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Nuclear speckle RNA binding proteins (NSRs) act as regulators of alternative splicing (AS) and auxin-regulated developmental processes such as lateral root formation in Arabidopsis thaliana. These proteins were shown to interact with specific alternatively spliced mRNA targets and at least with one structured lncRNA, named Alternative Splicing Competitor RNA. Here, we used genome-wide analysis of RNAseq to monitor the NSR global role on multiple tiers of gene expression, including RNA processing and AS. NSRs affect AS of 100s of genes as well as the abundance of lncRNAs particularly in response to auxin. Among them, the FPA floral regulator displayed alternative polyadenylation and differential expression of antisense COOLAIR lncRNAs in nsra/b mutants. This may explains the early flowering phenotype observed in nsra and nsra/b mutants. GO enrichment analysis of affected lines revealed a novel link of NSRs with the immune response pathway. A RIP-seq approach on an NSRa fusion protein in mutant background identified that lncRNAs are privileged direct targets of NSRs in addition to specific AS mRNAs. The interplay of lncRNAs and AS mRNAs in NSR-containing complexes may control the crosstalk between auxin and the immune response pathway. Fil: Bazin, Jérémie. Universite Paris-sud Xi; Fil: Romero, Natali. Universite Paris-sud Xi; Fil: Rigo, Richard. Universite Paris-sud Xi; Fil: Charon, Celine. Universite Paris-sud Xi; Fil: Blein, Thomas. Universite Paris-sud Xi; Fil: Ariel, Federico Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Crespi, Martin. Universite Paris-sud Xi

Fil: Tesler, Federico Ariel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

Massive high-throughput sequencing techniques allowed the identification of thousands of noncoding RNAs (ncRNAs) and a plethora of different mRNA processing events occurring in higher organisms. Long ncRNAs can act directly as long transcripts or can be processed into active small si/miRNAs. They can modulate mRNA cleavage, translational repression or the epigenetic landscape of their target genes. Recently, certain long ncRNAs have been shown to play a crucial role in the regulation of alternative splicing in response to several stimuli or during disease. In this review, we focus on recent discoveries linking gene regulation by alternative splicing and its modulation by long and small ncRNAs. Fil: Romero Barrios, Natali. Universite Paris-sud Xi; Fil: Legascue, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Benhamed, Moussa. Universite Paris-sud Xi; Fil: Ariel, Federico Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Crespi, Martin. Universite Paris-sud Xi

Objectives: Heart failure has a great impact on health budget, mainly due to the cost of hospitalizations. Our aim was to describe health resource use and costs of heart failure admissions in three important institutions in Argentina. Methods: Multi-center retrospective cohort study, with descriptive and analytical analysis by subgroups of ejection fraction, blood pressure and renal function at admission. Generalized linear models were used to assess the association of independent variables to main outcomes. Results: We included 301 subjects; age 75.3±11.8 years; 37% women; 57% with depressed ejection fraction; 46% of coronary etiology. Blood pressure at admission was 129.8±29.7 mmHg; renal function 57.9±26.2 ml/min/1.73 m2. Overall mortality was 7%. Average length of stay was 7.82±7.06 days (median 5.69), and was significantly longer in patients with renal impairment (8.9 vs. 8.18; p=0.03) and shorter in those with high initial blood pressure (6.08±4.03; p=0.009). Mean cost per patient was AR$68,861±96,066 (US$=8,071; 1US$=AR$8.532); 71% attributable to hospital stay, 20% to interventional procedures and 6.7% to diagnostic studies. Variables independently associated with higher costs were depressed ejection fraction, presence of valvular disease, and impaired renal function. Conclusions: Resource use and costs associated to hospitalizations for heart failure is high, and the highest proportion is attributable to the costs related to hospital stay. Fil: Augustovski, Federico Ariel. Instituto de Efectividad Clínica y Sanitaria; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Caporale Bec, Joaquín. Instituto de Efectividad Clínica y Sanitaria; Argentina Fil: Fosco, Matías. Fundación Favaloro; Argentina Fil: Alcaraz, Andrea. Instituto de Efectividad Clínica y Sanitaria; Argentina Fil: Diez, Mirta. Instituto Cardiovascular de Buenos Aires; Argentina Fil: Thierer, Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina Fil: Peradejordi Lastras, Margarita Ana. Fundación Favaloro; Argentina Fil: Pichón-Riviere, Andrés. Instituto de Efectividad Clínica y Sanitaria; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Fil: Carlotto, Nicolas. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biologia Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biologia Experimental y Aplicada; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiologia, Biologia Molecular y Celular. Laboratorio de Agrobiotecnologia; Argentina

A singular value decomposition (SVD) analysis was performed jointly on the daily intensity of extreme rainfall (DIER) over Argentina and sea surface temperature (SST) anomalies from 17.5°N–90°S to describe and understand the influence of the large-scale variability of the SSTs on the regional extreme rainfall events for spring summer, autumn and winter. Three main leading modes were identified in agreement with previous works. Mode 1 activity is strongly related to El Nino-Southern Oscillation (ENSO). Warm anomalies in the central-eastern tropical Pacific and western Indian Ocean induce circulation anomalies extended along the South Pacific and the development of a continental-scale circulation gyre in South America promoting moisture convergence, and in turn favouring DIER positive anomalies, in eastern Argentina. The combined influence of SST anomalies in the tropical Atlantic and western tropical Pacific characterizes Mode 2 activity, which induces an anticyclonic (cyclonic) circulation gyre in southeastern South America promoting anomalous moisture convergence (divergence) and thus positive (negative) DIER anomalies in eastern Argentina in spring and fall (summer and winter). Finally, Mode 3 activity is also influenced by SST anomalies in tropical central-eastern Pacific from winter to summer. The associated teleconnections contribute to the development of a cyclonic circulation mainly influencing southeastern South America (SESA) circulation to the north of 30°S from summer to winter, and further south in spring.

Summary Monthly and daily precipitation extremes over La Plata Basin (LPB) are analyzed in the framework of the CLARIS-LPB Project. A review of the studies developed during the project and results of additional research are presented and discussed. Specific aspects of analysis are focused on large-scale versus local processes impacts on the intensity and frequency of precipitation extremes over LPB, and on the assessment of specific wet and dry spell indices and their changed characteristics in future climate scenarios. The analysis is shown for both available observations of precipitation in the region and ad-hoc global and regional models experiments. The Pacific, Indian and Atlantic Oceans can all impact precipitation intensity and frequency over LPB. In particular, considering the Pacific sector, different types of ENSO events (i.e. canonical vs Modoki or East vs Central) have different influences. Moreover, model projections indicate an increase in the frequency of precipitation extremes over LPB during El Nino and La Nina events in future climate. Local forcings can also be important for precipitation extremes. Here, the feedbacks between soil moisture and extreme precipitation in LPB are discussed based on hydric conditions in the region and model sensitivity experiments. Concerning droughts, it was found that they were more frequent in the western than in the eastern sector of LPB during the period of 1962–2008. On the other hand, observations and model experiments agree in that the monthly wet extremes were more frequent than the dry extremes in the northern and southern LPB sectors during the period 1979–2001, with higher frequency in the south.

