation of stomatal opening and closure, energy use, and morphogenesis with adaptation to climate and fire intervals. B. attenuata may tolerate further changes in rainfall and temperature through evolutionary adaptations based on their adaptive genetic variation. However, the capacity to survive future climate change may be compromised by changes in the fire regime.

  17. Mechanisms of Optimal Defense Patterns in Nicotiana attenuata: Flowering Attenuates Herbivory-elicited Ethylene and Jasmonate Signaling

    Institute of Scientific and Technical Information of China (English)

    Celia Diezel; Silke AIImann; lan T. Baldwin


    To defend themselves against herbivore attack,plants produce secondary metabolites,which are variously inducible and constitutively deployed,presumably to optimize their fitness benefits in light of their fitness costs.Three phytohormones,jasmonates (JA) and their active forms,the JA-isoleucine (JA-Ile) and ethylene (ET),are known to play central roles in the elicitation of induced defenses,but little is known about how this mediation changes over ontogeny.The Optimal Defense Theory (ODT) predicts changes in the costs and benefits of the different types of defenses and has been usefully extrapolated to their modes of deployment.Here we studied whether the herbivore-induced accumulation of JA,JA-lle and ET changed over ontogeny in Nicotiana attenuata,a native tobacco in which inducible defenses are particularly well studied.Herbivore-elicited ET production changed dramatically during six developmental stages,from rosette through flowering,decreasing with the elongation of the first corollas during flower development.This decrease was largely recovered within a day after flower removal by decapitation.A similar pattern was found for the herbivore-induced accumulation of JA and JA-IIe.These results are consistent with ODT predictions and suggest that the last steps in floral development control the inducibility of at least three plant hormones,optimizing defense-growth tradeoffs.

  18. Tissue specific diurnal rhythms of metabolites and their regulation during herbivore attack in a native tobacco, Nicotiana attenuata.

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    Sang-Gyu Kim

    Full Text Available Ecological performance is all about timing and the endogenous clock that allows the entrainment of rhythms and anticipation of fitness-determining events is being rapidly characterized. How plants anticipate daily abiotic stresses, such as cold in early mornings and drought at noon, as well as biotic stresses, such as the timing of pathogen infections, is being explored, but little is known about the clock's role in regulating responses to insect herbivores and mutualists, whose behaviors are known to be strongly diurnally regulated and whose attack is known to reconfigure plant metabolomes. We developed a liquid chromatography-mass spectrometry procedure and analyzed its output with model-based peak picking algorithms to identify metabolites with diurnal accumulation patterns in sink/source leaves and roots in an unbiased manner. The response of metabolites with strong diurnal patterns to simulated attack from the specialist herbivore, Manduca sexta larvae was analyzed and annotated with in-house and public databases. Roots and leaves had largely different rhythms and only 10 ions of 182 oscillating ions in leaves and 179 oscillating ions in roots were rhythmic in both tissues: root metabolites mainly peaked at dusk or night, while leaf metabolites peaked during the day. Many oscillating metabolites showed tissue-specific regulation by simulated herbivory of which systemic responses in unattacked tissues were particularly pronounced. Diurnal and herbivory-elicited accumulation patterns of disaccharide, phenylalanine, tyrosine, lyciumoside I, coumaroyl tyramine, 12-oxophytodienoic acid and jasmonic acid and those of their related biosynthetic transcripts were examined in detail. We conclude that oscillating metabolites of N. attenuata accumulate in a highly tissue-specific manner and the patterns reveal pronounced diurnal rhythms in the generalized and specialized metabolism that mediates the plant's responses to herbivores and mutualists. We

  19. Digestive duet: midgut digestive proteinases of Manduca sexta ingesting Nicotiana attenuata with manipulated trypsin proteinase inhibitor expression.

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    Jorge A Zavala

    Full Text Available BACKGROUND: The defensive effect of endogenous trypsin proteinase inhibitors (NaTPIs on the herbivore Manduca sexta was demonstrated by genetically altering NaTPI production in M. sexta's host plant, Nicotiana attenuata. To understand how this defense works, we studied the effects of NaTPI on M. sexta gut proteinase activity levels in different larval instars of caterpillars feeding freely on untransformed and transformed plants. METHODOLOGY/ PRINCIPAL FINDINGS: Second and third instars larvae that fed on NaTPI-producing (WT genotypes were lighter and had less gut proteinase activity compared to those that fed on genotypes with either little or no NaTPI activity. Unexpectedly, NaTPI activity in vitro assays not only inhibited the trypsin sensitive fraction of gut proteinase activity but also halved the NaTPI-insensitive fraction in third-instar larvae. Unable to degrade NaTPI, larvae apparently lacked the means to adapt to NaTPI in their diet. However, caterpillars recovered at least part of their gut proteinase activity when they were transferred from NaTPI-producing host plants to NaTPI-free host plants. In addition extracts of basal leaves inhibited more gut proteinase activity than did extracts of middle stem leaves with the same protein content. CONCLUSIONS/ SIGNIFICANCE: Although larvae can minimize the effects of high NaTPI levels by feeding on leaves with high protein and low NaTPI activity, the host plant's endogenous NaTPIs remain an effective defense against M. sexta, inhibiting gut proteinase and affecting larval performance.

  20. Virus-Induced Gene Silencing Using Tobacco Rattle Virus as a Tool to Study the Interaction between Nicotiana attenuata and Rhizophagus irregularis.

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    Karin Groten

    Full Text Available Most land plants live in a symbiotic association with arbuscular mycorrhizal fungi (AMF that belong to the phylum Glomeromycota. Although a number of plant genes involved in the plant-AMF interactions have been identified by analyzing mutants, the ability to rapidly manipulate gene expression to study the potential functions of new candidate genes remains unrealized. We analyzed changes in gene expression of wild tobacco roots (Nicotiana attenuata after infection with mycorrhizal fungi (Rhizophagus irregularis by serial analysis of gene expression (SuperSAGE combined with next generation sequencing, and established a virus-induced gene-silencing protocol to study the function of candidate genes in the interaction. From 92,434 SuperSAGE Tag sequences, 32,808 (35% matched with our in-house Nicotiana attenuata transcriptome database and 3,698 (4% matched to Rhizophagus genes. In total, 11,194 Tags showed a significant change in expression (p2-fold change after infection. When comparing the functions of highly up-regulated annotated Tags in this study with those of two previous large-scale gene expression studies, 18 gene functions were found to be up-regulated in all three studies mainly playing roles related to phytohormone metabolism, catabolism and defense. To validate the function of identified candidate genes, we used the technique of virus-induced gene silencing (VIGS to silence the expression of three putative N. attenuata genes: germin-like protein, indole-3-acetic acid-amido synthetase GH3.9 and, as a proof-of-principle, calcium and calmodulin-dependent protein kinase (CCaMK. The silencing of the three plant genes in roots was successful, but only CCaMK silencing had a significant effect on the interaction with R. irregularis. Interestingly, when a highly activated inoculum was used for plant inoculation, the effect of CCaMK silencing on fungal colonization was masked, probably due to trans-complementation. This study demonstrates that

  1. Virus-Induced Gene Silencing Using Tobacco Rattle Virus as a Tool to Study the Interaction between Nicotiana attenuata and Rhizophagus irregularis. (United States)

    Groten, Karin; Pahari, Nabin T; Xu, Shuqing; Miloradovic van Doorn, Maja; Baldwin, Ian T


    Most land plants live in a symbiotic association with arbuscular mycorrhizal fungi (AMF) that belong to the phylum Glomeromycota. Although a number of plant genes involved in the plant-AMF interactions have been identified by analyzing mutants, the ability to rapidly manipulate gene expression to study the potential functions of new candidate genes remains unrealized. We analyzed changes in gene expression of wild tobacco roots (Nicotiana attenuata) after infection with mycorrhizal fungi (Rhizophagus irregularis) by serial analysis of gene expression (SuperSAGE) combined with next generation sequencing, and established a virus-induced gene-silencing protocol to study the function of candidate genes in the interaction. From 92,434 SuperSAGE Tag sequences, 32,808 (35%) matched with our in-house Nicotiana attenuata transcriptome database and 3,698 (4%) matched to Rhizophagus genes. In total, 11,194 Tags showed a significant change in expression (p2-fold change) after infection. When comparing the functions of highly up-regulated annotated Tags in this study with those of two previous large-scale gene expression studies, 18 gene functions were found to be up-regulated in all three studies mainly playing roles related to phytohormone metabolism, catabolism and defense. To validate the function of identified candidate genes, we used the technique of virus-induced gene silencing (VIGS) to silence the expression of three putative N. attenuata genes: germin-like protein, indole-3-acetic acid-amido synthetase GH3.9 and, as a proof-of-principle, calcium and calmodulin-dependent protein kinase (CCaMK). The silencing of the three plant genes in roots was successful, but only CCaMK silencing had a significant effect on the interaction with R. irregularis. Interestingly, when a highly activated inoculum was used for plant inoculation, the effect of CCaMK silencing on fungal colonization was masked, probably due to trans-complementation. This study demonstrates that large

  2. Getting to know you: Identification of pygmy killer whales (Feresa attenuata and melon-headed whales (Peponocephala electra under challenging conditions

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    Salvatore Siciliano


    Full Text Available Abstract Melon-headed whale (Peponocephala electra and Pygmy killer whale (Feresa attenuata are very poorly known species and are often confused with each other. We examined in detail Figure 3 in MARIGO and GIFFONI (2010 who reported that two melon-headed whales were taken in a surface driftnet about 90 nm off Santos, Brazil. We concluded they were in fact pygmy killer whales and explain our reasoning. To aid in future identifications, we illustrate and describe some of the main differences between these two species of small cetaceans. The incident reported by MARIGO and GIFFONI (2010 might represent the 'tip of the iceberg' regarding the incidental catches of cetaceans by pelagic drift nets off Brazil. Offshore driftnetting operating along the south-southeastern coast of Brazil may threaten pygmy killer whales.

  3. The Sesquiterpenes(E-ß-Farnesene and (E-α-Bergamotene Quench Ozone but Fail to Protect the Wild Tobacco Nicotiana attenuata from Ozone, UVB, and Drought Stresses.

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    Evan C Palmer-Young

    Full Text Available Among the terpenes, isoprene (C5 and monoterpene hydrocarbons (C10 have been shown to ameliorate abiotic stress in a number of plant species via two proposed mechanisms: membrane stabilization and direct antioxidant effects. Sesquiterpene hydrocarbons (C15 not only share the structural properties thought to lend protective qualities to isoprene and monoterpene hydrocarbons, but also react rapidly with ozone, suggesting that sesquiterpenes may similarly enhance tolerance of abiotic stresses. To test whether sesquiterpenes protect plants against ozone, UVB light, or drought, we used transgenic lines of the wild tobacco Nicotiana attenuata. The transgenic plants expressed a maize terpene synthase gene (ZmTPS10 which produced a blend of (E-ß-farnesene and (E-α-bergamotene, or a point mutant of the same gene (ZmTPS10M which produced (E-ß-farnesene alone,. (E-ß-farnesene exerted a local, external, and transient ozone-quenching effect in ozone-fumigated chambers, but we found no evidence that enhanced sesquiterpene production by the plant inhibited oxidative damage, or maintained photosynthetic function or plant fitness under acute or chronic stress. Although the sesquiterpenes (E-ß-farnesene and (E-α-bergamotene might confer benefits under intermittent heat stress, which was not tested, any roles in relieving abiotic stress may be secondary to their previously demonstrated functions in biotic interactions.

  4. 狐尾龙舌兰的组织培养和快速繁殖%Tissue Culture and Rapid Propagation of Agave attenuata

    Institute of Scientific and Technical Information of China (English)

    李勇; 杨建芬; 张朝成


    @@ 1 植物名称狐尾龙舌兰(Agave attenuata). 2 材料类别幼芽、幼叶片. #3 培养条件诱导芽分化和继代培养基:(1)MS+6-BA 0.5 mg*L-1(单位下同)+NAA 0.05, (2)MS+6-BA 2+NAA 0.05, (3)MS+6-BA 2+KT 2+ZT 0.5+CH 250;诱导生根培养基:(4)1/2MS+IBA 2,(5)1/2MS+IBA 2+NAA 0.75+CH 250.每种培养基均附加3%蔗糖和0.65%琼脂,pH 5.8.培养温度为(25±1)℃,每天光照16 h,光照度2 000 lx左右.

  5. Chloroplast DNA transgresses species boundaries and evolves at variable rates in the California closed-cone pines (Pinus radiata, P. muricata, and P. attenuata). (United States)

    Hong, Y P; Krupkin, A B; Strauss, S H


    We studied phylogenetic relationships among populations and species in the California closed-cone pines (Pinus radiata D. Don, P. attenuata Lemm., and P. muricata D. Don) via chloroplast DNA restriction site analysis. Data on genetic polymorphism within and among 19 populations in the three species were collected using 9 to 20 restriction enzymes and 38 to 384 trees. Because only five clades and extremely low intraclade diversity were found, additional phylogenetic data were collected using a single representative per clade and two outgroup species, P. oocarpa Schiede and P. jeffreyi Loud. In total, 25 restriction enzymes were employed and approximately 2.7 kb surveyed (2.3% of genome). The five clades recognized were Monterey pine, knobcone pine, and the southern, intermediate, and northern races of bishop pine. On the basis of bootstrapping, both Wagner and Dollo parsimony analyses strongly separated the northern and intermediate races of bishop pine from the southern race; knobcone pine from Monterey and bishop pines; and the closed-cone pines from the two outgroups. Approximate divergence times were estimated for the lineages leading to knobcone pine and to the intermediate and northern populations of bishop pine. The position of Monterey pine relative to bishop pine within their monophyletic clade was unresolved. Surprisingly, Montery pine and the southern race of bishop pine were much more similar to one another than was the southern race of bishop pine to its conspecific intermediate and northern races. Both the Monterey and southern bishop pine lineages also evolved severalfold more slowly than did the knobcone pine and intermediate-northern bishop pine lineages.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. [Distribution and environmental conditions related to the behavior in the bottlenose dolphin (Tursiops truncatus) and the spotted dolphin (Stenella attenuata) (Cetacea: Delphinidae) in Golfo Dulce, Costa Rica]. (United States)

    Cubero-Pardo, Priscilla


    Habitat characteristics influencing behavior in animal species vary locally. The influence that a particular environmental characteristic can have on a species depends not only on other variables, but on morphological, physiological and social conditions of that species. In this study, developed from June 1996 to July 1997, I studied whether specific behaviors are related to particular distribution areas and environmental factors in the bottlenose (Tursiops truncatus) and the spotted dolphin (Stenella attenuata). The study area was covered along oblicuous linear transects, and the behavior of single groups was observed from 15 min to 5 h. Environmental factors such as depth, temperature, salinity and distance from shore, among others, were considered. For the bottlenose dolphin, foraging/feeding activities showed exclusive coincidence with river mouths, coral reef and mangrove areas, while social and milling activities where seen close to feeding areas. Traveling occurred along different points parallel to the coast, with a low percentage of cases across the gulf (16.56 %), suggesting that the bottlenose rarely crosses from one side to the other. In the spotted dolphin, several behaviors were observed simultaneously in the schools and it was not possible to associate areas with particular behaviors. The lack of significant relationships among activities and particular environmental variables (ANOVA tests) is attributed to three aspects: (a) transitions among activities generally occurred into a low variable area, (b) dolphins often traveled along large areas without changing activities and (c) environmental conditions in Golfo Dulce are homogeneous. In the two species the highest average in the number of individuals per group corresponded to the category of active socializing, followed by traveling, passive socializing and feeding. In the case of the bottlenose dolphin, the smallest group size was associated with feeding activities (ANOVA, F= 2.624, p=0.037, n=156

  7. Herbivore defense responses and associated herbivore defense mechanism as revealed by comparing a resistant wild soybean with a susceptible cultivar

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    Xiaoyi Wang


    Full Text Available Plants have evolved sophisticated defense mechanisms against herbivores to help them adapt to the environment. Understanding the defense mechanisms in plants can help us control insects in a more effective manner. In this study, we found that compared with Tianlong 2 (a cultivated soybean with insect susceptibility, ED059 (a wild soybean line with insect resistance contains sharper pubescence tips, as well as lower transcript levels of wound-induced protein kinase (WIPK and salicylic acid-induced protein kinase (SIPK, which are important mitogen-activated protein kinases involved in early defense response to herbivores. The observed lower transcript levels of WIPK and SIPK induced higher levels of jasmonic acid (JA, JA biosynthesis enzymes (AOC3 and some secondary metabolites in ED059. Functional analysis of the KTI1 gene via Agrobacterium-mediated transformation in Arabidopsis thaliana indicated that it plays an important role in herbivore defense in ED059. We further investigated the molecular response of third-instar Helicoverpa armigera (Hübner larvae to Tianlong 2 and ED059. We found apoptotic cells only in the midguts of larvae that fed on ED059. Compared with larvae reared on the susceptible cultivar Tianlong 2, transcript levels of catalase (CAT and glutathione S-transferase (GST were up-regulated, whereas those of CAR, CHSB, and TRY were down-regulated in larvae that fed on the highly resistant variety ED059. We propose that these differences underlie the different herbivore defense responses of ED059 and Tianlong 2.

  8. Silencing Brassinosteroid Receptor BRI1 Impairs Herbivory-elicited Accumulation of Jasmonic Acid-isoleucine and Diterpene Glycosides, but not Jasmonic Acid and Trypsin Proteinase Inhibitors in Nicotiana attenuata

    Institute of Scientific and Technical Information of China (English)

    Da-Hai Yang; lan T.Baldwin; Jianqiang Wu


    The brassinosteroid (BR) receptor,BR insensitive 1 (BRI1),plays a critical role in plant development,but whether BRI1-mediated BR signaling is involved in plant defense responses to herbivores was largely unknown.Here,we examined the function of BRI1 in the resistance of Nicotiana attenuata (Solanaceae) to its specialist insect herbivore Manduca sexta.Jasmonic acid (JA) and JA-isoleucine conjugate (JA-Ile) are important hormones that mediate resistance to herbivores and we found that after wounding or simulated herbivory NaBRI1 had little effect on JA levels,but was important for the induction of JA-Ile.Further experiments revealed that decreased JAR (the enzyme for JA-Ile production) activity and availability of lie in NaBRI1-silenced plants were likely responsible for the low JA-Ile levels.Consistently,M.sexta larvae gained more weight on NaBRI1-silenced plants than on the control plants.Quantification of insect feeding-induced secondary metabolites revealed that silencing NaBRI1 resulted in decreased levels of carbon-rich defensive secondary metabolites (hydroxygeranyllinalool diterpene glycosides,chlorogenic acid,and rutin),but had little effect on the nitrogen-rich ones (nicotine and trypsin proteinase inhibitors).Thus,NaBRI1-mediated BR signaling is likely involved in plant defense responses to M.sexta,including maintaining JA-Ile levels and the accumulation of several carbon-rich defensive secondary metabolites.

