Abstract
In the decades to come, atmospheric CO2 concentration is expected to steadily increase. This comes as a serious threat to food security, as the ionome of C3 plants declines when exposed to high CO2 conditions [2]. Even though several physiological hypotheses have been put forward, the reasons behind this mineral depletion are still largely unclear. Recent studies examined several genetically diverse lines of cultivated rice and concluded that genetic diversity could be a source of variability in iron, zinc, and protein changes under elevated CO2[3]. To identify polymorphisms underlying such intra-specific diversity could not only be a way to understand this response, but also to breed more resilient crops. In this work, we screened three populations of Arabidopsis thaliana ecotypes, originating from local, regional and world-wide geographic scales, and characterized the phenotypic variability observed in their ionome response to high CO2. We could confirm a global decline of mineral status happening jointly with an increase in carbon content, and identify a subset of more tolerant lines with a preserved nutrient content. We further performed GWAs on mineral elements under elevated CO2 for the REGMAP accessions [1], based on linear mixed models. Our analysis brought out haplotypes of interest, and candidate genes for the control of iron and nitrogen accumulation in Arabidopsis leaves under elevated CO2.