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International audience; Methyl ricinoleate was functionalized using thiol-ene click chemistry in order to synthesize bio-based comb (co)poly(9-alkyl 12-hydroxystearate)s. The latter were then evaluated as Viscosity Index Improvers in a mineral based lubricant. While most of the poly(9-alkyl 12-hydroxystearate)s investigated behave as thickeners, copolyesters containing 15 to 25 wt. % of methyl 9-phenyl ethyl 12-hydroxystearate exhibit a Viscosity Index improver effect, interpreted to a limited solubility of these copolyesters. The effect of these polyesters on the oil viscosity-temperature (V-T) behavior was investigated in the dilute regime of n-dodecane used as a model solvent. An aggregation-disaggregation behavior was assumed to explain the V-T behavior observed with these (co)polyesters.

Climate change is challenging the resilience of grapevine (Vitis), one of the most important crops worldwide. Adapting viticulture to a hotter and drier future will require a multifaceted approach including the breeding of more drought-tolerant genotypes. In this study, we focused on plant hydraulics as a multi-trait system that allows the plant to maintain hydraulic integrity and gas exchange rates longer under drought. We quantified a broad range of drought-related traits within and across Vitis species, created in silico libraries of trait combinations, and then identified drought tolerant trait syndromes. By modeling the maintenance of hydraulic integrity of current cultivars and the drought tolerant trait syndromes, we identified elite ideotypes that increased the amount of time they could experience drought without leaf hydraulic failure. Generally, elites exhibited a trait syndrome with lower stomatal conductance, earlier stomatal closure, and a larger hydraulic safety margin. We demonstrated that, when compared with current cultivars, elite ideotypes have the potential to decrease the risk of hydraulic failure across wine regions under future climate scenarios. This study reveals the syndrome of traits that can be leveraged to protect grapevine from experiencing hydraulic failure under drought and increase drought tolerance.

Context Understanding plant resilience and adaptation to drought is a major challenge in crop and forest sciences. Several methods have been developed to assess the vulnerability to xylem embolism. The in situ flow centrifuge (or cavitron) is the fastest technique allowing to characterise this trait for plants having vessel lengths shorter than the rotor size. Aims We present (i) a series of changes to the earlier cavitron design, aimed at improving the accuracy and speed of measurement through automated operations, and (ii) a new development through the design of a large diameter rotor expanding the range of species that can be measured. Methods Both hardware and software modifications to the original design have been developed. In order to avoid artefacts caused by cut open vessels, a centrifuge with a large rotor (1 m) has been developed, and vulnerability curves obtained with this new device were compared with those obtained using reference methods. Results The new set-up expands the range of conductance measurable with a cavitron and enables it to accurately determine the absolute value of conductivity even for species having very low hydraulic conductivity. The large rotor cavitron shows good agreement with the reference techniques for conifers and diffuse-porous species but also for ring-porous species having long vessels. Conclusion The set-up described in this manuscript provides a faster, safer and more accurate method to construct vulnerability curves, compared to the original cavitron design, and extends the measurement capabilities to new species that are difficult to measure to date. Key message Recent improvements to cavitron setup enable to measure xylem vulnerability curves for an expanded number of plant species, with longer vessels or lower hydraulic conductivity.

International audience; Questions Tree diversity is key to the functioning of forest ecosystems. However, which components of tree diversity are responsible for tree diversity effects on associated organisms, and in which context, is poorly understood. Location ORPHEE Experimental site, Cestas-Pierroton in the southwest of France. Methods We used a large-scale tree diversity experiment in which we controlled water availability by an irrigation treatment to address tree diversity and water stress effects on the diversity and height of forest understorey vegetation. We assessed the species richness and height of understorey vegetation in irrigated and non-irrigated 20 m x 20 m plots, either being monocultures ofPinus pinaster,Betula pendulaorQuercus robur, or either mixtures of two to five species amongPinus pinaster,Betula pendula,Quercus robur,Quercus ilexandQuercus pyrenaica. Results Tree species composition, i.e. the proportion of birch or pine, had a significant effect on understorey plant assemblage, species richness and diversity. The proportion of the fast-growing deciduous angiospermBetula pendulawas negatively correlated to understorey plant richness and diversity, and positively correlated with understorey vegetation height. Understorey vegetation was higher in irrigated plots than in non-irrigated plots, but irrigation had no clear effect on the species richness, diversity or composition of understorey plant assemblages. Conclusions Forest tree species composition and in particular the relative proportions of different tree species had stronger effects on understorey plants than tree species richness per se. These effects were consistent across irrigation treatments. Even in young forest plantations, effects of tree mixture on understorey vegetation may be observed and seem mainly driven by the functional type of tree in the canopy and initial dynamics of plant regeneration in planted forests.

The European Beech is the dominant climax tree in most regions of Central Europe and valued for its ecological versatility and hardwood timber. Even though a draft genome has been published recently, higher resolution is required for studying aspects of genome architecture and recombination. Here, we present a chromosome-level assembly of the more than 300 year-old reference individual, Bhaga, from the Kellerwald-Edersee National Park (Germany). Its nuclear genome of 541 Mb was resolved into 12 chromosomes varying in length between 28 and 73 Mb. Multiple nuclear insertions of parts of the chloroplast genome were observed, with one region on chromosome 11 spanning more than 2 Mb which fragments up to 54,784 bp long and covering the whole chloroplast genome were inserted randomly. Unlike in Arabidopsis thaliana, ribosomal cistrons are present in Fagus sylvatica only in four major regions, in line with FISH studies. On most assembled chromosomes, telomeric repeats were found at both ends, while centromeric repeats were found to be scattered throughout the genome apart from their main occurrence per chromosome. The genome-wide distribution of SNPs was evaluated using a second individual from Jamy Nature Reserve (Poland). SNPs, repeat elements and duplicated genes were unevenly distributed in the genomes, with one major anomaly on chromosome 4. The genome presented here adds to the available highly resolved plant genomes and we hope it will serve as a valuable basis for future research on genome architecture and for understanding the past and future of European Beech populations in a changing climate.

