1. Myxobacteria as a Means of Controlling Agricultural Plant Pathogens. Cameron Finley & Daniel Wall Molecular Biology Department PROPOSED RESEARCH PROJECT Based upon previous work showing that myxobacteria are effective killers of microbial pathogens 1, it is hypothesized that myxobacteria will control microbial pathogens of corn, barley, and sugar beets in soil and within the exposed plant themselves. Myxobacteria are soil microbes that display swarming motility and predate on other microbes utilizing antibiotics to and hydrolytic enzymes to neutralize, kill and digest their prey. It has been previously shown that myxobacteria are effective killers of several pathogenic fungi of strawberries (1). However, further work into use of myxobacteria to control plant pathogens of other crops (such as corn, barley, and sugar beets) has not been conducted. Additionally, no work has been done to show that myxobacteria can actively control pathogens within soil or when the pathogens are exposed to their plant hosts. I thank University of Wyoming McNair Scholars Program and Zackie Salmon, Susan Stoddard, and Pilar Flores for their support. I thank Dr. Daniel Wall, Arup Dey, and Darshankumar Pathak of the UW Molecular Biology Department for their support. Statement of the Problem This research will examine whether or not the predatory myxobacteria can be exploited to managed various pathogens of agricultural crops such as barley, corn, and sugar beets. Introduction Hypothesis Methods Microbial kill assays against pathogens will be conducted using various laboratory strains of myxobacteria as well as environmental isolates on agar plates. Agricultural soils will be collected and autoclaved to eliminate interaction of uncontrolled microbes. The sterilized soil samples will be used to conduct further kill assays to more closely mimic the natural environment. Finally, corn, barley, and sugar beets will be grown in a controlled environment and exposed to their respective pathogens. Subsequently, myxobacteria will be introduced to the infected plants in order to determine whether crop disease can be prevented. Data Analysis The myxobacteria candidates of the initial kill assay will compared for killing potential by 2-sample-t- test. The best predators will then be tested in a secondary soil screening against a control in which no myxobacteria are introduced using a 2-sample-t-test to determine whether there is a significant difference over the control. Lastly, the results of the final plant test will be modeled using simple linear regression to show whether there is a true correlation between the presence of myxobacteria and the severity of pathogenic infection. Figure 1: Inhibition of fungus P. capsici by by different myxobacteria modeled as percent fungal growth as compared to the control (1). Importance of the Study Plant pathogens cause substantial economic damages. It has been estimated that $33 billion of productively are lost due to agricultural plant pathogens in the US alone (3). If myxobacteria can be shown to effectively treat infected agricultural crops, it may have important agricultural consequences. References 1. C.T. Bull, K.G. Shetty, and K.V. Subbarao. August 2002. Interactions Between Myxobacteria, Plant Pathogenic Fungi, and Biocontrol Agents. Plant Disease. Volume 86 No. 889-896. 2. Soltis, Greg. 2/03/2009. Cluster’s Last Stand. POPSCI. http://www.popsci.com/node/31695 http://www.popsci.com/node/31695 3. Pimentel, David. Biological Invasions: Economic and Environmental Costs of Alien Plant, Animal, and Microbe Species. CRC Press. 2002. Acknowledgements