1,721,005 research outputs found
Fruit development and ripening: a molecular and physiological view modulating and enhancing fruit quality
No full textPiriformospora indica-primed transcriptional reprogramming induces defense response against early blight in tomato
No full textPiriformospora indica is an adaptable mycorrhiza-like fungus belonging to the Sebacinales order that can colonize roots of a wide range of plant species. Studies have shown that P. indica improves growth and enhances systemic defense against pathogens in host plants. However, the mechanism(s) through which these effects occur remain unclear. Therefore to gain more insight into the molecular basis of P. indica induced resistance, cDNA-AFLP (Amplified fragment length polymorphism) based transcript profiling was done to identify differentially expressed genes in P. indica-colonized tomato plants infected with Alternaria solani. Our results demonstrated that pre-colonization of tomato roots with P. indica systemically induced resistance against early blight. Transcript profiling of P. indica pre-colonized tomato plants revealed systemic modulation of several key components of signaling network transcriptional regulators including CBL-interacting protein kinase (CIPK), Mitogen activated protein kinases (MPKs), Lipid transfer proteins (LTPs), WRKY1, ethylene responsive transcription factors (ERF), and Jasmonate Zim Domain 1 (JAZ1), a negative regulator of jasmonic acid (JA) signaling. Expression of downstream defense related genes like Thaumatin-like protein, β-1, 3-glucanase and chitinases was also affected in leaves upon challenge inoculation with pathogen. Interestingly, P. indica pre-colonization alone was unable to induce transcript levels for most of the genes studied. However, pathogen attack on P. indica pre-colonized plants induced strong defense responses. In conclusion, P. indica induces transcriptome reprogramming in a manner that allows rapid and efficient activation of JA/ET (jasmonic acid/ethylene)-mediated basal defenses against pathogen infection by altering the expression of JA/ET related genes. P. indica colonization appears to potentiate the complete signal transduction cascade leading to the systemic expression of defense genes against foliar pathogens. It thus presents itself as a potential and sustainable method of activating multiple components of defense signaling thereby conveying durable horizontal defense against a range of pathogen
Ripening behavior in red flesh ‘Kissabel®’ apple fruit during postharvest
No full textIn the last few years, the cultivation of red flesh apple cultivars received great attention due to their novelty and valuable nutraceutical properties, considering their higher anthocyanin and phenols content than white flesh apple cultivars. Nevertheless, red flesh cultivars can be characterized by a low storability, being therefore prone to develop internal browning disorder. In this preliminary work, we investigated the postharvest ripening behavior of the red flesh apple R201-‘Kissabel®’, a late season cultivar, in comparison with the white pulp apple ‘Golden Delicious’, generally considered as the standard reference cultivar for apple. For this purpose, fruit were collected at commercial harvest and kept for one month at room temperature in regular atmosphere. The cortex of five apple was sampled every two days along this period. Total RNA was extracted, reverse transcribed and RT-qPCR were performed on specific ripening related genes, such as ethylene biosynthetic genes (MdACS3, MdACS1 and MdACO1) and the polygalacturonase-1 (MdPG1). Moreover, proton-transferreaction mass spectrometry (PTR-ToF-MS) was employed to quantify ethylene evolution during the stored period. In ‘Kissabel®’, ethylene started to be accumulated immediately after harvest, and one week earlier than ‘Golden Delicious’. Moreover, both cultivars showed a first peak at 9 and 16 days after harvest (DAH) and a second one at 14 and 21 DHA, respectively. Based on the expression profile of selected genes, the first peak coincided with the ripening onset. In ‘Golden Delicious’, indeed, the highest expression level, for all genes, corresponded with the maximum of ethylene production at 16 DAH. In ‘Kissabel®’ the maximum expression was instead detected two days earlier respect the ethylene burst, while the expression pattern of MdACS3 decreased immediately after harvest in both cultivars, as expected. These results represent the first step to better characterize the ripening behavior and storability of this new apple cultiva
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Genetic dissection of the volatilome-fruit texture interplay in apple
No full textFruit quality is achieved through the combination of several principle quality factors guiding the consumers' preferences. Among them, fruit texture and aroma play major roles. In this study, we aimed to decipher the genetic interplay underlying these two quality features, using a collection of 162 apple accessions employed to assess both fruit texture (through a TAXT-AED texture analyzer device) and the volatilome (by Proton Transfer Reaction - Time of Flight - Mass Spectrometry instrument). The array of phenotypic entities identified in this survey was further integrated into a GWAS analysis together with 9142 SNP markers genotyped with the 20K Illumina Infinium SNP Array. The marker-trait association analysis identified important co-location between QTLs and relevant candidate genes involved in VOC biosynthetic pathways, such as MdAAT1 and MdIGS. The joint integration between the fruit texture and the volatilome through a multiple factor analysis shed light on a contrasting behavior between these two quality aspects. The implementation of the first two principal components led to the identification of two QTLs, located on chromosome 10 and 2, respectively. The subsequent characterization of the apple varieties based on the allelic configuration of two genes, such as MdPG1 and MdACO1, highlighted the genetic interplay existing between fruit texture and VOC production in apple fruit. The genetic control was furthermore validated through a candidate gene transcriptomic approach, revealing a physiological response associated to a determined allelic state of a specific set of ripening-related gene
Transcriptomic investigation of superficial scald onset in ‘Granny Smith’ and ‘Ladina’ apple cultivars during different postharvest storage techniques
No full textDuring postharvest storage at low temperatures, specific apple cultivars can develop a physiological disorder known as superficial scald. This disorder results with the formation of brown or black patches on fruit skin, compromising the entire fruit marketability. In this work, we investigated the effects of different storage strategies distinguished by a different regime of oxygen during the storage of two apple cultivars (‘Granny Smith’ and ‘Ladina’), both susceptible to superficial scald, but with a different magnitude. More precisely, the apples collected from the two cultivars were stored in regular and controlled atmosphere, for five and seven months, respectively. The controlled atmosphere was moreover carried out according to dynamic controlled atmosphere by means of chlorophyll fluorescence and ultra-low oxygen level strategy. After cold storage, apples were kept for one week in regular atmosphere at room temperature, to simulate shelf-life conditions. The apple skin was further collected, and the total amount of RNA was extracted to assess the global transcriptome. In the cultivar ‘Granny Smith’ it was observed that the storage approach carried out with low level of oxygen was efficient in preventing the development of scald symptoms, underlying the central role of the oxidative process in this mechanism. The RNA-Seq analysis highlighted that the samples subjected to the controlled atmosphere were characterized by a high expression of genes related to carbohydrate metabolism and lipid accumulation. ‘Ladina', instead, showed a different behaviour as low oxygen or 1- MCP was less effective in controlling the development of scald compared to ‘Granny Smith’. The different physiological response was also distinguished by a different transcriptional signature, with DEGs more related to ATP biosynthesis, ethylene production, and oxidative stress response. Comparative transcriptomics carried out between these two cultivars provides insights into the gene regulatory network involved in the development of superficial scald in apple
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