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2017, Publications.


  • Aguié-Beghin V, Paës G, Molinari M, Chabbert B. Films and coatings from lignocellulosic polymers. Edible Films and Coatings: Fundamentals and Applications 2017.!ConsultNotice:392787 (consulté 24 nov.2017).

  • Azzi J, Danjou P-E, Landy D, et al. The effect of cyclodextrin complexation on the solubility and photostability of nerolidol as pure compound and as main constituent of cabreuva essential oil. Beilstein Journal of Organic Chemistry 2017; 13: 835-844.
    Résumé : Beilstein Journal of Organic Chemistry

  • Blanc C-L, Lemaire J, Duval F, Théoleyre M-A, Pareau D. Purification of pentoses from hemicellulosic hydrolysates without neutralization for sulfuric acid recovery. Separation and Purification Technology 2017; 174: 513-519.
    Résumé : The agro-industrial sector generates large amounts of coproducts such as lignocellulosic biomass which could be valorized into many chemicals and bio-based intermediates (sugars, paper pulp, surfactants, polymers or bioethanol). However, in the case of biomass hydrolysis by diluted sulfuric acid, current downstream processes involve a partial or complete neutralization which are not satisfactory for economic and environmental reasons. This work presents a purification process of pentoses from hemicellulosic hydrolysates without neutralization for sulfuric acid recovery. Compared to conventional processes, less energy, water and chemicals are required. Very promising results were obtained at pilot scale with 100L of wheat bran hydrolysates. The process is based on the combination of ultrafiltration, conventional electrodialysis and ion-exchange. Ultrafiltration with a 10kDa organic membrane totally removed harmful macromolecules which precipitate during electrodialysis operation because of pH rise. Till a volumetric concentration factor 3.6, the average flux kept good for industrial application (27L·h−1·m−2). However suspended materials have to be filtered before ultrafiltration. Besides, a 2.5 diafiltration is required to recover most of sugars (99%). Then conventional electrodialysis was performed to recover most of sulfuric acid (80%). The average faradic yield was quite good (80%) and the specific energy consumption of the electrodialysis stack was quite interesting (1.1kWh per kg of H2SO4 recovered and 8.4kWh per m3 of hydrolysate). Finally, the complete demineralization (conductivity<10μS·cm−1) and discoloration (420nm absorbance<0.01) of the sugars solution was performed by ion-exchange and an activated carbon polishing treatment. The sugars purity was close to 100% meanwhile the overall sugars recovery rate reach about 90%. Finally we checked that the reused sulfuric acid solution was as efficient as a fresh one in a second hydrolysis operation of wheat bran. Recovery rates could be increased by a scale-up operation or a continuous mode of the process.
    Mots-clés : Acid recycling, Electrodialysis, Green chemistry, Pentoses, Purification.

  • Boisson S, Faucon M-P, Le Stradic S, et al. Specialized edaphic niches of threatened copper endemic plant species in the D.R. Congo: implications for ex situ conservation. Plant and soil 2017; 413: 261-273.
    Résumé : Background and aimsCopper (Cu) rich soils derived from rocks of the Katangan Copperbelt in the south-eastern Democratic Republic of Congo (DRC) support a rich diversity of metallophytes including 550 heavy metal tolerant; 24 broad Cu soil endemic; and 33 strict Cu soil endemic plant species. The majority of the plant species occur on prominent Cu hills scattered along the copperbelt. Heavy metal mining on the Katangan Copperbelt has resulted in extensive degradation and destruction of the Cu hill ecosystems. As a result, approximately 80 % of the strict Cu endemic plant species are classified as threatened according to IUCN criteria and represent a conservation priority. Little is known about the soil Cu tolerance optimum of the Cu endemic plant species. The purpose of this study was to quantify the soil Cu concentration (Cu edaphic niche) of four Cu endemic plant species to inform soil propagation conditions and microhabitat site selection for planting of the species in Cu hill ecosystem restoration.MethodsThe soil Cu concentration tolerance of Cu endemic plant species was studied including Crotalaria cobalticola (CRCO); Gladiolus ledoctei (GLLE); Diplolophium marthozianum (DIMA); and Triumfetta welwitschii var. rogersii (TRWE-RO). The in situ natural habitat distributions of the Cu endemic plant species with respect to soil Cu concentration (Cu edaphic niche) was calculated by means of a generalised additive model. Additionally, the seedling emergence and growth of the four Cu endemic plant species in three soil Cu concentrations was tested ex situ and the results were compared to that of the natural habitat soil Cu concentration optimum (Cu edaphic niche).ResultsCRCO exhibited greater performance on the highest soil Cu concentration, consistent with its calculated Cu edaphic niche occurring at the highest soil Cu concentrations. In contrast, both DIMA and TRWE-RO exhibited greatest performance at the lowest soil Cu concentration, despite the calculated Cu edaphic niche occurring at moderate soil Cu concentrations. GLLE exhibited equal performances in the entire range of soil Cu concentrations.ConclusionsThese results suggest that CRCO evolved via the edaphic specialization model where it is most competitive in Cu hill habitat with the highest soil Cu concentration. In comparison, DIMA and TRWE-RO appear to have evolved via the endemism refuge model, which indicates that the species were excluded into (i.e., took refuge in) the lower plant competition Cu hill habitat due to their inability to effectively compete with higher plant competition on normal soils. The soil Cu edaphic niche determined for the four species will be useful in conservation activities including informing soil propagation conditions and microhabitat site selection for planting of the species in Cu hill ecosystem restoration.

  • Bourdot A, Moussa T, Gacoin A, et al. Characterization of a hemp-based agro-material: Influence of starch ratio and hemp shive size on physical, mechanical, and hygrothermal properties. Energy and Buildings 2017; 153: 501-512.
    Résumé : Hemp shives is a lightweight material known for its insulating properties. Associating these bio-fibers with plant-based matrix instead of a mineral binder in insulation applications is of ecological interest. This article describes the study of a low environmental impact 100% plant-based material made solely from wheat starch and hemp shives. The hemp/starch ratio (H/S) influence and hemp shive size are studied. Samples are evaluated in terms of physical properties, mechanical behaviour and hygrothermal properties through an experimental approach. Results show that increasing 0–5mm hemp shive proportion from 15% to 30% leads to a significant enhancement of the mechanical and hygric characteristics due to the load transfer and porosity. However, when the H/S ratio increases, mechanical and hygrothermal characteristics decrease slightly. Finally, the hemp-starch agro-material with H/S equal to 8 and 30% of 0–5mm hemp shive seems to be the optimal composition between the studied samples.
    Mots-clés : Hemp starch agro-material, Hygric properties, Mechanical properties, Porosity, Thermal properties.

  • Brahim M, Checa Fernandez BL, Regnier O, et al. Impact of ultrasounds and high voltage electrical discharges on physico-chemical properties of rapeseed straw’s lignin and pulps. Bioresource Technology 2017; 237: 11-19.
    Résumé : In this study, ultrasound (US) and high voltage electrical discharges (HVED) were combined with chemical treatments (soda or organosolv) for rapeseed straw delignification. Delignification was improved by both physical pretreatments. US increased the extractability of hemicelluloses and HVED induced a partial degradation of cellulose. Best synergies were observed for HVED-soda and US-organosolv treatments. The obtained lignin fractions were characterized with 13C NMR and 2D 1H–13C HSQC. It was observed that the physical treatments affected the syringyl/guaiacyl (S/G) ratios. The values of S/G were ≈1.19, 1.31 and 1.75 for organosolv, HVED-organosolv and US-organosolv processes, suggesting recondensation reactions. The lignin fractions obtained from HVED-organosolv treatment contained less quantity of p-coumaric acid and ferulic acid as compared to those extracted by US-organosolv. Thermogravimetric analysis (TGA) revealed a better heat resistance of physically extracted lignins as compared to the control. The enzymatic digestibility increased by 24.92% when applying HVED to mild organosolv treatment.
    Mots-clés : Delignification, High voltage electrical discharges, Organosolv, Soda, Ultrasound.

  • Comby M, Mustafa G, Magnin-Robert M, et al. Arbuscular Mycorrhizal Fungi as Potential Bioprotectants Against Aerial Phytopathogens and Pests. Arbuscular Mycorrhizas and Stress Tolerance of Plants 2017; : 195-223.
    Résumé : In the context of an increasing worldwide food requirement, the control of crop diseases is crucial to guarantee high and stable yield, as well as sanitary quality. An environmentally friendly contribution to this could be biocontrol using beneficial microorganisms, such as arbuscular mycorrhizal fungi (AMF). AMF establish symbiosis with their host plants, thus influencing their growth, but they also induce tolerance to environmental stresses. Among stresses that can be alleviated through AMF inoculation, plant attacks by aerial pathogens and pests have so far been underestimated. Therefore, we present here an overview of studies focusing on AMF-mediated bioprotection against aerial pathogens and pests. Obtained protection is mainly due to changes in host nutrition and induction of defense following the establishment of arbuscular mycorrhizal symbiosis. This protection can vary greatly depending on different factors such as host genotype, AMF species involved, pest and pathogen lifestyles, interactions between AMF and other microorganisms, or even crop management practices. Finally, some future challenges for the use of AMF in biocontrol are discussed.
    Mots-clés : Aerial pests, Aerial phytopathogens, Arbuscular mycorrhizal fungi, Biocontrol, Mycorrhiza-induced resistance.