International audience; 1. Xylem hydraulic safety and efficiency are key traits determining tree fitness in a warmer and drier world. While numerous plant hydraulic studies have focused on branches, our understanding of root hydraulic functioning remains limited, although roots control water uptake, influence stomatal regulation and have commonly been considered as the most vulnerable organ along the hydraulic pathway.2. We investigated 11 traits related to xylem safety and efficiency along the hydraulic pathway in four temperate broad-leaved tree species.3. Continuous vessel tapering from coarse roots to stems and branches caused considerable reduction in hydraulic efficiency. Wood density was always lowest in roots, but did not decline linearly along the flow path. In contrast, xylem embolism resistance (P-50) did not differ significantly between roots and branches, except for one species. The limited variation in xylem safety between organs did not adequately reflect the corresponding reductions in vessel diameter (by similar to 70%) and hydraulic efficiency (by similar to 85%). Although we did not observe any trade-off between xylem safety and specific conductivity, vessel diameter, vessel lumen fraction and wood density were related to embolism resistance, both across and partly within organs.4. We conclude that coarse roots are not highly vulnerable to xylem embolism as commonly believed, indicating that hydraulic failure during soil drying might be restricted to fine roots. A free Plain Language Summary can be found within the Supporting Information of this article.

INISEFOR Swietenia species are the most valuable American tropical timbers and have been heavily overexploited for decades. The three species are listed as either vulnerable or endangered by IUCN and are included on Appendix II of CITES, yet illegal exploitation continues. Here, we used restriction associated DNA sequencing to develop a new set of 120 SNP markers for Swietenia sp., suitable for MassARRAY®iPLEX™ genotyping. These markers can be used for population genetic studies and timber tracking purposes. Las especies de Swietenia son las maderas tropicales estadounidenses más valiosas y han sido muy sobreexplotadas durante décadas. los Tres especies están incluidas como vulnerables o en peligro de extinción por la UICN y están incluidas en el Apéndice II de la CITES, pero son ilegales. la explotación continúa. Aquí, utilizamos la secuenciación de ADN asociada a la restricción para desarrollar un nuevo conjunto de 120 marcadores SNP para Swietenia sp., Adecuada para el genotipado MassARRAY®iPLEX ™. Estos marcadores se pueden utilizar para estudios genéticos de poblaciones. y seguimiento de la madera. As espécies de Swietenia são as madeiras tropicais americanas mais valiosas e têm sido fortemente superexploradas por décadas. As três espécies estão listadas como vulneráveis ​​ou em perigo pela IUCN e estão incluídas no Apêndice II da CITES, mas a exploração ilegal continua. Aqui, usamos o sequenciamento de DNA associado à restrição para desenvolver um novo conjunto de 120 marcadores SNP para Swietenia sp., Adequado para genotipagem MassARRAY®iPLEX ™. Esses marcadores podem ser usados ​​para estudos de genética populacional e fins de rastreamento de madeira. Thünen Institute of Forest Genetics, Germany Instituto Nacional de Pesquisas da Amazônia, Brazil Universidad Nacional, Costa Rica Centre for Ecology & Hydrology, United Kingdom Instituto Florestal de São Paulo, Brazil University of Bordeaux, France Mahogany for the Future Inc., USA Bush Estate, United Kingdom Instituto de Investigación y Servicios Forestales

International audience; Transcriptome sequencing was used for the development of single nucleotide polymorphisms (SNP) for the red gorgonian (Paramuricea clavata). A total of 20,736 SNPs were identified, and 1718 had a coverage of over 100 reads. Of the 480 SNPs tested, 347 SNPs were successfully genotyped at 95 samples from the NW Mediterranean using a MassARRAY System. This set of markers will be of great value for population genetics and phylogeography.

International audience; The effect of temperature during the wood drying process was studied in order to prevent resin exudation on the surface of maritime pine wood boards used as outdoor siding. Resin exudation is a crucial concern for the maritime pine industry, as it may strongly decrease the wood aesthetics during outdoor exposure. In a previous study, it was observed that the thermal history of rosin can change the softening point temperature of its compounds. Using heat treatment, this temperature can shift from about 40 °C–60 °C, which corresponds to the maximal surface temperature of an unpainted wood siding in a temperate climatic zone. In the present study, green wood boards from various trees were dried at various temperatures (60 °C, 90 °C, 120 °C and 150 °C) and directly evaluated after drying regarding their resistance to exudation. To perform this test, an infrared radiative system was developed in order to recreate summer outdoor conditions. The results show the absence of exudation for boards dried at high-temperature (150 °C). In order to better understand the effects of a heat treatment on resin compounds inside wood, they were studied using HPLC after extraction. The analysis was compared to a standard rosin used in a previous study showing strong similarity. These results highlight some new effects of high temperature drying which may offer new strategies for reducing resin exudation on outdoor wood siding by fixing the resin compounds inside the wood.

International audience; In order to move away from traditional petrochemical-based polymer materials, it is imperative that new monomer systems be sought out based on renewable resources. In this work, the synthesis of a functional terpene-containing acrylate monomer (tetrahydrogeraniol acrylate, THGA) is reported. This monomer was polymerized in toluene and bulk via free-radical polymerizations, achieving high conversion and molecular weights up to 278 kg·mol–1. The synthesized poly(THGA) shows a relatively low Tg (−46 °C), making it useful as a replacement for low Tg acrylic monomers, such as the widely used n-butyl acrylate. RAFT polymerization in toluene ([M]0 = 3.6 mol·L–1) allowed for the well-controlled polymerization of THGA with degrees of polymerization (DPn) from 25 to 500, achieving narrow molecular weight distributions (D̵ ≈ 1.2) even up to high conversions. At lower monomer concentrations ([M]0 = 1.8 mol·L–1), some evidence of intramolecular chain transfer to polymer was seen by the detection of branching (arising from propagation of midchain radicals) and terminal double bonds (arising from β-scission of midchain radicals). Poly(THGA) was subsequently utilized for the synthesis of poly(THGA)-b-poly(styrene)-b-poly(THGA) and poly(styrene)-b-poly(THGA)-b-poly(styrene) triblock copolymers, demonstrating its potential as a component of thermoplastic elastomers. The phase separation and mechanical properties of the resulting triblock copolymer were studied by atomic force microscopy and rheology.

