DIFFERENCE IN THE TRANSLOCATION RATE OF EFFECTOR PROTEINS INTO MUTANT AND WILD-TYPE ARABIDOPSIS LINES
Elizabeth Alger1, Mieder Palm-Forster2, Brad Day2.
1Division of Science & Environmental Policy, California State University, Monterey Bay, Seaside, CA, 2Michigan State University, East Lansing, MI.
In order to cause disease in plants, many bacterial plant pathogens use the type III secretion system (T3SS) to inject plants with virulence proteins, termed type-III effectors (T3Es). By developing a deeper understanding of this plant-microbe disease interaction, we can develop plants that can better withstand biotic stressors. This study focused on the interaction between Pseudomonas syringae pv. tomato strain DC3000, and Arabidopsis thaliana. Specifically, we investigated whether there is a significant difference between the translocation of the virulence protein AvrRpt2 into wild-type and mutant Arabidopsis lines. To do so, we are currently working to optimize the calmodulin-dependent adenylate cyclase (Cya) reporter system by collecting Arabidopsis samples at various time points. Based on previous results, we hypothesize that Arabidopsis mutants lacking or with a nonfunctional NDR1 gene, which is required for the activation of disease resistance to AvrRpt2 in Arabidopsis, will have lower rates of AvrRpt2 translocation than the wildtype. The Cya system will allow for better detection of effector protein transduction, which will, in turn, provide new insights into T3SSs. Results have shown no consistent relationship between translocation rates and the mutant and wild-type Arabidopsis lines. We predict this is due to changing factors that may stress the plant and affect translocation rates such as temperature or humidity. Future experiments will be conducted to determine the factors that affect translocation rates of AvrRpt2.