1,720,959 research outputs found
Environmental genome-wide association studies across precipitation regimes reveal that the E3 ubiquitin ligase MBR1 regulates plant adaptation to rainy environments
No full text: In an era characterized by rapidly changing and less-predictable weather conditions fueled by the climate crisis, understanding the mechanisms underlying local adaptation in plants is of paramount importance for the conservation of species. As the frequency and intensity of extreme precipitation events increase, so are the flooding events resulting from soil water saturation. The subsequent onset of hypoxic stress is one of the leading causes of crop damage and yield loss. By combining genomics and remote sensing data, it is now possible to probe natural plant populations that have evolved in different rainfall regimes and look for molecular adaptation to hypoxia. Here, using an environmental genome-wide association study (eGWAS) of 934 non-redundant georeferenced Arabidopsis ecotypes, we have identified functional variants of the gene MED25 BINDING RING-H2 PROTEIN 1 (MBR1). This gene encodes a ubiquitin-protein ligase that regulates MEDIATOR25 (MED25), part of a multiprotein complex that interacts with transcription factors that act as key drivers of the hypoxic response in Arabidopsis, namely the RELATED TO AP2 proteins RAP2.2 and RAP2.12. Through experimental validation, we show that natural variants of MBR1 have different effects on the stability of MED25 and, in turn, on hypoxia tolerance. This study also highlights the pivotal role of the MBR1/MED25 module in establishing a comprehensive hypoxic response. Our findings show that molecular candidates for plant environmental adaptation can be effectively mined from large datasets. This thus supports the need for integration of forward and reverse genetics with robust molecular physiology validation of outcomes
Inferring hypoxia-responsive regulators of cell fate in plant meristems through single-cell transcriptomics
Full text linkSingle-cell sequencing (scRNA-seq) is transforming our ability to dissect cell type-specific gene
regulatory networks underlying developmental processes and cellular differentiation with
unprecedented resolution. By leveraging single-cell transcriptomes of Arabidopsis thaliana shoot and
root apical meristems, we aimed to dissect the complex spatiotemporal interplay between stem cell
identity and hypoxia. Single-cell transcriptomic profiling demonstrated a substantial overlap between
hypoxia-responsive gene expression and stem cell markers across shoot and root meristems.
Trajectory inference coupled with RNA velocity revealed that hypoxia-related transcriptional
signatures are enriched in undifferentiated stem cells and gradually decline as differentiation
progresses, supporting a critical role for hypoxia in cell fate determination. Our findings suggest that
the activation of hypoxia signaling may be a conserved feature in the shoot and root apical meristems
of Arabidopsis thaliana and could play a crucial role in regulating stem cell fate decisions during
development
The transcription factor ORA59 represses hypoxia responses during Botrytis cinerea infection and reoxygenation
No full text: Transcription factors belonging to the large ethylene response factor (ERF) family are involved in plant responses to biotic and abiotic stresses. Among the ERFs, OCTADECANOID-RESPONSIVE ARABIDOPSIS 59 (ORA59) integrates ethylene and jasmonic acid signaling to regulate resistance to necrotrophic pathogens. The ERF group ERFVII encodes oxygen-labile proteins that are required for oxygen sensing and are stabilized by hypoxia established at the site of Botrytis (Botrytis cinerea) infection. Here, we show that ORA59 represses ERFVII protein activity to induce the expression of hypoxia-responsive genes in Arabidopsis (Arabidopsis thaliana). Moreover, inhibition of ethanol fermentation enhances plant tolerance to Botrytis, indicating a trade-off between the hypoxia and defense responses. In addition, ERFVII members and ORA59 are both involved in the downregulation of hypoxia-responsive genes during reoxygenation. Taken together, our results reveal that the ERFVII transcription factor-ORA59 module ensures that the multiple roles of ERFVII proteins are correctly balanced to favor plant tolerance to biotic or abiotic stresses
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
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