Hydraulic failure has been extensively studied during drought-induced plant dieback, but its role in plant-pathogen interactions is under debate. During esca, a grapevine (Vitis vinifera) disease, symptomatic leaves are prone to irreversible hydraulic dysfunctions but little is known about the hydraulic integrity of perennial organs over the short- and long-term. We investigated the effects of esca on stem hydraulic integrity in naturally infected plants within a single season and across season(s). We coupled direct (ks) and indirect (kth) hydraulic conductivity measurements, and tylose and vascular pathogen detection with in vivo X-ray microtomography visualizations. Xylem occlusions (tyloses) and subsequent loss of stem hydraulic conductivity (ks) occurred in all shoots with severe symptoms (apoplexy) and in more than 60% of shoots with moderate symptoms (tiger-stripe), with no tyloses in asymptomatic shoots. In vivo stem observations demonstrated that tyloses occurred only when leaf symptoms appeared, and resulted in more than 50% loss of hydraulic conductance in 40% of symptomatic stems, unrelated to symptom age. The impact of esca on xylem integrity was only seasonal, with no long-term impact of disease history. Our study demonstrated how and to what extent a vascular disease such as esca, affecting xylem integrity, could amplify plant mortality through hydraulic failure.

Esters constitute a broad family of volatile compounds impacting the organoleptic properties of many beverages, including wine and beer. They can be classified according to their chemical structure. Higher alcohol acetates differ from fatty acid ethyl esters, whereas a third group, substituted ethyl esters, contributes to the fruitiness of red wines. Derived from yeast metabolism, the biosynthesis of higher alcohol acetates and fatty acid ethyl esters has been widely investigated at the enzymatic and genetic levels. As previously reported, two pairs of esterases, respectively encoded by the paralogue genes ATF1 and ATF2, and EEB1 and EHT1, are mostly involved in the biosynthesis of higher alcohol acetates and fatty acid ethyl esters. These esterases have a moderate effect on the biosynthesis of substituted ethyl esters, which depend on mono-acyl lipases encoded by MGL2 and YJU3. The functional characterization of such genes helps to improve our understanding of substituted ester metabolism in the context of wine alcohol fermentation. In order to evaluate the overall sensorial impact of esters, we attempted to produce young red wines without esters by generating a multiple esterase-free strain (Δatf1, Δatf2, Δeeb1, and Δeht1). Surprisingly, it was not possible to obtain the deletion of MGL2 in the Δatf1/Δatf2/Δeeb1/Δeht1 background, highlighting unsuspected genetic incompatibilities between ATF1 and MGL2. A preliminary RNA-seq analysis depicted the overall effect of the Δatf1/Δatf2/Δeeb1/Δeht1 genotype that triggers the expression shift of 1124 genes involved in nitrogen and lipid metabolism, but also chromatin organization and histone acetylation. These findings reveal unsuspected regulatory roles of ester metabolism in genome expression for the first time.

Nighttime transpiration has been previously reported as a significant source of water loss in many species; however, there is a need to determine if this trait plays a key role in the response to drought. This study aimed to determine the magnitude, regulation and relative contribution to whole plant water‐use, of nighttime stomatal conductance (g night) and transpiration (E night) in grapevine (Vitis vinifera L.). Our results showed that nighttime water loss was relatively low compared to daytime transpiration, and that decreases in soil and plant water potentials were mainly explained by daytime stomatal conductance (g day) and transpiration (E day). Contrary to E day, E night did not respond to VPD and possible effects of an innate circadian regulation were observed. Plants with higher g night also exhibited higher daytime transpiration and carbon assimilation at midday, and total leaf area, suggesting that increased g night may be linked with daytime behaviors that promote productivity. Modeling simulations indicated that g night was not a significant factor in reaching critical hydraulic thresholds under scenarios of either extreme drought, or time to 20% of soil relative water content. Overall, this study suggests that g night is not significant in exacerbating the risk of water stress and hydraulic failure in grapevine., Our study demonstrates that in grapevine (Vitis vinifera L.), nighttime water loss is not significant in exacerbating the risk of water stress, and in addition, we offer evidence that it may be positively linked to daytime productivity.

International audience; To better study and manage chestnut trees and species, we identified nuclear single nucleotide polymorphism (SNP) markers using restriction-associated DNA sequencing. Out of 343 loci tested, 68 SNP markers were selected that withhold stringent quality criteria such as quasi-systematic amplification across species and Mendelian segregation in both purebred and hybrid individuals. They provide sufficient power for species, hybrids and backcross characterization as well as for clonal identification, as shown by a comparison with single sequenced repeat (SSR) loci.

Background Natural Saccharomyces cerevisiae yeast strains exhibit very large genotypic and phe-notypic diversity. Breeding programs taking advantage of this characteristic, are widely used for yeast selection in the wine industry, especially in the recent years when winemakers need to adapt their production to climate change. The aim of this work was to evaluate a Marker Assisted Se-lection (MAS) program to improve malic acid consumption capacity of Saccharomyces cerevisiae in grape juice. Methods Optimal individuals of two unrelated F1-hybrids were crossed to get a new genetic background carrying many “malic consumer” loci. Then, eleven QTLs already identified were used for implementing the MAS breeding program. Results By this way, extreme individuals able to consume more than 70% of malic acid in grape juice were selected. These individuals were tested in different enological matrixes and compared to their original parental strains. They greatly reduced the malic acid content at the end of alcoholic fermentations, they appeared to be robust to the environment and accelerate the ongoing of malo-lactic fermentations by Oenococcus oeni. Conclusions This study illustrates how MAS can be efficiently used for selecting industrial Saccharomyces cerevisiae strains with outlier properties for winemaking.

