Ecological and physiological effects of soil management practices on earthworm communities in French vineyards

International audienceIn recent literature, very few studies have reported the use of the combination of indicators from ecological communities and ecotoxicity biomarkers in field experiments to assess agricultural quality. Therefore, the aim of this study was to determine the influence of three soil management practices of vine inter-rows (chemical weeding, mechanical weeding and grass-covering) on earthworms, in the Gaillac vineyard (South-West France). The sampling, identification and counts of earthworms were performed in spring and autumn over three years in order to determine the influence of the management practices. Focussing on the most abundant species, Aporrectodea nocturna, biomarker assays (glutathione-S-transferase (GST), catalase (CAT) and cholinesterase (ChE) activities) were conducted to check physiological disturbances that are indirectly linked to soil management practices. A strong influence of soil management practices was highlighted on earthworm ecology and physiology in the vine inter-rows. Chemical weeding favoured worm proliferation, but proportionally decreased the number of epi-anecic species. Mechanical weeding dramatically decreased the total number of earthworms, both adults and juveniles, and their biomass. Under these soil farming practices, variations of metabolisation and anti-oxidant enzyme activities were observed, suggesting an increase in pesticide bioavailability. Grass-covering seemed to be the best practice, at least from an environmental point of view. Neurotoxicity enzyme (cholinesterase) activity in vineyard earthworms was not affected by pollutants conventionally sprayed on the vineyard, regardless of soil agricultural practice. It was concluded that soil management practices can both modify earthworm communities and physiology, inducing variations of the following factors: protection against predators, environmental conditions and availability of pesticide and nutrients

Gestion durable du mildiou de la pomme de terre par les métabolites secondaires

Potato late blight disease is a severe phytopathology caused by the oomycete Phytophthora infestans. Since the massive use of synthetic fungicides have harmed both environment and human health for decades, researches must develop new active substances. In that context, plants secondary metabolites such as essential oils seem like a promising and much more sustainable alternative.PHYTOIL : Etudes des modes d'actions d'huiles essentielles sur Phytophthora infestans en vue de la formulations d'un biofongicide permettant de lutter contre le mildiou de la pomme de terr

Mettre à profit l'arsenal des plantes: Les huiles essentielles comme moyen de gestion durable du mildiou de la pomme de terre causé par Phytophthora infestans - Une review

Potato late blight disease is caused by the oomycete Phytophthora infestans and is listed as one of the most severe phytopathologies on Earth. The current environmental issues require new methods of pest management. For that reason, plant secondary metabolites and, in particular, essential oils (EOs) have demonstrated promising potential as pesticide alternatives. This review presents the up-to-date work accomplished using EOs against P. infestans at various experimental scales, from in vitro to in vivo. Additionally, some cellular mechanisms of action on Phytophthora spp., especially towards cell membranes, are also presented for a better understanding of anti-oomycete activities. Finally, some challenges and constraints encountered for the development of EOs-based biopesticides are highlighted

A meta-analysis of the ecotoxicological impact of viticultural practices on soil biodiversity

Viticulture is a key sector of the agricultural economy of the main wine-producing countries, e.g. Italy, France, Spain and the USA, but is also one of the main users of phytosanitary products and mechanization. Over the last 15 years, numerous studies of the effect of viticultural practices on soil quality have evidenced strong impacts on soil physical, chemical and biological quality. However, to date a global analysis providing a comprehensive overview of the ecotoxicological impacts of viticultural practices on soil biological quality is missing. Here, we conducted a meta-analysis of the literature in order to rank viticultural production systems and practices according to their impact on soil biodiversity and functioning in the context of the agro-ecological transition. We screened about one hundred articles and gathered data on more than 50 viticultural factors and 230 soil biological parameters. The results show that soil microorganisms are threefold to fourfold higher under organic viticulture than under conventional viticulture in terms of biomass, respiration and activity; and that biodynamic viticulture shows a similar trend than organic viticulture. Tillage, the absence of soil cover and mineral fertilization are significantly deleterious to the whole soil biodiversity, whereas cover crops, organic fertilizers and addition of grapevine pruning wood are beneficial. Pesticides-especially herbicides-have an ecotoxicological impact on soil organisms, notably on nematodes with losses of up to two-thirds of individuals. The pivotal role of biodiversity in soil functions implies that this degradation will have substantial consequences on the ecological and agronomical services provided by the soil for vine production. On this basis, we propose a potentially more agro-ecological and sustainable vine production system based on the more virtuous practices

Hémodiafiltration en ligne : modalités pratiques, sécurité et efficacité de la méthode

International audienc

Les couverts végétaux. Partie 1/2 : Une pratique agroécologique au service de la vigne

