Genome-Wide Association Studies Identify Heavy Metal ATPase3 as the Primary Determinant of Natural Variation in Leaf Cadmium in Arabidopsis thaliana
A. DNA microarray-based bulk segregant analysis of the low leaf Cd phenotype of CS28181 using phenotyped F2 progeny from a CS28181×Col-0 cross genotyped using the 256K AtSNPtilling microarray. Lines represent allele frequency differences between high and low leaf Cd pools of F2 plants at SNPs known to be polymorphic between CS28181 and Col-0 (black line = sense strand probes, blue line = antisense strand probes). B. Fine mapping localizes the causal gene to a 500 kb interval between markers Fo14.5M and Fo15 indicated by the red vertical lines. Black bars represent the CS28181 genotype, grey bars represent heterozygous genotypes and white bars represent Col-0 genotype. Recombinants were selected from 317 CS28181×Col-0 F2 plants. Leaf Cd concentration was determined in the F2 and/or the F3 generation. C. Localization and gene structure of HMA2 and HMA3 in the mapping interval. Black bars indicate exons and black lines indicate introns.