Fil: Lucero, Leandro Exequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Manavella, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Gras, Diana Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Ariel, Federico Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Gonzalez, Daniel Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina

Background European guidelines recommend the use of ticagrelor versus clopidogrel in patients with ST elevation myocardial infarction (STEMI). This recommendation is based on inconclusive results and subanalyses from clinical trials. Few data are available on the effects of ticagrelor in a real-world population. Methods To compare the effects of ticagrelor and clopidogrel in a real-world STEMI population, we conducted a pre-post case-control study examining all patients with STEMI included in the Cardio-STEMI Sanremo registry between February 2011 and June 2013. Cases and controls were defined according to P2Y12 inhibitors, correcting the bias due to lack of randomization by propensity score analysis. Ticagrelor was introduced in 2012 in both in-hospital and pre-hospital settings independently of this study. Results Of the 416 patients enrolled in the Cardio-STEMI registry, 401 with a definite diagnosis of STEMI were included in this study. One hundred forty-two patients received ticagrelor and 259 received clopidogrel. Regarding clinical presentation and procedural data, those in the ticagrelor group had lower CRUSADE scores (23 [14–36] vs 27 [18–38]; p = 0.015] but a higher proportion of radial access (33% vs 14%; p

The term non-coding RNA (ncRNA) refers to functional RNA molecules that, despite being transcribed from DNA, are not translated into proteins. These molecules can play an important role in the regulation of gene expression in the eukaryotic cell, and they can act either as long ncRNAs or being processed intosmall RNAs, being globally classified by their size, function or genomic origin. In recent years, it has been found that diverse ncRNAs participate directly or indirectly in several epigenetic phenomena controlling different phenotypes within clonal cells, and in the specificity determination of various hysiological processes. Although some of their mechanisms of action have been characterized, much remains to be known to understand the highly complex processes in which most of these molecules are involved. In this chapter we discuss and illustrate examples of different ncRNAs that can interact with the plant epigenomic machinery or intervene in its function, leading to specific epigenetic, transcriptional and physiological states. We explore the link between chromatin compaction, histone modifications, DNA methylation, gene silencing and these molecules, which represent a high proportion of the cellular transcriptome. Fil: Ramirez Prado, Juan. Institute of Plant Sciences Paris-Saclay; Francia. King Abdullah University of Science and Technology; Arabia Saudita Fil: Ariel, Federico Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Benhamed, Moussa. King Abdullah University of Science and Technology; Arabia Saudita. Institute of Plant Sciences Paris-Saclay; Francia Fil: Crespi, Martin. Institute of Plant Sciences Paris-Saclay; Francia

Las enfermedades no transmisibles (ENT) son la principal causa de muerte en las Américas; entre ellas, las enfermedades cardiovasculares (ECV) ocasionan 45% de las defunciones (Hospedales, Barcelo, Luciani y colaboradores 2012). Se calcula que en América Latina y el Caribe (ALC), las defunciones atribuibles a las ECV, en particular la enfermedad coronaria (EC), aumentarán en alrededor de 145%, tanto en los hombres como en las mujeres, entre 1990 y el año 2020. Estas cifras contrastan con un aumento de 28% en las mujeres y de 50% en los hombres durante el mismo periodo en los países desarrollados (Yusuf, Hawken, Ounpuu y colaboradores 2004). Fil: Watkin, David. No especifíca; Fil: Poggio, Rosana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; Argentina Fil: Augustovski, Federico Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; Argentina Fil: Brouwer, Elizabeth. No especifíca; Fil: Pichon Riviere, Andrés. No especifíca; Fil: Rubinstein, Adolfo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; Argentina Fil: Nugent, Rachel. No especifíca

En General: - En el transcurso del período indicado desarrollé tareas de elaboración de presupuestos anuales, supervisión y ejecución de tareas administrativo contables, realización de informes técnico-contables y rendiciones de cuentas de los proyectos mencionados. - Llevé adelante el manejo de la administración de la UNIDAD Pla.Pi.Mu. - LA.SE.I.SI.C. (atención a requerimientos internos de Investigadores y externos de Proveedores). - Ejecuté evaluaciones técnico - económicas de los Proyectos de investigación y desarrollo que la UNIDAD Pla.Pi.Mu. - LA.SE.I.SI.C. realizó para terceros, colaboré con el servicio de relaciones industriales y comerciales de la UNIDAD, igual tarea llevé a cabo en los estudios que se realizan para fijar líneas prioritarias de investigación y desarrollo. Para los Proyectos mencionados arriba: - Estudio del mercado respecto de la disponibilidad de los metales recuperados en pilas agotadas (acero, manganeso y cinc). Valor, volúmenes de importación, usos, etc. - Al igual que en el período anterior sigo estudiando la disponibilidad de metales recuperados (acero, magnesio y cinc), dentro del mercado de nuestro país, su valor, volúmenes de importación, usos, etc., para poder dar un asesoramiento a las entidades que instalen las plantas. Esta actividad ha adquirido relevancia y se ha avanzado en la instalación de las mencionadas plantas de tratamiento de Pilas y en las de tratamiento de residuos domiciliarios urbanos en la Provincia de Buenos Aires. - Conformé planillas para el seguimiento de los procesos. - Procesé los datos obtenidos mediante planillas de Excel para calcular la distribución del tamaño de partículas. - Confeccioné gráficos para las curvas de equilibrio para los proyectos. - Me encargué de la compra de los insumos necesarios para los proyectos.

