Seeds of the Arabidopsis thaliana HapMap cohort (360 natural populations) were surface sterilized using 3:10 bleach solution in constant agitation for 10 minutes and rinsed with sterile water six times. Seeds were stratified for 4 days at 4 C in 0.1% agar solution to synchronize germination, then 5 seeds per accession were sown in two soil types with contrasted Pb concentrations into pot trays. The control soil was a mix of commercial potting mix soil with perlite (2:1); the mine soil was a mix of soil from an ancient lead mine (Mina de Can Vergeli; 41°53'42.4"N 3°01'11.7"E), commercial potting mix soil and perlite (2:1:1). Trays were placed in a growth chamber with 150 mmol/m2s of light intensity, 12h light/12h dark photoperiod, and 25 ºC /20 ºC day/night temperature. Trays were bottom-watered twice weekly with deionized water. Germination and survival were monitored and rosette diameter (RD) of 3 individuals per accession and soil type was measured weekly for 4 weeks.