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Sesquiterpene diversity and TPS-a gene characterization in the pelargonium genus
No full textInternational audienceSesquiterpenes are key molecules nurturing the complex and subtle base notes of pelargonium fragrances. Yet, their contribution to the essential oil olfactory profile and their biosynthesis are far from being well understood. We therefore explored sesquiterpene composition in 10 pelargonium accessions and revealed that, although lowly accumulated, their wide diversity participates to the biochemical uniqueness of each fragrance. We further investigated sesquiterpene biosynthesis thanks to a multiomic approach, integrating transcriptomic together with metabolomic data. A phylogenetic analysis of pelargonium TPS-a subfamily first revealed a total of 21 groups of orthology and denoted a strong transcriptional regulation of related enzymes. Seven sesquiterpene synthases were then wisely selected for functional characterization, both in vitro and in planta. Among them, two 6,9-guaidiene synthases were characterized for the first time in plants. Finally, we explored the role of amino acids located in the active site of sesquiterpene synthases in the enzymatic mechanism using site-directed mutagenesis. Altogether, this work highlights the great potential of the multiomic approach to predict TPS functions, but also exposes its limitations, inherent to terpene synthase's plasticity.</div
A modified Rittinger model for the grinding of wet granular material
No full textInternational audienceGrinding is a fundamental process widely used across various industrial sectors. Although often considered merely a pre-treatment step, it remains poorly studied from a fundamental perspective-especially when accounting for the presence of water or humidity. In particular, the relationship between grinding parameters and size reduction efficiency remains a critical bottleneck in optimizing this highly energy-intensive operation. The water content of the raw material to be ground is often a poorly controlled factor, yet it strongly influences grinding efficiency. This can be due to lubrication forces and capillary cohesion, which leads to the formation of aggregates that are more difficult to grind. This paper presents an original approach to link the particle aggregation capacity with the grinding rate. This aggregation, which limits the energy available for effective grinding, was estimated using the Carr index. A modified Rittinger law that relates the specific surface area created to the energy transmitted by the grinding media, incorporating the influence of water content is proposed. This model provides new guidelines for achieving more efficient comminution
EcoBioCap querying : A Decision Support System to design modified atmosphere packaging for fresh produce based on a bipolar flexible querying approach
No full textA safari across France: soil fauna insights from a nationwide soil quality monitoring program
No full textInternational audienceSoil biodiversity is fundamental to ecosystem functioning but remains underrepresented in conservation policies and large-scale monitoring. Here, we present RMQS-Biodiversity, a nationwide soil biodiversity survey integrated into the French Soil Quality Monitoring Network (RMQS), and illustrate its potential for soil ecology research. In this pioneer study, we examine three major ecological aspects: (i) how systematic grid-based sampling captures micro-food web patterns using nematode communities, (ii) the spatial turnover of detritivore communities (Collembola, Isopoda, Diplopoda) in response to environmental and geographic gradients, and (iii) the influence of macroecological drivers on predator (Carabidae) morphological traits. Across 69 sites, we identified a few widespread species coexisting with numerous rare taxa, underscoring the value of large-scale surveys for detecting cryptic biodiversity. Nematode indicators revealed high variability in food web structure across land uses, with increased facultative phytophagous nematodes in forests. Isopods and diplopods were strongly structured by dispersal constraints, while springtails exhibited weaker environmental responses, likely due to their higher dispersal capacity. Additionally, sexual size dimorphism in Carabidae varied by habitat, with female-biased dimorphism in closed habitats but no dimorphism in open environments, highlighting habitat stability's role in shaping morphological traits. This study demonstrates the value of multi-taxon, multi-trophic biodiversity assessments in long-term soil monitoring. RMQS-Biodiversity provides a robust framework for soil biodiversity monitoring and conservation, refining bioindicators of soil quality and informing policies such as the EU Soil Monitoring Law
No impact of black-eye symptom on foraging behaviour and reproductive success of Northern gannets following highly pathogenic avian influenza
