Résumé
A host-plant and its associated microbiota depend on one another. However, the assembly process and the functioning of host-associated microbiota are poorly understood. Herein, rice was used as model plant to investigate the assemblage of bacterial microbiota, including those in the seed, root endosphere and rhizosphere. We also assessed the degree to which endosphere and rhizosphere communities were influenced by vertical transmission through seed and identified the core microbes that potentially associated with plant phenotypic properties. Plant microhabitat, rather than subspecies type, was the major driver shaping plant-associated bacterial microbiota. Deterministic processes were primarily responsible for community assembly in all microhabitats. The influence of vertical transmission from seed to root-associated bacterial communities appeared to be quite weak (endosphere) or even absent (rhizosphere). A core microbial community composed of 15 generalist species persisted across different microhabitats and represented key connectors in networks. Host-plant functional traits were linked to the relative abundance of these generalist core microbes and could be predicted from them using machine learning algorithms. Overall, bacterial microbiota is assembled by host-plant interactions in a deterministic-based manner. This study enhances our understanding of the driving mechanisms and associations of microbiota in various plant microhabitats and provides new perspectives to improve plant performance.
Auteurs, date et publication :
Auteurs Junjie Guo , Ning Ling , Yong Li , Kaisong Li , Huiling Ning , Qirong Shen , Shiwei Guo , Philippe Vandenkoornhuyse
Publication : New Phytologist
Date : 2025
Volume : 230
Issue : 5
Pages : 2047-2060
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Microorganisms associated with plants are determinant for their fitness, but also in the case of vine grapes, for the quality and quantity of the wine. Plant microbiota is, however highly variable in space despite deterministic recruitment from the soil reservoir. Therefore, understanding the drivers that shape this microbiota is a key issue. Most studies that have analysed microorganisms associated with vines have been conducted at large scales (e.g., over 100 km) and have analysed the bulk soil and the rhizosphere. In this study, we focused on the root-microbiota endosphere, the most intimate fraction of microorganisms associated with plants. We sampled vine roots in 37 fields distributed throughout a vineyard to investigate drivers shaping the grapevine microbiota at the α- (i.e., within-field) and γ- (i.e., between-field) diversity scales. We demonstrated that vine endospheric microbiota differed according to both the edaphic and plant-specific parameters including cultivar type and age. This work supports the idea of an existing microbial terroir occurring within a domain and offers a new perspective for winemakers to include the microbial terroir in their management practices.
Auteurs, date et publication :
Auteurs Marine Biget , Cendrine Mony , Marc Aubry , Olivier Jambon , Achim Quaiser , Véronique Chable , Sabrina Pernet , Philippe Vandenkoornhuyse
Publication : OENO One
Date : 2021
Volume : 55
Issue : 3
Pages : 299-315
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Intraspecific competition at the larval stage is an important ecological factor affecting life-history, adaptation and evolutionary trajectory in holometabolous insects. However, the molecular pathways underpinning these ecological processes are poorly characterized. We reared Drosophila melanogaster at three egg densities (5, 60, and 300 eggs/mL) and sequenced the transcriptomes of pooled third-instar larvae. We also examined emergence time, egg-to-adult viability, adult mass, and adult sex-ratio at each density. Medium crowding had minor detrimental effects on adult phenotypes compared to low density and yielded 24 differentially expressed genes (DEGs), including several chitinase enzymes. In contrast, high crowding had substantial detrimental effects on adult phenotypes and yielded 2107 DEGs. Among these, upregulated gene sets were enriched in sugar, steroid and amino acid metabolism as well as DNA replication pathways, whereas downregulated gene sets were enriched in ABC transporters, taurine, Toll/Imd signaling, and P450 xenobiotics metabolism pathways. Overall, our findings show that larval crowding has a large consistent effect on several molecular pathways (i.e., core responses) with few pathways displaying density-specific regulation (i.e., idiosyncratic responses). This provides important insights into how holometabolous insects respond to intraspecific competition during development.
Auteurs, date et publication :
Auteurs Juliano Morimoto , Marius Wenzel , Davina Derous , Youn Henry , Herve Colinet
Publication : Insect Science
Date : 2025
Volume : n/a
Issue : n/a
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
The hologenome concept considers the entity formed by a host and its microbiota, the holobiont, as new level of hierarchical organization subject to neutral and selective forces. We used grafted plants to formally evaluate the hologenome concept. We analyzed the root-endosphere microbiota of two independent watermelon and grapevine plant systems, including ungrafted and reciprocalgrafting combinations. Grafted and ungrafted hosts harbor markedly different microbiota compositions. Furthermore, the results indicate a non-random assembly of bacterial communities inhabiting the root endosphere of chimeric plants with interactive effect of both the rootstock and scion on the recruitment of microorganisms. Because chimeric plants did not have a random microbiota, the null hypothesis that holobionts assemble randomly and hologenome concept is an intellectual construction only can be rejected. The study supports the relevance of hologenome as biological level of organization and opens new avenues for a better fundamental understanding of plants as holobionts.