  • Dupoiron S, Lameloise M-L, Pommet M, et al. A novel and integrative process: From enzymatic fractionation of wheat bran with a hemicellulasic cocktail to the recovery of ferulic acid by weak anion exchange resin. Industrial Crops and Products 2017; 105: 148-155.
    Résumé : An integrated and eco-friendly process including enzymatic hydrolysis with a hemicellulasic cocktail and a chromatographic purification step was developed to obtain ferulic acid from wheat bran. Thermobacillus xylanilyticus, a thermophilic and hemicellulolytic bacterium, was able to produce enzymatic cocktails containing xylanase, xylosidase, arabinosidase and esterase activities. The cocktails produced were used to deconstruct destarched wheat bran, allowing the release of 6%, 20% and 37% (w/w) of monomeric arabinose, xylose and ferulic acid, respectively. A weak anionic resin under free-base form was proved successful to separate the carbohydrate fraction from the ferulate one after acidification. Ferulate was recovered at high concentration (15g/L) during regeneration of the resin. This non-optimized purification step allowed recovering 67% of ferulic acid fixed on the resin. Global recovery of ferulic acid contained in wheat bran after both enzymatic fractionation and purification stages reached 21.8%.
    Mots-clés : Biorefinery, Ferulic acid, Weak anionic resin, Xylans.

  • Fougerit V, Pozzobon V, Pareau D, Théoleyre M-A, Stambouli M. Gas-liquid absorption in industrial cross-flow membrane contactors: Experimental and numerical investigation of the influence of transmembrane pressure on partial wetting - ScienceDirect. 2017. doi:
    Résumé : Membrane wetting is a limitation to mass transfer in industrial Hollow-Fiber Membrane Modules (HFMM). The influence of transmembrane pressure on wetting is investigated through both experimental and numerical works. On the one hand, experiments for CO2 absorption in softened water are carried out at pilot scale with Liqui-Cel® Extra-Flow modules operating in a cross-flow mode. After several hours of operation (50–300 min), the membrane partially wetted mode is established at steady state and decreases the absorbed CO2 flowrates up to 10.5% compared to membrane dry mode. Interestingly, CO2 absorption is found to be independent on different transmembrane pressure (0.5 and 2.5 bar), both in the dry and partially wetted mode. On the other hand, a 2D predictive tool is developed to help in the design of HFMM gas absorption systems. The model depicts the complex hydrodynamics in commercial cross-flow modules. The liquid in the shellside is flowing through the fiber bundle considered as a porous medium. The liquid mass-transfer coefficient is non-uniform over the membrane module and is estimated at a local scale. The parameters from the empirical Chilton-Colburn correlation are optimized with experimental results in the dry mode through a Particle Swarm Optimization (PSO) algorithm. The simulation results are in good agreement with the experiments (−13/+17%). In the partially wetted mode at steady state, wetting is then described by considering a log-normal pore size distribution and the Laplace-Young equation. The transmembrane pressure decreases the simulated absorbed CO2 flowrate. By comparing to experimental data, the numerical relative error is increasing with transmembrane pressure. Therefore, a suggestion is made to adapt the description of wetting in HFMM gas-liquid models.

  • Gallos A, Paës G, Allais F, Beaugrand J. Lignocellulosic fibers: a critical review of the extrusion process for enhancement of the properties of natural fiber composites. RSC Advances 2017; 7: 34638-34654.
    Résumé : Natural fiber composites have various applications, since they can bring interesting mechanical and sustainability properties. Extrusion with a single- or twin-screw is the main industrial process to incorporate lignocellulosic fibers into polymers. In this review, the origin and preparation of lignocellulosic fibers are first presented, before discussing the composite processing, with a particular emphasis on the impact of process conditions on the composites final properties that is highly related to the final application. A broad panel of composites reinforced with lignocellulosic fibers is reviewed along with their polymeric matrix, lignocellulosic fiber type and pretreatments, and extrusion process conditions. Finally, the most critical extrusion process parameters (screw profile, speed and temperature) are also examined in order to determine some guidelines to optimize lignocellulosic fiber composites preparation.

  • Gallos A, Paës G, Legland D, Allais F, Beaugrand J. Exploring the microstructure of natural fibre composites by confocal Raman imaging and image analysis. Composites Part A: Applied Science and Manufacturing 2017; 94: 32-40.
    Résumé : We describe a combination of Confocal Raman Imaging (CRI) and quantitative image analysis to characterise biocomposite material microstructures. Both techniques offer lateral resolutions close to 1.3μm and axial resolution of 13μm, while simplifying sample preparation to hand-cutting without any surface preparation. Extruded and injected polycaprolactone/hemp fibre composites were used as demonstration biocomposites. A green macrobisphenol additive (bis-O-dihydroferuloyl-1,4-butanediol) was also used as a chemical probe to characterise the dispersion efficiency of additives, with a detection threshold of 2.3wt% above which very local heterogeneity can be determined by this technique. CRI provided microstructure information for the entire binary structure formed by the fibre network. The fibre dispersion and orientation depend on their location in the matrix, and the specific surface of the fibres increases with the fibre content as aggregates start to develop. The technique also highlighted a possible core-skin effect in the injected composite.
    Mots-clés : A. Natural fibre, B. Microstructure, C. Numerical analysis, D. Surface analysis.

  • Gallos A, Paës G, Legland D, Beaugrand J, Allais F. A microstructural and chemical approach to highlight how a simple methyl group affects the mechanical properties of a natural fibers composite. ACS Sustainable Chemistry & Engineering 2017. doi:10.1021/acssuschemeng.7b02399.
    Résumé : Two ferulic acid derivatives (BDF and BDF-Me) were prepared using chemo-enzymatic synthesis and used as additives for the pretreatment of hemp fibers. Incorporation of these fibers into a polycaprolactone matrix by hot-melt extrusion process aimed to improve the dispersion of the fibers and the mechanical properties of the resulting materials. Young's modulus and tensile strength of the composites were investigated at the micrometer scale by chemical imaging. The very simple methylation of the phenolic functions led to significant mechanical properties differences due to the dispersion of the fibers caused by a plasticizing effect of the ferulic acid derivative. This significant plasticizing effect of BDF-Me is observed at a content as low as 0.8 w% and opens the way for synthesizing a new family of biobased plasticizers involving transition from crystal state to amorphous phase.

  • Guénin S, Hardouin J, Paynel F, et al. AtPME3, a ubiquitous cell wall pectin methylesterase of Arabidopsis thaliana, alters the metabolism of cruciferin seed storage proteins during post-germinative growth of seedlings. Journal of Experimental Botany 2017; 68: 1083-1095.
    Résumé : AtPME3 (At3g14310) is a ubiquitous cell wall pectin methylesterase. Atpme3-1 loss-of-function mutants exhibited distinct phenotypes from the wild type (WT), and were characterized by earlier germination and reduction of root hair production. These phenotypical traits were correlated with the accumulation of a 21.5-kDa protein in the different organs of 4-day-old Atpme3-1 seedlings grown in the dark, as well as in 6-week-old mutant plants. Microarray analysis showed significant down-regulation of the genes encoding several pectin-degrading enzymes and enzymes involved in lipid and protein metabolism in the hypocotyl of 4-day-old dark grown mutant seedlings. Accordingly, there was a decrease in proteolytic activity of the mutant as compared with the WT. Among the genes specifying seed storage proteins, two encoding CRUCIFERINS were up-regulated. Additional analysis by RT-qPCR showed an overexpression of four CRUCIFERIN genes in the mutant Atpme3-1, in which precursors of the α- and β-subunits of CRUCIFERIN accumulated. Together, these results provide evidence for a link between AtPME3, present in the cell wall, and CRUCIFERIN metabolism that occurs in vacuoles.
    Mots-clés : Arabidopsis, AtPME3, CRUCIFERIN, etiolated hypocotyl, seed germination, transcriptomic analyses..

  • Hano C, Corbin C, Drouet S, et al. The lignan (+)-secoisolariciresinol extracted from flax hulls is an effective protectant of linseed oil and its emulsion against oxidative damage. European Journal of Lipid Science and Technology 2017. doi:10.1002/ejlt.201600219.
    Résumé : Secoisolariciresinol (SECO) is a natural antioxidant lignan accumulated in large amounts in the seedcoat of flax and retained in the flaxseed cake residue during linseed oil pressing. Here SECO was extracted and purified from flaxseed cake and assayed for its ability to prevent oxidation of linseed oil and an o/w emulsion containing linseed oil. For this purpose, an accelerated storage (Schaal oven) test was performed and SECO effectiveness was compared to that of two antioxidants commonly used in food and cosmetic products: α-tocopherol (α-TOCO) and butylated hydroxyanisole (BHA). In our hands, SECO addition, ranging from 50 to 500 μmole per kg oil, significantly decreased the production of both primary (conjugated dienes, CD) and secondary (thiobarbituric acid-reactive substances, TBARS) oxidation products. This study evidenced that SECO is an effective stabilizer of linseed oil and its o/w emulsion and this protective effect outperformed both the natural α-TOCO and the synthetic BHA antioxidants. In particular, SECO was the most effective in the protection of the o/w emulsion against secondary oxidation products, which makes it a potential alternative preservative for oily products in foods and cosmetics. Practical applications: The present study could lead to applications in the food and cosmetic industries for the stabilization of o/w emulsions. Addition of SECO to linseed oil, already rich in ω-3, could also result in a new functional food with synergistic beneficial actions on human health.

