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1.
Janne Alahuhta Sarian Kosten Munemitsu Akasaka Dominique Auderset Mattia M. Azzella Rossano Bolpagni Claudia P. Bove Patricia A. Chambers Eglantine Chappuis John Clayton Mary de Winton Frauke Ecke Esperança Gacia Gana Gecheva Patrick Grillas Jennifer Hauxwell Seppo Hellsten Jan Hjort Mark V. Hoyer Christiane Ilg Agnieszka Kolada Minna Kuoppala Torben Lauridsen En Hua Li Balázs A. Lukács Marit Mjelde Alison Mikulyuk Roger P. Mormul Jun Nishihiro Beat Oertli Laila Rhazi Mouhssine Rhazi Laura Sass Christine Schranz Martin Søndergaard Takashi Yamanouchi Qing Yu Haijun Wang Nigel Willby Xiao Ke Zhang Jani Heino 《Journal of Biogeography》2017,44(8):1758-1769
2.
Temporary pools are numerous in coastal plains of Atlantic Morocco and have a rich and diverse flora. These habitats are increasingly
under pressure by man impact through grazing by domestic livestock and the development of annual crops in their catchments.
The objectives of this work were to evaluate the species richness and the species composition of the vegetation of a sample
of 30 pools in this region, in order to assess the structure of the vegetation within pools and to evaluate the role of environmental
and anthropogenic factors in their richness and species composition. The results highlighted the species richness of the pools
with 300 species found among which annual species were heavily dominant. The structure of the vegetation varied within pools
according to a topographical/flooding gradient and between pools in relation with the land use in the surrounding areas. Three
vegetation belts were recognized from the centre to the periphery of the pool. The total species richness per pool was not
found significantly related to environmental or anthropogenic factors. The species characteristics of the pools were found
mostly in the centre and their number affected by hydrological factors and land use in the pool and in the surrounding areas.
The species characteristics of woodland habitats and of agriculture crops were found mostly in the peripheral zone. Temporary
pools maintain specific communities of both aquatic and amphibious species, probably because of the selection induced by water
level variations. The peripheral zone, although often dominated by terrestrial species, is clearly interpreted as part of
the pool. It contains amphibious species highly characteristic of the pool for which the irregular flooding is a key environmental
factor which decreases competition. 相似文献
3.
4.
Homology modeling and molecular dynamics simulations of the N-terminal domain of wheat high molecular weight glutenin subunit 10 下载免费PDF全文
Cazalis R Aussenac T Rhazi L Marin A Gibrat JF 《Protein science : a publication of the Protein Society》2003,12(1):34-43
High molecular weight glutenin subunits (HMW-GS) are of a particular interest because of their biomechanical properties, which are important in many food systems such as breadmaking. Using fold-recognition techniques, we identified a fold compatible with the N-terminal domain of HMW-GS Dy10. This fold corresponds to the one adopted by proteins belonging to the cereal inhibitor family. Starting from three known protein structures of this family as templates, we built three models for the N-terminal domain of HMW-GS Dy10. We analyzed these models, and we propose a number of hypotheses regarding the N-terminal domain properties that can be tested experimentally. In particular, we discuss two possible ways of interaction between the N-terminal domains of the y-type HMW glutenin subunits. The first way consists in the creation of interchain disulfide bridges. According to our models, we propose two plausible scenarios: (1) the existence of an intrachain disulfide bridge between cysteines 22 and 44, leaving the three other cysteines free of engaging in intermolecular bonds; and (2) the creation of two intrachain disulfide bridges (involving cysteines 22-44 and cysteines 10-55), leaving a single cysteine (45) for creating an intermolecular disulfide bridge. We discuss these scenarios in relation to contradictory experimental results. The second way, although less likely, is nevertheless worth considering. There might exist a possibility for the N-terminal domain of Dy10, Nt-Dy10, to create oligomers, because homologous cereal inhibitor proteins are known to exist as monomers, homodimers, and heterooligomers. We also discuss, in relation to the function of the cereal inhibitor proteins, the possibility that this N-terminal domain has retained similar inhibitory functions. 相似文献
5.
Catharanthus roseus cell suspension cultures may accumulate large quantities of malate in the vacuolar space. Upon transfer into a fresh medium malate moves out of the vacuole. This compound is then oxidized and its assimilatory products (CO2 + HCO3?) are excreted into the medium. The malate concentration decreases concurrently with an intracellular accumulation of nitrate. The opposite time course changes in malate and nitrate concentrations can be slowed down by treatment with synthetic auxins and fusicoccin which increase the HCO3? concentration in the cytoplasm. A line of evidence is presented which shows that malate consumption is causally related with the uptake of nitrate. The involvement of a HCO3?/NO3? antiport is proposed. 相似文献
6.
