245 research outputs found

    Envelope Membranes from Spinach Chloroplasts Are a Site of Metabolism of Fatty Acid Hydroperoxides

    Full text link

    “'Subaltern Victims’ or ‘Useful Resources”? Migrant Women in the Lega Nord Ideology and Politics"

    Get PDF
    Since the mid-2000s we have witnessed the emergence of a new phenomenon in several European countries: the mobilisation of issues of women’s rights and gender equality by populist radical right parties (PRR)1 in anti-immigration campaigns. Recent contributions have illustrated some aspects and contradictions of these phenomena, for instance in relation to the PRR parties’ embrace not only of women’s but also gay rights (Bracke 2011). Others have described the double standard applied to migrant men and women in the context of raising hostility towards the Muslim population, not only by PRR parties, but within the mainstream more generally; whereas Muslim men have been mostly described as representing a social and cultural danger to European societies as well as being inherently misogynist, Muslim women have been portrayed prevalently as victims to be rescued (Abu-Lughod 2013). Little however has been written on the gendered ideology and strategies of these parties, particularly when it comes to addressing the issue of migrant women. This chapter aims to address these gaps in the scholarly literature by focusing on the gendered dimensions of anti-immigration ideology, policy and politics in the case of the LN. In particular, we draw on the empirical findings of two research projects to analyse the instrumental mobilisation of women’s rights by the LN to stigmatise migrant, particularly Muslim, communities

    Leukotoxin Diols from Ground Corncob Bedding Disrupt Estrous Cyclicity in Rats and Stimulate MCF-7 Breast Cancer Cell Proliferation

    Get PDF
    Previous studies in our laboratory demonstrated that high-performance liquid chromatography (HPLC) analysis of ground corncob bedding extracts characterized two components (peak I and peak II) that disrupted endocrine function in male and female rats and stimulated breast and prostate cancer cell proliferation in vitro and in vivo. The active substances in peak I were identified as an isomeric mixture of 9,12-oxy-10,13-dihydroxyoctadecanoic acid and 10,13-oxy-9,12-dihydroxyoctadecanoic acid, collectively designated tetrahydrofurandiols (THF-diols). Studies presented here describe the purification and identification of the HPLC peak II component as 9,10-dihydroxy-12-octadecenoic acid (leukotoxin diol; LTX-diol), a well-known leukotoxin. A synthetic mixture of LTX-diol and 12,13-dihydroxy-9-octadecenoic acid (isoleukotoxin diol; i-LTX-diol) isomers was separated by HPLC, and each isomer stimulated (p < 0.001) MCF-7 cell proliferation in an equivalent fashion. The LTX-diol isomers failed to compete for [(3)H]estradiol binding to the estrogen receptor or nuclear type II sites, even though oral administration of very low doses of these compounds (>> 0.8 mg/kg body weight/day) disrupted estrous cyclicity in female rats. The LTX-diols did not disrupt male sexual behavior, suggesting that sex differences exist in response to these endocrine-disruptive agents

    Against Modern Football: Mobilising Protest Movements in Social Media

    Get PDF
    Recent debates in sociology consider how Internet communications might catalyse leaderless, open-ended, affective social movements that broaden support and bypass traditional institutional channels to create change. We extend this work into the field of leisure and lifestyle politics with an empirical study of Internet-mediated protest movement, Stand Against Modern Football. We explain how social media facilitate communications that transcend longstanding rivalries, and engender shared affective frames that unite diverse groups against corporate logics. In examining grassroots organisation, communication and protest actions that span online and urban locations, we discover sustained interconnectedness with traditional social movements, political parties, the media and the corporate targets of protests. Finally, we suggest that Internet-based social movements establish stable forms of organisation and leadership at these networked intersections in order to advance instrumental programmes of change

    Distinct Roles of Jasmonates and Aldehydes in Plant-Defense Responses

    Get PDF
    BACKGROUND: Many inducible plant-defense responses are activated by jasmonates (JAs), C(6)-aldehydes, and their corresponding derivatives, produced by the two main competing branches of the oxylipin pathway, the allene oxide synthase (AOS) and hydroperoxide lyase (HPL) branches, respectively. In addition to competition for substrates, these branch-pathway-derived metabolites have substantial overlap in regulation of gene expression. Past experiments to define the role of C(6)-aldehydes in plant defense responses were biased towards the exogenous application of the synthetic metabolites or the use of genetic manipulation of HPL expression levels in plant genotypes with intact ability to produce the competing AOS-derived metabolites. To uncouple the roles of the C(6)-aldehydes and jasmonates in mediating direct and indirect plant-defense responses, we generated Arabidopsis genotypes lacking either one or both of these metabolites. These genotypes were subsequently challenged with a phloem-feeding insect (aphids: Myzus persicae), an insect herbivore (leafminers: Liriomyza trifolii), and two different necrotrophic fungal pathogens (Botrytis cinerea and Alternaria brassicicola). We also characterized the volatiles emitted by these plants upon aphid infestation or mechanical wounding and identified hexenyl acetate as the predominant compound in these volatile blends. Subsequently, we examined the signaling role of this compound in attracting the parasitoid wasp (Aphidius colemani), a natural enemy of aphids. PRINCIPAL FINDINGS: This study conclusively establishes that jasmonates and C(6)-aldehydes play distinct roles in plant defense responses. The jasmonates are indispensable metabolites in mediating the activation of direct plant-defense responses, whereas the C(6)-aldehyes are not. On the other hand, hexenyl acetate, an acetylated C(6)-aldehyde, is the predominant wound-inducible volatile signal that mediates indirect defense responses by directing tritrophic (plant-herbivore-natural enemy) interactions. SIGNIFICANCE: The data suggest that jasmonates and hexenyl acetate play distinct roles in mediating direct and indirect plant-defense responses. The potential advantage of this "division of labor" is to ensure the most effective defense strategy that minimizes incurred damages at a reduced metabolic cost