  • Hardy B, Cornelis J-T, Houben D, Leifeld J, Lambert R, Dufey J. Evaluation of the long-term effect of biochar on properties of temperate agricultural soil at pre-industrial charcoal kiln sites in Wallonia, Belgium. European Journal of Soil Science 2017; 68. doi:10.1111/ejss.12395.
    Résumé : Research on biochar has increased, but its long-term effect on the fertility of temperate agricultural soil remains unclear. In Wallonia, Belgium, pre-industrial charcoal production affected former forested areas that were cleared for cultivation in the nineteenth century. The sites of traditional charcoal kilns, largely enriched in charcoal residues, are similar to soil amended with hardwood biochar more than 150 years ago. We sampled 17 charcoal kiln sites to characterize their effect on soil properties compared with adjacent reference soils. Charcoal-C content was estimated by differential scanning calorimetry. The kiln soil contains from 1.8 to 33.1 g kg−1 of charcoal-C, which markedly increases organic C:N and C:P ratios. It also contains slightly more uncharred soil organic carbon (SOC) than the reference soil, which accords with larger total N content. We measured a small increase in nitrates in the kiln soil that might relate to greater mineralization and nitrification of organic N. Frequent application of lime raised the pH to values close to neutral, which offset the residual effect of charcoal production on soil acidity. A cation exchange capacity (CEC) of 414 cmolc kg−1 was estimated for charcoal-C, whereas that of uncharred SOC was 213 cmolc kg−1. Despite the large CEC of the kiln soil, exchangeable K+ content was no different from the adjacent soil, whereas exchangeable Ca2+ and Mg2+ contents were considerably larger. Charcoal enrichment has little effect on available, inorganic and total P, but it can form strong complexes with Cu, which reduces the availability of the metal. Biochar is very persistent in soil; therefore, long-term implications should not be overlooked.

  • Hocq L, Sénéchal F, Lefebvre V, et al. Combined Experimental and Computational Approaches Reveal Distinct pH Dependence of Pectin Methylesterase Inhibitors. Plant Physiology 2017; 173: 1075-1093.
    Résumé : The fine-tuning of the degree of methylesterification of cell wall pectin is a key to regulating cell elongation and ultimately the shape of the plant body. Pectin methylesterification is spatiotemporally controlled by pectin methylesterases (PMEs; 66 members in Arabidopsis [Arabidopsis thaliana]). The comparably large number of proteinaceous pectin methylesterase inhibitors (PMEIs; 76 members in Arabidopsis) questions the specificity of the PME-PMEI interaction and the functional role of such abundance. To understand the difference, or redundancy, between PMEIs, we used molecular dynamics (MD) simulations to predict the behavior of two PMEIs that are coexpressed and have distinct effects on plant development: AtPMEI4 and AtPMEI9. Simulations revealed the structural determinants of the pH dependence for the interaction of these inhibitors with AtPME3, a major PME expressed in roots. Key residues that are likely to play a role in the pH dependence were identified. The predictions obtained from MD simulations were confirmed in vitro, showing that AtPMEI9 is a stronger, less pH-independent inhibitor compared with AtPMEI4. Using pollen tubes as a developmental model, we showed that these biochemical differences have a biological significance. Application of purified proteins at pH ranges in which PMEI inhibition differed between AtPMEI4 and AtPMEI9 had distinct consequences on pollen tube elongation. Therefore, MD simulations have proven to be a powerful tool to predict functional diversity between PMEIs, allowing the discovery of a strategy that may be used by PMEIs to inhibit PMEs in different microenvironmental conditions and paving the way to identify the specific role of PMEI diversity in muro.
    Mots-clés : Arabidopsis, Arabidopsis Proteins, Carboxylic Ester Hydrolases, Cell Wall, Computational Biology, Enzyme Inhibitors, Escherichia coli, Gene Expression Regulation, Plant, Germination, Hydrogen Bonding, Hydrogen-Ion Concentration, Hypocotyl, Molecular Dynamics Simulation, Plant Roots, Pollen Tube, Recombinant Proteins.

  • Hodroge A, Trécherel E, Cornu M, et al. Oligogalacturonic Acid Inhibits Vascular Calcification by Two Mechanisms: Inhibition of Vascular Smooth Muscle Cell Osteogenic Conversion and Interaction With Collagen. Arteriosclerosis, Thrombosis, and Vascular Biology 2017; 37: 1391-1401.
    Résumé : OBJECTIVE: Cardiovascular diseases constitute the leading cause of mortality worldwide. Calcification of the vessel wall is associated with cardiovascular morbidity and mortality in patients having many diseases, including diabetes mellitus, atherosclerosis, and chronic kidney disease. Vascular calcification is actively regulated by inductive and inhibitory mechanisms (including vascular smooth muscle cell adaptation) and results from an active osteogenic process. During the calcification process, extracellular vesicles (also known as matrix vesicles) released by vascular smooth muscle cells interact with type I collagen and then act as nucleating foci for calcium crystallization. Our primary objective was to identify new, natural molecules that inhibit the vascular calcification process. APPROACH AND RESULTS: We have found that oligogalacturonic acids (obtained by the acid hydrolysis of polygalacturonic acid) reduce in vitro inorganic phosphate-induced calcification of vascular smooth muscle cells by 80% and inorganic phosphate-induced calcification of isolated rat aortic rings by 50%. A specific oligogalacturonic acid with a degree of polymerization of 8 (DP8) was found to inhibit the expression of osteogenic markers and, thus, prevent the conversion of vascular smooth muscle cells into osteoblast-like cells. We also evidenced in biochemical and immunofluorescence assays a direct interaction between matrix vesicles and type I collagen via the GFOGER sequence (where single letter amino acid nomenclature is used, O=hydroxyproline) thought to be involved in interactions with several pairs of integrins. CONCLUSIONS: DP8 inhibits vascular calcification development mainly by inhibition of osteogenic marker expression but also partly by masking the GFOGER sequence-thereby, preventing matrix vesicles from binding to type I collagen.
    Mots-clés : Animals, Aorta, Thoracic, Aortic Diseases, Binding Sites, Biomarkers, Calcium, Cell Transdifferentiation, Cells, Cultured, Collagen Type I, Crystallization, Dose-Response Relationship, Drug, Extracellular Vesicles, Male, matrix vesicle, Mice, Muscle, Smooth, Vascular, Myocytes, Smooth Muscle, oligogalacturonic acid, Oligosaccharides, Osteogenesis, Protein Binding, Protein Interaction Domains and Motifs, Rats, Wistar, Signal Transduction, Tissue Culture Techniques, type I collagen, Vascular Calcification.

  • Houben D, Hardy B, Faucon M-P, Cornelis J-T. Effect of biochar on phosphorus bioavailability in an acidic silt loam soil - Effet du biochar sur la biodisponibilité du phosphore dans un sol limoneux acide. Biotechnology, Agronomy and Society and Environment 2017. (consulté sans date).
    Résumé : Description du sujet. Cet article traite de l'impact du biochar sur la biodisponibilité en phosphore (P) dans les sols en vue d'améliorer la gestion et l'autonomie de la fertilisation en P des cultures. Objectifs. L'objectif général était d'explorer le potentiel du biochar à augmenter la biodisponibilité du P dans le sol. Les objectifs spécifiques étaient de préciser l'influence de la biomasse pyrolysée ainsi que la dose de biochar appliquée sur la solubilité du P. Méthode. Trois biochars produits à partir de biomasses différentes (résidus de Miscanthus, de bois et de café) ont été incorporés dans un Luvisol (pH acide) selon deux doses (1 et 3 % en masse). Après 76 jours d'incubation, la biodisponibilité du P a été estimée (extraction au CaCl 2 0,01 M). Les propriétés physico-chimiques du sol et la quantité de CO 2 émise durant la période d'incubation ont également été déterminées. Résultats. Seul le biochar produit à partir de résidus de bois et incorporé à une dose de 3 % a augmenté la concentration en P biodisponible dans le sol (+ 75 %). Cette augmentation résulterait non seulement d'une libération de P par le biochar lui-même (effet direct), mais également d'une remobilisation du P du sol (effet indirect) faisant suite à l'élévation drastique du pH (+ 3,6 unités) ainsi qu'à l'augmentation de l'activité biologique. Pour les autres traitements, l'absence d'effet significatif sur la biodisponibilité du P résulte vraisemblablement de leur faible impact sur le pH du sol, celui-ci restant dans une gamme (4,3 – 5,1) favorisant l'insolubilisation du P. Conclusions. Étant donné la variabilité des résultats et les incertitudes concernant les mécanismes responsables de la mobilisation du P en présence de biochar, il est essentiel de conduire des études complémentaires afin de mieux comprendre l'impact du biochar sur la mobilité du P dans les systèmes sol-plante. Effect of biochar on phosphorus bioavailability in an acidic silt loam soil Description of the subject. This paper deals with the impact of biochar on soil phosphorus (P) bioavailability with a view to improving the management of P fertilization. Objectives. The aim of this study was to explore the potential of biochar to increase P bioavailability in soil. The specific objectives were to elucidate the role of feedstock and the rate of application of biochar on P solubility. Method. Three biochars produced from different feedstocks (Miscanthus straws, coffee husks and woody material) were added to an acidic Luvisol at two rates of application (1% and 3%; w/w). At the end of a 76-day incubation period, P bioavailability was assessed (0.01 M CaCl 2 extraction). Soil physico-chemical properties and the amount of CO 2 emitted over the incubation period were also determined. Results. The wood-derived biochar applied at 3% was the only treatment that increased significantly P bioavailability (+ 75%). This increase might result from the release of P by biochar itself (direct effect) but also from an enhanced P solubility in soil (indirect effect) related to a large increase in pH (+3.6 units compared to the control) and a higher soil biological activity. The other treatments had no significant impact on soil P bioavailability, probably as a result of their minor effect on soil pH. Conclusions. Our study shows that biochar-induced changes in P bioavailability in soil varied greatly with type of feedstock and rate of application. However, the balance between the direct and indirect effects of biochar on P bioavailability was not elucidated. Further investigations are thus essential to clarify the potential of biochar to improve P bioavailability in the soil-plant system.

