Fertility of CMS wheat is restored by two Rf loci located on a recombined acrocentric chromosome

Cytoplasmic male sterility (CMS) results from incompatibility between nuclear and cytoplasmic genomes, and is characterized by the inability to produce viable pollen. The restoration of male fertility generally involves the introgression of nuclear genes, termed restorers of fertility (Rf). CMS has been widely used for hybrid seed production in many crops but not in wheat, partly owing to the complex genetics of fertility restoration. In this study, an acrocentric chromosome that restores pollen fertility of CMS wheat in Hordeum chilense cytoplasm (msH1 system) is studied. The results show that this chromosome, of H. chilense origin and named Hchac, originated from a complex reorganization of the short arm of chromosomes 1Hch (1HchS) and 6Hch (6HchS). Diversity arrays technology (DArT) markers and cytological analysis indicate that Hchac is a kind of 'zebra-like′ chromosome composed of chromosome 1HchS and alternate fragments of interstitial and distal regions of chromosome 6HchS. PCR-based markers together with FISH, GISH, and meiotic pairing analysis support this result. A restorer of fertility gene, named Rf 6H ch S, has been identified on the short arm of chromosome 6HchS. Moreover, restoration by the addition of chromosome 1HchS has been observed at a very low frequency and under certain environmental conditions. Therefore, the results indicate the presence of two Rf genes on the acrocentric chromosome: Rf 6H ch S and Rf 1H ch S, the restoration potential of Rf 6H ch S being greater. The stable and high restoration of pollen fertility in the msH1 system is therefore the result of the interaction between these two restorer genes.Results have been achieved within the framework of the Transnational (Germany, France, Spain, Portugal and Canada) Cooperation within the PLANT-KBBE Initiative, with funding from Spanish Ministerio de Economía y Competitividad project PIM2010PKB-00703  “Hybrid Wheat for Reduced Inputs and Sustainable Yield”. This research was partly supported by grant (to S.G. Atienza) 200840I137 from CSIC and FEDER.Peer Reviewe

Exploitation of nuclear and cytoplasm variability in Hordeum chilense for wheat breeding

Hordeum chilense Roem. et Schultz. is a diploid wild barley native to Chile and Argentina. The high crossability of this species with other members of the Triticeae tribe promoted the development of the new species × Tritordeum Ascherson et Graebner. Hexaploid tritordeum was developed from the hybrid derived from the cross between H. chilense (used as female parent) and durum wheat. The interest of H. chilense is based on the presence of traits potentially useful for wheat breeding, including high endosperm carotenoid content, septoria tritici blotch resistance and abiotic stress tolerance. Besides, the variability at cytoplasm level is also important in this species. The development of common wheat-H. chilense alloplasmic lines (nucleus from wheat and cytoplasm from H. chilense) results in fertile or male sterile genotypes, depending on the accession donating the cytoplasm. Furthermore, these alloplasmic lines constitute an ideal system for deepening our knowledge on nuclear-cytoplasm interactions. In conclusion, H. chilense is an interesting source of variability for wheat breeding. © 2011 NIAB.Our work in this area is supported by grants (to S. G. A.) AGL2008-03720, and P09-AGR-4817 from Spanish Ministry of Science and Innovation, Junta de Andalucía and FEDER. C. R.-S. acknowledges financial support from CSIC (JAE-Doc program).Peer Reviewe

Genome-Wide Transcription During Early Wheat Meiosis Is Independent of Synapsis, Ploidy Level, and the Ph1 Locus

Polyploidization is a fundamental process in plant evolution. One of the biggest challenges faced by a new polyploid is meiosis, particularly discriminating between multiple related chromosomes so that only homologous chromosomes synapse and recombine to ensure regular chromosome segregation and balanced gametes. Despite its large genome size, high DNA repetitive content and similarity between homoeologous chromosomes, hexaploid wheat completes meiosis in a shorter period than diploid species with a much smaller genome. Therefore, during wheat meiosis, mechanisms additional to the classical model based on DNA sequence homology, must facilitate more efficient homologous recognition. One such mechanism could involve exploitation of differences in chromosome structure between homologs and homoeologs at the onset of meiosis. In turn, these chromatin changes, can be expected to be linked to transcriptional gene activity. In this study, we present an extensive analysis of a large RNA-seq data derived from six different genotypes: wheat, wheat–rye hybrids and newly synthesized octoploid triticale, both in the presence and absence of the Ph1 locus. Plant material was collected at early prophase, at the transition leptotene-zygotene, when the telomere bouquet is forming and synapsis between homologs is beginning. The six genotypes exhibit different levels of synapsis and chromatin structure at this stage; therefore, recombination and consequently segregation, are also different. Unexpectedly, our study reveals that neither synapsis, whole genome duplication nor the absence of the Ph1 locus are associated with major changes in gene expression levels during early meiotic prophase. Overall wheat transcription at this meiotic stage is therefore highly resilient to such alterations, even in the presence of major chromatin structural changes. Further studies in wheat and other polyploid species will be required to reveal whether these observations are specific to wheat meiosis

