181 research outputs found
Overall Picture Of Expressed Heat Shock Factors In Glycine Max, Lotus Japonicusand Medicago Truncatula
Heat shock (HS) leads to the activation of molecular mechanisms, known as HS-response, that prevent damage and enhance survival under stress. Plants have a flexible and specialized network of Heat Shock Factors (HSFs), which are transcription factors that induce the expression of heat shock proteins. The present work aimed to identify and characterize the Glycine maxHSF repertory in the Soybean Genome Project (GENOSOJA platform), comparing them with other legumes (Medicago truncatulaand Lotus japonicus) in view of current knowledge of Arabidopsis thaliana. The HSF characterization in leguminous plants led to the identification of 25, 19 and 21 candidate ESTs in soybean, Lotusand Medicago, respectively. A search in the SuperSAGE libraries revealed 68 tags distributed in seven HSF gene types. From the total number of obtained tags, more than 70% were related to root tissues (water deficit stress libraries vs.controls), indicating their role in abiotic stress responses, since the root is the first tissue to sense and respond to abiotic stress. Moreover, as heat stress is related to the pressure of dryness, a higher HSF expression was expected at the water deficit libraries. On the other hand, expressive HSF candidates were obtained from the library inoculated with Asian Soybean Rust, inferring crosstalk among genes associated with abiotic and biotic stresses. Evolutionary relationships among sequences were consistent with different HSF classes and subclasses. Expression profiling indicated that regulation of specific genes is associated with the stage of plant development and also with stimuli from other abiotic stresses pointing to the maintenance of HSF expression at a basal level in soybean, favoring its activation under heat-stress conditions. © 2012, Sociedade Brasileira de Genética.35SUPPL.1247259Altschul, S.F., Gish, W., Miller, W., Myers, E.W., Lipman, D.J., Basic local alignment search tool (1990) J Mol Biol, 215, pp. 403-410Baniwal, S.K., Chan, K.Y., Scharf, K.-D., Nover, L., Role of heat stress transcription factor HsfA5 as specific repressor of HsfA4* (2007) J Biol Chem, 282, pp. 3605-3613Bharti, K., Schimidt, E., Lyck, R., Bublak, D., Scharf, K.-D., Isolation and characterization of HsfA3, a new heat stress transcription factor of Lycopersicon peruvianum (2000) Plant J, 22, pp. 355-365Bharti, K., von Koskull-Döring, P., Bharti, S., Kumar, P., Tintschl-Körbitzer, A., Treuter, E., Nover, L., Tomato heat stress transcription factor HsfB1 represents a novel type of general transcription coactivator with a histone-like motif interacting with HAC1/CBP (2004) Plant Cell, 16, pp. 1521-1535Efeoglu, B., Heat shock proteins and heat shock response in plants (2009) G U J Sci, 22, pp. 67-75Eisen, M.B., Spellman, P.T., Brown, P.O., Botstein, D., Cluster analysis and display of genome-wide expression patterns (1998) Proc Natl Acad Sci USA, 95, pp. 14863-14868Fehr, W.R., Caviness, C.E., Burmood, D.T., Pennington, I.S., Stage of development descriptions for soybeans, Glycine max (L.) 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Ames, Iowa State University of Science and Technology, IowaGlombitza, S., Dubuis, P.-H., Thulke, O., Welzl, G., Bovet, L., Götz, M., Affenzeller, M., Asnaghi, C., Crosstalk and differential response to abiotic and biotic stressors reflected at the transcriptional level of effector genes from secondary metabolism (2004) Plant Mol Biol, 54, pp. 817-835Heerklotz, D., Doring, P., Bonzelius, F., Winkelhaus, S., Nover, L., The balance of nuclear import and export determines the intracellular distribution and function of tomato heat stress transcription factor HsfA2 (2001) Mol Cell Biol, 21, pp. 1759-1768Hoagland, D., Arnon, D.I., The water culture method for growing plants without soil (1950) Calif Agric Exp Stn Circ, 347, pp. 1-32Hsu, S.-F., Lai, H.-C., Jinn, T.