  • Husson E, Hadad C, Huet G, et al. The effect of room temperature ionic liquids on the selective biocatalytic hydrolysis of chitin via sequential or simultaneous strategies. Green Chemistry 2017; 19: 4122-4131.
    Résumé : An efficient conversion of chitin, the second most abundant renewable polymer on the Earth, into N-acetylglucosamine and N,N′-diacetylchitobiose, using room temperature ionic liquids (RTILs) and commercially available chitinases is described for the first time. The sequential strategy consists of the use of RTILs to pretreat chitin under mild conditions as a first step before enzymatic hydrolysis. [C2mim][OAc] (1-ethyl-3-methyl imidazolium) pretreatment provides an efficient production of N-acetylglucosamine (185.0 ± 4.0 mg per g chitin) or N,N′-diacetylchitobiose (667.60 ± 20.71 mg per g chitin) catalyzed by chitinase from Trichoderma viride or Streptomyces griseus, respectively. A thorough investigation of the structural changes of chitin induced by RTIL pretreatment suggested an increase in enzymes’ accessibility to the chitin substrate. Alternatively, a one-pot enzymatic hydrolysis of chitin in [C2mim][OAc]-aqueous medium constitutes a promising simultaneous route to selectively generate N-acetylglucosamine or N,N′-diacetylchitobiose by decreasing the required [C2mim][OAc] amount and the number of steps. Finally, the combination of the two chitinases from T. viride and S. griseus was shown to be very relevant to considerably increase the production of N-acetylglucosamine up to 760.0 ± 0.1 mg per g chitin.

  • Janvier M, Hollande L, Jaufurally AS, et al. Syringaresinol: A Renewable and Safer Alternative to Bisphenol A for Epoxy-Amine Resins. ChemSusChem 2017; 10: 738-746.
    Résumé : A renewable bisepoxide, SYR-EPO, was prepared from syringaresinol, a naturally occurring bisphenol deriving from sinapic acid, by using a chemo-enzymatic synthetic pathway. Estrogenic activity tests revealed no endocrine disruption for syringaresinol. Its glycidylation afforded SYR-EPO with excellent yield and purity. This biobased, safe epoxy precursor was then cured with conventional and renewable diamines for the preparation of epoxy-amine resins. The resulting thermosets were thermally and mechanically characterized. Thermal analyses of these new resins showed excellent thermal stabilities (Td5 % =279-309 °C) and Tg ranging from 73 to 126 °C, almost reaching the properties of those obtained with the diglycidylether of bisphenol A (DGEBA), extensively used in the polymer industry (Td5 % =319 °C and Tg =150 °C for DGEBA/isophorone diamine resins). Degradation studies in NaOH and HCl aqueous solutions also highlighted the robustness of the syringaresinol-based resins, similar to bisphenol A (BPA). All these results undoubtedly confirmed the potential of syringaresinol as a greener and safer substitute for BPA.
    Mots-clés : Amines, Benzhydryl Compounds, bisepoxide, bisphenol A, DGEBA, Epoxy Resins, Furans, Green Chemistry Technology, Lignans, Phenols, Polymers, resin, syringaresinol.

  • Jeandet P. Structure, Chemical Analysis, Biosynthesis, Metabolism, Molecular Engineering, and Biological Functions of Phytoalexins. Molecules 2017; 23: 61.
    Résumé : Plants in their natural environment are facing large numbers of pathogenic microorganisms, mainly fungi and bacteria.[…]
    Mots-clés : n/a.

  • Jeandet P, Courot E, Clément C, et al. Molecular Engineering of Phytoalexins in Plants: Benefits and Limitations for Food and Agriculture - Journal of Agricultural and Food Chemistry (ACS Publications). 2017. (consulté 6 sept.2018).

  • Kfoury M, Landy D, Ruellan S, Auezova L, Greige-Gerges H, Fourmentin S. Nootkatone encapsulation by cyclodextrins: Effect on water solubility and photostability. Food Chemistry 2017; 236: 41-48.
    Résumé : Nootkatone (NO) is a sesquiterpenoid volatile flavor, used in foods, cosmetics and pharmaceuticals, possessing also insect repellent activity. Its application is limited because of its low aqueous solubility and stability; this could be resolved by encapsulation in cyclodextrins (CDs). This study evaluated the encapsulation of NO by CDs using phase solubility studies, Isothermal Titration Calorimetry, Nuclear Magnetic Resonance spectroscopy and molecular modeling. Solid CD/NO inclusion complex was prepared and characterized for encapsulation efficiency and loading capacity using UV–Visible. Thermal properties were investigated by thermogravimetric-differential thermal analysis and release studies were performed using multiple headspace extraction. Formation constants (Kf) proved the formation of stable inclusion complexes. NO aqueous solubility, photo- and thermal stability were enhanced and the release could be insured from solid complex in aqueous solution. This suggests that CDs are promising carrier to improve NO properties and, consequently, to enlarge its use in foods, cosmetics, pharmaceuticals and agrochemicals preparations.
    Mots-clés : Cyclodextrin, Encapsulation efficiency, Formation constant, Nootkatone, Photostability, Release, Solubility.

  • Kfoury M, Pipkin JD, Antle V, Fourmentin S. Captisol®: an efficient carrier and solubilizing agent for essential oils and their components. Flavour and Fragrance Journal 2017; 32: 340-346.
    Résumé : Essential oils (EOs) and their individual components have several biological properties and are used in cosmetics, food and pharmaceutical industries. However, their application still presents a challenge owing mainly to their volatility and their poor aqueous solubility and stability. The aim of this study was to evaluate, for the first time, the ability of Captisol® (sulfobutylether-β-cyclodextrin, SBE-β-CD) and Captisol-G® (sulfobutylether-γ-cyclodextrin, SBE-γ-CD) to encapsulate the main volatile components of six essential oils (EOs), to enhance the aqueous solubility of these EOs and to generate controlled release systems. The performance of these CDs was compared to hydroxypropyl-β-cyclodextrin (HP-β-CD) and γ-cyclodextrin (γ-CD), respectively. Formation constants (Kf) of the 40 inclusion complexes were determined by Static Headspace-Gas Chromatography (SH-GC). Then, Total Organic Carbon (TOC) was used to explore and quantify the efficiency of Captisol® and HP-β-CD to enhance the solubility of the six EOs. Finally, multiple headspace extraction (MHE) was applied to perform release studies. Kf values underlined the best binding potential of Captisol® towards all guests. Phase solubility diagrams showed that both Captisol® and HP-β-CD greatly increased the apparent solubility of EOs. The solubilizing potential was inversely proportionate to the EOs intrinsic solubility (SEO). Results indicated that Captisol® can successfully encapsulate EOs, increase their apparent aqueous solubility and decrease their release kinetics. Thus, Captisol® could be considered as a promising carrier to enlarge the application of EOs and their components.
    Mots-clés : Captisol®, cyclodextrins, essential oils, phase solubility, Total Organic Carbon.

  • Kowalski D, Mallet J, Thomas S, et al. Electrochemical synthesis of 1D core-shell Si/TiO2 nanotubes for lithium ion batteries. Journal of Power Sources 2017; 361: 243-248.
    Résumé : Silicon negative electrode for lithium ion battery was designed in the form of self-organized 1D core-shell nanotubes to overcome shortcomings linked to silicon volume expansion upon lithiation/delithiation typically occurring with Si nanoparticles. The negative electrode was formed on TiO2 nanotubes in two step electrochemical synthesis by means of anodizing of titanium and electrodeposition of silicon using ionic liquid electrolytes. Remarkably, it was found that the silicon grows perpendicularly to the z-axis of nanotube and therefore its thickness can be precisely controlled by the charge passed in the electrochemical protocol. Deposited silicon creates a continuous Si network on TiO2 nanotubes without grain boundaries and particle-particle interfaces, defining its electrochemical characteristics under battery testing. In the core-shell system the titania nanotube play a role of volume expansion stabilizer framework holding the nanostructured silicon upon lithiation/delithiation. The nature of Si shell and presence of titania core determine stable performance as negative electrode tested in half cell of CR2032 coin cell battery.
    Mots-clés : Electrosynthesis, Nanotubes, Silicon, Silicon anode, Titania.

  • Krier F, Coutte F, Duthoo C, et al. Studies of the potential of new biomolecules for the protection of plants in organic agriculture. 6e COMAPPI, Conférence sur les Moyens Alternatifs de Protection pour une Production Intégrée, Lille, France, 21-23 mars 2017 2017; : 322-331.
    Résumé : The NEWBIOPEST project brings together for the first time in the Hauts-de-France Region a consortium of three universities and two agricultural technical institutes and address the question of reduction of the impact of agricultural practices on human health and the environment. In particular, it aims to offer solutions to accelerate the development of organic agriculture in this Region. The...

