DELLA proteins as hubs in signaling networks in plants

Las Giberelinas (GAs) intervienen en la regulación de numerosos procesos en el desarrollo a lo largo de la vida de la planta, y lo hacen promoviendo la degradación de las proteínas DELLA (DELLAs) [1], reguladoras negativas de las respuestas a GAs. Las DELLAs son nucleares y carecen de sitios de unión a DNA, sin embargo son capaces de interaccionar con otras proteínas y de esta manera regular la expresión génica [2-6]. Una de las preguntas que se abordaran en este proyecto es el de entender como las GAs son capaces de regular diversos procesos del crecimiento y del desarrollo, nuestra hipótesis se basa en que las proteínas DELLA se encuentran reprimiendo o potenciando la actividad de otras proteínas involucradas en diferentes procesos del desarrollo.Marín De La Rosa, NA. (2014). DELLA proteins as hubs in signaling networks in plants [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/37193TESI

Genome Wide Binding Site Analysis Reveals Transcriptional Coactivation of Cytokinin-Responsive Genes by DELLA Proteins

[EN] The ability of plants to provide a plastic response to environmental cues relies on the connectivity between signaling pathways. DELLA proteins act as hubs that relay environmental information to the multiple transcriptional circuits that control growth and development through physical interaction with transcription factors from different families. We have analyzed the presence of one DELLA protein at the Arabidopsis genome by chromatin immunoprecipitation coupled to large-scale sequencing and we find that it binds at the promoters of multiple genes. Enrichment analysis shows a strong preference for cis elements recognized by specific transcription factor families. In particular, we demonstrate that DELLA proteins are recruited by type-B ARABIDOPSIS RESPONSE REGULATORS (ARR) to the promoters of cytokinin-regulated genes, where they act as transcriptional co-activators. The biological relevance of this mechanism is underpinned by the necessity of simultaneous presence of DELLAs and ARRs to restrict root meristem growth and to promote photomorphogenesis.This work was funded by grants BIO2007-60923 and BIO2010-15071 from the Spanish Ministry of Economy and Innovation (MAB); grant ERC-2011-StG_20101109 from the European Research Council (JUL); grants BB/J/00426X/1 and BB/E022618/1 from the Biotechnology and Biological Sciences Research Council (SGT); the Professorial Research Fellowship award BB/G023972/1 from the Biotechnology and Biological Sciences Research Council (KH and MJB); and grant FP7-311929 from the European Union (RPB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Marín-De La Rosa, NA.; Pfeiffer, A.; Hill, K.; Locascio ., AAM.; Bhalerao, R.; Miskolczi, P.; Grønlund, A.... (2015). Genome Wide Binding Site Analysis Reveals Transcriptional Coactivation of Cytokinin-Responsive Genes by DELLA Proteins. PLoS Genetics. 11(7):1-20. https://doi.org/10.1371/journal.pgen.100533712011

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

Regulación hormonal del crecimiento rítmico en arabidopsis

El reloj circadiano en un mecanismo de regulación interna, que permite a la planta sincronizarse con señales ambientales como la luz y temperatura. Las plantas dependen de la luz solar con esto erl reloj circadiano toma un papel primordial en su organización diaria. El crecimiento es un proceso restringido a cierto periodo del día, la ventana del crecimiento se encuentra al final de la noche. Esto se lleva a cabo por la combinación de la acción del reloj circadiano que reprime el crecimiento durante la noche y la señalización mediada por la luz en donde se reprime el crecimiento en el día. También promueven el crecimiento varias hormonas como auxinas, brasinosteroides y giberelinas (GAs), en el caso de auxinas, se ha reportado que esta acción es mediada por el reloj. Esto indica que las vías hormonales también pueden ser dianas del reloj circadiano en esta regulación. Nosotros estudiamos de qué forma participa la señalización por GAs en el control del crecimiento rítmico. Nuestros resultados muestran que la señalización por GA se lleva a cabo a través de la regulación transcripcional de los receptores de GA; una máxima sensibilidad de Ga se correlaciona con el periodo máximo de crecimiento. Dados los modelos moleculares de la inducción del crecimiento por el reloj y las GAs, este dato adicional en las GAs, este adicional en la regulación proporciona fuerza a este modelo del crecimiento rítmico.Marín De La Rosa, NA. (2010). Regulación hormonal del crecimiento rítmico en arabidopsis. http://hdl.handle.net/10251/14702Archivo delegad

