Growth of Arabidopsis Thaliana Under Zinc Stress

Multiple studies of A. thaliana were conducted to determine the plant’s tolerance of ZnCl2 in varying situations of exposure to the ions. In initial accumulation assays (Part 1), A. thaliana seedlings were transferred from normal growth media to concentrations of 0.25 mM – 1.00 mM ZnCl2 treatment media at two weeks after initial plating and grown an additional week on the treated media. Amounts of zinc taken up by the plants were quantified utilizing atomic absorption analysis with inconclusive results. Tolerance assays (Part 2) were conducted in which A. thaliana was grown from seeds on varying concentrations (0.050 mM – 5.0 mM) ZnCl2 treatment media for two weeks. Photographs documented plant growth at 7, 10, 12, and 14 days post-plating and were analyzed to assay root length as a measure of growth attained by the plants, resulting in determination that concentrations from 3.5 mM – 4.0 mM ZnCl2 are detrimental to plant growth, but not completely inhibitory. Concentrations ≥4.5 mM ZnCl2 are completely toxic to A. thaliana. Studies were continued to quantify amounts of Zn accumulated within the plants. In another round of accumulation assays (Part 3), A. thaliana seedlings were transferred to concentrations of 0.25 mM – 2.00 mM ZnCl2; amounts of Zn accumulated by the plants were analyzed via atomic absorption. To determine partitioning of accumulated Zn within A. thaliana (Part 4), a final round of accumulation assays were performed utilizing concentrations of 0.25 mM – 1.00 mM ZnCl2 in which roots were separated from shoots prior to analysis via atomic absorption