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OsbHLH064, an IVb bHLH Transcription Factor, Regulates Iron Homeostasis and Enhances Grain Fe Accumulation in Rice
No full textInternational audienceIron (Fe) is an essential micronutrient for plant growth and development. The maintenance of Fe homeostasis relies on sophisticated regulatory networks where bHLH transcription factors play a key role. However, how these factors coordinate to regulate this vital process is not fully understood. Here, we characterise OsbHLH064, a previously unstudied IVb bHLH transcription factor, and reveal its critical role in iron homeostasis in rice. Loss of OsbHLH064 results in constitutive activation of Fe homeostasis-related genes under Fe-sufficient conditions, whereas its overexpression strongly suppresses their expression. Remarkably, OsbHLH064 overexpression leads to excessive Fe accumulation in roots, shoots and brown rice. Under Fe deficiency, it also triggers ROS overproduction, highlighting its essential role in balancing Fe homeostasis and oxidative stress. Mechanistically, OsbHLH064 forms heterodimers with IVc bHLH transcription factors, and these interactions facilitate its nuclear localisation. OsbHLH064 represses OsIRO2 and OsIRO3 by competing with or sequestering IVc activators at shared promoters, thereby limiting downstream transcriptional activation. Furthermore, OsbHLH064 directly binds not only canonical IVb/IVc targets but also a broader set of genes involved in Fe uptake, translocation and signalling. Collectively, these findings establish OsbHLH064 as a central upstream regulator integrating multiple pathways to maintain Fe homeostasis and suggest its potential as a target for biofortification strategies aimed at enhancing iron content in rice grains
Combiner instruments de politique et mesures locales pour promouvoir l'agrobiodiversité
No full textInternational audienceDie Agrobiodiversität ist generell rückläufig. In der Literatur wird zwar die Rolle der öffentlichen Politik in diesem Prozess hervorgehoben, jedoch besteht nach wie vor eine Forschungslücke hinsichtlich der Frage, wie politische Maßnahmen dazu beitragen können, diesen Trend umzukehren. Ein Ansatz besteht darin, landwirtschaftlichen Betrieben, die Wert auf Pflanzen‐ und Sortenvielfalt legen, wirtschaftliche Unterstützung zu gewähren. Dieser Artikel gibt auf der Grundlage einer Literaturrecherche und von Experteninterviews zunächst einen Überblick über europäische und nationale politische Instrumente, die zur wirtschaftlichen Förderung der Agrobiodiversität in landwirtschaftlichen Betrieben eingesetzt werden können. Der Schwerpunkt liegt dabei auf sieben europäischen Ländern. Anschließend wird auf der Basis von Fallstudien eine Typologie lokaler Initiativen vorgestellt, die diese Instrumente mit Maßnahmen kombinieren. So können landwirtschaftliche Betriebe, die Nebenkulturen und traditionelle Sorten anbauen, wirtschaftlich gefördert werden. Diese Förderung ist in erster Linie indirekter Natur und reicht von der Bereitstellung von Saatgut bis zur Marktentwicklung, wobei die meisten Initiativen nicht die gesamte Wertschöpfungskette abdecken. Die Ergebnisse unterstreichen die entscheidende Rolle der lokalen Behörden und bestätigen den Wert öffentlich‐privater Partnerschaften bei der Förderung der Pflanzen‐ und Sortenvielfalt. Sie betonen auch die Notwendigkeit einer stärkeren Koordinierung zwischen politischen Maßnahmen und Governance‐Ebenen, um die Wertschöpfungsketten zu stärken, die Agrobiodiversität unterstützen. Zudem werden weitere Untersuchungen gefordert, um zu bewerten, welchen Beitrag die kombinierte Unterstützung durch politische Instrumente und lokale Maßnahmen zu neuen Geschäftsmodellen auf Ebene der landwirtschaftlichen Betriebe leistet.Agrobiodiversity is in decline. While the literature highlights the role of public policy in this process, a research gap remains concerning how policies can help reverse this trend by providing economic support to farms that value crop and varietal diversity. Based on desk research and expert interviews, this article first provides an overview of European and national policy instruments that can be used to economically support the promotion of agrobiodiversity on farms, focusing on seven European countries. Drawing on case study findings, it then presents a typology of local initiatives that combine these instruments with local measures to provide economic support to farms cultivating minor crops and traditional varieties. This support is primarily indirect, ranging from seed provision to market development, although most initiatives do not cover the entire value chain. The results underline the critical role of local authorities and confirm the value of public‐private partnerships in promoting crop and varietal diversity. They also emphasise the need for stronger coordination between policy measures and governance levels to support value chains that foster agrobiodiversity, and call for further research to assess how the combined support of policy instruments and local measures contributes to new business models at farm level.L’agrobiodiversité est en déclin . Si la littérature souligne le rôle des politiques publiques dans ce processus, des lacunes subsistent quant à la manière dont ces politiques