  9. Using Genome-Wide SNPs to Detect Structure in High-Diversity and Low-Divergence Populations of Severely Impacted Eastern Tropical Pacific Spinner (Stenella longirostris And Pantropical Spotted Dolphins (S. attenuata

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    Matthew Steven Leslie


    Full Text Available Millions of spinner (Stenella longirostris and pantropical spotted dolphins (Stenella attenuata died since the 1960’s as bycatch in tuna nets in the eastern tropical Pacific Ocean. Despite three decades of protection, they show little-to-no sign of recovery (although recent fisheries-independent abundance estimates are not available. In efforts to establish biologically meaningful management boundaries for recovery, endemic subspecies and multiple stocks have been proposed. However, genetic differentiation among most of these units has been difficult to identify, possibly due to low statistical power stemming from large historical abundances, ongoing gene flow, and recent divergence. We tested for genetic structure at multiple hierarchical levels by analyzing the largest dataset to date brought to bear on these questions. Single nucleotide polymorphisms (SNPs were collected from nuclear DNA regions associated with the restriction enzyme site PstI from 72 spinner dolphins and 58 pantropical spotted dolphins using genotype-by-sequencing (GBS. Our results support the current subspecies for both species and indicate stock-level separation for Tres Marias spinner dolphins and the two offshore pantropical spotted dolphin stocks in this area. Although bycatch has been reduced a small fraction of pre-protection levels, incidental mortality continues to impact these populations. Our results are important for the ongoing management and recovery of these highly-impacted pelagic dolphins in the eastern tropical Pacific Ocean.

  10. A mitogen-activated protein kinase NtMPK4 activated by SIPKK is required for jasmonic acid signaling and involved in ozone tolerance via stomatal movement in tobacco. (United States)

    Gomi, Kenji; Ogawa, Daisuke; Katou, Shinpei; Kamada, Hiroshi; Nakajima, Nobuyoshi; Saji, Hikaru; Soyano, Takashi; Sasabe, Michiko; Machida, Yasunori; Mitsuhara, Ichiro; Ohashi, Yuko; Seo, Shigemi


    The mitogen-activated protein kinase (MAPK) cascade is involved in responses to biotic and abiotic stress in plants. In this study, we isolated a new MAPK, NtMPK4, which is a tobacco homolog of Arabidopsis MPK4 (AtMPK4). NtMPK4 was activated by wounding along with two other wound-responsive tobacco MAPKs, WIPK and SIPK. We found that NtMPK4 was activated by salicylic acid-induced protein kinase kinase (SIPKK), which has been isolated as an SIPK-interacting MAPK kinase. In NtMPK4 activity-suppressed tobacco, wound-induced expression of jasmonic acid (JA)-responsive genes was inhibited. NtMPK4-silenced plants showed enhanced sensitivity to ozone. Inversely, transgenic tobacco plants, in which SIPKK or the constitutively active type SIPKK(EE) was overexpressed, exhibited greater responsiveness to wounding with enhanced resistance to ozone. We further found that NtMPK4 was expressed preferentially in epidermis, and the enhanced sensitivity to ozone in NtMPK4-silenced plants was caused by an abnormal regulation of stomatal closure in an ABA-independent manner. These results suggest that NtMPK4 is involved in JA signaling and in stomatal movement.

  11. Toxicity of Polychlorinated Diphenyl Ethers in Hydra Attenuata and in Rat Whole Embryo Culture (United States)


    were fed freshly hatched Artemia naupii ( brine shrimp ) once a day. The shrimp eggs (approximately 15 ml) were hydrated in 1% NaCl for approximately 2...all other chemicals were from Sigma (St. Louis, MO.). Brine shrimp eggs were purchased from Carolina Biological Supply, Burlington, NC. The original...days at room temperature. Eggs were aerated throughout the hatching period. Prior to feeding to the hydra, brine shrimp were siphoned into a fish net

  12. Narboh D, a Respiratory Burst Oxidase Homolog in Nicotiana attenuata, is Required for Late Defense Responses After Herbivore Attack

    Institute of Scientific and Technical Information of China (English)

    Jinsong Wu; Lei Wang; Hendrik Wünsche; Ian T.Baldwin


    The superoxide (O2-)-generating NADPH oxidases are crucial for the defense of plants against attack from pathogens; however,it remains unknown whether they also mediate responses against chewing insect herbivores.The transcripts of the respiratory burst NADPH oxidase homolog Narboh D in Nicotiana attenuate are rapidly and transiently elicited by wounding,and are amplified when Manduca sexta oral secretions (OS) are added to the wounds.The fatty-acid-amino-acid-conjugates (FACs),demonstrably the major elicitors in M.sexta OS,are responsible for the increase in Narboh D transcripts.Silencing Narboh D significantly reduced reactive oxygen species (ROS) levels after OS elicitation,but neither OS-elicited jasmonic acid (JA) or JA-isoleucine (JA-Ile) bursts,pivotal hormones that regulates plant resistance to herbivores,nor early transcripts of herbivore defense-related genes (NaJAR4 and NaPAL1),were influenced.However,late OS-elicited increases in trypsin proteinase inhibitors (TPIs),as well as the transcript levels of defense genes such as polyphenol oxidase,TPI and Thionin were significantly reduced.In addition,Narboh D-silenced plants were more vulnerable to insect herbivores,especially the larvae of the generalist Spodoptera littoralis.We thus conclude that Narboh D-based defenses play an important role in late herbivore-elicited responses.

  13. Investigation of trophic level and niche partitioning of 7 cetacean species by stable isotopes, and cadmium and arsenic tissue concentrations in the western Pacific Ocean. (United States)

    Liu, J-Y; Chou, L-S; Chen, M-H


    A total of 24 stranded or bycatch cetaceans, including Balaenoptera omurai, Lagenodelphis hosei, Kogia sima, Stenella attenuata, Grampus griseus, Neophocaena phocaenoides, and Sousa chinensis, were collected from 2001 to 2011 in Taiwan. Using the muscular δ(13)C and δ(15)N data, three ecological groups were identified as the oceanic baleen whale, the neritic, and the coastal toothed whale groups, coinciding with their taxonomy, feeding habits and geographical distribution. A horizontal inshore to offshore distribution was found for the sympatric neritic toothed dolphins, G. griseus, K. sima, S. attenuata, and L. hosei in the outermost offshore waters, accompanying their growth. For the first time we identify Taiwan's Chinese white dolphin, S. chinensis, as an exclusive fish eater. Cd and As bioaccumulated in the G. griseus, L. hosei and S. attenuata increase as they grow. Prey-derived As- and Cd-induced health threats were found in L. hosei, and G. griseus.

  14. The genus Asterina (Asterinaceae on the members of Myristicaceae in Kerala State, India

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    V.B. Hosagoudar


    Full Text Available This paper gives an account of three Asterina species infecting members of the family Myristicaceae, namely, Asterina knemae attenuatae infected the leaves of Knema attenuata, Asterina myristicae infecting the leaves of Myristica sp. and Asterina myristicacearum infecting the leaves of Myristica malabarica. Of these, Asterina myristicae and Asterina myristicacearum are found to be new species. All these three species are described and illustrated in detail and a key is provided to them. Key to all the species of the genus Asterina reported on Myristicaceae is also supplanted to this study.

  15. No junctional communication between epithelial cells in hydra

    DEFF Research Database (Denmark)

    de Laat, S W; Tertoolen, L G; Grimmelikhuijzen, C J


    properties of the junctional membranes by electrophysiological methods and by intracellular-dye iontophoresis. We report here that no electrotonic coupling is detectable between epithelial cells of Hydra attenuata in: (1) intact animals, (2) head-regenerating animals, (3) cell re-aggregates, and (4) hydra...

  16. New xenophytes from Gran Canaria (Canary Islands, Spain), with emphasis on naturalized and (potentially) invasive species


    Verloove, F


    Trabajos recientes de campo en Gran Canaria han facilitado el descubrimiento de nuevas localidades para plantas vasculares no nativas. Agave attenuata, Antigonon leptopus, Atriplex nummularia, Cascabela thevetia, Cenchrus echinatus, Cuscuta campestris, Diplachne fusca subsp. uninervia, Diplotaxis tenuifolia, Dysphania anthelmintica (hasta ahora confundida con D. ambrosioides), Eclipta prostrata, Euphorbia pulcherrima, Fagopyrum esculentum, Gossypium barbadense, Lablab purpureus, Lemna minuta,...

  17. 77 FR 56613 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the... (United States)


    ... the pantropical spotted (Stenella attenuata), spinner (S. longirostris) dolphins, and the short-finned... or equivalent), when required. Laser range-finding binoculars (Leica LRF 1200 laser rangefinder or... spotted, and striped dolphins are estimated to be the most common species in the area) with...

  18. A new species of Medinilla (Melastomataceae) from Sumatra and notes on allied species

    NARCIS (Netherlands)

    Nayar, M.P.


    Frutex. Ramis junioribus subangulatis, puberubs, vetustioribus teretibus glabratis. Folia opposita, elliptico-lanceolata, 6—10 cm longa, 1.5—2.8 cm lata, basi cuneata, apice longe acuminato-attenuata, margine integra, supra glabra, subtus minute puberula, 3-nervia, venulis transversis indistinctis,

  19. Bombesin-like immunoreactivity in the nervous system of hydra

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J; Dockray, G J; Yanaihara, N


    With immunocytochemical methods, nerve cells have been detected in Hydra attenuata containing bombesin-like immunoreactivity. These nerve cells are located in ectoderm of all body regions of the animal and are especially abundant in basal disk and tentacles. Radioimmunoassay of extracts of hydra ...

  20. A new Maculotriton

    NARCIS (Netherlands)

    Bayer, Ch.


    Drupa (Maculotriton) buitendijki n. sp. (Pl. I, fig. 1). Testa parvula, tenuis, elongato-turrita, nitidula. Anfractus 10, apice laevi anfractibus 3l/2 annumerata, liris subtilimis, longitudinalibus et transversis ad decussationem nodulosis reticulata Varices 10. Apertura ovata, utrinque attenuata, l

  1. Ectoparasites from the South American sea lion (Otaria flavescens from Peruvian coast

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    Luis A. Gomez-Puerta


    Full Text Available Two species of ectoparasites were collected from a South American sea lion (Otaria flavescens found stranded on the beaches of Chorrillos in Lima, Peru. The ectoparasites were identified as Antarctophthirus microchir (Phthiraptera and Orthohalarachne attenuata (Acari. Some morphological characteristics are described in this report. The finding of these ectoparasites is the first records in Peru.

  2. Antarctic sponges (Porifera, Demospongiae of the South Shetland Islands and vicinity: part I. Spirophorida, Astrophorida, Hadromerida, Halichondrida and Haplosclerida Esponjas Antárticas (Porifera, Demospongiae das Ilhas Shetland do Sul e áreas próximas: parte I. Spirophorida, Astrophorida, Hadromerida, Halichondrida e Haplosclerida

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    Maurício Campos


    Full Text Available The aim of this work is to redescribe 11 species of sponges collected through the Brazilian Antarctic Program (PROANTAR, at the South Shetland Islands and vicinity. New information is provided on the Antarctic sponge fauna, in regard to species richness and the geographical and bathymetric distributions of identified species. The following species were identified and are here illustrated and fully described: Cinachyra antarctica (Carter, 1872, Cinachyra barbata Sollas, 1886, Craniella leptoderma (Sollas, 1886, Tethyopsis longispinum (Lendenfeld, 1907, Polymastia invaginata Kirkpatrick, 1907, Homaxinella balfourensis (Ridley & Dendy, 1886, Suberites montiniger Carter, 1880, Halichondria (Eumastia attenuata (Topsent, 1915, Haliclona (Soestella chilensis (Thiele, 1905, Hemigellius bidens (Topsent, 1901 and Calyx arcuarius (Topsent, 1913. Two new records are given for the Antarctic continent: Halichondria (Eumastia attenuata (Topsent, 1915 and Haliclona (Soestella chilensis (Thiele, 1905. Tethyopsis longispinum (Lendenfeld, 1907, Suberites montiniger Carter, 1880 and Hemigellius bidens (Topsent, 1901 represent the first records for this sector of the continent. Bathymetric data are extended for T. longispinum and H. attenuata.O objetivo deste trabalho é redescrever 11 espécies de esponjas coletadas através do Programa Antártico Brasileiro (PROANTAR, nas Is. Shetland do Sul e áreas próximas. Nnovas informações são fornecidas acerca do conhecimento da fauna de poríferos da Antártica, tanto para a riqueza específica como para os dados referentes às distribuições geográfica e batimétrica das espécies identificadas. As seguintes espécies foram identificadas e são aqui ilustradas e amplamente descritas: Cinachyra antarctica (Carter, 1872, Cinachyra barbata Sollas, 1886, Craniella leptoderma (Sollas, 1886, Tethyopsis longispinum (Lendenfeld, 1907, Polymastia invaginata Kirkpatrick, 1907, Homaxinella balfourensis (Ridley & Dendy, 1886

  3. Mitochondrial DNA Sequence Variation in North Atlantic Long-Finned Pilot Whales, Globicephala melas (United States)


    australis) ( Schaeff et al. 1991), and spinner and spotted dolphins {Stenella longirostris and S. attenuata) (Dizon et al. 1991). Restriction enzyme...geographic scale, minke whale populations can be viewed as genetically distinct stocks. Schaeff et al. (1991) surveyed whole mtDNA from 10 northern and...San Diego. Ryder, O.A (1986). Species conservation and systematics: the dilemma of subspecies. Trends Ecol Evol 1: 9-10. Schaeff , C, Kraus, S

  4. Native bacterial endophytes promote host growth in a species-specific manner; phytohormone manipulations do not result in common growth responses.

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    Hoang Hoa Long

    Full Text Available BACKGROUND: All plants in nature harbor a diverse community of endophytic bacteria which can positively affect host plant growth. Changes in plant growth frequently reflect alterations in phytohormone homoeostasis by plant-growth-promoting (PGP rhizobacteria which can decrease ethylene (ET levels enzymatically by 1-aminocyclopropane-1-carboxylate (ACC deaminase or produce indole acetic acid (IAA. Whether these common PGP mechanisms work similarly for different plant species has not been rigorously tested. METHODOLOGY/PRINCIPAL FINDINGS: We isolated bacterial endophytes from field-grown Solanum nigrum; characterized PGP traits (ACC deaminase activity, IAA production, phosphate solubilization and seedling colonization; and determined their effects on their host, S. nigrum, as well as on another Solanaceous native plant, Nicotiana attenuata. In S. nigrum, a majority of isolates that promoted root growth were associated with ACC deaminase activity and IAA production. However, in N. attenuata, IAA but not ACC deaminase activity was associated with root growth. Inoculating N. attenuata and S. nigrum with known PGP bacteria from a culture collection (DSMZ reinforced the conclusion that the PGP effects are not highly conserved. CONCLUSIONS/SIGNIFICANCE: We conclude that natural endophytic bacteria with PGP traits do not have general and predictable effects on the growth and fitness of all host plants, although the underlying mechanisms are conserved.

  5. Comparative observations on female stridulatory spines of the genera Ducetia and Kuwayamaea ( Orthoptera : Phaneropteridae)%条螽属和桑螽属雌性发声刺的比较观察

    Institute of Scientific and Technical Information of China (English)

    石福明; 蒋书楠


    报道了对尖翅条螽 Ducetia attenuata Xia et Liu、日本条螽 D.japonica (Thunberg)、施氏条螽 D.strelkovi Gorochov etstorzhenko 和中华桑螽 Kuwayamaea chinensis(Brunner)、长翅桑螽 K.longipenn shi et Zhe、札幌桑螽 K.sapporensis Mats.etshir 的雌性发声刺的观察结果.这6个种的雌性发声刺在数量与形态上具较明显的差异.

  6. Chlorophyll fluorescence in vivo as a probe for rapid measurement of tolerance to ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Smillie, R.M. (Macquarie Univ., North Ryde (Australia). School of Biological Sciences)


    Chlorophyll fluorescence in vivo was progressively lost in pea leaves irradiated with either short or long-wave light. The changes were consistent with the development in the intact leaves of an inhibitory site on the photooxidizing side of photosystem II. In contrast, leaves of two species of Agave, plants regarded as more resistant to UV radiation, showed only minor changes in chlorophyll fluorescence. Agave americana was affected less than A. attenuata. The application of measurements of chlorophyll fluorescence in vivo to screening for tolerance to UV radiation is discussed.

  7. Ectoparasites from the South American sea lion (Otaria flavescens) from Peruvian coast


    Gomez-Puerta, Luis A.; Omar Gonzales-Viera


    Dos especies de ectoparásitos fueron colectados de un lobo marino sudamericano (Otaria flavescens) hallado varado en las playas de Chorrillos, en Lima, Perú. Los ectoparásitos fueron identificados como Antarctophthirus microchir (Phthiraptera) y Orthohalarachne attenuata (Acari). Algunas características morfológicas son descritas en el presente reporte. El hallazgo de estos ectoparásitos constituyen los primeros registros en el Perú. Two species of ectoparasites were collected from a South...

  8. Instabilities in the Gamma Ray Burst central engine. What makes the jet variable? (United States)

    Janiuk, Agnieszka; Yuan, Ye-Fei; Perna, Rosalba; Di Matteo, Tiziana


    Both types of long and short gamma ray bursts involve a stage of a hyper-Eddington accretion of hot and dense plasma torus onto a newly born black hole. The prompt gamma ray emission originates in jets at some distance from this `central engine' and in most events is rapidly variable, having a form of sipkes and subpulses. This indicates at the variable nature of the engine itself, for which a plausible mechanism is an internal instability in the accreting flow. We solve numerically the structure and evolution of the neutrino-cooled torus. We take into account the detailed treatment of the microphysics in the nuclear equation of state that includes the neutrino trapping effect. The models are calculated for both Schwarzschild and Kerr black holes. We find that for sufficiently large accretion rates (>~10Msolar s-1 for non-rotating black hole, and >~1Msolar s-1 for rotating black hole, depending on its spin), the inner regions of the disk become opaque, while the helium nuclei are being photodissociated. The sudden change of pressure in this region leads to the development of a viscous and thermal instability, and the neutrino pressure acts similarly to the radiation pressure in sub-Eddington disks. In the case of rapidly rotating black holes, the instability is enhanced and appears for much lower accretion rates. We also find the important and possibly further destabilizing role of the energy transfer from the rotating black hole to the torus via the magnetic coupling.

  9. Taxonomic uncertainty and the loss of biodiversity on Christmas Island, Indian Ocean. (United States)

    Eldridge, Mark D B; Meek, Paul D; Johnson, Rebecca N


    The taxonomic uniqueness of island populations is often uncertain which hinders effective prioritization for conservation. The Christmas Island shrew (Crocidura attenuata trichura) is the only member of the highly speciose eutherian family Soricidae recorded from Australia. It is currently classified as a subspecies of the Asian gray or long-tailed shrew (C. attenuata), although it was originally described as a subspecies of the southeast Asian white-toothed shrew (C. fuliginosa). The Christmas Island shrew is currently listed as endangered and has not been recorded in the wild since 1984-1985, when 2 specimens were collected after an 80-year absence. We aimed to obtain DNA sequence data for cytochrome b (cytb) from Christmas Island shrew museum specimens to determine their taxonomic affinities and to confirm the identity of the 1980s specimens. The Cytb sequences from 5, 1898 specimens and a 1985 specimen were identical. In addition, the Christmas Island shrew cytb sequence was divergent at the species level from all available Crocidura cytb sequences. Rather than a population of a widespread species, current evidence suggests the Christmas Island shrew is a critically endangered endemic species, C. trichura, and a high priority for conservation. As the decisions typically required to save declining species can be delayed or deferred if the taxonomic status of the population in question is uncertain, it is hoped that the history of the Christmas Island shrew will encourage the clarification of taxonomy to be seen as an important first step in initiating informed and effective conservation action.

