The goal of this research study is to gain an understanding of the mechanism of antibiotic resistance in plants. Previous investigations revealed a link between metal uptake and antibiotic resistance, such as, a decrease in iron uptake in plants exposed to kanamycin. We hypothesize this relationship depends on the presence of citrate in the media. To test our hypothesis in our experiments Control and WBC19 mutant seedlings known to be highly sensitive to kanamycin were used. Citrate was added to all MS media which otherwise contained normal amounts of iron and zinc. Media differed by either the presence or absence of kanamycin. Seedlings were grown for 7 days, 10 days, and 13 days, followed by the collection of plant material for metal analysis. Under our experimental conditions i.e. citrate added to the MS media, we observed a decrease of iron uptake in the control plants. As anticipated, the WBC19 mutants were more sensitive to kanamycin and the overall metal uptake fell considerably. In conclusion our results support our hypothesis that when citrate is present in the media, metal uptake is highly disrupted. Based on these findings, we have developed a model for metal uptake that takes citrate into account.