Multi-strange baryon production in pp collisions at √s=7 TeV with ALICE

A measurement of the multi-strange Ξ− and Ω− baryons and their antiparticles by the ALICE experiment at the CERN Large Hadron Collider (LHC) is presented for inelastic proton–proton collisions at a centre-of-mass energy of 7 TeV. The transverse momentum (pT) distributions were studied at mid-rapidity (|y|6.0 GeV/c. We also illustrate the difference between the experimental data and model by comparing the corresponding ratios of (Ω−+Ω¯+)/(Ξ−+Ξ¯+) as a function of transverse mass

Coherent J/ψ photoproduction in ultra-peripheral Pb–Pb collisions at √sNN=2.76 TeV

The ALICE Collaboration has made the first measurement at the LHC of J/ψ photoproduction in ultra-peripheral Pb–Pb collisions at sNN=2.76 TeV. The J/ψ is identified via its dimuon decay in the forward rapidity region with the muon spectrometer for events where the hadronic activity is required to be minimal. The analysis is based on an event sample corresponding to an integrated luminosity of about 55 μb−1. The cross section for coherent J/ψ production in the rapidity interval −3.6<y<−2.6 is measured to be dσJ/ψcoh/dy=1.00±0.18(stat)−0.26+0.24(syst) mb. The result is compared to theoretical models for coherent J/ψ production and found to be in good agreement with those models which include nuclear gluon shadowing

Heavy flavour decay muon production at forward rapidity in proton–proton collisions at √s=7 TeV

The production of muons from heavy flavour decays is measured at forward rapidity in proton–proton collisions at √s=7 TeV collected with the ALICE experiment at the LHC. The analysis is carried out on a data sample corresponding to an integrated luminosity Lint=16.5 nb−1. The transverse momentum and rapidity differential production cross sections of muons from heavy flavour decays are measured in the rapidity range 2.5<y<4, over the transverse momentum range 2<pt<12 GeV/c. The results are compared to predictions based on perturbative QCD calculations

Ds+ meson production at central rapidity in proton–proton collisions at √s=7 TeV

The pT-differential inclusive production cross section of the prompt charm-strange meson Ds+ in the rapidity range |y|<0.5 was measured in proton–proton collisions at s=7 TeV at the LHC using the ALICE detector. The analysis was performed on a data sample of 2.98×108 events collected with a minimum-bias trigger. The corresponding integrated luminosity is Lint=4.8 nb−1. Reconstructing the decay Ds+→ϕπ+, with ϕ→K−K+, and its charge conjugate, about 480 Ds± mesons were counted, after selection cuts, in the transverse momentum range 2<pT<12 GeV/c. The results are compared with predictions from models based on perturbative QCD. The ratios of the cross sections of four D meson species (namely D0, D+, D⁎+ and Ds+) were determined both as a function of pT and integrated over pT after extrapolating to full pT range, together with the strangeness suppression factor in charm fragmentation. The obtained values are found to be compatible within uncertainties with those measured by other experiments in e+e−, ep and pp interactions at various centre-of-mass energies

Suppression of charged particle production at large transverse momentum in central Pb–Pb collisions at √sNN=2.76 TeV

Inclusive transverse momentum spectra of primary charged particles in Pb–Pb collisions at √sNN=2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0–5% and 70–80% of the hadronic Pb–Pb cross section. The measured charged particle spectra in |η|<0.8 and 0.3<pT<20 GeV/c are compared to the expectation in pp collisions at the same sNN, scaled by the number of underlying nucleon–nucleon collisions. The comparison is expressed in terms of the nuclear modification factor RAA. The result indicates only weak medium effects (RAA≈0.7) in peripheral collisions. In central collisions, RAA reaches a minimum of about 0.14 at pT=6–7 GeV/c and increases significantly at larger pT. The measured suppression of high-pT particles is stronger than that observed at lower collision energies, indicating that a very dense medium is formed in central Pb–Pb collisions at the LHC