Anaerobic stress induces the transcription and translation of sucrose synthase in rice

International audienc

Differential induction of pyruvate decarboxylase subunits and transcripts in anoxic rice seedlings

International audienc

Differential induction of pyruvate decarboxylase subunits and transcripts in anoxic rice seedlings

International audienc

Source of Hyalesthes obsoletus Signoret planthopper (Hemiptera: Cixiidae) in southern France and potential effects of landscape

Cixiid planthoppers are considered of major economic importance, as they can transmit phytoplasmas responsible for many plant diseases. While thorougly studied in vineyards, the epidemiology of stolbur phytoplasma, transmitted by Hyalesthes obsoletus Signoret, was rarely investigated on minor crops as lavender, where it leads to ‘yellow decline’ disease and large economic losses. The objective of this paper is to understand the effect of the local landscape characteristics on the presence and density of H. obsoletus in the ‘Plateau de Valensole’, southern France. Potential host plants of H. obsoletus were surveyed in three contrasted zones (in terms of crops and disease intensity), by uprooting plants and capturing adults in emergence traps. The localization and potential movements of H. obsoletus from the host plants towards lavandin (infertile hybrid of lavender) were determined using yellow sticky traps. Clary sage plants were found as major hosts of H. obsoletus. Flying insects were also caught in fields of lavandin, although emergence traps and plant uprooting did not confirm this crop as a winter host, i.e., as a reservoir for the insect. Based on one zone, we showed that attractiveness may depend on crop (clary sage or lavandin) and on its age, as well as on the distance to the supposed source field. These results suggest that clary sage could be an important host of H. obsoletus, whose density largely varies between zones. Genetic studies would be required to confirm the role of clary sage in the dissemination of yellow decline of lavandin

Quick and efficient approach to develop genomic resources in orphan species: Application in Lavandula angustifolia.

Next-Generation Sequencing (NGS) technologies, by reducing the cost and increasing the throughput of sequencing, have opened doors to generate genomic data in a range of previously poorly studied species. In this study, we propose a method for the rapid development of a large-scale molecular resources for orphan species. We studied as an example the true lavender (Lavandula angustifolia Mill.), a perennial sub-shrub plant native from the Mediterranean region and whose essential oil have numerous applications in cosmetics, pharmaceuticals, and alternative medicines. The heterozygous clone "Maillette" was used as a reference for DNA and RNA sequencing. We first built a reference Unigene, compound of coding sequences, thanks to de novo RNA-seq assembly. Then, we reconstructed the complete genes sequences (with introns and exons) using an Unigene-guided DNA-seq assembly approach. This aimed to maximize the possibilities of finding polymorphism between genetically close individuals despite the lack of a reference genome. Finally, we used these resources for SNP mining within a collection of 16 commercial lavender clones and tested the SNP within the scope of a genetic distance analysis. We obtained a cleaned reference of 8, 030 functionally in silico annotated genes. We found 359K polymorphic sites and observed a high SNP frequency (mean of 1 SNP per 90 bp) and a high level of heterozygosity (more than 60% of heterozygous SNP per genotype). On overall, we found similar genetic distances between pairs of clones, which is probably related to the out-crossing nature of the species and the restricted area of cultivation. The proposed method is transferable to other orphan species, requires little bioinformatics resources and can be realized within a year. This is also the first reported large-scale SNP development on Lavandula angustifolia. All the genomics resources developed herein are publicly available and provide a rich pool of molecular resources to explore and exploit lavender genetic diversity in breeding programs

Impact des technologies de conservation des volailles sur la survie et l'adaptation de campylobacter