peuvent contribuer à inverser cette tendance en apportant une aide économique aux exploitations agricoles qui valorisent la diversité des espèces et des variétés végétales. S’appuyant sur une recherche documentaire et des entretiens avec des experts, cet article présente d’abord un aperçu des instruments de politique européens et nationaux qui peuvent soutenir économiquement l’utilisation de l’agrobiodiversité dans les exploitations agricoles, en se concentrant sur sept pays européens. Avec l’appui d’études de cas, il propose ensuite une typologie d’initiatives locales combinant ces instruments à des mesures locales pour apporter une aide économique aux exploitations cultivant des cultures mineures et des variétés traditionnelles. Ces aides sont principalement indirectes, allant de la fourniture de semences au développement des marchés, mais la plupart des initiatives ne couvrent pas l’intégralité de la chaîne de valeur. Les résultats soulignent le rôle crucial des collectivités territoriales et confirment l’intérêt des partenariats public‐privé pour la promotion de la diversité des cultures et des variétés. Ils mettent également en évidence la nécessité d’une coordination renforcée entre les mesures gouvernementales et les différents niveaux de gouvernance afin de soutenir les chaînes de valeur favorisant l’agrobiodiversité. Enfin, ces résultats appellent à des recherches complémentaires pour évaluer comment le soutien combiné des instruments de politique et des mesures locales contribue à l’émergence de nouveaux modèles économiques au niveau des exploitations
Le renouveau du sauvage : faire, refaire, laisser-faire le sauvage dans nos territoires
No full textInternational audienceCet article propose une restitution du colloque « Le renouveau du sauvage » tenu au château de Cerisy du 26 juin au 2 juillet 2023, axé sur la cohabitation avec le sauvage et ses impacts sur la société. Le colloque a favorisé les échanges entre disciplines variées et acteurs de terrain (écologistes, géographes, historiens, philosophes, sociologues, naturalistes, gestionnaires d’espaces protégés, etc.). En parallèle, des interactions ont eu lieu avec le colloque « Que peut la littérature pour les vivants ? ». Cet article montre l’intérêt du dialogue entre sciences écologiques et humanités environnementales, révélant la diversité de la remise en question de l’anthropocentrisme. Il souligne également le rôle de la littérature et des arts dans la réesthétisation du monde malgré l’épuisement des récits. Le réensauvagement se décline sous diverses formes interrogées par la transition écologiqu
Predictions of wheat phenotypic variability by integrating high-throughput phenotyping observations into a crop growth model
No full textInternational audienceAccurate prediction of phenotypes across genotypes and environments is crucial for accelerating crop improvement. Process-based crop growth models (CGMs) can capture complex genotype-by-environment interactions, but their use is limited by labor-intensive genotypic parameter measurements. Here, we developed a faster data assimilation pipeline integrating high-throughput phenotyping (HTP) observations with the Sir-iusQuality wheat model to efficiently estimate key genotypic parameters and predict genotype performance. Using time-series RGB imagery from a ground-based Phenomobile, we assimilated intercepted photosynthetically active radiation (fIPAR), heading date, and final grain yield to jointly assimilated to calibrate twelve genotypic parameters governing phenology, canopy development, light interception, biomass accumulation, and grain filling. Two data assimilation strategies-a Bayesian DREAM (zs) algorithm and a lookup table (LUT) inversion-were compared through both in silico experiment and eight years of multi-environment field trials of nine durum wheat cultivars. The LUT method demonstrated superior computational efficiency, with prediction accuracy comparable to Bayesian inference on real field data. Multi-year field trials showed that two environments (year/site) were sufficient to reliably characterize genotypic parameters and predict performance across environments. By combining time-series HTP data with ecophysiological modeling, our data assimilation pipeline offers breeders a powerful tool for genotype characterization. It streamlines the process of capturing environmental variance and phenotypic stability, reducing time and effort in crop improvement
Optimal control synthesis for a class of production-regeneration systems -Application to membrane filtration
No full textInternational audienceThis paper studies an optimal control framework for a class of production-regeneration systems, which have to alternate between productive and regenerative phases, such as membrane filtration. These systems are modeled as control-affine systems of triangular forms with a one-dimentional internal state. Pontryagin's Maximum Principle and Green's theorem provide conditions on optimal trajectories, distinguishing bang and singular arcs, where singular arcs are distinguished between turnpike or anti-turnpike. Structural results show that optimal solutions admit at most two switching times and the exhaustive list of admissible structures is provided. The paper further introduces a constructive method to provide optimal feedback synthesis by determining switching and dispersal loci through differential continuation. Numerical applications to membrane filtration processes illustrate the approach for energy minimization and volume maximization cases. An example with non-connected singular locus illustrates the method's generality
