15 research outputs found

    Restauration de la flore des prés salés continentaux : expérimentation sur le marais de Saint-Beauzire (Puy-de-DÎme, 63)

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    This article presents a case study of recolonization by flora constituting a continental salt meadow type vegetation after the removal of an embankment on a continental salt marsh in the Limagne plain (Puy-de-DĂŽme, France). Salt marshes indicator plants was monitored in presence/absence in a network of 104 meshes of 10 mÂČ. We were able to show the rapid and lasting colonization of Puccinellia distans and Juncus gerardi, but also the slower and variable installation of Spergula media and Plantago maritima. We mapped spatial and temporal evolutions of this colonization for 6 different species. Among the halotolerant species, one should note the increase in the population of endangered species such as Inula britannica. The monitoring protocol allows us to conclude on the interest of this type of embankment removal operation to restore the abiotic parameters and the flora of the «continental salt meadow» vegetation.Cet article prĂ©sente une Ă©tude de cas de recolonisation par la vĂ©gĂ©tation de type prĂ© salĂ© continental aprĂšs des travaux de suppression d’un remblai sur un marais salĂ© continental dans la plaine de la Limagne (Puy-de-DĂŽme, France). Les plantes indicatrices des prĂ©s salĂ©s ont Ă©tĂ© suivies en prĂ©sence/absence dans un rĂ©seau de 104 mailles de 10 mÂČ. Nous avons pu montrer la colonisation rapide et durable de Puccinellia distans et Juncus gerardi, mais aussi l’installation plus lente et variable de Spergula media et de Plantago maritima. Nous avons cartographiĂ© les Ă©volutions spatiales et temporelles de cette colonisation pour 6 espĂšces diffĂ©rentes. Parmi les espĂšces halotolĂ©rantes, on notera l’augmentation de la population d’espĂšces menacĂ©es comme celle d’Inula britannica. Les rĂ©sultats permettent de conclure sur l’intĂ©rĂȘt de ce type d’opĂ©ration de suppression de remblais pour restaurer les paramĂštres abiotiques et de la capacitĂ© de la flore de se rĂ©installer mĂȘme aprĂšs vingt-cinq ans pour reconstituer une communautĂ© vĂ©gĂ©tale caractĂ©ristique des « prĂ©s salĂ©s continentaux »

    Restauration de la flore des prés salés continentaux : expérimentation sur le marais de Saint-Beauzire (Puy-de-DÎme, 63)

    Get PDF
    International audienceThis article presents a case study of recolonization by flora constituting a continental salt meadow type vegetation after the removal of an embankment on a continental salt marsh in the Limagne plain (Puy-de-DĂŽme, France). Salt marshes indicator plants was monitored in presence/absence in a network of 104 meshes of 10 mÂČ. We were able to show the rapid and lasting colonization of Puc-cinellia distans and Juncus gerardi, but also the slower and variable installation of Spergula media and Plantago maritima. We mapped spatial and temporal evolutions of this colonization for 6 different species. Among the halotolerant species, one should note the increase in the population of endan-gered species such as Inula britannica. The monitoring protocol allows us to conclude on the interest of this type of embankment removal operation to restore the abiotic parameters and the flora of the «continental salt meadow» vegetation.Cet article prĂ©sente une Ă©tude de cas de recolonisation par la vĂ©gĂ©tation de type prĂ© salĂ© continental aprĂšs des travaux de suppression d’un remblai sur un marais salĂ© continental dans la plaine de la Limagne (Puy-de-DĂŽme, France). Les plantes indicatrices des prĂ©s salĂ©s ont Ă©tĂ© suivies en prĂ©sence/absence dans un rĂ©seau de 104 mailles de 10 mÂČ. Nous avons pu montrer la colonisation rapide et durable de Puccinellia distans et Juncus gerardi, mais aussi l’installation plus lente et variable de Spergula media et de Plantago maritima. Nous avons cartographiĂ© les Ă©volutions spatiales et temporelles de cette colonisation pour 6 espĂšces diffĂ©rentes. Parmi les espĂšces halotolĂ©rantes, on notera l’augmentation de la population d’espĂšces menacĂ©es comme celle d’Inula britannica. Les rĂ©sultats permettent de conclure sur l’intĂ©rĂȘt de ce type d’opĂ©ration de suppression de remblais pour restaurer les paramĂštres abiotiques et de la capacitĂ© de la flore de se rĂ©installer mĂȘme aprĂšs vingt-cinq ans pour reconstituer une communautĂ© vĂ©gĂ©tale caractĂ©ristique des « prĂ©s salĂ©s continentaux »

    Transcription factor FOXL2 protects granulosa cells from stress and delays cell cycle: role of its regulation by the SIRT1 deacetylase.

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    International audienceFOXL2 is a transcription factor essential for ovarian function and maintenance, whose germline mutations are responsible for the Blepharophimosis syndrome (BPES), often associated with premature ovarian failure/ageing. Recent evidence has linked FOXL2 downregulation or somatic mutation (p.Cys134Trp) to cancer, though underlying molecular mechanisms remain unclear. Using a functional genomics approach, we find that FOXL2 modulates cell cycle regulators in a way which should lead to G1 arrest. Indeed, FOXL2 upregulation promotes cell accumulation in the G1 phase and protects cells from oxidative damage, notably by promoting oxidized DNA repair and by increasing the amounts of anti-oxidant agent Glutathione. In agreement with clinical observations, we find that FOXL2 mutated versions leading to BPES along with ovarian dysfunction mostly fail to transactivate cell-cycle and DNA repair targets, whereas mutations leading to isolated craniofacial defects (and normal ovarian function) activate them correctly. Interestingly, these assays revealed a mild promoter-specific hypomorphy of the tumor-associated mutation (p.Cys134Trp). Finally, the SIRT1 deacetylase suppresses FOXL2 activity on targets linked to cell cycle and DNA-repair in a dose-dependent manner. Accordingly, we find that SIRT1 inhibition by nicotinamide limits proliferation, notably by increasing endogenous FOXL2 amount/activity. The body of evidence presented here supports the idea that FOXL2 plays a key role in granulosa cell homeostasis, the failure of which is central to ovarian ageing and tumorigenesis. Since granulosa cell tumors respond poorly to conventional chemotherapy, our findings on the deacetylase inhibitor nicotinamide provide an interesting option for targeted therapy
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