  10. Parasites of cetaceans stranded on the Pacific coast of Costa Rica. (United States)

    Oliveira, J B; Morales, J A; González-Barrientos, R C; Hernández-Gamboa, J; Hernández-Mora, G


    Information regarding parasitic fauna of cetaceans from Costa Rica is provided for the first time. A total of 25 stranded dolphins and whales were examined between 2001 and 2009, including striped dolphin (Stenella coeruleoalba) (n=19), pantropical spotted dolphin (S. attenuata) (n=2), spinner dolphin (S. longirostris) (n=1), bottlenose dolphin (Tursiops truncatus) (n=1), dwarf sperm whale (Kogia sima) (n=1) and Cuvier's beaked whale (Ziphius cavirostris) (n=1). Pathological findings associated with the parasites are also presented. In the most representative dolphin species, S. coeruleoalba, the prevalence of parasites was 89.5%; moreover, all examined specimens of S. attenuata, S. longirostris, T. truncatus and Z. cavirostris presented parasites. No parasites were recovered from K. sima. Fourteen helminth taxa were identified, including six species of cestodes (Strobilocephalus triangularis, Tetrabothrius forsteri, Trigonocotyle sp., Phyllobothrium delphini, Monorygma grimaldi, Tetraphyllidea gen. sp. plerocercoid), four digeneans (Nasitrema globicephalae, Brachycladium palliatum, B. pacificum and Oschmarinella albamarina) and four nematodes (Anisakis spp., Halocercus lagenorhynchi, Halocercus sp. and Crassicauda anthonyi). A commensal crustacean, Xenobalanus globicipitis, was also identified. All identified parasites representing new geographic records for the Pacific coast of Central America and new host records are presented. Parasitological information is valuable for conservation of cetaceans in Pacific coast of Costa Rica.

  11. Shifting Nicotiana attenuata’s diurnal rhythm does not alter its resistance to the specialist herbivore Manduca sexta

    Institute of Scientific and Technical Information of China (English)

    Jasmin Herden; Stefan Meldau; Sang-Gyu Kim; Grit Kunert; Youngsung Joo; Ian T Baldwin; Meredith C Schuman


    Arabidopsis thaliana plants are less resistant to attack by the generalist lepidopteran herbivore Trichoplusia ni when plants and herbivores are entrained to opposite, versus identical diurnal cycles and tested under constant conditions. This effect is associated with circadian fluctuations in levels of jasmonic acid, the transcription factor MYC2, and glucosino-late contents in leaves. We tested whether a similar effect could be observed in a different plant–herbivore system:the wild tobacco Nicotiana attenuata and its co-evolved specialist herbivore, Manduca sexta. We measured larval growth on plants under both constant and diurnal conditions following identical or opposite entrainment, profiled the metabolome of attacked leaf tissue, quantified specific metabolites known to reduce M. sexta growth, and monitored M. sexta feeding activity under all experimental conditions. Entrainment did not consistently affect M. sexta growth or plant defense induction. However, both were reduced under constant dark conditions, as was M. sexta feeding activity. Our data indicate that the response induced by M. sexta in N. attenuata is robust to diurnal cues and independent of plant or herbivore entrain-ment. We propose that while the patterns of constitutive or general damage-induced defense may undergo circadian fluctuation, the orchestration of specific induced responses is more complex.

  12. Native root-associated bacteria rescue a plant from a sudden-wilt disease that emerged during continuous cropping. (United States)

    Santhanam, Rakesh; Luu, Van Thi; Weinhold, Arne; Goldberg, Jay; Oh, Youngjoo; Baldwin, Ian T


    Plants maintain microbial associations whose functions remain largely unknown. For the past 15 y, we have planted the annual postfire tobacco Nicotiana attenuata into an experimental field plot in the plant's native habitat, and for the last 8 y the number of plants dying from a sudden wilt disease has increased, leading to crop failure. Inadvertently we had recapitulated the common agricultural dilemma of pathogen buildup associated with continuous cropping for this native plant. Plants suffered sudden tissue collapse and black roots, symptoms similar to a Fusarium-Alternaria disease complex, recently characterized in a nearby native population and developed into an in vitro pathosystem for N. attenuata. With this in vitro disease system, different protection strategies (fungicide and inoculations with native root-associated bacterial and fungal isolates), together with a biochar soil amendment, were tested further in the field. A field trial with more than 900 plants in two field plots revealed that inoculation with a mixture of native bacterial isolates significantly reduced disease incidence and mortality in the infected field plot without influencing growth, herbivore resistance, or 32 defense and signaling metabolites known to mediate resistance against native herbivores. Tests in a subsequent year revealed that a core consortium of five bacteria was essential for disease reduction. This consortium, but not individual members of the root-associated bacteria community which this plant normally recruits during germination from native seed banks, provides enduring resistance against fungal diseases, demonstrating that native plants develop opportunistic mutualisms with prokaryotes that solve context-dependent ecological problems.

  13. Bones and genes: resolution problems in three Vietnamese species of Crocidura (Mammalia, Soricomorpha, Soricidae and the description of an additional new species

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    Paula Jenkins


    Full Text Available Recent investigations of Southeast Asian white toothed shrews belonging to the genus Crocidura have revealed discrepancies between the results of morphological and molecular studies. The following study concerns three species of Crocidura occurring in Vietnam, namely C. attenuata, C. tanakae and C. wuchihensis, and an undescribed fourth species revealed by molecular analysis. For many years Crocidura attenuata has been known to occur in Vietnam but, until very recently, the morphologically similar and comparably sized C. tanakae was believed to be restricted to Taiwan. Following several molecular studies over the last few years, this species is now believed to be considerably more widespread and recognised as occuring also in Vietnam. The results of one of these recent molecular studies also revealed the presence of an undescribed species of Crocidura, similar in size and morphology to Crocidura wuchihensis, which is herein described. Data are provided on geographical variation in Vietnam and the problems of defining morphologically similar yet molecularly disparate species are discussed.

  14. Algal endosymbiosis in brown hydra: host/symbiont specificity. (United States)

    Rahat, M; Reich, V


    Host/symbiont specificity has been investigated in non-symbiotic and aposymbiotic brown and green hydra infected with various free-living and symbiotic species and strains of Chlorella and Chlorococcum. Morphology and ultrastructure of the symbioses obtained have been compared. Aposymbiotic Swiss Hydra viridis and Japanese H. magnipapillata served as controls. In two strains of H. attenuata stable hereditary symbioses were obtained with Chlorococcum isolated from H. magnipapillata. In one strain of H. vulgaris, in H. oligactis and in aposymbiotic H. viridis chlorococci persisted for more than a week. Eight species of free-living Chlorococcum, 10 symbiotic and 10 free-living strains of Chlorella disappeared from the brown hydra within 1-2 days. In H. magnipapillata there was a graded distribution of chlorococci along the polyps. In hypostomal cells there were greater than 30 algae/cell while in endodermal cells of the mid-section or peduncle less than 10 algae/cell were found. In H. attenuata the algal distribution was irregular, there were up to five chlorocci/cell, and up to 20 cells/hydra hosted algae. In the dark most cells of Chlorococcum disappeared from H. magnipapillata and aposymbiotic hydra were obtained. Chlorococcum is thus an obligate phototroph, and host-dependent heterotrophy is not required for the preservation of a symbiosis. The few chlorococci that survived in the dark seem to belong to a less-demanding physiological strain. In variance with known Chlorella/H. viridis endosymbioses the chlorococci in H. magnipapillata and H. attenuata were tightly enveloped in the vacuolar membrane of the hosting cells with no visible perialgal space. Chlorococcum reproduced in these vacuoles and up to eight daughter cells were found within the same vacuole. We suggest that the graded or scant distribution of chlorococci in the various brown hydra, their inability to live in H. viridis and the inability of the various chlorellae to live in brown hydra are the

  15. Arabidopsis Lectin Receptor Kinases LecRK-IX.1 and LecRK-IX.2 Are Functional Analogs in Regulating Phytophthora Resistance and Plant Cell Death. (United States)

    Wang, Yan; Cordewener, Jan H G; America, Antoine H P; Shan, Weixing; Bouwmeester, Klaas; Govers, Francine


    L-type lectin receptor kinases (LecRK) are potential immune receptors. Here, we characterized two closely-related Arabidopsis LecRK, LecRK-IX.1 and LecRK-IX.2, of which T-DNA insertion mutants showed compromised resistance to Phytophthora brassicae and Phytophthora capsici, with double mutants showing additive susceptibility. Overexpression of LecRK-IX.1 or LecRK-IX.2 in Arabidopsis and transient expression in Nicotiana benthamiana increased Phytophthora resistance but also induced cell death. Phytophthora resistance required both the lectin domain and kinase activity, but for cell death, the lectin domain was not needed. Silencing of the two closely related mitogen-activated protein kinase genes NbSIPK and NbNTF4 in N. benthamiana completely abolished LecRK-IX.1-induced cell death but not Phytophthora resistance. Liquid chromatography-mass spectrometry analysis of protein complexes coimmunoprecipitated in planta with LecRK-IX.1 or LecRK-IX.2 as bait, resulted in the identification of the N. benthamiana ABC transporter NbPDR1 as a potential interactor of both LecRK. The closest homolog of NbPDR1 in Arabidopsis is ABCG40, and coimmunoprecipitation experiments showed that ABCG40 associates with LecRK-IX.1 and LecRK-IX.2 in planta. Similar to the LecRK mutants, ABCG40 mutants showed compromised Phytophthora resistance. This study shows that LecRK-IX.1 and LecRK-IX.2 are Phytophthora resistance components that function independent of each other and independent of the cell-death phenotype. They both interact with the same ABC transporter, suggesting that they exploit similar signal transduction pathways.

  16. Cetacean diversity on the Parnaiba Delta, Maranhão state, northeastern Brazil. (United States)

    Magalhães, F A; Tosi, C H; Garri, R G; Chellappa, S; Silva, F L


    The increase in the research of cetacean surveys on the Brazilian coast has brought new data on the distribution of species never reported before. The present work reviews the current knowledge on cetaceans species and extends this knowledge with an analysis of cetaceans stranded in the Parnaiba Delta, on the coast of Maranhão State, Brazil. The studies on cetacean diversity on the coast of the Parnaíba Delta were made from August 2004 to August 2006. Fourteen strandings were reported, representing six distinct species, such as the estuarine dolphin (Sotalia guianensis), humpback whale (Megaptera novaeangliae), Bryde's whales (Balaenoptera edeni), dwarf minke whale (Balaenoptera acutorostrata), pigmy killer whale (Feresa attenuata), sperm whale (Physeter macrocephalus) and two specimens which have not yet been identified. The significant degree of cetacean diversity in the region shows that the Parnaíba Delta is, possibly, of an important area for cetacean studies in Brasil.

  17. Cetacean diversity on the Parnaiba Delta, Maranhão state, northeastern Brazil

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    FA. Magalhães

    Full Text Available The increase in the research of cetacean surveys on the Brazilian coast has brought new data on the distribution of species never reported before. The present work reviews the current knowledge on cetaceans species and extends this knowledge with an analysis of cetaceans stranded in the Parnaiba Delta, on the coast of Maranhão State, Brazil. The studies on cetacean diversity on the coast of the Parnaíba Delta were made from August 2004 to August 2006. Fourteen strandings were reported, representing six distinct species, such as the estuarine dolphin (Sotalia guianensis, humpback whale (Megaptera novaeangliae, Bryde's whales (Balaenoptera edeni, dwarf minke whale (Balaenoptera acutorostrata, pigmy killer whale (Feresa attenuata, sperm whale (Physeter macrocephalus and two specimens which have not yet been identified. The significant degree of cetacean diversity in the region shows that the Parnaíba Delta is, possibly, of an important area for cetacean studies in Brasil.

  18. White-toothed shrews (Mammalia, Soricomorpha, Crocidura of coastal islands of Vietnam

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    Alexei Abramov


    Full Text Available New findings of the white-toothed shrews (Crocidura spp. from offshore islands of Vietnam are reported. The species identifications have been confirmed by the analysis of complete mitochondrial cytochrome b gene (1140 bp. Crocidura phuquocensis is the only species found in the Phu Quoc Island. Crocidura fuliginosa has been recorded from two islands of the Con Dao Archipelago (Con Son and Bai Canh. The occurrence of C. fuliginosa in Vietnam has been genetically confirmed for the first time. Crocidura attenuata has been collected from the Cat Ba Island for the first time, and this finding corresponds well with the proposal that the species’ distribution is confined to the north and east of the Red River only.

  19. Assessing the potential toxicity of resuspended sediment

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, C.; Babut, M.; Ferard, J.F.; Martel, L.; Garric, J.


    Two moderately contaminated freshwater sediments (Sorel Harbour, St. Lawrence River, Canada) were subjected to a suspension event. The objective was to assess the environmental impact of the disposal of dredged material in water, in particular, the short-term effects of dumping on the water column and the long-term effects of dredged sediment deposits. In a series of microcosms, the sediments were left to stand for 25 d under flow-through conditions. In a second series of microcosms, sediments were vigorously suspended for 15 min before being left to settle and were submitted to the same treatment as reference sediments during the following 25 d. Physicochemical and biological parameters (Daphnia magna and Hydra attenuata survival) were measured in overlying water throughout the experiment. Sediment toxicity was assessed with Chironomus tentans and Hyalella azteca exposed to sediments collected at both the beginning and end of the 25-d period. Pore-water toxicity was evaluated with D. magna. During the suspension process, in the Sorel Harbour mixed sediment overlying water, the authors observed effects on H. attenuata survival and ammonia and metals (chromium, copper, and zinc) releases. Meanwhile, in reference (nonmixed) and mixed sediments as well as in associated pore waters, there were no significant chemical modifications no biological effects after the 25-d experiments. The developed approach, which attempts to simulate a dumping process, aims at allowing the assessment of the short- and long-term hazards resulting from a resuspension process in overlying water and in resettled sediments using both chemical and biological measurements.

  20. Overview of results from the WaterTox intercalibration and environmental testing phase II program: part 2, ecotoxicological evaluation of drinking water supplies. (United States)

    Diaz-Baez, M C; Sánchez, W A; Dutka, B J; Ronco, A; Castillo, G; Pica-Granados, Y; Castillo, L E; Ridal, J; Arkhipchuk, V; Srivastava, R C


    Because of rapid population growth, industrial development, and intensified agricultural production increasing amounts of chemicals are being released into the environment, polluting receiving water bodies around the world. Given the potential health risk associated with the presence of toxicants in water sources used for drinking yet the scarcity of available data, there is a need to evaluate these waters and develop strategies to reduce and prevent their contamination. The present study examined the applicability of a battery of simple, inexpensive bioassays in environmental management and the relevance of the test results in establishing the toxicological quality of water sources and drinking water within the framework of the eight-country WaterTox Network, sponsored by the International Development Research Centre, Ottawa, Canada. Seventy-six samples were collected from surface and groundwater sources and seven samples from drinking water treatment plants. Each sample was tested with a core battery of bioassays (Daphnia magna, Hydra attenuata, and Lactuca sativa root inhibition tests) and a limited set of physical and chemical parameters. In addition, three labs included the Selenastrum capricornutum test. When no toxic effects were found with the battery, samples were concentrated 10x using a solid-phase extraction (SPE) procedure. Nonconcentrated natural water samples produced a toxic response in 24% of cases with all three core bioassays. When all bioassays are considered, the percentage of raw samples showing toxicity with at least one bioassay increased to 60%. Of seven treated drinkingwater samples, four showed toxicity with at least one bioassay, raising the possibility that treatment processes in these instances were unable to remove toxic contaminants. The Daphnia magna and Hydra attenuata tests indicated a high level of sensitivity overall. Although only three of the eight countries used S. capricornutum, it proved to be an efficient and reliable

  1. New xenophytes from Gran Canaria (Canary Islands, Spain, with emphasis on naturalized and (potentially invasive species

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    Verloove, F.


    Full Text Available Trabajos recientes de campo en Gran Canaria han facilitado el descubrimiento de nuevas localidades para plantas vasculares no nativas. Agave attenuata, Antigonon leptopus, Atriplex nummularia, Cascabela thevetia, Cenchrus echinatus, Cuscuta campestris, Diplachne fusca subsp. uninervia, Diplotaxis tenuifolia, Dysphania anthelmintica (hasta ahora confundida con D. ambrosioides, Eclipta prostrata, Euphorbia pulcherrima, Fagopyrum esculentum, Gossypium barbadense, Lablab purpureus, Lemna minuta, Opuntia leucotricha, Passiflora edulis, Pennisetum glaucum, Phaseolus acutifolius, Pluchea carolinensis, Prosopis juliflora, Salvia microphylla, Schinus terebinthifolius, Senna spectabilis, Solanum chrysotrichum, Tecoma stans, Tipuana tipu, Urochloa mutica, U. plantaginea y Washingtonia se citan por primera vez para las Islas Canarias, mientras que Alopecurus myosuroides, Amaranthus blitoides, Bothriochloa ischaemum var. songarica, Cardamine flexuosa subsp. debilis, Heliotropium curassavicum, Leonotis nepetifolia, Medicago lupulina, Parkinsonia aculeata, Physalis peruviana, Phytolacca americana y Turnera ulmifolia son nuevas para la flora de la isla de Gran Canaria. Finalmente, se confirma la presencia de Paspalum vaginatum, P. distichum y Cortaderia selloana en Gran Canaria.Trabajos recientes de campo en Gran Canaria han facilitado el descubrimiento de nuevas localidades para plantas vasculares no nativas. Agave attenuata, Antigonon leptopus, Atriplex nummularia, Cascabela thevetia, Cenchrus echinatus, Cuscuta campestris, Diplachne fusca subsp. uninervia, Diplotaxis tenuifolia, Dysphania anthelmintica (hasta ahora confundida con D. ambrosioides, Eclipta prostrata, Euphorbia pulcherrima, Fagopyrum esculentum, Gossypium barbadense, Lablab purpureus, Lemna minuta, Opuntia leucotricha, Passiflora edulis, Pennisetum glaucum, Phaseolus acutifolius, Pluchea carolinensis, Prosopis juliflora, Salvia microphylla, Schinus terebinthifolius, Senna spectabilis, Solanum

  2. Spectrum of clinically relevant Exophiala species in the United States. (United States)

    Zeng, J S; Sutton, D A; Fothergill, A W; Rinaldi, M G; Harrak, M J; de Hoog, G S


    Numerous members of the genus Exophiala are potential agents of human and animal mycoses. The majority of these infections are cutaneous and superficial, but also fatal systemic infections are known. We re-identified 188 clinical isolates from the United States, which had a preliminary morphological identification of Exophiala species, by sequencing internal transcribed spacer (ITS) region of the rRNA. Molecular identifications of the strains were as follows, in order of frequency: 55 E. dermatitidis (29.3%), 37 E. xenobiotica (19.7%), 35 E. oligosperma (18.6%), 13 E. lecanii-corni (6.9%), 12 E. phaeomuriformis (6.4%), 7 E. jeanselmei (3.7%), 7 E. bergeri (3.7%), 6 E. mesophila (3.2%), 5 E. spinifera (2.7%), 3 Exophiala sp. 1 (1.6%), 3 E. attenuata (1.6%), 3 Phialophora europaea (1.3%), 1 E. heteromorpha (0.5%), and 1 Exophiala sp. 2 (0.5%) strains. Exophiala strains were repeatedly isolated from deep infections (39.9%) involving lung, pleural fluid, sputum, digestive organs (stomach, intestines, bile), heart, brain, spleen, bone marrow, blood, dialysis fluid, lymph node, joint, breast, middle ear, throat, and intraocular tissues. About 38.3% of the Exophiala spp. strains were agents of cutaneous infections including skin, mucous membranes, nail, and corneal epithelium lesions. The other strains caused superficial infections (0.5%, including hair) or subcutaneous infection (12.0%, including paranasal sinusitis, mycetoma, and subcutaneous cyst). The systemic infections were preponderantly caused by E. dermatitidis, E. oligosperma, E. phaeomuriformis, E. xenobiotica, and E. lecanii-corni. Strains of E. bergeri, E. spinifera, E. jeanselmei, E. mesophila, and E. attenuata mainly induced cutaneous and subcutaneous infections. Since relatively few unknown ITS motifs were encountered, we suppose that the list of opportunistic Exophiala species in temperate climates is nearing completion, but a number of species still have to be described.