International audience; he aim of this study was to set up a chemometric procedure using near infrared spectra acquired with a low-cost handheld spectrometer (SCiO), to quantify the main chemical components of maritime pine (Pinus pinaster) resin, in view of using the SCiO as a quality control tool for the tapping industry. This study was carried out on samples of resin harvested during the summer of 2018, in Biscarosse, France. Spectral data were collected using both an SCiO, and a benchtop spectrometer (MultiPurpose Analyzer I) for baseline reference . The rates of turpentine and rosin were quantified by gas chromatography (turpentine composition), liquid chromatography (rosin composition), and a ventilated oven . The chemometric procedure involved spectra preprocessing and relevant subset selection with the DUPLEX algorithm. Lastly, Partial Least Squares (PLS) regression was used to calibrate the models. The quantitative predictive ability of the resulting PLS regression models was evaluated via Ratio of standard error of Performance to standard Deviation (RPD) statistics. The results show that spectra preprocessing enhanced the quantitative predictive ability. For MPA I, RPD > 3.5, which expresses some very good to excellent quantitative predictions of the models. For SCiO, RPD > 2.5, which expresses a good quantitative predictive ability for quality control purposes. Thus, RPD statistics confirm that an SCiO could be used as a quality control tool.

International audience; Abstract In order to promote convenient strategies for the valorization of Aucoumea klaineana Pierre (Okoume) plywood and sawmill wastes industry in the fields of adhesives and composites, the total phenolic content of Okoume bark, sapwood and heartwood was measured. The molecular structure of tannins extracted from the bark was determined by Matrix Assisted Laser Desorption/Ionization Time-Of-Flight (Maldi-ToF) mass spectrometry and Fourier transform infrared spectroscopy (FTIR). The total phenolic content displayed significant difference (p = 0.001) between the bark, sapwood and heartwood which decreased as follows: 6 ± 0.4, 2 ± 0.8 and 0.7 ± 0.1% respectively. The pro-anthocyanidins content was also significantly different (p = 0.01) among the three wood wastes, and the bark was the richest in condensed tannins (4.2 ± 0.4%) compared to the sapwood (0.5 ± 0.1%) and heartwood (0.2 ± 0.2%). Liquid chromatography coupled mass spectroscopy (LC-MS) and Maldi-ToF analysis of the bark showed for the first time that Okoume condensed tannins are fisetinidin, gallocatechin and trihydroxyflavan based monomers and complex polymers obtained with glycosylated units. No free catechin or robitinidin units were detected, whereas distinctive dihydroxy or trihydroxyflavan-3-benzoate dimers were observed in the investigated condensed tannin extracts. FTIR analysis showed the occurrence of glucan- and mannan-like sugars in the condensed tannins, and Maldi-ToF highlighted that these sugars should account for ten glycosylated units chemically bonded with two fisetinidins and one gallocatechin trimer. The condensation of these polyphenols with formaldehyde led to Stiasny numbers of 83.3, 73.3 and 53.3% for the bark, sapwood and heartwood, respectively.

Adapting agriculture to climate change is driving the need for the selection and breeding of drought-tolerant crops. The aim of this study was to identify key drought tolerance traits and determine the sequence of their water potential thresholds across three grapevine cultivars with contrasting water use behaviors, Grenache, Syrah, and Semillon. We quantified differences in water use between cultivars and combined this with the determination of other leaf-level traits (e.g. leaf turgor loss point, π TLP), leaf vulnerability to embolism (P50), and the hydraulic safety margin (HSM P50). Semillon exhibited the highest maximum transpiration (Emax), and lowest sensitivity of canopy stomatal conductance (Gc) to vapor pressure deficit (VPD), followed by Syrah and Grenache. Increasing Emax was correlated with more negative water potential at which stomata close (Pgs90), π TLP, and P50, suggesting that increasing water use is associated with hydraulic traits allowing gas exchange under more negative water potentials. Nevertheless, all the cultivars closed their stomata prior to leaf embolism formation. Modeling simulations demonstrated that despite a narrower HSM, Grenache takes longer to reach thresholds of hydraulic failure due to its conservative water use. This study demonstrates that the relationships between leaf hydraulic traits are complex and interactive, stressing the importance of integrating multiple traits in characterizing drought tolerance., The relationships between traits including stomatal regulation, leaf embolism thresholds, and survival time under drought are complex and interactive, stressing the importance of integrating multiple traits in characterizing drought tolerance.

Aucoumea klaineana Pierre (Okoume) tannins were extracted by an artisanal maceration method in the presence of acetone/water used as solvent. The tannins obtained from the sapwood and heartwood and characterized by Maldi-ToF and FTIR did not present any differences regarding their type of oligomers. Tannins were more abundant in sapwood than in heartwood, but in both of them, fisetinidin and gallocatechin were the main monomers of condensed tannin. A low content of trihydroxyflavan monomer was identified, whereas non-glycosylated condensed tannins up to seven oligomers were found in high content in Okoume. These results, which revealed for the first time the chemical structure of Okoume condensed tannins showed the presence of a glycosylated condensed tannin series up to six carbohydrate residues attached to 2xgallocatechin-1xcatechin flavonoids.

Background and Aims Highly controlled experiments document that plant genetic diversity and relatedness can shape herbivore communities and patterns of herbivory. Evidence from the field is, however, scarce and inconsistent. We assessed whether a genetic signal underlying herbivory can be detected in oak woodlands when accounting for variation at smaller (within-tree) and larger (among-stand) scales. Methods We tested relationships between tree genetic relatedness, leaf chemical defences and insect herbivory for different canopy layers in 240 trees from 15 pedunculate oak (Quercus robur) forest stands. We partitioned sources of variability in herbivory and defences among stands, individuals and branches. Key Results Leaf defences, insect herbivory and their relationship differed systematically between the upper and the lower tree canopy. When accounting for this canopy effect, the variation explained by tree genetic relatedness rose from 2.8 to 34.1 % for herbivory and from 7.1 to 13.8 % for leaf defences. The effect was driven by markedly stronger relationships in the upper canopy. Conclusions Our findings illustrate that considerable effects of the host plant genotype on levels of leaf chemical defences and associated insect herbivory can be detected in natural tree populations when within-individual variation is properly accounted for.

The Pacific oyster, Crassostrea gigas, was voluntarily introduced from Japan and British Columbia into Europe in the early 1970s, mainly to replace the Portuguese oyster, Crassostrea angulata, in the French shellfish industry, following a severe disease outbreak. Since then, the two species have been in contact in southern Europe and, therefore, have the potential to exchange genes. Recent evolutionary genomic works have provided empirical evidence that C. gigas and C. angulata exhibit partial reproductive isolation. Although hybridization occurs in nature, the rate of interspecific gene flow varies across the genome, resulting in highly heterogeneous genome divergence. Taking this biological property into account is important to characterize genetic ancestry and population structure in oysters. Here, we identified a subset of ancestry-informative makers from the most differentiated regions of the genome using existing genomic resources. We developed two different panels in order to (i) easily differentiate C. gigas and C. angulata, and (ii) describe the genetic diversity and structure of the cupped oyster with a particular focus on French Atlantic populations. Our results confirm high genetic homogeneity among Pacific cupped oyster populations in France and reveal several cases of introgressions between Portuguese and Japanese oysters in France and Portugal.