Use of interactive response devices for the improvement of teaching in the degrees of the Faculty of Sciences

La implantación de los nuevos Grados dentro del EEES supone un nuevo enfoque metodológico, pero sobre todo evaluador. El profesor debe esforzarse en ser capaz de valorar no sólo el nivel de conocimientos del alumnado sobre los contenidos, ya que la sociedad actual demanda un perfil de los egresados más completo basado en la formación por competencias. La adquisición de ambas facetas por parte del alumnado se basa principalmente en actividades presenciales y metodologías docentes aplicadas en el desarrollo de las asignaturas, tanto en grupo reducido como en grupo completo. Por tanto, cualquier herramienta adicional que ayude al docente a facilitar esta doble tarea es bien recibida, pues permitirá evaluar el rendimiento académico global del alumnado. Recientemente la Facultad de Ciencias ha puesto en marcha una experiencia piloto mediante la cual un nutrido grupo de profesores ha incorporado en su docencia un sistema de mandos inalámbricos de respuesta. Actualmente, la Facultad de Ciencias dispone de un total de 82 mandos inalámbricos de respuesta y tres antenas receptoras. Esta nueva tecnología ha permitido al docente realizar, de forma interactiva, preguntas colectivas al alumnado y recoger las respuestas individuales de forma inmediata. Los resultados obtenidos en este proyecto nos permiten ser muy optimistas con el uso de esta herramienta y nos animan a continuar en la misma línea. El profesorado participante se ha mostrado dispuesto a continuar empleando esta TIC en su docencia, tratando de abarcar más asignaturas, diversificar el tipo de pruebas, y emplear los mandos de respuesta en grupo completo, cuando el número de alumnos lo permita. La puesta en común de los resultados revela que, de forma general, este tipo de sistemas de respuesta incrementa el nivel de atención del alumnado, ya que se les demanda de forma continuada su participación activa durante la sesión. Se potencia la retención de conceptos, al suministrar en el acto la respuesta correcta a cada pregunta realizada. Permite también al profesorado conocer el nivel previo de conocimientos sobre la materia a impartir, ya que se puede realizar este tipo de preguntas al comienzo de la sesión y enfocar entonces su atención en las debilidades manifestadas. Asimismo se puede testar el grado de adquisición de dichos conocimientos, realizando este tipo de cuestionarios después de la sesión. Además, el tratamiento posterior de los resultados, de forma individualizada, permite gestionar de forma ágil el nivel de conocimientos y adquisición de competencias en lo que es un sistema de evaluación continua, tan necesario en los nuevos enfoques metodológicos nacidos de la implantación del EEES. Por último destacar que el profesorado participante ha considerado que se trata de una herramienta de gran utilidad para la consecución del objetivo de excelencia en la docencia, que además es eficaz y de fácil manejo, y entiende que no debe ser una actividad puntual, sino un proceso transformador en la actividad docente e interacción alumno-profesor, configurándose como una herramienta habitual en los sistemas de enseñanza-aprendizaje.Implementation of the new degrees in the EHEA involve a new methodological approach, but above all evaluation. The teacher should strive to be able to assess not only the level of knowledge of the students on the content, as the current society demands a profile of the most complete graduates based on training by competencies. The acquisition of both facets by students is based mainly on face-to-face activities and teaching methodologies applied in the development of the subjects, both in small group and in whole group. Therefore, any additional tool that helps the teacher to facilitate this double task is well received, since it will allow to evaluate the overall academic performance of the students. Recently the Faculty of Sciences has launched a pilot experience through which a large group of teachers has incorporated into their teaching a system of interactive response devices. Currently, the Faculty of Sciences has a total of 82 wireless response controllers and three receiving antennas. This new technology has enabled the teacher to interact interactively with the students and collect the individual answers immediately. The results obtained in this project allow us to be very optimistic with the use of this tool and encourage us to continue in the same line. The participating teachers have been willing to continue using this ICT in their teaching, trying to cover more subjects, diversify the type of tests, and use the full group response commands, when the number of students allows. The sharing of results reveals that, in a general way, this type of response systems increases the level of attention of the students, since they are continuously demanded their active participation during the session. The retention of concepts is strengthened by providing the correct answer to every question asked. It also allows the faculty to know the previous level of knowledge about the subject to be taught, since this type of questions can be asked at the beginning of the session and then focus their attention on the weaknesses manifested. It is also possible to test the degree of acquisition of this knowledge, performing this type of questionnaire after the session. In addition, the subsequent treatment of the results, in an individualized way, allows to manage in an agile way the level of knowledge and acquisition of competences in what is a system of continuous evaluation, so necessary in the new methodological approaches born from the implantation of the EHEA. Finally, it should be pointed out that the participating teachers have considered that this is a very useful tool for achieving the objective of excellence in teaching, which is also efficient and easy to use and understands that it should not be a specific activity, but a transforming process in the teaching activity and student-teacher interaction, being configured as a habitual tool in the teaching-learning systems

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

High-throughput genotyping of wheat-barley amphiploids utilising diversity array technology (DArT)

