Résumé
The induction of general plant defense responses following the perception of external elicitors is now regarded as the first level of the plant immune response. Depending on the involvement or not of these molecules in pathogenicity, this induction of defense is called either Pathogen-Associated Molecular Pattern (PAMP) Triggered Immunity or Pattern Triggered Immunity—both abbreviated to PTI. Because PTI is assumed to be a widespread and stable form of resistance to infection, understanding the mechanisms driving it becomes a major goal for the sustainable management of plant-pathogen interactions. However, the induction of PTI is complex. Our hypotheses are that (i) the recognition by the plant of PAMPs vs non-PAMP elicitors leads to specific defense profiles and (ii) the responses specifically induced by PAMPs target critical life history traits of the pathogen that produced them. We thus analyzed, using a metabolomic approach coupled with transcriptomic and hormonal analyses, the defense profiles induced in potato foliage treated with either a Concentrated Culture Filtrate (CCF) from Phytophthora infestans or two non-PAMP preparations, β-aminobutyric acid (BABA) and an Ulva spp. Extract, used separately. Each elicitor induced specific defense profiles. CCF up-regulated sesquiterpenes but down-regulated sterols and phenols, notably α-chaconine, caffeoyl quinic acid and rutin, which decreased spore production of P. infestans in vitro. CCF thus induces both defense and counter-defense responses. By contrast, the Ulva extract triggered the synthesis of a large-spectrum of antimicrobial compounds through the phenylpropanoid/flavonoid pathways, while BABA targeted the primary metabolism. Hence, PTI can be regarded as a heterogeneous set of general and pathogen-specific responses triggered by the molecular signatures of each elicitor, rather than as a uniform, non-specific and broad-spectrum set of general defense reactions.
Auteurs, date et publication :
Auteurs Rafaela Lopes Martin , Pauline Le Boulch , Pauline Clin , Adrián Schwarzenberg , Jean-Claude Yvin , Didier Andrivon , Eric Nguema-Ona , Florence Val
Publication : PLOS ONE
Date : 2025
Volume : 15
Issue : 8
Pages : e0236633
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
The infrastructure for Analysis and Experimentation on Ecosystems (AnaEE-France) is an integrated network of the major French experimental, analytical, and modeling platforms dedicated to the biological study of continental ecosystems (aquatic and terrestrial). This infrastructure aims at understanding and predicting ecosystem dynamics under global change. AnaEE-France comprises complementary nodes offering access to the best experimental facilities and associated biological resources and data: Ecotrons, seminatural experimental platforms to manipulate terrestrial and aquatic ecosystems, in natura sites equipped for large-scale and long-term experiments. AnaEE-France also provides shared instruments and analytical platforms dedicated to environmental (micro) biology. Finally, AnaEE-France provides users with data bases and modeling tools designed to represent ecosystem dynamics and to go further in coupling ecological, agronomical, and evolutionary approaches. In particular, AnaEE-France offers adequate services to tackle the new challenges of research in ecotoxicology, positioning its various types of platforms in an ecologically advanced ecotoxicology approach. AnaEE-France is a leading international infrastructure, and it is pioneering the construction of AnaEE (Europe) infrastructure in the field of ecosystem research. AnaEE-France infrastructure is already open to the international community of scientists in the field of continental ecotoxicology.
Auteurs, date et publication :
Auteurs Christian Mougin , Didier Azam , Thierry Caquet , Nathalie Cheviron , Samuel Dequiedt , Jean-François Le Galliard , Olivier Guillaume , Sabine Houot , Gérard Lacroix , François Lafolie , Pierre-Alain Maron , Radika Michniewicz , Christian Pichot , Lionel Ranjard , Jacques Roy , Bernd Zeller , Jean Clobert , André Chanzy
Publication : Environmental Science and Pollution Research
Date : 2015
Volume : 22
Issue : 20
Pages : 16215-16228
Catégorie(s)
#ANR-Citation #BiochemEnv #CNRS #Coordination AnaEERésumé
Cushion plants have long fascinated botanists for their ability to cope with extreme environments in most mountains and arctic regions of the world. One century ago, a first worldwide catalogue of species forming cushions was published by Hauri and Schröter (Bot Jahrb Syst Pflanzengesch Pflanzengeogr 50:618–656, 1914). Here, we defined a simplified typology of cushion plants and updated the worldwide catalogue of cushion species, along with information on their geographic distribution. This compilation was based on available information in floras and catalogues but also in efloras and virtual encyclopedias, which were screened using automated database queries. We established a list of 1,309 cushion-forming species distributed in 272 genera and 63 families of angiosperms. Compact cushions are represented by 678 species, among which 587 species exhibit a hemispherical shape, and 91 species exhibit a flat to mat shape. We found 398 species forming non-compact hemispherical cushions. The list of cushion species has significantly increased since Hauri and Shröter, due to the description of new species, updated regional inventories, and improved access to electronic databases. Uncertainties in the delineation of the cushion life form are discussed, notably for non-compact growth forms. A website has been launched to display the catalogue and enable a collaborative improvement of the database (http://www.cushionplants.eu/). The distribution of the species is presented on the basis of the world geographical scheme for recording plant distributions and global biodiversity information facility data. This catalogue will serve as a reference database for further analyses on the biogeography and evolutionary history of cushion plants and arctico-alpine biotas.