  3. A rapid and sensitive method for the simultaneous analysis of aliphatic and polar molecules containing free carboxyl groups in plant extracts by LC-MS/MS

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    Bonaventure Gustavo


    Full Text Available Abstract Background Aliphatic molecules containing free carboxyl groups are important intermediates in many metabolic and signalling reactions, however, they accumulate to low levels in tissues and are not efficiently ionized by electrospray ionization (ESI compared to more polar substances. Quantification of aliphatic molecules becomes therefore difficult when small amounts of tissue are available for analysis. Traditional methods for analysis of these molecules require purification or enrichment steps, which are onerous when multiple samples need to be analyzed. In contrast to aliphatic molecules, more polar substances containing free carboxyl groups such as some phytohormones are efficiently ionized by ESI and suitable for analysis by LC-MS/MS. Thus, the development of a method with which aliphatic and polar molecules -which their unmodified forms differ dramatically in their efficiencies of ionization by ESI- can be simultaneously detected with similar sensitivities would substantially simplify the analysis of complex biological matrices. Results A simple, rapid, specific and sensitive method for the simultaneous detection and quantification of free aliphatic molecules (e.g., free fatty acids (FFA and small polar molecules (e.g., jasmonic acid (JA, salicylic acid (SA containing free carboxyl groups by direct derivatization of leaf extracts with Picolinyl reagent followed by LC-MS/MS analysis is presented. The presence of the N atom in the esterified pyridine moiety allowed the efficient ionization of 25 compounds tested irrespective of their chemical structure. The method was validated by comparing the results obtained after analysis of Nicotiana attenuata leaf material with previously described analytical methods. Conclusion The method presented was used to detect 16 compounds in leaf extracts of N. attenuata plants. Importantly, the method can be adapted based on the specific analytes of interest with the only consideration that the

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

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


    Many angiosperm plants, including basal dicots, eudicots, and monocots, emit (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene, which is derived from geranyllinalool, in response to biotic challenge. An Arabidopsis (Arabidopsis thaliana) geranyllinalool synthase (GLS) belonging to the e/f clade of the terpene synthase (TPS) family and two Fabaceae GLSs that belong to the TPS-g clade have been reported, making it unclear which is the main route to geranyllinalool in plants. We characterized a tomato (Solanum lycopersicum) TPS-e/f gene, TPS46, encoding GLS (SlGLS) and its homolog (NaGLS) from Nicotiana attenuata. The Km value of SlGLS for geranylgeranyl diphosphate was 18.7 µm, with a turnover rate value of 6.85 s–1. In leaves and flowers of N. attenuata, which constitutively synthesize 17-hydroxygeranyllinalool glycosides, NaGLS is expressed constitutively, but the gene can be induced in leaves with methyl jasmonate. In tomato, SlGLS is not expressed in any tissue under normal growth but is induced in leaves by alamethicin and methyl jasmonate treatments. SlGLS, NaGLS, AtGLSs, and several other GLSs characterized only in vitro come from four different eudicot families and constitute a separate branch of the TPS-e/f clade that diverged from kaurene synthases, also in the TPS-e/f clade, before the gymnosperm-angiosperm split. The early divergence of this branch and the GLS activity of genes in this branch in diverse eudicot families suggest that GLS activity encoded by these genes predates the angiosperm-gymnosperm split. However, although a TPS sequence belonging to this GLS lineage was recently reported from a basal dicot, no representative sequences have yet been found in monocot or nonangiospermous plants. PMID:25052853

  5. Los mamíferos marinos en la costa central de Oaxaca Marine mammals along the central coast of Oaxaca

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    Juan Meraz


    Full Text Available Con la finalidad de conocer las especies de mamíferos marinos que se encuentran en la costa central de Oaxaca, se elaboró un listado comentando las características de los registros obtenidos. Se incluyeron las observaciones hechas a lo largo de 30 recorridos por mar, entre junio de 1999 y enero de 2004, realizadas entre las bahías de Huatulco y la playa de La Escobilla. Adicionalmente se incluyeron registros de animales varados, así como observaciones realizadas desde la costa. Se presentan comentarios sobre el registro de 8 especies en la zona, incluyendo las localidades y fechas de los avistamientos. Stenella attenuata es la especie más abundante, y la zona de Zipolite-Isla Roca Blanca la localidad con el mayor número de avistamientos. Dado el crecimiento turístico del lugar, es importante contar con este tipo de registros ya que es poco lo que se sabe sobre estas especies en esta porción de la costa oaxaqueña.With the aim of documenting the species of marine mammals that occur along the central coast of Oaxaca, a list with the characteristics of the records was elaborated based on observations made throughout 30 surveys from Huatulco Bays to La Escobilla beach between June 1999 and January 2004. Additional records from stranded animals are included, as well observations from the coast. Comments on 8 species are presented, including localities and dates of sightings. Stenella attenuata is the most abundant species. Zipolite-Roca Blanca island was the locality with the highest number of sightings. This records are important to promote conservation due growth of tourism in the area, given that Oaxaca coast is poorly known regarding marine mammals.

  6. Macroalgas submareales de la bahía de Todos Santos, Baja California, México Submareal macroalgae of the Todos Santos Bay, Baja California, Mexico

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    Raúl Aguilar-Rosas


    Full Text Available Con el fin de identificar y caracterizar la composición de especies de la zona submareal de la bahía de Todos Santos, Baja California, México; se realizaron muestreos de macroalgas marinas bentónicas en 7 sitios durante 1995-2000. Como resultado de 25 buceos Scuba entre 3 y 33 m de profundidad se encontraron 150 especies de macroalgas para el área de estudio; 10 son Chlorophyta, 26 Phaeophyta y 114 Rhodophyta. Del total, 47 son registros nuevos para el área de estudio y 2 de éstos, Faucheocolax attenuata Setchell y Minium parvum R.L. Moe, son nuevos para la flora marina del Pacífico de México. Se incluye una revisión de las investigaciones en las que se han considerado las macroalgas presentes en la bahía de Todos Santos y una discusión sobre la composición de las especies encontradas, su distribución vertical y reproducción, así como sobre las especies epífitas y parásitas del área.In order to identify and characterize the species composition of the subtidal zone of the Todos Santos Bay, Baja California, Mexico, benthic marine macroalgae were sampled at 7 sites from 1995 to 2000. As a result of 25 scuba at derds for the study area, of which Faucheocolax attenuata Setchell and R.L Moe Minium parvum are new to the marine flora of Pacific Mexico. We include a research that consider the macroalpths between 3 and 33 m we found a total of 150 species of macroalgae for the study area, of which 10 are Chlorophyta, 26 Phaeophyta and 114 Rhodophyta; 47 species represent new recogae in the Todos Santos Bay and a discussion on the composition of species found, its vertical distribution and reproduction, particularly the species epiphytes and parasites present in the study area.

  7. Chemical and ecotoxicological assessments of water samples before and after being processed by a Water Treatment Plant

    Directory of Open Access Journals (Sweden)

    Regina Teresa Rosim Monteiro


    Full Text Available Physicochemical and ecotoxicological measurements were employed to appraise the water quality of the Corumbataí River raw water (RW intake, and that of its filtered (FW and treated (TW waters, processed by the Water Treatment Plant (WTP of Piracicaba (SP, Brazil during 2010. Some herbicides: ametrine, atrazine, simazine and tebuthiuron, were measured, with levels ranging from 0.01 to 10.3 µg L-1 . These were lower than those required to produce ecotoxicological effects to aquatic life based on published literature. Similarly, trihalomethanes, such as chloroform and bromodichloromethane produced as a result of the WTP process were also shown to be present in concentrations that would neither harm environmental nor human health. Elevated free chlorine concentrations found in FW and TW were credibly responsible for toxicity effects observed in algae and daphnids. (Pseudokirchneriella subcapitata and Daphnia magna. In contrast, results of toxicity testing conducted with Hydra attenuata suggested that this organism is resistant to free chorine and could be used for drinking water evaluations. Coupling bioassays with chemical analyses proved valuable to uncover putative cause-effect relationships existing between physical, chemical and toxic results, as well as in optimizing data interpretation of water quality.

  8. Nicotine's defensive function in nature.

    Directory of Open Access Journals (Sweden)

    Anke Steppuhn


    Full Text Available Plants produce metabolites that directly decrease herbivore performance, and as a consequence, herbivores are selected for resistance to these metabolites. To determine whether these metabolites actually function as defenses requires measuring the performance of plants that are altered only in the production of a certain metabolite. To date, the defensive value of most plant resistance traits has not been demonstrated in nature. We transformed native tobacco(Nicotiana attenuata with a consensus fragment of its two putrescine N-methyl transferase (pmt genes in either antisense or inverted-repeat (IRpmt orientations. Only the latter reduced (by greater than 95% constitutive and inducible nicotine. With D(4-nicotinic acid (NA, we demonstrate that silencing pmt inhibits nicotine production, while the excess NA dimerizes to form anatabine. Larvae of the nicotine-adapted herbivore Manduca sexta (tobacco hornworm grew faster and, like the beetle Diabrotica undecimpunctata, preferred IRpmt plants in choice tests. When planted in their native habitat, IRpmt plants were attacked more frequently and, compared to wild-type plants, lost 3-fold more leaf area from a variety of native herbivores, of which the beet armyworm, Spodoptera exigua, and Trimerotropis spp. grasshoppers caused the most damage. These results provide strong evidence that nicotine functions as an efficient defense in nature and highlights the value of transgenic techniques for ecological research.

  9. Catechol, a major component of smoke, influences primary root growth and root hair elongation through reactive oxygen species-mediated redox signaling. (United States)

    Wang, Ming; Schoettner, Matthias; Xu, Shuqing; Paetz, Christian; Wilde, Julia; Baldwin, Ian T; Groten, Karin


    Nicotiana attenuata germinates from long-lived seedbanks in native soils after fires. Although smoke signals have been known to break seed dormancy, whether they also affect seedling establishment and root development remains unclear. In order to test this, seedlings were treated with smoke solutions. Seedlings responded in a dose-dependent manner with significantly increased primary root lengths, due mainly to longitudinal cell elongation, increased numbers of lateral roots and impaired root hair development. Bioassay-driven fractionations and NMR were used to identify catechol as the main active compound for the smoke-induced root phenotype. The transcriptome analysis revealed that mainly genes related to auxin biosynthesis and redox homeostasis were altered after catechol treatment. However, histochemical analyses of reactive oxygen species (ROS) and the inability of auxin applications to rescue the phenotype clearly indicated that highly localized changes in the root's redox-status, rather than in levels of auxin, are the primary effector. Moreover, H2 O2 application rescued the phenotype in a dose-dependent manner. Chemical cues in smoke not only initiate seed germination, but also influence seedling root growth; understanding how these cues work provides new insights into the molecular mechanisms by which plants adapt to post-fire environments.

  10. Joint estimation of contemporary seed and pollen dispersal rates among plant populations. (United States)

    Robledo-Arnuncio, J J


    There are few statistical methods for estimating contemporary dispersal among plant populations. A maximum-likelihood procedure is introduced here that uses pre- and post-dispersal population samples of biparentally inherited genetic markers to jointly estimate contemporary seed and pollen immigration rates from a set of discrete external sources into a target population. Monte Carlo simulations indicate that accurate estimates and reliable confidence intervals can be obtained using this method for both pollen and seed migration rates at modest sample sizes (100 parents/population and 100 offspring) when population differentiation is moderate (F(ST) ≥ 0.1), or by increasing pre-dispersal samples (to about 500 parents/population) when genetic divergence is weak (F(ST) = 0.01). The method exhibited low sensitivity to the number of source populations and achieved good accuracy at affordable genetic resolution (10 loci with 10 equifrequent alleles each). Unsampled source populations introduced positive biases in migration rate estimates from sampled sources, although they were minor when the proportion of immigration from the latter was comparatively low. A practical application of the method to a metapopulation of the Australian resprouter shrub Banksia attenuata revealed comparable levels of directional seed and pollen migration among dune groups, and the estimate of seed dispersal was higher than a previous estimate based on conservative assignment tests. The method should be of interest to researchers and managers assessing broad-scale nonequilibrium seed and pollen gene flow dynamics in plants.

  11. Honing in on phenotypes: comprehensive two-dimensional gas chromatography of herbivory-induced volatile emissions and novel opportunities for system-level analyses. (United States)

    Gaquerel, Emmanuel; Baldwin, Ian T


    Plant volatile organic compound (VOC) production requires a complex network of biochemical pathways, which, although well mapped from a biochemical point of view, remains only partly understood with regard to its physiological and genetic regulation. Additionally, although analytical procedures for plant VOC measurement have become increasingly faster and more sensitive in recent years, pinpointing relevant shifts in VOC production from the thousands of molecular fragments that are generated by modern mass spectrometer instruments remains challenging. Here we discuss novel opportunities for system-wide analysis provided by the implementation of non-targeted data processing and multivariate statistics in VOC analysis. We illustrate the value of implementing non-targeted data processing with examples of recent findings from our group on the interactive control exerted by salivary components of a lepidopteran herbivore, Manduca sexta, on herbivory-induced VOC emissions in the wild tobacco Nicotiana attenuata. Finally, we briefly discuss the use of multi-platform data integration for probing the nature of metabolic and regulatory systems underlying VOC emissions.

  12. Degradation of textile dyes by cyanobacteria

    Directory of Open Access Journals (Sweden)

    Priscila Maria Dellamatrice

    Full Text Available Abstract Dyes are recalcitrant compounds that resist conventional biological treatments. The degradation of three textile dyes (Indigo, RBBR and Sulphur Black, and the dye-containing liquid effluent and solid waste from the Municipal Treatment Station, Americana, São Paulo, Brazil, by the cyanobacteria Anabaena flos-aquae UTCC64, Phormidium autumnale UTEX1580 and Synechococcus sp. PCC7942 was evaluated. The dye degradation efficiency of the cyanobacteria was compared with anaerobic and anaerobic-aerobic systems in terms of discolouration and toxicity evaluations. The discoloration was evaluated by absorption spectroscopy. Toxicity was measured using the organisms Hydra attenuata, the alga Selenastrum capricornutum and lettuce seeds. The three cyanobacteria showed the potential to remediate textile effluent by removing the colour and reducing the toxicity. However, the growth of cyanobacteria on sludge was slow and discoloration was not efficient. The cyanobacteria P. autumnale UTEX1580 was the only strain that completely degraded the indigo dye. An evaluation of the mutagenicity potential was performed by use of the micronucleus assay using Allium sp. No mutagenicity was observed after the treatment. Two metabolites were produced during the degradation, anthranilic acid and isatin, but toxicity did not increase after the treatment. The cyanobacteria showed the ability to degrade the dyes present in a textile effluent; therefore, they can be used in a tertiary treatment of effluents with recalcitrant compounds.

  13. Herbivore perception decreases photosynthetic carbon-assimilation and reduces stomatal conductance by engaging 12-oxo-phytodienoic acid, mitogen-activated protein kinase 4 and cytokinin perception. (United States)

    Meza-Canales, Ivan D; Meldau, Stefan; Zavala, Jorge A; Baldwin, Ian T


    Herbivory-induced changes in photosynthesis have been documented in many plant species, however the complexity of photosynthetic regulation and analysis has thwarted progress in understanding the mechanism involved, particularly those elicited by herbivore-specific elicitors. Here we analyzed the early photosynthetic gas-exchange responses in Nicotiana attenuata plants after wounding and elicitation with Manduca sexta oral-secretions, and the pathways regulating these responses. Elicitation with M. sexta oral-secretions rapidly decreased photosynthetic carbon-assimilation (AC ) in treated and systemic (untreated, vascularly connected) leaves, which were associated with changes in stomatal conductance, rather than with changes in Rubisco activity and RuBP-turnover. Phytohormone profiling and gas-exchange-analysis of oral-secretion-elicited transgenic plants altered in phytohormone regulation, biosynthesis and perception, combined with micrografting techniques, revealed that the local photosynthetic-responses were mediated by 12-oxo-phytodienoic acid (OPDA), while the systemic responses involved interactions among jasmonates, cytokinins and abscisic acid signaling mediated by mitogen activated protein kinase 4 (MPK4). The analysis also revealed a role for cytokinins interacting with MPK4 in CO2 -mediated stomatal regulation. Hence oral-secretions, while eliciting jasmonic acid-mediated defense responses, also elicits OPDA-mediated changes in stomatal conductance and AC , an observation illustrating the complexity and economy of the signaling that regulates defense and carbon assimilation pathways in response to herbivore attack.

