1,720,955 research outputs found
UTILIZATION OF THE ENDOPHYTIC FUNGUS PIRIFORMOSPORA INDICA TO IMPROVE SALINITY STRESS TOLERANCE: AN INSIGHT INTO THE DATE PALM’S TRANSCRIPTOMIC AND FUNCTIONAL GENOMIC APPROACHES
Get PDFSustainable agriculture in arid and semi-arid regions depends on managing soil salinity, which is a major environmental issue and a critical component of sustainable food production. Salinity has a significant impact on date palm growth and physiological functions. Plant growth promoting microbiota has become a viable option to improve plant growth and performance under salt stress. Piriformospora indica is a highly versatile root endophyte in agricultural fields capable of coping with salinity. Its role in increasing abiotic stress tolerance has been reported in several plant species, but not in date palms. This research study investigated the growth, biochemical and molecular properties of Phoenix dactylifera colonized with the mutualistic fungus P. indica under control and salinity stress. The research findings indicated enhanced levels of antioxidant enzymes such as catalase, superoxide dismutase, and peroxidase, decreased Na+/K+ ratio in leaves and roots, increased ion content, and improved physiological parameters in date palm plants colonized with P. indica under salinity stress conditions. Transcriptome profiling of date palm roots grown under salt stress (250 mM) with or without inoculation of P. indica revealed that 6,836 genes were differentially expressed, with 3,153 up-regulated genes and 3,683 down-regulated genes. The DEGs were specifically involved in phenylpropanoid biosynthesis, plant-pathogen interaction, plant hormone signal transduction, metabolic pathway, ABC transporters, MAPK signaling pathway, cutin, Suberin and wax biosynthesis, and glutathione metabolism, as revealed by Gene Ontology (GO) and EuKaryotic Orthologous Groups (KOG) enrichment analysis in colonized date palms exposed to salt stress. There are 62 LEA2 genes in date palms that are speculated to retain water molecules and prevent crystallization of cellular components under conditions of drought, heat, and high salinity. The second part of the examination functionally characterized three date palm LEA2 genes, PdLEA2.2, PdLEA2.3, and PdLEA2.4, with respect to their effects on the thermostability of two different enzymes, Lactate Dehydrogenase (LDH) and β-glucosidase (bglG), in vitro. Under heat stress, the purified recombinant PdLEA2 proteins showed elevated LDH activity and reduced aggregate formation, as well as the ability to maintain and stabilize the enzymatic activity of bglG. Finally, the study investigated the role of the PdLEA2.2 gene by analyzing its ectopic pattern (overexpression) in Arabidopsis thaliana plants under salinity stress. Transgenic Arabidopsis plants showed higher salt tolerance with respect to the optimal Na+/K+ ratio and increased antioxidant activity. Based on these findings, date palm production can be improved by exploiting the P. indica fungus as a plant symbiont, increasing its economic sustainability in marginal environments. In addition to demonstrating that date palm LEA2 proteins can act as molecular chaperones for the development of new thermoresistant enzymes with better reaction rates and specificities, PdLEA2 genes would provide the basis for the development of salt stress tolerant plants that are more resilient and productive
UTILIZATION OF THE ENDOPHYTIC FUNGUS PIRIFORMOSPORA INDICA TO IMPROVE SALINITY STRESS TOLERANCE: AN INSIGHT INTO THE DATE PALM\u27S TRANSCRIPTOMIC AND FUNCTIONAL GENOMIC APPROACHES
Get PDFSustainable agriculture in arid and semi-arid regions depends on managing soil salinity, which is a major environmental issue and a critical component of sustainable food production. Salinity has a significant impact on date palm growth and physiological functions. Plant growth promoting microbiota has become a viable option to improve plant growth and performance under salt stress. Piriformospora indica is a highly versatile root endophyte in agricultural fields capable of coping with salinity. Its role in increasing abiotic stress tolerance has been reported in several plant species, but not in date palms. This research study investigated the growth, biochemical and molecular properties of Phoenix dactylifera colonized with the mutualistic fungus P. indica under control and salinity stress. The research findings indicated enhanced levels of antioxidant enzymes such as catalase, superoxide dismutase, and peroxidase, decreased Na+/K+ ratio in leaves and roots, increased ion content, and improved physiological parameters in date palm plants colonized with P. indica under salinity stress conditions. Transcriptome profiling of date palm roots grown under salt stress (250 mM) with or without inoculation of P. indica revealed that 6,836 genes were differentially expressed, with 3,153 up-regulated genes and 3,683 down-regulated genes. The DEGs were specifically involved in phenylpropanoid biosynthesis, plantpathogen interaction, plant hormone signal transduction, metabolic pathway, ABC transporters, MAPK signaling pathway, cutin, Suberin and wax biosynthesis, and glutathione metabolism, as revealed by gene ontology (GO) and EuKaryotic Orthologous Groups (KOG) enrichment analysis in colonized date palms exposed to salt stress. There are 62 LEA 2 genes in date palms that are speculated to retain water molecules and prevent crystallization of cellular components under conditions of drought, heat, and high salinity. We functionally characterized three date palm LEA2 genes, PdLEA2.2, PdLEA2.3, and PdLEA2.4, with respect to their effects on the thermostability of two different enzymes, lactate dehydrogenase (LDH) and β-glucosidase (bglG), in vitro. Under heat stress, the purified recombinant PdLEA2 proteins showed elevated LDH activity and reduced aggregate formation, as well as the ability to maintain and stabilize the enzymatic activity of bglG. Finally, the study investigated the role of the PdLEA2.2 gene by analyzing its ectopic pattern (overexpression) in Arabidopsis thaliana plants under salinity stress. Transgenic Arabidopsis plants showed higher salt tolerance with respect to the optimal Na+/K+ ratio and increased antioxidant activity. Based on these findings, date palm production can be improved by exploiting the P. indica fungus as a plant symbiont, increasing its economic sustainability in marginal environments. In addition to demonstrating that date palm LEA2 proteins can act as molecular chaperones for the development of new thermoresistant enzymes with better reaction rates and specificities, PdLEA2 genes would provide the basis for the development of salt stress tolerant plants that are more resilient and productive
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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