-L., Cytosol-localized heat shock factor-binding protein, AtHSBP, functions as a negative regulator of heat shock response by translocation to the nucleus and is required for seed development in Arabidopsis (2010) Plant Physiol, 153, pp. 773-784Hu, W., Hu, G., Han, B., Genome-wide survey and expression profiling of heat shock proteins and heat shock factors revealed overlapped and stress specific response under abiotic stresses in rice (2009) Plant Sci, 176, pp. 583-590Kido, E.A., Barbosa, P.K., Ferreira Neto, J.C.R., Pandolfi, V., Houllou-Kido, L.M., Crovella, S., Benko-Iseppon, A.M., Identification of plant protein kinases in response to abiotic and biotic stresses using SuperSAGE (2011) Curr Prot Pept Sci, 12, pp. 643-656Kotak, S., Port, M., Ganguli, A., Bicker, F., von Koskull-Doring, P., Characterization of C-terminal domains of Arabidopsis heat stress transcription factors (Hsfs) and identification of a new signature combination of plant class a Hsfs with AHA and NES motifs essential for activator function and intracellular localization (2004) Plant J, 39, pp. 98-112Kotak, S., Larkindale, J., Lee, U., von Koskull-Doring, P., Vierling, E., Scharf, K.D., Complexity of the heat stress response in plants (2007) Curr Opin Plant Biol, 10, pp. 310-316Li, H.-Y., Chang, C.-S., Lu, L.-S., Liu, C.-A., Chan, M.-T., Charng, Y.-Y., Over-expression of Arabidopsis thaliana heat shock factor gene (AtHsfA1b) enhances chilling tolerance in transgenic tomato (2004) Bot Bull Acad Sin, 44, pp. 129-140Li, M., Berendzen, K.W., Schoffl, F., Promoter specificity and interactions between early and late Arabidopsis heat shock factors (2010) Plant Mol Biol, 73, pp. 559-567McClean, P.E., Mamidi, S., McConnell, M., Chikara, S., Lee, R., Synteny mapping between common bean and soybean reveals extensive blocks of shared loci (2010) BMC Genomics, 11, pp. e184Miller, G., Mittler, R., Could heat shock transcription factors function as hydrogen peroxide sensors in plant? (2006) Ann Bot, 98, pp. 279-288Mittal, D., Chakrabarti, S., Sarkar, A., Singh, A., Grover, A., Heat shock factor gene family in rice: Genomic organization and transcript expression profiling in response to high temperature, low temperature and oxidative stresses (2009) Plant Physiol Biochem, 47, pp. 785-795Mochida, K., Yoshida, T., Sakurai, T., Yamaguchi-Shinozaki, K., Shinozaki, K., Tran, L.-S.P., In silico analysis of transcription factor repertoire and prediction of stress responsive transcription factors in soybean (2009) DNA Res, 16, pp. 353-369Mochida, K., Yoshida, T., Sakurai, T., Yamaguchi-Shinozaki, K., Shinozaki, K., Tran, L.-S.P., LegumeTFDB: An in-tegrative database of Glycine max, Lotus japonicus and Medicago truncatula transcription factors (2009) Bioinformatics, 26, pp. 290-291Nascimento, L.C., Costa, G.G.L., Binneck, E., Pereira, G.A.G., Caraz-Zolle, M.F., A web-based bioinformatics interface applied to Genosoja Project: Databases and pipelines (2012) Genet Mol Biol, 35 (SUPPL. 1), pp. 203-211Nover, L., Bharti, K., Doring, P., Mishra, S.K., Ganguli, A., Scharf, K.-D., Arabidopsis and the heat stress transcription factor world: How many heat stress transcription factors do we need? (2001) Cell Stress Chap, 6, pp. 177-189Pirkkala, L., Nykanen, I., Sistonen, L., Roles of the heat shock transcription factors in regulation of the heat shock response and beyond (2001) FASEB J, 15, pp. 1118-1131Ruelland, E., Zachowski, A., How plants sense temperature (2010) Environ Exp Bot, 69, pp. 225-232Sato, Y., Yokoya, S., Enhanced tolerance to drought stress in transgenic rice plants overexpressing a small heat-shock protein, sHSP17.7 (2008) Plant Cell Rep, 27, pp. 329-334Scharf, K.-D., Rose, S., Thierfelder, J., Nover, L., Two cDNAs for tomato heat stress transcription factors (1993) Plant Physiol, 102, pp. 1355-1356Scharf, K.-D., Rose, S., Zott, W., Schoffl, F., Nover, L., Three tomato genes code for heat stress transcription factors with a regionofremarkable homology to the DNA-binding domain of the yeast HSF (1990) EMBO J, 9, pp. 4495-4501Schöff, F., Prändl, R., Reindl, A., Regulation of the heat-shock response (1998) Plant Physiol, 117, pp. 1135-1141Sung, D.-Y., Kaplan, F., Lee, K.