The willow microbiome is influenced by soil petroleum-hydrocarbon concentration with plant compartment-specific effects

International audienceThe interaction between plants and microorganisms, which is the driving force behind the decontamination of petroleum hydrocarbon (PHC) contamination in phytoremediation technology, is poorly understood. Here, we aimed at characterizing the variations between plant compartments in the microbiome of two willow cultivars growing in contaminated soils. A field experiment was set-up at a former petrochemical plant in Canada and after two growing seasons, bulk soil, rhizosphere soil, roots, and stems samples of two willow cultivars (Salix purpurea cv. FishCreek, and Salix miyabeana cv. SX67) growing at three PHC contamination concentrations were taken. DNA was extracted and bacterial 16S rRNA gene and fungal internal transcribed spacer (ITS) regions were amplified and sequenced using an Ion Torrent Personal Genome Machine (PGM). Following multivariate statistical analyses, the level of PHC-contamination appeared as the primary factor influencing the willow microbiome with compartment-specific effects, with significant differences between the responses of bacterial, and fungal communities. Increasing PHC contamination levels resulted in shifts in the microbiome composition, favoring putative hydrocarbon degraders, and microorganisms previously reported as associated with plant health. These shifts were less drastic in the rhizosphere, root, and stem tissues as compared to bulk soil, probably because the willows provided a more controlled environment, and thus, protected microbial communities against increasing contamination levels. Insights from this study will help to devise optimal plant microbiomes for increasing the efficiency of phytoremediation technology

Origin and Evolution of TRIM Proteins: New Insights from the Complete TRIM Repertoire of Zebrafish and Pufferfish

Tripartite motif proteins (TRIM) constitute a large family of proteins containing a RING-Bbox-Coiled Coil motif followed by different C-terminal domains. Involved in ubiquitination, TRIM proteins participate in many cellular processes including antiviral immunity. The TRIM family is ancient and has been greatly diversified in vertebrates and especially in fish. We analyzed the complete sets of trim genes of the large zebrafish genome and of the compact pufferfish genome. Both contain three large multigene subsets - adding the hsl5/trim35-like genes (hltr) to the ftr and the btr that we previously described - all containing a B30.2 domain that evolved under positive selection. These subsets are conserved among teleosts. By contrast, most human trim genes of the other classes have only one or two orthologues in fish. Loss or gain of C-terminal exons generated proteins with different domain organizations; either by the deletion of the ancestral domain or, remarkably, by the acquisition of a new C-terminal domain. Our survey of fish trim genes in fish identifies subsets with different evolutionary dynamics. trims encoding RBCC-B30.2 proteins show the same evolutionary trends in fish and tetrapods: they evolve fast, often under positive selection, and they duplicate to create multigenic families. We could identify new combinations of domains, which epitomize how new trim classes appear by domain insertion or exon shuffling. Notably, we found that a cyclophilin-A domain replaces the B30.2 domain of a zebrafish fintrim gene, as reported in the macaque and owl monkey antiretroviral TRIM5α. Finally, trim genes encoding RBCC-B30.2 proteins are preferentially located in the vicinity of MHC or MHC gene paralogues, which suggests that such trim genes may have been part of the ancestral MHC

’Urbs, ’urb girls and Martine Delvaux’s Rose amer

This article considers representations of exurban spaces in Martine Delvaux’s Rose amer (2009), positioning it in relation to a broader take-up of “regional” spaces in Québec fiction. It argues that Delvaux’s novel is prescient in its blurring of distinct spatial categories. Examining how Rose amer parallels setting and characters, the article argues that it offers an intervention in the politics of memorialization. This is achieved through a focus on the standardized and reproducible, so that the vernacular domestic geographies featured within the novel become everyday monuments to the violence which is daily perpetrated against girls and women. Novelist, essayist, and public intellectual, Martine Delvaux is known for her literary and theoretical engagement with feminism. Not surprisingly, critics tend to focus on the identity politics within her work (Montpetit 2009; Tardif 2017). However, the author is an evocative place-writer. As Chantal Guy points out in a review of Les Cascadeurs de l’amour n’ont pas droit au doublage (Delvaux 2012a), “les lieux, dans les romans de Martine Delvaux […], sont importants” (Guy 2012). In this article, I shall examine how gender and literary geographies come together to particular effect in Delvaux’s Rose amer (Delvaux 2009a), translated into English by David Homel as Bitter Rose (2015a). The novel traces the social mores of white- and blue-collar Québec and Franco-Ontario during the 1970s and 1980s. Its taking up of themes like single-motherhood, domestic labor, and sexual violence is combined with a depiction of everyday middle- and lower-middle-class life in accommodation such as the bungalow and row house. Rose amer can be positioned in relation to broader trends in French-language fiction from Québec, in that, with the exception of the opening section, it is set outside Montréal. The city has tended to dominate Québec prose writing in both of the province’s majority languages since the 1940s, especially since the nationalist assertion of the 1960s known as the Quiet Revolution. However, the last 20 years have seen a growing body of new regional writing in French. In what follows, I propose that the settings of significant parts of Rose amer can be read as inscriptions of what I term “’urb-anization.” As outlined in the introduction to this dossier, ’urbanization is fostered by global communications technologies and the expansion of housing forms in locations which are not quite rural and not quite urban, but various combinations of both. In claiming that Delvaux’s novel mediates this phenomenon, I demonstrate how places within Rose amer have their parallels in fictional characters. Drawing on Delvaux’s concept of “les filles en série” (Delvaux 2013), I argue that the girls in the novel function as individuals and a collective: given identities of their own, they can nevertheless seem to merge into one. Similarly, the village and suburb are distinctive and everyplaces, offering a model of ’urban life which carries an affective charge like those found in other examples of Québec culture of the period, such as Arcade Fire’s smash nostalgia-fest, The Suburbs (2010). There is a tension in Rose amer, however, between affection and an unease at the gendered violence tacitly underlying everyday routines, which ensures that girls are out of place within the domestic landscapes they inhabit. As a consequence, these landscapes become not only emblems of particular moments in North American housing developments, but also monuments to girls’ and women’s unseen pain