Legume plants are able to interact with Rhizobium bacteria. This interaction leads to the development of a specialized organ called root nodule. Inside the symbiotic nodule cells, rhizobia are capable to fix atmospheric nitrogen and convert it to ammonia, which is a usable nitrogen source for the plant. In the legume Medicago truncatula the symbiotic cells produce high amounts of Nodule-Specific Cysteine-Rich (NCR) peptides which induce differentiation of the rhizobia into enlarged, polyploid and non-cultivable bacterial cells. NCRs are similar to innate immunity antimicrobial peptides. The NCR gene family is extremely large in Medicago with about 600 genes. The expression analysis of 334 NCR genes in 267 different experimental conditions using the Medicago truncatula Gene Expression Atlas (MtGEA) revealed that all the NCR genes except five are exclusively expressed in nodules. No NCR expression is induced in any other plant organ or in response to biotic, abiotic stress tested or to Nod factors. The NCR genes are activated in consecutive waves during nodule organogenesis, which correlated with a specific spatial localization of their transcripts from the apical to the proximal nodule zones. Moreover, we showed that NCRs are not induced during nodule senescence. According to their Shannon entropy, a metric for tissue specificity, NCR genes are among the most specifically and highest expressed genes in M. truncatula. Thus, NCR gene expression is subject to an extreme tight regulation since they are only activated during nodule organogenesis in the polyploid symbiotic cells. This analysis suggested the involvement of epigenetic regulation of the NCR genes. The formation of the symbiotic cells is driven by endoreduplication and is associated with transcriptional reprogramming. Using sorted nodule nuclei according to their DNA content, we demonstrated that the transcriptional waves correlate with growing ploidy levels and investigated how the epigenome changes during endoreduplication cycles. We studied genome-wide DNA methylation and chromatin accessibility as well as the presence of repressive H3K27me3 and activating H3K9ac histone tail modifications on selected genes. Differential DNA methylation was found only in a small subset of symbiotic nodule-specific genes, including over half of the NCR genes, while in most genes DNA methylation was unaffected by the ploidy levels and was independent of the genes’ active or repressed state. On the other hand, expression of these genes correlated with ploidy-dependent opening of the chromatin and in a subset of tested genes with reduced H3K27me3 levels combined with enhanced H3K9ac levels. Our results suggest that endoreduplication-dependent epigenetic changes contribute to transcriptional reprogramming in differentiation of symbiotic cells.

Circular RNAs can regulate the alternative splicing profile of their parental genes by physically interacting with the DNA to form RNA:DNA hybrids. Fil: Ariel, Federico Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Crespi, Martin. Université Paris Sud; Francia

As the most recent evidence of eukaryotic cell complexity, genome architecturehas astounded the scientific community and prompted a variety of technical andcognitive challenges. Several technologies have emerged and evidenced theintegration of chromatin packaging and topology, epigenetic processes, andtranscription for the pertinent regulation of gene expression. In the presentaddendum we present and discuss some of our recent research, directedtowards the holistic comprehension of the processes by which plants respond toenvironmental and developmental stimuli. We propose that the study of genometopology and genomic interactions is essential for the understanding of themolecular mechanisms behind a phenotype. Even though our knowledge andunderstanding of genome architecture and hierarchy has improved substantiallyin the last few years -in Arabidopsis and other eukaryotes -, there is still a long way ahead in this relatively new field of study. For this, it is necessary to take advantage of the high resolution of the emerging available techniques, and perform integrative approaches with which it will be possible to depict the role of chromatin architecture in the regulation of transcription and ultimately, physiological processes. Fil: Ramirez Prado, Juan Sebatian. King Abdullah University of Science and Technology; Arabia Saudita Fil: Rodriguez Granados, Natalia Yaneth. Centre National de la Recherche Scientifique; Francia. Université Paris Sud; Francia Fil: Ariel, Federico Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Raynaud, Cecile. Centre National de la Recherche Scientifique; Francia. Université Paris Sud; Francia Fil: Benhamed, Moussa. Centre National de la Recherche Scientifique; Francia. Université Paris Sud; Francia. King Abdullah University of Science and Technology; Arabia Saudita

Precise expression patterns of genes in time and space are essential for proper development of multicellular organisms. Dynamic chromatin conformation and spatial organization of the genome constitute a major step in this regulation to modulate developmental outputs. Polycomb repressive complexes (PRCs) mediate stable or flexible gene repression in response to internal and environmental cues. In Arabidopsis thaliana, LHP1 co-localizes with H3K27me3 epigenetic marks throughout the genome and interacts with PRC1 and PRC2 members as well as with a long noncoding RNA. Here, we show that LHP1 is responsible for the spreading of H3K27me3 towards the 3' end of the gene body. We also identified a subset of LHP1-activated genes and demonstrated that LHP1 shapes local chromatin topology in order to control transcriptional co-regulation. Our work reveals a general role of LHP1 from local to higher conformation levels of chromatin configuration to determine its accessibility to define gene expression patterns. Fil: Veluchamy, Alaguraj. King Abdullah University of Science and Technology; Arabia Saudita Fil: Jégu, Teddy. Centre National de la Recherche Scientifique; Francia. Université Paris Sud; Francia Fil: Ariel, Federico Damian. Université Paris Sud; Francia. Centre National de la Recherche Scientifique; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Latrasse, David. Centre National de la Recherche Scientifique; Francia. Université Paris Sud; Francia. King Abdullah University of Science and Technology; Arabia Saudita Fil: Mariappan, Kiruthiga Gayathri. King Abdullah University of Science and Technology; Arabia Saudita Fil: Kim, Soon Kap. King Abdullah University of Science and Technology; Arabia Saudita Fil: Crespi, Martín. Centre National de la Recherche Scientifique; Francia. Université Paris Sud; Francia Fil: Hirt, Heribert. King Abdullah University of Science and Technology; Arabia Saudita Fil: Bergounioux, Catherine. Centre National de la Recherche Scientifique; Francia. Université Paris Sud; Francia Fil: Raynaud, Cécile. Centre National de la Recherche Scientifique; Francia. Université Paris Sud; Francia Fil: Benhamed, Moussa. Université Paris Sud; Francia. Centre National de la Recherche Scientifique; Francia

International audience; RNA quality control (RQC) eliminates aberrant RNAs based on their atypical structure, whereas posttranscriptional gene silencing (PTGS) eliminates both aberrant and functional RNAs through the sequence-specific action of short interfering RNAs (siRNAs). The Arabidopsis thaliana mutant smd1b was identified in a genetic screen for PTGS deficiency, revealing the involvement of SmD1, a component of the Smith (Sm) complex, in PTGS. The smd1a and smd1b single mutants are viable, but the smd1a smd1b double mutant is embryo-lethal, indicating that SmD1 function is essential. SmD1b resides in nucleoli and nucleoplasmic speckles, colocalizing with the splicing-related factor SR34. Consistent with this, the smd1b mutant exhibits intron retention at certain endogenous mRNAs. SmD1 binds to RNAs transcribed from silenced transgenes but not nonsilenced ones, indicating a direct role in PTGS. Yet, mutations in the RQC factors UPFRAMESHIFT3, EXORIBONUCLEASE2 (XRN2), XRN3, and XRN4 restore PTGS in smd1b, indicating that SmD1 is not essential for but rather facilitates PTGS. Moreover, the smd1b mtr4 double mutant is embryo-lethal, suggesting that SmD1 is essential for mRNA TRANSPORT REGULATOR4-dependent RQC. These results indicate that SmD1 interplays with splicing, RQC, and PTGS. We propose that SmD1 facilitates PTGS by protecting transgene-derived aberrant RNAs from degradation by RQC in the nucleus, allowing sufficient amounts to enter cytoplasmic siRNA bodies to activate PTGS.

