154 research outputs found

    3D integrated superconducting qubits

    Get PDF
    As the field of superconducting quantum computing advances from the few-qubit stage to larger-scale processors, qubit addressability and extensibility will necessitate the use of 3D integration and packaging. While 3D integration is well-developed for commercial electronics, relatively little work has been performed to determine its compatibility with high-coherence solid-state qubits. Of particular concern, qubit coherence times can be suppressed by the requisite processing steps and close proximity of another chip. In this work, we use a flip-chip process to bond a chip with superconducting flux qubits to another chip containing structures for qubit readout and control. We demonstrate that high qubit coherence (T1T_1, T2,echo>20μT_{2,\rm{echo}} > 20\,\mus) is maintained in a flip-chip geometry in the presence of galvanic, capacitive, and inductive coupling between the chips

    Transformación genética de olivo (Olea europaea L.) con un gen de Medicago truncatula que codifica para un proteína tipo FT

    Get PDF
    En el olivo (Olea europaea L.), la modificación de la arquitectura de la planta y la reducción del periodo juvenil son caracteres de interés en la mejora. Las proteínas codificadas por genes tipo FT (FLOWERING LOCUS T), además de actuar como componente principal de la señal sistémica inductora de floración conocida como florígeno, participan en la regulación de otros procesos del desarrollo en plantas, entre ellos, la determinación de la arquitectura o la dormancia. El objetivo de este trabajo es abordar la transformación genética de olivo con el gen MtFTa1 de Medicago truncatula, para estudiar su aplicación en la mejora. La transformación genética se llevó a cabo utilizando embriones somáticos, derivados de radícula de embrión zigótico, siguiendo el protocolo previamente establecido en nuestro laboratorio (Torreblanca et al. 2010, PCTOC 103:61-69). Se utilizaron la cepa de Agrobacterium AGL-1 y el vector binario Pro35S:MtFTA portando el gen nptII como gen de selección y el gen MtFTa1 bajo el control del promotor constitutivo CaMV35S. La regeneración de plantas se realizó siguiendo el protocolo previamente desarrollado en nuestro grupo de trabajo (Cerezo et al. 2011, PCTOC 106:337-344). Se obtuvo una tasa de transformación del 2,5%, recuperándose quince líneas transgénicas independientes. La expresión del transgén se analizó mediante qRT-PCR. En tres de las seis líneas con mayores niveles de expresión se observó floración precoz in vitro, mientras que las otras tres líneas transgénicas florecieron en invernadero de confinamiento, transcurridos 18-36 meses desde su aclimatación. Las flores obtenidas presentaron morfología irregular y no produjeron polen viable. Además, las plantas mostraron alteraciones en el crecimiento, como pérdida de dominancia apical y desarrollo continuo de yemas laterales. Por otro lado, en plantas aclimatadas que no florecieron tan precozmente, también se observó un mayor grado de ramificación en el eje principal en relación a las plantas control, con una menor longitud de entrenudos y mayor porcentaje de yemas axilares brotadas en ramos laterales de primer orden. Los resultados de este trabajo ponen de manifiesto el papel del gen FT en la regulación de la floración y arquitectura de las plantas de olivo.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Proyecto de Excelencia Junta de Andalucía P11-AGR-7992

    FKF1 conveys timing information for CONSTANS stabilization in photoperiodic flowering

    Get PDF
    Plants use day-length information to coordinate flowering time with the appropriate season to maximize reproduction. In Arabidopsis, the long-day specific expression of CONSTANS (CO) protein is crucial for flowering induction. Although light signaling regulates CO protein stability, the mechanism by which CO is stabilized in the long-day afternoon has remained elusive. Here we demonstrate that FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 (FKF1) protein stabilizes CO protein in the afternoon in long days. FKF1 interacts with CO through its LOV domain, and blue light enhances this interaction. In addition, FKF1 simultaneously removes CYCLING DOF FACTOR 1 (CDF1) that represses CO and FLOWERING LOCUS T (FT) transcription. Together with CO transcriptional regulation, FKF1 protein controls robust FT mRNA induction through multiple feedforward mechanisms that accurately control flowering timing

    Mice have a transcribed L-threonine aldolase/GLY1 gene, but the human GLY1 gene is a non-processed pseudogene

