A transcriptomic approach highlights induction of secondary metabolism in citrus fruit in response to Penicillium digitatum infection

<p>Abstract</p> <p>Background</p> <p>Postharvest losses of citrus fruit due to green mold decay, caused by the fungus <it>Penicillium digitaum</it>, have a considerable economic impact. However, little is known about the molecular processes underlying the response of citrus fruit to <it>P. digitatum</it>.</p> <p>Results</p> <p>Here we describe the construction of a subtracted cDNA library enriched in citrus genes preferentially expressed in response to pathogen infection followed by cDNA macroarray hybridization to investigate gene expression during the early stages of colonization of the fruit's peel by <it>P. digitatum</it>. Sequence annotation of clones from the subtracted cDNA library revealed that induction of secondary and amino acid metabolisms constitutes the major response of citrus fruits to <it>P. digitatum </it>infection. Macroarray hybridization analysis was conducted with RNA from either control, wounded, ethylene treated or <it>P. digitatum </it>infected fruit. Results indicate an extensive overlap in the response triggered by the three treatments, but also demonstrated specific patterns of gene expression in response to each stimulus. Collectively our data indicate a significant presence of isoprenoid, alkaloid and phenylpropanoid biosynthetic genes in the transcriptomic response of citrus fruits to <it>P. digitatum </it>infection. About half of the genes that are up-regulated in response to pathogen infection are also induced by ethylene, but many examples of ethylene-independent gene regulation were also found. Two notable examples of this regulation pattern are the genes showing homology to a caffeine synthase and a berberine bridge enzyme, two proteins involved in alkaloid biosynthesis, which are among the most induced genes upon <it>P. digitatum </it>infection but are not responsive to ethylene.</p> <p>Conclusions</p> <p>This study provided the first global picture of the gene expression changes in citrus fruit in response to <it>P. digitatum </it>infection, emphasizing differences and commonalities with those triggered by wounding or exogenous ethylene treatment. Interpretation of the differentially expressed genes revealed that metabolism is redirected to the synthesis of isoprenes, alkaloids and phenylpropanoids.</p

A new set of ESTs and cDNA clones from full-length and normalized libraries for gene discovery and functional characterization in citrus

<p>Abstract</p> <p>Background</p> <p>Interpretation of ever-increasing raw sequence information generated by modern genome sequencing technologies faces multiple challenges, such as gene function analysis and genome annotation. Indeed, nearly 40% of genes in plants encode proteins of unknown function. Functional characterization of these genes is one of the main challenges in modern biology. In this regard, the availability of full-length cDNA clones may fill in the gap created between sequence information and biological knowledge. Full-length cDNA clones facilitate functional analysis of the corresponding genes enabling manipulation of their expression in heterologous systems and the generation of a variety of tagged versions of the native protein. In addition, the development of full-length cDNA sequences has the power to improve the quality of genome annotation.</p> <p>Results</p> <p>We developed an integrated method to generate a new normalized EST collection enriched in full-length and rare transcripts of different citrus species from multiple tissues and developmental stages. We constructed a total of 15 cDNA libraries, from which we isolated 10,898 high-quality ESTs representing 6142 different genes. Percentages of redundancy and proportion of full-length clones range from 8 to 33, and 67 to 85, respectively, indicating good efficiency of the approach employed. The new EST collection adds 2113 new citrus ESTs, representing 1831 unigenes, to the collection of citrus genes available in the public databases. To facilitate functional analysis, cDNAs were introduced in a Gateway-based cloning vector for high-throughput functional analysis of genes <it>in planta</it>. Herein, we describe the technical methods used in the library construction, sequence analysis of clones and the overexpression of <it>CitrSEP</it>, a citrus homolog to the Arabidopsis <it>SEP3 </it>gene, in Arabidopsis as an example of a practical application of the engineered Gateway vector for functional analysis.</p> <p>Conclusion</p> <p>The new EST collection denotes an important step towards the identification of all genes in the citrus genome. Furthermore, public availability of the cDNA clones generated in this study, and not only their sequence, enables testing of the biological function of the genes represented in the collection. Expression of the citrus <it>SEP3 </it>homologue, <it>CitrSEP</it>, in Arabidopsis results in early flowering, along with other phenotypes resembling the over-expression of the Arabidopsis <it>SEPALLATA </it>genes. Our findings suggest that the members of the <it>SEP </it>gene family play similar roles in these quite distant plant species.</p