A singular value decomposition (SVD) analysis was performed jointly on the daily intensity of extreme rainfall (DIER) over Argentina and sea surface temperature (SST) anomalies from 17.5∘N?90∘S to describe and understand the influence of the large-scale variability of the SSTs on the regional extreme rainfall events for spring summer, autumn and winter. Three main leading modes were identified in agreement with previous works. Mode 1 activity is strongly related to El Niño-Southern Oscillation (ENSO). Warm anomalies in the central-eastern tropical Pacific and western Indian Ocean induce circulation anomalies extended along the South Pacific and the development of a continental-scale circulation gyre in South America promoting moisture convergence, and in turn favouring DIER positive anomalies, in eastern Argentina. The combined influence of SST anomalies in the tropical Atlantic and western tropical Pacific characterizes Mode 2 activity, which induces an anticyclonic (cyclonic) circulation gyre in southeastern South America promoting anomalous moisture convergence (divergence) and thus positive (negative) DIER anomalies in eastern Argentina in spring and fall (summer and winter). Finally, Mode 3 activity is also influenced by SST anomalies in tropical central-eastern Pacific from winter to summer. The associated teleconnections contribute to the development of a cyclonic circulationmainly influencing southeastern SouthAmerica (SESA) circulation to the north of 30∘S from summer to winter, and further south in spring. Fil: Robledo, Federico Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; Argentina Fil: Vera, Carolina Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; Argentina Fil: Penalba, Olga Clorinda. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina

Photodynamic therapy (PDT) is based on the cytotoxicity of photosensitizers in the presence of light. Increased selectivity and effectivity of the treatment is expected if a specific uptake of the photosensitizers into the target cells, often tumor cells, can be achieved. An attractive transporter for that purpose is the folic acid receptor α (FRα), which is overexpressed on the surface of many tumor cells and mediates an endocytotic uptake. Here, we describe the synthesis and photobiological characterization of polar β‐carboline derivatives as photosensitizers covalently linked to folate‐tagged albumin as the carrier system. The particles were taken up by KB (human carcinoma) cells within, Facultad de Ciencias Exactas

Summary Legume crops related to the model plant Medicago truncatula can adapt their root architecture to environmental conditions, both by branching and by establishing a symbiosis with rhizobial bacteria to form nitrogen-fixing nodules. Soil salinity is a major abiotic stress affecting plant yield and root growth. Previous transcriptomic analyses identified several transcription factors linked to the M. truncatula response to salt stress in roots, including NAC (NAM/ATAF/CUC)-encoding genes. Over-expression of one of these transcription factors, MtNAC969, induced formation of a shorter and less-branched root system, whereas RNAi-mediated MtNAC969 inactivation promoted lateral root formation. The altered root system of over-expressing plants was able to maintain its growth under high salinity, and roots in which MtNAC969 was down-regulated showed improved growth under salt stress. Accordingly, expression of salt stress markers was decreased or induced in MtNAC969 over-expressing or RNAi roots, respectively, suggesting a repressive function for this transcription factor in the salt-stress response. Expression of MtNAC969 in central symbiotic nodule tissues was induced by nitrate treatment, and antagonistically affected by salt in roots and nodules, similarly to senescence markers. MtNAC969 RNAi nodules accumulated amyloplasts in the nitrogen-fixing zone, and were prematurely senescent. Therefore, the MtNAC969 transcription factor, which is differentially affected by environmental cues in root and nodules, participates in several pathways controlling adaptation of the M. truncatula root system to the environment.

Phytohormonal interactions are essential to regulate plant organogenesis. In response to the presence of signals from symbiotic bacteria, the Nod factors, legume roots generate a new organ: the nitrogen-fixing nodule. Analysis of mutants in the Medicago truncatula CRE1 cytokinin receptor and of the MtRR4 cytokinin primary response gene expression pattern revealed that cytokinin acts in initial cortical cell divisions and later in the transition between meristematic and differentiation zones of the mature nodule. MtCRE1 signaling is required for activation of the downstream nodulation-related transcription factors MtERN1, MtNSP2 and MtNIN, as well as to regulate expression and accumulation of PIN auxin efflux carriers. Whereas the MtCRE1 pathway is required to allow the inhibition of polar auxin transport in response to rhizobia, nodulation is still negatively regulated by the MtEIN2/SICKLE-dependent ethylene pathway in cre1 mutants. Hence, MtCRE1 signaling acts as a regulatory knob, integrating positive plant and bacterial cues to control legume nodule organogenesis.

Despite the independent evolution of multicellularity in plants and animals, the basic organization of their stem cell niches is remarkably similar. Here, we report the genome-wide regulatory potential of WUSCHEL, the key transcription factor for stem cell maintenance in the shoot apical meristem of the reference plant Arabidopsis thaliana. WUSCHEL acts by directly binding to at least two distinct DNA motifs in more than 100 target promoters and preferentially affects the expression of genes with roles in hormone signaling, metabolism, and development. Striking examples are the direct transcriptional repression of CLAVATA1, which is part of a negative feedback regulation of WUSCHEL, and the immediate regulation of transcriptional repressors of the TOPLESS family, which are involved in auxin signaling. Our results shed light on the complex transcriptional programs required for the maintenance of a dynamic and essential stem cell niche. Fil: Busch, Wolfang. Max Planck Institute For Developmental Biology; Alemania. University of Duke; Estados Unidos Fil: Miotk, Andrej. University of Heidelberg; Alemania Fil: Ariel, Federico Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Zhao, Zhong. University of Heidelberg; Alemania Fil: Forner, Joachim. University of Heidelberg; Alemania Fil: Daum, Gabor. University of Heidelberg; Alemania Fil: Suzaki, Takuya. University of Heidelberg; Alemania Fil: Schuster, Christoph. University of Heidelberg; Alemania Fil: Schultheiss, Sebastian J.. Max Planck Institute For Developmental Biology; Alemania Fil: Leibfried, Andrea. Max Planck Institute For Developmental Biology; Alemania Fil: Haubeiß, Silke. Max Planck Institute For Developmental Biology; Alemania Fil: Ha, Nati. University of Heidelberg; Alemania Fil: Chan, Raquel Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Lohmann, Jan U.. Max Planck Institute For Developmental Biology; Alemania. University of Heidelberg; Alemania