No full textInternational audienceHighly Pathogenic Avian Influenza Virus (HPAIV) is currently causing major wild animal population crashes all over the world including Antarctica. Yet, there are important knowledge gaps on the implications of long-lasting symptoms for the ecology of surviving individuals and the conservation of their populations. Using GPS tracking devices and long-term demographic data, we examined the effects of HPAIV on a seabird population of Northern gannets (Morus bassanus) in the colony of Rouzic, France. One year after the HPAIV outbreak of 2022, the breeding gannet population declined by 38 % and 22.3 % of surviving breeders were zombie birds: they had darkened irises, a black-eye symptom indicative of past infection to HPAIV. Importantly, we demonstrate that black eyes were not associated with detectable differences in the foraging behaviour and habitat use of surviving breeding gannets. Compared to years prior to the outbreak, the foraging effort of breeding individuals was lower and breeding success was higher, aligning with Ashmole's halo hypothesis, which posits that smaller seabird populations face lower intra-specific competition for food in the vicinity of their breeding colony and thereby, have a reduced foraging range. Our results highlight the importance of density-dependant mechanisms in population responses to sudden mass-mortalities, but raise conservation concerns, especially for species facing cumulative threats. In the long-term, locally depleted populations may reach critical thresholds where individual abundance and productivity may not be sufficient to maintain a positive demographic growth rate, ultimately leading to local population extinctions
Denoising over networks with applications to partially observed epidemics
No full textInternational audienceA novel method is introduced for denoising partially observed signals over networks using graph total variation (TV) regularization, a technique adapted from signal processing to handle binary data. This approach extends existing results derived for Gaussian data to the discrete, binary case — a method hereafter referred to as “one-bit TV denoising.” The framework considers a network represented as a set of nodes with binary observations, where edges encode pairwise relationships between nodes. A key theoretical contribution is the establishment of consistency guarantees of graph TV denoising for the recovery of underlying node-level probabilities. The method is well suited for settings with missing data, enabling robust inference from incompleteobservations. Extensive numerical experiments and real-world applications further highlight its effectiveness, underscoring its potential in various practical scenarios that require denoising and prediction on networks with binary-valued data. Finally, applications to two real-world epidemicscenarios demonstrate that one-bit total variation denoising significantly enhances the accuracy of network-based nowcasting and forecasting
A historical Approach of Vulnerability: An Interview with Gregory Bankoff
No full textInternational audienceGreg Bankoff is a historical geographer whose work examines how societies and their environments shape one another over time, with particular attention to how communities adapt to recurrent hazards. For more than three decades, his research has focused on Southeast Asia, Central Asia, the Pacific, and the North Sea, exploring how societies — past and present — have learned to normalise risk and respond to crisis. His approach is distinctly interdisciplinary, combining archival research with fieldwork, community mapping, interviews, and focus groups to illuminate the lived experience of vulnerability and resilience. He is Research Fellow at Ateneo de Manila University and Professor Emeritus of Environmental History at the University of Hull. Bankoff has published widely, with more than 120 refereed journal articles and book chapters. His recent works include the co-edited volume Why Vulnerability Still Matters: The Politics of Disaster Risk Creation (2022)
For a contribution to studies on disaster vulnerability: a techno-political approach
No full textInternational audienceFive decades of extensive research on disaster vulnerability have consolidated this concept as a cornerstone of analysis and knowledge production in the social sciences and humanities. Seeking to engage the Francophone sphere with a range of international debates concerning the relevance and limitations of this notion, this special issue revisits its trajectory through a focus on the technopolitics of vulnerability in the Global South. We examine a body of scholarship that approaches vulnerability as both a scientific and a political project within critical social sciences and humanities research on disasters in the Global South, with particular attention to how “the political” is conceptualised in this work. We then outline four lines of inquiry emerging from the contributions to this issue, structured around a technopolitical perspective. In doing so, we argue that an approach centred on the technopolitics of vulnerability provides a productive framework for renewing research on risk and disasters
Editorial for research topic: Advancing mycorrhizal research for sustainable ecosystem and agricultural practices
