Date of Award


Degree Name

Master of Science


Biological Sciences

First Advisor

Dr. Jian Yao

Second Advisor

Dr. Yan Lu

Third Advisor

Dr. Todd Barkman

Access Setting

Masters Thesis-Campus Only

Restricted to Campus until



The jasmonic (JA) and salicylic acid (SA) signaling systems regulate diverse plant developmental processes and immune responses. Due to the opposite end-goals of various pathogen-response pathways, a certain level of antagonism between the JA and SA pathways is required. However, over-suppression of any single pathway would leave a plant susceptible to invasion by a specific class of pathogen. We investigate the regulation of crosstalk between the JA- and SA-mediated immune pathways and how the dilemma of specific susceptibility may be avoided. Manipulation of Arabidopsis thaliana genotypes was utilized to determine the effects of protein knockout on pathogen-specific susceptibility and resistance. The effects of hormone treatment on protein concentration and the effects of protein knockout on the plant transcriptome were investigated as well. Loss of the plant U-box protein 25/26 increased susceptibility of plants to necrotrophic pathogen Pectobacterium carotovorum, indicating that this protein is instrumental in regulation of immune pathways required for optimization of fitness.