Résumé
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
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Mycorrhizal fungi or endphytes colonize plant roots and their occurrence and composition depend on biotic and abiotic characteristics of the ecosystem. We investigated the composition of these microbial communities associated with Festuca paniculata, a slow growing species, which dramatically impacts functional plant diversity and the recycling of organic matter in subalpine grasslands. F. paniculata individuals from both mown and unmown grasslands were randomly collected and the microscopic observation of the plant roots revealed a difference in fungal colonization according to management. The ITS regions of root-associated fungi were amplified, cloned and sequenced. Bioinformatic analysis revealed a total of 43 and 35 phylotypes in mown and unmown grasslands respectively, highlighting a remarkable difference in the composition between both fungal communities. The phylotypes were assigned to 9 classes in which two classes Eurotiomycetes and Lecanoromycetes were specific to mown grasslands, while Tremellomycetes were specific to unmown grasslands and only five phylotypes were common to both locations. The comparative analysis of fungal lifestyles indicated the dominance of saprobes and a large proportion of endophytes compared to the mycorrhizal fungi (7/1 and 11/2 phylotypes in mown and unmown grasslands, respectively). Endophyte richness was greater in the unmown gassland than in the mown grassland and their relative proportion was twice higher. Our results suggest that endophytes may offer potential resources to F. paniculata and play an important role in the regulation of plant diversity.
Auteurs, date et publication :
Auteurs Bello Mouhamadou , Claire Molitor , Florence Baptist , Lucile Sage , Jean-Christophe Clément , Sandra Lavorel , Armelle Monier , Roberto A. Geremia
Publication : Fungal Diversity
Date : 2011
Volume : 47
Issue : 1
Pages : 55-63
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Foundation plants shape the composition of local biotic communities and abiotic environments, but the impact of a plant’s intraspecific variations on these processes is poorly understood. We examined these links in the alpine cushion moss campion (Silene acaulis) on two neighboring mountain ranges in the French Alps. Genotyping of cushion plants revealed two genetic clusters matching known subspecies. The exscapa subspecies was found on both limestone and granite, while the longiscapa one was only found on limestone. Even on similar limestone bedrock, cushion soils from the two S. acaulis subspecies deeply differed in their impact on soil abiotic conditions. They further strikingly differed from each other and from the surrounding bare soils in fungal community composition. Plant genotype variations accounted for a large part of the fungal composition variability in cushion soils, even when considering geography or soil chemistry, and particularly for the dominant molecular operational taxonomic units (MOTUs). Both saprophytic and biotrophic fungal taxa were related to the MOTUs recurrently associated with a single plant genetic cluster. Moreover, the putative phytopathogens were abundant, and within the same genus (Cladosporium) or species (Pyrenopeziza brassicae), MOTUs showing specificity for each plant subspecies were found. Our study highlights the combined influences of bedrock and plant genotype on fungal recruitment into cushion soils and suggests the coexistence of two mechanisms, an indirect selection resulting from the colonization of an engineered soil by free‐living saprobes and a direct selection resulting from direct plant–fungi interactions.
Auteurs, date et publication :
Auteurs Julien Roy , Jean-Marc Bonneville , Patrick Saccone , Sébastian Ibanez , Cécile H. Albert , Marti Boleda , Maya Gueguen , Marc Ohlmann , Delphine Rioux , Jean-Christophe Clément , Sébastien Lavergne , Roberto A. Geremia
Publication : Ecology and Evolution
Date : 2025
Volume : 8
Issue : 23
Pages : 11568-11581
Catégorie(s)
#CNRS #Lautaret #UGAAuteurs, date et publication :
Auteurs Kaina Privet , Julien Petillon
Date : 2025
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Volatile terpenes are among the most diverse class of defensive compounds in plants, and they are implicated in both direct and indirect defense against herbivores. In terpenes, both the quantity and the diversity of compounds appear to increase the efficiency of defense as a diverse blend of compounds provides a more efficient protection against a broader range of herbivores and limits the chances that an enemy evolves resistance. Theory predicts that plant defensive compounds should be allocated differentially among tissues according to the value of the tissue, its cost of construction and the herbivore pressure on it. We collected volatile terpenes from bark and leaves of 178 individual tree belonging to 55 angiosperm species in French Guiana and compare the kind, amount, and diversity of compounds in these tissues. We hypothesized that in woody plants, the outermost part of the trunk should hold a more diverse blend of volatile terpenes. Additionally, as herbivore communities associated with the leaves is different to the one associated with the bark, we also hypothesized that terpene blends should be distinct in the bark vs. the leaves of a given species. We found that the mixture of volatile terpenes released by bark is different and more diverse than that released by leaves, both in monoterpenes and sesquiterpenes. This supports our hypothesis and further suggests that the emission of terpenes by the bark should be more important for trunk defense than previously thought.