No full textInternational audienceMycorrhizal symbiosis, a mutualistic association between plant roots and soil fungi, plays a crucial role in enhancing plant nutrition, stress tolerance, and overall adaptation to environmental conditions (van der Heijden et al., 2015). Despite the long-standing recognition of these benefits, research has primarily focused on understanding the mechanisms underlying the establishment and functioning of these interactions. Recent studies have highlighted the significant role of fungal hyphal networks in soil carbon storage, further emphasizing the ecological importance of mycorrhizal symbioses. However, there remain substantial gaps in our understanding of how these interactions can be optimized for both natural ecosystems and agricultural applications, especially under the increasing pressure of global climate change.The present Research Topic (RT) was initiated in the context of the 7 th French Mycorrhizal Days in Montpellier in May 2024, an international meeting bringing regularly together mycorrhizal research, students and companies from francophone countries (https://jmf7.journees.inrae.fr/). The RT aims to consolidate current research on mycorrhizal symbioses across various levels, from molecular and functional analyses to ecosystem studies and practical applications. The primary objective is to enhance our fundamental knowledge and to facilitate its translation into ecological and sustainable practices for plant growth, soil management, and ecosystem balance. The call for papers attracted several contributions, Mycorrhizal symbiosis is tightly regulated by host plants and fungi and requires major root cell and fungal hyphae reprogramming to form structures enabling nutrient exchange (Choi et al., 2018;Ho-Plágaro and García-Garrido, 2022). Specific molecular players and mechanisms involved in the establishment of arbuscular mycorrhizal (AM) symbioses were investigated in two studies. Strigolactones, phytohormones with dual signalling functions within plant roots and in rhizosphere interactions (Al-Babili and Bouwmeester, 2015), have been demonstrated to impact spore germination and hyphal branching affecting in turn root colonization by AM fungi (Akiyama et al., 2010). Here, Klein et al. analyzed strain-specific impacts of strigolactones using two Rhizophagus irregularis strains and their response regarding germination and pre-symbiotic growth. Observed strain-specific differences may Impact of AM fungi on plant performance was analyzed by Alayafi et al. for two crop plants, sunflower (Helianthus annuus) and pumpkin (Cucurbita pepo), under field conditions for two years. Inoculation with the AM fungus Funneliformis mosseae improved plant nutrient uptake, biomass and specifically oil yield and quality, dependent on possible synergistic effects of intercropping (Reddy et al., 2023). Such field studies, going beyond laboratory work under controlled and limited conditions, underline the importance of beneficial interactions for modern agriculture. In turn, Battie-Laclau et al. reported also that the vineyard's "terroir", understood as a cultivated ecosystem where grapevine interacts with their natural environment, is critical for the composition of the microbiota community. On the other hand, agricultural practices promoting AM fungi in grapevine cultures have been long time neglected as massive fungicide treatments were needed to protect vineyards. Only since recently, with the increasing demand for more natural culture conditions, research is focalizing on promoting AM fungi in vineyards through the use of more organic management practices. Such changes promoting agroecology (Jindo et al., 2022) will induce higher diversity of AM communities and thus determine the future sustainable development of vineyards over next decades. This study showed the dominant effect of geographical effects, AM communities mainly be structured by terroir even before practice, underscoring the necessity for future studies on fungal inoculation in vineyards to consider the specific characteristics of each terroir.Another important topic is the impact and use of beneficial interactions for a better adaptation of plants to challenging environmental conditions and climate change. Mycorrhizal symbioses, among other beneficial associations, are playing a decisive role in improving plant tolerance to abiotic and biotic stress (Usman et al., 2021). Regarding other beneficial interactions, Hassan et al. focalized on plant growth-promoting bacteria (PGPB, Micromonospora sp) and demonstrated their role in mitigating effects on heat stress in wheat by metabolic adaptations enhancing photosynthetic efficiency and antioxidant defence. The importance of AM symbiosis for the bioavailability of essential micronutrients in wheat has been recently highlighted (Nguyen et al., 2025). In a more general context, Lethielleux-Juge reviewed the impact of mycorrhizal symbioses and associated soil microbiomes in ecological restoration. The use of AM fungi, both natives or exotic, have been widely reported in ecosystem restoration (De Moura et al., 2022). AM fungi grow at diverse soil conditions, colonizing most plant species (from herbs to trees), and can evolve together with plants after revegetation. Moreover, the interaction of AM fungi with different ectomycorrhizal fungi, PGPB, rhizobacteria and mycorrhiza-helper bacteria will allow to improve soil attributes and plant adaptation to stress in a complex network of plant-soil-microbiomes with high relevance in ecosystem dynamics.In summary, studies included in this RT are dealing with a broad panel of questions regarding our insight in and application of beneficial mycorrhizal interactions. Further questions concern still better understanding of mycorrhizal networks in natural ecosystems, in soil carbon storage, and under diverse challenging abiotic and biotic environmental conditions.For scientifically based agricultural applications, best practices for managing plant-soil biota on the field-scale will have to include whole microbiome interactions