  • Labidi S, Firmin S, Verdin A, et al. Nature of fly ash amendments differently influences oxidative stress alleviation in four forest tree species and metal trace element phytostabilization in aged contaminated soil: A long-term field experiment. Ecotoxicology and Environmental Safety 2017; 138: 190-198.
    Résumé : Aided phytostabilization using coal fly ashes (CFAs) is an interesting technique to clean-up polluted soils and valorizing industrial wastes. In this context, our work aims to study the effect of two CFAs: silico-aluminous (CFA1) and sulfo-calcic (CFA2) ones, 10 years after their addition, on the phytostabilization of a highly Cd (cadmium), Pb (lead) and Zn (zinc) contaminated agricultural soil, with four forest tree species: Robinia pseudoacacia, Alnus glutinosa, Acer pseudoplatanus and Salix alba. To assess the effect of CFAs on trees, leaf fatty acid composition, malondialdehyde (MDA), oxidized and reduced glutathione contents ratio (GSSG: GSH), 8-hydroxy-2'-deoxyguanosine (8-OHdG), Peroxidase (PO) and Superoxide dismutase (SOD) activities were examined. Our results showed that CFA amendments decreased the CaCl2-extractable fraction of Cd and Zn from the soil. However, no significant effect was observed on metal trace element (MTE) concentrations in leaves. Fatty acid percentages were only affected by the addition of sulfo-calcic CFA. The most affected species were A. glutinosa and R. pseudoacacia in which C16:0, C18:0 and C18:2 percentages increased significantly whereas the C18:3 decreased. The addition of sulfo-calcic CFA induced the antioxidant systems response in tree leaves. An increase of SOD and POD activities in leaves of trees planted on the CFA2-amended plot was recorded. Conversely, silico-aluminous CFA generated a reduction of lipid and DNA oxidation associated with the absence or low induction of anti-oxidative processes. Our study evidenced oxidative stress alleviation in tree leaves due to CFA amendments. MTE mobility in contaminated soil and their accumulation in leaves differed with the nature of CFA amendments and the selected tree species.
    Mots-clés : Acer, Alnus, Biodegradation, Environmental, Cadmium, Coal Ash, Coal fly ashes, Deoxyguanosine, Fatty Acids, Forest trees, Glutathione, Lead, Malondialdehyde, MTE mobility, Oxidative Stress.

  • Lakraychi AE, Dolhem F, Djedaïni-Pilard F, Thiam A, Frayret C, Becuwe M. Decreasing redox voltage of terephthalate-based electrode material for Li-ion battery using substituent effect. Journal of Power Sources 2017; 359: 198-204.
    Résumé : The preparation and assessment versus lithium of a functionalized terephthalate-based as a potential new negative electrode material for Li-ion battery is presented. Inspired from molecular modelling, a decrease in redox potential is achieved through the symmetrical adjunction of electron-donating fragments (–CH3) on the aromatic ring. While the electrochemical activity of this organic material was maximized when used as nanocomposite and without any binder, the potential is furthermore lowered by 110 mV upon functionalization, consistently with predicted value gained from DFT calculations.
    Mots-clés : Binder-free electrode, DFT calculations, Organic anode material, Structure-property relationships, Substituent effect.

  • Lakraychi AE, Fahsi K, Aymard L, Poizot P, Dolhem F, Bonnet J-P. Carboxylic and sulfonic N-substituted naphthalene diimide salts as highly stable non-polymeric organic electrodes for lithium batteries. Electrochemistry Communications 2017; 76: 47-50.
    Résumé : Two N-substituted naphthalene tetracarboxylic diimide (NTCDI) ionic compounds, carboxylic and sulfonic sodium salts, were prepared and used as positive electrode active materials in lithium-half cells. The aim of this investigation was to assess the solubility-suppressing effect of two different negatively charged substituent groups on a redox-active organic backbone using a carbonate-based liquid electrolyte. NTCDI derivatives were obtained in high yields from reaction of naphthalene tetracarboxylic dianhydride with neutralized glycine or with neutralized taurine. They were mixed with carbon black and cycled in galvanostatic mode against lithium metal using 1M LiPF6 EC/DMC liquid electrolyte. These two NTCDI derivatives exhibit a quite stable electrochemical activity upon cycling at an average potential of 2.3V vs. Li+/Li0 giving rise to specific capacity values of 147mAh·g−1 and 113mAh·g−1 for the dicarboxylate and the disulfonate derivative, respectively. This study clearly supports the useful effect of such grafted permanent charges as a general rule on the electrochemical stability of crystallized organic materials based on the assembly of small redox-active units.
    Mots-clés : Lithium batteries, Naphthalene diimide, Organic batteries, Organic electrode.

  • Lange B, Van der Ent A, Baker AJM, et al. Copper and cobalt accumulation in plants: a critical assessment of the current state of knowledge. New Phytologist 2017; 213: 537-551.
    Résumé : This review synthesizes contemporary understanding of copper-cobalt (Cu-Co) tolerance and accumulation in plants. Accumulation of foliar Cu and Co to > 300 μg g-1 is exceptionally rare globally, and known principally from the Copperbelt of Central Africa. Cobalt accumulation is also observed in a limited number of nickel (Ni) hyperaccumulator plants occurring on ultramafic soils around the world. None of the putative Cu or Co hyperaccumulator plants appears to comply with the fundamental principle of hyperaccumulation, as foliar Cu-Co accumulation is strongly dose-dependent. Abnormally high plant tissue Cu concentrations occur only when plants are exposed to high soil Cu with a low root to shoot translocation factor. Most Cu-tolerant plants are Excluders sensu Baker and therefore setting nominal threshold values for Cu hyperaccumulation is not informative. Abnormal accumulation of Co occurs under similar circumstances in the Copperbelt of Central Africa as well as sporadically in Ni hyperaccumulator plants on ultramafic soils; however, Co-tolerant plants behave physiologically as Indicators sensu Baker. Practical application of Cu-Co accumulator plants in phytomining is limited due to their dose-dependent accumulation characteristics, although for Co field trials may be warranted on highly Co-contaminated mineral wastes because of its relatively high metal value.

  • Leblond J, Potier J, Menuel S, et al. Water-soluble phosphane-substituted cyclodextrin as an effective bifunctional additive in hydroformylation of higher olefins. Catalysis Science & Technology 2017; 7: 3823-3830.
    Résumé : In cyclodextrin (CD)-mediated aqueous biphasic catalysis, favoring contacts between the CD (“host”), the organic substrate (“guest”) and the water-soluble catalyst is crucial for the reaction to proceed efficiently at the aqueous/organic interface. Grafting the catalyst onto the CD backbone thus appears as an attractive approach to favor the molecular recognition of the substrate and its subsequent catalytic conversion into products. In this context, a new water-soluble β-CD-based phosphane was synthesized and characterized by NMR, tensiometric and ITC measurements. The β-CD-based phosphane consisted of a 3,3′-disulfonatodiphenyl phosphane connected to the primary face of β-CD by a dimethyleneamino spacer. Intra- and intermolecular inclusion processes of one of the two sulfophenyl groups into the β-CD cavity were identified in water. However, the association constant (Ka) related to the β-CD/sulfophenyl group couple was low. Accordingly, the inclusion process was easily displaced upon coordination to rhodium complexes. The efficacy of the resulting Rh-complex coordinated by β-CD-based phosphanes was assessed in Rh-catalyzed hydroformylation of higher olefins. The catalytic system proved to be far more successful and efficient than a system consisting of supramolecularly interacting phosphanes and CDs. The catalytic activity was up to 30-fold higher while the chemo- and regioselectivities remain rather unchanged.

  • Lenoir I, Fontaine J, Tisserant B, Laruelle F, Lounès-Hadj Sahraoui A. Beneficial contribution of the arbuscular mycorrhizal fungus, Rhizophagus irregularis, in the protection of Medicago truncatula roots against benzo[a]pyrene toxicity. 2017. (consulté 6 sept.2018).
    Résumé : Arbuscular mycorrhizal fungi are able to improve plant establishment in polluted soils but little is known about the genes involved in the plant protection against pollutant toxicity by mycorrhization, in particular in the presence of polycyclic aromatic hydrocarbons (PAH). The present work aims at studying in both symbiotic partners, Medicago truncatula and Rhizophagus irregularis: (i) expression of genes putatively involved in PAH tolerance (MtSOD, MtPOX, MtAPX, MtGST, MtTFIIS, and MtTdp1α), (ii) activities of antioxidant (SOD, POX) and detoxification (GST) enzymes, and (iii) HO and the heavy PAH, benzo[a]pyrene (B[a]P) accumulation. In the presence of B[a]P, whereas induction of the enzymatic activities was detected in R. irregularis and non-mycorrhizal roots as well as upregulation of the gene expressions in the non-mycorrhizal roots, downregulation of the gene expressions and decrease of enzyme activities were observed in mycorrhizal roots. Moreover, B[a]P increased HO production in non-mycorrhizal roots and in R. irregularis but not in mycorrhizal roots. In addition, a lower B[a]P bioaccumulation in mycorrhizal roots was measured in comparison with non-mycorrhizal roots. Being less affected by pollutant toxicity, mycorrhizal roots did not activate any defense mechanism either at the gene expression regulation level or at the enzymatic level.

