Elevated CO2 negatively impacts the ionome content at the population-scale level in Arabidopsis thaliana.

A. Representation of the experimental design used in this study. The content of eight mineral elements was assessed for around 600 Arabidopsis thaliana accessions coming from the REGMAP (B), LANGUEDOC (C) and TOU-A (D) populations. Each dot represents the value of the content of a mineral element for one accession (yellow: ambient CO2 (aCO2, ∼420 ppm), blue: elevated CO2 (eCO2, 900 ppm). N (% of dry weight), Fe (µg.g-1 dry weight), Zn (µg.g-1 dry weight), Cu (µg.g-1 dry weight), Mg (µg.g-1 dry weight), Mn (µg.g-1 dry weight), Na (µg.g-1 dry weight), C (% of dry weight). Asterisks indicate significant differences (Paired Wilcoxson test; *, P < 0.05; **, P < 0.005; ***, P < 0.0005). ns; not significant.

Elevated CO2 leads to high phenotypic diversity of ionome response in Arabidopsis thaliana.

Distributions of the relative change (%) of the content of 8 mineral elements between elevated CO2 and ambient CO2, in each population (A: REGMAP, B: LANGUEDOC, C: TOU-A). Each dot represents the value of the relative change of the content a mineral element for one accession. The name of the element appears in bold if the mean of the element in elevated CO2 is significantly different from the mean of the element in ambient CO2 (Paired wilcoxon test, significance threshold of 0.05).

Elevated CO2 results in a general pattern of ionome variation common to most accessions constituting natural populations of Arabidopsis thaliana.

Principal Component Analysis (PCA) was performed using the variation of each element in response to elevated CO2. A. Natural accessions were positioned on the PCA and colored based on population. B. Contribution of each element to the PCA axis.

Variation in the response of the ionome to elevated CO2 identifies contrasting subpopulations inside the REGMAP panel.

K-means clustering was performed in the REGMAP accessions to identify different subpopulations. Each accession is represented by a dot, connected by a line between each element. Cluster 1:65 accessions. Cluster 2: 25 accessions. Cluster 3: 69 accessions.

Genetic architecture of the response of the ionome to elevated CO2 in the REGMAP panel of Arabidopsis thaliana.

A. Manhadan plots for the content of eight mineral elements under elevated CO2, or for the relative change of the content of mineral elements between elevated CO2 and ambient CO2. For each Manhadan plot, SNPs with the 50 most significant P-value, located above the horizontal line, are colored. Bar plots showing the number of SNPs identified by GWAs for traits under elevated CO2 (B) or for the relative change of the content of mineral elements between elevated CO2 and ambient CO2 (C) that are unique to one element or shared between 2 or 3 traits.

Identification of genes detected by GWA mapping and differentially regulated by elevated CO2.

Intersection between elevated CO2-DEG in shoot (A) or root (B) and genes identified by GWA mapping. UpSet plots display the number of elevated CO2-DEG that are associated to a locus identified for the content or the relative change of one or several mineral elements under elevated CO2. Illustration of the padern of elevated CO2-DEG in shoot (C) or root (D) also identified by GWA mapping.

Natural variation of the TIP2;2 gene is associated with improved responses of Zn content to elevated CO2.

A. Manhattan plot of the relative change of Zn content between elevated CO2 and ambient CO2 showing the presence of a peak closed to the TIP2;2 locus. B. Comparison of haplotypes and their relative change of Zn content between elevated CO2 and ambient CO2. Three SNPs located at the TIP2;2 locus are associated to an improvement of Zn content under elevated CO2 for accessions that possess them (haplotype 1) compared to the rest of the population (haplotype 0). C, D. Relative expression of TIP2;2 in the roots under ambient (C) or elevated (D) CO2 for accessions belonging to haplotype 0 or haplotype 1. Relative expression levels were calculated based on UBQ10 as internal control. Horizontal black line represented the median of each group of haplotypes. ***P < 0,001, **P < 0,01, unpaired Mann-Whitney test. E. Shoot Zn content under ambient or elevated CO2 for WT (Columbia) and tip2;2-1 mutant. Data are presented as the mean (with SD) of 5 and 6 biological repeats for the WT and tip2;2-1, respectively.**P < 0.01, unpaired Mann-Whitney test.