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Glauser, Gaëtan
Nom
Glauser, Gaëtan
Affiliation principale
Email
gaetan.glauser@unine.ch
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Résultat de la recherche
Voici les éléments 1 - 10 sur 29
- PublicationAccès libreExperimental Growth Conditions affect Direct and Indirect Defences in two Cotton Species(2023)
; ; ; ; ; ; Cotton has been used as a model plant to study direct and indirect plant defence against herbivorous insects. However, the plant growing conditions could have an important effect on the outcome of such plant defence studies. We examined how common experimental growth conditions influence constitutive and inducible defences in two species of cotton, Gossypium hirsutum and G. herbaceum. We induced plants by applying caterpillar regurgitant to mechanical wounds to compare the induction levels between plants of both species grown in greenhouse or phytotron conditions. For this we measured defence metabolites (gossypol and heliocides) and performance of Spodoptera frugiperda caterpillars on different leaves, the emission of plant volatiles, and their attractiveness to parasitic wasps. Induction increased the levels of defence metabolites, which in turn decreased the performance of S. frugiperda larvae. Constitutive and induced defence levels were the highest in plants grown in the phytotron (compared to greenhouse plants), G. hirsutum and young leaves. Defence induction was more pronounced in plants grown in the phytotron and in young leaves. Also, the differences between growing conditions were more evident for metabolites in the youngest leaves, indicating an interaction with plant ontogeny. The composition of emitted volatiles was different between plants from the two growth conditions, with greenhouse-grown plants showing more variation than phytotron-grown plants. Also, G. hirsutum released higher amounts of volatiles and attracted more parasitic wasps than G. herbaceum. Overall, these results highlight the importance of experimental abiotic factors in plant defence induction and ontogeny of defences. We therefore suggest careful consideration in selecting the appropriate experimental growing conditions for studies on plant defences. - PublicationAccès libreGenome-wide association mapping reveals genes underlying population-level metabolome diversity in a fungal crop pathogen(2022)
; ; Abstract Background Fungi produce a wide range of specialized metabolites (SMs) involved in biotic interactions. Pathways for the production of SMs are often encoded in clusters of tightly arranged genes identified as biosynthetic gene clusters. Such gene clusters can undergo horizontal gene transfers between species and rapid evolutionary change within species. The acquisition, rearrangement, and deletion of gene clusters can generate significant metabolome diversity. However, the genetic basis underlying variation in SM production remains poorly understood. Results Here, we analyzed the metabolite production of a large population of the fungal pathogen of wheat, Zymoseptoria tritici. The pathogen causes major yield losses and shows variation in gene clusters. We performed untargeted ultra-high performance liquid chromatography-high resolution mass spectrometry to profile the metabolite diversity among 102 isolates of the same species. We found substantial variation in the abundance of the detected metabolites among isolates. Integrating whole-genome sequencing data, we performed metabolite genome-wide association mapping to identify loci underlying variation in metabolite production (i.e., metabolite-GWAS). We found that significantly associated SNPs reside mostly in coding and gene regulatory regions. Associated genes encode mainly transport and catalytic activities. The metabolite-GWAS identified also a polymorphism in the 3′UTR region of a virulence gene related to metabolite production and showing expression variation. Conclusions Taken together, our study provides a significant resource to unravel polymorphism underlying metabolome diversity within a species. Integrating metabolome screens should be feasible for a range of different plant pathogens and help prioritize molecular studies. - PublicationAccès libreA receptor-like protein mediates plant immune responses to herbivore-associated molecular patterns(2020-11-23)
; ; - PublicationAccès libreInfluence of surface water – groundwater interactions on the spatial distribution of pesticide metabolites in groundwater(2020-4)