National audienc

La nationalité dans le monde arabe des années 1830 aux années 1960

La nationalité est devenue une clé d’accès à des droits sociaux, économiques et politiques : marchés du travail, élections, possibilité de se déplacer dans le monde… Du fait de cette centralité dans nos vies contemporaines, la nationalité a surtout suscité pour le monde arabe des études juridiques, de sociologie voire de sciences politiques tandis que l’écriture de son histoire a longtemps été reléguée, éclipsée par celle de la nation, jugée plus fascinante. Dans la lignée de récentes recherches sur la nationalité dans le monde arabe, ce présent dossier propose d’explorer les dimensions historiques de cette notion comme lien légal noué entre des États et des individus. Les études ici réunies permettent de confronter les appréhensions et usages de la nationalité au Maghreb et au Proche Orient, des années 1830 au cours des années 1960, de la fin de l’emprise ottomane aux lendemains des temps coloniaux. Deux premiers articles suivent des trajectoires de vie du second xixe siècle selon les effets et usages du droit de la nationalité. Un second ensemble de contributions se situe à l’échelle des empires ottoman, britannique et français afin d’explorer les capacités d’actions de sujets et de groupes, dans des successions d’États, lorsque des normes juridiques d’appartenance aux États sont transformées ou renégociées. Un troisième et dernier volet explore enfin l’enjeu qu’ont constitué les migrants et la migration pour les États, pour la définition de leur souveraineté et de leurs limites d’action

Cimetières et tombes dans les mondes musulmans

Lieux de mémoire où se conjuguent gestion de l’ici-bas et représentation de l’au-delà, les cimetières et les tombes occupent une place concrète et symbolique considérable dans les mondes musulmans. Porteurs de sens juridiques, éthiques et eschatologiques, rapportés à l’islam comme Loi révélée (sharî‘a), ils font aussi l’objet de décisions politiques, d’appropriations sociales et de pressions économiques diverses. Comme fait social total, ils participent à la construction de la mémoire culturelle de la communauté. Dans cet ouvrage, cimetières et tombes des musulmans sont étudiés à travers les enjeux religieux, politiques et mémoriels que présentent leur habitation, leur gestion et leur fréquentation. Huit contributions analysent ces aspects selon les approches croisées de l’islamologie, de l’anthropologie et des sciences sociales. Après un aperçu des traditions textuelles, des études de cas contemporains couvrent un large spectre géographique, de la Chine au Brésil en passant par le Liban. Le dossier met en lumière la pluralité des statuts et des destins des défunts : saints, héros ou morts ordinaires ; morts en pays d’islam, en terre socialiste ou en émigration. Il montre comment les évolutions sociétales transforment des lieux et des rites apparemment immuables, mais aussi comment des pratiques et croyances perdurent en dépit des aléas politiques. Il établit par là que les cimetières demeurent des lieux vivants où se reflètent et se construisent les sociétés musulmanes

Minor cultures as hosts for vectors of extensive crop diseases: Does Salvia sclarea act as a pathogen and vector reservoir for lavender decline?

Stolbur is a phytoplasma disease affecting crops worldwide. The planthopper Hyalesthes obsoletus is the main natural vector of ‘Candidatus Phytoplasma solani’ responsible of stolbur. In France, lavender (Lavandula angustifolia) and lavandin (Lavandula × intermedia) are strongly affected by this phytoplasma. These plant species are both hosts for the phytoplasma and its insect vector. In 2011, catches of adults were exceptionally sizable on one of the clones of lavandin most tolerant to lavender decline. A high population level of ‘Ca. P. solani’ vector was also observed on the adjacent plot of clary sage, Salvia sclarea. In order to clarify the potential role of S. sclarea as a host plant for H. obsoletus and ‘Ca. P. solani,’ we conducted field surveys and laboratory experiments. The uprooting of clary sage and root examination showed the presence of nymphs during winter. Harvested nymphs have been reared on S. sclarea from seedlings in a greenhouse for many generations. By performing its whole lifecycle on clary sage, we demonstrated for the first time that S. sclarea is a host plant of H. obsoletus and could be a source of stolbur vector. Nevertheless, status of clary sage as host plant of phytoplasma in the field up to now is not so clear. On 42 Q-PCR runs done on S. sclarea, 41 were negative to the phytoplasma, and one positive. Experimental transmission with infected H. obsoletus sampled on infected lavender showed that clary sage plant could be infected, expressed symptoms and multiplied ‘Ca. P. solani.