Résumé
In the course of a revision of the New World Ebenaceae for "Flora Neotropica" and some regional floras, specimens from ca. 100 herbaria have been studied. The widespread, very variable, South American Diospyros capreifolia Mart. ex Hiern (synonyms: Maba melinonii Hiern, and D. ubaita B.Walln.) as well as the closely related Peruvian endemic D. dolmen B.Walln. are here presented. Figures, a distribution map, vernacular names, information on habitat, and a list of specimens are included.
Auteurs, date et publication :
Auteurs B Wallnöfer
Publication : Annalen des Naturhistorischen Museums in Wien
Date : 2025
Catégorie(s)
#⛔ No DOI found #CNRS #FORET NouraguesRésumé
Key message Inventory and seasonal variation of terpene emissions from tropical trees in French Guiana: implications for environmental and ecological roles. Abstract A limited understanding of foliar terpene emissions from different tree species is prominent in diverse tropical forests. We conducted a study in French Guiana, screening BVOC emissions from 36 tropical woody species. We focused on 32 species in the dry season and 33 in the wet season, documenting terpene emissions for the first time in some of these tree species. Our findings show that 93.8% emitted terpenes in the dry season, while only 33.3% did so in the wet season. Terpene emissions ranged from 0.01 to 80.9 μg g−1 h−1 in the dry season and 0 to 11.7 μg g−1 h−1 in the wet season, consistent with previous reports. We identified and quantified 23 terpene compounds, including 19 monoterpenes and 4 sesquiterpenes. Additionally, 2 non-terpenoid compounds were detected: 2,2,4,6,6-pentamethylheptane (with no detected emissions in the dry season) and toluene. Among the monoterpenes, the most abundant were α-terpinolene, limonene, α-pinene, β-ocimene, and sabinene. As for sesquiterpenes, β-caryophyllene, α-caryophyllene, and α-copaene were observed during the dry season, while during the wet season, α-terpinolene predominated, followed by limonene, α-pinene, sabinene, β-caryophyllene, and α-copaene. Isoprene was detected in most of the species studied in both seasons. Sesquiterpene emissions displayed a notable phylogenetic pattern, whereas total terpenes and monoterpenes did not; however, total terpenes and monoterpenes exhibited a significant seasonal influence. Our study demonstrates that seasonality strongly influences BVOC production in tropical trees, with higher emissions in the dry season. These findings imply that various factors and conditions influence tree emissions in this tropical forest, affecting their ecological, environmental, and climatic roles, as well as the implementation of atmospheric chemistry models.
Auteurs, date et publication :
Auteurs Joan Llusià , Dolores Asensio , Jordi Sardans , Iolanda Filella , Guille Peguero , Oriol Grau , Romà Ogaya , Ifigenia Urbina , Albert Gargallo-Garriga , Lore T. Verryckt , Leandro Van Langenhove , Laëtitia M. Brechet , Elodie Courtois , Clément Stahl , Ivan A. Janssens , Josep Peñuelas
Publication : Trees
Date : 2025
Volume : 38
Issue : 4
Pages : 997-1012
Catégorie(s)
#CIRAD #CNRS #FORET Nouragues #FORET ParacouRésumé
Slow-growing bacteria, referred as tolerant or persistent, emerge as a major health issue since they are associated with antibiotic treatment failures and relapsing infections. Among others, type I toxin-antitoxin (TA) systems have been linked to slow-growing bacteria formation. They are composed of a peptide toxin whose overexpression confers growth stasis or cell death, and of an RNA antitoxin that base-pairs with the cognate toxin mRNA to inhibit its translation. In the human pathogen Staphylococcus aureus, it was recently shown that the SprF1 antitoxin is able to bind ribosomes to inhibit global translation and promote persister cell formation. Here, we used in silico analysis and MS2-affinity purification coupled with RNA sequencing (MAPS) to expand the RNA targetome of SprF1 and better understand its role in S. aureus antibiotic adaptation. We experimentally uncovered 12 mRNAs targets interacting with SprF1 and demonstrated that SprF1 directly interacts with yidC, encoding a protein insertase, and rpmE2, encoding the ribosomal protein L31, to either decrease or increase their protein expression. Finally, we showed that rpmE2 overexpression is associated with antibiotic tolerance which could contribute to the persister phenotype mediated by SprF1. Altogether, these findings highlight that some type I RNA antitoxins behave like typical regulatory RNAs, by interacting with several targets through various regulatory motifs to participate in bacterial adaptation.