-J., Guy, C.L., Acquired tolerance to temperature extremes (2003) Trends Plant Sci, 8, pp. 179-187Swindell, W.R., Huebner, M., Weber, A.P., Transcriptional profiling of Arabidopsis heat shock proteins and transcription factors reveals extensive overlap between heat and non-heat stress response pathways (2007) BMC Genomics, 8, pp. e125Tamura, K., Peterson, D., Peterson, N., Stecher, G., Nei, M., Kumar, S., MEGA5: Molecular Evolutionary Genetics Analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods (2011) Mol Biol Evol, 28, pp. 2731-2739Treshow, M., (1970) Environment and Plant Response, p. 421. , McGraw-Hill Company, New YorkTreuter, E., Nover, L., Ohme, K., Scharf, K.-D., Promoter specificity and deletion analysis of three tomato heat stress transcription factors (1993) Mol Gen Genet, 240, pp. 113-125Yamada, K., Fukao, Y., Hayashi, M., Fukazawa, M., Suzuki, I., Nishimura, M., Cytosolic HSP90 regulated the heat shock response that is responsible for heat acclimation in Arabidopsis thaliana (2007) J Biol Chem, 282, pp. 37794-3780
Partonic flow and -meson production in Au+Au collisions at = 200 GeV
We present first measurements of the -meson elliptic flow
() and high statistics distributions for different
centralities from = 200 GeV Au+Au collisions at RHIC. In
minimum bias collisions the of the meson is consistent with the
trend observed for mesons. The ratio of the yields of the to those of
the as a function of transverse momentum is consistent with a model
based on the recombination of thermal quarks up to GeV/,
but disagrees at higher momenta. The nuclear modification factor () of
follows the trend observed in the mesons rather than in
baryons, supporting baryon-meson scaling. Since -mesons are
made via coalescence of seemingly thermalized quarks in central Au+Au
collisions, the observations imply hot and dense matter with partonic
collectivity has been formed at RHIC.Comment: 6 pages, 4 figures, submit to PR
Plasma Wakefield Acceleration with a Modulated Proton Bunch
The plasma wakefield amplitudes which could be achieved via the modulation of
a long proton bunch are investigated. We find that in the limit of long bunches
compared to the plasma wavelength, the strength of the accelerating fields is
directly proportional to the number of particles in the drive bunch and
inversely proportional to the square of the transverse bunch size. The scaling
laws were tested and verified in detailed simulations using parameters of
existing proton accelerators, and large electric fields were achieved, reaching
1 GV/m for LHC bunches. Energy gains for test electrons beyond 6 TeV were found
in this case.Comment: 9 pages, 7 figure
The energy dependence of angular correlations inferred from mean- fluctuation scale dependence in heavy ion collisions at the SPS and RHIC
We present the first study of the energy dependence of angular
correlations inferred from event-wise mean transverse momentum
fluctuations in heavy ion collisions. We compare our large-acceptance
measurements at CM energies $\sqrt{s_{NN}} =$ 19.6, 62.4, 130 and 200 GeV to
SPS measurements at 12.3 and 17.3 GeV. $p_t$ angular correlation structure
suggests that the principal source of $p_t$ correlations and fluctuations is
minijets (minimum-bias parton fragments). We observe a dramatic increase in
correlations and fluctuations from SPS to RHIC energies, increasing linearly
with $\ln \sqrt{s_{NN}}$ from the onset of observable jet-related
fluctuations near 10 GeV.Comment: 10 pages, 4 figure
Measurement of Transverse Single-Spin Asymmetries for Di-Jet Production in Proton-Proton Collisions at GeV
We report the first measurement of the opening angle distribution between
pairs of jets produced in high-energy collisions of transversely polarized
protons. The measurement probes (Sivers) correlations between the transverse
spin orientation of a proton and the transverse momentum directions of its
partons. With both beams polarized, the wide pseudorapidity () coverage for jets permits separation of Sivers functions for the valence
and sea regions. The resulting asymmetries are all consistent with zero and
considerably smaller than Sivers effects observed in semi-inclusive deep
inelastic scattering (SIDIS). We discuss theoretical attempts to reconcile the
new results with the sizable transverse spin effects seen in SIDIS and forward
