3D integrated superconducting qubits

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 ($T_1$, $T_{2,\rm{echo}} > 20\,\mu$s) 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

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

Effect of heterologous expression of FT gene from Medicago truncatula in growth and flowering behavior of olive plants

Olive (Olea europaea L. subsp. europaea) is one of the most important crops of the Mediterranean Basin and temperate areas worldwide. Obtaining new olive varieties adapted to climatic changing conditions and to modern agricultural practices, as well as other traits such as biotic and abiotic stress resistance and increased oil quality, is currently required; however, the long juvenile phase, as in most woody plants, is the bottleneck in olive breeding programs. Overexpression of genes encoding the ‘florigen’ Flowering Locus T (FT), can cause the loss of the juvenile phase in many perennials including olives. In this investigation, further characterization of three transgenic olive lines containing an FT encoding gene from Medicago truncatula, MtFTa1, under the 35S CaMV promoter, was carried out. While all three lines flowered under in vitro conditions, one of the lines stopped flowering after acclimatisation. In soil, all three lines exhibited a modified plant architecture; e.g., a continuous branching behaviour and a dwarfing growth habit. Gene expression and hormone content in shoot tips, containing the meristems from which this phenotype emerged, were examined. Higher levels of OeTFL1, a gene encoding the flowering repressor TERMINAL FLOWER 1, correlated with lack of flowering. The branching phenotype correlated with higher content of salicylic acid, indole-3-acetic acid and isopentenyl adenosine, and lower content of abscisic acid. The results obtained confirm that heterologous expression of MtFTa1 in olive induced continuous flowering independently of environmental factors, but also modified plant architecture. These phenotypical changes could be related to the altered hormonal content in transgenic plants

Development of a transgenic early flowering pear (Pyrus communis L.) genotype by RNAi silencing of PcTFL1-1 and PcTFL1-2

Trees require a long maturation period, known as juvenile phase, before they can reproduce, complicating their genetic improvement as compared to annual plants. ‘Spadona’, one of the most important European pear (Pyrus communis L.) cultivars grown in Israel, has a very long juvenile period, up to 14 years, making breeding programs extremely slow. Progress in understanding the molecular basis of the transition to flowering has revealed genes that accelerate reproductive development when ectopically expressed in transgenic plants. A transgenic line of ‘Spadona’, named Early Flowering-Spadona (EF-Spa), was produced using a MdTFL1 RNAi cassette targeting the native pear genes PcTFL1-1 and PcTFL1-2. The transgenic line had three T-DNA insertions, one assigned to chromosome 2 and two to chromosome 14 PcTFL1-1 and PcTFL1-2 were completely silenced, and EF-Spa displayed an early flowering phenotype: flowers developed already in tissue culture and on most rooted plants 1–8 months after transfer to the greenhouse. EF-Spa developed solitary flowers from apical or lateral buds, reducing vegetative growth vigor. Pollination of EF-Spa trees generated normal-shaped fruits with viable F1 seeds. The greenhouse-grown transgenic F1 seedlings formed shoots and produced flowers 1–33 months after germination. Sequence analyses, of the non-transgenic F1 seedlings, demonstrated that this approach can be used to recover seedlings that have no trace of the T-DNA. Thus, the early flowering transgenic line EF-Spa obtained by PcTFL1 silencing provides an interesting tool to accelerate pear breeding

FKF1 conveys timing information for CONSTANS stabilization in photoperiodic flowering

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

FTIP1 Is an Essential Regulator Required for Florigen Transport

FT-INTERACTING PROTEIN 1 is a novel protein that is involved in transporting florigen, a long-known mobile signal that induces flowering in plants in response to day length, from companion cells to sieve elements in the phloem of Arabidopsis

Barley <i>SIX-ROWED SPIKE3</i> encodes a putative Jumonji C-type H3K9me2/me3 demethylase that represses lateral spikelet fertility

The VRS genes of barley control the fertility of the lateral spikelets on the barley inflorescence. Here, Bull et al. show that VRS3 encodes a putative Jumonji C-type histone demethylase that regulates expression of other VRS genes, and genes involved in stress, hormone and sugar metabolism

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

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