; ; In groundwater, pesticidemetabolites tend to occurmore frequently and at higher concentrations than their parent pesticides, due to their highermobility and persistence. These properties might also favor their transfer across surface water – groundwater interfaces. However, the effect of surface water – groundwater interactions on the metabolite occurrence in groundwater and pumpingwells has so far received little attention.Weinvestigated the spatial distribution of metabolites in an unconsolidated aquifer, which interacts with two surface water bodies originating from catchments with contrasting land use. We focused onmetabolites of the herbicide chloridazon, namely desphenyl-chloridazon (DPC) and methyl-desphenyl-chloridazon (MDPC) and characterized surface water – groundwater interactions with various environmental tracers (e.g. electrical conductivity, stable water isotopes,wastewater tracers). In zones influenced by a river fromamountainous area,metabolite concentrations were low(median values ≤0.50 μg L−1 for DPC, ≤0.19 μg L−1 forMDPC). In contrast, high concentrations occurred in areas dominated by recharge fromagricultural fields and/or influenced by a streamfroman adjacent intensely farmed catchment (median values up to 1.9 μg L−1 for DPC and up to 0.75 μg L−1 forMDPC). An endmember analysis using hydro-chemical data suggested that about 20% of the DPC mass in a pumping well originated from the neighboring catchment and on its own would cause a concentration above 0.1 μg L−1 for DPC. Our findings highlight that the mobile metabolites can be imported from zones with intense agriculture outside of the exploited aquifer via surface-water groundwater interactions influencing the metabolite concentration level and longterm dynamics in the aquifer. - PublicationAccès libreOut of scale out of place: Black rhino forage preference across the hierarchical organization of the savanna ecosystem(2020-3-6)
; ; - PublicationAccès librePlastoquinone homoeostasis by Arabidopsis proton gradient regulation 6 is essential for photosynthetic efficiency(2019-6-20)
; ; ; ; ; - PublicationAccès libreVariable effects on growth and defense traits for plant ecotypic differentiation and phenotypic plasticity along elevation gradients(2019-2-28)
; ; ; Along ecological gradients, phenotypic differentiation can arise through natural selection on trait diversity and magnitude, and environment‐driven plastic changes. The magnitude of ecotypic differentiation versus phenotypic plasticity can vary depending on the traits under study. Using reciprocal transplant‐common gardens along steep elevation gradients, we evaluated patterns of ecotypic differentiation and phenotypic plasticity of several growth and defense‐related traits for two coexisting but unrelated plant species, Cardamine pratensis and Plantago major. For both species, we observed ecotypic differentiation accompanied by plasticity in growth‐related traits. Plants grew faster and produced more biomass when placed at low elevation. In contrast, we observed fixed ecotypic differentiation for defense and resistance traits. Generally, low‐elevation ecotypes produced higher chemical defenses regardless of the growing elevation. Yet, some plasticity was observed for specific compounds, such as indole glucosinolates. The results of this study may suggest that ecotypic differentiation in defense traits is maintained by costs of chemical defense production, while plasticity in growth traits is regulated by temperature‐driven growth response maximization. - PublicationMétadonnées seulement
- PublicationAccès libreAdsorbing vs. Nonadsorbing tracers for assessing pesticide transport in arable soils(2017-9)
; ; ; - PublicationAccès libreSensitive and selective quantification of free and total malondialdehyde in plasma using UHPLC-HRMS(2017-7-10)
; ; ; ; ; Quantification of malondialdehyde (MDA) as a marker of lipid peroxidation is relevant for many research fields. We describe a new sensitive and selective method to measure free and total plasmatic MDA, using derivatization with 2,4-dinitrophenylhydrazine (DNPH) and ultrahigh performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Free and total MDA were extracted from minute sample amounts (10 μL) using acidic precipitation and alkaline hydrolysis followed by acidic precipitation, respectively. Derivatization was completed within 10 min at room temperature, and the excess DNPH discarded by liquid-liquid extraction. Quantification was achieved by internal standardization using dideuterated MDA as internal standard. The method lowest limit of quantification (LLOQ) was 100 nM and linearity spanned > 3 orders of magnitude. Intra- and inter-day precisions for total MDA were 2.9% and 3.0%, respectively, and those for free MDA were 12.8% and 24.9%, respectively. Accuracy was 101% and 107% at low and high concentrations, respectively. In human plasma, free MDA levels were 120 nM (SD 36.26) and total MDA levels were 6.7 μM (SD 0.46). In addition, we show the applicability of this method to measure MDA plasma levels from a variety of animal species, making it invaluable to scientists in various fields.
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