Auteurs, date et publication :
Auteurs Elodie A. Courtois , Christopher Baraloto , C.E. Timothy Paine , Pascal Petronelli , Pierre-Alain Blandinieres , Didier Stien , Emeline Höuel , Jean-Marie Bessière , Jérôme Chave
Publication : Phytochemistry
Date : 2012
Volume : 82
Pages : 81–88
Catégorie(s)
#CIRAD #CNRS #FORET Nouragues #FORET ParacouAuteurs, date et publication :
Auteurs Bibiana Rojas , Petri Rautiala , Johanna Mappes
Publication : Behavioural processes
Date : 2025
Volume : 109
Pages : 164-172
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Abstract. 3-hydroxy fatty acids (3-OH FAs) with 10 to 18 C atoms are membrane lipids mainly produced by Gram-negative bacteria. They have been recently proposed as temperature and pH proxies in terrestrial settings. Nevertheless, the existing correlations between pH/temperature and indices derived from 3-OH FA distribution (RIAN, RAN15 and RAN17) are based on a small soil dataset (ca. 70 samples) and only applicable regionally. The aim of this study was to investigate the applicability of 3-OH FAs as mean annual air temperature (MAAT) and pH proxies at the global level. This was achieved using an extended soil dataset of 168 topsoils distributed worldwide, covering a wide range of temperatures (5 °C to 30 °C) and pH (3 to 8). The response of 3-OH FAs to temperature and pH was compared to that of established branched GDGT-based proxies (MBT'5Me/CBT). Strong linear relationships between 3-OH FA-derived indices (RAN15, RAN17 and RIAN) and MAAT/pH could only be obtained locally, for some of the individual transects. This suggests that these indices cannot be used as paleoproxies at the global scale using simple linear regression models, in contrast with the MBT'5Me and CBT. However, strong global correlations between 3-OH FA relative abundances and MAAT/pH were shown by using other algorithms (multiple linear regression, k-NN and random forest models). The applicability of the k-NN and random forest models for paleotemperature reconstruction was tested and compared with the MAAT record from a Chinese speleothem. The calibration based on the random forest model appeared to be the most robust. It showed similar trends with previously available records and highlighted known climatic events poorly visible when using local 3-OH FA calibrations. Altogether, these results demonstrate the potential of 3-OH FAs as paleoproxies in terrestrial settings.
Auteurs, date et publication :
Auteurs Pierre Véquaud , Sylvie Derenne , Alexandre Thibault , Christelle Anquetil , Giuliano Bonanomi , Sylvie Collin , Sergio Contreras , Andrew Nottingham , Pierre Sabatier , Norma Salinas , Wesley Philip Scott , Josef P. Werne , Arnaud Huguet
Publication : Biogeosciences Discussions
Date : 2020
Pages : 1-40
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Life history changes may change resource use. Such shifts are not well understood in the dung beetles, despite recognised differences in larval and adult feeding ability. We use the flightless dung beetle Circellium bacchus to explore such shifts, identifying dung sources of adults using DNA metabarcoding, and comparing these with published accounts of larval dung sources. C. bacchus is traditionally considered to specialise on the dung of large herbivores for both larval and adult feeding. We successfully extracted mammal DNA from 151 adult C. bacchus fecal samples, representing 16 mammal species (ranging from elephants to small rodents), many of which are hitherto undescribed in the diet. Adult C. bacchus showed clear dung source preferences, especially for large herbivores inhabiting dense-cover vegetation. Our approach also confirmed the presence of cryptic taxa in the study area, and we propose that this may be used for biodiversity survey and monitoring purposes. Murid rodent feces were the most commonly fed-upon dung source (77.5%) for adult C. bacchus, differing markedly from the large and megaherbivore dung sources used for larval rearing. These findings support the hypothesis of life history-specific shifts in resource use in dung beetles, and reveal a hitherto unsuspected, but ecologically important, role of these dung beetles in consuming rodent feces. The differences in feeding abilities of the larval and adult life history stages have profound consequences for their resource use and foraging strategies, and hence the ecological role of dung beetles. This principle and its ecological consequences should be explored in other scarabaeids.
Auteurs, date et publication :
Auteurs Graham I H Kerley , Marietjie Landman , Gentile F Ficetola , Frédéric Boyer , Aurélie Bonin , Delphine Rioux , Pierre Taberlet , Eric Coissac
Publication : Oecologia
Date : 2025
Volume : 188
Issue : 1
Pages : 107–115
Catégorie(s)
#CNRS #eDNARésumé
To better understand the evolutionary significance of symbiotic interactions in nature, microbiome studies can help to identify the ecological factors that may shape host-associated microbial communities. In this study we explored both 16S and 18S rRNA microbial communities of D. armigerum from both wild caught individuals collected in the Amazon and individuals kept in the laboratory and fed on controlled diets. We also investigated the role of colony, sample type, development and caste on structuring microbial communities. Our bacterial results (16S rRNA) reveal that (1) there are colony level differences between bacterial communities; (2) castes do not structure communities; (3) immature stages (brood) have different bacterial communities than adults; and 4) individuals kept in the laboratory with a restricted diet showed no differences in their bacterial communities from their wild caught nest mates, which could indicate the presence of a stable and persistent resident bacterial community in this host species. The same categories were also tested for microbial eukaryote communities (18S rRNA), and (5) developmental stage has an influence on the diversity recovered; (6) the diversity of taxa recovered has shown this can be an important tool to understand additional aspects of host biology and species interactions.
Auteurs, date et publication :
Auteurs Manuela O. Ramalho , Christophe Duplais , Jérôme Orivel , Alain Dejean , Joshua C. Gibson , Andrew V. Suarez , Corrie S. Moreau
Publication : Scientific Reports
Date : 2025
Volume : 10
Issue : 1
Pages : 7350
Catégorie(s)
#ANR-Citation #CNRS #FORET NouraguesAuteurs, date et publication :
Auteurs Jean-François Humbert , Kamel Soudani , Gabriel Hmimina , Louise Audebert , Stéphane Buttigieg , Patrice Chatellier , Simon Chollet , Beatriz Decencière , François Derkx , Catherine Freissinet , others
Date : 2025