  • Lenoir J, Hattab T, Pierre G. Climatic microrefugia under anthropogenic climate change: implications for species redistribution. Ecography 2017; 40: 253-266.
    Résumé : The role of modern climatic microrefugia is a neglected aspect in the study of biotic responses to anthropogenic climate change. Current projections of species redistribution at continental extent are based on climatic grids of coarse (≥ 1 km) resolutions that fail to capture spatiotemporal dynamics associated with climatic microrefugia. Here, we review recent methods to model the climatic component of potential microrefugia and highlight research gaps in accounting for the buffering capacity due to biophysical processes operating at very fine (< 1 m) resolutions (e.g. canopy cover) and the associated microclimatic stability over time (i.e. decoupling). To overcome this challenge, we propose a spatially hierarchical downscaling framework combining a free-air temperature grid at 1 km resolution, a digital elevation model at 25 m resolution and small-footprint light detection-and-ranging (LiDAR) data at 50 cm resolution with knowledge from the literature to mechanistically model sub-canopy temperatures and account for microclimatic decoupling. We applied this framework on a virtual sub-canopy species and simulated the impact of a warming scenario on its potential distribution. Modelling sub-canopy temperatures at 50 cm resolution and accounting for microclimatic stability over time enlarges the range of temperature conditions towards the cold end of the gradient, mitigates regional temperature changes and decreases extirpation risks. Incorporating these spatiotemporal dynamics into species redistribution models, being correlative, mechanistic or hybrid, will increase the probability of local persistence, which has important consequences in the understanding of the capacity of species to adapt. We finally provide a synthesis on additional ways that the field could move towards effectively considering potential climatic microrefugia for species redistribution.
    Mots-clés : Anthropogenic, APR 2014, Climate Change, Microrefugia, Projet CREUSE, Suite projet SFR.

  • Lu B, Miao Y, Vigneron P, et al. Measurement of cytotoxicity and irritancy potential of sugar-based surfactants on skin-related 3D models. Toxicology in Vitro 2017; 40: 305-312.
    Résumé : Sugar-based surfactants present surface-active properties and relatively low cytotoxicity. They are often considered as safe alternatives to currently used surfactants in cosmetic industries. In this study, four sugar-based surfactants, each with an eight carbon alkyl chain bound to a glucose or a maltose headgroup through an amide linkage, were synthesized and compared to two standard surfactants. The cytotoxic and irritant effects of surfactants were evaluated using two biologically relevant models: 3D dermal model (mouse fibroblasts embedded in collagen gel) and reconstituted human epidermis (RHE, multi-layered human keratinocytes). Results show that three synthesized surfactants possess lower cytotoxicity compared to standard surfactants as demonstrated in the 3D dermal model. Moreover, the IC50s of surfactants against the 3D dermal model are higher than IC50s obtained with the 2D dermal model (monolayer mouse fibroblasts). Both synthesized and standard surfactants show no irritant effects after 48h of topical application on RHE. Throughout the study, we demonstrate the difficulty to link the physico-chemical properties of surfactants and their cytotoxicity in complex models. More importantly, our data suggest that, prior to in vivo tests, a complete understanding of surfactant cytotoxicity or irritancy potential requires a combination of cellular and tissue models.
    Mots-clés : Cosmetic products testing, Cytotoxicity, Dermal equivalents, Irritancy screening, Reconstituted human epidermis, Sugar-based surfactants.

  • Magnin-Robert M, Adrian M, Trouvelot S, et al. Alterations in Grapevine Leaf Metabolism Occur Prior to Esca Apoplexy Appearance. Molecular Plant-Microbe Interactions 2017; 30: 946-959.
    Mots-clés : Axe 1, esca, vigne.

  • Mejri S, Siah A, Coutte F, et al. Biocontrol of the wheat pathogen Zymoseptoria tritici using cyclic lipopeptides from Bacillus subtilis. Environmental Science and Pollution Research 2017. doi:10.1007/s11356-017-9241-9.
    Résumé : Innovation toward ecofriendly plant protection products compatible with sustainable agriculture and healthy food is today strongly encouraged. Here, we assessed the biocontrol activity of three cyclic lipopeptides from Bacillus subtilis (mycosubtilin, M; surfactin, S; fengycin, F) and two mixtures (M + S and M + S + F) on wheat against Zymoseptoria tritici, the main pathogen on this crop. Foliar application of these biomolecules at a 100-mg L−1 concentration on the wheat cultivars Dinosor and Alixan, 2 days before fungal inoculation, provided significant reductions of disease severity. The best protection levels were recorded with the M-containing formulations (up to 82% disease reduction with M + S on Dinosor), while S and F treatments resulted in lower but significant disease reductions. In vitro and in planta investigations revealed that M-based formulations inhibit fungal growth, with half-maximal inhibitory concentrations of 1.4 mg L−1 for both M and M + S and 4.5 mg L−1 for M + S + F, thus revealing that the observed efficacy of these products may rely mainly on antifungal property. By contrast, S and F had no direct activity on the pathogen, hence suggesting that these lipopeptides act on wheat against Z. tritici as resistance inducers rather than as biofungicides. This study highlighted the efficacy of several lipopeptides from B. subtilis to biocontrol Z. tritici through likely distinct and biomolecule-dependent modes of action.
    Mots-clés : Bacillus subtilis, Biocontrol, Lipopeptides, Mycosubtilin, Wheat, Zymoseptoria tritici.

  • Mondello V, Songy A, Battiston E, et al. Grapevine Trunk Diseases: A Review of Fifteen Years of Trials for Their Control with Chemicals and Biocontrol Agents. Plant Disease 2017; 102: 1189-1217.
    Résumé : Grapevine trunk diseases (GTDs) represent one of the most important problems for viticulture worldwide. Beyond the original causes of this outbreak in some countries like France, the lack of efficient control protocols and the prohibition of using active ingredients such as sodium arsenite and benzimidazoles, until recently used to reduce the impact of some GTDs but deleterious for humans and the environment, have probably worsened the impact of the diseases, leading to increasing economic losses. Since 1990, searches have been made to find efficient tools to control GTDs, testing a wide range of active ingredients and biocontrol agents. This review provides readers with an overview of the results reported in the scientific literature over the last 15 years. In particular, the review focuses on the trials carried out applying chemicals or microorganisms to control Esca complex diseases, Botryosphaeria dieback, and Eutypa dieback, the most widespread GTDs.

  • Moura L, Moufawad T, Ferreira M, et al. Deep eutectic solvents as green absorbents of volatile organic pollutants. 2017. (consulté 7 sept.2018).
    Résumé : Volatile organic compounds are a major source of air pollutants. Absorption is an effective solution to treat polluted air loaded with volatile organic compounds, but most actual absorbents are often toxic and non-biodegradable. Here, we tested eutectic solvent mixtures for the absorption of volatile organic compounds for the first time. The affinity of solvent mixtures for toluene, acetaldehyde and dichloromethane was determined by measuring vapour–liquid partition coefficients and liquid phase absorption capacities. Results show that the vapour–liquid partition coefficients vary, at 30 °C, from close to zero for acetaldehyde in the mixtures choline chloride:urea, choline chloride:glycerol and tetrabutylphosphonium bromide:glycerol to 0.124 for dichloromethane in the choline chloride:urea eutectic mixture. These values are similar or even superior to those published for ionic liquids and organic solvents. Solvents based on choline chloride, a food additive, and urea, can solubilize up to 500 times more volatile organic compounds compare to water. Moreover, deep eutectic solvents are easier to prepare and more biodegradable than ionic liquids, which are also toxic. Deep eutectic solvents are more biodegradable than silicone oils, which are also expensive. Furthermore, in terms of recycling, the absorption capacities of the tested solvents remained unchanged during five absorption–desorption cycles. These findings are patented.

  • Moussawi MA, Leclerc-Laronze N, Floquet S, et al. Polyoxometalate, Cationic Cluster, and γ-Cyclodextrin: From Primary Interactions to Supramolecular Hybrid Materials. Journal of the American Chemical Society 2017; 139: 12793-12803.
    Résumé : Herein, we report on a three-component supramolecular hybrid system built from specific recognition processes involving a Dawson-type polyoxometalate (POM), [P2W18O62]6–, a cationic electron-rich cluster [Ta6Br12(H2O)6]2+, and γ-cyclodextrin (γ-CD). Such materials have been investigated using a bottom-up approach by studying the specific interactions between γ-CD and both types of inorganic units. Their ability to interact has been investigated in the solid state by single-crystal X-ray diffraction (XRD) and in solution using multinuclear NMR methods (including DOSY, EXSY, and COSY), electrospray ionization mass and UV–vis spectroscopies, electrochemistry, and isothermal titration calorimetry experiments. Single-crystal XRD analysis reveals that POM:γ-CD constitutes a highly versatile system which gives aggregates with 1:1, 1:2, and 1:3 stoichiometry. Surprisingly, these arrangements exhibit a common feature wherein the γ-CD moiety interacts with the Dawson-type POMs through its primary face. We present also the first structural model involving an octahedral-type metallic cluster with γ-CD. XRD study reveals that the cationic [Ta6Br12(H2O)6]2+ ion is closely embedded within two γ-CD units to give a supramolecular ditopic cation, suitable to be used as a linker within extended structure. Solution study demonstrates clearly that pre-associations exist in solution, for which binding constants and thermodynamic parameters have been determined, giving preliminary arguments about the chaotropic nature of the inorganic ions. Finally, both building blocks, i.e., the ditopic supramolecular cation {[Ta6Br12(H2O)6]@2CD}2+ and the Dawson-type anion, react together to give a three-component, well-ordered hybrid material derived either as a supramolecular hydrogel or single crystals. The solid-state structure shows an unprecedented helicoidal tubular chain resulting from the periodic alternation of POM and supramolecular cation, featuring short hydrogen-bonding contacts between the electron-poor POM and electron-rich cluster. The 1D tubular ionic polymer observed in the single crystals should make it possible to understand the long-range ordering observed within the hydrogel hybrid material. The supramolecular chemical complementarities between the γ-CD-based ditopic cation and POM open a wide scope for the design of hybrid materials that accumulate synergistic functionalities.

