1,721,243 research outputs found
Strigolactone Biosynthesis and Biology
No full textStrigolactones belong to a newly identified class of plant hormones that are involved in the inhibition of shoot branching. Prior to this finding, strigolactones were proven to be root rhizosphere-signaling molecules that mediate plant–parasitic plant, and the symbiotic plant–AM fungi interactions. More recently, strigolactones were shown to have other biological functions as endogenous plant hormones in shoot development, root architecture, and seed germination (also in nonparasitic plants) and to regulate plant developmental processes in interaction with other signaling pathways (i.e., light and senescence signaling) or hormones. Gene discovery in the strigolactone biosynthesis and signal perception pathways is a key step in elucidating the mechanism and mode of action of the existing roles and discovering potential additional roles of strigolactones. Furthermore, insights into strigolactone and strigolactone-associated pathways will provide more knowledge for the control of parasitic weeds and improvement of crop yield. In this chapter, we outline different aspects of the roles that strigolactones play both in the rhizosphere and during plant development. Gene characterization in strigolactone pathways and strigolactone-related hormone cross-talk is also addressed
Genetic variation in strigolactone production and tillering in rice and its effect on Striga hermonthica infection
Full text linkTillering in cereals is a complex process in the regulation of which also signals from the roots in the form of strigolactones play an important role. The strigolactones are signalling molecules that are secreted into the rhizosphere where they act as germination stimulants for root parasitic plants and hyphal branching factors for arbuscular mycorrhizal fungi. On the other hand, they are also transported from the roots to the shoot where they inhibit tillering or branching. In the present study, the genetic variation in strigolactone production and tillering phenotype was studied in twenty rice varieties collected from all over the world and correlated with S. hermonthica infection. Rice cultivars like IAC 165, IAC 1246, Gangweondo and Kinko produced high amounts of the strigolactones orobanchol, 2'-epi-5-deoxystrigol and three methoxy-5-deoxystrigol isomers and displayed low amounts of tillers. These varieties induced high S. hermonthica germination, attachment, emergence as well as dry biomass. In contrast, rice cultivars such as Super Basmati, TN 1, Anakila and Agee displayed high tillering in combination with low production of the aforementioned strigolactones. These varieties induced only low S. hermonthica germination, attachment, emergence and dry biomass. Statistical analysis across all the varieties confirmed a positive correlation between strigolactone production and S. hermonthica infection and a negative relationship with tillering. These results show that genetic variation in tillering capacity is the result of genetic variation in strigolactone production and hence could be a helpful tool in selecting rice cultivars that are less susceptible to S. hermonthica infection
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
Delvento C, Arcieri F, Marcotrigiano AR, Guerriero M, Fanelli V, Dellino M, Bouwmeester H, Lotti C, Ricciardi L, Pavan S (2023) High-density linkage mapping and genetic dissection of resistance to broomrape (Orobanche crenata Forsk.) in pea (Pisum sativum L.)
No full textPea (Pisum sativum L.) is a widely cultivated legume of major importance
for global food security and agricultural sustainability. Crenate broomrape
(Orobanche crenata Forsk.) (Oc) is a parasitic weed severely affecting
legumes, including pea, in the Mediterranean Basin and the Middle East.
Previously, the identification of the pea line ‘ROR12’, displaying
resistance to Oc, was reported. Two-year field trials on a segregant
population of 148 F7 recombinant inbred lines (RILs), originating from a
cross between ‘ROR12’ and the susceptible cultivar ‘Sprinter’, revealed
high heritability (0.84) of the ‘ROR12’ resistance source. Genotyping-bysequencing
(GBS) on the same RIL population allowed the construction of a
high-density pea linkage map, which was compared with the pea reference
genome and used for quantitative trait loci (QTL) mapping. Three QTLs
associated with the response to Oc infection, named PsOcr-1, PsOcr-2 and
PsOcr-3, were identified, with PsOcr-1 explaining 69.3% of the genotypic
variance. Evaluation of the effects of different genotypic combinations
indicated additivity between PsOcr-1 and PsOcr-2, and between PsOcr-1 and
PsOcr-3, and epistasis between PsOcr-2 and PsOcr-3. Finally, three
Kompetitive Allele Specific PCR (KASP) marker assays were designed on the
single nucleotide polymorphisms (SNPs) associated with the QTL significance
peaks. Besides contributing to the development of pea genomic resources,
this work lays the foundation for the obtainment of pea cultivars resistant
to Oc and the identification of genes involved in resistance to parasitic
Orobanchaceae
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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