  14. Annotated checklist and fisheries interactions of cetaceans in Togo, with evidence of Antarctic minke whale in the Gulf of Guinea. (United States)

    Segniagbeto, Gabriel H; VAN Waerebeek, Koen; Bowessidjaou, Joseph E; Ketoh, Koffivi; Kpatcha, Takouda K; Okoumassou, Kotchikpa; Ahoedo, Kossi


    Based on strandings and captures, 9 cetacean species, including 6 odontocetes and 3 mysticetes, are documented (photos and specimens) in Togo's coastal waters (newly-recorded species marked with an asterisk): Antarctic minke whale (Balaenoptera bonaerensis*), Bryde's whale (Balaenoptera brydei or B. edeni), humpback whale (Megaptera novaeangliae), sperm whale (Physeter macrocephalus), pygmy sperm whale (Kogia breviceps*), short-finned pilot whale (Globicephala macrorhynchus*), pantropical spotted dolphin (Stenella attenuata*), common bottlenose dolphin (Tursiops truncatus) and common dolphin Delphinus sp. An anecdotal sighting record for killer whale (Orcinus orca) is considered reliable. The lack of Sousa teuszii records in Togo is consistent with its apparent contemporaneous absence in Ghana. The B. bonaerensis specimen, entangled in a purse seine set on small pelagics, is a first record for the Gulf of Guinea. The occurrence of this Southern Ocean species north of the equator underscores the severe gaps in our understanding of cetacean distribution off western Africa. The majority of artisanal fishermen operating in Togolese coastal waters are of Ghanaian origin and are thought to promote trade and consumption of cetacean bushmeat. Because captures are illegal, enforced with some success in the main fishing centers, covert landings of cetaceans are exceedingly difficult to monitor, quantify or sample. Concern is expressed about pollution of Togo's coastal waters with heavy metals due to phosphorite mining and export from the coastal basin near Hahotoé and Kpogamé.

  15. Selection of a bioassay battery to assess toxicity in the affluents and effluents of three water-treatment plants

    Directory of Open Access Journals (Sweden)

    Paola Bohórquez-Echeverry


    Full Text Available The assessment of water quality includes the analysis of both physical-chemical and microbiological parameters. However,none of these evaluates the biological effect that can be generated in ecosystems or humans. In order to define the most suitable organismsto evaluate the toxicity in the affluent and effluent of three drinking-water treatment plants, five acute toxicity bioassays were used,incorporating three taxonomic groups of the food chain. Materials and methods. The bioassays used were Daphnia magna and Hydraattenuata as animal models, Lactuca sativa and Pseudokirchneriella subcapitata as plant models, and Photobacterium leioghnathi asbacterial model. To meet this objective, selection criteria of the organisms evaluated and cluster analysis were used to identify the mostsensitive in the affluent and effluent of each plant. Results. All organisms are potentially useful in the assessment of water quality bymeeting four essential requirements and 17 desirable requirements equivalent to 100% acceptability, except P. leioghnathi which doesnot meet two essential requirements that are the IC50 for the toxic reference and the confidence interval. The animal, plant and bacterialmodels showed different levels of sensitivity at the entrance and exit of the water treatment systems. Conclusions. H. attenuata, P.subcapitata and P. leioghnathi were the most effective organisms in detecting toxicity levels in the affluents and D. magna, P. subcapitataand P. leioghnathi in the effluents.

  16. RNA-dependent RNA polymerase 1 in potato (Solanum tuberosum) and its relationship to other plant RNA-dependent RNA polymerases. (United States)

    Hunter, Lydia J R; Brockington, Samuel F; Murphy, Alex M; Pate, Adrienne E; Gruden, Kristina; MacFarlane, Stuart A; Palukaitis, Peter; Carr, John P


    Cellular RNA-dependent RNA polymerases (RDRs) catalyze synthesis of double-stranded RNAs that can serve to initiate or amplify RNA silencing. Arabidopsis thaliana has six RDR genes; RDRs 1, 2 and 6 have roles in anti-viral RNA silencing. RDR6 is constitutively expressed but RDR1 expression is elevated following plant treatment with defensive phytohormones. RDR1 also contributes to basal virus resistance. RDR1 has been studied in several species including A. thaliana, tobacco (Nicotiana tabacum), N. benthamiana, N. attenuata and tomato (Solanum lycopersicum) but not to our knowledge in potato (S. tuberosum). StRDR1 was identified and shown to be salicylic acid-responsive. StRDR1 transcript accumulation decreased in transgenic potato plants constitutively expressing a hairpin construct and these plants were challenged with three viruses: potato virus Y, potato virus X, and tobacco mosaic virus. Suppression of StRDR1 gene expression did not increase the susceptibility of potato to these viruses. Phylogenetic analysis of RDR genes present in potato and in a range of other plant species identified a new RDR gene family, not present in potato and found only in Rosids (but apparently lost in the Rosid A. thaliana) for which we propose the name RDR7.

  17. A Bayesian integrated population dynamics model to analyze data for protected species

    Directory of Open Access Journals (Sweden)

    Hoyle, S. D.


    Full Text Available Managing wildlife-human interactions demands reliable information about the likely consequences of management actions. This requirement is a general one, whatever the taxonomic group. We describe a method for estimating population dynamics and decision analysis that is generally applicable, extremely flexible, uses data efficiently, and gives answers in a useful format. Our case study involves bycatch of a protected species, the Northeastern Offshore Spotted Dolphin (Stenella attenuata, in the tuna fishery of the eastern Pacific Ocean. Informed decision-making requires quantitative analyses taking all relevant information into account, assessing how bycatch affects these species and how regulations affect the fisheries, and describing the uncertainty in analyses. Bayesian analysis is an ideal framework for delivering information on uncertainty to the decision-making process. It also allows information from other populations or species or expert judgment to be included in the analysis, if appropriate. Integrated analysis attempts to include all relevant data for a population into one analysis by combining analyses, sharing parameters, and simultaneously estimating all parameters, using a combined objective function. It ensures that model assumptions and parameter estimates are consistent throughout the analysis, that uncertainty is propagated through the analysis, and that the correlations among parameters are preserved. Perhaps the most important aspect of integrated analysis is the way it both enables and forces consideration of the system as a whole, so that inconsistencies can be observed and resolved.

  18. Comparison of the sensitivity of seven marine and freshwater bioassays as regards antidepressant toxicity assessment. (United States)

    Minguez, Laetitia; Di Poi, Carole; Farcy, Emilie; Ballandonne, Céline; Benchouala, Amira; Bojic, Clément; Cossu-Leguille, Carole; Costil, Katherine; Serpentini, Antoine; Lebel, Jean-Marc; Halm-Lemeille, Marie-Pierre


    The hazards linked to pharmaceutical residues like antidepressants are currently a major concern of ecotoxicology because they may have adverse effects on non-target aquatic organisms. Our study assesses the ecotoxicity of three antidepressants (fluoxetine, sertraline and clomipramine) using a battery of marine and freshwater species representing different trophic levels, and compares the bioassay sensitivity levels. We selected the following bioassays: the algal growth inhibition test (Skeletonema marinoi and Pseudokirchneriella subcapitata), the microcrustacean immobilization test (Artemia salina and Daphnia magna), development and adult survival tests on Hydra attenuata, embryotoxicity and metamorphosis tests on Crassostrea gigas, and in vitro assays on primary cultures of Haliotis tuberculata hemocytes. The results showed high inter-species variability in EC50-values ranging from 43 to 15,600 µg/L for fluoxetine, from 67 to 4,400 µg/L for sertraline, and from 4.70 µg/L to more than 100,000 µg/L for clomipramine. Algae (S. marinoi and P. subcapitata) and the embryo-larval stages of the oyster C. gigas were the most sensitive taxa. This raises an issue due to their ecological and/or economic importance. The marine crustacean A. salina was the least sensitive species. This difference in sensitivity between bioassays highlights the importance of using a test battery.

  19. Links Between Ethylene and Sulfur Nutrition-A Regulatory Interplay or Just Metabolite Association? (United States)

    Wawrzynska, Anna; Moniuszko, Grzegorz; Sirko, Agnieszka


    Multiple reports demonstrate associations between ethylene and sulfur metabolisms, however the details of these links have not yet been fully characterized; the links might be at the metabolic and the regulatory levels. First, sulfur-containing metabolite, methionine, is a precursor of ethylene and is a rate limiting metabolite for ethylene synthesis; the methionine cycle contributes to both sulfur and ethylene metabolism. On the other hand, ethylene is involved in the complex response networks to various stresses and it is known that S deficiency leads to photosynthesis and C metabolism disturbances that might be responsible for oxidative stress. In several plant species, ethylene increases during sulfur starvation and might serve signaling purposes to initiate the process of metabolism reprogramming during adjustment to sulfur deficit. An elevated level of ethylene might result from increased activity of enzymes involved in its synthesis. It has been demonstrated that the alleviation of cadmium stress in plants by application of S seems to be mediated by ethylene formation. On the other hand, the ethylene-insensitive Nicotiana attenuata plants are impaired in sulfur uptake, reduction and metabolism, and they invest their already limited S into methionine needed for synthesis of ethylene constitutively emitted in large amounts to the atmosphere. Regulatory links of EIN3 and SLIM1 (both from the same family of transcriptional factors) involved in the regulation of ethylene and sulfur pathway, respectively, is also quite probable as well as the reciprocal modulation of both pathways on the enzyme activity levels.

  20. Links Between Ethylene and Sulfur Nutrition—A Regulatory Interplay or Just Metabolite Association? (United States)

    Wawrzynska, Anna; Moniuszko, Grzegorz; Sirko, Agnieszka


    Multiple reports demonstrate associations between ethylene and sulfur metabolisms, however the details of these links have not yet been fully characterized; the links might be at the metabolic and the regulatory levels. First, sulfur-containing metabolite, methionine, is a precursor of ethylene and is a rate limiting metabolite for ethylene synthesis; the methionine cycle contributes to both sulfur and ethylene metabolism. On the other hand, ethylene is involved in the complex response networks to various stresses and it is known that S deficiency leads to photosynthesis and C metabolism disturbances that might be responsible for oxidative stress. In several plant species, ethylene increases during sulfur starvation and might serve signaling purposes to initiate the process of metabolism reprogramming during adjustment to sulfur deficit. An elevated level of ethylene might result from increased activity of enzymes involved in its synthesis. It has been demonstrated that the alleviation of cadmium stress in plants by application of S seems to be mediated by ethylene formation. On the other hand, the ethylene-insensitive Nicotiana attenuata plants are impaired in sulfur uptake, reduction and metabolism, and they invest their already limited S into methionine needed for synthesis of ethylene constitutively emitted in large amounts to the atmosphere. Regulatory links of EIN3 and SLIM1 (both from the same family of transcriptional factors) involved in the regulation of ethylene and sulfur pathway, respectively, is also quite probable as well as the reciprocal modulation of both pathways on the enzyme activity levels. PMID:26648954

  1. Reverse genetics in ecological research.

    Directory of Open Access Journals (Sweden)

    Jens Schwachtje

    Full Text Available By precisely manipulating the expression of individual genetic elements thought to be important for ecological performance, reverse genetics has the potential to revolutionize plant ecology. However, untested concerns about possible side-effects of the transformation technique, caused by Agrobacterium infection and tissue culture, on plant performance have stymied research by requiring onerous sample sizes. We compare 5 independently transformed Nicotiana attenuata lines harboring empty vector control (EVC T-DNA lacking silencing information with isogenic wild types (WT, and measured a battery of ecologically relevant traits, known to be important in plant-herbivore interactions: phytohormones, secondary metabolites, growth and fitness parameters under stringent competitive conditions, and transcriptional regulation with microarrays. As a positive control, we included a line silenced in trypsin proteinase inhibitor gene (TPI expression, a potent anti-herbivore defense known to exact fitness costs in its expression, in the analysis. The experiment was conducted twice, with 10 and 20 biological replicates per genotype. For all parameters, we detected no difference between any EVC and WT lines, but could readily detect a fitness benefit of silencing TPI production. A statistical power analyses revealed that the minimum sample sizes required for detecting significant fitness differences between EVC and WT was 2-3 orders of magnitude larger than the 10 replicates required to detect a fitness effect of TPI silencing. We conclude that possible side-effects of transformation are far too low to obfuscate the study of ecologically relevant phenotypes.

  2. Auxin Is Rapidly Induced by Herbivore Attack and Regulates a Subset of Systemic, Jasmonate-Dependent Defenses1[OPEN (United States)

    Machado, Ricardo A. R.; Robert, Christelle A. M.; Arce, Carla C. M.; Ferrieri, Abigail P.; Jimenez-Aleman, Guillermo H.


    Plant responses to herbivore attack are regulated by phytohormonal networks. To date, the role of the auxin indole-3-acetic acid (IAA) in this context is not well understood. We quantified and manipulated the spatiotemporal patterns of IAA accumulation in herbivore-attacked Nicotiana attenuata plants to unravel its role in the regulation of plant secondary metabolism. We found that IAA is strongly, rapidly, and specifically induced by herbivore attack. IAA is elicited by herbivore oral secretions and fatty acid conjugate elicitors and is accompanied by a rapid transcriptional increase of auxin biosynthetic YUCCA-like genes. IAA accumulation starts 30 to 60 s after local induction and peaks within 5 min after induction, thereby preceding the jasmonate (JA) burst. IAA accumulation does not require JA signaling and spreads rapidly from the wound site to systemic tissues. Complementation and transport inhibition experiments reveal that IAA is required for the herbivore-specific, JA-dependent accumulation of anthocyanins and phenolamides in the stems. In contrast, IAA does not affect the accumulation of nicotine or 7-hydroxygeranyllinalool diterpene glycosides in the same tissue. Taken together, our results uncover IAA as a rapid and specific signal that regulates a subset of systemic, JA-dependent secondary metabolites in herbivore-attacked plants. PMID:27485882

  3. 陕西红脂大小蠹天敌种类调查%The investigation of natural enemies of Dendroctonus valens in Shaanxi

    Institute of Scientific and Technical Information of China (English)

    王培新; 贺虹; 李健康; 邢建宏; 李孟楼


    对陕西红脂大小蠹Dendroctonus valens LeConte危害区的天敌种类调查表明,寄生于红脂大小蠹的病原真菌共有5种,其中幼虫期有头孢霉Cephalosporium sp.、球孢白僵菌Beauveria bassiana和拟卵孢霉Ovulariopsis sp.,成虫期有球孢白僵菌Beauveria bassiana、枝顶孢霉Acremonium sp.、头孢霉Cephalosporium sp.、木霉Trichoderma sp.4种,其中以球孢白僵菌和枝顶孢霉Acremonium sp.的致病能力最为显著.捕食性天敌昆虫主要有西岳蛇蛉Agulla xiyue Yang et Chou、日本弓背蚁Camponotus japionicus Mayr、中华红林蚁Formica sinensis Wheeler、蚁形郭公甲Thanasimus formicarius(L.)及纤细阎甲Platysoma attenuata(LeConte),它们对红脂大小蠹均有较明显的控制作用.寄生性天敌主要有1种寄生蝇和1种茧蜂.

  4. Full establishment of arbuscular mycorrhizal symbiosis in rice occurs independently of enzymatic jasmonate biosynthesis.

    Directory of Open Access Journals (Sweden)

    Caroline Gutjahr

    Full Text Available Development of the mutualistic arbuscular mycorrhiza (AM symbiosis between most land plants and fungi of the Glomeromycota is regulated by phytohormones. The role of jasmonate (JA in AM colonization has been investigated in the dicotyledons Medicago truncatula, tomato and Nicotiana attenuata and contradicting results have been obtained with respect to a neutral, promotive or inhibitory effect of JA on AM colonization. Furthermore, it is currently unknown whether JA plays a role in AM colonization of monocotyledonous roots. Therefore we examined whether JA biosynthesis is required for AM colonization of the monocot rice. To this end we employed the rice mutant constitutive photomorphogenesis 2 (cpm2, which is deficient in JA biosynthesis. Through a time course experiment the amount and morphology of fungal colonization did not differ between wild-type and cpm2 roots. Furthermore, no significant difference in the expression of AM marker genes was detected between wild type and cpm2. However, treatment of wild-type roots with 50 μM JA lead to a decrease of AM colonization and this was correlated with induction of the defense gene PR4. These results indicate that JA is not required for AM colonization of rice but high levels of JA in the roots suppress AM development likely through the induction of defense.

  5. Evaluación preliminar de toxicidad, genotoxicidad y actividad antimicrobiana de Sida rhombifolia L. Preliminary evaluation of Sida rhombifolia L. toxicity, genotoxicity and antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Brugés Keile


    Full Text Available La actual predisposición a consumir productos naturales y, en muchas regiones, la difícil disponibilidad y accesibilidad a los medicamentos han llevado a las poblaciones del mundo a buscar otras alternativas para aliviar sus dolencias. Una de las más difundidas ha sido el regreso a la medicina ancestral, lo cual ha provocado un aumento en el consumo de fitoterapéuticos. En Colombia, el uso de los fitomedicamentos está muy extendido y, dentro de ellos, en esta investigación se  seleccionó la planta Sida rhombifolia L. a la cual se le realizó la evaluación de la toxicidad de extractos y fracciones utilizando como organismos de prueba Daphnia magna, Hydra attenuata y Artemia salina. La actividad biológica fue evaluada mediante la prueba de sensibilidad a antimicrobianos y la genotoxicidad con el ensayo Cometa. Los ensayos de toxicidad aguda con los organismos de prueba muestran que los extractos acuosos son prácticamente no tóxicos (CL50 >1000 ppm, lo cual sugiere que su uso en forma de infusión es seguro. Los extractos etanólicos y las fracciones de acetato de etilo y cloroformo presentaron actividad antimicrobiana frente a Staphylococcus aureus y Pseudomonas aeruginosa que puede ser atribuida a los metabolitos secundarios (terpenoides, flavonoides que están presentes en esta especie. Los extractos etanólicos presentaron una importante actividad genotóxica sobre los linfocitos en el ensayo Cometa, siendo el extracto etanólico de raíces el que presenta mayor genotoxicidad (CL50 35 ppm. Es importante señalar que el extracto acuoso de hojas presenta una baja genotoxicidad (CL50 900 ppm, lo cual es relevante si se toma en consideración que es la parte de la planta tradicionalmente utilizada por las comunidades indígenas ubicadas en la Sierra Nevada de Santa Marta. The current tendency to consume more natural products and difficult availability of and access to medicines in many regions has led the world’s population to seek

  6. Preliminary Study on Vertical Spatial Niche of Small Mammals in Shangrila County of Yunnan Province%香格里拉县小型兽类垂直空间生态位初步研究

    Institute of Scientific and Technical Information of China (English)

    刘正祥; 洪梅; 杨桂荣; 宋志忠; 高子厚; 孙绍华; 徐友谊


    2011年6~7月采用铗夜法,对云南香格里拉县海拔2500~4500 m范围内的小型兽类进行了调查,并分析了群落中各物种的空间生态位宽度指数和生态位重叠指数大小与其沿海拔梯度分布的关系及对空间资源的利用状况.共捕获19种275只小型兽类,其中社鼠(Niviventer confucianus)、中华姬鼠(Apodemus draco)、大耳姬鼠(A.latronum)、齐氏姬鼠(A.chevrieri)、藏鼠兔(Ochotona thibetana)、西南绒鼠(Eothenomys custos)和大足鼠(Rattus nitidus)分布的海拔梯度跨度最大,分布范围较广,占据垂直空间生态位宽,是当地小型兽类群落的优势种.19种小型兽类的空间生态位重叠幅度差异很大,大绒鼠(E.miletus)、灰麝鼩(Crocidura attenuata)、中麝鼩(C.russula vorax)的空间生态位完全重叠;大足鼠、齐氏姬鼠与滇攀鼠(Vernany fulva)、克氏田鼠(Microtus clarkei)、隐纹花松鼠(Tamiops swinhoei)、珀氏长吻松鼠(Dremomys pernyi)、灰鼯鼠(Petaurista xanthatis)、印度长尾鼩(Soriculus leucops)空间生态位完全不重叠.%Small mammals were trapped in altitude range of 2 500-4 500 m in Shangrila from June to July 2011 to analyzed the spatial niche breadth of each species and niche overlap between species.A total of 19 species of 275 small mammal specimen was captured,among them Niviventer confucianus,Apodemus draco,A.latronum,A.chevrieri,Ochotona thibetana,Eothenomys custos,and Rattus nitidus were species that distribute most widely at altitude range,therefore they were dominant species in the small mammal community at local area.The spatial niche overlap between the 19 small mammals varied greatly.The spatial niche of E.miletus,Crocidura attenuata and C.russula vorax completely overlapped,while the special niche of R.nitidus,A.chevrieri,Vernany fulva,Microtus clarkei,Tamiops swinhoei,Dremomys pernyi,Petaurista xanthotis and Soriculus leucops were not overlapped.