  • Moyé J, Picard-Lesteven T, Zouhri L, El Amari K, Hibti M, Benkaddour A. Groundwater assessment and environmental impact in the abandoned mine of Kettara (Morocco). Environmental Pollution 2017; 231: 899-907.
    Résumé : Many questions about the soil pollution due to mining activities have been analyzed by numerous methods which help to evaluate the dispersion of the Metallic Trace Elements (MTE) in the soil and stream sediments of the abandoned mine of Kettara (Morocco). The transport of these MTE could have an important role in the degradation of groundwater and the health of people who are living in the vicinity. The present paper aims to evaluate the groundwater samples from 15 hydrogeological wells. This evaluation concerns the hydrogeological parameters, pH, Electrical conductivity, temperature and the groundwater level, and the geochemical assessment of Mg, Ca, Ti, Cr, Mn, Fe, Co, Ni, Zn, Cu, As, Se, Cd, Sb, Tl and Pb. Furthermore, the Metallic Trace Elements are transported in the saturated zone via the fractures network. The groundwater flow is from the north-east to south-west. The spatial distribution of As, Fe, Zn and Mn is very heterogeneous, with high values observed in the north, upstream, of the mine site. This distribution is maybe related to: i) the existence of hydrogeological structures (dividing and drainage axes); ii) the individualization of the fractures network that affects the shaly lithostratigraphical formation; iii) the transport of the contaminants from the soil towards groundwater; and iv) interaction water/rocks. Some MTE anomalies are linked to the lithology and the fracturation system of the area. Therefore, the groundwater contamination by Arsenic is detected in the hydrogeological wells (E1 and E2). This pollution which is higher than guideline standards of Moroccan drinking water could affect the public health. The hydrogeological and geochemical investigations favor the geological origin (mafic rocks) of this contamination rather than mining activities.
    Mots-clés : Environment, Groundwater, Mine, Morocco, Pollution.

  • Muchembled J, Deweer C, Sahmer K, Halama P. Antifungal activity of essential oils on two Venturia inaequalis strains with different sensitivities to tebuconazole. Environmental Science and Pollution Research 2017. doi:10.1007/s11356-017-0507-z.
    Résumé : The antifungal activity of seven essential oils (eucalyptus, clove, mint, oregano, savory, tea tree, and thyme) was studied on Venturia inaequalis, the fungus responsible for apple scab. The composition of the essential oils was checked by gas chromatography-mass spectrometry. Each essential oil had its main compound. Liquid tests were performed to calculate the IC50 of essential oils as well as their majority compounds. The tests were made on two strains with different sensitivities to tebuconazole: S755, the sensitive strain, and rs552, the strain with reduced sensitivity. Copper sulfate was selected as the reference mineral fungicidal substance. IC50 with confidence intervals were calculated after three independent experiments. The results showed that all essential oils and all major compounds had in vitro antifungal activities. Moreover, it was highlighted that the effectiveness of four essential oils (clove, eucalyptus, mint, and savory) was higher than copper sulfate on both strains. For each strain, the best activity was obtained using clove and eucalyptus essential oils. For clove, the IC50 obtained on the sensitive strain (5.2 mg/L [4.0–6.7 mg/L]) was statistically lower than the IC50 of reduced sensitivity strain (14 mg/L [11.1–17.5 mg/L]). In contrast, for eucalyptus essential oil, the IC50 were not different with respectively 9.4–13.0 and 12.2–17.9 mg/L for S755 and rs552 strains. For mint, origano, savory, tea tree, and thyme, IC50 were always the best on rs552 strain. The majority compounds were not necessarily more efficient than their corresponding oils; only eugenol (for clove) and carvacrol (for oregano and savory) seemed to be more effective on S755 strain. On the other hand, rs552 strain seemed to be more sensitive to essential oils than S755 strain. In overall, it was shown that essential oils have different antifungal activities but do not have the same antifungal activities depending on the fungus strain used.
    Mots-clés : Biofungicide, Essential oils, In vitro assay, Venturia inaequalis.

  • Muraille L, Aguié-Béghin V, Chabbert B, Molinari M. Bioinspired lignocellulosic films to understand the mechanical properties of lignified plant cell walls at nanoscale. Scientific Reports 2017; 7: 44065.
    Résumé : The physicochemical properties of plant fibres are determined by the fibre morphology and structural features of the cell wall, which is composed of three main layers that differ in chemical composition and architecture. This composition and hierarchical structure are responsible for many of the mechanical properties that are desirable for industrial applications. As interactions between the lignocellulosic polymers at the molecular level are the main factor governing the final cohesion and mechanical properties of plant fibres, atomic force microscopy (AFM) is well suited for the observation and measurement of their physical properties at nanoscale levels. Given the complexity of plant cell walls, we have developed a strategy based on lignocellulosic assemblies with increasing complexity to understand the influence of the different polymers on the nanomechanical properties. Measurements of the indentation moduli performed on one type of lignified cell wall compared with those performed on the corresponding lignocellulosic films clearly show the importance of the lignin in the mechanical properties of cell walls. Through this strategy, we envision a wide application of bioinspired systems in future studies of the physical properties of fibres.

  • Mustafa G, Khong NG, Tisserant B, et al. Defence mechanisms associated with mycorrhiza-induced resistance in wheat against powdery mildew. Functional Plant Biology 2017; 44: 443-454.
    Résumé : To develop a more sustainable agriculture using alternative control strategies, mechanisms involved in the biocontrol ability of the arbuscular mycorrhizal fungus Funneliformis mosseae to protect wheat against the foliar biotrophic pathogen Blumeria graminis f. sp. tritici were investigated under controlled conditions. B. graminis infection on wheat leaves was reduced by 78% in mycorrhizal plants compared with non-mycorrhizal ones (control). Wheat roots inoculated with F. mosseae revealed a systemic resistance in leaves to B. graminis, after a 6-week co-culture. Accordingly, this resistance was associated with a significant reduction of B. graminis haustorium formation in epidermal leaf cells of mycorrhizal wheat and an accumulation of phenolic compounds and H2O2 at B. graminis penetration sites. Moreover, gene expression analysis demonstrated upregulation of genes encoding for several defence markers, such as peroxidase, phenylalanine ammonia lyase, chitinase 1 and nonexpressor of pathogenesis-related proteins 1 in mycorrhizal wheat only in the absence of the pathogen. This study showed that protection of wheat obtained against B. graminis in response to mycorrhizal inoculation by F. mosseae could be interpreted as a mycorrhiza-induced resistance (MIR). Our findings also suggest that MIR-associated mechanisms impaired the B. graminis development process and corresponded to a systemic elicitation of plant defences rather than a primed state in wheat leaves.

  • Nasir MN, Lins L, Crowet J-M, et al. Differential Interaction of Synthetic Glycolipids with Biomimetic Plasma Membrane Lipids Correlates with the Plant Biological Response. Langmuir: the ACS journal of surfaces and colloids 2017; 33: 9979-9987.
    Résumé : Natural and synthetic amphiphilic molecules including lipopeptides, lipopolysaccharides, and glycolipids are able to induce defense mechanisms in plants. In the present work, the perception of two synthetic C14 rhamnolipids, namely, Alk-RL and Ac-RL, differing only at the level of the lipid tail terminal group have been investigated using biological and biophysical approaches. We showed that Alk-RL induces a stronger early signaling response in tobacco cell suspensions than does Ac-RL. The interactions of both synthetic RLs with simplified biomimetic membranes were further analyzed using experimental and in silico approaches. Our results indicate that the interactions of Alk-RL and Ac-RL with lipids were different in terms of insertion and molecular responses and were dependent on the lipid composition of model membranes. A more favorable insertion of Alk-RL than Ac-RL into lipid membranes is observed. Alk-RL forms more stable molecular assemblies than Ac-RL with phospholipids and sterols. At the molecular level, the presence of sterols tends to increase the RLs' interaction with lipid bilayers, with a fluidizing effect on the alkyl chains. Taken together, our findings suggest that the perception of these synthetic RLs at the membrane level could be related to a lipid-driven process depending on the organization of the membrane and the orientation of the RLs within the membrane and is correlated with the induction of early signaling responses in tobacco cells.

  • Nguyễn CH, Putaux J-L, Santoni G, et al. New nanoparticles obtained by co-assembly of amphiphilic cyclodextrins and nonlamellar single-chain lipids: Preparation and characterization. International Journal of Pharmaceutics 2017; 531: 444-456.
    Résumé : This work aimed at preparing new nanoscale assemblies based on an amphiphilic bio-esterified β-cyclodextrin (β-CD), substituted at the secondary face with n-decanoic fatty acid chains (β-CD-C10), and monoolein (MO) as new carriers for parenteral drug delivery. Stable binary (β-CD-C10/MO) and ternary (β-CD-C10/MO/stabilizer) nanoscale assemblies close to 100nm in size were successfully prepared in water by the solvent displacement method. The generated nanoparticles were fully characterized by dynamic light scattering, transmission electron microscopy, small-angle X-ray scattering, residual solvent analysis, complement activation and the contribution of each formulation parameter was determined by principal component analysis. The β-CD-C10 units were shown to self-organize into nanoparticles with a hexagonal supramolecular packing that was significantly modulated by the molar ratio of the constituents and the presence of a steric or electrostatic stabilizer (DOPE-PEG2000 or DOPA/POPA, respectively). Indeed, nanoparticles differing in morphology and in hexagonal lattice parameters were obtained while the co-existence of multiple mesophases was observed in some formulations, in particular for the β-CD-C10/MO/DOPA and β-CD-C10/MO/POPA systems. The mixed β-CD-C10/MO/DOPE-PEG2000 nanoparticles (49:49:2 in mol%) appeared to be the most suitable for use as a drug delivery system since they contained a very low amount of residual solvent and showed a low level of complement C3 activation.
    Mots-clés : Amphiphilic cyclodextrin, Complement activation, Monoolein, Nanoparticles, Small-angle X-ray scattering, Transmission electron microscopy.