OBJECTIVES: To understand the disease burden of pneumococcal disease (PD), a major cause of childhood morbidity and mortality in Argentina, and to draw a baseline against which the need for and effectiveness of vaccination with pneumococcal conjugate vaccines might be measured. METHODS: A Markov model was constructed to estimate incidence and mortality rates of PD-meningitis (MEN), bacteremia/septicemia (BACT), pneumonia (PNEU), acute otitis media (AOM)-among a hypothetical, birth cohort of 750 000 Argentine infants born in 2006-2015. A systematic review of the literature was performed to select and incorporate input parameters. Life years and costs in 2006 US$ were expressed as both undiscounted and discounted. RESULTS: The number of PD episodes estimated to occur over a 10-year period in the hypothetical birth cohort were: MEN, 225; BACT, 2 841; PNEU, 2 628; and AOM, 2 066 719. Chronic sequelae of MEN could be expected to cause neurological damage in 43 children and severe hearing issues in 28. Results indicate that there would be 78 PD-related deaths in the cohort (29% due to MEN; 54%, BACT; and 17%, PNEU). The undiscounted life-expectancy for individuals in the birth cohort was estimated to be 72.4 years (29.0 years discounted). Mean, undiscounted, lifetime costs attributed to PD for each child of the cohort totaled US$ 167 (US$ 151 discounted), imposing a total, cohort cost-burden of more than US$ 126 million (US$ 113 million discounted). CONCLUSIONS: The study shows that PD imposes a significant health and economic burden on the Argentine population. This information is essential for assessing the potential health and economic impact of introducing pneumococcal conjugate vaccine into the national immunization schedule.OBJETIVOS: Analizar la carga que provoca la enfermedad neumocócica (EN), una importante causa de morbimortalidad infantil en Argentina y establecer una línea de base a partir de la cual se pueda medir la necesidad y la eficacia del uso de vacunas antineumocócicas conjugadas. MÉTODOS: Se elaboró un modelo de Markov para estimar las tasas de incidencia y mortalidad por meningitis (MEN), bacteremia/septicemia (BACT), neumonía (PNEU) y otitis media aguda (AOM) asociadas con la EN, en una cohorte hipotética de 750 000 niños nacidos en Argentina entre 2006 y 2015. Se realizó una revisión sistemática para seleccionar los parámetros de entrada y utilizarlos en el modelo. Los resultados se expresaron en años de vida y costos en dólares estadounidenses (US$), con descuento y sin descuento. RESULTADOS: Los episodios de EN que se estima ocurrirían en un período de 10 años en la cohorte hipotética serían 225 MEN, 2 841 BACT, 2 628 PNEU y 2 066 719 AOM. Las secuelas crónicas de las MEN podrían causar daños neurológicos en 43 niños y trastornos auditivos graves en 28. Estos resultados indican que en esta cohorte habría 78 muertes asociadas con la EN (29% por MEN, 54% por BACT y 17% por PNEU). La esperanza de vida sin descuento estimada para los niños de la cohorte fue de 72,4 años (con descuento de 29,9 años). Los costos promedio sin descuento atribuidos a la EN por cada niño de la cohorte durante toda la vida fueron de US$ 167 (con descuento de US$ 151), lo que provocaría un costo total para la cohorte de más de US$ 126 millones (con descuento de US$ 113 millones). CONCLUSIONES: Estos resultados demuestran que la EN impone una carga sanitaria y económica significativa a la población argentina. Esta información es esencial para evaluar el posible impacto sanitario y económico de la introducción de la vacuna conjugada antineumocócica en el programa nacional de vacunación.

We analyzed trends, interdecadal variability, and the quantification of the changes in the frequency of daily rainfall for two thresholds: 0.1 mm and percentile 75th, using high quality daily series from 52 stations in the La Plata Basin (LPB). We observed increases in the annual frequencies in spatially coherent areas. This coherence was more marked in austral summer, autumn, and spring, during which the greatest increases occurred in southern Brazil, especially during extreme events. In winter, the low and middle basins of the Río Uruguay and Río Paraná showed negative trends, some of which were significant. Interdecadal variability is well defined in the region with more pronounced positive jumps west of the basin between 1950 and 2000. This variability was particularly more marked during periods of extreme rainfall in summer, autumn, and spring, unlike in winter when extreme daily rainfall in the lower Rio Paraná basin decreased by up to 60%. The changes in the past century during extreme rainfall produced modifications in the annual rainfall cycle. The annual cycle of both indices was broader during the last period which is mainly explained by the strong decreases in winter. Fil: Penalba, Olga Clorinda. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Robledo, Federico Ariel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

HAHB4 is a sunflower gene encoding a homeodomain–leucine zipper (HD-Zip) transcription factor. It was previously demonstrated that this gene is regulated at the transcriptional level by several abiotic factors and hormones. A previous analysis in the PLACE database revealed the presence of four putative ABREs. In this work these four elements and also one W-box and two root-specific expression elements were characterized as functional. Site-directed mutagenesis on the promoter, stable transformation of Arabidopis plants as well as transient transformation of sunflower leaves, were performed. The analysis of the transformants was carried out by histochemistry and real time RT-PCR. The results indicate that just one ABRE out of the four is responsible for ABA, NaCl and drought regulation. However, NaCl induction occurs also by an additional ABA-independent way involving another two overlapped ABREs. On the other hand, it was determined that the W-box located 5′ upstream is responsive to ethylene and only two root-specific expression elements, among the several detected, are functional but redundant. Conservation of molecular mechanisms between sunflower and Arabidopsis is strongly supported by this experimental work.

HAHB4 belongs to the sunflower subfamily I of HD-Zip proteins and is involved in drought-tolerance response and ethylene-mediated senescence. Cross-talk between these two processes through this transcription factor was recently described. In this study it is shown that the expression of HAHB4 is induced in darkness and quickly disappears when plants are exposed to light. This regulation of HAHB4 was confirmed at the transcriptional level through the use of transgenic Arabidopsis plants bearing constructs in which different segments of the HAHB4 promoter were fused with the reporter gene GUS. Together with electrophoretic mobility shift assays performed with sunflower nuclear proteins, these experiments allowed a cis-acting element involved in this response to be located. Transient overexpression of the HAHB4 cDNA in sunflower leaf discs and HAHB4 knockdown by iRNA were performed, demonstrating the participation of this transcription factor in the transcriptional down-regulation of a large group of photosynthesis-related genes. In accordance with the reduction in the transcripts encoding chlorophyll a/b-binding proteins, the content of these pigments is diminished in Arabidopsis HAHB4-expressing transgenic plants. Thus, it appears that HAHB4 may participate with other factors in the intricate regulation mechanism of the photosynthetic machinery in darkness.