Key Message : Needle anatomic plasticity enables fast-growing maritime pine trees to cope with water limitations by enhancing both water-use efficiency and embolism resistance.Abstract : Maritime pine is a major forest tree grown for wood production in Southern Europe. A breeding program for the selection of fast-growing varieties was established in the 1960s, in France. In the context of climate change, the magnitude of phenotypic plasticity is a key issue for the prediction of putative decreases in productivity in the improved genetic material. We characterized the phenotypic plasticity of anatomical and physiological traits in two families with contrasting growth rates, under different water regimes, at the juvenile stage. An analysis of 38 traits showed that the fastest growing family had the greatest phenotypic plasticity for morphological, anatomic, chemical and physiological traits, enabling it to increase its water use efficiency and embolism resistance in response to water deficit. The observed modifications to the extravascular (proportion of spongy parenchyma in needles) and vascular (xylem in the needles and stem) compartments in response to water constraints were consistent with a higher water use efficiency and greater embolism resistance. The ability to optimize meresis and auxesis according to environmental conditions during needle development could be related to growth performance over time in different environmental conditions. These results suggest that selection for growth in maritime pine leads to the selection of individuals with greater phenotypic plasticity related to higher performances in non-limited conditions.

International audience; AbstractKey messageA moderate genetic diversity, the absence of a significant genetic differentiation between wild and cultivated stands and a highly admixed genetic structure of sweet chestnut with two main clusters were observed in France using two different data sets with 10 and 18 microsatellites.ContextRenewed interest in European chestnut in France is focused on finding locally adapted populations partially resistant to ink disease and identifying local landraces.AimsWe genotyped trees to assess (i) the genetic diversity of wild and cultivated chestnut across most of its range in France, (ii) their genetic structure, notably in relation with the sampled regions, and (iii) to a lesser extent the relations between French chestnuts with 10 cultivated chestnuts from the Northwest of Spain that were previously classified in the Iberian or Italian groups.MethodsA total of 693 trees in 16 sampling regions in France were genotyped at 24 SSRs and 1401 trees in 17 sampling regions at 13 SSRs.ResultsGenetic diversity was moderate in most sampling regions, with redundancy between them. No significant differentiation was found between wild and cultivated chestnut. A genetic structure analysis with no a priori information found a low yet significant structure and identified two clusters at 18 SSRs. One cluster gathers trees from south-east France and Corsica (RPP1), and another cluster gathers trees from all other sampled regions (RPP2). A substructure was detected at 10 SSRs suggesting differentiation within both RPP1 and RPP2. RPP1 was split between south-east France and Corsica. RPP2 was split between northwest France, Aveyron, Pyrenees, and a last cluster gathering individuals from several other regions.ConclusionThe genetic structure within and between our sampling regions is likely the result of natural events (recolonization after the last glaciation) and human activities (migration and exchanges). These advances on our knowledge of chestnut genetic diversity and structure will benefit conservation and help our local partners’ valorization efforts.

[Key message]: In our study of colonisation of abandoned farmland byJuniperus thurifera L., environmental and geographic distances were stronger drivers of functional differentiation among trees than genetic distance and tree intrinsic features. However, these effects varied both along the colonisation gradient and across predictors’ values, highlighting the complexity of the conditions under which functional diversity of forests is maximised. Context: Forest expansion after land abandonment is changing Mediterranean landscapes, but the underlying ecological and evolutionary processes remain poorly understood., [Aims]: We evaluated whether forest expansion reduces within-stand tree functional distances and whether its environmental, geographical and genetic drivers vary along the expansion gradient., [Methods]: We sampled Juniperus thurifera in mature, transition and expanding stands along a colonisation gradient in Spain. We measured functional traits, genetic relatedness, surrounding vegetation cover and intrinsic features (size, phytosanitary status) on trees. We calculated within-stand pairwise functional distances and quantified the effects of genetic relatedness, geographic distance, vegetation cover and intrinsic tree features., [Results]: Functional and genetic distances showed no consistent patterns along the expansion gradient. Functional distance was unrelated with genetic distance and strongly driven by geographic distance, likely representing unmeasured environmental factors. Vegetation cover and intrinsic tree features affected functional traits in transition and expanding stands. The effects on functional distance changed across predictors’ values., [Conclusion]: The role of environmental and geographic factors on tree functional divergence varied along the farmland colonisation gradient, while we did not detect effects of genetic distance. Accounting for this context-dependence and for non-linear effects on functional traits can improve our understanding and management of forest expansions., This study was funded by the grants SPONFOREST (BiodivERsA3-2015-58, PCIN-2016-055, financed by the Spanish Research Agency, AEI and the Spanish Ministry of Economy, Industry and Competitiveness, MINECO), COMEDIAS (MINECO, CGL2017-83170-R) and REMEDINAL TE (Ref. TE-CM.S2018/EMT-4338, 2019-2023-Comunidad de Madrid).

International audience; Climate change threatens food security, and plant science researchers have investigated methods of sustaining crop yield under drought. One approach has been to overproduce abscisic acid (ABA) to enhance water use efficiency. However, the concomitant effects of ABA overproduction on plant vascular system functioning are critical as it influences vulnerability to xylem hydraulic failure. We investigated these effects by comparing physiological and hydraulic responses to water deficit between a tomato (Solanum lycopersicum) wild type control (WT) and a transgenic line overproducing ABA (sp12). Under well-watered conditions, the sp12 line displayed similar growth rate and greater water use efficiency by operating at lower maximum stomatal conductance. X-ray microtomography revealed that sp12 was significantly more vulnerable to xylem embolism, resulting in a reduced hydraulic safety margin. We also observed a significant ontogenic effect on vulnerability to xylem embolism for both WT and sp12. This study demonstrates that the greater water use efficiency in the tomato ABA overproducing line is associated with higher vulnerability of the vascular system to embolism and a higher risk of hydraulic failure. Integrating hydraulic traits into breeding programmes represents a critical step for effectively managing a crop's ability to maintain hydraulic conductivity and productivity under water deficit.

