Comparative genomic analysis and expression of the APETALA2-like genes from barley, wheat, and barley-wheat amphiploids

<p>Abstract</p> <p>Background</p> <p>The <it>APETALA2</it>-like genes form a large multi-gene family of transcription factors which play an important role during the plant life cycle, being key regulators of many developmental processes. Many studies in <it>Arabidopsis </it>have revealed that the <it>APETALA2 </it>(<it>AP2</it>) gene is implicated in the establishment of floral meristem and floral organ identity as well as temporal and spatial regulation of flower homeotic gene expression.</p> <p>Results</p> <p>In this work, we have cloned and characterised the <it>AP2</it>-like gene from accessions of <it>Hordeum chilense </it>and <it>Hordeum vulgare</it>, wild and domesticated barley, respectively, and compared with other <it>AP2 </it>homoeologous genes, including the Q gene in wheat. The <it>Hordeum AP2</it>-like genes contain two plant-specific DNA binding motifs called AP2 domains, as does the Q gene of wheat. We confirm that the <it>H. chilense AP2</it>-like gene is located on chromosome 5H^ch. Patterns of expression of the <it>AP2</it>-like genes were examined in floral organs and other tissues in barley, wheat and in tritordeum amphiploids (barley × wheat hybrids). In tritordeum amphiploids, the level of transcription of the barley <it>AP2</it>-like gene was lower than in its barley parental and the chromosome substitutions 1D/1H^chand 2D/2H^chwere seen to modify <it>AP2 </it>gene expression levels.</p> <p>Conclusion</p> <p>The results are of interest in order to understand the role of the <it>AP2</it>-like gene in the spike morphology of barley and wheat, and to understand the regulation of this gene in the amphiploids obtained from barley-wheat crossing. This information may have application in cereal breeding programs to up- or down-regulate the expression of <it>AP2</it>-like genes in order to modify spike characteristics and to obtain free-threshing plants.</p

Polinucleótido que comprende secuencias de gliadinas de trigo y su uso para silenciamiento mediante iARN

Peer reviewedConsejo Superior de Investigaciones CientíficasT3 Traducción de patente europe

Polinucleótido que comprende secuencias de gliadinas de trigo y su uso para silenciamiento mediante RNAi

Polinucleótido que comprende secuencias de gliadinas de trigo y su uso para silenciamiento mediante RNAi. La presente invención se refiere al silenciamiento especifico de las (alfa), (beta), (gamma) y ! (omega)- gliadinas de trigo duro y harinero mediante RNA de interferencia (ARNi) por medio del empleo de un polinucleótido que se transcribe a un hpRNA (hairpin RNA). Además, la presente invención también se refiere a un vector, célula, planta o semilla que comprenden el polinucleótido, cuya expresión se dirige de forma específica en tejidos concretos de las semillas de trigo mediante secuencias reguladoras de la expresión génica como por ejemplo, el promotor de un gen de -gliadinas o el promotor del gen que codifica para una D-hordeína.Peer reviewedConsejo Superior de Investigaciones Científicas (España)B1 Patente sin examen previ

Down-Regulating γ-gliadins in bread wheat leads to non-specific increases in other gluten proteins and has no major effect on dough gluten strength.

Background Gliadins are a major component of gluten proteins but their role in the mixing of dough is not well understood because their contribution to wheat flour functional properties are not as clear as for the glutenin fraction. Methodology/Principal Findings Transgenic lines of bread wheat with γ-gliadins suppressed by RNAi are reported. The effects on the gluten protein composition and on technological properties of flour were analyzed by RP-HPLC, by sodium dodecyl sulfate sedimentation (SDSS) test and by Mixograph analysis. The silencing of γ-gliadins by RNAi in wheat lines results in an increase in content of all other gluten proteins. Despite the gluten proteins compensation, in silico analysis of amino acid content showed no difference in the γ-gliadins silenced lines. The SDSS test and Mixograph parameters were slightly affected by the suppression of γ-gliadins. Conclusions/Significance Therefore, it is concluded that γ-gliadins do not have an essential functional contribution to the bread-making quality of wheat dough, and their role can be replaced by other gluten protein