The HD-Zip family of transcription factors is unique to the plant kingdom. These proteins exhibit the singular combination of a homeodomain with a leucine zipper acting as a dimerization motif. They can be classified into four subfamilies, according to a set of distinctive features that include DNA-binding specificities, gene structures, additional common motifs and physiological functions. Some HD-Zip proteins participate in organ and vascular development or meristem maintenance. Others mediate the action of hormones or are involved in responses to environmental conditions. Here, we review recent data for this family of transcription factors from a wide variety of plant species to unravel their crucial role in plant development. Fil: Ariel, Federico Damian. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Manavella, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Dezar, Carlos Alberto Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Agrobiotecnología de Rosario; Argentina Fil: Chan, Raquel Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina

International audience; Chromatin architecture determines transcriptional accessibility to DNA and consequently gene expression levels in response to developmental and environmental stimuli. Recently, chromatin remodelers such as SWI/SNF complexes have been recognized as key regulators of chromatin architecture. To gain insight into the function of these complexes during root development, we have analyzed Arabidopsis knock-down lines for one sub-unit of SWI/SNF complexes: BAF60. Here, we show that BAF60 is a positive regulator of root development and cell cycle progression in the root meristem via its ability to down-regulate cytokinin production. By opposing both the deposition of active histone marks and the formation of a chromatin regulatory loop, BAF60 negatively regulates two crucial target genes for cytokinin biosynthesis (IPT3 and IPT7) and one cell cycle inhibitor (KRP7). Our results demonstrate that SWI/SNF complexes containing BAF60 are key factors governing the equilibrium between formation and dissociation of a chromatin loop controlling phytohormone production and cell cycle progression.

The endosymbiotic association between legumes and rhizobia leads to the formation of root nodules in which differentiated bacteria convert atmospheric nitrogen into a form that can be assimilated by the host plant. Successful root infection by rhizobia and nodule organogenesis require the activation of symbiotic genes that are controlled by a set of early transcription factors (TFs). MtNF-YA1 and MtNF-YA2 are two TFs playing partially redundant functions during several steps of the symbiotic interaction between Medicago truncatula and Sinorhizobium meliloti. NF-Y proteins are part of a transcriptional complex composed of three proteins (NF-YA, NF-YB and NF-YC) which bind DNA at CCAAT-boxes, a motif present in most eukaryotic promoters. In plants, each subunit is encoded by small gene families, potentially leading to a multitude of heterotrimeric NF-Y complexes. Here, using yeast two hybrid screenings, we identified the MtNF-YB and MtNF-YC subunits that interact with MtNF-YA1 and A2. Further, we confirmed, both in yeast and in planta, the formation of trimeric NF-Y complexes and showed that these complexes are functional during nodulation using reverse genetic approaches and ChIP-PCR. Finally, as orthologs of the characterized NF-Y subunits also control nodulation in other legumes, we showed in common bean that similar NF-Y trimers could form in planta. Our results suggest that we have identified a group of evolutionary conserved NF-Y proteins that interact to control nodulation in leguminous plants. Fil: Baudin, Maël. Centre National de la Recherche Scientifique; Francia. Centre de Recherche de Nantes. Institut National de la Recherche Agronomique; Francia Fil: Laloum, Tom. Centre National de la Recherche Scientifique; Francia. Centre de Recherche de Nantes. Institut National de la Recherche Agronomique; Francia Fil: Lepage, Agnes. Centre National de la Recherche Scientifique; Francia. Centre de Recherche de Nantes. Institut National de la Recherche Agronomique; Francia Fil: Rípodas, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentina Fil: Ariel, Federico Damian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Centre D'etudes de Saclay; Francia Fil: Frances, Lisa. Centre National de la Recherche Scientifique; Francia. Centre de Recherche de Nantes. Institut National de la Recherche Agronomique; Francia Fil: Crespi, Martin. Centre D'etudes de Saclay; Francia Fil: Gamas, Pascal. Centre National de la Recherche Scientifique; Francia Fil: Blanco, Flavio Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentina Fil: Zanetti, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentina Fil: de Carvalho-Niebel, Fernanda. Centre National de la Recherche Scientifique; Francia. Centre de Recherche de Nantes. Institut National de la Recherche Agronomique; Francia Fil: Niebel, Andreas. Centre National de la Recherche Scientifique; Francia. Centre de Recherche de Nantes. Institut National de la Recherche Agronomique; Francia

International audience; Noncoding RNAs have emerged as major components of the eukaryotic transcriptome. Genome-wide analyses revealed the existence of thousands of long noncoding RNAs (IncRNAs) in several plant species. Plant IncRNAs are transcribed by the plant-specific RNA polymerases Pol IV and Pol V, leading to transcriptional gene silencing, as well as by Pol II. They are involved in a wide range of regulatory mechanisms impacting on gene expression, including chromatin remodeling, modulation of alternative splicing, fine-tuning of miRNA activity, and the control of mRNA translation or accumulation. Recently, dual noncoding transcription by alternative RNA polymerases was implicated in epigenetic and chromatin conformation dynamics. This review integrates the current knowledge on the regulatory mechanisms acting through plant noncoding transcription.

In the context of profound economic growth that has been taking place in Latin American countries, the extent of innovation in high technology sectors such as Knowledge Intensive Business Services (KIBS), is considered fundamental to build a virtuous developing path. In this sense, successful innovation in business depends on the development and integration of new knowledge in the innovation process. This paper analyzes the existence of complementarity between internal and external sources of knowledge for innovation activities in firms from the software industry of Argentina, taking account of the limited treatment of these matters in studies of innovation of these sectors in emerging economies. The theoretical framework is grounded on the Make and Buy literature, innovation studies and KIBS literature; and the econometric tools involves a group of estimates of the role of innovation (Ordered Probit, Tobit, OLS and Probit). The results allow us to state the existence of complementary relations between internal and external knowledge sources, regardless the regression model considered, which underline the robustness of the quantitative exercise. http://revistas.unc.edu.ar/index.php/pid/article/view/11506 publishedVersion Fil: Morero, Hernán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; Argentina. Fil: Ortiz, Pablo Arnaldo. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina. Fil: Wyss, Federico Ariel. Universidad Nacional de Córdoba. Facultad de Ciencias Económica; Argentina. Organización Industrial