Automatic inspection of satsuma slices using a machine vision system

Spain is one of the most important producer and exporter of fresh fruit in the world. Part of the Spanish production is commercialised as canned fruit, which represent 7.5% of the food industry and a market of about 4.200 million euros. However, the recent presence in the market of third countries with much lower production costs has reduced the Spanish canned fruit exports to the European Union in 50% in the last four years. This problem is particularly important in the case of satsuma slices, where only a few producers remain in Spain. A complete automation of the whole process is the only way for these enterprises to survive. Although most of the tasks have already been automated, the visual inspection at the end of the line is still performed by operators that separate manually the fruit in commercial categories

Cambios de expresión génica asociados a la respuesta de los frutos cítricos frente a la infección por hongos del género Penicillium

La infección producida por P. digitatum y P. italicum es una de las principales causas de pérdidas durante la postcosecha de frutos cítricos. Los problemas derivados de la aplicación de fungicidas químicos utilizados en su control justifican la búsqueda de alternativas eficaces. El conocimiento de las bases de la interacción planta-patógeno y los mecanismos de defensa de las plantas son fundamentales en el desarrollo de alternativas para el control de patologías vegetales. Hasta la fecha, hay pocos estudios sobre los procesos implicados en la respuesta de defensa de los frutos frente a la infección por hongos fitopatógenos. Durante el desarrollo de este trabajo hemos empleado diferentes aproximaciones de genómica funcional para profundizar en la respuesta de los frutos cítricos a la infección por hongos del género Penicillium. Hemos elaborado dos bibliotecas de cDNA: RindPdig24 se obtuvo de frutos de mandarina 'Clemenules' a las 24 horas después de ser heridos e infectados por P. digitatum, mientras que PostharvP1 se obtuvo de frutos de mandarina 'Clemenules' heridos y frutos heridos e infectados por P. digitatum a diferentes tiempos, y está enriquecida en cDNAs de longitud completa. Junto a ellas, se analizó una tercera biblioteca substractiva de cDNA elaborada previamente, RindPdigS, enriquecida en genes específicos de infección de naranja 'Navelina'. La secuenciación masiva de clones de estas tres bibliotecas, su anotación y categorización funcional ha permitido obtener una representación global de los genes expresados en el fruto de los cítricos durante el proceso de infección. Así, se han secuenciado un total de 2.505 clones distintos e identificado 1.941 unigenes. Los datos se han integrado en el Proyecto Español de Genómica Funcional de Cítricos (CFGP). El 25% del total de clones no tienen homología en las bases de datos públicas y el 26% de los unigenes no están presentes en ninguna otra biblioteca de cDNA del CFGP. Estos datos indican que la respuesta del fAlamar Cort, S. (2009). Cambios de expresión génica asociados a la respuesta de los frutos cítricos frente a la infección por hongos del género Penicillium [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/4340Palanci

Usability and value of a digital learning resource in nursing education across European countries: a cross-sectional exploration

Background Higher education is responsible for providing education that meets international benchmarks relevant to the needs of the international community. Due to the increase of digital tools in higher education, the possibility of sharing learning resources across nations has expanded. In the current project, a Norwegian university invited universities in Spain and the United Kingdom to adapt and translate e-learning resources originally developed for Norwegian nursing students for use within their respective Bachelor in Nursing programmes. Aim The aim of the current study was to gain insights into the usability and value for learning of e-compendiums shared and implemented across three European universities. Methods The study adopted a descriptive cross-sectional design and included nursing students from the University of Nottingham, Valencia Catholic University, and the University of Stavanger. Data were collected in Autumn 2017 through a questionnaire adapted from the validated “Centre for Excellence in Teaching and Learning Reusable Learning Object evaluation questionnaire” The questionnaire consisted of 19 items that included two aspects: e-compendiums’ value for learning and e-compendiums’ usability. The different study sites were compared using a binary logistic regression analysis. Subgroups of students were compared based on their gender and age. Results A total of 480 nursing students participated in the study. The e -compendiums were overall positively rated, especially for reinforcing and retaining knowledge. Compared to the students from the University of Stavanger, students from Valencia Catholic University rated the e-compendiums more positively in most aspects of learning. Students from University of Nottingham found the e-compendiums to be more important for learning engagement compared to students at the Norwegian study site, and no differences were found in any other aspects of learning. Younger students rated the interactivity and visual components as more important compared to older students. Conclusions Students from the University of Nottingham and Valencia Catholic University seem to accept the e-compendiums despite the fact that they were originally developed for use in another country. We argue that, when sharing e-learning resources across countries, an adaptation and translation process that includes a multicultural and multidisciplinary perspective should be carried out.publishedVersio

