Plant material
In previous studies, natural variation of Arabidopsis thalianapopulations from Catalonia [20] were tested in a multi-year small scale common garden under carbonated and non-carbonated soils [5]. Seeds of 6 extreme phenotype plants from A1(c+), a soil carbonate tolerant deme, and 6 extreme phenotype plants from T6(c-), a soil carbonate sensitive deme, were collected from the last reciprocal transplant experiment performed in 2015 and stored under fresh (4ยบ C) and dry conditions until the beginning of hydroponic and soil cultivation experiments. A1xT6 and T6xA1 crosses were generated using the 6 A1(c+) and 6 T6(c-) lines (generating 12 crossing lines) and self-crossed for three generations (F1, F2, F3). Col-0 seeds and seeds of 18 T-DNA mutants with Col-0 background were purchased from NASC/ABRC [21]. Segregating lines were genotyped using specific primers and multiplied for T2 generations. The non-expression of the genes was validated through qPCR (Dataset_SD1).