International audience; During endosymbiotic interactions between legume plants and nitrogen-fixing rhizobia, successful root infection by bacteria and nodule organogenesis requires the perception and transduction of bacterial lipo-chitooligosaccharidic signal called Nod factor (NF). NF perception in legume roots leads to the activation of an early signaling pathway and of a set of symbiotic genes which is controlled by specific early transcription factors (TFs) including CYCLOPS/IPD3, NSP1, NSP2, ERN1 and NIN. In this study, we bring convincing evidence that the Medicago truncatula CCAAT-box-binding NF-YA1 TF, previously associated with later stages of rhizobial infection and nodule meristem formation is, together with its closest homolog NF-YA2, also an essential positive regulator of the NF-signaling pathway. Here we show that NF-YA1 and NF-YA2 are both expressed in epidermal cells responding to NFs and their knock-down by reverse genetic approaches severely affects the NF-induced expression of symbiotic genes and rhizobial infection. Further over-expression, transactivation and ChIP-PCR approaches indicate that NF-YA1 and NF-YA2 function, at least in part, via the direct activation of ERN1. We thus propose a model in which NF-YA1 and NF-YA2 appear as early symbiotic regulators acting downstream of DMI3 and NIN and possibly within the same regulatory complexes as NSP1/2 to directly activate the expression of ERN1.

SWI/SNF complexes mediate ATP-dependent chromatin remodeling to regulate gene expression. Many components of these complexes are evolutionarily conserved, and several subunits of Arabidopsis thaliana SWI/SNF complexes are involved in the control of flowering, a process that depends on the floral repressor FLOWERING LOCUS C (FLC). BAF60 is a SWI/SNF subunit, and in this work, we show that BAF60, via a direct targeting of the floral repressor FLC, induces a change at the high-order chromatin level and represses the photoperiod flowering pathway in Arabidopsis. BAF60 accumulates in the nucleus and controls the formation of the FLC gene loop by modulation of histone density, composition, and posttranslational modification. Physiological analysis of BAF60 RNA interference mutant lines allowed us to propose that this chromatin-remodeling protein creates a repressive chromatin configuration at the FLC locus.

The eukaryotic epigenome is shaped by the genome topology in three-dimensional space. Dynamic reversible variations in this epigenome structure directly influence the transcriptional responses to developmental cues. Here, we show that the Arabidopsis long intergenic noncoding RNA (lincRNA) APOLO is transcribed by RNA polymerases II and V in response to auxin, a phytohormone controlling numerous facets of plant development. This dual APOLO transcription regulates the formation of a chromatin loop encompassing the promoter of its neighboring gene PID, a key regulator of polar auxin transport. Altering APOLO expression affects chromatin loop formation, whereas RNA-dependent DNA methylation, active DNA demethylation, and Polycomb complexes control loop dynamics. This dynamic chromatin topology determines PID expression patterns. Hence, the dual transcription of a lincRNA influences local chromatin topology and directs dynamic auxin-controlled developmental outputs on neighboring genes. This mechanism likely underscores the adaptive success of plants in diverse environments and may be widespread in eukaryotes.

International audience; Alternative splicing (AS) of pre-mRNA represents a major mechanism underlying increased transcriptome and proteome complexity. Here, we show that the nuclear speckle RNA-binding protein (NSR) and the AS competitor long noncoding RNA (or ASCO-IncRNA) constitute an AS regulatory module. AtNSR-GFP translational fusions are expressed in primary and lateral root (LR) meristems. Double Atnsr mutants and ASCO overexpressors exhibit an altered ability to form LRs after auxin treatment. Interestingly, auxin induces a major change in AS patterns of many genes, a response largely dependent on NSRs. RNA immunoprecipitation assays demonstrate that AtNSRs interact not only with their alternatively spliced mRNA targets but also with the ASCO-RNA in vivo. The ASCO-RNA displaces an AS target from an NSR-containing complex in vitro. Expression of ASCO-RNA in Arabidopsis affects the splicing patterns of several NSR-regulated mRNA targets. Hence, IncRNA can hijack nuclear AS regulators to modulate AS patterns during development.

Proyectos de investigación en los cuales colabora: a) Proyecto de obtención de fertilizantes a base de azufre. Proyecto Repsol-YPF. b) Proyecto de obtención de fertilizantes a base de yeso. Pruebas con diferentes aglutinantes.Proyecto Repsol-YPF. c) Proyecto de tratamiento de aguas arsenicales. d) Proyecto de preparación de diferentes catalizadores de óxido de manganeso, cerio y cobre para la eliminación de fenoles en agua. e) Reciclado de Pilas Alcalinas.

Cytokinin regulates many aspects of plant development, and in legume crops, this phytohormone is necessary and sufficient for symbiotic nodule organogenesis, allowing them to fix atmospheric nitrogen. To identify direct links between cytokinins and nodule organogenesis, we determined a consensus sequence bound in vitro by a transcription factor (TF) acting in cytokinin signaling, the nodule-enhanced Medicago truncatula Mt RR1 response regulator (RR). Among genes rapidly regulated by cytokinins and containing this so-called RR binding site (RRBS) in their promoters, we found the nodulation-related Type-A RR Mt RR4 and the Nodulation Signaling Pathway 2 (NSP2) TF. Site-directed mutagenesis revealed that RRBS cis-elements in the RR4 and NSP2 promoters are essential for expression during nodule development and for cytokinin induction. Furthermore, a microRNA targeting NSP2 (miR171 h) is also rapidly induced by cytokinins and then shows an expression pattern anticorrelated with NSP2. Other primary targets regulated by cytokinins depending on the Cytokinin Response1 (CRE1) receptor were a cytokinin oxidase/dehydrogenase (CKX1) and a basic Helix-Loop-Helix TF (bHLH476). RNA interference constructs as well as insertion of a Tnt1 retrotransposon in the bHLH gene led to reduced nodulation. Hence, we identified two TFs, NSP2 and bHLH476, as direct cytokinin targets acting at the convergence of phytohormonal and symbiotic cues.