Phylogeny, systematics and evolution of mimicry patterns in Neotropical limenitidine butterflies
No full textDATA AVAILABILITY STATEMENT: The data that support the findings of this study are openly available in the Dryad repository at https://doi.org/10.5061/dryad.7h44j104b (Pàez et al, 2025). Newly generated sequences were deposited in GenBank at https://www.ncbi.nlm.nih.gov and are registered with the following accession numbers: PX243222–PX243274, PX244453–PX244551 (COI); PX114826–PX114854 (EF1a); PX172283–PX172334 (GAPDH); PX172335, PX254824–PX254850 (IDH); PX254786–PX254823 (RpS5); PX207538–PX207552 (ArgKin); PX172259–PX172282 (CAD); PX207522–PX207537 (CycY); PX172235–PX172258 (DDC); PX270910–PX270945 (Exp1); PX172202–PX172234 (Nex9); PX114965–PX115012 (PolII); PX114932–PX114964 (ProSup); PX114890–PX114931 (PSb); PX114855–PX114889 (RpS2); PX207556–PX207592 (UDPG6DH) (see Table S1 for details).International audienceThe Neotropical butterfly genus Adelpha Hübner exhibits remarkable species diversity and striking convergence in wing colour patterns potentially explained by mimicry, making it an exceptional model for exploring trait evolution and its relationship with speciation. To date, unresolved phylogenetic relationships hinder a comprehensive understanding of the evolutionary biology of the genus. Using a novel multi‐marker dataset combining one mitochondrial and 15 nuclear gene fragments, we generate the most comprehensive phylogeny of the genus Adelpha to revisit its systematics and investigate the evolution of mimicry colour patterns. Our dataset encompasses 83 of the 87 known extant species and six Limenitis species that were recently excluded from Adelpha (134 of c . 160 subspecies in total), collectively displaying 14 distinct mimicry patterns. We provide conclusive evidence that corroborates previous work on the polyphyly of Adelpha as historically conceived and describe the genus Adelphina Páez & Willmott n. gen . to stabilise the nomenclature. The comprehensive phylogeny provided in this study lays a solid foundation for future research into the processes driving diversification within these species interacting through mimicry. Ancestral character state reconstruction reveals the gradual evolution of mimicry patterns. The more common mimicry pattern IPHICLUS (forewing with orange subapical spot and white band) is inferred as ancestral, but repeated convergent evolution is also recovered. Evolutionary convergence is also observed for the second most abundant mimicry pattern, COCALA (orange‐white banded). Increased rates of mimicry pattern evolution are also found towards the equator. These results underscore the complexity of mimicry evolution in the Neotropical limenitidines, i.e., Adelpha and Adelphina n. gen. , emphasising the need to explore its interplay with other biotic and abiotic factors
Crowdsourced biodiversity monitoring fills gaps in global plant trait mapping
No full textInternational audiencePlant functional traits are fundamental to ecosystem dynamics and Earth system processes, but their global characterization is limited by available field surveys and trait measurements. Recent expansions in biodiversity data aggregation—including vegetation surveys, citizen science observations, and trait measurements—offer new opportunities to overcome these constraints. Here we demonstrate that combining these diverse data sources with high-resolution Earth observation data enables accurate modeling of key plant traits at up to 1 km 2 resolution. Our approach achieves correlations up to 0.63 (15 of 31 traits exceeding 0.50) and improved spatial transferability, effectively bridging gaps in under-sampled regions. By capturing a broad range of traits with high spatial coverage, these maps can enhance understanding of plant community properties and ecosystem functioning, while serving as tools for modeling global biogeochemical processes and informing conservation efforts. Our framework highlights the power of crowdsourced biodiversity data in addressing longstanding extrapolation challenges in global plant trait modeling, with continued advancements in data collection and remote sensing poised to further refine trait-based understanding of the biosphere
Sweat sodium composition and sweat loss estimation through wearable sensors and predictive equations in dry and humid hot conditions
