Arabidopsis and the Effects of Acid Rain Abstract The aim of this project is to further the understanding of RNA interference by observing the effects of a certain environmental stress, in this case low pH in the water to imitate acid rain, on genetically altered “mutants” of the plant Arabidopsis Thaliana. The genes being studied are DCL-4 and RDR-6. The effects of this environmental stress will be measured by observing changes in phenotypic traits of the mutants compared to the wild type Arabidopsis that is undergoing the same treatment. Along with the treatment we will have controls for wild type, DCL-4, and RDR-6 which will be watered with regular tap water. Results In this experiment we mixed 3.5 liters of water with 20 drops of sulfuric acid to get a pH of 4.0. This pH is about the same as acid rain. We then put this stress onto the gene manipulated plants of DCL-4, RDR-6, and wild type. For the DCL-4 mutant the treatment plants grew bigger than the controls. For the wild type and RDR-6 all of the plants were intermixed with leaf length. Even though the treatment plants and control plants grew the same or bigger the treatment plants were weaker than the control plants. The treatment plants even started to become a yellowish color. We feel that with more time and more data collection, more growth would be seen from the control than the treatment specimens. Picture from http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/A/arabidopsis.jpg Picture from http://nobelprize.org/nobel_prizes/medicine/laureates/2006/illpres/images/4.jpg Conclusions From our results we can see that the plants were a lot weaker under the effects of acid rain. With more time the control plants would have grown bigger than the treatment ones. Turning off the genes of DCL-4 and RDR-6 didn’t seem to affect the way the plants responded to the environmental stress. Because Arabidopsis Thaliana acts like a crop you can expect other crops to respond in a similar way. Acknowledgments Dr. Lisa K. Johansen of the University Of Colorado-Denver Post Net