Auteurs, date et publication :
Auteurs Marine Biget , Tingting Wang , Cendrine Mony , Qicheng Xu , Lucie Lecoq , Véronique Chable , Kevin R. Theis , Ning Ling , Philippe Vandenkoornhuyse
Publication : iScience
Date : 2025
Volume : 26
Issue : 2
Pages : 106031
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Neonatal maturity depends on the maternal capacity to provide nutrients for foetal growth. This study aimed to investigate the effects of systemic administration of recombinant porcine somatotropin (pST), one of the main regulators of growth and metabolism, to pregnant gilts during late gestation on circulating nutrients and expression levels of genes in liver and skeletal muscle of their 110-day-old foetuses. Gilts received either daily injections of sterile water (control [CTL] group, n = 15) or of 5 mg of pST (pST group, n = 17) from days 90 to 109 of gestation. At day 110 postconceptus, pairs of foetuses (one of small and one of average size within a litter) were selected. Circulating fructose concentrations were greater, but circulating concentrations of urea were lower in pST than in CTL foetuses. Expression levels of genes involved in carbohydrate and lipid metabolism were more affected by pST treatment in liver than in muscle. Hepatic molecular changes suggest an inhibition of energy-consuming processes (glycogen and lipid biosynthesis) and the activation of energy-producing pathway (mitochondrial oxidation) in pST compared to CTL foetuses. Expression levels of some genes involved in intracellular degradation of proteins were greater in the liver of pST foetuses, and combined with lower uremia, this suggests a higher utilisation of protein sources in pST foetuses than in CTL foetuses. In muscle, molecular changes were mainly observed in the IGF-insulin axis. Altogether, pST-treated gilts seem to have a greater ability to support foetal liver development by the reorientation of energy and protein metabolism.
Auteurs, date et publication :
Auteurs F. Gondret , I. Louveau , P. Langendjik , C. Farmer
Publication : animal
Date : 2023
Volume : 17
Issue : 1
Pages : 100691
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Introduction
Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease characterized by exocrine gland dysfunction. No therapeutic strategy is sufficient on its own for the management of dry mouth and therapeutic innovations are required.
Methods
This Predelfi study was a single-center, prospective, comparative, randomized, double-blind, cross-over controlled study with the primary objective of assessing the tolerance to and effectiveness of two adhesive biofilms (containing prebiotics and, sodium alginate, respectively) in patients with pSS and hyposialia (#NCT04206826 in ClinicalTrials.gov). Secondary objectives were to obtain initial data regarding the clinical effectiveness of such biofilms in the improvement of signs and symptoms related to dry mouth and potential changes in the oral microbiota. Ten pSS patients with pSS were included (9 females and 1 male) with a mean age of 58.1 ± 14.0 years.
Results and discussion
Tolerance to the prebiotic and sodium alginate biofilms was assessed by the patients (visual analog scale [VAS] score 66.7 and 87.6, respectively) and the practitioner (90 and 100, respectively). The absolute changes in the VAS scores at the start and end of each treatment period highlighted an improvement in mouth dryness for the sodium alginate versus the prebiotic biofilm. The VAS scores for other parameters (mouth burning sensation; taste alteration; chewing; swallowing and speech difficulties) remained globally comparable between the two groups. Unstimulated salivary flow showed no changes regardless of the biofilm used. Regarding the oral microbiota, the sodium alginate biofilm increased the abundance of the Treponema genus, whereas the use of the prebiotic biofilm as the first treatment increased the abundance of the genera Veillonella and Prevotella. Nevertheless, the prebiotic biofilm appeared to stimulate “milder” genera with regard to periodontal infections. Furthermore, pre-treatment with the prebiotic biofilm prevented the emergence of the Treponema genus induced by subsequent treatment with the sodium alginate biofilm, suggesting a potential protective effect.
Auteurs, date et publication :
Auteurs Marie Orliaguet , Shao Bing Fong , Laëtitia Le Pottier , Vincent Meuric , Sylvie Boisramé , Martine Bonnaure-Mallet , Jacques-Olivier Pers
Publication : Frontiers in Microbiology
Date : 2023
Volume : 14
Pages : 1071683
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Microalgae remain an exciting target for biotechnology as they offer a largely unexploited reservoir of novel and valuable bioactive compounds. Strain improvement programs are an expanding research field aiming to multiply microalgal potential. This study evaluates the genetic diversity created in populations of the diatom Phaeodactylum tricornutum subjected to random mutagenesis. We explored the genetic diversity using genotyping-by-sequencing (GBS) to estimate and compare the impact of the most common chemical mutagen (ethyl methanesulfonate, EMS). Five microalga populations obtained following EMS treatment had survival rates between 1 and 98 %. High genetic diversity was obtained for only one of these P. tricornutum populations, with a survival rate close to 30 %.
