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Welcome Pathogens: Transient Heat Dampens Immune Responses to Acibenzolar‐ <i>S</i> ‐Methyl in Apple Plants
No full textInternational audienceClimate change affects plant-pathogen interactions, with disease outcome varying depending on the pathosystem and environmental scenario. In Arabidopsis, a thermo-sensitive module of salicylic acid (SA) signalling makes immunity vulnerable to heat. The potent resistance inducer acibenzolar-S-methyl (ASM), an SA analogue that up-regulates transcription of defence genes, could restore plant protection under heat but not core SA signalling. Here, we investigated how high temperature rewires the ASM-induced responses of the apple immune system. We treated apple plants with ASM under contrasting heatwave scenarios and subsequently exposed them to Erwinia amylovora (the fire blight bacterium) or Venturia inaequalis (the apple scab fungus) while monitoring gene expression. While pre-exposing apple plants to high temperature did not change their susceptibility to pathogens, it drove a loss of ASM-induced protection. Transcriptomic analysis revealed broad dampening of ASM-regulation upon high temperature, for a wide range of biological processes beyond defence. We uncovered thermosensitive 'resistance' and 'susceptibility' marker genes with ASM-responsiveness being critically vulnerable to heat. We concluded that exposure to heatwaves prevents ASM from fully mounting its protective responses in apple, not only lowering defences but also offering more favourable hosting conditions. Our work highlights plant immunity as the joint outcome of resistant and susceptible responses. | IntroductionClimate change modifies the many interactions between plants and pathogens. The 'disease triangle' framework posits that successful disease establishment requires a virulent pathogen, a susceptible host plant and favourable environmental conditions (Stevens 1960; Velásquez et al. 2018; Roussin-Léveillée et al. 2024). Changes in temperature, radiation, relative humidity (RH), soil water content and atmospheric CO 2 concentration may all affect the physiology and development of plants and pathogens, either directly or through their mutual interaction. For instance, temperature elevation has profound effects on plants, triggering</div
Integrated analysis of genome, metabolome, and transcriptome reveals a bHLH transcription factor potentially regulating the accumulation of flavonoids involved in carrot resistance to Alternaria leaf blight
No full textInternational audienceResistance of carrot to Alternaria leaf blight (ALB) caused by Alternaria dauci is a complex and quantitative trait. Numerous QTL for resistance (rQTLs) to ALB have been identified but the underlying mechanisms remain largely unknown. Some rQTLs have been recently proposed to be linked to the flavonoid content of carrot leaves. In this study, we performed a metabolic QTL analysis and shed light on the potential mechanisms underlying the most significant rQTL, located on carrot chromosome 6 and accounting for a large proportion of the resistance variation. The flavonoids apigenin 7- O -rutinoside, chrysoeriol 7- O -rutinoside and luteolin 7- O -rutinoside were identified as strongly correlated with resistance. The combination of genetic, metabolomic and transcriptomic approaches led to the identification of a gene encoding a bHLH162-like transcription factor, which may be responsible for the accumulation of these rutinosylated flavonoids. Transgenic expression of this bHLH transcription factor led to an over-accumulation of flavonoids in carrot calli, together with significant increase in the antifungal properties of the corresponding calli extracts. Altogether, the bHLH162-like transcription factor identified in this work is a strong candidate for explaining the flavonoid-based resistance to ALB in carrot
Urban earthworm communities driven more by climate and elevation than urbanisation intensity
No full textInternational audienceSoil biodiversity, particularly earthworms, plays a crucial role in ecosystem functions and services but remains largely understudied in urban environments. In this context, we conducted a synthesis analysis of 41 studies from urban environments (726 records, 1995–2024) to (1) describe patterns of earthworm communities, (2) identify the main drivers shaping urban earthworm communities, focusing on the effects of climate, degree of urbanization, soil properties, and local land use, with the expectation that climate would be the strongest driver, and (3) assess the occurrence of exotic earthworm species. Urban earthworm communities showed considerable variation in their abundance, biomass and species richness. Within our dataset, exotic species were detected in North America, South America, and Asia, but no records from European and African cities, despite their known presence there. However, there was a strong geographical bias, with 75% of records from Europe. Our results reveal that at the global scale, elevation, and annual variation in temperature and potential evapotranspiration are the most important predictors shaping total earthworm abundance. For total earthworm biomass, variation in potential evapotranspiration is the key predictor. At the plot scale, we found both positive and negative correlations between earthworm community metrics, soil properties, and specific land uses, namely urban forests and grasslands. We recommend additional standardised sampling, broader geographical and temporal coverage, and the investigation of urban-specific direct and indirect stressors, as crucial steps for understanding urban soil biodiversity and promoting beneficial management practices. Overall, this analysis indicates that urbanisation intensity showed no consistent effects on earthworm communities once climate and soil variables were accounted for. Given the importance of climate impacts, mitigation of climate change effects would be valuable for the maintenance of earthworm communities
