Résumé
Abstract Bacteria living on the cuticle of ants are generally studied for their protective role against pathogens, especially in the clade of fungus-growing ants. However, little is known regarding the diversity of cuticular bacteria in other ant host species, as well as the mechanisms leading to the composition of these communities. Here, we used 16S rRNA gene amplicon sequencing to study the influence of host species, species interactions and the pool of bacteria from the environment on the assembly of cuticular bacterial communities on two phylogenetically distant Amazonian ant species that frequently nest together inside the roots system of epiphytic plants, Camponotus femoratus and Crematogaster levior. Our results show that (a) the vast majority of the bacterial community on the cuticle is shared with the nest, suggesting that most bacteria on the cuticle are acquired through environmental acquisition, (b) 5.2% and 2.0% of operational taxonomic units (OTUs) are respectively specific to Ca. femoratus and Cr. levior, probably representing their respective core cuticular bacterial community, and (c) 3.6% of OTUs are shared between the two ant species. Additionally, mass spectrometry metabolomics analysis of metabolites on the cuticle of ants, which excludes the detection of cuticular hydrocarbons produced by the host, were conducted to evaluate correlations among bacterial OTUs and m/z ion mass. Although some positive and negative correlations are found, the cuticular chemical composition was weakly species-specific, suggesting that cuticular bacterial communities are prominently environmentally acquired. Overall, our results suggest the environment is the dominant source of bacteria found on the cuticle of ants.
Auteurs, date et publication :
Auteurs Caroline Birer , Corrie S. Moreau , Niklas Tysklind , Lucie Zinger , Christophe Duplais
Publication : Molecular Ecology
Date : 2025
Volume : 29
Issue : 7
Pages : 1372-1385
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Climate change-induced rainfall reductions in Mediterranean forests negatively affect the decomposition of plant litter through decreased soil moisture. However, the indirect effects of reduced precipitation on litter decomposition through changes in litter quality and soil microbial communities are poorly studied. This is especially the case for fine root litter, which contributes importantly to forests plant biomass. Here we analyzed the effects of long-term (11 years) rainfall exclusion (29% reduction) on leaf and fine root litter quality, soil microbial biomass, and microbial community-level physiological profiles in a Mediterranean holm oak forest. Additionally, we reciprocally transplanted soils and litter among the control and reduced rainfall treatments in the laboratory, and analyzed litter decomposition and its responses to a simulated extreme drought event. The decreased soil microbial biomass and altered physiological profiles with reduced rainfall promoted lower fine root—but not leaf—litter decomposition. Both leaf and root litter, from the reduced rainfall treatment, decomposed faster than those from the control treatment. The impact of the extreme drought event on fine root litter decomposition was higher in soils from the control treatment compared to soils subjected to long-term rainfall exclusion. Our results suggest contrasting mechanisms driving drought indirect effects on above-(for example, changes in litter quality) and belowground (for example, shifts in soil microbial community) litter decomposition, even within a single tree species. Quantifying the contribution of these mechanisms relative to the direct soil moisture-effect is critical for an accurate integration of litter decomposition into ecosystem carbon dynamics in Mediterranean forests under climate change.
Auteurs, date et publication :
Auteurs Pablo García-Palacios , Iván Prieto , Jean-Marc Ourcival , Stephan Hättenschwiler
Publication : Ecosystems
Date : 2016
Volume : 19
Issue : 3
Pages : 490-503
Catégorie(s)
#CNRS #FORET PuechabonAuteurs, date et publication :
Auteurs Kyle G. Dexter , Mathew Lavin , Benjamin M. Torke , Alex D. Twyford , Thomas A. Kursar , Phyllis D. Coley , Camila Drake , Ruth Hollands , R. Toby Pennington
Publication : Proceedings of the National Academy of Sciences
Date : 2017
Volume : 114
Issue : 10
Pages : 2645-2650
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Range shift, a widespread response to climate change, will depend on species abilities to withstand warmer climates. However, these abilities may vary within species and such intraspecific variation can strongly impact species responses to climate change. Facing warmer climates, individuals should disperse according to their thermal optimum with consequences for species range shifts. Here, we studied individual dispersal of a reptile in response to climate warming and preferred temperature using a semi-natural warming experiment. Individuals with low preferred temperatures dispersed more from warmer semi-natural habitats, whereas individuals with higher preferred temperatures dispersed more from cooler habitats. These dispersal decisions partly matched phenotype-dependent survival rates in the different thermal habitats, suggesting adaptive dispersal decisions. This process should result into a spatial segregation of thermal phenotypes along species moving ranges which should facilitate local adaptation to warming climates. We therefore call for range shift models including intraspecific variation in thermal phenotype and dispersal decision.