Chestnut species have large ecological, cultural and economic importance. Developing genetic markers for these species is of interest for conservation, breeding or evolutionary studies. We designed 192 primer pairs targeting microsatellites detected in the Castanea mollissima reference genome and tested them on C. sativa and C. crenata. We PCR amplified 3 × 50 microsatellites in 106 chestnut trees. Microhaplotype calling accounting for all polymorphisms resulted in a total of 98 high confidence polymorphic markers. Mean number of haplotypes per marker was 9.05 with respectively 71%, 12% and 16% of the variation corresponding to microsatellite variation in repeats number, SNP within the repeat motif and SNP or INDEL in the flanking sequence. Overall, the simple protocol described here generated a powerful multilocus genetic dataset for chestnut genetic investigations.

We used double digest restriction site associated DNA sequencing (ddRAD) to develop new geographically informative nuclear SNP loci in Quercus robur and Quercus petraea. Genotypes derived from sequence data of 95 individuals covering the distribution range of the species were analysed to select geographically informative and polymorphic loci within Russia and Germany. We successfully screened a selected set of 119 loci on a MassARRAY® iPLEX™ platform on 190 individuals from 19 locations in Russia. The newly developed loci will be useful for genetic studies over the whole distribution range of both species.

International audience; The temperature of pine rosin softening point was studied to better understand the phenomenon of resin exudation on the surface of pine boards. This problem may decrease strongly the aesthetical performance of wood used outside and is an important concern for the industry. To perform a reliable measurement of rosin properties with a small amount of sample, differential scanning calorimetry (DSC) and thermo mechanical analysis (TMA) techniques were investigated and the results compared. DSC curves on industrial rosin and acetone rosin extractives from maritime pine show a behavior similar to a glass transition in polymers. TMA measurements carried out on the same industrial rosin showed that the softening point is in the midpoint of the transition phase observed by DSC. The softening point temperature is about 45 °C for industrial rosin and about 50 °C for rosin extractives from maritime pine boards. These values are significantly lower than those usually found on other rosins measured by the ASTM E28-14 standard using the ring-and-ball method. When using heat treatment, it was observed for the first time that the thermal history of the sample can change its softening point temperature. With these results, it could be possible to develop a new strategy to reduce rosin exudation for exterior wood siding.

Trigger-free self-assembly of oligo(ethylene glycol) OEG-based responsive microgels is for the first time described via simple solvent evaporation process at skin temperature and ambient pressure. This unique behaviour is attributed to the intrensic OEG microgel structure and properties due to a negative glass transition temperature, a high adhesion energy, an elastic mechanical property and a high interpenetration of microgels, combined in an all-in-one building block. Furthermore, the encapsulation of magnetic nanoparticles (NPs) into the OEG-based microgels introduced interferential photonic and magnetic properties to the films. These microgels exhibiting simultaneously spontaneous film-forming and colored photonic properties open up the development of a unique easy-to-handle material for cosmetic applications, but also smart patches for healthcare or medicine. Keywords: Oligo(ethylene glycol)-based microgel, Force spectroscopy, Adhesion, Self-assembly, Self-supported film

International audience; Herein, cosmetic active molecule controlled encapsulation and release from multi-responsive oligo(ethylene glycol)-based biocompatible microgels are reported. The pH-responsiveness and pH-sensitive thermal-behavior of the microgel synthesized in different cosmetic buffered media has been demonstrated. The effective encapsulation of four different cosmetic active molecules (two hydrophilic and two hydrophobic) via short-distance local hydrophobic interactions and hydrogen-bonding interactions between the -OH groups of active molecules and ether oxygens of loaded-microgel particles has been studied by Diffusion Ordered Spectroscopy NMR (DOSY-NMR) and Nuclear Overhauser Enhancement Spectroscopy (NOESY-NMR) for the first time. In vitro release profiles have shown that cosmetic active molecule release can be controlled by the pH and temperature of the medium as well as by the medium hydrophobicity. In addition, under those conditions where microgel particles are swollen, the cosmetic active molecule release is controlled by Fickian diffusion and Case-II transport, the diffusional process being dominant. These results indicate that multi-responsive oligo(ethylene glycol)-based microgels are new potential vehicles to design cosmetic active delivery systems.

International audience; Pharmaceutical industry effluents are complex and highly variable in time. Assessing the efficiency of a pharmaceutical industry wastewater treatment plant (WWTP) and the resulting decrease in effluent toxicity and ecological risk is thus not straightforward. We set up an original in situ pilot directly connected to a pharmaceutical WWTP to monitor the chronic toxicity of successive effluents using natural periphytic biofilms. Their structural and functional responses to effluent exposure were assessed by combining (i) a molecular approach to characterize the bacterial and diatom diversity and (ii) functional measurements of photosynthetic and enzyme activities. Effluent contamination by pharmaceuticals strongly decreased after the quaternary treatment (activated carbon). Most of the structural biological characteristics improved with cumulative WWTP treatment (bacterial diversity, microbial genetic structure, and biological diatom index), showing community recovery along the treatment process. However, functional parameters did not show clear links with treatment steps, suggesting that microbial activities were not solely driven by pharmaceuticals produced during the experimental period. Operationally, this type of pilot system offers a useful tool for biomonitoring approaches and offers new approaches for industrial managers to assess the ecological risk of production effluents in receiving water.

International audience; *Hydraulic failure explains much of the increased rates of drought-induced tree mortality around the world, underlining the importance of understanding how species distributions are shaped by their vulnerability to embolism. Here we determined which physiological traits explain species climatic limits among temperate rainforest trees in a region where chronic water limitation is uncommon.*We quantified the variation in stem embolism vulnerability and leaf turgor loss point among 55 temperate rainforest tree species in New Zealand and tested which traits were most strongly related to species climatic limits.*Leaf turgor loss point and stem P50 (tension at which hydraulic conductance is at 50% of maximum) were uncorrelated. Stem P50 and hydraulic safety margin were the most strongly related physiological traits to climatic limits among angiosperms, but not among conifers. Morphological traits such as wood density and leaf dry matter content did not explain species climatic limits.*Stem embolism resistance and leaf turgor loss point appear to have evolved independently. Embolism resistance is the most useful predictor of the climatic limits of angiosperm trees. High embolism resistance in the curiously overbuilt New Zealand conifers suggests that their xylem properties may be more closely related to growing slowly under nutrient limitation and to resistance to microbial decomposition.