National audienceLes couverts végétaux sont couramment utilisés en tant que cultures intermédiaires, intégrant pleinement les plans de rotation en tant qu’interculture des cultures annuelles (ex. : céréales) et en tant que cultures intercalaires dans le cadre des cultures pérennes (ex. : vergers, vigne). Ce type de culture a fait l’objet de dénominations différentes au cours des dernières décennies comme « engrais vert », en référence à sa contribution à la fertilité des sols, ou « CIPAN » (Culture intermédiaire piège à nitrate) , et dernièrement « CIMS » (Cultures intermédiaires/intercalaires multiservices) (Justes et Richard, 2017). Les plantes de couvert sont cultivées, non pas dans un objectif de production mais dans un objectif de promotion et de valorisation des services écosystémiques au sein de l’exploitation agricole. Parmi ceux-ci, le couvert permet notamment à l’agriculteur de limiter l’impact des intempéries sur ses parcelles, de favoriser les relations trophiques et limiter la pression des ravageurs et des insectes, ou encore de réduire l’utilisation des intrants de synthèse et notamment des herbicides.En viticulture, l’enherbement est pratiqué depuis les années 1990, pour des raisons environnementales et sociétales, mais également avec une volonté d’améliorer la qualité du vin. Cependant, une méconnaissance et une mauvaise gestion de l’enherbement peuvent engendrer une concurrence sur la vigne, qui peut être très préjudiciable en fonction de la fertilité initiale du sol, de la réserve hydrique et de la vigueur du matériel végétal. Il convient donc de bien penser son couvert afin de le réussir et de valoriser les services écosystémiques rendus par celui-ci (encadré 1)

Les couverts végétaux. Partie 2/2 : Les couverts végétaux : engrais verts en viticulture

National audienc

Characterization of a Cell-Assembled extracellular Matrix and the effect of the devitalization process

We have previously shown that the Cell-Assembled extracellular Matrix (CAM) synthesized by normal, human, skin fibroblasts in vitro can be assembled in a completely biological vascular graft that was successfully tested in the clinic. The goal of this study was to perform a detailed analysis of the composition and the organization of this truly bio-material. In addition, we investigated whether the devitalization process (dehydration) used to store the CAM, and thus, make the material available "off-the-shelf," could negatively affect its organization and mechanical properties. We demonstrated that neither the thickness nor the mechanical strength of CAM sheets were significantly changed by the dehydration/freezing/rehydration cycle. The identification of over 50 extracellular matrix proteins highlighted the complex composition of the CAM. Histology showed intense collagen and glycosaminoglycan staining throughout the CAM sheet. The distribution of collagen I, collagen VI, thrombospondin-1, fibronectin-1, fibrillin-1, biglycan, decorin, lumican and versican showed various patterns that were not affected by the devitalization process. Transmission electron microscopy analysis revealed that the remarkably dense collagen network was oriented in the plane of the sheet and that neither fibril density nor diameter was changed by devitalization. Second harmonic generation microscopy revealed an intricate, multi-scale, native-like collagen fiber orientation. In conclusion, this bio-material displayed many tissue-like properties that could support normal cell-ECM interactions and allow implantation without triggering degradative responses from the host's innate immune system. This is consistent with its success in vivo. In addition, the CAM can be devitalized without affecting its mechanical or unique biological architecture. STATEMENT OF SIGNIFICANCE: The extracellular matrix (ECM) defines biological function and mechanical properties of tissues and organs. A number of promising tissue engineering approaches have used processed ECM from cadaver/animal tissues or cell-assembled ECM in vitro combined with scaffolds. We have shown the clinical potential of a scaffold-free approach based on an entirely biological material produced by human cells in culture without chemical processing. Here, we perform a comprehensive analysis of the properties of what can truly be called a bio-material. We also demonstrate that this material can be stored dried without losing its remarkable biological architecture

Human textiles: A cell-synthesized yarn as a truly "bio" material for tissue engineering applications

International audienceIn the field of tissue engineering, many groups have come to rely on the extracellular matrix produced by cells as the scaffold that provides structure and strength to the engineered tissue. We have previously shown that sheets of Cell-Assembled extracellular Matrix (CAM), which are entirely biological yet robust, can be mass-produced for clinical applications using normal, adult, human fibroblasts. In this article, we demonstrate that CAM yarns can be generated with a range of physical and mechanical properties. We show that this material can be used as a simple suture to close a wound or can be assembled into fully biological, human, tissue-engineered vascular grafts (TEVGs) that have high mechanical strength and are implantable. By combining this truly "bio" material with a textile-based assembly, this original tissue engineering approach is highly versatile and can produce a variety of strong human textiles that can be readily integrated in the body. STATEMENT OF SIGNIFICANCE: Yarn of synthetic biomaterials have been turned into textiles for decades because braiding, knitting and weaving machines can mass-produce medical devices with a wide range of shapes and mechanical properties. Here, we show that robust, completely biological, and human yarn can be produced by normal cells in vitro. This yarn can be used as a simple suture material or to produce the first human textiles. For example, we produced a woven tissue-engineered vascular grafts with burst pressure, suture retention strength and transmural permeability that surpassed clinical requirements. This novel strategy holds the promise of a next generation of medical textiles that will be mechanically strong without any foreign scaffolding, and will have the ability to truly integrate into the host's body

A standard for sharing data from vineyard experiments

To facilitate the sharing and interoperability of data collected by many different experimenters and structures, a standardized description of the data acquisition context has been set in the form of a data schema. This data schema defines the entities and the attributes to describe them. This data schema is available online, under an open license CC0 1.0 Universal, with a user’s guide