  7. Cetacean records along São Paulo state coast, Southeastern Brazil

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    Marcos César de Oliveira Santos


    Full Text Available The São Paulo state (SP coast (23º18'S, 44º42'W; 25º14'S, 48º01'W is of approximately 600 km in length, bordering the Western Atlantic Ocean, in southeastern Brazil. Cetacean sightings and strandings have long been observed throughout this area. Scattered data from scientific publications, skeletal remains in museums, photographs and articles from newspaper files, universities and aquaria have been organised and updated since 1993. Field investigations on strandings and sightings have also been conducted. A total of 29 cetacean species have been recorded, including 7 baleen whales (Mysticeti and 22 toothed whales (Odontoceti, as follows: Balaenoptera physalus, B. borealis, B. edeni, B. acutorostrata, B. bonaerensis, Megaptera novaeangliae, Eubalaena australis, Physeter macrocephalus, Kogia breviceps, K. sima, Berardius arnuxii, Mesoplodon europaeus, M. mirus, Ziphius cavirostris, Orcinus orca, Feresa attenuata, Globicephala melas, G. macrorhynchus, Pseudorca crassidens, Delphinus capensis, Lagenodelphis hosei, Steno bredanensis, Tursiops truncatus, Stenella frontalis, S. longirostris, S. coeruleoalba, Lissodelphis peronii, Sotalia guianensis and Pontoporia blainvillei. Several species have been observed only once and include strays from their areas of common distribution, as well as species with known preferences for offshore distribution. Others, such as P. blainvillei and S. guianensis, are common coastal dwellers year-round. Z. cavirostris, P. crassidens and L. hosei are reported for the first time on the SP coast.A costa do Estado de São Paulo (SP (23º18'S, 44º42'O; 25º14'S, 48º01'O apresenta aproximadamente 600 km de extensão voltada para o Oceano Atlântico Ocidental no sudeste do Brasil. Registros de encalhes e de avistamentos de cetáceos vêm sendo realizados ao longo desse litoral. Desde 1993, dados obtidos em literatura científica, material osteológico encontrado em museus, fotografias e artigos de arquivos de jornais

  8. Actividad molusquicida del Piquerol A aislado de Piqueria trinervia (compositae sobre ocho especies de caracoles pulmonados The molluscicide activity of Piquerol A isolated from Piqueria trinervia (Compositae against eight species of pulmonate snails

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    Alejandro Cruz-Reys


    Full Text Available De las partes aéreas de la planta Piqueria trinervia (Compositae colectada en diveresas áereas de México, se aisló el Piquerol A. Este compuesto se probó como agente molusquicida contra ocho especies de caracoles pulmonados: Fossaria (Fossaria humilis, F. (Bakerilymnae sp., Pseudosuccinea columella, Stagnicola attenuata, de México; F. (B. cubensis y Physacubensis, de Cuba; P. Columella y Biomphalaria glabrata, de Brasil; B glabrata, de Puerto Rico; S. elodes, de Estados Unidos. Se utilizaron tres concentraciones 50, 25 y 5 ppm para cada una de las especies y 2 períodos de exposición, 6 y 24 horas, a 20-22ºC. En 50 ppm, después de 6 horas, y 25 ppm, después de 24 horas los ejemplares de todas las especies murieron. En 5 ppm después de 24 horas, se observaron mortalidades de 60 a 100%. En ningún caso se observó recuperación después de la exposición por 24 horas. El piquerol A es un terpeno biodegradable que presenta otras actividades biológicas. No se han hecho pruebas de toxicidad en otros animales ni pruebas de campo. Sin embargo, es una substacia con alto potencial de uso como molusquicida en zonas de transmisión focal. Es la primera que en México se hacen estudios sistemáticos sobre molusquicidas de origen vegetal.In laboratory trials an aqueous solution of Piquerol A from Piqueria trinervia, collected in several regions of Mexico, showed a molluscicide action on the adults of eight different pulmonates snails species. Fossaria (Fossaria humilis, F. (Bakerilymnaea sp., Pseudosuccinea columella and Stagnicola attenuata from Mexico; F. (B. cubensis and Physa cubensis from Cuba; P. columella and Biomphalaria glabrata from Brazil; B. glabrata from Puerto Rico; and S. elodes from USA. The solution was tested at 50, 25 and 5 ppm concentration, for two periods of 6 and 24 hours, at room temperature (20-22ºC. A 100% mortality was obtained for all species at 50 ppm concentration after 6 hours of exposure; the same percentage at 25

  9. Microscale ecotoxicity testing of Moselle river watershed (Lorraine Province, France sediments

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    Jean François Férard


    Full Text Available The ecotoxic potential of seven Moselle river watershed sediments was assessed with a battery of bioassays comprised of rapid phototrophic [LuminoTox solid phase (L-SPA and elutriate (L-ELU assays] and bacterial [Microtox solid phase assay (M-SPA] exposure tests, as well as with two micro-invertebrate solid phase tests conducted with Hydra attenuata (lethal and sublethal effects solid phase assay, HL-SPA and HSL-SPA and Chironomus riparius. Measured effects of sediments and their elutriates were varied and reflected responses that were ecotoxicity test-, endpoint- and site-dependent, suggesting some degree of risk toward benthic and water column organisms, respectively, at specific sites. Correlation analysis demonstrated that L-SPA and M-SPA ecotoxicity responses were significantly linked with the Hydra HSL-SPA assay, indicating their ability to predict ecotoxicity towards an invertebrate taxonomic group representing secondary consumers. While the L-SPA and M-SPA assays hold promise as rapid screens for sediment ecotoxicity, correlation analysis with grain size (L-SPA: r=-0.795, P=0.033; M-SPA: r=-0.73, P=0.07 points out that their responses can be influenced by the presence of fines (i.e., sediment particles ≤0.063 mm in size and that this information is essential to properly interpret ecotoxicity data generated with these assays. Finally, notable differences observed in trophic level sensitivities once again recall the importance of employing a test battery to adequately appraise the ecotoxicity of sediments.

  10. The physical characteristics and usage patterns of stone axe and pounding hammers used by long-tailed macaques in the Andaman Sea region of Thailand. (United States)

    Gumert, Michael D; Kluck, Marius; Malaivijitnond, Suchinda


    Stone hammering in natural conditions has been extensively investigated in chimpanzees and bearded capuchins. In contrast, knowledge of stone tool use in wild Old World monkeys has been limited to anecdotal reports, despite having known for over 120 years that Macaca fascicularis aurea use stone tools to process shelled foods from intertidal zones on islands in the Andaman Sea. Our report is the first scientific investigation to look at the stone tools used by these macaques. We observed they were skilled tool users and used stone tools daily. They selected tools with differing qualities for differing food items, and appeared to use at least two types of stone tools. Pounding hammers were used to crush shellfish and nuts on anvils and axe hammers were used to pick or chip at oysters attached to boulders or trees. We found significant physical differences between these two tools. Tools at oyster beds were smaller and exhibited scarring patterns focused more often on the points, whereas tools found at anvils were larger and showed more scarring on the broader surfaces. We also observed grip differences between the two tool types. Lastly, macaques struck targets with axe hammers more rapidly and over a wider range of motion than with pounding hammers. Both our behavioral and lithic data support that axe hammers might be used with greater control and precision than pounding hammers. Hand-sized axe hammers were used for controlled chipping to crack attached oysters, and larger pounding hammers were used to crush nuts and unattached shellfish on anvils. In addition to stones, they also used hand-sized auger shells (Turritella attenuata) as picks to axe attached oysters. Pound hammering appears similar to the stone tools used by chimpanzees and capuchins, but axe hammering has not yet been documented in other nonhuman primates in natural conditions.

  11. Activated carbon from pyrolysed sugarcane bagasse: Silver nanoparticle modification and ecotoxicity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Gonçalves, Suely Patrícia C., E-mail: [Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), CEP 13083-970 Campinas, SP (Brazil); Strauss, Mathias; Delite, Fabrício S. [Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), CEP 13083-970 Campinas, SP (Brazil); Clemente, Zaira [Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), CEP 13083-970 Campinas, SP (Brazil); Laboratory of Ecotoxicology and Biosafety, Embrapa, CEP 13820-000 Jaguariúna, SP (Brazil); Castro, Vera L. [Laboratory of Ecotoxicology and Biosafety, Embrapa, CEP 13820-000 Jaguariúna, SP (Brazil); Martinez, Diego Stéfani T., E-mail: [Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), CEP 13083-970 Campinas, SP (Brazil); School of Technology, University of Campinas (UNICAMP), CEP 13484-332 Limeira, SP (Brazil)


    Activated carbon from pyrolysed sugarcane bagasse (ACPB) presented pore size ranges from 1.0 to 3.5 nm, and surface area between 1200 and 1400 m{sup 2} g{sup −1} that is higher than commonly observed to commercial activated carbon. The ACPB material was successfully loaded with of silver nanoparticles with diameter around 35 nm (0.81 wt.%). X-ray photoelectron spectroscopy (XPS) analyses showed that the material surface contains metallic/Ag{sup 0} (93.60 wt.%) and ionic/Ag{sup +} states (6.40 wt.%). The adsorption capacity of organic model molecules (i.e. methylene blue and phenol) was very efficient to ACPB and ACPB loaded with silver nanoparticles (ACPB-AgNP), indicating that the material modification with silver nanoparticles has not altered its adsorption capacity. ACPB-AgNP inhibited bacteria growth (Escherichia coli), it is a promising advantage for the use of these materials in wastewater treatment and water purification processes. However, ACPB-AgNP showed environmental risks, with toxic effect to the aquatic organism Hydra attenuata (i.e. LC50 value of 1.94 mg L{sup −1}), and it suppressed root development of Lycopersicum esculentum plant (tomato). Finally, this work draw attention for the environmental implications of activated carbon materials modified with silver nanoparticles. - Highlights: • Production of very efficient activated carbon by pyrolysis process of sugarcane bagasse. • Modification of activated carbon with silver nanoparticles to environmental remediation and water purification. • Activated carbon modified with silver nanoparticles showed acute ecotoxic effects.

  12. Ecotoxicity of selected nano-materials to aquatic organisms. (United States)

    Blaise, C; Gagné, F; Férard, J F; Eullaffroy, P


    Present knowledge concerning the ecotoxic effects of nano-materials is very limited and merits to be documented more fully. For this purpose, we appraised the toxicity of nine metallic nano-powders (copper zinc iron oxide, nickel zinc iron oxide, yttrium iron oxide, titanium dioxide, strontium ferrite, indium tin oxide, samarium oxide, erbium oxide, and holmium oxide) and of two organic nano- powders (fullerene-C60 and single-walled carbon nanotube or SWCNT). After a simple process where nano-powders (NPs) were prepared in aqueous solution and filtered, they were then bioassayed across several taxonomic groups including decomposers (bacteria), primary producers (micro-algae), as well as primary and secondary consumers (micro-invertebrates and fish). Toxicity data generated on the 11 NPs reflected a wide spectrum of sensitivity that was biological level-, test-, and endpoint-specific. With all acute and chronic tests confounded for these 11 NPs, toxicity responses spanned over three orders of magnitude: >463 mg/L (24 h LC50 of the invertebrate Thamnoplatyurus platyurus for fullerene-C60) / 0.3 mg/L (96 h EC50 of the invertebrate Hydra attenuata for indium tin oxide), that is a ratio of 1543. On the basis of the MARA (Microbial Array for Risk Assessment) assay toxic fingerprint concept, it is intimated that NPs may have different modes of toxic action. When mixed in a 1:1 ratio with a certified reference material (CRM) sediment, two solid phase assays and an elutriate assay, respectively, showed that five NPs (copper zinc iron oxide, samarium oxide, erbium oxide, holmium oxide, and SWCNT) were able to increase both CRM sediment toxicity and its elutriate toxicity. This initial investigation suggests that chemicals emerging from nanotechnology may pose a risk to aquatic life in water column and sediment compartments and that further studies on their adverse effects are to be encouraged.

  13. Diversity and Distribution Patterns of Cetaceans in the Subtropical Southwestern Atlantic Outer Continental Shelf and Slope (United States)

    Di Tullio, Juliana Couto; Gandra, Tiago B. R.; Zerbini, Alexandre N.; Secchi, Eduardo R.


    Temporal and spatial patterns of cetacean diversity and distribution were investigated through eight ship-based surveys carried out during spring and autumn between 2009 and 2014 on the outer continental shelf (~150m) and slope (1500m) off southeastern and southern Brazil (~23°S to ~34°S). The survey area was divided into southeast and south areas according to their oceanographic characteristics. Twenty-one species were observed in 503 sightings. The overall number of species was similar between the two areas, though it was higher in the spring in the south area. Five species were dominant and diversity varied more seasonally than spatially. ANOVA and kernel analyses showed that overall cetacean densities were higher in spring compared to autumn. Physeter macrocephalus, the most frequent species, concentrated throughout the south area at depths over 1000m in both seasons. Despite the overlapped occurrence at a broader scale, small delphinids presented latitudinal and in-offshore gradients as well as seasonal variation in distribution patterns, which could indicate habitat partitioning between some species. Delphinus delphis was only recorded in the south and its density decreased in areas where the presence of Stenella frontalis increased, mainly beyond the 250m isobath. Densities of S. longirostris and S. attenuata increased in lower latitudes and beyond the shelf break. The large delphinids Tursiops truncatus and Globicephala melas formed mixed groups in many occasions and were observed along the study area around depths of 500m. Grampus griseus was twice as frequent in the south area and densities increased in waters deeper than 600m. As expected, densities of both small and large migratory whales were higher during spring, over the continental slope, in the southeast area. The results presented here provided strong evidence on the importance of the outer continental shelf and slope to a diverse community of cetaceans occurring in the subtropical Southwestern

  14. An ecological analysis of the herbivory-elicited JA burst and its metabolism: plant memory processes and predictions of the moving target model.

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    William Stork

    Full Text Available BACKGROUND: Rapid herbivore-induced jasmonic acid (JA accumulation is known to mediate many induced defense responses in vascular plants, but little is known about how JA bursts are metabolized and modified in response to repeated elicitations, are propagated throughout elicited leaves, or how they directly influence herbivores. METHODOLOGY/PRINCIPAL FINDINGS: We found the JA burst in a native population of Nicotiana attenuata to be highly robust despite environmental variation and we examined the JA bursts produced by repeated elicitations with Manduca sexta oral secretions (OS at whole- and within-leaf spatial scales. Surprisingly, a 2(nd OS-elicitation suppressed an expected JA burst at both spatial scales, but subsequent elicitations caused more rapid JA accumulation in elicited tissue. The baseline of induced JA/JA-Ile increased with number of elicitations in discrete intervals. Large veins constrained the spatial spread of JA bursts, leading to heterogeneity within elicited leaves. 1(st-instar M. sexta larvae were repelled by elicitations and changed feeding sites. JA conjugated with isoleucine (JA-Ile translates elicitations into defense production (e.g., TPIs, but conjugation efficiency varied among sectors and depended on NaWRKY3/6 transcription factors. Elicited TPI activity correlated strongly with the heterogeneity of JA/JA-Ile accumulations after a single elicitation, but not repeated elicitations. CONCLUSIONS/SIGNIFICANCE: Ecologically informed scaling of leaf elicitation reveals the contribution of repeated herbivory events to the formation of plant memory of herbivory and the causes and importance of heterogeneity in induced defense responses. Leaf vasculature, in addition to transmitting long-distance damage cues, creates heterogeneity in JA bursts within attacked leaves that may be difficult for an attacking herbivore to predict. Such unpredictability is a central tenet of the Moving Target Model of defense, which posits that

  15. Illuminating a plant's tissue-specific metabolic diversity using computational metabolomics and information theory. (United States)

    Li, Dapeng; Heiling, Sven; Baldwin, Ian T; Gaquerel, Emmanuel


    Secondary metabolite diversity is considered an important fitness determinant for plants' biotic and abiotic interactions in nature. This diversity can be examined in two dimensions. The first one considers metabolite diversity across plant species. A second way of looking at this diversity is by considering the tissue-specific localization of pathways underlying secondary metabolism within a plant. Although these cross-tissue metabolite variations are increasingly regarded as important readouts of tissue-level gene function and regulatory processes, they have rarely been comprehensively explored by nontargeted metabolomics. As such, important questions have remained superficially addressed. For instance, which tissues exhibit prevalent signatures of metabolic specialization? Reciprocally, which metabolites contribute most to this tissue specialization in contrast to those metabolites exhibiting housekeeping characteristics? Here, we explore tissue-level metabolic specialization in Nicotiana attenuata, an ecological model with rich secondary metabolism, by combining tissue-wide nontargeted mass spectral data acquisition, information theory analysis, and tandem MS (MS/MS) molecular networks. This analysis was conducted for two different methanolic extracts of 14 tissues and deconvoluted 895 nonredundant MS/MS spectra. Using information theory analysis, anthers were found to harbor the most specialized metabolome, and most unique metabolites of anthers and other tissues were annotated through MS/MS molecular networks. Tissue-metabolite association maps were used to predict tissue-specific gene functions. Predictions for the function of two UDP-glycosyltransferases in flavonoid metabolism were confirmed by virus-induced gene silencing. The present workflow allows biologists to amortize the vast amount of data produced by modern MS instrumentation in their quest to understand gene function.

  16. Illuminating a plant’s tissue-specific metabolic diversity using computational metabolomics and information theory (United States)

    Li, Dapeng; Heiling, Sven; Baldwin, Ian T.