Application of high-throughput sequencing technologies to microsatellite genotyping (SSRseq) has been shown to remove many of the limitations of electrophoresis-based methods and to refine inference of population genetic diversity and structure. We present here a streamlined SSRseq development workflow that includes microsatellite development, multiplexed marker amplification and sequencing, and automated bioinformatics data analysis. We illustrate its application to five groups of species across phyla (fungi, plant, insect and fish) with different levels of genomic resource availability. We found that relying on previously developed microsatellite assay is not optimal and leads to a resulting low number of reliable locus being genotyped. In contrast,de novo ad hocprimer designs gives highly multiplexed microsatellite assays that can be sequenced to produce high quality genotypes for 20 to 40 loci. We highlight critical upfront development factors to consider for effective SSRseq setup in a wide range of situations. Sequence analysis accounting for all linked polymorphisms along the sequence, quickly generates a powerful multi-allelic haplotype-based genotypic dataset, calling to new theoretical and analytical frameworks to extract more information from multi-nucleotide polymorphism marker systems.

International audience; The interactions between rosin and turpentine during the drying process were studied to better understand wood pine resin exudation in outdoor use under solar heat. Resin exudation is an important concern for industrials, as it may strongly decrease the wood’s aesthetic value. Resin viscosity change with temperature variations induced an alteration in the resin’s appearance from 65 °C. Resin, which is opaque at ambient temperature, becomes translucent above 65 °C. Resin samples were dried at temperatures respectively lower and higher (60 °C and 90 °C for 16 h) than the threshold. For all measurements, eight resins from different trees were harvested using an isolation technique developed by Biogemme®. After drying, samples were kept at room temperature, and the softening point temperature and the remaining turpentine amount were measured over time using Thermomechanical Analysis (TMA) and Thermogravimetric Analysis (TGA) respectively. After three months, the results show that a majority of samples dried at 90 °C have a softening temperature under 25 °C, while all the samples dried at 60 °C have a softening temperature above 60 °C. These results can be explained by a modification of the physical properties of the samples dried at 90 °C: they start to behave like gels, preventing the evaporation of their liquid phases. These new results highlight some properties of resin that may be interesting to develop a new strategy for reducing resin exudation on outdoor wood siding, by fixing the resin inside the wood during the industrial drying process.

International audience; The present work investigates the potentiality of poly(N-vinyl caprolactam) (PVCL)-based thermoresponsive microgels decorated with cationic polymer brushes as drug delivery carriers. The effect of physico-chemical features of the colloids on cell viability response have to be carefully investigated to establish the range of suitable hydrodynamic diameters, crosslinking densities, lengths and ratios of the cationic polyelectrolyte shell which allow their efficient and effective use for cargo loading, transport and delivery. The colloidal stability of all cationic thermoresponsive microgels is maintained over several days of incubation at 37 °C in biological mimicking medium (Dulbecco's Modified Eagle's Medium supplemented with fetal bovine serum). The thin cationic polymer shell covalently anchored does not hinder the all range of microgels to be biocompatible while the higher cytotoxicity of the doxorubicin-loaded microgels on HeLa cells proves their anti-tumor activity. The core-shell PVCL drug delivery nanocarriers allow a sustained release of doxorubicin with a slightly higher viability of HeLa cells incubated in the presence of DOXO-loaded microgels compared to the free DOXO. The nature of the endocytosis pathway is investigated through a quantification of the extent of the cellular survival rate in the presence of various cellular uptake inhibitors. A clathrin-dependent internalization was observed.

International audience; A method to improve wood durability using natural extracts was evaluated. Wood deterioration is a condition caused by several abiotic and biotic factors including fungal contamination. To date, approaches aiming at the reduction of these contaminants mainly involve the use of chemicals agents. Natural products could represent an alternative strategy. Aqueous extracts of Punica granatum L. (pomegranate) peel and Melia azedarach L. barks were evaluated as antifungal agents to improve natural durability of beech wood and maritime pine. To evaluate the effect of treatments under simulated accelerated ageing of wood by natural conditions, impregnation and leaching tests were performed. Results demonstrated that samples impregnated with pomegranate or M. azedarach solutions notably increased the biological resistance of wood in a dose-dependent manner. These results were confirmed by the reduction in weight losses in treated samples even after 6 weeks of fungal exposure. Moreover, after leaching tests, 20 and 7% (w/v) of pomegranate and M. azedarach extract solutions were demonstrated as the better concentrations to enhance wood durability. Total phenol content and characterization of the phenolic compounds in both, natural extracts and wood samples were analyzed by Folin–Ciocalteu assay and HPLC-DAD. In conclusion, it was demonstrated that the present method can be considered as an effective treatment to increase wood durability while it proposes the valorization of natural extractives in wood industry.

International audience; This work aims at designing functional biomaterials through selective chemical modification of xylan from beechwood. Acidic hydrolysis of xylan leaded to well-defined oligomers with an average of six xylose units per chain and with an aldehyde group at the reductive end. Reductive amination was performed on this aldehyde end-group to introduce an azide reactive group. 'Click chemistry' was then applied to couple these hydrophilic xylans moieties with different hydrophobic fatty acid methyl esters that were previously functionalized with complementary alkyne functions. The resulting amphiphilic bio-based conjugates were then self-assembled using three different methods, namely direct solubilization, thin-film rehydration/extrusion and microfluidics. Well -defined micelles and vesicles were obtained and their high loading capacity with propiconazole as an antifungal active molecule was shown. The resulting vesicles loaded with propiconazole in a microfluidic process, proved to significantly improve the antifungal activity of propiconazole, demonstrating the high potential of such xylan-based amphiphiles.

