The Uptake of Copper by Plants of Mimulus Guttatus Differing in Genotype Primarily at a Single Major Copper Tolerance Locus

SUMMARY The pattern of uptake of copper by plants of Mimulus guttatus that are either homozygous tolerant, homozygous non‐tolerant, or heterozygous tolerant, was compared. Tolerant plants took up more copper, particularly into the roots, and root uptake by the homozygote tolerant was greater than the heterozygote. Plants of all three genotypes took up increasing quantities of copper to their roots until day 7, but no further increase was obtained by day 11. The physiological implication of these results is discussed.