No full textInternational audienceIntroduction: Individualized sweat testing is essential for tailoring hydration and nutrition strategies, as water and sodium losses during exercise vary greatly across athletes. The validity of a wearable sweat sensor (S1, Flowbio) and a handheld analyzer (LAQUAtwin, Horiba Advanced Techno) for measuring sweat sodium concentration ([Na + ]) was tested against flame photometry (FP). Additionally, whole body sweat loss (WBSL) estimated by the S1 and by a sweat rate calculator (SRC) was compared to the scale-based method. Methods: Twenty-three recreationally active participants (11 males, 12 females) completed two sessions in hot and dry (40 °C, 36% rh) and hot and humid (30 °C, 81% rh) controlled environmental conditions on a cycling ergometer (74 ± 12 min, 1.9 ± 0.4 W/kg). Participants were instrumented with two S1 sensors and absorbent patches placed on each upper arm. Sweat was extracted from patches to measure [Na + ] with LAQUAtwin and FP. Nude body mass was measured to the nearest 0.005 kg before and after exercise, with fluid intake monitored to determine WBSL. The influence of the method and the condition on the measure of sweat [Na + ] and WBSL was investigated with linear mixed-effects models. Results: The estimated marginal means of sweat [Na + ] in dry conditions for S1 and LAQUAtwin were equivalent (both 53 mmol/L, p = 0.952) and significantly lower than FP (63 mmol, both -10 mmol, p < 0.001). No significant interaction effects were observed between methods and conditions. For WBSL, the S1 estimation (1.479 kg) was not different than the scale measure (1.432 kg, 0.047, p = 0.624) while the SRC estimation (1.202 kg) was significantly lower than the scale and S1 (both p < 0.001), without interactions effects. Conclusion: S1 offers equivalent and more practical collection of sweat [Na + ] compared to the LAQUAtwin during indoor cycling ergometer exercise. However, measurements from both devices should currently be interpreted Frontiers in Physiology 01 frontiersin.org Bandiera et al. 10.3389/fphys.2025.1717275with caution and not considered equivalent to laboratory-grade analyses. Furthermore, S1 is an adequate tool during indoor cycling ergometer exercise to estimate WBSL when scale measurements are impractical, while SRC was found to underestimate fluid loss.</p
Potential of local collective action to reduce pesticide use in a French Mediterranean landscape
No full textInternational audiencePesticide use in agriculture has significant negative impacts on human health, ecosystems, and natural resources. The failure to meet targets for pesticide reduction at the farm level underscores the need for a systemic, holistic approach that considers the diversity of actors and the complexity of the farming systems involved. The landscape level provides a relevant framework for addressing the reduction of pesticide use and impacts. In this study, we analyzed 19 initiatives aimed to reduce pesticide use or its impacts in agriculture in a Mediterranean peri-urban plain in southern France. Drawing on insights from landscape agronomy and research on collective action, we developed a novel conceptual framework to capture and analyze the diversity and complementarity of local dynamics of pesticide reduction. Through interviews, workshops, and farm surveys,we examined the factors driving the emergence of these initiatives and assessed their anticipated impacts on farming practices, landscape patterns, and natural resources at the landscape level. The results revealed that these initiatives were led by diverse, and sometimes conflicting, strategies to reduce pesticide use that focused mainly on optimizing pesticide use in dominant agricultural systems, alongside farm reconfiguration and biodiversity integration strategies. This study advances current knowledge by providing actionable insights to improve collective action at the landscape level, such as spaces for synergies for landscape-level coordination and identified barriers to this coordination. Our findings emphasize the importance of embracing complexity when designing and implementing pesticide-reduction strategies
Thiamine and folate immunolocalization in germinating lentil seeds: A microstructural investigation
No full textInternational audienceHighlights: • Thiamine and folate act as cofactors in many human and vegetal metabolic pathways. • Germination is an effective process for increasing the thiamine and folate content. • Immunohistochemistry can localize the storage area of thiamine and folate. • Image analysis revealed heterogeneous distribution of vitamers in the pulse. • We obtained both quantitative and qualitative information on the metabolite content.Abstract: Thiamine and folate are vital for both human and plant health, serving as cofactors in various metabolic processes. Thiamine is essential for carbohydrate and amino acid metabolism, while folate is crucial for DNA synthesis and the methyl cycle. Germination has been proven to increase thiamine and folate levels in lentils. While high-performance liquid chromatography (HPLC) is effective for measuring vitamin content, it does not reveal the spatial distribution of these compounds within seeds during germination. To address this, immunohistochemistry (IHC) was used in this study to localize and quantify thiamine and folate in dry, soaked, and germinated lentils. The analysis revealed that these vitamins are distributed unevenly across cotyledons and cells. In dry seeds, thiamine and folate were concentrated around starch granules, but in soaked and germinated seeds, they were dispersed throughout the cytoplasm and near protein bodies. This innovative method provided both quantitative and qualitative insights into how germination affects vitamin distribution, enhancing our understanding of seed metabolism and the behavior of vitamins during food processing