Auteurs, date et publication :
Auteurs Elvire Bestion , Jean Clobert , Julien Cote
Publication : Ecology Letters
Date : 2025
Volume : 18
Issue : 11
Pages : 1226-1233
Catégorie(s)
#CNRS #Metatron terrestreRésumé
Dispersal is a central biological process tightly integrated into life-histories, morphology, physiology and behaviour. Such associations, or syndromes, are anticipated to impact the eco-evolutionary dynamics of spatially structured populations, and cascade into ecosystem processes. As for dispersal on its own, these syndromes are likely neither fixed nor random, but conditional on the experienced environment. We experimentally studied how dispersal propensity varies with individuals' phenotype and local environmental harshness using 15 species ranging from protists to vertebrates. We reveal a general phenotypic dispersal syndrome across studied species, with dispersers being larger, more active and having a marked locomotion-oriented morphology and a strengthening of the link between dispersal and some phenotypic traits with environmental harshness. Our proof-of-concept metacommunity model further reveals cascading effects of context-dependent syndromes on the local and regional organisation of functional diversity. Our study opens new avenues to advance our understanding of the functioning of spatially structured populations, communities and ecosystems.
Auteurs, date et publication :
Auteurs Julien Cote , Maxime Dahirel , Nicolas Schtickzelle , Florian Altermatt , Armelle Ansart , Simon Blanchet , Alexis S. Chaine , Frederik De Laender , Jonathan De Raedt , Bart Haegeman , Staffan Jacob , Oliver Kaltz , Estelle Laurent , Chelsea J. Little , Luc Madec , Florent Manzi , Stefano Masier , Felix Pellerin , Frank Pennekamp , Lieven Therry
Publication : Ecology Letters
Date : 2025
Volume : 25
Issue : 12
Pages : 2675-2687
Catégorie(s)
#ANR-Citation #CNRS #Metatron terrestreRésumé
High elevation temperate mountains have long been considered species poor owing to high extinction or low speciation rates during the Pleistocene. We performed a phylogenetic and population genomic investigation of an emblematic high-elevation plant clade (Androsace sect. Aretia, 31 currently recognized species), based on plant surveys conducted during alpinism expeditions. We inferred that this clade originated in the Miocene and continued diversifying through Pleistocene glaciations, and discovered three novel species of Androsace dwelling on different bedrock types on the rooftops of the Alps. This highlights that temperate high mountains have been cradles of plant diversity even during the Pleistocene, with in-situ speciation driven by the combined action of geography and geology. Our findings have an unexpected historical relevance: H.-B. de Saussure likely observed one of these species during his 1788 expedition to the Mont Blanc and we describe it here, over two hundred years after its first sighting.
Auteurs, date et publication :
Auteurs Florian C Boucher , Cédric Dentant , Sébastien Ibanez , Thibaut Capblancq , Martí Boleda , Louise Boulangeat , Jan Smyčka , Cristina Roquet , Sébastien Lavergne
Publication : Scientific Reports
Date : 2025
Volume : 11
Issue : 1
Pages : 11128
Catégorie(s)
#CNRS #eDNAAuteurs, date et publication :
Auteurs Blanka Vlasáková , Stefan Jarau
Publication : Plant Ecology
Date : 2025
Volume : 212
Issue : 8
Pages : 1327-1337
Catégorie(s)
#CNRS #FORET NouraguesAuteurs, date et publication :
Auteurs Julien Ruffault , Nicolas K Martin-StPaul , Serge Rambal , Florent Mouillot
Publication : Climatic Change
Date : 2025
Pages : 15
Catégorie(s)
#CNRS #FORET PuechabonAuteurs, date et publication :
Auteurs Florence D. Hulot , Gérard Lacroix , Michel Loreau
Publication : Oikos
Date : 2025
Volume : 123
Issue : 11
Pages : 1291-1300
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
Modern plant breeding and agrosystems artificialization could have altered plants’ ability to filter and recruit beneficial microorganisms in its microbiota. Thus, compared to modern cultivars, we hypothesized that root-endosphere microbiota in modern wheat cultivars are less resistant to colonization by fungi and bacteria and thus more susceptible to also recruit more pathogens. We used an in-field experimental design including six wheat varieties (three ancient vs. three modern) grown in monoculture and in mixture (three replicates each). Endospheric microbiota of wheat roots were analyzed on four individuals sampled randomly in each plot. Composition-based clustering of sequences was then characterized from amplicon mass-sequencing. We show that the bacterial and fungal microbiota composition in wheat roots differed between ancient and modern wheat cultivar categories. However, the responses observed varied with the group considered. Modern cultivars harbored higher richness of bacterial and fungal pathogens than ancient cultivars. Both cultivar types displayed specific indicator species. A synergistic effect was identified in mixtures of modern cultivars with a higher root endospheric mycobiota richness than expected from a null model. The present study shows the effect of plant breeding on the microbiota associated plant roots. The results call for making a diagnosis of the cultivar's endospheric-microbiota composition. These new results also suggest the importance of a holobiont-vision while considering plant selection in crops and call for better integration of symbiosis in the development of next-generation agricultural practices.
Auteurs, date et publication :
Auteurs Solène Mauger , Claire Ricono , Cendrine Mony , Vèronique Chable , Estelle Serpolay , Marine Biget , Philippe Vandenkoornhuyse
Publication : Plant-Environment Interactions
Date : 2025
Volume : 2
Issue : 5
Pages : 235-248