    Secondary metabolite diversity is considered an important fitness determinant for plants’ biotic and abiotic interactions in nature. This diversity can be examined in two dimensions. The first one considers metabolite diversity across plant species. A second way of looking at this diversity is by considering the tissue-specific localization of pathways underlying secondary metabolism within a plant. Although these cross-tissue metabolite variations are increasingly regarded as important readouts of tissue-level gene function and regulatory processes, they have rarely been comprehensively explored by nontargeted metabolomics. As such, important questions have remained superficially addressed. For instance, which tissues exhibit prevalent signatures of metabolic specialization? Reciprocally, which metabolites contribute most to this tissue specialization in contrast to those metabolites exhibiting housekeeping characteristics? Here, we explore tissue-level metabolic specialization in Nicotiana attenuata, an ecological model with rich secondary metabolism, by combining tissue-wide nontargeted mass spectral data acquisition, information theory analysis, and tandem MS (MS/MS) molecular networks. This analysis was conducted for two different methanolic extracts of 14 tissues and deconvoluted 895 nonredundant MS/MS spectra. Using information theory analysis, anthers were found to harbor the most specialized metabolome, and most unique metabolites of anthers and other tissues were annotated through MS/MS molecular networks. Tissue–metabolite association maps were used to predict tissue-specific gene functions. Predictions for the function of two UDP-glycosyltransferases in flavonoid metabolism were confirmed by virus-induced gene silencing. The present workflow allows biologists to amortize the vast amount of data produced by modern MS instrumentation in their quest to understand gene function. PMID:27821729

  17. A simple, flexible and high-throughput cloning system for plant genome editing via CRISPR-Cas system. (United States)

    Kim, Hyeran; Kim, Sang-Tae; Ryu, Jahee; Choi, Min Kyung; Kweon, Jiyeon; Kang, Beum-Chang; Ahn, Hyo-Min; Bae, Suji; Kim, Jungeun; Kim, Jin-Soo; Kim, Sang-Gyu


    CRISPR-Cas9 system is now widely used to edit a target genome in animals and plants. Cas9 protein derived from Streptococcus pyogenes (SpCas9) cleaves double-stranded DNA targeted by a chimeric single-guide RNA (sgRNA). For plant genome editing, Agrobacterium-mediated T-DNA transformation has been broadly used to express Cas9 proteins and sgRNAs under the control of CaMV 35S and U6/U3 promoter, respectively. We here developed a simple and high-throughput binary vector system to clone a 19-20 bp of sgRNA, which binds to the reverse complement of a target locus, in a large T-DNA binary vector containing an SpCas9 expressing cassette. Two-step cloning procedures: (1) annealing two target-specific oligonucleotides with overhangs specific to the AarI restriction enzyme site of the binary vector; and (2) ligating the annealed oligonucleotides into the two AarI sites of the vector, facilitate the high-throughput production of the positive clones. In addition, Cas9-coding sequence and U6/U3 promoter can be easily exchanged via the Gateway(TM) system and unique EcoRI/XhoI sites on the vector, respectively. We examined the mutation ratio and patterns when we transformed these constructs into Arabidopsis thaliana and a wild tobacco, Nicotiana attenuata. Our vector system will be useful to generate targeted large-scale knock-out lines of model as well as non-model plant.

  18. Diversity of

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    Mohamed M. Abou Zaid


    Full Text Available Seasonal abundance, biomass, and taxonomic composition of copepods in El-Mex Bay (Southeastern Mediterranean region were studied from autumn 2011 to 2012. Most species within the copepod communities displayed a clear pattern of succession throughout the investigation period. Generally copepods were the predominant group. They contributed numerically 57% of the total zooplankton counts with an average of 5083 organisms/m3 and a total number of 203,333 individuals. The bay harbored 50 species belonging to 28 genera within 19 families and 4 orders under one class. Calanoids were represented by 24 species which formed 31.6% of total copepods predominantly Acartia clausi, Calocalanus pavo, Clausocalanus furcatus, Eucalanus crassus, Nannocalanus minor, Paracalanus parvus, Eucalanus subcrassus, and Temora longicornis. Cyclopoids comprised 13 species of which Acanthocyclops americanus, Halicyclops magniceps, Oithona attenuata, and Oithona nana were the most abundant adult copepods. Eleven Harpacticoid species were also recorded with Euterpina acutifrons, Microsetella norvegica, Onychocamptus mohammed being the most prevalent. It was found however, that two Poecilostomatoida species were rarely encountered in the plankton Oncaea minuta and Corycaeus typicus. Copepod larvae and copepodite stages formed the main bulk of copepod Fauna as noticed in the El-Mex Bay during the investigation period. Their percentage was 36.7% of the total count and their total numbers were 74,629 individuals with an average of 1866 organisms/m3. The persistent relationships between total copepod counts, copepod orders, and physico-chemical variables suggested that physical factors operate on the copepod communities, either directly to limit maximum distribution along the bay, or indirectly on abundance.

  19. Revision of Poliaspis (Hemiptera, Coccoidea, Diaspididae, with descriptions of 8 new species from Australia

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    Nate Hardy


    Full Text Available Eight new Australian species of Poliaspis are described and illustrated: P. alluvia sp. n., P. araucariae sp. n., P. ceraflora sp. n., P. naamba sp. n., P. nalbo sp. n., P. narungga sp. n., P. ozothamnae sp. n., and P. waibenensis sp. n. Two described species are transferred into Poliaspis and are redescribed and illustrated: Lineaspis callitris (Laing originally described by Laing as a species of Poliaspis, is transferred back into Poliaspis as P. callitris Laing comb. rev., and Leonardaspis wilga (Leonardi is transferred to Poliaspis as P. wilga (Leonardi comb. n. Descriptions and illustrations are also provided for six of the fourteen previously-named Poliaspis species, including five from Australia: P. attenuata Brimblecombe, P. elongata Brimblecombe, P. exocarpi Maskell, P. nitens Fuller, and P. syringae Laing. Both P. cycadis Comstock and P. gaultheriae Green become junior synonyms of P. media Maskell. The species not treated here are P. intermedia Fuller (the location of the types is unknown and Fuller’s description is inadequate, P. casuarinicola Lindinger (missing types, P. incisa Takagi and de Faveri (recently, and well described in Takagi and de Faveri 2011, and the six New Zealand species recently revised by Henderson (2011. In addition, Laingaspis lanigera (Laing, the adult female of which has 8 clusters of perivulvar pores – as in Poliaspis species – is redescribed and illustrated. Lectotypes are designated for L. lanigera, P. callitris, P. exocarpi, P. media, and P. wilga. A key is provided to the species of Poliaspis, excluding P. casuarinicola and P. intermedia but including P. incisa and the New Zealand species: P. chathamica Henderson, P. floccosa Henderson, P. lactea (Maskell, P. media Maskell, P. raouliae Henderson and P. salicornicola Henderson.

  20. 基于层次分析法对姜黄属植物的观赏应用综合评价%Ornamental evaluation of Curcuma based on analytic hierarchy process

    Institute of Scientific and Technical Information of China (English)

    许丽珍; 吴永辉; 岳保超; 刘念


    运用层次分析法对姜黄属(CurcumaL.)植物的10个种12份材料进行了鲜切花应用、盆栽观花应用、盆栽观叶应用与地栽应用等方面的观赏特性综合评价,并对就该12份材料的株高、花梗长度、花梗粗度、花序长度、花序直径等28个单项指标进行了综合考察评分,按评分标准计算其综合得分.结果显示,在姜黄属植物的观赏应用上,上部苞片先端颜色与花序直径是较为重要的评价指标;在观赏应用综合评价上,等级为I的有大莪术(C.elata)、春秋姜黄(C.attenuata)的顶生花与侧生花、南昆山莪术(C.nankunshanensis)的顶生花与侧生花、顶花莪术(C.yunnanensis),其中大莪术得分最高,是开发应用的首选种类.南岭莪术(C.kwangsiensis var.nanlingensis、姜黄(C.longa、红艳郁金(C.rubescens)、Curcuma sp.1、Curcuma sp.2被评定为等级Ⅱ,Curcuma sp.2、姜黄较其他得分高.郁金因其花色淡,花梗长度短,开花率低等因素,总体得分明显落后其他种,被评定为等级Ⅲ.

  1. Using the knowns to discover the unknowns: MS-based dereplication uncovers structural diversity in 17-hydroxygeranyllinalool diterpene glycoside production in the Solanaceae. (United States)

    Heiling, Sven; Khanal, Santosh; Barsch, Aiko; Zurek, Gabriela; Baldwin, Ian T; Gaquerel, Emmanuel


    Exploring the diversity of plant secondary metabolism requires efficient methods to obtain sufficient structural insights to discriminate previously known from unknown metabolites. De novo structure elucidation and confirmation of known metabolites (dereplication) remain a major bottleneck for mass spectrometry-based metabolomic workflows, and few systematic dereplication strategies have been developed for the analysis of entire compound classes across plant families, partly due to the complexity of plant metabolic profiles that complicates cross-species comparisons. 17-hydroxygeranyllinalool diterpene glycosides (HGL-DTGs) are abundant defensive secondary metabolites whose malonyl and glycosyl decorations are induced by jasmonate signaling in the ecological model plant Nicotiana attenuata. The multiple labile glycosidic bonds of HGL-DTGs result in extensive in-source fragmentation (IS-CID) during ionization. To reconstruct these IS-CID clusters from profiling data and identify precursor ions, we applied a deconvolution algorithm and created an MS/MS library from positive-ion spectra of purified HGL-DTGs. From this library, 251 non-redundant fragments were annotated, and a workflow to characterize leaf, flower and fruit extracts of 35 solanaceous species was established. These analyses predicted 105 novel HGL-DTGs that were restricted to Nicotiana, Capsicum and Lycium species. Interestingly, malonylation is a highly conserved step in HGL-DTG metabolism, but is differentially affected by jasmonate signaling among Nicotiana species. This MS-based workflow is readily applicable for cross-species re-identification/annotation of other compound classes with sufficient fragmentation knowledge, and therefore has the potential to support hypotheses regarding secondary metabolism diversification.

  2. Príspevok k topografickému výskumu malakofauny okresu Levice

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    Jozef Šteffek


    Full Text Available The paper brings new information on mollusc distribution of Levice District in southern part of Central Slovakia. The data were obtained from 14 localities, which lie mainly in the vicinity of the Ipeľ River and southern slopes of Štiavnické vrchy Mts. Together 78 mollusc species (50 land species and 28 fresh-water species were found. From 9 localities a litter sample from 1m2 was analyzed for quantitative evaluation of snail assemblages. Malacocoenoses of thermophilous forest mollusc species were determined in the area of Štiavnické vrchy Mts. foothill (localities 2, 7, 8. The species Limacus flavus, Euconulus praticola, Pisidium amnicum and Unio crassus albensis are important from the viewpoint of nature conservation and geographical distribution. Carpathian species Bythinella austriaca, Vestia turgida, Bielzia coerulans and also European forest species Merdigera obscura reach the southern boundary of their natural area of occurrence. Typical for this region are malacocoenoses of xeric biotopes, composed from species of 4–6 ecoelement – Cecilioides acicula, Cepaea vindobonensis, Granaria frumentum, Chondrula tridens, Xerolenta obvia, Truncatellina cylindrica, Cochlicopa lubricella and Monacha cartusiana. High diversity was observed by freshwater malacocoenoses. Anodonta anatina attenuata, A. cygnea solearis, Unio tumidus zelebori, Radix ampla are typical for stagnant water biotopes (abandoned ‘paleopotamon’ side arms. In slow flowing waters of the Ipeľ River beside the common species also rare species like Anisus septemgyratus and Pisidium amnicum were detected. Interesting is also the occurrence of strong population of invasive species of Asian mussel Sinanodonta woodiana, which is known to infiltrate into a number of streams all around Slovakia.

  3. Circadian rhythms in floral scent emission

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    Myles eFenske


    Full Text Available To successfully recruit pollinators, plants often release attractive floral scents at specific times of day to coincide with pollinator foraging. This timing of scent emission is thought to be evolutionarily beneficial to maximize resource efficiency while attracting only useful pollinators. Temporal regulation of scent emission is tied to the activity of the specific metabolic pathways responsible for scent production. Although floral volatile profiling in various plants indicated a contribution by the circadian clock, the mechanisms by which the circadian clock regulates timing of floral scent emission remained elusive. Recent studies using two species in the Solanaceae family provided initial insight into molecular clock regulation of scent emission timing. In Petunia hybrida, the benzenoid/phenylpropanoid (FVBP pathway is the major metabolic pathway that produces floral volatiles. Three MYB-type transcription factors, ODORANT1 (ODO1, EMISSION OF BENZENOIDS I (EOBI, and EOBII, all of which show diurnal rhythms in mRNA expression, act as positive regulators for several enzyme genes in the FVBP pathway. Recently, in P. hybrida and Nicotiana attenuata, homologs of the Arabidopsis clock gene LATE ELONGATED HYPOCOTYL (LHY have been shown to have a similar role in the circadian clock in these plants, and to also determine the timing of scent emission. In addition, in P. hybrida, PhLHY directly represses ODO1 and several enzyme genes in the FVBP pathway during the morning as an important negative regulator of scent emission. These findings facilitate our understanding of the relationship between a molecular timekeeper and the timing of scent emission, which may influence reproductive success.

  4. 四川青川县地震灾后鼠类群落结构及其动态%Community Structure and Dynamics of Rodents After Great Earthquake in Qingchuan of China's Sichuan

    Institute of Scientific and Technical Information of China (English)

    杨创明; 杨孔; 张建漂; 李平; 杨艾琳


    [目的]掌握青川县林地和农房区2种生境中鼠类群落结构及其动态,为防治灾后青川县鼠类暴发、农业鼠害发生提供理论参考.[方法]于2009年10月(秋)至2011年1 0月(秋),采用夹夜法对青川县林地和农房区2种生境中鼠类群落结构及其动态进行调查.[结果]在农房区和林地捕获的鼠类包括啮齿目(Rodentia)和鼩鼱目(Soricomorpha),共11个物种,分别为褐家鼠(Rattus norvegicus)、大足鼠(Rattus nitidus)、黄胸鼠(Rattus tanezumi)、社鼠(Niviventer confucianus)、小泡巨鼠(Leopoldamys edwardsi)、小家鼠(Mususculus),龙姬鼠(Apodemus draco)、高山姬鼠(Apodemus chevrieri)、巢鼠(Micromys minutus)、黑暖绒鼠(Eothenomys melanogaster)、灰麝鼩(Crocidura attenuata).在农房区,2010年4月以前,大足鼠是第一优势种,其相对密度呈下降趋势,2010年7月之后以家鼠为主,其中优势种黄胸鼠相对密度呈增长趋势,其余物种相对密度较低.在林地中,灰麝鼩和龙姬鼠是整个调查期间的优势种,其中龙姬鼠相对密度呈周期性变化;2010年4月以前,灰麝鼩为林地第一优势种,其种群相对密度呈下降趋势;2010年10月捕获了5种鼠类,其种群相对密度均达到当年峰值,并第一次捕获了小泡巨鼠和高山姬鼠,其后高山姬鼠成为林地优势种之一.相对林地而言,农房区鼠类群落多样性、均匀度、丰富度和优势度指数变化幅度较大.林地鼠类群落均匀度指数在2010年7月之前呈上升趋势,而后趋于稳定.2011年1月以后,林地鼠类群落丰富度指数和多样性指数逐步上升,而群落优势度下降.[结论]灾后农房区鼠类群落结构变化较大:2009年10月,大足鼠和灰麝鼩相对密度较大,其后下降;2010年7月后家鼠成为农房区主要鼠类,优势种黄胸鼠相对密度呈上升趋势.林地中鼠类群落结构相对稳定,龙姬鼠相对密度呈周期性变化.应加强对农房区黄胸鼠等家鼠

  5. Studies on the Community Structures of Meiofauna and Marine Nematode at Six Stations in the Southern Yellow Sea, China

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    HUANG Yong; ZHANG Zhinan; LIU Xiaoshou


    Meiofauna (0.031-0.5 mm) were sampled and studied at a grid of six stations during the cruise of investigation for over winter ground of anchovy (Engraulis japonicus) in the Southern Yellow Sea, China in January 2003. Total meiofauna individuals averaged (1.162± 0.347) × 106 ind m-2 and the corresponding biomass 1.748 ± 0.72 g dwt m-2 with the maximum2.35 g dwtm-2 at Station 9594 and the minimum 0.537 g dwt m-2 at Station 11794. A total of fourteen taxa were identified.Free living marine nematodes were the most dominant group with an average abundance of (1.026 ± 0.206) × 106 indm-2, accounting for 88.5% of total numbers, and an average of 85.4% lived in the surface layer (0-2cm) of sediments. The individual dry weight was calculated, which ranges from 0.01μg to 31.32μg with an average of 0.261μg. One hundred and forty two species or taxa of free-living marine nematodes belonging to 89 genera, 24 families and 4 orders were identified. Six of them were new species. The common dominant species were Dorylaimopsis rabalaisi, Sphaerolaimus balticus, Sphaerolaimus minitus, Metalinhomoeus longicauda, Prochromadorella attenuata., Campylaimus sp. 1, Vasostoma sp. 1, Daptonema normandicum, Paramonohystera riemanni, and Promonhystera sp. 1. According to cluster analysis of Primer 5.0, the six stations were clustered into 2 groups with similar species composition at 40% similarity. The species diversity index (H), evenness index (J) and species richness index (d) of nematode were calculated and analyzed. Correlation analysis with respect to environmental factors showed that the abundance of meiofauna had a significant correlation with the median diameter of sediment (Mdφ). The species richness of nematodes had a highly significant correlation with Chl-a and significant correlations with Pha-a and Chl-a + Pha-a.

