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

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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

Evaluacion de Líneas de Triticale para la Producción de Bioetanol

La demanda de biocarburantes ha supuesto un incremento de la utilización de los cereales como materia prima para la producción de bioetanol. El triticale no se usa directamente para la dieta humana, por lo que se presenta como un cultivo alternativo a otros cereales. En este estudio se ha evaluado el potencial del triticale para la producción de bioetanol. Las líneas de triticale presentaron una buena adaptabilidad a las condiciones de cultivo del sur de España, encontrándose correlaciones significativas entre la producción en etanol y la fibra ADF, proteína, almidón, rendimiento e hidratos de carbono totales

Biomass recalcitrance in barley, wheat and triticale straw : Correlation of biomass quality with classic agronomical traits

The global production of cereal straw as an agricultural by-product presents a significant source of biomass, which could be used as feedstock for the production of second generation biofuels by fermentation. The production of sugars for fermentation is an important measure of straw quality and in its suitability for biofuel production. In this paper, we present a characterization of straw digestibility from a wide range of cereal. Our main objective is to evaluate the variability of fermentable sugars released from different species including wheat (Triticum durum L., Triticum aestivum L.), barley (Hordeum vulgare L.) and triticale (X Triticosecale Wittmack). To this end, we adapted a saccharification method (IAS Method) capable of detecting significant differences of released sugars between cultivars and species, while using separately another method that would serve as a control and with which we could contrast our results (CNAP method). ANOVA analyses revealed that barley has a higher saccharification potential than wheat and triticale and shows more variation between genotypes. Thus, populations derived from crosses among them such as Steptoe × Morex and OWB Dominant × OWB Recessive hold potential for the identification of genetic basis for saccharification-related traits. The correlation of glucose released between the two methods was moderate (R2 = 0.57). An evaluation of the inter- and intra- specific correlation between a number of chemical and agronomical parameters and saccharification suggests that the cell wall thickness and lignin content in straw could be used in breeding programs for the improvement of the saccharification potential. Finally, the lack of correlation between grain yield and saccharification suggests that it would be possible to make a selection of genotypes for dual purpose, low recalcitrance and grain yield

Molecular and Immunological Characterization of Gluten Proteins Isolated from Oat Cultivars That Differ in Toxicity for Celiac Disease

A strict gluten-free diet (GFD) is the only currently available therapeutic treatment for patients with celiac disease (CD). Traditionally, treatment with a GFD has excluded wheat, barley and rye, while the presence of oats is a subject of debate. The most-recent research indicates that some cultivars of oats can be a safe part of a GFD. In order to elucidate the toxicity of the prolamins from oat varieties with low, medium, and high CD toxicity, the avenin genes of these varieties were cloned and sequenced, and their expression quantified throughout the grain development. At the protein level, we have accomplished an exhaustive characterization and quantification of avenins by RP-HPLC and an analysis of immunogenicity of peptides present in prolamins of different oat cultivars. Avenin sequences were classified into three different groups, which have homology with S-rich prolamins of Triticeae. Avenin proteins presented a lower proline content than that of wheat gliadin; this may contribute to the low toxicity shown by oat avenins. The expression of avenin genes throughout the development stages has shown a pattern similar to that of prolamins of wheat and barley. RP-HPLC chromatograms showed protein peaks in the alcohol-soluble and reduced-soluble fractions. Therefore, oat grains had both monomeric and polymeric avenins, termed in this paper gliadin- and glutenin-like avenins. We found a direct correlation between the immunogenicity of the different oat varieties and the presence of the specific peptides with a higher/lower potential immunotoxicity. The specific peptides from the oat variety with the highest toxicity have shown a higher potential immunotoxicity. These results suggest that there is wide range of variation of potential immunotoxicity of oat cultivars that could be due to differences in the degree of immunogenicity in their sequences

Allelic Variation, Alternative Splicing and Expression Analysis of Psy1 Gene in Hordeum chilense Roem. et Schult

Background: The wild barley Hordeum chilense Roem. et Schult. is a valuable source of genes for increasing carotenoid content in wheat. Tritordeums, the amphiploids derived from durum or common wheat and H. chilense, systematically show higher values of yellow pigment colour and carotenoid content than durum wheat. Phytoene synthase 1 gene (Psy1) is considered a key step limiting the carotenoid biosynthesis, and the correlation of Psy1 transcripts accumulation and endosperm carotenoid content has been demonstrated in the main grass species. Methodology/Principal findings: We analyze the variability of Psy1 alleles in three lines of H. chilense (H1, H7 and H16) representing the three ecotypes described in this species. Moreover, we analyze Psy1 expression in leaves and in two seed developing stages of H1 and H7, showing mRNA accumulation patterns similar to those of wheat. Finally, we identify thirtysix different transcripts forms originated by alternative splicing of the 59 UTR and/or exons 1 to 5 of Psy1 gene. Transcripts function is tested in a heterologous complementation assay, revealing that from the sixteen different predicted proteins only four types (those of 432, 370, 364 and 271 amino acids), are functional in the bacterial system. Conclusions/Significance: The large number of transcripts originated by alternative splicing of Psy1, and the coexistence of functional and non functional forms, suggest a fine regulation of PSY activity in H. chilense. This work is the first analysis of H. chilense Psy1 gene and the results reported here are the bases for its potential use in carotenoid enhancement in duru

Efecto del silenciamiento de y-gliadinas sobre la calidad y la composición proteica en dos genotipos de trigo harinero

Póster presentado en el VI Congreso de Mejora Genética de Plantas, celebrado en Gijón del 11 al 13 de septiembre de 2012.Las prolaminas están constituidas por mas de 50 proteínas diferentes, las cuales determinan las propiedades harino-panaderas de la harina y su adecuación para la fabricación de pan y otros productos (Shewry et al. 2002). Las proteínas del gluten se han clasificado tradicionalmente en gluteninas y gliadinas. Las gluteninas de alto peso molecular (HMW-GS) son las proteínas principales que determinan la calidad (Halford et al. 1989). Las gliadinas están codificadas por una familia multigénica lo que complica entender en profundidad su contribución a las cualidades viscoelasticas de la harina de trigo (Pistón et al. 2011). En este trabajo se presentan las propiedades tecnológicas de quince líneas transgénicas de trigo harinero, de dos genotipos diferentes, que tienen las γ-gliadinas silenciadas. La composición proteica se analizó mediante RP-HPLC, y las propiedades tecnológicas de la harina se han determinado mediante el test de sedimentación SDS, el Mixografo y el Mixolab®. Estos resultados nos ayudaran a entender mejor el papel de la gliadinas, y mas concretamente de las γ-gliadinas, en las propiedades tecnológicas de la harina de trigo.Peer Reviewe

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)A1 Solicitud de patente con informe sobre el estado de la técnic