Can we improve the birth weight prediction? : the effect of normal BMI using a multivariate model

Objectivo: construir un modelo predictivo que mejore la estimación del peso del recién nacido (PFE). Material y Métodos: Estudio observacional dónde 140 gestantes fueron estudiadas mediante un muestreo bietápico en un Departamento de Salud en España. Fueron clasificadas en cuatro grupos dependiendo del IMC pregestacional materno. El peso proyectado al nacer fue estimado por la ecografía realizada entre las 33-35 semanas de gestación (PP40s). Se construyó un modelo de regresión con las variables que se reaccionaban con el peso al nacer, altura uterina (AU), PP40s, edad gestacional (EG), nivel de ferritina y cigarillos consumidos. Resultados: Se construyó un modelo multivariante para el grupo Normo-peso para estimar el peso al nacer (PFm) obteniendo una R2=0,727 (p<0,001). Las diferencias de las medias obtenidas entre PP40s y PFm, con el peso del recién nacido, fueron significativas (p<0,001). El PFm infravalora el peso al nacer en 0,07 g (error medio 0,53%) y la PP40s lo sobrestima en 300,89 g (error medio 10,12%). Para evaluar el modelo predictive y verificar las predicciones realizadas se utilizó el análisis de Bland y Altman. El error medio de la estimación del peso al nacer mediante modelo multivariante fue de 1,94% infraestimando el resultado, en cambio el error cometido por la ecografía sobrestima el resultado en 10,93%. Conclusiones: El modelo multivariante construido, para el grupo NW, mejora la precisión de la ecografía.Objective: The construction of a predictive model that improves the estimation of the fetal weight (EFW). Study Design: a comparative, descriptive study. One hundred forty pregnant women were recruited at two-stage sample in health department in Spain. They were classified in four groups depending on the pre-gestational BMI. Fetal weight at term was estimated by ultrasound at 33-35 weeks (EFW40w) by one gynecologist. A regression model was created with the variables that reacted to the newborn´s weight, symphysis-fundal height (SFH), EFW40w, gestational age (GA), ferritin level and cigarettes smoked. Results: A multivariate model was created for the NW group to estimate the fetal weight (EFWme), resulting in R2=0.727 (p<0.001). The differences of the averages obtained between EFW40w and EFWme, with the newborn´s weight were significant (p<0.001). EFWme underestimates birth weight by 0.07 g (mean error 0.53%), and EFW40w overestimates it by 300.89 g (mean error 10.12%). In order to evaluate the predictive model and verify the predictions we used the Bland-Altman analysis. The average error in estimating the birth weight with EFWme was 1.94% underestimating the result, whereas the ultrasound error overestimated the result 10.93%. Conclusion: The multivariate model created for the NW group improves the accuracy of the ultrasound

Oxalic acid preharvest treatment improves colour and quality of seedless table grape ‘Magenta’ upregulating on-vine ABA metabolism and relative VvNCED1 gene expression and the antioxidant system in berries

The effect of oxalic acid (OA) in determining poorly coloured table grape quality remains relatively unknown. Some red cultivars, such as seedless table grape ‘Magenta’ are characterised by a poor berry colour, an attribute highly demanded by the consumer. The aim of this research was to elucidate the effect of a preharvest OA treatment (5 mM) on berry colour and quality of table grape by investigating its role in berry development, on-vine ripening, and postharvest senescence. We found that OA significantly increased abscisic acid (ABA) and ABA glucose ester (ABA–GE) content in treated berries. This increase was mediated by changes in the ABA biosynthetic pathway, specifically by the upregulation of the 9-cis-epoxycarotenoid dioxygenase (VvNCED1) gene. The accumulation of ABA in treated berries resulted in colour improvement and a higher individual and total anthocyanins content at harvest compared with control; whereas at harvest, OA-treated table grapes showed a significantly lower glucose and fructose content and a higher content of tartaric, ascorbic, and succinic acids. Furthermore, antioxidant enzyme activity was increased during berry development in OA-treated berries. On the other hand, those berries treated with OA showed a delay in loss of firmness and colour during cold storage, as well as less susceptibility to postharvest decay incidence. This effect of OA delaying the senescence process was also related to enzymatic antioxidant system stimulation. For the first time, the role of OA on increasing quality, mainly colour, in table grapes was elucidated, highlighting that this treatment upregulated ABA metabolism, relative VvNCED1 gene expression and antioxidant system, delaying postharvest berry senescence