Study of pedagogic qualities of ConQuest and Mercury programs in\ud undergraduate Chemistry teaching

Nas últimas décadas os computadores têm desempenhado\ud importante papel no ensino. Neste trabalho apresentamos resultados obtidos a\ud partir de uma atividade que serviu para avaliar dois programas computacionais\ud que integram uma importante fonte de pesquisas em química, o Banco de\ud Dados Cambridge Structural Database (CSD): ConQuest, utilizado para\ud realização de buscas no CSD e Mercury, utilizado para a visualização de\ud estruturas cristalográficas. O CSD apresenta informações sobre\ud aproximadamente 423.000 estruturas cristalográficas de compostos orgânicos\ud e organometálicos. O Classroom ConQuest, que é uma versão do ConQuest\ud construída para emprego em ambientes de ensino e que foi usada neste\ud trabalho, possui um banco de dados reduzido. Os programas foram avaliados\ud quantitativa e qualitativamente por alunos de graduação matriculados em um\ud curso de química inorgânica, no qual tiveram que solucionar alguns exercícios\ud utilizando a base de dados e os programas ConQuest e Mercury. Os exercícios\ud envolveram a extração e a manipulação de dados disponíveis no CSD. Os\ud questionários de avaliação foram respondidos pelos alunos e mostraram que os\ud programas podem auxiliar no entendimento dos conteúdos da disciplina. Além\ud disso, muitos estudantes consideraram que a atividade os preparou para a\ud utilização de outros bancos de dados e sugeriram que propostas similares\ud poderiam ser aplicadas em disciplinas como cristalografia e química orgânica.For a few decades now, computers have played an increasing role\ud in education. In this work we present the main results from an activity carried\ud out to evaluate two programs that compose an important source of research in\ud chemistry, Cambridge Structural Database (CSD): ConQuest, for searching\ud CSD, and Mercury, for visualizing crystal structures. CSD contains details of\ud approximately 423,000 published organic and organometallic crystal\ud structures. Classroom ConQuest is a version of ConQuest, which has been\ud designed for teaching activities and used in this work, comes with a reduced\ud database. The programs were quantitatively and qualitatively evaluated by\ud Revista Electrónica de Enseñanza de las Ciencias Vol. 7 Nº3 (2008)\ud 659\ud undergraduate students who took an inorganic chemistry course in which they\ud had to solve some inorganic exercises utilizing the database and the programs\ud ConQuest and Mercury. The exercises involved extraction and manipulation of\ud data from CSD. Evaluation questionnaires answered by the students showed\ud that the programs are a valuable aid for content comprehension. Furthermore,\ud many students were optimistic that the activity had prepared them for later\ud use of databases in their chemistry courses and several said that similar\ud activities may be used in courses such as crystallography and organic\ud chemistry.CNPq (472967/2004-5

Higher prevalence of X-ray selected AGN in intermediate age galaxies up to z~1

We analyse the stellar populations in the host galaxies of 53 X-ray selected optically dull active galactic nuclei (AGN) at 0.34<z<1.07 with ultra-deep (m=26.5) optical medium-band (R~50) photometry from the Survey for High-z Absorption Red and Dead Sources (SHARDS). The spectral resolution of SHARDS allows us to consistently measure the strength of the 4000 AA break, Dn(4000), a reliable age indicator for stellar populations. We confirm that most X-ray selected moderate-luminosity AGN (L_X<10^44 erg/s) are hosted by massive galaxies (typically M*>10^10.5 M_sun) and that the observed fraction of galaxies hosting an AGN increases with the stellar mass. A careful selection of random control samples of inactive galaxies allows us to remove the stellar mass and redshift dependencies of the AGN fraction to explore trends with several stellar age indicators. We find no significant differences in the distribution of the rest-frame U-V colour for AGN hosts and inactive galaxies, in agreement with previous results. However, we find significantly shallower 4000 AA breaks in AGN hosts, indicative of younger stellar populations. With the help of a model-independent determination of the extinction, we obtain extinction-corrected U-V colours and light-weighted average stellar ages. We find that AGN hosts have younger stellar populations and higher extinction compared to inactive galaxies with the same stellar mass and at the same redshift. We find a highly significant excess of AGN hosts with Dn(4000)~1.4 and light weighted average stellar ages of 300-500 Myr, as well as a deficit of AGN in intrinsic red galaxies. We interpret failure in recognising these trends in previous studies as a consequence of the balancing effect in observed colours of the age-extinction degeneracy.Comment: Accepted for publication in MNRAS, 12 pages, 8 figures, 1 tabl