Auteurs, date et publication :
Auteurs Emeline Ostyn , Marc Hallier , Stéphane Dreano , Yoann Augagneur , Marie-Laure Pinel-Marie
Date : 2024
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Identification of individuals in the absence of reproductive traits or in juvenile stages can be difficult. Incorrect identification will result in inaccurate biodiversity inventories that are an impediment to effective conservation management. Here, we present data in which we argue that the generation of DNA barcode reference libraries using DNA extracted from type specimens could resolve issues related to correct identification. The genus Micropholis (Sapotaceae) is diverse and ecologically important in Neotropical lowland rain forests. We first assessed the capacity of the molecular markers ITS2, matK and rbcL in differentiating species in the genus. Based on a phylogenetic reconstruction we found that many individuals in our study were incorrectly identified, and we argue that if we had access to a type specimen DNA barcode reference library we would have more rapidly and correctly identified individuals.
Auteurs, date et publication :
Auteurs Dayana Sánchez‐C. , James E. Richardson , Michelle Hart , Julieth Serrano , Dairon Cárdenas , Mailyn A. Gonzalez , Rocio Cortés‐B.
Publication : TAXON
Date : 2025
Volume : 71
Issue : 1
Pages : 154-167
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Pristimantis is already the most speciose genus among vertebrates, yet the current number of species remains largely underestimated. A member of the P. unistrigatus species group from the Guiana Shield has been historically misidentified as P. ockendeni, a species described from southern Peru. We combined mitochondrial (16S and COI) and nuclear (RAG1) loci, external morphology, skull osteology (mu-CT scan), vocalization (advertisement and courtship calls), geographic distribution and natural history data to differentiate the Guiana Shield populations from P. ockendeni, and describe them as a new species. The new species is crepuscular and nocturnal and inhabits the understory of unflooded (terra firme) forests in Brazil, Guyana and Suriname. It is phylogenetically related to P. ardalonychus, P. martiae and undescribed species from Brazilian Amazonia. The new species notably differs from P. ockendeni and its congeners in the P. unistrigatus species group occurring in the Guiana Shield by the combination of the following characters: absence of dentigerous processes of vomers, presence of vocal slits in males, body size (SVL 16.2-20.7 mm in males and 21.4-25.7 mm in females), advertisement call (call with 4-6 notes, call duration of 158-371 ms and dominant frequency of 3,466-4,521 Hz) and translucent groin coloration in life. To facilitate the recognition and description of cryptic species previously hidden under the name P. ockendeni, we provide an amended diagnosis of this taxon based on external morphology and advertisement call of specimens recently collected nearby the type locality and additional localities in southwestern Amazonia.
Auteurs, date et publication :
Auteurs Alexander Tamanini Monico , Miqueias Ferrao , Juan Carlos Chaparro , Antoine Fouquet , Albertina Pimentel Lima
Publication : VERTEBRATE ZOOLOGY
Date : 2022
Volume : 72
Pages : 1035-1065
Catégorie(s)
#ANR-Citation #CNRS #FORET NouraguesRésumé
The white-sand ecosystems in the Solimoes-Negro Interfluve are among the less studied in Amazonia. Recent herpetological surveys conducted west of Manaus, Brazil (central Amazonia) indicate that white-sand forests host a unique anuran fauna comprising habitat specialized and endemic species. In the present study we describe a new species of rain frog belonging to the Pristimantis unistrigatus species group from the white-sand forest locally called “campinarana”(thin-trunked forests with canopy height below 20 m). The new species is phylogenetically close to rain frogs from western Amazonian lowlands (P. delius, P. librarius, P. matidiktyo and P. ockendeni). It differs from its closest relatives mainly by its size (male SVL of 17.3-20.1 mm, n = 16; female SVL of 23.2-26.5 mm, n = 6), presence of tympanum, tarsal tubercles and dentigerous processes of vomers, its translucent groin without bright colored blotches or marks, and by its advertisement call (composed of 5-10 notes, call duration of 550-1,061 ms, dominant frequency of 3,295-3,919 Hz). Like other anuran species recently discovered in the white-sand forests west of Manaus, the new species seems to be restricted to this peculiar ecosystem.
Auteurs, date et publication :
Auteurs Alexander Tamanini Monico , Miqueias Ferrao , Jiri Moravec , Antoine Fouquet , Albertina P. Lima
Publication : PEERJ
Date : 2023
Volume : 11
Catégorie(s)
#ANR-Citation #CNRS #FORET NouraguesRésumé
Solute exchange between the sediment and the water column strongly influences water quality in aquatic ecosystems. Among the techniques available for in situ observation, only aquatic eddy covariance (AEC) can resolve the hourly dynamics of benthic fluxes, but only for few substances like oxygen. In micrometeorology, relaxed eddy accumulation (REA), a technique based on high-frequency sampling conditioned by current direction, overcomes this limitation. We developed a portable prototype instrumentation platform to transfer REA to the sediment-water interface of shallow aquatic ecosystems. In order to evaluate the sampling system, we configured the prototype for measuring oxygen fluxes and comparing them to simultaneous AEC measurements. In a river and two artificial lakes, at depths 1–3 m and 0.2 m above the sediment, we measured 15 oxygen flux pairs in fully developed turbulence during 8–15 min periods, ranging from −150 to 50 mmol m−2 day−1. The good agreement between REA and AEC fluxes (R2 = 0.94) shows the reliability of the conditional sampling system. REA represents a promising technique for exploring the sediment contribution to biogeochemical cycles in aquatic ecosystems.