Auteurs, date et publication :
Auteurs Judith Rumin , Grégory Carrier , Catherine Rouxel , Aurélie Charrier , Virginie Raimbault , Jean-Paul Cadoret , Gaël Bougaran , Bruno Saint-Jean
Publication : Algal Research
Date : 2023
Volume : 74
Pages : 103148
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Weaning is a critical period for pigs. Some plant extracts showing antioxidant, anti-inflammatory or anti-bacterial properties, provided to piglets and/or their dam, may improve piglets' robustness at weaning, thus reducing the need for antobiotics. This study investigated the effects of a maternal and/or a direct supplementation of piglets with a combination of plant extracts on sow and piglet performance and their metabolic, immune, inflammatory and oxidative status during lactation and around weaning. Sixty-four sows were assigned to the control or treated group. Treated sows were supplemented with a powdered plant extracts supplement daily top-dressed on feed from day of gestation (DG) 106 to day of lactation (DL) 28 and a liquid solution top-dressed on feed on DG109. Within each sow group, litters were divided into two groups: a control piglet group and a treated piglet group. A single dose of a liquid solution was orally given to piglets in the treated piglet group. Piglets were weaned on DL28. Blood samples were collected from sows on DG94, DG112 and DL26 and from 2 piglets per litter on DL3, DL14, DL25 and 5 d post-weaning to analyze indicators of metabolic, immune, inflammatory and oxidative status. Colostrum and milk samples were collected at farrowing, DL6 and 26. Maternal supplementation had no effect on sow metabolic, immune, inflammatory and oxidative status except for fewer lymphocytes on DG112 (P < 0.05) and a lower plasma concentration of non-esterified fatty acids on DL26 (P < 0.05). Maternal supplementation tended to decrease dry matter and gross energy (P < 0.10) and reduced fat and haptoglobin concentrations (P < 0.01) in milk on DL26. Maternal supplementation had no effect on piglets' growth performance and blood indicators during lactation and around weaning. On DL25, the direct supplementation of piglets decreased their neutrophils proportion (P < 0.05), increased the expression of genes encoding pro- and anti-inflammatory cytokines in whole blood culture in response to LPS (P < 0.05) and tended to decrease the oxidative stress index (P = 0.06). After weaning, these beneficial effects were no longer observed but the supplementation improved piglets' growth performance during the post-weaning period (P < 0.05). Plant extract supplementation could thus modify the composition of mammary secretions and improve post-weaning performance of piglets potentially related to the modification of their immune and oxidative status before weaning.
Auteurs, date et publication :
Auteurs Lucile Herve , Hélène Quesnel , Amaury Greuter , Laurent Hugonin , Elodie Merlot , Nathalie Le Floc'h
Publication : Journal of Animal Science
Date : 2023
Pages : skad282
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Landscape heterogeneity is known as a major factor of community structure and composition. Whether this effect of the landscape extends at different scales and particularly at the relevant scale for microorganisms remained to be determined. We used th
Auteurs, date et publication :
Auteurs Joey Allen , Marion Sire , Nadege Belouard , Caroline Gorzerino , Marie-Agnes Coutellec , Cendrine Mony , Alexandrine Pannard , Christophe Piscart
Date : 2025
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Abstract
The human milk (HM) microbiota, a highly diverse microbial ecosystem, is thought to contribute to the health benefits associated with breastfeeding, notably through its impact on infant gut microbiota. Our objective was to further explore the role of HM bacteria on gut homeostasis through a “disassembly/reassembly” strategy. HM strains covering the diversity of HM cultivable microbiota were first characterized individually and then assembled in synthetic bacterial communities (SynComs) using two human cellular models, peripheral blood mononuclear cells (PBMC) and a quadricellular model mimicking intestinal epithelium. Selected HM bacteria displayed a large range of immunomodulatory properties and had variable effects on epithelial barrier, allowing their classification in functional groups. This multispecies characterization of HM bacteria showed no clear association between taxonomy and HM bacteria impacts on epithelial immune and barrier functions, revealing the entirety and complexity of HM bacteria potential. More importantly, the assembly of HM strains in two SynComs with similar taxonomic composition but with strains that exhibited different properties individually, resulted in contrasted impacts on the epithelium, these impacts of SynComs partially diverging from the predicted ones based on individual bacteria. Overall, our results indicate that the functional properties of the HM bacterial community rather than the taxonomic composition itself could play a crucial role in intestinal homeostasis of infants.
Auteurs, date et publication :
Auteurs Charles Le Bras , Lucie Rault , Nolwenn Jacquet , Nathalie Daniel , Victoria Chuat , Florence Valence , Amandine Bellanger , Latifa Bousarghin , Sophie Blat , Yves Le Loir , Isabelle Le Huërou-Luron , Sergine Even
Publication : ISME Communications
Date : 2024
Pages : ycad019