Nutrient release through litterfall in short rotation poplar crops in mediterranean marginal land

Producción CientíficaA detailed knowledge of how poplar leaf litter decomposes under Mediterranean marginal conditions can help to minimize fertilization inputs and determine the profitability and sustainability of energy crops established in these particularly sensitive areas for bioenergy. Leaf litter decomposition was monitored for 32 months using the litterbag technique in a poplar crop under short rotation conditions in a marginal Mediterranean area. In addition, nutrient dynamics, together with the production and composition of the woody and foliar biomass produced, were studied for a period of four years. Leaf litter decomposition was relatively slow, particularly during the winter months, and accelerated in early spring, coinciding with the rainy season. At the end of the decomposition study 50% of the initial litterfall was decomposed, releasing roughly 60% of the N, 40% of the K, and 70% of the P initially present in fresh leaves. Annual yields of 6.0 dry Mg ha−1 were obtained. The aerial biomass produced the first year of the second rotation cycle extracted 83, 8.7, and 29 kg ha−1 of N, P, and K, respectively, whereas the amount of nutrients that were estimated to be naturally supplied to the system through leaf litter decomposition were 180 kg ha−1 of N, 19 kg ha−1 of P, and 30 kg ha−1 of K. Therefore, four years after establishing the energy crop, leaf litter was able to release higher amounts of primary macronutrients into the environment than the nutrient uptake by the produced aboveground biomass (woody and foliar biomass).Ministerio de Educación y Ciencia de España - FEDER (PS-120000-2005-6

Removal of methylene blue from aqueous solutions using as biosorbent sargassum muticum: an invasive macroalga in Europe

"This is a preprint of an article accepted for publication in Journal of chemical technology and biotechnology copyright 2005"[Abstract] Methylene blue adsorption on Sargassum muticum, an invasive macroalga in Europe, has been investigated using visible absorption spectroscopy. Different pre-treatments, protonation and chemical cross-linking with CaCl2 or H2CO, have been tested in order to improve the stability as well as the adsorption capacity of the algal biomass. The equilibrium binding has been described in terms of Langmuir or Freundlich isotherms depending on the algal pre-treatment; from the maximum adsorption capacity values, an estimation of the algal specific surface area was made. Moreover, it has been found that adsorption kinetics can be described according to the first order Lagergren model, from which the rate constant and the adsorption capacity were determined. Finally, simple empirical equations were obtained to evaluate the amount of methylene blue removed at any initial concentration and reaction time. The results obtained have shown that this type of material has a high adsorption capacity for methylene blue dye, this feature together with the short times needed to reach the equilibrium suggest that Sargassum muticum can be used as a low-cost biosorbent in wastewater treatments.Ministerio de Ciencia y Tecnología; BQU2002-02133Xunta de Galicia; PGDIT02TAM10302P

Low-gluten, nontransgenic wheat engineered with CRISPR/Cas9

Coeliac disease is an autoimmune disorder triggered in genetically predisposed individuals by the ingestion of gluten proteins from wheat, barley and rye. The a-gliadin gene family of wheat contains four highly stimulatory peptides, of which the 33-mer is the main immunodominant peptide in patients with coeliac. We designed two sgRNAs to target a conserved region adjacent to the coding sequence for the 33-mer in the a-gliadin genes. Twenty-one mutant lines were generated, all showing strong reduction in a-gliadins. Up to 35 different genes were mutated in one of the lines of the 45 different genes identified in the wild type, while immunoreactivity was reduced by 85%. Transgene-free lines were identified, and no off-target mutations have been detected in any of the potential targets. The low-gluten, transgene-free wheat lines described here could be used to produce low-gluten foodstuff and serve as source material to introgress this trait into elite wheat varieties.Ministerio de Economía y Competitividad AGL2013-48946-C3-1-R ; AGL2016-80566-