Esta tesis presenta un estudio de la variabilidad espacio-temporal de laintensidad diaria de precipitación que excede el percentil 75 (DIER75). Esteíndice permitió evaluar la frecuencia y la intensidad de los extremos diarios deprecipitación, explicando el 70% de los acumulados mensuales de lluvia. En elperiodo 1962-2005, la región subtropical de Argentina muestra una disminuciónen el DIER75, en cambio en el centro del país, se registran incrementos en losprimeros meses del año. Junio, es el único mes que presenta una señalsignificativa (disminución) con coherencia espacial, en el centro de Argentina. Asimismo, la región subtropical presenta variabilidades de mayor frecuencia (2años) que las zonas del centro-este de Argentina (de 3 a 8 años), y hacia eloeste, se evidencian ciclos de variabilidad de entre 10 y 14 años. La tesis avanza en el conocimiento sobre la relación entre la anomalía detemperatura superficial del mar (TSM) de los océanos tropicales y subtropicalesy la intensidad de precipitación diaria extrema en la Argentina, con el fin deencontrar las regiones fuentes en los océanos y describir los mecanismosdinámicos asociados a escala planetaria y regional. Se realizó un análisis dedescomposición en valores singulares y se identificó que la influencia del Pacífico, ligada al ENOS y Niño Modoki, aquella del Índico, relacionado al IOD, yaquella del Atlántico, asociada al AMO y el TSA, se combinan en los tresprimeros modos que resultan del análisis de SVD. Aunque la relación de cadauna de las regiones oceánicas identificadas con el DIER75 no es la misma. Enespecial se encontró que la influencia de las regiones oceánicas tropicales sobrelos extremos de precipitación diaria en Argentina, se asocia con diferentestrenes de ondas de Rossby que emanan del Pacífico central y oeste e Índicoeste en dirección a Sudamérica, que promueven la convergencia o divergenciade humedad en el Sudeste de Sudamérica. Se realizó un trabajo exploratorio con el fin de evaluar cómo la señalglobal de calentamiento de las TSM repercute en la covariabilidad observadaentre las anomalías de TSM y del DIER75 en Argentina. Se encontró que estecalentamiento debilita la influencia de la TSM en el Pacífico central asociadas al ENOS, mientras que la asociación se intensifica con los océanos el Indico y el Atlántico tropical. This thesis presents a study of the spatiotemporal variability of extreme dailyrainfall in Argentina using a monthly index of daily precipitation intensity based onthe 75th percentile (DIER75). The index allowed the evaluation of frequency andintensity of extreme daily rainfall, which accounts for 70% of the monthlyaccumulated rainfall. In the period 1962-2005, the subtropical region of Argentinashows a decrease in DIER75, while there are increases in the Midwest during thesummer months. On the other hand, June is the only month that shows asignificant decrease with large spatial coherence in central Argentina. Also, thesubtropical region exhibits higher frequency variability (2 years) than thoseobserved over central-eastern Argentina (3 to 8 years), while to the west, cyclesof variability are detected between 10 and 14 years. This thesis studied the relationship between the anomaly of sea surfacetemperature (SST) at the tropical and subtropical oceans and extreme dailyrainfall in Argentina. We also explore the dynamical mechanisms associated withregional and global scale. An analysis of singular value decomposition (SVD)was made that shows that a combined influence of the Pacific (linked to ENSO, Niño Modoki) the Indian Ocean (related to the IOD), and the Atlantic (associatedwith the AMO and the TSA), influence the variability the three leading modesresulting from the SVD analysis. Although, the influence of each identified oceanregion over the DIER75 activity is not the same. Moreover, it was found that theinfluence of tropical ocean regions on the extremes of daily precipitation in Argentina is associated with Rossby wave trains emanating from the central andwestern Pacific and Indian Oceans extending towards South America, promotingthe convergence or divergence of moisture in southeastern South America. Exploratory work was carried out on how global warming signal as described byglobal SSTs affects the observed covariability between SST anomalies and DIER75 in Argentina. We found that global warming weakens the influence of SSTs in the central Pacific associated with ENSO. Conversely, the magnitude ofthe correlations with the tropical Indian and Atlantic intensify. Fil: Robledo, Federico Ariel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

International audience; The ability of four regional climate models to reproduce the present-day South American climate is examined with emphasis on La Plata Basin. Models were integrated for the period 1991-2000 with initial and lateral boundary conditions from ERA-40 Reanalysis. The ensemble sea level pressure, maximum and minimum temperatures and precipitation are evaluated in terms of seasonal means and extreme indices based on a percentile approach. Dispersion among the individual models and uncertainties when comparing the ensemble mean with different climatologies are also discussed. The ensemble mean is warmer than the observations in South Eastern South America (SESA), especially for minimum winter temperatures with errors increasing in magnitude towards the tails of the distributions. The ensemble mean reproduces the broad spatial pattern of precipitation, but overestimates the convective precipitation in the tropics and the orographic precipitation along the Andes and over the Brazilian Highlands, and underestimates the precipitation near the monsoon core region. The models overestimate the number of wet days and underestimate the daily intensity of rainfall for both seasons suggesting a premature triggering of convection. The skill of models to simulate the intensity of convective precipitation in summer in SESA and the variability associated with heavy precipitation events (the upper quartile daily precipitation) is far from satisfactory. Owing to the sparseness of the observing network, ensemble and observations uncertainties in seasonal means are comparable for some regions and seasons.

a) Proyecto de obtención de Fertilizantes a base de azufre. Proyecto Repsol-YPF. b) Proyecto de obtención de Fertilizantes a base de yeso. Pruebas con diferentes aglutinantes. Proyecto Repsol-YPF. c) Proyecto de tratamiento de aguas arsenicales. d) Proyecto de preparación de diferentes catalizadores de óxido de manganeso, cerio y cobre para la eliminación de fenoles en agua. e) Reciclado de Pilas Alcalinas.

International audience; Plants have remarkable developmental plasticity, and the same genotype can result in different phenotypes depending on environmental variation. Indeed, abiotic stresses or biotic interactions affect organogenesis and post-embryonic growth and significantly affect gene regulation. The large diversity of non-protein-coding RNAs (npcRNAs) and genes containing only short open reading frames that are expressed during plant growth and development, contribute to the regulation of gene expression. Certain npcRNAs code for oligopeptides and may possess additional biological activity linked to the RNA moiety. The ENOD40 gene is a dual RNA that is activated during a symbiotic interaction leading to root nodule organogenesis. Both the oligopeptides encoded by ENOD40 and the structured regions of the ENOD40 RNA have been shown to interact with different proteins in the cell to control enzymatic activities or induce the relocalisation of ribonucleoproteins, respectively. Other npcRNAs encode for small signalling peptides or are the precursors of small RNAs involved in post-transcriptional or transcriptional gene silencing. They may have RNA-related activities or encode peptides (or even larger proteins), and therefore act as dual RNAs. In addition, long natural antisense RNAs with a coding function and a regulatory RNA-mediated action that are expressed in response to abiotic stress in plants have been identified. In certain cases, these RNAs lead to the synthesis of nat-siRNAs, that are small RNAs derived from the overlapping double-stranded RNA region of natural antisense RNAs, which facilitates the silencing of complementary mRNAs. Finally, the advent of deep sequencing technologies has identified a large number of non-protein-coding RNAs in plants, which could be a large reservoir for dual RNAs.