Abstract Background Hordeum chilense, a native South American diploid wild barley, is one of the species of the genus Hordeum with a high potential for cereal breeding purposes, given its high crossability with other members of the Triticeae tribe. Hexaploid tritordeum (×Tritordeum Ascherson et Graebner, 2n=6×=42, AABBHchHch) is the fertile amphiploid obtained after chromosome doubling of hybrids between Hordeum chilense and durum wheat. Approaches used in the improvement of this crop have included crosses with hexaploid wheat to promote D/Hch chromosome substitutions. While this approach has been successful as was the case with triticale, it has also complicated the genetic composition of the breeding materials. Until now tritordeum lines were analyzed based on molecular cytogenetic techniques and screening with a small set of DNA markers. However, the recent development of DArT markers in H. chilense offers new possibilities to screen large number of accessions more efficiently. Results Here, we have applied DArT markers to genotype composition in forty-six accessions of hexaploid tritordeum originating from different stages of tritordeum breeding program and to H. chilense-wheat chromosome addition lines to allow their physical mapping. Diversity analyses were conducted including dendrogram construction, principal component analysis and structure inference. Euploid and substituted tritordeums were clearly discriminated independently of the method used. However, dendrogram and Structure analyses allowed the clearest discrimination among substituted tritordeums. The physically mapped markers allowed identifying these groups as substituted tritordeums carrying the following disomic substitutions (DS): DS1D (1Hch), DS2D (2Hch), DS5D (5Hch), DS6D (6Hch) and the double substitution DS2D (2Hch), DS5D (5Hch). These results were validated using chromosome specific EST and SSR markers and GISH analysis. Conclusion In conclusion, DArT markers have proved to be very useful to detect chromosome substitutions in the tritordeum breeding program and thus they are expected to be equally useful to detect translocations both in the tritordeum breeding program and in the transference of H. chilense genetic material in wheat breeding programs.This research was supported by grants AGL2009-11359 and 200840I137 from the Ministerio de Economía y Competitividad, CSIC and FEDER. This work is included within the CSIC – Agrasys SL collaboration agreement for the development of tritordeum.Peer Reviewe

Contribution of Chromosomes 1HchS and 6HchS to Fertility Restoration in the Wheat msH1 CMS System under Different Environmental Conditions

Exploiting hybrid wheat heterosis has been long pursued to increase crop yield, stability and uniformity. Cytoplasmic male sterility (CMS) systems based in the nuclear-cytoplasmic incompatible interactions are a classic way for hybrid seed production, but to date, no definitive system is available in wheat. The msH1 CMS system results from the incompatibility between the nuclear genome of wheat and the cytoplasmic genome of the wild barley Hordeum chilense. Fertility restoration of the CMS phenotype was first associated with the disomic addition of the short arm of chromosome 6H from H. chilense. In further studies it was observed that chromosome arm 1HchS was also implicated, and the combination of genes in both chromosome arms restored fertility more efficiently. In this work we aim to dissect the effect of each chromosome in fertility restoration when combined in different genomic backgrounds and under different environmental conditions. We propose a model to explain how restoration behaves in the msH1 system and generate valuable information necessary to develop an efficient system for hybrid wheat production.This work was supported by the Spanish Ministerio de Economía y Competitividad (MINECO, AGL2013-43329-R, and AGL2011-22596). FP is supported by a Ramon y Cajal research contract from the MINECO (RYC-2010-07345).Peer reviewe

Wheat, Rye, and Barley Genomes Can Associate during Meiosis in Newly Synthesized Trigeneric Hybrids

Polyploidization, or whole genome duplication (WGD), has an important role in evolution and speciation. One of the biggest challenges faced by a new polyploid is meiosis, in particular, discriminating between multiple related chromosomes so that only homologs recombine to ensure regular chromosome segregation and fertility. Here, we report the production of two new hybrids formed by the genomes of species from three different genera: a hybrid between Aegilops tauschii (DD), Hordeum chilense (HchHch), and Secale cereale (RR) with the haploid genomic constitution HchDR (n = 7× = 21); and a hybrid between Triticum turgidum spp. durum (AABB), H. chilense, and S. cereale with the constitution ABHchR (n = 7× = 28). We used genomic in situ hybridization and immunolocalization of key meiotic proteins to establish the chromosome composition of the new hybrids and to study their meiotic behavior. Interestingly, there were multiple chromosome associations at metaphase I in both hybrids. A high level of crossover (CO) formation was observed in HchDR, which shows the possibility of meiotic recombination between the different genomes. We succeeded in the duplication of the ABHchR genome, and several amphiploids, AABBHchHchRR, were obtained and characterized. These results indicate that recombination between the genera of three economically important crops is possible.This research was funded by the UK Biotechnology and Biological Research Council (BBSRC) through a grant of the Designing Future Wheat (DFW) Institute Strategic Programme (BB/P016855/1) and by the Spanish Ministry of Science, Innovation and Universities through the project PRIMA PCI2020-112027. M.-D.R. is grateful for the Juan de la Cierva-Incorporación contract IJC2018-035272-I from the Spanish Ministry of Science, Innovation and Universities.Peer reviewe