Innovative gluten-free pasta from cowpea, teff and leafy vegetable: Aligning nutrition with climate smart agriculture
No full textInternational audienceConducted within the European InnofoodAfrica project, this study aimed to develop gluten-free pasta using climate-resilient African Crops to enhance nutrition and sustainability. Four cowpea-based pasta formulations, incorporating teff and/or amaranth leaves were formulated by linear programming, then processed through extrusion and low-temperature drying. These formulations were designed to meet the FAO's nutritional requirements for women, providing adequate protein (both in quantity and quality), fiber, iron, zinc, B9 vitamin and beta-carotene (in versions containing amaranth leaves).The absence of gluten and high fiber content (13-20%- in these flours prompted an investigation into their effects on pasta properties. To ths end, three control pasta samples made from durum wheat with increasing fiber content (4-16%) were developed. Replacing durum wheat entirely with gluten-free, fiber rich flours significantly altered the cowpea pasta's structure, leading to fibrous formulations that disrupted the protein network and resulted in lower covalent protein aggregation (disulfide bonds). Additionally, differences in starch composition and state were observed compared to traditional durum wheat pasta. These structural changes positively influenced nutritional aspects, maintaining or reducing the rapidly digestible starch fraction and preserving or enhancing protein digestibility. Notably, the type of protein (cowpea versus durum wheat) had a more substantial impact on the characteristics of peptides released during digestion than the fiber content. However, attention must be given to the potential allergenicity of these new cowpea-based pasta products.Overall, the study demonstrates that utilizing African crops like cowpea, teff, and amaranth leaves can produce gluten-free pasta with improved nutritional profiles, contributing to sustainable food solutions
Les distinctions architecturales et paysagères à l’épreuve de la transition écologique : Enquête depuis les coulisses du Palmarès des Jeunes Architectes et Paysagistes Ligériens
No full textInternational audienceLes deux dernières décennies nous constatons l’émergence d’une pluralité de prix, palmarès et autres processus de distinction en lien avec les groupes professionnels des architectes, des paysagistes et des urbanistes. Largement diffusés quand le « star système » de l’architecture a été à son apogée, ces processus de distinction ont évolué sur plusieurs aspects : (1) historiquement associés au milieu de l’architecture ils se sont ouvert et diffusés vers d’autres champs professionnels ; (2) en termes d’échelle de référence (distinctions peuvent être régionales, nationales, internationales) ; (3) dans les types de pratiques (maîtrise d’œuvre, recherche, médiation…) ; (4) dans les publics identifiés : “première œuvre”, prix “jeunes”, prix adressés à des publics exclusivement féminins… Les évolutions de ces distinctions révèlent aussi, du moins en partie, les évolutions des manières dont les professionnel·les se positionnent, se représentent et se mettent en scène. De par les thématiques mises en avant et les évolutions de ces processus de distinction, nous pouvons aussi présumer des dynamiques à l'œuvre au sein des groupes professionnels concernés. En cela, l’écologisation des discours et des pratiques, la diversification des places et des métiers occupés ou encore l’évolution des conditions de travail et du cadre d’exercice de la maîtrise d'œuvre semblent ressortir ces dernières années comme des thématiques incontournables. Profitant d’une immersion dans les coulisses d’un palmarès régional promouvant les jeunes professionnel·les en architecture, urbanisme et paysage, nous proposons d’interroger les processus de distinction à l’œuvre. Comment se déroule et qu’est-ce qui se joue au sein d’une arène de distinction ? Comment le processus de sélection donne des clés de compréhension des transitions et notamment de l'écologisation des pratiques et des discours (Dacheux-Auzière et Petit-Berghem, 2017 ; Rodde, 2023) mais aussi à la diversification des métiers et la remise en question du cadre et des conditions d’exercice auxquelles les jeunes professionnel·les, et plus largement les trois groupes professionnels des architectes, des urbanistes et des paysagistes, font face ? Observe-t-on des variations dans la manière de traiter les transitions en œuvre et notamment la transition écologique au sein de ces trois groupes professionnels ? Cette communication s’appuie sur une étude de cas : le Palmarès 2025 des Jeunes Architectes