Auteurs, date et publication :
Auteurs Serge Aubert , Florian Boucher , Sébastien Lavergne , Julien Renaud , Philippe Choler
Publication : Alpine Botany
Date : 2014
Volume : 124
Issue : 1
Pages : 59-70
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Continental-scale assessments of 21st century global impacts of climate change on biodiversity have forecasted range contractions for many species. These coarse resolution studies are, however, of limited relevance for projecting risks to biodiversity in mountain systems, where pronounced microclimatic variation could allow species to persist locally, and are ill-suited for assessment of species-specific threat in particular regions. Here, we assess the impacts of climate change on 2632 plant species across all major European mountain ranges, using high-resolution (ca. 100 m) species samples and data expressing four future climate scenarios. Projected habitat loss is greater for species distributed at higher elevations; depending on the climate scenario, we find 36–55% of alpine species, 31–51% of subalpine species and 19–46% of montane species lose more than 80% of their suitable habitat by 2070–2100. While our high-resolution analyses consistently indicate marked levels of threat to cold-adapted mountain florae across Europe, they also reveal unequal distribution of this threat across the various mountain ranges. Impacts on florae from regions projected to undergo increased warming accompanied by decreased precipitation, such as the Pyrenees and the Eastern Austrian Alps, will likely be greater than on florae in regions where the increase in temperature is less pronounced and rainfall increases concomitantly, such as in the Norwegian Scandes and the Scottish Highlands. This suggests that change in precipitation, not only warming, plays an important role in determining the potential impacts of climate change on vegetation.
Auteurs, date et publication :
Auteurs Robin Engler , Christophe F. Randin , Wilfried Thuiller , Stefan Dullinger , Niklaus E. Zimmermann , Miguel B. Araújo , Peter B. Pearman , Gwenaëlle Le Lay , Christian Piedallu , Cécile H. Albert , Philippe Choler , Gheorghe Coldea , Xavier De LAMO , Thomas Dirnböck , Jean-Claude Gégout , Daniel Gómez-García , John-Arvid Grytnes , Einar Heegaard , Fride Høistad , David Nogués-Bravo
Publication : Global Change Biology
Date : 2025
Volume : 17
Issue : 7
Pages : 2330-2341
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Productivity of tropical lowland moist forests is often limited by availability and functional allocation of phosphorus (P) that drives competition among tree species and becomes a key factor in determining forestall community diversity. We used non-target 31P-NMR metabolic profiling to study the foliar P-metabolism of trees of a French Guiana rainforest. The objective was to test the hypotheses that P-use is species-specific, and that species diversity relates to species P-use and concentrations of P-containing compounds, including inorganic phosphates, orthophosphate monoesters and diesters, phosphonates and organic polyphosphates. We found that tree species explained the 59% of variance in 31P-NMR metabolite profiling of leaves. A principal component analysis showed that tree species were separated along PC 1 and PC 2 of detected P-containing compounds, which represented a continuum going from high concentrations of metabolites related to non-active P and P-storage, low total P concentrations and high N:P ratios, to high concentrations of P-containing metabolites related to energy and anabolic metabolism, high total P concentrations and low N:P ratios. These results highlight the species-specific use of P and the existence of species-specific P-use niches that are driven by the distinct species-specific position in a continuum in the P-allocation from P-storage compounds to P-containing molecules related to energy and anabolic metabolism.
Auteurs, date et publication :
Auteurs Albert Gargallo-Garriga , Jordi Sardans , Joan Llusià , Guille Peguero , Dolores Asensio , Romà Ogaya , Ifigenia Urbina , Leandro Van Langenhove , Lore T. Verryckt , Elodie A. Courtois , Clément Stahl , Oriol Grau , Otmar Urban , Ivan A. Janssens , Pau Nolis , Miriam Pérez-Trujillo , Teodor Parella , Josep Peñuelas
Publication : Molecules
Date : 2020
Volume : 25
Issue : 17
Pages : 3960
Catégorie(s)
#ANR-Citation #CIRAD #CNRS #FORET NouraguesAuteurs, date et publication :
Auteurs Emile Fonty , Corinne Sarthou , Denis Larpin , JEAN‐FRANÇOIS PONGE
Publication : Global Change Biology
Date : 2025
Volume : 15
Issue : 10
Pages : 2360-2374
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Biogeographic delineations within the European temperate mountains remain poorly understood, as there has been little effort to assemble and analyze vegetation relevés covering Pyrenees, Alps, Carpathians and Balkans altogether. Our study tackles this issue by focusing on the widely distributed alpine acidic grasslands dominated by Carex curvula. Cluster analysis of more than 800 vegetation relevés revealed the European-scale spatial patterns of vascular plant diversity in these alpine grasslands. The geographical distribution of floristic clusters was partly congruent with the physiography of European mountains. Southern European ranges (Southern Balkans and Pyrenees) exhibit a high level of endemism and corresponding floristic clusters are well separated from the others. Marked floristic similarities between the Easternmost Alps, the Carpathians, and the Northern Balkans (Stara Planina) supported a major floristic boundary that runs through the Austrian Alps and that is likely the legacy of a shared Quaternary history. Within the Alps, floristic clustering was mainly driven by ecological drivers and not geography. This paper presents the first detailed study of spatial patterns of species distribution within the European Alpine System, based on a comprehensive analysis of within- and between-community species diversity. It shows that the quantitative analysis of large and consistent data sets may question the traditional delineations of biogeographic regions within European mountains.
