163 research outputs found

    Increased Terpenoid Accumulation in Cotton (Gossypium hirsutum) Foliage is a General Wound Response

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    The subepidermal pigment glands of cotton accumulate a variety of terpenoid products, including monoterpenes, sesquiterpenes, and terpenoid aldehydes that can act as feeding deterrents against a number of insect herbivore species. We compared the effect of herbivory by Spodoptera littoralis caterpillars, mechanical damage by a fabric pattern wheel, and the application of jasmonic acid on levels of the major representatives of the three structural classes of terpenoids in the leaf foliage of 4-week-old Gossypium hirsutum plants. Terpenoid levels increased successively from control to mechanical damage, herbivory, and jasmonic acid treatments, with E-ÎČ-ocimene and heliocide H1 and H4 showing the highest increases, up to 15-fold. Herbivory or mechanical damage to older leaves led to terpenoid increases in younger leaves. Leaf-by-leaf analysis of terpenes and gland density revealed that higher levels of terpenoids were achieved by two mechanisms: (1) increased filling of existing glands with terpenoids and (2) the production of additional glands, which were found to be dependent on damage intensity. As the relative response of individual terpenoids did not differ substantially among herbivore, mechanical damage, and jasmonic acid treatments, the induction of terpenoids in cotton foliage appears to represent a non-specific wound response mediated by jasmonic acid

    Ephemeral Masculinities? Tracking Men, Partners and Fathers in the Geography of Family Holidays

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    The discussion presented in the following pages is anchored in data derived from a broader sociological study into contemporary family rituals. The core argument is that in heterosexual couples, the family–centred holidays presents an opportunity for the everyday gendered division of domestic labour and children care work to be negotiated and temporarily restructured. Through its focus on the role men play in family holidays, this chapter makes an important contribution to debates about masculinity, travel and familial relationships within heterosexual couples. While one needs to be attentive to the complex realities of the modern family life and intra-family relations towards travel and tourism, studying the traditional nuclear family remains an exciting and fruitful work to the extent that one cannot neglect the fact that this model is (still) behind many experiences and representations of families on holidays

    Nucleotide sequence of a Euglena gracilis chloroplast genome region coding for the elongation factor Tu; evidence for a spliced mRNA.

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    We characterize a 1.95 kb transcription product of the Euglena gracilis chloroplast DNA fragment Eco-N + Q by S1 nuclease analysis and DNA sequencing and show that it is the product of three splicing events. Exon 1 (0.45 kb), exon 2 (0.74 kb) and 175 nucleotides of exon 3 (0.53 kb) code for the chloroplast elongation factor protein (EF-Tu). The remaining part of exon 3 and exon 4 (0.23 kb) have unidentified open reading frames. The chloroplast EF-Tu protein has 408 aminoacids and is to 70% homologous with the E. coli EF-Tu protein. The active site for aminoacyl-tRNA binding is highly conserved, while the active site for GTP/GDP binding lacks the cysteine present in the E. coli EF-Tu protein. The two introns separating exons 1, 2 and 3 are, respectively, 103 and 110 nucleotides long. The size of the third intron is not yet determined. The splicing rules for eukaryote mRNA are not followed
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