Sasan Salimian, Biochemistry and Molecular Biology
"Characterization of SUP8, a suppressor of the constitutive defense mutuan
acd6-1 in Arabidopsis thaliand"
Faculty Mentor: Dr. Hua Lu
Expected Graduation Date: Spring 2009
The goal of my research is to characterize the role of SUP8, a histone H2A gene, in defense regulation in Arabidopsis thaliana. Plant diseases are very deterrent to agriculture worldwide. Identification and characterization of novel defense genes will help us to design better strategies to enhance plant disease resistance. The sup8 mutant was isolated from a large-scale mutant screen aimed at identifying novel defense related genes in Arabidopsis. This screen was based on the unique defense-dependent size change in a mutant called “accelerated cell death 6-1” (acd6-1). acd6-1 is a tiny plant with constitutive defense. Suppressors of acd6-1 are larger plants associated with reduced defense. A mutation in SUP8 suppressed acd6-1 dwarfism, suggesting a role of SUP8 in defense regulation. To confirm this, I will complement the acd6-1sup8-1 plants with a correct SUP8 to see if this causes a rescue phenotype, returning larger-sized acd6-1sup8-1 plants to smaller sup6-1-like plants. I will also infect acd6-1 plants with SUP8 amiRNA to check for compromised defense. If so, I will further characterize how SUP8 regulates defense responses by infecting acd6-1sup8-1 and acd6-1 plants with Pseudomonas syringae and examining bacterial growth and disease symptom development in the mutants. This work will elucidate if SUP8, a gene involved in chromosome remodeling, also plays a role in plant defense.