1,720,995 research outputs found
Improving resistance of traditional Italian tomato cultivars against biotic stress
No full textThis thesis begins with a general introduction and aims of the research as Section 1 which underscores the importance of traditional tomato varieties, such as the San Marzano cultivar, in agriculture. It highlights the vulnerabilities of these cultivars to various bacterial and fungal pathogens, which lead to significant crop losses. The introduction also explores the potential of gene-editing technologies, particularly CRISPR/Cas9, in addressing these challenges by enhancing disease resistance while preserving the desired traits of traditional cultivars.
In Section 2, the focus is on the design of three knockout plasmids targeting the susceptibility genes SlPelo, SlDMR6-1, and SlMlo1. These genes were selected for their roles in weakening the plant’s defense mechanisms against pathogens. The CRISPR/Cas9-based constructs were assembled using the GoldenBraid [GB] cloning system and introduced into the San Marzano cultivar via Agrobacterium tumefaciens. The aim was to generate plants with improved resistance to biotic stress by disrupting these susceptibility genes.
Section 3 covers the pathogenicity assays performed on tomato cultivars to assess their responses to bacterial and fungal pathogens. The assays included tests on PL mutant Micro-Tom plants, which carry a CRISPR-induced mutation in the SlPL gene. These experiments demonstrated how the targeted gene knockouts affected the plants' resistance, providing valuable insights into the effectiveness of CRISPR-mediated gene editing in combating plant diseases.
Section 4 investigates the role of CsLOB1 and SlLOB1 in cell wall degradation during Xanthomonas citri infection. The study demonstrates that ectopic expression of these transcription factors in Nicotiana benthamiana and Micro-Tom tomato fruit leads to significant cell wall degradation and increased oligogalacturonide [OG] production. This release of OGs provides carbon sources for the pathogen, facilitating bacterial growth in the plant apoplast. The results confirm that LOB1 transcription factors play a key role in modulating host cell wall dynamics, enhancing the susceptibility of plants to Xanthomonas infections, and offering insights into potential strategies for mitigating such vulnerabilities.
The thesis concludes by demonstrating the potential of CRISPR/Cas9 technology in improving disease resistance in traditional Italian tomato cultivars, offering a promising pathway for developing resilient crops without compromising their agricultural value
CHARACTERIZATION OF ARABIDOPSIS INSERTIONAL MUTANTS FOR COPPER-CONTAINING AMINE OXIDASES.
No full textIn plants, polyamines are catabolised by amine oxidases, which are present in different sub-cellular compartments. The chemical identity of AO-catalyzed reaction products depends on mode of polyamine oxidation, hydrogen peroxide representing a shared compound in all the AO-mediated reactions. It has been suggested that AO-mediated hydrogen peroxide production in the apoplast is involved in signalling pathways leading to stress and defence responses. Herein, a study on the physiological roles of cell wall-localized copper containing- (Cu)-AOs has been carried out. In Arabidopsis, ten putative CuAO genes have been identified, four of which (AtCuAO 1-4) encoding for proteins with a deduced extracellular localization. Insertional mutant lines for these genes were genotypically characterised by PCR, RT-PCR and Southern-blot analysis in order to identify the homozygous plants for single-locus T-DNA insertion and to confirm the absence of the full-length gene transcripts. Plant phenotype analysis revealed that methyl jasmonate (MeJA) treatments differently affects root growth of mutant and wild type plants, i.e. root growth of atcuao1 plants is less inhibited than wild type plants
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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