ProMeSD · Prokaryotic DNA Methylation under Soil Drought

Intensifying droughts, driven by climate change, threaten European soils—critical carbon sinks regulated by microbial communities. The mechanisms governing microbial drought responses remain a major knowledge gap, limiting our ability to predict ecosystem-climate feedbacks. ProMeSD will pioneer environmental meta-epigenomics in soils to test the central hypothesis that past precipitation history creates a ""molecular memory"" via DNA methylation. Specifically, it predicts that microbes in historically drier soils maintain promoter hypomethylation of stress-response genes, predisposing them for rapid transcriptional activation during new drought events. This novel approach moves beyond simple gene inventories to uncover a missing regulatory layer connecting genetic potential to ecosystem function. In a controlled mesocosm experiment using soils from a natural Italian precipitation gradient (500–3,000 mm), ProMeSD will integrate cutting-edge hybrid sequencing (PacBio/Illumina), metatranscriptomics, and biogeochemical assays. The project will (1) build the first metagenome-resolved atlas of soil DNA methylation, (2) link methylation states to stress-gene expression, and (3) connect these molecular patterns to ecosystem functions like carbon use efficiency. This MSCA fellowship unites leading expertise in soil ecology (University of Bologna) and meta-epigenomics (Kunsan National University), ensuring project success. By generating FAIR datasets and transferable workflows, ProMeSD will deliver novel soil health indicators supporting the EU Green Deal and Mission ""A Soil Deal for Europe."" The project's findings have the potential to generate trait-based markers of resilience for integration into microbial-explicit climate models (e.g., MEND, MIMICS), ultimately improving forecasts of soil carbon turnover under future drought scenarios.""