  • Nguyen T-K-O, Jamali A, Grand E, et al. Phenylpropanoid profiling reveals a class of hydroxycinnamoyl glucaric acid conjugates in Isatis tinctoria leaves. Phytochemistry 2017; 144: 127-140.
    Résumé : The brassicaceous herb, Isatis tinctoria, is an ancient medicinal plant whose rosette leaf extracts have anti-inflammatory and anti-allergic activity. Brassicaceae are known to accumulate a variety of phenylpropanoids in their rosette leaves acting as antioxidants and a UV-B shield, and these compounds often have pharmacological potential. Nevertheless, knowledge about the phenylpropanoid content of I. tinctoria leaves remains limited to the characterization of a number of flavonoids. In this research, we profiled the methanol extracts of I. tinctoria fresh leaf extracts by liquid chromatography - mass spectrometry (LC-MS) and focused on the phenylpropanoid derivatives. We report the structural characterization of 99 compounds including 18 flavonoids, 21 mono- or oligolignols, 2 benzenoids, and a wide spectrum of 58 hydroxycinnamic acid esters. Besides the sinapate esters of malate, glucose and gentiobiose, which are typical of brassicaceous plants, these conjugates comprised a large variety of glucaric acid esters that have not previously been reported in plants. Feeding with (13)C6-glucaric acid showed that glucaric acid is an acyl acceptor of an as yet unknown acyltransferase activity in I. tinctoria rosette leaves. The large amount of hydroxycinnamic acid derivatives changes radically our view of the woad metabolite profile and potentially contributes to the pharmacological activity of I. tinctoria leaf extracts.
    Mots-clés : Brassicaceae, Glucaric acid, Glucosinolates, Hydroxycinnamic acid derivatives, Isatis tinctoria, LC-MS, Metabolite profiling, Phenylpropanoids.

  • Nivelle L, Hubert J, Courot E, et al. Cytotoxicity of Labruscol, a New Resveratrol Dimer Produced by Grapevine Cell Suspensions, on Human Skin Melanoma Cancer Cell Line HT-144. Molecules 2017; 22: 1940.
    Résumé : A new resveratrol dimer (1) called labruscol, has been purified by centrifugal partition chromatography of a crude ethyl acetate stilbene extract obtained from elicited grapevine cell suspensions of Vitis labrusca L. cultured in a 14-liter stirred bioreactor. One dimensional (1D) and two dimensional (2D) nuclear magnetic resonance (NMR) analyses including 1H, 13C, heteronuclear single-quantum correlation (HSQC), heteronuclear multiple bond correlation (HMBC), and correlation spectroscopy (COSY) as well as high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS) were used to characterize this compound and to unambiguously identify it as a new stilbene dimer, though its relative stereochemistry remained unsolved. Labruscol was recovered as a pure compound (&gt;93%) in sufficient amounts (41 mg) to allow assessment of its biological activity (cell viability, cell invasion and apoptotic activity) on two different cell lines, including one human skin melanoma cancer cell line HT-144 and a healthy human dermal fibroblast (HDF) line. This compound induced almost 100% of cell viability inhibition in the cancer line at a dose of 100 μM within 72 h of treatment. However, at all tested concentrations and treatment times, resveratrol displayed an inhibition of the cancer line viability higher than that of labruscol in the presence of fetal bovine serum. Both compounds also showed differential activities on healthy and cancer cell lines. Finally, labruscol at a concentration of 1.2 μM was shown to reduce cell invasion by 40%, although no similar activity was observed with resveratrol. The cytotoxic activity of this newly-identified dimer is discussed.
    Mots-clés : <em>Vitis labrusca </em>L., bioreactor, cytotoxic activity, fibroblasts, labruscol, melanoma, resveratrol.

  • Nivelle L, Hubert J, Courot E, et al. Anti-Cancer Activity of Resveratrol and Derivatives Produced by Grapevine Cell Suspensions in a 14 L Stirred Bioreactor. Molecules 2017; 22: 474.
    Résumé : In the present study, resveratrol and various oligomeric derivatives were obtained from a 14 L bioreactor culture of elicited grapevine cell suspensions (Vitis labrusca L.). The crude ethyl acetate stilbene extract obtained from the culture medium was fractionated by centrifugal partition chromatography (CPC) using a gradient elution method and the major stilbenes contained in the fractions were subsequently identified by using a 13C-NMR-based dereplication procedure and further 2D NMR analyses including HSQC, HMBC, and COSY. Beside δ-viniferin (2), leachianol F (4) and G (4′), four stilbenes (resveratrol (1), ε-viniferin (5), pallidol (3) and a newly characterized dimer (6)) were recovered as pure compounds in sufficient amounts to allow assessment of their biological activity on the cell growth of three different cell lines, including two human skin malignant melanoma cancer cell lines (HT-144 and SKMEL-28) and a healthy human dermal fibroblast HDF line. Among the dimers obtained in this study, the newly characterized resveratrol dimer (6) has never been described in nature and its biological potential was evaluated here for the first time. ε-viniferin as well as dimer (6) showed IC50 values on the three tested cell lines lower than the ones exerted by resveratrol and pallidol. However, activities of the first two compounds were significantly decreased in the presence of fetal bovine serum although that of resveratrol and pallidol was not. The differential tumor activity exerted by resveratrol on healthy and cancer lines was also discussed.
    Mots-clés : anticancer activity, bioreactor, fibroblasts, melanoma, phytostilbenes, resveratrol, Vitis labrusca.

  • Opfergelt S, Cornélis J-T, Houben D, Givron C, Burton KW, Mattielli N. The influence of weathering and soil organic matter on Zn isotopes in soils. Chemical geology. 2017; 466: 140-148.
    Résumé : Zinc is an essential micronutrient that is ultimately released during mineral weathering. In soils, organic matter plays a key role in influencing Zn partitioning and therefore on Zn biogeochemical cycling. Soil organic matter is partitioned between carbon that is more readily available for decomposition by microorganisms, and more stable carbon transiently preserved from decomposition. The role of the stable pool of soil organic matter on Zn biogeochemical cycling remains poorly understood. The pool of stable carbon is controlled by combination with mineral constituents or is material that is intrinsically resistant to decomposition. The Zn stable isotopes are fractionated by interactions between Zn and soil mineral and organic constituents. This study reports the Zn isotope composition of five Icelandic soil profiles derived from the same parent basalt and characterized by contrasting degrees of weathering and organic matter content (δ66Zn = + 0.10 ± 0.05 to + 0.35 ± 0.02‰), the distribution of reactive mineral constituents available to form associations with soil organic matter, and the amount of stable organic carbon. Throughout these soils, the δ66Zn isotope variations are little influenced by mineral constituents, but rather by soil organic matter content. These data suggest that a combination of organic matter accumulation and Zn loss by leaching is required to explain the observed decrease in Zn concentration in soils and lighter soil δ66Zn with increasing organic carbon content. These results suggest that the presence of stable organic carbon in soils provides a pool of light Zn, attributed to the Zn isotope signature of organic matter partially preserved from decomposition. Crucially, this stable organic carbon pool may also contribute to the formation of the light Zn isotope sink reported in organic-rich marine sediments, a key output required to explain the oceanic mass balance of Zn isotopes.

  • Ors M-eva, Randoux B, Selim S, et al. Cultivar-dependent partial resistance and associated defence mechanisms in wheat against Zymoseptoria tritici. 2017. (consulté 17 oct.2017).
    Résumé : Septoria tritici blotch caused by the fungus Zymoseptoria tritici is one of the most devastating foliar diseases of wheat. Knowledge regarding mechanisms involved in resistance against this disease is required to breed durable resistances. This study compared the expression of defence and pathogenicity determinants in three cultivars in semicontrolled culture conditions. The most susceptible cultivar, Alixan, presented higher necrosis and pycnidia density levels than Altigo, the most resistant one. In Premio, a moderately resistant cultivar, necrosis developed as in Alixan, while pycnidia developed as in Altigo. In noninfectious conditions, genes coding for PR1 (pr1), glucanase (gluc) and allene oxide synthase (aos) were constitutively expressed at a higher level in both Altigo and Premio than in Alixan, while chitinase2 (chit2), phenylalanine ammonia-lyase (pal), peroxidase (pox2) and oxalate oxidase (oxo) were expressed at a higher level in Premio only. Except for aos, all genes were induced in Alixan during the first steps of the symptomless infection phase. Only pox2, oxo, gluc and pal genes in Altigo and pal, chs and lox genes in Premio were up-regulated at some time points. Basal cultivar-dependent resistance against Z. tritici could therefore be explained by various gene expression patterns rather than high expression levels of given genes. During the necrotrophic phase, Z. tritici cell wall-degrading enzyme activity levels were lower in Altigo and Premio than in Alixan, and were associated more with pycnidia than with necrosis. Similar tissue colonization occurred in the three cultivars, suggesting an inhibition of the switch to the necrotrophic lifestyle in Altigo

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