Project description:Microbial communities of boreal peatlands under climate change conditions: Does community structure indicate the dynamics of ecosystem function?
Project description:Microbial communities of boreal peatlands under climate change conditions:Does community structure indicate the dynamics of ecosystem function?
Project description:Diazotrophs provide the main source of reactive nitrogen to the ocean, sustaining primary productivity and CO2 uptake. Climate change is raising temperatures, decreasing pH and reducing nutrient availability. How microbes respond to these changes is largely unexplained. Similarly, the role of DOM in the growth and survival of certain diazotrophic organisms is poorly understood. Moreover, growing evidence indicates some diazotrophs are capable of utilizing distinct DOM compounds via osmotrophy providing them with additional metabolic plasticity and ecological advantages compared to other non-diazotrophic microbes. We aimed to understand how osmotrophy could modify carbon uptake and alleviate energy stress in diazotrophs under ongoing climate change perturbations. We hypothesized that Crocosphaera preferentially uses DOM when labile as a carbon source in present pH conditions, as compared to future more acidic scenarios with higher access to inorganic carbon. Alternatively, the lower pH may cause Crocosphaera to be energy limited when trying to maintain intracellular homeostasis which would favour DOM uptake as an extra source of energy.
Project description:Grapevines cv Sauvignon Blanc were subjected to different stress regimes by simulating the most common extreme weather events occurring within the current climate change scenario. During spring, just before bud break, the vines were either flooded or kept under normal conditions. Both vines were then split in two groups and put in differnt tunnels, either undergoing a simulated heatwave or not. Berry samples were collected from the four groups of plants (control, only flooded, only heatwave, flooded + heatwave) at different timepoints before, during and after the stress. Transcriptomic analyses were carried out on these samples along with some metabolomic assessments to characterize the response to stress in the different samples and the effect of the combined stresses.
