Natural genetic variation underlying the negative effect of elevated CO₂ on ionome composition in Arabidopsis...

The elevation of atmospheric CO₂ leads to a decline in plant mineral content, which might pose a significant threat to food security in coming decades. Although few genes have been identified for the negative effect of elevated CO₂ on plant mineral composition, several studies suggest the existence of genetic factors. Here, we performed a large-scale study to explore genetic diversity of plant ionome responses to elevated CO₂, using six hundred Arabidopsis thaliana accessions, representing geographical distributions ranging from worldwide to regional and local environments. We show that growth under elevated CO₂ leads to a global decrease of ionome content, whatever the geographic distribution of the population. We observed a high range of genetic diversity, ranging from the most negative effect to resilience or even to a benefit in response to elevated CO₂. Using genome-wide association mapping, we identified a large set of genes associated with this response, and we demonstrated that the function of one of these genes is involved in the negative effect of elevated CO₂ on plant mineral composition. This resource will contribute to understand the mechanisms underlying the effect of elevated CO₂ on plant mineral nutrition, and could help towards the development of crops adapted to a high-CO₂ world.