Auteurs, date et publication :
Auteurs Guilherme Calabro-Souza , Andreas Lorke , Christian Noss , Philippe Dubois , Mohamed Saad , Celia Ramos-Sanchez , Brigitte Vinçon-Leite , Régis Moilleron , Magali Jodeau , Bruno J. Lemaire
Publication : Earth and Space Science
Date : 2025
Volume : 10
Issue : 9
Pages : e2023EA003041
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
Abstract. The study of isotopic ratios of atmospheric oxygen in fossilized air trapped in ice core bubbles provides information on variations in the hydrological cycle at low latitudes and productivity in the past. However, to refine these interpretations, it is necessary to better quantify fractionation of oxygen in the biological processes such as photosynthesis and respiration. We set up a system of closed biological chambers in which we studied the evolution of elemental and isotopic composition of O2 due to biological processes. To easily replicate experiments, we developed a multiplexing system which we describe here. We compared measurements of elemental and isotopic composition of O2 using two different measurement techniques: optical spectrometry (Optical-Feedback Cavity- Enhanced Absorption Spectroscopy, i.e. OF-CEAS technique), which enables higher temporal resolution and continuous data collection and isotopic ratio mass spectrometry (IRMS) with a flanged air recovery system, thus validating the data analysis conducted through the OF-CEAS technique. As a first application, we investigated isotopic discrimination during respiration and photosynthesis. We conducted a 5-day experiment using maize (Zea mays L.) as model species. The 18O discrimination value for maize during dark plant respiration was determined as - 17.8 ± 0.9 ‰ by IRMS and - 16.1 ± 1.1 ‰ by optical spectrometer. We also found a value attributed to the isotopic discrimination of terrestrial photosynthesis equal to + 3.2 ± 2.6 ‰ by IRMS and + 6.7 ± 3.8 ‰ by optical spectrometer. These findings were consistent with a previous study by Paul et al. (2023).
Auteurs, date et publication :
Auteurs Clémence Paul , Clément Piel , Joana Sauze , Olivier Jossoud , Arnaud Dapoigny , Daniele Romanini , Frédérique Prié , Sébastien Devidal , Roxanne Jacob , Alexandru Milcu , Amaëlle Landais
Date : 2024
Catégorie(s)
#CNRS #Ecotron de MontpellierAuteurs, date et publication :
Auteurs Jason Vleminckx , Claire Fortunel , Oscar Valverde‐Barrantes , CE Timothy Paine , Julien Engel , Pascal Petronelli , Aurélie K Dourdain , Juan Guevara , Solène Béroujon , Christopher Baraloto
Publication : Oikos
Date : 2025
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Global change scenarios in the Mediterranean basin predict a precipitation reduction within the coming hundred years. Therefore, increased drought will affect forests both in terms of adaptive ecology and ecosystemic services. However, how vegetation might adapt to drought is poorly understood. In this report, four years of climate change was simulated by excluding 35% of precipitation above a downy oak forest. RNASeq data allowed us to assemble a genome-guided transcriptome. This led to the identification of differentially expressed features, which was supported by the characterization of target metabolites using a metabolomics approach. We provided 2.5 Tb of RNASeq data and the assembly of the first genome guided transcriptome of Quercus pubescens. Up to 5724 differentially expressed transcripts were obtained; 42 involved in plant response to drought. Transcript set enrichment analysis showed that drought induces an increase in oxidative pressure that is mitigated by the upregulation of ubiquitin-like protein protease, ferrochelatase, oxaloacetate decarboxylase and oxo-acid-lyase activities. Furthermore, the downregulation of auxin biosynthesis and transport, carbohydrate storage metabolism were observed as well as the concomitant accumulation of metabolites, such as oxalic acid, malate and isocitrate. Our data suggest that early metabolic changes in the resistance of Q. pubescens to drought involve a tricarboxylic acid (TCA) cycle shunt through the glyoxylate pathway, galactose metabolism by reducing carbohydrate storage and increased proteolytic activity.
Auteurs, date et publication :
Auteurs Jean-Philippe Mevy , Beatrice Loriod , Xi Liu , Erwan Corre , Magali Torres , Michael Büttner , Anne Haguenauer , Ilja Marco Reiter , Catherine Fernandez , Thierry Gauquelin
Publication : Plants
Date : 2025
Volume : 9
Pages : 1149