    Get PDF
    BACKGROUND: There are three pathways of L-threonine catabolism. The enzyme L-threonine aldolase (TA) has been shown to catalyse the conversion of L-threonine to yield glycine and acetaldehyde in bacteria, fungi and plants. Low levels of TA enzymatic activity have been found in vertebrates. It has been suggested that any detectable activity is due to serine hydroxymethyltransferase and that mammals lack a genuine threonine aldolase. RESULTS: The 7-exon murine L-threonine aldolase gene (GLY1) is located on chromosome 11, spanning 5.6 kb. The cDNA encodes a 400-residue protein. The protein has 81% similarity with the bacterium Thermotoga maritima TA. Almost all known functional residues are conserved between the two proteins including Lys242 that forms a Schiff-base with the cofactor, pyridoxal-5'-phosphate. The human TA gene is located at 17q25. It contains two single nucleotide deletions, in exons 4 and 7, which cause frame-shifts and a premature in-frame stop codon towards the carboxy-terminal. Expression of human TA mRNA was undetectable by RT-PCR. In mice, TA mRNA was found at low levels in a range of adult tissues, being highest in prostate, heart and liver. In contrast, serine/threonine dehydratase, another enzyme that catabolises L-threonine, is expressed very highly only in the liver. Serine dehydratase-like 1, also was most abundant in the liver. In whole mouse embryos TA mRNA expression was low prior to E-15 increasing more than four-fold by E-17. CONCLUSION: Mice, the western-clawed frog and the zebrafish have transcribed threonine aldolase/GLY1 genes, but the human homolog is a non-transcribed pseudogene. Serine dehydratase-like 1 is a putative L-threonine catabolising enzyme

    Repression of Floral Meristem Fate Is Crucial in Shaping Tomato Inflorescence

    Get PDF
    Tomato is an important crop and hence there is a great interest in understanding the genetic basis of its flowering. Several genes have been identified by mutations and we constructed a set of novel double mutants to understand how these genes interact to shape the inflorescence. It was previously suggested that the branching of the tomato inflorescence depends on the gradual transition from inflorescence meristem (IM) to flower meristem (FM): the extension of this time window allows IM to branch, as seen in the compound inflorescence (s) and falsiflora (fa) mutants that are impaired in FM maturation. We report here that JOINTLESS (J), which encodes a MADS-box protein of the same clade than SHORT VEGETATIVE PHASE (SVP) and AGAMOUS LIKE 24 (AGL24) in Arabidopsis, interferes with this timing and delays FM maturation, therefore promoting IM fate. This was inferred from the fact that j mutation suppresses the high branching inflorescence phenotype of s and fa mutants and was further supported by the expression pattern of J, which is expressed more strongly in IM than in FM. Most interestingly, FA - the orthologue of the Arabidopsis LEAFY (LFY) gene - shows the complementary expression pattern and is more active in FM than in IM. Loss of J function causes premature termination of flower formation in the inflorescence and its reversion to a vegetative program. This phenotype is enhanced in the absence of systemic florigenic protein, encoded by the SINGLE FLOWER TRUSS (SFT) gene, the tomato orthologue of FLOWERING LOCUS T (FT). These results suggest that the formation of an inflorescence in tomato requires the interaction of J and a target of SFT in the meristem, for repressing FA activity and FM fate in the IM

    Control of Flowering in Strawberries

    Get PDF
    Strawberries (Fragaria sp.) are small perennial plants capable of both sexual reproduction through seeds and clonal reproduction via runners. Because vegetative and generative developmental programs are tightly connected, the control of flowering is presented here in the context of the yearly growth cycle. The rosette crown of strawberry consists of a stem with short internodes produced from the apical meristem. Each node harbors one trifoliate leaf and an axillary bud. The fate of axillary buds is dictated by environmental conditions; high temperatures and long days (LDs) promote axillary bud development into runners, whereas cool temperature and short days (SDs) favor the formation of branch crowns. SDs and cool temperature also promote flowering; under these conditions, the main shoot apical meristem is converted into a terminal inflorescence, and vegetative growth is continued from the uppermost axillary branch crown. The environmental factors that regulate vegetative and generative development in strawberries have been reasonably well characterized and are reviewed in the first two chapters. The genetic basis of the physiological responses in strawberries is much less clear. To provide a point of reference for the flowering pathways described in strawberries so far, a short review on the molecular mechanisms controlling flowering in the model plant Arabidopsis is given. The last two chapters will then describe the current knowledge on the molecular mechanisms controlling the physiological responses in strawberries.Peer reviewe
    corecore