hadron production in pp collisions.Comment: 6 pages total, 1 Latex file, 3 PS files with figure
Energy and system size dependence of \phi meson production in Cu+Cu and Au+Au collisions
We study the beam-energy and system-size dependence of \phi meson production
(using the hadronic decay mode \phi -- K+K-) by comparing the new results from
Cu+Cu collisions and previously reported Au+Au collisions at \sqrt{s_NN} = 62.4
and 200 GeV measured in the STAR experiment at RHIC. Data presented are from
mid-rapidity (|y|<0.5) for 0.4 < pT < 5 GeV/c. At a given beam energy, the
transverse momentum distributions for \phi mesons are observed to be similar in
yield and shape for Cu+Cu and Au+Au colliding systems with similar average
numbers of participating nucleons. The \phi meson yields in nucleus-nucleus
collisions, normalised by the average number of participating nucleons, are
found to be enhanced relative to those from p+p collisions with a different
trend compared to strange baryons. The enhancement for \phi mesons is observed
to be higher at \sqrt{s_NN} = 200 GeV compared to 62.4 GeV. These observations
for the produced \phi(s\bar{s}) mesons clearly suggest that, at these collision
energies, the source of enhancement of strange hadrons is related to the
formation of a dense partonic medium in high energy nucleus-nucleus collisions
and cannot be alone due to canonical suppression of their production in smaller
systems.Comment: 20 pages and 5 figure
Structure and membrane interactions of the homodimeric antibiotic peptide homotarsinin
Antimicrobial peptides (AMPs) from amphibian skin are valuable template structures to find new treatments against bacterial infections. This work describes for the first time the structure and membrane interactions of a homodimeric AMP. Homotarsinin, which was found in Phyllomedusa tarsius anurans, consists of two identical cystine-linked polypeptide chains each of 24 amino acid residues. The high-resolution structures of the monomeric and dimeric peptides were determined in aqueous buffers. The dimer exhibits a tightly packed coiled coil three-dimensional structure, keeping the hydrophobic residues screened from the aqueous environment. An overall cationic surface of the dimer assures enhanced interactions with negatively charged membranes. An extensive set of biophysical data allowed us to establish structure-function correlations with antimicrobial assays against Gram-positive and Gram-negative bacteria. Although both peptides present considerable antimicrobial activity, the dimer is significantly more effective in both antibacterial and membrane biophysical assays.PMC524437
Estimating the global conservation status of more than 15,000 Amazonian tree species
Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century
System size dependence of associated yields in hadron-triggered jets
We present results on the system size dependence of high transverse momentum
di-hadron correlations at = 200 GeV as measured by STAR at
RHIC. Measurements in d+Au, Cu+Cu and Au+Au collisions reveal similar jet-like
correlation yields at small angular separation (,
) for all systems and centralities. Previous measurements have
shown that the away-side yield is suppressed in heavy-ion collisions. We
present measurements of the away-side suppression as a function of transverse
momentum and centrality in Cu+Cu and Au+Au collisions. The suppression is found
to be similar in Cu+Cu and Au+Au collisions at a similar number of
participants. The results are compared to theoretical calculations based on the
parton quenching model and the modified fragmentation model. The observed
differences between data and theory indicate that the correlated yields
presented here will provide important constraints on medium density profile and
energy loss model parameters.Comment: 12 pages, 5 figure
Longitudinal Double-Spin Asymmetry and Cross Section for Inclusive Jet Production in Polarized Proton Collisions at √s = 200 GeV
We report a measurement of the longitudinal double-spin asymmetry ALL and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at √s=200 GeV. The cross section data cover transverse momenta
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