et Paysagistes Ligériens (JAPL). Elle s’inscrit dans l’axe 3 du projet ANR ProMetUrba21. Elle repose : (1) sur une mise en perspective socio-historique de l’usage des prix et distinctions dans le champ de la fabrique des espaces habités à partir de la littérature existante (cf. Biau, 1996 et 2000; Molina, 2014; Chadoin 2013 et 2021) ; (2) sur une observation participante conduite par trois chercheurs·ses, respectivement au jury et au commissariat de sélection 2025 du prix des JAPL. Cette immersion permet l’accès à la scène de sélection (le jury), au règlement écrit, aux argumentaires des dossiers de candidature, aux entretiens individuels avec les lauréats, ainsi qu’au séminaire, organisé par le commissariat et permettant la rencontre entre les lauréats. En cela la communication interrogera la manière dont les transitions et notamment la transition écologique est présente dans ce processus de distinction depuis la manière dont les candidats composent leurs dossiers de candidature, jusqu’à la manière dont opère le jury de sélection en passant par la mise en récit de soi
Co-concevoir des systèmes agro-écologiques couplant volailles/cultures afin de favoriser les services (éco)systémiques et identifier les besoins génétiques pour les volailles de ces systèmes
No full textInternational audienceCo-concevoir des systèmes agro-écologiques couplant volailles/cultures afin de favoriser les services (éco)systémiques et identifier les besoins génétiques pour les volailles de ces systèmes
Co-designing agroecological systems combining poultry and plants to enhance (eco)system services and identify genetic needs for poultry
No full textInternational audienceThe agroecological transition requires a better coupling of animal and plant productions to take advantage of reciprocal benefits. However, poultry farming is often disconnected from crop production at both farm and regional levels. Additionally, current breeds and varieties may struggle to adapt to the variable and heterogeneous environments often found in agroecological systems. Furthermore, the agroecological transition requires a shift in research practices, including the active engagement of non-scientific stakeholders to ensure effective field implementation.In this context, this study aimed to co-design agroecological systems integrating poultry with crops or fruit trees to enhance ecosystem services. The goal was to refine breeding objectives and optimize poultry sector organization in terms of feeding, genetics, and economics. To achieve this, we conducted semi-structured interviews with farmers across France who are experimenting with innovative practices in more integrated systems.Initial findings show that poultry-crop systems offer multiple benefits, including diversification, food autonomy, and biological pest control. However, they also present challenges, particularly due to unsuitable regulations and equipment. While farmers’ satisfaction with current poultry genetics varies, all farmers seek greater independence from dominant industry players. Achieving this goal necessitates collaboration between, breeders, farmers and local stakeholders at the regional level.Building on this observation, we applied the DKCP (Define-Knowledge-Concept-Proposal) method to facilitate knowledge sharing and explore innovative ideas during a codesign process. This phase involved a group of organic farmers in the Massif Central, a mid-altitude region in central France
Taking fear back into the marginal value theorem: the rMVT and optimal boldness
No full textInternational audienceForagers exploiting heterogeneous habitats make strategic movement decisions to maximize fitness. Charnov's marginal value theorem (MVT) models the sequential visit of habitat patches and their distribution to predict the optimal time allocation strategy. However, it notoriously ignores the effects of predation risk. Brown's giving-up density (GUD) theory is an alternative that includes predation risk. However, it is more abstract and does not have the specificity or graphical appeal of the MVT. Here, we formally introduce the rMVT (r stands for risk), a generalization of the MVT that incorporates predation risks. The rMVT retains the structure and graphical simplicity of the MVT, but implies a shift from residence time to expected dose of risk (micromorts) as the domain over which rate maximization occurs. We show that the rMVT can handle most types of risk, whereas the GUD theory is valid only for specific forms of risk. Applications of the rMVT show that different types of risk can yield opposite responses of optimal strategies to an increase in the risk level, and predict differential behavioral responses observed in experimental vs. natural conditions. The rMVT also predicts the optimal level of risk-taking, or "optimal boldness," and suggests that individuals should generally be bolder in riskier habitats
Assessment of the role of greenhouse borders as sources of pest and beneficial insects in protected crops