International audience; Self-organized honeycomb (HC) polymer films were fabricated as a bottom-up assembly and deposited onto glass substrates in order to create extraction layers for blue OLEDs. Relying on the fast and tunable " Breath Figure " process, HC films were prepared on a minute timescale and incorporated onto OLED devices, either through direct bottom-up formation onto the OLED substrates or through an original and convenient peeling/transfer method. Two types of HC films differing in period and morphology were prepared, and eventually led to an EQE improvement of 25% measured on an OLED whose emitter molecules are oriented parallel to the plane, using a vapor deposition at room temperature. Additionally, we have modeled the optical characteristics of the HC films, leaning on the fact they are periodic and very regular. This 3D optical model, complemented by a 1D electrical model to determine the Emission Zone Profile (EZP), predicts that the photonic films we fabricated are able to enhance up to 29% the EQE, and opens perspectives for a better design of extraction layers.

Amphiphilic copolymers based on renewable resources were involved as emulsifiers to prepare transparent terpene-in-water nanoemulsions. The amphiphilic copolymers are composed of hydrophobically modified poly(acrylic acid) (HMPAA) grafted with different fractions of hydrophobic bio-based tetrahydrogeraniol (THG) side chains. The well-defined PAA were synthesized by reversible addition fragmentation transfer (RAFT) polymerization in order to tune the number-average molar mass of the initial PAA. The self-assembly in aqueous solution of the HMPAA copolymers was investigated through the measurement of their critical aggregation concentration by viscometry, tensiometry, dynamic light scattering and the determination of their aggregation number by static light scattering. Series of oil-in-water nanoemulsions using dihydromyrcenol (DHM) terpene as dispersed phase and PAA-THG as emulsifier were prepared with different PAA-THG/DHM weight ratios and DHM/water weight ratios. The level of transparency of the emulsions was monitored though the transmittance value measured at 600 nm and the measurements of the hydrodynamic diameter of droplets by dynamic light scattering. This study highlights that the structure of the PAAx-THGy is a key parameter to prepare terpene-in-water nanoemulsions with the required high level of transparency. The optimised structure of the emulsifier consists in a moderate degree of polymerization of PAA backbone ( DP ‾ n ,PAA ≤ 180 ) along with an intermediate average degree of substitution in hydrophobic THG side chains (13 ≤ DS ‾ ≤ 32).

International audience; A novel methodol. to overcome the predominance of π-π interactions on the organization of rod-coil copolymer is reported. We demonstrated changes in the self-assembly morphol. of poly(3-hexylthiophene)-b-poly(Me methacrylate) (P3HT-b-PMMA) block copolymer BCP, by introducing an ionic group to the linking unit between the two blocks. A neutral polymer precursor was synthesized from ethynyl-terminated P3HT and azido-terminated PMMA via Huisgen's 1,3-dipolar cycloaddn. And then two 1,2,3-triazolium-based block copolymers with different counteranions were obtained by a quaternization of 1,2,3-triazole groups with Me iodide, and subsequent anion exchange with a fluorinated salt, bis(trifluoromethane) sulfonimide salt. Atomic force microscopy, modulated differential scanning calorimetry and x-ray scattering were used to prove that the crystn. of the conjugated block is disrupted by the addnl. ionic interactions imposed to the system. The 1,2,3-triazolium-based BCP with iodide as the counterion exhibited highly organized well-defined fibrils, as the diblock phase segregation χ becomes predominant over the rod-rod interaction μ. When the more stable and larger NTf2- was used as counterion, P3HT phase was disrupted and no crystn. was obsd. This methodol. could be a useful strategy to open the range of nanomorphologies reachable with a semiconducting polymer for electronic or photovoltaic applications.

Key message Variability of embolism resistance within individual trees was assessed in four Pinaceae species by using a single method of measurement: the Cavitron. Contrary to what has been previously observed, our findings show a small variability in embolism resistance within and between organs. Indeed, we found (i) a lack of variability between branches within the crown, and (ii) that roots and trunks are either equally resistant or slightly more vulnerable to embolism than branches. This contradicts the vulnerability segmentation hypothesis proposed in the early 1990s. This paper also demonstrates that only few branches are necessary to determine the embolism resistance of a given tree.[br/] Context Embolism formation in xylem has an important impact on plant growth and survival. Since most studies on xylem embolism resistance focus on branches, it remains questionable how the entire plant deals with embolism across organs.[br/] Aims In this study, we aimed to evaluate the variability of embolism resistance within a given organ and between different organs within a single tree.[br/] Methods Based on the Cavitron method, we estimated the intra-organ and the intra-plant variability of embolism resistance for four Pinaceae species. In addition, we compared pit anatomical characters for wood of all organs and species.[br/] Results We found no variability of embolism resistance for a given organ within a tree. At the tree level, trunks and roots were either equally or more vulnerable to embolism than branches. For all species, organs that showed a similar range of embolism resistance presented similar torus-aperture overlap values. However, the least negative P 50 value for roots of Pinus pinaster was associated with the lowest torus-aperture overlap value.[br/] Conclusion Our findings suggest that P 50 values are constrained within a particular organ and that intra-tree variation in embolism resistance is less substantial than previously reported. Moreover, our data do not support the vulnerability segmentation hypothesis which suggests that distal organs are more vulnerable to xylem embolism.

Oenococcus oeni is the bacterium most often associated with spontaneous malolactic fermentation (MLF) of wine. During MLF, malic acid is transformed into lactic acid and several metabolites are modified, modulating wine’s total acidity and improving its sensory properties. Previous works have suggested that certain genetic groups of O. oeni strains are associated to different kinds of products. In the present study we have spotted two groups of strains isolated mainly from Burgundy wines, one associated to red wines and the other to white wines. Sequencing 14 genomes of red and white wine strains revealed that they share a common ancestor that probably colonised two different substrates –red and white wine-associated environments–, diverging over time and disseminating to various regions. Their capacity to perform MLF and modify the volatile profile of wine was determined by fermenting a chardonnay wine and analysing its volatile fraction with a non-targeted metabolomics approach by GC-MS. The strains had a different impact on the volatile composition depending on their group of origin. These results show for the first time a correspondence between the product of origin of the strains and the volatile profile of the wines they produce. Furthermore, the genetic features that might be implied in these different phenotypes are examined.