Impact of land use in catchment and human activities on water, sediment and vegetation of Mediterranean temporary pools 总被引:2,自引:0,他引:2
Rhazi L Grillas P Toure AM Ham LT 《Comptes rendus de l'Académie des sciences. Série III, Sciences de la vie》2001,324(2):165-177
The vegetation and physical and chemical characteristics of the water and sediment in ten temporary pools submitted to various anthropogenic disturbance were studied in Morocco over two hydrological cycles (1997-1998 and 1998-1999). Results of multivariate and parametric analyses show that disturbance has a significant impact on water and sediment. Agriculture in the catchment resulted in higher levels of N and the use of detergent to higher levels of phosphorus in both water and sediment. Mineral extraction resulted in higher depth and longer duration of flooding. Vegetation characteristics were better correlated to hydrology (water depth, duration of flooding) than to nutrient variables. These results suggest that although agriculture in the catchment contribute in modifying the sediment characteristics, the impact on vegetation and its conservation value is limited. However, care should be taken of the long-term effects of agriculture through cumulative effects and of the possible consequences of changing the agricultural practices. 相似文献
7.
A composite photoresist has been developed for the direct photopatterning of electrodes useful as biochip substrates. The material is composed of SU-8 polymer added with graphite carbon filler which enables patterning of conductive thin films (22μm) on both glass substrate and transparency flexible film with a standard UV photolithography protocol. The resolution obtained using the conductive composite compared well with the bare resist, with lateral resolutions of 5 and 10μm for bare and conductive resists, respectively. The obtained electrodes, after an electrochemical pre-treatment, exhibited very good electrochemical behaviors, opening the path to various electrochemical detections and grafting possibilities. In order to demonstrate the potentialities of the developed material in the biosensors and biochips field, DNA probes were electrografted, using diazonium chemistry, directly at the composite photoresist surface. Target oligonucleotide interactions were detected using chemiluminescent labeling and a satisfactory detection limit of 0.25nM target sequence was demonstrated with a detection ranging over three orders of magnitude. 相似文献
8.
Rhazi N Delmarcelle M Sauvage E Jacquemotte F Devriendt K Tallon V Ghosez L Frère JM 《Protein science : a publication of the Protein Society》2005,14(11):2922-2928
The specificity of the Streptomyces R61 penicillin-sensitive D-Ala-D-Ala peptidase has been re-examined with the help of synthetic substrates. The products of the transpeptidation reactions obtained with Gly-L-Xaa dipeptides as acceptor substrates are themselves poor substrates of the enzyme. This is in apparent contradiction with the classically accepted specificity rules for D-Ala-D-Ala peptidases. The Gly-L-Xaa dipeptide is regenerated by both the hydrolysis and transpeptidation reactions. The latter reaction is observed when another Gly-L-Xaa peptide or D-Alanine are supplied as acceptors. Utilization of substrates in which the terminal -COO(-) group has been esterified or amidated shows that a free carboxylate is not an absolute prerequisite for activity. The results are discussed in the context of the expected reversibility of the transpeptidation reaction. 相似文献
9.
In plant, unusual fatty acids are produced by a limited number of species. The industrial benefits of these unusual structures have led several groups to study their production in transgenic plants. Their research results led to very modest accumulation in seeds which was largely due to a limited knowledge of the lipid metabolism and fatty acid transfer in plants. More specifically we need to better understand the substrate specificity and selectivity of acyltransferases which are required for the incorporation of these unusual fatty acids into storage triacylglycerols. In our studies we have compared the incorporation of [14C] Oleoyl-CoA and Branched Chain Acyls-CoA into [3H] LPA-C18:1 by the Lysophosphatidic acid Acyltransferase (LPAAT) from developing seeds of agronomic plants (flax (Linum usitatissimum) and rape (Brassica napus)) and from a plant capable of producing high amounts of hydroxy fatty acids (castor bean (Ricinus communis)). Our assays demonstrate that LPAATs of the three studied species (1) incorporated preferentially oleyl-CoA, (2) could incorporate cyclopropane acyl-CoA when added alone as a substrate, however very weakly for rapeseed and castor bean seeds, (3) presented a low capacity to incorporate methyl branched acyl-CoA when added alone as a substrate (4) weakly incorporated cyclopropane acyl-CoA and was unable to incorporate methyl branched acyl-CoA when presented with an equimolar mix of oleyl-CoA and branched chain acyl-CoA. In all cases, the LPAAT had a low affinity for branched chain acyl-CoAs. The results show that LPAAT activity from agronomic plants constitutes a bottleneck for the incorporation of branched Chain acyl-CoA into PA. 相似文献
10.
Physical soil disturbance and the hydrology of temporary pools affect the biomass, species composition and richness of plant
communities. Disturbance liberates sites for the random recruitment of new individuals. The addition of seeds modifies the
structure of the communities. In order to verify these hypotheses concerning the vegetation of temporary pools, an experiment
was carried out using 72 soil samples collected from a pool in Western Morocco and placed in containers. Three types of laboratory
treatments were applied, each combined with control treatments: soil disturbance (control/disturbed), hydrology (flooded,
saturated and dry) and seed addition (sowing/no sowing). The total biomass, the annual and perennial species richness were
calculated for each sample to test the effects of disturbance, hydrology and seed addition on the biomass and species richness
of the various plant communities. The results show that disturbance reduces the total biomass, especially of perennials, but
without significantly increasing the richness of annuals. Seed addition does not affect the total biomass and reduces total
richness only in saturated soil, where biomass production is high. The most extreme stress conditions (drought and flooding)
limit the abundance of species and therefore competition.
Guest editors: B. Oertli, R. Cereghino, A. Hull & R. Miracle
Pond Conservation: From Science to Practice. 3rd Conference of the European Pond Conservation Network, Valencia, Spain, 14–16
May 2008 相似文献