    The c4h, tat, hppr and hppd Genes Prompted Engineering of Rosmarinic Acid Biosynthetic Pathway in Salvia miltiorrhiza Hairy Root Cultures

    Get PDF
    Rational engineering to produce biologically active plant compounds has been greatly impeded by our poor understanding of the regulatory and metabolic pathways underlying the biosynthesis of these compounds. Here we capitalized on our previously described gene-to-metabolite network in order to engineer rosmarinic acid (RA) biosynthesis pathway for the production of beneficial RA and lithospermic acid B (LAB) in Salvia miltiorrhiza hairy root cultures. Results showed their production was greatly elevated by (1) overexpression of single gene, including cinnamic acid 4-hydroxylase (c4h), tyrosine aminotransferase (tat), and 4-hydroxyphenylpyruvate reductase (hppr), (2) overexpression of both tat and hppr, and (3) suppression of 4-hydroxyphenylpyruvate dioxygenase (hppd). Co-expression of tat/hppr produced the most abundant RA (906 mg/liter) and LAB (992 mg/liter), which were 4.3 and 3.2-fold more than in their wild-type (wt) counterparts respectively. And the value of RA concentration was also higher than that reported before, that produced by means of nutrient medium optimization or elicitor treatment. It is the first report of boosting RA and LAB biosynthesis through genetic manipulation, providing an effective approach for their large-scale commercial production by using hairy root culture systems as bioreactors

    Cloning and characterization of a 9-lipoxygenase gene induced by pathogen attack from Nicotiana benthamiana for biotechnological application

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Plant lipoxygenases (LOXs) have been proposed to form biologically active compounds both during normal developmental stages such as germination or growth as well as during responses to environmental stress such as wounding or pathogen attack. In our previous study, we found that enzyme activity of endogenous 9-LOX in <it>Nicotiana benthamiana </it>was highly induced by agroinfiltration using a tobacco mosaic virus (TMV) based vector system.</p> <p>Results</p> <p>A <it>LOX </it>gene which is expressed after treatment of the viral vectors was isolated from <it>Nicotiana benthamiana</it>. As the encoded LOX has a high amino acid identity to other 9-LOX proteins, the gene was named as <it>Nb-9-LOX</it>. It was heterologously expressed in yeast cells and its enzymatic activity was characterized. The yeast cells expressed large quantities of stable 9-LOX (0.9 U ml<sup>-1 </sup>cell cultures) which can oxygenate linoleic acid resulting in high yields (18 μmol ml<sup>-1 </sup>cell cultures) of hydroperoxy fatty acid. The product specificity of Nb-9-LOX was examined by incubation of linoleic acid and Nb-9-LOX in combination with a 13-hydroperoxide lyase from watermelon (Cl-13-HPL) or a 9/13-hydroperoxide lyase from melon (Cm-9/13-HPL) and by LC-MS analysis. The result showed that Nb-9-LOX possesses both 9- and 13-LOX specificity, with high predominance for the 9-LOX function. The combination of recombinant Nb-9-LOX and recombinant Cm-9/13-HPL produced large amounts of C<sub>9</sub>-aldehydes (3.3 μmol mg<sup>-1 </sup>crude protein). The yield of C<sub>9</sub>-aldehydes from linoleic acid was 64%.</p> <p>Conclusion</p> <p>The yeast expressed Nb-9-LOX can be used to produce C<sub>9</sub>-aldehydes on a large scale in combination with a <it>HPL </it>gene with 9-HPL function, or to effectively produce 9-hydroxy-10(<it>E</it>),12(<it>Z</it>)-octadecadienoic acid in a biocatalytic process in combination with cysteine as a mild reducing agent.</p

    Transcriptome Analysis of H2O2-Treated Wheat Seedlings Reveals a H2O2-Responsive Fatty Acid Desaturase Gene Participating in Powdery Mildew Resistance

    Get PDF
    Hydrogen peroxide (H2O2) plays important roles in plant biotic and abiotic stress responses. However, the effect of H2O2 stress on the bread wheat transcriptome is still lacking. To investigate the cellular and metabolic responses triggered by H2O2, we performed an mRNA tag analysis of wheat seedlings under 10 mM H2O2 treatment for 6 hour in one powdery mildew (PM) resistant (PmA) and two susceptible (Cha and Han) lines. In total, 6,156, 6,875 and 3,276 transcripts were found to be differentially expressed in PmA, Han and Cha respectively. Among them, 260 genes exhibited consistent expression patterns in all three wheat lines and may represent a subset of basal H2O2 responsive genes that were associated with cell defense, signal transduction, photosynthesis, carbohydrate metabolism, lipid metabolism, redox homeostasis, and transport. Among genes specific to PmA, ‘transport’ activity was significantly enriched in Gene Ontology analysis. MapMan classification showed that, while both up- and down- regulations were observed for auxin, abscisic acid, and brassinolides signaling genes, the jasmonic acid and ethylene signaling pathway genes were all up-regulated, suggesting H2O2-enhanced JA/Et functions in PmA. To further study whether any of these genes were involved in wheat PM response, 19 H2O2-responsive putative defense related genes were assayed in wheat seedlings infected with Blumeria graminis f. sp. tritici (Bgt). Eight of these genes were found to be co-regulated by H2O2 and Bgt, among which a fatty acid desaturase gene TaFAD was then confirmed by virus induced gene silencing (VIGS) to be required for the PM resistance. Together, our data presents the first global picture of the wheat transcriptome under H2O2 stress and uncovers potential links between H2O2 and Bgt responses, hence providing important candidate genes for the PM resistance in wheat
    corecore