No full textInternational audienceManaging pests in greenhouses and other sheltered crops requires understanding the origin of colonizing individuals. Nearby vegetation can serve as a source not only for pest insects but also for their natural enemies, making it a key factor in developing conservation biological control strategies. We conducted a study on protected strawberry crops across 50 French farms, examining the presence of major pests and their natural enemies in both greenhouses and crop border vegetation. We first identified pest and beneficial insects in greenhouses and then determined whether these insects were present in crop border vegetation. Our results showed that while crop borders primarily harboured generalist aphid species, aphids specialized in strawberry were nearly absent. Few phytophagous bugs were observed in either sampling sites. In contrast, natural enemies, such as aphid parasitoids and generalist predators, were found in both greenhouses and borders. We further analysed how factors such as seasonality, production region, surrounding vegetation characteristics influenced the presence of pest and beneficial insects in crop borders. The presence of Rosaceae plants (strawberry's botanical family) had no effect on insect populations. Higher botanical diversity and vegetation cover in borders were associated with increased populations of generalist pests and some biological control agents. These findings highlight the crucial role of crop borders in providing resources and refuges for generalist pest and beneficial insects while having limited impact on specialized pest populations. Targeted border management could either prevent pest colonization of crops or enhance natural enemy populations, contributing to improved pest regulation in greenhouses
Avis de l'Anses relatif à « la catégorisation de Cordylomera spinicornis »
No full textCitation suggérée : Anses. (2024). Catégorisation de Cordylomera spinicornis. (saisine 2023-SA-0028). Maisons-Alfort : Anses, 18 p.L’Anses a été saisie le 27 janvier 2023 par la direction générale de l’alimentation du ministère de l’agriculture et de la souveraineté alimentaire pour la réalisation de l’expertise suivante : Catégorisation de huit espèces d’insectes exotiques dont Cordylomera spinicornis.CONTEXTE ET OBJET DE LA SAISINEDans le cadre de la surveillance des organismes réglementés ou émergents (SORE), un dispositif de piégeage a été déployé par la DGAL en 2021 avec l’appui de l’INRAE et de l’ONF. L’objectif de ce dispositif est d’effectuer une surveillance passive dans les sites d’entrée ,potentiels (ports, aéroports, marché d’intérêt national (MIN)) des organismes réglementés ou émergents. Ce piégeage est qualifié de « large spectre » car il peut concerner plusieurs filières, de production suivies dans le cadre de la SORE (forêts, jardins et espaces verts et ,infrastructures (JEVI), arboriculture fruitière) en ciblant cependant majoritairement les insectes coléoptères des ligneux.Les principes de la surveillance mise en œuvre s’appuient sur les résultats précédemment acquis dans le cadre du projet PORTRAP, utilisant des pièges génériques multi-composés pour la détection précoce d’insectes exotiques xylophages dans les sites potentiels d’entrée sur le territoire national.Les pièges ont été disposés sur 13 sites (7 ports maritimes, 1 port fluvial, 4 aéroports et 1 marché national) dispersés sur le territoire (France continentale).Au total 9279 individus appartenant à 110 espèces différentes ont été capturés. Aucune espèce d’insecte de quarantaine prioritaire n’a été piégée. En revanche, la présence d’individus appartenant à 8 espèces de coléoptères exotiques, à priori non répandues sur notre territoire, des familles Cerambycidae et Curculionidae (sous-familles des Scolytinae et Platypodinae) a été relevée.Les 8 espèces d’insectes exotiques sont les suivantes :Cerambycidae : Cordylomera spinicornis (Fabricius, 1775), Trichoferus campestris (Faldermann, 1835), Xylotrechus chinensis (Chevrolat, 1852), Xylotrechus stebbingi Gahan, 1906 ; Curculionidae : Amasa sp. near truncata, Euplatypus hintzii (Schaufuss, 1897), Euplatypus parallelus (Fabricius, 1801), Xyleborus affinis Eichhoff, 1868.Ainsi, il est demandé la réalisation d’une catégorisation des 8 espèces d’insectes exotiques en utilisant les critères de risque listés ci-dessous, afin de déterminer leur nuisibilité et de prioriser sur cette base la réalisation d’analyses de risque portant sur ces insectes.Critères de risquea. Caractéristiques des espèces• Cycle biologique,• Plantes hôtes,• Symptômes,• Aires de distribution,• Nuisibilité dans ces aires de distribution,• Probabilité d’entrée et de transfert vers les plantes hôtes.b. Probabilité d’établissement• Présence d’hôtes appropriés, conditions climatiques et autres facteurs abiotiques favorables à l’établissement des 8 espèces d’insecte dans la zone ARP,• Identification d’ennemis naturels potentiels dans la zone ARP, et d’autres facteurs biotiques ainsi que les pratiques culturales pouvant contribuer à empêcher leur établissement,• Définition des zones d’établissement potentielles dans la zone ARP.c. Probabilité de dissémination• Moyens de dissémination (naturelle et assistée) dans la zone ARP,• Magnitude de la dissémination des 8 espèces d’insecte.d. Conséquences potentielles• Évaluation de l’impact économique en terme de production, associé aux 8 espèces d’insectes pour l’agriculture, la sylviculture et l’horticulture dans leur zone de répartition géographique actuelle et dans la zone ARP,• Évaluation de l’impact en JEVI dans la zone ARP.e. Conclusions des catégorisations des organismes nuisiblesDans cet avis, la catégorisation de Cordylomera spinicornis sera présenté