Auteurs, date et publication :
Auteurs Mihai Puşcaş , Philippe Choler
Publication : Flora - Morphology, Distribution, Functional Ecology of Plants
Date : 2025
Volume : 207
Issue : 3
Pages : 168-178
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Alpine glacier variations are known to be reliable proxies of Holocene climate. Here, we present a terrestrial cosmogenic nuclide (TCN)-based glacier chronology relying on 24 new 10Be exposure ages, which constrain maximum Neoglacial positions of four small to mid-sized glaciers (Rateau, Lautaret, Bonnepierre and Etages) in the Ecrins-Pelvoux massif, southern French Alps. Glacier advances, marked by (mainly lateral) moraine ridges that are located slightly outboard of the Little Ice Age (LIA, c. 12501860 AD) maximum positions, were dated to 4.25 ± 0.44 ka, 3.66 ± 0.09 ka, 2.09 ± 0.10 ka, c. 1.31 ± 0.17 ka and to 0.92 ± 0.02 ka. The ‘4.2 ka advance’, albeit constrained by rather scattered dates, is to our knowledge exposure-dated here for the first time in the Alps. It is considered as one of the first major Neoglacial advance in the western Alps, in agreement with other regional paleoclimatological proxies. We further review Alpine and Northern Hemisphere mid-to-high latitude evidence for climate change and glacier activity concomitant with the ‘4.2 ka event’. The ‘2.1 ka advance’ was not extensively dated in the Alps and is thought to represent a prominent advance in early Roman times. Other Neoglacial advances dated here match the timing of previously described Alpine Neoglacial events. Our results also suggest that a Neoglacial maximum occurred at Etages Glacier 0.9 ka ago, i.e. during the Medieval Climate Anomaly (MCA, c. 850-1250 AD). At Rateau Glacier, discordant results are thought to reflect exhumation and snow cover of the shortest moraine boulders. Overall, this study highlights the need to combine several sites to develop robust Neoglacial glacier chronologies in order to take into account the variability in moraine deposition pattern and landform obliteration and conservation.
Auteurs, date et publication :
Auteurs Melaine Le Roy , Philip Deline , Julien Carcaillet , Irene Schimmelpfennig , Magali Ermini
Publication : Quaternary Science Reviews
Date : 2025
Volume : 178
Pages : 118-138
Catégorie(s)
#CNRS #Lautaret #UGAAuteurs, date et publication :
Auteurs SR Gradstein , A Obregon , C Gehrig , J Bendix
Publication : Tropical Montane Cloud Forests: Science for Conservation and Management
Date : 2025
Pages : 130
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Rationale Producing robust high-frequency time series of raw atmospheric water vapor isotope data using laser spectrometry requires accurate calibration. In particular, the chemical composition of the analyzed sample gas can cause isotope bias. This study assesses the matrix effect on calibrated δ17O, δ18O, δ2H, 17O-excess, and d-excess values of atmospheric water vapor. Methods A Picarro L2140-i cavity ring-down spectrometer with an autosampler and a vaporizer is used to analyze δ17O, δ18O, δ2H, 17O-excess, and d-excess of two water standards. Isotope data obtained using synthetic air and dry ambient air as carrier gas at water mixing ratios ranging from 2000 to 30 000 ppmv are compared. Based on the results, atmospheric water vapor measurements are calibrated. The expected precision is estimated by Monte Carlo simulation. Results The dry air source strongly impacts raw isotope values of the two water standards but has no effect on the mixing ratio dependency functions. When synthetic air is used, δ17O, δ18O, and 17O-excess of calibrated atmospheric water vapor are overestimated by 0.6‰, 0.7‰, and 217 per meg, respectively, whereas δ2H and d-excess are underestimated by 1.5‰ and 7.3‰. Optimum precisions for the calibrated δ17O, δ18O, δ2H, 17O-excess, and d-excess values and 12 min integration time are 0.02‰, 0.03‰, 0.4‰, 14 per meg, and 0.4‰, respectively. Conclusions Regarding the obtained results, recommendations for the calibration of atmospheric water vapor isotope measurements are presented. The necessity to use dry ambient air as dry air source when running the standards for calibration is pointed out as a prerequisite for accurate atmospheric water vapor 17O-excess and d-excess measurements.
Auteurs, date et publication :
Auteurs Claudia Voigt , Christine Vallet-Coulomb , Clément Piel , Anne Alexandre
Publication : Rapid Communications in Mass Spectrometry
Date : 2025
Volume : 36
Issue : 6
Pages : e9227