  6. 基于13个内含子的序列探讨鲸目的系统发育关系%Molecular phylogenetics of cetaceans: an insight from 13 nuclear intron sequences

    Institute of Scientific and Technical Information of China (English)

    熊晔; 周旭明; 杨梅; 张盼; 杨云霞; 杨光


    本文基于实验室筛选得到的13对内含子标记,在鲸偶蹄目的15个物种中进行有效扩增,并重建了这15个物种的系统发育关系.结果表明,抹香鲸总科(Physeteroidea)位于齿鲸亚目(Odontoceti)的基部,从而支持了传统的齿鲸亚目的单系性.在海豚总科(Delphinoidea)内部,贝斯分析结果支持了鼠海豚科(Phocoenidae)和一角鲸科(Monodontidae)的姐妹群关系,而后再与海豚科(Delphinidae)相聚.系统发育分析同时还强烈支持了海豚科的四个属(Sousa,Tursiops,Stenella,Delphinus)组成一个单系的"复合体".另外,我们的分析结果并不支持瓶鼻海豚属(Tursiops)和原海豚属(Stenella)的单系性.基于松散分子钟的分歧时间估算与以往文献中的结果没有明显差异.这些研究结果提示,核基因内含子序列有希望解决一些长期存在的鲸类系统发育问题.%Sequences of 13 introns from 15 Cetartiodactyla species were determined to reveal the phylogeny of cetaceans.Our results support the monophyly of the traditionally accepted suborder Odontoceti ( toothed whales ), placing the dwarf sperm whale ( Kogia sima), a representative species of superfamily Physeteroidea, as sister to other toothed whales. Within the superfamily Delphinoidea, phylogenetic analyses identified a sister relationship between Delphinidae and Monodontidae + Phocoenidae. A close relationship among four genera ( Sousa, Tursiops, Stenella, and Delphinus) is strongly supported,which suggested the monophyly of the Sousa-Stenella-Tursiops-Delphinus complex. Neither the two Tursiops species ( T.truncates and T. aduncus ) nor the two Stenella species (S. coeruleoalba and S. attenuata ) examined in present study clustered together, which strongly supported the paraphyly of these two genera as suggested in previous studies. Furthermore,the present Bayesian inference with a lognormal relaxed molecular clock provided divergence time for each clade, which is consistent with

  7. Regulation of RNA-dependent RNA polymerase 1 and isochorismate synthase gene expression in Arabidopsis.

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    Lydia J R Hunter

    Full Text Available BACKGROUND: RNA-dependent RNA polymerases (RDRs function in anti-viral silencing in Arabidopsis thaliana and other plants. Salicylic acid (SA, an important defensive signal, increases RDR1 gene expression, suggesting that RDR1 contributes to SA-induced virus resistance. In Nicotiana attenuata RDR1 also regulates plant-insect interactions and is induced by another important signal, jasmonic acid (JA. Despite its importance in defense RDR1 regulation has not been investigated in detail. METHODOLOGY/PRINCIPAL FINDINGS: In Arabidopsis, SA-induced RDR1 expression was dependent on 'NON-EXPRESSER OF PATHOGENESIS-RELATED GENES 1', indicating regulation involves the same mechanism controlling many other SA- defense-related genes, including pathogenesis-related 1 (PR1. Isochorismate synthase 1 (ICS1 is required for SA biosynthesis. In defensive signal transduction RDR1 lies downstream of ICS1. However, supplying exogenous SA to ics1-mutant plants did not induce RDR1 or PR1 expression to the same extent as seen in wild type plants. Analysing ICS1 gene expression using transgenic plants expressing ICS1 promoter:reporter gene (β-glucuronidase constructs and by measuring steady-state ICS1 transcript levels showed that SA positively regulates ICS1. In contrast, ICS2, which is expressed at lower levels than ICS1, is unaffected by SA. The wound-response hormone JA affects expression of Arabidopsis RDR1 but jasmonate-induced expression is independent of CORONATINE-INSENSITIVE 1, which conditions expression of many other JA-responsive genes. Transiently increased RDR1 expression following tobacco mosaic virus inoculation was due to wounding and was not a direct effect of infection. RDR1 gene expression was induced by ethylene and by abscisic acid (an important regulator of drought resistance. However, rdr1-mutant plants showed normal responses to drought. CONCLUSIONS/SIGNIFICANCE: RDR1 is regulated by a much broader range of phytohormones than previously thought

  8. Feeding ecology of the Stomiiformes (Pisces) of the northern Mid-Atlantic Ridge. 1. The Sternoptychidae and Phosichthyidae (United States)

    Carmo, Vanda; Sutton, Tracey; Menezes, Gui; Falkenhaug, Tone; Bergstad, Odd Aksel


    Comprehensive trophic studies in the vast mid-oceanic regions are rare compared to coastal and fisheries-oriented investigations. Field sampling conducted by the multidisciplinary, international Census of Marine Life project MAR-ECO, namely the 2004 G.O. Sars cruise, has generated one of the largest open ocean deep-pelagic sample collections ever obtained. With the overall goal of understanding carbon flow processes within and through the deep-pelagic nekton associated with the northern Mid-Atlantic Ridge system (N MAR), quantitative trophic analyses were conducted in order to identify the major intraspecific patterns in diet of characteristic members of the midwater fish community. Diets of five abundant species of zooplanktivorous fishes were examined in detail in terms of prey taxonomy and variability in space, ontogeny and diel cycle. Two major patterns of feeding were identified. Pattern 1 included three species preying primarily on copepods, Argyropelecus hemigymnus, Maurolicus muelleri and Vinciguerria attenuata, the former two of which revealed spatial differences in diet with latitude, mostly likely related to latitudinal prey distributions and densities. Maurolicus demonstrated ecological differences in diet that mirrored phenotypic variation North and South of the Subpolar Front, an 'oceanic species concept' question that warrants further research. Pattern 2 included two species feeding primarily on amphipods, Argyropelecus aculeatus and Sternoptyx diaphana, both of which showed ontogenetic variability in feeding primarily related to specific amphipod taxon sizes, rather than prey switching to other major prey taxa. This is the first study that highlights the importance of amphipods in the diets of these species. All fish species showed selectivity in prey choice, possibly related to competition with the other major nekton components along the N MAR, namely the Myctophidae and other zooplanktivorous Stomiiformes. Daily ration fell within the expected

  9. Estimation of Heritability and Combining Ability for Growth, Stem-Straightness and Wood Density of the F1 Generation of Pinus taeda × P.caribaea%火炬松×加勒比松F1代生长、树干通直度和基本密度遗传和配合力分析

    Institute of Scientific and Technical Information of China (English)

    栾启福; 姜景民; 张建忠; 张守攻


    @@ 松类杂种直到20世纪中期才开始被培育利用,如窄果松X辐射松(Pinus attenuata X P.radiata)、欧洲落叶松X日本落叶松(Larix decidua×L.kaempferi)等(Dungey,2001).%The genetic characteristics and combining ability for growth, stem-straightness and wood density were estimated on 16 seven-year-old F1 families derived from crossing with 4 female and 4 male parents of Pinus taeda × P.caribaea with the NC Ⅱ mating design.Analysis of variance showed that there were significant differences( P < 0.01 ) in growth and wood basic density among 16 crosses, and ( P < 0.05 ) in stem-straightness.The heritability ( h2 ) analysis showed that family mean heritability of growth, stem-straightness and wood density for female parents was higher than that for male parents, while the mean h2 for the full-sib families was in the middle of the parents' heritability.The h2 of growth was 0.292 3 -0.469 9 for female parents, and 0.191 9 -0.403 3 for male parents.The family mean and single tree h2 of wood basic density for female parents was 0.176 4 and 0.034 6, respectively, and the single tree h2 of stem-straightness for male and female parents was 0.162 7 and 0.098 3, respectively.The heritability of DBH and volume was increasing in the last 6 years while the heritability of tree height was decreasing.The analysis of genetic correlation showed that growth traits had positive correlation ( |rG| = 0.467 2 -0.351 6) with stem-form, and had a negative one( |rG| = 0.220 30.679 8 ) with wood basic density.The general combining ability (GCA) effect of male or female parents for growth traits and stem-straightness was significantly different, and their special combining ability (SCA) effect for wood basic density was significant.The effective value of combining ability for GCA and SCA was estimated and the better parents and hybrids were evaluated.The correlation between genetic background of the parents and genetic differences of the progenies was discussed.

  10. Response of marine copepods to a changing tropical environment: winners, losers and implications

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    Li Lee Chew


    Full Text Available Background. Climate change concurrent with anthropogenic disturbances can initiate serial changes that reverberate up the food chain with repercussions for fisheries. To date, there is no information available concerning the combined effects of global warming and human impacts on tropical marine food webs. While temperate copepods respond differently to warming and environmental stressors, the extent to which tropical copepods can adapt to rising temperature of already warm waters remains unknown. We hypothesize that sea warming and other anthropogenic disturbances over the long term will have the greatest impact on the copepod community in nearshore waters where their effects are accentuated, and therefore vulnerable and resilient species could be identified. Methods. Zooplankton samples were collected during two time periods (1985–86 and 2014–15 interposed by marked anthropogenic disturbances, and at the same five stations located progressively from inshore to offshore in Klang Strait, Malaysia, following the asymmetrical before-after-control-impact (BACI design. Copepods were identified to species, and results were interpreted by univariate (ANOVA and multivariate (PERMANOVA, PCO analyses of the computed species abundance and diversity measures. Results. Copepod total abundance was not significantly different among stations but higher after disturbance than before disturbance. However, changes in the abundance of particular species and the community structure between time periods were dramatic. Coastal large-bodied calanoid species (e.g., Acartia spinicauda, Calanopia thompsoni, Pseudodiaptomus bowmani and Tortanus forcipatus were the most vulnerable group to disturbance. This however favored the opportunistic species (e.g., Oithona simplex, O. attenuata, Hemicyclops sp., Pseudomacrochiron sp. and Microsetella norvegica. Small-bodied copepods (e.g., Paracalanus sp., Parvocalanus crassirostris and Euterpina acutifrons were unaffected

  11. Myxomycete diversity of the Patagonian Steppe and bordering areas in Argentina

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    Lado, Carlos


    Full Text Available Biodiversity surveys for myxomycetes (Amoebozoa were carried out in three consecutive years (2009 to 2011 in the cold arid Patagonian Steppe, Argentina. The surveys, the first to cover such an extensive area in South America, form part of the Myxotropic project funded by the Spanish Government. Specimens were collected in 174 localities in four different provinces (Neuquén, Río Negro, Chubut and Santa Cruz, between 36° and 52° S latitudes. The most common types of substrate investigated were the dominant shrubs and grasses of the Patagonian steppe, and the Nothofagus forests, characteristic of the transition areas, but other plants such as small cacti and cushion plants were also included in the survey. A total of 133 different species and 5 varieties of myxomycetes representing 31 genera were identified in the 1134 specimens collected either in the field, or from moist chamber cultures prepared with samples of plant material obtained from the same collecting sites. The results include one species new to science, Perichaena nigra, and 17 species and two varieties that were previously unknown for either the Neotropics or South America, Badhamia armillata, Dianema mongolicum, Didymium annulisporum, D. leptotrychum, D. orthonemata, D. sturgisii, Echinostelium coelocephalum, Licea deplanata, L. nannengae, Macbrideola argentea, M. oblonga, Oligonema aurantium, Perichaena luteola, P. madagascariensis, Physarum luteolum, Protophysarum phloiogenum, Trichia contorta var. attenuata, T. contorta var. iowensis, T. erecta. An additional 19 species are new records for Argentina. These additions make Argentina the country in South America, at present, with the greatest number of myxomycetes catalogued having more than 50% of the species cited from the whole Neotropics. Diversity and biogeographic distribution of these organisms are discussed, and taxonomic comments on rare or unusual species are included and illustrated with photographs by LM and SEM. The

  12. Effect of adrenomedullin on the activity of barosensitive neurons in the rostral ventrolateral medulla of rats%肾上腺髓质素对大鼠延髓头端腹外侧区压力反射敏感神经元的作用

    Institute of Scientific and Technical Information of China (English)

    樊明欣; 李霞; 王锦; 曹银祥; 沈霖霖; 朱大年


    采用多管微电泳结合细胞外记录的方法研究了肾上腺髓质素(adrenomedullin,ADM)对大鼠延髓头端腹外侧区(rostral ventrolateral medulla,rVLM)压力反射敏感性神经元电活动的作用及其可能机制.结果显示:在29个rVLM压力反射敏感神经元中,20个神经元在30、60和90 nA的电流微电泳大鼠ADM(rADM)过程中,放电频率由(10.8±2.7)spikes/s分别增加到(14.6±3.6)、(19.8±4.7)和(31.9±6.4)spikes/s(P<0.05,n=20).微电泳rADM特异性受体阻断剂人ADM(human ADM,hADM)(22-52)可明显减小神经元放电频率的增加幅度,比正常放电频率仅增加15.4%[(11.4±2.5)sipkes/s,P<0.05,n=10],而降钙素基因相关肽1(CGRP1)受体阻断剂hCGRP(8-37)对rADM兴奋性神经元电活动影响较小.在另外23个神经元中,10个神经元的放电频率在10、20和40 nA电流微电泳神经型NOS(nNOS)抑制剂7-NiNa过程中放电减少,由正常的(10.1±3.5)spikes/s分别减少为(7.5±2.5)、(5.3±2.1)和(3.1±1.4)spikes/s(P<0.05,n=10).在微电泳7-NiNa过程中同时微电泳rADM,则rADM增加神经元放电频率的效应减弱,增加幅度为基础水平的17%[(6.2±1.9)spikes/s].8个神经元在10、20和40 nA电流微电泳诱导型NOS抑制剂(iNOS)aminoguanidine(AG)过程中放电频率由(11.5±5.1)spikes/s增加到(17.8±5.6)、(22.5±6.3)和(29.1±6.4)spikes/s(P<0.05,n=8),rADM与AG同时微电泳时,AG对rADM本身增加神经元放电的效应无明显影响.上述结果提示,rADM在rVLM可通过其特异性受体或来源于nNOS的NO作用于压力反射敏感神经元,使其活动增强而发挥调节心血管活动的作用.%To investigate the eletrophysiological effect of rat adrenomedullin (rADM) on barosensitive neurons in the rostral ventrolateral medulla (rVLM) and its potential mechanisms, the extracellular recording and multi-barrel iontophoresis methods were used. Of the 29 barosensitive neurons in the rVLM, 20 neurons demonstrated excitatory response to

  13. Larval fish distribution and their relationship with environmental factors in the southern Tyrrhenian Sea (central Mediterranean during two years of sampling

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    Adriana Profeta


    , Vi_a (Vinciguerria attenuata. Fig. 2. Results of CCA analysis for larval fish species and sampled stations during June 2006. Two first axes (CCA1 and CCA2 are represented . Species abbreviations in alphabetical order: Acto_ris (Arctozenus risso, Arno_tho (Arnoglossus thori, Boop_boo (Boops boops, Auxi_roc Cara_acu Cera_mad (Ceratoscopelus maderensis, Cyclo_bra (Cyclothone braueri, Diap_hol (Diaphus holti, Gobi_nig (Gobius niger, Heli_dac (Helicolenus dactylopterus, Hygo_hyg (Hygophum hygomii, Lamp_cro (Lampanyctus crocodilus, Lamp_pus (Lampanyctus pusillus, Lest_jay (Lestidiops jayakari, Myct_pun (Myctophum punctatum, Nezu_aeq (Nezumia aequalis Noto_bol (Notoscopelus bolini, Noto_elo (Notoscopelus elongatus, Para_spe (Paralepis speciosa, Sync_pha (Synchiropus phaeton Spic_sma (Spicara smaris, Trac_tra (Trachurus trachurus.

  14. Antarctic Starfish (Echinodermata, Asteroidea from the ANDEEP3 expedition

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    Bruno Danis


    Full Text Available This dataset includes information on sea stars collected during the ANDEEP3 expedition, which took place in 2005. The expedition focused on deep-sea stations in the Powell Basin and Weddell Sea.Sea stars were collected using an Agassiz trawl (3m, mesh-size 500µm, deployed in 16 stations during the ANTXXII/3 (ANDEEP3, PS72 expedition of the RV Polarstern. Sampling depth ranged from 1047 to 4931m. Trawling distance ranged from 731 to 3841m. The sampling area ranges from -41°S to -71°S (latitude and from 0 to -65°W (longitude. A complete list of stations is available from the PANGAEA data system (, including a cruise report ( dataset includes 50 records, with individual counts ranging from 1-10, reaching a total of 132 specimens.The andeep3-Asteroidea is a unique dataset as it covers an under-explored region of the Southern Ocean, and that very little information was available regarding Antarctic deep-sea starfish. Before this study, most of the information available focused on starfish from shallower depths than 1000m. This dataset allowed to make unique observations, such as the fact that some species were only present at very high depths (Hymenaster crucifer, Hymenaster pellucidus, Hymenaster praecoquis, Psilaster charcoti, Freyella attenuata, Freyastera tuberculata, Styrachaster chuni and Vemaster sudatlanticus were all found below -3770m, while others displayed remarkable eurybathy, with very high depths amplitudes (Bathybiaster loripes (4842m, Lysasterias adeliae (4832m, Lophaster stellans (4752m, Cheiraster planeta (4708m, Eremicaster crassus (4626m, Lophaster gaini (4560m and Ctenodiscus australis (4489m.Even if the number of records is relatively small, the data bring many new insights on the taxonomic, bathymetric and geographic distributions of Southern starfish, covering a very large sampling zone. The dataset also brings to light

  15. Vegetation-induced soil water repellency as a strategy in arid ecosystems. A geochemical approach in Banksia woodlands (SW Australia) (United States)

    Muñoz-Rojas, Miriam; Jiménez-Morillo, Nicasio T.; González-Pérez, Jose Antonio; Zavala, Lorena M.; Stevens, Jason; Jordan, Antonio


    Introduction Banksia woodlands (BW) are iconic ecosystems of Western Australia (WA) composed by an overstorey dominated by Proteaceae, e.g. Banksia menziesii and Banksia attenuata, in combination with other species, such as Eucalyptus spp., Verticordia spp. or Melaleuca spp. Although located in very poor dune soils, BW provide numerous ecosystem services and sustain a high biodiversity. In this area, annual rainfall is relatively high (about 800 mm) but permeability of the sandy substrate leads to a functionally arid ecosystem. Currently, BW are threatened by sand mining activities and urban expansion; therefore conservation and restoration of these woodlands are critical. Despite numerous efforts, the success of restoration plans is usually poor mostly due to the high sensitivity to drought stress and poor seedling survival rates (5-30%) (Benigno et al., 2014). A characteristic feature of BW is their root architecture, formed by a proteoid (cluster) system that spreads to form thick mats below the soil surface, favouring the uptake of nutrients (especially, P), and preventing soil erosion. Root exudates are related to numerous plant functions, as they facilitate penetration of roots in soil and enhance the extraction of scarce mineral nutrients and its further assimilation. Exudates may also interact directly with soil or indirectly through microbial mediated events being also related to soil water repellency (SWR; Lozano et al, 2014). Knowledge about the specific compounds able to induce SWR is limited (Doerr et al., 2000), but it is generally accepted that is caused by organic molecules coating the surface of soil mineral particles and aggregates (Jordán et al., 2013). Proteaceae release short-chained organic acids to enhance phosphate acquisition, which have been also reported to be related with SWR (Jiménez-Morillo et al., 2014). It is hypothesized that disruption of water dynamics in mature BW soils is underlying the failure of restoration plans. This

  16. Population dynamics and monitoring applied to decision-making

    Directory of Open Access Journals (Sweden)

    Conroy, M. J.


    influence diagrams to capture the stochastic, temporal processes of managing cheetah population in Kenya. The model predicts likely anagement decisions made by various actors within these countries, (e.g., the President, the Environmental Protection Agency, and rural residents and the resulting probability of cheetah extinction following these decisions. By approaching the problem in both its political and ecological contexts one avoids consideration of decisions that, while beneficial from a purely conservation point of view, are unlikely to be implemented because of conflicting political objectives. Haas’s analysis demonstrates both the promise and challenges of this type of modeling, and he offers suggestions for overcoming inherent technical difficulties such as model calibration. The second paper, by Simon Hoyle and Mark Maunder (Hoyle & Maunder, 2004, uses a Bayesian approach to model population dynamics and the effects of commercial fishing bycatch for the eastern Pacific Ocean spotted dolphin (Stenella attenuata. Their paper provides a good example of why Bayesian analysis is particularly suited to many management problems. Namely, because it allows the integration of disparate pieces of monitoring data in the simultaneous estimation of population parameters; allows forincorporation of expert judgment and data from other systems and species; and provides for explicit consideration of uncertainty in decision–making. Alternative management scenarios can then be explored via forward simulations. In the third paper, Chris Fonnesbeck and Mike Conroy (Fonnesbeck & Conroy, 2004 present an integrated approach for estimating parameters and predicting abundance of American black duck (Anas rubripes populations. They also employ a ayesian approach and overcome some of the computational challenges by using Markov chain–Monte Carlo methods. Ring–recovery and harvest data are used to estimate fall age ratios under alternative reproductive models. These in turn are used to