Analysis of the impact of zinc and cadmium on Dune Lupine
Mentor:Michelle Lum, Associate Professor of Biology, Loyola Marymount University
Zinc and cadmium are metals used in the industrial process and are considered to be toxic and dangerous environmental pollutants. Phytoremediation is a treatment that involves the use of plants to extract or break down environmental contaminants. This research focuses on the potential of Dune Lupine (Lupinus chamissonis), a woody legume found in the Ballona wetlands and the El Segundo sand dunes, as a phytoremediation agent. In particular, we are interested in zinc and cadmium due to their prevalence in the Ballona Wetlands. The first objective of the study was to determine the heavy metal tolerance of Dune Lupine. Dune Lupine was grown hydroponically in four different treatments for each zinc and cadmium: a control with only the Hoagland nutrient solution; 100 μM heavy metal; 250 μM heavy metal; and 500 μM heavy metal. After five weeks of growth, the plants were collected from the treatments. The plant’s performance was based on shoot dry weight, root dry weight, shoot length and root length. The data was averaged and analyzed statistically. The plants demonstrated a tolerance of zinc up to 250 μM. The initial experiment with cadmium showed that any concentration larger than 100 μM resulted in plant death. A test using lower concentrations of 25 μM, 50 μM, and 100 μM cadmium showed that plants begin to show a significant decline at around 50 μM. In terms of heavy metal tolerance, Dune Lupine was shown to withstand 250 μM of zinc and 50 μM of cadmium without any noticeable signs of decline. Based on these results, the next step in the experiment will be to determine if Dune Lupine’s performance can be enhanced by introducing Plant-Growth Promoting Rhizobacteria to its roots.